Identification of Toxoplasma gondii in wild rodents in Poland by molecular and serological techniques

Rodents are recognized as reservoirs for Toxoplasma gondii, playing a crucial role in maintaining the parasite's presence in the environment. Biomonitoring was conducted to assess the role of sylvatic rodents in maintaining T. gondii, and to analyse the prevalence and seroprevalence of the parasite in seven wild rodent species. Rodents were collected in an open grassland study site located in northeastern Poland, and dissected. Brain, spleen, blood and serum samples were collected. Molecular (PCR assay, nested-PCR assay) and serological (ELISA and agglutination tests) methods were applied to indicate the best approach for application in the biomonitoring of T. gondii in small mammals. Samples were screened from 68 individuals using PCR assays but no T. gondii DNA were found. The agglutination test showed no signal. Antibodies against T. gondii were found in 5 sera samples out of 56 analysed (seroprevalence = 8.9% [4.4-16.8]). The results confirmed that rodents participate in the life cycle of T. gondii as reservoirs of this parasite in the sylvatic environment. However, for effective bio-monitoring of T. gondii in small mammals, the results suggest a preference for utilizing ELISA tests to detect T. gondii antigens, as opposed to relying solely on molecular methods.