Molecular detection of Setaria tundra (Nematoda: Filarioidea and an unidentified filarial species in mosquitoes in Germany

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Czajka Christina

2012-01-01

Full Text Available Abstract Background Knowledge of the potential vector role of Culicidae mosquitoes in Germany is very scanty, and until recently it was generally assumed that they are not involved in the transmission of anthroponotic or zoonotic pathogens in this country. However, anticipated changes in the course of global warming and globalization may alter their status. Methods We conducted a molecular mass screening of mosquitoes for filarial parasites using mitochondrial 12S rRNA-based real-time PCR. Results No parasites causing disease in humans such as Dirofilaria spp. were detected in about 83,000 mosquitoes tested, which had been collected in 2009 and 2010 in 16 locations throughout Germany. However, minimum infection rates of up to 24 per 1000 mosquitoes were revealed, which could be attributed to mosquito infection with Setaria tundra and a yet unidentified second parasite. Setaria tundra was found to be widespread in southern Germany in various mosquito species, except Culex spp. In contrast, the unidentified filarial species was exclusively found in Culex spp. in northern Baden-Württemberg, and is likely to be a bird parasite. Conclusions Although dirofilariasis appears to be emerging and spreading in Europe, the absence of Dirofilaria spp. or other zoonotic filariae in our sample allows the conclusion that the risk of autochthonous infection in Germany is still very low. Potential vectors of S. tundra in Germany are Ochlerotatus sticticus, Oc. cantans, Aedes vexans and Anopheles claviger. Technically, the synergism between entomologists, virologists and parasitologists, combined with state-of-the-art methods allows a very efficient near-real-time monitoring of a wide spectrum of both human and veterinary pathogens, including new distribution records of parasite species and the incrimination of their potential vectors.

Black flies (Diptera : Simuliidae attracted to humans and water buffalos and natural infections with filarial larvae, probably Onchocerca sp., in northern Thailand

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Takaoka H.

2003-03-01

Full Text Available Several Simulium species were investigated as to their biting habits and natural infections with filarial larvae at Ban Pan Fan, Chiang Mai Province, in northern Thailand. Female adults flies landing on or flighting around a human and a water buffalo were collected during the daytime from 06.00 to 19.00 hours on 22 June 2001. As a result, 217 S. nodosum, 86 S. asakoae and two S. nigrogilvum were obtained from a human attractant, and 416 S. nodosum, 25 S. nakhonense, 16 S. asakoae, four 5. fenestratum and two S. nigrogilvum, from a water buffalo. The blood-feeding was confirmed only for S. nodosum and S. nigrogilvum on humans, and for S. nodosum and S. nakhonense on water buffalos. Dissections of these simuliids showed that S. nodosum was naturally infected with developing filarial larvae. Two types of microfilariae were distinguished but only one type of infective larvae. These larvae resembled Onchocerca suzukii, a parasite from a wild Japanese bovid, suggesting that an unknown Onchocerca species from ruminants was transmitted in Thailand. Infection rates with all stages of larvae and third-stage larvae were 2.3 % (14/608 and 1 .0 % (6/608, respectively. This is the first report of natural infections of black flies with Onchocerca larvae in Southeast Asia, and the involved black fly species is shown to be not only anthropophilic but also zoophilic in this region.

Attempts to Image the Early Inflammatory Response during Infection with the Lymphatic Filarial Nematode Brugia pahangi in a Mouse Model.

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Elmarie Myburgh

Full Text Available Helminth parasites remain a major constraint upon human health and well-being in many parts of the world. Treatment of these infections relies upon a very small number of therapeutics, most of which were originally developed for use in animal health. A lack of high throughput screening systems, together with limitations of available animal models, has restricted the development of novel chemotherapeutics. This is particularly so for filarial nematodes, which are long-lived parasites with a complex cycle of development. In this paper, we describe attempts to visualise the immune response elicited by filarial parasites in infected mice using a non-invasive bioluminescence imaging reagent, luminol, our aim being to determine whether such a model could be developed to discriminate between live and dead worms for in vivo compound screening. We show that while imaging can detect the immune response elicited by early stages of infection with L3, it was unable to detect the presence of adult worms or, indeed, later stages of infection with L3, despite the presence of worms within the lymphatic system of infected animals. In the future, more specific reagents that detect secreted products of adult worms may be required for developing screens based upon live imaging of infected animals.

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

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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.

Polyanhydride Nanoparticle Delivery Platform Dramatically Enhances Killing of Filarial Worms.

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Andrea M Binnebose

Full Text Available Filarial diseases represent a significant social and economic burden to over 120 million people worldwide and are caused by endoparasites that require the presence of symbiotic bacteria of the genus Wolbachia for fertility and viability of the host parasite. Targeting Wolbachia for elimination is a therapeutic approach that shows promise in the treatment of onchocerciasis and lymphatic filariasis. Here we demonstrate the use of a biodegradable polyanhydride nanoparticle-based platform for the co-delivery of the antibiotic doxycycline with the antiparasitic drug, ivermectin, to reduce microfilarial burden and rapidly kill adult worms. When doxycycline and ivermectin were co-delivered within polyanhydride nanoparticles, effective killing of adult female Brugia malayi filarial worms was achieved with approximately 4,000-fold reduction in the amount of drug used. Additionally the time to death of the macrofilaria was also significantly reduced (five-fold when the anti-filarial drug cocktail was delivered within polyanhydride nanoparticles. We hypothesize that the mechanism behind this dramatically enhanced killing of the macrofilaria is the ability of the polyanhydride nanoparticles to behave as a Trojan horse and penetrate the cuticle, bypassing excretory pumps of B. malayi, and effectively deliver drug directly to both the worm and Wolbachia at high enough microenvironmental concentrations to cause death. These provocative findings may have significant consequences for the reduction in the amount of drug and the length of treatment required for filarial infections in terms of patient compliance and reduced cost of treatment.

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

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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

Filarial excretory-secretory products induce human monocytes to produce lymphangiogenic mediators.

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Tiffany Weinkopff

2014-07-01

Full Text Available The nematodes Wuchereria bancrofti and Brugia spp. infect over 120 million people worldwide, causing lymphedema, elephantiasis and hydrocele, collectively known as lymphatic filariasis. Most infected individuals appear to be asymptomatic, but many exhibit sub-clinical manifestations including the lymphangiectasia that likely contributes to the development of lymphedema and elephantiasis. As adult worm excretory-secretory products (ES do not directly activate lymphatic endothelial cells (LEC, we investigated the role of monocyte/macrophage-derived soluble factors in the development of filarial lymphatic pathology. We analyzed the production of IL-8, IL-6 and VEGF-A by peripheral blood mononuclear cells (PBMC from naïve donors following stimulation with filarial ES products. ES-stimulated PBMCs produced significantly more IL-8, IL-6 and VEGF-A compared to cells cultured in medium alone; CD14(+ monocytes appear to be the primary producers of IL-8 and VEGF-A, but not IL-6. Furthermore, IL-8, IL-6 and VEGF-A induced in vitro tubule formation in LEC Matrigel cultures. Matrigel plugs supplemented with IL-8, IL-6, VEGF-A, or with supernatants from ES-stimulated PBMCs and implanted in vivo stimulated lymphangiogenesis. Collectively, these data support the hypothesis that monocytes/macrophages exposed to filarial ES products may modulate lymphatic function through the secretion of soluble factors that stimulate the vessel growth associated with the pathogenesis of filarial disease.

Nuclear techniques in the study of parasitic infections

International Nuclear Information System (INIS)

1982-01-01

Out of 57 papers published, 47 fall within the INIS subject scope. Seven main topics were covered: resistance to infections with protozoan parasites; resistance to infections with African trypanosomes and helminths of ruminant animals; resistance to infections with filarial parasites and schistosomes; pathology of parasitic infections; epidemiology and diagnosis of parasitic infections; physiology and biochemistry of parasitic organisms; pharmacodynamics of anti-parasitic agents

ANTIGENAEMIA AS AN INDICATOR OF FILARIAL ENDEMICITY

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F. Partono

2012-09-01

Full Text Available This is a report of 1 -year evaluation of chemotherapeutic intervention in an area of Indonesia endemic for lymphatic filariasis. Control measures were initiated in 1977 by parasite control, informal health educa­tion, and community participation at the village level, well in accord with the WHO-concept of health for all. Diethylcarbamazine (DEC was mass distributed in 1977 and 1988, and selectively distributed in 1978, 1979, 1981, and 1982 to those who were micro-filaraemic prior to DEC treatments, those with a history of adenoly mphangitis over the previous one year period, and to all new comers. In addition, each villager with acute symptoms of adenolymphangitis was immediately treated with a single course of 300 mg DEC for 10 days. No intervention measures were taken between 1982 to 1988, and no attempt was taken to control the vector or to restrict movement between controlled and uncontrolled areas during the whole studies. With these measures, the microfilaria (mf rate decreased from 30% to 0%, the adenolymphangitis rate from 46% to 11%, and the elephantiasis rate from 35% to 3%. The abatement of acute and chronic filarial symptoms over the study period and the disappearance of microfilaremia in the community are pointing towards the possibility of eradicating the partasite from the community. To test this hypothesis, serum samples were tested for circulating filarial antigen by a two-site antigen capture assay employing anti-phosphorylcholine monoclonal antibodies. There was a sharp fall in circulating antigenaemia, demonstrating that infection has either been eliminated from nearly all villagers, or that intensity of infection is now undetectably low. We feel that antigenaemia can be used as an indicator of filarial endemicity.

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

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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.

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

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

1993-01-01

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-γ 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 exhibited 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

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

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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.

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

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Hiruni Harischandra

2018-04-01

Full Text Available 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.

Kinetic Characterisation of Phosphofructokinase Purified from Setaria cervi: A Bovine Filarial Parasite

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Bechan Sharma

2011-01-01

Full Text Available Phosphofructokinase (PFK, a regulatory enzyme in glycolytic pathway, has been purified to electrophoretic homogeneity from adult female Setaria cervi and partially characterized. For this enzyme, the Lineweaver-Burk's double reciprocal plots of initial rates and D-fructose-6-phosphate (F-6-P or Mg-ATP concentrations for varying values of cosubstrate concentration gave intersecting lines indicating that Km values for F-6-P (1.05 mM and ATP (3 μM were independent of each other. S. cervi PFK, when assayed at inhibitory concentration of ATP (>0.1 mM, exhibited sigmoidal behavior towards binding with F-6-P with a Hill coefficient (n value equal to 1.8 and 1.7 at 1.0 and 0.33 mM ATP, respectively. D-fructose-1,6-diphosphate (FDP competitively inhibited the filarial enzyme: Ki and Hill coefficient values being 0.18 μM and 2.0, respectively. Phosphoenolpyruvate (PEP also inhibited the enzyme competitively with the Ki value equal to 0.8 mM. The Hill coefficient values (>1.5 for F-6-P (at inhibitory concentration of ATP and FDP suggested its positive cooperative kinetics towards F-6-P and FDP, showing presence of more than one binding sites for these molecules in enzyme protein and allosteric nature of the filarial enzyme. The product inhibition studies gave us the only compatible mechanism of random addition process with a probable orientation of substrates and products on the enzyme surface.

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

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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.

A Clinico- Epidemiological Study Of Filarial Related Orthopaedic Manifestations

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Patond K.R

1992-01-01

Full Text Available An epidemiological study was undertaken to study the incidence and distribution of orthopaedic manifestations of filariasis in an endemic area. A total of 207 cases were clinically examined and investigated. Patients were divided into three groups , viz., Group A: Orthopaedic manifestations with no history of filariasis . Group B: Orthopaedic manifestations with history of filariasis such as microfilaraemia or filarial fevers etc., Group C: Orthopaedic manifestations with chronic manifestations such as elephantiasis, hydrocele etc. To confirm filarial etiology, all the cases were examined for the presence of filarial antibody by indirect ELISA using wuchereda bancrofti microfilarial excretory- secretary antigen (wd Mf ESAg . A total of 61 of 102 patients of Group A, 14 of 21 patients of group B, and 73 of 84 patients of Group C were positive for filarial antibody. This study showed the prevalence of filarial antibody in about 71.4% of various orthopaedic manifestations.

Seasonal and diurnal biting activities and zoonotic filarial infections of two Simulium species (Diptera: Simuliidae in northern Thailand

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Ishii Y.

2008-06-01

Full Text Available Seasonal and daily biting activity patterns, and natural filarial infections of adult black flies attracted to human bait were investigated at Ban Pang Faen, a rural area in Chiang Mai Province in northern Thailand. Collections were carried out twice a month from 06-00 to 18-00 hours from January 2005 to February 2006. Among ten Simulium species collected, S. nodosum and S. asakoae were predominant occupying 57.3% and 37.2% of the total 16, 553 females, respectively. These two predominant species showed different patterns in seasonal abundance: majority of S. nodosum (86.7% were collected in hot season (from mid February to mid May, while most of S. asakoae (74.5% were collected in rainy season (from mid May to mid October. For the daily biting activity, S. nodosum had two patterns: the main one was unimodal with a peak from 17-00 to 18-00, and the other was bimodal and had the major peak from 16-00 to 18-00 and the minor one from 07-00 to 09-00. The pattern of S. asakoae was mostly unimodal with a peak from 06-00 to 10-00. The filarial larvae found in S. nodosum and S. asakoae were morphologically different from each other. The short and thick infective larvae found in S. asakoae differed from all known filarial larvae; it is suggested that they might be a bird parasite, Splendidofilariinae or Lemdaninae. The infection of the mammophilic S. nodosum with large Onchocerca type infective larvae was confirmed in this area. Natural filarial infections were found in each month (except December in either S. nodosum or S. asakoae or in both. Monthly infection rates with all stages of larvae were 0.6-5.0% for S. nodosum, and 1.0-4.0% for S. asakoae. It is suggested that people in this village are exposed to the risk of infection with zoonotic filariae throughout the year.

Blood parasites in reptiles imported to Germany.

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Halla, Ursula; Ursula, Halla; Korbel, Rüdiger; Rüdiger, Korbel; Mutschmann, Frank; Frank, Mutschmann; Rinder, Monika; Monika, Rinder

2014-12-01

Though international trade is increasing, the significance of imported reptiles as carriers of pathogens with relevance to animal and human health is largely unknown. Reptiles imported to Germany were therefore investigated for blood parasites using light microscopy, and the detected parasites were morphologically characterized. Four hundred ten reptiles belonging to 17 species originating from 11 Asian, South American and African countries were included. Parasites were detected in 117 (29%) of individual reptiles and in 12 species. Haemococcidea (Haemogregarina, Hepatozoon, Schellackia) were found in 84% of snakes (Python regius, Corallus caninus), 20% of lizards (Acanthocercus atricollis, Agama agama, Kinyongia fischeri, Gekko gecko) and 50% of turtles (Pelusios castaneus). Infections with Hematozoea (Plasmodium, Sauroplasma) were detected in 14% of lizards (Acanthocercus atricollis, Agama agama, Agama mwanzae, K. fischeri, Furcifer pardalis, Xenagama batillifera, Acanthosaura capra, Physignathus cocincinus), while those with Kinetoplastea (Trypanosoma) were found in 9% of snakes (Python regius, Corallus caninus) and 25 % of lizards (K. fischeri, Acanthosaura capra, G. gecko). Nematoda including filarial larvae parasitized in 10% of lizards (Agama agama, Agama mwanzae, K. fischeri, Fu. pardalis, Physignathus cocincinus). Light microscopy mostly allowed diagnosis of the parasites' genus, while species identification was not possible because of limited morphological characteristics available for parasitic developmental stages. The investigation revealed a high percentage of imported reptiles being carriers of parasites while possible vectors and pathogenicity are largely unknown so far. The spreading of haemoparasites thus represents an incalculable risk for pet reptiles, native herpetofauna and even human beings.

Fitness Cost of Litomosoides sigmodontis Filarial Infection in Mite Vectors; Implications of Infected Haematophagous Arthropod Excretory Products in Host-Vector Interactions

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Adélaïde Nieguitsila

2013-01-01

Full Text Available Filariae are a leading cause of infections which are responsible for serious dermatological, ocular, and vascular lesions. Infective third stage larvae (L3 are transmitted through the bite of a haematophagous vector. Litomosoides sigmodontis is a well-established model of filariasis in the mouse, with the vector being the mite Ornithonyssus bacoti. The aim of the study was to analyse the filarial infection in mites to determine the consequences of filarial infection in the blood-feeding and the reproduction of mites as well as in the regulation of vector-induced inflammation in the mouse skin. Firstly, L3 are unevenly distributed throughout the host population and the majority of the population harbours a moderate infection (1 to 6 L3. Filarial infection does not significantly affect the probing delay for blood feeding. The number of released protonymphs is lower in infected mites but is not correlated with the L3 burden. Finally, induced excreted proteins from infected mites but not from uninfected mites stimulate TNF-α and the neutrophil-chemoattractant KC production by antigen-presenting cells (APCs. Altogether, these results describe the modification of the mite behavior under filarial infection and suggest that the immunomodulatory capacity of the mite may be modified by the presence of the parasite, hindering its defensive ability towards the vertebrate host.

Human and Animal Dirofilariasis: the Emergence of a Zoonotic Mosaic

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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

Colorimetric tests for diagnosis of filarial infection and vector surveillance using non-instrumented nucleic acid loop-mediated isothermal amplification (NINA-LAMP.

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Catherine B Poole

Full Text Available Accurate detection of filarial parasites in humans is essential for the implementation and evaluation of mass drug administration programs to control onchocerciasis and lymphatic filariasis. Determining the infection levels in vector populations is also important for assessing transmission, deciding when drug treatments may be terminated and for monitoring recrudescence. Immunological methods to detect infection in humans are available, however, cross-reactivity issues have been reported. Nucleic acid-based molecular assays offer high levels of specificity and sensitivity, and can be used to detect infection in both humans and vectors. In this study we developed loop-mediated isothermal amplification (LAMP tests to detect three different filarial DNAs in human and insect samples using pH sensitive dyes for enhanced visual detection of amplification. Furthermore, reactions were performed in a portable, non-instrumented nucleic acid amplification (NINA device that provides a stable heat source for LAMP. The efficacy of several strand displacing DNA polymerases were evaluated in combination with neutral red or phenol red dyes. Colorimetric NINA-LAMP assays targeting Brugia Hha I repeat, Onchocerca volvulus GST1a and Wuchereria bancrofti LDR each exhibit species-specificity and are also highly sensitive, detecting DNA equivalent to 1/10-1/5000th of one microfilaria. Reaction times varied depending on whether a single copy gene (70 minutes, O. volvulus or repetitive DNA (40 min, B. malayi and W. bancrofti was employed as a biomarker. The NINA heater can be used to detect multiple infections simultaneously. The accuracy, simplicity and versatility of the technology suggests that colorimetric NINA-LAMP assays are ideally suited for monitoring the success of filariasis control programs.

Paleoparasitology: the origin of human parasites

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Adauto Araujo

2013-09-01

Full Text Available Parasitism is composed by three subsystems: the parasite, the host, and the environment. There are no organisms that cannot be parasitized. The relationship between a parasite and its host species most of the time do not result in damage or disease to the host. However, in a parasitic disease the presence of a given parasite is always necessary, at least in a given moment of the infection. Some parasite species that infect humans were inherited from pre-hominids, and were shared with other phylogenetically close host species, but other parasite species were acquired from the environment as humans evolved. Human migration spread inherited parasites throughout the globe. To recover and trace the origin and evolution of infectious diseases, paleoparasitology was created. Paleoparasitology is the study of parasites in ancient material, which provided new information on the evolution, paleoepidemiology, ecology and phylogenetics of infectious diseases.

Limitations of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) for detection of filarial antigens in serum

International Nuclear Information System (INIS)

Hamilton, R.G.; Alexander, E.; Adkinson, N.F.

1984-01-01

The performance of the radioimmunoprecipitation polyethylene glycol assay (RIPEGA) was examined for quantitation of filarial antigens (Brugia malayi and Dirofilaria immitis) in serum from infected human and animal hosts and non-infected controls. Multiple PEG concentrations were employed to determine the level of non-specific binding (NSB) in non-exposed human sera (NEHS) containing no filarial antigen. The NSB observed when 3 different 125 I-labelled IgG antibodies were added to 26 NEHS varied 3-fold and was correlated significantly with total serum IgM (r = 0.80, P 2 fragment of the 125 I-labelled antibody was used, but the correlation of NSB with total serum IgM remained significant (r = 0.57, P < 0.01). The presence of rheumatoid factor in NEHS sera also significantly increased NSB by an average of 3-fold. These effects eliminated the assay's ability to detect in sera from infected hosts filarial antigen the presence of which could be readily demonstrated by an immunoradiometric assay. The RIPEGA's precision (intra-assay coefficient of variation (CV) = 21% at 35% Bsub(max)) and reproducibility (inter-assay CV = 29% at 35% Bsub(max)) are less satisfactory than many alternative immunoassays. (Auth.)

The "filarial dance" is not characteristic of filariasis: observations of "dancing megasperm" on high-resolution sonography in patients from nonendemic areas mimicking the filarial dance and a proposed mechanism for this phenomenon.

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Adejolu, Margaret; Sidhu, Paul S

2011-08-01

The objective of this series was to show that the sonographic appearance described as the "filarial dance" is not characteristic of filariasis but occurs in nonendemic areas as a manifestation of epididymal obstruction. An experienced observer documented cases after initial observation of the filarial dance in routine clinical practice using high-frequency linear array transducers. The filarial dance was described as excessive to-and-fro movement of echogenic particles within a prominent epididymis and graded 1 to 4 according to the extent and distribution of the abnormality. The country of birth, exposure to filarial infection or travel to a filarial-endemic area, previous scrotal surgery including vasectomy, any previous or current scrotal inflammatory disease, and any congenital testicular abnormalities were recorded. Over a 10-year period, sonographic appearances consistent with the filarial dance were observed in 18 patients (bilateral in 6). The mean patient age was 47.7 (range, 28-91) years. The abnormality was graded in the 24 affected testes as follows: grade 1, n = 3; grade 2, n = 8; grade 3, n = 8; and grade 4, n = 5. No patient had a history of filariasis or travel to an endemic area. Six of 18 patients (33.3%) had bilateral vasectomies; 5 (27.8%) had a history of epididymo-orchitis in the ipsilateral testis; 3 (16.7%) had previous scrotal surgery; and 4 (22.2%) had no relevant urologic history. We have described a sonographic appearance identical to the filarial dance in men with no history of filarial infection. Most had previous scrotal surgery or infection, suggesting that the filarial dance may not always be due to movement of filarial worms. The unifying condition in patients with filariasis and our patients is lymphatic obstruction, likely the underlying cause of the appearance in both groups.

[A case of human dirofilariasis (D. repens) of the spermatic cord].

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Fini, M; Perrone, A; Vagliani, G; Andreini, C; Salvi, G; Misuriello, G; Di Silverio, A

1992-01-01

A 52 year old man, living in the province of Trapani (Sicily), presented with right hydrocele and slight orchialgia. The patient underwent epididymectomy and resection of T. vaginalis. The "tunica" was involved by a granulomatous process, containing a parasite of genus Dirofilaria (D. repens). Dirofilaria repens is a filarial nematode. Dogs, foxes and cats are the definitive hosts and principal reservoirs of the parasite. In humans the parasite dies before reaching sexual maturity and the result is an inconspicuous granulomatous reaction in the subcutaneous tissue. S. Pampiglione et al. (Cattedra di Parassitologia Veterinaria dell'Università di Bologna-Italy) reported from 1971 more than 30 cases of human Dirofilariasis in Italy, suggesting that the parasite is able to migrate from the inoculation site to other districts (lung, eye etc.). The case is exceptional for the localization of the parasite (never reported) and can contribute to a better knowledge of the disease.

Brugia malayi excreted/secreted proteins at the host/parasite interface: stage- and gender-specific proteomic profiling.

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Sasisekhar Bennuru

Full Text Available Relatively little is known about the filarial proteins that interact with the human host. Although the filarial genome has recently been completed, protein profiles have been limited to only a few recombinants or purified proteins of interest. Here, we describe a large-scale proteomic analysis using microcapillary reverse-phase liquid chromatography-tandem-mass spectrometry to identify the excretory-secretory (ES products of the L3, L3 to L4 molting ES, adult male, adult female, and microfilarial stages of the filarial parasite Brugia malayi. The analysis of the ES products from adult male, adult female, microfilariae (Mf, L3, and molting L3 larvae identified 852 proteins. Annotation suggests that the functional and component distribution was very similar across each of the stages studied; however, the Mf contributed a higher proportion to the total number of identified proteins than the other stages. Of the 852 proteins identified in the ES, only 229 had previous confirmatory expressed sequence tags (ESTs in the available databases. Moreover, this analysis was able to confirm the presence of 274 "hypothetical" proteins inferred from gene prediction algorithms applied to the B. malayi (Bm genome. Not surprisingly, the majority (160/274 of these "hypothetical" proteins were predicted to be secreted by Signal IP and/or SecretomeP 2.0 analysis. Of major interest is the abundance of previously characterized immunomodulatory proteins such as ES-62 (leucyl aminopeptidase, MIF-1, SERPIN, glutathione peroxidase, and galectin in the ES of microfilariae (and Mf-containing adult females compared to the adult males. In addition, searching the ES protein spectra against the Wolbachia database resulted in the identification of 90 Wolbachia-specific proteins, most of which were metabolic enzymes that have not been shown to be immunogenic. This proteomic analysis extends our knowledge of the ES and provides insight into the host-parasite interaction.

Mansonella, including a Potential New Species, as Common Parasites in Children in Gabon.

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Gaël Mourembou

Full Text Available Like other tropical African countries, Gabon is afflicted by many parasitic diseases, including filariases such as loiasis and mansonellosis. This study aimed to assess the prevalence of these two filarial diseases in febrile and afebrile children using quantitative real-time PCR and standard PCR assays coupled with sequencing.DNA from blood specimens of 1,418 Gabonese children (1,258 febrile and 160 afebrile were analyzed. Overall, filarial DNA was detected in 95 (6.7% children, including 67 positive for M. perstans (4.7%, which was the most common. M. perstans was detected in 61/1,258 febrile children (4.8% and 6/160 afebrile children (3.8%, P = 0.6. Its prevalence increased statistically with age: 3.5%, 7.7% and 10.6% in children aged ≤ 5, 6-10 and 11-15 years, respectively. M. perstans prevalence was significantly higher in Koulamoutou and Lastourville (12% and 10.5%, respectively than in Franceville and Fougamou (2.6% and 2.4%, respectively. Loa loa was detected in seven febrile children including one co-infection with M. perstans. Finally, 21 filarial DNA positive were negative for M. perstans and Loa loa, but ITS sequencing could be performed for 12 and allowed the identification of a potential new species of Mansonella provisionally called "DEUX". Mansonella sp. "DEUX" was detected only in febrile children.Further study should be performed to characterize Mansonella sp. "DEUX" and evaluate the clinical significance of mansonellosis in humans.

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

DEFF Research Database (Denmark)

Enemark, Heidi Larsen; Oksanen, Antti; Chriél, Mariann

2017-01-01

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...... 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. (C...

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

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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.

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

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Madhusmita Bal

2016-11-01

Full Text Available 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

Identification of antigenic proteins of setaria cervi by immunoblotting technique

International Nuclear Information System (INIS)

Kaushal, N.A.; Kaushal, D.C.; Ghatak, S.

1987-01-01

Identification and characterization of antigenic proteins of Setaria cervi (bovine filarial parasite) adults and microfilariae was done by immunoblotting technique using hyperimmune rabbit sera against S. cervi and Brugia malayi. The antigens recognized by these sera were detected by using 125 I protein-A followed by autoradiography. Fifteen different antigens were observed to be common between adult and microfilarial stages of the parasite. Some stage specific antigens were also identified. Many antigens of S. cervi adults and microfilariae were also recognized by rabbit anti-B.malayi serum showing the existence of common antigenic determinants between the bovine and human filarial parasites

The origins of human parasites: Exploring the evidence for endoparasitism throughout human evolution.

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Mitchell, Piers D

2013-09-01

It is important to determine the origins of human parasites if we are to understand the health of past populations and the effects of parasitism upon human evolution. It also helps us to understand emerging infectious diseases and the modern clinical epidemiology of parasites. This study aims to distinguish those heirloom parasites that have infected humans and their ancestors throughout their evolution in Africa from those recent souvenir species to which humans have only become exposed following contact with animals during their migration across the globe. Ten such heirloom parasites are proposed, which appear to have been spread across the globe. Six further heirlooms are noted to have limited spread due to the constraints of their life cycle. Twelve souvenir parasites of humans are described, along with their animal reservoirs. While the origins of 28 species of endoparasite have been determined, many more species require further assessment once a more systematic analysis of ancient parasites in other regions of Africa has been undertaken. Copyright © 2013 Elsevier Inc. All rights reserved.

An integrated in vitro imaging platform for characterizing filarial parasite behavior within a multicellular microenvironment.

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Timothy Kassis

2014-11-01

Full Text Available Lymphatic Filariasis, a Neglected Tropical Disease, is caused by thread-like parasitic worms, including B. malayi, which migrate to the human lymphatic system following transmission. The parasites reside in collecting lymphatic vessels and lymph nodes for years, often resulting in lymphedema, elephantiasis or hydrocele. The mechanisms driving worm migration and retention within the lymphatics are currently unknown. We have developed an integrated in vitro imaging platform capable of quantifying B. malayi migration and behavior in a multicellular microenvironment relevant to the initial site of worm injection by incorporating the worm in a Polydimethylsiloxane (PDMS microchannel in the presence of human dermal lymphatic endothelial cells (LECs and human dermal fibroblasts (HDFs. The platform utilizes a motorized controllable microscope with CO2 and temperature regulation to allow for worm tracking experiments with high resolution over large length and time scales. Using post-acquisition algorithms, we quantified four parameters: 1 speed, 2 thrashing intensity, 3 percentage of time spent in a given cell region and 4 persistence ratio. We demonstrated the utility of our system by quantifying these parameters for L3 B. malayi in the presence of LECs and HDFs. Speed and thrashing increased in the presence of both cell types and were altered within minutes upon exposure to the anthelmintic drug, tetramisole. The worms displayed no targeted migration towards either cell type for the time course of this study (3 hours. When cells were not present in the chamber, worm thrashing correlated directly with worm speed. However, this correlation was lost in the presence of cells. The described platform provides the ability to further study B. malayi migration and behavior.

Targeting the Wolbachia cell division protein FtsZ as a new approach for antifilarial therapy.

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Zhiru Li

2011-11-01

Full Text Available The use of antibiotics targeting the obligate bacterial endosymbiont Wolbachia of filarial parasites has been validated as an approach for controlling filarial infection in animals and humans. Availability of genomic sequences for the Wolbachia (wBm present in the human filarial parasite Brugia malayi has enabled genome-wide searching for new potential drug targets. In the present study, we investigated the cell division machinery of wBm and determined that it possesses the essential cell division gene ftsZ which was expressed in all developmental stages of B. malayi examined. FtsZ is a GTPase thereby making the protein an attractive Wolbachia drug target. We described the molecular characterization and catalytic properties of Wolbachia FtsZ. We also demonstrated that the GTPase activity was inhibited by the natural product, berberine, and small molecule inhibitors identified from a high-throughput screen. Furthermore, berberine was also effective in reducing motility and reproduction in B. malayi parasites in vitro. Our results should facilitate the discovery of selective inhibitors of FtsZ as a novel anti-symbiotic approach for controlling filarial infection. NOTE: The nucleotide sequences reported in this paper are available in GenBank™ Data Bank under the accession number wAlB-FtsZ (JN616286.

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

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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.

Human Parasites in Medieval Europe: Lifestyle, Sanitation and Medical Treatment.

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Mitchell, Piers D

2015-01-01

Parasites have been infecting humans throughout our evolution. However, not all people suffered with the same species or to the same intensity throughout this time. Our changing way of life has altered the suitability of humans to infection by each type of parasite. This analysis focuses upon the evidence for parasites from archaeological excavations at medieval sites across Europe. Comparison between the patterns of infection in the medieval period allows us to see how changes in sanitation, herding animals, growing and fertilizing crops, the fishing industry, food preparation and migration all affected human susceptibility to different parasites. We go on to explore how ectoparasites may have spread infectious bacterial diseases, and also consider what medieval medical practitioners thought of parasites and how they tried to treat them. While modern research has shown the use of a toilet decreases the risk of contracting certain intestinal parasites, the evidence for past societies presented here suggests that the invention of latrines had no observable beneficial effects upon intestinal health. This may be because toilets were not sufficiently ubiquitous until the last century, or that the use of fresh human faeces for manuring crops still ensured those parasite species were easily able to reinfect the population. Copyright © 2015 Elsevier Ltd. All rights reserved.

Host-Parasite Interaction: Parasite-Derived and -Induced Proteases That Degrade Human Extracellular Matrix

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Carolina Piña-Vázquez

2012-01-01

Full Text Available Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina. The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.

Helminth Genomics: The Implications for Human Health

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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

Stage-Specific Transcriptome and Proteome Analyses of the Filarial Parasite Onchocerca volvulus and Its Wolbachia Endosymbiont

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Bennuru, Sasisekhar; Cotton, James A.; Ribeiro, Jose M. C.; Grote, Alexandra; Harsha, Bhavana; Holroyd, Nancy; Mhashilkar, Amruta; Molina, Douglas M.; Randall, Arlo Z.; Shandling, Adam D.; Unnasch, Thomas R.; Ghedin, Elodie; Berriman, Matthew

2016-01-01

ABSTRACT Onchocerciasis (river blindness) is a neglected tropical disease that has been successfully targeted by mass drug treatment programs in the Americas and small parts of Africa. Achieving the long-term goal of elimination of onchocerciasis, however, requires additional tools, including drugs, vaccines, and biomarkers of infection. Here, we describe the transcriptome and proteome profiles of the major vector and the human host stages (L1, L2, L3, molting L3, L4, adult male, and adult female) of Onchocerca volvulus along with the proteome of each parasitic stage and of its Wolbachia endosymbiont (wOv). In so doing, we have identified stage-specific pathways important to the parasite’s adaptation to its human host during its early development. Further, we generated a protein array that, when screened with well-characterized human samples, identified novel diagnostic biomarkers of O. volvulus infection and new potential vaccine candidates. This immunomic approach not only demonstrates the power of this postgenomic discovery platform but also provides additional tools for onchocerciasis control programs. PMID:27881553

Targeted mutagenesis in a human-parasitic nematode

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Gang, Spencer S.; Castelletto, Michelle L.

2017-01-01

Parasitic nematodes infect over 1 billion people worldwide and cause some of the most common neglected tropical diseases. Despite their prevalence, our understanding of the biology of parasitic nematodes has been limited by the lack of tools for genetic intervention. In particular, it has not yet been possible to generate targeted gene disruptions and mutant phenotypes in any parasitic nematode. Here, we report the development of a method for introducing CRISPR-Cas9-mediated gene disruptions in the human-parasitic threadworm Strongyloides stercoralis. We disrupted the S. stercoralis twitchin gene unc-22, resulting in nematodes with severe motility defects. Ss-unc-22 mutations were resolved by homology-directed repair when a repair template was provided. Omission of a repair template resulted in deletions at the target locus. Ss-unc-22 mutations were heritable; we passed Ss-unc-22 mutants through a host and successfully recovered mutant progeny. Using a similar approach, we also disrupted the unc-22 gene of the rat-parasitic nematode Strongyloides ratti. Our results demonstrate the applicability of CRISPR-Cas9 to parasitic nematodes, and thereby enable future studies of gene function in these medically relevant but previously genetically intractable parasites. PMID:29016680

Parasites of wild animals as a potential source of hazard to humans.

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Gałęcki, Remigiusz; Sokół, Rajmund; Koziatek, Sylwia

2015-01-01

The decline in wild animal habitats and the uncontrolled growth of their population make these animals come closer to human settlements. The aim of the study was to identify parasitic infections in wild animals in the selected area, and to specify the hazards they create for humans. In more than 66% of the analysed faecal samples from wild boar, hares, roe deer, deer and fallow deer various developmental forms of parasites were found. These included parasites dangerous for humans: Toxocara canis, Capillaria hepatica, Capillaria bovis, Trichuris suis, Trichuris ovis, Trichuris globulosus, Eimeria spp., and Trichostongylus spp. It is necessary to monitor parasitic diseases in wild animals as they can lead to the spread of parasites creating a hazard to humans, pets and livestock.

Human intestinal parasites in the past: new findings and a review

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Marcelo Luiz Carvalho Gonçalves

2003-01-01

Full Text Available Almost all known human specific parasites have been found in ancient feces. A review of the paleoparasitological helminth and intestinal protozoa findings available in the literature is presented. We also report the new paleoparasitologic findings from the examination performed in samples collected in New and Old World archaeological sites. New finds of ancylostomid, Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Trichostrongylus spp., Diphyllobothrium latum, Hymenolepis nana and Acantocephalan eggs are reported. According to the findings, it is probable that A. lumbricoides was originally a human parasite. Human ancylostomids, A. lumbricoides and T. trichiura, found in the New World in pre-Columbian times, have not been introduced into the Americas by land via Beringia. These parasites could not supported the cold climate of the region. Nomadic prehistoric humans that have crossed the Bering Land Bridge from Asia to the Americas in the last glaciation, probably during generations, would have lost these parasites, which life cycles need warm temperatures in the soil to be transmitted from host to host. Alternative routes are discussed for human parasite introduction into the Americas.

Food-borne human parasitic pathogens associated with household cockroaches and houseflies in Nigeria

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Oyetunde T. Oyeyemi

2016-03-01

Full Text Available Cockroaches and houseflies pose significant public health threat owning to their ability to mechanically transmit human intestinal parasites and other disease-causing microorganisms. This study aims at assessing the vectoral capacity of cockroaches and houseflies in the transmission of human intestinal parasites. Intestinal parasite external surface contamination of 130 cockroaches and 150 houseflies caught within dwelling places in Ilishan-Remo town, Ogun State, Nigeria was determined. Cockroaches (six parasite species were more contaminated than houseflies (four parasite species. The most prevalent parasites were Trichuris trichiura (74.0% and hookworm (63.0% in houseflies and cockroaches respectively. There were significant differences in the prevalence of hookworm, T. trichiura and Taenia spp. isolated from cockroaches and houseflies (P < 0.05. There is high contamination of human intestinal parasites in cockroaches and houseflies in human dwelling places in the study area, thus they have the ability to transmit these parasites to unkempt food materials.

The burden of non-filarial elephantiasis in Ethiopia.

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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.

Molecular Detection of Rickettsia amblyommii in Amblyomma americanum Parasitizing Humans

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2010-01-01

Detection of Rickettsia amblyommii in Amblyomma americanum Parasitizing Humans Ju Jiang~ Tamasin Yarina~ Melissa K. Miller,2 Ellen Y. Stromdahl? and...protein B gene (ompB) of Rickettsia amblyommii was employed to assess the threat of R. amblyommii exposure to humans parasitized by Amblyomma americanum...infection of and possibly disease in humans. Key Words: Amblyomma americanum-Lone star ticks-Real-time PCR- Rickettsia amblyommii. Introduction R

Anthropogenics: human influence on global and genetic homogenization of parasite populations.

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Zarlenga, Dante S; Hoberg, Eric; Rosenthal, Benjamin; Mattiucci, Simonetta; Nascetti, Giuseppe

2014-12-01

The distribution, abundance, and diversity of life on Earth have been greatly shaped by human activities. This includes the geographic expansion of parasites; however, measuring the extent to which humans have influenced the dissemination and population structure of parasites has been challenging. In-depth comparisons among parasite populations extending to landscape-level processes affecting disease emergence have remained elusive. New research methods have enhanced our capacity to discern human impact, where the tools of population genetics and molecular epidemiology have begun to shed light on our historical and ongoing influence. Only since the 1990s have parasitologists coupled morphological diagnosis, long considered the basis of surveillance and biodiversity studies, with state-of-the-art tools enabling variation to be examined among, and within, parasite populations. Prior to this time, populations were characterized only by phenotypic attributes such as virulence, infectivity, host range, and geographical location. The advent of genetic/molecular methodologies (multilocus allozyme electrophoresis, polymerase chain reaction-DNA [PCR-DNA] fragments analysis, DNA sequencing, DNA microsatellites, single nucleotide polymorphisms, etc.) have transformed our abilities to reveal variation among, and within, populations at local, regional, landscape, and global scales, and thereby enhanced our understanding of the biosphere. Numerous factors can affect population structure among parasites, e.g., evolutionary and ecological history, mode of reproduction and transmission, host dispersal, and life-cycle complexity. Although such influences can vary considerably among parasite taxa, anthropogenic factors are demonstrably perturbing parasite fauna. Minimal genetic structure among many geographically distinct (isolated) populations is a hallmark of human activity, hastened by geographic introductions, environmental perturbation, and global warming. Accelerating

A field trial of a PCR-based Mansonella ozzardi diagnosis assay detects high-levels of submicroscopic M. ozzardi infections in both venous blood samples and FTA? card dried blood spots

OpenAIRE

Medeiros, Jansen Fernandes; Almeida, Tatiana Amaral Pires; Silva, Lucyane Bastos Tavares; Rubio, Jose Miguel; Crainey, James Lee; Pessoa, Felipe Arley Costa; Luz, Sergio Luiz Bessa

2015-01-01

Background Mansonella ozzardi is a poorly understood human filarial parasite with a broad distribution throughout Latin America. Most of what is known about its parasitism has come from epidemiological studies that have estimated parasite incidence using light microscopy. Light microscopy can, however, miss lighter, submicroscopic, infections. In this study we have compared M. ozzardi incidence estimates made using light microscopy, with estimates made using PCR. Methods 214 DNA extracts made...

Filarial lymphedema is characterized by antigen-specific Th1 and th17 proinflammatory responses and a lack of regulatory T cells.

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Subash Babu

Full Text Available Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients.To elucidate the role of CD4(+ T cell subsets in the development of lymphatic pathology, we examined specific sets of cytokines in individuals with filarial lymphedema in response to parasite antigen (BmA and compared them with responses from asymptomatic infected individuals. We also examined expression patterns of Toll-like receptors (TLR1-10 and Nod-like receptors (Nod1, Nod2, and NALP3 in response to BmA. BmA induced significantly higher production of Th1-type cytokines-IFN-gamma and TNF-alpha-in patients with lymphedema compared with asymptomatic individuals. Notably, expression of the Th17 family of cytokines-IL-17A, IL-17F, IL-21, and IL-23-was also significantly upregulated by BmA stimulation in lymphedema patients. In contrast, expression of Foxp3, GITR, TGFbeta, and CTLA-4, known to be expressed by regulatory T cells, was significantly impaired in patients with lymphedema. BmA also induced significantly higher expression of TLR2, 4, 7, and 9 as well Nod1 and 2 mRNA in patients with lymphedema compared with asymptomatic controls.Our findings implicate increased Th1/Th17 responses and decreased regulatory T cells as well as regulation of Toll- and Nod-like receptors in pathogenesis of filarial lymphedema.

Anthropogenics: Human influence on global and genetic homogenization of parasite populations

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The distribution, abundance, and diversity of life on Earth have been greatly shaped by human activities. This is no truer than in the geographic expansion of parasites; however, measuring the extent to which humans have influenced the dissemination and population structure of parasites has been cha...

Parasite Infection, Carcinogenesis and Human Malignancy

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Hoang van Tong

2017-02-01

Full Text Available Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity.

Parasite Infection, Carcinogenesis and Human Malignancy.

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van Tong, Hoang; Brindley, Paul J; Meyer, Christian G; Velavan, Thirumalaisamy P

2017-02-01

Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasitePlasmodium knowlesi

KAUST Repository

Moon, Robert W.; Sharaf, Hazem; Hastings, Claire H.; Ho, Yung Shwen; Nair, Mridul; Rchiad, ‍ Zineb; Knuepfer, Ellen; Ramaprasad, Abhinay; Mohring, Franziska; Amir, Amirah; Yusuf, Noor A.; Hall, Joanna; Almond, Neil; Lau, Yee Ling; Pain, Arnab; Blackman, Michael J.; Holder, Anthony A.

2016-01-01

The dominant cause of malaria in Malaysia is now Plasmodium knowlesi, a zoonotic parasite of cynomolgus macaque monkeys found throughout South East Asia. Comparative genomic analysis of parasites adapted to in vitro growth in either cynomolgus or human RBCs identified a genomic deletion that includes the gene encoding normocyte-binding protein Xa (NBPXa) in parasites growing in cynomolgus RBCs but not in human RBCs. Experimental deletion of the NBPXa gene in parasites adapted to growth in human RBCs (which retain the ability to grow in cynomolgus RBCs) restricted them to cynomolgus RBCs, demonstrating that this gene is selectively required for parasite multiplication and growth in human RBCs. NBPXa-null parasites could bind to human RBCs, but invasion of these cells was severely impaired. Therefore, NBPXa is identified as a key mediator of P. knowlesi human infection and may be a target for vaccine development against this emerging pathogen.

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasitePlasmodium knowlesi

KAUST Repository

Moon, Robert W.

2016-06-15

The dominant cause of malaria in Malaysia is now Plasmodium knowlesi, a zoonotic parasite of cynomolgus macaque monkeys found throughout South East Asia. Comparative genomic analysis of parasites adapted to in vitro growth in either cynomolgus or human RBCs identified a genomic deletion that includes the gene encoding normocyte-binding protein Xa (NBPXa) in parasites growing in cynomolgus RBCs but not in human RBCs. Experimental deletion of the NBPXa gene in parasites adapted to growth in human RBCs (which retain the ability to grow in cynomolgus RBCs) restricted them to cynomolgus RBCs, demonstrating that this gene is selectively required for parasite multiplication and growth in human RBCs. NBPXa-null parasites could bind to human RBCs, but invasion of these cells was severely impaired. Therefore, NBPXa is identified as a key mediator of P. knowlesi human infection and may be a target for vaccine development against this emerging pathogen.

Helminth parasites of dogs from two resource-limited communities in South Africa : research communication

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W.N. Minnaar

1999-07-01

Full Text Available Biological samples were collected from dogs in resource-limited communities in the North-West and Gauteng Provinces of South Africa to assess the prevalence of helminth parasitism. These samples included adhesive tape peri-anal skin swabs and fresh faecal samples for helminth examination, and thick and thin blood films (smears and whole-blood samples in anticoagulant for examination of filarial nematode microfilariae and haemoprotozoa. The eggs of Ancylostoma caninum, Toxocara canis, Toxascaris leonina, Dipylidium caninum and taeniids were identified. None of the blood samples and smears tested positive for microfilariae of Dirofilaria immitis or Dipetalonema spp. or for haemoprotozoa. The adhesive tape swabs were negative for cestode eggs and segments. Most of the helminth parasites identified in this study are zoonotic and consequently are regarded as a public health hazard.

Gastrointestinal parasites of canids, a latent risk to human health in Tunisia.

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Oudni-M'rad, Myriam; Chaâbane-Banaoues, Raja; M'rad, Selim; Trifa, Fatma; Mezhoud, Habib; Babba, Hamouda

2017-06-05

Although data on the parasite environmental contamination are crucial to implement strategies for control and treatment, information about zoonotic helminths is very limited in Tunisia. Contamination of areas with canid faeces harboring infective parasite elements represents a relevant health-risk impact for humans. The aim of this study was to assess the environmental contamination with eggs and oocysts of gastrointestinal parasites of dogs and wild canids in Tunisia with special attention to those that can be transmitted to humans. One thousand two hundred and seventy faecal samples from stray dogs and 104 from wild canids (red foxes and golden jackals) were collected from different geographical regions throughout Tunisia. The helminth eggs and protozoan oocysts were concentrated by sucrose flotation and identified by microscopic examination. The most frequently observed parasites in dog samples were Toxocara spp. (27.2%), E. granulosus (25.8%), and Coccidia (13.1%). For wild canid faeces, the most commonly encountered parasites were Toxocara spp. (16.3%) followed by Capillaria spp. (9.6%). The parasite contamination of dog faeces varied significantly from one region to another in function of the climate. To our knowledge, the study highlights for the first time in Tunisia a serious environmental contamination by numerous parasitic stages infective to humans. Efforts should be made to increase the awareness of the contamination risk of such parasites in the environment and implement a targeted educational program.

Who Is Doing the Dance in Epididymis: The Principle of Moblile Echogenicities Without Filarial Infection: Case Report.

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Wang, Zhu; Yang, Zheng; Lei, Yang-Yang; Zhang, Ya-Dong; Chen, Li-Da; Xie, Xiao-Yan; Lu, Ming-De; Wang, Wei

2015-08-01

The aim of this study was to explore the principle of moblile echogenicities in epididymis in patients with a history of postvasectomy or infertility, which were reported as the characteristic sonographic sign of filarial infection.We reported a 38-year-old man presented with a 3-year history of infertility after marriage. Ultrasound imaging revealed an enlarged body in the inner left epididymis along with innumerable punctate mobile echogenicities, which showed random to-and-fro movements in the left epididymis. This had previously been recognized as the sonographic filarial dance sign of live filarial worms or microfilaria. The patient subsequently underwent needle aspiration of the left epididymis.Histopathological examination confirmed that the mobile echogenicities were a large number of macrophages with phagocytized sperm or clumps of agglutinated sperm. Our report includes a video clip that will help familiarize readers with this phenomenon.Our case highlighted that moblile echogenicities should be an important sign for epididymal obstruction to initiate corresponding treatment.

Origin of the human malaria parasite Plasmodium falciparum in gorillas.

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Liu, Weimin; Li, Yingying; Learn, Gerald H; Rudicell, Rebecca S; Robertson, Joel D; Keele, Brandon F; Ndjango, Jean-Bosco N; Sanz, Crickette M; Morgan, David B; Locatelli, Sabrina; Gonder, Mary K; Kranzusch, Philip J; Walsh, Peter D; Delaporte, Eric; Mpoudi-Ngole, Eitel; Georgiev, Alexander V; Muller, Martin N; Shaw, George M; Peeters, Martine; Sharp, Paul M; Rayner, Julian C; Hahn, Beatrice H

2010-09-23

Plasmodium falciparum is the most prevalent and lethal of the malaria parasites infecting humans, yet the origin and evolutionary history of this important pathogen remain controversial. Here we develop a single-genome amplification strategy to identify and characterize Plasmodium spp. DNA sequences in faecal samples from wild-living apes. Among nearly 3,000 specimens collected from field sites throughout central Africa, we found Plasmodium infection in chimpanzees (Pan troglodytes) and western gorillas (Gorilla gorilla), but not in eastern gorillas (Gorilla beringei) or bonobos (Pan paniscus). Ape plasmodial infections were highly prevalent, widely distributed and almost always made up of mixed parasite species. Analysis of more than 1,100 mitochondrial, apicoplast and nuclear gene sequences from chimpanzees and gorillas revealed that 99% grouped within one of six host-specific lineages representing distinct Plasmodium species within the subgenus Laverania. One of these from western gorillas comprised parasites that were nearly identical to P. falciparum. In phylogenetic analyses of full-length mitochondrial sequences, human P. falciparum formed a monophyletic lineage within the gorilla parasite radiation. These findings indicate that P. falciparum is of gorilla origin and not of chimpanzee, bonobo or ancient human origin.

Control of human parasitic diseases: Context and overview.

