WorldWideScience

Sample records for heterologous hookworm infection

  1. Hookworm infection

    Science.gov (United States)

    ... intestinal wall and suck blood, which results in iron deficiency anemia and protein loss. Adult worms and larvae are ... problems that may result from hookworm infection include: Iron deficiency anemia , caused by loss of blood Nutritional deficiencies Severe ...

  2. Evaluation of Hookworm Infections and Some Haematological ...

    African Journals Online (AJOL)

    ADOWIE PERE

    eosinophilia counts. There was an increase in eosinophilia with high rate of hookworm infection in the age group of 10 – ... Ancylostoma deudenale worldwide (Hotez et al.,. 2003). ... Babamale et al., (2015) reported prevalence of 17.8%.

  3. The diversity and impact of hookworm infections in wildlife

    Directory of Open Access Journals (Sweden)

    Mauricio Seguel

    2017-12-01

    Full Text Available Hookworms are blood-feeding nematodes that parasitize the alimentary system of mammals. Despite their high pathogenic potential, little is known about their diversity and impact in wildlife populations. We conducted a systematic review of the literature on hookworm infections of wildlife and analyzed 218 studies qualitative and quantitatively. At least 68 hookworm species have been described in 9 orders, 24 families, and 111 species of wild mammals. Black bears, red foxes, and bobcats harbored the highest diversity of hookworm species and Ancylostoma pluridentatum, A. tubaeforme, Uncinaria stenocephala and Necator americanus were the hookworm species with the highest host diversity index. Hookworm infections cause anemia, retarded growth, tissue damage, inflammation and significant mortality in several wildlife species. Anemia has been documented more commonly in canids, felids and otariids, and retarded growth only in otariids. Population- level mortality has been documented through controlled studies only in canines and eared seals although sporadic mortality has been noticed in felines, bears and elephants. The main driver of hookworm pathogenic effects was the hookworm biomass in a population, measured as prevalence, mean burden and hookworm size (length. Many studies recorded significant differences in prevalence and mean intensity among regions related to contrasts in local humidity, temperature, and host population density. These findings, plus the ability of hookworms to perpetuate in different host species, create a dynamic scenario where changes in climate and the domestic animal-human-wildlife interface will potentially affect the dynamics and consequences of hookworm infections in wildlife. Keywords: Ancylostoma, Hookworm, Uncinaria, Pathology, Epidemiology, Wildlife

  4. Impact of Plasmodium falciparum and hookworm infections on the ...

    African Journals Online (AJOL)

    abp

    2013-01-18

    Saharan Africa and they increase the prevalence of anaemia in pregnancy with resultant poor pregnancy outcomes. This study was carried out to assess the impact of Plasmodium falciparum and hookworm infections on.

  5. Micronutrient-fortified rice can increase hookworm infection risk

    DEFF Research Database (Denmark)

    de Gier, Brechje; Campos Ponce, Maiza; Perignon, Marlene

    2016-01-01

    or inflammation after iron supplementation. OBJECTIVE: To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. METHODS: A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program....... Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice.......6%, but differed considerably among schools (range 0%- 48.1%).Micronutrient-fortified rice significantly increased risk of new hookworm infection. This effect was modified by baseline hookworm prevalence at the school; hookworm infection risk was increased by all three types of fortified rice in schools where...

  6. [Massive hookworm infection as a cause of intestinal bleeding and severe anemia].

    Science.gov (United States)

    Nair, Gayatri V; Cazorla, Ernesto; Choque, Henry; White, A Clinton; Cabada, Miguel M

    2016-01-01

    Overt gastrointestinal bleeding caused by hookworm infection is rarely reported. We present a 34 year old male with lower gastrointestinal bleeding with evidence of massive hookworm infection on colonoscopy and discuss the need to consider hookworm infection as a possible etiology of gastrointestinal bleed in endemic areas.

  7. High prevalence of Ancylostoma ceylanicum hookworm infections in humans, Cambodia, 2012

    DEFF Research Database (Denmark)

    Inpankaew, Tawin; Schär, Fabian; Dalsgaard, Anders

    2014-01-01

    Ancylostoma ceylanicum, a hookworm of canids and felids in Asia, is becoming the second most common hookworm infecting humans. In 2012, we investigated the prevalence and infection dynamics of and risk factors for hookworm infections in humans and dogs in a rural Cambodian village. Over 57% of th......; thus, we advocate for a One Health approach to control this zoonosis....

  8. Trichuris and hookworm infections associated with anaemia during pregnancy.

    Science.gov (United States)

    Gyorkos, Theresa W; Gilbert, Nicolas L; Larocque, Renée; Casapía, Martín

    2011-04-01

    To assess the following associations between the second and third trimesters of pregnancy: (i) the intensity of soil-transmitted helminth (STH) infection and haemoglobin/anaemia, (ii) the effect of mebendazole treatment on the occurrence of STH infection, and (iii) the effect of mebendazole treatment on haemoglobin/anaemia. Data originated from a trial of 1042 pregnant women recruited in their second trimester and followed to delivery. Baseline assessments included socio-demographic/health information from questionnaires, haemoglobin/anaemia from HemoCue ascertainment of fingerprick blood, and the presence and intensity of STH (Ascaris lumbricoides, hookworms and Trichuris trichiura) infections from Kato-Katz examination. All women were given iron supplements; half were randomly allocated to receive single dose 500 mg mebendazole, and half, placebo. Haemoglobin/anaemia and STH infection status were determined again in the third trimester of pregnancy. Complete information was available from 935 (89.7%) women. Mebendazole significantly reduced the prevalence and intensity of all three STH infections. Higher intensities of hookworm and Trichuris infections in the second trimester were associated with a higher risk of anaemia in the third trimester. Overall, women with moderate/heavy Trichuris infection were found to be at a higher risk of anaemia; the highest risk was observed among those with moderate/heavy hookworm co-infection (adjusted OR = 2.77; 95% CI: 1.26, 6.11). Mebendazole treatment did not reduce the risk of anaemia. Higher intensities of both Trichuris and hookworm infections are associated with anaemia in pregnancy. The importance of Trichuris infections during pregnancy requires renewed attention. © 2011 Blackwell Publishing Ltd.

