Promising new vaccine candidates against Campylobacter in broilers

Abstract

Campylobacter is the leading cause of human bacterial gastroenteritis in the European Union. Birds represent the main reservoir of the bacteria, and human campylobacteriosis mainly occurs after consuming and/or handling poultry meat. Reducing avian intestinal Campylobacter loads should impact the incidence of human diseases. At the primary production level, several measures have been identified to reach this goal, including vaccination of poultry. Despite many studies, however, no efficient vaccine is currently available. We have recently identified new vaccine candidates using the reverse vaccinology strategy. This study assessed the in vivo immune and protective potential of six newly-identified vaccine antigens. Among the candidates tested on Ross broiler chickens, four (YP_001000437.1, YP_001000562.1, YP_999817.1, and YP_999838.1) significantly reduced cecal Campylobacter loads by between 2 and 4.2 log10 CFU/g, with the concomitant development of a specific humoral immune response. In a second trial, cecal load reductions results were not statistically confirmed despite the induction of a strong immune response. These vaccine candidates need to be further investigated since they present promising features.

Novel Clinical Campylobacter jejuni Infection Models Based on Sensitization of Mice to Lipooligosaccharide, a Major Bacterial Factor Triggering Innate Immune Responses in Human Campylobacteriosis

“…Since the C. jejuni-induced immune responses in humans and chicken are very different, applying vaccines against C. jejuni to chickens could only reduce the Campylobacter transfer to humans. However, there are several studies using clinical strains such as C. jejuni 81-176 in chicken for vaccine development strategies [165,169].…”

“…Results from an in vivo study with Ross broiler chickens revealed four promising antigens (YP437, YP562, YP9817 and YP9838) as potential vaccine candidates against the C. jejuni 81-176 strain [169]. The identified proteins were either flagella-associated proteins or hypothetical proteins.…”

“…The administration of these antigens could reduce cecal C. jejuni loads by up to 4.2 log orders of magnitude in one trial. However, these promising results could not be reproduced, despite a strong induced immune response upon application of the same antigen [169]. In addition, recent investigations suggest C. jejuni N-glycan as a potential antigenic structure for vaccine development, since it constitutes a surface carbohydrate with immunogenic properties in rabbits and humans [170,171].…”

Current Status of <i>Campylobacter</i> Food Poisoning in Japan

“…Recently, new countermeasures to control Campylobacter colonization in the intestinal tracts of chickens have been reported, such as probiotics 52) , organic or inorganic acids as feed additives 53) , bacteriocin 54) , bacteriophages 55) and vacccines 56) . However, these have not been firmly established as prevention tools.…”

Field Interventions Against Colonization of Broilers by Campylobacter

“…Vaccination trials have thus far been limited to small-scale studies. Findings have been variable, although promising results have been reported in some recent cases (Meunier et al, 2017;Meunier, Guyard-Nicodème, Dory, & Chemaly, 2016). There is reasonable evidence that poultry can exert immunological control over Campylobacter colonization, from natural clearance of colonization (or of strains) in long-lived flocks, plus protective effects of prior exposure to Campylobacter spp., examination of specific immune responses, and effects of immunosuppression (Colles et al, 2015;de Zoete et al, 2007;Humphrey et al, 2014;Vaezirad et al, 2017).…”