Tehran University Medical Journal

Background: Staphylococcus aureus is one the most common pathogens causing community-acquired infections and a major concern for public health, and the other hands antibiotic resistance is also of great concern for public health authorities also Staphylococcus aureus produce a lot of virulence factors such as variety of exoproteins included toxic shock syndrome and exfoliative toxin which causes colonization and different infections in their host. The aims of current study were to evaluate the prevalence of Toxic shock syndrome toxin 1 (TSST-1) and ETs genes in isolated S. aureus strains using polymerase chain reaction (PCR) assay. Methods: This cross-sectional study was performed on 100 methicillin-resistant staphylococcal aureus (MRSA) and 100 methicillin-sensitive staphylococcal aureus (MSSA) isolated from clinical specimens of inpatients, outpatients hospitals and nasal carriers in Hamadan University from October 2013 to August 2014. Identified species by biochemical methods were confirmed by the PCR method. Antibiotic resistance was performance by disk diffusion and the presence of TSST-1 and ETs genes was investigated using PCR. Results: Of the 100 isolates MRSA examined, the most frequent resistance was observed to ciprofloxacin (95%), followed by tetracycline (91%), erythromycin (92%), Gentamicin (90%), Rifampin (85%), trimethoprim-sulfamethoxazole (85%), clindamycin (80%) and cefoxitin (100%). Of the 100 isolates MSSA examined, the most frequent resistance was observed to erythromycin (68%), ciprofloxacin (66%), followed by tetracycline (52%), gentamicin (25%), clindamycin (46%), rifampin (45%), trimethoprim-sulfamethoxazole (66%) and cefoxitin (0%). Prevalence of TSST-1 and ETs genes were determined 13% (n=26) isolates, totally. Also the prevalence of TSST-1 was 11% (n=22) and ETs genes was 2% (n=4) isolates and none of the investigated isolates carried eta gene. Conclusion: The increasingly prevalence of MRSA and emerging its antibiotic resistance in clinical isolates can be considered a serious problem for public health. Detection of the high rate prevalence of TSST genes in current study is considered as a serious problem and existing and circle of these strains in according to colonization in community especially old people and immunocompromised patients is very serious.