title: Group B streptococcal serine-rich repeat proteins promote interaction with fibrinogen and vaginal colonization.
abstract: Group B streptococcus (GBS) can cause severe disease in susceptible hosts, including newborns, pregnant women, and the elderly. GBS serine-rich repeat (Srr) surface glycoproteins are important adhesins/invasins in multiple host tissues, including the vagina. However, exact molecular mechanisms contributing to their importance in colonization are unknown. We have recently determined that Srr proteins contain a fibrinogen-binding region (BR) and hypothesize that Srr-mediated fibrinogen binding may contribute to GBS cervicovaginal colonization. In this study, we observed that fibrinogen enhanced wild-type GBS attachment to cervical and vaginal epithelium, and that this was dependent on Srr1. Moreover, purified Srr1-BR peptide bound directly to host cells, and peptide administration in vivo reduced GBS recovery from the vaginal tract. Furthermore, a GBS mutant strain lacking only the Srr1 "latching" domain exhibited decreased adherence in vitro and decreased persistence in a mouse model of GBS vaginal colonization, suggesting the importance of Srr-fibrinogen interactions in the female reproductive tract.
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University.
authors.forename: Nai-Yu
authors.initials: NY
authors.lastname: Wang
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Patras
authors.affiliation: Division of Infectious Diseases, Veteran Affairs Medical Center and the University of California San Francisco, California Radiation Biotechnology Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Republic of Korea.
authors.forename: Ho Seong
authors.initials: HS
authors.lastname: Seo
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University.
authors.forename: Courtney K
authors.initials: CK
authors.lastname: Cavaco
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University.
authors.forename: Berenice
authors.initials: B
authors.lastname: Rösler
authors.affiliation: Department of Immunology and Microbiology, School of Medicine, Wayne State University, Detroit, Michigan.
authors.forename: Melody N
authors.initials: MN
authors.lastname: Neely
authors.affiliation: Division of Infectious Diseases, Veteran Affairs Medical Center and the University of California San Francisco, California.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Sullam
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University Department of Pediatrics, University of California San Diego School of Medicine, La Jolla.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Doran
mesh_terms: D018829:Adhesins, Bacterial / Q000502:physiology*; D000818:Animals; D001422:Bacterial Adhesion; D002460:Cell Line; D004195:Disease Models, Animal; D004848:Epithelium / Q000382:microbiology; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000502:physiology*; D051379:Mice; D012694:Serine; D013290:Streptococcal Infections / Q000382:microbiology*; D013292:Streptococcus agalactiae / Q000472:pathogenicity* / Q000502:physiology; D014621:Vagina / Q000382:microbiology*; D014623:Vaginal Diseases / Q000382:microbiology
chemical_list: D018829:Adhesins, Bacterial; D008562:Membrane Glycoproteins; D012694:Serine; D005340:Fibrinogen
keywords: GBS; Srr1; fibrinogen; vaginal colonization