use of a migration assay for the separation of adult pyrantel-susceptible and -resistant oesophagostomum dentatum.a migration assay was used to separate a pyrantel-susceptible and -resistant isolate of the pig nematode, oesophagostomum dentatum. the experiment had three steps. in the first step, ld(50) values for pyrantel of the two isolates in the assay were established. in the second step, susceptible and resistant worms were mixed in various proportions prior to exposure to a fixed concentration of pyrantel and thereafter assayed. the inhibition of migration showed to be linearly correlated with the prop ...200010889366
the sexually linked mpi locus is presumably involved in imidothiazole resistance in oesophagostomum dentatum parasites.information about genetic changes during the selection process could indicate mechanisms underlying the spread of resistance to anthelmintic drugs. for clarification of the role of the mpi locus encoding mannose-phosphate isomerase enzyme in determining resistance, genotyping of oesophagostomum dentatum strains was performed using an isoelectrofocusing technique. in levamisole- and pyrantel-selected strains the allele associated with resistance has probably been found. significant values for gen ...200010894475
fatty acid patterns of different stages of oesophagostomum dentatum and oesophagostomum quadrispinulatum as revealed by gas methylated fatty acid patterns of various developmental stages (third-stage larvae (l3), l3 and fourth-stage larvae (l4) cultured in vitro, l4 and female and male adults derived from intestinal contents) of the porcine nodular worms oesophagostomum dentatum and oesophagostomum quadrispinulatum and their cultivation medium were analysed by gas chromatography using microbial identification computer software. fatty acids ranging from c-12 to c-20 could be separated. for each stage and species ...200010899526
nose-rings and transmission of helminth parasites in outdoor pigs.five growing pigs experimentally infected with low doses of oesophagostomum dentatum, ascaris suum, and trichuris suis were turned out with 5 helminth-naïve pigs on each of 3 pastures in june 1996 (group 1). on one pasture all pigs received nose-rings. after slaughter of group 1 in october, pasture infectivity was monitored using helminth-naïve, unringed tracer pigs. in 1997, helminth-naïve young pigs were turned out on the contaminated pastures in may (group 2) and again in august (group 3). ag ...200010965566
assessment of antibody-independent cellular cytotoxicity (aicc) of porcine neutrophilic granulocytes by quantitative flow cytometry. lack of modulation by larval products of oesophagostomum dentatum.after infection of pigs by the larvae of oesophagostomum dentatum, granulomas are formed around the third-stage larvae in the submucosa of the gut which contain a considerable number of neutrophils. this has no obvious impact on the larvae, which develop to fourth-stage larvae within these granulomas. we therefore asked, whether the products of o. dentatum larvae modulate the functional capacity of porcine neutrophils. the antibody-independent cellular cytotoxicity (aicc) was chosen as a model s ...200011075549
comparative studies on the development of oesophagostomum dentatum in vitro and in vivo.although in vitro cultivation of oesophagostomum dentatum provides defined material of third- (l3) and fourth- (l4) stage larvae, these are morphologically and biochemically different from larvae recovered ex vivo. the development of pre-cultivated larvae was investigated by rectal transplantation into worm-free pigs with subsequent recovery of worms from intestinal contents after different time periods and determination of worm burdens and sizes. additionally, the in vitro maintenance of l4 and ...200111199847
characterisation of stage-specific proteins of oesophagostomum dentatum by preparative isoelectric focusing and lectin blotting.the nodular worm of pigs, oesophagostomum dentatum, has previously been shown to undergo distinct biochemical changes during its life cycle. this phenomenon was studied in more detail for the early parasitic stages. differences between infective third-stage larvae (l3), parasitic fourth-stage larvae cultivated in vitro (l4c), and pre-adult larvae recovered from the intestinal contents of pigs (l4p) were compared with respect to their protein and glycoprotein patterns by solubility-based protein ...200111267931
differentiation of two oesophagostomum spp. from pigs, o. dentatum and o. quadrispinulatum, by computer-assisted image analysis of fourth-stage larvae.a method was developed to differentiate between fourth-stage larvae (l4) of two species of porcine nodular worms, oesophagostomum dentatum and o. quadrispinulatum, by computer-assisted analysis of digitised microphotographs of l4 grown in vitro for various time periods and of l4 ex vivo. the overall lengths of the larvae and the lengths of the oesophagus as well as parameters describing the shape of the oesophagus and buccal capsule were measured and a formula based on these parameters was devel ...199911269327
autofluorescence microscopy for the detection of nematode eggs and protozoa, in particular isospora suis, in swine faeces.parasites from swine faeces were examined for autofluorescence. oocysts of eimeria polita, e. scabra and isospora suis, cysts of balantidium coli and eggs of oesophagostomum dentatum, strongyloides ransomi and trichuris suis (but not those of ascaris suum) emitted light after excitation with uv light. i. suis oocyst counts in mcmaster chambers utilising autofluorescence were compared to those from conventional bright field microscopy. similarly, faecal smears containing i. suis were examined usi ...200111403385
the influence of stocking rate on transmission of helminth parasites in pigs on permanent pasture during two consecutive summers.this study was made to elucidate the transmission of nematode infections in outdoor pigs at different stocking rates during two consecutive seasons. five pigs (group 1a) inoculated with low doses of oesophagostomum dentatum, ascaris suum, and trichuris suis and five helminth-naïve pigs (group 1b) were turned out together in june 1996 on each of four pastures at stocking rates of 100, 240 (two pastures) and 576m(2) per pig, respectively. the pigs were slaughtered in early october, and pasture inf ...200111470180
