Frequency of Methicillin Resistance, fnbA and fnbB Genes in Clinical Isolates of Staphylococcus aureus

Staphylococcus aureus is an opportunistic pathogen, which particularly its methicillin resistant strains, is responsible for a wide range of hospital and community acquired infections. Adhesion ability is one of the important virulence factors of this bacterium. In this study, the resistance to methicillin and the frequency of fnbA and fnbB adhesion genes in clinical isolates of S. aureus were investigated.
Isolates of S. aureus were collected from clinical samples of patients referred to Rasht medical diagnostic laboratories. Resistance of isolates to methicillin was investigated by disk diffusion method and determination of presence of mecA gene. Frequency of fnbA and fnbB adhesion genes in methicillin sensitive and methicillin resistant strains was determined using specific primers of these genes in PCR reaction and was compared using chi-square test.
Out of 90 isolates, 37 isolates (41%) were resistant to methicillin and mecA positive. Also, in the PCR reaction, fnbA and fnbB genes were identified in 59 (65.5%) and 37 (43.3%) isolates, respectively. The prevalence of fnb genes in Staphylococcus aureus methicillin-resistant strains was significantly higher than that of methicillin-susceptible strains (P The results of this study indicate high prevalence of methicillin-resistant strains in clinical isolates of S. aureus in Rasht and the frequency of fnb gene in these isolates.