Qom University of Medical Sciences Journal

Background and Objectives: Pseudomonas aeruginosa is one of the multi-drug resistant pathogens and a cause of opportunistic neusocomial infections. Different methods have been used for investigating genetic diversity of P. aeruginosa. rep-PCR typing has been introduced as a rapid and low-cost method with high discriminatory power. The aim of this study was to investigate distribution, genotypic relatedness, and antibiotic resistance in clinical isolates of P. aeruginosa.

Methods: This cross-sectional study was conducted on 67 P. aeruginosa clinical isolates at Shahid Mohammadi Hospital, Bandar Abbas, Iran, between May 2012 and June 2013. Identification of strains and determination of antibiotic resistance pattern were conducted by conventional biochemical tests and Kirby-Bauer method, respectively. Genetic similarity was investigated by rep-PCR. The correlation between molecular types and antimicrobial resistance patterns was determined by Pearson's chi-square test. p≤0.05 was considered to be the level of significance.

Results: rep-PCR results exhibited seven genotypic clusters with 76% similarity. Genotypes A and C were the most prevalent types with 16 (23.8%) frequency. ICU had the most distribution and diversity of rep-PCR types. The majority of isolates were obtained from sputum (29.8%). Most isolates were resistant to cotrimoxazole (80.6%) and susceptible to ciprofloxacin (85.1%), as the most effective antibiotic.

Conclusion: The result of this study showed that P. aeruginosa rep-PCR types A and C were the predominant strains in the studied hospital. Because drug resistance is considered a serious challenge ahead for treatment of nosocomial infections, it is necessary to implement the guidelines of infection control to reduce P. aeruginosa infections.