sequence variations in the introns of the triosephosphate isomerase genes of oesophagostomum dentatum and o. quadrispinulatum.degenerated primers were used to amplify dna fragments of the triosephosphate isomerase (tpi) gene from complementary dna (cdna) and from genomic dna of two species of porcine gastrointestinal nematodes, oesophagostomum dentatum and o.quadrispinulatum. polymerase chain reaction (pcr) fragments amplified from cdna were 520 bp in size for both species, while genomic fragments were 1,035 bp for o. dentatum (gc-content: 45%) and 1,331 bp for o. quadrispinulatum (44%). sequence analyses revealed bloc ...200111570563
the effect of dietary carbohydrates with different digestibility on the populations of oesophagostomum dentatum in the intestinal tract of experiment was undertaken to study the effect of dietary carbohydrates with different digestibility on the populations of oesophagostomum dentatum in the intestinal tract of pigs. sixty-four worm-free pigs from a specific pathogen-free farm were randomly divided into 8 equal groups. the animals in 4 groups were assigned to a diet with partially undegradable carbohydrates (diet 1), while the pigs in the 4 remaining groups were given a diet with fermentable carbohydrates (diet 2). diet 1 was co ...200111578096
chickens and pigs as transport hosts for ascaris, trichuris and oesophagostomum eggs.ten chickens and 2 pigs were fed non-embryonated eggs of ascaris suum, trichuris suis and oesophagostomum dentatum. each chicken was fed approximately 15,000 eggs of each parasite species while approximately 300,000 eggs were given to each of the pigs. after passage in chickens 8.3% of o. dentatum eggs were recovered in faeces compared to 61.1% and 38.4%, 49.1% and 30.3%, 41.6% of a. suum and t. suis eggs, respectively. after passage in pigs the percentages were respectively. after embryonation ...200111578097
ecological influences on transmission rates of ascaris suum to pigs on pastures.a study was conducted to determine the distribution and transmission rate of ascaris suum eggs and oesophagostomum dentatum larvae in a pasture/pig house facility, which during the preceding summer was contaminated with helminth eggs by infected pigs. in may, four groups of 10 helminth naïve tracer pigs were exposed to fenced sections of the facility for 7 days and necropsied for parasite recovery 9-10 days later (trial 1). the highest rate of a. suum transmission (201 eggs per day) occurred in ...200111587843
oesophagostomum dentatum: expression patterns of enzymes involved in eicosanoid production.cytosolic and membrane-bound proteins of various stages of oesophagostomum dentatum, the nodular worm of pigs, were investigated for the presence of lipoxygenases (lox) and cyclooxygenases (cox) using polyclonal and monoclonal antibodies. putative 12-lox and 15-lox, but not 5-lox, were detected in both fractions of all developmental stages in the expected size range of 75 kda, with an isoelectric point of 6.0-6.5. the protein could be precipitated with 50% ammonium sulfate, as described for mamm ...200111595578
the impact of season and vegetation on the survival and development of oesophagostomum dentatum larvae in pasture plots.pats of pig faeces containing known numbers of oesophagostomum dentatum eggs were placed on plots with bare soil, short or tall herbage on 8 occasions during 1 year. the number of eggs and larvae and the relative distribution of larvae in faeces, soil and herbage was monitored for 1 year after deposition. on 2 occasions soil from 8 selected plots was given to pigs, which were later slaughtered and examined for the presence of adult o. dentatum. less than 1% of the deposited eggs could be recover ...200111676373
products of fourth-stage larvae of oesophagostomum dentatum induce proliferation in naïve porcine mononuclear cells.infection of pigs with oesophagostomum dentatum is a major cause of economic losses in pig productions. whether infection with this nematode results in a protective immunity is still in debate and information about immune-modulating properties of o. dentatum are lacking. the present study investigated the question whether products of o. dentatum larvae modulate the proliferative response of porcine blood mononuclear cells (pomnc) in vitro. the pomnc of naïve and o. dentatum-infected pigs were cu ...200111708679
characteristics of a flubendazole resistant isolate of oesophagostomum dentatum from germany.two controlled tests were performed to investigate the benzimidazole resistance of a nodular worm isolate "gibz" from a pig breeding farm in germany. in trial i, groups of five pigs, artificially infected with oesophagostomum larvae isolated from that farm were treated with flubendazole at a single dose of 5 mg kg(-1) bodyweight (bw) or remained untreated. in trial ii, three groups of three pigs each infected with larvae after a further laboratory passage of this isolate were treated with fluben ...200211751004
analysis of serum and whole blood values in relation to helminth and ectoparasite infections of feral pigs in the summers of 1996 and 1997, 60 wild pigs (sus scrofa) were necropsied from three sites in south texas (usa) to test the hypothesis that serum and whole blood parameters vary significantly (p < or = 0.05) with the prevalence and intensity of parasites infecting wild pigs. we found ten parasite species: five nematodes (metastrongylus salmi, metastrongylus pudentotectus, stephanurus dentatus, oesophagostomum dentatum, and physocephalus sexalatus); four ixodid ticks (amblyomma cajennense, ambly ...200212038138
a male-specific (cysteine-rich) protein of oesophagostomum dentatum (strongylida) with structural characteristics of a serine protease inhibitor containing two trypsin inhibitor-like domains.a cdna was isolated from an adult male oesophagostomum dentatum gene library by screening with a male-specific, partial expressed sequence tag (est) probe identified previously using a differential display technique. the full-length cdna of 642 bp included 5' and 3' untranslated regions of 44 and 121 nucleotides, respectively, and encoded a predicted protein with a putative 18 amino acid signal sequence and a mature polypeptide of 14.7 kda comprising approximately 15% cysteine residues. the amin ...200212458828
molecular characterisation of a male-specific serine/threonine phosphatase from oesophagostomum dentatum (nematoda: strongylida), and functional analysis of homologues in caenorhabditis elegans.a male-specifically expressed sequence tag was used as a probe to screen adult male oesophagostomum dentatum (nematoda; strongylida) gene libraries. the cdna clones isolated coded for a serine/threonine protein phosphatase with approximately 85% identity to two caenorhabditis elegans proteins implicated in reproduction. however, the genomic structures for the two species were distinct, in that the o. dentatum gene contained seven introns, whereas the c. elegans homologues contained three (two of ...200312670516
