Are Toxoplasma gondii infected water voles (Arvicola amphibius s.l.) easy prey for cats?

PARDO GIL, M.; HEGGLIN, D.; BRINER, T.; MÜLLER, N.; MORÉ, G.; FREY, C.F.; BASSO, W. U.

Bern

Encuentro; 6th International Meeting on Apicomplexan Parasites in Farm Animals (Apicowplexa 2022); 2022

The obligate intracellular protozoan parasite Toxoplasma gondii is the cause of one of the most common parasitic infections on earth. There is evidence suggesting that T. gondii may manipulate the behavior of its rodent host to enhance transmission to its definitive feline host, thereby ensuring completion of its life cycle. The aim of this study was to test this hypothesis in the natural environment, given that most studies have been performed with hosts maintained under laboratory conditions. For this purpose, we analysed cat-hunted (n=82) and trap-captured (n=49) rodents of the species Arvicola amphibius s.l. (Syn. A. terrestris, A. scherman) sampled throughout Switzerland. Brain and skeletal muscle samples from each rodent were tested for T. gondii DNA, and positive samples were further genotyped using a multilocus nested-PCR-RFLP approach including 11 T. gondii genetic markers. All amplified markers were sequenced and subjected to in silico RFLP- analysis to enhance the discriminatory power of the method. The prevalence of T. gondii DNA in cat-hunted rodents was 11.1 % (7/63) whereas no animal was infected among the 49 trap-captured individuals (0%; Fisher's exact test: p = 0.0176). Nevertheless, these results should be considered with caution given the limited number of samples available and the many factors at play in the natural environment, involving both predators and prey. All detected T. gondii parasites, which could be completely genotyped, exhibited the ToxoDB #3 genotype, a Type II variant. The present data reveal the forthcoming need to further test this hypothesis in the natural environment and on different host species.