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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #115976
Title: COMPARISON OF CULTURE, MULTIPLEX AND 5' NUCLEASE PCR ASSAYS FOR THE RAPID DETECTION OF YERSINIA ENTEROCOLITICA IN SWINE AND PORK PRODUCTS

Author
item BOYAPALLE, SANDHYA - TUSKEGEE UNIVERSITY
item WESLEY, IRENE
item HURD, HOWARD
item REDDY, P - TUSKEGEE UNIVERSITY

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary: Yersinia enterocolitica is a major cause of human foodborne illness. Swine are major reservoirs for human pathogenic strains. Nearly all reported outbreaks in United States have been linked to contaminated foods, including pork. We estimated the prevalence of Y. enterocolitica in market weight swine, chitterlings, and ground pork using traditional culture methods and PCR-based assays (multiplex and TaqMan). The results suggest that processed pork products harbor more ail-bearing Y. enterocolitica than selected organs of freshly slaughtered hogs, and the TaqMan assay appears to be 1,000-10,000 times more sensitive than multiplex PCR and even more sensitive than culture methods in detecting ail-bearing Y. enterocolitica in food. These rapid and sensitive detection methods may help the pork producers to implement new regulations for control of foodborne pathogens in animal production systems and in packing plants. This may eventually lead to promote the quality of the product and satisfy the consumer demand in both domestic and export markets.

Technical Abstract: Bacteriological culture was compared with multiplex and fluorogenic (TaqMan) PCR assays for the detection of ail-bearing Y. enterocolitica in market weight swine, chitterlings, and ground pork. The TaqMan assay detected /= 1 ng of the same. The presence of ail-bearing Y. enterocolitica was tested in pork and feces artificially inoculated with Y. enterocolitica strain NADC 5561. The sensitivity limits of culture, multiplex, and TaqMan PCR assays were 4x10**3, 4x10**2, and 0.4 CFU/g, respectively, for the artificially inoculated pork, whereas the sensitivity limits were 4x10**2, 4x10**2, and 0.4 CFU/g, respectively, for feces after a 48-h enrichment in a Yersinia selective broth. By culture method, Y. enterocolitica was not detected in any of the swine specimens (N=2,403) examined. It was detected in 48 (2%) of the swine samples screened using the multiplex PCR assay and in 656 (27.2%) of these samples using the TaqMan assay. Using the culture method, Y. enterocolitica was detected in 8% of chitterling samples (N=350), and in none of the ground pork samples (N=350). It was identified in 27% of the chitterling samples using multiplex PCR and in 79% of these samples using the TaqMan assay. Ten percent of the ground pork samples contained Y. enterocolitica by the multiplex PCR and 38% based on the TaqMan assay. The results suggest that pork products harbor more ail-bearing Y. enterocolitica than selected organs of freshly slaughtered hogs, and the TaqMan assay appears to be more sensitive than either multiplex PCR or traditional culture methods.