Iranian Journal of Parasitology
Volume:4 Issue: 1, Jan-Mar 2009

Cryptosporidium parvum is a ubiquitous protozoan, which develops within the microvillous membrane of enterocytes in a wide variety of vertebrates, including man. Cryptosporidiosis is an important parasite causing severe diseases in the immunodeficient people especially AIDS patients. Cryptosporidiosis has been also reported as a com-mon serious primary cause of outbreaks of diarrhea in newborn calves. The aim of this study was to confirm that P23 was an immunogenic antigen in domestic isolates of C. parvum. We isolated cryptosporidial oocysts from the naturally infected calves. The oocysts were then purified and characterized as C. parvum by nested PCR. To obtain the recombinant P23 protein, we isolated the mRNA from oocyst of C. parvum, and synthesized the cDNA. The cDNA was then amplified using specific primers for P23 gene. Sequencing of PCR product showed 100% homology to the known P23 sequences in GenBank. The double strand P23-cDNA was then cloned in pGEX-5X-2 expression vector and P23-recombinant protein was prepared. West-ern blot analysis of recombinant P23 showed that it could be recognized by the positive C. parvum serum. Furthermore, serum from immunized goat with the recombinant P23 protein also recognized a protein band with approximately 23 kDa in lysates prepared from the oocytes Since P23 is an immunodominant surface glycoprotein expressed in the early phase of infection and the immuno genic epitopes are found in its residual chain of amino acid sequence, the recombinant P23 could be recom-mended as a favorable candidate for vaccination against C. parvum infection.

Glucantime® is the first- line drug for the treatment of all forms of leishmaniasis. Unfortunately, the prevalence of parasites becoming resistant to Glucantime® is increasing in several parts of the world including Iran. As protein is the most important target for drugs in response to a variety of signals including drugs so, it seems expression protein patterns in sensitive and resistant Leishmania parasites could greatly help us about the mechanisms of responses to antileishmanial drugs. In this study, we used 2-dimentional gel electrophoresis (2-DE) method to determine protein expression profiles between drug (Glucantime®) sensitive and resistant Leishmania tropica isolated from Iranian an­throponotic cutaneous leishmaniasis (ACL) patients. We used from the two confirmed genetically of Glucantime® sensitive (Mash-4) and resistant (Mash-927) field strains of L. tropica, isolated from ACL patients in north eastern Iran. The two Leishmania isolates were cultured, promastigotes were harvested followed by protein extraction using TCA/Aceton to study protein profiling, 2-DE was done and gels stained with silver nitrate. At least 2236 distinct protein spots were detected. Twelve spots out of them, showed significant changes in expression in resistant compared to sensitive isolates. Of these, 11 protein spots were up- and one was down-regulated. This preliminary study has showed that a number of proteins differentially expressed in drug (Glucan­time®) resistance L. tropica and probably the role of these proteins are increasing the parasite resistance against the drug and delay in cell death.

Neospora caninum is an intracellular parasite which causes abortion in cattle worldwide. The aim of this study was to determine the seroprevalence of N. caninum in cattle in Babol City, North of Iran. Blood samples were collected from 237 cattle for determining the seroprevalence of N. caninum. A total of 237 serum samples were tested for anti-Neospora antibodies. Serum samples were analyzed for antibodies against N. caninum antigen using a commercial N. caninum ELISA kit. Antibodies to N. caninum were found in 76 of 237 total cattle (32%), 40 of 155 industrial cat­tle (25. 8%) and 36 of 82 rural cattle sera (43. 9%) based on ELISA test results. This study is the first report of Neospora infection in this area. Significant difference was observed regarding infection in industrial and rural cattle (P<0. 01).

The survey for the prevalence of different species of cattle Hyalomma ticks was carried out in three districts (Rawalpindi, Multan and Lahore) of Punjab province in Pakistan. The bionomical conditions suitable for Hyalomma were also studied in laboratory. One hundred specimens of ticks of different genera were collected from each district. After identification, the Hyalomma ticks were reared in laboratory under the influence of varying temperature and humidity. The results showed highest prevalence (67%) of ticks in district Lahore. The highest prevalence (12%) of Hya­lomma ticks and lowest prevalence (3.1%) of Rhipicephalus in cattle was recorded. The bionomical study showed the high­est mean pre oviposition period was during spring while it was lowest in autumn. The mean oviposition period was also highest in spring. The incubation period of the ova of Hyalomma varied in different seasons. No oviposition was recorded at the temperature 100C and 85% humidity. The maximum number of eggs was laid at 340C and lowest egg production oc­curred at 150C. The maximum number of eggs hatched at 320C and 85% humidity. The variation in relative humidity had no appreciable effect on rate of development of ticks while the number of eggs laid increase with rise in temperature.

Anaplasmosis belongs to the complex of several tick-borne diseases and can cause diseases in the livestock with high economical losses. Cattle that recover from acute infection become carriers and the parasite can persist most probably for the lifetime in the blood. The aim of the present study was the determination of the persistently infected cattle in a region of Iran with the previous history of acute anaplasmosis. One hundred and fifty blood samples and corresponding blood smears of cattle without any signs of diseases were prepared from a region in Isfahan/ Iran with the previous history of acute anaplasmosis from March 2007 to July 2007 for cross sectional study of carriers of Anaplasma. The blood smears were first screened by Giemsa staining, the extracted DNA from blood cells were analyzed by Anaplasma marginale specific nested PCR, and PCR-RFLP using primers derived from 16S rRNA gene and restriction endonuclease Bst1107 I. Anaplasma like structures could be identified in the limited amount of erythrocytes of 75 blood smears. In these samples, the percentage of erythrocytes harboring Anaplasma like structures varied from 10-3% to 10-2%. Nested-PCR and PCR-RFLP analysis showed 58 A. marginale positive cases within 75 Anaplasma suspected blood samples. In 150 total blood samples, 50% were A. marinale positive. Our results revealed that the traditional Giemsa staining method is not applicable for the determination of the persistently infected cattle. In addition, the results showed that the carrier animals must be widespread in the Anaplasma endemic areas in Iran.

