Methicillin Resistant Staphylococci: Prevalence and susceptibility patterns in a burn center in Ahvaz from 2013-2014.

Background And Objectives: Methicillin resistance Staphylococcus aureus (MRSA) and coagulase negative staphylococci (MRCoNS) have recognized as the major cause of nosocomial infections that threat the burn patient's life. The aims of this study were to determine the frequency of MRSA and MRCoNS and their antibiotic resistance patterns among burn patients in a burn center in Ahvaz, Iran.

Material And Methods: A total of 340 clinical specimens: (80%) wound and (20%) blood were obtained from patients in Taleghani burn hospital during February 2013-2014. Staphylococci species identification and antibiogram were performed by standard procedures using disk diffusion method. The Methicillin resistance strains were detected by Etest and PCR using mecA specific primers.

Results: Out of 30.2% (103) isolates that were recognized as staphylococci, 82 % (84) and 18% (19) were identified as S. aureus and coagulase negative staphylococci (CoNS) respectively. Resistance to methicillin was detected in 60% and 63% of the S. aureus and CoNS isolates respectively. Seven different antimicrobial resistance patterns observed among methicillin resistant staphylococci. The MRSA and MRCoNS strains showed closed resistance phenotypes. All the methicillin resistant isolates showed a high rate resistance to the other studied antibiotics in comparison to methicilin sensitive isolates. Vancomycin and imipenem showed the greatest effect against methicillin resistant isolates. During 8 years in the studied burn hospital, no significant changes in the methicillin resistance staphylococci frequency were detected.

Conclusion: The presence of multi resistant MRSA and MRCoNS strains is cause of concern in burn hospitals. Vancomycin remains as a drug of choice for methicillin resistance staphylococci infections.