Blastocystis: Emerging Protozoan Parasite with High Prevalence in Iran

Background: Blastocystis is a zoonotic protozoan parasite habit in intestinal tract of humans and wide range of animals. Because of the mysterious nature and unknown or less-known aspects of Blastocystis, comprehensive information about epidemiology of this parasite is not available. The objective of this study was to investigate the available parasitology studies during the last decade in Iran and determine the prevalence of Blastocystis and its position among other intestinal parasites. As well as, investigate the effective factors in its prevalence.Materials and Methods: All available studies related to the prevalence of intestinal parasites in Iran during the recent decade were collected using information databases. After determinant the mean prevalence of each parasite, the most common parasites, and effective factors on their prevalence were assessed and analyzed.Results: Different studies showed that the most common intestinal parasite at this period of time was Blastocystis spp. with 14.6% prevalence rate. Additionally, in 44.5% of cases Blastocystis spp. allocated the first and in 100% of cases, the first to third rank of the most common intestinal parasites in Iran. Giardia lamblia and Entamoeba coli were in the next category.Conclusion: To our knowledge, the present study is the first survey in which the Blastocystis spp. introduces as one of the most common intestinal parasites in human. Various factors, including the low sensitivity of routine diagnostic methods, hosts multiplicity, easy transportation and unknown impressive factors are effective in the increased prevalence of this parasite. The results of this study could improve the attitude of teachers and researchers towards Blastocystis spp

Enterobacteriacea contamination of drinking water of the wells in Romeshkan town

Background: Water is a vital liquid which is contaminatied by multiple biological agents such as; parasites, fungi, viruses and bacteria. The Enterobactriaceae, especially E.Coli are the most important indicator of fecal contamination of water. The aim of this study was to evaluate the Enterobacteriaceae in drinking water of  the wells in Romeshkan town. Material and Methods: 160 of  2.5 liter water samples were collected and quickly transferred to the laboratory under the desired temperature then were concentrated by passing through a 0.45 µm filter. Then the bacteria were differentiated by culture in Macconkey medium and the grown single colonies were cultured on other differentiate media. Results: 18 (%11.25) of the drinking water of the wells were contaminated with E.Coli which in most cases accompanied with other Enterobactoaceae such as; Enterobacter, Citrobacter and Klebsiella. These contaminations had significant relationship with distance between sewage wells and damaged lids of wells. Conclusion: Although the contamination rate was lower than some previous studies, but according to standards of WHO, it is very high. It is suggested that authorities apply pipetting before wells waterborne diseases become epidemic

Prevalence of Enterobious vermicolaris in the primary school students of Kouhdasht rural regions in the academic year of 2007-2008

Background: Enterobious vermicolaris (EV) is a short-lived, tiny, and white human nematode that has afflicted almost one billion people all over the world. The prevalence rate of this parasite varies in diverse regions and is more common among children. This study was aimed to determine the prevalence of EV in primary school students of Kouhdasht rural regions. Methods: The students' parents filled out the questionnaires the samples were coded and gathered in the morning and were sent to the laboratory. The positive and negative results were recorded in a questionnaire after the samples were examined microscopically. Results: Out of 598 samples from the students of Kouhdasht rural regions, 202 ones (33.8%) were found to be afflicted with Enterobious vermicolaris. The obtained results as well as the variables included in the questionnaires were analyzed using chi-square test. Significant differences were observed between the results in terms of different rural areas, using soap regularly to wash hands prior to eating and clinical signs such as thinness, sleep disturbances, irritability, and anal itching. Conclusion: Since the parasite is transferred directly, there is a close relationship between the prevalence rate and the hygienic condition of the society. The exact diagnosis can decrease and prevent the parasite contamination by coordinating health condition with health instructions, as well as by providing health facilities

Genetic Diversity of Human Blastocystis Isolates in Khorramabad, Central Iran

  Background: There are some genetic differences in Blastocystis that show the existence of species or genotypes. One of these genes that help in identifying Blastocystis is SSUrRNA. The aim of this study was assessment of genetic diver-sity of Blastocystis by PCR with seven pairs of STS primers. Methods: This study was done on 511 stool samples collected from patients referred to the health care centers of Khorramabad, Central Iran, in 2012. Ge-nomic DNA was extracted and in order to determine the Blastocystis subtype in contaminated samples, seven pairs of primers STS (subtype specific sequence-tagged site) were used. Results: Out of 511 samples, 33 (6.5%) samples were infected with Blastocystis. Subtype (ST) of 30 samples was identified and three subtypes 2, 3 and 4 were determined. Mix infection was reported 10% which 3.33% of the infection was for the mixture of ST 3 and ST5 and 6.67% was for the mixture of ST 2 and ST 3. Conclusion: The predominant subtype was ST3 that is the main human sub-type. The dominance of ST2 and 5 are important in this study. This superiority has been reported in some of the studies in ST 2 which is different from the studies in other countries, because they have announced priorities of the ST1 and ST6 after ST3

