Office for International Accreditation of Veterinary Education, Obihiro University of Agriculture and Veterinary Medicine帯広畜産大学獣医学教育国際認証推進室

Salmonella are classified into as many as 2,700 serovars according to the combination their somatic and flagellar antigens. Many of the pathogenic serovars cause diarrhea and other gastrointestinal symptoms in a variety of animals (food poisoning in humans). On the other hand, only a few serotypes (less than 10) cause septicemia in specific animals, leading to death. However, the mechanism that causes this strong host-specific virulence has not yet been elucidated. We have identified 50 antigens that are expressed by serovar Gallinarum (fowl typhoid) in infected chickens. We have also used mutant strains lacking the genes encoding these antigens to elucidate how these genes are involved in the pathogenesis of fowl typhoid, and been attempting to identify the genes essential for host-specific virulence and lethality and the mechanisms involved, compared with those of serovar Typhimurium, which has been commonly used in studies of Salmonella. We are also currently working on serovars Dublin and Abortusequi, which infects cattle and horses, respectively, and hope to eventually update our overall understanding of the pathogenicity of Salmonella spp.
Through this research, we hope to unravel the history of the co-evolution of pathogenic bacteria and their host animals, and furthermore, to elucidate how zoonotic pathogens have become able to infect various animal species, thereby contributing to the development of control measures for human and animal infectious diseases.

• Elucidation of pathogenic mechanisms of fowl typhoid/pullorum disease
• Epidemiological investigation of bovine salmonellosis and establishment of control strategies
• Elucidation of pathogenic mechanisms of equine paratyphoid