Molecular Identification of icaA, icaB, icaC and icaD Genes in Staphylococcus aureus Clinical Isolates Resistant to Methicillin

Background & Objectives: Staphylococcus aureus is one of the most common nosocomial pathogens with high mortality rates. The Biofilm-dependent methicillin-resistant S. aureus remains a major clinical concern in this group of patients. The aim of this study was to investigate the icaABCD forming biofilm genes in methicillin resistant isolates of S. aureus. Materials and Methods: In study was performed on 238 S. aureus isolates from various clinical specimens obtained from patients referring to Shohada hospital, Mahmudabad in 1396. Susceptibility test to methicillin was performed by disk diffusion agar according to Clinical and Laboratory Standards Institute guidelines. All Methicillin-resistant S. aureus isolates were examined for phenotype biofilm formation and determination the icaABCD genes by using Congo red agar and PCR method. Results: The ability for biofilm formation in 33 (38%) methicillin-resistant isolates of S. aureus was showed strong 8 isolates (24.24%) as strong, 19 isolates (57. 57%) as average and 6 isolates (18.19 %) as weak. The prevalence of icaA, icaB, icaC, and icaB were 8%, 9%, 10% and 20% respectively. Conclusion: Our results indicated that the isolates of methicillin-resistant S. aureus were able to form biofilms and all four icaABCD genes were identified in these isolates.