Genetic characterization and dissemination of Staphylococcus aureus and Staphylococci genus: food and health perspective

Hospitals and communities are significant hubs for antibiotic-resistant staphylococcal infections, but recently there have been spread of the Staphylococci to other settings including farms and food chains. This study aimed to compare the methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans and food to understand the genetic characteristics and similarities between the circulating clones across both groups. A total of 250 samples of meat (camel, beef, chicken, fish, and lamb) were collected from different retailers in Riyadh, Saudi Arabia. Culture, and Genomics analysis of the isolates yielded 53 S.aureus out of which (42/53; 79%) were methicillin-sensitive S.aureus (MSSA) and (11/53; 21%) were MRSA in addition to to other Staphylococci. 80 clinically confirmed MRSA isolates were obtained from patients in the same city. The most common S. aureus clone in patients and retail meat belonged to clonal complex (CC5). In meat, ST6 and ST97 were the most common clones found in (6/11; 54.5%) of MRSA isolates, and ST1153 (9/42; 21.42%), ST672 (7/42; 16.66%) of MSSA isolates. The majority of MRSA isolates in meat carried SCCmec type V, which was observed in (6/11; 54.54%) of isolates. While in patients, ST5 and ST6 were the predominant clones found in (37/80; 46%) of MRSA isolates. The most prevalent SCCmec types in MRSA isolates from patients were SCCmec type IVa, which was observed in (39/80; 48.7%) of isolates. While there was no MRSA found in beef, camel meat had the highest prevalence of MRSA ST6-t2450 contamination. The other two clones, CC97 and CC361, were the second-most prevalent clones in meat and were relatively common among patients. Novel S. aureus lineages were sequenced and characterized for the first time ST8109 from meat and ST8110 and ST8111 from patients. A structured One Health approach on S. aureus considering its dissemination, genetic characterization, antibiotic resistance, and overall impact on food intended for human consumption and its effect on human health is advised.