Biofilm forming ability and agr- specific group of methicillinresistantStaphylococcus aureus in Northern Iran

Background and Aim : Staphylococcus aureus is one of the most common causing agent ofnosocomial infection, worldwide. The methicillin-resistant and biofilm-dependent infections ofthis bacterium has become a clinical concern in patients. This research aimed to identify biofilmforming ability and agr- specific group of clinical isolates of methicillin-resistant S. aureus(MRSA) in northern Iran.Methods : During ۲۰۲۱, a total of ۲۰۰ clinical isolates were identified as S. aureus by biochemicaltests. The disk diffusion method was used to examine the antibiotic resistance of isolates and themicroplate method was applied to investigate the biofilm production capability. In addition, thePCR method was used to determine the frequency of biofilm associated genes and agr typing ofMRSA isolates. P£۰.۰۵ was considered significant.Results : Overall, ۱۲۵ (۶۲.۵%) out of ۲۰۰ isolates were methicillin-resistant and ۷۵% weremultiple antibiotic-resistant. Vancomycin was the most efficient antibiotic against the isolates andhighest resistant rate was against penicillin. Biofilm forming ability was detected in ۹۹ (۷۹.۲%)methicillin-resistant isolates in which icaA and icaD were found in ۸۵% and ۷۸% of biofilmproducingisolates, respectively. Type ۱ of the agr gene was the most common type amongmethicillin-resistant isolates. The frequency of biofilm associated genes showed significantassociation with MDR phenotype and presence of agr locus (P£۰.۰۵).Conclusion : Present results indicate high frequency of biofilm and antibacterial resistance inmethicillin-resistant S. aureus isolates in Guilan Province, northern Iran. Present data suggestsreliable and rapid identification of biofilm forming MRSA strains to prevent the spread of thesebacteria.

کلیدواژه ها:

Staphylococcus aureus ، methicillin resistance ، biofilm ، agr typing