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Sample records for natural parasite isolates

  1. Microsporidia Are Natural Intracellular Parasites of the Nematode Caenorhabditis elegans

    PubMed Central

    Troemel, Emily R; Félix, Marie-Anne; Whiteman, Noah K; Barrière, Antoine; Ausubel, Frederick M

    2008-01-01

    For decades the soil nematode Caenorhabditis elegans has been an important model system for biology, but little is known about its natural ecology. Recently, C. elegans has become the focus of studies of innate immunity and several pathogens have been shown to cause lethal intestinal infections in C. elegans. However none of these pathogens has been shown to invade nematode intestinal cells, and no pathogen has been isolated from wild-caught C. elegans. Here we describe an intracellular pathogen isolated from wild-caught C. elegans that we show is a new species of microsporidia. Microsporidia comprise a large class of eukaryotic intracellular parasites that are medically and agriculturally important, but poorly understood. We show that microsporidian infection of the C. elegans intestine proceeds through distinct stages and is transmitted horizontally. Disruption of a conserved cytoskeletal structure in the intestine called the terminal web correlates with the release of microsporidian spores from infected cells, and appears to be part of a novel mechanism by which intracellular pathogens exit from infected cells. Unlike in bacterial intestinal infections, the p38 MAPK and insulin/insulin-like growth factor (IGF) signaling pathways do not appear to play substantial roles in resistance to microsporidian infection in C. elegans. We found microsporidia in multiple wild-caught isolates of Caenorhabditis nematodes from diverse geographic locations. These results indicate that microsporidia are common parasites of C. elegans in the wild. In addition, the interaction between C. elegans and its natural microsporidian parasites provides a system in which to dissect intracellular intestinal infection in vivo and insight into the diversity of pathogenic mechanisms used by intracellular microbes. PMID:19071962

  2. Impacts of parasitic plants on natural communities.

    PubMed

    Press, Malcolm C; Phoenix, Gareth K

    2005-06-01

    Parasitic plants have profound effects on the ecosystems in which they occur. They are represented by some 4000 species and can be found in most major biomes. They acquire some or all of their water, carbon and nutrients via the vascular tissue of the host's roots or shoots. Parasitism has major impacts on host growth, allometry and reproduction, which lead to changes in competitive balances between host and nonhost species and therefore affect community structure, vegetation zonation and population dynamics. Impacts on hosts may further affect herbivores, pollinators and seed vectors, and the behaviour and diversity of these is often closely linked to the presence and abundance of parasitic plants. Parasitic plants can therefore be considered as keystone species. Community impacts are mediated by the host range of the parasite (the diversity of species that can potentially act as hosts) and by their preference and selection of particular host species. Parasitic plants can also alter the physical environment around them--including soil water and nutrients, atmospheric CO2 and temperature--and so may also be considered as ecosystem engineers. Such impacts can have further consequences in altering the resource supply to and behaviour of other organisms within parasitic plant communities.

  3. Parasite transmission in a natural multihost-multiparasite community.

    PubMed

    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'.

  4. Parasitism of Lepidopterous Stem Borers in Cultivated and Natural Habitats

    PubMed Central

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests. PMID:21526933

  5. Parasitism of lepidopterous stem borers in cultivated and natural habitats.

    PubMed

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests.

  6. Techniques for Isolation and Evaluation of Fungal Parasites of Heterodera glycines

    PubMed Central

    Kim, D. G.; Riggs, R. D.

    1994-01-01

    A facultative fungal parasite, Arkansas Fungus 18 (ARF18), was isolated from at least 10 different sources of Heterodera glycines in different areas in the United States. Techniques used for isolation and in vitro evaluation of fungal parasites of H. glycines were described. Successful isolation of probable egg parasites depends on isolation from individual eggs. Selective isolation and a simple, yet definitive, screening system can increase the possibility of identifying effective biocontrol agents. PMID:19279930

  7. Natural Products as Source of Therapeutics against Parasitic Diseases.

    PubMed

    Hertweck, Christian

    2015-12-01

    An end to suffering: Parasitic infections with protozoa and worms cause unimaginable misery, in particular in the tropics. Fortunately, natural products, such as the antimalarial artemisinin (1) and the anthelmintic avermectin (2) were discovered and developed into therapeutics. These major achievements now culminated in the 2015 Nobel Prize for Medicine.

  8. Parasites

    MedlinePlus

    ... Where to Find Further Information on Parasitic Diseases Public Health Image Library Freedom of Information Act (FOIA) Explore Parasites A-Z Index Parasites Glossary Education and Training Healthy Water Travelers Health Laboratory ... Science Parasites About Parasites Animals ...

  9. Natural Products as a Source for Treating Neglected Parasitic Diseases

    PubMed Central

    Ndjonka, Dieudonné; Rapado, Ludmila Nakamura; Silber, Ariel M.; Liebau, Eva; Wrenger, Carsten

    2013-01-01

    Infectious diseases caused by parasites are a major threat for the entire mankind, especially in the tropics. More than 1 billion people world-wide are directly exposed to tropical parasites such as the causative agents of trypanosomiasis, leishmaniasis, schistosomiasis, lymphatic filariasis and onchocerciasis, which represent a major health problem, particularly in impecunious areas. Unlike most antibiotics, there is no “general” antiparasitic drug available. Here, the selection of antiparasitic drugs varies between different organisms. Some of the currently available drugs are chemically de novo synthesized, however, the majority of drugs are derived from natural sources such as plants which have subsequently been chemically modified to warrant higher potency against these human pathogens. In this review article we will provide an overview of the current status of plant derived pharmaceuticals and their chemical modifications to target parasite-specific peculiarities in order to interfere with their proliferation in the human host. PMID:23389040

  10. Natural parasite infection affects the tolerance but not the response to a simulated secondary parasite infection.

    PubMed

    Lutermann, Heike; Bodenstein, Chimoné; Bennett, Nigel C

    2012-01-01

    Parasites deplete the resources of their host and can consequently affect the investment in competing traits (e.g. reproduction and immune defence). The immunocompetence handicap hypothesis posits that testosterone (T) mediates trade-offs between parasite defence and reproductive investment by suppressing immune function in male vertebrates while more recently a role for glucocorticoids (e.g. cortisol (C)) in resource allocation has been suggested. These hypotheses however, have not always found support in wild animals, possibly because most studies focus on a single parasite species, whereas infections with multiple parasites are the rule in nature. We measured body mass, T- and C-levels of wild male highveld mole-rats (Cryptomys hottentotus pretoriae) naturally uninfected or infected with a cestode (Mathevotaenia sp.) right after capture. Subsequently, we injected animals subcutaneously with a lipopolysaccharide (LPS) to simulate a bacterial infection and recorded changes in body mass, food intake, haematological parameters and hormone levels. As a control, animals were injected with saline. Natural infection neither affected initial body mass nor C-levels, whereas infected males had significantly reduced T-levels. We observed significant reductions in food intake, body mass and T in response to LPS but not saline while C increased. However, this response did not vary with infection status. In contrast, final body mass and some haematological parameters were significantly lowered in infected males. Our results suggest that naturally infected males are able to compensate for resource depletion by physiological adjustments. However, this leaves them less tolerant to the challenges of a secondary infection.

  11. A model for studying isolation mechanisms in parasite populations: the genus Lepeophtheirus (Copepoda, Caligidae).

    PubMed

    De Meeus, T; Renaud, F; Gabrion, C

    1990-05-01

    In the Mediterranean, the parasitic copepod Lepeophtheirus thompsoni Baird, 1850 specifically infests turbot (Psetta maxima L., 1758), whereas L. europaensis Zeddam, Berrebi, Renaud, Raibaut, and Gabrion, 1988 infests brill (Scophthalmus rhombus L., 1758) and flounder (Platichthys flesus L., 1758). Experimental infestation of turbot by copepods from each of the three fish species showed an absence of any physiological incompatibility preventing natural development of the two parasite species, at least on one host species, i.e., the turbot. Moreover, interspecific hybrids were obtained experimentally, which implies that 1) there is no strict genetic barrier between the two species and 2) the natural prezygotic isolation results from a choice of the most favorable habitat. We discuss the origin and possible consequences of the presence, in the Mediterranean, of L. europaensis on brill and flounder, two hosts separated by their taxonomic status and ecobiology.

  12. Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback

    PubMed Central

    El Nagar, Aliya

    2016-01-01

    Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation. PMID:27512145

  13. Natural parasitic infection of the golden apple snail, Pomacea canaliculata.

    PubMed

    Keawjam, R S; Poonswad, P; Upatham, E S; Banpavichit, S

    1993-03-01

    Golden apple snails, Pomacea canaliculata, were collected once a month during a year to search for their natural parasites. The collections were made at two localities having different ecological environments. Of 576 collected snails from a canal, 176 individuals (30.6%) were infected by three groups of metacercariae. These parasites were amphistome, distome and echinostome metacercariae, which had prevalences of 23.5, 19.5 and 0.5%, respectively. The incidence of infection was highest (68.4% in October) when the snail population was composed of the old, juvenile and young Pomacea. Amphistome metacercariae were found most frequently and echinostome metacercariae the least frequently; both parasites were localized in the foot muscle of the snails and had a Shannon index of zero. The range of amphistomes was 1 to 115 with the mean +/- SD of 1 +/- 2 and 95% CL of 1, 2. Distome metacercariae were found primarily in the heart (range: 1-13), and also in the foot muscle (range: 1-5) and kidney (range: 1-14), with a Shannon index of 0.4. The means +/- SD (with 95% CL) were 3 +/- 4 (95% CL = 1, 5), 3 +/- 4 (95% CL = 2, 4) and 2 +/- 1 (95% CL = 1, 2) for the foot muscle, heart and kidney, respectively. The snails from a pond, another locality, had a low proportion of infected individuals. Of 605 snails, only 24 individuals (4.0%) were infected, with the prevalence of amphistomes, distomes and echinostomes being 0.8, 1.8 and 2.1%, respectively. The incidence of infection for each month was zero or less than 10%, except in May when it was 30.2%.

  14. Fundamental factors determining the nature of parasite aggregation in hosts.

    PubMed

    Gourbière, Sébastien; Morand, Serge; Waxman, David

    2015-01-01

    The distribution of parasites in hosts is typically aggregated: a few hosts harbour many parasites, while the remainder of hosts are virtually parasite free. The origin of this almost universal pattern is central to our understanding of host-parasite interactions; it affects many facets of their ecology and evolution. Despite this, the standard statistical framework used to characterize parasite aggregation does not describe the processes generating such a pattern. In this work, we have developed a mathematical framework for the distribution of parasites in hosts, starting from a simple statistical description in terms of two fundamental processes: the exposure of hosts to parasites and the infection success of parasites. This description allows the level of aggregation of parasites in hosts to be related to the random variation in these two processes and to true host heterogeneity. We show that random variation can generate an aggregated distribution and that the common view, that encounters and success are two equivalent filters, applies to the average parasite burden under neutral assumptions but it does not apply to the variance of the parasite burden, and it is not true when heterogeneity between hosts is incorporated in the model. We find that aggregation decreases linearly with the number of encounters, but it depends non-linearly on parasite success. We also find additional terms in the variance of the parasite burden which contribute to the actual level of aggregation in specific biological systems. We have derived the formal expressions of these contributions, and these provide new opportunities to analyse empirical data and tackle the complexity of the origin of aggregation in various host-parasite associations.

  15. Host-parasite genetic interactions and virulence-transmission relationships in natural populations of monarch butterflies.

    PubMed

    de Roode, Jacobus C; Altizer, Sonia

    2010-02-01

    Evolutionary models predict that parasite virulence (parasite-induced host mortality) can evolve as a consequence of natural selection operating on between-host parasite transmission. Two major assumptions are that virulence and transmission are genetically related and that the relative virulence and transmission of parasite genotypes remain similar across host genotypes. We conducted a cross-infection experiment using monarch butterflies and their protozoan parasites from two populations in eastern and western North America. We tested each of 10 host family lines against each of 18 parasite genotypes and measured virulence (host life span) and parasite transmission potential (spore load). Consistent with virulence evolution theory, we found a positive relationship between virulence and transmission across parasite genotypes. However, the absolute values of virulence and transmission differed among host family lines, as did the rank order of parasite clones along the virulence-transmission relationship. Population-level analyses showed that parasites from western North America caused higher infection levels and virulence, but there was no evidence of local adaptation of parasites on sympatric hosts. Collectively, our results suggest that host genotypes can affect the strength and direction of selection on virulence in natural populations, and that predicting virulence evolution may require building genotype-specific interactions into simpler trade-off models.

  16. Bacteria isolated from parasitic nematodes--a potential novel vector of pathogens?

    PubMed

    Lacharme-Lora, Lizeth; Salisbury, Vyv; Humphrey, Tom J; Stafford, Kathryn; Perkins, Sarah E

    2009-12-21

    Bacterial pathogens are ubiquitous in soil and water - concurrently so are free-living helminths that feed on bacteria. These helminths fall into two categories; the non-parasitic and the parasitic. The former have been the focus of previous work, finding that bacterial pathogens inside helminths are conferred survival advantages over and above bacteria alone in the environment, and that accidental ingestion of non-parasitic helminths can cause systemic infection in vertebrate hosts. Here, we determine the potential for bacteria to be associated with parasitic helminths. After culturing helminths from fecal samples obtained from livestock the external bacteria were removed. Two-hundred parasitic helminths from three different species were homogenised and the bacteria that were internal to the helminths were isolated and cultured. Eleven different bacterial isolates were found; of which eight were indentified. The bacteria identified included known human and cattle pathogens. We concluded that bacteria of livestock can be isolated in parasitic helminths and that this suggests a mechanism by which bacteria, pathogenic or otherwise, can be transmitted between individuals. The potential for helminths to play a role as pathogen vectors poses a potential livestock and human health risk. Further work is required to assess the epidemiological impact of this finding.

  17. Parasitic, bacterial and viral pathogens isolated from diarrhoeal and routine stool specimens of urban Bangladeshi children.

    PubMed

    Stanton, B; Silimperi, D R; Khatun, K; Kay, B; Ahmed, S; Khatun, J; Alam, K

    1989-02-01

    Few data exist in Bangladesh on longitudinal, community-based studies of bacterial or parasitic pathogens identified in routine and diarrhoeal stools of urban dwelling children. We undertook the following study on 343 children of age less than 6 years who resided in one of 51 slum settings in Dhaka, Bangladesh, between October 1984 and February 1986. Specimens from diarrhoeal episodes and from routine stools obtained at 3-monthly intervals were examined for parasites, rotavirus and pathogenic bacteria. Parasites were isolated from 509 (51%) of the 1006 routine stools and from 95 (42%) of the 225 diarrhoeal stools. Isolation rates steadily increased with age. Ascaris lumbricoides and Trichuris trichiura accounted for approximately 80% of all parasitic isolates in routine and diarrhoeal stools. Giardia lamblia was isolated from 11% diarrhoeal stools. Entamoeba histolytica was an uncommon isolate (less than 1%). Bacterial pathogens were identified in 55 (24%) of the diarrhoeal stools but were identified in only 164 (16%) of the 1028 routine stools examined (P less than 0.01). Toxigenic Escherichia coli, Shigellae and Campylobacter were the most frequent isolates from diarrhoeal and routine specimens. This pathogen profile appears to be more in keeping with that from urban settings in other developing countries than from rural Bangladesh, suggesting that extrapolations from rural-based data should not be made for urban settings.

  18. Isolation and structure elucidaton of polyphenols from Loranthus micranthus Linn. parasitic on Hevea brasiliensis with antiinflammatory property

    PubMed Central

    Agbo, Matthias Onyebuchi; Nworu, Chukwuemeka Sylvester; Okoye, Festus Basden Chied; Osadebe, Patience Ogoamaka

    2014-01-01

    The present study was carried out to evaluate the anti-inflammatory activities of polyphenols isolated from the leaves of mistletoe (Loranthus micranthus Linn.) parasitic on Hevea brasiliensis. The anti-inflammatory properties of the isolated compounds were evaluated on the basis of their ability to inhibit the production of nitric oxide (NO) and tumuor necrosis factor-α (TNF-α) in lipopolysaccharide (LPS) activated RAW 264.7 mouse macrophages. Semi-preparative HPLC separation of the ethyl acetate (EtOAc) and butanol (n-BuOH) fractions of the leaves of mistletoe (Loranthus micranthus Linn) parasitic on Hevea brasiliensis led to the isolation of four polyphenols: 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG) (1); (-)-epicatechin-3-O-(3″-O-methyl)-gallate (ECG3″Me) (2); rutin (3) and peltatoside (4). Compounds 1-4 were isolated for the first time from this plant while 1 was isolated for the first time in nature. These compounds (1-4) were readily identified by comparison of their spectroscopic data with those reported in the literature. The polyphenols proved to have anti-inflammatory activity as evidenced by the suppression of inducible nitric oxide (iNO) and cytokine (TNF-α) levels in the culture supernatant of lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. However, the study showed that the quercetin diglycosides showed stronger inhibition of proinflammatory mediators than the epicatechin derivates. These data provide evidence that polyphenolic compounds isolated from the mistletoe parasitic on Hevea brasiliensis may contribute to its anti-inflammatory properties by inhibiting the expression of inducible nitric oxide and proinflammatory cytokines such as tumour necrosis factor-α. PMID:26417309

  19. Antigenic Diversity of the Plasmodium vivax Circumsporozoite Protein in Parasite Isolates of Western Colombia

    PubMed Central

    Hernández-Martínez, Miguel Ángel; Escalante, Ananías A.; Arévalo-Herrera, Myriam; Herrera, Sócrates

    2011-01-01

    Circumsporozoite (CS) protein is a malaria antigen involved in sporozoite invasion of hepatocytes, and thus considered to have good vaccine potential. We evaluated the polymorphism of the Plasmodium vivax CS gene in 24 parasite isolates collected from malaria-endemic areas of Colombia. We sequenced 27 alleles, most of which (25/27) corresponded to the VK247 genotype and the remainder to the VK210 type. All VK247 alleles presented a mutation (Gly → Asn) at position 28 in the N-terminal region, whereas the C-terminal presented three insertions: the ANKKAGDAG, which is common in all VK247 isolates; 12 alleles presented the insertion GAGGQAAGGNAANKKAGDAG; and 5 alleles presented the insertion GGNAGGNA. Both repeat regions were polymorphic in gene sequence and size. Sequences coding for B-, T-CD4+, and T-CD8+ cell epitopes were found to be conserved. This study confirms the high polymorphism of the repeat domain and the highly conserved nature of the flanking regions. PMID:21292878

  20. The effects of plant dispersion and prey density on parasitism rates in a naturally patchy habitat.

    PubMed

    Doak, P

    2000-03-01

    Despite extensive research on parasitoid-prey interactions and especially the effects of heterogeneity in parasitism on stability, sources of heterogeneity other than prey density have been little investigated. This research examines parasitism rates by three parasitoid species in relationship to prey density and habitat spatial pattern. The herbivore Itame andersoni (Geometridae) inhabits a subdivided habitat created by patches of its host plant, Dryas drummondii, in the Wrangell Mountains of Alaska. Dryas colonizes glacial moraines and spreads clonally to form distinct patches. Habitat subdivision occurs both on the patch scale and on the larger spatial scale of sites due to patchy successional patterns. Itame is attacked by three parasitoids: an ichneumonid wasp (Campoletis sp.), a braconid wasp (Aleiodes n. sp.), and the tachinid fly (Phyrxe pecosensis). I performed a large survey study at five distinct sites and censused Itame density and parasitism rates in 206 plant patches for 1-3 years. Parasitism rates varied with both plant patch size and isolation and also between sites, and the highest rates of overall parasitism were in the smallest patches. However, the effects of both small- and large-scale heterogeneity on parasitism differed for the three parasitoid species. There was weak evidence that Itame density was positively correlated with parasitism for the braconid and tachinid at the patch scale, but density effects differed for different patch sizes, patch isolations, and sites. At the site scale, there was no evidence of positive, but some indication of negative density-dependent parasitism. These patterns do not appear to be driven by negative interactions between the three parasitoid species, but reflect, rather, individual differences in habitat use and response to prey density. Finally, there was no evidence that parasitism strongly impacted the population dynamics of Itame. These results demonstrate the importance of considering habitat pattern

  1. Optimization of parasitic isolators in laser fusion systems

    SciTech Connect

    Figueira, J.F.; Phipps, C.R. Jr.

    1980-01-01

    The results of model calculations for the optimization of the efficiency of high-gain amplifier systems stabilized by saturable absorbers are described. It is shown that the isolator performance can be characterized by a convenient figure of merit.

  2. Potential of marine natural products against drug-resistant fungal, viral, and parasitic infections.

    PubMed

    Abdelmohsen, Usama Ramadan; Balasubramanian, Srikkanth; Oelschlaeger, Tobias A; Grkovic, Tanja; Pham, Ngoc B; Quinn, Ronald J; Hentschel, Ute

    2017-02-01

    Antibiotics have revolutionised medicine in many aspects, and their discovery is considered a turning point in human history. However, the most serious consequence of the use of antibiotics is the concomitant development of resistance against them. The marine environment has proven to be a very rich source of diverse natural products with significant antibacterial, antifungal, antiviral, antiparasitic, antitumour, anti-inflammatory, antioxidant, and immunomodulatory activities. Many marine natural products (MNPs)-for example, neoechinulin B-have been found to be promising drug candidates to alleviate the mortality and morbidity rates caused by drug-resistant infections, and several MNP-based anti-infectives have already entered phase 1, 2, and 3 clinical trials, with six approved for usage by the US Food and Drug Administration and one by the EU. In this Review, we discuss the diversity of marine natural products that have shown in-vivo efficacy or in-vitro potential against drug-resistant infections of fungal, viral, and parasitic origin, and describe their mechanism of action. We highlight the drug-like physicochemical properties of the reported natural products that have bioactivity against drug-resistant pathogens in order to assess their drug potential. Difficulty in isolation and purification procedures, toxicity associated with the active compound, ecological impacts on natural environment, and insufficient investments by pharmaceutical companies are some of the clear reasons behind market failures and a poor pipeline of MNPs available to date. However, the diverse abundance of natural products in the marine environment could serve as a ray of light for the therapy of drug-resistant infections. Development of resistance-resistant antibiotics could be achieved via the coordinated networking of clinicians, microbiologists, natural product chemists, and pharmacologists together with pharmaceutical venture capitalist companies.

  3. Experimental elimination of parasites in nature leads to the evolution of increased resistance in hosts

    PubMed Central

    Dargent, Felipe; Scott, Marilyn E.; Hendry, Andrew P.; Fussmann, Gregor F.

    2013-01-01

    A reduction in the strength of selection is expected to cause the evolution of reduced trait expression. Elimination of a parasite should thus cause the evolution of reduced resistance to that parasite. To test this prediction in nature, we studied the fourth- and eighth-generation descendants of guppies (Poecilia reticulata) introduced into four natural streams following experimental elimination of a common and deleterious parasite (Gyrodactylus spp.). After two generations of laboratory rearing to control for plasticity and maternal effects, we infected individual fish to assess their resistance to the parasite. Contrary to theoretical expectations, the introduced guppy populations had rapidly and repeatably evolved increased resistance to the now-absent parasite. This evolution was not owing to a resistance-tolerance trade-off, nor to differences in productivity among the sites. Instead, a leading candidate hypothesis is that the rapid life-history evolution typical in such introductions pleiotropically increases parasite resistance. Our study adds a new dimension to the growing evidence for contemporary evolution in the wild, and also points to the need for a re-consideration of simple expectations from host–parasite theory. In particular, our results highlight the need for increased consideration of multiple sources of selection and pleiotropy when studying evolution in natural contexts. PMID:24197417

  4. Natural proteins: Sources, isolation, characterization and applications

    PubMed Central

    Nehete, Jitendra Y.; Bhambar, Rajendra S.; Narkhede, Minal R.; Gawali, Sonali R.

    2013-01-01

    Worldwide, plant protein contributes substantially as a food resource because it contains essential amino acids for meeting human physiological requirements. However, many versatile plant proteins are used as medicinal agents as they are produced by using molecular tools of biotechnology. Proteins can be obtained from plants, animals and microorganism cells. The abundant economical proteins can be obtained from plant seeds. These natural proteins are obtained by isolation procedures depending on the physicochemical properties of proteins. Isolation and purification of single protein from cells containing mixtures of unrelated proteins is achievable due to the physical and chemical attributes of proteins. The following characteristics are unique to each protein: Amino acid composition, sequence, subunit structures, size, shape, net charge, isoelectric point, solubility, heat stability and hydrophobicity. Based on these properties, various methods of isolation exist, like salting out and isoionic precipitation. Purification of proteins is quiet challenging and, therefore, several approaches like sodium dodecyl sulfate gel electrophoresis and chromatography are available. Characterization of proteins can be performed by mass spectrometry/liquid chromatography-mass spectrometry (LC-MS). The amino acid sequence of a protein can be detected by using tandem mass spectrometry. In this article, a review has been made on the sources, isolation, purification and characterization of natural proteins. PMID:24347918

  5. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    PubMed

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  6. Insights From Natural Host-Parasite Interactions: The Drosophila Model

    PubMed Central

    Keebaugh, Erin S.; Schlenke, Todd A.

    2013-01-01

    Immune responses against opportunistic pathogens have been extensively studied in Drosophila, leading to a detailed map of the genetics behind innate immunity networks including the Toll, Imd, Jak-Stat, and JNK pathways. However, immune mechanisms of other organisms, particularly plants, have primarily been investigated using natural pathogens. It was the use of natural pathogens in plant research that revealed the plant R/Avr system, a specialized immune response derived from antagonistic coevolution between plant immune proteins and their natural pathogens’ virulence proteins. Thus, we recommend that researchers begin to use natural Drosophila pathogens to identify novel immune mechanisms that may have arisen through antagonistic coevolution with common natural pathogens. In this review, we address the benefits of using natural pathogens in research, describe the known natural pathogens of Drosophila, and discuss exciting prospects for future research on select natural pathogens of Drosophila. PMID:23764256

  7. Food plant derived disease tolerance and resistance in a natural butterfly-plant-parasite interactions.

    PubMed

    Sternberg, Eleanore D; Lefèvre, Thierry; Li, James; de Castillejo, Carlos Lopez Fernandez; Li, Hui; Hunter, Mark D; de Roode, Jacobus C

    2012-11-01

    Organisms can protect themselves against parasite-induced fitness costs through resistance or tolerance. Resistance includes mechanisms that prevent infection or limit parasite growth while tolerance alleviates the fitness costs from parasitism without limiting infection. Although tolerance and resistance affect host-parasite coevolution in fundamentally different ways, tolerance has often been ignored in animal-parasite systems. Where it has been studied, tolerance has been assumed to be a genetic mechanism, unaffected by the host environment. Here we studied the effects of host ecology on tolerance and resistance to infection by rearing monarch butterflies on 12 different species of milkweed food plants and infecting them with a naturally occurring protozoan parasite. Our results show that monarch butterflies experience different levels of tolerance to parasitism depending on the species of milkweed that they feed on, with some species providing over twofold greater tolerance than other milkweed species. Resistance was also affected by milkweed species, but there was no relationship between milkweed-conferred resistance and tolerance. Chemical analysis suggests that infected monarchs obtain highest fitness when reared on milkweeds with an intermediate concentration, diversity, and polarity of toxic secondary plant chemicals known as cardenolides. Our results demonstrate that environmental factors-such as interacting species in ecological food webs-are important drivers of disease tolerance.

  8. Leishmania major: Genetic Profiles of the Parasites Isolated from Chabahar, Southeastern Iran by PPIP-PCR

    PubMed Central

    SHARIFI-RAD, Mehdi; DABIRZADEH, Mansour; SHARIFI, Iraj; BABAEI, Zahra

    2016-01-01

    Background: Leishmaniasis is important vector-borne parasitic disease worldwide, caused by the genus Leishmania. The objective of the current study was to identify genetic polymorphism in L. major, one of the species causing cutaneous leishmaniasis (CL), isolated from southeastern Iran, using Permissively Primed Intergenic Polymorphic-Polymerase Chain Reaction (PPIP-PCR) method. Methods: Overall, 340 patients with suspected CL were examined. They referred to the Central Laboratory in Chabahar, Iran during Apr 2013 to Feb 2014. Microscopic examination of Giemsa-stained slides from lesions as well as aspirates cultured in Novy- Mac Neal-Nicolle (NNN) Media was employed in order to diagnose CL in these patients. Our analyses detected 86 suspected subjects as having CL from which 35 isolates were cultured successfully. PPIP-PCR method was performed on extracted genomic DNA from selected isolates in order to determine the genetic polymorphism among L. major isolates. Results: The electrophoresis patterns demonstrated two genetic profiles including A or A1 patterns between all samples tested. Frequency of A and A1 sub-types were 33 (94.3%) and two (5.7%), respectively. Conclusion: Both host and parasite factors may contribute to the clinical profile of human leishmaniasis in the endemic foci of the disease. Here we showed that genetic variations pertaining to the Leishmania parasites might determine, in part, the clinical outcomes of human leishmaniasis. PMID:28127333

  9. Differential Gene Expression in Five Isolates of the Clam Pathogen, Quahog Parasite Unknown (QPX).

    PubMed

    Rubin, Ewelina; Tanguy, Arnaud; Pales Espinosa, Emmanuelle; Allam, Bassem

    2017-02-07

    Quahog parasite unknown (QPX) is a thraustochytrid protist that infects the hard clam, Mercenaria mercenaria, causing significant economic losses along the northeastern coasts of North America. Previous investigations noted differences in growth dynamics and virulence in QPX cells from different geographic locations. In order to probe the molecular determinants for these variations, we investigated the transcriptomic profiles of five geographically-distinct QPX isolates using custom 15K 60-mer oligonucleotide arrays. A total of 1263 transcripts were differentially expressed (DE) among the five QPX isolates. The hierarchical clustering of gene expression profiles showed that the QPX isolates from Raritan Bay (RB, NY) and from Provincetown Harbor (MA) were more similar to each other and diverged from QPX isolates from Peconic Bay (PB, NY) and Old Plantation Creek (VA) which had more similar gene expression profiles. The most prominent difference was based on 78 transcripts coding for heat shock proteins DE between the five QPX isolates. The study generated contrasting transcriptomic profiles for QPX isolated from northern (MA) and deeper (RB, NY) locations as compared to southern (VA) and shallower (PB, NY) areas, suggesting the adaptation of the parasite to local environmental, in particular temperature, conditions. This article is protected by copyright. All rights reserved.

  10. Interactive effects of wildfire, forest management, and isolation on amphibian and parasite abundance

    USGS Publications Warehouse

    Hossack, Blake R.; Corn, P. Stephen; Winsor H. Lowe,; R. Kenneth Honeycutt,; Sean A. Parks,

    2013-01-01

    Projected increases in wildfire and other climate-driven disturbances will affect populations and communities worldwide, including host–parasite relationships. Research in temperate forests has shown that wildfire can negatively affect amphibians, but this research has occurred primarily outside of managed landscapes where interactions with human disturbances could result in additive or synergistic effects. Furthermore, parasites represent a large component of biodiversity and can affect host fitness and population dynamics, yet they are rarely included in studies of how vertebrate hosts respond to disturbance. To determine how wildfire affects amphibians and their parasites, and whether effects differ between protected and managed landscapes, we compared abundance of two amphibians and two nematodes relative to wildfire extent and severity around wetlands in neighboring protected and managed forests (Montana, USA). Population sizes of adult, male long-toed salamanders (Ambystoma macrodactylum) decreased with increased burn severity, with stronger negative effects on isolated populations and in managed forests. In contrast, breeding population sizes of Columbia spotted frogs (Rana luteiventris) increased with burn extent in both protected and managed protected forests. Path analysis showed that the effects of wildfire on the two species of nematodes were consistent with differences in their life history and transmission strategies and the responses of their hosts. Burn severity indirectly reduced abundance of soil-transmitted Cosmocercoides variabilis through reductions in salamander abundance. Burn severity also directly reduced C. variabilis abundance, possibly though changes in soil conditions. For the aquatically transmitted nematode Gyrinicola batrachiensis, the positive effect of burn extent on density of Columbia spotted frog larvae indirectly increased parasite abundance. Our results show that effects of wildfire on amphibians depend upon burn extent

  11. Galectin isolated from parasite inhibits remission of experimental autoimmune encephalomyelitis by up-regulating autoantibody

    PubMed Central

    Bing, S J; Ha, D; Ahn, G; Cho, J; Kim, A; Park, S K; Yu, H S; Jee, Y

    2015-01-01

    Recently, parasite infections or parasite-derived products have been suggested as a therapeutic strategy with suppression of immunopathology, which involves the induction of regulatory T cells or/and T helper type 2 (Th2) responses. In a recent study, researchers reported that constructed recombinant galectin (rTl-gal) isolated from an adult worm of the gastrointestinal nematode parasite Toxascaris leonina attenuated clinical symptoms of inflammatory bowel disease in mice treated with dextran sulphate sodium. Noting the role of rTl-gal in inflammatory disease, we attempted to investigate the effect of the parasite via its rTl-gal on neuronal autoimmune disease using experimental autoimmune encephalomyelitis (EAE), a mouse inflammatory and demyelinating autoimmune disease model of human multiple sclerosis. In this model, rTl-gal-treated experimental autoimmune encephalomyelitis (EAE) mice failed to recover after the peak of the disease, leading to persistent central nervous system (CNS) damage, such as demyelination, gliosis and axonal damage. Further, rTl-gal-treated EAE mice markedly increased the number of CD45R/B220+ B cells in both infiltrated inflammation and the periphery, along with the increased production of autoantibody [anti-myelin oligodendrocyte glycoprotein (MOG)35–55] in serum at chronic stage. Upon antigen restimulation, rTl-gal treatment affected the release of overall cytokines, especially interferon (IFN)-γ and tumour necrosis factor (TNF)-α. Our results suggest that galectin isolated from a gastrointestinal parasite can deliver a harmful effect to EAE contrary to its beneficial effect on inflammatory bowel disease. PMID:25619397

  12. Galectin isolated from parasite inhibits remission of experimental autoimmune encephalomyelitis by up-regulating autoantibody.

    PubMed

    Bing, S J; Ha, D; Ahn, G; Cho, J; Kim, A; Park, S K; Yu, H S; Jee, Y

    2015-06-01

    Recently, parasite infections or parasite-derived products have been suggested as a therapeutic strategy with suppression of immunopathology, which involves the induction of regulatory T cells or/and T helper type 2 (Th2) responses. In a recent study, researchers reported that constructed recombinant galectin (rTl-gal) isolated from an adult worm of the gastrointestinal nematode parasite Toxascaris leonina attenuated clinical symptoms of inflammatory bowel disease in mice treated with dextran sulphate sodium. Noting the role of rTl-gal in inflammatory disease, we attempted to investigate the effect of the parasite via its rTl-gal on neuronal autoimmune disease using experimental autoimmune encephalomyelitis (EAE), a mouse inflammatory and demyelinating autoimmune disease model of human multiple sclerosis. In this model, rTl-gal-treated experimental autoimmune encephalomyelitis (EAE) mice failed to recover after the peak of the disease, leading to persistent central nervous system (CNS) damage, such as demyelination, gliosis and axonal damage. Further, rTl-gal-treated EAE mice markedly increased the number of CD45R/B220(+) B cells in both infiltrated inflammation and the periphery, along with the increased production of autoantibody [anti-myelin oligodendrocyte glycoprotein (MOG)35-55 ] in serum at chronic stage. Upon antigen restimulation, rTl-gal treatment affected the release of overall cytokines, especially interferon (IFN)-γ and tumour necrosis factor (TNF)-α. Our results suggest that galectin isolated from a gastrointestinal parasite can deliver a harmful effect to EAE contrary to its beneficial effect on inflammatory bowel disease.

  13. Natural antisense transcripts in Plasmodium falciparum isolates from patients with complicated malaria.

    PubMed

    Subudhi, Amit Kumar; Boopathi, P A; Garg, Shilpi; Middha, Sheetal; Acharya, Jyoti; Pakalapati, Deepak; Saxena, Vishal; Aiyaz, Mohammed; Orekondy, Harsha B; Mugasimangalam, Raja C; Sirohi, Paramendra; Kochar, Sanjay K; Kochar, Dhanpat K; Das, Ashis

    2014-06-01

    Mechanisms regulating gene expression in malaria parasites are not well understood. Little is known about how the parasite regulates its gene expression during transition from one developmental stage to another and in response to various environmental conditions. Parasites in a diseased host face environments which differ from the static, well adapted in vitro conditions. Parasites thus need to adapt quickly and effectively to these conditions by establishing transcriptional states which are best suited for better survival. With the discovery of natural antisense transcripts (NATs) in this parasite and considering the various proposed mechanisms by which NATs might regulate gene expression, it has been speculated that these might be playing a critical role in gene regulation. We report here the diversity of NATs in this parasite, using isolates taken directly from patients with differing clinical symptoms caused by malaria infection. Using a custom designed strand specific whole genome microarray, a total of 797 NATs targeted against annotated loci have been detected. Out of these, 545 NATs are unique to this study. The majority of NATs were positively correlated with the expression pattern of the sense transcript. However, 96 genes showed a change in sense/antisense ratio on comparison between uncomplicated and complicated disease conditions. The antisense transcripts map to a broad range of biochemical/metabolic pathways, especially pathways pertaining to the central carbon metabolism and stress related pathways. Our data strongly suggests that a large group of NATs detected here are unannotated transcription units antisense to annotated gene models. The results reveal a previously unknown set of NATs that prevails in this parasite, their differential regulation in disease conditions and mapping to functionally well annotated genes. The results detailed here call for studies to deduce the possible mechanism of action of NATs, which would further help in

  14. Isolation of whole esophageal gland cells from plant-parasitic nematodes for transcriptome analyses and effector identification.

    PubMed

    Maier, Tom R; Hewezi, Tarek; Peng, Jiqing; Baum, Thomas J

    2013-01-01

    Esophageal glands of plant-parasitic nematodes are highly specialized cells whose gene expression products include secreted effector proteins, which govern nematode parasitism of host plants. Therefore, elucidating the transcriptomes of esophageal glands with the goal of identifying nematode effectors is a promising avenue to understanding nematode parasitism and its evolutionary origins as well as to devising nematode control strategies. We have developed a method to separate and isolate individual esophageal gland cells from multiple species of plant-parasitic nematodes while preserving RNA quality. We have used such isolated gland cells for transcriptome analysis via high-throughput DNA sequencing. This method relies on the differential histochemical staining of the gland cells after homogenization of phytonematode tissues. Total RNA was extracted from whole gland cells isolated from eight different plant-parasitic nematode species. To validate this approach, the isolated RNA from three plant-parasitic nematode species-Globodera rostochiensis, Pratylenchus penetrans, and Radopholus similis-was amplified, gel purified, and used for 454 sequencing. We obtained 456,801 total reads with an average read length of 409 bp. Sequence analyses revealed the presence of homologs of previously known nematode effectors in these libraries, thus validating our approach. These data provide compelling evidence that this technical advance can be used to relatively easily and expediently discover effector repertoires of plant-parasitic nematodes.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

    Cockroaches are claimed to be mechanical transmitters of disease causing microorganisms such as intestinal parasites, bacteria, fungi, and viruses. This study assessed the potential of the German cockroach Blattella germanica in the mechanical transmission of intestinal parasites of public health importance. A total of 2010 cockroaches were collected from 404 households in Jimma Town, southwestern Ethiopia. All the collected cockroaches were identified to species as B. germanica. The contents of their gut and external body parts were examined for the presence of intestinal parasites. Overall, 152 (75.6%) of the 210 batches were found to harbor at least one species of human intestinal parasite. Ascaris lumbricoides, Trichuris trichiura, Taenia spp, Strongyloides-like parasite, Entamoeba histolytica/dispar/moshkovski, Giardia duodenalis and Balantidium coli were detected from gut contents. Moreover, parasites were also isolated from the external surface in 22 (10.95%) of the batches. There was significant difference in parasite carriage rate of the cockroaches among the study sites (P = 0.013). In conclusion, B. germanica was found to harbor intestinal parasites of public health importance. Hence, awareness on the potential role of cockroaches in the mechanical transmission of human intestinal parasites needs to be created. Moreover, further identification of the Strongyloides-like worm is required using molecular diagnostics. PMID:24649356

  17. Isolation of a laminin-binding protein from the protozoan parasite Leishmania donovani that may mediate cell adhesion.

    PubMed Central

    Ghosh, A; Bandyopadhyay, K; Kole, L; Das, P K

    1999-01-01

    Extracellular matrix (ECM)-binding proteins on the surface of Leishmania are thought to play a crucial role in the onset of leishmaniasis, as these parasites invade mononuclear phagocytes in various organs after migrating through the ECM. In a previous report, we presented several lines of evidence suggesting that Leishmania has a specific receptor for laminin, a major ECM protein, with a Kd in the nanomolar range. Here we describe the identification, purification and biochemical characterization of the Leishmania laminin receptor. When the outer membrane proteins of L. donovani were blotted on to nitrocellulose paper and probed with laminin, a prominent laminin-binding protein of 67 kDa was identified. The purified protein was isolated by a three-step process involving DEAE-cellulose, Con A (concanavalin A)-Sepharose and laminin-Sepharose affinity chromatography and was used to raise a monospecific antibody. The same protein was obtained when parasite membrane extracts were adsorbed to antibody affinity matrix and eluted with glycine. The affinity-purified protein bound to laminin in a detergent-solubilized form as well as after integration into artificial bilayers, and was subsequently characterized as an integral membrane protein. Metaperiodate oxidation and metabolic inhibition of glycosylation studies indicate the binding protein to be glycoprotein in nature and that N-linked oligosaccharides play a part in the interaction of laminin with the binding protein. Surface-labelled parasites attached to microtitre wells coated with laminin and the 67 kDa protein blocked the adhesion to laminin substrate. We propose that the 67 kDa protein is an adhesin involved in the attachment of Leishmania to host tissues. PMID:9895301

  18. Leukocyte profiles for western fence lizards, Sceloporus occidentalis, naturally infected by the malaria parasite Plasmodium mexicanum.

    PubMed

    Motz, Victoria L; Lewis, William D; Vardo-Zalik, Anne M

    2014-10-01

    Plasmodium mexicanum is a malaria parasite that naturally infects the western fence lizard, Sceloporus occidentalis , in northern California. We set out to determine whether lizards naturally infected with this malaria parasite have different leukocyte profiles, indicating an immune response to infection. We used 29 naturally infected western fence lizards paired with uninfected lizards based on sex, snout-to-vent length, tail status, and the presence-absence of ectoparasites such as ticks and mites, as well as the presence-absence of another hemoparasite, Schellackia occidentalis. Complete white blood cell (WBC) counts were conducted on blood smears stained with Giemsa, and the proportion of granulocytes per microliter of blood was estimated using the Avian Leukopet method. The abundance of each WBC class (lymphocytes, monocytes, heterophils, eosinophils, and basophils) in infected and uninfected lizards was compared to determine whether leukocyte densities varied with infection status. We found that the numbers of WBCs and lymphocytes per microliter of blood significantly differed (P < 0.05) between the 2 groups for females but not for males, whereas parasitemia was significantly correlated with lymphocyte counts for males, but not for females. This study supports the theory that infection with P. mexicanum stimulates the lizard's immune response to increase the levels of circulating WBCs, but what effect this has on the biology of the parasite remains unclear.

  19. Rapid natural selection for resistance to an introduced parasite of rainbow trout.

    PubMed

    Miller, Mark P; Vincent, E Richard

    2008-05-01

    Introduced species and infectious diseases both independently pose challenges for the preservation of existing biodiversity. However, native species or disease hosts are by no means 'unarmed' when faced with novel environmental challenges, provided that adequate adaptive genetic variation exists to mount effective evolutionary responses. In this study, we examined the consequences of the recently introduced parasite and causative agent of whirling disease (Myxobolus cerebralis) in a wild rainbow trout (Oncorhynchus mykiss) population from Harrison Lake, Montana (USA). Consistent with the parasite's age-specific effects, juvenile rainbow trout recruitment into Harrison Lake was substantially reduced following parasite detection in 1995. However, experimental data suggest that natural selection has rapidly reduced whirling disease susceptibility within the population over time. The rapid observed temporal change in resistance patterns argues that the standing genetic variation for parasite resistance facilitated this process. Our findings ultimately underscore the importance of preserving genetic diversity to ensure that species of economic importance or of conservation concern have maximal chances for persistence in future changing environments.

  20. Predation and Parasitism Rates on Sentinel and Naturally Occurring Egg Masses of the Squash Bug (Hemiptera: Coreidae) in Maryland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seasonal changes in egg predation and parasitism rates on sentinel and naturally occurring (wild) egg masses of the squash bug, Anasa tristis (DeGeer), were evaluated in squash fields in Maryland from June through September in 2013 and 2014. Rates of egg predation and parasitism were significantly ...

  1. Absence of Wolbachia endobacteria in Sri Lankan isolates of the nematode parasite of animals Setaria digitata.

    PubMed

    Voronin, Denis; Abeykoon, A M L L; Gunawardene, Y I Silva; Dassanayake, Ranil S

    2015-01-30

    Setaria digitata is an animal filarial parasite with natural hosts of cattle and buffaloes that causes mild disease conditions. Infection of non-permissive hosts such as goats, sheep and horses, by this nematode can cause cerebrospinal nematodiasis that leads to lumbar paralysis and the eventual death of the animals and inflicts considerable economic losses on livestock farmers. Wolbachia are obligate mutualistic endosymbionts for some filarial nematodes and are currently being targeted for the control of diseases caused by these parasites. However, little is known about the occurrence of this endosymbiont in the Setariidae family. In this work, worms collected from infected cattle in Sri Lanka were morphologically identified as S. digitata and tested for the presence of Wolbachia by PCR screening using the WSP- and Wolbachia-specific 16S rRNA and multilocus sequence typing primers that were designed to amplify the gatB, coxA, hcpA, ftsZ and fbpA sequences of Wolbachia. The presence of endobacteria in S. digitata was also examined by whole-mount immunofluorescence staining of the parasites and transmission electron microscopic studies. These analyses did not produce evidence of presence of Wolbachia or any other endosymbiotic bacteria in S. digitata, whereas such evidence was found in Brugia malayi, which was used as a positive control in this study.

  2. Parasites: Water

    MedlinePlus

    ... Tropical Diseases Laboratory Diagnostic Assistance [DPDx] 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 ...

  3. Interactions Between Trypanosoma cruzi the Chagas Disease Parasite and Naturally Infected Wild Mepraia Vectors of Chile.

    PubMed

    Campos-Soto, Ricardo; Ortiz, Sylvia; Cordova, Ivan; Bruneau, Nicole; Botto-Mahan, Carezza; Solari, Aldo

    2016-03-01

    Chagas disease, which ranks among the world's most neglected diseases, is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. Mepraia species are the wild vectors of this parasite in Chile. Host-parasite interactions can occur at several levels, such as co-speciation and ecological host fitting, among others. Thus, we are exploring the interactions between T. cruzi circulating in naturally infected Mepraia species in all areas endemic of Chile. We evaluated T. cruzi infection rates of 27 different haplotypes of the wild Mepraia species and identified their parasite genotypes using minicircle PCR amplification and hybridization tests with genotype-specific DNA probes. Infection rates were lower in northern Chile where Mepraia gajardoi circulates (10-35%); in central Chile, Mepraia spinolai is most abundant, and infection rates varied in space and time (0-55%). T. cruzi discrete typing units (DTUs) TcI, TcII, TcV, and Tc VI were detected. Mixed infections with two or more DTUs are frequently found in highly infected insects. T. cruzi DTUs have distinct, but not exclusive, ecological and epidemiological associations with their hosts. T. cruzi infection rates of M. spinolai were higher than in M. gajardoi, but the presence of mixed infection with more than one T. cruzi DTU was the same. The same T. cruzi DTUs (TcI, TcII, TcV, and TcVI) were found circulating in both vector species, even though TcI was not equally distributed. These results suggest that T. cruzi DTUs are not associated with any of the two genetically related vector species nor with the geographic area. The T. cruzi vectors interactions are discussed in terms of old and recent events. By exploring T. cruzi DTUs present in Mepraia haplotypes and species from northern to central Chile, we open the analysis on these invertebrate host-parasite interactions.

  4. Major histocompatibility complex (MHC) heterozygote superiority to natural multi-parasite infections in the water vole (Arvicola terrestris).

    PubMed

    Oliver, M K; Telfer, S; Piertney, S B

    2009-03-22

    The fundamental role of the major histocompatibility complex (MHC) in immune recognition has led to a general consensus that the characteristically high levels of functional polymorphism at MHC genes is maintained by balancing selection operating through host-parasite coevolution. However, the actual mechanism by which selection operates is unclear. Two hypotheses have been proposed: overdominance (or heterozygote superiority) and negative frequency-dependent selection. Evidence for these hypotheses was evaluated by examining MHC-parasite relationships in an island population of water voles (Arvicola terrestris). Generalized linear mixed models were used to examine whether individual variation at an MHC class II DRB locus explained variation in the individual burdens of five different parasites. MHC genotype explained a significant amount of variation in the burden of gamasid mites, fleas (Megabothris walkeri) and nymphs of sheep ticks (Ixodes ricinus). Additionally, MHC heterozygotes were simultaneously co-infected by fewer parasite types than homozygotes. In each case where an MHC-dependent effect on parasite burden was resolved, the heterozygote genotype was associated with fewer parasites, and the heterozygote outperformed each homozygote in two of three cases, suggesting an overall superiority against parasitism for MHC heterozygote genotypes. This is the first demonstration of MHC heterozygote superiority against multiple parasites in a natural population, a mechanism that could help maintain high levels of functional MHC genetic diversity in natural populations.

  5. Major histocompatibility complex (MHC) heterozygote superiority to natural multi-parasite infections in the water vole (Arvicola terrestris)

    PubMed Central

    Oliver, M.K.; Telfer, S.; Piertney, S.B.

    2008-01-01

    The fundamental role of the major histocompatibility complex (MHC) in immune recognition has led to a general consensus that the characteristically high levels of functional polymorphism at MHC genes is maintained by balancing selection operating through host–parasite coevolution. However, the actual mechanism by which selection operates is unclear. Two hypotheses have been proposed: overdominance (or heterozygote superiority) and negative frequency-dependent selection. Evidence for these hypotheses was evaluated by examining MHC–parasite relationships in an island population of water voles (Arvicola terrestris). Generalized linear mixed models were used to examine whether individual variation at an MHC class II DRB locus explained variation in the individual burdens of five different parasites. MHC genotype explained a significant amount of variation in the burden of gamasid mites, fleas (Megabothris walkeri) and nymphs of sheep ticks (Ixodes ricinus). Additionally, MHC heterozygotes were simultaneously co-infected by fewer parasite types than homozygotes. In each case where an MHC-dependent effect on parasite burden was resolved, the heterozygote genotype was associated with fewer parasites, and the heterozygote outperformed each homozygote in two of three cases, suggesting an overall superiority against parasitism for MHC heterozygote genotypes. This is the first demonstration of MHC heterozygote superiority against multiple parasites in a natural population, a mechanism that could help maintain high levels of functional MHC genetic diversity in natural populations. PMID:19129114

  6. Rapid natural selection for resistance to an introduced parasite of rainbow trout

    PubMed Central

    Miller, Mark P; Vincent, E Richard

    2008-01-01

    Introduced species and infectious diseases both independently pose challenges for the preservation of existing biodiversity. However, native species or disease hosts are by no means ‘unarmed’ when faced with novel environmental challenges, provided that adequate adaptive genetic variation exists to mount effective evolutionary responses. In this study, we examined the consequences of the recently introduced parasite and causative agent of whirling disease (Myxobolus cerebralis) in a wild rainbow trout (Oncorhynchus mykiss) population from Harrison Lake, Montana (USA). Consistent with the parasite’s age-specific effects, juvenile rainbow trout recruitment into Harrison Lake was substantially reduced following parasite detection in 1995. However, experimental data suggest that natural selection has rapidly reduced whirling disease susceptibility within the population over time. The rapid observed temporal change in resistance patterns argues that the standing genetic variation for parasite resistance facilitated this process. Our findings ultimately underscore the importance of preserving genetic diversity to ensure that species of economic importance or of conservation concern have maximal chances for persistence in future changing environments. PMID:25567635

  7. Leishmania chagasi naturally resistant to nitric oxide isolated from humans and dogs with visceral leishmaniasis in Brazil.

    PubMed

    Santos, P L; Costa, R V; Braz, J M; Santos, L F V C; Batista, A C; Vasconcelos, C R O; Rangel, M R; Ribeiro de Jesus, A; de Moura, T R; Leopoldo, P T G; Almeida, R P

    2012-06-30

    Nitric oxide (NO) plays an important role as a leishmanicidal agent in murine macrophages. NO resistant Escherichia coli and Mycobacterium tuberculosis have been associated with poor outcomes of their resulting diseases. NO resistant Leishmania braziliensis has also been identified and exacerbates the clinical course of human leishmaniasis. We report, for the first time, natural resistance of Leishmania chagasi promastigotes to NO. These parasites were isolated from humans and dogs with visceral leishmaniasis. We also demonstrate that this resistance profile was associated with a greater survival capacity and a greater parasite burden in murine macrophages, independent of activation and after activation by IFN-γ and LPS.

  8. Mycoplasma hominis in Cuban Trichomonas vaginalis isolates: association with parasite genetic polymorphism.

    PubMed

    Fraga, Jorge; Rodríguez, Nadia; Fernández, Carmen; Mondeja, Brian; Sariego, Idalia; Fernández-Calienes, Aymé; Rojas, Lazara

    2012-07-01

    Trichomonas vaginalis can be naturally infected with intracellular Mycoplasma hominis. This bacterial infection may have implications for trichomonal virulence and disease pathogenesis. The objective of the study was to report the presence of M. hominis in Cuban T. vaginalis isolates and to describe the association between the phenotype M. hominis infected with RAPD genetic polymorphism of T. vaginalis. The Random Amplified Polymorphic DNA (RAPD) technique was used to determine genetic differences among 40 isolates of T. vaginalis using a panel of 30 random primers and these genetic data were correlated with the infection of isolates with M. hominis. The trees drawn based on RAPD data showed no relations with metronidazole susceptibility and significantly association with the presence of M. hominis (P=0.043), which demonstrates the existence of concordance between the genetic relatedness and the presence of M. hominis in T. vaginalis isolates. This result could point to a predisposition of T. vaginalis for the bacterial enters and/or survival.

  9. The nature of isolated T Tauri stars

    NASA Astrophysics Data System (ADS)

    Hoff, Wilhelm; Henning, Thomas; Pfau, Werner

    1998-08-01

    We present the results of a search for young stellar objects around the two isolated T Tauri stars (TTSs) TW Hya and CoD-29degr 8887. From the spectroscopic properties of these two objects, it is obvious that they are T Tauri stars, although they are not associated with a star-forming region as it is the case for most of the known TTSs. Especially TW Hya is the only classical TTS that is not located in a dark cloud with star formation activity. The same is true for the weak-line T Tauri star CoD-29degr 8887. We searched for pre-main sequence stars using ROSAT PSPC observations pointing at our two main targets. With a sophisticated search strategy we could identify 107 X-ray sources in our fields. For the 37 stellar-like optical counterparts we did spectroscopic follow-up observations. These show that within the viewing field of ROSAT there are no other X-ray emitting young stellar objects around TW Hya and CoD-29degr 8887. For the isolated TTSs TW Hya and HD 98800 Hipparcos parallax measurements are available locating them at distances of 56 and 46pc, respectively. This means that they are the closest TTSs with circumstellar dusty disks known today. The space velocities of these two objects are 3-5km/sec. From their position in the HR diagram, we obtained an age of about 10(7) years. Hence, we conclude that these two objects travelled not far away from their original birthplace and their parental molecular cloud dispersed meanwhile. This is the solution why these T Tauri stars appear to be isolated. Based on observations obtained at the European Southern Observatory, La Silla, Chile

  10. Naturally-induced endocrine disruption by the parasite Ligula intestinalis (Cestoda) in roach (Rutilus rutilus).

    PubMed

    Trubiroha, Achim; Kroupova, Hana; Wuertz, Sven; Frank, Sabrina N; Sures, Bernd; Kloas, Werner

    2010-04-01

    Fish represent the most frequently used vertebrate class for the investigation of endocrine disruption (ED) in wildlife. However, field studies are complicated by exposure scenarios involving a variety of anthropogenic and natural influences interfering with the endocrine system. One natural aspect rarely considered in ecotoxicological studies is how parasites modulate host physiology. Therefore, investigations were carried out to characterise the impacts of the parasitic tapeworm Ligula intestinalis on plasma sex steroid levels and expression of key genes associated with the reproduction in roach (Rutilus rutilus), a sentinel species for wildlife ED research. Parasitisation by L. intestinalis suppressed gonadal development in both genders of roach and analysis of plasma sex steroids revealed substantially lower levels of 17beta-oestradiol (E2) and 11-ketotestosterone (11-KT) in infected females as well as E2, 11-KT, and testosterone in infected males. Consistently, in both, infected females and males, expression of the oestrogen dependent genes such as vitellogenin and brain-type aromatase in liver and brain was reduced. Furthermore, parasitisation differentially modulated mRNA expression of the oestrogen and androgen receptors in brain and liver. Most prominently, liver expression of oestrogen receptor 1 was reduced in infected females but not in males, whereas expression of oestrogen receptor 2a was up-regulated in both genders. Further, insulin-like growth factor 1 mRNA in the liver was increased in infected females but not in males. Despite severe impacts on plasma sex steroids and pituitary gonadotropin expression, brain mRNA levels of gonadotropin-releasing hormone (GnRH) precursors encoding GnRH2 and GnRH3 were not affected by L. intestinalis-infection. In summary, the present results provide basic knowledge of the endocrine system in L. intestinalis-infected roach and clearly demonstrate that parasites can cause ED in fish.

  11. The effect of birdsfoot trefoil (Lotus corniculatus) and chicory (Cichorium intybus) on parasite intensities and performance of lambs naturally infected with helminth parasites.

    PubMed

    Marley, C L; Cook, R; Keatinge, R; Barrett, J; Lampkin, N H

    2003-02-28

    Conventionally, farmers rely upon the routine use of anthelmintics to control helminth parasites and their use has proved highly cost-effective. However, several factors, including the emergence of helminths resistant to pharmaceutical anthelmintics, are forcing farmers to seek alternative approaches to parasite control. Studies in New Zealand have shown that some alternative forages may reduce parasitic infestation in sheep. In the current study, it was found that under UK environmental conditions lambs with naturally acquired helminth infections grazing chicory (Cichorium intybus) and birdsfoot trefoil (Lotus corniculatus) had fewer helminth parasites than sheep grazing ryegrass/white clover (Lolium perenne/Trifolium repens). Twelve pure-bred Lleyn male lambs grazed replicated 0.5ha plots of birdsfoot trefoil, chicory or ryegrass/white clover for 5 weeks. Liveweight and faecal egg counts (FECs) were determined weekly and eight lambs per forage were slaughtered at the end of the trial to determine total helminth intensities. Lambs grazing birdsfoot trefoil had a lower FEC on day 7 (P<0.05) and fewer total adult helminths than those grazing the other forages on day 35 (P<0.01). Lambs grazing chicory did not have significantly lower FEC than lambs grazing other forages but these lambs were found to have fewer total adult abomasal helminths than lambs grazing ryegrass/white clover (P<0.001). As the performance of grazing lambs is inversely correlated with the intensity of helminth parasites, these alternative forages could be used to improve the liveweight gain of lambs produced in the UK. Overall, the results support the contention that alternative forages could have a positive role in the control of helminth parasites in sheep, subject to successful agronomic development and integration of these forages into whole farm systems.

  12. Preservation of Wild Isolates of Human Malaria Parasites in Wet Ice and Adaptation Efficacy to In Vitro Culture

    PubMed Central

    Tantular, Indah S.; Pusarawati, Suhintam; Khin, Lin; Kanbe, Toshio; Kimura, Masatsugu; Kido, Yasutoshi; Kawamoto, Fumihiko

    2012-01-01

    Wild isolates of malaria parasites were preserved in wet ice for 2–12 days and cultivated by a candle jar method. In four isolates of Plasmodium falciparum collected from Myanmar and preserved for 12 days, all failed to grow. In 31 isolates preserved for 5–10 days, nine were transformed to young gametocytes, but 22 isolates grew well. From Ranong, Thailand, nine isolates preserved for 7 days were examined, and six grew well. On the other hand, all of the 59 isolates collected from eastern Indonesian islands failed to establish as culture-adapted isolates, even most of them were preserved only for 2–3 days: 10 isolates stopped to grow, and 49 isolates were transformed to sexual stages by Day 10. These results indicated that a great difference in adaptation to in vitro culture may exist between wild isolates distributed in continental Southeast Asia and in eastern Indonesia and that gametocytogenesis might be easily switched on in Indonesian isolates. In wild isolates of P. vivax, P. malariae and P. ovale preserved for 2–9 days, ring forms or young trophozoites survived, but adaptation to in vitro culture failed. These results indicate that wild isolates can be preserved in wet ice for 9–10 days. PMID:23097618

  13. Parasite Manipulation of Its Host's Physiological Reaction to Acute Stress: Experimental Results from a Natural Beetle-Nematode System.

    PubMed

    Davis, Andrew K; Vasquez, David; LeFeuvre, Jake; Sims, Stuart; Craft, Meghan; Vizurraga, Anna

    All animals, whether vertebrate or invertebrate, must be capable of reacting to acute stressors, such as escaping from predators, and most do so with a suite of transient physiological changes that temporarily enhance survival. Some of these changes include mobilization of immune cells and increased cardiac output. A small but growing number of studies have begun to show that certain parasites appear capable of modifying such responses. We addressed this topic using a natural host and parasite system, that is, a nematode (Chondronema passali) that parasitizes horned passalus beetles, Odontotaenius disjunctus (family Passalidae), of the eastern United States. With a series of experiments, we sought to determine whether this parasite affects (1) the immune reaction to stress, (2) the output of stress-induced alarm calls, or (3) the increase in heart rate that occurs in response to acute stressors, with the stressors being mechanical or thermal. Results showed that hemocyte density increased after both stressors in nonparasitized beetles but did not increase in parasitized beetles. While mobilization of immune cells would enhance host immunity during stress, this would also be damaging to the nematode, so this scenario appears to benefit the parasite. We found no evidence that the nematode suppresses the overall reaction to stress (or prevents stress from occurring), since parasitized beetles did not differ from nonparasitized ones in alarm call rates or in heart beat frequency after exposure to mechanical stressors. Suppression of the host's normal immune reaction to stressful stimuli could translate to delayed or even reduced wound healing or pathogen resistance during these events. This project is a rare demonstration of parasite manipulation of host immune response to acute stress and should stimulate further investigations into the interactive nature of stress and parasites.

  14. hTERT-immortalized ovine microglia propagate natural scrapie isolates.

    PubMed

    Muñoz-Gutiérrez, Juan F; Schneider, David A; Baszler, Timothy V; Greenlee, Justin J; Nicholson, Eric M; Stanton, James B

    2015-02-16

    Ex vivo propagation of natural prion isolates (i.e., propagated solely in the natural host) is crucial for the characterization and study of transmissible spongiform encephalopathies (TSEs). Several well-established, prion-permissive cell culture systems are available; however, only a few cell lines are permissive to natural prion isolates and these cells are not pathophysiologically relevant (e.g., renal epithelium and fibroblast-like cells). Therefore, a pathophysiologically relevant cell line derived from a natural TSE host could be used for propagation of natural prion isolates. In this study, ovine brain macrophages (microglia) were immortalized by transfection with the human telomerase reverse transcriptase (hTERT) gene to identify cell lines (hTERT-microglia) permissive to natural scrapie prion isolates. Following transfection, hTERT-microglia were passaged up to 100 times and their lifespan was significantly longer compared to parental cells (Fisher's exact test, P<0.001). Multiple sublines were permissive to cell culture-adapted prions; two sublines were also permissive to natural scrapie isolates (i.e., derived from brain homogenates of sheep infected with scrapie). Prion infectivity and partial protease resistance of the prion protein were maintained in hTERT-microglia. Comparisons between scrapie-permissive and non-permissive hTERT-microglia sublines revealed that overall quantity of the normal cellular prion protein was not associated with prion permissiveness. The use of hTERT-microglia in future TSE studies may be more germane to the characterization of the cellular and subcellular pathophysiology of natural scrapie prion isolates and to investigate host-specific factors involved in prion replication.

  15. Host-seeking stimulant for parasite of corn earworm: isolation, identification, and synthesis.

    PubMed

    Jones, R L; Lewis, W J; Bowman, M C; Beroza, M; Bierl, B A

    1971-08-27

    13-Methylhentriacontane has been identified in the feces and larvae of the corn earworm, Heliothis zea (Boddie), as the major constituent that triggers the short-range host-seeking response of the parasite Microplitis croceipes (Cresson). This chemical, the first found that mediates the complex host-parasite relation, could upgrade present efforts to use parasites for insect control. Bioassay of closely related compounds indicated that the structural requirements for activity are remarkably specific.

  16. Isolation and Genotyping of Acanthamoeba spp. as Neglected Parasites in North of Iran

    PubMed Central

    Shokri, Azar; Sarvi, Shahabeddin; Daryani, Ahmad; Sharif, Mehdi

    2016-01-01

    Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals. PMID:27658596

  17. Isolation and Genotyping of Acanthamoeba spp. as Neglected Parasites in North of Iran.

    PubMed

    Shokri, Azar; Sarvi, Shahabeddin; Daryani, Ahmad; Sharif, Mehdi

    2016-08-01

    Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.

  18. Specific isolation of RNA from the grape powdery mildew pathogen Erysiphe necator, an epiphytic, obligate parasite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RNA expression profiling of obligately parasitic plant microbes is hampered by the requisite interaction of host and parasite. For superficial pathogens like grape powdery mildew as well as for epiphytic saprophytes, growth along the outside surface of the plant allows separation from the host and ...

  19. Genetic polymorphism and natural selection in the malaria parasite Plasmodium falciparum.

    PubMed Central

    Escalante, A A; Lal, A A; Ayala, F J

    1998-01-01

    We have studied the genetic polymorphism at 10 Plasmodium falciparum loci that are considered potential targets for specific antimalarial vaccines. The polymorphism is unevenly distributed among the loci; loci encoding proteins expressed on the surface of the sporozoite or the merozoite (AMA-1, CSP, LSA-1, MSP-1, MSP-2, and MSP-3) are more polymorphic than those expressed during the sexual stages or inside the parasite (EBA-175, Pfs25, PF48/45, and RAP-1). Comparison of synonymous and nonsynonymous substitutions indicates that natural selection may account for the polymorphism observed at seven of the 10 loci studied. This inference depends on the assumption that synonymous substitutions are neutral, which we test by analyzing codon bias and G+C content in a set of 92 gene loci. We find evidence for an overall trend towards increasing A+T richness, but no evidence for mutation bias. Although the neutrality of synonymous substitutions is not definitely established, this trend towards an A+T rich genome cannot explain the accumulation of substitutions at least in the case of four genes (AMA-1, CSP, LSA-1, and PF48/45) because the Gleft and right arrow C transversions are more frequent than expected. Moreover, the Tajima test manifests positive natural selection for the MSP-1 and, less strongly, MSP-3 polymorphisms; the McDonald-Kreitman test manifests natural selection at LSA-1 and PF48/45. We conclude that there is definite evidence for positive natural selection in the genes encoding AMA-1, CSP, LSA-1, MSP-1, and Pfs48/45. For four other loci, EBA-175, MSP-2, MSP-3, and RAP-1, the evidence is limited. No evidence for natural selection is found for Pfs25. PMID:9584096

  20. Natural infection of Algerian hedgehog, Atelerix algirus (Lereboullet 1842) with Leishmania parasites in Tunisia.

    PubMed

    Chemkhi, Jomaa; Souguir, Hejer; Ali, Insaf Bel Hadj; Driss, Mehdi; Guizani, Ikram; Guerbouj, Souheila

    2015-10-01

    demonstrates, for the first time in Tunisia, natural infection of hedgehog animals (Atelerix algirus) by the Leishmania parasites species L. major and L. infantum. L. major is also detected for the first time in wild animals captured in the North Western part of the country; likewise for the co-infection of these animals by the 2 Leishmania species. This mammal could play a potential reservoir role in epidemiology of SCL or ZCL and could contribute to emergence or extension of ZCL in the studied region.

  1. The natural resistance-associated macrophage protein from the protozoan parasite Perkinsus marinus mediates iron uptake.

    PubMed

    Lin, Zhuoer; Fernández-Robledo, José-Antonio; Cellier, Mathieu F M; Vasta, Gerardo R

    2011-07-26

    Microbial pathogens succeed in acquiring essential metals such as iron and manganese despite their limited availability because of the host's immune response. The eukaryotic natural resistance-associated macrophage proteins mediate uptake of divalent metals and, during infection, may compete directly for metal acquisition with the pathogens' transporters. In this study, we characterize the Nramp gene family of Perkinsus marinus, an intracellular parasite of the eastern oyster, and through yeast complementation, we demonstrate for the first time for a protozoan parasite that Nramp imports environmental Fe. Three PmNramp isogenes differ in their exon-intron structures and encode transcripts that display a trans splicing leader at the 5' end. The protein sequences share conserved properties predicted for the Nramp/Solute carrier 11 (Slc11) family, such as 12-transmembrane segment (TMS) topology (N- and C-termini cytoplasmic) and preferential conservation of four TMS predicted to form a pseudosymmetric proton/metal symport pathway. Yeast fet3fet4 mutant complementation assays showed iron transport activity for PmNramp1 and a fusion chimera of the PmNramp3 hydrophobic core and PmNramp1 N- and C-termini. PmNramp1 site-directed mutagenesis demonstrated that Slc11 invariant and predicted pseudosymmetric motifs (TMS1 Asp-Pro-Gly and TMS6 Met-Pro-His) are key for transport function. PmNramp1 TMS1 mutants D76E, G78A, and D76E/G78A prevented membrane protein expression, while TMS6 M250A, H252Y, and M250A/H252Y specifically abrogated Fe uptake; the TMS6 H252Y mutation also correlates with divergence from Nramp specificity for divalent metals.