Science.gov (United States)

Molyneux, David H

2006-01-01

The control of parasitic diseases of humans has been undertaken since the aetiology and natural history of the infections was recognized and the deleterious effects on human health and well-being appreciated by policy makers, medical practitioners and public health specialists. However, while some parasitic infections such as malaria have proved difficult to control, as defined by a sustained reduction in incidence, others, particularly helminth infections can be effectively controlled. The different approaches to control from diagnosis, to treatment and cure of the clinically sick patient, to control the transmission within the community by preventative chemotherapy and vector control are outlined. The concepts of eradication, elimination and control are defined and examples of success summarized. Overviews of the health policy and financing environment in which programmes to control or eliminate parasitic diseases are positioned and the development of public-private partnerships as vehicles for product development or access to drugs for parasite disease control are discussed. Failure to sustain control of parasites may be due to development of drug resistance or the failure to implement proven strategies as a result of decreased resources within the health system, decentralization of health management through health-sector reform and the lack of financial and human resources in settings where per capita government expenditure on health may be less than $US 5 per year. However, success has been achieved in several large-scale programmes through sustained national government investment and/or committed donor support. It is also widely accepted that the level of investment in drug development for the parasitic diseases of poor populations is an unattractive option for pharmaceutical companies. The development of partnerships to specifically address this need provides some hope that the intractable problems of the treatment regimens for the trypanosomiases and

Suppression of Brugia malayi (sub-periodic larval development in Aedes aegypti (Liverpool strain fed on blood of animals immunized with microfilariae

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K Athisaya Mary

2005-07-01

Full Text Available Preliminary studies were carried out to investigate the role of filarial specific antibodies, raised in an animal model against the filarial parasite, Brugia malayi (sub-periodic, in blocking their early development in an experimental mosquito host, Aedes aegypti (Liverpool strain. In order to generate filarial specific antibodies, Mongolian gerbils, Meriones unguiculatus, were immunized either with live microfilariae (mf of B. malayi or their homogenate. Mf were harvested from the peritoneal cavity of Mongolian gerbils with patent infection of B. malayi and fed to A. aegypti along with the blood from immunized animals. Development of the parasite in infected mosquitoes was monitored until they reached infective stage larvae (L3. Fewer number of parasites developed to first stage (L1 and subsequently to L2 and L3 in mosquitoes fed with blood of immunized animals, when compared to those fed with blood of control animals. The results thus indicated that filarial parasite specific antibodies present in the blood of the immunized animals resulted in the reduction of number of larvae of B. malayi developing in the mosquito host.

Transcriptomes and pathways associated with infectivity, survival and immunogenicity in Brugia malayi L3

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Spiro David

2009-06-01

Full Text Available Abstract Background Filarial nematode parasites cause serious diseases such as elephantiasis and river blindness in humans, and heartworm infections in dogs. Third stage filarial larvae (L3 are a critical stage in the life cycle of filarial parasites, because this is the stage that is transmitted by arthropod vectors to initiate infections in mammals. Improved understanding of molecular mechanisms associated with this transition may provide important leads for development of new therapies and vaccines to prevent filarial infections. This study explores changes in gene expression associated with the transition of Brugia malayi third stage larvae (BmL3 from mosquitoes into mammalian hosts and how these changes are affected by radiation. Radiation effects are especially interesting because irradiated L3 induce partial immunity to filarial infections. The underlying molecular mechanisms responsible for the efficacy of such vaccines are unkown. Results Expression profiles were obtained using a new filarial microarray with 18, 104 64-mer elements. 771 genes were identified as differentially expressed in two-way comparative analyses of the three L3 types. 353 genes were up-regulated in mosquito L3 (L3i relative to cultured L3 (L3c. These genes are important for establishment of filarial infections in mammalian hosts. Other genes were up-regulated in L3c relative to L3i (234 or irradiated L3 (L3ir (22. These culture-induced transcripts include key molecules required for growth and development. 165 genes were up-regulated in L3ir relative to L3c; these genes encode highly immunogenic proteins and proteins involved in radiation repair. L3ir and L3i have similar transcription profiles for genes that encode highly immunogenic proteins, antioxidants and cuticle components. Conclusion Changes in gene expression that normally occur during culture under conditions that support L3 development and molting are prevented or delayed by radiation. This may explain

Dogs, cats, parasites, and humans in Brazil: opening the black box

Science.gov (United States)

2014-01-01

Dogs and cats in Brazil serve as primary hosts for a considerable number of parasites, which may affect their health and wellbeing. These may include endoparasites (e.g., protozoa, cestodes, trematodes, and nematodes) and ectoparasites (i.e., fleas, lice, mites, and ticks). While some dog and cat parasites are highly host-specific (e.g., Aelurostrongylus abstrusus and Felicola subrostratus for cats, and Angiostrongylus vasorum and Trichodectes canis for dogs), others may easily switch to other hosts, including humans. In fact, several dog and cat parasites (e.g., Toxoplasma gondii, Dipylidium caninum, Ancylostoma caninum, Strongyloides stercoralis, and Toxocara canis) are important not only from a veterinary perspective but also from a medical standpoint. In addition, some of them (e.g., Lynxacarus radovskyi on cats and Rangelia vitalii in dogs) are little known to most veterinary practitioners working in Brazil. This article is a compendium on dog and cat parasites in Brazil and a call for a One Health approach towards a better management of some of these parasites, which may potentially affect humans. Practical aspects related to the diagnosis, treatment, and control of parasitic diseases of dogs and cats in Brazil are discussed. PMID:24423244

The genome of the simian and human malaria parasite Plasmodium knowlesi

DEFF Research Database (Denmark)

Pain, A; Böhme, U; Berry, A E

2008-01-01

Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite...... species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood...... cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described...

Circulating microbial products and acute phase proteins as markers of pathogenesis in lymphatic filarial disease.

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R Anuradha

Full Text Available Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients. Dysregulated host inflammatory responses leading to systemic immune activation are thought to play a central role in filarial disease pathogenesis. We measured the plasma levels of microbial translocation markers, acute phase proteins, and inflammatory cytokines in individuals with chronic filarial pathology with (CP Ag+ or without (CP Ag- active infection; with clinically asymptomatic infections (INF; and in those without infection (endemic normal [EN]. Comparisons between the two actively infected groups (CP Ag+ compared to INF and those without active infection (CP Ag- compared to EN were used preliminarily to identify markers of pathogenesis. Thereafter, we tested for group effects among all the four groups using linear models on the log transformed responses of the markers. Our data suggest that circulating levels of microbial translocation products (lipopolysaccharide and LPS-binding protein, acute phase proteins (haptoglobin and serum amyloid protein-A, and inflammatory cytokines (IL-1β, IL-12, and TNF-α are associated with pathogenesis of disease in lymphatic filarial infection and implicate an important role for circulating microbial products and acute phase proteins.

Human fascioliasis: a parasitic health problem in Dakahlia Governorate, Egypt.

Science.gov (United States)

el Shazly, A M; Handousa, A E; Youssef, M E; Rizk, H; Hamouda, M M

1991-08-01

Fascioliasis has a cosmopolitan distribution and is prevalent in sheep-raising countries. Now, it is an increasingly important parasite of man in the Mediterranean countries. In Dakahlia G., human fascioliasis has imposed itself as a parasitic health problem. In this paper, 23 human cases were selected to throw some light on the signs, symptoms and diagnosis of the disease. It was concluded that painful hepatomegaly, fever, anaemia and marked eosinophilia are tetrad suggesting fascioliasis in patient who has consumed watercress as green salade. Data concerning treatment and follow up will be published later.

Regional Disease Vector Ecology Profile: The Middle East

Science.gov (United States)

1999-10-01

disturbances and blindness. The parasite is a filarial nematode worm, Onchocerca volvulus . A related species, O. fasciata, occurs in camels but does...which O. volvulus multiplies. Microfilariae in human skin are ingested by vector black flies when they suck blood. In the Middle East, vectors are

HOW HUMAN HISTORY HAS INFLUENCED GEOGRAPHY AND GENETICS OF PARASITE POPULATIONS

Science.gov (United States)

Human beings have radically altered agricultural landscapes, establishing a limited repertoire of plants and animals over vast expanses. Here, I consider what impact such a history may have had on the distribution and diversity of animal parasite, hypothesizing that certain parasites may have been '...

Recognition of Human Erythrocyte Receptors by the Tryptophan-Rich Antigens of Monkey Malaria Parasite Plasmodium knowlesi.

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Kriti Tyagi

Full Text Available The monkey malaria parasite Plasmodium knowlesi also infect humans. There is a lack of information on the molecular mechanisms that take place between this simian parasite and its heterologous human host erythrocytes leading to this zoonotic disease. Therefore, we investigated here the binding ability of P. knowlesi tryptophan-rich antigens (PkTRAgs to the human erythrocytes and sharing of the erythrocyte receptors between them as well as with other commonly occurring human malaria parasites.Six PkTRAgs were cloned and expressed in E.coli as well as in mammalian CHO-K1 cell to determine their human erythrocyte binding activity by cell-ELISA, and in-vitro rosetting assay, respectively.Three of six PkTRAgs (PkTRAg38.3, PkTRAg40.1, and PkTRAg67.1 showed binding to human erythrocytes. Two of them (PkTRAg40.1 and PkTRAg38.3 showed cross-competition with each other as well as with the previously described P.vivax tryptophan-rich antigens (PvTRAgs for human erythrocyte receptors. However, the third protein (PkTRAg67.1 utilized the additional but different human erythrocyte receptor(s as it did not cross-compete for erythrocyte binding with either of these two PkTRAgs as well as with any of the PvTRAgs. These three PkTRAgs also inhibited the P.falciparum parasite growth in in-vitro culture, further indicating the sharing of human erythrocyte receptors by these parasite species and the biological significance of this receptor-ligand interaction between heterologous host and simian parasite.Recognition and sharing of human erythrocyte receptor(s by PkTRAgs with human parasite ligands could be part of the strategy adopted by the monkey malaria parasite to establish inside the heterologous human host.

Recognition of Human Erythrocyte Receptors by the Tryptophan-Rich Antigens of Monkey Malaria Parasite Plasmodium knowlesi.

Science.gov (United States)

Tyagi, Kriti; Gupta, Deepali; Saini, Ekta; Choudhary, Shilpa; Jamwal, Abhishek; Alam, Mohd Shoeb; Zeeshan, Mohammad; Tyagi, Rupesh K; Sharma, Yagya D

2015-01-01

The monkey malaria parasite Plasmodium knowlesi also infect humans. There is a lack of information on the molecular mechanisms that take place between this simian parasite and its heterologous human host erythrocytes leading to this zoonotic disease. Therefore, we investigated here the binding ability of P. knowlesi tryptophan-rich antigens (PkTRAgs) to the human erythrocytes and sharing of the erythrocyte receptors between them as well as with other commonly occurring human malaria parasites. Six PkTRAgs were cloned and expressed in E.coli as well as in mammalian CHO-K1 cell to determine their human erythrocyte binding activity by cell-ELISA, and in-vitro rosetting assay, respectively. Three of six PkTRAgs (PkTRAg38.3, PkTRAg40.1, and PkTRAg67.1) showed binding to human erythrocytes. Two of them (PkTRAg40.1 and PkTRAg38.3) showed cross-competition with each other as well as with the previously described P.vivax tryptophan-rich antigens (PvTRAgs) for human erythrocyte receptors. However, the third protein (PkTRAg67.1) utilized the additional but different human erythrocyte receptor(s) as it did not cross-compete for erythrocyte binding with either of these two PkTRAgs as well as with any of the PvTRAgs. These three PkTRAgs also inhibited the P.falciparum parasite growth in in-vitro culture, further indicating the sharing of human erythrocyte receptors by these parasite species and the biological significance of this receptor-ligand interaction between heterologous host and simian parasite. Recognition and sharing of human erythrocyte receptor(s) by PkTRAgs with human parasite ligands could be part of the strategy adopted by the monkey malaria parasite to establish inside the heterologous human host.

Zoonotic and Non-Zoonotic Diseases in Relation to Human Personality and Societal Values: Support for the Parasite-Stress Model

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Randy Thornhill

2010-04-01

Full Text Available The parasite-stress model of human sociality proposes that humans' ontogenetic experiences with infectious diseases as well as their evolutionary historical interactions with these diseases exert causal influences on human psychology and social behavior. This model has been supported by cross-national relationships between parasite prevalence and human personality traits, and between parasite prevalence and societal values. Importantly, the parasite-stress model emphasizes the causal role of non-zoonotic parasites (which have the capacity for human-to-human transmission, rather than zoonotic parasites (which do not, but previous studies failed to distinguish between these conceptually distinct categories. The present investigation directly tested the differential predictive effects of zoonotic and non-zoonotic (both human-specific and multihost parasite prevalence on personality traits and societal values. Supporting the parasite-stress model, cross-national differences in personality traits (unrestricted sexuality, extraversion, openness to experiences and in societal values (individualism, collectivism, gender equality, democratization are predicted specifically by non-zoonotic parasite prevalence.

Human parasitic protozoan infection to infertility: a systematic review.

Science.gov (United States)

Shiadeh, Malihe Nourollahpour; Niyyati, Maryam; Fallahi, Shirzad; Rostami, Ali

2016-02-01

Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify the potentially relevant studies on protozoan parasitic infections and their implications in human and animal model infertility. Literature described that some of the protozoan parasites such as Trichomonas vaginalis may cause deformities of the genital tract, cervical neoplasia, and tubal and atypical pelvic inflammations in women and also non-gonoccocal urethritis, asthenozoospermia, and teratozoospermia in men. Toxopalasma gondii could cause endometritis, impaired folliculogenesis, ovarian and uterine atrophy, adrenal hypertrophy, vasculitis, and cessation of estrus cycling in female and also decrease in semen quality, concentration, and motility in male. Trypanosoma cruzi inhibits cell division in embryos and impairs normal implantation and development of placenta. Decrease in gestation rate, infection of hormone-producing glands, parasite invasion of the placenta, and overproduction of inflammatory cytokines in the oviducts and uterine horns are other possible mechanisms induced by Trypanosoma cruzi to infertility. Plasmodium spp. and Trypanosoma brucei spp. cause damage in pituitary gland, hormonal disorders, and decreased semen quality. Entamoeba histolytica infection leads to pelvic pain, salpingitis, tubo-ovarian abscess, and genital ulcers. Cutaneous and visceral leishmaniasis can induce genital lesion, testicular amyloidosis, inflammation of epididymis, prostatitis, and sperm abnormality in human and animals. In addition, some epidemiological studies have reported that rates of protozoan infections in infertile patients are higher than healthy controls. The current review indicates that protozoan parasitic

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

Science.gov (United States)

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

Human Parasitic Diseases in Bulgaria in Between 2013-2014

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Rainova, Iskra; Harizanov, Rumen; Kaftandjiev, Iskren; Tsvetkova, Nina; Mikov, Ognyan; Kaneva, Eleonora

2018-01-01

Background: In Bulgaria, more than 20 autochthonous human parasitic infections have been described and some of them are widespread. Over 50 imported protozoan and helminthic infections represent diagnostic and therapeutic challenges and pose epidemiological risks due to the possibility of local transmission. Aims: To establish the distribution of autochthonous and imported parasitic diseases among the population of the country over a 2-year period (2013-2014) and to evaluate their significance in the public health system. Study Design: Cross sectional study. Methods: We used the annual reports by regional health inspectorates and data from the National Reference Laboratory at the National Centre of Infectious and Parasitic Diseases on all individuals infected with parasitic diseases in the country. Prevalence was calculated for parasitic diseases with few or absent clinical manifestations (oligosymptomatic or asymptomatic infections). Incidence per 100.000 was calculated for diseases with an overt clinical picture or those that required hospitalisation and specialised medical interventions (e.g. surgery). Results: During the research period, parasitological studies were conducted on 1441.244 persons, and parasitic infections were diagnosed in 22.039 individuals. Distribution of various parasitic pathogens among the population displayed statistically significant differences in prevalence for some intestinal parasites (enterobiasis 0.81%, giardiasis 0.34% and blastocystosis 0.22%). For certain zoonotic diseases such as cystic echinococcosis (average incidence of 3.99 per 100.000) and trichinellosis (average incidence of 0.8 per 100.000), the incidence exceeds several times the annual incidence recorded in the European Union. Conclusion: Parasitic diseases still pose a substantial problem with social and medical impacts on the residents of our country. Improved efficiency regarding autochthonous and imported parasitic diseases is essential in providing the public

Differential expression of IgE and IgG4 specific antibody responses in asymptomatic and chronic human filariasis

NARCIS (Netherlands)

Kurniawan, A.; Yazdanbakhsh, M.; van Ree, R.; Aalberse, R.; Selkirk, M. E.; Partono, F.; Maizels, R. M.

1993-01-01

A population of 164 adult individuals resident in an area endemic for Brugia malayi lymphatic filariasis has been studied for humoral immune responses to filarial parasites. Antibody levels to Ag extracted from adult worms were determined for each of the IgG subclasses, for IgM and for IgE. The

Application of small RNA technology for improved control of parasitic helminths.

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Britton, Collette; Winter, Alan D; Marks, Neil D; Gu, Henry; McNeilly, Tom N; Gillan, Victoria; Devaney, Eileen

2015-08-15

Over the last decade microRNAs (miRNAs) and small interfering RNAs (siRNAs) have emerged as important regulators of post-transcriptional gene expression. miRNAs are short, non-coding RNAs that regulate a variety of processes including cancer, organ development and immune function. This class of small RNAs bind with partial complementarity to their target mRNA sequences, most often in the 3'UTR, to negatively regulate gene expression. In parasitic helminths, miRNAs are being increasingly studied for their potential roles in development and host-parasite interactions. The availability of genome data, combined with small RNA sequencing, has paved the way to profile miRNAs expressed at particular developmental stages for many parasitic helminths. While some miRNAs are conserved across species, others appear to be unique to specific parasites, suggesting important roles in adaptation and survival in the host environment. Some miRNAs are released from parasites, in exosomes or in protein complexes, and the potential effects of these on host immune function are being increasingly studied. In addition, release of miRNAs from schistosome and filarial parasites into host plasma can be exploited for the development of specific and sensitive diagnostic biomarkers of infection. Interfering with miRNA function, as well as silencing key components of the pathways they regulate, will progress our understanding of parasite development and provide a novel approach to therapeutic control. RNA interference (RNAi) by siRNAs has proven to be inconsistent in parasitic nematodes. However, the recent successes reported for schistosome and liver fluke RNAi, encourage further efforts to enhance delivery of RNA and improve in vitro culture systems and assays to monitor phenotypic effects in nematodes. These improvements are important for the establishment of reliable functional genomic platforms for novel drug and vaccine development. In this review we focus on the important roles of mi

Defining Brugia malayi and Wolbachia symbiosis by stage-specific dual RNA-seq.

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Alexandra Grote

2017-03-01

Full Text Available Filarial nematodes currently infect up to 54 million people worldwide, with millions more at risk for infection, representing the leading cause of disability in the developing world. Brugia malayi is one of the causative agents of lymphatic filariasis and remains the only human filarial parasite that can be maintained in small laboratory animals. Many filarial nematode species, including B. malayi, carry an obligate endosymbiont, the alpha-proteobacteria Wolbachia, which can be eliminated through antibiotic treatment. Elimination of the endosymbiont interferes with development, reproduction, and survival of the worms within the mamalian host, a clear indicator that the Wolbachia are crucial for survival of the parasite. Little is understood about the mechanism underlying this symbiosis.To better understand the molecular interplay between these two organisms we profiled the transcriptomes of B. malayi and Wolbachia by dual RNA-seq across the life cycle of the parasite. This helped identify functional pathways involved in this essential symbiotic relationship provided by the co-expression of nematode and bacterial genes. We have identified significant stage-specific and gender-specific differential expression in Wolbachia during the nematode's development. For example, during female worm development we find that Wolbachia upregulate genes involved in ATP production and purine biosynthesis, as well as genes involved in the oxidative stress response.This global transcriptional analysis has highlighted specific pathways to which both Wolbachia and B. malayi contribute concurrently over the life cycle of the parasite, paving the way for the development of novel intervention strategies.

Lipoprotein biosynthesis as a target for anti-Wolbachia treatment of filarial nematodes

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Slatko Barton E

2010-10-01

Full Text Available Abstract Background Lymphatic filariasis and onchocerciasis are debilitating diseases caused by filarial nematodes. Disease pathogenesis is induced by inflammatory responses following the death of the parasite. Wolbachia endosymbionts of filariae are potent inducers of innate and adaptive inflammation and bacterial lipoproteins have been identified as the ligands that bind toll-like receptors (TLR 2 and TLR6. Lipoproteins are important structural and functional components of bacteria and therefore enzymes involved in Wolbachia lipoprotein biosynthesis are potential chemotherapeutic targets. Results Globomycin, a signal peptidase II (LspA inhibitor, has activity against Gram-negative bacteria and a putative lspA gene has been identified from the Wolbachia genome of Brugia malayi (wBm. The amino acids required for function are strictly conserved and functionality was verified by complementation tests in a temperature-sensitive Escherichia coli lspA mutant. Also, transformation of wild type E. coli with Wolbachia lspA conferred significant globomycin resistance. A cell-based screen has been developed utilizing a Wolbachia-containing Aedes albopictus cell line to assay novel compounds active against Wolbachia. Globomycin was screened using this assay, which resulted in a dose-dependent reduction in Wolbachia load. Furthermore, globomycin was also effective in reducing the motility and viability of adult B. malayi in vitro. Conclusions These studies validate lipoprotein biosynthesis as a target in an organism for which no genetic tools are available. Further studies to evaluate drugs targeting this pathway are underway as part of the A-WOL drug discovery and development program.

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

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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.

Viruses of parasites as actors in the parasite-host relationship: A "ménage à trois".

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Gómez-Arreaza, Amaranta; Haenni, Anne-Lise; Dunia, Irene; Avilán, Luisana

2017-02-01

The complex parasite-host relationship involves multiple mechanisms. Moreover, parasites infected by viruses modify this relationship adding more complexity to the system that now comprises three partners. Viruses infecting parasites were described several decades ago. However, until recently little was known about the viruses involved and their impact on the resulting disease caused to the hosts. To clarify this situation, we have concentrated on parasitic diseases caused to humans and on how virus-infected parasites could alter the symptoms inflicted on the human host. It is clear that the effect caused to the human host depends on the virus and on the parasite it has infected. Consequently, the review is divided as follows: Viruses with a possible effect on the virulence of the parasite. This section reviews pertinent articles showing that infection of parasites by viruses might increase the detrimental effect of the tandem virus-parasite on the human host (hypervirulence) or decrease virulence of the parasite (hypovirulence). Parasites as vectors affecting the transmission of viruses. In some cases, the virus-infected parasite might facilitate the transfer of the virus to the human host. Parasites harboring viruses with unidentified effects on their host. In spite of recently renewed interest in parasites in connection with their viruses, there still remains a number of cases in which the effect of the virus of a given parasite on the human host remains ambiguous. The triangular relationship between the virus, the parasite and the host, and the modulation of the pathogenicity and virulence of the parasites by viruses should be taken into account in the rationale of fighting against parasites. Copyright © 2016 Elsevier B.V. All rights reserved.

Membrane-Wrapping Contributions to Malaria Parasite Invasion of the Human Erythrocyte

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Dasgupta, Sabyasachi; Auth, Thorsten; Gov, Nir S.; Satchwell, Timothy J.; Hanssen, Eric; Zuccala, Elizabeth S.; Riglar, David T.; Toye, Ashley M.; Betz, Timo; Baum, Jake; Gompper, Gerhard

2014-01-01

The blood stage malaria parasite, the merozoite, has a small window of opportunity during which it must successfully target and invade a human erythrocyte. The process of invasion is nonetheless remarkably rapid. To date, mechanistic models of invasion have focused predominantly on the parasite actomyosin motor contribution to the energetics of entry. Here, we have conducted a numerical analysis using dimensions for an archetypal merozoite to predict the respective contributions of the host-parasite interactions to invasion, in particular the role of membrane wrapping. Our theoretical modeling demonstrates that erythrocyte membrane wrapping alone, as a function of merozoite adhesive and shape properties, is sufficient to entirely account for the first key step of the invasion process, that of merozoite reorientation to its apex and tight adhesive linkage between the two cells. Next, parasite-induced reorganization of the erythrocyte cytoskeleton and release of parasite-derived membrane can also account for a considerable energetic portion of actual invasion itself, through membrane wrapping. Thus, contrary to the prevailing dogma, wrapping by the erythrocyte combined with parasite-derived membrane release can markedly reduce the expected contributions of the merozoite actomyosin motor to invasion. We therefore propose that invasion is a balance between parasite and host cell contributions, evolved toward maximal efficient use of biophysical forces between the two cells. PMID:24988340

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

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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.

Heritability of the human infectious reservoir of malaria parasites.

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Yaye Ramatoulaye Lawaly

Full Text Available BACKGROUND: Studies on human genetic factors associated with malaria have hitherto concentrated on their role in susceptibility to and protection from disease. In contrast, virtually no attention has been paid to the role of human genetics in eliciting the production of parasite transmission stages, the gametocytes, and thus enhancing the spread of disease. METHODS AND FINDINGS: We analysed four longitudinal family-based cohort studies from Senegal and Thailand followed for 2-8 years and evaluated the relative impact of the human genetic and non-genetic factors on gametocyte production in infections of Plasmodium falciparum or P. vivax. Prevalence and density of gametocyte carriage were evaluated in asymptomatic and symptomatic infections by examination of Giemsa-stained blood smears and/or RT-PCR (for falciparum in one site. A significant human genetic contribution was found to be associated with gametocyte prevalence in asymptomatic P. falciparum infections. By contrast, there was no heritability associated with the production of gametocytes for P. falciparum or P. vivax symptomatic infections. Sickle cell mutation, HbS, was associated with increased gametocyte prevalence but its contribution was small. CONCLUSIONS: The existence of a significant human genetic contribution to gametocyte prevalence in asymptomatic infections suggests that candidate gene and genome wide association approaches may be usefully applied to explore the underlying human genetics. Prospective epidemiological studies will provide an opportunity to generate novel and perhaps more epidemiologically pertinent gametocyte data with which similar analyses can be performed and the role of human genetics in parasite transmission ascertained.

The landscape of human genes involved in the immune response to parasitic worms

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Fumagalli Matteo

2010-08-01

Full Text Available Abstract Background More than 2 billion individuals worldwide suffer from helminth infections. The highest parasite burdens occur in children and helminth infection during pregnancy is a risk factor for preterm delivery and reduced birth weight. Therefore, helminth infections can be regarded as a strong selective pressure. Results Here we propose that candidate susceptibility genes for parasitic worm infections can be identified by searching for SNPs that display a strong correlation with the diversity of helminth species/genera transmitted in different geographic areas. By a genome-wide search we identified 3478 variants that correlate with helminth diversity. These SNPs map to 810 distinct human genes including loci involved in regulatory T cell function and in macrophage activation, as well as leukocyte integrins and co-inhibitory molecules. Analysis of functional relationships among these genes identified complex interaction networks centred around Th2 cytokines. Finally, several genes carrying candidate targets for helminth-driven selective pressure also harbour susceptibility alleles for asthma/allergy or are involved in airway hyper-responsiveness, therefore expanding the known parallelism between these conditions and parasitic infections. Conclusions Our data provide a landscape of human genes that modulate susceptibility to helminths and indicate parasitic worms as one of the major selective forces in humans.

Filarial-specific antibody response in East African bancroftian filariasis: effects of host infection, clinical disease, and filarial endemicity

DEFF Research Database (Denmark)

Jaoko, Walter G; Simonsen, Paul E; Meyrowitsch, Dan W

2006-01-01

bancrofti endemicity. In the high endemicity community, intensities of the measured antibodies were significantly associated with infection status. IgG1, IgG2, and IgE were negatively associated with microfilaria (MF) status, IgG3 was negatively associated with circulating filarial antigen (CFA) status......, and IgG4 was positively associated with CFA status. None of the associations were significantly influenced by chronic lymphatic disease status. In contrast, IgG1, IgG2, and IgG4 responses were less vigorous in the low endemicity community and, except for IgG4, did not show any significant associations...... with MF or CFA status. The IgG3 responses were considerably more vigorous in the low endemicity community than in the high endemicity one. Only IgG4 responses exhibited a rather similar pattern in the two communities, being significantly positively associated with CFA status in both communities. The IgG4...

Epidemiological assessment of neglected diseases in children: lymphatic filariasis and soil-transmitted helminthiasis

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Ana M. Aguiar-Santos

2013-05-01

Full Text Available Objective: To report the prevalence of lymphatic filariasis and intestinal parasitic infections in school-aged children living in a filariasis endemic area and discuss about the therapeutic regimen adopted in Brazil for the large-scale treatment of filariasis. Methods: A cross-sectional study including 508 students aged 5-18 years old, enrolled in public schools within the city of Olinda, Pernambuco. The presence of intestinal parasites was analyzed using the Hoffman, Pons and Janer method on 3 stool samples. The diagnosis of filarial infection was performed using the rapid immunochromatographic technique (ICT for the antigen, and the polycarbonate membrane filtration for the presence of microfilariae. Descriptive statistics of the data was performed using EpiInfo version 7. Results: The prevalence of filariasis was 13.8% by ICT and 1.2% by microfilaraemia, while intestinal parasites were detected in 64.2% of cases. Concurrent diagnosis of filariasis and intestinal parasites was 9.4%, while 31.5% of students were parasite-free. Among individuals with intestinal parasites, 55% had one parasite and 45% had more than one parasite. Geohelminths occurred in 72.5% of the parasited individuals. In the group with filarial infection the prevalence of soil-transmitted helminthiasis was 54.5%. Conclusions: The simultaneous diagnosis of filariasis and intestinal parasites as well as the high frequency of geohelminths justify the need to reevaluate the treatment strategy used in the Brazilian filariasis large-scale treatment program. Resumo: Objetivo: Descrever a prevalência de infecção filarial e de parasitoses intestinais em escolares numa área endêmica de filariose e refletir sobre a opção terapêutica utilizada no Brasil no tratamento coletivo para filariose. Métodos: Estudo transversal envolvendo 508 alunos na faixa etária de 5-18 anos cadastrados em escolas públicas do município de Olinda-PE. Realizou-se a investigação da parasitose

Morphological and Molecular Descriptors of the Developmental Cycle of Babesia divergens Parasites in Human Erythrocytes.

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Ingrid Rossouw

2015-05-01

Full Text Available Human babesiosis, especially caused by the cattle derived Babesia divergens parasite, is on the increase, resulting in renewed attentiveness to this potentially life threatening emerging zoonotic disease. The molecular mechanisms underlying the pathophysiology and intra-erythrocytic development of these parasites are poorly understood. This impedes concerted efforts aimed at the discovery of novel anti-babesiacidal agents. By applying sensitive cell biological and molecular functional genomics tools, we describe the intra-erythrocytic development cycle of B. divergens parasites from immature, mono-nucleated ring forms to bi-nucleated paired piriforms and ultimately multi-nucleated tetrads that characterizes zoonotic Babesia spp. This is further correlated for the first time to nuclear content increases during intra-erythrocytic development progression, providing insight into the part of the life cycle that occurs during human infection. High-content temporal evaluation elucidated the contribution of the different stages to life cycle progression. Moreover, molecular descriptors indicate that B. divergens parasites employ physiological adaptation to in vitro cultivation. Additionally, differential expression is observed as the parasite equilibrates its developmental stages during its life cycle. Together, this information provides the first temporal evaluation of the functional transcriptome of B. divergens parasites, information that could be useful in identifying biological processes essential to parasite survival for future anti-babesiacidal discoveries.

Genome sequencing of chimpanzee malaria parasites reveals possible pathways of adaptation to human hosts

KAUST Repository

Otto, Thomas D.

2014-09-09

Plasmodium falciparum causes most human malaria deaths, having prehistorically evolved from parasites of African Great Apes. Here we explore the genomic basis of P. falciparum adaptation to human hosts by fully sequencing the genome of the closely related chimpanzee parasite species P. reichenowi, and obtaining partial sequence data from a more distantly related chimpanzee parasite (P. gaboni). The close relationship between P. reichenowi and P. falciparum is emphasized by almost complete conservation of genomic synteny, but against this strikingly conserved background we observe major differences at loci involved in erythrocyte invasion. The organization of most virulence-associated multigene families, including the hypervariable var genes, is broadly conserved, but P. falciparum has a smaller subset of rif and stevor genes whose products are expressed on the infected erythrocyte surface. Genome-wide analysis identifies other loci under recent positive selection, but a limited number of changes at the host–parasite interface may have mediated host switching.

Targeting NAD+ metabolism in the human malaria parasite Plasmodium falciparum.

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Jessica K O'Hara

Full Text Available Nicotinamide adenine dinucleotide (NAD+ is an essential metabolite utilized as a redox cofactor and enzyme substrate in numerous cellular processes. Elevated NAD+ levels have been observed in red blood cells infected with the malaria parasite Plasmodium falciparum, but little is known regarding how the parasite generates NAD+. Here, we employed a mass spectrometry-based metabolomic approach to confirm that P. falciparum lacks the ability to synthesize NAD+ de novo and is reliant on the uptake of exogenous niacin. We characterized several enzymes in the NAD+ pathway and demonstrate cytoplasmic localization for all except the parasite nicotinamidase, which concentrates in the nucleus. One of these enzymes, the P. falciparum nicotinate mononucleotide adenylyltransferase (PfNMNAT, is essential for NAD+ metabolism and is highly diverged from the human homolog, but genetically similar to bacterial NMNATs. Our results demonstrate the enzymatic activity of PfNMNAT in vitro and demonstrate its ability to genetically complement the closely related Escherichia coli NMNAT. Due to the similarity of PfNMNAT to the bacterial enzyme, we tested a panel of previously identified bacterial NMNAT inhibitors and synthesized and screened twenty new derivatives, which demonstrate a range of potency against live parasite culture. These results highlight the importance of the parasite NAD+ metabolic pathway and provide both novel therapeutic targets and promising lead antimalarial compounds.

Natural infection of Plasmodium brasilianum in humans: Man and monkey share quartan malaria parasites in the Venezuelan Amazon.

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Lalremruata, Albert; Magris, Magda; Vivas-Martínez, Sarai; Koehler, Maike; Esen, Meral; Kempaiah, Prakasha; Jeyaraj, Sankarganesh; Perkins, Douglas Jay; Mordmüller, Benjamin; Metzger, Wolfram G

2015-09-01

The quartan malaria parasite Plasmodium malariae is the widest spread and best adapted human malaria parasite. The simian Plasmodium brasilianum causes quartan fever in New World monkeys and resembles P. malariae morphologically. Since the genetics of the two parasites are nearly identical, differing only in a range of mutations expected within a species, it has long been speculated that the two are the same. However, no naturally acquired infection with parasites termed as P. brasilianum has been found in humans until now. We investigated malaria cases from remote Yanomami indigenous communities of the Venezuelan Amazon and analyzed the genes coding for the circumsporozoite protein (CSP) and the small subunit of ribosomes (18S) by species-specific PCR and capillary based-DNA sequencing. Based on 18S rRNA gene sequencing, we identified 12 patients harboring malaria parasites which were 100% identical with P. brasilianum isolated from the monkey, Alouatta seniculus. Translated amino acid sequences of the CS protein gene showed identical immunodominant repeat units between quartan malaria parasites isolated from both humans and monkeys. This study reports, for the first time, naturally acquired infections in humans with parasites termed as P. brasilianum. We conclude that quartan malaria parasites are easily exchanged between humans and monkeys in Latin America. We hypothesize a lack of host specificity in mammalian hosts and consider quartan malaria to be a true anthropozoonosis. Since the name P. brasilianum suggests a malaria species distinct from P. malariae, we propose that P. brasilianum should have a nomenclatorial revision in case further research confirms our findings. The expansive reservoir of mammalian hosts discriminates quartan malaria from other Plasmodium spp. and requires particular research efforts.

Social Parasites

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Lopez, Miguel A.; Nguyen, HoangKim T.; Oberholzer, Michael; Hill, Kent L.

2011-01-01

Summary of recent advances Protozoan parasites cause tremendous human suffering worldwide, but strategies for therapeutic intervention are limited. Recent studies illustrate that the paradigm of microbes as social organisms can be brought to bear on questions about parasite biology, transmission and pathogenesis. This review discusses recent work demonstrating adaptation of social behaviors by parasitic protozoa that cause African sleeping sickness and malaria. The recognition of social behavior and cell-cell communication as a ubiquitous property of bacteria has transformed our view of microbiology, but protozoan parasites have not generally been considered in this context. Works discussed illustrate the potential for concepts of sociomicrobiology to provide insight into parasite biology and should stimulate new approaches for thinking about parasites and parasite-host interactions. PMID:22020108

Recent Advances on the Use of Biochemical Extracts as Filaricidal Agents

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Nazeh M. Al-Abd

2013-01-01

Full Text Available 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.

[Current situation of human resources of parasitic disease control and prevention organizations in Henan Province].

Science.gov (United States)

Ya-Lan, Zhang; Yan-Kun, Zhu; Wei-Qi, Chen; Yan, Deng; Peng, Li

2018-01-10

To understand the current status of human resources of parasitic disease control and prevention organizations in Henan Province, so as to provide the reference for promoting the integrative ability of the prevention and control of parasitic diseases in Henan Province. The questionnaires were designed and the method of census was adopted. The information, such as the amounts, majors, education background, technical titles, working years, and turnover in each parasitic disease control and prevention organization was collected by the centers for disease control and prevention (CDCs) at all levels. The data were descriptively analyzed. Totally 179 CDCs were investigated, in which only 19.0% (34/179) had the independent parasitic diseases control institution (department) . There were only 258 full-time staffs working on parasitic disease control and prevention in the whole province, in which only 61.9% (159/258) were health professionals. Those with junior college degree or below in the health professionals accounted for 60.3% (96/159) . Most of them (42.1%) had over 20 years of experience, but 57.9% (92/159) of their technical post titles were at primary level or below. The proportion of the health professionals is low in the parasitic disease control and prevention organizations in Henan Province. The human resource construction for parasitic disease control and prevention at all levels should be strengthened.

Proteins involved in invasion of human red blood cells by malaria parasites

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Ewa Jaśkiewicz

2010-11-01

Full Text Available Malaria is a disease caused by parasites of Plasmodium species. It is responsible for around 1-2 million deaths annually, mainly children under the age of 5. It occurs mainly in tropical and subtropical areas.Malaria is caused by five Plasmodium species:[i] P. falciparum, P. malariae, P. vivax, P. knowlesi[/i] and [i]P. ovale[/i]. Mosquitoes spread the disease by biting humans. The malaria parasite has two stages of development: the human stage and the mosquito stage. The first stage occurs in the human body and is divided into two phases: the liver phase and the blood phase.The invasion of erythrocytes by [i]Plasmodium[/i] merozoites is a multistep process of specific protein interactions between the parasite and red blood cell. The first step is the reversible merozoite attachment to the erythrocyte followed by its apical reorientation, then formation of an irreversible “tight” junction and finally entry into the red cell in a parasitophorous vacuole.The blood phase is supported by a number of proteins produced by the parasite. The merozoite surface GPI-anchored proteins (MSP-1, 2, 4, 5, 8 and 10 assist in the process of recognition of susceptible erythrocytes, apical membrane antigen (AMA-1 may be directly responsible for apical reorientation of the merozoite and apical proteins which function in tight junction formation. These ligands are members of two families: Duffy binding-like (DBL and reticulocyte binding-like (RBL proteins. In [i]Plasmodium[/i] [i]falciparum[/i] the DBL family includes: EBA-175, EBA-140 (BAEBL, EBA-181 (JESEBL, EBA-165 (PEBL and EBL-1 ligands.To date, no effective antimalarial vaccine has been developed, but there are several studies for this purpose. Therefore, it is crucial to understand the molecular basis of host cells invasion by parasites. Major efforts are focused on developing a multiantigenic and multiepitope vaccine preventing all steps of [i]Plasmodium[/i] invasion.

Analysis of a summary network of co-infection in humans reveals that parasites interact most via shared resources

OpenAIRE

Griffiths, Emily C; Pedersen, Amy B; Fenton, Andy; Petchey, Owen L

2014-01-01

Simultaneous infection by multiple parasite species (viruses, bacteria, helminths, protozoa or fungi) is commonplace. Most reports show co-infected humans to have worse health than those with single infections. However, we have little understanding of how co-infecting parasites interact within human hosts. We used data from over 300 published studies to construct a network that offers the first broad indications of how groups of co-infecting parasites tend to interact. The network had three l...

The prevalence and diversity of intestinal parasitic infections in humans and domestic animals in a rural Cambodian village

DEFF Research Database (Denmark)

Schär, Fabian; Inpankaew, Tawin; Traub, Rebecca J.

2014-01-01

In Cambodia, intestinal parasitic infections are prevalent in humans and particularly in children. Yet, information on potentially zoonotic parasites in animal reservoir hosts is lacking. In May 2012, faecal samples from 218 humans, 94 dogs and 76 pigs were collected from 67 households in Dong vi...

Human presence increases parasitic load in endangered lion-tailed macaques (Macaca silenus in its fragmented rainforest habitats in Southern India.

Directory of Open Access Journals (Sweden)

Shaik Hussain

Full Text Available BACKGROUND: Understanding changes in the host-parasite relationship due to habitat fragmentation is necessary for better management and conservation of endangered species in fragmented landscapes. Pathogens and parasites can pose severe threat to species in restricted environments such as forest fragments where there is increased contact of wildlife with human and livestock populations. Environmental stress and reduced nutritional level in forest fragments can influence parasite infection and intensity on the native species. In this study, we examine the impact of habitat fragmentation on the prevalence of gastrointestinal parasites in lion-tailed macaques in a fragmented rainforest in Western Ghats. METHODS: The prevalence of different gastrointestinal parasites was estimated from 91 fecal samples collected from 9 lion-tailed macaque groups in nine forest fragments. The parasites were identified up to genus level on the basis of the morphology and coloration of the egg, larva and cyst. The covariates included forest fragment area, group size and the presence/absence of human settlements and livestock in proximity. We used a linear regression model to identify the covariates that significantly influenced the prevalence of different parasite taxa. RESULTS: Nine gastrointestinal parasite taxa were detected in lion-tailed macaque groups. The groups near human settlements had greater prevalence and number of taxa, and these variables also had significant positive correlations with group size. We found that these parameters were also greater in groups near human settlements after controlling for group size. Livestock were present in all five fragments that had human settlements in proximity. CONCLUSION: The present study suggests that high prevalence and species richness of gastrointestinal parasites in lion-tailed macaque groups are directly related to habitat fragmentation, high anthropogenic activities and high host density. The parasite load

Survey of the parasite Toxoplasma gondii in human consumed ovine meat in Tunis City.

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Sonia Boughattas

Full Text Available Toxoplasmosis has been recognized as parasitic zoonosis with the highest human incidence. The human infection by the parasite can lead to severe clinical manifestations in congenital toxoplasmosis and immunocompromised patients. Contamination occurs mainly by foodborne ways especially consumption of raw or undercooked meat. In contrast to other foodborne infections, toxoplasmosis is a chronic infection which would make its economic and social impact much higher than even previously anticipated. Ovine meat was advanced as a major risk factor, so we investigated its parasite survey, under natural conditions. Serological MAT technique and touchdown PCR approaches were used for prevalence determination of the parasite in slaughtered sheep intended to human consumption in Tunis City. The genotyping was carried by SNPs analysis of SAG3 marker. Anti-Toxoplasma antibodies were present in 38.2% of young sheep and in 73.6% of adult sheep. Molecular detection revealed the contamination of 50% of ewes' tissue. Sequencing and SNPs analysis enabled unambiguous typing of meat isolates and revealed the presence of mixed strains as those previously identified from clinical samples in the same area. Our findings conclude that slaughtered sheep are highly infected, suggesting them as a major risk factor of Toxoplasma gondii transmission by meat consumption. Special aware should target consequently this factor when recommendations have to be established by the health care commanders.

Foodborne parasites from wildlife

DEFF Research Database (Denmark)

Kapel, Christian Moliin Outzen; Fredensborg, Brian Lund

2015-01-01

The majority of wild foods consumed by humans are sourced from intensively managed or semi-farmed populations. Management practices inevitably affect wildlife density and habitat characteristics, which are key elements in the transmission of parasites. We consider the risk of transmission...... of foodborne parasites to humans from wildlife maintained under natural or semi-natural conditions. A deeper understanding will be useful in counteracting foodborne parasites arising from the growing industry of novel and exotic foods....

Parasites and cancers: parasite antigens as possible targets for cancer immunotherapy.

Science.gov (United States)

Darani, Hossein Yousofi; Yousefi, Morteza

2012-12-01

An adverse relationship between some parasite infections and cancer in the human population has been reported by different research groups. Anticancer activity of some parasites such as Trypanosoma cruzi, Toxoplasma gondii, Toxocara canis, Acantamoeba castellani and Plasmodium yoelii has been shown in experimental animals. Moreover, it has been shown that cancer-associated mucin-type O-glycan compositions are made by parasites, therefore cancers and parasites have common antigens. In this report anticancer activities of some parasites have been reviewed and the possible mechanisms of these actions have also been discussed.

Dichotomy in the human CD4⁺ T-cell response to Leishmania parasites

DEFF Research Database (Denmark)

Kemp, M; Kurtzhals, J A; Kharazmi, A

1994-01-01

Leishmania parasites cause human diseases ranging from self-healing cutaneous ulcers to fatal systemic infections. In addition, many individuals become infected without developing disease. In mice the two subsets of CD4+ T cells, Th1 and Th2, have different effects on the outcome of experimental...... in humans, and that the balance between subsets of parasite-specific T cells may play an important regulatory role in determining the outcome of the infections....

Quantitation of parasite-specific human IgG and IgE in sera: evaluation of solid-phase RIA and ELISA methodology

Energy Technology Data Exchange (ETDEWEB)

Hamilton, R G [Johns Hopkins Univ., Baltimore, MD (USA). Dept. of Medicine; Hussain, R; Ottesen, E A [National Inst. of Allergy and Infectious Diseases, Bethesda, MD (USA); Adkinson, Jr, N F [Johns Hopkins Univ., Baltimore, MD (USA). School of Medicine

1981-07-17

The authors have developed a non-competitive solid-phase radioimmunoassay (SPRIA) to quantitate both human IgE and IgG antibodies against soluble adult antigens of Brugia malayi (B.m.), a filarial parasite causing extensive infection throughout the tropics. Previously enzyme-linked immunosorbent assays (ELISA) had been used to detect ..mu..g/ml levels of IgG anti-B.m., but IgE antibodies were difficult to detect in this system. Since the SPRIA successfully quantitates both IgG and IgE anti-B.m., they sought to examine the reasons for the SPRIA's apparent superiority in detecting IgE anti-B.m. by extracting specific IgG from sera with high levels of IgE and IgG anti-B.m. antibodies. IgE anti-B.m. was then quantitated in these sera using both the SPRIA and ELISA methods. Results indicate that IgG anti-B.m. does not interfere with detection of specific IgE antibody in the SPRIA but does interfere in the ELISA. While ELISA permits detection of IgE anti-B.m. in the absence of competing IgG anti-B.m., as levels of specific IgG increase, the IgE is no longer detectable. These differences between SPRIA and ELISA can be explained by the SPRIA's antigen excess conditions which assure that there are sufficient antigens both to detect all anti-B.m. antibodies present in the serum and to adequately represent all antigen specificities in the crude B.m. extract. Their findings commend the use of SPRIA methods over ELISA in assessment of B.m.-specific IgE antibody in filariasis and indicate a potential role for SPRIA methods in absolute quantitation of specific serum antibodies.

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

Science.gov (United States)

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.

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

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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.

In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome.

Science.gov (United States)

Liu, Xuewu; Wang, Yuanyuan; Liang, Jiao; Wang, Luojun; Qin, Na; Zhao, Ya; Zhao, Gang

2018-05-02

Plasmodium falciparum is the most virulent malaria parasite capable of parasitizing human erythrocytes. The identification of genes related to this capability can enhance our understanding of the molecular mechanisms underlying human malaria and lead to the development of new therapeutic strategies for malaria control. With the availability of several malaria parasite genome sequences, performing computational analysis is now a practical strategy to identify genes contributing to this disease. Here, we developed and used a virtual genome method to assign 33,314 genes from three human malaria parasites, namely, P. falciparum, P. knowlesi and P. vivax, and three rodent malaria parasites, namely, P. berghei, P. chabaudi and P. yoelii, to 4605 clusters. Each cluster consisted of genes whose protein sequences were significantly similar and was considered as a virtual gene. Comparing the enriched values of all clusters in human malaria parasites with those in rodent malaria parasites revealed 115 P. falciparum genes putatively responsible for parasitizing human erythrocytes. These genes are mainly located in the chromosome internal regions and participate in many biological processes, including membrane protein trafficking and thiamine biosynthesis. Meanwhile, 289 P. berghei genes were included in the rodent parasite-enriched clusters. Most are located in subtelomeric regions and encode erythrocyte surface proteins. Comparing cluster values in P. falciparum with those in P. vivax and P. knowlesi revealed 493 candidate genes linked to virulence. Some of them encode proteins present on the erythrocyte surface and participate in cytoadhesion, virulence factor trafficking, or erythrocyte invasion, but many genes with unknown function were also identified. Cerebral malaria is characterized by accumulation of infected erythrocytes at trophozoite stage in brain microvascular. To discover cerebral malaria-related genes, fast Fourier transformation (FFT) was introduced to extract

The prevalence and diversity of intestinal parasitic infections in humans and domestic animals in a rural Cambodian village.

Science.gov (United States)

Schär, Fabian; Inpankaew, Tawin; Traub, Rebecca J; Khieu, Virak; Dalsgaard, Anders; Chimnoi, Wissanuwat; Chhoun, Chamnan; Sok, Daream; Marti, Hanspeter; Muth, Sinuon; Odermatt, Peter

2014-08-01

In Cambodia, intestinal parasitic infections are prevalent in humans and particularly in children. Yet, information on potentially zoonotic parasites in animal reservoir hosts is lacking. In May 2012, faecal samples from 218 humans, 94 dogs and 76 pigs were collected from 67 households in Dong village, Preah Vihear province, Cambodia. Faecal samples were examined microscopically using sodium nitrate and zinc sulphate flotation methods, the Baermann method, Koga Agar plate culture, formalin-ether concentration technique and Kato Katz technique. PCR was used to confirm hookworm, Ascaris spp., Giardia spp. and Blastocystis spp. Major gastrointestinal parasitic infections found in humans included hookworms (63.3%), Entamoeba spp. (27.1%) and Strongyloides stercoralis (24.3%). In dogs, hookworm (80.8%), Spirometra spp. (21.3%) and Strongyloides spp. (14.9%) were most commonly detected and in pigs Isospora suis (75.0%), Oesophagostomum spp. (73.7%) and Entamoeba spp. (31.6%) were found. Eleven parasite species were detected in dogs (eight helminths and three protozoa), seven of which have zoonotic potential, including hookworm, Strongyloides spp., Trichuris spp., Toxocara canis, Echinostoma spp., Giardia duodenalis and Entamoeba spp. Five of the parasite species detected in pigs also have zoonotic potential, including Ascaris spp., Trichuris spp., Capillaria spp., Balantidium coli and Entamoeba spp. Further molecular epidemiological studies will aid characterisation of parasite species and genotypes and allow further insight into the potential for zoonotic cross transmission of parasites in this community. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

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

Science.gov (United States)

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.

