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PubMedDate not supplied

A report of the first case of Dirofilaria infection in the eyelid region in Japan.

Dirofilaria worms were recovered from a painless hard tumor in the right eyelid of a 19-year-old Japanese male who had lived in Kagoshima and Kumamoto Prefectures, Japan. In the worms, the cuticle had a smooth surface, the inner cuticular layer had internal lateral longitudinal ridges, and the musculature of the body wall was the polymyarian type. On the basis of all morphological characteristics observed, this worm was identified as an immature female Dirofilaria immitis. This is the first human case of nematode infection in the eyelid in Japan. Surgical removal of the mass with worms resulted in complete recovery from swelling of his right eyelid.

Adult↗
PubMed1998

Phylogeny of nematode-trapping fungi based on 18S rDNA sequences.

The small subunit (SSU) ribosomal DNA (18S rDNA) from 15 species of nematode-trapping fungi and closely related non-parasitic species were sequenced. Phylogenetic analysis indicated that species within the genera of Arthrobotrys, Dactylaria, Dactylella, Monacrosporium and Duddingtonia formed a monophyletic and isolated clade among an unresolved cluster of apothecial ascomycetes. The phylogenetic patterns within this clade were not concordant with the morphology of the conidia nor the conidiophores, but rather with that of the infection structures. The results from the different methods of tree reconstruction supported three lineages; the species having constricting rings, the non-parasitic species and the species having various adhesive structures (nets, hyphae, knobs and non-constricting rings) to infect nematodes.

Animals↗
PubMed2005

Evaluation of efficacy of entomopathogenic nematodes against larvae of Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae).

The blowfly Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) is the primary agent of cutaneous myiasis of sheep in northern Europe, southern Africa, Australia and New Zealand. As the application of chemicals has several disadvantages, alternative control measures of traumatic myiasis of livestock must be developed. In this study, the use of entomopathogenic nematodes (EPNs) as potential biocontrol agents against second instar larvae of Lucilia sericata was considered. The following nematode species were tested: Heterorhabditis bacteriophora (IS 5, HHU 1, Hmol, HNC 1, HAZ 36, Hbrecon, HHU 2, HAZ 29, HHP 88, HHU 3, HHU 4 and HGua), Steinernema intermedia, NC513 strain of S. glaserii, S. anomali, S. riobrave, Steinernema sp. and 5 strains of S. feltiae (22, Vija Norway, HU 1, scp, and IS 6). None of the examined EPN species or strains showed larvicidal efficacy at 37 degrees C (no killing effect was observed in the case of the two heat-tolerant strains--H. bacteriophora and S.feltiae) against L. sericata larvae. At lower temperatures (20 degrees C and 25 degrees C) only strains of S. feltiae were found to be active. The overall odds ratios calculated for L. sericata maggots to contract S. feltiae nematode infection show significant (p < 0.05) effect only in the case of strains HU 1, 22 and IS 6. In the case of strains HU 1 and 22 parasitic forms of S. feltiae could be detected in the dead larvae of L. sericata. Strain IS 6 (and also Vija Norway at 20 degrees C) penetrated and killed fly larvae, but only adult forms of the nematode occurred in the cadavers.

Animals↗
PubMed2003

Methods to sustain drug efficacy in helminth control programmes.

Assessment of the efficacy of anthelminthic treatment in public health is a broad concept, which goes beyond parasitological methods and should be clearly defined according to several indicators of morbidity. Several factors may influence the efficacy of anthelminthic drugs. The quality of drug is an issue of great importance, especially when produced locally as a generic product and used in large-scale chemotherapy-based control programmes. Other factors include the drug-patient interaction, the host-parasite relationship, the diagnostic method used, genetic variations between parasite strains and induced drug resistance. Veterinary scientists have warned that drug resistance can be selected through frequent mass treatment of sheep and goats and have developed a body of knowledge on evaluation of efficacy and detection of resistance in nematodes of veterinary importance. In soil-transmitted nematodes infections of humans, the egg reduction rate (ERR), the egg hatch assay (EHA) and novel molecular biological techniques may be used to monitor drug efficacy in helminth control programmes and to detect early occurrence of resistance. Evidence of reduced drug efficacy of some anthelminthics has been suggested by recent studies and strategies to prevent or delay the emergence of drug resistance in human soil-transmitted nematodes.

Animals↗
PubMed1981

Experimental cross-infections with gastrointestinal nematodes of sheep and cattle.

