The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

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Arnaiz, Olivier; Mathy, Nathalie; Baudry, Céline; Malinsky, Sophie; Aury, Jean-Marc; Denby Wilkes, Cyril; Garnier, Olivier; Labadie, Karine; Lauderdale, Benjamin E; Le Mouël, Anne; Marmignon, Antoine; Nowacki, Mariusz; Poulain, Julie; Prajer, Malgorzata; Wincker, Patrick; Meyer, Eric; Duharcourt, Sandra; Duret, Laurent; Bétermier, Mireille; Sperling, Linda

2012-01-01

Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES) from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a fraction of the

The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

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Olivier Arnaiz

Full Text Available Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a

Disseminated neurocysticercosis presenting as affective mood disorder with chronic tension type headache

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Krishnarpan Chatterjee

2013-01-01

Full Text Available Neurocysticercosis is a common parasitic infection in India presenting usually with seizues, headache, focal neurological deficits. Neurocysticercosis presenting as a psychiatric illness is rare. Disseminated cysticercosis with involvement of central nervous system and head and neck muscles is rare even in endemic areas. We present a case of disseminated cysticercosis, which presented with chronic tension type headache and affective mood disorder. Treatment with cysticidal drugs led to complete remission of psychiatric complaints. In endemic areas history suggestive of mood disorder should not be used as supportive evidence of a primary headache syndome like tension type headche without ruling out secondary causes. Making an early diagnosis can prevent morbidity.

Sarcocystis in Biology of Foodborne Parasites CRC Press

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People can contract infections by consuming beef infected with Sarcocystis hominis or pork infected with Sarcocystis suihominis. Proper cooking can eliminate this foodborne risk of infection. Here, the biology of such parasites is thoroughly reviewed, focusing on the epidemiology, diagnosis, treat...

Longitudinal study of parasite-induced mortality of a long-lived host: the importance of exposure to non-parasitic stressors.

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Chin, Hilary M-H; Luong, Lien T; Shostak, Allen W

2017-12-01

Hosts face mortality from parasitic and environmental stressors, but interactions of parasitism with other stressors are not well understood, particularly for long-lived hosts. We monitored survival of flour beetles (Tribolium confusum) in a longitudinal design incorporating cestode (Hymenolepis diminuta) infection, starvation and exposure to the pesticide diatomaceous earth (DE). We found that cestode cysticercoids exhibit increasing morphological damage and decreasing ability to excyst over time, but were never eliminated from the host. In the presence of even mild environmental stressors, host lifespan was reduced sufficiently that extensive degradation of cysticercoids was never realized. Median host lifespan was 200 days in the absence of stressors, and 3-197 days with parasitism, starvation and/or DE. Early survival of parasitized hosts was higher relative to controls in the presence of intermediate concentrations of DE, but reduced under all other conditions tested. Parasitism increased host mortality in the presence of other stressors at times when parasitism alone did not cause mortality, consistent with an interpretation of synergy. Environmental stressors modified the parasite numbers needed to reveal intensity-dependent host mortality, but only rarely masked intensity dependence. The longitudinal approach produced observations that would have been overlooked or misinterpreted if survival had only been monitored at a single time point.

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

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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.

Fighting fish parasites with photodynamically active chlorophyllin.

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Häder, D-P; Schmidl, J; Hilbig, R; Oberle, M; Wedekind, H; Richter, P

2016-06-01

Water-soluble chlorophyll (chlorophyllin) was used in a phototoxic reaction against a number of fish ectoparasites such as Ichtyobodo, Dactylogyrus, Trichodina, and Argulus. Chlorophyllin is applied to the water at concentrations of several micrograms per milliliter for a predefined incubation time, and afterwards, the parasites are exposed to simulated solar radiation. Application in the dark caused only little damage to the parasites; likewise, light exposure without the addition of the photosensitizer was ineffective. In Ichthyobodo, 2 μg/mL proved sufficient with subsequent simulated solar radiation to almost quantitatively kill the parasites, while in Dactylogyrus, a concentration of about 6 μg/mL was necessary. The LD50 value for this parasite was 1.02 μg/mL. Trichodina could be almost completely eliminated at 2 μg/mL. Only in the parasitic crustacean Argulus, no killing could be achieved by a photodynamic reaction using chlorophyllin. Chlorophyllin is non-toxic, biodegradable, and can be produced at low cost. Therefore, we propose that chlorophyllin (or other photodynamic substances) are a possible effective countermeasure against several ectoparasites in ponds and aquaculture since chemical remedies are either forbidden and/or ineffective.

Local population structure of Plasmodium: impact on malaria control and elimination

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Chenet Stella M

2012-12-01

Full Text Available Abstract Background Regardless of the growing interest in detecting population structures in malarial parasites, there have been limited discussions on how to use this concept in control programmes. In such context, the effects of the parasite population structures will depend on interventions’ spatial or temporal scales. This investigation explores the problem of identifying genetic markers, in this case microsatellites, to unveil Plasmodium genetic structures that could affect decisions in the context of elimination. The study was performed in a low-transmission area, which offers a good proxy to better understand problems associated with surveillance at the final stages of malaria elimination. Methods Plasmodium vivax samples collected in Tumeremo, Venezuela, between March 2003 and November 2004 were analysed. Since Plasmodium falciparum also circulates in many low endemic areas, P. falciparum samples from the same locality and time period were included for comparison. Plasmodium vivax samples were assayed for an original set of 25 microsatellites and P. falciparum samples were assayed for 12 microsatellites. Results Not all microsatellite loci assayed offered reliable local data. A complex temporal-cluster dynamics is found in both P. vivax and P. falciparum. Such dynamics affect the numbers and the type of microsatellites required for identifying individual parasites or parasite clusters when performing cross-sectional studies. The minimum number of microsatellites required to differentiate circulating P. vivax clusters differs from the minimum number of hyper-variable microsatellites required to distinguish individuals within these clusters. Regardless the extended number of microsatellites used in P. vivax, it was not possible to separate all individual infections. Conclusions Molecular surveillance has great potential; however, it requires preliminary local studies in order to properly interpret the emerging patterns in the context of

Evaluation of five treatments to control intestinal parasites in sheep in Ayapango, state of Mexico

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Rafael Heredia

2016-11-01

Full Text Available Aim: Intestinal parasites are one of the most common problems in sheep production systems. However, the strategies used to eliminate these parasites have not yielded satisfactory results. Therefore, the aim of this study was to determine the effect of five anthelmintics (with different active ingredients on the parasite load in sheep. Materials and Methods: In this study, 107 Rambouillet breed sheep were randomly assigned to five groups. Next, fecal samples were taken directly from the rectum and sent to the laboratory for analysis. We then dewormed each group of sheep using different anthelmintic products: Ivermectin 1%/clorsulon 10%, levamisole 12%, closantel sodium 5%, ivermectin 10%, and closantel 5%/albendazole 3.75% with a dosage corresponding to each sheep. At 15 days post-treatment, we took fecal samples and performed a coproparasitoscopic study, using the Faust flotation technique to assess the presence or absence of parasite eggs and the McMaster technique to quantify eggs. Results: Ivermectin/clorsulon was more effective in eliminating parasites than other anthelmintics used, especially in Haemonchus spp. Conclusion: The results of this study indicate that using ivermectin/clorsulon decreases the number of eggs in feces and is one alternative in controlling parasites in sheep, leading to a reduction in the incidence of health problems, and consequently, improved productivity.

Modulation of Dendritic Cell Responses by Parasites: A Common Strategy to Survive

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César A. Terrazas

2010-01-01

Full Text Available Parasitic infections are one of the most important causes of morbidity and mortality in our planet and the immune responses triggered by these organisms are critical to determine their outcome. Dendritic cells are key elements for the development of immunity against parasites; they control the responses required to eliminate these pathogens while maintaining host homeostasis. However, there is evidence showing that parasites can influence and regulate dendritic cell function in order to promote a more permissive environment for their survival. In this review we will focus on the strategies protozoan and helminth parasites have developed to interfere with dendritic cell activities as well as in the possible mechanisms involved.

A case of disseminated hydatid disease by surgery involving multiple organs

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Asli Tanrivermis Sayit

2014-09-01

Full Text Available Hydatid disease is the most common parasitic infection in the world, and is caused by the parasite Echinococcus granulosus. The most common site of this disease is the liver (75%, followed by the lungs, kidney, bones, and brain. Multiple abdominal organ and peritoneal involvement can also be seen in some cases. The dissemination of hydatid cyst disease can develop spontaneously or secondary to trauma or surgery. Here, we present the case of a 69-year-old man with multiple cyst hydatidosis, who underwent surgery for acute appendicitis approximately 20 years previously. Computed tomography of the abdomen shows the multiple active and inactive cystic lesions in the liver, spleen, right kidney, and mesentery. This patient required surgery several times, as well as medical treatment, after the rupture of a mesenteric hydatid cyst during the appendectomy. Combined anthelmintic treatment was recommended to the patient who refused further surgical treatment.

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Tóth, Peter; Undas, Anna K.; Verstappen, Francel; Bouwmeester, Harro

2016-01-01

The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae), are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs), consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae. PMID:27014329

Host responses to interspecific brood parasitism: a by-product of adaptations to conspecific parasitism?

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Samas, Peter; Hauber, Mark E; Cassey, Phillip; Grim, Tomas

2014-01-01

Why have birds evolved the ability to reject eggs? Typically, foreign egg discrimination is interpreted as evidence that interspecific brood parasitism (IP) has selected for the host's ability to recognize and eliminate foreign eggs. Fewer studies explore the alternative hypothesis that rejection of interspecific eggs is a by-product of host defenses, evolved against conspecific parasitism (CP). We performed a large scale study with replication across taxa (two congeneric Turdus thrushes), space (populations), time (breeding seasons), and treatments (three types of experimental eggs), using a consistent design of egg rejection experiments (n = 1057 nests; including controls), in areas with potential IP either present (Europe; native populations) or absent (New Zealand; introduced populations). These comparisons benefited from the known length of allopatry (one and a half centuries), with no gene flow between native and introduced populations, which is rarely available in host-parasite systems. Hosts rejected CP at unusually high rates for passerines (up to 60%). CP rejection rates were higher in populations with higher conspecific breeding densities and no risks of IP, supporting the CP hypothesis. IP rejection rates did not covary geographically with IP risk, contradicting the IP hypothesis. High egg rejection rates were maintained in the relatively long-term isolation from IP despite non-trivial rejection costs and errors. These egg rejection patterns, combined with recent findings that these thrushes are currently unsuitable hosts of the obligate parasitic common cuckoo (Cuculus canorus), are in agreement with the hypothesis that the rejection of IP is a by-product of fine-tuned egg discrimination evolved due to CP. Our study highlights the importance of considering both IP and CP simultaneously as potential drivers in the evolution of egg discrimination, and illustrates how populations introduced to novel ecological contexts can provide critical insights

Disseminated sporotrichosis

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Romero-Cabello, Raúl; Bonifaz, Alexandro; Romero-Feregrino, Raúl; Sánchez, Carlos Javier; Linares, Yancy; Zavala, Jorge Tay; Romero, Leticia Calderón; Romero-Feregrino, Rodrigo; Vega, José T Sánchez

2011-01-01

Sporotrichosis is a subacute or chronic infection caused by Sporothrix schenckii. It is a primary cutaneous infection and it has different clinical forms: disseminated by lymphatic vessels (75%), localised cutaneous form (20%), disseminated cutaneous and extracuteus rarely. The systemic disseminated sporotrichosis is considered a severe opportunistic infection. The best diagnostic test is the culture. The authors report a case of a 36-year-old man, originally from Puebla, Mexico, with a diagnosis of disseminated sporotrichosis. Differential diagnosis with other pathologies includes leishmaniasis, chromoblastomycosis, tuberculosis verrucose and lymphangitis. The development of unusual presentations in immunocompromised patients has been reported. PMID:22700076

Novel molecular diagnostic tools for malaria elimination: a review of options from the point of view of high-throughput and applicability in resource limited settings.

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Britton, Sumudu; Cheng, Qin; McCarthy, James S

2016-02-16

As malaria transmission continues to decrease, an increasing number of countries will enter pre-elimination and elimination. To interrupt transmission, changes in control strategies are likely to require more accurate identification of all carriers of Plasmodium parasites, both symptomatic and asymptomatic, using diagnostic tools that are highly sensitive, high throughput and with fast turnaround times preferably performed in local health service settings. Currently available immunochromatographic lateral flow rapid diagnostic tests and field microscopy are unlikely to consistently detect infections at parasite densities less than 100 parasites/µL making them insufficiently sensitive for detecting all carriers. Molecular diagnostic platforms, such as PCR and LAMP, are currently available in reference laboratories, but at a cost both financially and in turnaround time. This review describes the recent progress in developing molecular diagnostic tools in terms of their capacity for high throughput and potential for performance in non-reference laboratories for malaria elimination.

Floral Volatiles in Parasitic Plants of the Orobanchaceae. Ecological and Taxonomic Implications

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Peter eTóth

2016-03-01

Full Text Available The holoparasitic broomrapes, Orobanche spp. and Phelipanche spp. (Orobanchaceae, are root parasites that completely depend on a host plant for survival and reproduction. There is considerable controversy on the taxonomy of this biologically and agronomically important family. Flowers of over 25 parasitic Orobanchaceae and a number of close, parasitic and non-parasitic, relatives emitted a complex blend of volatile organic compounds (VOCs, consisting of over 130 VOCs per species. Floral VOC blend-based phylogeny supported the known taxonomy in internal taxonomic grouping of genus and eliminated the uncertainty in some taxonomical groups. Moreover, phylogenetic analysis suggested separation of the broomrapes into two main groups parasitizing annual and perennial hosts, and for the annual hosts, into weedy and non-weedy broomrapes. We conclude that floral VOCs are a significant tool in species identification and possibly even in defining new species and can help to improve controversial taxonomy in the Orobanchaceae.

Genetic variability and population structure of Plasmodium falciparum parasite populations from different malaria ecological regions of Kenya.

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Ingasia, Luicer A; Cheruiyot, Jelagat; Okoth, Sheila Akinyi; Andagalu, Ben; Kamau, Edwin

2016-04-01

Transmission intensity, movement of human and vector hosts, biogeographical features, and malaria control measures are some of the important factors that determine Plasmodium falciparum parasite genetic variability and population structure. Kenya has different malaria ecologies which might require different disease intervention methods. Refined parasite population genetic studies are critical for informing malaria control and elimination strategies. This study describes the genetic diversity and population structure of P. falciparum parasites from the different malaria ecological zones in Kenya. Twelve multi-locus microsatellite (MS) loci previously described were genotyped in 225 P. falciparum isolates collected between 2012 and 2013 from five sites; three in lowland endemic regions (Kisumu, Kombewa, and Malindi) and two in highland, epidemic regions (Kisii and Kericho). Parasites from the lowland endemic and highland epidemic regions of western Kenya had high genetic diversity compared to coastal lowland endemic region of Kenya [Malindi]. The Kenyan parasites had a mean genetic differentiation index (FST) of 0.072 (p=0.011). The multi-locus genetic analysis of the 12 MS revealed all the parasites had unique haplotypes. Significant linkage disequilibrium (LD) was observed in all the five parasite populations. Kisumu had the most significant index of association values (0.16; pKenya after introduction of the artemether-lumefantrine is important in refining the spread of drug resistant strains and malaria transmission for more effective control and eventual elimination of malaria in Kenya. Copyright © 2015. Published by Elsevier B.V.

Beyond the reproductive effect of sex steroids: their role during immunity to helminth parasite infections.

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Hernández-Bello, R; Nava-Castro, K; Muñiz-Hernández, S; Nava-Luna, P; Trejo-Sánchez, Itztli; Tiempos-Guzmán, N; Mendoza-Rodríguez, Y; Morales-Montor, J

2012-10-01

During the helminth infections, the immune system tends to be modulated by host's sex hormones. Actually, many studies show the reciprocal relationship between sex steroids, the immune system and the elimination or establishment of helminth parasites. Is well known that innate immune response determines the type of adaptive immune response, so the effects in the innate immune response by hormones may affect subsequent adaptive immunity. The sex steroids as estrogens, progesterone and testosterone regulate growth, differentiation, survival and function of many cell types that could be involved in process like homeostasis and immunity, but also have a direct effect on the helminthes, that may probably be mediated by specific receptors on these parasites. Sex steroids, parasites and immunity are closely connected, and their interconnection is involved in the maintenance of elimination or establishment of helminthes in an immunocompetent host. For that reason, understanding the action's mechanisms of sex steroids on immune cells and its direct effect on helminth parasites is important for further progress in the development of novel therapies for chronic helminth diseases associated to immune dysregulation. In this review, we will describe the effects of sex steroids on the immune response during helminth infections as well as the direct effect in these parasites, and the possible implications of these effects on the incidence of several helminth infections.

Understanding the population genetics of Plasmodium vivax is essential for malaria control and elimination

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Arnott Alicia

2012-01-01

Full Text Available Abstract Traditionally, infection with Plasmodium vivax was thought to be benign and self-limiting, however, recent evidence has demonstrated that infection with P. vivax can also result in severe illness and death. Research into P. vivax has been relatively neglected and much remains unknown regarding the biology, pathogenesis and epidemiology of this parasite. One of the fundamental factors governing transmission and immunity is parasite diversity. An understanding of parasite population genetic structure is necessary to understand the epidemiology, diversity, distribution and dynamics of natural P. vivax populations. In addition, studying the population structure of genes under immune selection also enables investigation of the dynamic interplay between transmission and immunity, which is crucial for vaccine development. A lack of knowledge regarding the transmission and spread of P. vivax has been particularly highlighted in areas where malaria control and elimination programmes have made progress in reducing the burden of Plasmodium falciparum, yet P. vivax remains as a substantial obstacle. With malaria elimination back on the global agenda, mapping of global and local P. vivax population structure is essential prior to establishing goals for elimination and the roll-out of interventions. A detailed knowledge of the spatial distribution, transmission and clinical burden of P. vivax is required to act as a benchmark against which control targets can be set and measured. This paper presents an overview of what is known and what is yet to be fully understood regarding P. vivax population genetics, as well as the importance and application of P. vivax population genetics studies.

Eliminating the Neglected Tropical Diseases: Translational Science and New Technologies.

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Peter J Hotez

2016-03-01

Full Text Available Today, the World Health Organization recognizes 17 major parasitic and related infections as the neglected tropical diseases (NTDs. Despite recent gains in the understanding of the nature and prevalence of NTDs, as well as successes in recent scaled-up preventive chemotherapy strategies and other health interventions, the NTDs continue to rank among the world's greatest global health problems. For virtually all of the NTDs (including those slated for elimination under the auspices of a 2012 London Declaration for NTDs and a 2013 World Health Assembly resolution [WHA 66.12], additional control mechanisms and tools are needed, including new NTD drugs, vaccines, diagnostics, and vector control agents and strategies. Elimination will not be possible without these new tools. Here we summarize some of the key challenges in translational science to develop and introduce these new technologies in order to ensure success in global NTD elimination efforts.

No Evidence of Delayed Parasite Clearance after Oral Artesunate Treatment of Uncomplicated Falciparum Malaria in Mali

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Maiga, Amelia W.; Fofana, Bakary; Sagara, Issaka; Dembele, Demba; Dara, Antoine; Traore, Oumar Bila; Toure, Sekou; Sanogo, Kassim; Dama, Souleymane; Sidibe, Bakary; Kone, Aminatou; Thera, Mahamadou A.; Plowe, Christopher V.; Doumbo, Ogobara K.; Djimde, Abdoulaye A.

2012-01-01

Plasmodium falciparum resistance to artemisinins by delayed parasite clearance is present in Southeast Asia. Scant data on parasite clearance after artemisinins are available from Africa, where transmission is high, burden is greatest, and artemisinin use is being scaled up. Children 1–10 years of age with uncomplicated malaria were treated with 7 days of artesunate and followed for 28 days. Blood smears were done every 8 hours until negative by light microscopy. Results were compared with a similar study conducted in the same village in 2002–2004. The polymerase chain reaction-corrected cure rate was 100%, identical to 2002–2004. By 24 hours after treatment initiation, 37.0% of participants had cleared parasitemia, compared with 31.9% in 2002–2004 (P = 0.5). The median parasite clearance time was 32 hours. Only one participant still had parasites at 48 hours and no participant presented parasitemia at 72 hours. Artesunate was highly efficacious, with no evidence of delayed parasite clearance. We provide baseline surveillance data for the emergence or dissemination of P. falciparum resistance in sub-Saharan Africa. PMID:22764287

Control of human parasitic diseases: Context and overview.

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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

Medically Important Parasites Carried by Cockroaches in Melong Subdivision, Littoral, Cameroon

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R. J. Atiokeng Tatang

2017-01-01

Full Text Available Cockroaches have been recognized as mechanical vectors of pathogens that can infest humans or animals. A total of 844 adult cockroaches (436 males and 408 females were caught. In the laboratory, cockroaches were first washed in saturated salt solution to remove ectoparasites and then rinsed with 70% alcohol, dried, and dissected for endoparasites. An overall transport rate of 47.39% was recorded. Six genera of parasites were identified. These were Ascaris (33.76%, Trichuris (11.97%, Capillaria (6.16%, Toxocara (4.86%, Hook Worm (4.86%, and Eimeria (2.73%. The parasites were more recorded on the external surface (54.27% of cockroaches than in the internal surface (GIT, 38.51%. The same tendency was obtained between sexes with female cockroaches having a higher transport rate (36.69%. Cockroaches caught in toilets carried more parasites (31.99% as compared to those from kitchens (22.63% and houses (11.14%. Almost all encountered parasites were recognized as responsible of zoonosis and they can be consequently released in nature by hosts and easily disseminated by cockroaches as mechanical vectors. Sanitary education, reenforcement of worms’ eradication programs, and the fight against these insects remain a necessity in the Mélong Subdivision.

Dissemination Strategy Report

DEFF Research Database (Denmark)

Badger, Merete; Kjems, Jørgen; Farinetti, Laura

This report describes the dissemination and exploitation strategy for project Virtual Campus Hub (EU FP7 contract RI-283746). The project duration is October 2011-13 and the dissemination and exploitation plan will be revised continuously during the project’s lifecycle.......This report describes the dissemination and exploitation strategy for project Virtual Campus Hub (EU FP7 contract RI-283746). The project duration is October 2011-13 and the dissemination and exploitation plan will be revised continuously during the project’s lifecycle....

Factors Associated with Gastrointestinal Parasitic Infections among Young Population in Northeast Brazil

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Juliana Vasconcelos Lyra da Silva

2016-01-01

Full Text Available Background. Intestinal parasitic infections constitute a major public health problem that is frequently associated with poverty, inadequate sanitation, and the nutritional status of the population. Objective. The aim of the present study is to investigate the possible association of parasitic infections, sanitary conditions, hygiene practices, and the nutritional and socioeconomic status of a poor youth population. Methods. A cross-sectional study was conducted with 367 children and adolescents inhabiting a substandard settlement in the urban area of Maceió (Alagoas State, Brazil. Data collection included socioeconomic status, anthropometric measurements, fecal sample examinations, and laboratory blood analysis. The identification of factors associated with gastrointestinal parasitic infections was undertaken through bi- and multivariate analyses. Results. Stool sample analysis obtained from 300 individuals revealed that 204 (68% were infected with at least one parasite species and of these 130 (63.7% were polyparasitized. No significant associations were identified between low height for age (stunted, parasitic infections, and polyparasitism. There was also no association between family income and parasitosis. However, low socioeconomic status proved to be a potential risk factor for parasitic infections. Conclusion. Actions must be taken to improve sanitation, housing, and environmental conditions in order to eliminate the risk factors for parasitic infections, and thereby guarantee a better quality of life for this population.

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

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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.

Parasites of the Giant Panda: A Risk Factor in the Conservation of a Species.

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Wang, Tao; Xie, Yue; Zheng, Youle; Wang, Chengdong; Li, Desheng; Koehler, Anson V; Gasser, Robin B

2018-01-01

The giant panda, with an estimated population size of 2239 in the world (in 2015), is a global symbol of wildlife conservation that is threatened by habitat loss, poor reproduction and limited resistance to some infectious diseases. Of these factors, some diseases caused by parasites are considered as the foremost threat to its conservation. However, there is surprisingly little published information on the parasites of the giant panda, most of which has been disseminated in the Chinese literature. Herein, we review all peer-reviewed publications (in English or Chinese language) and governmental documents for information on parasites of the giant pandas, with an emphasis on the intestinal nematode Baylisascaris schroederi (McIntosh, 1939) as it dominates published literature. The purpose of this chapter is to: (i) review the parasites recorded in the giant panda and describe what is known about their biology; (ii) discuss key aspects of the pathogenesis, diagnosis, treatment and control of key parasites that are reported to cause clinical problems and (iii) conclude by making some suggestions for future research. This chapter shows that we are only just 'scratching the surface' when it comes to parasites and parasitological research of the giant panda. Clearly, there needs to be a concerted research effort to support the conservation of this iconic species. © 2018 Elsevier Ltd All rights reserved.

Fasciola hepatica infection and association with gastrointestinal parasites in Creole goats from western Argentina.

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Cuervo, Pablo; Sidoti, Laura; Fantozzi, Cecilia; Neira, Gisela; Gerbeno, Leticia; Mera y Sierra, Roberto

2013-01-01

Goats, called “the cow of the poor”, are the livestock species with the most significant population growth worldwide in recent years. Gastrointestinal parasitism constitutes one of the main constraints to its outdoor and extensive breeding in temperate and tropical countries. Despite a Creole goat population of nearly 4 million heads, local reports on parasitological prevalence are scarce, and while Fasciola hepatica infection is spread all over Argentina, the goat is usually neglected as a reservoir and economic losses are not considered. To evaluate gastrointestinal parasitism prevalence and associations between parasite genera and species, with emphasis on fascioliasis, Creole goats from the plateau and Andean regions from western Argentina were investigated by coprological techniques, and associations were statistically assessed. Eighty-five percent (85%) of the animals harbored one or more parasite types, while 46% showed mixed infections. Significant positive associations between F. hepatica + Strongyle eggs, Eimeria sp. + Nematodirus sp. and Nematodirus sp. + Trichuris ovis were detected. Further studies are required to define the causality of these associations and their relevance in epidemiology. F. hepatica is rarely considered as goat parasite in the country, but a 33% prevalence poses an interrogation on the role goats play on the transmission and dissemination of this zoonotic trematode.

Early diagnosis and successful treatment of disseminated toxoplasmosis after cord blood transplantation.

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Kurihara, Taro; Sumi, Masahiko; Kaiume, Hiroko; Takeda, Wataru; Kirihara, Takehiko; Sato, Keijiro; Ueki, Toshimitsu; Hiroshima, Yuki; Ueno, Mayumi; Ichikawa, Naoaki; Kaneko, Yumi; Hikosaka, Kenji; Norose, Kazumi; Kobayashi, Hikaru

2016-06-01

A 66-year-old woman with refractory angioimmunoblastic T-cell lymphoma underwent cord blood transplantation. Prior to transplantation, a serological test for Toxoplasma gondii-specific IgG antibodies was positive. On day 96, she exhibited fever and dry cough. Chest CT showed diffuse centrilobular ground glass opacities in both lungs. The reactivation of T. gondii was identified by the presence of parasite DNA in peripheral blood and bronchoalveolar lavage fluid. Moreover, brain MRI revealed a space occupying lesion in the right occipital lobe. Therefore, disseminated toxoplasmosis was diagnosed. She received pyrimethamine and sulfadiazine from day 99. The lung and brain lesions both showed improvement but the PCR assay for T. gondii DNA in peripheral blood was positive on day 133. On day 146, she developed blurred vision and reduced visual acuity, and a tentative diagnosis of toxoplasmic retinochoroiditis was made based on ophthalmic examination results. As agranulocytosis developed on day 158, we decided to discontinue pyrimethamine and sulfadiazine and the treatment was thus switched to atovaquone. Moreover, we added spiramycin to atovaquone therapy from day 174, and her ocular condition gradually improved. In general, the prognosis of disseminated toxoplasmosis after hematopoietic stem cell transplantation (HSCT) is extremely poor. However, early diagnosis and treatment may contribute to improvement of the fundamentally dismal prognosis of disseminated toxoplasmosis after HSCT.

Introduction to the special section on dissemination: dissemination research and research dissemination: how can we close the gap?

Science.gov (United States)

Kerner, Jon; Rimer, Barbara; Emmons, Karen

2005-09-01

One of the greatest challenges facing health promotion and disease prevention is translating research findings into evidence-based public health and clinical practices that are actively disseminated and widely adopted. Despite the tremendous strides made in developing effective disease prevention and control programs, there has been little study of effective dissemination of evidence-based programs to and adoption by community, public health, and clinical practice settings. This special section provides a venue in which to highlight exemplary dissemination research efforts while also identifying limitations in research to date and framing important future research questions. This issue establishes a resource for investigators interested in dissemination research, with relevance to health psychology. In this sense, it can serve as a benchmark by which to examine subsequent progress. The 6 articles reflect the state of the science in dissemination research for the promotion and adoption of health behavior change interventions. (c) 2005 APA, all rights reserved

A case of disseminated central nervous system sparganosis.

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Noiphithak, Raywat; Doungprasert, Gahn

2016-01-01

Sparganosis is a very rare parasitic infection in various organs caused by the larvae of tapeworms called spargana. The larva usually lodges in the central nervous system (CNS) and the orbit. However, lumbar spinal canal involvement, as noted in the present case, is extremely rare. We report a rare case of disseminated CNS sparganosis involving the brain and spinal canal and review the literature. A 54-year-old man presented with progressive low back pain and neurological deficit at the lumbosacral level for 2 months. Imaging indicated arachnoiditis and an abnormal lesion at the L4-5 vertebral level. The patient underwent laminectomy of the L4-5 with lesionectomy and lysis of adhesions between the nerve roots. Microscopic examination indicated sparganum infection. Further brain imaging revealed evidence of chronic inflammation in the left parieto-occipital area without evidence of live parasites. In addition, an ophthalmologist reported a nonactive lesion in the right conjunctiva. The patient recovered well after surgery, although he had residual back pain and bladder dysfunction probably due to severe adhesion of the lumbosacral nerve roots. CNS sparganosis can cause various neurological symptoms similar to those of other CNS infections. A preoperative enzyme-linked immunosorbent assay is helpful for diagnosis, especially in endemic areas. Surgical removal of the worm remains the treatment of choice.

Control of parasites in cultured marine finfishes in Southeast Asia--an overview.

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Seng, L T

1997-10-01

Mariculture in Southeast Asia began in the 1970s and expanded rapidly during the 1980s, with the commercial hatchery production of the seabass Lates calcarifer. Other important cultured species were Epinephelus coioides, Epinephelus malabaricus, Lutjanus johni, and Lutjanus argentimaculatus. Intensification in the polyculture of these species and the large-scale international movement of fingerlings or juveniles, as well as the rapid expansion and concentration of fish farms, have caused severe problems resulting from parasitic infections. Infections in maricultured fish are predominantly caused by monoxenous parasites, in particular the capsalid and diplectanid monogeneans. Heteroxenous blood parasites also successfully maintained transmission in the culture system despite their requirement for an intermediate host. Prophylactic chemical treatments helped to reduce parasitic infection but did not eliminate them and once introduced into the floating netcage culture system, these parasites managed to maintain their transmission successfully. Despite the current lack of information regarding the biology of many parasites affecting cultured marine fishes, it nevertheless is possible to develop methodologies to produce an integrated health management system specifically designed to the needs of the mariculture practiced in the Southeast Asian region. This system is important and should include a sequence of prophylaxes, adequate nutrition, sanitation, immunization and an effective system of marketing for farmed fishes.

A Plasmodium falciparum screening assay for anti-gametocyte drugs based on parasite lactate dehydrogenase detection

NARCIS (Netherlands)

D'Alessandro, S.; Silvestrini, F.; Dechering, K.; Corbett, Y.; Parapini, S.; Timmerman, M.; Galastri, L.; Basilico, N.; Sauerwein, R.; Alano, P.; Taramelli, D.

2013-01-01

OBJECTIVES: Plasmodium gametocytes, responsible for malaria parasite transmission from humans to mosquitoes, represent a crucial target for new antimalarial drugs to achieve malaria elimination/eradication. We developed a novel colorimetric screening method for anti-gametocyte compounds based on the

Targeting Plasmodium PI(4)K to eliminate malaria

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McNamara, Case W.; Lee, Marcus C. S.; Lim, Chek Shik; Lim, Siau Hoi; Roland, Jason; Nagle, Advait; Simon, Oliver; Yeung, Bryan K. S.; Chatterjee, Arnab K.; McCormack, Susan L.; Manary, Micah J.; Zeeman, Anne-Marie; Dechering, Koen J.; Kumar, T. R. Santha; Henrich, Philipp P.; Gagaring, Kerstin; Ibanez, Maureen; Kato, Nobutaka; Kuhen, Kelli L.; Fischli, Christoph; Rottmann, Matthias; Plouffe, David M.; Bursulaya, Badry; Meister, Stephan; Rameh, Lucia; Trappe, Joerg; Haasen, Dorothea; Timmerman, Martijn; Sauerwein, Robert W.; Suwanarusk, Rossarin; Russell, Bruce; Renia, Laurent; Nosten, Francois; Tully, David C.; Kocken, Clemens H. M.; Glynne, Richard J.; Bodenreider, Christophe; Fidock, David A.; Diagana, Thierry T.; Winzeler, Elizabeth A.

2013-12-01

Achieving the goal of malaria elimination will depend on targeting Plasmodium pathways essential across all life stages. Here we identify a lipid kinase, phosphatidylinositol-4-OH kinase (PI(4)K), as the target of imidazopyrazines, a new antimalarial compound class that inhibits the intracellular development of multiple Plasmodium species at each stage of infection in the vertebrate host. Imidazopyrazines demonstrate potent preventive, therapeutic, and transmission-blocking activity in rodent malaria models, are active against blood-stage field isolates of the major human pathogens P. falciparum and P. vivax, and inhibit liver-stage hypnozoites in the simian parasite P. cynomolgi. We show that imidazopyrazines exert their effect through inhibitory interaction with the ATP-binding pocket of PI(4)K, altering the intracellular distribution of phosphatidylinositol-4-phosphate. Collectively, our data define PI(4)K as a key Plasmodium vulnerability, opening up new avenues of target-based discovery to identify drugs with an ideal activity profile for the prevention, treatment and elimination of malaria.

Use of Gamma Rays to Control of Internal Parasites and Pathogenic Bacteria in Silver side Fish (Bissaria)

International Nuclear Information System (INIS)

Shawki, H.A.; El-Hanafy, A.E.A.; Shagar, G.I.A.

2014-01-01

The usefulness of Gamma irradiation to control of internal parasites and pathogenic bacteria found in silver side fish (Atherina) (Bissaria) was investigated. The detected parasites and the prevalence were adult Trematode (37.5%); Cestodes (95%) and Nematode (22.5%) for control silver side fish. The counts of detected microorganisms, (Total bacterial count; Psychrophilic bacteria; Mold and yeast; E.coli and Staphyloccous aureus ) were 4.89 ; 2.30; 2.32; 2.31 and 2.04 log 10 cfu/g for control silver side fish, respectively. Applied irradiation doses reduce the infected rate by Trematode, Cestodes and Nematode, furthermore, gamma irradiation with different doses (0.5, 1, 2, 4 and 5 kGy) reduce the microorganisms count of silver side fish (Bissaria) samples and the rate of decrement increase with the dose increase. Total bacterial count was not detected by using dose 5 kGy while Psychrophilic bacteria were completely eliminated using dose 1 kGy. On the other hand mold and yeast; E.coli and Staph aureus in silver side fish samples were not detected after subjected to gamma irradiation with dose 4 kGy. The results suggest that the applied doses completely elimination different internal parasites and pathogenic bacteria found in silver side fish. Thus, it could be conclude that the irradiation dose of 4 kGy can be effectively applied to ensure the safety of internal parasites and pathogenic bacteria found in silver side fish (Atherina) (Bissaria) with regards to these harmful parasites and pathogenic bacteria

Optimising strategies for Plasmodium falciparum malaria elimination in Cambodia: primaquine, mass drug administration and artemisinin resistance.

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Richard J Maude

Full Text Available Malaria elimination requires a variety of approaches individually optimized for different transmission settings. A recent field study in an area of low seasonal transmission in South West Cambodia demonstrated dramatic reductions in malaria parasite prevalence following both mass drug administration (MDA and high treatment coverage of symptomatic patients with artemisinin-piperaquine plus primaquine. This study employed multiple combined strategies and it was unclear what contribution each made to the reductions in malaria.A mathematical model fitted to the trial results was used to assess the effects of the various components of these interventions, design optimal elimination strategies, and explore their interactions with artemisinin resistance, which has recently been discovered in Western Cambodia. The modelling indicated that most of the initial reduction of P. falciparum malaria resulted from MDA with artemisinin-piperaquine. The subsequent continued decline and near elimination resulted mainly from high coverage with artemisinin-piperaquine treatment. Both these strategies were more effective with the addition of primaquine. MDA with artemisinin combination therapy (ACT increased the proportion of artemisinin resistant infections, although much less than treatment of symptomatic cases with ACT, and this increase was slowed by adding primaquine. Artemisinin resistance reduced the effectiveness of interventions using ACT when the prevalence of resistance was very high. The main results were robust to assumptions about primaquine action, and immunity.The key messages of these modelling results for policy makers were: high coverage with ACT treatment can produce a long-term reduction in malaria whereas the impact of MDA is generally only short-term; primaquine enhances the effect of ACT in eliminating malaria and reduces the increase in proportion of artemisinin resistant infections; parasite prevalence is a better surveillance measure for

The effectiveness of riboflavin and ultraviolet light pathogen reduction technology in eliminating Trypanosoma cruzi from leukoreduced whole blood.

Science.gov (United States)

Jimenez-Marco, Teresa; Cancino-Faure, Beatriz; Girona-Llobera, Enrique; Alcover, M Magdalena; Riera, Cristina; Fisa, Roser

2017-06-01

The parasitic Chagas disease is caused by the protozoan Trypanosoma cruzi, which is mainly transmitted by insect vectors. Other infection routes, both in endemic and in nonendemic areas, include organ and marrow transplantation, congenital transmission, and blood transfusion. Asymptomatic chronic chagasic individuals may have a low and transient parasitemia in peripheral blood and, consequently, they can unknowingly transmit the disease via blood transfusion. Riboflavin and ultraviolet (UV) light pathogen reduction is a method to reduce pathogen transfusion transmission risk based on damage to the pathogen nucleic acids. In this study, we tested the effectiveness of this technology for the elimination of T. cruzi parasites in artificially contaminated whole blood units (WBUs) and thus for decreasing the risk of T. cruzi transfusion transmission. The contaminated WBUs were leukoreduced by filtration and treated with riboflavin and UV light. The level of pathogen reduction was quantified by a real-time polymerase chain reaction (qPCR) and a real-time reverse transcription-polymerase chain reaction (RT-qPCR) as a viability assay. The RNA (cDNA) quantification of the parasites showed a more than 99% reduction of viable T. cruzi parasites after leukoreduction and a complete reduction (100%) after the riboflavin and UV light treatment. Riboflavin and UV light treatment and leukoreduction used in conjunction appears to eliminate significant amounts of viable T. cruzi in whole blood. Both strategies could complement other blood bank measures already implemented to prevent the transmission of T. cruzi via blood transfusion. © 2017 AABB.

Constructing a model of effective information dissemination in a crisis. Information dissemination, Crisis, Crises, Tuberculosis, Dissemination of information, Meta-ethnographic analysis, Social marketing

OpenAIRE

Fiona Duggan; Linda Banwell

2004-01-01

A model of effective information dissemination in a crisis was developed from a Ph.D. study of information dissemination during a suspected TB outbreak. The research aimed to characterise and evaluate the dissemination of information to the community during the incident. A qualitative systematic review of the research literature identified twenty relevant studies. Meta-ethnographic analysis of these studies highlighted the key factors in effective dissemination. Consideration of these factors...

A preface on advances in diagnostics for infectious and parasitic diseases: detecting parasites of medical and veterinary importance.

Science.gov (United States)

Stothard, J Russell; Adams, Emily

2014-12-01

There are many reasons why detection of parasites of medical and veterinary importance is vital and where novel diagnostic and surveillance tools are required. From a medical perspective alone, these originate from a desire for better clinical management and rational use of medications. Diagnosis can be at the individual-level, at close to patient settings in testing a clinical suspicion or at the community-level, perhaps in front of a computer screen, in classification of endemic areas and devising appropriate control interventions. Thus diagnostics for parasitic diseases has a broad remit as parasites are not only tied with their definitive hosts but also in some cases with their vectors/intermediate hosts. Application of current diagnostic tools and decision algorithms in sustaining control programmes, or in elimination settings, can be problematic and even ill-fitting. For example in resource-limited settings, are current diagnostic tools sufficiently robust for operational use at scale or are they confounded by on-the-ground realities; are the diagnostic algorithms underlying public health interventions always understood and well-received within communities which are targeted for control? Within this Special Issue (SI) covering a variety of diseases and diagnostic settings some answers are forthcoming. An important theme, however, throughout the SI is to acknowledge that cross-talk and continuous feedback between development and application of diagnostic tests is crucial if they are to be used effectively and appropriately.

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

Science.gov (United States)

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

Development and Validation of a Biodynamic Model for Mechanistically Predicting Metal Accumulation in Fish-Parasite Systems.

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T T Yen Le

Full Text Available Because of different reported effects of parasitism on the accumulation of metals in fish, it is important to consider parasites while interpreting bioaccumulation data from biomonitoring programmes. Accordingly, the first step is to take parasitism into consideration when simulating metal bioaccumulation in the fish host under laboratory conditions. In the present study, the accumulation of metals in fish-parasite systems was simulated by a one-compartment toxicokinetic model and compared to uninfected conspecifics. As such, metal accumulation in fish was assumed to result from a balance of different uptake and loss processes depending on the infection status. The uptake by parasites was considered an efflux from the fish host, similar to elimination. Physiological rate constants for the uninfected fish were parameterised based on the covalent index and the species weight while the parameterisation for the infected fish was carried out based on the reported effects of parasites on the uptake kinetics of the fish host. The model was then validated for the system of the chub Squalius cephalus and the acanthocephalan Pomphorhynchus tereticollis following 36-day exposure to waterborne Pb. The dissolved concentration of Pb in the exposure tank water fluctuated during the exposure, ranging from 40 to 120 μg/L. Generally, the present study shows that the one-compartment model can be an effective method for simulating the accumulation of metals in fish, taking into account effects of parasitism. In particular, the predicted concentrations of Cu, Fe, Zn, and Pb in the uninfected chub as well as in the infected chub and the acanthocephalans were within one order of magnitude of the measurements. The variation in the absorption efficiency and the elimination rate constant of the uninfected chub resulted in variations of about one order of magnitude in the predicted concentrations of Pb. Inclusion of further assumptions for simulating metal accumulation

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

Scale up of a Plasmodium falciparum elimination program and surveillance system in Kayin State, Myanmar [version 1; referees: 2 approved

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Daniel M. Parker

2017-10-01

Full Text Available Background: Myanmar has one of the largest malaria burdens in Southeast Asia. Along the border with Thailand, Plasmodium falciparum parasites are increasingly showing reduced sensitivity to artemisinin combination therapies. Given that there are no current alternative treatment therapies, one proposed solution to the threat of untreatable P. falciparum malaria is to eliminate the parasite from the region. Several small-scale elimination projects have been piloted along the Myanmar-Thailand border. Following their success, this operational research aimed to scale up the elimination to a broad area of Eastern Kayin State, Myanmar. Methods: The project relied on geographic reconnaissance and a geographic information system, community engagement, generalized access to community-based early diagnosis and treatment, near real-time epidemiological surveillance, cross sectional malaria prevalence surveys and targeted mass drug administration in villages with high prevalence of P. falciparum malaria. Molecular markers of drug resistance were also monitored in individuals with symptomatic and asymptomatic infections. Discussion: This project illustrates the establishment of an elimination project and operational research in a remote, rural area encompassing several armed groups, multiple political organizations and a near-absent health care infrastructure. The establishment of the project relied on a strong rapport with the target community, on-the-ground knowledge (through geographic surveys and community engagement, rapid decision making and an approach that was flexible enough to quickly adapt to a complex landscape. The elimination project is ongoing, now over three years in operation, and assessment of the impact of this operational research will follow. This project has relevance not only for other malaria elimination projects but also for operational research aimed at eliminating other diseases.

Genetics, chromatin diminution, and sex chromosome evolution in the parasitic nematode genus Strongyloides.

Science.gov (United States)

Nemetschke, Linda; Eberhardt, Alexander G; Hertzberg, Hubertus; Streit, Adrian

2010-10-12

When chromatin diminution occurs during a cell division a portion of the chromatin is eliminated, resulting in daughter cells with a smaller amount of genetic material. In the parasitic roundworms Ascaris and Parascaris, chromatin diminution creates a genetic difference between the soma and the germline. However, the function of chromatin diminution remains a mystery, because the vast majority of the eliminated DNA is noncoding. Within the parasitic roundworm genus Strongyloides, S. stercoralis (in man) and S. ratti (in rat) employ XX/XO sex determination, but the situation in S. papillosus (in sheep) is different but controversial. We demonstrate genetically that S. papillosus employs sex-specific chromatin diminution to eliminate an internal portion of one of the two homologs of one chromosome pair in males. Contrary to ascarids, the eliminated DNA in S. papillosus contains a large number of genes. We demonstrate that the region undergoing diminution is homologous to the X chromosome of the closely related S. ratti. The flanking regions, which are not diminished, are homologous to the S. ratti autosome number I. Furthermore, we found that the diminished chromosome is not incorporated into sperm, resulting in a male-specific transmission ratio distortion. Our data indicate that on the evolutionary path to S. papillosus, the X chromosome fused with an autosome. Chromatin diminution serves to functionally restore an XX/XO sex-determining system. A consequence of the fusion and the process that copes with it is a transmission ratio distortion in males for certain loci. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evidence-Based Psychosocial Treatments for Pediatric Elimination Disorders.

Science.gov (United States)

Shepard, Jaclyn A; Poler, Joseph E; Grabman, Jesse H

2017-01-01

Pediatric elimination disorders are common in childhood, yet psychosocial correlates are generally unclear. Given the physiological concomitants of both enuresis and encopresis, and the fact that many children with elimination disorders are initially brought to their primary care physician for treatment, medical evaluation and management are crucial and may serve as the first-line treatment approach. Scientific investigation on psychological and behavioral interventions has progressed over the past couple of decades, resulting in the identification of effective treatments for enuresis and encopresis. However, the body of literature has inherent challenges, particularly given the multicomponent nature of many of the treatment packages. This review identified 25 intervention studies-18 for nocturnal enuresis and 7 for encopresis-over the past 15 years and classified them according to the guidelines set forth by the Task Force on the Promotion and Dissemination of Psychological Procedures. For nocturnal enuresis, the urine alarm and dry-bed training were identified as well-established treatments, Full Spectrum Home Therapy was probably efficacious, lifting was possibly efficacious, and hypnotherapy and retention control training were classified as treatments of questionable efficacy. For encopresis, only two probably efficacious treatments were identified: biofeedback and enhanced toilet training (ETT). Best practice recommendations and suggestions for future research are provided to address existing limitations, including heterogeneity and the multicomponent nature of many of the interventions for pediatric elimination disorders.

Reactive Case Detection for Plasmodium vivax Malaria Elimination in Rural Amazonia.