the effect of inulin and sugar beet fibre on oesophagostomum dentatum infection in pigs.the present study was designed to assess the role of inulin and sugar beet fibres (sbf) on adult o. dentatum in growing pigs. four experimental diets were formulated based on barley flour with added insoluble fibre from oat husk (diet 1), a pure carbohydrate source inulin (diet 2), soluble fibre from sugar beet fibre (sbf) with a high proportion of soluble fibre components (diet 3) or inulin plus sbf (diet 4). thirty-two 10-week-old pigs were divided randomly into 4 groups each of 8 pigs. after ...200312885189
wild boar helminths: risks in animal translocations.the helminth populations found in a group of wild boars collected in central spain were compared to those in a group of animals imported from a french game farm that produces boars for restocking. eleven helminth species, including ten nematodes and one acanthocephalan, were found. gongylonema pulchrum and macracanthorhynchus hirundinaceus were only detected in autochthonous wild boars, while oesophagostomum dentatum, ascaris suum, and trichuris suis were detected in imported animals only. autoc ...200312944047
studies on the heterophile antibodies associated with helminth infections. iii. heterophile antibody in oesophagostomum dentatum infection in pigs. 195813587704
effects of oesophagostomum dentatum and dietary carbohydrates on morphology of the large intestine of pigs.the effects of oesophagostomum dentatum infection and dietary carbohydrates on the morphology and epithelial cell proliferation in the gastrointestinal tract of pigs were investigated experimentally. thirty-two worm-free pigs (n=32) from a specific pathogen-free farm were randomly divided into four groups (a-d), of eight animals each. pigs in groups a (control) and b (infected) were fed diet 1, and pigs in groups c (control) and d (infected) were fed diet 2. the two diets were formulated: diet 1 ...200314519317
methyridine (2-[2-methoxyethyl]-pyridine]) and levamisole activate different ach receptor subtypes in nematode parasites: a new lead for levamisole-resistance.1. the development of resistance to all chemotherapeutic agents increases and needs to be addressed. we are interested in resistance in parasitic nematodes to the anthelmintic levamisole. during studies on methyridine, we found that it gave us a new insight into pharmacological changes associated with levamisole resistance. initially, electrophysiological investigation using a two-micropipette current-clamp recording technique revealed that methyridine acts as a cholinergic agonist on nematode m ...200314581174
efficacy of an in-feed preparation of ivermectin against helminths in the european wild boar.the wild boar is one of europe's most popular game species and its densities are increasing. management tools such as farm breeding, supplementary feeding, and translocations are more frequently employed and anthelmintics are increasingly used in game farms and translocations. here, we report the results of a controlled slaughter study on the efficacy of an in-feed preparation of ivermectin in european wild boars naturally infected with various helminths. the efficacy of ivermectin against adult ...200414648206
survival and viability of ascaris suum and oesophagostomum dentatum in ensiled swine faeces.the survival and viability of eggs from ascaris suum and oesophagostomum dentatum and of infective larvae (l3) from o. dentatum were determined in the ensiled solid fraction of swine faeces after 0, 7, 14, 28 and 56 days of ensiling. the experiment had two treatments, un-ensiled and ensiled manure, in a split-plot design. each of 50 containers was inoculated with 40,000 eggs of both a. suum and o. dentatum, and another 50 containers were inoculated with 32,747 l3 of o. dentatum each. a. suum egg ...200415158505
effects of short-chain fatty acids and lactic acids on survival of oesophagostomum dentatum in pigs.the direct influence of intracaecal infusion of short-chain fatty acids (scfa) and lactic acids (la) on already established oesophagostomum dentatum infection in cannulated pigs was investigated. we tested the hypothesis that the previously discovered anti-parasitic effect of inulin is mediated through its metabolic products scfa and la by infusing into cannulated pigs these compounds in amounts approximating to those produced in the pigs large intestine and caecum during the metabolism of inuli ...200415262007
vertical migratory behavior of the infective third-stage larvae of oesophagostomum dentatum.the vertical migratory behavior of third-stage infective larvae (l3i) of oesophagostomum dentatum was investigated using upright truncated agarose cones and equivalent conical depressions in agarose. geotactic response varied with the age of the infective larvae. four-day-old l3i showed no preference for the sloping surfaces of either indented or upright cones, while the 8-day-old l3i showed a positive geotactic reaction, migrating down the sloping surface of the depressions.200415325047
characterization of major sperm protein genes and their expression in oesophagostomum dentatum (nematoda: strongylida).major sperm protein (msp) genes were isolated from complementary (cdna) and genomic dna libraries prepared from the parasitic nematode, oesophagostomum dentatum, characterized at the nucleotide and amino acid (aa) levels, and their expression was investigated. three different msp cdna and 2 genomic sequences were determined, each with an open reading frame (orf) of 381 nucleotides. nucleotide variation was detected at 30 positions in the orf among all 5 sequences. conceptual translation of the f ...200415521637
ecdysis of oesophagostomum: possible involvement of eicosanoids and development of a bioassay.bioassays were developed and applied to test the role of eicosanoids and ph changes in ecdysis of oesophagostomum dentatum. exsheathment (80-100%) was achieved by subjecting third-stage larvae (l3) either to chlorine (hypochlorite assay) for 5 min or by incubating them in hcl followed by addition of nahco3 (ph-change assay) with subsequent cultivation at 38.5 degrees c/10% co2 for 1 week. addition of the lipoxygenase (lox) inhibitor diethylcarbamacine (dec) to the larvae resulted in a reduction ...200515739071