Pets and Parasites

Science.gov (United States)

... good news is that this rarely happens. Most pet-to-people diseases can be avoided by following a few ... your doctor Can a parasite cause death in people and pets? Can human disease from a parasite be treated ...

Fishing drives declines in fish parasite diversity and has variable effects on parasite abundance.

Science.gov (United States)

Wood, Chelsea L; Sandin, Stuart A; Zgliczynski, Brian; Guerra, Ana Sofía; Micheli, Fiorenza

2014-07-01

Despite the ubiquity and ecological importance of parasites, relatively few studies have assessed their response to anthropogenic environmental change. Heuristic models have predicted both increases and decreases in parasite abundance in response to human disturbance, with empirical support for both. However, most studies focus on one or a few selected parasite species. Here, we assess the abundance of parasites of seven species of coral reef fishes collected from three fished and three unfished islands of the Line Islands archipelago in the central equatorial Pacific. Because we chose fish hosts that spanned different trophic levels, taxonomic groups, and body sizes, we were able to compare parasite responses across a broad cross section of the total parasite community in the presence and absence of fishing, a major human impact on marine ecosystems. We found that overall parasite species richness was substantially depressed on fished islands, but that the response of parasite abundance varied among parasite taxa: directly transmitted parasites were significantly more abundant on fished than on unfished islands, while the reverse was true for trophically transmitted parasites. This probably arises because trophically transmitted parasites require multiple host species, some of which are the top predators most sensitive to fishing impacts. The increase in directly transmitted parasites appeared to be due to fishing-driven compensatory increases in the abundance of their hosts. Together, these results provide support for the predictions of both heuristic models, and indicate that the direction of fishing's impact on parasite abundance is mediated by parasite traits, notably parasite transmission strategies.

Human waterborne parasites in zebra mussels ( Dreissena polymorpha) from the Shannon River drainage area, Ireland.

Science.gov (United States)

Graczyk, Thaddeus K; Conn, David Bruce; Lucy, Frances; Minchin, Dan; Tamang, Leena; Moura, Lacy N S; DaSilva, Alexandre J

2004-08-01

Zebra mussels ( Dreissena polymorpha) from throughout the Shannon River drainage area in Ireland were tested for the anthropozoonotic waterborne parasites Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, E. hellem, and Enterocytozoon bieneusi, by the multiplexed combined direct immunofluorescent antibody and fluorescent in situ hybridization method, and PCR. Parasite transmission stages were found at 75% of sites, with the highest mean concentration of 16, nine, and eight C. parvum oocysts, G. lamblia cysts, and Encephalitozoon intestinalis spores/mussel, respectively. On average eight Enterocytozoon bieneusi spores/mussel were recovered at any selected site. Approximately 80% of all parasites were viable and thus capable of initiating human infection. The Shannon River is polluted with serious emerging human waterborne pathogens including C. parvum, against which no therapy exists. Zebra mussels can recover and concentrate environmentally derived pathogens and can be used for the sanitary assessment of water quality.

Studies on the role of irradiated filarial parasites in inducing immunoprophylaxis against experimental filariasis. Part of a coordinated programme on the use of nuclear techniques in the preparation of vaccines against parasitic diseases

International Nuclear Information System (INIS)

Subrahamaniam, D.

1979-01-01

The effect of ionizing radiation at various doses on the growth of Litomosoides carinii infective third stage larvae and on the protection conferred by such larvae against filarial infections was studied in albino rats. At radiation doses of 30 K rads and below the larvae developed into adults in retarded and sterile forms. No such development was seen when the larvae were irradiated at doses of 38 K rads and above. A high degree of protection was observed when the animals were immunized with 3 doses of infective larvae attenuated with 38 or 40 K rads of radiation. This degree of protection was not observed with larvae irradiated at other dose levels nor when the number of immunizations were reduced to two. The concurrent injection with heat killed Coryne-bacterium parva at immunization increased the level of protection. This was not observed when the C. parva organisms were replaced with Freunds Complete Adjuvant. Protection was best demonstrated when the challenge was given more than 30 days following the last immunization. The immunized animals showed the presence of serum dependent cellular adhesion to microfilarial and this correlated well with protection

Molecular characterisation of protist parasites in human-habituated mountain gorillas (Gorilla beringei beringei), humans and livestock, from Bwindi impenetrable National Park, Uganda.

Science.gov (United States)

Nolan, Matthew J; Unger, Melisa; Yeap, Yuen-Ting; Rogers, Emma; Millet, Ilary; Harman, Kimberley; Fox, Mark; Kalema-Zikusoka, Gladys; Blake, Damer P

2017-07-18

Over 60 % of human emerging infectious diseases are zoonotic, and there is growing evidence of the zooanthroponotic transmission of diseases from humans to livestock and wildlife species, with major implications for public health, economics, and conservation. Zooanthroponoses are of relevance to critically endangered species; amongst these is the mountain gorilla (Gorilla beringei beringei) of Uganda. Here, we assess the occurrence of Cryptosporidium, Cyclospora, Giardia, and Entamoeba infecting mountain gorillas in the Bwindi Impenetrable National Park (BINP), Uganda, using molecular methods. We also assess the occurrence of these parasites in humans and livestock species living in overlapping/adjacent geographical regions. Diagnostic PCR detected Cryptosporidium parvum in one sample from a mountain gorilla (IIdA23G2) and one from a goat (based on SSU). Cryptosporidium was not detected in humans or cattle. Cyclospora was not detected in any of the samples analysed. Giardia was identified in three human and two cattle samples, which were linked to assemblage A, B and E of G. duodenalis. Sequences defined as belonging to the genus Entamoeba were identified in all host groups. Of the 86 sequence types characterised, one, seven and two have been recorded previously to represent genotypes of Cryptosporidium, Giardia, and Entamoeba, respectively, from humans, other mammals, and water sources globally. This study provides a snapshot of the occurrence and genetic make-up of selected protists in mammals in and around BINP. The genetic analyses indicated that 54.6% of the 203 samples analysed contained parasites that matched species, genotypes, or genetic assemblages found globally. Seventy-six new sequence records were identified here for the first time. As nothing is known about the zoonotic/zooanthroponotic potential of the corresponding parasites, future work should focus on wider epidemiological investigations together with continued surveillance of all parasites in

The quantitation of parasite-specific human IgG and IgE in sera: evaluation of solid-phase RIA and ELISA methodology

International Nuclear Information System (INIS)

Hamilton, R.G.; Adkinson, N.F. Jr.

1981-01-01

The authors have developed a non-competitive solid-phase radioimmunoassay (SPRIA) to quantitate both human IgE and IgG antibodies against soluble adult antigens of Brugia malayi (B.m.), a filarial parasite causing extensive infection throughout the tropics. Previously enzyme-linked immunosorbent assays (ELISA) had been used to detect μg/ml levels of IgG anti-B.m., but IgE antibodies were difficult to detect in this system. Since the SPRIA successfully quantitates both IgG and IgE anti-B.m., they sought to examine the reasons for the SPRIA's apparent superiority in detecting IgE anti-B.m. by extracting specific IgG from sera with high levels of IgE and IgG anti-B.m. antibodies. IgE anti-B.m. was then quantitated in these sera using both the SPRIA and ELISA methods. Results indicate that IgG anti-B.m. does not interfere with detection of specific IgE antibody in the SPRIA but does interfere in the ELISA. While ELISA permits detection of IgE anti-B.m. in the absence of competing IgG anti-B.m., as levels of specific IgG increase, the IgE is no longer detectable. These differences between SPRIA and ELISA can be explained by the SPRIA's antigen excess conditions which assure that there are sufficient antigens both to detect all anti-B.m. antibodies present in the serum and to adequately represent all antigen specificities in the crude B.m. extract. Their findings commend the use of SPRIA methods over ELISA in assessment of B.m.-specific IgE antibody in filariasis and indicate a potential role for SPRIA methods in absolute quantitation of specific serum antibodies. (Auth.)

Epidemiology of infections with intestinal parasites and human immunodeficiency virus (HIV) among sugar-estate residents in Ethiopia

NARCIS (Netherlands)

Fontanet, A. L.; Sahlu, T.; Rinke de Wit, T.; Messele, T.; Masho, W.; Woldemichael, T.; Yeneneh, H.; Coutinho, R. A.

2000-01-01

Intestinal parasitic infections could play an important role in the progression of infection with human immunodeficiency virus (HIV), by further disturbing the immune system whilst it is already engaged in the fight against HIV. HIV and intestinal parasitic infections were investigated in 1239,

Look what the cat dragged in: do parasites contribute to human cultural diversity?

Science.gov (United States)

Lafferty, Kevin D.

2005-01-01

If human culture emerges from the modal personality of a population, can global variation in parasitism that affects personality lead to cultural diversity among nations? The answer could help explain why people seem to vary so much from one land to another. Thomas et al. (2005) review how parasites manipulate behaviour, including human behaviour. To quote them, “The rabies virus lives in the brain, affording the virus ample opportunity to directly affect host behaviour. Rabid animals do show changes in behaviour, including increased aggression and biting.” Rabies affects a wide range of mammals and the aggressive biting associated with furious rabies appears to increase transmission. The personality transformation of infected humans can be horrifying, transforming loved ones into thrashing, baying beasts. Not coincidentally, in Europe, past periods of rabies outbreaks correspond to increases in werewolf trials. Although rabies can have a dramatic effect, the present rarity of human rabies cases and the availability of a vaccine, means that the behavioural effects of rabies are primarily an illustrative curiosity.

Filariasis attenuates anemia and proinflammatory responses associated with clinical malaria: a matched prospective study in children and young adults.

Directory of Open Access Journals (Sweden)

Housseini Dolo

Full Text Available Wuchereria bancrofti (Wb and Mansonella perstans (Mp are blood-borne filarial parasites that are endemic in many countries of Africa, including Mali. The geographic distribution of Wb and Mp overlaps considerably with that of malaria, and coinfection is common. Although chronic filarial infection has been shown to alter immune responses to malaria parasites, its effect on clinical and immunologic responses in acute malaria is unknown.To address this question, 31 filaria-positive (FIL+ and 31 filaria-negative (FIL- children and young adults, matched for age, gender and hemoglobin type, were followed prospectively through a malaria transmission season. Filarial infection was defined by the presence of Wb or Mp microfilariae on calibrated thick smears performed between 10 pm and 2 am and/or by the presence of circulating filarial antigen in serum. Clinical malaria was defined as axillary temperature ≥37.5°C or another symptom or sign compatible with malaria infection plus the presence of asexual malaria parasites on a thick blood smear. Although the incidence of clinical malaria, time to first episode, clinical signs and symptoms, and malaria parasitemia were comparable between the two groups, geometric mean hemoglobin levels were significantly decreased in FIL- subjects at the height of the transmission season compared to FIL+ subjects (11.4 g/dL vs. 12.5 g/dL, p<0.01. Plasma levels of IL-1ra, IP-10 and IL-8 were significantly decreased in FIL+ subjects at the time of presentation with clinical malaria (99, 2145 and 49 pg/ml, respectively as compared to 474, 5522 and 247 pg/ml in FIL- subjects.These data suggest that pre-existent filarial infection attenuates immune responses associated with severe malaria and protects against anemia, but has little effect on susceptibility to or severity of acute malaria infection. The apparent protective effect of filarial infection against anemia is intriguing and warrants further study in a larger cohort.

Cytometric quantification of singlet oxygen in the human malaria parasite Plasmodium falciparum

NARCIS (Netherlands)

Butzloff, Sabine; Groves, Matthew R; Wrenger, Carsten; Müller, Ingrid B

The malaria parasite Plasmodium falciparum proliferates within human erythrocytes and is thereby exposed to a variety of reactive oxygen species (ROS) such as hydrogen peroxide, hydroxyl radical, superoxide anion, and highly reactive singlet oxygen ((1)O(2)). While most ROS are already well studied

Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species

Directory of Open Access Journals (Sweden)

Andrea Springer

2015-12-01

Full Text Available Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi, as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites.

Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species.

Science.gov (United States)

Springer, Andrea; Fichtel, Claudia; Calvignac-Spencer, Sébastien; Leendertz, Fabian H; Kappeler, Peter M

2015-12-01

Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi), as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites.

Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species☆

Science.gov (United States)

Springer, Andrea; Fichtel, Claudia; Calvignac-Spencer, Sébastien; Leendertz, Fabian H.; Kappeler, Peter M.

2015-01-01

Hemoparasites can cause serious morbidity in humans and animals and often involve wildlife reservoirs. Understanding patterns of hemoparasite infections in natural populations can therefore inform about emerging disease risks, especially in the light of climate change and human disruption of natural ecosystems. We investigated the effects of host age, sex, host group size and season on infection patterns of Plasmodium sp., Babesia sp. and filarial nematodes in a population of wild Malagasy primates, Verreaux's sifakas (Propithecus verreauxi), as well as the effects of these infections on hematological variables. We tested 45 blood samples from 36 individuals and identified two species of Plasmodium, one species of Babesia and two species of filarial nematodes. Plasmodium spp. and Babesia sp. infections showed opposite patterns of age-dependency, with babesiosis being prevalent among young animals, while older animals were infected with Plasmodium sp. In addition, Babesia sp. infection was a statistically significant negative predictor of Plasmodium sp. infection. These results suggest that Plasmodium and Babesia parasites may interact within the host, either through cross-immunity or via resource competition, so that Plasmodium infections can only establish after babesiosis has resolved. We found no effects of host sex, host group size and season on hemoparasite infections. Infections showed high prevalences and did not influence hematological variables. This preliminary evidence supports the impression that the hosts and parasites considered in this study appear to be well-adapted to each other, resulting in persistent infections with low pathogenic and probably low zoonotic potential. Our results illustrate the crucial role of biodiversity in host-parasite relationships, specifically how within-host pathogen diversity may regulate the abundance of parasites. PMID:26767166

Genetic characterization of human-pathogenic Cyclospora cayetanensis parasites from three endemic regions at the 18S ribosomal RNA locus.

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Sulaiman, Irshad M; Ortega, Ynes; Simpson, Steven; Kerdahi, Khalil

2014-03-01

Cyclospora cayetanensis is an apicocomplexan parasite that infects the gastrointestinal tract and causes acute diarrheal disease in humans. In recent years, this human-pathogenic parasite has led to several foodborne outbreaks in the United States and Canada, mostly associated with imported produce. Understanding the biology and epidemiology of C. cayetanensis is difficult because little is known about its origin, possible zoonotic reservoirs, and genetic relationships with other coccidian parasites. Recently, we developed a 70kDa heat shock protein (HSP70) gene based nested PCR protocol for detection of C. cayetanensis parasite and sequenced the PCR products of 16 human isolates from Nepal, Mexico, and Peru. In this study, we have characterized the regions of 18S ribosomal RNA (rRNA) gene of 17 human C. cayetanensis isolates for molecular detection, and also to ascertain the genetic diversity of this parasite. The 18S rRNA primer sets were further tested by PCR amplification followed by nucleotide sequencing of the PCR amplified products of previously characterized C. cayetanensis isolates from three endemic regions at HSP70 locus. Although no genetic polymorphism was observed at the regions of HSP70 locus characterized in our previous study, the data analysis of this study revealed a minor genetic diversity at the 18S rRNA locus among the C. cayetanensis isolates. The 18S rRNA gene-based nested PCR protocol provides a useful genetic marker for the detection of C. cayetanensis parasite and confirms it as a genetically distinct species in genus Cyclospora. The results also supported lack of geographic segregation and existence of genetically homogeneous population for the C. cayetanensis parasites both at the HSP70 as well as at the18S rRNA loci. Published by Elsevier B.V.

Crystallization and preliminary X-ray analysis of Na-SAA-2 from the human hookworm parasite Necator americanus

International Nuclear Information System (INIS)

Asojo, Oluwatoyin A.; Goud, Gaddam N.; Zhan, Bin; Ordonez, Katherine; Sedlacek, Meghan; Homma, Kohei; Deumic, Vehid; Gupta, Richi; Brelsford, Jill; Price, Merelyn K.; Ngamelue, Michelle N.; Hotez, Peter J.

2010-01-01

The purification, crystallization and preliminary X-ray diffraction analysis of a surface-associated antigen from the major human hookworm N. americanus is presented. Human hookworms are among the most pathogenic soil-transmitted helminths. These parasitic nematodes have co-evolved with the host and are able to maintain a high worm burden for decades without killing the human host. However, it is possible to develop vaccines against laboratory-challenge hookworm infections using either irradiated third-state infective larvae (L3) or enzymes from the adult parasites. In an effort to control hookworm infection globally, the Human Hookworm Vaccine Initiative, a product-development partnership with the Sabin Vaccine Institute to develop new control tools including vaccines, has identified a battery of protein antigens, including surface-associated antigens (SAAs) from L3. SAA proteins are characterized by a 13 kDa conserved domain of unknown function. SAA proteins are found on the surface of infective L3 stages (and some adult stages) of different nematode parasites, suggesting that they may play important roles in these organisms. The atomic structures and function of SAA proteins remain undetermined and in an effort to remedy this situation recombinant Na-SAA-2 from the most prevalent human hookworm parasite Necator americanus has been expressed, purified and crystallized. Useful X-ray data have been collected to 2.3 Å resolution from a crystal that belonged to the monoclinic space group C2 with unit-cell parameters a = 73.88, b = 35.58, c = 42.75 Å, β = 116.1°

African origin of the malaria parasite Plasmodium vivax.

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Liu, Weimin; Li, Yingying; Shaw, Katharina S; Learn, Gerald H; Plenderleith, Lindsey J; Malenke, Jordan A; Sundararaman, Sesh A; Ramirez, Miguel A; Crystal, Patricia A; Smith, Andrew G; Bibollet-Ruche, Frederic; Ayouba, Ahidjo; Locatelli, Sabrina; Esteban, Amandine; Mouacha, Fatima; Guichet, Emilande; Butel, Christelle; Ahuka-Mundeke, Steve; Inogwabini, Bila-Isia; Ndjango, Jean-Bosco N; Speede, Sheri; Sanz, Crickette M; Morgan, David B; Gonder, Mary K; Kranzusch, Philip J; Walsh, Peter D; Georgiev, Alexander V; Muller, Martin N; Piel, Alex K; Stewart, Fiona A; Wilson, Michael L; Pusey, Anne E; Cui, Liwang; Wang, Zenglei; Färnert, Anna; Sutherland, Colin J; Nolder, Debbie; Hart, John A; Hart, Terese B; Bertolani, Paco; Gillis, Amethyst; LeBreton, Matthew; Tafon, Babila; Kiyang, John; Djoko, Cyrille F; Schneider, Bradley S; Wolfe, Nathan D; Mpoudi-Ngole, Eitel; Delaporte, Eric; Carter, Richard; Culleton, Richard L; Shaw, George M; Rayner, Julian C; Peeters, Martine; Hahn, Beatrice H; Sharp, Paul M

2014-01-01

Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.

African origin of the malaria parasite Plasmodium vivax

Science.gov (United States)

Liu, Weimin; Li, Yingying; Shaw, Katharina S.; Learn, Gerald H.; Plenderleith, Lindsey J.; Malenke, Jordan A.; Sundararaman, Sesh A.; Ramirez, Miguel A.; Crystal, Patricia A.; Smith, Andrew G.; Bibollet-Ruche, Frederic; Ayouba, Ahidjo; Locatelli, Sabrina; Esteban, Amandine; Mouacha, Fatima; Guichet, Emilande; Butel, Christelle; Ahuka-Mundeke, Steve; Inogwabini, Bila-Isia; Ndjango, Jean-Bosco N.; Speede, Sheri; Sanz, Crickette M.; Morgan, David B.; Gonder, Mary K.; Kranzusch, Philip J.; Walsh, Peter D.; Georgiev, Alexander V.; Muller, Martin N.; Piel, Alex K.; Stewart, Fiona A.; Wilson, Michael L.; Pusey, Anne E.; Cui, Liwang; Wang, Zenglei; Färnert, Anna; Sutherland, Colin J.; Nolder, Debbie; Hart, John A.; Hart, Terese B.; Bertolani, Paco; Gillis, Amethyst; LeBreton, Matthew; Tafon, Babila; Kiyang, John; Djoko, Cyrille F.; Schneider, Bradley S.; Wolfe, Nathan D.; Mpoudi-Ngole, Eitel; Delaporte, Eric; Carter, Richard; Culleton, Richard L.; Shaw, George M.; Rayner, Julian C.; Peeters, Martine; Hahn, Beatrice H.; Sharp, Paul M.

2014-01-01

Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa. PMID:24557500

Role of parasites in cancer.

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Mandong, B M; Ngbea, J A; Raymond, Vhriterhire

2013-01-01

In areas of parasitic endemicity, the occurrence of cancer that is not frequent may be linked with parasitic infection. Epidemiological correlates between some parasitic infections and cancer is strong, suggesting a strong aetiological association. The common parasites associated with human cancers are schistosomiasis, malaria, liver flukes (Clonorchis sinenses, Opistorchis viverrini). To review the pathology, literature and methods of diagnosis. Literature review from peer reviewed Journals cited in PubMed and local journals. Parasites may serve as promoters of cancer in endemic areas of infection.

Intestinal Parasitic Infections in Human Immunodeficiency Virus-Infected and Noninfected Persons in a High Human Immunodeficiency Virus Prevalence Region of Cameroon.

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Nkenfou, Céline Nguefeu; Tchameni, Sandrine Mboula; Nkenfou, Carine Nguefeu; Djataou, Patrice; Simo, Ulrich Florian; Nkoum, Alexandre Benjamin; Estrin, William

2017-09-01

The problem of intestinal parasitic infection in human immunodeficiency virus (HIV)-infected people requires careful consideration in the developing world where poor nutrition is associated with poor hygiene and several coinfecting diseases. Studies have addressed this issue in Cameroon, especially in the low HIV prevalence area. The current study was conducted to determine the prevalence of intestinal parasitosis in people living with HIV (PLHIV) in Adamaoua and to identify associated risk factors. Stool and blood specimens from study participants were screened for intestinal parasites and anti-HIV antibodies, respectively. Of 235 participants, 68 (28.9%) were HIV positive, 38 of them on antiretroviral treatment (ART). The overall prevalence of intestinal parasites was 32.3%. Of 68 PLHIV, 32.3% (22/68) were infected with intestinal parasites, compared with 32.3% (54/167) of the HIV-negative patients. Univariate analysis showed no difference between the prevalence of intestinal parasites among PLHIV and HIV-negative patients ( P = 0.69). ART was not associated with the prevalence of intestinal parasites. Multivariate analysis showed that the quality of water and the personal hygiene were the major risk factors associated to intestinal parasitosis. The level of education was associated with HIV serostatus: the higher the level of education, the lower the risk of being infected with HIV ( P = 0.00). PLHIV and the general population should be screened routinely for intestinal parasites and treated if infected.

Environmental risk and toxicology of human and veterinary waste pharmaceutical exposure to wild aquatic host-parasite relationships.

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Morley, Neil J

2009-03-01

Pollution of the aquatic environment by human and veterinary waste pharmaceuticals is an increasing area of concern but little is known about their ecotoxicological effects on wildlife. In particular the interactions between pharmaceuticals and natural stressors of aquatic communities remains to be elucidated. A common natural stressor of freshwater and marine organisms are protozoan and metazoan parasites, which can have significant effects on host physiology and population structure, especially under the influence of many traditional kinds of toxic pollutants. However, little is known about the effects of waste pharmaceuticals to host-parasite dynamics. In order to assess the risk waste pharmaceuticals pose to aquatic wildlife it has been suggested the use of toxicological data derived from mammals during the product development of pharmaceuticals may be useful for predicting toxic effects. An additional similar source of information is the extensive clinical studies undertaken with numerous classes of drugs against parasites of human and veterinary importance. These studies may form the basis of preliminary risk assessments to aquatic populations and their interactions with parasitic diseases in pharmaceutical-exposed habitats. The present article reviews the effects of the most common classes of pharmaceutical medicines to host-parasite relationships and assesses the risk they may pose to wild aquatic organisms. In addition the effects of pharmaceutical mixtures, the importance of sewage treatment, and the risk of developing resistant strains of parasites are also assessed. Copyright © 2008 Elsevier B.V. All rights reserved.

Parasites, Plants, and People.

Science.gov (United States)

Johnson, Marion; Moore, Tony

2016-06-01

Anthelminthic resistance is acknowledged worldwide and is a major problem in Aotearoa New Zealand, thus alternative parasite management strategies are imperative. One Health is an initiative linking animal, human, and environmental health. Parasites, plants, and people illustrate the possibilities of providing diverse diets for stock thereby lowering parasite burdens, improving the cultural wellbeing of a local community, and protecting the environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Vulval Elephantiasis: A Case Report

OpenAIRE

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 requisi...

The origin of malarial parasites in orangutans.

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M Andreína Pacheco

Full Text Available BACKGROUND: Recent findings of Plasmodium in African apes have changed our perspectives on the evolution of malarial parasites in hominids. However, phylogenetic analyses of primate malarias are still missing information from Southeast Asian apes. In this study, we report molecular data for a malaria parasite lineage found in orangutans. METHODOLOGY/PRINCIPAL FINDINGS: We screened twenty-four blood samples from Pongo pygmaeus (Kalimantan, Indonesia for Plasmodium parasites by PCR. For all the malaria positive orangutan samples, parasite mitochondrial genomes (mtDNA and two antigens: merozoite surface protein 1 42 kDa (MSP-1(42 and circumsporozoite protein gene (CSP were amplified, cloned, and sequenced. Fifteen orangutans tested positive and yielded 5 distinct mitochondrial haplotypes not previously found. The haplotypes detected exhibited low genetic divergence among them, indicating that they belong to one species. We report phylogenetic analyses using mitochondrial genomes, MSP-1(42 and CSP. We found that the orangutan malaria parasite lineage was part of a monophyletic group that includes all the known non-human primate malaria parasites found in Southeast Asia; specifically, it shares a recent common ancestor with P. inui (a macaque parasite and P. hylobati (a gibbon parasite suggesting that this lineage originated as a result of a host switch. The genetic diversity of MSP-1(42 in orangutans seems to be under negative selection. This result is similar to previous findings in non-human primate malarias closely related to P. vivax. As has been previously observed in the other Plasmodium species found in non-human primates, the CSP shows high polymorphism in the number of repeats. However, it has clearly distinctive motifs from those previously found in other malarial parasites. CONCLUSION: The evidence available from Asian apes indicates that these parasites originated independently from those found in Africa, likely as the result of host

Parasitic Nematode Interactions with Mammals and Plants

NARCIS (Netherlands)

Jasmer, D.P.; Goverse, A.; Smant, G.

2003-01-01

Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent

Parasitic Zoonoses in Humans and Their Dogs from a Rural Community of Tropical Mexico

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Antonio Ortega-Pacheco

2015-01-01

Full Text Available A cross-sectional study was made on 89 inhabitants and their dogs from a rural community of Yucatan, Mexico, to determine the serological prevalence of some zoonotic parasitic agents. Samples were taken to monitor the presence and intensity of infection with gastrointestinal parasites in dogs. In humans, the serological prevalence of T. canis, T. gondii, and T. spiralis was 29.2%, 91.0%, and 6.7%, respectively. No associations were found between positive cases and studied variables. From the total of blood samples taken from dogs, 87 (97.6% were seropositive to T. gondii; only 52 viable fecal samples were collected from dogs of which 46.2% had the presence of gastrointestinal parasites with low to moderate intensity; from those, 12% had the presence of T. canis. This study demonstrates the presence of the studied zoonotic agents in the area particularly T. gondii which suggest a common source of infection in dogs and humans and a high number of oocyts present in the environment. Preventive measures must be designed towards good prophylactic practices in domestic and backyard animals (T. canis and T. spiralis. Contaminated sources with T. gondii (food and water should be further investigated in order to design effective control measures.

ORMS IN SURPRISING PLACES: CLINICAL AND MORPHOLOGICAL FEATURES

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Myroshnychenko MS

2013-06-01

Full Text Available Helminthes are the most common human diseases, which are characterized by involvement in the pathological process of all organs and systems. In this article, the authors discuss a few cases of typical and atypical localizations for parasitic worms such as filarial and pinworms which were recovered from surprising places in the bodies of patients in Kharkiv region. This article will allow the doctors of practical health care to pay special attention to the timely prevention and diagnostics of this pathology.

Unique parasite aDNA in moa coprolites from New Zealand suggests mass parasite extinctions followed human-induced megafauna extinctions

Science.gov (United States)

Lafferty, Kevin D.; Hopkins, Skylar R.

2018-01-01

Having split early from Gondwana, Zealandia (now modern New Zealand) escaped discovery until the late 13th century, and therefore remains an important glimpse into a human-free world. Without humans or other land mammals, diverse and peculiar birds evolved in isolation, including several flightless moa species, the giant pouakai eagle (Harpagornis moorei), the kiwi (Apteryx mantelli), and the kakapo parrot (Strigops habroptila). This unique community has fascinated paleoecologists, who have spent almost two centuries devising new ways to glean information from ancient bird remains. In PNAS, Boast et al. (1) apply one recent technological advance, ancient DNA (aDNA) metabarcoding, to confirm previous discoveries and report new details about moa and kakapo diets, parasites, and niches. Their efforts confirm Zealandia was a lot different before humans arrived.

Functional expression of parasite drug targets and their human orthologs in yeast.

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Elizabeth Bilsland

2011-10-01

Full Text Available The exacting nutritional requirements and complicated life cycles of parasites mean that they are not always amenable to high-throughput drug screening using automated procedures. Therefore, we have engineered the yeast Saccharomyces cerevisiae to act as a surrogate for expressing anti-parasitic targets from a range of biomedically important pathogens, to facilitate the rapid identification of new therapeutic agents.Using pyrimethamine/dihydrofolate reductase (DHFR as a model parasite drug/drug target system, we explore the potential of engineered yeast strains (expressing DHFR enzymes from Plasmodium falciparum, P. vivax, Homo sapiens, Schistosoma mansoni, Leishmania major, Trypanosoma brucei and T. cruzi to exhibit appropriate differential sensitivity to pyrimethamine. Here, we demonstrate that yeast strains (lacking the major drug efflux pump, Pdr5p expressing yeast ((ScDFR1, human ((HsDHFR, Schistosoma ((SmDHFR, and Trypanosoma ((TbDHFR and (TcDHFR DHFRs are insensitive to pyrimethamine treatment, whereas yeast strains producing Plasmodium ((PfDHFR and (PvDHFR DHFRs are hypersensitive. Reassuringly, yeast strains expressing field-verified, drug-resistant mutants of P. falciparum DHFR ((Pfdhfr(51I,59R,108N are completely insensitive to pyrimethamine, further validating our approach to drug screening. We further show the versatility of the approach by replacing yeast essential genes with other potential drug targets, namely phosphoglycerate kinases (PGKs and N-myristoyl transferases (NMTs.We have generated a number of yeast strains that can be successfully harnessed for the rapid and selective identification of urgently needed anti-parasitic agents.

Human behavior and opportunities for parasite transmission in communities surrounding long-tailed macaque populations in Bali, Indonesia.

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Lane-DeGraaf, Kelly E; Putra, I G A Arta; Wandia, I Nengah; Rompis, Aida; Hollocher, Hope; Fuentes, Agustin

2014-02-01

Spatial overlap and shared resources between humans and wildlife can exacerbate parasite transmission dynamics. In Bali, Indonesia, an agricultural-religious temple system provides sanctuaries for long-tailed macaques (Macaca fascicularis), concentrating them in areas in close proximity to humans. In this study, we interviewed individuals in communities surrounding 13 macaque populations about their willingness to participate in behaviors that would put them at risk of exposure to gastrointestinal parasites to understand if age, education level, or occupation are significant determinants of exposure behaviors. These exposure risk behaviors and attitudes include fear of macaques, direct contact with macaques, owning pet macaques, hunting and eating macaques, and overlapping water uses. We find that willingness to participate in exposure risk behaviors are correlated with an individual's occupation, age, and/or education level. We also found that because the actual risk of infection varies across populations, activities such as direct macaque contact and pet ownership, could be putting individuals at real risk in certain contexts. Thus, we show that human demographics and social structure can influence willingness to participate in behaviors putting them at increased risk for exposure to parasites. © 2013 Wiley Periodicals, Inc.

Helminth parasites of cats from the Vientiane Province, Laos, as indicators of the occurrence of causative agents of human parasitoses

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Scholz T.

2003-12-01

Full Text Available A total of 55 domestic cats (Felis calus f. domestico and one wild (Bengal cat (Prionailurus bengalensis from the Vientiane Province, central Laos, were examined for helminth parasites with emphasis given to potential human parasites. The following species were found (parasites infective to man marked with an asterisk: Opisthorchis viverrini*, Haplorchis pumilio*,H. laichui*,H. yokogawai*, Stellantchasmus falcatus* (Digenea; Spirometra sp.*, Dipylidium caninum*, Taenia taeniaeformis (Cestoda; Capillariidae gen. sp., Toxocara canis*, T. cati*, Ancylostoma ceylanicum*, A. tubaeforme, Gnathostoma spinigerum*, Physaloptera preputials (Nematoda; and Oncicola sp. (Acanthocephala. This study demonstrated that examination of cats may provide useful data on the occurrence of helminths which are potential causative agents of human diseases.

Primary structure of and immunoglobulin E response to the repeat subunit of gp15/400 from human lymphatic filarial parasites

NARCIS (Netherlands)

Paxton, W. A.; Yazdanbakhsh, M.; Kurniawan, A.; Partono, F.; Maizels, R. M.; Selkirk, M. E.

1993-01-01

We have isolated and sequenced clones encoding the repeated subunit of the surface-associated glycoprotein gp15/400 from the two nematode species predominantly responsible for lymphatic filariasis in humans: Brugia malayi and Wuchereria bancrofti. The amino acid sequence of the 15-kDa subunit,

Cockroaches as carriers of human intestinal parasites in two localities in Ethiopia.

Science.gov (United States)

Kinfu, Addisu; Erko, Berhanu

2008-11-01

A study was undertaken to assess the role of cockroaches as potential carriers of human intestinal parasites in Addis Ababa and Ziway, Ethiopia. A total of 6480 cockroaches were trapped from the two localities from October 2006 to March 2007. All the cockroaches trapped in Addis Ababa (n=2240) and almost 50% (2100/4240) of those trapped in Ziway were identified as Blattella germanica. The rest of the cockroaches trapped in Ziway were identified as Periplaneta brunnea (24.52%), Pycnoscelus surinamensis (16.03%) and Supella longipalpa (9.90%). Microscopic examination of the external body washes of pooled cockroaches and individual gut contents revealed that cockroaches are carriers of Entamoeba coli and Entamoeba histolytica/dispar cysts as well as Enterobius vermicularis, Trichuris trichiura, Taenia spp. and Ascaris lumbricoides ova. Besides their role as a nuisance, the present study further confirms that cockroaches serve as carriers of human intestinal parasites. The possible association of cockroaches with allergic conditions such as asthma is also discussed. Hence, appropriate control measures should be taken particularly to make hotels and residential areas free of cockroaches as they represent a health risk.

The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

Science.gov (United States)

Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo

2014-01-01

Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission. PMID:25185005

Repurposing of approved drugs from the human pharmacopoeia to target Wolbachia endosymbionts of onchocerciasis and lymphatic filariasis

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Kelly L. Johnston

2014-12-01

Full Text Available Lymphatic filariasis and onchocerciasis are debilitating diseases caused by parasitic filarial nematodes infecting around 150 million people throughout the tropics with more than 1.5 billion at risk. As with other neglected tropical diseases, classical drug-discovery and development is lacking and a 50 year programme of macrofilaricidal discovery failed to deliver a drug which can be used as a public health tool. Recently, antibiotic targeting of filarial Wolbachia, an essential bacterial symbiont, has provided a novel drug treatment for filariasis with macrofilaricidal activity, although the current gold-standard, doxycycline, is unsuitable for use in mass drug administration (MDA. The anti-Wolbachia (A·WOL Consortium aims to identify novel anti-Wolbachia drugs, compounds or combinations that are suitable for use in MDA. Development of a Wolbachia cell-based assay has enabled the screening of the approved human drug-pharmacopoeia (∼2600 drugs for a potential repurposing. This screening strategy has revealed that approved drugs from various classes show significant bacterial load reduction equal to or superior to the gold-standard doxycycline, with 69 orally available hits from different drug categories being identified. Based on our defined hit criteria, 15 compounds were then selectively screened in a Litomosoides sigmodontis mouse model, 4 of which were active. These came from the tetracycline, fluoroquinolone and rifamycin classes. This strategy of repurposing approved drugs is a promising development in the goal of finding a novel treatment against filariasis and could also be a strategy applicable for other neglected tropical diseases.

Mitosis in the Human Malaria Parasite Plasmodium falciparum ▿

OpenAIRE

Gerald, Noel; Mahajan, Babita; Kumar, Sanjai

2011-01-01

Malaria is caused by intraerythrocytic protozoan parasites belonging to Plasmodium spp. (phylum Apicomplexa) that produce significant morbidity and mortality, mostly in developing countries. Plasmodium parasites have a complex life cycle that includes multiple stages in anopheline mosquito vectors and vertebrate hosts. During the life cycle, the parasites undergo several cycles of extreme population growth within a brief span, and this is critical for their continued transmission and a contri...

Transcriptionally Driven DNA Replication Program of the Human Parasite Leishmania major.

Science.gov (United States)

Lombraña, Rodrigo; Álvarez, Alba; Fernández-Justel, José Miguel; Almeida, Ricardo; Poza-Carrión, César; Gomes, Fábia; Calzada, Arturo; Requena, José María; Gómez, María

2016-08-09

Faithful inheritance of eukaryotic genomes requires the orchestrated activation of multiple DNA replication origins (ORIs). Although origin firing is mechanistically conserved, how origins are specified and selected for activation varies across different model systems. Here, we provide a complete analysis of the nucleosomal landscape and replication program of the human parasite Leishmania major, building on a better evolutionary understanding of replication organization in Eukarya. We found that active transcription is a driving force for the nucleosomal organization of the L. major genome and that both the spatial and the temporal program of DNA replication can be explained as associated to RNA polymerase kinetics. This simple scenario likely provides flexibility and robustness to deal with the environmental changes that impose alterations in the genetic programs during parasitic life cycle stages. Our findings also suggest that coupling replication initiation to transcription elongation could be an ancient solution used by eukaryotic cells for origin maintenance. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Transcriptionally Driven DNA Replication Program of the Human Parasite Leishmania major

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Rodrigo Lombraña

2016-08-01

Full Text Available Faithful inheritance of eukaryotic genomes requires the orchestrated activation of multiple DNA replication origins (ORIs. Although origin firing is mechanistically conserved, how origins are specified and selected for activation varies across different model systems. Here, we provide a complete analysis of the nucleosomal landscape and replication program of the human parasite Leishmania major, building on a better evolutionary understanding of replication organization in Eukarya. We found that active transcription is a driving force for the nucleosomal organization of the L. major genome and that both the spatial and the temporal program of DNA replication can be explained as associated to RNA polymerase kinetics. This simple scenario likely provides flexibility and robustness to deal with the environmental changes that impose alterations in the genetic programs during parasitic life cycle stages. Our findings also suggest that coupling replication initiation to transcription elongation could be an ancient solution used by eukaryotic cells for origin maintenance.

The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

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Ryan C Smith

2014-08-01

Full Text Available Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.

Natural infection of Plasmodium brasilianum in humans: Man and monkey share quartan malaria parasites in the Venezuelan Amazon

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Albert Lalremruata

2015-09-01

Interpretation: This study reports, for the first time, naturally acquired infections in humans with parasites termed as P. brasilianum. We conclude that quartan malaria parasites are easily exchanged between humans and monkeys in Latin America. We hypothesize a lack of host specificity in mammalian hosts and consider quartan malaria to be a true anthropozoonosis. Since the name P. brasilianum suggests a malaria species distinct from P. malariae, we propose that P. brasilianum should have a nomenclatorial revision in case further research confirms our findings. The expansive reservoir of mammalian hosts discriminates quartan malaria from other Plasmodium spp. and requires particular research efforts.

Chimpanzee malaria parasites related to Plasmodium ovale in Africa.

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Linda Duval

Full Text Available Since the 1970's, the diversity of Plasmodium parasites in African great apes has been neglected. Surprisingly, P. reichenowi, a chimpanzee parasite, is the only such parasite to have been molecularly characterized. This parasite is closely phylogenetically related to P. falciparum, the principal cause of the greatest malaria burden in humans. Studies of malaria parasites from anthropoid primates may provide relevant phylogenetic information, improving our understanding of the origin and evolutionary history of human malaria species. In this study, we screened 130 DNA samples from chimpanzees (Pan troglodytes and gorillas (Gorilla gorilla from Cameroon for Plasmodium infection, using cytochrome b molecular tools. Two chimpanzees from the subspecies Pan t. troglodytes presented single infections with Plasmodium strains molecularly related to the human malaria parasite P. ovale. These chimpanzee parasites and 13 human strains of P. ovale originated from a various sites in Africa and Asia were characterized using cytochrome b and cytochrome c oxidase 1 mitochondrial partial genes and nuclear ldh partial gene. Consistent with previous findings, two genetically distinct types of P. ovale, classical and variant, were observed in the human population from a variety of geographical locations. One chimpanzee Plasmodium strain was genetically identical, on all three markers tested, to variant P. ovale type. The other chimpanzee Plasmodium strain was different from P. ovale strains isolated from humans. This study provides the first evidence of possibility of natural cross-species exchange of P. ovale between humans and chimpanzees of the subspecies Pan t. troglodytes.

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.

Science.gov (United States)

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

Exoemission of Ethiopian soils and the endemicity of non-filarial elephantiasis

Energy Technology Data Exchange (ETDEWEB)

Davies, J.E. (Birmingham Univ. (UK). Dept. of Anatomy); Townsend, P.D. (Sussex Univ., Brighton (UK))

1983-01-01

Non-filarial elephantiasis is an endemic disease in the bare-footed population of Ethiopia. The distribution of this condition is linked with that of local red clay soil. Recently, thermoluminescence has been successfully used to distinguish between endemic and non-endemic soils. Instrinsic lattice defects, frozen in during cooling of volcanic material, are considered to be responsible for characteristic thermoluminescence signals. However, the biological reactivity of the absorbed soil particles will depend upon their surface properties. Exoemission has therefore been studied in samples from both endemic (5 samples) and non-endemic (4 samples) areas. All samples from endemic areas, on first heating, demonstrate an emission peak at 75/sup 0/C. Post-irradiation storage of samples in a moist atmosphere tends to decrease emissivity while wetting irreversibly reduces the response to irradiation. In an hydrated biological environment, this surface reactivity may be linked to the pathogenicity of the soil particles.

Exoemission of Ethiopian soils and the endemicity of non-filarial elephantiasis

International Nuclear Information System (INIS)

Davies, J.E.

1983-01-01

Non-filarial elephantiasis is an endemic disease in the bare-footed population of Ethiopia. The distribution of this condition is linked with that of local red clay soil. Recently, thermoluminescence has been successfully used to distinguish between endemic and non-endemic soils. Instrinsic lattice defects, frozen in during cooling of volcanic material, are considered to be responsible for characteristic thermoluminescence signals. However, the biological reactivity of the absorbed soil particles will depend upon their surface properties. Exoemission has therefore been studied in samples from both endemic (5 samples) and non-endemic (4 samples) areas. All samples from endemic areas, on first heating, demonstrate an emission peak at 75 0 C. Post-irradiation storage of samples in a moist atmosphere tends to decrease emissivity while wetting irreversibly reduces the response to irradiation. In an hydrated biological environement, this surface reactivity may be linked to the pathogenicity of the soil particles. (author)

Identification and characterization of a selenium-dependent glutathione peroxidase in Setaria cervi

International Nuclear Information System (INIS)

Singh, Anchal; Rathaur, Sushma

2005-01-01

Setaria cervi a bovine filarial parasite secretes selenium glutathione peroxidase during in vitro cultivation. A significant amount of enzyme activity was detected in the somatic extract of different developmental stages of the parasite. Among different stages, microfilariae showed a higher level of selenium glutathione peroxidase activity followed by males then females. However, when the activity was compared in excretory secretory products of these stages males showed higher activity than microfilariae and female worms. The enzyme was purified from female somatic extract using a combination of glutathione agarose and gel filtration chromatography, which migrated as a single band of molecular mass ∼20 kDa. Selenium content of purified enzyme was estimated by atomic absorption spectroscopy and found to be 3.5 ng selenium/μg of protein. Further, inhibition of enzyme activity by potassium cyanide suggested the presence of selenium at the active site of enzyme. This is the first report of identification of selenium glutathione peroxidase from any filarial parasite

Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode.

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Georgios Koutsovoulos

2014-06-01

Full Text Available 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.

Epidemiological assessment of neglected diseases in children: lymphatic filariasis and soil-transmitted helminthiasis.

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Aguiar-Santos, Ana M; Medeiros, Zulma; Bonfim, Cristine; Rocha, Abraham C; Brandão, Eduardo; Miranda, Tereza; Oliveira, Paula; Sarinho, Emanuel S C

2013-01-01

To report the prevalence of lymphatic filariasis and intestinal parasitic infections in school-aged children living in a filariasis endemic area and discuss about the therapeutic regimen adopted in Brazil for the large-scale treatment of filariasis. A cross-sectional study including 508 students aged 5-18 years old, enrolled in public schools within the city of Olinda, Pernambuco. The presence of intestinal parasites was analyzed using the Hoffman, Pons and Janer method on 3 stool samples. The diagnosis of filarial infection was performed using the rapid immunochromatographic technique (ICT) for the antigen, and the polycarbonate membrane filtration for the presence of microfilariae. Descriptive statistics of the data was performed using EpiInfo version 7. The prevalence of filariasis was 13.8% by ICT and 1.2% by microfilaraemia, while intestinal parasites were detected in 64.2% of cases. Concurrent diagnosis of filariasis and intestinal parasites was 9.4%, while 31.5% of students were parasite-free. Among individuals with intestinal parasites, 55% had one parasite and 45% had more than one parasite. Geohelminths occurred in 72.5% of the parasited individuals. In the group with filarial infection the prevalence of soil-transmitted helminthiasis was 54.5%. The simultaneous diagnosis of filariasis and intestinal parasites as well as the high frequency of geohelminths justify the need to reevaluate the treatment strategy used in the Brazilian filariasis large-scale treatment program. Copyright © 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

DNA typing of ancient parasite eggs from environmental samples identifies human and animal worm infections in Viking-age settlement.

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Søe, Martin Jensen; Nejsum, Peter; Fredensborg, Brian Lund; Kapel, Christian Moliin Outzen

2015-02-01

Ancient parasite eggs were recovered from environmental samples collected at a Viking-age settlement in Viborg, Denmark, dated 1018-1030 A.D. Morphological examination identified Ascaris sp., Trichuris sp., and Fasciola sp. eggs, but size and shape did not allow species identification. By carefully selecting genetic markers, PCR amplification and sequencing of ancient DNA (aDNA) isolates resulted in identification of: the human whipworm, Trichuris trichiura , using SSUrRNA sequence homology; Ascaris sp. with 100% homology to cox1 haplotype 07; and Fasciola hepatica using ITS1 sequence homology. The identification of T. trichiura eggs indicates that human fecal material is present and, hence, that the Ascaris sp. haplotype 07 was most likely a human variant in Viking-age Denmark. The location of the F. hepatica finding suggests that sheep or cattle are the most likely hosts. Further, we sequenced the Ascaris sp. 18S rRNA gene in recent isolates from humans and pigs of global distribution and show that this is not a suited marker for species-specific identification. Finally, we discuss ancient parasitism in Denmark and the implementation of aDNA analysis methods in paleoparasitological studies. We argue that when employing species-specific identification, soil samples offer excellent opportunities for studies of human parasite infections and of human and animal interactions of the past.

Study of the gastrointestinal parasitic fauna of captive non-human primates (Macaca fascicularis).

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Zanzani, Sergio Aurelio; Gazzonis, Alessia Libera; Epis, Sara; Manfredi, Maria Teresa

2016-01-01

The aim of this study was to examine helminths and protozoans in cynomolgus macaques (Macaca fascicularis) imported from registered breeding facilities in China and their relation to health risks for non-human primate handlers in biomedical research centers and in breeding facilities. Fresh fecal samples were collected from a total of 443 M. fascicularis and analyzed by copromicroscopical analysis, immunoenzymatic, or molecular assays. As to helminths, whose eggs were shed in 2.03% of the samples, Trichuris and Oesophagostomum were the only two taxa found, with low prevalence and low eggs per gram (EPG) values. Protozoans were more frequently detected (87.40%), with Entamoeba coli (85.19%) and Endolimax nana (79.26%) as the most prevalent species shed. Other parasites found by fecal smear examination were uninucleated-cyst-producing Entamoebas (78.52%), Iodamoeba bütschlii (42.96%), and Chilomastix mesnili (24.44%), while cysts of Balantidium coli (22.2%) were only observed by sedimentation. No coproantigens of Giardia duodenalis, Cryptosporidium spp., and Entamoeba histolytica complex were detected. Blastocystis sp. infection was noticed in 87.63% of macaques by PCR. These cynomolgus monkeys were infected with many subtypes (ST1, ST2, ST3, ST5, and ST7), where the predominant Blastocystis sp. subtypes were ST2 (77.5%), followed by ST1 (63.5%). Data collected confirmed the presence of potentially zoonotic parasites and a high parasite diversity, suggesting the need for appropriate and sensitive techniques to adequately control them and related health risks for handlers of non-human primates in biomedical research centers and in breeding facilities.

Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis.

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Frances Mercer

2016-08-01

Full Text Available Trichomonas vaginalis (Tv is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells.

Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis

Science.gov (United States)

Mercer, Frances; Diala, Fitz Gerald I.; Chen, Yi-Pei; Molgora, Brenda M.; Ng, Shek Hang; Johnson, Patricia J.

2016-01-01

Trichomonas vaginalis (Tv) is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells. PMID:27529696

The NIH-NIAID Filariasis Research Reagent Resource Center.

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Michelle L Michalski

2011-11-01

Full Text Available 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.

Filarial infections in domestic dogs in Lusaka, Zambia

DEFF Research Database (Denmark)

Siwila, Joyce; Mwase, Enala T.; Nejsum, Peter

2015-01-01

Filariae are common parasites of dogs in many parts of the world, but little is known about the status of these infections in sub-Saharan Africa. A study was carried out to determine the occurrence and species of filariae among 272 dogs in Lusaka, Zambia. Giemsa stained blood smear and Knott......'s concentration methods revealed microfilariae in 16 (5.9%) of the dogs. PCR confirmed that most of these dogs had Acanthocheilonema reconditum infection. Ten (4.0%) of the examined dogs were positive for Dirofilaria immitis circulating antigen (by DiroCHEK(®) test), but D. immitis microfilariae were...... not identified in any of the dogs and the status of this infection remains unclear. Further studies are needed to explore the occurrence of filariae in Zambian dogs and the zoonotic potential for humans....

Laboratory Diagnosis of Parasites from the Gastrointestinal Tract.

