Marine Meunier
French Agency for Food, Environmental and Occupational Health & Safety, France
Title: Promising results in the assessment of new vaccine candidates against campylobacter in poultry
Biography
Biography: Marine Meunier
Abstract
Campylobacteriosis is the most prevalent human bacterial gastrointestinal disease in Europe. Birds are the main reservoir of Campylobacter and human contaminations principally occur by consumption and handling of poultry meat. It was estimated that a Campylobacter reduction from 2 to 3 log10 CFU/g of the intestinal contents in live broilers could be responsible for a decrease of 76% to 100% of the infection in humans. Vaccination of poultry could be a potential way in this goal but despite many studies, no efficient vaccine is available yet and research of more powerful vaccine antigens against Campylobacter is needed. The recent in silico analysis of Campylobacter genome using the reverse volcanology strategy allowed the identification of 14 potential new vaccine candidates. After developing an avian vaccine protocol consisting in two immunizations by the intramuscular route on day five with DNA and day 12 with proteins followed by an oral challenge on day 19, we assessed in vivo immune and protective powers of six new vaccine candidates, individually or in combination. Among the six antigens, four had a significant effect on both IgY production in serum and reduction of Campylobacter caecal counts. The mean reduction of caecal counts with those four proteins varied from 2 to 4.2 log10 CFU/g of caecal content. The pooled proteins had no protective effect. A new in vivo experiment is actually on going in order to confirm these results. The first results are promising since they reach reductions better than those estimated to impact human diseases incidence. Also these results proved the interest of the reverse vaccinology approach to screen new candidate proteins that may become efficient vaccines.
