Mechanisms ofTritrichomonas foetusPathogenicity in Cats with Insights from Venereal Trichomonosis

Abstract

Almost 20 years has passed since trichomonosis was first recognized as a potential cause of diarrhea in domestic cats. Despite progress in confirming disease causation, developing means for diagnosis, and identifying approaches to treatment of the infection, we still know very little about how this parasite causes diarrhea. With increasing recognition of resistance of trichomonosis to treatment with 5‐nitroimidazole drugs, new treatment strategies based on an understanding of disease pathogenesis are needed. In this review, lessons learned from the pathogenesis of venereal trichomonosis in people and cattle are applied to clinical observations of trichomonosis in cats in effort to generate insight into areas where further research may be beneficial.

What is known about Tritrichomonas foetus infection in cats?

“…Because it is a recently described parasite, the pathogenesis of T. foetus infection in cats is still not fully understood (TOLBERT & GOOKIN, 2016). There are hypotheses on whether the parasite alone could cause clinical signs, or whether feline trichomonosis could be a multifactorial disease, associated with enteric coinfections and host-related factors (GOOKIN et al, 2004).…”

“…For example, diarrhea in these animals is usually slowed down with the administration of antibiotics (GOOKIN et al, 1999(GOOKIN et al, , 2001. If these antibiotics directly reduce the bacterial contribution in the pathogenesis of diarrhea or simply reduce the numbers of T. foetus by nutrient support depletion is unknown (TOLBERT & GOOKIN, 2016).…”

Prevalence of intestinal parasites in companion dogs with diarrhea in Beijing, China, and genetic characteristics of Giardia and Cryptosporidium species

“…However, P. hominis is generally considered nonpathogenic to humans (Gookin et al 2007;Meloni et al 2011). Tritrichomonas foetus is less common in dogs and not considered a human pathogen, although it may cause genitourinary infection in cattle and diarrhea in cats and dogs (Gookin et al 2005;Michi et al 2016;Tolbert and Gookin 2016). However, a rare case of T. foetus peritonitis was reported in an immunodeficient patient (Lacassin 2005), implying its potential to cause opportunistic infection in humans.…”

Fulminant Tritrichomonas foetus ‘feline genotype’ infection in a 3-month old kitten associated with viral co-infection

“…It is likely the host response to T. foetus was compromised, leading to increased numbers of T. foetus. Bovine T. foetus infections elicit a parasite-specific antibody response to adhesin and contact-dependent cytotoxicity, and these mechanisms may be hindered in immunosuppressed animals (Tolbert and Gookin, 2016;Voyich et al, 2001). Fluctuations in intestinal microbiota in the weaned kitten, influenced by co-infection of enteric pathogens, may have contributed to the trichomonad disease burden (Gookin et al, 2017;Šlapeta et al, 2015).…”