Microbiological quality indicators in waters of dairy farms: Detection of pathogens by PCR in real time

When contaminated water is used to wash the udders of dairy cattle and milking utensils, raw milk may become contaminated with pathogens. Washing with high quality water is essential to reduce the microbial contamination of milk. Furthermore, the wastewater generated in dairy herds also contains high populations of pathogens, antibiotics and nutrients that more often are thrown into the water bodies without any treatment. In this work, both supply water and wastewater from 20 dairy farms from Antioquia, Colombia was monitored for 10months to determine the presence of pathogenic microorganisms. Both Cryptosporidium and Fasciola were determined by the Polymerase Chain Reaction (PCR) technique in real time. The results showed that the supply water used for drinking and activities involving the herd, has high populations of Fasciola hepatica and Cryptosporidium parvum, with percentages of about 53.7% and 64.75% respectively. Additionally high populations of Pseudomonas aeruginosa, Shigella, Salmonella, total coliforms and Escherichia coli were found in both types of water, with values around 9.4×107, 2.1×107, 1.8×107, 1.9×1010 and 1.5×1010 UFC/100ml respectively for the wastewater and 3.1×104, 1.9×104, 7.3×103, 1.2×105 and 6.2×103 UFC/100ml for the supply water. ► The results indicated a high degree of contamination by pathogens in both the supply water and wastewater in the study area. ► There was a direct relationship between some pathogens found and the location of the municipalities of Antioquia. ► The need to implement best management practices, water use and reuse to prevent pollution to nearby sources was found.