Microevolution of antimicrobial resistance and biofilm formation of Salmonella Typhimurium during persistence on pig farms

Tassinari, Eleonora, Duffy, Geraldine, Bawn, Matt, Burgess, Catherine M, McCabe, Evonne M, Lawlor, Peadar G, Gardiner, Gillian and Kingsley, Robert A ORCID: https://orcid.org/0000-0002-0194-6485 (2019) Microevolution of antimicrobial resistance and biofilm formation of Salmonella Typhimurium during persistence on pig farms. Scientific Reports, 9. ISSN 2045-2322

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Abstract

Salmonella Typhimurium and its monophasic variant S. 4,[5],12:i:- are the dominant serotypes associated with pigs in many countries. We investigated their population structure on nine farms using whole genome sequencing, and their genotypic and phenotypic variation. The population structure revealed the presence of phylogenetically distinct clades consisting of closely related clones of S. Typhimurium or S. 4,[5],12:i:- on each pig farm, that persisted between production cycles. All the S. 4,[5],12:i:- strains carried the Salmonella genomic island-4 (SGI-4), which confers resistance to heavy metals, and half of the strains contained the mTmV prophage, harbouring the sopE virulence gene. Most clonal groups were highly drug resistant due to the presence of multiple antimicrobial resistance (AMR) genes, and two clades exhibited evidence of recent on-farm plasmid-mediated acquisition of additional AMR genes, including an IncHI2 plasmid. Biofilm formation was highly variable but had a strong phylogenetic signature. Strains capable of forming biofilm with the greatest biomass were from the S. 4,[5],12:i:- and S. Typhimurium DT104 clades, the two dominant pandemic clones found over the last 25 years. On-farm microevolution resulted in enhanced biofilm formation in subsequent production cycle.

Item Type: Article
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: LivePure Connector
Date Deposited: 01 Jul 2019 09:30
Last Modified: 31 Jan 2024 02:19
URI: https://ueaeprints.uea.ac.uk/id/eprint/71587
DOI: 10.1038/s41598-019-45216-w

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