فهرست نشریات علمی دسترسی آزاد ایران

Background: Staphylococci are some of the most common causes of infections in birds. Worldwide, the dramatic increase in the prevalence of antimicrobial-resistant Staphylococcus aureus ( S. aureus ) is receiving widespread attention, due to multi-resistant strains, diminishing the usefulness of antibiotics in human medicine and, thereby limiting therapeutic options. Objectives: In this study, we characterized the distribution and antibiotic resistance patterns of methicillin resistant S. aureus (MRSA) strains, isolated from lying hen farms in Karaj, Iran. The pulsed field gel electrophoresis patterns and the staphylococcus cassette chromosome mec (SCC mec ) types were also determined. Results: Out of the 55 MRSA strains, all isolates were at least resistant to penicillin, 58% showed resistance to erythromycin and 55% were resistant to ciprofloxacin. On the other hand, all isolates showed susceptibility to vancomycin, quinuprostin-dalfopristin, linezolid, fusidic acid, nitrofurantoin and minocycline. The results of PFGE showed diverse pulsotypes, consisting of 13 common types and 18 single types, with seven common PFGE types, which were found among the MRSA strains, isolated from different farms, suggestive of an epidemiological link. Moreover, 67% of MRSA isolates shared SCC mec type III and showed type 3 ccr , indicating the hospital origin of the strains. Conclusions: The results of this study illustrated the persistence of resistant bacteria in the environment, and highlight the reservoir of resistance, associated with use of antibiotics, as feed additive in poultry production.