RESUMO
Background: The nematodes which belong to Haemonchus genes have high ability to show genetic and morphological changes. They can live with convenient adaptation in different hosts
Objectives: A Morphologic and Morphometric comparative study on Haemonchus nematodes from domestic ruminants in the southeast of Iran and comparison of studied parameters with the results of other researches around the world
Methods: During an annual period the 100 adult Haemonchus nematodes [50 male and 50 female] were collected from each domestic ruminant [sheep, goat, cattle and camel] from Neh-bandan [southern Khorasan], Zabol and Zahedan [Sistan and Balouchestan] in the southeast of Iran. In present study the measured parameters are: Total body length of male and female adult nematodes, gubernaculum length, right and left spicule length, the distance between spicule spine and the spicule posterior end, the distance between anterior cervical spine and the anterior end of nematode, the egg diameters. Also, the anterior sections were observed in order to study the longitudinal cuticular ridges [Synloph]. The achieved data from nematodes of each host were compared with others using [One Way Anova and Tukey tests], also such comparison was done with the results of one of the standard sources [Soulsby 1982] using One Sample T Test
Results: The results of present study showed that some of the parameters such as spicule length, distance between right spicule spine and the spicule posterior end, and Synloph pattern in nematodes from sheep and goat are mostly similar to Haemonchus placei. The significant statistical differences in present study results showed high polymorphism in Haemonchus nematodes in the area
Conclusions: It seems that such high polymorphism in present nematodes, especially from sheep and goat has been created due to mating of native nematodes and foreign species with the source of imported cattle
Assuntos
Animais , Bovinos/microbiologia , Ruminantes/microbiologiaRESUMO
In order to deworm the ruminants especially of sheep in Iran, consumption of benzimidazoles has more than 2 decades history and today farmers are using imidazothiazoles, macrocyclic lactones and mostly benzimidazole compounds [BZs] to treat infected farm animals. It has been demonstrated that the most common molecular mechanism leading to BZ sresistance in Haemonchus contortus is a single mutation at amino acid 200 [phenylalanine to tyrosine] of the isotype 1 of beta tubulin gene. According to the report of such mutations in Iranian Teladorsagia circumcincta isolates with Restriction Site Created PCR-RFLP, we decided to evaluate the frequency of such mutations in H. contortus in three different geographical areas of Iran. A total of 102 collected adult male H. contortus were evaluated with PCR-RFLP [using PSP1406I as restriction enzyme]. By means of a second step to compare function of different methods and to increase sensitivity of detection mechanism, a third of samples were examined by another PCR-RFLP method [using TaaI as restriction enzyme] and finally beta tubulin gene of two samples was sequenced. All of samples were detected as BZss homozygote. Finally, beta tubulin gene sequencing of two samples showed no point mutation at codon 200. It seems that BZ resistance of H. contortus in Iran is not a serious problem as anticipated before