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Pablo S Fontoura

2016-12-01

Full Text Available Malaria burden in Brazil has reached its lowest levels in 35 years and Plasmodium vivax now accounts for 84% of cases countrywide. Targeting residual malaria transmission entrenched in the Amazon is the next major challenge for ongoing elimination efforts. Better strategies are urgently needed to address the vast reservoir of asymptomatic P. vivax carriers in this and other areas approaching malaria elimination.We evaluated a reactive case detection (RCD strategy tailored for P. vivax transmission in farming settlements in the Amazon Basin of Brazil. Over six months, 41 cases detected by passive surveillance triggered four rounds of RCD (0, 30, 60, and 180 days after index case enrollment, using microscopy- and quantitative real-time polymerase chain reaction (qPCR-based diagnosis, comprising subjects sharing the household (HH with the index case (n = 163, those living in the 5 nearest HHs within 3 km (n = 878, and individuals from 5 randomly chosen control HHs located > 5 km away from index cases (n = 841. Correlates of infection were identified with mixed-effects logistic regression models. Molecular genotyping was used to infer local parasite transmission networks.Subjects in index and neighbor HHs were significantly more likely to be parasitemic than control HH members, after adjusting for potential confounders, and together harbored > 90% of the P. vivax biomass in study subjects. Clustering patterns were temporally stable. Four rounds of microscopy-based RCD would identify only 49.5% of the infections diagnosed by qPCR, but 76.8% of the total parasite biomass circulating in the proximity of index HHs. However, control HHs accounted for 27.6% of qPCR-positive samples, 92.6% of them from asymptomatic carriers beyond the reach of RCD. Molecular genotyping revealed high P. vivax diversity, consistent with complex transmission networks and multiple sources of infection within clusters, potentially complicating malaria elimination efforts.

Indonesia knowledge dissemination: a snapshot

Science.gov (United States)

Nasution, M. K. M.

2018-03-01

The educational progress of a country or educational institution is measured through the implementation of knowledge dissemination. Evidence of knowledge dissemination has carried out be in form of the type of published document, which is based on the databases of the index of scientific publications: Scopus. This paper expresses a simple form of knowledge dissemination based on document type. Although the growth of knowledge dissemination does not have the same pattern based on the appearance of document types, the general implementation is almost the same. However, maximum effort needs to be done by PTN-bh to support Indonesia knowledge dissemination.

Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria.

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Freya M Shearer

2016-08-01

Full Text Available Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated.A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines.We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified.

Cytoplasmic free Ca2+ is essential for multiple steps in malaria parasite egress from infected erythrocytes

Directory of Open Access Journals (Sweden)

Glushakova Svetlana

2013-01-01

Full Text Available Abstract Background Egress of Plasmodium falciparum, from erythrocytes at the end of its asexual cycle and subsequent parasite invasion into new host cells, is responsible for parasite dissemination in the human body. The egress pathway is emerging as a coordinated multistep programme that extends in time for tens of minutes, ending with rapid parasite extrusion from erythrocytes. While the Ca2+ regulation of the invasion of P. falciparum in erythrocytes is well established, the role of Ca2+ in parasite egress is poorly understood. This study analysed the involvement of cytoplasmic free Ca2+ in infected erythrocytes during the multistep egress programme of malaria parasites. Methods Live-cell fluorescence microscopy was used to image parasite egress from infected erythrocytes, assessing the effect of drugs modulating Ca2+ homeostasis on the egress programme. Results A steady increase in cytoplasmic free Ca2+ is found to precede parasite egress. This increase is independent of extracellular Ca2+ for at least the last two hours of the cycle, but is dependent upon Ca2+ release from internal stores. Intracellular BAPTA chelation of Ca2+ within the last 45 minutes of the cycle inhibits egress prior to parasitophorous vacuole swelling and erythrocyte membrane poration, two characteristic morphological transformations preceding parasite egress. Inhibitors of the parasite endoplasmic reticulum (ER Ca2+-ATPase accelerate parasite egress, indicating that Ca2+ stores within the ER are sufficient in supporting egress. Markedly accelerated egress of apparently viable parasites was achieved in mature schizonts using Ca2+ ionophore A23187. Ionophore treatment overcomes the BAPTA-induced block of parasite egress, confirming that free Ca2+ is essential in egress initiation. Ionophore treatment of immature schizonts had an adverse effect inducing parasitophorous vacuole swelling and killing the parasites within the host cell. Conclusions The parasite egress

Diagnostics of intestinal parasites in light microscopy among the population of children in eastern Afghanistan

Directory of Open Access Journals (Sweden)

Krzysztof Korzeniewski

2016-09-01

The variety of detected intestinal pathogens in examined children’s population has required the use of combination of multiple diagnostic methods in light microscopy, and finally improved the detection rates of intestinal parasites and helped eliminate infections with nematodes, cestodes, trematodes, and protozoa using appropriate treatment in the study population.

Follicular Helper T Cells are Essential for the Elimination of Plasmodium Infection

Directory of Open Access Journals (Sweden)

Damián Pérez-Mazliah

2017-10-01

Full Text Available CD4+ follicular helper T (Tfh cells have been shown to be critical for the activation of germinal center (GC B-cell responses. Similar to other infections, Plasmodium infection activates both GC as well as non-GC B cell responses. Here, we sought to explore whether Tfh cells and GC B cells are required to eliminate a Plasmodium infection. A CD4 T cell-targeted deletion of the gene that encodes Bcl6, the master transcription factor for the Tfh program, resulted in complete disruption of the Tfh response to Plasmodium chabaudi in C57BL/6 mice and consequent disruption of GC responses and IgG responses and the inability to eliminate the otherwise self-resolving chronic P. chabaudi infection. On the other hand, and contrary to previous observations in immunization and viral infection models, Signaling Lymphocyte Activation Molecule (SLAM-Associated Protein (SAP-deficient mice were able to activate Tfh cells, GC B cells, and IgG responses to the parasite. This study demonstrates the critical role for Tfh cells in controlling this systemic infection, and highlights differences in the signals required to activate GC B cell responses to this complex parasite compared with those of protein immunizations and viral infections. Therefore, these data are highly pertinent for designing malaria vaccines able to activate broadly protective B-cell responses.

Agricultural information dissemination using ICTs: A review and analysis of information dissemination models in China

Directory of Open Access Journals (Sweden)

Yun Zhang

2016-03-01

Full Text Available Over the last three decades, China’s agriculture sector has been transformed from the traditional to modern practice through the effective deployment of Information and Communication Technologies (ICTs. Information processing and dissemination have played a critical role in this transformation process. Many studies in relation to agriculture information services have been conducted in China, but few of them have attempted to provide a comprehensive review and analysis of different information dissemination models and their applications. This paper aims to review and identify the ICT based information dissemination models in China and to share the knowledge and experience in applying emerging ICTs in disseminating agriculture information to farmers and farm communities to improve productivity and economic, social and environmental sustainability. The paper reviews and analyzes the development stages of China’s agricultural information dissemination systems and different mechanisms for agricultural information service development and operations. Seven ICT-based information dissemination models are identified and discussed. Success cases are presented. The findings provide a useful direction for researchers and practitioners in developing future ICT based information dissemination systems. It is hoped that this paper will also help other developing countries to learn from China’s experience and best practice in their endeavor of applying emerging ICTs in agriculture information dissemination and knowledge transfer.

Method of Measuring the Mismatch of Parasitic Capacitance in MEMS Accelerometer Based on Regulating Electrostatic Stiffness

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Xianshan Dong

2018-03-01

Full Text Available For the MEMS capacitive accelerometer, parasitic capacitance is a serious problem. Its mismatch will deteriorate the performance of accelerometer. Obtaining the mismatch of the parasitic capacitance precisely is helpful for improving the performance of bias and scale. Currently, the method of measuring the mismatch is limited in the direct measuring using the instrument. This traditional method has low accuracy for it would lead in extra parasitic capacitive and have other problems. This paper presents a novel method based on the mechanism of a closed-loop accelerometer. The strongly linear relationship between the output of electric force and the square of pre-load voltage is obtained through theoretical derivation and validated by experiment. Based on this relationship, the mismatch of parasitic capacitance can be obtained precisely through regulating electrostatic stiffness without other equipment. The results can be applied in the design of decreasing the mismatch and electrical adjusting for eliminating the influence of the mismatch.

One world health: socioeconomic burden and parasitic disease control priorities.

Science.gov (United States)

Torgerson, Paul R

2013-08-01

Parasitic diseases present a considerable socio-economic impact to society. Zoonotic parasites can result in a considerable burden of disease in people and substantive economic losses to livestock populations. Ameliorating the effects of these diseases may consist of attempts at eradicating specific diseases at a global level, eliminating them at a national or local level or controlling them to minimise incidence. Alternatively with some parasitic zoonoses it may only be possible to treat human and animal cases as they arise. The choice of approach will be determined by the potential effectiveness of a disease control programme, its cost and the cost effectiveness or cost benefit of undertaking the intervention. Furthermore human disease burden is being increasingly measured by egalitarian non-financial measures which are difficult to apply to livestock. This adds additional challenges to the assessment of socio-economic burdens of zoonotic diseases. Using examples from the group of neglected zoonotic diseases, information regarding the socio-economic effects is reviewed together with how this information is used in decision making with regard to disease control and treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

Operational strategies of anti-malarial drug campaigns for malaria elimination in Zambia's southern province: a simulation study.

Science.gov (United States)

Stuckey, Erin M; Miller, John M; Littrell, Megan; Chitnis, Nakul; Steketee, Rick

2016-03-09

Malaria elimination requires reducing both the potential of mosquitoes to transmit parasites to humans and humans to transmit parasites to mosquitoes. To achieve this goal in Southern province, Zambia a mass test and treat (MTAT) campaign was conducted from 2011-2013 to complement high coverage of long-lasting insecticide-treated nets (LLIN). To identify factors likely to increase campaign effectiveness, a modelling approach was applied to investigate the simulated effect of alternative operational strategies for parasite clearance in southern province. OpenMalaria, a discrete-time, individual-based stochastic model of malaria, was parameterized for the study area to simulate anti-malarial drug administration for interruption of transmission. Simulations were run for scenarios with a range of artemisinin-combination therapies, proportion of the population reached by the campaign, targeted age groups, time between campaign rounds, Plasmodium falciparum test protocols, and the addition of drugs aimed at preventing onward transmission. A sensitivity analysis was conducted to assess uncertainty of simulation results. Scenarios were evaluated based on the reduction in all-age parasite prevalence during the peak transmission month one year following the campaign, compared to the currently-implemented strategy of MTAT 19 % population coverage at pilot and 40 % coverage during the first year of implementation in the presence of 56 % LLIN use and 18 % indoor residual spray coverage. Simulation results suggest the most important determinant of success in reducing prevalence is the population coverage achieved in the campaign, which would require more than 1 year of campaign implementation for elimination. The inclusion of single low-dose primaquine, which acts as a gametocytocide, or ivermectin, which acts as an endectocide, to the drug regimen did not further reduce parasite prevalence one year following the campaign compared to the currently-implemented strategy

Disseminated cysticercosis: clinical spectrum, Toll-like receptor-4 gene polymorphisms and role of albendazole

Science.gov (United States)

Qavi, Abdul; Garg, Ravindra Kumar; Malhotra, Hardeep Singh; Jain, Amita; Kumar, Neeraj; Malhotra, Kiran Preet; Srivastava, Pradeep Kumar; Verma, Rajesh; Sharma, Praveen Kumar

2016-01-01

27 patients. Of the 4 deaths recorded, 3 had a heavy parasitic load and died after praziquantel therapy. Toll-like receptor-4 gene polymorphisms are associated with an increased susceptibility to disseminated cysticercosis, in the Indian population. Albendazole treatment seems to reduce the lesion load and improve symptoms. PMID:27684822

Costs of eliminating malaria and the impact of the global fund in 34 countries.

Directory of Open Access Journals (Sweden)

Brittany Zelman

Full Text Available International financing for malaria increased more than 18-fold between 2000 and 2011; the largest source came from The Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund. Countries have made substantial progress, but achieving elimination requires sustained finances to interrupt transmission and prevent reintroduction. Since 2011, global financing for malaria has declined, fueling concerns that further progress will be impeded, especially for current malaria-eliminating countries that may face resurgent malaria if programs are disrupted.This study aims to 1 assess past total and Global Fund funding to the 34 current malaria-eliminating countries, and 2 estimate their future funding needs to achieve malaria elimination and prevent reintroduction through 2030.Historical funding is assessed against trends in country-level malaria annual parasite incidences (APIs and income per capita. Following Kizewski et al. (2007, program costs to eliminate malaria and prevent reintroduction through 2030 are estimated using a deterministic model. The cost parameters are tailored to a package of interventions aimed at malaria elimination and prevention of reintroduction.The majority of Global Fund-supported countries experiencing increases in total funding from 2005 to 2010 coincided with reductions in malaria APIs and also overall GNI per capita average annual growth. The total amount of projected funding needed for the current malaria-eliminating countries to achieve elimination and prevent reintroduction through 2030 is approximately US$8.5 billion, or about $1.84 per person at risk per year (PPY (ranging from $2.51 PPY in 2014 to $1.43 PPY in 2030.Although external donor funding, particularly from the Global Fund, has been key for many malaria-eliminating countries, sustained and sufficient financing is critical for furthering global malaria elimination. Projected cost estimates for elimination provide policymakers with an indication of the

Dissemination and Exploitation Strategy

DEFF Research Database (Denmark)

Badger, Merete; Monaco, Lucio; Fransson, Torsten

of Technology in Sweden, Politecnico di Torino in Italy, and Eindhoven University of Technology in the Netherlands. The project is partially funded by the European Commission under the 7th Framework Programme (project no. RI-283746). This report describes the final dissemination and exploitation strategy...... for project Virtual Campus Hub. A preliminary dissemination and exploitation plan was setup early in the project as described in the deliverable D6.1 Dissemination strategy paper - preliminary version. The plan has been revised on a monthly basis during the project’s lifecycle in connection with the virtual...

Parasites of freshwater fishes in North America: why so neglected?

Science.gov (United States)

Scholz, Tomáš; Choudhury, Anindo

2014-02-01

Fish parasitology has a long tradition in North America and numerous parasitologists have contributed considerably to the current knowledge of the diversity and biology of protistan and metazoan parasites of freshwater fishes. The Journal of Parasitology has been essential in disseminating this knowledge and remains a significant contributor to our understanding of fish parasites in North America as well as more broadly at the international level. However, with a few exceptions, the importance of fish parasites has decreased during the last decades, which is reflected in the considerable decline of funding and corresponding decrease of attention paid to these parasites in Canada and the United States of America. After the 'golden age' in the second half of the 20th Century, fish parasitology in Canada and the United States went in a new direction, driven by technology and a shift in priorities. In contrast, fish parasitology in Mexico has undergone rapid development since the early 1990s, partly due to extensive international collaboration and governmental funding. A critical review of the current data on the parasites of freshwater fishes in North America has revealed considerable gaps in the knowledge of their species composition, host specificity, life cycles, evolution, phylogeography, and relationships with their fish hosts. As to the key question, "Why so neglected?" this is probably because: (1) fish parasites are not in the forefront due to their lesser economic importance; (2) there is little funding for this kind of research, especially if a practical application is not immediately apparent; and (3) of shifting interests and a shortage of key personalities to train a new generation (they switched to marine habitats or other fields). Some of the opportunities for future research are outlined, such as climate change and cryptic species diversity. A significant problem challenging future research seems to be the loss of trained and experienced fish

Impact of parasitic thermal effects on thermoelectric property measurements by Harman method

International Nuclear Information System (INIS)

Kwon, Beomjin; Baek, Seung-Hyub; Keun Kim, Seong; Kim, Jin-Sang

2014-01-01

Harman method is a rapid and simple technique to measure thermoelectric properties. However, its validity has been often questioned due to the over-simplified assumptions that this method relies on. Here, we quantitatively investigate the influence of the previously ignored parasitic thermal effects on the Harman method and develop a method to determine an intrinsic ZT. We expand the original Harman relation with three extra terms: heat losses via both the lead wires and radiation, and Joule heating within the sample. Based on the expanded Harman relation, we use differential measurement of the sample geometry to measure the intrinsic ZT. To separately evaluate the parasitic terms, the measured ZTs with systematically varied sample geometries and the lead wire types are fitted to the expanded relation. A huge discrepancy (∼28%) of the measured ZTs depending on the measurement configuration is observed. We are able to separately evaluate those parasitic terms. This work will help to evaluate the intrinsic thermoelectric property with Harman method by eliminating ambiguities coming from extrinsic effects

Progress toward elimination of onchocerciasis in the Americas - 1993-2012.

Science.gov (United States)

2013-05-24

Onchocerciasis (river blindness) is caused by the parasitic worm Onchocerca volvulus, transmitted to humans by the bite of infected black flies of the genus Simulium, and is characterized by chronic skin disease, severe itching, and eye lesions that can progress to complete blindness. Currently, among approximately 123 million persons at risk for infection in 38 endemic countries, at least 25.7 million are infected, and 1 million are blinded or have severe visual impairment. Periodic, communitywide mass drug administration (MDA) with ivermectin (Mectizan, Merck) prevents eye and skin disease and might interrupt transmission of the infection, depending on the coverage, duration, and frequency of MDA. The Onchocerciasis Elimination Program for the Americas (OEPA) was launched in response to a 1991 resolution of the Pan American Health Organization (PAHO) calling for the elimination of onchocerciasis from the Americas. By the end of 2012, transmission of the infection, judged by surveys following World Health Organization (WHO) guidelines, had been interrupted or eliminated in four of the six endemic countries in the WHO Americas Region. Thus, in 2013, only 4% (23,378) of the 560,911 persons originally at risk in the Americas will be under ivermectin MDA. Active transmission currently is limited to two foci among Yanomami indigenes in adjacent border areas of Venezuela and Brazil.

Effectiveness of Gamma Irradiation for Decontamination of Microbes on Tea Parasite Herb Scurrula atropurpurea (Bl.) Dans

International Nuclear Information System (INIS)

Katrin, E.; Winarno, H.; Yulianti, M.

2011-01-01

The purpose of this study was to find the minimum and maximum dose of gamma irradiation on dried tea parasite herb that can reduce the number of microbes without reducing the inhibitory activity against leukemia L1210 cells. Samples of tea parasite herbs were irradiated by gamma rays with doses of 0, 5, 7.5, 10, 15 and 20 kGy. The microbial contamination, cytotoxic activities and the chromatogram profiles of irradiated and unirradiated samples were observed. The results revealed that the bacteria contaminants of 7.57 x 10 9 cfu/g were eliminated after irradiation of the samples with dose of ≥ 7.5 kGy, meanwhile the mold-yeast contaminants of 5.68 x 10 8 cfu/g were eliminated after irradiation of the samples with dose of ≥ 5 kGy. Ethyl acetate extracts of irradiated samples until the dose of 10 kGy were still able to maintain its cytotoxic activity against L1210 leukemia cells proliferation with IC 50 values of 9 cfu/g and 5.68 x 10 8 cfu/g respectively. At this condition, the bacteria and mold/yeast have been killed, whereas the cytotoxic activities of active components (ethyl acetate extract and fraction 2) in tea parasite herbs decreased, but the decrease was not significant and did not remove these cytotoxic activities. (author)

Human movement data for malaria control and elimination strategic planning.

Science.gov (United States)

Pindolia, Deepa K; Garcia, Andres J; Wesolowski, Amy; Smith, David L; Buckee, Caroline O; Noor, Abdisalan M; Snow, Robert W; Tatem, Andrew J

2012-06-18

Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM) in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i) discuss relevant types of HPM across spatial and temporal scales, (ii) document where datasets exist to quantify HPM, (iii) highlight where data gaps remain and (iv) briefly put forward methods for integrating these datasets in a Geographic Information System (GIS) framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

Bibliometric analysis of scientific literature on intestinal parasites in Argentina during the period 1985-2014.

Science.gov (United States)

Basualdo, Juan A; Grenóvero, María S; Bertucci, Evangelina; Molina, Nora B

2016-01-01

The study of scientific production is a good indicator of the progress in research and knowledge generation. Bibliometrics is a scientific discipline that uses a set of indicators to quantitatively express the bibliographic characteristics of scientific publications. The scientific literature on the epidemiology of intestinal parasites in Argentina is scattered in numerous sources, hindering access and visibility to the scientific community. Our purpose was to perform a quantitative, bibliometric study of the scientific literature on intestinal parasites in humans in Argentina published in the period 1985-2014. This bibliometric analysis showed an increase in the number of articles on intestinal parasites in humans in Argentina published over the past 30 years. Those articles showed a collaboration index similar to that of the literature, with a high index of institutionality for national institutions and a very low one for international collaboration. The original articles were published in scientific journals in the American Continent, Europe and Asia. The use of bibliometric indicators can provide a solid tool for the diagnosis and survey of the research on epidemiology of intestinal parasites and contributes to the dissemination and visibility of information on the scientific production developed in Argentina. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Competitive release and facilitation of drug-resistant parasites after therapeutic chemotherapy in a rodent malaria model

Science.gov (United States)

Wargo, A.R.; Huijben, S.; De Roode, J. C.; Shepherd, J.; Read, A.F.

2007-01-01

Malaria infections frequently consist of mixtures of drug-resistant and drug-sensitive parasites. If crowding occurs, where clonal population densities are suppressed by the presence of coinfecting clones, removal of susceptible clones by drug treatment could allow resistant clones to expand into the newly vacated niche space within a host. Theoretical models show that, if such competitive release occurs, it can be a potent contributor to the strength of selection, greatly accelerating the rate at which resistance spreads in a population. A variety of correlational field data suggest that competitive release could occur in human malaria populations, but direct evidence cannot be ethically obtained from human infections. Here we show competitive release after pyrimethamine curative chemotherapy of acute infections of the rodent malaria Plasmodium chabaudi in laboratory mice. The expansion of resistant parasite numbers after treatment resulted in enhanced transmission-stage densities. After the elimination or near-elimination of sensitive parasites, the number of resistant parasites increased beyond that achieved when a competitor had never been present. Thus, a substantial competitive release occurred, markedly elevating the fitness advantages of drug resistance above those arising from survival alone. This finding may explain the rapid spread of drug resistance and the subsequently brief useful lifespans of some antimalarial drugs. In a second experiment, where subcurative chemotherapy was administered, the resistant clone was only partly released from competitive suppression and experienced a restriction in the size of its expansion after treatment. This finding raises the prospect of harnessing in-host ecology to slow the spread of drug resistance. ?? 2007 by The National Academy of Sciences of the USA.

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.

Continental-scale, data-driven predictive assessment of eliminating the vector-borne disease, lymphatic filariasis, in sub-Saharan Africa by 2020.

Science.gov (United States)

Michael, Edwin; Singh, Brajendra K; Mayala, Benjamin K; Smith, Morgan E; Hampton, Scott; Nabrzyski, Jaroslaw

2017-09-27

There are growing demands for predicting the prospects of achieving the global elimination of neglected tropical diseases as a result of the institution of large-scale nation-wide intervention programs by the WHO-set target year of 2020. Such predictions will be uncertain due to the impacts that spatial heterogeneity and scaling effects will have on parasite transmission processes, which will introduce significant aggregation errors into any attempt aiming to predict the outcomes of interventions at the broader spatial levels relevant to policy making. We describe a modeling platform that addresses this problem of upscaling from local settings to facilitate predictions at regional levels by the discovery and use of locality-specific transmission models, and we illustrate the utility of using this approach to evaluate the prospects for eliminating the vector-borne disease, lymphatic filariasis (LF), in sub-Saharan Africa by the WHO target year of 2020 using currently applied or newly proposed intervention strategies. METHODS AND RESULTS: We show how a computational platform that couples site-specific data discovery with model fitting and calibration can allow both learning of local LF transmission models and simulations of the impact of interventions that take a fuller account of the fine-scale heterogeneous transmission of this parasitic disease within endemic countries. We highlight how such a spatially hierarchical modeling tool that incorporates actual data regarding the roll-out of national drug treatment programs and spatial variability in infection patterns into the modeling process can produce more realistic predictions of timelines to LF elimination at coarse spatial scales, ranging from district to country to continental levels. Our results show that when locally applicable extinction thresholds are used, only three countries are likely to meet the goal of LF elimination by 2020 using currently applied mass drug treatments, and that switching to more

Elimination of Onchocerciasis from Mexico.

Directory of Open Access Journals (Sweden)

Mario A Rodríguez-Pérez

Full Text Available Mexico is one of the six countries formerly endemic for onchocerciasis in Latin America. Transmission has been interrupted in the three endemic foci of that country and mass drug distribution has ceased. Three years after mass drug distribution ended, post-treatment surveillance (PTS surveys were undertaken which employed entomological indicators to check for transmission recrudescence.In-depth entomologic assessments were performed in 18 communities in the three endemic foci of Mexico. None of the 108,212 Simulium ochraceum s.l. collected from the three foci were found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA, resulting in a maximum upper bound of the 95% confidence interval (95%-ULCI of the infective rate in the vectors of 0.035/2,000 flies examined. This is an order of magnitude below the threshold of a 95%-ULCI of less than one infective fly per 2,000 flies tested, the current entomological criterion for interruption of transmission developed by the international community. The point estimate of seasonal transmission potential (STP was zero, and the upper bound of the 95% confidence interval for the STP ranged from 1.2 to 1.7 L3/person/season in the different foci. This value is below all previous estimates for the minimum transmission potential required to maintain the parasite population.The results from the in-depth entomological post treatment surveillance surveys strongly suggest that transmission has not resumed in the three foci of Mexico during the three years since the last distribution of ivermectin occurred; it was concluded that transmission remains undetectable without intervention, and Onchocerca volvulus has been eliminated from Mexico.

Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce.

Science.gov (United States)

DiCaprio, Erin; Purgianto, Anastasia; Li, Jianrong

2015-07-01

Human norovirus (NoV) is the major causative agent of fresh-produce-related outbreaks of gastroenteritis; however, the ecology and persistence of human NoV in produce systems are poorly understood. In this study, the effects of abiotic and biotic stresses on the internalization and dissemination of two human NoV surrogates (murine norovirus 1 [MNV-1] and Tulane virus [TV]) in romaine lettuce were determined. To induce abiotic stress, romaine lettuce was grown under drought and flood conditions that mimic extreme weather events, followed by inoculation of soil with MNV-1 or TV. Independently, lettuce plants were infected with lettuce mosaic virus (LMV) to induce biotic stress, followed by inoculation with TV. Plants were grown for 14 days, and viral titers in harvested tissues were determined by plaque assays. It was found that drought stress significantly decreased the rates of both MNV-1 and TV internalization and dissemination. In contrast, neither flood stress nor biotic stress significantly impacted viral internalization or dissemination. Additionally, the rates of TV internalization and dissemination in soil-grown lettuce were significantly higher than those for MNV-1. Collectively, these results demonstrated that (i) human NoV surrogates can be internalized via roots and disseminated to shoots and leaves of romaine lettuce grown in soil, (ii) abiotic stress (drought) but not biotic stress (LMV infection) affects the rates of viral internalization and dissemination, and (iii) the type of virus affects the efficiency of internalization and dissemination. This study also highlights the need to develop effective measures to eliminate internalized viruses in fresh produce. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

AIDS defining disease: Disseminated cryptococcosis

Directory of Open Access Journals (Sweden)

Roshan Anupama

2006-01-01

Full Text Available Disseminated cryptococcosis is one of the acquired immune deficiency syndrome defining criteria and the most common cause of life threatening meningitis. Disseminated lesions in the skin manifest as papules or nodules that mimic molluscum contagiosum (MC. We report here a human immunodeficiency virus positive patient who presented with MC like lesions. Disseminated cryptococcosis was confirmed by India ink preparation and histopathology. The condition of the patient improved with amphotercin B.

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.

Parasites reduce food web robustness because they are sensitive to secondary extinction as illustrated by an invasive estuarine snail

Science.gov (United States)

Lafferty, Kevin D.; Kuris, Armand M.

2009-01-01

A robust food web is one in which few secondary extinctions occur after removing species. We investigated how parasites affected the robustness of the Carpinteria Salt Marsh food web by conducting random species removals and a hypothetical, but plausible, species invasion. Parasites were much more likely than free-living species to suffer secondary extinctions following the removal of a free-living species from the food web. For this reason, the food web was less robust with the inclusion of parasites. Removal of the horn snail, Cerithidea californica, resulted in a disproportionate number of secondary parasite extinctions. The exotic Japanese mud snail, Batillaria attramentaria, is the ecological analogue of the native California horn snail and can completely replace it following invasion. Owing to the similarities between the two snail species, the invasion had no effect on predator–prey interactions. However, because the native snail is host for 17 host-specific parasites, and the invader is host to only one, comparison of a food web that includes parasites showed significant effects of invasion on the native community. The hypothetical invasion also significantly reduced the connectance of the web because the loss of 17 native trematode species eliminated many links.

Evasion and Immuno-Endocrine Regulation in Parasite Infection: Two Sides of the Same Coin in Chagas Disease?

Science.gov (United States)

Morrot, Alexandre; Villar, Silvina R; González, Florencia B; Pérez, Ana R

2016-01-01

Chagas disease is a serious illness caused by the protozoan parasite Trypanosoma cruzi. Nearly 30% of chronically infected people develop cardiac, digestive, or mixed alterations, suggesting a broad range of host-parasite interactions that finally impact upon chronic disease outcome. The ability of T. cruzi to persist and cause pathology seems to depend on diverse factors like T. cruzi strains, the infective load and the route of infection, presence of virulence factors, the parasite capacity to avoid protective immune response, the strength and type of host defense mechanisms and the genetic background of the host. The host-parasite interaction is subject to a constant neuro-endocrine regulation that is thought to influence the adaptive immune system, and as the infection proceeds it can lead to a broad range of outcomes, ranging from pathogen elimination to its continued persistence in the host. In this context, T. cruzi evasion strategies and host defense mechanisms can be envisioned as two sides of the same coin, influencing parasite persistence and different outcomes observed in Chagas disease. Understanding how T. cruzi evade host's innate and adaptive immune response will provide important clues to better dissect mechanisms underlying the pathophysiology of Chagas disease.

Smart-tag Based Data Dissemination

DEFF Research Database (Denmark)

Bonnet, Philippe; Beaufour, Allan; Leopold, Martin

2002-01-01

Monitoring wide, hostile areas requires disseminating data between fixed, disconnected clusters of sensor nodes. It is not always possible to install long-range radios in order to cover the whole area. We propose to leverage the movement of mobile individuals, equipped with smart-tags, to dissemi......-tag based data dissemination. We use simulation to study the characteristics of the model we propose. Finally, we present an implementation based on Bluetooth smart-tags.......Monitoring wide, hostile areas requires disseminating data between fixed, disconnected clusters of sensor nodes. It is not always possible to install long-range radios in order to cover the whole area. We propose to leverage the movement of mobile individuals, equipped with smart......-tags, to disseminate data across disconnected static nodes spread across a wide area. Static nodes and mobile smart-tags exchange data when they are in the vicinity of each other; smart-tags disseminate data as they move around. In this paper, we propose an algorithm for update propagation and a model for smart...

Disseminated sporotrichosis in an immunocompetent patient.

Science.gov (United States)

Hassan, Kareem; Turker, Tolga; Zangeneh, Tirdad

2016-01-01

Sporothrix schenckii, the causative agent of sporotrichosis, is a relatively rare infection. Local infection usually occurs through direct inoculation of the organism through the skin; disseminated disease is rarely seen. This article describes a case of disseminated sporotrichosis in a middle-aged man without the commonly seen risk factors for dissemination.

Human movement data for malaria control and elimination strategic planning

Directory of Open Access Journals (Sweden)

Pindolia Deepa K

2012-06-01

Full Text Available Abstract Recent increases in funding for malaria control have led to the reduction in transmission in many malaria endemic countries, prompting the national control programmes of 36 malaria endemic countries to set elimination targets. Accounting for human population movement (HPM in planning for control, elimination and post-elimination surveillance is important, as evidenced by previous elimination attempts that were undermined by the reintroduction of malaria through HPM. Strategic control and elimination planning, therefore, requires quantitative information on HPM patterns and the translation of these into parasite dispersion. HPM patterns and the risk of malaria vary substantially across spatial and temporal scales, demographic and socioeconomic sub-groups, and motivation for travel, so multiple data sets are likely required for quantification of movement. While existing studies based on mobile phone call record data combined with malaria transmission maps have begun to address within-country HPM patterns, other aspects remain poorly quantified despite their importance in accurately gauging malaria movement patterns and building control and detection strategies, such as cross-border HPM, demographic and socioeconomic stratification of HPM patterns, forms of transport, personal malaria protection and other factors that modify malaria risk. A wealth of data exist to aid filling these gaps, which, when combined with spatial data on transport infrastructure, traffic and malaria transmission, can answer relevant questions to guide strategic planning. This review aims to (i discuss relevant types of HPM across spatial and temporal scales, (ii document where datasets exist to quantify HPM, (iii highlight where data gaps remain and (iv briefly put forward methods for integrating these datasets in a Geographic Information System (GIS framework for analysing and modelling human population and Plasmodium falciparum malaria infection movements.

No effect of a parasite on reproduction in stickleback males: a laboratory artefact?

OpenAIRE

Candolin, U.; Voigt, H.-R.

2001-01-01

Experiments are often carried out in the laboratory under arti®cial conditions. Although this can control for confounding factors, it may eliminate important factors that under natural conditions mediate the interaction under investigation. Here, we show that different results can be gained in the ®eld and in the laboratory regarding host±parasite interaction. In the ®eld, courting three-spined stickleback males, Gasterosteus aculeatus, were less often infected with plerocercoids of ...

Disseminated sporotrichosis in an immunocompetent patient

OpenAIRE

Hassan, Kareem; Turker, Tolga; Zangeneh, Tirdad

2016-01-01

Abstract Sporothrix schenckii, the causative agent of sporotrichosis, is a relatively rare infection. Local infection usually occurs through direct inoculation of the organism through the skin; disseminated disease is rarely seen. This article describes a case of disseminated sporotrichosis in a middle-aged man without the commonly seen risk factors for dissemination.

B-cell infiltration and frequency of cytokine producing cells differ between localized and disseminated human cutaneous leishmaniases

Directory of Open Access Journals (Sweden)

MGS Vieira

2002-10-01

Full Text Available Biopsies from human localized cutaneous lesions (LCL n = 7 or disseminated lesions (DL n = 8 cases were characterized according to cellular infiltration,frequency of cytokine (IFN-g, TNF-alpha or iNOS enzyme producing cells. LCL, the most usual form of the disease with usually one or two lesions, exhibits extensive tissue damage. DL is a rare form with widespread lesions throughout the body; exhibiting poor parasite containment but less tissue damage. We demonstrated that LCL lesions exhibit higher frequency of B lymphocytes and a higher intensity of IFN-gamma expression. In both forms of the disease CD8+ were found in higher frequency than CD4+ T cells. Frequency of TNF-alpha and iNOS producing cells, as well as the frequency of CD68+ macrophages, did not differ between LCL and DL. Our findings reinforce the link between an efficient control of parasite and tissue damage, implicating higher frequency of IFN-gamma producing cells, as well as its possible counteraction by infiltrated B cells and hence possible humoral immune response in situ.

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.

Paradigms for parasite conservation.

Science.gov (United States)

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

A novel approach to eliminate Wolbachia infections in Nasonia vitripennis revealed different antibiotic resistance between two bacterial strains.

Science.gov (United States)

Liu, Hai-Yang; Wang, Yan-Kun; Zhi, Cong-Cong; Xiao, Jin-Hua; Huang, Da-Wei

2014-06-01

Wolbachia are widespread in insects and can manipulate host reproduction. Nasonia vitripennis is a widely studied organism with a very high prevalence of Wolbachia infection. To study the effect of Wolbachia infection in Nasonia spp., it is important to obtain noninfected individuals by artificial methods. Current methods that employ sugar water-containing antibiotics can successfully eliminate Wolbachia from the parasitic wasps; however, treatment of at least three generations is required. Here, we describe a novel, feasible, and effective approach to eliminate Wolbachia from N. vitripennis by feeding fly pupae continuously offering antibiotics to Nasonia populations, which shortened the time to eliminate the pathogens to two generations. Additionally, the Wolbachia Uni and CauB strains have obviously different rifampicin-resistance abilities, which is a previously unknown phenomenon. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

A research agenda for helminth diseases of humans: intervention for control and elimination.

Directory of Open Access Journals (Sweden)

Roger K Prichard

Full Text Available Recognising the burden helminth infections impose on human populations, and particularly the poor, major intervention programmes have been launched to control onchocerciasis, lymphatic filariasis, soil-transmitted helminthiases, schistosomiasis, and cysticercosis. The Disease Reference Group on Helminth Infections (DRG4, established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR, was given the mandate to review helminthiases research and identify research priorities and gaps. A summary of current helminth control initiatives is presented and available tools are described. Most of these programmes are highly dependent on mass drug administration (MDA of anthelmintic drugs (donated or available at low cost and require annual or biannual treatment of large numbers of at-risk populations, over prolonged periods of time. The continuation of prolonged MDA with a limited number of anthelmintics greatly increases the probability that drug resistance will develop, which would raise serious problems for continuation of control and the achievement of elimination. Most initiatives have focussed on a single type of helminth infection, but recognition of co-endemicity and polyparasitism is leading to more integration of control. An understanding of the implications of control integration for implementation, treatment coverage, combination of pharmaceuticals, and monitoring is needed. To achieve the goals of morbidity reduction or elimination of infection, novel tools need to be developed, including more efficacious drugs, vaccines, and/or antivectorial agents, new diagnostics for infection and assessment of drug efficacy, and markers for possible anthelmintic resistance. In addition, there is a need for the development of new formulations of some existing anthelmintics (e.g., paediatric formulations. To achieve ultimate elimination of helminth parasites, treatments for the above mentioned helminthiases, and for taeniasis

Disseminated cutaneous sporotrichosis.

Science.gov (United States)

Chang, Shurong; Hersh, Andrew M; Naughton, Greg; Mullins, Kevin; Fung, Maxwell A; Sharon, Victoria R

2013-11-15

The dimorphic fungus Sporothrix schenckii commonly causes localized cutaneous disease with lymphocutaneous distribution. However, disseminated sporotrichosis occurs predominantly in immunocompromised patients. We report a case of disseminated cutaneous sporotrichosis in a patient with newly diagnosed HIV with a CD4 count of 208. The patient presented with multiple cutaneous and subcutaneous nodules as well as fever and malaise. Tissue culture and skin biopsy confirmed the diagnosis of sporotrichosis. He was started on itraconazole 200mg twice a day with rapid resolution of fever along with cessation of the development of new lesions.

Transgenic Expression of the Anti-parasitic Factor TEP1 in the Malaria Mosquito Anopheles gambiae.

Directory of Open Access Journals (Sweden)

Gloria Volohonsky

2017-01-01

Full Text Available Mosquitoes genetically engineered to be resistant to Plasmodium parasites represent a promising novel approach in the fight against malaria. The insect immune system itself is a source of anti-parasitic genes potentially exploitable for transgenic designs. The Anopheles gambiae thioester containing protein 1 (TEP1 is a potent anti-parasitic protein. TEP1 is secreted and circulates in the mosquito hemolymph, where its activated cleaved form binds and eliminates malaria parasites. Here we investigated whether TEP1 can be used to create malaria resistant mosquitoes. Using a GFP reporter transgene, we determined that the fat body is the main site of TEP1 expression. We generated transgenic mosquitoes that express TEP1r, a potent refractory allele of TEP1, in the fat body and examined the activity of the transgenic protein in wild-type or TEP1 mutant genetic backgrounds. Transgenic TEP1r rescued loss-of-function mutations, but did not increase parasite resistance in the presence of a wild-type susceptible allele. Consistent with previous reports, TEP1 protein expressed from the transgene in the fat body was taken up by hemocytes upon a challenge with injected bacteria. Furthermore, although maturation of transgenic TEP1 into the cleaved form was impaired in one of the TEP1 mutant lines, it was still sufficient to reduce parasite numbers and induce parasite melanization. We also report here the first use of Transcription Activator Like Effectors (TALEs in Anopheles gambiae to stimulate expression of endogenous TEP1. We found that artificial elevation of TEP1 expression remains moderate in vivo and that enhancement of endogenous TEP1 expression did not result in increased resistance to Plasmodium. Taken together, our results reveal the difficulty of artificially influencing TEP1-mediated Plasmodium resistance, and contribute to further our understanding of the molecular mechanisms underlying mosquito resistance to Plasmodium parasites.

Effect of feeding Mucuna pruriens on helminth parasite infestation in lambs.

Science.gov (United States)

Huisden, C M; Adesogan, A T; Gaskin, J M; Courtney, C H; Raji, A M; Kang, T

2010-02-17

Mucuna pruriens is a tropical legume anecdotally reputed to have anthelmintic properties. This study was conducted to examine the validity of such claims. The aim of this study was to determine if ingestion of Mucuna seeds reduces helminth parasite infestation in lambs. Thirty-six Dorper x Katahdin ram lambs were assigned to three treatments, a cottonseed meal based control diet, a diet in which Mucuna replaced cottonseed meal and the control diet with levamisole (7.5mg/kg body weight) administration. All diets were isonitrogenous and isocaloric. The 12 lambs in each treatment were assigned randomly to 4 pens, each containing 3 lambs. Lambs were trickle infected three times per week by gavage with infectious Haemonchus contortus larvae (2000 larvae/lamb) for 3 weeks. Levamisole treatment decreased fecal egg counts by 87% and abomasal worm counts by 83%. Mucuna intake did not statistically affect fecal egg counts or abomasal worm counts, though numerical (P>0.10) reductions of 7.4% and 18.1%, respectively were evident. Anemia indicators, feed intake, and lamb growth were unaffected by treatment. Levamisole reduced the Haemonchus parasite burden in lambs significantly but feeding Mucuna reduced the burden by levels unlikely to eliminate the clinical effects of parasitism. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Elimination of Onchocerciasis from Mexico

Science.gov (United States)

Rodríguez-Pérez, Mario A.; Fernández-Santos, Nadia A.; Orozco-Algarra, María E.; Rodríguez-Atanacio, José A.; Domínguez-Vázquez, Alfredo; Rodríguez-Morales, Kristel B.; Real-Najarro, Olga; Prado-Velasco, Francisco G.; Cupp, Eddie W.; Richards, Frank O.; Hassan, Hassan K.; González-Roldán, Jesús F.; Kuri-Morales, Pablo A.; Unnasch, Thomas R.

2015-01-01

Background Mexico is one of the six countries formerly endemic for onchocerciasis in Latin America. Transmission has been interrupted in the three endemic foci of that country and mass drug distribution has ceased. Three years after mass drug distribution ended, post-treatment surveillance (PTS) surveys were undertaken which employed entomological indicators to check for transmission recrudescence. Methodology/Principal findings In-depth entomologic assessments were performed in 18 communities in the three endemic foci of Mexico. None of the 108,212 Simulium ochraceum s.l. collected from the three foci were found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in a maximum upper bound of the 95% confidence interval (95%-ULCI) of the infective rate in the vectors of 0.035/2,000 flies examined. This is an order of magnitude below the threshold of a 95%-ULCI of less than one infective fly per 2,000 flies tested, the current entomological criterion for interruption of transmission developed by the international community. The point estimate of seasonal transmission potential (STP) was zero, and the upper bound of the 95% confidence interval for the STP ranged from 1.2 to 1.7 L3/person/season in the different foci. This value is below all previous estimates for the minimum transmission potential required to maintain the parasite population. Conclusions/Significance The results from the in-depth entomological post treatment surveillance surveys strongly suggest that transmission has not resumed in the three foci of Mexico during the three years since the last distribution of ivermectin occurred; it was concluded that transmission remains undetectable without intervention, and Onchocerca volvulus has been eliminated from Mexico. PMID:26161558

Battlefield Awareness and Data Dissemination Intelligent Information Dissemination Server

National Research Council Canada - National Science Library

Schlossberg, Jon

1999-01-01

This report describe the research performed to design and develop software tools to facilitate the dissemination of battlefield data based on the Warfighter's needs and the ever changing world environment...

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

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 ...

The Plasmodium falciparum pseudoprotease SERA5 regulates the kinetics and efficiency of malaria parasite egress from host erythrocytes.

Directory of Open Access Journals (Sweden)

Christine R Collins

2017-07-01

Full Text Available Egress of the malaria parasite Plasmodium falciparum from its host red blood cell is a rapid, highly regulated event that is essential for maintenance and completion of the parasite life cycle. Egress is protease-dependent and is temporally associated with extensive proteolytic modification of parasite proteins, including a family of papain-like proteins called SERA that are expressed in the parasite parasitophorous vacuole. Previous work has shown that the most abundant SERA, SERA5, plays an important but non-enzymatic role in asexual blood stages. SERA5 is extensively proteolytically processed by a parasite serine protease called SUB1 as well as an unidentified cysteine protease just prior to egress. However, neither the function of SERA5 nor the role of its processing is known. Here we show that conditional disruption of the SERA5 gene, or of both the SERA5 and related SERA4 genes simultaneously, results in a dramatic egress and replication defect characterised by premature host cell rupture and the failure of daughter merozoites to efficiently disseminate, instead being transiently retained within residual bounding membranes. SERA5 is not required for poration (permeabilization or vesiculation of the host cell membrane at egress, but the premature rupture phenotype requires the activity of a parasite or host cell cysteine protease. Complementation of SERA5 null parasites by ectopic expression of wild-type SERA5 reversed the egress defect, whereas expression of a SERA5 mutant refractory to processing failed to rescue the phenotype. Our findings implicate SERA5 as an important regulator of the kinetics and efficiency of egress and suggest that proteolytic modification is required for SERA5 function. In addition, our study reveals that efficient egress requires tight control of the timing of membrane rupture.

Advanced gas-emission anode design for microfluidic fuel cell eliminating bubble accumulation

International Nuclear Information System (INIS)

Zhang, Hao; Xuan, Jin; Wang, Huizhi; Leung, Dennis Y C; Xu, Hong; Zhang, Li

2017-01-01

A microfluidic fuel cell is a low cost, easily fabricated energy device and is considered a promising energy supplier for portable electronics. However, the currently developed microfluidic fuel cells that are fed with hydrocarbon fuels are confronted with a bubble problem especially when operating at high current density conditions. In this work, a gas-emission anode is presented to eliminate the gas accumulation at the anode. This gas-emission anode is verified as a valid design for discharging gaseous products, which is especially beneficial for stable operation of microfluidic fuel cells. The electrochemical performance of a counter-flow microfluidic fuel cell equipped with a gas-emission anode was measured. The results indicate that the specific design of the gas-emission anode is essential for reducing the oxygen reduction reaction parasitic effect at the anode. Fuel utilization of 76.4% was achieved at a flow rate of 0.35 µ l min −1 . Current–voltage curves of single electrodes were measured and the parasitic effect at the anode was identified as the main performance limiting factor in the presented anode design. (paper)

45 CFR 1388.7 - Program criteria-dissemination.

Science.gov (United States)

2010-10-01

.... (a) Introduction to dissemination: The UAP disseminates information and research findings, including... Affiliated Programs, and State service systems to disseminate information to target audiences. (e) The...) The UAP must be a resource for information for individuals with developmental disabilities and their...

Specific methodology for capacitance imaging by atomic force microscopy: A breakthrough towards an elimination of parasitic effects

Energy Technology Data Exchange (ETDEWEB)

Estevez, Ivan [Laboratoire de Génie Électrique de Paris (LGEP), UMR 8507 CNRS-Supélec, Paris-Sud and UPMC Paris 06 Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex (France); Concept Scientific Instruments, ZA de Courtaboeuf, 2 rue de la Terre de Feu, 91940 Les Ulis (France); Chrétien, Pascal; Schneegans, Olivier; Houzé, Frédéric, E-mail: houze@lgep.supelec.fr [Laboratoire de Génie Électrique de Paris (LGEP), UMR 8507 CNRS-Supélec, Paris-Sud and UPMC Paris 06 Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex (France)

2014-02-24

On the basis of a home-made nanoscale impedance measurement device associated with a commercial atomic force microscope, a specific operating process is proposed in order to improve absolute (in sense of “nonrelative”) capacitance imaging by drastically reducing the parasitic effects due to stray capacitance, surface topography, and sample tilt. The method, combining a two-pass image acquisition with the exploitation of approach curves, has been validated on sets of calibration samples consisting in square parallel plate capacitors for which theoretical capacitance values were numerically calculated.

Parasites in marine food webs

Science.gov (United States)

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.

