Author : Nikhita C Ved, Rudresh S M, Ravi G S, Malini J, Raksha Yoganand
Abstract : Introduction: The emergence and global spread of carbapenem-resistant E. coli 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
Objective: To study the occurrence and mechanisms of carbapenem resistance in Escherichia coli.
Materials and Methods: A total of 1172 clinical strains of E. coli 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.
Results: Total of 53/1172 were found to be carbapenem resistant E. coli (CRE). The most common sample
in which CRE were isolated was urine (n=26, 49.1%). A total of 50 isolates were confirmed as Metallobeta-
lactamase (MBL) producers using Ezy MICTM 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
Conclusion: 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.
Keywords: Escherichia coli, Carbapenem resistance, Super bug, Carba NP, MBL, Carbapenem resistance mechanisms.