ABSTRACT
The aim of the present study was to evaluate the capability of helminths to absorb heavy metals in comparison with that of the host tissues. We compared the concentration of cadmium [Cd] and chromium [Cr] in urban rats and in their harboring helminthes -Moniliformis moniliformis, Hymenolepis diminuta and larval stage of Taenia taenaeiformis [Cysticercus fasciolaris]. The heavy metal absorption was evaluated in 1g wet weight of parasites and tissues digested in nitric acid, using Inductivity Coupled Plasma [ICP-OES]. A higher concentration of heavy metals was revealed in the helminths than in the host tissues. Bioconcentration factor [BF= C in parasite/C in tissue] for both Cd and Cr absorption was more than 10-fold higher in M. moniliformis than in the three compared host tissues. The BF of Cd in M. moniliformis compared to the liver, kidney and muscle of the host was 9.16, 14.14 and 17.09, respectively. BF in Cr in the same parasite and the same host tissues ranged from 10.67, 7.06 and 4.6. High level of absorption in H. diminuta was significantly likewise; the individual BF of Cd and Cr in H. diminuta compared to the liver, kidney and muscle of the hosts was 4.95, 5.94 and 4.67 vs. 2.67, 11.56 and 5.59. The mean concentration of Cd and Cr in C. fasciolaris was also significantly higher than that in the rat livers [P<0.007 and P<0.004, respectively]. This study claims that parasites of terrestrial animals exposed to heavy metals can be more accurate indicators than the host tissues as new environmental monitoring agents
ABSTRACT
<p><b>OBJECTIVE</b>To survey the prevalence of cattle ticks in Nur County and prepare a list of tick fauna in this district.</p><p><b>METHODS</b>This investigation was carried out on 150 head of cattle ticks of rural areas of Nur city which is located in Mazandaran province during spring and summer seasons of 2011. The collected ticks were identified using light microscope and available systematic keys.</p><p><b>RESULTS</b>A total number of 1 563 ticks were isolated from examined cattle and their genus and numbers including: Ixodes ricinus 51% (111 male and 691 female) and Boophilus annulatus 49% (83 male and 678 female), respectively.</p><p><b>CONCLUSIONS</b>Results of the current investigation indicate the presence of two species of acarine ectoparasites which have potential health risk Ixodes ricinus and Boophilus annulatus. More studies are required to increase our data concerning ticks and other ectopreasites of ruminants in other areas of Mazandaran province and should be noted to their ability in transmission of infectious agents.</p>