Factors influencing message dissemination through social media

Science.gov (United States)

Zheng, Zeyu; Yang, Huancheng; Fu, Yang; Fu, Dianzheng; Podobnik, Boris; Stanley, H. Eugene

2018-06-01

Online social networks strongly impact our daily lives. An internet user (a "Netizen") wants messages to be efficiently disseminated. The susceptible-infected-recovered (SIR) dissemination model is the traditional tool for exploring the spreading mechanism of information diffusion. We here test our SIR-based dissemination model on open and real-world data collected from Twitter. We locate and identify phase transitions in the message dissemination process. We find that message content is a stronger factor than the popularity of the sender. We also find that the probability that a message will be forwarded has a threshold that affects its ability to spread, and when the probability is above the threshold the message quickly achieves mass dissemination.

Antibiotic treatment leads to the elimination of Wolbachia endosymbionts and sterility in the diplodiploid collembolan Folsomia candida

Directory of Open Access Journals (Sweden)

Kingcombe Rachel

2009-08-01

Full Text Available Abstract Background Wolbachia is an extremely widespread bacterial endosymbiont of arthropods and nematodes that causes a variety of reproductive peculiarities. Parthenogenesis is one such peculiarity but it has been hypothesised that this phenomenon may be functionally restricted to organisms that employ haplodiploid sex determination. Using two antibiotics, tetracycline and rifampicin, we attempted to eliminate Wolbachia from the diplodiploid host Folsomia candida, a species of springtail which is a widely used study organism. Results Molecular assays confirmed that elimination of Wolbachia was successfully achieved through continuous exposure of populations (over two generations and several weeks to rifampicin administered as 2.7% dry weight of their yeast food source. The consequence of this elimination was total sterility of all individuals, despite the continuation of normal egg production. Conclusion Microbial endosymbionts play an obligatory role in the reproduction of their diplodiploid host, most likely one in which the parthenogenetic process is facilitated by Wolbachia. A hitherto unknown level of host-parasite interdependence is thus recorded.

REPAiR: REsource Management in Peri-urban AReas: Going Beyond Urban Metabolism : D 8.6 Detailed Dissemination Plan and Dissemination Kit

NARCIS (Netherlands)

Cerić, Dennis; Amenta, L.; Attademo, Anna

2017-01-01

The Detailed Dissemination Plan and Dissemination Kit is a strategic document for the beneficiaries helping them to establish the bases for their dissemination activities. It is a more detailed version of the Basic Dissemination Plan and Corporate Identity, deliverables of the REPAiR project D 8.3

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

D5.1 Dissemination Plan

DEFF Research Database (Denmark)

Buus, Lillian; Ryberg, Thomas; Eleftheriou, Paraskevi

2009-01-01

at defining the dissemination goals as well as the project’s target audience and channels through which the EATrain2 solution is going to be promoted. It also includes partners competences in the dissemination area and detailed schedule of events thematically related to the project’s scope. The deliverable...

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.

Identifying rapidly parasiticidal anti-malarial drugs using a simple and reliable in vitro parasite viability fast assay.

Science.gov (United States)

Linares, María; Viera, Sara; Crespo, Benigno; Franco, Virginia; Gómez-Lorenzo, María G; Jiménez-Díaz, María Belén; Angulo-Barturen, Íñigo; Sanz, Laura María; Gamo, Francisco-Javier

2015-11-05

The emergence of Plasmodium falciparum resistance to artemisinins threatens to undermine the effectiveness of artemisinin-based combination anti-malarial therapy. Developing suitable drugs to replace artemisinins requires the identification of new compounds that display rapid parasite killing kinetics. However, no current methods fully meet the requirements to screen large compound libraries for candidates with such properties. This study describes the development and validation of an in vitro parasite viability fast assay for identifying rapidly parasiticidal anti-malarial drugs. Parasite killing kinetics were determined by first culturing unlabelled erythrocytes with P. falciparum in the presence of anti-malarial drugs for 24 or 48 h. After removing the drug, samples were added to erythrocytes pre-labelled with intracellular dye to allow their subsequent identification. The ability of viable parasites to re-establish infection in labelled erythrocytes could then be detected by two-colour flow cytometry after tagging of parasite DNA. Thus, double-stained erythrocytes (with the pre-labelled intracellular dye and the parasite DNA dye) result only after establishment of new infections by surviving parasites. The capacity of the test anti-malarial drugs to eliminate viable parasites within 24 or 48 h could, therefore, be determined. The parasite viability fast assay could be completed within 48 h following drug treatment and distinguished between rapidly parasiticidal anti-malarial drugs versus those acting more slowly. The assay was validated against ten standard anti-malarial agents with known properties and results correlated well with established methods. An abbreviated assay, suitable for adaption to medium-high throughput screening, was validated and applied against a set of 20 compounds retrieved from the publically available Medicines for Malaria Venture 'Malaria Box'. The quantification of new infections to determine parasite viability offers important

10 CFR 470.20 - Dissemination of information.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Dissemination of information. 470.20 Section 470.20 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION APPROPRIATE TECHNOLOGY SMALL GRANTS PROGRAM § 470.20 Dissemination of information. DOE shall disseminate to the public, in an appropriate manner, information of the...

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

Science.gov (United States)

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.

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

Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas

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Marilaine Martins

2015-06-01

Full Text Available In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil were Medical Literature Analysis and Retrieval System Online (MEDLINE, Literatura Latino-Americana (LILACS and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

Progression of the load of waterborne and intestinal parasitic diseases in the State of Amazonas.

Science.gov (United States)

Martins, Marilaine; Lacerda, Marcus Vinícius Guimarães; Monteiro, Wuelton Marcelo; Moura, Marco Antonio Saboia; Santos, Eyde Cristianne Saraiva; Saraceni, Valéria; Saraiva, Maria Graças Gomes

2015-01-01

In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil) were Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana (LILACS) and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

Within- and among-family variation in parasite load and parasite-induced mortality in the land snail Arianta arbustorum, a host of parasitic mites.

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Schüpbach, Hans Ulrich; Baur, Bruno

2010-08-01

Variation in host susceptibility and parasite-induced mortality are preconditions for parasite-related selection on host populations. In terrestrial gastropods, variation in resistance against ectoparasite infection is poorly understood. We examined the within- and among-family variation in parasite load in full-siblings of the land snail Arianta arbustorum experimentally infected with Riccardoella limacum , a mite living in the mantle cavity of helicid land snails. We also quantified the influence of family origin and host size on parasite load and calculated its heritability (h(2)). Furthermore, we examined the influence of parasite load, snail size, and family origin on host winter mortality, an important life-history trait of A. arbustorum . Parasite load was heritable (h(2) = 0.63). In infected snails, parasite load was affected by family origin and increased with increasing shell size. Host mortality during hibernation increased with increasing parasite load and differed among families, but was not affected by snail size. Our results show high among-family variation both in resistance against ectoparasite infection and in host winter mortality. Furthermore, we show that parasite load is linked to snail size, which suggests that the proliferation of R. limacum is limited by resources provided by A. arbustorum .

Onchocerciasis in the Americas: from arrival to (near) elimination.

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Gustavsen, Ken; Hopkins, Adrian; Sauerbrey, Mauricio

2011-10-25

Onchocerciasis (river blindness) is a blinding parasitic disease that threatens the health of approximately 120 million people worldwide. While 99% of the population at-risk for infection from onchocerciasis live in Africa, some 500,000 people in the Americas are also threatened by infection. A relatively recent arrival to the western hemisphere, onchocerciasis was brought to the New World through the slave trade and spread through migration. The centuries since its arrival have seen advances in diagnosing, mapping and treating the disease. Once endemic to six countries in the Americas (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela), onchocerciasis is on track for interruption of transmission in the Americas by 2012, in line with Pan American Health Organization resolution CD48.R12. The success of this public health program is due to a robust public-private partnership involving national governments, local communities, donor organizations, intergovernmental bodies, academic institutions, non-profit organizations and the pharmaceutical industry. The lessons learned through the efforts in the Americas are in turn informing the program to control and eliminate onchocerciasis in Africa. However, continued support and investment are needed for program implementation and post-treatment surveillance to protect the gains to-date and ensure complete elimination is achieved and treatment can be safely stopped within all 13 regional foci.

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.

Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula.

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Patrícia de Brum Vieira

Full Text Available The infection caused by Trichomonas vaginalis is the most common but overlooked non-viral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5-nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII. In addition, the isolated saponin fraction improved the metronidazole effect against a metronidazole-resistant isolate and dramatically reduced the cytoadherence of T. vaginalis to human cells. Investigation of the mechanism of death showed that the saponin fraction induced the parasite death due to profound membrane damage, inducing a disturbance of intracellular content without nuclear damage. To the best of our knowledge, this is the first report of antitrichomonal activity in the bidesmosic saponins of Manilkara rufula.

Inevitability of Genetic Parasites

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Iranzo, Jaime; Puigbò, Pere; Lobkovsky, Alexander E.; Wolf, Yuri I.

2016-01-01

Abstract Almost all cellular life forms are hosts to diverse genetic parasites with various levels of autonomy including plasmids, transposons and viruses. Theoretical modeling of the evolution of primordial replicators indicates that parasites (cheaters) necessarily evolve in such systems and can be kept at bay primarily via compartmentalization. Given the (near) ubiquity, abundance and diversity of genetic parasites, the question becomes pertinent: are such parasites intrinsic to life? At least in prokaryotes, the persistence of parasites is linked to the rate of horizontal gene transfer (HGT). We mathematically derive the threshold value of the minimal transfer rate required for selfish element persistence, depending on the element duplication and loss rates as well as the cost to the host. Estimation of the characteristic gene duplication, loss and transfer rates for transposons, plasmids and virus-related elements in multiple groups of diverse bacteria and archaea indicates that most of these rates are compatible with the long term persistence of parasites. Notably, a small but non-zero rate of HGT is also required for the persistence of non-parasitic genes. We hypothesize that cells cannot tune their horizontal transfer rates to be below the threshold required for parasite persistence without experiencing highly detrimental side-effects. As a lower boundary to the minimum DNA transfer rate that a cell can withstand, we consider the process of genome degradation and mutational meltdown of populations through Muller’s ratchet. A numerical assessment of this hypothesis suggests that microbial populations cannot purge parasites while escaping Muller’s ratchet. Thus, genetic parasites appear to be virtually inevitable in cellular organisms. PMID:27503291

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

Parasitism and super parasitism of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) on Sitotroga cerealella (Oliver) (Lepidoptera: Gelechiidae) eggs

International Nuclear Information System (INIS)

Moreira, Marciene D.; Torres, Jorge B.

2009-01-01

The parasitoid Trichogramma has been used worldwide as biological control agent due to its wide geographic distribution, high specialization and efficacy against many lepidopteran pests. Biological and behavioral traits of Trichogramma pretiosum Riley parasitizing Sitotroga cerealella (Oliver) eggs were studied aiming to a better understanding of the Results from parasitism and super parasitism. The variables investigated were: host acceptance and contact time by T. pretiosum on parasitized host, percentage of parasitoid emergence, number of deformed individuals produced, egg-adult period, sex ratio, offspring female body size and longevity, and number of S. cerealella eggs parasitized/female. Parasitism rejection was observed on parasitized host eggs after 24, 72 and 120h of parasitism. The rejection was higher for eggs parasitized after 72h and 120h of parasitism as compared to the eggs after 24h of parasitism. T. pretiosum contact time on eggs after 24h of parasitism was greater than on 72 and 120h. The offspring produced from hosts from which a single parasitoid emerged were larger, exhibited no deformities and greater capacity of parasitism, different from those produced from eggs where two parasitoids emerged. Offspring longevity, however, was similar for females emerged from hosts from which one or two adults emerged. In Conclusion, T. pretiosum was able to recognize previously parasitized eggs and the super parasitism reduced the parasitoid.reproductive success. (author)

Dissemination strategy for Lean thinking in health care.

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Dannapfel, Petra; Poksinska, Bozena; Thomas, Kristin

2014-01-01

The purpose of this paper is to contribute to knowledge about dissemination strategies for Lean thinking throughout multiple healthcare organisations. The Ostergötland county council, Sweden (CCO) was chosen as a case study for an healthcare Lean-thinking dissemination strategies. Document analysis and interviews were used and results were compared with similar strategies employed by staff at the National Health Service Institute for Innovation (NHSI) and improvement in Great Britain and the Odense University Hospital in Denmark. The Lean improvement programme was introduced to tackle challenges such as an ageing society, rising care expectations and budgetary and economic constraints. It was designed as a long-term programme to create added value for patients and employee involvement. The dissemination strategy was: forming clear visions and objectives; piloting; training potential adopters; and formal dissemination. The CCO strategy was focused primarily on managers and was not meant to involve all staff until the implementation stage. Staff at the NHSI attempted to address nurses needs during dissemination, which questioned whether the CCO managers' dissemination strategy is sustainable. This paper inspires healthcare managers and decision makers who aim to disseminate Lean production in their organisations. There are many case studies describing Lean implementation in single healthcare organisations, but little is known about effective dissemination and implementation strategies in large healthcare systems. The authors, therefore, suggest activities for developing and implementing dissemination strategies in multiple healthcare organisations.

48 CFR 2905.101 - Methods of disseminating information.

Science.gov (United States)

2010-10-01

... information. 2905.101 Section 2905.101 Federal Acquisition Regulations System DEPARTMENT OF LABOR ACQUISITION PLANNING PUBLICIZING CONTRACT ACTIONS Dissemination of Information 2905.101 Methods of disseminating... dissemination of information concerning procurement actions. The Division of Acquisition Management Services...

Fish parasites

DEFF Research Database (Denmark)

This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

Malaria parasites: the great escape

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Laurent Rénia

2016-11-01

Full Text Available Parasites of the genus Plasmodium have a complex life cycle. They alternate between their final mosquito host and their intermediate hosts. The parasite can be either extra- or intracellular, depending on the stage of development. By modifying their shape, motility, and metabolic requirements, the parasite adapts to the different environments in their different hosts. The parasite has evolved to escape the multiple immune mechanisms in the host that try to block parasite development at the different stages of their development. In this article, we describe the mechanisms reported thus far that allow the Plasmodium parasite to evade innate and adaptive immune responses.

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.

Malaria medicines to address drug resistance and support malaria elimination efforts.

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Achan, Jane; Mwesigwa, Julia; Edwin, Chinagozi Precious; D'alessandro, Umberto

2018-01-01

Antimalarial drugs are essential weapons to fight malaria and have been used effectively since the 17 th century. However, P.falciparum resistance has been reported to almost all available antimalarial drugs, including artemisinin derivatives, raising concerns that this could jeopardize malaria elimination. Areas covered: In this article, we present a historical perspective of antimalarial drug resistance, review current evidence of resistance to available antimalarial drugs and discuss possible mitigating strategies to address this challenge. Expert commentary: The historical approach to drug resistance has been to change the national treatment policy to an alternative treatment. However, alternatives to artemisinin-based combination treatment are currently extremely limited. Innovative approaches utilizing available schizonticidal drugs such as triple combination therapies or multiple first line treatments could delay the emergence and spread of drug resistance. Transmission blocking drugs like primaquine may play a key role if given to a substantial proportion of malaria infected persons. Deploying antimalarial medicines in mass drug administration or mass screening and treatment campaigns could also contribute to containment efforts by eliminating resistant parasites in some settings. Ultimately, response to drug resistance should also include further investment in the development of new antimalarial drugs.

32 CFR 2400.28 - Dissemination of classified information.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Dissemination of classified information. 2400.28... SECURITY PROGRAM Safeguarding § 2400.28 Dissemination of classified information. Heads of OSTP offices... originating official may prescribe specific restrictions on dissemination of classified information when...

Protein moonlighting in parasitic protists.

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Ginger, Michael L

2014-12-01

Reductive evolution during the adaptation to obligate parasitism and expansions of gene families encoding virulence factors are characteristics evident to greater or lesser degrees in all parasitic protists studied to date. Large evolutionary distances separate many parasitic protists from the yeast and animal models upon which classic views of eukaryotic biochemistry are often based. Thus a combination of evolutionary divergence, niche adaptation and reductive evolution means the biochemistry of parasitic protists is often very different from their hosts and to other eukaryotes generally, making parasites intriguing subjects for those interested in the phenomenon of moonlighting proteins. In common with other organisms, the contribution of protein moonlighting to parasite biology is only just emerging, and it is not without controversy. Here, an overview of recently identified moonlighting proteins in parasitic protists is provided, together with discussion of some of the controversies.

Optimal control of epidemic information dissemination over networks.

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Chen, Pin-Yu; Cheng, Shin-Ming; Chen, Kwang-Cheng

2014-12-01

Information dissemination control is of crucial importance to facilitate reliable and efficient data delivery, especially in networks consisting of time-varying links or heterogeneous links. Since the abstraction of information dissemination much resembles the spread of epidemics, epidemic models are utilized to characterize the collective dynamics of information dissemination over networks. From a systematic point of view, we aim to explore the optimal control policy for information dissemination given that the control capability is a function of its distribution time, which is a more realistic model in many applications. The main contributions of this paper are to provide an analytically tractable model for information dissemination over networks, to solve the optimal control signal distribution time for minimizing the accumulated network cost via dynamic programming, and to establish a parametric plug-in model for information dissemination control. In particular, we evaluate its performance in mobile and generalized social networks as typical examples.

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.

Disseminating genetically modified (GM) maize technology to ...

African Journals Online (AJOL)

Disseminating genetically modified (GM) maize technology to smallholder farmers in the Eastern Cape province of South Africa: extension personnel's awareness of stewardship requirements and dissemination practices.

Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato

Science.gov (United States)

Tjiurutue, Muvari Connie; Palmer-Young, Evan C.; Adler, Lynn S.

2016-01-01

Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp.) preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum). In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua) and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics. PMID:27529694

Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato.

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Muvari Connie Tjiurutue

Full Text Available Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp. preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum. In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics.

A spread willingness computing-based information dissemination model.

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Huang, Haojing; Cui, Zhiming; Zhang, Shukui

2014-01-01

This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user's spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network.

Combining epidemiology with basic biology of sand flies, parasites, and hosts to inform leishmaniasis transmission dynamics and control.

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Courtenay, Orin; Peters, Nathan C; Rogers, Matthew E; Bern, Caryn

2017-10-01

Quantitation of the nonlinear heterogeneities in Leishmania parasites, sand fly vectors, and mammalian host relationships provides insights to better understand leishmanial transmission epidemiology towards improving its control. The parasite manipulates the sand fly via production of promastigote secretory gel (PSG), leading to the "blocked sand fly" phenotype, persistent feeding attempts, and feeding on multiple hosts. PSG is injected into the mammalian host with the parasite and promotes the establishment of infection. Animal models demonstrate that sand flies with the highest parasite loads and percent metacyclic promastigotes transmit more parasites with greater frequency, resulting in higher load infections that are more likely to be both symptomatic and efficient reservoirs. The existence of mammalian and sand fly "super-spreaders" provides a biological basis for the spatial and temporal clustering of clinical leishmanial disease. Sand fly blood-feeding behavior will determine the efficacies of indoor residual spraying, topical insecticides, and bed nets. Interventions need to have sufficient coverage to include transmission hot spots, especially in the absence of field tools to assess infectiousness. Interventions that reduce sand fly densities in the absence of elimination could have negative consequences, for example, by interfering with partial immunity conferred by exposure to sand fly saliva. A deeper understanding of both sand fly and host biology and behavior is essential to ensuring effectiveness of vector interventions.

Parasitism and the biodiversity-functioning relationship

Science.gov (United States)

Frainer, André; McKie, Brendan G.; Amundsen, Per-Arne; Knudsen, Rune; Lafferty, Kevin D.

2018-01-01

Biodiversity affects ecosystem functioning.Biodiversity may decrease or increase parasitism.Parasites impair individual hosts and affect their role in the ecosystem.Parasitism, in common with competition, facilitation, and predation, could regulate BD-EF relationships.Parasitism affects host phenotypes, including changes to host morphology, behavior, and physiology, which might increase intra- and interspecific functional diversity.The effects of parasitism on host abundance and phenotypes, and on interactions between hosts and the remaining community, all have potential to alter community structure and BD-EF relationships.Global change could facilitate the spread of invasive parasites, and alter the existing dynamics between parasites, communities, and ecosystems.Species interactions can influence ecosystem functioning by enhancing or suppressing the activities of species that drive ecosystem processes, or by causing changes in biodiversity. However, one important class of species interactions – parasitism – has been little considered in biodiversity and ecosystem functioning (BD-EF) research. Parasites might increase or decrease ecosystem processes by reducing host abundance. Parasites could also increase trait diversity by suppressing dominant species or by increasing within-host trait diversity. These different mechanisms by which parasites might affect ecosystem function pose challenges in predicting their net effects. Nonetheless, given the ubiquity of parasites, we propose that parasite–host interactions should be incorporated into the BD-EF framework.

How Many Parasites Species a Frog Might Have? Determinants of Parasite Diversity in South American Anurans.

Directory of Open Access Journals (Sweden)

Karla Magalhães Campião

Full Text Available There is an increasing interest in unveiling the dynamics of parasite infection. Understanding the interaction patterns, and determinants of host-parasite association contributes to filling knowledge gaps in both community and disease ecology. Despite being targeted as a relevant group for conservation efforts, determinants of the association of amphibians and their parasites in broad scales are poorly understood. Here we describe parasite biodiversity in South American amphibians, testing the influence of host body size and geographic range in helminth parasites species richness (PSR. We also test whether parasite diversity is related to hosts' phylogenetic diversity. Results showed that nematodes are the most common anuran parasites. Host-parasite network has a nested pattern, with specialist helminth taxa generally associated with hosts that harbour the richest parasite faunas. Host size is positively correlated with helminth fauna richness, but we found no support for the association of host geographic range and PSR. These results remained consistent after correcting for uneven study effort and hosts' phylogenic correlation. However, we found no association between host and parasite diversity, indicating that more diversified anuran clades not necessarily support higher parasite diversity. Overall, considering both the structure and the determinants of PRS in anurans, we conclude that specialist parasites are more likely to be associated with large anurans, which are the ones harbouring higher PSR, and that the lack of association of PSR with hosts' clade diversification suggests it is strongly influenced by ecological and contemporary constrains.

Geographical location and age affects the incidence of parasitic infestations in school children

Directory of Open Access Journals (Sweden)

Rayan Paran

2010-07-01

Full Text Available Environmental factors affect the dissemination and distribution of intestinal parasites in human communities. To comprehend the prevalence of parasitic infestation and to examine whether geographical location and age also influence the prevalence of infection, fecal samples from 195 school children (rural = 95; male = 39; female = 56 (urban = 100; male = 60; female = 40 of five age groups ranging from 5 to 11 years in two different socio-economic zones (rural and urban were screened for specific intestinal parasites using standard histological techniques. Percentage incidences of parasitic species found in fecal wet mounts and concentrates in rural children were Entamoeba coli (25.3%, Giardia lamblia (17.9%, Blastocystis hominis (14.7%, Entamoeba histolytica (4.2%, Iodamoeba butschlii (1.1%, Hymenolepis nana (1.1% and Ascaris lumbricoides (1.1%. Whereas the percentage incidences among urban children were E. coli (26%, A. lumbricoides (21%, B. hominis (18%, G. lamblia (14%, T. trichiura (8%, I. butschlii (4% and A. duodenale (1%. Such findings may be related to dietary differences, living conditions and the greater use of natural anti-helminthic medicinal plants in rural communities. These results are important for both epidemiological data collection and for correlating dietary differences to intestinal parasitic diseases. Aims: We chose to investigate whether geographical location and age affect the prevalence and distribution of intestinal parasites among school children from two separate regions (rural and urban in areas surrounding, Chennai, Tamil Nadu, India. Settings and Design: A study of the prevalence of parasitic infestations was undertaken among primary school children, in rural and urban communities around Chennai, Tamil Nadu, India. Materials and Methods: Faecal sample collection, direct microscopic techniques, macroscopic examination and concentration techniques for identifying the parasites. Statistical analysis used: Percentage

(macro- Evolutionary ecology of parasite diversity: From determinants of parasite species richness to host diversification

Directory of Open Access Journals (Sweden)

Serge Morand

2015-04-01

Full Text Available The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

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 ...

Neglected Parasitic Infections: Toxocariasis

Centers for Disease Control (CDC) Podcasts

2012-01-05

This podcast is an overview of the Clinician Outreach and Communication Activity (COCA) Call: Neglected Parasitic Infections in the United States. Neglected Parasitic Infections are a group of diseases that afflict vulnerable populations and are often not well studied or diagnosed. A subject matter expert from CDC's Division of Parasitic Diseases and Malaria describes the epidemiology, diagnosis, and treatment of toxocariasis.  Created: 1/5/2012 by Center for Global Health, Division of Parasitic Diseases and Malaria (DPDM); Emergency Risk Communication Branch (ERCB)/Joint Information Center (JIC), Office of Public Health Preparedness and Response (OPHPR).   Date Released: 1/9/2012.

Onchocerciasis in the Americas: from arrival to (near elimination

Directory of Open Access Journals (Sweden)

Sauerbrey Mauricio

2011-10-01

Full Text Available Abstract Onchocerciasis (river blindness is a blinding parasitic disease that threatens the health of approximately 120 million people worldwide. While 99% of the population at-risk for infection from onchocerciasis live in Africa, some 500,000 people in the Americas are also threatened by infection. A relatively recent arrival to the western hemisphere, onchocerciasis was brought to the New World through the slave trade and spread through migration. The centuries since its arrival have seen advances in diagnosing, mapping and treating the disease. Once endemic to six countries in the Americas (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela, onchocerciasis is on track for interruption of transmission in the Americas by 2012, in line with Pan American Health Organization resolution CD48.R12. The success of this public health program is due to a robust public-private partnership involving national governments, local communities, donor organizations, intergovernmental bodies, academic institutions, non-profit organizations and the pharmaceutical industry. The lessons learned through the efforts in the Americas are in turn informing the program to control and eliminate onchocerciasis in Africa. However, continued support and investment are needed for program implementation and post-treatment surveillance to protect the gains to-date and ensure complete elimination is achieved and treatment can be safely stopped within all 13 regional foci.

Using remote sensing and modeling techniques to investigate the annual parasite incidence of malaria in Loreto, Peru

Science.gov (United States)

Mousam, Aneela; Maggioni, Viviana; Delamater, Paul L.; Quispe, Antonio M.

2017-10-01

Between 2001 and 2010 significant progress was made towards reducing the number of malaria cases in Peru; however, the country saw an increase between 2011 and 2015. This work attempts to uncover the associations among various climatic and environmental variables and the annual malaria parasite incidence in the Peruvian region of Loreto. A Multilevel Mixed-effects Poisson Regression model is employed, focusing on the 2009-2013 period, when trends in malaria incidence shifted from decreasing to increasing. The results indicate that variations in elevation (β = 0.78; 95% confidence interval (CI), 0.75-0.81), soil moisture (β = 0.0021; 95% CI, 0.0019-0.0022), rainfall (β = 0.59; 95% CI, 0.56-0.61), and normalized difference vegetation index (β = 2.13; 95% CI, 1.83-2.43) is associated with higher annual parasite incidence, whereas an increase in temperature (β = -0.0043; 95% CI, - 0.0044- 0.0041) is associated with a lower annual parasite incidence. The results from this study are particularly useful for healthcare workers in Loreto and have the potential of being integrated within malaria elimination plans.

[Parasitic zoonoses transmitted by drinking water. Giardiasis and cryptosporidiosis].

Science.gov (United States)

Exner, M; Gornik, V

2004-07-01

Nowadays, the parasitic zoonose organisms Giardia lamblia und Cryptosporidium spp. are among the most relevant pathogens of drinking water-associated disease outbreaks. These pathogens are transmitted via a fecal-oral route; in both cases the dose of infection is low. Apart from person-to-person or animal-to-person transmissions, the consumption of contaminated food and water are further modes of transmission. The disease is mainly characterized by gastrointestinal symptoms. In industrialized countries, the prevalence rate of giardiasis is 2-5 % and of cryptosporidiosis 1-3%. Throughout the world, a large number of giardiasis and cryptosporidiosis outbreaks associated with drinking water were published; in 2001 the first case in Germany was identified. Giardia and Cryptosporidium are detected in surface water and sporadically in unprotected groundwater. Use of these waters for drinking water abstraction makes high demands on the technology of the treatment process: because of the disinfectant resistance of the parasites, safe elimination methods are needed, which even at high contamination levels of source water guarantee safe drinking water. Further measures for prevention and control are implementation of the HACCP concept, which includes the whole chain of procedures of drinking water supply from catchment via treatment to tap and a quality management system.

Eliminating armaments

International Nuclear Information System (INIS)

Adams, R.

1998-01-01

The end of Cold War induced optimistic projections concerning disarmament, elimination of nuclear weapons, elimination of massive inequities - poverty, hatred, racism. All these goals should be achieved simultaneously, but little has been achieved so far

Synchronised Voltage Space Vector Modulation for Three-level Inverters with Common-mode Voltage Elimination

DEFF Research Database (Denmark)

Oleschuk, Valentin; Blaabjerg, Frede

2002-01-01

A novel method of direct synchronous pulse-width modulation (PWM) is disseminated to three-level voltage source inverters with control algorithms with elimination of the common-mode voltages in three-phase drive systems with PWM. It provides smooth pulses-ratio changing and a quarter-wave symmetry...... of the voltage waveforms during the whole control range including overmodulation. Continuous, discontinuous and "direct-direct" schemes of synchronous PWM with both algebraic and trigonometric control functions have been analysed and compared. Simulations give the behaviour of the proposed methods and show some...... advantages of synchronous PWM in comparison with asynchronous at low ratios between the switching frequency and fundamental frequency....

Neglected Parasitic Infections: Toxocariasis

Centers for Disease Control (CDC) Podcasts

This podcast is an overview of the Clinician Outreach and Communication Activity (COCA) Call: Neglected Parasitic Infections in the United States. Neglected Parasitic Infections are a group of diseases that afflict vulnerable populations and are often not well studied or diagnosed. A subject matter expert from CDC's Division of Parasitic Diseases and Malaria describes the epidemiology, diagnosis, and treatment of toxocariasis.

A Spread Willingness Computing-Based Information Dissemination Model

Science.gov (United States)

Cui, Zhiming; Zhang, Shukui

2014-01-01

This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user's spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network. PMID:25110738

A Spread Willingness Computing-Based Information Dissemination Model

Directory of Open Access Journals (Sweden)

Haojing Huang

2014-01-01

Full Text Available This paper constructs a kind of spread willingness computing based on information dissemination model for social network. The model takes into account the impact of node degree and dissemination mechanism, combined with the complex network theory and dynamics of infectious diseases, and further establishes the dynamical evolution equations. Equations characterize the evolutionary relationship between different types of nodes with time. The spread willingness computing contains three factors which have impact on user’s spread behavior: strength of the relationship between the nodes, views identity, and frequency of contact. Simulation results show that different degrees of nodes show the same trend in the network, and even if the degree of node is very small, there is likelihood of a large area of information dissemination. The weaker the relationship between nodes, the higher probability of views selection and the higher the frequency of contact with information so that information spreads rapidly and leads to a wide range of dissemination. As the dissemination probability and immune probability change, the speed of information dissemination is also changing accordingly. The studies meet social networking features and can help to master the behavior of users and understand and analyze characteristics of information dissemination in social network.

Genome Evolution of Plant-Parasitic Nematodes.

Science.gov (United States)

Kikuchi, Taisei; Eves-van den Akker, Sebastian; Jones, John T

2017-08-04

Plant parasitism has evolved independently on at least four separate occasions in the phylum Nematoda. The application of next-generation sequencing (NGS) to plant-parasitic nematodes has allowed a wide range of genome- or transcriptome-level comparisons, and these have identified genome adaptations that enable parasitism of plants. Current genome data suggest that horizontal gene transfer, gene family expansions, evolution of new genes that mediate interactions with the host, and parasitism-specific gene regulation are important adaptations that allow nematodes to parasitize plants. Sequencing of a larger number of nematode genomes, including plant parasites that show different modes of parasitism or that have evolved in currently unsampled clades, and using free-living taxa as comparators would allow more detailed analysis and a better understanding of the organization of key genes within the genomes. This would facilitate a more complete understanding of the way in which parasitism has shaped the genomes of plant-parasitic nematodes.

Prevalence of intestinal parasites among workers involved in collection, transportation and recycling of wastes in the Pars Special Economic Energy Zone, Bushehr

Directory of Open Access Journals (Sweden)

MoradAli Fouladvand

2014-01-01

Full Text Available Abstract Background Intestinal parasitic infections are of one most important problems in developing countries and job is one of the most important factors determining the rate of intestinal parasitic infections. Persons who deal with waste elimination and recycling, due to close contact with infectious sources are more likely to be infected than others. Because of industrialization, population density and immigrants residing in Assaluyeh region , and due to the lack of history of a study for intestinal parasitic infection, the prevalence rate of intestinal parasitic infections among workers in the collection, transportation and recycling of wastes in the Pars Special Economic Energy Zone was evaluated. Material and methods: In a descriptive cross-sectional study, demographic questionaire was completed for each person, Stool samples were taken and sample containers were transferred to parasitology research laboratory of university. Samples were examined for intestinal parasites by preparing direct smear (wet mount and formalin-ether sedimentation technique. Data were collected by questionnaire and analyzed using SPSS 15.0 software and Chi square test. Results: The results showed that 37.3% of samples were infected at least with one intestinal parasite, 10.7% of samples were infected with more than one parasite. Giardia lamblia (6% and Entamoeba coli (13/4%, showed the highest infection rate among all parasite species. Prevalence rate of intestinal parasites in worker from Nakhl-e- Taghi municipality was higher than other region of the study area. Conclusion : Job type and duration of contact with infectious source play important roles in determining rate of intestinal parasitic infection. Workers involved in collection, transportation and recycling of wastes are more at risk of intestinal parasitic infections than others. Therfore, providing personal protective equipments and health education in this group can play an important role in community

Study on Dissemination Patterns in Location-Aware Gossiping Networks

Science.gov (United States)

Kami, Nobuharu; Baba, Teruyuki; Yoshikawa, Takashi; Morikawa, Hiroyuki

We study the properties of information dissemination over location-aware gossiping networks leveraging location-based real-time communication applications. Gossiping is a promising method for quickly disseminating messages in a large-scale system, but in its application to information dissemination for location-aware applications, it is important to consider the network topology and patterns of spatial dissemination over the network in order to achieve effective delivery of messages to potentially interested users. To this end, we propose a continuous-space network model extended from Kleinberg's small-world model applicable to actual location-based applications. Analytical and simulation-based study shows that the proposed network achieves high dissemination efficiency resulting from geographically neutral dissemination patterns as well as selective dissemination to proximate users. We have designed a highly scalable location management method capable of promptly updating the network topology in response to node movement and have implemented a distributed simulator to perform dynamic target pursuit experiments as one example of applications that are the most sensitive to message forwarding delay. The experimental results show that the proposed network surpasses other types of networks in pursuit efficiency and achieves the desirable dissemination patterns.

Parasitic diseases of lungs

International Nuclear Information System (INIS)

Rozenshtraukh, L.C.; Rybakova, N.I.; Vinner, M.G.

1987-01-01

Roentgenologic semiotics of the main parasitic diseases of lungs is described: echinococcosis, paragonimiasis, cysticercosis, toxoplasmosis, ascariasis, amebiosis and some rarely met parasitic diseases

[Anisakidosis a marine parasitic zoonosis: unknown or emerging in Peru?].

Science.gov (United States)

Cabrera, Rufino; Del Pilar, María; Altamirano, Trillo

2004-01-01

The purpose of this review is to show the experimental studies carried out on the biological cycle, culture, pathogenicity of the anisakidae nematode larvae and to disseminate the information regarding current epidemy and the probable emergence of anisakidosis in Peru, and in addition, to propose measures of prevention and control, as well as the perspective and need for investigation. The studies of experimental pathogenicity in cats, dos, and hamsters are incomplete. Eight cases of acute human anisakidosis have been reported (5 confirmed and 3 unconfirmed). It is probable that it emerges during the "El Niño" Weather Phenomenon; however, during normal conditions it is probably due to the increase of raw fish consumption and other factors. In the coast of Peru, five and four fishes of direct human consumption are parasited by the Anisakis simplex and Anisakis physeteris larva, respectively, and two fishes are parasited by the Pseudoterranova decipiens. The main host for the Anisakis simplex is the dolphin (Delphinus delphia), but the Contracaecum osculatum is hosted by the sea lion: Otaria byronia and Arctocephalus australis, P. decipiens parasita a O. byronia. Eviscerating the fish would be most adequate prevention method to lessen the risk of human infection. There is evidence that anisakidosis is an underestimated zoonosis in Peru, and that it is probably and emerging disease. Therefore, its presence is to be suspected in patients with the prototype clinical syndrome.

Evolution of diffusion and dissemination theory.

Science.gov (United States)

Dearing, James W

2008-01-01

The article provides a review and considers how the diffusion of innovations Research paradigm has changed, and offers suggestions for the further development of this theory of social change. Main emphases of diffusion Research studies are compared over time, with special attention to applications of diffusion theory-based concepts as types of dissemination science. A considerable degree of paradigmatic evolution is observed. The classical diffusion model focused on adopter innovativeness, individuals as the locus of decision, communication channels, and adoption as the primary outcome measures in post hoc observational study designs. The diffusion systems in question were centralized, with fidelity of implementation often assumed. Current dissemination Research and practice is better characterized by tests of interventions that operationalize one or more diffusion theory-based concepts and concepts from other change approaches, involve complex organizations as the units of adoption, and focus on implementation issues. Foment characterizes dissemination and implementation Research, Reflecting both its interdisciplinary Roots and the imperative of spreading evidence-based innovations as a basis for a new paradigm of translational studies of dissemination science.

Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees.

Science.gov (United States)

Huang, Qiang; Chen, Yan Ping; Wang, Rui Wu; Cheng, Shang; Evans, Jay D

2016-01-01

To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection.

Intracranial tumors with risk of dissemination in neuroaxis

International Nuclear Information System (INIS)

Calvo, F.A.; Hornedo, J.; de la Torre, A.; Sachetti, A.; Arellano, A.; Aramburo, P.; Aragon, G.; Otero, J.

1983-01-01

The experience of the Radiotherapy Service, Clinica Puerta de Hierro, Madrid (Spain), in the treatment of intracranial tumors with risk of neural axis dissemination is analyzed. In 15 years (1964 to 1979) 415 primary central nervous system tumors were studied and treated; 67 corresponded to tumors with risk of meningeal dissemination. Clinical dissemination in cerebrospinal fluid was proven in 14 patients. The actuarial survival of 10 years for patients with neural axis dissemination, without prophylactic treatment to the neuroaxis, is 14% with an average survival of 10.5 months. In approximately 20% of meduloblastomas, ependymal and pineal region tumors, meningeal metastases at some distance from the primary tumor can take place. Patients at risk with these types of neoplasia must be identified, ad an adequate radical therapeutic focus devised, not only for the primary tumor, but also for the risk of dissemination

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.

Transformerless photovoltaic inverters with leakage current and pulsating power elimination

DEFF Research Database (Denmark)

Tang, Yi; Yao, Wenli; Wang, H.

2015-01-01

This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV......-to-ground parasitic capacitance can be bypassed by introducing a common mode (CM) conducting path to the inverter. The resulting ground leakage current is therefore well controlled to be below the regulation limit. Moreover, the proposed inverter can also eliminate the well-known double line frequency pulsating power....... The mechanism of leakage current suppression and the closed-loop control of pulsating power decoupling are discussed in the paper in details. A 500 W prototype was also built and tested in the laboratory, and both simulation and experimental results are finally presented to show the excellent performance...

Current status of intestinal parasitic infections among inhabitants of the Ghazni and Parwan provinces, Afghanistan

Directory of Open Access Journals (Sweden)

Krzysztof Korzeniewski

2017-03-01

Full Text Available Background. The prevalence rates of food- and waterborne parasitic infections in Afghanistan are unknown. Cases of invasive diseases found in Afghans are rarely laboratory-confirmed. Objectives . The aim of the study was to present the current status of intestinal parasitic infections in Afghan inhabitants on the example of patients hospitalized in two healthcare facilities in eastern Afghanistan. Material and methods . Fecal samples were collected from 548 patients (children aged 1–17 years and adults with internal complaints, treated in Ghazni Provincial Hospital (Afghan civilian medical center, Ghazni province, 180 south-west of Kabul and in Bagram Korean Hospital (Korean military medical center for Afghan patients, Parwan province, 60 km north of Kabul between 2013 and 2014. One to three stool specimens from Afghan patients were fixed in 10% formalin, transported to the Military Institute of Medicine in Poland and tested by light microscopy using three diagnostic methods (direct smear in Lugol’s solution, decantation in distilled water and Fülleborn’s flotation. Results . Intestinal parasites were found in 144/386 of tested patients from the Ghazni province (37.3% infected, mainly with Ascaris lumbricoides , Giardia intestinalis , Hymenolepis nana and in 49/162 patients from the Parwan province (30.2% infected, mainly with G. intestinalis , A. lumbricoides , H. nana . Conclusions . The rates of intestinal parasitic infections among Afghans are high. The wide range of the detected parasites (protozoa, nematodes, cestodes should result in the introduction of general screening to be conducted regularly among inhabitants of Afghanistan and the application of targeted antiparasitic chemotherapy aiming to eliminate intestinal helminths and protozoa from the local community.

Clinical characteristics associated with the intracranial dissemination of gliomas.

Science.gov (United States)

Cai, Xu; Qin, Jun-Jie; Hao, Shu-Yu; Li, Huan; Zeng, Chun; Sun, Sheng-Jun; Yu, Lan-Bing; Gao, Zhi-Xian; Xie, Jian

2018-03-01

Glioma is the most common malignant tumor of the brain and the intracranial dissemination of gliomas is the late stage of the development of the tumor. However, there is little research in literature on the occurrence of intracranial dissemination of gliomas. In order to provide a reference for clinical work, we carried out this study on intracranial dissemination of glioma. A total of 629 patients with gliomas received tumor resection by the same surgeon from August 2010 to September 2015 were included in this study. The authors performed a retrospective review of the patients and the information regarding clinical features, histopathological results, molecular pathologic results and clinical outcomes was collected and analyzed. In this retrospective study, we found that the intracranial dissemination phenomenon occurred in 53 patients (8.43%). We analyzed the clinical characteristics of patients and found that the age at diagnosis (P = 0.011), WHO grade of the tumor (P dissemination. The higher grade of the tumor, the more prone to disseminate. Deletion of 1p/19q had no significant correlation with the intracranial dissemination. MMP9, Ki-67, and EGFR were highly expressed in tumor cells that caused dissemination, and the level of Ki-67 expression had significance in statistics (P 40 years), high pathological grade, invasion of the corpus callosum and high levels of Ki-67 expression were risk factors associated with the intracranial dissemination of gliomas. Copyright © 2018 Elsevier B.V. All rights reserved.

Financial and Economic Costs of the Elimination and Eradication of Onchocerciasis (River Blindness in Africa.

Directory of Open Access Journals (Sweden)

Young Eun Kim

Full Text Available Onchocerciasis (river blindness is a parasitic disease transmitted by blackflies. Symptoms include severe itching, skin lesions, and vision impairment including blindness. More than 99% of all cases are concentrated in sub-Saharan Africa. Fortunately, vector control and community-directed treatment with ivermectin have significantly decreased morbidity, and the treatment goal is shifting from control to elimination in Africa.We estimated financial resources and societal opportunity costs associated with scaling up community-directed treatment with ivermectin and implementing surveillance and response systems in endemic African regions for alternative treatment goals--control, elimination, and eradication. We used a micro-costing approach that allows adjustment for time-variant resource utilization and for the heterogeneity in the demographic, epidemiological, and political situation.The elimination and eradication scenarios, which include scaling up treatments to hypo-endemic and operationally challenging areas at the latest by 2021 and implementing intensive surveillance, would allow savings of $1.5 billion and $1.6 billion over 2013-2045 as compared to the control scenario. Although the elimination and eradication scenarios would require higher surveillance costs ($215 million and $242 million than the control scenario ($47 million, intensive surveillance would enable treatments to be safely stopped earlier, thereby saving unnecessary costs for prolonged treatments as in the control scenario lacking such surveillance and response systems.The elimination and eradication of onchocerciasis are predicted to allow substantial cost-savings in the long run. To realize cost-savings, policymakers should keep empowering community volunteers, and pharmaceutical companies would need to continue drug donation. To sustain high surveillance costs required for elimination and eradication, endemic countries would need to enhance their domestic funding capacity

Parasite prevalence corresponds to host life history in a diverse assemblage of afrotropical birds and haemosporidian parasites.

Directory of Open Access Journals (Sweden)

Holly L Lutz

Full Text Available Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified based on BLAST queries against the avian malaria database, MalAvi.

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.

Comprehensive analysis of information dissemination in disasters

Science.gov (United States)

Zhang, N.; Huang, H.; Su, Boni

2016-11-01

China is a country that experiences a large number of disasters. The number of deaths caused by large-scale disasters and accidents in past 10 years is around 900,000. More than 92.8 percent of these deaths could be avoided if there were an effective pre-warning system deployed. Knowledge of the information dissemination characteristics of different information media taking into consideration governmental assistance (information published by a government) in disasters in urban areas, plays a critical role in increasing response time and reducing the number of deaths and economic losses. In this paper we have developed a comprehensive information dissemination model to optimize efficiency of pre-warning mechanics. This model also can be used for disseminating information for evacuees making real-time evacuation plans. We analyzed every single information dissemination models for pre-warning in disasters by considering 14 media: short message service (SMS), phone, television, radio, news portals, Wechat, microblogs, email, newspapers, loudspeaker vehicles, loudspeakers, oral communication, and passive information acquisition via visual and auditory senses. Since governmental assistance is very useful in a disaster, we calculated the sensitivity of governmental assistance ratio. The results provide useful references for information dissemination during disasters in urban areas.

Host-Parasite Interactions and Purifying Selection in a Microsporidian Parasite of Honey Bees.

Directory of Open Access Journals (Sweden)

Qiang Huang

Full Text Available To clarify the mechanisms of Nosema ceranae parasitism, we deep-sequenced both honey bee host and parasite mRNAs throughout a complete 6-day infection cycle. By time-series analysis, 1122 parasite genes were significantly differently expressed during the reproduction cycle, clustering into 4 expression patterns. We found reactive mitochondrial oxygen species modulator 1 of the host to be significantly down regulated during the entire infection period. Our data support the hypothesis that apoptosis of honey bee cells was suppressed during infection. We further analyzed genome-wide genetic diversity of this parasite by comparing samples collected from the same site in 2007 and 2013. The number of SNP positions per gene and the proportion of non-synonymous substitutions per gene were significantly reduced over this time period, suggesting purifying selection on the parasite genome and supporting the hypothesis that a subset of N. ceranae strains might be dominating infection.

Multi-Scale Dissemination of Time Series Data

DEFF Research Database (Denmark)

Guo, Qingsong; Zhou, Yongluan; Su, Li

2013-01-01

In this paper, we consider the problem of continuous dissemination of time series data, such as sensor measurements, to a large number of subscribers. These subscribers fall into multiple subscription levels, where each subscription level is specified by the bandwidth constraint of a subscriber......, which is an abstract indicator for both the physical limits and the amount of data that the subscriber would like to handle. To handle this problem, we propose a system framework for multi-scale time series data dissemination that employs a typical tree-based dissemination network and existing time...

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 OF FISH

Science.gov (United States)

The intent of this chapter is to describe the parasites of importance to fishes maintained and used in laboratory settings. In contrast to the frist edition, the focus will be only on those parasites that pose a serious threat to or are common in fishes held in these confined en...

Reduced helminth parasitism in the introduced bank vole (Myodes glareolus: More parasites lost than gained

Directory of Open Access Journals (Sweden)

Karen C. Loxton

2016-08-01

Full Text Available Introduced species are often less parasitised compared to their native counterparts and to ecologically similar hosts in the new environment. Reduced parasitism may come about due to both the loss of original parasites and low acquisition of novel parasites. In this study we investigated the intestinal helminth parasites of the introduced bank vole (Myodes glareolus in Ireland. Results were compared to data from other European studies and to the intestinal helminth fauna of an ecologically similar native rodent in Ireland, the wood mouse (Apodemus sylvaticus. The helminth fauna of introduced bank voles exhibited low diversity with only 3 species recovered: Aspiculuris tianjinensis; Aonchotheca murissylvatici and Taenia martis larvae. In particular, no adult parasites with indirect life-cycles were found in bank voles suggesting that indirectly transmitted parasites are less likely to establish in invasive hosts. Also, the results of this study add support to the enemy release hypothesis.

