Frequency of mecA Gene in the Clinical Isolates of Staphylococcus epidermidis in Isfahan, Iran

Staphylococcus epidermidis is an important agent for nosocomial infections in infants and people with permanent prostheses. Its increased resistance to antibiotics has created a serious challenge for healthcare system. This study was conducted to determine the pattern of antibiotic-resistance of S. epidermidis isolates from clinical samples.
During nine months, 251 clinical samples isolated from strains of S. epidermidis were examined. Following identification of isolates, their antibiotic sensitivity was determined using disc diffusion method. Resistance to vancomycin was assessed using agar screening method, and its MIC values were measured using episilometry (E-test). Methicillin-resistant gene (mecA) was traced using PCR.
A total of 120 S. epidermidis strains were isolated from the 251 clinical samples, mostly associated with urine samples. In this study, 95 isolates (79%) were found resistant to cefoxitin, 66 (55%) to vancomycin, and 94 (78.33%) to multiple drugs. In molecular assessment, 37 isolates (54.41%) contained mecA gene, of which, 32 isolates showed resistance to vancomycin.
Increased resistance to methicillin and vancomycin in S. epidermidis isolates represents a serious warning to the healthcare system. Thus, careful and appropriate choice of treatment is imperative for reducing medication resistance.