  9. Peptide-based subunit vaccine against hookworm infection.

    Directory of Open Access Journals (Sweden)

    Mariusz Skwarczynski

    Full Text Available Hookworms infect more people than HIV and malaria combined, predominantly in third world countries. Treatment of infection with chemotherapy can have limited efficacy and re-infections after treatment are common. Heavy infection often leads to debilitating diseases. All these factors suggest an urgent need for development of vaccine. In an attempt to develop a vaccine targeting the major human hookworm, Necator americanus, a B-cell peptide epitope was chosen from the apical enzyme in the hemoglobin digestion cascade, the aspartic protease Na-APR-1. The A(291Y alpha helical epitope is known to induce neutralizing antibodies that inhibit the enzymatic activity of Na-APR-1, thus reducing the capacity for hookworms to digest hemoglobin and obtain nutrients. A(291Y was engineered such that it was flanked on both termini by a coil-promoting sequence to maintain native conformation, and subsequently incorporated into a Lipid Core Peptide (LCP self-adjuvanting system. While A(291Y alone or the chimeric epitope with or without Freund's adjuvants induced negligible IgG responses, the LCP construct incorporating the chimeric peptide induced a strong IgG response in mice. Antibodies produced were able to bind to and completely inhibit the enzymatic activity of Na-APR-1. The results presented show that the new chimeric LCP construct can induce effective enzyme-neutralising antibodies in mice, without the help of any additional toxic adjuvants. This approach offers promise for the development of vaccines against helminth parasites of humans and their livestock and companion animals.

  10. Suppression of inflammatory immune responses in celiac disease by experimental hookworm infection.

    Directory of Open Access Journals (Sweden)

    Henry J McSorley

    Full Text Available We present immunological data from two clinical trials where the effect of experimental human hookworm (Necator americanus infection on the pathology of celiac disease was evaluated. We found that basal production of Interferon- (IFN-γ and Interleukin- (IL-17A from duodenal biopsy culture was suppressed in hookworm-infected participants compared to uninfected controls. Increased levels of CD4+CD25+Foxp3+ cells in the circulation and mucosa are associated with active celiac disease. We show that this accumulation also occurs during a short-term (1 week oral gluten challenge, and that hookworm infection suppressed the increase of circulating CD4+CD25+Foxp3+ cells during this challenge period. When duodenal biopsies from hookworm-infected participants were restimulated with the immunodominant gliadin peptide QE65, robust production of IL-2, IFN-γ and IL-17A was detected, even prior to gluten challenge while participants were strictly adhering to a gluten-free diet. Intriguingly, IL-5 was produced only after hookworm infection in response to QE65. Thus we hypothesise that hookworm-induced TH2 and IL-10 cross-regulation of the TH1/TH17 inflammatory response may be responsible for the suppression of these responses during experimental hookworm infection.

  11. Prevalence of Hookworm infection and Strongyloidiasis in Cats and Potential Risk Factor of Human Diseases

    Science.gov (United States)

    Sedionoto, Blego; Anamnart, Witthaya

    2018-02-01

    Hookworm infection and Stronyloidiasis are public health problem in the worldwide which both of them could infective in human by penetrated on skin and they have potential risk from Gastrointestinal zoonotic helminths of pets, including cats. We investigated the prevalence soil transmitted helminths infection in human and cats used modified Formal-Ether Concentration and agar plate culture. Fecal samples of 23 cats and human from Naitung and Subua Villages (area study 1), and fecal samples of 15 cats and 17 humans from Thasala Beach villages (area study 2) were collected. Result of study in area study 1 showed prevalence of infection in human was not hookworm and strongyloidiasis but 10% humans have infected Ascaris and Tricuris, and in cats have infected by hookworm 75.2% and S. strercoralis 8.5%, toxocara 13%, spirometra 13% and overall prevalence 82.5%. In area study 2 showed in human has infected by Trichuris 100% and S. stercoralis 29.4% and in cats have infected by hookworm 100% and S. strercoralis 40%, toxocora 20%, and spirometra 20%. Helminth infection found in both humans in two areas study are S. strercoralis. Hookworms were the most common helminth in cats but did not connection with infection in human, while S. strercoralis was helminth infection in cats which has potential zoonotic disease to human.

  12. Studies on Ancylostomiasis: 1.An Experimental Study on Hookworm Infection and Anemia

    International Nuclear Information System (INIS)

    Lee, Mun Ho; Kim, Dong Jip; Lee, Jang Kyu; Seo, Byong Sul; Lee, Soon Hyung

    1967-01-01

    In view of its prevalence in the Far East area, a more detailed knowledge on the hookworm infection is one of the very important medical problem. The present study was aimed to determine the infectivity of the artificially hatched ancylosotma duodenale larvae in man after its oral administration, evaluate the clinical symptomatology of such infection, determine the date of first appearance of ova in the stool, calculate the blood loss per worm per day, assess the relation-ships between the ova count, infectivity (worm load), blood loss and severity of anemia. An erythrokinetic study was also done to analyse the characteristics of hookworm anemia by means of 59 Fe and 51 Cr.

  13. Hookworm infection, anaemia and genetic variability of the New Zealand sea lion.

    Science.gov (United States)

    Acevedo-Whitehouse, Karina; Petetti, Laura; Duignan, Padraig; Castinel, Aurelie

    2009-10-07

    Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in the New Zealand sea lion, a threatened otariid that has low levels of genetic variability and high hookworm infection rates. Using a panel of 22 microsatellites, we found that average allelic diversity (5.9) and mean heterozygosity (0.72) were higher than expected for a small population with restricted breeding, and we found no evidence of an association between genetic variability and hookworm resistance. However, similar to what was observed for the California sea lion, homozygosity at a single locus explained the occurrence of anaemia and thrombocytopenia in hookworm-infected pups (generalized linear model, F = 11.81, p < 0.001) and the effect was apparently driven by a particular allele (odds ratio = 34.95%; CI: 7.12-162.41; p < 0.00001). Our study offers further evidence that these haematophagus parasites exert selective pressure on otariid blood-clotting processes.

  14. Strongyloides stercoralis and hookworm co-infection: spatial distribution and determinants in Preah Vihear Province, Cambodia.

