Biofilm formation capacity in common SCCmec types of coagulase-negative staphylococci isolated from hospitalized patients and health-care workers in northwest of Iran

The present study characterized the distribution; biofilm formation ability of common SCCmec (staphylococcal cassette chromosome mec) types of CoNS isolates from hospitalized patients (HP) and health-care workers (HCW) in northwest of Iran. Thirteen species of CoNS were identified by using of the conventional microbiological tests included S. epidermidis, S. haemolyticus, S. hominis S. warneri S. auricularis S. saprophyticus, S. lugdunensis, S. caprae, S. scheliferi, S. xylosus, S. capitis, S. simulans and S. cohnii. High prevalence of methicillin-resistant (MR-CoNS) isolates (76.2%) was observed. The prevalence of biofilm-producing isolates was higher in HP (93%) than HCW (82.5%). There was not a significant statistically difference between the presence of icaA, icaD and aap genes in these groups (p-value > 0.05). However, a significant statistically difference was observed in the presence of IS256 between two groups (p-value < 0.05). No significant association was observed between any SCCmec type and biofilm formation or the presence of biofilm related genes. The high prevalence of MR-CoNS and consequently, MDR isolates, as well as, their high ability to form slime or biofilm, is a common concern in our hospitals. Biofilm formation ability or the presence of biofilm related genes was not a SCCmec type trait.