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  • 1.
    AbdelMageed, Manar
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry. Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt.
    Ali, Haytham
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry. Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt.
    Ohlsson, Lina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lindmark, Gudrun
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Sitohy, Basel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    The Chemokine CXCL16 Is a New Biomarker for Lymph Node Analysis of Colon Cancer Outcome2019In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 20, no 22, article id 5793Article in journal (Refereed)
    Abstract [en]

    hemokines are important in the development and progression of tumors. We investigated the expression of CXCL14 and CXCL16 in colon cancer. Expression of mRNA was assessed in primary tumors and lymph nodes and CXCL16 mRNA levels were correlated to patient’s survival. Protein expression was investigated by two-color immunofluorescence and immunomorphometry. CXCL14 and CXCL16 mRNA levels and protein expression were significantly higher in colon cancer primary tumors compared to apparently normal colon tissue. Positive cells were tumor cells, as revealed by anti-CEA and anti-EpCAM staining. CXCL16, but not CXCL14, mRNA levels were significantly higher in hematoxylin and eosin positive (H&E(+)) compared to H&E(−) colon cancer lymph nodes or control nodes (P < 0.0001). CXCL16 mRNA was expressed in 5/5 colon cancer cell lines while CXCL14 was expressed significantly in only one. Kaplan-Meier analysis revealed that colon cancer patients with lymph nodes expressing high or very high levels (7.2 and 11.4 copies/18S rRNA unit, respectively) of CXCL16 mRNA had a decreased mean survival time of 30 and 46 months at the 12-year follow-up (P = 0.04, P = 0.005, respectively). In conclusion, high expression of CXCL16 mRNA in regional lymph nodes of colon cancer patients is a sign of a poor prognosis.

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  • 2.
    AbdelMageed, Manar
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
    Ismail, Hager
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
    Ohlsson, Lina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Lindmark, Gudrun
    Institution of Clinical Sciences, Lund University, Helsingborg, Sweden.
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Hammarström, Sten
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Immunology/Immunchemistry.
    Sitohy, Basel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology. Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Clinical significance of stem cell biomarkers epcam, lgr5 and lgr4 mrna levels in lymph nodes of colon cancer patients2022In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 23, no 1, article id 403Article in journal (Refereed)
    Abstract [en]

    The significance of cancer stem cells (CSCs) in initiation and progression of colon cancer (CC) has been established. In this study, we investigated the utility of measuring mRNA expression levels of CSC markers EpCAM, LGR5 and LGR4 for predicting survival outcome in surgically treated CC patients. Expression levels were determined in 5 CC cell lines, 66 primary CC tumors and 382 regional lymph nodes of 121 CC patients. Prognostic relevance was determined using Kaplan‐Meier survival and Cox regression analyses. CC patients with lymph nodes expressing high levels of EpCAM, LGR5 or LGR4 (higher than a clinical cutoff of 0.07, 0.06 and 2.558 mRNA cop-ies/18S rRNA unit, respectively) had a decreased mean survival time of 32 months for EpCAM and 42 months for both LGR5 and LGR4 at a 12‐year follow‐up (p = 0.022, p = 0.005 and p = 0.011, respec-tively). Additional patients at risk for recurrence were detected when LGR5 was combined with the biomarkers CXCL17 or CEA plus CXCL16. In conclusion, the study underscores LGR5 as a particularly useful prognostic biomarker and illustrates the strength of combining biomarkers detecting different subpopulations of cancer cells and/or cells in the tumor microenvironment for predicting recurrence.

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  • 3.
    Abdelrahim, Nada A.
    et al.
    Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, Nile University, Khartoum, Sudan.
    Mohamed, Nahla
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Section of Virology.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Section of Virology.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Fadl-Elmula, Imad M.
    Department of Pathology and Clinical Genetics, Faculty of Medicine, Al-Neelain University, Khartoum, Sudan; Assafa Academy, Kartoum, Sudan.
    Human herpes virus type-6 is associated with central nervous system infections in children in Sudan2022In: African Journal of Laboratory Medicine, ISSN 2225-2002, E-ISSN 2225-2010, Vol. 11, no 1, article id a1718Article in journal (Refereed)
    Abstract [en]

    Background: Human herpes virus type-6 (HHV-6) is increasingly recognised as a febrile agent in children. However, less is known in sub-Saharan African countries, including Sudan.

    Objective: We investigated the involvement of HHV-6 in paediatric central nervous system (CNS) infections in Khartoum, Sudan.

    Methods: Febrile patients aged up to 15 years with suspected CNS infections at Omdurman Hospital for Children from 01 December 2009 to 01 August 2010 were included. Viral DNA was extracted from leftover cerebrospinal fluid (CSF) specimens and quantitatively amplified by real-time polymerase chain reaction (PCR) at Umeå University in Sweden.

    Results: Of 503 CSF specimens, 13 (2.6%) were positive for HHV-6 (33.0% [13/40 of cases with proven infectious meningitis]). The median thermal cycle threshold for all HHV-6-positive specimens was 38 (range: 31.9-40.8). The median number of virus copies was 281.3/PCR run (1 × 105 copies/mL CSF; range: 30-44 × 103 copies/PCR run [12 × 103 - 18 × 106 copies/mL CSF]). All positive patients presented with fever and vomiting; 86.0% had seizures. The male-to-female ratio was 1:1; 50.0% were toddlers, 42.0% infants and 8.0% teenagers. Most (83.0%) were admitted in the dry season and 17.0% in the rainy season. Cerebrospinal fluid leukocytosis was seen in 33.0%, CSF glucose levels were normal in 86.0% and low in 14.0%, and CSF protein levels were low in 14.0% and high in 43.0%.

    Conclusion: Among children in Sudan with CNS infections, HHV-6 is common. Studies on the existence and spread of HHV-6 chromosomal integration in this population are needed.

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  • 4.
    Abdelrahim, Nada Abdelghani
    et al.
    Department of Pathology-Medical Microbiology, Faculty of Medicine, University of Medical Sciences and Technology, Khartoum, Sudan.
    Mohamed, Nahla
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Fadl-Elmula, Imad Mohammed
    Department of Pathology & Clinical Genetics, Al-Neelain University & Assafa Academy, Khartoum, Sudan.
    Viral meningitis in Sudanese children: differentiation, etiology and review of literature2022In: Medicine, ISSN 0025-7974, E-ISSN 1536-5964, Vol. 101, no 46, article id e31588Article, review/survey (Refereed)
    Abstract [en]

    Diagnosis of viral meningitis (VM) is uncommon practice in Sudan and there is no local viral etiological map. We therefore intended to differentiate VM using standardized clinical codes and determine the involvement of herpes simplex virus types-1 and 2 (HSV-1/2), varicella zoster virus, non-polio human enteroviruses (HEVs), and human parechoviruses in meningeal infections in children in Sudan. This is a cross-sectional hospital-based study. Viral meningitis was differentiated in 503 suspected febrile attendee of Omdurman Hospital for Children following the criteria listed in the Clinical Case Definition for Aseptic/Viral Meningitis. Patients were children age 0 to 15 years. Viral nucleic acids (DNA/RNA) were extracted from cerebrospinal fluid (CSF) specimens using QIAamp® UltraSens Virus Technology. Complementary DNA was prepared from viral RNA using GoScriptTM Reverse Transcription System. Viral nucleic acids were amplified and detected using quantitative TaqMan® Real-Time and conventional polymerase chain reactions (PCRs). Hospital diagnosis of VM was assigned to 0%, when clinical codes were applied; we considered 3.2% as having VM among the total study population and as 40% among those with proven infectious meningitis. Two (0.4%) out of total 503 CSF specimens were positive for HSV-1; Ct values were 37.05 and 39.10 and virus copies were 652/PCR run (261 × 103/mL CSF) and 123/PCR run (49.3 × 103/mL CSF), respectively. Other 2 (0.4%) CSF specimens were positive for non-polio HEVs; Ct values were 37.70 and 38.30, and the approximate virus copies were 5E2/PCR run (~2E5/mL CSF) and 2E2/PCR run (~8E4/mL CSF), respectively. No genetic materials were detected for HSV-2, varicella zoster virus, and human parechoviruses. The diagnosis of VM was never assigned by the hospital despite fulfilling the clinical case definition. Virus detection rate was 10% among cases with proven infectious meningitis. Detected viruses were HSV-1 and non-polio HEVs. Positive virus PCRs in CSFs with normal cellular counts were seen.