    Science.gov (United States)

    Forrer, Armelle; Khieu, Virak; Schär, Fabian; Vounatsou, Penelope; Chammartin, Frédérique; Marti, Hanspeter; Muth, Sinuon; Odermatt, Peter

    2018-01-12

    Strongyloides stercoralis and hookworm are two soil-transmitted helminths (STH) that are highly prevalent in Cambodia. Strongyloides stercoralis causes long-lasting infections and significant morbidity but is largely neglected, while hookworm causes the highest public health burden among STH. The two parasites have the same infection route, i.e. skin penetration. The extent of co-distribution, which could result in potential high co-morbidities, is unknown in highly endemic settings like Cambodia. The aim of this study was to predict the spatial distribution of S. stercoralis-hookworm co-infection risk and to investigate determinants of co-infection in Preah Vihear Province, North Cambodia. A cross-sectional survey was conducted in 2010 in 60 villages of Preah Vihear Province. Diagnosis was performed on two stool samples, using combined Baermann technique and Koga agar culture plate for S. stercoralis and Kato-Katz technique for hookworm. Bayesian multinomial geostatistical models were used to assess demographic, socioeconomic, and behavioural determinants of S. stercoralis-hookworm co-infection and to predict co-infection risk at non-surveyed locations. Of the 2576 participants included in the study, 48.6% and 49.0% were infected with S. stercoralis and hookworm, respectively; 43.8% of the cases were co-infections. Females, preschool aged children, adults aged 19-49 years, and participants who reported regularly defecating in toilets, systematically boiling drinking water and having been treated with anthelmintic drugs had lower odds of co-infection. While S. stercoralis infection risk did not appear to be spatially structured, hookworm mono-infection and co-infection exhibited spatial correlation at about 20 km. Co-infection risk was positively associated with longer walking distances to a health centre and exhibited a small clustering tendency. The association was only partly explained by climatic variables, suggesting a role for underlying factors, such as

  15. Characterising the mucosal and systemic immune responses to experimental human hookworm infection.

    Directory of Open Access Journals (Sweden)

    Soraya Gaze

    2012-02-01

    Full Text Available The mucosal cytokine response of healthy humans to parasitic helminths has never been reported. We investigated the systemic and mucosal cytokine responses to hookworm infection in experimentally infected, previously hookworm naive individuals from non-endemic areas. We collected both peripheral blood and duodenal biopsies to assess the systemic immune response, as well as the response at the site of adult worm establishment. Our results show that experimental hookworm infection leads to a strong systemic and mucosal Th2 (IL-4, IL-5, IL-9 and IL-13 and regulatory (IL-10 and TGF-β response, with some evidence of a Th1 (IFN-γ and IL-2 response. Despite upregulation after patency of both IL-15 and ALDH1A2, a known Th17-inducing combination in inflammatory diseases, we saw no evidence of a Th17 (IL-17 response. Moreover, we observed strong suppression of mucosal IL-23 and upregulation of IL-22 during established hookworm infection, suggesting a potential mechanism by which Th17 responses are suppressed, and highlighting the potential that hookworms and their secreted proteins offer as therapeutics for human inflammatory diseases.

  16. Rapid Detection and Identification of Human Hookworm Infections through High Resolution Melting (HRM) Analysis

    Science.gov (United States)

    Ngui, Romano; Lim, Yvonne A. L.; Chua, Kek Heng

    2012-01-01

    Background Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species. PMID:22844538

  17. Rapid detection and identification of human hookworm infections through high resolution melting (HRM analysis.

    Directory of Open Access Journals (Sweden)

    Romano Ngui

    Full Text Available BACKGROUND: Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR coupled with high resolution melting-curve (HRM analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. METHODS: Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2 of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. CONCLUSION: The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.

  18. The synergistic effect of concomitant schistosomiasis, hookworm, and trichuris infections on children's anemia burden.

    Directory of Open Access Journals (Sweden)

    Amara E Ezeamama

    2008-06-01

    Full Text Available To estimate the degree of synergism between helminth species in their combined effects on anemia.Quantitative egg counts using the Kato-Katz method were determined for Ascaris lumbricoides, hookworm, Trichuris trichiura, and Schistosoma japonicum in 507 school-age children from helminth-endemic villages in The Philippines. Infection intensity was defined in three categories: uninfected, low, or moderate/high (M+. Anemia was defined as hemoglobin <11 g/dL. Logistic regression models were used to estimate odds ratios (OR, 95% confidence intervals (CI, and synergy index for pairs of concurrent infections.M+ co-infection of hookworm and S. japonicum (OR = 13.2, 95% CI: 3.82-45.5 and of hookworm and T. trichiura (OR = 5.34, 95% CI: 1.76-16.2 were associated with higher odds of anemia relative to children without respective M+ co-infections. For co-infections of hookworm and S. japonicum and of T. trichiura and hookworm, the estimated indices of synergy were 2.9 (95% CI: 1.1-4.6 and 1.4 (95% CI: 0.9-2.0, respectively.Co-infections of hookworm and either S. japonicum or T. trichiura were associated with higher levels of anemia than would be expected if the effects of these species had only independent effects on anemia. This suggests that integrated anti-helminthic treatment programs with simultaneous deworming for S. japonicum and some geohelminths could yield a greater than additive benefit for reducing anemia in helminth-endemic regions.

  19. Epidemiology of Hookworm Infection in Kintampo North Municipality, Ghana: Patterns of Malaria Coinfection, Anemia, and Albendazole Treatment Failure

    Science.gov (United States)

    Humphries, Debbie; Mosites, Emily; Otchere, Joseph; Twum, Welbeck Amoani; Woo, Lauren; Jones-Sanpei, Hinckley; Harrison, Lisa M.; Bungiro, Richard D.; Benham-Pyle, Blair; Bimi, Langbong; Edoh, Dominic; Bosompem, Kwabena; Wilson, Michael; Cappello, Michael

    2011-01-01

    A cross-sectional pilot study of hookworm infection was carried out among 292 subjects from 62 households in Kintampo North, Ghana. The overall prevalence of hookworm infection was 45%, peaking in those 11–20 years old (58.5%). In children, risk factors for hookworm infection included coinfection with malaria and increased serum immunoglobulin G reactivity to hookworm secretory antigens. Risk factors for infection in adults included poor nutritional status, not using a latrine, not wearing shoes, and occupation (farming). Although albendazole therapy was associated with an overall egg reduction rate of 82%, 37 subjects (39%) remained infected. Among those who failed therapy, treatment was not associated with a significant reduction in egg excretion, and nearly one-third had higher counts on repeat examination. These data confirm a high prevalence of low-intensity hookworm infection in central Ghana and its association with poor nutritional status. The high rate of albendazole failure raises concern about emerging resistance. PMID:21540391

  20. Vaccination with recombinant aspartic hemoglobinase reduces parasite load and blood loss after hookworm infection in dogs.

