Effects Of Nematode Infection Research Articles

Nematode-Induced Growth Factors Related to Angiogenesis in Autoimmune Disease Attenuation.

Accumulating data suggest an important role of growth factors in autoimmune diseases and parasitic nematode infections. Nematodes are used in clinical studies of autoimmune diseases and parasite-derived molecules are widely studied for their therapeutic potential in various types of disorders. However, the effect of nematode infection on growth factors in autoimmune disorders has not been studied. The objective of this study was to evaluate the influence of infection with the intestinal nematode Heligmosomoides polygyrus in murine autoimmune models on the production of growth factors. Here, the level of a variety of growth factors related mainly to angiogenesis was evaluated by protein array in the intestinal mucosa of C57BL/6 dextran sodium sulfate-induced colitic mice and in cerebral spinal fluid of experimental autoimmune encephalomyelitis (EAE) mice infected with nematodes. In addition, vessel formation was evaluated in the brains of EAE mice infected with H. polygyrus. A significant influence of nematode infection on the level of angiogenic factors was observed. Parasitic infection of colitic mice resulted in upregulation of mucosal AREG, EGF, FGF-2, and IGFBP-3 in the intestine of the host and better adaptation (infectivity). In EAE mice, infection increased the level of FGF-2 and FGF-7 in CSF. In addition, remodeling of brain vessels was observed, with a higher density of long vessels. Nematode-derived factors are promising tools to fight autoimmune diseases and to study angiogenesis.

Planting Material of Enset (Ensete ventricosum), a Key Food Security Crop in Southwest Ethiopia, Is a Key Element in the Dissemination of Plant-Parasitic Nematode Infection.

Enset (Ensete ventricosum), is a perennial herbaceous plant belonging to the family Musaceae, along with banana and plantain. Despite wild populations occurring in eastern, central and southern Africa, it is only in Ethiopia that the crop has been domesticated, where it is culturally and agriculturally symbolic as a food security crop. Although an under-researched orphan crop, enset serves as a staple food for about 20% of the Ethiopian population, comprising more than 20 million people, demonstrating its value in the country. Similar to banana and plantain, enset is heavily affected by plant-parasitic nematodes, with recent studies indicating record levels of infection by the root lesion nematode Pratylenchus goodeyi. Enset is propagated vegetatively using suckers that are purposely initiated from the mother corm. However, while banana and plantain suckers have proven to be a key source of nematode infection and spread, knowledge on the infection levels and role of enset suckers in nematode dissemination is lacking. Given the high levels of plant-parasitic nematodes reported in previous surveys, it is therefore speculated that planting material may act as a key source of nematode dissemination. To address this lack of information, we assessed enset planting material in four key enset growing zones in Ethiopia. A total of 340 enset sucker samples were collected from farmers and markets and analyzed for the presence of nematodes. Nematodes were extracted using a modified Baermann method over a period of 48 h. The root lesion nematode P. goodeyi was present in 100% of the samples, at various levels of infection. These conclusive results show that planting material is indeed a key source of nematode infection in enset, hence measures taken to ensure clean suckers for planting will certainly mitigate nematode infection and spread. The effect of nematode infection on yield and quality on enset remains to be investigated and would be a way forward to complement the nematode/disease studies conducted so far and add valuable knowledge to the current poorly known impact of pests and diseases.

Comparison of intestinal microbes in female and male Chinese concave-eared frogs (Odorrana tormota) and effect of nematode infection on gut bacterial communities.

The Chinese concave‐eared frog (Odorrana tormota) is a rare and threatened species with remarkable sexual dimorphism. Intestinal microbes are understood to play important roles in animal physiology, growth, ecology, and evolution. However, little is known about the intestinal microbes in female and male frogs, as well as the contributing effect by gut infesting nematodes to the co‐habiting bacteria and their function in degradation food rich in chitin. Here, this study analyzed the microbiota of the intestinal tract of both female and male, healthy as well as nematode‐infested concave‐eared frogs using high throughput 16S rRNA sequencing and metagenomic techniques. The results showed that the bacterial composition of the microbiota at the phylum level was dominated by Firmicutes, Verrucomicrobia, Bacteroidetes, and Proteobacteria. The study also revealed that the community composition below the class level could be represent sex differences, particularly with regard to Enterobacteriales, Enterobacteriaceae, Peptostreptococcaceae, and Rikenellaceae, among others. Carbohydrate‐active enzyme‐encoding genes and modules were identified in related gut bacteria by metagenomic analysis, with Bacteroidia, Clostridia, and gammaproteobacteria predicted to be the main classes of chitin‐decomposing bacteria in the frog intestine. In addition, the abundance of some bacteria significantly increased or decreased in nematode‐infected hosts compared with healthy individuals, including Verrucomicrobia, Verrucomicrobiae, Negativicutes, Actinobacteria, and Bacilli, among others. This indicates that nematode infection may affect the richness and composition of some gut bacteria.

