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Bovine milk fat globule membrane affects virulence expression in Escherichia coli O157:H7

A Tellez1, M Corredig, A Guri

  • 1Department of Food Science; Canadian Research Institute for Food Safety, University of Guelph, Guelph, ON, N1G 2W1, Canada.

Journal of Dairy Science
|September 18, 2012
PubMed

Insights

Bovine milk fat globule membrane (MFGM) can inhibit virulence factors in Escherichia coli O157:H7. Heated MFGM showed a stronger effect on Shiga toxin and motility genes, suggesting a novel mitigation strategy.

Area of Science:

  • Food Science
  • Microbiology
  • Molecular Biology

Background:

  • Escherichia coli O157:H7 is a significant foodborne pathogen.
  • Virulence factors, such as Shiga toxin and motility, contribute to E. coli O157:H7 pathogenicity.
  • Bovine milk fat globule membrane (MFGM) is a complex biological structure with potential bioactivity.

Purpose of the Study:

  • To investigate the impact of bovine MFGM on the expression of virulence genes in E. coli O157:H7.
  • To compare the effects of raw and heat-treated MFGM preparations.

Main Methods:

  • Extraction of MFGM from raw and heat-treated milk.
  • Quantification of Shiga toxin (stx) and flagellin (fliC) gene expression in E. coli O157:H7 exposed to MFGM preparations.
  • Analysis of gene expression ratios to determine inhibitory effects.

Main Results:

  • Both raw and heated MFGM significantly inhibited Shiga toxin gene expression.
  • Heated MFGM demonstrated a more pronounced inhibitory effect on Shiga toxin gene expression (ratio of -7.69) compared to raw MFGM (ratio of -5.96).
  • Heated MFGM also significantly reduced the expression of the motility gene fliC (ratio of -9.43).

Conclusions:

  • Bovine MFGM possesses specific inhibitory effects on key virulence factors of E. coli O157:H7.
  • Heat treatment enhances the inhibitory capacity of MFGM, particularly on motility-related genes.
  • MFGM presents a promising natural approach for mitigating E. coli O157:H7 infections.

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