Five parasite-free lambs and five parasite-free calves were infected experimentally with 20,000 third stage gastrointestinal nematode larvae cultured from faeces of sheep from five different farms. In the same way five lambs and five calves were infected with larvae cultured from faeces of calves from five different farms. Host specificity of the nematodes was determined using the following parameters: infection rate; number, size, and stage of the worms; their distribution within the gastrointestinal tract; and the onset, duration, and level of egg production. The conclusions with regard to the different species are: Almost exclusively in cattle Skrjabinagia lyrata Strongly adapted to cattle Ostertagia ostertagi More adapted to cattle than to sheep Cooperia oncophora, C. surnabada, C. punctata, Trichostrongylus longispicularis No special host preference T. axei, O. leptospicularis, S. kolchida More adapted to sheep than to cattle C. curticei, T. vitrinus, T. colubriformis, O. trifurcata, Teladorsagia davtiani, Haemonchus contortus, Strongyloides papillosus Strongly adapted to sheep O. circumcincta, Oesophagostomum venulosum, Almost exclusively in sheep Chabertia ovina.

Animals↗
PubMed1997

Role of nitric oxide in norepinephrine release from myenteric plexus in vitro and in Trichinella spiralis-infected rats.

Nitric oxide (NO) has been implicated as modulator of neural function and inflammatory mediator. Previously, we have demonstrated suppression of norepinephrine (NE) release from myenteric nerves following Trichinella spiralis infection implicating interleukin-1 beta (IL-1 beta) as a mediator of these changes. In the present study, we have examined the role of NO in NE release from the myenteric plexus and in the suppression of NE release induced by IL-1 beta in vitro, and we have determined whether NO is involved in the suppression of NE release from the myenteric plexus observed in T. spiralis-infected rats. Electrically evoked NE release from jejunal longitudinal muscle-myenteric plexus preparations (LMMP) was measured following (a) in vitro exposure of the tissue to the NO donor 3-morpholinosydnonimine (SIN-1), L-arginine, or IL-1 beta, in the presence or absence of NOS inhibitors, and (b) in vivo treatment of control or T. spiralis-infected rats with N6-nitro-L-arginine-methyl-ester (L-NAME), NG-nitro-D-arginine-methyl-ester (D-NAME) or vehicle for 6 days. In vitro inhibition of NO synthesis had no effect on NE release from the myenteric plexus. Treatment with SIN-1 or L-arginine suppressed NE release in a manner similar to that observed with IL-1 beta. Moreover, the effect of IL-1 beta was attenuated by L-NAME. In contrast, treatment of T. spiralis-infected rats with L-NAME had no effect on the suppression of NE release. These results indicate that in the absence of inflammation, the myenteric plexus can generate sufficient NO to inhibit NE release and that NO mediates the action of IL-1 beta on NE release in vitro. However, we have no evidence for the involvement of NO in the suppression of NE release in nematode-infected rats.

Animals↗
PubMed2001

Fructosamine concentration and resistance to natural, predominantly Teladorsagia circumcincta infection.

Fructosamine concentrations reflect protein status and because infection with Teladorsagia circumcincta can induce a relative protein deficiency, we examined the usefulness of fructosamine concentrations as markers of the intensity of infection in naturally infected lambs. Fructosamine concentration was a heritable trait and variation in fructosamine concerntrations was associated with differences in body weight, and a variety of parasitological variables; animals with increased fructosamine concentrations grew more quickly, had increased faecal egg counts in one of the three study years, had decreased pepsinogen concentrations and decreased IgA activity against 4th-stage larvae of T. circumcincta. Fructosamine concentrations were also associated with variation in the subsequent acquisition of nematodes and in the length of adult female T. circumcincta; lambs with increased fructosamine concentrations had fewer nematodes but the mean length of adult female T. circumcincta was longer. Therefore fructosamine concentrations are potentially useful indicators of the severity of nematode infection and may predict magnitude of subsequent infection.

Abomasum↗
PubMed1994

Genetic control of the antibody repertoire against excretory/secretory products and acetylcholinesterases of Dictyocaulus viviparus.

Outbred Dunkin-Hartley and inbred strain 2 and strain 13 guinea pigs were immunized with Dictyocaulus viviparus adult ES products prior to challenge with third stage larvae. Antibody responses of the three strains to adult ES products and the acetylcholinesterase (AChE) isoforms which they contain were examined. Using immunoprecipitation and ELISA, it was observed that responses in the three strains to adult ES products were distinct: considerable heterogeneity in the antibody repertoire was observed between outbred Dunkin-Hartley animals, with only slight variation occurring amongst the inbred individuals. Responses to the AChE isoforms were heterogeneous amongst individual outbred guinea pigs but were more consistent in inbred strain 2 and 13 animals in which strain-specific patterns of recognition were observed. Previous studies with nematode infections have indicated a role for the major histocompatibility complex in determining the nature and level of the immune response. As the inbred strains bear different alleles at the Class II region but are identical at the Class I region, the differences observed are likely to be due to genes mapping to the Class II locus. This is therefore the first report of genetic restriction of the antibody repertoire to secreted AChEs of a parasitic nematode.

