Genomic investigation of multispecies and multivariant blaNDM outbreak reveals key role of horizontal plasmid transmission.
Infect Control Hosp Epidemiol
; 45(6): 709-716, 2024 Jun.
Article
en En
| MEDLINE
| ID: mdl-38344902
ABSTRACT
OBJECTIVES:
New Delhi metallo-ß-lactamases (NDMs) are major contributors to the spread of carbapenem resistance globally. In Australia, NDMs were previously associated with international travel, but from 2019 we noted increasing incidence of NDM-positive clinical isolates. We investigated the clinical and genomic epidemiology of NDM carriage at a tertiary-care Australian hospital from 2016 to 2021.METHODS:
We identified 49 patients with 84 NDM-carrying isolates in an institutional database, and we collected clinical data from electronic medical record. Short- and long-read whole genome sequencing was performed on all isolates. Completed genome assemblies were used to assess the genetic setting of blaNDM genes and to compare NDM plasmids.RESULTS:
Of 49 patients, 38 (78%) were identified in 2019-2021 and only 11 (29%) of 38 reported prior travel, compared with 9 (82%) of 11 in 2016-2018 (P = .037). In patients with NDM infection, the crude 7-day mortality rate was 0% and the 30-day mortality rate was 14% (2 of 14 patients). NDMs were noted in 41 bacterial strains (ie, species and sequence type combinations). Across 13 plasmid groups, 4 NDM variants were detected blaNDM-1, blaNDM-4, blaNDM-5, and blaNDM-7. We noted a change from a diverse NDM plasmid repertoire in 2016-2018 to the emergence of conserved blaNDM-1 IncN and blaNDM-7 IncX3 epidemic plasmids, with interstrain spread in 2019-2021. These plasmids were noted in 19 (50%) of 38 patients and 35 (51%) of 68 genomes in 2019-2021.CONCLUSIONS:
Increased NDM case numbers were due to local circulation of 2 epidemic plasmids with extensive interstrain transfer. Our findings underscore the challenges of outbreak detection when horizontal transmission of plasmids is the primary mode of spread.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Plásmidos
/
Beta-Lactamasas
/
Brotes de Enfermedades
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
País/Región como asunto:
Oceania
Idioma:
En
Revista:
Infect Control Hosp Epidemiol
Asunto de la revista:
DOENCAS TRANSMISSIVEIS
/
ENFERMAGEM
/
EPIDEMIOLOGIA
/
HOSPITAIS
Año:
2024
Tipo del documento:
Article
País de afiliación:
Australia