Profiling extracellular vesicle release by the filarial nematode Brugia malayi reveals sex-specific differences in cargo and a sensitivity to ivermectin

PubMed Central

Harischandra, Hiruni; Yuan, Wang; Zamanian, Mostafa

2018-01-01

The filarial nematode Brugia malayi is an etiological agent of Lymphatic Filariasis. The capability of B. malayi and other parasitic nematodes to modulate host biology is recognized but the mechanisms by which such manipulation occurs are obscure. An emerging paradigm is the release of parasite-derived extracellular vesicles (EV) containing bioactive proteins and small RNA species that allow secretion of parasite effector molecules and their potential trafficking to host tissues. We have previously described EV release from the infectious L3 stage B. malayi and here we profile vesicle release across all intra-mammalian life cycle stages (microfilariae, L3, L4, adult male and female worms). Nanoparticle Tracking Analysis was used to quantify and size EVs revealing discrete vesicle populations and indicating a secretory process that is conserved across the life cycle. Brugia EVs are internalized by murine macrophages with no preference for life stage suggesting a uniform mechanism for effector molecule trafficking. Further, the use of chemical uptake inhibitors suggests all life stage EVs are internalized by phagocytosis. Proteomic profiling of adult male and female EVs using nano-scale LC-MS/MS described quantitative and qualitative differences in the adult EV proteome, helping define the biogenesis of Brugia EVs and revealing sexual dimorphic characteristics in immunomodulatory cargo. Finally, ivermectin was found to rapidly inhibit EV release by all Brugia life stages. Further this drug effect was also observed in the related filarial nematode, the canine heartworm Dirofilaria immitis but not in an ivermectin-unresponsive field isolate of that parasite, highlighting a potential mechanism of action for this drug and suggesting new screening platforms for anti-filarial drug development. PMID:29659599

Humoral and cell-mediated immune responses elicited by poly (DL-lactide) adjuvanted filarial antigen molecules.

PubMed

Saini, Vinay; Verma, Atul Kumar; Kushwaha, Vikas; Joseph, Sujith Kurian; Murthy, P Kalpna; Kohli, Dharmveer

2014-05-01

In our recent studies, Brugia malayi molecules have shown interesting immune-stimulating and immune-suppressive properties. Among these, F6 a pro-inflammatory (54-68 kDa) SDS-PAGE resolved fraction of the parasite when administered with Freund's complete/incomplete adjuvant in animals, elicited both Th1 and Th2 type immune responses and protects the host from filarial parasite. The present study was aimed at developing biodegradable microspheres for filarial antigenic protein molecules and to investigate the immunoadjuvanticity of microspheres (Ms)-loaded F6 molecules. Poly-lactide microspheres (DL-PLA-Ms) were prepared using double emulsification and solvent evaporation method; and studied their size, shape, antigen adsorption efficiency, in-process stability, and antigen release profiles. F6 and B. malayi adult worm (BmA: ∼ 17 to 180 kDa) protein molecules adsorbed on the Ms were administered in a single shot into Swiss mice, subcutaneously, and investigated their immunoadjuvant effect and compared with one/two doses-schedule of plain F6/BmA. Immunization with F6/BmA-loaded DL-PLA-Ms resulted in upregulation of cellular proliferation, IFN- γ, TNF-α and NO release from host's cells stimulated with F6/BmA or LPS/Con A, IgG, IgG1 and IgG2a levels. These responses were well comparable with the responses produced by two doses of plain BmA/F6. In conclusion, a single dose of DL-PLA-Ms-F6 induced predominantly Th1 immune responses and well comparable with two doses of plain F6. This is the first ever report on potential of DL-PLA-Ms as adjuvant for filarial immunogen.

A Proteomic Analysis of the Body Wall, Digestive Tract, and Reproductive Tract of Brugia malayi

PubMed Central

Morris, C. Paul; Bennuru, Sasisekhar; Kropp, Laura E.; Zweben, Jesse A.; Meng, Zhaojing; Taylor, Rebekah T.; Chan, King; Veenstra, Timothy D.; Nutman, Thomas B.; Mitre, Edward

2015-01-01

Filarial worms are parasitic nematodes that cause devastating diseases such as lymphatic filariasis (LF) and onchocerciasis. Filariae are nematodes with complex anatomy including fully developed digestive tracts and reproductive organs. To better understand the basic biology of filarial parasites and to provide insights into drug targets and vaccine design, we conducted a proteomic analysis of different anatomic fractions of Brugia malayi, a causative agent of LF. Approximately 500 adult female B. malayi worms were dissected, and three anatomical fractions (body wall, digestive tract, and reproductive tract) were obtained. Proteins from each anatomical fraction were extracted, desalted, trypsinized, and analyzed by microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry. In total, we identified 4,785 B. malayi proteins. While 1,894 were identified in all three anatomic fractions, 396 were positively identified only within the digestive tract, 114 only within the body wall, and 1,011 only within the reproductive tract. Gene set enrichment analysis revealed a bias for transporters to be present within the digestive tract, suggesting that the intestine of adult filariae is functional and important for nutrient uptake or waste removal. As expected, the body wall exhibited increased frequencies of cytoskeletal proteins, and the reproductive tract had increased frequencies of proteins involved in nuclear regulation and transcription. In assessing for possible vaccine candidates, we focused on proteins sequestered within the digestive tract, as these could possibly represent “hidden antigens” with low risk of prior allergic sensitization. We identified 106 proteins that are enriched in the digestive tract and are predicted to localize to the surface of cells in the the digestive tract. It is possible that some of these proteins are on the luminal surface and may be accessible by antibodies ingested by the worm. A subset of 27 of these proteins appear especially promising vaccine candidates as they contain significant non-cytoplasmic domains, only 1–2 transmembrane domains, and a high degree of homology to W. bancrofti and/or O. volvulus. PMID:26367142

Efficacy of Three-Week Oxytetracycline or Rifampin Monotherapy Compared with a Combination Regimen against the Filarial Nematode Onchocerca ochengi

PubMed Central

Bah, Germanus S.; Ward, Emma L.; Srivastava, Abhishek; Trees, Alexander J.; Tanya, Vincent N.

2014-01-01

Onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, is a major cause of visual impairment and dermatitis in sub-Saharan Africa. As O. volvulus contains an obligatory bacterial symbiont (Wolbachia), it is susceptible to antibiotic chemotherapy, although current regimens are considered too prolonged for community-level control programs. The aim of this study was to compare the efficacies of oxytetracycline and rifampin, administered separately or in combination, against a close relative of O. volvulus (Onchocerca ochengi) in cattle. Six animals per group were treated with continuous or intermittent oxytetracycline regimens, and effects on adult worm viability, dermal microfilarial loads, and Wolbachia density in worm tissues were assessed. Subsequently, the efficacies of 3-week regimens of oxytetracycline and rifampin alone and a combination regimen were compared, and rifampin levels in plasma and skin were quantified. A 6-month regimen of oxytetracycline with monthly dosing was strongly adulticidal, while 3-week and 6-week regimens exhibited weaker adulticidal effects. However, all three regimens achieved >2-log reductions in microfilarial load. In contrast, rifampin monotherapy and oxytetracycline-rifampin duotherapy failed to induce substantive reductions in either adult worm burden or microfilarial load, although a borderline effect on Wolbachia density was observed following duotherapy. Dermal rifampin levels were maintained above the MIC for >24 h after a single intravenous dose. We conclude that oxytetracycline-rifampin duotherapy is less efficacious against O. ochengi than oxytetracycline alone. Further studies will be required to determine whether rifampin reduces oxytetracycline bioavailability in this system, as suggested by human studies using other tetracycline-rifampin combinations. PMID:24247133

Efficacy of three-week oxytetracycline or rifampin monotherapy compared with a combination regimen against the filarial nematode Onchocerca ochengi.

PubMed

Bah, Germanus S; Ward, Emma L; Srivastava, Abhishek; Trees, Alexander J; Tanya, Vincent N; Makepeace, Benjamin L

2014-01-01

Onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, is a major cause of visual impairment and dermatitis in sub-Saharan Africa. As O. volvulus contains an obligatory bacterial symbiont (Wolbachia), it is susceptible to antibiotic chemotherapy, although current regimens are considered too prolonged for community-level control programs. The aim of this study was to compare the efficacies of oxytetracycline and rifampin, administered separately or in combination, against a close relative of O. volvulus (Onchocerca ochengi) in cattle. Six animals per group were treated with continuous or intermittent oxytetracycline regimens, and effects on adult worm viability, dermal microfilarial loads, and Wolbachia density in worm tissues were assessed. Subsequently, the efficacies of 3-week regimens of oxytetracycline and rifampin alone and a combination regimen were compared, and rifampin levels in plasma and skin were quantified. A 6-month regimen of oxytetracycline with monthly dosing was strongly adulticidal, while 3-week and 6-week regimens exhibited weaker adulticidal effects. However, all three regimens achieved >2-log reductions in microfilarial load. In contrast, rifampin monotherapy and oxytetracycline-rifampin duotherapy failed to induce substantive reductions in either adult worm burden or microfilarial load, although a borderline effect on Wolbachia density was observed following duotherapy. Dermal rifampin levels were maintained above the MIC for >24 h after a single intravenous dose. We conclude that oxytetracycline-rifampin duotherapy is less efficacious against O. ochengi than oxytetracycline alone. Further studies will be required to determine whether rifampin reduces oxytetracycline bioavailability in this system, as suggested by human studies using other tetracycline-rifampin combinations.

Detection and molecular characterization of the mosquito-borne filarial nematode Setaria tundra in Danish roe deer (Capreolus capreolus).

PubMed

Enemark, Heidi Larsen; Oksanen, Antti; Chriél, Mariann; le Fèvre Harslund, Jakob; Woolsey, Ian David; Al-Sabi, Mohammad Nafi Solaiman

2017-04-01

Setaria tundra is a mosquito-borne filarial nematode of cervids in Europe. It has recently been associated with an emerging epidemic disease causing severe morbidity and mortality in reindeer and moose in Finland. Here, we present the first report of S. tundra in six roe deer ( Capreolus capreolus ) collected between October 2010 and March 2014 in Denmark. The deer originated from various localities across the country: the eastern part of the Jutland peninsular and four locations on the island Zealand. With the exception of one deer, with parasites residing in a transparent cyst just under the liver capsule, worms (ranging from 2 to >20/deer) were found free in the peritoneal cavity. The worms were identified as S. tundra by morphological examination and/or molecular typing of the mitochondrial 12S rRNA and cox1 genes, which showed 99.1-99.8% identity to previously published S. tundra isolates from Europe. Roe deer are generally considered as asymptomatic carriers and their numbers in Denmark have increased significantly in recent decades. In light of climatic changes which result in warmer, more humid weather in Scandinavia greater numbers of mosquitoes and, especially, improved conditions for development of parasite larvae in the mosquito vectors are expected, which may lead to increasing prevalence of S. tundra . Monitoring of this vector-borne parasite may thus be needed in order to enhance the knowledge of factors promoting its expansion and prevalence as well as predicting disease outbreaks.

[Update on cutaneous dirofilariasis].

PubMed

Benzaquen, M; Marmottant, E; Parola, P; Berbis, P

2017-10-01

Dirofilariasis is a worldwide zoonotic infection that rarely affects humans and is caused by filarial nematodes of the genus Diroflaria transmitted by mosquitoes. Cutaneous dirofilariasis, due to D. repens, presents as inflammatory lesions that develop into subcutaneous nodules. These clinical symptoms may be consistent with Wells' cellulitis. Diagnosis of dirofilariasis involves demonstration of the presence of the nematode during skin biopsy and identification of the worm through macroscopic, histological and PCR analysis. Surgical resection of the nodule remains the gold standard treatment. The number of cases of human cutaneous dirofilariasis has increased in the recent years and the disease must not be misdiagnosed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Elephantiasis of non-filarial origin (podoconiosis) in the highlands of north-western Cameroon.

PubMed

Wanji, S; Tendongfor, N; Esum, M; Che, J N; Mand, S; Tanga Mbi, C; Enyong, P; Hoerauf, A

2008-09-01

Lymphoedema, a condition of localized fluid retention, results from a compromised lymphatic system. Although one common cause in the tropics is infection with filarial worms, non-filarial lymphoedema, also known as podoconiosis, has been reported among barefoot farmers in volcanic highland zones of Africa, Central and South America and north-western India. There are conflicting reports on the causes of lymphoedema in the highland regions of Cameroon, where the condition is of great public-health importance. To characterise the focus of lymphoedema in the highlands of the North West province of Cameroon and investigate its real causes, a cross-sectional study was carried out on the adults (aged > or =15 years) living in the communities that fall within the Ndop and Tubah health districts. The subjects, who had to have lived in the study area for at least 10 years, were interviewed, examined clinically, and, when possible, checked for microfilaraemia. The cases of lymphoedema confirmed by ultrasonography and a random sample of the other subjects were also tested for filarial antigenaemia. The interviews, which explored knowledge, attitudes and perceptions (KAP) relating to lymphoedema, revealed that the condition was well known, with each study community having a local name for it. Of the 834 individuals examined clinically, 66 (8.1%) had lymphoedema of the lower limb, with all the clinical stages of this condition represented. None of the 792 individuals examined parasitologically, however, had microfilariae of W. bancrofti (or any other filarial parasite) in their peripheral blood, and only one (0.25%) of the 399 individuals tested for the circulating antigens of W. bancrofti gave a positive result. In addition, none of the 504 mosquitoes caught landing on human bait in the study area and dissected was found to harbour any stage of W. bancrofti. These findings indicate that the elephantiasis seen in the North West province of Cameroon is of non-filarial origin.

Heme acquisition in the parasitic filarial nematode Brugia malayi.

PubMed

Luck, Ashley N; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E; Hamza, Iqbal; Foster, Jeremy M

2016-10-01

Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non-heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3-6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.-Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. © The Author(s).

Heme acquisition in the parasitic filarial nematode Brugia malayi

PubMed Central

Luck, Ashley N.; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E.; Hamza, Iqbal; Foster, Jeremy M.

2016-01-01

Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi. In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non–heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3–6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.—Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. PMID:27363426

Oral dirofilariasis.

PubMed

Janardhanan, Mahija; Rakesh, S; Savithri, Vindhya

2014-01-01

Filariasis affecting animals can rarely cause infections in human beings through the accidental bite of potential vectors. The resulting infection in man, known as zoonotic filariasis occur worldwide. Human dirofilariasis, the most common zoonotic filariasis, is caused by the filarial worm belonging to the genus Dirofilaria. Dirofilarial worms, which are recognized as pathogenic in man can cause nodular lesions in the lung, subcutaneous tissue, peritoneal cavity or eyes. Oral dirofilariasis is extremely rare and only a few cases have been documented. We report an interesting case of dirofilariasis due to Dirofilaria repens involving buccal mucosa in a patient who presented with a facial swelling. The clinical features, diagnostic issues and treatment aspects are discussed. This paper stresses the importance of considering dirofilariasis as differential diagnosis for subcutaneous swelling of the face, especially in areas where it is endemic.

Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung

PubMed Central

Pionnier, Nicolas; Vallarino-Lhermitte, Nathaly; Lefoulon, Emilie; Nieguitsila, Adélaïde; Specht, Sabine; Carlin, Leo M.; Martin, Coralie

2017-01-01

Filarial infections are tropical diseases caused by nematodes of the Onchocercidae family such as Mansonella perstans. The infective larvae (L3) are transmitted into the skin of vertebrate hosts by blood-feeding vectors. Many filarial species settle in the serous cavities including M. perstans in humans and L. sigmodontis, a well-established model of filariasis in mice. L. sigmodontis L3 migrate to the pleural cavity where they moult into L4 around day 9 and into male and female adult worms around day 30. Little is known of the early phase of the parasite life cycle, after the L3 is inoculated in the dermis by the vector and enters the afferent lymphatic vessels and before the moulting processes in the pleural cavity. Here we reveal a pulmonary phase associated with lung damage characterized by haemorrhages and granulomas suggesting L3 reach the lung via pulmonary capillaries and damage the endothelium and parenchyma by crossing them to enter the pleural cavity. This study also provides evidence for a transient inflammation in the lung characterized by a very early recruitment of neutrophils associated with high expression levels of S100A8 and S100A9 proteins. PMID:28486498

The nurse of parasites: gender concepts in Patrick Manson's parasitological research.

PubMed

Li, Shang-Jen

2004-01-01

Patrick Manson (1844-1922), the so-called father of tropical medicine, played a pivotal role in making that discipline into a specialty. During his early career in China he discovered that the mosquito was the intermediate host of the filarial parasite and he somewhat peculiarly called the mosquito the "nurse" of the filarial worm. The discovery contributed greatly to the intellectual foundation of modern parasitology. In this paper I situate Manson's nomenclature in the context of nineteenth-century biological research on reproductive mech-anisms and argue that Manson's concept of the "nurse" was derived from nineteenth-century theories of sexual division of labor in nature's economy. The way he framed the relation between the mosquito and the parasite, moreover, can be understood in the terms of the domestic arrangement of the colonial European household. Manson's research demonstrates the significant exchange between medical concerns over European women's procreative role in the tropics and biological studies of parasitic reproduction.

Mansonella ozzardi and its vectors in the New World: an update with emphasis on the current situation in Haiti.

PubMed

Raccurt, C P

2017-10-25

Mansonella ozzardi (Nematoda: Onchocercidae) is a little studied filarial nematode. This human parasite, transmitted by two families of dipteran vectors, biting midges (most of them members of the genus Culicoides) and blackflies (genus Simulium), is endemic to the Neotropical regions of the New World. With a patchy geographical distribution from southern Mexico to north-western Argentina, human infection with M. ozzardi is highly prevalent in some of the Caribbean islands, along riverine communities in the Amazon Basin, and on both sides of the border between Bolivia and Argentina. Studies conducted in Haiti between 1974 and 1984 allowed the first complete description of the adult worm and permitted clarification of the taxonomic position of this filarial species. This paper reports the known geographical distribution of M. ozzardi in Neotropical regions of the Americas, and focuses on the current situation in Haiti where this filariasis remains a completely neglected public health problem.

A Comprehensive, Model-Based Review of Vaccine and Repeat Infection Trials for Filariasis

PubMed Central

Morris, C. Paul; Evans, Holly; Larsen, Sasha E.

2013-01-01

SUMMARY Filarial worms cause highly morbid diseases such as elephantiasis and river blindness. Since the 1940s, researchers have conducted vaccine trials in 27 different animal models of filariasis. Although no vaccine trial in a permissive model of filariasis has provided sterilizing immunity, great strides have been made toward developing vaccines that could block transmission, decrease pathological sequelae, or decrease susceptibility to infection. In this review, we have organized, to the best of our ability, all published filaria vaccine trials and reviewed them in the context of the animal models used. Additionally, we provide information on the life cycle, disease phenotype, concomitant immunity, and natural immunity during primary and secondary infections for 24 different filaria models. PMID:23824365

Immunotherapy with mutated onchocystatin fails to enhance the efficacy of a sub-lethal oxytetracycline regimen against Onchocerca ochengi.

PubMed

Bah, Germanus S; Tanya, Vincent N; Makepeace, Benjamin L

2015-08-15

Human onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, has been successfully controlled by a single drug, ivermectin, for over 25 years. Ivermectin prevents the disease symptoms of severe itching and visual impairment by killing the microfilarial stage, but does not eliminate the adult parasites, necessitating repeated annual treatments. Mass drug administration with ivermectin does not always break transmission in forest zones and is contraindicated in individuals heavily co-infected with Loa loa, while reports of reduced drug efficacy in Ghana and Cameroon may signal the development of resistance. An alternative treatment for onchocerciasis involves targeting the essential Wolbachia symbiont with tetracycline or its derivatives, which are adulticidal. However, implementation of antibiotic therapy has not occurred on a wide scale due to the prolonged treatment regimen required (several weeks). In the bovine Onchocerca ochengi system, it has been shown previously that prolonged oxytetracycline therapy increases eosinophil counts in intradermal nodules, which kill the adult worms by degranulating on their surface. Here, in an "immunochemotherapeutic" approach, we sought to enhance the efficacy of a short, sub-lethal antibiotic regimen against O. ochengi by prior immunotherapy targeting onchocystatin, an immunomodulatory protein located in the adult female worm cuticle. A key asparagine residue in onchocystatin was mutated to ablate immunomodulatory activity, which has been demonstrated previously to markedly improve the protective efficacy of this vaccine candidate when used as an immunoprophylactic. The immunochemotherapeutic regimen was compared with sub-lethal oxytetracycline therapy alone; onchocystatin immunotherapy alone; a gold-standard prolonged, intermittent oxytetracycline regimen; and no treatment (negative control) in naturally infected Cameroonian cattle. Readouts were collected over one year and comprised adult worm viability, dermal microfilarial density, anti-onchocystatin IgG in sera, and eosinophil counts in nodules. Only the gold-standard antibiotic regimen achieved significant killing of adult worms, a profound reduction in microfilarial load, and a sustained increase in local tissue eosinophilia. A small but statistically significant elevation in anti-onchocystatin IgG was observed for several weeks after immunisation in the immunotherapy-only group, but the antibody response in the immunochemotherapy group was more variable. At 12 weeks post-treatment, only a transient and non-significant increase in eosinophil counts was apparent in the immunochemotherapy group. We conclude that the addition of onchocystatin immunotherapy to a sub-lethal antibiotic regimen is insufficient to induce adulticidal activity, although with booster immunisations or the targeting of additional filarial immunomodulatory proteins, the efficacy of this strategy could be strengthened. Copyright © 2015 Elsevier B.V. All rights reserved.

Macrofilaricidal and microfilaricidal effects of Neurolaena lobata, a Guatemalan medicinal plant, on Brugia pahangi.

PubMed

Fujimaki, Y; Kamachi, T; Yanagi, T; Cáceres, A; Maki, J; Aoki, Y

2005-03-01

Twelve extracts of 11 Guatemalan medicinal plants were initially screened in vitro for potential macrofilaricidal activity against Brugia pahangi, a lymphatic dwelling filarial worm, using concentrations from 125 to 1000 microg ml(-1) of each extract that could be dissolved in the culture medium. Of 12 extracts used, the ethanol extract of leaves of Neurolaena lobata showed the strongest activity against the motility of adult worms. Subsequently, the extract of N. lobata was extensively examined in vitro for macro- and micro-filaricidal effects using a series of concentrations of 500, 250, 100, 50 and 10 microg ml(-1). The effects were assessed by worm motility, microfilarial release by female worms and a MTT assay. The effect on the motility of adult worms was observed in a concentration- and time-dependent manner. The time required to stop motility of both sexes of adult worms was 6 h at 500 microg ml(-1), 24 h at 250 microg ml(-1), and 3 days for females and 4 days for males at 100 microg ml(-1). The movement of females ceased at 4 days at a concentration of 50 microg ml(-1) whereas the motility of males was only reduced. The loss of worm's viability was confirmed by the MTT assay and was similar to the motility results. These concentrations, including 10 microg ml(-1), prevented microfilarial release by females in a concentration- and time-dependent manner. Concentrations higher than 100 microg ml(-1) even induced mortality of the microfilariae. The present study suggested that the ethanol extract of Neurolaena lobata has potential macro- and micro-filaricidal activities.

Diminished IL-17A levels may protect filarial-infected individuals from development of rheumatoid arthritis and systemic lupus erythematosus.

PubMed

Panda, A K; Das, B K

2017-04-01

Nematode infections have been observed to inversely correlate with autoimmune disorders. Recently, we have shown the absence of filarial infection in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who live in filarial-endemic areas. The mechanism(s) by which filarial-infected individuals are protected against the development of RA or SLE are unknown. In mice CIA, an experimental model for RA, ES-62, an execratory product of rodent filarial nematode , has been shown to improve arthritis through suppression of the IL-17 pathway. A total of 160 individuals, 40 each of endemic normal, filarial-infected cases, SLE and RA patients, from filarial-endemic areas, were enrolled in the study. Plasma levels of IL17-A, IFN-α and TNF-α were quantified by enzyme-linked immunosorbent assay (ELISA). RA and SLE patients displayed significantly higher plasma IL-17A, IFN-α and TNF-α levels compared to endemic normal and infected individuals. Furthermore, IL-17A levels were significantly low in participants with filarial infection compared to endemic controls ( p < 0.05). Interestingly, plasma IL-17A levels correlated inversely with circulating filarial antigen (CFA) ( p = 0.004, Spearman r = -0.51). Filarial infection was associated with low plasma IL-17A levels, a mechanism by which it possibly protects individuals in filarial-endemic areas from the development of autoimmune disorders like RA and SLE.

Efficacy and tolerability of treatment with single doses of diethylcarbamazine (DEC) and DEC plus albendazole (ABZ) for three consecutive years in lymphatic filariasis: a field study in India.

PubMed

Kshirsagar, Nilima A; Gogtay, N J; Garg, B S; Deshmukh, P R; Rajgor, D D; Kadam, V S; Thakur, P A; Gupta, A; Ingole, N S; Lazdins-Helds, J K

2017-10-01

Lymphatic filariasis (LF) affects 73 countries, causes morbidity and impedes socioeconomic development. We had found no difference in safety and micro (Mf) and macro filarial action of single-dose diethylcarbamazine (DEC) and DEC + albendazole (ABZ) in an F01 study done in India (year 2000). There was a programmatic need to evaluate safety and efficacy of multiple annual treatments (F02). Subjects (155) from the F01 study, meeting inclusion-exclusion criteria, were enrolled in F02 and treated with further two annual doses of DEC or DEC + ABZ. Efficacy was evaluated for Mf positivity by peripheral smear (PS) and nucleopore (NP) filter, circulating filarial antigen (CFA) and filarial dance sign (FDS) positivity and Mf count at yearly follow-up. Safety was assessed for 5 days after drug administration. Total of 139 subjects evaluated for efficacy (69 DEC and 70 DEC + ABZ group). Mf positivity prevalence declined progressively by 95% (PS), 66% (NP), and 95% (PS) and 86% (NP); CFA positivity prevalence declined by 15% and 9%; FDS by 100% each; Mf count declined by 75.5 and 76.9% with three annual treatment of DEC and DEC + ABZ, respectively. Addition of ABZ did not show any advantage over DEC given as three annual rounds for LF. DEC and DEC + ABZ were well tolerated. There was no correlation between result of CFA and FDS, (both claimed to be indicative of adult worm). Analysis of published studies and our data indicate that macrofilaricidal effect of DEC/DEC + ABZ may be seen in children and not adults, with three or more annual dosing.

Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection.

PubMed

Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J; Zhan, Bin; Lustigman, Sara; Klei, Thomas R

2016-04-01

The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted.

Vaccination of Gerbils with Bm-103 and Bm-RAL-2 Concurrently or as a Fusion Protein Confers Consistent and Improved Protection against Brugia malayi Infection

PubMed Central

Arumugam, Sridhar; Wei, Junfei; Liu, Zhuyun; Abraham, David; Bell, Aaron; Bottazzi, Maria Elena; Hotez, Peter J.; Zhan, Bin; Lustigman, Sara; Klei, Thomas R.

2016-01-01

Background The Brugia malayi Bm-103 and Bm-RAL-2 proteins are orthologous to Onchocerca volvulus Ov-103 and Ov-RAL-2, and which were selected as the best candidates for the development of an O. volvulus vaccine. The B. malayi gerbil model was used to confirm the efficacy of these Ov vaccine candidates on adult worms and to determine whether their combination is more efficacious. Methodology and Principle Findings Vaccine efficacy of recombinant Bm-103 and Bm-RAL-2 administered individually, concurrently or as a fusion protein were tested in gerbils using alum as adjuvant. Vaccination with Bm-103 resulted in worm reductions of 39%, 34% and 22% on 42, 120 and 150 days post infection (dpi), respectively, and vaccination with Bm-RAL-2 resulted in worm reductions of 42%, 22% and 46% on 42, 120 and 150 dpi, respectively. Vaccination with a fusion protein comprised of Bm-103 and Bm-RAL-2 resulted in improved efficacy with significant reduction of worm burden of 51% and 49% at 90 dpi, as did the concurrent vaccination with Bm-103 and Bm-RAL-2, with worm reduction of 61% and 56% at 90 dpi. Vaccination with Bm-103 and Bm-RAL-2 as a fusion protein or concurrently not only induced a significant worm reduction of 61% and 42%, respectively, at 150 dpi, but also significantly reduced the fecundity of female worms as determined by embryograms. Elevated levels of antigen-specific IgG were observed in all vaccinated gerbils. Serum from gerbils vaccinated with Bm-103 and Bm-RAL-2 individually, concurrently or as a fusion protein killed third stage larvae in vitro when combined with peritoneal exudate cells. Conclusion Although vaccination with Bm-103 and Bm-RAL-2 individually conferred protection against B. malayi infection in gerbils, a more consistent and enhanced protection was induced by vaccination with Bm-103 and Bm-RAL-2 fusion protein and when they were used concurrently. Further characterization and optimization of these filarial vaccines are warranted. PMID:27045170

Recent Advances on the Use of Biochemical Extracts as Filaricidal Agents

PubMed Central

Al-Abd, Nazeh M.; Nor, Zurainee Mohamed; Al-Adhroey, Abdulelah H.; Suhaimi, Anwar; Sivanandam, S.

2013-01-01

Lymphatic filariasis is a parasitic infection that causes a devastating public health and socioeconomic burden with an estimated infection of over 120 million individuals worldwide. The infection is caused by three closely related nematode parasites, namely, Wuchereria bancrofti, Brugia malayi, and B. timori, which are transmitted to human through mosquitoes of Anopheles, Culex, and Aedes genera. The species have many ecological variants and are diversified in terms of their genetic fingerprint. The rapid spread of the disease and the genetic diversification cause the lymphatic filarial parasites to respond differently to diagnostic and therapeutic interventions. This in turn prompts the current challenge encountered in its management. Furthermore, most of the chemical medications used are characterized by adverse side effects. These complications urgently warrant intense prospecting on bio-chemicals that have potent efficacy against either the filarial worms or thier vector. In lieu of this, we presented a review on recent literature that reported the efficacy of filaricidal biochemicals and those employed as vector control agents. In addition, methods used for biochemical extraction, screening procedures, and structure of the bioactive compounds were also presented. PMID:24298292

The NIH-NIAID Filariasis Research Reagent Resource Center

PubMed Central

Michalski, Michelle L.; Griffiths, Kathryn G.; Williams, Steven A.; Kaplan, Ray M.; Moorhead, Andrew R.

2011-01-01

Filarial worms cause a variety of tropical diseases in humans; however, they are difficult to study because they have complex life cycles that require arthropod intermediate hosts and mammalian definitive hosts. Research efforts in industrialized countries are further complicated by the fact that some filarial nematodes that cause disease in humans are restricted in host specificity to humans alone. This potentially makes the commitment to research difficult, expensive, and restrictive. Over 40 years ago, the United States National Institutes of Health–National Institute of Allergy and Infectious Diseases (NIH-NIAID) established a resource from which investigators could obtain various filarial parasite species and life cycle stages without having to expend the effort and funds necessary to maintain the entire life cycles in their own laboratories. This centralized resource (The Filariasis Research Reagent Resource Center, or FR3) translated into cost savings to both NIH-NIAID and to principal investigators by freeing up personnel costs on grants and allowing investigators to divert more funds to targeted research goals. Many investigators, especially those new to the field of tropical medicine, are unaware of the scope of materials and support provided by the FR3. This review is intended to provide a short history of the contract, brief descriptions of the fiilarial species and molecular resources provided, and an estimate of the impact the resource has had on the research community, and describes some new additions and potential benefits the resource center might have for the ever-changing research interests of investigators. PMID:22140585

Studies on biting midges of the genus Culicoides in the Suez Canal Zone.

PubMed

Morsy, T A; Bebars, M A; Sabry, A H; Ahmed, M M; Abdel Fattah, S A

1989-06-01

The importance of the biting midges of the genus Culicoides being in their role as vector of non periodic filarial worms of the genus Mansonella and Dipetalonema to man and pathogenic virus to livestock. Besides, their painful bite may disappear within an hour or cause an appreciable systemic reaction. In this paper, the four species recorded in the Suez Canal Zone (C. schultzei, C. puncticollis, C. pallidipennis & C. distinctipennis) were redescribed. Also, the hours of activity of the most common and abundant species, C. schultzei was studied. C. neavei Austin, 1912, representing a new record in Egypt.

Analysis of Nematode Motion Using an Improved Light-Scatter Based System

PubMed Central

Nutting, Chuck S.; Eversole, Rob R.; Blair, Kevin; Specht, Sabine; Nutman, Thomas B.; Klion, Amy D.; Wanji, Samuel; Boussinesq, Michel; Mackenzie, Charles D.

2015-01-01

Background The detailed assessment of nematode activity and viability still remains a relatively undeveloped area of biological and medical research. Computer-based approaches to assessing the motility of larger nematode stages have been developed, yet these lack the capability to detect and analyze the more subtle and important characteristics of the motion of nematodes. There is currently a need to improved methods of assessing the viability and health of parasitic worms. Methods We describe here a system that converts the motion of nematodes through a light-scattering system into an electrical waveform, and allows for reproducible, and wholly non-subjective, assessment of alterations in motion, as well as estimation of the number of nematode worms of different forms and sizes. Here we have used Brugia sp. microfilariae (L1), infective larvae (L3) and adults, together with the free-living nematode Caenorhabditis elegans. Results The motion of worms in a small (200ul) volume can be detected, with the presence of immotile worms not interfering with the readings at practical levels (up to at least 500 L1 /200ul). Alterations in the frequency of parasite movement following the application of the anti-parasitic drugs, (chloroquine and imatinib); the anti-filarial effect of the latter agent is the first demonstrated here for the first time. This system can also be used to estimate the number of parasites, and shortens the time required to estimate parasites numbers, and eliminates the need for microscopes and trained technicians to provide an estimate of microfilarial sample sizes up to 1000 parasites/ml. Alterations in the form of motion of the worms can also be depicted. Conclusions This new instrument, named a "WiggleTron", offers exciting opportunities to further study nematode biology and to aid drug discovery, as well as contributing to a rapid estimate of parasite numbers in various biological samples. PMID:25695776

Analysis of nematode motion using an improved light-scatter based system.

PubMed

Nutting, Chuck S; Eversole, Rob R; Blair, Kevin; Specht, Sabine; Nutman, Thomas B; Klion, Amy D; Wanji, Samuel; Boussinesq, Michel; Mackenzie, Charles D

2015-02-01

The detailed assessment of nematode activity and viability still remains a relatively undeveloped area of biological and medical research. Computer-based approaches to assessing the motility of larger nematode stages have been developed, yet these lack the capability to detect and analyze the more subtle and important characteristics of the motion of nematodes. There is currently a need to improved methods of assessing the viability and health of parasitic worms. We describe here a system that converts the motion of nematodes through a light-scattering system into an electrical waveform, and allows for reproducible, and wholly non-subjective, assessment of alterations in motion, as well as estimation of the number of nematode worms of different forms and sizes. Here we have used Brugia sp. microfilariae (L1), infective larvae (L3) and adults, together with the free-living nematode Caenorhabditis elegans. The motion of worms in a small (200 ul) volume can be detected, with the presence of immotile worms not interfering with the readings at practical levels (up to at least 500 L1 /200 ul). Alterations in the frequency of parasite movement following the application of the anti-parasitic drugs, (chloroquine and imatinib); the anti-filarial effect of the latter agent is the first demonstrated here for the first time. This system can also be used to estimate the number of parasites, and shortens the time required to estimate parasites numbers, and eliminates the need for microscopes and trained technicians to provide an estimate of microfilarial sample sizes up to 1000 parasites/ml. Alterations in the form of motion of the worms can also be depicted. This new instrument, named a "WiggleTron", offers exciting opportunities to further study nematode biology and to aid drug discovery, as well as contributing to a rapid estimate of parasite numbers in various biological samples.

The Population Biology and Transmission Dynamics of Loa loa.

PubMed

Whittaker, Charles; Walker, Martin; Pion, Sébastien D S; Chesnais, Cédric B; Boussinesq, Michel; Basáñez, María-Gloria

2018-04-01

Endemic to Central Africa, loiasis - or African eye worm (caused by the filarial nematode Loa loa) - affects more than 10 million people. Despite causing ocular and systemic symptoms, it has typically been considered a benign condition, only of public health relevance because it impedes mass drug administration-based interventions against onchocerciasis and lymphatic filariasis in co-endemic areas. Recent research has challenged this conception, demonstrating excess mortality associated with high levels of infection, implying that loiasis warrants attention as an intrinsic public health problem. This review summarises available information on the key parasitological, entomological, and epidemiological characteristics of the infection and argues for the mobilisation of resources to control the disease, and the development of a mathematical transmission model to guide deployment of interventions. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Obligatory symbiotic Wolbachia endobacteria are absent from Loa loa

PubMed Central

Büttner, Dietrich W; Wanji, Samuel; Bazzocchi, Chiara; Bain, Odile; Fischer, Peter

2003-01-01

Background Many filarial nematodes harbour Wolbachia endobacteria. These endobacteria are transmitted vertically from one generation to the next. In several filarial species that have been studied to date they are obligatory symbionts of their hosts. Elimination of the endobacteria by antibiotics interrupts the embryogenesis and hence the production of microfilariae. The medical implication of this being that the use of doxycycline for the treatment of human onchocerciasis and bancroftian filariasis leads to elimination of the Wolbachia and hence sterilisation of the female worms. Wolbachia play a role in the immunopathology of patients and may contribute to side effects seen after antifilarial chemotherapy. In several studies Wolbachia were not observed in Loa loa. Since these results have been doubted, and because of the medical significance, several independent methods were applied to search for Wolbachia in L. loa. Methods Loa loa and Onchocerca volvulus were studied by electron microscopy, histology with silver staining, and immunohistology using antibodies against WSP, Wolbachia aspartate aminotransferase, and heat shock protein 60. The results achieved with L. loa and O. volvulus were compared. Searching for Wolbachia, genes were amplified by PCR coding for the bacterial 16S rDNA, the FTSZ cell division protein, and WSP. Results No Wolbachia endobacteria were discovered by immunohistology in 13 male and 14 female L. loa worms and in numerous L. loa microfilariae. In contrast, endobacteria were found in large numbers in O. volvulus and 14 other filaria species. No intracellular bacteria were seen in electron micrographs of oocytes and young morulae of L. loa in contrast to O. volvulus. In agreement with these results, Wolbachia DNA was not detected by PCR in three male and six female L. loa worms and in two microfilariae samples of L. loa. Conclusions Loa loa do not harbour obligatory symbiotic Wolbachia endobacteria in essential numbers to enable their efficient vertical transmission or to play a role in production of microfilariae. Exclusively, the filariae cause the immunopathology of loiasis is patients and the adverse side effects after antifilarial chemotherapy. Doxycycline cannot be used to cure loiais but it probably does not represent a risk for L. loa patients when administered to patients with co-infections of onchocerciasis. PMID:12801420

Seroepidemiology of helminths and the association with severe malaria among infants and young children in Tanzania.

PubMed

Kwan, Jennifer L; Seitz, Amy E; Fried, Michal; Lee, Kun-Lin; Metenou, Simon; Morrison, Robert; Kabyemela, Edward; Nutman, Thomas B; Prevots, D Rebecca; Duffy, Patrick E

2018-03-01

The disease burden of Wuchereria bancrofti and Plasmodium falciparum malaria is high, particularly in Africa, and co-infection is common. However, the effects of filarial infection on the risk of severe malaria are unknown. We used the remaining serum samples from a large cohort study in Muheza, Tanzania to describe vector-borne filarial sero-reactivity among young children and to identify associations between exposure to filarial parasites and subsequent severe malaria infections. We identified positive filarial antibody responses (as well as positive antibody responses to Strongyloides stercoralis) among infants as young as six months. In addition, we found a significant association between filarial seropositivity at six months of age and subsequent severe malaria. Specifically, infants who developed severe malaria by one year of age were 3.9 times more likely (OR = 3.9, 95% CI: 1.2, 13.0) to have been seropositive for filarial antigen at six months of age compared with infants who did not develop severe malaria.

The fossil tabanids (Diptera Tabanidae): when they began to appreciate warm blood and when they began transmit diseases?

PubMed

Martins-Neto, Rafael Gioia

2003-01-01

A discussion of the known fossil tabanids (Diptera Tabanidae) is presented based on fossil evidence. This includes the origin of the hemathophagy in the Brachycera, more specifically for tabanids. Several tabanid species in the extant fauna are vectors for disease-producing organisms that affect humans and animals. Bacteria, viruses, rickettsiae, protozoa, and filarial worms can be transmitted by them, causing such diseases as anthrax, tularemia, anaplasmosis, various forms of trypanosomiasis, Q fever, and filariasis. However, if tabanids are directly responsible for all of these diseases is not consensual and the known fossil evidence is presented here.

Evidence of possible natural infections of man with Brugia pahangi in South Kalimantan (Borneo), Indonesia.

PubMed

Palmieri, J R; Ratiwayanto, S; Masbar, S; Tirtokusumo, S; Rusch, J; Marwoto, H A

1985-09-01

Blood from 9 humans, 6 domestic cats (Felis domesticus), and 5 silvered leaf monkeys (Presbytis cristatus) from South Kalimantan (Borneo), Indonesia, with known filarial infections was examined for determination ofacid phosphatase activity of the microfilarae (mff). The findings suggest 1) that Brugia parasites from domestic cats and silvered leaf monkeys can be speciated by acid phosphatase activity and that speciation by acid phosphatase assay corresponds to that based upon adult worm morphology and 2) that Brugia mff from humans have acid phosphatase activity characteristic of that of B. pahangi microfilariae from cat and monkey. Thus B. pahangi may infect man in South Kalimantan.

A computational analysis of the binding mode of closantel as inhibitor of the Onchocerca volvulus chitinase: insights on macrofilaricidal drug design

NASA Astrophysics Data System (ADS)

Segura-Cabrera, Aldo; Bocanegra-García, Virgilio; Lizarazo-Ortega, Cristian; Guo, Xianwu; Correa-Basurto, José; Rodríguez-Pérez, Mario A.

2011-12-01

Onchocerciasis is a leading cause of blindness with at least 37 million people infected and more than 120 million people at risk of contracting the disease; most (99%) of this population, threatened by infection, live in Africa. The drug of choice for mass treatment is the microfilaricidal Mectizan® (ivermectin); it does not kill the adult stages of the parasite at the standard dose which is a single annual dose aimed at disease control. However, multiple treatments a year with ivermectin have effects on adult worms. The discovery of new therapeutic targets and drugs directed towards the killing of the adult parasites are thus urgently needed. The chitinase of filarial nematodes is a new drug target due to its essential function in the metabolism and molting of the parasite. Closantel is a potent and specific inhibitor of chitinase of Onchocerca volvulus (OvCHT1) and other filarial chitinases. However, the binding mode and specificity of closantel towards OvCHT1 remain unknown. In the absence of a crystallographic structure of OvCHT1, we developed a homology model of OvCHT1 using the currently available X-ray structures of human chitinases as templates. Energy minimization and molecular dynamics (MD) simulation of the model led to a high quality of 3D structure of OvCHIT1. A flexible docking study using closantel as the ligand on the binding site of OvCHIT1 and human chitinases was performed and demonstrated the differences in the closantel binding mode between OvCHIT1 and human chitinase. Furthermore, molecular dynamics simulations and free-energy calculation were employed to determine and compare the detailed binding mode of closantel with OvCHT1 and the structure of human chitinase. This comparative study allowed identification of structural features and properties responsible for differences in the computationally predicted closantel binding modes. The homology model and the closantel binding mode reported herein might help guide the rational development of novel drugs against the adult parasite of O. volvulus and such findings could be extrapolated to other filarial neglected diseases.

Filarial parasites develop faster and reproduce earlier in response to host immune effectors that determine filarial life expectancy.

PubMed

Babayan, Simon A; Read, Andrew F; Lawrence, Rachel A; Bain, Odile; Allen, Judith E

2010-10-19

Humans and other mammals mount vigorous immune assaults against helminth parasites, yet there are intriguing reports that the immune response can enhance rather than impair parasite development. It has been hypothesized that helminths, like many free-living organisms, should optimize their development and reproduction in response to cues predicting future life expectancy. However, immune-dependent development by helminth parasites has so far eluded such evolutionary explanation. By manipulating various arms of the immune response of experimental hosts, we show that filarial nematodes, the parasites responsible for debilitating diseases in humans like river blindness and elephantiasis, accelerate their development in response to the IL-5 driven eosinophilia they encounter when infecting a host. Consequently they produce microfilariae, their transmission stages, earlier and in greater numbers. Eosinophilia is a primary host determinant of filarial life expectancy, operating both at larval and at late adult stages in anatomically and temporally separate locations, and is implicated in vaccine-mediated protection. Filarial nematodes are therefore able to adjust their reproductive schedules in response to an environmental predictor of their probability of survival, as proposed by evolutionary theory, thereby mitigating the effects of the immune attack to which helminths are most susceptible. Enhancing protective immunity against filarial nematodes, for example through vaccination, may be less effective at reducing transmission than would be expected and may, at worst, lead to increased transmission and, hence, pathology.

Helminth Genomics: The Implications for Human Health

PubMed Central

Brindley, Paul J.; Mitreva, Makedonka; Ghedin, Elodie; Lustigman, Sara

2009-01-01

More than two billion people (one-third of humanity) are infected with parasitic roundworms or flatworms, collectively known as helminth parasites. These infections cause diseases that are responsible for enormous levels of morbidity and mortality, delays in the physical development of children, loss of productivity among the workforce, and maintenance of poverty. Genomes of the major helminth species that affect humans, and many others of agricultural and veterinary significance, are now the subject of intensive genome sequencing and annotation. Draft genome sequences of the filarial worm Brugia malayi and two of the human schistosomes, Schistosoma japonicum and S. mansoni, are now available, among others. These genome data will provide the basis for a comprehensive understanding of the molecular mechanisms involved in helminth nutrition and metabolism, host-dependent development and maturation, immune evasion, and evolution. They are likely also to predict new potential vaccine candidates and drug targets. In this review, we present an overview of these efforts and emphasize the potential impact and importance of these new findings. PMID:19855829

Epidemiology of elephantiasis with special emphasis on podoconiosis in Ethiopia: A literature review.

PubMed

Yimer, Mulat; Hailu, Tadesse; Mulu, Wondemagegn; Abera, Bayeh

2015-06-01

Elephantiasis is a symptom of a variety of diseases that is characterized by the thickening of the skin and underlying tissues, especially in the legs, male genitals and female breasts. Some conditions having this symptom include: Elephantiasis nostras, due to longstanding chronic lymphangitis; Elephantiasis tropica or lymphatic filariasis, caused by a number of parasitic worms, particularly Wuchereria bancrofti; non-filarial elephantiasis or podoconiosis, an immune disease caused by heavy metals affecting the lymph vessels; proteus syndrome, the genetic disorder of the so-called Elephant Man, etc. Podoconiosis is a type of lower limb tropical elephantiasis distinct from lymphatic filariasis. Lymphatic filariasis affects all population at risk, whereas podoconiosis predominantly affects barefoot subsistence farmers in areas with red volcanic soil. Ethiopia is one of the countries with the highest number of podoconiosis patients since many people are at risk to red-clay soil exposure in many parts of the country. The aim of this review was to know the current status and impact of podoconiosis and its relevance to elephantiasis in Ethiopia. To know the epidemiology and disease burden, the literatures published by different scholars were systematically reviewed. The distribution of the disease and knowledge about filarial elephantiasis and podoconiosis are not well known in Ethiopia. It is relatively well studied in southern Ethiopia but data from other parts of the country are limited. Moreover, programmes that focus on diagnosis, treatment, prevention and control of filarial elephantiasis and podoconiosis are also non-existent even in endemic areas. Furthermore, the disease mapping has not been carried out country-wide. Therefore, in order to address these gaps, Ethiopian Ministry of Health needs to take initiative for undertaking concrete research and mapping of the disease in collaboration with stakeholders.

Prevalence of filarial parasites in domestic and stray cats in Selangor State, Malaysia.

PubMed

Al-Abd, Nazeh M; Nor, Zurainee Mohamed; Kassim, Mustafa; Mansor, Marzida; Al-Adhroey, Abdulelah H; Ngui, Romano; Sivanandam, Sinnadurai

2015-09-01

To determine the prevalence of the filarial parasites,ie.,Brugia malayi, Brugia, Brugia pahangi(B. pahangi), Dirofilaria immitisandDirofilaria repens (D. repens) in domestic and stray cats. A total of 170 blood sample were collected from domestic and stray cats and examined for filarial worm parasites in two localities, Pulau Carey and Bukit Gasing, Selangor State, Malaysia. The overall prevalence of infection was 23.5% (40/170; 95% CI = 17.4-30.6). Of this, 35% (14/40; 95% CI = 22.1-50.5) and 50% (20/40; 95% CI = 35.2-64.8) were positive for single B. pahangi nd D. repens, respectively. The remaining of 15% (6/40; 95% CI = 7.1-29.1) were positive for mixed B. pahangi and D. repens. In addition, 75% of the infected cats were domestic, and 25% were strays. No Brugia malayi and Dirofilaria immitis was detected. Eighty-four cats were captured at Pulau Carey, of which 35.7% (30/84) were infected. Among the cats determined to be infected, 93% (28/30; 95% CI = 78.7-98.2) were domestic, and only 6.7% (2/30; 95% CI = 19.0-21.3) were strays. Conversely, the number of infected cats was three times lower in Bukit Gasing than in Pulau Carey, and most of the cats were stray. B. pahangi and D. repens could be the major parasites underlying filariasis in the study area. Adequate prophylactic plans should be administrated in the cat population in study area. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Zoonotic ocular onchocercosis caused by Onchocerca lupi in dogs in Romania.

PubMed

Tudor, Poliana; Turcitu, Mihai; Mateescu, Cosmin; Dantas-Torres, Filipe; Tudor, Niculae; Bărbuceanu, Florica; Ciuca, Lavinia; Burcoveanu, Ioana; Acatrinei, Dumitru; Rinaldi, Laura; Mateescu, Romanița; Bădicu, Adina; Ionașcu, Iuliana; Otranto, Domenico

2016-02-01

Onchocerca lupi is a filarial nematode, which infects the scleral conjunctival tissue of dogs, wolves and cats. Whilst adult nematodes localize in the conjunctive tissue of sclera or in the retrobulbar, microfilariae are found in the skin, and they are rarely diagnosed in asymptomatic animals. Since the first report of human ocular infection 5 years ago, up to 10 zoonotic cases have been identified in patients worldwide. We report, for the first time in Romania, three cases of canine ocular onchocercosis in dogs. Fragments of the harvested worms were characterized morphologically and molecularly. This article expands knowledge on the distribution of this parasite in Eastern Europe and sounds an alarm bell for ophthalmologists about the possible occurrence of human cases of O. lupi infection.

Maternal Filarial Infection Influences the Development of Regulatory T Cells in Children from Infancy to Early Childhood.

PubMed

Bal, Madhusmita; Ranjit, Manoranjan; Achary, K Gopinath; Satapathy, Ashok K

2016-11-01

Children born from filarial infected mothers are comparatively more susceptible to filarial infection than the children born to uninfected mothers. But the mechanism of such increased susceptibility to infection in early childhood is not exactly known. Several studies have shown the association of active filarial infection with T cell hypo-responsiveness which is mediated by regulatory T cells (Tregs). Since the Tregs develop in the thymus from CD4+ CD25hi thymocytes at an early stage of the human fetus, it can be hypothesized that the maternal infection during pregnancy affects the development of Tregs in children at birth as well as early childhood. Hence the present study was designed to test the hypothesis by selecting a cohort of pregnant mothers and children born to them subsequently in a filarial endemic area of Odisha, India. A total number of 49 pregnant mothers and children born to them subsequently have been followed up (mean duration 4.4 years) in an area where the microfilariae (Mf) rate has come down to <1% after institution of 10 rounds of annual mass drug administration (MDA). The infection status of mother, cord and children were assessed through detection of microfilariae (Mf) and circulating filarial antigen (CFA). Expression of Tregs cells were measured by flow cytometry. The levels of IL-10 were evaluated by using commercially available ELISA kit. A significantly high level of IL-10 and Tregs have been observed in children born to infected mother compared to children of uninfected mother at the time of birth as well as during early childhood. Moreover a positive correlation between Tregs and IL-10 has been observed among the children born to infected mother. From these observations we predict that early priming of the fetal immune system by filarial antigens modulate the development of Tregs, which ultimately scale up the production of IL-10 in neonates and creates a milieu for high rate of acquisition of infection in children born to infected mothers. The mechanism of susceptibility and implication of the results in global elimination programme of filariasis has been discussed.

Maternal Filarial Infection Influences the Development of Regulatory T Cells in Children from Infancy to Early Childhood

PubMed Central

Bal, Madhusmita; Ranjit, Manoranjan; Achary, K. Gopinath; Satapathy, Ashok K.

2016-01-01

Background Children born from filarial infected mothers are comparatively more susceptible to filarial infection than the children born to uninfected mothers. But the mechanism of such increased susceptibility to infection in early childhood is not exactly known. Several studies have shown the association of active filarial infection with T cell hypo-responsiveness which is mediated by regulatory T cells (Tregs). Since the Tregs develop in the thymus from CD4+ CD25hi thymocytes at an early stage of the human fetus, it can be hypothesized that the maternal infection during pregnancy affects the development of Tregs in children at birth as well as early childhood. Hence the present study was designed to test the hypothesis by selecting a cohort of pregnant mothers and children born to them subsequently in a filarial endemic area of Odisha, India. Methodology and Principal finding A total number of 49 pregnant mothers and children born to them subsequently have been followed up (mean duration 4.4 years) in an area where the microfilariae (Mf) rate has come down to <1% after institution of 10 rounds of annual mass drug administration (MDA). The infection status of mother, cord and children were assessed through detection of microfilariae (Mf) and circulating filarial antigen (CFA). Expression of Tregs cells were measured by flow cytometry. The levels of IL-10 were evaluated by using commercially available ELISA kit. A significantly high level of IL-10 and Tregs have been observed in children born to infected mother compared to children of uninfected mother at the time of birth as well as during early childhood. Moreover a positive correlation between Tregs and IL-10 has been observed among the children born to infected mother. Significance From these observations we predict that early priming of the fetal immune system by filarial antigens modulate the development of Tregs, which ultimately scale up the production of IL-10 in neonates and creates a milieu for high rate of acquisition of infection in children born to infected mothers. The mechanism of susceptibility and implication of the results in global elimination programme of filariasis has been discussed. PMID:27861499

Assessment of Blood Collection from the Lateral Saphenous Vein for Microfilaria Counts in Mongolian Gerbils (Meriones unguiculatus) Infected with Brugia pahangi

PubMed Central

Alworth, Leanne C; Berghaus, Roy D; Kelly, Lisa M; Supakorndej, Prasit; Burkman, Erica J; Savadelis, Molly D; Cooper, Tanya L; Salyards, Gregory W; Harvey, Stephen B; Moorhead, Andrew R

2015-01-01

The NIH guidelines for survival bleeding of mice and rats note that using the retroorbital plexus has a greater potential for complications than do other methods of blood collection and that this procedure should be performed on anesthetized animals. Lateral saphenous vein puncture has a low potential for complications and can be performed without anesthesia. Mongolian gerbils (Meriones unguiculatus) are the preferred rodent model for filarial parasite research. To monitor microfilaria counts in the blood, blood sampling from the orbital plexus has been the standard. Our goal was to refine the blood collection technique. To determine whether blood collection from the lateral saphenous vein was a feasible alternative to retroorbital sampling, we compared microfilaria counts in blood samples collected by both methods from 21 gerbils infected with the filarial parasitic worm Brugia pahangi. Lateral saphenous vein counts were equivalent to retroorbital counts at relatively high counts (greater than 50 microfilariae per 20 µL) but were significantly lower than retroorbital counts when microfilarial concentrations were lower. Our results indicate that although retroorbital collection may be preferable when low concentrations of microfilariae need to be enumerated, the lateral saphenous vein is a suitable alternative site for blood sampling to determine microfilaremia and is a feasible refinement that can benefit the wellbeing of gerbils. PMID:26678366

The Chemokine CXCL12 Is Essential for the Clearance of the Filaria Litomosoides sigmodontis in Resistant Mice

PubMed Central

Attout, Tarik; Ehrhardt, Katharina; Lhermitte-Vallarino, Nathaly; Hachet-Haas, Muriel; Galzi, Jean Luc; Brotin, Emilie; Bachelerie, Françoise; Gavotte, Laurent; Moulia, Catherine; Bain, Odile; Martin, Coralie

2012-01-01

Litomosoides sigmodontis is a cause of filarial infection in rodents. Once infective larvae overcome the skin barrier, they enter the lymphatic system and then settle in the pleural cavity, causing soft tissue infection. The outcome of infection depends on the parasite's modulatory ability and also on the immune response of the infected host, which is influenced by its genetic background. The goal of this study was to determine whether host factors such as the chemokine axis CXCL12/CXCR4, which notably participates in the control of immune surveillance, can influence the outcome of the infection. We therefore set up comparative analyses of subcutaneous infection by L. sigmodontis in two inbred mouse strains with different outcomes: one susceptible strain (BALB/c) and one resistant strain (C57BL/6). We showed that rapid parasite clearance was associated with a L. sigmodontis-specific CXCL12-dependent cell response in C57BL/6 mice. CXCL12 was produced mainly by pleural mesothelial cells during infection. Conversely, the delayed parasite clearance in BALB/c mice was neither associated with an increase in CXCL12 levels nor with cell influx into the pleural cavity. Remarkably, interfering with the CXCL12/CXCR4 axis in both strains of mice delayed filarial development, as evidenced by the postponement of the fourth molting process. Furthermore, the in vitro growth of stage 4 filariae was favored by the addition of low amounts of CXCL12. The CXCL12/CXCR4 axis thus appears to have a dual effect on the L. sigmodontis life cycle: by acting as a host-cell restriction factor for infection, and as a growth factor for worms. PMID:22511975

Natural infection of Culex theileri (Diptera: Culicidae) with Dirofilaria immitis (Nematoda: Filarioidea) on Madeira Island, Portugal.

PubMed

Santa-Ana, Marta; Khadem, Manhaz; Capela, Ruben

2006-01-01

Field and laboratory studies were performed to verify whether Culex theileri Theobald functions as a natural vector of Dirofilaria immitis (Leidy) on Madeira Island, Portugal. CO2-baited light traps (EVS traps) were use to sample mosquitoes monthly basis between February 2002 and February 2003 in the area of Quebradas (Funchal). Three mosquito species were captured, including 58 Culex pipiens L., 790 Cx. theileri, and three Culiseta longiareolata (Macquart). Only C. theileri tested positive for D. immitis. The presence of this filarial worm was detected by direct observation, infectivity assay dissection technique, and polymerase chain reaction methods. Infected mosquitoes were recovered in October and December 2002 and January 2003. These data provide evidence that Cx. theileri could be the main vector of D. immitis in Funchal, Madeira.

Copper(II) oxide nanoparticles augment antifilarial activity of Albendazole: In vitro synergistic apoptotic impact against filarial parasite Setaria cervi.

PubMed

Zafar, Atif; Ahmad, Irshad; Ahmad, Ajaz; Ahmad, Masood

2016-03-30

Mass treatment of lymphatic filariasis with Albendazole (ABZ), a therapeutic benzimidazole, is fraught with serious limitations such as possible drug resistance and poor macrofilaricidal activity. Therefore, we need to develop new ABZ-based formulations to improve its antifilarial effectiveness. CuO nanoparticles were used as an adjuvant with ABZ to form ABZ-CuO nanocomposite, which was characterized by UV-vis spectroscopy, FT-IR, AFM and SEM. Antifilarial activity of nanocomposite was evaluated using relative motility assay and dye exclusion test in dark and under UV light. ROS generation, antioxidant levels, lipid peroxidation and DNA fragmentation in nanocomposite treated parasites were estimated. Biophysical techniques were employed to ascertain the mode of binding of nanocomposite to parasitic DNA. Nanocomposite increases parasite mortality as compared to ABZ in dark, and its antifilarial effect was increased further under UV light. Elevated ROS production and decline of parasitic-GST and GSH levels were observed in nanocomposite treated worms in dark, and these effects were pronounced further under UV light. Nanocomposite leads to higher DNA fragmentation as compared to ABZ alone. Further, we found that nanocomposite binds parasitic DNA in an intercalative manner where it generates ROS to induce DNA damage. Thus, oxidative stress production due to ROS generation and consequent DNA fragmentation leads to apoptosis in worms. This is the first report supporting CuO nanoparticles as a potential adjuvant with ABZ against filariasis along with enhanced antifilarial activity of nanocomposite under UV light. These findings, thus, indicate that development of ABZ-loaded nanoparticle compounds may serve as promising leads for filariasis treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Dirofilaria immitis infection of a snow leopard (Uncia uncia) in a Japanese zoo with mitochondrial DNA analysis.

PubMed

Murata, Koichi; Yanai, Tokuma; Agatsuma, Takeshi; Uni, Shigehiko

2003-08-01

Three dog heartworms (Dirofilaria immitis) were detected in the lumen of the right cardiac ventriculus and of the pulmonary artery of a captive female snow leopard (Uncia uncia) that died of pancreatic carcinoma at a zoo in Japan. Neither clinical respiratory nor circulatory symptoms caused by the heartworm infection were observed. The filarial worms were identified as D. immitis from the morphologic characteristics of the esophagus, the presence of faint longitudinal ridges on the cuticular surface, the situation of vulva posterior to the esophagus, and the measurements of the body. The heartworms from the snow leopard were identical to that of D. immitis from dogs in the sequence of the cytochrome oxidase I region in the mitochondrial DNA. This host record is the first of D. immitis in U. uncia.

Parasitic pulmonary eosinophilia.

PubMed

Chitkara, Rajinder K; Krishna, Ganesh

2006-04-01

Parasitic infections, although common in tropical and subtropical regions, are prevalent worldwide because of changing immigration patterns and in international travel. The burden of worm infection is enormous and the intensity of infection is usually high among the poor and in immunocompromised individuals. Pulmonary eosinophilia occurs in almost all metazoan infections. In the Western world, the most common infections are caused by Strongyloides, Ascaris, Toxocara, and Ancylostoma species. Most of the nematodes multiply within the human host and cause pulmonary eosinophilia during larval migration through the lungs. Despite larval migration through the lungs, there is usually no permanent lung damage. The result is an increased number of eosinophils in the airways or lung parenchyma with or without peripheral eosinophilia. Löffler's syndrome, visceral larva migrans, and tropical pulmonary eosinophilia are the most common infections that cause pulmonary eosinophilia. The most serious parasitic eosinophilic lung disease is tropical pulmonary eosinophilia, a disorder caused by the filarial worms Wuchereria bancrofti and Brugia malayi, in which cases have typically been reported to masquerade acute or refractory bronchial asthma. Increasing awareness, newer diagnostic techniques, preventative measures, and antiparasitic drugs are important in reducing the worldwide morbidity and mortality from parasitic helminths and protozoa. This review focuses on common and some uncommon causes of pulmonary parasitic eosinophilia and their manifestations, diagnosis, and management.

Rickettsiae, protozoa, and opisthokonta/metazoa.

PubMed

Schmutzhard, Erich; Helbok, Raimund

2014-01-01

Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities. © 2014 Elsevier B.V. All rights reserved.

Case Report: Filaria or Megasperm? A Cause of an Ultrasonographic "Filarial Dance Sign".

PubMed

Wiggers, J Brad; Jang, Hyun-Jung; Keystone, Jay S

2018-05-14

Bancroftian filariasis can cause genital abnormalities related to chronic inflammation and obstruction of the afferent lymphatic vessels, and may demonstrate a "filarial dance sign" on scrotal ultrasound with mobile echogenic particles observed. We present a patient with a positive "filarial dance sign," travel within Latin America and negative filarial serology.

Identification of anti-filarial leads against aspartate semialdehyde dehydrogenase of Wolbachia endosymbiont of Brugia malayi: combined molecular docking and molecular dynamics approaches.

PubMed

Amala, Mathimaran; Rajamanikandan, Sundaraj; Prabhu, Dhamodharan; Surekha, Kanagarajan; Jeyakanthan, Jeyaraman

2018-02-06

Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents. In this present study, molecular modeling combined with molecular dynamics simulations and structure-based virtual screening were performed to identify potent lead molecules against ASDase. Based on Glide score, toxicity profile, binding affinity and mode of interactions with the ASDase, five potent lead molecules were selected. The molecular docking and dynamics results revealed that the amino acid residues Arg103, Asn133, Cys134, Gln161, Ser164, Lys218, Arg239, His246, and Asn321 plays a crucial role in effective binding of Top leads into the active site of ASDase. The stability of the ASDase-lead complexes was confirmed by running the 30 ns molecular dynamics simulations. The pharmacokinetic properties of the identified lead molecules are in the acceptable range. Furthermore, density functional theory and binding free energy calculations were performed to rank the lead molecules. Thus, the identified lead molecules can be used for the development of anti-filarial agents to combat the pathogenecity of Brugia malayi.

Circulating filarial antigen in the hydrocele fluid from individuals living in a bancroftian filariasis area - Recife, Brazil: detected by the monoclonal antibody Og4C3-assay.

PubMed

Rocha, Abraham; Lima, Guilherme; Medeiros, Zulma; Aguiar-Santos, Ana; Alves, Sandra; Montarroyos, Ulisses; Oliveira, Paula; Béliz, Fátima; Netto, Maria José; Furtado, André

2004-02-01

The purpose of this study was to examine the circulating filarial antigen (CFA) detected by the monoclonal antibody (mAb) Og4C3-ELISA in paired samples of serum and hydrocele fluid from 104 men with hydrocele, living in an endemic area of Wuchereria bancrofti. Nocturnal blood specimens were filtered and examined for microfilariae (MF) and ultrasound was used in order to identify the presence of adult worms (the filaria dance sign - FDS) in the lymphatic vessels of the scrotal area. Four groups were selected according to their parasitological status: group I - 71 MF- and FDS-; group II - 21 MF+ and FDS+; group III - 10 MF- and FDS+ and group IV- 2 MF+ and FDS-. CFA was identified simultaneously (fluid and serum) in 11 (15.5%), 21 (100%), 3 (30%), and 1 (50%) in groups I, II, III, and IV, respectively. In despite of high CFA+ level (antigen Og4C3) units/ml, the Geometrical Mean (GM) = 2696) in the sera of these 36/104 paired samples, when compared to the hydrocele fluid, (GM = 1079), showed a very good correlation between the CFA level in the serum and CFA level in the fluid (r = 0.731). CFA level in the serum of the 23 microfilaremics (groups II and IV) was extremely high (GM = 4189) and was correlated with MF density (r = 0.442). These findings report for the first time the potential alternative use of the hydrocele fluid to investigate CFA using the mAb Og4C3-ELISA.

Rhizome extracts of Curcuma zedoaria Rosc induce caspase dependant apoptosis via generation of reactive oxygen species in filarial parasite Setaria digitata in vitro.

PubMed

Senathilake, K S; Karunanayake, E H; Samarakoon, S R; Tennekoon, K H; de Silva, E D

2016-08-01

Human lymphatic filariasis (LF) is mainly caused by filarial parasite Wuchereria bancrofti and is the second leading cause of long term and permanent disability in tropical countries. To date, incapability to eliminate long lived adult parasites by current drugs remains the major challenge in the elimination of LF. Hence, in the current study, the efficacy of rhizome extracts of Curcuma zedoaria (a plant traditionally used in Sri Lanka in the management of LF) was evaluated as an effective filaricide in vitro. Sequential solvent extracts of C. zedoaria rhizomes were screened for in vitro antifilarial activity at 0.01-1 mg/mL concentrations by motility inhibition assay and 3-(4, 5 dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) reduction assay using cattle parasite Setaria digitata as a model organism. Exposure of parasites to hexane and chloroform extracts of C. zedoaria caused a dose dependant reduction in motility and viability of microfilariae (IC50 = 72.42 μg/mL for hexane extract, 191.14 μg/mL for chloroform extract) and adult parasites (IC50 = 77.07 μg/mL for hexane extract, 259.87 μg/mL for chloroform extract). Both extracts were less toxic to human peripheral blood mononuclear cells when compared to filariae. A dose dependant increase in caspase 3/CED 3 and a decrease in total protein content, cyclooxygenase (COX) and protein tyrosine phosphatase (PTP) activities were observed in adult parasites treated with hexane or chloroform extract. A significant degree of chromatin condensation and apoptotic body formation were also observed in these worms by Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) staining respectively. Dose dependant chromosomal DNA laddering was observed in treated adult worms but not in microfilariae in response to both extracts. Oxidative stress parameters such as reduction in reduced glutathione (GSH) levels and increase in glutathione s transferase (GST), superoxide dismutase (SOD) and catalase activities, increased reactive oxygen levels (ROS) and lipid peroxidation were also observed indicating that an apoptotic event is induced by reactive oxygen species. Copyright © 2016 Elsevier Inc. All rights reserved.

Parasitological, serological, and clinical evidence for high prevalence of podoconiosis (non-filarial elephantiasis) in Midakegn district, central Ethiopia

PubMed Central

Oli, Geleta Geshere; Ayele, Fasil Tekola; Petros, Beyene

2012-01-01

OBJECTIVE Both podoconiosis (a geochemical non-filarial disease) and chronic filarial disease result in lower limb elephantiasis. The aims of the present study were to determine whether the elephantiasis in Midakegn district, central Ethiopia is filarial or non-filarial (podoconiosis) using serological, parasitological, and clinical examinations, and to estimate its prevalence. METHODS House-to-house visits were made in 330 randomly selected households. All household members that had elephantiasis were interviewed and clinically examined at the nearby health center to confirm presence of elephantiasis, check presence of scrotal swelling, and rule out other causes of lymphoedema. Midnight blood sample was obtained from each participant with elephantiasis for microscopic examination of W. bancrofti microfilaria. Day time blood sample was obtained from half of the participants for serological confirmation using the immuno-chromatographic test card. RESULTS Consistent with features of podoconiosis (non-filarial elephantiasis), none of the elephantiasis cases had consistently worn shoes since childhood; 94.3% had bilateral swelling limited below the level of the knees; no individual had thigh or scrotal elephantiasis; parasitological test for microfilariae and serological tests for W. bancrofti antigen turned negative in all samples. The prevalence of the disease was 7.4%. Prevalence peaked in the third decade of life, which also includes the most economically active age groups. CONCLUSIONS This study has shown high prevalence of podoconiosis (endemic non-filarial elephantiasis) and absence of filarial elephantiasis in Midakegn district. Prevention, treatment, and control of podoconiosis must be among the top priorities of public health programs in the district. PMID:22487446

Human innate lymphoid cells (ILCs) in filarial infections.

PubMed

Bonne-Année, S; Nutman, T B

2018-02-01

Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Immunodiagnostic Properties of Wucheraria bancrofti SXP-1, a Potential Filarial Diagnostic Candidate Expressed in Tobacco Plant, Nicotiana tabacum.

PubMed

Ganapathy, Mathangi; Chakravarthi, M; Charles, S Jason; Harunipriya, P; Jaiganesh, S; Subramonian, N; Kaliraj, P

2015-08-01

Transgenic tobacco plants were developed expressing WbSXP-1, a diagnostic antigen isolated from the cDNA library of L3 stage larvae of Wucheraria bancrofti. This antigen produced by recombinant Escherichia coli has been demonstrated by to be successful as potential diagnostic candidate against lymphatic filariasis. A rapid format simple and qualitative flow through immune-filtration diagnostic kit has been developed for the identification of IgG antibodies to the recombinant WbSXP-1 and is being marketed by M/S Span Diagnostics Ltd in India and Africa. Here, we present the results of experiments on the transformation and expression of the same filarial antigen, WbSXP-1, in tobacco plant, Nicotiana tabacum, to produce plant-based diagnostic antigen. It was possible to successfully transform the tobacco plant with WbSXP-1, the integration of the parasite-specific gene in plants was confirmed by PCR amplification and the expression of the filarial protein by Western blotting. The immunoreactivity of the plant-produced WbSXP-1 was assessed based on its reaction with the monoclonal antibodies developed against the E. coli-produced protein. Immunological screening using clinical sera from patients indicates that the plant-produced protein is comparable to E. coli-produced diagnostic antigen. The result demonstrated that plants can be used as suitable expression systems for the production of diagnostic proteins against lymphatic filariasis, a neglected tropical infectious disease which has a negative impact on socioeconomic development. This is the first report of the integration, expression and efficacy of a diagnostic candidate of lymphatic filariasis in plants.Key MessageTransgenic tobacco plants with WbSXP-1, a filarial diagnostic candidate, were developed. The plant-produced protein showed immunoreactivity on par with the E. coli product.

Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis

PubMed Central

Darby, Alistair C.; Armstrong, Stuart D.; Bah, Germanus S.; Kaur, Gaganjot; Hughes, Margaret A.; Kay, Suzanne M.; Koldkjær, Pia; Rainbow, Lucille; Radford, Alan D.; Blaxter, Mark L.; Tanya, Vincent N.; Trees, Alexander J.; Cordaux, Richard; Wastling, Jonathan M.; Makepeace, Benjamin L.

2012-01-01

The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response. PMID:22919073

Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

PubMed Central

Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

2015-01-01

Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

wALADin benzimidazoles differentially modulate the function of porphobilinogen synthase orthologs.

PubMed

Lentz, Christian S; Halls, Victoria S; Hannam, Jeffrey S; Strassel, Silke; Lawrence, Sarah H; Jaffe, Eileen K; Famulok, Michael; Hoerauf, Achim; Pfarr, Kenneth M

2014-03-27

The heme biosynthesis enzyme porphobilinogen synthase (PBGS) is a potential drug target in several human pathogens. wALADin1 benzimidazoles have emerged as species-selective PBGS inhibitors against Wolbachia endobacteria of filarial worms. In the present study, we have systematically tested wALADins against PBGS orthologs from bacteria, protozoa, metazoa, and plants to elucidate the inhibitory spectrum. However, the effect of wALADin1 on different PBGS orthologs was not limited to inhibition: several orthologs were stimulated by wALADin1; others remained unaffected. We demonstrate that wALADins allosterically modulate the PBGS homooligomeric equilibrium with inhibition mediated by favoring low-activity oligomers, while 5-aminolevulinic acid, Mg(2+), or K(+) stabilized high-activity oligomers. Pseudomonas aeruginosa PBGS could be inhibited or stimulated by wALADin1 depending on these factors and pH. We have defined the wALADin chemotypes responsible for either inhibition or stimulation, facilitating the design of tailored PBGS modulators for potential application as antimicrobial agents, herbicides, or drugs for porphyric disorders.

wALADin Benzimidazoles Differentially Modulate the Function of Porphobilinogen Synthase Orthologs

PubMed Central

2015-01-01

The heme biosynthesis enzyme porphobilinogen synthase (PBGS) is a potential drug target in several human pathogens. wALADin1 benzimidazoles have emerged as species-selective PBGS inhibitors against Wolbachia endobacteria of filarial worms. In the present study, we have systematically tested wALADins against PBGS orthologs from bacteria, protozoa, metazoa, and plants to elucidate the inhibitory spectrum. However, the effect of wALADin1 on different PBGS orthologs was not limited to inhibition: several orthologs were stimulated by wALADin1; others remained unaffected. We demonstrate that wALADins allosterically modulate the PBGS homooligomeric equilibrium with inhibition mediated by favoring low-activity oligomers, while 5-aminolevulinic acid, Mg2+, or K+ stabilized high-activity oligomers. Pseudomonas aeruginosa PBGS could be inhibited or stimulated by wALADin1 depending on these factors and pH. We have defined the wALADin chemotypes responsible for either inhibition or stimulation, facilitating the design of tailored PBGS modulators for potential application as antimicrobial agents, herbicides, or drugs for porphyric disorders. PMID:24568185

Withania somnifera chemotypes NMITLI 101R, NMITLI 118R, NMITLI 128R and withaferin A protect Mastomys coucha from Brugia malayi infection.

