Detección de Listeria Spp. Y Listeria Monocytogenes en Muestras de Leche Cruda y Quesos Artesanales Respectivamente, Mediante Pcr en Tiempo Real

Background. In Ecuador, studies on bacteria of the Listeria genus are scarce in artisanal cheeses and practically nonexistent in raw milk. Milk production is one of the main livestock activities in the province of Pichincha and it is essential to study these products. Since all the cantons that make up Pichincha are milk producers, three of them, Cayambe, Quito and Pedro Moncayo, were randomly sampled. Objective. To determine Listeria spp. and Listeria monocytogenes in samples of raw milk and artisan cheeses, respectively, by Real Time PCR. Methods. The application of the qPCR technique in the detection of microorganisms, especially bacteria in food, is based on four fundamental aspects: its sensitivity, specificity, speed and capacity to process a large flow of samples. It is possible to detect small quantities of pathogenic microorganisms, such as Listeria spp. in raw milk, after extraction and quantification of total DNA. Results. In this study in raw milk, 1 positive sample out of a total of 60 samples was determined, representing 1.6% of Listeria spp. and 16 positive samples out of 45, representing 35.6% of Listeria monocytogenes in artisanal cheeses from three farms in the province of Pichincha. Conclusions. The results, according to the statistical analysis performed with the Kruskal-Wallis test, show that in Pichincha the bacterium is present in raw milk, but in non-representative quantities, while for Listeria monocytogenes there is statistical significance in the samples of artisanal cheeses.