Hazards in non-pasteurized milk on retail sale in Brazil: prevalence of Salmonella spp, Listeria monocytogenes and chemical residues

Fluctuations in the Brazilian milk market force small milk producers to find temporary trade alternatives, which include selling raw milk to people who prefer this type of milk rather than heat-processed milk. Considering the importance of these small milk producers to the market and the well-known health risks associated to consumption of raw milk, this study evaluated the microbiological quality and the presence of Listeria monocytogenes, Salmonella spp., chlorine, antimicrobials and insecticides (organophosphates and carbamates) in raw milk produced in 210 small and medium farms located in four important milk-producing Brazilian states (Paraná, São Paulo, Minas Gerais and Rio Grande do Sul). In 66% of the selected farms the milking was manual. In 33% of them, the milking was semi-automatic, and only 1% were equipped with fully automatic milking systems. All raw milk samples were negative for L. monocytogenes, Salmonella spp and chlorine. Mesophilic aerobes counts were higher than 10(5) CFU/ml in 75.7% of the samples. In 80.4%, coliforms were over 10² CFU/ml. Escherichia coli was detected in 36.8% of the samples. Insecticides and antimicrobial residues were observed in 74.4% and 11.5% of the samples, respectively. The presence of unacceptable levels of hygiene indicators, insecticides and antimicrobial residues were considered more important risk factors than the two pathogens. A instabilidade do mercado de leite no Brasil força pequenos produtores de leite a procurar alternativas de comércio de sua produção, o que inclui a venda de leite cru para indivíduos que dão preferência a esse tipo de leite. Considerando a importância desse mercado e os conhecidos riscos à saúde que o consumo de leite cru pode representar, este estudo avaliou a qualidade microbiológica e a presença de Listeria monocytogenes, Salmonella spp., resíduos de cloretos, antimicrobianos e inseticidas (organofosforados e carbamatos) em leite cru produzido em 210 propriedades leiteiras localizadas em quatro importantes estados produtores de leite no Brasil (Paraná, São Paulo, Minas Gerais e Rio Grande do Sul). Em 66% das propriedades selecionadas, a ordenha era manual. Em 33% a ordenha era semi-automática (ordenha mecânica balde ao pé) e em apenas 1% o sistema de ordenha e armazenamento era totalmente mecânico (sistema fechado). Todas as amostras de leite cru foram negativas para L. monocytogenes, Salmonella spp e resíduos de cloretos. As contagens de aeróbios mesófilos foram superiores a