[Molecular determination of Echinococcus granulosus isolated from hydatid cyst using mitoconderial atp6 gene]

Several strains of the Echinococcus granulosus have been described based on morphological characters, intermediate host specificity and/or genetic analysis of mitochondrial and nuclear DNA. The aim of this study was to characterize different E.granulosus isolates by using sequences of mitochondrial atp6 gene. In this study, Sixty infected liver and lungs of cattle, sheep and goats were collected from the abattoir of Varamin city-Iran during 2008. Protoscoleces were removed from each fertile cyst and DNA extracted. New and specific primers were designed for two existing genotypes [G1 and G6] of E. granulosus known to occur in Iran and applied in PCR reactions. The new primers selectively amplified the G1 and G6 genotypes of E. granulosus with specific bands of 708 and 705 bp respectively. The G1 genotype was identified in all fertile cyst samples. This study showed that the new primer pairs which specifically amplify portions of the mitochondrial atp6 gene of the G1 and G6 strains of Echinococcus granulosus are proper molecular marker for investigating genetic variation in a number of isolates of E. granulosus from a range of hosts [sheep, goats, cattle] in Iran. The result of sequenced samples showed that our sequences were the same as those reported previously for these strains

Sequence diversity in tRNA gene locus A-L among Iranian isolates of entamoeba dispar

A number of methods for detecting diversity in Entamoeba have been described over the years. In the present study the genetic polymorphism of noncoding locus A-L was analyzed using PCR and sequencing in order to clarify the genotypic differences among E. dispar isolates. A total of 28 E. dispar from patients with gastrointestinal symptoms were determined and the genomic DNA was extracted directly from stool. For genotype analysis; Locus A-L was amplified by PCR and PCR products were sequenced .The sequences obtained were edited manually and aligned using Gene Runner software. With sequencing of PCR products a reliable genetic diversity in size, number and position of the repeat units were observed among the Iranian E. dispar isolates in locus A-L gene. Sequences showed variation in length from 448bp to 507bp and seven distinct types were identified. The genetic diversity of loci like A-L shows them to be suitable for epidemiological studies such as the characterization of the routes of transmission of these parasites in Iran

[Cryptosporidium genetic diversity based on analysis of COWP, SSU-rRNA and TRAP-C2 polymorphic genes in children with diarrhea in Tehran and qazvin provinces: a survey from Iran]

Since Cryptosporidium is a worldwide distributed protozoan parasite and is considered as one of the most common causes of infection and diarrhea in humans with autoimmune deficiency, as well as in young live stock, molecular epidemiologic studies of cryptosporidiasis will be helpful for underlying transmission and molecular pathogenesis of Cryptosporidium in humans. The aim of the present study was to determine the species and genotypes of Cryptosporidium among children with diarrhea in Tehran and Qazvin provinces by PCRRFLP using the three polymorphic regions of SSU-rRNA, COWP and TRAP-C2 genes. 1263 stool samples were collected from the children less than 12 years with diarrhea who referred to Pediatrics Medical Centers in Gazvin and Tehran Provinces, Iran, during 2005-2007. After determination of the presence of Cryptosporidium oocytes by ZiehlNeelsen acid, fast staining genomic DNA was extracted. Nested PCR-RFLP was performed by -rRNA, COWP and TRAP-C2 genes. Results of microscopically positive samples showed that the overall prevalence of infection in children was 31 [2.5%]. Results of nested PCR amplification showed that of 31 isolates of children, all of three targeted gene were successfully amplified. Our results indicated that the zoonotic transmission is the main mode of infection in Iran and indicates that direct or indirect contact with animals, especially calf, is possibly the main route of human infection

Detection of acanthamoeba from fresh water using polymerase chain reaction

Acanthamoeba is a genus of amoeba, one of the most common protozoa found worldwide in soil, and also frequently found in fresh water. In healthy individuals, Acanthamoeba spp. can cause ulcerating keratitis which is often associated with the use of improperly sterilized contact lenses. The aim of this study was to detect Acanthamoeba from fresh water collected from some town squares of Tehran by polymerase chain reaction [PCR]. In this study, 22 samples were collected from fresh water. They were cultured on NNA medium after filtration. Culture samples positive for Acanthamoeba were assessed using polymerase chain reaction [PCR]. Thirteen samples [59%] were recognized as Acanthamoeba on culture. Using species-specific primers which amplified a 903 bp fragment of 188 rRNA, 6 [27%] samples from 13 samples which were positive on culture were identified as Acanthamoeba. Acanthamoeba has been recognized as an etiologic agent of Keratitis in people who use contact lenses and also in immunocompromised individuals. So, detection of this organism in water resources and exact assessment of this parasite could have a significant role in prevention of disease