PubMed

Kushwaha, S; Soni, V K; Singh, P K; Bano, N; Kumar, A; Sangwan, R S; Misra-Bhattacharya, S

2012-04-01

Withania somnifera is an ayurvedic Indian medicinal plant whose immunomodulatory activities have been widely used as a home remedy for several ailments. We recently observed immunostimulatory properties in the root extracts of chemotypes NMITLI-101, NMITLI-118, NMITLI-128 and pure withanolide, withaferin A. In the present study, we evaluated the potential immunoprophylactic efficacies of these extracts against an infective pathogen. Our results show that administration of aqueous ethanol extracts (10 mg/kg) and withaferin A (0·3 mg/kg), 7 days before and after challenge with human filarial parasite Brugia malayi, offers differential protection in Mastomys coucha with chemotype 101R offering best protection (53·57%) as compared to other chemotypes. Our findings also demonstrate that establishment of B. malayi larvae was adversely affected by pretreatment with withaferin A as evidenced by 63·6% reduction in adult worm establishment. Moreover, a large percentage of the established female worms (66·2%) also showed defective embryogenesis. While the filaria-specific immunological response induced by withaferin A and NMITLI-101 showed a mixed Th1/Th2 phenotype, 118R stimulated production of IFN-γ and 128R increased levels of IL-4. Taken together, our findings reveal potential immunoprophylactic properties of W. somnifera, and further studies are needed to ascertain the benefits of this plant against other pathogens as well. © 2012 Blackwell Publishing Ltd.

Lymphatic Vascularisation and Involvement of Lyve-1+ Macrophages in the Human Onchocerca Nodule

PubMed Central

Attout, Tarik; Hoerauf, Achim; Dénécé, Gaëlle; Debrah, Alexander Yaw; Marfo-Debrekyei, Yeboah; Boussinesq, Michel; Wanji, Samuel; Martinez, Valérie; Mand, Sabine; Adjei, Ohene; Bain, Odile

2009-01-01

Onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is a parasitic disease leading to debilitating skin disease and blindness, with major economic and social consequences. The pathology of onchocerciasis is principally considered to be a consequence of long-standing host inflammatory responses. In onchocerciasis a subcutaneous nodule is formed around the female worms, the core of which is a dense infiltrate of inflammatory cells in which microfilariae are released. It has been established that the formation of nodules is associated with angiogenesis. In this study, we show using specific markers of endothelium (CD31) and lymphatic endothelial cells (Lyve-1, Podoplanin) that not only angiogenesis but also lymphangiogenesis occurs within the nodule. 7% of the microfilariae could be found within the lymphatics, but none within blood vessels in these nodules, suggesting a possible route of migration for the larvae. The neovascularisation was associated with a particular pattern of angio/lymphangiogenic factors in nodules of onchocerciasis patients, characterized by the expression of CXCL12, CXCR4, VEGF-C, Angiopoietin-1 and Angiopoietin-2. Interestingly, a proportion of macrophages were found to be positive for Lyve-1 and some were integrated into the endothelium of the lymphatic vessels, revealing their plasticity in the nodular micro-environment. These results indicate that lymphatic as well as blood vascularization is induced around O. volvulus worms, either by the parasite itself, e.g. by the release of angiogenic and lymphangiogenic factors, or by consecutive host immune responses. PMID:20011036

Diversity, Host Specialization, and Geographic Structure of Filarial Nematodes Infecting Malagasy Bats.

PubMed

Ramasindrazana, Beza; Dellagi, Koussay; Lagadec, Erwan; Randrianarivelojosia, Milijaona; Goodman, Steven M; Tortosa, Pablo

2016-01-01

We investigated filarial infection in Malagasy bats to gain insights into the diversity of these parasites and explore the factors shaping their distribution. Samples were obtained from 947 individual bats collected from 52 sites on Madagascar and representing 31 of the 44 species currently recognized on the island. Samples were screened for the presence of micro- and macro-parasites through both molecular and morphological approaches. Phylogenetic analyses showed that filarial diversity in Malagasy bats formed three main groups, the most common represented by Litomosa spp. infecting Miniopterus spp. (Miniopteridae); a second group infecting Pipistrellus cf. hesperidus (Vespertilionidae) embedded within the Litomosoides cluster, which is recognized herein for the first time from Madagascar; and a third group composed of lineages with no clear genetic relationship to both previously described filarial nematodes and found in M. griveaudi, Myotis goudoti, Neoromicia matroka (Vespertilionidae), Otomops madagascariensis (Molossidae), and Paratriaenops furculus (Hipposideridae). We further analyzed the infection rates and distribution pattern of Litomosa spp., which was the most diverse and prevalent filarial taxon in our sample. Filarial infection was disproportionally more common in males than females in Miniopterus spp., which might be explained by some aspect of roosting behavior of these cave-dwelling bats. We also found marked geographic structure in the three Litomosa clades, mainly linked to bioclimatic conditions rather than host-parasite associations. While this study demonstrates distinct patterns of filarial nematode infection in Malagasy bats and highlights potential drivers of associated geographic distributions, future work should focus on their alpha taxonomy and characterize arthropod vectors.

An Impossible Journey? The Development of Plasmodium falciparum NF54 in Culex quinquefasciatus

PubMed Central

Knöckel, Julia; Molina-Cruz, Alvaro; Fischer, Elizabeth; Muratova, Olga; Haile, Ashley; Barillas-Mury, Carolina; Miller, Louis H.

2013-01-01

Although Anopheles mosquitoes are the vectors for human Plasmodium spp., there are also other mosquito species–among them culicines (Culex spp., Aedes spp.)–present in malaria-endemic areas. Culicine mosquitoes transmit arboviruses and filarial worms to humans and are vectors for avian Plasmodium spp., but have never been observed to transmit human Plasmodium spp. When ingested by a culicine mosquito, parasites could either face an environment that does not allow development due to biologic incompatibility or be actively killed by the mosquito’s immune system. In the latter case, the molecular mechanism of killing must be sufficiently powerful that Plasmodium is not able to overcome it. To investigate how human malaria parasites develop in culicine mosquitoes, we infected Culex quinquefasciatus with Plasmodium falciparum NF54 and monitored development of parasites in the blood bolus and midgut epithelium at different time points. Our results reveal that ookinetes develop in the midgut lumen of C. quinquefasciatus in slightly lower numbers than in Anopheles gambiae G3. After 30 hours, parasites have invaded the midgut and can be observed on the basal side of the midgut epithelium by confocal and transmission electron microscopy. Very few of the parasites in C. quinquefasciatus are alive, most of them are lysed. Eight days after the mosquito’s blood meal, no oocysts can be found in C. quinquefasciatus. Our results suggest that the mosquito immune system could be involved in parasite killing early in development after ookinetes have crossed the midgut epithelium and come in contact with the mosquito hemolymph. PMID:23658824

Development and testing of a de novo clinical staging system for podoconiosis (endemic non-filarial elephantiasis)

PubMed Central

Tekola, Fasil; Ayele, Zewdu; HaileMariam, Dereje; Fuller, Claire; Davey, Gail

2010-01-01

Summary Background Podoconiosis (endemic non-filarial elephantiasis) is a geochemical disease in individuals exposed to red-clay soil. Despite the prevalence and public health importance of podoconiosis, there is as yet no accepted clinical staging system. Objective We aimed to develop and test a robust clinical staging system for podoconiosis. Methods We adapted the Dreyer system for staging filarial lymphoedema and tested it in four re-iterative field tests conducted in an area of high podoconiosis prevalence in Southern Ethiopia. The system finally arrived at has five stages according to proximal spread of disease and presence of dermal nodules, ridges and bands. We measured the one-week repeatability and the inter-observer agreement of the final staging system. Results We have developed a five-stage system that is readily understood by community workers with little health training. Kappa for one-week repeatability was 0.88 (95% CI 0.80 to 0.96), Kappa for agreement between health professionals was 0.71 (95% CI 0.60 to 0.82), while that between health professionals and community podoconiosis agents without formal health training averaged 0.64 (95% CI 0.52 to 0.78). Conclusions A simple staging system with good inter-observer agreement and repeatability has been developed to assist in the management and further study of podoconiosis. PMID:18721188

Diagnostic clinical parasitology: IV. Identification of the blood parasites?

PubMed

Garcia, L S; Voge, M

1981-01-01

This is the fourth article in a series of articles entitled "Diagnostic Clinical Parasitology" and contains information on the recovery and identification of human blood parasites. The organisms covered include those that cause the diseases malaria, babesiosis, leishmaniasis, and trypanosomiasis. Some of the filarial worms, which can be considered "blood parasites," have been discussed in the third article in the series, "Identification of the Helminths." Although some of these organisms may rarely be encountered in the laboratory in clinical specimens, they will probably have to be identified in proficiency testing specimens, some of which may not always be representative of patient clinical material. The differences between potential organism recovery from patients coming from endemic areas and from those individuals who become infected with no prior exposure to the organism will also be emphasized. Often, for a number of different reasons, organism recovery and subsequent identification may be more difficult than the textbook imply. It is very important for the technologist to recognize this fact, particularly when dealing with a possibly fatal infection, ie, Plasmodium falciparum.

Comparative Analysis of the Secretome from a Model Filarial Nematode (Litomosoides sigmodontis) Reveals Maximal Diversity in Gravid Female Parasites*

PubMed Central

Armstrong, Stuart D.; Babayan, Simon A.; Lhermitte-Vallarino, Nathaly; Gray, Nick; Xia, Dong; Martin, Coralie; Kumar, Sujai; Taylor, David W.; Blaxter, Mark L.; Wastling, Jonathan M.; Makepeace, Benjamin L.

2014-01-01

Filarial nematodes (superfamily Filarioidea) are responsible for an annual global health burden of ∼6.3 million disability-adjusted life-years, which represents the greatest single component of morbidity attributable to helminths affecting humans. No vaccine exists for the major filarial diseases, lymphatic filariasis and onchocerciasis; in part because research on protective immunity against filariae has been constrained by the inability of the human-parasitic species to complete their lifecycles in laboratory mice. However, the rodent filaria Litomosoides sigmodontis has become a popular experimental model, as BALB/c mice are fully permissive for its development and reproduction. Here, we provide a comprehensive analysis of excretory-secretory products from L. sigmodontis across five lifecycle stages and identifications of host proteins associated with first-stage larvae (microfilariae) in the blood. Applying intensity-based quantification, we determined the abundance of 302 unique excretory-secretory proteins, of which 64.6% were present in quantifiable amounts only from gravid adult female nematodes. This lifecycle stage, together with immature microfilariae, released four proteins that have not previously been evaluated as vaccine candidates: a predicted 28.5 kDa filaria-specific protein, a zonadhesin and SCO-spondin-like protein, a vitellogenin, and a protein containing six metridin-like ShK toxin domains. Female nematodes also released two proteins derived from the obligate Wolbachia symbiont. Notably, excretory-secretory products from all parasite stages contained several uncharacterized members of the transthyretin-like protein family. Furthermore, biotin labeling revealed that redox proteins and enzymes involved in purinergic signaling were enriched on the adult nematode cuticle. Comparison of the L. sigmodontis adult secretome with that of the human-infective filarial nematode Brugia malayi (reported previously in three independent published studies) identified differences that suggest a considerable underlying diversity of potential immunomodulators. The molecules identified in L. sigmodontis excretory-secretory products show promise not only for vaccination against filarial infections, but for the amelioration of allergy and autoimmune diseases. PMID:24958169

Small RNAs and extracellular vesicles in filarial nematodes: From nematode development to diagnostics.

PubMed

Quintana, J F; Babayan, S A; Buck, A H

2017-02-01

Parasitic nematodes have evolved sophisticated mechanisms to communicate with their hosts in order to survive and successfully establish an infection. The transfer of RNA within extracellular vesicles (EVs) has recently been described as a mechanism that could contribute to this communication in filarial nematodes. It has been shown that these EVs are loaded with several types of RNAs, including microRNAs, leading to the hypothesis that parasites could actively use these molecules to manipulate host gene expression and to the exciting prospect that these pathways could result in new diagnostic and therapeutic strategies. Here, we review the literature on the diverse RNAi pathways that operate in nematodes and more specifically our current knowledge of extracellular RNA (exRNA) and EVs derived from filarial nematodes in vitro and within their hosts. We further detail some of the issues and questions related to the capacity of RNA-mediated communication to function in parasite-host interactions and the ability of exRNA to enable us to distinguish and detect different nematode parasites in their hosts. © 2016 The Authors. Parasite Immunology published by John Wiley & Sons Ltd.

Recombinant antigen-based antibody assays for the diagnosis and surveillance of lymphatic filariasis – a multicenter trial

PubMed Central

Lammie, Patrick J; Weil, Gary; Noordin, Rahmah; Kaliraj, Perumal; Steel, Cathy; Goodman, David; Lakshmikanthan, Vijaya B; Ottesen, Eric

2004-01-01

The development of antifilarial antibody responses is a characteristic feature of infection with filarial parasites. It should be possible to exploit this fact to develop tools to monitor the progress of the global program to eliminate lymphatic filariasis (LF); however, assays based on parasite extracts suffer from a number of limitations, including the paucity of parasite material, the difficulty of assay standardization and problems with assay specificity. In principle, assays based on recombinant filarial antigens should address these limitations and provide useful tools for diagnosis and surveillance of LF. The present multicenter study was designed to compare the performance of antibody assays for filariasis based on recombinant antigens Bm14, WbSXP, and BmR1. Coded serum specimens were distributed to five participating laboratories where assays for each antigen were conducted in parallel. Assays based on Bm14, WbSXP, or BmR1 demonstrated good sensitivity (>90%) for field use and none of the assays demonstrated reactivity with specimens from persons with non-filarial helminth infections. Limitations of the assays are discussed. Well-designed field studies are now needed to assess sampling methodology and the application of antibody testing to the monitoring and surveillance of LF elimination programs. PMID:15347425

Male Mating Competitiveness of a Wolbachia-Introgressed Aedes polynesiensis Strain under Semi-Field Conditions

PubMed Central

Bossin, Hervé; Dobson, Stephen L.

2011-01-01

Background Lymphatic filariasis (LF), a global public health problem affecting approximately 120 million people worldwide, is a leading cause of disability in the developing world including the South Pacific. Despite decades of ongoing mass drug administration (MDA) in the region, some island nations have not yet achieved the threshold levels of microfilaremia established by the World Health Organization for eliminating transmission. Previously, the generation of a novel Aedes polynesiensis strain (CP) infected with an exogenous type of Wolbachia has been described. The CP mosquito is cytoplasmically incompatible (i.e., effectively sterile) when mated with wildtype mosquitoes, and a strategy was proposed for the control of A. polynesiensis populations by repeated, inundative releases of CP males to disrupt fertility of wild females. Such a strategy could lead to suppression of the vector population and subsequently lead to a reduction in the transmission of filarial worms. Methodology/Principal Findings CP males and F1 male offspring from wild-caught A. polynesiensis females exhibit near equal mating competitiveness with F1 females under semi-field conditions. Conclusions/Significance While laboratory experiments are important, prior projects have demonstrated the need for additional testing under semi-field conditions in order to recognize problems before field implementation. The results reported here from semi-field experiments encourage forward progression toward small-scale field releases. PMID:21829750

[Mosquitoes as vectors for exotic pathogens in Germany].

PubMed

Becker, N; Krüger, A; Kuhn, C; Plenge-Bönig, A; Thomas, S M; Schmidt-Chanasit, J; Tannich, E

2014-05-01

As a result of intensified globalization of international trade and of substantial travel activities, mosquito-borne exotic pathogens are becoming an increasing threat for Europe. In Germany some 50 different mosquito species are known, several of which have vector competence for pathogens. During the last few years a number of zoonotic arboviruses that are pathogenic for humans have been isolated from mosquitoes in Germany including Usutu, Sindbis and Batai viruses. In addition, filarial worms, such as Dirofilaria repens have been repeatedly detected in mosquitoes from the federal state of Brandenburg. Other pathogens, in particular West Nile virus, are expected to emerge sooner or later in Germany as the virus is already circulating in neighboring countries, e.g. France, Austria and the Czech Republic. In upcoming years the risk for arbovirus transmission might increase in Germany due to increased occurrence of new so-called "invasive" mosquito species, such as the Asian bush mosquito Ochlerotatus japonicus or the Asian tiger mosquito Aedes albopictus. These invasive species are characterized by high vector competence for a broad range of pathogens and a preference for human blood meals. For risk assessment, a number of mosquito and pathogen surveillance projects have been initiated in Germany during the last few years; however, mosquito control strategies and plans of action have to be developed and put into place to allow early and efficient action against possible vector-borne epidemics.

Ocular onchocerciasis: current management and future prospects

PubMed Central

Babalola, Olufemi Emmanuel

2011-01-01

This paper reviews the current management of onchocerciasis and its future prospects. Onchocerciasis is a disease affecting millions of people in Africa, South and Central America, and Yemen. It is spread by the blackfly as a vector and caused by the filarial nematode, Onchocerca volvulus. A serious attempt was made by the Onchocerciasis Control Program between 1975 and 2002 to eliminate the vector in eleven of the endemic countries in West Africa, and with remarkable success. Formerly, the treatment was with diethyl carbamazine for the microfilaria and suramin for the adult worm. These drugs are now known to be toxic and unsuitable for mass distribution. In particular, they precipitate optic nerve disease. With the discovery of ivermectin, a much safer microfilaricide, and the decision of Merck to distribute the drug free of charge for as long as needed, the strategy of control switched to mass drug administration through community-directed treatment with ivermectin. So far, millions have received this annual or biannual treatment through the African Program for Onchocerciasis Control and the Onchocerciasis Elimination Program for the Americas. However, the problem with ivermectin is that it is a monotherapy microfilaricide which has limited effect on the adult worm, and thus will need to be continued for the life span of the adult worm, which may last up to 15 years. There are also early reports of resistance. Serious encephalopathy and death may occur when ivermectin is used in subjects heavily infested with loiasis. It seems unlikely that a break in transmission will occur with community-directed treatment with ivermectin in Africa because of population migrations and the highly efficient vector, but in the Americas some countries such as Columbia and the Oaxaca focus in Mexico have reported eradication. Vector control is only now applicable in selected situations, and particularly to control the nuisance value of the blackfly. Trials are ongoing for alternatives to ivermectin. Candidate drugs include moxidectin, a macrofilaricide, doxycycline which targets the Wolbachia endosymbiont, and flubendazole, which shows promise with the newer oral cyclodextrin formulation. PMID:22069350

Comparative bioinformatics, temporal and spatial expression analyses of Ixodes scapularis organic anion transporting polypeptides

PubMed Central

Radulović, Željko; Porter, Lindsay M.; Kim, Tae K.; Mulenga, Albert

2015-01-01

Organic anion-transporting polypeptides (Oatps) are an integral part of the detoxification mechanism in vertebrates and invertebrates. These cell surface proteins are involved in mediating the sodium-independent uptake and/or distribution of a broad array of organic amphipathic compounds and xenobiotic drugs. This study describes bioinformatics and biological characterization of 9 Oatp sequences in the Ixodes scapularis genome. These sequences have been annotated on the basis of 12 transmembrane domains, consensus motif D-X-RW-(I,V)-GAWW-X-G-(F,L)-L, and 11 conserved cysteine amino acid residues in the large extracellular loop 5 that characterize the Oatp superfamily. Ixodes scapularis Oatps may regulate non-redundant cross-tick species conserved functions in that they did not cluster as a monolithic group on the phylogeny tree and that they have orthologs in other ticks. Phylogeny clustering patterns also suggest that some tick Oatp sequences transport substrates that are similar to those of body louse, mosquito, eye worm, and filarial worm Oatps. Semi-quantitative RT-PCR analysis demonstrated that all 9 I. scapularis Oatp sequences were expressed during tick feeding. Ixodes scapularis Oatp genes potentially regulate functions during early and/or late-stage tick feeding as revealed by normalized mRNA profiles. Normalized transcript abundance indicates that I. scapularis Oatp genes are strongly expressed in unfed ticks during the first 24 h of feeding and/or at the end of the tick feeding process. Except for 2 I. scapularis Oatps, which were expressed in the salivary glands and ovaries, all other genes were expressed in all tested organs, suggesting the significance of I. scapularis Oatps in maintaining tick homeostasis. Different I. scapularis Oatp mRNA expression patterns were detected and discussed with reference to different physiological states of unfed and feeding ticks. PMID:24582512

Coincident filarial, intestinal helminth, and mycobacterial infection: helminths fail to influence tuberculin reactivity, but BCG influences hookworm prevalence.

PubMed

Lipner, Ettie M; Gopi, P G; Subramani, R; Kolappan, C; Sadacharam, K; Kumaran, Paul; Prevots, D Rebecca; Narayanan, P R; Nutman, Thomas B; Kumaraswami, V

2006-05-01

The prevalence of helminth and tuberculosis infections is high in South India, whereas Bacille-Calmette-Guerin (BCG) vaccine efficacy is low. Our aim was to determine whether concurrent helminth infection alters the ability to mount a delayed-type hypersensitivity response to tuberculin. In a cross-sectional study in southern India, individuals 6-65 years of age were screened for intestinal helminths, circulating filarial antigenemia, tuberculin reactivity, active tuberculosis, and history of BCG vaccination; 54% were purified protein derivative (PPD) positive, 32% had intestinal helminth infection, 9% were circulating filarial antigen positive, and 0.5% had culture-confirmed active tuberculosis. Only age and BCG vaccination were significantly associated with PPD reactivity; however, BCG vaccination was associated with a lower prevalence of hookworm infection relative to those without prior BCG vaccination. Neither intestinal helminth infection nor filarial infection was associated with diminished frequencies of PPD positivity. Our findings suggest that preceding helminth infection does not influence significantly the delayed-type hypersensitivity response to tuberculin.

[A case report: elephantiasis].

PubMed

Karagöz, Ergenekon; Karaahmetoğlu, Gökhan; Acar, Ali; Turhan, Vedat; Oncül, Oral; Görenek, Levent

2012-01-01

Klippel-Trenaunay syndrome (KTS) is a rare disease and a syndrome that is characterized by the triad of congenital port wine stains,venous malformations with or without varicose veins, bone or soft tissue hypertrophy. Lymphatic filariasis is a filarial disease which usually occurs with genital anomalies, pathologies associated with lymphedema or elephantiasis caused by a filarial infectious agent. In this case report, a 20-year-old male patient admitted to our clinic for diagnosis and treatment with right leg edema and lesions compatible with dermatological manifestations. In the list of differential diagnosis, filarial elephantiasis was also thought, consequently KTS was diagnosed. (Turkiye Parazitol Derg 2012; 36: 188-90).

Helminth antigens selectively differentiate unsensitized CD45RA+ CD4+ human T cells in vitro.

PubMed

Steel, C; Nutman, T B

1998-01-01

Human filarial helminth infections are characterized by type 2 immune responses to parasite Ag that can persist for the life of the individual; one possible cause for this may be prenatal exposure to the blood-borne microfilarial (Mf) stage of the parasite. To examine the relationship between early exposure to filarial Ag and subsequent immune responsiveness, CD45RA+ CD4+ cells frp, normal unsensitized donors were stimulated in vitro with soluble microfilarial Ag (MfAg) from the filarial parasite Brugia malayi in the presence of APCs. MfAg alone induced proliferation and IFN-gamma and IL-5 production in unsensitized CD45RA+ CD4+ cells, demonstrating the ability of filarial Ags to prime naive T cells in the absence of exogenous cytokines and dendritic cells. Adding exogenous cytokine(s) (particularly IL-12 and IL-4) during priming was able to alter the MfAg-specific responses of CD45RA+ CD4+ cells as well as subsequent responses to Ag. Interestingly, priming solely with MfAg led to enhanced IL-5 production following Ag restimulation, suggesting that MfAg preferentially primes for type 2 responses. These data demonstrate that filarial Ags by themselves can specifically prime CD45RA+ CD4+ cells in vitro and do so in such a way as to deviate the immune response.

Seroconversion to filarial antigens in Australian defence force personnel in Timor-Leste.

PubMed

Frances, Stephen P; Baade, Lisa M; Kubofcik, Joseph; Nutman, Thomas B; Melrose, Wayne D; McCarthy, James S; Nissen, Michael D

2008-04-01

To investigate whether Australian soldiers were exposed to filarial parasites that cause lymphatic filariasis during a 6-month deployment to Timor-Leste, antifilarial antibody levels were measured in 907 soldiers using an enzyme linked immunosorbent assay (ELISA). Initial testing using Dirofilaria immitis antigen demonstrated that 49 of 907 (5.4%) soldiers developed antifilarial antibodies of the IgG1 subclass after deployment, whereas 1 of 944 (0.1%) seroconverted to the IgG4 subclass. When a sub sample of 88 D. immitis-reactive sera was subject to testing with an antifilarial antibody test using Brugia malayi antigen, 46 had elevated IgG antibodies, whereas 5 had elevated antibodies of the IgG4 subclass. A total of 24 soldiers seroconverted to B. malayi, as measured by parasite-specific IgG, whereas 1 seroconverted to IgG4. The relatively low number of seroconversions indicates a low but measurable risk of exposure to human filarial parasites among Australian soldiers deployed to Timor-Leste. However, to reduce the risk of exposure to these parasites, soldiers deploying to endemic areas should practice strict adherence to personal protective measures against mosquito bites.

The essential oil of Zingiber officinalis Linn (Zingiberaceae) as a mosquito larvicidal and repellent agent against the filarial vector Culex quinquefasciatus Say (Diptera: Culicidae).

PubMed

Pushpanathan, Thambusamy; Jebanesan, Arulsamy; Govindarajan, Marimuthu

2008-05-01

Essential oils extracted by steam distillation from Zingiber officinalis was evaluated for larvicidal and repellent activity against the filarial mosquito Culex quinquefasciatus. The larval mortality was observed after 24 h treated for late third instar. The LC50 value was 50.78 ppm. Skin repellent test at 1.0, 2.0, 3.0, and 4.0 mg/cm2 concentration of Z. officinalis gave 100% protection up to 15, 30, 60, and 120 min. These results clearly reveal that the essential oil of Z. officinalis served as a potential larvicidal and repellent agent against filarial vector C. quinquefasciatus.

Is there a risk of filarial infection during long-term missions in Haiti?

PubMed

Weitzel, Thomas; Rosas, Reinaldo; Fica, Alberto; Dabanch, Jeannette; Polanco, Myriam; Egaña, Alicia; Triantafilo, Vjera; Pfarr, Kenneth; Hoerauf, Achim; Reiter-Owona, Ingrid

2016-01-01

Haiti has the highest prevalence of lymphatic filariasis (Wuchereria bancrofti) in the Western Hemisphere. Still, the risk of filarial infection for long-term visitors such as humanitarian aid workers or military personnel is uncertain. The presented study analyzed the exposure to W. bancrofti in Chilean participants of the UN Stabilization Mission in Haiti (MINUSTAH) in 2011. Blood samples collected from 531 participants were screened for antifilarial antibodies by IgG ELISA, and, if positive, analyzed by immunofluorescence assay (IFA), IgG4 ELISA, Real-Time PCR, and circulating filarial antigen (CFA) card test. ELISA screening was positive in 10 cases. Seroconversion occurred in only two cases (0.38%) based on ELISA values determined in samples taken before and after deployment. Positive IgG ELISA values could not be confirmed by IFA and IgG4 ELISA. Real-Time PCR and CFA testing did not reveal the presence of filaria. Our data indicate that in the examined cohort of MINUSTAH participants in 2011, the risk of filarial exposure or infection was low. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of calcium channel blockers on the contractility of the filariid Acanthocheilonema viteae.

PubMed

Christ, D; Stillson, T

1992-01-01

The role of calcium in muscle contractility was explored in the filarial nematode Acanthocheilonema viteae (Dipetalonema viteae). The parasite was slit open longitudinally and mounted in a smooth-muscle chamber that had been filled with aerated (95% N2/5% CO2) physiological solution at 37 degrees C. Nifedipine (10(-6) M) and cadmium (3 x 10(-5) M) reduced the spontaneous isotonic contractions of A. viteae, whereas verapamil (10(-5) M) and diltiazem (10(-5) M) enhanced them. The effects of nifedipine and verapamil did not appear to be due to the solvent ethanol. All of the drugs reduced the maximal contraction induced by acetylcholine (ACh, 10(-5) M), although nifedipine was the most potent. After the exposure of worm preparations to a calcium-free medium containing ethyleneglycol-bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA, 10(-4) M) for 1 h, application of ACh (10(-5) M) induced a small, transient contraction. Subsequent applications of ACh in this medium had no effect. Thus, the nematode muscle contraction appears to depend on extracellular calcium. Nifedipine, diltiazem, and verapamil could act by reducing the calcium influx across the muscle membrane.

Molecular evidence on the occurrence of co-infection with Pichia guilliermondii and Wuchereria bancrofti in two filarial endemic districts of India

PubMed Central

2014-01-01

Background Lymphatic filariasis (LF), a vector-borne parasitic disease, is endemic in several parts of India and mostly affects the poor or those with a low-income. The disease results in huge numbers of morbidities, disabilities, and deaths every year. Association of co-infection with other pathogens makes the condition more severe. Although co-infection is becoming a growing area of research, it is yet to emerge as a frontier research topic in filarial research specifically. This study reports the occurrence of a fungal infection in a large number of patients suffering from bancroftian filariasis in two districts of West Bengal, India. Methods Nocturnal blood samples from filarial patients containing parasites and fungus were initially co-cultured, and further the fungus was isolated and characterized. Molecular identification of the isolate was carried out by PCR-based selective amplification and sequencing of highly-conserved D1/D2 region of 26S rDNA, whereas pathogenicity was determined by amplification of the RPS0 gene. A phylogenetic tree was constructed to study the relationship between the isolate and common pathogenic yeasts. The isolate was studied for antibiotic sensitivity, whereas morphological characterization was performed by microscopic techniques. Results The isolate was identified as Pichia guilliermondii and this fungus was found to exist in co-infection with Wuchereria bancrofti in filarial patients. The fungus showed resistance to azole antifungals, griseofulvin, and, amphotericin B, whereas significant susceptibility was evident in cases of nystatin and cycloheximide. A total of 197 out of 222 patients showed this co-infection. Conclusion This study revealed, for the first time, that P. guilliermondii exists as a co-infection in microfilaraemic individuals living in a filarial endemic zone. The findings are important and have relevance to human health, especially for filarial patients. PMID:24708881

Mapping the distribution of Loa loa in Cameroon in support of the African Programme for Onchocerciasis Control

PubMed Central

Thomson, Madeleine C; Obsomer, Valérie; Kamgno, Joseph; Gardon, Jacques; Wanji, Samuel; Takougang, Innocent; Enyong, Peter; Remme, Jan H; Molyneux, David H; Boussinesq, Michel

2004-01-01

Background Loa loa has recently emerged as a filarial worm of significant public health importance as a consequence of its impact on the African Programme for Onchocerciasis Control (APOC). Severe, sometimes fatal, encephalopathic reactions to ivermectin (the drug of choice for onchocerciasis control) have occurred in some individuals with high Loa loa microfilarial counts. Since high density of Loa loa microfilariae is known to be associated with high prevalence rates, a distribution map of the latter may determine areas where severe reactions might occur. The aim of the study was to identify variables which were significantly associated with the presence of a Loa microfilaraemia in the subjects examined, and to develop a spatial model predicting the prevalence of the Loa microfilaraemia. Methods Epidemiological data were collected from 14,225 individuals living in 94 villages in Cameroon, and analysed in conjunction with environmental data. A series of logistic regression models (multivariate analysis) was developed to describe variation in the prevalence of Loa loa microfilaraemia using individual level co-variates (age, sex, μl of blood taken for examination) and village level environmental co-variates (including altitude and satellite-derived vegetation indices). Results A spatial model of Loa loa prevalence was created within a geographical information system. The model was then validated using an independent data set on Loa loa distribution. When considering both data sets as a whole, and a prevalence threshold of 20%, the sensitivity and the specificity of the model were 81.7 and 69.4%, respectively. Conclusions The model developed has proven very useful in defining the areas at risk of post-ivermectin Loa-related severe adverse events. It is now routinely used by APOC when projects of community-directed treatment with ivermectin are examined. PMID:15298709

Mapping the distribution of Loa loa in Cameroon in support of the African Programme for Onchocerciasis Control.

PubMed

Thomson, Madeleine C; Obsomer, Valérie; Kamgno, Joseph; Gardon, Jacques; Wanji, Samuel; Takougang, Innocent; Enyong, Peter; Remme, Jan H; Molyneux, David H; Boussinesq, Michel

2004-08-06

BACKGROUND: Loa loa has recently emerged as a filarial worm of significant public health importance as a consequence of its impact on the African Programme for Onchocerciasis Control (APOC). Severe, sometimes fatal, encephalopathic reactions to ivermectin (the drug of choice for onchocerciasis control) have occurred in some individuals with high Loa loa microfilarial counts. Since high density of Loa loa microfilariae is known to be associated with high prevalence rates, a distribution map of the latter may determine areas where severe reactions might occur. The aim of the study was to identify variables which were significantly associated with the presence of a Loa microfilaraemia in the subjects examined, and to develop a spatial model predicting the prevalence of the Loa microfilaraemia. METHODS: Epidemiological data were collected from 14,225 individuals living in 94 villages in Cameroon, and analysed in conjunction with environmental data. A series of logistic regression models (multivariate analysis) was developed to describe variation in the prevalence of Loa loa microfilaraemia using individual level co-variates (age, sex, microl of blood taken for examination) and village level environmental co-variates (including altitude and satellite-derived vegetation indices). RESULTS: A spatial model of Loa loa prevalence was created within a geographical information system. The model was then validated using an independent data set on Loa loa distribution. When considering both data sets as a whole, and a prevalence threshold of 20%, the sensitivity and the specificity of the model were 81.7 and 69.4%, respectively. CONCLUSIONS: The model developed has proven very useful in defining the areas at risk of post-ivermectin Loa-related severe adverse events. It is now routinely used by APOC when projects of community-directed treatment with ivermectin are examined.

Detection of Dirofilaria immitis and other arthropod-borne filarioids by an HRM real-time qPCR, blood-concentrating techniques and a serological assay in dogs from Costa Rica.

PubMed

Rojas, Alicia; Rojas, Diana; Montenegro, Víctor M; Baneth, Gad

2015-03-23

Canine filarioids are important nematodes transmitted to dogs by arthropods. Diagnosis of canine filariosis is accomplished by the microscopic identification of microfilariae, serology or PCR for filarial-DNA. The aim of this study was to evaluate a molecular assay for the detection of canine filariae in dog blood, to compare its performance to other diagnostic techniques, and to determine the relationship between microfilarial concentration and infection with other vector-borne pathogens. Blood samples from 146 dogs from Costa Rica were subjected to the detection of canine filarioids by four different methods: the microhematocrit tube test (MCT), Knott's modified test, serology and a high resolution melt and quantitative real-time PCR (HRM-qPCR). Co-infection with other vector-borne pathogens was also evaluated. Fifteen percent of the dogs were positive to Dirofilaria immitis by at least one of the methods. The HRM-qPCR produced distinctive melting plots for the different filarial worms and revealed that 11.6% of dogs were infected with Acanthocheilonema reconditum. The latter assay had a limit of detection of 2.4x10⁻⁴ mf/μl and detected infections with lower microfilarial concentrations in comparison to the microscopic techniques and the serological assay. The MCT and Knott's test only detected dogs with D. immitis microfilaremias above 0.7 mf/μl. Nevertheless, there was a strong correlation between the microfilarial concentration obtained by the Knott's modified test and the HRM-qPCR (r = 0.906, p < 0.0001). Interestingly, one dog was found infected with Cercopithifilaria bainae infection. Moreover, no association was found between microfilaremia and co-infection and there was no significant difference in microfilarial concentration between dogs infected only with D. immitis and dogs co-infected with Ehrlichia canis, Anaplasma platys or Babesia vogeli. This is the first report of A. reconditum and C. bainae in Costa Rica and Central America. Among the evaluated diagnostic techniques, the HRM-qPCR showed the most sensitive and reliable performance in the detection of blood filaroids in comparison to the Knott's modified test, the MCT test and a serological assay.

Lactate oxidation coupled to energy production in mitochondria like particles from Setaria digitata, a filarial parasite.

PubMed

Sivan, V M; Raj, R K

1994-10-14

In the filarial parasite, Setaria digitata, the mitochondria like particles (MLP) show NAD reduction with sodium lactate. The MLP also reduces dye and ferricyanide with lactate. The ferricyanide reduction by lactate is found to be sensitive to the cytochrome o inhibitor orthohydroxy diphenyl (OHD) and complex I inhibitor rotenone, modulated by ADP (+) and ATP (-) and inhibited by pyruvate and oxaloacetate. MLP shows lactate oxidation sensitive to OHD, rotenone and sodium malonate. Thus, the lactate utilizing complex system, consisting of an NADH generating MLP bound lactate dehydrogenase and a lactate flavocytochrome reductase tightly linked to complex I and cytochrome o, produces ATP in functional association with fumarate reductase complex and other enzyme systems. Hence, this study provides new dimensions to the study of metabolism in filarial parasites.

Comparison of Doxycycline, Minocycline, Doxycycline plus Albendazole and Albendazole Alone in Their Efficacy against Onchocerciasis in a Randomized, Open-Label, Pilot Trial

PubMed Central

Batsa, Linda; Ayisi-Boateng, Nana Kwame; Osei-Mensah, Jubin; Mubarik, Yusif; Konadu, Peter; Ricchiuto, Arcangelo; Fimmers, Rolf; Arriens, Sandra; Dubben, Bettina; Ford, Louise; Taylor, Mark; Hoerauf, Achim

2017-01-01

The search for new macrofilaricidal drugs against onchocerciasis that can be administered in shorter regimens than required for doxycycline (DOX, 200mg/d given for 4–6 weeks), identified minocycline (MIN) with superior efficacy to DOX. Further reduction in the treatment regimen may be achieved with co-administration with standard anti-filarial drugs. Therefore a randomized, open-label, pilot trial was carried out in an area in Ghana endemic for onchocerciasis, comprising 5 different regimens: the standard regimen DOX 200mg/d for 4 weeks (DOX 4w, N = 33), the experimental regimens MIN 200mg/d for 3 weeks (MIN 3w; N = 30), DOX 200mg/d for 3 weeks plus albendazole (ALB) 800mg/d for 3 days (DOX 3w + ALB 3d, N = 32), DOX 200mg/d for 3 weeks (DOX 3w, N = 31) and ALB 800mg for 3 days (ALB 3d, N = 30). Out of 158 randomized participants, 116 (74.4%) were present for the follow-up at 6 months of whom 99 participants (63.5%) followed the treatment per protocol and underwent surgery. Histological analysis of the adult worms in the extirpated nodules revealed absence of Wolbachia in 98.8% (DOX 4w), 81.4% (DOX 3w + ALB 3d), 72.7% (MIN 3w), 64.1% (DOX 3w) and 35.2% (ALB 3d) of the female worms. All 4 treatment regimens showed superiority to ALB 3d (p < 0.001, p < 0.001, p = 0.002, p = 0.008, respectively), which was confirmed by real-time PCR. Additionally, DOX 4w showed superiority to all other treatment arms. Furthermore DOX 4w and DOX 3w + ALB 3d showed a higher amount of female worms with degenerated embryogenesis compared to ALB 3d (p = 0.028, p = 0.042, respectively). These results confirm earlier studies that DOX 4w is sufficient for Wolbachia depletion and the desired parasitological effects. The data further suggest that there is an additive effect of ALB (3 days) on top of that of DOX alone, and that MIN shows a trend for stronger potency than DOX. These latter two results are preliminary and need confirmation in a fully randomized controlled phase 2 trial. Trial Registration: ClinicalTrials.gov #06010453 PMID:28056021

The burden of non-filarial elephantiasis in Ethiopia.

PubMed

Animut, Abebe

2007-12-01

Although known for many years, non-filarial elephantiasis remains a public health problem in tropical Africa, including the farming community of Ethiopia. The problem may be exacerbated in women who shoulder most of the burden of agricultural labour in the countryside. The intention of this brief review is to emphasise the burden of the disease and to alert researchers and organisations concerned with health care and prevention.

Filariasis in Travelers Presenting to the GeoSentinel Surveillance Network

PubMed Central

Lipner, Ettie M.; Law, Melissa A.; Barnett, Elizabeth; Keystone, Jay S.; von Sonnenburg, Frank; Loutan, Louis; Prevots, D. Rebecca; Klion, Amy D.; Nutman, Thomas B.

2007-01-01

Background As international travel increases, there is rising exposure to many pathogens not traditionally encountered in the resource-rich countries of the world. Filarial infections, a great problem throughout the tropics and subtropics, are relatively rare among travelers even to filaria-endemic regions of the world. The GeoSentinel Surveillance Network, a global network of medicine/travel clinics, was established in 1995 to detect morbidity trends among travelers. Principal Findings We examined data from the GeoSentinel database to determine demographic and travel characteristics associated with filaria acquisition and to understand the differences in clinical presentation between nonendemic visitors and those born in filaria-endemic regions of the world. Filarial infections comprised 0.62% (n = 271) of all medical conditions reported to the GeoSentinel Network from travelers; 37% of patients were diagnosed with Onchocerca volvulus, 25% were infected with Loa loa, and another 25% were diagnosed with Wuchereria bancrofti. Most infections were reported from immigrants and from those immigrants returning to their county of origin (those visiting friends and relatives); the majority of filarial infections were acquired in sub-Saharan Africa. Among the patients who were natives of filaria-nonendemic regions, 70.6% acquired their filarial infection with exposure greater than 1 month. Moreover, nonendemic visitors to filaria-endemic regions were more likely to present to GeoSentinel sites with clinically symptomatic conditions compared with those who had lifelong exposure. Significance Codifying the filarial infections presenting to the GeoSentinel Surveillance Network has provided insights into the clinical differences seen among filaria-infected expatriates and those from endemic regions and demonstrated that O. volvulus infection can be acquired with short-term travel. PMID:18160987

Data base management system for lymphatic filariasis--a neglected tropical disease.

PubMed

Upadhyayula, Suryanaryana Murty; Mutheneni, Srinivasa Rao; Kadiri, Madhusudhan Rao; Kumaraswamy, Sriram; Nelaturu, Sarat Chandra Babu

2012-01-01

Researchers working in the area of Public Health are being confronted with large volumes of data on various aspects of entomology and epidemiology. To obtain the relevant information out of these data requires particular database management system. In this paper, we have described about the usages of our developed database on lymphatic filariasis. This database application is developed using Model View Controller (MVC) architecture, with MySQL as database and a web based interface. We have collected and incorporated the data on filariasis in the database from Karimnagar, Chittoor, East and West Godavari districts of Andhra Pradesh, India. The importance of this database is to store the collected data, retrieve the information and produce various combinational reports on filarial aspects which in turn will help the public health officials to understand the burden of disease in a particular locality. This information is likely to have an imperative role on decision making for effective control of filarial disease and integrated vector management operations.

The genome of Onchocerca volvulus, agent of river blindness

PubMed Central

Cotton, James A.; Bennuru, Sasisekhar; Grote, Alexandra; Harsha, Bhavana; Tracey, Alan; Beech, Robin; Doyle, Stephen R.; Dunn, Matthew; Dunning Hotopp, Julie C.; Holroyd, Nancy; Kikuchi, Taisei; Lambert, Olivia; Mhashilkar, Amruta; Mutowo, Prudence; Nursimulu, Nirvana; Ribeiro, Jose M. C.; Rogers, Matthew B.; Stanley, Eleanor; Swapna, Lakshmipuram S.; Tsai, Isheng J.; Unnasch, Thomas R.; Voronin, Denis; Parkinson, John; Nutman, Thomas B.; Ghedin, Elodie; Berriman, Matthew; Lustigman, Sara

2017-01-01

Human onchocerciasis is a serious neglected tropical disease caused by the filarial nematode Onchocerca volvulus that can lead to blindness and chronic disability. Control of the disease relies largely on mass administration of a single drug, and the development of new drugs and vaccines depends on a better knowledge of parasite biology. Here, we describe the chromosomes of O. volvulus and its Wolbachia endosymbiont. We provide the highest-quality sequence assembly for any parasitic nematode to date, giving a glimpse into the evolution of filarial parasite chromosomes and proteomes. This resource was used to investigate gene families with key functions that could be potentially exploited as targets for future drugs. Using metabolic reconstruction of the nematode and its endosymbiont, we identified enzymes that are likely to be essential for O. volvulus viability. In addition, we have generated a list of proteins that could be targeted by Federal-Drug-Agency-approved but repurposed drugs, providing starting points for anti-onchocerciasis drug development. PMID:27869790

Inheritance of mercury tolerance in the aquatic oligochaete Tubifex tubifex.

PubMed

Vidal, Dora Elva; Horne, Alex John

2003-09-01

Resistance to contaminants is an important yet unmeasured factor in sediment toxicity tests. The rate at which mercury resistance develops and its genetic persistence in the oligochaete worm Tubifex tubifex were studied under laboratory conditions. Worms were raised for four generations under two different sediment treatments, one reference clean sediment, the other contaminated with mercury. Worms raised in mercury-contaminated sediment developed mercury tolerance that persisted even when the worms were raised for three subsequent generations in clean sediment. Mercury tolerance was determined by comparative water-only toxicity tests with mercury as the only stressor. Control worms had a mean lethal concentration (LC50) of 0.18 mg/L(-1). Worms exposed to high levels of mercury in sediment had high mercury tolerance with a mean LC50 of 1.40 mg/L(-1). When mercury-tolerant and control mercury-intolerant worms were crossed, their descendants also demonstrated mercury tolerance during lethal toxicity tests. The LC50 for worm descendants resulting from this cross was 1.39 mg/L(-1). Adaptation to mercury exposures occurred rapidly in this group of worms and appears to be due to both phenotypic and genotypic mechanisms. Development of contaminant resistance and adaptation may be common phenomena in aquatic benthic invertebrates, which should be considered during the design and interpretation of toxicity tests.

Parasitological, serological and clinical evidence for high prevalence of podoconiosis (non-filarial elephantiasis) in Midakegn district, central Ethiopia.

PubMed

Geshere Oli, Geleta; Tekola Ayele, Fasil; Petros, Beyene

2012-06-01

To determine whether the elephantiasis in Midakegn district, central Ethiopia, is filarial or non-filarial (podoconiosis) using serological, parasitological and clinical examinations, and to estimate its prevalence. At house-to-house visits in 330 randomly selected households, all household members who had elephantiasis were interviewed and clinically examined at the nearby health centre to confirm the presence of elephantiasis, check the presence of scrotal swelling and rule out the other causes of lymphoedema. A midnight blood sample was obtained from each participant with elephantiasis for microscopic examination of Wuchereria bancrofti microfilaria. A daytime blood sample was obtained from half of the participants for serological confirmation using the immuno-chromatographic test card. Consistent with the features of podoconiosis, none of the elephantiasis cases had consistently worn shoes since childhood; 94.3% had bilateral swelling limited below the level of the knees; no individual had thigh or scrotal elephantiasis; parasitological test for microfilariae and serological tests for W. bancrofti antigen were negative in all samples. The prevalence of the disease was 7.4% and it peaked in the third decade of life, the most economically active age. Midakegn District has a high prevalence of podoconiosis and no filarial elephantiasis. Prevention, treatment and control of podoconiosis must be among the top priorities of public health programmes. © 2012 Blackwell Publishing Ltd.

The Effect of Macrocyclic Lactones-Ivermectin Exposure on Egg Hatching and Larval Development of Caenorhabditis elegans.

PubMed

Zain, Mariani Mohd; Yahaya, Zary Shariman; Him, Nik Ahmad Irwan Izzauddin Nik

2016-11-01

To date, the ivermectin resistance in nematode parasites has been reported and many studies are carried out to determine the causes of this problem. A free-living Caenorhabditis elegans is used as a model system for this study to investigate the response of C. elegans to ivermectin exposure by using larval development assay. Worms were exposed to ivermectin at concentration from 1 ng/mL to 10 ng/mL and dimethyl sulphoxide (DMSO) as a control. The developments of the worms were monitored for 24, 48, 72, and 96 hours until the worms become adults. Results indicated that worms' growth began to be affected by ivermectin at a concentration of 5 ng/mL, while at the concentration of 6, 7, 8, 9, and 10 ng/mL, the growth of worms were inhibited compared to control worms. Further study of the protein expression in C. elegans should be done to investigate the up-regulated and down-regulated proteins involve in ivermectin resistance.

Fluorescence hyperspectral imaging technique for foreign substance detection on fresh-cut lettuce.

PubMed

Mo, Changyeun; Kim, Giyoung; Kim, Moon S; Lim, Jongguk; Cho, Hyunjeong; Barnaby, Jinyoung Yang; Cho, Byoung-Kwan

2017-09-01

Non-destructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed to detect worms on fresh-cut lettuce. The optimal wavebands for detecting the worms were investigated using the one-way ANOVA and correlation analyses. The worm detection imaging algorithms, RSI-I (492-626)/492 , provided a prediction accuracy of 99.0%. The fluorescence HSI techniques indicated that the spectral images with a pixel size of 1 × 1 mm had the best classification accuracy for worms. The overall results demonstrate that fluorescence HSI techniques have the potential to detect worms on fresh-cut lettuce. In the future, we will focus on developing a multi-spectral imaging system to detect foreign substances such as worms, slugs and earthworms on fresh-cut lettuce. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

A comprehensive assessment of lymphatic filariasis in Sri Lanka six years after cessation of mass drug administration.

PubMed

Rao, Ramakrishna U; Nagodavithana, Kumara C; Samarasekera, Sandhya D; Wijegunawardana, Asha D; Premakumara, Welmillage D Y; Perera, Samudrika N; Settinayake, Sunil; Miller, J Phillip; Weil, Gary J

2014-01-01

The Sri Lankan Anti-Filariasis Campaign conducted 5 rounds of mass drug administration (MDA) with diethycarbamazine plus albendazole between 2002 and 2006. We now report results of a comprehensive surveillance program that assessed the lymphatic filariasis (LF) situation in Sri Lanka 6 years after cessation of MDA. Transmission assessment surveys (TAS) were performed per WHO guidelines in primary school children in 11 evaluation units (EUs) in all 8 formerly endemic districts. All EUs easily satisfied WHO criteria for stopping MDA. Comprehensive surveillance was performed in 19 Public Health Inspector (PHI) areas (subdistrict health administrative units). The surveillance package included cross-sectional community surveys for microfilaremia (Mf) and circulating filarial antigenemia (CFA), school surveys for CFA and anti-filarial antibodies, and collection of Culex mosquitoes with gravid traps for detection of filarial DNA (molecular xenomonitoring, MX). Provisional target rates for interruption of LF transmission were community CFA <2%, antibody in school children <2%, and filarial DNA in mosquitoes <0.25%. Community Mf and CFA prevalence rates ranged from 0-0.9% and 0-3.4%, respectively. Infection rates were significantly higher in males and lower in people who denied prior treatment. Antibody rates in school children exceeded 2% in 10 study sites; the area that had the highest community and school CFA rates also had the highest school antibody rate (6.9%). Filarial DNA rates in mosquitoes exceeded 0.25% in 10 PHI areas. Comprehensive surveillance is feasible for some national filariasis elimination programs. Low-level persistence of LF was present in all study sites; several sites failed to meet provisional endpoint criteria for LF elimination, and follow-up testing will be needed in these areas. TAS was not sensitive for detecting low-level persistence of filariasis in Sri Lanka. We recommend use of antibody and MX testing as tools to complement TAS for post-MDA surveillance.

Development and testing of a de novo clinical staging system for podoconiosis (endemic non-filarial elephantiasis).

PubMed

Tekola, Fasil; Ayele, Zewdu; Mariam, Dereje Haile; Fuller, Claire; Davey, Gail

2008-10-01

To develop and test a robust clinical staging system for podoconiosis, a geochemical disease in individuals exposed to red clay soil. We adapted the Dreyer system for staging filarial lymphoedema and tested it in four re-iterative field tests conducted in an area of high-podoconiosis prevalence in Southern Ethiopia. The system has five stages according to proximal spread of disease and presence of dermal nodules, ridges and bands. We measured the 1-week repeatability and the inter-observer agreement of the final staging system. The five-stage system is readily understood by community workers with little health training. Kappa for 1-week repeatability was 0.88 (95% CI 0.80-0.96), for agreement between health professionals was 0.71 (95% CI 0.60-0.82), while that between health professionals and community podoconiosis agents without formal health training averaged 0.64 (95% CI 0.52-0.78). This simple staging system with good inter-observer agreement and repeatability can assist in the management and further study of podoconiosis.

Eotaxin-1 is involved in parasite clearance during chronic filarial infection.

PubMed

Gentil, K; Lentz, C S; Rai, R; Muhsin, M; Kamath, A D; Mutluer, O; Specht, S; Hübner, M P; Hoerauf, A

2014-02-01

Eosinophil migration as key feature of helminth infection is increased during infection with filarial nematodes. In a mouse model of filariasis, we investigated the role of the eosinophil-attracting chemokine Eotaxin-1 on disease outcome. BALB/c and Eotaxin-1(-/-) mice were infected with the rodent filaria Litomosoides sigmodontis, and parasitic parameters, cellular migration to the site of infection, and cellular responsiveness were investigated. We found increased parasite survival but unaffected eosinophil migration to the site of infection in Eotaxin-1(-/-) mice. Expression of CD80 and CD86 was reduced on eosinophils from Eotaxin-1(-/-) mice after in vitro TLR2 stimulation and exposure to filarial antigen, respectively, suggesting a potential reduced activation state of eosinophils in Eotaxin-1 deficient mice. We further demonstrated that macrophages from Eotaxin-1(-/-) mice produce decreased amounts of IL-6 in vitro, a cytokine found to be associated with parasite containment, suggesting possible mechanisms by which Eotaxin-1 regulates activation of inflammatory cells and thus parasite survival. © 2013 John Wiley & Sons Ltd.

Laboratory and Field Evaluation of a New Rapid Test for Detecting Wuchereria bancrofti Antigen in Human Blood

PubMed Central

Weil, Gary J.; Curtis, Kurt C.; Fakoli, Lawrence; Fischer, Kerstin; Gankpala, Lincoln; Lammie, Patrick J.; Majewski, Andrew C.; Pelletreau, Sonia; Won, Kimberly Y.; Bolay, Fatorma K.; Fischer, Peter U.

2013-01-01

Global Program to Eliminate Lymphatic Filariasis (GPELF) guidelines call for using filarial antigen testing to identify endemic areas that require mass drug administration (MDA) and for post-MDA surveillance. We compared a new filarial antigen test (the Alere Filariasis Test Strip) with the reference BinaxNOW Filariasis card test that has been used by the GPELF for more than 10 years. Laboratory testing of 227 archived serum or plasma samples showed that the two tests had similar high rates of sensitivity and specificity and > 99% agreement. However, the test strip detected 26.5% more people with filarial antigenemia (124/503 versus 98/503) and had better test result stability than the card test in a field study conducted in a filariasis-endemic area in Liberia. Based on its increased sensitivity and other practical advantages, we believe that the test strip represents a major step forward that will be welcomed by the GPELF and the filariasis research community. PMID:23690552

Ancient horizontal transfers of retrotransposons between birds and ancestors of human pathogenic nematodes

PubMed Central

Suh, Alexander; Witt, Christopher C.; Menger, Juliana; Sadanandan, Keren R.; Podsiadlowski, Lars; Gerth, Michael; Weigert, Anne; McGuire, Jimmy A.; Mudge, Joann; Edwards, Scott V.; Rheindt, Frank E.

2016-01-01

Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83–99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25–22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20–17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity. PMID:27097561

Cytokine production in BALB/c mice immunized with radiation attenuated third stage larvae of the filarial nematode, Brugia pahangi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bancroft, A.J.; Devaney, E.; Grencis, R.K.

1993-02-15

BALB/c mice immunized with radiation-attenuated third stage larvae of the filarial nematode Brugia pahangi are strongly immune to challenge infection. Investigation of the profile of cytokines secreted by spleen cells from immune mice stimulated in vitro with either parasite Ag or with Con A revealed high levels of IL-5 and IL-9 and moderate levels of IL-4. In contrast, secretion of IFN-[gamma] by spleen cells from immune animals was negligible. Spleen cells from control mice secreted low levels of all cytokines assayed. Levels of parasite-specific IgE were significantly elevated in immune animals and a peripheral blood eosinophilia was observed, which exhibitedmore » a biphasic distribution. Our results are consistent with the preferential expansion of Th2 cells in immune animals and provide the basis for dissecting the means by which radiation-attenuated larvae of filarial nematodes stimulate immunity. 5l refs., 3 figs., 3 tabs.« less

Face Gear Drive with Spur Involute Pinion: Geometry, Generation by a Worm, Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Fuentes, Alfonso; Zanzi, Claudio; Pontiggia, Matteo; Handschuh, Robert F. (Technical Monitor)

2002-01-01

A face gear drive with a spur involute pinion is considered. The generation of the face gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. An analytical approach is proposed for the determination of: (1) the worm thread surface; (2) avoidance of singularities of the worm thread surface, (air) dressing of the worm; and (3) determination of stresses of the face-gear drive. A computer program for simulation of meshing and contact of the pinion and face-gear has been developed. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided.

[Ultrastructural basis of interactions between prokaryotes and eukaryotes in different symbiotic models].

PubMed

Sacchi, L

2004-06-01

This paper reviews the Author's contribution to the knowledge of the ultrastructural basis of the prokaryote-eukaryote interactions in different models assessed by an ultrastructural approach. In agreement with the hypothesis of the origin of eukaryotic cells, which are chimeras of several prokaryotes with different morpho-functional specializations, symbiosis had major consequence for evolution of life. In Arthropods, one of the most successful lifestyles, the presence of endosymbiotic prokaryotes, plays an important role in their metabolism. In some cases, genome integration has occurred in the endosymbiotic relationships with the host, proving that intracellular symbiosis is not merely a nutritional supplement. Intracellular symbiotic bacteria are also described in nematodes. In particular, the presence of intracellular Wolbachia in filariae, even if its function is not yet completely known, influences positively the reproductive biology and the survival of the host, as proved by antibiotic treatment against this bacterium. The ultrastructural images reported in this review were obtained using different species of cockroaches, termites, ticks and filarial nematodes. The traditional methods of transmission (TEM), scansion (SEM) and immuno electron microscopy were used. In addition, also freeze-fracture and deep-etching techniques were employed. The cockroaches and the primitive termite Mastotermes darwiniensis host symbiotic bacteria in the ovary and in specialized cells (bacteriocytes) of the fat body. These bacteria have the typical cell boundary profile of gram-negative bacteria and are enveloped in a vacuolar membrane produced by the host cell. Molecular sequence data of 16S rDNA of endosymbionts of five species of cockroaches and M. darwiniensis indicate that they are members of the Flavobacteria-bacteroides group and that the infection occurred in an ancestor common to cockroaches and termites probably after the end of the Paleozoic (250 Ma BP). The symbiotic bacteria are transmitted transovarially and, during embryogenesis, they are integrated into the morphogenetic processes. In particular, we were able to demonstrate that the origin of the bacteriocyte should be looked for in the cells of the haemocyte line (embryonic plasmatocytes). The eggs are infected by the bacteria emerging from the bacteriocytes of the ovaric fat body and, at the end of the vitellogenesis, they are actively phagocytized by the egg membrane. In filarial nematodes, intracellular bacteria belonging to the genus Wolbachia have been described: they have evolved an obligatory mutualistic association with their host. In fact, antibiotic treatments lead to the clearance of bacteria and this loss produces a negative impact on reproduction and survival of the filarial host. We evidenced, by TEM, the degenerative events occurring during the embriogenesis of Brugia pahangi and Dirofilaria immitis after tetracycline treatment. The data suggest that the Wolbachia play a direct role in worm metabolism. Finally, a new additional model of the prokaryote-eukaryote interaction has been described: we have recently discovered a new intracellular alpha-proteobacterium, named Iric ES1, which resides in the ovarian tissues of the tick Ixodes ricinus. The intriguing characteristic of this bacterium is its ability to invade and consume the ovaric mitochondria. From an evolutionary perspective, it is interesting to note that Iric ES1 enters mitochondria in a similar way to that employed by the "predatory" bacterium Bdellovibrio bacteriovorus.

QuantWorm: a comprehensive software package for Caenorhabditis elegans phenotypic assays.

PubMed

Jung, Sang-Kyu; Aleman-Meza, Boanerges; Riepe, Celeste; Zhong, Weiwei

2014-01-01

Phenotypic assays are crucial in genetics; however, traditional methods that rely on human observation are unsuitable for quantitative, large-scale experiments. Furthermore, there is an increasing need for comprehensive analyses of multiple phenotypes to provide multidimensional information. Here we developed an automated, high-throughput computer imaging system for quantifying multiple Caenorhabditis elegans phenotypes. Our imaging system is composed of a microscope equipped with a digital camera and a motorized stage connected to a computer running the QuantWorm software package. Currently, the software package contains one data acquisition module and four image analysis programs: WormLifespan, WormLocomotion, WormLength, and WormEgg. The data acquisition module collects images and videos. The WormLifespan software counts the number of moving worms by using two time-lapse images; the WormLocomotion software computes the velocity of moving worms; the WormLength software measures worm body size; and the WormEgg software counts the number of eggs. To evaluate the performance of our software, we compared the results of our software with manual measurements. We then demonstrated the application of the QuantWorm software in a drug assay and a genetic assay. Overall, the QuantWorm software provided accurate measurements at a high speed. Software source code, executable programs, and sample images are available at www.quantworm.org. Our software package has several advantages over current imaging systems for C. elegans. It is an all-in-one package for quantifying multiple phenotypes. The QuantWorm software is written in Java and its source code is freely available, so it does not require use of commercial software or libraries. It can be run on multiple platforms and easily customized to cope with new methods and requirements.

Co-evolution between an Endosymbiont and Its Nematode Host: Wolbachia Asymmetric Posterior Localization and AP Polarity Establishment

PubMed Central

Landmann, Frederic; Foster, Jeremy M.; Michalski, Michelle L.; Slatko, Barton E.; Sullivan, William

2014-01-01

While bacterial symbionts influence a variety of host cellular responses throughout development, there are no documented instances in which symbionts influence early embryogenesis. Here we demonstrate that Wolbachia, an obligate endosymbiont of the parasitic filarial nematodes, is required for proper anterior-posterior polarity establishment in the filarial nematode B. malayi. Characterization of pre- and post-fertilization events in B. malayi reveals that, unlike C. elegans, the centrosomes are maternally derived and produce a cortical-based microtubule organizing center prior to fertilization. We establish that Wolbachia rely on these cortical microtubules and dynein to concentrate at the posterior cortex. Wolbachia also rely on PAR-1 and PAR-3 polarity cues for normal concentration at the posterior cortex. Finally, we demonstrate that Wolbachia depletion results in distinct anterior-posterior polarity defects. These results provide a striking example of endosymbiont-host co-evolution operating on the core initial developmental event of axis determination. PMID:25165813

What does not kill them makes them stronger: larval environment and infectious dose alter mosquito potential to transmit filarial worms.

PubMed

Breaux, Jennifer A; Schumacher, Molly K; Juliano, Steven A

2014-07-07

For organisms with complex life cycles, larval environments can modify adult phenotypes. For mosquitoes and other vectors, when physiological impacts of stressors acting on larvae carry over into the adult stage they may interact with infectious dose of a vector-borne pathogen, producing a range of phenotypes for vector potential. Investigation of impacts of a common source of stress, larval crowding and intraspecific competition, on adult vector interactions with pathogens may increase our understanding of the dynamics of pathogen transmission by mosquito vectors. Using Aedes aegypti and the nematode parasite Brugia pahangi, we demonstrate dose dependency of fitness effects of B. pahangi infection on the mosquito, as well as interactions between competitive stress among larvae and infectious dose for resulting adults that affect the physiological and functional ability of mosquitoes to act as vectors. Contrary to results from studies on mosquito-arbovirus interactions, our results suggest that adults from crowded larvae may limit infection better than do adults from uncrowded controls, and that mosquitoes from high-quality larval environments are more physiologically and functionally capable vectors of B. pahangi. Our results provide another example of how the larval environment can have profound effects on vector potential of resulting adults. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

In vitro activities of plant extracts on human Loa loa isolates and cytotoxicity for eukaryotic cells.

PubMed

Mengome, Line-Edwige; Akue, Jean Paul; Souza, Alain; Feuya Tchoua, Guy Raymond; Nsi Emvo, Edouard

2010-08-01

Loa loa, a filarial worm, can cause fatal encephalitis in humans. In an attempt to find alternatives to the standard treatments (ivermectin and diethylcarbamazine citrate), we tested 12 methanolic extracts of nine traditional plant remedies. The extracts (100-0.09 microg/ml) were incubated with 20 Loa loa microfilariae isolated from patients at 37 degrees C with 5% CO(2) in modified Eagle's medium supplemented with 10% fetal serum and antibiotics. Activity was evaluated 120 h later by counting live microfilariae under a microscope. Cytotoxicity for eukaryotic cells was estimated by measuring 3-[4,5-dimethylthiazol-2-yl]-2-5 diphenyl tetrazolium bromide transformation to formazan at 450 nM in a spectrophotometer. The plants tested were Lophira alata, Greenwayodendron suaveolens, Uapaca togoensis, Zanthoxylum heitzii, Peperomia pellucida, Piptadeniastrum africanum, Petersianthus macrocarpus, Vernonia conferta, and Vernonia hymenolepis. Chemical screening showed that most of the extracts contained reducing sugars, tannin or polyphenols, sterols or triterpenes, saponosides, and alkaloids. None contained carotinoids and few contained flavonoids. The 50% lethal concentration ranged from 0.22 to 70.28 microg/ml, while the 50% inhibitory concentration for eukaryotic cells (IC(50)) ranged from 8.52 to 119.52 microg/ml. Extracts of P. macrocarpus (selectivity index = 72.16), P. africanum (13.69), Z. heitzii (12.11), and L. alata (9.26) were highly selective for L. loa.

Growth and development of Gymnophalloides seoi in immunocompetent and immunosuppressed C3H/HeN mice

PubMed Central

Chung, Won-Jae; Kook, Jina; Seo, Min; Park, Yun-Kyu; Guk, Sang-Mee; Choi, Min-Ho; Lee, Soon-Hyung

1999-01-01

The growth and development of Gymnophalloides seoi were studied in C3H/HeN mice and effects of immunosuppression of the host on the worm development were observed. Two hundred metacercariae of G. seoi were orally administered to each mouse, and worms were recovered on days 1, 3, 5, 7, 14 and 21 post-infection (PI). The worm recovery rate was significantly higher in immunosuppressed (ImSP) mice than in immunocompetent (ImCT) mice except on days 1 and 3 PI. The worms attained sexual maturity by day 3 PI with eggs in the uterus, and worm dimensions and the number of uterine eggs continuously increased until day 14 PI in ImSP mice. Worms recovered from ImSP mice were significantly larger in size than those from ImCT mice on days 1 and 3 PI, and the number of uterine eggs was significantly larger in ImSP mice on days 5 and 7 PI. Genital organs such as the ovary, testes, and vitellaria, that were already developed in the metacercarial stage, grew a little in size until day 14 PI. The results show that the C3H/HeN mouse is, though not excellent, a suitable laboratory host for G. seoi. PMID:10188379

WormClassroom.org: An Inquiry-rich Educational Web Portal for Research Resources of Caenorhabditis elegans

PubMed Central

Lu, Fong-Mei; Stewart, James; White, John G.

2007-01-01

The utilization of biology research resources, coupled with a “learning by inquiry” approach, has great potential to aid students in gaining an understanding of fundamental biological principles. To help realize this potential, we have developed a Web portal for undergraduate biology education, WormClassroom.org, based on current research resources of a model research organism, Caenorhabditis elegans. This portal is intended to serve as a resource gateway for students to learn biological concepts using C. elegans research material. The driving forces behind the WormClassroom website were the strengths of C. elegans as a teaching organism, getting researchers and educators to work together to develop instructional materials, and the 3 P's (problem posing, problem solving, and peer persuasion) approach for inquiry learning. Iterative assessment is an important aspect of the WormClassroom site development because it not only ensures that content is up-to-date and accurate, but also verifies that it does, in fact, aid student learning. A primary assessment was performed to refine the WormClassroom website utilizing undergraduate biology students and nonstudent experts such as C. elegans researchers; results and comments were used for site improvement. We are actively encouraging continued resource contributions from the C. elegans research and education community for the further development of WormClassroom. PMID:17548872

Filarial nematode infection in eclectus parrots (Eclectus roratus) in Taiwan.

PubMed

Huang, Yen-Li; Tsai, Shinn-Shyong; Thongchan, Duangsuda; Khatri-Chhetri, Rupak; Wu, Hung-Yi

2017-04-01

A total of 166 psittacines belonging to 22 species were received by the Animal Hospital of National Pingtung University of Science & Technology (NPUST) from 2013 to 2015. Only eclectus parrots (Eclectus roratus) were identified as hosts for microfilariae. All eclectus parrots were adult birds and had been kept in Taiwan for more than three years. The relevance of filariae to eclectus parrots is evident as indicated by the 35.7% (5/14) infection rate. At necropsy, adult filarial nematodes 57-75 mm in length and 0.4-0.7 mm in width were found in the hepatic veins. The microfilariae were 170-230 μm in length. Histopathological examination confirmed that eggs and larvae were observed in the ovaries and uteri of female filariae. These nematodes were closely related to an unidentified Filaria sp. (KJ612514.1) as indicated by polymerase chain reaction (PCR) analysis and phylogenetic analysis of nucleotide sequences from 18S ribosomal DNA gene (18S rDNA), mitochondrial cytochrome c oxidase subunit 1 (COX1) gene, and internal transcribed spacers 1-5.8S ribosomal DNA gene (ITS 1-5.8S rDNA). However, structurally the filarial nematodes were similar to that of the Pelecitus sp. Eclectus parrot species are important pet birds and are highly traded, resulting in high uncertainty of the origin of the parasite infection. This study is the first of its kind to report the presence and potential impact of filarial nematode infection on eclectus parrots, suggesting parasite inspection prior to the international trade of these pet birds.

Recombinant Brugia malayi pepsin inhibitor (rBm33) exploits host signaling events to regulate inflammatory responses associated with lymphatic filarial infections.

PubMed

Sreenivas, Kirthika; Kalyanaraman, Haripriya; Babu, Subash; Narayanan, Rangarajan Badri

2017-11-01

Prolonged existence of filarial parasites and their molecules within the host modulate the host immune system to instigate their survival and induce inflammatory responses that contribute to disease progression. Recombinant Brugia malayi pepsin inhibitor (rBm33) modulates the host immune responses by skewing towards Th1 responses characterized by secretion of inflammatory molecules such as TNF-α, IL-6, nitric oxide (NO). Here we also specified the molecular signaling events triggered by rBm33 in peripheral blood mononuclear cells (PBMCs) of filarial endemic normals (EN). rBm33 predominantly enhanced the levels of nitric oxide in cultured PBMCs but did not result in oxidative stress to the host cells. Further, rBm33 treatment of human PBMCs resulted in higher GSH/GSSG levels. MYD88 dependent activation was found to be associated with rBm33 specific inflammatory cytokine production. rBm33 triggered intracellular signaling events also involved JNK activation in host PBMCs. In addition, c-Fos and not NF-κB was identified as the transcription factor regulating the expression of inflammatory cytokines in rBm33 stimulated PBMCs. rBm33 marked its role in filarial pathology by altered levels of growth factors but did not have a significant impact on matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) activity of host PBMCs. Thus, the study outlines the signaling network of rBm33 induced inflammatory responses within the host immune cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Macrocyclic Lactones-Ivermectin Exposure on Egg Hatching and Larval Development of Caenorhabditis elegans

PubMed Central

Zain, Mariani Mohd; Yahaya, Zary Shariman; Him, Nik Ahmad Irwan Izzauddin Nik

2016-01-01

To date, the ivermectin resistance in nematode parasites has been reported and many studies are carried out to determine the causes of this problem. A free-living Caenorhabditis elegans is used as a model system for this study to investigate the response of C. elegans to ivermectin exposure by using larval development assay. Worms were exposed to ivermectin at concentration from 1 ng/mL to 10 ng/mL and dimethyl sulphoxide (DMSO) as a control. The developments of the worms were monitored for 24, 48, 72, and 96 hours until the worms become adults. Results indicated that worms’ growth began to be affected by ivermectin at a concentration of 5 ng/mL, while at the concentration of 6, 7, 8, 9, and 10 ng/mL, the growth of worms were inhibited compared to control worms. Further study of the protein expression in C. elegans should be done to investigate the up-regulated and down-regulated proteins involve in ivermectin resistance. PMID:27965734

Fluorescence hyperspectral imaging technique for the foreign substance detection on fresh-cut lettuce

USDA-ARS?s Scientific Manuscript database

Nondestructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed in order to detect worms on fresh-cut lettuce. The optimal wavebands for detecting worms on fresh-cut lettuce were investigated using the one-way ANOVA analysis and correlation analysis. The worm detec...

De-worming school children and hygiene intervention.

PubMed

Luong, T V

2003-06-01

Helminths or worm infestations refer to worms that live as parasites in the human body and are a fundamental cause of disease associated with health and nutrition problems beyond gastrointestinal tract disturbances. Globally, over 3.5 billion people are infected with intestinal worms, of which 1.47 billion are with roundworm, 1.3 billion people with hookworm and 1.05 billion with whipworm. School children aged 5 - 15 years suffer the highest infection rate and worm burden that attributes to poor sanitation and hygiene. About 400 million school-age children are infected with roundworm, whipworm and hookworm worldwide, a large proportion of whom are found in the East Asia region (Cambodia, China, Lao PDR, Thailand and Vietnam). These parasites consume nutrients from children they infect, thus retarding their physical development. They destroy tissues and organs, cause abdominal pain, diarrhoea, intestinal obstruction, anaemia, ulcers and other health problems. All of these consequences of infection can slow cognitive development and thus impair learning. De-worming school children by anthelmintic drug treatment is a curative approach for expelling the heavy worm load. However, drug therapy alone is only a short-term measure of reducing worm infection and re-infection is frequent. Control measures through improved sanitation, hygiene and de-worming are needed to prevent infection and re-infection. UNICEF has supported many governments in this (and other) regions to assist in the provision of water supply and sanitary facilities and intensive hygiene education in many schools through the Water, Environment and Sanitation (WES) programme. The UNICEF supported school sanitation and hygiene education (SSHE) programme, and other programmes, could effectively enhance behaviour change in children to break the routes of worm transmission and other waterborne diseases.

Preliminary effects of water hardness on triactinomyxon production and development from eastern tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Waldrop, Thomas B.; Densmore, Christine; Blazer, Vicki; Smith, Dave; Schill, Bane; Schill, B.; Waldrop, T.; Blazer, V.

1999-01-01

Whirling disease is caused by Myxobolus cerebralis and requires an intermediate oligochaete host identified as Tubifex tubifex (Wolf, Markiw, and Hiltunen, 1986). M. cerebralis spores ingested by the tubifex worms develop into triactinomyxons (tams) that are eventually released into the water column to infect salmonid fish. There may be many environmental parameters, biotic or abiotic, that may affect the development of waterborne tams in eastern tubifex worms. This study will focus on one of those environmental parameters, total water hardness. Total water hardness is defined as the concentration of calcium and magnesium in a water sample expressed in milligrams per liter of equivalent CACO3 (Boyd, 1990). This study will address whether different levels of water hardness affect the development and production of tams released by infected tubifex worms.

Comparative pattern of growth and development of Echinostoma paraensei (Digenea: Echinostomatidae) in hamster and Wistar rat using light and confocal laser scanning microscopy.

