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Molecular epidemiology of Salmonella Infantis in Europe: insights into the success of the bacterial host and its parasitic pESI-like megaplasmid.
- Source :
-
Microbial genomics [Microb Genom] 2020 May; Vol. 6 (5). Date of Electronic Publication: 2020 Apr 09. - Publication Year :
- 2020
-
Abstract
- Salmonella Infantis is one of the five serovars most frequently causing human salmonellosis in Europe, mainly associated with poultry. A clone harbouring a conjugative plasmid of emerging S . Infantis (pESI)-like megaplasmid, carrying multidrug resistant (MDR) and extended-spectrum beta-lactamases (ESBL) genes, has spread in the Italian broiler chicken industry also causing human illness. This work is aimed at elucidating the molecular epidemiology of S . Infantis and pESI-like in Europe using whole-genome sequencing and bioinformatics analysis, and to investigate the genetic relatedness of S . Infantis clones and pESI-like from animals, meat, feed and humans provided by institutions of nine European countries. Two genotyping approaches were used: chromosome or plasmid SNP-based analysis and the minimum spanning tree (MST) algorithm based on core-genome multilocus sequence typing (cgMLST). The European S . Infantis population appeared heterogeneous, with different genetic clusters defined at core-genome level. However, pESI-like variants present in 64.1 % of the isolates were more genetically homogeneous and capable of infecting different clonal lineages in most of the countries. Two different pESI-like with ESBL genes ( n =82) were observed: bla <subscript>CTX-M-1</subscript> -positive in European isolates and bla <subscript>CTX-M-65</subscript> -positive in American isolates (study outgroup). Both variants had toxin-antitoxin systems, resistance genes towards tetracyclines, trimethoprim, sulphonamides and aminoglycosides, heavy metals ( mer A) and disinfectants ( qac EΔ). Worryingly, 66 % of the total isolates studied presented different gyr A chromosomal point mutations associated with (fluoro)quinolone resistance (MIC range 0.125-0.5 mg/L), while 18 % displayed transferable macrolide resistance mediated by mph , mef and erm (B) genes. Proper intervention strategies are needed to prevent further dissemination/transmission of MDR S . Infantis and pESI-like along the food chain in Europe.
- Subjects :
- Animal Feed microbiology
Animals
Bacterial Typing Techniques
Conjugation, Genetic
Drug Resistance, Multiple, Bacterial
Europe epidemiology
Genome, Bacterial
High-Throughput Nucleotide Sequencing
Humans
Meat microbiology
Molecular Epidemiology
Phylogeny
Phylogeography
Point Mutation
Polymorphism, Single Nucleotide
Salmonella genetics
Salmonella isolation & purification
United States epidemiology
Multilocus Sequence Typing methods
Plasmids genetics
Salmonella classification
Salmonella Infections epidemiology
Whole Genome Sequencing methods
Subjects
Details
- Language :
- English
- ISSN :
- 2057-5858
- Volume :
- 6
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Microbial genomics
- Publication Type :
- Academic Journal
- Accession number :
- 32271142
- Full Text :
- https://doi.org/10.1099/mgen.0.000365