  2. Isolation of cDNA clones for differentially expressed genes of the human parasite Schistosoma mansoni.

    PubMed Central

    Davis, A H; Blanton, R; Rottman, F; Maurer, R; Mahmoud, A

    1986-01-01

    Little is known about the mechanisms that control transformations during the life cycle of Schistosoma mansoni. To enable isolation of DNA sequences encoding developmentally regulated antigens a cDNA expression library in the vector lambda gt11 amp3 was constructed from adult mRNA and immunologically screened with sera from infected individuals. We report here on the properties of three recombinant clones that derive from developmentally regulated genes. Clone 10-3 encoded a beta-galactosidase fusion protein present in high abundance in infected Escherichia coli. Clones 7-2 and 8-2 also produced immunologically recognized proteins; however, the peptides did not appear to be beta-galactosidase fusion proteins. The expression of mRNAs hybridizing to these cDNAs was examined in the different stages of the parasite life cycle. Messenger RNA corresponding to clone 10-3, approximately equal to 1000 bases in length, was present in higher abundance in male worms than in females but was not detected in schistosome eggs. A 900-base mRNA hybridizing to clone 7-2 was observed in adult worms and eggs. Both clone 10-3 and clone 7-2 hybridized to smaller mRNAs in cercariae and freshly transformed schistosomula than in adult worms. Clone 8-2 contained tandem cDNA inserts. One cDNA hybridized to a 1700-base mRNA present in all stages, while the second hybridized to an 800-base mRNA specific to adult female worms. Images PMID:3461448

  3. Culturable rare Actinomycetes: diversity, isolation and marine natural product discovery.

    PubMed

    Subramani, Ramesh; Aalbersberg, William

    2013-11-01

    Rare Actinomycetes from underexplored marine environments are targeted in drug discovery studies due to the Actinomycetes' potentially huge resource of structurally diverse natural products with unusual biological activity. Of all marine bacteria, 10 % are Actinomycetes, which have proven an outstanding and fascinating resource for new and potent bioactive molecules. Past and present efforts in the isolation of rare Actinomycetes from underexplored diverse natural habitats have resulted in the isolation of about 220 rare Actinomycete genera of which more than 50 taxa have been reported to be the producers of 2,500 bioactive compounds. That amount represents greater than 25 % of the total Actinomycetes metabolites, demonstrating that selective isolation methods are being developed and extensively applied. Due to the high rediscovery rate of known compounds from Actinomycetes, a renewed interest in the development of new antimicrobial agents from rare and novel Actinomycetes is urgently required to combat the increasing number of multidrug-resistant human pathogens. To facilitate that discovery, this review updates all selective isolation media including pretreatment and enrichment methods for the isolation of marine rare Actinomycetes. In addition, this review demonstrates that discovering new compounds with novel scaffolds can be increased by intensive efforts in isolating and screening rare marine genera of Actinomycetes. Between 2007 and mid-2013, 80 new rare Actinomycete species were reported from marine habitats. They belong to 23 rare families, of which three are novel, and 20 novel genera. Of them, the family Micromonosporaceae is dominant as a producer of promising chemical diversity.

  4. Natural parasitism of Metaparasitylenchus hypothenemi (Tylenchida: Allantonematidae) on the coffee berry borer, Hypothenemus hampei, in Chiapas, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metaparasitylenchus hypothenemi is a relatively new nematode species found attacking the coffee berry borer, Hypothenemus hampei, in Mexico. We assessed the natural parasitism and distribution of this nematode in 20 coffee plantations in the state of Chiapas, at elevations ranging from 223 to 1458 m...

  5. The cause of parasitic infection in natural populations of Daphnia (Crustacea: Cladocera): the role of host genetics.

    PubMed Central

    Little, T J; Ebert, D

    2000-01-01

    Disease patterns in nature may be determined by genetic variation for resistance or by factors, genetic or environmental, which influence the host-parasite encounter rate. Elucidating the cause of natural infection patterns has been a major pursuit of parasitologists, but it also matters for evolutionary biologists because host resistance genes must influence the expression of disease if parasite-mediated selection is to occur. We used a model system in order to disentangle the strict genetic component from other causes of infection in the wild. Using the crustacean Daphnia magna and its sterilizing bacterial parasite Pasteuria ramosa, we tested whether genetic variation for resistance, as determined under controlled conditions, accounted for the distribution of infections within natural populations. Specifically, we compared whether the clonally produced great-granddaughters of those individuals that were infected in field samples (but were subsequently 'cured' with antibiotics) were more susceptible than were the great-granddaughters of those individuals that were healthy in field samples. High doses of parasite spores led to increased infection in all four study populations, indicating the importance of encounter rate. Host genetics appeared to be irrelevant to natural infection patterns in one population. However, in three other populations hosts that were healthy in the field had greater genetic-based resistance than hosts that were infected in the field, unambiguously showing the effect of host genetic factors on the expression of disease in the wild. PMID:11416906

  6. Anti-cancer natural products isolated from chinese medicinal herbs

    PubMed Central

    2011-01-01

    In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and in vivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg3), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed. PMID:21777476

  7. Targeted gene expression profiling in Leishmania braziliensis and Leishmania guyanensis parasites isolated from Brazilian patients with different antimonial treatment outcomes.

    PubMed

    Torres, Davi Coe; Adaui, Vanessa; Ribeiro-Alves, Marcelo; Romero, Gustavo A S; Arévalo, Jorge; Cupolillo, Elisa; Dujardin, Jean-Claude

    2010-08-01

    In Brazil, cutaneous leishmaniasis represents a serious public health problem, and chemotherapy is an important element of the clinical management of this disease. However, treatment efficacy is variable, a phenomenon that might be due to host and parasite (e.g., drug resistance) factors. To better understand the possible contribution of parasite factors to this phenomenon, we characterised 12 Leishmania braziliensis (LB) and 25 Leishmania guyanensis (LG) isolates collected from patients experiencing different antimonial treatment outcomes. For each isolate, promastigote cultures were grown in duplicate and were harvested at the late-log and stationary phases of growth. The RNA expression profiles of six genes encoding proteins with roles in antimony metabolism (AQP1, MRPA, GSH1, GSH2, TRYR and TDR1) were assessed by means of real-time quantitative PCR. Molecular data were compared to the clinical phenotypes. Within LB, we did not find statistically significant differences in the expression levels of the examined genes among isolates from patients with different treatment outcomes. In LG, GSH1 (encoding gamma-glutamylcysteine synthetase, gamma-GCS) was overexpressed in therapeutic failure isolates regardless of the growth curve phase. This finding reveals the predictive potential of promastigote expression curves for the prognosis of cutaneous leishmaniasis caused by LG in Brazil.

  8. Isolation and 18S ribosomal DNA gene sequences of Marteilioides chungmuensis (Paramyxea), an ovarian parasite of the Pacific oyster Crassostrea gigas.

    PubMed

    Itoh, Naoki; Oda, Tadashi; Yoshinaga, Tomoyoshi; Ogawa, Kazuo

    2003-03-31

    To develop sensitive detection techniques with the aim of elucidating the life cycle of Marteilioides chungmuensis, an intracellular paramyxean infecting the ovary of the Pacific oyster Crassostrea gigas, we isolated the parasite at the sporont stage from infected oysters using a freeze-thaw procedure at -20 degrees C and differential centrifugations in discontinuous sucrose and Percoll gradients. DNA was extracted from the isolated sporonts, and a PCR amplicon of 18S small subunit ribosomal RNA gene DNA was partially sequenced. In situ hybridization using 3 parasite-specific probes designed from the obtained sequence successfully detected parasite cells in infected oysters, and confirmed that the sequenced DNA was derived from M. chungmuensis.

  9. A host-parasite list of the haematozoa of domestic poultry in sub-Saharan Africa and the isolation of Plasmodium durae Herman from turkeys and francolins in South Africa.

    PubMed

    Huchzermeyer, F W

    1993-03-01

    An annotated host-parasite list of the blood parasites of domestic poultry in sub-Saharan Africa is presented. This list contains the haematozoa found in domestic waterfowl (ducks, geese and muscovies) and phasianids (turkey, fowl and peafowl). In South Africa Plasmodium durae was isolated from 4 out of 8 backyard turkeys, from 3 out of 26 Swainson's francolins and from 1 redwing francolin, but not from 20 helmeted guineafowls and 9 greywing francolins. This points at Swainson's and redwing francolins as being the main natural hosts of P. durae in South Africa. The increase in the period of prepatency after intramuscular subinoculation as compared with the intravenous route was found to correspond to that of a 1,000 fold dilution of an intravenous inoculum of parasitized blood. This delay was not due to an intervening cycle of exoerythrocytic schizogony, but to large numbers of the injected erythrocytes apparently not finding their way into the circulation of the new host.

  10. [Impact of effect of natural disasters on the circulation of causative agents of parasitic diseases].

    PubMed

    Vaserin, Iu I; Khromenkova, E P; Dimidova, L L; Tverdokhlebova, T I; Nagornyĭ, S A; Prokopova, L V; Dumbadze, O S; Murashov, N E; Butaev, T M; Agirov, A Kh; Osmolovskiĭ, S V; Papatsenko, L B; Soldatova, M V

    2005-01-01

    The southern region is marked by a high incidence of parasitic diseases and a significant contamination of environmental objects with the eggs and cysts of their pathogens. Background examinations revealed the greatest soil contamination with helminthic eggs in the Temryuksky District of the Krasnodar Territory and in the towns of Vladikavkaz and Digora of the Republic of North Ossetia (Alania). The least contamination was found in Rostov-on-Don and the towns of the south-western area of the Krasnodar Territory. The eggs of Toxocara and astamination. There is an increase in the proportion of soil positive tests from 26.6 to 50.0, with the high (up to 82.0-100.0%) viability of eggs and a rise in the intensive index of their content per kg of soil (from 2.7 to 4.7-11.0). Toxocara eggs were mainly detected. The established high proportion of seropositive persons (10.7-18.0%) among the local population is an additional verification of the wide circulation of Toxocara eggs in nature. By the helminthic egg contamination index, the soils of localities of the south of Russia are qualified as those of moderate epidemic hazard. The floods accompanied by the increased helminthological contamination of the upper soil layer may lead to a higher human risk for contamination with helminthic diseases.

  11. Parasite load in the blood and skin of dogs naturally infected by Leishmania infantum is correlated with their capacity to infect sand fly vectors.

    PubMed

    Borja, Lairton Souza; Sousa, Orlando Marcos Farias de; Solcà, Manuela da Silva; Bastos, Leila Andrade; Bordoni, Marcelo; Magalhães, Jairo Torres; Larangeira, Daniela Farias; Barrouin-Melo, Stella Maria; Fraga, Deborah Bittencourt Mothé; Veras, Patrícia Sampaio Tavares

    2016-10-15

    The sand fly Lutzomyia longipalpis is primarily responsible for the transmission of visceral leishmaniasis (VL) in the New World, and dogs are considered to be the main urban reservoir of this disease. In order to improve the efficacy of control measures, it is essential to assess the transmission capacity of Leishmania infantum to the sand fly vector by naturally infected dogs. The present study investigated the existence of correlations between canine clinical presentation and the intensity of parasite load in the blood, skin and spleen of naturally infected dogs. In addition, we also attempted to establish correlations between the intensity of parasite load in canine tissue and the parasite load detected in sandflies five days after feeding on naturally infected dogs. A total of 23 dogs were examined and classified according to clinical manifestation of canine VL. Blood samples, splenic aspirate and skin biopsies were collected and parasite DNA was quantified by qPCR. Canine capacity to infect Lu. longipalpis with parasites was evaluated by xenodiagnosis and parasite loads were measured five days after feeding. No significant differences were observed with respect to canine clinical manifestation and the parasite loads detected in the blood, skin and spleen samples obtained from naturally infected dogs. Regardless of clinical canine visceral leishmaniasis (CVL) presentation and the degree of parasite burden, almost half of the dogs successfully infected sandflies with parasites, albeit to a low number of sandflies with correspondingly low parasite loads. Parasite loads in both canine blood and skin were shown to be positively correlated with the canine infectiousness to the sand fly vector, and positive correlations were also observed with respect to these tissues and the sand fly infection rate, as well as the parasite load detected in sandflies following xenodiagnosis. In conclusion, this indicates that parasite loads in both blood and skin can function as

  12. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites.

    PubMed

    Devoe, Neil C; Corbett, Ian J; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  13. Differential Evolutionary Selection and Natural Evolvability Observed in ALT Proteins of Human Filarial Parasites

    PubMed Central

    Devoe, Neil C.; Corbett, Ian J.; Barker, Linsey; Chang, Robert; Gudis, Polyxeni; Mullen, Nathan; Perez, Kailey; Raposo, Hugo; Scholz, John; May, Meghan

    2016-01-01

    The abundant larval transcript (ALT-2) protein is present in all members of the Filarioidea, and has been reported as a potential candidate antigen for a subunit vaccine against lymphatic filariasis. To assess the potential for vaccine escape or heterologous protection, we examined the evolutionary selection acting on ALT-2. The ratios of nonsynonymous (K(a)) to synonymous (K(s)) mutation frequencies (ω) were calculated for the alt-2 genes of the lymphatic filariasis agents Brugia malayi and Wuchereria bancrofti and the agents of river blindness and African eyeworm disease Onchocerca volvulus and Loa loa. Two distinct Bayesian models of sequence evolution showed that ALT-2 of W. bancrofti and L. loa were under significant (P<0.05; P < 0.001) diversifying selection, while ALT-2 of B. malayi and O. volvulus were under neutral to stabilizing selection. Diversifying selection as measured by ω values was notably strongest on the region of ALT-2 encoding the signal peptide of L. loa and was elevated in the variable acidic domain of L. loa and W. bancrofti. Phylogenetic analysis indicated that the ALT-2 consensus sequences formed three clades: the first consisting of B. malayi, the second consisting of W. bancrofti, and the third containing both O. volvulus and L. loa. ALT-2 selection was therefore not predictable by phylogeny or pathology, as the two species parasitizing the eye were selected differently, as were the two species parasitizing the lymphatic system. The most immunogenic regions of L. loa and W. bancrofti ALT-2 sequence as modeled by antigenicity prediction analysis did not correspond with elevated levels of diversifying selection, and were not selected differently than predicted antigenic epitopes in B. malayi and O. volvulus. Measurements of ALT-2 evolvability made by χ2 analysis between alleles that were stable (O. volvulus and B. malayi) and those that were under diversifying selection (W. bancrofti and L. loa) indicated significant (P<0

  14. Divergent parasite faunas in adjacent populations of West Greenland caribou: suggested natural and anthropogenic influences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal parasite diversity was characterized for two adjacent populations of west Greenland caribou (Rangifer tarandus groenlandicus) through examinations of abomasa and small intestines of adult and subadult females collected during late winter. Three trichostrongyline (Trichostrongylina: ...

  15. Use of Iodogen and sulfosuccinimidobiotin to identify and isolate cuticular proteins of the filarial parasite Brugia malayi.

    PubMed

    Alvarez, R M; Henry, R W; Weil, G J

    1989-03-01

    The cuticle of filarial nematodes is a dynamic structure which may be an important target for protective host immune responses. Prior studies have employed radioiodination of intact parasites to demonstrate that the collagenous cuticle of filariids contains relatively few exposed proteins, some of which are stage and/or species-specific. In the present study, we have used sulfo-NHS-biotin to label and affinity purify cuticular components of living adult Brugia malayi. Results obtained by this method were compared with the widely used Iodogen method of surface radioiodination by SDS-PAGE analysis of detergent-solubilized worms and by ultrastructural analysis. Both labeling methods produced very similar electrophoretic patterns with major doublets at 70 and 100 kDa, a major band at 25 kDa, and minor bands between 60-200 kDa. Ultrastructural analysis showed that both methods labeled components throughout all levels of the parasite cuticle; underlying somatic tissues were not labeled. The biotinylated components were isolated from the total parasite extract by affinity chromatography on an avidin matrix. Further characterization of these surface-associated proteins may lead to improved methods for the control of filariasis.

  16. Chemical ecology and isolation of biologically active compounds from parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root knot nematodes (Meloidogyne spp) are possibly the economically most important and best-studied species of plant parasitic nematodes. However, for Meloidogyne spp and the intensely studied nematode, Caenorhabditis elegans, very little is known about signaling within and in-between species. It h...

  17. Does natural larval parasitism of Lobesia botrana (Lepidoptera: Tortricidae) vary between years, generation, density of the host and vine cultivar?

    PubMed

    Xuéreb, A; Thiéry, D

    2006-04-01

    Populations of European grapevine moth Lobesia botrana Denis & Schiffermüller and its larval parasitoids were studied for two consecutive years on an experimental insecticide-free vineyard in France planted with adjacent plots of five grape cultivars (Merlot, Cabernet Franc, Sauvignon, Cabernet Sauvignon and Sémillon) using a natural L. botrana population during the first year, and a natural population supplemented with artificially inoculated individuals during the second year. Levels of natural populations of larval parasitoids were measured by their parasitism rate. The ichneumonid Campoplex capitator Aubert was the most common species collected from L. botrana larvae. Its incidence was higher during the spring compared to summer. The overall parasitism rate found on the experimental vineyard varied from 23% in 2000 to 53% in 2001, and was mainly due to C. capitator. Parasitism was not affected by the grape cultivar on which the host developed but was positively correlated with the host density, per bunch or per stock, suggesting that among the five grape cultivars tested, C. capitator females probably do not discriminate between hosts feeding on different grape cultivars, but rather the densities of L. botrana larvae.

  18. Isolation of a Defective Prion Mutant from Natural Scrapie

    PubMed Central

    Migliore, Sergio; Cosseddu, Gian Mario; Pirisinu, Laura; Riccardi, Geraldina; Nonno, Romolo

    2016-01-01

    It is widely known that prion strains can mutate in response to modification of the replication environment and we have recently reported that prion mutations can occur in vitro during amplification of vole-adapted prions by Protein Misfolding Cyclic Amplification on bank vole substrate (bvPMCA). Here we exploited the high efficiency of prion replication by bvPMCA to study the in vitro propagation of natural scrapie isolates. Although in vitro vole-adapted PrPSc conformers were usually similar to the sheep counterpart, we repeatedly isolated a PrPSc mutant exclusively when starting from extremely diluted seeds of a single sheep isolate. The mutant and faithful PrPSc conformers showed to be efficiently autocatalytic in vitro and were characterized by different PrP protease resistant cores, spanning aa ∼155–231 and ∼80–231 respectively, and by different conformational stabilities. The two conformers could thus be seen as different bona fide PrPSc types, putatively accounting for prion populations with different biological properties. Indeed, once inoculated in bank vole the faithful conformer was competent for in vivo replication while the mutant was unable to infect voles, de facto behaving like a defective prion mutant. Overall, our findings confirm that prions can adapt and evolve in the new replication environments and that the starting population size can affect their evolutionary landscape, at least in vitro. Furthermore, we report the first example of “authentic” defective prion mutant, composed of brain-derived PrPC and originating from a natural scrapie isolate. Our results clearly indicate that the defective mutant lacks of some structural characteristics, that presumably involve the central region ∼90–155, critical for infectivity but not for in vitro replication. Finally, we propose a molecular mechanism able to account for the discordant in vitro and in vivo behavior, suggesting possible new paths for investigating the molecular bases of

  19. Alkaloids Isolated from Natural Herbs as the Anticancer Agents

    PubMed Central

    Lu, Jin-Jian; Bao, Jiao-Lin; Chen, Xiu-Ping; Huang, Min; Wang, Yi-Tao

    2012-01-01

    Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation and antimetastasis effects on various types of cancers both in vitro and in vivo. Alkaloids, such as camptothecin and vinblastine, have already been successfully developed into anticancer drugs. This paper focuses on the naturally derived alkaloids with prospective anticancer properties, such as berberine, evodiamine, matrine, piperine, sanguinarine, and tetrandrine, and summarizes the mechanisms of action of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as anticancer agents is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made. PMID:22988474

  20. Table wine from tropical fruits utilizing natural yeast isolates.

    PubMed

    Baidya, Dipak; Chakraborty, Ivi; Saha, Jayanta

    2016-03-01

    An attempt was made to utilize few widely available tropical fruits to develop wine with the objective of comparing the fermentation efficiency (along with progress in fermentation) of two efficient yeast isolates with commercially available strain. Fruit wine from juices of fully ripe mango, jackfruit and pineapple alone and in blended combinations of all three fruit juice (2: 1: 2) was prepared using two different yeasts (Y4 and Y7) isolated from natural plain date palm juice and one standard Saccharomyces cerevisiae (MTCC-170) collected from IMTECH, Chandigar. Juices were extracted by using pectinase enzyme at 0.15-0.20 % of pulp. Changes in °Brix, titratable acid content, pH, total viable yeast count were recorded and rate of fermentation, sugar use efficiency were determined at every 24-hour interval up to the completion (6 days after inoculation) of fermentation. Considering all the quality parameter as well as fermentation efficiency, yeast isolate Y7 was found superior followed by Y4 as fermenting agent and pineapple juice as sole substrate found to be the most suitable medium for production of wine followed by fruit juice blending. In interpreting the efficacy of fruit and yeast in combination, pineapple juice inoculated with Y7 found to be the best in reducing the degree Brix to its lowest from initial 24 degree.

  1. Isolation and Characterization of Erythrocyte and Parasite Membranes from Rhesus Red Cells Infected with P. knowlesi.

    DTIC Science & Technology

    1979-04-01

    THIS PAGE (When Data Entered) SECURITY CLASSIFICATION OF THIS PAGK(Whm Daa noamd) Block 20 (continued). and 14C- fucose associated mostly with host cell...humidified incubator 3.4 .4perfused with 10% C02, 8% 02 and 82% N2 Cjaminc acids, C Ciglucosamilne [14 Clgalactose and [ 14C] fucose were added to a final...2 Indicated that glucosamine ,as ngQ;gpqte4 into the parasite to a larger extent than into the erythrocyte membrane whereas galactose and fucose was

  2. Natural Vaccinia Virus Infection: Diagnosis, Isolation, and Characterization.

    PubMed

    Geessien Kroon, Erna; Santos Abrahão, Jônatas; de Souza Trindade, Giliane; Pereira Oliveira, Graziele; Moreira Franco Luiz, Ana Paula; Barbosa Costa, Galileu; Teixeira Lima, Mauricio; Silva Calixto, Rafael; de Oliveira, Danilo Bretas; Drumond, Betânia Paiva

    2016-08-12

    Natural infections of Vaccinia virus (VACV)-the prototype species of the Orthopoxvirus genus, from the family Poxviridae and subfamily Chordopoxvirinae-cause an occupational emergent zoonotic disease that is primarily associated with the handling of infected dairy cattle. In humans, VACV infection is characterized by skin lesions, primarily on the hands, and accompanied by systemic symptoms such as fever, myalgia, headache, and lymphadenopathy. The diagnosis of VACV is usually performed according to the methods described for other orthopoxviruses. This unit describes the methods utilized to obtain clinical samples, the serological and molecular techniques used for diagnosis, and the isolation methods and techniques used for molecular and biological characterization of the viruses. © 2016 by John Wiley & Sons, Inc.

  3. Apoptosis, inflammatory response and parasite load in skin of Leishmania (Leishmania) chagasi naturally infected dogs: a histomorphometric analysis.

    PubMed

    Verçosa, Bárbara Laurice Araújo; Melo, Maria Norma; Puerto, Helen Lima Del; Mendonça, Ivete Lopes; Vasconcelos, Anilton César

    2012-10-26

    The skin has an important role in infection by Leishmania chagasi. Apoptosis modulates the inflammatory response acting distinctively either on the progression or regression of the lesions. The parasites interact with multiple regulatory systems inducing apoptosis in host cells, during cell invasion, stabilization and multiplication of pathogens. In this context, the aim of this study was to evaluate cell death within the inflammatory infiltrates, and to correlate these results with parasite load and clinical features of dogs naturally infected with L. chagasi. Fragments of skin pinnas (8 symptomatic+8 asymptomatic+6 negative controls) were used to characterize and measure the inflammatory response, parasite load and apoptosis. Diagnosis of canine leishmaniasis was confirmed by the detection of anti-Leishmania antibodies by IFA and ELISA in serum, direct visualization of the parasite and culture in spleen, liver, pinna, bone marrow and lymph nodes, and PCR (pinna). Histomorphometry was performed with images obtained from 20 representative histological fields in a light microscope. Ultra-thin sections were mounted over a 300 mesh grids, contrasted with 2% uranyl acetate and lead citrate and examined under a Transmission Electronic Microscopy. Amastigotes were only found in the skin of symptomatic animals (31.94 ± 18.81). The number of foci and cellularity of the inflammatory infiltrates in symptomatic dogs were higher than in other groups and in asymptomatics were higher than in controls (p<0.05; Tukey). The average area, perimeter and extreme diameters of the inflammatory infiltrates obtained in symptomatic dogs were higher than in controls (p<0.05; Tukey). The apoptotic index was higher in symptomatic than in other groups and there was no difference between asymptomatics and controls (p<0.05; Tukey). Ultrastructurally, apoptotic cells were shrunken, with condensed nuclear chromatin and cytoplasm. Condensed nuclei were frequently fragmented. Internucleosomal DNA

  4. Natural history and morphology of the hoverfly Pseudomicrodon biluminiferus and its parasitic relationship with ants nesting in bromeliads.

    PubMed

    Schmid, Volker S; Morales, Mírian N; Marinoni, Luciane; Kamke, Rafael; Steiner, Josefina; Zillikens, Anne

    2014-03-12

    The syrphid subfamily Microdontinae is characterized by myrmecophily of their immature stages, i.e., they develop in ant nests. Data on natural history of microdontines are scarce, especially in the Neotropics. Based on fieldwork in southern Brazil, this study provided new data on development and ecology of the hoverfly Pseudomicrodon biluminiferus (Hull) (Diptera: Syrphidae) as well as the first morphological descriptions of male genitalia, larvae, and pupa. Immature specimens were specifically found in colonies of the ant species Crematogaster limata Smith (Hymenoptera: Formicidae) found in rosettes of the bromeliad species Aechmea lindenii (E. Morren) Baker (Poales: Bromeliaceae) and A. nudicaulis (L.) Grisebach. Third instar larvae were observed preying on ant larvae, revealing the parasitic nature of P. biluminiferus. In this and several other aspects, the natural history of P. biluminiferus is similar to that of Holarctic microdontine species. Exceptions include: (i) indications that adults of P. biluminiferus outlast the winter months (in contrast to 3(rd)instar larvae in Holarctic species) and (ii) P. biluminiferus' relationship with bromeliads. The importance of bromeliads for this host-parasite system is evaluated in this paper. The single occurrence of another, unidentified microdontine species' pupae in a nest of the ant species Camponotus melanoticus Emery (Hymenoptera: Formicidae) is reported.

  5. A Natural Cattle Immune Response Against Horn Fly (Diptera: Muscidae) Salivary Antigens May Regulate Parasite Blood Intake.

    PubMed

    Breijo, M; Pastro, L; Rocha, S; Ures, X; Alonzo, P; Santos, M; Bolatto, C; Fernández, C; Meikle, A

    2016-08-01

    The horn fly, Haematobia irritans (L.), is a blood-sucking ectoparasite that is responsible for sizeable economic losses in livestock. The salivary gland products facilitate blood intake. Taking advantage of the identification of novel H. irritans salivary antigens (Hematobin, HTB and Irritans 5, IT5), we investigated the parasite loads, H. irritans blood intake, and antibody response of naturally infected bovines during the fly season. Fly loads and fly hemoglobin content fluctuated during the trial. Each time horn fly loads exceeded 200 flies per cattle, a reduction in horn fly blood intake was observed three weeks later. All of the cattle elicited an antibody response against HTB and IT5 that declined once the fly season was over. Cattle anti-IT5 titers were positively correlated with parasite loads and negatively correlated with fly blood intake. These results suggest that the natural changes in the H. irritans blood intake observed in this study were associated with a natural host response against horn fly salivary antigens.

  6. Characterization of Amoeboaphelidium protococcarum, an algal parasite new to the cryptomycota isolated from an outdoor algal pond used for the production of biofuel.

    PubMed

    Letcher, Peter M; Lopez, Salvador; Schmieder, Robert; Lee, Philip A; Behnke, Craig; Powell, Martha J; McBride, Robert C

    2013-01-01

    Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the phylum is more

  7. Characterization of Amoeboaphelidium protococcarum, an Algal Parasite New to the Cryptomycota Isolated from an Outdoor Algal Pond Used for the Production of Biofuel

    PubMed Central

    Letcher, Peter M.; Lopez, Salvador; Schmieder, Robert; Lee, Philip A.; Behnke, Craig; Powell, Martha J.; McBride, Robert C.

    2013-01-01

    Mass culture of algae for the production of biofuels is a developing technology designed to offset the depletion of fossil fuel reserves. However, large scale culture of algae in open ponds can be challenging because of incidences of infestation with algal parasites. Without knowledge of the identity of the specific parasite and how to control these pests, algal-based biofuel production will be limited. We have characterized a eukaryotic parasite of Scenedesmus dimorphus growing in outdoor ponds used for biofuel production. We demonstrated that as the genomic DNA of parasite FD01 increases, the concentration of S. dimorphus cells decreases; consequently, this is a highly destructive pathogen. Techniques for culture of the parasite and host were developed, and the endoparasite was identified as the Aphelidea, Amoeboaphelidium protococcarum. Phylogenetic analysis of ribosomal sequences revealed that parasite FD01 placed within the recently described Cryptomycota, a poorly known phylum based on two species of Rozella and environmental samples. Transmission electron microscopy demonstrated that aplanospores of the parasite produced filose pseudopodia, which contained fine fibers the diameter of actin microfilaments. Multiple lipid globules clustered and were associated with microbodies, mitochondria and a membrane cisternae, an arrangement characteristic of the microbody-lipid globule complex of chytrid zoospores. After encystment and attachment to the host cells, the parasite injected its protoplast into the host between the host cell wall and plasma membrane. At maturity the unwalled parasite occupied the entire host cell. After cleavage of the protoplast into aplanospores, a vacuole and lipids remained in the host cell. Amoeboaphelidium protococcarum isolate FD01 is characteristic of the original description of this species and is different from strain X-5 recently characterized. Our results help put a face on the Cryptomycota, revealing that the phylum is more

  8. Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite

    PubMed Central

    de Roode, Jacobus C.; Yates, Andrew J.; Altizer, Sonia

    2008-01-01

    Why do parasites harm their hosts? Conventional wisdom holds that because parasites depend on their hosts for survival and transmission, they should evolve to become benign, yet many parasites cause harm. Theory predicts that parasites could evolve virulence (i.e., parasite-induced reductions in host fitness) by balancing the transmission benefits of parasite replication with the costs of host death. This idea has led researchers to predict how human interventions—such as vaccines—may alter virulence evolution, yet empirical support is critically lacking. We studied a protozoan parasite of monarch butterflies and found that higher levels of within-host replication resulted in both higher virulence and greater transmission, thus lending support to the idea that selection for parasite transmission can favor parasite genotypes that cause substantial harm. Parasite fitness was maximized at an intermediate level of parasite replication, beyond which the cost of increased host mortality outweighed the benefit of increased transmission. A separate experiment confirmed genetic relationships between parasite replication and virulence, and showed that parasite genotypes from two monarch populations caused different virulence. These results show that selection on parasite transmission can explain why parasites harm their hosts, and suggest that constraints imposed by host ecology can lead to population divergence in parasite virulence. PMID:18492806

  9. Gastrointestinal parasites in an isolated Norwegian population of wild red deer (Cervus elaphus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thirteen red deer, culled from the isolated population at the Mongstad Oil Refinery, were investigated for gastrointestinal helminths. These animals, enclosed by the refinery fence, do not have contact with other ruminants and have a high population density considering the available browsing area (1...

  10. Establishment of exotic parasites: the origins and characteristics of an avian malaria community in an isolated island avifauna.

    PubMed

    Ewen, John G; Bensch, Staffan; Blackburn, Tim M; Bonneaud, Camille; Brown, Ruth; Cassey, Phillip; Clarke, Rohan H; Pérez-Tris, Javier

    2012-10-01

    Knowledge of the processes favouring the establishment of exotic parasites is poor. Herein, we test the characteristics of successful exotic parasites that have co-established in the remote island archipelago of New Zealand, due to the introduction of numerous avian host species. Our results show that avian malaria parasites (AM; parasites of the genus Plasmodium) that successfully invaded are more globally generalist (both geographically widespread and with a broad taxonomic range of hosts) than AM parasites not co-introduced to New Zealand. Furthermore, the successful AM parasites are presently more prevalent in their native range than AM parasites found in the same native range but not co-introduced to New Zealand. This has resulted in an increased number and greater taxonomic diversity of AM parasites now in New Zealand.

  11. Utilizing a shallow trench isolation parasitic transistor to characterize the total ionizing dose effect of partially-depleted silicon-on-insulator input/output n-MOSFETs

    NASA Astrophysics Data System (ADS)

    Peng, Chao; Hu, Zhi-Yuan; Ning, Bing-Xu; Huang, Hui-Xiang; Fan, Shuang; Zhang, Zheng-Xuan; Bi, Da-Wei; En, Yun-Fei

    2014-09-01

    We investigate the effects of 60Co γ-ray irradiation on the 130 nm partially-depleted silicon-on-isolator (PDSOI) input/output (I/O) n-MOSFETs. A shallow trench isolation (STI) parasitic transistor is responsible for the observed hump in the back-gate transfer characteristic curve. The STI parasitic transistor, in which the trench oxide acts as the gate oxide, is sensitive to the radiation, and it introduces a new way to characterize the total ionizing dose (TID) responses in the STI oxide. A radiation enhanced drain induced barrier lower (DIBL) effect is observed in the STI parasitic transistor. It is manifested as the drain bias dependence of the radiation-induced off-state leakage and the increase of the DIBL parameter in the STI parasitic transistor after irradiation. Increasing the doping concentration in the whole body region or just near the STI sidewall can increase the threshold voltage of the STI parasitic transistor, and further reduce the radiation-induced off-state leakage. Moreover, we find that the radiation-induced trapped charge in the buried oxide leads to an obvious front-gate threshold voltage shift through the coupling effect. The high doping concentration in the body can effectively suppress the radiation-induced coupling effect.

  12. The helminth parasites of various artiodactylids from some South African nature reserves.

    PubMed

    Boomker, J; Horak, I G; De Vos, V

    1986-06-01

    The helminth species composition and helminth burdens of 4 grey duikers, 12 bushbuck, 2 nyala, 2 giraffe, a steenbok, an oribi, a waterbuck and a tsessebe from the Kruger National Park (KNP); of a steenbok and a greater kudu from the farm Riekerts Laager, Transvaal; of a single blue duiker from the Tsitsikama Forest National Park, and of a blue wildebeest, a red hartebeest, a gemsbok and 2 springbok from the Kalahari Gemsbok National Park (KGNP) were collected, counted and identified. New parasite records are: Agriostomum equidentatum from the gemsbok, Cooperia neitzi from the bushbuck, Cooperia sp. from the gemsbok and the red hartebeest, Cooperia yoshidai from the waterbuck and the tsessebe, Dictyocaulus viviparus from the bushbuck, Haemonchus bedfordi from the waterbuck, Haemonchus contortus from the gemsbok, Haemonchus krugeri from the steenbok from the KNP, Impalaia nudicollis from the gemsbok and the red hartebeest, Impalaia tuberculata from the oribi and the waterbuck, Impalaia spp. from the kudu, Longistrongylus meyeri from the steenbok from Riekerts Laager and the gemsbok, Longistrongylus sabie from the steenbok from the KNP, Longistrongylus schrenki from the tsessebe, Parabronema sp. from the tsessebe and the red hartebeest, Paracooperia serrata from the gemsbok and the steenbok from the KGNP, Pneumostrongylus calcaratus from the bushbuck, Strongyloides sp. from the gemsbok, Trichostrongylus sp. from the gemsbok, the red hartebeest and the steenbok from the KGNP, Trichostrongylus axei from the blue duiker, Trichostrongylus falculatus from the bushbuck and the oribi, Trichostrongylus instabilis from the bushbuck, the steenbok from the KNP and the oribi and Trichostrongylus thomasi from the grey duikers and tsessebe. Host specificity of the parasites was not marked and crossinfestation was common. This was not true for the giraffe, since none of the helminths of these animals were found in the antelope and vice versa.

  13. Photosensitized degradation of amoxicillin in natural organic matter isolate solutions.

    PubMed

    Xu, Haomin; Cooper, William J; Jung, Jinyoung; Song, Weihua

    2011-01-01

    Amoxicillin is a widely used antibiotic and has been detected in natural waters. Its environmental fate is in part determined by hydrolysis, and, direct and indirect photolysis. The hydrolysis rate in distilled water and water to which five different isolated of dissolved organic matter (DOM) was added, were evaluated. In the five different DOM solutions hydrolysis accounted for 5-18% loss of amoxicillin. Direct and indirect photolysis rates were determined using a solar simulator and it appeared that indirect photolysis was the dominant loss mechanism. Direct photolysis, in a solar simulator, accounted for 6-21% loss of amoxicillin in the simulated natural waters. The steady-state concentrations of singlet oxygen, (1)ΔO(2) (∼10(-13) M) and hydroxyl radical, •OH (∼10(-17) M) were obtained in aqueous solutions of five different dissolved organic matter samples using a solar simulator. The bimolecular reaction rate constant of (1)ΔO(2) with amoxicillin was measured in the different solutions, k(ΔO(2)) = 1.44 × 10(4) M(-1) s(-1). The sunlight mediated amoxicillin loss rate with (1)ΔO(2) (∼10(-9) s(-1)), and with •OH (∼10(-7) s(-1)), were also determined for the different samples of DOM. While (1)ΔO(2) only accounted for 0.03-0.08% of the total loss rate, the hydroxyl radical contributed 10-22%. It appears that the direct reaction of singlet and triplet excited state DOM ((3)DOM(∗)) with amoxicillin accounts for 48-74% of the loss of amoxicillin. Furthermore, the pseudo first-order photodegradation rate showed a positive correlation with the sorption of amoxicillin to DOM, which further supported the assumption that excited state DOM∗ plays a key role in the photochemical transformation of amoxicillin in natural waters. This is the first study to report the relative contribution of all five processes to the fate of amoxicillin in aqueous solution.

  14. New and bioactive natural products isolated from madagascar plants and marine organisms.

    PubMed

    Hou, Y; Harinantenaina, L

    2010-01-01

    Madagascar, the world's fourth biggest island has an unique biodiversity. The interest on the phytochemical investigation of Malagasy plants and marine natural products started from the isolation of the potent anti-cancerous bisindole alkaloids: vinblastine and vincristine. In this paper, works published in the last two decades (1991-2009) on 270 new natural products isolated from Madagascar higher plants, liverworts and marine organisms are reviewed. Several results on the bioassays of the isolated new natural products have been reported.

  15. Differential survival of Ichthyophonus isolates indicates parasite adaptation to its host environment

    USGS Publications Warehouse

    Hershberger, P.K.; Pacheco, C.A.; Gregg, J.L.; Purcell, M.K.; LaPatra, S.E.

    2008-01-01

    In vitro viability of Ichthyophonus spp. spores in seawater and freshwater corresponded with the water type of the host from which the spores were isolated. Among Ichthyophonus spp. spores from both marine and freshwater fish hosts (Pacific herring, Clupea pallasii, and rainbow trout, Oncorhynchus mykiss, respectively), viability was significantly greater (P < 0.05) after incubation in seawater than in freshwater at all time points from 1 to 60 min after immersion; however, magnitude of the spore tolerances to water type differed with host origin. Ichthyophonus sp. adaptation to its host environment was indicated by greater seawater tolerance of spores from the marine host and greater freshwater tolerance of spores from the freshwater host. Prolonged aqueous survival of Ichthyophonus spp. spores in the absence of a host provides insight into routes of transmission, particularly among planktivorous fishes, and should be considered when designing strategies to dispose of infected fish carcasses and tissues.

  16. Variable virulence among isolates of Ascosphaera apis: testing the parasite-pathogen hypothesis for the evolution of polyandry in social insects

    NASA Astrophysics Data System (ADS)

    Lee, G. M.; McGee, P. A.; Oldroyd, B. P.

    2013-03-01

    The queens of many eusocial insect species are polyandrous. The evolution of polyandry from ancestral monoandry is intriguing because polyandry undermines the kin-selected benefits of high intracolonial relatedness that are understood to have been central to the evolution of eusociality. An accumulating body of evidence suggests that polyandry evolved from monoandry in part because genetically diverse colonies better resist infection by pathogens. However, a core assumption of the "parasite-pathogen hypothesis", that there is variation in virulence among strains of pathogens, remains largely untested in vivo. Here, we demonstrate variation in virulence among isolates of Ascosphaera apis, the causative organism of chalkbrood disease in its honey bee ( Apis mellifera) host. More importantly, we show a pathogen-host genotypic interaction for resistance and pathogenicity. Our findings therefore support the parasite-parasite hypothesis as a factor in the evolution of polyandry among eusocial insects.

  17. A Natural Chimeric Pseudomonas Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter.

    PubMed

    Ghequire, Maarten G K; Kemland, Lieselore; Anoz-Carbonell, Ernesto; Buchanan, Susan K; De Mot, René

    2017-02-21

    Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin's activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module. We demonstrate strain-specific inhibitory activity for PmnH, a Pseudomonas bacteriocin with an unprecedented dual-toxin architecture, hosting both a colicin M domain, potentially interfering with peptidoglycan synthesis, and a novel colicin N-type domain, a pore-forming module distinct from the colicin Ia-type domain in Pseudomonas aeruginosa pyocin S5. A downstream-linked gene product confers PmnH immunity upon susceptible strains. This protein, ImnH, has a transmembrane topology similar to that of Pseudomonas colicin M-like and pore-forming immunity proteins, although homology with either of these is essentially absent. The enhanced killing activity of PmnH under iron-limited growth conditions reflects parasitism of the ferrichrome-type transporter for entry into target cells, a strategy shown here to be used as well by monodomain colicin M-like bacteriocins from pseudomonads. The integration of a second type of toxin module in a bacteriocin gene could offer a competitive advantage against bacteria displaying immunity against only one of both toxic activities.IMPORTANCE In their continuous struggle for ecological space, bacteria face a huge load of contenders, including phylogenetically related strains that compete for the same niche. One important group of secreted antibacterial proteins assisting in eliminating these rivals are modular bacteriocins of Gram-negative bacteria, comprising a domain for docking onto the

  18. Revealing natural antisense transcripts from Plasmodium vivax isolates: evidence of genome regulation in complicated malaria.

    PubMed

    Boopathi, P A; Subudhi, Amit Kumar; Garg, Shilpi; Middha, Sheetal; Acharya, Jyoti; Pakalapati, Deepak; Saxena, Vishal; Aiyaz, Mohammed; Chand, Bipin; Mugasimangalam, Raja C; Kochar, Sanjay K; Sirohi, Parmendra; Kochar, Dhanpat K; Das, Ashis

    2013-12-01

    Plasmodium vivax is the most geographically widespread human malaria parasite causing approximately 130-435 million infections annually. It is an economic burden in many parts of the world and poses a public health challenge along with the other Plasmodium sp. The biology of this parasite is less studied and poorly understood, in spite of these facts. Emerging evidence of severe complications due to infections by this parasite provides an impetus to focus research on the same. Investigating the parasite directly from infected patients is the best way to study its biology and pathogenic mechanisms. Gene expression studies of this parasite directly obtained from the patients has provided evidence of gene regulation resulting in varying amount of transcript levels in the different blood stages. The mechanisms regulating gene expression in malaria parasites are not well understood. Discovery of Natural Antisense Transcripts (NATs) in Plasmodium falciparum has suggested that these might play an important role in regulating gene expression. We report here the genome-wide occurrence of NATs in P. vivax parasites from patients with differing clinical symptoms. A total of 1348 NATs against annotated gene loci have been detected using a custom designed microarray with strand specific probes. Majority of NATs identified from this study shows positive correlation with the expression pattern of the sense (S) transcript. Our data also shows condition specific expression patterns of varying S and antisense (AS) transcript levels. Genes with AS transcripts enrich to various biological processes. To our knowledge this is the first report on the presence of NATs from P. vivax obtained from infected patients with different disease complications. The data suggests differential regulation of gene expression in diverse clinical conditions, as shown by differing sense/antisense ratios and would lead to future detailed investigations of gene regulation.

  19. The Ity/Lsh/Bcg locus: natural resistance to infection with intracellular parasites is abrogated by disruption of the Nramp1 gene.

    PubMed

    Vidal, S; Tremblay, M L; Govoni, G; Gauthier, S; Sebastiani, G; Malo, D; Skamene, E; Olivier, M; Jothy, S; Gros, P

    1995-09-01

    In mice, natural resistance or susceptibility to infection with intracellular parasites is determined by a locus or group of loci on chromosome 1, designated Bcg, Lsh, and Ity, which controls early microbial replication in reticuloendothelial organs. We have identified by positional cloning a candidate gene for Bcg, Nramp1, which codes for a novel macrophage-specific membrane transport protein. We have created a mouse mutant bearing a null allele at Nramp1, and we have analyzed the effect of such a mutation on natural resistance to infection. Targeted disruption of Nramp1 has pleiotropic effects on natural resistance to infection with intracellular parasites, as it eliminated resistance to Mycobacterium bovis, Leishmania donovani, and lethal Salmonella typhimurium infection, establishing that Nramp1, Bcg, Lsh, and Ity are the same locus. Comparing the profiles of parasite replication in control and Nramp1-/- mice indicated that the Nramp1Asp169 allele of BcgS inbred strains is a null allele, pointing to a critical role of this residue in the mechanism of action of the protein. Despite their inability to control parasite growth in the early nonimmune phase of the infection, Nramp1-/- mutants can overcome the infection in the late immune phase, suggesting that Nramp1 plays a key role only in the early part of the macrophage-parasite interaction and may function by a cytocidal or cytostatic mechanism distinct from those expressed by activated macrophages.

  20. A Natural Chimeric Pseudomonas Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter

    PubMed Central

    Kemland, Lieselore; Anoz-Carbonell, Ernesto; Buchanan, Susan K.; De Mot, René

    2017-01-01

    ABSTRACT Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin’s activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module. We demonstrate strain-specific inhibitory activity for PmnH, a Pseudomonas bacteriocin with an unprecedented dual-toxin architecture, hosting both a colicin M domain, potentially interfering with peptidoglycan synthesis, and a novel colicin N-type domain, a pore-forming module distinct from the colicin Ia-type domain in Pseudomonas aeruginosa pyocin S5. A downstream-linked gene product confers PmnH immunity upon susceptible strains. This protein, ImnH, has a transmembrane topology similar to that of Pseudomonas colicin M-like and pore-forming immunity proteins, although homology with either of these is essentially absent. The enhanced killing activity of PmnH under iron-limited growth conditions reflects parasitism of the ferrichrome-type transporter for entry into target cells, a strategy shown here to be used as well by monodomain colicin M-like bacteriocins from pseudomonads. The integration of a second type of toxin module in a bacteriocin gene could offer a competitive advantage against bacteria displaying immunity against only one of both toxic activities. PMID:28223456

  1. Advanced Natural Gas Reciprocating Engine: Parasitic Loss Control through Surface Modification

    SciTech Connect

    Farshid Sadeghi; Chin-Pei Wang

    2008-12-31

    This report presents results of our investigation on parasitic loss control through surface modification in reciprocating engine. In order to achieve the objectives several experimental and corresponding analytical models were designed and developed to corroborate our results. Four different test rigs were designed and developed to simulate the contact between the piston ring and cylinder liner (PRCL) contact. The Reciprocating Piston Test Rig (RPTR) is a novel suspended liner test apparatus which can be used to accurately measure the friction force and side load at the piston-cylinder interface. A mixed lubrication model for the complete ring-pack and piston skirt was developed to correlate with the experimental measurements. Comparisons between the experimental and analytical results showed good agreement. The results revealed that in the reciprocating engines higher friction occur near TDC and BDC of the stroke due to the extremely low piston speed resulting in boundary lubrication. A Small Engine Dynamometer Test Rig was also designed and developed to enable testing of cylinder liner under motored and fired conditions. Results of this study provide a baseline from which to measure the effect of surface modifications. The Pin on Disk Test Rig (POD) was used in a flat-on-flat configuration to study the friction effect of CNC machining circular pockets and laser micro-dimples. The results show that large and shallow circular pockets resulted in significant friction reduction. Deep circular pockets did not provide much load support. The Reciprocating Liner Test Rig (RLTR) was designed to simplifying the contact at the PRCL interface. Accurate measurement of friction was obtained using 3-axis piezoelectric force transducer. Two fiber optic sensors were used to measure the film thickness precisely. The results show that the friction force is reduced through the use of modified surfaces. The Shear Driven Test Rig (SDTR) was designed to simulate the mechanism of the

  2. Natural genetic and induced plant resistance, as a control strategy to plant-parasitic nematodes alternative to pesticides.

    PubMed

    Molinari, Sergio

    2011-03-01

    Plant-parasitic nematodes are pests of a wide range of economically important crops, causing severe losses to agriculture. Natural genetic resistance of plants is expected to be a valid solution of the many problems nematodes cause all over the world. Progress in resistance applications is particularly important for the less-developed countries of tropical and subtropical regions, since use of resistant cultivars may be the only possible and economically feasible control strategy in those farming systems. Resistance is being considered of particular importance also in modern high-input production systems of developed countries, as the customary reliance on chemical nematicides has been restricted or has come to an end. This review briefly describes the genetic bases of resistance to nematodes in plants and focuses on the chances and problems of its exploitation as a key element in an integrated management program. Much space is dedicated to the major problem of resistance durability, in that the intensive use of resistant cultivars is likely to increasingly induce the selection of virulent populations able to "break" the resistance. Protocols of pest-host suitability are described, as bioassays are being used to evaluate local nematode populations in their potential to be selected on resistant germplasm and endanger resistant crops. The recent progress in using robust and durable resistances against nematodes as an efficient method for growers in vegetable cropping systems is reported, as well as the possible use of chemicals that do not show any unfavorable impact on environment, to induce in plants resistance against plant-parasitic nematodes.

  3. Kinetics of B cell responses to Plasmodium falciparum erythrocyte membrane protein 1 in Ghanaian women naturally exposed to malaria parasites.

    PubMed

    Ampomah, Paulina; Stevenson, Liz; Ofori, Michael F; Barfod, Lea; Hviid, Lars

    2014-06-01

    Naturally acquired protective immunity to Plasmodium falciparum malaria takes years to develop. It relies mainly on Abs, particularly IgG specific for Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) proteins on the infected erythrocyte surface. It is only partially understood why acquisition of clinical protection takes years to develop, but it probably involves a range of immune-evasive parasite features, not least of which are PfEMP1 polymorphism and clonal variation. Parasite-induced subversion of immunological memory and expansion of "atypical" memory B cells may also contribute. In this first, to our knowledge, longitudinal study of its kind, we measured B cell subset composition, as well as PfEMP1-specific Ab levels and memory B cell frequencies, in Ghanaian women followed from early pregnancy up to 1 y after delivery. Cell phenotypes and Ag-specific B cell function were assessed three times during and after pregnancy. Levels of IgG specific for pregnancy-restricted, VAR2CSA-type PfEMP1 increased markedly during pregnancy and declined after delivery, whereas IgG levels specific for two PfEMP1 proteins not restricted to pregnancy did not. Changes in VAR2CSA-specific memory B cell frequencies showed typical primary memory induction among primigravidae and recall expansion among multigravidae, followed by contraction postpartum in all. No systematic changes in the frequencies of memory B cells specific for the two other PfEMP1 proteins were identified. The B cell subset analysis confirmed earlier reports of high atypical memory B cell frequencies among residents of P. falciparum-endemic areas, and indicated an additional effect of pregnancy. Our study provides new knowledge regarding immunity to P. falciparum malaria and underpins efforts to develop PfEMP1-based vaccines against this disease.

  4. From Parasite to Mutualist: Rapid Evolution of Wolbachia in Natural Populations of Drosophila

    PubMed Central

    Weeks, Andrew R; Turelli, Michael; Harcombe, William R; Reynolds, K. Tracy; Hoffmann, Ary A

    2007-01-01

    Wolbachia are maternally inherited bacteria that commonly spread through host populations by causing cytoplasmic incompatibility, often expressed as reduced egg hatch when uninfected females mate with infected males. Infected females are frequently less fecund as a consequence of Wolbachia infection. However, theory predicts that because of maternal transmission, these “parasites” will tend to evolve towards a more mutualistic association with their hosts. Drosophila simulans in California provided the classic case of a Wolbachia infection spreading in nature. Cytoplasmic incompatibility allowed the infection to spread through individual populations within a few years and from southern to northern California (more than 700 km) within a decade, despite reducing the fecundity of infected females by 15%–20% under laboratory conditions. Here we show that the Wolbachia in California D. simulans have changed over the last 20 y so that infected females now exhibit an average 10% fecundity advantage over uninfected females in the laboratory. Our data suggest smaller but qualitatively similar changes in relative fecundity in nature and demonstrate that fecundity-increasing Wolbachia variants are currently polymorphic in natural populations. PMID:17439303

  5. Life Cycle, Ultrastructure, and Host Specificity of the North American Isolate of Pasteuria that Parasitizes the Soybean Cyst Nematode, Heterodera glycines

    PubMed Central

    Atibalentja, N.; Jakstys, B. P.; Noel, G. R.

    2004-01-01

    Light and transmission electron microscopy were used to investigate the life cycle and ultrastructure of an undescribed isolate of Pasteuria that parasitizes the soybean cyst nematode, Heterodera glycines. Studies also were conducted to determine the host specificity of Pasteuria. The endospores that attached to the cuticle of second-stage juveniles (J2) of H. glycines in soil did not germinate until the encumbered nematodes invaded soybean roots. Thereafter, the bacterium developed and completed its life cycle only in females. The stages of endosporogenesis were typical of Pasteuria spp. The mature endospore, like that of P. nishizawae, the only other Pasteuria known to infect H. glycines, produces an epicortical layer that completely surrounds the cortex, an outer spore coat that tapers progressively from the top to the base of the central body, and a double basal adhesion layer. However, subtle differences exist between the Pasteuria from North America and P. nishizawae with regard to size of the central body, nature and function of the mesosomes observed in the earlier stages of endosporogenesis, and appearance of the fibers lining the basal adhesion layer and the exosporium of the mature endospore. Endospores of the North American Pasteuria attached to J2 of H. schachtii, H. trifolii, and H. lespedezae but not to Meloidogyne arenaria race 1, Tylenchorhynchus nudus, and Labronema sp. Results from this study indicate that the North American Pasteuria is more similar to P. nishizawae than to any other known member of the genus. Additional evidence from comparative analysis of 16S rDNA sequences is needed to clarify whether these two Pasteuria belong to the same species. PMID:19262804

  6. Density-dependent immunity and parasitism risk in experimental populations of lizards naturally infested by ixodid ticks.

    PubMed

    Mugabo, Marianne; Perret, Samuel; Decencière, Beatriz; Meylan, Sandrine; Le Galliard, Jean-François

    2015-02-01

    When effective immune defenses against parasites are costly and resources limited, individuals are expected to alter their investment in immunity in response to the risk of infection. As an ecological factor that can affect both food abundance and parasite exposure, host density can play an important role in host immunity and host-parasite interactions. High levels of intraspecific competition for food and social stress at high host density may diminish immune defenses and increase host susceptibility to parasites. At the same time, for contagious and environmentally transmitted parasites, parasite exposure often increases with host density, whereas in mobile parasites that actively search for hosts, parasite exposure can decrease with host density due to the "encounter-dilution effect." To unravel these multiple and potentially opposing effects of host density on immunity, we manipulated density of the common lizard Zootoca vivipara and measured local inflammation in response to PHA injection and levels of infestation by the tick Ixodes ricinus, a mobile ectoparasite for which we expected an encounter-dilution effect to occur. Local inflammation strongly decreased with lizard density in adults, but not in yearlings. Tick infestation (abundance and prevalence) was negatively correlated with lizard density in both age classes. Using path analyses, we found independent, direct negative density feedbacks on immunity and parasite exposure in adults, supporting the hypothesis of energy constraints and/or physiological stress acting on immunity at high density. In contrast, for yearlings, the best path model showed that density diluted exposure to parasites, which themselves down-regulated immune defenses in lizards. These results highlight the importance of investigating the pathways among host density, host immunity, and parasite infestation, while accounting for relevant individual traits such as age.

  7. Isotype patterns of immunoglobulins: hallmarks for clinical status and tissue parasite density in Brazilian dogs naturally infected by Leishmania (Leishmania) chagasi.

    PubMed

    Reis, Alexandre B; Teixeira-Carvalho, Andréa; Vale, André M; Marques, Marcos J; Giunchetti, Rodolfo C; Mayrink, Wilson; Guerra, Luanda Liboreiro; Andrade, Renata A; Corrêa-Oliveira, Rodrigo; Martins-Filho, Olindo A

    2006-08-15

    The role of anti-leishmanial immune response underlying the susceptibility/resistance during canine visceral leishmaniasis (CVL) has been recognized throughout ex vivo and in vitro investigations. Recently, we demonstrated that immunoglobulin levels (Igs), as well as the parasite load are relevant hallmarks of distinct clinical status of CVL. To further characterize and upgrade the background on this issue, herein, we have evaluated, in Leishmania (Leishmania) chagasi naturally infected dogs, the relationship between tissue parasitism (skin, bone marrow, spleen, liver and lymph node), the CVL clinical status (asymptomatic (AD), with no suggestive signs of the disease; oligosymptomatic (OD), with maximum three clinical signs-opaque bristles; localized alopecia and moderate loss of weight; symptomatic (SD), serologically positive with severe clinical signs of visceral leishmaniasis), and the humoral immunological profile of anti-Leishmania immunoglobulins (IgG, IgG1, IgG2, IgM, IgA and IgE). Our major statistically significant findings revealed distinct patterns of tissue parasite density within L. chagasi-infected dogs despite their clinical status, pointing out the spleen and skin as the most relevant sites of high parasitism during ongoing CVL. Parasite density of bone marrow and spleen were the most reliable parasitological markers to decode the clinical status of CVL. Moreover, the parasite density of bone marrow better correlates with most anti-Leishmania Igs reactivity. Additionally, a prognostic hallmark for canine visceral leishmaniasis was found, highlighting strong correlation between IgG1 and asymptomatic disease, but with IgA, IgE and IgG2 displaying better association with symptomatic disease. The new aspects of this study highlighted pioneer findings that correlated the degree of tissue parasite density (low (LP), medium (MP) and high (HP) parasitism) with distinct patterns of anti-Leishmania Igs reactivity. In this scope, our data re-enforce the anti

  8. Naturally Occurring Lactic Acid Bacteria Isolated from Tomato Pomace Silage

    PubMed Central

    Wu, Jing-jing; Du, Rui-ping; Gao, Min; Sui, Yao-qiang; Xiu, Lei; Wang, Xiao

    2014-01-01

    Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence and carbohydrate fermentation tests, the isolates were identified as 17 species namely: Lactobacillus coryniformis subsp. torquens (0.97%), Lactobacillus pontis (0.97%), Lactobacillus hilgardii (0.97%), Lactobacillus pantheris (0.97%), Lactobacillus amylovorus (1.9%), Lactobacillus panis (1.9%), Lactobacillus vaginalis (1.9%), Lactobacillus rapi (1.9%), Lactobacillus buchneri (2.9%), Lactobacillus parafarraginis (2.9%), Lactobacillus helveticus (3.9%), Lactobacillus camelliae (3.9%), Lactobacillus fermentum (5.8%), Lactobacillus manihotivorans (6.8%), Lactobacillus plantarum (10.7%), Lactobacillus harbinensis (16.5%) and Lactobacillus paracasei subsp. paracasei (35.0%). This study has shown that TP can be well preserved for 90 days by ensilaging and that TPS is not only rich in essential nutrients, but that physiological and biochemical properties of the isolates could provide a platform for future design of lactic acid bacteria (LAB) inoculants aimed at improving the fermentation quality of silage. PMID:25049999

  9. Biogenic amines formation in Streptococcus thermophilus isolated from home-made natural yogurt.

    PubMed

    Gezginc, Yekta; Akyol, Ismail; Kuley, Esmeray; Özogul, Fatih

    2013-05-01

    Twelve different biogenic amines formation in 58 isolates of Streptococcus thermophilus from home-made natural yogurt were investigated in histidine (HDB) and lysine decarboxylase broth (LDB). All S. thermophilus isolates had an ability to produce twelve different biogenic amines in HDB and LDB. Most of the S. thermophilus isolates formed low amounts of histamine (1-50 mg/L) from histidine. Apart from one isolate, S. thermophilus produced tyramine at low (47 isolates) and medium (10 isolates) levels. The amount of each specific biogenic amine produced by S. thermophilus was generally lower than 100 mg L(-1). Also, the presence of hdcA gene was investigated using PCR technique and relation between gene and histamine production was conducted in S. thermophilus isolates. This study showed that most of the S. thermophilus isolates have the ability to form biogenic amines, especially histamine, and tyramine, which is an important consideration when selecting strains as starter cultures.

  10. Natural infection of Nesokia indica with Leishmania major and Leishmania infantum parasites in Damghan city, Northern Iran.

    PubMed

    Pourmohammadi, Behrad; Mohammadi-Azni, Sadegh; Kalantari, Mohsen

    2017-03-04

    Various species of rodents are proven reservoir hosts of zoonotic cutaneous leishmaniasis in different provinces of Iran and potential reservoir hosts of zoonotic visceral leishmaniasis. Therefore, this study was conducted to determine the leishmanial infection of rodents in Damghan city from April to September, 2015. Sum of 100 rodents of three species; Nesokia indica (95), Mus musculus (3), and Microtus socialis (2), were trapped alive and their tissue samples were examined using parasitological and molecular (nested-PCR) methods. A total of 71% (71/100) of examined rodents were parasitological positive for Leishmania spp. amastigotes. The highest rate (72.6%; 69/95) of infection was related to the N. indica species. The microscopic observations showed that 42% of ear samples were positive. Additionally, 12% of rodents with negative ear result were positive in liver. 16 out of 41 (39%) parasitological positive samples, belonging to the N. indica, were shown molecularly positive. Of which, 15 were L. major (13 of ear and 2 of spleen samples) and one of spleen samples was L. infantum. This is the first report of N. indica natural infection with L. infantum parasite. To understand the role of this rodent as reservoir host of L. infantum, extant ecological and epidemiological studies are needed.

  11. Parasitic Diseases With Cutaneous Manifestations.

    PubMed

    Ash, Mark M; Phillips, Charles M

    2016-01-01

    Parasitic diseases result in a significant global health burden. While often thought to be isolated to returning travelers, parasitic diseases can also be acquired locally in the United States. Therefore, clinicians must be aware of the cutaneous manifestations of parasitic diseases to allow for prompt recognition, effective management, and subsequent mitigation of complications. This commentary also reviews pharmacologic treatment options for several common diseases.

  12. Natural efficiency of parasitism by Billaea rhynchophorae (Blanchard) (Diptera: Tachinidae) for the control of Rhynchophorus palmarum (L.) (Coleoptera: Curculionidae).

    PubMed

    Moura, José Inacio L; Toma, Ronaldo; Sgrillo, Ricardo B; Delabie, Jacques H C

    2006-01-01

    The occurrence of the tachinid parasitoid Billaea rhynchophorae (Blanchard) on larvae of the palm weevil Rhynchophorus palmarum (L.) was evaluated in plantations of piassava palm (Attalea funifera Mart.) and African oil palm (Elaeis guineensis Jacquin), in southeastern Bahia, Brazil. The monthly percentages of parasitism were evaluated during 13 months, from November 2000 to November 2001, based on the comparison between the number of parasitized and non-parasitized cocoons of R. palmarum. Mean parasitism was 40% and ranged from 50% in November 2000 to 18% in July 2001. While there is no method of mass reproduction of the parasitoid, a simple management practice is recommended, in order to preserve its beneficial effects in palm plantations.

  13. Parasitism of Odonata by Arrenurus (Acari: Hydrachnidia) larvae in the Lake Świdwie, nature reserve (NW Poland).

    PubMed

    Zawal, Andrzej; Buczyński, Paweł

    2013-12-01

    Larvae of a vast majority of water mite species are parasites of aquatic insects. Owing to this, they migrate to new localities, and are able to survive unfavourable environmental conditions. This also concerns species from subgenus Arrenurus s. str., parasites of dragonflies. The detailed analysis of this phenomenon, however, has only been possible in the last several years, since the key to the identification of larvae from genus Arrenurus Dug. was published. In 2010, the parasitism of Arrenurus s. str. larvae on dragonflies in the Lake Świdwie reserve (NW Poland) was analysed. Larvae of 9 species of water mites were recorded on 107 imagines of dragonflies from 8 species. The following were identified as hosts of water mites for the first time: Anax imperator, Libellula quadrimaculata, and Leucorrhinia caudalis. The highest prevalence occurred in the case of: Erythromma najas and Lestes dryas (100%), Coenagrion pulchellum (96.5%), and C. puella (80.0%). Coenagrion pulchellum was infested by 9 species of parasites, C. puella by 6, and Erythromma najas and Lestes dryas by three species. The highest number of host species occurred in the case of Arrenurus maculator (5); followed by A. cuspidator, A. batillifer cf., A. bicuspidator, and A. tetracyphus (3 each); A. papillator, A. tricuspidator, and A. bruzelii (2 each), and A. claviger (1). Differentiation of preferences of particular parasites towards various parts of the host body was observed, probably related to the coevolution of parasites and hosts, and competition between the host species. The body sizes of the parasites suggest that approximately 50% of body size growth of water mites from subgenus Arrenurus s. str. occurs at the stage of parasitic larva.

  14. Parasites: evolution's neurobiologists.

    PubMed

    Adamo, Shelley Anne

    2013-01-01

    For millions of years, parasites have altered the behaviour of their hosts. Parasites can affect host behaviour by: (1) interfering with the host's normal immune-neural communication, (2) secreting substances that directly alter neuronal activity via non-genomic mechanisms and (3) inducing genomic- and/or proteomic-based changes in the brain of the host. Changes in host behaviour are often restricted to particular behaviours, with many other behaviours remaining unaffected. Neuroscientists can produce this degree of selectivity by targeting specific brain areas. Parasites, however, do not selectively attack discrete brain areas. Parasites typically induce a variety of effects in several parts of the brain. Parasitic manipulation of host behaviour evolved within the context of the manipulation of other host physiological systems (especially the immune system) that was required for a parasite's survival. This starting point, coupled with the fortuitous nature of evolutionary innovation and evolutionary pressures to minimize the costs of parasitic manipulation, likely contributed to the complex and indirect nature of the mechanisms involved in host behavioural control. Because parasites and neuroscientists use different tactics to control behaviour, studying the methods used by parasites can provide novel insights into how nervous systems generate and regulate behaviour. Studying how parasites influence host behaviour will also help us integrate genomic, proteomic and neurophysiological perspectives on behaviour.

  15. Genetic polymorphism and effect of natural selection at domain I of apical membrane antigen-1 (AMA-1) in Plasmodium vivax isolates from Myanmar.

    PubMed

    Moon, Sung-Ung; Na, Byoung-Kuk; Kang, Jung-Mi; Kim, Jung-Yeon; Cho, Shin-Hyeong; Park, Yun-Kyu; Sohn, Woon-Mok; Lin, Khin; Kim, Tong-Soo

    2010-05-01

    Malaria is endemic or hypoendemic in Myanmar and the country still contributes to the high level of malaria deaths in South-East Asia. Although information on the nature and extent of population diversity within malaria parasites in the country is essential not only for understanding the epidemic situation but also to establish a proper control strategy, very little data is currently available on the extent of genetic polymorphisms of the malaria parasites in Myanmar. In this study, we analyzed the genetic polymorphism and natural selection at domain I of the apical membrane antigen-1 (AMA-1) among Plasmodium vivax Myanmar isolates. A total of 34 distinguishable haplotypes were identified among the 76 isolates sequenced. Comparison with the previously available PvAMA-1 sequences in the GenBank database revealed that 21 of them were new haplotypes that have never been reported till date. The difference between the rate of nonsynonymous (dN) and synonymous (dS) mutations was positive (dN-dS, 0.013+/-0.005), suggesting the domain I is under positive natural selection. The Tajima's D statistics was found to be -0.74652, suggesting that the gene has evolved under population size expansion and/or positive selection. The minimum recombination events were also high, indicating that recombination may occur within the domain I resulting in allelic diversity of PvAMA-1. Our results collectively suggest that PvAMA-1 displays high genetic polymorphism among Myanmar P. vivax isolates with highly diversifying selection at domain I. These results have significant implications in understanding the nature of P. vivax population circulating in Myanmar as well as providing useful information for malaria vaccine development based on this antigen.

  16. Morphological, molecular, and phylogenetic characterization of Nosema cerana, a microsporidian parasite isolated from the European honey bee, Apis mellifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nosema ceranae, a microsporidian parasite originally described from Apis cerana, has been found to infect Apis melllifera and is highly pathogenic to its new host. In the present study, data on N. ceranae ultrastructure, host tissue tropism, secondary structures of ribosomal RNA, and phylogenetic ...

  17. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources

    PubMed Central

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-01-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi—the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52–71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles. PMID:26891047

  18. Molecular Individual-Based Approach on Triatoma brasiliensis: Inferences on Triatomine Foci, Trypanosoma cruzi Natural Infection Prevalence, Parasite Diversity and Feeding Sources.

    PubMed

    Almeida, Carlos Eduardo; Faucher, Leslie; Lavina, Morgane; Costa, Jane; Harry, Myriam

    2016-02-01

    We used an individual-based molecular multisource approach to assess the epidemiological importance of Triatoma brasiliensis collected in distinct sites and ecotopes in Rio Grande do Norte State, Brazil. In the semi-arid zones of Brazil, this blood sucking bug is the most important vector of Trypanosoma cruzi--the parasite that causes Chagas disease. First, cytochrome b (cytb) and microsatellite markers were used for inferences on the genetic structure of five populations (108 bugs). Second, we determined the natural T. cruzi infection prevalence and parasite diversity in 126 bugs by amplifying a mini-exon gene from triatomine gut contents. Third, we identified the natural feeding sources of 60 T. brasiliensis by using the blood meal content via vertebrate cytb analysis. Demographic inferences based on cytb variation indicated expansion events in some sylvatic and domiciliary populations. Microsatellite results indicated gene flow between sylvatic and anthropic (domiciliary and peridomiciliary) populations, which threatens vector control efforts because sylvatic population are uncontrollable. A high natural T. cruzi infection prevalence (52-71%) and two parasite lineages were found for the sylvatic foci, in which 68% of bugs had fed on Kerodon rupestris (Rodentia: Caviidae), highlighting it as a potential reservoir. For peridomiciliary bugs, Galea spixii (Rodentia: Caviidae) was the main mammal feeding source, which may reinforce previous concerns about the potential of this animal to link the sylvatic and domiciliary T. cruzi cycles.

  19. Synthesis of Cycloprodigiosin Identifies the Natural Isolate as a Scalemic Mixture

    DOE PAGES

    Johnson, Rebecca E.; de Rond, Tristan; Lindsay, Vincent N. G.; ...

    2015-07-17

    We prepared the enantiomers of the natural product cycloprodigiosin using an expedient five-step synthetic sequence that takes advantage of a Schöllkopf–Barton–Zard (SBZ) pyrrole annulation with a chiral isocyanoacetate and a nitrocyclohexene derivative. Using chiral HPLC and X-ray crystallographic analyses of the synthetically prepared material and natural isolate (isolated from the marine bacterium Pseudoalteromonas rubra), naturally occurring cycloprodigiosin was determined to be a scalemic mixture occurring in an enantiomeric ratio of 83:17 (R)/(S) at C4'.

  20. Natural Parasitism in Fruit Fly (Diptera: Tephritidae) Populations in Disturbed Areas Adjacent to Commercial Mango Orchards in Chiapas and Veracruz, Mexico.

