New Delhi metallo-β-lactamases among extensively drug-resistant clinical isolates from Lahore, Pakistan

Aim: The study determines rates of carbapenem resistance (CR) and frequency of bla(NDM) in multidrug-resistance (MDR) or extensive drug resistance (XDR), and evaluates the potential of phenotypic tests for detecting NDM production. Materials & methods: Singleplex PCR was used to detect bla(NDM). Phenotypic tests, including combination disc test (CDST) and modified Hodge test (MHT), were evaluated for NDM production. Results: Among 338 CR isolates, 47.63% were MDR, whereas 52.36% were XDR with 53.25% carrying bla(NDM). MHT was found to be discriminative for detecting NDM production, whereas no significant association was observed for CDST. Conclusion: The high incidence of CR and MDR and XDR isolates possessing bla(NDM) presents an impending threat in therapeutics. Limitations of phenotypic tests suggest better testing, including molecular detection of the enzyme.