PubMed

Souza, Joyce G R; Garcia, Juberlan S; Gomes, Ana Paula N; Machado-Silva, José Roberto; Maldonado, Arnaldo

2017-12-01

Echinostoma paraensei (Digenea: Echinostomatidae) lives in the duodenum and bile duct of rodents and is reported as a useful model for studies on the biology of flatworms. Here, we compared the growth and development of pre and post ovigerous worms collected 3, 7, 14 and 21 days post infection from experimentally infected hamster (permissive host) and Wistar rat (less permissive hosts). Linear measurements and ratios were examined by light (morphology and morphometry) and confocal laser scanning microscopy. At day 3, either worm from hamsters or rats were small with poorly developed gonads. At seven day, worms increased in size and morphometric differences between hosts are statistically significant after this time. In addition, adult worms (14 and 21 days of age) harvested from hamster showed developed gonads and vitelline glands laterally distributed on the body, whereas worms from rat showed atrophied reproductive system characterized by underdeveloped vitelline glands and stunted ovary. The worm rate recovery in rat decreased from 29.3% (day 7) to 20.6% (day 14) and 8% (day 21), whilst it remained around 37% in hamster. In conclusion, this is the first appointment demonstrating that low permissiveness influences the reproductive system of echinostome since the immature stages of development. The phenotypic analysis evidenced that hamster provides a more favorable microenvironment for gonads development than rat, confirming golden hamster as a permissive host, whereas Wistar rat is less permissive host. Copyright © 2017 Elsevier Inc. All rights reserved.

Lymphatic filarial species differentiation using evolutionarily modified tandem repeats: generation of new genetic markers.

PubMed

Sakthidevi, Moorthy; Murugan, Vadivel; Hoti, Sugeerappa Laxmanappa; Kaliraj, Perumal

2010-05-01

Polymerase chain reaction based methods are promising tools for the monitoring and evaluation of the Global Program for the Elimination of Lymphatic Filariasis. The currently available PCR methods do not differentiate the DNA of Wuchereria bancrofti or Brugia malayi by a single PCR and hence are cumbersome. Therefore, we designed a single step PCR strategy for differentiating Bancroftian infection from Brugian infection based on a newly identified gene from the W. bancrofti genome, abundant larval transcript-2 (alt-2), which is abundantly expressed. The difference in PCR product sizes generated from the presence or absence of evolutionarily altered tandem repeats in alt-2 intron-3 differentiated W. bancrofti from B. malayi. The analysis was performed on the genomic DNA of microfilariae from a number of patient blood samples or microfilariae positive slides from different Indian geographical regions. The assay gave consistent results, differentiating the two filarial parasite species accurately. This alt-2 intron-3 based PCR assay can be a potential tool for the diagnosis and differentiation of co-infections by lymphatic filarial parasites. Copyright (c) 2010 Elsevier B.V. All rights reserved.

New Geometry of Worm Face Gear Drives with Conical and Cylindrical Worms: Generation, Simulation of Meshing, and Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Nava, Alessandro; Fan, Qi; Fuentes, Alfonso

2002-01-01

New geometry of face worm gear drives with conical and cylindrical worms is proposed. The generation of the face worm-gear is based on application of a tilted head-cutter (grinding tool) instead of application of a hob applied at present. The generation of a conjugated worm is based on application of a tilted head-cutter (grinding tool) as well. The bearing contact of the gear drive is localized and is oriented longitudinally. A predesigned parabolic function of transmission errors for reduction of noise and vibration is provided. The stress analysis of the gear drive is performed using a three-dimensional finite element analysis. The contacting model is automatically generated. The developed theory is illustrated with numerical examples.

Galactolipids from Bauhinia racemosa as a new class of antifilarial agents against human lymphatic filarial parasite, Brugia malayi.

PubMed

Sashidhara, Koneni V; Singh, Suriya P; Misra, Sweta; Gupta, Jyoti; Misra-Bhattacharya, Shailja

2012-04-01

Bioassay guided fractionation of ethanolic extract of the leaves of Bauhinia racemosa led to the isolation of galactolipid and catechin class of the compounds (1-7) from the most active n-butanol fraction (F4). Among the active galactolipids, 1 emerged as the lead molecule which was active on both forms of lymphatic filarial parasite, Brugia malayi. It was found to be better than the standard drug ivermectin and diethylcarbamazine (DEC) in terms of dose and efficacy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Microfluidic Devices in Advanced Caenorhabditis elegans Research.

PubMed

Muthaiyan Shanmugam, Muniesh; Subhra Santra, Tuhin

2016-08-02

The study of model organisms is very important in view of their potential for application to human therapeutic uses. One such model organism is the nematode worm, Caenorhabditis elegans. As a nematode, C. elegans have ~65% similarity with human disease genes and, therefore, studies on C. elegans can be translated to human, as well as, C. elegans can be used in the study of different types of parasitic worms that infect other living organisms. In the past decade, many efforts have been undertaken to establish interdisciplinary research collaborations between biologists, physicists and engineers in order to develop microfluidic devices to study the biology of C. elegans. Microfluidic devices with the power to manipulate and detect bio-samples, regents or biomolecules in micro-scale environments can well fulfill the requirement to handle worms under proper laboratory conditions, thereby significantly increasing research productivity and knowledge. The recent development of different kinds of microfluidic devices with ultra-high throughput platforms has enabled researchers to carry out worm population studies. Microfluidic devices primarily comprises of chambers, channels and valves, wherein worms can be cultured, immobilized, imaged, etc. Microfluidic devices have been adapted to study various worm behaviors, including that deepen our understanding of neuromuscular connectivity and functions. This review will provide a clear account of the vital involvement of microfluidic devices in worm biology.

Treatment of third-stage larvae of Toxocara cati with milbemycin oxime plus praziquantel tablets and emodepside plus praziquantel spot-on formulation in experimentally infected cats.

PubMed

Wolken, Sonja; Böhm, Claudia; Schaper, Roland; Schnieder, Thomas

2012-11-01

Toxocara cati is the most prevalent gastrointestinal helminth in cats worldwide, with cats of all ages at risk of infection. An anthelminthic treatment that not only affects the gut-dwelling stages of this parasite but is also effective against developmental stages in the tissue has the advantage that the pathology caused by migrating larvae is minimized and the need for repeated treatments is reduced. This study was conducted to evaluate the efficacy of milbemycin oxime/praziquantel tablets (Milbemax®, Novartis) against third-stage larvae of T. cati in comparison to a spot-on formulation of emodepside and praziquantel (Profender®, Bayer). Twenty-four kittens were experimentally infected with T. cati and randomly allocated to three study groups. Treatments were performed at the minimum therapeutic dosage 5 days after the experimental infection. The development of patent infections was monitored and all cats were dewormed 50 days post-infection. Efficacies were calculated based on counts of excreted worms in the treated groups compared to a negative control group. Seven of the eight cats in the negative control group developed a patent T. cati infection and all cats were excreting worms at the end of the study (geometric mean worm count 18.1). No efficacy could be observed for the milbemycin oxime-treated animals. All cats developed a patent infection and excreted worms (geometric mean worm count 27.7). The treatment with Profender® was 98.5 % effective against L3 of T. cati. One cat developed a patent infection and was excreting worms at the end of the study (geometric mean worm count 0.3). No adverse reactions were noted in either treatment group.

Drpiwi-1 is essential for germline cell formation during sexualization of the planarian Dugesia ryukyuensis.

PubMed

Nakagawa, Haruka; Ishizu, Hirotsugu; Hasegawa, Reiko; Kobayashi, Kazuya; Matsumoto, Midori

2012-01-01

A piwi homolog is required for the regulation of stem cells, formation and maintenance of germline stem cells, and gametogenesis in many metazoans. Planarians can change their reproductive mode seasonally, both asexually and sexually, and develop and maintain germ cells and sexual organs. They have many pluripotent stem cells (neoblasts) that can differentiate into both somatic and germline stem cells. Thus, we searched for a piwi subfamily in the planarian Dugesia ryukyuensis. Four piwi homologs, identified as Drpiwi-1, -2, -3, and -4, were expressed in sexually reproductive worms. We then selectively destroyed the neoblasts by irradiating the worms with X-rays. In such worms, Drpiwi-1, -2, and -3 were not expressed at all, whereas Drpiwi-4 was expressed to the same degree as that in non-irradiated controls, indicating that Drpiwi-1, -2, and -3, but not Drpiwi-4, are expressed in neoblasts. During the regeneration process, Drpiwi-2(RNAi) and -3(RNAi) worms failed to regenerate after ablation, but Drpiwi-1 and -4(RNAi) worms regenerated. During the sexualizing process, Drpiwi-1(RNAi) worms failed to develop ovaries and testes, but somatic sexual organs were unaffected. Germ cell development was normal in Drpiwi-4(RNAi) worms. Therefore, Drpiwi-2 and -3 may be related to the regulation of neoblasts important for maintaining homeostasis, and Drpiwi-1 is essential for the development of germ cells but not somatic sexual organs. DrPiwi-1 is localized in the cytoplasm of stem cells and germline cells and may be involved in regulating some gene expression. We suggest that planarian Piwi controls germline formation via RNA silencing mechanisms. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

The research of hourglass worm dynamic balancing simulation based on SolidWorks motion

NASA Astrophysics Data System (ADS)

Wang, Zhuangzhuang; Yang, Jie; Liu, Pingyi; Zhao, Junpeng

2018-02-01

Hourglass worm is extensively used in industry due to its characteristic of heavy-load and a large reduction ratio. Varying sizes of unbalanced mass distribution appeared in the design of a single head worm. With machines developing towards higher speed and precision, the vibration and shock caused by the unbalanced mass distribution of rotating parts must be considered. Therefore, the balance grade of these parts must meet higher requirements. A method based on theoretical analysis and SolidWorks motion software simulation is presented in this paper; the virtual dynamic balance simulation test of the hourglass worm was carried out during the design of the product, so as to ensure that the hourglass worm meet the requirements of dynamic balance in the design process. This can effectively support the structural design of the hourglass worm and provide a way of thinking and designing the same type of products.

Central nervous system filariasis masquerading as a glioma: case report.

PubMed

Shrivastava, Adesh; Arora, Prateek; Khare, Akriti; Goel, Garima; Kapoor, Neelkamal

2017-09-01

Filariasis, an endemic zoonosis in the Southeast Asia region, has been reported to affect various organs as well as the central nervous system (CNS). Inflammatory reactions mimicking those from neoplastic lesions clinically and radiologically have been reported in the breast and urinary bladder. To date, a CNS manifestation of filarial infestation has been reported in the form of meningoencephalitis. The authors here present an interesting case of a young man presenting in status epilepticus, which on radiological evaluation appeared to be a glioma. However, postoperative histopathological examination changed the provisional diagnosis to a filarial infection of the CNS mimicking a primary CNS neoplasm.

WORM - WINDOWED OBSERVATION OF RELATIVE MOTION

NASA Technical Reports Server (NTRS)

Bauer, F.

1994-01-01

The Windowed Observation of Relative Motion, WORM, program is primarily intended for the generation of simple X-Y plots from data created by other programs. It allows the user to label, zoom, and change the scale of various plots. Three dimensional contour and line plots are provided, although with more limited capabilities. The input data can be in binary or ASCII format, although all data must be in the same format. A great deal of control over the details of the plot is provided, such as gridding, size of tick marks, colors, log/semilog capability, time tagging, and multiple and phase plane plots. Many color and monochrome graphics terminals and hard copy printer/plotters are supported. The WORM executive commands, menu selections and macro files can be used to develop plots and tabular data, query the WORM Help library, retrieve data from input files, and invoke VAX DCL commands. WORM generated plots are displayed on local graphics terminals and can be copied using standard hard copy capabilities. Some of the graphics features of WORM include: zooming and dezooming various portions of the plot; plot documentation including curve labeling and function listing; multiple curves on the same plot; windowing of multiple plots and insets of the same plot; displaying a specific on a curve; and spinning the curve left, right, up, and down. WORM is written in PASCAL for interactive execution and has been implemented on a DEC VAX computer operating under VMS 4.7 with a virtual memory requirement of approximately 392K of 8 bit bytes. It uses the QPLOT device independent graphics library included with WORM. It was developed in 1988.

Examination of the relationship between host worm community structure on transmission of the parasite, Myxobolus cerebralis by developing taxon-specific probes for multiplex qPCR to identify worm taxa in stream communities

NASA Astrophysics Data System (ADS)

Fytilis, N.; Lamb, R.; Kerans, B.; Stevens, L.; Rizzo, D. M.

2011-12-01

Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling the non-linear relationships between disease dynamics, stream dwelling oligochaete communities and geochemical features. Myxobolus cerebralis, the causative agent of whirling disease in salmonid fishes, has been a major contributor to the loss of wild rainbow trout populations in numerous streams within the Intermountain West. The parasite alternates between an invertebrate and vertebrate host, being transmitted between the sediment feeding worm Tubifex tubifex (T.tubifex) and salmonid fishes. Worm community biodiversity and abundance are influenced by biogeochemical features and have been linked to disease severity in fish. The worm (T.tubifex) lives in communities with 3-4 other types of worms in stream sediments. Unfortunately, taxonomic identification of oligochaetes is largely dependent on morphological characteristics of sexually mature adults. We have collected and identified ~700 worms from eight sites using molecular genetic probes and a taxonomic key. Additionally, ~1700 worms were identified using only molecular genetic probes. To facilitate distinguishing among tubificids, we developed two multiplex molecular genetic probe-based quantitative polymerase reaction (qPCR) assays to assess tubificid communities in the study area. Similar qPCR techniques specific for M.cerebralis used to determine if individual worms were infected with the parasite. We show how simple Bayesian analysis of the qPCR data can predict the worm community structure and reveal relationships between biodiversity of host communities and host-parasite dynamics. To our knowledge, this is the first study that combines molecular data of both the host and the parasite to examine the effects of host community structure on the transmission of a parasite. Our work can be extended to examine the links between worm community structure and biogeochemical features using molecular genetics and Bayesian statistics to assist in identifying new nonlinear relationships and suggest new subsets of input parameters. Future work includes the development of a new complex systems tool capable of assimilating biological DNA sequence data and biogeochemical features using artificial neural networks and Bayesian analysis. The methodologies developed here helped mine the relationships between biodiversity of host communities and host-parasite dynamics. The results from our study will be useful to managers and researchers for assessing the risk of whirling disease in drainages where tubificid community composition data are needed. This collaboration between modelers, field ecologists and geneticists will prove useful in modeling efforts and will enable more effective, high-volume hypothesis generation. The ability to characterize areas of high whirling disease risk is essential for improving our understanding of the dynamics of M.cerebralis such that appropriate management strategies can be implemented.

OpenWorm: an open-science approach to modeling Caenorhabditis elegans.

PubMed

Szigeti, Balázs; Gleeson, Padraig; Vella, Michael; Khayrulin, Sergey; Palyanov, Andrey; Hokanson, Jim; Currie, Michael; Cantarelli, Matteo; Idili, Giovanni; Larson, Stephen

2014-01-01

OpenWorm is an international collaboration with the aim of understanding how the behavior of Caenorhabditis elegans (C. elegans) emerges from its underlying physiological processes. The project has developed a modular simulation engine to create computational models of the worm. The modularity of the engine makes it possible to easily modify the model, incorporate new experimental data and test hypotheses. The modeling framework incorporates both biophysical neuronal simulations and a novel fluid-dynamics-based soft-tissue simulation for physical environment-body interactions. The project's open-science approach is aimed at overcoming the difficulties of integrative modeling within a traditional academic environment. In this article the rationale is presented for creating the OpenWorm collaboration, the tools and resources developed thus far are outlined and the unique challenges associated with the project are discussed.

Vector competence of Aedes aegypti mosquitoes for filarial nematodes is affected by age and nutrient limitation.

PubMed

Ariani, Cristina V; Juneja, Punita; Smith, Sophia; Tinsley, Matthew C; Jiggins, Francis M

2015-01-01

Mosquitoes are one of the most important vectors of human disease. The ability of mosquitoes to transmit disease is dependent on the age structure of the population, as mosquitoes must survive long enough for the parasites to complete their development and infect another human. Age could have additional effects due to mortality rates and vector competence changing as mosquitoes senesce, but these are comparatively poorly understood. We have investigated these factors using the mosquito Aedes aegypti and the filarial nematode Brugia malayi. Rather than observing any effects of immune senescence, we found that older mosquitoes were more resistant, but this only occurred if they had previously been maintained on a nutrient-poor diet of fructose. Constant blood feeding reversed this decline in vector competence, meaning that the number of parasites remained relatively unchanged as mosquitoes aged. Old females that had been maintained on fructose also experienced a sharp spike in mortality after an infected blood meal ("refeeding syndrome") and few survived long enough for the parasite to develop. Again, this effect was prevented by frequent blood meals. Our results indicate that old mosquitoes may be inefficient vectors due to low vector competence and high mortality, but that frequent blood meals can prevent these effects of age. Copyright © 2014 Elsevier Inc. All rights reserved.

Extraintestinal nematodes of the red fox Vulpes vulpes in north-west Italy.

PubMed

Magi, M; Guardone, L; Prati, M C; Mignone, W; Macchioni, F

2015-07-01

Extraintestinal nematodes of the red fox (Vulpes vulpes) are a wide group of parasites that infect wild and domestic carnivores and occasionally humans. Nematodes in the cardiopulmonary system, stomach, urinary apparatus and muscle tissue of 165 red foxes (Vulpes vulpes) from north-west Italy (Liguria and Piedmont) were investigated between 2009 and 2012. Of the cardiopulmonary nematodes, a high prevalence of Angiostrongylus vasorum and Eucoleus aerophilus (syn. Capillaria aerophila) was found, 78.2% and 41.8% respectively; Crenosoma vulpis (15.8%) and Filaroides spp. (4.8%) were also found. Spirocerca lupi (23.5%), Aonchotheca putorii (syn. Capillaria putorii) (8.6%) and Physaloptera spp. (2.5%) were detected in the stomach and Pearsonema plica (syn. Capillaria plica) (56.8%) in the bladder. Eucoleus boehmi (syn. Capillaria boehmi) was also detected in the nasal cavities of one of the two foxes examined. A coprological examination revealed eggs of E. aerophilus, A. putorii, S. lupi, Physaloptera spp. and eggs of intestinal parasites. Filarial worms were absent in all the 165 animals examined, nor was there evidence of Trichinella spp. in any of the foxes. The foxes were found to host a high prevalence of many species of extraintestinal nematodes. The prevalence of A. vasorum in foxes found in the present study is among the highest in Europe. In addition, to the best of our knowledge, E. boehmi and Filaroides spp. have never been reported before in this host in Italy.

Cloning and characterization of an Echinococcus granulosus ecdysteroid hormone nuclear receptor HR3-like gene

PubMed Central

Yang, Mei; Li, Jun; Wu, Jun; Wang, Hui; Guo, Baoping; Wu, Chuanchuan; Shou, Xi; Yang, Ning; Zhang, Zhuangzhi; McManus, Donald P.; Zhang, Fuchun; Zhang, Wenbao

2017-01-01

Cystic echinococcosis is an important parasitic zoonosis caused by the dog tapeworm Echinococcus granulosus. Little is known about adult worm development at the molecular level. Transcription analysis showed that the E. granulosus hormone receptor 3-like (EgHR3) gene was expressed in protoscoleces and adult worms, indicating its role in early adult development. In this study, we cloned and characterized EgHR3 showing that its cDNA contains an open reading frame (ORF) of 1890 bp encoding a 629 amino acid protein, which has a DNA-binding domain (DBD) and a ligand-binding domain (LBD). Immunolocalization revealed the protein was localized in the parenchyma of protoscoleces and adult worms. Real-time PCR analysis showed that EgHR3 was expressed significantly more in adults than in other stages of development (p<0.01) and that its expression was especially high in the early stage of adult worm development induced by bile acids. EgHR3 siRNA silenced 69–78% of the level of transcription in protoscoleces, which resulted in killing 43.6–60.9% of protoscoleces after 10 days of cultivation in vitro. EgHR3 may play an essential role in early adult worm development and in maintaining adult biological processes and may represent a novel drug or vaccine target against echinococcosis. PMID:28971798

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stephenson, G.L.; Scroggins, R.

Environment Canada has embarked on a five year program to develop, standardize, and validate a battery of soil toxicity tests which can be used to assess the relative toxicity of contaminants in soils to terrestrial organisms. These tests must be applicable to soil conditions typically found in Canadian environments and the test species must be representative of the species of soil invertebrates or plants inhabiting soil ecosystems in Canada. One of the toxicity tests being developed is designed to assess the toxicity of contaminated soils to earthworms. Five of the potential test species belong to the Lumbricidae family and includemore » the Canadian worm (Allobophora calignosa/Aporrectodea tuberculate), the European bark worm (Dendrodtilus rubidus (rubida)), the pink soil worm (Eisenia rosea), the red marsh worm (Lumbricus rubellus), and the Canadian night crawler or dew worm (Lumbricus terrestris). The sixth species, the white pot worm (Enchytraeus albidus), belongs to the Enchytraeidae family. Further assessment reduced the number of representative species to three. Most earthworm test methods have been developed to assess the toxicity of chemically-spiked artificial soils to Eisenia fetida or E. andrei. Test methods have also been developed to assess the relative toxicity of contaminated soils from hazardous waste sites. Comparative acute toxicity data for three species of earthworm exposed to a hydrocarbon contamination will be presented. Comparative toxicity data for the same three species of earthworm will also be presented using test procedures and conditions that have been modified to accommodate biological differences among the species of earthworm. Recommendations regarding test design, methods, and conditions optimal for each test species will be summarized and discussed with respect to the precision of test results.« less

Worm epidemics in wireless ad hoc networks

NASA Astrophysics Data System (ADS)

Nekovee, Maziar

2007-06-01

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

A pilot study on the status of lymphatic filariasis in a rural community of Bihar.

PubMed

Das, V N R; Siddiqui, N A; Kumar, N; Verma, N; Verma, R B; Dinesh, D S; Kar, S K; Das, P

2006-03-01

A pilot study of lymphatic filariasis was conducted in two contiguous villages of Patna district in Bihar situated at the side of the river Ganges, known to be endemic for lymphatic filariasis, to study present status of transmission parameters of filariasis. Of the 1872 persons examined, 8.4% were found asymptomatic but microfilaraemic. Morbidity pattern due to filarial infection showed an increase with advancement of age and significantly high in males as compared to female (p < 0.001). Acute and chronic filarial disease was observed as 0.5% and 9% respectively. Microfilaria was found in 10% of acute and 11.2% of chronic filarial cases. The Mf rate was found to be 9.9% in males and 9.0% in females respectively. The parasite species was identified as W. bancrofti. The vector fauna surveyed show highest prevalence of vector species of Cx. quinquefasciatus (43%) in both domestic as well as predomestic area in the community. Other species like Cx. vishnui and Ma. uniformis were also seen. Each household and predomestic area was searched for mosquito fauna at night. The infection rate in vectors was found to be 14% and infectivity rate (L3) was 8%. The filariasis cases detected in the study were treated with 12 days course of DEC 6 mg/kg body weight.

Dirofilaria, visceral larva migrans, and tropical pulmonary eosinophilia.

PubMed

Chitkara, R K; Sarinas, P S

1997-06-01

Helminthic infections are prevalent worldwide. The intestinal ascarid, Toxocara, the animal filarial parasite, Dirofilaria, and the human filarial parasite, Wuchereria or Brugia, produce an array of pulmonary disease in humans. Infections are common in temperate, tropical, and subtropical regions of the world. Pulmonary dirofilariasis is essentially an asymptomatic disease. Most cases are diagnosed accidentally after thoracotomy for a solitary pulmonary nodule presumed to be lung cancer. Clinical manifestations of toxocariasis or visceral larva migrans (VLM) are the result of allergic and inflammatory responses of the host, and manifest with airway reactivity, acute pneumonia, and persistent eosinophilia. VLM is a self-limited disease and specific treatment is rarely necessary. In acute cases, a short course of steroids reduces morbidity and mortality but preventive measures are more important in curbing toxocara infection. Tropical pulmonary eosinophilia (TPE) is the result of immunologic hyperresponsiveness to the human filarial antigen and eosinophils play a crucial role in its pathogenesis. Airway hyperreactivity, extreme eosinophilia, and pulmonary physiologic impairment are the characteristic features. Treatment of TPE with diethylcarbamazine results in dramatic amelioration of symptoms. However, low grade inflammation persists in a significant number of patients and can lead to chronic interstitial lung disease. Mass treatment of patients in certain endemic areas has been effective in eliminating TPE.

Discrimination methods for biological contaminants in fresh-cut lettuce based on VNIR and NIR hyperspectral imaging

NASA Astrophysics Data System (ADS)

Mo, Changyeun; Kim, Giyoung; Kim, Moon S.; Lim, Jongguk; Lee, Seung Hyun; Lee, Hong-Seok; Cho, Byoung-Kwan

2017-09-01

The rapid detection of biological contaminants such as worms in fresh-cut vegetables is necessary to improve the efficiency of visual inspections carried out by workers. Multispectral imaging algorithms were developed using visible-near-infrared (VNIR) and near-infrared (NIR) hyperspectral imaging (HSI) techniques to detect worms in fresh-cut lettuce. The optimal wavebands that can detect worms in fresh-cut lettuce were investigated for each type of HSI using one-way ANOVA. Worm-detection imaging algorithms for VNIR and NIR imaging exhibited prediction accuracies of 97.00% (RI547/945) and 100.0% (RI1064/1176, SI1064-1176, RSI-I(1064-1173)/1064, and RSI-II(1064-1176)/(1064+1176)), respectively. The two HSI techniques revealed that spectral images with a pixel size of 1 × 1 mm or 2 × 2 mm had the best classification accuracy for worms. The results demonstrate that hyperspectral reflectance imaging techniques have the potential to detect worms in fresh-cut lettuce. Future research relating to this work will focus on a real-time sorting system for lettuce that can simultaneously detect various defects such as browning, worms, and slugs.

Parasite-Antigen Driven Expansion of IL-5− and IL-5+ Th2 Human Subpopulations in Lymphatic Filariasis and Their Differential Dependence on IL-10 and TGFβ

PubMed Central

Anuradha, Rajamanickam; George, Parakkal Jovvian; Hanna, Luke E.; Chandrasekaran, Vedachalam; Kumaran, P. Paul; Nutman, Thomas B.; Babu, Subash

2014-01-01

Background Two different Th2 subsets have been defined recently on the basis of IL-5 expression – an IL-5+Th2 subset and an IL-5−Th2 subset in the setting of allergy. However, the role of these newly described CD4+ T cells subpopulations has not been explored in other contexts. Methods To study the role of the Th2 subpopulation in a chronic, tissue invasive parasitic infection (lymphatic filariasis), we examined the frequency of IL-5+IL-4+IL-13+ CD4+ T cells and IL-5−IL-4 IL-13+ CD4+ T cells in asymptomatic, infected individuals (INF) and compared them to frequencies (Fo) in filarial-uninfected (UN) individuals and to those with filarial lymphedema (CP). Results INF individuals exhibited a significant increase in the spontaneously expressed and antigen-induced Fo of both Th2 subpopulations compared to the UN and CP. Interestingly, there was a positive correlation between the Fo of IL-5+Th2 cells and the absolute eosinophil and neutrophil counts; in addition there was a positive correlation between the frequency of the CD4+IL-5−Th2 subpopulation and the levels of parasite antigen – specific IgE and IgG4 in INF individuals. Moreover, blockade of IL-10 and/or TGFβ demonstrated that each of these 2 regulatory cytokines exert opposite effects on the different Th2 subsets. Finally, in those INF individuals cured of infection by anti-filarial therapy, there was a significantly decreased Fo of both Th2 subsets. Conclusions Our findings suggest that both IL-5+ and IL-5−Th2 cells play an important role in the regulation of immune responses in filarial infection and that these two Th2 subpopulations may be regulated by different cytokine-receptor mediated processes. PMID:24498448

Neutropenic Mice Provide Insight into the Role of Skin-Infiltrating Neutrophils in the Host Protective Immunity against Filarial Infective Larvae

PubMed Central

Pionnier, Nicolas; Brotin, Emilie; Karadjian, Gregory; Hemon, Patrice; Gaudin-Nomé, Françoise; Vallarino-Lhermitte, Nathaly; Nieguitsila, Adélaïde; Fercoq, Frédéric; Aknin, Marie-Laure; Marin-Esteban, Viviana; Chollet-Martin, Sylvie; Schlecht-Louf, Géraldine

2016-01-01

Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs. Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013). We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin. Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3). This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice. Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3. Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin. Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET). This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host. Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis. PMID:27111140

Robust tracking and quantification of C. elegans body shape and locomotion through coiling, entanglement, and omega bends

PubMed Central

Roussel, Nicolas; Sprenger, Jeff; Tappan, Susan J; Glaser, Jack R

2014-01-01

The behavior of the well-characterized nematode, Caenorhabditis elegans (C. elegans), is often used to study the neurologic control of sensory and motor systems in models of health and neurodegenerative disease. To advance the quantification of behaviors to match the progress made in the breakthroughs of genetics, RNA, proteins, and neuronal circuitry, analysis must be able to extract subtle changes in worm locomotion across a population. The analysis of worm crawling motion is complex due to self-overlap, coiling, and entanglement. Using current techniques, the scope of the analysis is typically restricted to worms to their non-occluded, uncoiled state which is incomplete and fundamentally biased. Using a model describing the worm shape and crawling motion, we designed a deformable shape estimation algorithm that is robust to coiling and entanglement. This model-based shape estimation algorithm has been incorporated into a framework where multiple worms can be automatically detected and tracked simultaneously throughout the entire video sequence, thereby increasing throughput as well as data validity. The newly developed algorithms were validated against 10 manually labeled datasets obtained from video sequences comprised of various image resolutions and video frame rates. The data presented demonstrate that tracking methods incorporated in WormLab enable stable and accurate detection of these worms through coiling and entanglement. Such challenging tracking scenarios are common occurrences during normal worm locomotion. The ability for the described approach to provide stable and accurate detection of C. elegans is critical to achieve unbiased locomotory analysis of worm motion. PMID:26435884

Biosynthesis in vitro of Caenorhabditis elegans phosphorylcholine oligosaccharides

PubMed Central

Cipollo, John F.; Awad, Antoine; Costello, Catherine E.; Robbins, Phillips W.; Hirschberg, Carlos B.

2004-01-01

The biosynthesis in vitro of phosphorylcholine oligosaccharides in Caenorhabditis elegans has been investigated. Here we show that extracts of C. elegans' microsomes transfer phosphorylcholine from L-α-dipalmitoyl phosphatidylcholine to hybrid and complex type N-linked oligosaccharides containing mannose residues disubstituted with N-acetylglucosamine. The reaction products are consistent with structures reported for C. elegans as well those found in the filarial nematodes Acanthocheilonema viteae, Onchocerca volvulus, and Brugia malayi, strongly supporting the concept that the phosphorylcholine oligosaccharide biosynthetic enzymes are conserved in this group of organisms. Because it is thought that phosphorylcholine substitution of oligosaccharides modulates host immune response in filarial infections, this in vitro system may help in gaining an understanding of the basis for this response. PMID:14993596

Prospects and challenges of CRISPR/Cas genome editing for the study and control of neglected vector-borne nematode diseases.

PubMed

Zamanian, Mostafa; Andersen, Erik C

2016-09-01

Neglected tropical diseases caused by parasitic nematodes inflict an immense health and socioeconomic burden throughout much of the developing world. Current estimates indicate that more than two billion people are infected with nematodes, resulting in the loss of 14 million disability-adjusted life years per annum. Although these parasites cause significant mortality, they primarily cause chronic morbidity through a wide range of severe clinical ailments. Treatment options for nematode infections are restricted to a small number of anthelmintic drugs, and the rapid expansion of anthelmintic mass drug administration raises concerns of drug resistance. Preservation of existing drugs is necessary, as well as the development of new treatment options and methods of control. We focus this review on how the democratization of CRISPR/Cas9 genome editing technology can be enlisted to improve our understanding of the biology of nematode parasites and our ability to treat the infections they cause. We will first explore how this robust method of genome manipulation can be used to newly exploit the powerful model nematode Caenorhabditis elegans for parasitology research. We will then discuss potential avenues to develop CRISPR/Cas9 editing protocols in filarial nematodes. Lastly, we will propose potential ways in which CRISPR/Cas9 can be used to engineer gene drives that target the transmission of mosquito-borne filarial nematodes. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Computer modelling of anthelmintic resistance and worm control outcomes for refugia-based nematode control strategies in Merino ewes in Western Australia.

PubMed

Cornelius, M P; Jacobson, C; Dobson, R; Besier, R B

2016-04-15

This study utilised computer simulation modelling (Risk Management Model for Nematodes) to investigate the impact of different parasite refugia scenarios on the development of anthelmintic resistance and worm control effectiveness. The simulations were conducted for adult ewe flocks in a Mediterranean climatic region over a 20 year time period. Factors explored in the simulation exercise were environment (different weather conditions), drug efficacy, the percentage of the flock left untreated, the timing of anthelmintic treatments, the initial worm egg count, and the number of drenches per annum. The model was run with variable proportions of the flock untreated (0, 10, 20, 30, 40 and 50%), with ewes selected at random so that reductions in the mean worm burden or egg count were proportional to the treated section of the flock. Treatments to ewes were given either in summer (December; low refugia potential, hence highly selective) or autumn (March; less selective due to a greater refugia potential), and the use of different anthelmintics was simulated to indicate the difference between active ingredients of different efficacy. Each model scenario was run for two environments, specifically a lower rainfall area (more selective) and a higher rainfall area (less selective) within a Mediterranean climatic zone, characterised by hot, dry summers and cool, wet winters. Univariate general linear models with least square difference post-hoc tests were used to examine differences between means of factors. The results confirmed that leaving a proportion of sheep in a flock untreated was effective in delaying the development of anthelmintic resistance, with as low as 10% of a flock untreated sufficient to significantly delay resistance, although this strategy was associated with a small reduction in worm control. Administering anthelmintics in autumn rather than summer was also effective in delaying the development of anthelmintic resistance in the lower rainfall environment where all sheep were treated, although the effect of treatment timing on worm control effectiveness varied between the environments and the proportion of ewes left untreated. The use of anthelmintics with higher efficacy delayed the development of resistance, but the initial worm egg count or number of annual treatments had no effect on either the time to resistance development or worm control effectiveness. In conclusion, the modelling study suggests that leaving a small proportion of ewes untreated, or changing the time of treatment, can delay the onset of anthelmintic resistance in a highly selective environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Track-A-Worm, An Open-Source System for Quantitative Assessment of C. elegans Locomotory and Bending Behavior

PubMed Central

Wang, Sijie Jason; Wang, Zhao-Wen

2013-01-01

A major challenge of neuroscience is to understand the circuit and gene bases of behavior. C. elegans is commonly used as a model system to investigate how various gene products function at specific tissue, cellular, and synaptic foci to produce complicated locomotory and bending behavior. The investigation generally requires quantitative behavioral analyses using an automated single-worm tracker, which constantly records and analyzes the position and body shape of a freely moving worm at a high magnification. Many single-worm trackers have been developed to meet lab-specific needs, but none has been widely implemented for various reasons, such as hardware difficult to assemble, and software lacking sufficient functionality, having closed source code, or using a programming language that is not broadly accessible. The lack of a versatile system convenient for wide implementation makes data comparisons difficult and compels other labs to develop new worm trackers. Here we describe Track-A-Worm, a system rich in functionality, open in source code, and easy to use. The system includes plug-and-play hardware (a stereomicroscope, a digital camera and a motorized stage), custom software written to run with Matlab in Windows 7, and a detailed user manual. Grayscale images are automatically converted to binary images followed by head identification and placement of 13 markers along a deduced spline. The software can extract and quantify a variety of parameters, including distance traveled, average speed, distance/time/speed of forward and backward locomotion, frequency and amplitude of dominant bends, overall bending activities measured as root mean square, and sum of all bends. It also plots worm travel path, bend trace, and bend frequency spectrum. All functionality is performed through graphical user interfaces and data is exported to clearly-annotated and documented Excel files. These features make Track-A-Worm a good candidate for implementation in other labs. PMID:23922769

Development of a highly sensitive loop-mediated isothermal amplification (LAMP) method for the detection of Loa loa.

PubMed

Fernández-Soto, Pedro; Mvoulouga, Prosper Obolo; Akue, Jean Paul; Abán, Julio López; Santiago, Belén Vicente; Sánchez, Miguel Cordero; Muro, Antonio

2014-01-01

The filarial parasite Loa loa, the causative agent of loiasis, is endemic in Central and Western Africa infecting 3-13 million people. L. loa has been associated with fatal encephalopathic reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. In endemic areas, the only diagnostic method routinely used is the microscopic examination of mid-day blood samples by thick blood film. Improved methods for detection of L. loa are needed in endemic regions with limited resources, where delayed diagnosis results in high mortality. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid, inexpensive, molecular diagnosis of loiasis. Primers for LAMP were designed from a species-specific repetitive DNA sequence from L. loa retrieved from GenBank. Genomic DNA of a L. loa adult worm was used to optimize the LAMP conditions using a thermocycler or a conventional heating block. Amplification of DNA in the LAMP mixture was visually inspected for turbidity as well as addition of fluorescent dye. LAMP specificity was evaluated using DNA from other parasites; sensitivity was evaluated using DNA from L. loa 10-fold serially diluted. Simulated human blood samples spiked with DNA from L. loa were also tested for sensitivity. Upon addition of fluorescent dye, all positive reactions turned green while the negative controls remained orange under ambient light. After electrophoresis on agarose gels, a ladder of multiple bands of different sizes could be observed in positive samples. The detection limit of the assay was found to be as little as 0.5 ag of L. loa genomic DNA when using a heating block. We have designed, for the first time, a highly sensitive LAMP assay for the detection of L. loa which is potentially adaptable for field diagnosis and disease surveillance in loiasis-endemic areas.

Development of a Highly Sensitive Loop-Mediated Isothermal Amplification (LAMP) Method for the Detection of Loa loa

PubMed Central

Fernández-Soto, Pedro; Mvoulouga, Prosper Obolo; Akue, Jean Paul; Abán, Julio López; Santiago, Belén Vicente; Sánchez, Miguel Cordero; Muro, Antonio

2014-01-01

The filarial parasite Loa loa, the causative agent of loiasis, is endemic in Central and Western Africa infecting 3–13 million people. L. loa has been associated with fatal encephalopathic reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. In endemic areas, the only diagnostic method routinely used is the microscopic examination of mid-day blood samples by thick blood film. Improved methods for detection of L. loa are needed in endemic regions with limited resources, where delayed diagnosis results in high mortality. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid, inexpensive, molecular diagnosis of loiasis. Primers for LAMP were designed from a species-specific repetitive DNA sequence from L. loa retrieved from GenBank. Genomic DNA of a L. loa adult worm was used to optimize the LAMP conditions using a thermocycler or a conventional heating block. Amplification of DNA in the LAMP mixture was visually inspected for turbidity as well as addition of fluorescent dye. LAMP specificity was evaluated using DNA from other parasites; sensitivity was evaluated using DNA from L. loa 10-fold serially diluted. Simulated human blood samples spiked with DNA from L. loa were also tested for sensitivity. Upon addition of fluorescent dye, all positive reactions turned green while the negative controls remained orange under ambient light. After electrophoresis on agarose gels, a ladder of multiple bands of different sizes could be observed in positive samples. The detection limit of the assay was found to be as little as 0.5 ag of L. loa genomic DNA when using a heating block. We have designed, for the first time, a highly sensitive LAMP assay for the detection of L. loa which is potentially adaptable for field diagnosis and disease surveillance in loiasis-endemic areas. PMID:24722638

Choline incorporation by Schistosoma mansoni: distribution of choline metabolites during development and after sexual differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ancelin, M.L.; Torpier, G.; Vial, H.J.

1987-06-01

Choline metabolism was investigated in Schistosoma mansoni during the main phases of its development, namely, schistosomula, 11- and 15-day-old worms, and adults. At the physiological choline concentration used in the assay (20 microM), betaine was, along with phosphatidylcholine, one of the most abundant choline metabolites, revealing considerable choline oxidation activity. Very little radioactivity was associated with CDP-choline, whereas a sustained incorporation into phosphocholine occurred. These results provide good evidence that CTP:phosphocholine cytidylyltransferase plays a regulatory role in the de novo pathway of phosphatidylcholine biosynthesis. During development, the incorporation of choline into its various metabolites was maximal in 11-day-old worms. Atmore » this stage, the oxidative pathway predominated over the Kennedy pathway, whereas at all other stages the de novo phosphatidylcholine biosynthesis was predominant. Furthermore, choline incorporation into betaine was much more important in the adult female worm than in the male, indicating a major difference in choline incorporation and distribution between the 2 sexes of the adult worms.« less

Fourier transform infrared microspectroscopy for the analysis of the biochemical composition of C. elegans worms.

PubMed

Sheng, Ming; Gorzsás, András; Tuck, Simon

2016-01-01

Changes in intermediary metabolism have profound effects on many aspects of C. elegans biology including growth, development and behavior. However, many traditional biochemical techniques for analyzing chemical composition require relatively large amounts of starting material precluding the analysis of mutants that cannot be grown in large amounts as homozygotes. Here we describe a technique for detecting changes in the chemical compositions of C. elegans worms by Fourier transform infrared microspectroscopy. We demonstrate that the technique can be used to detect changes in the relative levels of carbohydrates, proteins and lipids in one and the same worm. We suggest that Fourier transform infrared microspectroscopy represents a useful addition to the arsenal of techniques for metabolic studies of C. elegans worms.

Eulimdana clava (Nematoda: Filarioidea) infection in domestic pigeons (Columba livia domestica): Molecular characterization and pathological changes.

PubMed

Šupić, Jovana; Alić, Alma Šeho; Hasanić, Melida; Goletić, Šejla; Duscher, Georg G; Hodžić, Adnan; Alić, Amer

2018-02-15

Filarial nematodes of the Eulimdana genus inhabit subcutaneous tissue of various avian species, mostly Charadriiforme birds. In domestic pigeons, E. clava is the only species recorded in the subcutaneous tissue in a number of isolated cases. In the present study, we discuss the morphology and histopathology of filarial nematodes recovered from subcutaneous tissue of domestic pigeons in Bosnia and Herzegovina. In total 110 pigeons were submitted to necropsy at the Department of Pathology of the Faculty of Veterinary Medicine in Sarajevo. At necropsy, in four pigeons (3.6%) numerous thread-like 0.9-2.1 cm long nematode parasites were observed in the subcutaneous tissue, peritracheal and periesophageal connective tissue. In one pigeon, the parasites were also found free in the body cavity around the heart and lungs. In addition, several 80-90 μm long microfilariae were noted in the tissue cross-sections. No significant lesions were observed associated with adult parasites or microfilariae. Based on morphology, host species and localization detected parasites were identified as E. clava. Molecular analyses of the cox1 and 12S rRNA nucleotide sequences herein generated revealed the close genetic relationship to other filarioid nematodes. The importance of the nematodes in pigeons and the lack of sequences in genetic databases for comparison of avian filarial parasites are emphasized. Copyright © 2018 Elsevier B.V. All rights reserved.

The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aitken, R.; Wilson, R.A.

1989-12-01

The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstratemore » that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response.« less

Neglected diseases and ethnic minorities in the Western Pacific Region exploring the links.

PubMed

Schratz, Alexander; Pineda, Martha Fernanda; Reforma, Liberty G; Fox, Nicole M; Le Anh, Tuan; Tommaso Cavalli-Sforza, L; Henderson, Mackenzie K; Mendoza, Raymond; Utzinger, Jürg; Ehrenberg, John P; Tee, Ah Sian

2010-01-01

Ethnic minority groups (EMGs) are often subject to exclusion, marginalization and poverty. These characteristics render them particularly vulnerable to neglected diseases, a diverse group of diseases that comprise bacteria, ecto-parasites, fungi, helminths and viruses. Despite the health policy relevance, only little is known of the epidemiological profile of neglected diseases among EMGs. We reviewed country data from Australia, Cambodia, Lao People's Democratic Republic, Malaysia, the Philippines and Vietnam and found several overlaps between regions with high proportions of EMG population and high prevalence rates of neglected diseases (infections with soil-transmitted helminths, filarial worms, schistosomes, food-borne trematodes and cestodes). While the links are not always clearly evident and it is impossible to establish correlations among highly aggregated data without control variables-such as environmental factors-there appear indeed to be important linkages between EMGs, socio-economic status and prevalence of neglected diseases. Some determinants under consideration are lack of access to health care and general health status, poverty and social marginalization, as well as education and literacy. Further research is needed to deepen the understanding of these linkages and to determine their public health and socio-economic significance. In particular, there is a need for more data from all countries in the Western Pacific Region that is disaggregated below the provincial level. Selected case studies that incorporate other control variables-such as risk factors from the physical environment-might be useful to inform policy makers about the feasibility of prevention and control interventions that are targeted at high-risk EMGs.

Testicular cytological profiles of apparently healthy male dromedary camels during rutting and non-rutting periods.

PubMed

Melaku, Simenew Keskes; Regassa, Fekadu; Tessema, Tesfaye Sisay; Kassa, Tesfu; Vencato, Juri; Owiny, David Okello; Stelletta, Calogero

2015-12-01

The aim of this study was to evaluate testicular cytological profiles of apparently healthy dromedary bulls during rutting and non-rutting periods. Pairs of testes from 26 (18 non-rutting and 8 rutting seasons) dromedary bulls 6-12 years old that were slaughtered at Akaki, Addis Ababa abattoir were sampled. A 21 gauge needle attached to 20mL syringe was used to collect Testicular Fine Needle Aspiration (TFNA) samples and five aspiration smears were prepared from each testis. A total of 312 slides (260 Testicular fine Needle Aspiration and 52 imprints) were examined. The mod ified May-Grunwald Giemsa (mMGG) technique and a light microscope were used to assess cellularity, morphology and quantification of the testicular. Sertoli and spermatogenic cells were identified and counted. The spermatic index (SI), Sertoli cell index (SEI) and the relationship between SI and SEI indexes (SSEI) were used to assess the ratio between mature spermatozoa and nursing cells. There were differences (P<0.05) between the rutting and non-rutting seasons among the spermatogenic and Sertoli cells. There were no differences between groups for primary spermatocyte numbers, early spermatid numbers and SSEI. There was no differences (P>0.05) between TFNA and imprint smear slides of the testicular cells except for Sertoli cell count and SEI. Filarial worm larvae were present on the TFNA smear slides of four animals. Imprint and TFNA smear slides had comparable cytological profiles in dromedary bulls and significant differences were observed between rutting and non-rutting periods. Copyright © 2015 Elsevier B.V. All rights reserved.

Hematozoa of forest birds in American Samoa - Evidence for a diverse, indigenous parasite fauna from the South Pacific

USGS Publications Warehouse

Atkinson, C.T.; Utzurrum, R.C.; Seamon, J.O.; Savage, Amy F.; Lapointe, D.A.

2006-01-01

Introduced avian diseases pose a significant threat to forest birds on isolated island archipelagos, especially where most passerines are endemic and many groups of blood-sucking arthropods are either absent or only recently introduced. We conducted a blood parasite survey of forest birds from the main islands of American Samoa to obtain baseline information about the identity, distribution and prevalence of hematozoan parasites in this island group. We examined Giemsa-stained blood smears from 857 individual birds representing 20 species on Tutuila, Ofu, Olosega, and Ta'u islands. Four hematozoan parasites were identified - Plasmodium circumflexum (1%, 12/857), Trypanosoma avium (4%, 32/857), microfilaria (9%, 76/857), and an Atoxoplasma sp. (<1%, 2/857). Infections were found in seven indigenous bird species from the archipelago. Overall prevalence of infection varied significantly among bird species, individual islands, and between Tutuila and the more isolated Manu'a group of islands. Infections with Plasmodium, Trypanosoma, and filarial worms occurred throughout the archipelago, including islands without introduced birds. There was a statistically significant difference in the overall prevalence of infection before and after Hurricane Olaf in February 2005, suggesting that catastrophic hurricanes may influence the dynamics of parasite infections. Given the central location of American Samoa in the South Pacific, it is likely that avian malaria and other hematozoan parasites are indigenous and widespread at least as far as the central South Pacific. Their natural occurrence may provide some immunological protection to indigenous birds in the event that other closely related parasites are accidentally introduced to the region.

Modelling variability in lymphatic filariasis: macrofilarial dynamics in the Brugia pahangi--cat model.

PubMed

Michael, E; Grenfell, B T; Isham, V S; Denham, D A; Bundy, D A

1998-01-22

A striking feature of lymphatic filariasis is the considerable heterogeneity in infection burden observed between hosts, which greatly complicates the analysis of the population dynamics of the disease. Here, we describe the first application of the moment closure equation approach to model the sources and the impact of this heterogeneity for macrofilarial population dynamics. The analysis is based on the closest laboratory equivalent of the life cycle and immunology of infection in humans--cats chronically infected with the filarial nematode Brugia pahangi. Two sets of long-term experiments are analysed: hosts given either single primary infections or given repeat infections. We begin by quantifying changes in the mean and aggregation of adult parasites (inversely measured by the negative binomial parameter, kappa in cohorts of hosts using generalized linear models. We then apply simple stochastic models to interpret observed patterns. The models and empirical data indicate that parasite aggregation tracks the decline in the mean burden with host age in primary infections. Conversely, in repeat infections, aggregation increases as the worm burden declines with experience of infection. The results show that the primary infection variability is consistent with heterogeneities in parasite survival between hosts. By contrast, the models indicate that the reduction in parasite variability with time in repeat infections is most likely due to the 'filtering' effect of a strong, acquired immune response, which gradually acts to remove the initial variability generated by heterogeneities in larval mortality. We discuss this result in terms of the homogenizing effect of host immunity-driven density-dependence on macrofilarial burden in older hosts.

Community assembly of the worm gut microbiome

NASA Astrophysics Data System (ADS)

Gore, Jeff

It has become increasingly clear that human health is strongly influenced by the bacteria that live within the gut, known collectively as the gut microbiome. This complex community varies tremendously between individuals, but understanding the sources that lead to this heterogeneity is challenging. To address this challenge, we are using a bottom-up approach to develop a predictive understanding of how the microbiome assembles and functions within a simple and experimentally tractable gut, the gut of the worm C. elegans. We have found that stochastic community assembly in the C. elegansintestine is sufficient to produce strong inter-worm heterogeneity in community composition. When worms are fed with two neutrally-competing fluorescently labeled bacterial strains, we observe stochastically-driven bimodality in community composition, where approximately half of the worms are dominated by each bacterial strain. A simple model incorporating stochastic colonization suggests that heterogeneity between worms is driven by the low rate at which bacteria successfully establish new intestinal colonies. We can increase this rate experimentally by feeding worms at high bacterial density; in these conditions the bimodality disappears. We have also characterized all pairwise interspecies competitions among a set of eleven bacterial species, illuminating the rules governing interspecies community assembly. These results demonstrate the potential importance of stochastic processes in bacterial community formation and suggest a role for C. elegans as a model system for ecology of host-associated communities.

In vitro antischistosomal activity of venom from the Egyptian snake Cerastes cerastes.

PubMed

Hassan, Ehssan Ahmed; Abdel-Rahman, Mohamed Ahmed; Ibrahim, Mohamed Moussa; Soliman, Maha Farid Mohamed

2016-01-01

We studied the potential in vitro antischistosomal activity of Cerastes cerastes venom on adult Schistosoma mansoni worms. Live specimens of the horned viper snake, C. cerastes were collected from the Aswan Governorate (Egypt). Venom was collected from snakes by manual milking. Worms of S. mansoni were obtained from infected hamsters by perfusion and isolated from blood using phosphate buffer. Mortality rates of worms were monitored after 3 days of exposure to snake venom at LC50 and various sublethal concentrations (10, 5, 2.5µg/ml). Scanning electron microscopy was used to investigate tegumental changes in treated worms after exposure to LC50 doses of venom. The LC50 of C. cerastes venom was 21.5µg/ml. The effect of C. cerastes venom on Schistosoma worms varied according to their sex. The mortality rate of male and female worms after 48-h exposure was 83.3% and 50%, respectively. LC50 of C. cerastes venom induced mild to severe tegumental damage in Schistosoma worms in the form of destruction of the oral sucker, shrinkage and erosion of the tegument, and loss of some tubercle spines. The present study demonstrated that C. cerastes venom exerts potential in vitro antischistosomal activity in a time and dose-dependent manner. These results may warrant further investigations to develop novel schistosomicidal agents from C. cerastes snake venom.

Impact of imidacloprid residues on the development of Eisenia fetida during vermicomposting of greenhouse plant waste.

PubMed

Fernández-Gómez, Manuel J; Romero, Esperanza; Nogales, Rogelio

2011-09-15

Pesticide application in agriculture causes residues in post-harvest plant waste at different concentrations. Knowledge concerning how pesticide concentrations in such waste affect earthworms is essential for recycling greenhouse plant debris through vermicomposting. Here, we have evaluated the effects of imidacloprid (IMD) residues on earthworms (Eisenia fetida) during the vermicomposting of plant waste from greenhouse crops in Spain. Before, the effect of different IMD concentrations on earthworms was tested using cattle manure as an optimum waste for worm development. The results after using cattle manure indicate that IMD dose ≥ 5 mg kg(-1) hinders worm growth and even causes death, whereas IMD dose ≤ 2 mg IMD kg(-1) allows worm growth similar to control but impedes reproduction. The results from the vermicomposting of plant waste reveal that IMD inhibits adequate worm growth and increases mortality. Although 89% worms became sexually mature in substrate containing 2 mg IMD kg(-1), they did not produce cocoons. IMD also affected microorganisms harboured in the substrates for vermicomposting, as indicated by the reduction in their dehydrogenase activity. This enzyme activity was restored after vermicomposting. This study provides a sound basis for the vermicomposting of pesticide-contaminated plant waste. Copyright © 2011 Elsevier B.V. All rights reserved.

Trends in high-throughput and functional neuroimaging in Caenorhabditis elegans.

PubMed

Cho, Yongmin; Zhao, Charles L; Lu, Hang

2017-05-01

The nervous system of Caenorhabditis elegans is an important model system for understanding the development and function of larger, more complex nervous systems. It is prized for its ease of handling, rapid life cycle, and stereotyped, well-cataloged development, with the development of all 302 neurons mapped all the way from zygote to adult. The combination of easy genetic manipulation and optical transparency of the worm allows for the direct imaging of its interior with fluorescent microscopy, without physically compromising the normal physiology of the animal itself. By expressing fluorescent markers, biologists study many developmental and cell biology questions in vivo; by expressing genetically encoded fluorescent calcium indicators within neurons, it is also possible to monitor their dynamic activity, answering questions about the structure and function of neural microcircuitry in the worm. However, to successfully image the worm it is necessary to overcome a number of experimental challenges. It is necessary to hold worms within the field of view, collect images efficiently and rapidly, and robustly analyze the data obtained. In recent years, a trend has developed toward imaging a large number of worms or neurons simultaneously, directly exploiting the unique properties of C. elegans to acquire data on a scale, which is not possible in other organisms. Doing this has required the development of new experimental tools, techniques, and data analytic approaches, all of which come together to open new perspectives on the field of neurobiology in C. elegans, and neuroscience in general. WIREs Syst Biol Med 2017, 9:e1376. doi: 10.1002/wsbm.1376 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

Computerized Design and Generation of Gear Drives With a Localized Bearing Contact and a Low Level of Transmission Errors

NASA Technical Reports Server (NTRS)

Litvin, F.; Chen, J.; Seol, I.; Kim, D.; Lu, J.; Zhao, X.; Handschuh, R.

1996-01-01

A general approach developed for the computerized simulation of loaded gear drives is presented. In this paper the methodology used to localize the bearing contact, provide a parabolic function of transmission errors, and simulate meshing and contact of unloaded gear drives is developed. The approach developed is applied to spur and helical gears, spiral bevel gears, face-gear drives, and worm-gear drives with cylindrical worms.

Lymphatic filariasis transmission risk map of India, based on a geo-environmental risk model.

PubMed

Sabesan, Shanmugavelu; Raju, Konuganti Hari Kishan; Subramanian, Swaminathan; Srivastava, Pradeep Kumar; Jambulingam, Purushothaman

2013-09-01

The strategy adopted by a global program to interrupt transmission of lymphatic filariasis (LF) is mass drug administration (MDA) using chemotherapy. India also followed this strategy by introducing MDA in the historically known endemic areas. All other areas, which remained unsurveyed, were presumed to be nonendemic and left without any intervention. Therefore, identification of LF transmission risk areas in the entire country has become essential so that they can be targeted for intervention. A geo-environmental risk model (GERM) developed earlier was used to create a filariasis transmission risk map for India. In this model, a Standardized Filariasis Transmission Risk Index (SFTRI, based on geo-environmental risk variables) was used as a predictor of transmission risk. The relationship between SFTRI and endemicity (historically known) of an area was quantified by logistic regression analysis. The quantified relationship was validated by assessing the filarial antigenemia status of children living in the unsurveyed areas through a ground truth study. A significant positive relationship was observed between SFTRI and the endemicity of an area. Overall, the model prediction of filarial endemic status of districts was found to be correct in 92.8% of the total observations. Thus, among the 190 districts hitherto unsurveyed, as many as 113 districts were predicted to be at risk, and the remaining at no risk. The GERM developed on geographic information system (GIS) platform is useful for LF spatial delimitation on a macrogeographic/regional scale. Furthermore, the risk map developed will be useful for the national LF elimination program by identifying areas at risk for intervention and for undertaking surveillance in no-risk areas.

Development and myogenesis of the vermiform Buddenbrockia (Myxozoa) and implications for cnidarian body plan evolution

PubMed Central

2012-01-01

Background The enigmatic wormlike parasite Buddenbrockia plumatellae has recently been shown to belong to the Myxozoa, which are now supported as a clade within Cnidaria. Most myxozoans are morphologically extremely simplified, lacking major metazoan features such as epithelial tissue layers, gut, nervous system, body axes and gonads. This hinders comparisons to free-living cnidarians and thus an understanding of myxozoan evolution and identification of their cnidarian sister group. However, B. plumatellae is less simplified than other myxozoans and therefore is of specific significance for such evolutionary considerations. Methods We analyse and describe the development of major body plan features in Buddenbrockia worms using a combination of histology, electron microscopy and confocal microscopy. Results Early developmental stages develop a primary body axis that shows a polarity, which is manifested as a gradient of tissue development, enabling distinction between the two worm tips. This polarity is maintained in adult worms, which, in addition, often develop a pore at the distal tip. The musculature comprises tetraradially arranged longitudinal muscle blocks consisting of independent myocytes embedded in the extracellular matrix between inner and outer epithelial tissue layers. The muscle fibres are obliquely oriented and in fully grown worms consistently form an angle of 12° with respect to the longitudinal axis of the worm in each muscle block and hence confer chirality. Connecting cells form a link between each muscle block and constitute four rows of cells that run in single file along the length of the worm. These connecting cells are remnants of the inner epithelial tissue layer and are anchored to the extracellular matrix. They are likely to have a biomechanical function. Conclusions The polarised primary body axis represents an ancient feature present in the last common ancestor of Cnidaria and Bilateria. The tetraradial arrangement of musculature is consistent with a medusozoan affinity for Myxozoa. However, the chiral pattern of muscle fibre orientation is apparently novel within Cnidaria and could thus be a specific adaptation. The presence of independent myocytes instead of Cnidaria-like epitheliomuscular cells can be interpreted as further support for the presence of mesoderm in cnidarians, or it may represent convergent evolution to a bilaterian condition. PMID:22594622

Adaptation of gastrointestinal nematode parasites to host genotype: single locus simulation models

PubMed Central

2013-01-01

Background Breeding livestock for improved resistance to disease is an increasingly important selection goal. However, the risk of pathogens adapting to livestock bred for improved disease resistance is difficult to quantify. Here, we explore the possibility of gastrointestinal worms adapting to sheep bred for low faecal worm egg count using computer simulation. Our model assumes sheep and worm genotypes interact at a single locus, such that the effect of an A allele in sheep is dependent on worm genotype, and the B allele in worms is favourable for parasitizing the A allele sheep but may increase mortality on pasture. We describe the requirements for adaptation and test if worm adaptation (1) is slowed by non-genetic features of worm infections and (2) can occur with little observable change in faecal worm egg count. Results Adaptation in worms was found to be primarily influenced by overall worm fitness, viz. the balance between the advantage of the B allele during the parasitic stage in sheep and its disadvantage on pasture. Genetic variation at the interacting locus in worms could be from de novo or segregating mutations, but de novo mutations are rare and segregating mutations are likely constrained to have (near) neutral effects on worm fitness. Most other aspects of the worm infection we modelled did not affect the outcomes. However, the host-controlled mechanism to reduce faecal worm egg count by lowering worm fecundity reduced the selection pressure on worms to adapt compared to other mechanisms, such as increasing worm mortality. Temporal changes in worm egg count were unreliable for detecting adaptation, despite the steady environment assumed in the simulations. Conclusions Adaptation of worms to sheep selected for low faecal worm egg count requires an allele segregating in worms that is favourable in animals with improved resistance but less favourable in other animals. Obtaining alleles with this specific property seems unlikely. With support from experimental data, we conclude that selection for low faecal worm egg count should be stable over a short time frame (e.g. 20 years). We are further exploring model outcomes with multiple loci and comparing outcomes to other control strategies. PMID:23714384

Filarial Infection or Antigen Administration Improves Glucose Tolerance in Diet-Induced Obese Mice.

PubMed

Berbudi, Afiat; Surendar, Jayagopi; Ajendra, Jesuthas; Gondorf, Fabian; Schmidt, David; Neumann, Anna-Lena; Wardani, Ajeng P F; Layland, Laura E; Hoffmann, Linda S; Pfeifer, Alexander; Hoerauf, Achim; Hübner, Marc P

2016-01-01

Helminths induce type 2 immune responses and establish an anti-inflammatory milieu in their hosts. This immunomodulation was previously shown to improve diet-induced insulin resistance which is linked to chronic inflammation. In the current study, we demonstrate that infection with the filarial nematode Litomosoides sigmodontis increased the eosinophil number and alternatively activated macrophage abundance within epididymal adipose tissue (EAT) and improved glucose tolerance in diet-induced obese mice in an eosinophil-dependent manner. L. sigmodontis antigen (LsAg) administration neither altered the body weight of animals nor adipose tissue mass or adipocyte size, but it triggered type 2 immune responses, eosinophils, alternatively activated macrophages, and type 2 innate lymphoid cells in EAT. Improvement in glucose tolerance by LsAg treatment remained even in the absence of Foxp3+ regulatory T cells. Furthermore, PCR array results revealed that LsAg treatment reduced inflammatory immune responses and increased the expression of genes related to insulin signaling (Glut4, Pde3b, Pik3r1, and Hk2) and fatty acid uptake (Fabp4 and Lpl). Our investigation demonstrates that L. sigmodontis infection and LsAg administration reduce diet-induced EAT inflammation and improve glucose tolerance. Helminth-derived products may, therefore, offer new options to improve insulin sensitivity, while loss of helminth infections in developing and developed countries may contribute to the recent increase in the prevalence of type 2 diabetes. © 2016 S. Karger AG, Basel.

Face Gear Drive With Helical Involute Pinion: Geometry, Generation by a Shaper and a Worm, Avoidance of Singularities and Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Fuentes, Alfonso; Gonzalez-Perez, Ignacio; Piscopo, Alessandro; Ruzziconi, Paolo

2005-01-01

A new type of face-gear drive with intersected axes of rotation formed by a helical involute pinion and conjugated face-gear has been investigated. Generation of face-gears by a shaper free of undercutting and pointing has been investigated. A new method of grinding or cutting of face-gears by a worm of special shape has been developed. A computerized design procedure has been developed to avoid undercutting and pointing by a shaper or by a generating worm. Also, a method to determine the limitations of the helix angle magnitude has been developed. The method provides a localization of the bearing contact to reduce the shift of bearing contact caused by misalignment. The analytical method provides a simulation of the meshing and contact of misaligned gear drives. An automatic mesh generation method has been developed and used to conduct a 3D contact stress analysis of several teeth. The theory developed is illustrated with several examples.

Podoconiosis - non-filarial geochemical elephantiasis - a neglected tropical disease?

PubMed

Nenoff, Pietro; Simon, Jan Christoph; Muylowa, Grace K; Davey, Gail

2010-01-01

Podoconiosis or mossy foot is a form of non-filarial lymphedema. This geochemical elephantiasis is a disabling condition caused by the passage of microparticles of silica and aluminum silicates through the skin of people walking barefoot in areas with a high content of soil of volcanic origin. Podoconiosis is widespread in tropical Africa, Central America and North India, yet it remains a neglected and under-researched condition. The disabling effects of podoconiosis cause great hardship to patients. It adversely affects the economic (reduced productivity and absenteeism), social (marriage, education, etc.) and psychological (social stigma) well-being of those affected. Podoconiosis can be prevented; the main primary preventive measure is protective footwear. Secondary measures include a strict hygiene regimen and compression therapy, which can reverse initial lesions. Tertiary approaches include surgical management, such as shaving operations to reduce hyperplastic and verrucous elephantiasis.

Calgranulin C Has Filariacidal and Filariastatic Activity

PubMed Central

Gottsch, John D.; Eisinger, Steven W.; Liu, Sammy H.; Scott, Alan L.

1999-01-01

The calgranulins are a family of calcium- and zinc-binding proteins produced by neutrophils, monocytes, and other cells. Calgranulins are released during inflammatory responses and have antimicrobial activity. Recently, one of the calgranulins, human calgranulin C (CaGC), has been implicated as an important component of the host responses that limit the parasite burden during filarial nematode infections. The goal of this work was to test the hypothesis that human CaGC has biologic activity against filarial parasites. Brugia malayi microfilariae and adults were exposed in vitro to 0.75 to 100 nM recombinant human CaGC. Recombinant CaGC affected adult and larval parasites in a dose-dependent fashion. Microfilariae were more sensitive to the action of CaGC than were adult parasites. At high levels, CaGC was both macrofilariacidal and microfilariacidal. At lower levels, the percentage of parasites killed was dependent on the level of CaGC in the culture system. The larvae not killed had limited motility. The filariastatic effect of low-level CaGC was reversed when the CaGC was removed from the culture system. Immunohistochemical analysis demonstrated that human CaGC accumulated in the cells of the hypodermis-lateral chord of adult and larval parasites. The antifilarial activity of CaGC was not due to the sequestration of zinc. Thus, the cellular and molecular mechanisms that result in the production and release of CaGC in humans may play a key role in the regulation of filarial parasite numbers. PMID:10569784

Identification of animal behavioral strategies by inverse reinforcement learning.

PubMed

Yamaguchi, Shoichiro; Naoki, Honda; Ikeda, Muneki; Tsukada, Yuki; Nakano, Shunji; Mori, Ikue; Ishii, Shin

2018-05-01

Animals are able to reach a desired state in an environment by controlling various behavioral patterns. Identification of the behavioral strategy used for this control is important for understanding animals' decision-making and is fundamental to dissect information processing done by the nervous system. However, methods for quantifying such behavioral strategies have not been fully established. In this study, we developed an inverse reinforcement-learning (IRL) framework to identify an animal's behavioral strategy from behavioral time-series data. We applied this framework to C. elegans thermotactic behavior; after cultivation at a constant temperature with or without food, fed worms prefer, while starved worms avoid the cultivation temperature on a thermal gradient. Our IRL approach revealed that the fed worms used both the absolute temperature and its temporal derivative and that their behavior involved two strategies: directed migration (DM) and isothermal migration (IM). With DM, worms efficiently reached specific temperatures, which explains their thermotactic behavior when fed. With IM, worms moved along a constant temperature, which reflects isothermal tracking, well-observed in previous studies. In contrast to fed animals, starved worms escaped the cultivation temperature using only the absolute, but not the temporal derivative of temperature. We also investigated the neural basis underlying these strategies, by applying our method to thermosensory neuron-deficient worms. Thus, our IRL-based approach is useful in identifying animal strategies from behavioral time-series data and could be applied to a wide range of behavioral studies, including decision-making, in other organisms.

Low virulence potential and in vivo transformation ability in the honey bee venom treated Clinostomum complanatum.

PubMed

Rehman, Abdur; Ullah, Rizwan; Jaiswal, Neeshma; Khan, M A Hannan; Rehman, Lubna; Beg, Mirza Ahmar; Malhotra, Sandeep K; Abidi, S M A

2017-12-01

The helminth parasites possess great capabilities to adapt themselves within their hosts and also develop strategies to render the commonly used anthelmintics ineffective leading to the development of resistance against these drugs. Besides using anthelmintics the natural products have also been tested for their anti-parasitic effects. Therapeutic efficacy of honey bee venom (HBV) has been tested in various ailments including some protozoal infections but very little is known about its anthelmintic properties. To investigate the anthelmintic effect of HBV the excysted progenetic metacercariae of Clinostomum complanatum, a heamophagic, digenetic trematode with zoonotic potential, infecting a wide variety of hosts, were obtained from Trichogaster fasciatus, a forage fish, which serves as the intermediate host. The metacercarial worms were in vitro incubated in RPMI-1640 medium containing HBV along with the controls which were devoid of HBV for the analysis of worm motility, enzyme activity, polypeptide profile and surface topographical changes. The motility of the worms was significantly reduced in a time dependent manner with an increase in the concentration of HBV. Following incubation of worms the release of cysteine proteases was inhibited in the presence of HBV as revealed by gelatine substrate gel zymography. As well as the polypeptide profile was also significantly influenced, particularly intensity/expression of M r 19.4 kDa, 24 kDa and 34 kDa was significantly reduced upon HBV treatment. The HBV treatment also inhibited antioxidant enzyme, superoxide dismutase (SOD) and Glutathione-S-transferase (GST) significantly (p < 0.05) in the worms. The scanning electron microscopy of the HBV treated worms revealed tegumental disruptions and erosion of papillae as well as spines showing vacuolation in the tegument. The HBV treated worms also showed a marked decline in the transformation rate when introduced into an experimental host which further reflect the anthelmintic potential of HBV. Copyright © 2017 Elsevier Inc. All rights reserved.

CD4 T Cells and Major Histocompatibility Complex Class II Expression Influence Worm Expulsion and Increased Intestinal Muscle Contraction during Trichinella spiralis Infection

PubMed Central

Vallance, Bruce A.; Galeazzi, Francesca; Collins, Stephen M.; Snider, Denis P.

1999-01-01

Expulsion of intestinal nematode parasites and the associated increased contraction by intestinal muscle are T cell dependent, since both are attenuated in athymic rodents. The CD4 T-cell subset has been strongly associated with worm expulsion; however, the relationship between these cells, antigen presentation, and worm expulsion is not definitive and the role of these factors in intestinal muscle hypercontractility has not been defined. We infected C57BL/6, athymic, CD4-deficient, CD8α-deficient, and major histocompatibility complex class II (MHC II)-deficient (C2d) mice with Trichinella spiralis larvae. We examined intestinal worm numbers, longitudinal muscle contraction, and MHC II expression. Numerous MHC II-positive cells were identified within the muscularis externa of infected but not uninfected C57BL/6 mice. C57BL/6 and CD8α-deficient mice developed large increases in muscle contraction, expelling the parasite by day 21. Athymic and C2d mice exhibited much smaller increases in muscle contraction and delayed parasite expulsion. CD4-deficient mice exhibited intermediate levels of muscle contraction and delayed parasite expulsion. To further examine the role of MHC II and CD4 T cells, we irradiated C2d mice and reconstituted them with C57BL/6 bone marrow alone or with C57BL/6 CD4 T cells. C57BL/6 bone marrow alone did not affect muscle function or worm expulsion in recipient C2d mice. Partial CD4 T-cell reconstitution was sufficient to restore increased muscle contraction but not worm expulsion. Thus, hematopoietic MHC II expression alone is insufficient for the development of muscle hypercontractility and worm expulsion, but the addition of even small numbers of CD4 T cells was sufficient to induce intestinal muscle pathophysiology. PMID:10531271

High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawai'i Island: A closer look at life cycle traits and patterns of infection in wild rats (Rattus spp.).

PubMed

Jarvi, Susan I; Quarta, Stefano; Jacquier, Steven; Howe, Kathleen; Bicakci, Deniz; Dasalla, Crystal; Lovesy, Noelle; Snook, Kirsten; McHugh, Robert; Niebuhr, Chris N

2017-01-01

The nematode Angiostrongylus cantonensis is a zoonotic pathogen and the etiological agent of human angiostrongyliasis or rat lungworm disease. Hawai'i, particularly east Hawai'i Island, is the epicenter for angiostrongyliasis in the USA. Rats (Rattus spp.) are the definitive hosts while gastropods are intermediate hosts. The main objective of this study was to collect adult A. cantonensis from wild rats to isolate protein for the development of a blood-based diagnostic, in the process we evaluated the prevalence of infection in wild rats. A total of 545 wild rats were sampled from multiple sites in the South Hilo District of east Hawai'i Island. Adult male and female A. cantonensis (3,148) were collected from the hearts and lungs of humanely euthanized Rattus rattus, and R. exulans. Photomicrography and documentation of multiple stages of this parasitic nematode in situ were recorded. A total of 45.5% (197/433) of rats inspected had lung lobe(s) (mostly upper right) which appeared granular indicating this lobe may serve as a filter for worm passage to the rest of the lung. Across Rattus spp., 72.7% (396/545) were infected with adult worms, but 93.9% (512/545) of the rats were positive for A. cantonensis infection based on presence of live adult worms, encysted adult worms, L3 larvae and/or by PCR analysis of brain tissue. In R. rattus we observed an inverse correlation with increased body mass and infection level of adult worms, and a direct correlation between body mass and encysted adult worms in the lung tissue, indicating that larger (older) rats may have developed a means of clearing infections or regulating the worm burden upon reinfection. The exceptionally high prevalence of A. cantonensis infection in Rattus spp. in east Hawai'i Island is cause for concern and indicates the potential for human infection with this emerging zoonosis is greater than previously thought.

Genetic analysis of Trichuris suis and Trichuris trichiura recovered from humans and pigs in a sympatric setting in Uganda.

PubMed

Nissen, Sofie; Al-Jubury, Azmi; Hansen, Tina V A; Olsen, Annette; Christensen, Henrik; Thamsborg, Stig M; Nejsum, Peter

2012-08-13

The whipworms Trichuris trichiura and Trichuris suis in humans and pigs, respectively, are believed to be two different species yet closely related. Morphologically, adult worms, eggs and larvae of the two species are indistinguishable. The aim of this study was to examine the genetic variation of Trichuris sp. mainly recovered from natural infected pigs and humans. Worm material isolated from humans and pigs living in the same geographical region in Uganda were analyzed by PCR, cloning and sequencing. Measurements of morphometric characters were also performed. The analysis of the ITS-2 (internal transcribed spacer) region showed a high genetic variation in the human-derived worms with two sequence types, designated type 1 and type 2, differing with up to 45%, the type 2 being identical to the sequence found in pig-derived worms. A single human-derived worm showed exclusively the type 2-genotype (T. suis-type) and three cases of 'heterozygote' worms in humans were identified. However, the analysis showed that sympatric Trichuris primarily assorted with host origin. Sequence analysis of a part of the genetically conserved β-tubulin gene confirmed two separate populations/species but also showed that the 'heterozygote' worms had a T. suis-like β-tubulin gene. A PCR-RFLP on the ITS-2 region was developed, that could distinguish between worms of the pig, human and 'heterozygote' type. The data suggest that Trichuris in pigs and humans belong to two different populations (i.e. are two different species). However, the data presented also suggest that cross-infections of humans with T. suis takes place. Further studies on sympatric Trichuris populations are highly warranted in order to explore transmission dynamics and unravel the zoonotic potential of T. suis. Copyright © 2012 Elsevier B.V. All rights reserved.

Expression of a unique drug-resistant Hsp90 ortholog by the nematode Caenorhabditis elegans.