    PubMed

    Montoya, Pablo; Ayala, Amanda; López, Patricia; Cancino, Jorge; Cabrera, Héctor; Cruz, Jassmin; Martinez, Ana Mabel; Figueroa, Isaac; Liedo, Pablo

    2016-04-01

    To determine the natural parasitism in fruit fly populations in disturbed areas adjacent to commercial mango orchards in the states of Chiapas and Veracruz, Mexico, we recorded over one year the fruit fly-host associations, fly infestation, and parasitism rates in backyard orchards and patches of native vegetation. We also investigated the relationship between fruit size, level of larval infestation, and percent of parasitism, and attempted to determine the presence of superparasitism. The most recurrent species in trap catches was Anastrepha obliqua (Macquart), followed by Anastrepha ludens (Loew), in both study zones. The fruit infestation rates were higher in Chiapas than in Veracruz, with A. obliqua again being the most conspicuous species emerging from collected fruits. The diversity of parasitoids species attacking fruit fly larvae was greater in Chiapas, with a predominance of Doryctobracon areolatus (Szépligeti) in both sites, although the exotic Diachasmimorpha longicaudata (Ashmead) was well established in Chiapas. Fruit size was positively correlated with the number of larvae per fruit, but this relationship was not observed in the level of parasitism. The number of oviposition scars was not related to the number of immature parasitoids inside the pupa of D. areolatus emerging from plum fruits. Mass releases of Di. longicaudata seem not to affect the presence or prevalence of the native species. Our findings open new research scenarios on the role and impact of native parasitoid species attacking Anastrepha flies that can contribute to the development of sound strategies for using these species in projects for augmentative biological control.

  1. Cultivation of parasites

    PubMed Central

    Ahmed, Nishat Hussain

    2014-01-01

    Parasite cultivation techniques constitute a substantial segment of present-day study of parasites, especially of protozoa. Success in establishing in vitro and in vivo culture of parasites not only allows their physiology, behavior and metabolism to be studied dynamically, but also allows the nature of the antigenic molecules in the excretory and secretory products to be vigorously pursued and analyzed. The complex life-cycles of various parasites having different stages and host species requirements, particularly in the case of parasitic helminths, often make parasite cultivation an uphill assignment. Culturing of parasites depends on the combined expertise of all types of microbiological cultures. Different parasites require different cultivation conditions such as nutrients, temperature and even incubation conditions. Cultivation is an important method for diagnosis of many clinically important parasites, for example, Entamoeba histolytica, Trichomonas vaginalis, Leishmania spp., Strongyloides stercoralis and free-living amoebae. Many commercial systems like InPouch TV for T. vaginalis, microaerophilous stationary phase culture for Babesia bovis and Harada-Mori culture technique for larval-stage nematodes have been developed for the rapid diagnosis of the parasitic infections. Cultivation also has immense utility in the production of vaccines, testing vaccine efficacy, and antigen - production for obtaining serological reagents, detection of drug-resistance, screening of potential therapeutic agents and conducting epidemiological studies. Though in vitro cultivation techniques are used more often compared with in vivo techniques, the in vivo techniques are sometimes used for diagnosing some parasitic infections such as trypanosomiasis and toxoplasmosis. Parasite cultivation continues to be a challenging diagnostic option. This review provides an overview of intricacies of parasitic culture and update on popular methods used for cultivating parasites. PMID

  2. Comparative Genomics of Saccharomyces cerevisiae Natural Isolates for Bioenergy Production

    PubMed Central

    Wohlbach, Dana J.; Rovinskiy, Nikolay; Lewis, Jeffrey A.; Sardi, Maria; Schackwitz, Wendy S.; Martin, Joel A.; Deshpande, Shweta; Daum, Christopher G.; Lipzen, Anna; Sato, Trey K.; Gasch, Audrey P.

    2014-01-01

    Lignocellulosic plant material is a viable source of biomass to produce alternative energy including ethanol and other biofuels. However, several factors—including toxic byproducts from biomass pretreatment and poor fermentation of xylose and other pentose sugars—currently limit the efficiency of microbial biofuel production. To begin to understand the genetic basis of desirable traits, we characterized three strains of Saccharomyces cerevisiae with robust growth in a pretreated lignocellulosic hydrolysate or tolerance to stress conditions relevant to industrial biofuel production, through genome and transcriptome sequencing analysis. All stress resistant strains were highly mosaic, suggesting that genetic admixture may contribute to novel allele combinations underlying these phenotypes. Strain-specific gene sets not found in the lab strain were functionally linked to the tolerances of particular strains. Furthermore, genes with signatures of evolutionary selection were enriched for functional categories important for stress resistance and included stress-responsive signaling factors. Comparison of the strains’ transcriptomic responses to heat and ethanol treatment—two stresses relevant to industrial bioethanol production—pointed to physiological processes that were related to particular stress resistance profiles. Many of the genotype-by-environment expression responses occurred at targets of transcription factors with signatures of positive selection, suggesting that these strains have undergone positive selection for stress tolerance. Our results generate new insights into potential mechanisms of tolerance to stresses relevant to biofuel production, including ethanol and heat, present a backdrop for further engineering, and provide glimpses into the natural variation of stress tolerance in wild yeast strains. PMID:25364804

  3. Impact of host sex and group composition on parasite dynamics in experimental populations.

    PubMed

    Tadiri, C P; Scott, M E; Fussmann, G F

    2016-04-01

    To better understand the spread of disease in nature, it is fundamentally important to have broadly applicable model systems with readily available species which can be replicated and controlled in the laboratory. Here we used an experimental model system of fish hosts and monogenean parasites to determine whether host sex, group size and group composition (single-sex or mixed-sex) influenced host-parasite dynamics at an individual and group level. Parasite populations reached higher densities and persisted longer in groups of fish compared with isolated hosts and reached higher densities on isolated females than on isolated males. However, individual fish within groups had similar burdens to isolated males regardless of sex, indicating that females may benefit more than males by being in a group. Relative condition was positively associated with high parasite loads for isolated males, but not for isolated females or grouped fish. No difference in parasite dynamics between mixed-sex groups and single-sex groups was detected. Overall, these findings suggest that while host sex influences dynamics on isolated fish, individual fish in groups have similar parasite burdens, regardless of sex. We believe our experimental results contribute to a mechanistic understanding of host-parasite dynamics, although we are cautious about directly extrapolating these results to other systems.

  4. Isolation of Novel Trypanosomatid, Zelonia australiensis sp. nov. (Kinetoplastida: Trypanosomatidae) Provides Support for a Gondwanan Origin of Dixenous Parasitism in the Leishmaniinae

    PubMed Central

    Barratt, Joel; Kaufer, Alexa; Peters, Bryce; Craig, Douglas; Lawrence, Andrea; Roberts, Tamalee; Lee, Rogan; McAuliffe, Gary; Stark, Damien; Ellis, John

    2017-01-01

    The genus Leishmania includes approximately 53 species, 20 of which cause human leishmaniais; a significant albeit neglected tropical disease. Leishmaniasis has afflicted humans for millennia, but how ancient is Leishmania and where did it arise? These questions have been hotly debated for decades and several theories have been proposed. One theory suggests Leishmania originated in the Palearctic, and dispersed to the New World via the Bering land bridge. Others propose that Leishmania evolved in the Neotropics. The Multiple Origins theory suggests that separation of certain Old World and New World species occurred due to the opening of the Atlantic Ocean. Some suggest that the ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia evolved on Gondwana between 90 and 140 million years ago. In the present study a detailed molecular and morphological characterisation was performed on a novel Australian trypanosomatid following its isolation in Australia’s tropics from the native black fly, Simulium (Morops) dycei Colbo, 1976. Phylogenetic analyses were conducted and confirmed this parasite as a sibling to Zelonia costaricensis, a close relative of Leishmania previously isolated from a reduviid bug in Costa Rica. Consequently, this parasite was assigned the name Zelonia australiensis sp. nov. Assuming Z. costaricensis and Z. australiensis diverged when Australia and South America became completely separated, their divergence occurred between 36 and 41 million years ago at least. Using this vicariance event as a calibration point for a phylogenetic time tree, the common ancestor of the dixenous genera Leishmania, Endotrypanum and Porcisia appeared in Gondwana approximately 91 million years ago. Ultimately, this study contributes to our understanding of trypanosomatid diversity, and of Leishmania origins by providing support for a Gondwanan origin of dixenous parasitism in the Leishmaniinae. PMID:28081121

  5. Molecular characterization of Leishmania parasites isolated from sandflies species of a zoonotic cutaneous leishmaniasis in Musiyan south west Iran.

    PubMed

    Kavarizadeh, Farzaneh; Khademvatan, Shahram; Vazirianzadeh, Babak; Feizhaddad, Mohammad Hossein; Zarean, Mehdi

    2017-03-01

    Cutaneous leishmaniasis (CL) is vector borne parasitic disease, considered as public health problem especially in border of Iran and Iraq, Dehloran County (Musian district). The aim of this study was molecular identification of Leishmania parasites in sandfly as vectors of Leishmaniasis. Totally 280 female sandflies were trapped by sticky traps from 7 rural areas of Musiyan in September-November 2012. All sandflies were identified using morphological characters of the head and abdominal terminalia. DNA was extracted from female sandflies and Leishmania was identified using PCR and sequencing. All 280 trapped sandflies were identified as Phelobotumus Papatasi and Leishmania infections were detected in 3.2 % out of 280 female sandflies. All leishmania were identified as L. major and submitted in Gene bank as: LC014642.1, LC014641.1, LC014640.1 and LC014639.1. Frequency of Phlebotomus Papatasi and infection with L. major in studied regions showed that this vector is dominant in these areas.

  6. Prevalence of a potentially lethal parasite of wading birds in natural and agricultural wetlands in south Louisiana

    USGS Publications Warehouse

    Luent, Margaret C.; Collins, Melissa; Jeske, Clinton; Leberg, Paul

    2012-01-01

    Gambusia affinis (Western Mosquitofish) were sampled from 18 sites representing marsh, forested wetlands, and agricultural wetlands in south Louisiana to determine distribution and infection parameters of Eustrongylides ignotus, a potentially lethal nematode parasite of wading birds, (n = 400 per site). Overall, prevalence of infection was 0.3%, with significantly higher prevalence in agricultural wetlands than in marshes or swamps. Our findings are similar to work in Florida suggesting parasite prevalence is higher in disturbed wetlands, and suggest that birds foraging in crayfish ponds and rice fields may be at increased risk of exposure.

  7. The occurrence of killer activity in yeasts isolated from natural habitats.

    PubMed

    Wójcik, Monika; Kordowska-Wiater, Monika

    2015-01-01

    Yeast's ability to restrict the growth and kill other yeasts, fungi and bacteria has been known for over 50 years. Killer activity was detected in yeasts deposited in the world collections or isolated from natural habitats. In this study, isolates from the forest environment, leaves of fruit trees, flower petals, cereals and frozen fruit have been screened in terms of their killer activities. Killer activity was tested on strains belonging to six yeast species: Candida, Rhodotorula, Pichia, Pachysolen, Yarrowia, Trichosporon. The reference strains were Kluyveromyces lactis Y-6682 and Kluyveromyces marxinanus Y-8281, well-known to be sensitive to yeast killer toxins. Among one hundred and two tested strains, 24 (23.5% of isolates) showed positive killer action, and 10 (9.8% of the isolates) a weak killer action against at least one sensitive reference strain. The highest killer activity was observed among isolates from forest soil and flowers.

  8. Population structure of Lactobacillus helveticus isolates from naturally fermented dairy products based on multilocus sequence typing.

    PubMed

    Sun, Zhihong; Liu, Wenjun; Song, Yuqin; Xu, Haiyan; Yu, Jie; Bilige, Menghe; Zhang, Heping; Chen, Yongfu

    2015-05-01

    Lactobacillus helveticus is an economically important lactic acid bacterium used in industrial dairy fermentation. In the present study, the population structure of 245 isolates of L. helveticus from different naturally fermented dairy products in China and Mongolia were investigated using an multilocus sequence typing scheme with 11 housekeeping genes. A total of 108 sequence types were detected, which formed 8 clonal complexes and 27 singletons. Results from Structure, SplitsTree, and ClonalFrame software analyses demonstrated the presence of 3 subpopulations in the L. helveticus isolates used in our study, namely koumiss, kurut-tarag, and panmictic lineages. Most L. helveticus isolates from particular ecological origins had specific population structures.

  9. Interacting parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  10. Isolation of Betulin and Rearrangement to Allobetulin: A Biomimetic Natural Product Synthesis

    ERIC Educational Resources Information Center

    Green, Brian; Bentley, Michael D.; Chung, Bong Y.; Lynch, Nicholas G.; Jensen, Bruce L.

    2007-01-01

    The triterpenes are a diverse class of widely distributed natural products derived from squalene. Various cyclization and subsequent rearrangement reactions produce many complex structural types. These compounds frequently display a wide divergence of biological properties. For example the pentacyclic triterpene, betulin, is isolated from white…

  11. Isolation of anacardic acid from natural cashew nut shell liquid (CNSL) using supercritical carbon dioxide.

    PubMed

    Philip, Joseph Y N; Da Cruz Francisco, José; Dey, Estera S; Buchweishaija, Joseph; Mkayula, Lupituko L; Ye, Lei

    2008-10-22

    Solvent extracted cashew nut shell liquid (CNSL), conventionally known as natural CNSL, is a mixture of several alkenyl phenols. One of these alkenyl phenols is anacardic acid, which is present at the highest concentration. In view of anticipated industrial applications of anacardic acid, the objective of this work was to isolate anacardic acid from natural CNSL by supercritical carbon dioxide (scCO 2). In this study, the solubility data for natural CNSL in scCO 2 under a range of operating conditions of pressure (100, 200, and 300 bar), temperature (40 and 50 degrees C), and CO 2 flow rate (5, 10, and 15 g min (-1)) were established. The best scCO 2 working conditions were found to be 50 degrees C and 300 bar at a flow rate of 5 g min (-1) CO 2. Using 3 g of sample (CNSL/solid adsorbent = 1/2) under these scCO 2 conditions, it was possible to quantitatively isolate high purity anacardic acid from crude natural CNSL (82% of total anacardic acid) within 150 min. The anacardic acid isolated by scCO 2 was analyzed by different spectroscopic techniques (UV-vis, FT-IR, and (1)H NMR) and HPLC analysis, indicating that the anacardic acid isolated by scCO 2 has better quality than that obtained through a conventional method involving several chemical conversion steps.

  12. Intestinal parasites and genotyping of Giardia duodenalis in children: first report of genotype B in isolates from human clinical samples in Mexico.

    PubMed

    Torres-Romero, Julio César; Euan-Canto, Antonio de Jesus; Benito-González, Namibya; Padilla-Montaño, Nayely; Huchin-Chan, Claribel; Lara-Riegos, Julio; Cedillo-Rivera, Roberto

    2014-06-01

    Giardia duodenalis is one of the most prevalent enteroparasites in children. This parasite produces several clinical manifestations. The aim of this study was to determine the prevalence of genotypes of G. duodenalis causing infection in a region of southeastern Mexico. G. duodenalis cysts were isolated (33/429) from stool samples of children and molecular genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, targeting the triosephosphate isomerase ( tpi ) and glutamate dehydrogenase ( gdh ) genes. The tpi gene was amplified in all of the cyst samples, either for assemblage A (27 samples) or assemblage B (6 samples). RFLP analysis classified the 27 tpi -A amplicons in assemblage A, subgenotype I. Samples classified as assemblage B were further analysed using PCR-RFLP of the gdh gene and identified as assemblage B, subgenotype III. To our knowledge, this is the first report of assemblage B of G. duodenalis in human clinical samples from Mexico.

  13. [Analysis on Research Projects Supported by the National Natural Science Foundation of China at the National Institute of Parasitic Diseases during 2003-2013].

    PubMed

    Zhou, Xiao-jun; Zheng, Bin; Yi, Feng-yun; Xiong, Yan-hong; Zhang, Min-qi

    2015-04-01

    The data of the National Natural Science Foundation (NSFC) projests obtained by the National Institute of Parasitic Diseases (NIPD), Chinese Center for Disease Control and Prevention (China CDC) during 2003-2013 were collected from internet-based science information system of NSFC, and NSFC search tool of Dingxiang Garden (http://nsfc.biomart.cn/). The number of funded projects, their subject classification and approved amount were analyzed, and compared with the other institutes of China CDC. Furthermore, the rationalization proposals were given in order to enhance the level of foundation management in the future.

  14. Patch Size and Isolation Predict Plant Species Density in a Naturally Fragmented Forest

    PubMed Central

    Munguía-Rosas, Miguel A.; Montiel, Salvador

    2014-01-01

    Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest). We surveyed the vascular flora (except lianas and epiphytes) of 19 forest patches using five belt transects (50×4 m each) per patch (area sampled per patch = 0.1 ha). As predicted, plant species density was positively associated (logarithmically) with patch size and negatively associated (linearly) with patch isolation (distance to the nearest patch). Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation), however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented. PMID:25347818

  15. Multilocus sequence and microsatellite identification of intra-specific hybrids and ancestor-like donors among natural Ethiopian isolates of Leishmania donovani.

    PubMed

    Gelanew, Tesfaye; Hailu, Asrat; Schőnian, Gabriele; Lewis, Michael D; Miles, Michael A; Yeo, Matthew

    2014-09-01

    Protozoan parasites of the genus Leishmania (Kinetoplastida: Trypanosomatidae) cause widespread and devastating human diseases. Visceral leishmaniasis is endemic in Ethiopia where it has also been responsible for fatal epidemics. It is postulated that genetic exchange in Leishmania has implications for heterosis (hybrid vigour), spread of virulent strains, resistance to chemotherapeutics, and exploitation of different hosts and vectors. Here we analyse 11 natural Ethiopian Leishmania donovani isolates consisting of four putative hybrids, seven parent-like isolates and over 90 derived biological clones. We apply a novel combination of high resolution multilocus microsatellite typing (five loci) and multilocus sequence typing (four loci) that together distinguish parent-like and hybrid L. donovani strains. Results indicate that the four isolates (and their associated biological clones) are genetic hybrids, not the results of mixed infections, each possessing heterozygous markers consistent with inheritance of divergent alleles from genetically distinct Ethiopian L. donovani lineages. The allelic profiles of the putative hybrids may have arisen from a single hybridisation event followed by inbreeding or gene conversion, or alternatively from two or more hybridisation events. Mitochondrial sequencing showed uniparental maxicircle inheritance for all of the hybrids, each possessing a single mitochondrial genotype. Fluorescence activated cell sorting analysis of DNA content demonstrated that all hybrids and their associated clones were diploid. Together the data imply that intra-specific genetic exchange is a recurrent feature of natural L. donovani populations, with substantial implications for the phyloepidemiology of Leishmania.

  16. Stability of pollination services decreases with isolation from natural areas despite honey bee visits.

    PubMed

    Garibaldi, Lucas A; Steffan-Dewenter, Ingolf; Kremen, Claire; Morales, Juan M; Bommarco, Riccardo; Cunningham, Saul A; Carvalheiro, Luísa G; Chacoff, Natacha P; Dudenhöffer, Jan H; Greenleaf, Sarah S; Holzschuh, Andrea; Isaacs, Rufus; Krewenka, Kristin; Mandelik, Yael; Mayfield, Margaret M; Morandin, Lora A; Potts, Simon G; Ricketts, Taylor H; Szentgyörgyi, Hajnalka; Viana, Blandina F; Westphal, Catrin; Winfree, Rachael; Klein, Alexandra M

    2011-10-01

    Sustainable agricultural landscapes by definition provide high magnitude and stability of ecosystem services, biodiversity and crop productivity. However, few studies have considered landscape effects on the stability of ecosystem services. We tested whether isolation from florally diverse natural and semi-natural areas reduces the spatial and temporal stability of flower-visitor richness and pollination services in crop fields. We synthesised data from 29 studies with contrasting biomes, crop species and pollinator communities. Stability of flower-visitor richness, visitation rate (all insects except honey bees) and fruit set all decreased with distance from natural areas. At 1 km from adjacent natural areas, spatial stability decreased by 25, 16 and 9% for richness, visitation and fruit set, respectively, while temporal stability decreased by 39% for richness and 13% for visitation. Mean richness, visitation and fruit set also decreased with isolation, by 34, 27 and 16% at 1 km respectively. In contrast, honey bee visitation did not change with isolation and represented > 25% of crop visits in 21 studies. Therefore, wild pollinators are relevant for crop productivity and stability even when honey bees are abundant. Policies to preserve and restore natural areas in agricultural landscapes should enhance levels and reliability of pollination services.

  17. Effects of natural and sexual selection on adaptive population divergence and premating isolation in a damselfly.

    PubMed

    Svensson, Erik I; Eroukhmanoff, Fabrice; Friberg, Magne

    2006-06-01

    The relative strength of different types of directional selection has seldom been compared directly in natural populations. A recent meta-analysis of phenotypic selection studies in natural populations suggested that directional sexual selection may be stronger in magnitude than directional natural selection, although this pattern may have partly been confounded by the different time scales over which selection was estimated. Knowledge about the strength of different types of selection is of general interest for understanding how selective forces affect adaptive population divergence and how they may influence speciation. We studied divergent selection on morphology in parapatric, natural damselfly (Calopteryx splendens) populations. Sexual selection was stronger than natural selection measured on the same traits, irrespective of the time scale over which sexual selection was measured. Visualization of the fitness surfaces indicated that population divergence in overall morphology is more strongly influenced by divergent sexual selection rather than natural selection. Courtship success of experimental immigrant males was lower than that of resident males, indicating incipient sexual isolation between these populations. We conclude that current and strong sexual selection promotes adaptive population divergence in this species and that premating sexual isolation may have arisen as a correlated response to divergent sexual selection. Our results highlight the importance of sexual selection, rather than natural selection in the adaptive radiation of odonates, and supports previous suggestions that divergent sexual selection promotes speciation in this group.

  18. Contributions of natural and sexual selection to the evolution of premating reproductive isolation: a research agenda.

    PubMed

    Safran, Rebecca J; Scordato, Elizabeth S C; Symes, Laurel B; Rodríguez, Rafael L; Mendelson, Tamra C

    2013-11-01

    Speciation by divergent natural selection is well supported. However, the role of sexual selection in speciation is less well understood due to disagreement about whether sexual selection is a mechanism of evolution separate from natural selection, as well as confusion about various models and tests of sexual selection. Here, we outline how sexual selection and natural selection are different mechanisms of evolutionary change, and suggest that this distinction is critical when analyzing the role of sexual selection in speciation. Furthermore, we clarify models of sexual selection with respect to their interaction with ecology and natural selection. In doing so, we outline a research agenda for testing hypotheses about the relative significance of divergent sexual and natural selection in the evolution of reproductive isolation.

  19. Bacteria isolated from the different developmental stages and larval organs of the obligate parasitic fly, Wohlfahrtia magnifica (Diptera: Sarcophagidae).

    PubMed

    Tóth, E M; Hell, E; Kovács, G; Borsodi, A K; Márialigeti, K

    2006-01-01

    Wohlfahrtia magnifica (Diptera: Sarcophagidae) is the major myiasis-causing fly species in the whole of Eurasia for most important domestic animals. The aim of the present work was to obtain data on the culturable bacteria isolated under aerobic conditions from this fly: bacteria were isolated from all developmental stages (larvae, pupa, and imago) of Wohlfahrtia magnifica, and the third-stage larval organs were also sampled. To determine the possible antagonistic effects between the dominant bacterial groups, an antibiosis assay was carried out. Plating and isolation of bacteria was performed by classical microbiological methods. Characterization of the isolated strains was carried out via a polyphasic approach; classical phenotypic tests, chemotaxonomical examinations, and 16S rDNA sequence analyses were also applied. In the case of maggot macerate samples, members of the family Enterobacteriaceae were characteristic. Members of a new genus (Schineria) belonging to the gamma subdivision of proteobacteria were also isolated. According to our data, the shifts in the Schineria and Proteus populations within the larvae are strongly influenced by their interactions with each other and among the members of the family Enterobacteriaceae. The pupa and imago samples contained several other Gram-negative bacteria (Stenotrophomonas, Brevundimonas, etc.). Among Gram-positive bacteria, in all maggot macerate samples, members of the genus Bacillus and the Arthrobacter-Micrococcus group of actinobacteria were dominant (neither of them was a producer or sensitive to the compounds of other microorganisms), and bacteria related to the genus Corynebacterium were also found. From the larvae Aureobacterium liquefaciens and Enterococcus faecalis were isolated, and from the pupae Dietzia maris and Enterococcus faecalis. In the samples of third-stage larval organs, the dominant groups were the same as in the third-stage larval macerate sample; however, several additional genera

  20. First isolation of natural cyanamide as a possible allelochemical from hairy vetch Vicia villosa.

    PubMed

    Kamo, Tsunashi; Hiradate, Syuntaro; Fujii, Yoshiharu

    2003-02-01

    Cyanamide was isolated from the leaves and stems of hairy vetch (Vicia villosa), guided by plant growth inhibitory activity against lettuce (Lectuca sativa) seedlings. A large proportion of the inhibitory activity in the crude extract was explained by the presence of cyanamide, suggesting it to be a possible allelochemical in this species. The amount in a 9-day-old seedling, which had been grown without nutrients, reached approx. 40 times that of a nongerminated seed, demonstrating cyanamide biosynthesis in the seedlings. This is the first report on the isolation of a possible allelochemical from hairy vetch and also of the finding of cyanamide as a natural product.

  1. Drug Resistance in Natural Isolates of Leishmania donovani s.l. Promastigotes Is Dependent of Pgp170 Expression

    PubMed Central

    Mazeris, Apostolos; Koutala, Eleni; Vlahou, Antonia; Papadogiorgaki, Sevasti; Antoniou, Maria

    2013-01-01

    Resistance of pathogens to drugs is a growing concern regarding many diseases. Parasites like Leishmania, Plasmodium and Entamoeba histolytica; and neoplastic cells, present the multidrug-resistant phenotype rendering chemotherapy ineffective. The acquired resistance of Leishmania to antimony has generated intense research on the mechanisms involved but the question has not yet been resolved. To test the hypothesis that drug efflux in Leishmania, as measured by flow cytometry using the fluorescent dye Rhodamine-123, is largely dependent on the number of efflux pumps an isolate can express, the amount of Pgp 170 molecules was assessed in ten field isolates (5 “resistant” and 5 “susceptible”) using: Western Blotting, Confocal and Transmission Electron Microscopy, and proteomics. Their survival after exposure to three antileishmanial drugs, in vitro, was evaluated and clinical data were compared to the in vitro results. All isolates were resistant to Glucantime but susceptible to Miltefosine, whilst Amphotericin B was more effective on the “susceptible” isolates. The MDR gene, expressing the transmembrane efflux pump Pgp 170, appears to play a key role in the phenomenon of drug resistance. When “susceptible” versus “resistant” parasites were compared, it was shown that the higher the number of Pgp 170 molecules the higher the Rhodamine-123 efflux from the parasite body and, when exposed to the drug, the number of efflux pumps increased. However, the rate of this increase was not linear and it is possible that there is a maximum number of Pgp 170 molecules an isolate can express. Nevertheless, the phenomenon is a complex one and other factors and proteins are involved in which the HSP-70 group proteins, detected in the “resistant” isolates, may play a significant role. PMID:23776486

  2. Parasites and marine invasions

    USGS Publications Warehouse

    Torchin, M.E.; Lafferty, K.D.; Kuris, A.M.

    2002-01-01

    Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer parasites in their introduced range compared to their native range. Parasites are ubiquitous and pervasive in marine systems, yet their role in marine invasions is relatively unexplored. Although data on parasites of marine organisms exist, the extent to which parasites can mediate marine invasions, or the extent to which invasive parasites and pathogens are responsible for infecting or potentially decimating native marine species have not been examined. In this review, we present a theoretical framework to model invasion success and examine the evidence for a relationship between parasite presence and the success of introduced marine species. For this, we compare the prevalence and species richness of parasites in several introduced populations of marine species with populations where they are native. We also discuss the potential impacts of introduced marine parasites on native ecosystems.

  3. Bioactive Volatiles from an Endophytic Daldinia cf. concentrica Isolate Affect the Viability of the Plant Parasitic Nematode Meloidogyne javanica

    PubMed Central

    Braun Miyara, Sigal; Ezra, David

    2016-01-01

    Plant-parasitic nematodes form one of the largest sources of biotic stress imposed on plants, and are very difficult to control; among them are the obligate parasites, the sedentary root-knot nematodes (RKNs)–Meloidogyne spp.–which are extremely polyphagous and exploit a very wide range of hosts. Endophytic fungi are organisms that spend most of their life cycle within plant tissue without causing visible damage to the host plant. Many endophytes secrete specialized metabolites and/or emit volatile organic compounds (VOCs) that exhibit biological activity. Recently, we demonstrated that the endophytic fungus Daldinia cf. concentrica secrets biologically active VOCs. Here we examined the ability of the fungus and its VOCs to control the RKN M. javanica both in vitro and greenhouse experiments. The D. cf. concentrica VOCs showed bionematicidal activity against the second-stage juveniles (J2s) of M. javanica. We found that exposure of J2s to fungal volatiles caused 67% reduction in viability, and that application of a synthetic volatile mixture (SVM), comprising 3-methyl-1-butanol, (±)-2-methyl-1-butanol, 4-heptanone, and isoamyl acetate, in volumetric ratio of 1:1:2:1 further reduced J2s viability by 99%. We demonstrated that, although each of the four VOCs significantly reduced the viability of J2s relative to the control, only 4-heptanone elicited the same effect as the whole mixture, with nematicidal activity of 90% reduction in viability of the J2s. Study of the effect of the SVM on egg hatching demonstrated that it decreased eggs hatching by 87%. Finally, application of the SVM to soil inoculated with M. javanica eggs or J2s prior to planting susceptible tomato plants resulted in a significantly reduced galling index and fewer eggs produced on each root system, with no effect on root weight. Thus, D. cf. concentrica and/or SVM based on fungal VOCs may be considered as a novel alternative approach to controlling the RKN M. javanica. PMID:27997626

  4. Comprehensive isolation of natural organic matter from water for spectral characterizations and reactivity testing

    USGS Publications Warehouse

    Leenheer, J.A.; Croue, J.-P.; Benjamin, M.; Korshin, G.V.; Hwang, C.J.; Bruchet, A.; Aiken, G.R.

    2000-01-01

    A variety of approaches were tested to comprehensively isolate natural organic matter (NOM) from water. For waters with high NOM concentrations such as the Suwannee River, Georgia, approaches that used combinations of membrane concentrations, evaporative concentrations, and adsorption on nonionic XAD resins, ion exchange resins and iron oxide coated sand isolated over 90% of the NOM. However, for waters with low NOM concentrations, losses of half of the NOM were common and desalting of NOM isolates was a problem. A new comprehensive approach was devised and tested on the Seine River, France in which 100 L of filtered water was sodium softened by ion exchange and vacuum evaporated to 100 mL. Colloids (32% of the NOM) were isolated using a 3,500 Dalton membrane by dialysis against 0.1 M HCl and 0.2 M HF to remove salts and silica. On the membrane permeate, hydrophobic NOM (42%) was isolated using XAD-8 resin and hydrophilic NOM (26%) was isolated using a variety of selective desalting precipitations. The colloid fraction was characterized by IR and NMR spectroscopy as N-acetylamino sugars. ?? 2000 American Chemical Society.

  5. Relative importance of habitat area and isolation for bird occurrence patterns in a naturally patchy landscape

    USGS Publications Warehouse

    Wilson, T.L.; Johnson, E.J.; Bissonette, J.A.

    2009-01-01

    There is debate among ecologists about whether total habitat area or patch arrangement contributes most to population and/or community responses to fragmented or patchy landscapes. We tested the relative effects of patch area and isolation for predicting bird occurrence in a naturally patchy landscape in the Bear River Mountains of Northern Utah, USA. We selected focal patches (mountain meadows) ranging in elevation from 1,920 to 2,860 m and in size from 0.6 to 182 ha. Breeding birds were sampled in each focal meadow during the summers of 2003 and 2004 using variable-distance point transects. Logistic regression and likelihood-based model selection were used to determine the relationship between likelihood of occurrence of three bird species (Brewer's sparrow, vesper sparrow, and white-crowned sparrow) and area, isolation, and proximity metrics. We used model weights and model-averaged confidence intervals to assess the importance of each predictor variable. Plots of area versus isolation were used to evaluate complex relationships between the variables. We found that meadow area was the most important variable for explaining occurrence for two species, and that isolation was the most important for the other. We also found that the absolute distance was more appropriate for evaluating isolation responses than was the species-specific proximity metric. Our findings add clarity to the debate between ecologists regarding the relative importance of area and isolation in species responses to patchy landscapes.

  6. A likelihood-based approach for assessment of extra-pair paternity and conspecific brood parasitism in natural populations

    USGS Publications Warehouse

    Lemons, Patrick R.; Marshall, T.C.; McCloskey, Sarah E.; Sethi, S.A.; Schmutz, Joel A.; Sedinger, James S.

    2015-01-01

    Genotypes are frequently used to assess alternative reproductive strategies such as extra-pair paternity and conspecific brood parasitism in wild populations. However, such analyses are vulnerable to genotyping error or molecular artifacts that can bias results. For example, when using multilocus microsatellite data, a mismatch at a single locus, suggesting the offspring was not directly related to its putative parents, can occur quite commonly even when the offspring is truly related. Some recent studies have advocated an ad-hoc rule that offspring must differ at more than one locus in order to conclude that they are not directly related. While this reduces the frequency with which true offspring are identified as not directly related young, it also introduces bias in the opposite direction, wherein not directly related young are categorized as true offspring. More importantly, it ignores the additional information on allele frequencies which would reduce overall bias. In this study, we present a novel technique for assessing extra-pair paternity and conspecific brood parasitism using a likelihood-based approach in a new version of program cervus. We test the suitability of the technique by applying it to a simulated data set and then present an example to demonstrate its influence on the estimation of alternative reproductive strategies.

  7. The first isolation of enantiomeric and meso-zeaxanthin in nature.

    PubMed

    Maoka, T; Arai, A; Shimizu, M; Matsuno, T

    1986-01-01

    Racemic mixtures of (3RS, 3'RS)-zeaxanthin were separated into the three optical isomers, (3R, 3'R)-zeaxanthin (1), (3R,3'S;meso)-zeaxanthin (2) and (3S,3'S)-zeaxanthin (3), by converting to their corresponding dibenzoates and by using HPLC on an optical resolution column Sumipax OA-2000. According to this procedure, it has been shown that only (1) is isolated from higher plants, shellfish, starfish, sea squirt, sea cucumber and then examined; on the other hand (1), (2) and (3) are isolated from zeaxanthin fraction of shrimp, fish and turtle examined. This is the first isolation of enantiomeric and meso-zeaxanthin in nature.

  8. Complete genome sequence of Bacillus licheniformis BL-09, a probiotic strain isolated from naturally fermented congee.

    PubMed

    Gao, Pengfei; Yao, Guoqiang; Bao, Weichen; Li, Jing; Zhang, Heping; Zhang, Wenyi

    2015-07-20

    Bacillus licheniformis BL-09 is a probiotic strain isolated from naturally fermented congee in Inner Mongolia of China. The genome of this strain contains a 4.39 Mb circular chromosome with an average GC content of 45.9%. The analysis of the genome revealed two gene clusters that are related to the peptide biosynthesis. The available genetic information of these peptides makes it possible to construct an improved strain for the industrial production of antimicrobial agents.

  9. Polymorphisms in K13, pfcrt, pfmdr1, pfdhfr, and pfdhps in parasites isolated from symptomatic malaria patients in Burkina Faso

    PubMed Central

    Somé, Anyirékun Fabrice; Sorgho, Hermann; Zongo, Issaka; Bazié, Thomas; Nikiéma, Frédéric; Sawadogo, Amadé; Zongo, Moussa; Compaoré, Yves-Daniel; Ouédraogo, Jean-Bosco

    2016-01-01

    Background: The emergence of resistance to artemisinin derivatives in western Cambodia is threatening to revert the recent advances made toward global malaria control and elimination. Known resistance-mediating polymorphisms in the K13, pfcrt, pfmdr1, pfdhfr, and pfdhps genes are of greatest importance for monitoring the spread of antimalarial drug resistance. Methods: Samples for the present study were collected from 244 patients with uncomplicated malaria in health centers of Bobo-Dioulasso, Burkina Faso. Blood sample was collected on filter paper before the subject received any treatment. The parasite DNA was then extracted and amplified by Polymerase Chain Reaction (PCR) to evaluate the prevalence of polymorphism of pfcrtK76T, pfmdr1 (N86Y, Y184F), and pfdhps (A437G, K540E). The K13 gene polymorphism was analyzed by nested PCR followed by sequencing. Results: The overall results showed 2.26% (5/221) of K13 synonymous mutant alleles (two C469C, one Y493Y, one G496G, and one V589V), 24.78%, 19.58%, 68.75%, 60.9%, 53.7%, 63.8%, and 64.28%, respectively, for mutant pfcrt 76T, pfmdr1-86Y, pfmdr1-184F, pfdhfr51I, pfdhfr59R, pfdhfr108N, and pfdhps 437G. We did not report any mutation at codon 540 of pfdhps. Conclusion: These results provide baseline prevalence of known drug resistance polymorphisms and suggest that artemisinin combination therapies may retain good efficacy in the treatment of uncomplicated malaria in Burkina Faso. PMID:28004634

  10. Trihalomethanes formed from natural organic matter isolates: Using isotopic and compositional data to help understand sources

    USGS Publications Warehouse

    Bergamaschi, B.A.; Fram, M.S.; Fujii, R.; Aiken, G.R.; Kendall, C.; Silva, S.R.

    2000-01-01

    Over 20 million people drink water from the Sacramento-San Joaquin Delta despite problematic levels of natural organic matter (NOM) and bromide in Delta water, which can form trihalomethanes (THMs) during the treatment process. It is widely believed that NOM released from Delta peat islands is a substantial contributor to the pool of THM precursors present in Delta waters. Dissolved NOM was isolated from samples collected at five channel sites within the Sacramento-San Joaquin Rivers and Delta, California, USA, and from a peat island agricultural drain. To help understand the sources of THM precursors, samples were analyzed to determine their chemical and isotopic composition, their propensity to form THMs, and the isotopic composition of the THMs. The chemical composition of the isolates was quite variable, as indicated by significant differences in carbon-13 nuclear magnetic resonance spectra and carbon-to-nitrogen concentration ratios. The lowest propensity to form THMs per unit of dissolved organic carbon was observed in the peat island agricultural drain isolate, even though it possessed the highest fraction of aromatic material and the highest specific ultraviolet absorbance. Changes in the chemical and isotopic composition of the isolates and the isotopic composition of the THMs suggest that the source of the THMs precursors was different between samples and between isolates. The pattern of variability in compositional and isotopic data for these samples was not consistent with simple mixing of river- and peat-derived organic material.

  11. Parasitic Colitis

    PubMed Central

    Hechenbleikner, Elizabeth M.; McQuade, Jennifer A.

    2015-01-01

    Over one billion people worldwide harbor intestinal parasites. Parasitic intestinal infections have a predilection for developing countries due to overcrowding and poor sanitation but are also found in developed nations, such as the United States, particularly in immigrants or in the setting of sporadic outbreaks. Although the majority of people are asymptomatically colonized with parasites, the clinical presentation can range from mild abdominal discomfort or diarrhea to serious complications, such as perforation or bleeding. Protozoa and helminths (worms) are the two major classes of intestinal parasites. Protozoal intestinal infections include cryptosporidiosis, cystoisosporiasis, cyclosporiasis, balantidiasis, giardiasis, amebiasis, and Chagas disease, while helminth infections include ascariasis, trichuriasis, strongyloidiasis, enterobiasis, and schistosomiasis. Intestinal parasites are predominantly small intestine pathogens but the large intestine is also frequently involved. This article highlights important aspects of parasitic infections of the colon including epidemiology, transmission, symptoms, and diagnostic methods as well as appropriate medical and surgical treatment. PMID:26034403

  12. Chimpanzee malaria parasites related to Plasmodium ovale in Africa.

    PubMed

    Duval, Linda; Nerrienet, Eric; Rousset, Dominique; Sadeuh Mba, Serge Alain; Houze, Sandrine; Fourment, Mathieu; Le Bras, Jacques; Robert, Vincent; Ariey, Frederic

    2009-01-01

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

  13. Chimpanzee Malaria Parasites Related to Plasmodium ovale in Africa

    PubMed Central

    Duval, Linda; Nerrienet, Eric; Rousset, Dominique; Sadeuh Mba, Serge Alain; Houze, Sandrine; Fourment, Mathieu; Le Bras, Jacques; Robert, Vincent; Ariey, Frederic

    2009-01-01

    Since the 1970's, the diversity of Plasmodium parasites in African great apes has been neglected. Surprisingly, P. reichenowi, a chimpanzee parasite, is the only such parasite to have been molecularly characterized. This parasite is closely phylogenetically related to P. falciparum, the principal cause of the greatest malaria burden in humans. Studies of malaria parasites from anthropoid primates may provide relevant phylogenetic information, improving our understanding of the origin and evolutionary history of human malaria species. In this study, we screened 130 DNA samples from chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) from Cameroon for Plasmodium infection, using cytochrome b molecular tools. Two chimpanzees from the subspecies Pan t. troglodytes presented single infections with Plasmodium strains molecularly related to the human malaria parasite P. ovale. These chimpanzee parasites and 13 human strains of P. ovale originated from a various sites in Africa and Asia were characterized using cytochrome b and cytochrome c oxidase 1 mitochondrial partial genes and nuclear ldh partial gene. Consistent with previous findings, two genetically distinct types of P. ovale, classical and variant, were observed in the human population from a variety of geographical locations. One chimpanzee Plasmodium strain was genetically identical, on all three markers tested, to variant P. ovale type. The other chimpanzee Plasmodium strain was different from P. ovale strains isolated from humans. This study provides the first evidence of possibility of natural cross-species exchange of P. ovale between humans and chimpanzees of the subspecies Pan t. troglodytes. PMID:19436742

  14. "Aqua-space", a new headspace method for isolation of natural floral aromas using humidified air as a carrier gas.

    PubMed

    Ishikawa, Masashi; Honda, Tsutomu; Fujita, Akira; Kurobayashi, Yoshiko; Kitahara, Takeshi

    2004-02-01

    A new method called "Aqua-space" was developed for the isolation of the natural fragrances of plants. Living flowers were enclosed in a space under simulated natural conditions, and humidified air was pumped into the space as a fragrance carrier. In a comparison among three isolation methods, i.e., Aqua-space, headspace, and solvent extraction, the Aqua-space method proved to be the most effective in retaining natural fragrances with abundant oxygenated components key to floral fragrances.

  15. Zebrafish Bioassay-Guided Natural Product Discovery: Isolation of Angiogenesis Inhibitors from East African Medicinal Plants

    PubMed Central

    Crawford, Alexander D.; Liekens, Sandra; Kamuhabwa, Appolinary R.; Maes, Jan; Munck, Sebastian; Busson, Roger; Rozenski, Jef; Esguerra, Camila V.; de Witte, Peter A. M.

    2011-01-01

    Natural products represent a significant reservoir of unexplored chemical diversity for early-stage drug discovery. The identification of lead compounds of natural origin would benefit from therapeutically relevant bioassays capable of facilitating the isolation of bioactive molecules from multi-constituent extracts. Towards this end, we developed an in vivo bioassay-guided isolation approach for natural product discovery that combines bioactivity screening in zebrafish embryos with rapid fractionation by analytical thin-layer chromatography (TLC) and initial structural elucidation by high-resolution electrospray mass spectrometry (HRESIMS). Bioactivity screening of East African medicinal plant extracts using fli-1:EGFP transgenic zebrafish embryos identified Oxygonum sinuatum and Plectranthus barbatus as inhibiting vascular development. Zebrafish bioassay-guided fractionation identified the active components of these plants as emodin, an inhibitor of the protein kinase CK2, and coleon A lactone, a rare abietane diterpenoid with no previously described bioactivity. Both emodin and coleon A lactone inhibited mammalian endothelial cell proliferation, migration, and tube formation in vitro, as well as angiogenesis in the chick chorioallantoic membrane (CAM) assay. These results suggest that the combination of zebrafish bioassays with analytical chromatography methods is an effective strategy for the rapid identification of bioactive natural products. PMID:21379387

  16. Millipede Defensive Compounds Are a Double-Edged Sword: Natural History of the Millipede-Parasitic Genus Myriophora Brown (Diptera: Phoridae).

    PubMed

    Hash, John M; Millar, Jocelyn G; Heraty, John M; Harwood, James F; Brown, Brian V

    2017-02-01

    Toxic defensive secretions produced by millipedes in the orders Julida, Spirobolida, Spirostreptida, and Polydesmida are highly repellent to most vertebrate and invertebrate natural enemies, but a few insects have evolved mechanisms to overcome these defenses. We demonstrate that highly specialized parasitic phorid flies in the species-rich genus Myriophora use volatile millipede defensive compounds as kairomones for host location. Of the two predominant quinone components in the defensive blend of juliform millipedes, 2-methoxy-3-methyl-1,4-benzoquinone alone was sufficient to attract adult flies of both sexes; however, a combination of 2-methoxy-3-methyl-1,4-benzoquinone and 2-methyl-1,4-benzoquinone increased attractiveness nearly threefold. We further discuss oviposition behavior, adult and larval feeding habits, life history parameters, and the potential competitive interactions between phorid flies in the genus Myriophora and other millipede-associated insects.

  17. PCR diagnosis of benzimidazole-susceptibility or -resistance in natural populations of the small ruminant parasite, Teladorsagia circumcincta.

    PubMed

    Elard, L; Cabaret, J; Humbert, J F

    1999-01-14

    We have developed a new molecular tool for the diagnosis of the benzimidazole (BZ)-susceptibility or resistance in Teladorsagia circumcincta a nematode parasite of small ruminants. This tool is based on the use of the PCR and allows the genotyping of resistant (rr) or susceptible (rS and SS) adult worms or larvae. By using four primers in the same reaction mixture, worms can be genotyped in regard to the mutation on the residue 200 (phenylalanine to tyrosine) of the beta-tubulin which is implicated in BZ resistance. A very high proportion of homozygous SS (Phe/Phe) individuals characterized the BZ susceptible populations, whereas a variable proportion of homozygous rr (Tyr/Tyr) individuals characterized the BZ resistant populations. A positive correlation was observed between the LD50 estimated by egg hatch assay, and the proportion of mutant homozygous individuals rr (Tyr/Tyr). Our PCR method allows the rapid genotyping of numerous worms and permits the detection of the first resistant individuals in a worm population.

  18. Zymogram patterns of Naegleria spp isolated from natural water sources in Taling Chan district, Bangkok.

    PubMed

    Tiewcharoen, Supathra; Komalamisra, Narumon; Junnu, Virach

    2004-06-01

    A genetic approach was cited for species detection of the ameba genus Naegleria using allozyme electrophoresis to characterize the trophozoite stage of three strains of Naegleria fowleri isolated from patients with primary amebic meningoencephalitis, five thermophilic (45 degrees C) Naegleria spp isolated from natural water sources in the Taling Chan district, and a reference control strain, Naegleria fowleri CDC VO 3081. Isoenzymes of ameba whole-cell extracts were analyzed by vertical polyacrylamide slab gel electrophoresis to determine whether there was any correlation between different strains of the ameba. The results showed that five out of fifteen enzymes; aldehyde oxidase (ALDOX), aldolase (ALD), a-glycerophosphate dehydrogenase (a-GPDH), xanthine dehydrogenase (XDH), and glutamate oxaloacetate transaminase (GOT), were undetectable in the pathogenic strains, while the other enzymes; esterase (EST), fumerase (FUM), glucose-6-phosphate dehydrogenase (G-6-PDH), glucose phosphate isomerase (GPI), isocitate dehydrogenase (IDH), lactate dehydrogenase (LDH), leucine aminopeptidase (LAP), malic enzyme (ME), glucose phosphomutase (GPM), and malate dehydrogenase (MDH), were detected. Naegleria fowleri strains were biochemically the most homogeneous. They showed intraspecific isoenzyme variation that allowed them to be grouped. In contrast, the allozyme patterns (EST 1-7, IDH) of Naegleria spp isolated from the environment showed interspecific isoenzyme variations from the pathogenic Naegleria strain. In conclusion, this study recognized the zymograms of the Naegleria fowleri strains were heterogenically different from the thermophilic 45 degrees C Naegleria spp isolated from the environment.

  19. Suppression of plant parasitic nematodes in the chinampa agricultural soils.

    PubMed

    Zuckerman, B M; Dicklow, M B; Coles, G C; Garcia-E, R; Marban-Mendoza, N

    1989-06-01

    Soil from the chinampa agricultural system in the Valley of Mexico suppressed damage by plant-parasitic nematodes to tomatoes and beans in greenhouse and growth chamber trials. Sterilization of the chinampa soil resulted in a loss of the suppressive effect, thereby indicating that one or more biotic factors were responsible for the low incidence of nematode damage. Nine organisms were isolated from chinampa soil, which showed antinematodal properties in culture. Naturally occurring populations of plant-parasitic nematodes were of lower incidence in chinampa soil than in Chapingo soil.

  20. Parasitic Diseases

    MedlinePlus

    ... You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not. Parasites range in size from tiny, ... Contaminated water supplies can lead to Giardia infections. Cats can ...

  1. Occurrence and linkage between secreted insecticidal toxins in natural isolates of Bacillus thuringiensis.

    PubMed

    Espinasse, Sylvain; Chaufaux, Josette; Buisson, Christophe; Perchat, Stéphane; Gohar, Michel; Bourguet, Denis; Sanchis, Vincent

    2003-12-01

    Little is known about the occurrence and linkage between secreted insecticidal virulence factors in natural populations of Bacillus thuringiensis (Bt). We carried out a survey of 392 Bt strains isolated from various samples originating from 31 countries. The toxicity profile of the culture supernatants of these strains was determined individually against Anthonomus grandis (Coleoptera) and Spodoptera littoralis (Lepidoptera). We analyzed beta-exotoxin I production and searched for the genes encoding Vip1-2, Vip3, and Cry1I toxins in 125 of these strains. Our results showed that these insecticidal toxins were widespread in Bt but that their distribution was nonrandom, with significant linkage observed between vip3 and cry1I and between vip1-2 and beta-exotoxin I. Strains producing significant amounts of beta-exotoxin I were more frequently isolated from invertebrate samples than from dust, water, soil, or plant samples.

  2. Genetic diversity and population structure of Lactobacillus delbrueckii subspecies bulgaricus isolated from naturally fermented dairy foods

    PubMed Central

    Song, Yuqin; Sun, Zhihong; Guo, Chenyi; Wu, Yarong; Liu, Wenjun; Yu, Jie; Menghe, Bilige; Yang, Ruifu; Zhang, Heping

    2016-01-01

    Lactobacillus delbrueckii subsp. bulgaricus is one of the most widely used starter culture strains in industrial fermented dairy manufacture. It is also common in naturally fermented dairy foods made using traditional methods. The subsp. bulgaricus strains found in naturally fermented foods may be useful for improving current industrial starter cultures; however, little is known regarding its genetic diversity and population structure. Here, a collection of 298 L. delbrueckii strains from naturally fermented products in Mongolia, Russia, and West China was analyzed by multi-locus sequence typing based on eight conserved genes. The 251 confirmed subsp. bulgaricus strains produced 106 unique sequence types, the majority of which were assigned to five clonal complexes (CCs). The geographical distribution of CCs was uneven, with CC1 dominated by Mongolian and Russian isolates, and CC2–CC5 isolates exclusively from Xinjiang, China. Population structure analysis suggested six lineages, L1–L6, with various homologous recombination rates. Although L2–L5 were mainly restricted within specific regions, strains belonging to L1 and L6 were observed in diverse regions, suggesting historical transmission events. These results greatly enhance our knowledge of the population diversity of subsp. bulgaricus strains, and suggest that strains from CC1 and L4 may be useful as starter strains in industrial fermentation. PMID:26940047

  3. Expression of IFN-gamma, TNF-alpha, IL-10 and TGF-beta in lymph nodes associates with parasite load and clinical form of disease in dogs naturally infected with Leishmania (Leishmania) chagasi.

    PubMed

    Alves, Cíntia F; de Amorim, Izabela F G; Moura, Eliane P; Ribeiro, Raul R; Alves, Cibele F; Michalick, Marilene S; Kalapothakis, Evanguedes; Bruna-Romero, Oscar; Tafuri, Wagner L; Teixeira, Mauro M; Melo, Maria N

    2009-04-15

    American visceral leishmaniasis is a zoonosis of the New World. Dogs are the main reservoir of the disease and there is much interest in the understanding of mechanisms implicated in protection against canine infection. Nevertheless, most studies in dogs have not been carried out in organs that are targets of infection. This work is first to report the profile of cytokines and parasite burdens, as determined by real-time PCR, in the lymph nodes of dogs naturally infected with Leishmania chagasi. With this purpose, 18 mongrel dogs were divided in three groups: control non-infected dogs (n=6) and naturally infected animals with L. chagasi, asymptomatic (n=6) and symptomatic (n=6). Parasite burden in lymph nodes was 73-fold greater in symptomatic than asymptomatic animals. Prescapular lymph nodes of asymptomatic dogs had the highest expression of IFN-gamma and TNF-alpha and low parasite burden, indicating that these cytokines play a role in protection against infection. Highest expression of IL-10 and TGF-beta and high parasite burden were observed in symptomatic dogs, suggesting a role for these cytokines in the progression of disease. Hence, the balance of expression of IFN-gamma and TNF-alpha (protective) and IL-10 and TGF-beta (disease progression) in lymph nodes determine parasite burden and clinical expression in naturally infected dogs.

  4. Isolation and characterization of lactic acid bacteria strains with ornithine producing capacity from natural sea salt.

    PubMed

    Yu, Jin-Ju; Oh, Suk-Heung

    2010-08-01

    Two lactic acid bacteria (LAB) having ornithine-producing capacity were isolated from Korean natural sea salt. They were Gram-positive, short rod-type bacteria, and able to grow anaerobically with CO(2) production. The isolates grew well on MRS broth at 30-37 degrees C and a pH of 6.5-8.0. The optimum temperature and pH for growth are 37 degrees C and pH 7.0. The isolates fermented D-ribose, D-galactose, D-lactose, D-maltose, Dcellobiose, D-tagatose, D-trehalose, sucrose, D-melezitose, gentiobiose, D-glucose but not D-melibiose, inositol, and L-sorbose. The 16S rDNA sequences of the two isolates showed 99.5% and 99.6% homology with the Weissella koreensis S5623 16S rDNA (Access no. AY035891). They were accordingly identified and named as Weissella koreensis MS1-3 and Weissella koreensis MS1-14, and produced intracellular ornithine at levels of 72 mg/100 g cell F.W. and 105 mg/100 g cell F.W. and extracellular ornithine at levels of 4.5 mg/100 ml and 4.6 mg/100 ml medium, respectively, by culturing in MRS broth supplemented with 1% arginine. High cell growth was maintained in MRS broth with a NaCl concentration of 0-6%. These results show for the first time that Korean natural sea salts contain lactic acid bacteria Weissella koreensis strains having ornithine producing capacity.

  5. Induction of apoptosis by zerumbone isolated from Zingiber zerumbet (L.) Smith in protozoan parasite Leishmania donovani due to oxidative stress.

    PubMed

    Mukherjee, Debarati; Singh, Chingakham Brajakishor; Dey, Somaditya; Mandal, Supratim; Ghosh, Joydip; Mallick, Suvadip; Hussain, Aabid; Swapana, Ningombam; Ross, Samir Anis; Pal, Chiranjib

    2016-01-01

    In the present context of emergence of resistance aligned with the conventional anti-leishmanial drugs and occasional treatment failure compelled us to continue the search for replaceable therapeutic leads against Leishmania infection. Various ginger spices of the Zingiberaceae family are widely used as spices, flavouring agents, and medicines in Southeast Asia because of their unique flavour as well as due to their medicinal properties. Zerumbone, a natural component of Zingiber zerumbet (L.) Smith, has been studied for its pharmacological potential as antiulcer, antioxidant, anticancer, and antimicrobial. In this study, we have shown that zerumbone could induce ROS mediated apoptosis in Leishmania donovani promastigotes and also found effective in reducing intracellular amastigotes in infected-macrophages. We emphasized the potential of zerumbone to be employed in the development of new therapeutic drugs against L. donovani infection and provided the basis for future research on the application of transitional medicinal plants.

  6. Large-scale isolation and cytotoxicity of extracellular vesicles derived from activated human natural killer cells

    PubMed Central

    Jong, Ambrose Y.; Wu, Chun-Hua; Li, Jingbo; Sun, Jianping; Fabbri, Muller; Wayne, Alan S.; Seeger, Robert C.

    2017-01-01

    ABSTRACT Extracellular vesicles (EVs) have been the focus of great interest, as they appear to be involved in numerous important cellular processes. They deliver bioactive macromolecules such as proteins, lipids, and nucleic acids, allowing intercellular communication in multicellular organisms. EVs are secreted by all cell types, including immune cells such as natural killer cells (NK), and they may play important roles in the immune system. Currently, a large-scale procedure to obtain functional NK EVs is lacking, limiting their use clinically. In this report, we present a simple, robust, and cost-effective method to isolate a large quantity of NK EVs. After propagating and activating NK cells ex vivo and then incubating them in exosome-free medium for 48 h, EVs were isolated using a polymer precipitation method. The isolated vesicles contain the tetraspanin CD63, an EV marker, and associated proteins (fibronectin), but are devoid of cytochrome C, a cytoplasmic marker. Nanoparticle tracking analysis showed a size distribution between 100 and 200 nm while transmission electron microscopy imaging displayed vesicles with an oval shape and comparable sizes, fulfilling the definition of EV. Importantly, isolated EV fractions were cytotoxic against cancer cells. Furthermore, our results demonstrate for the first time that isolated activated NK (aNK) cell EVs contain the cytotoxic proteins perforin, granulysin, and granzymes A and B, incorporated from the aNK cells. Activation of caspase -3, -7 and -9 was detected in cancer cells incubated with aNK EVs, and caspase inhibitors blocked aNK EV-induced cytotoxicity, suggesting that aNK EVs activate caspase pathways in target cells. The ability to isolate functional aNK EVs on a large scale may lead to new clinical applications. Abbreviations: NK: natural killer cells; activated NK (aNK) cells; EVs: extracellular vesicles; ALL: acute lymphoblastic leukaemia; aAPC: artificial antigen-presenting cell; TEM: transmission

  7. Genomic signatures of geographic isolation and natural selection in coral reef fishes.

    PubMed

    Gaither, Michelle R; Bernal, Moisés A; Coleman, Richard R; Bowen, Brian W; Jones, Shelley A; Simison, W Brian; Rocha, Luiz A

    2015-04-01

    The drivers of speciation remain among the most controversial topics in evolutionary biology. Initially, Darwin emphasized natural selection as a primary mechanism of speciation, but the architects of the modern synthesis largely abandoned that view in favour of divergence by geographic isolation. The balance between selection and isolation is still at the forefront of the evolutionary debate, especially for the world's tropical oceans where biodiversity is high, but isolating barriers are few. Here, we identify the drivers of speciation in Pacific reef fishes of the genus Acanthurus by comparative genome scans of two peripheral populations that split from a large Central-West Pacific lineage at roughly the same time. Mitochondrial sequences indicate that populations in the Hawaiian Archipelago and the Marquesas Islands became isolated approximately 0.5 Ma. The Hawaiian lineage is morphologically indistinguishable from the widespread Pacific form, but the Marquesan form is recognized as a distinct species that occupies an unusual tropical ecosystem characterized by upwelling, turbidity, temperature fluctuations, algal blooms and little coral cover. An analysis of 3737 SNPs reveals a strong signal of selection at the Marquesas, with 59 loci under disruptive selection including an opsin Rh2 locus. While both the Hawaiian and Marquesan populations indicate signals of drift, the former shows a weak signal of selection that is comparable with populations in the Central-West Pacific. This contrast between closely related lineages reveals one population diverging due primarily to geographic isolation and genetic drift, and the other achieving taxonomic species status under the influence of selection.

  8. Measure Guideline: Combustion Safety for Natural Draft Appliances Through Appliance Zone Isolation

    SciTech Connect

    Fitzgerald, J.; Bohac, D.

    2014-04-01

    This measure guideline covers how to assess and carry out the isolation of natural draft combustion appliances from the conditioned space of low-rise residential buildings. It deals with combustion appliances located either within the living space in enclosed closets or side rooms or outside the living space in an adjacent area like an attic or garage. This subset of houses does not require comprehensive combustion safety tests and simplified prescriptive procedures can be used to address safety concerns. This allows residential energy retrofit contractors inexperienced in advanced combustion safety testing to effectively address combustion safety issues and allow energy retrofits including tightening and changes to distribution and ventilation systems to proceed.

  9. Natural hydrazine-containing compounds: Biosynthesis, isolation, biological activities and synthesis.

    PubMed

    Le Goff, Géraldine; Ouazzani, Jamal

    2014-12-01

    Hydrazine, hydrazone and hydrazide derivatives are nitrogen-nitrogen bond containing compounds. Such molecules are relatively scarce in nature and have been isolated from plants, marine organisms and microorganisms. These compounds exhibit remarkable structural diversity and relevant biological activities. The enzymes involved in the formation of the N-N bond are still unknown, but many lines of evidence support the involvement of N-nitrosation and N-hydroxylation activating steps. Beside the challenging N-N bond, N-acylases catalyzing the C-N bond formation contribute to the chemical diversity of N-N-containing natural products (N2NP). This review examines the state of knowledge regarding the biosynthesis of N2NP, for which only two biosynthetic gene clusters have been investigated. Biological properties and chemical synthesis of hydrazines, hydrazones and hydrazides are also reported.

  10. Complete Annotated Genome Sequences of Three Campylobacter jejuni Strains Isolated from Naturally Colonized Farm-Raised Chickens

    PubMed Central

    Taveirne, Michael E.; Dunham, Drew T.; Perault, Andrew; Beauchamp, Jessica M.; Huynh, Steven; Parker, Craig T.

    2017-01-01

    ABSTRACT Campylobacter jejuni is a leading cause of bacterially derived foodborne illness. Human illness is commonly associated with the handling and consumption of contaminated poultry products. Three C. jejuni strains were isolated from cecal contents of three different naturally colonized farm-raised chickens. The complete genomes of these three isolates are presented here. PMID:28126931

  11. Internal parasites of reptiles.

    PubMed

    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.

  12. Geographical and meteorological factors associated with isolation of Listeria species in New York State produce production and natural environments.

    PubMed

    Chapin, Travis K; Nightingale, Kendra K; Worobo, Randy W; Wiedmann, Martin; Strawn, Laura K

    2014-11-01

    Listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. The presence of Listeria spp. has been suggested to be a marker for Listeria monocytogenes contamination. Therefore, a study was conducted to (i) determine the prevalence and diversity of Listeria spp. in produce production and natural environments and (ii) identify geographical and/or meteorological factors that affect the isolation of Listeria spp. in these environments. These data were also used to evaluate Listeria spp. as index organisms for L. monocytogenes in produce production environments. Environmental samples collected from produce production (n = 588) and natural (n = 734) environments in New York State were microbiologically analyzed to detect and isolate Listeria spp. The prevalence of Listeria spp. was approximately 33 and 34% for samples obtained from natural environments and produce production, respectively. Co-isolation of L. monocytogenes and at least one other species of Listeria in a given sample was recorded for 3 and 9% of samples from natural environments and produce production, respectively. Soil moisture and proximity to water and pastures were highly associated with isolation of Listeria spp. in produce production environments, while elevation, study site, and proximity to pastures were highly associated with isolation of Listeria spp. in natural environments, as determined by randomForest models. These data show that Listeria spp. were prevalent in both agricultural and nonagricultural environments and that geographical and meteorological factors associated with isolation of Listeria spp. were considerably different between the two environments.

  13. Bacillus species isolated from tungrymbai and bekang, naturally fermented soybean foods of India.

    PubMed

    Chettri, Rajen; Tamang, Jyoti Prakash

    2015-03-16

    Tungrymbai and bekang are naturally fermented soybean foods commonly consumed in Meghalaya and Mizoram states of India. A total of 39 samples of tungrymbai and 43 samples of bekang were collected from different villages and markets of Meghalaya and Mizoram, respectively and were analysed for microbial load. In both tungrymbai and bekang, the average population of Bacillus spp. was 8.2±0.1 log cfu/g. A total of 428 isolates of Bacillus were isolated from tungrymbai (211) and bekang (217) for detailed identification. On the basis of a combination of phenotypic and molecular characterisation using ARDRA, ITS-PCR and RAPD-PCR techniques, species of Bacillus isolated from tungrymbai were identified as Bacillus licheniformis (25.5%), Bacillus pumilus (19.5%) and Bacillus subtilis (55%), and species of Bacillus from bekang were Bacillus brevis (2%), Bacillus circulans (7.5%), Bacillus coagulans (6.5%), B. licheniformis (16.5%), B. pumilus (9.1%), Bacillus sphaericus (4.6%), B. subtilis (51.8%), and Lysinibacillus fusiformis (2%). The most dominant bacterium in both products was B. subtilis.

  14. Enterotoxin production in natural isolates of Bacillaceae outside the Bacillus cereus group.

    PubMed

    Phelps, Rebecca J; McKillip, John L

    2002-06-01

    Thirty-nine Bacillus strains obtained from a variety of environmental and food sources were screened by PCR for the presence of five gene targets (hblC, hblD, hblA, nheA, and nheB) in two enterotoxin operons (HBL and NHE) traditionally harbored by Bacillus cereus. Seven isolates exhibited a positive signal for at least three of the five possible targets, including Bacillus amyloliquefaciens, B. cereus, Bacillus circulans, Bacillus lentimorbis, Bacillus pasteurii, and Bacillus thuringiensis subsp. kurstaki. PCR amplicons were confirmed by restriction enzyme digest patterns compared to a positive control strain. Enterotoxin gene expression of each strain grown in a model food system (skim milk) was monitored by gene-specific reverse transcription-PCR and confirmed with the Oxoid RPLA and Tecra BDE commercial kits. Lecithinase production was noted on egg yolk-polymyxin B agar for all strains except B. lentimorbis, whereas discontinuous beta hemolysis was exhibited by all seven isolates grown on 5% sheep blood agar plates. The results of this study confirm the presence of enterotoxin genes in natural isolates of Bacillus spp. outside the B. cereus group and the ability of these strains to produce toxins in a model food system under aerated conditions at 32 degrees C.

  15. Production of conjugated linoleic acids by Lactobacillus plantarum strains isolated from naturally fermented Chinese pickles*

    PubMed Central

    Liu, Pei; Shen, Sheng-rong; Ruan, Hui; Zhou, Qian; Ma, Liu-liu; He, Guo-qing

    2011-01-01

    Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid (CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion) at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 µg/ml of linoleic acid (LA). Compared to other strains, L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 µg/ml. This strain converted about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable between 100 to 600 µg/ml LA levels in the medium, it dropped sharply at 1000 µg/ml. Taken together, the lp15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles. PMID:22042657

  16. Fatty acid profiles in Leishmania spp. isolates with natural resistance to nitric oxide and trivalent antimony.

    PubMed

    de Azevedo, Alana Freire; Dutra, Jorge Luís de Lisboa; Santos, Micheli Luize Barbosa; Santos, Darlisson de Alexandria; Alves, Péricles Barreto; de Moura, Tatiana Rodrigues; de Almeida, Roque Pacheco; Fernandes, Marcelo Ferreira; Scher, Ricardo; Fernandes, Roberta Pereira Miranda

    2014-01-01

    Fatty acids, especially those from phospholipids (PLFA), are essential membrane components that are present in relatively constant proportions in biological membranes under natural conditions. However, under harmful growth conditions, such as diseases, environmental changes, and chemical exposure, the fatty acid proportions might vary. If such changes could be identified and revealed to be specific for adverse situations, they could be used as biomarkers. Such biomarkers could facilitate the identification of virulence and resistance mechanisms to particular chemotherapeutic agents. Therefore, specific biomarkers could lead to better therapeutic decisions that would, in turn, enhance treatment effectiveness. The objective of this study was to compare the fatty acid profiles of trivalent antimony and nitric oxide (NO)-resistant and -sensitive Leishmania chagasi and Leishmania amazonensis isolates. Fatty acid methyl esters (FAMEs) were obtained from total lipids (MIDI), ester-linked lipids (ELFA), and ester-linked phospholipids (PLFA). FAMEs were analyzed by chromatography and mass spectrometry. Species- or resistance-associated differences in FAME profiles were assessed by nonmetric multidimensional scaling, multiresponse permutation procedures, and indicator species analyses. The isolate groups had different MIDI-FAME profiles. However, neither the ELFA nor PLFA profiles differed between the sensitive and resistant isolates. Levels of the fatty acid 18:1 Δ9c were increased in sensitive isolates (p < 0,001), whereas the fatty acid 20:4 Δ5,8,11,14 showed the opposite trend (p < 0.01). We conclude that these two fatty acids are potential biomarkers for NO and antimony resistance in L. chagasi and L. amazonensis and that they could be helpful in therapeutic diagnoses.

  17. Isolation of microorganisms involved in reduction of crystalline iron(III) oxides in natural environments

    PubMed Central

    Hori, Tomoyuki; Aoyagi, Tomo; Itoh, Hideomi; Narihiro, Takashi; Oikawa, Azusa; Suzuki, Kiyofumi; Ogata, Atsushi; Friedrich, Michael W.; Conrad, Ralf; Kamagata, Yoichi

    2015-01-01

    Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing microorganisms in soils and sediments. Firstly, iron reducers were enriched and other untargeted eutrophs were depleted by 2-years successive culture on a crystalline ferric iron oxide (i.e., goethite, lepidocrocite, hematite, or magnetite) as electron acceptor. Fifty-eight out of 136 incubation conditions allowed the continued existence of microorganisms as confirmed by PCR amplification. High-throughput Illumina sequencing and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures on each of the ferric iron oxides contained bacteria belonging to the Deltaproteobacteria (mainly Geobacteraceae), followed by Firmicutes and Chloroflexi, which also comprised most of the operational taxonomic units (OTUs) identified. Venn diagrams indicated that the core OTUs enriched with all of the iron oxides were dominant in the Geobacteraceae while each type of iron oxides supplemented selectively enriched specific OTUs in the other phylogenetic groups. Secondly, 38 enrichment cultures including novel microorganisms were transferred to soluble-iron(III) containing media in order to stimulate the proliferation of the enriched iron reducers. Through extinction dilution-culture and single colony isolation, six strains within the Deltaproteobacteria were finally obtained; five strains belonged to the genus Geobacter and one strain to Pelobacter. The 16S rRNA genes of these isolates were 94.8–98.1% identical in sequence to cultured relatives. All the isolates were able to grow on acetate and ferric iron but their physiological characteristics differed considerably in

  18. Ungulate malaria parasites

    PubMed Central

    Templeton, Thomas J.; Asada, Masahito; Jiratanh, Montakan; Ishikawa, Sohta A.; Tiawsirisup, Sonthaya; Sivakumar, Thillaiampalam; Namangala, Boniface; Takeda, Mika; Mohkaew, Kingdao; Ngamjituea, Supawan; Inoue, Noboru; Sugimoto, Chihiro; Inagaki, Yuji; Suzuki, Yasuhiko; Yokoyama, Naoaki; Kaewthamasorn, Morakot; Kaneko, Osamu

    2016-01-01

    Haemosporida parasites of even-toed ungulates are diverse and globally distributed, but since their discovery in 1913 their characterization has relied exclusively on microscopy-based descriptions. In order to bring molecular approaches to bear on the identity and evolutionary relationships of ungulate malaria parasites, we conducted Plasmodium cytb-specific nested PCR surveys using blood from water buffalo in Vietnam and Thailand, and goats in Zambia. We found that Plasmodium is readily detectable from water buffalo in these countries, indicating that buffalo Plasmodium is distributed in a wider region than India, which is the only area in which buffalo Plasmodium has been reported. Two types (I and II) of Plasmodium sequences were identified from water buffalo and a third type (III) was isolated from goat. Morphology of the parasite was confirmed in Giemsa-reagent stained blood smears for the Type I sample. Complete mitochondrial DNA sequences were isolated and used to infer a phylogeny in which ungulate malaria parasites form a monophyletic clade within the Haemosporida, and branch prior to the clade containing bird, lizard and other mammalian Plasmodium. Thus it is likely that host switching of Plasmodium from birds to mammals occurred multiple times, with a switch to ungulates independently from other mammalian Plasmodium. PMID:26996979

  19. Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro.

