فهرست مطالب ehsan rakhshandehroo

In this study, the digestive tracts of the Caspian turtles (Mauremys caspica) were investigated for the presence of helminth infections. Specimens of roundworms were recovered from the large intestine and stomach of the Caspian turtles. The morphologic measures revealed the infection with nematodes of the genus Falcaustra and Spiroxys. However, some differences were found in the collected Falcaustra specimens compared to the previous descriptions. In parallel, samples were analyzed by sequencing of the ribosomal gene targets. The phylogenetic analysis showed that the Falcaustra species as members of superfamily Cosmocercoidea were grouped with some members of Ascaridoidea and Spiruroidea. Despite the significant morphologic differences, Spiroxys species formed a sister group with ascaroid and cosmocercoid roundworms. Therefore, our molecular findings revealed that the taxonomic position of both nematodes need be revised.

In this study, the anthelmintic effects of the medicinal herb, Nigella Sativa L., was screened in vitro against the infective larvae of Parascaris equorum. Follow the collection of Parascaris worms, the egg content were depleted and hatched using sodium hypochlorite solution. The recovered larvae of the parasite were exposed to six concentrations (6.25, 12.5, 25, 50, 100 and 200 mg/mL) of the Nigella extract and then examined for the viability at 0, 10, 20, 30, 40, 50 and 60 minutes after the challenge. The results revealed that the concentration of 6.25 mg/mL had not any significant anthelmintic effects on P. equorum larvae. In contrast, the statistics indicated that all the higher concentrations of the Nigella extract remarkably reduced the viability of larva. These results were obvious during the first ten minutes of the experiment. With increase in time of exposure, the mortality effect of the extract elevated significantly. In addition, all larvae were inactivated after 40, 20 and 10 minutes after exposure at the concentrations of 50, 100 and 200 mg/ml, respectively. These results confirmed that this herbal extract possess good antiparasitic effects against P. equorum infections.

The green toad, Bufo variabilis has been a common species of toads in Iran with a wide distribution in most provinces. The main goal of this study was to determine the helminth parasite fauna of B. variabilis in southwest of Iran. Among 30 toads inspected for helminth infection from different sites, 100% harbored one or more parasite species. Some toads were afflicted by intestinal obstruction, due to the infection with a large number of cestodes. Twenty-eight cases (93%) had mixed infection with cestodes (in intestine) and nematodes (in lung). Also, a toad was infected with a single monogenean parasite in its urinary bladder. The identified helminth parasites were monogenean, Polystoma viridis; cestode, Nematotaenia dispar and a species of nematode, Rhabdias ranae. This study reports for the first time the presence of nematode species R. ranae in B. variabilis in Iran.