Detection of European Trichobilharzia schistosomes ( T. franki , T. szidati , and T. regenti ) based on novel genome sequences

Abstract

The most frequent causative agents of cercarial dermatitis in Europe are the avian schistosomes of the genus Trichobilharzia . They preferably parasitize birds of the Anatidae. Trichobilharzia spp. schistosomes are also able to penetrate mammalian skin, posing a health risk to mammals, including humans. Currently several loci from nuclear and mitochondrial genomes are determined for European species of Trichobilharzia . Among them there is 1 genome sequence, ToSau3A, which is suitable for detection of Trichobilharzia spp. infection in aquatic systems. In the present paper, we used a PCR assay to obtain novel genome sequences from cercariae isolates of 3 European bird schistosome species ( Trichobilharzia franki , Trichobilharzia szidati , and Trichobilharzia regenti ) collected from freshwater ponds in Belorussia and Russia. We applied RAPD-fingerprinting using 1 random primer to differentiate 3 trichobilharzian species and subsequently cloned and sequenced putative species-specific RAPD fragments. One of them (410 bp in length), which was obtained for T. franki , revealed 64% homology with the repeat region of Schistosoma mansoni (GenBank FN357352) and turned out to be suitable for designing a specific primer pair (TR98F and TR98R) to detect 7 novel DNA sequences in the genome of 3 European Trichobilharzia species. The newly designed primer pair was found to be potentially suitable for PCR-based detection of trichobilharzian infection in snails. PCR primers TR98F and TR98R amplified only the DNA isolated from cercariae and sporocysts of 3 trichobilharzian species, but neither the DNA of 3 other digenean species ( Bilharziella polonica , Apatemon sp., and Diplostomum sp.) nor the DNA of uninfected host snails ( Lymnaea stagnalis , Radix auricularia , and Radix ovata ).