    PubMed

    Jardim, A C G; Igloi, Z; Shimizu, J F; Santos, V A F F M; Felippe, L G; Mazzeu, B F; Amako, Y; Furlan, M; Harris, M; Rahal, P

    2015-03-01

    Compounds extracted from plants can provide an alternative approach to new therapies. They present characteristics such as high chemical diversity, lower cost of production and milder or inexistent side effects compared with conventional treatment. The Brazilian flora represents a vast, largely untapped, resource of potential antiviral compounds. In this study, we investigate the antiviral effects of a panel of natural compounds isolated from Brazilian plants species on hepatitis C virus (HCV) genome replication. To do this we used firefly luciferase-based HCV sub-genomic replicons of genotypes 2a (JFH-1), 1b and 3a and the compounds were assessed for their effects on both HCV replication and cellular toxicity. Initial screening of compounds was performed using the maximum non-toxic concentration and 4 compounds that exhibited a useful therapeutic index (favourable ratio of cytotoxicity to antiviral potency) were selected for extra analysis. The compounds APS (EC50=2.3μM), a natural alkaloid isolated from Maytrenus ilicifolia, and the lignans 3(∗)43 (EC50=4.0μM), 3(∗)20 (EC50=8.2μM) and 5(∗)362 (EC50=38.9μM) from Peperomia blanda dramatically inhibited HCV replication as judged by reductions in luciferase activity and HCV protein expression in both the subgenomic and infectious systems. We further show that these compounds are active against a daclatasvir resistance mutant subgenomic replicon. Consistent with inhibition of genome replication, production of infectious JFH-1 virus was significantly reduced by all 4 compounds. These data are the first description of Brazilian natural compounds possessing anti-HCV activity and further analyses are being performed in order to investigate the mode of action of those compounds.

  20. Isolation of iodide-oxidizing bacteria from iodide-rich natural gas brines and seawaters.

    PubMed

    Amachi, Seigo; Muramatsu, Yasuyuki; Akiyama, Yukako; Miyazaki, Kazumi; Yoshiki, Sayaka; Hanada, Satoshi; Kamagata, Yoichi; Ban-nai, Tadaaki; Shinoyama, Hirofumi; Fujii, Takaaki

    2005-05-01

    Iodide-oxidizing bacteria (IOB), which oxidize iodide (I-) to molecular iodine (I2), were isolated from iodide-rich (63 microM to 1.2 mM) natural gas brine waters collected from several locations. Agar media containing iodide and starch were prepared, and brine waters were spread directly on the media. The IOB, which appeared as purple colonies, were obtained from 28 of the 44 brine waters. The population sizes of IOB in the brines were 10(2) to 10(5) colony-forming units (CFU) mL(-1). However, IOB were not detected in natural seawaters and terrestrial soils (fewer than 10 CFU mL(-1) and 10(2) CFU g wet weight of soils(-1), respectively). Interestingly, after the enrichment with 1 mM iodide, IOB were found in 6 of the 8 seawaters with population sizes of 10(3) to 10(5) CFU mL(-1). 16S rDNA sequencing and phylogenetic analyses showed that the IOB strains are divided into two groups within the alpha-subclass of the Proteobacteria. One of the groups was phylogenetically most closely related to Roseovarius tolerans with sequence similarities between 94% and 98%. The other group was most closely related to Rhodothalassium salexigens, although the sequence similarities were relatively low (89% to 91%). The iodide-oxidizing reaction by IOB was mediated by an extracellular enzyme protein that requires oxygen. Radiotracer experiments showed that IOB produce not only I2 but also volatile organic iodine, which were identified as diiodomethane (CH2I2) and chloroiodomethane (CH2ClI). These results indicate that at least two types of IOB are distributed in the environment, and that they are preferentially isolated in environments in which iodide levels are very high. It is possible that IOB oxidize iodide in the natural environment, and they could significantly contribute to the biogeochemical cycling of iodine.

  1. Patterns of host-parasite adaptation in three populations of monarch butterflies infected with a naturally occurring protozoan disease: virulence, resistance, and tolerance.

    PubMed

    Sternberg, Eleanore D; Li, Hui; Wang, Rebecca; Gowler, Camden; de Roode, Jacobus C

    2013-12-01

    Many studies have used host-parasite systems to study local adaptation, but few of these studies have found unequivocal evidence for adaptation. One potential reason is that most studies have focused on limited measures of host and parasite fitness that are generally assumed to be under negative frequency-dependent selection. We have used reciprocal cross-infection experiments to test for local adaptation in Hawaiian, south Floridian, and eastern North American populations of monarch butterflies and their protozoan parasites. Sympatric host-parasite combinations did not result in greater host or parasite fitness, as would be expected under coevolutionary dynamics driven by negative frequency-dependent selection. Instead, we found that Hawaiian hosts were more resistant and carried more infective and virulent parasites, which is consistent with theoretical predictions for virulence evolution and coevolutionary arms race dynamics. We also found that Hawaiian hosts were more tolerant, particularly of Hawaiian parasites, indicating that increased resistance does not preclude increased tolerance within a population and that hosts may be more tolerant of local parasites. We did not find a similar pattern in the south Floridian or eastern populations, possibly because host-parasite adaptation occurs within the context of a greater ecological community.

  2. Parasites, emerging disease and wildlife conservation.

    PubMed

    Thompson, R C A; Lymbery, A J; Smith, A

    2010-08-15

    In this review some emerging issues of parasite infections in wildlife, particularly in Australia, are considered. We discuss the importance of understanding parasite biodiversity in wildlife in terms of conservation, the role of wildlife as reservoirs of parasite infection, and the role of parasites within the broader context of the ecosystem. Using a number of parasite species, the value of undertaking longitudinal surveillance in natural systems using non-invasive sampling and molecular tools to characterise infectious agents is illustrated in terms of wildlife health, parasite biodiversity and ecology.

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

    PubMed

    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.

  4. A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates.

    PubMed

    Maurice, Patricia A; Pullin, Michael J; Cabaniss, Stephen E; Zhou, Qunhui; Namjesnik-Dejanovic, Ksenija; Aiken, George R

    2002-05-01

    This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (rho), absorbance at 280 nm normalized to moles C (epsilon280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO > XAD-8 > RFW > XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between

  5. A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates

    USGS Publications Warehouse

    Maurice, P.A.; Pullin, M.J.; Cabaniss, S.E.; Zhou, Q.; Namjesnik-Dejanovic, K.; Aiken, G.R.

    2002-01-01

    This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (??), absorbance at 280nm normalized to moles C (??280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO>XAD-8>RFW>XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between XAD and RO

  6. Isolation and screening of microalgae from natural habitats in the midwestern United States of America for biomass and biodiesel sources

    PubMed Central

    Lee, Keesoo; Eisterhold, Megan L.; Rindi, Fabio; Palanisami, Swaminathan; Nam, Paul K.

    2014-01-01

    Native species of microalgae were isolated from natural water bodies in the Midwestern United States of America and were screened for the ultimate goal of mass cultivation in Missouri and the surrounding states, and for their potential as biomass and biodiesel sources. A number of different nutrient media recipes were utilized to isolate the maximum number of colonies from each field samples. These nutrient recipes were modified in order to optimize the isolation and growth dynamics of specific colonies. All of the isolates were categorized based on the morphological appearance of the culture and the microscopic cellular appearance of the isolated colonies. Isolates included many common green microalgae and cyanobacteria. Lipid content was determined for selected strains that demonstrated relatively quick growth. Scenedesmus sp. that demonstrated the high growth rate, resistance to invasion, and contained sufficient amounts of lipid was investigated for its potential as a sustainable biomass and biodiesel feedstocks. PMID:25097410

  7. Grammomys surdaster, the Natural Host for Plasmodium berghei Parasites, as a Model to Study Whole-Organism Vaccines against Malaria.

    PubMed

    Conteh, Solomon; Anderson, Charles; Lambert, Lynn; Orr-Gonzalez, Sachy; Herrod, Jessica; Robbins, Yvette L; Carter, Dariyen; Bin Shamamba Karhemere, Stomy; Pyana, Pati; Büscher, Philippe; Duffy, Patrick E

    2017-01-23

    Inbred mice are commonly used to test candidate malaria vaccines, but have been unreliable for predicting efficacy in humans. To establish a more rigorous animal model, we acquired African woodland thicket rats of the genus Grammomys, the natural hosts for Plasmodium berghei Thicket rats were acquired and identified as Grammomys surdaster by skull and teeth measurements and mitochondrial DNA genotyping. Herein, we demonstrate that thicket rats are highly susceptible to infection by P berghei, and moderately susceptible to Plasmodium yoelii and Plasmodium chabaudi: 1-2 infected mosquito bites or 25-100 sporozoites administered by intravenous injection consistently resulted in patent parasitemia with P. berghei, and resulted in patent parasitemia with P. yoelii and P. chabaudi strains for at least 50% of animals. We then assessed efficacy of whole-organism vaccines to induce sterile immunity, and compared the thicket rat model to conventional mouse models. Using P. berghei ANKA radiation-attenuated sporozoites, and P. berghei ANKA and P. yoelii chemoprophylaxis vaccination approaches, we found that standard doses of vaccine sufficient to protect laboratory mice for long duration against malaria challenge, are insufficient to protect thicket rats, which require higher doses of vaccine to achieve even short-term sterile immunity. Thicket rats may offer a more stringent and pertinent model for evaluating whole-organism vaccines.

  8. Isolation and characterization of (15Z)-lycopene thermally generated from a natural source.

    PubMed

    Takehara, Munenori; Kuwa, Takahiro; Inoue, Yoshinori; Kitamura, Chitoshi; Honda, Masaki

    2015-11-06

    (15Z)-Lycopene was prepared by thermal isomerization of (all-E)-lycopene derived from tomatoes, and isolated by using a series of chromatographies. The fine red crystalline powder of (15Z)-lycopene was obtained from 556 mg of (all-E)-lycopene with a yield of 0.6 mg (purity: reversed-phase HPLC, 97.2%; normal-phase HPLC, ≥99.9%), and (1)H and (13)C NMR spectra of the isomer were fully assigned. More refined computational analyses that considered differences in the energy levels of the conformers involved in isomerization have also determined the stabilities of (15Z)-lycopene and other geometric isomers, along with the activation energies during isomerization from the all-E form. The fine control of conditions for HPLC separation and an advanced theoretical insight into geometric isomerization have led to the discovery of the 15Z-isomer generated from a natural source.

  9. A mutable X{sup Z} chromosome isolated from a natural population of Drosophila melanogaster

    SciTech Connect

    Yurchenko, N.N.; Zakharov, I.K.

    1995-07-01

    In 1986, a mutable X{sup Z} chromosome, in which mutation at genes yellow, white, and singed were recorded, was isolated from a natural population of Drosophila melanogaster from Zaporozh`e. Visible mutations in the region garnet-forked were also detected. Mutations appeared at a rate of about 10{sup {minus}4} and were probably postmeiotic. Cytological analysis showed that two types of inversions occurred independently in X{sup Z} chromosome. Specific features of this chromosome are hypermutability of the white locus (the mutation rate was approximately 10{sup {minus}3}) and a hot spot for chromosomal rearrangements in the terminal segment of the X chromosome. 9 refs., 2 figs., 2 tabs.

  10. Detection and isolation of Salmonella from naturally contaminated alfalfa seeds following an outbreak investigation.

    PubMed

    Inami, G B; Moler, S E

    1999-06-01

    Naturally contaminated alfalfa seeds, epidemiologically linked to foodborne disease outbreaks in Oregon and British Columbia, were tested for the presence of Salmonella. Ten sample units from the suspected lot were sprouted and grown for 4 days. After enrichment of the grown sprouts, an enzyme immunoassay (EIA) and culture method (modified procedure of the Food and Drug Administration Bacteriological Analytical Manual) were used for the detection and isolation of Salmonella. Four of the 10 sample units were positive with the EIA; however, 5 of the 10 sample units were culture positive (four were positive for Salmonella serotype Newport and a fifth was positive for Salmonella serotype Albany and serotype Schwarzengrund). The positive alfalfa seed sample units were further tested after shredding, soaking, and washing before culturing. Results suggest that sprouting and shredding methods may yield greater detection and recovery rates of Salmonella, but more research with a larger sample size is warranted.

  11. Environment-influenced expression of polygene mutations isolated from a natural population of Drosophila melanogaster.

    PubMed

    Thompson, J N; Jeung, M; Thoday, J M

    1998-01-01

    Quantitative trait loci (QTLs) affecting sternopleural bristle number in Drosophila melanogaster have been mapped using phenotypic markers and progeny testing. The loci were found on four of the third chromosomes isolated from a natural population. All four loci showed large effects at the standard 25 degrees C culture temperature, but they responded in different ways when developmental temperature was lowered or raised. These data support the hypothesis that genotype x environment interactions have important influences on polygene expression, and some loci might be silent, or phenotypically neutral, under some conditions but play a large phenotypic role under others. Thus, a full cataloging of the loci contributing to mutational variance for QTLs cannot be done at just a single, controlled environmental condition.

  12. Changes in natural resistence of immune system at volunteers-verifiers in long-term isolation

    NASA Astrophysics Data System (ADS)

    Ponomarev, Sergey; Boris, Morukov; Antropova, Eugeniya; Rykova, Marina; Berendeeva, Tatyana

    It's known that the immune system is exposed to adverse influence during the space flight. For the purpose of finding-out the character of similar changes at six volunteers-verifiers at the age from 25 till 40 years in experiment with long-term (105 twenty-four hours) isolation using the flow cytometry research was spent an estimation of some key parameters characteriz-ing a condition of natural resistance system, such as phagocytic activity, expression of pattern recognition receptors (TLR 1, TLR 2, TLR 3, TLR 4, TLR 6), adhesion molecules (CD54, CD24, CD11b, CD18), a Fc-receptor (CD 16), a scavenger-receptor (CD36), a mannose re-ceptor (CD206). A significant increase of phagocytic activity for monocyte and granulocyte populations in comparison with the background values remaining and after exit from isolation chamber was observed. Strengthening of CD11/CD18 receptor expression which is a marker of early activation of phagocytes was as well observed. Decrease of CD 206 monocyte receptor also confirms a high level of phagocyte activity. Dynamics of TLR1, TLR2, TLR3, TLR4, TLR6 CD54, CD24, CD 16 expression on monocytes and granulocytes surface considerably changed throughout the experiment and indicates the strongly pronounced individual wavy character. Such a dynamics of changes can reflect a number of the adaptive changes directed on mainte-nance regular functioning of immunity, however the further stay in isolation chamber is capable to lead to hyperactivation, and then to an exhaustion of immune system reserve possibilities which lead to increase the infection and autoimmune diseases.

  13. Photometric hydroxyl radical scavenging analysis of standard natural organic matter isolates.

    PubMed

    Donham, J E; Rosenfeldt, E J; Wigginton, K R

    2014-04-01

    Hydroxyl radical (˙OH) scavenging reaction rate constants of standard natural organic matter (NOM) isolates (k˙OH,NOM) were measured with a rapid background scavenging method, to expand the dataset of published k˙OH,NOM values. The proposed method relies on ˙OH generation with a simple UV/H₂O₂ AOP-based system. The associated decay of a ˙OH probe compound is monitored with a field-deployable spectrophotometer and k˙OH,NOM is determined through competition kinetics. The resulting k˙OH,NOM values for the six NOM standard isolates ranged from 1.02 (±0.10) × 10(8) MC(-1) s(-1) for Suwannee River Fulvic Acid I Standard to 2.03 (±0.12) × 10(8) MC(-1) s(-1) for Pony Lake Fulvic Acid Reference NOM, which is within the range reported with more elaborate and time-consuming k˙OH,NOM methods. A slight correlation between nitrogen content and scavenging rate constant was evident while no significant correlation between k˙OH,NOM and atomic composition, carbon structure, weight-average molecular weight, UV absorbance (SUVA₂₅₄), or fluorescence index (FI) was observed. Overall, the results demonstrate that k˙OH,NOM can be rapidly assessed in NOM isolate samples. The results suggest that this type of rapid field-deployable spectrophotometric method may minimize the need for expensive and time-consuming background scavenging methods, and for models that predict k˙OH,NOM based on other NOM characteristics.

  14. [Biological characterization of three natural isolates of the porcine rubulavirus (Mexico)].

    PubMed

    Borraz-Argüello, María del Tránsito; Santos-López, Gerardo; Vallejo-Ruiz, Verónica; Herrera-Camacho, Irma; Reyes-Leyva, Julio

    2008-06-01

    Biological characterization of three natural isolates of the porcine rubulavirus (Mexico). Porcine rubulavirus (PoRV) produces a neurological and reproductive syndrome in pigs called the blue-eye disease, known only from Mexico. Several isolates were grouped by the main symptoms presented during outbreaks: a) neurotropic in piglets, (b) broadly neurotropic in piglets and gonadotropic in adults, and (c) gonadotropic in adults. We studied some biological properties of three strains, which fall in one of each virus group: La Piedad Michoacán (LPM) and Producci6n Animal Cerdos 1 (PAC1) and 3 (PAC3), respectively. The analyzed viral properties are mainly related with the trans-membrane hemagglutinin-neuraminidase (HN) and fusion (F) proteins, such as cytopathic effect, hemolysis, hemagglutinating (HA) and neuraminidase (NA) activities. In the infection assays PAC1 strain presented the highest fusogenicity level; however, the most cytolytic strain was PAC3. In addition, HA and NA activities and viral genome of PAC3 strain was detected in supernatants during cell infection earlier than in the other two strains, which shows that PAC3 virions release from the host cell earlier than LPM and PAC1. Experimental determination in purified viruses shows that PAC3 presented a higher HA and NA activities; however, PAC1 shows other interesting properties, such as a high thermostability of HN and differences about substrate profile respect to LPM and PAC3. Our data suggest that NA activity is associated with the virulence of RVP.

  15. Antitubercular and antibacterial activity of quinonoid natural products against multi-drug resistant clinical isolates.

    PubMed

    Dey, Diganta; Ray, Ratnamala; Hazra, Banasri

    2014-07-01

    Multi-drug resistant Mycobacterium tuberculosis and other bacterial pathogens represent a major threat to human health. In view of the critical need to augment the current drug regime, we have investigated therapeutic potential of five quinonoids, viz. emodin, diospyrin, plumbagin, menadione and thymoquinone, derived from natural products. The antimicrobial activity of quinonoids was evaluated against a broad panel of multi-drug and extensively drug-resistant tuberculosis (M/XDR-TB) strains, rapid growing mycobacteria and other bacterial isolates, some of which were producers of β-lactamase, Extended-spectrum β-lactamase (ESBL), AmpC β-lactamase, metallo-beta-lactamase (MBL) enzymes, as well as their drug-sensitive ATCC counterparts. All the tested quinones exhibited antimycobacterial and broad spectrum antibacterial activity, particularly against M. tuberculosis (lowest MIC 0.25 µg/mL) and Gram-positive bacteria (lowest MIC <4 µg/mL) of clinical origin. The order of antitubercular activity of the tested quinonoids was plumbagin > emodin ~ menadione ~ thymoquinone > diospyrin, whereas their antibacterial efficacy was plumbagin > menadione ~ thymoquinone > diospyrin > emodin. Furthermore, this is the first evaluation performed on these quinonoids against a broad panel of drug-resistant and drug-sensitive clinical isolates, to the best of our knowledge.

  16. Plants, endosymbionts and parasites

    PubMed Central

    Nagamune, Kisaburo; Xiong, Liming; Chini, Eduardo

    2008-01-01

    It was recently discovered that the protozoan parasite, Toxoplasma gondii produces and uses the plant hormone, abscisic acid (ABA), for communication. Following intracellular replication, ABA production influences the timing of parasite egress from the host cell. This density-dependent signal may serve to coordinate exit from the host cell in a synchronous manner by triggering calcium-dependent activation of motility. In the absence of ABA production, parasites undergo differentiation to the semidormant, tissue cyst. The pathway for ABA production in T. gondii may be derived from a relict endosymbiont, acquired by ingestion of a red algal cell. Although the parasite has lost the capacity for photosynthesis, the plant-like nature of this signaling pathway may be exploited to develop new drugs. In support of this idea, an inhibitor of ABA biosynthesis protected mice against lethal infection with T. gondii. Here, we compare the role of ABA in parasites to its activities in plants, where it is know to control development and stress responses. PMID:19513200

  17. Modeling the Long-Term Isolation Performance of Natural and Engineered Geologic CO2 Storage Sites

    SciTech Connect

    Johnson, J W; Nitao, J J; Morris, J P

    2004-07-26

    Long-term cap rock integrity represents the single most important constraint on the long-term isolation performance of natural and engineered geologic CO{sub 2} storage sites. CO{sub 2} influx that forms natural accumulations and CO{sub 2} injection for EOR/sequestration or saline-aquifer disposal both lead to concomitant geochemical alteration and geomechanical deformation of the cap rock, enhancing or degrading its seal integrity depending on the relative effectiveness of these interdependent processes. This evolution of cap-rock permeability can be assessed through reactive transport modeling, an advanced computational method based on mathematical models of the coupled physical and chemical processes catalyzed by the influx event. Using our reactive transport simulator (NUFT), supporting geochemical databases and software (SUPCRT92), and distinct-element geomechanical model (LDEC), we have shown that influx-triggered mineral dissolution/precipitation reactions within typical shale cap rocks continuously reduce microfrac apertures, while pressure and effective-stress evolution first rapidly increase then slowly constrict them. For a given shale composition, the extent of geochemical enhancement is nearly independent of key reservoir properties (permeability and lateral continuity) that distinguish saline aquifer and EOR/sequestration settings and CO{sub 2} influx parameters (rate, focality, and duration) that distinguish engineered disposal sites and natural accumulations, because these characteristics and parameters have negligible impact on mineral reaction rates. In contrast, the extent of geomechanical degradation is highly dependent on these reservoir properties and influx parameters, because they effectively dictate magnitude of the pressure perturbation. Specifically, initial geomechanical degradation has been shown inversely proportional to reservoir permeability and lateral continuity and proportional to influx rate. As a result, while the extent of

  18. Birds are islands for parasites.

    PubMed

    Koop, Jennifer A H; DeMatteo, Karen E; Parker, Patricia G; Whiteman, Noah K

    2014-08-01

    Understanding the mechanisms driving the extraordinary diversification of parasites is a major challenge in evolutionary biology. Co-speciation, one proposed mechanism that could contribute to this diversity is hypothesized to result from allopatric co-divergence of host-parasite populations. We found that island populations of the Galápagos hawk (Buteo galapagoensis) and a parasitic feather louse species (Degeeriella regalis) exhibit patterns of co-divergence across variable temporal and spatial scales. Hawks and lice showed nearly identical population genetic structure across the Galápagos Islands. Hawk population genetic structure is explained by isolation by distance among islands. Louse population structure is best explained by hawk population structure, rather than isolation by distance per se, suggesting that lice tightly track the recent population histories of their hosts. Among hawk individuals, louse populations were also highly structured, suggesting that hosts serve as islands for parasites from an evolutionary perspective. Altogether, we found that host and parasite populations may have responded in the same manner to geographical isolation across spatial scales. Allopatric co-divergence is likely one important mechanism driving the diversification of parasites.

  19. Concentrical coils counter-current chromatography for natural products isolation: Salvia miltiorrhiza Bunge as example.

    PubMed

    Zhang, Lihong; Wang, Yanyan; Guo, Xiuyun; Wu, Shihua

    2017-02-22

    Countercurrent chromatography (CCC) is an efficient separation technique without the solid support matrix, largely depending on the partition of two-immiscible liquid phases in the separation column. Since the helical coil planet centrifuge was invented in early 1970s by Yoichiro Ito, a series of coils columns, including spiral coils and conical coils columns have been developed for CCC separation. In this work, we introduced a new simple and efficient concentrical coils column for CCC separation, which was prepared by winding the whole polytetrafluoroethylene (PTFE) tube into the circular grooves from the rotation axis in the same direction. Once the PTFE tube filled in all space of one round of the circular groove, it was jumped into the nearby outer circular groove through the gap and until the whole groove was filled. The three same concentrical coils distributed on three disc-shaped holders were connected by the same PTFE tube to form concentrical coils separation column. The separation capacity was further investigated using ten tanshinones of the extracts of a Traditional Chinese Medicine Salvia miltiorrhiza Bunge as a model natural product. All results indicated that the concentrical coils column could hold satisfactory retention of the stationary phase, higher theoretical plate number and better resolution for CCC separation of more than ten tanshinones. It may be an alternative CCC column for non-targeted and targeted isolation of bioactive natural products.

  20. Mitochondrial changes induced by natural and synthetic asbestos fibers: studies on isolated mitochondria.

    PubMed

    Bergamini, C; Fato, R; Biagini, G; Pugnaloni, A; Giantomassi, F; Foresti, E; Lesci, G I; Roveri, N; Lenaz, G

    2007-01-21

    Asbestos fibers, such as chrysotile and crocidolite, are known to have cytotoxic effects on different cell types. In vivo exposure to asbestos fibers can induce both fibrotic and malignant lung diseases , however, the mechanisms linking exposure to the subsequent development of the diseases are unknown. Numerous investigations suggest the involvement of reactive oxygen species (ROS). ROS are known to damage biological macromolecules including proteins, cell membrane lipids and nucleic acids; alterations of these essential cellular components can alter cell function and can drive the cell to neoplastic transformation or to cell death. Because the mitochondrial respiratory chain is an important source of ROS and RNS (reactive nitogen species) in the cells, we have investigated the effects of aqueous extracts of asbestos (natural and synthetic) fibers on some mitochondrial activities. Our data show that crocidolite fibers release substances in solution that may interfere directly with the mitochondrial cytochrome oxidase complex. Moreover, the calcium ions released from these fibers induce opening of the permeability transition pore of the inner membrane leading to a possible cytotoxic effect due to the release of apoptotic factors normally localized in the mitochondrial intermembrane space. In addition, crocidolite extracts enhance the mitochondrial production of ROS. No significant biochemical effects are exerted by chrysotile, either natural or synthetic, on isolated mitochondria. Nevertheless, all asbestos fibers tested induce morphological alterations visualized by transmission electron microscopy and morphometric analysis.

  1. Mitochondrial changes induced by natural and synthetic asbestos fibers: studies on isolated mitochondria.

    PubMed

    Bergamini, C; Fato, R; Biagini, G; Pugnaloni, A; Giantomassi, F; Foresti, E; Lesci, G I; Roveri, N; Lenaz, G

    2004-01-01

    Asbestos fibers, such as chrysotile and crocidolite, are known to have cytotoxic effects on different cell types. in vivo exposure to asbestos fibers can induce both fibrotic and malignant lung diseases , however, the mechanisms linking exposure to the subsequent development of the diseases are unknown. Numerous investigations suggest the involvement of reactive oxygen species (ROS). ROS are known to damage biological macromolecules including proteins, cell membrane lipids and nucleic acids; alterations of these essential cellular components can alter cell function and can drive the cell to neoplastic transformation or to cell death. Because the mitochondrial respiratory chain is an important source of ROS and RNS (reactive nitogen species) in the cells, we have investigated the effects of aqueous extracts of asbestos (natural and synthetic) fibers on some mitochondrial activities. Our data show that crocidolite fibers release substances in solution that may interfere directly with the mitochondrial cytochrome oxidase complex. Moreover, the calcium ions released from these fibers induce opening of the permeability transition pore of the inner membrane leading to a possible cytotoxic effect due to the release of apoptotic factors normally localized in the mitochondrial intermembrane space. In addition, crocidolite extracts enhance the mitochondrial production of ROS. No significant biochemical effects are exerted by chrysotile, either natural or synthetic, on isolated mitochondria. Nevertheless, all asbestos fibers tested induce morphological alterations visualized by transmission electron microscopy and morphometric analysis.

  2. Immunological characterization of a bacterial protein isolated from salmonid fish naturally infected with Piscirickettsia salmonis.

    PubMed

    Marshall, Sergio H; Conejeros, Pablo; Zahr, Marcela; Olivares, Jorge; Gómez, Fernando; Cataldo, Patricio; Henríquez, Vitalia

    2007-03-01

    The Salmon Rickettsia syndrome (SRS) remains a major infectious disease in the Chilean aquaculture. A limited number of Piscirickettsia salmonis proteins have been characterized so far for their use as potential candidates for vaccines studies. In this study, we identified and expressed a highly immunogenic protein of P. salmonis extracted by selective hydrophobicity from crude-cell macerates of naturally infected salmonid fish. One and two-D PAGE gels followed by Western blot analysis with a battery of polyclonal anti-P. salmonis antibodies have allowed the isolation of the target protein. Basic local alignment search (BLAST) done after partial sequencing of the pure protein identified it as a member of the heat-shock protein (HSP) family of prokaryotes. The protein, named ChaPs, was cloned as a single open reading frame encoding 545 amino acid residues with a predicted molecular mass of 57.3 kDa. The amplicon representing the entire novel gene was expressed in vitro in different heterologous systems: the PurePro Caulobacter crescentus expression system from where most of the characterization was attained, and also in the Escherichia coli BL-21 CodonPlus model for commercially potential purposes. The immunologic potential of ChaPs was determined with serum from naturally infected fish.

  3. Inhibition of dextran sulfate sodium (DSS)-induced intestinal inflammation via enhanced IL-10 and TGF-beta production by galectin-9 homologues isolated from intestinal parasites.

    PubMed

    Kim, Joo-Young; Cho, Min Kyoung; Choi, Seon Hee; Lee, Keun Hee; Ahn, Soon Cheol; Kim, Dong-Hee; Yu, Hak Sun

    2010-11-01

    We isolated a galectin-9 (Gal-9) homologue gene (Tl-gal) from an adult worm of the canine gastrointestinal nematode parasite, Toxascaris leonina, via random cDNA library sequencing. The deduced amino acid sequence of the Tl-gal genes evidenced an identity of 89% with the galectin of Dirofilaria immitis, 87% identity with the galectin of Brugia malayi, and 35% identity with the human GAL-9 gene. To evaluate immune modulate function of Tl-GAL in host inflammatory response, we constructed recombinant Tl-GAL (rTl-GAL) using an Escherichia coli expression vector system and treated to intestinal inflammation mice. Although the carbohydrate-binding ability of rTl-GAL was less than that of rat galectin, we confirmed that recombinant rTl-GAL has carbohydrate-binding activity. The clinical symptoms of dextran sulfate sodium (DSS)-treated mice after rTl-GAL pre-treatment were found to be minimized, or less profound, as compared to those of the rTl-GAL untreated group. Additionally, the DSS-treated mice exhibited a significant shortening of the colon, but the large intestines of the rTl-GAL pre-treated mice were longer than those of the control group (P<0.05). Additionally, the rTl-GAL treated group exhibited significantly increased the levels of TGF-beta and IL-10 (P<0.05). The production of these regulatory cytokines may ameliorate intestinal inflammation. These findings demonstrate that rTl-GAL could inhibit inflammation reactions via the inhibition of Th1 and Th2 cytokine production by increasing the production of TGF-beta and IL-10 cytokines. The rTl-GAL may induce TGF-beta expression, primarily via the activation of the p38 pathway. In conclusion, rTl-GAL may function like a host galectin, thus functioning as a regulatory molecule in the host immune system; rTl-GAL may prove useful in the design of novel therapeutic intervention strategies for the treatment of allergic and immune diseases.

  4. A Passion for Parasites

    PubMed Central

    Englund, Paul T.

    2014-01-01

    I knew nothing and had thought nothing about parasites until 1971. In fact, if you had asked me before then, I might have commented that parasites were rather disgusting. I had been at the Johns Hopkins School of Medicine for three years, and I was on the lookout for a new project. In 1971, I came across a paper in the Journal of Molecular Biology by Larry Simpson, a classmate of mine in graduate school. Larry's paper described a remarkable DNA structure known as kinetoplast DNA (kDNA), isolated from a parasite. kDNA, the mitochondrial genome of trypanosomatids, is a DNA network composed of several thousand interlocked DNA rings. Almost nothing was known about it. I was looking for a project on DNA replication, and I wanted it to be both challenging and important. I had no doubt that working with kDNA would be a challenge, as I would be exploring uncharted territory. I was also sure that the project would be important when I learned that parasites with kDNA threaten huge populations in underdeveloped tropical countries. Looking again at Larry's paper, I found the electron micrographs of the kDNA networks to be rather beautiful. I decided to take a chance on kDNA. Little did I know then that I would devote the next forty years of my life to studying kDNA replication. PMID:25336639

  5. Foodborne Parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne infections are a significant cause of morbidity and mortality worldwide, and foodborne parasitic diseases, though not as widespread as bacterial and viral infections, are common on all continents and in most ecosystems, including arctic, temperate, and tropical regions. Certain foodborne ...

  6. Parasitic Apologies

    ERIC Educational Resources Information Center

    Galatolo, Renata; Ursi, Biagio; Bongelli, Ramona

    2016-01-01

    The action of apologizing can be accomplished as the main business of the interaction or incidentally while participants are doing something else. We refer to these apologies as "parasitic apologies," because they are produced "en passant" (Schegloff, 2007), and focus our analysis on this type of apology occurring at the…

  7. Evaluation of current techniques for isolation of chars as natural adsorbents

    USGS Publications Warehouse

    Chun, Y.; Sheng, G.; Chiou, C.T.

    2004-01-01

    Chars in soils or sediments may potentially influence the soil/sediment sorption behavior. Current techniques for the isolation of black carbon including chars rely often on acid demineralization, base extraction, and chemical oxidation to remove salts and minerals, humic acid, and refractory kerogen, respectively. Little is known about the potential effects of these chemical processes on the char surface and adsorptive properties. This study examined the effects of acid demineralization, base extraction, and acidic Cr2O72- oxidation on the surface areas, surface acidity, and benzene adsorption characteristics of laboratory-produced pinewood and wheat-residue chars, pure or mixed with soils, and a commercial activated carbon. Demineralization resulted in a small reduction in the char surface area, whereas base extraction showed no obvious effect. Neither demineralization nor base extraction caused an appreciable variation in benzene adsorption and presumably the char surface properties. By contrast, the Cr2O 72- oxidation caused a >31% reduction in char surface area. The Boehm titration, supplemented by FTIR spectra, indicated that the surface acidity of oxidized chars increased by a factor between 2.3 and 12 compared to nonoxidized chars. Benzene adsorption with the oxidized chars was lower than that with the non-oxidized chars by a factor of >8.9; both the decrease in char surface area and the increase in char surface acidity contributed to the reduction in char adsorptive power. Although the Cr 2O72- oxidation effectively removes resistant kerogen, it is not well suited for the isolation of chars as contaminant adsorbents because of its destructive nature. Alternative nondestructive techniques that preserve the char surface properties and effectively remove kerogen must be sought.

  8. Probiotic properties of E nterococcus strains isolated from traditional naturally fermented cream in China

    PubMed Central

    Guo, Lidong; Li, Tingting; Tang, Yaru; Yang, Lijie

    2015-01-01

    Summary The purpose of this study was to evaluate the probiotic properties of Enterococcus strains isolated from traditional naturally fermented cream in China. Four E nterococcus isolates showed high cholesterol removal ability in media were identified as E nterococcus durans (KLDS 6.0930 and 6.0933) and E nterococcus faecalis (KLDS 6.0934 and 6.0935) by 16S rRNA and pheS gene sequences, respectively, and selected for further evaluation. In order to assess the probiotic potential and safety of these strains, the property of four E nterococcus strains were examined, including acid and bile tolerance, adherence to Caco‐2 cells and antibiotics susceptibility. All four strains showed potential cholesterol assimilation, de‐conjugation of bile salts and/or cholesterol degradation to remove cholesterol in vitro. In addition, the potential effect of E. durans  KLDS 6.0930 on serum cholesterol levels was evaluated in Sprague‐Dawley rats. After 4 weeks administration, compared with rats fed a high‐cholesterol diet without lactic acid bacteria supplementation, there was a significant (P < 0.05) decrease in the total cholesterol and low‐density lipoprotein cholesterol levels in the serum of rats treated with KLDS 6.0930. Furthermore, total bile acid level in the feces was significantly (P < 0.05) increased after KLDS 6.0930 administration. These observations suggested that the strain E. durans  KLDS 6.0930 may be used in the future as a good candidate for lowering human serum cholesterol levels. PMID:26200795

  9. The use of isolated natural products as scaffolds for the generation of chemically diverse screening libraries for drug discovery.

    PubMed

    Barnes, Emma C; Kumar, Rohitesh; Davis, Rohan A

    2016-03-01

    A diverse range of strategies leading to natural product derived or inspired screening libraries aims to increase the number of new chemical entities emerging per year. However, the use of isolated natural products as scaffolds for the semi-synthesis of larger biological screening libraries remains rare. This particular method avoids the time-consuming and resource intensive de novo synthetic strategy for scaffold production, and has become more feasible through improvements to synthetic and isolation methodologies. This Highlight examines the increasing popularity of small- to large-sized screening libraries generated directly from isolated natural products. Several of the examples detailed herein show how this strategy can lead to improvements in not only potency but also other important (and often forgotten) drug discovery parameters such as toxicity, selectivity, lipophilicity and bioavailability. However, there are still improvements to be made to this method, particularly in the choice of the natural product scaffold and the derivatising reagents used. Avoidance of known nuisance compounds or structural alert motifs (e.g. PAINS) that interfere with bioactivity screens, and impact downstream drug development will play a significant role in the future success of this methodology. Incorporation of rational design strategies that take into account the physicochemical parameters (e.g. log P, MW, HBA, HBD) of the final semi-synthetic library analogues will also facilitate the discovery and development of leads and drugs. A multi-pronged approach to drug discovery that incorporates the use of isolated natural product scaffolds for library generation will surely be beneficial.

  10. Leishmanization revisited: immunization with a naturally attenuated cutaneous Leishmania donovani isolate from Sri Lanka protects against visceral leishmaniasis.

    PubMed

    McCall, Laura-Isobel; Zhang, Wen-Wei; Ranasinghe, Shanlindra; Matlashewski, Greg

    2013-02-27

    Leishmaniasis is a neglected tropical disease caused by Leishmania protozoa and associated with three main clinical presentations: cutaneous, mucocutaneous and visceral leishmaniasis. Visceral leishmaniasis is the second most lethal parasitic disease after malaria and there is so far no human vaccine. Leishmania donovani is a causative agent of visceral leishmaniasis in South East Asia and Eastern Africa. However, in Sri Lanka, L. donovani causes mainly cutaneous leishmaniasis, while visceral leishmaniasis is rare. We investigate here the possibility that the cutaneous form of L. donovani can provide immunological protection against the visceral form of the disease, as a potential explanation for why visceral leishmaniasis is rare in Sri Lanka. Subcutaneous immunization with a cutaneous clinical isolate from Sri Lanka was significantly protective against visceral leishmaniasis in BALB/c mice. Protection was associated with a mixed Th1/Th2 response. These results provide a possible rationale for the scarcity of visceral leishmaniasis in Sri Lanka and could guide leishmaniasis vaccine development efforts.

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

    PubMed

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

    2013-10-01

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

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

    PubMed Central

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

    2013-01-01

    Blastocystis sp. is among the few enteric parasites with a prevalence that often exceeds 5% in the general population of industrialized countries and can reach 30–60% in developing countries. This parasite is frequently found in people who are immunocompromised (patients with human immunodeficiency virus/acquired immunodeficiency syndrome or cancer) and a higher risk of Blastocystis sp. infection has been found in people with close animal contact. Such prevalence in the human population and the zoonotic potential naturally raise questions about the impact of these parasites on public health and has increased interest in this area. Recent in vitro and in vivo studies have shed new light on the pathogenic power of this parasite, suggesting that Blastocystis sp. infection is associated with a variety of gastrointestinal disorders, may play a significant role in irritable bowel syndrome, and may be linked with cutaneous lesions (urticaria). Despite recent significant advances in the knowledge of the extensive genetic diversity of this species, the identification of extracellular proteases as virulence factors and the publication of one isolate genome, many aspects of the biology of Blastocystis sp. remain poorly investigated. In this review, we investigate several biological aspects of Blastocystis sp. (diversity and epidemiology, diagnosis tools and pathophysiology). These data pave the way for the following challenges concerning Blastocystis sp. research: deciphering key biological mechanisms and pathways of this parasite and clarification of its clinical impact in humans. PMID:25165551

  13. Antibiotic resistance plasmids spread among natural isolates of Escherichia coli in spite of CRISPR elements.

    PubMed

    Touchon, Marie; Charpentier, Sophie; Pognard, Dominique; Picard, Bertrand; Arlet, Guillaume; Rocha, Eduardo P C; Denamur, Erick; Branger, Catherine

    2012-12-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPRs) are implicated in defence against foreign DNA in various archaeal and bacterial species. They have also been associated with a slower spread of antibiotic resistance. However, experimental and evolutionary studies raise doubts about the role of CRISPRs as a sort of immune system in Escherichia coli. We studied a collection of 263 natural E. coli isolates from human and animal hosts, representative of the phylogenetic and lifestyle diversity of the species and exhibiting various levels of plasmid-encoded antibiotic resistance. We characterized the strains in terms of CRISPRs, performed replicon typing of the plasmids and tested for class 1 integrons to explore the possible association between CRISPRs and the absence of plasmids and mobile antibiotic resistance determinants. We found no meaningful association between the presence/absence of the cas genes, reflecting the activity of the CRISPRs, and the presence of plasmids, integrons or antibiotic resistance. No CRISPR in the collection contained a spacer that matched an antibiotic resistance gene or element involved in antibiotic resistance gene mobilization, and 79.8 % (210/263) of the strains lacked spacers matching sequences in the 2282 plasmid genomes available. Hence, E. coli CRISPRs do not seem to be efficient barriers to the spread of plasmids and antibiotic resistance, consistent with what has been reported for phages, and contrary to reports concerning other species.

  14. Antibiotic resistance plasmids spread among natural isolates of Escherichia coli in spite of CRISPR elements.

    PubMed

    Touchon, Marie; Charpentier, Sophie; Pognard, Dominique; Picard, Bertrand; Arlet, Guillaume; Rocha, Eduardo P C; Denamur, Erick; Branger, Catherine

    2012-12-01

    Clustered, regularly interspaced, short palindromic repeats (CRISPRs) are implicated in defence against foreign DNA in various archaeal and bacterial species. They have also been associated with a slower spread of antibiotic resistance. However, experimental and evolutionary studies raise doubts about the role of CRISPRs as a sort of immune system in Escherichia coli. We studied a collection of 263 natural E. coli isolates from human and animal hosts, representative of the phylogenetic and lifestyle diversity of the species and exhibiting various levels of plasmid-encoded antibiotic resistance. We characterized the strains in terms of CRISPRs, performed replicon typing of the plasmids and tested for class 1 integrons to explore the possible association between CRISPRs and the absence of plasmids and mobile antibiotic resistance determinants. We found no meaningful association between the presence/absence of the cas genes, reflecting the activity of the CRISPRs, and the presence of plasmids, integrons or antibiotic resistance. No CRISPR in the collection contained a spacer that matched an antibiotic resistance gene or element involved in antibiotic resistance gene mobilization, and 79.8% (210/263) of the strains lacked spacers matching sequences in the 2282 plasmid genomes available. Hence, E. coli CRISPRs do not seem to be efficient barriers to the spread of plasmids and antibiotic resistance, consistent with what has been reported for phages, and contrary to reports concerning other species.

  15. On the Mapping of Epistatic Genetic Interactions in Natural Isolates: Combining Classical Genetics and Genomics.

    PubMed

    Hou, Jing; Schacherer, Joseph

    2016-01-01

    Genetic variation within species is the substrate of evolution. Epistasis, which designates the non-additive interaction between loci affecting a specific phenotype, could be one of the possible outcomes of genetic diversity. Dissecting the basis of such interactions is of current interest in different fields of biology, from exploring the gene regulatory network, to complex disease genetics, to the onset of reproductive isolation and speciation. We present here a general workflow to identify epistatic interactions between independently evolving loci in natural populations of the yeast Saccharomyces cerevisiae. The idea is to exploit the genetic diversity present in the species by evaluating a large number of crosses and analyzing the phenotypic distribution in the offspring. For a cross of interest, both parental strains would have a similar phenotypic value, whereas the resulting offspring would have a bimodal distribution of the phenotype, possibly indicating the presence of epistasis. Classical segregation analysis of the tetrads uncovers the penetrance and complexity of the interaction. In addition, this segregation could serve as the guidelines for choosing appropriate mapping strategies to narrow down the genomic regions involved. Depending on the segregation patterns observed, we propose different mapping strategies based on bulk segregant analysis or consecutive backcrosses followed by high-throughput genome sequencing. Our method is generally applicable to all systems with a haplodiplobiontic life cycle and allows high resolution mapping of interacting loci that govern various DNA polymorphisms from single nucleotide mutations to large-scale structural variations.

  16. Species interactions in a parasite community drive infection risk in a wildlife population.

    PubMed

    Telfer, Sandra; Lambin, Xavier; Birtles, Richard; Beldomenico, Pablo; Burthe, Sarah; Paterson, Steve; Begon, Mike

    2010-10-08

    Most hosts, including humans, are simultaneously or sequentially infected with several parasites. A key question is whether patterns of coinfection arise because infection by one parasite species affects susceptibility to others or because of inherent differences between hosts. We used time-series data from individual hosts in natural populations to analyze patterns of infection risk for a microparasite community, detecting large positive and negative effects of other infections. Patterns remain once variations in host susceptibility and exposure are accounted for. Indeed, effects are typically of greater magnitude, and explain more variation in infection risk, than the effects associated with host and environmental factors more commonly considered in disease studies. We highlight the danger of mistaken inference when considering parasite species in isolation rather than parasite communities.

  17. Whole-genome sequence analysis of the naturally competent Acinetobacter baumannii clinical isolate A118.

    PubMed

    Traglia, German M; Chua, Katherina; Centrón, Daniela; Tolmasky, Marcelo E; Ramírez, María Soledad

    2014-08-26

    Recent studies have demonstrated a high genomic plasticity in Acinetobacter baumannii, which may explain its high capacity to acquire multiple antibiotic resistance determinants and to survive in the hospital environment. Acinetobacter baumannii strain A118 (Ab A118) was isolated in the year 1995 from a blood culture of an intensive care unit patient. As this particular strain showed some peculiar characteristic such as being naturally competent and susceptible to numerous antibiotics, we performed whole-genome comparison (WGC) studies to gain insights into the nature and extent of the genomic differences. The Ab A118 genome is approximately 3,824 kb long with a 38.4% GC content and contains 3,520 coding sequences. WGC studies showed that the Ab A118 genome has 98% average nucleotide identity with that of A. baumannii ATCC 17978, and 96% average nucleotide identity with that of strains AYE and ACICU. At least 12 inversions, 275 insertions, and 626 deletions were identified when the Ab A118 genome was compared with those of strains ATCC 17978, AYE, and ACICU using MAUVE WGC. Multiple gene order arrangements were observed among the analyzed strains. MAUVE WGC analysis identified 19 conserved segments, known as locally colinear blocks. The number of single nucleotide polymorphisms found when comparing the Ab A118 genome with that of strains ATCC 17978, AYE, and ACICU was 43,784 (1.1496%), 44,130 (1.158%), and 43,914 (1.153%), respectively. Genes comEA, pilQ, pilD, pilF, comL, pilA, comEC, pilI, pilH, pilO, pilN, pilY1(comC), pilE, pilR, and comM, potentially involved in natural competence were found in the Ab A118 genome. In particular, unlike in most strains where comM is interrupted by an insertion of a resistance island (AbaR), in strain Ab A118 it is uninterrupted.

  18. Whole-Genome Sequence Analysis of the Naturally Competent Acinetobacter baumannii Clinical Isolate A118

    PubMed Central

    Traglia, German M.; Chua, Katherina; Centrón, Daniela; Tolmasky, Marcelo E.; Ramírez, María Soledad

    2014-01-01

    Recent studies have demonstrated a high genomic plasticity in Acinetobacter baumannii, which may explain its high capacity to acquire multiple antibiotic resistance determinants and to survive in the hospital environment. Acinetobacter baumannii strain A118 (Ab A118) was isolated in the year 1995 from a blood culture of an intensive care unit patient. As this particular strain showed some peculiar characteristic such as being naturally competent and susceptible to numerous antibiotics, we performed whole-genome comparison (WGC) studies to gain insights into the nature and extent of the genomic differences. The Ab A118 genome is approximately 3,824 kb long with a 38.4% GC content and contains 3,520 coding sequences. WGC studies showed that the Ab A118 genome has 98% average nucleotide identity with that of A. baumannii ATCC 17978, and 96% average nucleotide identity with that of strains AYE and ACICU. At least 12 inversions, 275 insertions, and 626 deletions were identified when the Ab A118 genome was compared with those of strains ATCC 17978, AYE, and ACICU using MAUVE WGC. Multiple gene order arrangements were observed among the analyzed strains. MAUVE WGC analysis identified 19 conserved segments, known as locally colinear blocks. The number of single nucleotide polymorphisms found when comparing the Ab A118 genome with that of strains ATCC 17978, AYE, and ACICU was 43,784 (1.1496%), 44,130 (1.158%), and 43,914 (1.153%), respectively. Genes comEA, pilQ, pilD, pilF, comL, pilA, comEC, pilI, pilH, pilO, pilN, pilY1(comC), pilE, pilR, and comM, potentially involved in natural competence were found in the Ab A118 genome. In particular, unlike in most strains where comM is interrupted by an insertion of a resistance island (AbaR), in strain Ab A118 it is uninterrupted. PMID:25164683

  19. Parasite load induces progressive spleen architecture breakage and impairs cytokine mRNA expression in Leishmania infantum-naturally infected dogs.

    PubMed

    Cavalcanti, Amanda S; Ribeiro-Alves, Marcelo; Pereira, Luiza de O R; Mestre, Gustavo Leandro; Ferreira, Anna Beatriz Robottom; Morgado, Fernanda N; Boité, Mariana C; Cupolillo, Elisa; Moraes, Milton O; Porrozzi, Renato

    2015-01-01

    Canine Visceral Leishmaniasis (CVL) shares many aspects with the human disease and dogs are considered the main urban reservoir of L. infantum in zoonotic VL. Infected dogs develop progressive disease with a large clinical spectrum. A complex balance between the parasite and the genetic/immunological background of the host are decisive for infection evolution and clinical outcome. This study comprised 92 Leishmania infected mongrel dogs of various ages from Mato Grosso, Brazil. Spleen samples were collected for determining parasite load, humoral response, cytokine mRNA expression and histopathology alterations. By real-time PCR for the ssrRNA Leishmania gene, two groups were defined; a low (lowP, n = 46) and a high parasite load groups (highP, n = 42). When comparing these groups, results show variable individual humoral immune response with higher specific IgG production in infected animals but with a notable difference in CVL rapid test optical densities (DPP) between highP and lowP groups. Splenic architecture disruption was characterized by disorganization of white pulp, more evident in animals with high parasitism. All cytokine transcripts in spleen were less expressed in highP than lowP groups with a large heterogeneous variation in response. Individual correlation analysis between cytokine expression and parasite load revealed a negative correlation for both pro-inflammatory cytokines: IFNγ, IL-12, IL-6; and anti-inflammatory cytokines: IL-10 and TGFβ. TNF showed the best negative correlation (r2 = 0.231; p<0.001). Herein we describe impairment on mRNA cytokine expression in leishmania infected dogs with high parasite load associated with a structural modification in the splenic lymphoid micro-architecture. We also discuss the possible mechanism responsible for the uncontrolled parasite growth and clinical outcome.

  20. The complete annotated genome sequences of three Campylobacter jejuni strains isolated from naturally colonized, farm raised chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter jejuni is a leading cause of bacterially derived foodborne illness worldwide. Human illness is commonly associated with handling and consumption of contaminated poultry products. Three C. jejuni strains were isolated from cecal contents of three different naturally colonized, farm rais...

  1. Nature's Chiral Catalyst and Anti-Malarial Agent: Isolation and Structure Elucidation of Cinchonine and Quinine from "Cinchona calisaya"

    ERIC Educational Resources Information Center

    Carroll, Anne-Marie; Kavanagh, David J.; McGovern, Fiona P.; Reilly, Joe W.; Walsh, John J.

    2012-01-01

    Nature is a well-recognized source of compounds of interest, but access is often an issue. One pertinent example is the cinchona alkaloids from the bark of "Cinchona calisaya." In this experiment, students at the third-year undergraduate level undertake the selective isolation and characterization of two of the four main alkaloids present in the…

  2. Complete genome sequence of Streptomyces sp. strain CFMR 7, a natural rubber degrading actinomycete isolated from Penang, Malaysia.

    PubMed

    Nanthini, Jayaram; Chia, Kim-Hou; Thottathil, Gincy P; Taylor, Todd D; Kondo, Shinji; Najimudin, Nazalan; Baybayan, Primo; Singh, Siddharth; Sudesh, Kumar

    2015-11-20

    Streptomyces sp. strain CFMR 7, which naturally degrades rubber, was isolated from a rubber plantation. Whole genome sequencing and assembly resulted in 2 contigs with total genome size of 8.248 Mb. Two latex clearing protein (lcp) genes which are responsible for rubber degrading activities were identified.

  3. Draft Genome Sequence of Strain Q-1, an Iodide-Oxidizing Alphaproteobacterium Isolated from Natural Gas Brine Water

    PubMed Central

    Ehara, Ayaka; Suzuki, Haruo; Kanesaki, Yu; Yoshikawa, Hirofumi

    2014-01-01

    Here we report the draft genome sequence of strain Q-1, an iodide (I−)-oxidizing heterotrophic bacterium in the class Alphaproteobacteria isolated from natural gas brine water. The genome sequence contained a multicopper oxidase gene probably responsible for iodide oxidation. A photosynthetic gene cluster was found but genes for carbon-fixation were absent. PMID:24994802

  4. Fossils of parasites: what can the fossil record tell us about the evolution of parasitism?

    PubMed

    Leung, Tommy L F

    2017-02-01

    Parasites are common in many ecosystems, yet because of their nature, they do not fossilise readily and are very rare in the geological record. This makes it challenging to study the evolutionary transition that led to the evolution of parasitism in different taxa. Most studies on the evolution of parasites are based on phylogenies of extant species that were constructed based on morphological and molecular data, but they give us an incomplete picture and offer little information on many important details of parasite-host interactions. The lack of fossil parasites also means we know very little about the roles that parasites played in ecosystems of the past even though it is known that parasites have significant influences on many ecosystems. The goal of this review is to bring attention to known fossils of parasites and parasitism, and provide a conceptual framework for how research on fossil parasites can develop in the future. Despite their rarity, there are some fossil parasites which have been described from different geological eras. These fossils include the free-living stage of parasites, parasites which became fossilised with their hosts, parasite eggs and propagules in coprolites, and traces of pathology inflicted by parasites on the host's body. Judging from the fossil record, while there were some parasite-host relationships which no longer exist in the present day, many parasite taxa which are known from the fossil record seem to have remained relatively unchanged in their general morphology and their patterns of host association over tens or even hundreds of millions of years. It also appears that major evolutionary and ecological transitions throughout the history of life on Earth coincided with the appearance of certain parasite taxa, as the appearance of new host groups also provided new niches for potential parasites. As such, fossil parasites can provide additional data regarding the ecology of their extinct hosts, since many parasites have

  5. The formation of halogen-specific TOX from chlorination and chloramination of natural organic matter isolates.

    PubMed

    Kristiana, Ina; Gallard, Hervé; Joll, Cynthia; Croué, Jean-Philippe

    2009-09-01

    The formation of disinfection by-products (DBPs) is a public health concern. An important way to evaluate the presence of DBPs is in terms of the total organic halogen (TOX), which can be further specified into total organic chlorine (TOCl), bromine (TOBr), and iodine (TOI). The formation and distribution of halogen-specific TOX during chlorination and chloramination of natural organic matter (NOM) isolates in the presence of bromide and iodide ions were studied. As expected, chloramination produced significantly less TOX than chlorination. TOCl was the dominant species formed in both chlorination and chloramination. TOI was always produced in chloramination, but not in chlorination when high chlorine dose was used, due to the limited presence of HOI in chlorination as a result of the oxidation of iodide to iodate in the presence of excess chlorine. The formation of TOI during chloramination increased as the initial iodide ion concentration increased, with a maximum of approximately 60% of the initial iodide ion becoming incorporated into NOM. Iodine incorporation in NOM was consistently higher than bromine incorporation, demonstrating that the competitive reactions between bromine and iodine species in chloramination favoured the formation of HOI and thus TOI, rather than TOBr. Correlations between the aromatic character of the NOM isolates (SUVA(254) and % aromatic C) and the concentrations of overall TOX and halogen-specific TOX in chloramination were observed. This indicates that the aromatic moieties in NOM, as indicated by SUVA(254) and % aromatic C, play an important role in the formation of overall TOX and halogen-specific TOX in chloramination. THMs comprised only a fraction of TOX, up to 7% in chloramination and up to 47% in chlorination. Although chloramine produces less TOX than chlorine, it formed proportionally more non-THM DBPs than chlorine. These non-THM DBPs are mostly unknown, corresponding to unknown health risks. Considering the higher

  6. When parasites disagree: Evidence for parasite-induced sabotage of host manipulation

    PubMed Central

    Hafer, Nina; Milinski, Manfred

    2015-01-01

    Host manipulation is a common parasite strategy to alter host behavior in a manner to enhance parasite fitness usually by increasing the parasite's transmission to the next host. In nature, hosts often harbor multiple parasites with agreeing or conflicting interests over host manipulation. Natural selection might drive such parasites to cooperation, compromise, or sabotage. Sabotage would occur if one parasite suppresses the manipulation of another. Experimental studies on the effect of multi-parasite interactions on host manipulation are scarce, clear experimental evidence for sabotage is elusive. We tested the effect of multiple infections on host manipulation using laboratory-bred copepods experimentally infected with the trophically transmitted tapeworm Schistocephalus solidus. This parasite is known to manipulate its host depending on its own developmental stage. Coinfecting parasites with the same aim enhance each other's manipulation but only after reaching infectivity. If the coinfecting parasites disagree over host manipulation, the infective parasite wins this conflict: the noninfective one has no effect. The winning (i.e., infective) parasite suppresses the manipulation of its noninfective competitor. This presents conclusive experimental evidence for both cooperation in and sabotage of host manipulation and hence a proof of principal that one parasite can alter and even neutralize manipulation by another. PMID:25643621

  7. When parasites disagree: evidence for parasite-induced sabotage of host manipulation.

    PubMed

    Hafer, Nina; Milinski, Manfred

    2015-03-01

    Host manipulation is a common parasite strategy to alter host behavior in a manner to enhance parasite fitness usually by increasing the parasite's transmission to the next host. In nature, hosts often harbor multiple parasites with agreeing or conflicting interests over host manipulation. Natural selection might drive such parasites to cooperation, compromise, or sabotage. Sabotage would occur if one parasite suppresses the manipulation of another. Experimental studies on the effect of multi-parasite interactions on host manipulation are scarce, clear experimental evidence for sabotage is elusive. We tested the effect of multiple infections on host manipulation using laboratory-bred copepods experimentally infected with the trophically transmitted tapeworm Schistocephalus solidus. This parasite is known to manipulate its host depending on its own developmental stage. Coinfecting parasites with the same aim enhance each other's manipulation but only after reaching infectivity. If the coinfecting parasites disagree over host manipulation, the infective parasite wins this conflict: the noninfective one has no effect. The winning (i.e., infective) parasite suppresses the manipulation of its noninfective competitor. This presents conclusive experimental evidence for both cooperation in and sabotage of host manipulation and hence a proof of principal that one parasite can alter and even neutralize manipulation by another.

  8. Isolation, chemical characterization, and immunomodulatory activity of naturally acetylated hemicelluloses from bamboo shavings* #

    PubMed Central

    Huang, Ju-qing; Qi, Rui-ting; Pang, Mei-rong; Liu, Cong; Li, Guang-yu; Zhang, Ying

    2017-01-01

    Bamboo shavings, the outer or intermediate layer of bamboo stems, are the bulk of by-products produced in bamboo processing. In this study we investigated the isolation, chemical characterization, and immunostimulatory activity in vitro of the hemicelluloses from bamboo shavings. Shavings were first pretreated by steam explosion. The optimal pretreatment was found to be steam explosion at 2.2 MPa for 1 min. Following this pretreatment, the yield of hemicelluloses reached (2.05±0.22)% (based on the dry dewaxed raw materials), which was 5.7-fold higher than that of untreated samples. Bamboo-shavings hemicellulose (BSH) was then prepared by hot water extraction and ethanol precipitation from the steam-exploded shavings. Purification of BSH by anion-exchange chromatography of diethylaminoethanol (DEAE)-sepharose Fast Flow resulted in a neutral fraction (BSH-1, purity of 95.3%, yield of 1.06%) and an acidic fraction (BSH-2, purity of 92.5%, yield of 0.79%). The weight-average molecular weights (M w) of BSH-1 and BSH-2 were 12 800 and 11 300 g/mol, respectively. Chemical and structural analyses by Fourier transform infrared spectroscopy (FT-IR), 1D (1H and 13C) and 2D (heteronuclear single quantum correlation (HSQC)) nuclear magnetic resonance (NMR) spectra revealed that BSH-1 was O-acetylated-arabinoxylan and BSH-2 was O-acetylated-(4-O-methylglucurono)-arabinoxylan. BSH-1 had a higher content of acetyl groups than BSH-2. For the immunomodulatory activity in vitro, BSH and BSH-2 significantly stimulated mouse splenocyte proliferation while BSH-1 had no effect; BSH, BSH-1, and BSH-2 markedly enhanced the phagocytosis activity and nitric oxide production of the murine macrophage RAW264.7 in a dose-dependent manner. Our results suggest that the water-extractable hemicelluloses from steam-exploded bamboo shavings are naturally acetylated and have immunostimulatory activity. PMID:28124842

  9. Natural populations of lactic acid bacteria isolated from vegetable residues and silage fermentation.

    PubMed

    Yang, J; Cao, Y; Cai, Y; Terada, F

    2010-07-01

    Natural populations of lactic acid bacteria (LAB) and silage fermentation of vegetable residues were studied. Fifty-two strains of LAB isolated from cabbage, Chinese cabbage, and lettuce residues were identified and characterized. The LAB strains were gram-positive and catalase-negative bacteria, which were divided into 6 groups (A to F) according to morphological and biochemical characteristics. The strains in group A were rods that did not produce gas from glucose and formed the d and l isomers of lactate. Groups B and C were homofermentative cocci that formed l-lactic acid. Groups D, E, and F were heterofermentative cocci that formed d-lactic acid. Based on 16S rDNA gene sequence analysis, group A to F strains were identified as Lactobacillus plantarum, Lactococcus piscium, Lactococcus lactis, Leuconostoc citreum, Weissella soli and Leuconostoc gelidum, respectively. The prevalent LAB, predominantly homofermentative lactobacilli, consisted of Lactobacillus plantarum (34.6%), Weissella soli (19.2%), Leuconostoc gelidum (15.4%), Leuconostoc citreum (13.5%), Lactococcus lactis (9.6%), and Lactococcus piscium (7.7%). Lactobacillus plantarum was the dominant member of the LAB population in 3 types of vegetable residues. These vegetable residues contained a high level of crude protein (20.2 to 28.4% of dry matter). These silages prepared by using a small-scale fermentation system were well preserved, with low pH and a relatively high content of lactate. This study suggests that the vegetable residues contain abundant LAB species and nutrients, and that they could be well preserved by making silage, which is a potentially good vegetable protein source for livestock diets.

  10. Isolation, chemical characterization, and immunomodulatory activity of naturally acetylated hemicelluloses from bamboo shavings.

    PubMed

    Huang, Ju-Qing; Qi, Rui-Ting; Pang, Mei-Rong; Liu, Cong; Li, Guang-Yu; Zhang, Ying

    Bamboo shavings, the outer or intermediate layer of bamboo stems, are the bulk of by-products produced in bamboo processing. In this study we investigated the isolation, chemical characterization, and immunostimulatory activity in vitro of the hemicelluloses from bamboo shavings. Shavings were first pretreated by steam explosion. The optimal pretreatment was found to be steam explosion at 2.2 MPa for 1 min. Following this pretreatment, the yield of hemicelluloses reached (2.05±0.22)% (based on the dry dewaxed raw materials), which was 5.7-fold higher than that of untreated samples. Bamboo-shavings hemicellulose (BSH) was then prepared by hot water extraction and ethanol precipitation from the steam-exploded shavings. Purification of BSH by anion-exchange chromatography of diethylaminoethanol (DEAE)-sepharose Fast Flow resulted in a neutral fraction (BSH-1, purity of 95.3%, yield of 1.06%) and an acidic fraction (BSH-2, purity of 92.5%, yield of 0.79%). The weight-average molecular weights (Mw) of BSH-1 and BSH-2 were 12 800 and 11 300 g/mol, respectively. Chemical and structural analyses by Fourier transform infrared spectroscopy (FT-IR), 1D ((1)H and (13)C) and 2D (heteronuclear single quantum correlation (HSQC)) nuclear magnetic resonance (NMR) spectra revealed that BSH-1 was O-acetylated-arabinoxylan and BSH-2 was O-acetylated-(4-O-methylglucurono)-arabinoxylan. BSH-1 had a higher content of acetyl groups than BSH-2. For the immunomodulatory activity in vitro, BSH and BSH-2 significantly stimulated mouse splenocyte proliferation while BSH-1 had no effect; BSH, BSH-1, and BSH-2 markedly enhanced the phagocytosis activity and nitric oxide production of the murine macrophage RAW264.7 in a dose-dependent manner. Our results suggest that the water-extractable hemicelluloses from steam-exploded bamboo shavings are naturally acetylated and have immunostimulatory activity.

  11. Molecular signature of differential virulence in natural isolates of Erwinia amylovora.

    PubMed

    Wang, Dongping; Korban, Schuyler S; Zhao, Youfu

    2010-02-01

    ABSTRACT Erwinia amylovora, the causal agent of fire blight, is considered to be a genetically homogeneous species based on physiological, biochemical, phylogenetic, and genetic analysis. However, E. amylovora strains exhibiting differential virulence are isolated from nature. The exopolysaccharide amylovoran and type III secretion system (T3SS) are two major yet separate virulence factors in E. amylovora. The objective of this study was to investigate whether there is a correlation between E. amylovora virulence and levels of virulence gene expression. Four wild-type strains (Ea1189, Ea273, Ea110, and CFBP1430), widely used in studies of E. amylovora pathogenesis, have been analyzed and compared. E. amylovora strains Ea273 and Ea110 elicited higher severity of disease symptoms than those of Ea1189 and CFBP1430 on apple cv. Golden Delicious and G16 apple root stock plants but not on susceptible Gala plants. In addition, Ea273 and Ea110 elicited severe hypersensitive responses within shorter periods of time at lower inoculum concentrations than those of Ea1189 and CFBP1430 on tobacco plants. Further molecular analyses have revealed that amylovoran production and expression of both amylovoran (amsG) and T3SS (dspE and hrpL) genes were significantly higher in Ea273 and Ea110 than those in Ea1189 and CFBP1430. Other phenotypes such as swarming motility in these four strains also differed significantly. These results indicate that E. amylovora strains of different origin can be divided into subgroups based on molecular signatures of virulence gene expression. Therefore, these molecular signatures may be used to differentiate E. amylovora strains, which may have taxonomical and evolutionary implications.

  12. The first genotype determination of Acanthamoeba potential threat to human health, isolated from natural water reservoirs in Poland.

    PubMed

    Lass, Anna; Szostakowska, Beata; Idzińska, Alicja; Chomicz, Lidia

    2014-07-01

    Different species of amoebae belonging to the genus Acanthamoeba are widely distributed in many parts of the world and known as free-living organisms. Some strains of the protozoans may exist as parasites and cause risk to human health as causative agents of serious human diseases. Currently, in Poland, there is no sufficient information about the distribution of Acanthamoeba strains and their genotypes in the environment. Therefore, 20 environmental surface water samples were collected from different sites located at five water reservoirs in Gdynia, Sopot, and Gdańsk (northern Poland). The material was cultured to obtain Acanthamoeba isolates that were then specifically analyzed with both PCR and real-time PCR assays. Of the 20 samples examined, Acanthamoeba DNA was found in 13 samples tested with the use of real-time PCR; in 10 of them, DNA of the amoeba was also detected using PCR technique. The comparison with sequences available in the GenBank confirmed that the PCR products are fragments of Acanthamoeba 18S rRNA gene and that isolates represent T4 genotype, known as the most common strains related to AK cases. This is the first investigation in Poland describing Acanthamoeba detection in environmental water samples with molecular techniques and genotyping. The results indicate that surface water in Poland may be a source of acanthamoebic strains potentially pathogenic for humans.

  13. The Genotypic and Phenotypic Stability of Plasmodium falciparum Field Isolates in Continuous In Vitro Culture

    PubMed Central

    Yeda, Redemptah; Ingasia, Luicer A.; Cheruiyot, Agnes C.; Okudo, Charles; Chebon, Lorna J.; Cheruiyot, Jelagat; Akala, Hoseah M.; Kamau, Edwin

    2016-01-01

    The Plasmodium falciparum in vitro culture system is critical for genotypic and phenotypic analyses of the parasites. For genotypic analysis, the genomic DNA can be obtained directly from the patient blood sample or from culture adapted parasites whereas for phenotypic analysis, immediate ex vivo or in vitro culture adapted parasites are used. However, parasite biology studies have not investigated whether culture adaptation process affects genotypic and/or phenotypic characteristics of the parasites in short- or long-term cultures. Here, we set out to study the dynamics and stability of parasite genetic and phenotypic profiles as field isolate parasites were adapted in continuous cultures. Parasites collected from three different patients presenting with uncomplicated malaria were adapted and maintained in drug-free continuous cultures. Aliquots from the continuous cultures were collected every 24–48 hours for analyses. Each aliquot was treated as a separate parasite sample. For genetic analysis, microsatellite (MS) typing and single nucleotide polymorphism (SNP) analyses of 23 drug resistance markers were done. The 50% inhibitory concentrations (IC50) for some of the samples were also established for four antimalarial drugs. Samples from each patient (parasite-line) were compared as they were passed through the continuous culture. Data revealed genotypic and phenotypic profiles for the three parasite-lines fluctuated from one generation to the next with no specific pattern or periodicity. With few exceptions, multilocus analysis revealed samples from each parasite-line had high genetic diversity with unique haplotypes. Interestingly, changes in MS and SNP profiles occurred simultaneously. The difference in the IC50s of samples in each parasite-line reached statistical significance. However, phenotypic changes did not correspond or correlate to genotypic changes. Our study revealed parasite genetic and phenotypic characteristics fluctuates in short- and long

  14. Transmission of fish parasites into grouper mariculture (Serranidae: Epinephelus coioides (Hamilton, 1822)) in Lampung Bay, Indonesia.