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  • 5.
    Abdel-Shafi, Seham
    et al.
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    El-Nemr, Mona
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    Enan, Gamal
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    Osman, Ali
    Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt.
    Sitohy, Basel
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Sitohy, Mahmoud
    Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt.
    Isolation and characterization of antibacterial conglutinins from Lupine seeds2023In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 28, no 1, article id 35Article in journal (Refereed)
    Abstract [en]

    The main target of this work is to discover new protein fractions from natural resources with high antibacterial action. The 7S and 11S globulin fractions, as well as the basic subunit (BS), were isolated from lupine seeds (Lupinus termis), chemically characterized, and screened for antibacterial activity against seven pathogenic bacteria. SDS-PAGE revealed molecular weights ranging from 55 to 75 kDa for 7S globulin, 20–37 kD for 11S globulin, and 20 kD for the BS. 11S globulin and the BS migrated faster on Urea-PAGE toward the cathode compared to 7S globulin. FTIR and NMR showed different spectral patterns between the 7S and 11S globulins but similar ones between 11S globulin and the BS. The MICs of the BS were in the range of 0.05–2 μg/mL against Listeria monocytogenes, Klebsiella oxytoca, Proteus mirabilis, Staphylococcus aureus, Listeria ivanovii, Salmonella typhimurium, and Pseudomonas aeruginosa compared to higher values for 11S globulin. The BS surpassed 11S globulin in antibacterial action, while 7S globulin showed no effect. The MICs of 11S globulin and the BS represented only 5% and 2.5% of the specific antibiotic against L. monocytogenes, respectively. Scanning electron microscopy (SEM) demonstrated different signs of cellular deformation and decay in the protein-treated bacteria, probably due to interaction with the bacterial cell wall and membranes. 11S globulin and the BS can be nominated as effective food biopreservatives.

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  • 6.
    Abdel-Shafi, Seham
    et al.
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    El-Serwy, Heba
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    El-Zawahry, Yehia
    Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, Egypt.
    Zaki, Maysaa
    Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
    Sitohy, Basel
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Department of Radiation Sciences, Oncology.
    Sitohy, Mahmoud
    Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt.
    The Association between icaA and icaB Genes, Antibiotic Resistance and Biofilm Formation in Clinical Isolates of Staphylococci spp.2022In: Antibiotics, ISSN 0066-4774, E-ISSN 2079-6382, Vol. 11, no 3, article id 389Article in journal (Refereed)
    Abstract [en]

    Sixty-six (66) Staphylococcus bacterial isolates were withdrawn from separate clinical samples of hospitalized patients with various clinical infections. Conventional bacteriological tests identified the species of all isolates, and standard microbiological techniques differentiated them into CoPS or CoNS. Their biofilm development was followed by an analysis via the MTP (microtiter tissue culture plates) technique, and we then investigated the presence/absence of icaA and icaB, which were qualified in the top-30 potent biofilm-forming isolates. Thirteen isolates (46.7%) showed the presence of one gene, six (20%) isolates exhibited the two genes, while ten (33.3%) had neither of them. The formation of staphylococci biofilms in the absence of ica genes may be related to the presence of other biofilm formation ica-independent mechanisms. CoPS was the most abundant species among the total population. S. aureus was the sole representative of CoPS, while S. epidermidis was the most abundant form of CoNS. Antibiotic resistance was developing against the most frequently used antimicrobial drugs, while vancomycin was the least-resisted drug. The totality of the strong and medium-strength film-forming isolates represented the majority proportion (80%) of the total investigated clinical samples. The biochemical pattern CoPS is associated with antibiotic resistance and biofilm formation and can be an alarming indicator of potential antibiotic resistance.

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  • 7.
    Abdullah, Sara Alawi
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Lång respektive fördröjd provtransport ger försämrad blodprovskvalitet2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 8.
    Abdulleteef, Lina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Förekomst av humant papillomvirus i tonsillcancer i norra regionen i Sverige 2000-20122013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 9.
    Abezie, Henock
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Preanalytisk inverkan av provtagningsrör vid zinkanalys i plasma2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 10.
    Abidine, Yara
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Liu, Lifeng
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Wallén, Oskar
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Trybala, Edward
    Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
    Olofsson, Sigvard
    Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
    Bergström, Tomas
    Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
    Bally, Marta
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Cellular Chondroitin Sulfate and the Mucin-like Domain of Viral Glycoprotein C Promote Diffusion of Herpes Simplex Virus 1 While Heparan Sulfate Restricts Mobility2022In: Viruses, E-ISSN 1999-4915, Vol. 14, no 8, article id 1836Article in journal (Refereed)
    Abstract [en]

    The diffusion of viruses at the cell membrane is essential to reach a suitable entry site and initiate subsequent internalization. Although many viruses take advantage of glycosaminoglycans (GAG) to bind to the cell surface, little is known about the dynamics of the virus–GAG interactions. Here, single-particle tracking of the initial interaction of individual herpes simplex virus 1 (HSV-1) virions reveals a heterogeneous diffusive behavior, regulated by cell-surface GAGs with two main diffusion types: confined and normal free. This study reports that different GAGs can have competing influences in mediating diffusion on the cells used here: chondroitin sulfate (CS) enhances free diffusion but hinders virus attachment to cell surfaces, while heparan sulfate (HS) promotes virus confinement and increases entry efficiency. In addition, the role that the viral mucin-like domains (MLD) of the HSV-1 glycoprotein C plays in facilitating the diffusion of the virus and accelerating virus penetration into cells is demonstrated. Together, our results shed new light on the mechanisms of GAG-regulated virus diffusion at the cell surface for optimal internalization. These findings may be extendable to other GAG-binding viruses.

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  • 11.
    Abrahamsson, Karolina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Detektion av herpesvirus i hjärnvävnad med q-PCR: Utvärdering av KAPA Express Extract kit och KAPA PROBE FORCE q-PCR kit2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 12. Achouiti, Ahmed
    et al.
    Vogl, Thomas
    Urban, Constantin F
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Röhm, Marc
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Hommes, Tijmen J
    van Zoelen, Marieke AD
    Florquin, Sandrine
    Roth, Johannes
    van't Veer, Cornelis
    de Vos, Alex F
    van der Poll, Tom
    Myeloid-related protein-14 contributes to protective immunity in gram-negative pneumonia derived sepsis2012In: PLoS Pathogens, ISSN 1553-7374, Vol. 8, no 10, p. e1002987-Article in journal (Refereed)
    Abstract [en]

    Klebsiella (K.) pneumoniae is a common cause of pneumonia-derived sepsis. Myeloid related protein 8 (MRP8, S100A8) and MRP14 (S100A9) are the most abundant cytoplasmic proteins in neutrophils. They can form MRP8/14 heterodimers that are released upon cell stress stimuli. MRP8/14 reportedly exerts antimicrobial activity, but in acute fulminant sepsis models MRP8/14 has been found to contribute to organ damage and death. We here determined the role of MRP8/14 in K. pneumoniae sepsis originating from the lungs, using an established model characterized by gradual growth of bacteria with subsequent dissemination. Infection resulted in gradually increasing MRP8/14 levels in lungs and plasma. Mrp14 deficient (mrp14(-/-)) mice, unable to form MRP8/14 heterodimers, showed enhanced bacterial dissemination accompanied by increased organ damage and a reduced survival. Mrp14(-/-) macrophages were reduced in their capacity to phagocytose Klebsiella. In addition, recombinant MRP8/14 heterodimers, but not MRP8 or MRP14 alone, prevented growth of Klebsiella in vitro through chelation of divalent cations. Neutrophil extracellular traps (NETs) prepared from wildtype but not from mrp14(-/-) neutrophils inhibited Klebsiella growth; in accordance, the capacity of human NETs to kill Klebsiella was strongly impaired by an anti-MRP14 antibody or the addition of zinc. These results identify MRP8/14 as key player in protective innate immunity during Klebsiella pneumonia.