A molecular prevalence of Blastocystis hominis in patients referred to medical diagnosis laboratories in Khorramabad city

Background : Blastocystis hominis is an anaerobic, zoonotic protozoan parasite which inhabits the large intestine of humans and a wide range of other vertebrates. It has a worldwide distribution and infects hosts through the cyst of the parasite by contaminated water or food. Its prevalence is related to hygienic culture, season, exposure to animals, and age. A number of studies in the last decade have confirmed its potential pathogenicity, and many gastrointestinal and extra-gastrointestinal signs have been attributed to it. It has unique morphology, life cycle, and reproduction. The aim of this research is to study molecular prevalence of this parasite in the patients referred to Khorramabad laboratories. Materials and Methods: In this study, conducted for the first time in Lorestan province, 511 stool samples were collected from patients in laboratories of Khorramabad. After DNA was extracted using PCR, the samples were examined for the existence of Blastocystis parasite. Results: Out of the 511 samples studied, 33 ones (6.5%) were infected with Blastocystis. Conclusion: The microscopic diagnosis is challenged by morphological characteristics and other intervening factors, and the PCR method, which has higher sensitivity and specification than other diagnostic methods, is recommended. Concerning the prevalence of the parasite, the world has been divided into two parts of developed and developing countries by the researchers, with 10% and 50% prevalence rates respectively. The 6.5% prevalence in the cited population in Khorramabad is in the range of the prevalence in the developed countries. Therefore, the result is justifiable since springs provide most of the drinking water in the region. However, since ranching is a popular occupation in the region, the prevalence rate is alarming. Therefore, following health instructions and appropriate clothing when exposing to livestock are recommended. In addition, the results of this study and similar studies in the developing countries, on the one hand, and the increasing prevalence of 23% in the US as a developed country, on the other hand, have disturbed the previous division

Genetic Characterization of Hydatid Cysts Isolated from Domestic Animals in Lorestan Province, Western Iran

Background: Regarding hydatid cyst (cystic echinococcosis, CE) as a human public health problem in the West of Iran, molecular data related to the genotypes of Echinococcus granulosus in cattle and sheep in these regions are still insufficient. Here, we evaluated the genotypes of E. granulosus infecting sheep and cattle in western Iran. Methods: Totally, 36 hydatid cysts including 18 hydatid cysts of sheep and 18 hydatid cysts of cattle were collected from Khorramabad slaughterhouse (Lorestan Province), Western Iran between May to September 2014. Protoscoleces or germinal layers were collected from individual cysts, DNA was extracted, and genotyping was performed by sequencing and analyzing mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Results: In sequencing analysis, all of sheep isolates belonged to genotype G1 (sheep strain). Among cattle hydatid cyst isolates, 16/18 (88.9%) were belonged to genotype G1 and 2/18 (11.1%) were belonged to G3 genotype. The phylogenetic analysis showed two clusters; one of the clusters includes cattle G3 genotype and the other cluster represents sheep and cattle G1 genotype that were isolated. Conclusion: The common sheep strain/G1 is predominant genotype in the western part of Iran, followed by G3 genotype, circulating among the animal hosts in this region. Further studies covering a larger number of isolates might be necessary to see if there are other genotypes in the hydatid cyst population in this region of Iran

Efficacy of Pistacia khinjuk Fruits on Viability of Hydatid Cyst Protoscoleces and Its Acute Toxicity in Mice Model

Background: This investigation aimed to evaluate the in vitro scolicidal effects of Pistacia khinjuk methanolic extract against protoscoleces of hydatid cysts and its acute toxicity in mice NMRI model. Methods: Protoscoleces were aseptically extracted from sheep livers having hydatid cysts. Various concentrations of the essential oil (12.5- 100 mg/mL) were used for 10 to 60 min. Viability of protoscoleces was confirmed using eosin exclusion test (0.1% eosin staining). Twenty-four male NMRI mice were used to assess the acute toxicity of P. khinjuk. Results: P. khinjuk extract at the concentrations of 100 mg/mL after 10 min of exposure killed 100% of protoscoleces. Similarly, the mean of mortality rate of protoscoleces after 20 min of exposure to the concentration of 50 mg/mL was 100%. The LD50 of the intraperitoneal injection of the P. khinjuk methanolic extract was 2.8 g/kg and the maximum non-fatal dose was 1.7 g/kg. Conclusion: The findings demonstrated effective scolicidal effects of P. khinjuk extract with no considerable toxicity that might be a natural source for the producing of new scolicidal agent