A simplified method for detecting pathogenic Yersinia enterocolitica in slaughtered pig tonsils

Area of Science:

• Veterinary Microbiology
• Food Safety
• Bacteriology

Background:

• Pathogenic Yersinia enterocolitica is a significant foodborne pathogen.
• Swine tonsils are a reservoir for Yersinia enterocolitica.
• Accurate and efficient detection methods are crucial for public health.

Purpose of the Study:

• To evaluate a simplified ITC-CIN method for detecting pathogenic Yersinia enterocolitica in pig tonsils.
• To compare the efficacy of the simplified method with the standard ISO 10273 method.
• To assess the prevalence of pathogenic Yersinia enterocolitica in French slaughter pigs.

Main Methods:

• Collection of 900 pig tonsil swabs from a French slaughterhouse.
• Enrichment using PSB and ITC broths, followed by streaking on CIN, SSDC, and chromogenic YeCM media.
• Comparison of the ITC-CIN-YeCM method with the ISO 10273 standard method.
• Biochemical assays for Yersinia identification and biotyping.

Main Results:

• The ITC-CIN-YeCM method detected pathogenic Yersinia enterocolitica in 14.0% of tonsil swabs and 68.9% of batches, outperforming the ISO 10273 method (9.1% swabs, 60% batches).
• Pathogenic Yersinia enterocolitica identification was confirmed in 97.0% of colonies from YeCM medium.
• Biotype 4 was the most prevalent (80.5%), followed by biotype 3.

Conclusions:

• The ITC-CIN method combined with YeCM chromogenic medium offers an effective and efficient alternative for isolating pathogenic Yersinia enterocolitica from pig tonsils.
• This simplified method reduces time and the need for extensive biochemical testing.
• The findings contribute to improved surveillance and control of Yersinia enterocolitica in swine populations.