Evidence of the three main clonal Toxoplasma gondii lineages from wild mammalian carnivores in the UK.

Toxoplasma gondii is a zoonotic pathogen defined by three main clonal lineages (types I, II, III), of which type II is most common in Europe. Very few data exist on the prevalence and genotypes of T. gondii in the UK. Wildlife can act as sentinel species for T. gondii genotypes present in the environment, which may subsequently be transmitted to livestock and humans. DNA was extracted from tissue samples of wild British carnivores, including 99 ferrets, 83 red foxes, 70 polecats, 65 mink, 64 badgers and 9 stoats. Parasite DNA was detected using a nested ITS1 PCR specific for T. gondii, PCR positive samples were subsequently genotyped using five PCR-RFLP markers. Toxoplasma gondii DNA was detected within all these mammal species and prevalence varied from 6·0 to 44·4% depending on the host. PCR-RFLP genotyping identified type II as the predominant lineage, but type III and type I alleles were also identified. No atypical or mixed genotypes were identified within these animals. This study demonstrates the presence of alleles for all three clonal lineages with potential for transmission to cats and livestock. This is the first DNA-based study of T. gondii prevalence and genotypes across a broad range of wild British carnivores.