Bacteriological analysis of raw milk sold in Tarqui-Ecuador

Abstract

Introduction. Raw milk, being a food source, is susceptible to microbial contamination during manual milking. However, it can contain bacteria such as Staphylococcus aureus, Total coliforms, and Escherichia coli, leading to various foodborne illnesses. To identify Staphylococcus aureus, Escherichia coli, and Total coliforms in raw milk samples sold in Tarqui, Ecuador, using Compact Drt X-SA and EC plates. Methodology. A cross-sectional and observational descriptive study was conducted. The study universe comprised the raw milk samples sold in Tarqui, Ecuador. A non-probabilistic convenience sampling method was employed, obtaining twenty raw milk samples. Results. Among the raw milk samples, 50% exhibited coliforms in dilutions of 1:100 and 1:1000. Additionally, 15% of the analyzed samples evaluated positive for E. coli. S. aureus exceeded the established limits, with a presence of 70% in the 1:100 dilution and 25% in the 1:1000 dilution. It is important to note that rejection limits may vary depending on the standards set by each country, as there is no standardized norm. Conclusion. In this study, the counts of S. aureus revealed high values, surpassing the rejection limits. On the other hand, E. coli registered 15% contamination, while coliform contamination ranged from 35% to 50% in raw milk. The interpretation of contamination indicators should be based on the specific standards established by each country.