Science.gov (United States)

Garcia, Lynne S; Arrowood, Michael; Kokoskin, Evelyne; Paltridge, Graeme P; Pillai, Dylan R; Procop, Gary W; Ryan, Norbert; Shimizu, Robyn Y; Visvesvara, Govinda

2018-01-01

This Practical Guidance for Clinical Microbiology document on the laboratory diagnosis of parasites from the gastrointestinal tract provides practical information for the recovery and identification of relevant human parasites. The document is based on a comprehensive literature review and expert consensus on relevant diagnostic methods. However, it does not include didactic information on human parasite life cycles, organism morphology, clinical disease, pathogenesis, treatment, or epidemiology and prevention. As greater emphasis is placed on neglected tropical diseases, it becomes highly probable that patients with gastrointestinal parasitic infections will become more widely recognized in areas where parasites are endemic and not endemic. Generally, these methods are nonautomated and require extensive bench experience for accurate performance and interpretation. Copyright © 2017 American Society for Microbiology.

Clinical Correlates of Diarrhea and Gut Parasites among Human Immunodeficiency Virus Seropositive Patients

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Elvis Bisong

2017-09-01

Full Text Available Cluster differentiation 4 (CD4 count estimation, which is not readily available in most resource poor settings in Nigeria, is an important indexdetermining commencement of antiretroviral therapy (ART. It is imperative for physicians who come in contact with these patients in such settings to recognize other parameters to evaluate these patients. The clinical correlates of diarrhea and gut parasites among human immunodeficiency virus (HIV-seropositive patients attending our special treatment clinic were studied. Three hundred and forty consenting HIV-positive adult subjects were enrolled. Their stool and blood specimens were collected for a period of three months. Stool samples were analyzed for the presence of diarrhea and gut parasites. The patients were clinically evaluated by physical examination for the presence of pallor, dehydration, oral thrush, wasting lymphadenopathy, dermatitis, skin hyperpigmentation, and finger clubbing. Participants with diarrhea represented 14.1% of the population, while 21.5% harbored one or more parasites. In the subjects with diarrhea, 14.6% harbored gut parasites. The presence of diarrhea was associated with a low CD4 count. Clinically, oral thrush, wasting, and rashes were more reliable predictors of low CD4 count levels; whereas, the presence of pallor, dehydration, wasting, and rashes correlated with the presence of diarrhea. HIV patients presenting with pallor, dehydration, wasting, and rashes should be evaluated for the presence of diarrhea. The clinical variables associated with low CD4 count in this study may guide commencing antiretroviral therapy in resource poor settings.

The Ecology of Parasite-Host Interactions at Montezuma Well National Monument, Arizona - Appreciating the Importance of Parasites

Science.gov (United States)

O'Brien, Chris; van Riper, Charles

2009-01-01

Although parasites play important ecological roles through the direct interactions they have with their hosts, historically that fact has been underappreciated. Today, scientists have a growing appreciation of the scope of such impacts. Parasites have been reported to dominate food webs, alter predator-prey relationships, act as ecosystem engineers, and alter community structure. In spite of this growing awareness in the scientific community, parasites are still often neglected in the consideration of the management and conservation of resources and ecosystems. Given that at least half of the organisms on earth are probably parasitic, it should be evident that the ecological functions of parasites warrant greater attention. In this report, we explore different aspects of parasite-host relationships found at a desert spring pond within Montezuma Well National Monument, Arizona. In three separate but related chapters, we explore interactions between a novel amphipod host and two parasites. First, we identify how host behavior responds to this association and how this association affects interactions with both invertebrate non-host predators and a vertebrate host predator. Second, we look at the human dimension, investigating how human recreation can indirectly affect patterns of disease by altering patterns of vertebrate host space use. Finally - because parasites and diseases are of increasing importance in the management of wildlife species, especially those that are imperiled or of management concern - the third chapter argues that research would benefit from increased attention to the statistical analysis of wildlife disease studies. This report also explores issues of statistical parasitology, providing information that may better inform those designing research projects and analyzing data from studies of wildlife disease. In investigating the nature of parasite-host interactions, the role that relationships play in ecological communities, and how human

Northeast India Helminth Parasite Information Database (NEIHPID: Knowledge Base for Helminth Parasites.

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Devendra Kumar Biswal

Full Text Available Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species, or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php.

Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites.

Science.gov (United States)

Biswal, Devendra Kumar; Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

2016-01-01

Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php.

Northeast India Helminth Parasite Information Database (NEIHPID): Knowledge Base for Helminth Parasites

Science.gov (United States)

Debnath, Manish; Kharumnuid, Graciously; Thongnibah, Welfrank; Tandon, Veena

2016-01-01

Most metazoan parasites that invade vertebrate hosts belong to three phyla: Platyhelminthes, Nematoda and Acanthocephala. Many of the parasitic members of these phyla are collectively known as helminths and are causative agents of many debilitating, deforming and lethal diseases of humans and animals. The North-East India Helminth Parasite Information Database (NEIHPID) project aimed to document and characterise the spectrum of helminth parasites in the north-eastern region of India, providing host, geographical distribution, diagnostic characters and image data. The morphology-based taxonomic data are supplemented with information on DNA sequences of nuclear, ribosomal and mitochondrial gene marker regions that aid in parasite identification. In addition, the database contains raw next generation sequencing (NGS) data for 3 foodborne trematode parasites, with more to follow. The database will also provide study material for students interested in parasite biology. Users can search the database at various taxonomic levels (phylum, class, order, superfamily, family, genus, and species), or by host, habitat and geographical location. Specimen collection locations are noted as co-ordinates in a MySQL database and can be viewed on Google maps, using Google Maps JavaScript API v3. The NEIHPID database has been made freely available at http://nepiac.nehu.ac.in/index.php PMID:27285615

Update on pathology of ocular parasitic disease.

Science.gov (United States)

Das, Dipankar; Ramachandra, Varsha; Islam, Saidul; Bhattacharjee, Harsha; Biswas, Jyotirmay; Koul, Akanksha; Deka, Panna; Deka, Apurba

2016-11-01

Parasites are a group of eukaryotic organisms that may be free-living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa) or multicellular (helminths and arthropods). The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune-deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field.

Parasitic nematode interactions with mammals and plants.

Science.gov (United States)

Jasmer, Douglas P; Goverse, Aska; Smant, Geert

2003-01-01

Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent reinfection of host species. In addition, development of resistance to nematicides and anthelmintics by these parasites and reduced availability of some nematicides, for environmental protection, pose significant obstacles for current and future prospects of effective parasite control. Due to marked differences in host species, research on animal and plant parasitic nematodes often proceeds independently. Despite the differences between animals and plants, basic cellular properties are shared among these host organisms. Some common properties may be important for mechanisms [homologous or convergent (homoplastic)] by which nematodes successfully infect these diverse hosts or by which animal and plant hosts resist infections by these pathogens. Here we compare host/parasite interactions between plant parasitic nematodes (PPN) and animal parasitic nematodes, with an emphasis on mammalian hosts (MPN). Similarities and differences are considered in the context of progress on molecular dissection of these interactions. A comprehensive coverage is not possible in the space allotted. Instead, an illustrative approach is used to establish examples that, it is hoped, exemplify the value of the comparative approach.

Update on pathology of ocular parasitic disease

Directory of Open Access Journals (Sweden)

Dipankar Das

2016-01-01

Full Text Available Parasites are a group of eukaryotic organisms that may be free-living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa or multicellular (helminths and arthropods. The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune-deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field.

Species-specific escape of Plasmodium sporozoites from oocysts of avian, rodent, and human malarial parasites.

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Orfano, Alessandra S; Nacif-Pimenta, Rafael; Duarte, Ana P M; Villegas, Luis M; Rodrigues, Nilton B; Pinto, Luciana C; Campos, Keillen M M; Pinilla, Yudi T; Chaves, Bárbara; Barbosa Guerra, Maria G V; Monteiro, Wuelton M; Smith, Ryan C; Molina-Cruz, Alvaro; Lacerda, Marcus V G; Secundino, Nágila F C; Jacobs-Lorena, Marcelo; Barillas-Mury, Carolina; Pimenta, Paulo F P

2016-08-02

Malaria is transmitted when an infected mosquito delivers Plasmodium sporozoites into a vertebrate host. There are many species of Plasmodium and, in general, the infection is host-specific. For example, Plasmodium gallinaceum is an avian parasite, while Plasmodium berghei infects mice. These two parasites have been extensively used as experimental models of malaria transmission. Plasmodium falciparum and Plasmodium vivax are the most important agents of human malaria, a life-threatening disease of global importance. To complete their life cycle, Plasmodium parasites must traverse the mosquito midgut and form an oocyst that will divide continuously. Mature oocysts release thousands of sporozoites into the mosquito haemolymph that must reach the salivary gland to infect a new vertebrate host. The current understanding of the biology of oocyst formation and sporozoite release is mostly based on experimental infections with P. berghei, and the conclusions are generalized to other Plasmodium species that infect humans without further morphological analyses. Here, it is described the microanatomy of sporozoite escape from oocysts of four Plasmodium species: the two laboratory models, P. gallinaceum and P. berghei, and the two main species that cause malaria in humans, P. vivax and P. falciparum. It was found that sporozoites have species-specific mechanisms of escape from the oocyst. The two model species of Plasmodium had a common mechanism, in which the oocyst wall breaks down before sporozoites emerge. In contrast, P. vivax and P. falciparum sporozoites show a dynamic escape mechanism from the oocyst via polarized propulsion. This study demonstrated that Plasmodium species do not share a common mechanism of sporozoite escape, as previously thought, but show complex and species-specific mechanisms. In addition, the knowledge of this phenomenon in human Plasmodium can facilitate transmission-blocking studies and not those ones only based on the murine and avian models.

Mechanisms of cellular invasion by intracellular parasites.

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Walker, Dawn M; Oghumu, Steve; Gupta, Gaurav; McGwire, Bradford S; Drew, Mark E; Satoskar, Abhay R

2014-04-01

Numerous disease-causing parasites must invade host cells in order to prosper. Collectively, such pathogens are responsible for a staggering amount of human sickness and death throughout the world. Leishmaniasis, Chagas disease, toxoplasmosis, and malaria are neglected diseases and therefore are linked to socio-economical and geographical factors, affecting well-over half the world's population. Such obligate intracellular parasites have co-evolved with humans to establish a complexity of specific molecular parasite-host cell interactions, forming the basis of the parasite's cellular tropism. They make use of such interactions to invade host cells as a means to migrate through various tissues, to evade the host immune system, and to undergo intracellular replication. These cellular migration and invasion events are absolutely essential for the completion of the lifecycles of these parasites and lead to their for disease pathogenesis. This review is an overview of the molecular mechanisms of protozoan parasite invasion of host cells and discussion of therapeutic strategies, which could be developed by targeting these invasion pathways. Specifically, we focus on four species of protozoan parasites Leishmania, Trypanosoma cruzi, Plasmodium, and Toxoplasma, which are responsible for significant morbidity and mortality.

A New High-Throughput Approach to Genotype Ancient Human Gastrointestinal Parasites.

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Côté, Nathalie M L; Daligault, Julien; Pruvost, Mélanie; Bennett, E Andrew; Gorgé, Olivier; Guimaraes, Silvia; Capelli, Nicolas; Le Bailly, Matthieu; Geigl, Eva-Maria; Grange, Thierry

2016-01-01

Human gastrointestinal parasites are good indicators for hygienic conditions and health status of past and present individuals and communities. While microscopic analysis of eggs in sediments of archeological sites often allows their taxonomic identification, this method is rarely effective at the species level, and requires both the survival of intact eggs and their proper identification. Genotyping via PCR-based approaches has the potential to achieve a precise species-level taxonomic determination. However, so far it has mostly been applied to individual eggs isolated from archeological samples. To increase the throughput and taxonomic accuracy, as well as reduce costs of genotyping methods, we adapted a PCR-based approach coupled with next-generation sequencing to perform precise taxonomic identification of parasitic helminths directly from archeological sediments. Our study of twenty-five 100 to 7,200 year-old archeological samples proved this to be a powerful, reliable and efficient approach for species determination even in the absence of preserved eggs, either as a stand-alone method or as a complement to microscopic studies.

Zoonotic gastrointestinal parasite burden of local dogs in Zaria, Northern Nigeria: Implications for human health

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Christopher I. Ogbaje

2015-10-01

Full Text Available Background: Zoonotic gastrointestinal parasites of dogs are of the global problem particularly in the developing countries. Dogs are the most common pet animals worldwide and have been reported to be hosts of many intestinal parasites of zoonotic importance globally. In Nigeria, gastrointestinal helminthes of dogs is currently endemic in 20 of the 36 states. Aim: In general, dogs are the closest animals to humans and for that reason we decided to carry out a survey study to check the incidence of these parasites in dogs and to ascertain the level of environmental contamination in the study area. Materials and Methods: Fecal samples were collected from dog patients presented to small animal clinic of Veterinary Teaching Hospital of Faculty of Veterinary Medicine, Ahmadu Bello University Zaria, dog’s fecal droppings from the streets, and residential Quarters of the University and gastrointestinal tracts (GIT of dogs from dogs slaughtering house at Basawa Barrack, Zaria. Three methods were used in the analysis of the samples; simple flotation, sedimentation, and GIT processing methods within 48 h of collection. Results: Out of 224 samples analyzed 76(33.9% were positive of at least one of the parasites. Of the 101 samples from streets and residential quarters of ABU, Zaria, Isospora spp. 12(11.9% recorded the highest prevalence rate followed by Taenia spp. 6(5.9%, then Toxocara canis, Ancylostoma caninum, and Dipylidium caninum were 5.0%, 4.0%, and 1.0%, respectively. Isospora spp. (19.0% recorded the highest prevalence rate for the 100 samples collected from small animal clinic. Other parasites encountered were T. canis (8.0%, A. caninum (8.0% and Taenia spp. (5.0%. Parasites observed from the 23 gastrointestinal contents from “dog slaughtered houses” were T. canis (17.3%, Isospora spp.(13.1% and A. caninum (4.3. Conclusion: The study revealed that zoonotic gastrointestinal parasites of dogs are endemic in Zaria and the general public in the

Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

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Christensen Bruce M

2009-11-01

Full Text Available Abstract Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool and non-vector (Culex pipiens mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies.

Pathoecology of Chiribaya parasitism

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Martinson Elizabeth

2003-01-01

Full Text Available The excavations of Chiribaya culture sites in the Osmore drainage of southern Peru focused on the recovery of information about prehistoric disease, including parasitism. The archaeologists excavated human, dog, guinea pig, and llama mummies. These mummies were analyzed for internal and external parasites. The results of the analysis and reconstruction of prehistoric life from the excavations allows us to interpret the pathoecology of the Chiribaya culture.

[SWOT Analysis of the National Survey on Current Status of Major Human Parasitic Diseases in China].

Science.gov (United States)

ZHU, Hui-hui; ZHOU, Chang-hai; CHEN, Ying-dan; ZANG, Wei; XIAO, Ning; ZHOU, Xiao-nong

2015-10-01

The National Survey on Current Status of Major Human Parasitic Diseases in China has been carried out since 2014 under the organization of the National Health and Family Planning Commission of the People's Republic of China. The National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (NIPD, China CDC) provided technical support and was responsible for quality control in this survey. This study used SWOT method to analyze the strengths, weaknesses, opportunities and threats that were encountered by he NIPD, China CDC during the completion of the survey. Accordingly, working strategies were proposed to facilitate the future field work.

A mechanism for chronic filarial hydrocele with implications for its surgical repair.

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Joaquim Norões

Full Text Available BACKGROUND: Chronic hydrocele is the most common manifestation of bancroftian filariasis, an endemic disease in 80 countries. In a prospective study, we evaluated the occurrence of intrascrotal lymphangiectasia, gross appearance/consistency of the testis, and the efficacy of complete excision of hydrocele sac in patients living in a bancroftian filariasis endemic area who underwent hydrocelectomy at the Center for Teaching, Research and Tertiary Referral for Bancroftian Filariasis (NEPAF. METHODOLOGY/PRINCIPAL FINDINGS: A total of 968 patients with uni- or bilateral filarial hydrocele (Group-1 and a Comparison Group (CG of 218 patients from the same area who already had undergone hydrocele-sac-sparing hydrocelectomy elsewhere were enrolled at NEPAF. Twenty-eight patients from the Comparison Group with hydrocele recurrence were re-operated on at NEPAF and constitute Group-2. In Group-1 a total of 1,128 hydrocelectomies were performed (mean patient age of 30.3 yr and mean follow-up of 8.6 yr [range 5.3-12]. The hydrocele recurrence rates in Group-1 and in the Comparison Group (mean age of 31.5 yr were 0.3%, and 19.3%, respectively (p<0,001. There was no hydrocele recurrence in Group-2 (mean patient age of 25.1 yr and mean follow-up of 6 yr [range 5-6.9]. Per surgically leaking or leak-prone dilated lymphatic vessels were seen in the inner or outer surface of the hydrocele sac wall or in surrounding tissue, particularly in the retrotesticular area, in 30.9% and in 46.3% of patients in Group-1 and Group-2, respectively (p = 0.081. The testicles were abnormal in shape, volume, and consistency in 203/1,128 (18% and 10/28 (35.7% of patients from Group-1 and Group-2, respectively (p = 0,025. CONCLUSIONS/SIGNIFICANCE: Lymph fluid from ruptured dilated lymphatic vessels is an important component of chronic filarial hydrocele fluid that threatens the integrity of the testis in an adult population living in bancroftian filariasis endemic areas. To avoid

Repetitive elements in parasitic protozoa

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Clayton Christine

2010-05-01

Full Text Available Abstract A recent paper published in BMC Genomics suggests that retrotransposition may be active in the human gut parasite Entamoeba histolytica. This adds to our knowledge of the various types of repetitive elements in parasitic protists and the potential influence of such elements on pathogenicity. See research article http://www.biomedcentral.com/1471-2164/11/321

Genetic recombination between human and animal parasites creates novel strains of human pathogen.

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Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick

2015-03-01

Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

Genetic recombination between human and animal parasites creates novel strains of human pathogen.

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Wendy Gibson

2015-03-01

Full Text Available Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr responsible for sleeping sickness (Human African Trypanosomiasis, HAT in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

Parasites of importance for human health in Nigerian dogs: high prevalence and limited knowledge of pet owners.

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Ugbomoiko, Uade Samuel; Ariza, Liana; Heukelbach, Jorg

2008-12-09

Dogs are the most common pet animals worldwide. They may harbour a wide range of parasites with zoonotic potential, thus causing a health risk to humans. In Nigeria, epidemiological knowledge on these parasites is limited. In a community-based study, we examined 396 dogs in urban and rural areas of Ilorin (Kwara State, Central Nigeria) for ectoparasites and intestinal helminths. In addition, a questionnaire regarding knowledge and practices was applied to pet owners. Nine ectoparasite species belonging to four taxa and six intestinal helminth species were identified: fleas (Ctenocephalides canis, Pulex irritans, Tunga penetrans), mites (Demodex canis, Otodectes sp., Sarcoptes scabiei var. canis), ticks (Rhipicephalus sanguineus, Ixodes sp.), and lice (Trichodectes canis); and Toxocara canis, Ancylostoma sp., Trichuris vulpis, Dipylidium caninum, Taenidae and Strongyloides sp. Overall prevalence of ectoparasites was 60.4% and of intestinal helminths 68.4%. The occurrence of C. canis, R. sanguineus, T. canis, Ancylostoma sp. and T. vulpis was most common (prevalence 14.4% to 41.7%). Prevalence patterns in helminths were age-dependent, with T. canis showing a decreasing prevalence with age of host, and a reverse trend in other parasite species. Knowledge regarding zoonoses was very limited and the diseases not considered a major health problem. Treatment with antiparasitic drugs was more frequent in urban areas. Parasites of importance for human health were highly prevalent in Nigerian dogs. Interventions should include health education provided to dog owners and the establishment of a program focusing on zoonotic diseases.

Assessing drivers of the IgG4 antibody reactivity to recombinant antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa

DEFF Research Database (Denmark)

Hansen, Johanne Damgaard; Meyrowitsch, Dan W.; Rwegoshora, Rwehumbiza T.

2016-01-01

to the recombinant filarial antigen Bm14 in Wuchereria bancrofti endemic populations in East Africa. Sera collected during previous studies from 395 well characterized individuals with regard to age, sex, mf, CFA, household vector biting and household exposure to infective filarial larvae were tested for IgG4......A high proportion of the human population in lymphatic filariasis (LF) endemic areas is positive for filarial specific IgG4 antibodies, including many individuals without microfilariae (mf; circulating larvae in the human blood) or circulating filarial antigens (CFA; marker of adult worm infection...

Imaging of parasitic diseases

International Nuclear Information System (INIS)

Haddad, Maurice C.

2008-01-01

This book provides an overview of the imaging findings of parasitic diseases using modern imaging equipment. The chapters consist of short descriptions of causative pathogens, epidemiology, modes of transmission, pathology, clinical manifestations, laboratory tests, and imaging findings, with illustrative examples of parasitic diseases that can affect various systems of the human body. Tables summarizing key diagnostic features and clinical data pertinent to diagnosis are also included. This book is intended for radiologists worldwide. (orig.)

Imaging of parasitic diseases

Energy Technology Data Exchange (ETDEWEB)

Haddad, Maurice C. [American Univ. of Beirut Medical Center (Lebanon). Dept. of Diagnostic Radiology; Abd El Bagi, Mohamed E. [Riyadh Military Hospital (Saudi Arabia). Radiology and Imaging Dept. 920W; Tamraz, Jean C. (eds.) [CHU Hotel-Dieu de France, Beirut (Lebanon)

2008-07-01

This book provides an overview of the imaging findings of parasitic diseases using modern imaging equipment. The chapters consist of short descriptions of causative pathogens, epidemiology, modes of transmission, pathology, clinical manifestations, laboratory tests, and imaging findings, with illustrative examples of parasitic diseases that can affect various systems of the human body. Tables summarizing key diagnostic features and clinical data pertinent to diagnosis are also included. This book is intended for radiologists worldwide. (orig.)

Sex steroids, immune system, and parasitic infections: facts and hypotheses.

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Nava-Castro, Karen; Hernández-Bello, Romel; Muñiz-Hernández, Saé; Camacho-Arroyo, Ignacio; Morales-Montor, Jorge

2012-07-01

It has been widely reported that the incidence and the severity of natural parasitic infections are different between males and females of several species, including humans. This sexual dimorphism involves a distinct exposure of males and females to various parasite infective stages, differential effects of sex steroids on immune cells, and direct effects of these steroids on parasites, among others. Typically, for a large number of parasitic diseases, the prevalence and intensity is higher in males than females; however, in several parasitic infections, males are more resistant than females. In the present work, we review the effects of sex hormones on immunity to protozoa and helminth parasites, which are the causal agents of several diseases in humans, and discuss the most recent research related to the role of sex steroids in the complex host-parasite relationship. © 2012 New York Academy of Sciences.

DNA typing of ancient parasite eggs from environmental samples identifies human and animal worm infections in Viking-age settlement

DEFF Research Database (Denmark)

Søe, Martin Jensen; Fredensborg, Brian Lund; Nejsum, Peter

Human worm infections have, to a large extent, been eradicated in countries with high sanitary standards by preventing the fecal-oral transmission of infective eggs. It is possible to study parasite infections among past populations by retrieving and analyzing parasite eggs using paleoparasitolog......-age. Further, eggs of the Liver Fluke (Fasciola hepatica), whose primary hosts are cows and sheep, are identified indicating that grazing animals were kept in close proximity of the settlement....

The most important parasites in Serbia involving the foodborne route of transmission

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Petrović, J. M.; Prodanov-Radulović, J. Z.; Vasilev, S. D.

2017-09-01

Food can be an important route for transmission of parasites to humans. Compared to other foodborne pathogens in Serbia, foodborne (or potentially foodborne) parasites do not get the attention they undoubtedly deserve. The aim of this article is to give an overview of the most important parasitic pathogens that can be transmitted by food, and that cause disease in humans: Echinococcus, Trichinella, Taenia solium and Toxoplasma gondii. For each of these pathogens, the severity of human diseases they cause, incidence, mortality and case fatality rate among humans in Serbia as well as their prevalence in animal species in Serbia are described. Some of the described foodborne parasites can induce severe disease symptoms in humans associated with high case fatality rates, while others can cause massive outbreaks. All of the aforementioned parasites occur throughout Serbia and cause both severe public health problems and substantial economic losses in livestock production. In conclusion, the control measures of foodborne parasites certainly need to include education of farmers and improvement of veterinary sanitary measures in animal farming and animal waste control.

Probability of Transmission of Malaria from Mosquito to Human Is Regulated by Mosquito Parasite Density in Naïve and Vaccinated Hosts.

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Thomas S Churcher

2017-01-01

Full Text Available Over a century since Ronald Ross discovered that malaria is caused by the bite of an infectious mosquito it is still unclear how the number of parasites injected influences disease transmission. Currently it is assumed that all mosquitoes with salivary gland sporozoites are equally infectious irrespective of the number of parasites they harbour, though this has never been rigorously tested. Here we analyse >1000 experimental infections of humans and mice and demonstrate a dose-dependency for probability of infection and the length of the host pre-patent period. Mosquitoes with a higher numbers of sporozoites in their salivary glands following blood-feeding are more likely to have caused infection (and have done so quicker than mosquitoes with fewer parasites. A similar dose response for the probability of infection was seen for humans given a pre-erythrocytic vaccine candidate targeting circumsporozoite protein (CSP, and in mice with and without transfusion of anti-CSP antibodies. These interventions prevented infection more efficiently from bites made by mosquitoes with fewer parasites. The importance of parasite number has widespread implications across malariology, ranging from our basic understanding of the parasite, how vaccines are evaluated and the way in which transmission should be measured in the field. It also provides direct evidence for why the only registered malaria vaccine RTS,S was partially effective in recent clinical trials.

The Clp Chaperones and Proteases of the Human Malaria Parasite Plasmodium falciparum

Energy Technology Data Exchange (ETDEWEB)

Bakkouri, Majida El; Pow, Andre; Mulichak, Anne; Cheung, Kevin L.Y.; Artz, Jennifer D.; Amani, Mehrnaz; Fell, Stuart; de Koning-Ward, Tania F.; Goodman, C. Dean; McFadden, Geoffrey I.; Ortega, Joaquin; Hui, Raymond; Houry, Walid A. (McMaster U.); (Melbourne); (Toronto); (Deakin); (HWMRI)

2015-02-09

The Clp chaperones and proteases play an important role in protein homeostasis in the cell. They are highly conserved across prokaryotes and found also in the mitochondria of eukaryotes and the chloroplasts of plants. They function mainly in the disaggregation, unfolding and degradation of native as well as misfolded proteins. Here, we provide a comprehensive analysis of the Clp chaperones and proteases in the human malaria parasite Plasmodium falciparum. The parasite contains four Clp ATPases, which we term PfClpB1, PfClpB2, PfClpC and PfClpM. One PfClpP, the proteolytic subunit, and one PfClpR, which is an inactive version of the protease, were also identified. Expression of all Clp chaperones and proteases was confirmed in blood-stage parasites. The proteins were localized to the apicoplast, a non-photosynthetic organelle that accommodates several important metabolic pathways in P. falciparum, with the exception of PfClpB2 (also known as Hsp101), which was found in the parasitophorous vacuole. Both PfClpP and PfClpR form mostly homoheptameric rings as observed by size-exclusion chromatography, analytical ultracentrifugation and electron microscopy. The X-ray structure of PfClpP showed the protein as a compacted tetradecamer similar to that observed for Streptococcus pneumoniae and Mycobacterium tuberculosis ClpPs. Our data suggest the presence of a ClpCRP complex in the apicoplast of P. falciparum.

Host-seeking behaviors of mosquitoes experimentally infected with sympatric field isolates of the human malaria parasite Plasmodium falciparum: no evidence for host manipulation

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Amélie eVantaux

2015-08-01

Full Text Available Previous studies have shown that Plasmodium parasites can manipulate mosquito feeding behaviours such as motivation and avidity to feed on vertebrate hosts, in ways that increase the probability of parasite transmission. These studies, however, have been mainly carried out on non-natural and/or laboratory based model systems and hence may not reflect what occurs in the field. We now need to move closer to the natural setting, if we are to fully capture the ecological and evolutionary consequences of these parasite-induced behavioral changes. As part of this effort, we conducted a series of experiments to investigate the long and short-range behavioural responses to human stimuli in the mosquito Anopheles coluzzii during different stages of infection with sympatric field isolates of the human malaria parasite Plasmodium falciparum in Burkina Faso. First, we used a dual-port olfactometer designed to take advantage of the whole body odor to gauge mosquito long-range host-seeking behaviors. Second, we used a locomotor activity monitor system to assess mosquito short-range behaviors. Compared to control uninfected mosquitoes, P. falciparum infection had no significant effect neither on long-range nor on short-range behaviors both at the immature and mature stages. This study, using a natural mosquito-malaria parasite association, indicates that manipulation of vector behavior may not be a general phenomenon. We speculate that the observed contrasting phenotypes with model systems might result from coevolution of the human parasite and its natural vector. Future experiments, using other sympatric malaria mosquito populations or species are required to test this hypothesis. In conclusion, our results highlight the importance of following up discoveries in laboratory model systems with studies on natural parasite–mosquito interactions to accurately predict the epidemiological, ecological and evolutionary consequences of parasite manipulation of vector

Parasites of importance for human health in Nigerian dogs: high prevalence and limited knowledge of pet owners

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Heukelbach Jorg

2008-12-01

Full Text Available Abstract Background Dogs are the most common pet animals worldwide. They may harbour a wide range of parasites with zoonotic potential, thus causing a health risk to humans. In Nigeria, epidemiological knowledge on these parasites is limited. Methods In a community-based study, we examined 396 dogs in urban and rural areas of Ilorin (Kwara State, Central Nigeria for ectoparasites and intestinal helminths. In addition, a questionnaire regarding knowledge and practices was applied to pet owners. Results Nine ectoparasite species belonging to four taxa and six intestinal helminth species were identified: fleas (Ctenocephalides canis, Pulex irritans, Tunga penetrans, mites (Demodex canis, Otodectes sp., Sarcoptes scabiei var. canis, ticks (Rhipicephalus sanguineus, Ixodes sp., and lice (Trichodectes canis; and Toxocara canis, Ancylostoma sp., Trichuris vulpis, Dipylidium caninum, Taenidae and Strongyloides sp. Overall prevalence of ectoparasites was 60.4% and of intestinal helminths 68.4%. The occurrence of C. canis, R. sanguineus, T. canis, Ancylostoma sp. and T. vulpis was most common (prevalence 14.4% to 41.7%. Prevalence patterns in helminths were age-dependent, with T. canis showing a decreasing prevalence with age of host, and a reverse trend in other parasite species. Knowledge regarding zoonoses was very limited and the diseases not considered a major health problem. Treatment with antiparasitic drugs was more frequent in urban areas. Conclusion Parasites of importance for human health were highly prevalent in Nigerian dogs. Interventions should include health education provided to dog owners and the establishment of a program focusing on zoonotic diseases.

Prevalence of intestinal parasitic infections among patients ...

African Journals Online (AJOL)

Gastrointestinal helminths and protozoan parasites may cause mild, acute and chronic human infections. There is inadequate reliable information on the epidemiology of these parasites among patients attending tertiary hospitals in Tanzania. This retrospective study was conducted using hospital data obtained from the ...

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

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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.

Medicinal Plants: A Source of Anti-Parasitic Secondary Metabolites

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Michael Wink

2012-10-01

Full Text Available This review summarizes human infections caused by endoparasites, including protozoa, nematodes, trematodes, and cestodes, which affect more than 30% of the human population, and medicinal plants of potential use in their treatment. Because vaccinations do not work in most instances and the parasites have sometimes become resistant to the available synthetic therapeutics, it is important to search for alternative sources of anti-parasitic drugs. Plants produce a high diversity of secondary metabolites with interesting biological activities, such as cytotoxic, anti-parasitic and anti-microbial properties. These drugs often interfere with central targets in parasites, such as DNA (intercalation, alkylation, membrane integrity, microtubules and neuronal signal transduction. Plant extracts and isolated secondary metabolites which can inhibit protozoan parasites, such as Plasmodium, Trypanosoma, Leishmania, Trichomonas and intestinal worms are discussed. The identified plants and compounds offer a chance to develop new drugs against parasitic diseases. Most of them need to be tested in more detail, especially in animal models and if successful, in clinical trials.

An impossible journey? The development of Plasmodium falciparum NF54 in Culex quinquefasciatus.

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Julia Knöckel

Full Text Available 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.

Risk factors for gastrointestinal parasite infections of dogs living around protected areas of the Atlantic Forest: implications for human and wildlife health.

Science.gov (United States)

Curi, N H A; Paschoal, A M O; Massara, R L; Santos, H A; Guimarães, M P; Passamani, M; Chiarello, A G

2017-01-01

Despite the ubiquity of domestic dogs, their role as zoonotic reservoirs and the large number of studies concerning parasites in urban dogs, rural areas in Brazil, especially those at the wildlife-domestic animal-human interface, have received little attention from scientists and public health managers. This paper reports a cross-sectional epidemiological survey of gastrointestinal parasites of rural dogs living in farms around Atlantic Forest fragments. Through standard parasitological methods (flotation and sedimentation), 13 parasite taxa (11 helminths and two protozoans) were found in feces samples from dogs. The most prevalent were the nematode Ancylostoma (47%) followed by Toxocara (18%) and Trichuris (8%). Other less prevalent (dogs younger than one year were more likely to be infected with Toxocara, and purebred dogs with Trichuris. The number of cats in the households was positively associated with Trichuris infection, while male dogs and low body scores were associated with mixed infections. The lack of associations with dog free-ranging behavior and access to forest or villages indicates that infections are mostly acquired around the households. The results highlight the risk of zoonotic and wildlife parasite infections from dogs and the need for monitoring and controlling parasites of domestic animals in human-wildlife interface areas.

Immunisation with a Multivalent, Subunit Vaccine Reduces Patent Infection in a Natural Bovine Model of Onchocerciasis during Intense Field Exposure

Science.gov (United States)

Makepeace, Benjamin L.; Jensen, Siv Aina; Laney, Sandra J.; Nfon, Charles K.; Njongmeta, Leo M.; Tanya, Vincent N.; Williams, Steven A.; Bianco, Albert E.; Trees, Alexander J.

2009-01-01

Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Naïve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund's adjuvant or alum. The selected antigens were orthologues of O. volvulus recombinant proteins that had previously been shown to confer protection against filarial larvae in rodent models and, in some cases, were recognised by serum antibodies from putatively immune humans. The vaccine was highly immunogenic, eliciting a mixed IgG isotype response. Four weeks after the final immunisation, vaccinated and adjuvant-treated control calves were exposed to natural parasite transmission by the blackfly vectors in an area of Cameroon hyperendemic for O. ochengi. After 22 months, all the control animals had patent infections (i.e., microfilaridermia), compared with only 58% of vaccinated cattle (P = 0.015). This study indicates that vaccination to prevent patent infection may be an achievable goal in onchocerciasis, reducing both the pathology and transmissibility of the infection. The cattle model has also demonstrated its utility for preclinical vaccine discovery, although much research will be required to achieve the requisite target product profile of a clinical candidate. PMID:19901988

A novel PCR-based system for the detection of four species of human malaria parasites and Plasmodium knowlesi

Science.gov (United States)

Komaki-Yasuda, Kanako; Vincent, Jeanne Perpétue; Nakatsu, Masami; Kato, Yasuyuki; Ohmagari, Norio

2018-01-01

A microscopy-based diagnosis is the gold standard for the detection and identification of malaria parasites in a patient’s blood. However, the detection of cases involving a low number of parasites and the differentiation of species sometimes requires a skilled microscopist. Although PCR-based diagnostic methods are already known to be very powerful tools, the time required to apply such methods is still much longer in comparison to traditional microscopic observation. Thus, improvements to PCR systems are sought to facilitate the more rapid and accurate detection of human malaria parasites Plasmodium falciparum, P. vivax, P. ovale, and P. malariae, as well as P. knowlesi, which is a simian malaria parasite that is currently widely distributed in Southeast Asia. A nested PCR that targets the small subunit ribosomal RNA genes of malaria parasites was performed using a “fast PCR enzyme”. In the first PCR, universal primers for all parasite species were used. In the second PCR, inner-specific primers, which targeted sequences from P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, were used. The PCR reaction time was reduced with the use of the “fast PCR enzyme”, with only 65 minutes required to perform the first and second PCRs. The specific primers only reacted with the sequences of their targeted parasite species and never cross-reacted with sequences from other species under the defined PCR conditions. The diagnoses of 36 clinical samples that were obtained using this new PCR system were highly consistent with the microscopic diagnoses. PMID:29370297

A novel PCR-based system for the detection of four species of human malaria parasites and Plasmodium knowlesi.

Directory of Open Access Journals (Sweden)

Kanako Komaki-Yasuda

Full Text Available A microscopy-based diagnosis is the gold standard for the detection and identification of malaria parasites in a patient's blood. However, the detection of cases involving a low number of parasites and the differentiation of species sometimes requires a skilled microscopist. Although PCR-based diagnostic methods are already known to be very powerful tools, the time required to apply such methods is still much longer in comparison to traditional microscopic observation. Thus, improvements to PCR systems are sought to facilitate the more rapid and accurate detection of human malaria parasites Plasmodium falciparum, P. vivax, P. ovale, and P. malariae, as well as P. knowlesi, which is a simian malaria parasite that is currently widely distributed in Southeast Asia. A nested PCR that targets the small subunit ribosomal RNA genes of malaria parasites was performed using a "fast PCR enzyme". In the first PCR, universal primers for all parasite species were used. In the second PCR, inner-specific primers, which targeted sequences from P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi, were used. The PCR reaction time was reduced with the use of the "fast PCR enzyme", with only 65 minutes required to perform the first and second PCRs. The specific primers only reacted with the sequences of their targeted parasite species and never cross-reacted with sequences from other species under the defined PCR conditions. The diagnoses of 36 clinical samples that were obtained using this new PCR system were highly consistent with the microscopic diagnoses.

Development of an Epidemiological Database Management, Extraction, and Analysis System (EPISYS)

Science.gov (United States)

1992-07-01

Cestode Infections 106 11 Trichiniasis 107 11 Filarial Infections 108 11 Ancylostomiasis 109 11 Other Intestinal Helminthiasis 110 11 Other and...UnspecifiMd Helminthiasis 111 II Unspecified Intestinal Parasitism 112 9 Toxoplasmosis 113 6 Urogenital Trichomoniasis 114 10 Pediculosis 115 10 Acariasis 116

Comparative studies on the biology and filarial susceptibility of selected blood-feeding and autogenous Aedes togoi sub-colonies

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Anuluck Junkum

2003-06-01

Full Text Available Blood-feeding and autogenous sub-colonies were selected from a laboratory, stock colony of Aedes togoi, which was originally collected from Koh Nom Sao, Chanthaburi province, Southeast Thailand. Comparative biology and filarial susceptibility between the two sub-colonies (blood-feeding: F11, F13; autogeny: F38, F40 were investigated to evaluate their viability and vectorial capacity. The results of comparison on biology revealed intraspecific differences, i.e., the average egg deposition/gravid female (F11/F38; F13/F40, embryonation rate (F13/F40, hatchability rate (F11/F38; F13/F40, egg width (F11/F38, wing length of females (F13/F40, and wing length and width of males (F11/F38 in the blood-feeding sub-colony were significantly greater than that in the autogenous sub-colony; and egg length (F11/F38 and width (F13/F40, and mean longevity of adult females (F11/F38 and males (F13/F40 in the blood-feeding sub-colony were significantly less than that in the autogenous sub-colony. The results of comparison on filarial susceptibility demonstrated that both sub-colonies yielded similar susceptibilities to Brugia malayi [blood-feeding/autogeny = 56.7% (F11/53.3%(F38, 60%(F13/83.3%(F40] and Dirofilaria immitis [blood-feeding/autogeny = 85.7%(F11/75%(F38, 45%(F13/29.4%(F40], suggesting autogenous Ae. togoi sub-colony was an efficient laboratory vector in study of filariasis.

SURVEY OF HOUSE RAT INTESTINAL PARASITES FROM SURABAYA DISTRICT, EAST JAVA, INDONESIA THAT CAN CAUSE OPPORTUNISTIC INFECTIONS IN HUMANS.

Science.gov (United States)

Prasetyo, R H

2016-03-01

The purpose of this study was to investigate the prevalence of house rat zoonotic intestinal parasites from Surabaya District, East Java, Indonesia that have the potential to cause opportunistic infection in humans. House rat fecal samples were collected from an area of Surabaya District with a dense rat population during May 2015. Intestinal parasites were detected microscopically using direct smear of feces stained with Lugol's iodine and modified Ziehl-Neelsen stains. The fecal samples were also cultured for Strongyloides stercoralis. Ninety-eight house rat fecal samples were examined. The potential opportunistic infection parasite densities found in those samples were Strongyloides stercoralis in 53%, Hymenolepis nana in 42%, Cryptosporidium spp in 33%, and Blastocystis spp in 6%. This is the first report of this kind in Surabaya District. Measures need to be taken to control the house rat population in the study area to reduce the risk of the public health problem. Keywords: zoonotic intestinal parasites, opportunistic infection, house rat, densely populated area, Indonesia

Non-biting cyclorrhaphan flies (Diptera) as carriers of intestinal human parasites in slum areas of Addis Ababa, Ethiopia.

Science.gov (United States)

Getachew, Sisay; Gebre-Michael, Teshome; Erko, Berhanu; Balkew, Meshesha; Medhin, Girmay

2007-09-01

A study was conducted to determine the role of non-biting cyclorrhaphan flies as carriers of intestinal parasites in slum areas of Addis Ababa from January 2004 to June 2004. A total of 9550 flies, comprising of at least seven species were collected from four selected sites and examined for human intestinal parasites using the formol-ether concentration method. The dominant fly species was Chrysomya rufifacies (34.9%) followed by Musca domestica (31%), Musca sorbens (20.5.%), Lucina cuprina (6.8%), Sarcophaga sp. (2.8%), Calliphora vicina (2.2%) and Wohlfahrtia sp. (1.8%). Six intestinal helminths (Ascaris lumbricoides, Trichuris trichiura, hookworms, Hymenolepis nana, Taenia spp. and Strongyloides stercoralis) and at least four protozoan parasites (Entamoeba histolytica/dispar, Entamoeba coli, Giardia lamblia and Cryptosporidium sp.) were isolated from both the external and gut contents of the flies. A. lumbricoides and T. trichiura among the helminths and E. histolytica/dispar and E. coli among the protozoans were the dominant parasites detected both on the external and in the gut contents of the flies, but occurring more in the latter. Among the flies, C. rufifacies and M. sorbens were the highest carriers of the helminth and protozoan parasites, respectively. The public health significance of these findings is highlighted.

Rodent malaria parasites : genome organization & comparative genomics

NARCIS (Netherlands)

Kooij, Taco W.A.

2006-01-01

The aim of the studies described in this thesis was to investigate the genome organization of rodent malaria parasites (RMPs) and compare the organization and gene content of the genomes of RMPs and the human malaria parasite P. falciparum. The release of the complete genome sequence of P.

Host-parasite interactions and ecology of the malaria parasite-a bioinformatics approach.

Science.gov (United States)

Izak, Dariusz; Klim, Joanna; Kaczanowski, Szymon

2018-04-25

Malaria remains one of the highest mortality infectious diseases. Malaria is caused by parasites from the genus Plasmodium. Most deaths are caused by infections involving Plasmodium falciparum, which has a complex life cycle. Malaria parasites are extremely well adapted for interactions with their host and their host's immune system and are able to suppress the human immune system, erase immunological memory and rapidly alter exposed antigens. Owing to this rapid evolution, parasites develop drug resistance and express novel forms of antigenic proteins that are not recognized by the host immune system. There is an emerging need for novel interventions, including novel drugs and vaccines. Designing novel therapies requires knowledge about host-parasite interactions, which is still limited. However, significant progress has recently been achieved in this field through the application of bioinformatics analysis of parasite genome sequences. In this review, we describe the main achievements in 'malarial' bioinformatics and provide examples of successful applications of protein sequence analysis. These examples include the prediction of protein functions based on homology and the prediction of protein surface localization via domain and motif analysis. Additionally, we describe PlasmoDB, a database that stores accumulated experimental data. This tool allows data mining of the stored information and will play an important role in the development of malaria science. Finally, we illustrate the application of bioinformatics in the development of population genetics research on malaria parasites, an approach referred to as reverse ecology.

Linking parasite populations in hosts to parasite populations in space through Taylor's law and the negative binomial distribution.

Science.gov (United States)

Cohen, Joel E; Poulin, Robert; Lagrue, Clément

2017-01-03

The spatial distribution of individuals of any species is a basic concern of ecology. The spatial distribution of parasites matters to control and conservation of parasites that affect human and nonhuman populations. This paper develops a quantitative theory to predict the spatial distribution of parasites based on the distribution of parasites in hosts and the spatial distribution of hosts. Four models are tested against observations of metazoan hosts and their parasites in littoral zones of four lakes in Otago, New Zealand. These models differ in two dichotomous assumptions, constituting a 2 × 2 theoretical design. One assumption specifies whether the variance function of the number of parasites per host individual is described by Taylor's law (TL) or the negative binomial distribution (NBD). The other assumption specifies whether the numbers of parasite individuals within each host in a square meter of habitat are independent or perfectly correlated among host individuals. We find empirically that the variance-mean relationship of the numbers of parasites per square meter is very well described by TL but is not well described by NBD. Two models that posit perfect correlation of the parasite loads of hosts in a square meter of habitat approximate observations much better than two models that posit independence of parasite loads of hosts in a square meter, regardless of whether the variance-mean relationship of parasites per host individual obeys TL or NBD. We infer that high local interhost correlations in parasite load strongly influence the spatial distribution of parasites. Local hotspots could influence control and conservation of parasites.

Are adequate methods available to detect protist parasites on fresh produce?

Science.gov (United States)

Human parasitic protists such as Cryptosporidium, Giardia and microsporidia contaminate a variety of fresh produce worldwide. Existing detection methods lack sensitivity and specificity for most foodborne parasites. Furthermore, detection has been problematic because these parasites adhere tenacious...

Glyoxalase diversity in parasitic protists.

Science.gov (United States)

Deponte, Marcel

2014-04-01

Our current knowledge of the isomerase glyoxalase I and the thioesterase glyoxalase II is based on a variety of prokaryotic and eukaryotic (model) systems with an emphasis on human glyoxalases. During the last decade, important insights on glyoxalase catalysis and structure-function relationships have also been obtained from parasitic protists. These organisms, including kinetoplastid and apicomplexan parasites, are particularly interesting, both because of their relevance as pathogens and because of their phylogenetic diversity and host-parasite co-evolution which has led to specialized organellar and metabolic adaptations. Accordingly, the glyoxalase repertoire and properties vary significantly among parasitic protists of different major eukaryotic lineages (and even between closely related organisms). For example, several protists have an insular or non-canonical glyoxalase. Furthermore, the structures and the substrate specificities of glyoxalases display drastic variations. The aim of the present review is to highlight such differences as well as similarities between the glyoxalases of parasitic protists and to emphasize the power of comparative studies for gaining insights into fundamental principles and alternative glyoxalase functions.

Lysine Deacetylase Inhibitors in Parasites: Past, Present, and Future Perspectives.

Science.gov (United States)

Hailu, Gebremedhin S; Robaa, Dina; Forgione, Mariantonietta; Sippl, Wolfgang; Rotili, Dante; Mai, Antonello

2017-06-22

Current therapies for human parasite infections rely on a few drugs, most of which have severe side effects, and their helpfulness is being seriously compromised by the drug resistance problem. Globally, this is pushing discovery research of antiparasitic drugs toward new agents endowed with new mechanisms of action. By using a "drug repurposing" strategy, histone deacetylase inhibitors (HDACi), which are presently clinically approved for cancer use, are now under investigation for various parasite infections. Because parasitic Zn 2+ - and NAD + -dependent HDACs play crucial roles in the modulation of parasite gene expression and many of them are pro-survival for several parasites under various conditions, they are now emerging as novel potential antiparasitic targets. This Perspective summarizes the state of knowledge of HDACi (both class I/II HDACi and sirtuin inhibitors) targeted to the main human parasitic diseases (schistosomiasis, malaria, trypanosomiasis, leishmaniasis, and toxoplasmosis) and provides visions into the main issues that challenge their development as antiparasitic agents.

Risk factors for gastrointestinal parasite infections of dogs living around protected areas of the Atlantic Forest: implications for human and wildlife health

Directory of Open Access Journals (Sweden)

N. H. A. Curi

Full Text Available Abstract Despite the ubiquity of domestic dogs, their role as zoonotic reservoirs and the large number of studies concerning parasites in urban dogs, rural areas in Brazil, especially those at the wildlife-domestic animal-human interface, have received little attention from scientists and public health managers. This paper reports a cross-sectional epidemiological survey of gastrointestinal parasites of rural dogs living in farms around Atlantic Forest fragments. Through standard parasitological methods (flotation and sedimentation, 13 parasite taxa (11 helminths and two protozoans were found in feces samples from dogs. The most prevalent were the nematode Ancylostoma (47% followed by Toxocara (18% and Trichuris (8%. Other less prevalent (<2% parasites found were Capillaria, Ascaridia, Spirocerca, Taeniidae, Acantocephala, Ascaris, Dipylidium caninum, Toxascaris, and the protozoans Cystoisospora and Eimeria. Mixed infections were found in 36% of samples, mostly by Ancylostoma and Toxocara. Previous deworming had no association with infections, meaning that this preventive measure is being incorrectly performed by owners. Regarding risk factors, dogs younger than one year were more likely to be infected with Toxocara, and purebred dogs with Trichuris. The number of cats in the households was positively associated with Trichuris infection, while male dogs and low body scores were associated with mixed infections. The lack of associations with dog free-ranging behavior and access to forest or villages indicates that infections are mostly acquired around the households. The results highlight the risk of zoonotic and wildlife parasite infections from dogs and the need for monitoring and controlling parasites of domestic animals in human-wildlife interface areas.

From malaria parasite point of view – Plasmodium falciparum evolution

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Agata Zerka

2015-12-01

Full Text Available Malaria is caused by infection with protozoan parasites belonging to the genus Plasmodium, which have arguably exerted the greatest selection pressure on humans in the history of our species. Besides humans, different Plasmodium parasites infect a wide range of animal hosts, from marine invertebrates to primates. On the other hand, individual Plasmodium species show high host specificity. The extraordinary evolution of Plasmodium probably began when a free-living red algae turned parasitic, and culminated with its ability to thrive inside a human red blood cell. Studies on the African apes generated new data on the evolution of malaria parasites in general and the deadliest human-specific species, Plasmodium falciparum, in particular. Initially, it was hypothesized that P. falciparum descended from the chimpanzee malaria parasite P. reichenowi, after the human and the chimp lineage diverged about 6 million years ago. However, a recently identified new species infecting gorillas, unexpectedly showed similarity to P. falciparum and was therefore named P. praefalciparum. That finding spurred an alternative hypothesis, which proposes that P. falciparum descended from its gorilla rather than chimp counterpart. In addition, the gorilla-to-human host shift may have occurred more recently (about 10 thousand years ago than the theoretical P. falciparum-P. reichenowi split. One of the key aims of the studies on Plasmodium evolution is to elucidate the mechanisms that allow the incessant host shifting and retaining the host specificity, especially in the case of human-specific species. Thorough understanding of these phenomena will be necessary to design effective malaria treatment and prevention strategies.