Parasites and immunotherapy: with or against?

Science.gov (United States)

Yousofi Darani, Hossein; Yousefi, Morteza; Safari, Marzieh; Jafari, Rasool

2016-06-01

Immunotherapy is a sort of therapy in which antibody or antigen administrates to the patient in order to treat or reduce the severity of complications of disease. This kind of treatment practiced in a wide variety of diseases including infectious diseases, autoimmune disorders, cancers and allergy. Successful and unsuccessful immunotherapeutic strategies have been practiced in variety of parasitic infections. On the other hand parasites or parasite antigens have also been considered for immunotherapy against other diseases such as cancer, asthma and multiple sclerosis. In this paper immunotherapy against common parasitic infections, and also immunotherapy of cancer, asthma and multiple sclerosis with parasites or parasite antigens have been reviewed.

Parasitic worms: how many really?

Science.gov (United States)

Strona, Giovanni; Fattorini, Simone

2014-04-01

Accumulation curves are useful tools to estimate species diversity. Here we argue that they can also be used in the study of global parasite species richness. Although this basic idea is not completely new, our approach differs from the previous ones as it treats each host species as an independent sample. We show that randomly resampling host-parasite records from the existing databases makes it possible to empirically model the relationship between the number of investigated host species, and the corresponding number of parasite species retrieved from those hosts. This method was tested on 21 inclusive lists of parasitic worms occurring on vertebrate hosts. All of the obtained models conform well to a power law curve. These curves were then used to estimate global parasite species richness. Results obtained with the new method suggest that current predictions are likely to severely overestimate parasite diversity. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

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.

44 CFR 19.140 - Dissemination of policy.

Science.gov (United States)

2010-10-01

... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 19.140 Dissemination of policy. (a... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Dissemination of policy. 19.140 Section 19.140 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

Parasite specialization in a unique habitat: hummingbirds as reservoirs of generalist blood parasites of Andean birds.

Science.gov (United States)

Moens, Michaël A J; Valkiūnas, Gediminas; Paca, Anahi; Bonaccorso, Elisa; Aguirre, Nikolay; Pérez-Tris, Javier

2016-09-01

Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence. We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity. We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds. Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species. Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and

Prevalence of Intestinal Parasitic Infections and their Association with Nutritional Status of Rural and Urban Pre-School Children in Benue State, Nigeria.

Science.gov (United States)

Tyoalumun, Kpurkpur; Abubakar, Sani; Christopher, Nongu

2016-01-01

Intestinal parasitic infections are highly prevalent in developing countries, contributing to high incidence of malnutrition and morbidity. This study aimed to find the prevalence of intestinal parasitic infections and their association with nutritional status of children in Benue State, Nigeria. A cross sectional study conducted from January-June 2016, among 418 school children under-5 years of age. Anthropometric data, height-for-age, weight-for-height, and weight-for-age Z-scores from each child and fecal samples were collected and screened for intestinal parasites using standard laboratory methods. Among the intestinal parasitic infections detected, the prevalence of E. histolytica was higher (51.0% and 29.0%) than all other parasites encountered in rural and urban pupils (Prural and urban pupils were 43.8% and 32.9%; 64.4% and 39.0% rural and urban pupils were underweight (WAZ<-2), while 30.3% and 24.3% were wasted (WHZ<-2). Infected children had significantly (P<0.05) higher z-scores than the uninfected children. Benue State is among the Nigerian states with the highest burden of tropical diseases with a current plan of elimination implemented through mass drug administration. This study identify/evaluate some essential information that will support the planning and implementation of the State's ongoing efforts.

Asymptomatic Malaria and its Challenges in the Malaria Elimination Program in Iran: a Systematic Review

Directory of Open Access Journals (Sweden)

Gholmreza Hassanpour

2017-06-01

Full Text Available Background: The ob­jective of this study was to find an appropriate approach to asymptomatic malaria in elimination setting through a systematic review.Methods: A broad search was conducted to find articles with the words ‘malaria’ in their titles and ‘asymptomatic’ or ‘submicroscopic’ in their texts, irrespective of the type of study conducted. The Cochrane, Medline/PubMed, and Scopus databases, as well as Google Scholar were systematically searched for English articles and reports and Iran’s databases- IranMedex, SID and Magiran were searched for Persian reports and articles, with no time limitation. The study was qualitatively summarized if it contained precise information on the role of asymptomatic malaria in the elimination phase.Results: Six articles were selected from the initial 2645 articles. The results all re-emphasize the significance of asymptomatic malaria in the elimination phase, and empha­size the significance of diagnostic tests of higher sensitivity to locate these patients and perform interventions to re­duce the asymptomatic parasitic reservoirs particularly in regions of low transmission. However, we may infer from the results that the current evidence cannot yet specify an accurate strategy on the role of asymptomatic malaria in the elimination phase.Conclusion: To eliminate malaria, alongside vector control, and treatment of symptomatic and asymptomatic pa­tients, active and inactive methods of case detection need to be employed. The precise monitoring of asymptomatic individuals and submicroscopic cases of malaria through molecular assays and valid serological methods, especially in regions where seasonal and low transmission exists can be very helpful at this phase.

Immunity to parasitic infection

National Research Council Canada - National Science Library

Lamb, Tracey J

2012-01-01

.... Often endemic in developing countries many parasitic diseases are neglected in terms of research funding and much remains to be understood about parasites and the interactions they have with the immune system...

Immunity to parasitic infection

National Research Council Canada - National Science Library

Lamb, Tracey J

2012-01-01

... may be manipulated to develop therapeutic interventions against parasitic infection. For easy reference, the most commonly studied parasites are examined in individual chapters written by investigators at the forefront of their field...

48 CFR 3052.242-71 - Dissemination of contract information.

Science.gov (United States)

2010-10-01

... CONTRACT CLAUSES Text of Provisions and Clauses 3052.242-71 Dissemination of contract information. As prescribed in (HSAR) 48 CFR 3042.202-70, insert the following clause: Dissemination of Contract Information... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Dissemination of contract...

48 CFR 1252.242-72 - Dissemination of contract information.

Science.gov (United States)

2010-10-01

....242-72 Dissemination of contract information. As prescribed in (TAR) 48 CFR 1242.7000(c), insert the following clause: Dissemination of Contract Information (OCT 1994) The Contractor shall not publish, permit... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Dissemination of contract...

9 CFR 381.88 - Parasites.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Parasites. 381.88 Section 381.88 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY... § 381.88 Parasites. Organs or other parts of carcasses which are found to be infested with parasites, or...

Parasitic infections of the external eye.

Science.gov (United States)

Pahuja, Shivani; Puranik, Charuta; Jelliti, Bechir; Khairallah, Moncef; Sangwan, Virender S

2013-08-01

To review the published literature on parasitic infections of external eye. Published articles and case reports on parasitic infections of external eye were reviewed and relevant information was collected. Parasitic infections of the eye are rare. However, being more commonly seen in developing nations, they require active measures for screening, diagnosis, and therapy. Parasites of importance causing external ocular disease are protozoan parasites, such as Leishmania; metazoans, such as nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms); or ectoparasites, such as Phthirus pubis and Demodex.

The bigger, the better? Volume measurements of parasites and hosts: Parasitic barnacles (Cirripedia, Rhizocephala and their decapod hosts.

Directory of Open Access Journals (Sweden)

Christina Nagler

Full Text Available Rhizocephala, a group of parasitic castrators of other crustaceans, shows remarkable morphological adaptations to their lifestyle. The adult female parasite consists of a body that can be differentiated into two distinct regions: a sac-like structure containing the reproductive organs (the externa, and a trophic, root like system situated inside the hosts body (the interna. Parasitism results in the castration of their hosts, achieved by absorbing the entire reproductive energy of the host. Thus, the ratio of the host and parasite sizes is crucial for the understanding of the parasite's energetic cost. Using advanced imaging methods (micro-CT in conjunction with 3D modeling, we measured the volume of parasitic structures (externa, interna, egg mass, egg number, visceral mass and the volume of the entire host. Our results show positive correlations between the volume of (1 entire rhizocephalan (externa + interna and host body, (2 rhizocephalan externa and host body, (3 rhizocephalan visceral mass and rhizocephalan body, (4 egg mass and rhizocephalan externa, (5 rhizocephalan egg mass and their egg number. Comparing the rhizocephalan Sylon hippolytes, a parasite of caridean shrimps, and representatives of Peltogaster, parasites of hermit crabs, we could match their different traits on a reconstructed relationship. With this study we add new and significant information to our global understanding of the evolution of parasitic castrators, of interactions between a parasitic castrator and its host and of different parasitic strategies within parasitic castrators exemplified by rhizocephalans.

The role of moulting in parasite defence.

Science.gov (United States)

Duneau, David; Ebert, Dieter

2012-08-07

Parasitic infections consist of a succession of steps during which hosts and parasites interact in specific manners. At each step, hosts can use diverse defence mechanisms to counteract the parasite's attempts to invade and exploit them. Of these steps, the penetration of parasites into the host is a key step for a successful infection and the epithelium is the first line of host defence. The shedding of this protective layer (moulting) is a crucial feature in the life cycle of several invertebrate and vertebrate taxa, and is generally considered to make hosts vulnerable to parasites and predators. Here, we used the crustacean Daphnia magna to test whether moulting influences the likelihood of infection by the castrating bacterium Pasteuria ramosa. This parasite is known to attach to the host cuticula before penetrating into its body. We found that the likelihood of successful parasite infection is greatly reduced if the host moults within 12 h after parasite exposure. Thus, moulting is beneficial for the host being exposed to this parasite. We further show that exposure to the parasite does not induce hosts to moult earlier. We discuss the implications of our findings for host and parasite evolution and epidemiology.

RNA trafficking in parasitic plant systems

Science.gov (United States)

LeBlanc, Megan; Kim, Gunjune; Westwood, James H.

2012-01-01

RNA trafficking in plants contributes to local and long-distance coordination of plant development and response to the environment. However, investigations of mobile RNA identity and function are hindered by the inherent difficulty of tracing a given molecule of RNA from its cell of origin to its destination. Several methods have been used to address this problem, but all are limited to some extent by constraints associated with accurately sampling phloem sap or detecting trafficked RNA. Certain parasitic plant species form symplastic connections to their hosts and thereby provide an additional system for studying RNA trafficking. The haustorial connections of Cuscuta and Phelipanche species are similar to graft junctions in that they are able to transmit mRNAs, viral RNAs, siRNAs, and proteins from the host plants to the parasite. In contrast to other graft systems, these parasites form connections with host species that span a wide phylogenetic range, such that a high degree of nucleotide sequence divergence may exist between host and parasites and allow confident identification of most host RNAs in the parasite system. The ability to identify host RNAs in parasites, and vice versa, will facilitate genomics approaches to understanding RNA trafficking. This review discusses the nature of host–parasite connections and the potential significance of host RNAs for the parasite. Additional research on host–parasite interactions is needed to interpret results of RNA trafficking studies, but parasitic plants may provide a fascinating new perspective on RNA trafficking. PMID:22936942

RNA trafficking in parasitic plant systems

Directory of Open Access Journals (Sweden)

Megan L LeBlanc

2012-08-01

Full Text Available RNA trafficking in plants contributes to local and long-distance coordination of plant development and response to the environment. However, investigations of mobile RNA identity and function are hindered by the inherent difficulty of tracing a given molecule of RNA from its cell of origin to its destination. Several methods have been used to address this problem, but all are limited to some extent by constraints associated with accurately sampling phloem sap or detecting trafficked RNA. Certain parasitic plant species form symplastic connections to their hosts and thereby provide an additional system for studying RNA trafficking. The haustorial connections of Cuscuta and Phelipanche species are similar to graft junctions in that they are able to transmit mRNAs, viral RNAs, siRNAs and proteins from the host plants to the parasite. In contrast to other graft systems, these parasites form connections with host species that span a wide phylogenetic range, such that a high degree of nucleotide sequence divergence may exist between host and parasites and allow confident identification of most host RNAs in the parasite system. The ability to identify host RNAs in parasites, and vice versa, will facilitate genomics approaches to understanding RNA trafficking. This review discusses the nature of host parasite connections and the potential significance of host RNAs for the parasite. Additional research on host-parasite interactions is needed to interpret results of RNA trafficking studies, but parasitic plants may provide a fascinating new perspective on RNA trafficking.

Maternal androgens in avian brood parasites and their hosts: responses to parasitism and competition?

Science.gov (United States)

Hahn, Caldwell; Wingfield, John C.; Fox, David M.; Walker, Brian G.; Thomley, Jill E

2017-01-01

In the coevolutionary dynamic of avian brood parasites and their hosts, maternal (or transgenerational) effects have rarely been investigated. We examined the potential role of elevated yolk testosterone in eggs of the principal brood parasite in North America, the brown-headed cowbird, and three of its frequent host species. Elevated maternal androgens in eggs are a common maternal effect observed in many avian species when breeding conditions are unfavorable. These steroids accelerate embryo development, shorten incubation period, increase nestling growth rate, and enhance begging vigor, all traits that can increase the survival of offspring. We hypothesized that elevated maternal androgens in host eggs are a defense against brood parasitism. Our second hypothesis was that elevated maternal androgens in cowbird eggs are a defense against intra-specific competition. For host species, we found that elevated yolk testosterone was correlated with parasitized nests of small species, those whose nest success is most reduced by cowbird parasitism. For cowbirds, we found that elevated yolk testosterone was correlated with eggs in multiply-parasitized nests, which indicate intra-specific competition for nests due to high cowbird density. We propose experimental work to further examine the use of maternal effects by cowbirds and their hosts.

Women and Parasitic Diseases

Science.gov (United States)

... Consultations, and General Public. Contact Us Parasites Home Women Recommend on Facebook Tweet Share Compartir Infection with ... of parasites can lead to unique consequences for women. Some examples are given below. Infection with Toxoplasma ...

21 CFR 99.101 - Information that may be disseminated.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Information that may be disseminated. 99.101 Section 99.101 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Information To Be Disseminated § 99.101 Information that may be disseminated. (a) A manufacturer may...

Gossip-Based Dissemination

Science.gov (United States)

Friedman, Roy; Kermarrec, Anne-Marie; Miranda, Hugo; Rodrigues, Luís

Gossip-based networking has emerged as a viable approach to disseminate information reliably and efficiently in large-scale systems. Initially introduced for database replication [222], the applicability of the approach extends much further now. For example, it has been applied for data aggregation [415], peer sampling [416] and publish/subscribe systems [845]. Gossip-based protocols rely on a periodic peer-wise exchange of information in wired systems. By changing the way each peer is selected for the gossip communication, and which data are exchanged and processed [451], gossip systems can be used to perform different distributed tasks, such as, among others: overlay maintenance, distributed computation, and information dissemination (a collection of papers on gossip can be found in [451]). In a wired setting, the peer sampling service, allowing for a random or specific peer selection, is often provided as an independent service, able to operate independently from other gossip-based services [416].

The Plasmodium PI(4)K inhibitor KDU691 selectively inhibits dihydroartemisinin-pretreated Plasmodium falciparum ring-stage parasites.

Science.gov (United States)

Dembele, L; Ang, X; Chavchich, M; Bonamy, G M C; Selva, J J; Lim, M Yi-Xiu; Bodenreider, C; Yeung, B K S; Nosten, F; Russell, B M; Edstein, M D; Straimer, J; Fidock, D A; Diagana, T T; Bifani, P

2017-05-24

Malaria control and elimination are threatened by the emergence and spread of resistance to artemisinin-based combination therapies (ACTs). Experimental evidence suggests that when an artemisinin (ART)-sensitive (K13 wild-type) Plasmodium falciparum strain is exposed to ART derivatives such as dihydroartemisinin (DHA), a small population of the early ring-stage parasites can survive drug treatment by entering cell cycle arrest or dormancy. After drug removal, these parasites can resume growth. Dormancy has been hypothesized to be an adaptive physiological mechanism that has been linked to recrudescence of parasites after monotherapy with ART and, possibly contributes to ART resistance. Here, we evaluate the in vitro drug sensitivity profile of normally-developing P. falciparum ring stages and DHA-pretreated dormant rings (DP-rings) using a panel of antimalarial drugs, including the Plasmodium phosphatidylinositol-4-OH kinase (PI4K)-specific inhibitor KDU691. We report that while KDU691 shows no activity against rings, it is highly inhibitory against DP-rings; a drug effect opposite to that of ART. Moreover, we provide evidence that KDU691 also kills DP-rings of P. falciparum ART-resistant strains expressing mutant K13.

Early dissemination seeds metastasis in breast cancer

Science.gov (United States)

Hosseini, Hedayatollah; Obradović, Milan M.S.; Hoffmann, Martin; Harper, Kathryn; Sosa, Maria Soledad; Werner-Klein, Melanie; Nanduri, Lahiri Kanth; Werno, Christian; Ehrl, Carolin; Maneck, Matthias; Patwary, Nina; Haunschild, Gundula; Gužvić, Miodrag; Reimelt, Christian; Grauvogl, Michael; Eichner, Norbert; Weber, Florian; Hartkopf, Andreas; Taran, Florin-Andrei; Brucker, Sara Y.; Fehm, Tanja; Rack, Brigitte; Buchholz, Stefan; Spang, Rainer; Meister, Gunter; Aguirre-Ghiso, Julio A.; Klein, Christoph A.

2016-01-01

Accumulating data suggest that metastatic dissemination often occurs early during tumour formation but the mechanisms of early metastatic spread have not yet been addressed. Here, we studied metastasis in a HER2-driven mouse breast cancer model and found that progesterone-induced signalling triggered migration of cancer cells from early lesions shortly after HER2 activation, but promoted proliferation in advanced primary tumour cells. The switch from migration to proliferation was regulated by elevated HER2 expression and increased tumour cell density involving miRNA-mediated progesterone receptor (PGR) down-regulation and was reversible. Cells from early, low-density lesions displayed more stemness features than cells from dense, advanced tumours, migrated more and founded more metastases. Strikingly, we found that at least 80% of metastases were derived from early disseminated cancer cells (DCC). Karyotypic and phenotypic analysis of human disseminated cancer cells and primary tumours corroborated the relevance of these findings for human metastatic dissemination. PMID:27974799

Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants

Directory of Open Access Journals (Sweden)

Muhammad A. Ali

2017-10-01

Full Text Available Nematodes are omnipresent in nature including many species which are parasitic to plants and cause enormous economic losses in various crops. During the process of parasitism, sedentary phytonematodes use their stylet to secrete effector proteins into the plant cells to induce the development of specialized feeding structures. These effectors are used by the nematodes to develop compatible interactions with plants, partly by mimicking the expression of host genes. Intensive research is going on to investigate the molecular function of these effector proteins in the plants. In this review, we have summarized which physiological and molecular changes occur when endoparasitic nematodes invade the plant roots and how they develop a successful interaction with plants using the effector proteins. We have also mentioned the host genes which are induced by the nematodes for a compatible interaction. Additionally, we discuss how nematodes modulate the reactive oxygen species (ROS and RNA silencing pathways in addition to post-translational modifications in their own favor for successful parasitism in plants.

Optimal channel choice for collaborative ad-hoc dissemination

DEFF Research Database (Denmark)

Hu, Liang; Boudec, J-Y. L.; Vojnovic, M.

2010-01-01

Collaborative ad-hoc dissemination of information has been proposed as an efficient means to disseminate information among devices in a wireless ad-hoc network. Devices help in forwarding the information channels to the entire network, by disseminating the channels they subscribe to, plus others...... by a Metropolis-Hastings sampling algorithm. We also give a variant that accounts for battery level. This leads to a practical channel selection and re-selection algorithm that can be implemented without any central control....

Dissemination and Exploitation: Project Goals beyond Science

Science.gov (United States)

Hamann, Kristin; Reitz, Anja

2017-04-01

Dissemination and Exploitation are essential parts of public funded projects. In Horizon 2020 a plan for the exploitation and dissemination of results (PEDR) is a requirement. The plan should contain a clear vision on the objectives of the project in relation to actions for dissemination and potential exploitation of the project results. The actions follow the basic idea to spread the knowledge and results gathered within the project and face the challenge of how to bring the results into potentially relevant policy circle and how they impact the market. The plan follows the purpose to assess the impact of the project and to address various target groups who are interested in the project results. Simply put, dissemination concentrates on the transfer of knowledge and exploitation on the commercialization of the project. Beyond the question of the measurability of project`s impact, strategies within science marketing can serve purposes beyond internal and external communication. Accordingly, project managers are facing the challenge to implement a dissemination and exploitation strategy that ideally supports the identification of all partners with the project and matches the current discourse of the project`s content within the society, politics and economy. A consolidated plan might unite all projects partners under a central idea and supports the identification with the project beyond the individual research questions. Which applications, strategies and methods can be used to bring forward a PEDR that accompanies a project successfully and allows a comprehensive assessment of the project afterwards? Which hurdles might project managers experience in the dissemination process and which tasks should be fulfilled by the project manager?

Nuclear hormone receptors in parasitic helminths

OpenAIRE

Wu, Wenjie; LoVerde, Philip T

2010-01-01

Nuclear receptors (NRs) belong to a large protein superfamily that are important transcriptional modulators in metazoans. Parasitic helminths include parasitic worms from the Lophotrochozoa (Platyhelminths) and Ecdysozoa (Nematoda). NRs in parasitic helminths diverged into two different evolutionary lineages. NRs in parasitic Platyhelminths have orthologues in Deuterostomes, in arthropods or both with a feature of extensive gene loss and gene duplication within different gene groups. NRs in p...

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.

Detection of Leishmania RNA virus in Leishmania parasites.

Directory of Open Access Journals (Sweden)

Haroun Zangger

Full Text Available Patients suffering from cutaneous leishmaniasis (CL caused by New World Leishmania (Viannia species are at high risk of developing mucosal (ML or disseminated cutaneous leishmaniasis (DCL. After the formation of a primary skin lesion at the site of the bite by a Leishmania-infected sand fly, the infection can disseminate to form secondary lesions. This metastatic phenotype causes significant morbidity and is often associated with a hyper-inflammatory immune response leading to the destruction of nasopharyngeal tissues in ML, and appearance of nodules or numerous ulcerated skin lesions in DCL. Recently, we connected this aggressive phenotype to the presence of Leishmania RNA virus (LRV in strains of L. guyanensis, showing that LRV is responsible for elevated parasitaemia, destructive hyper-inflammation and an overall exacerbation of the disease. Further studies of this relationship and the distribution of LRVs in other Leishmania strains and species would benefit from improved methods of viral detection and quantitation, especially ones not dependent on prior knowledge of the viral sequence as LRVs show significant evolutionary divergence.This study reports various techniques, among which, the use of an anti-dsRNA monoclonal antibody (J2 stands out for its specific and quantitative recognition of dsRNA in a sequence-independent fashion. Applications of J2 include immunofluorescence, ELISA and dot blot: techniques complementing an arsenal of other detection tools, such as nucleic acid purification and quantitative real-time-PCR. We evaluate each method as well as demonstrate a successful LRV detection by the J2 antibody in several parasite strains, a freshly isolated patient sample and lesion biopsies of infected mice.We propose that refinements of these methods could be transferred to the field for use as a diagnostic tool in detecting the presence of LRV, and potentially assessing the LRV-related risk of complications in cutaneous leishmaniasis.

Leukoreduction by centrifugation does not eliminate Trypanosoma cruzi from infected blood units.

Science.gov (United States)

Dzib, Doris; Hernández, Virginia Peña; Ake, Baldemar Canche; López, Ruth Alacantara; Monteón, Victor Manuel

2009-06-01

Current strategies to prevent transfusion-associated Chagas disease include the identification of Trypanosoma cruzi-infected blood donors through questionnaires and serologic tests. There are other procedures such as leukoreduction that prevent the transmission of infectious agents associated to white cells. The objective of the present work was to estimate the seroprevalence, evaluate the efficacy of leukoreduction by centrifugation to eliminate T. cruzi in infected blood units, and the correlation of immunoglobulin G (IgG) subclasses of seropositive blood donors with chronic chagasic cardiopathy. Over a period of 14 months, 33 out of 6600 blood donors (0.5%) at Centro Estatal de la Transfusión Sanguínea in Campeche State, México were seropositive for T. cruzi. Twenty seropositive blood units were submitted through leukoreduction by centrifugation, and in the fractions generated (red cell fraction, platelets, and the buffy-coat), we searched for the presence of T. cruzi using specific polymerase chain reaction. We detected parasite DNA in 50% to 60% of the fractions tested, suggesting that leukoreduction by centrifugation does not eliminate the microorganisms in the infected blood unit. We also observed that the level of IgG2 and IgG4 subclasses specific for T. cruzi in seropositive blood donors was lower than in chronic cardiopathic chagasic patients. In conclusion, leukoreduction by centrifugation has a limited role in eliminating T. cruzi in infected blood supply, and the low level of specific IgG2 and IgG4 could be a marker in the indeterminate phase of infection.

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

Science.gov (United States)

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

Quantifying anuran microhabitat use to infer the potential for parasite transmission between invasive cane toads and two species of Australian native frogs.

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Lígia Pizzatto

Full Text Available Parasites that are carried by invasive species can infect native taxa, with devastating consequences. In Australia, invading cane toads (Rhinella marina carry lungworm parasites (Rhabdias pseudosphaerocephala that (based on previous laboratory studies can infect native treefrogs (Litoria caerulea and L. splendida. To assess the potential of parasite transmission from the invader to the native species (and from one infected native frog to another, we used surveys and radiotelemetry to quantify anuran microhabitat use, and proximity to other anurans, in two sites in tropical Australia. Unsurprisingly, treefrogs spent much of their time off the ground (especially by day, and in undisturbed forests but terrestrial activity was common at night (especially in anthropogenically modified habitats. Microhabitat overlap between cane toads and frogs was generally low, except at night in disturbed areas, whereas overlap between the two frog species was high. The situations of highest overlap, and hence with the greatest danger of parasite transmission, involve aggregations of frogs within crevices by day, and use of open ground by all three anuran species at night. Overall, microhabitat divergence between toads and frogs should reduce, but not eliminate, the transmission of lungworms from invasive toads to vulnerable native frogs.

Effective Dissemination - Building an 'Evidence to Impact' Strategy

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Dan O'Neill

2017-02-01

Full Text Available When a piece of ‘evidence’ is generated in the research environment and almost nobody hears about it, then can we really still call it a piece of ‘evidence’? Does evidence only become evidence once it is used; and until then, is it just a piece of insignificant information? As we inexorably travel through the EBVM era, we must increasingly prioritise effective dissemination of evidence. This paper will use the VetCompass Programme at the Royal Veterinary College as a case study to explore a strategic dissemination plan and examine routes for effective dissemination.Although EBVM traditionally assumes an audience of academics or practicing veterinarians, the authors contend that substantial welfare gains can be additionally achieved by targeting current and future pet owners, the non-owner general public, industry, welfare bodies, scientific groups, breeders and kennel clubs. Effective dissemination should be strategic and give a priori consideration to identifying target audiences, appropriate formatting of the messages and open access routes for dissemination. Scientists who generate EBVM may not always be best placed to also disseminate these messages and therefore research teams should consider widening their combined skill-base to also incorporate marketing and media savvy.The VetCompass Programme is a new and hugely exciting project that shares de-identified primary-practice clinical data for research to support effective evidence based veterinary medicine and welfare reforms. VetCompass data collection commenced in 2009 and the current 470 collaborating primary-care practices have shared data on 4 million small animals and 45 million unique episodes of care. VetCompass has 15 peer-reviewed publications to date.In order to maximise the welfare gains from an array of evidence silos generated within VetCompass, a dissemination strategy was designed based on a Systems Thinking approach. The outcomes from a range of dissemination trials

Introduction of New Parasites in Denmark

DEFF Research Database (Denmark)

Enemark, Heidi L.

examples of such parasites/parasitic diseases: Setaria tundra, a mosquito-borne filarioid nematode which was detected for the first time in Danish deer in 2010. This parasite is usually considered harmless but is capable of causing peritonitis and mortality in ungulates. The newly detected parasite...... was genetically very similar to previously published isolates from France and Italy, and may have been spread to Denmark from southern Europe. Giardia spp. a zoonotic, unicellular parasite (protozoa) well known in Danish livestock but recently found in extremely high numbers in Danish deer with chronic diarrhea...... for the first time in Denmark approximately 10 years ago in 3 foxes from the Copenhagen area. Since then, no systematic surveillance has been performed, and therefore the current prevalence among wildlife and pets is unknown. So far the parasite has not been found in intermediate hosts (rodents) in Denmark...

Elimination reactions. V. Steric effects in Hofmann elimination

International Nuclear Information System (INIS)

Coke, J.L.; Smith, G.D.; Britton, G.H. Jr.

1975-01-01

Earlier Hofmann elimination studies were extended, and the percent syn eliminations in several ring systems have been correlated using cis-d 1 and trans-d 1 models. The measurements of several syn and anti k/sub H//k/sub D/ kinetic isotope effects are reported. Results indicate that Hofmann elimination of N,N,N-trimethyl-3,3-dimethylcyclopentylammonium hydroxide goes by 97 percent syn mechanism to give 3,3-dimethylcyclopentene and by 70 + - 6 percent syn mechanism to give 4,4-dimethylcyclopentene. There appears to be severe steric interactions in the anti mechanism in the 3,3-dimethylcyclopentyl system. Results indicate that, for Hofmann pyrolysis of trimethylammonium hydroxides, cyclopentene is formed by a 39 +- 7 percent syn mechanism, cyclohexene is formed by a 2 + - 2 percent syn mechanism, and cycloheptene is formed by a 30 +- 2 percent syn mechanism. Steric effects on isotope effects and mechanisms are discussed. (U.S.)

Intestinal parasites in paper money circulating in the city of Diamantina (Minas Gerais, Brazil

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Costa MA

2018-05-01

Full Text Available Marina A Costa,1 Layane M Teodoro,1 Gustavo H Bahia-de-Oliveira,2 Ana Paula N Nunes,3 Ricardo A Barata1 1Laboratório de Parasitologia, Departamento de Ciências Biológicas, Universidade Federal dos Vales dos Jequitinhonha e Mucuri, Diamantina, MG, Brazil; 2Laboratório de Doenças Parasitárias, Departamento de Farmácia, Universidade Federal dos Vales dos Jequitinhonha e Mucuri, Diamantina, MG, Brazil; 3Laboratório de Bioestatística e Epidemiologia, Departamento de Ciências Básicas, Universidade Federal dos Vales dos Jequitinhonha e Mucuri, Diamantina, MG, Brazil Background: Banknotes are objects of great turnover and diffusion among the population, and can be efficient mechanisms in the dissemination of several intestinal parasites. This study investigated the presence of biological forms of intestinal parasites present in circulating cash banknotes in the city of Diamantina, Minas Gerais, Brazil, aiming to propose interventions aimed at improving local public health. Materials and methods: Between February and April 2017, samples of banknotes collected in five commercial establishments of the city were analyzed, namely: 1 gas station, 2 supermarket, 3 butchery, 4 pharmacy and 5 free fair. Ten circulating banknotes of each value (R$2.00, R$5.00, R$10.00, R$20.00, R$50.00 and R$100.00 were exchanged for new banknotes, washed with Tween 80 and, after spontaneous sedimentation, analyzed under an optical microscope with a magnification of 10× and 40×. Results: Cysts of Entamoeba coli (74.60%, cysts of Endolimax nana (16.94%, Giardia lamblia cysts (4.44%, unidentified nematode larvae (2.02%, Hymenolepis sp. (0.81%, Taenia sp. (0.81% and Ancylostomidae larvae (0.40% were found. Conclusions: The results revealed the need for improvements in basic sanitation, health and education activities that emphasized the importance of proper hand hygiene. Keywords: intestinal parasites, banknotes, Diamantina

Lysine acetylation in sexual stage malaria parasites is a target for antimalarial small molecules.

Science.gov (United States)

Trenholme, Katharine; Marek, Linda; Duffy, Sandra; Pradel, Gabriele; Fisher, Gillian; Hansen, Finn K; Skinner-Adams, Tina S; Butterworth, Alice; Ngwa, Che Julius; Moecking, Jonas; Goodman, Christopher D; McFadden, Geoffrey I; Sumanadasa, Subathdrage D M; Fairlie, David P; Avery, Vicky M; Kurz, Thomas; Andrews, Katherine T

2014-07-01

Therapies to prevent transmission of malaria parasites to the mosquito vector are a vital part of the global malaria elimination agenda. Primaquine is currently the only drug with such activity; however, its use is limited by side effects. The development of transmission-blocking strategies requires an understanding of sexual stage malaria parasite (gametocyte) biology and the identification of new drug leads. Lysine acetylation is an important posttranslational modification involved in regulating eukaryotic gene expression and other essential processes. Interfering with this process with histone deacetylase (HDAC) inhibitors is a validated strategy for cancer and other diseases, including asexual stage malaria parasites. Here we confirm the expression of at least one HDAC protein in Plasmodium falciparum gametocytes and show that histone and nonhistone protein acetylation occurs in this life cycle stage. The activity of the canonical HDAC inhibitors trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; Vorinostat) and a panel of novel HDAC inhibitors on early/late-stage gametocytes and on gamete formation was examined. Several compounds displayed early/late-stage gametocytocidal activity, with TSA being the most potent (50% inhibitory concentration, 70 to 90 nM). In contrast, no inhibitory activity was observed in P. falciparum gametocyte exflagellation experiments. Gametocytocidal HDAC inhibitors caused hyperacetylation of gametocyte histones, consistent with a mode of action targeting HDAC activity. Our data identify HDAC inhibitors as being among a limited number of compounds that target both asexual and sexual stage malaria parasites, making them a potential new starting point for gametocytocidal drug leads and valuable tools for dissecting gametocyte biology. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Adaptations in the energy metabolism of parasites

NARCIS (Netherlands)

van Grinsven, K.W.A.|info:eu-repo/dai/nl/304833436

2009-01-01

For this thesis fundamental research was performed on the metabolic adaptations found in parasites. Studying the adaptations in parasite metabolisms leads to a better understanding of parasite bioenergetics and can also result in the identification of new anti-parasitic drug targets. We focussed on

Sensitive Information Gathering and Dissemination: An Assessment ...

African Journals Online (AJOL)

Yet the freedom of expression granted to all men is not absolute. This paper on sensitive information gathering and dissemination focuses on the role of the military and that of the media in the gathering and dissemination of information often termed sensitive, contentious and inciting. It is based on past and present media ...

Efficacy of imidocarb dipropionate in eliminating Theileria equi from experimentally infected horses.

Science.gov (United States)

Grause, Juanita F; Ueti, Massaro W; Nelson, Jeffrey T; Knowles, Donald P; Kappmeyer, Lowell S; Bunn, Thomas O

2013-06-01

Theileria equi, one of the causative agents of equine piroplasmosis, is endemic in many regions of the world but is considered a 'foreign' animal disease in the USA. In an effort to prevent the importation of T. equi, stringent serological screening of horses is practiced prior to entry to the USA. Current regulatory options available where horses are found to be infected include permanent quarantine with or without chemotherapy, repatriation, or euthanasia. Chemotherapeutics that eliminate infection and subsequently transmission risk are critical in the management of infected horses. In this study, the efficacy of the drug imidocarb dipropionate against experimental T. equi infection was assessed. Of nine horses experimentally inoculated with T. equi isolated from an animal previously imported from Peru, six were treated with imidocarb dipropionate after the resolution of the acute phase of the disease. Elimination of the parasite was demonstrated in 5/6 by nested PCR, blood transfusions to naïve horses, and reversion to seronegative status. The findings support the use of this drug as a potential treatment option in controlling outbreaks of T. equi, and also suggest that 'combination testing' using both serological and PCR detection methods are necessary to demonstrate clearance of infection. Published by Elsevier Ltd.

Vaccine development against the Taenia solium parasite: the role of recombinant protein expression in Escherichia coli.

Science.gov (United States)

Gauci, Charles; Jayashi, César; Lightowlers, Marshall W

2013-01-01

Taenia solium is a zoonotic parasite that causes cysticercosis. The parasite is a major cause of human disease in impoverished communities where it is transmitted to humans from pigs which act as intermediate hosts. Vaccination of pigs to prevent transmission of T. solium to humans is an approach that has been investigated to control the disease. A recombinant vaccine antigen, TSOL18, has been remarkably successful at reducing infection of pigs with T. solium in several experimental challenge trials. The vaccine has been shown to eliminate transmission of naturally acquired T. solium in a field trial conducted in Africa. We recently reported that the vaccine was also effective in a field trial conducted in Peru. The TSOL18 recombinant antigen for each of these trials has been produced by expression in Escherichia coli. Here we discuss research that has been undertaken on the TSOL18 antigen and related antigens with a focus on improved methods of preparation of recombinant TSOL18 and optimized expression in Escherichia coli.

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

Universal leakage elimination

International Nuclear Information System (INIS)

Byrd, Mark S.; Lidar, Daniel A.; Wu, L.-A.; Zanardi, Paolo

2005-01-01

'Leakage' errors are particularly serious errors which couple states within a code subspace to states outside of that subspace, thus destroying the error protection benefit afforded by an encoded state. We generalize an earlier method for producing leakage elimination decoupling operations and examine the effects of the leakage eliminating operations on decoherence-free or noiseless subsystems which encode one logical, or protected qubit into three or four qubits. We find that by eliminating a large class of leakage errors, under some circumstances, we can create the conditions for a decoherence-free evolution. In other cases we identify a combined decoherence-free and quantum error correcting code which could eliminate errors in solid-state qubits with anisotropic exchange interaction Hamiltonians and enable universal quantum computing with only these interactions

Nutrition and metabolism of parasitized and non-parasitized ruminants. Some approaches for studying the mode of action of parasites

International Nuclear Information System (INIS)

Leng, R.A.

1981-01-01

The effects of helminth infections on ruminant digestive function and metabolism are discussed against the background of current information on the mechanisms controlling feed intake and utilization in normal animals. Although parasites reduce productivity by impairing appetite and utilization of nutrients, few studies have been conducted on the function of the digestive tract and the metabolism of parasitized animals. Those areas which warrant further investigation are described, and the techniques which could be usefully applied are outlined. It is concluded that more emphasis should be given to the diet available to parasitized animals, and that by using diets of different digestibility and protein content, valuable information could be obtained as to the relative importance of reduced appetite and reduced efficiency of feed utilization. Central to all studies is a proper delineation of the fate of proteins in the small intestine of parasitized animals, and characterization of the types of bacteria in the gut and their effects on endogenous protein losses. The application of 15 N is mentioned. The potential usefulness of 14 C (eg. to measure the flow of digesta, to the lower digestive tract; clearance of 14 C-propionate from blood; etc.) is described

Host Diet Affects the Morphology of Monarch Butterfly Parasites.

Science.gov (United States)

Hoang, Kevin; Tao, Leiling; Hunter, Mark D; de Roode, Jacobus C

2017-06-01

Understanding host-parasite interactions is essential for ecological research, wildlife conservation, and health management. While most studies focus on numerical traits of parasite groups, such as changes in parasite load, less focus is placed on the traits of individual parasites such as parasite size and shape (parasite morphology). Parasite morphology has significant effects on parasite fitness such as initial colonization of hosts, avoidance of host immune defenses, and the availability of resources for parasite replication. As such, understanding factors that affect parasite morphology is important in predicting the consequences of host-parasite interactions. Here, we studied how host diet affected the spore morphology of a protozoan parasite ( Ophryocystis elektroscirrha ), a specialist parasite of the monarch butterfly ( Danaus plexippus ). We found that different host plant species (milkweeds; Asclepias spp.) significantly affected parasite spore size. Previous studies have found that cardenolides, secondary chemicals in host plants of monarchs, can reduce parasite loads and increase the lifespan of infected butterflies. Adding to this benefit of high cardenolide milkweeds, we found that infected monarchs reared on milkweeds of higher cardenolide concentrations yielded smaller parasites, a potentially hidden characteristic of cardenolides that may have important implications for monarch-parasite interactions.

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

Spatio-temporal Use of Oral Rabies Vaccines in Fox Rabies Elimination Programmes in Europe.

Directory of Open Access Journals (Sweden)

Thomas F Müller

Full Text Available In Europe, the elimination of wildlife rabies using oral rabies vaccination [ORV] of foxes for more than 30 years has been a success story. Since a comprehensive review on the scope of the different oral rabies vaccine baits distributed across Europe has not been available yet, we evaluated the use of different vaccine baits over the entire period of ORV [1978-2014]. Our findings provide valuable insights into the complexity of ORV programs in terms of vaccine related issues. More than 10 oral vaccines against rabies were used over the past four decades. Depending on many factors, the extent to which oral rabies virus vaccines were used varied considerably resulting in huge differences in the number of vaccine doses disseminated in ORV campaigns as well as in large spatial and temporal overlaps. Although vaccine virus strains derived from the SAD rabies virus isolate were the most widely used, the success of ORV campaigns in Europe cannot be assigned to a single oral rabies virus vaccine alone. Rather, the successful elimination of fox rabies is the result of an interaction of different key components of ORV campaigns, i.e. vaccine strain, vaccine bait and strategy of distribution.

Spatio-temporal Use of Oral Rabies Vaccines in Fox Rabies Elimination Programmes in Europe

Science.gov (United States)

Müller, Thomas F.; Schröder, Ronald; Wysocki, Patrick; Mettenleiter, Thomas C.; Freuling, Conrad M.

2015-01-01

In Europe, the elimination of wildlife rabies using oral rabies vaccination [ORV] of foxes for more than 30 years has been a success story. Since a comprehensive review on the scope of the different oral rabies vaccine baits distributed across Europe has not been available yet, we evaluated the use of different vaccine baits over the entire period of ORV [1978–2014]. Our findings provide valuable insights into the complexity of ORV programs in terms of vaccine related issues. More than 10 oral vaccines against rabies were used over the past four decades. Depending on many factors, the extent to which oral rabies virus vaccines were used varied considerably resulting in huge differences in the number of vaccine doses disseminated in ORV campaigns as well as in large spatial and temporal overlaps. Although vaccine virus strains derived from the SAD rabies virus isolate were the most widely used, the success of ORV campaigns in Europe cannot be assigned to a single oral rabies virus vaccine alone. Rather, the successful elimination of fox rabies is the result of an interaction of different key components of ORV campaigns, i.e. vaccine strain, vaccine bait and strategy of distribution. PMID:26280895

Mechanisms of stage-transcending protection following immunization of mice with late liver stage-arresting genetically attenuated malaria parasites.

Directory of Open Access Journals (Sweden)

Brandon K Sack

2015-05-01

Full Text Available Malaria, caused by Plasmodium parasite infection, continues to be one of the leading causes of worldwide morbidity and mortality. Development of an effective vaccine has been encumbered by the complex life cycle of the parasite that has distinct pre-erythrocytic and erythrocytic stages of infection in the mammalian host. Historically, malaria vaccine development efforts have targeted each stage in isolation. An ideal vaccine, however, would target multiple life cycle stages with multiple arms of the immune system and be capable of eliminating initial infection in the liver, the subsequent blood stage infection, and would prevent further parasite transmission. We have previously shown that immunization of mice with Plasmodium yoelii genetically attenuated parasites (GAP that arrest late in liver stage development elicits stage-transcending protection against both a sporozoite challenge and a direct blood stage challenge. Here, we show that this immunization strategy engenders both T- and B-cell responses that are essential for stage-transcending protection, but the relative importance of each is determined by the host genetic background. Furthermore, potent anti-blood stage antibodies elicited after GAP immunization rely heavily on FC-mediated functions including complement fixation and FC receptor binding. These protective antibodies recognize the merozoite surface but do not appear to recognize the immunodominant merozoite surface protein-1. The antigen(s targeted by stage-transcending immunity are present in both the late liver stages and blood stage parasites. The data clearly show that GAP-engendered protective immune responses can target shared antigens of pre-erythrocytic and erythrocytic parasite life cycle stages. As such, this model constitutes a powerful tool to identify novel, protective and stage-transcending T and B cell targets for incorporation into a multi-stage subunit vaccine.

Parasites from the Past

DEFF Research Database (Denmark)

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

will investigate how the diversity of food-borne parasitic infections has changed with cultural and dietary habits, hunting practice and intensity of animal husbandry. This is done by isolating and typing ancient DNA remains from parasite eggs found in archeological samples from across Denmark....

48 CFR 1252.242-70 - Dissemination of information-educational institutions.

Science.gov (United States)

2010-10-01

... Provisions and Clauses 1252.242-70 Dissemination of information—educational institutions. As prescribed in (TAR) 48 CFR 1242.7000(a), insert the following clause: Dissemination of Information—Educational... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Dissemination of...

INTESTINAL AND BLOOD PARASITES OF MAN IN TIMOR

Directory of Open Access Journals (Sweden)

W. Patrick Carney

2012-09-01

Full Text Available Survey tinja dan darah dipulau Timor guna menentukan distribusi dan prevalensi penyakit parasit diantara penduduk telah dilakukan pada bulan Juli dan Agustus tahun 1972 sebagai kelanjutan dari deretan survey yang dilakukan oleh Direktorat Jenderal Pencegahan Pemberantasan Penyakit menular Departemen Kesehatan, Bagian Parasitologi dan Pathologi Umum Fakultas Kedokteran Universitas Indonesia dan US Namru-2 di Indonesia. Sejumlah 445 sediaan tinja untuk pemeriksaan parasit usus, 581 sediaan darah untuk pemeriksaan parasit malaria dan 663 sediaan darah untuk pemeriksaan parasit filaria telah diambil dari penduduk cara merata di 7 desa pada 3 kabupaten di Timor, Nusa Tenggara Timur. Enam puluh delapan per cent diantara penduduk melihatkan satu atau lebih parasit usus didalam tinjanya dimana cacing tambang merupakan parasit usus yang terbanyak. Ascaris lumbricoides ketemukan jauh lebih kurang daripada di Jawa, Sumatra dan Sulawesi, juga diketemukan perbedaan itara "intestinal parasite rate" di Timor Indonesia dan Timor Portugis. Dua belas percent penduduk yang diperiksa melihatkan parasit malaria didalam darahnya sedangkan parasit filaria ditemukan sebanyak 8 percent. Plasmodium falciparum merupakan parasit malaria yang terbanyak ditemukan, ia jenis parasit fdaria yang ditemukan adalah "Timor microfilaria" dan Wuchereria bancrofti dimana yang pertama merupakan parasit yang terbanyak diantara penduduk yang diperiksa.

The importance of serological tests implementation in disseminated candidiasis diagnose.

Science.gov (United States)

Gegić, Merima; Numanović, Fatima; Delibegović, Zineta; Tihić, Nijaz; Nurkić, Mahmut; Hukić, Mirsada

2013-03-01

Candidiasis is defined as an infection or disease caused by a fungus of the genus Candida. Rate of disseminated candidiasis increases with the growth of the number of immunocompromised patients. In the the last few decades the incidence of disseminated candidiasis is in growth as well as the mortality rate. The aim of this survey is to show the importance of serological tests implementation in disseminated candidiasis diagnose. This is a prospective study involving 60 patients with malign diseases with and without clinical signs of disseminated candidiasis and 30 healthy people who represent the control group. Apart from hemoculture, detection of circulating mannan antigen and adequate antibodies of Candida species applying comercial ELISA test was determined in each patient. This survey deals with relevant factors causing disseminated candidiasis. This survey showed that the group of patients with clinical signs of disseminated candidiasis had more patients with positive hemoculture to Candida species, then the group of patients without clinical signs of disseminated candidiasis. The number of patients being examined and positive to antigens and antibodies was higher (p candidiasis (7/30; 23.3%), then in the group of patients without clinical signs of disseminated candidiasis (0/30; 0%): Average value of titra antigen was statistically higher (p candidiasis 6/30 (20%) of patients had Candida spp.positive hemocultures while in the group of patients without clinical signs of disseminated candidiasis 1/30 (3.3%) of patients had Candida spp. positive hemocultures, which was considerably higher (p candidiasis were statistically significant, while correlation of results of hemoculture and antibodies was insignificant. Because of low sensitivity of hemoculture and time needed for isolation of Candida spp., introducing serological tests in regular procedures would speed disseminated candidiasis diagnose.

