Detection and genotyping of Toxoplasma gondii in wild canids in Serbia

To gain insight into the population structure of the protozoan parasite Toxoplasma gondii in wildlife in Serbia, multiplex nested PCR- RFLP was performed on T. gondii DNA positive samples of heart tissue of three wild canid species, including red foxes (Vulpes vulpes), golden jackals (Canis aureus) and grey wolves (Canis lupus). Out of 110 samples (28 red foxes, 72 golden jackals, 10 wolves), 30 (27.3%) were positive for T. gondii DNA, of which 24 were genotyped (nine red foxes, 13 golden jackals and two wolves). The results showed a large dominance of lineage II (n = 20, 83.4%) over lineage III (n = 4, 16.7%) strains. Lineage II comprised four archetypes, 14 variants and one which remained undetermined, while within lineage III there were three archetypes and one variant strain. However, a notable difference in diversity was observed among the examined canids, with eight (88.9%) of the nine strains detected in red foxes distinct, vs. six (46.1%) distinct strains of the 13 detected in golden jackals. Since anthropogenic food sources are a major reservoir of archetypal lineage II and III T. gondii strains, the results suggest that the golden jackal may be outcompeting the red fox, forcing it to hunt wild mammals and birds for sustenance, thereby increasing its chances of infection with variant strains. In addition to presenting the first data on the T. gondii population structure in wild canids in Serbia, this is the first report ever on T. gondii genotypes in golden jackals, a species with an increasing presence in Europe and another important reservoir of domestically circulating T. gondii strains.