new oral linguiform projections and their associated neurons in the third-stage infective larva of the parasitic nematode oesophagostomum dentatum.the infective larvae (l3i) of the nematode parasite of swine, oesophagostomum dentatum, are passively ingested by their hosts. the l3i exhibit certain behaviors that are probably selected to increase the likelihood of ingestion, by strategic positioning in the environment. the larvae show positive geotactic behavior and respond to temperature variations in their environment, as shown by their behavior on a thermal gradient. to investigate neuronal control of this behavior, we initiated a study o ...200515856873
excretion in feces and mucosal persistence of salmonella ser. typhimurium in pigs subclinically infected with oesophagostomum determine interactions between oesophagostomum spp and salmonella ser. typhimurium in pigs.200216206794
insights into the epidemiology and genetic make-up of oesophagostomum bifurcum from human and non-human primates using molecular tools.the nodule worm oesophagostomum bifurcum (nematoda: strongylida) is a parasite of major human health importance predominantly in northern togo and ghana. currently, it is estimated that 0.25 million people are infected with this nematode, and at least 1 million people are at risk of infection. infection with this parasite causes significant disease as a consequence of encysted larvae in the wall of the large intestine. in spite of the health problems caused by o. bifurcum, there have been signif ...200616332292
construction of gender-enriched cdna archives for adult oesophagostomum dentatum by suppressive-subtractive hybridization and a microarray analysis of expressed sequence the present study, we constructed gender-enriched cdna libraries for the adult stage of the parasitic nematode oesophagostomum dentatum (order strongylida) using suppressive-subtractive hybridization (ssh), sequenced clones from the female-library and male-library (480 from each) and conducted bioinformatic and microarray analyses of the expressed sequence tags (ests). in total, 873 ests (440 male and 433 female) were obtained, achieving a sequencing success of 91%the nucleotide sequences rep ...200616426483
ubiquitin-conjugating enzyme genes in oesophagostomum dentatum.full-length genes representing different isoforms of the ubiquitin-conjugating enzyme ubc-2 were isolated from oesophagostomum dentatum, cloned and sequenced. the alignment of their sequences (designated od-ubc-2.1 to od-ubc-2.3) revealed nucleotide variation at three positions within the predicted open reading frame of 444 bp. substitutions were at positions 141 (a<-->g), 142 (a<-->g) and 296 (t<-->c). both former substitutions resulted in amino acid changes from a glycine residue to an arginin ...200616518612
oesophagostomum dentatum and trichuris suis infections in pigs born and raised on contaminated paddocks.transmission of oesophagostomum dentatum and trichuris suis was studied in outdoor reared pigs. six farrowing paddocks were naturally contaminated in may to mid-june 2001 by experimentally infected seeder pigs. in early july 1 sow farrowed on each paddock and starting at week 3 post-partum (p.p.) the offspring was slaughtered serially every 2 weeks for parasite recovery. faeces were collected regularly for parasite egg counts and acid-insoluble ash (aia) content as an indicator of geophagy. wean ...200616740181
[prevalence of eimeria and intestinal nematodes in wild boar in north-west poland].in the time from september 2003 to march 2004 feacal samples of 147 wild boars from north-west poland were examined. the prevalence and intensity of the coccidia and gastro-intestinal nematodes infection were determined by means of willis-schlaaf. the species were determined basing on morphology of oocysts (shape, colour, form index, presence or absence of micropyle and its cap, presence or absence of residual, polar and stied bodies) and time of sporulation. sporulation was performed in wet cha ...200416865979
oesophagostomum dentatum: potential as a model for genomic studies of strongylid nematodes, with biotechnological prospects.there are substantial gaps in the knowledge of the molecular processes of development and reproduction in parasitic nematodes, despite the fact that understanding such processes could lead to novel ways of treating and controlling parasitic diseases, through blocking or disrupting key biological pathways. biotechnological advances through large-scale sequencing projects, approaches for the analysis of differential gene and protein expression and functional genomics (e.g., double-stranded rna int ...200717350211
a comparison of the efficacy of two ivermectin formulations against larval and adult ascaris suum and oesophagostomum dentatum in experimentally infected pigs.a study was conducted to evaluate and compare the efficacy of two injectable formulations of ivermectin (ivm-1 and ivm-2) at a dose rate of 0.3 mg/kg bodyweight versus placebo in the treatment and control of larval and adult stages of ascaris suum and oesophagostomum spp. in experimentally infected pigs. seventy helminth free pigs were allocated on a liveweight basis to 7 groups each comprising 10 pigs (a-g). group a served as an untreated control group. groups b and c were used to investigate t ...200717418952
trichostrongylus vitrinus (nematoda: strongylida): molecular characterization and transcriptional analysis of tv-stp-1, a serine/threonine phosphatase gene.a full-length cdna (tv-stp-1) encoding a serine/threonine protein phosphatase (tv-stp-1) was isolated from trichostrongylus vitrinus (order strongylida), an economically important parasitic nematode of small ruminants. the uninterrupted open reading frame (orf) of 951 nucleotides encoded a predicted protein of 316 amino acids (aa), containing the characteristic motif [livmn]-[kr]-g-n-h-e. comparison with other sequences in non-redundant databases showed that tv-stp-1 had significant identities/s ...200717490653
visceral helminths of wild boars (sus scrofa leucomystax) in japan, with special reference to a new species of the genus morgascaridia inglis, 1958 (nematoda: schneidernematidae).twenty-nine japanese wild boars (sus scrofa leucomystax), collected during the hunting seasons of 2005 and 2006 in the western part of the mainland of japan (honshu), were examined for their visceral helminths. eighteen helminth parasites were prevalent in them, including 17 nematoda species (metastrongylus elongatus, metastrongylus salmi, metastrongylus asymmetricus, metastrongylus pudendotechus, stephanurus dentatus, gnathostoma doloresi, physocephalus sexulata, ascarops strongylina, capillari ...200818328113