    Directory of Open Access Journals (Sweden)

    Alex Loukas

    2005-10-01

    Full Text Available Hookworms infect 730 million people in developing countries where they are a leading cause of intestinal blood loss and iron-deficiency anemia. At the site of attachment to the host, adult hookworms ingest blood and lyse the erythrocytes to release hemoglobin. The parasites subsequently digest hemoglobin in their intestines using a cascade of proteolysis that begins with the Ancylostoma caninum aspartic protease 1, APR-1.We show that vaccination of dogs with recombinant Ac-APR-1 induced antibody and cellular responses and resulted in significantly reduced hookworm burdens (p = 0.056 and fecal egg counts (p = 0.018 in vaccinated dogs compared to control dogs after challenge with infective larvae of A. caninum. Most importantly, vaccinated dogs were protected against blood loss (p = 0.049 and most did not develop anemia, the major pathologic sequela of hookworm disease. IgG from vaccinated animals decreased the catalytic activity of the recombinant enzyme in vitro and the antibody bound in situ to the intestines of worms recovered from vaccinated dogs, implying that the vaccine interferes with the parasite's ability to digest blood.To the best of our knowledge, this is the first report of a recombinant vaccine from a hematophagous parasite that significantly reduces both parasite load and blood loss, and it supports the development of APR-1 as a human hookworm vaccine.

  1. Influence of Schistosoma mansoni and Hookworm Infection Intensities on Anaemia in Ugandan Villages

    NARCIS (Netherlands)

    Chami, Goylette F.; Fenwick, Alan; Bulte, Erwin; Kontoleon, Andreas A.; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2015-01-01

    Background: The association of anaemia with intestinal schistosomiasis and hookworm infections are poorly explored in populations that are not limited to children or pregnant women. Methods: We sampled 1,832 individuals aged 5–90 years from 30 communities in Mayuge District, Uganda. Demographic,

  2. A Survey of Hookworm Infection among Pupils of School Age in Jos ...

    African Journals Online (AJOL)

    acer

    The result showed that 144 of the pupils had hookworm ova in their stool samples. ... difference between the different age groups (P < 0.05), 3 – 6 yrs having the highest infection rate ... seasonal because of the influence of climate ... that this factor could be of serious economic ..... Organization, Technical Report Series.

  3. Hookworm infections among migrant workers in Malaysia: Molecular identification of Necator americanus and Ancylostoma duodenale.

    Science.gov (United States)

    Sahimin, Norhidayu; Lim, Yvonne Ai Lian; Douadi, Benacer; Mohd Khalid, Mohd Khairul Nizam; Wilson, John-James; Behnke, Jerzy M; Mohd Zain, Siti Nursheena

    2017-09-01

    Ongoing urbanisation of the working population as well as cross-border migration of workers particularly into large cities has contributed to the development and growth of urban slums. These deprived areas are conducive for the transmission of intestinal pathogens including hookworm. The aim of this study was to determine both the prevalence and species identity of hookworm infections among the migrant worker community in Malaysia. A total of 388 faecal samples were collected from migrant workers between September 2014 and August 2015, representing workers from five employment sectors: construction, manufacturing, agriculture and plantations, food services and domestic services. Faecal samples were examined by microscopy and positive samples were subjected to molecular analysis. A total of 51 samples (13.1%) were positive by microscopy for hookworm infections. A two-step PCR based method amplifying a fragment of the 28S rRNA-ITS2 region was used to identify infections by Necator americanus and Ancylostoma spp. PCR products positive for Ancylostoma spp. were sequenced bidirectionally, and sequences analysed through BLAST and phylogenetic analysis. Samples containing Ancylostoma duodenale were further characterized by amplification and sequencing a fragment of cytochrome c oxidase subunit 1 (cox1) gene. PCR amplicons were successfully obtained from 42 (82.4%) of 51 samples, with 81.0% (34 of 42) identified as Necator americanus, 16.7% (7 of 42) as Ancylostoma spp. and 2.4% (1 of 42) as mixed infections of both species. All eight Ancylostoma spp. were confirmed to be Ancylostoma duodenale and this is the first time A. duodenale was reported in Malaysia. Samples containing A. duodenale from Nepalese and Indonesian workers shared high-similarity and were distinct compared to sequences from other countries. This study highlights the prevalence of hookworm infections among migrant workers living in Malaysia. Our findings underscore the necessity of screening migrant

  4. Impact of hookworm infection and deworming on anaemia in non-pregnant populations: a systematic review.

    Science.gov (United States)

    Smith, Jennifer L; Brooker, Simon

    2010-07-01

    To summarise age- and intensity-stratified associations between human hookworm infection and anaemia and to quantify the impact of treatment with the benzimidazoles, albendazole and mebendazole, on haemoglobin and anaemia in non-pregnant populations. Electronic databases (MEDLINE, EMBASE, PubMed) were searched for relevant studies published between 1980 and 2009, regardless of language, and researchers contacted about potential data. Haemoglobin concentration (Hb) was compared between uninfected individuals and individuals harbouring hookworm infections of different intensities, expressed as standardised mean differences (SMD) and 95% confidence intervals (CI). Meta-analysis of randomised control trials (RCTs) investigated the impact of treatment on Hb and anaemia. Twenty-three cross-sectional studies, six pre- and post-intervention studies and 14 trials were included. Among cross-sectional studies, moderate- and heavy-intensity hookworm infections were associated with lower Hb in school-aged children, while all levels of infection intensity were associated with lower Hb in adults. Among RCTs using albendazole, impact of treatment corresponded to a 1.89 g/l increase (95%CI: 0.13-3.63) in mean Hb while mebendazole had no impact. There was a positive impact of 2.37 g/l (95%CI: 1.33-3.50) on mean Hb when albendazole was co-administered with praziquantel, but no apparent additional benefit of treatment with benzimidazoles combined with iron supplementation. The mean impact of treatment with benzimidazoles alone on moderate anaemia was small (relative risk (RR) 0.87) with a larger effect when combined with praziquantel (RR 0.61). Anaemia is most strongly associated with moderate and heavy hookworm infection. The impact of anthelmintic treatment is greatest when albendazole is co-administered with praziquantel.