Immunodiagnosis of parasitic infections using nuclear techniques

International Nuclear Information System (INIS)

1985-07-01

This report documents the recommendations of the ''Advisory Group on Immunodiagnosis of Parasitic Infections Using Nuclear Techniques'' with a focus on malaria, schistosomiasis and filariasis. Radionuclide tracers are considered an important component of present and future immunological methods for the assessment of the host's humoral and cellular immunity to the parasite and the detection of parasite antigen(s) in human body fluids. The Advisory Group has concluded that there is a continuing need for the development and application of immunodiagnostic methods in parasitic diseases. This report concerns methods which are currently or potentially applicable to immunodiagnostic investigations in parasitic diseases. Reference is made, where appropriate, to recent developments in research which may lead to improvement and standardization of methods now available and the development of new methodology. Separate abstracts on various papers presented were prepared

Heartworm of swans and geese

Science.gov (United States)

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.

Mansonellosis at Medium Purus River (Brazilian Amazon - DOI: 10.3395/reciis.v2i1.113en

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Yara Leite Adami

2008-10-01

Full Text Available Mansonella ozzardi is a filarial autochthonous parasite of the American continent that is frequently found infecting human beings in the Brazilian Amazon. The human infection by M. ozzardi is still seen as non pathogenic despite the variety of symptoms related to it such as fever, articular pain, headache, lymphadenopathy, eosinophily and pruritic skins eruptions. During an expedition in the Acre State, we were able to visit the Kamikuã, an Indian village located along the Purus river, close to the city of Boca do Acre (Amazonas State. The inhabitants had been diagnosed as harboring dog´s worms (Dirofilaria immitis but our blood samples collections from some individuals evidenced M. ozzardi infections. In fact, human populations from endemic areas are always complaining about symptoms of M. ozzardi infection and remain living together with high parasitic loads in the expectation of correct diagnostic and treatment. Studies on mansonellosis chemotherapy and control should be carried out in order to add knowledge about the infection and to provide hope and answers for those who live in endemic areas.

Parasites and fungi as risk factors for human and animal health.

Science.gov (United States)

Góralska, Katarzyna; Błaszkowska, Joanna

2015-01-01

Recent literature data suggests that parasitic and fungal diseases, which pose a threat to both human and animal health, remain a clinical, diagnostic and therapeutic problem. Attention is increasingly paid to the role played by natural microbiota in maintaining homeostasis in humans. A particular emphasis is placed on the possibility of manipulating the human microbiota (permanent, transient, pathogenic) and macrobiota (e.g., Trichuris suis) to support the treatment of selected diseases such as Crohn's disease, obesity, diabetes and cancer. Emphasis is placed on important medical species whose infections not only impair health but can also be life threatening, such as Plasmodium falciparum, Echinococcus multilocularis and Baylisascaris procyonis, which expand into areas which have so far been uninhabited. This article also presents the epidemiology, diagnosis and treatment of opportunistic parasitoses imported from the tropics, which spread across large groups of people through human-to-human transmission (Enterobius vermicularis, Sarcoptes scabiei). It also discusses the problem of environmentally-conditioned parasitoses, particularly their etiological factors associated with food contaminated with invasive forms (Trichinella sp., Toxoplasma gondii). The analysis also concerns the presence of developmental forms of geohelminths (Toxocara sp.) and ectoparasites (ticks), which are vectors of serious human diseases (Lyme borreliosis, anaplasmosis, babesiosis), in the environment. Mycological topics contains rare cases of mycoses environmentally conditioned (CNS aspergillosis) and transmissions of these pathogens in a population of hospitalized individuals, as well as seeking new methods used to treat mycoses.

Prevalence of Parasitic Contamination

Science.gov (United States)

Ismail, Yazan

2016-01-01

One of the main ways in transmitting parasites to humans is through consuming contaminated raw vegetables. The aim of this study was to evaluate the prevalence of parasitological contamination (helminthes eggs, Giardia and Entamoeba histolytica cysts) of salad vegetables sold at supermarkets and street vendors in Amman and Baqa’a – Jordan. A total of 133 samples of salad vegetables were collected and examined for the prevalence of parasites. It was found that 29% of the samples were contaminated with different parasites. Of the 30 lettuce, 33 tomato, 42 parsley and 28 cucumber samples examined the prevalence of Ascaris spp. eggs was 43%, 15%, 21% and 4%; Toxocara spp. eggs was 30%, 0%, 0% and 4%; Giardia spp. cysts was 23%, 6%, 0% and 0%; Taenia/Echinococcus eggs was 20%, 0%, 5% and 0%; Fasciola hepatica eggs was 13%, 3%, 2% and 0%; and E. histolytica cysts was 10%, 6%, 0% and 0%, respectively. There was no significant difference in the prevalence of parasite in salad vegetables either between supermarkets and street vendors, or between Amman and Baqa’a, Ascaris spp. was found to be the highest prevalent parasite in salad vegetables from supermarkets and street vendors and from Amman and Baqa’a. Our results pointed out that, the parasitic contamination of salad vegetables found in our study might be caused by irrigating crops with faecal contaminated water. We concluded that salad vegetables sold in Amman and Baqa’a may cause a health risk to consumers.

Prevalence of parasites in soil samples in Tehran public places ...

African Journals Online (AJOL)

Results of our findings provide evidence that soil may play an important role in transmission of zoonotic parasite diseases to human. In addition, control of high population of animals such as stray dogs and cats is necessary to reduce the distribution of parasites. Key words: Prevalence, parasites, flotation method, Tehran.

Internal parasites of reptiles.

Science.gov (United States)

Raś-Noryńska, Małgorzata; Sokół, Rajmund

2015-01-01

Nowadays a growing number of exotic reptiles are kept as pets. The aim of this study was to determine the species of parasites found in reptile patients of veterinary practices in Poland. Fecal samples obtained from 76 lizards, 15 turtles and 10 snakes were examined by flotation method and direct smear stained with Lugol's iodine. In 63 samples (62.4%) the presence of parasite eggs and oocysts was revealed. Oocysts of Isospora spp. (from 33% to 100% of the samples, depending on the reptilian species) and Oxyurids eggs (10% to 75%) were predominant. In addition, isolated Eimeria spp. oocysts and Giardia intestinalis cysts were found, as well as Strongylus spp. and Hymenolepis spp. eggs. Pet reptiles are often infected with parasites, some of which are potentially dangerous to humans. A routine parasitological examination should be done in such animals.

Asexual populations of the human malaria parasite, Plasmodium falciparum, use a two-step genomic strategy to acquire accurate, beneficial DNA amplifications.

Directory of Open Access Journals (Sweden)

Jennifer L Guler

Full Text Available Malaria drug resistance contributes to up to a million annual deaths. Judicious deployment of new antimalarials and vaccines could benefit from an understanding of early molecular events that promote the evolution of parasites. Continuous in vitro challenge of Plasmodium falciparum parasites with a novel dihydroorotate dehydrogenase (DHODH inhibitor reproducibly selected for resistant parasites. Genome-wide analysis of independently-derived resistant clones revealed a two-step strategy to evolutionary success. Some haploid blood-stage parasites first survive antimalarial pressure through fortuitous DNA duplications that always included the DHODH gene. Independently-selected parasites had different sized amplification units but they were always flanked by distant A/T tracks. Higher level amplification and resistance was attained using a second, more efficient and more accurate, mechanism for head-to-tail expansion of the founder unit. This second homology-based process could faithfully tune DNA copy numbers in either direction, always retaining the unique DNA amplification sequence from the original A/T-mediated duplication for that parasite line. Pseudo-polyploidy at relevant genomic loci sets the stage for gaining additional mutations at the locus of interest. Overall, we reveal a population-based genomic strategy for mutagenesis that operates in human stages of P. falciparum to efficiently yield resistance-causing genetic changes at the correct locus in a successful parasite. Importantly, these founding events arise with precision; no other new amplifications are seen in the resistant haploid blood stage parasite. This minimizes the need for meiotic genetic cleansing that can only occur in sexual stage development of the parasite in mosquitoes.

Inca expansion and parasitism in the lluta valley: preliminary data.

Science.gov (United States)

Santoro, Calogero; Vinton, Sheila Dorsey; Reinhard, Karl J

2003-01-01

Assessing the impact of cultural change on parasitism has been a central goal in archaeoparasitology. The influence of civilization and the development of empires on parasitism has not been evaluated. Presented here is a preliminary analysis of the change in human parasitism associated with the Inca conquest of the Lluta Valley in Northern Chile. Changes in parasite prevalence are described. It can be seen that the change in life imposed on the inhabitants of the Lluta Valley by the Incas caused an increase in parasitism.

Dogs’ gastrointestinal parasites and their association with public health in Iran

OpenAIRE

Kohansal Mohammad Hasan; Fazaeli Asghar; Nourian Abbasali; Haniloo Ali; Kamali Koorosh

2017-01-01

Introduction: Dogs harbour zoonotic parasites that cause serious infections in humans, such as visceral larva migrans, ocular larva migrans, cystic echinococcosis, and alveolar echinococcosis. Studies on dogs’ gastrointestinal parasites in different geographical locations are required to increase knowledge of the risk of canine zoonoses in human populations.

Human-induced eutrophication maintains high parasite prevalence in breeding threespine stickleback populations.

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Budria, Alexandre; Candolin, Ulrika

2015-04-01

Anthropogenic activities are having profound impacts on species interactions, with further consequences for populations and communities. We investigated the influence that anthropogenic eutrophication has on the prevalence of the parasitic tapeworm Schistocephalus solidus in threespine stickleback Gasterosteus aculeatus populations. We caught stickleback from four areas along the coast of Finland, and within each area from one undisturbed and one eutrophied habitat. We found the prevalence of the parasite to be lower in the eutrophied habitats at the start of the breeding season, probably because of fewer piscivorous birds that transmit the parasite. However, while the prevalence of the parasite declined across the season in the undisturbed habitat, it did less so in eutrophied habitats. We discuss different processes that could be behind the differences, such as lower predation rate on infected fish, higher food availability and less dispersal in eutrophied habitats. We found no effect of eutrophication on the proportion of infected stickleback that entered reproductive condition. Together with earlier findings, this suggests that eutrophication increases the proportion of infected stickleback that reproduce. This could promote the evolution of less parasite resistant populations, with potential consequences for the viability of the interacting parties of the host-parasite system.

Mechanisms of host seeking by parasitic nematodes.

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Gang, Spencer S; Hallem, Elissa A

2016-07-01

The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors. Copyright © 2016 Elsevier B.V. All rights reserved.

Inca expansion and parasitism in the Lluta Valley: preliminary data

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Santoro Calogero

2003-01-01

Full Text Available Assessing the impact of cultural change on parasitism has been a central goal in archaeoparasitology. The influence of civilization and the development of empires on parasitism has not been evaluated. Presented here is a preliminary analysis of the change in human parasitism associated with the Inca conquest of the Lluta Valley in Northern Chile. Changes in parasite prevalence are described. It can be seen that the change in life imposed on the inhabitants of the Lluta Valley by the Incas caused an increase in parasitism.

The transcriptome of Trichuris suis--first molecular insights into a parasite with curative properties for key immune diseases of humans.

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Cinzia Cantacessi

Full Text Available Iatrogenic infection of humans with Trichuris suis (a parasitic nematode of swine is being evaluated or promoted as a biological, curative treatment of immune diseases, such as inflammatory bowel disease (IBD and ulcerative colitis, in humans. Although it is understood that short-term T. suis infection in people with such diseases usually induces a modified Th2-immune response, nothing is known about the molecules in the parasite that induce this response.As a first step toward filling the gaps in our knowledge of the molecular biology of T. suis, we characterised the transcriptome of the adult stage of this nematode employing next-generation sequencing and bioinformatic techniques. A total of ∼65,000,000 reads were generated and assembled into ∼20,000 contiguous sequences ( = contigs; ∼17,000 peptides were predicted and classified based on homology searches, protein motifs and gene ontology and biological pathway mapping.These analyses provided interesting insights into a number of molecular groups, particularly predicted excreted/secreted molecules (n = 1,288, likely to be involved in the parasite-host interactions, and also various molecules (n = 120 linked to chemokine, T-cell receptor and TGF-β signalling as well as leukocyte transendothelial migration and natural killer cell-mediated cytotoxicity, which are likely to be immuno-regulatory or -modulatory in the infected host. This information provides a conceptual framework within which to test the immunobiological basis for the curative effect of T. suis infection in humans against some immune diseases. Importantly, the T. suis transcriptome characterised herein provides a curated resource for detailed studies of the immuno-molecular biology of this parasite, and will underpin future genomic and proteomic explorations.

Current Perspectives of Telomerase Structure and Function in Eukaryotes with Emerging Views on Telomerase in Human Parasites.

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Dey, Abhishek; Chakrabarti, Kausik

2018-01-24

Replicative capacity of a cell is strongly correlated with telomere length regulation. Aberrant lengthening or reduction in the length of telomeres can lead to health anomalies, such as cancer or premature aging. Telomerase is a master regulator for maintaining replicative potential in most eukaryotic cells. It does so by controlling telomere length at chromosome ends. Akin to cancer cells, most single-cell eukaryotic pathogens are highly proliferative and require persistent telomerase activity to maintain constant length of telomere and propagation within their host. Although telomerase is key to unlimited cellular proliferation in both cases, not much was known about the role of telomerase in human parasites (malaria, Trypanosoma , etc.) until recently. Since telomerase regulation is mediated via its own structural components, interactions with catalytic reverse transcriptase and several factors that can recruit and assemble telomerase to telomeres in a cell cycle-dependent manner, we compare and discuss here recent findings in telomerase biology in cancer, aging and parasitic diseases to give a broader perspective of telomerase function in human diseases.

A global comparison of the human and T. brucei degradomes gives insights about possible parasite drug targets.

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Susan T Mashiyama

Full Text Available We performed a genome-level computational study of sequence and structure similarity, the latter using crystal structures and models, of the proteases of Homo sapiens and the human parasite Trypanosoma brucei. Using sequence and structure similarity networks to summarize the results, we constructed global views that show visually the relative abundance and variety of proteases in the degradome landscapes of these two species, and provide insights into evolutionary relationships between proteases. The results also indicate how broadly these sequence sets are covered by three-dimensional structures. These views facilitate cross-species comparisons and offer clues for drug design from knowledge about the sequences and structures of potential drug targets and their homologs. Two protease groups ("M32" and "C51" that are very different in sequence from human proteases are examined in structural detail, illustrating the application of this global approach in mining new pathogen genomes for potential drug targets. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it. These sequence and structure data, along with interactive versions of the protein similarity networks generated in this study, are available at http://babbittlab.ucsf.edu/resources.html.

A global comparison of the human and T. brucei degradomes gives insights about possible parasite drug targets.

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Mashiyama, Susan T; Koupparis, Kyriacos; Caffrey, Conor R; McKerrow, James H; Babbitt, Patricia C

2012-01-01

We performed a genome-level computational study of sequence and structure similarity, the latter using crystal structures and models, of the proteases of Homo sapiens and the human parasite Trypanosoma brucei. Using sequence and structure similarity networks to summarize the results, we constructed global views that show visually the relative abundance and variety of proteases in the degradome landscapes of these two species, and provide insights into evolutionary relationships between proteases. The results also indicate how broadly these sequence sets are covered by three-dimensional structures. These views facilitate cross-species comparisons and offer clues for drug design from knowledge about the sequences and structures of potential drug targets and their homologs. Two protease groups ("M32" and "C51") that are very different in sequence from human proteases are examined in structural detail, illustrating the application of this global approach in mining new pathogen genomes for potential drug targets. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it. These sequence and structure data, along with interactive versions of the protein similarity networks generated in this study, are available at http://babbittlab.ucsf.edu/resources.html.

Similarities and differences between helminth parasites and cancer cell lines in shaping human monocytes: Insights into parallel mechanisms of immune evasion.

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Prakash Babu Narasimhan

2018-04-01

Full Text Available A number of features at the host-parasite interface are reminiscent of those that are also observed at the host-tumor interface. Both cancer cells and parasites establish a tissue microenvironment that allows for immune evasion and may reflect functional alterations of various innate cells. Here, we investigated how the phenotype and function of human monocytes is altered by exposure to cancer cell lines and if these functional and phenotypic alterations parallel those induced by exposure to helminth parasites. Thus, human monocytes were exposed to three different cancer cell lines (breast, ovarian, or glioblastoma or to live microfilariae (mf of Brugia malayi-a causative agent of lymphatic filariasis. After 2 days of co-culture, monocytes exposed to cancer cell lines showed markedly upregulated expression of M1-associated (TNF-α, IL-1β, M2-associated (CCL13, CD206, Mreg-associated (IL-10, TGF-β, and angiogenesis associated (MMP9, VEGF genes. Similar to cancer cell lines, but less dramatically, mf altered the mRNA expression of IL-1β, CCL13, TGM2 and MMP9. When surface expression of the inhibitory ligands PDL1 and PDL2 was assessed, monocytes exposed to both cancer cell lines and to live mf significantly upregulated PDL1 and PDL2 expression. In contrast to exposure to mf, exposure to cancer cell lines increased the phagocytic ability of monocytes and reduced their ability to induce T cell proliferation and to expand Granzyme A+ CD8+ T cells. Our data suggest that despite the fact that helminth parasites and cancer cell lines are extraordinarily disparate, they share the ability to alter the phenotype of human monocytes.

Similarities and differences between helminth parasites and cancer cell lines in shaping human monocytes: Insights into parallel mechanisms of immune evasion.

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Narasimhan, Prakash Babu; Akabas, Leor; Tariq, Sameha; Huda, Naureen; Bennuru, Sasisekhar; Sabzevari, Helen; Hofmeister, Robert; Nutman, Thomas B; Tolouei Semnani, Roshanak

2018-04-01

A number of features at the host-parasite interface are reminiscent of those that are also observed at the host-tumor interface. Both cancer cells and parasites establish a tissue microenvironment that allows for immune evasion and may reflect functional alterations of various innate cells. Here, we investigated how the phenotype and function of human monocytes is altered by exposure to cancer cell lines and if these functional and phenotypic alterations parallel those induced by exposure to helminth parasites. Thus, human monocytes were exposed to three different cancer cell lines (breast, ovarian, or glioblastoma) or to live microfilariae (mf) of Brugia malayi-a causative agent of lymphatic filariasis. After 2 days of co-culture, monocytes exposed to cancer cell lines showed markedly upregulated expression of M1-associated (TNF-α, IL-1β), M2-associated (CCL13, CD206), Mreg-associated (IL-10, TGF-β), and angiogenesis associated (MMP9, VEGF) genes. Similar to cancer cell lines, but less dramatically, mf altered the mRNA expression of IL-1β, CCL13, TGM2 and MMP9. When surface expression of the inhibitory ligands PDL1 and PDL2 was assessed, monocytes exposed to both cancer cell lines and to live mf significantly upregulated PDL1 and PDL2 expression. In contrast to exposure to mf, exposure to cancer cell lines increased the phagocytic ability of monocytes and reduced their ability to induce T cell proliferation and to expand Granzyme A+ CD8+ T cells. Our data suggest that despite the fact that helminth parasites and cancer cell lines are extraordinarily disparate, they share the ability to alter the phenotype of human monocytes.

Parasite stress promotes homicide and child maltreatment

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Thornhill, Randy; Fincher, Corey L.

2011-01-01

Researchers using the parasite-stress theory of human values have discovered many cross-cultural behavioural patterns that inform a range of scholarly disciplines. Here, we apply the theory to major categories of interpersonal violence, and the empirical findings are supportive. We hypothesize that the collectivism evoked by high parasite stress is a cause of adult-on-adult interpersonal violence. Across the US states, parasite stress and collectivism each positively predicts rates of men's and women's slaying of a romantic partner, as well as the rate of male-honour homicide and of the motivationally similar felony-related homicide. Of these four types of homicide, wealth inequality has an independent effect only on rates of male-honour and felony-related homicide. Parasite stress and collectivism also positively predict cross-national homicide rates. Child maltreatment by caretakers is caused, in part, by divestment in offspring of low phenotypic quality, and high parasite stress produces more such offspring than low parasite stress. Rates of each of two categories of the child maltreatment—lethal and non-lethal—across the US states are predicted positively by parasite stress, with wealth inequality and collectivism having limited effects. Parasite stress may be the strongest predictor of interpersonal violence to date. PMID:22042922

Mechanisms of CNS invasion and damage by parasites.

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Kristensson, Krister; Masocha, Willias; Bentivoglio, Marina

2013-01-01

Invasion of the central nervous system (CNS) is a most devastating complication of a parasitic infection. Several physical and immunological barriers provide obstacles to such an invasion. In this broad overview focus is given to the physical barriers to neuroinvasion of parasites provided at the portal of entry of the parasites, i.e., the skin and epithelial cells of the gastrointestinal tract, and between the blood and the brain parenchyma, i.e., the blood-brain barrier (BBB). A description is given on how human pathogenic parasites can reach the CNS via the bloodstream either as free-living or extracellular parasites, by embolization of eggs, or within red or white blood cells when adapted to intracellular life. Molecular mechanisms are discussed by which parasites can interact with or pass across the BBB. The possible targeting of the circumventricular organs by parasites, as well as the parasites' direct entry to the brain from the nasal cavity through the olfactory nerve pathway, is also highlighted. Finally, examples are given which illustrate different mechanisms by which parasites can cause dysfunction or damage in the CNS related to toxic effects of parasite-derived molecules or to immune responses to the infection. Copyright © 2013 Elsevier B.V. All rights reserved.

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

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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.

Lysophosphatidylcholine Regulates Sexual Stage Differentiation in the Human Malaria Parasite Plasmodium falciparum.

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Brancucci, Nicolas M B; Gerdt, Joseph P; Wang, ChengQi; De Niz, Mariana; Philip, Nisha; Adapa, Swamy R; Zhang, Min; Hitz, Eva; Niederwieser, Igor; Boltryk, Sylwia D; Laffitte, Marie-Claude; Clark, Martha A; Grüring, Christof; Ravel, Deepali; Blancke Soares, Alexandra; Demas, Allison; Bopp, Selina; Rubio-Ruiz, Belén; Conejo-Garcia, Ana; Wirth, Dyann F; Gendaszewska-Darmach, Edyta; Duraisingh, Manoj T; Adams, John H; Voss, Till S; Waters, Andrew P; Jiang, Rays H Y; Clardy, Jon; Marti, Matthias

2017-12-14

Transmission represents a population bottleneck in the Plasmodium life cycle and a key intervention target of ongoing efforts to eradicate malaria. Sexual differentiation is essential for this process, as only sexual parasites, called gametocytes, are infective to the mosquito vector. Gametocyte production rates vary depending on environmental conditions, but external stimuli remain obscure. Here, we show that the host-derived lipid lysophosphatidylcholine (LysoPC) controls P. falciparum cell fate by repressing parasite sexual differentiation. We demonstrate that exogenous LysoPC drives biosynthesis of the essential membrane component phosphatidylcholine. LysoPC restriction induces a compensatory response, linking parasite metabolism to the activation of sexual-stage-specific transcription and gametocyte formation. Our results reveal that malaria parasites can sense and process host-derived physiological signals to regulate differentiation. These data close a critical knowledge gap in parasite biology and introduce a major component of the sexual differentiation pathway in Plasmodium that may provide new approaches for blocking malaria transmission. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Sexual reproduction and genetic exchange in parasitic protists.

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Weedall, Gareth D; Hall, Neil

2015-02-01

A key part of the life cycle of an organism is reproduction. For a number of important protist parasites that cause human and animal disease, their sexuality has been a topic of debate for many years. Traditionally, protists were considered to be primitive relatives of the 'higher' eukaryotes, which may have diverged prior to the evolution of sex and to reproduce by binary fission. More recent views of eukaryotic evolution suggest that sex, and meiosis, evolved early, possibly in the common ancestor of all eukaryotes. However, detecting sex in these parasites is not straightforward. Recent advances, particularly in genome sequencing technology, have allowed new insights into parasite reproduction. Here, we review the evidence on reproduction in parasitic protists. We discuss protist reproduction in the light of parasitic life cycles and routes of transmission among hosts.

Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

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Messlinger, Helena; Sebald, Heidi; Heger, Lukas; Dudziak, Diana; Bogdan, Christian; Schleicher, Ulrike

2018-01-01

Activated natural killer (NK) cells release interferon (IFN)-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani). When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis) were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL)-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs) of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells reduced the

Monocyte-Derived Signals Activate Human Natural Killer Cells in Response to Leishmania Parasites

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Helena Messlinger

2018-01-01

Full Text Available Activated natural killer (NK cells release interferon (IFN-γ, which is crucial for the control of intracellular pathogens such as Leishmania. In contrast to experimental murine leishmaniasis, the human NK cell response to Leishmania is still poorly characterized. Here, we investigated the interaction of human blood NK cells with promastigotes of different Leishmania species (Leishmania major, Leishmania mexicana, Leishmania infantum, and Leishmania donovani. When peripheral blood mononuclear cells or purified NK cells and monocytes (all derived from healthy blood donors from Germany without a history of leishmaniasis were exposed to promastigotes, NK cells showed increased surface expression of the activation marker CD69. The extent of this effect varied depending on the Leishmania species; differences between dermotropic and viscerotropic L. infantum strains were not observed. Upregulation of CD69 required direct contact between monocytes and Leishmania and was partly inhibitable by anti-interleukin (IL-18. Unexpectedly, IL-18 was undetectable in most of the supernatants (SNs of monocyte/parasite cocultures. Confocal fluorescence microscopy of non-permeabilized cells revealed that Leishmania-infected monocytes trans-presented IL-18 to NK cells. Native, but not heat-treated SNs of monocyte/Leishmania cocultures also induced CD69 on NK cells, indicating the involvement of a soluble heat-labile factor other than IL-18. A role for the NK cell-activating cytokines IL-1β, IL-2, IL-12, IL-15, IL-21, and IFN-α/β was excluded. The increase of CD69 was not paralleled by NK cell IFN-γ production or enhanced cytotoxicity. However, prior exposure of NK cells to Leishmania parasites synergistically increased their IFN-γ release in response to IL-12, which was dependent on endogenous IL-18. CD1c+ dendritic cells were identified as possible source of Leishmania-induced IL-12. Finally, we observed that direct contact between Leishmania and NK cells

Autophagy-related Atg8 localizes to the apicoplast of the human malaria parasite Plasmodium falciparum.

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Kei Kitamura

Full Text Available Autophagy is a membrane-mediated degradation process, which is governed by sequential functions of Atg proteins. Although Atg proteins are highly conserved in eukaryotes, protozoa possess only a partial set of Atg proteins. Nonetheless, almost all protozoa have the complete factors belonging to the Atg8 conjugation system, namely, Atg3, Atg4, Atg7, and Atg8. Here, we report the biochemical properties and subcellular localization of the Atg8 protein of the human malaria parasite Plasmodium falciparum (PfAtg8. PfAtg8 is expressed during intra-erythrocytic development and associates with membranes likely as a lipid-conjugated form. Fluorescence microscopy and immunoelectron microscopy show that PfAtg8 localizes to the apicoplast, a four membrane-bound non-photosynthetic plastid. Autophagosome-like structures are not observed in the erythrocytic stages. These data suggest that, although Plasmodium parasites have lost most Atg proteins during evolution, they use the Atg8 conjugation system for the unique organelle, the apicoplast.

A subset of group A-like var genes encodes the malaria parasite ligands for binding to human brain endothelial cells

DEFF Research Database (Denmark)

Claessens, Antoine; Adams, Yvonne; Ghumra, Ashfaq

2012-01-01

Cerebral malaria is the most deadly manifestation of infection with Plasmodium falciparum. The pathology of cerebral malaria is characterized by the accumulation of infected erythrocytes (IEs) in the microvasculature of the brain caused by parasite adhesins on the surface of IEs binding to human...... receptors on microvascular endothelial cells. The parasite and host molecules involved in this interaction are unknown. We selected three P. falciparum strains (HB3, 3D7, and IT/FCR3) for binding to a human brain endothelial cell line (HBEC-5i). The whole transcriptome of isogenic pairs of selected.......029) but not by antibodies from controls with uncomplicated malaria (Mann-Whitney test, P = 0.58). This work describes a binding phenotype for virulence-associated group A P. falciparum erythrocyte membrane protein 1 variants and identifies targets for interventions to treat or prevent cerebral malaria....

Chlorophyllin as a possible measure against vectors of human parasites and fish parasites

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Peter Rolf Richter

2014-06-01

Full Text Available Water soluble chlorophyll (chlorophyllin exerts pronounced photodynamic activity. Chlorophyllin is a potential remedy against mosquito larvae and aquatic stages in the life cycle of parasites as well as against ectoparasites in fish. In the recent years it was found that mosquito larvae and other pest organisms can be killed by means of photodynamic substances such as different porphyrin derivates (e.g. hematoporphyrin, meso-tri(N-methylpyridyl, meso-mono(N-tetra-decylpyridyl porphyrine, hematoporphyrin IX, or hermatoporphyrin formula (HPF. It was found that incubation of mosquito larvae in chlorophyllin solution and subsequent irradiation results in photodynamic destruction of the larvae. Incorporation of about 8 ng chlorophyllin per larvae was sufficient to induce its death. In fish mass cultivation ichthyophthiriosis is a severe parasitic protozoan disease caused by the ciliate Ichthyophthirius multifiliis. It was found that incubation of infected fishes in chlorophyllin and subsequent illumination reduced the number of trophonts significantly (more than 50 %. The fishes were not impaired. Chlorophyllin and other photodynamic substances may become a possible countermeasure against I. multifiliis and other ectoparasites in aquaculture. The effectiveness of chlorophyllin depends on light attenuation in the water body.

Pentastomiasis and other parasitic zoonoses from reptiles and amphibians.

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Pantchev, Nikola; Tappe, Dennis

2011-01-01

Reptiles are growing in popularity as pets.The colonization of reptiles and amphibians by parasites and the resulting disease conditions are the most common problems seen in captive animals.This review focuses on pentastomiasis and sparganosis, important parasitic zoonoses of reptiles and amphibians, respectively, and free living-amoebae. Humans are suitable accidental hosts for some pentastomid species (particularly Armillifer and Porocephalus). In geographical areas with special ethnics, such as in West and Central Africa, and East Asia, 8-45% of the human population can be affected. Usually the larvae are coincidentally found during abdominal surgeries. However, fatalities have been described. Extreme caution is necessary when handling infected reptiles. Ocular or cerebral sparganosis is not uncommonly found in humans in East Asia. This disease is caused by spargana, tapeworm larvae (plerocercoids) of Spirometra sp. The infection occurs when uncooked meat from reptiles or amphibians is applied to wounds or eyes and the parasites migrate directly to human tissue, or by consumption of contaminated food or water. As a consequence of the reptile's predatory behaviour, the full spectrum of endo- and ectoparasites from potential prey animals can be found as transiting parasites in the intestinal tract, e. g. Hymenolepis nana, Cryptosporidium (C.) muris, C parvum or Capillaria hepatica. Occasionally, free-living amoebae are also found in reptile faeces (Acanthamoeba, Naegleria, Hartmanella, Vahlkampfia or Echinamoeba sp.).

Taming Parasites by Tailoring Them

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Bingjian Ren

2017-07-01

Full Text Available The next-generation gene editing based on CRISPR (clustered regularly interspaced short palindromic repeats has been successfully implemented in a wide range of organisms including some protozoan parasites. However, application of such a versatile game-changing technology in molecular parasitology remains fairly underexplored. Here, we briefly introduce state-of-the-art in human and mouse research and usher new directions to drive the parasitology research in the years to come. In precise, we outline contemporary ways to embolden existing apicomplexan and kinetoplastid parasite models by commissioning front-line gene-tailoring methods, and illustrate how we can break the enduring gridlock of gene manipulation in non-model parasitic protists to tackle intriguing questions that remain long unresolved otherwise. We show how a judicious solicitation of the CRISPR technology can eventually balance out the two facets of pathogen-host interplay.

Neutrophils kill the parasite Trichomonas vaginalis using trogocytosis

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Mercer, Frances; Ng, Shek Hang; Brown, Taylor M.; Boatman, Grace; Johnson, Patricia J.

2018-01-01

T. vaginalis, a human-infective parasite, causes the most common nonviral sexually transmitted infection (STI) worldwide and contributes to adverse inflammatory disorders. The immune response to T. vaginalis is poorly understood. Neutrophils (polymorphonuclear cells [PMNs]) are the major immune cell present at the T. vaginalis–host interface and are thought to clear T. vaginalis. However, the mechanism of PMN clearance of T. vaginalis has not been characterized. We demonstrate that human PMNs rapidly kill T. vaginalis in a dose-dependent, contact-dependent, and neutrophil extracellular trap (NET)-independent manner. In contrast to phagocytosis, we observed that PMN killing of T. vaginalis involves taking “bites” of T. vaginalis prior to parasite death, using trogocytosis to achieve pathogen killing. Both trogocytosis and parasite killing are dependent on the presence of PMN serine proteases and human serum factors. Our analyses provide the first demonstration, to our knowledge, of a mammalian phagocyte using trogocytosis for pathogen clearance and reveal a novel mechanism used by PMNs to kill a large, highly motile target. PMID:29408891

Functions of myosin motors tailored for parasitism

DEFF Research Database (Denmark)

Mueller, Christina; Graindorge, Arnault; Soldati-Favre, Dominique

2017-01-01

Myosin motors are one of the largest protein families in eukaryotes that exhibit divergent cellular functions. Their roles in protozoans, a diverse group of anciently diverged, single celled organisms with many prominent members known to be parasitic and to cause diseases in human and livestock......, are largely unknown. In the recent years many different approaches, among them whole genome sequencing, phylogenetic analyses and functional studies have increased our understanding on the distribution, protein architecture and function of unconventional myosin motors in protozoan parasites. In Apicomplexa......, myosins turn out to be highly specialized and to exhibit unique functions tailored to accommodate the lifestyle of these parasites....

Susceptibility Testing of Medically Important Parasites.

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Genetu Bayih, Abebe; Debnath, Anjan; Mitre, Edward; Huston, Christopher D; Laleu, Benoît; Leroy, Didier; Blasco, Benjamin; Campo, Brice; Wells, Timothy N C; Willis, Paul A; Sjö, Peter; Van Voorhis, Wesley C; Pillai, Dylan R

2017-07-01

In the last 2 decades, renewed attention to neglected tropical diseases (NTDs) has spurred the development of antiparasitic agents, especially in light of emerging drug resistance. The need for new drugs has required in vitro screening methods using parasite culture. Furthermore, clinical laboratories sought to correlate in vitro susceptibility methods with treatment outcomes, most notably with malaria. Parasites with their various life cycles present greater complexity than bacteria, for which standardized susceptibility methods exist. This review catalogs the state-of-the-art methodologies used to evaluate the effects of drugs on key human parasites from the point of view of drug discovery as well as the need for laboratory methods that correlate with clinical outcomes. Copyright © 2017 American Society for Microbiology.

A Plasmodium falciparum strain expressing GFP throughout the parasite's life-cycle.

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Arthur M Talman

2010-02-01

Full Text Available The human malaria parasite Plasmodium falciparum is responsible for the majority of malaria-related deaths. Tools allowing the study of the basic biology of P. falciparum throughout the life cycle are critical to the development of new strategies to target the parasite within both human and mosquito hosts. We here present 3D7HT-GFP, a strain of P. falciparum constitutively expressing the Green Fluorescent Protein (GFP throughout the life cycle, which has retained its capacity to complete sporogonic development. The GFP expressing cassette was inserted in the Pf47 locus. Using this transgenic strain, parasite tracking and population dynamics studies in mosquito stages and exo-erythrocytic schizogony is greatly facilitated. The development of 3D7HT-GFP will permit a deeper understanding of the biology of parasite-host vector interactions, and facilitate the development of high-throughput malaria transmission assays and thus aid development of new intervention strategies against both parasite and mosquito.

A Plasmodium falciparum strain expressing GFP throughout the parasite's life-cycle.

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Talman, Arthur M; Blagborough, Andrew M; Sinden, Robert E

2010-02-10

The human malaria parasite Plasmodium falciparum is responsible for the majority of malaria-related deaths. Tools allowing the study of the basic biology of P. falciparum throughout the life cycle are critical to the development of new strategies to target the parasite within both human and mosquito hosts. We here present 3D7HT-GFP, a strain of P. falciparum constitutively expressing the Green Fluorescent Protein (GFP) throughout the life cycle, which has retained its capacity to complete sporogonic development. The GFP expressing cassette was inserted in the Pf47 locus. Using this transgenic strain, parasite tracking and population dynamics studies in mosquito stages and exo-erythrocytic schizogony is greatly facilitated. The development of 3D7HT-GFP will permit a deeper understanding of the biology of parasite-host vector interactions, and facilitate the development of high-throughput malaria transmission assays and thus aid development of new intervention strategies against both parasite and mosquito.

Fauna of Zoontic Parasites of Stray Dogs in Yasouj Suburbs in 2008

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A Moshfe

2011-04-01

Full Text Available Introduction & Objective: Dogs are among the closest animals to human residents and can by useful for human. A few of zoontic diseases are prevalent in Iran. Dogs are the reservoirs of many of these zoonosis and a major role in transmission of infection. The aim of this study was to determine the zoonotic parasitic fauna of stray dogs in Yasuj Materials & Methods: In this descriptive study which was conducted at Yasuj suburbs in 2008, 25 dogs’ corpses were necropsied and their tissues were studied for parasitic infections. Collected parasites were placed in special containers and stained for genus and species diagnosis based on their morphological features. The collected data were analyzed with the SPSS software, using descriptive analysis. Results: Of the 25 studied corpses, 23 dogs were infected with at least one parasite. Helminthic infections of dogs were consisted of: Taenia hydatigena, Mesocestoides sp., Echinococcus granulosus, Dipylidium caninum, Macracanthorhynchus hirudinaceus and Spirocerca lupi. Conclusion: Four of six detected helminthes in in dogs in this study are zoonotic parasites which are important in human diseases. Among them larval stage of Echinococcus granulosus which causes hydatid cyst disease in human is very important. Control programs should be implemented in this region to prevent these zoonotic diseases.

Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.

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de Oliveira, Thais C; Rodrigues, Priscila T; Menezes, Maria José; Gonçalves-Lopes, Raquel M; Bastos, Melissa S; Lima, Nathália F; Barbosa, Susana; Gerber, Alexandra L; Loss de Morais, Guilherme; Berná, Luisa; Phelan, Jody; Robello, Carlos; de Vasconcelos, Ana Tereza R; Alves, João Marcelo P; Ferreira, Marcelo U

2017-07-01

The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically diverse sites

Satellite technology and the control of parasitic diseases in Africa ...

African Journals Online (AJOL)

The potential application of these techniques in the surveillance, control and prevention of parasitic diseases in Africa is explored in this write-up. Keywords: surveillance, parasitic diseases, satellite techniques, remote sensing, Geographical Information System (GIS), Global Positioning Sytem (GPS), human and robotic, ...

Parasite-Derived Proteins for the Treatment of Allergies and Autoimmune Diseases

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Zhenyu Wu

2017-11-01

Full Text Available The morbidity associated with atopic diseases and immune dysregulation disorders such as asthma, food allergies, multiple sclerosis, atopic dermatitis, type 1 diabetes mellitus, and inflammatory bowel disease has been increasing all around the world over the past few decades. Although the roles of non-biological environmental factors and genetic factors in the etiopathology have been particularly emphasized, they do not fully explain the increase; for example, genetic factors in a population change very gradually. Epidemiological investigation has revealed that the increase also parallels a decrease in infectious diseases, especially parasitic infections. Thus, the reduced prevalence of parasitic infections may be another important reason for immune dysregulation. Parasites have co-evolved with the human immune system for a long time. Some parasite-derived immune-evasion molecules have been verified to reduce the incidence and harmfulness of atopic diseases in humans by modulating the immune response. More importantly, some parasite-derived products have been shown to inhibit the progression of inflammatory diseases and consequently alleviate their symptoms. Thus, parasites, and especially their products, may have potential applications in the treatment of autoimmune diseases. In this review, the potential of parasite-derived products and their analogs for use in the treatment of atopic diseases and immune dysregulation is summarized.

Paternity-parasitism trade-offs: a model and test of host-parasite cooperation in an avian conspecific brood parasite.

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Lyon, Bruce E; Hochachka, Wesley M; Eadie, John M

2002-06-01

Efforts to evaluate the evolutionary and ecological dynamics of conspecific brood parasitism in birds and other animals have focused on the fitness costs of parasitism to hosts and fitness benefits to parasites. However, it has been speculated recently that, in species with biparental care, host males might cooperate with parasitic females by allowing access to the host nest in exchange for copulations. We develop a cost-benefit model to explore the conditions under which such host-parasite cooperation might occur. When the brood parasite does not have a nest of her own, the only benefit to the host male is siring some of the parasitic eggs (quasi-parasitism). Cooperation with the parasite is favored when the ratio of host male paternity of his own eggs relative to his paternity of parasitic eggs exceeds the cost of parasitism. When the brood parasite has a nest of her own, a host male can gain additional, potentially more important benefits by siring the high-value, low-cost eggs laid by the parasite in her own nest. Under these conditions, host males should be even more likely to accept parasitic eggs in return for copulations with the parasitic female. We tested these predictions for American coots (Fulica americana), a species with a high frequency of conspecific brood parasitism. Multilocus DNA profiling indicated that host males did not sire any of the parasitic eggs laid in host nests, nor did they sire eggs laid by the parasite in her own nest. We used field estimates of the model parameters from a four-year study of coots to predict the minimum levels of paternity required for the costs of parasitism to be offset by the benefits of mating with brood parasites. Observed levels of paternity were significantly lower than those predicted under a variety of assumptions, and we reject the hypothesis that host males cooperated with parasitic females. Our model clarifies the specific costs and benefits that influence host-parasite cooperation and, more generally

The neurotropic parasite Toxoplasma gondii increases dopamine metabolism.

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Emese Prandovszky

Full Text Available The highly prevalent parasite Toxoplasma gondii manipulates its host's behavior. In infected rodents, the behavioral changes increase the likelihood that the parasite will be transmitted back to its definitive cat host, an essential step in completion of the parasite's life cycle. The mechanism(s responsible for behavioral changes in the host is unknown but two lines of published evidence suggest that the parasite alters neurotransmitter signal transduction: the disruption of the parasite-induced behavioral changes with medications used to treat psychiatric disease (specifically dopamine antagonists and identification of a tyrosine hydroxylase encoded in the parasite genome. In this study, infection of mammalian dopaminergic cells with T. gondii enhanced the levels of K+-induced release of dopamine several-fold, with a direct correlation between the number of infected cells and the quantity of dopamine released. Immunostaining brain sections of infected mice with dopamine antibody showed intense staining of encysted parasites. Based on these analyses, T. gondii orchestrates a significant increase in dopamine metabolism in neural cells. Tyrosine hydroxylase, the rate-limiting enzyme for dopamine synthesis, was also found in intracellular tissue cysts in brain tissue with antibodies specific for the parasite-encoded tyrosine hydroxylase. These observations provide a mechanism for parasite-induced behavioral changes. The observed effects on dopamine metabolism could also be relevant in interpreting reports of psychobehavioral changes in toxoplasmosis-infected humans.

Human Dirofilaria repens Infection in Romania: A Case Report

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Ioana Popescu

2012-01-01

Full Text Available Human dirofilariasis is a zoonotic infectious disease caused by the filarial nematodes of dogs Dirofilaria repens and Dirofilaria immitis. Depending on the species involved, human infections usually manifest as one cutaneous or visceral larva migrans that forms a painless nodule in the later course of disease. Dirofilariae are endemic in the Mediterranean, particularly in Italy. They are considered as emerging pathogens currently increasing their geographical range. We present one of the few known cases of human dirofilariasis caused by D. repens in Romania. The patient developed unusual and severe clinical manifestations that mimicked pathological conditions like cellulitis or deep venous thrombosis.

Trickle or clumped infection process? A stochastic model for the infection process of the parasitic roundworm of humans, Ascaris lumbricoides.

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Walker, Martin; Hall, Andrew; Basáñez, María-Gloria

2010-10-01

The importance of the mode of acquisition of infectious stages of directly-transmitted parasitic helminths has been acknowledged in population dynamics models; hosts may acquire eggs/larvae singly in a "trickle" type manner or in "clumps". Such models have shown that the mode of acquisition influences the distribution and dynamics of parasite loads, the stability of host-parasite systems and the rate of emergence of anthelmintic resistance, yet very few field studies have allowed these questions to be explored with empirical data. We have analysed individual worm weight data for the parasitic roundworm of humans, Ascaris lumbricoides, collected from a three-round chemo-expulsion study in Dhaka, Bangladesh, with the aim of discerning whether a trickle or a clumped infection process predominates. We found that hosts tend to harbour female worms of a similar weight, indicative of a clumped infection process, but acknowledged that unmeasured host heterogeneities (random effects) could not be completely excluded as a cause. Here, we complement our previous statistical analyses using a stochastic infection model to simulate sizes of individual A. lumbricoides infecting a population of humans. We use the intraclass correlation coefficient (ICC) as a quantitative measure of similarity among simulated worm sizes and explore the behaviour of this statistic under assumptions corresponding to trickle or clumped infections and unmeasured host heterogeneities. We confirm that both mechanisms are capable of generating aggregates of similar-sized worms, but that the particular pattern of ICCs described pre- and post-anthelmintic treatment in the data is more consistent with aggregation generated by clumped infections than by host heterogeneities alone. This provides support to the notion that worms may be acquired in clumps. We discuss our results in terms of the population biology of A. lumbricoides and highlight the significance of our modelling approach for the study of the

Enlightening the malaria parasite life cycle: bioluminescent Plasmodium in fundamental and applied research

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Giulia eSiciliano

2015-05-01

Full Text Available The unicellular protozoan parasites of the genus Plasmodium impose on human health worldwide the enormous burden of malaria. The possibility to genetically modify several species of malaria parasites represented a major advance in the possibility to elucidate their biology and is now turning laboratory lines of transgenic Plasmodium into precious weapons to fight malaria. Amongst the various genetically modified plasmodia, transgenic parasite lines expressing bioluminescent reporters have been essential to unveil mechanisms of parasite gene expression and to develop in vivo imaging approaches in mouse malaria models. Mainly the human malaria parasite Plasmodium falciparum and the rodent parasite Plasmodium berghei have been engineered to express bioluminescent reporters in almost all the developmental stages of the parasite along its complex life cycle between the insect and the vertebrate hosts. Plasmodium lines expressing conventional and improved luciferase reporters are now gaining a central role to develop cell based assays in the much needed search of new antimalarial drugs and to open innovative approaches for both fundamental and applied research in malaria.

Enlightening the malaria parasite life cycle: bioluminescent Plasmodium in fundamental and applied research.

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Siciliano, Giulia; Alano, Pietro

2015-01-01

The unicellular protozoan parasites of the genus Plasmodium impose on human health worldwide the enormous burden of malaria. The possibility to genetically modify several species of malaria parasites represented a major advance in the possibility to elucidate their biology and is now turning laboratory lines of transgenic Plasmodium into precious weapons to fight malaria. Amongst the various genetically modified plasmodia, transgenic parasite lines expressing bioluminescent reporters have been essential to unveil mechanisms of parasite gene expression and to develop in vivo imaging approaches in mouse malaria models. Mainly the human malaria parasite Plasmodium falciparum and the rodent parasite P. berghei have been engineered to express bioluminescent reporters in almost all the developmental stages of the parasite along its complex life cycle between the insect and the vertebrate hosts. Plasmodium lines expressing conventional and improved luciferase reporters are now gaining a central role to develop cell based assays in the much needed search of new antimalarial drugs and to open innovative approaches for both fundamental and applied research in malaria.

Ancient Human Parasites in Ethnic Chinese Populations.

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Yeh, Hui-Yuan; Mitchell, Piers D

2016-10-01

Whilst archaeological evidence for many aspects of life in ancient China is well studied, there has been much less interest in ancient infectious diseases, such as intestinal parasites in past Chinese populations. Here, we bring together evidence from mummies, ancient latrines, and pelvic soil from burials, dating from the Neolithic Period to the Qing Dynasty, in order to better understand the health of the past inhabitants of China and the diseases endemic in the region. Seven species of intestinal parasite have been identified, namely roundworm, whipworm, Chinese liver fluke, oriental schistosome, pinworm, Taenia sp. tapeworm, and the intestinal fluke Fasciolopsis buski . It was found that in the past, roundworm, whipworm, and Chinese liver fluke appear to have been much more common than the other species. While roundworm and whipworm remained common into the late 20th century, Chinese liver fluke seems to have undergone a marked decline in its prevalence over time. The iconic transport route known as the Silk Road has been shown to have acted as a vector for the transmission of ancient diseases, highlighted by the discovery of Chinese liver fluke in a 2,000 year-old relay station in northwest China, 1,500 km outside its endemic range.

Gastrointestinal parasites in feral cats and rodents from the Fernando de Noronha Archipelago, Brazil.

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Lima, Victor Fernando Santana; Ramos, Rafael Antonio Nascimento; Lepold, Raphael; Borges, João Carlos Gomes; Ferreira, Carlos Diógenes; Rinaldi, Laura; Cringoli, Giuseppe; Alves, Leucio Câmara

2017-01-01

Gastrointestinal parasites are important pathogens affecting animals, some of them are of medical and veterinary concern. Although the dynamic of parasitic infections is a complex phenomenon that has been studied under experimental conditions, it shows several gaps in knowledge, especially in insular regions where a confined population of animals and parasites co-exists. In this study was assessed the parasitism by endoparasite gastrointestinal in feral cats (n = 37) and rodents (n = 30) from the Fernando de Noronha Archipelago; in addition, the risk of human infection and ecological implications of these findings were discussed. Out of all samples analysed, 100% scored positive for the presence of gastrointestinal parasites in both feral cats and rodents. A total 17 genera and/or species of endoparasite gastrointestinal were identified, Ancylostoma sp., Strongyloides sp., Trichuris campanula and Toxocara cati were the parasites more frequently in feral cats. In rodents Eimeria sp., Strongyloides sp. and Trichuris muris were parasites more frequently herein detected. Human population living in this area are at risk of parasite infections due to the population of rodents and feral cats in the archipelago.

Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont.

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Michalski, Michelle L; Bain, Odile; Fischer, Kerstin; Fischer, Peter U; Kumar, Sanjay; Foster, Jeremy M

2010-04-01

Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus Pallas, 1780) that is vectored by black flies (Simuliidae) in many parts of the United States. In northwestern Wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). Unsheathed blood microfilariae from Wisconsin bears possess characters consistent with the original description of D. ursi, as do adult worms observed histologically and grossly. Immunohistochemistry was used to identify the Wolbachia endosymbiont in the hypodermis and lateral cords of an adult female D. ursi. Amplification of wsp, gatB, coxA, fbpA, and ftsZ bacterial sequences from parasite DNA confirmed the presence of Wolbachia, and molecular phylogenetic analysis of the Wolbachia ftsZ gene groups the endosymbiont with Wolbachia from D. immitis and D. repens. Phylogenetic analysis of D. ursi 5s rDNA sequence confirms the morphological observations grouping this parasite as a member of Dirofilaria, and within the Dirofilaria - Onchocerca clade of filarial nematodes. This is the first report of Wolbachia characterization and molecular phylogeny information for D. ursi.

