Vasily Nikolaevich Afonyushkin
Currently, a number of major poultry holdings have a problem with the formation of normal gut microbiota in chickens for a number of reasons, such as sterilization of feed, sealing of poultry houses, sanitation of water and thorough disinfection, combined with antibiotic therapy. All of these significantly limit the ability of chickens to transmit beneficial gut microbiota antagonistically active against enteropathogenic microorganisms to baby chickens.
On the other hand, the size of poultry farms, high density of broiler chickens, high density of poultry houses (these statements are also true for domestic pig farms), create conditions for the accumulation and spread of pathogenic viruses and bacteria. on this basis, there is a need to study the issues of formation of antagonistic-active intestinal microbiota, as it becomes the only way of further development of biosafety systems at large poultry and pig farming enterprises in the Russian Federation. Conversely, it seems obvious that the increasing number of E. coli strains in chickens and pigs increases the likelihood of the emergence of enterotoxigenic strains that are dangerous for humans as well. Intestinal infections caused by E. coli are widespread in animals and humans.
There are a large number of highly pathogenic forms of E. coli (enterotoxigenic strains, causative agents of hemolytic-uremic syndrome, etc.), however, the presence of E. coli strains with pathogenic properties in the intestinal microbiocenosis does not always lead to the development of an infectious process, and E. coli is normally found in the intestinal microbiocenosis. The study of the interaction of different strains of coliform bacteria with each other, including pathogenic forms, will make it possible to better predict the response of the intestinal microbiota to specific vaccines, bacteriophages and antibiotics, which will allow the development of the most effective medical and veterinary technologies aimed at controlling escherichiosis.
The results on the influence of the diversity of E. coli biotypes will allow us to predict the effectiveness of specific anti-epizootic measures against escherichiosis in large poultry and pig farms, to develop bacteriophage and vaccine preparations against escherichiosis (we have repeatedly observed that the use of vaccine and/or bacteriophage against E. coli was accompanied by a surge in mortality from colibacillosis).
The novelty of the project lies in the study of the hypothesis that a greater diversity of colicinotypes and biotypes of E. coli within the gastrointestinal microbiocoenosis of animals and birds limits the possibility of accumulation of enterotoxigenic strains, by reducing the maximum size of the ecological niche in the intestine for such a strain. Food competition and intraspecific antagonism due to colicins are likely to limit the maximum concentration of any E. coli strain within the intestinal microbiota, including highly toxigenic forms.