A Review: Evaluation of icaABCD operon expression In Staphylococcus aureus strains biofilm producers Download PDF

Background and aim: Staphylococcus aureus biofilm formation is key role in resistance to antibiotic. The possibility of biofilm formation on the surface and implicated devices such as catheters is one of the most important virulence factors in S. aureus. The aim of this study was assessment of biofilm formation and determination of the frequency of ica ADBC genes among these isolates. Materials and methods: In this study, 350 samples of blood, sputum, skin lesions, sneezing and urine were collected from hospitalized patients. A total 280 clinical isolates of S. aureus were obtained and identified from various infectious origins. Phenotypic biofilm formation was performed by using Congo red agar method. Prevalence of each of icaA, icaB, icaC and icaD genes were conducted by RT- PCR method. Results: Biofilm formation on CRA showed that 61 strains were biofilm producers, which 4 (6.6%), 43 (70.5%) and 14 (23%) of them were strong, mediate and weak biofilm producers, respectively. All strains has a strong biofilm formation that has icaD gene expression and 75% of these isolates were positive for icaA , icaC and icaB genes. The frequency of icaA/icaD genes in strains with mediate biofilm formation was 76.7%, however, these value for strains with weak biofilm formation was 28.6 %. Conclusion: in this study, more than half of S. aureus isolates showed biofilm formation among which the majority amplified icaA, icaC, icaD genes, and therefore it was shown a significant relationship between biofilm formation and icaADBC genes.