Trickle or clumped infection process? An analysis of aggregation in the weights of the parasitic roundworm of humans, Ascaris lumbricoides.

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Walker, Martin; Hall, Andrew; Basáñez, María-Gloria

2010-10-01

Studying the distribution of parasitic helminth body size across a population of definitive hosts can advance our understanding of parasite population biology. Body size is typically correlated with egg production. Consequently, inequalities in body size have been frequently measured to infer variation in reproductive success (VRS). Body size is also related to parasite age (time since entering the definitive host) and potentially provides valuable information on the mode of acquisition and establishment of immature (larval) parasites within the host: whether parasites tend to establish singly or in aggregates. The mode of acquisition of soil-transmitted helminths has been a theoretical consideration in the parasitological literature but has eluded data-driven investigation. In this paper, we analyse individual Ascaris lumbricoides weight data collected from a cohort of human hosts before and after re-infection following curative treatment, and explore its distribution within and among individuals in the population. Lorenz curves and Gini coefficients indicate that levels of weight inequality (a proxy for VRS) in A.lumbricoides are lower than other published estimates from animal-helminth systems. We explore levels of intra-host weight aggregation using statistical models to estimate the intraclass correlation coefficient (ICC) while adjusting for covariates using a flexible fractional polynomial transformation approach capable of handling non-linear functional relationships. The estimated ICCs indicate that weights are aggregated within hosts both at equilibrium and after re-infection, suggesting that parasites may establish within the host in clumps. The implications of a clumped infection process are discussed in terms of ascariasis transmission dynamics, control and anthelmintic resistance. Copyright © 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Economic Holobiont: Influence of Parasites, Microbiota and Chemosignals on Economic Behavior

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Petr Houdek

2018-05-01

Full Text Available The article is a perspective on utilization of microorganisms and chemosignals in studying human economic behavior. Research in biological roots of economic development has already confirmed that parasitic pressure influenced the creation and development of cultural norms and institutions. However, other effects of microorganisms on human groups and individual decision-making and behavior are heavily understudied. The perspective discusses how parasitic infections, sexually transmitted organisms and microbiota (i.e., “human holobiont” could causally influence risk-seeking behavior, impulsivity, social dominance, empathy, political views and gender differences. As a case study, the parasite Toxoplasma gondii and its influence on economic preferences, personal characteristics and human appearance are examined. I also briefly review how chemosignals influence decision-making, particularly in the social preferences domain. I mention some predictions that arise from the paradigm of economic holobiont for the economic science. The conclusion summarizes limitations of the discussed findings and the stated speculations.

Isolation of intracellular parasites (Plasmodium falciparum) from culture using free-flow electrophoresis: separation of the free parasites according to stages.

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Heidrich, H G; Mrema, J E; Vander Jagt, D L; Reyes, P; Rieckmann, K H

1982-06-01

Parasitized human erythrocytes were concentrated from continuous cultures of Plasmodium falciparum from 5-7% up to 80-95% using Plasmagel. After aggregation of the cells with phythemagglutinin, the aggregated erythrocytes were fragmented by passing them, with minimal force, through successive nylon filters of decreasing pore size (100 microns-3 microns). The mixture of liberated, free parasites, intact erythrocytes and erythrocyte membrane vesicles was separated using free-flow electrophoresis. Most of the fractions containing free parasites did not show contamination with erythrocyte constituents as determined by light and electron microscopy, polyacrylamide gel electrophoresis, and enzymatic analysis. In addition, the various stages of free parasites of Plasmodium falciparum exhibited different electrical surface charges. Rings and trophozoites were highly negatively charged whereas schizonts and, in particular, merozoites showed low negative charges. Thus, the various stages could be isolated separate from each other.

A European network for food-borne parasites (Euro-FBP: meeting report on ‘Analytical methods for food-borne parasites in human and veterinary diagnostics and in food matrices’

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Christian Klotz

2017-11-01

Full Text Available Abstract Food-borne parasites (FBPs are a neglected topic in food safety, partly due to a lack of awareness of their importance for public health, especially as symptoms tend not to develop immediately after exposure. In addition, methodological difficulties with both diagnosis in infected patients and detection in food matrices result in under-detection and therefore the potential for underestimation of their burden on our societies. This, in consequence, leads to lower prioritization for basic research, e.g. for development new and more advanced detection methods for different food matrices and diagnostic samples, and thus a vicious circle of neglect and lack of progress is propagated. The COST Action FA1408, A European Network for Foodborne Parasites (Euro-FBP aims to combat the impact of FBP on public health by facilitating the multidisciplinary cooperation and partnership between groups of researchers and between researchers and stakeholders. The COST Action TD1302, the European Network for cysticercosis/taeniosis, CYSTINET, has a specific focus on Taenia solium and T. saginata, two neglected FBPs, and aims to advance knowledge and understanding of these zoonotic disease complexes via collaborations in a multidisciplinary scientific network. This report summarizes the results of a meeting within the Euro-FBP consortium entitled ‘Analytical methods for food-borne parasites in human and veterinary diagnostics and in food matrices’ and of the joined Euro-FBP and CYSTINET meeting.

Blastocystis, an unrecognized parasite: an overview of pathogenesis and diagnosis.

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Wawrzyniak, Ivan; Poirier, Philippe; Viscogliosi, Eric; Dionigia, Meloni; Texier, Catherine; Delbac, Frédéric; Alaoui, Hicham El

2013-10-01

Blastocystis sp. is among the few enteric parasites with a prevalence that often exceeds 5% in the general population of industrialized countries and can reach 30-60% in developing countries. This parasite is frequently found in people who are immunocompromised (patients with human immunodeficiency virus/acquired immunodeficiency syndrome or cancer) and a higher risk of Blastocystis sp. infection has been found in people with close animal contact. Such prevalence in the human population and the zoonotic potential naturally raise questions about the impact of these parasites on public health and has increased interest in this area. Recent in vitro and in vivo studies have shed new light on the pathogenic power of this parasite, suggesting that Blastocystis sp. infection is associated with a variety of gastrointestinal disorders, may play a significant role in irritable bowel syndrome, and may be linked with cutaneous lesions (urticaria). Despite recent significant advances in the knowledge of the extensive genetic diversity of this species, the identification of extracellular proteases as virulence factors and the publication of one isolate genome, many aspects of the biology of Blastocystis sp. remain poorly investigated. In this review, we investigate several biological aspects of Blastocystis sp. (diversity and epidemiology, diagnosis tools and pathophysiology). These data pave the way for the following challenges concerning Blastocystis sp. research: deciphering key biological mechanisms and pathways of this parasite and clarification of its clinical impact in humans.

Parasites and other infectious agents in marine finfish and shellfish species posing a hazard to human health (ToR b)

DEFF Research Database (Denmark)

Alfjorden, A.; Podolska, M.; Karaseva, T.

2015-01-01

Several parasites and other infectious agents frequently reported by the WGPDMO in the annual update of disease trends (ICES WGPDMO reports 1999–2015) have the potential to be harmful to human health if ingested in unprocessed or inadequate-ly/partly processed seafood. These include, but are not ...

The butterfly effect: parasite diversity, environment, and emerging disease in aquatic wildlife.

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Adlard, Robert D; Miller, Terrence L; Smit, Nico J

2015-04-01

Aquatic wildlife is increasingly subjected to emerging diseases often due to perturbations of the existing dynamic balance between hosts and their parasites. Accelerating changes in environmental factors, together with anthropogenic translocation of hosts and parasites, act synergistically to produce hard-to-predict disease outcomes in freshwater and marine systems. These outcomes are further complicated by the intimate links between diseases in wildlife and diseases in humans and domestic animals. Here, we explore the interactions of parasites in aquatic wildlife in terms of their biodiversity, their response to environmental change, their emerging diseases, and the contribution of humans and domestic animals to parasitic disease outcomes. This work highlights the clear need for interdisciplinary approaches to ameliorate disease impacts in aquatic wildlife systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Crystallization and preliminary crystallographic studies of a cysteine protease inhibitor from the human nematode parasite Ascaris lumbricoides

International Nuclear Information System (INIS)

Liu, Sanling; Dong, Jianmei; Mei, Guoqiang; Liu, Guiyun; Xu, Wei; Su, Zhong; Liu, Jinsong

2011-01-01

A recombinant cysteine protease inhibitor from the human nematode parasite A. lumbricoides has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.1 Å resolution. The cysteine protease inhibitor from Ascaris lumbricoides, a roundworm that lives in the human intestine, may be involved in the suppression of human immune responses. Here, the molecular cloning, protein expression and purification, preliminary crystallization and crystallographic characterization of the cysteine protease inhibitor from A. lumbricoides are reported. The rod-shaped crystal belonged to space group C2, with unit-cell parameters a = 99.40, b = 37.52, c = 62.92 Å, β = 118.26°. The crystal diffracted to 2.1 Å resolution and contained two molecules in the asymmetric unit

Dysfunctions at human intestinal barrier by water-borne protozoan parasites: lessons from cultured human fully differentiated colon cancer cell lines.

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Liévin-Le Moal, Vanessa

2013-06-01

Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier. © 2013 John Wiley & Sons Ltd.

Prevalence and Risk Factors of Human Intestinal Parasites in Roudehen, Tehran Province, Iran.

Science.gov (United States)

Hemmati, Nasrin; Razmjou, Elham; Hashemi-Hafshejani, Saeideh; Motevalian, Abbas; Akhlaghi, Lameh; Meamar, Ahmad Reza

2017-01-01

Intestinal parasitic infections are among the most common infections and health problems worldwide. Due to the lack of epidemiologic information of such infections, the prevalence of, and the risk factors for, enteric parasites were investigated in residents of Roudehen, Tehran Province, Iran. In this cross-sectional study, 561 triple fecal samples were collected through a two-stage cluster-sampling protocol from Jun to Dec 2014. The samples were examined by formalin-ether concentration, culture, and with molecular methods. The prevalence of enteric parasites was 32.7% (95% CI 27.3-38). Blastocystis sp. was the most common intestinal protozoan (28.4%; 95% CI 23.7-33.0). The formalin-ether concentration and culture methods detected Blastocystis sp., Entamoeba coli , Giardia intestinalis , Dientamoeba fragilis , Iodamoeba butschlii , Entamoeba complex cysts or trophozoite , Chilomastix mesnilii , and Enterobius vermicularis . Single-round PCR assay for Entamoeba complex were identified Entamoeba dispar and E. moshkovskii . E. histolytica was not observed in any specimen. Multivariate analysis showed a significant association of parasites with water source and close animal contact. There was no correlation between infections and gender, age, occupation, education, or travel history. Protozoan infections were more common than helminth infections. This study revealed a high prevalence of enteric protozoan parasite infection among citizens of Rodehen. As most of the species detected are transmitted through a water-resistant cyst, public and individual education on personal hygiene should be considered to reduce transmission of intestinal parasites in the population.

Pitting of malaria parasites and spherocyte formation

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Gichuki Charity W

2006-07-01

Full Text Available Abstract Background A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA but no intracellular parasites, support the idea of pitting. Methods An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide. Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. Results Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites as opposed to erythrophagocytosis (5.33% ± 0.95% (P Conclusion It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

Parasites and chronic renal failure

OpenAIRE

Mohammadi Manesh, Reza; Hosseini Safa, Ahmad; Sharafi, Seyedeh Maryam; Jafari, Rasool; Bahadoran, Mehran; Yousefi, Morteza; Nasri, Hamid; Yousofi Darani, Hossein

2014-01-01

Suppression of the human immune system results in an increase in susceptibility to infection by various infectious agents. Conditions such as AIDS, organ transplantation and chronic renal insufficiency (CRI) are the most important cause of insufficient immune response against infections. Long term renal disorders result in uremia, which can suppress human immune system. Parasitic infections are one of the most important factors indicating the public health problems of the societies. These inf...

Ecology of the gastrointestinal parasites of Colobus vellerosus at Boabeng-Fiema, Ghana: possible anthropozoonotic transmission.

Science.gov (United States)

Teichroeb, Julie A; Kutz, Susan J; Parkar, Unaiza; Thompson, R C Andrew; Sicotte, Pascale

2009-11-01

Parasite richness and prevalence in wild animals can be used as indicators of population and ecosystem health. In this study, the gastrointestinal parasites of ursine colobus monkeys (Colobus vellerosus) at the Boabeng-Fiema Monkey Sanctuary (BFMS), Ghana, were investigated. BFMS is a sacred grove where monkeys and humans have long lived in relatively peaceful proximity. Fecal samples (n = 109) were collected opportunistically from >27 adult and subadult males in six bisexual groups and one all-male band from July 2004 to August 2005. Using fecal floatation, we detected three protozoans (two Entamoeba sp., Isospora sp.), five nematodes (Ascaris sp., Enterobius sp., Trichuris sp., two strongyle sp.), and one digenean trematode. Using fluorescein labeled antibodies, we detected an additional protozoan (Giardia sp.), and with PCR techniques, we characterized this as G. duodenalis Assemblage B and also identified a protistan (Blastocystis sp., subtype 2). The most prevalent parasite species were G. duodenalis and Trichuris sp. Parasites were more prevalent in the long wet season than the long dry. Parasite prevalence did not vary by age, and average parasite richness did not differ by rank for males whose status remained unchanged. However, males that changed rank tended to show higher average parasite richness when they were lower ranked. Individuals that spent more time near human settlements had a higher prevalence of Isospora sp. that morphologically resembled the human species I. belli. The presence of this parasite and G. duodenalis Assemblage B indicates possible anthropozoonotic and/or zoonotic transmission between humans and colobus monkeys at this site.

Loa loa in the anterior chamber of the eye: A case report

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Barua P

2005-01-01

Full Text Available An unusual case of loiasis from Assam is reported here. Loa loa is a subcutaneous filarial parasite of man and is transmitted to humans by chrysops flies. The patient presented with foreign body sensation and visual disturbances of the right eye. Examination revealed a white coiled structure in the cornea.. Routine blood and other investigations were within normal limits. A live adult worm was extracted and identity was confirmed by microscopy to be Loa loa. Patient was treated with diethylcarbamazine and steroid. We found this case interesting as the worm was present in the anterior chamber - an unusual site and there were no other positive findings besides the lone worm.

How do humans affect wildlife nematodes?

Science.gov (United States)

Weinstein, Sara B.; Lafferty, Kevin D.

2015-01-01

Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

History of the discovery of the malaria parasites and their vectors

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Cox Francis EG

2010-02-01

Full Text Available Abstract Malaria is caused by infection with protozoan parasites belonging to the genus Plasmodium transmitted by female Anopheles species mosquitoes. Our understanding of the malaria parasites begins in 1880 with the discovery of the parasites in the blood of malaria patients by Alphonse Laveran. The sexual stages in the blood were discovered by William MacCallum in birds infected with a related haematozoan, Haemoproteus columbae, in 1897 and the whole of the transmission cycle in culicine mosquitoes and birds infected with Plasmodium relictum was elucidated by Ronald Ross in 1897. In 1898 the Italian malariologists, Giovanni Battista Grassi, Amico Bignami, Giuseppe Bastianelli, Angelo Celli, Camillo Golgi and Ettore Marchiafava demonstrated conclusively that human malaria was also transmitted by mosquitoes, in this case anophelines. The discovery that malaria parasites developed in the liver before entering the blood stream was made by Henry Shortt and Cyril Garnham in 1948 and the final stage in the life cycle, the presence of dormant stages in the liver, was conclusively demonstrated in 1982 by Wojciech Krotoski. This article traces the main events and stresses the importance of comparative studies in that, apart from the initial discovery of parasites in the blood, every subsequent discovery has been based on studies on non-human malaria parasites and related organisms.

Glycomic Analysis of Life Stages of the Human Parasite Schistosoma mansoni Reveals Developmental Expression Profiles of Functional and Antigenic Glycan Motifs

NARCIS (Netherlands)

Smit, C.H.; van Diepen, A.; Nguyen, D.L.; Wuhrer, M.; Hoffmann, K.F.; Deelder, A.M.; Hokke, C.H.

2015-01-01

Glycans present on glycoproteins and glycolipids of the major human parasite Schistosoma mansoni induce innate as well as adaptive immune responses in the host. To be able to study the molecular characteristics of schistosome infections it is therefore required to determine the expression profiles

Gastrointestinal parasites in feral cats and rodents from the Fernando de Noronha Archipelago, Brazil

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Victor Fernando Santana Lima

2017-11-01

Full Text Available Abstract Gastrointestinal parasites are important pathogens affecting animals, some of them are of medical and veterinary concern. Although the dynamic of parasitic infections is a complex phenomenon that has been studied under experimental conditions, it shows several gaps in knowledge, especially in insular regions where a confined population of animals and parasites co-exists. In this study was assessed the parasitism by endoparasite gastrointestinal in feral cats (n = 37 and rodents (n = 30 from the Fernando de Noronha Archipelago; in addition, the risk of human infection and ecological implications of these findings were discussed. Out of all samples analysed, 100% scored positive for the presence of gastrointestinal parasites in both feral cats and rodents. A total 17 genera and/or species of endoparasite gastrointestinal were identified, Ancylostoma sp., Strongyloides sp., Trichuris campanula and Toxocara cati were the parasites more frequently in feral cats. In rodents Eimeria sp., Strongyloides sp. and Trichuris muris were parasites more frequently herein detected. Human population living in this area are at risk of parasite infections due to the population of rodents and feral cats in the archipelago.

Tulbaghia violacea and Allium ursinum Extracts Exhibit Anti-Parasitic and Antimicrobial Activities.

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Krstin, Sonja; Sobeh, Mansour; Braun, Markus Santhosh; Wink, Michael

2018-02-02

Garlic has played an important role in culinary arts and remedies in the traditional medicine throughout human history. Parasitic infections represent a burden in the society of especially poor countries, causing more than 1 billion infections every year and leading to around one million deaths. In this study, we investigated the mode of anti-parasitic activity of "wild garlics" Tulbaghia violacea and Allium ursinum dichloromethane extracts against parasites Trypanosoma brucei brucei and Leishmania tarentolae with regard to their already known antimicrobial activity. We also evaluated their cytotoxic potential against human cells. Both extracts showed a relevant trypanocidal and leishmanicidal activity, although L. tarentolae was less sensitive. We determined that the probable mode of action of both extracts is the irreversible inhibition of the activity of Trypanosoma brucei trypanothione reductase enzyme. The extracts showed a mild cytotoxic activity against human keratinocytes. They also exhibited weak-in most cases comparable-antibacterial and antifungal activity. HPLC-MS/MS analysis showed that both extracts are abundant in sulfur compounds. Thus, for the first time, the ability of Allium ursinum and Tulbaghia violacea to kill Trypanosoma sp. and Leishmania sp. parasites, probably by binding to and inactivating sulfur-containing compounds essential for the survival of the parasite, is shown.

Tulbaghia violacea and Allium ursinum Extracts Exhibit Anti-Parasitic and Antimicrobial Activities

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Sonja Krstin

2018-02-01

Full Text Available Garlic has played an important role in culinary arts and remedies in the traditional medicine throughout human history. Parasitic infections represent a burden in the society of especially poor countries, causing more than 1 billion infections every year and leading to around one million deaths. In this study, we investigated the mode of anti-parasitic activity of “wild garlics” Tulbaghia violacea and Allium ursinum dichloromethane extracts against parasites Trypanosoma brucei brucei and Leishmania tarentolae with regard to their already known antimicrobial activity. We also evaluated their cytotoxic potential against human cells. Both extracts showed a relevant trypanocidal and leishmanicidal activity, although L. tarentolae was less sensitive. We determined that the probable mode of action of both extracts is the irreversible inhibition of the activity of Trypanosoma brucei trypanothione reductase enzyme. The extracts showed a mild cytotoxic activity against human keratinocytes. They also exhibited weak—in most cases comparable—antibacterial and antifungal activity. HPLC-MS/MS analysis showed that both extracts are abundant in sulfur compounds. Thus, for the first time, the ability of Allium ursinum and Tulbaghia violacea to kill Trypanosoma sp. and Leishmania sp. parasites, probably by binding to and inactivating sulfur-containing compounds essential for the survival of the parasite, is shown.

Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus

International Nuclear Information System (INIS)

Asojo, Oluwatoyin A.; Loukas, Alex; Inan, Mehmet; Barent, Rick; Huang, Jicai; Plantz, Brad; Swanson, Amber; Gouthro, Mark; Meagher, Michael M.; Hotez, Peter J.

2005-01-01

In order to clarify the structural basis of the pathogenesis-related-1 domain, Na-ASP-1, the first multi-domain ASP from the human hookworm parasite N. americanus, has been crystallized. 2.2 Å resolution data have been collected from a crystal belonging to the monoclinic space group P2 1 . Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 Å have been collected from a crystal that belongs to the monoclinic space group P2 1 with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit

Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus

Energy Technology Data Exchange (ETDEWEB)

Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu [Eppley Institute for Research in Cancer and Allied Diseases, 987696 Nebraska Medical Center, Omaha, NE 68198-7696 (United States); Loukas, Alex [Department of Microbiology and Tropical Medicine, The George Washington University Medical Center, Washington DC 20037 (United States); Division of Infectious Diseases and Immunology, Queensland Institute of Medical Research, Brisbane, QLD 4006 (Australia); Inan, Mehmet; Barent, Rick; Huang, Jicai; Plantz, Brad; Swanson, Amber; Gouthro, Mark; Meagher, Michael M. [Department of Chemical Engineering, The University of Nebraska-Lincoln, Lincoln, NE 68588-0643 (United States); Hotez, Peter J. [Department of Microbiology and Tropical Medicine, The George Washington University Medical Center, Washington DC 20037 (United States); Eppley Institute for Research in Cancer and Allied Diseases, 987696 Nebraska Medical Center, Omaha, NE 68198-7696 (United States)

2005-04-01

In order to clarify the structural basis of the pathogenesis-related-1 domain, Na-ASP-1, the first multi-domain ASP from the human hookworm parasite N. americanus, has been crystallized. 2.2 Å resolution data have been collected from a crystal belonging to the monoclinic space group P2{sub 1}. Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 Å have been collected from a crystal that belongs to the monoclinic space group P2{sub 1} with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit.

Intestinal Parasitic Infections in Bahir Dar and Risk Factors for Transmission

OpenAIRE

Erko, Berhanu; Medhin, Girmay; Birrie, Hailu

1995-01-01

A study of intestinal parasites and assessment of transmission factors were made in Bahir Dar town, northwestern Ethiopia. Out of 528 children examined by formolether concentration method over 95 % were found to harbour one or more intestinal parasites. Human behaviour and poor sanitary conditions appeared to be responsible for the transmission of geohelminths, faeco-orally transmitted amoebae and water-related schistosome parasites. Health education is suggested to play a vital role in the c...

Modelling environmental factors correlated with podoconiosis: a geospatial study of non-filarial elephantiasis.

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Molla, Yordanos B; Wardrop, Nicola A; Le Blond, Jennifer S; Baxter, Peter; Newport, Melanie J; Atkinson, Peter M; Davey, Gail

2014-06-20

The precise trigger of podoconiosis - endemic non-filarial elephantiasis of the lower legs - is unknown. Epidemiological and ecological studies have linked the disease with barefoot exposure to red clay soils of volcanic origin. Histopathology investigations have demonstrated that silicon, aluminium, magnesium and iron are present in the lower limb lymph node macrophages of both patients and non-patients living barefoot on these clays. We studied the spatial variation (variations across an area) in podoconiosis prevalence and the associated environmental factors with a goal to better understanding the pathogenesis of podoconiosis. Fieldwork was conducted from June 2011 to February 2013 in 12 kebeles (administrative units) in northern Ethiopia. Geo-located prevalence data and soil samples were collected and analysed along with secondary geological, topographic, meteorological and elevation data. Soil data were analysed for chemical composition, mineralogy and particle size, and were interpolated to provide spatially continuous information. Exploratory, spatial, univariate and multivariate regression analyses of podoconiosis prevalence were conducted in relation to primary (soil) and secondary (elevation, precipitation, and geology) covariates. Podoconiosis distribution showed spatial correlation with variation in elevation and precipitation. Exploratory analysis identified that phyllosilicate minerals, particularly clay (smectite and kaolinite) and mica groups, quartz (crystalline silica), iron oxide, and zirconium were associated with podoconiosis prevalence. The final multivariate model showed that the quantities of smectite (RR = 2.76, 95% CI: 1.35, 5.73; p = 0.007), quartz (RR = 1.16, 95% CI: 1.06, 1.26; p = 0.001) and mica (RR = 1.09, 95% CI: 1.05, 1.13; p < 0.001) in the soil had positive associations with podoconiosis prevalence. More quantities of smectite, mica and quartz within the soil were associated with podoconiosis prevalence. Together with previous

Transformation of the rodent malaria parasite Plasmodium chabaudi

OpenAIRE

Spence, Philip J; Cunningham, Deirdre; Jarra, William; Lawton, Jennifer; Langhorne, Jean; Thompson, Joanne

2011-01-01

The rodent malaria parasite Plasmodium chabaudi chabaudi shares many features with human malaria species, including P. falciparum, and is the in vivo model of choice for many aspects of malaria research in the mammalian host, from sequestration of parasitized erythrocytes, to antigenic variation and host immunity and immunopathology. this protocol describes an optimized method for the transformation of mature blood-stage P.c. chabaudi and a description of a vector that targets efficient, sing...

A novel progesterone receptor membrane component (PGRMC) in the human and swine parasite Taenia solium: implications to the host-parasite relationship.

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Aguilar-Díaz, Hugo; Nava-Castro, Karen E; Escobedo, Galileo; Domínguez-Ramírez, Lenin; García-Varela, Martín; Del Río-Araiza, Víctor H; Palacios-Arreola, Margarita I; Morales-Montor, Jorge

2018-03-09

We have previously reported that progesterone (P 4 ) has a direct in vitro effect on the scolex evagination and growth of Taenia solium cysticerci. Here, we explored the hypothesis that the P 4 direct effect on T. solium might be mediated by a novel steroid-binding parasite protein. By way of using immunofluorescent confocal microscopy, flow cytometry analysis, double-dimension electrophoresis analysis, and sequencing the corresponding protein spot, we detected a novel PGRMC in T. solium. Molecular modeling studies accompanied by computer docking using the sequenced protein, together with phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is from parasite origin. Our results show that P 4 in vitro increases parasite evagination and scolex size. Using immunofluorescent confocal microscopy, we detected that parasite cells showed expression of a P 4 -binding like protein exclusively located at the cysticercus subtegumental tissue. Presence of the P 4 -binding protein in cyst cells was also confirmed by flow cytometry. Double-dimension electrophoresis analysis, followed by sequencing the corresponding protein spot, revealed a protein that was previously reported in the T. solium genome belonging to a membrane-associated progesterone receptor component (PGRMC). Molecular modeling studies accompanied by computer docking using the sequenced protein showed that PGRMC is potentially able to bind steroid hormones such as progesterone, estradiol, testosterone and dihydrodrotestosterone with different affinities. Phylogenetic analysis and sequence alignment clearly demonstrated that T. solium PGRMC is related to a steroid-binding protein of Echinoccocus granulosus, both of them being nested within a cluster including similar proteins present in platyhelminths such as Schistocephalus solidus and Schistosoma haematobium. Progesterone may directly act upon T. solium cysticerci probably by binding to PGRMC. This research has implications in the

Prevalence of gastrointestinal parasites in domestic dogs in Tabasco, southeastern Mexico

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Oswaldo Margarito Torres-Chablé

Full Text Available Abstract The overall goal of this study was to estimate the prevalence of gastrointestinal (GI parasites in dogs in the city of Villahermosa in Tabasco, Mexico. The study population consisted of 302 owned dogs that had limited access to public areas. A fecal sample was collected from each animal and examined for GI parasites by conventional macroscopic analysis and centrifugal flotation. Fecal samples from 80 (26.5% dogs contained GI parasites. Of these, 58 (19.2% were positive for helminths and 22 (7.3% were positive for protozoan parasites. At least seven parasitic species were identified. The most common parasite was Ancylostoma caninum which was detected in 48 (15.9% dogs. Other parasites detected on multiple occasions were Cystoisospora spp. (n = 19, Toxocara canis (n = 7 and Giardia spp. (n = 3. Three additional parasites, Dipylidium caninum, Trichuris vulpis and Uncinaria spp., were each detected in a single dog. No mixed parasitic infections were identified. In summary, we report a moderately high prevalence of GI parasites in owned dogs in Villahermosa, Tabasco. Several parasitic species identified in this study are recognized zoonotic pathogens which illustrates the important need to routinely monitor and treat dogs that live in close proximity to humans for parasitic infections.

Prevalence and Risk Factors of Human Intestinal Parasites in Roudehen, Tehran Province, Iran

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Nasrin HEMMATI

2017-09-01

Full Text Available Background: Intestinal parasitic infections are among the most common infections and health problems worldwide. Due to the lack of epidemiologic information of such infections, the prevalence of, and the risk factors for, enteric parasites were investigated in residents of Roudehen, Tehran Province, Iran.Methods: In this cross-sectional study, 561 triple fecal samples were collected through a two-stage cluster-sampling protocol from Jun to Dec 2014. The samples were examined by formalin-ether concentration, culture, and with molecular methods.Results: The prevalence of enteric parasites was 32.7% (95% CI 27.3–38. Blastocystis sp. was the most common intestinal protozoan (28.4%; 95% CI 23.7–33.0. The formalin-ether concentration and culture methods detected Blastocystis sp., Entamoeba coli, Giardia intestinalis, Dientamoeba fragilis, Iodamoeba butschlii, Entamoeba complex cysts or trophozoite, Chilomastix mesnilii, and Enterobius vermicularis. Single-round PCR assay for Entamoeba complex were identified Entamoeba dispar and E. moshkovskii. E. histolytica was not observed in any specimen. Multivariate analysis showed a significant association of parasites with water source and close animal contact. There was no correlation between infections and gender, age, occupation, education, or travel history. Protozoan infections were more common than helminth infections.Conclusion: This study revealed a high prevalence of enteric protozoan parasite infection among citizens of Rodehen. As most of the species detected are transmitted through a water-resistant cyst, public and individual education on personal hygiene should be considered to reduce transmission of intestinal parasites in the population. 

Are all red algal parasites cut from the same cloth?

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Eric D. Salomaki

2014-12-01

Full Text Available Parasitism is a common life strategy throughout the eukaryotic tree of life. Many devastating human pathogens, including the causative agents of malaria and toxoplasmosis, have evolved from a photosynthetic ancestor. However, how an organism transitions from a photosynthetic to a parasitic life history strategy remains mostly unknown. This is largely because few systems present the opportunity to make meaningful comparisons between a parasite and a close free-living relative. Parasites have independently evolved dozens of times throughout the Florideophyceae (Rhodophyta, and often infect close relatives. The accepted evolutionary paradigm proposes that red algal parasites arise by first infecting a close relative and over time diversify and infect more distantly related species. This provides a natural evolutionary gradient of relationships between hosts and parasites that share a photosynthetic common ancestor. Elegant microscopic work in the late 20th century provided detailed insight into the infection cycle of red algal parasites and the cellular interactions between parasites and their hosts. Those studies led to the use of molecular work to further investigate the origins of the parasite organelles and reveal the evolutionary relationships between hosts and their parasites. Here we synthesize the research detailing the infection methods and cellular interactions between red algal parasites and their hosts. We offer an alternative hypothesis to the current dogma of red algal parasite evolution and propose that red algae can adopt a parasitic life strategy through multiple evolutionary pathways, including direct infection of distant relatives. Furthermore, we highlight potential directions for future research to further evaluate parasite evolution in red algae.

One stimulus-Two responses: Host and parasite life-history variation in response to environmental stress.

Science.gov (United States)

Gleichsner, Alyssa M; Cleveland, Jessica A; Minchella, Dennis J

2016-11-01

Climate change stressors will place different selective pressures on both parasites and their hosts, forcing individuals to modify their life-history strategies and altering the distribution and prevalence of disease. Few studies have investigated whether parasites are able to respond to host stress and respond by varying their reproductive schedules. Additionally, multiple environmental stressors can limit the ability of a host to respond adaptively to parasite infection. This study compared both host and parasite life-history parameters in unstressed and drought-stressed environments using the human parasite, Schistosoma mansoni, in its freshwater snail intermediate host. Snail hosts infected with the parasite demonstrated a significant reproductive burst during the prepatent period (fecundity compensation), but that response was absent in a drought-stressed environment. This is the first report of the elimination of host fecundity compensation to parasitism when exposed to additional environmental stress. More surprisingly, we found that infections in drought-stressed snails had significantly higher parasite reproductive outputs than infections in unstressed snails. The finding suggests that climate change may alter the infection dynamics of this human parasite. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Evidence that leishmania donovani utilizes a mannose receptor on human mononuclear phagocytes to establish intracellular parasitism

International Nuclear Information System (INIS)

Wilson, M.E.; Pearson, R.D.

1986-01-01

The pathogenic protozoan Leishmania donovani must gain entrance into mononuclear phagocytes to successfully parasitize man. The parasite's extracellular promastigote stage is ingested by human peripheral blood monocytes or monocyte-derived macrophages in the absence of serum, in a manner characteristic of receptor-mediated endocytosis. Remarkable similarities have been found between the macrophage receptor(s) for promastigotes and a previously characterized eucaryotic receptor system, the mannose/fucose receptor (MFR), that mediates the binding of zymosan particles and mannose- or fucose-terminal glycoconjugates to macrophages. Ingestion of promastigotes by monocyte-derived macrophages was inhibited by several MFR ligands; that is mannan, mannose-BSA and fucose-BSA. In contrast, promastigote ingestion by monocytes was unaffected by MFR ligands. Furthermore, attachment of promastigotes to macrophages, assessed by using cytochalasin D to prevent phagocytosis, was reduced 49.8% by mannan. Reorientation of the MFR to the ventral surface of the cell was achieved by plating macrophages onto mannan-coated coverslips, reducing MFR activity on the exposed cell surface by 94% as assessed by binding of 125 I-mannose-BSA. Under these conditions, ingestion of promastigotes was inhibited by 71.4%. Internalization of the MFR by exposure of macrophages to zymosan before infection with promastigotes resulted in a 62.3% decrease in parasite ingestion. Additionally, NH 4 Cl decreased macrophage ingestion of promastigotes by 38.2%. Subinhibitory concentration of NH 4 Cl (10 mM) and of mannan (0.25 mg/ml) together inhibited parsite ingestion by 76.4%

Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax.

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Thais C de Oliveira

2017-07-01

Full Text Available The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax.We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences, Peru (PER, n = 23, Colombia (COL, n = 31, and Mexico (MEX, n = 19.We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10-4 and 6.2 × 10-4 as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092. Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between parasite lineages from geographically

Systematic analysis of FKBP inducible degradation domain tagging strategies for the human malaria parasite Plasmodium falciparum.

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Mauro Ferreira de Azevedo

Full Text Available Targeted regulation of protein levels is an important tool to gain insights into the role of proteins essential to cell function and development. In recent years, a method based on mutated forms of the human FKBP12 has been established and used to great effect in various cell types to explore protein function. The mutated FKBP protein, referred to as destabilization domain (DD tag when fused with a native protein at the N- or C-terminus targets the protein for proteosomal degradation. Regulated expression is achieved via addition of a compound, Shld-1, that stabilizes the protein and prevents degradation. A limited number of studies have used this system to provide powerful insight into protein function in the human malaria parasite Plasmodium falciparum. In order to better understand the DD inducible system in P. falciparum, we studied the effect of Shld-1 on parasite growth, demonstrating that although development is not impaired, it is delayed, requiring the appropriate controls for phenotype interpretation. We explored the quantified regulation of reporter Green Fluorescent Protein (GFP and luciferase constructs fused to three DD variants in parasite cells either via transient or stable transfection. The regulation obtained with the original FKBP derived DD domain was compared to two triple mutants DD24 and DD29, which had been described to provide better regulation for C-terminal tagging in other cell types. When cloned to the C-terminal of reporter proteins, DD24 provided the strongest regulation allowing reporter activity to be reduced to lower levels than DD and to restore the activity of stabilised proteins to higher levels than DD29. Importantly, DD24 has not previously been applied to regulate proteins in P. falciparum. The possibility of regulating an exported protein was addressed by targeting the Ring-Infected Erythrocyte Surface Antigen (RESA at its C-terminus. The tagged protein demonstrated an important modulation of its

Genome-wide diversity and differentiation in New World populations of the human malaria parasite Plasmodium vivax

Science.gov (United States)

de Oliveira, Thais C.; Rodrigues, Priscila T.; Menezes, Maria José; Gonçalves-Lopes, Raquel M.; Bastos, Melissa S.; Lima, Nathália F.; Barbosa, Susana; Gerber, Alexandra L.; Loss de Morais, Guilherme; Berná, Luisa; Phelan, Jody; Robello, Carlos; de Vasconcelos, Ana Tereza R.

2017-01-01

Background The Americas were the last continent colonized by humans carrying malaria parasites. Plasmodium falciparum from the New World shows very little genetic diversity and greater linkage disequilibrium, compared with its African counterparts, and is clearly subdivided into local, highly divergent populations. However, limited available data have revealed extensive genetic diversity in American populations of another major human malaria parasite, P. vivax. Methods We used an improved sample preparation strategy and next-generation sequencing to characterize 9 high-quality P. vivax genome sequences from northwestern Brazil. These new data were compared with publicly available sequences from recently sampled clinical P. vivax isolates from Brazil (BRA, total n = 11 sequences), Peru (PER, n = 23), Colombia (COL, n = 31), and Mexico (MEX, n = 19). Principal findings/Conclusions We found that New World populations of P. vivax are as diverse (nucleotide diversity π between 5.2 × 10−4 and 6.2 × 10−4) as P. vivax populations from Southeast Asia, where malaria transmission is substantially more intense. They display several non-synonymous nucleotide substitutions (some of them previously undescribed) in genes known or suspected to be involved in antimalarial drug resistance, such as dhfr, dhps, mdr1, mrp1, and mrp-2, but not in the chloroquine resistance transporter ortholog (crt-o) gene. Moreover, P. vivax in the Americas is much less geographically substructured than local P. falciparum populations, with relatively little between-population genome-wide differentiation (pairwise FST values ranging between 0.025 and 0.092). Finally, P. vivax populations show a rapid decline in linkage disequilibrium with increasing distance between pairs of polymorphic sites, consistent with very frequent outcrossing. We hypothesize that the high diversity of present-day P. vivax lineages in the Americas originated from successive migratory waves and subsequent admixture between

SAM domain-dependent activity of PfTKL3, an essential tyrosine kinase-like kinase of the human malaria parasite Plasmodium falciparum.

Science.gov (United States)

Abdi, Abdirahman; Eschenlauer, Sylvain; Reininger, Luc; Doerig, Christian

2010-10-01

Over the last decade, several protein kinases inhibitors have reached the market for cancer chemotherapy. The kinomes of pathogens represent potentially attractive targets in infectious diseases. The functions of the majority of protein kinases of Plasmodium falciparum, the parasitic protist responsible for the most virulent form of human malaria, remain unknown. Here we present a thorough characterisation of PfTKL3 (PF13_0258), an enzyme that belongs to the tyrosine kinase-like kinase (TKL) group. We demonstrate by reverse genetics that PfTKL3 is essential for asexual parasite proliferation in human erythrocytes. PfTKL3 is expressed in both asexual and gametocytes stages, and in the latter the protein co-localises with cytoskeleton microtubules. Recombinant PfTKL3 displays in vitro autophosphorylation activity and is able to phosphorylate exogenous substrates, and both activities are dramatically dependent on the presence of an N-terminal "sterile alpha-motif" domain. This study identifies PfTKL3 as a validated drug target amenable to high-throughput screening.

Global Mammal Parasite Database version 2.0.

Science.gov (United States)

Stephens, Patrick R; Pappalardo, Paula; Huang, Shan; Byers, James E; Farrell, Maxwell J; Gehman, Alyssa; Ghai, Ria R; Haas, Sarah E; Han, Barbara; Park, Andrew W; Schmidt, John P; Altizer, Sonia; Ezenwa, Vanessa O; Nunn, Charles L

2017-05-01

Illuminating the ecological and evolutionary dynamics of parasites is one of the most pressing issues facing modern science, and is critical for basic science, the global economy, and human health. Extremely important to this effort are data on the disease-causing organisms of wild animal hosts (including viruses, bacteria, protozoa, helminths, arthropods, and fungi). Here we present an updated version of the Global Mammal Parasite Database, a database of the parasites of wild ungulates (artiodactyls and perissodactyls), carnivores, and primates, and make it available for download as complete flat files. The updated database has more than 24,000 entries in the main data file alone, representing data from over 2700 literature sources. We include data on sampling method and sample sizes when reported, as well as both "reported" and "corrected" (i.e., standardized) binomials for each host and parasite species. Also included are current higher taxonomies and data on transmission modes used by the majority of species of parasites in the database. In the associated metadata we describe the methods used to identify sources and extract data from the primary literature, how entries were checked for errors, methods used to georeference entries, and how host and parasite taxonomies were standardized across the database. We also provide definitions of the data fields in each of the four files that users can download. © 2017 by the Ecological Society of America.

Targeting channels and transporters in protozoan parasite infections

Science.gov (United States)

Meier, Anna; Erler, Holger; Beitz, Eric

2018-03-01

Infectious diseases caused by pathogenic protozoa are among the most significant causes of death in humans. Therapeutic options are scarce and massively challenged by the emergence of resistant parasite strains. Many of the current anti-parasite drugs target soluble enzymes, generate unspecific oxidative stress, or act by an unresolved mechanism within the parasite. In recent years, collections of drug-like compounds derived from large-scale phenotypic screenings, such as the malaria or pathogen box, have been made available to researchers free of charge boosting the identification of novel promising targets. Remarkably, several of the compound hits have been found to inhibit membrane proteins at the periphery of the parasites, i.e. channels and transporters for ions and metabolites. In this review, we will focus on the progress made on targeting channels and transporters at different levels and the potential for use against infections with apicomplexan parasites mainly Plasmodium spp. (malaria) and Toxoplasma gondii (toxoplasmosis), with kinetoplastids Trypanosoma brucei (sleeping sickness), Trypanosoma cruzi (Chagas disease) and Leishmania ssp. (leishmaniasis), and the amoeba Entamoeba histolytica (amoebiasis).

Helminth Parasites and the Modulation of Joint Inflammation

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Chelsea E. Matisz

2011-01-01

Full Text Available There is an urgent need to develop better therapeutics for autoimmune and autoinflammatory diseases, of which musculoskeletal disorders such as rheumatoid arthritis are particularly prevalent and debilitating. Helminth parasites are accomplished masters at modifying their hosts' immune activity, and so attention has focused on rodent-helminth model systems to uncover the workings of the mammalian immune response to metazoan parasites, with the hope of revealing molecules and/or mechanisms that can be translated into better treatments for human autoimmune and idiopathic disorders. Substantial proof-of-principal data supporting the concept that infection with helminth parasites can reduce the severity of concomitant disease has been amassed from models of mucosal inflammation. Indeed, infection with helminth parasites has been tried as a therapy in inflammatory bowel disease, and there are case reports relating to other conditions (e.g., autism; however, the impact of infection with parasitic helminths on musculoskeletal diseases has not been extensively studied. Here, we present the view that such a strategy should be applied to the amelioration of joint inflammation and review the literature that supports this contention.

Parasites, ecosystems and sustainability: an ecological and complex systems perspective.

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Horwitz, Pierre; Wilcox, Bruce A

2005-06-01

Host-parasite relationships can be conceptualised either narrowly, where the parasite is metabolically dependent on the host, or more broadly, as suggested by an ecological-evolutionary and complex systems perspective. In this view Host-parasite relationships are part of a larger set of ecological and co-evolutionary interdependencies and a complex adaptive system. These interdependencies affect not just the hosts, vectors, parasites, the immediate agents, but also those indirectly or consequentially affected by the relationship. Host-parasite relationships also can be viewed as systems embedded within larger systems represented by ecological communities and ecosystems. So defined, it can be argued that Host-parasite relationships may often benefit their hosts and contribute significantly to the structuring of ecological communities. The broader, complex adaptive system view also contributes to understanding the phenomenon of disease emergence, the ecological and evolutionary mechanisms involved, and the role of parasitology in research and management of ecosystems in light of the apparently growing problem of emerging infectious diseases in wildlife and humans. An expanded set of principles for integrated parasite management is suggested by this perspective.

Intestinal parasites from fingernails of sidewalk food vendors

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Suriptiastuti

2011-08-01

Full Text Available Intestinal infections with soil-transmitted helminths and protozoa are still prevalent in Indonesia, particularly in urban communities. Transmission of parasitic infections is effected directly or indirectly through objects contaminated with feces, including food, water, fingers and fingernails, indicating the importance of fecal-oral human-to-human transmission. Sidewalk food vendors (SFVs preparing food for their customers are a potential source of infections with many intestinal helminths and protozoa. Compared to other parts of the hand, the area beneath fingernails harbors the most microorganisms and is most difficult to clean. The objective of this cross-sectional study was to determine the prevalence of intestinal parasites in fingernail dirt of SFVs and to identify the associated factors. This study involved 112 SFVs in the vicinity of Hospital X in Central Jakarta, and used microscopic examination of SFV fingernail dirt for determining species prevalence of intestinal parasites. This study showed that 94 samples out of 112 (83.9% were positive for intestinal parasites; 60 samples (63.8% represented single infections and 34 (36.2% mixed infections. Ascaris lumbricoides eggs were found in 30 (26.8% samples and Giardia lamblia cysts in 12 (17.89%. The highest prevalence was found in subjects with primary school education, among whom 20 (30.8% had single infections of A. lumbricoides and 16 (24.6% mixed infections with A. lumbricoides and Trichuris trichiura. In conclusion, prevalence of intestinal parasites in SFV fingernail dirt is extremely high, with the highest prevalence among less educated SFVs. It is recommended to provide health education and training to all SFVs.

Intestinal parasites from fingernails of sidewalk food vendors

Directory of Open Access Journals (Sweden)

Suriptiastuti Suriptiastuti

2016-02-01

Full Text Available Intestinal infections with soil-transmitted helminths and protozoa are still prevalent in Indonesia, particularly in urban communities. Transmission of parasitic infections is effected directly or indirectly through objects contaminated with feces, including food, water, fingers and fingernails, indicating the importance of fecal-oral human-to-human transmission. Sidewalk food vendors (SFVs preparing food for their customers are a potential source of infections with many intestinal helminths and protozoa. Compared to other parts of the hand, the area beneath fingernails harbors the most microorganisms and is most difficult to clean. The objective of this cross-sectional study was to determine the prevalence of intestinal parasites in fingernail dirt of SFVs and to identify the associated factors. This study involved 112 SFVs in the vicinity of Hospital X in Central Jakarta, and used microscopic examination of SFV fingernail dirt for determining species prevalence of intestinal parasites. This study showed that 94 samples out of 112 (83.9% were positive for intestinal parasites; 60 samples (63.8% represented single infections and 34 (36.2% mixed infections. Ascaris lumbricoides eggs were found in 30 (26.8% samples and Giardia lamblia cysts in 12 (17.89%. The highest prevalence was found in subjects with primary school education, among whom 20 (30.8% had single infections of A. lumbricoides and 16 (24.6% mixed infections with A. lumbricoides and Trichuris trichiura. In conclusion, prevalence of intestinal parasites in SFV fingernail dirt is extremely high, with the highest prevalence among less educated SFVs. It is recommended to provide health education and training to all SFVs.

Successful Feeding of Amblyomma coelebs (Acari: Ixodidae) Nymphs on Humans in Brazil: Skin Reactions to Parasitism.

Science.gov (United States)

Garcia, Marcos V; Matias, Jaqueline; Aguirre, AndrÉ De A R; Csordas, Barbara G; SzabÓ, Matias P J; Andreotti, Renato

2015-03-01

Identifying the tick species that successfully feed on humans would increase knowledge of the epidemiology of several tick-borne diseases. These species salivate into the host, increasing the risk of pathogen transmission. However, there is a lack of data in the literature regarding the ticks that prefer to feed on humans. Herein, we describe the successful feeding of Amblyomma coelebs Neumann nymphs on two of the authors after accidental tick bites occurred during field surveys in two preserved areas of Mato Grosso do Sul, Brazil. One of the host-parasite interactions was closely monitored, and the tick development, gross host skin alterations, and related sensations are presented. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America.

A synoptic overview of golden jackal parasites reveals high diversity of species.

Science.gov (United States)

Gherman, Călin Mircea; Mihalca, Andrei Daniel

2017-09-15

The golden jackal (Canis aureus) is a species under significant and fast geographic expansion. Various parasites are known from golden jackals across their geographic range, and certain groups can be spread during their expansion, increasing the risk of cross-infection with other carnivores or even humans. The current list of the golden jackal parasites includes 194 species and was compiled on the basis of an extensive literature search published from historical times until April 2017, and is shown herein in synoptic tables followed by critical comments of the various findings. This large variety of parasites is related to the extensive geographic range, territorial mobility and a very unselective diet. The vast majority of these parasites are shared with domestic dogs or cats. The zoonotic potential is the most important aspect of species reported in the golden jackal, some of them, such as Echinococcus spp., hookworms, Toxocara spp., or Trichinella spp., having a great public health impact. Our review brings overwhelming evidence on the importance of Canis aureus as a wild reservoir of human and animal parasites.

Intestinal Parasites of the Grasscutter

African Journals Online (AJOL)

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excretions of carrier cane rats (Oboegbulem. & Okoronkwo, 1990). The possibility of transmission of parasites of the grasscutter to humans cannot be overlooked. This is more so as some people do not only cherish grasscutter meat but also use the content of the gut both for medicinal purposes and for food (pers. comm.).

Expression of senescent antigen on erythrocytes infected with a knobby variant of the human malaria parasite Plasmodium falciparum

International Nuclear Information System (INIS)

Winograd, E.; Greenan, J.R.T.; Sherman, I.W.

1987-01-01

Erythrocytes infected with a knobby variant of Plasmodium falciparum selectively bind IgG autoantibodies in normal human serum. Quantification of membrane-bound IgG, by use of 125 I-labeled protein A, revealed that erythrocytes infected with the knobby variant bound 30 times more protein A than did noninfected erythrocytes; infection with a knobless variant resulted in less than a 2-fold difference compared with noninfected erythrocytes. IgG binding to knobby erythrocytes appeared to be related to parasite development, since binding of 125 I-labeled protein A to cells bearing young trophozoites (less than 20 hr after parasite invasion) was similar to binding to uninfected erythrocytes. By immunoelectron microscopy, the membrane-bound IgG on erythrocytes infected with the knobby variant was found to be preferentially associated with the protuberances (knobs) of the plasma membrane. The removal of aged or senescent erythrocytes from the peripheral circulation is reported to involve the binding of specific antibodies to an antigen (senescent antigen) related to the major erythrocyte membrane protein band 3. Since affinity-purified autoantibodies against band 3 specifically bound to the plasma membrane of erythrocytes infected with the knobby variant of P. falciparum, it is clear that the malaria parasite induces expression of senescent antigen

A review of wildlife tourism and meta-analysis of parasitism in Africa's national parks and game reserves.

