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Widerström, Micael, Docent, Lektor klinisk mikrobiologi
Alternative names
Publications (10 of 43) Show all publications
Gibbs, A., Maripuu, M., Öhlund, L., Widerström, M., Nilsson, N. H. & Werneke, U. (2024). COVID-19-associated mortality in individuals with serious mental disorders in Sweden during the first two years of the pandemic: a population-based register study. BMC Psychiatry, 24(1), Article ID 189.
Open this publication in new window or tab >>COVID-19-associated mortality in individuals with serious mental disorders in Sweden during the first two years of the pandemic: a population-based register study
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2024 (English)In: BMC Psychiatry, E-ISSN 1471-244X, Vol. 24, no 1, article id 189Article in journal (Refereed) Published
Abstract [en]

Background: Reports at the beginning of the COVID-19 pandemic suggested differences in COVID-19-associated mortality between individuals with serious mental disorders (SMD) and the population at large.

Aim: To compare the pattern of COVID-19-associated mortality in individuals with and without SMD in Sweden over the two main pandemic years.

Methods: We compared the pattern of COVID-19-associated mortality in individuals with and without SMD in Sweden during 2020 and 2021. For SMD, we included psychotic disorder, bipolar disorder, and severe depression. The analysis was based on summary data from the Swedish Board of Health and Welfare covering the entire adult Swedish population.

Results: The overall relative risk (RR) for experiencing a COVID-19-associated death was 1.66 (CI 1.50–1.83; p < 0.001) for individuals with SMD versus individuals without SMD. The corresponding RRs were 3.25 (CI 2.84–3.71; p < 0.001) for individuals with psychotic disorder, 1.06 (CI 0.88–1.26; p = 0.54) for individuals with bipolar disorder, and 1.03 (CI 0.80–1.32; p = 0.80) for individuals with severe depression. Compared to their respective counterparts in the non-SMD group, in the psychotic disorder and severe depression group, the RR were higher in women than in men. In the bipolar disorder group, the RR was higher in men than in women. The RR of COVID-19-associated death was generally higher in younger individuals with SMD. Individuals with psychosis between 18 and 59 years had the highest RR of COVID-19-associated death with 7.25 (CI 4.54–11.59; p<0.001).

Conclusions: Individuals with SMD, and particularly those with psychotic disorders, had a higher risk of COVID-19-associated death than the general population. As this is a pattern also seen with other infections, people with SMD may be similarly vulnerable in future pandemics.

Place, publisher, year, edition, pages
BioMed Central (BMC), 2024
Keywords
Bipolar disorder, Coronavirus, COVID-19, Death, Depressive disorder, Mental disorder, Mortality, Psychosis, Psychotic disorder, Risk factor
National Category
Psychiatry Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-222411 (URN)10.1186/s12888-024-05629-y (DOI)38454398 (PubMedID)2-s2.0-85187127555 (Scopus ID)
Funder
Norrbotten County Council, NLL-982498Region Jämtland Härjedalen, JLL-940151Umeå University
Available from: 2024-03-22 Created: 2024-03-22 Last updated: 2024-03-22Bibliographically approved
Fischerstrom, K., Dryselius, R., Lindblad, M., Kuhlmann-Berenzon, S., Karamehmedovic, N., Borjesson, S., . . . Rehn, M. (2024). Outbreak of salmonella typhimurium linked to swedish pre-washed rocket salad, Sweden, September to November 2022. Eurosurveillance, 29(10), Article ID 2300299.
Open this publication in new window or tab >>Outbreak of salmonella typhimurium linked to swedish pre-washed rocket salad, Sweden, September to November 2022
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2024 (English)In: Eurosurveillance, ISSN 1025-496X, E-ISSN 1560-7917, Vol. 29, no 10, article id 2300299Article in journal (Refereed) Published
Abstract [en]

In September 2022, the Public Health Agency of Sweden observed an increase in domestic Salmonella Typhimurium cases through the Swedish electronic notification system, and an outbreak strain was identified with whole genome sequencing. Overall, 109 cases with symptom onset between 17 September and 24 November 2022 were reported from 20 of 21 Swedish regions. The median age of cases was 52 years (range 4-87 years) and 62% were female. A case-control study found cases to be associated with consumption of rocket salad (adjusted odds ratio (aOR) = 4.9; 95% confidence interval (CI): 2.4-10, p value < 0.001) and bagged mixed salad (aOR = 4.0; 95% CI: 1.9-8.1, p value < 0.001). Traceback, supported by Finnish authorities who identified the Swedish outbreak strain in a Finnish cluster during the same time period, identified rocket salad, cultivated, pre-washed and pre-packed in Sweden as the likely source of the outbreak. No microbiological analyses of rocket salad were performed. Our investigation indicates that bagged leafy greens such as rocket salad, regardless of pre-washing procedures in the production chain, may contain Salmonella and cause outbreaks, posing a health risk to consumers. We emphasise the need for primary producers of leafy greens to identify possible contamination points to prevent outbreaks.

