Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany

PLoS One. 2017 Mar 9;12(3):e0172829. doi: 10.1371/journal.pone.0172829. eCollection 2017.

Abstract

Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health risks arising from wild and domesticated carnivores.

MeSH terms

  • Animals
  • Antibodies / blood
  • Antibodies / immunology
  • Antigens, Protozoan / immunology
  • Arvicolinae / parasitology
  • Berlin
  • Brain / parasitology
  • Cats
  • Cluster Analysis
  • Dogs
  • Eucoccidiida / genetics
  • Eucoccidiida / isolation & purification
  • Germany / epidemiology
  • Host-Parasite Interactions*
  • Mesocestoides / genetics
  • Mesocestoides / isolation & purification
  • Muscle, Skeletal / parasitology
  • Parasitic Diseases, Animal / epidemiology
  • Parasitic Diseases, Animal / parasitology*
  • Polymerase Chain Reaction
  • RNA, Ribosomal / metabolism
  • Rodentia / parasitology*
  • Taenia / genetics
  • Taenia / isolation & purification
  • Toxoplasma / genetics
  • Toxoplasma / isolation & purification

Substances

  • Antibodies
  • Antigens, Protozoan
  • RNA, Ribosomal
  • RNA, ribosomal, 12S

Grants and funding

The funder Bayer Animal Health, Leverkusen, Germany provided financial support to the Freie Universität Berlin to pay a stipend for one author [JB] and research materials, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. RS is employed by Bayer Animal Health and participated in the conceptualization of the study and supported the study by facilitating the financial support through Bayer Animal Health. He did not have any influence on the conduct of the study, the data collection and analysis and the decision to publish. The specific roles of these authors are articulated in the ‘author contributions’ section.