Khalil Maleki Chollu - Sarab Faculty of Medical Sciences, Sarab, Iran
Yousef Lotfi Hadi Biglu - Islamic Azad University, Sarab branch, Sarab, Iran
Ali Sadighi - Medical Laboratory Sciences, Sarab Faculty of medical sciences, Sarab, Iran.
Leili Hasheminejad - Sarab Faculty of Medical Sciences, Sarab, Iran

The pathogenic potential and commensal nature of Staphylococcus aureus allow for easy transmission especially the nasal cavity is the main colonization site of Staphylococcus aureus in the human body. The resistance of Staphylococcus aureus to commonly used antibiotics is linked to their ability to acquire and disseminate antimicrobial-resistant determinants in nature. This study aimed to determine the molecular characteristics and antibiotic susceptibility pattern of S. aureus isolates obtained from the nasal carriage of health care workers (HCWs). Our study was performed between January 2017 and March 2017 at two privatehospitals in Tabriz, Iran. Nasal samples were collected from the nasal cavity of HCWs. Standard microbiological methods were used for identification of S. aureus isolates. Antibiotic susceptibility pattern was determined by the disc diffusion method. Determination of virulence genes was performed by the PCR method. From a total of 150 nasal swab samples of HCWs, 34 S. aureus strains (22.6%) including 13 (38.2%) MRSA were isolated. In MRSA isolates the highest sensitivity was for vancomycin and rifampicin, with 94%. Overall, 23.5% (8/34) and 94.1% (32/34) of S. aureus isolates were positive for pvl and hla genes, respectively. This study also shows that nasal isolates of S. aureus from healthy ruminants might be a potential reservoir of antimicrobial-resistance. The most common risk factors for S. aureus carriage in risk groups were being male, age ≤ 30 years, and nasal cavity cleaning habits. The results of the present study indicate that S. aureus nasal carriage with potential virulence ability still remains a significant healthcare problem, especially in hospital environments.

Staphylococcus aureus, Antibiotic resistance, MRSA, Nasal carriage