Effects of nematode infection on contents of phenolic substances as influenced by root-knot nematode,Meloidogyne incognitain susceptible and resistant brinjal cultivars

The variation in total phenolic substances in three brinjal cultivars i.e Pusa Kranti (R), Kantabaigan (R) and Pusa Purple Long(S) were studied 45 days after inoculation of Meloidogyne incognita. The total phenolic substances in the roots of both healthy and resistant cultivars was higher compared to the susceptible cultivars. However, in the inoculated plants the total phenolic substances in two resistant variety varied from 0.488 to 0.782 mg/g as compared to susceptible variety (0.687 mg/g). An increasing trend was also observed in the phenolic contents in the roots of inoculated susceptible and resistant cultivars.

Role of Altered Intestinal Function in the Protective Effects of Nematode Infection Against the Development of Type 1 Diabetes (T1d) in Non Obese Diabetic (NOD) Mice

SPM 8 was applied to test anatomical regions of interest in the pINS, aINS and the aMCC while maintaining a family-wise error rate at p<.05. We also tested the possible effects of gut distension on processing speed and cognitive performance, indexed by mean reaction time and accuracy.Results:Subliminal or supraliminal gut distention during performance of the high or low processing load task did not significantly increase activity in pINS or aINS. However, during the high cognitive load task,supraliminal distension resulted in a reduction of aMCC activity. As expected, reaction time was longer during the high processing load compared to the low processing load task. However,subliminal and supraliminal balloon inflation did not alter reaction time or accuracy rates on the task. Conclusions:In healthy participants: 1)When attention is focused away from the gut, subliminal andmildly supraliminal rectal distension is not associated with activation of the primary interoceptive cortex, while supraliminal distension is associated with a reduction of aMCC activity during a high processing load task. These findings are consistent with possible engagement of descending inhibitory systems during the attention task, reducing interoceptive inflow to the brain.2) Low intensity visceral stimulation does not interfere with cognitive performance.

Effects of nematode infection on anorexia and leptin levels in lambs of two breeds

Effects of nematode infection on anorexia and leptin levels in lambs of two breeds

Intestinal helminthes and/or Toxocara infection are unrelated to anti-HBs titers in seven-year-old children vaccinated at birth with recombinant hepatitis B vaccine

The aim of this investigation was to evaluate the possible effect of nematode infection on anti-HBs antibody levels in the serum of seven-year-old schoolchildren vaccinated at birth with the recombinant hepatitis B vaccine. Anti-HBs and anti HBc antibodies were evaluated in the sera of 100 schoolchildren with at least one intestinal nematode and/or a positive serological reaction for anti-Toxocara antibodies and in 95 schoolchildren without intestinal helminthiasis or serum anti-Toxocara antibodies. Both groups were from public elementary schools located on the urban periphery of Vitória, ES, Brazil. Among these 195 children, the median anti-HBs antibody titer was 31.3 IU/ml and the frequency of titers less than 10 IU/ml was 33.8% (95% CI: 27.1-40.4%). There were no significant differences between the medians of anti-HBs titers or the frequency of titers less than 10 IU/ml between the groups with or without helminthes (29.5 and 32.9 IU/ml and 33 and 34.7%, respectively; p>0.05). Even when the children with intestinal nematodes and/or anti-Toxocara antibodies and with blood eosinophil counts over 600/mm(3) were compared with children without infection from intestinal nematodes and without anti-Toxocara antibodies, with blood eosinophil counts less than 400 eosinophils/mm(3), these differences were not significant. None of the children presented anti-HBc antibodies. In conclusion, infections with intestinal nematodes and/or the presence of anti-Toxocara antibodies did not interfere with the anti-HBs antibody titers in seven-year-old children vaccinated at birth with the recombinant hepatitis B vaccine.

