High prevalence of avian adapted CC5Staphylococcus aureus isolates in poultry meat in Spain: food chain as vehicle of MRSA and MSSA CC398‐t1451.

Summary: Staphylococcus aureus can cause food poisoning and human infections and CC5 and CC398 are relevant lineages in the animal‐human interface. The objective was to determine the S. aureus prevalence in chicken‐derived food, and to study the diversity of lineages, and their antimicrobial resistance and virulence genotypes. Sixty poultry‐food samples were processed, and the S. aureus isolates obtained were characterised. Antibiotic susceptibility was performed and the presence of resistance/virulence genes, and avian mobile genetic elements (MGEs) was studied. Forty‐four non‐repetitive S. aureus isolates were obtained of 28/60 samples (46.7%), and 43 methicillin‐susceptible (MSSA) and one methicillin‐resistant S. aureus (MRSA) isolates were detected. Five S. aureus isolates were multidrug‐resistant and 50% of isolates showed susceptibility to all tested antibiotics. Eighteen spa‐types, 11 sequence‐types and 8 clonal‐complexes were identified in the S. aureus collection. Three CC398 isolates (2 MSSA/1 MRSA) of spa‐type‐t1451 were detected, and MSSA‐CC398 isolates harboured the scn‐gene (absent in MRSA‐CC398). CC5 was the most frequent lineage identified (56.8%), all MSSA, and 56.7% of them contained avian‐MGEs. A high prevalence of avian‐adapted MSSA‐CC5 isolates was detected. Poultry meat has been shown to be a vehicle for CC398‐t1451 isolates, both MRSA and MSSA, showing characteristics of the animal and human clades, respectively. [ABSTRACT FROM AUTHOR]