Rodents Helminth Parasites in Different Region of Iran.

BACKGROUND: Climate condition is expected to have significant in rodents' diversity and in the seasonal pattern of diseases carried by different rodents. In an effort to aid in the study of the biodiversity of parasites of rodents in different climate zoon we examined climate patterns in the parasite assemblages of different rodents from Mar 2015 to Feb 2016. METHODS: Of 253 captured rodents in three climate zone of Iran, thirteen species of rodents were recognized. Rodents included Mus musculus, Microtus, Apodemus witherbyi, Calomyscus elburzensis, Meriones libycus, Tatera indica, Alactaga elater, and Arvicola amphibius. Trapped rodents humanely sacrificed and the gastrointestinal and respiratory tracts were removed and examined to identify parasitic helminths. Parasites were identified using key morphological characteristics. RESULTS: Of 253 rodents examined, 109 (43.08%) were positive for helminth infection including Syphacia obvelata (20.1%), Aspicularis tetraptera (9.9%), Trichuris muris (0.3%), Capillaria sp. (0.3%), Physaloptera sp. (0.7%), Gongylonema sp. (1.1%), Nippostrongylus brasiliensis (6.7%) Heligmosomoides polygyrus (4.3%) Hymenolepis diminuta (3.1%), H. nana (0.8%), Cysticercus fasciolaris, (2.7%), Mesocestoides sp. larva (0.3%) and Moniliformis moniliformis (0.3%). Notocotylus neyrai was the only species of Trematoda isolated from water vole (Arvicola amphibius) for the first time in Iran. CONCLUSION: Some rodents are omnivorous, showing high predisposition to helminths parasites consequently, they harbor some species of parasites which are potentially zoonotic or may serve as vectors of important zoonotic pathogens. Therefore, the potential health hazard of these species needs to be considered to prevent infectivity of humans.

The Effect of Marshallagia marshalli on Serum Gastrin Concentrations in Experimentally Infected Lambs.

: Because there appeared to be no data available on serum gastrin concentrations in animals infected with Marshallagia marshalli, and considering the high prevalence of this parasite in livestock throughout many countries, we decided to perform research in the field using experimental infection. After surgical implantation of abomasal cannula into 10 male Baluchi sheep, each animal was orally infected with 5,000 M. marshalli larvae. Serum gastrin concentrations and abomasal pH were measured with a human ELISA kit and a PHM LE438 standard pH electrode, respectively. According to the results obtained from the study, serum gastrin increased after 14 and 21 days post-infection (dpi), while abomasal pH increased after 7 dpi and reached a maximal value 16 dpi. The increase in serum gastrin concentration was revealed 6 days after elevation in abomasal pH, which could be the result of reduced acid secretion. Generally, the present study pointed out that a limited number of M. marshalli could increase serum gastrin concentrations.

Comparison of two methods of Marshallagia marshalli donor sheep production.

Marshallagia marshalli is found in the abomasums of sheep, goats and wild ruminants in tropical and sub tropical climates. In Iran among different species of Ostertagiinae that can infect sheep, M. marshalli is currently the major cause of parasitic gastroenteritis in ruminant. Having a donor animal is essential for various studies. In the present study we compared the efficacy of two different method of M. marshalli donor sheep production. In the first method, M. marshalli donor sheep was produced by transplanting of adult forms of this worm into abomasum of a lamb (6 months of age) through a surgically established cannula. In the second method, 5,000 infective larvae (L3) from the female M. marshalli culture were given to a worm-free lamb of 6 months age through a stomach tube. After 3 days of transplanting, few eggs of M. marshalli appeared in the cannulated lamb's faeces. The number of eggs per gram of faeces (EPG) increased in the following days. The average number of EPG reached up to 23.5 ± 11.26 per day in 2 months. In larval infected lamb by day 21 post infection the eggs were appeared in faeces. The average number of EPG reached up 53.5 ± 42.5 per day in 2 months. In comparison between cannulation and larval infected, the number of eggs laid by worms transplanted in cannulated lamb was less than that of larval infected lamb. However, the abomasal cannulation method seems more preferable due to some advantages such as defined number of worms transplanted into abomasums, rapid access to the eggs and their culture.

Pathophysiology of Marshallagia marshalli in experimentally infected lambs.

Species of Marshallagia are abomasal parasites in free-ranging and domesticated ungulates in temperate climatic zones throughout the world. Pervasiveness of these nematodes is significant in various parts of the world. There has been limited research in the area of Marshallagi amarshalli pathogenesis. The aim of this study was to investigate the effects of M. marshalli on the acid secretory capacity of the abomasal mucosa and the morphological changes due to parasitic migration to different parts of abomasal tissue in sheep. Ten lambs, approximately around 6 months old, were allotted to two groups of five (A and B). The sheep from group A were infected orally with a dose of 5000 third-stage larvae (L3) of M. marshalli whereas the sheep of group B were not infected. The results indicated that the development of M. marshalli in the abomasal glands of ruminants causes pathophysiological changes, which include a reduced acidity of the abomasal contents, increased abomasal pH and increased serum pepsinogen concentrations. The reduced acid secretion is explained by a replacement of functional parietal cells by undifferentiated cells. Histology changes include mucosal cell hyperplasia, loss of parietal cells and inflammatory cell infiltration, which includes numerous granulocytes and lymphocytes.