One Health: parasites and beyond…

OpenAIRE

Blake, DP; Betson, ME

2016-01-01

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 med...

Pervasiveness of parasites in pollinators.

Directory of Open Access Journals (Sweden)

Sophie E F Evison

Full Text Available Many pollinator populations are declining, with large economic and ecological implications. Parasites are known to be an important factor in the some of the population declines of honey bees and bumblebees, but little is known about the parasites afflicting most other pollinators, or the extent of interspecific transmission or vectoring of parasites. Here we carry out a preliminary screening of pollinators (honey bees, five species of bumblebee, three species of wasp, four species of hoverfly and three genera of other bees in the UK for parasites. We used molecular methods to screen for six honey bee viruses, Ascosphaera fungi, Microsporidia, and Wolbachia intracellular bacteria. We aimed simply to detect the presence of the parasites, encompassing vectoring as well as actual infections. Many pollinators of all types were positive for Ascosphaera fungi, while Microsporidia were rarer, being most frequently found in bumblebees. We also detected that most pollinators were positive for Wolbachia, most probably indicating infection with this intracellular symbiont, and raising the possibility that it may be an important factor in influencing host sex ratios or fitness in a diversity of pollinators. Importantly, we found that about a third of bumblebees (Bombus pascuorum and Bombus terrestris and a third of wasps (Vespula vulgaris, as well as all honey bees, were positive for deformed wing virus, but that this virus was not present in other pollinators. Deformed wing virus therefore does not appear to be a general parasite of pollinators, but does interact significantly with at least three species of bumblebee and wasp. Further work is needed to establish the identity of some of the parasites, their spatiotemporal variation, and whether they are infecting the various pollinator species or being vectored. However, these results provide a first insight into the diversity, and potential exchange, of parasites in pollinator communities.

Delay-Aware Program Codes Dissemination Scheme in Internet of Everything

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Yixuan Xu

2016-01-01

Full Text Available Due to recent advancements in big data, connection technologies, and smart devices, our environment is transforming into an “Internet of Everything” (IoE environment. These smart devices can obtain new or special functions by reprogramming: upgrade their soft systems through receiving new version of program codes. However, bulk codes dissemination suffers from large delay, energy consumption, and number of retransmissions because of the unreliability of wireless links. In this paper, a delay-aware program dissemination (DAPD scheme is proposed to disseminate program codes with fast, reliable, and energy-efficient style. We observe that although total energy is limited in wireless sensor network, there exists residual energy in nodes deployed far from the base station. Therefore, DAPD scheme improves the performance of bulk codes dissemination through the following two aspects. (1 Due to the fact that a high transmitting power can significantly improve the quality of wireless links, transmitting power of sensors with more residual energy is enhanced to improve link quality. (2 Due to the fact that performance of correlated dissemination tends to degrade in a highly dynamic environment, link correlation is autonomously updated in DAPD during codes dissemination to maintain improvements brought by correlated dissemination. Theoretical analysis and experimental results show that, compared with previous work, DAPD scheme improves the dissemination performance in terms of completion time, transmission cost, and the efficiency of energy utilization.

Malaria programme personnel's experiences, perceived barriers and facilitators to implementing malaria elimination strategy in South Africa.

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Hlongwana, Khumbulani Welcome; Sartorius, Benn; Tsoka-Gwegweni, Joyce

2018-01-10

South Africa has set an ambitious goal targeting to eliminate malaria by 2018, which is consistent with the United Nations Sustainable Development Goals' call to end the epidemic of malaria by 2030 across the globe. There are conflicting views regarding the feasibility of malaria elimination, and furthermore studies investigating malaria programme personnel's perspectives on strategy implementation are lacking. The study was a cross-sectional survey conducted in 2014 through a face-to-face investigator-administered semi-structured questionnaire to all eligible and consenting malaria programme personnel (team leader to senior manager levels) in three malaria endemic provinces (KwaZulu-Natal, Mpumalanga, and Limpopo) of South Africa. The overall response rate was 88.6% (148/167) among all eligible malaria personnel. The mean age of participants was 47 years (SD 9.7, range 27-70), and the mean work experience of 19.4 years (SD 11.1, range 0-42). The majority were male (78.4%), and 66.9% had secondary level education. Awareness of the malaria elimination policy was high (99.3%), but 89% contended that they were never consulted when the policy was formulated and few had either seen (29.9%) or read (23%) the policy, either in full or in part. Having read the policy was positively associated with professional job designations (managers, EHPs and entomologists) (p = 0.010) and tertiary level education (p = 0.042). There was a sentiment that the policy was neither sufficiently disseminated to all key healthcare workers (76.4%) nor properly adapted (68.9%) for the local operational context in the elimination strategy. Most (89.1%) participants were not optimistic about eliminating malaria by 2018, as they viewed the elimination strategy in South Africa as too theoretical with unrealistic targets. Other identified barriers included inadequate resources (53.5%) and high cross-border movements (19.8%). Most participants were not positive that South Africa could achieve

Disseminated cryptococcosis in an immunocompetent patient.

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Mada, Pradeep; Nowack, Brad; Cady, Beth; Joel Chandranesan, Andrew Stevenson

2017-07-18

Cryptococcosis is a fungal infection which is commonly associated with immune-compromised state. Disseminated infection in immunocompetent individuals is extremely rare. We present a case of a 56-year-old African American patient who presented with unilateral knee pain and swelling and was subsequently diagnosed with cryptococcal bone mass with dissemination of infection. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Disseminated intravascular coagulation (DIC)

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... Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 141. Thachil J, Toh CH. Current concepts in the management of disseminated intravascular coagulation. Thromb Res . 2012;129 ...

Genetics of simple and complex host-parasite interactions

International Nuclear Information System (INIS)

Sidhu, G.S.; Webster, J.M.

1977-01-01

In nature a host plant can be viewed as a miniature replica of an ecological system where true and incidental parasites share the same habitat. Consequently, they influence each other's presence directly by interspecific interaction, and indirectly by inducing changes in the host's physiology and so form disease complexes. Since all physiological phenomena have their counterpart in the respective genetic systems of interacting organisms, valuable genetic information can be derived from the analysis of complex parasitic systems. Disease complexes may be classified according to the nature of interaction between various parasites on the same host. One parasite may nullify the host's resistance to another (e.g. Tomato - Meloidogyne incognita + Fusarium oxysporum lycopersici system). Conversely, a parasite may invoke resistance in the host against another parasite (e.g. Tomato - Fusarium oxysporum lycopersici + Verticillium albo atrum system). From the study of simple parasitic systems we know that resistance versus susceptibility against a single parasite is normally monogenically controlled. However, when more than one parasite interacts to invoke or nullify each other's responses on the same host plant, the genetic results suggest epistatic ratios. Nevertheless, epistatic ratios have been obtained also from simple parasitic systems owing to gene interaction. The epistatic ratios obtained from complex and simple parasitic systems are contrasted and compared. It is suggested that epistatic ratios obtained from simple parasitic systems may, in fact, be artifacts resulting from complex parasitic associations that often occur in nature. Polygenic inheritance and the longevity of a cultivar is also discussed briefly in relation to complex parasitic associations. Induced mutations can play a significant role in the study of complex parasitic associations, and thus can be very useful in controlling plant diseases

Egg size matching by an intraspecific brood parasite

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Lemons, Patrick R.; Sedinger, James S.

2011-01-01

Avian brood parasitism provides an ideal system with which to understand animal recognition and its affect on fitness. This phenomenon of laying eggs in the nests of other individuals has classically been framed from the perspective of interspecific brood parasitism and host recognition of parasitic eggs. Few examples exist of strategies adopted by intraspecific brood parasites to maximize success of parasitic eggs. Intraspecific brood parasitism within precocial birds can be a risky strategy in that hatch synchrony is essential to reproductive success. Given that egg size is positively correlated with incubation time, parasitic birds would benefit by recognizing and selecting hosts with a similar egg size. Intraspecific brood parasitism is an alternative reproductive strategy in black brant (Branta bernicla nigricans), a colonial nesting goose with precocial young. Based on a randomization test, parasitic eggs in this study differed less in size from eggs in their host's nests than did random eggs placed in random nests. Parasitic eggs were remarkably similar in size to hosts’ eggs, differing by nests differed by nearly 8%. The precision with which parasitic brant match the egg size of hosts in our study supports our hypothesis that brant match egg size of hosts, thereby maximizing hatching success of their parasitic eggs.

Information Dissemination: Case Studies on Electronic Dissemination at Four Agencies.

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1992-07-01

Departments of Health and Human Services, Agriculture , and Commerce; and the Chairmen, House Committee on Government Operations and Senate and House...AVLINE Audio Visuals On-line BIOETHICSLINE Bioethics On-line Page 5 GAOIIMTEC-92-6FS Electronic Information Dissemination Contents CANCERLIT Cancer...Network TOXLINE Toxicology Information On-line TOXLIT Toxicology Literature from special sources USDA U.S. Department of Agriculture Page 6 GAOIIMTEC-92

Tracking Users for a Targeted Dissemination

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Philippe Bautier

2015-12-01

Full Text Available How to build a dissemination and communication strategy in a world where users have easy access to a deluge of data and information from various origins and where IT tools and design standards change so quickly that users behaviour and their expectations are continuously modified? The first challenge of Eurostat is clearly to know what users want: we know our different types of users but we have to identify how they get our data, what they do with our data, how they react to our outputs and which sort of new service they would like us to propose. Translating these needs into a visual dissemination is a new challenge undertaken by Eurostat through a new portal, new mobile apps and new info graphs and basic application as well as increasing the visibility on Google. The objective of this paper is to share Eurostat's experience in identifying user Leeds and to show how concretely this information has been visually disseminated.

Subversion of complement by hematophagous parasites.

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Schroeder, Hélène; Skelly, Patrick J; Zipfel, Peter F; Losson, Bertrand; Vanderplasschen, Alain

2009-01-01

The complement system is a crucial part of innate and adaptive immunity which exerts a significant evolutionary pressure on pathogens. It has selected for those pathogens, mainly microorganisms but also parasites, that have evolved countermeasures. The characterization of how pathogens evade complement attack is a rapidly developing field of current research. In recent years, multiple complement evasion strategies have been characterized. In this review, we focus on complement escape mechanisms expressed by hematophagous parasites, a heterogeneous group of metazoan parasites that share the property of ingesting the whole blood of their host. Complement inhibition is crucial for parasite survival within the host tissue or to facilitate blood feeding. Finally, complement inhibition by hematophagous parasites may also contribute to their success as pathogen vectors.

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.

De novo assembly and characterization of the transcriptome of the parasitic weed dodder identifies genes associated with plant parasitism.

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Ranjan, Aashish; Ichihashi, Yasunori; Farhi, Moran; Zumstein, Kristina; Townsley, Brad; David-Schwartz, Rakefet; Sinha, Neelima R

2014-11-01

Parasitic flowering plants are one of the most destructive agricultural pests and have major impact on crop yields throughout the world. Being dependent on finding a host plant for growth, parasitic plants penetrate their host using specialized organs called haustoria. Haustoria establish vascular connections with the host, which enable the parasite to steal nutrients and water. The underlying molecular and developmental basis of parasitism by plants is largely unknown. In order to investigate the process of parasitism, RNAs from different stages (i.e. seed, seedling, vegetative strand, prehaustoria, haustoria, and flower) were used to de novo assemble and annotate the transcriptome of the obligate plant stem parasite dodder (Cuscuta pentagona). The assembled transcriptome was used to dissect transcriptional dynamics during dodder development and parasitism and identified key gene categories involved in the process of plant parasitism. Host plant infection is accompanied by increased expression of parasite genes underlying transport and transporter categories, response to stress and stimuli, as well as genes encoding enzymes involved in cell wall modifications. By contrast, expression of photosynthetic genes is decreased in the dodder infective stages compared with normal stem. In addition, genes relating to biosynthesis, transport, and response of phytohormones, such as auxin, gibberellins, and strigolactone, were differentially expressed in the dodder infective stages compared with stems and seedlings. This analysis sheds light on the transcriptional changes that accompany plant parasitism and will aid in identifying potential gene targets for use in controlling the infestation of crops by parasitic weeds. © 2014 American Society of Plant Biologists. All Rights Reserved.

The adaptive significance of inquiline parasite workers

DEFF Research Database (Denmark)

Sumner, Seirian; Nash, David R; Boomsma, Jacobus J

2003-01-01

Social parasites exploit the socially managed resources of their host's society. Inquiline social parasites are dependent on their host throughout their life cycle, and so many of the traits inherited from their free-living ancestor are removed by natural selection. One trait that is commonly lost...... is the worker caste, the functions of which are adequately fulfilled by host workers. The few inquiline parasites that have retained a worker caste are thought to be at a transitional stage in the evolution of social parasitism, and their worker castes are considered vestigial and non-adaptive. However...... a vital role in ensuring the parasite's fitness. We show that the presence of these parasite workers has a positive effect on the production of parasite sexuals and a negative effect on the production of host sexuals. This suggests that inquiline workers play a vital role in suppressing host queen...

Rare species of fungi parasiting on algae I. Parasites of Spirogyra and Mougeotia

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Joanna Z. Kadłubowska

2014-08-01

Full Text Available Investigations carried out on the genus Spirogyra Link and Mougeotia Agardh revealed the following species of fungi parasiting in the Spirogyra and Mougeotia cells: Olpidium endogenum, Blyttiomyces helicus, B. spinulosus, Micromyces zygogonii and Rhizophydium ampullaceum. First information on B. helicus as parasitic on algae is presented.

Population genetics analysis during the elimination process of Plasmodium falciparum in Djibouti.

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Khaireh, Bouh Abdi; Assefa, Ashenafi; Guessod, Hawa Hassan; Basco, Leonardo K; Khaireh, Mohamed Abdi; Pascual, Aurélie; Briolant, Sébastien; Bouh, Samatar Mohamed; Farah, Ismaïl Hassan; Ali, Habib Moussa; Abdi, Abdoul-Ilah Ahmed; Aden, Mouna Osman; Abdillahi, Zamzam; Ayeh, Souleiman Nour; Darar, Houssein Youssouf; Koeck, Jean-Louis; Rogier, Christophe; Pradines, Bruno; Bogreau, Hervé

2013-06-13

Case management of imported malaria within the context of malaria pre-elimination is increasingly considered to be relevant because of the risk of resurgence. The assessment of malaria importation would provide key data i) to select countries with propitious conditions for pre-elimination phase and ii) to predict its feasibility. Recently, a sero-prevalence study in Djibouti indicated low malaria prevalence, which is propitious for the implementation of pre-elimination, but data on the extent of malaria importation remain unknown. Djiboutian plasmodial populations were analysed over an eleven-year period (1998, 1999, 2002 and 2009). The risk of malaria importation was indirectly assessed by using plasmodial population parameters. Based on 5 microsatellite markers, expected heterozygosity (H.e.), multiplicity of infection, pairwise Fst index, multiple correspondence analysis and individual genetic relationship were determined. The prevalence of single nucleotide polymorphisms associated with pyrimethamine resistance was also determined. Data indicated a significant decline in genetic diversity (0.51, 0.59, 0.51 and 0 in 1998, 1999, 2002 and 2009, respectively) over the study period, which is inconsistent with the level of malaria importation described in a previous study. This suggested that Djiboutian malaria situation may have benefited from the decline of malaria prevalence that occurred in neighbouring countries, in particular in Ethiopia. The high Fst indices derived from plasmodial populations from one study period to another (0.12 between 1999 and 2002, and 0.43 between 2002 and 2009) suggested a random sampling of parasites, probably imported from neighbouring countries, leading to oligo-clonal expansion of few different strains during each transmission season. Nevertheless, similar genotypes observed during the study period suggested recurrent migrations and imported malaria. In the present study, the extent of genetic diversity was used to assess the risk

cAMP-Signalling Regulates Gametocyte-Infected Erythrocyte Deformability Required for Malaria Parasite Transmission.

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Ghania Ramdani

2015-05-01

Full Text Available Blocking Plasmodium falciparum transmission to mosquitoes has been designated a strategic objective in the global agenda of malaria elimination. Transmission is ensured by gametocyte-infected erythrocytes (GIE that sequester in the bone marrow and at maturation are released into peripheral blood from where they are taken up during a mosquito blood meal. Release into the blood circulation is accompanied by an increase in GIE deformability that allows them to pass through the spleen. Here, we used a microsphere matrix to mimic splenic filtration and investigated the role of cAMP-signalling in regulating GIE deformability. We demonstrated that mature GIE deformability is dependent on reduced cAMP-signalling and on increased phosphodiesterase expression in stage V gametocytes, and that parasite cAMP-dependent kinase activity contributes to the stiffness of immature gametocytes. Importantly, pharmacological agents that raise cAMP levels in transmissible stage V gametocytes render them less deformable and hence less likely to circulate through the spleen. Therefore, phosphodiesterase inhibitors that raise cAMP levels in P. falciparum infected erythrocytes, such as sildenafil, represent new candidate drugs to block transmission of malaria parasites.

Glyoxalase diversity in parasitic protists.

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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.

Social-Driven Information Dissemination for Mobile Wireless Sensor Networks

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Basim MAHMOOD

2015-06-01

Full Text Available As we move into the so-called Internet of Things (IoT, the boundary between sensor networks and social networks is likely to disappear. Moreover, previous works argue that mobility in sensor networks may become a consequence of human movement making the understanding of human mobility crucial to the design of sensor networks. When people carry sensors, they become able to use concepts from social networks in the design of sensor network infrastructures. However, to this date, the utilization of social networks in designing protocols for wireless sensor networks has not received much attention. In this paper, we focus on the concept of information dissemination in a framework where sensors are carried by people who, like most of us, are part of a social network. We propose two social-based forwarding approaches for what has been called Social Network of Sensors (SNoS. To this end, we exploit two important characteristics of ties in social networks, namely strong ties and weak ties. The former is used to achieve rapid dissemination to nearby sensors while the latter aims at dissemination to faraway sensors. We compared our results against two well-known approaches in the literature: Epidemic and PRoPHET protocols. We evaluate our approaches according to four criteria: information-dissemination distance, information-dissemination coverage area, the number of messages exchanged, and information delivery time. We believe this is the first work that investigates the issues of information-dissemination distance and information-dissemination coverage area using an approach inspired on social network concepts.

Information dissemination and use: critical components in occupational safety and health.

Science.gov (United States)

Schulte, P A; Okun, A; Stephenson, C M; Colligan, M; Ahlers, H; Gjessing, C; Loos, G; Niemeier, R W; Sweeney, M H

2003-11-01

Information dissemination is a mandated, but understudied, requirement of occupational and environmental health laws and voluntary initiatives. Research is needed on the factors that enhance and limit the development, transfer, and use of occupational safety and health information (OSH). Contemporary changes in the workforce, workplaces, and the nature of work will require new emphasis on the dissemination of information to foster prevention. Legislative and regulatory requirements and voluntary initiatives for dissemination of OSH information were identified and assessed. Literature on information dissemination was reviewed to identify important issues and useful approaches. More than 20 sections of laws and regulations were identified that mandated dissemination of occupational and environmental safety and health information. A four-stage approach for tracking dissemination and considering the flow of information was delineated. Special areas of dissemination were identified: the information needs of the changing workforce, new and young workers; small businesses; and workers with difficulty in understanding or reading English. We offer a framework for dissemination of OSH information and underscore the need to focus on the extent to which decision-makers and others receive and use such information. More solid data are also needed on current investments in disseminating, diffusing and applying OSH information and on the utility of that information. Am. J. Ind. Med. 44:515-531, 2003. Published 2003 Wiley-Liss, Inc.

An investigation of parasitic infections and review of molecular characterization of the intestinal protozoa in nonhuman primates in China from 2009 to 2015.

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Li, Junqiang; Dong, Haiju; Wang, Rongjun; Yu, Fuchang; Wu, Yayun; Chang, Yankai; Wang, Chenrong; Qi, Meng; Zhang, Longxian

2017-04-01

Parasites are a well-known threat to nonhuman primate (NHP) populations, and potentially cause zoonotic diseases in humans. In this study, the basic data was provided of the parasites in NHPs and the molecular characterization of the Enterocytozoon bieneusi , Giardia duodenalis , Cryptosporidium spp., and Entamoeba spp. were reviewed, which were found in these samples. A total of 3349 fecal samples were collected from 34 species reared at 17 districts in zoos, farms, free-range, or research laboratories, and examined microscopically. Eleven genera of intestinal parasites were detected: five genera of protozoans ( Isospora spp., Entamoeba spp., Giardia sp., Cryptosporidium spp., and Cyclospora spp.) and six genera of helminths ( Trichuris spp., Strongyloides spp., Ascaris spp., Physaloptera spp., Ancylostoma spp., and Enterobius spp.). The overall sample prevalence of parasitic infection was 54.1% (1811/3349). Entamoeba spp. was the most prevalent (36.4%, 1218/3349). The infection rate was the highest in free-range animals (73.0%, 670/918) (P Entamoeba spp., Trichuris spp., and Strongyloides spp.. Molecular characterization was reviewed of Enterocytozoon bieneusi , Giardia duodenalis , Cryptosporidium spp., and Entamoeba spp., as these are zoonotic species or genotypes. This parasitological data for NHPs in China, provides important information for veterinarians and public health authorities for the elimination of such parasites and monitor the potential transmission of zoonotic infections from NHPs.

Cacades: A reliable dissemination protocol for data collection sensor network

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Peng, Y.; Song, W.; Huang, R.; Xu, M.; Shirazi, B.; LaHusen, R.; Pei, G.

2009-01-01

In this paper, we propose a fast and reliable data dissemination protocol Cascades to disseminate data from the sink(base station) to all or a subset of nodes in a data collection sensor network. Cascades makes use of the parentmonitor-children analogy to ensure reliable dissemination. Each node monitors whether or not its children have received the broadcast messages through snooping children's rebroadcasts or waiting for explicit ACKs. If a node detects a gap in its message sequences, it can fetch the missing messages from its neighbours reactively. Cascades also considers many practical issues for field deployment, such as dynamic topology, link/node failure, etc.. It therefore guarantees that a disseminated message from the sink will reach all intended receivers and the dissemination is terminated in a short time period. Notice that, all existing dissemination protocols either do not guarantee reliability or do not terminate [1, 2], which does not meet the requirement of real-time command control. We conducted experiment evaluations in both TOSSIM simulator and a sensor network testbed to compare Cascades with those existing dissemination protocols in TinyOS sensor networks, which show that Cascades achieves a higher degree of reliability, lower communication cost, and less delivery delay. ??2009 IEEE.

Trypanosomatid Infections: How Do Parasites and Their Excreted–Secreted Factors Modulate the Inducible Metabolism of l-Arginine in Macrophages?

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Philippe Holzmuller

2018-04-01

Full Text Available Mononuclear phagocytes (monocytes, dendritic cells, and macrophages are among the first host cells to face intra- and extracellular protozoan parasites such as trypanosomatids, and significant expansion of macrophages has been observed in infected hosts. They play essential roles in the outcome of infections caused by trypanosomatids, as they can not only exert a powerful antimicrobial activity but also promote parasite proliferation. These varied functions, linked to their phenotypic and metabolic plasticity, are exerted via distinct activation states, in which l-arginine metabolism plays a pivotal role. Depending on the environmental factors and immune response elements, l-arginine metabolites contribute to parasite elimination, mainly through nitric oxide (NO synthesis, or to parasite proliferation, through l-ornithine and polyamine production. To survive and adapt to their hosts, parasites such as trypanosomatids developed mechanisms of interaction to modulate macrophage activation in their favor, by manipulating several cellular metabolic pathways. Recent reports emphasize that some excreted–secreted (ES molecules from parasites and sugar-binding host receptors play a major role in this dialog, particularly in the modulation of the macrophage’s inducible l-arginine metabolism. Preventing l-arginine dysregulation by drugs or by immunization against trypanosomatid ES molecules or by blocking partner host molecules may control early infection and is a promising way to tackle neglected diseases including Chagas disease, leishmaniases, and African trypanosomiases. The present review summarizes recent knowledge on trypanosomatids and their ES factors with regard to their influence on macrophage activation pathways, mainly the NO synthase/arginase balance. The review ends with prospects for the use of biological knowledge to develop new strategies of interference in the infectious processes used by trypanosomatids, in particular for the

Brood parasitism and quasi-parasitism in the European barn swallow Hirundo rustica rustica

Czech Academy of Sciences Publication Activity Database

Petrželková, Adéla; Michálková, R.; Albrechtová, Jana; Cepák, J.; Honza, Marcel; Kreisinger, J.; Munclinger, P.; Soudková, M.; Tomášek, Oldřich; Albrecht, Tomáš

2015-01-01

Roč. 69, č. 9 (2015), s. 1405-1414 ISSN 0340-5443 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : Altricial birds * Colonial breeding * Conspecific brood parasitism * Egg dumping * Host fitness * Parasite fitness Subject RIV: EG - Zoology Impact factor: 2.382, year: 2015

Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

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Silvestre A.

2004-06-01

Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

From Parasite Encounter to Infection: Multiple-Scale Drivers of Parasite Richness in a Wild Social Primate Population

Science.gov (United States)

Benavides J. A.; Huchard, E.; Pettorelli, N.; King, A. J.; Brown, M. E.; Archer, C. E.; Appleton, C. C.; Raymond, M.; Cowlishaw, G.

2011-01-01

Host parasite diversity plays a fundamental role in ecological and evolutionary processes, yet the factors that drive it are still poorly understood. A variety of processes, operating across a range of spatial scales, are likely to influence both the probability of parasite encounter and subsequent infection. Here, we explored eight possible determinants of parasite richness, comprising rainfall and temperature at the population level, ranging behavior and home range productivity at the group level, and age, sex, body condition, and social rank at the individual level. We used a unique dataset describing gastrointestinal parasites in a terrestrial subtropical vertebrate (chacma baboons, Papio ursinus), comprising 662 faecal samples from 86 individuals representing all age-sex classes across two groups over two dry seasons in a desert population. Three mixed models were used to identify the most important factor at each of the three spatial scales (population, group, individual); these were then standardised and combined in a single, global, mixed model. Individual age had the strongest influence on parasite richness, in a convex relationship. Parasite richness was also higher in females and animals in poor condition, albeit at a lower order of magnitude than age. Finally, with a further halving of effect size, parasite richness was positively correlated to day range and temperature. These findings indicate that a range of factors influence host parasite richness through both encounter and infection probabilities, but that individual-level processes may be more important than those at the group or population level.

Microaspiration of esophageal gland cells and cDNA library construction for identifying parasitism genes of plant-parasitic nematodes.

Science.gov (United States)

Hussey, Richard S; Huang, Guozhong; Allen, Rex

2011-01-01

Identifying parasitism genes encoding proteins secreted from a plant-parasitic nematode's esophageal gland cells and injected through its stylet into plant tissue is the key to understanding the molecular basis of nematode parasitism of plants. Parasitism genes have been cloned by directly microaspirating the cytoplasm from the esophageal gland cells of different parasitic stages of cyst or root-knot nematodes to provide mRNA to create a gland cell-specific cDNA library by long-distance reverse-transcriptase polymerase chain reaction. cDNA clones are sequenced and deduced protein sequences with a signal peptide for secretion are identified for high-throughput in situ hybridization to confirm gland-specific expression.

48 CFR 1205.101 - Methods of disseminating information.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Methods of disseminating information. 1205.101 Section 1205.101 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION... disseminating information. (b) The DOT Office of Small and Disadvantaged Business Utilization (S-40), 400 7th...

Parasites of mammals species abundance near zone Chernobyl

International Nuclear Information System (INIS)

Pen'kevich, V.A.

2014-01-01

In wildlife reserve parasitize various types of parasites: arachnids (mites) parasitic insects (horseflies, keds, mosquitoes, gnats, midges), helminths (trematodes, cestodes, nematodes and acanthocephalans) and parasitic protozoa. In quantity: 3 (beaver) to 25 species (wolf). (authors)

Parasites in Forensic Science: a historic perspective

Science.gov (United States)

Cardoso, Rita; Alves, Helena; Richter, Joachim; Botelho, Monica C

Parasites show a great potential to Forensic Science. Forensic Science is the application of any science and methodology to the legal system. The forensic scientist collects and analyses the physical evidence and produce a report of the results to the court. A parasite is an organism that lives at the expense of another and they exist in any ecosystem. Parasites are the cause of many important diseases. The forensic scientists can use the parasites to identify a crime scene, to determine the murder weapon or simply identify an individual. The applications for parasites in the Forensic Science can be many and more studies should be made in Forensic Parasitology. The most important parasites in Forensic Science are helminths specifically schistosomes. Through history there are many cases where schistosomes were described in autopsies and it was related to the cause of death. Here we review the applications of parasites in Forensic Science and its importance to the forensic scientist.

Meso- and bathy-pelagic fish parasites at the Mid-Atlantic Ridge (MAR): Low host specificity and restricted parasite diversity

Science.gov (United States)

Klimpel, Sven; Busch, Markus Wilhelm; Sutton, Tracey; Palm, Harry Wilhelm

2010-04-01

Seven meso- and bathy-pelagic fish species from the Mid-Atlantic Ridge (MAR) were firstly studied for fish parasites and feeding ecology. With a total of seven parasite species, the 247 meso- and bathy-pelagic deep-sea fish specimens belonging to the families Melamphaidae (3 spp.), Myctophidae (3 spp.) and Stomiidae (1 sp.) revealed low parasite diversity. The genetically identified nematodes Anisakis simplex (s.s.) and Anisakis pegreffii from the body cavity, liver and muscles of Myctophum punctatum were the most abundant parasites, reaching a prevalence of 91.4% and mean intensity of 3.1 (1-14). Anisakis sp. (unidentified) infected Chauliodus sloani and Poromitra crassiceps. Bothriocephalidean and tetraphyllidean cestode larvae infected Benthosema glaciale, the latter also occurring in C. sloani and Scopelogadus beanii, at low prevalences. Adult parasites at low infection rates included the digenean Lethadena sp. (2.9%), and the two copepod species Sarcotretes scopeli (5.7%) and Tautochondria dolichoura (5.3-11.4%). The myctophid Lampanyctus macdonaldi and the melamphaid Scopelogadus mizolepis mizolepis were free of parasites. Analyses of the stomach contents revealed crustaceans, especially copepods and euphausiids for the myctophids and also amphipods for the melamphaids as predominant prey items. While all stomachs showing distinct content comprising often unidentified 'tissue' (possibly gelatinous zooplankton), only C. sloani preyed upon fish. Though this feeding habit would enable transfer of a variety of crustacean-transmitted parasites into the fish, the parasite fauna in the meso- and bathy-pelagic fish was species poor. All observed parasites showed low host specificity, demonstrating no distinct pattern of host-parasite co-evolution. The MAR is no barrier for the parasite distribution in the North Atlantic meso- and bathy-pelagial.

Canine faecal contamination and parasitic risk in the city of Naples (southern Italy

Directory of Open Access Journals (Sweden)

Veneziano Vincenzo

2006-09-01

Full Text Available Abstract Background Dogs are associated with more than 60 zoonotic diseases among which, parasitosis and, in particular, helminthosis, can pose serious public-health concerns worldwide. Many canine gastrointestinal parasites eliminate their dispersion elements (eggs, larvae, oocysts by the faecal route. The quantity of canine faeces deposited on public and private property in cities worldwide is both a perennial nuisance and an important health issue. Public sites such as playgrounds, parks, gardens, public squares and sandpits may be an important source of human infection. The aim of this study was to evaluate the extent of both canine faecal contamination in the city of Naples (southern Italy, and presence of canine parasitic elements, with particular regard to those which are potential agents of zoonosis. A regular grid of sub-areas (1 km × 700 m was overlaid on the city map using a Geographical Information System (GIS. In each sub-area the straightest 1 km transect was drawn and digitalized on-screen in the GIS. Between February and May 2005 canine faeces were counted along the 1 km transects in 143 sub-areas, and 415 canine faecal samples were collected and submitted to coprological examinations. Negative binomial regression models and Gaussian random effects models were used to analyze the association between faeces count and human population density taking into account for extraPoisson variability. Logistic regression model was used to evaluate the association between positivity to parasitic elements and number of canine faeces. Results Out of the 143 studied sub-areas, 141 (98.6% contained canine faeces. There was a strong spatial gradient with 48% of the total variability accounted by between neighbourhood variability; a positive association between the number of faeces and the human population density was found. Seventy (over 415, 16.9% canine faecal samples were positive for parasitic elements. There was no association between

DISSEMINATED HISTOPLASMOSIS DIAGNOSED ON BONE ...

African Journals Online (AJOL)

2009-12-02

Dec 2, 2009 ... Histoplasmosis, caused by two varieties of dimorphic fungi, Histoplasma ... from asymptomatic primary infection to disseminated disease in immunocompromised .... Addison's disease) tongue, gingivae, buccal mucosa,.

Use of Malachite Green-Loop Mediated Isothermal Amplification for Detection of Plasmodium spp. Parasites

Science.gov (United States)

Lucchi, Naomi W.; Ljolje, Dragan; Silva-Flannery, Luciana; Udhayakumar, Venkatachalam

2016-01-01

Malaria elimination efforts are hampered by the lack of sensitive tools to detect infections with low-level parasitemia, usually below the threshold of standard diagnostic methods, microscopy and rapid diagnostic tests. Isothermal nucleic acid amplification assays such as the loop-mediated isothermal amplification (LAMP), are well suited for field use as they do not require thermal cyclers to run the test. However, the use of specialized equipment, as described by many groups, reduces the versatility of the LAMP technique as a simple tool for use in endemic countries. In this study, the use of the malachite green (MG) dye, as a visual endpoint readout, together with a simple mini heat block was evaluated for the detection of malaria parasites. The assay was performed for 1 hour at 63°C and the results scored by 3 independent human readers. The limit of detection of the assay was determined using well-quantified Plasmodium spp. infected reference samples and its utility in testing clinical samples was determined using 190 pre-treatment specimens submitted for reference diagnosis of imported malaria in the United States. Use of a simplified boil and spin methods of DNA extraction from whole blood and filter paper was also investigated. We demonstrate the accurate and sensitive detection of malaria parasites using this assay with a detection limit ranging between 1–8 parasites/μL, supporting its applicability for the detection of infections with low parasite burden. This assay is compatible with the use of a simple boil and spin sample preparation method from both whole blood and filter papers without a loss of sensitivity. The MG-LAMP assay described here has great potential to extend the reach of molecular tools to settings where they are needed. PMID:26967908

Use of Malachite Green-Loop Mediated Isothermal Amplification for Detection of Plasmodium spp. Parasites.

Directory of Open Access Journals (Sweden)

Naomi W Lucchi

Full Text Available Malaria elimination efforts are hampered by the lack of sensitive tools to detect infections with low-level parasitemia, usually below the threshold of standard diagnostic methods, microscopy and rapid diagnostic tests. Isothermal nucleic acid amplification assays such as the loop-mediated isothermal amplification (LAMP, are well suited for field use as they do not require thermal cyclers to run the test. However, the use of specialized equipment, as described by many groups, reduces the versatility of the LAMP technique as a simple tool for use in endemic countries. In this study, the use of the malachite green (MG dye, as a visual endpoint readout, together with a simple mini heat block was evaluated for the detection of malaria parasites. The assay was performed for 1 hour at 63°C and the results scored by 3 independent human readers. The limit of detection of the assay was determined using well-quantified Plasmodium spp. infected reference samples and its utility in testing clinical samples was determined using 190 pre-treatment specimens submitted for reference diagnosis of imported malaria in the United States. Use of a simplified boil and spin methods of DNA extraction from whole blood and filter paper was also investigated. We demonstrate the accurate and sensitive detection of malaria parasites using this assay with a detection limit ranging between 1-8 parasites/μL, supporting its applicability for the detection of infections with low parasite burden. This assay is compatible with the use of a simple boil and spin sample preparation method from both whole blood and filter papers without a loss of sensitivity. The MG-LAMP assay described here has great potential to extend the reach of molecular tools to settings where they are needed.

Rare species of fungi parasiting on algae. II. Parasites of Desmidiaceae

Directory of Open Access Journals (Sweden)

Joanna Z. Kadłubowska

2014-08-01

Full Text Available Investigations carried out on the Desmidiaceae revealed the following species of fungi parasitizing on desmids: Myzocytium megastomum, Lagenidium closterii, Ancylistes closterii and Rhizophydium globosum. Legenidium closterii is new in Poland. It is the first information of this species as a parasite on the algae from the genus Tetmemorus. Figures of sporangia of Rhizophydium globosum on Euastrum ansatum, Cosmarium botrytis, C. pseudamoenum and a resting spore on Staurastrum punctulatum are the first graphic documentation of this species.

21 CFR 99.401 - Corrective actions and cessation of dissemination of information.

Science.gov (United States)

2010-04-01

... HEALTH AND HUMAN SERVICES GENERAL DISSEMINATION OF INFORMATION ON UNAPPROVED/NEW USES FOR MARKETED DRUGS... cessation of dissemination of information. (a) FDA actions based on post dissemination data. If FDA receives... requirements; or (2) Order the manufacturer to cease dissemination of information and to take corrective action...

Passive transfer of resistance and the site of immune-dependent elimination of the challenge infection in rats vaccinated with highly irradiated cercariae of Schistosoma mansoni

International Nuclear Information System (INIS)

Ford, M.J.; Bickle, Q.D.; Taylor, M.G.; Andrews, B.J.

1984-01-01

The immune-dependent elimination of a challenge infection in rats vaccinated with highly-irradiated cercariae of Schistosoma mansoni was analysed by passive transfer of serum, recovery of the challenge from the lungs and livers and by transferring lung-stage schistosomula. Recipients of serum from rats immunized with either unirradiated, 20 or 40 krad.-irradiated cercariae, were equally resistant if the serum was injected on the day of infection or 5-7 days after infection. Vaccinated rat serum transferred to mice and vaccinated rabbit serum transferred to rats conferred comparable protection when injected on day 0 or 5 days after infection of the recipients. This apparent susceptibility of the lung schistosomula to immune attack was confirmed by challenging 20 or 40 krad.-irradiated cercariae vaccinated rats with lung-stage schistosomula derived from mice or rats. All the detectable attrition of a cercarial challenge in vaccinated rats occurred between 7 and 10 days post-challenge, before the parasites reached the liver. Since there was no evidence of damage or attrition in the skin or lungs before day 7 it was concluded that immune-dependent elimination occurred rapidly following a 'window of sensitivity' coinciding with the migration of the parasites from the lungs to the liver. (author)

Host-Parasite Interactions from the Inside: Plant Reproductive Ontogeny Drives Specialization in Parasitic Insects.

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Thomas Boivin

Full Text Available Host plant interactions are likely key drivers of evolutionary processes involved in the diversification of phytophagous insects. Granivory has received substantial attention for its crucial role in shaping the interaction between plants and their seed parasites, but fine-scale mechanisms explaining the role of host plant reproductive biology on specialization of seed parasites remain poorly described. In a comparative approach using plant histological techniques, we tested the hypotheses that different seed parasite species synchronize their life cycles to specific stages in seed development, and that the stage they target depends on major differences in seed development programs. In a pinaceous system, seed storage products are initiated before ovule fertilization and the wasps target the ovule's nucellus during megagametogenesis, a stage at which larvae may benefit from the by-products derived from both secreting cells and dying nucellar cells. In a cupressaceous system, oviposition activity peaks later, during embryogenesis, and the wasps target the ovule's megagametophyte where larvae may benefit from cell disintegration during embryogenesis. Our cytohistological approach shows for the first time how, despite divergent oviposition targets, different parasite species share a common strategy that consists of first competing for nutrients with developing plant structures, and then consuming these developed structures to complete their development. Our results support the prediction that seed developmental program is an axis for specialization in seed parasites, and that it could be an important parameter in models of their ecological and taxonomic divergence. This study provides the basis for further investigating the possibility of the link between plant ontogeny and pre-dispersal seed parasitism.

Effective and specific in planta RNAi in cyst nematodes: expression interference of four parasitism genes reduces parasitic success.

Science.gov (United States)

Sindhu, Anoop S; Maier, Tom R; Mitchum, Melissa G; Hussey, Richard S; Davis, Eric L; Baum, Thomas J

2009-01-01

Cyst nematodes are highly evolved sedentary plant endoparasites that use parasitism proteins injected through the stylet into host tissues to successfully parasitize plants. These secretory proteins likely are essential for parasitism as they are involved in a variety of parasitic events leading to the establishment of specialized feeding cells required by the nematode to obtain nourishment. With the advent of RNA interference (RNAi) technology and the demonstration of host-induced gene silencing in parasites, a new strategy to control pests and pathogens has become available, particularly in root-knot nematodes. Plant host-induced silencing of cyst nematode genes so far has had only limited success but similarly should disrupt the parasitic cycle and render the host plant resistant. Additional in planta RNAi data for cyst nematodes are being provided by targeting four parasitism genes through host-induced RNAi gene silencing in transgenic Arabidopsis thaliana, which is a host for the sugar beet cyst nematode Heterodera schachtii. Here it is reported that mRNA abundances of targeted nematode genes were specifically reduced in nematodes feeding on plants expressing corresponding RNAi constructs. Furthermore, this host-induced RNAi of all four nematode parasitism genes led to a reduction in the number of mature nematode females. Although no complete resistance was observed, the reduction of developing females ranged from 23% to 64% in different RNAi lines. These observations demonstrate the relevance of the targeted parasitism genes during the nematode life cycle and, potentially more importantly, suggest that a viable level of resistance in crop plants may be accomplished in the future using this technology against cyst nematodes.

Acute disseminated candidiasis with skin lesions: a systematic review.

Science.gov (United States)

Guarana, M; Nucci, M

2018-03-01

Neutropenic patients developing acute disseminated candidiasis may present with skin lesions. To evaluate the epidemiology of acute disseminated candidiasis with skin lesions in neutropenic patients, taking into consideration changes caused by different prophylactic strategies. A systematic review of English-language articles found via PubMed (1963-2016) was performed. We asked the following questions: (a) What Candida species are more frequently involved in this syndrome? (b) Has antifungal prophylaxis changed the species causing skin lesions? (c) What are the typical patterns of skin lesions? (d) What is the frequency of skin lesions in neutropenic patients with candidaemia or acute disseminated candidiasis? (e) Has antifungal prophylaxis decreased the incidence of acute disseminated candidiasis with skin lesions? Among 183 studies, 33 were selected, reporting 100 cases of acute disseminated candidiasis with skin lesions in neutropenic patients. It occurred more frequently in the setting of induction therapy for de novo or relapsed acute leukaemia, and the most frequent Candida species were C. tropicalis (68%) and C. krusei (15%). Diffuse maculopapular lesions predominated in cases caused by C. tropicalis and nodular and papular lesions in cases caused by C. krusei. Prophylaxis with fluconazole was reported in six cases, C. krusei in five and C. ciferrii in one. The death rate was 45.4%. Two patterns were recognized: disseminated maculopapular lesions caused by C. tropicalis in patients not receiving fluconazole prophylaxis, occurring in 39% to 44% of neutropenic patients with acute disseminated candidiasis, and nodular lesions caused by C. krusei in patients receiving fluconazole prophylaxis, occurring less frequently. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Parasites and steroid hormones: corticosteroid and sex steroid synthesis, their role in the parasite physiology and development.

Directory of Open Access Journals (Sweden)

Marta C. Romano

2015-06-01

Full Text Available In many cases parasites display highly complex life cycles that include establishment of the larva or adults within host organs, but even in those that have only one host reciprocal intricate interactions occur. A bulk of evidence indicates that steroid hormones influence the development and course of parasitic infections, the host gender susceptibility to the infection and the associate differences in immunological response are good examples of the host-parasite interplay. However, the capacity of these organisms to synthesize their own steroidogenic hormones still has more questions than answers. It is now well known that many parasites synthesize ecdysteroids, but limited information is available on sex steroid and corticosteroid synthesis. This review intends to summarize some of the existing information in the field. In many but not all parasitosis the host hormonal environment determines the susceptibility, the course and severity of parasite infections. In most cases the infection disturbs the host environment, and activate immune responses that finally affect the endocrine system. Furthermore, sex steroids and corticosteroids may also directly modify the parasite reproduction and molting. Available information indicates that parasites synthesize some steroid hormones like ecdysteroids and sex steroids and the presence and activity of related enzymes have been demonstrated. More recently, the synthesis of corticosteroid like compounds has been shown in Taenia solium and tapeworms and in Taenia crassiceps WFU cysticerci. Deeper knowledge of the endocrine properties of parasites will contribute to understand their reproduction and reciprocal interactions with the host, and also may contribute to design tools to combat the infection in some clinical situations.

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.

Considering RNAi experimental design in parasitic helminths.

Science.gov (United States)

Dalzell, Johnathan J; Warnock, Neil D; McVeigh, Paul; Marks, Nikki J; Mousley, Angela; Atkinson, Louise; Maule, Aaron G

2012-04-01

Almost a decade has passed since the first report of RNA interference (RNAi) in a parasitic helminth. Whilst much progress has been made with RNAi informing gene function studies in disparate nematode and flatworm parasites, substantial and seemingly prohibitive difficulties have been encountered in some species, hindering progress. An appraisal of current practices, trends and ideals of RNAi experimental design in parasitic helminths is both timely and necessary for a number of reasons: firstly, the increasing availability of parasitic helminth genome/transcriptome resources means there is a growing need for gene function tools such as RNAi; secondly, fundamental differences and unique challenges exist for parasite species which do not apply to model organisms; thirdly, the inherent variation in experimental design, and reported difficulties with reproducibility undermine confidence. Ideally, RNAi studies of gene function should adopt standardised experimental design to aid reproducibility, interpretation and comparative analyses. Although the huge variations in parasite biology and experimental endpoints make RNAi experimental design standardization difficult or impractical, we must strive to validate RNAi experimentation in helminth parasites. To aid this process we identify multiple approaches to RNAi experimental validation and highlight those which we deem to be critical for gene function studies in helminth parasites.

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.

Parasite stress promotes homicide and child maltreatment

Science.gov (United States)

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

Gastrointestinal parasite infection of the Gray mouse lemur ...

African Journals Online (AJOL)

Faecal material from 169 individuals of Microcebus murinus living in five littoral forest fragments was analyzed for gastrointestinal parasites. The fragments differed in size and forest quality. Gastrointestinal parasite infection of M. murinus was characterised using parasite species richness, the prevalence of parasites, and ...

Health information dissemination for breast cancer awareness, early ...

African Journals Online (AJOL)

This study is to explore how information about breast cancer (BC) is disseminated to working class mothers in Lagos State. It is to investigate how information disseminated is used by the respondents to detect early this deadly disease and ascertain if they are aware of any support by organisation and the government.

Mechanisms of CNS invasion and damage by parasites.

Science.gov (United States)

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.

Immune escape strategies of malaria parasites

Directory of Open Access Journals (Sweden)

Pollyanna Stephanie Gomes

2016-10-01

Full Text Available Malaria is one of the most life-threatening infectious diseases worldwide. Immunity to malaria is slow and short-lived despite the repeated parasite exposure in endemic areas. Malaria parasites have evolved refined machinery to evade the immune system based on a range of genetic changes that include allelic variation, biomolecular exposure of proteins and intracellular replication. All of these features increase the probability of survival in both mosquitoes and the vertebrate host. Plasmodium species escape from the first immunological trap in its invertebrate vector host, the Anopheles mosquitoes. The parasites have to pass through various immunological barriers within the mosquito such as anti-microbial molecules and the mosquito microbiota in order to achieve successful transmission to the vertebrate host. Within these hosts, Plasmodium species employ various immune evasion strategies during different life cycle stages. Parasite persistence against the vertebrate immune response depends on the balance among virulence factors, pathology, metabolic cost of the host immune response, and the parasites ability to evade the immune response. In this review we discuss the strategies that Plasmodium parasites use to avoid the vertebrate host immune system and how they promote successful infection and transmission.

