Detection of Yersinia enterocolitica O:3 in faecal samples and tonsil swabs from pigs using IMS and PCR

Abstract

Dilutions of faecal samples spiked with Yersinia enterocolitica O:3 were analysed using immunomagnetic separation (IMS) followed by PCR. In 10% faecal dilutions with added Y. enterocolitica cells, the limit of detection was 200 cells g-1 faeces. Faecal samples from 38 pigs were analysed by IMS-PCR in parallel with detection and quantification of Y. enterocolitica O:3 using cold pre-enrichment culturing. Of the 15 culture-positive samples, only two were detected with IMS-PCR. These two samples contained 40-400 Y. enterocolitica O:3 cells g-1 faeces; the highest level found in the investigation. This indicated that the low sensitivity of IMS-PCR was due to low amounts of cells in the faecal samples. Swab samples from 195 pig tonsils, taken on a slaughterline were examined using IMS-PCR and culture detection. Of 164 culture-positive samples, 60 were positive with IMS-PCR. In addition, IMS-PCR was positive for three culture-negative samples. Forty-five of the samples were further examined by IMS-PCR after 7-10 d of cold pre-enrichment. All 31 culture-positive samples as well as five culture-negative samples were detected by IMS-PCR. From these data it can be concluded that IMS-PCR can be used to detect Y. enterocolitica O:3 cells after pre-enrichment, but direct detection needs further optimization of the sample preparation procedures.

Low Occurrence of Pathogenic Yersinia enterocolitica in Clinical, Food, and Environmental Samples: a Methodological Problem

“…In addition, ethidium bromide, which is a mutagen, is used to stain the agarose gel and may not be appropriate for routine use in food-monitoring laboratories. To overcome these problems, Rasmussen et al (119) detected the amplified products of Y. enterocolitica by capture of the products using hybridization to an immobilized oligonucleotide. The immobilized PCR products in microtiter wells were detected with fluorescence.…”

Maximizing Capture Efficiency and Specificity of Magnetic Separation for Mycobacterium avium subsp. paratuberculosis Cells

“…(22), and Escherichia coli O157:H7 (15), magnetic separation is generally applied after an enrichment culture step. This enrichment culture step aims to dilute food components known to be growth/PCR inhibitors, revive stressed or injured cells, and boost the numbers of the target bacterium (18,21), so that magnetic separation and subsequent detection are likely to be more successful. Unfortunately, a prior enrichment culture step is impractical for M. avium subsp.…”

Pathogenic Strains ofYersinia enterocoliticaIsolated from Domestic Dogs (Canis familiaris) Belonging to Farmers Are of the Same Subtype as PathogenicY. enterocoliticaStrains Isolated from Humans and May Be a Source of Human Infection in Jiangsu Province, China

“…Two outbreaks causing more than 500 infections were reported in China in the 1980s (24). Yersinia enterocolitica has a broad animal reservoir, with swine being the most common source of infection for humans (10,11,13,18). Y. enterocolitica is distributed among a diverse range of animals in China.…”