Place, publisher, year, edition, pages
European Centre for Disease Control and Prevention (ECDC), 2024
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-222572 (URN)10.2807/1560-7917.ES.2024.29.10.2300299 (DOI)38456218 (PubMedID)2-s2.0-85187527748 (Scopus ID)
Available from: 2024-04-08 Created: 2024-04-08 Last updated: 2024-04-08Bibliographically approved
Widerström, M., Mörtberg, S., Magnusson, M., Fjällström, P. & Johansson, A. (2024). Treatment outcome of severe respiratory type B tularemia using fluoroquinolones. Clinical Infectious Diseases, 78, S38-S46
Open this publication in new window or tab >>Treatment outcome of severe respiratory type B tularemia using fluoroquinolones
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2024 (English)In: Clinical Infectious Diseases, ISSN 1058-4838, E-ISSN 1537-6591, Vol. 78, p. S38-S46Article in journal (Refereed) Published
Abstract [en]

Background: Fluoroquinolones lack approval for treatment of tularemia but have been used extensively for milder illness. Here, we evaluated fluoroquinolones for severe illness.

Methods: In an observational study, we identified case-patients with respiratory tularemia from July to November 2010 in Jämtland County, Sweden. We defined severe tularemia by hospitalization for >24 hours and severe bacteremic tularemia by Francisella tularensis subsp. holarctica growth in blood or pleural fluid. Clinical data and drug dosing were retrieved from electronic medical records. Chest images were reexamined. We used Kaplan-Meier curves to evaluate time to defervescence and hospital discharge.

Results: Among 67 case-patients (median age, 66 years; 81% males) 30-day mortality was 1.5% (1 of 67). Among 33 hospitalized persons (median age, 71 years; 82% males), 23 had nonbacteremic and 10 had bacteremic severe tularemia. Subpleural round consolidations, mediastinal lymphadenopathy, and unilateral pleural fluid were common on chest computed tomography. Among 29 hospitalized persons with complete outcome data, ciprofloxacin/levofloxacin (n = 12), ciprofloxacin/levofloxacin combinations with doxycycline and/or gentamicin (n = 11), or doxycycline as the single drug (n = 6) was used for treatment. One disease relapse occurred with doxycycline treatment. Treatment responses were rapid, with median fever duration 41.0 hours in nonbacteremic and 115.0 hours in bacteremic tularemia. Increased age-adjusted Charlson comorbidity index predicted severe bacteremic tularemia (odds ratio, 2.7 per score-point; 95% confidence interval, 1.35-5.41). A 78-year-old male with comorbidities and delayed ciprofloxacin/gentamicin treatment died.

Conclusions: Fluoroquinolone treatment is effective for severe tularemia. Subpleural round consolidations and mediastinal lymphadenopathy were typical findings on computed tomography among case-patients in this study.

Place, publisher, year, edition, pages
Oxford University Press, 2024
Keywords
computed tomography, fluoroquinolone/therapeutic use, treatment outcome, tularemia/drug therapy, X ray
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-220852 (URN)10.1093/cid/ciad690 (DOI)001154832000010 ()38294118 (PubMedID)2-s2.0-85183755279 (Scopus ID)
Funder
Region Jämtland HärjedalenRegion Västerbotten
Note

Special issue, supplement_1

Available from: 2024-02-20 Created: 2024-02-20 Last updated: 2024-02-20Bibliographically approved
Andersson Norlén, E., Widerström, M., Lindam, A., Olsson, J. & Ryding, U. (2023). Blood cultures with one venipuncture instead of two: a prospective clinical comparative single-center study including patients in the ICU, haematology, and infectious diseases departments. Infectious Diseases, 55(9), 591-598
Open this publication in new window or tab >>Blood cultures with one venipuncture instead of two: a prospective clinical comparative single-center study including patients in the ICU, haematology, and infectious diseases departments
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2023 (English)In: Infectious Diseases, ISSN 2374-4235, E-ISSN 2374-4243, Vol. 55, no 9, p. 591-598Article in journal (Refereed) Published
Abstract [en]

Objectives: Blood culture is a key method for diagnosing bloodstream infections. In this prospective study, we aimed to investigate whether blood cultures collected with the one-puncture method results in fewer contaminants, i.e. microorganisms from the skin or the environment, and the same detection of relevant pathogens compared to the two-puncture method. Further, we aimed to investigate if the time to blood culture positivity could be useful in evaluating contaminants.

