## 4 Discussion
Since similar genetic mechanisms are at play in antibiotic resistance, selection pressure may eventually contribute to the emergence of multi-resistant bacteria with the potential to impact public health [41], as evidenced in this study. Previous studies have shown that decreased susceptibility to chlorheximide in methicillin -resistant _S. aureus_ (MRSA) was associated with the _qac A, qac B_, and _smr_ genes [40]. The mechanisms underlying tolerance/resistance indicate that biocide tolerance genes and antibiotic resistance genes are located on the same mobile genetic elements [42]. Mutations in _pmrB_ and the upregulation of efflux pump genes contributed to antibiotic resistance in _Pseudomonas aeruginosa_ after exposure to benzalkonium chloride [42]. The most recent studies suggest that biocide-induced antibiotic resistance is more likely to become a contributing factor when bacteria are repeatedly exposed to sub-inhibitory concentrations of biocidal agents in disinfectants, increasing the chances of the co-selection of antibiotic-resistant bacteria [41; 43]. Furthermore, these resistant bacteria were shown to be able to form strong biofilms on surfaces in the cheese production environment, with consequent hazards for public health and for the quality of the final products [37; 44]. However, biocide-induced antibiotic resistance seems to be bacterial species- or strain-dependent: _Listeria monocytogenes_ isolates obtained from food production plants and tolerant to BC did not present cross-resistance to clinically relevant antibiotics [45]. Most of the _S. aureus_ strains isolated from the cheeses presented enterotoxin genes, predominantly for non-classical enterotoxins such as SEH and SEG. Despite the knowledge that the presence of these genes does not mean that the corresponding enterotoxins are produced, as genes require complex machinery for expression, these results are worrisome, and confer additional preoccupation to the current knowledge that the occurrence of enterotoxicigenic _S. aureus_ in Minas artisanal cheeses is common [26; 46; 47; 48]. The prevalence of non-classical enterotoxin _seh_ gene in _S. aureus_ isolated from Brazilian artisanal raw-milk cheeses, reported by previous studies, corroborates our findings [26; 49]. The increasing predominance of non-classical staphylococcal enterotoxin genes demonstrates the importance of investigating these new enterotoxins in dairy foods when testing their safety. Also worrisome is that nearly one third of the _S. aureus_ isolates harboring enterotoxin genes were resistant to at least one biocide, and harbored genes of resistance to the main antibiotics used in clinical medicine. Tetracycline and methicillin are used in intensive livestock production, which may explain the resistance observed in bacteria obtained from animal products, such as cow's milk [26]. As pointed out for other types of cheese, _S. aureus_ in these products deserves attention due to the potential risk to public health, especially when it accumulates resistance to antimicrobials, tolerance to biocides and production of enterotoxins that cause serious food poisoning [23]. The occurrence of _S. aureus_ is mainly attributed to the inappropriate use of antimicrobial drugs and biocides in human and veterinary medicine, such as unnecessary use, incorrect choice, wrong dosage, short contact time, or irregular application [38]. Within the One Health perspective, it is necessary to address the possible transfer of microbial resistance genes between humans, animals, wildlife, plants, and the environment [50].