Emergence of NDM in Association with OXA-48 Carbapenemase in Raoultella Terrigena from a Moroccan University Hospital in Casablanca, Morocco

Objective: The purpose of this study was to investigate the emergence of Raoultella terrigena, a rarely found opportunistic pathogen, co-producing NDM and OXA-48 carbapenemases in isolates recovered from various clinical specimens in our institution. Methods: From April 2020 to November 2021, we focused on strains of Enterobacteriaceae with reduced sensitivity to ertapenem giving rise to suspicion of the production of carbapenemases according to the CASFM-EUCAST criteria. These strains were isolated from samples for diagnostic purposes and identified in the microbiology laboratory of our institution. Only non-duplicate clinical and surveillance isolates obtained from patients were included. Results: Out of 159 Enterobacteriaceae suspected, 53 strains of Raoultella terrigena producing carbapenemases were isolated. Among these isolates, 64%(n=34) were NDM producers, 4% (n=2) were OXA-48 producers and 32% (n=17) had both the NDM and OXA-48. The co-existence of NDM and OXA-48 carbapenemases was found more often in Raoultella terrigena than Klebsiella pneumoniae. Among the seventeen isolates of Raoultella terrigena, all were multidrug-resistant. Conclusion: This study reported for the first time the emergence of NDM and OXA-48 carbapenemases co-existence in Raoultella terrigena isolates in our country which is starting to limit treatment options.