# Pasteurized Milk Harboring Diarrheagenic E. coli Virulence Genes: Biosurveillance and New Insights for Enhancing Food Safety Standards

## TL;DR

This study found harmful E. coli genes in pasteurized milk, suggesting post-pasteurization contamination and the need for better food safety practices.

## Contribution

The study identifies DEC-specific virulence genes in pasteurized milk, highlighting post-pasteurization contamination risks.

## Key findings

- A 5% noncompliance rate was found in Enterobacteriaceae counts, indicating post-pasteurization contamination.
- The ipaH and elt genes were detected in 14.28% of E. coli-positive milk samples.
- The findings emphasize the need for improved food safety standards to protect vulnerable populations.

## Abstract

Members of the family Enterobacteriaceae are often linked to foodborne outbreaks, including acute diarrhea, with diarrheagenic Escherichia coli (DEC) as the most common cause of this disease in low- and middle-income countries. A cross-sectional study was carried out to evaluate the sanitary conditions of ready-to-consume milk, involving 750 pasteurized milk samples. These samples were analyzed for the Enterobacteriaceae count, the presence of Salmonella spp., and the enumeration of E. coli, as well as checking for the presence of DEC-specific virulence genes. Two molecular assays were used to detect DEC-specific virulence genes (eae, bfpA, aggR, ipaH, est, elt, stx1, and stx2). Overall, a significant noncompliance rate (5%) was identified in the Enterobacteriaceae counts, indicating postpasteurization contamination. Two genes (ipaH and elt) were detected in 14.28% of E. coli-positive samples, highlighting the need for improved methods to minimize postpasteurization contamination in dairy plants. This improvement could contribute to better food safety standards internationally. Additionally, further studies are necessary to understand the actual risk posed by these strains circulating in milk for immunocompromised individuals or those with immature immune systems. This underscores a global concern for vulnerable populations worldwide.