AUTHOR=Lienen Tobias , Mateus-Vargas Rafael Hernán , Steinhoff-Wagner Julia , Richter Martin H. , Maurischat Sven 

TITLE=High toxinogenic potential of Staphylococcus aureus from wild ungulates in Brandenburg, Germany with a low level of antibiotic resistance

JOURNAL=Frontiers in Veterinary Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1445413

DOI=10.3389/fvets.2024.1445413

ISSN=2297-1769

ABSTRACT=<sec id="sec21"><title>Introduction</title><p>Data regarding the occurrence and virulence of <italic>Staphylococcus</italic> (<italic>S</italic>.) <italic>aureus</italic> in wild living animals is rare. However, <italic>S. aureus</italic> may carry a multitude of virulence factors and express resistance to several antimicrobial substances. Handling game meat may thus lead to serious infections or food poisoning. The aim of this study was to provide insights into the occurrence and characteristics of <italic>S. aureus</italic> in wild ungulates from Brandenburg, Germany.</p></sec><sec id="sec22"><title>Methods</title><p>Nasal swabs of externally healthy-looking wild boars, roe, fallow and red deer were collected in hunts during season 2021/2022 and analyzed for <italic>S. aureus</italic> by selective enrichment. Species were determined using matrix assisted laser desorption ionization mass spectrometry and tested for phenotypic antimicrobial resistance. Whole-genome sequencing was conducted for genotyping, determination of virulence associated genes and analysis of phylogenetic relationships.</p></sec><sec id="sec23"><title>Results</title><p><italic>S. aureus</italic> were recovered from approximately 8% of nasal swabs. However, the strains were only obtained from the sampled wild ruminants. <italic>S. aureus</italic> isolates were associated with sequence types (ST) 1, ST30, ST133, ST425, ST582 and ST6238. Isolates of ST1 clustered closely together in the phylogenetic analysis. Genes encoding staphylococcal enterotoxin (SE) or SE-like (SEl) were found in 14/17 isolates. In particular, a <italic>seh</italic> gene was present in 12/17 isolates. Moreover, two isolates harbored a multiplicity of genes encoding SE or SEl. In addition, the toxic shock syndrome toxin encoding <italic>tst</italic> gene was detected in one isolate. This isolate was resistant to penicillin and cefoxitin and accordingly harbored the <italic>blaZ</italic> gene.</p></sec><sec id="sec24"><title>Discussion</title><p>Wild ungulates intended for human consumption may carry potentially virulent <italic>S. aureus</italic>. In one case, the close phylogenetic relationship of <italic>S. aureus</italic> isolates indicates a possible intraspecific spread within a common territory. However, for others, the origin or the spread pattern can only be inferred. Handling of animals or their carcasses might contribute to staphylococcal infections in humans. Moreover, food poisoning due to SE producing strains may occur, if recommended hygiene practices are not applied during processing of game meat.</p></sec>