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

[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

Molecular epidemiology of cryptosporidiosis in Iranian children, Tehran, Iran

Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein [GP60] gene. Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly. Out of 794 collected samples, 19 [2.40%] were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 [89.47%] of the positive isolates were Cryptosporidium parvum and 2 [10.52%] were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa [6/17] and IId [11/17]. The most common allele in all 17 isolates belonged to IId A20G1a [41.18%]. A22G1 [IF] subtype was detected in two C. hominis isolates of the children. The predominancy of C. parvum species [specially, IId A20G1a subtype] in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran

Epidemiology of celiac disease in Iran: a review

Celiac disease [CD] was traditionally believed to be a chronic enteropathy, almost exclusively affecting people of European origin. Celiac disease is the permanent intolerance to dietary gluten, the major protein component of wheat. The availability of new, simple, very sensitive and specific serological tests has shown that CD is as common in Middle Eastern countries as in Europe, Australia and New Zealand where the major dietary staple is wheat. A high prevalence of CD has been found in Iran, in both the general population and the at-risk groups, i.e. patients with type 1 diabetes or irritable bowel syndrome [IBS]. In developing countries, serological testing in at risk groups is necessary for early identification of celiac patients. Clinical studies show that presentation with non-specific symptoms or a lack of symptoms is as common in the Middle East as in Europe. Wheat is a major component of the Iranian diet and exposure to wheat proteins induces some degree of immune tolerance, leading to milder symptoms that may be mistaken with other GI disorders. The implementation of gluten free diet [GFD] is a major challenge for both patients and clinicians in Iran, especially since commercial gluten-free products are not available in this area

[Differentiation of Entamoeba histolytica and Entamoeba dispar by single polymerase chain reaction]

In most part of the world detection of cysts and trophozoites of Entamoeba is based on morphological structure of this species in stool sample by microscopy. However, microscopic examination is unable to distinguish between similar morphological protozoa such as Entarnoeba histolytica and Entamoeba dispar. A simple and cost-effective method is needed in medical laboratories for detection and differentiation of these two species. Stool samples of patients who were referred from health care centers were examined by direct microscopy and trichrome stain. Polymerase chain reaction [PCR] utilizing pEd30F and pEd21AS primers from Peroxiredoxin gene, was used for differentiation of E. histolytica and E. dispar. Genomic DNA from samples was amplified by these primers. The fragment under 100 bp was related to E. histolytica and in contrast the fragment above the 100 bp was related to E. dispar. In this study from 22 microscopic positive samples, E. histolytica was observed only in one patient and E. dispar was detected in the other 21 samples. The result of this study indicate that the PCR reaction could amplify E. dispar and E. histolytica with just one primer pair and this is a cost-effective method for distinguishing between these two species

Prevalence of Entamoeba histolytica and Entamoeba dispar in gonbad city, 2006, Iran

Differential diagnosis of two protozoan parasites Entamoeba histolytica and E. dispar is of great clinical and epidemiological importance, but except in the case of haematophagous trophozoites in acute dysentery, it is not possible to differentiate them by microscopy. The present study was carried out from February 2005 to July 2006 in order to determine the prevalence of E. histolytica and E. dispar in Gonbad City, by using a PCR method. Five hundred and sixty four fecal samples were collected from primary health care centers of Gonbad both urban and rural areas. The stool specimens were examined by light microscopy [Direct slide smear, Iodine wet mount, Formal-ether concentration and Trichrome staining] to distinguish E. histolytica/E. dispar complex and differentiate them from other non-pathogenic intestinal amoebae. The microscopy results of stool exams showed a frequency rate of 23 positive samples [4.07%] for cyst of E. histolytica/E. dispar complex. All the microscopy positive isolates appeared to be infected with cyst of E. histolytica/E. dispar complex were cultivated and maintained successfully in HSr + s medium for DNA extraction and identification by the PCR method. The PCR study showed that 16 isolates [69.56%] of the Entamoeba samples were E. dispar while 7 samples [30.43%] of those microscopy positive samples were not amplified and none of them showed E. histolytica pattern. High frequency rate of E. dispar in this study were in high agreement with the estimation rate of these entamoebas worldwide

analysis of hydatid cyst surgeries in patients referred to hospitals in Khorram-Abad, Lorestan during 2002-06

Echinococcosis or hydatid cyst [HC] is considered as one of the major parasitic infections in Iran that causes many health problems and economic losses in communities. The aim of this study was to determine the prevalence of HC in patients referred to surgery wards of three hospitals in Khorram-Abad, the center of Lorestan province in South-West of Iran from 2002 - 2006. Totally, 64513 medical records of patients referred to surgery wards of Shohadaye Ashayer, Tohid and Taamine Ejtemaee hospitals in Khorram-Abad Lorestan were studied. These patients had gone under surgical operations for different reasons. Among these medical records, 43.7% belonged to Shohadaye Ashayer, 8.2% to Tohid and 18.1% to Taamine ejtemaee hospitals. Cysts were found in liver and lung in 61.5% and 20.5% of cases, respectively. In addition, cysts were found in brain, muscle, kidney eye and peritonea in the remaining 18% of cases. A very low level of knowledge about hydatid disease was found in the community. The mean age of the patients was 40.2 years and the highest rate of infection with HC was observed in women. Further studies are required to find the etiologic factors of H.C in Khorram-Abad Lorestan-Iran