    PubMed

    Rückert, Sonja; Klimpel, Sven; Al-Quraishy, Saleh; Mehlhorn, Heinz; Palm, Harry W

    2009-02-01

    Differently fed groupers Epinephelus coioides from an Indonesian finfish mariculture farm were studied for ecto- and endohelminth parasites. Pellet-fed E. coioides were infested with 13 parasite species/taxa of which six had a monoxenous and seven a heteroxenous life cycle. A total of 14 parasite species/taxa were found in the fish that were fed with different trash fish species, four of them with a monoxenous and ten with a heteroxenous life cycle. The use of pellet food significantly reduced the transfer of endohelminths and the number of parasites with a heteroxenous life cycle. Out of ten studied trash fish species, 62 parasite species were isolated (39% ectoparasitic and 61% endoparasitic), four of them also occurring in the cultured E. coioides and 14 in different groupers from Balai Budidaya Laut Lampung. The trash fish is held responsible for the transmission of these parasites into the mariculture fish. Endohelminth infestation of pellet fed fish demonstrates that parasite transfer also occurs via organisms that naturally live in, on, and in the surroundings of the net cages. Seventeen recorded invertebrates from the net cages might play an important role as intermediate hosts and hence parasite transmitters. The risk of parasite transfer can be considerably reduced by feeding selected trash fish species with a lower parasite burden, using only trash fish musculature or minimizing the abundance of invertebrates (fouling) on the net cages. These methods can control the endoparasite burden of cultivated fish without medication. The control of ectoparasites requires more elaborate techniques. Once they have succeeded in entering a mariculture farm, it is almost impossible to eliminate them from the system.

  15. A Screening Method for the Isolation of Polyhydroxyalkanoate-Producing Purple Non-sulfur Photosynthetic Bacteria from Natural Seawater

    PubMed Central

    Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Numata, Keiji

    2016-01-01

    Polyhydroxyalkanoates (PHAs) are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up. Gas chromatography mass spectrometry analysis revealed that four isolates synthesized PHA at levels ranging from 0.5 to 24.4 wt% of cell dry weight. The 16S ribosomal RNA sequence analysis revealed that one isolate (HM2) showed 100% identity to marine purple non-sulfur photosynthetic bacteria. In conclusion, we have demonstrated in this study that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions. PMID:27708640

  16. A Screening Method for the Isolation of Polyhydroxyalkanoate-Producing Purple Non-sulfur Photosynthetic Bacteria from Natural Seawater.

    PubMed

    Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Numata, Keiji

    2016-01-01

    Polyhydroxyalkanoates (PHAs) are a family of biopolyesters accumulated by a variety of microorganisms as carbon and energy storage under starvation conditions. We focused on marine purple non-sulfur photosynthetic bacteria as host microorganisms for PHA production and developed a method for their isolation from natural seawater. To identify novel PHA-producing marine purple non-sulfur photosynthetic bacteria, natural seawaters were cultured in nutrient-rich medium for purple non-sulfur photosynthetic bacteria, and twelve pink- or red-pigmented colonies were picked up. Gas chromatography mass spectrometry analysis revealed that four isolates synthesized PHA at levels ranging from 0.5 to 24.4 wt% of cell dry weight. The 16S ribosomal RNA sequence analysis revealed that one isolate (HM2) showed 100% identity to marine purple non-sulfur photosynthetic bacteria. In conclusion, we have demonstrated in this study that PHA-producing marine purple non-sulfur photosynthetic bacteria can be isolated from natural seawater under nutrient-rich conditions.

  17. Population genetics and natural selection in the gene encoding the Duffy binding protein II in Iranian Plasmodium vivax wild isolates.

    PubMed

    Valizadeh, Vahideh; Zakeri, Sedigheh; Mehrizi, Akram Abouie; Djadid, Navid Dinparast

    2014-01-01

    Region II of Duffy binding protein (PvDBP-II) is one of the most promising blood-stage vaccine candidate antigens against Plasmodium vivax and having knowledge of the nature and genetic polymorphism of PvDBP-II among global P. vivax isolates is important for developing a DBP-based vaccine. By using PCR and sequencing, the present molecular population genetic approach was carried out to investigate sequence diversity and natural selection of dbp-II gene in 63 P. vivax isolates collected from unstable and low transmission malaria-endemic areas of Iran during 2008-2012. Also, phylogenetic analysis, the diversifying natural selection, and recombination across the pvdbp-II gene, including regions containing B-cell epitopes were analyzed using the DnaSP and MEGA4 programs. Twenty two single nucleotide polymorphisms (SNPs, including 20 non-synonymous and 2 synonymous) were identified in PvDBP-II, resulting in 16 different PvDBP-II haplotypes among the Iranian P. vivax isolates. High binding inhibitory B-cell epitope (H3) overlapping with intrinsically unstructured/disordered region (aa: 384-392) appeared to be highly polymorphic (D384G/E385K/ K386N/Q/R390H), and positive selective pressure acted on this region. Most of the polymorphic amino acids, which are located on the surface of the protein, are under selective pressure that implies increased recombination events and exposure to the human immune system. In summary, PvDBP-II gene displays genetic polymorphism among Iranian P. vivax isolates and it is under selective pressure. Mutations, recombination, and positive selection seem to play a role in the resulting genetic diversity, and phylogenetic analysis of DNA sequences demonstrates that Iranian isolates represent a sample of the global population. These results are useful for understanding the nature of the P. vivax population in Iran and also for development of PvDBP-II-based malaria vaccine.

  18. Screening of natural yeast isolates under the effects of stresses associated with second-generation biofuel production.

    PubMed

    Dubey, Rajni; Jakeer, Shaik; Gaur, Naseem A

    2016-05-01

    Robust microorganisms are required for sustainable second-generation biofuel production. We evaluated the growth and fermentation performance of six natural isolates that were derived from grape wine and medicinal herbs using a wide range of carbon sources, rice and wheat straw hydrolysates as well as stress conditions associated with second-generation ethanol production. Sequence analysis of the 5.8S internal transcribed spacer (ITS) and species-specific PCR amplification of the HO gene region assigned the natural isolates to Saccharomyces cerevisiae. Restriction fragment length polymorphism (RFLP) analysis of the mitochondrial DNA revealed that natural yeast isolates are genetically closer to the laboratory strain BY4741 than to the CEN.PK strains. Dextrose fermentation by a natural isolate, MTCC4780, under semi-anaerobic conditions produced maximum ethanol yields of 0.44 g/g and 0.39 g/g, respectively, with and without the stresses encountered during lignocellulosic ethanol fermentation. However, MTCC4780 produced ethanol yields of 0.48 g/g, 0.42 g/g and 0.45 g/g, respectively, with glucose, rice and wheat straw enzymatic hydrolysate fermentation in a bioreactor. The isolates MTCC4781 and MTCC4796 showed higher growth and fermentation performance than did MTCC4780 in the presence of elevated temperature and pre-treatment inhibitors. Taken together, the MTCC4780, MTCC4781 and MTCC4796 strains have the potential to serve as a platform for lignocellulosic ethanol production under stresses associated with second-generation biofuel production.

  19. The project De Caldas International Project: An example of a large-scale radwaste isolation natural analogue study

    SciTech Connect

    Shea, M.

    1995-09-01

    The proper isolation of radioactive waste is one of today`s most pressing environmental issues. Research is being carried out by many countries around the world in order to answer critical and perplexing questions regarding the safe disposal of radioactive waste. Natural analogue studies are an increasingly important facet of this international research effort. The Pocos de Caldas Project represents a major effort of the international technical and scientific community towards addressing one of modern civilization`s most critical environmental issues - radioactive waste isolation.

  20. Malaria parasite development in mosquitoes.

    PubMed

    Beier, J C

    1998-01-01

    Mosquitoes of the genus Anopheles transmit malaria parasites to humans. Anopheles mosquito species vary in their vector potential because of environmental conditions and factors affecting their abundance, blood-feeding behavior, survival, and ability to support malaria parasite development. In the complex life cycle of the parasite in female mosquitoes, a process termed sporogony, mosquitoes acquire gametocyte-stage parasites from blood-feeding on an infected host. The parasites carry out fertilization in the midgut, transform to ookinetes, then oocysts, which produce sporozoites. Sporozoites invade the salivary glands and are transmitted when the mosquito feeds on another host. Most individual mosquitoes that ingest gametocytes do not support development to the sporozoite stage. Bottle-necks occur at every stage of the cycle in the mosquito. Powerful new techniques and approaches exist for evaluating malaria parasite development and for identifying mechanisms regulating malaria parasite-vector interactions. This review focuses on those interactions that are important for the development of new approaches for evaluating and blocking transmission in nature.

  1. Nature's Anti-Alzheimer's Drug: Isolation and Structure Elucidation of Galantamine from "Leucojum Aestivum"

    ERIC Educational Resources Information Center

    Halpin, Catherine M.; Reilly, Ciara; Walsh, John J.

    2010-01-01

    The discovery that galantamine penetrates the blood-brain barrier has led to its clinical use in the treatment of choline-deficiency conditions in the brain, such as Alzheimer's disease. This experiment involves the isolation and structure elucidation of galantamine from "Leucojum aestivum". Isolation of the alkaloid constituents in "L. aestivum"…

  2. Bioactive natural products from fungicolous Hawaiian isolates: Secondary metabolites from a Phialemoniopsis sp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical investigations of two fungal isolates initially identified as members of the genus Phialemonium are described. Both isolates were obtained as colonists of other fungi collected on the island of Hawaii and were later assigned as P. curvatum. However, P. curvatum has recently been reclassifie...

  3. Naturally Occurring β-Nicotinamide Adenine Dinucleotide-Independent Avibacterium paragallinarum Isolate in Peru.

    PubMed

    Falconi-Agapito, Francesca; Saravia, Luis E; Flores-Pérez, Aldo; Fernández-Díaz, Manolo

    2015-06-01

    The β-nicotinamide adenine dinucleotide (NAD) requirement has been considered to be essential for the isolation of the causal agent of infectious coryza, Avibacterium paragallinarum. Nevertheless, NAD-independent reports from South Africa and Mexico dismissed this paradigm. It is now accepted that both NAD-dependent and NAD-independent agents are able to cause infectious coryza and thus belong to the species A. paragallinarum. Here, we report for the first time in Peru a NAD-independent isolate from broiler chickens with typical signs of infectious coryza that have received a trivalent inactivated vaccine against infectious coryza. The isolate was identified based on its morphology, biochemical and serologic tests, and PCR results. Partial 16S rRNA gene sequence analysis confirmed the isolate as A. paragallinarum. There have been no cases of NAD-independent A. paragallinarum isolates reported in South America. Increasing reports around the world highlight not only the need to reconsider the in vitro nutritional requirements of this species for its correct isolation but also the cross-protection conferred by commercial infectious coryza vaccines against NAD-independent isolates.

  4. Enzyme polymorphism, prodigiosin production, and plasmid fingerprints in clinical and naturally occurring isolates of Serratia marcescens.

    PubMed Central

    Gargallo-Viola, D

    1989-01-01

    Enzyme polymorphism and genetic relationship among 99 Serratia marcescens isolates obtained from clinical and environmental sources were determined by analysis of electromorphs in nine enzyme loci encoded by chromosomal genes. Seven of the loci were polymorphic, and 33 distinctive electrophoretic types (ETs) representing multilocus genotypes were identified. Cluster analysis, based on the proportion of mismatches between multilocus genotypes, revealed two clearly differentiated groups of ETs in S. marcescens. One was represented exclusively by isolates with nonchromogenic biotypes recovered almost entirely (97.3%) from clinical samples. The other group comprised all isolates characterized by the production of prodigiosin or by belonging to a chromogenic biotype. Absolute correlation was found between the ability to produce prodigiosin and the absence of plasmids. In contrast, 24% of the nonchromogenic isolates contained plasmids. Results obtained by analysis of multilocus genotypes were related to those obtained by biotyping and plasmid fingerprinting. However, more groups could be distinguished by analysis of ETs than by biotyping. Plasmid fingerprinting was a limited typing system because many isolates lacked plasmids. Although the results of this study did not permit a definitive correlation between ETs and pathogenicity of the isolates, more detailed studies of these groups will help to understand the different clinical significances of the nonchromogenic and chromogenic isolates of S. marcescens. PMID:2663918

  5. Genetic analysis and natural polymorphisms in HIV-1 gp41 isolates from Maputo City, Mozambique.

    PubMed

    Ismael, Nália; Bila, Dulce; Mariani, Diana; Vubil, Adolfo; Mabunda, Nedio; Abreu, Celina; Jani, Ilesh; Tanuri, Amilcar

    2014-06-01

    Enfuvirtide was the first fusion inhibitor approved by the Food and Drug Administration (FDA) in 2003 for HIV-1 infection in treatment-experienced patient. It is the first approved antiviral agent to attack the HIV life cycle in its early stages. For HIV fusion to occur, the HR1 and HR2 domains in the gp41 region need to interact. Enfuvirtide is a synthetic peptide that corresponds to 36 amino acids of the HR2, which competitively binds to HR1 inhibiting the interaction with the HR2 domain thus preventing fusogenic conformation and inhibiting viral entry into host cells. Resistance to enfuvirtide is conferred by mutations occurring in the HR1 region involving residues 36-45. Mozambique, a sub-Saharan country, with an HIV prevalence of 11.5%, provides first line and second line antiretroviral therapy (ART)-based treatment. In poor resource settings such as Mozambique the lack of adequate infrastructures, the high costs of viral load tests, and the availability of salvage treatment have hindered the intended objective of monitoring HIV treatment, suggesting an important concern regarding the development of drug resistance. The general aim of this study was to evaluate naturally occurring polymorphisms and resistance-associated mutations in the gp41 region of HIV-1 isolates from Mozambique. The study included 78 patients naive to ARV treatment and 28 patients failing first line regimen recruited from Centro de Saúde Alto-Maé situated in Maputo. The gp41 gene from 103 patients was sequenced and resistance-associated mutations for enfuvirtide were screened. Subtype analysis revealed that 96% of the sequences were classified as subtype C, 2% as subtype G, 1% as subtype A1, and the other 1% as a mosaic form composed of A1/C. No enfuvirtide resistance-associated mutations in HR1 of gp41 were detected. The major polymorphisms in the HR1 were N42S, L54M, A67T, and V72I. This study suggests that this new class of antiviral drug may be effective as a salvage therapy in

  6. Random parasite encounters coupled with condition-linked immunity of hosts generate parasite aggregation.

    PubMed

    Morrill, André; Forbes, Mark R

    2012-06-01

    Parasite aggregation is viewed as a natural law in parasite-host ecology but is a paradox insofar as parasites should follow the Poisson distribution if hosts are encountered randomly. Much research has focused on whether parasite aggregation in or on hosts is explained by aggregation of infective parasite stages in the environment, or by heterogeneity within host samples in terms of host responses to infection (e.g., through representation of different age classes of hosts). In this paper, we argue that the typically aggregated distributions of parasites may be explained simply. We propose that aggregated distributions can be derived from parasites encountering hosts randomly, but subsequently by parasites being 'lost' from hosts based on condition-linked escape or immunity of hosts. Host condition should be a normally distributed trait even among otherwise homogeneous sets of hosts. Our model shows that mean host condition and variation in host condition have different effects on the different metrics of parasite aggregation. Our model further predicts that as host condition increases, parasites become more aggregated but numbers of attending parasites are reduced overall and this is important for parasite population dynamics. The effects of deviation from random encounter are discussed with respect to the relationship between host condition and final parasite numbers.

  7. Isolation of nonvolatile, organic solutes from natural waters by zeotrophic distillation of water from N,N-dimethylformamide

    SciTech Connect

    Leenheer, J.A.; Brown, P.A.; Stiles, E.A.

    1987-05-01

    Nonvolatile, organic solutes that comprise the dissolved organic carbon (DOC) in saline waters were isolated by removal of the water by distillation from a N,N-dimethylformamide-formic acid-acetonitrile mixture. Salts isolated with the DOC were removed by crystallization of sodium chloride and sodium sulfate from the solvent mixture, removal of silicic acid by acidification and precipitation, removal of boric acid by methylation and volatilization, and removal of phosphate by zinc acetate precipitation. Chemical alteration of the organic solutes was minimized during evaporative concentration steps by careful control of acid concentrations in the solvent mixture and was minimized during drying by conversion of the samples to pyridinium and sodium salts. Recoveries of various hydrophilic organic standards from aqueous salt solutions and recoveries of natural organic solutes from various water samples varied from 60 to 100%. Losses of organic solutes during the isolation procedure were nonselective and related to the number of salt- and precipitate-washing cycles in the procedure.

  8. Isolation of nonvolatile, organic solutes from natural waters by zeotrophic distillation of water from N,N-dimethylformamide

    USGS Publications Warehouse

    Leenheer, J.A.; Brown, P.A.; Stiles, E.A.

    1987-01-01

    Nonvolatile, organic solutes that comprise the dissolved organic carbon (DOC) in saline waters were isolated by removal of the water by distillation from a N,N-dimethylformamideformic acid-acetonitrile mixture. Salts isolated with the DOC were removed by crystallization of sodium chloride and sodium sulfate from the solvent mixture, removal of silicic acid by acidification and precipitation, removal of boric acid by methylation and volatilization, and removal of phosphate by zinc acetate precipitation. Chemical alteration of the organic solutes was minimized during evaporative concentration steps by careful control of acid concentrations in the solvent mixture and was minimized during drying by conversion of the samples to pyridinium and sodium salts. Recoveries of various hydrophilic organic standards from aqueous salt solutions and recoveries of natural organic solutes from various water samples varied from 60 to 100%. Losses of organic solutes during the isolation procedure were nonselective and related to the number of salt- and precipitate-washing cycles in the procedure.

  9. Oscheius tipulae in Italy: Evidence of an Alien Isolate in the Integral Natural Reserve of Montecristo Island (Tuscany)

    PubMed Central

    Torrini, Giulia; Mazza, Giuseppe; Strangi, Agostino; Barabaschi, Delfina; Landi, Silvia; Mori, Emiliano; Menchetti, Mattia; Sposimo, Paolo; Giuliani, Claudia; Zoccola, Antonio; Lazzaro, Lorenzo; Ferretti, Giulio; Foggi, Bruno; Roversi, Pio Federico

    2016-01-01

    Montecristo Island is an integral natural reserve of the Tuscan Archipelago National Park (Central Italy), characterized by a peculiar assemblage of flora and fauna, with several endemic taxa, and also with a high number of alien species. During a soil survey, we found an alien Oscheius tipulae Lam & Webster, 1971 isolate, phylogenetically close to others from South America. In this article, we examined the possible pathways of introduction of this nematode. Because of the high number of alien plants in this protected area and the low desiccation survival ability of O. tipulae, we hypothesized that the presence of this alien nematode isolate may be related to the soil of introduced plants, although historical association with plant-associated invertebrates is also possible. Further studies with more populations and marker molecules are necessary to investigate the distribution of O. tipulae and the possible impact on this natural reserve. PMID:27168647

  10. Oscheius tipulae in Italy: Evidence of an Alien Isolate in the Integral Natural Reserve of Montecristo Island (Tuscany).

    PubMed

    Torrini, Giulia; Mazza, Giuseppe; Strangi, Agostino; Barabaschi, Delfina; Landi, Silvia; Mori, Emiliano; Menchetti, Mattia; Sposimo, Paolo; Giuliani, Claudia; Zoccola, Antonio; Lazzaro, Lorenzo; Ferretti, Giulio; Foggi, Bruno; Roversi, Pio Federico

    2016-03-01

    Montecristo Island is an integral natural reserve of the Tuscan Archipelago National Park (Central Italy), characterized by a peculiar assemblage of flora and fauna, with several endemic taxa, and also with a high number of alien species. During a soil survey, we found an alien Oscheius tipulae Lam & Webster, 1971 isolate, phylogenetically close to others from South America. In this article, we examined the possible pathways of introduction of this nematode. Because of the high number of alien plants in this protected area and the low desiccation survival ability of O. tipulae, we hypothesized that the presence of this alien nematode isolate may be related to the soil of introduced plants, although historical association with plant-associated invertebrates is also possible. Further studies with more populations and marker molecules are necessary to investigate the distribution of O. tipulae and the possible impact on this natural reserve.

  11. Bioactive natural products from fungicolous Hawaiian isolates: secondary metabolites from a Phialemoniopsis sp.

    PubMed Central

    Kaur, Amninder; Rogers, Kristina D.; Swenson, Dale E.; Dowd, Patrick F.; Wicklow, Donald T.; Gloer, James B.

    2014-01-01

    Chemical investigations of two fungal isolates initially identified as members of the genus Phialemonium are described. Both isolates were obtained as colonists of other fungi collected on the island of Hawaii and were later assigned as P. curvatum. However, P. curvatum has recently been reclassified as a member of a new genus (Phialemoniopsis) and renamed as Phialemoniopsis curvata. Studies of solid–substrate fermentation cultures of one of these isolates afforded an oxirapentyn analogue and destruxin A4 as major components, while analysis of the second strain led to the isolation of several simple aromatic metabolites and a compound of mixed biogenetic origin called gabusectin that had previously been reported only in a patent. Structures were assigned mainly by detailed nuclear magnetic resonance and mass spectrometry analysis, and those of two of the major components were confirmed by X-ray crystallography. This report constitutes the first description of secondary metabolites from a member of the genus Phialemoniopsis. PMID:25379336

  12. Characterization of Diazotrophs Containing Mo-Independent Nitrogenases, Isolated from Diverse Natural Environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molybdenum-independent nitrogenases were first described in the nitrogen-fixing bacterium Azotobacter vinelandii and have since been described in other diazotrophic bacteria. Previously, we reported the isolation of seven diazotrophs with Molybdenum-independent nitrogenases from aquatic environments...

  13. Isolation, biological activity, synthesis, and medicinal chemistry of the pederin/mycalamide family of natural products.

    PubMed

    Mosey, R Adam; Floreancig, Paul E

    2012-09-01

    This review highlights the broad range of science that has arisen from the isolation of pederin, the mycalamides, theopederins, and onnamides, and psymberin. Specific topics include structure determination, biological activity, synthesis, and analog preparation and analysis.

  14. Antifungal Activity of Lactic Acid Bacteria Strains Isolated from Natural Honey against Pathogenic Candida Species

    PubMed Central

    Bulgasem, Bulgasem Y.; Lani, Mohd Nizam; Wan Yusoff, Wan Mohtar; Fnaish, Sumaya G.

    2016-01-01

    The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly (p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly (p < 0.05) effective against C. krusei, C. glabrata, and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species. PMID:28154488

  15. Antifungal Activity of Lactic Acid Bacteria Strains Isolated from Natural Honey against Pathogenic Candida Species.

    PubMed

    Bulgasem, Bulgasem Y; Lani, Mohd Nizam; Hassan, Zaiton; Wan Yusoff, Wan Mohtar; Fnaish, Sumaya G

    2016-12-01

    The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly (p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly (p < 0.05) effective against C. krusei, C. glabrata, and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species.

  16. Human intestinal parasites in non-biting synanthropic flies in Ogun State, Nigeria.

    PubMed

    Adenusi, Adedotun Adesegun; Adewoga, Thomas O Sunday

    2013-01-01

    Filth-feeding and breeding, non-biting synanthropic flies have been incriminated in the dissemination of human enteropathogens in the environment. This study determined the species of non-biting synanthropic flies associated with four filthy sites in Ilishan, Ogun State, southwest Nigeria, and assessed their potentials for mechanical transmission of human intestinal parasites. 7190 flies identified as Musca domestica (33.94%), Chrysomya megacephala (26.01%), Musca sorbens (23.23%), Lucilia cuprina (8.76%), Calliphora vicina (4.59%), Sarcophaga sp. (2.78%) and Fannia scalaris (0.70%) were examined for human intestinal parasites by the formol-ether concentration and modified Ziehl-Neelsen techniques. Eggs of the following parasites: Ascaris lumbricoides (34.08%), Trichuris trichiura (25.87%), hookworms (20.45%), Taenia sp. (2.36%), Hymenolepis nana (1.11%), Enterobius vermicularis (0.56%), Strongyloides stercoralis (larvae; 3.89%) and cysts of Entamoeba histolytica/dispar (27.26%), Entamoeba coli (22.67%), Giardia lamblia (3.34%) and Cryptosporidium sp. (1.81%) were isolated from the body surfaces and or gut contents of 75.24% of 719 pooled fly batches. The helminths A. lumbricoides and T. trichiura and the protozoans, E. histolytica/dispar and E. coli were the dominant parasites detected, both on body surfaces and in the gut contents of flies. C. megacephala was the highest carrier of parasites (diversity and number). More parasites were isolated from the gut than from body surfaces (P < 0.05). Flies from soiled ground often carried more parasites than those from abattoir, garbage or open-air market. Synanthropic fly species identified in this study can be of potential epidemiological importance as mechanical transmitters of human intestinal parasites acquired naturally from filth and carried on their body surfaces and or in the gut, because of their vagility and feeding mechanisms.

  17. Hosts and parasites as aliens.

    PubMed

    Taraschewski, H

    2006-06-01

    Over the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. In general this happened to a low extent for hundreds of years. With variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. In the literature thus far, colonizations by both hosts and parasites have not been treated and reviewed together, although both are usually interwoven in various ways. As to those factors permitting invasive success and colonization strength, various hypotheses have been put forward depending on the scientific background of respective authors and on the conspicuousness of certain invasions. Researchers who have tried to analyse characteristic developmental patterns, the speed of dispersal or the degree of genetic divergence in populations of alien species have come to different conclusions. Among parasitologists, the applied aspects of parasite invasions, such as the negative effects on economically important hosts, have long been at the centre of interest. In this contribution, invasions by hosts as well as parasites are considered comparatively, revealing many similarities and a few differences. Two helminths, the liver fluke, Fasciola hepatica, of cattle and sheep and the swimbladder nematode, Anguillicola crassus, of eels are shown to be useful as model parasites for the study of animal invasions and environmental global change. Introductions of F. hepatica have been associated with imports of cattle or other grazing animals. In various target areas, susceptible lymnaeid snails serving as intermediate hosts were either naturally present and/or were introduced from the donor continent of the parasite (Europe) and/or from other regions which were not within the original range of the parasite, partly reflecting progressive stages of a global biota change. In several

  18. Fabrication and investigation on field-dependent properties of natural rubber based magneto-rheological elastomer isolator

    NASA Astrophysics Data System (ADS)

    Ain Abd Wahab, Nurul; Amri Mazlan, Saiful; Ubaidillah; Kamaruddin, Shamsul; Intan Nik Ismail, Nik; Choi, Seung-Bok; Haziq Rostam Sharif, Amirul

    2016-10-01

    This study presents a laminated magnetorheological elastomer (MRE) isolator which applies to vibration control in practice. The proposed isolator is fabricated with multilayer MRE sheets associated with the natural rubber (NR) as a matrix, and steel plates. The fabricated MRE isolator is then magnetically analysed to achieve high magnetic field intensity which can produce high damping force required for effective vibration control. Subsequently, the NR-based MRE specimen is tested to identify the field-dependent rheological properties such as storage modulus with 60 weight percentage of carbonyl iron particles. It is shown from this test that the MR effect of MRE specimen is quantified to reach up to 120% at 0.8 T. Following the design stage, the electromagnetic simulation using the finite element method magnetic (FEMM) software is carried out for analysing the magnetic flux distribution in the laminated MRE isolator. The laminated MRE isolator is then examined to a series of compression for static and dynamic test under various applied currents using the dynamic fatigue machine and biaxial dynamic testing machine. It is shown that the static compression force is increased by 14.5% under strong magnetic field compared to its off-state. Meanwhile, the dynamic compression test results show that the force increase of the laminated MRE isolator is up to 16% and 7% for low and high frequency respectively. From the results presented in this work, it is demonstrated that the full-scale concept of the MRE isolator can be one of the potential candidates for vibration control applications by tunability of the dynamic stiffness.

  19. The complete genome sequences of two naturally occurring recombinant isolates of Sugarcane mosaic virus from Iran.

    PubMed

    Moradi, Zohreh; Mehrvar, Mohsen; Nazifi, Ehsan; Zakiaghl, Mohammad

    2016-04-01

    Sugarcane mosaic virus (SCMV) is the most prevalent virus causing sugarcane mosaic and maize dwarf mosaic diseases. Here, we presented the first two complete genomic sequences of Iranian SCMV isolates, NRA and ZRA from sugarcane and maize. The complete genome sequences of NRA and ZRA were, respectively, 9571 and 9572 nucleotides (nt) in length, excluding the 3'-terminal poly(A) tail. Both isolates contained a 5'-untranslated region (UTR) of 149 nt, an open reading frame of 9192 nt encoding a polyprotein of 3063 amino acids (aa), and 3'-UTR of 230 nt for NRA and 231 nt for ZRA. SCMV-NRA and -ZRA genome nucleotide sequences were 97.3 % identical and shared nt identities of 79.1-92 % with those of other 21 SCMV isolates available in the GenBank, highest with the isolate Bris-A (AJ278405) (92 and 91.7 %) from Australia. When compared for separate genes, most of their genes shared the highest identities with Australian and Argentinean isolates. Phylogenetic analysis of the complete genomic sequences reveals that SCMV can be clustered to three groups. Both NRA and ZRA were clustered with sugarcane isolates from Australia and Argentina in group III but formed a separate sublineage. Recombination analysis showed that both isolates were intraspecific recombinants, and represented two novel recombination patterns of SCMV (in the P1 coding region). NRA had six recombination sites within the P1, HC-Pro, CI, NIa-Vpg, and NIa-pro coding regions, while ZRA had four within the P1, HC-Pro, NIa-Pro, and NIb coding regions.

  20. Piper aduncum against Haemonchus contortus isolates: cross resistance and the research of natural bioactive compounds.

    PubMed

    Gaínza, Yousmel Alemán; Fantatto, Rafaela Regina; Chaves, Francisco Celio Maia; Bizzo, Humberto Ribeiro; Esteves, Sérgio Novita; Chagas, Ana Carolina de Souza

    2016-01-01

    The anthelminthic activity of the essential oil (EO) of Piper aduncum L. was tested in vitro on eggs and larvae of resistant (Embrapa2010) and susceptible (McMaster) isolates of Haemonchus contortus. The EO was obtained by steam distillation and its components identified by chromatography. EO concentrations of 12.5 to 0.02 mg/mL were used in the egg hatch test (EHT) and concentrations of 3.12 to 0.01 mg/mL in the larval development test (LDT). Inhibition concentrations (IC) were determined by the SAS Probit procedure, and significant differences assessed by ANOVA followed by Tukey's test. In the EHT, the IC50 for the susceptible isolate was 5.72 mg/mL. In the LDT, the IC50 and IC90 were, respectively, 0.10 mg/mL and 0.34 mg/mL for the susceptible isolate, and 0.22 mg/mL and 0.51 mg/mL for the resistant isolate. The EO (dillapiole 76.2%) was highly efficacious on phase L1. Due to the higher ICs obtained for the resistant isolate, it was raised the hypothesis that dillapiole may have a mechanism of action that resembles those of other anthelmintic compounds. We further review and discuss studies, especially those conducted in Brazil, that quantified the major constituents of P. aduncum-derived EO.

  1. Genetic Diversity of a Natural Population of Apple stem pitting virus Isolated from Apple in Korea.

    PubMed

    Yoon, Ju Yeon; Joa, Jae Ho; Choi, Kyung San; Do, Ki Seck; Lim, Han Cheol; Chung, Bong Nam

    2014-06-01

    Apple stem pitting virus (ASPV), of the Foveavirus genus in the family Betaflexiviridae, is one of the most common viruses of apple and pear trees. To examine variability of the coat protein (CP) gene from ASPV, eight isolates originating from 251 apple trees, which were collected from 22 apple orchards located in intensive apple growing areas of the North Gyeongsang and North Jeolla Provinces in Korea, were sequenced and compared. The nucleotide sequence identity of the CP gene of eight ASPV isolates ranged from 77.0 to 97.0%, while the amino acid sequence identity ranged from 87.7 to 98.5%. The N-terminal region of the viral CP gene was highly variable, whereas the C-terminal region was conserved. Genetic algorithm recombination detection (GARD) and single breakpoint recombination (SBP) analyses identified base substitutions between eight ASPV isolates at positions 54 and 57 and position 771, respectively. GABranch analysis was used to determine whether the eight isolates evolved due to positive selection. All values in the GABranch analysis showed a ratio of substitution rates at non-synonymous and synonymous sites (dNS/dS) below 1, suggestive of strong negative selection forces during ASPV CP history. Although negative selection dominated CP evolution in the eight ASPV isolates, SLAC and FEL tests identified four possible positive selection sites at codons 10, 22, 102, and 158. This is the first study of the ASPV genome in Korea.

  2. Bacterial Endophytes Isolated from Plants in Natural Oil Seep Soils with Chronic Hydrocarbon Contamination

    PubMed Central

    Lumactud, Rhea; Shen, Shu Yi; Lau, Mimas; Fulthorpe, Roberta

    2016-01-01

    The bacterial endophytic communities of four plants growing abundantly in soils highly contaminated by hydrocarbons were analyzed through culturable and culture-independent means. Given their tolerance to the high levels of petroleum contamination at our study site, we sought evidence that Achillea millefolium, Solidago canadensis, Trifolium aureum, and Dactylis glomerata support high levels of hydrocarbon degrading endophytes. A total of 190 isolates were isolated from four plant species. The isolates were identified by partial 16S rDNA sequence analysis, with class Actinobacteria as the dominant group in all species except S. canadensis, which was dominated by Gammaproteobacteria. Microbacterium foliorum and Plantibacter flavus were present in all the plants, with M. foliorum showing predominance in D. glomerata and both endophytic bacterial species dominated T. aureum. More than 50% of the isolates demonstrated degradative capabilities for octanol, toluene, naphthalene, kerosene, or motor oil based on sole carbon source growth screens involving the reduction of tetrazolium dye. P. flavus isolates from all the sampled plants showed growth on all the petroleum hydrocarbons (PHCs) substrates tested. Mineralization of toluene and naphthalene was confirmed using gas-chromatography. 16S based terminal restriction fragment length polymorphism analysis revealed significant differences between the endophytic bacterial communities showing them to be plant host specific at this site. To our knowledge, this is the first account of the degradation potential of bacterial endophytes in these commonly occurring pioneer plants that were not previously known as phytoremediating plants. PMID:27252685

  3. Arsenic resistance and accumulation by two bacteria isolated from a natural arsenic contaminated site.

    PubMed

    Pandey, Neha; Bhatt, Renu

    2015-11-01

    Forty-three indigenous arsenic resistant bacteria were isolated from arsenic rich soil of Rajnandgaon district in the state of Chhattisgarh, India by enrichment culture technique. Among the isolates, two of the bacteria (As-9 and As-14) exhibited high resistance to As(V) [MIC ≥ 700 mM] and As(III) [MIC ≥ 10 mM] and were selected for further studies. Both these bacteria grew well in the presence of arsenic [20 mM As(V) and 5 mM As(III)], but the isolate As-14 strictly required arsenic for its survival and growth and was characterized as a novel arsenic dependent bacterium. The isolates contributed to 99% removal of arsenic from the growth medium which was efficiently accumulated in the cell. Quantitative estimation of arsenic through Atomic Absorption Spectrophotometer revealed that there was >60% accumulation of both As(V) and As(III) by the two isolates. Scanning Electron Microscopic analysis showed a fourfold increase in bacterial cell volume when grown in the presence of arsenic and the results of Transmission Electron Microscopy and energy-dispersive X-ray spectroscopy proved that such an alteration was due to arsenic accumulation. Such arsenic resistant bacteria with efficient accumulating property could be effectively applied in the treatment of arsenic contaminated water.

  4. Isolation, structural characterization and in silico drug-like properties prediction of a natural compound from the ethanolic extract of Cayratia trifolia (L.)

    PubMed Central

    Perumal, Palanisamy Chella; Sowmya, Sundaram; Pratibha, Prabhakaran; Vidya, Balasubramanian; Anusooriya, Palanirajan; Starlin, Thangarajan; Ravi, Subban; Gopalakrishnan, Velliyur Kanniappan

    2015-01-01

    Background: Natural products have continually played an important role in drug discovery because it serves as active principles in drugs as well as templates for synthesis of new drugs. Cayratia trifolia (L.) is a medicinal plant, which has been reported to have antiviral, antibacterial, antiprotozoal, hypoglycemic, anticancer and diuretic activities. Objective: Therefore, the objective of this study is to isolate and identify the natural compound from the ethanolic extract of Cayratia trifolia (L.) and to predict the Absorption, Distribution, Metabolism and Excretion (ADME) properties of isolated natural compound. Materials and Methods: Column chromatography and thin layer chromatography were used to isolate the natural compound and Fourier-transform infrared (FTIR) spectroscopy was used to predict the functional groups present in the isolated natural compound. The structural characterization studies were functionally carried out using 1H, 13C, two-dimensional nuclear magnetic resonance (NMR) and mass spectrometry methods. Results: FTIR showed that, the groups of OH, C-H, C = C may be present in the isolated natural compound. 1H, 13C, two-dimensional NMR and mass spectrometry data suggests that the isolated natural compound probably like linoleic acid. In silico ADME properties, prediction of the compound was under acceptable range. Conclusion: Based on the results, it can be concluded that, the isolated natural compound of linoleic acid that has been exhibited good medicinal properties. PMID:25598646

  5. Isolation and molecular characterization of Orf virus from natural outbreaks in goats of Assam.

    PubMed

    Bora, Mousumi; Bora, Durlav Prasad; Barman, Nagendra Nath; Borah, Biswajyoti; Bora, Padma Lochan; Talukdar, Archana; Tamuly, Shantanu

    2015-06-01

    Outbreaks of contagious ecthyma (caused by a Parapox virus) in goats were investigated in 6 districts of Assam, a north eastern state of India. Diagnosis of the disease was carried out employing both standard virological as well as molecular methods. Four representative isolates from different places were selected for phylogenetic analysis. The major envelop protein (B2L) of Orf virus was targeted for molecular analysis. The sequencing and phylogenetic analysis of the selected sequences at nucleotide level revealed that the Orf virus isolates were closely related to each other (97.6-100 %) and showed highest similarity to the Orf virus isolate 82/04 (98.4 %), reported from Shahjahanpur, India. The data will provide an insight in transmission of the virus from northern to North eastern part of the country.

  6. Association between variation in faecal egg count for a natural mixed field-challenge of nematode parasites and TLR4 variation.

    PubMed

    Lin, Y-S; Zhou, H; Forrest, R H J; Frampton, C M; Burrows, L E R; Hickford, J G H

    2016-03-15

    Research has shown that Toll-like receptor 4 (TLR4) is important in immune responses to some helminth parasites. In sheep, variation in the PAMP region of TLR4 may result in structurally and thus functionally different TLR4 molecules, and this may consequently lead to variation in the TLR4 response to parasite infections. This study involved three separate, but related sheep breeds (Merino, Polwarth and Corriedale sheep) and a total of 885 lambs from five New Zealand farms that underwent a mixed field-challenge from gastro-intestinal parasites. Faecal samples were collected at approximately 4 and 9 months of age and faecal egg counts (FECs) for Nematodirus spp. and Strongyle species determined, along with the total number of eggs per gram (EPG). Analysis of the five farms collectively revealed an association (P=0.023) between the presence of TLR4 variant *02 (mean 24 EPG) and the absence of the variant (mean 32 EPG) at 9 months of age. Conversely the presence of *03 had a significantly (P=0.047) higher mean Nematodirus spp. FEC (mean 42 EPG) compared to the absence (mean 28 EPG) at 9 months of age. More associations were revealed when the data were split according to the dominant faecal parasite species. With a predominantly Trichostrongylus spp. FEC group of lambs at 9 months of age, the presence of TLR4 variant *02 was found to have significantly (P=0.003) lower Nematodirus spp. FEC (mean 4 EPG), and also significantly (P=0.033) lower total FEC (mean 312 EPG) when compared to sheep without the variant (mean 15 EPG and 449 EPG, respectively). The presence of TLR4 variant *03 and *04 were associated or tended to be associated (P=0.010 and P=0.088, respectively) with higher Nematodirus spp. FEC (mean 25 EPG and 22 EPG, respectively) when compared to lambs without the variant (mean 10 EPG and 11 EPG, respectively). These results suggest that TLR4 variation may be affecting the immune response to gastro-intestinal parasites in sheep, although principally to

  7. Variable effects of nicotine, anabasine, and their interactions on parasitized bumble bees

    PubMed Central

    Thorburn, Lukas P.; Adler, Lynn S.; Irwin, Rebecca E.; Palmer-Young, Evan C.

    2015-01-01

    Secondary metabolites in floral nectar have been shown to reduce parasite load in two common bumble bee species. Previous studies on the effects of nectar secondary metabolites on parasitized bees have focused on single compounds in isolation; however, in nature, bees are simultaneously exposed to multiple compounds. We tested for interactions between the effects of two alkaloids found in the nectar of Nicotiana spp. plants, nicotine and anabasine, on parasite load and mortality in bumble bees ( Bombus impatiens) infected with the intestinal parasite Crithidia bombi. Adult worker bees inoculated with C. bombi were fed nicotine and anabasine diet treatments in a factorial design, resulting in four nectar treatment combinations:  2 ppm nicotine, 5 ppm anabasine, 2ppm nicotine and 5 ppm anabasine together, or a control alkaloid-free solution. We conducted the experiment twice: first, with bees incubated under variable environmental conditions (‘Variable’; temperatures varied from 10-35°C with ambient lighting); and second, under carefully controlled environmental conditions (‘Stable’; 27°C incubator, constant darkness). In ‘Variable’, each alkaloid alone significantly decreased parasite loads, but this effect was not realized with the alkaloids in combination, suggesting an antagonistic interaction. Nicotine but not anabasine significantly increased mortality, and the two compounds had no interactive effects on mortality. In ‘Stable’, nicotine significantly increased parasite loads, the opposite of its effect in ‘Variable’. While not significant, the relationship between anabasine and parasite loads was also positive. Interactive effects between the two alkaloids on parasite load were non-significant, but the pattern of antagonistic interaction was similar to that in the variable experiment. Neither alkaloid, nor their interaction, significantly affected mortality under controlled conditions. Our results do not indicate synergy between Nicotiana

  8. Host-Parasite Interactions in Chagas Disease: Genetically Unidentical Isolates of a Single Trypanosoma cruzi Strain Identified In Vitro via LSSP-PCR

    PubMed Central

    Nogueira-Paiva, Nívia Carolina; Vieira, Paula Melo de Abreu; Oliveri, Larissa Maris Rezende; Fonseca, Kátia da Silva; Pound-Lana, Gwenaelle; de Oliveira, Maykon Tavares; de Lana, Marta; Veloso, Vanja Maria; Reis, Alexandre Barbosa; Carneiro, Cláudia Martins

    2015-01-01

    The present study aims at establishing whether the diversity in pathogenesis within a genetically diverse host population infected with a single polyclonal strain of Trypanosoma cruzi is due to selection of specific subpopulations within the strain. For this purpose we infected Swiss mice, a genetically diverse population, with the polyclonal strain of Trypanosoma cruzi Berenice-78 and characterized via LSSP-PCR the kinetoplast DNA of subpopulations isolated from blood samples collected from the animals at various times after inoculation (3, 6 and 12 months after inoculation). We examined the biological behavior of the isolates in acellular medium and in vitro profiles of infectivity in Vero cell medium. We compared the characteristics of the isolates with the inoculating strain and with another strain, Berenice 62, isolated from the same patient 16 years earlier. We found that one of the isolates had intermediate behavior in comparison with Berenice-78 and Berenice-62 and a significantly different genetic profile by LSSP-PCR in comparison with the inoculating strain. We hereby demonstrate that genetically distinct Trypanosoma cruzi isolates may be obtained upon experimental murine infection with a single polyclonal Trypanosoma cruzi strain. PMID:26359864

  9. Blood parasites from California ducks and geese

    USGS Publications Warehouse

    Herman, C.M.

    1951-01-01

    Blood smears were procured from 1,011 geese and ducks of 19 species from various locations in California. Parasites were found in 28 individuals. The parasites observed included Haemoproteus hermani, Leucocytozoon simondi, microfilaria, Plasmodium relictum (=P. biziurae), and Plasmodium sp. with elongate gametocytes. This is the first report of a natural infection with a Plasmodium in North American wild ducks.

  10. Biological invasions and host-parasite coevolution: different coevolutionary trajectories along separate parasite invasion fronts.

    PubMed

    Feis, Marieke E; Goedknegt, M Anouk; Thieltges, David W; Buschbaum, Christian; Wegner, K Mathias

    2016-08-01

    Host-parasite coevolution has rarely been observed in natural systems. Its study often relies on microparasitic infections introducing a potential bias in the estimation of the evolutionary change of host and parasite traits. Using biological invasions as a tool to study host-parasite coevolution in nature can overcome these biases. We demonstrate this with a cross-infection experiment in the invasive macroparasite Mytilicola intestinalis and its bivalve host, the blue mussel Mytilus edulis. The invasion history of the parasite is well known for the southeastern North Sea and is characterised by two separate invasion fronts that reached opposite ends of the Wadden Sea (i.e. Texel, The Netherlands and Sylt, Germany) in a similar time frame. The species' natural history thus makes this invasion an ideal natural experiment to study host-parasite coevolution in nature. We infected hosts from Texel, Sylt and Kiel (Baltic Sea, where the parasite is absent) with parasites from Texel and Sylt, to form sympatric, allopatric and naïve infestation combinations, respectively. We measured infection rate, host condition and parasite growth to show that sympatric host-parasite combinations diverged in terms of pre- and post-infection traits within <100 generations since their introduction. Texel parasites were more infective and more efficient at exploiting the host's resources. Hosts on Texel, on the other hand, evolved resistance to infection, whereas hosts on Sylt may have evolved tolerance. This illustrates that different coevolutionary trajectories can evolve along separate invasion fronts of the parasite, highlighting the use of biological invasions in studies of host-parasite coevolution in nature.

  11. Protozoan Parasites.

    PubMed

    Custodio, Haidee

    2016-02-01

    • Stool antigen detection for Cryptosporidium sp, Giardia lamblia and Entamoeba histolytica are now commercially available, have better sensitivity and specificity than the traditional stool microscopy, and are less dependent on personnel skill. Tests employing newer techniques with faster turnaround time are also available for diagnosing trichomoniasis.• Nitazoxanide, the only U.S. Food and Drug Administration-approved medication for therapy of cryptosporidiosis, is effective among immunocompetent patients. However, on the basis of strong evidence from multiple clinical trials, nitazoxanide is considered ineffective among immunocompromised patients. (14) • Giardiasis can be asymptomatic or have a chronic course leading to malabsorption and failure to thrive. It can be treated with metronidazole, tinidazole, or nitazoxanide. On the basis of growing observational studies, postinfectious and extraintestinal manifestations of giardiasis occur, but the mechanisms are unclear. Given the high prevalence of giardiasis, public health implications need to be defined. (16) • Eradicating E histolytica from the gastrointestinal tract requires only intraluminal agent therapy. Therapy for invasive illnesses requires use of imidazole followed by intraluminal agents to eliminate persistent intraluminal parasites. • Malaria is considered the most lethal parasitic infection, with Plasmodium falciparum as the predominant cause of mortality. P vivax and P ovale can be dormant in the liver, and primaquine is necessary to resolve infection by P vivax and P ovale. • Among immunocompetent patients, infection with Toxoplasma gondii may be asymptomatic, involve localized lymphadenopathy, or cause ocular infection. In immunocompromised patients, reactivation or severe infection is not uncommon. On the basis of limited observational studies (there are no well-controlled randomized trials), therapy is recommended for acute infection during pregnancy to prevent transmission to the

  12. Biofilm formation by environmental isolates of Salmonella and their sensitivity to natural antimicrobials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated 15 Salmonella isolates; S. Derby (2), S. Infantis (4), and S. Typhimurium (9) from conventional swine farm environment (soil and lagoon) for biofilm formation. Biofilm forming ability was determined by 96-well microtitre plate Crystal-Violet and Minimum Biofilm Eradication Concentration...

  13. Nature's Migraine Treatment: Isolation and Structure Elucidation of Parthenolide from "Tanacetum parthenium"

    ERIC Educational Resources Information Center

    Walsh, Emma L.; Ashe, Siobhan; Walsh, John J.

    2012-01-01

    The purpose of this experiment is to provide students with the essential skills and knowledge required to perform the extraction, isolation, and structural elucidation of parthenolide from "Tanacetum parthenium" or feverfew. Students are introduced to a background of the traditional medicinal uses of parthenolide, while more modern applications of…

  14. DON modification in naturally-contaminated wheat samples using microorganisms isolated from the environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Fusarium graminearum produces the toxic compound deoxynivalenol (DON) that contaminates wheat, barley, and maize. New strategies are needed to mitigate DON in the United States. Microbes were isolated from different soil types, and cultured in a mineral salt media using 100 ppm DON as the...

  15. Antibiotic resistance-mediated isolation of scaffold-specific natural product producers.

    PubMed

    Thaker, Maulik N; Waglechner, Nicholas; Wright, Gerry D

    2014-01-01

    For over half a century, actinomycetes have served as the most promising source of novel antibacterial scaffolds. However, over the years, there has been a decline in the discovery of new antibiotics from actinomycetes. This is partly due to the use of standard screening methods and platforms that result in the re-discovery of the same molecules. Thus, according to current estimates, the discovery of a new antibacterial requires screening of tens to hundreds of thousands of bacterial strains. We have devised a resistance-based antibacterial discovery platform by harnessing the innate self-protection mechanism of antibiotic producers. This protocol provides a detailed method for isolation of scaffold-specific antibacterial producers by isolating strains in the presence of a selective antibiotic. As a specific example, we describe isolation of glycopeptide antibiotic (GPA) producers from soil actinomycetes, using vancomycin as the antibiotic resistance filter. However, the protocol can be adapted to isolate diverse producers from various sources producing different scaffolds, by selecting an appropriate antibiotic as a screening filter. The protocol provides a solution for two major bottlenecks that impede the new drug discovery pipeline: low hit frequency and re-discovery of known molecules. The entire protocol, from soil collection to identification of putative antibacterial producers, takes about 6 weeks to complete.

  16. Hybridization between previously isolated ancestors may explain the persistence of exactly two ancient lineages in the genome of the oyster parasite Perkinsus marinus.

    PubMed

    Thompson, Peter C; Rosenthal, Benjamin M; Hare, Matthew P

    2014-06-01

    Theory predicts that neutral genetic variation accumulates within populations to a level determined by gains through mutation and losses by genetic drift. This balance results in a characteristic distribution of allelic variation with the maximum allelic difference determined by effective population size. Here, we report a striking departure from these expectations in the form of allelic dimorphism, observed at the majority of seven loci examined in Perkinsus marinus, an important oyster parasite that causes Dermo disease. DNA sequences were collected from five loci flanking microsatellite repeats and two loci coding for superoxide dismutase enzymes that may mediate the parasite's interaction with its host. Based on 474 sequences, sampled across 5000 km of the eastern United States coastline, no more than two alleles were observed at each locus (discounting singletons). Depending on the locus, the common allele ranged in overall frequency from 72% to 92%. At each locus the two alleles differed substantially (3.8% sequence difference, on average), and the among-locus variance in divergences was not sufficient to reject a simultaneous origin for all dimorphisms using approximate Bayesian methods. Dimorphic alleles were estimated to have diverged from a common ancestral allele at least 0.9 million years ago. Across these seven loci, only five other alleles were ever observed, always as singletons and differing from the dimorphic alleles by no more than two nucleotides. Free recombination could potentially have shuffled these dimorphisms into as many as 243 multilocus combinations, but the existence of only ten combinations among all samples strongly supports low recombination frequencies and is consistent with the observed absence of intragenic recombination. We consider several demographic and evolutionary hypotheses to explain these patterns. Few can be conclusively rejected with the present data, but we advance a recent hybridization of ancient divergent lineages

  17. Testing alternative models for sexual isolation in natural populations of Littorina saxatilis: indirect support for by-product ecological speciation?

    PubMed

    Cruz, R; Carballo, M; Conde-Padín, P; Rolán-Alvarez, E

    2004-03-01

    Two ecotypes of the rough periwinkle Littorina saxatilis occur at different shore levels, showing assortative mating for size and partial reproductive isolation when they meet at the mid-shore. This system represents a putative case of incomplete speciation in sympatry. Two processes contribute to the assortative mating: morph-specific microhabitat aggregation and mate choice. The estimation of mate choice coefficients in nature and a simulation of the aggregation effects on sexual isolation were used to disentangle these processes as well as to test alternative mechanisms of mate choice. Mate choice significantly increased the frequency of within-morph pairs and significantly decreased the frequency of between-morph pairs, whereas those pairs including at least one hybrid morph mated randomly. These results allow us to reject a discriminant mate choice and support a model of evolution of sexual isolation as a side-effect of size-assortative mating in a context of divergent natural selection for size in the population. This mechanism is more compatible with a model of incomplete by-product ecological speciation, as suggested by previous evidence.

  18. Antibiotic Susceptibility Profile of Bacteria Isolated from Natural Sources of Water from Rural Areas of East Sikkim

    PubMed Central

    Poonia, Shubra; Singh, T. Shantikumar; Tsering, Dechen C.

    2014-01-01

    Background: Contamination of water, food, and environment with antibiotic-resistant bacteria poses a serious public health issue. Objective: The objective was to study the bacterial pollution of the natural sources of water in east Sikkim and to determine the antimicrobial profile of the bacterial isolates. Materials and Methods: A total of 225 samples, 75 each during winter, summer, and monsoon season were collected from the same source in every season for bacteriological analysis by membrane filtration method. Antibiotic susceptibility test was performed using standard disc diffusion method. Results: A total of 19 bacterial species of the genera Escherichia, Klebsiella, Proteus, Salmonella, Shigella, Enterobacter, Citrobacter, Morganella, Pseudomonas, Acinetobacter, Flavobacterium, and Serratia were isolated and their antimicrobial sensitivity tested. Generally, most bacterial isolates except Salmonella and Shigella species were found resistant to commonly used antibiotics such as ampicillin (57.5%), trimethoprim/sulfamethoxaole (39.1%), amoxicillin/clavulanic acid (37.4%), cefixime (34.5%), tetracycline (29.1%), ceftazidime (26.3%), ofloxacin (25.9%), amikacin (8.7%), and gentamicin (2.7%) but sensitive to imipenem and piperacillin/tazobactam. Conclusion: Natural sources of water in east Sikkim are grossly contaminated with bacteria including enteropathogens. The consumption of untreated water from these sources might pose health risk to consumers. PMID:25136156

  19. Introduced species and their missing parasites

    USGS Publications Warehouse

    Torchin, Mark E.; Lafferty, Kevin D.; Dobson, Andrew P.; McKenzie, Valerie J.; Kuris, Armand M.

    2003-01-01

    Damage caused by introduced species results from the high population densities and large body sizes that they attain in their new location. Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species. Because some parasites can reduce host density and decrease body size, an invader that leaves parasites behind and encounters few new parasites can experience a demographic release and become a pest. To test whether introduced species are less parasitized, we have compared the parasites of exotic species in their native and introduced ranges, using 26 host species of molluscs, crustaceans, fishes, birds, mammals, amphibians and reptiles. Here we report that the number of parasite species found in native populations is twice that found in exotic populations. In addition, introduced populations are less heavily parasitized (in terms of percentage infected) than are native populations. Reduced parasitization of introduced species has several causes, including reduced probability of the introduction of parasites with exotic species (or early extinction after host establishment), absence of other required hosts in the new location, and the host-specific limitations of native parasites adapting to new hosts.

  20. Isolation and molecular characterization of Leptospira borgpetersenii serovar Hardjo strain Hardjobovis in the urine of naturally infected cattle in Brazil.

    PubMed

    Chideroli, R T; Pereira, U P; Gonçalves, D D; Nakamura, A Y; Alfieri, A A; Alfieri, A F; Freitas, J C

    2016-02-19

    Most epidemiologic studies on bovine leptospirosis are based on serological tests that use antibodies against several serotypes, including the serovar Hardjo, which is widespread and considered to be the most adapted to bovine hosts. However, using only serological studies is not sufficient to identify and distinguish species of leptospires. The aim of this study was report the first isolation in Brazil of two strains serovar Hardjo obtained in urine samples from naturally infected cows in a small Brazilian dairy herd and find the genetic species and consequently the type strain Hardjobovis by molecular characterization. Fifteen dairy cows with a history of reproductive failure, such as abortion and infertility, were selected. Urine samples obtained from each animal were immediately seeded in tubes containing Ellinghausen-McCullough-Johnson-Harris culture medium. The identification of the isolates was performed by Multilocus variable-number tandem-repeat analysis (MLVA) technique and phylogenetic analysis of partial sequence of gene sec Y. From the 15 urine samples evaluated, two Leptospira were found and identified as the Londrina 49 and Londrina 54 strains. The MLVA profiles and sequencing of gene sec Y characterized the isolates as L. borgpetersenii serovar Hardjo strain Hadjobovis because it has different genetic pattern of Leptospira interrogans serovar Hardjo strain Hardjoprajitno. Therefore, more studies are needed including isolation and molecular characterization from regional strains to obtain a better knowledge about epidemiology of serovar Hardjo in bovine which may assist in future strategies of prevention and control of bovine leptospirosis.

  1. SOME ASPECTS OF THE NATURAL CONTROL OF PLANT PARASITIC NEMATODES IN SOIL UNDER BROAD BEAN VICIA FABA L. CULTIVATED IN CROP ROTATION AND LONG-TERM MONOCULTURE.

    PubMed

    Skwiercz, A T; Damszel, M; Stefanovska, T; Rychcik, B

    2015-01-01

    Observations on population density of plant parasitic nematodes occurring in rhizosphere of broad bean cultivated in the crop rotation and long-term monoculture were performed during 2013-2014. 13 species were observed: Trichodorus primitivus, T. viruliferus, Paratrichodorus pachydermus, Criconema annuliferum, Paratylenchus projectus, Bitylenchus dubius, Merlinius brevidens, Pratylenchus fallax, P. flakkensis, P. neglectus, Heterodera triffolii, H. goettingiana, and Ditylenchus dipsaci. In monoculture plots 70-80% of eggs inside Heterodera cysts were colonized by pathogenic fungi (v.s. 50-62% of cysts from crop rotation). 12-18% of specimens of Pratylenchus species were colonized by the nematode-pathogenic bacteria: Bacillus penetrans.

  2. Protozoan parasites in group-living primates: testing the biological island hypothesis.

    PubMed

    Chapman, Colin A; Bowman, Dwight D; Ghai, Ria R; Gogarten, Jan F; Goldberg, Tony L; Rothman, Jessica M; Twinomugisha, Dennis; Walsh, Chesley

    2012-06-01

    A series of articles by W.J. Freeland published in the 1970s proposed that social organization and behavioral processes were heavily influenced by parasitic infections, which led to a number of intriguing hypotheses concerning how natural selection might act on social factors because of the benefits of avoiding parasite infections. For example, Freeland [1979] showed that all individuals within a given group harbored identical gastrointestinal protozoan faunas, which led him to postulate that social groups were akin to "biological islands" and suggest how this isolation could select specific types of ranging and dispersal patterns. Here, we reexamine the biological island hypothesis by quantifying the protozoan faunas of the same primate species examined by Freeland in the same location; our results do not support this hypothesis. In contrast, we quantified two general changes in protozoan parasite community of primates in the study area of Kibale National Park, Uganda, over the nearly 35 years between sample collections: (1) the colobines found free of parasites in the early 1970s are now infected with numerous intestinal protozoan parasites and (2) groups are no longer biological islands in terms of their protozoan parasites. Whatever the ultimate explanation for these changes, our findings have implications for studies proposing selective forces shaping primate behavior and social organization.

  3. Can reduced predation offset negative effects of sea louse parasites on chum salmon?

    PubMed Central

    Peacock, Stephanie J.; Connors, Brendan M.; Krkošek, Martin; Irvine, James R.; Lewis, Mark A.

    2014-01-01

    The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host–parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations. PMID:24352951

  4. Can reduced predation offset negative effects of sea louse parasites on chum salmon?

    PubMed

    Peacock, Stephanie J; Connors, Brendan M; Krkosek, Martin; Irvine, James R; Lewis, Mark A

    2014-02-07

    The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations.

  5. Killer activity of yeasts isolated from natural environments against some medically important Candida species.

    PubMed

    Vadkertiová, Renata; Sláviková, Elena

    2007-01-01

    Twenty-five yeast cultures, mainly of human origin, belonging to four pathogenic yeast species--Candida albicans, Candida krusei, Candida parapsilosis, and Candida tropicalis were tested for their sensitivity to ten basidiomycetous and eleven ascomycetous yeast species isolated from the water and soil environments and from tree leaves. The best killer activity among basidiomycetous species was exhibited by Rhodotorula glutinis, and R. mucilaginosa. The other carotenoid producing species Cystofilobasidium capitatum, Sporobolomyces salmonicolor, and S. roseus were active only against about 40% of the tested strains and exhibited weak activity. The broadest killer activity among ascomycetous yeasts was shown by the strains Pichia anomala and Metschnikowia pulcherrima. The species Debaryomyces castellii, Debaryomyces hansenii, Hanseniaspora guilliermondii, Pichia membranifaciens, and Williopsis californica did not show any killer activity. The best killer activity exhibited the strains isolated from leafy material. The lowest activity pattern was found among strains originating from soil environment.

  6. Bioactivities, isolation and purification methods of polysaccharides from natural products: A review.

    PubMed

    Shi, Lei

    2016-11-01

    Polysaccharides play multiple roles and have extensive bioactivities in life process and an immense potential in healthcare, food and cosmetic industries, due to their therapeutic effects and relatively low toxicity. This review describes their major functions involved in antitumor, anti-virus, and anti-inflammatory bioactivities. Due to their enormous structural heterogeneity, the approaches for isolation and purification of polysaccharides are distinct from that of the other macromolecules such as proteins, etc. Yet, to achieve the homogeneity is the initial step for studies of polysaccharide structure, pharmacology, and its structure-activity relationships. According to the experiences accumulated by our lab and the published literatures, this review also introduces the methods widely used in isolation and purification of polysaccharides.

  7. Antimycobacterial activity of two natural alkaloids, vasicine acetate and 2-acetyl benzylamine, isolated from Indian shrub Adhatoda vasica Ness. leaves.

    PubMed

    Ignacimuthu, S; Shanmugam, N

    2010-12-01

    In folk medicine, Adhatoda vasica Ness. (Acanthaceae) is used to treat asthma and cough. The leaves of A. vasica were powdered and extracted with hexane, ethyl acetate and methanol. The hexane extract showed 97 percent reduction in colony-forming units (CFU) at 100 microg/ml. The hexane extract was subjected to column chromatography. Two natural compounds, vasicine acetate and 2-acetyl benzylamine, were isolated from it. They were bioassayed against Mycobacterium tuberculosis. The two compounds showed strong antimycobacterial activity. Vasicine acetate and 2-acetyl benzylamine isolated from hexane extract of A. vasica leaves, significantly inhibited M. tuberculosis and one multi-drug-resistant (MDR) strain and one sensitive strain at 200 and 50 microg/ml, respectively. Our study demonstrated that both the compounds, vasicine acetate and 2-acetyl benzylamine, could be evaluated further for developing a drug to control M. tuberculosis.

  8. Comparing mechanisms of host manipulation across host and parasite taxa

    USGS Publications Warehouse

    Lafferty, Kevin D.; Shaw, Jenny C.

    2013-01-01

    Parasites affect host behavior in several ways. They can alter activity, microhabitats or both. For trophically transmitted parasites (the focus of our study), decreased activity might impair the ability of hosts to respond to final-host predators, and increased activity and altered microhabitat choice might increase contact rates between hosts and final-host predators. In an analysis of trophically transmitted parasites, more parasite groups altered activity than altered microhabitat choice. Parasites that infected vertebrates were more likely to impair the host’s reaction to predators, whereas parasites that infected invertebrates were more likely to increase the host’s contact with predators. The site of infection might affect how parasites manipulate their hosts. For instance, parasites in the central nervous system seem particularly suited to manipulating host behavior. Manipulative parasites commonly occupy the body cavity, muscles and central nervous systems of their hosts. Acanthocephalans in the data set differed from other taxa in that they occurred exclusively in the body cavity of invertebrates. In addition, they were more likely to alter microhabitat choice than activity. Parasites in the body cavity (across parasite types) were more likely to be associated with increased host contact with predators. Parasites can manipulate the host through energetic drain, but most parasites use more sophisticated means. For instance, parasites target four physiological systems that shape behavior in both invertebrates and vertebrates: neural, endocrine, neuromodulatory and immunomodulatory. The interconnections between these systems make it difficult to isolate specific mechanisms of host behavioral manipulation.

  9. Genetic characterization of highly pathogenic avian influenza H5N1 viruses isolated from naturally infected pigeons in Egypt.

    PubMed

    Elgendy, Emad Mohamed; Watanabe, Yohei; Daidoji, Tomo; Arai, Yasuha; Ikuta, Kazuyoshi; Ibrahim, Madiha Salah; Nakaya, Takaaki

    2016-12-01

    Avian influenza viruses impose serious public health burdens with significant mortality and morbidity not only in poultry but also in humans. While poultry susceptibility to avian influenza virus infection is well characterized, pigeons have been thought to have low susceptibility to these viruses. However, recent studies reported natural pigeon infections with highly pathogenic avian influenza H5N1 viruses. In Egypt, which is one of the H5N1 endemic areas for birds, pigeons are raised in towers built on farms in backyards and on house roofs, providing a potential risk for virus transmission from pigeons to humans. In this study, we performed genetic analysis of two H5N1 virus strains that were isolated from naturally infected pigeons in Egypt. Genetic and phylogenetic analyses showed that these viruses originated from Egyptian H5N1 viruses that were circulating in chickens or ducks. Several unique mutations, not reported before in any Egyptian isolates, were detected in the internal genes (i.e., polymerase residues PB1-V3D, PB1-K363R, PA-A369V, and PA-V602I; nucleoprotein residue NP-R38K; and nonstructural protein residues NS1-D120N and NS2-F55C). Our findings suggested that pigeons are naturally infected with H5N1 virus and can be a potential reservoir for transmission to humans, and showed the importance of genetic analysis of H5N1 internal genes.

  10. Characterization of Antifungal Natural Products Isolated from Endophytic Fungi of Finger Millet (Eleusine coracana).

    PubMed

    Mousa, Walaa Kamel; Schwan, Adrian L; Raizada, Manish N

    2016-09-03

    Finger millet is an ancient African-Indian crop that is resistant to many pathogens including the fungus, Fusarium graminearum. We previously reported the first isolation of putative fungal endophytes from finger millet and showed that the crude extracts of four strains had anti-Fusarium activity. However, active compounds were isolated from only one strain. The objectives of this study were to confirm the endophytic lifestyle of the three remaining anti-Fusarium isolates, to identify the major underlying antifungal compounds, and to initially characterize the mode(s) of action of each compound. Results of confocal microscopy and a plant disease assay were consistent with the three fungal strains behaving as endophytes. Using bio-assay guided fractionation and spectroscopic structural elucidation, three anti-Fusarium secondary metabolites were purified and characterized. These molecules were not previously reported to derive from fungi nor have antifungal activity. The purified antifungal compounds were: 5-hydroxy 2(3H)-benzofuranone, dehydrocostus lactone (guaianolide sesquiterpene lactone), and harpagoside (an iridoide glycoside). Light microscopy and vitality staining were used to visualize the in vitro interactions between each compound and Fusarium; the results suggested a mixed fungicidal/fungistatic mode of action. We conclude that finger millet possesses fungal endophytes that can synthesize anti-fungal compounds not previously reported as bio-fungicides against F. graminearum.

  11. Phylogenetic characterization of canine distemper virus isolates from naturally infected dogs and a marten in Korea.

    PubMed

    An, Dong-Jun; Yoon, Sook-Hee; Park, Jee-Yong; No, In-Sun; Park, Bong-Kyun

    2008-12-10

    We sequenced the hemagglutinin (H) genes from four canine distemper virus (CDV) isolates obtained from three dogs and a marten in Korea. These sequences were included in subsequent H gene-focused phylogenetic tree analysis of 89 CDV strains. This analysis revealed eight clades designated as EU1, EU2, EU3, NA1, NA2, Asia 1, Asia 2 and Vaccine. Three of the Korean isolates (97Jindo, 98Marten and 07D111) occurred in the Asia 2 group that also contains many Japanese CDV strains isolated in 1998. The remaining Korean strain (07Q72) fell into the Asia 1 group. The 21 H protein sequences of 25 Asia 1 strains are generally predicted to bear nine potential N-linked glycosylation sites. In contrast, the 9 H protein sequences of 12 Asia 2 strains had eight potential N-linked glycosylation sites. The remaining strains had six (98Marten and 07D111) and seven (97Jindo) potential N-linked glycosylation sites.

  12. In vitro activities of natural products against oral Candida isolates from denture wearers

    PubMed Central

    2011-01-01

    Background Candida-associated denture stomatitis is a frequent infectious disease. Treatment of this oral condition is difficult because failures and recurrences are common. The aim of this study was to test the in vitro antifungal activity of pure constituents of essentials oils. Methods Eight terpenic derivatives (carvacrol, farnesol, geraniol, linalool, menthol, menthone, terpinen-4-ol, and α-terpineol), a phenylpropanoid (eugenol), a phenethyl alcohol (tyrosol) and fluconazole were evaluated against 38 Candida isolated from denture-wearers and 10 collection Candida strains by the CLSI M27-A3 broth microdilution method. Results Almost all the tested compounds showed antifungal activity with MIC ranges of 0.03-0.25% for eugenol and linalool, 0.03-0.12% for geraniol, 0.06-0.5% for menthol, α-terpineol and terpinen-4-ol, 0.03-0.5% for carvacrol, and 0.06-4% for menthone. These compounds, with the exception of farnesol, menthone and tyrosol, showed important in vitro activities against the fluconazole-resistant and susceptible-dose dependent Candida isolates. Conclusions Carvacrol, eugenol, geraniol, linalool and terpinen-4-ol were very active in vitro against oral Candida isolates. Their fungistatic and fungicidal activities might convert them into promising alternatives for the topic treatment of oral candidiasis and denture stomatitis. PMID:22118215

  13. Genetically distinct isolates of Spirocerca sp. from a naturally infected red fox (Vulpes vulpes) from Denmark.

    PubMed

    Al-Sabi, Mohammad Nafi Solaiman; Hansen, Mette Sif; Chriél, Mariann; Holm, Elisabeth; Larsen, Gitte; Enemark, Heidi Larsen

    2014-09-15

    Spirocerca lupi causes formation of nodules that may transform into sarcoma in the walls of aorta, esophagus and stomach of infected canids. In February 2013, post mortem examination of a red fox (Vulpes vulpes) hunted in Denmark revealed the presence of several nodules containing adult worms of Spirocerca sp. in the stomach and the omentum. The nodules largely consisted of fibrous tissue with infiltration of mononuclear cells, neutrophilic granulocytes and macrophages with hemosiderin deposition. Parasitological examination by three copromicroscopic methods, sedimentation, flotation with saturated sugar-salt solution, and sieving failed to detect eggs of Spirocerca sp. in feces collected from the colon. This is the first report of spirocercosis in Denmark, and may have been caused by a recent introduction by migrating paratenic or definitive host. Analysis of two overlapping partial sequences of the cox1 gene, from individual worms, revealed distinct genetic variation (7-9%) between the Danish worms and isolates of S. lupi from Europe, Asia and Africa. This was confirmed by phylogenetic analysis that clearly separated the Danish worms from other isolates of S. lupi. The distinct genetic differences of the current worms compared to other isolates of S. lupi may suggest the presence of a cryptic species within Spirocerca.