the prevalence of gastrointestinal helminth infections in pigs in kenya.the prevalence of helminth infection, species spectrum and worm burdens in kenyan pigs was examined. a total of 115 gastrointestinal tracts (git) from 61 growers and 54 adult pigs were examined between february 2005 and january 2006. seventy eight (67.8%) had one or more helminth parasites, of which thirty six (31.3%) were mixed infection. ten types of helminth parasites encountered in descending order of prevalence were, oesophagostomum dentatum (39.1%), trichuris suis (32.2%), ascaris suum (28 ...200818509940
a multiplex pcr tool for the specific identification of oesophagostomum spp. from pigs.based on the sequences of the internal transcribed spacers (its-1 and its-2) of nuclear ribosomal deoxyribonucleic acid (dna) of the porcine nodule worms oesophagostomum dentatum and o. quadrispinulatum, a pair of specific primers (odspf/odspr2) for o. dentatum and a pair of specific primers (oqspf/oqspr) for o. quadrispinulatum were designed and used to develop a multiplex polymerase chain reaction (pcr) assay for the identification and differentiation of the two porcine nodule worms. this appr ...200818581142
cytosolic glutathione s-transferases of oesophagostomum dentatum.oesophagostomum dentatum stages were investigated for glutathione s-transferase (gst) expression at the protein and mrna levels. gst activity was detected in all stages (infectious and parasitic stages including third- and fourth-stage larvae of different ages as well as males and females) and could be dose-dependently inhibited with sulfobromophthalein (sbp). addition of sbp to in vitro larval cultures reversibly inhibited development from third- to fourth-stage larvae. two glutathione-affinity ...200818771610
characterization of a caenorhabditis elegans glc seven-like phosphatase (gsp) orthologue from haemonchus contortus (nematoda).a full-length complementary dna (cdna; designated hc-stp-1) encoding a serine/threonine phosphatase (hc-stp-1) was isolated from haemonchus contortus, a strongylid nematode parasite of small ruminants. hc-stp-1 was shown to be transcribed in males of both adults and fourth-stage larvae, but not in females, early larval stages or eggs. the full-length gene (2854 bp) contained ten exons and nine introns, and encoded a cdna of 951 bp. comparisons of the conceptually translated protein (316 amino ac ...201020153820
microfluidic bioassay to characterize parasitic nematode phenotype and anthelmintic resistance.with increasing resistance to anti-parasitic drugs, it has become more important to detect and recognize phenotypes of resistant isolates. molecular methods of detecting resistant isolates are limited at present. here, we introduce a microfluidic bioassay to measure phenotype using parameters of nematode locomotion. we illustrate the technique on larvae of an animal parasite oesophagostomum dentatum. parameters of sinusoidal motion such as propagation velocity, wavelength, wave amplitude, and os ...201120663251
a practical, bioinformatic workflow system for large data sets generated by next-generation sequencing.transcriptomics (at the level of single cells, tissues and/or whole organisms) underpins many fields of biomedical science, from understanding the basic cellular function in model organisms, to the elucidation of the biological events that govern the development and progression of human diseases, and the exploration of the mechanisms of survival, drug-resistance and virulence of pathogens. next-generation sequencing (ngs) technologies are contributing to a massive expansion of transcriptomics in ...201020682560
identification and characterization of a serine protease inhibitor with two trypsin inhibitor-like domains from the human hookworm ancylostoma duodenale.protease inhibitors play important roles in the parasitic nematodes' survival within their host, in the development and reproduction of the parasites. the present study described the isolation, identification, and characterization of a novel member of the ascaris family of serine protease inhibitors, designated adutil-1, from the human hookworm ancylostoma duodenale. adutil-1 is composed of a signal sequence and two trypsin inhibitor-like (til) domains, which showed the highest similarity with o ...201120852886
prostaglandin d(2) synthesis in oesophagostomum dentatum is mediated by cytosolic glutathione s-transferase.glutathione s-transferases (gsts) of oesophagostomum dentatum possess considerable similarity to synthetic prostaglandin d synthase (pgds), and therefore their ability to convert prostaglandin (pg) h(2) to pgd(2)in vitro was investigated with a commercial prostaglandin d synthase inhibitor screening assay kit. fractioned homogenates of o. dentatum third-stage larvae only displayed cytosolic but not microsomal gst. both total larval homogenate and isolated gst could metabolise pgh(2) to pgd(2), w ...201021056037
oesophagostomum dentatum: effect of glutathione s-transferase (gst) inhibitors on gst activity and larval development.sulphobromophthalein (sbp) inhibits isolated glutathione s-transferase of the porcine nodule worm oesophagostomum dentatum (od-gst) and reduces larval development in vitro. in this study possible inhibitory effects of various inhibitors were evaluated in an enzymatic (cdnb) assay with isolated od-gst and in a larval development assay (lda). reversibility was tested in the lda by removing the inhibitor from culture halfway through the cultivation period. sbp, indomethacin and ethacrynic acid inhi ...201121241694
rnai effector diversity in nematodes.while rna interference (rnai) has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. to test if this is due to inter-species differences in rnai effector complements, we performed a primary sequence similarity survey for orthologs of 77 caenorhabditis elegans rnai pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were available, with all outputs subjected to domain-structure verification. our ...201121666793
Transcription profiles for two key gender-specific gene families in Oesophagostomum dentatum during development in vivo and in vitro.In strongylid roundworms, such as Oesophagostomum dentatum (porcine nodule worm), some sex-specific genes are likely to be associated with parasite maturation, development and reproduction. In this study, an analysis of transcription of the two sex-specific genes (vit and msp) encoding vitellogenin and major sperm protein of O. dentatum, respectively, revealed that adult females transcribed vit and adult males msp at high levels, in contrast to immature larval stages and pre-adult worms from in ...201222080851
