Frequency of Reduced Vancomycin Susceptibility among Clinical Staphylococcus aureus Isolated in Ahvaz Iran
Abstract
Introduction: One of the most important agents in hospital-acquired infections isStaphylococcus aureus. Treatment of methicillin-resistant S. aureus (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 S. aureus (VISA) and
vancomycin- resistant S. aureus (VRSA) and also to determine the frequency of MRSA in
clinical specimens.
Methods: In this study, 195 S. aureus isolates were collected from the patients were examined.
All of the isolates were identified using standard biochemical tests. Susceptibility of S. aureus
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 mecA gene was performed
by PCR and finally, the results were compared.
Results: All of the isolates were susceptible to vancomycin (i.e. MIC range of vancomycin was
between 0.25-2 µg/ml). Out of 195 S. aureus isolates, 99 isolates (50.8%) were resistant to
methicillin, and mecA 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.
Conclusion: Our findings showed that vancomycin can still be used as a valuable drug for
treatment of S. aureus infections in our region. However, periodic evaluation of vancomycin
MIC of S. aureus isolates is critical for monitoring MRSA and preventing the spread of VISA or
VRSA among patients.
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| Files | ||
| Issue | Vol 4 No 1-2 (2015) | |
| Section | Original Articles | |
| Keywords | ||
| Methicillin-resistant Staphylocccus aureus mecA gene Polymerase ain reaction Vancomycin Staphylococcal infections | ||
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