Study of nasal carriage Methicillin resistant Staphylococcus aureus in hemodialysis patients in Kermanshah

Background: Methicillin resistant Staphylococcus aureus (MRSA) nasal carriers play role in development of nosocomial infections and may increase treatment costs and mortality rate. These isolates, in addition to beta lactamase, is resistant to other drugs. Carrier frequency and spectrum awareness of drug sensitivity in these isolates will be useful in choosing more effective methods of control and treatment.

Methods: Nasal anterior parts samples collected from 160 hemodialysis patients in Imam Reza hospital. After diagnosis of Staphylococcus aureus, their sensitivity to 11 different antibiotics was determined using Kirby-bauer method and oxacillin strips. MRSA isolates, MIC was determined by microdilution method.

Results: Twenty-eight percent of hemodialysis patients were Staphylococcus aureus nasal carriage and 31% of the isolates were MRSA type. Penicillin was the most resistance (96%) and vancomycin was the lowest resistance (0%) antibiotics. Frequency of resistance to azithromycin, ciprofloxacin, cloxacillin, doxycycline, gentamicin and co-trimoxazole was 20-29% and chloramphenicol, clindamycin and rifampin was less than 10%. Most of MRSA isolates were resistance than MSSA isolates. 86% of MRSA isolates were identified as MDR. Oxacillin MIC for all MRSA isolates was more than 64 micg/ml.

Conclusion: Antibiotic resistance patterns of isolated MRSA and MSSA was intirely different from each other so unlike MRSA, MSSA isolates were sensitive to the most antibiotics. Penicillin was totally ineffective and vancomycin was recognized as the most effective antibiotic in this study.