Acetylcholinesterase↗
PubMed2000

Conversion of compatible plant-pathogen interactions into incompatible interactions by expression of the Pseudomonas syringae pv. syringae 61 hrmA gene in transgenic tobacco plants.

The hrmA gene from Pseudomonas syringae pv. syringae has previously been shown to confer avirulence on the virulent bacterium P. syringae pv. tabaci in all examined tobacco cultivars. We expressed this gene in tobacco plants under the control of the tobacco Delta0. 3 TobRB7 promoter, which is induced upon nematode infection in tobacco roots (Opperman et al. 1994, Science, 263, 221-223). A basal level of hrmA expression in leaves of transgenic plants activated the expression of pathogenesis-related genes, and the transgenic plants exhibited high levels of resistance to multiple pathogens: tobacco vein mottling virus, tobacco etch virus, black shank fungus Phytophthora parasitica, and wild fire bacterium Pseudomonas syringae pv. tabaci. However, the hrmA transgenic plants were not significantly more resistant to root-knot nematodes. Our results suggest a potential use of controlled low-level expression of bacterial avr genes, such as hrmA, in plants to generate broad-spectrum resistance to bacterial, fungal and viral pathogens.

Animals↗
PubMed2005

Recruitment of entomopathogenic nematodes by insect-damaged maize roots.

Plants under attack by arthropod herbivores often emit volatile compounds from their leaves that attract natural enemies of the herbivores. Here we report the first identification of an insect-induced belowground plant signal, (E)-beta-caryophyllene, which strongly attracts an entomopathogenic nematode. Maize roots release this sesquiterpene in response to feeding by larvae of the beetle Diabrotica virgifera virgifera, a maize pest that is currently invading Europe. Most North American maize lines do not release (E)-beta-caryophyllene, whereas European lines and the wild maize ancestor, teosinte, readily do so in response to D. v. virgifera attack. This difference was consistent with striking differences in the attractiveness of representative lines in the laboratory. Field experiments showed a fivefold higher nematode infection rate of D. v. virgifera larvae on a maize variety that produces the signal than on a variety that does not, whereas spiking the soil near the latter variety with authentic (E)-beta-caryophyllene decreased the emergence of adult D. v. virgifera to less than half. North American maize lines must have lost the signal during the breeding process. Development of new varieties that release the attractant in adequate amounts should help enhance the efficacy of nematodes as biological control agents against root pests like D. v. virgifera.

Animals↗
PubMed1994

Application of an immunocolloid gold technique for the ultrastructural demonstration of IgE-receptor complexes on rat mast cells.

In previous works using cytofluorometry, we demonstrated a broad range of IgE and IgE-receptor levels within individual mast cell populations with a 60 to 80% occupancy of the IgE receptors on mast cells by native IgE. This study was performed in order to confirm our previous findings using an independent method and to visualize the distribution of IgE-receptor complexes on mast cells at an ultrastructural level. For this purpose an indirect immunocolloidal gold-labelling technique has been applied. By counting the number of labelled gold particles, a relative measure of IgE-receptor surface expression and IgE occupancy of the receptors could be obtained. With respect to mast cell morphology and anti-IgE binding specificity criteria, 1% glutaraldehyde + 4% paraformaldehyde (1:1, vol/vol) was found to be the best of the seven fixatives applied in this study. This technique revealed numerous gold particles on the surface of mast cells from barrier-maintained rats (26 +/- 11 per mast cell section, mean +/- SD). Increased numbers of gold particles were counted if the mast cells were incubated with rat myeloma IgE (20 micrograms/ml) (46 +/- 33 per mast cell section, mean +/- SD). There were significantly increased numbers of gold particles on the mast cells of rats infected with N. brasiliensis (126 +/- 30 per mast cell section, mean +/- SD). This indicates that some of the IgE receptors (about 50% of the total number of IgE receptors in this case) on mast cells were occupied by native IgE and that parasite infection significantly increased the number of IgE molecules on the surface of the mast cells. These results correspond with the findings we have made using the cytofluorometric technique and confirm the large individual variations in the density of IgE receptors and IgE among the mast cells of a given cell population. Macrophages, lymphocytes and eosinophils, carrying the low-affinity IgE receptors (Fc epsilon RII), contained less than 5 (normal rats after incubation in rat IgE) or 10 (nematode-infected rats) gold particles per cell section. We also observed some non-granulated lymphocyte-like cells which bound a large number of gold particles after incubation with rat myeloma IgE (20 micrograms/ml), indicating that they contained IgE receptors Fc epsilon RI). They were interpreted as mast cell precursors which have previously been shown to exist in the peritoneal cavity.