Methods: Patients planned for blood cultures were asked to participate in the study. From each recruited patient, six blood culture bottles were drawn, bottles 1–4 from the first venipuncture and bottles 5–6 from the second venipuncture. Within each patient, bottles 1–4 were compared to bottles 1, 2, 5, and 6 for contaminants and relevant pathogens. A sub-analysis was conducted on patients admitted to the ICU and those in the haematology department. We also assessed time-to-positivity for coagulase-negative staphylococci.

Results: In the final analysis, 337 episodes from 312 patients were included. Relevant pathogens were identified in 62/337 (18.4%) episodes in both methods. Contaminants were detected in 12 (3.6%) and 19 episodes (5.6%) using the one-puncture and two-puncture method (p =.039), respectively. Corresponding results were observed in the sub-analysis. Notably, relevant coagulase-negative staphylococci demonstrated a shorter time-to-positivity compared to contaminant coagulase-negative staphylococci.

Conclusion: Blood cultures obtained using the one-puncture method resulted in significantly fewer contaminants and detected relevant pathogens equally to the two-puncture method. Time-to-positivity may be a useful additive indicator for predicting coagulase-negative staphylococci contamination in blood cultures.

Place, publisher, year, edition, pages
Taylor & Francis, 2023
Keywords
bacteraemia, blood culture(s), Blood stream infection, one-puncture method, single sampling strategy, time-to-positivity
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-210884 (URN)10.1080/23744235.2023.2223281 (DOI)001008427000001 ()37317789 (PubMedID)2-s2.0-85161885515 (Scopus ID)
Available from: 2023-07-24 Created: 2023-07-24 Last updated: 2023-09-05Bibliographically approved
Hedman, E., Fohlin, L., Hellmark, B., Aspevall, O. & Widerström, M. (2023). Fem fall av C canimorsus på kort tid vid Östersunds sjukhus: [Five cases of C. canimorsus during a short period of time at Östersund Hospital, Sweden]. Läkartidningen, 120, Article ID 22150.
Open this publication in new window or tab >>Fem fall av C canimorsus på kort tid vid Östersunds sjukhus: [Five cases of C. canimorsus during a short period of time at Östersund Hospital, Sweden]
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2023 (Swedish)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 120, article id 22150Article in journal (Refereed) Published
Abstract [en]

We report a sudden increase in the number of cases of C. canimorsus bacteremia during 3 months in 2022 at Östersund Hospital, Sweden. Prior to these cases, the most recent one in the region occurred in 2015. Among the five cases, one suffered from meningitis and one was diagnosed as endocarditis. Dog contact was present in all cases, although dog bites could only be verified in two. Improved diagnostics could not be an explanation to the surge, since the analysis method for blood culture had been the same since 2015. No corresponding increase was noted nationally, according to the Public Health Agency of Sweden. The isolates have been included in the ongoing global study with the aim to explore Capnocytophaga in humans and animals using comparative genomics and genome wide association studies. The study is supported by several ESCMID (European Society of Clinical Microbiology and Infectious Diseases) study groups.

Abstract [sv]

Sepsis orsakad av Capnocytophaga canimorsus  förekommer även hos individer som inte är immunsup­primerade. Majoriteten av dem som drabbas har nyligen haft kontakt med hund, men hundbett är inte nödvändigt. Blododlingar före antibiotikabehandling är avgörande för diagnostiken. Förstahandsbehandling vid hundbett är cefotaxim vid allvarlig infektion och amoxicillin–klavulansyra vid peroral behandling. C canimorsus är inte känslig för flukloxacillin. Rapporteringssystemet Svebar kan ge information om förekomsten av olika patogener på de mikrobiologiska laboratorierna.

