Non-clonal Dissemination of Extended-Spectrum Beta-Lactamase-Producing Pseudomonas aeruginosa Strains of Clinical Origin

Monitoring the emergence and transmission of Pseudomonas aeruginosa strains is important for infection control worldwide. The aim of this study is to determine the genetic diversity of 47 extended-spectrum beta-lactamase-producing P. aeruginosa strains of clinical origin by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and also to ascertain the presence of class 1 integrons among them. ERIC sequences are 127 bp imperfect palindromes that occur in multiple copies in the genomes of enteric bacteria. The ERIC-PCR profile generated showed polymorphism in the studied strains. Based on the ERIC-PCR profile, P. aeruginosa strains were grouped into 23 types. The major genotype, designated as type L1, accounted for 10.6% (5/47) of samples. Class 1 integrons were detected in 8 of the 47 clinical isolates. Further, the integron-carrying isolates were found to display higher minimum inhibitory concentration against tested antibiotics. Optimization of antimicrobial use and control of infection is recommended to prevent the increase in the population of drug-resistant organisms.