Growth and Enrichment Medium for Detection and Isolation of Shiga Toxin–Producing Escherichia coli in Cattle Feces
Source: Journal of Food Protection®, Number 5, May 2008, pp. 886-1088 , pp. 927-933(7)
Abstract:Detection methods of Shiga toxin–producing Escherichia coli (STEC) in cattle feces varied in using enrichment media containing different antibiotic combinations. To examine efficacy of a new detection method for STEC, three O157:H7 (ATCC 43889, 43890, and 43895) and 41 non-O157:H7 (members of the O1, O15, O26, O86, O103, O111, O125, O127, O128, O136, O146, O153, O158, O165, O166, and O169 serogroups) isolates were tested. These isolates were grown in tryptic soy broth for 6 h, and their concentrations were determined before inoculation of tubes containing 1 g of cattle feces (sterile [experiment 1; evaluating growth] and fresh [experiment 2; evaluating enrichment]) to simulate the high and low levels of STEC shedding by cattle (105 versus 102 CFU/g feces, respectively). Eight STEC isolates (the three O157:H7 and five non-O157:H7 selected at random) were tested at a very low level (10 CFU/g feces). The feces were incubated in 50 ml of brain heart infusion broth containing potassium tellurite, novobiocin, and vancomycin (2.5, 20, and 40 mg/liter, respectively) and cefixime (50 g/liter) at 37°C for 12 h and tested for STEC (VTEC [verotoxin-producing E. coli]–Screen assay [agglutination immunoassay]). Potential STEC isolates were recovered, characterized biochemically, serotyped, and tested for toxin production using Vero (African green monkey kidney) cell toxicity assay and agglutination immunoassay. In both experiments, all the STEC isolates used for fecal inoculation were recovered at the concentrations tested. Our medium supported growth of and enrichment for a wide range of STEC isolates.
Document Type: Research Article
Affiliations: 1: Department of Animal Biotechnology, University of Nevada–Reno, Reno, Nevada 89557, USA 2: Department of Animal Biotechnology, University of Nevada–Reno, Reno, Nevada 89557, USA; Department of Microbiology and Immunology, University of Nevada–Reno, Reno, Nevada 89557, USA
Publication date: 2008-05-01
- IAFP members must first sign in on the right to access full text articles of JFP First published in 1937, the Journal of Food Protection®, is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection® is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: email@example.com or Web site: www.foodprotection.org
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- ingentaconnect is not responsible for the content or availability of external websites