Hemolytic activity and biofilm-formation among clinical isolates of group B streptococcus causing acute urinary tract infection and asymptomatic bacteriuria

Desai, Devika, Goh, Kelvin G. K., Sullivan, Matthew J. ORCID: https://orcid.org/0000-0003-2276-3132, Chattopadhyay, Debasish and Ulett, Glen C. (2021) Hemolytic activity and biofilm-formation among clinical isolates of group B streptococcus causing acute urinary tract infection and asymptomatic bacteriuria. International Journal of Medical Microbiology, 311 (6). ISSN 1438-4221

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Streptococcus agalactiae, also known as group B Streptococcus, is an aetiological agent of urinary tract infection (UTI) in adults, including cystitis, pyelonephritis and asymptomatic bacteriuria (ABU). Whereas ABU-causing S. agalactiae (ABSA) have been shown to grow and achieve higher culture denstity in human urine compared to uropathogenic S. agalactiae (UPSA) other phenotypic distinctions between S. agalactiae isolated from different forms of UTI are not known. Here, we define the hemolytic activities and biofilm-formation of a collection of clinical isolates of UPSA, ABSA and recurrent S. agalactiae bacteriuria (rSAB) strains to explore these phenotypes in the context of clinical history of isolates. A total of 61 UPSA, 184 ABSA, and 47 rSAB isolates were analyzed for relative hemolytic activity by spot assay on blood agar, which was validated using a erythrocyte lysis suspension assay. Biofilm formation was determined by microtiter plate assay with Lysogeny and Todd-Hewitt broths supplemented with 1% glucose to induce biofilm formation. We also used multiplex PCR to analyze isolates for the presence of genes encoding adhesive pili, which contribute to biofilm formation. Comparing the hemolytic activities of 292 isolates showed, surprisingly, that ABSA strains were significantly more likely to be highly hemolytic compared to other strains. In contrast, there were no differences between the relative abilities of strains from the different clinical history groups to form biofilms. Taken together, these findings demonstrate a propensity of S. agalactiae causing ABU to be highly hemolytic but no link between clinical history of UTI strains and ability to form biofilm.

Item Type: Article
Additional Information: Funding Information: This work was supported by Project Grants from the National Health and Medical Research Council (NHMRC) Australia ( APP1146820 to GCU; and APP1129273 to GCU).
Uncontrolled Keywords: biofilms,group b streptococcus,streptococcus agalactiae,urinary tract infection,microbiology,microbiology (medical),infectious diseases,sdg 3 - good health and well-being ,/dk/atira/pure/subjectarea/asjc/2400/2404
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Depositing User: LivePure Connector
Date Deposited: 15 Aug 2022 11:30
Last Modified: 24 Oct 2022 06:49
URI: https://ueaeprints.uea.ac.uk/id/eprint/87253
DOI: 10.1016/j.ijmm.2021.151520


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