  5. Involvement of Hookworm Co-Infection in the Pathogenesis and Progression of Podoconiosis: Possible Immunological Mechanism

    Directory of Open Access Journals (Sweden)

    Damilare O. Famakinde

    2018-03-01

    Full Text Available Podoconiosis is an endemic, non-infectious, geochemical and non-filarial inflammatory cause of tropical elephantiasis. The immunology of podoconiosis is not yet expressly understood. In spite of this, co-infection and co-morbidity with the infectious, soil-transmitted hookworm disease that causes iron deficiency anemia has been found to be predominant among affected individuals living in co-endemic settings, thus creating a more complex immunological interplay that still has not been investigated. Although deworming and iron-rich nutrient supplementation have been suggested in podoconiosis patients living under resource-poor conditions, and it is thought that hookworm infection may help to suppress inflammatory responses, the undisputed link that exists between a non-infectious and an infectious disease may create a scenario whereby during a co-infection, treatment of one exacerbates the other disease condition or is dampened by the debilitation caused by the other. In this paper, we elaborate on the immunopathogenesis of podoconiosis and examine the possible immunological dynamics of hookworm co-infection in the immunopathology of podoconiosis, with a view toward improved management of the disease that will facilitate its feasible elimination.

  6. Development of a Sensitive and Specific Antigen-Detection System for Strongyloides Stercoralis and Hookworm Infections

    Science.gov (United States)

    1997-06-01

    difficult to specifically identify, and failure to implement the correct antibiotic therapy in a timely fashion can result in the onset of acute symptoms...compromised patients are particularly at risk. Treatment is similar to hookworms. Treatment of nematode infection is fairly standard with therapies using...caninum eggs harvested by floatation in ZnSO 4 solution were similarly processed for PAGE fractionation except that eggs were not homogenized. Figures 13a

  7. Prevalence of Hookworm Infection Among Patients Attending Aminu

    African Journals Online (AJOL)

    DR. AMINU

    The above prevalence rate of infection could become higher in years to come ... majority of the infected individuals live in poverty- ... pregnant women in developing countries are suffering .... Darjeeling, India with 42.8% (Pal et al., 2007),.

  8. Number of Grooming Partners Is Associated with Hookworm Infection in Wild Vervet Monkeys (Chlorocebus aethiops).

    Science.gov (United States)

    Wren, Brandi T; Remis, Melissa J; Camp, Joseph W; Gillespie, Thomas R

    2016-01-01

    There are many known benefits of social grooming among primates, including maintenance of social relationships, removal of ectoparasites, and improved physiological condition. Recently, however, researchers have noted that social grooming and social contact may also present a significant cost by facilitating transmission of some parasites and pathogens. We investigated whether the number of social grooming partners varied based on infection status for gastrointestinal parasites. We used focal animal sampling and continuous recording to collect data on the number of grooming partners for known individual vervet monkeys (Chlorocebus aethiops). We collected non-invasive faecal samples and examined them using faecal flotation, faecal sedimentation, and immunofluorescence microscopy. We detected 6 parasites: Trichuris sp. (92%), hookworm (71%), spirurids (68%), Oesophagostomum sp. (84%), Strongyloides sp. (24%), and Entamoeba coli (92%). The number of grooming partners varied significantly based on infection with hookworm and sex. No significant relationships were detected for other parasites. Associations between host behavioural variation and some parasite taxa (specifically Trichuris, Oesophagostomum, and Entamoeba spp.) were impossible to explore due to an extremely high prevalence among hosts. This is the first report that we are aware of that has detected an association between social grooming behaviours and infection with hookworm. © 2016 S. Karger AG, Basel.

  9. Anemia, malaria and hookworm infections in a Vietnamese ethnic minority

    NARCIS (Netherlands)

    Le Hung, Q.; de Vries, Peter J.; Giao, Phan T.; Binh, Tran Q.; Nam, Nguyen V.; Kager, Piet A.

    2005-01-01

    The aim of this study was to determine the prevalence of anemia and evaluate the relationship of malaria and helminth infections on anemia status in Phan Tien village, a mountainous ethnic minority community in southern Vietnam. This longitudinal study was performed from April 1997 to 2000 by

  10. Helminthiasis: Hookworm Infection Remains a Public Health Problem in Dera District, South Gondar, Ethiopia.

    Directory of Open Access Journals (Sweden)

    Melashu Balew Shiferaw

    Full Text Available Intestinal parasitic infections are significant cause of morbidity and mortality in endemic countries. In Ethiopia, helminthiasis was the third leading cause of outpatient visits. Despite the health extension program was launched to address this problem, there is limited information on the burden of intestinal parasites after implementation of the program in our setting. Therefore, the aim of this study was to assess the intestinal helminthic infections among clients attending at Anbesame health center, South Gondar, Ethiopia.A cross sectional study was conducted at Anbesame health center from March to June 2015. A structured questionnaire was used to collect data from 464 study participants selected consecutively. Stool specimen collection, processing through formol-ether concentration technique and microscopic examination for presence of parasites were carried out. Data were entered, cleaned and analyzed using SPSS Version 20.Among the total 464 study participants with median (±IQR age of 25.0 (±21.75 years, 262 (56.5% were females. Helminthic infection was found in 97 (20.9% participants. Hookworm (68 [14.7%] was the predominant parasite followed by S. mansoni (11 [2.4%], E. vermicularis (9 [1.9%] and S. stercoralis (5 [1.1%]. Patients with age group ≥15 years (AOR: 5.26; 95% CI: 2.05-13.46; P: 0.001 and walking barefoot (AOR: 2.20; 95% CI: 1.08-4.48; P: 0.031 were more vulnerable from the hookworm infections.There was a high burden of hookworm infections in our setting. Hence, regular shoes wearing, considering all age groups in the albendazole deworming as mass treatment and environmental hygiene are important interventions to reduce the burden of such neglected tropical disease.

