New Delhi metallo-β-lactamase-producing Acinetobacter baumannii in the USA from October, 2013, to March, 2022: a retrospective molecular epidemiological analysis

Résumé fourni par la source

Background Most US carbapenem-resistant Acinetobacter baumannii (CRAB) isolates harbour carbapenem-hydrolysing class D β-lactamases. Other carbapenemases, such as New Delhi metallo-β-lactamase (NDM), are uncommon but emerging. We describe the epidemiology of NDM-producing CRAB reported to the US Centers for Disease Control and Prevention (CDC). Methods We defined cases as A baumannii with bla NDM confirmed by molecular testing and isolated from any specimen source from a patient in the USA between Oct 1, 2013, and March 31, 2022, and passively reported to the CDC from regional, state, local public health, and CDC laboratories. Epidemiologically linked cases had epidemiological linkage (eg, overlapping health-care facility stay) with one or more other cases. We assessed case relatedness through analysis of whole-genome sequence data using traditional multilocus sequence typing (MLST; Oxford scheme [sequence type OX ]) and core genome MLST. To understand the potential origins of NDM-CRAB in the USA, we compared sequences of cases to US CRAB without NDM and to NDM-CRAB from non-US locations. Findings We identified 327 NDM-CRAB cases from 264 patients in 21 US states. Among patients with available epidemiological information, 192 (90%) of 214 had epidemiological linkage to at least one additional case and 13 (7%) of 193 were hospitalised outside the USA 12 months or less before index specimen collection. Five regionally distinct sequence type clusters were identified among the 264 case patients; three (sequence type OX 218, sequence type OX 281, and sequence type OX 1697) were closely related to international NDM-CRAB isolates. Interpretation We identified regionally distinct NDM-CRAB strains, suggesting localised transmission in the USA. Some NDM-CRAB strains in the USA are closely related to strains identified outside the USA, suggesting that spread followed importation. Funding None.

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