Science.gov (United States)

Odeniran, Paul Olalekan; Ademola, Isaiah Oluwafemi; Jegede, Henry Olanrewaju

2018-06-14

The recent increase of parasitic diseases associated with wildlife tourism can be traced to human contact with wildlife and intense modification of wildlife habitat. The continental estimates of parasitic diseases among visited wildlife-tourists and mammalian wildlife present in conservation areas are lacking; therefore, a general review was necessary to provide insights into Africa's parasitic disease burden and transmission between humans and wildlife. A two-step analysis was conducted with searches in Ovid MEDLINE, EMBASE, PubMed, Web of Science and Global Health. All diseases reported without prevalence were grouped and analysed as categorical data while meta-analysis of prevalence rates of parasitic diseases in wildlife from national parks and reserves in Africa was conducted. Only 4.7% of the tourist centres reported routine wildlife diagnosis for parasitic diseases. Disease intensity shows that cryptosporidiosis and seven other parasitic diseases were observed in both human and wildlife; however, no significant difference in intensity between human and wildlife hosts was observed. Schistosomiasis intensity reports showed a significant increase (P tourism. Pre- and post-travel clinical examinations are important for tourists while routine examination, treatment and rational surveillance are important for these animals to improve wildlife tourism.

A Plasmodium falciparum Strain Expressing GFP throughout the Parasite's Life-Cycle

OpenAIRE

Talman, Arthur M.; Blagborough, Andrew M.; Sinden, Robert E.

2010-01-01

The human malaria parasite Plasmodium falciparum is responsible for the majority of malaria-related deaths. Tools allowing the study of the basic biology of P. falciparum throughout the life cycle are critical to the development of new strategies to target the parasite within both human and mosquito hosts. We here present 3D7HT-GFP, a strain of P. falciparum constitutively expressing the Green Fluorescent Protein (GFP) throughout the life cycle, which has retained its capacity to complete spo...

Targeting protein-protein interactions for parasite control.

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Christina M Taylor

2011-04-01

Full Text Available Finding new drug targets for pathogenic infections would be of great utility for humanity, as there is a large need to develop new drugs to fight infections due to the developing resistance and side effects of current treatments. Current drug targets for pathogen infections involve only a single protein. However, proteins rarely act in isolation, and the majority of biological processes occur via interactions with other proteins, so protein-protein interactions (PPIs offer a realm of unexplored potential drug targets and are thought to be the next-generation of drug targets. Parasitic worms were chosen for this study because they have deleterious effects on human health, livestock, and plants, costing society billions of dollars annually and many sequenced genomes are available. In this study, we present a computational approach that utilizes whole genomes of 6 parasitic and 1 free-living worm species and 2 hosts. The species were placed in orthologous groups, then binned in species-specific orthologous groups. Proteins that are essential and conserved among species that span a phyla are of greatest value, as they provide foundations for developing broad-control strategies. Two PPI databases were used to find PPIs within the species specific bins. PPIs with unique helminth proteins and helminth proteins with unique features relative to the host, such as indels, were prioritized as drug targets. The PPIs were scored based on RNAi phenotype and homology to the PDB (Protein DataBank. EST data for the various life stages, GO annotation, and druggability were also taken into consideration. Several PPIs emerged from this study as potential drug targets. A few interactions were supported by co-localization of expression in M. incognita (plant parasite and B. malayi (H. sapiens parasite, which have extremely different modes of parasitism. As more genomes of pathogens are sequenced and PPI databases expanded, this methodology will become increasingly

Genome sequencing of chimpanzee malaria parasites reveals possible pathways of adaptation to human hosts

KAUST Repository

Otto, Thomas D.; Rayner, Julian C.; Bö hme, Ulrike; Pain, Arnab; Spottiswoode, Natasha; Sanders, Mandy; Quail, Michael; Ollomo, Benjamin; Renaud, Franç ois; Thomas, Alan W.; Prugnolle, Franck; Conway, David J.; Newbold, Chris; Berriman, Matthew

2014-01-01

related chimpanzee parasite species P. reichenowi, and obtaining partial sequence data from a more distantly related chimpanzee parasite (P. gaboni). The close relationship between P. reichenowi and P. falciparum is emphasized by almost complete

Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany.

Science.gov (United States)

Krücken, Jürgen; Blümke, Julia; Maaz, Denny; Demeler, Janina; Ramünke, Sabrina; Antolová, Daniela; Schaper, Roland; von Samson-Himmelstjerna, Georg

2017-01-01

Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health

Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany.

Directory of Open Access Journals (Sweden)

Jürgen Krücken

Full Text Available Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1 and specifically Toxoplasma gondii (repetitive element in brain and ascarids (ITS-2 in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8, Toxocara cati (4 and Parascaris sp. (1 were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa).

Science.gov (United States)

Benamrouz, S; Conseil, V; Creusy, C; Calderon, E; Dei-Cas, E; Certad, G

2012-05-01

The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites) with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer.

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa

Directory of Open Access Journals (Sweden)

Benamrouz S.

2012-05-01

Full Text Available The International Agency for Research on Cancer (IARC identifies ten infectious agents (viruses, bacteria, parasites able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer.

Structure of a two-CAP-domain protein from the human hookworm parasite Necator americanus

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Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu [Pathology and Microbiology Department, 986495 Nebraska Medical Center, Omaha, NE 68198-6495 (United States)

2011-05-01

The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite N. americanus refined to a resolution limit of 2.2 Å is presented. Major proteins secreted by the infective larval stage hookworms upon host entry include Ancylostoma secreted proteins (ASPs), which are characterized by one or two CAP (cysteine-rich secretory protein/antigen 5/pathogenesis related-1) domains. The CAP domain has been reported in diverse phylogenetically unrelated proteins, but has no confirmed function. The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite Necator americanus was refined to a resolution limit of 2.2 Å. The structure was solved by molecular replacement (MR) using Na-ASP-2, a one-CAP-domain ASP, as the search model. The correct MR solution could only be obtained by truncating the polyalanine model of Na-ASP-2 and removing several loops. The structure reveals two CAP domains linked by an extended loop. Overall, the carboxyl-terminal CAP domain is more similar to Na-ASP-2 than to the amino-terminal CAP domain. A large central cavity extends from the amino-terminal CAP domain to the carboxyl-terminal CAP domain, encompassing the putative CAP-binding cavity. The putative CAP-binding cavity is a characteristic cavity in the carboxyl-terminal CAP domain that contains a His and Glu pair. These residues are conserved in all single-CAP-domain proteins, but are absent in the amino-terminal CAP domain. The conserved His residues are oriented such that they appear to be capable of directly coordinating a zinc ion as observed for CAP proteins from reptile venoms. This first structure of a two-CAP-domain ASP can serve as a template for homology modeling of other two-CAP-domain proteins.

Structure of a two-CAP-domain protein from the human hookworm parasite Necator americanus

International Nuclear Information System (INIS)

Asojo, Oluwatoyin A.

2011-01-01

The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite N. americanus refined to a resolution limit of 2.2 Å is presented. Major proteins secreted by the infective larval stage hookworms upon host entry include Ancylostoma secreted proteins (ASPs), which are characterized by one or two CAP (cysteine-rich secretory protein/antigen 5/pathogenesis related-1) domains. The CAP domain has been reported in diverse phylogenetically unrelated proteins, but has no confirmed function. The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite Necator americanus was refined to a resolution limit of 2.2 Å. The structure was solved by molecular replacement (MR) using Na-ASP-2, a one-CAP-domain ASP, as the search model. The correct MR solution could only be obtained by truncating the polyalanine model of Na-ASP-2 and removing several loops. The structure reveals two CAP domains linked by an extended loop. Overall, the carboxyl-terminal CAP domain is more similar to Na-ASP-2 than to the amino-terminal CAP domain. A large central cavity extends from the amino-terminal CAP domain to the carboxyl-terminal CAP domain, encompassing the putative CAP-binding cavity. The putative CAP-binding cavity is a characteristic cavity in the carboxyl-terminal CAP domain that contains a His and Glu pair. These residues are conserved in all single-CAP-domain proteins, but are absent in the amino-terminal CAP domain. The conserved His residues are oriented such that they appear to be capable of directly coordinating a zinc ion as observed for CAP proteins from reptile venoms. This first structure of a two-CAP-domain ASP can serve as a template for homology modeling of other two-CAP-domain proteins

Identification of human intestinal parasites affecting an asymptomatic peri-urban Argentinian population using multi-parallel quantitative real-time polymerase chain reaction.

Science.gov (United States)

Cimino, Rubén O; Jeun, Rebecca; Juarez, Marisa; Cajal, Pamela S; Vargas, Paola; Echazú, Adriana; Bryan, Patricia E; Nasser, Julio; Krolewiecki, Alejandro; Mejia, Rojelio

2015-07-17

In resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. The study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area. qPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1%) and N. americanus (36.4%) infections. There were 48.6% of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/μL: 0.63 fg/μL, P parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.

Issues of the presence of parasitic protozoa in surface waters

Science.gov (United States)

Hawrylik, Eliza

2018-02-01

Parasitic protozoa are very numerous organisms in the environment that play an important role in the spread of water-borne diseases. Water-borne epidemics caused by parasitic protozoa are noted throughout the world. Within these organisms, intestinal protozoa of the genera Cryptosporidium and Giardia are ones of the most serious health hazards for humans. This paper focuses on the problem of the presence of parasitic protozoa in surface waters. Characteristics of the most frequently recognized pathogens responsible for water-borne outbreaks were described, as well as sources of contamination and surface waters contamination due to protozoa of the genus Cryptosporidium and Giardia were presented. The methods of destroying the cysts and oocysts of parasitic protozoa used nowadays in the world were also presented in a review.

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites

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Katarzyna Szwabe

2017-03-01

Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children.

Major parasitic diseases of poverty in mainland China: perspectives for better control.

Science.gov (United States)

Wang, Jin-Lei; Li, Ting-Ting; Huang, Si-Yang; Cong, Wei; Zhu, Xing-Quan

2016-08-01

Significant progress has been made in the prevention, control, and elimination of human parasitic diseases in China in the past 60 years. However, parasitic diseases of poverty remain major causes of morbidity and mortality, and inflict enormous economic costs on societies.In this article, we review the prevalence rates, geographical distributions, epidemic characteristics, risk factors, and clinical manifestations of parasitic diseases of poverty listed in the first issue of the journal Infectious Diseases of Poverty on 25 October 2012. We also address the challenges facing control of parasitic diseases of poverty and provide suggestions for better control.

Tropical veterinary parasites at Harvard University's Museum of Comparative Zoology.

Science.gov (United States)

Conn, David Bruce

2008-12-01

Tropical veterinary parasites have been maintained by the Museum of Comparative Zoology (MCZ) at Harvard University since the mid 1800s. Most of these are maintained by the Department of Invertebrate Zoology, but many vectors and intermediate hosts are maintained by the Departments of Entomology and Malacology. The largest collections are of avian and mammalian ticks (Acarina) that are important as both parasites and vectors. Nematodes are second in numbers, followed by cestodes, trematodes, and several minor helminth groups, crustacean parasites of fish, and protozoan parasites of various hosts. The MCZ directed or participated in several major expeditions to tropical areas around the globe in the early 1900s. Many of these expeditions focused on human parasites, but hundreds of veterinary and zoonotic parasites were also collected from these and numerous, smaller, tropical expeditions. Host sources include companion animals, livestock, laboratory species, domestic fowl, reptiles, amphibians, exotics/zoo animals, commercially important fishes, and other wildlife. Specimens are curated, either fixed whole in vials or mounted on slides as whole mounts or histopathological sections. The primary emphasis of MCZ's current work with tropical veterinary parasites is on voucher specimens from epidemiological, experimental, and clinical research.

Caspase dependent programmed cell death in developing embryos: a potential target for therapeutic intervention against pathogenic nematodes.

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Alok Das Mohapatra

2011-09-01

Full Text Available BACKGROUND: Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites. METHODOLOGY/PRINCIPAL FINDINGS: For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths. CONCLUSIONS/SIGNIFICANCE: Our observations have revealed for the first time, that induction of apoptosis in

Plasmodial Hsp70s are functionally adapted to the malaria parasite life cycle

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Jude M Przyborski

2015-06-01

Full Text Available The human malaria parasite, Plasmodium falciparum, encodes a minimal complement of six heat shock protein 70s (PfHSP70s, some of which are highly expressed and are thought to play an important role in the survival and pathology of the parasite. In addition to canonical features of molecular chaperones, these HSP70s possess properties that reflect functional adaptation to a parasitic life style, including resistance to thermal insult during fever periods and host-parasite interactions. The parasite even exports an HSP70 to the host cell where it is likely to be involved in host cell modification. This review focuses on the features of the PfHSP70s, particularly with respect to their adaptation to the malaria parasite life cycle.

An essential malaria protein defines the architecture of blood-stage and transmission-stage parasites.

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Absalon, Sabrina; Robbins, Jonathan A; Dvorin, Jeffrey D

2016-04-28

Blood-stage replication of the human malaria parasite Plasmodium falciparum occurs via schizogony, wherein daughter parasites are formed by a specialized cytokinesis known as segmentation. Here we identify a parasite protein, which we name P. falciparum Merozoite Organizing Protein (PfMOP), as essential for cytokinesis of blood-stage parasites. We show that, following PfMOP knockdown, parasites undergo incomplete segmentation resulting in a residual agglomerate of partially divided cells. While organelles develop normally, the structural scaffold of daughter parasites, the inner membrane complex (IMC), fails to form in this agglomerate causing flawed segmentation. In PfMOP-deficient gametocytes, the IMC formation defect causes maturation arrest with aberrant morphology and death. Our results provide insight into the mechanisms of replication and maturation of malaria parasites.

Parasites

Centers for Disease Control (CDC) Podcasts

2010-05-06

In this podcast, a listener wants to know what to do if he thinks he has a parasite or parasitic disease.  Created: 5/6/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/6/2010.

Differential antibody isotype reactivity to specific antigens in human lymphatic filariasis: gp15/400 preferentially induces immunoglobulin E (IgE), IgG4, and IgG2

NARCIS (Netherlands)

Yazdanbakhsh, M.; Paxton, W. A.; Brandenburg, A.; van Ree, R.; Lens, M.; Partono, F.; Maizels, R. M.; Selkirk, M. E.

1995-01-01

Lymphatic filarial infection in humans is associated with a strong skewing of the immune response towards the TH2 arm, with prominent interleukin 4-producing cells and elevated levels of immunoglobulin G4 (IgG4) and IgE antibodies in peripheral blood. To determine how such a generalized TH2

Methodology and application of flow cytometry for investigation of human malaria parasites.

Science.gov (United States)

Grimberg, Brian T

2011-03-31

Historically, examinations of the inhibition of malaria parasite growth/invasion, whether using drugs or antibodies, have relied on the use of microscopy or radioactive hypoxanthine uptake. These are considered gold standards for measuring the effectiveness of antimalarial treatments, however, these methods have well known shortcomings. With the advent of flow cytometry coupled with the use of fluorescent DNA stains allowed for increased speed, reproducibility, and qualitative estimates of the effectiveness of antibodies and drugs to limit malaria parasite growth which addresses the challenges of traditional techniques. Because materials and machines available to research facilities are so varied, different methods have been developed to investigate malaria parasites by flow cytometry. This review is intended to serve as a reference guide for advanced users and importantly, as a primer for new users, to support expanded use and improvements to malaria flow cytometry, particularly in endemic countries. Copyright © 2011 Elsevier B.V. All rights reserved.

Expression of cancer-associated simple mucin-type O-glycosylated antigens in parasites.

Science.gov (United States)

Osinaga, Eduardo

2007-01-01

Simple mucin-type O-glycan structures, such as Tn, TF, sialyl-Tn and Tk antigens, are among of the most specific human cancer-associated structures. These antigens are involved in several types of receptor-ligand interactions, and they are potential targets for immunotherapy. In the last few years several simple mucin-type O-glycan antigens were identified in different species belonging to the main two helminth parasite phyla, and sialyl-Tn bearing glycoproteins were detected in Trypanosoma cruzi. These results are of interest to understand new aspects in parasite glycoimmunology and may help identify new biological characteristics of parasites as well of the host-parasite relationship. Considering that different groups reported a negative correlation between certain parasite infections and cancer development, we could hypothesize that simple mucin-type O-glycosylated antigens obtained from parasites could be good potential targets for cancer immunotherapy.

Enlightening the malaria parasite life cycle: bioluminescent Plasmodium in fundamental and applied research

OpenAIRE

Siciliano, Giulia; Alano, Pietro

2015-01-01

The unicellular protozoan parasites of the genus Plasmodium impose on human health worldwide the enormous burden of malaria. The possibility to genetically modify several species of malaria parasites represented a major advance in the possibility to elucidate their biology and is now turning laboratory lines of transgenic Plasmodium into precious weapons to fight malaria. Amongst the various genetically modified plasmodia, transgenic parasite lines expressing bioluminescent reporters have bee...

[Antagonistic interactions between saprotrophic fungi and geohelminths. 2. Saprotrophic fungi in biocontrol of parasitic geohelminths of humans and animals].

Science.gov (United States)

Jaborowska-Jarmoluk, Magdalena; Mazurkiewicz-Zapałowicz, Kinga; Kołodziejczyk, Lidia

2009-01-01

The soils ecosystem plays an important role in the epidemiology of geohelminth diseases of humans and animals. Soil contamination with ova of the parasitic geohelminths represents a global public health-hazard issue. Biological agents have been thought to control the infective forms of parasites present in the soil. Biocontrol of geohelminths represents an alternative to pesticides (i.e., nematicides), which are not efficient in killing infective nematode forms and, additionally, result in the environment pollution and long-term disturbances in the soil ecosystem homeostasis. The degree of the inhibiting effect of soil saprotrophic fungi on geohelminth embryonic development varies and depends on the species. A number of fungi cause various morphological disorders in the embryos of developing parasitic nematodes, but also have an ovicidal effect. Although the nature of the antagonism between fungi and other living organisms has not been fully explained, it is certain that mycotoxins and fungal enzymes constitute its important components. Considering the studies carried out so far, the antagonistic effect of mold fungi against the infective stages of geohelminths can be fully recommended as a real control factor, especially as these saprotrophs represent a natural factor within the soil environment, that is of particular biochemical activity.

Human intestinal parasites in crusader Acre: Evidence for migration with disease in the medieval period.

Science.gov (United States)

Mitchell, Piers D; Anastasiou, Evilena; Syon, Danny

2011-12-01

The aim of this research is to highlight the role of ancient parasites as evidence for human migration in past populations. The material analysed was soil sediment from the excavation of a medieval cesspool in the city of Acre, in Israel. Archaeological stratigraphy and radiocarbon dating of a fragment of animal bone from the cesspool confirm its use in the 13th century CE, during the crusader period. At that time Acre was located in the Frankish Kingdom of Jerusalem. Soil samples from the cesspool were analysed and eggs of the roundworm (Ascaris lumbricoides) and fish tapeworm (Diphyllobothrium latum) were identified. The fish tapeworm has only been found in the mainland Near East once before, in a latrine of the crusader Order of St. John (Knights Hospitaller). It has been absent in all earlier cesspools, latrines and coprolites so far studied in the region. In contrast to its rarity in the Levant, the fish tapeworm was common in northern Europe during the medieval period. The presence of fish tapeworm eggs in a crusader period cesspool in Acre suggests its use by crusaders or pilgrims from northern Europe who travelled to the Levant carrying these parasites in their intestines. Copyright © 2011 Elsevier Inc. All rights reserved.

Parasitic helminths: a pharmacopeia of anti-inflammatory molecules.

Science.gov (United States)

Johnston, M J G; MacDonald, J A; McKay, D M

2009-02-01

Infection with parasitic helminths takes a heavy toll on the health and well-being of humans and their domestic livestock, concomitantly resulting in major economic losses. Analyses have consistently revealed bioactive molecules in extracts of helminths or in their excretory/secretory products that modulate the immune response of the host. It is our view that parasitic helminths are an untapped source of immunomodulatory substances that, in pure form, could become new drugs (or models for drug design) to treat disease. Here, we illustrate the range of immunomodulatory molecules in selected parasitic trematodes, cestodes and nematodes, their impact on the immune cells in the host and how the host may recognize these molecules. There are many examples of the partial characterization of helminth-derived immunomodulatory molecules, but these have not yet translated into new drugs, reflecting the difficulty of isolating and fully characterizing proteins, glycoproteins and lipid-based molecules from small amounts of parasite material. However, this should not deter the investigator, since analytical techniques are now being used to accrue considerable structural information on parasite-derived molecules, even when only minute quantities of tissue are available. With the introduction of methodologies to purify and structurally-characterize molecules from small amounts of tissue and the application of high throughput immunological assays, one would predict that an assessment of parasitic helminths will yield a variety of novel drug candidates in the coming years.

Introduced cryptic species of parasites exhibit different invasion pathways.

Science.gov (United States)

Miura, Osamu; Torchin, Mark E; Kuris, Armand M; Hechinger, Ryan F; Chiba, Satoshi

2006-12-26

Sometimes infectious agents invade and become established in new geographic regions. Others may be introduced yet never become established because of the absence of suitable hosts in the new region. This phenomenon may be particularly true for the many parasites with complex life cycles, where various life stages require different host species. Homogenization of the world's biota through human-mediated invasions may reunite hosts and parasites, resulting in disease outbreaks in novel regions. Here we use molecular genetics to differentiate invasion pathways for two digenean trematode parasites and their exotic host, the Asian mud snail, Batillaria attramentaria. All of the snail haplotypes found in introduced populations in North America were identical to haplotypes common in the areas of Japan that provided oysters for cultivation in North America, supporting the hypothesis that the snails were introduced from Japan with seed oysters. Two cryptic trematode species were introduced to North American populations in high frequencies. We found a marked reduction of genetic variation in one of these species, suggesting it experienced a bottleneck or founder event comparable to that of the host snail. In contrast, no genetic variation was lost in the other parasite species. We hypothesize that this parasite was and is dispersed naturally by migratory shorebirds and was able to establish only after the host snail, B. attramentaria, was introduced to North America. Evaluation of the nature of invasion pathways and postinvasion consequences will aid mitigation of spreading diseases of humans, livestock, and wildlife in an increasingly globalized world.

Gastrointestinal helminth parasites of pet and stray dogs as a potential risk for human health in Bahir Dar town, north-western Ethiopia

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Tadiwos Abere

Full Text Available Aim: A cross-sectional study was carried out from November 2011 to April 2012 to determine the prevalence and species of gastrointestinal (GI helminth parasites in pet and stray dogs as a potential risk for human health in Bahir Dar town, northwestern Ethiopia. Materials and Methods: A total of 384 and 46 faecal samples were collected from pet and stray dogs, respectively and xamined by using standard coprologic techniques. Results: The overall prevalence of GI helminth infection in pet and stray dogs was 75.26 and 84.78%, respectively. The detected parasites with their frequencies in pet dogs were Ancylostoma caninum (78.89%, Toxocara canis (39.79%, Dipylidium caninum (29.75%, Strongyloides stercoralis (29.06%, Taeniidae (23.87% and Trichuris vulpis (7.95%. Stray dogs were found more likely to be polyparasitized and presented higher prevalence of A. caninum, T. canis, S. stercoralis, Trichuris vulpis and Taeniidae (P < 0.05 than domiciled ones. Diphyllobothrium latum was detected only in 10.25% of stray dogs. Toxocara canis and A. caninum (P < 0.05 were detected more frequently in dogs with less than 6 months of age (P <0.05 than old age dogs. The sex or breed groups didn't significantly affect the prevalence of parasites. A significant variation was recorded (P < 0.05 between different feeding systems where higher prevalence was observed in uncontrolled feeding group (82.18% compared to controlled feeding (32.08%. Conclusion: Different gastrointestinal parasites in pet and stray dogs were identified in the study area that can potentially infect humans and cause serious public-health problems. Thus, concerted efforts should therefore be made to educate dog owners to embrace modern dog disease control programs and measures have to be taken on stray dogs. [Vet World 2013; 6(7.000: 388-392

PARASITIC CONTAMINATION OF WELLS DRINKING WATER IN MAZANDARAN PROVINCE

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Z. Yousefi ، H. Ziaei hezarjaribi ، A. A. Enayati ، R. A. Mohammadpoor

2009-10-01

Full Text Available There is a direct relation between the prevalence of some parasitic diseases and the presence of those etiologic agents in water. The purpose of this research was to determine the contamination rate of wells drinking water to parasites in Mazandaran province in the north of Iran. 989 water samples were randomly taken based on the population of towns and number of health centers from 12 cities of Mazandaran province and transferred to the laboratory in sterile containers. Water samples were then filtered and analyzed according to the World Health Organization guidelines. Direct method and Gram staining procedure were used to identify the parasites. If cryptosporidium was seen, floatation (sheather’s sugar and modified Ziehl-Neelsen staining method were performed. Parasites count was undertaken using McMaster counting slide (0.3 mL. 197 out of 989 water samples were contaminated with different parasites. From 197 contaminated samples, 20 different types of parasites were separated of which 53 (26.9% were pathogenic, 100 (50.8% non pathogenic, and 44 non-infective stages of parasites. Distance between wells and sources of contamination, type of water distribution systems, city and chlorination status had significantly statistical relationship with contamination prevalence (p<0.001. According to the results and considering the direct correlation between safe water and human health, proper implementation of providing hygienic drinking water should be enforced.

Application of molecular methods for monitoring transmission stages of malaria parasites

International Nuclear Information System (INIS)

Babiker, Hamza A; Schneider, Petra

2008-01-01

Recent technical advances in malaria research have allowed specific detection of mRNA of genes that are expressed exclusively in sexual stages (gametocytes) of malaria parasites. The specificity and sensitivity of these techniques were validated on cultured laboratory clones of both human malaria parasites (Plasmodium falciparum) and rodent parasites (P. chabaudi). More recently, quantitative molecular techniques have been developed to quantify these sexual stages and used to monitor gametocyte dynamics and their transmission to mosquitoes. Molecular techniques showed that the infectious reservoir for malaria is larger than expected from previous microscopic studies; individual parasite genotypes within an infection can simultaneously produce infectious gametocytes; gametocyte production can be sustained for several months, and is modulated by environmental factors. The above techniques have empowered approaches for in-depth analysis of the biology of the transmission stages of the parasite and epidemiology of malaria transmission

A survey for potentially zoonotic gastrointestinal parasites of dogs and pigs in Cambodia

DEFF Research Database (Denmark)

Inpankaew, Tawin; Murrell, Kenneth Darwin; Pinyopanuwat, Nongnuch

2015-01-01

There is little information available on parasites of zoonotic significance in Cambodia. In 2011, in an effort to obtain data on potentially zoonotic gastrointestinal parasites in domestic animals, 50 dogs and 30 pigs residing in 38 households located in Ang Svay Check village, Takeo province, Ca....... Follow-up studies are required to further taxonomically characterize these dog and pig parasites and to determine their role in human parasites in this community.......There is little information available on parasites of zoonotic significance in Cambodia. In 2011, in an effort to obtain data on potentially zoonotic gastrointestinal parasites in domestic animals, 50 dogs and 30 pigs residing in 38 households located in Ang Svay Check village, Takeo province......, Cambodia were examined for parasites from faecal samples. The samples were processed using the formalin-ethyl acetate concentration technique (FECT). Hookworms were the most common zoonotic parasite found in dogs (80.0%) followed by Echinostomes (18.0%). While, in pigs, Fasciolopsis buski was the most...

Homologous Recombination in Protozoan Parasites and Recombinase Inhibitors

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Andrew A. Kelso

2017-09-01

Full Text Available Homologous recombination (HR is a DNA double-strand break (DSB repair pathway that utilizes a homologous template to fully repair the damaged DNA. HR is critical to maintain genome stability and to ensure genetic diversity during meiosis. A specialized class of enzymes known as recombinases facilitate the exchange of genetic information between sister chromatids or homologous chromosomes with the help of numerous protein accessory factors. The majority of the HR machinery is highly conserved among eukaryotes. In many protozoan parasites, HR is an essential DSB repair pathway that allows these organisms to adapt to environmental conditions and evade host immune systems through genetic recombination. Therefore, small molecule inhibitors, capable of disrupting HR in protozoan parasites, represent potential therapeutic options. A number of small molecule inhibitors were identified that disrupt the activities of the human recombinase RAD51. Recent studies have examined the effect of two of these molecules on the Entamoeba recombinases. Here, we discuss the current understandings of HR in the protozoan parasites Trypanosoma, Leishmania, Plasmodium, and Entamoeba, and we review the small molecule inhibitors known to disrupt human RAD51 activity.

The past, present and future of fluorescent protein tags in anaerobic protozoan parasites.

Science.gov (United States)

Morin-Adeline, Victoria; Šlapeta, Jan

2016-03-01

The world health organization currently recognizes diarrhoeal diseases as a significant cause of death in children globally. Protozoan parasites such as Giardia and Entamoeba that thrive in the oxygen-deprived environment of the human gut are common etiological agents of diarrhoea. In the urogenital tract of humans, the anaerobic protozoan parasite Trichomonas vaginalis is notorious as the most common non-viral, sexually transmitted pathogen. Even with high medical impact, our understanding of anaerobic parasite physiology is scarce and as a result, treatment choices are limited. Fluorescent proteins (FPs) are invaluable tools as genetically encoded protein tags for advancing knowledge of cellular function. These FP tags emit fluorescent colours and once attached to a protein of interest, allow tracking of parasite proteins in the dynamic cellular space. Application of green FPs-like FPs in anaerobic protozoans is hindered by their oxygen dependency. In this review, we examine aspects of anaerobic parasite biology that clash with physio-chemical properties of FPs and limit their use as live-parasite protein tags. We expose novel FPs, such as miniSOG that do not require oxygen for signal production. The potential use of novel FPs has the opportunity to leverage the anaerobe parasitologist toolkit to that of aerobe parasitologist.

Strongyloides Stercoralis: The Most Prevalent Parasitic Cause of Eosinophilia in Gilan Province, Northern Iran

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B Rahmati

2010-09-01

Full Text Available Background: Eosinophilia occurs in a wide variety of situations such as parasitic infections, aller­gic disorders, and malignancies. Most cases of eosinophilia of parasitic origin, especially those with a tissue migration life cycles consists of human infections by helminth parasites. The aim of present study was to determine the parasitic causes of eosinophilia in patients in a major endemic area of human fascioliasis in Gilan Province, northern part of Iran.Methods: One hundred and fifty patients presenting with an elevated eosinophilia attending infec­tious disease clinics with or without clinical symptoms, were examined. After clinical his­tory evaluation and physical examination, coprological examinations were performed using the formalin-ether and the Kato-Katz techniques for detection of Fasciola sp. and intestinal parasites.Results: Forty two percent of patients were infected with S. stercoralis, nine (6% were found to be infected with Fasciola sp. while only a single patient (0.7% were infected by Ttrichostrongy­lus sp.Conclusion: Local clinicians in Gilan may consider eosinophilia as a suggestive indication for diagnosis of human fascioliasis, especially when microscopic stool and/or serological tests are negative. Based on the results, local physicians should consider S. stercoralis as the potential causes of eosinophilia in patients with elevated eosinophilia.

Comparative genomics of the Apicomplexan parasites Toxoplasma gondii and Neospora caninum 

DEFF Research Database (Denmark)

Reid, Adam James; Vermont, Sarah J.; Cotton, James A.

2012-01-01

Coccidian parasites have a major impact on human and animal health world-wide and are among the most successful and widespread parasitic protozoa. They include Neospora caninum which is a leading cause of abortion in cattle and one of its nearest relatives, Toxoplasma gondii. Despite its close...... almost exclusively on molecules which control the interaction of the parasite with the host cell. We show that some secreted invasion-related proteins and surface genes which are known to control virulence and host cell interactions in Toxoplasma are dramatically altered in their expression...... and functionality in Neospora and propose that evolution of these genes may underpin the ecological niches inhabited by coccidian parasites....

Venom allergen-like proteins in secretions of plant-parasitic nematodes activate and suppress extracellular plant immune receptors

NARCIS (Netherlands)

Lozano Torres, J.L.

2014-01-01

Parasitic worms threaten human, animal and plant health by infecting people, livestock and crops worldwide. Animals and plants share an anciently evolved innate immune system. Parasites modulate this immune system by secreting proteins to maintain their parasitic lifestyle. This thesis

Zoonotic intestinal parasites of carnivores: A systematic review in Iran

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Shahabeddin Sarvi

2018-01-01

Full Text Available Aim: Parasitic infections, especially of the zoonotic-parasitic type, are the most important health, economic, and social problems in developing countries, including Iran. The aim of this study was to review systematically the available data on gastrointestinal parasites of carnivores in Iran and their ability to infect humans. Materials and Methods: Studies reporting intestinal parasites of carnivores were systematically collected from nine electronic English and Persian databases and Proceedings of Iranian parasitology and veterinary congresses published between 1997 and 2015. A total of 26 studies issued from 1997 to 2015 met the eligibility criteria. Results: The pooled proportion of intestinal parasites of carnivores was estimated as 80.4% (95% confidence interval=70.2-88.8%. The overall prevalence of gastrointestinal parasites in dogs, cats, foxes, and jackals were 57.89%, 90.62%, 89.17%, and 97.32%, respectively. Dipylidium caninum (20.45%, Toxocara spp. (18.81%, Taenia hydatigena (15.28%, Mesocestoides lineatus (11.83%, Echinococcus granulosus (10%, and Toxascaris leonina (8.69% were the most frequently observed parasites. Conclusion: High prevalence rates of zoonotic intestinal parasites of carnivores particularly Echinococcus spp. and Toxocara spp. increase the risk of acquiring zoonotic infections such as cystic hydatid, alveolar cysts, and visceral or ocular larva migrants in Iranian people. Therefore, it is essential for public health centers to develop more effective control strategies to decrease infections rates in carnivores' populations.

Zoonotic intestinal parasites of carnivores: A systematic review in Iran

Science.gov (United States)

Sarvi, Shahabeddin; Daryani, Ahmad; Sharif, Mehdi; Rahimi, Mohammad Taghi; Kohansal, Mohammad Hasan; Mirshafiee, Siavash; Siyadatpanah, Abolghasem; Hosseini, Seyed-Abdollah; Gholami, Shirzad

2018-01-01

Aim: Parasitic infections, especially of the zoonotic-parasitic type, are the most important health, economic, and social problems in developing countries, including Iran. The aim of this study was to review systematically the available data on gastrointestinal parasites of carnivores in Iran and their ability to infect humans. Materials and Methods: Studies reporting intestinal parasites of carnivores were systematically collected from nine electronic English and Persian databases and Proceedings of Iranian parasitology and veterinary congresses published between 1997 and 2015. A total of 26 studies issued from 1997 to 2015 met the eligibility criteria. Results: The pooled proportion of intestinal parasites of carnivores was estimated as 80.4% (95% confidence interval=70.2-88.8%). The overall prevalence of gastrointestinal parasites in dogs, cats, foxes, and jackals were 57.89%, 90.62%, 89.17%, and 97.32%, respectively. Dipylidium caninum (20.45%), Toxocara spp. (18.81%), Taenia hydatigena (15.28%), Mesocestoides lineatus (11.83%), Echinococcus granulosus (10%), and Toxascaris leonina (8.69%) were the most frequently observed parasites. Conclusion: High prevalence rates of zoonotic intestinal parasites of carnivores particularly Echinococcus spp. and Toxocara spp. increase the risk of acquiring zoonotic infections such as cystic hydatid, alveolar cysts, and visceral or ocular larva migrants in Iranian people. Therefore, it is essential for public health centers to develop more effective control strategies to decrease infections rates in carnivores’ populations. PMID:29479158

Characterizing Ancylostoma caninum transcriptome and exploring nematode parasitic adaptation

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Hawdon John

2010-05-01

Full Text Available Abstract Background Hookworm infection is one of the most important neglected diseases in developing countries, with approximately 1 billion people infected worldwide. To better understand hookworm biology and nematode parasitism, the present study generated a near complete transcriptome of the canine hookworm Ancylostoma caninum to a very high coverage using high throughput technology, and compared it to those of the free-living nematode Caenorhabditis elegans and the parasite Brugia malayi. Results The generated transcripts from four developmental stages, infective L3, serum stimulated L3, adult male and adult female, covered 93% of the A. caninum transcriptome. The broad diversity among nematode transcriptomes was confirmed, and an impact of parasitic adaptation on transcriptome diversity was inferred. Intra-population analysis showed that A. caninum has higher coding sequence diversity than humans. Examining the developmental expression profiles of A. caninum revealed major transitions in gene expression from larval stages to adult. Adult males expressed the highest number of selectively expressed genes, but adult female expressed the highest number of selective parasitism-related genes. Genes related to parasitism adaptation and A. caninum specific genes exhibited more expression selectivity while those conserved in nematodes tend to be consistently expressed. Parasitism related genes were expressed more selectively in adult male and female worms. The comprehensive analysis of digital expression profiles along with transcriptome comparisons enabled identification of a set of parasitism genes encoding secretory proteins in animal parasitic nematode. Conclusions This study validated the usage of deep sequencing for gene expression profiling. Parasitic adaptation of the canine hookworm is related to its diversity and developmental dynamics. This comprehensive comparative genomic and expression study substantially improves our understanding of

Parasite-altered feeding behavior in insects: integrating functional and mechanistic research frontiers.

Science.gov (United States)

Bernardo, Melissa A; Singer, Michael S

2017-08-15

Research on parasite-altered feeding behavior in insects is contributing to an emerging literature that considers possible adaptive consequences of altered feeding behavior for the host or the parasite. Several recent ecoimmunological studies show that insects can adaptively alter their foraging behavior in response to parasitism. Another body of recent work shows that infection by parasites can change the behavior of insect hosts to benefit the parasite; manipulations of host feeding behavior may be part of this phenomenon. Here, we address both the functional and the underlying physiological frontiers of parasite-altered feeding behavior in order to spur research that better integrates the two. Functional categories of parasite-altered behavior that are adaptive for the host include prophylaxis, therapy and compensation, while host manipulation is adaptive for the parasite. To better understand and distinguish prophylaxis, therapy and compensation, further study of physiological feedbacks affecting host sensory systems is especially needed. For host manipulation in particular, research on mechanisms by which parasites control host feedbacks will be important to integrate with functional approaches. We see this integration as critical to advancing the field of parasite-altered feeding behavior, which may be common in insects and consequential for human and environmental health. © 2017. Published by The Company of Biologists Ltd.

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

Science.gov (United States)

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.

Zoonotic enteric parasites transmitted from dogs in Egypt with special concern to Toxocara canis infection

Science.gov (United States)

Awadallah, Maysa A. I.; Salem, Lobna M. A.

2015-01-01

Aim: This work aimed to study the role played by dogs in transmitting zoonotic enteric parasites to humans in Egypt and to analyze the risk factors associated with the occurrence of such infection in dogs. Serodiagnosis of anti-Toxocara immunoglobulin G (IgG) antibodies among human beings as well as analyzing risk factors predispose to Toxocara canis infection in human beings are another objectives of this study. Materials and Methods: From June to December 2013, a total of 130 fecal samples from 4 dog populations (Military, nomadic and domiciled dogs from rural and high standard districts) and 150 stool samples of 6 occupational groups were examined for the presence of enteric parasitic infection. Moreover, 150 serum samples were collected from humans from whom stool samples were collected and examined for the presence of anti-T. canis antibodies. Results: Enteric parasites were detected in 30% of fecal samples from 4 dog populations in Egypt. High infectivity had been reported in nomadic dogs (63.33%) (Crude odds ratios [COR]=67.36, 95% confidence interval [CI]=8.09-560.8, p0.05) did not seem to have a significant association among the examined dogs. Enteric parasitic infection was reported in 31/150 human stools (20.67%). Students were the most affected groups (37.14%), followed by nomadic people (24%), house wives (20%), house guarders and military workers (12%, each), and employees (10%). The identified parasites were Cryptosporidium spp. (9.33%), Ascaris lumbercoides (3.33%), Heterophyes spp. and Ancylostoma spp. (2.66%, each) and Paragonimus spp. and Hymenolepis nana (1.33%, each). Toxocara IgG antibodies were detected in 36/150 (24%) serum samples investigated. Toxocara IgG antibodies were more prevalent in males (26.66%) than females (20%). Seroprevalence was highest (17/35, 48.57%) in 7-15 years old (COR=6.93, 95% CI=1.75-27.43, p=0.006). Seroprevalence values for T. canis antibodies were higher in those; raising dogs (29.85%), eating raw vegetables (25

Plant hormone cytokinins control cell cycle progression and plastid replication in apicomplexan parasites.

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Andrabi, Syed Bilal Ahmad; Tahara, Michiru; Matsubara, Ryuma; Toyama, Tomoko; Aonuma, Hiroka; Sakakibara, Hitoshi; Suematsu, Makoto; Tanabe, Kazuyuki; Nozaki, Tomoyoshi; Nagamune, Kisaburo

2018-02-01

Cytokinins are plant hormones that are involved in regulation of cell proliferation, cell cycle progression, and cell and plastid development. Here, we show that the apicomplexan parasites Toxoplasma gondii and Plasmodium berghei, an opportunistic human pathogen and a rodent malaria agent, respectively, produce cytokinins via a biosynthetic pathway similar to that in plants. Cytokinins regulate the growth and cell cycle progression of T. gondii by mediating expression of the cyclin gene TgCYC4. A natural form of cytokinin, trans-zeatin (t-zeatin), upregulated expression of this cyclin, while a synthetic cytokinin, thidiazuron, downregulated its expression. Immunofluorescence microscopy and quantitative PCR analysis showed that t-zeatin increased the genome-copy number of apicoplast, which are non-photosynthetic plastid, in the parasite, while thidiazuron led to their disappearance. Thidiazuron inhibited growth of T. gondii and Plasmodium falciparum, a human malaria parasite, suggesting that thidiazuron has therapeutic potential as an inhibitor of apicomplexan parasites. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Does Magnetic Field Affect Malaria Parasite Replication in Human Red Blood Cells?

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Chanturiya, Alexandr N.; Glushakova, Svetlana; Yin, Dan; Zimmerberg, Joshua

2004-01-01

Digestion of red blood cell (RBC) hemoglobin by the malaria parasite results in the formation of paramagnetic hemazoin crystals inside the parasite body. A number of reports suggest that magnetic field interaction with hamazoin crystals significantly reduces the number of infected cells in culture, and thus magnetic field can be used to combat malaria. We studies the effects of magnetic filed on the Plasmodium falciparum asexual life cycle inside RBCs under various experimental conditions. No effect was found during prolonged exposure of infected RBCs to constant magnetic fields up to 6000 Gauss. Infected RBCs were also exposed, under temperature-controlled conditions, to oscillating magnetic fields with frequencies in the range of 500-20000 kHz, and field strength 30-600 Gauss. This exposure often changed the proportion of different parasite stages in treated culture compared to controls. However, no significant effect on parasitemia was observed in treated cultures. This result indicates that the magnetic field effect on Plasmodium falciparum is negligible, or that hypothetical negative and positive effects on different stages within one 48-hour compensate each other.

Stage- and gender-specific proteomic analysis of Brugia malayi excretory-secretory products.

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Yovany Moreno

Full Text Available INTRODUCTION: While we lack a complete understanding of the molecular mechanisms by which parasites establish and achieve protection from host immune responses, it is accepted that many of these processes are mediated by products, primarily proteins, released from the parasite. Parasitic nematodes occur in different life stages and anatomical compartments within the host. Little is known about the composition and variability of products released at different developmental stages and their contribution to parasite survival and progression of the infection. METHODOLOGY/PRINCIPAL FINDINGS: To gain a deeper understanding on these aspects, we collected and analyzed through 1D-SDS PAGE and LC-MS/MS the Excretory-Secretory Products (ESP of adult female, adult male and microfilariae of the filarial nematode Brugia malayi, one of the etiological agents of human lymphatic filariasis. This proteomic analysis led to the identification of 228 proteins. The list includes 76 proteins with unknown function as well as also proteins with potential immunoregulatory properties, such as protease inhibitors, cytokine homologues and carbohydrate-binding proteins. Larval and adult ESP differed in composition. Only 32 proteins were shared between all three stages/genders. Consistent with this observation, different gene ontology profiles were associated with the different ESP. CONCLUSIONS/SIGNIFICANCE: A comparative analysis of the proteins released in vitro by different forms of a parasitic nematode dwelling in the same host is presented. The catalog of secreted proteins reflects different stage- and gender-specific related processes and different strategies of immune evasion, providing valuable insights on the contribution of each form of the parasite for establishing the host-parasite interaction.

Use of irradiation to control infectivity of food-borne parasites

International Nuclear Information System (INIS)

1993-01-01

Food-borne parasitic diseases are common throughout the world, pose significant health problems and cause economic losses in terms of agricultural commodities and human productivity. The diseases usually occur through consumption of raw or partially cooked foods with are infected by various parasites (e.g. tapeworms, roundworms, flukes, parasitic protozoa, etc.). The problem is significant in developing countries where the population has the habit of consuming raw food of animal origin. Available data, with the exception of data on Trichinella spiralis, a parasitic nematode, were insufficient for the use of irradiation technology to control food-borne parasites. Therefore, a Co-ordinated Research Programme (CRP) on the Use of Irradiation to Control Infectivity of Food-Borne Parasites was implemented by the FAO/IAEA in 1986. The results of the work carried out over five years (1986-1991) by twelve researchers participating in the programme, have established conclusively the potential for application of food irradiation in the control of liver flukes, tapeworms, roundworms, trichinosis, toxoplasmosis, etc. This report includes the conclusions and recommendations of the participants concerning the results obtained and need for further research. Refs, figs and tabs

Pathogens and politics: further evidence that parasite prevalence predicts authoritarianism.

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Murray, Damian R; Schaller, Mark; Suedfeld, Peter

2013-01-01

According to a "parasite stress" hypothesis, authoritarian governments are more likely to emerge in regions characterized by a high prevalence of disease-causing pathogens. Recent cross-national evidence is consistent with this hypothesis, but there are inferential limitations associated with that evidence. We report two studies that address some of these limitations, and provide further tests of the hypothesis. Study 1 revealed that parasite prevalence strongly predicted cross-national differences on measures assessing individuals' authoritarian personalities, and this effect statistically mediated the relationship between parasite prevalence and authoritarian governance. The mediation result is inconsistent with an alternative explanation for previous findings. To address further limitations associated with cross-national comparisons, Study 2 tested the parasite stress hypothesis on a sample of traditional small-scale societies (the Standard Cross-Cultural Sample). Results revealed that parasite prevalence predicted measures of authoritarian governance, and did so even when statistically controlling for other threats to human welfare. (One additional threat-famine-also uniquely predicted authoritarianism.) Together, these results further substantiate the parasite stress hypothesis of authoritarianism, and suggest that societal differences in authoritarian governance result, in part, from cultural differences in individuals' authoritarian personalities.

Paradigms for parasite conservation.

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Dougherty, Eric R; Carlson, Colin J; Bueno, Veronica M; Burgio, Kevin R; Cizauskas, Carrie A; Clements, Christopher F; Seidel, Dana P; Harris, Nyeema C

2016-08-01

Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth's biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us farther from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. We argue the protection of parasitic biodiversity requires a paradigm shift in the perception and valuation of their role as consumer species, similar to that of apex predators in the mid-20th century. Beyond recognizing parasites as vital trophic regulators, existing tools available to conservation practitioners should explicitly account for the unique threats facing dependent species. We built upon concepts from epidemiology and economics (e.g., host-density threshold and cost-benefit analysis) to devise novel metrics of margin of error and minimum investment for parasite conservation. We define margin of error as the risk of accidental host extinction from misestimating equilibrium population sizes and predicted oscillations, while minimum investment represents the cost associated with conserving the additional hosts required to maintain viable parasite populations. This framework will aid in the identification of readily conserved parasites that present minimal health risks. To establish parasite conservation, we propose an extension of population viability analysis for host-parasite assemblages to assess extinction risk. In the direst cases, ex situ breeding programs for parasites should be evaluated to maximize success without undermining host protection. Though parasitic species pose a considerable conservation challenge, adaptations to conservation tools will help protect parasite biodiversity in the face of

Parasitic infections in juveniles of Arapaima gigas (Schinz, 1822) cultivated in the Peruvian Amazon.

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Delgado, Patrick Mathews; Delgado, John Paul Mathews; Orbe, Rosa Ismińo

2013-01-01

The paiche, Arapaima gigas represents a socio-economically important species in the Peruvian Amazon, and actually an intensive production for human consumption has emerged during the last years. Therefore, more studies are required in fish farming development, especially concerning populations of parasites that affect fish production yields. Eighty specimens of paiche collected between September and October of 2011 from semi-intensive fish farm in Loreto State, Peru, were examined for their helminthic parasites. Five species were recorded parasitizing A. gigas: Dawestrema cycloancistrium and Dawestrema cycloancistrioides (Monogenea) on gills, Trichodina sp. (Protozoa) on the skin, Caballerotrema arapaimense (Trematoda) in stomachs and Philometra senticosa (Nematoda) in the swim bladder. Highest prevalence was recorded for D. cycloancistrium (100.0%), D. cycloancistrioides (83.0%) and Trichodina sp. (50.0%) and highest values of mean intensity and mean abundance were recorded for D. cycloancistrium (260) parasites per individual. The results confirm the necessity of constant monitoring of fish, seeking the diagnosis and timely control of infestations with parasites, in order to eradicate the mortality of the host that leads unviable the fish farming intended for human consumption.

Phylogeographic Evidence for 2 Genetically Distinct Zoonotic Plasmodium knowlesi Parasites, Malaysia.

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Yusof, Ruhani; Ahmed, Md Atique; Jelip, Jenarun; Ngian, Hie Ung; Mustakim, Sahlawati; Hussin, Hani Mat; Fong, Mun Yik; Mahmud, Rohela; Sitam, Frankie Anak Thomas; Japning, J Rovie-Ryan; Snounou, Georges; Escalante, Ananias A; Lau, Yee Ling

2016-08-01

Infections of humans with the zoonotic simian malaria parasite Plasmodium knowlesi occur throughout Southeast Asia, although most cases have occurred in Malaysia, where P. knowlesi is now the dominant malaria species. This apparently skewed distribution prompted an investigation of the phylogeography of this parasite in 2 geographically separated regions of Malaysia, Peninsular Malaysia and Malaysian Borneo. We investigated samples collected from humans and macaques in these regions. Haplotype network analyses of sequences from 2 P. knowlesi genes, type A small subunit ribosomal 18S RNA and cytochrome c oxidase subunit I, showed 2 genetically distinct divergent clusters, 1 from each of the 2 regions of Malaysia. We propose that these parasites represent 2 distinct P. knowlesi types that independently became zoonotic. These types would have evolved after the sea-level rise at the end of the last ice age, which separated Malaysian Borneo from Peninsular Malaysia.

Parasite species of the endangered Iberian wolf (Canis lupus signatus and a sympatric widespread carnivore

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Ana Figueiredo

2016-08-01

Full Text Available Parasites have a profound impact on wildlife population dynamics. However, until some years ago, studies on the occurrence and prevalence of wildlife parasites were neglected comparatively with the studies on humans and domestic animals. In this study, we determined the parasite prevalence of two sympatric wild canids: the endangered Iberian wolf (Canis lupus signatus and the widespread red fox (Vulpes vulpes, in central Portugal. From November 2014 to July 2015, fresh fecal samples from both species were collected monthly in several transects distributed throughout the study area. All samples were submitted to several coprological techniques. In total, 6 helminth parasites (Crenosoma vulpis, Angiostrongylus vasorum, Toxocara canis, Trichuris vulpis, Ancylostomatidae, Toxascaris leonina, and a protozoa (Balantidium coli were identified based on size and morphology. The red fox was infected by seven different parasites while the Iberian wolf was infected by four. All parasites present in wolf were also present in the red fox. C. vulpis had the higher prevalence in red fox, while Ancylostomatidae were the most prevalent parasites in wolf. To our knowledge, this is the first study in this isolated subpopulation of the Iberian wolf. Our results show that both carnivores carry parasites that are of concern as they are pathogenic to humans and other wild and domestic animals. We suggest that surveillance programs must also include monitoring protocols of wildlife; particularly endangered species.