  14. Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus

    NASA Astrophysics Data System (ADS)

    Knolhoff, Ann M.; Zheng, Jie; McFarland, Melinda A.; Luo, Yan; Callahan, John H.; Brown, Eric W.; Croley, Timothy R.

    2015-08-01

    The rise of antimicrobial resistance necessitates the discovery and/or production of novel antibiotics. Isolated strains of Paenibacillus alvei were previously shown to exhibit antimicrobial activity against a number of pathogens, such as E. coli, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA). The responsible antimicrobial compounds were isolated from these Paenibacillus strains and a combination of low and high resolution mass spectrometry with multiple-stage tandem mass spectrometry was used for identification. A group of closely related cyclic lipopeptides was identified, differing primarily by fatty acid chain length and one of two possible amino acid substitutions. Variation in the fatty acid length resulted in mass differences of 14 Da and yielded groups of related MSn spectra. Despite the inherent complexity of MS/MS spectra of cyclic compounds, straightforward analysis of these spectra was accomplished by determining differences in complementary product ion series between compounds that differ in molecular weight by 14 Da. The primary peptide sequence assignment was confirmed through genome mining; the combination of these analytical tools represents a workflow that can be used for the identification of complex antibiotics. The compounds also share amino acid sequence similarity to a previously identified broad-spectrum antibiotic isolated from Paenibacillus. The presence of such a wide distribution of related compounds produced by the same organism represents a novel class of broad-spectrum antibiotic compounds.

  15. Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus.

    PubMed

    Knolhoff, Ann M; Zheng, Jie; McFarland, Melinda A; Luo, Yan; Callahan, John H; Brown, Eric W; Croley, Timothy R

    2015-10-01

    The rise of antimicrobial resistance necessitates the discovery and/or production of novel antibiotics. Isolated strains of Paenibacillus alvei were previously shown to exhibit antimicrobial activity against a number of pathogens, such as E. coli, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA). The responsible antimicrobial compounds were isolated from these Paenibacillus strains and a combination of low and high resolution mass spectrometry with multiple-stage tandem mass spectrometry was used for identification. A group of closely related cyclic lipopeptides was identified, differing primarily by fatty acid chain length and one of two possible amino acid substitutions. Variation in the fatty acid length resulted in mass differences of 14 Da and yielded groups of related MS(n) spectra. Despite the inherent complexity of MS/MS spectra of cyclic compounds, straightforward analysis of these spectra was accomplished by determining differences in complementary product ion series between compounds that differ in molecular weight by 14 Da. The primary peptide sequence assignment was confirmed through genome mining; the combination of these analytical tools represents a workflow that can be used for the identification of complex antibiotics. The compounds also share amino acid sequence similarity to a previously identified broad-spectrum antibiotic isolated from Paenibacillus. The presence of such a wide distribution of related compounds produced by the same organism represents a novel class of broad-spectrum antibiotic compounds.

  16. Performance of sand and shredded rubber tire mixture as a natural base isolator for earthquake protection

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Srijit; Sengupta, Aniruddha; Reddy, G. R.

    2015-12-01

    The performance of a well-designed layer of sand, and composites like layer of sand mixed with shredded rubber tire (RSM) as low cost base isolators, is studied in shake table tests in the laboratory. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The block is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the block and the sand foundation. Accelerometers are placed on top of the footing and foundation sand layer. The displacement of the footing is also measured by LVDT. The whole setup is mounted on a shake table and subjected to sinusoidal motions with varying amplitude and frequency. Sand is found to be effective only at very high amplitude (> 0.65 g) of motions. The performance of a composite consisting of sand and 50% shredded rubber tire placed under the footing is found to be most promising as a low-cost effective base isolator.

  17. Isolation of Ehrlichia chaffeensis from wild white-tailed deer (Odocoileus virginianus) confirms their role as natural reservoir hosts.

    PubMed

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Howerth, E W

    1997-07-01

    Field and experimental studies have implicated white-tailed deer (Odocoileus virginianus) as probable reservoir hosts for Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of E. chaffeensis. Thirty-five white-tailed deer collected from three Amblyomma americanum-infested populations in Georgia were examined for evidence of E. chaffeensis infection by serologic, molecular, cell culture, and xenodiagnostic methods. Twenty-seven deer (77%) had E. chaffeensis-reactive indirect fluorescent-antibody assay titers of > or = 1:64; and the blood, spleens, or lymph nodes of seven (20%) deer were positive in a nested PCR assay with E. chaffeensis-specific primers. E. chaffeensis was isolated in DH82 cell cultures from the blood of five (14%) deer, including two deer that were PCR negative. Combination of culture and PCR results indicated that six (17%) deer were probably rickettsemic and that nine (26%) were probably infected. Restriction digestion of PCR products amplified from deer tissues and cell culture isolates resulted in a banding pattern consistent with the E. chaffeensis 16S rRNA gene sequence. The sequences of all PCR products from deer tissues or cell culture isolates were identical to the sequence of the Arkansas type strain of E. chaffeensis. Xenodiagnosis with C3H mice inoculated intraperitoneally with deer blood, spleen, or lymph node suspensions was unsuccessful. When viewed in the context of previous studies, these findings provide strong evidence that E. chaffeensis is maintained in nature primarily by a tick vector-vertebrate reservoir system consisting of lone star ticks and white-tailed deer.

  18. Assessment of Domestic Goats as Models for Experimental and Natural Infection with the North American Isolate of Rickettsia slovaca

    PubMed Central

    Keating, M. Kelly; Spivey, Pamela; Lathrop, George W.; Powell, Nathaniel; Levin, Michael L.

    2016-01-01

    Rickettsia slovaca is a tick-borne human pathogen that is associated with scalp eschars and neck lymphadenopathy known as tick-borne lymphadenopathy (TIBOLA) or Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). Originally, R. slovaca was described in Eastern Europe, but since recognition of its pathogenicity, human cases have been reported throughout Europe. European vertebrate reservoirs of R. slovaca remain unknown, but feral swine and domestic goats have been found infected or seropositive for this pathogen. Recently, a rickettsial pathogen identical to R. slovaca was identified in, and isolated from, the American dog tick, Dermacentor variabilis. In previous experimental studies, this organism was found infectious to guinea pigs and transovarially transmissible in ticks. In this study, domestic goats (Capra hircus) were experimentally inoculated with the North American isolate of this R. slovaca-like agent to assess their reservoir competence–the ability to acquire the pathogens and maintain transmission between infected and uninfected ticks. Goats were susceptible to infection as demonstrated by detection of the pathogen in skin biopsies and multiple internal tissues, but the only clinical sign of illness was transient fever noted in three out of four goats, and reactive lymphoid hyperplasia. On average, less than 5% of uninfected ticks acquired the pathogen while feeding upon infected goats. Although domestic goats are susceptible to the newly described North American isolate of R. slovaca, they are likely to play a minor role in the natural transmission cycle of this pathogen. Our results suggest that goats do not propagate the North American isolate of R. slovaca in peridomestic environments and clinical diagnosis of infection could be difficult due to the brevity and mildness of clinical signs. Further research is needed to elucidate the natural transmission cycle of R. slovaca both in Europe and North America, as well as to identify a

  19. Ecological consequences of manipulative parasites: chapter 9

    USGS Publications Warehouse

    Lafferty, Kevin D.; Kuris, A. M.

    2012-01-01

    phrases such as “may ultimately infl uence community structure” (Kiesecker and Blaustein 1999), yet few demonstrate ecological effects. Here, we consider the conditions under which manipulative parasites might have a substantial ecological effect in nature and highlight those for which evidence exists (see also Chapter 10).

  20. A new model for myxosporean (Myxozoa) development explains the endogenous budding phenomenon, the nature of cell within cell life stages and evolution of parasitism from a cnidarian ancestor.

    PubMed

    Morris, D J

    2012-08-01

    The phylum Myxozoa is composed of endoparasitic species that have predominately been recorded within aquatic vertebrates. The simple body form of a trophic cell containing other cells within it, as observed within these hosts, has provided few clues to relationships with other organisms. In addition, the placement of the group using molecular phylogenies has proved very difficult, although the majority of analyses now suggest that they are cnidarians. There have been relatively few studies of myxozoan stages within invertebrate hosts, even though these exhibit multicellular and sexual stages that may provide clues to myxozoan evolution. Therefore an ultrastructural examination of a myxozoan infection of a freshwater oligochaete was conducted, to reassess and formulate a model for myxozoan development in these hosts. This deemed that meiosis occurs within the oligochaete, but that fertilisation is not immediate. Rather, the resultant haploid germ cell (oocyte) is engulfed by a diploid sporogonic cell (nurse cell) to form a sporoplasm. It is this sporoplasm that infects the fish, resulting in the multicellular stages observed. Fertilisation occurs after the parasites leave the fish and enter the oligochaete host. The nurse cell/oocyte model explains previously conflicting evidence in the literature regarding myxosporean biology, and aligns phenomena considered distinctive to the Myxozoa, such as endogenous budding and cell within cell development, with processes recorded in cnidarians. Finally, the evolutionary origin of the Myxozoa as cnidarian parasites of ova is hypothesised.

  1. Pre-adapting parasitic phages to a pathogen leads to increased pathogen clearance and lowered resistance evolution with Pseudomonas aeruginosa cystic fibrosis bacterial isolates.

    PubMed

    Friman, V-P; Soanes-Brown, D; Sierocinski, P; Molin, S; Johansen, H K; Merabishvili, M; Pirnay, J-P; De Vos, D; Buckling, A

    2016-01-01

    Recent years have seen renewed interest in phage therapy--the use of viruses to specifically kill disease-causing bacteria--because of the alarming rise in antibiotic resistance. However, a major limitation of phage therapy is the ease at with bacteria can evolve resistance to phages. Here, we determined whether in vitro experimental coevolution can increase the efficiency of phage therapy by limiting the resistance evolution of intermittent and chronic cystic fibrosis Pseudomonas aeruginosa lung isolates to four different phages. We first pre-adapted all phage strains against all bacterial strains and then compared the efficacy of pre-adapted and nonadapted phages against ancestral bacterial strains. We found that evolved phages were more efficient in reducing bacterial densities than ancestral phages. This was primarily because only 50% of bacterial strains were able to evolve resistance to evolved phages, whereas all bacteria were able to evolve some level of resistance to ancestral phages. Although the rate of resistance evolution did not differ between intermittent and chronic isolates, it incurred a relatively higher growth cost for chronic isolates when measured in the absence of phages. This is likely to explain why evolved phages were more effective in reducing the densities of chronic isolates. Our data show that pathogen genotypes respond differently to phage pre-adaptation, and as a result, phage therapies might need to be individually adjusted for different patients.

  2. Isolation and RFLP genotyping of toxoplasma gondii in free-range chicken(Gallus domesticus) in Grenada, West Indies, revealed widespread and dominance of clonal type III parasites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of the present cross sectional study were to estimate the prevalence and to isolate and genotype Toxoplasma gondii in free range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with ...

  3. Genetic architecture of a reinforced, postmating, reproductive isolation barrier between Neurospora species indicates evolution via natural selection.

    PubMed

    Turner, Elizabeth; Jacobson, David J; Taylor, John W

    2011-08-01

    A role for natural selection in reinforcing premating barriers is recognized, but selection for reinforcement of postmating barriers remains controversial. Organisms lacking evolvable premating barriers can theoretically reinforce postmating isolation, but only under restrictive conditions: parental investment in hybrid progeny must inhibit subsequent reproduction, and selected postmating barriers must restore parents' capacity to reproduce successfully. We show that reinforced postmating isolation markedly increases maternal fitness in the fungus Neurospora crassa, and we detect the evolutionary genetic signature of natural selection by quantitative trait locus (QTL) analysis of the reinforced barrier. Hybrid progeny of N. crassa and N. intermedia are highly inviable. Fertilization by local N. intermedia results in early abortion of hybrid fruitbodies, and we show that abortion is adaptive because only aborted maternal colonies remain fully receptive to future reproduction. In the first QTL analysis of postmating reinforcement in microbial eukaryotes, we identify 11 loci for abortive hybrid fruitbody development, including three major QTLs that together explain 30% of trait variance. One of the major QTLs and six QTLs of lesser effect are found on the mating-type determining chromosome of Neurospora. Several reinforcement QTLs are flanked by genetic markers showing either segregation distortion or non-random associations with alleles at other loci in a cross between N. crassa of different clades, suggesting that the loci also are associated with local effects on same-species reproduction. Statistical analysis of the allelic effects distribution for abortive hybrid fruitbody development indicates its evolution occurred under positive selection. Our results strongly support a role for natural selection in the evolution of reinforced postmating isolation in N. crassa.

  4. Isolation of Legionella species from Noyu (unattended natural hot springs in mountains and fields) samples in Japan.

    PubMed

    Furuhata, Katsunori; Edagawa, Akiko; Ishizaki, Naoto; Fukuyama, Masafumi

    2013-01-01

    In order to understand the habitation conditions of the bacteria of the genus Legionella in Noyu (unattended natural hot springs in mountains and fields) in Japan, isolation of Legionella spp. was attempted in the Noyu samples from 11 prefectures nationwide between May and September 2012, and the following results were obtained. Overall, Legionella spp. was isolated from 16 of 43 samples (37.2%). The species was isolated from the Hokkaido region to the Chugoku region but not from the Shikoku region to the Kyushu region. The number of bacteria detected was usually small, less than 5.0 × 10(1) CFU/100 ml, as found in 11 samples (68.8%), while counts of 10(2) or more to 10(3) or less CFU/100 ml were found in two samples (12.5%). Legionella pneumophila was the most commonly found strain, with 19 strains (90.5%) found, and was the dominant species. Regarding the serogrouping, four strains (21.1%) fell under group 1, the most common grouping, followed by three strains (15.8%) in group 3, two strains (10.5%) in group 5, etc. Moreover, the detected bacterial strains other than L. pneumophila included two strains (9.5%) of L. londiniensis. The temperature of the Noyu from which Legionella spp. was isolated was between 33.1°C and 41.5°C with a pH ranging from 5.2 to 8.1. The present report is the first report to clarify the habitation conditions of strains of Legionella spp. isolated from Noyu in Japan.

  5. Association between host's genetic diversity and parasite burden in damselflies.

    PubMed

    Kaunisto, K M; Viitaniemi, H M; Leder, E H; Suhonen, J

    2013-08-01

    Recent research indicates that low genetic variation in individuals can increase susceptibility to parasite infection, yet evidence from natural invertebrate populations remains scarce. Here, we studied the relationship between genetic heterozygosity, measured as AFLP-based inbreeding coefficient fAFLP , and gregarine parasite burden from eleven damselfly, Calopteryx splendens, populations. We found that in the studied populations, 5-92% of males were parasitized by endoparasitic gregarines (Apicomplexa: Actinocephalidae). Number of parasites ranged from none to 47 parasites per male, and parasites were highly aggregated in a few hosts. Mean individual fAFLP did not differ between populations. Moreover, we found a positive association between individual's inbreeding coefficient and parasite burden. In other words, the more homozygous the individual, the more parasites it harbours. Thus, parasites are likely to pose strong selection pressure against inbreeding and homozygosity. Our results support the heterozygosity-fitness correlation hypothesis, which suggests the importance of heterozygosity for an individual's pathogen resistance.

  6. Can host ecology and kin selection predict parasite virulence?

    PubMed

    Gleichsner, Alyssa M; Minchella, Dennis J

    2014-07-01

    Parasite virulence, or the damage a parasite does to its host, is measured in terms of both host costs (reductions in host growth, reproduction and survival) and parasite benefits (increased transmission and parasite numbers) in the literature. Much work has shown that ecological and genetic factors can be strong selective forces in virulence evolution. This review uses kin selection theory to explore how variations in host ecological parameters impact the genetic relatedness of parasite populations and thus virulence. We provide a broad overview of virulence and population genetics studies and then draw connections to existing knowledge about natural parasite populations. The impact of host movement (transporting parasites) and host resistance (filtering parasites) on the genetic structure and virulence of parasite populations is explored, and empirical studies of these factors using Plasmodium and trematode systems are proposed.

  7. A Natural Electromagnetic Fields Effect on Healthy Volunteers During Long-Term Experiment with Isolation

    NASA Astrophysics Data System (ADS)

    Gurfinkel, Yury I.; Mikhailov, Valery M.; Ushakov, Boris B.

    2008-06-01

    There were investigated four healthy volunteers at the age of 37, 40, 41 and 48 during the baseline 240-d isolation period starting from July 3, 1999 in the frame of SFINCSS-99 - "SIMULATION OF FLIGHT OF INTERNATIONAL CREW ON SPACE STATION". Before a starting of experiment with long-term isolation were carried out measurements of magnetic properties of module and sleeping places. With the regularity of 3 times a week each subject made records of no less then 3 video episodes with the total length of one minute minimum at the same time between 1 and 2 p.m. Applying vital non-invasive computer capillaroscopy of nailbed has allowed quantitatively estimating a capillary blood velocity (CBV). The microcirculation parameters obtained during experiment were compared to local indexes of geomagnetic activity. About 1500 episodes were recorded on laser disks and analyzed. Parameters of microcirculation were compared with other physiological parameters monitored in the experiment. CBV investigation during the most intensive magnetic storm for the period of isolation (A-index- 44) show, that CBV at all volunteers was considerably slowed down. The greatest delay of blood flow velocity revealed at the subject which the factor of shielding of a constant magnetic field at the level of the sleeping berth has made 2,0. CBV at the subject has made 498 ± 46 μm/s with (- 65,8 % from base line). Least delay of a CBV is revealed at the subject which the factor of shielding of a constant magnetic field at the level of the sleeping berth has made 3, 15 (-12 % from base line).

  8. Is the FAMACHA chart suitable for every breed? Correlations between FAMACHA scores and different traits of mucosa colour in naturally parasite infected sheep breeds.

    PubMed

    Moors, Eva; Gauly, Matthias

    2009-12-03

    Infections with gastrointestinal nematodes, in particular Haemonchus contortus, are worldwide one of the most important factors causing high economic losses in sheep production. Different methods for detecting infections with H. contortus have been described, such as, e.g. the FAMACHA system, which categorises the colour of the conjunctivae from red to pale. When H. contortus is not the predominant parasite, the FAMACHA chart might not be suitable to detect nematode infections, because of the lack of a blood feeding parasite. Otherwise breed-specific differences in the colour of the mucosa could be responsible for the limitations of the FAMACHA system. The aim of the study was to compare different methods of measuring mucosa colour in the German sheep breeds Black Head Mutton (BH) and Leine sheep (LE). In a total of 232 6-months-old lambs, the colour of mucosa was measured using the FAMACHA chart (conjunctivae) as well as the colour analyser Minolta Chroma Meter CR-200b (gingivae). Faeces and blood samples were taken at the same time to determine faecal egg counts per gram faeces (FEC) and the packed cell volume (PCV), respectively. Lambs grazed on contaminated pastures and no anthelmintic treatment was used. Lambs were moderately infected with gastrointestinal nematodes with no significant difference between the two breeds (P>0.05). The prevalence of H. contortus was 23%, based on larvae differentiation of coproculture. There was no significant correlation between FEC and PCV, nor FEC and FAMACHA (P>0.05). Significant differences (P<0.05) were found between the BH and LE lambs with regard to the colour measurement traits Chroma, hue-angle and FAMACHA. Beside the relatively low parasite pressure, these differences in the mucosa colour between the two breeds could be responsible for the limitations of the FAMACHA chart as a useful indicator of a nematode infection. Measuring the colour of the mucosa by using a colour analyser seems to be more suitable to detect less

  9. Genetic and Pathological Follow-Up Study of Goats Experimentally and Naturally Exposed to a Sheep Scrapie Isolate

    PubMed Central

    Maestrale, Caterina; Cancedda, Maria G.; Pintus, Davide; Masia, Mariangela; Nonno, Romolo; Ru, Giuseppe; Carta, Antonello; Demontis, Francesca; Santucciu, Cinzia

    2015-01-01

    ABSTRACT Thirty-seven goats carrying different prion protein genotypes (PRNP) were orally infected with a classical scrapie brain homogenate from wild-type (ARQ/ARQ) sheep and then mated to obtain 2 additional generations of offspring, which were kept in the same environment and allowed to be naturally exposed to scrapie. Occurrence of clinical or subclinical scrapie was observed in the experimentally infected goats (F0) and in only one (F1b) of the naturally exposed offspring groups. In both groups (F0 and F1b), goats carrying the R154H, H154H, R211Q, and P168Q-P240P dimorphisms died of scrapie after a longer incubation period than wild-type, G37V, Q168Q-P240P, and S240P goats. In contrast, D145D and Q222K goats were resistant to infection. The immunobiochemical signature of the scrapie isolate and its pathological aspects observed in the sheep donors were substantially maintained over 2 goat generations, i.e., after experimental and natural transmission. This demonstrates that the prion protein gene sequence, which is shared by sheep and goats, is more powerful than any possible but unknown species-related factors in determining scrapie phenotypes. With regard to genetics, our study confirms that the K222 mutation protects goats even against ovine scrapie isolates, and for the first time, a possible association of D145 mutation with scrapie resistance is shown. In addition, it is possible that the sole diverse frequencies of these genetic variants might, at least in part, shape the prevalence of scrapie among naturally exposed progenies in affected herds. IMPORTANCE This study was aimed at investigating the genetic and pathological features characterizing sheep-to-goat transmission of scrapie. We show that in goats with different prion protein gene mutations, the K222 genetic variant is associated with scrapie resistance after natural and experimental exposure to ovine prion infectivity. In addition, we observed for the first time a protective effect of the D145

  10. Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters

    EPA Science Inventory

    This study was undertaken to solve the problem of removal of sulfate and silica from solutions of natural organic matter (NOM) that have been pre-concentrated by reverse osmosis. The goal is the development of a method by which NOM can be concentrated and desalted to obtain a low...

  11. A comparison of gel diffusion, fluorescent antibody and virus isolation methods in experimental and natural cases of infectious bursal disease.

    PubMed Central

    Ide, P R

    1975-01-01

    In studies with chicks inoculated with the Sk-1 strain of infectious bursal agent the bursa of Fabricius was found to be the tissue of choice for virus isolation as well as for use in the fluorescent antibody test and the agar gel diffusion test. In separate experiments positive results were obtained until postinoculation days 3 or 4 by the agar gel diffusion test, 5 or 6 by the fluorescent antibody test and 14 by the virus isolation method, respectively. Bursas from chickens involved in seven natural outbreaks of infectious bursal disease were then examined by these three methods. Virus was isolated from six outbreaks and infectious bursal agent antigen was demonstrated in three by the agar gel diffusion test method and seven (three by direct examination and four after one passage in chicks) by the fluorescent antibody test method. Passage in chicks was required when nonspecific fluorescence complicated the interpretation of fluorescent antibody test results. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:164991

  12. Biodiversity among Lactobacillus helveticus Strains Isolated from Different Natural Whey Starter Cultures as Revealed by Classification Trees

    PubMed Central

    Gatti, Monica; Trivisano, Carlo; Fabrizi, Enrico; Neviani, Erasmo; Gardini, Fausto

    2004-01-01

    Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium used extensively for manufacturing Swiss type and aged Italian cheese. In this study, the phenotypic and genotypic diversity of strains isolated from different natural dairy starter cultures used for Grana Padano, Parmigiano Reggiano, and Provolone cheeses was investigated by a classification tree technique. A data set was used that consists of 119 L. helveticus strains, each of which was studied for its physiological characters, as well as surface protein profiles and hybridization with a species-specific DNA probe. The methodology employed in this work allowed the strains to be grouped into terminal nodes without difficult and subjective interpretation. In particular, good discrimination was obtained between L. helveticus strains isolated, respectively, from Grana Padano and from Provolone natural whey starter cultures. The method used in this work allowed identification of the main characteristics that permit discrimination of biotypes. In order to understand what kind of genes could code for phenotypes of technological relevance, evidence that specific DNA sequences are present only in particular biotypes may be of great interest. PMID:14711641

  13. Isolation and identification of Acanthamoeba species from natural water sources in the northeastern part of Thailand.

    PubMed

    Thammaratana, Thani; Laummaunwai, Porntip; Boonmars, Thidarut

    2016-04-01

    Acanthamoeba are found in the environment, particularly in water, all over the world. The genus is currently classified into 20 different genotypes, T1-T20. In this study, 63 natural water samples from 11 provinces in northeast Thailand were collected and cultured on non-nutrient agar plates. Positive samples by culture were subsequently analyzed by molecular methods. The identification of Acanthamoeba was based on morphological features and molecular techniques using PCR and DNA sequencing. The results showed that 10 samples out of 63 were positive (15.9 %). Phylogenetic analysis revealed that seven samples were T4, one sample was similar to T3, and the other two samples were similar to T5. This is the first report demonstrating the contamination of Acanthamoeba species in natural water sources in northeast Thailand.

  14. Direct ethanol production from starch using a natural isolate, Scheffersomyces shehatae: Toward consolidated bioprocessing.

    PubMed

    Tanimura, Ayumi; Kikukawa, Minako; Yamaguchi, Shino; Kishino, Shigenobu; Ogawa, Jun; Shima, Jun

    2015-04-22

    Consolidated bioprocessing (CBP), which integrates enzyme production, saccharification and fermentation into a one-step process, is a promising strategy for cost-effective ethanol production from starchy biomass. To gain insights into starch-based ethanol production using CBP, an extensive screening was undertaken to identify naturally occurring yeasts that produce ethanol without the addition of any amylases. Three yeast strains were capable of producing a significant amount of ethanol. Quantitative assays revealed that Scheffersomyces shehatae JCM 18690 was the strain showing the highest ethanol production ability. This strain was able to utilize starch directly, and the ethanol concentration reached 9.21 g/L. We attribute the ethanol-producing ability of this strain to the high levels of glucoamylase activity, fermentation potential and ethanol stress tolerance. This study strongly suggests the possibility of starch-based ethanol production by consolidated bioprocessing using natural yeasts such as S. shehatae JCM 18690.

  15. The Interplay of Host Microbiota and Parasitic Protozoans at Mucosal Interfaces: Implications for the Outcomes of Infections and Diseases.

    PubMed

    Bär, Ann-Katrein; Phukan, Niha; Pinheiro, Jully; Simoes-Barbosa, Augusto

    2015-12-01

    Infections by parasitic protozoans are largely neglected, despite threatening millions of people, particularly in developing countries. With descriptions of the microbiota in humans, a new frontier of investigation is developing to decipher the complexity of host-parasite-microbiota relationships, instead of the classic reductionist approach, which considers host-parasite in isolation. Here, we review with specific examples the potential roles that the resident microbiota can play at mucosal interfaces in the transmission of parasitic protozoans and in the progress of infection and disease. Although the mechanisms underlying these relationships remain poorly understood, some examples provide compelling evidence that specific components of the microbiota can potentially alter the outcomes of parasitic infections and diseases in humans. Most findings suggest a protective role of the microbiota, which might lead to exploratory research comprising microbiota-based interventions to prevent and treat protozoal infections in the future. However, these infections are often accompanied by an unbalanced microbiota and, in some specific cases, apparently, these bacteria may contribute synergistically to disease progression. Taken together, these findings provide a different perspective on the ecological nature of protozoal infections. This review focuses attention on the importance of considering polymicrobial associations, i.e., parasitic protozoans and the host microbiota, for understanding these human infections in their natural microbial context.

  16. Isolation and characterization of microsatellite loci for Bixa orellana, an important source of natural dyes.

    PubMed

    Dequigiovanni, G; Ramos, S L F; Zucchi, M I; Bajay, M M; Pinheiro, J B; Fabri, E G; Bressan, E A; Veasey, E A

    2014-10-31

    Annatto (Bixa orellana) is a plant native from the American continental tropical zone. The seeds are used to produce a carotenoid-based yellow to orange food coloring. Microsatellite markers were developed for the Brazilian native species Bixa orellana to describe its genetic diversity and structure as well as to support conservation studies. Twenty-five microsatellite loci were isolated and characterized using an enriched genomic library. Ten loci were polymorphic in the 50 accessions sampled in this study, while 15 were considered monomorphic. The mean number of alleles per locus was 3.8, ranging from 2 to 6 alleles per locus. Mean values for the observed and expected heterozygosities were 0.541 (ranging from 0 to 0.658) and 0.639 (ranging from 0.422 to 0.787), respectively. All markers described in this study will be useful in further studies evaluating the genetic diversity, population dynamics, and conservation genetics of Bixa orellana.

  17. New evidence on the colour and nature of the isolated Archaeopteryx feather.

    PubMed

    Carney, Ryan M; Vinther, Jakob; Shawkey, Matthew D; D'Alba, Liliana; Ackermann, Jörg

    2012-01-24

    Archaeopteryx has been regarded as an icon of evolution ever since its discovery from the Late Jurassic limestone deposits of Solnhofen, Germany in 1861. Here we report the first evidence of colour from Archaeopteryx based on fossilized colour-imparting melanosomes discovered in this isolated feather specimen. Using a phylogenetically diverse database of extant bird feathers, statistical analysis of melanosome morphology predicts that the original colour of this Archaeopteryx feather was black, with 95% probability. Furthermore, reexamination of the feather's morphology leads us to interpret it as an upper major primary covert, contrary to previous interpretations. Additional findings reveal that the specimen is preserved as an organosulphur residue, and that barbule microstructure identical to that of modern bird feathers had evolved as early as the Jurassic. As in extant birds, the extensive melanization would have provided structural advantages to the Archaeopteryx wing feather during this early evolutionary stage of dinosaur flight.

  18. Biosynthetic origin of natural products isolated from marine microorganism-invertebrate assemblages.

    PubMed

    Simmons, T Luke; Coates, R Cameron; Clark, Benjamin R; Engene, Niclas; Gonzalez, David; Esquenazi, Eduardo; Dorrestein, Pieter C; Gerwick, William H

    2008-03-25

    In all probability, natural selection began as ancient marine microorganisms were required to compete for limited resources. These pressures resulted in the evolution of diverse genetically encoded small molecules with a variety of ecological and metabolic roles. Remarkably, many of these same biologically active molecules have potential utility in modern medicine and biomedical research. The most promising of these natural products often derive from organisms richly populated by associated microorganisms (e.g., marine sponges and ascidians), and often there is great uncertainty about which organism in these assemblages is making these intriguing metabolites. To use the molecular machinery responsible for the biosynthesis of potential drug-lead natural products, new tools must be applied to delineate their genetic and enzymatic origins. The aim of this perspective is to highlight both traditional and emerging techniques for the localization of metabolic pathways within complex marine environments. Examples are given from the literature as well as recent proof-of-concept experiments from the authors' laboratories.

  19. Effects of redecoration of a hospital isolation room with natural materials on stress levels of denizens in cold season

    NASA Astrophysics Data System (ADS)

    Ohta, Hiromi; Maruyama, Megumi; Tanabe, Yoko; Hara, Toshiko; Nishino, Yoshihiko; Tsujino, Yoshio; Morita, Eishin; Kobayashi, Shotai; Shido, Osamu

    2008-05-01

    We investigated the effects of redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal parameters of healthy subjects staying in the room. Two isolation rooms with almost bilaterally-symmetrical arrangements were used. One room (RD) was redecorated with wood paneling and Japanese paper, while the other (CN) was unchanged (with concrete walls). Seven healthy male subjects stayed in each room for over 24 h in the cold season. Their rectal temperature (Tre) and heart rate, and the room temperature (Ta) and relative humidity were continuously measured. Arterial blood pressures, arterial vascular compliance, thermal sensation and thermal comfort were measured every 4 h except during sleeping. Blood was sampled after the stay in the rooms. In RD, Ta was significantly higher by about 0.4°C and relative humidity was lower by about 5% than in CN. Diurnal Tre levels of subjects in RD significantly differed from those in CN, i.e., Tres were significantly higher in RD than in CN especially in the evening. In RD, the subjects felt more thermally-comfortable than in CN. Redecoration had minimal effects on cardiovascular parameters. Plasma levels of catecholamines and antidiuretic hormone did not differ, while plasma cortisol level was significantly lower after staying in RD than in CN by nearly 20%. The results indicate that, in the cold season, redecoration with natural materials improves the thermal environment of the room and contributes to maintaining core temperature of denizens at preferable levels. It also seems that redecoration of room could attenuate stress levels of isolated subjects.

  20. Effects of redecoration of a hospital isolation room with natural materials on stress levels of denizens in cold season.

    PubMed

    Ohta, Hiromi; Maruyama, Megumi; Tanabe, Yoko; Hara, Toshiko; Nishino, Yoshihiko; Tsujino, Yoshio; Morita, Eishin; Kobayashi, Shotai; Shido, Osamu

    2008-05-01

    We investigated the effects of redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal parameters of healthy subjects staying in the room. Two isolation rooms with almost bilaterally-symmetrical arrangements were used. One room (RD) was redecorated with wood paneling and Japanese paper, while the other (CN) was unchanged (with concrete walls). Seven healthy male subjects stayed in each room for over 24 h in the cold season. Their rectal temperature (T(re)) and heart rate, and the room temperature (T(a)) and relative humidity were continuously measured. Arterial blood pressures, arterial vascular compliance, thermal sensation and thermal comfort were measured every 4 h except during sleeping. Blood was sampled after the stay in the rooms. In RD, T(a) was significantly higher by about 0.4 degrees C and relative humidity was lower by about 5% than in CN. Diurnal T(re) levels of subjects in RD significantly differed from those in CN, i.e., T(re)s were significantly higher in RD than in CN especially in the evening. In RD, the subjects felt more thermally-comfortable than in CN. Redecoration had minimal effects on cardiovascular parameters. Plasma levels of catecholamines and antidiuretic hormone did not differ, while plasma cortisol level was significantly lower after staying in RD than in CN by nearly 20%. The results indicate that, in the cold season, redecoration with natural materials improves the thermal environment of the room and contributes to maintaining core temperature of denizens at preferable levels. It also seems that redecoration of room could attenuate stress levels of isolated subjects.

  1. The parasite connection in ecosystems and macroevolution

    NASA Astrophysics Data System (ADS)

    Seilacher, Adolf; Reif, Wolf-Ernst; Wenk, Peter

    2007-03-01

    In addition to their obvious negative effects (“pathogens”), endoparasites of various kinds play an important role in shaping and maintaining modern animal communities. In the long-term, parasites including pathogens are indispensable entities of any ecosystem. To understand this, it is essential that one changes the viewpoint from the host’s interests to that of the parasite. Together with geographic isolation, trophic arms race, symbiosis, and niche partitioning, all parasites (including balance strategists, i.e. seemingly non-pathogenic ones) modulate their hosts’ population densities. In addition, heteroxenic parasites control the balance between predator and prey species, particularly if final and intermediate hosts are vertebrates. Thereby, such parasites enhance the bonds in ecosystems and help maintain the status quo. As the links between eukaryotic parasites and their hosts are less flexible than trophic connections, parasite networks probably contributed to the observed stasis and incumbency of ecosystems over geologic time, in spite of continuous Darwinian innovation. Because heteroxenic parasites target taxonomic levels above that of the species (e.g. families), these taxa may have also become units of selection in global catastrophies. Macroevolutionary extrapolations, however, are difficult to verify because endoparasites cannot fossilize.

  2. The parasite connection in ecosystems and macroevolution.

    PubMed

    Seilacher, Adolf; Reif, Wolf-Ernst; Wenk, Peter

    2007-03-01

    In addition to their obvious negative effects ("pathogens"), endoparasites of various kinds play an important role in shaping and maintaining modern animal communities. In the long-term, parasites including pathogens are indispensable entities of any ecosystem. To understand this, it is essential that one changes the viewpoint from the host's interests to that of the parasite. Together with geographic isolation, trophic arms race, symbiosis, and niche partitioning, all parasites (including balance strategists, i.e. seemingly non-pathogenic ones) modulate their hosts' population densities. In addition, heteroxenic parasites control the balance between predator and prey species, particularly if final and intermediate hosts are vertebrates. Thereby, such parasites enhance the bonds in ecosystems and help maintain the status quo. As the links between eukaryotic parasites and their hosts are less flexible than trophic connections, parasite networks probably contributed to the observed stasis and incumbency of ecosystems over geologic time, in spite of continuous Darwinian innovation. Because heteroxenic parasites target taxonomic levels above that of the species (e.g. families), these taxa may have also become units of selection in global catastrophies. Macroevolutionary extrapolations, however, are difficult to verify because endoparasites cannot fossilize.

  3. Post-irradiation viability and cytotoxicity of natural killer cells isolated from human peripheral blood using different methods.

    PubMed

    Hietanen, Tenho; Pitkänen, Maunu; Kapanen, Mika; Kellokumpu-Lehtinen, Pirkko-Liisa

    2016-01-01

    Purpose We compared the pre- and post-irradiation viability and cytotoxicity of human peripheral natural killer cell (NK) populations obtained using different isolation methods. Material and methods Three methods were used to enrich total NK cells from buffy coats: (I) a Ficoll-Paque gradient, plastic adherence and a nylon wool column; (II) a discontinuous Percoll gradient; or (III) the Dynal NK cell isolation kit. Subsequently, CD16(+) and CD56(+) NK cell subsets were collected using (IV) flow cytometry or (V) magnetic-activated cell sorting (MACS) NK cell isolation kits. The yield, viability, purity and cytotoxicity of the NK cell populations were measured using trypan blue exclusion, flow cytometry using propidium iodide and (51)Cr release assays after enrichments as well as viability and cytotoxicity after a single radiation dose. Results The purity of the preparations, as measured by the CD16(+) and CD56(+) cell content, was equally good between methods I-III (p = 0.323), but the content of CD16(+) and CD56(+) cells using these methods was significantly lower than that using methods IV and V (p = 0.005). The viability of the cell population enriched via flow cytometry (85.5%) was significantly lower than that enriched via other methods (99.4-98.0%, p = 0.003). The cytotoxicity of NK cells enriched using methods I-III was significantly higher than that of NK cells enriched using methods IV and V (p = 0.000). In vitro the NK cells did not recover cytotoxic activity following irradiation. In addition, we detected considerable inter-individual variation in yield, cytotoxicity and radiation sensitivity between the NK cells collected from different human donors. Conclusions The selection of the appropriate NK cell enrichment method is very important for NK cell irradiation studies. According to our results, the Dynal and MACS NK isolation kits best retained the killing capacity and the viability of irradiated NK cells.

  4. Digenean metacercariae parasites as natural tags of habitat use by 0-group common sole Solea solea in nearshore coastal areas: A case study in the embayed system of the Pertuis Charentais (Bay of Biscay, France)

    NASA Astrophysics Data System (ADS)

    Durieux, Eric D. H.; Bégout, Marie-Laure; Pinet, Patrick; Sasal, Pierre

    2010-07-01

    This study focused on the spatio-temporal variation in the host-parasite system, 0-group sole-digenean metacercariae, in nearshore coastal areas at relatively small spatial scale. 0-group soles were sampled using a standard beam trawl in April, May, June, August and October 2005 at nine different sites in the Pertuis Charentais area (Bay of Biscay, France). Sole density, size, Fulton's condition factor K and digenean metacercariae communities were analysed. 0-group sole concentrated in shallow and muddy areas where they accumulated digenean metacercariae. Parasite communities displayed strong spatial patterns tightly linked to the distribution of the first intermediate mollusc hosts. These parasitological data suggest that 0-group sole during their first period of growth are mainly sedentary with limited movements between the different parts of the habitat. Size and density data revealed spatial heterogeneity in terms of habitat quality so that a limited zone (Aiguillon Bay) within the study area could be identified as sensu stricto nursery habitat for 0-group sole. The use of digenean metacercariae as natural tags appears as a novel powerful tool to evaluate habitat use and movements of juvenile flatfish, which could find applications in fisheries and coastal zone management programs.

  5. Isolation and RFLP Genotyping of Toxoplasma gondii in Free-Range Chickens (Gallus domesticus) in Grenada, West Indies, Revealed Widespread and Dominance of Clonal Type III Parasites.

    PubMed

    Chikweto, Alfred; Sharma, Ravindra N; Tiwari, Keshaw P; Verma, Shiv K; Calero-Bernal, Rafael; Jiang, Tiantian; Su, Chunlei; Kwok, Oliver C; Dubey, Jitender P

    2017-02-01

    The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to other genotypes in Grenada.

  6. [The taxonomy of the Baku virus (BAKV; Reoviridae, Orbivirus) isolated from the birds obligate parasites Argasidae ticks in Azerbaijan, Turkmenistan, and Uzbekistan].

    PubMed

    Al'khovskiĭ, S V; L'vov, D K; Shchelkanov, M Iu; Shchetinin, A M; Deriabin, P G; Gitel'man, A K; Botikov, A R; Samokhvalov, E I

    2013-01-01

    The Baku virus (BAKV) was originally isolated from the ticks Ornithodoros capensis Neumann, 1901 (Acari: Argasidae) collected from the seagull (Larus argentatus) seating nests on the islands of the Baku archipelago, the Caspian sea. BAKV was assigned to Kemerovo group (KEMV) (Orbivirus, Reoviridae). The BAKV was frequently isolated from the ticks O. coniceps Canestrini, 1980, collected from L. argentatus and tern (Sterna hirundo) nests in Turkmenia and pigeon (Columba livia neglecta) nests in Uzbekistan. In this work, the genome of the BAKV was sequenced using the next-generation sequencing technology. The BAKV Pol protein has 48.6% identity level with the viruses of the Great Island Virus group and at average 41% with non-tick orbiviruses. The BAKV T2 protein level identity with the orbiviruses ranges from 23.7% to 64.8%. The maximum identity level of the T2 protein (64.8%) is observed for the tick-borne viruses of the GIV (KEMV) group. According to the conducted molecular-genetic and phylogenetic analysis, the BAKV is a novel species of the genus Orbivirus. It forms a phylogenetic group distinctly related to the GIV group.

  7. Diversity of Clinical and Environmental Isolates of Vibrio cholerae in Natural Transformation and Contact-Dependent Bacterial Killing Indicative of Type VI Secretion System Activity

    PubMed Central

    Bernardy, Eryn E.; Turnsek, Maryann A.; Wilson, Sarah K.; Tarr, Cheryl L.

    2016-01-01

    The bacterial pathogen Vibrio cholerae can occupy both the human gut and aquatic reservoirs, where it may colonize chitinous surfaces that induce the expression of factors for three phenotypes: chitin utilization, DNA uptake by natural transformation, and contact-dependent bacterial killing via a type VI secretion system (T6SS). In this study, we surveyed a diverse set of 53 isolates from different geographic locales collected over the past century from human clinical and environmental specimens for each phenotype outlined above. The set included pandemic isolates of serogroup O1, as well as several serogroup O139 and non-O1/non-O139 strains. We found that while chitin utilization was common, only 22.6% of the isolates tested were proficient at chitin-induced natural transformation, suggesting that transformation is expendable. Constitutive contact-dependent killing of Escherichia coli prey, which is indicative of a functional T6SS, was rare among clinical isolates (only 4 of 29) but common among environmental isolates (22 of 24). These results bolster the pathoadaptive model in which tight regulation of T6SS-mediated bacterial killing is beneficial in a human host, whereas constitutive killing by environmental isolates may give a competitive advantage in natural settings. Future sequence analysis of this set of diverse isolates may identify previously unknown regulators and structural components for both natural transformation and T6SS. PMID:26944842

  8. Equine immunity to parasites.

    PubMed

    Klei, T R

    2000-04-01

    Helminths are among the most significant parasites of horses in developed countries. This article examines immune responses against helminth parasites and the implications that immunologic investigations have on vaccine development, improvement of diagnostic procedures, and disease eradication.

  9. Aflatoxin B1 Degradation by Metabolites of Phoma glomerata PG41 Isolated From Natural Substrate Colonized by Aflatoxigenic Aspergillus flavus

    PubMed Central

    Shcherbakova, Larisa; Statsyuk, Natalia; Mikityuk, Oleg; Nazarova, Tatyana; Dzhavakhiya, Vitaly

    2015-01-01

    Background: Aflatoxin B1 (AFB1), produced by Aspergillus flavus, is one of the most life threatening food contaminants causing significant economic losses worldwide. Biological AFB1 degradation by microorganisms, or preferably microbial enzymes, is considered as one of the most promising approaches. Objectives: The current work aimed to study the AFB1-degrading metabolites, produced by Phoma glomerata PG41, sharing a natural substrate with aflatoxigenic A. flavus, and the preliminary determination of the nature of these metabolites. Materials and Methods: The AFB1-degrading potential of PG41 metabolites was determined by a quantitative high performance liquid chromatography (HPLC) of residual AFB1 after 72 hours incubation at 27ºC. The effects of pH, heat, and protease treatment on the AFB1-destroying activity of extracellular metabolites were examined. Results: The AFB1-degrading activity of protein-enriched fractions, isolated from culture liquid filtrate and cell-free extract, is associated with high-molecular-weight components, is time- and pH-dependent, thermolabile, and is significantly reduced by proteinase K treatment. The AFB1 degradation efficiency of these fractions reaches 78% and 66%, respectively. Conclusions: Phoma glomerata PG41 strain sharing natural substrate with toxigenic A. flavus secretes metabolites possessing a significant aflatoxin-degrading activity. The activity is associated mainly with a protein-enriched high-molecular-weight fraction of extracellular metabolites and appears to be of enzymatic origin. PMID:25789135

  10. Parasites and marine invasions: Ecological and evolutionary perspectives

    NASA Astrophysics Data System (ADS)

    Goedknegt, M. Anouk; Feis, Marieke E.; Wegner, K. Mathias; Luttikhuizen, Pieternella C.; Buschbaum, Christian; Camphuysen, Kees (C. J.); van der Meer, Jaap; Thieltges, David W.

    2016-07-01

    Worldwide, marine and coastal ecosystems are heavily invaded by introduced species and the potential role of parasites in the success and impact of marine invasions has been increasingly recognized. In this review, we link recent theoretical developments in invasion ecology with empirical studies from marine ecosystems in order to provide a conceptual framework for studying the role of parasites and their hosts in marine invasions. Based on an extensive literature search, we identified six mechanisms in which invaders directly or indirectly affect parasite and host populations and communities: I) invaders can lose some or all of their parasites during the invasion process (parasite release or reduction), often causing a competitive advantage over native species; II) invaders can also act as a host for native parasites, which may indirectly amplify the parasite load of native hosts (parasite spillback); III) invaders can also be parasites themselves and be introduced without needing co-introduction of the host (introduction of free-living infective stages); IV) alternatively, parasites may be introduced together with their hosts (parasite co-introduction with host); V) consequently, these co-introduced parasites can sometimes also infect native hosts (parasite spillover); and VI) invasive species may be neither a host nor a parasite, but nevertheless affect native parasite host interactions by interfering with parasite transmission (transmission interference). We discuss the ecological and evolutionary implications of each of these mechanisms and generally note several substantial effects on natural communities and ecosystems via i) mass mortalities of native populations creating strong selection gradients, ii) indirect changes in species interactions within communities and iii) trophic cascading and knock-on effects in food webs that may affect ecosystem function and services. Our review demonstrates a wide range of ecological and evolutionary implications of

  11. [The phylogeography of the Yersinia pestis vole strains isolated from the natural foci of caucasian region].

    PubMed

    Platonov, M E; Evseeva, V V; Svetoch, T E; Efremenko, D V; Kuznetsova, I V; Dentovskaia, S V; Kulichenko, A N; Anisimov, A P

    2012-01-01

    57 Y pestis bv. caucasica strains were assayed using molecular typing. The results of these assays indicated the presence within this biovar of the three separate clonal clusters and necessity of detachment of the Leninakan mountain mesofocus (subfocus) from the structure of Transcaucasian-highland focus into self-supporting one, as well as inclusion of a part of the Pre-Araks low-mountain natural plague focus in the capacity of the subfocus along with Pre-Sevan mountain and Zanzegur-Karabakh mountain subfoci into the structure of Transcaucasian-highland focus. It was shown that the strains circulating in the East-Caucasian highland plague focus were the most ancient branch of bv. caucasica or even of the entire Y pestis phylogenetic tree.

  12. Intestinal parasitic infection.

    PubMed

    Park, Mi-Suk; Kim, Ki Whang; Ha, Hyun Kwon; Lee, Dong Ho

    2008-01-01

    In general, gastrointestinal tract is the primary involvement site of parasites during their life cycle. In this article, we will describe amebiasis, ascariasis, and anisakiasis among the many common intestinal parasitic diseases. We will review the epidemiology, life cycles, clinical manifestations and complications, and illustrate detailed imaging findings of intestinal parasites. Recognizing features of parasitic infection is important to establish an early diagnosis that leads to prompt treatment and helps avoid unnecessary surgery.

  13. Effects of dietary n-3 highly unsaturated fatty acids on growth, nonspecific immunity, expression of some immune related genes and disease resistance of large yellow croaker (Larmichthys crocea) following natural infestation of parasites (Cryptocaryon irritans).

    PubMed

    Zuo, Rantao; Ai, Qinghui; Mai, Kangsen; Xu, Wei; Wang, Jun; Xu, Houguo; Liufu, Zhiguo; Zhang, Yanjiao

    2012-02-01

    The study was conducted to investigate the effects of dietary n-3 highly unsaturated fatty acid (n-3 HUFA) on growth, nonspecific immunity, expression of some immune related genes and disease resistance of juvenile large yellow croaker (Larmichthys crocea) following natural infestation of parasites (Cryptocaryon irritans). Six isoproteic and isolipidic diets were formulated with graded levels of n-3 HUFA ranging from 0.15% to 2.25% of the dry weight and the DHA/EPA was approximately fixed at 2.0. Each diet was randomly allocated to triplicate groups of fish in floating sea cages (1.0 × 1.0 × 1.5 m), and each cage was stocked with 60 fish (initial average weight 9.79 ± 0.6 g). Fish were fed twice daily (05:00 and 17:00) to apparent satiation for 58 days. Results showed that moderate n-3 HUFA level (0.98%) significantly enhanced growth compared with the control group (0.15% HUFA) (P < 0.05), while higher n-3 HUFA levels (1.37%, 1.79% and 2.25%) had detrimental effects on the growth though no significance was found (P > 0.05). Nitro blue tetrazolium (NBT) positive leucocytes percentage of head kidney and serum superoxide dismutase (SOD) activity increased with increasing n-3 HUFA from 0.15% to 0.60%, and decreased with further increase of n-3 HUFA from 0.60% to 2.25% (P < 0.05). Serum lysozyme activity increased significantly as n-3 HUFA increased from 0.15% to 1.37%, and then decreased with n-3 HUFA from 1.37% to 2.25% (P > 0.05). There were no significant differences in phagocytosis index (PI) of head kidney leucocytes among dietary treatments (P > 0.05). The hepatic mRNA expression of Toll-like receptor 22 (TLR22) and Myeloid differentiation factor 88 (MyD88) was significantly up-regulated in fish fed the diets with low or moderate levels, while in kidney this increment was only found at specific sampling time during the natural infestation of parasites. The 13 d cumulative mortality rate following natural infestation of parasites decreased

  14. Infected Dendritic Cells Facilitate Systemic Dissemination and Transplacental Passage of the Obligate Intracellular Parasite Neospora caninum in Mice

    PubMed Central

    Collantes-Fernandez, Esther; Arrighi, Romanico B. G.; Álvarez-García, Gema; Weidner, Jessica M.; Regidor-Cerrillo, Javier; Boothroyd, John C.; Ortega-Mora, Luis M.; Barragan, Antonio

    2012-01-01

    The obligate intracellular parasite Neospora caninum disseminates across the placenta and the blood-brain barrier, to reach sites where it causes severe pathology or establishes chronic persistent infections. The mechanisms used by N. caninum to breach restrictive biological barriers remain elusive. To examine the cellular basis of these processes, migration of different N. caninum isolates (Nc-1, Nc-Liverpool, Nc-SweB1 and the Spanish isolates: Nc-Spain 3H, Nc-Spain 4H, Nc-Spain 6, Nc-Spain 7 and Nc-Spain 9) was studied in an in vitro model based on a placental trophoblast-derived BeWo cell line. Here, we describe that infection of dendritic cells (DC) by N. caninum tachyzoites potentiated translocation of parasites across polarized cellular monolayers. In addition, powered by the parasite's own gliding motility, extracellular N. caninum tachyzoites were able to transmigrate across cellular monolayers. Altogether, the presented data provides evidence of two putative complementary pathways utilized by N. caninum, in an isolate-specific fashion, for passage of restrictive cellular barriers. Interestingly, adoptive transfer of tachyzoite-infected DC in mice resulted in increased parasitic loads in various organs, e.g. the central nervous system, compared to infections with free parasites. Inoculation of pregnant mice with infected DC resulted in an accentuated vertical transmission to the offspring with increased parasitic loads and neonatal mortality. These findings reveal that N. caninum exploits the natural cell trafficking pathways in the host to cross cellular barriers and disseminate to deep tissues. The findings are indicative of conserved dissemination strategies among coccidian apicomplexan parasites. PMID:22403627

  15. The quality of meat from sheep treated with tannin- and saponin-based remedies as a natural strategy for parasite control.

    PubMed

    Brogna, D M R; Tansawat, R; Cornforth, D; Ward, R; Bella, M; Luciano, G; Priolo, A; Villalba, J

    2014-02-01

    Lambs were assigned to four groups of seven and treated as follows for 12 days: control group (BP) was fed beet pulp; group T (tannin remedy) received the BP diet including 80 g/kg of quebracho extract; group S (saponin remedy) received the BP diet including 15 g/kg of quillaja extract; and group C had a free choice between T and S remedies. Lipid oxidation was lower in meat from S lambs compared to T lambs (P<0.05). Among the volatile compounds, lactate was lower in meat from S lambs compared to T animals (P=0.05). Metabolomic analysis showed that the T treatment increased ribose, fructose, glucose and sorbitol concentration in meat (P<0.05), while cholesterol was decreased by S and C treatments. The T treatment increased the concentration of C14:1 cis-9 (P<0.05). These findings indicate that treatments for parasite control containing tannins and saponins do not detrimentally affect sheep meat quality.

  16. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    SciTech Connect

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  17. Parasites, Plants, and People.

    PubMed

    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.

  18. Implications of bioactive solute transfer from hosts to parasitic plants.

    PubMed

    Smith, Jason D; Mescher, Mark C; De Moraes, Consuelo M

    2013-08-01

    Parasitic plants--which make their living by extracting nutrients and other resources from other plants--are important components of many natural ecosystems; and some parasitic species are also devastating agricultural pests. To date, most research on plant parasitism has focused on nutrient transfer from host to parasite and the impacts of parasites on host plants. Far less work has addressed potential effects of the translocation of bioactive non-nutrient solutes-such as phytohormones, secondary metabolites, RNAs, and proteins-on the development and physiology of parasitic plants and on their subsequent interactions with other organisms such as insect herbivores. A growing number of recent studies document the transfer of such molecules from hosts to parasites and suggest that they may have significant impacts on parasite physiology and ecology. We review this literature and discuss potential implications for management and priorities for future research.

  19. Variations in mitochondrial membrane potential correlate with malic acid production by natural isolates of Saccharomyces cerevisiae sake strains.

    PubMed

    Oba, Takahiro; Kusumoto, Kenichi; Kichise, Yuki; Izumoto, Eiji; Nakayama, Shunichi; Tashiro, Kosuke; Kuhara, Satoru; Kitagaki, Hiroshi

    2014-08-01

    Research on the relationship between mitochondrial membrane potential and fermentation profile is being intensely pursued because of the potential for developing advanced fermentation technologies. In the present study, we isolated naturally occurring strains of yeast from sake mash that produce high levels of malic acid and demonstrate that variations in mitochondrial membrane potential correlate with malic acid production. To define the underlying biochemical mechanism, we determined the activities of enzymes required for malic acid synthesis and found that pyruvate carboxylase and malate dehydrogenase activities in strains that produce high levels of malic acid were elevated compared with the standard sake strain K901. These results inspired us to hypothesize that decreased mitochondrial membrane potential was responsible for increased malic acid synthesis, and we present data supporting this hypothesis. Thus, the mitochondrial membrane potential of high malic acid producers was lower compared with standard strains. We conclude that mitochondrial membrane potential correlates with malic acid production.

  20. Molecular and Technological Characterization of Saccharomyces cerevisiae Strains Isolated from Natural Fermentation of Susumaniello Grape Must in Apulia, Southern Italy

    PubMed Central

    Tristezza, Mariana; Fantastico, Lorenagostina; Vetrano, Cosimo; Corallo, Daniela; Grieco, Francesco; Mita, Giovanni

    2014-01-01

    The characterization of autochthonous Saccharomyces cerevisiae strains is an important step towards the conservation and employment of microbial biodiversity. The utilization of selected autochthonous yeast strains would be a powerful tool to enhance the organoleptic and sensory properties of typical regional wines. In fact, indigenous yeasts are better tailored to a particular must and because of this they are able to praise the peculiarities of the derived wine. The present study described the biodiversity of indigenous S. cerevisiae strains isolated from natural must fermentations of an ancient and recently rediscovered Apulian grape cultivar, denoted as “Susumaniello.” The yeast strains denoted by the best oenological and technological features were identified and their fermentative performances were tested by either laboratory assay. Five yeast strains showed that they could be excellent candidates for the production of industrial starter cultures, since they dominated the fermentation process and produced wines characterized by peculiar oenological and organoleptic features. PMID:24672552

  1. Molecular and Technological Characterization of Saccharomyces cerevisiae Strains Isolated from Natural Fermentation of Susumaniello Grape Must in Apulia, Southern Italy.

    PubMed

    Tristezza, Mariana; Fantastico, Lorenagostina; Vetrano, Cosimo; Bleve, Gianluca; Corallo, Daniela; Grieco, Francesco; Mita, Giovanni; Grieco, Francesco

    2014-01-01

    The characterization of autochthonous Saccharomyces cerevisiae strains is an important step towards the conservation and employment of microbial biodiversity. The utilization of selected autochthonous yeast strains would be a powerful tool to enhance the organoleptic and sensory properties of typical regional wines. In fact, indigenous yeasts are better tailored to a particular must and because of this they are able to praise the peculiarities of the derived wine. The present study described the biodiversity of indigenous S. cerevisiae strains isolated from natural must fermentations of an ancient and recently rediscovered Apulian grape cultivar, denoted as "Susumaniello." The yeast strains denoted by the best oenological and technological features were identified and their fermentative performances were tested by either laboratory assay. Five yeast strains showed that they could be excellent candidates for the production of industrial starter cultures, since they dominated the fermentation process and produced wines characterized by peculiar oenological and organoleptic features.

  2. The natural yeast extract isolated by ethanol precipitation inhibits melanin synthesis by modulating tyrosinase activity and downregulating melanosome transfer.

    PubMed

    Lee, Woo Jin; Rhee, Do Young; Bang, Seung Hyun; Kim, Su Yeon; Won, Chong Hyun; Lee, Mi Woo; Choi, Jee Ho; Chang, Sung Eun

    2015-01-01

    This study was conducted to examine the effects of EP-2, a natural yeast extract isolated by ethanol precipitation from Saccharomyces cerevisiae, on melanogenesis and to determine its underlying mechanism of action. Our results show that although EP-2 is not a direct tyrosinase inhibitor, when EP-2 was added to the culture media of B16F10 melanoma cells, intracellular tyrosinase activity was decreased. However, EP-2 had no effect on the expression of microphthalmia-associated transcription factor or tyrosinase. EP-2 was found to inhibit melanogenesis and melanosome transfer when it was added to melanocytes and keratinocytes in coculture. In addition, protease-activated receptor 2, a key protein associated with melanosome transfer from melanocytes to keratinocytes, was downregulated in the presence of EP-2. In conclusion, EP-2 is a potent inhibitor of melanogenesis and its hypomelanogenic effect is related to the inhibition of tyrosinase activity and transfer of melanosomes.

  3. Host-specific races in the holoparasitic angiosperm Orobanche minor: implications for speciation in parasitic plants

    PubMed Central

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

    2009-01-01

    Background and Aims Orobanche minor is a root-holoparasitic angiosperm that attacks a wide range of host species, including a number of commonly cultivated crops. The extent to which genetic divergence among natural populations of O. minor is influenced by host specificity has not been determined previously. Here, the host specificity of natural populations of O. minor is quantified for the first time, and evidence that this species may comprise distinct physiological races is provided. Methods A tripartite approach was used to examine the physiological basis for the divergence of populations occurring on different hosts: (1) host–parasite interactions were cultivated in rhizotron bioassays in order to quantify the early stages of the infection and establishment processes; (2) using reciprocal-infection experiments, parasite races were cultivated on their natural and alien hosts, and their fitness determined in terms of biomass; and (3) the anatomy of the host–parasite interface was investigated using histochemical techniques, with a view to comparing the infection process on different hosts. Key Results Races occurring naturally on red clover (Trifolium pratense) and sea carrot (Daucus carota ssp. gummifer) showed distinct patterns of host specificity: parasites cultivated in cross-infection studies showed a higher fitness on their natural hosts, suggesting that races show local adaptation to specific hosts. In addition, histological evidence suggests that clover and carrot roots vary in their responses to infection. Different root anatomy and responses to infection may underpin a physiological basis for host specificity. Conclusions It is speculated that host specificity may isolate races of Orobanche on different hosts, accelerating divergence and ultimately speciation in this genus. The rapid life cycle and broad host range of O. minor make this species an ideal model with which to study the interactions of parasitic plants with their host associates. PMID

  4. Mosquitocidal Properties of Natural Product Compounds Isolated From Chinese Herbs and Synthetic Analogs of Curcumin

    PubMed Central

    ANSTROM, DAVID M.; ZHOU, XIA; KALK, CODY N.; SONG, BAOAN; LAN, QUE

    2012-01-01

    Because of resistance to current insecticides and to environmental, health, and regulatory concerns, naturally occurring compounds and their derivatives are of increasing interest for the development of new insecticidal compounds against vectors of disease-causing pathogens. Fifty-eight compounds, either extracted and purified from plants native to China or synthetic analogs of curcumin, were evaluated for both their larvicidal activity against Aedes aegypti (L.) and their ability to inhibit binding of cholesterol to Ae. aegypti sterol carrier protein-2 in vitro. Of the compounds tested, curcumin analogs seem especially promising in that of 24 compounds tested five were inhibitors of Ae. aegyptisterol carrier protein-2 with EC50 values ranging from 0.65 to 62.87 μM, and three curcumin analogs exhibited larvicidal activity against fourth instar Ae. aegypti larvae with LC50 values ranging from 17.29 to 27.90 μM. Adding to the attractiveness of synthetic curcumin analogs is the relative ease of synthesizing a large diversity of compounds; only a small fraction of such diversity has been sampled in this study. PMID:22493854

  5. Isolation of human intestinal bacteria metabolizing the natural isoflavone glycosides daidzin and genistin.

    PubMed

    Hur, H G; Lay, J O; Beger, R D; Freeman, J P; Rafii, F

    2000-12-01

    Fecal bacteria from a healthy individual were screened for the specific bacteria involved in the metabolism of dietary isoflavonoids. Two strains of bacteria capable of producing primary and secondary metabolites from the natural isoflavone glycosides daidzin and genistin were detected. The metabolites were identified by comparison of their HPLC/mass, 1H NMR and UV spectra with those of standard and synthetic compounds. Both Escherichia coli HGH21 and the gram-positive strain HGH6 converted daidzin and genistin to the their respective aglycones daidzein and genistein. Under anoxic conditions, strain HGH6 further metabolized the isoflavones daidzein and genistein to dihydrodaidzein and dihydrogenistein, respectively. The reduction of a double bond between C-2 and C-3 to a single bond was isoflavonoid-specific by strain HGH6, which did not reduce a similar bond in the flavonoids apigenin and chrysin. Strain HGH6 did not further metabolize dihydrodaidzein and dihydrogenistein. This is the first study in which specific colonic bacteria that are involved in the metabolism of daidzin and genistin have been detected.

  6. Comparisons of recombinant protein expression in diverse natural isolates of Escherichia coli.

    PubMed

    Jung, Yuna; Lim, Dongbin

    2008-05-31

    We assessed heterologous protein expression in 64 strains obtained from the Escherichia coli Reference (ECOR) collection, a collection representing diverse natural E. coli populations. A plasmid generating a glutathione S-transferase and plant carbonic anhydrase fusion protein (GST-CA) under the control of the tac promoter was introduced into the ECOR strains, and the quantity of the fusion protein was determined by SDS-PAGE. The foreign protein was generated at various levels, from very high (40 strains, high producers) to very low (six strains, low producers). Immunoblotting showed that the high producers expressed approximately 250-500 times more GST-CA protein than the low producers. The results of semi-quantitative RT-PCR showed that the low producers generated mRNA levels comparable to those of the high producers, thereby suggesting that, at least in this case, inefficient translation is a major cause of the low production. We introduced a different plasmid, which expressed a maltose binding protein and plant guanylate kinase fusion protein (MBP-GK) into the six low producers. Interestingly, five of these expressed MBP-GK at very high levels. Thus, we conclude that the production of a particular protein from an expression vector can vary considerably, depending on the host strain. Strains in the ECOR collection could function as useful alternative hosts when a desired level of protein expression is not obtained from commonly used strains, such as E. coli K12 or B derivatives.

  7. Potential Parasite Transmission in Multi-Host Networks Based on Parasite Sharing

    PubMed Central

    Pilosof, Shai; Morand, Serge; Krasnov, Boris R.; Nunn, Charles L.

    2015-01-01

    Epidemiological networks are commonly used to explore dynamics of parasite transmission among individuals in a population of a given host species. However, many parasites infect multiple host species, and thus multi-host networks may offer a better framework for investigating parasite dynamics. We investigated the factors that influence parasite sharing – and thus potential transmission pathways – among rodent hosts in Southeast Asia. We focused on differences between networks of a single host species and networks that involve multiple host species. In host-parasite networks, modularity (the extent to which the network is divided into subgroups of rodents that interact with similar parasites) was higher in the multi-species than in the single-species networks. This suggests that phylogeny affects patterns of parasite sharing, which was confirmed in analyses showing that it predicted affiliation of individuals to modules. We then constructed “potential transmission networks” based on the host-parasite networks, in which edges depict the similarity between a pair of individuals in the parasites they share. The centrality of individuals in these networks differed between multi- and single-species networks, with species identity and individual characteristics influencing their position in the networks. Simulations further revealed that parasite dynamics differed between multi- and single-species networks. We conclude that multi-host networks based on parasite sharing can provide new insights into the potential for transmission among hosts in an ecological community. In addition, the factors that determine the nature of parasite sharing (i.e. structure of the host-parasite network) may impact transmission patterns. PMID:25748947

  8. Unraveling genomic and phenotypic nature of multidrug-resistant (MDR) Pseudomonas aeruginosa VRFPA04 isolated from keratitis patient.

    PubMed

    N, Murugan; J, Malathi; V, Umashankar; H N, Madhavan

    2016-12-01

    Multidrug-resistant (MDR) Pseudomonas aeruginosa VRFPA04, obtained from a keratitis patient was found to exhibit resistance to betalactam (Penicillins, cephalosporins, including carbapenems, except aztreonam), aminoglycosides, quinolone group of drugs and susceptible to colistin. The complete genome sequencing of the ocular isolate to measure and ascertain the degree of multidrug resistance in VRFPA04 strain resulted in 6,818,030bp (6.8Mb) genome sizes, which happen to be the third largest genome available in the Genbank to date. Two chromosomally integrated class I integrons carrying blaVIM-2 carbapenemase gene, multiple secretory systems consisting of types I-VI and VIII proteins and ocular virulence factors exo-T, Y, U and exotoxin A, a gene that inhibits protein synthesis which could have caused corneal cell death and Phytohormone auxin biosynthetic protein were detected in the genome of VRFPA04 Genome. In addition, 58 Regions of Genomic Plasticity (RGPs) regions, multiple phage genomes, genomic islands, CRISPR genes and RND family efflux pumps, such as MexCD-OprJ and MexEF-OprN and its regulators, MexT and MexR, were unraveled in VRFPA04. Thus, the current study reveals the virulence factors and resistome nature of an ocular isolate P aeruginosa VRFPA04 genome.

  9. Biocontrol of tomato wilt disease by Bacillus subtilis isolates from natural environments depends on conserved genes mediating biofilm formation

    PubMed Central

    Liu, Hongxia; Kolter, Roberto; Losick, Richard; Guo, Jian-hua

    2014-01-01

    Summary Bacillus subtilis and other Bacilli have long been used as biological control agents against plant bacterial diseases but the mechanisms by which the bacteria confer protection are not well understood. Our goal in this study was to isolate strains of B. subtilis that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. We screened a total of sixty isolates collected from various locations across China and obtained six strains that exhibited above 50% biocontrol efficacy on tomato plants against the plant pathogen Ralstonia solanacearum under greenhouse conditions. These wild strains were able to form robust biofilms both in defined medium and on tomato plant roots and exhibited strong antagonistic activities against various plant pathogens in plate assays. We show that plant protection by those strains depended on widely conserved genes required for biofilm formation, including regulatory genes and genes for matrix production. We provide evidence suggesting that matrix production is critical for bacterial colonization on plant root surfaces. Finally, we have established a model system for studies of B. subtilis-tomato plant interactions in protection against a plant pathogen. PMID:22934631

  10. Methanolobus profundi sp. nov., a methylotrophic methanogen isolated from deep subsurface sediments in a natural gas field.

    PubMed

    Mochimaru, Hanako; Tamaki, Hideyuki; Hanada, Satoshi; Imachi, Hiroyuki; Nakamura, Kohei; Sakata, Susumu; Kamagata, Yoichi

    2009-04-01

    A mesophilic, methylotrophic methanogen, strain MobM(T), was isolated from a natural gas field in Japan. Strain MobM(T) grew on methanol and methylamines, but not on H(2)/CO(2), formate, acetate or dimethyl sulfide. The cells were motile, irregular cocci (diameter, 0.9-1.2 microm) and occurred singly, in pairs, as tetracocci or (occasionally) as aggregates. Strain MobM(T) grew at 9-37 degrees C (optimally at 30 degrees C) and at pH 6.1-7.8 (optimally at pH 6.5). Sodium and magnesium were required for growth, at 0.1-1.0 M Na(+) (optimally at 0.35 M) and 10-400 mM Mg(2+) (optimally at 15-25 mM). The G+C content of the genomic DNA was 42.4 mol%. 16S rRNA gene sequencing revealed that the isolate is a member of the genus Methanolobus, but distinct from its closest neighbours, Methanolobus tindarius DSM 2278(T) (sequence similarity, 98.0 %) and Methanolobus vulcani DSM 3029(T) (98.1 %). On the basis of phenotypic and phylogenetic features of MobM(T), it is clear that this strain represents a novel species of the genus Methanolobus, for which the name Methanolobus profundi sp. nov. is proposed. The type strain is MobM(T) (=DSM 21213(T)=NBRC 104158(T)).

