21 research outputs found

    Prevalence of Zoonotic Intestinal Helminths of Canids in Moghan Plain, Northwestern Iran

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    Background: The present study was aimed to elucidate the status of intestinal hel­minth infec­tions in canids of Moghan Plain, northwestern Iran.Methods: Eighty-five intestine samples from dead or shot wild canids, 59 fecal samples from sheepdogs and 5 from red foxes were collected from 2006 to 2008 and examined in Parasitology department of Pasteur Institute of Iran.Results: Generally, adult worms, larvae, and eggs of 13 species of various parasitic hel­minths were recovered. Necropsy examinations showed that 96.47% animals harbored at least one helminth species. The prevalence of different species in necropsy were Mesoces­toides sp. 84.7%, Rictolaria spp. 55.3%, Macranthorhynchus hirudinaceus 45.9%, Toxocara canis 43.5%, Toxas­caris spp. 35.3%, Joyeuxiella sp. 34.1%; hook­worms; 22.4%, Taenia spp. 11.8%, Alaria spp. 2.4% and Dipylidium caninum 1.2%. Be­sides, eggs belonging to 10 species of parasitic helminths were identified in 46 fecal sam­ples and generally, 30.9% of samples harbored eggs of at least one helminth species.Conclusion: The high prevalence of various helminth infections among canids in Mog­han plain and contamination of environment by helminths eggs may increase the risk of infection for native peo­ple

    Masonry compressive strength prediction using artificial neural networks

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    The masonry is not only included among the oldest building materials, but it is also the most widely used material due to its simple construction and low cost compared to the other modern building materials. Nevertheless, there is not yet a robust quantitative method, available in the literature, which can reliably predict its strength, based on the geometrical and mechanical characteristics of its components. This limitation is due to the highly nonlinear relation between the compressive strength of masonry and the geometrical and mechanical properties of the components of the masonry. In this paper, the application of artificial neural networks for predicting the compressive strength of masonry has been investigated. Specifically, back-propagation neural network models have been used for predicting the compressive strength of masonry prism based on experimental data available in the literature. The comparison of the derived results with the experimental findings demonstrates the ability of artificial neural networks to approximate the compressive strength of masonry walls in a reliable and robust manner.- (undefined

    The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis

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    <p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p

    Comparison of PCR-Based Diagnosis with Centrifuged-Based Enrichment Method for Detection of Borrelia Persica in Animal Blood Samples

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    Background: The mainstay of diagnosis of relapsing fever (RF) is demonstration of the spirochetes in Giemsa-stained thick blood smears, but during non fever periods the bacteria are very scanty and rarely detected in blood smears by mi­cros­copy. This study is aimed to evaluate the sensitivity of different methods developed for detection of low-grade spi­ro­chetemia. Methods: Animal blood samples with low degrees of spirochetemia were tested with two PCRs and a nested PCR tar­get­ing flaB, GlpQ, and rrs genes. Also, a centrifuged-based enrichment method and Giemsa staining were per­formed on blood samples with various degrees of spirochetemia. Results: The flaB-PCR and nested rrs-PCR turned positive with various degrees of spirochetemia including the blood samples that turned negative with dark-field microscopy. The GlpQ-PCR was positive as far as at least one spi­ro­chete was seen in 5-10 microscopic fields. The sensitivity of GlpQ-PCR increased when DNA from Buffy Coat Layer (BCL) was used as template. The centrifuged-based enrichment method turned positive with as low concentra­tion as 50 bacteria/ml blood, while Giemsa thick staining detected bacteria with concentrations ≥ 25000 bacteria/ml. Conclusion: Centrifuged-based enrichment method appeared as much as 500-fold more sensitive than thick smears, which makes it even superior to some PCR assays. Due to simplicity and minimal laboratory requirements, this method can be considered a valuable tool for diagnosis of RF in rural health centers

    Molecular Typing and Phylogenetic Analysis of Some Species Belonging to Phlebotomus (Larroussius) and Phlebotomus (Adlerius) Subgenera (Diptera: Psychodidae) from Two Locations in Iran

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    "nAbstract"nBackground: Haematophagous females of some phlebotomine sandflies are the only natural vectors of Leishmania species, the causative agents of leishmaniasis in many parts of the tropics and subtropics, including Iran. &nbsp;We report the presence of Phlebotomus (Larroussius) major and Phlebotomus (Adlerius) halepensis in Tonekabon (Ma&shy;zanderan Province) and Phlebotomus (Larroussius) tobbi in Pakdasht (Tehran Province). It is the first report of these species, known as potential vectors of zoonotic visceral leishmaniasis in Iran, are identified in these areas."nMethods: In 2006-2007 individual wild-caught sandflies were characterized by both morphological features and sequence analysis of their mitochondrial genes (Cytochrome b).&nbsp; The analyses were based on a fragment of&nbsp; 494 bp at the 3&acute; end of the Cyt b gene (Cyt b 3&acute; fragment) and a fragment of&nbsp; 382 bp CB3 at the 5&acute; end of the Cyt b gene (Cyt b 5&acute; fragment). We also analysed the Cyt b Long fragment, which is located on the last 717 bp of the Cyt b gene, followed by 20 bp of intergenic spacer and the transfer RNA ser(TCN) gene."nResults: Twenty-seven P. halepensis and four P. major from Dohezar, Tonekabon, Mazanderan province and 8 P. tobbi from Packdasht, Tehran Province were identified by morphological and molecular characters. Cyt b 5&acute; and Cyt b 3&acute; fragment sequences were obtained from 15 and 9 flies, respectively. Cyt b long fragment sequences were ob&shy;tained from 8 out of 27 P. halepensis."nConclusion: Parsimony analyses (using heuristic searches) of the DNA sequences of Cyt b always showed mono&shy;phyletic clades of subgenera and each species did form a monophyletic group. "nKeywords: Mitochondrial Cytochrome b, Phlebotomus (Larroussius) major, Phlebotomus (Larroussius) tobbi, Phlebotomus (Adlerius) halepensis, Ira

