Trends of Antibiotic Resistance in Staphylococcus aureus Isolates Obtained from Clinical Specimens

Background: Staphylococcus aureus is one of the most common causes of nosocomial infections that cause a broad spectrum of diseases. Increasing antibiotic resistance among S. aureus isolates is a serious concern in the treatment and control of staphylococcal infections. The knowledge of S. aureus prevalence and the current antimicrobial resistance profile is necessary in selection of appropriate treatment of related infections. Aim and Objectives: The present study aimed to determine the frequency and antibiotic resistance profile of S. aureus isolates in clinical isolates. Material and Methods: This cross-sectional study was performed within six months from October 2012 on 345 S. aureus isolates collected from different clinical specimens from two major hospitals in Shiraz, Southwest Iran. S. aureus isolates were identified using standard microbiological procedure. Antimicrobial resistance patterns were determined using disk diffusion method in accordance with Clinical & Laboratory Standards Institute (CLSI) recommendation. Results: Overall, the most prevalent clinical source of Methicillin-Resistant Staphylococcus aureus (MRSA) isolation belonged to respiratory specimens. MRSA isolates significantly showed higher antibiotic resistance rates compared to Methicillin-Sensitive Staphylococcus aureus (MSSA) isolates (P <0.001). Despite the differences in relative frequency of MRSA isolates' antibiotic resistance between two hospitals, no statistical differences were estimated. The rate of MSSA isolates' antibiotic resistance between the studied Trends of Antibiotic Resistance in Staphylococcus aureus Isolates Obtained from Clinical Specimens 1 1 1 1 Hadi Sedigh Ebrahim-Saraie , Hamid Heidari , Reza Khashei , Fatemeh Edalati , 1 1,2* Yalda Malekzadegan , Mohammad Motamedifar 1 Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, 2 Shiraz, Iran, Shiraz HIV/AIDS Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran hospitals are close and only significant differences were seen toward co-trimoxazole (P <0.05). Moreover, molecular characteristics were associated with specific isolation sites and antibiotic resistance trends. Conclusion: Demonstrated association of some clinical sources with higher rates of MRSA isolation and unique antibiotics trends and also association with their molecular background can help healthcare facilities manage efficient infection control policies.