phylogenetic study of haemonchus species from iran based on morpho-molecular characterization.

background : haemonchosis has a negative effect on the farming industry throughout the world, especially in the tropic and sub-tropic countries. the present study was carried out to differentiate haemonchus species from its main hosts in iran, including sheep, goat and camel.   methods: the identification took place based on the morphometrics of the spic-ules and molecular characters. two hundred seventy adult male nematodes were collected from the abomasums of different ruminants (90 samples from each ani-mal) at the slaughterhouses from different localities in iran. samples were morpho-logically identified according to the spicules’ morphometric measurements. in the section on molecular study, 10 samples of each haemonchus isolates were genetically examined. a simple pcr-restriction fragment length polymorphism (pcr-rflp) assay of the second internal transcribed spacer of ribosomal dna (its2-rdna) were described to confirm the pcr results. results: pcr-rflp profile obtained from the restriction enzyme hpa1 in h. con-tortus and h. longistipes indicated 1 (278 bp) and 2 (113 and 135 bp) different frag-ments, respectively. the morphological parameters clearly distinguish h. contortus from h. longistipes. moreover, regarding the its2-rdna, sequences of 295 bp and 314 bp were obtained from h. contortus and h. longistipes, respectively. conclusion: the genotypic results are in agreement with the phenotypic findings of both species.