Abstract

OBJECTIVES: Nowadays, due to the biofilm formation among of coagulase-negative staphylococci (CoNS), acquisition of antibiotic resistance and virulence genes could be noted. These organisms resembling other staphylococcus have mecA gene which encoded methicillin resistance but the diversity of it among CoNS is higher than other species. Based on increasing of antibiotic resistance in Staphylococcus haemolyticus, analyzing of phenotypic and genotypic biofilm formation, antibiotic resistance and genes involved in this process, SCCmec and ACME typing were placed as aims of current study. </p> <p> Methods. The number of 256 clinical CoNS isolates were collected which 49 isolates were identified as S. haemolyticus. For evaluation antibiotic resistance disk agar diffusion methods was applied, also biofilm assay carried out among methicillin resistance S. haemolyticus and SCCmec and ACME typing was performed.</p> <p> Results. The results of antibiotic susceptibility indicated that the highest resistance belongs to cotrimoxazole and erythromycin (86.6) and the frequency of blaA (96.5) and msrA (79.3) genes were much higher than others. Among MRSH isolates 58.6 have weak biofilm phenotype and 41.4 showed a moderate biofilm density. Also among of biofilm correlated genes, IS 256 (79.31) was the most frequent. The SCCmec typing of MRSH isolates indicated that the type V was dominant.</p> <p> Conclusions. Our finding indicated that correlation is between high rates of existence Is 256 gene and high prevalence of weak biofilm phenotype among MRSH isolates. Current study revealed that the multiple antibiotic resistances among clinical S. haemolyticus isolates are increasing and this is a warning to public health.