Intrathecal chemotherapy for refractory disseminated medulloblastoma.

Science.gov (United States)

Yoshimura, Junichi; Nishiyama, Kenichi; Mori, Hiroshi; Takahashi, Hideaki; Fujii, Yukihiko

2008-05-01

To analyze the effect of intrathecal (IT) chemotherapy for disseminated medulloblastoma. Twenty-one patients received IT chemotherapy using the chemotherapeutic agents of methotrexate (MTX) and nitrosoureas (ACNU, MCNU) including nine patients for residual leptomeningeal lesions after initial surgery and radiation, and 12 for a recurrence with leptomeningeal dissemination. Of these 21 patients, 12 received a lumbar and/or ventricular bolus injection of the chemotherapeutic agents, one received the ventriculolumbar perfusion of the agents, and eight received both the perfusion and bolus injection. The doses ranged from 6-7 mg/m(2) of ACNU for perfusion and 3-3.5 mg/m(2) of ACNU, MCNU, or MTX for the bolus injection, and the cycles were administered from 3 to 12 times for perfusion and from 5 to 54 times for the bolus injection. The effects of chemotherapy were assessed by both radiological and cytological examinations, and the clinical symptoms were also assessed. Radiological and/or cytological responses were observed in 10 of 21 patients (47.6%), including seven cases demonstrating a complete remission. The 5-year overall survival rate and 5-year survival rate after dissemination were 61.5 and 46.4%, respectively. Five patients who received a lumbar bolus injection of nitrosoureas experienced paraplegia and double incontinence. One patient who received a ventricular injection of nitrosoureas experienced truncal ataxia. IT chemotherapy was found to be effective in some cases with refractory disseminated medulloblastoma and it seems to be an appropriate treatment choice for leptomeningeal recurrence. However, the frequent bolus injections of nitrosoureas should be avoided to prevent the side effects.

New mechanisms of disease and parasite-host interactions.

Science.gov (United States)

de Souza, Tiago Alves Jorge; de Carli, Gabriel Jose; Pereira, Tiago Campos

2016-09-01

An unconventional interaction between a patient and parasites was recently reported, in which parasitic cells invaded host's tissues, establishing several tumors. This finding raises various intriguing hypotheses on unpredicted forms of interplay between a patient and infecting parasites. Here we present four unusual hypothetical host-parasite scenarios with intriguing medical consequences. Relatively simple experimental designs are described in order to evaluate such hypotheses. The first one refers to the possibility of metabolic disorders in parasites intoxicating the host. The second one is on possibility of patients with inborn errors of metabolism (IEM) being more resistant to parasites (due to accumulation of toxic compounds in the bloodstream). The third one refers to a mirrored scenario: development of tumors in parasites due to ingestion of host's circulating cancer cells. The last one describes a complex relationship between parasites accumulating a metabolite and supplying it to a patient with an IEM. Copyright © 2016 Elsevier Ltd. All rights reserved.

Clinico-pathological studies of CSF dissemination of glioblastoma and medulloblastoma

International Nuclear Information System (INIS)

Kato, Kyozo; Yoshida, Jun; Kageyama, Naoki

1986-01-01

Clinico-pathological findings of CSF dissemination which was diagnosed on CT scan, were studied on 13 cases of glioblastoma and 9 cases of medulloblastoma. The type of CSF dissemination and the prognosis of patients were both different between glioblastoma and medulloblastoma. In the former, the dissemination was predominantly in ventricular walls and in the latter, in basal cisterns. The mean survival time after the diagnosis of dissemination is 6 months of glioblastoma as compared with 13 months of medulloblastoma. The Pathological studies show that subependymal and/or subpial infiltration of tumor cells, and thickness of arachnoid membrane by marked mesodermal reaction were demonstrated in cases of glioblastoma. On the contrary, tumor cells of medulloblastoma grow markedly in the subarachnoid space and/or on the ependymal layers. From these pathological findings of CSF dissemination, it will be resulted that the prognosis of glioblastoma is much more poor that of medulloblastoma. (author)

Parasites in food webs: the ultimate missing links

Science.gov (United States)

Lafferty, Kevin D.; Allesina, Stefano; Arim, Matias; Briggs, Cherie J.; De Leo, Giulio A.; Dobson, Andrew P.; Dunne, Jennifer A.; Johnson, Pieter T.J.; Kuris, Armand M.; Marcogliese, David J.; Martinez, Neo D.; Memmott, Jane; Marquet, Pablo A.; McLaughlin, John P.; Mordecai, Eerin A.; Pascual, Mercedes; Poulin, Robert; Thieltges, David W.

2008-01-01

Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists.

Hepatozoon parasites (Apicomplexa: Adeleorina) in bats.

Science.gov (United States)

Pinto, C Miguel; Helgen, Kristofer M; Fleischer, Robert C; Perkins, Susan L

2013-08-01

We provide the first evidence of Hepatozoon parasites infecting bats. We sequenced a short fragment of the 18S rRNA gene (~600 base pairs) of Hepatozoon parasites from 3 Hipposideros cervinus bats from Borneo. Phylogenies inferred by model-based methods place these Hepatozoon within a clade formed by parasites of reptiles, rodents, and marsupials. We discuss the scenario that bats might be common hosts of Hepatozoon.

34 CFR 668.44 - Availability of employees for information dissemination purposes.

Science.gov (United States)

2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Availability of employees for information dissemination... information dissemination purposes. (a) Availability. (1) Except as provided in paragraph (b) of this section... insufficient demand for information dissemination services among its enrolled or prospective students to...

Disseminated Histoplasmosis in a 13-year-old girl: A case report ...

African Journals Online (AJOL)

Background: Disseminated histoplasmosis is a rare fungal infection and most documented cases are in immunecompromised individuals such as those with acquired immuno-deficiency syndrome. Objective: To describe a case of disseminated histoplasmosis in an adolescent girl. Method: We report a case of disseminated ...

Herpes zoster (shingles) disseminated (image)

Science.gov (United States)

Herpes zoster (shingles) normally occurs in a limited area that follows a dermatome (see the "dermatome" picture). In individuals with damaged immune systems, herpes zoster may be widespread (disseminated), causing serious illness. ...

Parasitism, personality and cognition in fish.

Science.gov (United States)

Barber, I; Mora, A B; Payne, E M; Weinersmith, K L; Sih, A

2017-08-01

It is well established that parasites can have profound effects on the behaviour of host organisms, and that individual differences in behaviour can influence susceptibility to parasite infections. Recently, two major themes of research have developed. First, there has been a growing interest in the proximate, mechanistic processes underpinning parasite-associated behaviour change, and the interactive roles of the neuro-, immune, and other physiological systems in determining relationships between behaviour and infection susceptibility. Secondly, as the study of behaviour has shifted away from one-off measurements of single behaviours and towards a behavioural syndromes/personality framework, research is starting to focus on the consequences of parasite infection for temporal and contextual consistency of behaviour, and on the implications of different personality types for infection susceptibility. In addition, there is increasing interest in the potential for relationships between cognition and personality to also have implications for host-parasite interactions. As models well-suited to both the laboratory study of behaviour and experimental parasitology, teleost fish have been used as hosts in many of these studies. In this review we provide a broad overview of the range of mechanisms that potentially generate links between fish behaviour, personality, and parasitism, and illustrate these using examples drawn from the recent literature. In addition, we examine the potential interactions between cognition, personality and parasitism, and identify questions that may be usefully investigated with fish models. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Cassandra - D7.3.4 - M24 status report dissemination results

NARCIS (Netherlands)

Klievink, A.J.

2013-01-01

This deliverable is a status report on the dissemination activities and results in the CASSANDRA project. These status reports are made regularly, with two more to come. Together, these make up deliverable D7.3 – Dissemination results. In this fifth report, the results of the dissemination

Parasites in the Wadden Sea food web

Science.gov (United States)

Thieltges, David W.; Engelsma, Marc Y.; Wendling, Carolin C.; Wegner, K. Mathias

2013-09-01

While the free-living fauna of the Wadden Sea has received much interest, little is known on the distribution and effects of parasites in the Wadden Sea food web. However, recent studies on this special type of trophic interaction indicate a high diversity of parasites in the Wadden Sea and suggest a multitude of effects on the hosts. This also includes effects on specific predator-prey relationships and the general structure of the food web. Focussing on molluscs, a major group in the Wadden Sea in terms of biomass and abundance and an important link between primary producers and predators, we review existing studies and exemplify the ecological role of parasites in the Wadden Sea food web. First, we give a brief inventory of parasites occurring in the Wadden Sea, ranging from microparasites (e.g. protozoa, bacteria) to macroparasites (e.g. helminths, parasitic copepods) and discuss the effects of spatial scale on heterogeneities in infection levels. We then demonstrate how parasites can affect host population dynamics by acting as a strong mortality factor, causing mollusc mass mortalities. In addition, we will exemplify how parasites can mediate the interaction strength of predator-prey relationships and affect the topological structure of the Wadden Sea food web as a whole. Finally, we highlight some ongoing changes regarding parasitism in the Wadden Sea in the course of global change (e.g. species introduction, climate change) and identify important future research questions to entangle the role of parasites in the Wadden Sea food web.

Identifying the challenges of creating an optimal dissemination ...

African Journals Online (AJOL)

It is crucial that census data is disseminated in such a way that it satisfies most user needs as far as possible, to ensure that there is optimum use of the information and that maximum value for money is provided. In the past, Statistics South Africa disseminated data at the same geographic level created for data collection.

Parasite transmission in a natural multihost–multiparasite community

Science.gov (United States)

2017-01-01

Understanding the transmission and dynamics of infectious diseases in natural communities requires understanding the extent to which the ecology, evolution and epidemiology of those diseases are shaped by alternative hosts. We performed laboratory experiments to test how parasite spillover affected traits associated with transmission in two co-occurring parasites: the bacterium Pasteuria ramosa and the fungus Metschnikowia bicuspidata. Both parasites were capable of transmission from the reservoir host (Daphnia dentifera) to the spillover host (Ceriodaphnia dubia), but this occurred at a much higher rate for the fungus than the bacterium. We quantified transmission potential by combining information on parasite transmission and growth rate, and used this to compare parasite fitness in the two host species. For both parasites, transmission potential was lower in the spillover host. For the bacterium, virulence was higher in the spillover host. Transmission back to the original host was high for both parasites, with spillover influencing transmission rate of the fungus but not the bacterium. Thus, while inferior, the spillover host is not a dead-end for either parasite. Overall, our results demonstrate that the presence of multiple hosts in a community can have important consequences for disease transmission, and host and parasite fitness. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289264

Parasite transmission in a natural multihost-multiparasite community.

Science.gov (United States)

Auld, Stuart K J R; Searle, Catherine L; Duffy, Meghan A

2017-05-05

Understanding the transmission and dynamics of infectious diseases in natural communities requires understanding the extent to which the ecology, evolution and epidemiology of those diseases are shaped by alternative hosts. We performed laboratory experiments to test how parasite spillover affected traits associated with transmission in two co-occurring parasites: the bacterium Pasteuria ramosa and the fungus Metschnikowia bicuspidata Both parasites were capable of transmission from the reservoir host ( Daphnia dentifera ) to the spillover host ( Ceriodaphnia dubia ), but this occurred at a much higher rate for the fungus than the bacterium. We quantified transmission potential by combining information on parasite transmission and growth rate, and used this to compare parasite fitness in the two host species. For both parasites, transmission potential was lower in the spillover host. For the bacterium, virulence was higher in the spillover host. Transmission back to the original host was high for both parasites, with spillover influencing transmission rate of the fungus but not the bacterium. Thus, while inferior, the spillover host is not a dead-end for either parasite. Overall, our results demonstrate that the presence of multiple hosts in a community can have important consequences for disease transmission, and host and parasite fitness.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'. © 2017 The Author(s).

Gastrointestinal function in the parasitized host

International Nuclear Information System (INIS)

Castro, G.A.

1981-01-01

Emphasis in this review is on (1) digestive-absorptive, secretory and smooth muscle functions altered by gastrointestinal (GI) parasites, (2) mechanisms by which parasites induce changes, and (3) the influence of parasite-induced alterations on the health of the host. Examples involving laboratory and domestic animals indicate that inflammation is an important factor in pathological alterations in epithelial and smooth muscle tissues throughout the alimentary canal. Observations on GI secretory activity reveal an influence of parasites on the host GI endocrine system. It is argued that assessments of the significance of parasite-induced changes on the host must be balanced with the adaptive potential and 'reserve capacity' of the GI system. In this regard host immunity should be considered a specific adaptation. Some tracer studies are mentioned marginally, such as the use of 14 C polyethylene glycol to estimate the direction of not fluid movement in the small intestine, and the use of 51 Cr to demonstrate the significantly faster intestinal transit in Trichinella spiralis infected animals

Host defence against disseminated and invasive candida albicans infections.

NARCIS (Netherlands)

Vonk, A.G.

2004-01-01

The yeast Candida albicans is the primary etiologic agent of disseminated and invasive candidiasis. The incidence of disseminated and invasive candidiasis has paralleled the use of modern medical procedures that adversely affect the immune system, and highlights the difficulty of treating

Targeted mutagenesis in a human-parasitic nematode

Science.gov (United States)

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

Helminth parasites alter protection against Plasmodium infection.

Science.gov (United States)

Salazar-Castañon, Víctor H; Legorreta-Herrera, Martha; Rodriguez-Sosa, Miriam

2014-01-01

More than one-third of the world's population is infected with one or more helminthic parasites. Helminth infections are prevalent throughout tropical and subtropical regions where malaria pathogens are transmitted. Malaria is the most widespread and deadliest parasitic disease. The severity of the disease is strongly related to parasite density and the host's immune responses. Furthermore, coinfections between both parasites occur frequently. However, little is known regarding how concomitant infection with helminths and Plasmodium affects the host's immune response. Helminthic infections are frequently massive, chronic, and strong inductors of a Th2-type response. This implies that infection by such parasites could alter the host's susceptibility to subsequent infections by Plasmodium. There are a number of reports on the interactions between helminths and Plasmodium; in some, the burden of Plasmodium parasites increased, but others reported a reduction in the parasite. This review focuses on explaining many of these discrepancies regarding helminth-Plasmodium coinfections in terms of the effects that helminths have on the immune system. In particular, it focuses on helminth-induced immunosuppression and the effects of cytokines controlling polarization toward the Th1 or Th2 arms of the immune response.

Mechanisms of cellular invasion by intracellular parasites.

Science.gov (United States)

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 suspected parasite spill-back of two novel Myxidium spp. (Myxosporea causing disease in Australian endemic frogs found in the invasive Cane toad.

Directory of Open Access Journals (Sweden)

Ashlie Hartigan

Full Text Available Infectious diseases are contributing to the decline of endangered amphibians. We identified myxosporean parasites, Myxidium spp. (Myxosporea: Myxozoa, in the brain and liver of declining native frogs, the Green and Golden Bell frog (Litoria aurea and the Southern Bell frog (Litoria raniformis. We unequivocally identified two Myxidium spp. (both generalist affecting Australian native frogs and the invasive Cane toad (Bufo marinus, syn. Rhinella marina and demonstrated their association with disease. Our study tested the identity of Myxidium spp. within native frogs and the invasive Cane toad (brought to Australia in 1935, via Hawaii to resolve the question whether the Cane toad introduced them to Australia. We showed that the Australian brain and liver Myxidium spp. differed 9%, 7%, 34% and 37% at the small subunit rDNA, large subunit rDNA, internal transcribed spacers 1 and 2, but were distinct from Myxidium cf. immersum from Cane toads in Brazil. Plotting minimum within-group distance against maximum intra-group distance confirmed their independent evolutionary trajectory. Transmission electron microscopy revealed that the brain stages localize inside axons. Myxospores were morphologically indistinguishable, therefore genetic characterisation was necessary to recognise these cryptic species. It is unlikely that the Cane toad brought the myxosporean parasites to Australia, because the parasites were not found in 261 Hawaiian Cane toads. Instead, these data support the enemy-release hypothesis predicting that not all parasites are translocated with their hosts and suggest that the Cane toad may have played an important spill-back role in their emergence and facilitated their dissemination. This work emphasizes the importance of accurate species identification of pathogens relevant to wildlife management and disease control. In our case it is paving the road for the spill-back role of the Cane toad and the parasite emergence.

Predicting what helminth parasites a fish species should have using Parasite Co-occurrence Modeler (PaCo)

Science.gov (United States)

Strona, Giovanni; Lafferty, Kevin D.

2013-01-01

Fish pathologists are often interested in which parasites would likely be present in a particular host. Parasite Co-occurrence Modeler (PaCo) is a tool for identifying a list of parasites known from fish species that are similar ecologically, phylogenetically, and geographically to the host of interest. PaCo uses data from FishBase (maximum length, growth rate, life span, age at maturity, trophic level, phylogeny, and biogeography) to estimate compatibility between a target host and parasite species–genera from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, and Trematoda). Users can include any combination of host attributes in a model. These unique features make PaCo an innovative tool for addressing both theoretical and applied questions in parasitology. In addition to predicting the occurrence of parasites, PaCo can be used to investigate how host characteristics shape parasite communities. To test the performance of the PaCo algorithm, we created 12,400 parasite lists by applying any possible combination of model parameters (248) to 50 fish hosts. We then measured the relative importance of each parameter by assessing their frequency in the best models for each host. Host phylogeny and host geography were identified as the most important factors, with both present in 88% of the best models. Habitat (64%) was identified in more than half of the best models. Among ecological parameters, trophic level (41%) was the most relevant while life span (34%), growth rate (32%), maximum length (28%), and age at maturity (20%) were less commonly linked to best models. PaCo is free to use at www.purl.oclc.org/fishpest.

Sex as a strategy against rapidly evolving parasites.

Science.gov (United States)

Auld, Stuart K J R; Tinkler, Shona K; Tinsley, Matthew C

2016-12-28

Why is sex ubiquitous when asexual reproduction is much less costly? Sex disrupts coadapted gene complexes; it also causes costs associated with mate finding and the production of males who do not themselves bear offspring. Theory predicts parasites select for host sex, because genetically variable offspring can escape infection from parasites adapted to infect the previous generations. We examine this using a facultative sexual crustacean, Daphnia magna, and its sterilizing bacterial parasite, Pasteuria ramosa We obtained sexually and asexually produced offspring from wild-caught hosts and exposed them to contemporary parasites or parasites isolated from the same population one year later. We found rapid parasite adaptation to replicate within asexual but not sexual offspring. Moreover, sexually produced offspring were twice as resistant to infection as asexuals when exposed to parasites that had coevolved alongside their parents (i.e. the year two parasite). This fulfils the requirement that the benefits of sex must be both large and rapid for sex to be favoured by selection. © 2016 The Author(s).

Not the last word: dissemination strategies for patient-centred research in nursing.

Science.gov (United States)

Hagan, Teresa L; Schmidt, Karen; Ackison, Guyanna R; Murphy, Megan; Jones, Jennifer R

2017-08-01

Research results hold value for many stakeholders including researchers, patient populations, advocacy organizations, and community groups. The aim of this study is to describe our research team's systematic process to designing a dissemination strategy for a completed research study. We organized a dissemination event to feed the results of our study to participants and stakeholders and collect feedback regarding our study. We applied the Agency for Healthcare Research and Quality's dissemination framework to guide the development of the event and collected participant feedback during the event. We describe our dissemination strategy along with attendees' feedback and suggestions for our research as an example of a way to design a patient- and community-focused dissemination. We explain the details of our dissemination strategy including (a) our process of reporting a large research study into a stakeholder event, (b) stakeholder feedback collected at the event, and (c) the translation of feedback into our research team's research. We also describe challenges encountered during the dissemination process and ways to handle issues such as logistics, funding, and staff. This analysis provides key insights and practical advice for researchers looking for innovative ways to disseminate their findings within the lay and scientific communities.

An investigation of parasitic infections and review of molecular characterization of the intestinal protozoa in nonhuman primates in China from 2009 to 2015

Directory of Open Access Journals (Sweden)

Junqiang Li

2017-04-01

Full Text Available Parasites are a well-known threat to nonhuman primate (NHP populations, and potentially cause zoonotic diseases in humans. In this study, the basic data was provided of the parasites in NHPs and the molecular characterization of the Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. were reviewed, which were found in these samples. A total of 3349 fecal samples were collected from 34 species reared at 17 districts in zoos, farms, free-range, or research laboratories, and examined microscopically. Eleven genera of intestinal parasites were detected: five genera of protozoans (Isospora spp., Entamoeba spp., Giardia sp., Cryptosporidium spp., and Cyclospora spp. and six genera of helminths (Trichuris spp., Strongyloides spp., Ascaris spp., Physaloptera spp., Ancylostoma spp., and Enterobius spp.. The overall sample prevalence of parasitic infection was 54.1% (1811/3349. Entamoeba spp. was the most prevalent (36.4%, 1218/3349. The infection rate was the highest in free-range animals (73.0%, 670/918 (P < 0.01 and Guangxi Zhuang autonomous region (64.8%, 566/873. Mixed infections were mostly detected for Entamoeba spp., Trichuris spp., and Strongyloides spp.. Molecular characterization was reviewed of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp., as these are zoonotic species or genotypes. This parasitological data for NHPs in China, provides important information for veterinarians and public health authorities for the elimination of such parasites and monitor the potential transmission of zoonotic infections from NHPs.

Fair and adaptive data dissemination for traffic information systems

NARCIS (Netherlands)

de Souza Schwartz, Ramon; Ohazulike, Anthony; Sommer, Christoph; Scholten, Johan; Dressler, Falko; Havinga, Paul J.M.; IEEE,

2012-01-01

Vehicular Ad-hoc Networks (VANETs) are expected to serve as support to the development of not only safety applications but also information-rich applications that disseminate relevant data to vehicles. Due to the continuous collection, processing, and dissemination of data, one crucial requirement

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

From Fossil Parasitoids to Vectors: Insects as Parasites and Hosts.

Science.gov (United States)

Nagler, Christina; Haug, Joachim T

2015-01-01

Within Metazoa, it has been proposed that as many as two-thirds of all species are parasitic. This propensity towards parasitism is also reflected within insects, where several lineages independently evolved a parasitic lifestyle. Parasitic behaviour ranges from parasitic habits in the strict sense, but also includes parasitoid, phoretic or kleptoparasitic behaviour. Numerous insects are also the host for other parasitic insects or metazoans. Insects can also serve as vectors for numerous metazoan, protistan, bacterial and viral diseases. The fossil record can report this behaviour with direct (parasite associated with its host) or indirect evidence (insect with parasitic larva, isolated parasitic insect, pathological changes of host). The high abundance of parasitism in the fossil record of insects can reveal important aspects of parasitic lifestyles in various evolutionary lineages. For a comprehensive view on fossil parasitic insects, we discuss here different aspects, including phylogenetic systematics, functional morphology and a direct comparison of fossil and extant species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pathoecology of Chiribaya parasitism

Directory of Open Access Journals (Sweden)

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.

[Disseminated cryptococcosis in an immunocompetent patient].

Science.gov (United States)

Elkhihal, B; Hasnaoui, A; Ghfir, I; Moustachi, A; Aoufi, S; Lyagoubi, M

2015-09-01

Disseminated cryptococcosis is a serious opportunistic fungal infection caused by a yeast-encapsulated fungus of the genus Cryptococcus neoformans. It occurs most often in patients with a significant deficit of cellular immunity and preferentially affects the central nervous system. The skin and the lungs are the most commonly affected sites outside the neuro-subarachnoid location. We report the case of a patient apparently immunocompetent who had a disseminated cryptococcosis. The disease started with the multiple purplish skin lesions, large umbilicated on the face, groin, forearm and leg with progressively increasing volume. This symptomatology had evolved in the context of weight loss and poor general condition. The diagnosis was established by the presence of cryptococcal at the skin biopsy and cerebrospinal fluid. Research of immunosuppression common pathologies were negative. Treatment was initiated based on amphotericin B for 40 days. The patient's condition deteriorates onset of paraplegia and swallowing disorders causing death in an array of cachexia. This observation points out that disseminated cryptococcosis can occur in an immunocompetent patient. The skin lesions may be the first sign of the disease. Copyright © 2015. Published by Elsevier Masson SAS.

Parasites and parasite management practices of organic and conventional dairy herds in Minnesota.

Science.gov (United States)

Sorge, U S; Moon, R D; Stromberg, B E; Schroth, S L; Michels, L; Wolff, L J; Kelton, D F; Heins, B J

2015-05-01

The objective of this study was to describe the prevalence and practices used to manage internal helminth parasites and external arthropod parasites on organic and conventional dairy herds in Minnesota. All organic (ORG) dairy herds in Minnesota (n=114) and a convenience sample of conventional herds were invited to participate in the study. Thirty-five ORG herds and 28 conventional herds were visited once in summer and fall of 2012. Conventional dairy herds were split into small conventional (SC,conventional herds (MC, ≥200 cows) so that SC herds were comparable in size to the ORG herds. Dairy managers were surveyed to assess their farm management practices and perceptions about parasites, hygiene scores were recorded for adult stock, and fecal samples were collected from a nominal 20 breeding-age heifers to characterize abundance of internal parasites. Nonparametric tests were used to compare fecal egg counts per gram (FEC) among farms grouped by management systems and practices. Organic farms had more designated pasture and were more likely to use rotational grazing compared with conventional farms, but the stocking densities of animals on pasture were similar among farm types. The overall FEC were very low, and only a few individual ORG heifers had FEC >500 eggs/gram. Samples from heifers on ORG farms had significantly more strongyle-type eggs than those on SC and MC farms (ORG: 6.6±2.1; SC: 0.5±0.3; MC: 0.8±0.7), but egg counts of other types of gastrointestinal parasites did not differ significantly among the 3 herd groups. Fly control measures were applied mainly to milking cows and preweaned calves and were used on 88.6% of ORG herds, 60.0% of SC herds, and 91.7% of MC herds. Approximately half of the producers reported having seen skin conditions suggestive of lice or tail mange in their cattle during the previous winter (ORG: 48.6%, SC: 57.1%, MC: 53.9%). Although most conventional producers reported treating these skin conditions, most organic

Quantitative Analysis of a Parasitic Antiviral Strategy

OpenAIRE

Kim, Hwijin; Yin, John

2004-01-01

We extended a computer simulation of viral intracellular growth to study a parasitic antiviral strategy that diverts the viral replicase toward parasite growth. This strategy inhibited virus growth over a wide range of conditions, while minimizing host cell perturbations. Such parasitic strategies may inhibit the development of drug-resistant virus strains.

Parasites and vectors carry no passport: how to fund cross-border and regional efforts to achieve malaria elimination

Directory of Open Access Journals (Sweden)

Gueye Cara

2012-10-01

Full Text Available Abstract Background Tremendous progress has been made in the last ten years in reducing morbidity and mortality caused by malaria, in part because of increases in global funding for malaria control and elimination. Today, many countries are striving for malaria elimination. However, a major challenge is the neglect of cross-border and regional initiatives in malaria control and elimination. This paper seeks to better understand Global Fund support for multi-country initiatives. Methods Documents and proposals were extracted and reviewed from two main sources, the Global Fund website and Aidspan.org. Documents and reports from the Global Fund Technical Review Panel, Board, and Secretariat documents such as guidelines and proposal templates were reviewed to establish the type of policies enacted and guidance provided from the Global Fund on multi-country initiatives and applications. From reviewing this information, the researchers created 29 variables according to eight dimensions to use in a review of Round 10 applications. All Round 10 multi-country applications (for HIV, malaria and tuberculosis and all malaria multi-country applications (6 from Rounds 1 – 10 were extracted from the Global Fund website. A blind review was conducted of Round 10 applications using the 29 variables as a framework, followed by a review of four of the six successful malaria multi-country grant applications from Rounds 1 – 10. Findings During Rounds 3 – 10 of the Global Fund, only 5.8% of grants submitted were for multi-country initiatives. Out of 83 multi-country proposals submitted, 25.3% were approved by the Technical Review Panel (TRP for funding, compared to 44.9% of single-country applications. The majority of approved multi-country applications were for HIV (76.2%, followed by malaria (19.0%, then tuberculosis (4.8%. TRP recommendations resulted in improvements to application forms, although guidance was generally vague. The in-depth review of Round 10

Survival of weed seeds and animal parasites as affected by anaerobic digestion at meso- and thermophilic conditions

DEFF Research Database (Denmark)

Johansen, Anders; Bangsø Nielsen, Henrik; Hansen, Christian M.

2013-01-01

did not affect egg survival during the first 48h and it took up to 10days before total elimination was reached. In general, anaerobic digestion in biogas plants seems an efficient way (thermophilic more efficient than mesophilic) to treat organic farm wastes in a way that suppresses animal parasites......, Ascaris suum, was assessed under conditions similar to biogas plants managed at meso- (37°C) and thermophilic (55°C) conditions. Cattle manure was used as digestion substrate and experimental units were sampled destructively over time. Regarding weed seeds, the effect of thermophilic conditions (55°C...

Progressive disseminated histoplasmosis presenting with cachexia and hypercalcemia

Directory of Open Access Journals (Sweden)

Khasawneh FA

2013-02-01

Full Text Available Faisal A Khasawneh,1 Subhan Ahmed,2 Ruba A Halloush31Section of Infectious Diseases, Department of Internal Medicine, Texas Tech University Health Sciences Center, Amarillo, TX, 2Section of Nephrology, Department of Internal Medicine, University of Oklahoma, Tulsa, OK, 3Amarillo Pathology Group, Amarillo, TX, USAAbstract: Histoplasmosis is a common endemic mycosis. The majority of infections involving this dimorphic fungus are asymptomatic. Manifestations in symptomatic patients are diverse, ranging from flu-like illness to a more serious disseminated disease. We present here a case of chronic disseminated histoplasmosis mimicking a metastatic cancer. We reviewed the literature for cases of disseminated histoplasmosis presenting with hypercalcemia, focusing particularly on clinical presentation, risk factors predisposing for fungal infection, and outcome. We report a case of a 65-year-old diabetic male who presented with unexplained weight loss and hypercalcemia. Multiple brain space-occupying lesions and bilateral adrenal enlargement were evident on imaging studies. Biopsies showed caseating granulomas with budding yeast, consistent with histoplasmosis. The patient's symptoms resolved after liposomal amphotericin B and itraconazole therapy. Granulomatous diseases, including fungal infections, should be considered alongside malignancies, in patients with similar presentation.Keywords: disseminated histoplasmosis, hypercalcemia

Host age modulates within-host parasite competition.

Science.gov (United States)

Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

2015-05-01

In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

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.

THE EVOLUTION OF PARASITES FROM THEIR HOSTS: A CASE STUDY IN THE PARASITIC RED ALGAE.

Science.gov (United States)

Goff, Lynda J; Ashen, Jon; Moon, Debra

1997-08-01

Morphological similarities of many parasites and their hosts have led to speculation that some groups of plant, animal, fungal, and algal parasites may have evolved directly from their hosts. These parasites, which have been termed adelphoparasites in the botanical literature, and more recently, agastoparasites in the insect literature, may evolve monophyletically from one host and radiate secondarily to other hosts or, these parasites may arise polyphyletically, each arising from its own host. In this study we compare the internal transcribed spacer regions of the nuclear ribosomal repeats of species and formae specialis (host races) included in the red algal parasite genus Asterocolax with its hosts, which all belong to the Phycodrys group of the Delesseriaceae and with closely related nonhost taxa of the Delesseriaceae. These analyses reveal that species of Asterocolax have evolved polyphyletically. Asterocolax erythroglossi from the North Atlantic host Erythroglossum laciniatum appears to have evolved from its host, whereas taxa included in the north Pacific species Asterocolax gardneri have had two independent origins. Asterocolax gardneri from the host Polyneura latissima probably arose directly from this host. In contrast, all other A. gardneri formae specialis appear to have originated from either Phycodrys setchellii or P. isabelliae and radiated secondarily onto other closely related taxa of the Phycodrys group, including Nienburgia andersoniana and Anisocladella pacifica. Gamete crossing experiments confirm that A. gardneri from each host is genetically isolated from both its host, and from other A. gardneri and their hosts. Cross-infection experiments reveal that A. gardneri develops normally only on its natural host, although some abberrant growth may occur on alternate hosts. The ability of red algal parasites to radiate secondarily to other red algal taxa, where they may become isolated genetically and speciate, suggests that this process of

A life cycle database for parasitic acanthocephalans, cestodes, and nematodes

Science.gov (United States)

Benesh, Daniel P.; Lafferty, Kevin D.; Kuris, Armand

2017-01-01

Parasitologists have worked out many complex life cycles over the last ~150 years, yet there have been few efforts to synthesize this information to facilitate comparisons among taxa. Most existing host-parasite databases focus on particular host taxa, do not distinguish final from intermediate hosts, and lack parasite life-history information. We summarized the known life cycles of trophically transmitted parasitic acanthocephalans, cestodes, and nematodes. For 973 parasite species, we gathered information from the literature on the hosts infected at each stage of the parasite life cycle (8510 host-parasite species associations), what parasite stage is in each host, and whether parasites need to infect certain hosts to complete the life cycle. We also collected life-history data for these parasites at each life cycle stage, including 2313 development time measurements and 7660 body size measurements. The result is the most comprehensive data summary available for these parasite taxa. In addition to identifying gaps in our knowledge of parasite life cycles, these data can be used to test hypotheses about life cycle evolution, host specificity, parasite life-history strategies, and the roles of parasites in food webs.

Overview on the effects of parasites on fish health

Science.gov (United States)

Iwanowicz, D.D.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

It is believed by many that parasites are only as important as the fish they infect. Parasites are ubiquitous, primarily surviving in a dynamic equilibrium with their host(s) and they are often overlooked in fish health assessments. Changes in the environment, both anthropogenic and environmental, can alter the parasite/host equilibrium and cause disease or mortality in fish. Therefore it is imperative that we have knowledge of both parasites and parasitic communities within a given population. When fish kills occur, it can often be associated with changes in parasite density and community composition. Often the damage associated with these fish is relative to the rate of infestation with the parasite; a fish that is lightly infected will show few signs of the parasite, while a heavily infected fish may become physiologically impaired and even die. Parasites can cause mechanical damage (fusion of gill lamellae, tissue replacement), physiological damage (cell proliferation, immunomodulation, detrimental behavioral responses, altered growth) and reproductive damage. As parasitism is the most common lifestyle on the planet, understanding its role in the environment may help researchers understand changes in a given fish population or stream ecosystem.

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

Coccidian intestinal parasites in the Priapulidae (Priapulida).

Science.gov (United States)

Saldarriaga, J F; Storch, V

1997-01-01

Four relatively uncommon members of the family Priapulidae (Priapulida) from very different parts of the world were examined to determine the presence of a parasitic coccidian in their midgut. The parasite was found in three of those priapulid species, Priapulopsis bicaudatus, P. australis, and Halicryptus higginsi, but not in the fourth one, Priapulus tuberculatospinosus. Using electron-microscopy techniques, we compared parasites of the different species with one another and with a parasite of Priapulus caudatus investigated by McLean in 1984. All of these parasites apparently belong to the same species and are likely to be Alveocystis intestinalis, a coccidian first described by Beltenev from P. caudatus and H. spinulosus. The present work greatly expands the geographical range of Alveocystis intestinalis and documents an uncommon case of low host specificity in eimeriid coccidians.

Exploitation Strategies in Social Parasites of Fungus Growing Ants

DEFF Research Database (Denmark)

Clement, Janni Dolby

One of the most remarkable and complex parasitic interactions is social parasitism, where a parasite exploits a complete society, rather than an individual organism. By integrating into a society the parasite gains protection against predators and diseases, and can redirect resources from the host...... to increase its own fitness. The host will use a sophisticated recognition system in order to accept nestmates and expel intruders from their societies. However this defence barrier can be overcome by parasites. Among the most specialized social parasites are the inquilines that exploit social insect colonies...... to this are Acromyrmex insinuator and Acromyrmex ameliae, parasites of fungus-growing ants. By still producing a worker caste both species offers a rare opportunity to study adaptive features in parasite worker behaviour. Furthermore can closely related inquiline-host combinations give us an insight in the trade...

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.

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.)

A high temperature reactor could be used to eliminate the Russian military plutonium

International Nuclear Information System (INIS)

Foucher, N.

1999-01-01

The GT-MHR reactor (Gas Turbine Modular Helium Reactor) aims the double objective to eliminate the Russian plutonium coming from weapons, ( until 3 tons by year) and to produce a competitive energy from a small-scale power reactor with a nuclear fuel that can be of different type (plutonium or uranium). This reactor has several advantages: a high yield (47%) as every high temperature reactor and to be used in combined cycle, a high level of safety because of its ability to evacuate the residual power in a totally passive way and because of the nature of its fuel that is made of ceramics with a very high melting point that is to say no possibility of core melt. The fission products are contained in the ceramics so that reactor cannot disseminate radioactivity in its structure and consequently does not induce irradiation for the personnel. (N.C.)

Dynamic analysis of a parasite population model

Science.gov (United States)

Sibona, G. J.; Condat, C. A.

2002-03-01

We study the dynamics of a model that describes the competitive interaction between an invading species (a parasite) and its antibodies in an living being. This model was recently used to examine the dynamical competition between Tripanosoma cruzi and its antibodies during the acute phase of Chagas' disease. Depending on the antibody properties, the model yields three types of outcomes, corresponding, respectively, to healing, chronic disease, and host death. Here, we study the dynamics of the parasite-antibody interaction with the help of simulations, obtaining phase trajectories and phase diagrams for the system. We show that, under certain conditions, the size of the parasite inoculation can be crucial for the infection outcome and that a retardation in the stimulated production of an antibody species may result in the parasite gaining a definitive advantage. We also find a criterion for the relative sizes of the parameters that are required if parasite-generated decoys are indeed to help the invasion. Decoys may also induce a qualitatively different outcome: a limit cycle for the antibody-parasite population phase trajectories.

Report on dissemination, monitoring and research into policy repository

DEFF Research Database (Denmark)

Chereches, Razvan; Rus, Diana; Aro, Arja R.

This report covers the dissemination activities of the project REPOPA months 2 to 60 (November 2011 to September 2016). This is the second major report of the dissemination work package (WP6) submitted to the European Commission (EC), which was aimed to provide the detailed results for disseminat...

Diagnostic problems with parasitic and non-parasitic splenic cysts

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Adas Gokhan

2009-05-01

Full Text Available Abstract Background The splenic cysts constitute a very rare clinical entity. They may occur secondary to trauma or even being more seldom due to parasitic infestations, mainly caused by ecchinocccus granulosus. Literature lacks a defined concencus including the treatment plans and follow up strategies, nor long term results of the patients. In the current study, we aimed to evaluate the diagnosis, management of patients with parasitic and non-parasitic splenic cysts together with their long term follow up progresses. Methods Twenty-four patients with splenic cysts have undergone surgery in our department over the last 9 years. Data from eighteen of the twenty-four patients were collected prospectively, while data from six were retrospectively collected. All patients were assessed in terms of age, gender, hospital stay, preoperative diagnosis, additional disease, serology, ultrasonography, computed tomography (CT, cyst recurrences and treatment. Results In this study, the majority of patients presented with abdominal discomfort and palpable swelling in the left hypochondrium. All patients were operated on electively. The patients included 14 female and 10 male patients, with a mean age of 44.77 years (range 20–62. Splenic hydatid cysts were present in 16 patients, one of whom also had liver hydatid cysts (6.25%. Four other patients were operated on for a simple cyst (16% two patients for an epithelial cyst, and the last two for splenic lymphangioma. Of the 16 patients diagnosed as having splenic hydatit cysts, 11 (68.7% were correctly diagnosed. Only two of these patients were administered benzimidazole therapy pre-operatively because of the risk of multicystic disease The mean follow-up period was 64 months (6–108. There were no recurrences of splenic cysts. Conclusion Surgeons should keep in mind the possibility of a parasitic cyst when no definitive alternative diagnosis can be made. In the treatment of splenic hydatidosis, benzimidazole

Failure of imidocarb dipropionate to eliminate Hepatozoon canis in naturally infected dogs based on parasitological and molecular evaluation methods.

Science.gov (United States)

Sasanelli, Mariateresa; Paradies, Paola; Greco, Beatrice; Eyal, Osnat; Zaza, Valeria; Baneth, Gad

2010-08-04

The efficacy of imidocarb dipropionate for the treatment of Hepatozoon canis infection was studied in three naturally infected asymptomatic dogs followed longitudinally over 8 months. Response to treatment was followed by monitoring blood counts, parasitemia levels in blood, parasite in concentrated buffy-coat smears and by PCR. The dogs were initially treated with a low dose of 3 mg/kg imidocarb dipropionate twice a month and when parasitemia persisted after five treatments, with the regular dose of 6 mg/kg. In one dog, H. canis gamonts were no longer detectable by blood and buffy-coat microscopy after 2 months of therapy with 6 mg/kg while in the two other dogs gamonts were intermittently found in blood but persistently detectable in buffy-coat smears during the whole study period. Furthermore, combined therapy with doxycycline monohydrate administered at 10 mg/kg/day PO for 4 weeks also failed to eliminate H. canis. PCR revealed that parasite DNA was present in the blood of all dogs at all sampling dates regardless of treatment refuting the effectiveness of treatment suggested by negative blood microscopy. Detection of H. canis in buffy coat was found to be twice as sensitive than by blood smear and detection by PCR was even more sensitive revealing infection in eight samples (16% of total samples) negative by blood and buffy-coat microscopy. In conclusion, imidocarb dipropionate was not effective in eliminating H. canis from dogs treated repeatedly over 8 months. Microscopical detection is not sufficient for the evaluation of treatment response in H. canis infection and follow up by molecular techniques is recommended. Copyright 2010 Elsevier B.V. All rights reserved.

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.

Effects of shortened host life span on the evolution of parasite life history and virulence in a microbial host-parasite system

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Koella Jacob C

2009-03-01

Full Text Available Abstract Background Ecological factors play an important role in the evolution of parasite exploitation strategies. A common prediction is that, as shorter host life span reduces future opportunities of transmission, parasites compensate with an evolutionary shift towards earlier transmission. They may grow more rapidly within the host, have a shorter latency time and, consequently, be more virulent. Thus, increased extrinsic (i.e., not caused by the parasite host mortality leads to the evolution of more virulent parasites. To test these predictions, we performed a serial transfer experiment, using the protozoan Paramecium caudatum and its bacterial parasite Holospora undulata. We simulated variation in host life span by killing hosts after 11 (early killing or 14 (late killing days post inoculation; after killing, parasite transmission stages were collected and used for a new infection cycle. Results After 13 cycles (≈ 300 generations, parasites from the early-killing treatment were less infectious, but had shorter latency time and higher virulence than those from the late-killing treatment. Overall, shorter latency time was associated with higher parasite loads and thus presumably with more rapid within-host replication. Conclusion The analysis of the means of the two treatments is thus consistent with theory, and suggests that evolution is constrained by trade-offs between virulence, transmission and within-host growth. In contrast, we found little evidence for such trade-offs across parasite selection lines within treatments; thus, to some extent, these traits may evolve independently. This study illustrates how environmental variation (experienced by the host can lead to the evolution of distinct parasite strategies.

Change of strategy is required for malaria elimination: a case study in Purworejo District, Central Java Province, Indonesia.

Science.gov (United States)

Murhandarwati, E Elsa Herdiana; Fuad, Anis; Sulistyawati; Wijayanti, Mahardika Agus; Bia, Michael Badi; Widartono, Barandi Sapta; Kuswantoro; Lobo, Neil F; Supargiyono; Hawley, William A

2015-08-16

Malaria has been targeted for elimination from Indonesia by 2030, with varying timelines for specific geographical areas based on disease endemicity. The regional deadline for malaria elimination for Java island, given the steady decrease of malaria cases, was the end of 2015. Purworejo District, a malaria-endemic area in Java with an annual parasite incidence (API) of 0.05 per 1,000 population in 2009, aims to enter this elimination stage. This study documents factors that affect incidence and spatial distribution of malaria in Purworejo, such as geomorphology, topography, health system issues, and identifies potential constraints and challenges to achieve the elimination stage, such as inter-districts coordination, decentralization policy and allocation of financial resources for the programme. Historical malaria data from 2007 to 2011 were collected through secondary data, in-depth interviews and focus group discussions during study year (2010-2011). Malaria cases were mapped using the village-centroid shape file to visualize its distribution with geomorphologic characteristics overlay and spatial distribution of malaria. API in each village in Purworejo and its surrounding districts from 2007 to 2011 was stratified into high, middle or low case incidence to show the spatiotemporal mapping pattern. The spatiotemporal pattern of malaria cases in Purworejo and the adjacent districts demonstrate repeated concentrated occurrences of malaria in specific areas from 2007 to 2011. District health system issues, i.e., suboptimal coordination between primary care and referral systems, suboptimal inter-district collaboration for malaria surveillance, decentralization policy and the lack of resources, especially district budget allocations for the malaria programme, were major constraints for programme sustainability. A new malaria elimination approach that fits the local disease transmission, intervention and political system is required. These changes include timely

[Can acute disseminated encephalomyelitis progress in a deferred way?].

Science.gov (United States)

Gener, B; Garaizar-Axpe, C; Ruiz Espinosa, C; Prats-Viñas, J M

To report on the heterogeneity with regard to the clinical course of the acute disseminated encephalomyelitis (ADEM). A 5 year old boy suffered of acute disseminated encephalomyelitis of unknown origin. This child suffered two episodes of different neurologic symptoms separated by several weeks. Based on the clinical manifestations and typical appearance of magnetic resonance imaging findings and the absence of oligoclonal bands in CSF immunoglobulins, multiple sclerosis (MS) was ruled out. We postulate that the recurrent symptoms in our patient could be explained as a multiphasic disseminated encephalomyelitis (MDEM). Favourable outcome after simultaneous treatment with methylprednisolone and intravenous immunoglobulin is emphasized in this report.

Elimination of Taenia solium Transmission in Northern Peru.

Science.gov (United States)

Garcia, Hector H; Gonzalez, Armando E; Tsang, Victor C W; O'Neal, Seth E; Llanos-Zavalaga, Fernando; Gonzalvez, Guillermo; Romero, Jaime; Rodriguez, Silvia; Moyano, Luz M; Ayvar, Viterbo; Diaz, Andre; Hightower, Allen; Craig, Philip S; Lightowlers, Marshall W; Gauci, Charles G; Leontsini, Elli; Gilman, Robert H

2016-06-16

Taeniasis and cysticercosis are major causes of seizures and epilepsy. Infection by the causative parasite Taenia solium requires transmission between humans and pigs. The disease is considered to be eradicable, but data on attempts at regional elimination are lacking. We conducted a three-phase control program in Tumbes, Peru, to determine whether regional elimination would be feasible. We systematically tested and compared elimination strategies to show the feasibility of interrupting the transmission of T. solium infection in a region of highly endemic disease in Peru. In phase 1, we assessed the effectiveness and feasibility of six intervention strategies that involved screening of humans and pigs, antiparasitic treatment, prevention education, and pig replacement in 42 villages. In phase 2, we compared mass treatment with mass screening (each either with or without vaccination of pigs) in 17 villages. In phase 3, we implemented the final strategy of mass treatment of humans along with the mass treatment and vaccination of pigs in the entire rural region of Tumbes (107 villages comprising 81,170 people and 55,638 pigs). The effect of the intervention was measured after phases 2 and 3 with the use of detailed necropsy to detect pigs with live, nondegenerated cysts capable of causing new infection. The necropsy sampling was weighted in that we preferentially included more samples from seropositive pigs than from seronegative pigs. Only two of the strategies implemented in phase 1 resulted in limited control over the transmission of T. solium infection, which highlighted the need to intensify the subsequent strategies. After the strategies in phase 2 were implemented, no cyst that was capable of further transmission of T. solium infection was found among 658 sampled pigs. One year later, without further intervention, 7 of 310 sampled pigs had live, nondegenerated cysts, but no infected pig was found in 11 of 17 villages, including all the villages in which mass

Disseminated histoplasmosis in a Danish patient with AIDS

DEFF Research Database (Denmark)

Smith, E; Franzmann, M; Mathiesen, Lars Reinhardt

1989-01-01

We present the first case of disseminated histoplasmosis in an AIDS patient in Europe, a 33-year-old Danish homosexual man, and recommend a detailed travel history in HIV-positive patients presenting with fever, weight loss and organomegaly. In Scandinavia disseminated histoplasmosis is rare...... but should be kept in mind as the disease is a major opportunistic infection in patients with AIDS. Treatment with amphotericin B followed by fluconazole was effective....

