Analysis of Class 1 Integrons and Antibiotic Resistance Genes in Pseudomonas aeruginosa Strains from Benin City, Nigeria

Abstract

The presence of integrons and antibiotic resistance genes in the genome of Pseudomonas aeruginosa pose a serious problem in the treatment and control of infections caused by this pathogen in hospitals. This study was carried to analyse the presence of class 1 integrons and some antibiotic resistance genes on selected clinical and environmental strains of Pseudomonas aeruginosa. A total of 120 strains were employed for this study.
The strains were confirmed using molecular method and species-specific primers targeting the 16S ribosomal ribonucleic acid (rRNA). Polymerase chain reaction (PCR) was used to detect the presence of class 1 integrons and resistance genes using appropriate primers and conditions. The strains were analysed for the presence of the following antibiotic resistance genes - aadA, blaPSE, blaAMPC, blaIMP and tetC encoding  aminoglycosides, betalactamases, metallo-beta-lactamases (MBL) and tetracylines resistance respectively. On screening the isolates for the presence of class 1 integrons, 50/60 (83.3 %) clinical isolates and 46/60 (76.7 %) environmental isolates showed positive results (P > 0.05). In both clinical and environmental isolates, the highest occurring resistance genes were blaAMPC and tetC (encoding beta-lactamases and tetracylines respectively), while the least was observed in blaIMP (encoding metallo-beta-lactamases). In comparison, there was high significance difference (at P<0.01 significance level) in the resistance gene blaPSE between the clinical and environmental strains. The high prevalence of these resistance genes is a great threat in the treatment of Pseudomonas infections.

Keywords: Pseudomonas aeruginosa, Resistance genes, Integrons, Beta-lactamases.