A tick survey was carried out in four different geographical areas of Iran, where the majority of the domestic ruminants in Iran exist. About 1,500 sheep, 1,200 goats and 500 cattle of 12 herds in different provinces lying in the corresponding zones were inspected for tick infestation. The occurrence of ticks on cattle, sheep and goats were 62, 55 and 57%, respectively, with no differences between the zones. The mean number of ticks on each animal was low (10-20 ticks per animal). Ixodid ticks were found throughout the year, whereas the soft tick Ornithodoros sp., which occurred in mountainous area with a significant difference in abundance, showed a clear pattern of seasonality, being generally present from November to March. The largest numbers of adult ixodid ticks were generally present from April to August. Rhipicephalus, Haemaphysalis and Dermacentor ticks occurred in the mountainous area, whereas Boophilus and Ixodes ticks were only present in the Caspian region. Hyalomma were very abundant in each zone but especially in the mountainous area, whereas Ixodes ticks were the minor genus.

Abstract:The geographical distribution and ecological preferences of Haemaphysalis in domestic animals in Iran were studied 4 times a year from April 2003 to March 2005. A total of 1,622 ixodid tick specimens were collected from 3 different zones. Among them, 108 (6.7%) Haemaphysalis ticks, consisting of 6 species, were identified; H. punctata (3.4%), H. parva (0.5%), H. sulcata (0.6%), H. choldokovskyi (1.7%), H. concinna (0.06%) and Haemaphysalis sp. (0.6%). H. punctata was the most abundant species, whereas H. concinna was the rarest species collected in humid and sub-humid zones on cattle, sheep and goats. H. choldokovskyi was principally collected from sheep and goats grazed in cold mountainous areas. The infested areas consisted of Caspian Sea (Guilan, Mazandaran, Golestan, and central provinces), mountainous (Azarbaiejan, Ardebil, Kohgilouyeh, and Kordestan) and semi-dessert (Khorasan, Semnan, Kerman, Sistan, and Baluchestan) zones. The Caspian Sea zone (23.6%) was the most highly infested region. The results show that various species of Haemaphysalis ticks infest domestic ruminants in Iran and each tick species show characteristic geographical distributions.

One species of Babesia was identified on the blood smear of 20 different naturally infected sheep in the Northwest of Iran. It was polymorphic, including double pyriform with acute or obtuse angle, single pyriform, and ring form. The size of typical paired pyriforms with acute angle was 2.7 x 0.4 microm (n=10) and with obtuse angle was 3.5 x 0.6 microm (n=10). Although the morphological and biometrical parameters resembled the Babesia motasi, the results of seminested polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism using primers specific for small subunit of 18S rRNA confirmed this species as Babesia ovis. Furthermore, the sequence analysis of hypervariable region of small subunit of 18S rRNA revealed the corresponding sequences for B. ovis as well. Experimental infection of healthy lambs with the morphological larger B. ovis showed a milder clinical signs compared to the small one.

Ticks are hematophagous arthropods transmitting several harmful human and animal pathogens like viruses, Rickettsia, bacteria, and protozoa. The identification and speciation of ticks were normally performed in Iran using identification key of Arthur (1960) and Kaiser and Hoogstraal (J Parasitol 49:130-139, 1963) or on the basis of morphological characteristic keys recommended by Walker et al. (2003). Although these identification keys are well prepared, but there are in some cases due to the strong overlapping characteristics between species like Dermacentor marginatus and Dermacentor niveus accompanied with serious problems. D. marginatus and D. niveus have been intermittently used synonymously and there is no a generally agreement with the specification of these species. To find out more about these two species, we have analyzed the complete nucleotide sequence of ITS-2 region. Interestingly, we found indeed a sequence homology of 99% between nucleotide sequence of ITS-2 region of D. marginatus and D. niveus. Since the nucleotide sequence of ITS-2 region of D. marginatus in Iran has 98% sequence homology to the other in GenBank registered ITS-2 sequence of D. marginatus, and the morphological characteristics between both examined species showed minimal differences, therefore we believe that the D. marginatus and D. niveus could belong to the same species and 1% differences in nucleotide sequence of ITS-2 region between these two species can be understand as an intra-species polymorphism.

The tick-borne diseases of livestock constitute a complex of several diseases with different etiological agents, such as protozoa, rickettsia, bacteria, and viruses. One problem discussed in protozoan infection is the determination and characterization of the transmitter agent. Because many analyses were performed with the salivary gland smears using the methyl-green-pyronin staining method or the Feulgen staining method, the transfer vector remains unanswered in some cases. The aim of this study is to recognize Babesia ovis in the salivary gland of Rhipicephalus spp. using polymerase chain reaction (PCR). Deoxyribonucleic acid (DNA) was isolated from 269 salivary gland of Rhipicephalus spp. (108 R. bursa, 87 R. turanicus, 74 R. sanguineus) collected from sheep with suspected to babesiosis. The isolated DNA was then analyzed with the primers derived from the hypervariable region V4 of 18S ribosomal ribonucleic acid (rRNA) of the Babesia species. For the specificity of the PCR product and discriminating from Babesia motasi and Babesia crassa, nested PCR and restriction fragment length polymorphism was performed. As positive control for the DNA extraction procedure, the DNA was analyzed with the common primers designed from the 18S rRNA of the Ticks (Rhipicephalus, Hyalomma, Haemophysalis, Dermacentor, Ixodes, Boophilus). B. ovis was detected in salivary gland of 18.5% R. bursa, 9.1% R .turanicus, and 8.1% R. sanguineus, respectively.

The distribution of Hyalomma species on domestic animals was studied in four zoogeoghraphical zones. Nine hundred and ninety-two Hyalomma ticks were collected from sheep, goats, cattle and camels. A total of seven tick species consisting of: Hyalomma anatolicum Koch, 1844 (28.93%), H. excavatum Koch, 1844 (12.5%), H. asiaticum Schulze & Schlottke, 1930 (13.5%), H. marginatum Koch, 1844 (27.01%), H. detritum Schulze, 1919 (9.67%), H. schulzei Olenev, 1931 (4.03%) and H. dromedary Koch, 1844 (4.33%) were recorded. The results indicated that H. anatolicum, H. asiaticum, H. marginatum and H. detritum were present in all zones whereas H. excavatum was absent in Zone I. The result also showed that H. dromedari was presented in Zones III and IV whereas H. schulzei was present in Zones II and III. During this study, the tick species collected are candidates for investigation as vectors of pathogenic organisms in Iran.

Sarcoptes scabiei infestation was diagnosed in 278 sheep from 12 fatling flocks. The sheep presented crusted skin lesions initially appear on the lips or nostrils, the lesion on nostrils also extend towards around the eyes, the supraorbital fossae and in some cases over entire face. The infested male lambs by mating behavior in fatling flocks caused transmitting the infection to fat tail area and scrotum. Histopathological study of lesions demonstrated marked acanthosis, hyperkeratosis, parakeratosis. Tunnels could be observed in the hyperkeratotic stratum corneum and mite segments were located mainly in the stratum corneum and also in the stratum granulosum. Attempts to eliminate S. scabiei var. ovis were made in 3 naturally infested sheep herds, by two dippings with two weeks interval with Amitraz, Cypermetrin and Prompetamphos. The results of this study indicate that acaricidal treatment of S. scabiei var. ovis in 3 naturally infested herds was successful, but a few cases of reinfestation were found in each treated group.

No abstract