Research Article: In vitro efficacy of potentiated egg yolk powder against Campylobacter jejuni does not correlate with in vitro efficacy

Date Published: March 7, 2019

Publisher: Public Library of Science

Author(s): Amina Soumaila Garba, Alexandre Thibodeau, Audrey Perron, Sylvette Laurent-Lewandowski, Ann Letellier, Philippe Fravalo, James E. Wells.


Campylobacter jejuni is a zoonotic agent responsible for the foodborne gastroenteritis campylobacteriosis. Control of C. jejuni load in the poultry primary production is recognized as an avenue to reduce human exposure to the pathogen. As for now, no commercially applicable control methods exist at the farm. Several studies tested egg yolk powders, potentiated or not against C. jejuni, as feed additives for chicken and suggested that the quantity and quality of the antibodies presence in the yolk are determinant factors for the full success of this approach. Unfortunately, data from these studies inconsistently showed a reduction of cecal C. jejuni carriage. Our first goal wwas to characterize (quantification by ELISA, agglutination test, bacterial antigen recognition profiles by Western blot, bactericidal effect by serum killing assays and C. jejuni mobility by soft agar migation) the antibodies extracted from egg yolk powders originating from different egg production protocols. Secondly, these powders were microencapsulated and recharacterized. Finally the protected powders were tested as a feed additive to destabilize C. jejuni colonization in an in vivo assay. Despite the in vitro results indicating the ability of the egg yolk powders to recognize Campylobacter and potentially alter its colonization of the chicken caecum, these results were not confirmed in the in vivo trial despite that specific caecal IgY directed toward Campylobacter were detected in the groups receiving the protected powders. More research is needed on Campylobacter in order to effectively control this pathogen at the farm.

Partial Text

Currently, campylobacteriosis is the most important bacterial foodborne disease in the world, evaluated to induce 7.5 million years of disability-adjusted life years (DALY) [1]. The economic costs associated with campylobacteriosis are tremendous [2]. Serious complications such as Guillain-Barré syndrome, reactive arthritis, and irritable bowel syndrome can be severe consequences of campylobacteriosis [3]. Handling or consumption of raw or undercooked poultry meat have been identified and regularly confirmed as a major source of human contamination by C. jejuni, the etiological agent of this foodborne disease [4, 5]. C. jejuni is a bacterium of the digestive tract acting like a commensal and thus being asymptomatically carried, up to 108 CFU / g [6]. This bacterium currently does not multiply in food during processing or storage, stressing the importance of on farm approach to reduce the amount of C. jejuni reaching the consumer [7]. Quantitative risk assessments indicated that a 3 log10 reduction of C. jejuni in the intestines of chickens or a reduction of 2 log10 on the carcass would efficiently reduce public health risks [8, 9].

Our results indicate that the different modes of IgY production are not equivalent in their ability to produce eggs powders with anti-C. jejuni activity. First In a quantitative perspective: anti-C. jejuni IgYs concentrations in OMP (subcutaneously injected with C. jejuni mix outer membrane proteins) or KB (subcutaneously injected with formalin-killed C. jejuni mix) derived EYP and EEYP were significantly higher than a per os inoculation (OI) (orally challenged with live C. jejuni mix) derived EYP or EEYP. Similar results were obtained for the egg yolks prior to transformation to EYP and subsequently to EEYP [23].




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