Genetic cassettes profiling of class I integron and antimicrobial susceptibility profiles among Pseudomonas aeruginosa isolates collected from hospitalized patients in Babol, north of Iran

Pseudomonas aeruginosa (P. aeruginosa) is a nosocomial opportunistic bacterium especially in infection wards and among patients with burns. In this study, we dealt with molecular investigation of gene cassettes of Class I integron and its relationship with multiple drug resistances in clinical samples of P. aeruginosa isolated from Babol hospitals (north of Iran).

The aims of this study were detecting the frequency of int1 and gene cassettes in clinically isolates of P. aeruginosa.

In this study, from 75 clinical samples, 30 strains were identified via specific biochemical methods. After determining antibiotic susceptibility using disk diffusion and agar dilution, the frequency of Class I integron (intI) gene and its gene cassettes were determined via polymerase chain reaction (PCR) method.

The highest resistance rate was related to cefotaxime, ampicillin, and nitrofurantoin by disk diffusion and agar dilution. The molecular analysis showed that 60% of isolates had the intI genes. The frequency of aadB, dfrA1 and bla-OXA30 genes were 61%, 66% and 33%, respectively.

The high resistance of Pseudomonas isolates is due to the presence of intI and its gene cassettes. Thus, considering their high resistance to the antibiotics of cefotaxime, gentamicin, ampicillin, and imipenem in hospitals, selecting suitable drugs or generally changing the treatment course of patients is possible to prevent the spread of resistance developing genes and development of nosocomial infections. Keywords: Pseudomonas aeruginosa, Class 1 integron, Gene Cassette, Antibiotic resistance.