PubMed

David, Cynthia L; Smith, Harold E; Raynes, Deborah A; Pulcini, Elizabeth J; Whitesell, Luke

2003-01-01

In all species studied to date, the function of heat shock protein 90 (Hsp90), a ubiquitous and evolutionarily conserved molecular chaperone, is inhibited selectively by the natural product drugs geldanamycin (GA) and radicicol. Crystal structures of the N-terminal region of yeast and human Hsp90 have revealed that these compounds interact with the chaperone in a Bergerat-type adenine nucleotide-binding fold shared throughout the gyrase, Hsp90, histidine kinase mutL (GHKL) superfamily of adenosine triphosphatases. To better understand the consequences of disrupting Hsp90 function in a genetically tractable multicellular organism, we exposed the soil-dwelling nematode Caenorhabditis elegans to GA under a variety of conditions designed to optimize drug uptake. Mutations in the gene encoding C elegans Hsp90 affect larval viability, dauer development, fertility, and life span. However, exposure of worms to GA produced no discernable phenotypes, although the amino acid sequence of worm Hsp90 is 85% homologous to that of human Hsp90. Consistent with this observation, we found that solid phase-immobilized GA failed to bind worm Hsp90 from worm protein extracts or when translated in a rabbit reticulocyte lysate system. Further, affinity precipitation studies using chimeric worm-vertebrate fusion proteins or worm C-terminal truncations expressed in reticulocyte lysate revealed that the conserved nucleotide-binding fold of worm Hsp90 exhibits the novel ability to bind adenosine triphosphate but not GA. Despite its unusual GA resistance, worm Hsp90 appeared fully functional when expressed in a vertebrate background. It heterodimerized with its vertebrate counterpart and showed no evidence of compromising its essential cellular functions. Heterologous expression of worm Hsp90 in tumor cells, however, did not render them GA resistant. These findings provide new insights into the nature of unusual N-terminal nucleotide-binding fold of Hsp90 and suggest that target-related drug resistance is unlikely to emerge in patients receiving GA-like chemotherapeutic agents.

Discrimination methods of biological contamination on fresh-cut lettuce based on VNIR and NIR hyperspectral imaging

USDA-ARS?s Scientific Manuscript database

Multispectral imaging algorithms were developed using visible-near-infrared (VNIR) and near-infrared (NIR) hyperspectral imaging (HSI) techniques to detect worms on fresh-cut lettuce. The optimal wavebands that detect worm on fresh-cut lettuce for each type of HSI were investigated using the one-way...

Effectiveness of copper oxide wire particles for Haemonchus contortus control in sheep.

PubMed

Knox, M R

2002-04-01

To assess the efficacy of copper oxide wire particles (COWP) for the control of H contortus infections in grazing sheep. In experiment 1, 40 worm-free Merino hoggets (11 to 12 months of age) were divided into four equal groups and allocated to separate 0.8 ha pasture plots. Two groups then received 2.5 g COWP whereas the other two groups were untreated. From 1 week after COWP treatment all lambs received a weekly infection of 2000 H contortus larvae. At week 8, six sheep from the untreated group were then allocated to two groups and treated with either 2.5 or 5.0 g of COWP to establish therapeutic efficacy of treatment. Experiment 2 followed a similar protocol but was conducted with 40 worm-free Merino lambs (3 to 4 months of age) and no assessment of therapeutic efficacy was made. In experiment 1 no significant difference in faecal worm egg counts was observed between treatments and faecal worm egg counts remained less than 3000 epg in all animals. Total worm counts were reduced by 37% by COWP treatment (P = 0.055). Both 2.5 g and 5.0 g doses of COWP at 8 weeks of infection reduced faecal worm egg counts by > 85% with the higher dose giving an earlier response to treatment. In experiment 2, faecal worm egg counts at 4 and 6 weeks were reduced by more than 90% in the COWP treated lambs and worm numbers were 54% lower after 6 weeks when all remaining untreated lambs had to be treated for haemonchosis. Mean faecal worm egg counts in the COWP lambs remained below 3500 epg and clinical disease did not develop in the majority of lambs before the end of the experiment at 10 weeks. Treatment with COWPs appears to have the potential to reduce establishment and worm fecundity of Haemonchus spp for an extended period and may offer livestock producers a supplementary means of reducing larval contamination of pasture particularly in areas where anthelmintic resistance is a problem and copper supplementation is likely to be beneficial.

A size threshold governs Caenorhabditis elegans developmental progression

PubMed Central

Uppaluri, Sravanti; Brangwynne, Clifford P.

2015-01-01

The growth of organisms from humans to bacteria is affected by environmental conditions. However, mechanisms governing growth and size control are not well understood, particularly in the context of changes in food availability in developing multicellular organisms. Here, we use a novel microfluidic platform to study the impact of diet on the growth and development of the nematode Caenorhabditis elegans. This device allows us to observe individual worms throughout larval development, quantify their growth as well as pinpoint the moulting transitions marking successive developmental stages. Under conditions of low food availability, worms grow very slowly, but do not moult until they have achieved a threshold size. The time spent in larval stages can be extended by over an order of magnitude, in agreement with a simple threshold size model. Thus, a critical worm size appears to trigger developmental progression, and may contribute to prolonged lifespan under dietary restriction. PMID:26290076

Parental effects on the larval performance of a tapeworm in its copepod first host.

PubMed

Benesh, D P

2013-08-01

Parents can influence the phenotype of their offspring through various mechanisms, besides the direct effect of heredity. Such parental effects are little explored in parasitic organisms, perhaps because in many parasites, per capita investment into offspring is low. I investigated whether parental identity, beyond direct genetic effects, could explain variation in the performance of the tapeworm Schistocephalus solidus in its first intermediate host, a copepod. I first determined that two breeding worms could be separated from one another after ~48 h of in vitro incubation and that the isolated worms continued producing outcrossed eggs, that is, rates self-fertilization did not increase after separation. Thus, from a breeding pair, two sets of genetically comparable eggs can be collected that have unambiguous parental identities. In an infection experiment, I found that the development of larval worms tended to vary between the two parental worms within breeding pairs, but infection success and growth rate in copepods did not. Accounting for this parental effect decreased the estimated heritability for development by nearly half. These results suggest that larval performance is not simply a function of a worm's genotype; who mothered or fathered an offspring can also affect offspring fitness, contradicting the perhaps naïve idea that parasites simply produce large quantities of uniformly low-quality offspring. © 2013 The Author. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Praziquantel decreases fecundity in Schistosoma mansoni adult worms that survive treatment: evidence from a laboratory life-history trade-offs selection study.

PubMed

Lamberton, Poppy H L; Faust, Christina L; Webster, Joanne P

2017-06-16

Mass drug administration of praziquantel is the World Health Organization's endorsed control strategy for schistosomiasis. A decade of annual treatments across sub-Saharan Africa has resulted in significant reductions of infection prevalence and intensity levels, although 'hotspots' remain. Repeated drug treatments place strong selective pressures on parasites, which may affect life-history traits that impact transmission dynamics. Understanding drug treatment responses and the evolution of such traits can help inform on how to minimise the risk of drug resistance developing, maximise sustainable control programme success, and improve diagnostic protocols. We performed a four-generation Schistosoma mansoni praziquantel selection experiment in mice and snails. We used three S. mansoni lines: a praziquantel-resistant isolate (R), a praziquantel-susceptible isolate (S), and a co-infected line (RS), under three treatment regimens: untreated, 25 mg/kg praziquantel, or 50 mg/kg praziquantel. Life-history traits, including parasite adult-worm establishment, survival, reproduction (fecundity), and associated morbidity, were recorded in mice across all four generations. Predictor variables were tested in a series of generalized linear mixed effects models to determine which factors had a significant influence on parasite life-history traits in definitive hosts under different selection regimes. Praziquantel pressure significantly reduced adult-worm burdens across all generations and isolates, including within R-lines. However, previous drug treatment resulted in an increase in adult-worm establishment with increasing generation from P1 to F3. The highest worm numbers were in the co-infected RS line. Praziquantel treatment decreased adult-worm burden, but had a larger negative impact on the mean daily number of miracidia, a proxy for fecundity, across all three parasite isolates. Our predicted cost of resistance was not supported by the traits we measured within the murine host. We did not find evidence for negative adult worm density-dependent effects on fecundity. In contrast, of the adult worms that survived treatment, even low doses of praziquantel significantly reduced adult-worm fecundity. Such reductions in worm fecundity post treatment suggest that egg - based measures of drug efficacy, such as Kato-Katz, may overestimate the short-term effect of praziquantel on adult - worm burdens. These findings have important implications for S. mansoni transmission control, diagnostic protocols, and the potential for undetected selection toward drug resistance.

The opportunistic transmission of wireless worms between mobile devices

NASA Astrophysics Data System (ADS)

Rhodes, C. J.; Nekovee, M.

2008-12-01

The ubiquity of portable wireless-enabled computing and communications devices has stimulated the emergence of malicious codes (wireless worms) that are capable of spreading between spatially proximal devices. The potential exists for worms to be opportunistically transmitted between devices as they move around, so human mobility patterns will have an impact on epidemic spread. The scenario we address in this paper is proximity attacks from fleetingly in-contact wireless devices with short-range communication range, such as Bluetooth-enabled smart phones. An individual-based model of mobile devices is introduced and the effect of population characteristics and device behaviour on the outbreak dynamics is investigated. The model uses straight-line motion to achieve population, though it is recognised that this is a highly simplified representation of human mobility patterns. We show that the contact rate can be derived from the underlying mobility model and, through extensive simulation, that mass-action epidemic models remain applicable to worm spreading in the low density regime studied here. The model gives useful analytical expressions against which more refined simulations of worm spread can be developed and tested.

The design and development of a spacecraft appendage tie down mechanism

NASA Technical Reports Server (NTRS)

Nygren, W. D.; Head, R.

1985-01-01

The design and evolution is described of a spacecraft Appendage Tie Down Mechanism (ATDM). Particular emphasis is paid to the mechanical aspects of using dry lubricants to increase the efficiency of acme threads and worm gearing. The ATDM consists of five major components. These are a dc torque motor, a worm gear speed reducer, the tension bolt (or T-bolt), nut capture and centering jaws and the capture nut. In addition, there are several minor components such as limit switch assemblies and an antibackdrive mechanism which couples the drive motor to the worm shaft. A development model of the ATDM in various configurations was under test for some time. In its latest version, it has successfully completed thermal vacuum testing, vibration testing, and extended life testing.

WormSizer: high-throughput analysis of nematode size and shape.

PubMed

Moore, Brad T; Jordan, James M; Baugh, L Ryan

2013-01-01

The fundamental phenotypes of growth rate, size and morphology are the result of complex interactions between genotype and environment. We developed a high-throughput software application, WormSizer, which computes size and shape of nematodes from brightfield images. Existing methods for estimating volume either coarsely model the nematode as a cylinder or assume the worm shape or opacity is invariant. Our estimate is more robust to changes in morphology or optical density as it only assumes radial symmetry. This open source software is written as a plugin for the well-known image-processing framework Fiji/ImageJ. It may therefore be extended easily. We evaluated the technical performance of this framework, and we used it to analyze growth and shape of several canonical Caenorhabditis elegans mutants in a developmental time series. We confirm quantitatively that a Dumpy (Dpy) mutant is short and fat and that a Long (Lon) mutant is long and thin. We show that daf-2 insulin-like receptor mutants are larger than wild-type upon hatching but grow slow, and WormSizer can distinguish dauer larvae from normal larvae. We also show that a Small (Sma) mutant is actually smaller than wild-type at all stages of larval development. WormSizer works with Uncoordinated (Unc) and Roller (Rol) mutants as well, indicating that it can be used with mutants despite behavioral phenotypes. We used our complete data set to perform a power analysis, giving users a sense of how many images are needed to detect different effect sizes. Our analysis confirms and extends on existing phenotypic characterization of well-characterized mutants, demonstrating the utility and robustness of WormSizer.

WormClassroom.org: An Inquiry-Rich Educational Web Portal for Research Resources of "Caenorhabditis elegans"

ERIC Educational Resources Information Center

Lu, Fong-Mei; Eliceiri, Kevin W.; Stewart, James; White, John G.

2007-01-01

The utilization of biology research resources, coupled with a "learning by inquiry" approach, has great potential to aid students in gaining an understanding of fundamental biological principles. To help realize this potential, we have developed a Web portal for undergraduate biology education, WormClassroom.org, based on current research…

A microfluidic device for automated, high-speed microinjection of Caenorhabditis elegans

PubMed Central

Song, Pengfei; Dong, Xianke; Liu, Xinyu

2016-01-01

The nematode worm Caenorhabditis elegans has been widely used as a model organism in biological studies because of its short and prolific life cycle, relatively simple body structure, significant genetic overlap with human, and facile/inexpensive cultivation. Microinjection, as an established and versatile tool for delivering liquid substances into cellular/organismal objects, plays an important role in C. elegans research. However, the conventional manual procedure of C. elegans microinjection is labor-intensive and time-consuming and thus hinders large-scale C. elegans studies involving microinjection of a large number of C. elegans on a daily basis. In this paper, we report a novel microfluidic device that enables, for the first time, fully automated, high-speed microinjection of C. elegans. The device is automatically regulated by on-chip pneumatic valves and allows rapid loading, immobilization, injection, and downstream sorting of single C. elegans. For demonstration, we performed microinjection experiments on 200 C. elegans worms and demonstrated an average injection speed of 6.6 worm/min (average worm handling time: 9.45 s/worm) and a success rate of 77.5% (post-sorting success rate: 100%), both much higher than the performance of manual operation (speed: 1 worm/4 min and success rate: 30%). We conducted typical viability tests on the injected C. elegans and confirmed that the automated injection system does not impose significant adverse effect on the physiological condition of the injected C. elegans. We believe that the developed microfluidic device holds great potential to become a useful tool for facilitating high-throughput, large-scale worm biology research. PMID:26958099

Of Mice, Cattle, and Humans: The Immunology and Treatment of River Blindness

PubMed Central

Allen, Judith E.; Adjei, Ohene; Bain, Odile; Hoerauf, Achim; Hoffmann, Wolfgang H.; Makepeace, Benjamin L.; Schulz-Key, Hartwig; Tanya, Vincent N.; Trees, Alexander J.; Wanji, Samuel; Taylor, David W.

2008-01-01

River blindness is a seriously debilitating disease caused by the filarial parasite Onchocerca volvulus, which infects millions in Africa as well as in South and Central America. Research has been hampered by a lack of good animal models, as the parasite can only develop fully in humans and some primates. This review highlights the development of two animal model systems that have allowed significant advances in recent years and hold promise for the future. Experimental findings with Litomosoides sigmodontis in mice and Onchocerca ochengi in cattle are placed in the context of how these models can advance our ability to control the human disease. PMID:18446236

Larvicidal, ovicidal and repellent activities of Cymbopogan citratus Stapf (Graminae) essential oil against the filarial mosquito Culex quinquefasciatus (Say) (Diptera : Culicidae).

PubMed

Pushpanathan, T; Jebanesan, A; Govindarajan, M

2006-12-01

Essential oils extracted by steam distillation from Cymbopogan citratus were evaluated for larvicidal, ovicidal and repellent activities against the filarial mosquito Culex quinquefasciatus. The larval mortality was observed after 24 hours treatment. The LC(50) values calculated for the 2nd, 3rd and 4th larval instar were 144.54 +/- 2.3, 165.70 +/- 1.2 and 184.18 +/- 0.8 ppm respectively. Hundred percent ovicidal activity was observed at 300 ppm. Skin repellent test at 1.0, 2.5 and 5.0 mg/cm(2) concentration of C. citratus gave 100% protection up to 3.00, 4.00 and 5.00 hours respectively. The total percentage of protection of this essential oil was 49.64% at 1.0 mg/cm(2), 62.19% at 2.5 mg/cm(2) and 74.03% at 5.0 mg/cm(2) for 12 hours.

Palaeosymbiosis Revealed by Genomic Fossils of Wolbachia in a Strongyloidean Nematode

PubMed Central

Koutsovoulos, Georgios; Makepeace, Benjamin; Tanya, Vincent N.; Blaxter, Mark

2014-01-01

Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections. PMID:24901418

Aedes albopictus and Culex pipiens implicated as natural vectors of Dirofilaria repens in central Italy.

PubMed

Cancrini, G; Scaramozzino, P; Gabrielli, S; Di Paolo, M; Toma, L; Romi, R

2007-11-01

To identify the natural vectors of Dirofilaria repens Railliet et Henry, entomological samplings were carried out in four sites within the Lazio region, foci of canine subcutaneous dirofilariasis. Collections were made in 2002-2003 by means of dog-baited and miniature Centers for Disease Control and Prevention traps as well as on humans. Microscopy identified 1576 attracted mosquito females as belonging to six species, but molecular diagnostics detected filarial DNA only in Culex pipiens L. and Aedes albopictus (Skuse, 1894). Dirofilaria immitis Leidy DNA, D. repens DNA, or both were found in the head and thorax of both mosquitoes. The simultaneous presence of vectors showing diurnal and nocturnal activity patterns is of concern for animal and human health. The finding of D. immitis DNA in mosquitoes in areas where only D. repens was been recovered in dogs also demonstrates that this filarial parasite circulates among carnivores (wild or domesticated pets).

Bacterial Microbiota Associated with the Glacier Ice Worm Is Dominated by Both Worm-Specific and Glacier-Derived Facultative Lineages

PubMed Central

Murakami, Takumi; Segawa, Takahiro; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2017-01-01

The community structure of bacteria associated with the glacier ice worm Mesenchytraeus solifugus was analyzed by amplicon sequencing of 16S rRNA genes and their transcripts. Ice worms were collected from two distinct glaciers in Alaska, Harding Icefield and Byron Glacier, and glacier surfaces were also sampled for comparison. Marked differences were observed in bacterial community structures between the ice worm and glacier surface samples. Several bacterial phylotypes were detected almost exclusively in the ice worms, and these bacteria were phylogenetically affiliated with either animal-associated lineages or, interestingly, clades mostly consisting of glacier-indigenous species. The former included bacteria that belong to Mollicutes, Chlamydiae, Rickettsiales, and Lachnospiraceae, while the latter included Arcicella and Herminiimonas phylotypes. Among these bacteria enriched in ice worm samples, Mollicutes, Arcicella, and Herminiimonas phylotypes were abundantly and consistently detected in the ice worm samples; these phylotypes constituted the core microbiota associated with the ice worm. A fluorescence in situ hybridization analysis showed that Arcicella cells specifically colonized the epidermis of the ice worms. Other bacterial phylotypes detected in the ice worm samples were also abundantly recovered from the respective habitat glaciers; these bacteria may be food for ice worms to digest or temporary residents. Nevertheless, some were overrepresented in the ice worm RNA samples; they may also function as facultative gut bacteria. Our results indicate that the community structure of bacteria associated with ice worms is distinct from that in the associated glacier and includes worm-specific and facultative, glacier-indigenous lineages. PMID:28302989

Bacterial Microbiota Associated with the Glacier Ice Worm Is Dominated by Both Worm-Specific and Glacier-Derived Facultative Lineages.

PubMed

Murakami, Takumi; Segawa, Takahiro; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2017-03-31

The community structure of bacteria associated with the glacier ice worm Mesenchytraeus solifugus was analyzed by amplicon sequencing of 16S rRNA genes and their transcripts. Ice worms were collected from two distinct glaciers in Alaska, Harding Icefield and Byron Glacier, and glacier surfaces were also sampled for comparison. Marked differences were observed in bacterial community structures between the ice worm and glacier surface samples. Several bacterial phylotypes were detected almost exclusively in the ice worms, and these bacteria were phylogenetically affiliated with either animal-associated lineages or, interestingly, clades mostly consisting of glacier-indigenous species. The former included bacteria that belong to Mollicutes, Chlamydiae, Rickettsiales, and Lachnospiraceae, while the latter included Arcicella and Herminiimonas phylotypes. Among these bacteria enriched in ice worm samples, Mollicutes, Arcicella, and Herminiimonas phylotypes were abundantly and consistently detected in the ice worm samples; these phylotypes constituted the core microbiota associated with the ice worm. A fluorescence in situ hybridization analysis showed that Arcicella cells specifically colonized the epidermis of the ice worms. Other bacterial phylotypes detected in the ice worm samples were also abundantly recovered from the respective habitat glaciers; these bacteria may be food for ice worms to digest or temporary residents. Nevertheless, some were overrepresented in the ice worm RNA samples; they may also function as facultative gut bacteria. Our results indicate that the community structure of bacteria associated with ice worms is distinct from that in the associated glacier and includes worm-specific and facultative, glacier-indigenous lineages.

Recovery, growth, and development of Acanthoparyphium tyosenense (Digenea: Echinostomatidae) in experimental chicks.

PubMed

Han, E T; Kim, J L; Chai, J Y

2003-02-01

Chicks were experimentally infected with Acanthoparyphium tyosenense (Digenea: Echinostomatidae) metacercariae per os, and the growth and development of worms in this host were observed from days I to 38 postinfection (PI). The worms grew rapidly and matured sexually in the small intestine (chiefly in the jejunum) of chicks by day 5 PI. and survived at least up to day 38 Pi, although worm recovery decreased after day 5 PI. Both parenchymal and reproductive organs increased greatly in size from day 2 to day 10 PI and then continued to increase gradually in size up to day 38 PI. The number of uterine eggs reached a peak on days 10 and 15 PI and then decreased gradually. The results suggest that chicks are a fairly suitable definitive host for experimental infection with A. tyosenense.

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region.

PubMed

Medeiros, Jansen Fernandes; Fontes, Gilberto; Nascimento, Vilma Lopes do; Rodrigues, Moreno; Cohen, Jacob; Andrade, Edmar Vaz de; Pessoa, Felipe Arley Costa; Martins, Marilaine

2018-03-01

The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI): 92.0 - 99.7] for PCR and 83.5% (95% CI: 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI: 93.7 - 100) for PCR and 98.3% (95% CI: 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears).

"Bird biting" mosquitoes and human disease: a review of the role of Culex pipiens complex mosquitoes in epidemiology.

PubMed

Farajollahi, Ary; Fonseca, Dina M; Kramer, Laura D; Marm Kilpatrick, A

2011-10-01

The transmission of vector-borne pathogens is greatly influenced by the ecology of their vector, which is in turn shaped by genetic ancestry, the environment, and the hosts that are fed on. One group of vectors, the mosquitoes in the Culex pipiens complex, play key roles in the transmission of a range of pathogens including several viruses such as West Nile and St. Louis encephalitis viruses, avian malaria (Plasmodium spp.), and filarial worms. The Cx. pipiens complex includes Culex pipiens pipiens with two forms, pipiens and molestus, Culex pipiens pallens, Culex quinquefasciatus, Culex australicus, and Culex globocoxitus. While several members of the complex have limited geographic distributions, Cx. pipienspipiens and Cx. quinquefasciatus are found in all known urban and sub-urban temperate and tropical regions, respectively, across the world, where they are often principal disease vectors. In addition, hybrids are common in areas of overlap. Although gaps in our knowledge still remain, the advent of genetic tools has greatly enhanced our understanding of the history of speciation, domestication, dispersal, and hybridization. We review the taxonomy, genetics, evolution, behavior, and ecology of members of the Cx. pipiens complex and their role in the transmission of medically important pathogens. The adaptation of Cx. pipiens complex mosquitoes to human-altered environments led to their global distribution through dispersal via humans and, combined with their mixed feeding patterns on birds and mammals (including humans), increased the transmission of several avian pathogens to humans. We highlight several unanswered questions that will increase our ability to control diseases transmitted by these mosquitoes. Copyright © 2011 Elsevier B.V. All rights reserved.

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region

PubMed Central

Medeiros, Jansen Fernandes; Fontes, Gilberto; do Nascimento, Vilma Lopes; Rodrigues, Moreno; Cohen, Jacob; de Andrade, Edmar Vaz; Pessoa, Felipe Arley Costa; Martins, Marilaine

2018-01-01

BACKGROUND The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. OBJECTIVES This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. METHODS Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. FINDINGS The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI): 92.0 - 99.7] for PCR and 83.5% (95% CI: 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI: 93.7 - 100) for PCR and 98.3% (95% CI: 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. MAIN CONCLUSIONS PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears). PMID:29412356

Impact of Six Rounds of Mass Drug Administration on Brugian Filariasis and Soil-Transmitted Helminth Infections in Eastern Indonesia

PubMed Central

Supali, Taniawati; Djuardi, Yenny; Bradley, Mark; Noordin, Rahmah; Rückert, Paul; Fischer, Peter U.

2013-01-01

Background The lymphatic filarial parasite Brugia timori occurs only in eastern Indonesia where it causes high morbidity. The absence of an animal reservoir, the inefficient transmission by Anopheles mosquitoes and the high sensitivity to DEC/albendazole treatment make this species a prime candidate for elimination by mass drug administration (MDA). Methodology/Principal Findings We evaluated the effect of MDA using DEC and albendazole on B. timori and soil transmitted helminths (STH) in a cross-sectional study of a sentinel village on Alor Island annually over a period of 10 years. Pre-MDA the microfilaria (MF) prevalence was 26% and 80% of the residents had filaria-specific IgG4 antibodies. In 2010, 34 months after the 6th round of MDA, MF and antibody rates were only 0.17% and 6.4%, respectively. The MDA campaign had also a beneficial effect on STH. Baseline prevalence rates for Ascaris, hookworm and Trichuris were 34%, 28%, and 11%, respectively; these rates were reduced to 27%, 4%, and 2% one year after the 5th round of MDA. Unfortunately, STH rates rebounded 34 months after cessation of MDA and approached pre-MDA rates. However, the intensity of STH infection in 2009 was still reduced, and no heavy infections were detected. Conclusions/Significance MDA with DEC/albendazole has had a major impact on B. timori MF and IgG4 antibody rates, providing a proof of principle that elimination is feasible. We also documented the value of annual DEC/albendazole as a mass de-worming intervention and the importance of continuing some form of STH control after cessation of MDA for filariasis. PMID:24349595

Impact of six rounds of mass drug administration on Brugian filariasis and soil-transmitted helminth infections in eastern Indonesia.

PubMed

Supali, Taniawati; Djuardi, Yenny; Bradley, Mark; Noordin, Rahmah; Rückert, Paul; Fischer, Peter U

2013-01-01

The lymphatic filarial parasite Brugia timori occurs only in eastern Indonesia where it causes high morbidity. The absence of an animal reservoir, the inefficient transmission by Anopheles mosquitoes and the high sensitivity to DEC/albendazole treatment make this species a prime candidate for elimination by mass drug administration (MDA). We evaluated the effect of MDA using DEC and albendazole on B. timori and soil transmitted helminths (STH) in a cross-sectional study of a sentinel village on Alor Island annually over a period of 10 years. Pre-MDA the microfilaria (MF) prevalence was 26% and 80% of the residents had filaria-specific IgG4 antibodies. In 2010, 34 months after the 6(th) round of MDA, MF and antibody rates were only 0.17% and 6.4%, respectively. The MDA campaign had also a beneficial effect on STH. Baseline prevalence rates for Ascaris, hookworm and Trichuris were 34%, 28%, and 11%, respectively; these rates were reduced to 27%, 4%, and 2% one year after the 5(th) round of MDA. Unfortunately, STH rates rebounded 34 months after cessation of MDA and approached pre-MDA rates. However, the intensity of STH infection in 2009 was still reduced, and no heavy infections were detected. MDA with DEC/albendazole has had a major impact on B. timori MF and IgG4 antibody rates, providing a proof of principle that elimination is feasible. We also documented the value of annual DEC/albendazole as a mass de-worming intervention and the importance of continuing some form of STH control after cessation of MDA for filariasis.

Bore holes and the vanishing of guinea worm disease in Ghana's upper region.

PubMed

Hunter, J M

1997-07-01

Ghana's Upper Region provides an excellent example of the beneficial effects of improved water security provided by hand-pump tube wells. Following a Ghana-Canada bilateral development project that installed some 2500 pumps, protection rates against guinea worm disease may be estimated as 88% in the west, and 96% in the east. Survey comparisons between ca 1960 and 1990 show that dracunculiasis declined in 32 of a total of 38 areas. The shadow of guinea worm has been lifted from the land and, in many areas, a true "vanishing" has occurred. The few areas of disease increase are characterized by the lowest population densities, pioneer settlement for cotton farming, and an absence of bore holes. Vagaries of development have inadvertently produced disease transformations or "metamorphoses" from dracunculiasis to elephantiasis (lymphatic filariasis) in one area, and to red water disease (schistosomiasis hematobium) in other areas. Correlative associations between pump densities and guinea worm disease are weakened by the large size of areas for which disease is reported in 1990. One preliminary finding is that geographical distance to the pump is a stronger influence than demographic pressure on pumps, regarding dracunculiasis. Diminishing returns on higher pump densities in many areas support the idea of making fuller, safer use of supplementary non-pump water. Despite crises of fee payment and pump maintenance, the rural bore hole project has struck a mortal blow against guinea worm, and permanently raised the quality of life in the Upper Region.

In vitro cultivation of Gymnophalloides seoi metacercariae (Digenea:Gymnophallidae).

PubMed

Kook, J; Lee, S H; Chai, J Y

1997-03-01

Gymnophalloides seoi is a human intestinal trematode prevalent on southwestern islands in Korea. In the present study, we investigated whether G. seoi metacercariae can grow and develop into adults by in vitro cultivation. The metacercariae were obtained from naturally infected oysters, and cultured in vitro for 5 days under three conditions; 37 degrees C/5% CO2, 41 degrees C/8% CO2, or 41 degrees C/5% CO2, in NCTC 109 complete media containing 20% FBS and 1% antibiotics-antimycotics. The degree of worm growth and development was compared with that grown in vivo of C3H mice. The length of the worms cultivated in vitro was 200-300 microns not significantly different from metacercariae, whereas the length of the worms recovered from C3H mice was significantly larger, 300-400 microns. The worms produced eggs when grown in C3H mice or cultured in vitro for 2 days under 41 degrees C/8% CO2 or 41 degrees C/5% CO2, but not when cultured under 37 degrees C/5% CO2. Among the in vitro conditions, 41 degrees C/5% CO2 was best for egg production, although the number of eggs was about half of worms obtained from C3H mice. In conclusion, in vitro cultivation of G. seoi metacercariae into egg-producing adults was partially successful under culture conditions of 41 degrees C/5% CO2 or 41 degrees C/8% CO2.

Comparison of worm development and host immune responses in natural hosts of schistosoma japonicum, yellow cattle and water buffalo

PubMed Central

2012-01-01

Background Yellow cattle and water buffalo are two of the most important natural hosts for Schistosoma japonicum in China. Previous observation has revealed that yellow cattle are more suited to the development of S. japonicum than water buffalo. Understanding more about the molecular mechanisms involved in worm development, as well as the pathological and immunological differences between yellow cattle and water buffalo post infection with S japonicum will provide useful information for the vaccine design and its delivery procedure. Results The worm length (p < 0.01), worm recovery rate (p < 0.01) and the percentage of paired worms (p < 0.01) were significantly greater in yellow cattle than those in water buffalo. There were many white egg granulomas in the livers of yellow cattle, but fewer were observed in water buffalo at 7 weeks post infection. The livers of infected yellow cattle contained significantly increased accumulation of inflammatory cells, and the schistosome eggs were surrounded with large amounts of eosinophil infiltration. In contrast, no hepatocyte swelling or lymphocyte infiltration, and fewer white blood cells, was observed in water buffalo. The percentage of CD4+ T cells was higher in yellow cattle, while the percentage of CD8+ T cells was higher in water buffalo from pre-infection to 7 w post infection. The CD4/CD8 ratios were decreased in both species after challenge with schistosomes. Comparing with water buffalo, the IFN-γ level was higher and decreased significantly, while the IL-4 level was lower and increased gradually in yellow cattle from pre-infection to 7 w post infection. Conclusions In this study, we confirmed that yellow cattle were more suited to the development of S. japonicum than water buffalo, and more serious pathological damage was observed in infected yellow cattle. Immunological analysis suggested that CD4+ T cells might be an integral component of the immune response and might associate with worm development in yellow cattle. A shift from Th1 to Th2 type polarized immunity was only shown clearly in schistosome-infected yellow cattle, but no shift in water buffalo. The results provide valuable information for increased understanding of host-schistosome interactions, and for control of schistosomiasis. PMID:22414188

CD4+CD25hiFOXP3+ cells in cord blood of neonates born from filaria infected mother are negatively associated with CD4+Tbet+ and CD4+RORγt+ T cells.

PubMed

Ateba-Ngoa, Ulysse; Mombo-Ngoma, Ghyslain; Zettlmeissl, Eva; van der Vlugt, Luciën E P M; de Jong, Sanne E; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

2014-01-01

Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC) were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = -0.242, P = 0.002; B = -0.178, P = 0.013 respectively). Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check.

Global Coordination and Standardisation in Marine Biodiversity through the World Register of Marine Species (WoRMS) and Related Databases

PubMed Central

Bouchet, Philippe; Boxshall, Geoff; Fauchald, Kristian; Gordon, Dennis; Hoeksema, Bert W.; Poore, Gary C. B.; van Soest, Rob W. M.; Stöhr, Sabine; Walter, T. Chad; Vanhoorne, Bart; Decock, Wim

2013-01-01

The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species. Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management. By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management. PMID:23505408

Global coordination and standardisation in marine biodiversity through the World Register of Marine Species (WoRMS) and related databases.

PubMed

Costello, Mark J; Bouchet, Philippe; Boxshall, Geoff; Fauchald, Kristian; Gordon, Dennis; Hoeksema, Bert W; Poore, Gary C B; van Soest, Rob W M; Stöhr, Sabine; Walter, T Chad; Vanhoorne, Bart; Decock, Wim; Appeltans, Ward

2013-01-01

The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species. Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management. By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management.

21 CFR 520.905a - Fenbendazole suspension.

Code of Federal Regulations, 2013 CFR

2013-04-01

... worms (adults and 4th-stage larvae)—barberpole worm (Haemonchus contortus and H. placei) and small stomach worm (Trichostongylus axei); intestinal worms (adults and 4th-stage larvae)—hookworm (Bunostonmum... control of stomach worm (4th stage inhibited larvae/type II ostertagiasis), Ostertagia ostertagi, and...

21 CFR 520.905a - Fenbendazole suspension.

Code of Federal Regulations, 2014 CFR

2014-04-01

... worms (adults and 4th-stage larvae)—barberpole worm (Haemonchus contortus and H. placei) and small stomach worm (Trichostongylus axei); intestinal worms (adults and 4th-stage larvae)—hookworm (Bunostonmum... control of stomach worm (4th stage inhibited larvae/type II ostertagiasis), Ostertagia ostertagi, and...

High prevalence of Angiostrongylus cantonensis (rat lungworm) on eastern Hawai‘i Island: A closer look at life cycle traits and patterns of infection in wild rats (Rattus spp.)

PubMed Central

Quarta, Stefano; Jacquier, Steven; Howe, Kathleen; Bicakci, Deniz; Dasalla, Crystal; Lovesy, Noelle; Snook, Kirsten; McHugh, Robert; Niebuhr, Chris N.

2017-01-01

The nematode Angiostrongylus cantonensis is a zoonotic pathogen and the etiological agent of human angiostrongyliasis or rat lungworm disease. Hawai‘i, particularly east Hawai‘i Island, is the epicenter for angiostrongyliasis in the USA. Rats (Rattus spp.) are the definitive hosts while gastropods are intermediate hosts. The main objective of this study was to collect adult A. cantonensis from wild rats to isolate protein for the development of a blood-based diagnostic, in the process we evaluated the prevalence of infection in wild rats. A total of 545 wild rats were sampled from multiple sites in the South Hilo District of east Hawai‘i Island. Adult male and female A. cantonensis (3,148) were collected from the hearts and lungs of humanely euthanized Rattus rattus, and R. exulans. Photomicrography and documentation of multiple stages of this parasitic nematode in situ were recorded. A total of 45.5% (197/433) of rats inspected had lung lobe(s) (mostly upper right) which appeared granular indicating this lobe may serve as a filter for worm passage to the rest of the lung. Across Rattus spp., 72.7% (396/545) were infected with adult worms, but 93.9% (512/545) of the rats were positive for A. cantonensis infection based on presence of live adult worms, encysted adult worms, L3 larvae and/or by PCR analysis of brain tissue. In R. rattus we observed an inverse correlation with increased body mass and infection level of adult worms, and a direct correlation between body mass and encysted adult worms in the lung tissue, indicating that larger (older) rats may have developed a means of clearing infections or regulating the worm burden upon reinfection. The exceptionally high prevalence of A. cantonensis infection in Rattus spp. in east Hawai‘i Island is cause for concern and indicates the potential for human infection with this emerging zoonosis is greater than previously thought. PMID:29252992

Cutaneous Emergence of Eustrongylides in Two Persons from South Sudan

PubMed Central

Eberhard, Mark L.; Ruiz-Tiben, Ernesto

2014-01-01

Two large, living worms were collected as they emerged from the lower limb of each of two persons in South Sudan. The worms were observed by staff of the South Sudan Guinea Worm Eradication Program during surveillance activities in communities at-risk for cases of Guinea worm disease (dracunculiasis). The worms measured 7 and 8 cm in length and were identified as fourth-stage larvae of Eustrongylides. This is the first report of such worms emerging from the skin; all five previous reports of human infection involved surgical removal of worms from the peritoneal cavity. PMID:24379241

Can Parasitic Worms Cure the Modern World's Ills?

PubMed

Harnett, Margaret M; Harnett, William

2017-09-01

There has been increasing recognition that the alarming surge in allergy and autoimmunity in the industrialised and developing worlds shadows the rapid eradication of pathogens, such as parasitic helminths. Appreciation of this has fuelled an explosion in research investigating the therapeutic potential of these worms. This review considers the current state-of-play with a particular focus on exciting recent advances in the identification of potential novel targets for immunomodulation that can be exploited therapeutically. Furthermore, we contemplate the prospects for designing worm-derived immunotherapies for an ever-widening range of inflammatory diseases, including, for example, obesity, cardiovascular disease, and ageing as well as neurodevelopmental disorders like autism. Copyright © 2017 Elsevier Ltd. All rights reserved.

EFFECT OF X-RAYS ON THE DEVELOPMENT OF THE INFECTIVE LARVAE OF OESOPHAGOSTOMUM RADIATUM (RUD. 1803) (STRONGYLIDAE: NEMATODA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riek, R.F.; Keith, R.K.

1960-06-18

Calves reared worm-free were given either normal infective larvae or irradiated larvae of Oesophagostomum radiatum. These helminths often cause gastrointestinal infestation in cattle. The irradiated larvae were exposed to 20,000 r of x radiation. Calves from the group given irradiated larvae were killed aad examined for worms 3, 4, 5, 6, and 8 weeks after infestation. A calf from the control group was killed 6 weeks after infestation. Results from examinations for worms are tabulated. The main effect of this level of radiation was to prevent the establishment of an adult male population in norrnal numbers. Findings are discussed. (C.H.)

Quantitative Assessment of Fat Levels in Caenorhabditis elegans Using Dark Field Microscopy

PubMed Central

Fouad, Anthony D.; Pu, Shelley H.; Teng, Shelly; Mark, Julian R.; Fu, Moyu; Zhang, Kevin; Huang, Jonathan; Raizen, David M.; Fang-Yen, Christopher

2017-01-01

The roundworm Caenorhabditis elegans is widely used as a model for studying conserved pathways for fat storage, aging, and metabolism. The most broadly used methods for imaging fat in C. elegans require fixing and staining the animal. Here, we show that dark field images acquired through an ordinary light microscope can be used to estimate fat levels in worms. We define a metric based on the amount of light scattered per area, and show that this light scattering metric is strongly correlated with worm fat levels as measured by Oil Red O (ORO) staining across a wide variety of genetic backgrounds and feeding conditions. Dark field imaging requires no exogenous agents or chemical fixation, making it compatible with live worm imaging. Using our method, we track fat storage with high temporal resolution in developing larvae, and show that fat storage in the intestine increases in at least one burst during development. PMID:28404661

Microfluidic platform integrated with worm-counting setup for assessing manganese toxicity

PubMed Central

Zhang, Beibei; Li, Yinbao; He, Qidi; Qin, Jun; Yu, Yanyan; Li, Xinchun; Zhang, Lin; Yao, Meicun; Liu, Junshan; Chen, Zuanguang

2014-01-01

We reported a new microfluidic system integrated with worm responders for evaluating the environmental manganese toxicity. The micro device consists of worm loading units, worm observing chambers, and a radial concentration gradient generator (CGG). Eight T-shape worm loading units of the micro device were used to load the exact number of worms into the corresponding eight chambers with the assistance of worm responders and doorsills. The worm responder, as a key component, was employed for performing automated worm-counting assay through electric impedance sensing. This label-free and non-invasive worm-counting technique was applied to the microsystem for the first time. In addition, the disk-shaped CGG can generate a range of stepwise concentrations of the appointed chemical automatically and simultaneously. Due to the scalable architecture of radial CGG, it has the potential to increase the throughput of the assay. Dopaminergic (DAergic) neurotoxicity of manganese on C. elegans was quantitatively assessed via the observation of green fluorescence protein-tagged DAergic neurons of the strain BZ555 on-chip. In addition, oxidative stress triggered by manganese was evaluated by the quantitative fluorescence intensity of the strain CL2166. By scoring the survival ratio and stroke frequency of worms, we characterized the dose- and time-dependent mobility defects of the manganese-exposed worms. Furthermore, we applied the microsystem to investigate the effect of natural antioxidants to protect manganese-induced toxicity. PMID:25538805

Pyrosequencing of prey DNA in reptile faeces: analysis of earthworm consumption by slow worms.

PubMed

Brown, David S; Jarman, Simon N; Symondson, William O C

2012-03-01

Little quantitative ecological information exists on the diets of most invertebrate feeding reptiles, particularly nocturnal or elusive species that are difficult to observe. In the UK and elsewhere, reptiles are legally required to be relocated before land development can proceed, but without knowledge of their dietary requirements, the suitability of receptor sites cannot be known. Here, we tested the ability of non-invasive DNA-based molecular diagnostics (454 pyrosequencing) to analyse reptile diets, with the specific aims of determining which earthworm species are exploited by slow worms (the legless lizard Anguis fragilis) and whether they feed on the deeper-living earthworm species that only come to the surface at night. Slow worm faecal samples from four different habitats were analysed using earthworm-specific PCR primers. We found that 86% of slow worms (N=80) had eaten earthworms. In lowland heath and marshy/acid grassland, Lumbricus rubellus, a surface-dwelling epigeic species, dominated slow worm diet. In two other habitats, riverside pasture and calciferous coarse grassland, diet was dominated by deeper-living anecic and endogeic species. We conclude that all species of earthworm are exploited by these reptiles and lack of specialization allows slow worms to thrive in a wide variety of habitats. Pyrosequencing of prey DNA in faeces showed promise as a practical, rapid and relatively inexpensive means of obtaining detailed and valuable ecological information on the diets of reptiles. © 2011 Blackwell Publishing Ltd.

Identification by machine vision of the rate of motor activity decline as a lifespan predictor in C. elegans

PubMed Central

Hsu, Ao-Lin; Feng, Zhaoyang; Hsieh, Meng-Yin; Xu, X. Z. Shawn

2009-01-01

One challenge in aging research concerns identifying physiological parameters or biomarkers that can reflect the physical health of an animal and predict its lifespan. In C. elegans, a model organism widely used in aging research, motor deficits develop in old worms. Here we employed machine vision to quantify worm locomotion behavior throughout lifespan. We confirm that aging worms undergo a progressive decline in motor activity, beginning in early life. Importantly, the rate of motor activity decline rather than the absolute motor activity in the early-to-mid life of individual worms in an isogenic population inversely correlates with their lifespan, and thus may serve as a lifespan predictor. Long-lived mutant strains with deficits in insulin/IGF-1 signaling or food intake display a reduction in the rate of motor activity decline, suggesting that this parameter might also be used for across-strain comparison of healthspan. Our work identifies an endogenous physiological parameter for lifespan prediction and healthspan comparison. PMID:18255194

Identification by machine vision of the rate of motor activity decline as a lifespan predictor in C. elegans.

PubMed

Hsu, Ao-Lin; Feng, Zhaoyang; Hsieh, Meng-Yin; Xu, X Z Shawn

2009-09-01

One challenge in aging research concerns identifying physiological parameters or biomarkers that can reflect the physical health of an animal and predict its lifespan. In C. elegans, a model organism widely used in aging research, motor deficits develop in old worms. Here we employed machine vision to quantify worm locomotion behavior throughout lifespan. We confirm that aging worms undergo a progressive decline in motor activity, beginning in early life. Importantly, the rate of motor activity decline rather than the absolute motor activity in the early-to-mid life of individual worms in an isogenic population inversely correlates with their lifespan, and thus may serve as a lifespan predictor. Long-lived mutant strains with deficits in insulin/IGF-1 signaling or food intake display a reduction in the rate of motor activity decline, suggesting that this parameter might also be used for across-strain comparison of healthspan. Our work identifies an endogenous physiological parameter for lifespan prediction and healthspan comparison.

The Father Christmas worm

NASA Technical Reports Server (NTRS)

Green, James L.; Sisson, Patricia L.

1989-01-01

Given here is an overview analysis of the Father Christmas Worm, a computer worm that was released onto the DECnet Internet three days before Christmas 1988. The purpose behind the worm was to send an electronic mail message to all users on the computer system running the worm. The message was a Christmas greeting and was signed 'Father Christmas'. From the investigation, it was determined that the worm was released from a computer (node number 20597::) at a university in Switzerland. The worm was designed to travel quickly. Estimates are that it was copied to over 6,000 computer nodes. However, it was believed to have executed on only a fraction of those computers. Within ten minutes after it was released, the worm was detected at the Space Physics Analysis Network (SPAN), NASA's largest space and Earth science network. Once the source program was captured, a procedural cure, using the existing functionality of the computer operating systems, was quickly devised and distributed. A combination of existing computer security measures, the quick and accurate procedures devised to stop copies of the worm from executing, and the network itself, were used to rapidly provide the cure. These were the main reasons why the worm executed on such a small percentage of nodes. This overview of the analysis of the events concerning the worm is based on an investigation made by the SPAN Security Team and provides some insight into future security measures that will be taken to handle computer worms and viruses that may hit similar networks.

Design and analysis of SEIQR worm propagation model in mobile internet

NASA Astrophysics Data System (ADS)

Xiao, Xi; Fu, Peng; Dou, Changsheng; Li, Qing; Hu, Guangwu; Xia, Shutao

2017-02-01

The mobile Internet has considerably facilitated daily life in recent years. However, it has become the breeding ground for lots of new worms, including the Bluetooth-based worm, the SMS/MMS-based worm and the Wi-Fi-based worm. At present, Wi-Fi is widely used for mobile devices to connect to the Internet. But it exposes these devices to the dangerous environment. Most current worm propagation models aim to solve the problems of computer worms. They cannot be used directly in the mobile environment, particularly in the Wi-Fi scenario, because of the differences between computers and mobile devices. In this paper, we propose a worm propagation model in the Wi-Fi environment, called SEIQR (Susceptible-Exposed-Infectious- Quarantined-Recovered). In the model, infected nodes can be quarantined by the Wi-Fi base station, and a new state named the Quarantined state (Q) is established to represent these infected nodes. Based on this model, we present an effective method to inhibit the spread of the Wi-Fi-based worms. Furthermore, related stabilities of the worm-free and endemic equilibriums are studied based on the basic reproduction number R0. The worm-free equilibrium is locally and globally asymptotically stable if R0 < 1, whereas the endemic equilibrium is locally asymptotically stable if R0 < 1. Finally, we evaluate the performance of our model by comprehensive experiments with different infection rates and quarantine rates. The results indicate that our mechanism can combat the worms propagated via Wi-Fi.

Towards global Guinea worm eradication in 2015: the experience of South Sudan.

PubMed

Awofeso, Niyi

2013-08-01

For centuries, the Guinea worm parasite (Dracunculus medinensis) has caused disabling misery, infecting people who drink stagnant water contaminated with the worm's larvae. In 2012, there were 542 cases of Guinea worm reported globally, of which 521 (96.1%) were reported in South Sudan. Protracted civil wars, an inadequate workforce, neglect of potable water provision programs, suboptimal Guinea worm surveillance and case containment, and fragmented health systems account for many of the structural and operational factors encumbering South Sudan's Guinea worm eradication efforts. This article reviews the impacts of six established Guinea worm control strategies in South Sudan: (1) surveillance to determine actual caseload distribution and trends in response to control measures; (2) educating community members from whom worms are emerging to avoid immersing affected parts in sources of drinking water; (3) filtering potentially contaminated drinking water using cloth filters or filtered drinking straws; (4) treating potentially contaminated surface water with the copepod larvicide temephos (Abate); (5) providing safe drinking water from boreholes or hand-dug wells; and (6) containment of transmission through voluntary isolation of each patient to prevent contamination of drinking water sources, provision of first aid, and manual extraction of the worm. Surveillance, community education, potable water provision, and case containment remain weak facets of the program. Abate pesticide is not a viable option for Guinea worm control in South Sudan. In light of current case detection and containment trends, as well as capacity building efforts for Guinea worm eradication, South Sudan is more likely to eradicate Guinea worm by 2020, rather than by 2015. The author highlights areas in which substantial improvements are required in South Sudan's Guinea worm eradication program, and suggests improvement strategies. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Cadmium resistance in an oligochaete and its effect on cadmium trophic transfer to an omnivorous shrimp

USGS Publications Warehouse

Wallace, W.G.; Lopez, G.R.; Levinton, J.S.

1998-01-01

It has been demonstrated that the deposit-feeding oligochaete Limnodrilus hoffmeisteri inhabiting Foundry Cove (FC), a severely cadmium (Cd)-contaminated cove located on the Hudson River, New York, USA, has evolved resistance to Cd. In this study we investigate how this resistance influences Cd trophic transfer from this oligochaete to the grass shrimp Palaemonetes pugio. Cadmium-resistant worms collected from FC and nonresistant worms collected from an adjacent unpolluted site were investigated for differences in Cd tolerance, accumulation, subcellular distribution and bioavailability to shrimp. FC worms were more tolerant of Cd, surviving twice as long as worms from the unpolluted site during a toxicity bioassay. The 7 d concentration factor of Cd-resistant worms was 4 times greater than that of nonresistant worms (2020 vs 577). There were also differences between worm populations with respect to subcellular Cd distributions. Cd-resistant worms produced metallothionein-like proteins (MT) as well as metal-rich granules (MRG) for Cd storage and detoxification; nonresistant worms only produced MT. These differences in subcellular Cd distributions led to large differences in Cd bioavailability to shrimp; shrimp fed Cd-resistant worms absorbed 21% of the ingested Cd, while those fed nonresistant worms absorbed roughly 4 times that amount (~75%). These absorption efficiencies were in good agreement with the proportions of Cd bound to the worm's most biologically available subcellular fractions (i.e. the cytosol and organelles). Although Cd-resistant worms predominantly stored the toxic metal in biologically unavailable MRG, their increased accumulation of Cd would still result in substantial trophic transfer to shrimp because of the storage of Cd in the biologically available fractions. This work demonstrates that the evolution of Cd resistance can have profound implications for Cd bioavailability and cycling within aquatic ecosystems.

A new approach to modelling schistosomiasis transmission based on stratified worm burden.

PubMed

Gurarie, D; King, C H; Wang, X

2010-11-01

Multiple factors affect schistosomiasis transmission in distributed meta-population systems including age, behaviour, and environment. The traditional approach to modelling macroparasite transmission often exploits the 'mean worm burden' (MWB) formulation for human hosts. However, typical worm distribution in humans is overdispersed, and classic models either ignore this characteristic or make ad hoc assumptions about its pattern (e.g., by assuming a negative binomial distribution). Such oversimplifications can give wrong predictions for the impact of control interventions. We propose a new modelling approach to macro-parasite transmission by stratifying human populations according to worm burden, and replacing MWB dynamics with that of 'population strata'. We developed proper calibration procedures for such multi-component systems, based on typical epidemiological and demographic field data, and implemented them using Wolfram Mathematica. Model programming and calibration proved to be straightforward. Our calibrated system provided good agreement with the individual level field data from the Msambweni region of eastern Kenya. The Stratified Worm Burden (SWB) approach offers many advantages, in that it accounts naturally for overdispersion and accommodates other important factors and measures of human infection and demographics. Future work will apply this model and methodology to evaluate innovative control intervention strategies, including expanded drug treatment programmes proposed by the World Health Organization and its partners.

Urban lymphatic filariasis in the metropolis of Dar es Salaam, Tanzania

PubMed Central

2013-01-01

Background The last decades have seen a considerable increase in urbanization in Sub-Saharan Africa, and it is estimated that over 50% of the population will live in urban areas by 2040. Rapid growth of cities combined with limited economic resources often result in informal settlements and slums with favorable conditions for proliferation of vectors of lymphatic filariasis (LF). In Dar es Salaam, which has grown more than 30 times in population during the past 55 years (4.4 million inhabitants in 2012), previous surveys have indicated high prevalences of LF. This study investigated epidemiological aspects of LF in Dar es Salaam, as a background for planning and implementation of control. Methods Six sites with varying distance from the city center (3–30 km) and covering different population densities, socioeconomic characteristics, and water, sewerage and sanitary facilities were selected for the study. Pupils from one public primary school at each site were screened for circulating filarial antigen (CFA; marker of adult worm infection) and antibodies to Bm14 (marker of exposure to transmission). Community members were examined for CFA, microfilariae and chronic manifestations. Structured questionnaires were administered to pupils and heads of community households, and vector surveys were carried out in selected households. Results The study indicated that a tremendous decrease in the burden of LF infection had occurred, despite haphazard urbanisation. Contributing factors may be urban malaria control targeting Anopheles vectors, short survival time of the numerous Culex quinquefasciatus vectors in the urban environment, widespread use of bed nets and other mosquito proofing measures, and mass drug administration (MDA) in 2006 and 2007. Although the level of ongoing transmission was low, the burden of chronic LF disease was still high. Conclusions The development has so far been promising, but continued efforts are necessary to ensure elimination of LF as a public health problem. These will include improving the awareness of people about the role of mosquitoes in transmission of LF, more thorough implementation of environmental sanitation to reduce Cx. quinquefasciatus breeding, continued MDA to high-risk areas, and set-up of programmes for management of chronic LF disease. PMID:24289718

The mathematical and computer modeling of the worm tool shaping

NASA Astrophysics Data System (ADS)

Panchuk, K. L.; Lyashkov, A. A.; Ayusheev, T. V.

2017-06-01

Traditionally mathematical profiling of the worm tool is carried out on the first T. Olivier method, known in the theory of gear gearings, with receiving an intermediate surface of the making lath. It complicates process of profiling and its realization by means of computer 3D-modeling. The purpose of the work is the improvement of mathematical model of profiling and its realization based on the methods of 3D-modeling. Research problems are: receiving of the mathematical model of profiling which excludes the presence of the making lath in it; realization of the received model by means of frame and superficial modeling; development and approbation of technology of solid-state modeling for the solution of the problem of profiling. As the basic, the kinematic method of research of the mutually envelope surfaces is accepted. Computer research is executed by means of CAD based on the methods of 3D-modeling. We have developed mathematical model of profiling of the worm tool; frame, superficial and solid-state models of shaping of the mutually enveloping surfaces of the detail and the tool are received. The offered mathematical models and the technologies of 3D-modeling of shaping represent tools for theoretical and experimental profiling of the worm tool. The results of researches can be used at design of metal-cutting tools.

Heterologous expression of the filarial nematode alt gene products reveals their potential to inhibit immune function

PubMed Central

Gomez-Escobar, Natalia; Bennett, Clare; Prieto-Lafuente, Lidia; Aebischer, Toni; Blackburn, Clare C; Maizels, Rick M

2005-01-01

Background Parasites exploit sophisticated strategies to evade host immunity that require both adaptation of existing genes and evolution of new gene families. We have addressed this question by testing the immunological function of novel genes from helminth parasites, in which conventional transgenesis is not yet possible. We investigated two such novel genes from Brugia malayi termed abundant larval transcript (alt), expression of which reaches ~5% of total transcript at the time parasites enter the human host. Results To test the hypothesis that ALT proteins modulate host immunity, we adopted an alternative transfection strategy to express these products in the protozoan parasite Leishmania mexicana. We then followed the course of infection in vitro in macrophages and in vivo in mice. Expression of ALT proteins, but not a truncated mutant, conferred greater infectivity of macrophages in vitro, reaching 3-fold higher parasite densities. alt-transfected parasites also caused accelerated disease in vivo, and fewer mice were able to clear infection of organisms expressing ALT. alt-transfected parasites were more resistant to IFN-γ-induced killing by macrophages. Expression profiling of macrophages infected with transgenic L. mexicana revealed consistently higher levels of GATA-3 and SOCS-1 transcripts, both associated with the Th2-type response observed in in vivo filarial infection. Conclusion Leishmania transfection is a tractable and informative approach to determining immunological functions of single genes from heterologous organisms. In the case of the filarial ALT proteins, our data suggest that they may participate in the Th2 bias observed in the response to parasite infection by modulating cytokine-induced signalling within immune system cells. PMID:15788098

Loss of sensitivity of immunochromatographic test (ICT) for lymphatic filariasis diagnosis in low prevalence settings: consequence in the monitoring and evaluation procedures.

PubMed

Gounoue-Kamkumo, Raceline; Nana-Djeunga, Hugues C; Bopda, Jean; Akame, Julie; Tarini, Ann; Kamgno, Joseph

2015-12-23

Diagnostic tools for lymphatic filariasis (LF) elimination programs are useful in mapping the distribution of the disease, delineating areas where mass drug administrations (MDA) are required, and determining when to stop MDA. The prevalence and burden of LF have been drastically reduced following mass treatments, and the evaluation of the performance of circulating filarial antigen (CFA)-based assays was acknowledged to be of high interest in areas with low residual LF endemicity rates after multiple rounds of MDA. The objective of this study was therefore to evaluate the immunochromatographic test (ICT) sensitivity in low endemicity settings and, specifically, in individuals with low intensity of lymphatic filariasis infection. To perform this study, calibrated thick blood smears, ICT and Og4C3 enzyme-linked immunosorbent assay (ELISA) were carried out by night to identify Wuchereria bancrofti microfilarial and circulating filarial antigen carriers. A threshold determination assay regarding ICT and ELISA was performed using serial plasma dilutions from individuals with positive microfilarial counts. All individuals harbouring microfilariae (positive blood films) were detected by ICT and ELISA, but among individuals positive for ELISA, only 35.7 % of them were detected using ICT (Chi square: 4.57; p-value = 0.03), indicating a moderate agreement between both tests (kappa statistics = 0.49). Threshold determination analyses showed that ELISA was still positive at the last plasma dilution with negative ICT result. These findings suggest a loss of sensitivity for ICT in low endemicity settings, especially in people exhibiting low levels of circulating filarial antigen, raising serious concern regarding the monitoring and evaluation procedures in the framework of LF elimination program.

CD4+CD25hiFOXP3+ Cells in Cord Blood of Neonates Born from Filaria Infected Mother Are Negatively Associated with CD4+Tbet+ and CD4+RORγt+ T Cells

PubMed Central

Zettlmeissl, Eva; van der Vlugt, Luciën E. P. M.; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G.; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

2014-01-01

Background Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. Methodology Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC) were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. Results No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = −0.242, P = 0.002; B = −0.178, P = 0.013 respectively). Conclusion Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check. PMID:25531674

Routes of uptake of diclofenac, fluoxetine, and triclosan into sediment-dwelling worms.

PubMed

Karlsson, Maja V; Marshall, Stuart; Gouin, Todd; Boxall, Alistair B A

2016-04-01

The present study investigated the route and degree of uptake of 2 ionizable pharmaceuticals (diclofenac and fluoxetine) and 1 ionizable compound used in personal care products (triclosan) into the sediment-dwelling worm Lumbriculus variegatus. Studies were done on complete worms ("feeding") and worms where the head was absent ("nonfeeding") using (14) C-labeled ingredients. Biota sediment accumulation factors (BSAF), based on uptake of (14) C, for feeding worms increased in the order fluoxetine (0.3) < diclofenac (0.5) < triclosan (9), which is correlated with a corresponding increase in log octanol-water partition coefficient. Biota sediment accumulation factor estimates are representative of maximum values because the degree of biotransformation in the worms was not quantified. Although no significant differences were seen between the uptake of diclofenac and that of fluoxetine in feeding and nonfeeding worms, uptake of the more hydrophobic antimicrobial, triclosan, into the feeding worms was significantly greater than that in the nonfeeding worms, with the 48-h BSAF for feeding worms being 36% higher than that for the nonfeeding worms. The results imply that dietary uptake contributes to the uptake of triclosan, which may be a result of the high hydrophobicity of the compound. Models that estimate exposure of ionizable substances may need to consider uptake from both the water column and food, particularly when assessing risks from dynamic exposures to organic contaminants. © 2015 SETAC.

The WORM site: worm.csirc.net

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, T.

2000-07-01

The Write One, Run Many (WORM) site (worm.csirc.net) is the on-line home of the WORM language and is hosted by the Criticality Safety Information Resource Center (CSIRC) (www.csirc.net). The purpose of this web site is to create an on-line community for WORM users to gather, share, and archive WORM-related information. WORM is an embedded, functional, programming language designed to facilitate the creation of input decks for computer codes that take standard ASCII text files as input. A functional programming language is one that emphasizes the evaluation of expressions, rather than execution of commands. The simplest and perhaps most common examplemore » of a functional language is a spreadsheet such as Microsoft Excel. The spreadsheet user specifies expressions to be evaluated, while the spreadsheet itself determines the commands to execute, as well as the order of execution/evaluation. WORM functions in a similar fashion and, as a result, is very simple to use and easy to learn. WORM improves the efficiency of today's criticality safety analyst by allowing: (1) input decks for parameter studies to be created quickly and easily; (2) calculations and variables to be embedded into any input deck, thus allowing for meaningful parameter specifications; (3) problems to be specified using any combination of units; and (4) complex mathematically defined models to be created. WORM is completely written in Perl. Running on all variants of UNIX, Windows, MS-DOS, MacOS, and many other operating systems, Perl is one of the most portable programming languages available. As such, WORM works on practically any computer platform.« less

Economic costs of endemic non-filarial elephantiasis in Wolaita Zone, Ethiopia.

PubMed

Tekola, Fasil; Mariam, Damen H; Davey, Gail

2006-07-01

Endemic non-filarial elephantiasis or podoconiosis is a chronic and debilitating geochemical disease occurring in individuals exposed to red clay soil derived from alkalic volcanic rock. It is a major public health problem in countries in tropical Africa, Central America and North India. To estimate the direct and the average productivity cost attributable to podoconiosis, and to compare the average productivity time of podoconiosis patients with non-patients. Matched comparative cross sectional survey involving 702 study subjects (patients and non-patients) supplemented by interviews with key informants in Wolaita Zone, southern Ethiopia. Total direct costs of podoconiosis amounted to the equivalent of US$ 143 per patient per year. The total productivity loss for a patient amounted to 45% of the total working days per year, causing a monetary loss equivalent to US$ 63. In Wolaita zone, the overall cost of podoconiosis exceeds US$ 16 million per year. Podoconiosis has enormous economic impact in affected areas. Simple preventive measures (such as use of robust footwear) must be promoted by health policy makers.

Vulval Elephantiasis: A Case Report

PubMed Central

Mohan, Harsh; Bisht, Bhumika; Goel, Poonam; Garg, Geeta

2012-01-01

Introduction. Elephantiasis is a chronic manifestation of filariasis; it commonly affects limbs, scrotum, and trunk. Females have lower incidence of filarial infection. Vulval elephantiasis due to filariasis is still rarer. It is difficult to make the diagnosis on histopathology alone, more so in view of the fact that the parasite is usually not identified in tissue sections. Identification of microfilariae in night samples of peripheral blood or seropositivity for filarial antigen is requisite for the correct diagnosis. Case Presentation. A young female presented with progressively increasing vulval swelling over a period of two years. The swelling was soft and measured 5 × 6 cm. Other possible differential diagnoses were excluded, and ancillary tests were performed to reach a conclusive diagnosis of vulval elephantiasis on histopathology. Conclusion. Vulval elephantiasis due to filariasis is rare. Its diagnosis on histopathology is more often by exclusion. High index of suspicion on microscopic findings and corelation with relevant diagnostic tests are required to reach the correct diagnosis. PMID:23198192

Sulfonamide chalcones: Synthesis and in vitro exploration for therapeutic potential against Brugia malayi.

PubMed

Bahekar, Sandeep P; Hande, Sneha V; Agrawal, Nikita R; Chandak, Hemant S; Bhoj, Priyanka S; Goswami, Kalyan; Reddy, M V R

2016-11-29

Keeping in mind the immense biological potential of chalcones and sulfonamide scaffolds, a library of sulfonamide chalcones has been synthesized and evaluated for in vitro antifilarial assay against human lymphatic filarial parasite Brugia malayi. Experimental evidence showcased for the first time the potential of some sulfonamide chalcones as effective and safe antifilarial lead molecules against human lymphatic filarial parasite B. malayi. Sulfonamide chalcones 4d, 4p, 4q, 4t and 4aa displayed the significantly wide therapeutic window. Particularly chalcones with halogen substitution in aromatic ring proved to be potent antifilarial agents against Brugia malayi. Sulphonamide chalcones with lipophilic methyl moiety (4q and 4aa) at para position of terminal phenyl rings of compounds were found to have remarkable antifilarial activities with therapeutic efficacy. Observed preliminary evidence of apoptosis by effective chalcone derivatives envisaged its fair possibility to inhibit folate pathway with consequent defect in DNA synthesis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A Cell-Based Screen Reveals that the Albendazole Metabolite, Albendazole Sulfone, Targets Wolbachia

PubMed Central

Bray, Walter M.; White, Pamela M.; Ruybal, Jordan; Lokey, R. Scott; Debec, Alain; Sullivan, William

2012-01-01

Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts. PMID:23028321

Selenium Status Alters the Immune Response and Expulsion of Adult Heligmosomoides bakeri Worms in Mice

PubMed Central

Cheung, Lumei; Beshah, Ethiopia; Shea-Donohue, Terez; Urban, Joseph F.

2013-01-01

Heligmosomoides bakeri is a nematode with parasitic development exclusively in the small intestine of infected mice that induces a potent STAT6-dependent Th2 immune response. We previously demonstrated that host protective expulsion of adult H. bakeri worms from a challenge infection was delayed in selenium (Se)-deficient mice. In order to explore mechanisms associated with the delayed expulsion, 3-week-old female BALB/c mice were placed on a torula yeast-based diet with or without 0.2 ppm Se, and after 5 weeks, they were inoculated with H. bakeri infective third-stage larvae (L3s). Two weeks after inoculation, the mice were treated with an anthelmintic and then rested, reinoculated with L3s, and evaluated at various times after reinoculation. Analysis of gene expression in parasite-induced cysts and surrounding tissue isolated from the intestine of infected mice showed that the local-tissue Th2 response was decreased in Se-deficient mice compared to that in Se-adequate mice. In addition, adult worms recovered from Se-deficient mice had higher ATP levels than worms from Se-adequate mice, indicating greater metabolic activity in the face of a suboptimal Se-dependent local immune response. Notably, the process of worm expulsion was restored within 2 to 4 days after feeding a Se-adequate diet to Se-deficient mice. Expulsion was associated with an increased local expression of Th2-associated genes in the small intestine, intestinal glutathione peroxidase activity, secreted Relm-β protein, anti-H. bakeri IgG1 production, and reduced worm fecundity and ATP-dependent metabolic activity. PMID:23649095

Worm-stars and half-worms: Novel dangers and novel defense.

PubMed

Hodgkin, Jonathan; Clark, Laura C; Gravato-Nobre, Maria J

2014-01-01

In a recent paper, we reported the isolation and surprising effects of two new bacterial pathogens for Caenorhabditis and related nematodes. These two pathogens belong to the genus Leucobacter and were discovered co-infecting a wild isolate of Caenorhabditis that had been collected in Cape Verde. The interactions of these bacteria with C. elegans revealed both unusual mechanisms of pathogenic attack, and an unexpected defense mechanism on the part of the worm. One pathogen, known as Verde1, is able to trap swimming nematodes by sticking their tails together, resulting in the formation of "worm-star" aggregates, within which worms are killed and degraded. Trapped larval worms, but not adults, can sometimes escape by undergoing whole-body autotomy into half-worms. The other pathogen, Verde2, kills worms by a different mechanism associated with rectal infection. Many C. elegans mutants with alterations in surface glycosylation are resistant to Verde2 infection, but hypersensitive to Verde1, being rapidly killed without worm-star formation. Conversely, surface infection of wild-type worms with Verde1 is mildly protective against Verde2. Thus, there are trade-offs in susceptibility to the two bacteria. The Leucobacter pathogens reveal novel nematode biology and provide powerful tools for exploring nematode surface properties and bacterial susceptibility.

Anthelmintic activity in vitro and in vivo of Baccharis trimera (Less) DC against immature and adult worms of Schistosoma mansoni.

PubMed

de Oliveira, Rosimeire Nunes; Rehder, Vera Lúcia Garcia; Oliveira, Adriana Silva Santos; Jeraldo, Veronica de Lourdes Sierpe; Linhares, Arício Xavier; Allegretti, Silmara Marques

2014-04-01

Although its efficiency against all Schistosoma species, praziquantel (PZQ) shows low efficacy against schistosomula and juvenile stages. The potential for development of resistance to PZQ has justified the search for new alternative chemotherapies. In this scenario, studies to new formulations, more comprehensive and without adverse effects, are being conducted. One viable and promising treatment is the study of medicinal plants as a new approach to the experimental treatment for Schistosomiasis. Amongst all the variety of the medicinal species studied, we can highlight Baccharis trimera (Less) DC, known as "Carqueja-amarga". This paper not only describes the effect of crude dichloromethane extract (DE) and aqueous fraction (AF) obtained from B. trimera, in vitro but also is the first one that investigates the in vivo efficacy of B. trimera against schistosomula, juvenile and adult worms of Schistosoma mansoni BH strain. In the experiment, mice were treated with DE, AF and PZQ (40 and 200mg/kg) over the period of larval development (3 and 30 post-infection; pi), and adult worms (60days post-infection; pi). The in vitro results show that the DE and AF effects are dose-dependents, being the 130μg/mL the most effective one in a shorter period of incubation. The exposure of the in vitro samples over adult parasites were able to inhibit 100% of the oviposition in females. Likewise caused the mortality of the parasites with morphological alterations on the tegument, on the suckers, oral and acetabulum, in both males and females after 6-72h of exposure. Additionally, the in vivo treatments against juvenile and adult infection were more effective compared to the control group untreated. Administrations of AF and DE in day 30pi (juvenile worms) show female worm total burden reductions of 75% and 68% respectively. At the same period of infection reductions of respectively 98% and 97% egg/g in the faeces were seen. In relation to the different egg developmental stages (oogram), the results showed significant reductions, due to the reduction in the number of worms, especially the females. In conclusion, B. trimera exhibits major schistosomicidal effects in vivo against immature and adult worms of S. mansoni, opening up perspectives for future researches on substance or compound isolation and the elucidation of its mechanisms of action. Copyright © 2014 Elsevier Inc. All rights reserved.

Do developmental temperatures affect redox level and lifespan in C. elegans through upregulation of peroxiredoxin?

PubMed

Henderson, Dylan; Huebner, Christian; Markowitz, Moses; Taube, Nicole; Harvanek, Zachary M; Jakob, Ursula; Knoefler, Daniela

2018-04-01

Lifespan in poikilothermic organisms, such as Caenorhabditis elegans, can be substantially increased simply by decreasing growth temperature. To gain insights into the mechanistic underpinnings of this effect, we investigated the effects of temperature in development and adulthood on C. elegans lifespan. We found that worms exposed to 25°C during development and shifted to 15°C in adulthood exhibited an even longer lifespan than animals constantly kept at 15°C. Analysis of the in vivo redox status demonstrated that at 25°C, C. elegans larvae have a more reduced redox state and higher Prdx-2 expression levels than animals raised at 15°C. Worms lacking prdx-2 fail to show the additional lifespan extension upon shift from 25°C to 15°C and reveal a lifespan similar to prdx-2 worms always kept at 15°C. These results suggest that transiently altering the in vivo redox state during development can have highly beneficial long-term consequences for organisms. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Chitin synthase in the filarial parasite, Brugia malayi.

PubMed

Harris, M T; Lai, K; Arnold, K; Martinez, H F; Specht, C A; Fuhrman, J A

2000-12-01

Fragments of putative chitin synthase (chs) genes from two filarial species (Brugia malayi and Dirofilaria immitis) were amplified by PCR using degenerate primers. The full genomic and cDNA sequences were obtained for the B. malayi chs gene (Bm-chs-1); the predicted amino acid sequence is highly similar, over a large region, to two CHS sequences of the nematode Caenorhabditis elegans and also to two insect CHS sequences. Bm-chs-1 is abundantly transcribed in B. malayi adult females, independent of their fertilization status, but is also expressed in males and microfilariae. Oocytes and early embryos contain large amounts of Bm-chs-1 transcript by in situ hybridization, but later stage embryos within the maternal uterus show little or no Bm-chs-1 transcript. No specific hybridization could be demonstrated in maternal somatic tissues. Polyclonal antibodies were raised against a peptide expressed from a recombinant cDNA fragment of Bm-chs-1; immunostaining detected CHS protein in oocytes and early to midstage embryos. These studies characterize a gene that is likely to be essential to oogenesis and embryonic development in a parasitic nematode. Because chitin synthesis and eggshell formation begin after fertilization, the presence of CHS protein in early oocytes suggests that the enzyme must be activated as a result of fertilization. These studies also demonstrate that chitin synthesis may not be restricted to eggshell formation in nematodes, as the Bm-chs-1 gene is transcribed in life cycle stages other than adult females.

21 CFR 520.45b - Albendazole paste.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (Fasciola hepatica); heads and segments of tapeworms (Moniezia benedeni, M. expansa); adult and 4th stage larvae of stomach worms (brown stomach worms including 4th stage inhibited larvae (Ostertagia ostertagi); barberpole worm (Haemonchus contortus, H. placei); small stomach worm (Trichostrongylus axei)); adult and 4th...

Effects of alcoholic extract of Curcuma longa on Ascaridia infestation affecting chicken.

PubMed

Alrubaie, Abdulrazak Labi

2015-07-01

Ascaridia galli, the common intestinal nematode, remains a major cause of economic loss in the poultry industry in developing countries. Treatments using chemicals are not only expensive but also affect host health. Plant extracts as better alternative is gaining significance. Here, we have studied the effects of alcoholic extract of turmeric, Curcuma longa L. (Zingiberaceae) roots, against A. galli infection in chicken. Different concentrations of C. longa root extract were tested in vitro on 5 groups of adults A. galli worms and in vivo on 6 groups of chicks. The results showed that the turmeric root extract @ 60 mg mL(-1) in vitro significantly (P < 0.001) proved paralytic and fatal against worms (16.80 ± 1.28 h). In vivo, chicken groups (G2-G6) were infected with an average of 300 ± 12 embryonated eggs of A. galli. The G2 was not given any treatment while G3 was treated with piperazine (@ 200 mg kg(-1) body wt.); and Groups 4, 5 and 6 were given turmeric @ 200, 400 and 600 mg kg(-1) body wt., respectively. The mean number of worms extracted at the end of the trial in G2 (untreated) was 18.10 ± 2.42, while the G3 treated with piperazine had no worms. Groups 4 and 5 did not show any significant difference compared to G2. However, G6 that had 3.20 ± 1.33 worms was statistically significant. Higher concentrations of turmeric given to infected chickens significantly reduced the length and weight of worms. The study showed that the worm infestation damaged the intestinal villi, and.treatment with high concentration of C. longa had healing effects and restored the integrity of intestinal mucosa. The results have demonstrated the ameliorating effect of C. longa turmeric on A. galli infested chickens.

The hatching larva of the priapulid worm Halicryptus spinulosus

PubMed Central

Janssen, Ralf; Wennberg, Sofia A; Budd, Graham E

2009-01-01

Despite their increasing evolutionary importance, basic knowledge about the priapulid worms remains limited. In particular, priapulid development has only been partially documented. Following previous description of hatching and the earliest larval stages of Priapulus caudatus, we here describe the hatching larva of Halicryptus spinulosus. Comparison of the P. caudatus and the H. spinulosus hatching larvae allows us to attempt to reconstruct the ground pattern of priapulid development. These findings may further help unravelling the phylogenetic position of the Priapulida within the Scalidophora and hence contribute to the elucidation of the nature of the ecdysozoan ancestor. PMID:19470151

The hatching larva of the priapulid worm Halicryptus spinulosus.

