Parasites in brains of wild rodents (Arvicolinae and Murinae) in the city of Leipzig, Germany

Abstract

Small rodents serve as intermediate or paratenic hosts for a variety of parasites and may participate in the transmission of these parasites into synanthropic cycles. Parasites with neuroinvasive stages, such as Toxoplasma gondii or Toxocara canis, can cause detrimental damage in the brain of intermediate or paratenic hosts. Therefore, the occurrence of neuroinvasive parasite stages was evaluated in brains of wild rodents captured in the city of Leipzig, Germany. In addition, a few specimens from the cities of Hanover, Germany, and Vienna, Austria were included, resulting in a total of 716 rodents collected between 2011 and 2016. Brains were investigated for parasitic stages by microscopic examination of native tissue, artificially digested tissue as well as Giemsa-stained digestion solution to verify positive results. Infective stages of zoonotic ascarids or other helminths were not detected in any sample, while coccidian cysts were found in 10.1% (95% CI: 7.9–12.5%; 72/716) of examined brains. The most abundant rodent species in the study was the bank vole (Myodes glareolus; Arvicolinae), showing an infection rate with cerebral cysts of 13.9% (95% CI: 11.0–17.8%; 62/445), while 2.7% (95% CI: 1.0–5.8%; 6/222) of yellow-necked mice (Apodemus flavicollis; Murinae) were infected. Generalized linear modelling revealed a statistically significant difference in prevalence between M. glareolus and A. flavicollis, significant local differences as well as an effect of increasing body mass on cyst prevalence. Coccidian cysts were differentiated by amplification of the 18S rRNA gene and subsequent sequencing. The majority of identifiable cysts (97.9%) were determined as Frenkelia glareoli, a coccidian species mainly circulating between M. glareolus as intermediate and buzzards (Buteo spp.) as definitive hosts. The zoonotic pathogen Toxoplasma gondii was confirmed in one M. glareolus originating from the city of Leipzig. Overall, it can be concluded that neuroinvasion of zoonotic parasites seems to be rare in M. glareolus and A. flavicollis.

<i>Toxoplasma gondii</i> infection in selected species of free-living animals in Poland

“…In Poland, there are no current data concerning T. gondii prevalence in wild, small rodents, thus the results of the present study can have new epidemiological value. T. gondii prevalence among rodents and insectivores (8.6% in mice, voles, common shrew and moles, and 6.3% in muskrats) in the current study showed moderate values; however, this is higher than the prevalence found in free-living rodents in the Czech Republic (1%) [28], and in yellow-necked mice in Germany (2.7%) [29]. The prevalence found in the current study in muskrats (6.3%) is lower than in the Czech Republic, where it ranged between 9-47% [30].…”

Seroprevalence of Toxoplasma gondii among Sylvatic Rodents in Poland

“…Wild rodents pose a particular threat for human communities because they constitute the most abundant and diversified group of all living mammals [7] and often adopt a synanthropic existence. Although some zoonotic parasites are not transmissible directly from rodents to humans, or pose just a low risk of direct transmission, predation of rodents by carnivore pets may cause infections in these animals, leading to subsequent contamination of households and other human-related environments [8,9].…”

Improving the detection ofA. cantonensisin brain tissues of mammalian hosts

“…We designed a timesaving, tissue-clearing digestion technique by adapting and optimizing several published protocols (Dubey, 1998b;Mayer-Scholl et al, 2017;Waindok et al, 2019) for other organ tissues. As helminths are sensitive to HCl (Dubey, 1998a), incubation times are key for retrieving non-damaged specimens, and why a shorter and non-destructive protocol was needed so to preserve worms' integrity for identifying characteristics (Dubey, 1998a(Dubey, , 1998b.…”