Phylogenesis of aerophila (Trichocephalida, ) from Different Hosts and Countries

D. Traversa1, M. S. Latrofa2, A. Di Cesare1, S. Meloni1, G. Castagna1, D. Otranto2 1 Department of Comparative Biomedical Sciences, University of Teramo, Italy; 2 Department of Public Health, University of Bari, Italy

Background: The globally distributed trichuroid parasitic affects the respiratory tract of different carnivore species and humans. Because the infection causes respiratory conditions of varying severity several aspects on the biology of this parasite need to be elucidated. In addition, given the absence of molecular information, the aim of this work was to characterise a genetic region of C. aerophila isolates from different hosts and countries towards further diagnostic and phylogenetic studies. Methods: Single adult from 9 red foxes (4 from Portugal, 3 from Romania and 1 from Serbia and UK, respectively), from 3 beech marten (from Portugal), and 5 egg batches from 3 dogs and 2 cats (from Italy) were subjected to a PCR-coupled sequencing protocol to amplify a ~ 344 bp informative region within the mitochondrial cox1 gene. The 17 C. aerophila sequences were undertaken to a phylogenetic analysis which was conducted by MEGA4 using the neighbour-joining tree-building method. Sequences were compared with cox1 sequences available in GenBankTM for the Nematoda belonging to the Capillarinae (n = 7) subfamily. Thelazia callipaeda was used as the outgroup. Results: No substantial differences were found in the C. aerophila sequences from single adult nematodes collected from wild and egg batches from domestic species. Furthermore, a very low rate of variation was found in the sequences obtained from different countries. These results were confirmed by phylogenetic analysis in that all sequences of C. aerophila were grouped into a single clade clustering with ones including those of Capillaria spp. available in GenBankTM. Conclusions: These preliminary results represent a foundation for further approaches to the study of lung capillariosis, e.g., validation of molecular tools instrumental to bio-epidemiological and diagnostic studies, and open avenues to address the phylo- geography and population-genetic make-up of this neglected lungworm and to investigate its taxonomic position within the phylum Nematoda.