## 4 Discussion
monocytogenes_ in cheeses is related to its ability to survive and/or multiply in these products and in the cheese-processing environment, which results in the formation of persistent biofilms [16]. When cleaning and sanitation procedures are inadequate, _L. monocytogenes_ can colonize and persist in food processing plants for years [17]. After colonization, _L. monocytogenes_ can easily spread through contaminated contact materials, inadequate personnel movement, and food workflows [16]. The lack of hygiene at the retail level is another factor that contributes to the occurrence of _L. monocytogenes_ in cheeses. Handling procedures, such as cutting an entire wheel of cheese into smaller portions or slicing it for sale, present additional risks of cross-contamination by compromising the traceability as one single contaminated cheese wheel can be cut several times before reaching the consumer [25; 26]. In this sense, the study of [PERSON] et al. [17] indicated that _L. monocytogenes_ was absent in samples of mozzarella cheese when collected directly from the producers, but the samples were positive when collected from retail stores (18.8%) after slicing. [PERSON] et al. [15] reported that pasteurized milk cheese contaminated with _L. monocytogenes_ was the cause of a large outbreak in 2008 in Quebec, Canada. Wide cross-contamination was evidenced when the same strain was isolated from the environment of the cheese processing factory, from the environment of the retailers selling the cheese, as well as from different batches of the cheese. The majority of the samples that tested positive for _L. monocytogenes_ was negative for total coliforms, staphylococci, and _E. coli_ (Table 2), which corroborates studies that indicate the strong competition between these microorganisms: when present in large quantities, the probability of detecting _L. monocytogenes_ is lower [36]. The higher positivity outcome for _Salmonella_ spp. and _L. monocytogenes_ in cheeses when the pathogens were investigated using real-time PCR applied to the pre-enrichment brotts versus using conventional culture methods can be explained by the greater sensitivity and specificity of the PCR method [37]. Low populations of pathogens in food in association with the sublethal injury caused by processing, in addition to competition with other bacteria, make their detection more difficult when conventional cultivation methods are employed [36]. In 32% of the samples, the counts of coagulase-positive staphylococci were above \(10^{3}\) CFU/g, i.e., these samples were in disagreement with the Brazilian federal legislation that establishes this maximum limit (M) for cheees in retail environments [19]. All coagulase-positive staphylococci isolates were identified as _Staphylococcus aureus_. The occurrence of _Staphylococcus aureus_ in the Minas artisanal cheese samples was expected since this genus is frequently detected in bulk tank milk, and it has also been found in the skin and mucous membranes of animals and humans, the surfaces of dairy equipment, and the milking environment [8]. Artisanal cheese production, in particular, is characterized by frequent manipulation, increasing the transfer potential of _Staphylococcus_ spp. from employees, utensils, and equipment to the final products [1]. For these reasons, _Staphylococcus_ spp. is considered a good indicator of whether proper handling and manufacturing practices are maintained during cheese processing [25]. The favorable, intrinsic conditions encountered in the cheeses, such as pH, water activity, and NaCl concentration, favor the growth of _Staphylococcus_ spp. [9; 18]. Although controversial, the capability of producing enterotoxins and coagulase has always been associated with the pathogenic potential of _Staphylococcus_ spp. [8]. Therefore, official guidelines in Brazil and other countries consider the counts of these microorganisms as a safety benchmark [19; 20], where high counts indicate hygiene failures during cheese production or marketing and a possible health risk for consumers.