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

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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.

In vitro activity of the beta-carboline alkaloids harmane, harmine, and harmaline toward parasites of the species Leishmania infantum.

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Di Giorgio, C; Delmas, F; Ollivier, E; Elias, R; Balansard, G; Timon-David, P

2004-01-01

Harmane, harmine, and harmaline were investigated for their in vitro antileishmanial activity toward parasites of the species Leishmania infantum. Harmane and Harmine displayed a moderate antiproliferative activity toward human monocytes and exerted a weak antileishmanial activity toward both the promastigote and the amastigote forms of the parasite. Their mechanism of action on the promastigote form of the parasite involved interactions with DNA metabolism leading to an accumulation of parasites in the S-G(2)M phases of the cell-cycle. Harmaline, at the contrary, was deprived from toxicity toward human cells and Leishmania promastigotes, however it exerted a strong antileishmanial activity toward the intracellular amastigote form of the parasite. This property was shown to partly result from the capacity of the molecule to prevent parasite internalization within macrophages by inhibiting Leishmania PKC activity.

Isolation of Intestinal Parasites of Public Health Importance from Cockroaches (Blattella germanica) in Jimma Town, Southwestern Ethiopia.

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Hamu, Haji; Debalke, Serkadis; Zemene, Endalew; Birlie, Belay; Mekonnen, Zeleke; Yewhalaw, Delenasaw

2014-01-01

Cockroaches are claimed to be mechanical transmitters of disease causing microorganisms such as intestinal parasites, bacteria, fungi, and viruses. This study assessed the potential of the German cockroach Blattella germanica in the mechanical transmission of intestinal parasites of public health importance. A total of 2010 cockroaches were collected from 404 households in Jimma Town, southwestern Ethiopia. All the collected cockroaches were identified to species as B. germanica. The contents of their gut and external body parts were examined for the presence of intestinal parasites. Overall, 152 (75.6%) of the 210 batches were found to harbor at least one species of human intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, Taenia spp, Strongyloides-like parasite, Entamoeba histolytica/dispar/moshkovski, Giardia duodenalis and Balantidium coli were detected from gut contents. Moreover, parasites were also isolated from the external surface in 22 (10.95%) of the batches. There was significant difference in parasite carriage rate of the cockroaches among the study sites (P = 0.013). In conclusion, B. germanica was found to harbor intestinal parasites of public health importance. Hence, awareness on the potential role of cockroaches in the mechanical transmission of human intestinal parasites needs to be created. Moreover, further identification of the Strongyloides-like worm is required using molecular diagnostics.

Isolation of Intestinal Parasites of Public Health Importance from Cockroaches (Blattella germanica in Jimma Town, Southwestern Ethiopia

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Haji Hamu

2014-01-01

Full Text Available Cockroaches are claimed to be mechanical transmitters of disease causing microorganisms such as intestinal parasites, bacteria, fungi, and viruses. This study assessed the potential of the German cockroach Blattella germanica in the mechanical transmission of intestinal parasites of public health importance. A total of 2010 cockroaches were collected from 404 households in Jimma Town, southwestern Ethiopia. All the collected cockroaches were identified to species as B. germanica. The contents of their gut and external body parts were examined for the presence of intestinal parasites. Overall, 152 (75.6% of the 210 batches were found to harbor at least one species of human intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, Taenia spp, Strongyloides-like parasite, Entamoeba histolytica/dispar/moshkovski, Giardia duodenalis and Balantidium coli were detected from gut contents. Moreover, parasites were also isolated from the external surface in 22 (10.95% of the batches. There was significant difference in parasite carriage rate of the cockroaches among the study sites (P=0.013. In conclusion, B. germanica was found to harbor intestinal parasites of public health importance. Hence, awareness on the potential role of cockroaches in the mechanical transmission of human intestinal parasites needs to be created. Moreover, further identification of the Strongyloides-like worm is required using molecular diagnostics.

Evidence-based annotation of the malaria parasite's genome using comparative expression profiling.

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Yingyao Zhou

2008-02-01

Full Text Available A fundamental problem in systems biology and whole genome sequence analysis is how to infer functions for the many uncharacterized proteins that are identified, whether they are conserved across organisms of different phyla or are phylum-specific. This problem is especially acute in pathogens, such as malaria parasites, where genetic and biochemical investigations are likely to be more difficult. Here we perform comparative expression analysis on Plasmodium parasite life cycle data derived from P. falciparum blood, sporozoite, zygote and ookinete stages, and P. yoelii mosquito oocyst and salivary gland sporozoites, blood and liver stages and show that type II fatty acid biosynthesis genes are upregulated in liver and insect stages relative to asexual blood stages. We also show that some universally uncharacterized genes with orthologs in Plasmodium species, Saccharomyces cerevisiae and humans show coordinated transcription patterns in large collections of human and yeast expression data and that the function of the uncharacterized genes can sometimes be predicted based on the expression patterns across these diverse organisms. We also use a comprehensive and unbiased literature mining method to predict which uncharacterized parasite-specific genes are likely to have roles in processes such as gliding motility, host-cell interactions, sporozoite stage, or rhoptry function. These analyses, together with protein-protein interaction data, provide probabilistic models that predict the function of 926 uncharacterized malaria genes and also suggest that malaria parasites may provide a simple model system for the study of some human processes. These data also provide a foundation for further studies of transcriptional regulation in malaria parasites.

Leishmania development in sand flies: parasite-vector interactions overview.

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Dostálová, Anna; Volf, Petr

2012-12-03

Leishmaniases are vector-borne parasitic diseases with 0.9 - 1.4 million new human cases each year worldwide. In the vectorial part of the life-cycle, Leishmania development is confined to the digestive tract. During the first few days after blood feeding, natural barriers to Leishmania development include secreted proteolytic enzymes, the peritrophic matrix surrounding the ingested blood meal and sand fly immune reactions. As the blood digestion proceeds, parasites need to bind to the midgut epithelium to avoid being excreted with the blood remnant. This binding is strictly stage-dependent as it is a property of nectomonad and leptomonad forms only. While the attachment in specific vectors (P. papatasi, P. duboscqi and P. sergenti) involves lipophosphoglycan (LPG), this Leishmania molecule is not required for parasite attachment in other sand fly species experimentally permissive for various Leishmania. During late-stage infections, large numbers of parasites accumulate in the anterior midgut and produce filamentous proteophosphoglycan creating a gel-like plug physically obstructing the gut. The parasites attached to the stomodeal valve cause damage to the chitin lining and epithelial cells of the valve, interfering with its function and facilitating reflux of parasites from the midgut. Transformation to metacyclic stages highly infective for the vertebrate host is the other prerequisite for effective transmission. Here, we review the current state of knowledge of molecular interactions occurring in all these distinct phases of parasite colonization of the sand fly gut, highlighting recent discoveries in the field.

PREVALENCE OF INTESTINAL PARASITES AMONG FOOD HANDLERS IN WESTERN IRAN

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Farnaz Kheirandish

2014-04-01

Full Text Available Parasitic infection is one of the problems that affect human health, especially in developing countries. In this study, all of the fast food shops, restaurants, and roast meat outlets of Khorramabad (Western Iran and all the staff employed by them, some 210 people, were selected through a census and their stools were examined for the presence of parasites. The parasitological tests of direct wet-mount, Lugol's iodine staining, formaldehyde-ether sedimentation and Trichrome staining techniques were performed on the samples. The data was analyzed with a chi-square test and logistic regression was selected as the analytical model. The results showed 19 (9% stool specimens were positive for different intestinal parasites. These intestinal parasites included Giardia lamblia2.9%, Entamoeba coli 4.3%, Blastocystis sp. 1.4%, and Hymenolepis nana 0.5%. There was a significant difference between the presence of a valid health card, awareness of transmission of intestinal parasites, participation in training courses in environmental health with intestinal parasites (p 0.05. To control parasitic infection in food handlers, several strategies are recommended such as stool examinations every three months, public education, application of health regulations, controlling the validity of health cards and training on parasitic infection transmission. In this regard, the findings of the present study can be used as a basis to develop preventive programs targeting food handlers because the spread of disease via them is a common problem worldwide.

Prevalence of intestinal parasites among food handlers in Western Iran.

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Kheirandish, Farnaz; Tarahi, Mohammad Javad; Ezatpour, Behrouz

2014-01-01

Parasitic infection is one of the problems that affect human health, especially in developing countries. In this study, all of the fast food shops, restaurants, and roast meat outlets of Khorramabad (Western Iran) and all the staff employed by them, some 210 people, were selected through a census and their stools were examined for the presence of parasites. The parasitological tests of direct wet-mount, Lugol's iodine staining, formaldehyde-ether sedimentation and Trichrome staining techniques were performed on the samples. The data was analyzed with a chi-square test and logistic regression was selected as the analytical model. The results showed 19 (9%) stool specimens were positive for different intestinal parasites. These intestinal parasites included Giardia lamblia 2.9%, Entamoeba coli 4.3%, Blastocystis sp. 1.4%, and Hymenolepis nana 0.5%. There was a significant difference between the presence of a valid health card, awareness of transmission of intestinal parasites, participation in training courses in environmental health with intestinal parasites (p 0.05). To control parasitic infection in food handlers, several strategies are recommended such as stool examinations every three months, public education, application of health regulations, controlling the validity of health cards and training on parasitic infection transmission. In this regard, the findings of the present study can be used as a basis to develop preventive programs targeting food handlers because the spread of disease via them is a common problem worldwide.

A Feast of Malaria Parasite Genomes.

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Carlton, Jane M; Sullivan, Steven A

2017-03-08

The Plasmodium genus has evolved over time and across hosts, complexifying our understanding of malaria. In a recent Nature paper, Rutledge et al. (2017) describe the genome sequences of three major human malaria parasite species, providing insight into Plasmodium evolution and raising the question of how many species there are. Copyright © 2017 Elsevier Inc. All rights reserved.

One Health: parasites and beyond.

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Blake, Damer P; Betson, Martha

2017-01-01

The field of parasitism is broad, encompassing relationships between organisms where one benefits at the expense of another. Traditionally the discipline focuses on eukaryotes, with the study of bacteria and viruses complementary but distinct. Nonetheless, parasites vary in size and complexity from single celled protozoa, to enormous plants like those in the genus Rafflesia. Lifecycles range from obligate intracellular to extensive exoparasitism. Examples of parasites include high-profile medical and zoonotic pathogens such as Plasmodium, veterinary pathogens of wild and captive animals and many of the agents which cause neglected tropical diseases, stretching to parasites which infect plants and other parasites (e.g. Kikuchi et al. 2011; Hotez et al. 2014; Blake et al. 2015; Hemingway, 2015; Meekums et al. 2015; Sandlund et al. 2015). The breadth of parasitology has been matched by the variety of ways in which parasites are studied, drawing upon biological, chemical, molecular, epidemiological and other expertise. Despite such breadth bridging between disciplines has commonly been problematic, regardless of extensive encouragement from government agencies, peer audiences and funding bodies promoting multidisciplinary research. Now, progress in understanding and collaboration can benefit from establishment of the One Health concept (Zinsstag et al. 2012; Stark et al. 2015). One Health draws upon biological, environmental, medical, veterinary and social science disciplines in order to improve human, animal and environmental health, although it remains tantalizingly difficult to engage many relevant parties. For infectious diseases traditional divides have been exacerbated as the importance of wildlife reservoirs, climate change, food production systems and socio-economic diversity have been recognized but often not addressed in a multidisciplinary manner. In response the 2015 Autumn Symposium organized by the British Society for Parasitology (BSP; https

Trichomonas vaginalis exosomes deliver cargo to host cells and mediate host∶parasite interactions.

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Olivia Twu

Full Text Available Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogential tract where it remains extracellular and adheres to epithelial cells. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Here, we use a combination of methodologies including cell fractionation, immunofluorescence and electron microscopy, RNA, proteomic and cytokine analyses and cell adherence assays to examine pathogenic properties of T. vaginalis. We have found that T.vaginalis produces and secretes microvesicles with physical and biochemical properties similar to mammalian exosomes. The parasite-derived exosomes are characterized by the presence of RNA and core, conserved exosomal proteins as well as parasite-specific proteins. We demonstrate that T. vaginalis exosomes fuse with and deliver their contents to host cells and modulate host cell immune responses. Moreover, exosomes from highly adherent parasite strains increase the adherence of poorly adherent parasites to vaginal and prostate epithelial cells. In contrast, exosomes from poorly adherent strains had no measurable effect on parasite adherence. Exosomes from parasite strains that preferentially bind prostate cells increased binding of parasites to these cells relative to vaginal cells. In addition to establishing that parasite exosomes act to modulate host∶parasite interactions, these studies are the first to reveal a potential role for exosomes in promoting parasite∶parasite communication and host cell colonization.

Intestinal parasites in First World War German soldiers from "Kilianstollen", Carspach, France.

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Le Bailly, Matthieu; Landolt, Michaël; Mauchamp, Leslie; Dufour, Benjamin

2014-01-01

Paleoparasitological investigations revealed the presence of intestinal helminths in samples taken from the abdominal cavities of two German soldiers, recovered in the First World War site named "Kilianstollen" in Carspach, France. Eggs from roundworm, whipworm, tapeworm and capillariids were identified. The morphological and morphometrical comparison, followed by statistical analyses, showed that the Carspach capillariid eggs are similar to rodent parasites. Poor sanitary conditions in the trenches, the lack of knowledge of parasites, and the widespread presence of commensal animals, can explain the occurrence of such parasites in human intestines. This study is the second dealing with 20th century human samples. It confirms the presence of intestinal worms in First World War German soldiers. In this case study, the application of statistics to precise measurements facilitated the diagnosis of ancient helminth eggs and completed the microscopic approach.

Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis

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Karina Mastropasqua Rebello

2012-09-01

Full Text Available Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1 were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3 were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.

Defining the protein interaction network of human malaria parasite Plasmodium falciparum

KAUST Repository

Ramaprasad, Abhinay; Pain, Arnab; Ravasi, Timothy

2012-01-01

Malaria, caused by the protozoan parasite Plasmodium falciparum, affects around 225. million people yearly and a huge international effort is directed towards combating this grave threat to world health and economic development. Considerable

Parasites as prey

NARCIS (Netherlands)

Goedknegt, M.A.; Welsh, J.E.; Thieltges, D.W.

2012-01-01

Parasites are usually considered to use their hosts as a resource for energy. However, there is increasing awareness that parasites can also become a resource themselves and serve as prey for other organisms. Here we describe various types of predation in which parasites act as prey for other

Prevalence of potentially zoonotic gastrointestinal parasites in ...

African Journals Online (AJOL)

Conclusion: The high prevalence of zoonotic parasites detected in dog faeces from Ibadan metropolis showed that infected stray dogs roam the streets and constitute potential risk to human health. This study suggests the need for enforcement of laws restraining roaming or straying dogs and proper veterinary care of dogs.

Parasites: Water

Science.gov (United States)

... Consultations, and General Public. Contact Us Parasites Home Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir Parasites can live in natural water sources. When outdoors, treat your water before drinking ...

Living With Parasites in Palo Verde National Park

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Eben Kirksey

2012-11-01

Full Text Available Bruno Latour has tried to bring a parliamentary democracy to the domain of nature. Wading through the swamps of Palo Verde, a national park in the Guanacaste Province of Costa Rica, and wandering onto neighbouring agricultural lands, I failed to find a central place where people were speaking for nature. Departing from a failed attempt to speak for another species (the fringe-toed foam frog, this paper considers how diverging values and obligations shape relationships in multi-species worlds. As spokespersons articulated competing visions of nature on the borderlands of Palo Verde, multiple social and ecological worlds went to war. The haunting specter of capital joined the fray—animating the movements of cattle, grasses with animal rhizomes, rice seeds, and flighty ducks across national borders and through fragmented landscapes. Amidst this warfare, the fringe-toed foam frog was just one tenacious parasite, a noisy agent eating at the table of another, which began to flourish in worlds designed with the well-being of others in mind. Cattails, charismatic birds, and a multitude of insects began interrupting human dreams and schemes. Final solutions to the problem of living with parasites failed in Palo Verde. Humans and parasites, who became para-selves of one another, maintained an abiding presence in the landscape.

Ancient DNA from latrines in Northern Europe and the Middle East (500 BC–1700 AD) reveals past parasites and diet

DEFF Research Database (Denmark)

Søe, Martin Jensen; Nejsum, Peter; Seersholm, Frederik Valeur

2018-01-01

, vertebrate and plant DNA proved highly informative in the study of ancient health, human-animal interactions as well as animal and plant dietary components. Most prominent were finding of soil-borne parasites transmitted directly between humans, but also meat-borne parasites that require consumption of raw...... or undercooked fish and pork. The detection of parasites for which sheep, horse, dog, pig, and rodents serves as definitive hosts are clear markers of domestic and synanthropic animals living in closer proximity of the respective sites. Finally, the reconstruction of full mitochondrial parasite genomes from...

The magnitude and risk factors of intestinal parasitic infection in relation to Human Immunodeficiency Virus infection and immune status, at ALERT Hospital, Addis Ababa, Ethiopia.

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Taye, Biruhalem; Desta, Kassu; Ejigu, Selamawit; Dori, Geme Urge

2014-06-01

Human Immunodeficiency Virus (HIV) and intestinal parasitic infections are among the main health problems in developing countries like Ethiopia. Particularly, co-infections of these diseases would worsen the progression of HIV to Acquired Immunodeficiency Syndrome (AIDS). The purpose of this study was to determine the magnitude and risk factors for intestinal parasites in relation to HIV infection and immune status. The study was conducted in (1) HIV positive on antiretroviral therapy (ART) and (2) ART naïve HIV positive patients, and (3) HIV-negative individuals, at All African Leprosy and Tuberculosis (TB) Eradication and Rehabilitation Training Center (ALERT) hospital in Addis Ababa, Ethiopia. Study participants were interviewed using structured questionnaires to obtain socio-demographic characteristics and assess risk factors associated with intestinal parasitic infection. Intestinal parasites were identified from fecal samples by direct wet mount, formol ether concentration, and modified Ziehl-Neelsen staining techniques. The immune status was assessed by measuring whole blood CD4 T-cell count. The overall magnitude of intestinal parasite was 35.08%. This proportion was different among study groups with 39.2% (69/176), 38.83% (40/103) and 27.14% (38/140) in ART naïve HIV positives patients, in HIV negatives, and in HIV positive on ART patients respectively. HIV positive patients on ART had significantly lower magnitude of intestinal parasitic infection compared to HIV negative individuals. Intestinal helminths were significantly lower in HIV positive on ART and ART naïve patients than HIV negatives. Low monthly income, and being married, divorced or widowed were among the socio-demographic characteristics associated with intestinal parasitic infection. No association was observed between the magnitude of intestinal parasites and CD4 T-cell count. However, Cryptosporidium parvum, and Isospora belli were exclusively identified in individuals with CD4 T

Host Mitochondrial Association Evolved in the Human Parasite Toxoplasma gondii via Neofunctionalization of a Gene Duplicate.

Science.gov (United States)

Adomako-Ankomah, Yaw; English, Elizabeth D; Danielson, Jeffrey J; Pernas, Lena F; Parker, Michelle L; Boulanger, Martin J; Dubey, Jitender P; Boyle, Jon P

2016-05-01

In Toxoplasma gondii, an intracellular parasite of humans and other animals, host mitochondrial association (HMA) is driven by a gene family that encodes multiple mitochondrial association factor 1 (MAF1) proteins. However, the importance of MAF1 gene duplication in the evolution of HMA is not understood, nor is the impact of HMA on parasite biology. Here we used within- and between-species comparative analysis to determine that the MAF1 locus is duplicated in T. gondii and its nearest extant relative Hammondia hammondi, but not another close relative, Neospora caninum Using cross-species complementation, we determined that the MAF1 locus harbors multiple distinct paralogs that differ in their ability to mediate HMA, and that only T. gondii and H. hammondi harbor HMA(+) paralogs. Additionally, we found that exogenous expression of an HMA(+) paralog in T. gondii strains that do not normally exhibit HMA provides a competitive advantage over their wild-type counterparts during a mouse infection. These data indicate that HMA likely evolved by neofunctionalization of a duplicate MAF1 copy in the common ancestor of T. gondii and H. hammondi, and that the neofunctionalized gene duplicate is selectively advantageous. Copyright © 2016 by the Genetics Society of America.

Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal.

Science.gov (United States)

Messenger, Louisa A; Garcia, Lineth; Vanhove, Mathieu; Huaranca, Carlos; Bustamante, Marinely; Torrico, Marycruz; Torrico, Faustino; Miles, Michael A; Llewellyn, Martin S

2015-05-01

An improved understanding of how a parasite species exploits its genetic repertoire to colonize novel hosts and environmental niches is crucial to establish the epidemiological risk associated with emergent pathogenic genotypes. Trypanosoma cruzi, a genetically heterogeneous, multi-host zoonosis, provides an ideal system to examine the sylvatic diversification of parasitic protozoa. In Bolivia, T. cruzi I, the oldest and most widespread genetic lineage, is pervasive across a range of ecological clines. High-resolution nuclear (26 loci) and mitochondrial (10 loci) genotyping of 199 contemporaneous sylvatic TcI clones was undertaken to provide insights into the biogeographical basis of T. cruzi evolution. Three distinct sylvatic parasite transmission cycles were identified: one highland population among terrestrial rodent and triatomine species, composed of genetically homogenous strains (Ar = 2.95; PA/L = 0.61; DAS = 0.151), and two highly diverse, parasite assemblages circulating among predominantly arboreal mammals and vectors in the lowlands (Ar = 3.40 and 3.93; PA/L = 1.12 and 0.60; DAS = 0.425 and 0.311, respectively). Very limited gene flow between neighbouring terrestrial highland and arboreal lowland areas (distance ~220 km; FST = 0.42 and 0.35) but strong connectivity between ecologically similar but geographically disparate terrestrial highland ecotopes (distance >465 km; FST = 0.016-0.084) strongly supports ecological host fitting as the predominant mechanism of parasite diversification. Dissimilar heterozygosity estimates (excess in highlands, deficit in lowlands) and mitochondrial introgression among lowland strains may indicate fundamental differences in mating strategies between populations. Finally, accelerated parasite dissemination between densely populated, highland areas, compared to uninhabited lowland foci, likely reflects passive, long-range anthroponotic dispersal. The impact of humans on the risk of epizootic Chagas disease transmission in

Human parasites in the Roman World: health consequences of conquering an empire.

Science.gov (United States)

Mitchell, Piers D

2017-01-01

The archaeological evidence for parasites in the Roman era is presented in order to demonstrate the species present at that time, and highlight the health consequences for people living under Roman rule. Despite their large multi-seat public latrines with washing facilities, sewer systems, sanitation legislation, fountains and piped drinking water from aqueducts, we see the widespread presence of whipworm (Trichuris trichiura), roundworm (Ascaris lumbricoides) and Entamoeba histolytica that causes dysentery. This would suggest that the public sanitation measures were insufficient to protect the population from parasites spread by fecal contamination. Ectoparasites such as fleas, head lice, body lice, pubic lice and bed bugs were also present, and delousing combs have been found. The evidence fails to demonstrate that the Roman culture of regular bathing in the public baths reduced the prevalence of these parasites. Fish tapeworm was noted to be widely present, and was more common than in Bronze and Iron Age Europe. It is possible that the Roman enthusiasm for fermented, uncooked fish sauce (garum) may have facilitated the spread of this helminth. Roman medical practitioners such as Galen were aware of intestinal worms, explaining their existence and planning treatment using the humoural theory of the period.

Zoonotic enteric parasites transmitted from dogs in Egypt with special concern to Toxocara canis infection

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Maysa A. I. Awadallah

2015-08-01

Full Text Available Aim: This work aimed to study the role played by dogs in transmitting zoonotic enteric parasites to humans in Egypt and to analyze the risk factors associated with the occurrence of such infection in dogs. Serodiagnosis of anti-Toxocara immunoglobulin G (IgG antibodies among human beings as well as analyzing risk factors predispose to Toxocara canis infection in human beings are another objectives of this study. Materials and Methods: From June to December 2013, a total of 130 fecal samples from 4 dog populations (Military, nomadic and domiciled dogs from rural and high standard districts and 150 stool samples of 6 occupational groups were examined for the presence of enteric parasitic infection. Moreover, 150 serum samples were collected from humans from whom stool samples were collected and examined for the presence of anti-T. canis antibodies. Results: Enteric parasites were detected in 30% of fecal samples from 4 dog populations in Egypt. High infectivity had been reported in nomadic dogs (63.33% (Crude odds ratios [COR]=67.36, 95% confidence interval [CI]=8.09-560.8, p˂0.000, followed by domiciled dogs from rural areas (40% (COR=26, 95% CI=3.14-215.54, p=0.003, domiciled dogs from high standard areas (23.33% (COR=11.87, 95% CI=1.37-102.69, p=0.025 and military dogs (2.5%. Twelve species of enteric parasites were identified, Ancylostomatidae (6.15%, T. canis and Cryptosporidium spp. (5.38%, each, Heterophyes spp. (3.85%, Toxocara leonina and Blastocystis spp. (3.07%, Taenidae eggs (2.31%, Hymenolepis diminuta (1.54% and Entamoeba canis, Cyclospora cayetanensis, and Paragonimus spp. (0.77%, each. Univariate logestic regression revealed significant association of age (COR=4.73, 95% CI=2.13-10.53, p˂0.000, gender (COR=2.63, 95% CI=1.22-5.68, p˂0.014, housing system (COR=5.10, 95% CI=2.04-12.75, p˂0.000 with enteric parasitic infection in dogs. However, breeds (COR=6.91, 95% CI=0.88-54.52, p=0.067 and type of feeding (COR ranged from 3.5 to

The neurotropic parasite Toxoplasma gondii increases dopamine metabolism

Science.gov (United States)

The common parasite Toxoplasma gondii induces behavioral alterations in its hosts including phenotypes increasing the likelihood of its transmission in rodents and reports of psychobehavioral alterations in humans. We have found that elevated levels of dopamine are associated with the encysted stage...

Occurrence of Intestinal Parasitic Contamination in Select Consumed Local Raw Vegetables and Fruits in Kuantan, Pahang

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Yusof, Afzan Mat; Mohammad, Mardhiah; Abdullahi, Muna Abshir; Mohamed, Zeehaida; Zakaria, Robaiza; Wahab, Ridhwan Abdul

2017-01-01

Intestinal parasitic infections are one of the most common causes of human diseases that result in serious health and economic issues in many developing and developed countries. Raw vegetables and fruits play an important role in transmitting parasites to humans. Hence, the aim of this study was to investigate the parasitological contamination of select commonly consumed local leafy vegetables and fruits in Kuantan, Malaysia. One kilogram of locally consumed raw vegetables and fruits were collected randomly from the Kuantan wet market (Pasar Tani) during the monsoon season (November 2014–January 2015) and the dry season (February 2015–April 2015). A standard wet mount procedure and modified Ziehl-Neelsen staining were used for the detection of parasites. In the present study, the examination of vegetables revealed five different parasite species. The vegetable samples collected from Kuantan’s wet market were positive for both helminthes and protozoa. However, the fruits samples were negative for parasitic contamination. Pegaga was the most contaminated leafy vegetable in this study, and Strongyloides was the parasite found most frequently. Furthermore, there was a high diversity in the type of parasites observed during the dry season compared to the monsoon season. Therefore, further action should be taken to reduce the occurrence of parasitic contamination in vegetables by implementing the principles of good agricultural practice and improving water treatment efficacy. PMID:28228914

Controlling human oesophagostomiasis in northern Ghana

NARCIS (Netherlands)

Ziem, Juventus Benogle

2006-01-01

This thesis describes aspects of the epidemiology and attempts to control infection and pathology due to the nematode parasite Oesophagostomum bifurcum . In northern Ghana and Togo O. bifurcum is an important parasite of humans; elsewhere it is predominantly seen as a parasite of non-human primates.

Transformation of the rodent malaria parasite Plasmodium chabaudi.

Science.gov (United States)

Spence, Philip J; Cunningham, Deirdre; Jarra, William; Lawton, Jennifer; Langhorne, Jean; Thompson, Joanne

2011-04-01

The rodent malaria parasite Plasmodium chabaudi chabaudi shares many features with human malaria species, including P. falciparum, and is the in vivo model of choice for many aspects of malaria research in the mammalian host, from sequestration of parasitized erythrocytes, to antigenic variation and host immunity and immunopathology. This protocol describes an optimized method for the transformation of mature blood-stage P.c. chabaudi and a description of a vector that targets efficient, single crossover integration into the P.c. chabaudi genome. Transformed lines are reproducibly generated and selected within 14-20 d, and show stable long-term protein expression even in the absence of drug selection. This protocol, therefore, provides the scientific community with a robust and reproducible method to generate transformed P.c. chabaudi parasites expressing fluorescent, bioluminescent and model antigens that can be used in vivo to dissect many of the fundamental principles of malaria infection.

Melatonin-Induced Temporal Up-Regulation of Gene Expression Related to Ubiquitin/Proteasome System (UPS in the Human Malaria Parasite Plasmodium falciparum

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Fernanda C. Koyama

2014-12-01

Full Text Available There is an increasing understanding that melatonin and the ubiquitin/ proteasome system (UPS interact to regulate multiple cellular functions. Post-translational modifications such as ubiquitination are important modulators of signaling processes, cell cycle and many other cellular functions. Previously, we reported a melatonin-induced upregulation of gene expression related to ubiquitin/proteasome system (UPS in Plasmodium falciparum, the human malaria parasite, and that P. falciparum protein kinase 7 influences this process. This implies a role of melatonin, an indolamine, in modulating intraerythrocytic development of the parasite. In this report we demonstrate by qPCR analysis, that melatonin induces gene upregulation in nine out of fourteen genes of the UPS, consisting of the same set of genes previously reported, between 4 to 5 h after melatonin treatment. We demonstrate that melatonin causes a temporally controlled gene expression of UPS members.

A systematic review of zoonotic enteric parasitic diseases among nomadic and pastoral people.

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Amber N Barnes

Full Text Available Zoonotic enteric parasites are ubiquitous and remain a public health threat to humans due to our close relationship with domestic animals and wildlife, inadequate water, sanitation, and hygiene practices and diet. While most communities are now sedentary, nomadic and pastoral populations still exist and experience unique exposure risks for acquiring zoonotic enteric parasites. Through this systematic review we sought to summarize published research regarding pathogens present in nomadic populations and to identify the risk factors for their infection.Using systematic review guidelines set forth by PRISMA, research articles were identified, screened and summarized based on exclusion criteria for the documented presence of zoonotic enteric parasites within nomadic or pastoral human populations. A total of 54 articles published between 1956 and 2016 were reviewed to determine the pathogens and exposure risks associated with the global transhumance lifestyle.The included articles reported more than twenty different zoonotic enteric parasite species and illustrated several risk factors for nomadic and pastoralist populations to acquire infection including; a animal contact, b food preparation and diet, and c household characteristics. The most common parasite studied was Echinococcosis spp. and contact with dogs was recognized as a leading risk factor for zoonotic enteric parasites followed by contact with livestock and/or wildlife, water, sanitation, and hygiene barriers, home slaughter of animals, environmental water exposures, household member age and sex, and consumption of unwashed produce or raw, unprocessed, or undercooked milk or meat.Nomadic and pastoral communities are at risk of infection with a variety of zoonotic enteric parasites due to their living environment, cultural and dietary traditions, and close relationship to animals. Global health efforts aimed at reducing the transmission of these animal-to-human pathogens must incorporate

Global issues in allergy and immunology: Parasitic infections and allergy.

Science.gov (United States)

Cruz, Alvaro A; Cooper, Philip J; Figueiredo, Camila A; Alcantara-Neves, Neuza M; Rodrigues, Laura C; Barreto, Mauricio L

2017-11-01

Allergic diseases are on the increase globally in parallel with a decrease in parasitic infection. The inverse association between parasitic infections and allergy at an ecological level suggests a causal association. Studies in human subjects have generated a large knowledge base on the complexity of the interrelationship between parasitic infection and allergy. There is evidence for causal links, but the data from animal models are the most compelling: despite the strong type 2 immune responses they induce, helminth infections can suppress allergy through regulatory pathways. Conversely, many helminths can cause allergic-type inflammation, including symptoms of "classical" allergic disease. From an evolutionary perspective, subjects with an effective immune response against helminths can be more susceptible to allergy. This narrative review aims to inform readers of the most relevant up-to-date evidence on the relationship between parasites and allergy. Experiments in animal models have demonstrated the potential benefits of helminth infection or administration of helminth-derived molecules on chronic inflammatory diseases, but thus far, clinical trials in human subjects have not demonstrated unequivocal clinical benefits. Nevertheless, there is sufficiently strong evidence to support continued investigation of the potential benefits of helminth-derived therapies for the prevention or treatment of allergic and other inflammatory diseases. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Impacts of globalisation on foodborne parasites.

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Robertson, Lucy J; Sprong, Hein; Ortega, Ynes R; van der Giessen, Joke W B; Fayer, Ron

2014-01-01

Globalisation is a manmade phenomenon encompassing the spread and movement of everything, animate and inanimate, material and intangible, around the planet. The intentions of globalisation may be worthy--but may also have unintended consequences. Pathogens may also be spread, enabling their establishment in new niches and exposing new human and animal populations to infection. The plethora of foodborne parasites that could be distributed by globalisation has only recently been acknowledged and will provide challenges for clinicians, veterinarians, diagnosticians, and everyone concerned with food safety. Globalisation may also provide the resources to overcome some of these challenges. It will facilitate sharing of methods and approaches, and establishment of systems and databases that enable control of parasites entering the global food chain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Parasites in marine food webs

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Lafferty, Kevin D.

2013-01-01

Most species interactions probably involve parasites. This review considers the extent to which marine ecologists should consider parasites to fully understand marine communities. Parasites are influential parts of food webs in estuaries, temperate reefs, and coral reefs, but their ecological importance is seldom recognized. Though difficult to observe, parasites can have substantial biomass, and they can be just as common as free-living consumers after controlling for body mass and trophic level. Parasites have direct impacts on the energetics of their hosts and some affect host behaviors, with ecosystem-level consequences. Although they cause disease, parasites are sensitive components of ecosystems. In particular, they suffer secondary extinctions due to biodiversity loss. Some parasites can also return to a system after habitat restoration. For these reasons, parasites can make good indicators of ecosystem integrity. Fishing can indirectly increase or decrease parasite populations and the effects of climate change on parasites are likely to be equally as complex.

Intestinal and external parasites of raccoon dogs (Nyctereutes procyonoides) in western Poland

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Osten-Sacken, Natalia; Słodkowicz-Kowalska, Anna; Pacoń, Jarosław; Skrzypczak, Łukasz; Werner, Anna

Parasites of an invasive species, the raccoon dog (Nyctereutes procyonoides) from western Poland were investigated to clarify poorly known ecological key aspects of the species. The research was conducted in two study areas: the Ujście Warty National Park and the Bogdaniec Forestry District. Intestinal samples were collected from the intestinal tracks of 39 dead animals and 51 faecal samples were collected in all seasons from latrines of raccoon dogs. Macro-parasites, their eggs and protozoan parasites were investigated to assess the taxonomic composition of parasites, the level of infection and the risk of potential transfer of dangerous parasites from raccoon dogs to people and native species. Among parasites potentially dangerous for human and native mammal species, Toxocara canis was found in the intestines and T. canis eggs, Cryptosporidium sp. oocysts and Entamoeba sp. cysts were identified in faecal samples. Sarcoptic mange was observed in the skin of two animals, whereas Diptera larvae (probably from the family Gasterophilidae) were found in the intestines of two other animals. This latter finding is very interesting, because Gasterophilidae are the typical parasites in horses and ungulates, but so far were never found in raccoon dogs.

Health-seeking behaviors and self-care practices of people with filarial lymphoedema in Nepal: a qualitative study.

Science.gov (United States)

Adhikari, Ram Kumar; Sherchand, Jeevan Bahadur; Mishra, Shiva Raj; Ranabhat, Kamal; Pokharel, Amrit; Devkota, Pramila; Mishra, Durga; Ghimire, Yadu Chandra; Gelal, Khageshwor; Paudel, Rajan; Wagle, Rajendra Raj

2015-01-01

Background. Lymphatic filariasis is endemic in Nepal. This study aimed to investigate health-seeking behaviors and self-care practices of people with filarial Lymphoedema in Nepal. Methods. A cross-sectional study was conducted using qualitative methods in three endemic districts. Twenty-three patients with current Lymphoedema were recruited in the study. Results. Hydrocele was found to be a well-known condition and a major health problem in the studied communities. People with Lymphoedema primarily sought health care from traditional healers, whereas sometimes home-based care was their first treatment. Later Ayurvedic and allopathic hospital-based care were sought. Respondents reported various psychological problems such as difficulty in engaging in sexual intercourse, anxiety, worry and stress, depression, low self-esteem, feeling weak, fear of being abandoned, and fear of transmitting disease to the children. Standard foot care practices except washing were largely absent. Conclusions. Lymphoedema in the limbs and hydrocele were found to be major health problems. The traditional health care providers were the first contact of care for the majority of respondents. Only a few patients had been practicing standard foot care practices.

Lipid Synthesis in Protozoan Parasites: a Comparison Between Kinetoplastids and Apicomplexans

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Ramakrishnan, Srinivasan; Serricchio, Mauro; Striepen, Boris; Bütikofer, Peter

2013-01-01

Lipid metabolism is of crucial importance for pathogens. Lipids serve as cellular building blocks, signalling molecules, energy stores, posttranslational modifiers, and pathogenesis factors. Parasites rely on a complex system of uptake and synthesis mechanisms to satisfy their lipid needs. The parameters of this system change dramatically as the parasite transits through the various stages of its life cycle. Here we discuss the tremendous recent advances that have been made in the understanding of the synthesis and uptake pathways for fatty acids and phospholipids in apicomplexan and kinetoplastid parasites, including Plasmodium, Toxoplasma, Cryptosporidium, Trypanosoma and Leishmania. Lipid synthesis differs in significant ways between parasites from both phyla and the human host. Parasites have acquired novel pathways through endosymbiosis, as in the case of the apicoplast, have dramatically reshaped substrate and product profiles, and have evolved specialized lipids to interact with or manipulate the host. These differences potentially provide opportunities for drug development. We outline the lipid pathways for key species in detail as they progress through the developmental cycle and highlight those that are of particular importance to the biology of the pathogens and/or are the most promising targets for parasite-specific treatment. PMID:23827884

Parasitic diseases

International Nuclear Information System (INIS)

Rozenshtraukh, L.S.

1983-01-01

Foundations of roentgenological semiotics of parasitic diseases of lungs, w hich are of the greatest practical value, are presented. Roentgenological pictu res of the following parasitic diseases: hydatid and alveolar echinococcosis, pa ragonimiasis, toxoplasmosis, ascariasis, amebiasis, bilharziasis (Schistosomias is) of lungs, are considered

Binding and Endocytosis of Bovine Hololactoferrin by the Parasite Entamoeba histolytica

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Guillermo Ortíz-Estrada

2015-01-01

Full Text Available Entamoeba histolytica is a human parasite that requires iron (Fe for its metabolic function and virulence. Bovine lactoferrin (B-Lf and its peptides can be found in the digestive tract after dairy products are ingested. The aim of this study was to compare virulent trophozoites recently isolated from hamster liver abscesses with nonvirulent trophozoites maintained for more than 30 years in cultures in vitro regarding their interaction with iron-charged B-Lf (B-holo-Lf. We performed growth kinetics analyses of trophozoites in B-holo-Lf and throughout several consecutive transfers. The virulent parasites showed higher growth and tolerance to iron than nonvirulent parasites. Both amoeba variants specifically bound B-holo-Lf with a similar Kd. However, averages of 9.45 × 105 and 6.65 × 106 binding sites/cell were found for B-holo-Lf in nonvirulent and virulent amoebae, respectively. Virulent amoebae bound more efficiently to human and bovine holo-Lf, human holo-transferrin, and human and bovine hemoglobin than nonvirulent amoebae. Virulent amoebae showed two types of B-holo-Lf binding proteins. Although both amoebae endocytosed this glycoprotein through clathrin-coated vesicles, the virulent amoebae also endocytosed B-holo-Lf through a cholesterol-dependent mechanism. Both amoeba variants secreted cysteine proteases cleaving B-holo-Lf. These data demonstrate that the B-Lf endocytosis is more efficient in virulent amoebae.

Binding and Endocytosis of Bovine Hololactoferrin by the Parasite Entamoeba histolytica.

Science.gov (United States)

Ortíz-Estrada, Guillermo; Calderón-Salinas, Víctor; Shibayama-Salas, Mineko; León-Sicairos, Nidia; de la Garza, Mireya

2015-01-01

Entamoeba histolytica is a human parasite that requires iron (Fe) for its metabolic function and virulence. Bovine lactoferrin (B-Lf) and its peptides can be found in the digestive tract after dairy products are ingested. The aim of this study was to compare virulent trophozoites recently isolated from hamster liver abscesses with nonvirulent trophozoites maintained for more than 30 years in cultures in vitro regarding their interaction with iron-charged B-Lf (B-holo-Lf). We performed growth kinetics analyses of trophozoites in B-holo-Lf and throughout several consecutive transfers. The virulent parasites showed higher growth and tolerance to iron than nonvirulent parasites. Both amoeba variants specifically bound B-holo-Lf with a similar K d . However, averages of 9.45 × 10(5) and 6.65 × 10(6) binding sites/cell were found for B-holo-Lf in nonvirulent and virulent amoebae, respectively. Virulent amoebae bound more efficiently to human and bovine holo-Lf, human holo-transferrin, and human and bovine hemoglobin than nonvirulent amoebae. Virulent amoebae showed two types of B-holo-Lf binding proteins. Although both amoebae endocytosed this glycoprotein through clathrin-coated vesicles, the virulent amoebae also endocytosed B-holo-Lf through a cholesterol-dependent mechanism. Both amoeba variants secreted cysteine proteases cleaving B-holo-Lf. These data demonstrate that the B-Lf endocytosis is more efficient in virulent amoebae.

Lactobacillus rhamnosus reduces parasite load on Toxocara canis experimental infection in mice, but has no effect on the parasite in vitro.

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Walcher, Débora Liliane; Cruz, Luis Augusto Xavier; de Lima Telmo, Paula; Martins, Lourdes Helena Rodrigues; da Costa de Avila, Luciana Farias; Berne, Maria Elisabeth Aires; Scaini, Carlos James

2018-02-01

Human toxocariasis is a neglected global parasitic zoonosis. The efficacy of drug treatment for this disease has been hindered by the biological complexity of the main etiological agent, the nematode Toxocara canis. Experimental studies have shown the potential of probiotics to promote a reduction in the parasite load of T. canis larvae. This study aimed to evaluate the effect of probiotic Lactobacillus rhamnosus ATCC 7469 on the parasite load of BALB/c mice with acute toxocariasis and evaluate the direct effect of this probiotic on T. canis larvae in vitro. In vivo administration of probiotics reduced the parasite load of T. canis larvae by 53.3% (p = 0.0018) during the early stage of infection in mice. However, when analyzed in vitro, it was observed that the probiotic did not present a deleterious effect on the larvae, as approximately 90% of these remained viable. These results demonstrate the potential of the probiotic L. rhamnosus in the reduction of T. canis larvae in BALB/c mice and suggest it could be used as an alternative means for the controlling of visceral toxocariasis. However, further studies are required to elucidate the mechanisms of action promoted by this probiotic.

Immunity to Visceral Leishmaniasis Using Genetically Defined Live-Attenuated Parasites

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Angamuthu Selvapandiyan

2012-01-01

Full Text Available Leishmaniasis is a protozoan parasitic disease endemic to the tropical and subtropical regions of the world, with three major clinical forms, self-healing cutaneous leishmaniasis (CL, mucocutaneous leishmaniasis (MCL, and visceral leishmaniasis (VL. Drug treatments are expensive and often result in the development of drug resistance. No vaccine is available against leishmaniasis. Subunit Leishmania vaccine immunization in animal models has shown some efficacy but little or none in humans. However, individuals who recover from natural infection are protected from reinfection and develop life-long protection, suggesting that infection may be a prerequisite for immunological memory. Thus, genetically altered live-attenuated parasites with controlled infectivity could achieve such memory. In this paper, we discuss development and characteristics of genetically altered, live-attenuated Leishmania donovani parasites and their possible use as vaccine candidates against VL. In addition, we discuss the challenges and other considerations in the use of live-attenuated parasites.

Ancylostoma ceylanicum, a re-emerging but neglected parasitic zoonosis.

Science.gov (United States)

Traub, Rebecca J

2013-11-01

Although Ancylostoma ceylanicum is known to be an endemic and widely distributed hookworm of dogs and cats in Asia, its contribution to human morbidity as a potentially zoonotic hookworm remains largely unexplored. Since its discovery by Lane (1913) as a 'new parasite' of humans a century ago, the hookworm has been regarded as a 'rare' and 'abnormal' parasite and largely overlooked in surveys of human parasites. Recent molecular-based surveys in Asia, however, have demonstrated that A. ceylanicum is the second most common hookworm species infecting humans, comprising between 6% and 23% of total patent hookworm infections. In experimentally induced infections, A. ceylanicum mimics the clinical picture produced by the anthroponotic hookworms of 'ground itch' and moderate to severe abdominal pain in the acute phase. Natural infections with A. ceylanicum in humans have been reported in almost all geographical areas in which the hookworm is known to be endemic in dogs and cats, however for the majority of reports, no clinical data are available. Much like the anthroponotic hookworm species, patent A. ceylanicum adults can isolate within the jejunum to produce chronic infections that on occasion, may occur in high enough burdens to produce anaemia. In addition, the hookworm can act much like Ancylostoma caninum and be found lower in the gastrointestinal tract leading to abdominal distension and pain, diarrhoea and occult blood in the faeces accompanied by peripheral eosinophilia. Whether A. ceylanicum is capable of producing both classical hookworm disease and evoking morbidity through an uncontrolled allergic response in some individuals remains unascertained. Future investigations combining the use of molecular diagnostic tools with clinical and pathological data will shed further light on its role as a human pathogen. The control of this zoonosis necessitates an integrated and inter-sectorial "One Health" approach be adopted in communities where large numbers of dogs

How have fisheries affected parasite communities?

Science.gov (United States)

Wood, Chelsea L; Lafferty, Kevin D

2015-01-01

To understand how fisheries affect parasites, we conducted a meta-analysis of studies that contrasted parasite assemblages in fished and unfished areas. Parasite diversity was lower in hosts from fished areas. Larger hosts had a greater abundance of parasites, suggesting that fishing might reduce the abundance of parasites by selectively removing the largest, most heavily parasitized individuals. After controlling for size, the effect of fishing on parasite abundance varied according to whether the host was fished and the parasite's life cycle. Parasites of unfished hosts were more likely to increase in abundance in response to fishing than were parasites of fished hosts, possibly due to compensatory increases in the abundance of unfished hosts. While complex life cycle parasites tended to decline in abundance in response to fishing, directly transmitted parasites tended to increase. Among complex life cycle parasites, those with fished hosts tended to decline in abundance in response to fishing, while those with unfished hosts tended to increase. However, among directly transmitted parasites, responses did not differ between parasites with and without fished hosts. This work suggests that parasite assemblages are likely to change substantially in composition in increasingly fished ecosystems, and that parasite life history and fishing status of the host are important in predicting the response of individual parasite species or groups to fishing.

Host and parasite morphology influence congruence between host and parasite phylogenies.

Science.gov (United States)

Sweet, Andrew D; Bush, Sarah E; Gustafsson, Daniel R; Allen, Julie M; DiBlasi, Emily; Skeen, Heather R; Weckstein, Jason D; Johnson, Kevin P

2018-03-23

Comparisons of host and parasite phylogenies often show varying degrees of phylogenetic congruence. However, few studies have rigorously explored the factors driving this variation. Multiple factors such as host or parasite morphology may govern the degree of phylogenetic congruence. An ideal analysis for understanding the factors correlated with congruence would focus on a diverse host-parasite system for increased variation and statistical power. In this study, we focused on the Brueelia-complex, a diverse and widespread group of feather lice that primarily parasitise songbirds. We generated a molecular phylogeny of the lice and compared this tree with a phylogeny of their avian hosts. We also tested for the contribution of each host-parasite association to the overall congruence. The two trees overall were significantly congruent, but the contribution of individual associations to this congruence varied. To understand this variation, we developed a novel approach to test whether host, parasite or biogeographic factors were statistically associated with patterns of congruence. Both host plumage dimorphism and parasite ecomorphology were associated with patterns of congruence, whereas host body size, other plumage traits and biogeography were not. Our results lay the framework for future studies to further elucidate how these factors influence the process of host-parasite coevolution. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

Parasites as prey in aquatic food webs: implications for predator infection and parasite transmission

NARCIS (Netherlands)

Thieltges, D.W.; Amundsen, P.-A.; Hechinger, R.F.; Johnson, P.T.J.; Lafferty, K.D.; Mouritsen, K.N.; Preston, D.L.; Reise, K.; Zander, C.D.; Poulin, R.

2013-01-01

While the recent inclusion of parasites into food-web studies has highlighted the role of parasites as consumers, there is accumulating evidence that parasites can also serve as prey for predators. Here we investigated empirical patterns of predation on parasites and their relationships with

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa)

OpenAIRE

Benamrouz S.; Conseil V.; Creusy C.; Calderon E.; Dei-Cas E.; Certad G.

2012-01-01

The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozo...

Gastrointestinal parasites of cats in Brazil: frequency and zoonotic risk

Directory of Open Access Journals (Sweden)

Maria Fernanda Melo Monteiro

2016-01-01

Full Text Available Abstract Gastrointestinal helminths are considered to be the most common parasites affecting cats worldwide. Correct diagnosis of these parasites in animals living in urban areas is pivotal, especially considering the zoonotic potential of some species (e.g. Ancylostoma sp. and Toxocarasp.. In this study, a copromicroscopic survey was conducted using fecal samples (n = 173 from domestic cats living in the northeastern region of Brazil. Samples were examined through the FLOTAC technique and the overall results showed positivity of 65.31% (113/173 among the samples analyzed. Coinfections were observed in 46.01% (52/113 of the positive samples. The most common parasites detected were Ancylostoma sp., Toxocara cati, Strongyloides stercoralis,Trichuris sp., Dipylidium caninum andCystoisospora sp. From an epidemiological point of view, these findings are important, especially considering that zoonotic parasites (e.g. Ancylostoma sp. and Toxocara sp. were the nematodes most frequently diagnosed in this study. Therefore, the human population living in close contact with cats is at risk of infection caused by the zoonotic helminths of these animals. In addition, for the first time the FLOTAC has been used to diagnosing gastrointestinal parasites of cats in Brazil.

Gastrointestinal parasites of cats in Brazil: frequency and zoonotic risk.