A strategic model for PV dissemination in Thailand

Energy Technology Data Exchange (ETDEWEB)

Hiranvarodom, S. [Rajamangala Inst. of Technology, Dept. of Electrical Engineering, Pathumthani (Thailand); Hill, R. [University of Northumbria, Newcastle Photovoltaics Applications Centre, Newcastle upon Tyne (United Kingdom); O' Keefe, P. [University of Northumbria, Dept. of Geography and Environmental Management, Newcastle upon Tyne (United Kingdom)

1999-07-01

The process of information dissemination is necessary for the successful implementation for photovoltaic (PV) programmes in developing countries, and it is essential to consider the strategies for implementation of a PV project to ensure that it will be successful. This paper proposes a strategic model for PV dissemination in Thailand and discusses the roles of key players in the implementation of the strategy and the responsibilities of these organisations. (Author)

The evolution of cuckoo parasitism: a comparative analysis.

Science.gov (United States)

Krüger, O; Davies, N B

2002-02-22

Cuckoos (family Cuculidae) show the highest diversity of breeding strategies within one bird family (parental care, facultative and obligate brood parasites). We used independent contrasts from two phylogenies to examine how this variation was related to 13 ecological and life-history variables. The ancestral state was probably tropical, resident, forest cuckoos with parental care. The evolution of brood parasitism was correlated with a shift to more open habitats, a change in diet, increases in species breeding-range size and migration, and a decrease in egg size. Once parasitism had evolved, more elaborate parasitic strategies (more harmful to host fitness) were correlated with decreased egg size, a change in diet, increased breeding-range size and migration, a shortened breeding season and a decrease in local abundance. Establishing the most probable evolutionary pathways, using the method of Pagel, shows that changes in ecological variables (such as migration, range size and diet type) preceded the evolution of brood parasitism, which is likely to be a later adaptation to reduce the cost of reproduction. By contrast, brood parasitism evolved before changes in egg size occurred, indicating that egg size is an adaptive trait in host--parasite coevolution. Our results suggest that the evolution of cuckoo brood parasitism reflects selection from both ecological pressures and host defences.

Richness patterns in the parasite communities of exotic poeciliid fishes.

Science.gov (United States)

Dove, A D

2000-06-01

Three species of poeciliids (Gambusia holbrooki, Xiphophorus helleri and X. maculatus) and 15 species of ecologically similar native freshwater fishes (mainly eleotrids, ambassids, melanotaeniids and retropinnids) were examined for parasite richness to investigate parasite flux, qualitative differences, quantitative differences and the structuring factors in parasite communities in the 2 fish types in Queensland, Australia. Theory suggests that poeciliids would harbour depauperate parasite communities. Results supported this hypothesis; poeciliids harboured more species-poor parasite infracommunities and regional faunas than natives (P analysis of presence/absence data for poeciliids and the 6 most-sampled native fishes revealed that parasite communities of the 2 fish groups are qualitatively distinct; the proportion of parasite species with complex life-cycles was lower in poeciliids than in native species, and Myxosporea, Microspora, Coccidia and parasitic Crustacea were all absent from poeciliids. Limited exchange of parasite species has occurred between natives and poeciliids. Logistic ordinal regression analysis revealed that fish origin (exotic or native), environmental disturbance and host sex were all significant determinants of parasite community richness (P competitive advantage over native fishes because of their lack of parasites.

Haemosporidian parasite infections in grouse and ptarmigan: Prevalence and genetic diversity of blood parasites in resident Alaskan birds

Science.gov (United States)

Smith, Matthew M.; Van Hemert, Caroline R.; Merizon, Richard

2016-01-01

Projections related to future climate warming indicate the potential for an increase in the distribution and prevalence of blood parasites in northern regions. However, baseline data are lacking for resident avian host species in Alaska. Grouse and ptarmigan occupy a diverse range of habitat types throughout the northern hemisphere and are among the most well-known and important native game birds in North America. Information regarding the prevalence and diversity of haemosporidian parasites in tetraonid species is limited, with few recent studies and an almost complete lack of genetic data. To better understand the genetic diversity of haemosporidian parasites in Alaskan tetraonids and to determine current patterns of geographic range and host specificity, we used molecular methods to screen 459 tissue samples collected from grouse and ptarmigan species across multiple regions of Alaska for infection by Leucocytozoon, Haemoproteus, and Plasmodium blood parasites. Infections were detected in 342 individuals, with overall apparent prevalence of 53% for Leucocytozoon, 21% for Haemoproteus, and 9% for Plasmodium. Parasite prevalence varied by region, with different patterns observed between species groups (grouse versus ptarmigan). Leucocytozoon was more common in ptarmigan, whereas Haemoproteus was more common in grouse. We detected Plasmodium infections in grouse only. Analysis of haemosporidian mitochondrial DNA cytochrome b sequences revealed 23 unique parasite haplotypes, several of which were identical to lineages previously detected in other avian hosts. Phylogenetic analysis showed close relationships between haplotypes from our study and those identified in Alaskan waterfowl for Haemoproteus and Plasmodium parasites. In contrast, Leucocytozoon lineages were structured strongly by host family. Our results provide some of the first genetic data for haemosporidians in grouse and ptarmigan species, and provide an initial baseline on the prevalence and diversity

Non-specific immunization against parasites

International Nuclear Information System (INIS)

Cox, F.E.G.

1981-01-01

Non-specific resistance to tumours can be induced by pretreating animals with micro-organisms, microbial extracts or various synthetic substances. Mycobacterium bovis, Corynebacterium parvum and a number of other micro-organisms also protect mice against rodent piroplasms and there is evidence that they are also protective against other parasites including Schistosoma mansoni. The actual mechanisms of non-specific immunity are still unclear but it is influenced by both the genetic make-up of the host and the nature of the parasite. Non-specific immunization may be a possible alternative to specific immunization and may avoid many of the potential immunopathological changes induced during parasite infections. Irradiated vaccines (Dictyocaulus viviparus, schistomiasis) are mentioned marginally only

New Laboulbeniales parasitic on endogean ground beetles.

Science.gov (United States)

Rossi, Walter; Santamaria, Sergi

2008-01-01

Three new species of Laboulbenia occurring on endogean Carabidae are described. These are L. lucifuga, parasitic on Winklerites spp. from Greece, L. magrinii, parasitic on Typloreicheia spp. from Italy, Reicheia spp. from Italy and Corsica and L. vailatii, parasitic on Coecoparvus spp. from Greece. New characters of L. coiffatii and L. endogea are pointed out, and the genus Scalenomyces is synonymized with Laboulbenia.

Information, Vol. 1, Number 4. Teacher Corps Dissemination Project Bulletin.

Science.gov (United States)

Rosenau, Fred S., Ed.

Guidelines are provided for disseminating information on teacher corps projects. Information is given on experienced disseminators such as existing networks that are available to help in planning. Suggestions are made on targeting information and marketing. (JD)

Imaging findings of disseminated pulmonary tuberculosis in patients with acquired immunodeficiency syndrome

International Nuclear Information System (INIS)

Song Wenyan; Zhao Zuqi; Zhao Dawei; Jia Cuiyu; Zhang Ruichi; Liu JinXin; Guan Wanhua; Liang Yi

2013-01-01

Objective: To study the imaging findings of disseminated pulmonary tuberculosis in patients with acquired immunodeficiency syndrome (AIDS). Methods: X-ray and multi-slice CT (MSCT) data from 33 AIDS patients with disseminated pulmonary tuberculosis confirmed by clinical manifestations and laboratory tests were analyzed retrospectively. Results: Thirty patients underwent initial chest radiography examination, 29 patients showed abnormal appearances, including bilateral disseminations in 21 patients and unilateral multiple disseminations in 8 patients. All patients underwent MSCT examination, 26 patients showed bilateral disseminations and 7 patients showed unilateral multiple disseminations. The abnormal pulmonary appearances included nodule (n = 25), miliary nodule (n = 22), air-space consolidation (n = 22), cavity (n = 11), fibrosis (n = 7), ground-glass opacity (n = 7), pneumatocele (n = 4), calcification (n = 2). There were 20 patients with more than 3 abnormal appearances and 13 patients with one or two abnormal appearances. The extra-pulmonary tuberculosis included pleural effusion (n = 33), lymphadenopathy (n = 30), intestinal tuberculosis (n = 3), splenic tuberculosis (n = 1) and cerebral tuberculosis (n = 1). Conclusion: Disseminated pulmonary tuberculosis should be highly suspected in AIDS patients with diffused nodules, miliary nodules, air-space consolidations or multiple cavities, accompanied with pleural effusion and lymphadenopathy. (authors)

Can Parasites Really Reveal Environmental Impact?

Science.gov (United States)

This review assesses the usefulness of parasites as bioindicators of environmental impact. Relevant studies published in the past decade were compiled; factorial meta-analysis demonstrated significant effects and interactions between parasite levels and the presence and concentra...

Repetitive elements in parasitic protozoa

Directory of Open Access Journals (Sweden)

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

Do Haphazard Reviews Provide Sound Directions for Dissemination Efforts?

Science.gov (United States)

Gambrill, Eileen; Littell, Julia H.

2010-01-01

Comments on The dissemination and implementation of evidence-based psychological treatments: A review of current efforts by Kathryn R. McHugh and David H. Barlow. The lead article in the February-March issue by McHugh and Barlow (2010) emphasized the need for "dissemination and implementation of evidence-based psychological treatments."…

Big bang in the evolution of extant malaria parasites.

Science.gov (United States)

Hayakawa, Toshiyuki; Culleton, Richard; Otani, Hiroto; Horii, Toshihiro; Tanabe, Kazuyuki

2008-10-01

Malaria parasites (genus Plasmodium) infect all classes of terrestrial vertebrates and display host specificity in their infections. It is therefore assumed that malaria parasites coevolved intimately with their hosts. Here, we propose a novel scenario of malaria parasite-host coevolution. A phylogenetic tree constructed using the malaria parasite mitochondrial genome reveals that the extant primate, rodent, bird, and reptile parasite lineages rapidly diverged from a common ancestor during an evolutionary short time period. This rapid diversification occurred long after the establishment of the primate, rodent, bird, and reptile host lineages, which implies that host-switch events contributed to the rapid diversification of extant malaria parasite lineages. Interestingly, the rapid diversification coincides with the radiation of the mammalian genera, suggesting that adaptive radiation to new mammalian hosts triggered the rapid diversification of extant malaria parasite lineages.

Host social behavior and parasitic infection: A multifactorial approach

Science.gov (United States)

Ezenwa, V.O.

2004-01-01

I examined associations between several components of host social organization, including group size and gregariousness, group stability, territoriality and social class, and gastrointestinal parasite load in African bovids. At an intraspecific level, group size was positively correlated with parasite prevalence, but only when the parasite was relatively host specific and only among host species living in stable groups. Social class was also an important predictor of infection rates. Among gazelles, territorial males had higher parasite intensities than did either bachelor males or females and juveniles, suggesting that highly territorial individuals may be either more exposed or more susceptible to parasites. Associations among territoriality, grouping, and parasitism were also found across taxa. Territorial host genera were more likely to be infected with strongyle nematodes than were nonterritorial hosts, and gregarious hosts were more infected than were solitary hosts. Analyses also revealed that gregariousness and territoriality had an interactive effect on individual parasite richness, whereby hosts with both traits harbored significantly more parasite groups than did hosts with only one or neither trait. Overall, study results indicate that multiple features of host social behavior influence infection risk and suggest that synergism between traits also has important effects on host parasite load.

Functional genomics approaches in parasitic helminths.

Science.gov (United States)

Hagen, J; Lee, E F; Fairlie, W D; Kalinna, B H

2012-01-01

As research on parasitic helminths is moving into the post-genomic era, an enormous effort is directed towards deciphering gene function and to achieve gene annotation. The sequences that are available in public databases undoubtedly hold information that can be utilized for new interventions and control but the exploitation of these resources has until recently remained difficult. Only now, with the emergence of methods to genetically manipulate and transform parasitic worms will it be possible to gain a comprehensive understanding of the molecular mechanisms involved in nutrition, metabolism, developmental switches/maturation and interaction with the host immune system. This review focuses on functional genomics approaches in parasitic helminths that are currently used, to highlight potential applications of these technologies in the areas of cell biology, systems biology and immunobiology of parasitic helminths. © 2011 Blackwell Publishing Ltd.

Identifying energy constraints to parasite resistance.

Science.gov (United States)

Allen, D E; Little, T J

2011-01-01

Life-history theory suggests that energetically expensive traits may trade off against each other, resulting in costs associated with the development or maintenance of a particular phenotype. The deployment of resistance mechanisms during parasite exposure is one such trait, and thus their potential benefit in fighting off parasites may be offset by costs to other fitness-related traits. In this study, we used trade-off theory as a basis to test whether stimulating an increased development rate in juvenile Daphnia would reveal energetic constraints to its ability to resist infection upon subsequent exposure to the castrating parasite, Pasteuria ramosa. We show that the presumably energetically expensive process of increased development rate does result in more infected hosts, suggesting that parasite resistance requires the allocation of resources from a limited source, and thus has the potential to be costly.

Parasitic myoma after supracervical laparoscopic histerectomy

Directory of Open Access Journals (Sweden)

Maurício Paulo Angelo Mieli

2013-06-01

Full Text Available Parasitic myoma is a condition defined as a myoma of extrauterine nourishing. It may occur spontaneously or as a consequence of surgical iatrogeny, after myomectomy or videolaparoscopic supracervical hysterectomy, due to remaining residues of uterine tissue fragments in the pelvic cavity after morcellation. The authors describe two cases in which the patients were submitted to videolaparoscopic supracervical hysterectomy and uterine body removal through morcellation. The sites of development of the parasitic myomas were next to the cervix stump in Case 1, and next to the right round ligament in Case 2. These parasitic myomas were removed by videolaparoscopy. After myomectomies or videolaparoscopic supracervical hysterectomies followed by uterine fragments removal from the pelvic cavity through morcellation, meticulous searching for residues or fragments of uterine tissue is mandatory to prevent the occurrence of parasitic myomas.

Cut Elimination, Identity Elimination, and Interpolation in Super-Belnap Logics

Czech Academy of Sciences Publication Activity Database

Přenosil, Adam

2017-01-01

Roč. 105, č. 6 (2017), s. 1255-1289 ISSN 0039-3215 R&D Projects: GA ČR GBP202/12/G061 EU Projects: European Commission(XE) 689176 - SYSMICS Institutional support: RVO:67985807 Keywords : Super-Belnap logic s * Dunn–Belnap logic * Logic of Paradox * Strong Kleene logic * Exactly True Logic * Gentzen calculus * Cut elimination * Identity elimination * Interpolation Subject RIV: BA - General Mathematics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 0.589, year: 2016

Parasites and poverty: the case of schistosomiasis.

Science.gov (United States)

King, Charles H

2010-02-01

Simultaneous and sequential transmission of multiple parasites, and their resultant overlapping chronic infections, are facts of life in many underdeveloped rural areas. These represent significant but often poorly measured health and economic burdens for affected populations. For example, the chronic inflammatory process associated with long-term schistosomiasis contributes to anaemia and undernutrition, which, in turn, can lead to growth stunting, poor school performance, poor work productivity, and continued poverty. To date, most national and international programs aimed at parasite control have not considered the varied economic and ecological factors underlying multi-parasite transmission, but some are beginning to provide a coordinated approach to control. In addition, interest is emerging in new studies for the re-evaluation and recalibration of the health burden of helminthic parasite infection. Their results should highlight the strong potential of integrated parasite control in efforts for poverty reduction. Copyright 2009 Elsevier B.V. All rights reserved.

Trypanosoma Infection Favors Brucella Elimination via IL-12/IFNγ-Dependent Pathways

Directory of Open Access Journals (Sweden)

Arnaud Machelart

2017-07-01

Full Text Available This study develops an original co-infection model in mice using Brucella melitensis, the most frequent cause of human brucellosis, and Trypanosoma brucei, the agent of African trypanosomiasis. Although the immunosuppressive effects of T. brucei in natural hosts and mice models are well established, we observed that the injection of T. brucei in mice chronically infected with B. melitensis induces a drastic reduction in the number of B. melitensis in the spleen, the main reservoir of the infection. Similar results are obtained with Brucella abortus- and Brucella suis-infected mice and B. melitensis-infected mice co-infected with Trypanosoma cruzi, demonstrating that this phenomenon is not due to antigenic cross-reactivity. Comparison of co-infected wild-type and genetically deficient mice showed that Brucella elimination required functional IL-12p35/IFNγ signaling pathways and the presence of CD4+ T cells. However, the impact of wild type and an attenuated mutant of T. brucei on B. melitensis were similar, suggesting that a chronic intense inflammatory reaction is not required to eliminate B. melitensis. Finally, we also tested the impact of T. brucei infection on the course of Mycobacterium tuberculosis infection. Although T. brucei strongly increases the frequency of IFNγ+CD4+ T cells, it does not ameliorate the control of M. tuberculosis infection, suggesting that it is not controlled by the same effector mechanisms as Brucella. Thus, whereas T. brucei infections are commonly viewed as immunosuppressive and pathogenic, our data suggest that these parasites can specifically affect the immune control of Brucella infection, with benefits for the host.

Disseminated cutaneous sporotrichosis in an immunocompetent individual.

Science.gov (United States)

Yap, Felix Boon-Bin

2011-10-01

Sporotrichosis is a subacute or chronic fungal infection caused by the ubiquitous fungus Sporothrix schenckii. Disseminated cutaneous sporotrichosis is an uncommon entity and is usually present in the immunosuppressed. Here, a case of disseminated cutaneous sporotrichosis in an immunocompetent patient is reported. This 70-year-old healthy woman presented with multiple painful ulcerated nodules on her face and upper and lower extremities of 6-month duration, associated with low-grade fever, night sweats, loss of appetite, and loss of weight. Histopathological examination of the skin biopsy revealed epidermal hyperplasia and granulomatous inflammation in the dermis, with budding yeast. Fungal culture identified S. schenckii. She had total resolution of the lesions after 2 weeks of intravenous amphotericin B and 8 months of oral itraconazole. All investigations for underlying immunosuppression and internal organ involvement were negative. This case reiterates that disseminated cutaneous sporotrichosis, although common in the immunosuppressed, can also be seen in immunocompetent patients. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Information dissemination analysis of different media towards the application for disaster pre-warning.

Science.gov (United States)

Zhang, Nan; Huang, Hong; Su, Boni; Zhao, Jinlong; Zhang, Bo

2014-01-01

Knowing the information dissemination mechanisms of different media and having an efficient information dissemination plan for disaster pre-warning plays a very important role in reducing losses and ensuring the safety of human beings. In this paper we established models of information dissemination for six typical information media, including short message service (SMS), microblogs, news portals, cell phones, television, and oral communication. Then, the information dissemination capability of each medium concerning individuals of different ages, genders, and residential areas was simulated, and the dissemination characteristics were studied. Finally, radar graphs were used to illustrate comprehensive assessments of the six media; these graphs show directly the information dissemination characteristics of all media. The models and the results are essential for improving the efficiency of information dissemination for the purpose of disaster pre-warning and for formulating emergency plans which help to reduce the possibility of injuries, deaths and other losses in a disaster.

Will Climate Change Affect Parasite- Host Relationship? | Okolo ...

African Journals Online (AJOL)

Research examining the causal relationships between climate, climate change and parasite ecology is the focus of increased attention. Understanding how parasites are likely to be affected by climate change requires an examination of the interactions between climate and parasite ecology and transmission.

Elimination device for metal impurities

International Nuclear Information System (INIS)

Yanagisawa, Ko.

1982-01-01

Purpose: To enable reuse of adsorbing materials by eliminating Fe 3 O 4 films reduced with adsorbing performance by way of electrolytic polishing and then forming fresh membranes using high temperature steams. Constitution: An elimination device is provided to a coolant clean-up system of a reactor for eliminating impurities such as cobalt. The elimination device comprises adsorbing materials made of stainless steel tips or the likes having Fe 3 O 4 films. The adsorbing materials are regenerated by applying an electric current between grid-like cathode plates and anode plates to leach out the Fe 3 O 4 films, washing out the electrolytic solution by cleaning water and then applying steams at high temperature onto the adsorbing materials to thereby form fresh Fe 3 O 4 films again thereon. The regeneration of the adsorbing materials enables to eliminate Co 60 and the like in the primary coolant efficiently. (Moriyama, K.)

Disseminated histoplasmosis in a Danish patient with AIDS

DEFF Research Database (Denmark)

Smith, E; Franzmann, M; Mathiesen, Lars Reinhardt

1989-01-01

We present the first case of disseminated histoplasmosis in an AIDS patient in Europe, a 33-year-old Danish homosexual man, and recommend a detailed travel history in HIV-positive patients presenting with fever, weight loss and organomegaly. In Scandinavia disseminated histoplasmosis is rare but ...... but should be kept in mind as the disease is a major opportunistic infection in patients with AIDS. Treatment with amphotericin B followed by fluconazole was effective....

[Research progress on cathepsin F of parasitic helminths].

Science.gov (United States)

Qu, Zi-Gang; Fu, Bao-Quan

2013-10-01

Cathepsin F is an important member of papain-like subfamily in cysteine protease family. Cathepsin F of helminth parasites can hydrolyze the specific substrate, degrade host protein such as hemoglobin for nutrition, and be involved in invasion into host tissue. Therefore, cathepsin F serves as a potential target for parasitic disease immunodiagnosis, vaccine design and anti-parasite drug screening. This article reviews the structural characteristics and mechanisms of cathepsin F, and research advances on cathepsin F of parasitic helminths.

Are all red algal parasites cut from the same cloth?

Directory of Open Access Journals (Sweden)

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.

Host age modulates parasite infectivity, virulence and reproduction.

Science.gov (United States)

Izhar, Rony; Ben-Ami, Frida

2015-07-01

Host age is one of the most striking differences among hosts within most populations, but there is very little data on how age-dependent effects impact ecological and evolutionary dynamics of both the host and the parasite. Here, we examined the influence of host age (juveniles, young and old adults) at parasite exposure on host susceptibility, fecundity and survival as well as parasite transmission, using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa. Younger D. magna were more susceptible to infection than older ones, regardless of host or parasite clone. Also, younger-infected D. magna became castrated faster than older hosts, but host and parasite clone effects contributed to this trait as well. Furthermore, the early-infected D. magna produced considerably more parasite transmission stages than late-infected ones, while host age at exposure did not affect virulence as it is defined in models (host mortality). When virulence is defined more broadly as the negative effects of infection on host fitness, by integrating the parasitic effects on host fecundity and mortality, then host age at exposure seems to slide along a negative relationship between host and parasite fitness. Thus, the virulence-transmission trade-off differs strongly among age classes, which in turn affects predictions of optimal virulence. Age-dependent effects on host susceptibility, virulence and parasite transmission could pose an important challenge for experimental and theoretical studies of infectious disease dynamics and disease ecology. Our results present a call for a more explicit stage-structured theory for disease, which will incorporate age-dependent epidemiological parameters. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Exploring the host parasitism of the migratory plant-parasitic nematode Ditylenchus destuctor by expressed sequence tags analysis.

Directory of Open Access Journals (Sweden)

Huan Peng

Full Text Available The potato rot nematode, Ditylenchus destructor, is a very destructive nematode pest on many agriculturally important crops worldwide, but the molecular characterization of its parasitism of plant has been limited. The effectors involved in nematode parasitism of plant for several sedentary endo-parasitic nematodes such as Heterodera glycines, Globodera rostochiensis and Meloidogyne incognita have been identified and extensively studied over the past two decades. Ditylenchus destructor, as a migratory plant parasitic nematode, has different feeding behavior, life cycle and host response. Comparing the transcriptome and parasitome among different types of plant-parasitic nematodes is the way to understand more fully the parasitic mechanism of plant nematodes. We undertook the approach of sequencing expressed sequence tags (ESTs derived from a mixed stage cDNA library of D. destructor. This is the first study of D. destructor ESTs. A total of 9800 ESTs were grouped into 5008 clusters including 3606 singletons and 1402 multi-member contigs, representing a catalog of D. destructor genes. Implementing a bioinformatics' workflow, we found 1391 clusters have no match in the available gene database; 31 clusters only have similarities to genes identified from D. africanus, the most closely related species to D. destructor; 1991 clusters were annotated using Gene Ontology (GO; 1550 clusters were assigned enzyme commission (EC numbers; and 1211 clusters were mapped to 181 KEGG biochemical pathways. 22 ESTs had similarities to reported nematode effectors. Interestedly, most of the effectors identified in this study are involved in host cell wall degradation or modification, such as 1,4-beta-glucanse, 1,3-beta-glucanse, pectate lyase, chitinases and expansin, or host defense suppression such as calreticulin, annexin and venom allergen-like protein. This result implies that the migratory plant-parasitic nematode D. destructor secrets similar effectors to

Parasitic Contamination of Raw Vegetables in Shahroud, Semnan

Directory of Open Access Journals (Sweden)

Saeid Nazemi

2012-08-01

Full Text Available Background: Given the importance of healthy vegetables, the present study was conducted to determine parasitic infection of vegetable consumed in Shahroud.Materials and Methods: This cross-sectional study has been conducted on 92 samples of various vegetables collected from 16 vegetable growing farms and 1 vegetable process workshop. Results: Sixty two percent of tested vegetables lacked parasites and the highest amount of parasites observed (34.78% was related to Giardia lamblia. A significant relationship was observed between parasite and having toilets in the farms as well as the extent of farms.Conclusion: safety of fertilizers consumed by farms and healthy fruits can have an effective role in reducing the parasitic infections.

Polyamine uptake by the intraerythrocytic malaria parasite, Plasmodium falciparum.

Science.gov (United States)

Niemand, J; Louw, A I; Birkholtz, L; Kirk, K

2012-09-01

Polyamines and the enzymes involved in their biosynthesis are present at high levels in rapidly proliferating cells, including cancer cells and protozoan parasites. Inhibition of polyamine biosynthesis in asexual blood-stage malaria parasites causes cytostatic arrest of parasite development under in vitro conditions, but does not cure infections in vivo. This may be due to replenishment of the parasite's intracellular polyamine pool via salvage of exogenous polyamines from the host. However, the mechanism(s) of polyamine uptake by the intraerythrocytic parasite are not well understood. In this study, the uptake of the polyamines, putrescine and spermidine, into Plasmodium falciparum parasites functionally isolated from their host erythrocyte was investigated using radioisotope flux techniques. Both putrescine and spermidine were taken up into isolated parasites via a temperature-dependent process that showed cross-competition between different polyamines. There was also some inhibition of polyamine uptake by basic amino acids. Inhibition of polyamine biosynthesis led to an increase in the total amount of putrescine and spermidine taken up from the extracellular medium. The uptake of putrescine and spermidine by isolated parasites was independent of extracellular Na(+) but increased with increasing external pH. Uptake also showed a marked dependence on the parasite's membrane potential, decreasing with membrane depolarization and increasing with membrane hyperpolarization. The data are consistent with polyamines being taken up into the parasite via an electrogenic uptake process, energised by the parasite's inwardly negative membrane potential. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Homage to Linnaeus: How many parasites? How many hosts?

Science.gov (United States)

Dobson, Andy; Lafferty, Kevin D.; Kuris, Armand M.; Hechinger, Ryan F.; Jetz, Walter

2008-01-01

Estimates of the total number of species that inhabit the Earth have increased significantly since Linnaeus's initial catalog of 20,000 species. The best recent estimates suggest that there are ≈6 million species. More emphasis has been placed on counts of free-living species than on parasitic species. We rectify this by quantifying the numbers and proportion of parasitic species. We estimate that there are between 75,000 and 300,000 helminth species parasitizing the vertebrates. We have no credible way of estimating how many parasitic protozoa, fungi, bacteria, and viruses exist. We estimate that between 3% and 5% of parasitic helminths are threatened with extinction in the next 50 to 100 years. Because patterns of parasite diversity do not clearly map onto patterns of host diversity, we can make very little prediction about geographical patterns of threat to parasites. If the threats reflect those experienced by avian hosts, then we expect climate change to be a major threat to the relatively small proportion of parasite diversity that lives in the polar and temperate regions, whereas habitat destruction will be the major threat to tropical parasite diversity. Recent studies of food webs suggest that ≈75% of the links in food webs involve a parasitic species; these links are vital for regulation of host abundance and potentially for reducing the impact of toxic pollutants. This implies that parasite extinctions may have unforeseen costs that impact the health and abundance of a large number of free-living species.

Information Dissemination Analysis of Different Media towards the Application for Disaster Pre-Warning

OpenAIRE

Zhang, Nan; Huang, Hong; Su, Boni; Zhao, Jinlong; Zhang, Bo

2014-01-01

Knowing the information dissemination mechanisms of different media and having an efficient information dissemination plan for disaster pre-warning plays a very important role in reducing losses and ensuring the safety of human beings. In this paper we established models of information dissemination for six typical information media, including short message service (SMS), microblogs, news portals, cell phones, television, and oral communication. Then, the information dissemination capability ...

Does moving up a food chain increase aggregation in parasites?

Science.gov (United States)

Lester, R J G; McVinish, R

2016-05-01

General laws in ecological parasitology are scarce. Here, we evaluate data on numbers of fish parasites published by over 200 authors to determine whether acquiring parasites via prey is associated with an increase in parasite aggregation. Parasite species were grouped taxonomically to produce 20 or more data points per group as far as possible. Most parasites that remained at one trophic level were less aggregated than those that had passed up a food chain. We use a stochastic model to show that high parasite aggregation in predators can be solely the result of the accumulation of parasites in their prey. The model is further developed to show that a change in the predators feeding behaviour with age may further increase parasite aggregation. © 2016 The Author(s).

Blood parasites in reptiles imported to Germany.

Science.gov (United States)

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.

Where are the parasites in food webs?

Science.gov (United States)

2012-01-01

This review explores some of the reasons why food webs seem to contain relatively few parasite species when compared to the full diversity of free living species in the system. At present, there are few coherent food web theories to guide scientific studies on parasites, and this review posits that the methods, directions and questions in the field of food web ecology are not always congruent with parasitological inquiry. For example, topological analysis (the primary tool in food web studies) focuses on only one of six important steps in trematode life cycles, each of which requires a stable community dynamic to evolve. In addition, these transmission strategies may also utilize pathways within the food web that are not considered in traditional food web investigations. It is asserted that more effort must be focused on parasite-centric models, and a central theme is that many different approaches will be required. One promising approach is the old energetic perspective, which considers energy as the critical resource for all organisms, and the currency of all food web interactions. From the parasitological point of view, energy can be used to characterize the roles of parasites at all levels in the food web, from individuals to populations to community. The literature on parasite energetics in food webs is very sparse, but the evidence suggests that parasite species richness is low in food webs because parasites are limited by the quantity of energy available to their unique lifestyles. PMID:23092160

Where are the parasites in food webs?

Directory of Open Access Journals (Sweden)

Sukhdeo Michael VK

2012-10-01

Full Text Available Abstract This review explores some of the reasons why food webs seem to contain relatively few parasite species when compared to the full diversity of free living species in the system. At present, there are few coherent food web theories to guide scientific studies on parasites, and this review posits that the methods, directions and questions in the field of food web ecology are not always congruent with parasitological inquiry. For example, topological analysis (the primary tool in food web studies focuses on only one of six important steps in trematode life cycles, each of which requires a stable community dynamic to evolve. In addition, these transmission strategies may also utilize pathways within the food web that are not considered in traditional food web investigations. It is asserted that more effort must be focused on parasite-centric models, and a central theme is that many different approaches will be required. One promising approach is the old energetic perspective, which considers energy as the critical resource for all organisms, and the currency of all food web interactions. From the parasitological point of view, energy can be used to characterize the roles of parasites at all levels in the food web, from individuals to populations to community. The literature on parasite energetics in food webs is very sparse, but the evidence suggests that parasite species richness is low in food webs because parasites are limited by the quantity of energy available to their unique lifestyles.

Breastfeeding and risk of parasitic infection-a review

Directory of Open Access Journals (Sweden)

Prameela Kannan Kutty

2014-11-01

Full Text Available Breastfeeding, as exclusive nutrition in the first six months of life, is a necessary nutritional requisite in infants. Except for very few maternal diseases that contraindicate breastfeeding, some of which still controversial, breastfeeding mothers must continue exclusive and sustained lactation to provide maximum overall benefits through breastfeeding. Parasitic infections is a global disease and children remain a significant proportion of the affected population. The complex and mandatory life cycles of some parasites, particularly the helminths may partly explain their geographical distribution. The world-wide prevalence of parasitic infections as well as the largely asymptomatic nature of most infections, make many of these infections to likely remain under-recognized. Breast milk, the prime infant nutrition must be recognized to be more than a rare vehicle of parasite transmission, but also a general and focused immune defensive tool against some important parasites. The possibility and influence of small quantities of parasite antigens in breast milk have not been adequately explored. It is believed that useful immunological responses both direct and indirect in breast milk that occur due to the presence of parasite antigens, must be further studied in the light of both immediate and long term benefits. Within this context, and prompted by a spectrum of existing uncertainties, researched and hypothetical roles of parasites and associated immunological responses in the lactating mammary gland are proposed and reviewed.

Converting hard copy documents for electronic dissemination

Energy Technology Data Exchange (ETDEWEB)

Hoffman, F.

1994-12-31

Since the advent of computer systems, the goal of a paperless office, and even a paperless society, has been pursued. While the normal paper flow in an organization is far from totally automated, particularly for items requiring signatures or authorizations, electronic information dissemination is becoming an almost simple task. The reasons for providing on-line documents are many and include faster and easier access for everyone, elimination of printing costs, reduction of wasted shelf and desk space, and the security of having a centrally-located, always up-to-date document. New computer software even provides the user with the ability to annotate documents and to have bookmarks so that the old scribbled-in and dog-eared manual can be replaced without loosing this `customizability`. Moreover, new hypermedia capabilities mean that documents can be read in a non-linear fashion and can include color figures and photographs, audio, and even animation sequences, capabilities which exceed those of paper. The proliferation of network-based information servers, coupled with the growth of the Internet, has enticed academic, governmental, and even commercial organizations to provide increasing numbers of documents and data bases in electronic form via the network, not just to internal staff, but to the public as well. Much of this information, which includes everything from mundane company procedures to spiffy marketing brochures, was previously published only in hard copy. Converting existing documents to electronic form and producing only electronic versions of new documents poses some interesting challenges to the maintainer or author.

Gastrointestinal parasites of feral cats from Christmas Island.

Science.gov (United States)

Adams, P J; Elliot, A D; Algar, D; Brazell, R I

2008-01-01

To investigate the gastrointestinal parasites present in feral cats on Christmas Island, with particular interest in the protozoan parasite Toxoplasma gondii. Faecal and serum samples were collected from 28 and 25 cats respectively that were trapped as part of an ongoing eradication program being run on Christmas Island by the Department of Environment and Conservation. Faecal samples were screened microscopically for helminth and protozoan parasites. Serum samples were screened for antibodies to T gondii using a commercial indirect immunofluorescence assay (IFA) and a latex agglutination test (LAT). The most common helminth parasites detected were Toxocara cati (present in 15 of 28 faecal samples), Strongyloides sp (13/28), Aelurostrongylus abstrusus, (7/28), an unidentified capillarid (6/28) and Ancylostoma sp (4/28). Based on serology, T gondii was the most common parasite detected (protozoan or otherwise) with antibodies detected in 24 serum samples by IFA and 23 serum samples by LAT. Cats on Christmas Island harbour many of the helminth and protozoan parasites reported from feral cats elsewhere in Australia. The high seroprevalence of T gondii in these cats indicates a high level of exposure to the parasite in this environment.

Disseminated cysticercosis: clinical spectrum, Toll-like receptor-4 gene polymorphisms and role of albendazole: A prospective follow-up of 60 cases with a review of 56 published cases.

Science.gov (United States)

Qavi, Abdul; Garg, Ravindra Kumar; Malhotra, Hardeep Singh; Jain, Amita; Kumar, Neeraj; Malhotra, Kiran Preet; Srivastava, Pradeep Kumar; Verma, Rajesh; Sharma, Praveen Kumar

2016-09-01

. Of the 4 deaths recorded, 3 had a heavy parasitic load and died after praziquantel therapy.Toll-like receptor-4 gene polymorphisms are associated with an increased susceptibility to disseminated cysticercosis, in the Indian population. Albendazole treatment seems to reduce the lesion load and improve symptoms.

Disseminated cutaneous sporotrichosis in patient with alcoholism.

Science.gov (United States)

Benvegnú, Ana Maria; Stramari, Juliana; Dallazem, Lia Natália Diehl; Chemello, Raíssa Massaia Londero; Beber, André Avelino Costa

2017-01-01

Sporotrichosis is the most prevalent subcutaneous mycosis and is characterized by a subacute or chronic development of a cutaneous or subcutaneous nodular lesion. It is caused by the dimorphic fungus Sporothrix spp, which may manifest in different clinical forms. The disseminated cutaneous form is uncommon and is more likely to occur in immunocompromised patients. We report a 47-year-old male patient with multiple cutaneous and subcutaneous nodules. The patient was diagnosed with disseminated cutaneous sporotrichosis based on the isolation and identification of Sporothrix spp. The patient was treated with potassium iodide, which resulted in clinical improvement of the lesions.

A description of parasites from Iranian snakes.

Science.gov (United States)

Nasiri, Vahid; Mobedi, Iraj; Dalimi, Abdolhossein; Mirakabadi, Abbas Zare; Ghaffarifar, Fatemeh; Teymurzadeh, Shohreh; Karimi, Gholamreza; Abdoli, Amir; Paykari, Habibollah

2014-12-01

Little is known of the parasitic fauna of terrestrial snakes in Iran. This study aimed to evaluate the parasitic infection rates of snakes in Iran. A total of 87 snakes belonging to eight different species, that were collected between May 2012 and September 2012 and died after the hold in captivity, under which they were kept for taking poisons, were examined for the presence of gastrointestinal and blood parasites. According to our study 12 different genera of endoparasites in 64 (73.56%) of 87 examined snakes were determined. Forty one snakes (47.12%) had gastrointestinal parasites. In prepared blood smears, it was found that in 23 (26.43%) of 87 examined snakes there are at least one hemoparasite. To our knowledge, these are the first data on the internal parasitic fauna of Iranian terrestrial snakes and our findings show a higher prevalence of these organisms among them. Copyright © 2014 Elsevier Inc. All rights reserved.

De Novo Assembly and Characterization of the Transcriptome of the Parasitic Weed Dodder Identifies Genes Associated with Plant Parasitism1[C][W][OPEN

Science.gov (United States)

Ranjan, Aashish; Ichihashi, Yasunori; Farhi, Moran; Zumstein, Kristina; Townsley, Brad; David-Schwartz, Rakefet; Sinha, Neelima R.

2014-01-01

Parasitic flowering plants are one of the most destructive agricultural pests and have major impact on crop yields throughout the world. Being dependent on finding a host plant for growth, parasitic plants penetrate their host using specialized organs called haustoria. Haustoria establish vascular connections with the host, which enable the parasite to steal nutrients and water. The underlying molecular and developmental basis of parasitism by plants is largely unknown. In order to investigate the process of parasitism, RNAs from different stages (i.e. seed, seedling, vegetative strand, prehaustoria, haustoria, and flower) were used to de novo assemble and annotate the transcriptome of the obligate plant stem parasite dodder (Cuscuta pentagona). The assembled transcriptome was used to dissect transcriptional dynamics during dodder development and parasitism and identified key gene categories involved in the process of plant parasitism. Host plant infection is accompanied by increased expression of parasite genes underlying transport and transporter categories, response to stress and stimuli, as well as genes encoding enzymes involved in cell wall modifications. By contrast, expression of photosynthetic genes is decreased in the dodder infective stages compared with normal stem. In addition, genes relating to biosynthesis, transport, and response of phytohormones, such as auxin, gibberellins, and strigolactone, were differentially expressed in the dodder infective stages compared with stems and seedlings. This analysis sheds light on the transcriptional changes that accompany plant parasitism and will aid in identifying potential gene targets for use in controlling the infestation of crops by parasitic weeds. PMID:24399359

Host partitioning by parasites in an intertidal crustacean community.

Science.gov (United States)

Koehler, Anson V; Poulin, Robert

2010-10-01

Patterns of host use by parasites throughout a guild community of intermediate hosts can depend on several biological and ecological factors, including physiology, morphology, immunology, and behavior. We looked at parasite transmission in the intertidal crustacean community of Lower Portobello Bay, Dunedin, New Zealand, with the intent of: (1) mapping the flow of parasites throughout the major crustacean species, (2) identifying hosts that play the most important transmission role for each parasite, and (3) assessing the impact of parasitism on host populations. The most prevalent parasites found in 14 species of crustaceans (635 specimens) examined were the trematodes Maritrema novaezealandensis and Microphallus sp., the acanthocephalans Profilicollis spp., the nematode Ascarophis sp., and an acuariid nematode. Decapods were compatible hosts for M. novaezealandensis, while other crustaceans demonstrated lower host suitability as shown by high levels of melanized and immature parasite stages. Carapace thickness, gill morphology, and breathing style may contribute to the differential infection success of M. novaezealandensis and Microphallus sp. in the decapod species. Parasite-induced host mortality appears likely with M. novaezealandensis in the crabs Austrohelice crassa, Halicarcinus varius, Hemigrapsus sexdentatus, and Macrophthalmus hirtipes, and also with Microphallus sp. in A. crassa. Overall, the different parasite species make different use of available crustacean intermediate hosts and possibly contribute to intertidal community structure.

The unusual lipid binding proteins of parasitic helminths and their potential roles in parasitism and as therapeutic targets.

Science.gov (United States)

Franchini, Gisela R; Pórfido, Jorge L; Ibáñez Shimabukuro, Marina; Rey Burusco, María F; Bélgamo, Julián A; Smith, Brian O; Kennedy, Malcolm W; Córsico, Betina

2015-02-01

In this review paper we aim at presenting the current knowledge on structural aspects of soluble lipid binding proteins (LBPs) found in parasitic helminths and to discuss their potential role as novel drug targets. Helminth parasites produce and secrete a great variety of LBPs that may participate in the acquisition of nutrients from their host, such as fatty acids and cholesterol. It is also postulated that LBPs might interfere in the regulation of the host׳s immune response by sequestering lipidic intermediates or delivering bioactive lipids. A detailed comprehension of the structure of these proteins, as well as their interactions with ligands and membranes, is important to understand host-parasite relationships that they may mediate. This information could also contribute to determining the role that these proteins may play in the biology of parasitic helminths and how they modulate the immune systems of their hosts, and also towards the development of new therapeutics and prevention of the diseases caused by these highly pathogenic parasites. Copyright © 2014 Elsevier Ltd. All rights reserved.

Documenting and disseminating agricultural indigenous knowledge ...

African Journals Online (AJOL)

Documenting and disseminating agricultural indigenous knowledge for sustainable food security in Uganda. ... University of Dar es Salaam Library Journal ... Moreover, small-scale farmers should be involved in agricultural extension services ...

Disseminated intravascular and intracardiac thrombosis after cardiopulmonary bypass

Directory of Open Access Journals (Sweden)

Deepak K Tempe

2017-01-01

Full Text Available Massive intracardiac and intravascular thrombosis is a rare complication following cardiopulmonary bypass (CPB. Most of the cases of the disseminated thrombosis have been reported in patients undergoing complex cardiac surgeries and those receiving antifibrinolytic agents during CPB. We report the occurrence of disseminated intravascular and intracardiac thrombosis after CPB in a patient undergoing mitral valve replacement in which no antifibrinolytic agent was used. The possible pathophysiology and management of the patient is discussed.

48 CFR 3052.235-70 - Dissemination of information-educational institutions.

Science.gov (United States)

2010-10-01

...: Dissemination of Information—Educational Institutions (DEC 2003) (a) The Department of Homeland Security (DHS... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Dissemination of information-educational institutions. 3052.235-70 Section 3052.235-70 Federal Acquisition Regulations System...

Molecular and Cellular Mechanisms of Shigella flexneri Dissemination.

Science.gov (United States)

Agaisse, Hervé

2016-01-01

The intracellular pathogen Shigella flexneri is the causative agent of bacillary dysentery in humans. The disease is characterized by bacterial invasion of intestinal cells, dissemination within the colonic epithelium through direct spread from cell to cell, and massive inflammation of the intestinal mucosa. Here, we review the mechanisms supporting S. flexneri dissemination. The dissemination process primarily relies on actin assembly at the bacterial pole, which propels the pathogen throughout the cytosol of primary infected cells. Polar actin assembly is supported by polar expression of the bacterial autotransporter family member IcsA, which recruits the N-WASP/ARP2/3 actin assembly machinery. As motile bacteria encounter cell-cell contacts, they form plasma membrane protrusions that project into adjacent cells. In addition to the ARP2/3-dependent actin assembly machinery, protrusion formation relies on formins and myosins. The resolution of protrusions into vacuoles occurs through the collapse of the protrusion neck, leading to the formation of an intermediate membrane-bound compartment termed vacuole-like protrusions (VLPs). VLP formation requires tyrosine kinase and phosphoinositide signaling in protrusions, which relies on the integrity of the bacterial type 3 secretion system (T3SS). The T3SS is also required for escaping double membrane vacuoles through the activity of the T3SS translocases IpaB and IpaC, and the effector proteins VirA and IcsB. Numerous factors supporting envelope biogenesis contribute to IcsA exposure and maintenance at the bacterial pole, including LPS synthesis, membrane proteases, and periplasmic chaperones. Although less characterized, the assembly and function of the T3SS in the context of bacterial dissemination also relies on factors supporting envelope biogenesis. Finally, the dissemination process requires the adaptation of the pathogen to various cellular compartments through transcriptional and post-transcriptional mechanisms.

Peritoneal dissemination complicating morcellation of uterine mesenchymal neoplasms.

Directory of Open Access Journals (Sweden)

Michael A Seidman

Full Text Available BACKGROUND: Power morcellation has become a common technique for the minimally invasive resection of uterine leiomyomas. This technique is associated with dissemination of cellular material throughout the peritoneum. When morcellated uterine tumors are unexpectedly found to be leiomyosarcomas or tumors with atypical features (atypical leiomyoma, smooth muscle tumor of uncertain malignant potential, there may be significant clinical consequences. This study was undertaken to determine the frequency and clinical consequence of intraperitoneal dissemination of these neoplasms. METHODOLOGY/PRINCIPAL FINDINGS: From 2005-2010, 1091 instances of uterine morcellation were identified at BWH. Unexpected diagnoses of leiomyoma variants or atypical and malignant smooth muscle tumors occurred in 1.2% of cases using power morcellation for uterine masses clinically presumed to be "fibroids" over this period, including one endometrial stromal sarcoma (ESS, one cellular leiomyoma (CL, six atypical leiomyomas (AL, three smooth muscle tumor of uncertain malignant potential (STUMPs, and one leiomyosarcoma (LMS. The rate of unexpected sarcoma after the laparoscopic morcellation procedure was 0.09%, 9-fold higher than the rate currently quoted to patients during pre-procedure briefing, and this rate may increase over time as diagnostically challenging or under-sampled tumors manifest their biological potential. Furthermore, when examining follow-up laparoscopies, both from in-house and consultation cases, disseminated disease occurred in 64.3% of all tumors (zero of one ESS, one of one CL, zero of one AL, four of four STUMPs, and four of seven LMS. Only disseminated leiomyosarcoma, however, was associated with mortality. Procedures are proposed for pathologic evaluation of morcellation specimens and associated follow-up specimens. CONCLUSIONS/SIGNIFICANCE: While additional study is warranted, these data suggest uterine morcellation carries a risk of disseminating

Molecular and Cellular mechanisms of Shigella flexneri dissemination

Directory of Open Access Journals (Sweden)

Herve eAgaisse

2016-03-01

Full Text Available The intracellular pathogen Shigella flexneri is the causative agent of bacillary dysentery in humans. The disease is characterized by bacterial invasion of intestinal cells, dissemination within the colonic epithelium through direct spread from cell to cell, and massive inflammation of the intestinal mucosa. Here, we review the mechanisms supporting S. flexneri dissemination. The dissemination process primarily relies on actin assembly at the bacterial pole, which propels the pathogen throughout the cytosol of primary infected cells. Polar actin assembly is supported by polar expression of the bacterial autotransporter family member IcsA, which recruits the N-WASP/ARP2/3 actin assembly machinery. As motile bacteria encounter cell-cell contacts, they form plasma membrane protrusions that project into adjacent cells. In addition to the ARP2/3-dependent actin assembly machinery, protrusion formation relies on formins and myosins. The resolution of protrusions into vacuoles occurs through the collapse of the protrusion neck, leading to the formation of an intermediate membrane-bound compartment termed vacuole-like protrusions (VLPs. VLP formation requires tyrosine kinase and phosphoinositide signaling in protrusions, which relies on the integrity of the bacterial type 3 secretion system (T3SS. The T3SS is also required for escaping double membrane vacuoles through the activity of the T3SS translocases IpaB and IpaC, and the effector proteins VirA and IcsB. Numerous factors supporting envelope biogenesis contribute to IcsA exposure and maintenance at the bacterial pole, including LPS synthesis, membrane proteases, and periplasmic chaperones. Although less characterized, the assembly and function of the T3SS in the context of bacterial dissemination also relies on factors supporting envelope biogenesis. Finally, the dissemination process requires the adaptation of the pathogen to various cellular compartments through transcriptional and post

MULTIFOCAL CHOROIDITIS IN DISSEMINATED SPOROTRICHOSIS IN PATIENTS WITH HIV/AIDS.