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  • 13.
    Achour, Cyrinne
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Bhattarai, Devi Prasad
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Esteva-Socias, Margalida
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Rodriguez-Barrueco, Ruth
    Malla, Sandhya
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Seier, Kerstin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Marchand, Virginie
    Motorine, Yuri
    Lundin, Eva
    Umeå University, Faculty of Medicine, Department of Medical Biosciences.
    Gilthorpe, Jonathan D.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Marzese, Diego Matias
    Bally, Marta
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Roman, Angel-Carlos
    Pich, Andreas
    Aguilo, Francesca
    Reshaping the role of METTL3 in breast tumorigenesisManuscript (preprint) (Other academic)
  • 14. Adler, Sara
    et al.
    Widerström, Micael
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Lindh, Johan
    Lilja, Mikael
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Symptoms and risk factors of Cryptosporidium hominis infection in children: data from a large waterborne outbreak in Sweden2017In: Parasitology Research, ISSN 0932-0113, E-ISSN 1432-1955, Vol. 116, no 10, p. 2613-2618Article in journal (Refereed)
    Abstract [en]

    Cryptosporidium is a major cause of diarrheal disease worldwide. In developing countries, this infection is endemic and in children, associated with growth faltering and cognitive function deficits, with the most severe impact on those aged <2 years. Little has been reported about symptoms and risk factors for children in industrialized countries, although the disease incidence is increasing in such regions. In November 2010, a large waterborne outbreak of C. hominis occurred in the city of Östersund in Sweden. Approximately 27,000 of the 60,000 inhabitants were symptomatic. We aimed to describe duration of symptoms and the risk factors for infection with C. hominis in children aged <15 years in a Western setting. Within 2 months after a boil water advisory, a questionnaire was sent to randomly selected inhabitants of all ages, including 753 children aged <15 years. Those with ≥3 loose stools/day were defined as cases of diarrhoea. The response rate was 70.3%, and 211 children (39.9%) fulfilled the case definition. Mean duration of diarrhoea was 7.5 days (median 6, range 1-80 days). Recurrence, defined as a new episode of diarrhoea after ≥2 days of normal stools, occurred in 52.5% of the cases. Significant risk factors for infection, besides living within the distribution area of the contaminated water plant, included a high level of water consumption, male sex, and a previous history of loose stools. The outbreak was characterized by high attack and recurrence rates, emphasizing the necessity of water surveillance to prevent future outbreaks.

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  • 15. Affognon, H.
    et al.
    Mburu, P.
    Hassan, Osama Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Kingori, S.
    Ahlm, C.
    Sang, R.
    Evander, M.
    Sociocultural differences affect Rift Valley fever exposureManuscript (preprint) (Other academic)
  • 16. Affognon, Hippolyte
    et al.
    Mburu, Peter
    Hassan, Osama Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Kingori, Sarah
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Sang, Rosemary
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Ethnic groups' knowledge, attitude and practices and Rift Valley fever exposure in Isiolo County of Kenya2017In: PLoS Neglected Tropical Diseases, ISSN 1935-2727, E-ISSN 1935-2735, Vol. 11, no 3, article id e0005405Article in journal (Refereed)
    Abstract [en]

    Rift Valley fever (RVF) is an emerging mosquito-borne viral hemorrhagic fever in Africa and the Arabian Peninsula, affecting humans and livestock. For spread of infectious diseases, including RVF, knowledge, attitude and practices play an important role, and the understanding of the influence of behavior is crucial to improve prevention and control efforts. The objective of the study was to assess RVF exposure, in a multiethnic region in Kenya known to experience RVF outbreaks, from the behavior perspective. We investigated how communities in Isiolo County, Kenya were affected, in relation to their knowledge, attitude and practices, by the RVF outbreak of 2006/2007. A cross-sectional study was conducted involving 698 households selected randomly from three different ethnic communities. Data were collected using a structured questionnaire regarding knowledge, attitudes and practices that could affect the spread of RVF. In addition, information was collected from the communities regarding the number of humans and livestock affected during the RVF outbreak. This study found that better knowledge about a specific disease does not always translate to better practices to avoid exposure to the disease. However, the high knowledge, attitude and practice score measured as a single index of the Maasai community may explain why they were less affected, compared to other investigated communities (Borana and Turkana), by RVF during the 2006/2007 outbreak. We conclude that RVF exposure in Isiolo County, Kenya during the outbreak was likely determined by the behavioral differences of different resident community groups. We then recommend that strategies to combat RVF should take into consideration behavioral differences among communities.

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  • 17. Afset, J. E.
    et al.
    Larssen, K. W.
    Bergh, K.
    Larkeryd, A.
    Sjodin, A.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Forsman, M.
    Phylogeographical pattern of Francisella tularensis in a nationwide outbreak of tularaemia in Norway, 20112015In: Eurosurveillance, ISSN 1025-496X, E-ISSN 1560-7917, Vol. 20, no 19, p. 9-14, article id 21125Article in journal (Refereed)
    Abstract [en]

    In 2011, a nationwide outbreak of tularaemia occurred in Norway with 180 recorded cases. It was associated with the largest peak in lemming density seen in 40 years. Francisella tularensis was isolated from 18 patients. To study the geographical distribution of F. tularensis genotypes in Norway and correlate genotype with epidemiology and clinical presentation, we performed whole genome sequencing of patient isolates. All 18 genomes from the outbreak carried genetic signatures of F. tularensis subsp. holarctica and were assigned to genetic clades using canonical single nucleotide polymorphisms. Ten isolates were assigned to major genetic clade B.6 (subclade B.7), seven to clade B.12, and one to clade B.4. The B.6 subclade B.7 was most common in southern and central Norway, while clade B.12 was evenly distributed between the southern, central and northern parts of the country. There was no association between genotype and clinical presentation of tularaemia, time of year or specimen type. We found extensive sequence similarity with F. tularensis subsp. holarctica genomes from high-endemic tularaemia areas in Sweden. Finding nearly identical genomes across large geographical distances in Norway and Sweden imply a life cycle of the bacterium without replication between the outbreaks and raise new questions about long-range migration mechanisms.

  • 18.
    Agerhäll, Martin
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Otorhinolaryngology.
    Henrikson, Martin
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Otorhinolaryngology.
    Johansson Söderberg, Jenny
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Sellin, Mats
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Tano, Krister
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Otorhinolaryngology.
    Gylfe, Åsa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Berggren, Diana
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Otorhinolaryngology.
    High prevalence of pharyngeal bacterial pathogens among healthy adolescents and young adults2021In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 129, no 12, p. 711-716Article in journal (Refereed)
    Abstract [en]

    The pharyngeal mucosa can be colonized with bacteria that have potential to cause pharyngotonsillitis. By the use of culturing techniques and PCR, we aimed to assess the prevalence of bacterial pharyngeal pathogens among healthy adolescents and young adults. We performed a cross-sectional study in a community-based cohort of 217 healthy individuals between 16 and 25 years of age. Samples were analyzed for Group A streptococci (GAS), Group C/G streptococci (SDSE), Fusobacterium necrophorum, and Arcanobacterium haemolyticum. Compared to culturing, the PCR method resulted in more frequent detection, albeit in most cases with low levels of DNA, of GAS (20/217 vs. 5/217; p < 0.01) and F. necrophorum (20/217 vs. 8/217; p < 0.01). Culturing and PCR yielded similar rates of SDSE detection (14/217 vs. 12/217; p = 0.73). Arcanobacterium haemolyticum was rarely detected (3/217), and only by PCR. Overall, in 25.3% (55/217) of these healthy adolescents and young adults at least one of these pathogens was detected, a rate that is higher than previously described. Further studies are needed before clinical adoption of PCR-based detection methods for pharyngeal bacterial pathogens, as our findings suggest a high incidence of asymptomatic carriage among adolescents and young adults without throat infections.

