Multidrug resistance mediated by co‑carriage of extended‑spectrum beta‑lactamases, AmpC and New Delhi metallo‑beta‑lactamase‑1 genes among carbapenem‑resistant Enterobacteriaceae at five Indian medical centres.

ABSTRACT

In this study, we evaluated the coexistence of extended‑spectrum beta‑lactamases (ESBL), AmpC and New Delhi metallo‑beta‑lactamase‑1 (NDM‑1) genes among carbapenem‑resistant Enterobacteriaceae (CRE) recovered prospectively from patients at multiple sites. The study included 285 CRE strains from 2782 Gram‑negative Bacilli collected from multiple centres during 2007–2010, of which 87 were characterised. Standard and reference laboratory methods were used for resistance determination. Detection of blaNDM‑1, blaAmpC, blaTEM, blaSHV and blaCTX‑M was done by polymerase chain reaction. High levels of antimicrobial resistance observed among study isolates. Co‑carriage of ESBLs, AmpC and NDM‑1 was 26.3%. Nosocomial origin among the co‑carriage isolates was 64.3%, with 9.2% associated mortality.