Microbial Contamination in Milk: Detection, Prevention, and Safety Measures with Emphasis on Salmonella spp. and Escherichia coli

https://doi.org/10.5281/zenodo.19535865

Abstract

Milk is a highly nutritious food but is also highly susceptible to microbial contamination, posing significant public health risks. This study aimed to evaluate the prevalence of Salmonella spp. and Escherichia coli in milk, along with assessing detection methods and identifying key factors contributing to contamination. A total of 50 milk samples were collected from dairy farms, vendors, and retail shops in Lahore, Punjab, Pakistan. Standard microbiological techniques were used for isolation and identification, followed by molecular confirmation using polymerase chain reaction (PCR) targeting invA and uidA genes. The results revealed that 30% of samples were contaminated with Salmonella spp., while 42% were positive for E. coli. Higher contamination levels were observed in vendor and retail samples compared to farm samples, indicating poor hygiene and inadequate storage conditions during distribution. Total bacterial counts ranged from 1.2 × 10⁴ to 3.8 × 10⁶ CFU/mL, exceeding acceptable safety limits in several cases. PCR analysis confirmed the accuracy and sensitivity of conventional detection methods. The findings highlight the critical need for improved sanitary practices, proper pasteurization, and implementation of food safety management systems such as HACCP. Public awareness and strict regulatory enforcement are essential to reduce microbial contamination and ensure safe milk consumption. This study provides valuable insights into milk safety and emphasizes the importance of continuous monitoring to protect consumer health.