Capacity of the bovine intestinal mucus and its components to support Escherichia coli O157:H7 growth

Kansas Agricultural Experiment Station Research Reports, Dec 2010

Escherichia coli O157:H7 contamination of human food products is a major concern for the beef industry. The pathogens responsible for outbreaks often originate from cattle, and E. coli O157:H7 can thrive in healthy cattle. To control contamination in the food chain, it is essential to understand how this pathogen is able to grow and compete with other bacteria in the gastrointestinal tracts of cattle. Previous studies have shown that bovine intestinal mucus supports bacterial colonization and can selectively influence makeup of the bacterial population. Intestinal mucus is made of mucins, which are gel-forming glycoproteins. Mucin molecules contain sialic acid that must be removed by neuraminidase enzyme to allow for complete degradation of mucin. E. coli O157:H7 lacks neuraminidase and should have little ability to degrade the complex mucin molecules. Our objective was to evaluate bovine intestinal mucus and its components in terms of their capacity to support E. coli O157:H7 growth in the presence or absence of feces and to understand the roles various enzymes play in this process.

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Capacity of the bovine intestinal mucus and its components to support Escherichia coli O157:H7 growth

Kansas Agricultural Experiment Station Research Reports C. Aperce J. Heidenreich James S. Drouillard Follow this and additional works at: https://newprairiepress.org/kaesrr Part of the Other Animal Sciences Commons Recommended Citation Aperce, C.; Heidenreich, J.; and Drouillard, James S. (2010) "Capacity of the bovine intestinal mucus and its components to support Escherichia coli O157:H7 growth," Kansas Agricultural Experiment Station Research Reports: Vol. 0: Iss. 1. https://doi.org/10.4148/2378-5977.2839 - This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 2010 Kansas State University Agricultural Experiment Station and Cooperative Extension Service. Contents of this publication may be freely reproduced for educational purposes. All other rights reserved. Brand names appearing in this publication are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. K-State Research and Extension is an equal opportunity provider and employer. Capacity of the bovine intestinal mucus and its components to support Escherichia coli O157:H7 growth Abstract Escherichia coli O157:H7 contamination of human food products is a major concern for the beef industry. The pathogens responsible for outbreaks often originate from cattle, and E. coli O157:H7 can thrive in healthy cattle. To control contamination in the food chain, it is essential to understand how this pathogen is able to grow and compete with other bacteria in the gastrointestinal tracts of cattle. Previous studies have shown that bovine intestinal mucus supports bacterial colonization and can selectively influence makeup of the bacterial population. Intestinal mucus is made of mucins, which are gel-forming glycoproteins. Mucin molecules contain sialic acid that must be removed by neuraminidase enzyme to allow for complete degradation of mucin. E. coli O157:H7 lacks neuraminidase and should have little ability to degrade the complex mucin molecules. Our objective was to evaluate bovine intestinal mucus and its components in terms of their capacity to support E. coli O157:H7 growth in the presence or absence of feces and to understand the roles various enzymes play in this process. Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 License. This research report is available in Kansas Agricultural Experiment Station Research Reports: https://newprairiepress.org/kaesrr/vol0/iss1/1436 Capacity of the Bovine Intestinal Mucus and Its Components to Support Escherichia coli O157:H7 Growth1 Introduction Escherichia coli O157:H7 contamination of human food products is a major concern for the beef industry. Thepathogens responsible for outbreaks often originate from cattle, and E. coli O157:H7 can thrive in healthy cattle. To control contamination in the food chain, it is essential to understand how this pathogen is able to grow and compete with other bacteria in the gastrointestinal tracts of cattle. Previous studies have shown that bovine intestinal mucus supports bacterial colonization and can selectively influence makeup of the bacterial population. Intestinal mucus is made of mucins, which are gel-forming glycoproteins. Mucin molecules contain sialic acid that must be removed by neuraminidase enzyme to allow for complete degradation of mucin. E. coli O157:H7 lacks neuraminidase and should have little ability to degrade the complex mucin molecules. Our objective was to evaluate bovine intestinal mucus and its components in terms of their capacity to support E. coli O157:H7 growth in the presence or absence of feces and to understand the roles various enzymes play in this process. Experimental Procedures Intestinal tissues from freshly harvested cattle were collected and transported to our laboratory in chilled saline. Sections of the ileum and colon were washed with buffer solution, and mucus was harvested by gently scraping the epithelium. We prepared a mix of five selected strains of Shiga toxin-producing E. coli O157:H7 resistant to nalidixic acid (NalR) and added the mix to a buffer or a similar amount of fecal inoculums collected from the rectum of a steer fed a high-grain diet. Subsequently, we added harvested intestinal mucus or individual mucus components to the culture to assess which components were most capable of supporting NalR E. coli O157:H7 growth. Intestinal mucus was added at a concentration of 10 mg/mL. Single components of mucus (galactose, D-galacturonic acid, D-gluconic acid, D-glucuronic acid, mannose, L-alpha-phosphatidylserine, sialic acid, and N-acetyl-D-glucosamine) were added at the same concentration, except for L-alpha-phosphatidylserine, which was added at 1 mg/mL. Initial concentrations of E. coli O157:H7 and fecal bacteria in the cultures (...truncated)


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C. Aperce, J. Heidenreich, James S. Drouillard. Capacity of the bovine intestinal mucus and its components to support Escherichia coli O157:H7 growth, Kansas Agricultural Experiment Station Research Reports, 2010, Issue 1,