    Analysis of Plasmodium vivax Merozoite Surface Protein-1 Gene Sequences

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    The emergence of Plasmodium vivax in Dashte Moghan in northwestern Iran has become a major concern for Iranian&apos;s health officials. Knowledge of genetic make up of the P. vivax populations in this area would give us an insight into the origin of the prevalent infections and the possible routes they are introduced. This paper reports the analysis of a variable region between the two interspecies conserved blocks (ICBs) of 5 and 6 of MSP-1 gene in 18 isolates from Dashte Moghan. The results revealed that all the 18 isolates were similar to an Azari Belem-like type with 21 glutamine (Q) in the repeated residues. Our results may give a clue that the resurgent malaria in Dashteh Moghan might have primarily been introduced from Azerbaijan. However, much more molecular and epidemiological evidence are needed to confirm this hypothesis

    "Use of Random Amplified Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR) and ITS2 PCR assays for differentiation of populations and putative sibling species of Anopheles fluviatilis (Diptera: Culicidae) in Iran"

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    Anopheles fluviatilis complex is known to be a vector of malaria in Iran. Since mosquitoes of this species cover a wide geographical range in Iran, they might have evolved into different separated populations. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) assay was used to differentiate geographic populations of this species. DNA was extracted from individual mosquitoes from 8 localities in 4 south and southeast provinces and amplified in PCR reactions using 18 single primers of arbitrary nucleotide sequence. Results of RAPD-PCR showed that Kazeroun populations could simply be differentiated from other populations using a diagnostic fragment amplified with primer UBC-306. But other populations could not be differentiated either visually or by means of statistical analysis. Moreover ITS2 fragments of some selected specimens were amplified using a pair of universal primer and sequenced as a key standard for detection of putative sibling species. Sequence analysis of the ITS2 fragments revealed a very high (100%) homology among the populations. These findings are crucial in epidemiological studies concerning relatedness of geographic populations and vector movement in the region. Results of RAPD-PCR and ITS2 analysis suggest that this taxon in Iran comprises of only one species with a low genetic variation among geographic populations

    Differential Detection of Echinococcus Spp. Copro-DNA by Nested-PCR in Domestic and Wild Definitive Hosts in Moghan Plain, Iran

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    Background: Despite Echinococcus granulosus, there are merely two old reports of E. multilocularis infection among Iranian canids of Moghan Plain, the only area known endemic for the species. We detected specific DNA markers in fecal samples by PCR (Copro-PCR) for differential diagnosis of Echinococcus species in living canids.Methods: Totally 144 fecal samples from domestic dogs, red foxes and a golden jackal were examined for genus-specific Echinococcus coproantigens using ELISA. Forty two positive or ambiguous samples were further examined for Echinococcus species-specific DNA markers by two different set of nested-PCR.Results: Twenty five out of 144 (17.4%) animals were contaminated with E. granulosus including 14 (23.7%) domestic dogs, 10 (11.9%) red foxes and one (100%) golden jackal. But none of them harboured E. multilocularis species-specific Copro-DNA. The overall prevalence of E. granulosus and E. multilocularis infections in canids of the area was estimated to be 17.4% and 0.0%, respectively. There was a significant relation between the results of Copro-PCR and CA-ELISA.Conclusion: The lack of E. multilocularis infection, compared to previous reports may be due to the differences in used diagnostic methods and/or recently limited territories of wild canids and altered their food resources in this particular area

    Prenatal Diagnosis of Congenital Toxoplasmosis: Validity of PCR Using Amniotic Fluid against Indirect Fluorescent Antibody Assay in Mothers

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    Maternal infection with Toxoplasma gondii acquired during pregnancy may result in congenital infection of developing fetuses. Up to now, decision on informed therapeutic abortion of fetuses suspected of having T. gondii infection in Iran has been made based on serological findings in mothers. This might have led to unnecessary abortion of many uninfected children. We evaluated the Polymerase Chain Reaction (PCR) assay on amniotic fluids against serological findings in mothers. PCR results in this study indicated that only about one third of Indirect Fluorescent Antibody (IFA) positive mothers had passed the infection to their children. It was a sigh of relief for the majority of mothers who learned that their infants were uninfected. On the other hand it helped the mothers of infected fetuses out of an awkward predicament by making them able to make a solid decision to terminate the pregnancy or carry their children to term

    Malaria Prevalence in the Middle East

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