Find in Library

<p><strong><em>Introduction:   </em></strong>One   of   the   most   important   agents   in   hospital-acquired   infections   is <em>Staphylococcus aureus. </em>Treatment of methicillin-resistant <em>S. aureus </em>(MRSA) infections with decreased susceptibility to vancomycin has recently been more difficult. The aim of this study was to evaluate the possible presence of vancomycin intermediate <em>S. aureus </em>(VISA) and vancomycin- resistant <em>S. aureus </em>(VRSA) and also to determine the frequency of MRSA in clinical specimens.</p><p><strong><em>M</em></strong><strong><em>e</em></strong><strong><em>thods: </em></strong>In this study, 195 <em>S. aureus </em>isolates were collected from the patients were examined. All of the isolates were identified using standard biochemical tests.  Susceptibility of <em>S. aureus </em>isolates against 10 antibiotics was detected by disk diffusion method and was followed by E-test and vancomycin screen agar methods. Minimum inhibitory concentration (MIC) of vancomycin was determined according to the CLSI guidelines.  Also, detection of <em>mecA </em>gene was performed by PCR and finally, the results were compared.</p><p><strong><em>Results: </em></strong>All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was between 0.25-2 µg/ml). Out of 195 <em>S. aureus </em>isolates, 99 isolates (50.8%) were resistant to methicillin, and <em>mecA </em>gene was detected in 96 isolates. These results also showed that the highest and lowest resistance rate of isolates was to penicillin (96.9%) and chloramphenicol (0%), respectively.</p><p><strong><em>Conclusion: </em></strong>Our findings showed that vancomycin can still be used as a valuable drug for treatment of <em>S. aureus </em>infections in our region. However, periodic evaluation of vancomycin MIC of <em>S. aureus </em>isolates is critical for monitoring MRSA and preventing the spread of VISA or VRSA among patients.</p>