To study the pathogenesis of bacterial, viral and parasitic infectious agents, acting alone or in a mixed infection, as well as the impact of mycotoxins, we identify and characterise their virulence factors and their interaction with the host, peculiarly screening for the immune response. This facet of research includes:
Continuation of work on bacteria, for which CRIPA researchers have gained international recognition: Streptococcus suis (cause of septicaemias and meningitis in swine and zoonotic agent), Actinobacillus pleuropneumoniae (cause of porcine pleuropneumonia, a worldwide problem), Escherichia coli (of which certain strains are associated with major infections at all stages of production) and Salmonella, Listeria, Satphylococcus aureus which represent a challenge in both animal and human health, swine, eggs being recognized as a reservoir of strains with multiple antibiotic resistance.
Investigations of other pathogens – on which research is almost inexistent in Canada – causes of recent major economic losses: Haemophilus parasuis (cause of an emerging disease responsible for nursery death in North America) and Mycoplasma hyopneumoniae.
Analysis of the mechanisms underlying recurrent diseases, with special attention to diseases of viral origin, currently the most frequent among emerging diseases. Animals infected by viruses such as circovirus (involved in post-weaning multi-systemic wasting syndrome), influenza virus, PED and the porcine reproductive and respiratory syndrome are more vulnerable to most bacterial infections.
Parasites in swine and poultry health such as Eimeria, Cryptosporidium and Giarda, as well as emerging parasites : trichuris suis are analysed to identify virulence mechnisms, furhtermore, the complet genome sequencing of Eimeria strains infecting the candian herds is under process.
Impacts of mycotoxins, a food contaminant found in animal feed worldwide is studied under the scope of its interaction with viral and bacterial infections.
Line 1: Infectious agents
Line 2 : Diagnosis, molecular epidemiology and antimicrobial resistance and food safety
The emergence and re-emergence of swine and poultry viral diseases is increasing the urgency of developing new and rapid diagnostic tests (for circovirus, influenza H3N2). Priority will be given to molecular epidemiology as a research tool, in combination with antimicrobial resistance studies, for example.
Genetic characterization methods (e.g. PCR-RFLP) will be applied to the study of food pathogens in order to establish strategies for farm monitoring and controlling of pathogens such as Salmonella, Yersinia et Campylobacter.
New detection test for protozoan and mycotoxins are developed in order to improve the herd management. Impacts of biofilms will be analysed.
Moreover, the geographic distribution of infections, the various modes of their transmission, the factors controlling both aspects, will be studied as well as the host-pathogen-environment interactions (ecosystem). An epidemiologic approach will allow us to identify factors having an impact on the establishment or the severity of an infection. Thus, our researcher will determine optimal strategies and recommend on how to enhance the farm biosecurity to manage diseases related to antibiotic resistance or microbial contamination; to better control risks for the animal health and the veterinary public health.
Line 3 : Prophylactic anti-infectious measures: vaccines and other alternatives to antibiotic use
Vaccine development (already underway thanks to a grant from Valorisation Recherche Québec) will continue towards optimization of their components and vectored delivery systems: a non-toxigenic E. coli live vaccine (approval pending) and sub-unit vaccines against S. suis, Salmonella and Actinobacillus pleuropneumoniae. Finally, expertise acquired in the development of a genetic vaccine prototype against the bovine viral diarrhoea virus will be applied to swine pathogens. In addition, we wish to study injection-less vaccines, which are able to induce strong mucosal immunity.
Original and innovative alternatives to antibiotics, to actual pest mangement, such as adhesins, bacteriocins, chitosan, probiotics and others are currently in the process of evaluation. Also, we are focusing on new ways to devise antimicrobial and how the animal feed modulates the host immune answer as well as the intestinal microbiota. The final goal being to favor a beneficial bacterial flora to promote the swine ou poultry health and therefore the food safety.
At last, risk factors such as bioaerosols will be analysed in order to assess the impact of microorganisms contamination of the farm air, as well as the development of new control tools.