Place, publisher, year, edition, pages
Läkartidningen förlag AB, 2023
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-206449 (URN)2-s2.0-85151042664 (Scopus ID)
Available from: 2023-04-13 Created: 2023-04-13 Last updated: 2023-04-13Bibliographically approved
Persson Waller, K., Myrenås, M., Börjesson, S., Kim, H., Widerström, M., Monsen, T. J., . . . Cha, W. (2023). Genotypic characterization of Staphylococcus chromogenes and Staphylococcus simulans from Swedish cases of bovine subclinical mastitis. Journal of Dairy Science, 106(11), 7991-8004
Open this publication in new window or tab >>Genotypic characterization of Staphylococcus chromogenes and Staphylococcus simulans from Swedish cases of bovine subclinical mastitis
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2023 (English)In: Journal of Dairy Science, ISSN 0022-0302, E-ISSN 1525-3198, Vol. 106, no 11, p. 7991-8004Article in journal (Refereed) Published
Abstract [en]

Staphylococcus chromogenes and Staphylococcus simulans are commonly found in intramammary infections (IMI) associated with bovine subclinical mastitis, but little is known about genotypic variation and relatedness within species. This includes knowledge about genes encoding antimicrobial resistance (AMR) and potential virulence factors (pVF). The aim of this study was therefore to investigate these aspects by whole-genome sequencing of milk isolates from Swedish dairy cows with subclinical mastitis in an observational study. We also wanted to study if specific genotypes were associated with persistent IMI and the inflammatory response at udder quarter level. In total, 105 and 118 isolates of S. chromogenes and S. simulans, respectively, were included. Isolates were characterized using a 7-locus multilocus sequence typing (7-MLST), core genome analysis and in-silico analysis of AMR and pVF genes. Forty-seven sequence types (ST) and 7 core genome clusters of S. chromogenes were identified, and the most common ST were ST-6 and ST-109, both belonging to cluster VII. A 7-locus MLST scheme for S. simulans was not available, but 3 core genome clusters and 5 subclusters were described. Overall, substantial variation in ST and clusters among cows and herds were found in both species. Some ST of S. chromogenes were found in several herds, indicating spread between herds. Moreover, within-herd spread of the same genotype was observed for both species. Only a few AMR genes [blaZ, strpS194, vga(A)] were detected in a limited number of isolates, with the exception of blaZ coding for β-lactamase, which was identified in 22% of the isolates of S. chromogenes with ST-19, ST-102, and ST-103 more commonly carrying this gene compared with other ST. However, the blaZ gene was not identified in S. simulans. The average total number of pVF detected per isolate was similar in S. chromogenes (n = 30) and S. simulans (n = 33), but some variation in total numbers and presence of specific pVF or functional groups of pVF, was shown between ST/clusters within species. Differences in inflammatory response and potentially in persistent IMI at udder quarter level were found between S. chromogenes subtypes but not between S. simulans subtypes. In conclusion, the results from the present study generates new insight into the epidemiology of bovine S. chromogenes and S. simulans IMI, which can have implications for future prevention and antimicrobial treatment of infections related to these species.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
antimicrobial resistance, multilocus sequence typing, non-aureus staphylococci, virulence factors, whole-genome sequencing
National Category
Genetics
Identifiers
urn:nbn:se:umu:diva-215925 (URN)10.3168/jds.2023-23523 (DOI)2-s2.0-85174664205 (Scopus ID)
Funder
Swedish Research Council Formas, 2018-01043
Available from: 2023-11-02 Created: 2023-11-02 Last updated: 2023-11-02Bibliographically approved
Boks, M., Lilja, M., Widerström, M., Karling, P., Lindam, A. & Sjöström, M. (2023). Persisting symptoms after Cryptosporidium hominis outbreak: a 10-year follow-up from Östersund, Sweden. Parasitology Research, 122(7), 1631-1639
Open this publication in new window or tab >>Persisting symptoms after Cryptosporidium hominis outbreak: a 10-year follow-up from Östersund, Sweden
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2023 (English)In: Parasitology Research, ISSN 0932-0113, E-ISSN 1432-1955, Vol. 122, no 7, p. 1631-1639Article in journal (Refereed) Published
Abstract [en]