Animals↗
PubMed1998

T lymphocyte-dependent and -independent intestinal smooth muscle dysfunction in the T. spiralis-infected mouse.

We examined the profile of increased intestinal muscle contractility after primary infection with Trichinella spiralis in the mouse, correlating it with parasite expulsion. We also examined the extent to which the changes in muscle contraction were T lymphocyte dependent, by infecting athymic and SCID mice. Infection was accompanied by increased tension development by intestinal muscle. Two components of this response were identified, a rapid peak increase in tension generation observed on day 6 postinfection, and a smaller but sustained increase in tension evident thereafter in euthymic BALB/c mice. The peak muscle response was significantly delayed in infected athymic and SCID mice, along with a corresponding reduction in the magnitude of the sustained component. These changes were accompanied by reduced parasite expulsion in athymic and SCID mice, compared with euthymic mice. Reconstitution of T cell function in athymic mice restored both the acute and sustained profile of muscle contraction seen in euthymic mice, and this was accompanied by faster expulsion of the worms. These results identify T cell-dependent and -independent components of the muscle response to nematode infection in the mouse and suggest that the onset of the peak contractile response, as well as the magnitude of the sustained muscle response, contributes to parasite eviction from the gut.

Animals↗
PubMed2006

Identification and analysis of genes expressed in the adult filarial parasitic nematode Dirofilaria immitis.

The heartworm Dirofilaria immitis is a filarial parasitic nematode infecting dogs and other mammals worldwide causing fatal complications. Here, we present the first large-scale survey of the adult heartworm transcriptome by generation and analysis of 4005 expressed sequence tags, identifying about 1800 genes and expanding the available sequence information for the parasite significantly. Brugia malayi genomic data offered the most valuable information to interpret heartworm genes, with about 70% of D. immitis genes showing significant similarities to the assembly. Comparative genomic analyses revealed both genes common to metazoans or nematodes and genes specific to filarial parasites that may relate to parasitism. Characterization of abundant transcripts suggested important roles for genes involved in energy generation and antioxidant defense in adults. In particular, we proposed that adult heartworm likely adopted an anaerobic electron transfer-based energy generation system distinct from the aerobic pathway utilized by its mammalian host, making it a promising target in developing next generation macrofilaricides and other treatments. Our survey provided novel insights into the D. immitis transcriptome and laid a foundation for further comparative studies on biology, parasitism and evolution within the phylum Nematoda.

Animals↗
PubMed1995

Investigation of cross-reactions against Trichinella spiralis antigens by enzyme-linked immunosorbent assay and enzyme-linked immunoelectrotransfer blot assay in patients with various diseases.

Data regarding cross-reactions against Trichinella spiralis in humans are scarce and controversial. For this reason, we tested serum samples from patients with typhoid fever, brucellosis, toxoplasmosis, amoebiasis, cysticercosis, trichocephaliasis, ascariasis, and onchocerciasis against an antigenic extract of T. spiralis infective larvae in an enzyme-linked immunosorbent assay (ELISA) and an enzyme-linked immunoelectrotransfer blot (EITB) assay. All except one serum sample from the group of patients with onchocerciasis were negative in the ELISA; in the EITB assay, only faint bands were observed with the samples from patients with onchocerciasis and ascariasis and negative results were obtained with the samples from patients with other diseases. In conclusion, cross-reactions were found only in the groups of patients with other nematode infections and were of very low magnitude, most of them virtually negative.

Amebiasis↗
PubMed1981

Flubendazole and mebendazole in the treatment of trichuriasis and other helminthiases.

