Prevalence of Toxoplasma gondii in small mammals from the Ardennes Region, France

Abstract

Abstract. Serum samples from 218 small mammals trapped in forest and grassland in the Ardennes region (North-eastern France) were tested for antibodies to Toxoplasma gondii. Using the modified agglutination test, positive results were found in 4/92 Apodemus sp., 3/64 Clethrionomys glareolus, 0/26 Microtus agrestis, 0/4 Micromys minutus, 3/5 Sorex sp., 2/9 Arvicola terrestris, and 7/18 Talpa europaea. Toxoplasma gondii was not isolated from the heart of seropositive individuals after bioassay in mice. Seroprevalence was significantly higher in large fossorial mammals living in grassland than in small forest mammals, probably related to ecological factors.Even if felids are the only hosts that can excrete oocysts in the environment, infection by the protozoan Toxoplasma gondii (Nicolle et Manceaux, 1908) is widely prevalent in numerous species of warm-blooded animals (Dubey and Beattie 1988). Ecological and behavioural factors like feeding behaviour or use of space (De Thoisy et al. 2003) as well as the differences in soil contamination can influence the level of infection of intermediate hosts. Species of small mammals living under the surface of the ground and/or feeding from the ground are thus expected to be in contact with T. gondii oocysts. We predicted that the prevalence of T. gondii should differ from one species of small mammals to another, according to differences in their behaviour (fossorial versus nonfossorial species) and habitat (forest versus grassland) leading to differences in their potential exposure to the parasite. Our aim was thus to explore the prevalence of T. gondii in several small mammal species, which differ in their behaviour, in forest and grassland areas where felids were present.Small mammals were trapped between October 2005 and October 2006 in the Ardennes region (North-eastern France) in two trapping sites: the 600-hectare Bel-Val private park (49°28'11"N, 5°02'13"E) composed by 80% of forest on one side, and the grassland surrounding the Boult-aux-Bois village (49°25'58"N, 4°50'57"E) on another side. Wildcats Felis silvestris silvestris (Schreber) and domestic cats Felis silvestris catus (L.) have been frequently observed in these two sites.A standardized trapping method was used in forest. Lines of 34 INRA live-traps were placed every three meters during three nights, and checked once a day (Spitz et al.

Prevalence of Toxoplasma gondii in common moles (Talpa europaea)

“…However, infection rates in our study (0–2.3%, depending on the testing method) were significantly lower than the prevalence in the French study, where 39% of the moles from North-Eastern France tested positive [20]. …”

Toxoplasma gondii in domestic and wild animals from forest fragments of the municipality of Natal, northeastern Brazil

“…In the wild environment, small mammals are considered staples in the diet of several species of wild felines and, possibly, the domestic cat (CAÑÓN-FRANCO et al, 2013). Some studies have shown that the rate of T. gondii infection in these felines is related to the predator-prey relationship, and therefore dependent on the availability of food for species considered to be prey (AFONSO et al, 2007). In the Parque da Cidade, there are no top-level predators, such as wild cats, so the population of domestic cats grows without interspecific competition.…”

Toxoplasma gondii and the Immunity-Related GTPase (IRG) resistance system in mice: a review

“…It is clear that in populated areas, especially those involved in agricultural practice, mice constitute by a large margin the most abundant intermediate host, but there is explicit evidence for extensive T. gondii infection in many other small wild mammals that are prey for domestic cats (Afonso et al 2007). In favour of the view that the mouse is subject to significant selective impact from T. gondii, it should also be noted that the mouse also suffers from two weaknesses following infection that appear to be associated with the adaptive strategy of T. gondii, namely the selective modification of its olfactory abreaction to cat urine in favour of a positive tendency to favour this smell (Vyas et al 2007), thus increasing the accessibility of infected mice to capture by cats; and the ability to transmit T. gondii vertically without significant injury to the progeny (Owen & Trees 1998), enabling persistence of the parasite in a mouse lineage or deme despite the short average lifetime of individual mice.…”