In late 2010, an outbreak of Cryptosporidium hominis affected 27,000 inhabitants (45%) of Östersund, Sweden. Previous research shows that abdomen and joint symptoms commonly persist up to 5 years post-infection. It is unknown whether Cryptosporidium is associated with sequelae for a longer duration, how persisting symptoms present over time, and whether sequelae are associated with prolonged infection. In this prospective cohort study, a randomly selected cohort in Östersund was surveyed about cryptosporidiosis symptoms in 2011 (response rate 69.2%). A case was defined as a respondent reporting new diarrhoea episodes during the outbreak. Follow-up questionnaires were sent after 5 and 10 years. Logistic regressions were used to examine associations between case status and symptoms reported after 10 years, with results presented as adjusted odds ratios (aOR) with 95% confidence intervals. Consistency of symptoms and associations with case status and number of days with symptoms during outbreak were analysed using X 2 and Mann–Whitney U tests. The response rate after 10 years was 74% (n = 538). Case status was associated with reporting symptoms, with aOR of ~3 for abdominal symptoms and ~2 for joint symptoms. Cases were more likely to report consistent symptoms. Cases with consistent abdominal symptoms at follow-up reported 9.2 days with symptoms during the outbreak (SD 8.1), compared to 6.6 days (SD 6.1) for cases reporting varying or no symptoms (p = 0.003). We conclude that cryptosporidiosis was associated with an up to threefold risk for reporting symptoms 10 years post-infection. Consistent symptoms were associated with prolonged infection.

Place, publisher, year, edition, pages
Springer Nature, 2023
Keywords
Cryptosporidium, Diarrhoea, Disease outbreaks, PI-IBS, Post-infectious symptoms, Sequelae
National Category
Infectious Medicine Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:umu:diva-209290 (URN)10.1007/s00436-023-07866-8 (DOI)000990476700002 ()37199767 (PubMedID)2-s2.0-85159654199 (Scopus ID)
Funder
Region Jämtland Härjedalen, JLL-939404Region Jämtland Härjedalen, JLL-965542Region Jämtland Härjedalen, JLL-967794Region Jämtland Härjedalen, JLL-978075Region Jämtland Härjedalen, JLL-980156Visare Norr, 967799
Available from: 2023-06-08 Created: 2023-06-08 Last updated: 2023-12-05Bibliographically approved
Blom, K., Fjällström, P., Molnár, C., Åberg, M., Vikström, L., Wigren, J., . . . Johansson, A. (2023). SARS-CoV-2-related mortality decrease in nursing home residents given multiple COVID-19 boosters [Letter to the editor]. The Lancet - Infectious diseases, 23(10), e393-e394
Open this publication in new window or tab >>SARS-CoV-2-related mortality decrease in nursing home residents given multiple COVID-19 boosters
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2023 (English)In: The Lancet - Infectious diseases, ISSN 1473-3099, E-ISSN 1474-4457, Vol. 23, no 10, p. e393-e394Article in journal, Letter (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2023
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-215072 (URN)10.1016/S1473-3099(23)00548-0 (DOI)37716359 (PubMedID)2-s2.0-85172367341 (Scopus ID)
Available from: 2023-10-13 Created: 2023-10-13 Last updated: 2024-01-17Bibliographically approved
Vikström, L., Fjällström, P., Gwon, Y.-D., Sheward, D. J., Wigren-Byström, J., Evander, M., . . . Forsell, M. N. E. (2023). Vaccine-induced correlate of protection against fatal COVID-19 in older and frail adults during waves of neutralization-resistant variants of concern: an observational study. The Lancet Regional Health: Europe, 30, Article ID 100646.
Open this publication in new window or tab >>Vaccine-induced correlate of protection against fatal COVID-19 in older and frail adults during waves of neutralization-resistant variants of concern: an observational study
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2023 (English)In: The Lancet Regional Health: Europe, E-ISSN 2666-7762, Vol. 30, article id 100646Article in journal (Refereed) Published
Abstract [en]

Background: To inform future preventive measures including repeated vaccinations, we have searched for a clinically useful immune correlate of protection against fatal COVID-19 among nursing homes residents.

Methods: We performed repeated capillary blood sampling with analysis of S-binding IgG in an open cohort of nursing home residents in Sweden. We analyzed immunological and registry data from 16 September 2021 to 31 August 2022 with follow-up of deaths to 30 September 2022. The study period included implementation of the 3rd and 4th mRNA monovalent vaccine doses and Omicron virus waves.

