Mechanisms of carbapenem resistance among clinical isolates of Escherichia coli in a tertiary care hospital

Abstract

The emergence and global spread of carbapenem-resistant is of great concern to the health care facilities due to high rates of morbidity and mortality associated with them. It is necessary to know its epidemiology and the resistant pattern in a geographical area to formulate a antibiotic stewardship policy. To study the occurrence and mechanisms of carbapenem resistance in Escherichia coli.A total of 1172 clinical strains of obtained from various clinical specimens were screened for carbapenem resistance during the study period. Strains showing reduced susceptibility to imipenem &/or ertapenem &/or meropenem were included in the study. The resistance mechanisms were identified using various phenotypic methods. Total of 53/1172 were found to be carbapenem resistant (CRE). The most common sample in which CRE were isolated was urine (n=26, 49.1%). A total of 50 isolates were confirmed as Metallo-beta-lactamase (MBL) producers using Ezy MIC strip. One of the three non carbapenemase producing isolate was positive for ESBL with porin loss and the other two isolates were positive for AmpC with porin loss.MBL production being the most common mechanism of carbapenem resistance, the study indicates the importance of regular monitoring of drug resistance in the hospital for an urgent action to be taken for antibiotics stewardship in the institute.