Relation Between Serology of Meat Juice and Bacteriology of Tonsils and Feces for the Detection of EnteropathogenicYersiniaspp. in Pigs at Slaughter

Abstract

The association between positive serology and culture detection of Yersinia spp. in individual pigs was determined. Pieces of diaphragm from 370 pig carcasses were collected for serological analysis, and tonsils and feces of the same carcass were collected for bacteriological analysis. Detection of anti-Yersinia antibodies in meat juice samples was done using an indirect enzyme-linked immunosorbent assay (ELISA) based on Yops (Yersinia outer proteins). Tonsils and feces were tested for the presence of enteropathogenic Yersinia spp. by direct plating on cefsulodin-irgasan-novobiocin agar plates. Of the 370 meat juice samples, 241 (65.1%) gave a positive serological reaction using a cutoff value of 20%. Enteropathogenic Yersinia spp. (Yersinia enterocolitica serotype O:3 and Yersinia pseudotuberculosis) were found in tonsils of 161 pigs and feces of 30 pigs. Recovery of enteropathogenic Yersinia from the tonsils was highly correlated with positive serotiters, whereas no correlation was found between serology and fecal excretion. Results demonstrated that serology has an acceptable sensitivity, but a relatively low specificity for the rapid detection of enteropathogenic Yersinia spp. in tonsils of pigs at slaughter.

Meat Juice Serology and Improved Food Chain Information as Control Tools for Pork‐Related Public Health Hazards

“…was the highest of the pathogens studied, although it was similar to or slightly lower than in previous studies from Germany and Belgium (von Altrock et al., ; Meemken et al., ; Van Damme et al., ). Higher seroprevalence was expected, based on previous studies in which the isolation rates of pathogenic Y. enterocolitica in slaughter pig tonsils were 52% in Finland and 29–93% in other parts of Europe (Korte et al., ; Fredriksson‐Ahomaa et al., ; Ortiz Martinez et al., , ; Van Damme et al., ; Vanantwerpen et al., ). Usually, pigs are infected during the fattening period, and the antibodies typically remain detectable until slaughter (Nesbakken et al., ).…”

“…Usually, pigs are infected during the fattening period, and the antibodies typically remain detectable until slaughter (Nesbakken et al., ). The high number of Yersinia ‐seropositive farms was not surprising, considering the results of previous studies (von Altrock et al., ; Meemken et al., ; Van Damme et al., ). However, in only a quarter of the farms did all the pigs studied here show antibodies to Yersinia , possibly because the pigs may have originated from different compartments of the same farm.…”

Relevance of Meat Juice Seroprevalence and Presence of Yersinia enterocolitica and Salmonella spp. in Pig Tonsils for Risk Management at Slaughter

“…Most authors associate a higher prevalence with a high production capacity of the farm and the density of the livestock, which was also observed in this work. However, the prevalence observed in our study is lower compared to some European studies and previous reports from Croatia [21][22][23][24][25]. However, the large discrepancy between studies in terms of reported prevalence of Y. enterocolitica in pig tonsils at slaughter can be attributed to numerous factors, such as tonsil sampling strategy, slaughter processing (like tying the rectum/removing the head before carcass splitting or not) or the methods used in pathogen isolation and identification [26].…”

Controlled Experimental Infection in Pigs with a Strain of Yersinia enterocolitica Harboring Genetic Markers for Human Pathogenicity: Colonization and Stability

“…This hypothesis could be supported by the fact that microscopy and microbiota analysis have indicated that Ye is able to colonize deep tonsil tissue and form microcolonies ( 35 – 37 ). Serological evidence also supports this hypothesis, because a close association between seropositivity and isolation of Ye from minced tonsils has been shown ( 38 ). After 21 dpi, Ye was not detected in all swab samples, but systematically high serological values obtained at each sampling time point may suggest the presence of Ye in tonsils, possibly in deeper tonsil tissue.…”