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  • 19. Agmon-Levin, Nancy
    et al.
    Damoiseaux, Jan
    Kallenberg, Cees
    Sack, Ulrich
    Witte, Torsten
    Herold, Manfred
    Bossuyt, Xavier
    Musset, Lucille
    Cervera, Ricard
    Plaza-Lopez, Aresio
    Dias, Carlos
    Sousa, Maria Jose
    Radice, Antonella
    Eriksson, Catharina
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Hultgren, Olof
    Viander, Markku
    Khamashta, Munther
    Regenass, Stephan
    Coelho Andrade, Luis Eduardo
    Wiik, Allan
    Tincani, Angela
    Ronnelid, Johan
    Bloch, Donald B.
    Fritzler, Marvin J.
    Chan, Edward K. L.
    Garcia-De la Torre, I.
    Konstantinov, Konstantin N.
    Lahita, Robert
    Wilson, Merlin
    Vainio, Olli
    Fabien, Nicole
    Sinico, Renato Alberto
    Meroni, Pierluigi
    Shoenfeld, Yehuda
    International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies2014In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 73, no 1, p. 17-23Article in journal (Refereed)
    Abstract [en]

    Anti-nuclear antibodies (ANA) are fundamental for the diagnosis of autoimmune diseases, and have been determined by indirect immunofluorescence assay (IIFA) for decades. As the demand for ANA testing increased, alternative techniques were developed challenging the classic IIFA. These alternative platforms differ in their antigen profiles, sensitivity and specificity, raising uncertainties regarding standardisation and interpretation of incongruent results. Therefore, an international group of experts has created recommendations for ANA testing by different methods. Two groups of experts participated in this initiative. The European autoimmunity standardization initiative representing 15 European countries and the International Union of Immunologic Societies/World Health Organization/Arthritis Foundation/Centers for Disease Control and Prevention autoantibody standardising committee. A three-step process followed by a Delphi exercise with closed voting was applied. Twenty-five recommendations for determining ANA (1-13), anti-double stranded DNA antibodies (14-18), specific antibodies (19-23) and validation of methods (24-25) were created. Significant differences between experts were observed regarding recommendations 24-25 (p<0.03). Here, we formulated recommendations for the assessment and interpretation of ANA and associated antibodies. Notably, the roles of IIFA as a reference method, and the importance of defining nuclear and cytoplasmic staining, were emphasised, while the need to incorporate alternative automated methods was acknowledged. Various approaches to overcome discrepancies between methods were suggested of which an improved bench-to-bedside communication is of the utmost importance. These recommendations are based on current knowledge and can enable harmonisation of local algorithms for testing and evaluation of ANA and related autoantibodies. Last but not least, new more appropriate terminologies have been suggested.

  • 20. Ahlinder, Jon
    et al.
    Ohrman, Caroline
    Svensson, Kerstin
    Lindgren, Petter
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Forsman, Mats
    Larsson, Pär
    Sjödin, Andreas
    Increased knowledge of Francisella genus diversity highlights the benefits of optimised DNA-based assays2012In: BMC Microbiology, E-ISSN 1471-2180, Vol. 12, p. 220-Article in journal (Refereed)
    Abstract [en]

    Background: Recent advances in sequencing technologies offer promising tools for generating large numbers of genomes, larger typing databases and improved mapping of environmental bacterial diversity. However, DNA-based methods for the detection of Francisella were developed with limited knowledge about genetic diversity. This, together with the high sequence identity between several Francisella species, means there is a high risk of false identification and detection of the highly virulent pathogen Francisella tularensis. Moreover, phylogenetic reconstructions using single or limited numbers of marker sequences often result in incorrect tree topologies and inferred evolutionary distances. The recent growth in publicly accessible whole-genome sequences now allows evaluation of published genetic markers to determine optimal combinations of markers that minimise both time and laboratory costs. Results: In the present study, we evaluated 38 previously published DNA markers and the corresponding PCR primers against 42 genomes representing the currently known diversity of the genus Francisella. The results highlight that PCR assays for Francisella tularensis are often complicated by low specificity, resulting in a high probability of false positives. A method to select a set of one to seven markers for obtaining optimal phylogenetic resolution or diagnostic accuracy is presented. Conclusions: Current multiple-locus sequence-typing systems and detection assays of Francisella, could be improved by redesigning some of the primers and reselecting typing markers. The use of only a few optimally selected sequence-typing markers allows construction of phylogenetic topologies with almost the same accuracy as topologies based on whole-genome sequences.

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  • 21.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Distribution of puumala virus in Sweden1997Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Puumala virus, belonging to the genus hantavirus, is the causative agent of nephropathia epidemica (NE), a relatively mild form of hemorrhagic fever with renal syndrome. Puumala virus occurs endemically in Central and Northern Europe and Western Russia. In Sweden, NE is reported from the northern and central parts but virtually not at all from the southern part of the country. The bank vole (Clethrionomys glareolus) is the main reservoir of Puumala virus and humans are infected by inhalation of aerosolized animal secreta. In northern Sweden, the density of the bank vole population varies cyclically in intervals of 3-4 years and the incidence of NE shows a covariation.

    The prevalence of serum antibodies to hantaviruses in northern Sweden was studied in a stratified and randomly selected adult population sample comprising 1538 subjects. As expected, the prevalence increased with age. There was no difference between men and women, which was unexpected based on a male:female ratio of > 2:1 in clinical reports. By use of an immunofiuorescent assay, a seroprevalence of 5.4% and by a newly developed enzyme-linked immunosorbent assay (ELISA) with recombinant Puumala virus nucleocapsid protein as antigen, a prevalence of 8.9% was recorded. This is about or more than ten times higher than what would be calculated from clinical reports.

    By use of the ELISA, an occupational risk of acquisition of Puumala virus infection was demonstrated. Serum samples from 910 farmers and 663 referent subjects living in various rural parts of Sweden were tested. Among farmers from the Puumala virus-endemic northern and central parts of the country, the seroprevalence (12.9%) was higher (p=0.01) than in referents (6.8%). In the southern part of Sweden, only 2/459 persons had antibodies. Only a limited number of children with NE had been previously reported. In a separate study, 32 children with Puumala virus infection were identified and the clinical picture of NE in children was found to be similar to that of adult cases.

    Variations in the prevalence of Puumala virus in the bank vole population within an endemic region are not well known. Here, a higher mean rodent density and a higher prevalence of Puumala virus-specific serum antibodies were recorded in the vicinity of households afflicted with NE than in rural control areas. The data indicated that the risk of exposure locally within an endemic region may vary widely and tentatively suggested that a threshold density of bank voles might be necessary to achieve before effective spread of Puumala virus within the rodent population may occur.

    There is no firm evidence of the occurrence of Puumala virus among wild living animals other than rodents. A study of Swedish moose, an animal which is ecologically well characterized, was performed. Convincing evidence of past Puumala virus infection was found in 5/260 moose originating from Puumala virus-endemic areas but in none of 167 animals from nonendemic areas. Based on the low seroprevalence recorded, moose seemed to serve as endstage hosts rather than being active parts of the enzootic circle of transmission.

    In conclusion, the present investigations confirmed that the exposure to Puumala virus is geographically well restricted in Sweden. Seroprevalence studies indicated that only a minor proportion of individuals infected with Puumala virus are clinically reported, with a bias in favour of men. NE was confirmed to occur in children, with a clinical picture similar to that of adults. An occupational risk was defined for acquisition of Puumala virus infection. Studies in rodents suggested that there may be wide local variations within a limited area in the risk of exposure to Puumala virus. The studies validated the usefulness of a newly developed ELISA based on recombinant nucleocapsid peptides of hantaviruses and finally, methodological progress was reached when Puumala virus was, for the first time, successfully isolated from a Scandinavian patient.

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  • 22.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Norrländska infektionssjukdomar2011In: Infektionssjukdomar: Epidemiologi, klinik, terapi / [ed] Ivarsson-Norrby, Sundbyberg: Säve förlag , 2011, 5Chapter in book (Other academic)
  • 23.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Alexeyev, O A
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Aava, Birgitta
    Wadell, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Tärnvik, Arne
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Palo, T
    High prevalence of hantavirus antibodies in bank voles (Clethrionomys glareolus) captured in the vicinity of households afflicted with nephropathia epidemica.1997In: American Journal of Tropical Medicine and Hygiene, ISSN 0002-9637, E-ISSN 1476-1645, Vol. 56, no 6, p. 674-8Article in journal (Refereed)
    Abstract [en]

    Puumala virus, the causative agent of nephropathia epidemica (NE), occurs endemically in Europe and is spread mainly by the bank vole (Clethrionomys glareolus). In the vicinity of each of four households afflicted with NE, we studied rodents with regard to population density and prevalence of Puumala virus-specific antibodies. For each case area, a control area was randomly selected 10 km away, without regard to the presence of human settlement. During 6,000 trap nights, 328 rodents were caught, of which 299 were C. glareolus. The mean rodent densities of case and control areas were 6.6 and 3.7 animals per 100 trap nights (P < 0.001). The prevalence of serum antibodies was 15.9% in case areas compared with 5.6% in control areas (P < 0.05). In three of the case areas, where NE had occurred 3-10 weeks before trapping, the rodent density and seroprevalence were much higher than in the fourth area, where NE occurred 38 weeks before trapping. In conclusion, C. glareolus seropositive for Puumala virus occurred more frequently near households afflicted with NE than in control areas 10 km away.

