Detection of bla TEM β-lactamase genes from clinical isolates of Pseudomonas aeruginosa in Chennai, India

Abstract

ABSTRACT Existence of metallo-β-lactamases (MBLs) genes plays an important role in spreading β-lactam antibiotic resistance in the producing strains of these enzymes. The resistance of gram-negetive bacteria, such as Pseudomonas aeruginosa, to different antimicrobial agent, especially β-lactam and carbapenem, has been reported with increasing frequency worldwide. The aim of this study was to investigate the prevalence of bla TEM gene encoding metallo-β-lactamases among a collection of Pseudomonas aeruginosa strains isolated from patients at different hospitals and health centers in Chennai, India through duplex PCR method. Susceptibility of 65 P. aeruginosa to 4 different antibiotics was determined using disc diffusion method. Isolates showing resistance to cefotaxime, ceftizoxime, amikacin and imipenem were subjected to micro broth dilution assay to determine their MIC values. Isolates containing bla TEM were analyzed by Agarose Gel Electrophoresis (AGE). No other MBL genes were detected in this study. Six patterns were found for isolates containing bla TEM gene by AGE. The bla TEM was the main gene encoding MBLs among the isolates of P. aeruginosa in our study