PubMed

Janssen, Ralf; Wennberg, Sofia A; Budd, Graham E

2009-05-26

Despite their increasing evolutionary importance, basic knowledge about the priapulid worms remains limited. In particular, priapulid development has only been partially documented. Following previous description of hatching and the earliest larval stages of Priapulus caudatus, we here describe the hatching larva of Halicryptus spinulosus. Comparison of the P. caudatus and the H. spinulosus hatching larvae allows us to attempt to reconstruct the ground pattern of priapulid development. These findings may further help unravelling the phylogenetic position of the Priapulida within the Scalidophora and hence contribute to the elucidation of the nature of the ecdysozoan ancestor.

The Worm Propagation Model with Dual Dynamic Quarantine Strategy

NASA Astrophysics Data System (ADS)

Yao, Yu; Xie, Xiao-Wu; Guo, Hao; Gao, Fu-Xiang; Yu, Ge

Internet worms are becoming more and more harmful with the rapid development of the Internet. Due to the extremely fast spread and great destructive power of network worms, strong dynamic quarantine strategies are necessary. Inspired by the real-world approach to the prevention and treatment of infectious diseases, this paper proposes a quarantine strategy based on dynamic worm propagation model: the SIQRV dual quarantine model. This strategy uses dynamic quarantine method to make the vulnerable host and infected host quarantined, and then release them after a certain period of time, regardless of whether quarantined host security is checked. Through mathematic modeling, it has been found that when the basic reproduction number R0 is less than a critical value, the system will stabilize in the disease-free equilibrium, that is, in theory, the infected hosts will be completely immune. Finally, by comparing the simulation results and numerical analysis, the basic agreement between the two curves supports the validity of the mathematical model. Our future work will be focusing on taking both the delay and double-quarantine strategy into account and further expanding the scale of our simulation work.

WormBase 2016: expanding to enable helminth genomic research.

PubMed

Howe, Kevin L; Bolt, Bruce J; Cain, Scott; Chan, Juancarlos; Chen, Wen J; Davis, Paul; Done, James; Down, Thomas; Gao, Sibyl; Grove, Christian; Harris, Todd W; Kishore, Ranjana; Lee, Raymond; Lomax, Jane; Li, Yuling; Muller, Hans-Michael; Nakamura, Cecilia; Nuin, Paulo; Paulini, Michael; Raciti, Daniela; Schindelman, Gary; Stanley, Eleanor; Tuli, Mary Ann; Van Auken, Kimberly; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Wright, Adam; Yook, Karen; Berriman, Matthew; Kersey, Paul; Schedl, Tim; Stein, Lincoln; Sternberg, Paul W

2016-01-04

WormBase (www.wormbase.org) is a central repository for research data on the biology, genetics and genomics of Caenorhabditis elegans and other nematodes. The project has evolved from its original remit to collect and integrate all data for a single species, and now extends to numerous nematodes, ranging from evolutionary comparators of C. elegans to parasitic species that threaten plant, animal and human health. Research activity using C. elegans as a model system is as vibrant as ever, and we have created new tools for community curation in response to the ever-increasing volume and complexity of data. To better allow users to navigate their way through these data, we have made a number of improvements to our main website, including new tools for browsing genomic features and ontology annotations. Finally, we have developed a new portal for parasitic worm genomes. WormBase ParaSite (parasite.wormbase.org) contains all publicly available nematode and platyhelminth annotated genome sequences, and is designed specifically to support helminth genomic research. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Fatal case of ectopic enterobiasis: Enterobius vermicularis in the kidneys.

PubMed

Serpytis, Mindaugas; Seinin, Dmitrij

2012-02-01

Enterobius vermicularis is one of the most common intestinal parasites found in humans. They commonly infest the terminal ileum and large intestine, and are usually considered an innocuous parasite that can be easily eradicated with proper treatment. However, extraintestinal migration of worms, although very rare, may lead to severe health disorders or even death. This article, reports the first fatal case of ectopic enterobiasis known to the authors, which developed in an adult patient with E. vermicularis infection, causing perforation of the large intestine and generalized bacterial peritonitis. Despite emergency laparotomy, the patient died from septic shock on the day after surgery. During pathological examination, worms were found not only in the large intestine, but also in the renal parenchyma; worm eggs were found deposited in the lungs as well.

Diurnal migration of Echinostoma caproni (Digenea: Echinostomatidae) in ICR mice.

PubMed

Platt, Thomas R; Graf, Emily; Kammrath, Anna; Zelmer, Derek A

2010-12-01

Twenty-four female ICR mice, 12 acclimated to a 12 ∶ 12 light-dark cycle and 12 to a 12 ∶ 12 dark-light cycle for 7 days, were each infected with 10 metacercariae of Echinostoma caproni. Infected mice were maintained on their respective lighting regimes for 28 days. Six mice (3 from each group) were necropsied at 4-hr intervals beginning at 0700 hr. The small intestine was removed, opened, and the position of individual worms and worm clusters was measured to the nearest 0.1 cm. Each intestine was subsequently divided into 20 equal segments and individual worms and worm clusters were assigned to the appropriate segment based on the original measurements. All worms were found in the posterior 55% of the intestine (ileum). All posterior segments (10-20), with the exception of segment 18, harbored at least 1 worm at some time. A Monte Carlo simulation of worm abundance in segments 10-17 over all time periods indicated a random distribution, while the same analysis of segments 10-20 indicated a non-random distribution due to large numbers of worms in segment 20 and to the absence of worms in segment 18. To analyze temporal changes in worm distribution, mice were grouped by time of necropsy as follows: night (1900 and 2300 hr), morning (0300 and 0700 hr), and day (1100 and 1500 hr). During the night and morning, E. caproni was heavily concentrated in segments 10-17 and, during the day, worms were located more posteriorly, with a heavy concentration in the last segment (20).

Dot-Blot Immunoassay of Fasciola gigantica Infection using 27 kDa and Adult Worm Regurge Antigens in Egyptian Patients

PubMed Central

Kamel, Hanan H.; Saad, Ghada A.

2013-01-01

The purpose of the present study was to evaluate the potential role of the 27-Kilodalton (KDa) antigen versus Fasciola gigantica adult worm regurge antigens in a DOT-Blot assay and to assess this assay as a practical tool for diagnosis fascioliasis in Egyptian patients. Fasciola gigantica antigen of an approximate molecular mass 27-(KDa) was obtained from adult worms by a simple elution SDS-PAGE. A Dot-Blot was developed comparatively to adult worm regurge antigens for the detection of specific antibodies from patients infected with F. gigantica in Egypt. Control sera were obtained from patients with other parasitic infections and healthy volunteers to assess the test and compare between the antigens. The sensitivity, specificity, positive and negative predictive values of Dot-Blot using the adult worm regurge were 80%, 90%, 94.1%, and 69.2% respectively, while those using 27-KDa were 100% which confirms the diagnostic potential of this antigen. All patients infected with Fasciola were positive, with cross reactivity reported with Schistosoma mansoni serum samples. This 27-KDa Dot-Blot assay showed to be a promising test which can be used for serodiagnosis of fascioliasis in Egyptian patients especially, those presenting with hepatic disease. It is specific, sensitive and easy to perform method for the rapid diagnosis particularly when more complex laboratory tests are unavailable. PMID:23710084

Dot-blot immunoassay of Fasciola gigantica infection using 27 kDa and adult worm regurge antigens in Egyptian patients.

PubMed

Kamel, Hanan H; Saad, Ghada A; Sarhan, Rania M

2013-04-01

The purpose of the present study was to evaluate the potential role of the 27-Kilodalton (KDa) antigen versus Fasciola gigantica adult worm regurge antigens in a DOT-Blot assay and to assess this assay as a practical tool for diagnosis fascioliasis in Egyptian patients. Fasciola gigantica antigen of an approximate molecular mass 27-(KDa) was obtained from adult worms by a simple elution SDS-PAGE. A Dot-Blot was developed comparatively to adult worm regurge antigens for the detection of specific antibodies from patients infected with F. gigantica in Egypt. Control sera were obtained from patients with other parasitic infections and healthy volunteers to assess the test and compare between the antigens. The sensitivity, specificity, positive and negative predictive values of Dot-Blot using the adult worm regurge were 80%, 90%, 94.1%, and 69.2% respectively, while those using 27-KDa were 100% which confirms the diagnostic potential of this antigen. All patients infected with Fasciola were positive, with cross reactivity reported with Schistosoma mansoni serum samples. This 27-KDa Dot-Blot assay showed to be a promising test which can be used for serodiagnosis of fascioliasis in Egyptian patients especially, those presenting with hepatic disease. It is specific, sensitive and easy to perform method for the rapid diagnosis particularly when more complex laboratory tests are unavailable.

RESISTANCE PRODUCED IN MICE BY EXPOSURE TO IRRADIATED SCHISTOSOMA MANSONI CERCARIAE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radke, M.G.; Sadun, E.H.

1963-04-01

Studies were undertaken to determine whether gamma irradiation of cercariae might provide a means of investigating some of the mechanisms involved in the acquired resistance to schistosomiasis. Control mice received 200 nonirradiated cercariae, and other groups received the same number of cercariae that had been exposed to 6 different doses of Co/sup 60/ gamma irradiation varying from 1000--20000 rep. Eight weeks later the worms recovered were counted. Doses of 4000 rep or higher completely inhibited the development of schistosomes. A few stunted and underdeveloped worms were found in some of the mice receiving cercariae irradiated at 2500 and 3000 rep.more » Some adult schistosomes were observed in the groups receiving 1500 and 2000 rep and eggs were found in the liver but not in the stools of some mice. However, all of the mice exposed to cercariae irradiated with 1000 rep had eggs in liver and stools. The worm burden decreased regularly with increasing dosages up to 3000 rep, beyond which no worms were found at necropsy. The decrease in the number of worms mice acquired was linear only when cercariae were exposed from 1000to 2000 rep, however, even beyond such dosages, it followed a straight line when the logarithm of irradiation dose was plotied. Acquired resistance to S. mansoni was observed in mice following a previous exposure to irradiated cercariae. (TCO)« less

Screening for potential anti-infective agents towards Burkholderia pseudomallei infection

NASA Astrophysics Data System (ADS)

Eng, Su Anne; Nathan, Sheila

2014-09-01

The established treatment for melioidosis is antibiotic therapy. However, a constant threat to this form of treatment is resistance development of the causative agent, Burkholderia pseudomallei, towards antibiotics. One option to circumvent this threat of antibiotic resistance is to search for new alternative anti-infectives which target the host innate immune system and/or bacterial virulence. In this study, 29 synthetic compounds were evaluated for their potential to increase the lifespan of an infected host. The nematode Caenorhabditis elegans was adopted as the infection model as its innate immune pathways are homologous to humans. Screens were performed in a liquid-based survival assay containing infected worms exposed to individual compounds and survival of untreated and compound-treated worms were compared. A primary screen identified nine synthetic compounds that extended the lifespan of B. pseudomallei-infected worms. Subsequently, a disc diffusion test was performed on these selected compounds to delineate compounds into those that enhanced the survival of worms via antimicrobial activity i.e. reducing the number of infecting bacteria, or into those that did not target pathogen viability. Out of the nine hits selected, two demonstrated antimicrobial effects on B. pseudomallei. Therefore, the findings from this study suggest that the other seven identified compounds are potential anti-infectives which could protect a host against B. pseudomallei infection without developing the risk of drug resistance.

High-Fidelity Modeling of Computer Network Worms

DTIC Science & Technology

2004-06-22

plots the propagation of the TCP-based worm. This execution is among the largest TCP worm models simulated to date at packet-level. TCP vs . UDP Worm...the mapping of the virtual IP addresses to honeyd’s MAC address in the proxy’s ARP table. The proxy server listens for packets from both sides of...experimental setup, we used two ntium-4 ThinkPad , and an IBM Pentium-III ThinkPad ), running the proxy server and honeyd respectively. The Code Red II worm

Laboratory and field evaluation of medicinal plant extracts against filarial vector, Culex quinquefasciatus Say (Diptera: Culicidae)

USDA-ARS?s Scientific Manuscript database

In this study, chemical extracts of Jatropha curcas, Hyptis suaveolens, Abutilon indicum, and Leucas aspera were tested for toxicity to larvae of the filariasis vector Culex quinquefasciatus. Respective median lethal concentrations (LC50) for hexane, chloroform, ethyl acetate, and methanol extracts...

Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts

USDA-ARS?s Scientific Manuscript database

Wolbachia, the most widely studied endosymbiont in arthropods, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new strain (wPpe) in the plant-parasitic nem...

Lifespan-on-a-chip: microfluidic chambers for performing lifelong observation of C. elegans†

PubMed Central

Hulme, S. Elizabeth; Shevkoplyas, Sergey S.; McGuigan, Alison P.; Apfeld, Javier; Fontana, Walter

2011-01-01

This article describes the fabrication of a microfluidic device for the liquid culture of many individual nematode worms (Caenorhabditis elegans) in separate chambers. Each chamber houses a single worm from the fourth larval stage until death, and enables examination of a population of individual worms for their entire adult lifespans. Adjacent to the chambers, the device includes microfluidic worm clamps, which enable periodic, temporary immobilization of each worm. The device made it possible to track changes in body size and locomotion in individual worms throughout their lifespans. This ability to perform longitudinal measurements within the device enabled the identification of age-related phenotypic changes that correlate with lifespan in C. elegans. PMID:20162234

Development and chromosome mechanics in nematodes: Results from IML-1

NASA Astrophysics Data System (ADS)

Nelson, G. A.; Schubert, W. W.; Kazarians, G. A.; Richards, G. F.

1994-08-01

A subset of the Caenorhabditis elegans nematodes flown aboard Biorack on IML-1 was analyzed for the fidelity of development and the mechanics of chromosomes at meiosis. To assess meiosis, mutant worms marked at two linked or unlinked loci were inoculated as heterozygous hermaphrodites and allowed to self fertilize. Mendelian segregation ratios and recombination frequency were measured for offspring produced at 1XG or in microgravity. To assess development, worms and embryos were fixed and stained with the DNA dye, DAPI, or antibodies specific for antigens expressed in germ cells, pharyngeal and body wall muscles, and gut cells. The distribution of cytoplasmic determinants, cell nuclei counts and positions were scored to assess symmetry relations and anatomical features.

Chemistry and the worm: Caenorhabditis elegans as a platform for integrating chemical and biological research.

PubMed

Hulme, S Elizabeth; Whitesides, George M

2011-05-16

This Review discusses the potential usefulness of the worm Caenorhabditis elegans as a model organism for chemists interested in studying living systems. C. elegans, a 1 mm long roundworm, is a popular model organism in almost all areas of modern biology. The worm has several features that make it attractive for biology: it is small (<1000 cells), transparent, and genetically tractable. Despite its simplicity, the worm exhibits complex phenotypes associated with multicellularity: the worm has differentiated cells and organs, it ages and has a well-defined lifespan, and it is capable of learning and remembering. This Review argues that the balance between simplicity and complexity in the worm will make it a useful tool in determining the relationship between molecular-scale phenomena and organism-level phenomena, such as aging, behavior, cognition, and disease. Following an introduction to worm biology, the Review provides examples of current research with C. elegans that is chemically relevant. It also describes tools-biological, chemical, and physical-that are available to researchers studying the worm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cuticular surface damage of Ascaridia galli adult worms treated with Veitchia merrillii betel nuts extract in vitro.

PubMed

Balqis, Ummu; Hambal, Muhammad; Rinidar; Athaillah, Farida; Ismail; Azhar; Vanda, Henni; Darmawi

2017-07-01

The objective of this research was to in vitro evaluate the cuticular surface damage of Ascaridia galli adult worms treated with ethanolic extract of betel nuts Veitchia merrillii . Phytochemical screening was done using FeCl 3 , Wagner and Dragendorff reagents, NaOH, MgHCl, and Liebermann-Burchard reaction test. Amount of 16 worms were segregated into four groups with three replicates. Four worms of each group submerged into phosphate buffered saline, 25 mg/ml, and 75 mg/ml crude ethanolic extract of V. merrillii , and 15 mg/ml albendazole. The effect of these extract was observed 40 h after incubation as soon as worms death. The worms were sectioned transversally and were explored for any cuticular histopathological changes in their body surface under microscope. We found that the ethanolic extract of V. merrillii betel nuts contains tannins, alkaloids, flavonoids, triterpenoids, and saponins. The ethanolic extract of betel nuts V. merrillii induces surface alterations caused cuticular damage of A. galli adult worms. We concluded that ethanolic extract of betel nuts V. merrillii possess anthelmintic activity caused cuticular damage of A. galli adult worms.

A calibration mechanism based on worm drive for space telescope

NASA Astrophysics Data System (ADS)

Chong, Yaqin; Li, Chuang; Xia, Siyu; Zhong, Peifeng; Lei, Wang

2017-08-01

In this paper, a new type of calibration mechanism based on worm drive is presented for a space telescope. This calibration mechanism based on worm drive has the advantages of compact size and self-lock. The mechanism mainly consists of thirty-six LEDs as the light source for flat calibration, a diffuse plate, a step motor, a worm gear reducer and a potentiometer. As the main part of the diffuse plate, a PTFE tablet is mounted in an aluminum alloy frame. The frame is fixed on the shaft of the worm gear, which is driven by the step motor through the worm. The shaft of the potentiometer is connected to that of the worm gear to measure the rotation angle of the diffuse plate through a flexible coupler. Firstly, the calibration mechanism is designed, which includes the LEDs assembly design, the worm gear reducer design and the diffuse plate assembly design. The counterweight blocks and two end stops are also designed for the diffuse plate assembly. Then a modal analysis with finite element method for the diffuse plate assembly is completed.

Growth and ontogeny of the tapeworm Schistocephalus solidus in its copepod first host affects performance in its stickleback second intermediate host

PubMed Central

2012-01-01

Background For parasites with complex life cycles, size at transmission can impact performance in the next host, thereby coupling parasite phenotypes in the two consecutive hosts. However, a handful of studies with parasites, and numerous studies with free-living, complex-life-cycle animals, have found that larval size correlates poorly with fitness under particular conditions, implying that other traits, such as physiological or ontogenetic variation, may predict fitness more reliably. Using the tapeworm Schistocephalus solidus, we evaluated how parasite size, age, and ontogeny in the copepod first host interact to determine performance in the stickleback second host. Methods We raised infected copepods under two feeding treatments (to manipulate parasite growth), and then exposed fish to worms of two different ages (to manipulate parasite ontogeny). We assessed how growth and ontogeny in copepods affected three measures of fitness in fish: infection probability, growth rate, and energy storage. Results Our main, novel finding is that the increase in fitness (infection probability and growth in fish) with larval size and age observed in previous studies on S. solidus seems to be largely mediated by ontogenetic variation. Worms that developed rapidly (had a cercomer after 9 days in copepods) were able to infect fish at an earlier age, and they grew to larger sizes with larger energy reserves in fish. Infection probability in fish increased with larval size chiefly in young worms, when size and ontogeny are positively correlated, but not in older worms that had essentially completed their larval development in copepods. Conclusions Transmission to sticklebacks as a small, not-yet-fully developed larva has clear costs for S. solidus, but it remains unclear what prevents the evolution of faster growth and development in this species. PMID:22564512

Planarian D-amino acid oxidase is involved in ovarian development during sexual induction.

PubMed

Maezawa, Takanobu; Tanaka, Hiroyuki; Nakagawa, Haruka; Ono, Mizuki; Aoki, Manabu; Matsumoto, Midori; Ishida, Tetsuo; Horiike, Kihachiro; Kobayashi, Kazuya

2014-05-01

To elucidate the molecular mechanisms underlying switching from asexual to sexual reproduction, namely sexual induction, we developed an assay system for sexual induction in the hermaphroditic planarian species Dugesia ryukyuensis. Ovarian development is the initial and essential step in sexual induction, and it is followed by the formation of other reproductive organs, including the testes. Here, we report a function of a planarian D-amino acid oxidase, Dr-DAO, in the control of ovarian development in planarians. Asexual worms showed significantly more widespread expression of Dr-DAO in the parenchymal space than did sexual worms. Inhibition of Dr-DAO by RNAi caused the formation of immature ovaries. In addition, we found that feeding asexual worms 5 specific D-amino acids could induce the formation of immature ovaries that are similar to those observed in Dr-DAO knockdown worms, suggesting that Dr-DAO inhibits the formation of immature ovaries by degrading these D-amino acids. Following sexual induction, Dr-DAO expression was observed in the ovaries. The knockdown of Dr-DAO during sexual induction delayed the maturation of the other reproductive organs, as well as ovary. These findings suggest that Dr-DAO acts to promote ovarian maturation and that complete sexual induction depends on the production of mature ovaries. We propose that Dr-DAO produced in somatic cells prevents the onset of sexual induction in the asexual state, and then after sexual induction, the female germ cells specifically produce Dr-DAO to induce full maturation. Therefore, Dr-DAO produced in somatic and female germline cells may play different roles in sexual induction. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effects of water temperature and substrate type on spore production and release in eastern Tubifex tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Blazer, V.S.; Waldrop, T.B.; Schill, W.B.; Densmore, Christine L.; Smith, D.

2003-01-01

Eastern Tubifex tubifex worms were exposed to Myxobolus cerebralis spores at 9, 13, 17, and 20 C in 1-L jars that contained sand, mud, or leaf litter as substrata. Beginning 60 days after exposure, water from each jar was filtered daily and examined for the presence of waterborne triactinomyxon spores (TAMs). On discovering a single TAM from an experimental jar, 48 T. tubifex worms from that jar were placed individually into 24-well plates. Spores released from individual infected T. tubifex worms were quantified to determine the first day of TAM release from infected worms, the infection rate, the total number of TAMs released per worm, and the duration of release. No TAMs were found in any of the jars incubated at 20 C or in uninfected, control worms at any temperature. The total number of TAMs released by infected worms in mud and sand was highest at 13 C compared with other temperatures. Infection rates among individual worms increased with temperature between 9 and 17 C. Higher temperatures (up to 17 C) induced earlier TAM releases among infected worms, and substratum did not influence this production parameter. The average duration of TAM release decreased as the temperature increased from 9 to 17 C, and there was a significant effect of substratum in the groups maintained at 13 and 17 C. In all temperature treatments between 9 and 17 C, the duration of release was least in the worms maintained in leaf litter, as was the total number of TAMs released during the experimental period and the median number of TAMs per production day.

Two Leucobacter Strains Exert Complementary Virulence on Caenorhabditis Including Death by Worm-Star Formation

PubMed Central

Hodgkin, Jonathan; Félix, Marie-Anne; Clark, Laura C.; Stroud, Dave; Gravato-Nobre, Maria J.

2013-01-01

Summary The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine [1, 2], while others attack via its external surface [1, 3–6]. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses [7, 8]. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated “worm-stars.” Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection [6]. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi [4]. PMID:24206844

Two Leucobacter strains exert complementary virulence on Caenorhabditis including death by worm-star formation.

PubMed

Hodgkin, Jonathan; Félix, Marie-Anne; Clark, Laura C; Stroud, Dave; Gravato-Nobre, Maria J

2013-11-04

The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine, while others attack via its external surface. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated "worm-stars." Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

A full scale worm reactor for efficient sludge reduction by predation in a wastewater treatment plant.

PubMed

Tamis, J; van Schouwenburg, G; Kleerebezem, R; van Loosdrecht, M C M

2011-11-15

Sludge predation can be an effective solution to reduce sludge production at a wastewater treatment plant. Oligochaete worms are the natural consumers of biomass in benthic layers in ecosystems. In this study the results of secondary sludge degradation by the aquatic Oligochaete worm Aulophorus furcatus in a 125 m(3) reactor and further sludge conversion in an anaerobic tank are presented. The system was operated over a period of 4 years at WWTP Wolvega, the Netherlands and was fed with secondary sludge from a low loaded activated sludge process. It was possible to maintain a stable and active population of the aquatic worm species A. furcatus during the full period. Under optimal conditions a sludge conversion of 150-200 kg TSS/d or 1.2-1.6 kg TSS/m(3)/d was established in the worm reactor. The worms grew as a biofilm on carrier material in the reactor. The surface specific conversion rate reached 140-180 g TSS/m(2)d and the worm biomass specific conversion rate was 0.5-1 g TSS sludge/g dry weight worms per day. The sludge reduction under optimal conditions in the worm reactor was 30-40%. The degradation by worms was an order of magnitude larger than the endogenous conversion rate of the secondary sludge. Effluent sludge from the worm reactor was stored in an anaerobic tank where methanogenic processes became apparent. It appeared that besides reducing the sludge amount, the worms' activity increased anaerobic digestibility, allowing for future optimisation of the total system by maximising sludge reduction and methane formation. In the whole system it was possible to reduce the amount of sludge by at least 65% on TSS basis. This is a much better total conversion than reported for anaerobic biodegradability of secondary sludge of 20-30% efficiency in terms of TSS reduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Goblet cell mucins as the selective barrier for the intestinal helminths: T-cell-independent alteration of goblet cell mucins by immunologically 'damaged' Nippostrongylus brasiliensis worms and its significance on the challenge infection with homologous and heterologous parasites.

PubMed Central

Ishikawa, N; Horii, Y; Oinuma, T; Suganuma, T; Nawa, Y

1994-01-01

The aim of this study was to examine the role of T cells on the alteration of terminal sugars of goblet cell mucins in the small intestinal mucosa of parasitized rats and to clarify the biological significance of the altered mucins in the mucosal defence against intestinal helminths. For this purpose, Nippostrongylus brasiliensis adult worms obtained from donor rats at 7 ('normal' worms) or 13 days ('damaged' worms) post-infection were implanted intraduodenally into euthymic and hypothymic (rnu/rnu) rats. Expulsion of implanted normal worms and associated goblet cell changes were extremely delayed in hypothymic recipients compared with euthymic recipients. In contrast, intraduodenally implanted damaged worms were expelled by day 5 regardless of the strains. Around the time of expulsion of implanted damaged worms, euthymic recipients showed both goblet cell hyperplasia and alteration of mucins, whereas hypothymic rats showed only the latter. Dexamethasone treatment completely abolished goblet cell changes of both strains of recipients. To clarify the importance of the constitutional changes of goblet cell mucins in mucosal defence, euthymic rats were primed by implantation of damaged worms to induce goblet cell changes, and then 3 or 5 days later they were challenged by implantation with normal worms. The results show that when goblet cell changes were induced by priming with damaged worms, recipient rats could completely prevent the establishment of normal worms. When hypothymic rats were primed and challenged in the same manner, a similar but slightly less preventive effect was observed. Such a protective effect of altered mucins seems to be selective because priming of euthymic rats with damaged N. brasiliensis did not affect the establishment of Strongyloides venezuelensis. These results suggest that: (1) once N. brasiliensis adult worms are 'damaged' by the host's T-cell-dependent immune mechanisms, they can induce alteration of sugar residues of goblet cell mucins via host-mediated, T-cell-independent processes; (2) the expression of such altered mucins is highly effective not only in causing expulsion of established damaged worms but also in preventing establishment of normal worms; and (3) the preventive effect of altered mucins is selective against parasite species. Images Figure 2 Figure 4 PMID:8206520

Edible peanut worm ( Sipunculus nudus) in the Beibu Gulf: Resource, aquaculture, ecological impact and counterplan

NASA Astrophysics Data System (ADS)

Li, Junwei; Xie, Xiaoyong; Zhu, Changbo; Guo, Yongjian; Chen, Suwen

2017-10-01

Sipunculus nudus is an important economic species because of its high nutritional and medicinal values. The exploitation and utilization of S. nudus primarily occur in the coastal regions of the Beibu Gulf. However, wild resource of S. nudus is rapidly decreasing because of the overexploitation, which has led to considerable developments of artificial breeding techniques. The cultivation scale of S. nudus has increased in response to successful artificial breeding; however, methods for culturing S. nudus in tidal flats or ponds require further study. Most studies have focused on the breeding, nutrition, medical value and ecological impact of these worms. Studies on the distribution, sediment requirements, nutrition characteristics, breeding techniques and aquaculture ecology of this species are summarized in this paper to promote the development of the aquaculture industry for S. nudus. The high biomass of S. nudus in the Beibu Gulf is positively correlated with the sediment characteristics and water quality of the region. The production of peanut worm has improved to some extent through culturing; however, the nutrient value and ecological environment problems have been observed, which reflect the over exploitation of trace elements and the sediment. These problems will worsen unless they are resolved, and the release of organic materials, nitrogen and phosphorus during harvesting impacts the coastal environment. Moreover, genetic erosion is a potential risk for larvae in artificial breeding programs in tidal flats. Therefore, culturing and collecting methods should be improved and the wild resource conservation should be implemented to promote the sustainable development of the peanut worm.

The occurrence of gizzard worms in Canada geese

USGS Publications Warehouse

Herman, C.M.; Wehr, E.E.

1954-01-01

Amidostomum anseris, a roundworm which occurs under the horny lining of the gizzard in birds, is a widely distributed parasite in Canada geese. It is also reported from snow geese (Chen hyperborea). Although the extent of erosion of the gizzard wall by these worms is not precisely correlated with the number of worms present, it is usually severe in Canada geese when 150 or more worms are present. Gizzard worm infection is considered a contributing factor to low weights, poor condition and to losses among the Canada geese which winter at the Pea Island National Wildlife Refuge in North Carolina. The mean number of gizzard worms per bird is considerably higher for Pea Island than for areas where winter losses have not been reported.

Himasthla alincia (Echinostomatidae): metacercariae in brackish water bivalves and their growth and development in experimental animals.

PubMed

Han, Eun-Taek; Whang, Jong-Dae; Chai, Jong-Yil

2009-12-01

Metacercariae of Himasthla alincia (Echinostomatidae) were discovered in brackish water bivalves in the Republic of Korea; their growth and development were observed in experimental animals. Five species of clams (Mactra veneriformis, Solen grandis, Meretrix petechialis, Cyclina sinensis, and Tapes philippinarum) were found to harbor the metacercariae of H. alincia. Chicks, rats, and mice were orally fed the metacercariae, and worms were recovered from their intestines from day 1 to day 20 postinfection (PI). Only chicks appeared to be a fairly suitable host, although the worm recovery was low, i.e., 1.5% from 17 chicks, and the number decreased from 2.6% on day 1 PI to 1.3% on day 20 PI. Worm development in chicks was quick and remarkable during days 10–20 PI. Adult flukes were morphologically characterized by the presence of a head collar with 31 dorsally uninterrupted collar spines, including 4 end-group spines, and distribution of vitellaria only up to the most posterior margin of the cirrus sac. We verified that several species of brackish water clams are second intermediate hosts for H. alincia, and that its life cycle occurs in the Republic of Korea.

Cuticular surface damage of Ascaridia galli adult worms treated with Veitchia merrillii betel nuts extract in vitro

PubMed Central

Balqis, Ummu; Hambal, Muhammad; Rinidar; Athaillah, Farida; Ismail; Azhar; Vanda, Henni; Darmawi

2017-01-01

Aim: The objective of this research was to in vitro evaluate the cuticular surface damage of Ascaridia galli adult worms treated with ethanolic extract of betel nuts Veitchia merrillii. Materials and Methods: Phytochemical screening was done using FeCl3, Wagner and Dragendorff reagents, NaOH, MgHCl, and Liebermann–Burchard reaction test. Amount of 16 worms were segregated into four groups with three replicates. Four worms of each group submerged into phosphate buffered saline, 25 mg/ml, and 75 mg/ml crude ethanolic extract of V. merrillii, and 15 mg/ml albendazole. The effect of these extract was observed 40 h after incubation as soon as worms death. The worms were sectioned transversally and were explored for any cuticular histopathological changes in their body surface under microscope. Results: We found that the ethanolic extract of V. merrillii betel nuts contains tannins, alkaloids, flavonoids, triterpenoids, and saponins. The ethanolic extract of betel nuts V. merrillii induces surface alterations caused cuticular damage of A. galli adult worms. Conclusion: We concluded that ethanolic extract of betel nuts V. merrillii possess anthelmintic activity caused cuticular damage of A. galli adult worms. PMID:28831213

Inequalities in body size among mermithid nematodes parasitizing earwigs.

PubMed

Maure, Fanny; Poulin, Robert

2016-12-01

Variation among body sizes of adult parasitic worms determines the relative genetic contribution of individuals to the next generation as it affects the effective parasite population size. Here, we investigate inequalities in body size and how they are affected by intensity of infection in Mermis nigrescens (Mermithidae: Nematoda) parasitizing the European earwig Forficula auricularia in New Zealand. Among a population of pre-adult worms prior to their emergence from the host, we observed only modest inequalities in body length; however, among worms sharing the same individual host, inequalities in body sizes decreased with increasing intensity of infection. Thus, the more worms occurred in a host, the more the second-longest, third-longest and even fourth-longest worms approached the longest worm in body length. This pattern, also known from another mermithid species, suggests that worms sharing the same host may have infected it roughly simultaneously, when the host encountered a clump of eggs in the environment. Thus, the life history and mode of infection of the parasite may explain the modest inequalities in the sizes achieved by pre-adult worms, which are lower than those reported for endoparasitic helminths of vertebrates.

Cross-disciplinary approaches for measuring parasitic helminth viability and phenotype.

PubMed

Peak, Emily; Hoffmann, Karl F

2011-06-01

Parasitic worms (helminths) within the Phyla Nematoda and Platyhelminthes are responsible for some of the most debilitating and chronic infectious diseases of human and animal populations across the globe. As no subunit vaccine for any parasitic helminth is close to being developed, the frontline strategy for intervention is administration of therapeutic, anthelmintic drugs. Worryingly, and unsurprising due to co-evolutionary mechanisms, many of these worms are developing resistance to the limited compound classes currently being used. This unfortunate reality has led to a renaissance in next generation anthelmintic discovery within both academic and industrial sectors. However, a major bottleneck in this process is the lack of quantitative methods for screening large numbers of small molecules for their effects on the whole organism. Development of methodologies that can objectively and rapidly distinguish helminth viability or phenotype would be an invaluable tool in the anthelmintic discovery pipeline. Towards this end, we describe how several basic techniques currently used to assess single cell eukaryote viability have been successfully applied to parasitic helminths. We additionally demonstrate how some of these methodologies have been adopted for high-throughput use and further modified for assessing worm phenotype. Continued development in this area is aimed at increasing the rate by which novel anthelmintics are identified and subsequently translated into everyday, practical applications.

A hybrid microfluidic device for on-demand orientation and multidirectional imaging of C. elegans organs and neurons

PubMed Central

Ardeshiri, Ramtin; Mulcahy, Ben; Zhen, Mei; Rezai, Pouya

2016-01-01

C. elegans is a well-known model organism in biology and neuroscience with a simple cellular (959 cells) and nervous (302 neurons) system and a relatively homologous (40%) genome to humans. Lateral and longitudinal manipulation of C. elegans to a favorable orientation is important in many applications such as neural and cellular imaging, laser ablation, microinjection, and electrophysiology. In this paper, we describe a micro-electro-fluidic device for on-demand manipulation of C. elegans and demonstrate its application in imaging of organs and neurons that cannot be visualized efficiently under natural orientation. To achieve this, we have used the electrotaxis technique to longitudinally orient the worm in a microchannel and then insert it into an orientation and imaging channel in which we integrated a rotatable glass capillary for orientation of the worm in any desired direction. The success rates of longitudinal and lateral orientations were 76% and 100%, respectively. We have demonstrated the application of our device in optical and fluorescent imaging of vulva, uterine-vulval cell (uv1), vulB1\\2 (adult vulval toroid cells), and ventral nerve cord of wild-type and mutant worms. In comparison to existing methods, the developed technique is capable of orienting the worm at any desired angle and maintaining the orientation while providing access to the worm for potential post-manipulation assays. This versatile tool can be potentially used in various applications such as neurobehavioral imaging, neuronal ablation, microinjection, and electrophysiology. PMID:27990213

From the genetic to the computer program: the historicity of 'data' and 'computation' in the investigations on the nematode worm C. elegans (1963-1998).

PubMed

García-Sancho, Miguel

2012-03-01

This paper argues that the history of the computer, of the practice of computation and of the notions of 'data' and 'programme' are essential for a critical account of the emergence and implications of data-driven research. In order to show this, I focus on the transition that the investigations on the worm C. elegans experienced in the Laboratory of Molecular Biology of Cambridge (UK). Throughout the 1980s, this research programme evolved from a study of the genetic basis of the worm's development and behaviour to a DNA mapping and sequencing initiative. By examining the changing computing technologies which were used at the Laboratory, I demonstrate that by the time of this transition researchers shifted from modelling the worm's genetic programme on a mainframe apparatus to writing minicomputer programs aimed at providing map and sequence data which was then circulated to other groups working on the genetics of C. elegans. The shift in the worm research should thus not be simply explained in the application of computers which transformed the project from hypothesis-driven to a data-intensive endeavour. The key factor was rather a historically specific technology-in-house and easy programmable minicomputers-which redefined the way of achieving the project's long-standing goal, leading the genetic programme to co-evolve with the practices of data production and distribution. Copyright © 2011 Elsevier Ltd. All rights reserved.

A new orthopteran-parasitizing horsehair worm, Acutogordius taiwanensis sp. n., with a redescription of Chordodes formosanus and novel host records from Taiwan (Nematomorpha, Gordiida)

PubMed Central

Chiu, Ming-Chung; Huang, Chin-Gi; Wu, Wen-Jer; Shiao, Shiuh-Feng

2017-01-01

Abstract A description of a new species of horsehair worm, Acutogordius taiwanensis sp. n., a redescription of Chordodes formosanus, and novel host records for the latter are provided. Acutogordius taiwanensis sp. n. is morphologically similar to A. protectus with moderately flat areoles on its tail tips, but is distinguishable by small mid-body ornamentations. Despite the distinct differences in the post-cloacal crescents between 14 male samples, their conspecific status, along with that of nine female samples, was upheld by a phylogenetic comparison of partial cytochrome oxidase subunit I (COI) sequences. Chordodes formosanus is another common horsehair worm species in Taiwan, which was previously believed to specifically parasitize Hierodula mantids. However, in this study, five C. formosanus were observed emerging from an Acromantis mantid, and two long-horned grasshopper hosts (Leptoteratura sp. and Holochlora japonica). These five worms showed high degrees of similarity in COI sequences and morphology, but one of these individuals bore abnormal crowned areoles, which has never been observed in C. formosanus, and may be attributed to the incomplete development of this particular individual. PMID:28824281

Studies on the diagnosis and treatment of human filariasis in Rhodesia.

PubMed

Goldsmid, J M; Rogers, S

1976-07-10

Experiences in Rhodesia with various recovery techniques available for the laboratory diagnosis of infections with Dipetalonema perstans and Wuchereria bancrofti are discussed. A diagnostic laboratory regimen for routine filarial investigations is suggested. Included are preliminary observations on the use of mebendazole (Vermox) for the treatment of D. perstans infections.

Shaking the Tree: Multi-locus Sequence Typing Usurps Current Onchocercid (Filarial Nematode) Phylogeny

PubMed Central

Lefoulon, Emilie; Bourret, Jérôme; Junker, Kerstin; Guerrero, Ricardo; Cañizales, Israel; Kuzmin, Yuriy; Satoto, Tri Baskoro T.; Cardenas-Callirgos, Jorge Manuel; de Souza Lima, Sueli; Raccurt, Christian; Mutafchiev, Yasen; Gavotte, Laurent; Martin, Coralie

2015-01-01

During the past twenty years, a number of molecular analyses have been performed to determine the evolutionary relationships of Onchocercidae, a family of filarial nematodes encompassing several species of medical or veterinary importance. However, opportunities for broad taxonomic sampling have been scarce, and analyses were based mainly on 12S rDNA and coxI gene sequences. While being suitable for species differentiation, these mitochondrial genes cannot be used to infer phylogenetic hypotheses at higher taxonomic levels. In the present study, 48 species, representing seven of eight subfamilies within the Onchocercidae, were sampled and sequences of seven gene loci (nuclear and mitochondrial) analysed, resulting in the hitherto largest molecular phylogenetic investigation into this family. Although our data support the current hypothesis that the Oswaldofilariinae, Waltonellinae and Icosiellinae subfamilies separated early from the remaining onchocercids, Setariinae was recovered as a well separated clade. Dirofilaria, Loxodontofilaria and Onchocerca constituted a strongly supported clade despite belonging to different subfamilies (Onchocercinae and Dirofilariinae). Finally, the separation between Splendidofilariinae, Dirofilariinae and Onchocercinae will have to be reconsidered. PMID:26588229

Molecular and phylogenetic analysis of the filarial nematode Micipsella numidica from the hare Lepus europaeus in Italy.

PubMed

Gabrielli, S; Galuppi, R; Fraulo, M; Savini, F; Morandi, B; Cancrini, G; Poglayen, G

2016-07-01

The genus Micipsella comprises three species of filariae to date identified in lagomorphs only, whereas the other genera belonging to the subfamily Splendidofilariinae are described as parasites of birds, reptiles and mammals. In the present study seven specimens of Micipsella numidica (Seurat, 1917), collected from the hare Lepus europaeus in Italy, were characterized genetically by molecular amplification of the mitochondrial genes (12S rDNA; cox1) and the 5S rDNA gene spacer region. Phylogenetic trees inferred using available sequences from filariae and those identified in this study evidenced a close relationship between M. numidica and Splendidofilariinae of other mammals and reptiles (Rumenfilaria andersoni and Madathamugadia hiepei). The present findings, apart from adding new data about the hosts in Italy, support the taxonomic position of M. numidica and highlight the substantial biological and molecular differences existing between Splendidofilariinae and other Onchocercidae. The study also contributes to our knowledge of the molecular/genetic diagnosis of filarial parasites of veterinary and medical concern in any vertebrate or invertebrate host.

Myeloid cell recruitment versus local proliferation differentiates susceptibility from resistance to filarial infection

PubMed Central

Campbell, Sharon M; Knipper, Johanna A; Ruckerl, Dominik; Finlay, Conor M; Logan, Nicola; Minutti, Carlos M; Mack, Matthias; Jenkins, Stephen J; Taylor, Matthew D

2018-01-01

Both TH2-dependent helminth killing and suppression of the TH2 effector response have been attributed to macrophages (MΦ) activated by IL-4 (M(IL-4)). To investigate how M(IL-4) contribute to diverse infection outcomes, the MΦ compartment of susceptible BALB/c mice and more resistant C57BL/6 mice was profiled during infection of the pleural cavity with the filarial nematode, Litomosoides sigmodontis. C57BL/6 mice exhibited a profoundly expanded resident MΦ (resMΦ) population, which was gradually replenished from the bone marrow in an age-dependent manner. Infection status did not alter the bone-marrow derived contribution to the resMΦ population, confirming local proliferation as the driver of resMΦ expansion. Significantly less resMΦ expansion was observed in the susceptible BALB/c strain, which instead exhibited an influx of monocytes that assumed an immunosuppressive PD-L2+ phenotype. Inhibition of monocyte recruitment enhanced nematode killing. Thus, the balance of monocytic vs. resident M(IL-4) numbers varies between inbred mouse strains and impacts infection outcome. PMID:29299998

Worms--a "license to kill".

PubMed

Kaminsky, Ronald; Rufener, Lucien; Bouvier, Jacques; Lizundia, Regina; Schorderet Weber, Sandra; Sager, Heinz

2013-08-01

Worm infections can cause severe harm and death to both humans and numerous domestic and wild animals. Despite the fact that there are many beneficial worm species, veterinarians, physicians and parasitologists have multiple reasons to combat parasitic worms. The pros and cons of various approaches for the discovery of new control methods are discussed, including novel anthelmintics, vaccines and genetic approaches to identify novel drug and vaccine targets. Currently, the mainstay of worm control remains chemotherapy and prophylaxis. The importance of knowledgeable and wise use of the available anthelmintics is highlighted. Copyright © 2013 Elsevier B.V. All rights reserved.

Periorbital dirofilariasis—Clinical and imaging findings: Live worm on ultrasound

PubMed Central

Gopinath, Thandre N; Lakshmi, K P; Shaji, P C; Rajalakshmi, P C

2013-01-01

Ocular dirofilariasis is a zoonotic filariasis caused by nematode worm,Dirofilaria. We present a case of dirofilariasis affecting the upper eyelid in a 2-year-old child presenting as an acutely inflammed cyst, from southern Indian state of Kerala. Live adult worm was surgically removed and confirmed to be Dirofilaria repens. Live worm showing continuous movement was seen on the pre-operative high-resolution ultrasound. Ultrasound can be helpful in pre-operative identification of live worm. Imaging findings reported in literature are very few. We describe the clinical, ultrasound, and magnetic resonance imaging (MRI) findings. PMID:23803483

Development and chromosome mechanics in nematodes: Results from IML-1

NASA Technical Reports Server (NTRS)

Nelson, G. A.; Schubert, W. W.; Kazarians, G. A.; Richards, G. F.

1994-01-01

A subset of the Caenorhabditis elegans nematodes flown aboard Biorack on IML-1 was analyzed for the fidelity of development and the mechanics of chromosomes at meiosis. To assess meiosis, mutant worms marked at two linked or unlinked loci were inoculated as heterozygous hermaphrodites and allowed to self fertilize. Mendelian segregation ratios and recombination frequency were measured for offspring produced at 1XG or in microgravity. To assess development, worms and embryos were fixed and stained with the DNA dye, Diamidinophenolindole (DAPI), or antibodies specific for antigens expressed in germ cells, pharyngeal and body wall muscles, and gut cells. The distribution of cytoplasmic determinants, cell nuclei counts and positions were scored to assess symmetry relations and anatomical features.

Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

PubMed

Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

2017-10-01

Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against parasitic gut worms of frogs, but these effects depend on the stage of the host and infection, respectively. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Worm Gear With Hydrostatic Engagement

NASA Technical Reports Server (NTRS)

Chaiko, Lev I.

1994-01-01

In proposed worm-gear transmission, oil pumped at high pressure through meshes between teeth of gear and worm coil. Pressure in oil separates meshing surfaces slightly, and oil reduces friction between surfaces. Conceived for use in drive train between gas-turbine engine and rotor of helicopter. Useful in other applications in which weight critical. Test apparatus simulates and measures some loading conditions of proposed worm gear with hydrostatic engagement.

Formation of Worm-Like Micelles in Mixed N-Hexadecyl-N-Methylpyrrolidinium Bromide-Based Cationic Surfactant and Anionic Surfactant Systems

PubMed Central

Dai, Caili; Yan, Zhihu; You, Qing; Du, Mingyong; Zhao, Mingwei

2014-01-01

Through the descriptive and rheological characterization of worm-like micelles formed by N-hexadecyl-N-methylpyrrolidinium bromide and sodium laurate, the formation and properties of the worm-like micelles were affected by the concentrations of sodium laurate and temperature. Additionally, cryogenic transmission electron microscopy images further validated the formation of worm-like micelles. PMID:25019152

Worm Burden-Dependent Disruption of the Porcine Colon Microbiota by Trichuris suis Infection

PubMed Central

Wu, Sitao; Li, Robert W.; Li, Weizhong; Beshah, Ethiopia; Dawson, Harry D.; Urban, Joseph F.

2012-01-01

Helminth infection in pigs serves as an excellent model for the study of the interaction between human malnutrition and parasitic infection and could have important implications in human health. We had observed that pigs infected with Trichuris suis for 21 days showed significant changes in the proximal colon microbiota. In this study, interactions between worm burden and severity of disruptions to the microbial composition and metabolic potentials in the porcine proximal colon microbiota were investigated using metagenomic tools. Pigs were infected by a single dose of T. suis eggs for 53 days. Among infected pigs, two cohorts were differentiated that either had adult worms or were worm-free. Infection resulted in a significant change in the abundance of approximately 13% of genera detected in the proximal colon microbiota regardless of worm status, suggesting a relatively persistent change over time in the microbiota due to the initial infection. A significant reduction in the abundance of Fibrobacter and Ruminococcus indicated a change in the fibrolytic capacity of the colon microbiota in T. suis infected pigs. In addition, ∼10% of identified KEGG pathways were affected by infection, including ABC transporters, peptidoglycan biosynthesis, and lipopolysaccharide biosynthesis as well as α-linolenic acid metabolism. Trichuris suis infection modulated host immunity to Campylobacter because there was a 3-fold increase in the relative abundance in the colon microbiota of infected pigs with worms compared to naïve controls, but a 3-fold reduction in worm-free infected pigs compared to controls. The level of pathology observed in infected pigs with worms compared to worm-free infected pigs may relate to the local host response because expression of several Th2-related genes were enhanced in infected pigs with worms versus those worm-free. Our findings provided insight into the dynamics of the proximal colon microbiota in pigs in response to T. suis infection. PMID:22532855

Fourier-Based Diffraction Analysis of Live Caenorhabditis elegans.

PubMed

Magnes, Jenny; Hastings, Harold M; Raley-Susman, Kathleen M; Alivisatos, Clara; Warner, Adam; Hulsey-Vincent, Miranda

2017-09-13

This manuscript describes how to classify nematodes using temporal far-field diffraction signatures. A single C. elegans is suspended in a water column inside an optical cuvette. A 632 nm continuous wave HeNe laser is directed through the cuvette using front surface mirrors. A significant distance of at least 20-30 cm traveled after the light passes through the cuvette ensures a useful far-field (Fraunhofer) diffraction pattern. The diffraction pattern changes in real time as the nematode swims within the laser beam. The photodiode is placed off-center in the diffraction pattern. The voltage signal from the photodiode is observed in real time and recorded using a digital oscilloscope. This process is repeated for 139 wild type and 108 "roller" C. elegans. Wild type worms exhibit a rapid oscillation pattern in solution. The "roller" worms have a mutation in a key component of the cuticle that interferes with smooth locomotion. Time intervals that are not free of saturation and inactivity are discarded. It is practical to divide each average by its maximum to compare relative intensities. The signal for each worm is Fourier transformed so that the frequency pattern for each worm emerges. The signal for each type of worm is averaged. The averaged Fourier spectra for the wild type and the "roller" C. elegans are distinctly different and reveal that the dynamic worm shapes of the two different worm strains can be distinguished using Fourier analysis. The Fourier spectra of each worm strain match an approximate model using two different binary worm shapes that correspond to locomotory moments. The envelope of the averaged frequency distribution for actual and modeled worms confirms the model matches the data. This method can serve as a baseline for Fourier analysis for many microscopic species, as every microorganism will have its unique Fourier spectrum.

Value-Range Analysis of C Programs

NASA Astrophysics Data System (ADS)

Simon, Axel

In 1988, Robert T. Morris exploited a so-called buffer-overflow bug in finger (a dæmon whose job it is to return information on local users) to mount a denial-of-service attack on hundreds of VAX and Sun-3 computers [159]. He created what is nowadays called a worm; that is, a crafted stream of bytes that, when sent to a computer over the network, utilises a buffer-overflow bug in the software of that computer to execute code encoded in the byte stream. In the case of a worm, this code will send the very same byte stream to other computers on the network, thereby creating an avalanche of network traffic that ultimately renders the network and all computers involved in replicating the worm inaccessible. Besides duplicating themselves, worms can alter data on the host that they are running on. The most famous example in recent years was the MSBlaster32 worm, which altered the configuration database on many Microsoft Windows machines, thereby forcing the computers to reboot incessantly. Although this worm was rather benign, it caused huge damage to businesses who were unable to use their IT infrastructure for hours or even days after the appearance of the worm. A more malicious worm is certainly conceivable [187] due to the fact that worms are executed as part of a dæmon (also known as "service" on Windows machines) and thereby run at a privileged level, allowing access to any data stored on the remote computer. While the deletion of data presents a looming threat to valuable information, even more serious uses are espionage and theft, in particular because worms do not have to affect the running system and hence may be impossible to detect.

Mobile Transactional Modelling: From Concepts to Incremental Knowledge

NASA Astrophysics Data System (ADS)

Launders, Ivan; Polovina, Simon; Hill, Richard

In 1988, Robert T. Morris exploited a so-called buffer-overflow bug in finger (a dæmon whose job it is to return information on local users) to mount a denial-of-service attack on hundreds of VAX and Sun-3 computers [159]. He created what is nowadays called a worm; that is, a crafted stream of bytes that, when sent to a computer over the network, utilises a buffer-overflow bug in the software of that computer to execute code encoded in the byte stream. In the case of a worm, this code will send the very same byte stream to other computers on the network, thereby creating an avalanche of network traffic that ultimately renders the network and all computers involved in replicating the worm inaccessible. Besides duplicating themselves, worms can alter data on the host that they are running on. The most famous example in recent years was the MSBlaster32 worm, which altered the configuration database on many Microsoft Windows machines, thereby forcing the computers to reboot incessantly. Although this worm was rather benign, it caused huge damage to businesses who were unable to use their IT infrastructure for hours or even days after the appearance of the worm. A more malicious worm is certainly conceivable [187] due to the fact that worms are executed as part of a dæmon (also known as "service" on Windows machines) and thereby run at a privileged level, allowing access to any data stored on the remote computer. While the deletion of data presents a looming threat to valuable information, even more serious uses are espionage and theft, in particular because worms do not have to affect the running system and hence may be impossible to detect.

Presence of ecto-protein tyrosine phosphatase activity is vital for survival of Setaria cervi, a bovine filarial parasite.

PubMed

Singh, Neetu; Heneberg, Petr; Rathaur, Sushma

2014-10-01

The ecto protein tyrosine phosphatases (PTP) are known to play a crucial role in the pathogenesis and survival of the intracellular parasites. However, their presence and role in filarial parasites is still unknown. We found a significant amount of tyrosine phosphatase activity in the surface antigen fraction extracted from Setaria cervi (S. cervi), a bovine filarial parasite. An antibody designed against the conserved catalytic core of human protein tyrosine phosphatases, PTP1B cross reacted with a 63 kDa band in the surface antigen. We detected a significant amount of PTP activity in the intact S. cervi adult parasites as well as microfilariae in this study for the first time. This PTP may be localized on the surface of the parasite with an exposed active site available for the external substrates. The PTP activity was also inhibited by sodium orthovanadate and phenyl arsine oxide, specific inhibitors of PTP in both the life stages. The Km and Vmax for PTP in the adult parasites and microfilariae were determined to be 2.574 ± 0.14 mM; 206.3 ± 2.75 μM Pi/h/two parasites and 5.510 ± 0.59 mM; 62.27 ± 2.27 μM Pi/h/10(6) parasites respectively using O-P-L-Tyrosine as substrate. Interestingly, a positive correlation was observed between the inhibition in PTP activity and reduction in the motility/ viability of the parasites when they were subjected to the specific PTP inhibitors (Orthovanadate and Phenyl arsine oxide) for 4 h in the KRB maintenance medium. The activity was also significantly inhibited in the parasites exposed to antifilarial drug/compounds for e.g. Diethylcarbamazine, Acetylsalicylic Acid and SK7, a methyl chalcone. Therefore suggesting a possible role played by PTP in the survival of the parasite, its interaction with the host as well as in the screening of newly synthesized antifilarials/drugs.

Immune response in Mansonella ozzardi infection modulated by IL-6/IL-10 axis in Amazon region of Brazil.

PubMed

Costa, Allyson Guimarães; Sadahiro, Aya; Monteiro Tarragô, Andréa; Pessoa, Felipe Arley Costa; Pires Loiola, Bruna; Malheiro, Adriana; Medeiros, Jansen Fernandes

2018-04-01

Mansonellosis is an endemic disease in the South and Central America. In Brazil, one of the etiological agents is Mansonella ozzardi. This filarial infection is yet poorly understood, with a controversial morbity, presenting since a oligosymptoms, malaria-like signs or without complaint in humans. The knowledge of the human immune response to microfilariae infection is limited mainly by different evolutionary cycles of the parasite in the host. In addition, the prevalence of this filarial parasite infection is high in several regions of Amazonas State. A cross-sectional study was conducted in an endemic area for microfilariae of M. ozzardi (MF) infection in the Amazonas State, Brazil. Proinflammatory and regulatory cytokines (IL-2, IL-4, IL-6, IL-10, TNF, IFN-gamma, and IL-17A) were measured in cryopreserved serum using the Cytometric Bead Array techniques (CBA) in 54 patients diagnosed with M. ozzardi infection and 55 individuals without the infection were included in the study (Controls). The IL-4, IL-6 and IL-10 level increased in infected patients with MF infection, while IL-17A increased in control only. When we compared controls to patients with high or low parasite load, the increased level of IL-6 and IL-10 were maintained. IL-6 contributes to the proinflammatory activity and IL-10 modulates Th1, Th2 and Th17 immune response. Furthermore, IL-4 was detected as a marker in the MF infection and MF patients with low parasite load, indicating the action of the Th2 cell response. The complex network of cytokines acting during M. ozzardi infection depends on a fine balance to determine a host protective effect or filarial persistence. Therefore, these results suggest that the immune response in MF infection is modulated by IL-6/IL-10 axis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Helminth Infections Coincident with Active Pulmonary Tuberculosis Inhibit Mono- and Multifunctional CD4+ and CD8+ T Cell Responses in a Process Dependent on IL-10

PubMed Central

George, Parakkal Jovvian; Anuradha, Rajamanickam; Kumar, Nathella Pavan; Sridhar, Rathinam; Banurekha, Vaithilingam V.; Nutman, Thomas B.; Babu, Subash

2014-01-01

Tissue invasive helminth infections and tuberculosis (TB) are co-endemic in many parts of the world and can trigger immune responses that might antagonize each other. We have previously shown that helminth infections modulate the Th1 and Th17 responses to mycobacterial-antigens in latent TB. To determine whether helminth infections modulate antigen-specific and non-specific immune responses in active pulmonary TB, we examined CD4+ and CD8+ T cell responses as well as the systemic (plasma) cytokine levels in individuals with pulmonary TB with or without two distinct helminth infections—Wuchereria bancrofti and Strongyloides stercoralis infection. By analyzing the frequencies of Th1 and Th17 CD4+ and CD8+ T cells and their component subsets (including multifunctional cells), we report a significant diminution in the mycobacterial–specific frequencies of mono- and multi–functional CD4+ Th1 and (to a lesser extent) Th17 cells when concomitant filarial or Strongyloides infection occurs. The impairment in CD4+ and CD8+ T cell cytokine responses was antigen-specific as polyclonal activated T cell frequencies were equivalent irrespective of helminth infection status. This diminution in T cell responses was also reflected in diminished circulating levels of Th1 (IFN-γ, TNF-α and IL-2)- and Th17 (IL-17A and IL-17F)-associated cytokines. Finally, we demonstrate that for the filarial co-infections at least, this diminished frequency of multifunctional CD4+ T cell responses was partially dependent on IL-10 as IL-10 blockade significantly increased the frequencies of CD4+ Th1 cells. Thus, co-existent helminth infection is associated with an IL-10 mediated (for filarial infection) profound inhibition of antigen-specific CD4+ T cell responses as well as protective systemic cytokine responses in active pulmonary TB. PMID:25211342

Filarial Abundant Larval Transcript Protein ALT-2: An Immunomodulatory Therapeutic Agent for Type 1 Diabetes.

PubMed

Reddy, Sridhar M; Reddy, Pooja M; Amdare, Nitin; Khatri, Vishal; Tarnekar, Aaditya; Goswami, Kalyan; Reddy, Maryada Venkata Rami

2017-03-01

Type 1 diabetes (T1D) that accounts for about 5-10 % of all diabetes cases results from the autoimmune destruction of the insulin-producing beta cells in the pancreas. It is characterized by severe inflammatory reaction mediated by pronounced T helper type-1 response. Parasitic infections having the ability to skew the host immune responses towards type-2 type as a part of their defense mechanism are able to induce protection against autoimmune diseases like T1D. Hence, the present study is undertaken to explore a recombinant abundant larval transcript protein of the human lymphatic filarial parasite Brugia malayi ( rBm ALT-2), a known anti-inflammatory molecule for its therapeutic effect on streptozotocin (STZ)-induced T1D in mice. The diabetic mice on treatment with r Bm ALT-2 showed a significant ( p  < 0.0005) decrease in their fasting blood glucose levels. By the end of the second week after the initiation of treatment with the r Bm ALT-2, 28 % of the diabetic mice became normal and none of them were diabetic by the end of 5th week. The anti-diabetic effect of r Bm ALT-2 significantly correlated with the concomitant redressal of the pancreatic histopathological damage caused by STZ assault (rho = 0.87; p  < 0.0005). The sera of r Bm ALT-2 treated diabetic mice had increased levels of IgG1 antibodies associated with decreased IgG2a antibodies against the principal autoantigen insulin. The splenocyte proliferative response and the cytokine release in the treated mice showed marked bias against inflammation skewing the immune response to Th-2 type. From this study, it can be envisaged that that filarial proteins like r Bm ALT-2 with effective immunomodulatory activity and anti-diabetic effect are promising alternative therapeutic agents for T1D.

An unidentified filarial species and its impact on fitness in wild populations of the black-footed ferret (Mustela nigripes).

PubMed

Wisely, Samantha M; Howard, JoGayle; Williams, Steven A; Bain, Odile; Santymire, Rachel M; Bardsley, Katherine D; Williams, Elizabeth S

2008-01-01

Disease can threaten the restoration of endangered species directly by substantially decreasing host survival or indirectly via incremental decreases in survival and reproduction. During a biomedical survey of reintroduced populations of the highly endangered black-footed ferret from 2002 to 2005, microfilariae discovered in the blood were putatively identified as Dirofilaria immitis, and widespread screening was initiated using a commercially available antigen-based ELISA test. A subset of animals (n = 16) was screened for D. immitis using a highly sensitive PCR-based assay. Microfilariae were also molecularly and morphologically characterized. Of 198 animals at six reintroduction sites, 12% had positive results using the ELISA test. No antigen-positive animals which were screened via PCR (n = 11) had positive PCR results, and all antigen-positive animals (n = 24) were asymptomatic. No significant differences were found in body mass of antigen-positive (male: 1223 +/- 82 g [mean +/- SD], female: 726 +/- 75 g) vs. antigen-negative (male: 1,198 +/- 119 g, female: 710 +/- 53 g) individuals (P = 0.4). Antigen prevalence was lower in juveniles (3%) than adults (12%; P = 0.03), and higher in in situ, captive-reared individuals (33%) than wild-born individuals (10%; P = 0.005). Morphologic analysis of microfilariae revealed they were neither D. immitis nor any other previously characterized North American species. PCR amplification of the 5S spacer region of rDNA revealed that the filarial sequence shared only 76% identity with D. immitis. This previously unidentified filarial sequence was present in all antigen positive animals (11 of 11 tested). It appears that black-footed ferrets were infected with a previously undescribed species of filaria whose antigen cross-reacted with the ELISA assay, although further analysis is needed to make a conclusive statement. Nonetheless, this previously undescribed filaria does not appear to threaten recovery for this highly endangered mammal.

Wandering ascaris coming out through the abdominal wall.

PubMed

Wani, Mohd L; Rather, Ajaz A; Parray, Fazl Q; Ahangar, Abdul G; Bijli, Akram H; Irshad, Ifat; Nayeem-Ul-Hassan; Khan, Tahir S

2013-06-01

A rare case of ascaris coming out through the anterior abdominal wall is reported here. A 40-year-old female had undergone dilatation and curettage by a quack. On the second day she presented with presented with features of peritonitis. She was explored. Resection anastomosis of the ileum was done for multiple perforations of the ileum. Patient developed a fistula in the anterior abdominal wall which was draining bile-colored fluid. On the 12(th) postoperative day a 10-cm-long worm was seen coming out through the fistulous tract which was found to be Ascaris lumbricoids. Ascaris lumbricoids can lead to many complications ranging from worm colic to intestinal obstruction, volvulus, peritonitis, pancreatitis, cholangiohepatitis, liver abscess and many more. Worm has been reported to come out through mouth, nostrils, abdominal drains, T-tubes etc. But ascaris coming out through the anterior abdominal wall is very rare hence reported here.

Wandering Ascaris Coming Out Through the Abdominal Wall

PubMed Central

Wani, Mohd L; Rather, Ajaz A.; Parray, Fazl Q.; Ahangar, Abdul G.; Bijli, Akram H.; Irshad, Ifat; Nayeem-Ul-Hassan; Khan, Tahir S.

2013-01-01

A rare case of ascaris coming out through the anterior abdominal wall is reported here. A 40-year-old female had undergone dilatation and curettage by a quack. On the second day she presented with presented with features of peritonitis. She was explored. Resection anastomosis of the ileum was done for multiple perforations of the ileum. Patient developed a fistula in the anterior abdominal wall which was draining bile-colored fluid. On the 12th postoperative day a 10-cm-long worm was seen coming out through the fistulous tract which was found to be Ascaris lumbricoids. Ascaris lumbricoids can lead to many complications ranging from worm colic to intestinal obstruction, volvulus, peritonitis, pancreatitis, cholangiohepatitis, liver abscess and many more. Worm has been reported to come out through mouth, nostrils, abdominal drains, T-tubes etc. But ascaris coming out through the anterior abdominal wall is very rare hence reported here. PMID:23930192

Effects of Lactobacillus salivarius, Lactobacillus reuteri, and Pediococcus acidilactici on the nematode Caenorhabditis elegans include possible antitumor activity.

PubMed

Fasseas, Michael K; Fasseas, Costas; Mountzouris, Konstantinos C; Syntichaki, Popi

2013-03-01

This study examined the effects of three lactic acid bacteria (LAB) strains on the nematode Caenorhabditis elegans. Lactobacillus salivarius, Lactobacillus reuteri, and Pediococcus acidilactici were found to inhibit the development and growth of the worm. Compared to Escherichia coli used as the control, L. reuteri and P. acidilactici reduced the lifespan of wild-type and short-lived daf-16 worms. On the contrary, L. salivarius extended the lifespan of daf-16 worms when used live, but reduced it as UV-killed bacteria. The three LAB induced the expression of genes involved in pathogen response and inhibited the growth of tumor-like germ cells, without affecting DAF16 localization or increasing corpse cells. Our results suggest the possible use of C. elegans as a model for studying the antitumor attributes of LAB. The negative effects of these LAB strains on the nematode also indicate their potential use against parasitic nematodes.

Representation matters: quantitative behavioral variation in wild worm strains

NASA Astrophysics Data System (ADS)

Brown, Andre

Natural genetic variation in populations is the basis of genome-wide association studies, an approach that has been applied in large studies of humans to study the genetic architecture of complex traits including disease risk. Of course, the traits you choose to measure determine which associated genes you discover (or miss). In large-scale human studies, the measured traits are usually taken as a given during the association step because they are expensive to collect and standardize. Working with the nematode worm C. elegans, we do not have the same constraints. In this talk I will describe how large-scale imaging of worm behavior allows us to develop alternative representations of behavior that vary differently across wild populations. The alternative representations yield novel traits that can be used for genome-wide association studies and may reveal basic properties of the genotype-phenotype map that are obscured if only a small set of fixed traits are used.

Tracking C. elegans and its neuromuscular activity using NemaFlex II

NASA Astrophysics Data System (ADS)

van Bussel, Frank; Rahman, Mizanur; Blawzdziewicz, Jerzy; Vanapalli, Siva

NemaFlex is a recently developed experimental platform designed to analyze the movement and muscular strength of crawling C. elegans. Physically it is a microfluidic device consisting of an array of deformable PDMS pillars, with which the C. elegans interacts in the course of moving through the system; image data is then acquired through a transparent top plate. The software component uses this image data to track the worm's movements and measure pillar deflections and thereby the forces exerted by the worm, in a fully automated, high-throughput manner. In order to correlate the force results with muscle activations the pillar deflections need to be precisely associated with mechanical contact on the worm's body, which requires accurate determination and representation of the body's position within the complex background. Here we discuss issues encountered in extracting this position data from the surrounding environment.

Gastrointestinal helminthiasis presenting with acute diarrhoea and constipation: report of two cases with a second pathology.

PubMed

Sobani, Z A; Shakoor, S; Malik, F N; Malik, E Z; Beg, M A

2010-08-01

Gastrointestinal helminthiasis in developing countries contributes to malnutrition and anemia. Diagnosis and treatment of helminthiasis, especially with low worm load is an unmet public health need in such settings. The infection may sometimes become manifest when a second pathology leads to purgation of the gastrointestinal tract. Two cases of helminthiasis are presented in which the infections only became amenable to diagnosis due to acute diarrhoea caused by giardiasis and lactulose administration. In the first case, acute giardiasis revealed Ascaris lumbricoides infestation, and in the second case primary helminthiasis (strongyloidiasis) was revealed by lactulose, and also led to Vibrio cholera bacteremia. These cases highlight the need to diagnose helminth infestations especially with low worm burdens by means of public health surveillance programmes. These cases highlight the need to diagnose helminth infestations especially with low worm burdens by means of public health surveillance programmes.

IMMUNIZATION IN SCHISTOSOMIASIS BY PREVIOUS EXPOSURE TO HOMOLOGOUS AND HETEROLOGOUS CERCARIAE BY INOCULATION OF PREPARATIONS FROM SCHISTOSOMES AND BY EXPOSURE TO IRRADIATED CERCARIAE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadun, E.H.

1963-12-30

A review on immmnization in schistosomiasis indicates that immunization is certainly possible. Mice can be protected much more readily against S. japonicum than against S. mansoni. However, the Rhesus monkeys develop an acquired resistance to S. mansoni. Rats can also be easily protected with worm homogenates of S. mansoni. It has also been observed that a previous exposure to a Formosan heterologous strain of S. japonicum induced a greater degree of resistance than exposures to the Japanese homologous strains. The least significant degree of acquired immunity is induced by vaccination with worm homogenates or worm products and with the transfermore » of serum from immune to normal animals. It was also indicated that exposure of monkeys to irradiated cercariae induced a marked resistance to a subsequent challenge of nonattenuated cercaria of S. mansoni. 67 references are included. (P.C.H.)« less

Effects of the novel anthelmintic emodepside on the locomotion, egg-laying behaviour and development of Caenorhabditis elegans.

PubMed

Bull, Kathryn; Cook, Alan; Hopper, Neil A; Harder, Achim; Holden-Dye, Lindy; Walker, Robert J

2007-05-01

Emodepside, a cyclooctadepsipeptide, is a broad-spectrum anthelmintic previously shown to paralyse body wall muscle and pharyngeal muscle in the model nematode Caenorhabditis elegans. We demonstrate that wild-type C. elegans L4 are less sensitive than adults to emodepside in two independent assays of locomotor behaviour: body bend generation on agar (adult IC(50) 3.7 nM, L4 IC(50) 13.4 nM) and thrashing behaviour in liquid (thrashing behaviour as a % of controls after 1h in 10 microM emodepside: adults 16%, L4 worms 48%). We also show that continuous exposure of wild-type C. elegans to emodepside throughout the life-cycle from egg onwards, slows worm development, an effect that is emodepside concentration-dependent. The rate of worm-hatching from eggs on agar plates containing emodepside was not significantly different from controls, suggesting that it is development post-hatching rather than hatching itself that is affected by the drug. Emodepside also inhibits wild-type C. elegans egg-laying, with acute exposure to the drug at 500 nM resulting in an almost total inhibition within the first hour. However, the rate of egg production was not inhibited and therefore emodepside-treated worms became bloated with eggs, eventually rupturing. This suggests that the effect of emodepside on reproduction is not due to an inhibition of egg production but rather a paralytic effect on the egg-laying muscles. These results, when coupled with previous research, suggest that emodepside interferes with signalling at the neuromuscular junction on the body-wall muscles (Willson et al., 2003), pharynx (Willson et al., 2004) and egg-laying muscles and thus inhibits three important physiological functions: locomotion, feeding and reproduction.

A genetic analysis of Trichuris trichiura and Trichuris suis from Ecuador.

PubMed

Meekums, Hayley; Hawash, Mohamed B F; Sparks, Alexandra M; Oviedo, Yisela; Sandoval, Carlos; Chico, Martha E; Stothard, J Russell; Cooper, Philip J; Nejsum, Peter; Betson, Martha

2015-03-19

Since the nematodes Trichuris trichiura and T. suis are morphologically indistinguishable, genetic analysis is required to assess epidemiological cross-over between people and pigs. This study aimed to clarify the transmission biology of trichuriasis in Ecuador. Adult Trichuris worms were collected during a parasitological survey of 132 people and 46 pigs in Esmeraldas Province, Ecuador. Morphometric analysis of 49 pig worms and 64 human worms revealed significant variation. In discriminant analysis morphometric characteristics correctly classified male worms according to host species. In PCR-RFLP analysis of the ribosomal Internal Transcribed Spacer (ITS-2) and 18S DNA (59 pig worms and 82 human worms), nearly all Trichuris exhibited expected restriction patterns. However, two pig-derived worms showed a "heterozygous-type" ITS-2 pattern, with one also having a "heterozygous-type" 18S pattern. Phylogenetic analysis of the mitochondrial large ribosomal subunit partitioned worms by host species. Notably, some Ecuadorian T. suis clustered with porcine Trichuris from USA and Denmark and some with Chinese T. suis. This is the first study in Latin America to genetically analyse Trichuris parasites. Although T. trichiura does not appear to be zoonotic in Ecuador, there is evidence of genetic exchange between T. trichiura and T. suis warranting more detailed genetic sampling.

[Chronobiological studies on effect of cyclosporin A (CsA) against adult male worms of Schistosoma mansoni in vitro].

PubMed

Liu, J; Chappell, L H

1998-01-01

To study the action mode of cyclosporin A (CsA) against Schistosoma mansoni in vitro. MF1 mice were infected with Schistosoma mansoni cercariae for 6 weeks when the adult worms were recovered by portal perfusion. The male worms of S. mansoni recovered were exposed to varying concentrations of CsA at 8, 16, and 24 h in vitro. Drug induced damage to the male worm surface was chrono-biologically observed throughout these experiments by SEM. After the male worms of S. mansoni were incubated with 1 microgram/ml CsA for 8-24 h, the tegument showed swelling of ridges with appearance of holes on their surface and detachment of a part of spines. The above damage of the tegument became more evident in male worms after incubation with 10, 15, 20 micrograms/ml CsA for 8-24 h. Moreover, incubation of male worms with 25 micrograms/ml CsA for 8-24 h resulted in significant deformation and disruption of tegument, rupture of ridges and detachment of spines. The tegumental damage of male worms of S. mansoni was dose- and time-dependent. The antischistosomal action of CsA is direct, the schistosome tegument appears to be the main site for CsA attack.

Improved Perceptions and Practices Related to Schistosomiasis and Intestinal Worm Infections Following PHAST Intervention on Kome Island, North-Western Tanzania.

PubMed

Mwanga, Joseph R; Kaatano, Godfrey M; Siza, Julius E; Chang, Su Young; Ko, Yunsuk; Kullaya, Cyril M; Nsabo, Jackson; Eom, Keeseon S; Yong, Tai-Soon; Chai, Jong-Yil; Min, Duk-Young; Rim, Han-Jong; Changalucha, John M

2015-10-01

Schistosomiasis and intestinal worm infections are widespread diseases of public health importance in Tanzania. A study on perceptions and practices related to schistosomiasis and intestinal worm infections was undertaken among a community population of Kome Island in Sengerema District, north-western Tanzania, where intestinal schistosomiasis and intestinal worm infections are endemic. Schistosomiasis and intestinal worm-related perceptions and practices were assessed before and 3 years after implementation of a participatory hygiene and sanitation transformation (PHAST) intervention as a control measure. Data were obtained from baseline and post-intervention knowledge, attitudes, and practices (KAP) questionnaire surveys conducted twice in 2009 and 2012 among 82 individuals aged ≥15 years. We found significant increases in respondents' knowledge of the cause, transmission, symptoms, health consequences, and prevention of schistosomiasis and intestinal worm infections after PHAST intervention. The increase in respondents' knowledge on almost all aspects of the said infections was translated into actions to control schistosomiasis and intestinal worm infections. This has not been achieved by chance, but due to well-designed and locally-adapted PHAST intervention. We conclude that despite criticisms, PHAST approach is still useful in empowering communities to control water, sanitation, and hygiene related infectious diseases such as schistosomiasis and intestinal worm infections.

Effects of Microtus fortis lymphocytes on Schistosoma japonicum in a bone marrow transplantation model.