  11. Helminthiasis: Hookworm Infection Remains a Public Health Problem in Dera District, South Gondar, Ethiopia

    Science.gov (United States)

    Shiferaw, Melashu Balew; Mengistu, Agmas Dessalegn

    2015-01-01

    Background Intestinal parasitic infections are significant cause of morbidity and mortality in endemic countries. In Ethiopia, helminthiasis was the third leading cause of outpatient visits. Despite the health extension program was launched to address this problem, there is limited information on the burden of intestinal parasites after implementation of the program in our setting. Therefore, the aim of this study was to assess the intestinal helminthic infections among clients attending at Anbesame health center, South Gondar, Ethiopia. Methods A cross sectional study was conducted at Anbesame health center from March to June 2015. A structured questionnaire was used to collect data from 464 study participants selected consecutively. Stool specimen collection, processing through formol-ether concentration technique and microscopic examination for presence of parasites were carried out. Data were entered, cleaned and analyzed using SPSS Version 20. Results Among the total 464 study participants with median (±IQR) age of 25.0 (±21.75) years, 262 (56.5%) were females. Helminthic infection was found in 97 (20.9%) participants. Hookworm (68 [14.7%]) was the predominant parasite followed by S. mansoni (11 [2.4%]), E. vermicularis (9 [1.9%]) and S. stercoralis (5 [1.1%]). Patients with age group ≥15 years (AOR: 5.26; 95% CI: 2.05–13.46; P: 0.001) and walking barefoot (AOR: 2.20; 95% CI: 1.08–4.48; P: 0.031) were more vulnerable from the hookworm infections. Conclusions There was a high burden of hookworm infections in our setting. Hence, regular shoes wearing, considering all age groups in the albendazole deworming as mass treatment and environmental hygiene are important interventions to reduce the burden of such neglected tropical disease. PMID:26657490

  12. Helminthiasis: Hookworm Infection Remains a Public Health Problem in Dera District, South Gondar, Ethiopia.

    Science.gov (United States)

    Shiferaw, Melashu Balew; Mengistu, Agmas Dessalegn

    2015-01-01

    Intestinal parasitic infections are significant cause of morbidity and mortality in endemic countries. In Ethiopia, helminthiasis was the third leading cause of outpatient visits. Despite the health extension program was launched to address this problem, there is limited information on the burden of intestinal parasites after implementation of the program in our setting. Therefore, the aim of this study was to assess the intestinal helminthic infections among clients attending at Anbesame health center, South Gondar, Ethiopia. A cross sectional study was conducted at Anbesame health center from March to June 2015. A structured questionnaire was used to collect data from 464 study participants selected consecutively. Stool specimen collection, processing through formol-ether concentration technique and microscopic examination for presence of parasites were carried out. Data were entered, cleaned and analyzed using SPSS Version 20. Among the total 464 study participants with median (±IQR) age of 25.0 (±21.75) years, 262 (56.5%) were females. Helminthic infection was found in 97 (20.9%) participants. Hookworm (68 [14.7%]) was the predominant parasite followed by S. mansoni (11 [2.4%]), E. vermicularis (9 [1.9%]) and S. stercoralis (5 [1.1%]). Patients with age group ≥15 years (AOR: 5.26; 95% CI: 2.05-13.46; P: 0.001) and walking barefoot (AOR: 2.20; 95% CI: 1.08-4.48; P: 0.031) were more vulnerable from the hookworm infections. There was a high burden of hookworm infections in our setting. Hence, regular shoes wearing, considering all age groups in the albendazole deworming as mass treatment and environmental hygiene are important interventions to reduce the burden of such neglected tropical disease.

  13. Hookworm Infection among School Age Children in Kintampo North Municipality, Ghana: Nutritional Risk Factors and Response to Albendazole Treatment

    Science.gov (United States)

    Humphries, Debbie; Simms, Benjamin T.; Davey, Dylan; Otchere, Joseph; Quagraine, Josephine; Terryah, Shawn; Newton, Samuel; Berg, Elyssa; Harrison, Lisa M.; Boakye, Daniel; Wilson, Michael; Cappello, Michael

    2013-01-01

    Children (n = 812) 6–11 years of age attending 16 schools in the Kintampo North Municipality of Ghana were screened for participation in a study on hookworm infection, nutrition, and response to albendazole. The prevalence of Necator americanus hookworm infection (n = 286) was 39.1%, and significant predictors of infection included age, malaria parasitemia, lack of health care, school area, levels of antibodies against hookworm, and low consumption of animal foods. The cure rate after a single dose (400 mg) albendazole was 43%, and the mean fecal egg count reduction rate was 87.3%. Data for an in vitro egg hatch assay showed a trend toward reduced albendazole susceptibility in post-treatment hookworm isolates (P = 0.06). In summary, hookworm infection is prevalent among school age children in the Kintampo North Municipality and animal food intake inversely correlates with infection status. Modest cure rates and fecal egg count reduction rates reinforce the need for further investigation of potential benzimidazole resistance in Ghana. PMID:23836564

  14. Bayesian risk maps for Schistosoma mansoni and hookworm mono-infections in a setting where both parasites co-exist

    Directory of Open Access Journals (Sweden)

    Giovanna Raso

    2007-11-01

    Full Text Available There is growing interest in the use of Bayesian geostatistical models for predicting the spatial distribution of parasitic infections, including hookworm, Schistosoma mansoni and co-infections with both parasites. The aim of this study was to predict the spatial distribution of mono-infections with either hookworm or S. mansoni in a setting where both parasites co-exist. School-based cross-sectional parasitological and questionnaire surveys were carried out in 57 rural schools in the Man region, western Côte d’Ivoire. A single stool specimen was obtained from each schoolchild attending grades 3-5. Stool specimens were processed by the Kato-Katz technique and an ether concentration method and examined for the presence of hookworm and S. mansoni eggs. The combined results from the two diagnostic approaches were considered for the infection status of each child. Demographic data (i.e. age and sex were obtained from readily available school registries. Each child’s socio-economic status was estimated, using the questionnaire data following a household-based asset approach. Environmental data were extracted from satellite imagery. The different data sources were incorporated into a geographical information system. Finally, a Bayesian spatial multinomial regression model was constructed and the spatial patterns of S. mansoni and hookworm mono-infections were investigated using Bayesian kriging. Our approach facilitated the production of smooth risk maps for hookworm and S. mansoni mono-infections that can be utilized for targeting control interventions. We argue that in settings where S. mansoni and hookworm co-exist and control efforts are under way, there is a need for both mono- and co-infection risk maps to enhance the cost-effectiveness of control programmes.

