RESUMO
@#Introduction: Biofilm is one of the important virulence factors that is responsible for the severity and progression of the Streptococcus pyogenes diseases. M-protein is involved in the irreversible attachment of S. pyogenes to surfaces during biofilm development. This study aims to determine the propensity of S. pyogenes to form biofilms and the molecular epidemiology of S. pyogenes isolates by emm typing. Methods: We screened 45 S. pyogenes isolates for the biofilm formation by Congo red agar (CRA) and quantified the biofilms by crystal violet microtiter-plate methods (CVMtP). The emm typing of all isolates was performed by conventional PCR with established primers according to the CDC protocol. Results: Majorities of S. pyogenes were isolated from non-invasive, 27 (60.0%) than invasive sources, 18 (40.0%). Regardless of invasiveness, 40 (88.9%) S. pyogenes isolates formed black colonies on CRA, while 43 (95.6%) of the isolates demonstrated various degrees of biofilm formation by CVMtP method. A total of 30 different emm types and subtypes were identified. No new emm types/subtypes were detected. The predominant emm types/subtypes were emm1, emm63, emm18.21, emm91, and emm97.4 which each gene accounted for 7.0%. All emm types/subtypes of S. pyogenes produced biofilms by CVMtP method except emm17.2 and emm57 which were isolated from non-invasive sources. Conclusions: Biofilm-producing S. pyogenes strains of various sources are genetically diverse and biofilm phenotypes are inherent to individual characteristic rather than specific emm type. Nonetheless, higher propensity of GAS to form biofilms warrants better management strategies to avoid treatment failures in the future.