cracking the nodule worm code advances knowledge of parasite biology and biotechnology to tackle major diseases of livestock.many infectious diseases caused by eukaryotic pathogens have a devastating, long-term impact on animal health and welfare. hundreds of millions of animals are affected by parasitic nematodes of the order strongylida. unlocking the molecular biology of representatives of this order, and understanding nematode-host interactions, drug resistance and disease using advanced technologies could lead to entirely new ways of controlling the diseases that they cause. oesophagostomum dentatum (nodule worm; ...201526026709
anthelmintic activity of chicory (cichorium intybus): in vitro effects on swine nematodes and relationship to sesquiterpene lactone composition.chicory is a perennial crop that has been investigated as a forage source for outdoor-reared ruminants and pigs, and has been reported to have anthelmintic properties. here, we investigated in vitro anthelmintic effects of forage chicory-extracts against the highly prevalent swine parasites ascaris suum and oesophagostomum dentatum. methanol extracts were prepared and purified from two different cultivars of chicory (spadona and puna ii). marked differences were observed between the anthelmintic ...201626935644
anthelmintic activity of trans-cinnamaldehyde and a- and b-type proanthocyanidins derived from cinnamon (cinnamomum verum).cinnamon (cinnamomum verum) has been shown to have anti-inflammatory and antimicrobial properties, but effects on parasitic worms of the intestine have not been investigated. here, extracts of cinnamon bark were shown to have potent in vitro anthelmintic properties against the swine nematode ascaris suum. analysis of the extract revealed high concentrations of proanthocyanidins (pac) and trans-cinnamaldehyde (ca). the pac were subjected to thiolysis and hplc-ms analysis which demonstrated that t ...201526420588
tribendimidine: mode of action and nachr subtype selectivity in ascaris and oesophagostomum.the cholinergic class of anthelmintic drugs is used for the control of parasitic nematodes. one of this class of drugs, tribendimidine (a symmetrical diamidine derivative, of amidantel), was developed in china for use in humans in the mid-1980s. it has a broader-spectrum anthelmintic action against soil-transmitted helminthiasis than other cholinergic anthelmintics, and is effective against hookworm, pinworms, roundworms, and strongyloides and flatworm of humans. although molecular studies on c. ...201525679515
anthelmintic efficacy of ivermectin and abamectin, administered orally for seven consecutive days (100 µg/kg/day), against nematodes in naturally infected pigs.the present study aimed to evaluate ivermectin and abamectin, both administered orally in naturally infected domestic swine, as well as analysing if the epg (eggs per gram of faeces) values were equivalent with the ivermectin and abamectin efficacy obtained by parasitological necropsies. the animals were randomly selected based on the average of three consecutive epg counts of strongylida, ascaris suum and trichuris for experiment i, and of strongylida and trichuris for experiment ii. after the ...201425278142
the conqueror worm: recent advances with cholinergic anthelmintics and techniques excite research for better therapeutic drugs.the following account is based on a review lecture given recently at the british society of parasitology. we point out that nematode parasites cause very widespread infections of humans, particularly in economically underdeveloped areas where sanitation and hygiene are not adequate. in the absence of adequate clean water and effective vaccines, control and prophylaxis relies on anthelmintic drugs. widespread use of anthelmintics to control nematode parasites of animals has given rise to the deve ...201524871674
parasitic helminths of the digestive system of wild boars bred in captivity.this study aimed to identify the parasites that inhabit the digestive system of sus scrofa scrofa from a commercial breeding facility in southern brazil, and reports the first occurrence of trichostrongylus colubriformis in wild boars. the gastrointestinal tracts of 40 wild boars from a commercial breeding facility were collected and individualized during slaughter in a cold-storage slaughterhouse. out of this total, 87.5% were parasitized by the helminths ascaris suum, trichostrongylus colubrif ...201324142179
efficacy of ivermectin and oxfendazole against taenia solium cysticercosis and other parasitoses in naturally infected pigs.smallholder semi-confined pig production is a fast growing practice in sub-saharan africa with an unfortunate outcome of high prevalence of taenia solium cysticercosis and other parasitoses. the widely used anthelmintic for control of endo and ecto-parasites in pigs in the area is ivermectin at a recommended dose of 0.3mg/kg. this study was conducted to evaluate the efficacy and safety in pigs after subcutaneous injection of ivermectin (ivm, 0.3mg/kg) and orally administration of oxfendazole (of ...201323806569
identification and characterization of new major sperm protein genes from oesophagostomum dentatum and oesophagostomum quadrispinulatum from pigs in china.the present study identified and characterized new major sperm protein (msp) genes from the two nodule worms oesophagostomum dentatum and oesophagostomum quadrispinulatum collected from pigs in china. total genomic dna was extracted individually from 10 male nematode samples representing o. dentatum, and 4 male nematode samples representing o. quadrispinulatum. a pair of primers (omsp1f/msp1r) was designed based on the msp gene sequences of ascaris suum and o. dentatum available in genbank, and ...201323206956
galactosylated fucose epitopes in nematodes: increased expression in a caenorhabditis mutant associated with altered lectin sensitivity and occurrence in parasitic species.the modification of α1,6-linked fucose residues attached to the proximal (reducing-terminal) core n-acetylglucosamine residue of n-glycans by β1,4-linked galactose ("galfuc" epitope) is a feature of a number of invertebrate species including the model nematode caenorhabditis elegans. a pre-requisite for both core α1,6-fucosylation and β1,4-galactosylation is the presence of a nonreducing terminal n-acetylglucosamine; however, this residue is normally absent from the final glycan structure in inv ...201222733825
effect of vacuum packing and temperature on survival and hatching of strongyle eggs in faecal samples.strongyle eggs of helminths of livestock usually hatch within a few hours or days after deposition with faeces. this poses a problem when faecal sampling is performed in the field. as oxygen is needed for embryonic development, it is recommended to reduce air supply during transport and refrigerate. the present study therefore investigated the combined effect of vacuum packing and temperature on survival of strongyle eggs and their subsequent ability to hatch and develop into l3. fresh faecal sa ...201626827855
