Speaker
Description
Raw milk is a key exposure route for zoonotic pathogens including Staphylococcus (S.) aureus in low- and middle-income countries. S. aureus causes food intoxication and severe infections; pandemic clones circulate across human and animal reservoirs, raising One Health concerns. We characterised genomic diversity, AMR, and virulence potential of S. aureus from the Zambian dairy value chain and assessed global phylogenetic context.
Whole-genome sequencing (Illumina) data from 94 isolates collected across farms, collection centres, processors, traders, and markets (Lusaka, Southern, Western Provinces) were analysed. Analyses comprised MLST, cgMLST, AMR/virulence gene detection, and maximum-likelihood phylogenetics using 7,054 global assemblies of bovine and human origin.
Predominant local sequence types were ST97 (23.4%), ST152 (16.0%), and ST7344 (13.8%). AMR genes were detected in 69.1% of isolates. All ST152 carried PVL genes; local ST152 were closely related to human blood culture isolates from Malawi. The tsst-1 gene was present in all ST7344 and four ST152 isolates. cgMLST revealed identical or near-identical isolates spanning multiple supply chain levels and provinces, indicating active transmission.
Circulation of the pandemic clone ST152, carrying PVL genes and tsst-1, across the Zambian dairy supply chain poses a direct One Health risk. Targeted control measures are needed.
Keywords
S. aureus; dairy milk chain; Zambia; whole-genome sequencing; phylogeny; toxic shock syndrome toxin (TSST); Pantone-Valentine leucocidin (PVL)
| Registration ID | #62 |
|---|---|
| Professional Status of the Speaker | Senior Scientist |
| Junior Scientist Status | No, I am not a Junior Scientist. |
Author
Co-authors
External references
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