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.