  • 24.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Axelsson, I
    Jansson, B
    [Maternal health care must improve its tracing of hepatitis B virus carriers].1990In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 87, no 37, p. 2865-6Article in journal (Refereed)
  • 25.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Eliasson, Mats
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Vapalahti, O.
    University of Helsinki and Helsinki University Central Hospital Laboratory, Finland.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Seroprevalence of Sindbis virus and associated risk factors in northern Sweden2014In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 142, no 7, p. 1559-1565Article in journal (Refereed)
    Abstract [en]

    Mosquito-borne Sindbis virus (SINV) cause disease characterized by rash, fever and arthritis which often leads to long-lasting arthralgia. To determine the seroprevalence of SINV and associated risk factors in northern Sweden, a randomly selected population aged between 25 and 74 years were invited to join the MONICA study. Serum from 1611 samples were analysed for specific IgG antibodies. Overall, 2·9% had IgG against SINV. More men (3·7%) than women (2·0%) were SINV seropositive (P = 0·047) and it was more common in subjects with a lower educational level (P = 0·013) and living in small, rural communities (P < 0·001). Seropositivity was associated with higher waist circumference (P = 0·1), elevated diastolic blood pressure (P = 0·037), and history of a previous stroke (P = 0·011). In a multiple logistic regression analysis, adjusting for known risk factors for stroke, seropositivity for SINV was an independent predictor of having had a stroke (odds ratio 4·3, 95% confidence interval 1·4–13·0,P = 0·011).

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  • 26.
    Ahlm, Clas
    et al.
    Infektionskliniken, Norrlands universitetssjukhus, Umeå, Sweden.
    Evander, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Section of Virology.
    Missfall orsakades av det myggburna Rift Valley-feberviruset2016In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 113, no 42, article id EAUZArticle in journal (Other academic)
  • 27.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Herlitz, H
    Säll, C
    Eriksson, C
    Settergren, B
    [Is vole fever (nephropathia epidemica) spreading in the south of Sweden?].1992In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 89, no 40, p. 3275-Article in journal (Refereed)
  • 28.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Juto, Per
    Settergren, Bo
    [Nephropathia epidemica--a current disease in Norrland].1990In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 87, no 43, p. 3521-2, 3527Article in journal (Refereed)
  • 29.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Stegmayr, Birgitta
    Settergren, Bo
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Wadell, Göran
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Tärnvik, Arne
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Prevalence of serum antibodies to hantaviruses in northern Sweden as measured by recombinant nucleocapsid proteins.1997In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 29, no 4, p. 349-54Article in journal (Refereed)
    Abstract [en]

    An enzyme-linked immunosorbent assay (ELISA) based on recombinant nucleocapsid protein (rN delta) (aa 1-117) of Hantaan, Seoul, Dobrava, Sin Nombre and Puumala hantaviruses was used to determine the prevalence of antibodies among randomized and stratified individuals from northern Sweden. In total, 137/1533 individuals (8.9%) had specific serum IgG antibodies to Puumala virus, the only hantavirus known to occur in the region. The prevalence of antibodies to Puumala virus (8.9%) was determined to be higher than previously reported (5.4%) in the same serum material, by use of immunofluorescence assay. As expected, sera reactive to Puumala virus rN delta did frequently cross-react with Sin Nombre virus protein. Unexpectedly, 21/1533 (1.4%) individuals recognized the Sin Nombre virus rN delta exclusively. Another 8 subjects showed reactivity in the ELISA to Hantaan, Seoul, or Dobrava virus-derived rN delta but not Puumala virus or Sin Nombre virus rN delta. The present demonstration in some individuals of antibodies specifically recognizing the Sin Nombre, Dobrava, Hantaan and Seoul virus protein justifies an awareness of the possibility that hantaviruses antigenically different from Puumala virus might occur in the region.

  • 30.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Linderholm, Mats
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Stegmayr, Birgitta
    Settergren, Bo
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Prevalence of serum IgG antibodies to Puumala virus (haemorrhagic fever with renal syndrome) in northern Sweden.1994In: Epidemiology and Infection, ISSN 0950-2688, E-ISSN 1469-4409, Vol. 113, no 1, p. 129-36Article in journal (Refereed)
    Abstract [en]

    A stratified and randomly-selected population sample was identified in 1990 in order to study the seroprevalence of nephropathia epidemica (haemorrhagic fever with renal syndrome) in Northern Sweden. Sera from 1538 subjects (750 men, 788 women), 25-64 years of age, were analysed for the presence of Puumala virus (PUV) specific-IgG by the indirect immunofluorescence antibody test. Specific IgG was detected in sera from 83 subjects (5.4%). Men and women had similar seroprevalence rates. The highest seroprevalences were found in subjects 55 years or older (8.0%) and among farmers and forestry workers (15.9%). The geographic distribution of seropositive individuals was uneven and there were significantly more seropositive persons in rural than in urban areas (P < 0.05).

  • 31.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Lindén, Christina
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Ophthalmology.
    Linderholm, M
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Alexeyev, O A
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Billheden, J
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Fagerlund, M
    Zetterlund, B
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neurophysiology.
    Settergren, B
    Central nervous system and ophthalmic involvement in nephropathia epidemica (European type of haemorrhagic fever with renal syndrome)1998In: Journal of Infection, ISSN 0163-4453, E-ISSN 1532-2742, Vol. 36, no 2, p. 149-155Article in journal (Refereed)
    Abstract [en]

    Central nervous system (CNS) - related symptoms occur in haemorrhagic fever with renal syndrome (HFRS). To study the CNS and ophthalmic involvement in nephropathia epidemica (NE), the European type of HFRS, we included 26 patients in a prospective study. Most common CNS-related symptoms were headache (96%), insomnia (83%), vertigo (79%), nausea (79%), and vomiting (71%). Ophthalmic symptoms were reported by 82% of patients; 41% had photophobia and 50% had impaired vision. A transient loss of vision was recorded in one patient, who also had a generalized seizure. Minor white matter lesions were found in about half of the patients investigated with brain magnetic resonance imaging (MRI). Electroencephalography (EEG) showed severe alterations in only one patient, and slight and reversible patterns in another two patients. Neopterin, interleukin-6 and interferon-gamma levels in the cerebrospinal fluid (CSF) were elevated, which may indicate immune activation. However, we found no evidence of intrathecal NE virus replication. We conclude that CNS-related symptoms are common in NE, and transient ophthalmic involvement can be demonstrated in about half of the patients.

  • 32.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Lundberg, Sonia
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Fessé, Kerstin
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Wiström, Johan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Health problems and self-medication among Swedish travellers.1994In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 26, no 6, p. 711-7Article in journal (Refereed)
    Abstract [en]

    500 consecutive travellers seeking pre-travel health advice were issued a questionnaire before leaving Sweden to continuously record health problems and use of medication during travel. Of 442 subjects who turned in assessable questionnaires (232 male and 210 female, mean age 37 years), 81% travelled to areas at high risk for the acquisition of diarrhea. The mean duration of travel was 4 weeks. During travel 218 (49% at 95% CI 44.3 to 53.7%) of the travellers experienced some illness and 61 (14%) had symptoms of more than one illness. The mean duration of illness was 4.5 days, and 65 subjects (30% of ill travellers) were confined to bed for a mean duration of 2 days. The incidence of illness was significantly (p < 0.01) higher among travellers to high risk than to low risk areas (55% vs 26%), among young travellers than among elderly (65% vs 33%), and among those going on adventure tours compared with recreational tourists (74% vs 41%). Diarrhea was reported by 36% (95% CI 31.6 to 40.5%), and respiratory tract infection by 21% (95% CI 17.2 to 24.8%). Self-medication with one or several drugs was initiated by 163 (75%) travellers experiencing illness during travel. Thus, every second Swedish traveller to tropical and subtropical areas experienced some kind of travel-related, often incapacitating, health problem.