PubMed

Hu, Yuan; Xu, Yuxin; Lu, Weiyuan; Quan, Hong; Shen, Yujuan; Yuan, Zhongying; Zhang, Jing; Zang, Wei; He, Yongkang; Cao, Jianping

2014-07-01

Microtus fortis is a non-permissive host for Schistosoma japonicum. While M. fortis lymphocytes are known to provide natural resistance against S. japonicum, the specific mechanism remains unclear. A bone marrow transplantation (BMT) model was established using immunodeficient mice, either nude (experiment 1) or V(D)J recombination activation gene deficient mice (RAG-1(-/-)) (experiment 2) as recipients and M. fortis or C57BL/6 mice as donors. The growth and development of S. japonicum were evaluated in each group to assess the role of M. fortis lymphocytes in the response to infection. Lymphocyte ratios and S. japonicum-specific antibody production in transplanted groups increased significantly compared to those in non-transplanted group. Spleen indices and density of splenic lymphocytes in transplanted RAG-1(-/-) mice were higher than those in non-transplanted RAG-1(-/-) mice. No difference in the worm burden was observed among group A (transplants derived from M. fortis), B (transplants derived from C57BL/6 mouse) and C (non-transplanted mice), although worms in group A were shorter than those in other groups, except non-transplanted RAG-1(-/-) mice. Reproductive systems of worms in mice (nude or RAG-1(-/-)) transplanted from M. fortis were not as mature as those in mice (nude or RAG-1(-/-)) transplanted from C57BL/6 mouse and non-transplanted nude mice, but they were more mature than worms in non-transplanted RAG-1(-/-) mice. Therefore, the transplantation model using nude and RAG-1(-/-) mice was successfully established. The M. fortis lymphocytes did not appear to affect the S. japonicum worm burden, but they led to schistosome shortening and a significant reduction in parasite spawning. Thus, M. fortis cellular and humoral immunity provides a defense against schistosomes by negatively impacting the parasite growth and reproductive development. Copyright © 2014 Elsevier Inc. All rights reserved.

Spatial and temporal differences in giant kidney worm, dictophyma renale, prevalence in Minnesota Mink, Mustela vison

USGS Publications Warehouse

Mech, L.D.

2008-01-01

Examination of 110 Mink (Mustela vison) carcasses from 1998 through 2007 indicated that the giant kidney worm, Dioctophyma renale, occurred in Pine and Kanabec Counties of eastern Minnesota with annual prevalences of 0-92%. Worm prevalence increased from 20% in 1999 to 92% in 2001 and decreased to 6% in 2005. During 2000 to 2007, no worms were found in Mink from Anoka and Chisago Counties (n = 54), and in 2000, none in 107 Mink from LeSeur, Freeborn, Redwood, Brown and Watonwan Counties. Changes in kidney worm prevalence were positively related to trapping success, considered an index of Mink density.

Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks.

PubMed

Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

2017-01-13

WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator's mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost.

Metals and terrestrial earthworms (Annelida: Oligochaeta)

USGS Publications Warehouse

Beyer, W.N.

1981-01-01

The toxicity of metals to earthworms and the residues of metals found in earthworms are reviewed. Meta 1 concentrations are rarely high enough to be toxic to worms, but copper may reduce populations in orchards heavily treated with fungicides and in soil contaminated with pig wastes. The metals in some industrial sewage sludges may interfere with using sludge in vermiculture. Storage ratios (the concentration of a metal in worms divided by the concentration in soil) tend to be highest in infertile soil and lowest in media rich in organic matter, such as sewage sludge. Cadmium, gold, and selenium are highly concentrated by worms. Lead concentrations in worms may be very high, but are generally lower than concentrations in soil. Body burdens of both copper and zinc seem to be regulated by worms. Because worms are part of the food webs of many wildlife species, and also because they are potentially valuable feed supplements for domestic animals, the possible toxic effects of cadmium and other metals should be studied. Worms can make metals more available to food webs and can redistribute them in soil.

The Mitochondrial Genomes of the Zoonotic Canine Filarial Parasites Dirofilaria (Nochtiella) repens and Candidatus Dirofilaria (Nochtiella) Honkongensis Provide Evidence for Presence of Cryptic Species

PubMed Central

Yilmaz, Esra; Fritzenwanker, Moritz; Pantchev, Nikola; Lendner, Mathias; Wongkamchai, Sirichit; Otranto, Domenico; Kroidl, Inge; Dennebaum, Martin; Le, Thanh Hoa; Anh Le, Tran; Ramünke, Sabrina; Schaper, Roland; von Samson-Himmelstjerna, Georg; Poppert, Sven; Krücken, Jürgen

2016-01-01

Background Cutaneous dirofilariosis is a canine mosquito-borne zoonosis that can cause larva migrans disease in humans. Dirofilaria repens is considered an emerging pathogen occurring with high prevalence in Mediterranean areas and many parts of tropical Asia. In Hong Kong, a second species, Candidatus Dirofilaria hongkongensis, has been reported. The present study aimed to compare mitochondrial genomes from these parasites and to obtain population genetic information. Methods and Findings Complete mitochondrial genomes were obtained by PCR and Sanger sequencing or ILLUMINA sequencing for four worms. Cytochrome oxidase subunit 1 sequences identified three as D. repens (all from Europe) and one as C. D. hongkongensis (from India). Mitochondrial genomes have the same organization as in other spirurid nematodes but a higher preference for thymine in the coding strand. Phylogenetic analysis was in contradiction to current taxonomy of the Onchocercidae but in agreement with a recent multi-locus phylogenetic analysis using both mitochondrial and nuclear markers. D. repens and C. D. hongkongensis sequences clustered together and were the common sister group to Dirofilaria immitis. Analysis of a 2.5 kb mitochondrial genome fragment from macrofilaria or canine blood samples from Europe (42), Thailand (2), India (1) and Vietnam (1) revealed only small genetic differences in the D. repens samples including all European and the Vietnam sample. The Indian C. D. hongkongensis and the two Thai samples formed separate clusters and differences were comparatively large. Conclusion Genetic differences between Dirofilaria spp. causing cutaneous disease can be considerable whereas D. repens itself was genetically quite homogenous. C. D. hongkongensis was identified for the first time from the Indian subcontinent. The full mitochondrial genome sequence strengthens the hypothesis that it represents an independent species and the Thai samples might represent another cryptic species, Candidatus Dirofilaria sp. ‘Thailand II’, or a quite divergent population of C. D. hongkongensis. PMID:27727270

Considerations for using minocycline vs doxycycline for treatment of canine heartworm disease.

PubMed

Papich, Mark G

2017-11-09

Doxycycline has been considered the first drug of choice for treating Wolbachia, a member of the Rickettsiaceae, which has a symbiotic relationship with filarial worms, including heartworms. Wolbachia, is susceptible to tetracyclines, which have been used as adjunctive treatments for heartworm disease. Treatment with doxycycline reduces Wolbachia numbers in all stages of heartworms and improves outcomes and decreased microfilaremia in dogs treated for heartworm disease. The American Heartworm Society recommends treatment with doxycycline in dogs diagnosed with heartworm disease at a dose of 10 mg/kg twice daily for 28 days. If doxycycline is not available, minocycline can be considered as a substitute. However, minocycline has not undergone an evaluation in dogs with heartworm disease, nor has an effective dose been established. Minocycline is an attractive option because of the higher cost of doxycycline and new pharmacokinetic information for dogs that provides guidance for appropriate dosage regimens to achieve pharmacokinetic-pharmacodynamic (PK-PD) targets. Published reports from the Anti-Wolbachia Consortium (A-WOL) indicate superior in vitro activity of minocycline over doxycycline. Studies performed in mouse models to measure anti-Wolbachia activity showed that minocycline was 1.7 times more effective than doxycycline, despite a 3-fold lower pharmacokinetic exposure. To achieve the same exposure as achieved in the mouse infection model, a pharmacokinetic-pharmacodynamic (PK-PD) analysis was conducted to determine optimal dosages for dogs. The analysis showed that an oral minocycline dose of 3.75 to 5 mg/kg administered twice daily would attain similar targets as observed in mice and predicted for human infections. There are potentially several advantages for use of minocycline in animals. It is well absorbed from oral administration, it has less protein binding than doxycycline (65% vs 92%) allowing for better distribution into tissue, and it is approximately two times more lipophilic than doxycycline, which may result in better intracellular penetration. More work is needed to document efficacy of minocycline for treating canine heartworm disease.

Seroreactivity to Dirofilaria antigens in people from different areas of Serbia.

PubMed

Tasić-Otašević, Suzana A; Gabrielli, Simona V; Tasić, Aleksandar V; Miladinovićtasić, Nataša L; Kostić, Jovana T; Ignjatović, Aleksandra M; Popović Dragonjić, Lidija D; Milošević, Zoran G; Arsić-Arsenijević, Valentina S; Cancrini, Gabriella A

2014-02-08

The Northern part of Serbia is hyperendemic-endemic for canine dirofilarioses. Considering this fact, many human dirofilarial infections could be expected, however only about 30 cases in Serbia have been described until today. Aims of this survey were to assess the people reactivity to the antigens of D. repens and D. immitis and to identify risk factors for the contact exposure. Investigation included sera taken from 297 people (179 women and 118 men) living in different areas of Serbia (Pančevo, Novi Sad, Zaječar, Leskovac, Vranje, Niš, Pirot). Sera were analysed by means of two indirect enzyme-linked immunosorbent (ELISA) home-designed that use as antigens adult somatic/metabolic polyproteins of D. repens (DR) and D. immitis (DI), respectively. The results were elaborated using the statistical method of descriptive and quantitative analysis. Significant differences by area in the reactivity of human sera to dirofilarial antigens were not observed (p = 0.056). A high seroreactivity was demonstrated in people from the towns of northern Serbia (Pančevo = 27,1%; Novi Sad = 16,3%), as well as in people from Zaječar (eastern Serbia = 15,8%) and Vranje (southern Serbia = 15,1%). No differences were evidenced between people reactivity to polyproteins of the two dirofilarial species, nor differences related to the gender of examinees. Factor risks evidenced were: i) place of residence; ii) spending work time outdoors during the mosquito season; iii) spending time outdoors and nearby rivers, lakes, swamps or canals; unespectedly, iv) cat owning. The findings emerging from this investigation indicate that clinicians and public health authorities should pay greater attention to this zoonosis. Continuing education and training of physicians will greatly contribute to the knowledge of the actual impact of filarial worms on animal and public health, and allow for the planning of suitable measures to prevent the infections.

Seroreactivity to Dirofilaria antigens in people from different areas of Serbia

PubMed Central

2014-01-01

Background The Northern part of Serbia is hyperendemic-endemic for canine dirofilarioses. Considering this fact, many human dirofilarial infections could be expected, however only about 30 cases in Serbia have been described until today. Aims of this survey were to assess the people reactivity to the antigens of D. repens and D. immitis and to identify risk factors for the contact exposure. Methods Investigation included sera taken from 297 people (179 women and 118 men) living in different areas of Serbia (Pančevo, Novi Sad, Zaječar, Leskovac, Vranje, Niš, Pirot). Sera were analysed by means of two indirect enzyme-linked immunosorbent (ELISA) home-designed that use as antigens adult somatic/metabolic polyproteins of D. repens (DR) and D. immitis (DI), respectively. The results were elaborated using the statistical method of descriptive and quantitative analysis. Results Significant differences by area in the reactivity of human sera to dirofilarial antigens were not observed (p = 0.056). A high seroreactivity was demonstrated in people from the towns of northern Serbia (Pančevo = 27,1%; Novi Sad = 16,3%), as well as in people from Zaječar (eastern Serbia = 15,8%) and Vranje (southern Serbia = 15,1%). No differences were evidenced between people reactivity to polyproteins of the two dirofilarial species, nor differences related to the gender of examinees. Factor risks evidenced were: i) place of residence; ii) spending work time outdoors during the mosquito season; iii) spending time outdoors and nearby rivers, lakes, swamps or canals; unespectedly, iv) cat owning. Conclusion The findings emerging from this investigation indicate that clinicians and public health authorities should pay greater attention to this zoonosis. Continuing education and training of physicians will greatly contribute to the knowledge of the actual impact of filarial worms on animal and public health, and allow for the planning of suitable measures to prevent the infections. PMID:24507413

Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) Arenaceodentata: Non treatment Factors

DTIC Science & Technology

1992-09-01

example, grain size had no effect , while the number of worms added to each expo- sure vessel was critical. Direct transfer from 30 ppt to salinities !515... Effect of Salinity on Juvenile Worms ..................... 13 Effect of Ammonia on Juvenile Worms .................... 14 Resistance of Juvenile Worms to...experimental design used to evaluate salinity effects . Preliminary experiments indicated that nominal ammonia concentrations (0, 2.5, 5.0, 10, 20, and

Refined stratified-worm-burden models that incorporate specific biological features of human and snail hosts provide better estimates of Schistosoma diagnosis, transmission, and control.

PubMed

Gurarie, David; King, Charles H; Yoon, Nara; Li, Emily

2016-08-04

Schistosoma parasites sustain a complex transmission process that cycles between a definitive human host, two free-swimming larval stages, and an intermediate snail host. Multiple factors modify their transmission and affect their control, including heterogeneity in host populations and environment, the aggregated distribution of human worm burdens, and features of parasite reproduction and host snail biology. Because these factors serve to enhance local transmission, their inclusion is important in attempting accurate quantitative prediction of the outcomes of schistosomiasis control programs. However, their inclusion raises many mathematical and computational challenges. To address these, we have recently developed a tractable stratified worm burden (SWB) model that occupies an intermediate place between simpler deterministic mean worm burden models and the very computationally-intensive, autonomous agent models. To refine the accuracy of model predictions, we modified an earlier version of the SWB by incorporating factors representing essential in-host biology (parasite mating, aggregation, density-dependent fecundity, and random egg-release) into demographically structured host communities. We also revised the snail component of the transmission model to reflect a saturable form of human-to-snail transmission. The new model allowed us to realistically simulate overdispersed egg-test results observed in individual-level field data. We further developed a Bayesian-type calibration methodology that accounted for model and data uncertainties. The new model methodology was applied to multi-year, individual-level field data on S. haematobium infections in coastal Kenya. We successfully derived age-specific estimates of worm burden distributions and worm fecundity and crowding functions for children and adults. Estimates from the new SWB model were compared with those from the older, simpler SWB with some substantial differences noted. We validated our new SWB estimates in prediction of drug treatment-based control outcomes for a typical Kenyan community. The new version of the SWB model provides a better tool to predict the outcomes of ongoing schistosomiasis control programs. It reflects parasite features that augment and perpetuate transmission, while it also readily incorporates differences in diagnostic testing and human sub-population differences in treatment coverage. Once extended to other Schistosoma species and transmission environments, it will provide a useful and efficient tool for planning control and elimination strategies.

Knowledge, practices and perceptions of geo-helminthes infection among parents of pre-school age children of coastal region, Kenya.

PubMed

Masaku, Janet; Mwende, Faith; Odhiambo, Gladys; Musuva, Rosemary; Matey, Elizabeth; Kihara, Jimmy H; Thuita, Isaac G; Njomo, Doris W

2017-03-01

Soil-transmitted helminthes (STHs) are common human parasitic diseases in most of the developing world particularly in Kenya. The ongoing National School-Based Deworming Programme (NSBDP) was launched in 2012 and is currently targeting 28 of the 47 endemic Counties. In an effort to improve treatment intervention strategies among Pre-School Age Children (PSAC) attending Early Childhood Development Centres (ECDC), we sought to assess parents' knowledge, perceptions and practices on worm infection. We conducted a qualitative cross-sectional study in four endemic sub-counties of two counties of coastal region of Kenya. A total of 20 focus group discussions (FGDs) categorized by gender were conducted among parents of pre-school age children. Participants were purposively selected based on homogenous characteristics with the saturation model determining the number of focus group discussions conducted. The data collected was analyzed manually by study themes. The majority of the parents had knowledge on worms and modes of transmission of the parasitic infections among the pre-school children. Also, most of the participants knew the causes of worm infection and the pre- disposing factors mentioned included poor hygiene and sanitation practices. Due to poor knowledge of signs and symptoms, misconceptions about the drugs administered during the NSBDP were common with a large majority of the parents indicating that the drugs were ineffective in worm control. The findings also indicated that most of the participants sought medical care on the onset of the signs and symptoms of worm infestation and preferred services provided at public health facilities as opposed to private health facilities or buying drugs from the local market citing mistrust of such services. Cultural beliefs, high cost of building and availability of vast pieces of land for human waste disposal were factors that contributed to low or lack of latrine ownership and usage by a large majority of the respondents. Our results show that to a large extent the parents of the pre-school age children have information on worm infections. However, some cultural beliefs and practices on the pathology and mode of transmission mentioned could be a hindrance to prevention and control efforts. There is need to implement health promotion campaigns to strengthen the impact of control strategies and reduce infection.

Knowledge, practices and perceptions of geo-helminthes infection among parents of pre-school age children of coastal region, Kenya

PubMed Central

Mwende, Faith; Odhiambo, Gladys; Musuva, Rosemary; Matey, Elizabeth; Kihara, Jimmy H.; Thuita, Isaac G.; Njomo, Doris W.

2017-01-01

Background Soil-transmitted helminthes (STHs) are common human parasitic diseases in most of the developing world particularly in Kenya. The ongoing National School-Based Deworming Programme (NSBDP) was launched in 2012 and is currently targeting 28 of the 47 endemic Counties. In an effort to improve treatment intervention strategies among Pre-School Age Children (PSAC) attending Early Childhood Development Centres (ECDC), we sought to assess parents’ knowledge, perceptions and practices on worm infection. Methodology We conducted a qualitative cross-sectional study in four endemic sub-counties of two counties of coastal region of Kenya. A total of 20 focus group discussions (FGDs) categorized by gender were conducted among parents of pre-school age children. Participants were purposively selected based on homogenous characteristics with the saturation model determining the number of focus group discussions conducted. The data collected was analyzed manually by study themes. Findings The majority of the parents had knowledge on worms and modes of transmission of the parasitic infections among the pre-school children. Also, most of the participants knew the causes of worm infection and the pre- disposing factors mentioned included poor hygiene and sanitation practices. Due to poor knowledge of signs and symptoms, misconceptions about the drugs administered during the NSBDP were common with a large majority of the parents indicating that the drugs were ineffective in worm control. The findings also indicated that most of the participants sought medical care on the onset of the signs and symptoms of worm infestation and preferred services provided at public health facilities as opposed to private health facilities or buying drugs from the local market citing mistrust of such services. Cultural beliefs, high cost of building and availability of vast pieces of land for human waste disposal were factors that contributed to low or lack of latrine ownership and usage by a large majority of the respondents. Conclusions Our results show that to a large extent the parents of the pre-school age children have information on worm infections. However, some cultural beliefs and practices on the pathology and mode of transmission mentioned could be a hindrance to prevention and control efforts. There is need to implement health promotion campaigns to strengthen the impact of control strategies and reduce infection. PMID:28358802

Sago worms as a nutritious traditional and alternative food for rural children in Southeast Sulawesi, Indonesia.

PubMed

Nirmala, Intan R; Trees; Suwarni; Pramono, Mochammad S

2017-06-01

The sago worm Rhynchophorus ferrugineus is a nutritious food source found in the remaining parts of a sago palm trunk after the removal of sago starch by farmers. The effort to increase sago worm consumption is investigated in an intervention study among children aged <5 years. Children aged 1-5 years were allocated to a sago worm inclusive diet (n=10) and to a control group eating a usual diet, but without sago worms (n=13). Snacks were served once per day (100 g) for 45 days and designed to contain similar amounts of vegetables (carrots and long beans) and other ingredients including rice, sticky rice, cassava, sweet potato, banana, or tofu with or without sago worms. Food preference was ascertained by interview. Anthropometric measurements were taken at baseline and the endpoint. After mixing all food stuffs into one product for instance nasi gurih, protein and fat content in the intervention group was higher compared to control group (8.8 g and 7.3 g vs 4.7 g and 0.5 g respectively). In the intervention group receiving complementary feeding with sago worms, children's height changed minimally as did the control group (0.3 vs 0.2 cm); no difference was observed between the groups regarding weight or height. Sago worm consumption can diversify the diet through usage in various dishes, so improving its overall nutritional quality. Worm addition in an intervention program does not compromise, but maintains nutritional value. Local use adds affordability and sustainability to the food and health systems in a sago-consuming culture, so contributing to food security.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorfman, D.

Earthworms can live in soils containing high quantities of mercury, lead, and zinc. The worms (Lumbricus terrestris) concentrate these heavy metals in their tissues. The use of these worms to reduce the quantities of mercury and other heavy metals in soils may be practical. In July, 1993, a preliminary study was made using earthworms and soils with differing amounts of mercury, The quantities were 0.0 grams, 0.5 grams, and 1.0 grams of mercury as mercuric chloride. Earthworms were placed into these soils for two or more weeks, then harvested. The worms were rinsed with deionized water, then dissolved in nitricmore » acid. Each sample was prepared for analysis with the addition of HNO{sub 3}, H{sub 2}SO{sub 4}, potassium permanganate, and hydrozylamine hydrochloride. A Jerome Instrument gold foil analyzer was used to determine levels of mercury after volatilizing the sample with stannous chloride. Worms exposed to contaminated soils remove 50 to 1,400 times as much mercury as do worms in control soils. In a hypothetical case, a site contaminated with one pound of mercury, 1,000 to 45,000 worms would be required to reduce mercury levels to background levels in the soil (about 250 ppb). After harvesting worms in contaminated soil they could be dried (90% of their weight is water), and the mercury regained by chemical processes. Soil conducive to earthworm survival is required. This includes a well aerated loamy soil, proper pH (7.0), and periodic watering and feeding. There are several methods of harvesting worms, including flooding and electricity. Large numbers of worms can be obtained from commercial growers.« less

Reversible and long-term immobilization in a hydrogel-microbead matrix for high-resolution imaging of Caenorhabditis elegans and other small organisms

PubMed Central

Cornaglia, Matteo; Krishnamani, Gopalan; Zhang, Jingwei; Mouchiroud, Laurent; Lehnert, Thomas; Auwerx, Johan; Gijs, Martin A. M.

2018-01-01

The nematode Caenorhabditis elegans is an important model organism for biomedical research and genetic studies relevant to human biology and disease. Such studies are often based on high-resolution imaging of dynamic biological processes in the worm body tissues, requiring well-immobilized and physiologically active animals in order to avoid movement-related artifacts and to obtain meaningful biological information. However, existing immobilization methods employ the application of either anesthetics or servere physical constraints, by using glue or specific microfluidic on-chip mechanical structures, which in some cases may strongly affect physiological processes of the animals. Here, we immobilize C. elegans nematodes by taking advantage of a biocompatible and temperature-responsive hydrogel-microbead matrix. Our gel-based immobilization technique does not require a specific chip design and enables fast and reversible immobilization, thereby allowing successive imaging of the same single worm or of small worm populations at all development stages for several days. We successfully demonstrated the applicability of this method in challenging worm imaging contexts, in particular by applying it for high-resolution confocal imaging of the mitochondrial morphology in worm body wall muscle cells and for the long-term quantification of number and size of specific protein aggregates in different C. elegans neurodegenerative disease models. Our approach was also suitable for immobilizing other small organisms, such as the larvae of the fruit fly Drosophila melanogaster and the unicellular parasite Trypanosoma brucei. We anticipate that this versatile technique will significantly simplify biological assay-based longitudinal studies and long-term observation of small model organisms. PMID:29509812

Burrowing by small polychaetes - mechanics, behavior and muscle structure of Capitella sp.

PubMed

Grill, Susann; Dorgan, Kelly M

2015-05-15

Worms of different sizes extend burrows through muddy sediments by fracture, applying dorso-ventral forces that are amplified at the crack tip. Smaller worms displace sediments less than larger worms and therefore are limited in how much force they can apply to burrow walls. We hypothesized that small worms would exhibit a transition in burrowing mechanics, specifically a lower limit in body size for the ability to burrow by fracture, corresponding with an ontogenetic transition in muscle morphology. Kinematics of burrowing in a mud analog, external morphology and muscle arrangement were examined in juveniles and adults of the small polychaete Capitella sp. We found that it moves by peristalsis, and no obvious differences were observed among worms of different sizes; even very small juveniles were able to burrow through a clear mud analog by fracture. Interestingly, we found that in addition to longitudinal and circular muscles needed for peristaltic movements, left- and right-handed helical muscles wrap around the thorax of worms of all sizes. We suggest that in small worms helical muscles may function to supplement forces generated by longitudinal muscles and to maintain hydrostatic pressure, enabling higher forces to be exerted on the crack wall. Further research is needed, however, to determine whether surficial sediments inhabited by small worms fail by fracture or plastically deform under forces of the magnitudes applied by Capitella sp. © 2015. Published by The Company of Biologists Ltd.

The provision of potable water in eradication of Guinea worm infection in Ezza North, Southeastern, Nigeria.

PubMed

Ede, Alison Okorie; Nwaokoro, Joakin Chidozie; Iwuala, C C; Amadi, A N; Akpelu, Ugochinyere Alvana

2014-10-01

Guinea worm is a parasite found in unprotected drinking water sources, causes considerable morbidity and loss of agricultural production among rural people. The study was to determine the current status of Guinea worm infection in Ezza North and to evaluate the impact of control measures on guinea worm infection. A total of 200 individuals in Ezza North Southeastern, Nigeria were examined for guinea worm infection. A standardized questionnaire was used to determine the effect of potable water on guinea worm eradication/control, the source of drinking water, information on the knowledge, attitude, symptom management practices, availability of health facilities and boreholes installation status. The instrument for data collection was well constructed, validated and reliable tested questionnaire by an expert. Data obtained was analyzed using Epi-Info model 3.4 versions. Results of a study indicated majority of the respondents 195 (97.5 %) have access to safe drinking water supply which indicated no case of Guinea worm infection. The active use of potable water supply was found among the age group of 20-30 years 71 (35.5 %) and higher in male (57.5 %) than females (42.5 %). The drastic reduction of Guinea worm infection to zero (0) level in Ezza North were due to multiple factors as health education, availability of functional boreholes, presence of health centers for immediate treatment if any case discovered.

Promoting positive health behaviours--'tooth worm' phenomenon and its implications.

PubMed

Gao, X L; Hsu, C Y S; Xu, Y C; Loh, T; Koh, D; Hwarng, H B

2012-03-01

'Tooth worm' is a traditional belief about the pathogen of dental caries (tooth decay). Nevertheless, in our previous study, parental 'tooth worm' belief was linked to a reduced caries risk of their children. This study aimed to further characterize the impact of parental 'tooth worm' belief on their children's caries experience and its psychobehavioural mechanisms. analytic observational study. Thirteen randomly selected kindergartens in Singapore. 1,782 preschoolers aged 3-6 years. Each child received an oral examination and microbiological tests. Parents completed a self-administered questionnaire on their socio-demographic background, oral health knowledge/attitude and child's oral health habits. Multivariate analysis confirmed a reduced chance of 'high caries rate' (number of affected teeth > 2) among children whose parents held the 'tooth worm' belief (Odds Ratio = 0.41; 95% Confidence Interval = 0.19-0.89). With such perception among parents, children brushed their teeth more frequently (p = 0.042). Since no difference in oral hygiene was observed, the health benefit of the "tooth worm" perception may be acquired through the delivery of fluoride (an agent with proven anti-caries effect) during frequent toothbrushing episodes. This study revealed a 'tooth worm' phenomenon, indicating that parental 'tooth worm' belief is associated with early establishment of regular toothbrushing habit and reduction of dental caries in children. This phenomenon and its psychobehavioural mechanisms, enriching our understanding of oral health behaviours, have implications for effective health education.

The impact of various distance between axes of worm gear on torque value. Worm gear test stand

NASA Astrophysics Data System (ADS)

Sobek, M.; Baier, A.; Grabowski, Ł.

2017-08-01

Transferring both rotational and translational movements in systems used in the automotive industry is a very important and complex issue. In addition, the situation becomes much more difficult and complicated when the design of the transition system requires a high precision of operation as well as a well definite and long operating life. Such requirements are imposed on all components of today’s motor vehicles. However, particular attention is paid to the elements that directly or indirectly affect the safety of persons traveling in the vehicle. Such components are undoubtedly components included as parts of the steering system of the vehicle. Power steering systems have been present in motor vehicles for more than a century. They go through continuous metamorphosis and they are getting better and better. Current power steering systems are based on an electric motor and some kind of transmission. Depending on the position of the drive relative to the steering column, different configurations of the transmission are used. This article will cover issues related to tests of power steering gearing using a worm drive. The worm drive is a very specific example of a propulsion system that uses twisted axles. Normally, in this type of transition you can find two gear units with the axis mounted with a 90° angle between. The components of the worm drive are a worm and a worm gear, also called a worm wheel. In terms of the geometrical form, the worm resembles a helical spur gear. The shape of the worm is similar to the shape of a screw with a trapezoidal thread. A correct matching of these two components ensures proper operation of the entire transmission. Incorrect positioning of the components in relation to each other can significantly reduce the lifetime of the drive unit, and also lead to abnormal work, eg by raising the noise level. This article describes a test method of finding the appropriate distance between the axles of both worm drive units by testing the torque change during gear operation.

WormBase ParaSite - a comprehensive resource for helminth genomics.

PubMed

Howe, Kevin L; Bolt, Bruce J; Shafie, Myriam; Kersey, Paul; Berriman, Matthew

2017-07-01

The number of publicly available parasitic worm genome sequences has increased dramatically in the past three years, and research interest in helminth functional genomics is now quickly gathering pace in response to the foundation that has been laid by these collective efforts. A systematic approach to the organisation, curation, analysis and presentation of these data is clearly vital for maximising the utility of these data to researchers. We have developed a portal called WormBase ParaSite (http://parasite.wormbase.org) for interrogating helminth genomes on a large scale. Data from over 100 nematode and platyhelminth species are integrated, adding value by way of systematic and consistent functional annotation (e.g. protein domains and Gene Ontology terms), gene expression analysis (e.g. alignment of life-stage specific transcriptome data sets), and comparative analysis (e.g. orthologues and paralogues). We provide several ways of exploring the data, including genome browsers, genome and gene summary pages, text search, sequence search, a query wizard, bulk downloads, and programmatic interfaces. In this review, we provide an overview of the back-end infrastructure and analysis behind WormBase ParaSite, and the displays and tools available to users for interrogating helminth genomic data. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

New haystacks reveal new needles: using Caenorhabditis elegans to identify novel targets for ameliorating body composition changes during human aging.

PubMed

Wolkow, Catherine A

2010-01-01

Dramatic changes in body composition accompany aging in humans, particularly with respect to adiposity and the musculature. People accumulate fat as they age and lose muscle mass and strength. Caenorhabditis elegans nematodes are small, hermaphroditic soil nematodes that offer a flexible model for studying genetic pathways regulating body composition in humans. While there are significant physiological differences between worms and people, many of the genetic pathways relevant to human lipid and muscle homeostasis are present in worms. Initial studies indicate that adiposity increases in C. elegans during aging, as occurs in humans. Furthermore, substantial evidence demonstrates age-related loss of muscle mass in worms. Possible mechanisms for these changes in C. elegans are presented. Recent studies have highlighted neuroendocrine and environmental signals regulating C. elegans fat metabolism. Potential dysfunction of these pathways during aging could affect overall fat accumulation. By contrast, muscle decline in aging worms results from accumulated damage and 'wear-and-tear' over life span. However, neuroendocrine pathways also regulate muscle mass in response to food availability. Such pathways might provide useful therapeutic approaches for combating muscle loss during aging. From this chapter, readers will develop a deeper understanding of the ways that C.elegans can be used for mechanistic gerontological studies. Copyright © 2010 S. Karger AG, Basel.

Maternal hookworm modifies risk factors for childhood eczema: results from a birth cohort in Uganda

PubMed Central

Mpairwe, Harriet; Ndibazza, Juliet; Webb, Emily L; Nampijja, Margaret; Muhangi, Lawrence; Apule, Barbara; Lule, Swaib; Akurut, Hellen; Kizito, Dennison; Kakande, Mohammed; Jones, Frances M; Fitzsimmons, Colin M; Muwanga, Moses; Rodrigues, Laura C; Dunne, David W; Elliott, Alison M

2014-01-01

Background Worms may protect against allergy. Early-life worm exposure may be critical, but this has not been fully investigated. Objectives To investigate whether worms in pregnancy and in early childhood are associated with childhood eczema incidence. Methods The Entebbe Mother and Baby Study, an anthelminthic treatment trial, enrolled pregnant women between 2003 and 2005 in Uganda. Mothers were investigated for worms during pregnancy and children annually. Eczema was doctor-diagnosed from birth to age five years. A planned observational analysis was conducted within the trial cohort to investigate associations between worms and eczema. Results Data for 2345 live-born children were analysed. Hookworm was the most prevalent maternal worm (45%). Childhood worms were less prevalent. Eczema incidence was 4.68/100 person-years. Maternal hookworm was associated with reduced eczema incidence [adjusted hazard ratio (95% confidence interval), p-value: 0.71(0.51–0.99), 0.04] and modified effects of known risk factors for eczema: Dermatophagoides-specific IgE in children was positively associated with eczema incidence if the mother had no hookworm [2.72(1.11–6.63), 0.03], but not if the mother had hookworm [0.41(0.10–1.69), 0.22], interaction p-value = 0.03. Similar interactions were seen for maternal history of eczema {[2.87(1.31–6.27, 0.008) vs. [0.73(0.23–2.30), 0.60], interaction p-value = 0.05}, female gender {[1.82(1.22–2.73), 0.004 vs. [0.96(0.60–1.53), 0.87], interaction p-value = 0.04} and allergen-specific IgE. ChildhoodTrichuris trichiura and hookworm were inversely associated with eczema. Conclusions Maternal hookworm modifies effects of known risk factors for eczema. Mechanisms by which early-life worm exposures influence allergy need investigation. Worms or worm products, and intervention during pregnancy have potential for primary prevention of allergy. PMID:25171741

Tegumental alterations of adult Schistosoma japonicum harbored in mice treated with a single oral dose of mefloquine.

PubMed

Xiao, Shu-hua; Xue, Jian; Shen, Bing-gui

2010-02-01

To observe the effect of mefloquine on the tegument of adult Schistosoma japonicum harbored in mice. Twelve mice were each infected with 60-80 S. japonicum cercariae. At 35 days post-infection, 10 mice were treated orally with mefloquine at a single dose of 400 mg/kg. Two mice were sacrificed at 8 h, 24 h, 3 days, 7 days, and 14 days post-treatment respectively, and schistosomes were collected by the perfusion technique, fixed and examined under a scanning electron microscope. Schistosomes obtained from the remaining 2 untreated mice served as control. 8 h post-treatment, male and female schistosomes showed focal swelling of the worm body accompanied by extensive swelling, tough junction and fusion of tegumental ridges. Meanwhile, some of the sensory structures showed enlargement and part of them collapsed. 24 h after mefloquine administration, head portion of some male and female worms revealed high swelling accompanied by severe damage to oral sucker. 3 days post-treatment, focal swelling of worm body along the whole worm was universal. In some male and female worms, the damaged tegument fused together to form a large mass protruding from the tegumental surface. In addition, focal or extensive peeling of tegumental ridges was seen or collapse of enlarged sensory structure resulted in formation of hole-like appearance. 7 days post administration, focal swelling of worm body and damage to tegument induced by mefloquine were similar to those aforementioned, but focal peeling, collapse of enlarged sensory structures, and deformation of oral sucker in male and female worms were universal. 14 days post-treatment, individual male worm survived the treatment revealed normal appearance of tegumental ridges in head portion, although light focal swelling of worm body was still observed. Mefloquine causes focal swelling of worm body, extensive and severe damage to the tegument in adult S. japonicum.

Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua).

PubMed

Zuo, S; Barlaup, L; Mohammadkarami, A; Al-Jubury, A; Chen, D; Kania, P W; Buchmann, K

2017-10-01

Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast escape of more than 60% of the worm larvae within 20 min and gave full release within 65 min but the liver tissue became highly dispersed. HCl alone, in concentrations of 48 and 72 mM, triggered a corresponding release of worm larvae with minor effect on liver integrity. A lower HCl concentration of 24 mM resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation, with subsequent release of reaction products, may contribute to activation of C. osculatum larvae and induce escape reactions. Short-term pretreatment of infected cod liver and possibly other infected fish products, using low acid concentrations is suggested as part of a technological solution for worm clearance as low acid concentrations had limited macroscopic effect on liver integrity within 35 min.

Increased human IgE induced by killing Schistosoma mansoni in vivo is associated with pretreatment Th2 cytokine responsiveness to worm antigens.

PubMed

Walter, Klaudia; Fulford, Anthony J C; McBeath, Rowena; Joseph, Sarah; Jones, Frances M; Kariuki, H Curtis; Mwatha, Joseph K; Kimani, Gachuhi; Kabatereine, Narcis B; Vennervald, Birgitte J; Ouma, John H; Dunne, David W

2006-10-15

In schistosomiasis endemic areas, children are very susceptible to postchemotherapy reinfection, whereas adults are relatively resistant. Different studies have reported that schistosome-specific IL-4 and IL-5 responses, or posttreatment worm-IgE levels, correlate with subsequent low reinfection. Chemotherapy kills i.v. worms providing an in vivo Ag challenge. We measured anti-worm (soluble worm Ag (SWA) and recombinant tegumental Ag (rSm22.6)) and anti-egg (soluble egg Ag) Ab levels in 177 Ugandans (aged 7-50) in a high Schistosoma mansoni transmission area, both before and 7 wk posttreatment, and analyzed these data in relation to whole blood in vitro cytokine responses at the same time points. Soluble egg Ag-Ig levels were unaffected by treatment but worm-IgG1 and -IgG4 increased, whereas worm-IgE increased in many but not all individuals. An increase in worm-IgE was mainly seen in >15-year-olds and, unlike in children, was inversely correlated to pretreatment infection intensities, suggesting this response was associated both with resistance to pretreatment infection, as well as posttreatment reinfection. The increases in SWA-IgE and rSm22.6-IgE positively correlated with pretreatment Th2 cytokines, but not IFN-gamma, induced by SWA. These relationships remained significant after allowing for the confounding effects of pretreatment infection intensity, age, and pretreatment IgE levels, indicating a link between SWA-specific Th2 cytokine responsiveness and subsequent increases in worm-IgE. An exceptionally strong relationship between IL-5 and posttreatment worm-IgE levels in < 15-year-olds suggested that the failure of younger children to respond to in vivo Ag stimulation with increased levels of IgE, is related to their lack of pretreatment SWA Th2 cytokine responsiveness.

Worm melt fracture and fast die build-up at high shear rates in extrusion blow molding of large drums

NASA Astrophysics Data System (ADS)

Inn, Yong Woo; Sukhadia, Ashish M.

2017-05-01

In the extrusion blow molding process of high density polyethylene (HDPE) for making of large size drums, string-like defects, which are referred to as worm melt fracture in the industry, are often observed on the extrudate surface. Such string-like defects in various shapes and sizes are observed in capillary extrusion at very high shear rates after the slip-stick transition. The HDPE resin with broader molecular weight distribution (MWD) exhibits a greater degree of worm melt fracture while the narrow MWD PE resin, which has higher slip velocity and a uniform slip layer, shows a lesser degree of worm melt fracture. It is hypothesized that the worm melt fracture is related to fast die build-up and cohesive slip layer, a failure within the polymer melts at an internal surface. If the cohesive slip layer at an internal surface emerges out from the die, it can be attached on the surface of extrudate as string-like defects, the worm melt fracture. The resin having more small chains and lower plateau modulus can be easier to have such an internal failure and consequently exhibit more "worm" defects.

Propagation Modeling and Defending of a Mobile Sensor Worm in Wireless Sensor and Actuator Networks

PubMed Central

Wang, Tian; Wu, Qun; Wen, Sheng; Cai, Yiqiao; Tian, Hui; Chen, Yonghong; Wang, Baowei

2017-01-01

WSANs (Wireless Sensor and Actuator Networks) are derived from traditional wireless sensor networks by introducing mobile actuator elements. Previous studies indicated that mobile actuators can improve network performance in terms of data collection, energy supplementation, etc. However, according to our experimental simulations, the actuator’s mobility also causes the sensor worm to spread faster if an attacker launches worm attacks on an actuator and compromises it successfully. Traditional worm propagation models and defense strategies did not consider the diffusion with a mobile worm carrier. To address this new problem, we first propose a microscopic mathematical model to describe the propagation dynamics of the sensor worm. Then, a two-step local defending strategy (LDS) with a mobile patcher (a mobile element which can distribute patches) is designed to recover the network. In LDS, all recovering operations are only taken in a restricted region to minimize the cost. Extensive experimental results demonstrate that our model estimations are rather accurate and consistent with the actual spreading scenario of the mobile sensor worm. Moreover, on average, the LDS outperforms other algorithms by approximately 50% in terms of the cost. PMID:28098748

Toxic effects and bioaccumulation of the herbicide isoproturon in Tubifex tubifex (Oligocheate, Tubificidae): a study of significance of autotomy and its utility as a biomarker.

PubMed

Paris-Palacios, Séverine; Mosleh, Yahia Y; Almohamad, Mohamad; Delahaut, Laurence; Conrad, Arnaud; Arnoult, Fabrice; Biagianti-Risbourg, Sylvie

2010-06-01

Tubifex is the only animal reported to respond with autotomy to contamination. This response of contaminated worm is understood as a mode of metal excretion. Few data concern the potential of organic compounds to induce tubifex autotomy. The objective of this study was to investigate if autotomy can be induced by a herbicide isoproturon (IP) and be related to the way of excretion. Isoproturon accumulation in worm tissues and its effect on tubifex mortality, autotomy and regeneration rates were analysed after 4 and 7 days of exposure to the herbicide and also when worms were replaced for 10 days in clean water. IP accumulated in the same way in all parts of the worm body but IP metabolite rates were significantly higher in the posterior part of the worm. Thus the loss of the posterior part allows the worm to eliminate an important amount of pesticide. Autotomy has a population importance and is related to the degree of worm contamination so it may become an interesting biomarker. Copyright (c) 2010 Elsevier B.V. All rights reserved.

The Parallel Worm Tracker: A Platform for Measuring Average Speed and Drug-Induced Paralysis in Nematodes

PubMed Central

Ramot, Daniel; Johnson, Brandon E.; Berry, Tommie L.; Carnell, Lucinda; Goodman, Miriam B.

2008-01-01

Background Caenorhabditis elegans locomotion is a simple behavior that has been widely used to dissect genetic components of behavior, synaptic transmission, and muscle function. Many of the paradigms that have been created to study C. elegans locomotion rely on qualitative experimenter observation. Here we report the implementation of an automated tracking system developed to quantify the locomotion of multiple individual worms in parallel. Methodology/Principal Findings Our tracking system generates a consistent measurement of locomotion that allows direct comparison of results across experiments and experimenters and provides a standard method to share data between laboratories. The tracker utilizes a video camera attached to a zoom lens and a software package implemented in MATLAB®. We demonstrate several proof-of-principle applications for the tracker including measuring speed in the absence and presence of food and in the presence of serotonin. We further use the tracker to automatically quantify the time course of paralysis of worms exposed to aldicarb and levamisole and show that tracker performance compares favorably to data generated using a hand-scored metric. Conclusions/Signficance Although this is not the first automated tracking system developed to measure C. elegans locomotion, our tracking software package is freely available and provides a simple interface that includes tools for rapid data collection and analysis. By contrast with other tools, it is not dependent on a specific set of hardware. We propose that the tracker may be used for a broad range of additional worm locomotion applications including genetic and chemical screening. PMID:18493300

Lifted worm algorithm for the Ising model

NASA Astrophysics Data System (ADS)

Elçi, Eren Metin; Grimm, Jens; Ding, Lijie; Nasrawi, Abrahim; Garoni, Timothy M.; Deng, Youjin

2018-04-01

We design an irreversible worm algorithm for the zero-field ferromagnetic Ising model by using the lifting technique. We study the dynamic critical behavior of an energylike observable on both the complete graph and toroidal grids, and compare our findings with reversible algorithms such as the Prokof'ev-Svistunov worm algorithm. Our results show that the lifted worm algorithm improves the dynamic exponent of the energylike observable on the complete graph and leads to a significant constant improvement on toroidal grids.

Uncoupling of oxidative stress resistance and lifespan in long-lived isp-1 mitochondrial mutants in Caenorhabditis elegans.

PubMed

Dues, Dylan J; Schaar, Claire E; Johnson, Benjamin K; Bowman, Megan J; Winn, Mary E; Senchuk, Megan M; Van Raamsdonk, Jeremy M

2017-07-01

Mutations affecting components of the mitochondrial electron transport chain have been shown to increase lifespan in multiple species including the worm Caenorhabditis elegans. While it was originally proposed that decreased generation of reactive oxygen species (ROS) resulting from lower rates of electron transport could account for the observed increase in lifespan, recent evidence indicates that ROS levels are increased in at least some of these long-lived mitochondrial mutants. Here, we show that the long-lived mitochondrial mutant isp-1 worms have increased resistance to oxidative stress. Our results suggest that elevated ROS levels in isp-1 worms cause the activation of multiple stress-response pathways including the mitochondrial unfolded protein response, the SKN-1-mediated stress response, and the hypoxia response. In addition, these worms have increased expression of specific antioxidant enzymes, including a marked upregulation of the inducible superoxide dismutase genes sod-3 and sod-5. Examining the contribution of sod-3 and sod-5 to the oxidative stress resistance in isp-1 worms revealed that loss of either of these genes increased resistance to oxidative stress, but not other forms of stress. Deletion of sod-3 or sod-5 decreased the lifespan of isp-1 worms and further exacerbated their slow physiologic rates. Thus, while deletion of sod-3 and sod-5 genes has little impact on stress resistance, physiologic rates or lifespan in wild-type worms, these genes are required for the longevity of isp-1 worms. Overall, this work shows that the increased resistance to oxidative stress in isp-1 worms does not account for their longevity, and that resistance to oxidative stress can be experimentally dissociated from lifespan. Copyright © 2017 Elsevier Inc. All rights reserved.

A microfluidic array for high-content screening at whole-organism resolution

NASA Astrophysics Data System (ADS)

Migliozzi, D.; Cornaglia, M.; Mouchiroud, L.; Auwerx, J.; Gijs, M. A. M.

2018-02-01

A main step for the development and the validation of medical drugs is the screening on whole organisms, which gives the systemic information that is missing when using cellular models. Among the organisms of choice, Caenorhabditis elegansis a soil worm which catches the interest of researchers who study systemic physiopathology (e.g. metabolic and neurodegenerative diseases) because: (1) its large genetic homology with humans supports translational analysis; (2) worms are much easier to handle and grow in large amounts compared to rodents, for which (3) the costs and (4) the ethical concerns are substantial.C. elegansis therefore well suited for large screens, dose-response analysis and target-discovery involving an entire organism. We have developed and tested a microfluidic array for high-content screening, enabling the selection of small populations of its first larval stage in many separated chambers divided into channels for multiplexed screens. With automated protocols for feeding, drug administration and image acquisition, our chip enables the study of the nematodes throughout their entire lifespan. By using a paralyzing agent and a mitochondrial-stress inducer as case studies, we have demonstrated large field-of-view motility analysis, and worm-segmentation/signal-detection for mode-of-action quantification with genetically-encoded fluorescence reporters.

Dew Worms in the White Nights

USDA-ARS?s Scientific Manuscript database

Lumbricus terrestris L. (the dew worm) forages, mates and migrates on the soil surface during the night. Its distribution covers a broad latitudinal gradient and variation in day length conditions. Since soil-surface activity is crucial for the survival and reproduction of dew worms, it is conceivab...

Effect of time on migration of Oesophagostomum spp. and Hyostrongylus rubidus out of agar-gel.

PubMed

Nosal, P; Christensen, C M; Nansen, P

1998-01-01

The agar-gel migration technique has previously been described, however, aspects regarding the effect of timing on worm migration needed further scrutiny. In the first experiment, pigs inoculated with Oesophagostomum dentatum were slaughtered simultaneously and their intestines stored at 21-23 degrees C until processed pairwise 2, 4, 6, 8, 12 and 18 h after slaughter. More than 95% of the worms migrated out of the agar if processed within 6 h. In the second experiment, intestines were treated immediately after slaughter and the migratory speed of adult worms or 4th-stage larvae of O. dentatum or O. quadrispinulatum, or adult Hyostrongylus rubidus were studied. For both Oesophagostomum species, more than 90% of the worms were recovered within 1 h. H. rubidus was significantly slower; however, approximately 98% of the worms had migrated out of the agar-gel by 20 h. This information is essential in planning experiments where recovery of live worms is of value.

Hairworm anti-predator strategy: a study of causes and consequences.

PubMed

Ponton, F; Lebarbenchon, C; Lefèvre, T; Thomas, F; Duneau, D; Marché, L; Renault, L; Hughes, D P; Biron, D G

2006-11-01

One of the most fascinating anti-predator responses displayed by parasites is that of hairworms (Nematomorpha). Following the ingestion of the insect host by fish or frogs, the parasitic worm is able to actively exit both its host and the gut of the predator. Using as a model the hairworm, Paragordius tricuspidatus, (parasitizing the cricket Nemobius sylvestris) and the fish predator Micropterus salmoïdes, we explored, with proteomics tools, the physiological basis of this anti-predator response. By examining the proteome of the parasitic worm, we detected a differential expression of 27 protein spots in those worms able to escape the predator. Peptide Mass Fingerprints of candidate protein spots suggest the existence of an intense muscular activity in escaping worms, which functions in parallel with their distinctive biology. In a second step, we attempted to determine whether the energy expended by worms to escape the predator is traded off against its reproductive potential. Remarkably, the number of offspring produced by worms having escaped a predator was not reduced compared with controls.

WormQTL—public archive and analysis web portal for natural variation data in Caenorhabditis spp

PubMed Central

Snoek, L. Basten; Van der Velde, K. Joeri; Arends, Danny; Li, Yang; Beyer, Antje; Elvin, Mark; Fisher, Jasmin; Hajnal, Alex; Hengartner, Michael O.; Poulin, Gino B.; Rodriguez, Miriam; Schmid, Tobias; Schrimpf, Sabine; Xue, Feng; Jansen, Ritsert C.; Kammenga, Jan E.; Swertz, Morris A.

2013-01-01

Here, we present WormQTL (http://www.wormqtl.org), an easily accessible database enabling search, comparative analysis and meta-analysis of all data on variation in Caenorhabditis spp. Over the past decade, Caenorhabditis elegans has become instrumental for molecular quantitative genetics and the systems biology of natural variation. These efforts have resulted in a valuable amount of phenotypic, high-throughput molecular and genotypic data across different developmental worm stages and environments in hundreds of C. elegans strains. WormQTL provides a workbench of analysis tools for genotype–phenotype linkage and association mapping based on but not limited to R/qtl (http://www.rqtl.org). All data can be uploaded and downloaded using simple delimited text or Excel formats and are accessible via a public web user interface for biologists and R statistic and web service interfaces for bioinformaticians, based on open source MOLGENIS and xQTL workbench software. WormQTL welcomes data submissions from other worm researchers. PMID:23180786

WormQTL--public archive and analysis web portal for natural variation data in Caenorhabditis spp.

PubMed

Snoek, L Basten; Van der Velde, K Joeri; Arends, Danny; Li, Yang; Beyer, Antje; Elvin, Mark; Fisher, Jasmin; Hajnal, Alex; Hengartner, Michael O; Poulin, Gino B; Rodriguez, Miriam; Schmid, Tobias; Schrimpf, Sabine; Xue, Feng; Jansen, Ritsert C; Kammenga, Jan E; Swertz, Morris A

2013-01-01

Here, we present WormQTL (http://www.wormqtl.org), an easily accessible database enabling search, comparative analysis and meta-analysis of all data on variation in Caenorhabditis spp. Over the past decade, Caenorhabditis elegans has become instrumental for molecular quantitative genetics and the systems biology of natural variation. These efforts have resulted in a valuable amount of phenotypic, high-throughput molecular and genotypic data across different developmental worm stages and environments in hundreds of C. elegans strains. WormQTL provides a workbench of analysis tools for genotype-phenotype linkage and association mapping based on but not limited to R/qtl (http://www.rqtl.org). All data can be uploaded and downloaded using simple delimited text or Excel formats and are accessible via a public web user interface for biologists and R statistic and web service interfaces for bioinformaticians, based on open source MOLGENIS and xQTL workbench software. WormQTL welcomes data submissions from other worm researchers.

Stage-specific Proteomes from Onchocerca ochengi, Sister Species of the Human River Blindness Parasite, Uncover Adaptations to a Nodular Lifestyle.

PubMed

Armstrong, Stuart D; Xia, Dong; Bah, Germanus S; Krishna, Ritesh; Ngangyung, Henrietta F; LaCourse, E James; McSorley, Henry J; Kengne-Ouafo, Jonas A; Chounna-Ndongmo, Patrick W; Wanji, Samuel; Enyong, Peter A; Taylor, David W; Blaxter, Mark L; Wastling, Jonathan M; Tanya, Vincent N; Makepeace, Benjamin L

2016-08-01

Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Stage-specific Proteomes from Onchocerca ochengi, Sister Species of the Human River Blindness Parasite, Uncover Adaptations to a Nodular Lifestyle*

PubMed Central

Armstrong, Stuart D.; Xia, Dong; Bah, Germanus S.; Krishna, Ritesh; Ngangyung, Henrietta F.; LaCourse, E. James; McSorley, Henry J.; Kengne-Ouafo, Jonas A.; Chounna-Ndongmo, Patrick W.; Wanji, Samuel; Enyong, Peter A.; Taylor, David W.; Blaxter, Mark L.; Wastling, Jonathan M.; Tanya, Vincent N.; Makepeace, Benjamin L.

2016-01-01

Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus. The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers. PMID:27226403

Large Format Multifunction 2-Terabyte Optical Disk Storage System

NASA Technical Reports Server (NTRS)

Kaiser, David R.; Brucker, Charles F.; Gage, Edward C.; Hatwar, T. K.; Simmons, George O.

1996-01-01

The Kodak Digital Science OD System 2000E automated disk library (ADL) base module and write-once drive are being developed as the next generation commercial product to the currently available System 2000 ADL. Under government sponsorship with the Air Force's Rome Laboratory, Kodak is developing magneto-optic (M-O) subsystems compatible with the Kodak Digital Science ODW25 drive architecture, which will result in a multifunction (MF) drive capable of reading and writing 25 gigabyte (GB) WORM media and 15 GB erasable media. In an OD system 2000 E ADL configuration with 4 MF drives and 100 total disks with a 50% ration of WORM and M-O media, 2.0 terabytes (TB) of versatile near line mass storage is available.

A case of elephantiasis nostras verrucosa treated by acitretin.

PubMed

Polat, Mualla; Sereflican, Betül

2012-03-01

Elephantiasis nostras verrucosa is a rare disorder characterized by dermal fibrosis, hyperkeratotic, verrucous, and papillomatous lesions that result from both chronic filarial and nonfilarial lymphedema. Various treatment options have been reported for this disease. We present a 64-year-old man with erythrodermic psoriasis and elephantiasis nostras verrucosa in whom the lesions were resolved almost completely after acitretin treatment.

T-kininogen, a cystatin-like molecule, inhibits ERK-dependent lymphocyte proliferation.

PubMed

Acuña-Castillo, Claudio; Aravena, Mauricio; Leiva-Salcedo, Elías; Pérez, Viviana; Gómez, Christian; Sabaj, Valeria; Nishimura, Sumiyo; Pérez, Claudio; Colombo, Alicia; Walter, Robin; Sierra, Felipe

2005-12-01

Plasma levels of kininogens increase with age in both rats and humans. Kininogens are inhibitors of cysteine proteinases, and filarial cysteine proteinase inhibitors (cystatins) reduce the proliferation of T cells. We evaluated whether T-kininogen (T-KG) might mimic this effect, and here we present data indicating that exposure of either rat splenocytes or Jurkat cells to purified T-KG results in inhibition of both ERK activation and [(3)H]-thymidine incorporation, both basal and in response to ConA or PHA. Interestingly, T-KG did not impair [(3)H]-thymidine incorporation in response to IL-2, which requires primarily the activation of the JNK and Jak/STAT pathways. These effects were neither the consequence of increased cell death, nor required the activity of kinin receptors. Furthermore, when T cell receptor proximal events were bypassed by the use of PMA plus Calcium ionophore, T-KG no longer inhibited ERK activation, suggesting that inhibition occurs upstream of these events, possibly at the level of membrane associated signal transduction molecules. We conclude that, like filarial cystatins, T-KG inhibits ERK-dependent T cell proliferation, and these observations suggest a possible role for T-KG in immunosenescence.

Human and Animal Dirofilariasis: the Emergence of a Zoonotic Mosaic

PubMed Central

Siles-Lucas, Mar; Morchón, Rodrigo; González-Miguel, Javier; Mellado, Isabel; Carretón, Elena; Montoya-Alonso, Jose Alberto

2012-01-01

Summary: Dirofilariasis represents a zoonotic mosaic, which includes two main filarial species (Dirofilaria immitis and D. repens) that have adapted to canine, feline, and human hosts with distinct biological and clinical implications. At the same time, both D. immitis and D. repens are themselves hosts to symbiotic bacteria of the genus Wolbachia, the study of which has resulted in a profound shift in the understanding of filarial biology, the mechanisms of the pathologies that they produce in their hosts, and issues related to dirofilariasis treatment. Moreover, because dirofilariasis is a vector-borne transmitted disease, their distribution and infection rates have undergone significant modifications influenced by global climate change. Despite advances in our knowledge of D. immitis and D. repens and the pathologies that they inflict on different hosts, there are still many unknown aspects of dirofilariasis. This review is focused on human and animal dirofilariasis, including the basic morphology, biology, protein composition, and metabolism of Dirofilaria species; the climate and human behavioral factors that influence distribution dynamics; the disease pathology; the host-parasite relationship; the mechanisms involved in parasite survival; the immune response and pathogenesis; and the clinical management of human and animal infections. PMID:22763636

Cardiac manifestations of parasitic diseases.

PubMed

Nunes, Maria Carmo P; Guimarães Júnior, Milton Henriques; Diamantino, Adriana Costa; Gelape, Claudio Leo; Ferrari, Teresa Cristina Abreu

2017-05-01

The heart may be affected directly or indirectly by a variety of protozoa and helminths. This involvement may manifest in different ways, but the syndromes resulting from impairment of the myocardium and pericardium are the most frequent. The myocardium may be invaded by parasites that trigger local inflammatory response with subsequent myocarditis or cardiomyopathy, as occurs in Chagas disease, African trypanosomiasis, toxoplasmosis, trichinellosis and infection with free-living amoebae. In amoebiasis and echinococcosis, the pericardium is the structure most frequently involved with consequent pericardial effusion, acute pericarditis, cardiac tamponade or constrictive pericarditis. Chronic hypereosinophilia due to helminth infections, especially filarial infections, has been associated with the development of tropical endomyocardial fibrosis, a severe form of restrictive cardiomyopathy. Schistosomiasis-associated lung vasculature involvement may cause pulmonary hypertension (PH) and cor pulmonale Tropical pulmonary eosinophilia, which is characterised by progressive interstitial fibrosis and restrictive lung disease, may lead to PH and its consequences may occur in the course of filarial infections. Intracardiac rupture of an Echinococcus cyst can cause membrane or secondary cysts embolisation to the lungs or organs supplied by the systemic circulation. Although unusual causes of cardiac disease outside the endemic areas, heart involvement by parasites should be considered in the differential diagnosis especially of myocardial and/or pericardial diseases of unknown aetiology in both immunocompetent and immunocompromised individuals. In this review, we updated and summarised the current knowledge on the major heart diseases caused by protozoan and metazoan parasites, which either involve the heart directly or otherwise influence the heart adversely. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Evaluating the sustainability, scalability, and replicability of an STH transmission interruption intervention: The DeWorm3 implementation science protocol.

PubMed

Means, Arianna Rubin; Ajjampur, Sitara S R; Bailey, Robin; Galactionova, Katya; Gwayi-Chore, Marie-Claire; Halliday, Katherine; Ibikounle, Moudachirou; Juvekar, Sanjay; Kalua, Khumbo; Kang, Gagandeep; Lele, Pallavi; Luty, Adrian J F; Pullan, Rachel; Sarkar, Rajiv; Schär, Fabian; Tediosi, Fabrizio; Weiner, Bryan J; Yard, Elodie; Walson, Judd

2018-01-01

Hybrid trials that include both clinical and implementation science outcomes are increasingly relevant for public health researchers that aim to rapidly translate study findings into evidence-based practice. The DeWorm3 Project is a series of hybrid trials testing the feasibility of interrupting the transmission of soil transmitted helminths (STH), while conducting implementation science research that contextualizes clinical research findings and provides guidance on opportunities to optimize delivery of STH interventions. The purpose of DeWorm3 implementation science studies is to ensure rapid and efficient translation of evidence into practice. DeWorm3 will use stakeholder mapping to identify individuals who influence or are influenced by school-based or community-wide mass drug administration (MDA) for STH and to evaluate network dynamics that may affect study outcomes and future policy development. Individual interviews and focus groups will generate the qualitative data needed to identify factors that shape, contextualize, and explain DeWorm3 trial outputs and outcomes. Structural readiness surveys will be used to evaluate the factors that drive health system readiness to implement novel interventions, such as community-wide MDA for STH, in order to target change management activities and identify opportunities for sustaining or scaling the intervention. Process mapping will be used to understand what aspects of the intervention are adaptable across heterogeneous implementation settings and to identify contextually-relevant modifiable bottlenecks that may be addressed to improve the intervention delivery process and to achieve intervention outputs. Lastly, intervention costs and incremental cost-effectiveness will be evaluated to compare the efficiency of community-wide MDA to standard-of-care targeted MDA both over the duration of the trial and over a longer elimination time horizon.

A survey of seasonal patterns in strongyle faecal worm egg counts of working equids of the central midlands and lowlands, Ethiopia.

PubMed

Getachew, M; Feseha, G; Trawford, A; Reid, S W J

2008-12-01

A study was conducted for two consecutive years (1998-1999) to determine the seasonal patterns of strongyle infection in working donkeys of Ethiopia. For the purpose 2385 donkeys from midland and lowland areas were examined for the presence of parasitic ova. A hundred percent prevalence of strongyle infection with similar seasonal pattern of strongyle faecal worm egg output was obtained in all study areas. However, seasonal variations in the number of strongyle faecal worm egg output were observed in all areas. The highest mean faecal worm egg outputs were recorded during the main rainy season (June to October) in both years in all areas. Although an increase in the mean strongyle faecal egg output was obtained in the short rainy season (March-April) followed by a drop in the short dry season (May), there was no statistically significant difference between the short rainy season and long dry season (Nov-Feb) (P > 0.05). A statistically significant difference however, was obtained between the main rainy season and short rainy season, and between the main rainy season and dry season (P < 0.05). Based on the results obtained it is suggested that the most economical and effective control of strongyles can be achieved by strategic deworming programme during the hot dry pre-main rainy season (May), when the herbage coverage is scarce and helminthologically 'sterile', and the arrested development of the parasites is suppose to be terminating. This could insure the greatest proportion of the existing worm population to be exposed to anthelmintic and also reduces pasture contamination and further infection in the subsequent wet season.

From Flowers to Worms: Understanding Nature's Cycle.

ERIC Educational Resources Information Center

Texas Child Care, 1995

1995-01-01

Gardening helps children learn how plants sprout, grow, bloom, and then wither away, leaving seeds behind. Participating in this natural process allows children to experience the stages of life. Suggested gardening activities include studying dandelions, focusing on culture for garden plant selection, and constructing a worm box or worm terrarium…

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Well formed. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv...) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v) Internal...) Carefully packed; (v) Fairly clean; and, (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Well formed. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv...) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v) Internal...) Carefully packed; (v) Fairly clean; and, (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii...

Local structure of numerically generated worm hole spacetime.

NASA Astrophysics Data System (ADS)

Siino, M.

The author investigates the evolution of the apparent horizons in a numerically gererated worm hole spacetime. The behavior of the apparent horizons is affected by the dynamics of the matter field. By using the local mass of the system, he interprets the evolution of the worm hole structure.

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2011 CFR

2011-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

7 CFR 51.2335 - Grades.

Code of Federal Regulations, 2010 CFR

2010-01-01

...: (i) Worm holes; (ii) Broken skins which are not healed; (iii) Sunscald; (iv) Freezing injury; (v...) Carefully packed; (v) Clean; and, (vi) Fairly well formed. (2) Free From: (i) Worm holes; (ii) Broken skins..., (vi) Not badly misshapen. (2) Free From: (i) Worm holes; (ii) Broken skins which are not healed; (iii...

Guinea worm (Dracunculus medinensis) eradication: a pilot study conducted at the Ohaukwu Local Government Areas, Ebonyi State, Nigeria, West Africa.

PubMed

Ogamdi, S O; Onwe, F

2001-01-01

The incidence and the prevalence of Guinea worm disease, a major cause of disability and a frequent cause of serious permanent deformity, were both drastically reduced in Ohaukwu Local Government Communities, with the provision (through bore holes) of a safer form of drinking water. Since 1986, the Carter Center program has been working to eradicate Guinea worm. The bore holes were dug through the Wasatan Project, a Japanese-funded grant awarded to the Enugu State Ministry of Health to help provide safer drinking water in the local communities. Bore holes were dug in several communities in Ohaukwu Local Government Areas between January 1991 and June 1991. The number of Guinea worm cases in the selected communities was ascertained and recorded by health workers. There was more than a 90% reduction in the number of Guinea worm (Dracunculus medinensis) cases after one year. Data collection began in June 1991, shortly after the completion of bore holes in the selected communities. By December 1998, when one of the villages was spot checked for Guinea worm infection, no active case was found. There is a need for post evaluation of all the villages studied to determine the current prevalence of Guinea worm disease.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide.

PubMed

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-05-10

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

PubMed Central

Kim, Gun-Hee; Lee, Jeong-Won; Seo, Tae-Il

2013-01-01

Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE) analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %). The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents. PMID:28809248

Keeping track of worm trackers.

PubMed

Husson, Steven J; Costa, Wagner Steuer; Schmitt, Cornelia; Gottschalk, Alexander

2013-02-22

C. elegans is used extensively as a model system in the neurosciences due to its well defined nervous system. However, the seeming simplicity of this nervous system in anatomical structure and neuronal connectivity, at least compared to higher animals, underlies a rich diversity of behaviors. The usefulness of the worm in genome-wide mutagenesis or RNAi screens, where thousands of strains are assessed for phenotype, emphasizes the need for computational methods for automated parameterization of generated behaviors. In addition, behaviors can be modulated upon external cues like temperature, O(subscript)2(/subscript) and CO(subscript)2(/subscript) concentrations, mechanosensory and chemosensory inputs. Different machine vision tools have been developed to aid researchers in their efforts to inventory and characterize defined behavioral "outputs". Here we aim at providing an overview of different worm-tracking packages or video analysis tools designed to quantify different aspects of locomotion such as the occurrence of directional changes (turns, omega bends), curvature of the sinusoidal shape (amplitude, body bend angles) and velocity (speed, backward or forward movement).

Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus.

PubMed

Laarhoven, Bob; Elissen, H J H; Temmink, H; Buisman, C J N

2016-01-01

An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates.

Agar Sediment Test for Assessing the Suitability of Organic Waste Streams for Recovering Nutrients by the Aquatic Worm Lumbriculus variegatus

PubMed Central

Laarhoven, Bob; Elissen, H. J. H.; Temmink, H.; Buisman, C. J. N.

2016-01-01

An agar sediment test was developed to evaluate the suitability of organic waste streams from the food industry for recovering nutrients by the aquatic worm Lumbriculus variegatus (Lv). The effects of agar gel, sand, and food quantities in the sediment test on worm growth, reproduction, and water quality were studied. Agar gel addition ameliorated growth conditions by reducing food hydrolysis and altering sediment structure. Best results for combined reproduction and growth were obtained with 0.6% agar-gel (20 ml), 10 g. fine sand, 40 g. coarse sand, and 105 mg fish food (Tetramin). With agar gel, ingestion and growth is more the result of addition of food in its original quality. Final tests with secondary potato starch sludge and wheat bran demonstrated that this test is appropriate for the comparison of solid feedstuffs and suspended organic waste streams. This test method is expected to be suitable for organic waste studies using other sediment dwelling invertebrates. PMID:26937632

Manufacture of threads with variable pitch by using noncircular gears

NASA Astrophysics Data System (ADS)

Slătineanu, L.; Dodun, O.; Coteață, M.; Coman, I.; Nagîț, G.; Beșliu, I.

2016-08-01

There are mechanical equipments in which shafts threaded with variable pitch are included. Such a shaft could be met in the case of worm specific to the double enveloping worm gearing. Over the years, the researchers investigated some possibilities to geometrically define and manufacture the shaft zones characterized by a variable pitch. One of the methods able to facilitate the manufacture of threads with variable pitch is based on the use of noncircular gears in the threading kinematic chain for threading by cutting. In order to design the noncircular gears, the mathematical law of pitch variation has to be known. An analysis of pitch variation based on geometrical considerations was developed in the case of a double enveloping globoid worm. Subsequently, on the bases of a proper situation, a numerical model was determined. In this way, an approximately law of pitch variation was determined and it could be taken into consideration when designing the noncircular gears included in the kinematic chain of the cutting machine tool.

Parasitic peptides! The structure and function of neuropeptides in parasitic worms.

PubMed

Day, T A; Maule, A G

1999-01-01

Parasitic worms come from two very different phyla-Platyhelminthes (flatworms) and Nematoda (roundworms). Although both phyla possess nervous systems with highly developed peptidergic components, there are key differences in the structure and action of native neuropeptides in the two groups. For example, the most abundant neuropeptide known in platyhelminths is the pancreatic polypeptide-like neuropeptide F, whereas the most prevalent neuropeptides in nematodes are FMRFamide-related peptides (FaRPs), which are also present in platyhelminths. With respect to neuropeptide diversity, platyhelminth species possess only one or two distinct FaRPs, whereas nematodes have upwards of 50 unique FaRPs. FaRP bioactivity in platyhelminths appears to be restricted to myoexcitation, whereas both excitatory and inhibitory effects have been reported in nematodes. Recently interest has focused on the peptidergic signaling systems of both phyla because elucidation of these systems will do much to clarify the basic biology of the worms and because the peptidergic systems hold the promise of yielding novel targets for a new generation of antiparasitic drugs.

Linking spatially distributed biogeochemical data with a two-host life-cycle pathogen:A model of whirling disease dynamics in salmonid fishes in the Intermountain West

NASA Astrophysics Data System (ADS)

Fytilis, N.; Lamb, R.; Stevens, L.; Morrissey, L. A.; Kerans, B.; Rizzo, D. M.

2010-12-01

Fish diseases are often caused by waterborne parasites, making them ideal systems for modeling the non-linear relationships between biogeochemical features and disease dynamics. Myxobolus cerebralis, the causative agent of whirling disease, has been a major contributor to the loss of wild rainbow trout populations in numerous streams within the Intermountain West (Colorado, Idaho, Montana, Utah, Wyoming). The parasite alternates between an invertebrate and vertebrate host, being transmitted between the sediment feeding worm T.Tubifex and salmonid fishes. A greater understanding of the linkage between biological stream integrity, geomorphic features, water quality parameters and whirling disease risk is needed to improve current management techniques. Biodiversity and abundance of the worm communities are influenced by biogeochemical features and linked to disease severity in fish. We collected and identified ~700 worms from eight sites using molecular genetic probes and a taxonomic key. Additionally, ~1700 worms were identified using only a taxonomic key. Our work examines the links between worm community structure and biogeochemical features. We use a modified Self-Organizing-Map (SOM), which is a non-parametric clustering method based on an artificial neural network (ANN). Clustering methods are particularly attractive for exploratory data analyses because they do not require either the target number of groupings or the data structure be specified at the outset. ANN clustering methods have been shown to be more robust and to account for more data variability than traditional methods when applied to clustering geo-hydrochemical and microbiological datasets. The SOM highlights spatial variation of worm community structure between sites; and is used in tandem with expert knowledge (Lamb and Kerans) of local worm communities and a Madison River, MT physiochemical dataset (GIS-derived layers, water quality parameters). We iteratively clustered the physiochemical data and then compared the resulting groups to site-specific worm community structures. The SOM mined patterns from this highly dimensional data and produced 2-D visualizations of the data clusters. This process, in concert with iterative feedback with stream ecologists, led to the adaptation of new nonlinear relations and suggests new subsets of input parameters that guide the next round of SOM simulations, expand the pool of concepts, hone existing hypotheses, generate new hypotheses, and so on. The methodologies developed here helped mine the relationship between dominant biogeochemical features and the distribution of an alternative host of a vertebrate disease. This collaboration between modelers, field ecologists and geneticists will prove useful in guiding future data gathering and modeling efforts. (i.e., identifying missing data gaps and sampling frequency), and will enable more effective, high-volume hypothesis generation that, in turn, will better guide complex experimental designs providing integrated understanding of disease dynamics.

A Tissue-Specific Approach to the Analysis of Metabolic Changes in Caenorhabditis elegans

PubMed Central

Pujol, Claire; Ipsen, Sabine; Brodesser, Susanne; Mourier, Arnaud; Tolnay, Markus; Frank, Stephan; Trifunović, Aleksandra

2011-01-01

The majority of metabolic principles are evolutionarily conserved from nematodes to humans. Caenorhabditis elegans has widely accelerated the discovery of new genes important to maintain organismic metabolic homeostasis. Various methods exist to assess the metabolic state in worms, yet they often require large animal numbers and tend to be performed as bulk analyses of whole worm homogenates, thereby largely precluding a detailed studies of metabolic changes in specific worm tissues. Here, we have adapted well-established histochemical methods for the use on C. elegans fresh frozen sections and demonstrate their validity for analyses of morphological and metabolic changes on tissue level in wild type and various mutant strains. We show how the worm presents on hematoxylin and eosin (H&E) stained sections and demonstrate their usefulness in monitoring and the identification of morphological abnormalities. In addition, we demonstrate how Oil-Red-O staining on frozen worm cross-sections permits quantification of lipid storage, avoiding the artifact-prone fixation and permeabilization procedures of traditional whole-mount protocols. We also adjusted standard enzymatic stains for respiratory chain subunits (NADH, SDH, and COX) to monitor metabolic states of various C. elegans tissues. In summary, the protocols presented here provide technical guidance to obtain robust, reproducible and quantifiable tissue-specific data on worm morphology as well as carbohydrate, lipid and mitochondrial energy metabolism that cannot be obtained through traditional biochemical bulk analyses of worm homogenates. Furthermore, analysis of worm cross-sections overcomes the common problem with quantification in three-dimensional whole-mount specimens. PMID:22162770

Migratory response of Echinostoma caproni (Digenea: Echinostomatidae) to feeding by ICR mice.

PubMed

Platt, Thomas R; Quintana, Guadalupe; Rodriguez, Arianne E; Zelmer, Derek A

2013-04-01

The migratory response of Echinostoma caproni to host feeding was examined in female ICR mice. Thirty-six mice were each infected with 20 metacercariae of E. caproni . Twenty-eight days post-infection, food, but not water, was withheld for 24 hr. Mice were haphazardly divided into 4 groups of 9, and each group received one of the following treatments: (1) 0.25 g glucose, (2) access to standard lab chow, (3) 0.5 ml saline, and (4) continued fasting. Three mice from each treatment group were killed 1, 2, and 4 hr post-treatment. The intestine of each mouse was removed, flash-frozen, and stored in a conventional freezer for later examination. Intestines were partially thawed, measured, and opened longitudinally, and the position of each worm, or worm cluster was measured. The intestine was divided into equal 5% segments based on the initial measurement and locations of worms, and worm clusters were recorded from the appropriate section of the intestine for analysis. There was no significant effect of treatment in the position of worms at 1 hr. There was a posterior shift in worm position in all treatment groups at 2 hr, except in the saline-treated mice; however, only worms in the glucose-fed mice were significantly posterior to the unfed controls. From 2 to 4 hr, there was a significant anterior movement of worms in both the glucose and chow-fed mice. The data strongly suggest that E. caproni responds to the initiation of gastric activity of the host by migrating anteriorly in the ileum. The specific stimulus for this migration is unknown.

