Role of bacterial association and penetration on destruction of Escherichia coli O157:H7 in beef tissue by high pH

10Citations
Citations of this article
13Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

This study was undertaken to determine if association with collagen enables Escherichia coli O157:H7 to resist high-pH treatments and to determine the effects of high pH on the survival of E. coli O157:H7 within different layers of beef tissue. E. coli O157:H7 was inoculated onto purified bovine type I collagen on 12-mm2 circular glass coverslips, plain 12-mm2 circular glass coverslips (control), and 12-mm2 irradiated (cobalt-60) lean beef tissue. The rates of destruction of E. coli O157: H7 inoculated on coverslips in pH 10.5 NaHCO3-NaOH buffer at 35°C were determined at various sampling times. E. coli O157:H7 cells associated with collagen and treated in the same manner were also examined using scanning electron microscopy to determine if association with collagen enabled the organism to resist high-pH treatments. The inoculated tissue was treated in pH 13.0 NaHCO3-NaOH buffer at 25°C, and penetrating cells of E. coli O157:H7 were recovered using a cryostat technique. There was no significant difference (P < 0.05) between the rates of destruction of collagen-associated E. coli O157:H7 and non-collagen-associated E. coli O157:H7 following exposure to high-pH treatments. Scanning electron micrographs showed that collagen-associated E. coli O157:H7 cells appeared physically damaged by exposure to high-pH treatments, and association of E. coli O157:H7 to collagen did not increase the resistance of the organism to destruction by high-pH rinses. No significant differences were seen between 20 ml of NaHCO3-NaOH buffer at pH 13.0 (treatment) and 20 ml of distilled water at pH 7.0 (control) when E. coli O157:H7 cells were recovered in beef tissue at depths of up to 2,000 μm (P < 0.05). The ability of E. coli O157:H7 to penetrate beef tissue may be an important factor in reducing the effectiveness of high-pH treatments in killing this organism on beef tissue. This finding should be considered in the future when designing treatments to decontaminate beef carcasses.

Cite

CITATION STYLE

APA

Woody, J. M., Walsh, R. A., Doores, S., Henning, W. R., Wilson, R. A., & Knabel, S. J. (2000). Role of bacterial association and penetration on destruction of Escherichia coli O157:H7 in beef tissue by high pH. Journal of Food Protection, 63(1), 3–11. https://doi.org/10.4315/0362-028X-63.1.3

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free