First isolation of a NDM-like carbapenemase-producing Enterobacteriaceae in a public hospital in Rosario, Argentina

Abstract

Introduction: the emergence of carbapenemase-producing Enterobaceriaceae in the hospital environment represents a major challenge for health care worldwide. Carbapenemases are carbapenem-hydrolysing enzymes that confer resistance to these “last-line” antibiotics having a direct impact on the limited treatment options available. In Argentina, carbapenemases NDM-like (New Delhi Metallo-β-lactamase, MβL) have emerged in 2013. This resistance has increased in frequency and it has disseminated around the world at unprecedented levels.

Objective: report the first isolation of a NDM-producing Enterobacteriaceae in our hospital.
Materials and methods: the isolate analysed in this study was recovered from a bone biopsy belonging to an adult patient. The bacterial identification and antimicrobial susceptibility testings were performed using conventional methods and the automated system Vitek 2C (Biomérieux). Phenotypic and molecular techniques were carried out for the detection and characterization of carbapenemases.

Results: it was confirmed that the isolate, identified as Citrobacter freundii, produces the NDM enzyme. It showed sensibility to aztreonam, colistin and fosfomicyn. Extended-spectrum beta-lactamases were not detected.

Discussion: in this study we report the first isolation of NDM-like MβL in our institution, a multirresistant pathogen associated with a lack of effective antimicrobial treatment options. Given the high risk of these infections, an active search of mechanisms of resistance is mandatory. In addition, the establishment of accurate control measures is a must to attempt to overcome this formidable threat.