A shortened enrichment procedure (25°C for 24 h) was compared with cold enrichment procedures (4°C for 1 to 3 weeks) and direct plating for isolation of Yersinia enterocolitica from commercial ground meat samples. The combined data of all recovery procedures showed that
this organism was isolated from 34% of the ground beef samples. The highest isolation rate was 32% for the 4°C/3-week enrichment, followed by 28% for the 4°C/2-week enrichment, 26% for the 25°C/24-h enrichment, 22% for the 4°C/1-week enrichment, and 10% for direct plating.
No significant differences (P > 0.05) in isolation rate occurred between the 4°C/3-week, 4°C/2-week, 25°C/24-h, and 4°C/1-week enrichments. The combined data of all recovery procedures showed that Y. enterocolitica was isolated from 64% of ground pork samples.
The highest isolation rate was 48% for the 4°C/3-week enrichment, followed by 40% for the 25°C/24-h enrichment, 34% for the 4°C/2-week enrichment, 24% for the 4°C/1week enrichment, and 24% for direct plating. No significant differences (P > 0.05) in isolation rate
occurred between the 4°C/3-week, 25°C/24-h, and 4°C/2-week enrichments. During the plating phase of the experiment, the efficiency of a dyecontaining, Yersinia-selective medium (KV202) was compared with that of a commercially available cefsulodin-irgasan-novobiocin medium.
Recovery rates were similar for both media. However, KV202 agar differentiated Y. enterocolitica from such contaminating bacteria as Enterobacter, Serratia, and Salmonella by colony morphologic characteristics and color.
Document Type: Research Article
Food Microbiology Laboratory, Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66506-1600, USA
Publication date: November 1, 2000
More about this publication?
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