Prevalence, genomic characteristics, and transmission dynamics of mcr-1-positive Salmonella enterica Typhimurium from patients with infectious diarrhea.
Int J Med Microbiol
; 311(4): 151501, 2021 May.
Article
en En
| MEDLINE
| ID: mdl-33866091
ABSTRACT
BACKGROUND:
Previous studies reported the prevalence of mcr-1 among clinical infected Salmonella isolates in China. However, the transmission dynamics of mcr-1 in different ecological niches were not well investigated. Our objective is to exhibit the transmission dynamics of mcr-1 in Salmonella.METHODS:
598 Salmonella isolates were recovered from ten hospitals; besides 936 pig faces and 167 pork samples were collected from January 2015 to December 2017 in Guangzhou, China. PCR and sequencing were used to identify mcr-1-positive Salmonella. Antimicrobial susceptibility testing was performed with 16 antimicrobials. Conjugation, S1-PFGE, and Southern blot were used to determine the transferability and location of mcr-1. Whole-genome sequencing was used to investigate pangenome, phylogeny, plasmid, and transposon.RESULTS:
Eleven mcr-1-positive Salmonella isolates were identified from patients with infectious diarrhea. Five pig fecal samples and three pork samples contained mcr-1-positive Salmonella isolates. All isolates were multi-drug resistant. The mcr-1 genes were located on â¼210-250 kb IncHI2-pST3 plasmids, and 12 mcr-1 genes were transferable. All isolates were assigned to ST34 or its genetically closed STs. The distribution of the core-genome network was significantly correlated with source distributions. The accessory genes-based network demonstrated that the diverse clonal complexes could share highly similar accessory genomes.CONCLUSIONS:
The prevalence of mcr-1-positive Salmonella among different sources was low. Clonal transmission could not be the main reason for the expansion of mcr-1-positive Salmonella, but be attributed to the horizontal transfer of IncHI2-pST3 plasmid. Continuous surveillance on Salmonella should be performed to investigate the response of colistin banning in food-producing animals by mcr-1-positive Salmonella populations.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Salmonella typhimurium
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Antibacterianos
Tipo de estudio:
Prevalence_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Animals
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Humans
País/Región como asunto:
Asia
Idioma:
En
Revista:
Int J Med Microbiol
Asunto de la revista:
MICROBIOLOGIA
Año:
2021
Tipo del documento:
Article