Submitted to: American Journal of Tropical Medicine and Hygiene
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 9, 2003
Publication Date: August 25, 2003
Citation: Mansfield, L., Gauthier, D., Abner, S., Jones, K., Wilder, S., Urban Jr, J.F. 2003. Enhancement of disease and pathology by synergy of trichuris suis and campylobacter jejuni in the colon of immunologically naive swine. American Journal of Tropical Medicine and Hygiene 68(1):70-80 (2003)
Interpretive Summary: Immunity to nematode parasites is characterized by an immediate type hypersensitivity reaction that can expel worms from the intestine without dramatic effects on the equilibrium of the host. There are consequences to this reaction, however, that may result in interference with immunity to bacterial, viral and protozoan infections. This is because the nature of the immune response to worm versus bugs is different, and these responses often counter regulate the efficiency of the other. This concept of counter regulation and consequences of mixed infections with worms and bacteria was demonstrated by treating new born pigs with an immature immune system with whip worms and bacteria. Campylobacter bacteria are common and can cause severe diarrhea when inadvertently ingested in contaminated foods. The study shows that the combined exposure exacerbates the bacterial infection and causes disease in the piglets that is more severe than when each infection is given alone. This study will have impact on strategies to control worm infection by therapy or management in both livestock and humans, and can make the treatment of campylobacter infection more efficient. Scientists and clinicians interested in these infectious agents and control of disease severity will benefit from this information.
Campylobacter jejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on C. jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections like Trichuris, which drive type 2 cytokine reponses and downregulate type 1 immune responses. Here, 3-day-old germ-free pigs given dual infections with Trichuris suis and C. jejuni had more frequent, more severe diarrhea and severe pathology than pigs given no pathogens, T. suis alone or C. jejuni alone. These pigs had significant hemorrhage and inflammatory cell infiltrates in the proximal colon where L4 larvae were found, and abscessed lymphoglandular complexes in the distal colon with intracellular C. jejuni. Pigs given C. jejuni alone had mild clinical signs and pathology, and bacteria in feces or extracellular sites. Pigs given T. suis or no pathogens had no disease and minimal pathology. Thus, these agents synergized to produce significant disease and pathology, which was site specific