Science.gov (United States)

Biancardi, Ana L; Freitas, Dayvison F S; Valviesse, Vitor R G de A; Andrade, Hugo B; de Oliveira, Manoel M E; do Valle, Antonio C F; Zancope-Oliveira, Rosely M; Galhardo, Maria C G; Curi, Andre L L

2017-01-01

In this article, the authors describe multifocal choroiditis related to disseminated sporotrichosis in patients with HIV/AIDS. We conducted a retrospective observational study of three patients infected with HIV who presented with disseminated sporotrichosis characterized by cutaneous lesions, multifocal choroiditis, and other manifestations, including osteomyelitis and involvement of the bone marrow, larynx, pharynx, and nasal and oral mucosa. Five eyes of three patients with HIV/AIDS showed multifocal choroiditis related to disseminated sporotrichosis. The CD4 counts ranged from 25 to 53 mm. All patients were asymptomatic visually. The ocular disease was bilateral in two patients. The lesion size ranged from 1/3 to 2 disc diameters. None of the patients had vitritis. Of the 12 lesions, 9 were localized in the posterior pole (Zone 1) and 3 were localized in the mild periphery (Zone 2). Multifocal choroiditis due to disseminated sporotrichosis can occur in profoundly immunosuppressed patients with HIV/AIDS.

Prevalence of gastrointestinal parasites of rams brought into ...

African Journals Online (AJOL)

In an effort to gain a better understanding into the role played by food animals in the epidemiology of gastrointestinal parasites, we assessed the prevalence of gastrointestinal parasites in different breeds of rams brought into Abeokuta during a festive season by ... The only protozoan parasite identified was Eimeria spp.

Knowledge dissemination: a core mission

CERN Multimedia

2011-01-01

It’s been a year since the CERN Council approved our policy on intellectual property management, so I’d like to take a look at what we’ve achieved since then. In short, a great deal. We’ve moved away from a fairly unregulated approach towards a well balanced and clearly defined system built around sound intellectual property management designed to deliver maximum dissemination and benefit for society from CERN innovation. It’s a move that I celebrate and fully support.   In 2009, CERN signed two partnership agreements to develop CERN technologies, two commercial licenses and eleven R&D licenses. Last year, the figures were six partnership agreements, five commercial licenses and twenty R&D licenses, indicating a real increase in dissemination efforts. From 2009 to 2010, however, the number of new technologies that were identified and disclosed hardly changed: nine in 2009, ten in 2010. These numbers are good, but we must improve, particu...

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.

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

Site requirements and kinetics of immune-dependent elimination of intravascularly administered lung stage schistosomula in mice immunized with highly irradiated cercariae of Schistosoma mansoni

International Nuclear Information System (INIS)

Mangold, B.L.; Dean, D.A.; Coulson, P.S.; Wilson, R.A.

1986-01-01

Experiments were performed to compare the migration and survival of 75Se-labeled schistosomes, introduced by percutaneous cercarial exposure or by intravascular administration of 7-day-old lung stage schistosomula, in control and irradiated cercaria-immunized mice. Schistosomula were intravascularly introduced into the lungs, systemic organs and liver by injection via the femoral vein (FV), left ventricle (LV), and superior mesenteric vein (SMV), respectively. The fate of challenge larvae was examined by autoradiography of host tissues and by recovery of adult worms. It was found that both normal and immune elimination were site-dependent. In control mice 45%-60% of cercarial penetrants and lung schistosomula injected into the FV and LV were recoverable as adult worms, while a significantly greater number (70%-85%) were recoverable when lung schistosomula were injected into the SMV. In immunized mice, parasites introduced as either cercariae or FV-injected schistosomula were both highly sensitive to immune elimination. LV-injected schistosomula were also sensitive but to a slightly lesser degree. In contrast, schistosomula placed directly in the liver by SMV injection were totally insensitive to immune elimination. It was concluded that elimination of schistosomula in irradiated cercaria-immunized mice occurs in the lungs and/or in the systemic organs, but not in the liver. Also, it was concluded that immune elimination is not a rapid process, since more than 7 days were required after intravascular challenge for the development of demonstrable differences between control and immunized mice

Genotyping of Toxoplasma gondii: DNA extraction from formalin-fixed paraffin-embedded autopsy tissues from AIDS patients who died by severe disseminated toxoplasmosis.

Science.gov (United States)

Bastos da Silva, Inara; Batista, Tatiana Pimental de Andrade; Martines, Roosecelis Brasil; Kanamura, Cristina Takami; Ferreira, Isabelle Martins Ribeiro; Vidal, Jose Ernesto; Pereira-Chioccola, Vera Lucia

2016-06-01

This study investigated the genetic features of Toxoplasma gondii isolated directly in autopsies of HIV-infected patients who died with severe disseminated toxoplasmosis. This retrospective analysis was conducted in a cohort of 15 HIV-infected patients with clinical and laboratory data. They had previous cerebral toxoplasmosis at least 6 months before the disseminated toxoplasmosis episode. The hypothesis was that they were infected with highly virulent parasites due to the condition in which they died. T. gondii genotyping was done directly in DNA extracted from 30 autopsy brain and lung samples (2 per patient) and mutilocus PCR-RFLP genotyping was done using 12 molecular markers. The 30 clinical samples were genotyped successfully in 8 or more loci and six suggestive genotypes were identified. One of them was Toxo DB #11, previously identified in different domestic animals and virulent in experimental animals. The other five suggestive genotypes identified in 14 patients were not described. TgHuDis1 was the most frequent and was determined in 8 patients. TgHuDis3 and TgHuDis5 were identified in two patients each. TgHuDis2 and TgHuDis4 have been identified in one patient each. These suggestive genotypes could be considered as virulent, since they caused severe tissue damage and had similar characteristics as Toxo # DB 11. Copyright © 2016 Elsevier Inc. All rights reserved.

An Adaptive Directed Query Dissemination Scheme for Wireless Sensor Networks

NARCIS (Netherlands)

Chatterjea, Supriyo; De Luigi, Simone; Havinga, Paul J.M.; Sun, M.T.

This paper describes a directed query dissemination scheme, DirQ that routes queries to the appropriate source nodes based on both constant and dynamicvalued attributes such as sensor types and sensor values. Unlike certain other query dissemination schemes, location information is not essential for

28 CFR 42.405 - Public dissemination of title VI information.

Science.gov (United States)

2010-07-01

... Federally Assisted Programs § 42.405 Public dissemination of title VI information. (a) Federal agencies... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Public dissemination of title VI information. 42.405 Section 42.405 Judicial Administration DEPARTMENT OF JUSTICE NONDISCRIMINATION; EQUAL...

28 CFR 20.33 - Dissemination of criminal history record information.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Dissemination of criminal history record information. 20.33 Section 20.33 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS Federal Systems and Exchange of Criminal History Record Information § 20.33 Dissemination of...

Modelling strategies to break transmission of lymphatic filariasis--aggregation, adherence and vector competence greatly alter elimination.

Science.gov (United States)

Irvine, M A; Reimer, L J; Njenga, S M; Gunawardena, S; Kelly-Hope, L; Bockarie, M; Hollingsworth, T D

2015-10-22

With ambitious targets to eliminate lymphatic filariasis over the coming years, there is a need to identify optimal strategies to achieve them in areas with different baseline prevalence and stages of control. Modelling can assist in identifying what data should be collected and what strategies are best for which scenarios. We develop a new individual-based, stochastic mathematical model of the transmission of lymphatic filariasis. We validate the model by fitting to a first time point and predicting future timepoints from surveillance data in Kenya and Sri Lanka, which have different vectors and different stages of the control programme. We then simulate different treatment scenarios in low, medium and high transmission settings, comparing once yearly mass drug administration (MDA) with more frequent MDA and higher coverage. We investigate the potential impact that vector control, systematic non-compliance and different levels of aggregation have on the dynamics of transmission and control. In all settings, increasing coverage from 65 to 80 % has a similar impact on control to treating twice a year at 65 % coverage, for fewer drug treatments being distributed. Vector control has a large impact, even at moderate levels. The extent of aggregation of parasite loads amongst a small portion of the population, which has been estimated to be highly variable in different settings, can undermine the success of a programme, particularly if high risk sub-communities are not accessing interventions. Even moderate levels of vector control have a large impact both on the reduction in prevalence and the maintenance of gains made during MDA, even when parasite loads are highly aggregated, and use of vector control is at moderate levels. For the same prevalence, differences in aggregation and adherence can result in very different dynamics. The novel analysis of a small amount of surveillance data and resulting simulations highlight the need for more individual level data to be

One Health: parasites and beyond.

Science.gov (United States)

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

The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

Directory of Open Access Journals (Sweden)

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.

Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

Energy Technology Data Exchange (ETDEWEB)

Vermelho, Marli Batista Fernandes; Correia, Ademir Silva; Michailowsky, Tania Cibele de Almeida; Suzart, Elizete Kazumi Kuniyoshi; Ibanes, Aline Santos; Almeida, Lanamar Aparecida; Khoury, Zarifa; Barba, Mario Flores, E-mail: marlivermelho@globo.com [Instituto de Infectologia Emilio Ribas (IIER), Sao Paulo, SP (Brazil)

2015-03-15

Objective: to evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and methods: retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. (author)

17 CFR 242.602 - Dissemination of quotations in NMS securities.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Dissemination of quotations in... FUTURES Regulation Nms-Regulation of the National Market System § 242.602 Dissemination of quotations in... establish and maintain procedures and mechanisms for collecting bids, offers, quotation sizes, and aggregate...

Parasites as Biological Tags for Stock Discrimination of Beaked Redfish (Sebastes mentella: Parasite Infra-Communities vs. Limited Resolution of Cytochrome Markers.

Directory of Open Access Journals (Sweden)

Regina Klapper

Full Text Available The use of parasites as biological tags for discrimination of fish stocks has become a commonly used approach in fisheries management. Metazoan parasite community analysis and anisakid nematode population genetics based on a mitochondrial cytochrome marker were applied in order to assess the usefulness of the two parasitological methods for stock discrimination of beaked redfish Sebastes mentella of three fishing grounds in the North East Atlantic. Multivariate, model-based approaches demonstrated that the metazoan parasite fauna of beaked redfish from East Greenland differed from Tampen, northern North Sea, and Bear Island, Barents Sea. A joint model (latent variable model was used to estimate the effects of covariates on parasite species and identified four parasite species as main source of differences among fishing grounds; namely Chondracanthus nodosus, Anisakis simplex s.s., Hysterothylacium aduncum, and Bothriocephalus scorpii. Due to its high abundance and differences between fishing grounds, Anisakis simplex s.s. was considered as a major biological tag for host stock differentiation. Whilst the sole examination of Anisakis simplex s.s. on a population genetic level is only of limited use, anisakid nematodes (in particular, A. simplex s.s. can serve as biological tags on a parasite community level. This study confirmed the use of multivariate analyses as a tool to evaluate parasite infra-communities and to identify parasite species that might serve as biological tags. The present study suggests that S. mentella in the northern North Sea and Barents Sea is not sub-structured.

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F.

2018-02-26

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host’s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host’s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F

2017-12-07

Circadian rhythms enable organisms to synchronise the processes underpinning survival and reproduction to anticipate daily changes in the external environment. Recent work shows that daily (circadian) rhythms also enable parasites to maximise fitness in the context of ecological interactions with their hosts. Because parasite rhythms matter for their fitness, understanding how they are regulated could lead to innovative ways to reduce the severity and spread of diseases. Here, we examine how host circadian rhythms influence rhythms in the asexual replication of malaria parasites. Asexual replication is responsible for the severity of malaria and fuels transmission of the disease, yet, how parasite rhythms are driven remains a mystery. We perturbed feeding rhythms of hosts by 12 hours (i.e. diurnal feeding in nocturnal mice) to desynchronise the host\\'s peripheral oscillators from the central, light-entrained oscillator in the brain and their rhythmic outputs. We demonstrate that the rhythms of rodent malaria parasites in day-fed hosts become inverted relative to the rhythms of parasites in night-fed hosts. Our results reveal that the host\\'s peripheral rhythms (associated with the timing of feeding and metabolism), but not rhythms driven by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms resynchronise to the altered host feeding rhythms when food availability is shifted, which is not mediated through rhythms in the host immune system. Our observations suggest that parasites actively control their developmental rhythms. Finally, counter to expectation, the severity of disease symptoms expressed by hosts was not affected by desynchronisation of their central and peripheral rhythms. Our study at the intersection of disease ecology and chronobiology opens up a new

75 FR 75207 - Regulation SBSR-Reporting and Dissemination of Security-Based Swap Information

Science.gov (United States)

2010-12-02

... Dissemination of Security-Based Swap Information; Proposed Rule #0;#0;Federal Register / Vol. 75 , No. 231... Dissemination of Security-Based Swap Information AGENCY: Securities and Exchange Commission. ACTION: Proposed... SBSR--Reporting and Dissemination of Security-Based Swap Information (``Regulation SBSR'') under the...

Sexual reproduction and genetic exchange in parasitic protists.

Science.gov (United States)

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.

Extent, Awareness and Perception of Dissemination Bias in Qualitative Research: An Explorative Survey

Science.gov (United States)

Toews, Ingrid; Glenton, Claire; Lewin, Simon; Berg, Rigmor C.; Noyes, Jane; Booth, Andrew; Marusic, Ana; Malicki, Mario; Munthe-Kaas, Heather M.; Meerpohl, Joerg J.

2016-01-01

Background Qualitative research findings are increasingly used to inform decision-making. Research has indicated that not all quantitative research on the effects of interventions is disseminated or published. The extent to which qualitative researchers also systematically underreport or fail to publish certain types of research findings, and the impact this may have, has received little attention. Methods A survey was delivered online to gather data regarding non-dissemination and dissemination bias in qualitative research. We invited relevant stakeholders through our professional networks, authors of qualitative research identified through a systematic literature search, and further via snowball sampling. Results 1032 people took part in the survey of whom 859 participants identified as researchers, 133 as editors and 682 as peer reviewers. 68.1% of the researchers said that they had conducted at least one qualitative study that they had not published in a peer-reviewed journal. The main reasons for non-dissemination were that a publication was still intended (35.7%), resource constraints (35.4%), and that the authors gave up after the paper was rejected by one or more journals (32.5%). A majority of the editors and peer reviewers “(strongly) agreed” that the main reasons for rejecting a manuscript of a qualitative study were inadequate study quality (59.5%; 68.5%) and inadequate reporting quality (59.1%; 57.5%). Of 800 respondents, 83.1% “(strongly) agreed” that non-dissemination and possible resulting dissemination bias might undermine the willingness of funders to support qualitative research. 72.6% and 71.2%, respectively, “(strongly) agreed” that non-dissemination might lead to inappropriate health policy and health care. Conclusions The proportion of non-dissemination in qualitative research is substantial. Researchers, editors and peer reviewers play an important role in this. Non-dissemination and resulting dissemination bias may impact on

Extent, Awareness and Perception of Dissemination Bias in Qualitative Research: An Explorative Survey.

Science.gov (United States)

Toews, Ingrid; Glenton, Claire; Lewin, Simon; Berg, Rigmor C; Noyes, Jane; Booth, Andrew; Marusic, Ana; Malicki, Mario; Munthe-Kaas, Heather M; Meerpohl, Joerg J

2016-01-01

Qualitative research findings are increasingly used to inform decision-making. Research has indicated that not all quantitative research on the effects of interventions is disseminated or published. The extent to which qualitative researchers also systematically underreport or fail to publish certain types of research findings, and the impact this may have, has received little attention. A survey was delivered online to gather data regarding non-dissemination and dissemination bias in qualitative research. We invited relevant stakeholders through our professional networks, authors of qualitative research identified through a systematic literature search, and further via snowball sampling. 1032 people took part in the survey of whom 859 participants identified as researchers, 133 as editors and 682 as peer reviewers. 68.1% of the researchers said that they had conducted at least one qualitative study that they had not published in a peer-reviewed journal. The main reasons for non-dissemination were that a publication was still intended (35.7%), resource constraints (35.4%), and that the authors gave up after the paper was rejected by one or more journals (32.5%). A majority of the editors and peer reviewers "(strongly) agreed" that the main reasons for rejecting a manuscript of a qualitative study were inadequate study quality (59.5%; 68.5%) and inadequate reporting quality (59.1%; 57.5%). Of 800 respondents, 83.1% "(strongly) agreed" that non-dissemination and possible resulting dissemination bias might undermine the willingness of funders to support qualitative research. 72.6% and 71.2%, respectively, "(strongly) agreed" that non-dissemination might lead to inappropriate health policy and health care. The proportion of non-dissemination in qualitative research is substantial. Researchers, editors and peer reviewers play an important role in this. Non-dissemination and resulting dissemination bias may impact on health care research, practice and policy. More

Extent, Awareness and Perception of Dissemination Bias in Qualitative Research: An Explorative Survey.

Directory of Open Access Journals (Sweden)

Ingrid Toews

Full Text Available Qualitative research findings are increasingly used to inform decision-making. Research has indicated that not all quantitative research on the effects of interventions is disseminated or published. The extent to which qualitative researchers also systematically underreport or fail to publish certain types of research findings, and the impact this may have, has received little attention.A survey was delivered online to gather data regarding non-dissemination and dissemination bias in qualitative research. We invited relevant stakeholders through our professional networks, authors of qualitative research identified through a systematic literature search, and further via snowball sampling.1032 people took part in the survey of whom 859 participants identified as researchers, 133 as editors and 682 as peer reviewers. 68.1% of the researchers said that they had conducted at least one qualitative study that they had not published in a peer-reviewed journal. The main reasons for non-dissemination were that a publication was still intended (35.7%, resource constraints (35.4%, and that the authors gave up after the paper was rejected by one or more journals (32.5%. A majority of the editors and peer reviewers "(strongly agreed" that the main reasons for rejecting a manuscript of a qualitative study were inadequate study quality (59.5%; 68.5% and inadequate reporting quality (59.1%; 57.5%. Of 800 respondents, 83.1% "(strongly agreed" that non-dissemination and possible resulting dissemination bias might undermine the willingness of funders to support qualitative research. 72.6% and 71.2%, respectively, "(strongly agreed" that non-dissemination might lead to inappropriate health policy and health care.The proportion of non-dissemination in qualitative research is substantial. Researchers, editors and peer reviewers play an important role in this. Non-dissemination and resulting dissemination bias may impact on health care research, practice and policy

Empirical support for optimal virulence in a castrating parasite.

Directory of Open Access Journals (Sweden)

Knut Helge Jensen

2006-07-01

Full Text Available The trade-off hypothesis for the evolution of virulence predicts that parasite transmission stage production and host exploitation are balanced such that lifetime transmission success (LTS is maximised. However, the experimental evidence for this prediction is weak, mainly because LTS, which indicates parasite fitness, has been difficult to measure. For castrating parasites, this simple model has been modified to take into account that parasites convert host reproductive resources into transmission stages. Parasites that kill the host too early will hardly benefit from these resources, while postponing the killing of the host results in diminished returns. As predicted from optimality models, a parasite inducing castration should therefore castrate early, but show intermediate levels of virulence, where virulence is measured as time to host killing. We studied virulence in an experimental system where a bacterial parasite castrates its host and produces spores that are not released until after host death. This permits estimating the LTS of the parasite, which can then be related to its virulence. We exposed replicate individual Daphnia magna (Crustacea of one host clone to the same amount of bacterial spores and followed individuals until their death. We found that the parasite shows strong variation in the time to kill its host and that transmission stage production peaks at an intermediate level of virulence. A further experiment tested for the genetic basis of variation in virulence by comparing survival curves of daphniids infected with parasite spores obtained from early killing versus late killing infections. Hosts infected with early killer spores had a significantly higher death rate as compared to those infected with late killers, indicating that variation in time to death was at least in part caused by genetic differences among parasites. We speculate that the clear peak in lifetime reproductive success at intermediate killing times

Online dissemination of news in Nicolae Titulescu University

Directory of Open Access Journals (Sweden)

Stefan Ciucu

2013-01-01

Full Text Available Traditional” websites are a very good method of disseminating information for students in online environment. We might thing that with this new trend, people pref er to get information on a social network website, but actually for complex information the “traditional” websites are better. Facebook social network is very used in Romania, mostly by young people. It is a common saying around here: if you do not have a Facebook account, then you do not exist. The Facebook account of the University was created in may, 2012. Since then it has been a powerful tool for disseminating information, but mostly for photos, short messages, links and videos. YouTube and Twitter are not that used by students for finding information about their University, but during one year, I’ve recorded growth in number of followers. In this paper I compare these four online methods of disseminating information for students (may 2012 - may 2013 period of time.

Mammalian gastrointestinal parasites in rainforest remnants

Indian Academy of Sciences (India)

Here, we studied the gastrointestinal parasites of nonhuman mammalian hosts living in 10 rainforest patches of the Anamalai Tiger Reserve, India. We examined 349 faecal samples of 17 mammalian species and successfully identified 24 gastroin-testinal parasite taxa including 1 protozoan, 2 trematode, 3 cestode and 18 ...

Disseminated cutaneous sporotrichosis in patient with alcoholism

Directory of Open Access Journals (Sweden)

Ana Maria Benvegnú

Full Text Available Abstract Sporotrichosis is the most prevalent subcutaneous mycosis and is characterized by a subacute or chronic development of a cutaneous or subcutaneous nodular lesion. It is caused by the dimorphic fungus Sporothrix spp, which may manifest in different clinical forms. The disseminated cutaneous form is uncommon and is more likely to occur in immunocompromised patients. We report a 47-year-old male patient with multiple cutaneous and subcutaneous nodules. The patient was diagnosed with disseminated cutaneous sporotrichosis based on the isolation and identification of Sporothrix spp. The patient was treated with potassium iodide, which resulted in clinical improvement of the lesions.

Parasites of fish larvae: do they follow metabolic energetic laws?

Science.gov (United States)

Muñoz, Gabriela; Landaeta, Mauricio F; Palacios-Fuentes, Pamela; George-Nascimento, Mario

2015-11-01

Eumetazoan parasites in fish larvae normally exhibit large body sizes relative to their hosts. This observation raises a question about the potential effects that parasites might have on small fish. We indirectly evaluated this question using energetic metabolic laws based on body volume and the parasite densities. We compared the biovolume as well as the numeric and volumetric densities of parasites over the host body volume of larval and juvenile-adult fish and the average of these parasitological descriptors for castrator parasites and the parasites found in the fish studied here. We collected 5266 fish larvae using nearshore zooplankton sampling and 1556 juveniles and adult fish from intertidal rocky pools in central Chile. We considered only the parasitized hosts: 482 fish larvae and 629 juvenile-adult fish. We obtained 31 fish species; 14 species were in both plankton and intertidal zones. Fish larvae exhibited a significantly smaller biovolume but larger numeric and volumetric densities of parasites than juvenile-adult fish. Therefore, fish larvae showed a large proportion of parasite biovolume per unit of body host (cm(3)). However, the general scaling of parasitological descriptors and host body volume were similar between larvae and juvenile-adult fish. The ratio between the biovolume of parasites and the host body volume in fish larvae was similar to the proportion observed in castrator parasites. Furthermore, the ratios were different from those of juvenile-adult fish, which suggests that the presence of parasites implies a high energetic cost for fish larvae that would diminish the fitness of these small hosts.

Acute disseminated toxoplasmosis in a juvenile cheetah (Acinonyx jubatus).

Science.gov (United States)

Lloyd, Christopher; Stidworthy, Mark F

2007-09-01

A juvenile cheetah (Acinonyx jubatus) died with rapidly progressive pyrexia, tachypnea, abdominal effusion, and hepatomegaly. Postmortem examination revealed lesions consistent with acute disseminated infection with Toxoplasma gondii. The presence of this organism was confirmed in multiple organs by immunohistochemistry and polymerase chain reaction. To the best of our knowledge, we propose this to be the first reported case of primary acute disseminated toxoplasmosis in a cheetah.

Quinine-induced disseminated intravascular coagulation.

Science.gov (United States)

Spearing, R L; Hickton, C M; Sizeland, P; Hannah, A; Bailey, R R

Recurrent disseminated intravascular coagulation occurred in 3 women after ingestion of quinine tablets for cramp. All had circulating quinine-dependent antibodies to platelets and in 2 there was initial evidence of antibody consumption, with low titres that rose steeply over the next few days and remained high for many months.

Predicting lymphatic filariasis transmission and elimination dynamics using a multi-model ensemble framework

Directory of Open Access Journals (Sweden)

Morgan E. Smith

2017-03-01

Full Text Available Mathematical models of parasite transmission provide powerful tools for assessing the impacts of interventions. Owing to complexity and uncertainty, no single model may capture all features of transmission and elimination dynamics. Multi-model ensemble modelling offers a framework to help overcome biases of single models. We report on the development of a first multi-model ensemble of three lymphatic filariasis (LF models (EPIFIL, LYMFASIM, and TRANSFIL, and evaluate its predictive performance in comparison with that of the constituents using calibration and validation data from three case study sites, one each from the three major LF endemic regions: Africa, Southeast Asia and Papua New Guinea (PNG. We assessed the performance of the respective models for predicting the outcomes of annual MDA strategies for various baseline scenarios thought to exemplify the current endemic conditions in the three regions. The results show that the constructed multi-model ensemble outperformed the single models when evaluated across all sites. Single models that best fitted calibration data tended to do less well in simulating the out-of-sample, or validation, intervention data. Scenario modelling results demonstrate that the multi-model ensemble is able to compensate for variance between single models in order to produce more plausible predictions of intervention impacts. Our results highlight the value of an ensemble approach to modelling parasite control dynamics. However, its optimal use will require further methodological improvements as well as consideration of the organizational mechanisms required to ensure that modelling results and data are shared effectively between all stakeholders.

Modelling the elimination of river blindness using long-term epidemiological and programmatic data from Mali and Senegal

Directory of Open Access Journals (Sweden)

Martin Walker

2017-03-01

Full Text Available The onchocerciasis transmission models EPIONCHO and ONCHOSIM have been independently developed and used to explore the feasibility of eliminating onchocerciasis from Africa with mass (annual or biannual distribution of ivermectin within the timeframes proposed by the World Health Organization (WHO and endorsed by the 2012 London Declaration on Neglected Tropical Diseases (i.e. by 2020/2025. Based on the findings of our previous model comparison, we implemented technical refinements and tested the projections of EPIONCHO and ONCHOSIM against long-term epidemiological data from two West African transmission foci in Mali and Senegal where the observed prevalence of infection was brought to zero circa 2007–2009 after 15–17 years of mass ivermectin treatment. We simulated these interventions using programmatic information on the frequency and coverage of mass treatments and trained the model projections using longitudinal parasitological data from 27 communities, evaluating the projected outcome of elimination (local parasite extinction or resurgence. We found that EPIONCHO and ONCHOSIM captured adequately the epidemiological trends during mass treatment but that resurgence, while never predicted by ONCHOSIM, was predicted by EPIONCHO in some communities with the highest (inferred vector biting rates and associated pre-intervention endemicities. Resurgence can be extremely protracted such that low (microfilarial prevalence between 1% and 5% can be maintained for 3–5 years before manifesting more prominently. We highlight that post-treatment and post-elimination surveillance protocols must be implemented for long enough and with high enough sensitivity to detect possible residual latent infections potentially indicative of resurgence. We also discuss uncertainty and differences between EPIONCHO and ONCHOSIM projections, the potential importance of vector control in high-transmission settings as a complementary intervention strategy, and the

Further exploration of dissemination bias in qualitative research required to facilitate assessment within qualitative evidence syntheses.

Science.gov (United States)

Toews, Ingrid; Booth, Andrew; Berg, Rigmor C; Lewin, Simon; Glenton, Claire; Munthe-Kaas, Heather M; Noyes, Jane; Schroter, Sara; Meerpohl, Joerg J

2017-08-01

To conceptualise and discuss dissemination bias in qualitative research. It is likely that the mechanisms leading to dissemination bias in quantitative research, including time lag, language, gray literature, and truncation bias also contribute to dissemination bias in qualitative research. These conceptual considerations have informed the development of a research agenda. Further exploration of dissemination bias in qualitative research is needed, including the extent of non-dissemination and related dissemination bias, and how to assess dissemination bias within qualitative evidence syntheses. We also need to consider the mechanisms through which dissemination bias in qualitative research could occur to explore approaches for reducing it. Copyright © 2017 Elsevier Inc. All rights reserved.

Gastro-Intestinal Parasites of Warthogs (Phacochoerus Africanus ...

African Journals Online (AJOL)

Gastro-Intestinal Parasites of Warthogs (Phacochoerus Africanus) from the Nazinga Game Ranch of Burkina Faso. ... the prevalence of gastrointestinal parasites in warthogs from the Nazinga Game Ranch of ... AJOL African Journals Online.

Deep-sequencing to resolve complex diversity of apicomplexan parasites in platypuses and echidnas: Proof of principle for wildlife disease investigation.

Science.gov (United States)

Šlapeta, Jan; Saverimuttu, Stefan; Vogelnest, Larry; Sangster, Cheryl; Hulst, Frances; Rose, Karrie; Thompson, Paul; Whittington, Richard

2017-11-01

The short-beaked echidna (Tachyglossus aculeatus) and the platypus (Ornithorhynchus anatinus) are iconic egg-laying monotremes (Mammalia: Monotremata) from Australasia. The aim of this study was to demonstrate the utility of diversity profiles in disease investigations of monotremes. Using small subunit (18S) rDNA amplicon deep-sequencing we demonstrated the presence of apicomplexan parasites and confirmed by direct and cloned amplicon gene sequencing Theileria ornithorhynchi, Theileria tachyglossi, Eimeria echidnae and Cryptosporidium fayeri. Using a combination of samples from healthy and diseased animals, we show a close evolutionary relationship between species of coccidia (Eimeria) and piroplasms (Theileria) from the echidna and platypus. The presence of E. echidnae was demonstrated in faeces and tissues affected by disseminated coccidiosis. Moreover, the presence of E. echidnae DNA in the blood of echidnas was associated with atoxoplasma-like stages in white blood cells, suggesting Hepatozoon tachyglossi blood stages are disseminated E. echidnae stages. These next-generation DNA sequencing technologies are suited to material and organisms that have not been previously characterised and for which the material is scarce. The deep sequencing approach supports traditional diagnostic methods, including microscopy, clinical pathology and histopathology, to better define the status quo. This approach is particularly suitable for wildlife disease investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

Immunization with Live Attenuated Leishmania donovani Centrin−/− Parasites Is Efficacious in Asymptomatic Infection

Directory of Open Access Journals (Sweden)

Nevien Ismail

2017-12-01

Full Text Available Currently, there is no vaccine against visceral leishmaniasis (VL. Toward developing an effective vaccine, we have reported extensively on the immunogenicity of live attenuated LdCentrin−/− mutants in naive animal models. In VL endemic areas, asymptomatic carriers outnumber symptomatic cases of VL and are considered to be a reservoir of infection. Vaccination of asymptomatic cases represents a viable strategy to eliminate VL. Immunological correlates of protection thus derived might have limited applicability in conditions where the immunized host has prior exposure to virulent infection. To examine whether LdCen−/− parasites can induce protective immunity in experimental hosts that have low-level parasitemia from a previous exposure mimicking an asymptomatic condition, we infected C57Bl/6 mice with wild-type Leishmania donovani parasites expressing LLO epitope (LdWTLLO 103, i.v.. After 3 weeks, the mice with low levels of parasitemia were immunized with LdCen−/− parasites expressing 2W epitope (LdCen−/−2W 3 × 106 i.v. to characterize the immune responses in the same host. Antigen experienced CD4+ T cells from the asymptomatic (LdWTLLO infected LdCen−/−2W immunized, and other control groups were enriched using LLO- and 2W-specific tetramers, followed by Flow cytometric analysis. Our analysis showed that comparable CD4+ T cell proliferation and CD4+ memory T cell responses (TCM represented by CD62Lhi, CCR7+, and IL-7R+ T cell populations were induced with LdCen−/−2W in both asymptomatic and naive animals that received LdCen−/− immunization. Upon restimulation with peptide, TCM cells differentiated into effector T cells and there was no significant difference in the recall response in animals with asymptomatic infection. Following virulent challenge, comparable reduction in splenic parasite burden was observed in both asymptomatic and naive LdCen−/− immunized animals concomitant with the development of

Timing of host feeding drives rhythms in parasite replication

KAUST Repository

Prior, Kimberley F.; van der Veen, Daan R.; O’ Donnell, Aidan J.; Cumnock, Katherine; Schneider, David; Pain, Arnab; Subudhi, Amit; Ramaprasad, Abhinay; Rund, Samuel S. C.; Savill, Nicholas J.; Reece, Sarah E.

2018-01-01

by the central, light-entrained circadian oscillator in the brain, determine the timing (phase) of parasite rhythms. Further investigation reveals that parasite rhythms correlate closely with blood glucose rhythms. In addition, we show that parasite rhythms

Bacterial and parasitic diseases of parrots.

Science.gov (United States)

Doneley, Robert J T

2009-09-01

As wild-caught birds become increasingly rare in aviculture, there is a corresponding decline in the incidence of bacterial and parasitic problems and an increase in the recognition of the importance of maintaining health through better nutrition and husbandry. Nevertheless, the relatively close confines of captivity mean an increased pathogen load in the environment in which companion and aviary parrots live. This increased pathogen load leads to greater exposure of these birds to bacteria and parasites, and consequently a greater risk of infection and disease. This article discusses bacterial and parasitic infections in companion and aviary parrots. It includes the origins, pathogens, diagnosis, treatment, and some of the associated risk factors.

Parasitic Infections In A Developing Country: The Vermiform ...

African Journals Online (AJOL)

The vermiform appendix may become a yielding target and an innocent victim of intestinal parasitism. This is likely to occur more readily in those parts of the developing world in which the parasitic load in the community is high. This high parasitic load more commonly afflicts people of low socio-economic class. This report is ...

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.

The effect of parasites on wildlife

NARCIS (Netherlands)

Borgsteede, F.H.M.

1996-01-01

Populations of animals which live in the wild are regulated by many biotic and abiotic factors. Parasites are one of the biotic factors. Parasites may influence their hosts in different ways. They may cause the death of the host due to a direct lethal effect or an indirect effect. Direct lethal

Implications of Plasmodium vivax Biology for Control, Elimination, and Research

Science.gov (United States)

Olliaro, Piero L.; Barnwell, John W.; Barry, Alyssa; Mendis, Kamini; Mueller, Ivo; Reeder, John C.; Shanks, G. Dennis; Snounou, Georges; Wongsrichanalai, Chansuda

2016-01-01

This paper summarizes our current understanding of the biology of Plasmodium vivax, how it differs from Plasmodium falciparum, and how these differences explain the need for P. vivax-tailored interventions. The article further pinpoints knowledge gaps where investments in research are needed to help identify and develop such specific interventions. The principal obstacles to reduce and eventually eliminate P. vivax reside in 1) its higher vectorial capacity compared with P. falciparum due to its ability to develop at lower temperature and over a shorter sporogonic cycle in the vector, allowing transmission in temperate zones and making it less sensitive to vector control measures that are otherwise effective on P. falciparum; 2) the presence of dormant liver forms (hypnozoites), sustaining multiple relapsing episodes from a single infectious bite that cannot be diagnosed and are not susceptible to any available antimalarial except primaquine, with routine deployment restricted by toxicity; 3) low parasite densities, which are difficult to detect with current diagnostics leading to missed diagnoses and delayed treatments (and protracted transmission), coupled with 4) transmission stages (gametocytes) occurring early in acute infections, before infection is diagnosed. PMID:27799636

Implications of Plasmodium vivax Biology for Control, Elimination, and Research.

Science.gov (United States)

Olliaro, Piero L; Barnwell, John W; Barry, Alyssa; Mendis, Kamini; Mueller, Ivo; Reeder, John C; Shanks, G Dennis; Snounou, Georges; Wongsrichanalai, Chansuda

2016-12-28

This paper summarizes our current understanding of the biology of Plasmodium vivax, how it differs from Plasmodium falciparum, and how these differences explain the need for P. vivax-tailored interventions. The article further pinpoints knowledge gaps where investments in research are needed to help identify and develop such specific interventions. The principal obstacles to reduce and eventually eliminate P. vivax reside in 1) its higher vectorial capacity compared with P. falciparum due to its ability to develop at lower temperature and over a shorter sporogonic cycle in the vector, allowing transmission in temperate zones and making it less sensitive to vector control measures that are otherwise effective on P. falciparum; 2) the presence of dormant liver forms (hypnozoites), sustaining multiple relapsing episodes from a single infectious bite that cannot be diagnosed and are not susceptible to any available antimalarial except primaquine, with routine deployment restricted by toxicity; 3) low parasite densities, which are difficult to detect with current diagnostics leading to missed diagnoses and delayed treatments (and protracted transmission), coupled with 4) transmission stages (gametocytes) occurring early in acute infections, before infection is diagnosed. © The American Society of Tropical Medicine and Hygiene.

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.

12 CFR 4.38 - Restrictions on dissemination of released information.

Science.gov (United States)

2010-01-01

... dissemination of released information. (a) Records. The OCC may condition a decision to release non-public OCC... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Restrictions on dissemination of released information. 4.38 Section 4.38 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY...

Parasites Promote and When Might They Constrain Ecological Speciation?

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Anssi Karvonen

2012-01-01

Full Text Available Research on speciation and adaptive radiation has flourished during the past decades, yet factors underlying initiation of reproductive isolation often remain unknown. Parasites represent important selective agents and have received renewed attention in speciation research. We review the literature on parasite-mediated divergent selection in context of ecological speciation and present empirical evidence for three nonexclusive mechanisms by which parasites might facilitate speciation: reduced viability or fecundity of immigrants and hybrids, assortative mating as a pleiotropic by-product of host adaptation, and ecologically-based sexual selection. We emphasise the lack of research on speciation continuums, which is why no study has yet made a convincing case for parasite driven divergent evolution to initiate the emergence of reproductive isolation. We also point interest towards selection imposed by single versus multiple parasite species, conceptually linking this to strength and multifariousness of selection. Moreover, we discuss how parasites, by manipulating behaviour or impairing sensory abilities of hosts, may change the form of selection that underlies speciation. We conclude that future studies should consider host populations at variable stages of the speciation process, and explore recurrent patterns of parasitism and resistance that could pinpoint the role of parasites in imposing the divergent selection that initiates ecological speciation.

The inverse niche model for food webs with parasites

Science.gov (United States)

Warren, Christopher P.; Pascual, Mercedes; Lafferty, Kevin D.; Kuris, Armand M.

2010-01-01

Although parasites represent an important component of ecosystems, few field and theoretical studies have addressed the structure of parasites in food webs. We evaluate the structure of parasitic links in an extensive salt marsh food web, with a new model distinguishing parasitic links from non-parasitic links among free-living species. The proposed model is an extension of the niche model for food web structure, motivated by the potential role of size (and related metabolic rates) in structuring food webs. The proposed extension captures several properties observed in the data, including patterns of clustering and nestedness, better than does a random model. By relaxing specific assumptions, we demonstrate that two essential elements of the proposed model are the similarity of a parasite's hosts and the increasing degree of parasite specialization, along a one-dimensional niche axis. Thus, inverting one of the basic rules of the original model, the one determining consumers' generality appears critical. Our results support the role of size as one of the organizing principles underlying niche space and food web topology. They also strengthen the evidence for the non-random structure of parasitic links in food webs and open the door to addressing questions concerning the consequences and origins of this structure.

Host Specificity in the Parasitic Plant Cytinus hypocistis

International Nuclear Information System (INIS)

Thorogood, C.J.; Hiscock, S.J.

2007-01-01

Host specificity in the parasitic plant Cytinus hypocistis was quantified at four sites in the Algarve region of Portugal from 2002 to 2007. The parasite was found to be locally host specific, and only two hosts were consistently infected: Halimium halimifolium and Cistus monspeliensis. C. hypocistis did not infect hosts in proportion to their abundance; at three sites, 100% of parasites occurred on H. halimifolium which represented just 42.4%, 3% and 19.7% of potential hosts available, respectively. At the remaining site, where H. halimifolium was absent, 100% of parasites occurred on C. monspeliensis which represented 81.1% of potential hosts available. Other species of potential host were consistently uninfected irrespective of their abundance. Ecological niche divergence of host plants H. halimifolium and C. monspeliensis may isolate host-specific races of C. hypocistis, thereby potentially driving allopatric divergence in this parasitic plant.

Predictors of Host Specificity among Behavior-Manipulating Parasites

DEFF Research Database (Denmark)

Fredensborg, B. L.

2014-01-01

specifically, hosts’ behavioral modification that involves interaction with the central nervous system presumably restricts parasites to more closely related hosts than does manipulation of the host’s behavior via debilitation of the host’s physiology. The results of the analysis suggest that phylogenetic......-specialist that has a restricted ecological niche that it masters. Parasites that manipulate hosts’ behavior are often thought to represent resource-specialists based on a few spectacular examples of manipulation of the host’s behavior. However, the determinants of which, and how many, hosts a manipulating parasite...... of parasites and hosts. Using individual and multivariate analyses, I examined the effect of the host’s and parasite’s taxonomy, location of the parasite in the host, type of behavioral change, and the effect of debilitation on host-specificity, measured as the mean taxonomic relatedness of hosts...

Tracer techniques for the study of host-parasite relations

International Nuclear Information System (INIS)

Mendgen, K.

1975-01-01

Autoradiographic techniques have been used to study the interaction of many facultative and obligate parasites, including viruses. After feeding the host plant with labelled substrates, labelled material accumulates in the infected cells and seems to penetrate into structures of the parasite. After labelling the parasite, its influence on the host may be studied. We use this technique to study the interaction of host (bean) and parasite (bean rust) during the infection process. After infection with uredospores labelled with tritiated orotic acid, the radioactivity is retained almost completely within the young haustorium at 22 h after inoculation. This may indicate a very small influence of the parasite on its compatible host. In incompatible host-parasite combinations, the infection process proceeds in a different way. The use of autoradiographic techniques to compare combinations of varying compatibilities will be discussed. (author)

Parasites of skipjack, Katsuwonus pelamis, from Madeira, Eastern Atlantic.

Science.gov (United States)

Hermida, Margarida; Cavaleiro, Bárbara; Gouveia, Lídia; Saraiva, Aurélia

2018-04-01

Skipjack tuna, Katsuwonus pelamis, is a tropical species of economic importance for fisheries around the world. It occurs seasonally in subtropical waters around Madeira archipelago, in the warmer months. In this study, a parasitological analysis was carried out on a sample of 30 skipjack caught near Madeira Island. A total of 24 parasite taxa were found in this sample. The skipjack parasite community detected was characterized by a wide diversity of parasites, with a predominance of adult didymozoid trematodes, and high prevalences of Tentacularia coryphaenae cestode larvae and Anisakis sp. larvae. Microhabitat distribution of gill parasites was assessed for the most prevalent species, and correlations between parasite abundance and various host features such as size, condition, and fat content were investigated. Parasite taxa which might be useful as biological tags in future studies of skipjack migrations in the Eastern Atlantic were selected.

Parasitic and fungal infections in synanthropic rodents in an area of urban expansion, Aracaju, Sergipe State, Brazil - doi: 10.4025/actascibiolsci.v36i1.19760

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Adriana Oliveira Guimarães

2013-09-01

Full Text Available This study analysed the prevalence of parasitic and fungal infections in rodents in an area of urban expansion, Aracaju, Brazil. Traps were placed in the area from December 2011 to January 2013. Blood samples, faeces and hair were collected from the animals. We collected a total of 47 rodents; 44 were Rattus rattus, and 3 were Mus musculus. Parasitological evaluation revealed the cestode Hymenolepis diminuta infection in both rodent species. The nematodes Aspiculuris tetraptera and Syphacia obvelata were found in M. musculus, and the commensal Entamoeba coli was found in R. rattus. We observed that 69.2% of the R. rattus and 33.3% of the M. musculus were infected with the haemoparasite Babesia sp. The differential leukocyte count revealed normal (72.3%, neutrophilic (15.9% and lymphocytic (11.4% profiles. The evaluation showed the following species of fungi in the rodents: Aspergillus sp. (77.1%, Penicillium sp. (28.6%, Cladosporium sp. (14.3%, Mucor sp. (14.3%, Curvularia sp. (8.6%, Acremonium sp. (8.6%, Chrysosporium sp. (2.9%, Syncephalostrum sp. (2.9%, Alternaria sp. (2.9%, Trichophyton sp. (2.9% and Scopulariopsis sp. (2.9%. The parasites and fungi found in rodents are potentially zoonotic, and the presence of these household animals demonstrates their potential role as reservoirs and disseminators of fungal and parasitic infections.

Delusions of Disseminated Fungosis

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Ian Gassiep

2014-01-01

Full Text Available Introduction. Delusional infestation is a rare monosymptomatic hypochondriacal psychosis according to The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013. It can be a primary disorder or associated with an underlying psychological or physical disorder. It commonly presents as delusional parasitosis, and less than 1% may be fungi related. We present this case as it is a rare presentation of a rare condition. Case Presentation. Our patient is a 60-year-old Caucasian man who presented with a 7-year history of delusional infestation manifested as a disseminated fungal infection. He had previously been reviewed by multiple physicians for the same with no systemic illness diagnosed. After multiple reviews and thorough investigation we diagnosed him with a likely delusional disorder. As is common with this patient cohort he refused psychiatric review or antipsychotic medication. Conclusion. A delusion of a disseminated fungal infestation is a rare condition. It is exceedingly difficult to treat as these patients often refuse to believe the investigation results and diagnosis. Furthermore, they either refuse or are noncompliant with treatment. Multidisciplinary outpatient evaluation may be the best way to allay patient fears and improve treatment compliance.

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.

Limited dissemination of the wastewater treatment plant core resistome

OpenAIRE

Munck, Christian; Albertsen, Mads; Telke, Amar; Ellabaan, Mostafa M Hashim; Nielsen, Per Halkjær; Sommer, Morten Otto Alexander

2015-01-01

Horizontal gene transfer is a major contributor to the evolution of bacterial genomes and can facilitate the dissemination of antibiotic resistance genes between environmental reservoirs and potential pathogens. Wastewater treatment plants (WWTPs) are believed to play a central role in the dissemination of antibiotic resistance genes. However, the contribution of the dominant members of the WWTP resistome to resistance in human pathogens remains poorly understood. Here we use a combination of...