Intestinal helminths in dogs provide a potential source of infection in humans due to the close contact be­tween humans and dogs. Due to the limited information on parasites infecting dogs in Kaduna State, Nigeria, a cross sec­tional study was conducted with the aim of determining the diversity and prevalence of intestinal helminths of dogs in the area. During the survey, 160 gastrointestinal tracts of dogs killed for meat selected by simple sampling technique were collected and examined for helminths in Kaduna metropolis, latitude 100 50I N and longitude 70 50I E. Of the helminths found, Dipylidium caninum (75.0%), Taenia hydatigena (43.8%), Diphyllobothrium latum (6.3%), Ancylostoma caninum (6.3%) and Toxocara canis (6.3%) were the most common. Female dogs were more likely of contacting intestinal helminths than male dogs (RR = 1.125). Higher mean worm burden was recorded for dogs infected by T. hydatigena and D. caninum than dogs infected by T. canis, D. latum or A. caninum. The presence of these parasites in dogs examined indicates a potential public health problem in Kaduna me­tropolis. Mass enlightenment of dog keepers on the need for periodic veterinary care and restriction of stray dogs through legislation formulation and enforcement are recommended as possible control measures.

Cutaneous leishmaniasis is an important health problem caused by Leishmania spp. As there is no vaccine, drug treatment is the only way to tackle leishmaniasis. In the present study, inhibitory and kill­ing effects of Peganum harmala and Alkana tinctoria extracts on amastigotes and promastigotes forms of Leishmania were evaluated in-vitro. The seeds of Peganum harmala, Stems and roots of Alkanna tictoria were collected and crude extrac­tion carried out. In this experimental study, Leishmania major promastigotes were cultured in RPMI-1640 with 10% FBS at 22-26°C, and infected macrophages with amastigotes were cultured in RPMI-1640 with 10% FBS at 37°C in 5% CO2. Then the extracts of each plant were added to cultivated parasites and incubated for 3 days. Promastigote and amastigote assay was carried out using counting assay based on growth inhibition. The results indicated that both extractions can inhibit the growth of promastigotes, and in concentra­tions of 40µg/ml of P. harmala, 200µg/ml of A. tincturia, and 20 µg/ml of equal combination of P. hamala and A. tincturia are Inhibitory Concentration (IC50) for parasites growth. By adding these concentra­tions of the extracts to the infected macrophages in the culture, their effects were separately eva­lu­ated. The mean of amastigotes number in macrophages in the culture with P. harmala, A. ticturia, combina­tion and control groups were 0.7, 0.7, 0.6, 2.3 amastigotes per macrophage, respectively. By this method, inhibition of intracellular and extracellular growth of L. major was demon­strated suggesting that, plant drugs with efficacy and safe products can be applied as new treatment for cutane­ous leishmaniasis.

Vahlkampfiids contains wide variety of genuses with some known as human pathogens such as Naegleria, Vahlkampfia and non pathogens such as Willaertia. Since there was no evidence of presence of Vahlkampfiids in different sources in Iran, we have analyzed soil samples to clarify the presence of these amebas. Seven soil samples collected in Tehran were analyzed to clarify the presence of Vahlkampfiids in soil sources, using microscopic examination of non nutrient agar cultures and specific Vahlkampfiids primer pair. Vahlkampfiids were detected in 2 out of 7 soil samples by direct examination of cultures. Sequence analysis confirmed that Willaertia magna (W. magna) was present in 2 samples. Additionally, Thecamoeba were detected in all of soil samples. To the best of our knowledge, this is the first report of existing W. magna and Thecamoeba in Iran. Over all, more research should be implicated in Iran for identification of Vahlkampfiids within different environmental sources as well as their pathogenic capability relevant for human beings.

Strongyloides stercoralis is a prevalent parasite in some rural areas in the north of Iran. We decided to investigate whether the 18S ribosomal DNA sequence of the parasite in Iran is similar to the findings of the other re­searchers. We collected 3514 stool samples from Gilan and Mazandaran, northern Iran, during the year 2005-2006, from which 96 were found infected with S. stercoralis. Using Bearman method filariform larvae were isolated. The lar­val DNA was extracted and subjected for PCR amplification and sequencing. We found 2.73% S. stercoralis infection in stool examination. The partially sequence of Iranian S. stercoralis 18S rDNA gene was deposited to GenBank at accession number of EF062571. The 18S rDNA sequence of S. stercoralis in Iran is very similar to the related sequences deposited in GenBank (94-93% identification).

Linguatula serrata, is a cosmopolitan zoonotic parasite. Adult of L. serrrata parasitize the nasopharynx of canids. Con­suming raw glandular material of infected intermediate hosts (camel, sheep, cattle, goat, etc.) can infect human. In Iran, two-humped camel is merely found in cold regions (Ardabil and East Azarbijan provinces) and is in danger of extinc­tion. A seven-year-old two-humped male camel, due to car accident injury was sent to slaughterhouse of Tabriz, Iran. In meat inspection practice, the visceral organs were taken out. A small red nodule having a white center was observed at the surface of the left lobe of lung. To study more, the whole of the left lobe of lung was sent to the parasitology labora­tory. One nymph of L. serrata was separated from the specimen. This is the first report of infection with L. serrate of two-humped camel in Iran.