Genetic selection of low fertile Onchocerca volvulus by ivermectin treatment.

PubMed

Bourguinat, Catherine; Pion, Sébastien D S; Kamgno, Joseph; Gardon, Jacques; Duke, Brian O L; Boussinesq, Michel; Prichard, Roger K

2007-08-30

Onchocerca volvulus is the causative agent of onchocerciasis, or "river blindness". Ivermectin has been used for mass treatment of onchocerciasis for up to 18 years, and recently there have been reports of poor parasitological responses to the drug. Should ivermectin resistance be developing, it would have a genetic basis. We monitored genetic changes in parasites obtained from the same patients before use of ivermectin and following different levels of ivermectin exposure. O. volvulus adult worms were obtained from 73 patients before exposure to ivermectin and in the same patients following three years of annual or three-monthly treatment at 150 microg/kg or 800 microg/kg. Genotype frequencies were determined in beta-tubulin, a gene previously found to be linked to ivermectin selection and resistance in parasitic nematodes. Such frequencies were also determined in two other genes, heat shock protein 60 and acidic ribosomal protein, not known to be linked to ivermectin effects. In addition, we investigated the relationship between beta-tubulin genotype and female parasite fertility. We found a significant selection for beta-tubulin heterozygotes in female worms. There was no significant selection for the two other genes. Quarterly ivermectin treatment over three years reduced the frequency of the beta-tubulin "aa" homozygotes from 68.6% to 25.6%, while the "ab" heterozygotes increased from 20.9% to 69.2% in the female parasites. The female worms that were homozygous at the beta-tubulin locus were more fertile than the heterozygous female worms before treatment (67% versus 37%; p = 0.003) and twelve months after the last dose of ivermectin in the groups treated annually (60% versus 17%; p<0.001). Differences in fertility between heterozygous and homozygous worms were less apparent three months after the last treatment in the groups treated three-monthly. The results indicate that ivermectin is causing genetic selection on O. volvulus. This genetic selection is associated with a lower reproductive rate in the female parasites. We hypothesize that this genetic selection indicates that a population of O. volvulus, which is more tolerant to ivermectin, is being selected. This selection could have implications for the development of ivermectin resistance in O. volvulus and for the ongoing onchocerciasis control programmes.

An Unusual Foreign Body in the Urinary Bladder Mimicking a Parasitic Worm

PubMed Central

Schmitt, Bryan H.; Feder, Marc T.; Rokke, Denise L.; Moyer, Thomas P.

2012-01-01

We report an unusual case of a foreign body removed from the urinary bladder of a 63-year-old male which mimicked a parasitic worm. The foreign body was identified as an artificial fishing worm by morphological comparison to a similar commercially produced product and by infrared spectrum analysis. PMID:22535991

Helminth infections predispose mice to pneumococcal pneumonia but not to other pneumonic pathogens.

PubMed

Apiwattanakul, Nopporn; Thomas, Paul G; Kuhn, Raymond E; Herbert, De'Broski R; McCullers, Jonathan A

2014-10-01

Pneumonia is the leading killer of children worldwide. Here, we report that helminth-infected mice develop fatal pneumonia when challenged with Streptococcus pneumoniae. Mice were chronically infected with either the flatworm Taenia crassiceps or the roundworm Heligmosomoides polygyrus. Upon challenge with a pneumonic type 3 strain of S. pneumoniae (A66.1), the worm-infected mice developed pneumonia at a rate and to a degree higher than age-matched control mice as measured by bioluminescent imaging and lung titers. This predisposition to pneumonia appears to be specific to S. pneumoniae, as worm-infected mice did not show evidence of increased morbidity when challenged with a lethal dose of influenza virus or sublethal doses of Staphylococcus aureus or Listeria monocytogenes. The defect was also present when worm-infected mice were challenged with a type 2 sepsis-causing strain (D39); an increased rate of pneumonia, decreased survival, and increased lung and blood titers were found. Pneumococcal colonization and immunity against acute otitis media were unaffected. Anti-helminthic treatment in the H. polygyrus model reversed this susceptibility. We conclude that helminth coinfection predisposes mice to fatal pneumococcal pneumonia by promoting increased outgrowth of bacteria in the lungs and blood. These data have broad implications for the prevention and treatment for pneumonia in the developing world, where helminth infections are endemic and pneumococcal pneumonia is common.

The effects of stage-specific selection on the development of benzimidazole resistance in Haemonchus contortus in sheep.

PubMed

Taylor, M A; Hunt, K R; Goodyear, K L

2002-10-16

Resistance to the benzimidazole (BDZ) class of anthelmintics in nematodes of sheep has become a common and global phenomenon. The rate at which the selection process and development of resistance occurs is influenced by a number of factors. Of these, the effects of stage-specific exposures to anthelmintic were investigated with a BDZ-resistant strain of Haemonchus contortus (HCR) over five parasite generations. Sheep were infected at each generation with the HCR strain and were treated with thiabendazole (TBZ), either 5 days post-infection (p.i.) (larval line), 21 days p.i. (adult line), or left untreated (no selection line). Additionally eggs from each generation were exposed to TBZ (egg line). Geometric worm burdens were calculated from post-mortem worm counts, both at the start of the study, and after the final selection studies for each of the selection lines. Egg hatch assays (EHAs) were also conducted throughout the study. All data relating to worm burdens and EHAs for each generation were analysed by linear regression to produce dose titration curves and lethal dose(50) (LD(50)) values for each of the selection lines. Over the five generations, LD(50) values on dose-response were increased and worm survival occurred at higher dose rates of TBZ irrespective of the parasite stage exposed to treatment. A similar picture was seen with ED(50) values, which showed a fluctuating but generally upward trend for each of the three selection lines. In contrast, LD(50) and ED(50) values were decreased in the no selection line, indicating some degree of reversion albeit to levels still considered to be BDZ-resistant.

A Multiscale Model for the World's First Parasitic Disease Targeted for Eradication: Guinea Worm Disease

PubMed Central

Netshikweta, Rendani

2017-01-01

Guinea worm disease (GWD) is both a neglected tropical disease and an environmentally driven infectious disease. Environmentally driven infectious diseases remain one of the biggest health threats for human welfare in developing countries and the threat is increased by the looming danger of climate change. In this paper we present a multiscale model of GWD that integrates the within-host scale and the between-host scale. The model is used to concurrently examine the interactions between the three organisms that are implicated in natural cases of GWD transmission, the copepod vector, the human host, and the protozoan worm parasite (Dracunculus medinensis), and identify their epidemiological roles. The results of the study (through sensitivity analysis of R0) show that the most efficient elimination strategy for GWD at between-host scale is to give highest priority to copepod vector control by killing the copepods in drinking water (the intermediate host) by applying chemical treatments (e.g., temephos, an organophosphate). This strategy should be complemented by health education to ensure that greater numbers of individuals and communities adopt behavioural practices such as voluntary reporting of GWD cases, prevention of GWD patients from entering drinking water bodies, regular use of water from safe water sources, and, in the absence of such water sources, filtering or boiling water before drinking. Taking into account the fact that there is no drug or vaccine for GWD (interventions which operate at within-host scale), the results of our study show that the development of a drug that kills female worms at within-host scale would have the highest impact at this scale domain with possible population level benefits that include prevention of morbidity and prevention of transmission. PMID:28808479

On-chip functional neuroimaging with mechanical stimulation in Caenorhabditis elegans larvae for studying development and neural circuits.

PubMed

Cho, Yongmin; Oakland, David N; Lee, Sol Ah; Schafer, William R; Lu, Hang

2018-02-13

Mechanosensation is fundamentally important for the abilities of an organism to experience touch, hear sounds, and maintain balance. Caenorhabditis elegans is a powerful system for studying mechanosensation as this worm is well suited for in vivo functional imaging of neurons. Many years of research using labor-intensive methods have generated a wealth of knowledge about mechanosensation in C. elegans, and the recent microfluidic-based platforms continue to push the boundary for this field. However, developmental aspects of sensory biology, including mechanosensation, are still not fully understood. One current bottleneck is the difficulty in assaying larvae because they are much smaller than adult worms. Microfluidic devices with features small enough for larvae, especially actuators for the delivery of mechanical stimulation, are difficult to design and fabricate. Here, we present a series of automatic microfluidic platforms that allow for in vivo functional imaging of C. elegans responding to controlled mechanical stimulation at different developmental stages. Using a novel fabrication method, we designed highly deformable pneumatically actuated on-chip structures that can deliver mechanical stimulation to larval worms. The PDMS actuator allows for quantitatively controlled mechanical stimulation of both gentle and harsh touch neurons, by simply changing the actuation pressure, which makes this device easily translatable to other labs. We validated the design and utility of our systems with studies of the functional role of mechanosensory neurons in developing worms; we showed that gentle and harsh touch neurons function similarly in early larvae as they do in the adult stage, which would not have been possible previously. Finally, we investigated the effect of a sleep-like state on neuronal responses by imaging C. elegans in the lethargus state.

Anthelmintic Activity of Crude Extract and Essential Oil of Tanacetum vulgare (Asteraceae) against Adult Worms of Schistosoma mansoni

PubMed Central

Godinho, Loyana Silva; Aleixo de Carvalho, Lara Soares; Barbosa de Castro, Clarissa Campos; Dias, Mirna Meana; Pinto, Priscila de Faria; Crotti, Antônio Eduardo Miller; Pinto, Pedro Luiz Silva; de Moraes, Josué; Da Silva Filho, Ademar A.

2014-01-01

Schistosomiasis, a parasitic disease caused by trematode flatworms of the genus Schistosoma, affects more than 200 million people worldwide, and its control is dependent on a single drug, praziquantel. Tanacetum vulgare (Asteraceae) is used in folk medicine as a vermifuge. This study aimed to investigate the in vitro schistosomicidal activity of the crude extract (TV) and the essential oil (TV-EO) from the aerial parts of T. vulgare. TV-EO was obtained by hydrodistillation and analyzed by GC/MS, which allowed the identification of β-thujone (84.13%) as the major constituent. TV and TV-EO, at 200 μg/mL, decreased motor activity and caused 100% mortality of all adult worms. At 100 and 50 μg/mL, only TV caused death of all adult worms, while TV-EO was inactive. TV (200 μg/mL) was also able to reduce viability and decrease production of developed eggs. Confocal laser scanning microscopy showed morphological alterations in the tegument of the S. mansoni surface after incubation with TV (50 and 100 μg/mL). Quantitative analysis on the schistosomes tegument showed that TV caused changes in the numbers of tubercles of S. mansoni male worms in a dose-dependent manner. The findings suggest that T. vulgare is a potential source of schistosomicidal compounds. PMID:24672320

Scanning electron microscopic study of the tegumental surface of adult Schistosoma sinensium.

PubMed

Kruatrachue, M; Upatham, E S; Sahaphong, S; Tongthong, T; Khunborivan, V

1983-12-01

The SEM study of tegumental surface of adult Schistosoma sinensium reveals that the male tegument lacks tubercles or bosses; instead it is corrugated with small pits or perforated ridges. On the dorsal surface, spines are present whose number and size progressively increase towards the posterior end of the body. In addition, there are three types of papillae interspersed among the ridges and spines. The first type of papillae has crater-like holes surrounded by a circular doughnut-shaped elevation; some are ciliated and others are non-ciliated. They are generally found on the dorsal and ventral surfaces. The second is sensory papillae which are hemispherical in shape bearing apical cilia. They are found to be concentrated around the oral sucker and on the posterior end of the worm. The third is fungiform papillae without cilia which are found on the posterior end. There are short spines present on the tegument lining the gynecophoral canal of the male worm. The tegument of the female S. sinensium is corrugated with ridges on the ventral surface. Small spines are present on the anterior portion of the dorsal surface. They become larger and increased in number towards the posterior end of the worm. The three types of papillae are present but they are much fewer and less developed than those in the male worm.

Echinococcus multilocularis coproantigen detection by enzyme-linked immunosorbent assay in fox, dog, and cat populations.

PubMed

Deplazes, P; Alther, P; Tanner, I; Thompson, R C; Eckert, J

1999-02-01

A sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Echinococcus multilocularis coproantigens (EM-ELISA) was developed with polyclonal rabbit (solid phase) and chicken egg (catching) antibodies that were directed against E. multilocularis coproantigens and somatic worm antigens, respectively. In experimentally infected dogs and cats, coproantigens were first detectable 6-17 days postinfection (PI) in samples of 8 dogs (worm burdens at necropsy: 6,330-43,200) and from 11 days PI onward in samples of 5 cats infected with 20-6,833 worms. After anthelmintic treatment of 4 dogs and 5 cats at day 20 PI, coproantigen excretion disappeared within 3-5 days. The sensitivity of the ELISA was 83.6% in 55 foxes infected with 4-60,000 E. multilocularis, but reached 93.3% in the 45 foxes harboring more than 20 worms. The EM-ELISA was used in surveys of "normal" dog and cat populations in Switzerland. Among 660 dogs and 263 cats, 5 dogs and 2 cats exhibited a positive reaction. In 2 of these dogs (0.30%) and 1 cat (0.38%), intestinal E. multilocularis infections were confirmed by necropsy, polymerase chain reaction PCR, or both. The specificites of the ELISA in these groups were found to be 99.5% and 99.6%, respectively, if positive ELISA results that could not be confirmed by other methods were classified as "false positive" reactions.

Intestinal helminths of a landlocked ringed seal (Phoca hispida saimensis) population in eastern Finland.

PubMed

Sinisalo, Tuula; Kunnasranta, Mervi; Valtonen, E Tellervo

2003-09-01

A small, landlocked, endangered ringed seal (Phoca hispida saimensis) population lives as a postglacial relict in Lake Saimaa in eastern Finland. In this study, the intestinal metazoans were examined from a total of 61 Saimaa seals found dead from 1981 to 2001. The helminth fauna was very depauperate. Only one acanthocephalan species, Corynosoma magdaleni, has been able to survive during isolation in the freshwater environment. In addition, only two cestode species were found: Diphyllobothrium ditretum and Schistocephalus sp. However, neither of these larvae developed in the ringed seals. As the newborn pups of Saimaa seals are nursed for about 2 months only one of them was infected by C. magdaleni. At 2-5 months the pups harboured worms; however, the mean intensity did not rise distinctively until the seals were adults. C. magdaleni infection increased with increasing age and the abundances were significantly different between the age groups. There was no correlation between the number of parasites and the adult seal body weight; however, seals weighing 36 kg or more carried the majority of the worms. The distribution of the parasites was aggregated; six seals carried 65% (n=1,182) of all worms (total n=1,809) and 26 seals were uninfected. Variation in the number of worms in individual seals may indicate differences in feeding behaviour and in the diet of seals, and/or variation in the immune status of the seals.

Functional Mapping of Protein Kinase A Reveals Its Importance in Adult Schistosoma mansoni Motor Activity

PubMed Central

de Saram, Paulu S. R.; Ressurreição, Margarida; Davies, Angela J.; Rollinson, David; Emery, Aidan M.; Walker, Anthony J.

2013-01-01

Cyclic AMP (cAMP)-dependent protein kinase/protein kinase A (PKA) is the major transducer of cAMP signalling in eukaryotic cells. Here, using laser scanning confocal microscopy and ‘smart’ anti-phospho PKA antibodies that exclusively detect activated PKA, we provide a detailed in situ analysis of PKA signalling in intact adult Schistosoma mansoni, a causative agent of debilitating human intestinal schistosomiasis. In both adult male and female worms, activated PKA was consistently found associated with the tegument, oral and ventral suckers, oesophagus and somatic musculature. In addition, the seminal vesicle and gynaecophoric canal muscles of the male displayed activated PKA whereas in female worms activated PKA localized to the ootype wall, the ovary, and the uterus particularly around eggs during expulsion. Exposure of live worms to the PKA activator forskolin (50 µM) resulted in striking PKA activation in the central and peripheral nervous system including at nerve endings at/near the tegument surface. Such neuronal PKA activation was also observed without forskolin treatment, but only in a single batch of worms. In addition, PKA activation within the central and peripheral nervous systems visibly increased within 15 min of worm-pair separation when compared to that observed in closely coupled worm pairs. Finally, exposure of adult worms to forskolin induced hyperkinesias in a time and dose dependent manner with 100 µM forskolin significantly increasing the frequency of gross worm movements to 5.3 times that of control worms (P≤0.001). Collectively these data are consistent with PKA playing a central part in motor activity and neuronal communication, and possibly interplay between these two systems in S. mansoni. This study, the first to localize a protein kinase when exclusively in an activated state in adult S. mansoni, provides valuable insight into the intricacies of functional protein kinase signalling in the context of whole schistosome physiology. PMID:23326613

Preparation and Cross-Linking of All-Acrylamide Diblock Copolymer Nano-Objects via Polymerization-Induced Self-Assembly in Aqueous Solution

PubMed Central

2017-01-01

Various carboxylic acid-functionalized poly(N,N-dimethylacrylamide) (PDMAC) macromolecular chain transfer agents (macro-CTAs) were chain-extended with diacetone acrylamide (DAAM) by reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization at 70 °C and 20% w/w solids to produce a series of PDMAC–PDAAM diblock copolymer nano-objects via polymerization-induced self-assembly (PISA). TEM studies indicate that a PDMAC macro-CTA with a mean degree of polymerization (DP) of 68 or higher results in the formation of well-defined spherical nanoparticles with mean diameters ranging from 40 to 150 nm. In contrast, either highly anisotropic worms or polydisperse vesicles are formed when relatively short macro-CTAs (DP = 40–58) are used. A phase diagram was constructed to enable accurate targeting of pure copolymer morphologies. Dynamic light scattering (DLS) and aqueous electrophoresis studies indicated that in most cases these PDMAC–PDAAM nano-objects are surprisingly resistant to changes in either solution pH or temperature. However, PDMAC40–PDAAM99 worms do undergo partial dissociation to form a mixture of relatively short worms and spheres on adjusting the solution pH from pH 2–3 to around pH 9 at 20 °C. Moreover, a change in copolymer morphology from worms to a mixture of short worms and vesicles was observed by DLS and TEM on heating this worm dispersion to 50 °C. Postpolymerization cross-linking of concentrated aqueous dispersions of PDMAC–PDAAM spheres, worms, or vesicles was performed at ambient temperature using adipic acid dihydrazide (ADH), which reacts with the hydrophobic ketone-functionalized PDAAM chains. The formation of hydrazone groups was monitored by FT-IR spectroscopy and afforded covalently stabilized nano-objects that remained intact on exposure to methanol, which is a good solvent for both blocks. Rheological studies indicated that the cross-linked worms formed a stronger gel compared to linear precursor worms. PMID:28260814

Post-embryonic development of Camallanus cotti (Nematoda: Camallanidae), with emphasis on growth of some taxonomically important somatic characters.

PubMed

Levsen, Arne; Berland, Bjørn

2002-01-01

In this paper, the quantitative post-embryonic development of the Asian freshwater fish nematode Camallanus cotti Fujita, 1927, is described. Larval and adult morphometrics were obtained by following the parasite's life cycle experimentally using copepods Macrocyclops albidus (Jurine) as intermediate host and guppies Poecilia reticulata (Peters), southern platyfish Xiphophorus maculatus (Günther) and paradise fish Macropodus opercularis (L.) as definitive host. Additionally, adult worms were obtained from heavily infected paradise fish imported from Singapore. It is suggested that the gradual change in proportions of the worm's somatic body parts reflects the specific ecological role of each developmental stage. The free-living infective first-stage larva seems to be adapted for transmission, as indicated by its relatively long tail, designed to generate host-attracting movements, and its non-functional intestine. The second- and third-stage larvae from the copepod intermediate host seem mainly to invest in trophic functionality, i.e., the development of the buccal capsule and the oesophagus, which are crucial structures for the worm's successful establishment in the definitive fish host. Once in the fish intestine, the larvae enter a period of considerable growth. After the fourth (i.e., last) moult, a 72% increase in average female body length occurs. This is accompanied by doubling the average vulva-tail tip distance and the average tail length. The length of the female hind body expands in an accelerating allometric fashion, and seems to be closely linked to the posterior-wards expansion of the uterus. In the males however, growth seems to cease after the final moult. We conclude that female post-maturational body size, but especially the length of the hind body and the tail, are closely related to reproductive state, i.e., the developmental stage of the offspring in the uterus, and, probably, the worms' age. Any future taxonomical studies of camallanids in general, and C. cotti in particular, should thus be aware of the reproductive state of the females used.

Study of the Formation and Solution Properties of Worm-Like Micelles Formed Using Both N-Hexadecyl-N-Methylpiperidinium Bromide-Based Cationic Surfactant and Anionic Surfactant

PubMed Central

Yan, Zhihu; Dai, Caili; Feng, Haishun; Liu, Yifei; Wang, Shilu

2014-01-01

The viscoelastic properties of worm-like micelles formed by mixing the cationic surfactant N-hexadecyl-N-methylpiperidinium bromide (C16MDB) with the anionic surfactant sodium laurate (SL) in aqueous solutions were investigated using rheological measurements. The effects of sodium laurate and temperature on the worm-like micelles and the mechanism of the observed shear thinning phenomenon and pseudoplastic behavior were systematically investigated. Additionally, cryogenic transmission electron microscopy images further ascertained existence of entangled worm-like micelles. PMID:25296131

Social behaviour and collective motion in plant-animal worms.

PubMed

Franks, Nigel R; Worley, Alan; Grant, Katherine A J; Gorman, Alice R; Vizard, Victoria; Plackett, Harriet; Doran, Carolina; Gamble, Margaret L; Stumpe, Martin C; Sendova-Franks, Ana B

2016-02-24

Social behaviour may enable organisms to occupy ecological niches that would otherwise be unavailable to them. Here, we test this major evolutionary principle by demonstrating self-organizing social behaviour in the plant-animal, Symsagittifera roscoffensis. These marine aceol flat worms rely for all of their nutrition on the algae within their bodies: hence their common name. We show that individual worms interact with one another to coordinate their movements so that even at low densities they begin to swim in small polarized groups and at increasing densities such flotillas turn into circular mills. We use computer simulations to: (i) determine if real worms interact socially by comparing them with virtual worms that do not interact and (ii) show that the social phase transitions of the real worms can occur based only on local interactions between and among them. We hypothesize that such social behaviour helps the worms to form the dense biofilms or mats observed on certain sun-exposed sandy beaches in the upper intertidal of the East Atlantic and to become in effect a super-organismic seaweed in a habitat where macro-algal seaweeds cannot anchor themselves. Symsagittifera roscoffensis, a model organism in many other areas in biology (including stem cell regeneration), also seems to be an ideal model for understanding how individual behaviours can lead, through collective movement, to social assemblages. © 2016 The Author(s).

Influence of ecological factors on prevalence of meningeal worm (Parelaphostrongylus tenuis infection in South Dakota, USA

USGS Publications Warehouse

Jacques, Christopher N.; Jenks, Jonathan A.; Grovenburg, Troy W.; Klaver, Robert W.; Dubay, Shelli A.

2015-01-01

The meningeal worm (Parelaphostrongylus tenuis) is a nematode parasite that commonly infects white-tailed deer (Odocoileus virginianus; WTD) throughout the deciduous forest biome and deciduous-coniferous ecotone of eastern and central North America; the species is not known to occur west of the grassland biome of central North America. We used county-specific prevalence data to evaluate potential effects of landscape and climatologic factors on the spatial distribution of meningeal worm infection in South Dakota, US. Probability of infection increased 4-fold between eastern and western South Dakota and 1.3-fold for each 1-cm increase in summer precipitation. Sixty-three percent of WTD had only a single worm in the cranium. Expansion of meningeal worm infection across western South Dakota may be inherently low due to the combined effects of arid climate and potential attributes of the Missouri River that limit regional movements by infected WTD. Use of landscape genetic analyses to identify potential relationships between landscape features and population genetic structure of infected deer and parasites may contribute to a greater understanding of regional heterogeneity in meningeal worm infection rates across South Dakota, particularly in counties adjacent to the Missouri River. Future research evaluating heterogeneity in prevalence and intensity of infection between fawn and yearling deer, and the potential role of yearling male deer as dispersal agents of meningeal worms across the Missouri River, also is warranted.

A decade of the World Register of Marine Species – General insights and experiences from the Data Management Team: Where are we, what have we learned and how can we continue?

PubMed Central

Vanhoorne, Bart; Decock, Wim; Vranken, Sofie; Lanssens, Thomas; Dekeyzer, Stefanie; Verfaille, Kevin; Horton, Tammy; Kroh, Andreas; Hernandez, Francisco; Mees, Jan

2018-01-01

The World Register of Marine Species (WoRMS) celebrated its 10th anniversary in 2017. WoRMS is a unique database: there is no comparable global database for marine species, which is driven by a large, global expert community, is supported by a Data Management Team and can rely on a permanent host institute, dedicated to keeping WoRMS online. Over the past ten years, the content of WoRMS has grown steadily, and the system currently contains more than 242,000 accepted marine species. WoRMS has not yet reached completeness: approximately 2,000 newly described species per year are added, and editors also enter the remaining missing older names–both accepted and unaccepted–an effort amounting to approximately 20,000 taxon name additions per year. WoRMS is used extensively, through different channels, indicating that it is recognized as a high-quality database on marine species information. It is updated on a daily basis by its Editorial Board, which currently consists of 490 taxonomic and thematic experts located around the world. Owing to its unique qualities, WoRMS has become a partner in many large-scale initiatives including OBIS, LifeWatch and the Catalogue of Life, where it is recognized as a high-quality and reliable source of information for marine taxonomy. PMID:29624577

Census of bacterial microbiota associated with the glacier ice worm Mesenchytraeus solifugus.

PubMed

Murakami, Takumi; Segawa, Takahiro; Bodington, Dylan; Dial, Roman; Takeuchi, Nozomu; Kohshima, Shiro; Hongoh, Yuichi

2015-03-01

The glacier ice worm, Mesenchytraeus solifugus, is a unique annelid, inhabiting only snow and ice in North American glaciers. Here, we analyzed the taxonomic composition of bacteria associated with M. solifugus based on the 16S rRNA gene. We analyzed four fixed-on-site and 10 starved ice worm individuals, along with glacier surface samples. In total, 1341 clones of 16S rRNA genes were analyzed for the ice worm samples, from which 65 bacterial phylotypes (99.0% cut-off) were identified. Of these, 35 phylotypes were closely related to sequences obtained from their habitat glacier and/or other components of cryosphere; whereas three dominant phylotypes were affiliated with animal-associated lineages of the class Mollicutes. Among the three, phylotype Ms-13 shared less than 89% similarity with database sequences and was closest to a gut symbiont of a terrestrial earthworm. Using fluorescence in situ hybridization, Ms-13 was located on the gut wall surface of the ice worms. We propose a novel genus and species, 'Candidatus Vermiplasma glacialis', for this bacterium. Our results raise the possibility that the ice worm has exploited indigenous glacier bacteria, while several symbiotic bacterial lineages have maintained their association with the ice worm during the course of adaptive evolution to the permanently cold environment. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Novel Therapeutics for Multiple Sclerosis Designed by Parasitic Worms.

PubMed

Dixit, Aakanksha; Tanaka, Akane; Greer, Judith M; Donnelly, Sheila

2017-10-13

The evolutionary response to endemic infections with parasitic worms (helminth) was the development of a distinct regulatory immune profile arising from the need to encapsulate the helminths while simultaneously repairing tissue damage. According to the old friend's hypothesis, the diminished exposure to these parasites in the developed world has resulted in a dysregulated immune response that contributes to the increased incidence of immune mediated diseases such as Multiple Sclerosis (MS). Indeed, the global distribution of MS shows an inverse correlation to the prevalence of helminth infection. On this basis, the possibility of treating MS with helminth infection has been explored in animal models and phase 1 and 2 human clinical trials. However, the possibility also exists that the individual immune modulatory molecules secreted by helminth parasites may offer a more defined therapeutic strategy.

 Grunting for worms: reactions of Diplocardia to seismic vibrations

Treesearch

M.A. Callaham

2009-01-01

Harvesting earthworms by a practice called 'worm grunting' is a widespread and profitable business in the southeastern USA. Although a variety of techniques are used, most involve rhythmically scraping a wooden stake driven into the ground, with a fiat metal object. A common assumption is that vibrations cause the worms to surface, but this phenomenon has not...

Caenorhabditis elegans utilizes dauer pheromone biosynthesis to dispose of toxic peroxisomal fatty acids for cellular homoeostasis

USDA-ARS?s Scientific Manuscript database

Caenorhabditis elegans secretes a dauer pheromone or daumone composed of ascarylose and a fatty acid side chain, perception of which enables worms to gauge depletion of food or a high worm population density. As a result, worms enter the dauer state, a specific developmental stage capable of surviv...

Worms in the College Classroom: More than Just a Composting Demonstration

ERIC Educational Resources Information Center

Kelley, Rebecca L.

2010-01-01

Although worm bins have been used by K-12 and nonformal educators for decades, there is little evidence of their use in postsecondary education. The ease of use, maintenance, affordability, portability, and diversity of scientific concepts that can be demonstrated with a worm bin make it a valuable tool in college science classrooms. The purpose…

Development of a CCTV system for welder training and monitoring of Space Shuttle Main Engine welds

NASA Technical Reports Server (NTRS)

Gordon, S. S.; Flanigan, L. A.; Dyer, G. E.

1987-01-01

A Weld Operator's Remote Monitoring System (WORMS) for remote viewing of manual and automatic GTA welds has been developed for use in Space Shuttle Main Engine (SSME) manufacturing. This system utilizes fiberoptics to transmit images from a receiving lens to a small closed-circuit television (CCTV) camera. The camera converts the image to an electronic signal, which is sent to a videotape recorder (VTR) and a monitor. The overall intent of this system is to provide a clearer, more detailed view of welds than is available by direct observation. This system has six primary areas of application: (1) welder training; (2) viewing of joint penetration; (3) viewing visually inaccessible welds; (4) quality control and quality assurance; (5) remote joint tracking and adjustment of variables in machine welds; and (6) welding research and development. This paper describes WORMS and how it applies to each application listed.

Photodynamic inactivation using curcuminoids and Photogem on caenorhabditis elegans

NASA Astrophysics Data System (ADS)

Albuquerque, Yulli R.; Pratavieira, Sebastião.; Bagnato, Vanderlei S.; Inada, Natalia M.; Souza, Larissa M.; Afonso, Ana; de Souza, Clovis W. O.; Oliveira, Kleber T.; Anibal, Fernanda F.

2018-02-01

Resistance to various anthelmintic drugs is reported in many animals and can become a severe problem for human and animal health. In this study, Photogem® and three curcuminoids compounds (curcumin, demethoxycurcumin, bisdemethoxycurcumin) were used as photosensitizers in the photodynamic inactivation (PDI) in the helminth model Caenorhabditis elegans to investigate the ability of this procedure to worm life cycle. Initially, the presence and location of the photosensitizers in the worm's body were verified by fluorescence confocal microscopy. Curcumin was deposited in the digestive tract and Photogem® along the body of the animal in the incubation time of 12 hours with the photosensitizer. Subsequently, a PDI procedure using a LED device was performed to illuminate the worms treated with the photosensitizers. The worms were observed by optical microscopy until 48 hours after the PDI to verify the changes in motility, the presence of eggs and larvae and the number of live worms. Curcuminoids tested separately and in combination and two light doses of 30 J/m2 no changes were observed in the life cycle of the worm at concentrations of 2 mM and 1 mM. However, in treatment with Photogem® and a light dose of 100 J/m2 a reduction in motility and reproduction of the worm with 0.2 mg/mL was observed after 6 hours of exposure, in addition to the death of most worms at concentrations of 6, 4, and 2 mg/mL. We suggest, therefore, that photodynamic inactivation with Photogem® may present an anthelmintic effect against C. elegans, but there is a need for studies on helminths with parasitic activity.

[Efficacy evaluation of epsiprantel (Cestex) against Echinococcus mutilocularis in dogs and cats].

PubMed

Eckert, J; Thompson, R C; Bucklar, H; Bilger, B; Deplazes, P

2001-01-01

Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.

Impacts of chipping on surrogates for the longhorned beetle Anoplophora glabripennis (Coleoptera: Cerambycidae) in logs.

PubMed

Wang, B; Mastro, V C; McLane, W H

2000-12-01

As part of the eradication program for recent introductions of the longhorned beetle Anoplophora glabripennis (Motschulsky) in the United States, wood from infested trees is chipped and incinerated. Two tests were conducted to evaluate the efficiency of chipping wood from infested trees on the survival of the beetle. In the first test, plastic worms were used as surrogates for larvae of the beetle. Plastic worms of different sizes were placed in holes drilled in logs of sugar maple, Acer saccharum Marsh. In a second test, in addition to plastic worms, we used different instars and pupae of gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae); larvae of the beetle Phyllophaga annina Lewis (Coleoptera: Scarabaeidae); and larvae of an unidentified weevil (Coleoptera: Curculionidae). Although chipping did not result in an obvious damage to all plastic worms, it did kill all larvae and pupae of insects placed in holes of maple logs. The overall recovery rate (percent recovered) for the plastic worms was 96% in the first (1997) test, and 71 and 98% for 10 and 40 mm long plastic worms in the second (1998) test, respectively. Logistic regression analysis of the data from the first experiment indicates that larger worms receive more severe damage. Size of logs did not have a significant effect on the level of damage received by plastic worms. All recovered insects were severely damaged after chipping logs and we could not determine recovery rates. Results of the two tests indicate that chipping wood from infested trees without incineration of the resulting chips provides a highly effective method for destroying wood inhabiting insect pests such as A. glabripennis. The elimination of incineration saves considerable resources while effectively eliminating risks associated with movements of wood containing living wood-boring insects.

Operation of an aquatic worm reactor suitable for sludge reduction at large scale.

PubMed

Hendrickx, Tim L G; Elissen, Hellen H J; Temmink, Hardy; Buisman, Cees J N

2011-10-15

Treatment of domestic waste water results in the production of waste sludge, which requires costly further processing. A biological method to reduce the amount of waste sludge and its volume is treatment in an aquatic worm reactor. The potential of such a worm reactor with the oligochaete Lumbriculus variegatus has been shown at small scale. For scaling up purposes, a new configuration of the reactor was designed, in which the worms were positioned horizontally in the carrier material. This was tested in a continuous experiment of 8 weeks where it treated all the waste sludge from a lab-scale activated sludge process. The results showed a higher worm growth rate compared to previous experiments with the old configuration, whilst nutrient release was similar. The new configuration has a low footprint and allows for easy aeration and faeces collection, thereby making it suitable for full scale application. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dietary and microbiome factors determine longevity in Caenorhabditis elegans

PubMed Central

Sánchez-Blanco, Adolfo; Rodríguez-Matellán, Alberto; González-Paramás, Ana; González-Manzano, Susana; Kim, Stuart K.; Mollinedo, Faustino

2016-01-01

Diet composition affects organismal health. Nutrient uptake depends on the microbiome. Caenorhabditis elegans fed a Bacillus subtilis diet live longer than those fed the standard Escherichia coli diet. Here we report that this longevity difference is primarily caused by dietary coQ, an antioxidant synthesized by E. coli but not by B. subtilis. CoQ-supplemented E. coli fed worms have a lower oxidation state yet live shorter than coQ-less B. subtilis fed worms. We showed that mutations affecting longevity for E. coli fed worms do not always lead to similar effects when worms are fed B. subtilis. We propose that coQ supplementation by the E. coli diet alters the worm cellular REDOX homeostasis, thus decreasing longevity. Our results highlight the importance of microbiome factors in longevity, argue that antioxidant supplementation can be detrimental, and suggest that the C. elegans standard E. coli diet can alter the effect of signaling pathways on longevity. PMID:27510225

Selective primary health care: strategies for control of disease in the developing world. XII. Ascariasis and trichuriasis.

PubMed

Arfaa, F

1984-01-01

Ascariasis and trichuriasis are the most prevalent and widespread intestinal helminthiases. Transmission of disease occurs by ingestion or inhalation of Ascaris and Trichuris eggs embryonated in the soil. During the migration of Ascaris to the lungs, pneumonic symptoms may develop. The intestinal stage of the parasite can cause severe symptoms and complications when the worm burden is high. High numbers of Trichuris may cause diarrhea. The poor standard of hygiene, the biology of the parasite (which is such that a high number of very resistant eggs are produced), and the habits of the host (such as the use of night soil) are factors causing a high prevalence of infection in many countries in Asia, Africa, South America, and Europe. The mechanism of the transmission of Ascaris varies in different communities. The peak of infection is among children aged four to 14 years. Worm burden is normally low, and only a small segment of the population harbors a high proportion of the worms present in a community. Control of infections due to Ascaris and Trichuris is feasible by a combination of mass chemotherapy with the effective drugs now available, safe disposal of excreta, destruction of the eggs, and health education.

Comparative Evaluation of Anthelmintic Activity of Edible and Ornamental Pomegranate Ethanolic Extracts against Schistosoma mansoni

PubMed Central

Badary, Dalia M.; Sayed, Hesham M. B.; Bayoumi, Soad A. H.; Khalifa, Azza A.; El-Moghazy, Ahmed M.

2016-01-01

Due to the development of praziquantel (PZQ) schistosomes resistant strains, the discovery of new antischistosomal agents is of high priority in research. This work reported the in vitro and in vivo effects of the edible and ornamental pomegranate extracts against Schistosoma mansoni. Leaves and stem bark ethanolic extracts of both dried pomegranates were prepared at 100, 300, and 500 μg/mL for in vitro and 600 and 800 mg/kg for in vivo. Adult worms Schistosoma mansoni in RPMI-1640 medium for in vitro and S. mansoni infected mice for in vivo tests were obtained from Theodor Bilharz Research Institute, Cairo, Egypt. In vitro activity was manifested by significant coupled worms separation, reduction of motor activity, lethality, and ultrastructural tegumental alterations in adult worms. In vivo activity was manifested revealed by significant reduction of hepatic granulomas number and diameter, decreased number of bilharzial eggs in liver tissues, lowered liver inflammatory infiltration, decreased hepatic fibrosis, and inducible nitric oxide synthase (iNOS) expression. Ethanolic stem bark extract of edible pomegranate exhibited highest antischistosomal activities both in vitro and in vivo. Therefore, pomegranate showed a good potential to be used as a promising new candidate for the development of new schistosomicidal agents. PMID:27990425

Path-integral theory of an axially confined worm-like chain

NASA Astrophysics Data System (ADS)

Smith, D. A.

2001-06-01

A path-integral formulation is developed for the thermodynamic properties of a worm-like chain moving on a surface and laterally confined by a harmonic potential. The free energy of the chain is calculated as a function of its length and boundary conditions at each end. Distribution functions for chain displacements can be constructed by utilizing the Markov property as a function of displacement φ(s) and its derivative dφ(s)/ds along the path. These quantities are also calculated in the presence of pinning sites which impose fixed positive or negative displacements, foreshadowing their application to a model for the regulation of striated muscle.

Possible application of a nematophagous fungus as a biological control agent of parasitic nematodes on commercial sheep farms in South Africa.

PubMed

Faedo, M; Krecek, R C

2002-03-01

Biological control of parasitic nematodes of livestock is currently under development and represents another tool that may be integrated into helminth parasite control strategies. This paper presents a brief introduction to commercial sheep farming in South Africa and currently available nematode parasite control methods. These include the FAMACHA clinical assay, strategies of pasture management, dilution of resistant worm species by introduction of susceptible worms, breed resistant sheep and nutritional supplementation. The purpose of this paper is to outline the principles of biological control using nematophagous fungi and how it may be applied on sheep farms in South Africa.

A new worm infiltrating the human cornea: A report of three cases.

PubMed

McBurney-Lin, Shan; Khorram, David; Gee, Stephen; Hoberg, Eric P; Klassen-Fischer, Mary K; Neafie, Ronald C

2018-03-01

To characterize a new species of parasitic nematode that triggers uveitis. Three previously healthy, relatively young people each contracted a corneal stromal nematode that, upon surgical removal and examination, did not match any known nematodes. Clinical ocular findings included corneal opacification, visible corneal worms, conjunctival injection, and uveitis. The three cases presented here represent a previously undescribed parasitic infection of the cornea by an unidentified nematode. These findings may represent a previously unrecognized zoonotic infection from wildlife sources and potentially a newly documented nematode requiring description. Future clinical findings regarding this newly described nematode are needed to further develop our understanding of the disease.

Exploring the Wild World of Wiggly Worms

ERIC Educational Resources Information Center

Dominguez, Lynn; McDonald, James; Kalajian, Katie; Stafford, Kristine

2013-01-01

Young children are naturally curious and constantly exploring the world around them. Combining this curiosity with the outdoors and nature for science skill development has many advantages for young learners. As children develop an enhanced understanding of the natural world, they are also developing explanations of how things work. Allowing…

Removal of Thelazia callipaeda from the subconjunctival space.

PubMed

Yagi, T; Sasoh, M; Kawano, T; Ito, K; Uji, Y; Ando, K

2007-01-01

To report the finding of Thelazia callipaeda within the human subconjunctival space. An 81-year-old man with a history of traumatic conjunctival laceration that occurred 2 years previously had white worms in the subconjunctival space of his right eye. Five worms were removed from the subconjunctival space via a local peritomy, since there was no conjunctival laceration noted during the examination. These worms were identified as T callipaeda. T callipaeda cannot dig holes in the ocular wall due to the lack of hooks or sharp spines within the mouth. Therefore, the authors speculate that these worms entered the subconjunctival space through a conjunctival laceration that had occurred 2 years previously.

Orthotic arm joint. [for use in mechanical arms

NASA Technical Reports Server (NTRS)

Dane, D. H. (Inventor)

1974-01-01

An improved orthopedic (orthotic) arm joint that can be used in various joint of mechanical arms is described. The arm joints includes a worm, which is coupled to an electric motor for rotating a worm gear carried within a rotatable housing. The worm gear is supported on a thrust bearing and the rotatable housing is supported on a radial thrust bearing. A bolt extends through the housing, bearings, and worm gear for securing the device together. A potentiometer extends through the bolt, and is coupled to the rotatable housing for rotating therewith, so as to produce an electrical signal indicating the angular position of the rotatable housing.

Dracunculiasis (guinea worm disease).

PubMed

Greenaway, Chris

2004-02-17

Dracunculiasis (guinea worm disease) is a parasitic disease that is limited to remote, rural villages in 13 sub-Saharan African countries that do not have access to safe drinking water. It is one the next diseases targeted for eradication by the World Health Organization. Guinea worm disease is transmitted by drinking water containing copepods (water fleas) that are infected with Dracunculiasis medinensis larvae. One year after human ingestion of infected water a female adult worm emerges, typically from a lower extremity, producing painful ulcers that can impair mobility for up to several weeks. This disease occurs annually when agricultural activities are at their peak. Large proportions of economically productive individuals of a village are usually affected simultaneously, resulting in decreased agricultural productivity and economic hardship. Eradication of guinea worm disease depends on prevention, as there is no effective treatment or vaccine. Since 1986, there has been a 98% reduction in guinea worm disease worldwide, achieved primarily through community-based programs. These programs have educated local populations on how to filter drinking water to remove the parasite and how to prevent those with ulcers from infecting drinking-water sources. Complete eradication will require sustained high-level political, financial and community support.

Guinea worm infection in northern Nigeria: reflections on a disease approaching eradication.

PubMed

Greenwood, Brian; Greenwood, Alice; Bradley, Andrew

2017-05-01

Global eradication of the guinea worm (Dracunculus medinensis) is near, although perhaps delayed a little by the discovery of a transmission cycle in dogs. It is therefore an appropriate time to reflect on the severe impact of this infection on the life of the communities where it was endemic prior to the start of the global eradication programme in 1981. From 1971 to 1974, we conducted a series of unpublished studies on guinea worm in a group of villages in Katsina State, northern Nigeria, where the infection was highly endemic. These studies demonstrated the high rate of infection in affected communities, the frequent recurrence of the infection in some subjects and the long-standing disability that remained in some infected individuals. Immunological studies showed a high level of immediate hypersensitivity to adult worm and larval antigens but a downregulation of Th1-type T-cell responses to worm antigens. Freeing communities such as those described in this article from the scourge of guinea worm infection for good will be an important public health triumph. © 2017 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Is Gnathostoma turgidum an annual parasite of opossums? Drastic seasonal changes of infection in Didelphis virginiana in Mexico.

PubMed

Nawa, Yukifumi; de la Cruz-Otero, María del Carmen; Zazueta-Ramos, Magda Luz; Bojórquez-Contreras, Angel; Sicairos-Félix, Josefina; Campista-León, Samuel; Torres-Montoya, Edith Hilario; Sánchez-Gonzalest, Sergio; Guzmán-Loreto, Roberto; Delgado-Vargas, Francisco; Díaz-Camacho, Sylvia Páz

2009-08-01

Gnathostoma turgidum is a nematode that parasitizes the stomach of opossums, Didelphis virginiana. Despite its wide distribution in the Americas, its natural life cycle is poorly understood. Recently, we found an endemic area for G. turgidum infection in Sinaloa, Mexico (Diaz-Camacho et al., 2009). Based on sporadic surveys for several years, the prevalence was apparently high in summer and extremely low in winter. To confirm that this is really a seasonal variance, we conducted a longitudinal survey on G. turgidum infection in opossums from November 2007 to November 2008. The results showed amazing seasonal changes in the prevalence, with synchronized migration and maturation of worms in opossums. Between February and March, many juvenile worms, with occasional AL3, were found in the liver, but no worms were found in the stomach. Mature adult worms began to appear in the stomach around April and rapidly increased in number toward July, when all worms resided in the stomach. Then, the worms disappeared almost completely by November. These results suggest that G. turgidum is an annual parasite of the opossum, D. virginiana, in Mexico.

In vitro schistosomicidal effects of aqueous and dichloromethane fractions from leaves and stems of Piper species and the isolation of an active amide from P. amalago L. (Piperaceae).

PubMed

Carrara, V S; Vieira, S C H; de Paula, R G; Rodrigues, V; Magalhães, L G; Cortez, D A G; Da Silva Filho, A A

2014-09-01

Dichloromethane and aqueous fractions from leaves and stems of Piper arboreum Aubl., P. aduncum L., P. amalago L., P. crassinervium H.B. & K., P. diospyrifolium Kunth, P. hispidum Sw. and P. xylosteoides (Kunth) Steud. were tested against adult worms of Schistosoma mansoni. The in vitro activity was evaluated in terms of mortality, number of separated worms and number of worms with reduced motor activity. Most dichloromethane fractions from all Piper species showed moderate schistosomicidal activity, but aqueous fractions were not active. The dichloromethane fraction of P. amalago leaves (at 100 μg/ml) showed the highest activity, resulting in worm mortality, the separation of worm pairs and reduced motor activity. Chromatographic fractionation of the dichloromethane fraction of P. amalago leaves led to the isolation of its major compound, which was also tested against adults of S. mansoni. The isolated piperamide N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine, at 100 μ m, resulted in the mortality of all adult worms after 24 h of incubation. The findings suggest that species of Piper are potential sources of schistosomicidal compounds.

Associations among habitat characteristics and meningeal worm prevalence in eastern South Dakota, USA

USGS Publications Warehouse

Jacques, Christopher N.; Jenks, Jonathan A.; Klaver, Robert W.; Dubay, Shelli A.

2017-01-01

Few studies have evaluated how wetland and forest characteristics influence the prevalence of meningeal worm (Parelaphostrongylus tenuis) infection of deer throughout the grassland biome of central North America. We used previously collected, county-level prevalence data to evaluate associations between habitat characteristics and probability of meningeal worm infection in white-tailed deer (Odocoileus virginianus) across eastern South Dakota, US. The highest-ranked binomial regression model for detecting probability of meningeal worm infection was spring temperature + summer precipitation + percent wetland; weight of evidence (wi=0.71) favored this model over alternative models, though predictive capability was low (Receiver operating characteristic=0.62). Probability of meningeal worm infection increased by 1.3- and 1.6-fold for each 1-cm and 1-C increase in summer precipitation and spring temperature, respectively. Similarly, probability of infection increased 1.2-fold for each 1% increase in wetland habitat. Our findings highlight the importance of wetland habitat in predicting meningeal worm infection across eastern South Dakota. Future research is warranted to evaluate the relationships between climatic conditions (e.g., drought, wet cycles) and deer habitat selection in maintaining P. tenuis along the western boundary of the parasite.

Petri Net and Probabilistic Model Checking Based Approach for the Modelling, Simulation and Verification of Internet Worm Propagation

PubMed Central

Razzaq, Misbah; Ahmad, Jamil

2015-01-01

Internet worms are analogous to biological viruses since they can infect a host and have the ability to propagate through a chosen medium. To prevent the spread of a worm or to grasp how to regulate a prevailing worm, compartmental models are commonly used as a means to examine and understand the patterns and mechanisms of a worm spread. However, one of the greatest challenge is to produce methods to verify and validate the behavioural properties of a compartmental model. This is why in this study we suggest a framework based on Petri Nets and Model Checking through which we can meticulously examine and validate these models. We investigate Susceptible-Exposed-Infectious-Recovered (SEIR) model and propose a new model Susceptible-Exposed-Infectious-Recovered-Delayed-Quarantined (Susceptible/Recovered) (SEIDQR(S/I)) along with hybrid quarantine strategy, which is then constructed and analysed using Stochastic Petri Nets and Continuous Time Markov Chain. The analysis shows that the hybrid quarantine strategy is extremely effective in reducing the risk of propagating the worm. Through Model Checking, we gained insight into the functionality of compartmental models. Model Checking results validate simulation ones well, which fully support the proposed framework. PMID:26713449

Petri Net and Probabilistic Model Checking Based Approach for the Modelling, Simulation and Verification of Internet Worm Propagation.

PubMed

Razzaq, Misbah; Ahmad, Jamil

2015-01-01

Internet worms are analogous to biological viruses since they can infect a host and have the ability to propagate through a chosen medium. To prevent the spread of a worm or to grasp how to regulate a prevailing worm, compartmental models are commonly used as a means to examine and understand the patterns and mechanisms of a worm spread. However, one of the greatest challenge is to produce methods to verify and validate the behavioural properties of a compartmental model. This is why in this study we suggest a framework based on Petri Nets and Model Checking through which we can meticulously examine and validate these models. We investigate Susceptible-Exposed-Infectious-Recovered (SEIR) model and propose a new model Susceptible-Exposed-Infectious-Recovered-Delayed-Quarantined (Susceptible/Recovered) (SEIDQR(S/I)) along with hybrid quarantine strategy, which is then constructed and analysed using Stochastic Petri Nets and Continuous Time Markov Chain. The analysis shows that the hybrid quarantine strategy is extremely effective in reducing the risk of propagating the worm. Through Model Checking, we gained insight into the functionality of compartmental models. Model Checking results validate simulation ones well, which fully support the proposed framework.

Polycyclic aromatic hydrocarbons in Saccoglossus kowalewskyi (Agassiz)

NASA Astrophysics Data System (ADS)

Carey, D. A.; Farrington, J. W.

1989-08-01

Hydrocarbon extracts were analyzed from Saccoglossus kowalewskyi, a deposit-feeding enteropneust worm, and from surface sediments from Cape Cod, MA. Worms were held in experimental aquaria in sieved sediments and flowing seawater for four months and then fed sediments mixed with creosote, lampblack or clean sediment for two weeks as analogues of sediments containing degraded oil and pyrogenic compounds. Worms from all treatments contained polyaromatic hydrocarbons (PAHs) in amounts and composition that indicate that the worms were contaminated with weathered No. 2 fuel oil before our experimental treatment and that the contamination persisted for four months in clean conditions. The contamination was not detected in the clean sediments used in the experiment. The worms accumulated steroid transformation products in greater abundance than the odd chain n-alkanes that dominated the sediment extractions. This may indicate selective assimilation of algal detritus and microbial products over salt marsh detritus. Worms, actively feeding during the experiment, contained 1-3 × 10 -6 g g -1 dry weight of unknown brominated compounds which were not detected in the sediments. These compounds are similar to bromopyrroles found elsewhere in enteropneusts, polychaetes and bacteria and may cause substantial interference in analyses for some industrial pollutants.

Inference of pain stimulus level from stereotypical behavioral response of C.elegans allows quantification of effects of anesthesia and mutation

NASA Astrophysics Data System (ADS)

Leung, Kawai; Mohammadi, Aylia; Ryu, William; Nemenman, Ilya

In animals, we must infer the pain level from experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. To establish C.elegans as a model for pain research, we propose for the first time a quantitative model that allows inference of a thermal nociceptive stimulus level from the behavior of an individual worm. We apply controlled levels of pain by locally heating worms with an infrared laser and capturing the subsequent behavior. We discover that the behavioral response is a product of stereotypical behavior and a nonlinear function of the strength of stimulus. The same stereotypical behavior is observed in normal, anesthetized and mutated worms. From this result we build a Bayesian model to infer the strength of laser stimulus from the behavior. This model allows us to measure the efficacy of anaesthetization and mutation by comparing the inferred strength of stimulus. Based on the measured nociceptive escape of over 200 worms, our model is able to significantly differentiate normal, anaesthetized and mutated worms with 40 worm samples. This work was partially supported by NSF Grant No. IOS/1208126 and HFSP Grant No. RGY0084/.

Worm Disease Profile of Primary School Children

NASA Astrophysics Data System (ADS)

Hartati; Destriani; Victoria, A. R.

2018-01-01

The result of an elementary study of relations between disease symptoms and signs with the wormy occurrence child at Elementary School in Ilir Barat II Subdistrict of Palembang in concerned in this research amount to 200 people from the population of 4200 people of a child in elementary school. The result indicates that the child roommates infested worm marked with a few symptoms like passion eat to Decrease the puking pain in the home of stomach after eating, diarrhea, defecate with the mucus and bleed the purities at the anus before controlled from some worm type of there no difference having a meaning between child roommates worm infested with the child roommates do not infest worm (P > 0.05). Symptom vomit got more amount by having a meaning a child by infested is Trichuris (RO > 2.669, P < 0/005). The result of infested Tricuris generate the more amount of symptoms lust to eat to Decrease by having a meaning of Compared to the which do not infest Trichuris (RO = 3.772; CI 95% = 1.214 to 11.726; P = 0.016) symptoms lust to eat to Decrease and more amount diarrhea got at Infest oxyuris with the special sign of purities at nighttime anus (RO = 0.557; 85% CI = 0.166 to 2.168). The risk of the happening of unfavorable nutrition According to BB / U and Also TB / U growing niche to more amount (having a meaning) at child roommates worm infested by a child Compared to the which do not infest worm.

The effects of Myxobolus cerebralis, myxospore dose on triactinomyxon production and biology of Tubifex tubifex from two geographic regions

USGS Publications Warehouse

Stevens, Richard; Kerans, B.L.; Lemmon, J. C.; Rasmussen, Charlotte

2001-01-01

The aquatic oligochaete Tubifex tubifex is an obligate host of Myxobolus cerebralis, the causative agent of salmonid whirling disease. Tubifex tubifex can become infected by ingesting myxospores ofM. cerebralis that have been released into sediments upon death and decomposition of infected salmonids. Infected worms release triactinomyxons into the water column that then infect salmonids. How the dose of myxospores ingested by T. tubifex influences parasite proliferation and the worm host are not well understood. Using replicated laboratory experiments, we examined how differing doses of myxospores (50, 500, 1,000 per worm) influenced triactinomyxon production and biomass, abundance, and individual weight of 2 geographically distinct populations of T. tubifex. Worm populations produced differing numbers of triactinomyxons, but, within a population, the production did not differ among myxospore doses. At the lowest myxospore dose, 1 worm population produced 45 times more triactinomyxons than myxospores received, whereas the other produced only 6 times more triactinomyxons than myxospores. Moreover, total T. tubifex biomass, abundance, and individual weight were lower among worms receiving myxospores than in myxospore-free controls. Thus, T. tubifex populations differ in ability to support the replication of M. cerebralis, and infection has measurable consequences on fitness of the worm host. These results suggest that variability in whirling disease severity observed in wild salmonid populations may partially be attributed to differences in T. tubifex populations.

Heartworm of swans and geese

USGS Publications Warehouse

Cole, Rebecca A.

1999-01-01

Heartworm in swans and geese is caused by a filarial nematode or a roundworm of the superfamily Filarioidea which is transmitted to the bird by a biting louse. The nematode and the louse both are parasites. Sarconema eurycerca is the only one of several species of microfilaria or the first stage juvenile of the parasite found in the circulating blood of waterfowl that is known to be pathogenic or cause clinical disease.

Cost-effective antigen testing for delimitation, monitoring and evaluation in bancroftian filariasis.

PubMed

Das, L K; Pani, S P; Vanamail, P; Vijayalakshmi, G; Debritto, L J

2012-01-31

This study was focussed on identifying a cost-effective method for delimitation, monitoring and evaluation in bancroftian filariasis. Finger prick blood samples were collected between 20.00 and 23.00 hours for the detection of microfilariae (mf) from the available population in a village which was endemic for lymphatic filariasis. Simultaneously, from each individual, four spots of 25-μl blood samples were collected on Whatman number 3 filter paper and air dried. Dried filter paper spots were pooled in quantities of 1, 5, 10, 15, 20 and 25 on unknown and simulated mf and antigen prevalence. Pooled samples were assayed for circulating filarial antigen (CFA) using TropBIO Og4C3 ELISA kits. The community mf and CFA rates were 3.4% and 25.9%, respectively. The pool sizes of 20 and 25 showed CFA positivity in all the above categories tested. The results of the pooled blood spot samples suggest that, in areas with mf and CFA prevalence rates between 1 and 10%, pools of 20 or 25 could be considered as the ideal pool size for the detection of filarial infection in the community. CFA prevalence at the level of 5-6% following desirable rounds of mass drug administration (MDA) indicates that the community mf prevalence is likely to be at the 1% level.

Novel Insights into the Transcriptome of Dirofilaria immitis

PubMed Central

Zhang, Zhihe; Hou, Rong; Wu, Xuhang; Yang, Deying; Zhang, Runhui; Zheng, Wanpeng; Nie, Huaming; Xie, Yue; Yan, Ning; Yang, Zhi; Wang, Chengdong; Luo, Li; Liu, Li; Gu, Xiaobin; Wang, Shuxian; Peng, Xuerong; Yang, Guangyou

2012-01-01

Background The heartworm Dirofilaria immitis is the causal agent of cardiopulmonary dirofilariosis in dogs and cats, and also infects a wide range of wild mammals as well as humans. One bottleneck for the design of fundamentally new intervention and management strategies against D. immitis may be the currently limited knowledge of fundamental molecular aspects of D. immitis. Methodology/Principal Findings A next-generation sequencing platform combining computational approaches was employed to assess a global view of the heartworm transcriptome. A total of 20,810 unigenes (mean length  = 1,270 bp) were assembled from 22.3 million clean reads. From these, 15,698 coding sequences (CDS) were inferred, and about 85% of the unigenes had orthologs/homologs in public databases. Comparative transcriptomic study uncovered 4,157 filarial-specific genes as well as 3,795 genes potentially involved in filarial-Wolbachia symbiosis. In addition, the potential intestine transcriptome of D. immitis (1,101 genes) was mined for the first time, which might help to discover ‘hidden antigens’. Conclusions/Significance This study provides novel insights into the transcriptome of D. immitis and sheds light on its molecular processes and survival mechanisms. Furthermore, it provides a platform to discover new vaccine candidates and potential targets for new drugs against dirofilariosis. PMID:22911833

Lymphatic filariasis: patients and the global elimination programme.

PubMed

Mackenzie, C D; Lazarus, W M; Mwakitalu, M E; Mwingira, U; Malecela, M N

2009-10-01

The defining images of lymphatic filariasis are the horrendous disfigurements of lymphoedema, elephantiasis and hydrocele. These clinical presentations, although obviously important and life changing, are not, however, the only outcomes of this wide-spread filarial infection. The other effects of the disease range from severe, acute but short-term bouts of sickness to psychological impairment, poverty and family hardship. It is important to support cases of the disease through all means available, such as reparative hydrocelectomy, hygiene training and facilitation, and the provision of adequate chemotherapy. Although only a minority of the residents in any endemic community is affected with the severe clinical manifestations of this parasitic infection, these cases are central to, and important advocates for, the current global effort to eliminate the infection through mass drug administrations (MDA). Their clinical improvement acts as an important catalyst for the general population and encourages high compliance in the MDA. This communication discusses the central role that filariasis patients have played in the Tanzania Lymphatic Filariasis Elimination Programme to date, and covers some of the clinical successes achieved in the past 10 years. The abolition of the clinical manifestations of filarial infection remains the ultimate goal of the Global Programme to Eliminate Lymphatic Filariasis, and maintaining a focus on the affected individuals and their clinical condition is vital to that programme's overall success.

Mansonella ozzardi mitogenome and pseudogene characterisation provides new perspectives on filarial parasite systematics and CO-1 barcoding.

PubMed

Crainey, James Lee; Marín, Michel Abanto; Silva, Túllio Romão Ribeiro da; de Medeiros, Jansen Fernandes; Pessoa, Felipe Arley Costa; Santos, Yago Vinícius; Vicente, Ana Carolina Paulo; Luz, Sérgio Luiz Bessa

2018-04-18

Despite the broad distribution of M. ozzardi in Latin America and the Caribbean, there is still very little DNA sequence data available to study this neglected parasite's epidemiology. Mitochondrial DNA (mtDNA) sequences, especially the cytochrome oxidase (CO1) gene's barcoding region, have been targeted successfully for filarial diagnostics and for epidemiological, ecological and evolutionary studies. MtDNA-based studies can, however, be compromised by unrecognised mitochondrial pseudogenes, such as Numts. Here, we have used shot-gun Illumina-HiSeq sequencing to recover the first complete Mansonella genus mitogenome and to identify several mitochondrial-origin pseudogenes. Mitogenome phylogenetic analysis placed M. ozzardi in the Onchocercidae "ONC5" clade and suggested that Mansonella parasites are more closely related to Wuchereria and Brugia genera parasites than they are to Loa genus parasites. DNA sequence alignments, BLAST searches and conceptual translations have been used to compliment phylogenetic analysis showing that M. ozzardi from the Amazon and Caribbean regions are near-identical and that previously reported Peruvian M. ozzardi CO1 reference sequences are probably of pseudogene origin. In addition to adding a much-needed resource to the Mansonella genus's molecular tool-kit and providing evidence that some M. ozzardi CO1 sequence deposits are pseudogenes, our results suggest that all Neotropical M. ozzardi parasites are closely related.

Mercury toxicity in the aquatic oligochaete Sparganophilus pearsei: I. Variation in resistance among populations.

PubMed

Vidal, D E; Horne, A J

2003-08-01

Mercury contamination has become a problem in many San Francisco Bay Area watersheds due to its elevated presence in sediments and aquatic organisms. The present study used laboratory lethal toxicity (LC50) tests to examine the mercury tolerance of aquatic oligochaete worms, Sparganophilus pearsei, from contaminated and uncontaminated areas. The oligochaetes were collected in the following fresh water reservoirs: Sandy Wool (reference area), San Pablo, Lake Anza, Lake Herman, and Guadalupe. These last four reservoirs were contaminated with levels of mercury that ranged from 1.5 to 2 mg/kg (wet weight). Mercury concentrations in sediment and tissue from Sandy Wool were below detection limits and worms from this site were the least tolerant of mercury in laboratory exposures (LC50 = 0.22 mg/L). Worms from the other, more contaminated, reservoirs contained elevated tissue mercury concentrations and were more tolerant in laboratory tests (LC50 = 1.48-2.19 mg/L). The present study demonstrates that different populations of the aquatic oligochaete S. pearsei have developed different tolerances to mercury depending on their previous history of exposure to mercury contamination.

Proteomic analysis of the excretory/secretory products and antigenic proteins of Echinococcus granulosus adult worms from infected dogs.

PubMed

Wang, Ying; Xiao, Di; Shen, Yujuan; Han, Xiuming; Zhao, Fei; Li, Xiaohong; Wu, Weiping; Zhou, Hejun; Zhang, Jianzhong; Cao, Jianping

2015-05-21

Cystic echinococcosis, which is caused by Echinococcus granulosus, is one of the most widespread zoonotic helminth diseases that affects humans and livestock. Dogs, which harbor adult worms in their small intestines, are a pivotal source of E. granulosus infection in humans and domestic animals. Therefore, novel molecular approaches for the prevention and diagnosis of this parasite infection in dogs need to be developed. In this study, we performed proteomic analysis to identify excretory/secretory products (ES) and antigenic proteins of E. granulosus adult worms using two-dimensional electrophoresis, tandem matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF/TOF), and Western blotting of sera from infected dogs. This study identified 33 ES product spots corresponding to 9 different proteins and 21 antigenic protein spots corresponding to 13 different proteins. Six antigenic proteins were identified for the first time. The present study extended the existing proteomic data of E. granulosus and provides further information regarding host-parasite interactions and survival mechanisms. The results of this study contribute to vaccination and immunodiagnoses for E. granulosus infections.

Role of CREB in CML

DTIC Science & Technology

2007-02-01

antisense RNA for suppressing gene expression in nematode worms (Caenorhabditis elegans) 2. This was followed by the introduction of dsRNA into worms...When single-stranded antisense RNA and double stranded RNA was introduced into worms, they found that dsRNA was more effective than either strand...RISC ( RNA -induced silencing complex), which contains helicase activity that unwinds the two strands 3 of RNA molecules, allowing the antisense

Worms Eat My Garbage. How To Set Up and Maintain a Worm Composting System. First Edition.

ERIC Educational Resources Information Center

Appelhof, Mary

This book is a resource for parents and teachers who want to teach about recycling and composting by setting up and maintaining a worm composting system. It is designed to be a detailed yet simple manual of vermicomposting. The manual covers the basics of vermicomposting and answers such questions as where to store a composting container, what…

Effects of simulated microgravity on gene expression and biological phenotypes of a single generation Caenorhabditis elegans cultured on 2 different media

NASA Astrophysics Data System (ADS)

Tee, Ling Fei; Neoh, Hui-min; Then, Sue Mian; Murad, Nor Azian; Asillam, Mohd Fairos; Hashim, Mohd Helmy; Nathan, Sheila; Jamal, Rahman

2017-11-01

Studies of multigenerational Caenorhabditis elegans exposed to long-term spaceflight have revealed expression changes of genes involved in longevity, DNA repair, and locomotion. However, results from spaceflight experiments are difficult to reproduce as space missions are costly and opportunities are rather limited for researchers. In addition, multigenerational cultures of C. elegans used in previous studies contribute to mixture of gene expression profiles from both larvae and adult worms, which were recently reported to be different. Usage of different culture media during microgravity simulation experiments might also give rise to differences in the gene expression and biological phenotypes of the worms. In this study, we investigated the effects of simulated microgravity on the gene expression and biological phenotype profiles of a single generation of C. elegans worms cultured on 2 different culture media. A desktop Random Positioning Machine (RPM) was used to simulate microgravity on the worms for approximately 52 to 54 h. Gene expression profile was analysed using the Affymetrix GeneChip® C. elegans 1.0 ST Array. Only one gene (R01H2.2) was found to be downregulated in nematode growth medium (NGM)-cultured worms exposed to simulated microgravity. On the other hand, eight genes were differentially expressed for C. elegans Maintenance Medium (CeMM)-cultured worms in microgravity; six were upregulated, while two were downregulated. Five of the upregulated genes (C07E3.15, C34H3.21, C32D5.16, F35H8.9 and C34F11.17) encode non-coding RNAs. In terms of biological phenotype, we observed that microgravity-simulated worms experienced minimal changes in terms of lifespan, locomotion and reproductive capabilities in comparison with the ground controls. Taking it all together, simulated microgravity on a single generation of C. elegans did not confer major changes to their gene expression and biological phenotype. Nevertheless, exposure of the worms to microgravity lead to higher expression of non-coding RNA genes, which may play an epigenetic role in the worms during longer terms of microgravity exposure.

The Dr-nanos gene is essential for germ cell specification in the planarian Dugesia ryukyuensis.

PubMed

Nakagawa, Haruka; Ishizu, Hirotsugu; Chinone, Ayako; Kobayashi, Kazuya; Matsumoto, Midori

2012-01-01

Homologs of nanos are required for the formation and maintenance of germline stem cell (GSC) systems and for gametogenesis in many metazoans. Planarians can change their reproductive mode seasonally, alternating between asexual and sexual reproduction; they develop and maintain their somatic stem cells (SSCs) and GCSs from pluripotent stem cells known as neoblasts. We isolated a nanos homolog, Dr-nanos, from the expressed sequence tags (ESTs) of the sexualized form of Dugesia ryukyuensis. We examined the expression of Dr-nanos in asexual and sexualized planarians by in situ hybridization and analyzed its function using RNA interference (RNAi) together with a planarian sexualization assay. A nanos homolog, Dr-nanos, was identified in the planarian D. ryukyuensis. Dr-nanos expression was observed in the ovarian primordial cells of the asexual worms. This expression increased in proportion to sexualization and was localized in the early germline cells of the ovaries and testes. In X-ray-irradiated worms, the expression of Dr-nanos decreased to a large extent, indicating that Dr-nanos is expressed in some subpopulations of stem cells, especially in GSCs. During the sexualization process, worms in which Dr-nanos was knocked down by RNAi exhibited decreased numbers of oogonia in the ovaries and failed to develop testes, whereas the somatic sexual organs were not affected. We conclude that Dr-nanos is essential for the development of germ cells in the ovaries and testes and may have a function in the early stages of germ cell specification, but not in the development of somatic sexual organs.

Novel Therapeutics for Multiple Sclerosis Designed by Parasitic Worms

PubMed Central

Dixit, Aakanksha; Tanaka, Akane; Greer, Judith M.

2017-01-01

The evolutionary response to endemic infections with parasitic worms (helminth) was the development of a distinct regulatory immune profile arising from the need to encapsulate the helminths while simultaneously repairing tissue damage. According to the old friend’s hypothesis, the diminished exposure to these parasites in the developed world has resulted in a dysregulated immune response that contributes to the increased incidence of immune mediated diseases such as Multiple Sclerosis (MS). Indeed, the global distribution of MS shows an inverse correlation to the prevalence of helminth infection. On this basis, the possibility of treating MS with helminth infection has been explored in animal models and phase 1 and 2 human clinical trials. However, the possibility also exists that the individual immune modulatory molecules secreted by helminth parasites may offer a more defined therapeutic strategy. PMID:29027962

Marine worms (genus Osedax) colonize cow bones

PubMed Central

Jones, William J; Johnson, Shannon B; Rouse, Greg W; Vrijenhoek, Robert C

2007-01-01

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893 m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and some hosted dwarf males in their tubes. Morphological and molecular examinations of these worms confirmed the presence of six Osedax species, out of the eight species presently known from Monterey Bay. The ability of Osedax species to colonize, grow and reproduce on cow bones challenges previous notions that these worms are ‘whale-fall specialists.’ PMID:18077256

Marine worms (genus Osedax) colonize cow bones.

PubMed

Jones, William J; Johnson, Shannon B; Rouse, Greg W; Vrijenhoek, Robert C

2008-02-22

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and some hosted dwarf males in their tubes. Morphological and molecular examinations of these worms confirmed the presence of six Osedax species, out of the eight species presently known from Monterey Bay. The ability of Osedax species to colonize, grow and reproduce on cow bones challenges previous notions that these worms are 'whale-fall specialists.'

Short-Term Effects of the Anti-sea Lice Therapeutant Emamectin Benzoate on Clam Worms (Nereis virens).

PubMed

McBriarty, G J; Kidd, K A; Burridge, L E

2018-05-01

The polychaete Nereis virens occurs commonly in marine sediments, is widely distributed, and is a popular bait species, as well as a potential replacement for wild-caught fish in commercial fish feed preparations. It is being considered as a potential co-extractive species for culture in integrated multi-trophic aquaculture operations. However, it is not known whether pesticides or drugs used to treat sea lice on farmed salmon, such as emamectin benzoate (EB), would adversely affect cultured or wild worms, because these compounds may persist in the environment. To determine the potential effects of EB to N. virens, bioassays were performed wherein worms were exposed in sand for 30 days to a concentration of 400 µg/kg dw (nominal). While no treatment-related mortality occurred, significant decreases in worm mass and marked behavioral changes (lack of burrowing) were observed in EB-treated sand compared with controls. These lab-based observations suggest a potential hazard to worms at sites where EB treatments have occurred.

Worm-like micelles of CTAB and sodium salicylate under turbulent flow.

PubMed

Rodrigues, Roberta K; da Silva, Marcelo A; Sabadini, Edvaldo

2008-12-16

Polymers with high molecular weight and worm-like micelles are drag-reducing agents under turbulent flow. However, in contrast to the polymeric systems, the worm-like micelles do not undergo mechanical degradation due to the turbulence, because their macromolecular structure can be spontaneously restored. This very favorable property, together with their drag-reduction capability, offer the possibility to use such worm-like micelles in heating and cooling systems to recirculate water while expending less energy. The formation, growth, and stability of worm-like micelles formed by cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) were investigated using the self-fluorescence of salicylate ions and the ability of the giant micelles to promote hydrodynamic drag reduction under turbulent flow. The turbulence in solutions of CTAB-Sal was produced within the double-gap cell of a rotational rheometer. Detailed diagrams were obtained for different ratios of Sal and CTAB, which revealed transitions associated with the thermal stability of giant micelles under turbulent flow.

Dracunculiasis (guinea worm disease) in the Bume (Nyangaton) people of South Omo, Ethiopia.

PubMed

Jemaneh, L; Taticheff, S

1993-07-01

A village-to-village search for active dracunculiasis cases was carried out in an endemic area of the Bume (Nyangaton) tribe of South Omo Region, Ethiopia. A total of 21 cases, of which 6, 5, and 10 had pre-emergent, emergent and complicated Guinea worm disease, respectively, were identified. Twenty-two worms, ranging from 1-3 per patient, were removed mainly from the lower limbs; worm appearance seems to be associated more with the right limb. Adults between the ages of 20-30 years are highly affected and infection appears to be sex-related as 14/21 (66.7%) of the cases are females. Water procured from water-holes drug in dry river beds provides an ideal situation for the transmission of dracunculiasis amongst the tribesmen. The knowledge, attitudes and perceptions of the Bume people towards the disease and the public health significance of dracunculiasis are discussed in relation to the current goal of the national and global Guinea worm eradication programme.

Quantifiers more or less quantify online: ERP evidence for partial incremental interpretation

PubMed Central

Urbach, Thomas P.; Kutas, Marta

2010-01-01

Event-related brain potentials were recorded during RSVP reading to test the hypothesis that quantifier expressions are incrementally interpreted fully and immediately. In sentences tapping general knowledge (Farmers grow crops/worms as their primary source of income), Experiment 1 found larger N400s for atypical (worms) than typical objects (crops). Experiment 2 crossed object typicality with non-logical subject-noun phrase quantifiers (most, few). Off-line plausibility ratings exhibited the crossover interaction predicted by full quantifier interpretation: Most farmers grow crops and Few farmers grow worms were rated more plausible than Most farmers grow worms and Few farmers grow crops. Object N400s, although modulated in the expected direction, did not reverse. Experiment 3 replicated these findings with adverbial quantifiers (Farmers often/rarely grow crops/worms). Interpretation of quantifier expressions thus is neither fully immediate nor fully delayed. Furthermore, object atypicality was associated with a frontal slow positivity in few-type/rarely quantifier contexts, suggesting systematic processing differences among quantifier types. PMID:20640044

Changes in characteristics of soluble microbial products and extracellular polymeric substances in membrane bioreactor coupled with worm reactor: relation to membrane fouling.

