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Development of a PCR-based method for detection of Yersinia enterocolitica in pork

Thisted Lambertz, Susanne (2005). Development of a PCR-based method for detection of Yersinia enterocolitica in pork. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2005:123
ISBN 91-576-6922-8
[Doctoral thesis]

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During the last decade, Yersinia enterocolitica has been reported to cause between 500 and 800 cases of human gastroenteritis per year in Sweden. As pigs are the only animals in human food production that regularly harbour the pathogen, pork is probably an important source of infection. Earlier it has only rarely been possible to recover the bacterium from pork, but in the last few years this was made possible by DNA-based technology. In this project, a PCR-based method for the detection of pathogenic Y. enterocolitica in pork was developed. The chromosome-located gene attachment invasion locus (ail) was chosen as the PCR-target. The ail PCR assay was evaluated according to criteria for a standardised PCR-based method set by the European research project FOOD-PCR. In a trial involving 14 European laboratories, the ail PCR assay showed high repeatability and robustness. The complete PCR-based method comprises a sample treatment step prior to the ail PCR assay. The assay consists of either one (single) or two (nested) PCR analyses and an internal amplification control for monitoring false-negative results. The detection limit of the complete (single) PCR method, using inoculated enriched homogenates, was established to 10 cfu or less per gram. An increased sensitivity in the form of a nested PCR was required to enable detection of the bacterium in naturally contaminated pork. This is in practice very important. Finally, for characterisation of isolated strains, a multiplex PCR assay was developed, directed towards four different virulence-associated genes (yst, rfbC, ail and virF). As presence or absence of the four PCR targets was established, the following groups were identified: pathogenic Y. enterocolitica 4/O:3 strains, pathogenic Y. enterocolitica serotypes other than 4/O:3, Y. pseudotuberculosis strains and nonpathogenic strains. The method does not allow for confirmation of the viability of the pathogen, the reason being that the bacterium cannot be isolated by traditional culture. The method can therefore preferably be used where information about viability is not important, for example in studies to identify the critical points during slaughter, important to limit contamination by the bacterium.

Authors/Creators:Thisted Lambertz, Susanne
Title:Development of a PCR-based method for detection of Yersinia enterocolitica in pork
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :November 2005
Number of Pages:60
ALLI. Thisted Lambertz, S., Ballagi-Pordány, A., Nilsson, A., Norberg, P. & Danielsson-Tham, M-L. 1996. A comparison between a PCR method and a conventional culture method for detecting pathogenic Yersinia enterocolitica in food. Journal of Applied Bacteriology 81, 303-308. II. Thisted Lambertz, S., Ballagi-Pordány, A. & Lindqvist R. 1998. A mimic as internal standard to monitor PCR analysis of food-borne pathogens. Letters in Applied Microbiology 26, 9-11. III. Thisted Lambertz, S., Lindqvist, R., Ballagi-Pordány, A. & Danielsson- Tham, M-L. 2000. A combined culture and PCR method for detection of pathogenic Yersinia enterocolitica in food. International Journal of Food Microbiology 57, 63-73. IV. Thisted Lambertz, S. & Danielsson-Tham, M-L. 2005. P PIdentification and characterization of pathogenic Yersinia enterocolitica by PCR and PFGE. Applied and Environmental Microbioogyl 71, 3674-3681. V. Thisted Lambertz, S., Granath, K., Fredriksson-Ahomaa, M., Johansson, K- E. & Danielsson-Tham, M-L. Evaluation of a combined culture and PCR method for detection of pathogenic Yersinia enterocolitica in food. In manuscript.
Place of Publication:Uppsala
ISBN for printed version:91-576-6922-8
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:Q Food science > Q03 Food contamination and toxicology
Subjects:Not in use, please see Agris categories
Agrovoc terms:yersinia enterocolitica, bacterioses, foodborne diseases, pork, pcr, analytical methods, laboratory experimentation
Keywords:PCR, Yersinia enterocolitica 4/O:3, foodborne pathogen, sample treatment, buoyant density centrifugation, internal amplification control, pork
Permanent URL:
ID Code:980
Department:(VH) > Dept. of Biomedical Sciences and Veterinary Public Health
Deposited By: Susanne Thisted Lambertz
Deposited On:15 Nov 2005 00:00
Metadata Last Modified:02 Dec 2014 10:08

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