transcriptome analysis of a parasitic clade v nematode: comparative analysis of potential molecular anthelmintic targets in cylicostephanus goldi.clade v nematodes comprise several parasitic species that include the cyathostomins, primary helminth pathogens of horses. next generation transcriptome datasets are available for eight parasitic clade v nematodes, although no equine parasites are included in this group. here, we report next generation transcriptome sequencing analysis for the common cyathostomin species, cylicostephanus goldi. a cdna library was generated from rna extracted from 17 c. goldi male and female adult parasites. foll ...201323911309
gastrointestinal helminths of wild hogs and their potential livestock and public health significance in investigation into the potential for transmission of gastrointestinal helminths from wild hogs to livestock and humans was prompted by concerns of recreational wild-hog hunting in the caribbean region and the recent practice, by livestock farmers in jamaica, of co-rearing wild and domesticated swine. thirty-one wild hogs from the hellshire hills, a dry limestone forest in southern jamaica, were necropsied during the period june 2004 to august 2006. thirteen of the captured animals were male a ...201626821705
the complete mitochondrial genomes of oesophagostomum asperum and oesophagostomum columbianum in small ruminants.oesophagostomum spp., commonly known as 'nodule worms', is one of the important emerging nematode zoonoses worldwide. in the present study, we sequenced the complete mitochondrial (mt) genomes of two small ruminant nodule worms, oesophagostomum asperum and oesophagostomum columbianum, and compared them with that of pig nodule worms (oesophagostomum dentatum and oesophagostomum quadrispinulatum). the complete mt genomes of o. asperum ando. columbianum were 13,672 and 13,561 bp, respectively. both ...201323891666
gender and developmental specific n-glycomes of the porcine parasite oesophagostomum dentatum.the porcine nodule worm oesophagostomum dentatum is a strongylid class v nematode rather closely related to the model organism caenorhabditis elegans. however, in contrast to the non-parasitic c. elegans, the parasitic o. dentatum is an obligate sexual organism, which makes both a gender and developmental glycomic comparison possible.201727751954
recent advances in elucidating nematode moulting - prospects of using oesophagostomum dentatum as a model.there are major gaps in our knowledge of many molecular biological processes that take place during the development of parasitic nematodes, in spite of the fact that understanding such processes could lead to new ways of treating and controlling parasitic diseases via the disruption of one or more biological pathways in the parasites. progress in genomics, transcriptomics, proteomics and bioinformatics now provides unique opportunities to investigate the molecular basis of key developmental proc ...201627015950
curiouser and curiouser: the macrocyclic lactone, abamectin, is also a potent inhibitor of pyrantel/tribendimidine nicotinic acetylcholine receptors of gastro-intestinal worms.nematode parasites may be controlled with drugs, but their regular application has given rise to concerns about the development of resistance. drug combinations may be more effective than single drugs and delay the onset of resistance. a combination of the nicotinic antagonist, derquantel, and the macrocyclic lactone, abamectin, has been found to have synergistic anthelmintic effects against gastro-intestinal nematode parasites. we have observed in previous contraction and electrophysiological e ...201626751958
comparison of innate and th1-type host immune responses in oesophagostomum dentatum and trichuris suis infections in pigs.this study investigated the details of the innate and th1/treg-type-associated host immune responses in trichuris suis and oesophagostomum dentatum mono- and co-infected pigs and in vitro in stimulated porcine dendritic cell cultures. forty-eight pigs were allocated into a 2-factorial design with two groups trickle-inoculated with 10 t. suis eggs/kg/day (group t) or 20 o. dentatum l3/kg/day (o). another group (ot) was infected with both parasites. group c remained uninfected. expression of innat ...201626609699
immune and inflammatory responses in pigs infected with trichuris suis and oesophagostomum dentatum.the aim of the present study was to investigate parasite induced immune responses in pigs co-infected with trichuris suis and oesophagostomum dentatum as compared to mono-species infected pigs. t. suis is known to elicit a strong immune response leading to rapid expulsion, and a strong antagonistic effect on o. dentatum populations has been observed in co-infected pigs. forty-eight helminth naïve pigs were allocated into 4 groups in a 2-factorial design. two groups were trickle inoculated with e ...201525576439
assessment of the anthelmintic activity of medicinal plant extracts and purified condensed tannins against free-living and parasitic stages of oesophagostomum dentatum.plant-derived condensed tannins (ct) show promise as a complementary option to treat gastrointestinal helminth infections, thus reducing reliance on synthetic anthelmintic drugs. most studies on the anthelmintic effects of ct have been conducted on parasites of ruminant livestock. oesophagostomum dentatum is an economically important parasite of pigs, as well as serving as a useful laboratory model of helminth parasites due to the ability to culture it in vitro for long periods through several l ...201425406417
characterization of the intergenic spacer rdnas of two pig nodule worms, oesophagostomum dentatum and o. quadrispinulatum.the characteristics of the intergenic spacer rdnas (igs rdnas) of oesophagostomum dentatum and o. quadrispinulatum isolated from pigs in different geographical locations in mainland china were determined, and the phylogenetic relationships of the two species were reconstructed using the igs rdna sequences. the organization of the igs rdna sequences was similar to their organization in other eukaryotes. the 28s-18s igs rdna sequences of both o. dentatum and o. quadrispinulatum were found to have ...201425197691
