Abstract
Monitoring data on Staphylococcus (S.) aureus in wild animals are scarce, yet transmission to humans and livestock remains a concern. S. aureus can cause infections in humans and animals, and the production of staphylococcal enterotoxins (SEs) may cause food poisoning. This study monitored the occurrence of S. aureus in wild ungulates intended for human consumption in Brandenburg, Germany. A total of 323 nasal swabs were collected from wild boar, roe, fallow, and red deer during the 2023/24 hunting season. Samples were analyzed by selective enrichment. Isolates were identified using MALDI-TOF MS. Whole-genome sequencing was used for analyses of genotypes, antimicrobial resistance (AMR) and virulence genes as well as phylogeny. Phenotypic AMR was also determined. S. aureus was recovered from 58 swabs (18 %), exceeding the occurrence in 2021/22 (8 %) by over twofold. Fallow deer showed the highest detection rate (39 %), followed by red deer (32 %), roe deer (16 %), and wild boar (10 %). S. aureus isolates represented diverse sequence types (STs), with a majority of ST1, ST133 and ST425. Some isolates showed high clonality, despite originating from different hosts. Genes encoding SE or SE-like (SEl) proteins were found in 26 isolates and the toxic shock syndrome toxin encoding tsst-1 gene in one. AMR gene carriage was low, though one isolate carried resistance genes to beta-lactams, macrolides, and aminoglycosides. Wild ungulates may carry enterotoxigenic S. aureus. Foodborne illness can be prevented by hygiene and temperature control during processing and storage of game meat, while safe carcass handling can reduce the risk of infection.