Species diversity of dermal microfilariae of the genus Cercopithifilaria infesting dogs in the Mediterranean region

Following the recent description of microfilariae of a Cercopithifilaria sp. in a dog from Sicily, Italy, (herein after referred to as Cercopithifilaria sp. I), numerous skin samples were collected from dogs in the Mediterranean region. In addition to Cercopithifilaria sp. I (185·7±7·2 μm long), microfilariae of 2 other species were identified, namely Cercopithifilaria grassii (651·7±23·6 μm long) and a yet undescribed microfilaria, Cercopithifilaria sp. II (264·4±20·2 μm long, with evident lateral alae). The morphological differentiation among the 3 species of dermal microfilariae was confirmed by differences in cytochrome c oxidase subunit 1 and ribosomal 12S sequences examined (mean level of interspecific pairwise distance of 11·4%, and 17·7%, respectively). Phylogenetic analyses were concordant in clustering these with other sequences of Cercopithifilaria spp. to the exclusion of Dirofilaria spp., Onchocerca spp. and Acanthocheilonema spp. Dermal microfilariae collected (n=132) were morphologically identified as Cercopithifilaria sp. I (n=108, 81·8%), Cercopithifilaria sp. II (n=17, 12·9%), whereas only 7 (5·3%) were identified as C. grassii. Mixed infestations were detected in all sites examined. The great diversity of these neglected filarioids in dogs is of biological interest, considering the complex interactions occurring among hosts, ticks and Cercopithifilaria spp. in different environments.