  11. Pseudomonas granadensis sp. nov., a new bacterial species isolated from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain.

    PubMed

    Pascual, Javier; García-López, Marina; Bills, Gerald F; Genilloud, Olga

    2015-02-01

    During the course of screening bacterial isolates as sources of as-yet unknown bioactive compounds with pharmaceutical applications, a chemo-organotrophic, Gram-negative bacterium was isolated from a soil sample taken from the Tejeda, Almijara and Alhama Natural Park, Granada, Spain. Strain F-278,770(T) was oxidase- and catalase-positive, aerobic, with a respiratory type of metabolism with oxygen as the terminal electron acceptor, non-spore-forming and motile by one polar flagellum, although some cells had two polar flagella. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-278,770(T) belongs to the Pseudomonas koreensis subgroup (Pseudomonas fluorescens lineage), with Pseudomonas moraviensis, P. koreensis, P. baetica and P. helmanticensis as its closest relatives. Chemotaxonomic traits such as polar lipid and fatty acid compositions and G+C content of genomic DNA corroborated the placement of strain F-278,770(T) in the genus Pseudomonas. DNA-DNA hybridization assays and phenotypic traits confirmed that this strain represents a novel species of the genus Pseudomonas, for which the name Pseudomonas granadensis sp. nov. is proposed. The type strain is F-278,770(T) ( = DSM 28040(T) = LMG 27940(T)).

  12. Brevibacillus laterosporus strain BPM3, a potential biocontrol agent isolated from a natural hot water spring of Assam, India.

    PubMed

    Saikia, R; Gogoi, D K; Mazumder, S; Yadav, A; Sarma, R K; Bora, T C; Gogoi, B K

    2011-03-20

    A bacterial strain designated as BPM3 isolated from mud of a natural hot water spring of Nambar Wild Life Sanctuary, Assam, India, strongly inhibited growth of phytopathogenic fungi (Fusarium oxysporum f. sp. ciceri, F. semitectum, Magnaporthe grisea and Rhizoctonia oryzae) and gram-positive bacterium (Staphylococcus aureus). The maximum growth and antagonistic activity was recorded at 30°C, pH 8.5 when starch and peptone were amended as carbon and nitrogen sources, respectively. In greenhouse experiment, this bacterium (BPM3) suppressed blast disease of rice by 30-67% and protected the weight loss by 35-56.5%. The maximum disease protection (67%) and weight loss protection (56.5%) were recorded when the bacterium was applied before 2 days of the pathogen inoculation. Antifungal and antibacterial compounds were isolated from the bacterium which also inhibited the growth of these targeted pathogens. The compounds were purified and on spectroscopic analysis of a purified fraction having R(f) 0.22 which showed strong antifungal and antibacterial activity indicated the presence of C-H, carbonyl group, dimethyl group, -CH(2) and methyl group. The bacterium was characterized by morphological, biochemical and molecular approaches and confirmed that the strain BPM3 is Brevibacillus laterosporus.

  13. Foodborne parasites from wildlife: how wild are they?

    PubMed

    Kapel, Christian M O; Fredensborg, Brian L

    2015-04-01

    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.

  14. The evolution of host protection by vertically transmitted parasites

    PubMed Central

    Jones, Edward O.; White, Andrew; Boots, Michael

    2011-01-01

    Hosts are often infected by a variety of different parasites, leading to competition for hosts and coevolution between parasite species. There is increasing evidence that some vertically transmitted parasitic symbionts may protect their hosts from further infection and that this protection may be an important reason for their persistence in nature. Here, we examine theoretically when protection is likely to evolve and its selective effects on other parasites. Our key result is that protection is most likely to evolve in response to horizontally transmitted parasites that cause a significant reduction in host fecundity. The preponderance of sterilizing horizontally transmitted parasites found in arthropods may therefore explain the evolution of protection seen by their symbionts. We also find that protection is more likely to evolve in response to highly transmissible parasites that cause intermediate, rather than high, virulence (increased death rate when infected). Furthermore, intermediate levels of protection select for faster, more virulent horizontally transmitted parasites, suggesting that protective symbionts may lead to the evolution of more virulent parasites in nature. When we allow for coevolution between the symbiont and the parasite, more protection is likely to evolve in the vertically transmitted symbionts of longer lived hosts. Therefore, if protection is found to be common in nature, it has the potential to be a major selective force on host–parasite interactions. PMID:20861052

  15. Population-scale movement of coastal cutthroat trout in a naturally isolated stream network

    USGS Publications Warehouse

    Gresswell, R.E.; Hendricks, S.R.

    2007-01-01

    To identify population-scale patterns of movement, coastal cutthroat trout Oncorhynchus clarkii clarkii tagged and marked (35 radio-tagged, 749 passive integrated transponder [PIT]-tagged, and 3,025 fin-clipped) were monitored from June 1999 to August 2000. The study watershed, located in western Oregon, was above a natural barrier to upstream movement. Emigration out of the watershed was estimated with a rotating fish trap. Approximately 70% of recaptured coastal cutthroat trout with PIT tags and 86% of those with radio tags moved predominantly at the channel-unit scale (2-95 m); fewer tagged fish moved at the reach scale (66-734 m) and segment scale (229-3,479 m). In general, movement was greatest in April as spawning peaked and lowest in October, when discharge was at its lowest. Only 63 (<1% of tagged and marked fish) coastal cutthroat trout were captured in the fish trap. Trap efficiency was about 33%, and the expanded estimate of emigrants between February and June was 173 fish. These results suggest that unit-scale movement is common throughout the year and that reach- and segment-scale movements are important during the winter and spring. Although movement in headwater streams is most common at the channel-unit scale, restoration of individual channel units of stream may not benefit the population at the watershed scale unless these activities are undertaken in the context of the greater whole. Individual coastal cutthroat trout move great distances, even within the small watersheds in the Oregon Coast Range, and although these movements may be infrequent, they may contribute substantially to recolonization after stochastic extirpation events (e.g., landslides and debris flows). Management strategies that focus on maintaining and restoring connectivity in a watershed represent an important step toward protecting the evolutionary capacity of stream salmonids. ??

  16. Cytotoxic and insecticidal activities of derivatives of harmine, a natural insecticidal component isolated from Peganum harmala.

    PubMed

    Zeng, Yong; Zhang, Yaomou; Weng, Qunfang; Hu, Meiying; Zhong, Guohua

    2010-11-02

    In a continuing effort to develop novel β-carbolines endowed with better insecticidal activity, a simple high-yielding method for the synthesis of harmine compounds starting from L-tryptophan has been developed and a series of 1,3-substituted β-carboline derivatives have been synthesized and evaluated for their cytotoxicity against insect cultured Sf9 cell line in vitro and insecticidal activities against 4th instar larvae of mosquitos, Culex pipiens quinquefasciatus and mustard aphid, Lipaphis erysimi. The results demonstrated that 1-phenyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (compound 2) and methyl 1-phenyl-β-carboline-3-carboxylate (compound 13) represented the best potential compounds, with Sf9 cells inhibition rates of 71.55% and 60.21% after 24 h treatment at concentrations of 50-200 mg/L, respectively. Both compounds 2 and 13 also showed strong insecticidal activity towards 4th instar larvae of mosquitos with LC(50) values of 20.82 mg/L and 23.98 mg/L, and their LC(90) values were 88.29 mg/L and 295.13 mg/L, respectively. Furthermore, the LC(50) values of compounds 2 and 13 against mustard aphids were 53.16 mg/L and 68.05 mg/L, and their LC(90) values were 240.10 mg/L and 418.63 mg/L after 48 h treatment. The in vitro cytotoxicity of these compounds was consistent with the insecticidal activity in vivo. The results indicated that the 1- and 3-positions of the β-carboline ring deserve further investigation to develop biorational insecticides based on the natural compound harmine as a lead compound.

  17. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus

    PubMed Central

    Cold, Emma R.; Freyria, Nastasia J.; Martínez Martínez, Joaquín; Fernández Robledo, José A.

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham’s F12–5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham’s F12–5% FBS– 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham’s F12–5% FBS– 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications. PMID:27149378

  18. An Agar-Based Method for Plating Marine Protozoan Parasites of the Genus Perkinsus.

    PubMed

    Cold, Emma R; Freyria, Nastasia J; Martínez Martínez, Joaquín; Fernández Robledo, José A

    2016-01-01

    The genus Perkinsus includes protozoan parasites of mollusks responsible for losses in the aquaculture industry and hampering the recovery of natural shellfish beds worldwide, and they are a key taxon for understanding intracellular parasitism adaptations. The ability to propagate the parasite in liquid media, in the absence of the host, has been crucial for improving understanding of its biology; however, alternative techniques to grow the parasite are needed to explore other basic aspects of the Perkinsus spp. biology. We optimized a DME: Ham's F12-5% FBS- containing solid agar medium for plating Perkinsus marinus. This solid medium supported trophozoite propagation both by binary fission and schizogony. Colonies were visible to the naked eye 17 days after plating. We tested the suitability of this method for several applications, including the following: 1) Subcloning P. marinus isolates: single discrete P. marinus colonies were obtained from DME: Ham's F12-5% FBS- 0.75% agar plates, which could be further propagated in liquid medium; 2) Subcloning engineered Perkinsus mediterraneus MOE[MOE]: GFP by streaking cultures on plates; 3) Chemical susceptibility: Infusing the DME: Ham's F12-5% FBS- 0.75% agar plates with triclosan resulted in inhibition of the parasite propagation in a dose-dependent manner. Altogether, our plating method has the potential for becoming a key tool for investigating diverse aspects of Perkinsus spp. biology, developing new molecular tools, and for biotechnological applications.

  19. Parasites and supernormal manipulation.

    PubMed Central

    Holen, Ø. H.; Saetre, G. P.; Slagsvold, T.; Stenseth, N. C.

    2001-01-01

    Social parasites may exploit their hosts by mimicking other organisms that the hosts normally benefit from investing in or responding to in some other way. Some parasites exaggerate key characters of the organisms they mimic, possibly in order to increase the response from the hosts. The huge gape and extreme begging intensity of the parasitic common cuckoo chick (Cuculus canorus) may be an example. In this paper, the evolutionary stability of manipulating hosts through exaggerated signals is analysed using game theory. Our model indicates that a parasite's signal intensity must be below a certain threshold in order to ensure acceptance and that this threshold depends directly on the rate of parasitism. The only evolutionarily stable strategy (ESS) combination is when hosts accept all signallers and parasites signal at their optimal signal intensity, which must be below the threshold. Supernormal manipulation by parasites is only evolutionarily stable under sufficiently low rates of parasitism. If the conditions for the ESS combination are not satisfied, rejector hosts can invade using signal intensity as a cue for identifying parasites. These qualitative predictions are discussed with respect to empirical evidence from parasitic mimicry systems that have been suggested to involve supernormal signalling, including evicting avian brood parasites and insect-mimicking Ophrys orchids. PMID:11749709

  20. Gastrointestinal parasite infestation.

    PubMed

    Abd El Bagi, Mohamed E; Sammak, Bassam M; Mohamed, Abdulrahman E; Al Karawi, Mohamed A; Al Shahed, Mona; Al Thagafi, Mohamed A

    2004-03-01

    Twenty-five percent of the world's population could be suffering parasitic infestation. Highest prevalence is in underdeveloped agricultural and rural areas in the tropical and subtropical regions. In some areas incidence may reach 90% of the population. In contrast, some major economic projects intended to promote local development have, paradoxically, caused parasitic proliferation, e.g. bilharziasis in Egypt and Sudan and Chagas disease in Brazil. The commonest cosmopolitan gastrointestinal parasite is Entamoeba histolytica. Some intestinal parasite are endemic in temperate climates, e.g. Entrobius vermicularis. The AIDS epidemic has increased the prevalence and severity of parasitic disease, particularly Strongyloides stercolaris. Tropical parasites are seen in Western people who travel to tropical countries. Radiology has acquired a major role in diagnosis and management of gastrointestinal parasite infestations and their complications.

  1. Artemisinin activity-based probes identify multiple molecular targets within the asexual stage of the malaria parasites Plasmodium falciparum 3D7

    PubMed Central

    Ismail, Hanafy M.; Barton, Victoria; Phanchana, Matthew; Charoensutthivarakul, Sitthivut; Wong, Michael H. L.; Hemingway, Janet; Biagini, Giancarlo A.; O’Neill, Paul M.; Ward, Stephen A.

    2016-01-01

    The artemisinin (ART)-based antimalarials have contributed significantly to reducing global malaria deaths over the past decade, but we still do not know how they kill parasites. To gain greater insight into the potential mechanisms of ART drug action, we developed a suite of ART activity-based protein profiling probes to identify parasite protein drug targets in situ. Probes were designed to retain biological activity and alkylate the molecular target(s) of Plasmodium falciparum 3D7 parasites in situ. Proteins tagged with the ART probe can then be isolated using click chemistry before identification by liquid chromatography–MS/MS. Using these probes, we define an ART proteome that shows alkylated targets in the glycolytic, hemoglobin degradation, antioxidant defense, and protein synthesis pathways, processes essential for parasite survival. This work reveals the pleiotropic nature of the biological functions targeted by this important class of antimalarial drugs. PMID:26858419

  2. Triplet photochemistry of effluent and natural organic matter in whole water and isolates from effluent-receiving rivers.

    PubMed

    Bodhipaksha, Laleen C; Sharpless, Charles M; Chin, Yu-Ping; Sander, Michael; Langston, William K; MacKay, Allison A

    2015-03-17

    Effluent organic matter (EfOM), contained in treated municipal wastewater, differs in composition from naturally occurring dissolved organic matter (DOM). The presence of EfOM may thus alter the photochemical production of reactive intermediates in rivers that receive measurable contributions of treated municipal wastewater. Quantum yield coefficients for excited triplet-state OM (3OM*) and apparent quantum yields for singlet oxygen (1O2) were measured for both whole water samples and OM isolated by solid phase extraction from whole water samples collected upstream and downstream of municipal wastewater treatment plant discharges in three rivers receiving differing effluent contributions: Hockanum R., CT (22% (v/v) effluent flow), E. Fork Little Miami R., OH (11%), and Pomperaug R., CT (6%). While only small differences in production of these reactive intermediates were observed between upstream and downstream whole water samples collected from the same river, yields of 3OM* and 1O2 varied by 30-50% between the rivers. Apparent quantum yields of 1O2 followed similar trends to those of 3OM*, consistent with 3OM* as a precursor to 1O2 formation. Higher 3OM* reactivity was observed for whole water samples than for OM isolates of the same water, suggesting differential recoveries of photoreactive moieties by solid phase extraction. 3OM* and 1O2 yields increased with increasing E2/E3 ratio (A254 nm divided by A365 nm) and decreased with increasing electron donating capacities of the samples, thus exhibiting trends also observed for reference humic and fulvic acid isolates. Mixing experiments with EfOM and DOM isolates showed evidence of quenching of triplet DOM by EfOM when measured yields were compared to theoretical yields. Together, the results suggest that effluent contributions of up to 25% (v/v) to river systems have a negligible influence on photochemical production of 3OM* and 1O2 apparently because of quenching of triplet DOM by EfOM. Furthermore, the results

  3. Paradigms for parasite conservation.

    PubMed

    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

  4. Interspecific brood parasitism in blackbirds (Icterinae): a phylogenetic perspective.

    PubMed

    Lanyon, S M

    1992-01-03

    An 852-base pair region of the cytochrome-b gene was sequenced for the brood parasitic cowbirds and 20 additional taxa of the New World blackbirds (Icterinae). The goal of the study was to determine (i) whether interspecific brood parasitism is multiply derived within the assemblage and (ii) the nature of the evolutionary transformation between various forms of interspecific brood parasitism. Cladistic analysis of the sequence data indicates that brood parasitism evolved a single time within the Icterinae. The primitive form of interspecific brood parasitism in this assemblage is host-specificity, with host-generality representing the derived condition.

  5. Formation and stabilization of nanoemulsion-based vitamin E delivery systems using natural biopolymers: Whey protein isolate and gum arabic.

    PubMed

    Ozturk, Bengu; Argin, Sanem; Ozilgen, Mustafa; McClements, David Julian

    2015-12-01

    Natural biopolymers, whey protein isolate (WPI) and gum arabic (GA), were used to fabricate emulsion-based delivery systems for vitamin E-acetate. Stable delivery systems could be formed when vitamin E-acetate was mixed with sufficient orange oil prior to high pressure homogenization. WPI (d32=0.11 μm, 1% emulsifier) was better than GA (d32=0.38 μm, 10% emulsifier) at producing small droplets at low emulsifier concentrations. However, WPI-stabilized nanoemulsions were unstable to flocculation near the protein isoelectric point (pH 5.0), at high ionic strength (>100mM), and at elevated temperatures (>60 °C), whereas GA-stabilized emulsions were stable. This difference was attributed to differences in emulsifier stabilization mechanisms: WPI by electrostatic repulsion; GA by steric repulsion. These results provide useful information about the emulsifying and stabilizing capacities of natural biopolymers for forming food-grade vitamin-enriched delivery systems.

  6. Blending in with the crowd: social parasites integrate into their host colonies using a flexible chemical signature.

    PubMed Central

    D'Ettorre, P; Mondy, N; Lenoir, A; Errard, C

    2002-01-01

    Social parasites are able to exploit their host's communication code and achieve social integration. For colony foundation, a newly mated slave-making ant queen must usurp a host colony. The parasite's brood is cared for by the hosts and newly eclosed slave-making workers integrate to form a mixed ant colony. To elucidate the social integration strategy of the slave-making workers, Polyergus rufescens, behavioural and chemical analyses were carried out. Cocoons of P. rufescens were introduced into subcolonies of four potential host species: Formica subgenus Serviformica (Formica cunicularia and F. rufibarbis, usual host species; F. gagates, rare host; F. selysi, non-natural host). Slave-making broods were cared for and newly emerged workers showed several social interactions with adult Formica. We recorded the occurrence of abdominal trophallaxis, in which P. rufescens, the parasite, was the donor. Social integration of P. rufescens workers into host colonies appears to rely on the ability of the parasite to modify its cuticular hydrocarbon profile to match that of the rearing species. To study the specific P. rufescens chemical profile, newly emerged callows were reared in isolation from the mother colony (without any contact with adult ants). The isolated P. rufescens workers exhibited a chemical profile closely matching that of the primary host species, indicating the occurrence of local host adaptation in the slave-maker population. However, the high flexibility in the ontogeny of the parasite's chemical signature could allow for host switching. PMID:12350253

  7. Genetic isolation between two sympatric host-plant races of the European corn borer, Ostrinia nubilalis Hübner. I. Sex pheromone, moth emergence timing, and parasitism.

    PubMed

    Thomas, Yan; Bethenod, Marie-Thérèse; Pelozuelo, Laurent; Frérot, Brigitte; Bourguet, Denis

    2003-02-01

    Adaptation to different environments may be a powerful source of genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating between individuals of these genetically differentiated populations. This situation may facilitate sympatric speciation. Successful host shifts in phytophagous insects provide some of the best evidence for the ecological speciation that occurs, or has occurred, in sympatry. The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), colonized maize after its introduction into Europe by humans about 500 years ago. In northern France, two sympatric host races feed on maize (Zea mays) and mugwort (Artemisia vulgaris), respectively. We investigated the factors involved in the genetic isolation of these two races at a field site near Paris, France. We identified two biological differences that might make a significant contribution to the genetic divergence between sympatric populations feeding on the two host plants. First, assortative mating may be due to differences in the moth emergence pattern between the two races: mugwort-race moths emerged on average 10 days earlier than maize-race moths. In addition, the males emerged earlier than females in both races. Hence, the likelihood of mating between maize-race males and mugwort-race females was higher than that of mating between mugwort-race males and maize-race females. Second, the females feeding on mugwort and maize produced sex pheromones with different E/Z isomeric ratios of delta-11-tetradecenyl acetate. This difference in mate recognition systems reinforces the potential for assortative mating in the two races. During the experiment, overwintering mortality was much lower on maize than on mugwort. This difference was due to a braconid parasitoid wasp, Macrocentrus cingulum, that killed more than 50% of the larvae overwintering on mugwort but did not infest larvae diapausing on maize. Hence, by

  8. Malaria parasite clearance.

    PubMed

    White, Nicholas J

    2017-02-23

    Following anti-malarial drug treatment asexual malaria parasite killing and clearance appear to be first order processes. Damaged malaria parasites in circulating erythrocytes are removed from the circulation mainly by the spleen. Splenic clearance functions increase markedly in acute malaria. Either the entire infected erythrocytes are removed because of their reduced deformability or increased antibody binding or, for the artemisinins which act on young ring stage parasites, splenic pitting of drug-damaged parasites is an important mechanism of clearance. The once-infected erythrocytes returned to the circulation have shortened survival. This contributes to post-artesunate haemolysis that may follow recovery in non-immune hyperparasitaemic patients. As the parasites mature Plasmodium vivax-infected erythrocytes become more deformable, whereas Plasmodium falciparum-infected erythrocytes become less deformable, but they escape splenic filtration by sequestering in venules and capillaries. Sequestered parasites are killed in situ by anti-malarial drugs and then disintegrate to be cleared by phagocytic leukocytes. After treatment with artemisinin derivatives some asexual parasites become temporarily dormant within their infected erythrocytes, and these may regrow after anti-malarial drug concentrations decline. Artemisinin resistance in P. falciparum reflects reduced ring stage susceptibility and manifests as slow parasite clearance. This is best assessed from the slope of the log-linear phase of parasitaemia reduction and is commonly measured as a parasite clearance half-life. Pharmacokinetic-pharmacodynamic modelling of anti-malarial drug effects on parasite clearance has proved useful in predicting therapeutic responses and in dose-optimization.

  9. Strigolactones: Chemical Signals for Fungal Symbionts and Parasitic Weeds in Plant Roots

    PubMed Central

    AKIYAMA, KOHKI; HAYASHI, HIDEO

    2006-01-01

    • Aims Arbuscular mycorrhizae are formed between >80 % of land plants and arbuscular mycorrhizal (AM) fungi. This Botanical Briefing highlights the chemical identification of strigolactones as a host-recognition signal for AM fungi, and their role in the establishment of arbuscular mycorrhizae as well as in the seed germination of parasitic weeds. • Scope Hyphal branching has long been described as the first morphological event in host recognition by AM fungi during the pre-infection stages. Host roots release signalling molecules called ‘branching factors’ that induce extensive hyphal branching in AM fungi. Strigolactones exuded from host roots have recently been identified as an inducer of hyphal branching in AM fungi. Strigolactones are a group of sesquiterpenes, previously isolated as seed germination stimulants for the parasitic weeds Striga and Orobanche. Parasitic weeds might find their potential hosts by detecting strigolactones, which are released from plant roots upon phosphate deficiency in communication with AM fungi. In addition to acting as a signalling molecule, strigolactones might stimulate the production of fungal symbiotic signals called ‘Myc factors’ in AM fungi. • Conclusions Isolation and identification of plant symbiotic signals open up new ways for studying the molecular basis of plant–AM-fungus interactions. This discovery provides a clear answer to a long-standing question in parasitic plant biology: what is the natural role for germination stimulants? It could also provide a new strategy for the management and control of beneficial fungal symbionts and of devastating parasitic weeds in agriculture and natural ecosystems. PMID:16574693

  10. It's a predator-eat-parasite world: how characteristics of predator, parasite and environment affect consumption.

    PubMed

    Orlofske, Sarah A; Jadin, Robert C; Johnson, Pieter T J

    2015-06-01

    Understanding the effects of predation on disease dynamics is increasingly important in light of the role ecological communities can play in host-parasite interactions. Surprisingly, however, few studies have characterized direct predation of parasites. Here we used an experimental approach to show that consumption of free-living parasite stages is highly context dependent, with significant influences of parasite size, predator size and foraging mode, as well as environmental condition. Among the four species of larval trematodes and two types of predators (fish and larval damselflies) studied here, parasites with larger infective stages (size >1,000 μm) were most vulnerable to predation by fish, while small-bodied fish and damselflies (size <10 mm) consumed the most infectious stages. Small parasite species (size approx. 500 μm) were less frequently consumed by both fish and larval damselflies. However, these results depended strongly on light availability; trials conducted in the dark led to significantly fewer parasites consumed overall, especially those with a size of <1,000 μm, emphasizing the importance of circadian shedding times of parasite free-living stages for predation risk. Intriguingly, active predation functioned to help limit fishes' infection by directly penetrating parasite species. Our results are consistent with established theory developed for predation on zooplankton that emphasizes the roles of body size, visibility and predation modes and further suggest that consumer-resource theory may provide a predictive framework for when predators should significantly influence parasite transmission. These results contribute to our understanding of transmission in natural systems, the role of predator-parasite links in food webs and the evolution of parasite morphology and behavior.

  11. Parasitic infection in various stages life of cultured Acipenser persicus

    PubMed Central

    Adel, Milad; Safari, Reza; Yaghoubzadeh, Zahra; Fazli, Hassan; Khalili, Elham

    2016-01-01

    The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose, sampling from each sex breeder, 10 egg samples, 5-day-old larvae (n = 20), 20-day-old larvae (n = 80) and fingerling of A. persicus (n = 60) released in earthen ponds were done. After the bioassay and preparing wet mount from the internal and external organs, identification was done according to the keys. According to the results, no fauna parasites were isolated from egg samples and 5-day-old larvae; but Trichodina spp. was isolated from 20-day-old larvae. Also, the same protozoan was isolated from fingerling released in earthen ponds, the mean intensity, prevalence and range of contamination by fingerling were higher with compared to 20-day-old larvae. Trichodina sp. and Diplostomum spathaceum were isolated from skin and eyes of females, respectively. However, Trichodina sp. and Ichthyophthirius multifiliis were isolated from skin of male breeders. In this study, no parasites were isolated from internal organs of larves and fingerling but four intestinal parasites included: Cucullanus sphaerocephlaus, Anisakis sp., Skyrjabinopsilus semiarmatus, and Lepto-rhynchoides plagicephalu were isolated from internal organs of breeder. Based on a wide range of parasitic infection observed in various life stages of A. persicus, it seems necessary to consider hygienic and management measures. PMID:27226891

  12. Parasitic infection in various stages life of cultured Acipenser persicus.

    PubMed

    Adel, Milad; Safari, Reza; Yaghoubzadeh, Zahra; Fazli, Hassan; Khalili, Elham

    2016-01-01

    The present study was conducted to evaluate the status of the parasite fauna in Acipenser persicus at different development stages, in order to find prevention protocols for parasitic diseases in this valuable species. For this purpose, sampling from each sex breeder, 10 egg samples, 5-day-old larvae (n = 20), 20-day-old larvae (n = 80) and fingerling of A. persicus (n = 60) released in earthen ponds were done. After the bioassay and preparing wet mount from the internal and external organs, identification was done according to the keys. According to the results, no fauna parasites were isolated from egg samples and 5-day-old larvae; but Trichodina spp. was isolated from 20-day-old larvae. Also, the same protozoan was isolated from fingerling released in earthen ponds, the mean intensity, prevalence and range of contamination by fingerling were higher with compared to 20-day-old larvae. Trichodina sp. and Diplostomum spathaceum were isolated from skin and eyes of females, respectively. However, Trichodina sp. and Ichthyophthirius multifiliis were isolated from skin of male breeders. In this study, no parasites were isolated from internal organs of larves and fingerling but four intestinal parasites included: Cucullanus sphaerocephlaus, Anisakis sp., Skyrjabinopsilus semiarmatus, and Lepto-rhynchoides plagicephalu were isolated from internal organs of breeder. Based on a wide range of parasitic infection observed in various life stages of A. persicus, it seems necessary to consider hygienic and management measures.

  13. Hybridization, natural selection, and evolution of reproductive isolation: a 25-years survey of an artificial sympatric area between two mosquito sibling species of the Aedes mariae complex.

    PubMed

    Urbanelli, Sandra; Porretta, Daniele; Mastrantonio, Valentina; Bellini, Romeo; Pieraccini, Giuseppe; Romoli, Riccardo; Crasta, Graziano; Nascetti, Giuseppe

    2014-10-01

    Natural selection can act against maladaptive hybridization between co-occurring divergent populations leading to evolution of reproductive isolation among them. A critical unanswered question about this process that provides a basis for the theory of speciation by reinforcement, is whether natural selection can cause hybridization rates to evolve to zero. Here, we investigated this issue in two sibling mosquitoes species, Aedes mariae and Aedes zammitii, that show postmating reproductive isolation (F1 males sterile) and partial premating isolation (different height of mating swarms) that could be reinforced by natural selection against hybridization. In 1986, we created an artificial sympatric area between the two species and sampled about 20,000 individuals over the following 25 years. Between 1986 and 2011, the composition of mating swarms and the hybridization rate between the two species were investigated across time in the sympatric area. Our results showed that A. mariae and A. zammitii have not completed reproductive isolation since their first contact in the artificial sympatric area. We have discussed the relative role of factors such as time of contact, gene flow, strength of natural selection, and biological mechanisms causing prezygotic isolation to explain the observed results.

  14. ZOONOTIC PARASITES, OUR ENVIROMENT AND CHANGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental changes arising from nature and human activity are affecting patterns for the occurrence and significance of many infectious diseases, including zoonotic parasites, which are those naturally transmitted between domestic animals or wildlife and people. As these changes continue, and pe...

  15. Methanomicrobium antiquum sp. nov., a hydrogenotrophic methanogen isolated from deep sedimentary aquifers in a natural gas field.

    PubMed

    Mochimaru, Hanako; Tamaki, Hideyuki; Katayama, Taiki; Imachi, Hiroyuki; Sakata, Susumu; Kamagata, Yoichi

    2016-11-01

    A mesophilic, hydrogenotrophic methanogen, designated strain MobHT, was isolated from sediments derived from deep sedimentary, natural-gas-bearing aquifers in Japan. Strain MobHT utilized H2/CO2 or formate, but not ethanol, 1-propanol, 2-propanol, 2-butanol or cyclopentanol, for growth and methane production. In addition, acetate and tungsten were required for growth. Yeast extract stimulated the growth, but was not required. The cells were weakly motile with multiple flagella, presented as a curved-rod-shaped (0.8×2.0 µm) and occurred singly or in pairs. Strain MobHT grew at 15-40 °C (optimum 35 °C) and at pH 5.9-7.9 (optimum pH 7.0-7.5). The sodium chloride range for growth was 0-5.8 % (optimum 2 %). The G+C content of the genomic DNA was 37.6 mol%. In the phylogenetic tree based on the 16S rRNA gene sequences, strain MobHT clustered together with Methanomicrobium mobile (95.4 % in sequence similarity), and formed a distinct clade from Methanolacinia petrolearia SEBR 4847T (95.6 %) and Methanolacinia paynteri G-2000T (95.4 %). The two species of the genus Methanolacinia utilized 2-propanol, whereas strain MobHT and Methanomicrobium mobile, the sole species of the genus Methanomicrobium, do not. Based on phenotypic and phylogenetic features, we propose a novel species for the isolate with the name, Methanomicrobiumantiquum sp. nov. The type strain is MobHT (=DSM 21220T=NBRC 104160T).

  16. Acerogenin A, a natural compound isolated from Acer nikoense Maxim, stimulates osteoblast differentiation through bone morphogenetic protein action

    SciTech Connect

    Kihara, Tasuku; Ichikawa, Saki; Yonezawa, Takayuki; Lee, Ji-Won; Akihisa, Toshihiro; Woo, Je Tae; Michi, Yasuyuki; Amagasa, Teruo; Yamaguchi, Akira

    2011-03-11

    Research highlights: {yields} Acerogenin A stimulated osteoblast differentiation in osteogenic cells. {yields} Acerogenin A-induced osteoblast differentiation was inhibited by noggin. {yields} Acerogenin A increased Bmp-2, Bmp-4 and Bmp-7 mRNA expression in MC3T3-E1 cells. {yields} Acerogenin A is a candidate agent for stimulating bone formation. -- Abstract: We investigated the effects of acerogenin A, a natural compound isolated from Acer nikoense Maxim, on osteoblast differentiation by using osteoblastic cells. Acerogenin A stimulated the cell proliferation of MC3T3-E1 osteoblastic cells and RD-C6 osteoblastic cells (Runx2-deficient cell line). It also increased alkaline phosphatase activity in MC3T3-E1 and RD-C6 cells and calvarial osteoblastic cells isolated from the calvariae of newborn mice. Acerogenin A also increased the expression of mRNAs related to osteoblast differentiation, including Osteocalcin, Osterix and Runx2 in MC3T3-E1 cells and primary osteoblasts: it also stimulated Osteocalcin and Osterix mRNA expression in RD-C6 cells. The acerogenin A treatment for 3 days increased Bmp-2, Bmp-4, and Bmp-7 mRNA expression levels in MC3T3-E1 cells. Adding noggin, a BMP specific-antagonist, inhibited the acerogenin A-induced increase in the Osteocalcin, Osterix and Runx2 mRNA expression levels. These results indicated that acerogenin A stimulates osteoblast differentiation through BMP action, which is mediated by Runx2-dependent and Runx2-independent pathways.

  17. Influence of enrichment and isolation media on the detection of Campylobacter spp. in naturally contaminated chicken samples.

    PubMed

    Repérant, E; Laisney, M J; Nagard, B; Quesne, S; Rouxel, S; Le Gall, F; Chemaly, M; Denis, M

    2016-09-01

    Investigating Campylobacter epidemiology requires adequate technique and media to ensure optimal culturing and accurate detection and isolation of Campylobacter strains. In the present study, we investigated the performances of three enrichment durations in Bolton broth (0, 24 and 48h) and compared four isolation media (mCCDA, Karmali, Butzler no. 2 and CampyFood agar (CFA)) for the detection of Campylobacter positive samples and the identification of Campylobacter species, from naturally contaminated broiler chicken samples (caeca, neck skin from carcasses, and skin from thighs). We compared our local results to those we obtained with samples from a European survey (caeca and neck skin) and a national survey (neck skin, thigh skin, and breast). Direct plating favored the detection of positive samples highly contaminated by Campylobacter (caeca and neck skin from carcasses) whatever the media. A longer enrichment reduced the rates of Campylobacter recovery except when using Butzler no. 2, more particularly for neck skin which background microflora was less important than in caeca. As a matter of fact, enrichment allowed a higher detection rate of positive samples with low Campylobacter contamination levels (breast, thigh skin), this detection being enhanced when using Butzler no. 2. When comparing the 3 other selective media, CFA was the 2nd most efficient media prior to mCCDA and Karmali. Interestingly, enrichment promoted the growth of Campylobacter coli but this promotion was least with Butzler no. 2 agar. Our study has confirmed the need to adapt the method to the types of samples for improving the detection of Campylobacter and that the method may affect the prevalence of the species.

  18. Host plant species affects virulence in monarch butterfly parasites.

    PubMed

    de Roode, Jacobus C; Pedersen, Amy B; Hunter, Mark D; Altizer, Sonia

    2008-01-01

    1. Studies have considered how intrinsic host and parasite properties determine parasite virulence, but have largely ignored the role of extrinsic ecological factors in its expression. 2. We studied how parasite genotype and host plant species interact to determine virulence of the protozoan parasite Ophryocystis elektroscirrha (McLaughlin & Myers 1970) in the monarch butterfly Danaus plexippus L. We infected monarch larvae with one of four parasite genotypes and reared them on two milkweed species that differed in their levels of cardenolides: toxic chemicals involved in predator defence. 3. Parasite infection, replication and virulence were affected strongly by host plant species. While uninfected monarchs lived equally long on both plant species, infected monarchs suffered a greater reduction in their life spans (55% vs. 30%) on the low-cardenolide vs. the high-cardenolide host plant. These life span differences resulted from different levels of parasite replication in monarchs reared on the two plant species. 4. The virulence rank order of parasite genotypes was unaffected by host plant species, suggesting that host plant species affected parasite genotypes similarly, rather than through complex plant species-parasite genotype interactions. 5. Our results demonstrate that host ecology importantly affects parasite virulence, with implications for host-parasite dynamics in natural populations.

  19. [Culture properties of the causative agent of tularemia isolated in natural foci in Stavropol Territory, the Kalmyk ASSR and the Armenian SSR].

    PubMed

    Basilova, G I; Nekrasov, A A; Pilipenko, V G

    1983-01-01

    The strains isolated in natural foci of the Stavropol Territory and the Armenian SSR have been found to belong to the holarctic race of Francisella tularensis, biovar II. In natural foci of the Kalmyk ASSR the strains belonging to biovars I and II have been isolated. The study of the tularecinogenicity of the cultures has revealed the existence of strains which are not sensitive to their own tularecins. The phenomenon of tularecinogenicity in F. novocida has been established. Avirulent strain 319/38 belonging to the non-arctic race is recommended as an indicator strain for the determination of tularecinogenicity.

  20. Confirmation of the efficacy of a combination tablet of spinosad and milbemycin oxime against naturally acquired infections of canine intestinal nematode parasites.

    PubMed

    Schnitzler, Beate; Hayes, Brad; Wiseman, Scott; Snyder, Daniel E

    2012-03-23

    Four separate controlled and blinded studies were conducted to confirm the dose of spinosad and milbemycin oxime (MO) administered orally in combination to dogs for the treatment and control of naturally acquired infections of adult whipworm (Trichuris vulpis), hookworm (Ancylostoma caninum) and ascarids (Toxocara canis, Toxascaris leonina). Dogs were allocated randomly based on pre-treatment quantitative nematode egg counts of each species of interest to one of two treatment groups of 10 or 11 animals each. In each study, spinosad and MO in combination, was given orally to dogs using the lower half (30-45 mg/kg spinosad; 0.5-0.75 mg/kg MO) of the US commercial dose band (30-60 mg/kg spinosad; 0.5-1.0mg/kg MO) of each active ingredient on Day 0 using a tablet formulation. A corresponding vehicle control group was treated similarly in each individual study. Dogs were necropsied post-treatment on Day 7/8. All nematodes in the intestinal tract collected at necropsy were identified and counted by species and stage. The spinosad and MO combination group demonstrated significantly different adult intestinal nematode efficacy in each individual study as compared to the vehicle control group. Efficacy values for whipworm, hookworm, T. canis and T. leonina were 100%, 99.8%, 100%, 93.3%, respectively. Minor non-serious adverse events were observed in a small number of control and treated dogs that were attributed primarily to the natural nematode infections. In summary, flavored spinosad and MO combination tablets administered orally to dogs were both safe and highly efficacious delivering >93% up to 100% adult intestinal nematode control in naturally infected dogs.

  1. Evolution of premating reproductive isolation among conspecific populations of the sea rock-pool beetle Ochthebius urbanelliae driven by reinforcing natural selection.

    PubMed

    Porretta, Daniele; Urbanelli, Sandra

    2012-04-01

    How natural selection might be involved in speciation remains a fundamental question in evolutionary biology. When two or more species co-occur in the same areas, natural selection may favor divergence in mating traits. By acting in sympatric but not allopatric populations, natural selection can also affect mate choice within species and ultimately initiate speciation among conspecific populations. Here, we address this potential effect in the sea rock-pool beetles Ochthebius quadricollis and O. urbanelliae. The two species, which inhabit the Mediterranean coasts, co-occurr syntopically in an area along the Italian Tyrrhenian coast and completed reproductive isolation by reinforcement. In this article, through mating trials under laboratory conditions between conspecific populations, we found in O. quadricollis no deviations from random mating. Conversely, in O. urbanelliae, we found a clear pattern of premating isolation between the reinforced populations sympatric with O. quadricollis and those nonreinforced allopatric. This pattern is consistent with the view that natural selection, which completed the reproductive isolation between the two species in sympatry, led incidentally also to partial premating reproductive isolation (I(PSI) estimator from 0.683 to 0.792) between conspecific populations of O. urbanelliae. This case study supports an until recently underappreciated role of natural selection resulting from species interactions in initiating speciation.

  2. The Interplay of Host Microbiota and Parasitic Protozoans at Mucosal Interfaces: Implications for the Outcomes of Infections and Diseases

    PubMed Central

    Pinheiro, Jully; Simoes-Barbosa, Augusto

    2015-01-01

    Infections by parasitic protozoans are largely neglected, despite threatening millions of people, particularly in developing countries. With descriptions of the microbiota in humans, a new frontier of investigation is developing to decipher the complexity of host–parasite–microbiota relationships, instead of the classic reductionist approach, which considers host–parasite in isolation. Here, we review with specific examples the potential roles that the resident microbiota can play at mucosal interfaces in the transmission of parasitic protozoans and in the progress of infection and disease. Although the mechanisms underlying these relationships remain poorly understood, some examples provide compelling evidence that specific components of the microbiota can potentially alter the outcomes of parasitic infections and diseases in humans. Most findings suggest a protective role of the microbiota, which might lead to exploratory research comprising microbiota-based interventions to prevent and treat protozoal infections in the future. However, these infections are often accompanied by an unbalanced microbiota and, in some specific cases, apparently, these bacteria may contribute synergistically to disease progression. Taken together, these findings provide a different perspective on the ecological nature of protozoal infections. This review focuses attention on the importance of considering polymicrobial associations, i.e., parasitic protozoans and the host microbiota, for understanding these human infections in their natural microbial context. PMID:26658061

  3. Evaluation of Eimeria krijgsmanni as a murine model for testing the efficacy of anti-parasitic agents.

    PubMed

    Takeo, Toshinori; Tanaka, Tetsuya; Matsubayashi, Makoto; Tsujio, Masashi; Umemiya-Shirafuji, Rika; Tsuji, Naotoshi; Fujisaki, Kozo; Matsui, Toshihiro; Matsuo, Tomohide

    2015-06-01

    Murine Eimeria spp. have been used as effective models of disease instead of large mammalian hosts such as cattle. We attempted to establish in vivo and in vitro assays using a murine intestinal protozoan, Eimeria krijgsmanni, which we previously isolated, to test anti-parasitic agents. Consequently, when mice were treated with sulfur drugs or toltrazuril, which are commercially available for livestock. Furthermore, sporulated oocysts and excysted sporozoites of E. krijgsmanni were treated with naturally occurring substances (lactoferrin, longicin, and curcumin). Although exposure to these substances did not affect oocyst infectivity, sporozoite viability decreased by 60% with longicin. However, direct injection of sporozoites treated with longicin into mice ceca did not result in any changes in the oocyst shedding pattern compared with control mice. The results suggest that E. krijgsmanni could be resistant to these anti-parasitic agents and might therefore have different characteristics to other apicomplexan parasites.

  4. New insights on the genetic diversity of the honeybee parasite Nosema ceranae based on multilocus sequence analysis.

    PubMed

    Roudel, Mathieu; Aufauvre, Julie; Corbara, Bruno; Delbac, Frederic; Blot, Nicolas

    2013-09-01

    The microsporidian parasite Nosema ceranae is a common pathogen of the Western honeybee (Apis mellifera) whose variable virulence could be related to its genetic polymorphism and/or its polyphenism responding to environmental cues. Since the genotyping of N. ceranae based on unique marker sequences had been unsuccessful, we tested whether a multilocus approach, assessing the diversity of ten genetic markers – encoding nine proteins and the small ribosomal RNA subunit – allowed the discrimination between N. ceranae variants isolated from single A. mellifera individuals in four distant locations. High nucleotide diversity and allele content were observed for all genes. Most importantly, the diversity was mainly present within parasite populations isolated from single honeybee individuals. In contrast the absence of isolate differentiation precluded any taxa discrimination, even through a multilocus approach, but suggested that similar populations of parasites seem to infect honeybees in distant locations. As statistical evolutionary analyses showed that the allele frequency is under selective pressure, we discuss the origin and consequences of N. ceranae heterozygosity in a single host and lack of population divergence in the context of the parasite natural and evolutionary history.

  5. Sphingolipids in parasitic protozoa

    PubMed Central

    Zhang, Kai; Bangs, James D.; Beverley, Stephen M.

    2009-01-01

    The surface of most protozoan parasites relies heavily upon lipid-anchored molecules, to form protective barriers and play critical functions required for infectivity. Sphingolipids (SLs) play important roles through their abundance and involvement in membrane microdomain formation, as well as serving as the lipid anchor for many of these molecules, and in some but possibly not all species, as important signaling molecules. Interactions of parasite sphingolipid metabolism with that of the host may potentially contribute to parasite survival and/or host defense. In this chapter we summarize current knowledge of SL structure, synthesis and function in several of the major parasitic protozoan groups. PMID:20919659

  6. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  7. Synthesis and electrochemical detection of a thiazolyl-indole natural product isolated from the nosocomial pathogen Pseudomonas aeruginosa.

    PubMed

    Buzid, Alyah; Muimhneacháin, Eoin Ó; Reen, F Jerry; Hayes, Phyllis E; Pardo, Leticia M; Shang, Fengjun; O'Gara, Fergal; Sperry, Jonathan; Luong, John H T; Glennon, Jeremy D; McGlacken, Gerard P

    2016-09-01

    Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen, capable of surviving in a broad range of natural environments and quickly acquiring resistance. It is associated with hospital-acquired infections, particularly in patients with compromised immunity, and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. P. aeruginosa is also of nosocomial importance on dairy farms and veterinary hospitals, where it is a key morbidity factor in bovine mastitis. P. aeruginosa uses a cell-cell communication system consisting of signalling molecules to coordinate bacterial secondary metabolites, biofilm formation, and virulence. Simple and sensitive methods for the detection of biomolecules as indicators of P. aeruginosa infection would be of great clinical importance. Here, we report the synthesis of the P. aeruginosa natural product, barakacin, which was recently isolated from the bovine ruminal strain ZIO. A simple and sensitive electrochemical method was used for barakacin detection using a boron-doped diamond (BDD) and glassy carbon (GC) electrodes, based on cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The influence of electrolyte pH on the peak potential and peak currents was also investigated. At pH 2.0, the peak current was linearly dependent on barakacin concentration (in the range used, 1-10 μM), with correlation coefficients greater than 0.98 on both electrodes. The detection limit (S/N = 3) on the BDD electrode was 100-fold lower than that obtained on the GC electrode. The optimized method using the BDD electrode was extended to bovine (cow feces) and human (sputum of a CF patient) samples. Spiked barakacin was easily detected in these matrices at a limit of 0.5 and 0.05 μM, respectively. Graphical abstract Electrochemical detection of barakacin.

  8. Comparative genomics among Saccharomyces cerevisiae × Saccharomyces kudriavzevii natural hybrid strains isolated from wine and beer reveals different origins

    PubMed Central

    2012-01-01

    Background Interspecific hybrids between S. cerevisiae × S. kudriavzevii have frequently been detected in wine and beer fermentations. Significant physiological differences among parental and hybrid strains under different stress conditions have been evidenced. In this study, we used comparative genome hybridization analysis to evaluate the genome composition of different S. cerevisiae × S. kudriavzevii natural hybrids isolated from wine and beer fermentations to infer their evolutionary origins and to figure out the potential role of common S. kudriavzevii gene fraction present in these hybrids. Results Comparative genomic hybridization (CGH) and ploidy analyses carried out in this study confirmed the presence of individual and differential chromosomal composition patterns for most S. cerevisiae × S. kudriavzevii hybrids from beer and wine. All hybrids share a common set of depleted S. cerevisiae genes, which also are depleted or absent in the wine strains studied so far, and the presence a common set of S. kudriavzevii genes, which may be associated with their capability to grow at low temperatures. Finally, a maximum parsimony analysis of chromosomal rearrangement events, occurred in the hybrid genomes, indicated the presence of two main groups of wine hybrids and different divergent lineages of brewing strains. Conclusion Our data suggest that wine and beer S. cerevisiae × S. kudriavzevii hybrids have been originated by different rare-mating events involving a diploid wine S. cerevisiae and a haploid or diploid European S. kudriavzevii strains. Hybrids maintain several S. kudriavzevii genes involved in cold adaptation as well as those related to S. kudriavzevii mitochondrial functions. PMID:22906207

  9. Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan

    PubMed Central

    Shangpliang, H. N. J.; Sharma, Sharmila; Rai, Ranjita; Tamang, Jyoti P.

    2017-01-01

    Dahi and datshi are common naturally fermented milk (NFM) products of Bhutan. Population of lactic acid bacteria (LAB) in dahi (pH 3.7) and datshi (pH 5.2) was 1.4 × 107 and 3.9 × 108 cfu/ml, respectively. Based on 16S rRNA gene sequencing isolates of LAB from dahi and datshi were identified as Enterococcus faecalis, E. faecium, Lactococcus lactis subsp. lactis. LAB strains were tested for some technological properties. All LAB strains except E. faecalis CH2:17 caused coagulation of milk at both 30°C for 48 h. Only E. faecium DH4:05 strain was resistant to pH 3. No significant difference (P > 0.05) of viable counts was observed in MRS broth with and without lysozyme. All LAB strains grew well in 0.3% bile showing their ability to tolerate bile salt. None of the LAB strains showed >70% hydrophobicity. This study, being the first of its microbiological analysis of the NFM of Bhutan, has opened up to an extent of research work that gives a new insight to the products. PMID:28203227

  10. Improvement of interfacial interactions using natural polyphenol-inspired tannic acid-coated nanoclay enhancement of soy protein isolate biofilms

    NASA Astrophysics Data System (ADS)

    Wang, Zhong; Kang, Haijiao; Zhang, Wei; Zhang, Shifeng; Li, Jianzhang

    2017-04-01

    In this study, a novel and economic surface modification technique for montmorillonite (MMT) nanosheets, a biocompatible coupling cross-linking agent, was developed on an attempt at improving the interfacial adhesion with soy protein isolate (SPI) matrix. Inspired by natural polyphenol, the "green dip-coating" method using tannic acid (TA) to surface-modify MMT (TA@MMT). SPI nanocomposite films modified with MMT or TA@MMT, as well as the control ones, were prepared via the casting method. The TA layer was successfully coated on the MMT surface through the (FeIII) ions coordination chemistry and the synthetic samples were characterized by the Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The compatibility and interfacial interactions between modified MMT and SPI matrix were greatly enhanced by the TA-FeIII coating on the MMT surface. The mechanical properties, water resistance, and thermal stability of the resultant biofilm were increased accordingly. Compared with that of the unmodified SPI film, the tensile strength of the nanocomposite films modified by the green dip-coating was increased by 113.3%. These SPI-based nanocomposite films showed the favorable potential in terms of food packing applications due to their efficient barriers to water vapor and UV and/or visible light.

  11. Isolation of natural red colorants from fermented broth using ionic liquid-based aqueous two-phase systems.

    PubMed

    Ventura, Sónia P M; Santos-Ebinuma, Valéria C; Pereira, Jorge F B; Teixeira, Maria F S; Pessoa, Adalberto; Coutinho, João A P

    2013-05-01

    There is a growing demand for natural colorants. This is prompting the search for new alternative and "benign" separation systems allowing higher recoveries, extraction yields, and selectivities. This work investigates the use of aqueous two-phase systems (ATPS) based on ionic liquids as extraction processes for the recovery of red colorants from the fermented broth of Penicillium purpurogenum DPUA 1275. Several ATPS based on quaternary ammonium and imidazolium were studied in this work aiming at separating the red colorants produced from the remaining colorants and contaminant proteins present in the fermented broth. The results suggest that the red colorants can be isolated by an appropriate manipulation of some of the process conditions, such as the use of quaternary ammonium with short alkyl chains, alkaline media, and short tie-line lengths (extraction point systems with lower concentrations of ionic liquid). These conditions allow large partition coefficients for the red colorants (K red = 24.4 ± 2.3), high protein removal (60.7 ± 2.8 %) and selectivity parameters (S red/prot = 10.05).

  12. Eaten alive: cannibalism is enhanced by parasites

    PubMed Central

    Bunke, Mandy; Alexander, Mhairi E.; Dick, Jaimie T. A.; Hatcher, Melanie J.; Paterson, Rachel; Dunn, Alison M.

    2015-01-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use. PMID:26064614

  13. Eaten alive: cannibalism is enhanced by parasites.

    PubMed

    Bunke, Mandy; Alexander, Mhairi E; Dick, Jaimie T A; Hatcher, Melanie J; Paterson, Rachel; Dunn, Alison M

    2015-03-01

    Cannibalism is ubiquitous in nature and especially pervasive in consumers with stage-specific resource utilization in resource-limited environments. Cannibalism is thus influential in the structure and functioning of biological communities. Parasites are also pervasive in nature and, we hypothesize, might affect cannibalism since infection can alter host foraging behaviour. We investigated the effects of a common parasite, the microsporidian Pleistophora mulleri, on the cannibalism rate of its host, the freshwater amphipod Gammarus duebeni celticus. Parasitic infection increased the rate of cannibalism by adults towards uninfected juvenile conspecifics, as measured by adult functional responses, that is, the rate of resource uptake as a function of resource density. This may reflect the increased metabolic requirements of the host as driven by the parasite. Furthermore, when presented with a choice, uninfected adults preferred to cannibalize uninfected rather than infected juvenile conspecifics, probably reflecting selection pressure to avoid the risk of parasite acquisition. By contrast, infected adults were indiscriminate with respect to infection status of their victims, probably owing to metabolic costs of infection and the lack of risk as the cannibals were already infected. Thus parasitism, by enhancing cannibalism rates, may have previously unrecognized effects on stage structure and population dynamics for cannibalistic species and may also act as a selective pressure leading to changes in resource use.

  14. Diversity increases biomass production for trematode parasites in snails

    USGS Publications Warehouse

    Hechinger, Ryan F.; Lafferty, Kevin D.; Kuris, Armand M.

    2008-01-01

    Increasing species diversity typically increases biomass in experimental assemblages. But there is uncertainty concerning the mechanisms of diversity effects and whether experimental findings are relevant to ecological process in nature. Hosts for parasites provide natural, discrete replicates of parasite assemblages. We considered how diversity affects standing-stock biomass for a highly interactive parasite guild: trematode parasitic castrators in snails. In 185 naturally occurring habitat replicates (individual hosts), diverse parasite assemblages had greater biomass than single-species assemblages, including those of their most productive species. Additionally, positive diversity effects strengthened as species segregated along a secondary niche axis (space). The most subordinate species—also the most productive when alone—altered the general positive effect, and was associated with negative diversity effects on biomass. These findings, on a previously unstudied consumer class, extend previous research to illustrate that functional diversity and species identity may generally both explain how diversity influences biomass production in natural assemblages of competing species.

  15. Natural products isolated from Mexican medicinal plants: novel inhibitors of sulfotransferases, SULT1A1 and SULT2A1.

    PubMed

    Mesía-Vela, S; Sańchez, R I; Estrada-Muñiz, E; Alavez-Solano, D; Torres-Sosa, C; Jiménez, M; Estrada; Reyes-Chilpa, R; Kauffman, F C

    2001-11-01

    Calophyllum brasiliense, Lonchocarpus oaxacensis, and Lonchocarpus guatemalensis are used in Latin American folk medicine. Four natural xanthones, an acetylated derivative, and two coumarins were obtained from C. brasiliense. Two flavanones were extracted from L. oaxacensis and one chalcone from L guatemalensis. These compounds were tested as substrates and inhibitors for two recombinant sulfotransferases (SULTs) involved in the metabolism of many endogenous compounds and foreign chemicals. Assays were performed using recombinant phenolsulfotransferase (SULT1A1) and hydroxysteroidsulfotransferase (SULT2A1). Three of the five xanthones, one of the flavonoids and the coumarins tested were substrates for SULT1A1. None of the xanthones or the flavonoids were sulfonated by SULT2A1, whereas the coumarin mammea A/BA was a substrate for this enzyme. The natural xanthones reversibly inhibited SULT1A1 with IC50 values ranging from 1.6 to 7 microM whereas much higher amounts of these compounds were required to inhibit SULT2A1 (IC50 values of 26-204 microM). The flavonoids inhibited SULT1A1 with IC50 values ranging from 9.5 to 101 microM, which compared with amounts needed to inhibit SULT2A1 (IC50 values of 11 to 101 microM). Both coumarins inhibited SULT1A1 with IC50 values of 47 and 185 pM, and SULT2A1 with IC50 values of 16 and 31 microM. The acetylated xanthone did not inhibit either SULT1AI or SULT2A1 activity. Rotenone from a commercial source had potency comparable to that of the flavonoids isolated from Lonchocarpus for inhibiting both SULTs. The potency of this inhibition depends on the position and number of hydroxyls. The results indicate that SULT1A1, but not SULT2A1, is highly sensitive to inhibition by xanthones. Conversely, SULT2A1 is 3-6 times more sensitive to coumarins than SULT1A1. The flavonoids are non-specific inhibitors of the two SULTs. Collectively, the results suggest that these types of natural products have the potential for important

  16. Identification of naturally isolated southern Louisiana's algal strains and the effect of higher Co2 content on fatty acid profiles for biodiesel production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four naturally isolated microalgae were evaluated for their potential use in the production of biodiesel, and were identified using genomic DNA, and 16S or 18S rRNA gene amplification followed by sequencing. High correlation was found with known nucleotide sequence identities at 98 % with Sellaphora...

  17. Draft Genome Sequence of the Beneficial Rhizobacterium Pseudomonas fluorescens DSM 8569, a Natural Isolate of Oilseed Rape (Brassica napus)

    PubMed Central

    Nesemann, Kai; Braus-Stromeyer, Susanna A.; Thuermer, Andrea; Daniel, Rolf

    2015-01-01

    Pseudomonas fluorescens DSM 8569 represents a natural isolate of the rhizosphere of oilseed rape (Brassica napus) in Germany and possesses antagonistic potential toward the fungal pathogen Verticillium. We report here the draft genome sequence of strain DSM 8569, which comprises 5,914 protein-coding sequences. PMID:25814596

  18. Introducing Organic Chemistry Students to Natural Product Isolation Using Steam Distillation and Liquid Phase Extraction of Thymol, Camphor, and Citral, Monoterpenes Sharing a Unified Biosynthetic Precursor

    ERIC Educational Resources Information Center

    McLain, Katherine A.; Miller, Kenneth A.; Collins, William R.

    2015-01-01

    Plants have provided and continue to provide the inspiration and foundation for modern medicines. Natural product isolation is a key component of the process of drug discovery from plants. The purpose of this experiment is to introduce first semester undergraduate organic chemistry students, who have relatively few lab techniques at their…

  19. The complete genome sequence and annotation of a Campylobacter jejuni strain, MTVDSCj20, isolated from a naturally colonized farm-raised chicken

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter jejuni is a major cause of human foodborne illness worldwide with contaminated poultry products serving as a main source of human infection. C. jejuni strain MTVDSCj20 was isolated from the cecal contents of a farm-raised chicken naturally colonized with Campylobacter. The complete,...

  20. Highly rearranged mitochondrial genome in Nycteria parasites (Haemosporidia) from bats

    PubMed Central

    Karadjian, Gregory; Hassanin, Alexandre; Saintpierre, Benjamin; Gembu Tungaluna, Guy-Crispin; Ariey, Frederic; Ayala, Francisco J.; Landau, Irene; Duval, Linda

    2016-01-01

    Haemosporidia parasites have mostly and abundantly been described using mitochondrial genes, and in particular cytochrome b (cytb). Failure to amplify the mitochondrial cytb gene of Nycteria parasites isolated from Nycteridae bats has been recently reported. Bats are hosts to a diverse and profuse array of Haemosporidia parasites that remain largely unstudied. There is a need to obtain more molecular data from chiropteran parasites. Such data would help to better understand the evolutionary history of Haemosporidia, which notably include the Plasmodium parasites, malaria’s agents. We use next-generation sequencing to obtain the complete mitochondrial genome of Nycteria parasites from African Nycteris grandis (Nycteridae) and Rhinolophus alcyone (Rhinolophidae) and Asian Megaderma spasma (Megadermatidae). We report four complete mitochondrial genomes, including two rearranged mitochondrial genomes within Haemosporidia. Our results open outlooks into potentially undiscovered Haemosporidian diversity. PMID:27528689

  1. Host-parasite interactions that guide red blood cell invasion by malaria parasites

    PubMed Central

    Paul, Aditya S.; Egan, Elizabeth S.; Duraisingh, Manoj T.

    2015-01-01

    Purpose of Review Malaria is caused by the infection and proliferation of parasites from the genus Plasmodium in red blood cells (RBCs). A free Plasmodium parasite, or merozoite, released from an infected RBC must invade another RBC host cell to sustain a blood-stage infection. Here, we review recent advances on RBC invasion by Plasmodium merozoites, focusing on specific molecular interactions between host and parasite. Recent findings Recent work highlights the central role of host-parasite interactions at virtually every stage of RBC invasion by merozoites. Biophysical experiments have for the first time measured the strength of merozoite-RBC attachment during invasion. For P. falciparum, there have been many key insights regarding the invasion ligand PfRh5 in particular, including its influence on host species tropism, a co-crystal structure with its RBC receptor basigin, and its suitability as a vaccine target. For P. vivax, researchers identified the origin and emergence of the parasite from Africa, demonstrating a natural link to the Duffy-negative RBC variant in African populations. For the simian parasite P. knowlesi, zoonotic invasion into human cells is linked to RBC age, which has implications for parasitemia during an infection and thus malaria. Summary New studies of the molecular and cellular mechanisms governing RBC invasion by Plasmodium parasites have shed light on various aspects of parasite biology and host cell tropism; and indicate opportunities for malaria control. PMID:25767956

  2. Secondary metabolites isolation in natural products chemistry: comparison of two semipreparative chromatographic techniques (high pressure liquid chromatography and high performance thin-layer chromatography).

    PubMed

    Do, Thi Kieu Tiên; Hadji-Minaglou, Francis; Antoniotti, Sylvain; Fernandez, Xavier

    2014-01-17

    Chemical investigations on secondary metabolites in natural products chemistry require efficient isolation techniques for characterization purpose as well as for the evaluation of their biological properties. In the case of phytochemical studies, the performance of the techniques is critical (resolution and yield) since the products generally present a narrow range of polarity and physicochemical properties. Several techniques are currently available, but HPLC (preparative and semipreparative) is the most widely used. To compare the performance of semipreparative HPLC and HPTLC for the isolation of secondary metabolites in different types of extracts, we have chosen carvone from spearmint essential oil (Mentha spicata L.), resveratrol from Fallopia multiflora (Thunb.) Haraldson, and rosmarinic acid from rosemary (Rosmarinus officinalis L.) extracts. The comparison was based on the chromatographic separation, the purity and quantity of isolated compounds, the solvent consumption, the duration and the cost of the isolation operations. The results showed that semipreparative HPTLC can in some case offer some advantages over conventional semipreparative HPLC.

  3. PARASITES OF FISH

    EPA Science Inventory

    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...

  4. Postcolonial Ecologies of Parasite and Host: Making Parasitism Cosmopolitan.

    PubMed

    Anderson, Warwick

    2016-04-01

    The interest of F. Macfarlane Burnet in host-parasite interactions grew through the 1920s and 1930s, culminating in his book, Biological Aspects of Infectious Disease (1940), often regarded as the founding text of disease ecology. Our knowledge of the influences on Burnet's ecological thinking is still incomplete. Burnet later attributed much of his conceptual development to his reading of British theoretical biology, especially the work of Julian Huxley and Charles Elton, and regretted he did not study Theobald Smith's Parasitism and Disease (1934) until after he had formulated his ideas. Scholars also have adduced Burnet's fascination with natural history and the clinical and public health demands on his research effort, among other influences. I want to consider here additional contributions to Burnet's ecological thinking, focusing on his intellectual milieu, placing his research in a settler society with exceptional expertise in environmental studies and pest management. In part, an ''ecological turn'' in Australian science in the 1930s, derived to a degree from British colonial scientific investments, shaped Burnet's conceptual development. This raises the question of whether we might characterize, in postcolonial fashion, disease ecology, and other studies of parasitism, as successful settler colonial or dominion science.

  5. Life history strategy influences parasite responses to habitat fragmentation.

    PubMed

    Froeschke, Götz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja

    2013-12-01

    Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission.

  6. Humibacter antri sp. nov., an actinobacterium isolated from a natural cave, and emended description of the genus Humibacter.

    PubMed

    Lee, Soon Dong

    2013-11-01

    A novel high DNA G+C content bacterium, designated strain D7-27(T), was isolated from clay soils collected inside a natural cave in Jeju, Republic of Korea. The cells of the organism were aerobic, Gram-stain-positive, non-motile rods; its colonies were white, circular and entire in margin. Phylogenetic analyses based on 16S rRNA gene sequence comparison showed that strain D7-27(T) formed a coherent cluster with Humibacter albus of the family Microbacteriaceae (97.6 % sequence similarity). The cell-wall peptidoglycan contained ornithine and 2,4-diaminobutyric acid as the diagnostic diamino acids. The major menaquinones were MK-12 and MK-11, with MK-10 as a minor component. The polar lipids consisted mainly of phosphatidylglycerol and an unknown glycolipid. Mycolic acids were not present. The predominant fatty acids were anteiso-C17 : 0 and cyclohexyl-C17 : 0. The DNA G+C content was 66.3 mol%. DNA-DNA relatedness between strain D7-27(T) and H. albus DSM 18994(T) was 28.6 % (17.6 % in a reciprocal test). On the basis of the phenotypic, chemotaxonomic and DNA-DNA hybridization data, strain D7-27(T) ( = KCTC 33009(T) = DSM 25738(T)) is considered as the type strain of a novel species of the genus Humibacter, for which the name Humibacter antri sp. nov. is proposed. An emended description of the genus Humibacter is also provided.

  7. Sequencing of two sunflower chlorotic mottle virus isolates obtained from different natural hosts shed light on its evolutionary history.

    PubMed

    Bejerman, N; Giolitti, F; de Breuil, S; Lenardon, S

    2013-02-01

    Sunflower chlorotic mottle virus (SuCMoV), the most prevalent virus of sunflower in Argentina, was reported naturally infecting not only sunflower but also weeds. To understand SuCMoV evolution and improve the knowledge on its variability, the complete genomic sequences of two SuCMoV isolates collected from Dipsacus fullonum (-dip) and Ibicella lutea (-ibi) were determined from three overlapping cDNA clones and subjected to phylogenetic and recombination analyses. SuCMoV-dip and -ibi genomes were 9,953-nucleotides (nt) long; their sequences contained an open reading frame of 9,561 nucleotides, which encoded a polyprotein of 3,187 amino acids flanked by a 5'-noncoding region (NCR) of 135 nt and a 3'-NCR of 257 nt. SuCMoV-dip and -ibi genome nucleotide sequences were 90.9 identical and displayed 90 and 94.6 % identity to that of SuCMoV-C, and 90.8 and 91.4 % identity to that of SuCMoV-CRS, respectively. P1 of SuCMoV-dip and -ibi was 3-nt longer than that of SuCMoV-CRS, but 12-nt shorter than that of SuCMoV-C. Two recombination events were detected in SuCMoV genome and the analysis of d(N)/d(S) ratio among SuCMoV complete sequences showed that the genomic regions are under different evolutionary constraints, suggesting that SuCMoV evolution would be conservative. Our findings provide evidence that mutation and recombination would have played important roles in the evolutionary history of SuCMoV.

  8. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.

    PubMed

    Fragkiadaki, Eirini G; Vaccari, Gabriele; Ekateriniadou, Loukia V; Agrimi, Umberto; Giadinis, Nektarios D; Chiappini, Barbara; Esposito, Elena; Conte, Michela; Nonno, Romolo

    2011-09-30

    One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

  9. Fauna Europaea: Helminths (Animal Parasitic)

    PubMed Central

    Bray, Rodney A.; Hunt, David; Georgiev, Boyko B.; Scholz, Tomaš; Harris, Philip D.; Bakke, Tor A.; Pojmanska, Teresa; Niewiadomska, Katarzyna; Kostadinova, Aneta; Tkach, Vasyl; Bain, Odile; Durette-Desset, Marie-Claude; Gibbons, Lynda; Moravec, František; Petter, Annie; Dimitrova, Zlatka M.; Buchmann, Kurt; Valtonen, E. Tellervo; de Jong, Yde

    2014-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea), Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended. PMID:25349520

  10. Fauna europaea: helminths (animal parasitic).

    PubMed

    Gibson, David I; Bray, Rodney A; Hunt, David; Georgiev, Boyko B; Scholz, Tomaš; Harris, Philip D; Bakke, Tor A; Pojmanska, Teresa; Niewiadomska, Katarzyna; Kostadinova, Aneta; Tkach, Vasyl; Bain, Odile; Durette-Desset, Marie-Claude; Gibbons, Lynda; Moravec, František; Petter, Annie; Dimitrova, Zlatka M; Buchmann, Kurt; Valtonen, E Tellervo; de Jong, Yde

    2014-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea), Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended.

  11. Phylogenetic Diversity of Marine Cyanophage Isolates and Natural Virus Communities as Revealed by Sequences of Viral Capsid Assembly Protein Gene g20†

    PubMed Central

    Zhong, Yan; Chen, Feng; Wilhelm, Steven W.; Poorvin, Leo; Hodson, Robert E.

    2002-01-01

    In order to characterize the genetic diversity and phylogenetic affiliations of marine cyanophage isolates and natural cyanophage assemblages, oligonucleotide primers CPS1 and CPS8 were designed to specifically amplify ca. 592-bp fragments of the gene for viral capsid assembly protein g20. Phylogenetic analysis of isolated cyanophages revealed that the marine cyanophages were highly diverse yet more closely related to each other than to enteric coliphage T4. Genetically related marine cyanophage isolates were widely distributed without significant geographic segregation (i.e., no correlation between genetic variation and geographic distance). Cloning and sequencing analysis of six natural virus concentrates from estuarine and oligotrophic offshore environments revealed nine phylogenetic groups in a total of 114 different g20 homologs, with up to six clusters and 29 genotypes encountered in a single sample. The composition and structure of natural cyanophage communities in the estuary and open-ocean samples were different from each other, with unique phylogenetic clusters found for each environment. Changes in clonal diversity were also observed from the surface waters to the deep chlorophyll maximum layer in the open ocean. Only three clusters contained known cyanophage isolates, while the identities of the other six clusters remain unknown. Whether or not these unidentified groups are composed of bacteriophages that infect different Synechococcus groups or other closely related cyanobacteria remains to be determined. The high genetic diversity of marine cyanophage assemblages revealed by the g20 sequences suggests that marine viruses can potentially play important roles in regulating microbial genetic diversity. PMID:11916671

  12. Distribution of Mycobacterium avium Complex Isolates in Tissue Samples of Pigs Fed Peat Naturally Contaminated with Mycobacteria as a Supplement

    PubMed Central

    Matlova, Ludmila; Dvorska, Lenka; Ayele, Wuhib Yayo; Bartos, Milan; Amemori, Takashi; Pavlik, Ivo

    2005-01-01

    In early 1999, there was an increased incidence of tuberculous lesions in the lymph nodes of slaughtered pigs in the Czech Republic. In part 1 of this study, tuberculous lesions were detected in 140 (62%) tissue samples collected from pigs coming from 15 farms in 15 districts at routine veterinary meat inspections in abattoirs. Mycobacteria were isolated from 37 (16%) tissue samples: 34 Mycobacterium avium subsp. hominissuis isolates and three environmentally derived mycobacteria. In search of infection sources, M. avium subsp. hominissuis was isolated from 38 (79%) samples of peat used as a feed supplement. In part 2 of our study, the head, mesenteric, and inguinal lymph nodes of 117 randomly selected slaughtered pigs from one farm with young piglets fed peat as a supplement were investigated for mycobacterial infection. From 65 (56%) pigs, a total of 76 mycobacterial isolates were identified (56 M. avium subsp. hominissuis isolates, 5 M. avium subsp. avium isolates, 3 M. intracellulare isolates, and 12 environmentally derived mycobacterial isolates). IS1245 restriction fragment length polymorphism (RFLP) types with >20 bands of 45 distinct RFLP types were found in 49 M. avium subsp. hominissuis isolates from pigs (n = 31) and peat (n = 18). Identical RFLP types were found in only four pig isolates. Five randomly selected isolates from pigs and peat were subcultured to six independent clones or colonies. Among the IS1245 RFLP types of 30 clones, identical RFLP types obtained from pigs and peat were identified, which confirmed the hypothesis that peat contaminated with mycobacteria represents a significant source of mycobacterial infection for pigs. PMID:15750094

  13. Peroxiredoxins in Parasites

    PubMed Central

    Gretes, Michael C.; Poole, Leslie B.