  15. The associations between water and sanitation and hookworm infection using cross-sectional data from Togo's national deworming program.

    Science.gov (United States)

    Baker, Julia M; Trinies, Victoria; Bronzan, Rachel N; Dorkenoo, Ameyo M; Garn, Joshua V; Sognikin, Sêvi; Freeman, Matthew C

    2018-03-01

    Sustainable control of soil-transmitted helminths requires a combination of chemotherapy treatment and environmental interventions, including access to safe drinking water, sufficient water for hygiene, use of clean sanitation facilities, and handwashing (WASH). We quantified associations between home-, school-, and community-level WASH characteristics and hookworm infection-both prevalence and eggs per gram of stool (intensity)-among Togolese school children in the context of community-based chemotherapy treatments administered in the country from 2010 through 2014. We analyzed data from two surveys conducted by the Togo Ministry of Health: a school-based survey of students aged 6-9 years across Togo conducted in 2009 and a follow-up survey in 2015, after four to five years of preventive chemotherapy. Data were available for 16,473 students attending 1,129 schools in 2009 and for 16,890 students from 1,126 schools in 2015. Between surveys, children in study schools received 0 to 8 rounds of deworming chemotherapy treatments. Few WASH conditions (only unimproved drinking water) were found to be significantly associated with the presence or absence of hookworms in an individual; however, quantitative eggs per gram of feces was associated with availability of unimproved drinking water, availability of improved drinking water either on or off school grounds, having a handwashing station with water available, and access to a sex-separate non-private or private latrine. The association between school WASH conditions and hookworm infection or burden often depended on the 2009 prevalence of infection, as more WASH characteristics were found to be significant predictors of infection among schools with high underlying endemicity of hookworm. Our findings emphasize the complex and often inconsistent or unpredictable relationship between WASH and hookworm. Specifically, we found that while preventive chemotherapy appeared to dramatically reduce hookworm infection, WASH was

  16. Upper respiratory tract infection, heterologous immunisation and meningococcal disease

    NARCIS (Netherlands)

    Scholten, R. J.; Bijlmer, H. A.; Tobi, H.; Dankert, J.; Bouter, L. M.

    1999-01-01

    To test the hypothesis that an episode of upper respiratory tract infection or heterologous immunisation is a predisposing factor for the occurrence of meningococcal disease, data from 377 cases of meningococcal disease and their household contacts (n = 1124) were analysed by conditional logistic

  17. The Study on the Ferrokinetics and Acquired Immunity in Repeated Hookworm Infections

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mun Ho; Lee, Pyl Ung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1967-09-15

    In order to confirm whether acquired immunity or resistance can be developed by the repeated hookworm infections, the 150 mature actively moving filariform ancylostoma duodenale larvae obtained from the severe hookworm anemia patients were orally given to 8 healthy volunteers in three divided doses, 50 in each, at 5 day interval. Also the hematological changes as well as several ferrokinetics using {sup 59}Fe were done and were compared with 10 controls. The clinical symptoms and signs were checked every day for the first 3 weeks and then twice weekly until the end of the experiment. The appearance of the ova in the stool was examined by the formalin ether method and the ova was counted by the Stoll's method. The following laboratory tests were done:1) Red blood cell count, venous blood hematocrit (micromethod), hemoglobin count (cyanomethemoglobin method) were checked every 5 to 7 day interval. 2) Plasma iron concentration (Barkan's modified method) was determined every 2 to 3 week interval. 3) Radioisotope studies:a) Ferrokinetics: Huff et al and Bothwell's method were applied. Erythropoietic Index (% of normal)= ['Subject's turnover/100 ml whole bloodX100'] over ['Average normal turnover/100 ml whole blood'] b) Quantitative measurement of the gastrointestinal absorption of iron:Radioiron ({sup 59}Fe) balance method was applied. c) Determination of the plasma erythropoietin activity: Fried's method was applied. Following were the results: 1) The serum iron level was lower. The red cell volume was decreased, but with relative increase of plasma volume. 2) The plasma iron disappearance time was accelerated and the plasma iron turnover rate was decreased. The red cell iron turnover rate was markedly increased, while all of the red cell iron concentration, circulating red cell iron, plasma iron pool were decreased. The daily iron pool turnover and red cell renewal rate were increased. 3) The erythropoietic index, erythropoietin activity and intestinal absorption of

  18. The Study on the Ferrokinetics and Acquired Immunity in Repeated Hookworm Infections

    International Nuclear Information System (INIS)

    Lee, Mun Ho; Lee, Pyl Ung

    1967-01-01

    In order to confirm whether acquired immunity or resistance can be developed by the repeated hookworm infections, the 150 mature actively moving filariform ancylostoma duodenale larvae obtained from the severe hookworm anemia patients were orally given to 8 healthy volunteers in three divided doses, 50 in each, at 5 day interval. Also the hematological changes as well as several ferrokinetics using 59 Fe were done and were compared with 10 controls. The clinical symptoms and signs were checked every day for the first 3 weeks and then twice weekly until the end of the experiment. The appearance of the ova in the stool was examined by the formalin ether method and the ova was counted by the Stoll's method. The following laboratory tests were done:1) Red blood cell count, venous blood hematocrit (micromethod), hemoglobin count (cyanomethemoglobin method) were checked every 5 to 7 day interval. 2) Plasma iron concentration (Barkan's modified method) was determined every 2 to 3 week interval. 3) Radioisotope studies:a) Ferrokinetics: Huff et al and Bothwell's method were applied. Erythropoietic Index (% of normal)= [ S ubject's turnover/100 ml whole bloodX100 ] over [ A verage normal turnover/100 ml whole blood ] b) Quantitative measurement of the gastrointestinal absorption of iron:Radioiron ( 59 Fe) balance method was applied. c) Determination of the plasma erythropoietin activity: Fried's method was applied. Following were the results: 1) The serum iron level was lower. The red cell volume was decreased, but with relative increase of plasma volume. 2) The plasma iron disappearance time was accelerated and the plasma iron turnover rate was decreased. The red cell iron turnover rate was markedly increased, while all of the red cell iron concentration, circulating red cell iron, plasma iron pool were decreased. The daily iron pool turnover and red cell renewal rate were increased. 3) The erythropoietic index, erythropoietin activity and intestinal absorption of iron

