PCR-based identification and delineation of members within the Pseudorhabdosynochus lantauensis complex (Monogenea: Diplectanidae)

A new species of diplectanid (Monogenoidea) from Paranthias colonus (Perciformes, Serranidae) off Peru

Pseudorhabdosynochus jeanloui n. sp. (Monogenoidea, Diplectanidae) is described from specimens collected from the gills of the Pacific creolefish, Paranthias colonus (Perciformes, Serranidae) from a fish market in Chorrillos, Lima, Peru. The new species is differentiated from other members of the genus by the structure of its sclerotized vagina, which has two spherical chambers of similar diameter. This is the first Pseudorhabdosynochus species described from the Pacific coast of America, the third species of the genus reported from South America and the first described from a member of Paranthias.

Molecular characterization of hard and soft ticks from Romania by sequences of the internal transcribed spacers of ribosomal DNA

In the present study, four hard tick species and one soft tick species, namely, Dermacentor marginatus, Haemaphysalis punctata, Haemaphysalis parva, Ixodes ricinus, and Dermanyssus gallinae, from south-western Romania were characterized genetically by the first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA), using a hard tick, Haemaphysalis longicornis, from China for comparative purposes. The ITS rDNA was amplified by polymerase chain reaction (PCR) and sequenced from individual ticks. The lengths of the ITS-1 sequences were 238-1819 bp, and the lengths of ITS-2 were 137-1695 bp, respectively, for all ticks sequenced. While sequence variation within a hard tick species was 0-1.5%, nucleotide differences between hard tick species ranged 2-25.2%, indicating that ITS rDNA sequences provide genetic markers for the differentiation of hard ticks from Romania. Hence, a PCR-linked restriction fragment length polymorphism approach was developed for their unequivocal differentiation based on ITS-1 rDNA. This is the first characterization of ticks from Romania using a genetic approach, which provides the foundation for further studies on ticks in Romania and has implications for studying the population genetic structure of the Romanian ticks and for identification and differentiation of closely related ticks.

The occurrence of Toxocara malaysiensis in cats in China, confirmed by sequence-based analyses of ribosomal DNA

Non-isotopic polymerase chain reaction (PCR)-based single-strand conformation polymorphism and sequence analyses of the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) were utilized to genetically characterise ascaridoids from dogs and cats from China by comparison with those from other countries. The study showed that Toxocara canis, Toxocara cati, and Toxascaris leonina from China were genetically the same as those from other geographical origins. Specimens from cats from Guangzhou, China, which were morphologically consistent with Toxocara malaysiensis, were the same genetically as those from Malaysia, with the exception of a polymorphism in the ITS-2 but no unequivocal sequence difference. This is the first report of T. malaysiensis in cats outside of Malaysia (from where it was originally described), supporting the proposal that this species has a broader geographical distribution. The molecular approach employed provides a powerful tool for elucidating the biology, epidemiology, and zoonotic significance of T. malaysiensis.