    2012-01-01

    Abstract Significance: Parasite survival and virulence relies on effective defenses against reactive oxygen and nitrogen species produced by the host immune system. Peroxiredoxins (Prxs) are ubiquitous enzymes now thought to be central to such defenses and, as such, have potential value as drug targets and vaccine antigens. Recent Advances: Plasmodial and kinetoplastid Prx systems are the most extensively studied, yet remain inadequately understood. For many other parasites our knowledge is even less well developed. Through parasite genome sequencing efforts, however, the key players are being discovered and characterized. Here we describe what is known about the biochemistry, regulation, and cell biology of Prxs in parasitic protozoa, helminths, and fungi. At least one Prx is found in each parasite with a sequenced genome, and a notable theme is the common patterns of expression, localization, and functionality among sequence-similar Prxs in related species. Critical Issues: The nomenclature of Prxs from parasites is in a state of disarray, causing confusion and making comparative inferences difficult. Here we introduce a systematic Prx naming convention that is consistent between organisms and informative about structural and evolutionary relationships. Future Directions: The new nomenclature should stimulate the crossfertilization of ideas among parasitologists and with the broader redox research community. The diverse parasite developmental stages and host environments present complex systems in which to explore the variety of roles played by Prxs, with a view toward parlaying what is learned into novel therapies and vaccines that are urgently needed. Antioxid. Redox Signal. 17, 608–633. PMID:22098136

  14. Reduction of parasitic lasing

    NASA Technical Reports Server (NTRS)

    Storm, Mark E. (Inventor)

    1994-01-01

    A technique was developed which carefully retro-reflects precisely controlled amounts of light back into a laser system thereby intentionally forcing the laser system components to oscillate in a new resonator called the parasitic oscillator. The parasitic oscillator uses the laser system to provide the gain and an external mirror is used to provide the output coupling of the new resonator. Any change of gain or loss inside the new resonator will directly change the lasing threshold of the parasitic oscillator. This change in threshold can be experimentally measured as a change in the absolute value of reflectivity, provided by the external mirror, necessary to achieve lasing in the parasitic oscillator. Discrepancies between experimental data and a parasitic oscillator model are direct evidence of optical misalignment or component performance problems. Any changes in the optical system can instantly be measured as a change in threshold for the parasitic oscillator. This technique also enables aligning the system for maximum parasitic suppression with the system fully operational.

  15. Demonstration of the role of cytophilic antibody in resistance to malaria parasites (Plasmodium berghei) in rats.

    PubMed Central

    Green, T J; Kreier, J P

    1978-01-01

    This paper reports the results of a study of the nature of the immune response against Plasmodium berghei parasites by inbred rats. A macrophage-cytophilic antibody specific for malarial antigens was identified and characterized. Detection of the antibody on the macrophage surface was accomplished by the parasite adherence tests and by the indirect fluorescent antibody technique. Isolation and purification of the macrophage-cytophilic and opsonic antibodies from hyperimmune rat serum was accomplished by QAE-Sephadez A-50 elution chromatography, and of the macrophage-cytophilic antibody by adsorption with and elution from syngeneic macrophages as well. Characterization of the cytophilic antibody as immunoglobulin G1 was done by immunoelectrophoresis and by Ouchterlony-type double diffusion in gel. Passive protection tests in weanling inbred rats have demonstrated that the opsonizing antibody conferred some protection against P. berghei. The macrophage-cytophilic antibody, on the other hand, was not protective alone but acted synergistically with the opsonizing antibody. Images PMID:342408

  16. Bird brood parasitism.

    PubMed

    Stevens, Martin

    2013-10-21

    For many animals, the effort to rear their young is considerable. In birds, this often includes building nests, incubating eggs, feeding the chicks, and protecting them from predators. Perhaps for this reason, about 1% of birds (around 100 species) save themselves the effort and cheat instead. They are obligate brood parasites, laying their eggs in the nests of other species and leaving the hosts or foster parents to rear the foreign chicks for them. Some birds also cheat on individuals of the same species (intraspecific brood parasitism). Intraspecific brood parasitism has been reported in around 200 species, but is likely to be higher, as it can often only be detected by genetic analyses.

  17. [Parasitism and ecological parasitology].

    PubMed

    Balashov, Iu S

    2011-01-01

    Parasitism as one of the life modes is a general biological phenomenon and is a characteristic of all viruses, many taxa of bacteria, fungi, protists, metaphytes, and metazoans. Zooparasitology is focused on studies of parasitic animals, particularly, on their taxonomy, anatomy, life cycles, host-parasite relations, biocoenotic connections, and evolution. Ecological parasitology is a component of ecology, as the scientific study of the relation of living organisms with each other and their surroundings. In the present paper, critical analysis of the problems, main postulates, and terminology of the modern ecological parasitology is given.

  18. A study using demographic data of genetic drift and natural selection in an isolated Mediterranean community: Bayárcal (La Alpujarra, south-east Spain).

    PubMed

    Luna, F; Tarelho, A R; Camargo, A M; Alonso, V

    2011-07-01

    Natural selection and genetic drift are two evolutionary mechanisms that can be analysed in human populations using their fertility and mortality patterns, and their reproductive size and isolation, respectively. This paper analyses the models of natural selection and genetic drift in Bayárcal, south-east Spain, and compares them with the observed models in the rest of the Alpujarran region. Demographic data were obtained from a sample of 77 families (48.45% of the population, with 547 inhabitants). The genetic drift and natural selection action was evaluated with the Coefficient of Breeding Isolation (CBI of Lasker and Kaplan) and Crow's index, respectively. The CBI (23.23/12.61) suggests that genetic drift is near to acting, and Crow's index (I=0.58) is slightly higher than that observed in the rest of La Alpujarra. Although the reproductive isolation of Bayárcal is not effective enough for genetic drift to act, it is near when marital migrants inside the Bayárcal valley are considered as a native population. The natural selection pattern is not different from that of the rest of La Alpujarra, but it tends towards the model of developing communities, where the demographic transition has not yet begun.

  19. Immunological change in a parasite-impoverished environment: divergent signals from four island taxa.

    PubMed

    Beadell, Jon S; Atkins, Colm; Cashion, Erin; Jonker, Michelle; Fleischer, Robert C

    2007-09-19

    Dramatic declines of native Hawaiian avifauna due to the human-mediated emergence of avian malaria and pox prompted an examination of whether island taxa share a common altered immunological signature, potentially driven by reduced genetic diversity and reduced exposure to parasites. We tested this hypothesis by characterizing parasite prevalence, genetic diversity and three measures of immune response in two recently-introduced species (Neochmia temporalis and Zosterops lateralis) and two island endemics (Acrocephalus aequinoctialis and A. rimitarae) and then comparing the results to those observed in closely-related mainland counterparts. The prevalence of blood parasites was significantly lower in 3 of 4 island taxa, due in part to the absence of certain parasite lineages represented in mainland populations. Indices of genetic diversity were unchanged in the island population of N. temporalis; however, allelic richness was significantly lower in the island population of Z. lateralis while both allelic richness and heterozygosity were significantly reduced in the two island-endemic species examined. Although parasite prevalence and genetic diversity generally conformed to expectations for an island system, we did not find evidence for a pattern of uniformly altered immune responses in island taxa, even amongst endemic taxa with the longest residence times. The island population of Z. lateralis exhibited a significantly reduced inflammatory cell-mediated response while levels of natural antibodies remained unchanged for this and the other recently introduced island taxon. In contrast, the island endemic A. rimitarae exhibited a significantly increased inflammatory response as well as higher levels of natural antibodies and complement. These measures were unchanged or lower in A. aequinoctialis. We suggest that small differences in the pathogenic landscape and the stochastic history of mutation and genetic drift are likely to be important in shaping the unique

  20. Immunological Change in a Parasite-Impoverished Environment: Divergent Signals from Four Island Taxa

    PubMed Central

    Beadell, Jon S.; Atkins, Colm; Cashion, Erin; Jonker, Michelle; Fleischer, Robert C.

    2007-01-01

    Dramatic declines of native Hawaiian avifauna due to the human-mediated emergence of avian malaria and pox prompted an examination of whether island taxa share a common altered immunological signature, potentially driven by reduced genetic diversity and reduced exposure to parasites. We tested this hypothesis by characterizing parasite prevalence, genetic diversity and three measures of immune response in two recently-introduced species (Neochmia temporalis and Zosterops lateralis) and two island endemics (Acrocephalus aequinoctialis and A. rimitarae) and then comparing the results to those observed in closely-related mainland counterparts. The prevalence of blood parasites was significantly lower in 3 of 4 island taxa, due in part to the absence of certain parasite lineages represented in mainland populations. Indices of genetic diversity were unchanged in the island population of N. temporalis; however, allelic richness was significantly lower in the island population of Z. lateralis while both allelic richness and heterozygosity were significantly reduced in the two island-endemic species examined. Although parasite prevalence and genetic diversity generally conformed to expectations for an island system, we did not find evidence for a pattern of uniformly altered immune responses in island taxa, even amongst endemic taxa with the longest residence times. The island population of Z. lateralis exhibited a significantly reduced inflammatory cell-mediated response while levels of natural antibodies remained unchanged for this and the other recently introduced island taxon. In contrast, the island endemic A. rimitarae exhibited a significantly increased inflammatory response as well as higher levels of natural antibodies and complement. These measures were unchanged or lower in A. aequinoctialis. We suggest that small differences in the pathogenic landscape and the stochastic history of mutation and genetic drift are likely to be important in shaping the unique

  1. De Novo Transcriptome Characterization of a Sterilizing Trematode Parasite (Microphallus sp.) from Two Species of New Zealand Snails.

    PubMed

    Bankers, Laura; Neiman, Maurine

    2017-03-10

    Snail-borne trematodes represent a large, diverse, and evolutionarily, ecologically, and medically important group of parasites, often imposing strong selection on their hosts and causing host morbidity and mortality. Even so, there are very few genomic and transcriptomic resources available for this important animal group. We help to fill this gap by providing transcriptome resources from trematode metacercariae infecting two congeneric snail species, Potamopyrgus antipodarum and P. estuarinus This genus of New Zealand snails has gained prominence in large part through the development of P. antipodarum and its sterilizing trematode parasite Microphallus livelyi into a textbook model for host-parasite coevolutionary interactions in nature. By contrast, the interactions between Microphallus trematodes and P. estuarinus, an estuary-inhabiting species closely related to the freshwater P. antipodarum, are relatively unstudied. Here, we provide the first annotated transcriptome assemblies from Microphallus isolated from P. antipodarum and P. estuarinus We also use these transcriptomes to produce genomic resources that will be broadly useful to those interested in host-parasite coevolution, local adaption, and molecular evolution and phylogenetics of this and other snail-trematode systems. Analyses of the two Microphallus transcriptomes revealed that the two trematode types are more genetically differentiated from one another than are the M. livelyi infecting different populations of P. antipodarum, suggesting that the Microphallus infecting P. estuarinus represent a distinct lineage. We also provide a promising set of candidate genes likely involved in parasitic infection and response to salinity stress.

  2. De Novo Transcriptome Characterization of a Sterilizing Trematode Parasite (Microphallus sp.) from Two Species of New Zealand Snails

    PubMed Central

    Bankers, Laura; Neiman, Maurine

    2017-01-01

    Snail-borne trematodes represent a large, diverse, and evolutionarily, ecologically, and medically important group of parasites, often imposing strong selection on their hosts and causing host morbidity and mortality. Even so, there are very few genomic and transcriptomic resources available for this important animal group. We help to fill this gap by providing transcriptome resources from trematode metacercariae infecting two congeneric snail species, Potamopyrgus antipodarum and P. estuarinus. This genus of New Zealand snails has gained prominence in large part through the development of P. antipodarum and its sterilizing trematode parasite Microphallus livelyi into a textbook model for host–parasite coevolutionary interactions in nature. By contrast, the interactions between Microphallus trematodes and P. estuarinus, an estuary-inhabiting species closely related to the freshwater P. antipodarum, are relatively unstudied. Here, we provide the first annotated transcriptome assemblies from Microphallus isolated from P. antipodarum and P. estuarinus. We also use these transcriptomes to produce genomic resources that will be broadly useful to those interested in host–parasite coevolution, local adaption, and molecular evolution and phylogenetics of this and other snail–trematode systems. Analyses of the two Microphallus transcriptomes revealed that the two trematode types are more genetically differentiated from one another than are the M. livelyi infecting different populations of P. antipodarum, suggesting that the Microphallus infecting P. estuarinus represent a distinct lineage. We also provide a promising set of candidate genes likely involved in parasitic infection and response to salinity stress. PMID:28122948

  3. Effects of tropism and virulence of Leishmania parasites on cytokine production by infected human monocytes

    PubMed Central

    Meddeb-Garnaoui, A; Zrelli, H; Dellagi, K

    2009-01-01

    The nature of early interactions between Leishmania and macrophages which determine the outcome of infection can be related directly to parasite biological properties. Here we compared the capacity of L. major (Lm) strains, reported to be high (LmHV) and low virulent and (LmLV) in the mouse model and L. infantum (Li) strains, dermotropic (LiD) and viscerotropic (LiV), to infect and modulate cytokine production in human peripheral blood derived monocytes. Monocytes were infected with metacyclic promastigotes for 24, 48 and 72 h. Parasite burden was significantly higher in Lm- than in Li-infected monocytes. LmHV and LiD induced a significantly higher parasite burden than LmLV and LiV respectively. Cytokine production was evaluated in monocytes infected for 24 h. Contrary to interleukin (IL)-12p70, monocyte chemotactic protein-1 and transforming growth factor-β production was increased significantly in infected monocytes with no differences between strains. Lm isolates induced significantly higher quantities of tumour necrosis factor (TNF)-α than Li isolates. Low levels of IL-10 were induced by all Leishmania strains and, interestingly, co-stimulation with lipopolysaccharide (LPS) was accompanied by a dramatic increase in IL-10 production by infected monocytes. In conclusion, Lm isolates displaying different levels of virulence in mice exhibited significant differences in parasite burden but similar abilities to modulate cytokine production in human monocytes. Li strains showed weaker infectivity and TNF-α inducing-capacity compared with Lm strains. The dramatic increase of IL-10 production in infected monocytes co-stimulated by LPS may play a role in disease progression considering the presence of LPS during bacterial superinfections observed during human leishmaniasis. PMID:19040614

  4. Determination of natural resistance frequencies in Penicillium digitatum using a new air-sampling method and characterization of fludioxonil- and pyrimethanil-resistant isolates.

    PubMed

    Kanetis, L; Förster, H; Adaskaveg, J E

    2010-08-01

    ABSTRACT Fungicide resistance was identified in natural populations of Penicillium digitatum, the causal agent of green mold of citrus, to two of three new postharvest fungicides before their commercial use. Using a new air-sampling method where large populations of the pathogen in citrus packinghouses were exposed to agar plates with a continuous, wide-range fungicide concentration gradient, isolates with reduced sensitivity to fludioxonil or pyrimethanil were obtained. Resistance frequencies to fludioxonil and pyrimethanil were calculated as 9.5 x 10(-7) to 1.5 x 10(-5) and 7.3 x 10(-6) to 6.2 x 10(-5), respectively. No isolates resistant to azoxystrobin were detected. Isolates with reduced sensitivity to fludioxonil or pyrimethanil were also obtained in laboratory selection studies, where high concentrations of conidial mixtures of isolates sensitive to the three fungicides were plated onto agar amended with each fungicide at 10 microg/ml. Isolates obtained from fludioxonil selection plates in laboratory and packinghouse experiments were placed into two categories based on mycelial growth: moderately resistant isolates had 50% effective concentration (EC(50)) values of 0.1 to 0.82 microg/ml and highly resistant isolates had EC(50) values > 1.5 microg/ml. Isolates resistant to pyrimethanil all had EC(50) values >8 microg/ml. Representative isolates of the two categories with reduced sensitivity to fludioxonil varied widely in their virulence and sporulation capacity as measured by the incidence of decay and degree of sporulation on inoculated fruit, respectively, whereas pyrimethanil-resistant isolates were mostly similar to the wild-type isolate. Fungicide sensitivity characteristics for isolates from fludioxonil and pyrimethanil selection plates remained stable after passages on nonamended agar, and disease could not be controlled after treatment with the respective fungicides. Types of fungicide resistance were visualized on thiabendazole- (TBZ) and imazalil

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

    USGS Publications Warehouse

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

    2006-01-01

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

  6. Host species exploitation and discrimination by animal parasites.

    PubMed

    Forbes, Mark R; Morrill, André; Schellinck, Jennifer

    2017-05-05

    Parasite species often show differential fitness on different host species. We developed an equation-based model to explore conditions favouring host species exploitation and discrimination. In our model, diploid infective stages randomly encountered hosts of two species; the parasite's relative fitness in exploiting each host species, and its ability to discriminate between them, was determined by the parasite's genotype at two independent diallelic loci. Relative host species frequency determined allele frequencies at the exploitation locus, whereas differential fitness and combined host density determined frequency of discrimination alleles. The model predicts instances where populations contain mixes of discriminatory and non-discriminatory infective stages. Also, non-discriminatory parasites should evolve when differential fitness is low to moderate and when combined host densities are low, but not so low as to cause parasite extinction. A corollary is that parasite discrimination (and host-specificity) increases with higher combined host densities. Instances in nature where parasites fail to discriminate when differential fitness is extreme could be explained by one host species evolving resistance, following from earlier selection for parasite non-discrimination. Similar results overall were obtained for haploid extensions of the model. Our model emulates multi-host associations and has implications for understanding broadening of host species ranges by parasites.This article is part of the themed issue 'Opening the black box: re-examining the ecology and evolution of parasite transmission'.

  7. Global change, parasite transmission and disease control: lessons from ecology

    PubMed Central

    Boag, Brian; Ellison, Amy R.; Morgan, Eric R.; Murray, Kris; Pascoe, Emily L.; Sait, Steven M.; Booth, Mark

    2017-01-01

    Parasitic infections are ubiquitous in wildlife, livestock and human populations, and healthy ecosystems are often parasite rich. Yet, their negative impacts can be extreme. Understanding how both anticipated and cryptic changes in a system might affect parasite transmission at an individual, local and global level is critical for sustainable control in humans and livestock. Here we highlight and synthesize evidence regarding potential effects of ‘system changes’ (both climatic and anthropogenic) on parasite transmission from wild host–parasite systems. Such information could inform more efficient and sustainable parasite control programmes in domestic animals or humans. Many examples from diverse terrestrial and aquatic natural systems show how abiotic and biotic factors affected by system changes can interact additively, multiplicatively or antagonistically to influence parasite transmission, including through altered habitat structure, biodiversity, host demographics and evolution. Despite this, few studies of managed systems explicitly consider these higher-order interactions, or the subsequent effects of parasite evolution, which can conceal or exaggerate measured impacts of control actions. We call for a more integrated approach to investigating transmission dynamics, which recognizes these complexities and makes use of new technologies for data capture and monitoring, and to support robust predictions of altered parasite dynamics in a rapidly changing world. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289256

  8. Host species exploitation and discrimination by animal parasites

    PubMed Central

    Forbes, Mark R.; Morrill, André; Schellinck, Jennifer

    2017-01-01

    Parasite species often show differential fitness on different host species. We developed an equation-based model to explore conditions favouring host species exploitation and discrimination. In our model, diploid infective stages randomly encountered hosts of two species; the parasite's relative fitness in exploiting each host species, and its ability to discriminate between them, was determined by the parasite's genotype at two independent diallelic loci. Relative host species frequency determined allele frequencies at the exploitation locus, whereas differential fitness and combined host density determined frequency of discrimination alleles. The model predicts instances where populations contain mixes of discriminatory and non-discriminatory infective stages. Also, non-discriminatory parasites should evolve when differential fitness is low to moderate and when combined host densities are low, but not so low as to cause parasite extinction. A corollary is that parasite discrimination (and host-specificity) increases with higher combined host densities. Instances in nature where parasites fail to discriminate when differential fitness is extreme could be explained by one host species evolving resistance, following from earlier selection for parasite non-discrimination. Similar results overall were obtained for haploid extensions of the model. Our model emulates multi-host associations and has implications for understanding broadening of host species ranges by parasites. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289258

  9. Metabolomics and protozoan parasites.

    PubMed

    Paget, Timothy; Haroune, Nicolas; Bagchi, Sushmita; Jarroll, Edward

    2013-06-01

    In this review, we examine the state-of-the-art technologies (gas and liquid chromatography, mass spectroscopy and nuclear magnetic resonance, etc.) in the well-established area of metabolomics especially as they relate to protozoan parasites.

  10. Parasitic Diseases: Glossary

    MedlinePlus

    ... make it easier to diagnose certain infections/diseases. Protozoa: Single-celled, microscopic organisms that can perform all necessary functions of metabolism and reproduction. Some protozoa are free-living, while others parasitize other organisms ...

  11. Women and Parasitic Diseases

    MedlinePlus

    ... Travelers Women Health Professionals Public Health Departments Laboratory Science ... Infection with Toxoplasma gondii , a parasite found in undercooked meat, cat feces, soil, and untreated water can lead to severe brain ...

  12. Cytoskeleton of Apicomplexan Parasites

    PubMed Central

    Morrissette, Naomi S.; Sibley, L. David

    2002-01-01

    The Apicomplexa are a phylum of diverse obligate intracellular parasites including Plasmodium spp., the cause of malaria; Toxoplasma gondii and Cryptosporidium parvum, opportunistic pathogens of immunocompromised individuals; and Eimeria spp. and Theileria spp., parasites of considerable agricultural importance. These protozoan parasites share distinctive morphological features, cytoskeletal organization, and modes of replication, motility, and invasion. This review summarizes our current understanding of the cytoskeletal elements, the properties of cytoskeletal proteins, and the role of the cytoskeleton in polarity, motility, invasion, and replication. We discuss the unusual properties of actin and myosin in the Apicomplexa, the highly stereotyped microtubule populations in apicomplexans, and a network of recently discovered novel intermediate filament-like elements in these parasites. PMID:11875126

  13. Isolation of fungi from nature in the region of Botucatu, state of São Paulo, Brazil, an endemic area of paracoccidioidomycosis.

    PubMed

    Montenegro, M R; Miyaji, M; Franco, M; Nishimura, K; Coelho, K I; Horie, Y; Mendes, R P; Sano, A; Fukushima, K; Fecchio, D

    1996-01-01

    In an attempt to isolate Paracoccidioides brasiliensis from nature 887 samples of soil from Botucatu, SP, Brazil, were collected cultured in brain heart infusion agar supplemented with dextrose, in potato dextrose agar and in yeast extract starch dextrose agar, all with antibiotics, at 25 degrees and 37 degrees C. Five thermo-dependent dimorphic fungi morphologically resembling P. brasiliensis were isolated; two from armadillo holes; further studies of the biology, antigenicity and genetic features of the five dimorphic fungi are necessary to clarify their taxonomy and their possible relation to P. brasiliensis. In addition, 98 dematiaceous fungi and 581 different species of Aspergillus spp. were also isolated. Our findings emphasize that armadillos and their environment are associated with thermo-dimorphic fungi and confirm the ubiquity of pathogenic dematiaceous fungi and Aspergillus spp.

  14. Genetics of unstable alleles of the X chromosome genes isolated from natural populations of Drosophila melanogaster during the outburst of mutation yellow in 1982 to 1991 in Uman`

    SciTech Connect

    Zakharov, I.K.; Skibitskii, E.E.

    1995-08-01

    In 1982, a local increase of frequency of mutation yellow-2, which lasted for a decade, occurred in a population of Drosophila melanogaster from Uman` (Ukraine). Genetic properties (phenotypic difference, mutability, and pecularities of complementation) of alleles yellow-2, isolated from the population during the mutation outburst, and of their revertants, were studied. Allelic diversity, which reflected molecular differences in allele structure, was shown to appear. In addition to mutation yellow, isolated in 1990 from the Uman` population, mutational properties of other sex-linked genes (dusky, miniature, rudimentary, singed, and vermilion) isolated from natural populations in 1986 to 1990, were analyzed. Based on these data, the conclusion was drawn that the presence of unstable alleles in populations is not a sufficient condition for mutation outbursts. Comparative analysis of properties of yellow alleles obtained in different periods of the outburst continues. 17 refs., 4 tabs.

  15. Differential escape from parasites by two competing introduced crabs

    USGS Publications Warehouse

    Blakeslee, April M.; Keogh, Carolyn L.; Byers, James E.; Kuris, Armand M.; Lafferty, Kevin D.; Torchin, Mark E.

    2009-01-01

    Although introduced species often interact with one another in their novel communities, the role of parasites in these interactions remains less clear. We examined parasite richness and prevalence in 2 shorecrab species with different invasion histories and residency times in an introduced region where their distributions overlap broadly. On the northeastern coast of the USA, the Asian shorecrab Hemigrapsus sanguineus was discovered 20 yr ago, while the European green crab Carcinus maenas has been established for over 200 yr. We used literature and field surveys to evaluate parasitism in both crabs in their native and introduced ranges. We found only 1 parasite species infecting H. sanguineus on the US East Coast compared to 6 species in its native range, while C. maenas was host to 3 parasite species on the East Coast compared to 10 in its native range. The prevalence of parasite infection was also lower for both crabs in the introduced range compared to their native ranges; however, the difference was almost twice as much for H. sanguineus as for C. maenas. There are several explanations that could contribute to C. maenas' greater parasite diversity than that of H. sanguineus on the US East Coast, including differences in susceptibility, time since introduction, manner of introduction (vector), distance from native range, taxonomic isolation, and the potential for parasite identification bias. Our study underscores not just that non-native species lose parasites upon introduction, but that they may do so differentially, with ramifications for their direct interactions and with potential community-level influences.

  16. Rapid isolation and identification of minor natural products by LC-MS, LC-SPE-NMR and ECD: isoflavanones, biflavanones and bisdihydrocoumarins from Ormocarpum kirkii.

    PubMed

    Xu, Yong-Jiang; Foubert, Kenn; Dhooghe, Liene; Lemière, Filip; Maregesi, Sheila; Coleman, Christina M; Zou, Yike; Ferreira, Daneel; Apers, Sandra; Pieters, Luc

    2012-07-01

    The combination of the hyphenated techniques LC-MS and LC-SPE-NMR constitutes a powerful platform for the rapid isolation and identification of minor components from natural sources. Electronic circular dichroism (ECD) is a useful tool to determine the absolute configuration of small quantities of chiral molecules. In order to search for minor constituents present in an Ormocarpum kirkii extract, these techniques were applied for the separation and structure elucidation of a series of isoflavanones, biflavanones and biscoumarins. After optimization of chromatographic conditions and subsequent isolation, MS and 1D and 2D NMR data were collected. Experimental and calculated ECD spectra were used in conjunction with NMR data to confirm the absolute configuration of these compounds. Eight compounds were identified for the first time and six have been previously reported. The present approach offers a strategy for accelerating research on natural products.

  17. Parasites and human evolution.

    PubMed

    Perry, George H

    2014-01-01

    Our understanding of human evolutionary and population history can be advanced by ecological and evolutionary studies of our parasites. Many parasites flourish only in the presence of very specific human behaviors and in specific habitats, are wholly dependent on us, and have evolved with us for thousands or millions of years. Therefore, by asking when and how we first acquired those parasites, under which environmental and cultural conditions we are the most susceptible, and how the parasites have evolved and adapted to us and we in response to them, we can gain considerable insight into our own evolutionary history. As examples, the tapeworm life cycle is dependent on our consumption of meat, the divergence of body and head lice may have been subsequent to the development of clothing, and malaria hyperendemicity may be associated with agriculture. Thus, the evolutionary and population histories of these parasites are likely intertwined with critical aspects of human biology and culture. Here I review the mechanics of these and multiple other parasite proxies for human evolutionary history and discuss how they currently complement our fossil, archeological, molecular, linguistic, historical, and ethnographic records. I also highlight potential future applications of this promising model for the field of evolutionary anthropology.

  18. Isolation and nature of intracellular alpha-aminoadipic acid-containing peptides from Paecilomyces persicinus P-10.

    PubMed Central

    Eriquez, L A; Pisano, M A

    1979-01-01

    Small intracellular peptides containing alpha-aminoadipic acid, cysteine, and a valine moiety were obtained from mycelia of Paecilomyces persicinus P-10 by ethanol or trichloroacetic acid extraction. After performic acid oxidation and ion-exchange chromatography, analysis of the peptide fractions by two-dimensional thin-layer electrophoresis and chromatography revealed the presence of three related peptides, as sulfonic acid derivatives, each containing alpha-aminoadipic acid. Each peptide was isolated in chromatographically pure form by semipreparative thin-layer electrophoresis and chromatography. The purified peptides were subjected to differential hydrolysis, dansylation, and combined dansylation-phenylisothiocyanate sequence analysis. Based on these studies, the structures of the isolated peptides were determined to be (i) glycl-delta-(alpha-aminoadipyl)-cysteinyl-beta-hydroxyvaline, (ii) glycyl-delta-(alpha-aminoadipyl)-cysteinylvaline, and (iii) delta-(alpha-aminoadipyl)-cysteinylvaline. The peptides isolated from Paecilomyces are similar to the alpha-aminoadipic acid-cysteine-valine moiety complex peptides isolated from Cephalosporium. PMID:574371

  19. The isolation, total synthesis and structure elucidation of chlorofusin, a natural product inhibitor of the p53-MDM2 protein-protein interaction

    PubMed Central

    Clark, Ryan C.; Lee, Sang Yeul; Searcey, Mark; Boger, Dale L.

    2009-01-01

    Inhibitors of key protein-protein interactions are emerging as exciting therapeutic targets for the treatment of cancer. One such interaction between MDM2 (HDM2) and p53, that silences the tumour suppression activities of p53, was found to be inhibited by the recently isolated natural product chlorofusin. Synthetic studies on this complex natural product summarized herein have served to reassign its chromophore relative stereochemistry, assign its absolute stereochemistry, and provided access to a series of key analogues and partial structures for biological evaluation. PMID:19642417

  20. Simulating natural conditions in the laboratory: a re-examination of sexual isolation between sympatric and allopatric populations of Drosophila pseudoobscura and D. persimilis.

    PubMed

    Noor, Mohamed A F; Ortíz-Barrientos, Daniel

    2006-03-01

    Simulating natural conditions in the laboratory poses one of the most significant challenges to behavioral studies. Some authors have argued that laboratory "choice" experiments reflect mate choice in nature more accurately than "no-choice" experiments. A recent choice experiment study questioned the conclusions of several earlier studies by failing to detect a published difference in sexual isolation between populations of Drosophila pseudoobscura, and suggested their result was more robust because of the more realistic design. Here, we re-examine the methods and analyses of this recent study, and we find there was indeed a difference in sexual isolation between populations of D. pseudoobscura. We also conduct a more rigorously controlled choice experiment and, in agreement with previous studies, note that D. pseudoobscura females from populations sympatric to their sibling species, D. persimilis, exhibit greater sexual isolation than those from allopatric populations. Our results confirm the existence of a geographic pattern in sexual isolation in D. pseudoobscura, and we discuss differences in experimental designs in light of the biology of this species.

  1. Parasites in marine food webs

    USGS Publications Warehouse

    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.

  2. Antimicrobial susceptibility pattern of Edwardsiella ictaluri isolates from natural outbreaks of bacillary necrosis of Pangasianodon hypophthalmus in Vietnam.

    PubMed

    Tu, Thanh Dung; Haesebrouck, Freddy; Nguyen, Anh Tuan; Sorgeloos, Patrick; Baele, Margo; Decostere, Annemie

    2008-12-01

    The purpose of this study was to assess the in vitro susceptibility of 64 Vietnamese isolates of Edwardsiella ictaluri, the causal agent of the infectious disease Bacillus Necrosis Pangasius in Pangasianodon hypophthalmus, using the agar dilution technique. All isolates originated from different farms and were collected between 2002 and 2005. None of the isolates displayed acquired resistance to amoxicillin, amoxicillin-clavulanic acid, chloramphenicol, florfenicol, gentamicin, kanamycin, neomycin, and nitrofurantoin. Acquired resistance to streptomycin was detected in 83%, to oxytetracycline in 81%, and to trimethoprim in 71% of the isolates, as indicated by a bimodal distribution of the minimal inhibitory concentrations (MICs) of these antimicrobials. The MICs of enrofloxacin displayed a monomodal distribution with tailing toward the higher MIC values, possibly indicating reduced susceptibility of a minority of isolates (3 out of the 64). For the quinolone antimicrobial agents flumequin and oxolinic acid, acquired resistance was encountered in 8% and 6% of the strains, respectively. All strains were intrinsically resistant to the polypeptide antimicrobial agent colistin. Seventy-three percent of the isolates were shown to have acquired resistance to at least three antimicrobial agents. The results of this study emphasize the strict need to control both the prophylactic and curative use of antimicrobial agents in Vietnamese aquaculture.

  3. Ancylostoma ceylanicum, a re-emerging but neglected parasitic zoonosis.

    PubMed

    Traub, Rebecca J

    2013-11-01

    Although Ancylostoma ceylanicum is known to be an endemic and widely distributed hookworm of dogs and cats in Asia, its contribution to human morbidity as a potentially zoonotic hookworm remains largely unexplored. Since its discovery by Lane (1913) as a 'new parasite' of humans a century ago, the hookworm has been regarded as a 'rare' and 'abnormal' parasite and largely overlooked in surveys of human parasites. Recent molecular-based surveys in Asia, however, have demonstrated that A. ceylanicum is the second most common hookworm species infecting humans, comprising between 6% and 23% of total patent hookworm infections. In experimentally induced infections, A. ceylanicum mimics the clinical picture produced by the anthroponotic hookworms of 'ground itch' and moderate to severe abdominal pain in the acute phase. Natural infections with A. ceylanicum in humans have been reported in almost all geographical areas in which the hookworm is known to be endemic in dogs and cats, however for the majority of reports, no clinical data are available. Much like the anthroponotic hookworm species, patent A. ceylanicum adults can isolate within the jejunum to produce chronic infections that on occasion, may occur in high enough burdens to produce anaemia. In addition, the hookworm can act much like Ancylostoma caninum and be found lower in the gastrointestinal tract leading to abdominal distension and pain, diarrhoea and occult blood in the faeces accompanied by peripheral eosinophilia. Whether A. ceylanicum is capable of producing both classical hookworm disease and evoking morbidity through an uncontrolled allergic response in some individuals remains unascertained. Future investigations combining the use of molecular diagnostic tools with clinical and pathological data will shed further light on its role as a human pathogen. The control of this zoonosis necessitates an integrated and inter-sectorial "One Health" approach be adopted in communities where large numbers of dogs

  4. Isolation of murine intrahepatic immune cells employing a modified procedure for mechanical disruption and functional characterization of the B, T and natural killer T cells obtained.

    PubMed

    Blom, K G; Qazi, M Rahman; Matos, J B Noronha; Nelson, B D; DePierre, J W; Abedi-Valugerdi, M

    2009-02-01

    Intrahepatic immune cells (IHIC) are known to play central roles in immunological responses mediated by the liver, and isolation and phenotypic characterization of these cells is therefore of considerable importance. In the present investigation, we developed a simple procedure for the mechanical disruption of mouse liver that allows efficient isolation and phenotypic characterization of IHIC. These cells are compared with the corresponding cells purified from the liver after enzymatic digestion with different concentrations of collagenase and DNase. The mechanical disruption yielded viable IHIC in considerably greater numbers than those obtained following enzymatic digestion. The IHIC isolated employing the mechanical disruption were heterogeneous in composition, consisting of both innate and adaptive immune cells, of which B, T, natural killer (NK), NK T cells, granulocytes and macrophages were the major populations (constituting 37.5%, 16.5%, 12.1%, 7.9%, 7.9% and 7.5% of the total number of cells recovered respectively). The IHIC obtained following enzymatic digestion contained markedly lower numbers of NK T cells (1.8%). The B, T and NK T cells among IHIC isolated employing mechanical disruption were found to be immunocompetent, i.e. they proliferated in vitro in response to their specific stimuli (lipopolysaccharide, concanavalin A and alpha-galactosylceramide respectively) and produced immunoglobulin M and interferon-gamma. Thus, the simple procedure for the mechanical disruption of mouse liver described here results in more efficient isolation of functionally competent IHIC for various types of investigation.

  5. Identification and molecular characterization of two naturally occurring Soybean mosaic virus isolates that are closely related but differ in their ability to overcome Rsv4 resistance.

    PubMed

    Gagarinova, Alla G; Babu, Mohan; Poysa, Vaino; Hill, John H; Wang, Aiming

    2008-12-01

    A naturally occurring Rsv4 resistance-breaking isolate (L-RB) and a closely related non-resistance-breaking isolate (L) of Soybean mosaic virus (SMV) were identified in soybean fields in London, Ontario, Canada. The viral genomes of L and L-RB were completely sequenced. Each isolate has a 9585-nucleotide genome with a single open reading frame encoding a polyprotein of approximately 350 kDa. L-RB and L have a very high sequence similarity (99.6%) at both the nucleotide and amino acid levels. Phylogenetic analysis showed that the two isolates belong to the G2 pathotype. Pathogenicity predictions of all virus/soybean combinations, based on the phylogenetic profile, were confirmed by pathogenicity tests using L and L-RB isolates and soybeans carrying different resistance genes, with an exception that L-RB infected a soybean cultivar carrying Rsv4 resistance. The temporal and spatial proximity of L and L-RB and their high sequence similarity suggest L-RB was likely derived from the SMV-L quasispecies. Recombination analysis did not reveal the evidence of genetic recombination for the emergence of L-RB. Mutations introduced by virus-encoded RNA-dependent RNA polymerase during viral genome replication and selection pressure probably contributed to the occurrence of L-RB.

  6. Conflicts over host manipulation between different parasites and pathogens: Investigating the ecological and medical consequences

    PubMed Central

    2016-01-01

    When parasites have different interests in regard to how their host should behave this can result in a conflict over host manipulation, i.e. parasite induced changes in host behaviour that enhance parasite fitness. Such a conflict can result in the alteration, or even complete suppression, of one parasite's host manipulation. Many parasites, and probably also symbionts and commensals, have the ability to manipulate the behaviour of their host. Non‐manipulating parasites should also have an interest in host behaviour. Given the frequency of multiple parasite infections in nature, potential conflicts of interest over host behaviour and manipulation may be common. This review summarizes the evidence on how parasites can alter other parasite's host manipulation. Host manipulation can have important ecological and medical consequences. I speculate on how a conflict over host manipulation could alter these consequences and potentially offer a new avenue of research to ameliorate harmful consequences of host manipulation. PMID:27510821

  7. Conflicts over host manipulation between different parasites and pathogens: Investigating the ecological and medical consequences.

    PubMed

    Hafer, Nina

    2016-10-01

    When parasites have different interests in regard to how their host should behave this can result in a conflict over host manipulation, i.e. parasite induced changes in host behaviour that enhance parasite fitness. Such a conflict can result in the alteration, or even complete suppression, of one parasite's host manipulation. Many parasites, and probably also symbionts and commensals, have the ability to manipulate the behaviour of their host. Non-manipulating parasites should also have an interest in host behaviour. Given the frequency of multiple parasite infections in nature, potential conflicts of interest over host behaviour and manipulation may be common. This review summarizes the evidence on how parasites can alter other parasite's host manipulation. Host manipulation can have important ecological and medical consequences. I speculate on how a conflict over host manipulation could alter these consequences and potentially offer a new avenue of research to ameliorate harmful consequences of host manipulation.

  8. Genome Similarity Implies that Citrus-Parasitic Burrowing Nematodes do not Represent a Unique Species.

    PubMed

    Kaplan, D T; Opperman, C H

    1997-12-01

    Burrowing nematodes from Central America, Dominican Republic, Florida, Guadeloupe, Hawaii, and Puerto Rico were characterized for their ability to parasitize citrus, but citrus parasites were found only in Florida. Sequence tag sites originally amplified from a citrus-parasitic burrowing nematode were polymorphic among 37 burrowing nematode isolates and were not correlated with citrus parasitism, nematode isolate collection site, or amplification of a 2.4-kb sequence tag site (DK#1). Results of a RAPD analysis and characterization of the isozymes phosphoglucose isomerase, lactate dehydrogenase, and malate dehydrogenase indicated that the burrowing nematode isolates were highly similar. Citrus parasitism in Florida appears to be associated with limited changes in the burrowing nematode genome. Findings did not substantiate a previous report that R. citrophilus was present in Hawaii. Overall, these data do not support assignment of sibling species status to burrowing nematodes that differ with respect to citrus parasitism.

  9. Genotyping of Mycobacterium avium subsp. avium isolates from naturally infected lofts of domestic pigeons in Ahvaz by IS901 RFLP

    PubMed Central

    Parvandar-Asadollahi, Kaveh; Mosavari, Nader; Mayahi, Mansoor

    2015-01-01

    Background and Objectives: Avian tuberculosis is one of the most important infections affecting most species of birds. Mycobacterium avium can not only infect all species of birds, but also infect some domesticated mammals. The most crucial aspect of control and eradication scheme is identification of infection sources and transmission routs. Molecular techniques such as restriction fragment length polymorphism and pulse field gel electrophoresis have been shown to be much more discriminatory and suitable for use in the epidemiological study. Materials and Methods: Eighty suspected pigeons to avian tuberculosis based on their clinical signs, were subjected to the study. Forty Mycobacterium avium subsp. avium isolates out of a total of 51 identified isolates were subjected to the test. Results: IS901-RFLP using Pvu II was successfully conducted and produced 7 patterns. The majority of isolates (60%) were RFLP type PI.1. This type was the most similar type to standard strain. However, all the patterns obtained in this study were different from the standard strain. Conclusion: The result of this study indicate that these isolates probably are limited to Khuzestan region. We recommend DNA fingerprinting differentiation of non tuberculous Mycobacteria particularly Mycobacterium avium complex isolated from infected birds and human to possibly find source of infections. PMID:26719782

  10. Rickettsia rickettsii isolation from naturally infected Amblyomma parvum ticks by centrifugation in a 24-well culture plate technique

    PubMed Central

    Dzul-Rosado, K.; Peniche-Lara, G.; Tello-Martín, R.; Zavala-Velázquez, J.; Pacheco, R. de Campos; Labruna, M.B.; Sánchez, E.C.; Zavala-Castro, J.

    2013-01-01

    Rocky Mountain spotted fever is an acute illness caused by Rickettsia rickettsii (R. rickettsii) and is transmitted by the bite of ticks of the genera Dermacentor, Amblyomma and Rhipicephalus. The illness results in a high mortality rate and may be easily confused with other febrile syndromes. In Yucatan State, Mexico, childhood cases with a high mortality have been reported. In this work we report the isolation of a Mexican R. rickettsii strain from a tick egg mass using an alternative method for Rickettsia isolation with 24-well plates. We also identified a potential vector of R. rickettsii in the southeast of Mexico, which is Amblyomma parvum. PMID:26623321

  11. Zoonotic foodborne parasites and their surveillance.

    PubMed

    Murrell, K D

    2013-08-01

    Humans suffer from several foodborne helminth zoonotic diseases, some of which can be deadly (e.g., trichinellosis, cerebral cysticercosis) while others are chronic and cause only mild illness (e.g., intestinal taeniosis). The route of infection is normally consumption of the parasite's natural host as a human food item (e.g., meat). The risk for infection with these parasites is highest wherever people have an inadequate knowledge of infection and hygiene, poor animal husbandry practices, and unsafe management and disposal of human and animal waste products. The design of surveillance and control strategies for the various foodborne parasite species, and the involvement of veterinary and public health agencies, vary considerably because of the different life cycles of these parasites, and epidemiological features. Trichinella spiralis, which causes most human trichinellosis, is acquired from the consumption of pork, although increasingly cases occur from eating wild game. For cysticercosis, however, the only sources for human infection are pork (Taenia solium) or beef (T. saginata). The chief risk factor for infection of humans with these parasites is the consumption of meat that has been inadequately prepared. For the pig or cow, however, the risk factors are quite different between Trichinella and Taenia. For T. spiralis the major source of infection of pigs is exposure to infected animal meat (which carries the infective larval stage), while for both Taenia species it is human faecal material contaminated with parasite eggs shed by the adult intestinal stage of the tapeworm. Consequently, the means for preventing exposure of pigs and cattle to infective stages of T. spiralis, T. solium, and T. saginata vary markedly, especially the requirements for ensuring the biosecurity of these animals at the farm. The surveillance strategies and methods required for these parasites in livestock are discussed, including the required policy-level actions and the necessary

  12. [Main parasitic skin disorders].

    PubMed

    Bernigaud, C; Monsel, G; Delaunay, P; Do-Pham, G; Foulet, F; Botterel, F; Chosidow, O

    2017-01-01

    Cutaneous parasitic skin diseases are frequent in human pathology. There are few reliable epidemiological data on the prevalence and/or incidence of such diseases. Skin parasites are cosmopolitan but their global distribution is heterogenous; prevalence is especially high in subtropical and tropical countries. They are mainly due to arthropods (insects and mites). Many species of parasites are involved, explaining the diversity of their clinical signs. The most common are caused by ectoparasites such as scabies or pediculosis (head lice, body lice and pubic lice). Clinical signs may be related to the penetration of the parasite under the skin, its development, the inoculation of venom or allergic symptoms. Diagnosis can be easy when clinical signs are pathognomonic (e.g. burrows in the interdigital web spaces in scabies) or sometimes more difficult. Some epidemiological characteristics (diurnal or nocturnal bite, seasonality) and specific clinical presentation (single or multiple bites, linear or grouped lesions) can be a great diagnostic help. Modern non-invasive tools (dermoscopy or confocal microscopy) will play an important role in the future but the eye and experience of the specialist (dermatologist, parasitologist, infectious disease specialist or entomologist) remains for the time the best way to guide or establish a diagnosis. For most skin parasites, therapeutic proposals are rarely based on studies of high level of evidence or randomized trials but more on expert recommendations or personal experience.

  13. [Pseudo-parasites in histology and cytopathology].

    PubMed

    Pierre, C; Carloz, E; Marlier-Civatte, M; Branquet, D; Gros, P

    1995-01-01

    When interpreting smears and specimens, histologist and cytopathologists can be misled by images mimicking micro-organisms especially parasites such as protozoa, mycotic agents or helminths. Although some of these pitfalls are well-known, others can be problematic especially if nature of the contaminant is the same as that of the parasite that it mimics. False protozoa parasites can correspond either to exogenous agents such as spores, remnants of human cells, or inert exogenous particles. Pseudo-yeast images can be due to pollen, starch or soot but especially to cells such as macrophages, spermatozoids, and neurons or to various inert bodies such as pigments or calcifications. Pseudomycotic filaments can result from vegetable silk, asbestos bodies, radiate granules or fibrin. Curschmann's spirals and vegetable fibers can be confused with helminths and bacterial particles or pollen with helminth eggs.

  14. Niche metabolism in parasitic protozoa.

    PubMed

    Ginger, Michael L

    2006-01-29

    Complete or partial genome sequences have recently become available for several medically and evolutionarily important parasitic protozoa. Through the application of bioinformatics complete metabolic repertoires for these parasites can be predicted. For experimentally intractable parasites insight provided by metabolic maps generated in silico has been startling. At its more extreme end, such bioinformatics reckoning facilitated the discovery in some parasites of mitochondria remodelled beyond previous recognition, and the identification of a non-photosynthetic chloroplast relic in malarial parasites. However, for experimentally tractable parasites, mapping of the general metabolic terrain is only a first step in understanding how the parasite modulates its streamlined, yet still often puzzlingly complex, metabolism in order to complete life cycles within host, vector, or environment. This review provides a comparative overview and discussion of metabolic strategies used by several different parasitic protozoa in order to subvert and survive host defences, and illustrates how genomic data contribute to the elucidation of parasite metabolism.

  15. Ecosystem consequences of fish parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2008-01-01

    In most aquatic ecosystems, fishes are hosts to parasites and, sometimes, these parasites can affect fish biology. Some of the most dramatic cases occur when fishes are intermediate hosts for larval parasites. For example, fishes in southern California estuaries are host to many parasites. The most common of these parasites, Euhaplorchis californiensis, infects the brain of the killifish Fundulus parvipinnis and alters its behaviour, making the fish 10–30 times more susceptible to predation by the birds that serve as its definitive host. Parasites like E. californiensis are embedded in food webs because they require trophic transmission. In the Carpinteria Salt Marsh estuarine food web, parasites dominate the links and comprise substantial amount of biomass. Adding parasites to food webs alters important network statistics such as connectance and nestedness. Furthermore, some free-living stages of parasites are food items for free-living species. For instance, fishes feed on trematode cercariae. Being embedded in food webs makes parasites sensitive to changes in the environment. In particular, fishing and environmental disturbance, by reducing fish populations, may reduce parasite populations. Indirect evidence suggests a decrease in parasites in commercially fished species over the past three decades. In addition, environmental degradation can affect fish parasites. For these reasons, parasites in fishes may serve as indicators of environmental impacts.

  16. Canonical and variant histones of protozoan parasites.

    PubMed

    Dalmasso, Maria Carolina; Sullivan, William Joseph; Angel, Sergio Oscar

    2011-06-01

    Protozoan parasites have tremendously diverse lifestyles that require adaptation to a remarkable assortment of different environmental conditions. In order to complete their life cycles, protozoan parasites rely on fine-tuning gene expression. In general, protozoa use novel regulatory elements, transcription factors, and epigenetic mechanisms to regulate their transcriptomes. One of the most surprising findings includes the nature of their histones--these primitive eukaryotes lack some histones yet harbor novel histone variants of unknown function. In this review, we describe the histone components of different protozoan parasites based on literature and database searching. We summarize the key discoveries regarding histones and histone variants and their impact on chromatin regulation in protozoan parasites. In addition, we list histone genes IDs, sequences, and genomic localization of several protozoan parasites and Microsporidia histones, obtained from a thorough search of genome databases. We then compare these findings with those observed in higher eukaryotes, allowing us to highlight some novel aspects of epigenetic regulation in protists and to propose questions to be addressed in the upcoming years.

  17. The comparative ecology and biogeography of parasites

    PubMed Central

    Poulin, Robert; Krasnov, Boris R.; Mouillot, David; Thieltges, David W.

    2011-01-01

    Comparative ecology uses interspecific relationships among traits, while accounting for the phylogenetic non-independence of species, to uncover general evolutionary processes. Applied to biogeographic questions, it can be a powerful tool to explain the spatial distribution of organisms. Here, we review how comparative methods can elucidate biogeographic patterns and processes, using analyses of distributional data on parasites (fleas and helminths) as case studies. Methods exist to detect phylogenetic signals, i.e. the degree of phylogenetic dependence of a given character, and either to control for these signals in statistical analyses of interspecific data, or to measure their contribution to variance. Parasite–host interactions present a special case, as a given trait may be a parasite trait, a host trait or a property of the coevolved association rather than of one participant only. For some analyses, it is therefore necessary to correct simultaneously for both parasite phylogeny and host phylogeny, or to evaluate which has the greatest influence on trait expression. Using comparative approaches, we show that two fundamental properties of parasites, their niche breadth, i.e. host specificity, and the nature of their life cycle, can explain interspecific and latitudinal variation in the sizes of their geographical ranges, or rates of distance decay in the similarity of parasite communities. These findings illustrate the ways in which phylogenetically based comparative methods can contribute to biogeographic research. PMID:21768153

  18. Codon optimization underpins generalist parasitism in fungi

    PubMed Central

    Badet, Thomas; Peyraud, Remi; Mbengue, Malick; Navaud, Olivier; Derbyshire, Mark; Oliver, Richard P; Barbacci, Adelin; Raffaele, Sylvain

    2017-01-01

    The range of hosts that parasites can infect is a key determinant of the emergence and spread of disease. Yet, the impact of host range variation on the evolution of parasite genomes remains unknown. Here, we show that codon optimization underlies genome adaptation in broad host range parasites. We found that the longer proteins encoded by broad host range fungi likely increase natural selection on codon optimization in these species. Accordingly, codon optimization correlates with host range across the fungal kingdom. At the species level, biased patterns of synonymous substitutions underpin increased codon optimization in a generalist but not a specialist fungal pathogen. Virulence genes were consistently enriched in highly codon-optimized genes of generalist but not specialist species. We conclude that codon optimization is related to the capacity of parasites to colonize multiple hosts. Our results link genome evolution and translational regulation to the long-term persistence of generalist parasitism. DOI: http://dx.doi.org/10.7554/eLife.22472.001 PMID:28157073

  19. Nature's Cholesterol-Lowering Drug: Isolation and Structure Elucidation of Lovastatin from Red Yeast Rice-Containing Dietary Supplements

    ERIC Educational Resources Information Center

    Nazri, Maisarah Mohd; Samat, Farah D.; Kavanagh, Pierce V.; Walsh, John J.

    2012-01-01

    Red yeast rice, produced by fermenting the fungus, "Monascus purpureus", on rice ("Oryza sativa" L. gramineae), is commonly used as a dietary supplement. It contains lovastatin, a member of the statin family of compounds, and is licensed for use as a cholesterol-lowering agent. This experiment involves the isolation and structure elucidation of…

  20. EFFECTS OF REVERSE OSMOSIS ISOLATION ON REACTIVITY OF NATURALLY OCCURRING DISSOLVED ORGANIC MATTER IN PHYSICOCHEMICAL PROCESSES. (R828045)

    EPA Science Inventory

    A field reverse osmosis system was used to isolate dissolved organic matter (DOM) from two lacustrine and two riverine surface water sources. The rejection of DOM was on the order of 99% and did not vary significantly with pressure. A simple mass balance model using a single m...

  1. New method for the rapid extraction of natural products: efficient isolation of shikimic acid from star anise.

    PubMed

    Just, Jeremy; Deans, Bianca J; Olivier, Wesley J; Paull, Brett; Bissember, Alex C; Smith, Jason A

    2015-05-15

    A new, practical, rapid, and high-yielding process for the pressurized hot water extraction (PHWE) of multigram quantities of shikimic acid from star anise (Illicium verum) using an unmodified household espresso machine has been developed. This operationally simple and inexpensive method enables the efficient and straightforward isolation of shikimic acid and the facile preparation of a range of its synthetic derivatives.

  2. Are there general laws in parasite ecology?

    PubMed

    Poulin, R

    2007-06-01

    As a scientific discipline matures, its theoretical underpinnings tend to consolidate around a few general laws that explain a wide range of phenomena, and from which can be derived further testable predictions. It is one of the goals of science to uncover the general principles that produce recurring patterns in nature. Although this has happened in many areas of physics and chemistry, ecology is yet to take this important step. Ecological systems are intrinsically complex, but this does not necessarily mean that everything about them is unpredictable or chaotic. Ecologists, whose grand aim is to understand the interactions that govern the distribution, abundance and diversity of living organisms at different scales, have uncovered several regular patterns, i.e. widely observable statistical tendencies, in the abundance or diversity of organisms in natural ecosystems. Some of these patterns, however, are contingent, i.e. they are only true under particular circumstances; nevertheless, the broad generality of many patterns hints at the existence of universal principles. What about parasite ecology: is it also characterized by recurring patterns and general principles? Evidence for repeatable empirical patterns in parasite ecology is reviewed here, in search of patterns that are consistently detectable across taxa or geographical areas. The coverage ranges from the population level all the way to large-scale patterns of parasite diversity and abundance (or biomass) and patterns in the structure of host-parasite interaction networks. Although general laws seem to apply to these extreme scales of studies, most patterns observed at the intermediate scale, i.e. the parasite community level, appear highly contingent and far from universal. The general laws uncovered to date are proving valuable, as they offer glimpses of the underlying processes shaping parasite ecology and diversity.

  3. Food stoichiometry affects the outcome of Daphnia–parasite interaction

    PubMed Central

    Aalto, Sanni L; Pulkkinen, Katja

    2013-01-01

    Phosphorus (P) is an essential nutrient for growth in consumers. P-limitation and parasite infection comprise one of the most common stressor pairs consumers confront in nature. We conducted a life-table study using a Daphnia–microsporidian parasite model, feeding uninfected or infected Daphnia with either P-sufficient or P-limited algae, and assessed the impact of the two stressors on life-history traits of the host. Both infection and P-limitation negatively affected some life-history traits tested. However, under P-limitation, infected animals had higher juvenile growth rate as compared with uninfected animals. All P-limited individuals died before maturation, regardless of infection. The numbers of spore clusters of the microsporidian parasite did not differ in P-limited or P-sufficient hosts. P-limitation, but not infection, decreased body phosphorus content and ingestion rates of Daphnia tested in separate experiments. As parasite spore production did not suffer even under extreme P-limitation, our results suggest that parasite was less limited by P than the host. We discuss possible interpretations concerning the stoichiometrical demands of parasite and suggest that our results are explained by parasite-driven changes in carbon (C) allocation of the hosts. We conclude that the impact of nutrient starvation and parasite infection on consumers depends not only on the stoichiometric demands of host but also those of the parasite. PMID:23762513

  4. Parasites grow larger in faster growing fish hosts.

    PubMed

    Barber, Iain

    2005-02-01

    Parasites depend on host-derived energy for growth and development, and so are potentially affected by the host's ability to acquire nutrients under competitive foraging scenarios. Although parasites might be expected to grow faster in hosts that are better at acquiring nutrients from natural ecosystems, it is also possible that the most competitive hosts are better at countering infections, if they have an improved immune response or are able to limit the availability of nutrients to parasites. I first quantified the ability of uninfected three-spined sticklebacks Gasterosteus aculeatus to compete in groups for sequentially-presented food items, and then exposed either the best or worst competitors to infective stages of the cestode Schistocephalus solidus. Fish were subsequently raised in their original groups, under competitive feeding regimes, for 96 days, after which fish and parasite growth was determined. Unexpectedly, pre-exposure host competitive ability had no effect on susceptibility to infection, or on post-infection growth rate. Furthermore, despite a 120-fold variation in parasite mass at the end of the study, pre-infection competitive ability was not related to parasite growth. The closest predictor of parasite mass was body size-corrected host growth rate, indicating that the fastest growing fish developed the largest parasites. Faster growing hosts therefore apparently provide ideal environments for growing parasites. This finding has important implications for ecology and aquaculture.

  5. Parasites and genetic diversity in an invasive bumblebee

    PubMed Central

    Jones, Catherine M; Brown, Mark J F; Ings, Thomas

    2014-01-01

    Biological invasions are facilitated by the global transportation of species and climate change. Given that invasions may cause ecological and economic damage and pose a major threat to biodiversity, understanding the mechanisms behind invasion success is essential. Both the release of non-native populations from natural enemies, such as parasites, and the genetic diversity of these populations may play key roles in their invasion success. We investigated the roles of parasite communities, through enemy release and parasite acquisition, and genetic diversity in the invasion success of the non-native bumblebee, Bombus hypnorum, in the United Kingdom. The invasive B. hypnorum had higher parasite prevalence than most, or all native congeners for two high-impact parasites, probably due to higher susceptibility and parasite acquisition. Consequently parasites had a higher impact on B. hypnorum queens’ survival and colony-founding success than on native species. Bombus hypnorum also had lower functional genetic diversity at the sex-determining locus than native species. Higher parasite prevalence and lower genetic diversity have not prevented the rapid invasion of the United Kingdom by B. hypnorum. These data may inform our understanding of similar invasions by commercial bumblebees around the world. This study suggests that concerns about parasite impacts on the small founding populations common to re-introduction and translocation programs may be less important than currently believed. PMID:24749545

  6. Alternative parasite development in transmission strategies: how time flies!

    PubMed

    Badets, M; Morrison, C; Verneau, O

    2010-10-01

    Among parasitic platyhelminths with complex life cycles, it has been well documented that transmission opportunities are the main forces shaping the diversity of life-history traits and parasite developmental strategies. While deviations in the development pathway usually involve shortening of life cycles, their extension may also occur following perception of remaining time by parasites. Polystoma gallieni, the monogenean parasite of Hyla meridionalis, is able to trigger two alternative developmental strategies depending on the physiological stage of the tadpoles upon which larvae attach. The distribution and reproductive outputs of both resulting phenotypes were surveyed to address questions about the dynamics of transmission in natural environments. Because modifications in the completion of life cycles can have drawbacks which may perturb the dynamic equilibrium of the resulting host-parasite systems, experimental infestations were also performed to assess parasite-parasite interactions. Our results suggest that the bladder adult phenotype, which involves transmission between frogs and tadpoles, is supplied secondarily by the branchial phenotype which involves transmission between tadpoles and metamorphs. They also support the occurrence of finely tuned trade-offs between hosts and parasites and highlight positive trends behind the extension of direct life cycles, in which host-derived signals account for the remaining time to achieve parasitic transmission.

  7. New natural products isolated from Metarhizium robertsii ARSEF 23 by chemical screening and identification of the gene cluster through engineered biosynthesis in Aspergillus nidulans A1145.

    PubMed

    Kato, Hiroki; Tsunematsu, Yuta; Yamamoto, Tsuyoshi; Namiki, Takuya; Kishimoto, Shinji; Noguchi, Hiroshi; Watanabe, Kenji

    2016-07-01

    To rapidly identify novel natural products and their associated biosynthetic genes from underutilized and genetically difficult-to-manipulate microbes, we developed a method that uses (1) chemical screening to isolate novel microbial secondary metabolites, (2) bioinformatic analyses to identify a potential biosynthetic gene cluster and (3) heterologous expression of the genes in a convenient host to confirm the identity of the gene cluster and the proposed biosynthetic mechanism. The chemical screen was achieved by searching known natural product databases with data from liquid chromatographic and high-resolution mass spectrometric analyses collected on the extract from a target microbe culture. Using this method, we were able to isolate two new meroterpenes, subglutinols C (1) and D (2), from an entomopathogenic filamentous fungus Metarhizium robertsii ARSEF 23. Bioinformatics analysis of the genome allowed us to identify a gene cluster likely to be responsible for the formation of subglutinols. Heterologous expression of three genes from the gene cluster encoding a polyketide synthase, a prenyltransferase and a geranylgeranyl pyrophosphate synthase in Aspergillus nidulans A1145 afforded an α-pyrone-fused uncyclized diterpene, the expected intermediate of the subglutinol biosynthesis, thereby confirming the gene cluster to be responsible for the subglutinol biosynthesis. These results indicate the usefulness of our methodology in isolating new natural products and identifying their associated biosynthetic gene cluster from microbes that are not amenable to genetic manipulation. Our method should facilitate the natural product discovery efforts by expediting the identification of new secondary metabolites and their associated biosynthetic genes from a wider source of microbes.

  8. Effects of synthetic and natural extraction chemicals on yield, composition and protein quality of soy protein isolates extracted from full-fat and defatted flours.

    PubMed

    Chamba, Moses Vernonxious Madalitso; Hua, Yufei; Murekatete, Nicole; Chen, Yeming

    2015-02-01

    With increasing preference for all-natural foods to those involving synthetic chemicals, native isoelectrically precipitated soy protein isolate (SPI) was prepared using amaranth (Amaranthus tricolor L.) lye (pH > 12.5) and lemon extract, (pH < 2.5) as natural, food-plant-based chemicals. Protein content (91.21 %), yield (43.62 %) and digestibility correlation amino acid score (0.77) were obtained and were comparable to those of SPI prepared using synthetic chemicals (NaOH and HCl). Methionine and cystein-s were significantly higher in the natural SPI while glutamine and serine were higher in synthetic SPI (p < 0.01). Most of the determined minerals were higher in the natural SPI with potassium being the highest. Sodium was very high in the synthetic SPI. The rest of the minerals including phosphorus, iron and nickel, showed no significant difference. Anti-nutritional factors (trypsin inhibitors and phytic acid) were considerably lower in the natural SPI. Thus, a quality all-natural SPI can be produced using amaranth lye and lemon extract to address concerns regarding use of synthetic chemicals.

  9. Parasitism of Dasineura oxycoccana (Diptera: Cecidomyiidae) in North Central Florida.

    PubMed

    Roubos, Craig R; Liburd, Oscar E

    2013-06-01

    Blueberry gall midge, Dasineura oxycoccana (Johnson), is a key pest of blueberries in Florida. As a larva, this insect feeds in developing flower and leaf buds. Management of D. oxycoccana relies principally on chemical insecticides; however, efficacy is limited because D. oxycoccana is sheltered within the plant during most of its life cycle. Natural enemies, particularly parasitoids, may play an important role in regulating D. oxycoccana populations. To determine the seasonal dynamics and parasitism rates of eulophid and platygastrid wasps parasitizing D. oxycoccana larvae, we sampled D. oxycoccana larvae by collecting infested blueberry leaf buds from a minimally-managed farm in north central Florida. Midge larvae were examined under a microscope to determine parasitism status of host instars. Parasitism rates ranged from 25 to 40% over the 3-yr study. Percent parasitization was significantly higher in third instars than first or second instars. Midge larvae in the centers of leaf buds were significantly less likely to be parasitized than larvae in outer layers of leaf buds. Thirty-seven percent of midge larvae had been parasitized multiple times, suggesting these parasitoids do not discriminate between parasitized and unparasitized hosts. Implications for pesticide use in relation to the conservation of natural enemies and management of D. oxycoccana populations are discussed.

  10. Malaria Parasites: The Great Escape

    PubMed Central

    Rénia, Laurent; Goh, Yun Shan

    2016-01-01

    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. PMID:27872623

  11. Selection against somatic parasitism can maintain allorecognition in fungi.

    PubMed

    Czárán, Tamas; Hoekstra, Rolf F; Aanen, Duur K

    2014-12-01

    Fusion between multicellular individuals is possible in many organisms with modular, indeterminate growth, such as marine invertebrates and fungi. Although fusion may provide various benefits, fusion usually is restricted to close relatives by allorecognition, also called heterokaryon or somatic incompatibility in fungi. A possible selective explanation for allorecognition is protection against somatic parasites. Such mutants contribute less to colony functions but more to reproduction. However, previous models testing this idea have failed to explain the high diversity of allorecognition alleles in nature. These models did not, however, consider the possible role of spatial structure. We model the joint evolution of allorecognition and somatic parasitism in a multicellular organism resembling an asexual ascomycete fungus in a spatially explicit simulation. In a 1000-by-1000 grid, neighbouring individuals can fuse, but only if they have the same allotype. Fusion with a parasitic individual decreases the total reproductive output of the fused individuals, but the parasite compensates for this individual-level fitness reduction by a disproportional share of the offspring. Allorecognition prevents the invasion of somatic parasites, and vice versa, mutation towards somatic parasitism provides the selective conditions for extensive allorecognition diversity. On the one hand, if allorecognition diversity did not build up fast enough, somatic parasites went to fixation; conversely, once parasites had gone to fixation no allorecognition diversity built up. On the other hand, the mere threat of parasitism could select for high allorecognition diversity, preventing invasion of somatic parasites. Moderate population viscosity combined with weak global dispersal was optimal for the joint evolution of allorecognition and protection against parasitism. Our results are consistent with the widespread occurrence of allorecognition in fungi and the low degree of somatic parasitism

  12. The impact of genomics on population genetics of parasitic diseases.

    PubMed

    Hupalo, Daniel N; Bradic, Martina; Carlton, Jane M

    2015-02-01

    Parasites, defined as eukaryotic microbes and parasitic worms that cause global diseases of human and veterinary importance, span many lineages in the eukaryotic Tree of Life. Historically challenging to study due to their complicated life-cycles and association with impoverished settings, their inherent complexities are now being elucidated by genome sequencing. Over the course of the last decade, projects in large sequencing centers, and increasingly frequently in individual research labs, have sequenced dozens of parasite reference genomes and field isolates from patient populations. This 'tsunami' of genomic data is answering questions about parasite genetic diversity, signatures of evolution orchestrated through anti-parasitic drug and host immune pressure, and the characteristics of populations. This brief review focuses on the state of the art of parasitic protist genomics, how the peculiar genomes of parasites are driving creative methods for their sequencing, and the impact that next-generation sequencing is having on our understanding of parasite population genomics and control of the diseases they cause.

  13. Microarray in parasitic infections

    PubMed Central

    Sehgal, Rakesh; Misra, Shubham; Anand, Namrata; Sharma, Monika

    2012-01-01

    Modern biology and genomic sciences are rooted in parasitic disease research. Genome sequencing efforts have provided a wealth of new biological information that promises to have a major impact on our understanding of parasites. Microarrays provide one of the major high-throughput platforms by which this information can be exploited in the laboratory. Many excellent reviews and technique articles have recently been published on applying microarrays to organisms for which fully annotated genomes are at hand. However, many parasitologists work on organisms whose genomes have been only partially sequenced. This review is mainly focused on how to use microarray in these situations. PMID:23508469

  14. Trichobilharzia anseri n. sp. (Schistosomatidae: Digenea), a new visceral species of avian schistosomes isolated from greylag goose (Anser anser L.) in Iceland and France.

    PubMed

    Jouet, D; Kolářová, L; Patrelle, C; Ferté, H; Skírnisson, K

    2015-08-01

    Parasitological investigations carried out on birds in Iceland and France highlight the presence of four species of avian schistosomes from greylag geese (Anser anser L.): the european nasal species Trichobilharzia regenti and three visceral species, among which an unknown species isolated from blood vessels of the large intestine and liver. Morphological and molecular analyzes of different parasite stages (eggs, adults) revealed new species of Trichobilharzia genus – Trichobilharzia anseri sp. nov. Studies on host-parasite relationship under natural conditions, showed that the life-cycle includes the snail Radix balthica (syn. R. peregra) as intermediate host. The cercariae, already isolated in Iceland from two ponds of the Reykjavik capital area – the Family park and Tjörnin Lake – are the same as those isolated in 1999 by Kolářová et al. during the first study on Icelandic parasitic agents of cercarial dermatitis.