  • 33.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Olsen, Björn
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Koskinen, Lars Ove
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurosurgery.
    Monsen, Tor
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology.
    Brain abscess caused by methicillin-resistant Staphylococcus aureus2000In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 32, no 5, p. 562-563Article in journal (Refereed)
    Abstract [en]

    A Swedish tourist was admitted to a Cuban hospital due to epileptic seizures caused by brain tumors. Upon return to Sweden and admission to our hospital, methicillin-resistant Staphylococcus aureus (MRSA) was isolated. He was later considered to be free of MRSA but then developed a brain abscess from which MRSA was isolated.

  • 34.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Settergren, Bo
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Gothefors, Leif
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Juto, Per
    Nephropathia epidemica (hemorrhagic fever with renal syndrome) in children: clinical characteristics.1994In: The Pediatric Infectious Disease Journal, ISSN 0891-3668, E-ISSN 1532-0987, Vol. 13, no 1, p. 45-9Article in journal (Refereed)
    Abstract [en]

    The clinical characteristics of serologically verified nephropathia epidemica, the Scandinavian form of hemorrhagic fever with renal syndrome, were studied in Swedish children who were < 15 years of age. In 1990 to 1992, 14 cases were prospectively followed. A retrospective survey during 1984 to 1990 disclosed another 18 cases. Among the 32 cases (20 boys, 12 girls, 3 to 15 years of age; median age, 11 years), the most common symptoms were fever (100%), headache (100%), abdominal pain (93%), vomiting (91%) and back pain (76%). Laboratory findings included elevated serum creatinine concentration (19 of 28) and thrombocytopenia (7 of 22). Urinalysis showed proteinuria (31 of 31 patients) and hematuria (24 of 30). Six children had mild hemorrhagic manifestations (epistaxis, metrorrhagia, and petechiae). No severe complications occurred. The clinical symptoms of children with nephropathia epidemica seem to be similar to those found among adult nephropathia epidemica cases.

  • 35.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Thelin, Anders
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Stiernström, E L
    Holmberg, S
    Tärnvik, Arne
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Prevalence of antibodies specific to Puumala virus among farmers in Sweden1998In: Scandinavian Journal of Work, Environment and Health, ISSN 0355-3140, E-ISSN 1795-990X, Vol. 24, no 2, p. 104-108Article in journal (Refereed)
    Abstract [en]

    Serological evidence confirmed that the exposure of humans to Puumala virus is firmly restricted to the northern and central parts of Sweden. In addition the evidence indicated that, in this region, farming is associated with an increased risk of contracting hantavirus infection.

  • 36.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Wallin, Kjell
    Skoglig zooekologi, SLU, Umeå.
    Lundkvist, Åke
    Smittskyddsinstitutet.
    Elgh, Fredrik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Juto, Per
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology.
    Merza, Malik
    Virologi, SVA, Uppsala.
    Tärnvik, Arne
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Serologic evidence of Puumala virus infection in wild moose in northern Sweden2000In: American Journal of Tropical Medicine and Hygiene, ISSN 0002-9637, E-ISSN 1476-1645, Vol. 62, no 1, p. 106-111Article in journal (Refereed)
    Abstract [en]

    Puumala (PUU) virus is the causative agent of nephropathia epidemica, the Scandinavian form of hemorrhagic fever with renal syndrome. The infection is acquired by airborne transmission of PUU virus from its rodent reservoir, the bank vole. Besides serologic data indicating that the virus may spread also to heterologous rodents, there is little information on the susceptibility of wild living animals to PUU virus. We studied the occurrence of antibodies to PUU virus in serum samples from 427 wild-living moose, of which 260 originated from the PUU virus-endemic northern and central parts of Sweden and 167 originated from the southern, nonendemic part of Sweden. Samples from 5 animals showed reactivity in an ELISA for recombinant PUU virus nucleocapsid protein, an immunofluorescent assay, and a neutralization test. These 5 animals all originated from the PUU virus-endemic northern part of Sweden. In conclusion, 5 of 260 moose from the endemic region showed convincing serologic evidence of past PUU virus infection. The seroprevalence was low, suggesting that the moose is subjected to endstage infection rather than being part of an enzootic transmission cycle.

  • 37.
    Ahlm, Clas
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Wiström, Johan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Carlsson, Hans
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Infectious Diseases.
    Chloroquine-Resistant Plasmodium vivax Malaria in Borneo.1996In: Journal of Travel Medicine, ISSN 1195-1982, E-ISSN 1708-8305, Vol. 3, no 2, p. 124-Article in journal (Refereed)
  • 38.
    Ahmad, Irma
    et al.
    Department of Radiation Oncology, Stanford University, Stanford, CA, United States.
    Edin, Alicia
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Granvik, Christoffer
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Kumm Persson, Lowa
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Tevell, Staffan
    Department of Infectious Diseases, Karlstad Hospital, Karlstad, Sweden; Centre for Clinical Research and Education, Region Värmland, Karlstad, Sweden; School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Månsson, Emeli
    Centre for Clinical Research, Region Västmanland—Uppsala University, Västmanland Hospital Västerås, Västerås, Sweden.
    Magnuson, Anders
    Center for Clinical Epidemiology and Biostatistics, Faculty of Medicine and Health, School of Medical Sciences, Örebro University, Örebro, Sweden.
    Marklund, Ingela
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation. Centre for Clinical Research and Education, Region Värmland, Karlstad, Sweden.
    Persson, Ida-Lisa
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Kauppi, Anna
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Ahlm, Clas
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Forsell, Mattias N. E.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Sundh, Josefin
    Department of Respiratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
    Lange, Anna
    Department of Radiation Oncology, Stanford University, Stanford, CA, United States.
    Cajander, Sara
    Department of Radiation Oncology, Stanford University, Stanford, CA, United States.
    Normark, Johan
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    High prevalence of persistent symptoms and reduced health-related quality of life 6 months after COVID-192023In: Frontiers In Public Health, ISSN 2296-2565, Vol. 11, article id 1104267Article in journal (Refereed)
    Abstract [en]

    Background: The long-term sequelae after COVID-19 constitute a challenge to public health and increased knowledge is needed. We investigated the prevalence of self-reported persistent symptoms and reduced health-related quality of life (HRQoL) in relation to functional exercise capacity, 6 months after infection, and explored risk factors for COVID-19 sequalae. Methods: This was a prospective, multicenter, cohort study including 434 patients. At 6 months, physical exercise capacity was assessed by a 1-minute sit-to-stand test (1MSTST) and persistent symptoms were reported and HRQoL was evaluated through the EuroQol 5-level 5-dimension (EQ-5D-5L) questionnaire. Patients with both persistent symptoms and reduced HRQoL were classified into a new definition of post-acute COVID syndrome, PACS+. Risk factors for developing persistent symptoms, reduced HRQoL and PACS+ were identified by multivariable Poisson regression. Results: Persistent symptoms were experienced by 79% of hospitalized, and 59% of non-hospitalized patients at 6 months. Hospitalized patients had a higher prevalence of self-assessed reduced overall health (28 vs. 12%) and PACS+ (31 vs. 11%). PACS+ was associated with reduced exercise capacity but not with abnormal pulse/desaturation during 1MSTST. Hospitalization was the most important independent risk factor for developing persistent symptoms, reduced overall health and PACS+. Conclusion: Persistent symptoms and reduced HRQoL are common among COVID-19 survivors, but abnormal pulse and peripheral saturation during exercise could not distinguish patients with PACS+. Patients with severe infection requiring hospitalization were more likely to develop PACS+, hence these patients should be prioritized for clinical follow-up after COVID-19.

