The production of New Delhi Metallo-β-lactamase (NDM) by Enterobacterales has a major impact on antimicrobial therapy, particularly in multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains, significantly limiting treatment options. Additionally, the co-production of NDM and Klebsiella pneumoniae carbapenemase (KPC) has emerged and may result in pandrug-resistant phenotypes. This study aimed to describe the local epidemiology of infections caused by NDM- and NDM+KPC-producing Enterobacterales, correlating clinical and microbiological data.

Bacterial isolates producing NDM or co-producing NDM and KPC were analyzed from various clinical specimens (urine, tracheal aspirate, blood, surgical wounds) collected from patients admitted to a university hospital between January and June 2025. Detection of NDM and KPC was performed using an immunochromatographic assay for carbapenemases, and bacterial identification was carried out by MALDI-TOF. Clinical data were obtained through chart review.

During the study period, 36 NDM-producing isolates and 9 NDM+KPC co-producing isolates were identified, comprising Klebsiella pneumoniae (n = 27), Klebsiella oxytoca (n = 1), Klebsiella variicola (n = 2), Enterobacter cloacae(n = 12), Escherichia coli (n = 1), and Kluyvera intermedia (n = 2). The majority (n = 16, 35%) were isolated from urine samples, followed by tracheal aspirates (n = 9, 20%). A total of 33 patients were affected, with a median age of 63 years; 42% (n = 14) were hospitalized in clinical wards and 21% (n = 7) in intensive care units. Five patients (15.2%) were immunosuppressed, and the overall mortality rate was 42% (n = 14).

A significant circulation of NDM-producing Enterobacterales was observed, mainly K. pneumoniae and E. cloacae, predominantly from urinary and tracheal aspirate samples. The detection of isolates co-producing NDM and KPC highlights the potential for dissemination of even broader resistance phenotypes, directly impacting available therapeutic options. These findings underscore the importance of active microbiological surveillance, strict infection control measures, and rational antimicrobial use to prevent the spread of these clinically and epidemiologically relevant strains.