[One novel PMS2 germline mutation in a patient with hereditary non polyposis colorectal cancer]

Hereditary non polyposis colorectal cancer [HNPCC] is an autosomal dominant syndrome. The cancer appears between 40 and 50 years of age. Mutation in mismatch repair genes can lead to this cancer .One of the genes which is involved in this disease is PMS2 gene. Here, we present a case with a novel germline mutation in PMS2 gene. The aim of this report was to examine PMS2 gene and identify novel germline mutations in this gene. A 77-year-old male with diagnosis of colorectal carcinoma was referred for genetic testing. He suffered from a polyp with a diameter of 6.8 cm in hepatic flexure. The patient did not meet Amsterdam Criteria and Bethesda Guidelines, but screening for HNPCC was performed on account of pathological findings. Blood sample was used for identification of mutation and the paraffin embedded block was prepared for MSI analysis. One mutation in PMS2 gene was detected by analysis of the amplicon sequencing. The mutation was a transitional mutation in position 676 which led to transformation of guanine to adenine resulting in substitution of glutamic acid for glycine. Immunohistochemistry confirmed abnormal expression of PMS2 gene and MSI assay showed instability of sequenced amplicons in this gene

Occurrence of thermotolerant hartmannella vermiformis and naegleria spp. in hot springs of Ardebil province, northwest Iran

Geothermal waters could be suitable niches for thermophilic free living amoebae including Naegleria and Hartmannella. Ardebil Province, northwest Iran is popular for having many hot springs for recreational and health purposes activity. The present research is the first molecular based investigation regarding the presence of Naegleria and Hartmannella in the hot springs of Ardebil Province in Iran. Overall, 30 water samples were taken from waters of thermal hot springs in Ardebil Province, Iran during 2010-2011. All collected samples were transferred to Dept. of Parasitology and Mycology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Cultivation of concentrated water samples was performed using culture-enrichment method. Cloning of the target amoebae was obtained and morphological and molecular analysis was done using page key combined with two sets of primers, respectively. Sequence analysis and homology search was used for strains identification. Of 30 water samples, 8 [26.7%] were positive for thermotolerant Vahlkampfiids and Hartmannella based on morphological characteristics of vegetative form and double walled cysts. Cloning of the target amoebae were done successfully. Sequencing of the positive isolates revealed that the strains belonged to Naegleria [N. carteri and N. spp] and H. vermiformis. The result highlights a need for improved filtration and disinfection and periodic monitoring of recreational thermal waters in order to prevent disease related to free- living amoebae. This is the first comprehensive molecular study of thermophilic Naegleria and Hartmannella in hot springs of Iran

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

Fatal sepsis by Bacillus circulam in an immunocompromised patient

An immunosuppressed man was admitted to hospital with diarrhea and a history of urinary tract infection. He was subjected to treatment with antibiotics. The patient died of putative severe sepsis. The etiological agent was a carbapenemase producing isolate of Bacillus circulans with resistance to all prescribed antimicrobial agents

[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

Prevalence of intestinal parasites in bakery workers in Khorramabad, Lorestan Iran

Food contamination may occur through production, processing, distribution and preparation. In Iran especially in Khorramabad, 33[degree sign] 29' 16" North, 48[degree sign] 21' 21" East, due to kind of nutrition, culture and economic status of people, bread is a part of the main meal and the consumption of bread is high. In this study, the bakery workers were studied for determining of intestinal parasites prevalence. The study was carried out during September to November 2010 in Khorramabad. All the 278 bakeries and the bakery workers including 816 people were studied in a census method and their feces were examined for the presence of parasites by direct wet-mount, Lugol's iodine solution, and formaldehyde- ether sedimentation, trichrome staining, and single round PCR [For discrimination of Entamoeba spp]. Ninety-six [11.9%] stool specimens were positive for different intestinal parasites. Intestinal parasites included Giardia lamblia 3.7%, Entamoeba coli 5.5%, Blastocystis sp. 2.1%, Entamoeba dispar 0.4%, Hymenolepis nana 0.1%, and Blastocystis sp. 0.1%. In order to reduce the contamination in these persons, some cases such as stool exam every three months with concentration methods, supervision and application of accurate health rules by health experts, training in transmission of parasites are recommended

First report of Vannellidae amoebae [vannella spp.] isolated from biofilm source

Members of the Vannellidae family are free-living amoebae [FLA] distributed mainly in water and soil sources. The present study reports the first isolation of this genus in the biofilm source from hospital environment in Tehran, Iran. Biofilm samples were collected from hospital environment. Cultivation was performed in non-nutrient agar covered with a heat-killed Escherichia coli. Cloning of the suspected amoebae was done. PCR amplification and Homology analysis using the Basic Local Alignment Search Tool [BLASTn] was performed to search for the most similar reference sequences. Microscopic examination showed numerous fan-shaped amoebae and peculiar cysts different to the usual shape of typical FLA. Sequence analysis of the PCR- product revealed that the suspected amoebae are highly homologous with Vannella spp. gene [99% identity and 100% query coverage] available in the gene bank database. Although Vannella spp. is not proved to be pathogenic itself, but they are capable of harboring pathogenic intracellular organisms such as Microsporidian parasites. Thus, identification of such amoebae can be of clinical importance, as they could lead to transmission of other pathogens to human

[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