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  • 39.
    Ahmad, Sajjad
    et al.
    Institute of Basic Medical Science, Khyber Medical University, KP, Peshawar, Pakistan.
    Ahmed, Jawad
    Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan.
    Khalifa, Eman H.
    Al Baha University Faculty of Applied Medical Sciences, Saudi Arabia.
    Khattak, Farhad Ali
    Research & development Cell, Khyber College of Dentistry (KCD), Peshawar, Pakistan.
    khan, Anwar Sheed
    Provincial TB Reference laboratory, Hayatabad Medical Complex, PK, Peshawar, Pakistan.
    Farooq, Syed Umar
    Department of oral pathology, Khyber College of Dentistry, Peshawar, Pakistan.
    Osman, Sannaa M.A.
    Alzaiem Alazhari University Faculty of Medicine, Sudan.
    Salih, Magdi M.
    Taif University College of Science, Saudi Arabia.
    Ullah, Nadeem
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Khan, Taj Ali
    Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, Pakistan; Division of Infectious Diseases & Global Medicine,Department of Medicine, University of Florida, FL, Gainesville, United States.
    Novel mutations in genes of the IL-12/IFN-γ axis cause susceptibility to tuberculosis2023In: Journal of Infection and Public Health, ISSN 1876-0341, E-ISSN 1876-035X, Vol. 16, no 9, p. 1368-1378Article in journal (Refereed)
    Abstract [en]

    Background: The IL-12/23/ISG15-IFN-γ pathway is the main immunological pathway for controlling intra-macrophagic microorganisms such as Mycobacteria, Salmonella, and Leishmania spp. Consequently, upon mutations in genes of the IL-12/23/ISG15-IFN-γ pathway cause increased susceptibility to intra-macrophagic pathogens, particularly to Mycobacteria. Therefore, the purpose of this study was to characterize the mutations in genes of the IL-12/23/ISG15-IFN-γ pathway in severe tuberculosis (TB) patients.

    Methods: Clinically suspected TB was initially confirmed in four patients (P) (P1, P2, P3, and P4) using the GeneXpert MTB/RIF and culturing techniques. The patients' Peripheral blood mononuclear cells (PBMCs) were then subjected to ELISA to measure Interleukin 12 (IL-12) and interferon gamma (IFN-γ). Flow cytometry was used to detect the surface expressions of IFN-γR1 and IFN-γR2 as well as IL-12Rβ1and IL-12Rβ2 on monocytes and T lymphocytes, respectively.The phosphorylation of signal transducer and activator of transcription 1(STAT1) on monocytes and STAT4 on T lymphocytes were also detected by flow cytometry. Sanger sequencing was used to identify mutations in the IL-12Rβ1, STAT1, NEMO, and CYBB genes.

    Results: P1's PBMCs exhibited reduced IFN-γ production, while P2's and P3's PBMCs exhibited impaired IL-12 induction. Low IL-12Rβ1 surface expression and reduced STAT4 phosphorylation were demonstrated by P1's T lymphocytes, while impaired STAT1 phosphorylation was detected in P2's monocytes. The impaired IκB-α degradation and abolished H2O2 production in monocytes and neutrophils of P3 and P4 were observed, respectively. Sanger sequencing revealed novel nonsense homozygous mutation: c.191 G>A/p.W64 * in exon 3 of the IL-12Rβ1 gene in P1, novel missense homozygous mutation: c.107 A>T/p.Q36L in exon 3 of the STAT1 gene in P2, missense hemizygous mutation:: c.950 A>C/p.Q317P in exon 8 of the NEMO gene in P3, and nonsense hemizygous mutation: c.868 C>T/p.R290X in exon 8 of CYBB gene in P4.

    Conclusion: Our findings broaden the clinical and genetic spectra associated with IL-12/23/ISG15-IFN-γ axis anomalies. Additionally, our data suggest that TB patients in Pakistan should be investigated for potential genetic defects due to high prevalence of parental consanguinity and increased incidence of TB in the country.

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  • 40.
    Ahmed, Ahmed Hussein Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Metodjämförelse mellan laboratoriebaserat instrument och tre patientnära tester vid drogscreening av urin2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 41.
    Ahmed Hassan Ahmed, Osama
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Virology. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Rift Valley fever: challenges and new insights for prevention and control using the “One Health” approach2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rift Valley fever (RVF) is an emerging viral zoonosis that causes frequent outbreaks in east Africa and on the Arabian Peninsula. The likelihood of RVF global expansion due to climate change and human anthropogenic factors is an important issue. The causative agent, RVF virus, is an arbovirus that is transmitted by several mosquito species and is able to infect a wide range of livestock as well as people. The infection leads to mass abortions and death in livestock and a potentially deadly hemorrhagic fever in humans. RVF has severe socio-economic consequences such as animal trade bans between countries, disruption of food security, and economic disaster for farmers and pastoralists as well as for countries. Human behavior such as direct contact with infected animals or their fluids and exposure to mosquito bites increases the risk for contracting the disease.

    To better understand the challenges associated with RVF outbreaks and to explore prevention and control strategies, we used the One Health approach. The local community had to be involved to understand the interaction between the environment, animals, and humans. We focused on Sudan, Saudi Arabia, and Kenya. First, we systematically reviewed the literature and then we performed cross sectional community-based studies using a special One Health questionnaire. Climatic and remote sensing data were used in combination with statistics to develop a sub-region predictive model for RVF.

    For both Saudi Arabia and Sudan, the ecology and environment of the affected areas were similar. These areas included irrigation canals and excessive rains that provide an attractive habitat for mosquito vectors to multiply. The surveillance systems were unable to detect the virus in livestock before it spread to humans. Ideally, livestock should serve as sentinels to prevent loss of human lives, but the situation here was reversed. Differences between countries regarding further spread of RVF was mainly determined by better economic and infrastructure resources.

    In Sudan, there was a lack of knowledge and appropriate practices at the studied community regarding RVF disease symptoms and risk factors for both animals and humans. The community was hesitant in notifying the authorities about RVF suspicion in livestock due to the lack of a compensation system. The perceived role of the community in controlling RVF was fragmented, increasing the probability of RVF transmission and disease.

    In Kenya, our study found that better knowledge about RVF does not always translate to more appropriate practices that avoid exposure to the disease. However, the combination of good knowledge, attitudes, and practices may explain why certain communities were less affected. Strategies to combat RVF should consider socio-cultural and behavioral differences among communities. We also noticed that RVF outbreaks in Kenya occurred in regions with high livestock density exposed to heavy rains and wet soil fluxes, which could be measured by evapotranspiration and vegetation seasonality variables. We developed a RVF risk map on a sub-regional scale. Future outbreaks could be better managed if such relevant RVF variables are integrated into early warning systems.

    To confront RVF outbreaks, a policy is needed that better incorporates ecological factors and human interactions with livestock and environment that help the RVF pathogen spread. Early detection and notification of RVF is essential because a delay will threaten the core of International Health Regulations (IHR), which emphasizes the share of information during a transboundary disease outbreak to avoid unnecessary geographical expansion.

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  • 42.
    Akula, Ilona
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Hjärtfunktion vid ärftlig transtyretin-amyloidos: Jämförelse av hjärtfrekvensvariabilitet och ekokardiografi mellan två amyloidfibrilltyper2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 43.
    Al Rabiey, Ahmed
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Detektion av aktin i paraffinsnitt från human vävnad2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 44.
    Alam, Athar
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Bröms, Jeanette E
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Kumar, Rajender
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Sjöstedt, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    The Role of ClpB in Bacterial Stress Responses and Virulence2021In: Frontiers in Molecular Biosciences, E-ISSN 2296-889X, Vol. 8, article id 668910Article, review/survey (Refereed)
    Abstract [en]

    Bacterial survival within a mammalian host is contingent upon sensing environmental perturbations and initiating an appropriate counter-response. To achieve this, sophisticated molecular machineries are used, where bacterial chaperone systems play key roles. The chaperones are a prerequisite for bacterial survival during normal physiological conditions as well as under stressful situations, e.g., infection or inflammation. Specific stress factors include, but are not limited to, high temperature, osmolarity, pH, reactive oxidative species, or bactericidal molecules. ClpB, a member of class 1 AAA+ proteins, is a key chaperone that via its disaggregase activity plays a crucial role for bacterial survival under various forms of stress, in particular heat shock. Recently, it has been reported that ClpB also regulates secretion of bacterial effector molecules related to type VI secretion systems. In this review, the roles of ClpB in stress responses and the mechanisms by which it promotes survival of pathogenic bacteria are discussed.

