Qom University of Medical Sciences Journal

Background and Objectives: One of the most common problems in hospitals is infections caused by Pseudomonas aeruginosa that is an opportunistic pathogen for humans. Five important enzymes, including exotoxin A, Y, T, U, S are major virulence factors in this bacterium. The purpose of this study was to determine the frequency of these enzymes in the samples isolated from hospitals of Qom city and to determine their antibiogram pattern against third-generation cephalosporins using CLSI standards.

Methods: In this cross-sectional analytical study, 120 strains of P. aeruginosa isolated from various clinical specimens from hospitals of Qom city, were examined. At first, bacteria were identified using biochemical tests, and then their antibiogram pattern against third-generation cephalosporins was obtained according to CLSI standards. After genome extraction (extraction kit of Sinaclon Co.), primers design and evaluation were performed through NCBI website, and PCR reaction was conducted to evaluate each gene. After electrophoresis, the bands’ results obtained from PCR reaction, was observed in gel doc system.

Results: The frequency of the isolates in the samples of skin, blood, lung, and urine was, respectively, 63.2, 16.1, 16.1/, and 4.1%. The frequency of exotoxins A, T, U, S, and exoenzyme Y were respectively obtained to be 100, 37.9, 26.4, 39.1, and 29.9%.

Conclusion: According to the results of this study, drug resistance and presence of virulence factors, such as exotoxins can be a serious warning to treatment centers in terms of control of disease caused by this bacterium.