Local and transboundary transmission of methicillin-resistant Staphylococcus aureus sequence type 398 through pig trading

Pirolo, M; Sieber, R N; Moodley, A; Visaggio, D; Artuso, I; Gioffrè, A; Casalinuovo, F; Spatari, G; Guardabassi, L; Stegger, M; Visca, P

Abstract

Livestock-associated methicillin-resistant Staphylococcus aureus sequence type (ST) 398 (LA-MRSA ST398) is a genetic lineage for which pigs are regarded as the main reservoir. An increasing prevalence of LA-MRSA ST398 has been reported in areas with high livestock density throughout Europe. In this study, we have investigated the drivers contributing to the introduction and spread of LA-MRSA ST398 along the pig farming system in Southern Italy. Whole-genome sequencing (WGS) of LA-MRSA ST398 isolates collected in 2018 from pigs (n=53) and employees (n=14) from 10 farms in the Calabria region were comparatively analysed with previously published WGS data from Italian ST398 isolates (n=45), an international ST398 reference collection (n=89) and isolates from Danish pigs farms (n=283), which are the main suppliers of pigs imported to Italy. Single-nucleotide polymorphisms (SNP) were used to infer isolates relatedness and, together with data from animal trading, factors contributing to LA-MRSA ST398 dissemination were identified. The analyses support the existence of two concurrent pathways for the spread of LA-MRSA ST398 in Southern Italy: i) multiple introductions of LA-MRSA ST398 through the import of colonized pigs from other European countries including Denmark and France and; ii) the spread of distinct clones dependent on local trading of pigs between farms. Phylogenetically related Italian and Danish LA-MRSA ST398 isolates shared extensive similarities including carriage of antimicrobial resistance genes. Our findings highlight the potential risk of transboundary transmission of antimicrobial-resistant bacterial clones with a high zoonotic potential when importing pigs from countries with high LA-MRSA prevalence.

Citation

Pirolo, M., Sieber, R. N., Moodley, A., Visaggio, D., Artuso, I., Gioffrè, A., Casalinuovo, F., Spatari, G., Guardabassi, L., Stegger, M., & Visca, P. (2020). Local and transboundary transmission of methicillin-resistant Staphylococcus aureus sequence type 398 through pig trading. Applied and Environmental Microbiology, https://doi.org/10.1128/AEM.00430-20

• Journal Article Type: Article
• Acceptance Date: Apr 1, 2020
• Publication Date: May 1, 2020
• Deposit Date: May 22, 2020
• Publicly Available Date: Aug 18, 2020
• Journal: Applied and Environmental Microbiology
• Print ISSN: 0099-2240
• Electronic ISSN: 1098-5336
• Publisher: American Society for Microbiology
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1128/AEM.00430-20
• Public URL: https://rvc-repository.worktribe.com/output/1377524