Findings: A total of 3012 nursing home residents with median age 86 were enrolled. The 3rd mRNA dose elicited a 99-fold relative increase of S-binding IgG in blood and corresponding increase of neutralizing antibodies. The 4th mRNA vaccine dose boosted levels 3.8-fold. Half-life of S-binding IgG was 72 days. A total 528 residents acquired their first SARS-CoV-2 infection after the 3rd or the 4th vaccine dose and the associated 30-day mortality was 9.1%. We found no indication that levels of vaccine-induced antibodies protected against infection with Omicron VOCs. In contrast, the risk of death was inversely correlated to levels of S-directed IgG below the 20th percentile. The death risk plateaued at population average above the lower 35th percentile of S-binding IgG.

Interpretation: In the absence of neutralizing antibodies that protect from infection, quantification of S-binding IgG post vaccination may be useful to identify the most vulnerable for fatal COVID-19 among the oldest and frailest. This information is of importance for future strategies to protect vulnerable populations against neutralization resistant variants of concern.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Correlate of protection, COVID-19, Immune monitoring of vulnerable populations, Longevity of vaccination, Open cohort study, Vaccination, Vulnerable population
National Category
Infectious Medicine Immunology in the medical area
Identifiers
urn:nbn:se:umu:diva-208263 (URN)10.1016/j.lanepe.2023.100646 (DOI)2-s2.0-85156247971 (Scopus ID)
Funder
Swedish Research CouncilScience for Life Laboratory, SciLifeLabKnut and Alice Wallenberg FoundationVinnovaSwedish Association of Local Authorities and RegionsFamiljen Erling-Perssons Stiftelse
Available from: 2023-05-24 Created: 2023-05-24 Last updated: 2023-07-14Bibliographically approved
Widerström, M., Stegger, M., Johansson, A., Gurram, B. K., Larsen, A. R., Wallinder, L., . . . Monsen, T. (2022). Heterogeneity of Staphylococcus epidermidis in prosthetic joint infections: time to reevaluate microbiological criteria?. European Journal of Clinical Microbiology and Infectious Diseases, 41, 87-97
Open this publication in new window or tab >>Heterogeneity of Staphylococcus epidermidis in prosthetic joint infections: time to reevaluate microbiological criteria?
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2022 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 41, p. 87-97Article in journal (Refereed) Published
Abstract [en]

Prosthetic joint infection (PJI) is a feared and challenging to diagnose complication after arthroplasty, with Staphylococcus epidermidis as the major pathogen. One important criteria to define PJI is the detection of phenotypically indistinguishable microorganisms with identical antibiotic susceptibility pattern in at least two different samples. However, owing to phenotypical variation within genetic clones and clonal variation within a phenotype, the criteria may be ambiguous. We investigated the extent of diversity among coagulase-negative staphylococci (CoNS) in PJI and characterised S. epidermidis isolates from PJI samples, specifically multiple S. epidermidis isolates identified in individual PJI patients. We performed a retrospective cohort study on 62 consecutive patients with PJI caused by CoNS from two hospitals in Northern Sweden. In 16/62 (26%) PJIs, multiple S. epidermidis isolates were available for whole-genome analyses. Hospital-adapted multidrug-resistant genetic clones of S. epidermidis were identified in samples from 40/62 (65%) of the patients using a combination of pulsed-field gel electrophoresis and multilocus sequence typing. Whole-genome sequencing showed the presence of multiple sequence types (STs) in 7/16 (44%) PJIs where multiple S. epidermidis isolates were available. Within-patient phenotypical variation in the antibiotic susceptibility and/or whole-genome antibiotic resistance gene content was frequent (11/16, 69%) among isolates with the same ST. The results highlight the ambiguity of S. epidermidis phenotypic characterisation as a diagnostic method in PJI and call for larger systematic studies for determining the frequency of CoNS diversity in PJIs, the implications of such diversity for microbiological diagnostics, and the therapeutic outcomes in patients.

Place, publisher, year, edition, pages
Springer, 2022
Keywords
Staphylococcus epidermidis, Genomics, Multidrug resistant, Prosthetic joint infection, Within-patient variation, Diagnosis, Polymicrobial
National Category
Infectious Medicine
Identifiers
urn:nbn:se:umu:diva-188180 (URN)10.1007/s10096-021-04352-w (DOI)000702789200001 ()34599708 (PubMedID)2-s2.0-85116301940 (Scopus ID)
Funder
Region VästerbottenSwedish Society of Medicine, SLS-24993, SLS-413681
Available from: 2021-10-04 Created: 2021-10-04 Last updated: 2022-07-12Bibliographically approved
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