proteomics elucidates key molecules involved in exsheathment in vitro in oesophagostomum dentatum.we explored molecules involved in in vitro exsheathment of oesophagostomum dentatum l3s using a proteomic-transcriptomic-bioinformatic approach. analysis of l3s before, during and after exsheathment identified 11 proteins that were over-expressed exclusively during exsheathment. these proteins (including key enzymes, heat shock, structural and nematode-specific proteins) were inferred to be involved in development, metabolism, structure, motility and/or host-parasite interactions. some of these ...201425036992
trichuris suis and oesophagostomum dentatum show different sensitivity and accumulation of fenbendazole, albendazole and levamisole in vitro.the single-dose benzimidazoles used against trichuris trichiura infections in humans are not satisfactory. likewise, the benzimidazole, fenbendazole, has varied efficacy against trichuris suis whereas oesophagostomum dentatum is highly sensitive to the drug. the reasons for low treatment efficacy of trichuris spp. infections are not known.201424699263
transcriptomic evaluation of the nicotinic acetylcholine receptor pathway in levamisole-resistant and -sensitive oesophagostomum dentatum.nematode anthelminthic resistance is widespread for the 3 major drug classes commonly used in agriculture: benzamidazoles, macrocyclic lactones, and nicotinic agonists e.g. levamisole. in parasitic nematodes the genetics of resistance is unknown other than to the benzimidazoles which primarily involve a single gene. in previous work with a levamisole resistant oesophagostomum dentatum isolate, the nicotinic acetylcholine receptor (nachr) exhibited decreased levamisole sensitivity. here, using a ...201424530453
investigation of acetylcholine receptor diversity in a nematode parasite leads to characterization of tribendimidine- and derquantel-sensitive nachrs.nicotinic acetylcholine receptors (nachrs) of parasitic nematodes are required for body movement and are targets of important "classical" anthelmintics like levamisole and pyrantel, as well as "novel" anthelmintics like tribendimidine and derquantel. four biophysical subtypes of nachr have been observed electrophysiologically in body muscle of the nematode parasite oesophagostomum dentatum, but their molecular basis was not understood. additionally, loss of one of these subtypes (g 35 ps) was fo ...201424497826
nodule worm infection in humans and wild primates in uganda: cryptic species in a newly identified region of human transmission.soil-transmitted helminths (sths) are a major health concern in tropical and sub-tropical countries. oesophagostomum infection is considered endemic to west africa but has also been identified in uganda, east africa, among primates (including humans). however, the taxonomy and ecology of oesophagostomum in uganda have not been studied, except for in chimpanzees (pan troglodytes), which are infected by both o. bifurcum and o. stephanostomum.201424421915
parasite population dynamics in pigs infected with trichuris suis and oesophagostomum dentatum.the aim of the present study was to investigate the population dynamics and potential interactions between trichuris suis and oesophagostomum dentatum in experimentally co-infected pigs, by quantification of parasite parameters such as egg excretion, worm recovery and worm location. forty-eight helminth naïve pigs were allocated into four groups. group o was inoculated with 20 o. dentatum l3/kg/day and group t with 10 t. suis eggs/kg/day. group ot was inoculated with both 20 o. dentatum l3/kg/da ...201424126087
oesophagostomum dentatum extract modulates t cell-dependent immune responses to bystander antigens and prevents the development of allergy in third of the human population is currently infected by one or more species of parasitic helminths. certain helminths establish long-term chronic infections resulting in a modulation of the host's immune system with attenuated responsiveness to "bystander" antigens such as allergens or vaccines. in this study we investigated whether parasite-derived products suppress the development of allergic inflammation in a mouse model. we show that extract derived from adult male oesophagostomum dentatu ...201323844022
computational cloning of drug target genes of a parasitic nematode, oesophagostomum dentatum.gene identification and sequence determination are critical requirements for many biological, genomic, and bioinformatic studies. with the advent of next generation sequencing (ngs) technologies, such determinations are predominantly accomplished in silico for organisms for which the genome is known or for which there exists substantial gene sequence information. without detailed genomic/gene information, in silico sequence determination is not straightforward, and full coding sequence determina ...201323773280
proteomic analysis of oesophagostomum dentatum (nematoda) during larval transition, and the effects of hydrolase inhibitors on this study, in vitro drug testing was combined with proteomic and bioinformatic analyses to identify and characterize proteins involved in larval development of oesophagostomum dentatum, an economically important parasitic nematode. four hydrolase inhibitors ο-phenanthroline, sodium fluoride, iodoacetamide and 1,2-epoxy-3-(pnitrophenoxy)-propane (epnp) significantly inhibited (≥90%) larval development. comparison of the proteomic profiles of the development-inhibited larvae with those of unin ...201323717515
sequence variability in three mitochondrial genes between the two pig nodule worms oesophagostomum dentatum and o. this study, sequence variation in three mitochondrial dna regions, namely cytochrome c oxidase subunit (cox1) and nadh dehydrogenase subunits 1 and 4 (nad1 and nad4), between oesophagostomum dentatum and o. quadrispinulatum isolated from pigs in different geographical origins in mainland china was examined, and their phylogenetic relationships were reconstructed. a partial of the cox1 (pcox1), nad1, and nad4 genes (pnad1 and pnad4) were amplified separately from individual nodule worms by pcr ...201222651230
oesophagostomum dentatum and oesophagostomum quadrispinulatum: characterization of the complete mitochondrial genome sequences of the two pig nodule the present study, the complete mitochondrial dna (mtdna) sequences of the pig nodule worm oesophagostomum quadrispinulatum were determined for the first time, and the mt genome of oesophagostomum dentatum from china was also sequenced for comparative analysis of their gene contents and genome organizations. the mtdna sequences of o. dentatum china isolate and o. quadrispinulatum were 13,752 and 13,681 bp in size, respectively. each of the two mt genomes comprises 36 genes, including 12 prote ...201222414328
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