Frequency Evaluation of icaA Gene in Multidrug Resistant Staphylococcus aureus Strains Isolated from Clinical Specimens in Rasht

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections.  The polysaccharide adhesion mechanism encoded by the ica operon generates a direct role in biofilm formation and infection of the bacteria. The aim of this study was to evaluate the frequency of icaA gene in Staphylococcus aureus isolates isolated from clinical specimens of patients admitted to some clinical centers of Rasht.

This descriptive, cross-sectional study was performed on 100 Staphylococcus aureus isolates from some clinical centers of Rasht in 2019 and confirmatory tests were performed to identify the bacteria. icaA gene identification and its frequency were investigated using molecular methods . The antibiotic resistance pattern against 10 antibiotics and biofilm-forming ability of the isolates were determined using the disk diffusion method and Congo red method respectively.

In the present study, among the 100 studied isolates, the highest drug resistance was related to penicillin, and the lowest antibiotic resistance was belonged to ciprofloxacin. 81 isolates (81%) were resistant to methicillin and 37 isolates (37%) had multiple resistance. Of 37 isolates with multiple resistances, 32 isolates (86.48%) had icaA gene and 24 isolates (64.9%) ،had the ability to produce strong biofilms.

According to the findings of this study, the prevalence of Staphylococcus aureus isolates carrying icaA gene with strong biofilm forming ability and resistance to methicillin, were high. This necessitates the need for serious management of antibiotic administration.