The development of immunobiotechnology to prevent Enterococcus cecorum infections in poultry

From the beginning of 21st century, the previously known commensal of birds and mammals, Enterococcus cecorum (EC) has emerged as a major health concern with major economic impact in poultry industry. It is also an opportunistic pathogen and may cause disease in humans, chickens, and racing pigeons. Recently, this bacterium has appeared as a new threat for the poultry industry causing enterococcal spondylitis which was previously known as enterococcal vertebral osteoarthritis (EVOA) in chickens. It is a specified clinical syndrome infecting free thoracic vertebra and its adjacent notarium. The chronic inflammation due to compression of spinal cord led to hind limb paresis with variable severity and clinical signs such as lameness and arching of the back, birds sitting down on hocks, paralysis, and deaths. To date, there is very little information available about the immunopathology and pathogenicity of different strains of Enterococcus cecorum infecting poultry types. In addition, there is also lack of sufficient information regarding EC infection in laying hens and geese. The meat chicken’s relation to EC infection may be linked with genetic factors and anatomical features. To identify risk factors of EC disease outbreaks in poultry, certain studies are needed to be performed. Transovarian transmission and vertical transmission of pathogenic strains are needed to be demonstrated to fully identify the risk and virulence factors, genetic relation and age dependent causing of EC infections. Certain studies of epidemiological studies of molecular basis and whole genome sequencing has shown the existence of genotypic and genomic composition differences in isolates from spinal cord lesions and its commensal counterparts. Still there is no effective treatment available for EC infection. The antimicrobial therapies are not helpful after the onset of disease in chickens and symptoms appears. There is no vaccine available for this disease. The goal of this PhD project is to further refine previous attempts made in the Host Pathogen Interactions in livestock laboratory to generate an infection model using a field isolate of Enterococcus cecorum in chickens. Next, we will use phage biotechnology to understand the humoral immune response induced during infection in the latter model. As such we can use an approach called reverse vaccinology to not only understand and unravel the avian immune response or the shortcomings thereof during Ec infections. But, it will also allow to engineer immunobiotechnology to complement or steer this response toward preventing or controlling EC infections.