Pharmacological and Pharmacokinetic Aspects of Functional Gastrointestinal Disorders

Medications are commonly used for the treatment of patients with functional gastrointestinal disorders. The general goal of this report is to review the pharmacokinetics and pharmacology of medications used in functional gastrointestinal disorders. Methods included literature review, consensus evaluation of the evidence for each topic assigned originally to 1 or 2 authors, and broader review at a harmonization session as part of the Rome III process. This report reviews the animal models that have been validated for the study of effects of pharmacologic agents on sensation and motility; the preclinical pharmacology, pharmacokinetics, and toxicology usually required for introduction of novel therapeutic agents; the biomarkers validated for studies of sensation and motility end points with experimental medications in humans; the pharmacogenomics applied to these medications and disorders; and the pharmacology of agents that are applied or have potential for treatment of functional gastrointestinal disorders, including psychopharmacologic agents. Clinician and basic investigators involved in the treatment or investigation of functional gastrointestinal disorders or disease models need to have a comprehensive understanding of a vast range of medications. It is anticipated that the interaction between investigators of basic science, basic and applied pharmacology, and clinical trials will lead to better treatment of these disorders.

Effect of nematode infection and damage on the root system and plant growth of three Musa cultivars commonly grown in Uganda

AbstractBanana production in East Africa is threatened by declining yields partly caused by plant-parasitic nematodes. Attempts to ameliorate this damage are hampered by a lack of information on the characteristics of the root systems of healthy and nematode infested roots of commonly grown banana cultivars. An experiment in hydroponic culture, where healthy root systems were established, demonstrated that there were differences in number, size and distribution of primary, secondary and tertiary roots among the cultivars Nabusa, Pisang Awak and Sukali Ndizi. Field experiments carried out at three sites in Uganda showed that nematode damage on the same cultivars increased the number of primary roots and root bases, either increased or decreased root length depending on the cultivar or nematode species involved, but always decreased root length density. Root number and size are probably critical factors in determining plant tolerance to nematodes. Our findings should help plant breeding programmes, which must establish those selection criteria that are most likely to reduce the debilitating effects of nematode damage.

Effects of nematode infection and mulching on the yield of plantain (Musa spp., AAB-group) ratoon crops and plantation longevity in southeastern Nigeria

AbstractThe effects of nematode infection and mulching on plantain cv. Agbagba (Musa spp., AAB-group, false horn) yield and plantation longevity were examined in a field experiment at the High Rainfall Station of the International Institute of Tropical Agriculture (IITA) at Onne in southeastern Nigeria. The 2nd, 3rd and 4th crop cycles (1st, 2nd and 3rd ratoon, respectively) following the plant crop cycle (mother crop) were examined in nematode inoculated or non-inoculated and mulched or non-mulched treatments. Nematodes (Radopholus similis, Helicotylenchus multicinctus and, to a lesser extent, Helicotylenchus dihystera, Hoplolaimus pararobustus and Meloidogyne spp.) were inoculated at planting of the mother plant, but were also present in relatively high population densities in the non-inoculated treatments at harvest of the 1st crop cycle. Plants inoculated with nematodes failed to reach harvest and neither did plants in the non-inoculated non-mulched treatments in any ratoon. Only non-inoculated mulched plants reached harvest, producing 0.85, 1.22 and 0.2 Mg ha−1, respectively in the 1st, 2nd and 3rd ratoon, taking toppled, broken and dead plants into consideration. Mulched plants were larger, had more suckers, survived longer and had healthier root systems compared with non-mulched plants. Damage to roots was greater in the inoculated plants compared with the non-inoculated plants for the 1st and 2nd ratoons but not for the 3rd ratoon. Radopholus similis was most strongly associated with root damage (percentage root necrosis and dead roots), although H. multicinctus population densities were also positively correlated with percentage root necrosis. At flowering of the 1st ratoon, 71% of the inoculated non-mulched plants were dead compared with only 1% of the non-inoculated mulched plants. Helicotylenchus multicinctus remained the most abundant nematode throughout the experiment. Together with R. similis, it comprised over 95% of the plant-parasitic nematode population.

Neuromodulation of local and remote effects of nematode infection in small intestine versus coloa

Neuromodulation of local and remote effects of nematode infection in small intestine versus coloa

Neuromodulation of local and remote effects of nematode infection in small intestine versus coloa

Neuromodulation of local and remote effects of nematode infection in small intestine versus coloa

The distribution of pepsinogen within the abomasa of cattle and sheep infected with Ostertagia spp. and sheep infected with Haemonchus contortus

