Background and Aims: The indiscriminate use of antibiotics can lead to antibiotic resistance in the treatment of infections caused by bacteria such as Pseudomonas aeruginosa. The presence of integrons in Pseudomonas is clearly associated with multidrug resistances. Therefore, this study aimed at tracking class I, II and III integrons of antibiotic-resistant isolates of Pseudomonas aeruginosa that were isolated from nosocomial infection.

Materials and Methods: In this study, 51 isolates of Pseudomonas aeruginosa were collected from different wards of Imam Khomeini hospital of Ahvaz since October of 2014 until March of 2015. After identification test and antibigram, coding genes of antibiotic resistance and class I, II and III integrons were detected by polymerase chain reaction (PCR) method.

Results: Tetracycline revealed the most resistance with 84% frequency in discreted isolates. In the encoding antibiotic resistance genes with a frequency of 94% was the most common blaTEM. Class I integron had 92% prevalence, class II Integron showed 52% prevalence and class III Integron demonstrated 17% prevalence.

Conclusions: In Pseudomonas aeruginosa, class I integron was more prevalent than other integrons and the integrase gene was probably one of the causes of multiple antibiotic resistance in this bacteria. Moreover, frequency of integron III  was  reported 17%.