Staphylococcal Cassette Chromosome mec (SCCmec) Typing of Staphylococcus epidermidis Strains Isolated fromUrinary Tract Infections in Chaharmahal and Bakhtiari Province, Iran

Staphylococcus epidermidis is the most important species of coagulase-negative Staphylococci and causes various nosocomial infections, such as urinary tract infections. Therefore, attention to the resistance pattern of this organism, especially resistance to methicilin, is of particular importance. The aim of this study was to determine the antibiotic resistance pattern of Staphylococcus epidermidis strains isolated from urine specimens in hospitals of Chaharmahal and Bakhtiari province, Iran.

This study was conducted on 50 urine samples (in volumes of 20 ml) obtained from patients with urinary tract infections from ChaharMahal and Bakhtiari hospitals in sterile containers. The samples were tested by culture and molecular methods. After the molecular confirmation of the isolated strains, a simple disk diffusion test was used to determine the antibiotic resistance pattern. In addition, polymerase chain reaction (PCR) method was employed to determine the Staphylococcal cassette chromosome mec (SCCmec) types.

Out of the 50 samples, 23 specimens (46%) were infected with Staphylococcus epidermidis, which had 16srDNA gene in the PCR test. Antimicrobial resistance pattern was determined according to the Clinical and Laboratory Standards Institute. All isolates had multi-antibiotic resistance. In this regard, the isolates showed the highest resistance to penicillin (95.65%) and tetracycline (91.30%) and the lowest resistance to nitrofurantoin (34.78%). Furthermore, 73.91% of the isolates were the carriers of mecA gene. The SCCmec III (47.05%) was the most common type of chromosomal cassette mecA gene in methicillin-resistant isolates.

The prevalence of resistance to a wide range of antibiotics in the first- and second-line treatment among strains of Staphylococcus epidermidis shows the distribution and dissemination of these strains in the hospitals of ChaharMahal and Bakhtiari province. Consequently, it is necessary to select the medication based on the antibiogram result.