Sequence analysis of the second internal Transcribed spacer (ITS2) region of rDNA for species identification of trichostrongylus nematodes isolated from domestic livestock in Iran

Background: Infectivity of herbivores with Trichostrongylus nematodes is widespread in many countries, having a major economic impact on breeding, survivability, and productivity of domestic livestock. This study was carried out on Trichostrongylus species isolated from domestic livestock in order to develop an easy-to-perform method for species identification. Methods: Trichostrongylus isolates were collected from sheep, goat, cattle, and buffaloes in Khuzestan Province, southwest Iran. Primary species identification was carried out based on morphological characterization of male worms. PCR amplification of ITS2-rDNA region was performed on genomic DNA and the products were sequenced. Phylogenetic analysis of the nucleotide sequence data was conducted employing Bayesian Inference approach. Consequently, a restriction fragment length polymorphism (RFLP) profile was designed to differentiate Trichostrongylus species. Results: A consensus sequence of 238 nucleotides was deposited in the GenBank for Iranian isolates of Trichostrongylus species including T. colubriformis, T. capricola, T. probolurus and T. vitrinus. The designated RFLP using restriction enzyme TasI could readily differentiate among species having different ITS2 sequence. The molecular analysis was in concordance with morphological findings. Conclusion: Phylogenetic analysis indicated a close relationship among the sequences obtained in this study and reference sequence of relevant species. ITS2-RFLP with TasI is recommended for molecular differentiation of common Trichostrongylus species

Sequence variation in mitochondrial cox1 and nad1 genes of ascaridoid nematodes in cats and dogs from Iran

The study was conducted to determine the sequence variation in two mitochondrial genes, namely cytochrome c oxidase 1 (pcox1) and NADH dehydrogenase 1 (pnad1) within and among isolates of Toxocara cati, Toxocara canis and Toxascaris leonina. Genomic DNA was extracted from 32 isolates of T. cati, 9 isolates of T. canis and 19 isolates of T. leonina collected from cats and dogs in different geographical areas of Iran. Mitochondrial genes were amplified by polymerase chain reaction (PCR) and sequenced. Sequence data were aligned using the BioEdit software and compared with published sequences in GenBank. Phylogenetic analysis was performed using Bayesian inference and maximum likelihood methods. Based on pairwise comparison, intra-species genetic diversity within Iranian isolates of T. cati, T. canis and T. leonina amounted to 0-2.3, 0-1.3 and 0-1.0 for pcox1 and 0-2.0, 0-1.7 and 0-2.6 for pnad1, respectively. Inter-species sequence variation among the three ascaridoid nematodes was significantly higher, being 9.5-16.6 for pcox1 and 11.9-26.7 for pnad1. Sequence and phylogenetic analysis of the pcox1 and pnad1 genes indicated that there is significant genetic diversity within and among isolates of T. cati, T. canis and T. leonina from different areas of Iran, and these genes can be used for studying genetic variation of ascaridoid nematodes. © Cambridge University Press 2014

Molecular Diagnosis of Strongyloides stercoralis Infection by PCR Detection of Specific DNA in Human Stool Samples

Background: Strongyloidiasis is mostly an asymptomatic infection and diagnosis of latent infec­tions is difficult due to limitations of current parasitological and serological methods. This study was conducted to set up a PCR-based method for molecular diagnosis of Strongyloides stercor­alis infection by detection of copro-DNA in stool samples.Methods: A total of 782 fresh stool samples were collected and examined by agar plate culture. Among those sixteen stool samples, which confirmed to be infected with S. stercoralis were exam­ined as positive control to set up each single and nested PCR, using two primer sets design­ing to amplify partial ribosomal DNA of S. stercoralis genome. Since, single PCR method yielded higher efficacy in detecting positive samples, in the second step, 30 stool samples, which found negative for S. stercoralis by agar plate culture of single stool sample, were examined by sin­gle PCR. Data analysis was performed using McNemar's χ2 test, with consideration of a P-value of <0.05 as indication of significant difference.Results: In amplification of DNA extracted from stool samples, single PCR detected S. stercor­alis DNA target in all 16 positive samples, while nested PCR amplified DNA in only 75% of sam­ples. In the second step, single PCR amplified S. stercoralis extracted DNA in 5 out of 30 sam­ples which were negative by coproculture.Conclusion: Single PCR method amplifying a short (100bp) target represented more efficacies for detection of S. stercoralis in faecal examination compared to agar plate culture and nested PCR, which amplified longer target