The effect of nematode infections on the production of pepsinogen by ruminants was investigated immunohistochemically and biochemically. Abomasal tissues were collected from parasite-naive cattle and sheep, from sheep infected with predominantly Ostertagia circumcincta, sheep infected experimentally with Haemonchus contortus and cattle infected with Ostertagia ostertagi. Pepsinogen was also assayed biochemically in homogenates of fundic mucosae from sheep infected with predominantly O. circumcincta. Infection with Ostertagia spp. parasites was associated mainly with nodular hyperplasia, resulting in increased numbers of cells that produce both pepsinogen and mucus. Measured biochemically, nodules contained more pepsinogen than adjacent more normal mucosa ( p < 0.05), and this effect was largely attributable to the greater mass of nodules. Infection of sheep with H. contortus was associated with generalised hyperplasia, characterised by increased numbers of mucopeptic cells and in at least one animal with reductions in parietal cell numbers. At the same time, the zymogen granule content of chief cells was reduced. Similar changes were occasionally seen in sheep infected predominantly with O. circumcincta. Generalised hyperplasia is likely to be indicative of the presence of ambulatory parasitic stages as opposed to those confined to nodules. The potential for the enhanced production of pepsinogen by increased numbers of cells with a joint mucous cell and zymogenic cell phenotype may offset decreases in the numbers of chief cells or reductions in chief cell activity.

The effect of nematode infection upon intestinal smooth muscle function.

Nematode infections are useful in studying both host defence and inflammation induced changes in intestinal physiology, including increased contraction by intestinal muscle. Our initial studies of the heightened muscle function found during T. spiralis infection led to investigations of the role of immune and inflammatory cells and mediators in the immunodulation of intestinal muscle function. By infecting various immunodeficient mouse strains, as well as gene transfer to the intestine, T lymphocytes, and in particular the CD4+ve subset were found to be responsible for altering smooth muscle function. However, eosinophils as well as the cytokine interleukin-4 may also be involved. Investigations also indicate a potential role for increased muscle function and propulsive activity in expelling nematode parasites. Mutant mice which suffer aberrant intestinal propulsion, or based upon an immunodeficiency, undergo reduced changes in muscle function during infection, undergo prolonged infections. While increased muscle function may be an adaptive host response, the changes in muscle function may persist long after the resolution of the infection. Thus understanding the mechanisms behind the immunomodulation of intestinal muscle function may also impact upon clinical gastroenterology, since motility disturbances in man often occur following enteric infections, or other inflammatory conditions of the bowel.

Effects of the root-knot nematode, Meloidogyne incognita, on the sensitivity of tomato to sulfur dioxide and ozone

Infection of plants with root-knot nematode leads to an increase in transpiration rate. We hypothesize that, in infected plants, the diffusive intake of gaseous pollutants would be greater and the interaction between the nematode and pollutant(s) would be governed by the degree of stomatal opening. Tomato plants infected with the root-knot nematode, Meloidogyne incognita were exposed to air containing 0, 50 or 100 ppb of SO 2 or O 3 for 5 h every third day on 27 occasions in 1988 and 1989. Plants exposed to the gases at 100 ppb had chlorotic and/or necrotic leaves, small shoots and roots, reduced leaf pigment levels and low yield, compared to untreated plants. Greater foliar injury developed on plants exposed to SO 2 + O 3 mixture. Symptoms were even greater on nematode-infected exposed plants. M. incognita alone reduced tomato yield by 14.4% and induced a 3.6% increase in the width of stomatal pores and a 15.6% increase in the transpiration rate. A positive correlation was observed between stomatal pore width and rate of transpiration. Interaction between SO 2 and O 3 depended on the presence (significant) or absence (insignificant) of nematodes. Most effects of nematode infection and gas exposures (especially mixtures) were synergistic. Disease intensity (galls per root system) was increased, but nematode reproduction (egg masses per root system, eggs per egg mass) reduced on plants exposed to SO 2 and/or O 3.

Effects of nematode infection on sensitivity to intestinal distension: Role of tachykinin NK 2 receptors

Distension of the rat intestine causes a depressor response which is predictive of nociception. This study investigated the effects of previous infection with Nippostrongylus (N.) brasiliensis on the sensitivity to intestinal distension and the role of tachykinin NK 2 receptors. The tachykinin NK 2 receptor antagonist, SR48968 ( S)- N-methyl- N[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)butyl]benzamide) inhibited the nociceptive response (ED 50=0.7 mg/kg) in control rats. In post- N. brasiliensis-infected rats sensitivity to intestinal distension was increased which was accompanied by an increase in the apparent potency value of SR48968 (ED 50=0.1 mg/kg). The hypersensitivity was limited to areas of hypermastocytosis. It is concluded that the post-inflammatory changes that occur in post-infected rats increase visceral sensitivity and the apparent potency of tachykinin NK 2 receptor antagonists.

