DETECTION OF NEW DELHI METALLO BETA LACTAMASES–1 GENE IN CLINICAL ISOLATES OF E.COLI IN A MULTISPECIALITY HOSPITAL.

Dr. Tejashree A.; Dr. Deepashree R.; Dr. Archana Hegde M; Dr. Devananda D.

Volume : VII, Issue : IX, September - 2017

DETECTION OF NEW DELHI METALLO BETA LACTAMASES–1 GENE IN CLINICAL ISOLATES OF E.COLI IN A MULTISPECIALITY HOSPITAL.

Dr. Tejashree A. , Dr. Deepashree R. , Dr. Archana Hegde M, Dr. Devananda D.

Abstract :

Carbapenemases are diverse enzymes that vary in their ability to hydrolyze carbapenems and other beta–lactams. Detection of carbapenemase is a crucial infection control issue because they are often associated with extensive antibiotic resistance, treatment failures and infection–associated mortality. Among the beta‑lactamases, the carbapenemases, especially transferrable metallo‑beta‑lactamases (MBLs) are the most feared because of their ability to hydrolyze virtually all drugs in that class, including the carbapenems. Currently, the bacteria receiving the most attention is New Delhi metallo–beta–lactamase–1 (NDM–1) producing superbug that confers resistance to most antibiotics including carbapenems. NDM–1 has been increasingly isolated from K.pneumoniae, E.coli, C.freundii, Morganella morgagnii, Providentia spp, Enterobacter cloacae.

Objective: The present study was undertaken to detect blaNDM–1 gene in clinical isolates of E.coli in Multispecialty hospital.

Materials & Methods: All clinical isolates of E.coli from patients attending out–patient and in–patient department at JSS hospital from December 2013 to November 2014. Samples received in the laboratory were subjected to routine processing. Antimicrobial susceptibility testing was according to CLSI guidelines. MBL production was detected both by Modified Hodge Test and EDTA–Disc Diffusion Synergy Test. Genotypically PCR was carried out for the detection of blaNDM–1 genes.

Result: Total of 1,579 E.coli were isolated from various clinical samples. Out of these, 100 non–repetitive isolates, which were also ESBL producers by phenotypic tests, were subjected for blaNDM–1 gene detection. In these 100 isolates, 27(27%) NDM–1 gene were detected by conventional PCR. Among 27 positive NDM–1 gene isolates, 16(59.25%) Metallo–β lactamase (MBL) production was detected both by Modified Hodge test and EDTA–Disc Diffusion Synergy tests for ESBL E.coli isolates. Out of 27(27%) NDM–1 positive isolates, 17(62.96%) isolates were also positive for CTX–M gene.

Conclusion: NDM–1 producing strains appear to be an emerging worldwide problem. Based on our findings, we conclude that genotypic assay could be considered in the diagnostic workflow as confirmatory method for carbapenemase production and/or as an identification tool for the most important different carbapenemase genes. When the presence of a carbapenemase is suspected, PCR is the fastest way to determine which family of β–lactamase is present. Hence timely detection of NDM–1 would help in timely institution of appropriate antibiotic therapy.