Forty patients were treated with either flubendazole or mebendazole, 100 mg twice a day for three days, in a double-blind, prospective, randomized study. The study concentrated on patients with Trichuris trichiura infections, although the effects of the anthelmintic agents on concomitant Ascaris lumbricoides and hookworm infections were also evaluated. Results from 35 evaluable patients showed complete cure in 17/19 (89%) patients treated with flubendazole and 15/16 (94%) patients treated with mebendazole (P less than 0.05, no significant difference). Significant reduction in Trichuris egg counts was noted in the three other patients. No significant adverse clinical or laboratory reactions were noted. Other roundworms were completely eradicated by both anthelmintic agents. Based on this study, flubendazole appears to be as effective and safe as mebendazole in the treatment of nematode infections.

Antinematodal Agents↗
PubMed1997

The strategic use of closantel and albendazole in controlling naturally acquired gastrointestinal nematodes of sheep in the Kenya highlands.

The strategic use of closantel, a narrow-spectrum salicylanilide anthelmintic against bloodsucking helminths, and of albendazole, a broad-spectrum benzimidazole anthelmintic, in the control of gastrointestinal nematodes of sheep was investigated on a farm in Nyandarua District in the highlands of Kenya. Thirty Corriedale female lambs aged between 9 and 12 months were assigned to three treatment groups of 10 lambs each. The three groups were set stocked on separate paddocks for 12 months. Lambs in group 1 (strategic treatment group) were treated with closantel and albendazole at the beginning and towards the end of the long rains (April and June, respectively) and towards the end of the short rains. (December). During the intervening dry season, the lambs were treated with albendazole. Lambs in group 2 (suppressive treatment group) were kept 'worm free' by regular deworming with albendazole at 3-weekly intervals for 12 months. The third group of lambs remained untreated (control group). Gastrointestinal nematode infections and pasture infectivity were well controlled in the case of the strategic treatment group. This resulted in higher weight gains, wool production, packed cell volume, and serum albumin and protein concentrations compared with the untreated control lambs. These parameters were comparable between the strategic treatment and the suppressive treatment groups of lambs. It was concluded that worm control strategies based on the epidemiology of the parasites and the sustained anthelmintic action of closantel in combination with broad-spectrum anthelmintics can provide effective control of gastrointestinal nematodes of sheep in the study area.

Albendazole↗
PubMed2001

Ileal mucosal mast cell, eosinophil, and goblet cell populations during Hymenolepis diminuta infection of the rat.

The population dynamics in the enteric connective tissues of eosinophils, mucosal mast cells (MMC), and in the mucosal epithelium of goblet cells were examined morphometrically in fixed ileal tissue of outbred Sprague Dawley rats during the first 32 days of infection with the tapeworm Hymenolepis diminuta. MMC and eosinophils were present in the lamina propria and submucosa; however, only eosinophils were also present in the muscularis externa. Eosinophilic infiltrate was first observed in the lamina propria at 15 days postinfection (dpi) and the numbers of eosinophils remained elevated through 32 dpi. Initial mucosal mastocytosis was detected on 6 dpi and MMC numbers continued to rise over the study period without reaching a plateau. Goblet cell hyperplasia occurred only at 32 dpi. In contrast to some intestinal nematode infections where these same 3 cell types are associated with the host's expulsion responses, H. diminuta is not lost by a rapid host response in the outbred Sprague Dawley rat strain used in these experiments. We suggest that either the induction of hyperplasia of these host effector cells in ileum tissue during H. diminuta infection is not capable of triggering parasite rejection mechanisms, or the function of the induced hyperplasia is necessary for some as yet unassociated physiological or tissue architecture change in the host's intestine.

Animals↗
PubMed1983

Genetic dependence of IgE antibody production in mice infected with the nematode Nippostronglyus brasiliensis. I. Modulation of the IgE antibody response in vivo by serum factors.

We investigated the IgE-antibody response in 36 inbred mouse strains during infection with Nippostrongylus brasiliensis. With regard to the N. brasiliensis-specific IgE-antibody activity responder and nonresponder mice were obtained. Mice with the H-2-f haplotype (A.CA, B10.M, A.TFR 5) are high specific responders. It is suggested that one Ir gene for the N. brasiliensis-induced IgE-antibody response is localized within the K to J region of the mouse major histocompatibility complex. To obtain a medium IgE-antibody response it appears that a complementation between two Ir genes is necessary. An additional genetic control beyond the H-2 complex cannot be excluded. As to the total nonspecific serum IgE levels the parasitic infection leads to a 20- to 40-fold increase in high and low specific responder strains as well. Pretreatment of high responder mice (A.TFR 5, B10.M) with sera that were obtained from normal or complete Freund's adjuvant treated low (B10.G) and nonresponder (A.TFR 1) mice led to significant inhibition or enhancement of the N. brasiliensis-specific IgE-antibody response.

Animals↗