Correlation of Anti-Salmonella Antibodies Between Serum and Saliva Samples Collected From Finisher Pigs.

Alessia De Lucia,Francesca Martelli,Richard P Smith,Shaun Cawthraw,Fabio Ostanello,Rob Davies,Carlo Bianco

doi:10.3389/fvets.2019.00489

Alessia De Lucia, Francesca Martelli + Show 5 more

Open Access

https://doi.org/10.3389/fvets.2019.00489

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Abstract

Saliva samples obtained by using absorptive devices, can provide an alternative diagnostic matrix to serum for monitoring disease status in pigs. The aim of this study was to investigate the correlation of anti-Salmonella antibodies between serum and saliva samples collected from pigs. Twenty individual paired serum and saliva samples were collected from a single farm. Anti-Salmonella IgG was detected in individual serum samples using a commercial Salmonella ELISA kit, validated for sera. The same kit was used with a protocol modified by extending incubation time and increasing temperature to test individual saliva samples. Anti-Salmonella IgG antibodies in pig saliva were always detected at a lower level than in the matching serum samples. A correlation (rho = 0.66; p = 0.002) and a moderate agreement (K > 0.62 p = 0.003) was found between individual Salmonella IgG in serum and saliva samples. Both correlation and the agreement levels are moderate. The size of this investigation was small, and further studies are necessary to further confirm these findings. The results of this work provide some evidence that saliva samples have the potential to be used for the diagnosis of Salmonella infection in pig farms.

Highlights

Salmonella is an important foodborne pathogen and the consumption of contaminated pork meat is one of the major sources of human outbreaks [1]
Oral fluid is composed of saliva and a transudate that originates from oral capillaries, gingival crevicular fluid that leaks from the crevices between teeth and gum [7]
In this study we modified the protocol of a commercial ELISA kit validated for serum and meat juice in order to test individual and pooled saliva samples and pen-based oral fluid (OF) samples for the presence of anti-Salmonella antibodies in finisher pigs

Summary

Introduction

Salmonella is an important foodborne pathogen and the consumption of contaminated pork meat is one of the major sources of human outbreaks [1]. In the latest Europe-wide survey, the prevalence of Salmonella in United Kingdom pigs was amongst the highest in Europe [2]. Oral fluid (OF) diagnostic technology has been rapidly gaining interest for veterinary medicine as a convenient and rapid diagnostic measure of disease status in pigs [5, 6]. Oral fluid is composed of saliva and a transudate that originates from oral capillaries, gingival crevicular fluid that leaks from the crevices between teeth and gum [7].

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