Molecular analysis of isolates of the cestode Rodentolepis nana from the great gerbil, Rhombomys opimus.

Rodentolepis nana (syn. Hymenolepis nana) is a cyclophyllidean zoonotic enteric parasite with worldwide distribution. In humans, it is more prevalent in children, especially in temperate zones. A morphologically similar species of R. nana occurs in different rodents, including gerbils. In the present study molecular characterization of five isolates of R. nana from Rhombomys opimus in the Golestan Province (n= 2) and Razavi Khorasan Province (n= 3), both in north-eastern Iran, were analysed. After DNA extraction, the internal transcribed spacer 2 (ITS2) region of the R. nana isolates was amplified and sequenced, and genetic variation was analysed. Accordingly, two isolates from the Razavi Khorasan Province showed ITS2 signatures that differed from the isolates from the Golestan Province. The third isolate from Razavi Khorasan did not reveal these specific signatures, but exhibited sparse nucleotide polymorphisms in the ITS2 sequence. The ITS gene is conserved, and variation in this fragment could be an interesting subject for further inspection of existing variation in the genome of R. nana, among different domestic and wildlife host species and from different areas.

Helminth Parasites of Rhombomys opimus from Golestan Province, Northeast Iran.

BACKGROUND: The aim of the study was to determine the helminthic species occurring in great gerbil Rhombomys opimus collected from Maraveh Tappeh, Golestan Province, northeast Iran. METHODS: During 2010-2011, a total of 77 R. opimus were captured from rural areas of Maraveh Tappeh, Golestan Province, using Sherman live traps and examined for infectivity with any larva or adult stages of helminthic parasites. RESULTS: Overall, 63 R. opimus (81.8%) were found infected with different helminthic species. The rate of infectivity with each species was as follows: Trichuris rhombomidis 31.2%, Trichuris muris 32.5%, Trichuris spp. 10.4%, Syphacia muris 2.6%, Dipetalonema viteae (Acanthocheilonema viteae) 37.7%, Skrjabinotaenia lobata 15.6%, Hymenolepis (=Rodentolepis) nana fraterna 5.2%, and Taenia endothoracicus larva 1.3%. CONCLUSION: R. opimus is host for several species of cestodes and nematodes in the study area. The high rate of infectivity with D. viteae indicates the susceptibility of these gerbils to this filarial nematode. Synchronous infections occurred up to four species of helminthes in one host.