Epidemiology and effects of nematode infections on beef cow-calf systems of Argentina's western pampas

The epidemiology and the effects of nematode infections on cow-calf systems were followed from 3 weeks before calving to 7 months afterwards. Two groups, each of 15 cow-calf pairs grazed on separate lucerne pastures. Group I (GI) were treated monthly with oxfendazole (4.5 mg kg −1), cows being dosed from calving and calves starting 45 days later. Animals in Group II (GII) were not treated. The egg output of the cows was very low. An increase was recorded 2 months after parturition, consisting mainly of Ostertagia spp. The egg output and worm burdens of calves remained low until late summer and reached a peak in autumn. Ostertagia, Cooperia and Haemonchus were the main genera recovered from slaughtered calves. The pasture contamination and tracer calf worm counts remained consistently low until autumn when they began to increase. Inhibited early fourth stage larvae of Ostertagia were recovered during spring. After calving, the live-weight gains (LWG) of treated GI cows were significantly higher ( P < 0.004) than those of GII cows, whereas the LWG of GI calves were significantly higher during December ( P < 0.037) and March ( P < 0.029) than those of GII calves. There were significant ( P < 0.04) cumulative LWG responses between GI and GII calves with no differences in cow cumulative LWG at the end of the trial. For spring-born calves, these results suggest that strategic deworming programs in cow-calf systems may produce benefits.

Effect of anthelmintic treatment of second-year cattle on growth performance during winter housing and first lactation yield

The effect of nematode infections on growth performance during winter housing and on first lactation yield was investigated in heifers on 69 farms. Half of each herd was treated with albendazole after housing, which resulted in significantly reduced egg output, antibody titres against Ostertagia and Cooperia, and pepsinogen values compared with the untreated control groups. Albendazole-treated groups gained on average 0.007 cm day −1 heart girth (i.e. 0.05 kg day −1) more than control groups during the housing period ( P⩽0.10), varying from −0.060 to +0.137 cm day −1 among herds. Albendazole-treated heifers produced 195.4 kg milk per 305-day lactation more than untreated heifers ( P<0.01). Per herd, the mean milk yield response to treatment was +313.8 kg milk ( P<0.01), varying from −876 to +1950 kg. Milk production of untreated heifers increased by 10.5 kg milk kg −1 extra body weight, adjusted for age, measured after the second grazing season ( P < 0.05). This suggests that nematode infections occurring in the first 2 years of life negatively influence milk production by reducing weight gains and hence body weight at calving.

Effect of nematode infections on growth performance of calves after stabling on commercial dairy farms

Growth performance of calves was assessed on 32 farms during winter housing. Nematode infection was measured by antibody titres, pepsinogen values, and faecal examinations. Half of each herd was treated with ivermectin after stabling. Treatment significantly increased growth rate by an average of +0.059 kg day −1 ( P < 0.01). The effect of treatment varied among herds from −0.078 to +0.210 kg day −1. Only a few of the infection parameters correlated weakly, but positively, to the effect of treatment on growth performance per herd. Untreated control groups showed very different growth rates among herds, ranging from 0.250 to 0.936 kg day −1. This was strongly correlated to several infection parameters. Groups with the highest values for the infection parameters gained approximately 50 kg less over a 4-month period during winter housing than groups with the lowest values for those infection parameters.

Effect of nematode infections on growth performance of calves during winter housing on dairy farms

Growth performance of calves was estimated by means of heart girth measurements on 48 farms during winter housing (from December to the end of March). Level of exposure to nematode infection was measured by antibody titres, pepsinogen values, and faecal examinations. Half of each herd was treated with albendazole after housing. All infection parameters measured in March were significantly lower in the treated groups than in the untreated control groups. Treatment increased growth rate by an average of + 0.007 cm day −1 (N.S.), i.e. + 0.036 kg day −1. Effect of treatment varied from −0.075 to + 0.100 cm day −1 among herds. This effect of treatment on the growth performance was significantly correlated positively to pepsinogen value ( r=0.321, P<0.05 measured in October; r=0.265, P<0.10 measured in December). Control groups showed very different growth rates among herds, ranging from 0.023 to 0.170 cm day −1, i.e. 0.112–0.874 kg day −1. This variation was strongly related to several infection parameters, particularly those measured in October. The most pronounced correlation was found between the average daily gain of the control groups and the mean heard antibody titre against Ostertagia spp. measured in October ( r=−0.413, P<0.01). These results were consistent with those of a similar study conducted on commercial dairy farms a year earlier.