Phylogenetic study of Ostertagia species


Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran-Iran (Center of Excellent of Ecosystem and Ultrastructural changes of Helminthes)


BACKGROUND: Ostertagia  species are the main domestic ruminants abomasum worms, which cause parasitic gastritis. Parasitic gastritis is associated with disruption of the endocrine structure of abomasum, and influence the function and pH of abomasums. This can lead to weight loss, reduced milk and wool production with potentially mal-digestion of proteins. These cause the economic loss to animal husbandry industry. So, the national research priority in veterinary parasitology is identification of different native species of Ostertagia in Iran. OBJECTIVES: The main purpose of this study is identification and differentiation of Ostertagia species based on the molecular characterization. METHODS: During carcasses inspection at different abattoirs in Rey, Tehran, Mashhad and Bandar Abbas, 180 adult male worms of Ostertagia species from sheep and goat were collected. Morphological analysis was performed based on the morphometric characteristics of spicules. The ITS1, 5.8s and ITS2 ribosomal DNA was ampilified from individual worms by polymerase chain reaction (PCR) and then purified PCR product were sequenced and analyzed by Blast tool. RESULTS: 946 bp PCR products for all sequenced samples were compared with the released sequences of Ostertagia isolates available from GenBank and showed 2-3% differences and 97-98% similarity. CONCLUSIONS: The three species included in the present study are different in terms of molecular property (with 2-3% difference) and it is necessary to determine transmittance pattern and host affinity rules from each one to be used by program managers and evaluators for Prevention and Control programs.


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