Estudio microbiológico de la leche cruda comercializada en mercados populares de la ciudad de Riobamba provincia de Chimborazo.

Abstract

A study was conducted of seven sales stalls of raw milk in the Market of San Alfonso, La Condamine and Mercado Mayorista de Riobamba, to assess the presence of pathogenic bacteria. The collected samples were seeded in agar Farrell, it was quantified the colonies obtained, and it was isolated in Mueller Hinton Agar being obtained 33 bacterial strains, after, they were identified by Gram test, catalase, oxidase, gelatin hydrolysis, starch hydrolysis, biochemical tests: urea and citrate. For the identification of gender and species were used multiplied systems like: Analytical Profile Index (API). The amount of bacterias was lower for all samples to 1.5 x 106 UFC/mL. The bacteria were found and their percentages in relation to the total were: 27.27% of bacteria of genus Bacillus, 17.39% of Brucella spp. and Aeromonas hydrophila, 13.04% of Enterobacter sakazakii and 4.35% Serratia plymuthica, Escherichia coli, Burkodelia cepacia, Pseudomona aeruginosa, Staphylococcus warneri. It was also performed a resistance test to meropenem and imipenem (antibiotics) from which it was found a resistance in a 6.25% of the cases. The results obtained not fulfilled with the Ecuadorian Technical Standard 9. Raw Milk. Requirements, which it establish that in raw milk, there must be absence of pathogenic microorganism, therefore, the sale of this raw milk constitutes in a risk to public health. It concludes that the contamination probably is because it did not apply, good milking practices, transport or storage. It is recommended to make a new follow-up study in the dairy chain so that it can find Critical Control Points can in turn be solved.