Investigating the vector competence of the house fly (Musca domestica) for Campylobacter jejuni

Campylobacteriosis is a severe gastroenteric disease in humans caused by the bacterium, Campylobacter jejuni, typically obtained through the ingestion of contaminated poultry products. Poultry facilities become contaminated through the introduction of pathogens, including C. jejuni, by the house fly, Musca domestica. This thesis investigates the vector competence of M. domestica for C. jejuni to determine if the bacteria survive house fly metamorphosis from larva to adult, and can multiply within adult flies to enhance transmission, and whether innate immune factors of the house fly can clear C. jejuni infections. We demonstrate that M. domestica mounts an effective innate immune response that prevents transmission of C. jejuni from larva to adult, and eliminates C. jejuni from adult house fly gastrointestinal tracts within hours. We propose that M. domestica serves as a mechanical vector, rather than as a true, amplifying, biological vector. These findings will help elucidate the elusive epidemiology of campylobacteriosis.