Frequency of Class I Integron among Multidrug Resistant Pseudomonas aeruginosa Isolates from the Selected Hospitals in Qazvin and Tehran, Iran

Presence of class I integron in multidrug resistant (MDR) Pseudomonas aeruginosa isolates has created great concern in clinic. Given that various drug resistance genes are carried on integrons and can rapidly spread, identification of the integron-containing isolates provide useful information about the extent and development of drug resistance pattern. This study was performed aiming at evaluating the frequency of class I integron among MDR P. aeroginosa isolates collected from selected hospitals in Qazvin and Tehran. In this descriptive cross-sectional study, 100 clinical isolates of P. aeruginosa were collected using standard laboratory methods from selected hospitals in Qazvin and Tehran from June 2011 to June 2012. Antibiotic susceptibility pattern of all isolates against selected antibiotics was determined using standard disk agar diffusion method. Then, PCR assay was performed for detection of the presence of class I integron, and Chi-square test was used to determine the association between the presence of integron and MDR patterns. The significance level was considered to be less than 0.05. In total, 62 isolates showed MDR pattern, of which 36 isolates (58%) had class I integron, and a significant association was observed between the presence of class I integron and MDR pattern and also resistance to beta-lactam drugs, quinolones, and most aminoglycosides. Considering the high prevalence of class I integron among P. aeruginosa isolates and its association with different MDR patterns, use of appropriate infection control and treatment strategies in studied hospitals are necessary to prevent further spread of these organisms.