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Öhman, Ulla
Publications (2 of 2) Show all publications
Esberg, A., Löfgren-Burström, A., Öhman, U. & Strömberg, N. (2012). Host and bacterial phenotype variation in adhesion of streptococcus mutans to matched human hosts. Infection and Immunity, 80(11), 3869-3879
Open this publication in new window or tab >>Host and bacterial phenotype variation in adhesion of streptococcus mutans to matched human hosts
2012 (English)In: Infection and Immunity, ISSN 0019-9567, E-ISSN 1098-5522, Vol. 80, no 11, p. 3869-3879Article in journal (Refereed) Published
Abstract [en]

The commensal pathogen Streptococcus mutans uses AgI/II adhesins to adhere to gp340 adsorbed on teeth. Here we analyzed isolates of S. mutans (n = 70 isolates) from caries and caries-free human extremes (n = 19 subjects) by multilocus sequence typing (MLST), AgI/II full-length gene sequencing, and adhesion to parotid saliva matched from the strain donors (nested from a case-control sample of defined gp340 and acidic proline-rich protein [PRP] profiles). The concatenated MLST as well as AgI/II gene sequences showed unique sequence types between, and identical types within, the subjects. The matched adhesion levels ranged widely (40% adhesion range), from low to moderate to high, between subjects but were similar within subjects (or sequence types). In contrast, the adhesion avidity of the strains was narrow, normally distributed for high, moderate, or low adhesion reference saliva or pure gp340 regardless of the sequence type. The adhesion of S. mutans Ingbritt and matched isolates and saliva samples correlated (r = 0.929), suggesting that the host specify about four-fifths (r(2) = 0.86) of the variation in matched adhesion. Half of the variation in S. mutans Ingbritt adhesion to saliva from the caries cases-controls (n = 218) was explained by the primary gp340 receptor and PRP coreceptor composition. The isolates also varied, although less so, in adhesion to standardized saliva (18% adhesion range) and clustered into three major AgI/II groups (groups A, B-1, and B-2) due to two variable V-region segments and diverse AgI/II sequence types due to a set of single-amino-acid substitutions. Isolates with AgI/II type A versus types B-1 and B-2 tended to differ in gp340 binding avidity and qualitative adhesion profiles for saliva gp340 phenotypes. In conclusion, the host saliva phenotype plays a more prominent role in S. mutans adhesion than anticipated previously.

Place, publisher, year, edition, pages
Washington: American Society Microbiology, 2012
National Category
Medical and Health Sciences
Research subject
urn:nbn:se:umu:diva-61766 (URN)10.1128/IAI.00435-12 (DOI)000309971600015 ()
Available from: 2012-11-27 Created: 2012-11-26 Last updated: 2018-06-08Bibliographically approved
Drobni, M., Hallberg, K., Öhman, U., Birve, A., Persson, K., Johansson, I. & Strömberg, N. (2006). Sequence analyses of fimbriae subunit FimA proteins on Actinomyces naeslundii genospecies 1 and 2 and Actinomyces odontolyticus with variant carbohydrate binding specificities.. BMC Microbiology, 43(6)
Open this publication in new window or tab >>Sequence analyses of fimbriae subunit FimA proteins on Actinomyces naeslundii genospecies 1 and 2 and Actinomyces odontolyticus with variant carbohydrate binding specificities.
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2006 (English)In: BMC Microbiology, ISSN 1471-2180, E-ISSN 1471-2180, Vol. 43, no 6Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Actinomyces naeslundii genospecies 1 and 2 express type-2 fimbriae (FimA subunit polymers) with variant Galbeta binding specificities and Actinomyces odontolyticus a sialic acid specificity to colonize different oral surfaces. However, the fimbrial nature of the sialic acid binding property and sequence information about FimA proteins from multiple strains are lacking. RESULTS: Here we have sequenced fimA genes from strains of A.naeslundii genospecies 1 (n = 4) and genospecies 2 (n = 4), both of which harboured variant Galbeta-dependent hemagglutination (HA) types, and from A.odontolyticus PK984 with a sialic acid-dependent HA pattern. Three unique subtypes of FimA proteins with 63.8-66.4% sequence identity were present in strains of A. naeslundii genospecies 1 and 2 and A. odontolyticus. The generally high FimA sequence identity (> 97.2%) within a genospecies revealed species specific sequences or segments that coincided with binding specificity. All three FimA protein variants contained a signal peptide, pilin motif, E box, proline-rich segment and an LPXTG sorting motif among other conserved segments for secretion, assembly and sorting of fimbrial proteins. The highly conserved pilin, E box and LPXTG motifs are present in fimbriae proteins from other Gram-positive bacteria. Moreover, only strains of genospecies 1 were agglutinated with type-2 fimbriae antisera derived from A. naeslundii genospecies 1 strain 12104, emphasizing that the overall folding of FimA may generate different functionalities. Western blot analyses with FimA antisera revealed monomers and oligomers of FimA in whole cell protein extracts and a purified recombinant FimA preparation, indicating a sortase-independent oligomerization of FimA. CONCLUSION: The genus Actinomyces involves a diversity of unique FimA proteins with conserved pilin, E box and LPXTG motifs, depending on subspecies and associated binding specificity. In addition, a sortase independent oligomerization of FimA subunit proteins in solution was indicated.

biofilm, adhesion, fimbriae
National Category
Dentistry Dentistry
urn:nbn:se:umu:diva-12937 (URN)10.1186/1471-2180-6-43 (DOI)16686953 (PubMedID)
Available from: 2007-11-01 Created: 2007-11-01 Last updated: 2018-06-09Bibliographically approved

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