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  • 45.
    Alam, Athar
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Golovliov, Igor
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Javed, Eram
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Kumar, Rajender
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Ådén, Jörgen
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sjöstedt, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Bacteriology. Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Dissociation between the critical role of ClpB of Francisella tularensis for the heat shock response and the DnaK interaction and its important role for efficient type VI secretion and bacterial virulence2020In: PLoS Pathogens, ISSN 1553-7366, E-ISSN 1553-7374, Vol. 16, no 4, p. 1-27, article id e1008466Article in journal (Refereed)
    Abstract [en]

    Author summary Type VI secretion systems (T6SSs) are essential virulence determinants of many Gram-negative pathogens, including Francisella tularensis. This highly virulent bacterium encodes an atypical T6SS lacking ClpV, the ATPase crucial for prototypic T6SS sheath disassembly. It, however, possesses ClpB, a protein critical for heat shock survival via its interaction with DnaK. Since ClpB possesses ATPase activity, it has been hypothesized to provide a compensatory function for the absence of ClpV, a hypothesis supported by the recent findings from us and others. Here, we investigated how F. tularensis ClpB controls T6S. In silico modelling of the ClpB-DnaK complex identified key interactions that were experimentally verified. For example, mutating one of the DnaK-interacting residues rendered the bacterium exquisitely susceptible to heat shock, but had no effect on T6S and virulence. In contrast, removing the N-terminal of ClpB only had a slight effect on the heat shock response, but strongly compromised both T6S and virulence. Intriguingly, the Escherichia coli ClpB could fully complement the function of F. tularensis ClpB. The data demonstrate that the two critical roles of ClpB, mediating heat shock survival and effective T6S, are dissociated and that the N-terminal is crucial for T6S and virulence. Francisella tularensis, a highly infectious, intracellular bacterium possesses an atypical type VI secretion system (T6SS), which is essential for its virulence. The chaperone ClpB, a member of the Hsp100/Clp family, is involved in Francisella T6SS disassembly and type VI secretion (T6S) is impaired in its absence. We asked if the role of ClpB for T6S was related to its prototypical role for the disaggregation activity. The latter is dependent on its interaction with the DnaK/Hsp70 chaperone system. Key residues of the ClpB-DnaK interaction were identified by molecular dynamic simulation and verified by targeted mutagenesis. Using such targeted mutants, it was found that the F. novicida ClpB-DnaK interaction was dispensable for T6S, intracellular replication, and virulence in a mouse model, although essential for handling of heat shock. Moreover, by mutagenesis of key amino acids of the Walker A, Walker B, and Arginine finger motifs of each of the two Nucleotide-Binding Domains, their critical roles for heat shock, T6S, intracellular replication, and virulence were identified. In contrast, the N-terminus was dispensable for heat shock, but required for T6S, intracellular replication, and virulence. Complementation of the Delta clpB mutant with a chimeric F. novicida ClpB expressing the N-terminal of Escherichia coli, led to reconstitution of the wild-type phenotype. Collectively, the data demonstrate that the ClpB-DnaK interaction does not contribute to T6S, whereas the N-terminal and NBD domains displayed critical roles for T6S and virulence.

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  • 46.
    Alam, Athar
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Golovliov, Igor
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Javed, Eram
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    Sjöstedt, Anders
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology.
    ClpB mutants of Francisella tularensis subspecies holarctica and tularensis are defective for type VI secretion and intracellular replication2018In: Scientific Reports, E-ISSN 2045-2322, Vol. 8, article id 11324Article in journal (Refereed)
    Abstract [en]

    Francisella tularensis, a highly infectious, intracellular bacterium possesses an atypical type VI secretion system (T6SS), which is essential for the virulence of the bacterium. Recent data suggest that the HSP100 family member, ClpB, is involved in T6SS disassembly in the subspecies Francisella novicida. Here, we investigated the role of ClpB for the function of the T6SS and for phenotypic characteristics of the human pathogenic subspecies holarctica and tularensis. The Delta clpB mutants of the human live vaccine strain, LVS, belonging to subspecies holarctica, and the highly virulent SCHU S4 strain, belonging to subspecies tularensis, both showed extreme susceptibility to heat shock and low pH, severely impaired type VI secretion (T6S), and significant, but impaired intracellular replication compared to the wild-type strains. Moreover, they showed essentially intact phagosomal escape. Infection of mice demonstrated that both Delta clpB mutants were highly attenuated, but the SCHU S4 mutant showed more effective replication than the LVS strain. Collectively, our data demonstrate that ClpB performs multiple functions in the F. tularensis subspecies holarctica and tularensis and its function is important for T6S, intracellular replication, and virulence.

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  • 47.
    Alavuotunki, Meiju-Maari
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science.
    Utveckling av små heterocykler vilka inhiberar gonokocker, MRSA och VRE2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 48. Alberione, Maria Pia
    et al.
    Moeller, Rebecca
    Kirui, Jared
    Ginkel, Corinne
    Doepke, Mandy
    Stroeh, Luisa J.
    Machtens, Jan-Philipp
    Pietschmann, Thomas
    Gerold, Gisa
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Section of Virology. Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany.
    Single-nucleotide variants in human CD81 influence hepatitis C virus infection of hepatoma cells2020In: Medical Microbiology and Immmunology, ISSN 0300-8584, E-ISSN 1432-1831, Vol. 209, no 4, p. 499-514Article in journal (Refereed)
    Abstract [en]

    An estimated number of 71 million people are living with chronic hepatitis C virus (HCV) infection worldwide and 400,000 annual deaths are related to the infection. HCV entry into the hepatocytes is complex and involves several host factors. The tetraspanin human CD81 (hCD81) is one of the four essential entry factors and is composed of one large extracellular loop, one small extracellular loop, four transmembrane domains, one intracellular loop and two intracellular tails. The large extracellular loop interacts with the E2 glycoprotein of HCV. Regions outside the large extracellular loop (backbone) of hCD81 have a critical role in post-binding entry steps and determine susceptibility of hepatocytes to HCV. Here, we investigated the effect of five non-synonymous single-nucleotide variants in the backbone of hCD81 on HCV susceptibility. We generated cell lines that stably express the hCD81 variants and infected the cells using HCV pseudoparticles and cell culture-derived HCV. Our results show that all the tested hCD81 variants support HCV pseudoparticle entry with similar efficiency as wild-type hCD81. In contrast, variants A54V, V211M and M220I are less supportive to cell culture-derived HCV infection. This altered susceptibility is HCV genotype dependent and specifically affected the cell entry step. Our findings identify three hCD81 genetic variants that are impaired in their function as HCV host factors for specific viral genotypes. This study provides additional evidence that genetic host variation contributes to inter-individual differences in HCV infection and outcome.

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  • 49.
    Albertsson, Jakob
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Biomedical Laboratory Science. Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Effekt av förbehandling vid detektion av muterat superoxiddismutas-1 protein: Immunohistokemisk detektion av SOD1 aggregat hos G93A transgena möss2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 50.
    Alenius, Gerd-Marie
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jidell, Erik
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Nordmark, L
    Rantapää Dahlqvist, Solbritt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Reumatology.
    Disease manifestations and HLA antigens in psoriatic arthritis in northern Sweden2002In: Clinical Rheumatology, ISSN 0770-3198, E-ISSN 1434-9949, Vol. 21, no 5, p. 357-362Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to identify potential markers of aggressive joint manifestations and HLA associations in patients with psoriatic arthritis (PsA) in northern Sweden. Patients with PsA were examined clinically, with laboratory tests and radiologically. The classification of the disease was based on peripheral and/or axial engagement. HLA B17, B37 and B62 were significantly increased in PsA patients. Univariate analyses suggest that the HLA antigens B37, B62 and some clinical variables were associated with disease course. However, in multivariate analyses distal interphalangeal joint affliction and polyarticular manifestations were the only variables remaining significantly associated with irreversible joint destruction or deformity. There were no significant effects of HLA antigens. In this cross-sectional study, clinical manifestations were more reliable predictors of aggressive joint damage than were specific HLA antigens. However, HLA antigens seemed to modify the expression of the joint disease rather than being involved in joint disease susceptibility.

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