Detection of metalloβ-lactamase genes in heteroresistant Pseudomonas aeruginosa isolated from clinical isolates in Egypt

Abstract

The aim of the study is to isolate and characterize Pseudomonas aeruginosa recovered from different clinical specimens and then study the susceptibility of the isolated strains to different antibiotics, screening for heteroresistant isolates and detecting the metalloβ-lactamase genes in these isolates. A total of two hundred and fifty clinical isolates were collected, from which one hundred forty five isolates revealed Pseudomonas aeruginosa. They were collected from different clinical specimens applied for bacteriological testing from hospitalized in-patients admitted to Kasr Al Aini Hospital and Al-Demerdash Hospital, Egypt, in the period from February 2016 to December 2017. Antibiotic susceptibility testing was done using ten antibiotics. The study covered the heteroresistance of P.aeruginosa towards several classes of antibiotics to make the statistical analysis convenient and to overview the significance of this resistance. The minimum inhibitory concentration was detected for the heteroresistant P.aeruginosa resistant isolates. The polymerase chain reaction of the heteroresistant strains was performed to detect the metallo-β-lactamase genes SIM, IMP and SPM and then sequencing was done consequently. SIM, IMP and SPM metalloβ-lactam e genes were detected in the heteroresistant isolates. The isolates showed a high resistance pattern to ampicillin (98.62%) and a high sensitivity rate to imipenem (96.55%) and the IMP gene was the highly significant gene.