Biofilm formation of beta ‐hemolytic group G Streptococcus dysgalactiae subspecies equisimilis isolates and its association with emm polymorphism

Biofilm formation has been well known as a determinant of bacterial virulence. Group G Streptococcus dysgalactiae subspecies equisimilis (SDSE), a relevant pathogen with increasing medical importance, was evaluated for the biofilm‐forming potential. Microtiter plate assay was used to assess the most feasible medium for group G SDSE to form a biofilm. Among 246 SDSE isolates examined, 46.7%, 43.5%, 33.3%, and 26.4% of isolates showed moderate or strong biofilm‐forming abilities using tryptic soy broth (TSB), brain heart infusion broth (BHI), Todd‐Hewitt broth (THB), and C medium with 30 mM glucose (CMG), respectively. The addition of glucose significantly increased the biofilm‐forming ability of group G SDSE. FCT (fibronectin–collagen–T‐antigen) typing of SDSE was first undertaken and 11 FCT types were found. Positive associations of stG10.0 or negative associations of stG245.0, stG840.0, and stG6.1 with biofilm‐forming ability of SDSE were, respectively, found. This was the first investigation demonstrating biofilm‐forming potential in clinical group G SDSE isolates; also, some significant associations of biofilm‐forming ability with certain emm types were presented.
Source: APMIS - Category: Research Authors: Tags: Original Article Source Type: research