The aim of this study was to quantify, identify, evaluate antimicrobial resistance, and characterize the virulence factors of enteropathogenic (EPEC), Shigatoxigenic (STEC), and enterohemorrhagic (EHEC) Escherichia coli in raw milk (RM) and legal (LMFC) and illegal (IMFC) Minas Frescal cheeses in southern and northeast Brazil. Illegal cheeses are those made without official inspection service or sanitary surveillance. We evaluated samples of RM produced in Paraná (southern) and Maranhão (northeast) States, LMFC produced using pasteurized milk in inspected industries, and IMFC potentially produced with raw milk. Mean total coliform counts were 8.4 × 10 4 cfu/mL for RM, 1.4 × 10 7 cfu/mL for LMFC, and 2.9 × 10 7 cfu/ mL for IMFC. Mean E. coli counts were 2.4 × 10 3 cfu/ mL for RM, 1.9 × 10 2 cfu/mL for LMFC, and 1.1 × 10 5 cfu/mL for IMFC. Among the 205 E. coli isolates from RM, 9.75% were identified as EPEC, mainly (90%) in samples from Paraná. Of the total isolates from the cheese samples, 97.4% (n = 111) came from IMFC, of which 1.8 and 2.7% were identified as EPEC and STEC, respectively; no EHEC was detected. The phylogenetic group A (60%) and typical EPEC (68%) predominated, which confirms the possible human origin of pathogenic isolates in RM and IMFC. Of these, 50% were resistant to at least one antibiotic, and streptomycin was the antimicrobial with the highest number (8) of EPEC and STEC resistant isolates. This study reports the first isolation of serogroup O28ac in Brazilian milk. We found no predominance of a specific serogroup of EPEC or STEC in milk or cheese or clonal isolates in the same sample, indicating different origins of the contamination in these products, presumably mostly related to poor hygienic handling.

The shelf life of milk and milk derivatives is directly related to the microbiological quality of refrigerated raw milk. Spoilage microorganisms with proteolytic and/or lipolytic properties are primarily responsible for the decrease in the quality of milk, which is reflected in the shelf life of pasteurized milk and all derivatives. The aim of this study was to determine the spoilage microbial load of refrigerated raw milk from the northeast and southern regions of Brazil, which have different climatic and technological conditions of production. We evaluated 46 samples of milk from the state of Paraná in the southern region, and 10 samples of milk from the state of Maranhão in the northeast region, totaling 56 samples collected from November 2013 to November 2014. The producers of Paraná were divided into large (20) or small (26) according to the average daily production. All producers of Maranhão were considered small (<500L/day). The proteolytic and lipolytic microorganism counts were conducted in milk agar and tributyrin agar, respectively. Milk from the large producers of Paraná had average counts of 1.4 × 10 4 CFU/mL for proteolytic microorganisms and 1.2 × 10 3 CFU/mL for lipolytics microorganisms, significantly (p <0.05) lower than the small producers in the same state, and the producers of Maranhão. Producers of Maranhao had counts of 1.1 × 10 5 CFU/mL for proteolytic microorganisms and 2 × 10 5 CFU/mL for lipolytic microorganisms, with the proteolytic count significantly lower than that of small Paraná producers. The amount of proteolytic and lipolytic spoilage microorganisms in milk is influenced by the adaptation of the microorganisms to cold, promoted by the cooling of milk, which is practiced less frequently in the country's northeastern region. The amount of spoilage microorganisms is also affected by the implementation of milking hygiene practices, which reduce contamination. Such practices are more frequently and efficiently implemented among large producers with more advanced technology, which can improve the microbiological quality of raw milk, thus increasing the shelf life of pasteurized milk, and reducing problems in UHT milk as well as milk derivatives. A vida útil do leite e de seus derivados está diretamente relacionada à qualidade microbiológica do leite cru refrigerado. Os micro-organismos deteriorantes proteolíticos e/ou lipolíticos são os principais responsáveis pela diminuição da qualidade tecnológica do leite, repercutindo na vida útil do leite pasteurizado, UHT e todos os derivados. Nesse contexto, o objetivo do presente trabalho foi determinar a carga microbiana deteriorante do leite cru refrigerado das regiões nordeste e sul do Brasil, que apresentam diferentes condições climáticas e tecnológicas de produção. Foram avaliadas 46 amostras de leite do estado do Paraná, região sul, e 10 amostras do Maranhão, região nordeste, totalizando 56 amostras coletadas no período de novembro de 2013 a novembro de 2014. Os produtores paranaenses foram divididos entre grandes (20) ou pe...

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The shelf life of milk and milk derivatives is directly related to the microbiological quality of refrigerated raw milk. Spoilage microorganisms with proteolytic and/or lipolytic properties are primarily responsible for the decrease in the quality of milk, which is reflected in the shelf life of pasteurized milk and all derivatives. The aim of this study was to determine the spoilage microbial load of refrigerated raw milk from the northeast and southern regions of Brazil, which have different climatic and technological conditions of production. We evaluated 46 samples of milk from the state of Paraná in the southern region, and 10 samples of milk from the state of Maranhão in the northeast region, totaling 56 samples collected from November 2013 to November 2014. The producers of Paraná were divided into large (20) or small (26) according to the average daily production. All producers of Maranhão were considered small (<500L/day). The proteolytic and lipolytic microorganism counts were conducted in milk agar and tributyrin agar, respectively. Milk from the large producers of Paraná had average counts of 1.4 × 10 4 CFU/mL for proteolytic microorganisms and 1.2 × 10 3 CFU/mL for lipolytics microorganisms, significantly (p <0.05) lower than the small producers in the same state, and the producers of Maranhão. Producers of Maranhao had counts of 1.1 × 10 5 CFU/mL for proteolytic microorganisms and 2 × 10 5 CFU/mL for lipolytic microorganisms, with the proteolytic count significantly lower than that of small Paraná producers. The amount of proteolytic and lipolytic spoilage microorganisms in milk is influenced by the adaptation of the microorganisms to cold, promoted by the cooling of milk, which is practiced less frequently in the country's northeastern region. The amount of spoilage microorganisms is also affected by the implementation of milking hygiene practices, which reduce contamination. Such practices are more frequently and efficiently implemented among large producers with more advanced technology, which can improve the microbiological quality of raw milk, thus increasing the shelf life of pasteurized milk, and reducing problems in UHT milk as well as milk derivatives. A vida útil do leite e de seus derivados está diretamente relacionada à qualidade microbiológica do leite cru refrigerado. Os micro-organismos deteriorantes proteolíticos e/ou lipolíticos são os principais responsáveis pela diminuição da qualidade tecnológica do leite, repercutindo na vida útil do leite pasteurizado, UHT e todos os derivados. Nesse contexto, o objetivo do presente trabalho foi determinar a carga microbiana deteriorante do leite cru refrigerado das regiões nordeste e sul do Brasil, que apresentam diferentes condições climáticas e tecnológicas de produção. Foram avaliadas 46 amostras de leite do estado do Paraná, região sul, e 10 amostras do Maranhão, região nordeste, totalizando 56 amostras coletadas no período de novembro de 2013 a novembro de 2014. Os produtores paranaenses foram divididos entre grandes (20) ou pe...