IngentaConnect Oral and Rectal Administration of Bacteriophages for Control of E...

Authors: Rozema, Erica A.¹; Stephens, Tyler P.²; Bach, Susan J.³; Okine, Erasmus K.⁴; Johnson, Roger P.⁵; Stanford, Kim²; McAllister, Tim A.⁶

Source: Journal of Food Protection®, Volume 72, Number 2, February 2009 , pp. 241-250(10)

Publisher: International Association for Food Protection

Abstract:

This study compared oral and rectal administration of O157-specific bacteriophages for mitigating the fecal shedding of Escherichia coli O157 by experimentally inoculated steers. Fecal shedding of nalidixic acid-resistant (Nal^R) E. coli O157:H7 was monitored over 83 days after oral (ORL; 3.3 × 10¹¹ PFU), rectal (REC; 1.5 × 10¹¹ PFU), both oral and rectal (O+R; 4.8 × 10¹¹ PFU), or no (CON; control) treatment with a four-strain O157-specific bacteriophage cocktail in multiple doses. Bacteriophages were enumerated by plaque assay, and Nal^R E. coli O157:H7 by direct plating on sorbitol MacConkey agar supplemented with cefixime, potassium tellurite, and nalidixic acid. Orally treated steers produced the fewest Nal^R E. coli O157:H7 culture-positive samples (P < 0.06) compared with REC and O+R steers, but this number was only nominally lower (P = 0.26) than that for the CON steers. The overall mean shedding level (log CFU per gram of feces) was higher for REC steers (P < 0.10) than for steers of the other treatment groups. Despite the shedding of higher mean bacteriophage levels (log PFU per gram of feces) by ORL and O+R than by CON and REC steers, there was no difference (P > 0.05) in the number of E. coli O157-positive samples among treatments. Bacteriophage was isolated from CON steers, indicating that these steers acquired the bacteriophage from the environment and shed the phage at a level similar to that of REC steers (P = 0.39). Continuous bacteriophage therapy may be an efficacious method for mitigating shedding of E. coli O157:H7 in cattle, providing that the host bacterium does not develop resistance. This therapy may be especially advantageous if nontreated cattle can acquire this biocontrol agent from the feedlot environment.

Document Type: Research article

Affiliations: 1: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5; Alberta Agriculture and Rural Development, Agriculture Centre, Lethbridge, Alberta, Canada T1J 4V6; Agriculture and Agri-Food Cana 2: Alberta Agriculture and Rural Development, Agriculture Centre, Lethbridge, Alberta, Canada T1J 4V6 3: Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, British Columbia, Canada V0H 1Z0 4: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5 5: Public Health Agency of Canada, Laboratory for Foodborne Zoonoses, Guelph, Ontario, Canada N1G 3W4 6: Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, Alberta, Canada T1J 4B1

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$37.00 plus tax Refund Policy

Oral and Rectal Administration of Bacteriophages for Control of Escherichia coli O157:H7 in Feedlot Cattle