title: Streptococcus agalactiae infection in zebrafish larvae.
abstract: Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β (il1b) and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis.
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego CA 92182, USA.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego CA 92182, USA.
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Hancock
authors.affiliation: Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla CA 92093, USA.
authors.forename: Natasha
authors.initials: N
authors.lastname: Del Cid
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego CA 92182, USA.
authors.forename: Andres
authors.initials: A
authors.lastname: Bermudez
authors.affiliation: Department of Cellular and Molecular Medicine, University of California at San Diego, 9500 Gilman Drive, La Jolla CA 92093, USA. Electronic address: dtraver@ucsd.edu.
authors.forename: David
authors.initials: D
authors.lastname: Traver
authors.affiliation: Department of Biology and Center for Microbial Sciences, San Diego State University, 5500 Campanile Drive, San Diego CA 92182, USA; Department of Pediatrics, University of California San Diego, School of Medicine, 9500 Gilman Drive, La Jolla CA 92093, USA. Electronic address: kdoran@mail.sdsu.edu.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Doran
mesh_terms: D000818:Animals; D001921:Brain / Q000382:microbiology / Q000473:pathology; D004195:Disease Models, Animal; D054884:Host-Pathogen Interactions; D053583:Interleukin-1beta / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D007814:Larva / Q000382:microbiology*; D013290:Streptococcal Infections / Q000382:microbiology* / Q000473:pathology*; D013292:Streptococcus agalactiae / Q000254:growth & development* / Q000472:pathogenicity; D016019:Survival Analysis; D014774:Virulence; D037521:Virulence Factors / Q000032:analysis / Q000235:genetics; D015027:Zebrafish / Q000382:microbiology*
chemical_list: D053583:Interleukin-1beta; D016209:Interleukin-8; D037521:Virulence Factors
keywords: Group B Streptococcus; Pathogenesis; Zebrafish larvae