First molecular identification of Sarcocystis miescheriana (Protozoa, Apicomplexa) from wild boar (Sus scrofa) in Iran

Sarcocystis isolate obtained from the thigh muscle of a wild boar (Sus scrofa), captured from Gilan Province, northern Iran, was subjected to molecular analysis. Genomic DNA was obtained using a DNA extraction tissue kit and Polymerase chain reaction (PCR) for amplification of the 18S ribosomal DNA region yielded an 842. bp DNA band on agarose gel. Analysis of DNA sequencing by BLAST confirmed the isolate as Sarcocystis miescheriana and the sequence was deposited in GenBank by Accession No. GU395554. This is the first molecular identification of an isolate of S. miescheriana in Iran. © 2010 Elsevier Inc

Genetic characterization of Echinococcus granulosus in camels, cattle and sheep from the south-east of Iran indicates the presence of the G3 genotype

Echinococcus granulosus, the aetiologic agent of cystic echinococcosis (CE), is one of the most important zoonotic helminthes worldwide. Isolates of the parasite show considerable genetic variation in different intermediate hosts. Several genotypes and species are described in different eco-epidemiological settings. This study investigated E. granulosus genotypes existing in livestock and humans from the province of Kerman, located in south-eastern Iran, using sequencing data of cox1 and nad1 mitochondrial genes. Fifty-eight E. granulosus isolates, including 35 from sheep, 11 from cattle, 9 from camels and 3 from goats, were collected from slaughterhouses throughout Kerman. One human isolate was obtained from a surgical case of CE. Mitochondrial cox1 and nad1 regions were amplified using polymerase chain reaction (PCR) and 38 isolates were sequenced. Genotypes G1 (73.7%), G3 (13.2%) and G6 (13.1%) were identified from the isolates. G1 was the most common genotype from sheep (86.7%), cattle (80%), camels (44.4%) and goats (100%). Sheep, cattle and camels were also found to be infected with the G3 genotype (buffalo strain). The human isolate was identified as the G6 genotype. Results showed that the G3 genotype occurred in different animal hosts in addition to G1 and G6 genotypes. © 2011 Cambridge University Press

Morphological and Morphometrical Description of Trichostrongylus Species Isolated from Domestic Ruminants in Khuzestan Province, Southwest Iran

Backgrounds: Genus Trichostrongylus (Nematoda: Trichostrongylidae) is one of the most impor­tant zoonotic nematodes with wide geographic distribution in the world. The purpose of the present study was to describe morphological and morphometrical characteristics of male Trichostrongylus species, currently prevalent in domestic ruminants of Khuzestan Province, south­west Iran.Methods: Gastro-intestinal organs of 1600 sheep, goats, cattle, and buffalos, slaughtered in Khuzestan Province, southwest Iran, were examined for infectivity with Trichostrongylus spe­cies. For examination and measurements of helminthes, Azo-carmine staining was per­formed, followed by camera lucida drawings of morphological characters and measurements of morphometrical criteria with a calibrated microscope. Using valid nematodes systematic keys, almost all the parasites were identified at the level of species.Results: Overall, 114 animals were found infected with at least one species of Trichostrongy­lus. Considering morphological characteristics of male Trichostrongylus, six species were identi­fied including T. colubriformis, T. vitrinus, T. probolorus, T. capricola, T. longispicu­laris and Trichostrongylus sp. Conclusion: Although, compared to the previous decades, currently Trichostrongylus is much less prevalent in the domestic ruminants of the study area, but still different species occur in these animals