PubMed

Tian, Yu; Li, Zhipeng; Lu, Yaobin

2012-10-01

The study focused on the membrane fouling mitigation observed in a membrane bioreactor (MBR) coupled with worm reactor system. During the operation time of 100 days, the transmembrane pressure (TMP) in the combined system was maintained less than 5 kPa, while the final TMP in the Control-MBR increased to 30 kPa. The changes in properties of soluble microbial products (SMP) and extracellular polymeric substances (EPS) after worm predation were investigated by means of various analytical techniques. It was found that due to the worm predation, the reduced amount of EPS was far more than the increased amount of SMP leading to a significant decrease of protein-like substances which were dominant in the membrane foulants. Except for the content decrease, worm predation destroyed the functional groups of simple aromatic proteins and tryptophan protein-like substances in EPS, making them have lower tendency attaching to the membrane in the combined system. Copyright © 2012 Elsevier Ltd. All rights reserved.

Antiparasitic activity of menadione (vitamin K3) against Schistosoma mansoni in BABL/c mice.

PubMed

Kapadia, Govind J; Soares, Ingrid A O; Rao, G Subba; Badoco, Fernanda R; Furtado, Ricardo A; Correa, Mariana B; Tavares, Denise C; Cunha, Wilson R; Magalhães, Lizandra G

2017-03-01

Schistosomiasis is one of the neglected tropical diseases affecting nearly quarter of a billion people in economically challenged tropical and subtropical countries of the world. Praziquantel (PZQ) is the only drug currently available to treat this parasitic disease in spite being ineffective against juvenile worms and concerns about developing resistance to treat reinfections. Our earlier in vitro viability studies demonstrated significant antiparasitic activity of menadione (MEN) (vitamin K 3 ) against Schistosoma mansoni adult worms. To gain insight into plausible mechanism of antischistosomal activity of MEN, its effect on superoxide anion levels in adult worms were studied in vitro which showed significant increases in both female and male worms. Further confirmation of the deleterious morphological changes in their teguments and organelles were obtained by ultrastructural analysis. Genotoxic and cytotoxic studies in male Swiss mice indicated that MEN was well tolerated at the oral dose of 500mg/kg using the criteria of MNPCE frequency and PCE/RBC ratio in the bone marrow of infected animals. The in vivo antiparasitic activity of MEN was conducted in female BALB/c mice infected with S. mansoni and significant reductions (P<0.001) in total worm burden were observed at single oral doses of 40 and 400mg/kg (48.57 and 61.90%, respectively). Additionally, MEN significantly reduced (P<0.001) the number of eggs in the liver of infected mice by 53.57 and 58.76%, respectively. Similarly, histological analysis of the livers showed a significant reduction (P<0.001) in the diameter of the granulomas. Since MEN is already in use globally as an over-the-counter drug for a variety of common ailments and a dietary supplement with a safety record in par with similar products when used in recommended doses, the above antiparasitic results which compare reasonably well with PZQ, make a compelling case for considering MEN to treat S. mansoni infection in humans. Copyright © 2016 Elsevier B.V. All rights reserved.

Worms Expelled With the Urine From a Bosniak Cyst III of the Left Kidney.

PubMed

Yang, Jie; Li, Pu; Su, Chuan; Zhang, Jia-Yi; Gu, Min

2016-07-01

An old fishman presented with left lumbago and finding worms in his urine. Type-B ultrasonic inspection and computed tomography scan found a Bosniak cyst III, containing several wire-like elements, in the middle of the left kidney. Expelled worms were confirmed to be Dioctophyma renale. After two courses of albendazole, the man was cured. Copyright © 2016 Elsevier Inc. All rights reserved.

The TRiC/CCT chaperone is implicated in Alzheimer's disease based on patient GWAS and an RNAi screen in Aβ-expressing Caenorhabditis elegans.

PubMed

Khabirova, Eleonora; Moloney, Aileen; Marciniak, Stefan J; Williams, Julie; Lomas, David A; Oliver, Stephen G; Favrin, Giorgio; Sattelle, David B; Crowther, Damian C

2014-01-01

The human Aβ peptide causes progressive paralysis when expressed in the muscles of the nematode worm, C. elegans. We have exploited this model of Aβ toxicity by carrying out an RNAi screen to identify genes whose reduced expression modifies the severity of this locomotor phenotype. Our initial finding was that none of the human orthologues of these worm genes is identical with the genome-wide significant GWAS genes reported to date (the "white zone"); moreover there was no identity between worm screen hits and the longer list of GWAS genes which included those with borderline levels of significance (the "grey zone"). This indicates that Aβ toxicity should not be considered as equivalent to sporadic AD. To increase the sensitivity of our analysis, we then considered the physical interactors (+1 interactome) of the products of the genes in both the worm and the white+grey zone lists. When we consider these worm and GWAS gene lists we find that 4 of the 60 worm genes have a +1 interactome overlap that is larger than expected by chance. Two of these genes form a chaperonin complex, the third is closely associated with this complex and the fourth gene codes for actin, the major substrate of the same chaperonin.

Bioimmunological responses to Schistosoma mansoni and Fasciola gigantica worm homogenates either with or without saponin.

PubMed

Maghraby, Amany Sayed; Hamed, Manal Abdel-Aziz; Ali, Sanaa Ahmed

2010-06-03

In this study, we evaluated the biochemical, immunological, histopathological and antischistosomal activities of Schistosoma mansoni or Fasciola gigantica worm homogenates mixed either with or without saponin that was extracted from Atriplex nummularia. The immunization schedule was based on subcutaneous administration of two doses (50 microg /100 microl PBS) of each homogenate with time intervals of 15 days. After 15 days of the last homogenate inoculation, all mice were challenged with 100 Schistosoma mansoni cercariae and sacrificed after two months. Free radical scavengers and liver function enzymes were determined in mice liver. Worm counting and the histopathological picture of the liver were also done. Immunization with Schistosoma or Fasciola worm homogenates, mixed either with or without saponin, recorded an amelioration of the free radical scavenger levels, liver function enzymes and reduction in worm burden, as well as improvement of the histological feature of the liver, the number and size of granuloma, evidence of increased immune reaction manifested by a lymphocytic cuff surrounding the granuloma, diminution of its fibrotic and collagen content, and destruction of Schistosoma ova. Fasciola or Schistosoma worm antigens mixed with or without saponin succeeded to eliminate the product of oxidative stress and assistance in immune-mediated destruction of eggs that ameliorate the histopathological picture of the liver cells and preserve its function.

Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil.

PubMed

Wilmsen, Maurício Orlando; Silva, Bruna Fernanda; Bassetto, César Cristiano; Amarante, Alessandro Francisco Talamini do

2014-01-01

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = -0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.

Faecal egg counts and expulsion dynamics of the whipworm, Trichuris trichiura following self-infection.

PubMed

Hansen, E P; Tejedor, A M; Thamsborg, S M; Alstrup Hansen, T V; Dahlerup, J F; Nejsum, P

2016-05-01

More than 400 million humans are estimated to be infected with the intestinal helminth parasite, Trichuris trichiura. The infection is chronic in nature and high-intensity infection can lead to colitis, anaemia, Trichuris Dysentery Syndrome and reduced cognitive performance. Single doses of 400 mg albendazole or 500 mg mebendazole (MBZ) are used in mass drug administration programmes, but this has been shown to be insufficient. In this study, worm expulsion dynamics are described after MBZ treatment, given as a multi-dose and single-dose treatment in two separate T. trichiura self-infection studies. Worm expulsion dynamics post-treatment showed a similar pattern regardless of the dose regime, with the first worms observed on day 2 and the last worms expelled on days 9 and 13 post-treatment. Establishment of a chronic infection was observed following the inefficient single-dose treatment. The prepatent period was 13-16 weeks in both studies and worms were found to have a lifespan of at least 1 year and 10 months. These self-infection studies provide key information on the chronicity of T. trichiura infections, expulsion dynamics after anthelmintic treatment and the prepatent period, as well as the fecundity of female worms, which was around 18,000 eggs/female per day.

Procyanidins from apples (Malus pumila Mill.) extend the lifespan of Caenorhabditis elegans.

PubMed

Sunagawa, Tadahiro; Shimizu, Takahiko; Kanda, Tomomasa; Tagashira, Motoyuki; Sami, Manabu; Shirasawa, Takuji

2011-01-01

Apple polyphenols (AP) mainly consist of procyanidins (PC), which are composed of (-)-epicatechins and (+)-catechins. In order to investigate the antiageing effects of PC, we measured the lifespan of CAENORHABDITIS ELEGANS worms treated with PC. Treatment with 65 µg/mL PC extended the mean lifespan of wild-type N2 and FEM-1 worms by 12.1 % and 8.4 %, respectively, i.e., to a similar extent as resveratrol. In addition, treatment with 100 µg/mL AP also significantly prolonged the mean lifespan of the same worms by 12.0 % and 5.3 %, respectively, i.e., to a similar extent as PC. In contrast, treatment with (-)-epicatechin did not extend the lifespan of the worms. PC did not modify the growth, food intake, or fecundity of C. elegans. Treatment with PC did not extend the lifespan of MEV-1 worms, which show excessive oxidative stress, indicating that PC had no antioxidant ability in the MEV-1 mutant. Moreover, treatment with PC had no effect on the longevity of SIR-2.1 worms, which lack the activity of SIR-2, a member of the sirtuin family of NAD (+)-dependent protein deacetylases. These results indicated that PC has SIR-2.1-dependent antiageing effects on C. elegans. © Georg Thieme Verlag KG Stuttgart · New York.

Schistosoma mansoni: is acquired immunity induced by highly x-irradiated cercariae dependent on the size of the challenging dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsue, S.Y.; Hsue, H.F.; Osborne, J.W.

1982-04-01

A high degree of immunity, as shown by a 91% reduction of the number of worms recovered was found in five groups of mice that were immunized five times with highly X-irradiated cercariae and then challenged with 10, 20, 50, 100, or 500 normal Schistosoma mansoni cercariae. The results indicated that there were no significant differences in worm reduction in immunized mice challenged with different numbers of cercariae; consequently the immunity induced by this immunization method did not appear to be challenge-dose-dependent. However, the results also showed that when immunized mice were challenged with 500, 100, 50, 20, and 10more » cercariae, 0, 13, 26, 56, and 68%, respectively, of the experimental animals were free of worms. Thus, the percentage of worm-negative cases increased as the number of challenge cercariae decreased. When viewed in this manner, the acquired immunity may be considered challenge-dose-dependent as well. If this method of vaccination is used for schistosomiasis control, we may anticipate that in both hypo- and hyperendemic areas, the intensity of infection and the severity of the disease will be reduced owing to a reduction in worms burdens, and in hypoendemic areas, there will be a number of worm-free cases.« less

Stocking Density Optimization for Enhanced Bioconversion of Fly Ash Enriched Vermicompost.

PubMed

Mupambwa, Hupenyu A; Mnkeni, Pearson N S

2016-05-01

Although it is widely agreed that stocking density critically affects the rate of vermicomposting, there is no established stocking density for mixtures of fly ash and other waste materials. This study sought to optimize (Savigny, 1826) stocking density for effective biodegradation and nutrient release in a fly ash-cow dung-waste paper (FCP) mixture. Four stocking densities of 0, 12.5, 25, and 37.5 g worms kg were evaluated. Although the 12.5, 25, and 37.5 g worms kg treatments all resulted in a mature vermicompost, stocking densities of 25 and 37.5 g worms kg resulted in faster maturity, higher humification parameters, and a significantly lower final C/N ratio (range 11.1-10.4). The activity of β-glucosidase and fluorescein diacetate hydrolysis enzymes showed faster stabilization at stocking densities of 25 and 37.5 g worms kg, indicating compost stability and maturity. Similarly, a stocking density of 25 g worms kg resulted in the highest release of Olsen-extractable P and (NO + NO)-N contents. The 0-, 12.5-, 25-, and 37.5-g treatments resulted in net Olsen P increases of 16.3, 38.9, 61.0, and 53.0%, respectively, after 10 wk. Although compost maturity could be attained at stocking densities of 12.5 g worms kg, for faster production of humified and nutrient-rich FCP vermicompost, a stocking density of 25 g worms kg seems most appropriate. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Eradication of dracunculiasis from Pakistan.

PubMed

Hopkins, D R; Azam, M; Ruiz-Tiben, E; Kappus, K D

1995-09-02

In 1986 the World Health Organization targeted dracunculiasis (Guinea-worm disease), which seriously impairs socioeconomic development in 16 African countries, India, Pakistan, and Yemen, to be eradicated globally. The target date for eradication by the end of 1995 was established in 1991. Pakistan eradicated dracunculiasis from the country in October, 1993, after a national campaign which began in 1987 with a nationwide village-by-village search for cases. The infection, which is transmitted by drinking water from ponds containing infected water fleas, was eradicated by using health education, cloth filters, and the cyclopsicide, temephos; and in the later stages, by case containment. Methods pioneered in Pakistan's National Guinea Worm Eradication Program are now being applied in remaining endemic countries.

AN ORIENTATIONAL RESPONSE TO WEAK GAMMA RADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, F.A. Jr.

1963-10-01

The common planarian worm, Duesia dorotocephsla, displays a significant orientational response to increase in Cs/sup 137/ gamma radiation when the increase is no greater than six times background. The worms are able to distinguish the direction of the weak gamma source, turning away from it, whether it is presented on the right or left side. The response sign is, therefore, the same as that of the response of these negatively phototactic worms to visible light. There is a clear compass-directional relationship of the responsiveness to the experimental gamma radiation. A conspicuous negative response is present when the worms are travelingmore » northward or southward in the earth's field with the gamma change in an east-west axis. No statistically significant mean turning response to the gamma radiation is found when the worms are traveling eastward or westward in the earth's field with the gamma change in a north-south axis. The previously observed annual fluctuation in the character of the monthly orientational rhythm of north-directed worms has been confirmed in an additional year of study. During colder months, the rhythm is monthly; during warmer months it is semi-monthly. There is a semi-monthly fluctuation in the response of Dugesia to weak gamma radiation during mid-morning hours, the worms turning away from the source for four days prior to new end full moon, and toward it for two days following new and full moon. The stronger the field strength, up to 9 times backgound, the larger the amplitude of the rhythm. There is a direct relationship between intensities of gamma radiation between that of background and nine times backgound, and the strength of the negative response of the worms. Evidence suggests that the negative response of Dugesia to a gamma source may be modified by experimental alteration of the natural ambient electrostatic field. Some possible biological significances of this remarkable responsiveness to gamma radiation, and its particular properties, are discussed briefly. (auth)« less

Uptake of TiO2 Nanoparticles into C. elegans Neurons Negatively Affects Axonal Growth and Worm Locomotion Behavior.

PubMed

Hu, Chun-Chih; Wu, Gong-Her; Hua, Tzu-En; Wagner, Oliver I; Yen, Ta-Jen

2018-03-14

We employ model organism Caenorhabditis elegans to effectively study the toxicology of anatase and rutile phase titanium dioxide (TiO 2 ) nanoparticles (NPs). The experimental results show that nematode C. elegans can take up fluorescein isothiocyanate-labeled TiO 2 NPs and that both anatase and rutile TiO 2 NPs can be detected in the cytoplasm of cultured primary neurons imaged by transmission electron microscopy. After TiO 2 NP exposure, these neurons also grow shorter axons, which may be related to the detected impeded worm locomotion behavior. Furthermore, anatase TiO 2 NPs did not affect the worm's body length; however, we determined that a concentration of 500 μg/mL of anatase TiO 2 NPs reduced the worm population by 50% within 72 h. Notably, rutile TiO 2 NPs negatively affect both the body size and worm population. Worms unable to enter the L4 larval stage explain a severe reduction in the worm population at TiO 2 NPs LC 50 /3d. To obtain a better understanding of the cellular mechanisms involved in TiO 2 NP intoxication, DNA microarray assays were employed to determine changes in gene expression in the presence or absence of TiO 2 NP exposure. Our data reveal that three genes (with significant changes in expression levels) were related to metal binding or metal detoxification (mtl-2, C45B2.2, and nhr-247), six genes were involved in fertility and reproduction (mtl-2, F26F2.3, ZK970.7, clec-70, K08C9.7, and C38C3.7), four genes were involved in worm growth and body morphogenesis (mtl-2, F26F2.3, C38C3.7, and nhr-247), and five genes were involved in neuronal function (C41G6.13, C45B2.2, srr-6, K08C9.7, and C38C3.7).

C. elegans positive butanone learning, short-term, and long-term associative memory assays.

PubMed

Kauffman, Amanda; Parsons, Lance; Stein, Geneva; Wills, Airon; Kaletsky, Rachel; Murphy, Coleen

2011-03-11

The memory of experiences and learned information is critical for organisms to make choices that aid their survival. C. elegans navigates its environment through neuron-specific detection of food and chemical odors, and can associate nutritive states with chemical odors, temperature, and the pathogenicity of a food source. Here, we describe assays of C. elegans associative learning and short- and long-term associative memory. We modified an aversive olfactory learning paradigm to instead produce a positive response; the assay involves starving ~400 worms, then feeding the worms in the presence of the AWC neuron-sensed volatile chemoattractant butanone at a concentration that elicits a low chemotactic index (similar to Toroyama et al.). A standard population chemotaxis assay1 tests the worms' attraction to the odorant immediately or minutes to hours after conditioning. After conditioning, wild-type animals' chemotaxis to butanone increases ~0.6 Chemotaxis Index units, its "Learning Index". Associative learning is dependent on the presence of both food and butanone during training. Pairing food and butanone for a single conditioning period ("massed training") produces short-term associative memory that lasts ~2 hours. Multiple conditioning periods with rest periods between ("spaced training") yields long-term associative memory (<40 hours), and is dependent on the cAMP Response Element Binding protein (CREB), a transcription factor required for long-term memory across species. Our protocol also includes image analysis methods for quick and accurate determination of chemotaxis indices. High-contrast images of animals on chemotaxis assay plates are captured and analyzed by worm counting software in MatLab. The software corrects for uneven background using a morphological tophat transformation. Otsu's method is then used to determine a threshold to separate worms from the background. Very small particles are removed automatically and larger non-worm regions (plate edges or agar punches) are removed by manual selection. The software then estimates the size of single worm by ignoring regions that are above a specified maximum size and taking the median size of the remaining regions. The number of worms is then estimated by dividing the total area identified as occupied by worms by the estimated size of a single worm. We have found that learning and short- and long-term memory can be distinguished, and that these processes share similar key molecules with higher organisms. Our assays can quickly test novel candidate genes or molecules that affect learning and short- or long-term memory in C. elegans that are relevant across species.

Training the next generation of scientists: Modeling Infectious Disease and Water Quality of Montana Streams

NASA Astrophysics Data System (ADS)

Fytilis, N.; Wyman, S.; Lamb, R.; Stevens, L.; Kerans, B.; Rizzo, D. M.

2010-12-01

The University of Vermont College of Engineering and Mathematical Sciences and the Barrett Foundation have established a scholarship program for undergraduate students. The Barrett Scholarship program, aware of the importance of developing research quantitative and writing skills for undergraduate students, provides scholarships to outstanding undergraduate students for environmental engineering research projects. The intent is to help retain student interest early in their undergraduate engineering careers when few of their first or second year classes have little engineering or real-world application. We focus on one Barrett research project, derived from a NSF Biodiversity and Infectious Disease grant, because of the multiple disciplines (engineering, ecology, biology) and education levels (spanning secondary to graduate) involved. In this research, students across three departments at two universities (University of Vermont, Montana State University) and one independent high school (Vermont Commons School) formed a cohesive collaboration with faculty members to identify different worm taxa of T. Tubifex. Whirling disease has had a severe impact on the native population of salmonids in the upper Madison River MT, USA, resulting in the death of most fish that contract the parasite. T. Tubifex is the intermediate host for Myxobolus cerebralis, the parasite that causes whirling disease in salmonids. Samples collected from eight locations along the Madison River varied in the prevalence of whirling disease. The site-specific worm community structure has been measured and identified using molecular genetic probes and a taxonomic key to link worm communities to geochemical features (e.g. site elevation, slope, pH, conductivity, temperature, dissolved oxygen and percent of organic soil matter). Using a unique clustering algorithm, we group geochemical features to discriminate over a range of water quality gradients (i.e., “clean” to “dirty”). The link between water quality and the presence of these taxa is important in determining stream health. In addition, system dynamics software (STELLA) is used to model the non-linear relationships and feedback between worm prevalence and disease dynamics. These types of collaborations between engineers, biologists, field ecologists and geneticists from secondary, post-secondary and higher institutions proved useful in linking complex geochemical data, worm community structure and molecular genetics to develop the next-generation scientists and better understand disease dynamics.

Genetic Selection of Low Fertile Onchocerca volvulus by Ivermectin Treatment

PubMed Central

Bourguinat, Catherine; Pion, Sébastien D. S.; Kamgno, Joseph; Gardon, Jacques

2007-01-01

Background Onchocerca volvulus is the causative agent of onchocerciasis, or “river blindness”. Ivermectin has been used for mass treatment of onchocerciasis for up to 18 years, and recently there have been reports of poor parasitological responses to the drug. Should ivermectin resistance be developing, it would have a genetic basis. We monitored genetic changes in parasites obtained from the same patients before use of ivermectin and following different levels of ivermectin exposure. Methods and Findings O. volvulus adult worms were obtained from 73 patients before exposure to ivermectin and in the same patients following three years of annual or three-monthly treatment at 150 µg/kg or 800 µg/kg. Genotype frequencies were determined in β-tubulin, a gene previously found to be linked to ivermectin selection and resistance in parasitic nematodes. Such frequencies were also determined in two other genes, heat shock protein 60 and acidic ribosomal protein, not known to be linked to ivermectin effects. In addition, we investigated the relationship between β-tubulin genotype and female parasite fertility. We found a significant selection for β-tubulin heterozygotes in female worms. There was no significant selection for the two other genes. Quarterly ivermectin treatment over three years reduced the frequency of the β-tubulin “aa” homozygotes from 68.6% to 25.6%, while the “ab” heterozygotes increased from 20.9% to 69.2% in the female parasites. The female worms that were homozygous at the β-tubulin locus were more fertile than the heterozygous female worms before treatment (67% versus 37%; p = 0.003) and twelve months after the last dose of ivermectin in the groups treated annually (60% versus 17%; p<0.001). Differences in fertility between heterozygous and homozygous worms were less apparent three months after the last treatment in the groups treated three-monthly. Conclusions The results indicate that ivermectin is causing genetic selection on O. volvulus. This genetic selection is associated with a lower reproductive rate in the female parasites. We hypothesize that this genetic selection indicates that a population of O. volvulus, which is more tolerant to ivermectin, is being selected. This selection could have implications for the development of ivermectin resistance in O. volvulus and for the ongoing onchocerciasis control programmes. PMID:17989786

Biology and ecology of the ``Pompeii worm'' (Alvinella pompejana Desbruyères and Laubier), a normal dweller of an extreme deep-sea environment: A synthesis of current knowledge and recent developments

NASA Astrophysics Data System (ADS)

Desbruyères, D.; Chevaldonné, P.; Alayse, A.-M.; Jollivet, D.; Lallier, F. H.; Jouin-Toulmond, C.; Zal, F.; Sarradin, P.-M.; Cosson, R.; Caprais, J.-C.; Arndt, C.; O'Brien, J.; Guezennec, J.; Hourdez, S.; Riso, R.; Gaill, F.; Laubier, L.; Toulmond, A.

1998-01-01

Alvinella pompejana, the "Pompeii worm" lives on active hydrothermal edifices at deep-sea vents of the East Pacific Rise. The physical and chemical patterns of its microhabitat were determined from temperature probe measurements, temperature time series, and on-board and shore-based chemical analyses based on discrete sampling (pH, H 2S, CO 2, CH 4, S 2O 2-3, Ca, Mg, Cu, Cd, Zn). The microhabitat is characterised by high temporal and microscale spatial variability, with temperature values in the range of 20°-45°C at the immediate periphery of tubes but reaching higher, still undetermined, values inside the tubes. The difference observed between in vitro temperature limits for the stability of biomolecules and metabolic rates, and suggested in situ conditions seems to indicate a significant protective role of biological interfaces (tubes and cuticle). Temporal instability possibly also plays an important role in the ability for these worms to colonise such an extreme habitat. The functional role of dominant epibiotic bacteria is discussed in the light of recent biochemical and molecular data: the tube-worm-bacteria system can be considered as a symbiotic entity where carbon is probably metabolised and recycled. Sulphide detoxification occurs by oxidation at the gill level and possibly at the intracellular haemoglobin level. Heavy metals, ingested or absorbed, are trapped in spherocrystals and bound to metallothionein-like proteins. Anatomical, physiological and molecular adaptations to hypoxia allow the worm to successfully colonise the chimneys. A. pompejana lives in an ephemeral environment and must reproduce and disperse accordingly. It is a gonochoric species that displays a pseucopulatory behaviour allowing transfer of sperm to female spermathecae, thus avoiding dispersion of the gametes. The size of the oocytes suggests a lecithotrophic or benthic development. The population size structure is polymodal, indicating discontinuous recruitment. Population genetics data indicate the occurrence of a microscale level of population differentiation that does not increase with increasing geographical distances, thus suggesting the occurrence of a metapopulation-like system and/or the possibility that enzyme loci evolve under stabilising selective driving forces inherent to the vents' highly variable conditions.

Arrested development of the myxozoan parasite, Myxobolus cerebralis, in certain populations of mitochondrial 16S lineage III Tubifex tubifex.

PubMed

Baxa, D V; Kelley, G O; Mukkatira, K S; Beauchamp, K A; Rasmussen, C; Hedrick, R P

2008-01-01

Laboratory populations of Tubifex tubifex from mitochondrial (mt)16S ribosomal DNA (rDNA) lineage III were generated from single cocoons of adult worms releasing the triactinomyxon stages (TAMs) of the myxozoan parasite, Myxobolus cerebralis. Subsequent worm populations from these cocoons, referred to as clonal lines, were tested for susceptibility to infection with the myxospore stages of M. cerebralis. Development and release of TAMs occurred in five clonal lines, while four clonal lines showed immature parasitic forms that were not expelled from the worm (non-TAM producers). Oligochaetes from TAM- and non-TAM-producing clonal lines were confirmed as lineage III based on mt16S rDNA and internal transcribed spacer region 1 (ITS1) sequences, but these genes did not differentiate these phenotypes. In contrast, random amplified polymorphic DNA analyses of genomic DNA demonstrated unique banding patterns that distinguished the phenotypes. Cohabitation of parasite-exposed TAM- and non-TAM-producing phenotypes showed an overall decrease in expected TAM production compared to the same exposure dose of the TAM-producing phenotype without cohabitation. These studies suggest that differences in susceptibility to parasite infection can occur in genetically similar T. tubifex populations, and their coexistence may affect overall M. cerebralis production, a factor that may influence the severity of whirling disease in wild trout populations.

Drug-like analogues of the parasitic worm-derived immunomodulator ES-62 are therapeutic in the MRL/Lpr model of systemic lupus erythematosus

PubMed Central

Rodgers, D T; Pineda, M A; Suckling, C J; Harnett, W

2015-01-01

Introduction ES-62, a phosphorylcholine (PC)-containing immunomodulator secreted by the parasitic worm Acanthocheilonema viteae, protects against nephritis in the MRL/Lpr mouse model of systemic lupus erythematosus (SLE). However, ES-62 is not suitable for development as a therapy and thus we have designed drug-like small molecule analogues (SMAs) based around its active PC-moiety. To provide proof of concept that ES-62-based SMAs exhibit therapeutic potential in SLE, we have investigated the capacity of two SMAs to protect against nephritis when administered to MRL/Lpr mice after onset of kidney damage. Methods SMAs 11a and 12b were evaluated for their ability to suppress antinuclear antibody (ANA) generation and consequent kidney pathology in MRL/Lpr mice when administered after the onset of proteinuria. Results SMAs 11a and 12b suppressed development of ANA and proteinuria. Protection reflected downregulation of MyD88 expression by kidney cells and this was associated with reduced production of IL-6, a cytokine that exhibits promise as a therapeutic target for this condition. Conclusions SMAs 11a and 12b provide proof of principle that synthetic compounds based on the safe immunomodulatory mechanisms of parasitic worms can exhibit therapeutic potential as a novel class of drugs for SLE, a disease for which current therapies remain inadequate. PMID:26085597

Arrested development of the myxozoan parasite, Myxobolus cerebralis, in certain populations of mitochondrial 16S lineage III Tubifex tubifex

USGS Publications Warehouse

Baxa, D.V.; Kelley, G.O.; Mukkatira, K.S.; Beauchamp, K.A.; Rasmussen, C.; Hedrick, R.P.

2008-01-01

Laboratory populations of Tubifex tubifex from mitochondrial (mt)16S ribosomal DNA (rDNA) lineage III were generated from single cocoons of adult worms releasing the triactinomyxon stages (TAMs) of the myxozoan parasite, Myxobolus cerebralis. Subsequent worm populations from these cocoons, referred to as clonal lines, were tested for susceptibility to infection with the myxospore stages of M. cerebralis. Development and release of TAMs occurred in five clonal lines, while four clonal lines showed immature parasitic forms that were not expelled from the worm (non-TAM producers). Oligochaetes from TAM- and non-TAM-producing clonal lines were confirmed as lineage III based on mt16S rDNA and internal transcribed spacer region 1 (ITS1) sequences, but these genes did not differentiate these phenotypes. In contrast, random amplified polymorphic DNA analyses of genomic DNA demonstrated unique banding patterns that distinguished the phenotypes. Cohabitation of parasite-exposed TAM- and non-TAM-producing phenotypes showed an overall decrease in expected TAM production compared to the same exposure dose of the TAM-producing phenotype without cohabitation. These studies suggest that differences in susceptibility to parasite infection can occur in genetically similar T. tubifex populations, and their coexistence may affect overall M. cerebralis production, a factor that may influence the severity of whirling disease in wild trout populations. ?? 2007 Springer-Verlag.

Comparative life cycles and life histories of North American Rhabdias spp. (Nematoda: Rhabdiasidae): lungworms from snakes and anurans.

PubMed

Langford, Gabriel J; Janovy, John

2009-10-01

The present study used experimental infections to compare the life cycles and life histories of 6 Rhabdias spp. infecting snakes and anurans. Free-living development of anuran lungworms was primarily limited to heterogonic reproduction, and females utilized matricidal endotoky exclusively, whereas snake lungworms primarily reproduced homogonically and, when heterogonic reproduction occurred, females used a combination of releasing eggs and matricidal endotoky. Infective snake lungworms survived for longer periods in fresh water compared to anuran worms. Infective anuran lungworms penetrated into the skin of frogs and toads; few infections resulted from per os infections. In contrast, snake lungworms were unable to penetrate skin; instead, infective juveniles penetrated into snake esophageal tissue during per os infections. Despite separate points of entry, anuran and snake lungworms both migrated and developed in the fascia, eventually penetrating into the body cavity of the host. Worms molted to adulthood inside the body cavity and subsequently penetrated into the host's lungs, where they fed on blood while becoming gravid. Adult lungworm survival varied among lungworm species, but, in general, snake lungworms were longer lived than anuran worms. Anuran lungworms were poorly suited for transmission via transport hosts, whereas snake lungworms were consistently capable of establishing infections using transport hosts. Overall, these observations suggest that snake and anuran lungworms have discrepant life cycles and life history strategies.

Gizzard worms

USGS Publications Warehouse

Tuggle, B.N.; Friend, M.

1999-01-01

Gizzard worms are comprised of several species of parasitic nematodes or roundworms of birds. Severe infections can result in birds becoming unthrifty and debilitated to the extent that they are more susceptible to predation and to infection by other disease agents. The two gizzard worms that are emphasized here are trichostrongylid nematodes that belong to the genera Amidostomum sp. and Epomidiostomum sp. These long (10–35 millimeter), sometimes coiled, threadlike roundworms are found just beneath the surface lining and the grinding pads of the gizzard, and they are most frequently found in waterfowl. Other species of gizzard worms are found in upland gamebirds such as grouse, in psitticine birds such as parakeets, and in passerine or perching birds such as robins in various parts of the world.

Podoconiosis, non-filarial elephantiasis, and lymphology.

PubMed

Davey, G

2010-12-01

Several recent reviews of podoconiosis already exist in journals and on public access websites. After briefly covering the historical and epidemiological background, this narrative review will therefore attempt explicitly to link podoconiosis with lymphology, examining gaps in what is known of pathogenesis and identifying the areas of research in which input from lymphologists is most required. Finally, prevention and treatment will be described and the need for operational research to optimize community-based interventions outlined.

Antibody Responses in the Nonhuman Primate, Macaca Fascicularis, to Protein Toxins

DTIC Science & Technology

1990-05-01

generation of tetanus-specific antibody, producing B cells after in vivo immunization of Crohn’s dis- ease and ulcerative colitis patients ...lty Codes APPROVED: Noat eoa Sanford Millef, Ph.D. Dean CON;’ DEDICATION 1 his thesis is dedicated to the ones who so patiently tucked away their...were expermentally infected with Brugia milayi, a human filarial parasite , and antibody levels followed by enzyme linked immunosorbant assay (ELISA

WormGUIDES: an interactive single cell developmental atlas and tool for collaborative multidimensional data exploration.

PubMed

Santella, Anthony; Catena, Raúl; Kovacevic, Ismar; Shah, Pavak; Yu, Zidong; Marquina-Solis, Javier; Kumar, Abhishek; Wu, Yicong; Schaff, James; Colón-Ramos, Daniel; Shroff, Hari; Mohler, William A; Bao, Zhirong

2015-06-09

Imaging and image analysis advances are yielding increasingly complete and complicated records of cellular events in tissues and whole embryos. The ability to follow hundreds to thousands of cells at the individual level demands a spatio-temporal data infrastructure: tools to assemble and collate knowledge about development spatially in a manner analogous to geographic information systems (GIS). Just as GIS indexes items or events based on their spatio-temporal or 4D location on the Earth these tools would organize knowledge based on location within the tissues or embryos. Developmental processes are highly context-specific, but the complexity of the 4D environment in which they unfold is a barrier to assembling an understanding of any particular process from diverse sources of information. In the same way that GIS aids the understanding and use of geo-located large data sets, software can, with a proper frame of reference, allow large biological data sets to be understood spatially. Intuitive tools are needed to navigate the spatial structure of complex tissue, collate large data sets and existing knowledge with this spatial structure and help users derive hypotheses about developmental mechanisms. Toward this goal we have developed WormGUIDES, a mobile application that presents a 4D developmental atlas for Caenorhabditis elegans. The WormGUIDES mobile app enables users to navigate a 3D model depicting the nuclear positions of all cells in the developing embryo. The identity of each cell can be queried with a tap, and community databases searched for available information about that cell. Information about ancestry, fate and gene expression can be used to label cells and craft customized visualizations that highlight cells as potential players in an event of interest. Scenes are easily saved, shared and published to other WormGUIDES users. The mobile app is available for Android and iOS platforms. WormGUIDES provides an important tool for examining developmental processes and developing mechanistic hypotheses about their control. Critically, it provides the typical end user with an intuitive interface for developing and sharing custom visualizations of developmental processes. Equally important, because users can select cells based on their position and search for information about them, the app also serves as a spatially organized index into the large body of knowledge available to the C. elegans community online. Moreover, the app can be used to create and publish the result of exploration: interactive content that brings other researchers and students directly to the spatio-temporal point of insight. Ultimately the app will incorporate a detailed time lapse record of cell shape, beginning with neurons. This will add the key ability to navigate and understand the developmental events that result in the coordinated and precise emergence of anatomy, particularly the wiring of the nervous system.

New 1,3-benzodioxole derivatives: Synthesis, evaluation of in vitro schistosomicidal activity and ultrastructural analysis.

PubMed

Mariz Gomes da Silva, Luana Maria; de Oliveira, Jamerson Ferreira; Silva, Willams Leal; da Silva, Anekecia Lauro; de Almeida Junior, Antônio Sérgio Alves; Barbosa Dos Santos, Victor Hugo; Alves, Luiz Carlos; Brayner Dos Santos, Fábio André; Costa, Vlaudia Maria Assis; Aires, André de Lima; de Lima, Maria do Carmo Alves; Albuquerque, Monica Camelo Pessoa de Azevedo

2018-03-01

Schistosomiasis is considered a serious public health problem in 78 countries and territories located in Africa, Asia and America and it is estimated in more than 249 million people infected by any of the species of Schistosoma. The exclusive use of praziquantel (PZQ), effective drug against all species of Schistosoma, has been the basis of the development of a possible resistance against the strains of this parasite. In addition, PZQ is not effective against young forms of worms. Thus, there is a need for the development of new drugs with schistosomicidal activity. The objective of this work was to synthesize and to evaluate the therapeutic potential of new benzodioxole derivatives (3-14) candidates for schistosomicidal drugs. All compounds synthesized showed in vitro schistosomicidal activity. The derivative 12 was considered the best compound, since it took 100% of worms to mortality in the first 72 h of exposure at the concentration of 100 μM and 83.3% at the concentration of 50 μM. Furthermore, male and female adult worms, incubated for 24 h with the compound 12 showed tegument damages characterized by extensive desquamation and edema, tuber destruction, bubble formation and exposure of the muscle layer. This compound has a restricted structure, where the thiazolidinone is attached to the 4-position of the 1,3-benzodioxol ring. The structural conformation of derivative 12 was probably responsible for the promising schistosomicidal activity, where the presence of an electron/conformational restriction of the thiazolidine ring, as well as the action of bromine as a bulk substitute, favored an increase in biological activity. In addition, tegumentary changes caused by derivative 12 may also have been responsible for the death of adult worms of Schistosoma mansoni. Therefore, we verified that the results obtained in this study make benzodioxole derivatives possible candidates for prototypes of new schistosomicidal drugs. Copyright © 2018 Elsevier B.V. All rights reserved.

Brugia pahangi: Immunization with early L3 ES alters parasite migration, and reduces microfilaremia and lymphatic lesion formation in gerbils (Meriones unguiculatus)

PubMed Central

Zipperer, Ginger R.; Arumugam, Sridhar; Chirgwin, Sharon R.; Coleman, Sharon U.; Shakya, Krishna P.; Klei, Thomas R.

2013-01-01

Previous studies have shown that intradermally (ID) injected B. pahangi L3s migrate through various tissues and into the lymphatics of gerbils in a distinct pattern. Excretory/secretory products (ES) produced at the time of invasion of B. pahangi are likely to be important in this early migration phase of the parasite life cycle in their rodent host. Hence, early L3 ES was collected from 24 hr in vitro cultures of B. pahangi L3 larvae and used in immunization experiments to investigate the effect of immunity to early L3 ES on worm migration, survival and development of B. pahangi. Immunization of gerbils with ES in RIBI adjuvant produced antibodies to numerous ES proteins eliciting a strong humoral response to ES and indirect fluorescent antibody (IFA) assay using anti-ES serum recognized the ES proteins on the surface of B. pahangi L3 larvae. Following ES immunization, gerbils were challenged either ID or intraperitoneally (IP) with 100 L3s of B. pahangi and euthanized at 3 or 106 days post inoculation (DPI). Immunization with early ES slowed the migration of ID inoculated L3 at 3DPI and significantly altered the locations of adult worms at 106 DPI. Immunization did not induce protection in any treatment group. However, immunized animals had significantly fewer microfilariae per female worm suggesting the antigens in ES are important in microfilariae development or survival in the host. The number of lymphatic granulomas was also significantly reduced in ES immunized animals. It is important to note that microfilariae serve as a nidus in these granulomas. Our results shows immunization with early B. malayi L3 ES alters the worm migration, affects circulating microfilarial numbers and reduces lymphatic granulomas associated with B. pahangi infection in gerbils. PMID:23981910

Preparation of Pickering Double Emulsions Using Block Copolymer Worms

PubMed Central

2015-01-01

The rational formulation of Pickering double emulsions is described using a judicious combination of hydrophilic and hydrophobic block copolymer worms as highly anisotropic emulsifiers. More specifically, RAFT dispersion polymerization was utilized to prepare poly(lauryl methacrylate)–poly(benzyl methacrylate) worms at 20% w/w solids in n-dodecane and poly(glycerol monomethacrylate)–poly(2-hydroxypropyl methacrylate)–poly(benzyl methacrylate) worms at 13% w/w solids in water by polymerization-induced self-assembly (PISA). Water-in-oil-in-water (w/o/w) double emulsions can be readily prepared with mean droplet diameters ranging from 30 to 80 μm using a two-stage approach. First, a w/o precursor emulsion comprising 25 μm aqueous droplets is prepared using the hydrophobic worms, followed by encapsulation within oil droplets stabilized by the hydrophilic worms. The double emulsion droplet diameter and number of encapsulated water droplets can be readily varied by adjusting the stirring rate employed during the second stage. For each stage, the droplet volume fraction is relatively high at 0.50. The double emulsion nature of the final formulation was confirmed by optical and fluorescence microscopy studies. Such double emulsions are highly stable to coalescence, with little or no change in droplet diameter being detected over storage at 20 °C for 10 weeks as judged by laser diffraction. Preliminary experiments indicate that the complementary o/w/o emulsions can also be prepared using the same pair of worms by changing the order of homogenization, although somewhat lower droplet volume fractions were required in this case. Finally, we demonstrate that triple and even quadruple emulsions can be formulated using these new highly anisotropic Pickering emulsifiers. PMID:25834923

Mortality of Rocky Mountain elk in Michigan due to meningeal worm.

PubMed

Bender, Louis C; Schmitt, Stephen M; Carlson, Elaine; Haufler, Jonathan B; Beyer, Dean E

2005-01-01

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (>or=12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.000), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and >or=3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (>or=14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of >or=18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. It is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations.

Mortality of rocky mountain elk in Michigan due to meningeal worm

USGS Publications Warehouse

Bender, L.C.; Schmitt, S.M.; Carlson, E.; Haufler, J.B.; Beyer, D.E.

2005-01-01

Mortality from cerebrospinal parelaphostrongylosis caused by the meningeal worm (Parelaphostrongylus tenuis) has been hypothesized to limit elk (Cervus elaphus nelsoni) populations in areas where elk are conspecific with white-tailed deer (Odocoileus virginianus). Elk were reintroduced into Michigan (USA) in the early 1900s and subsequently greatly increased population size and distribution despite sympatric high-density (???12/km2) white-tailed deer populations. We monitored 100 radio-collared elk of all age and sex classes from 1981-94, during which time we documented 76 mortalities. Meningeal worm was a minor mortality factor for elk in Michigan and accounted for only 3% of mortalities, fewer than legal harvest (58%), illegal kills (22%), other diseases (7%), and malnutrition (4%). Across years, annual cause-specific mortality rates due to cerebrospinal parelaphostrongylosis were 0.033 (SE=0.006), 0.029 (SE=0.005), 0.000 (SE=0.001), and 0.000 (SE=0.000) for calves, 1-yr-old, 2-yr-old, and ???3-yr-old, respectively. The overall population-level mortality rate due to cerebrospinal parelaphostrongylosis was 0.009 (SE=0.001). Thus, meningeal worm had little impact on elk in Michigan during our study despite greater than normal precipitation (favoring gastropods) and record (???14 km2) deer densities. Further, elk in Michigan have shown sustained population rates-of-increase of ???18%/yr and among the highest levels of juvenile production and survival recorded for elk in North America, indicating that elk can persist in areas with meningeal worm at high levels of population productivity. it is likely that local ecologic characteristics among elk, white-tailed deer, and gastropods, and degree of exposure, age of elk, individual and population experience with meningeal worm, overall population vigor, and moisture determine the effects of meningeal worm on elk populations. ?? Wildlife Disease Association 2005.

Eradicating guinea worm without wells: unrealized hopes of the Water Decade.

PubMed

Brieger, W R; Otusanya, S; Adeniyi, J D; Tijani, J; Banjoko, M

1997-12-01

At the start of the United Nations International Drinking Water Supply and Sanitation Decade in the 1980s, guinea worm disease was targeted as the major indicator of the success of the Decade's efforts to promote safe water. By the late 1980s, most of the guinea worm endemic countries in Africa and South Asia had established guinea worm eradication programmes that included water supply as one of their main technical strategies. By surveying the water supply situation in Ifeloju Local Government Area (LGA) in Oyo State, Nigeria, in June 1996, as a case study, it was possible to determine the role that water supply has played in the eradication effort. Although two major agencies, the former Directorate for Food, Roads and Rural Infrastructure and UNICEF, provided hand dug and bore-hole wells respectively in many parts of the LGA, coverage of the smaller farm hamlets has been minor compared to efforts in the larger towns. This is ironic because the farm hamlets served as a reservoir for the disease in the 1980s, such that when the piped water system in the towns broke down, guinea worm was easily reintroduced into the towns. The survey of 188 ever-endemic hamlets with an estimated population of 23,556 found that 74.3% of the people still drink only pond water. Another 11.3% have wells that have become dysfunctional. Only 14.4% of this rural population has access' to functioning wells. Guinea worm was eliminated from 107 of the hamlets mainly by the use of cloth filters and chemical treatment of ponds. While this proves that it is possible to eradicate guinea worm, it fails to leave behind the legacy of reliable, safe water supplies that was the hope of the Water Decade.

Predicting path from undulations for C. elegans using linear and nonlinear resistive force theory.

PubMed

Keaveny, Eric E; Brown, André E X

2017-03-22

A basic issue in the physics of behaviour is the mechanical relationship between an animal and its surroundings. The model nematode C. elegans provides an excellent platform to explore this relationship due to its anatomical simplicity. Nonetheless, the physics of nematode crawling, in which the worm undulates its body to move on a wet surface, is not completely understood and the mathematical models often used to describe this phenomenon are empirical. We confirm that linear resistive force theory, one such empirical model, is effective at predicting a worm's path from its sequence of body postures for forward crawling, reversing, and turning and for a broad range of different behavioural phenotypes observed in mutant worms. Worms recently isolated from the wild have a higher effective drag anisotropy than the laboratory-adapted strain N2 and most mutant strains. This means the wild isolates crawl with less surface slip, perhaps reflecting more efficient gaits. The drag anisotropies required to fit the observed locomotion data (70  ±  28 for the wild isolates) are significantly larger than the values measured by directly dragging worms along agar surfaces (3-10 in Rabets et al (2014 Biophys. J. 107 1980-7)). A proposed nonlinear extension of the resistive force theory model also provides accurate predictions, but does not resolve the discrepancy between the parameters required to achieve good path prediction and the experimentally measured parameters. We confirm that linear resistive force theory provides a good effective model of worm crawling that can be used in applications such as whole-animal simulations and advanced tracking algorithms, but that the nature of the physical interaction between worms and their most commonly studied laboratory substrate remains unresolved.

Study of the Feasibility of Using an Advanced Opto-Electronic Imaging Technique for Sampling Mid-Water Nekton.

DTIC Science & Technology

1978-11-30

migration(diurnal) of Mycophidae and siphonophores of the suborder Physonectae. —2— _______ - ~~~~~~~~~~ _____________________________ I-~ The former...ORGANISMS PLANKTON COPEPODS TRANSLUCENT ! ARROW WORMS TRANSPARENT SIPHONOPHORES MEDUSAE AGLISCRA IGNEA FLAMING RED NEMERTEAN WORMS REDDISH ARROW WORMS...383-385 ( 1969) 9. BARHAN, Eric G., Siphonophores and the Deep Scattering Layer, Science, 140, 826—828 (1963) 10. BARHA~M , Eric C., Deep Scattering

Worm Grunting, Fiddling, and Charming—Humans Unknowingly Mimic a Predator to Harvest Bait

PubMed Central

Catania, Kenneth C.

2008-01-01

Background For generations many families in and around Florida's Apalachicola National Forest have supported themselves by collecting the large endemic earthworms (Diplocardia mississippiensis). This is accomplished by vibrating a wooden stake driven into the soil, a practice called “worm grunting”. In response to the vibrations, worms emerge to the surface where thousands can be gathered in a few hours. Why do these earthworms suddenly exit their burrows in response to vibrations, exposing themselves to predation? Principal Findings Here it is shown that a population of eastern American moles (Scalopus aquaticus) inhabits the area where worms are collected and that earthworms have a pronounced escape response from moles consisting of rapidly exiting their burrows to flee across the soil surface. Recordings of vibrations generated by bait collectors and moles suggest that “worm grunters” unknowingly mimic digging moles. An alternative possibility, that worms interpret vibrations as rain and surface to avoid drowning is not supported. Conclusions Previous investigations have revealed that both wood turtles and herring gulls vibrate the ground to elicit earthworm escapes, indicating that a range of predators may exploit the predator-prey relationship between earthworms and moles. In addition to revealing a novel escape response that may be widespread among soil fauna, the results show that humans have played the role of “rare predators” in exploiting the consequences of a sensory arms race. PMID:18852902

Distribution and movement of Caenorhabditis elegans on a thermal gradient.

PubMed

Yamada, Yohko; Ohshima, Yasumi

2003-08-01

To analyze thermal responses of Caenorhabditis elegans in detail, distribution of a worm population and movement of individual worms were examined on a linear, reproducible and broad temperature gradient. Assay methods were improved compared with those reported previously to ensure good motility and dispersion of worms. Well-fed, wild-type worms distributed over a wide temperature range of up to 10 degrees C, and, within this range, worms migrated in both directions of the gradient at similar frequencies without any specific response to the growth temperature in most cases. By contrast, worms migrated down the gradient if put in a region warmer than the warm boundary of distribution. The distribution range changed depending on the growth temperature and starvation, but active avoidance of a starvation temperature was not detected. These findings contradict previous hypotheses of taxis or migration to the growth temperature in association with food and instead indicate avoidance of a warm temperature. Our results favor a model for thermal response of C. elegans that postulates a single drive based on warm sensation rather than downward and upward drives in the physiological temperature range. Mutants in ttx-3, tax-2, tax-4 or egl-4 genes showed abnormal thermal responses, suggesting that these genes are involved in warm avoidance. Laser ablation and gene expression studies suggest that AFD neurons are not important, and tax-4 expression in neurons other than AFD is required, for warm avoidance.

Identification of Fasciola species based on mitochondrial and nuclear DNA reveals the co-existence of intermediate Fasciola and Fasciola gigantica in Thailand.

PubMed

Wannasan, Anchalee; Khositharattanakool, Pathamet; Chaiwong, Prasong; Piangjai, Somsak; Uparanukraw, Pichart; Morakote, Nimit

2014-11-01

Molecular techniques were used to identify Fasciola species collected from Chiang Mai Thailand. Morphometrically, 65 stained and 45 fresh worms collected from cattle suggested the possible occurrence of both F. gigantica and F. hepatica. Twenty-two worms comprising 15 from cattle and 7 from human patients, were identified subsequently based on three genetic markers: mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1), mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS2). All of them presented the F. gigantica type in maternally inherited mitochondrial sequences (nad1 and cox1), with six types in each sequence (FgNDI-CM1 to FgNDI-CM6 and FgCOI-CM1 to FgCOI-CM6, respectively). Remarkably, the predominant nad1 type, FgNDI-CM6, was identical to that of aspermic Fasciola sp. formerly reported from Thailand, Japan, Korea, China, Vietnam, and Myanmar. ITS2 sequences were analyzed successfully in 20 worms. Fifteen worms showed the F. gigantica type and five (including one worm from a patient) had mixed ITS2 sequences of both F. gigantica and F. hepatica in the same worms, with additional heterogeneity within both ITS2 types. This study revealed the intermediate form of Fasciola coexisting with F. gigantica for the first time in Thailand.

Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses.

PubMed

Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu

2015-01-01

The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the hypothesis that wild ruminants could act as reservoirs for such pathogens, and subsequently be involved in the reintroduction of disease to livestock on neighbouring farms.

Praziquantel

MedlinePlus

... used to treat certain other worm infestations, including tapeworm (a type of worm that may attach to ... have ocular cysticercosis (infestation with a type of tapeworm that forms cysts in the eyes). Your doctor ...

The effect of cohabitation of Tubifex tubifex (Oligochaeta: Tubificidae) populations on infections to Myxobolus cerebralis (Myxozoa: Myxobolidae).

PubMed

Beauchamp, Katherine A; El-Matbouli, Mansour; Gay, Melanie; Georgiadis, Marios P; Nehring, R Barry; Hedrick, Ronald P

2006-01-01

The competitive interactions between susceptible and resistant Tubifex tubifex (Oligochaeta: Tubificidae) exposed to Myxobolus cerebralis (Myxozoa: Myxobolidae) infections were investigated in two laboratory trials. Competition was assessed by the total parasite production over the course of the trials in mixed and pure cultures of M. cerebralis exposed worms, and by the genetic analyses of worms from the control and experimental groups at the beginning and end of the experiments. Mixed cultures of resistant and susceptible worms showed a 70% reduction in production of parasites released when compared with pure cultures of susceptible worms. In studies with laboratory and field-collected oligochaetes the mixed cultures at the end of the cohabitation experiments were dominated by resistant Tubifex from lineage V (HB strain) this strain of Tubifex has a competitive advantage over worms from other lineages. The results of this study suggest that certain species of Tubifex may be dead-end hosts to M. cerebralis by absorbing or inactivating the parasite and may also show greater survival compared to susceptible oligochaetes in certain whirling disease enzootic habitats.

Annual Survey of Horsehair Worm Cysts in Northern Taiwan, with Notes on a Single Seasonal Infection Peak in Chironomid Larvae (Diptera: Chironomidae).

PubMed

Chiu, Ming-Chung; Huang, Chin-Gi; Wu, Wen-Jer; Shiao, Shiuh-Feng

2016-06-01

The life cycle of the freshwater horsehair worm typically includes a free-living phase (adult, egg, larva) and a multiple-host parasitic phase (aquatic paratenic host, terrestrial definitive host). Such a life cycle involving water and land can improve energy flow in riparian ecosystems; however, its temporal dynamics in nature have rarely been investigated. This study examined seasonal infection with cysts in larval Chironominae (Diptera: Chironomidae) in northern Taiwan. In the larval chironomids, cysts of 3 horsehair worm species were identified. The cysts of the dominant species were morphologically similar to those of Chordodes formosanus. Infection with these cysts increased suddenly and peaked 2 mo after the reproductive season of the adult horsehair worms. Although adult C. formosanus emerged several times in a year, only 1 distinct infection peak was detected in September in the chironomid larvae. Compared with the subfamily Chironominae, samples from the subfamilies Tanypodinae and Orthocladiinae were less parasitized. This indicates that the feeding behavior of the chironomid host likely affects horsehair worm cyst infections; however, bioconcentration in predatory chironomids was not detected.

Influence of temperature and substrate on infection rate, triactinomyxon production, and release duration from eastern tubifex worms infected with Myxobolus cerebralis

USGS Publications Warehouse

Waldrop, Thomas; Blazer, Vicki; Smith, David; Schill, Bane; Densmore, Christine; Schill, B.; Waldrop, T.; Blazer, V.

1999-01-01

Salmonid whirling disease is caused by Myxobolus cerebralis, a metazoan parasite with a two host life cycle involving salmonid fish a an aquatic oligochaete, Tubifex tubifex (Wolf, Markiw and Hiltunen, 1986). Whirling disease has been reported in 22 U.S. states with the greatest losses occurring in the salmonid fisheries of western and Midwestern states. Although whirling disease is endemic in the eastern United States, serious documented losses to wild populations have not been reported. Two high priority research needs identified in 1996 were a better understanding of how worm and parasite populations might differ from different geographic areas and how environmental factors affect the various stages of whirling disease. To begin to address these research needs we established "eastern" populations of worms, parasite and fish hosts. This abstract will present data on the effects of temperature and substrate upon eastern T. tubifex worms infected with an eastern isolate of M. cerebralis. The influences of these abiotic factors upon the ability to infect the worms and subsequently their ability to produce waterborne triactinomyxons.

WormBase 2014: new views of curated biology

PubMed Central

Harris, Todd W.; Baran, Joachim; Bieri, Tamberlyn; Cabunoc, Abigail; Chan, Juancarlos; Chen, Wen J.; Davis, Paul; Done, James; Grove, Christian; Howe, Kevin; Kishore, Ranjana; Lee, Raymond; Li, Yuling; Muller, Hans-Michael; Nakamura, Cecilia; Ozersky, Philip; Paulini, Michael; Raciti, Daniela; Schindelman, Gary; Tuli, Mary Ann; Auken, Kimberly Van; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Wong, J. D.; Yook, Karen; Schedl, Tim; Hodgkin, Jonathan; Berriman, Matthew; Kersey, Paul; Spieth, John; Stein, Lincoln; Sternberg, Paul W.

2014-01-01

WormBase (http://www.wormbase.org/) is a highly curated resource dedicated to supporting research using the model organism Caenorhabditis elegans. With an electronic history predating the World Wide Web, WormBase contains information ranging from the sequence and phenotype of individual alleles to genome-wide studies generated using next-generation sequencing technologies. In recent years, we have expanded the contents to include data on additional nematodes of agricultural and medical significance, bringing the knowledge of C. elegans to bear on these systems and providing support for underserved research communities. Manual curation of the primary literature remains a central focus of the WormBase project, providing users with reliable, up-to-date and highly cross-linked information. In this update, we describe efforts to organize the original atomized and highly contextualized curated data into integrated syntheses of discrete biological topics. Next, we discuss our experiences coping with the vast increase in available genome sequences made possible through next-generation sequencing platforms. Finally, we describe some of the features and tools of the new WormBase Web site that help users better find and explore data of interest. PMID:24194605

Vermicomposting of sewage sludge: a new technology for Mexico.

PubMed

Vigueros, L Cardosa; Ramírez Camperos, E

2002-01-01

In Mexico 31% of the treatment plants have a flow less than 60 l/s. This study offers a simple and economical alternative through vermicomposting to resolve the management of sewage sludge and water hyacinth for these small treatment plants. This study was developed with laboratory and pilot scale systems. In the laboratory Eisenia foetida survival was quantified. They were fed three doses of sludge and water hyacinth and different percentages of humidity were applied. The production of worm cocoons was quantified as biomass production and the reduction in the TV/STS ratio as an indicator of stability. To install the pilot system the mixture with the highest cocoon production was chosen. In the pilot test the effect of the worm population density on the waste degradation was observed, the experiment was divided into five modules, four with densities from 2.5 to 15 kg/m2 and one module without worms that served as a blank test. the best mixture was 70% sewage sludge and 30% water hyacinth, with 80% humidity and an average production of 298 cocoons/kg of vermicompost. There were no significant differences in the TVS/TS reduction between the different modules with worms, but in the blank test module there was no reduction. The Type A vermicompost obtained, with non-restricted use, 900 fecal coliforms NMP/g, 0.0 helminth ova/g, highly organic (60% M.O.), high concentration of total nitrogen (2.5%), phosphorus (0.96%) and cationic exchange capacity (60.2 meq/100 g), which indicates that soil fertility would increase if used in agriculture.

Phenotypic and genotypic analysis of benzimidazole resistance in the ovine parasite Nematodirus battus.

PubMed

Morrison, Alison A; Mitchell, Sian; Mearns, Rebecca; Richards, Iain; Matthews, Jacqui B; Bartley, David J

2014-12-09

Benzimidazole resistance is common amongst many ovine trichostrongylid nematodes species globally. Although anthelmintics have been used for over half a century in some areas of the world for the control of Nematodirus battus, resistance has never been detected. Veterinary investigations conducted in 2010 demonstrated reduced efficacy in a flock that had been treated previously with fenbendazole (FBZ), suggesting probable resistance in N. battus. Infective larvae (L3; designated MNba2) were generated from the original material to conduct a controlled efficacy test (CET). Faecal egg counts showed an average of 37% reduction in the FBZ treated group 7 days post treatment compared to the untreated lambs. Average worm burden results showed no reduction after FBZ treatment compared to the untreated group (3850 and 3850 worms respectively). A molecular assay to assess the frequency of the commonly associated single nucleotide polymorphisms (SNP) in the β-tubulin isotype 1 gene, F200Y and E198A, was developed. Larval genotypes were predominantly homozygous resistant at codon 200 SNP, ranging from 56%-83% and remained stable at 70% for adult worm populations taken from treated and control lambs in the CET. Only susceptible genotypes were found at codon 198. The allele frequency for F200Y ranged between 80-83% in adult worms taken from the CET from treated and control lambs. The results confirmed initial findings and demonstrated the first report of FBZ resistance in N. battus whilst providing evidence that the P200 point mutation in the β-tubulin isotype 1 gene is a potential mechanism of resistance in the species.

Genetic markers for the identification and characterization of Opisthorchis viverrini, a medically important food borne trematode in Southeast Asia.

PubMed

Saijuntha, Weerachai; Sithithaworn, Paiboon; Wongkham, Sopit; Laha, Thewarach; Pipitgool, Vichit; Petney, Trevor N; Andrews, Ross H

2006-12-01

The liver fluke, Opisthorchis viverrini, is one of the major food borne trematodes in Southeast Asia, where infection causes hepatobiliary disease and subsequent development of cholangiocarcinoma. In Thailand, O. viverrini is most prevalent in the northeast where there is marked regional variation in the rate of infection in humans at provincial, district and village levels. To date, the roles of genetic variation of O. viverrini on this observed variability in infection, transmission and associated disease are not known. We have applied multilocus enzyme electrophoresis (MEE), specifically allozyme electrophoresis, to isolates of O. viverrini from Thailand and Laos to establish genetic markers to examine its systematics and population structure. Forty-six enzymes commonly found useful for genetic characterisation in parasitic helminths were screened, and of these, 33 enzymes gave sufficient staining and resolution to act as potential genetic markers. Sixteen enzymes were monomorphic and 17 enzymes were polymorphic in the pools of worms examined. Whether they are indicative of different enzyme loci, heterozygosity or unique genotypes within the pools of worms examined remains to be determined. Preliminary investigations examining five individual worms at enzyme loci where pools of worms showed multiple bands have confirmed the diagnostic value of the enzyme loci established as well as providing evidence of potential population sub structuring and heterozygosity. For the first time, we have established at least 17 enzymes that provide the basis to undertake comprehensive genetic analyses of the systematics and population structure of O. viverrini, a medically important food borne trematode in Southeast Asia.

In vivo effect of single oral dose of artemether against early juvenile stages of Schistosoma mansoni Egyptian strain.

PubMed

El-Beshbishi, Samar N; Taman, Amira; El-Malky, Mohamed; Azab, Manar S; El-Hawary, Amira K; El-Tantawy, Dina A

2013-10-01

The current treatment and control of schistosomiasis, rely on a single drug, praziquantel, although, it has minor activity against juvenile stages of the parasite. Studies have shown that artemether (ART) exhibits effects against juveniles of Schistosoma mansoni Liberian and Puerto Rican strains, Schistosoma japonicum and Schistosoma haematobium. Aiming to assess the in vivo activity of single oral dose of ART against early juvenile stages of S. mansoni Egyptian strain, this study was established. Mice were treated with ART (400 mg/kg) at two time points evenly spaced over the period of larval development (7 and 21 days post-infection; pi), and a third treatment point (day 49 pi) was included to elucidate when susceptibility decreases. Administration of ART on day 7 pi reduced the total worm burden by 85.94%. The greatest reductions were seen when treatment was given on day 21 pi, with total and female worm burden reductions of 91.52% and 90.57%, respectively, and cessation of oviposition. Similar dose given on day 49 pi reduced total worm burden by 55.17% and female worm burden by 66.51%. Moreover, it induced significant reduction in the tissue egg load and significant alterations in the oogram pattern with decreased immature eggs and increased dead eggs. Antipathological activities were evident in significant reductions in granulomata count and diameter. In conclusion, ART exhibits major in vivo schistosomicidal effects against the early larval migratory stages of S. mansoni Egyptian strain, mainly the 21-day old schistosomula, hence preventing disease progression and morbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

Antischistosomal activity of ginger (Zingiber officinale) against Schistosoma mansoni harbored in C57 mice.

PubMed

Mostafa, Osama M S; Eid, Refaat A; Adly, Mohamed A

2011-08-01

The repeated chemotherapy of schistosomiasis has resulted in the emergence of drug-resistant schistosome strains. The development of such resistance has drawn the attention of many authors to alternative drugs. Many medicinal plants were studied to investigate their antischistosomal potency. The present work aimed to evaluate antischistosomal activity of crude aqueous extract of ginger against Schistosoma mansoni. Sixteen mice of C57 strain were exposed to 100 ± 10 cercariae per mouse by the tail immersion method; the mice were divided into two groups: untreated group and ginger-treated one. All mice were sacrificed at the end of 10th week post-infection. Worm recovery and egg counting in the hepatic tissues and faeces were determined. Surface topography of the recovered worms was studied by scanning electron microscopy. Histopathological examination of liver and intestine was done using routine histological procedures. The worm burden and the egg density in liver and faeces of mice treated with ginger were fewer than in non-treated ones. Scanning electron microscopical examination revealed that male worms recovered from mice treated with ginger lost their normal surface architecture, since its surface showed partial loss of tubercles' spines, extensive erosion in inter-tubercle tegumental regions and numerous small blebs around tubercles. Histopathological data indicated a reduction in the number and size of granulomatous inflammatory infiltrations in the liver and intestine of treated mice compared to non-treated mice. The results of the present work suggested that ginger has antischistosomal activities and provided a basis for subsequent experimental and clinical trials.

Lectins with anti-HIV activity: a review.

PubMed

Akkouh, Ouafae; Ng, Tzi Bun; Singh, Senjam Sunil; Yin, Cuiming; Dan, Xiuli; Chan, Yau Sang; Pan, Wenliang; Cheung, Randy Chi Fai

2015-01-06

Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin) lectin, concanavalin A, Galanthus nivalis (snowdrop) agglutinin-related lectins, Musa acuminata (banana) lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus). The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed.

Morphological and molecular characteristics of Malayfilaria sofiani Uni, Mat Udin & Takaoka n. g., n. sp. (Nematoda: Filarioidea) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia.

PubMed

Uni, Shigehiko; Mat Udin, Ahmad Syihan; Agatsuma, Takeshi; Saijuntha, Weerachai; Junker, Kerstin; Ramli, Rosli; Omar, Hasmahzaiti; Lim, Yvonne Ai-Lian; Sivanandam, Sinnadurai; Lefoulon, Emilie; Martin, Coralie; Belabut, Daicus Martin; Kasim, Saharul; Abdullah Halim, Muhammad Rasul; Zainuri, Nur Afiqah; Bhassu, Subha; Fukuda, Masako; Matsubayashi, Makoto; Harada, Masashi; Low, Van Lun; Chen, Chee Dhang; Suganuma, Narifumi; Hashim, Rosli; Takaoka, Hiroyuki; Azirun, Mohd Sofian

2017-04-20

The filarial nematodes Wuchereria bancrofti (Cobbold, 1877), Brugia malayi (Brug, 1927) and B. timori Partono, Purnomo, Dennis, Atmosoedjono, Oemijati & Cross, 1977 cause lymphatic diseases in humans in the tropics, while B. pahangi (Buckley & Edeson, 1956) infects carnivores and causes zoonotic diseases in humans in Malaysia. Wuchereria bancrofti, W. kalimantani Palmieri, Pulnomo, Dennis & Marwoto, 1980 and six out of ten Brugia spp. have been described from Australia, Southeast Asia, Sri Lanka and India. However, the origin and evolution of the species in the Wuchereria-Brugia clade remain unclear. While investigating the diversity of filarial parasites in Malaysia, we discovered an undescribed species in the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia). We examined 81 common treeshrews from 14 areas in nine states and the Federal Territory of Peninsular Malaysia for filarial parasites. Once any filariae that were found had been isolated, we examined their morphological characteristics and determined the partial sequences of their mitochondrial cytochrome c oxidase subunit 1 (cox1) and 12S rRNA genes. Polymerase chain reaction (PCR) products of the internal transcribed spacer 1 (ITS1) region were then cloned into the pGEM-T vector, and the recombinant plasmids were used as templates for sequencing. Malayfilaria sofiani Uni, Mat Udin & Takaoka, n. g., n. sp. is described based on the morphological characteristics of adults and microfilariae found in common treeshrews from Jeram Pasu, Kelantan, Malaysia. The Kimura 2-parameter distance between the cox1 gene sequences of the new species and W. bancrofti was 11.8%. Based on the three gene sequences, the new species forms a monophyletic clade with W. bancrofti and Brugia spp. The adult parasites were found in tissues surrounding the lymph nodes of the neck of common treeshrews. The newly described species appears most closely related to Wuchereria spp. and Brugia spp., but differs from these in several morphological characteristics. Molecular analyses based on the cox1 and 12S rRNA genes and the ITS1 region indicated that this species differs from both W. bancrofti and Brugia spp. at the genus level. We thus propose a new genus, Malayfilaria, along with the new species M. sofiani.

Characterization and Function of the First Antibiotic Isolated from a Vent Organism: The Extremophile Metazoan Alvinella pompejana

PubMed Central

Tasiemski, Aurélie; Jung, Sascha; Boidin-Wichlacz, Céline; Jollivet, Didier; Cuvillier-Hot, Virginie; Pradillon, Florence; Vetriani, Costantino; Hecht, Oliver; Sönnichsen, Frank D.; Gelhaus, Christoph; Hung, Chien-Wen; Tholey, Andreas; Leippe, Matthias; Grötzinger, Joachim; Gaill, Françoise

2014-01-01

The emblematic hydrothermal worm Alvinella pompejana is one of the most thermo tolerant animal known on Earth. It relies on a symbiotic association offering a unique opportunity to discover biochemical adaptations that allow animals to thrive in such a hostile habitat. Here, by studying the Pompeii worm, we report on the discovery of the first antibiotic peptide from a deep-sea organism, namely alvinellacin. After purification and peptide sequencing, both the gene and the peptide tertiary structures were elucidated. As epibionts are not cultivated so far and because of lethal decompression effects upon Alvinella sampling, we developed shipboard biological assays to demonstrate that in addition to act in the first line of defense against microbial invasion, alvinellacin shapes and controls the worm's epibiotic microflora. Our results provide insights into the nature of an abyssal antimicrobial peptide (AMP) and into the manner in which an extremophile eukaryote uses it to interact with the particular microbial community of the hydrothermal vent ecosystem. Unlike earlier studies done on hydrothermal vents that all focused on the microbial side of the symbiosis, our work gives a view of this interaction from the host side. PMID:24776651

Helminthic therapy: using worms to treat immune-mediated disease.

PubMed

Elliott, David E; Weinstock, Joel V

2009-01-01

There is an epidemic of immune-mediated disease in highly-developed industrialized countries. Such diseases, like inflammatory bowel disease, multiple sclerosis and asthma increase in prevalence as populations adopt modern hygienic practices. These practices prevent exposure to parasitic worms (helminths). Epidemiologic studies suggest that people who carry helminths have less immune-mediated disease. Mice colonized with helminths are protected from disease in models of colitis, encephalitis, Type 1 diabetes and asthma. Clinical trials show that exposure to helminths reduce disease activity in patients with ulcerative colitis or Crohn's disease. This chapter reviews some of the work showing that colonization with helminths alters immune responses, against dysregulated inflammation. These helminth-host immune interactions have potentially important implications for the treatment of immune-mediated diseases.

Emulation of the Active Immune Response in a Computer Network

DTIC Science & Technology

2009-01-15

the Code Red worm propagated faster than the Melissa virus in 1999 and much faster than Morris’ worm in 1988. In the case of the Code Red worm, only...report to AFRL on contract #30602-01-0509, Binghamton NY, 2002, 2. Skormin, V.A., Delgado-Frias, J.G., McGee, D.L., Giordano , J.V., Popyack, L.J...V., Delgado-Frias J., McGee D., Giordano J., Popyack L.. Tarakanov A., "BASIS: A Biological Approach to System Information Security," ^2

Human Gongylonema pulchrum Infection: Esophageal Symptoms and Need for Prolonged Albendazole Therapy.

PubMed

Libertin, Claudia R; Reza, Mohammed; Peterson, Joy H; Lewis, Jason; Hata, D Jane

2017-04-01

AbstractWe describe a case of human infection with Gongylonema pulchrum acquired in southeast Georgia. The patient presented with intermittent yet persistent nausea and vomiting for months. This case describes the need for extraction of worms on two occasions each followed by courses of albendazole treatment. Gongylonema pulchrum infections with high worm burden may relapse after extraction of the worm and a 3-day short course of albendazole therapy. Longer courses of albendazole may be indicated in selected circumstances.

Hydrolytic degradation of poly(ethylene oxide)-block-polycaprolactone worm micelles.

PubMed

Geng, Yan; Discher, Dennis E

2005-09-21

Spherical micelles and nanoparticles made with degradable polymers have been of great interest for therapeutic application, but degradation-induced changes in a spherical morphology can be subtle and mechanism/kinetics appears poorly understood. Here, we report the first preparation of giant and flexible worm micelles self-assembled from degradable copolymer poly(ethylene oxide)-block-polycaprolactone. Such worm micelles spontaneously shorten to generate spherical micelles, triggered by polycaprolactone hydrolysis, with distinct mechanism and kinetics from that which occurs in bulk material.

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

7 CFR 51.3145 - U.S. Fancy.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., broken skins which are not healed, worms, worm holes, and free from injury caused by bruises, growth cracks, hail, sunburn, sprayburn, scab, bacterial spot, scale, split pit, scars, russeting, other disease...

Elicitation of dopaminergic features of Parkinson's disease in C. elegans by monocrotophos, an organophosphorous insecticide.

PubMed

Ali, Shaheen Jafri; Rajini, Padmanabhan Sharda

2012-12-01

Positive correlations have been suggested between usage of pesticides and the incidence of Parkinson's disease (PD) through epidemiological as well as few experimental evidences. Organophosphorus insecticides (OPI), which are extensively used in agricultural and household insect control, have been the subject of increasing concern in the past decades due to their neurotoxic potential. However, very few studies have demonstrated the potentials of OPI to induce features of PD in model organisms. In the present study, Caenorhabditis elegans was selected as the model organism to evaluate the potential of monocrotophos (MCP), an OPI, to elicit dopaminergic features of Parkinson's disease in terms of dopamine content, basic movement and integrity of dopaminergic neurons along with its effect on acetylcholinesterase (AChE) activity and life span. All the responses elicited by MCP were compared with that elicited by 1-methyl-4-phenyl- 1, 2, 3, 6-tetrahydropyridine (MPTP) in both N2 and BZ555 worms. N2 worms were exposed to varying concentrations of MCP (50, 100 and 200 μM) or MPTP (200, 300 and 400 μM) for 48 hours and locomotory rate, as measured by the number of body bends made in 20 seconds, was enumerated. Worms subjected to the same dose paradigms were also analyzed for the dopamine content by HPLC. The results indicated a significant reduction in the dopamine levels in the worms that were treated with MCP/MPTP and this correlated with the changes in locomotion compared to untreated worms. Worms treated with MCP also exhibited significant reduction in AChE activity. Both MPTP and MCP caused a marked reduction in life span in the worms. Transgenic worms (BZ555, which has GFP tagged to its 8 dopaminergic neurons) exposed to MCP and MPTP at the above concentrations showed a dose-dependent reduction in the number of green pixels in CEP and ADE neurons which also correlated with the neurodegeneration as visualized by decreased fluorescence in photomicrographs. Taken together, our data demonstrate that low levels of MCP elicits dopaminergic features of PD in C. elegans.

Arrested development of abomasal trichostrongylid nematodes in lambs in a steppe environment (North-Eastern Algeria)

PubMed Central

Meradi, Salah; Cabaret, Jacques; Bentounsi, Bourhane

2016-01-01

Arrested development of abomasal trichostrongylid nematodes was studied in 30 permanent grazing lambs on a large farm in the North-East of Algeria. The steppe climate has cold winters and hot and dry summers. The lambs were monitored monthly for gastrointestinal nematodes using nematode faecal egg counts, from February 2008 to February 2009. Every 2 months, two of the original 30 permanent lambs were necropsied after being held in pens for three weeks so that recently ingested infective larvae could develop into adults. The highest percentage of fourth stage larvae (L4), reaching 48% of the total worm burden, was recorded in abomasal contents in June. Teladorsagia and other Ostertagiinae constituted the highest percentage of L4 larvae (71%), whereas the percentage of Trichostrongylus (17.4%) or Haemonchus (11.6%) remained low. The dynamics of infection observed here (highest faecal egg count in August) and the stage composition of worm burden (highest percentage of L4 in June) provide strong evidence that arrested development had occurred. PMID:27608531