Identification and differentiation of Fasciola hepatica and Fasciola gigantica using a simple PCR-restriction enzyme method

Accurate morphological differentiation between the liver fluke species Fasciola hepatica and Fasciola gigantica is difficult. We evaluated PCR-restriction enzyme profiles of internal transcribed spacer 1 (ITS1) that could aid in their identification. Fifty F. hepatica and 30 F. gigantica specimens were collected from different hosts in three provinces of Iran. For DNA extraction, we crushed fragments of the worms between two glass slides as a new method to break down the cells. DNA from the crushed materials was then extracted with a conventional phenol-chloroform method and with the newly developed technique, commercial FTA cards. A primer pair was selected to amplify a 463-bp region of the ITS1 sequence. After sequencing 14 samples and in silico analysis, cutting sites of all known enzymes were predicted and TasI was selected as the enzyme that yielded the most informative profile. Crushing produced enough DNA for PCR amplification with both the phenol-chloroform and commercial FTA card method. The DNA extracted from all samples was successfully amplified and yielded a single sharp band of the expected size. Digestion of PCR products with TasI allowed us to distinguish the two species. In all samples, molecular identification was consistent with morphological identification. Our PCR-restriction enzyme profile is a simple, rapid and reliable method for differentiating F. hepatica and F. gigantica, and can be used for diagnostic and epidemiological purposes. © 2009 Elsevier Inc. All rights reserved

Comparison of six simple methods for extracting ribosomal and mitochondrial DNA from Toxocara and Toxascaris nematodes

Six simple methods for extraction of ribosomal and mitochondrial DNA from Toxocara canis, Toxocara cati and Toxascaris leonina were compared by evaluating the presence, appearance and intensity of PCR products visualized on agarose gels and amplified from DNA extracted by each of the methods. For each species, two isolates were obtained from the intestines of their respective hosts: T. canis and T. leonina from dogs, and T. cati from cats. For all isolates, total DNA was extracted using six different methods, including grinding, boiling, crushing, beating, freeze-thawing and the use of a commercial kit. To evaluate the efficacy of each method, the internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit 1 (cox1) gene were chosen as representative markers for ribosomal and mitochondrial DNA, respectively. Among the six DNA extraction methods, the beating method was the most cost effective for all three species, followed by the commercial kit. Both methods produced high intensity bands on agarose gels and were characterized by no or minimal smear formation, depending on gene target; however, beating was less expensive. We therefore recommend the beating method for studies where costs need to be kept at low levels. © 2013 Elsevier Inc

Comparison of six simple methods for extracting ribosomal and mitochondrial DNA from Toxocara and Toxascaris nematodes

Six simple methods for extraction of ribosomal and mitochondrial DNA from Toxocara canis, Toxocara cati and Toxascaris leonina were compared by evaluating the presence, appearance and intensity of PCR products visualized on agarose gels and amplified from DNA extracted by each of the methods. For each species, two isolates were obtained from the intestines of their respective hosts: T. canis and T. leonina from dogs, and T. cati from cats. For all isolates, total DNA was extracted using six different methods, including grinding, boiling, crushing, beating, freeze-thawing and the use of a commercial kit. To evaluate the efficacy of each method, the internal transcribed spacer (ITS) region and the cytochrome c oxidase subunit 1 (cox1) gene were chosen as representative markers for ribosomal and mitochondrial DNA, respectively. Among the six DNA extraction methods, the beating method was the most cost effective for all three species, followed by the commercial kit. Both methods produced high intensity bands on agarose gels and were characterized by no or minimal smear formation, depending on gene target; however, beating was less expensive. We therefore recommend the beating method for studies where costs need to be kept at low levels. © 2013 Elsevier Inc