  19. Hookworm infection, anaemia and genetic variability of the New Zealand sea lion

    OpenAIRE

    Acevedo-Whitehouse, Karina; Petetti, Laura; Duignan, Padraig; Castinel, Aurelie

    2009-01-01

    Hookworms are intestinal blood-feeding nematodes that parasitize and cause high levels of mortality in a wide range of mammals, including otariid pinnipeds. Recently, an empirical study showed that inbreeding (assessed by individual measures of multi-locus heterozygosity) is associated with hookworm-related mortality of California sea lions. If inbreeding increases susceptibility to hookworms, effects would expectedly be stronger in small, fragmented populations. We tested this assumption in ...

  20. Effect of hookworm infection on wheat challenge in celiac disease--a randomised double-blinded placebo controlled trial.

    Directory of Open Access Journals (Sweden)

    A James Daveson

    Full Text Available BACKGROUND AND AIMS: The association between hygiene and prevalence of autoimmune disease has been attributed in part to enteric helminth infection. A pilot study of experimental infection with the hookworm Necator americanus was undertaken among a group of otherwise healthy people with celiac disease to test the potential of the helminth to suppress the immunopathology induced by gluten. METHODS: In a 21-week, double-blinded, placebo-controlled study, we explored the effects of N. americanus infection in 20 healthy, helminth-naïve adults with celiac disease well controlled by diet. Staged cutaneous inoculations with 10 and 5 infective 3(rd stage hookworm larvae or placebo were performed at week-0 and -12 respectively. At week-20, a five day oral wheat challenge equivalent to 16 grams of gluten per day was undertaken. Primary outcomes included duodenal Marsh score and quantification of the immunodominant α-gliadin peptide (QE65-specific systemic interferon-γ-producing cells by ELISpot pre- and post-wheat challenge. RESULTS: Enteric colonisation with hookworm established in all 10 cases, resulting in transiently painful enteritis in 5. Chronic infection was asymptomatic, with no effect on hemoglobin levels. Although some duodenal eosinophilia was apparent, hookworm-infected mucosa retained a healthy appearance. In both groups, wheat challenge caused deterioration in both primary and several secondary outcomes. CONCLUSIONS: Experimental N. americanus infection proved to be safe and enabled testing its effect on a range of measures of the human autoimmune response. Infection imposed no obvious benefit on pathology. TRIAL REGISTRATION: ClinicalTrials.gov NCT00671138.

  1. Hookworm infection and environmental factors in mbeya region, Tanzania: a cross-sectional, population-based study.

    Directory of Open Access Journals (Sweden)

    Helene Riess

    Full Text Available BACKGROUND: Hookworm disease is one of the most common infections and cause of a high disease burden in the tropics and subtropics. Remotely sensed ecological data and model-based geostatistics have been used recently to identify areas in need for hookworm control. METHODOLOGY: Cross-sectional interview data and stool samples from 6,375 participants from nine different sites in Mbeya region, south-western Tanzania, were collected as part of a cohort study. Hookworm infection was assessed by microscopy of duplicate Kato-Katz thick smears from one stool sample from each participant. A geographic information system was used to obtain remotely sensed environmental data such as land surface temperature (LST, vegetation cover, rainfall, and elevation, and combine them with hookworm infection data and with socio-demographic and behavioral data. Uni- and multivariable logistic regression was performed on sites separately and on the pooled dataset. PRINCIPAL FINDINGS: Univariable analyses yielded significant associations for all ecological variables. Five ecological variables stayed significant in the final multivariable model: population density (odds ratio (OR = 0.68; 95% confidence interval (CI = 0.63-0.73, mean annual vegetation density (OR = 0.11; 95% CI = 0.06-0.18, mean annual LST during the day (OR = 0.81; 95% CI = 0.75-0.88, mean annual LST during the night (OR = 1.54; 95% CI = 1.44-1.64, and latrine coverage in household surroundings (OR = 1.02; 95% CI = 1.01-1.04. Interaction terms revealed substantial differences in associations of hookworm infection with population density, mean annual enhanced vegetation index, and latrine coverage between the two sites with the highest prevalence of infection. CONCLUSION/SIGNIFICANCE: This study supports previous findings that remotely sensed data such as vegetation indices, LST, and elevation are strongly associated with hookworm prevalence. However, the results

  2. The Human Hookworm Vaccine.

    Science.gov (United States)

    Hotez, Peter J; Diemert, David; Bacon, Kristina M; Beaumier, Coreen; Bethony, Jeffrey M; Bottazzi, Maria Elena; Brooker, Simon; Couto, Artur Roberto; Freire, Marcos da Silva; Homma, Akira; Lee, Bruce Y; Loukas, Alex; Loblack, Marva; Morel, Carlos Medicis; Oliveira, Rodrigo Correa; Russell, Philip K

    2013-04-18

    Hookworm infection is one of the world's most common neglected tropical diseases and a leading cause of iron deficiency anemia in low- and middle-income countries. A Human Hookworm Vaccine is currently being developed by the Sabin Vaccine Institute and is in phase 1 clinical testing. The candidate vaccine is comprised of two recombinant antigens known as Na-GST-1 and Na-APR-1, each of which is an important parasite enzyme required for hookworms to successfully utilize host blood as a source of energy. The recombinant proteins are formulated on Alhydrogel(®) and are being tested in combination with a synthetic Toll-like receptor 4 agonist. The aim of the vaccine is to induce anti-enzyme antibodies that will reduce both host blood loss and the number of hookworms attached to the gut. Transfer of the manufacturing technology to the Oswaldo Cruz Foundation (FIOCRUZ)/Bio-Manguinhos (a Brazilian public sector developing country vaccine manufacturer) is planned, with a clinical development plan that could lead to registration of the vaccine in Brazil. The vaccine would also need to be introduced in the poorest regions of Africa and Asia, where hookworm infection is highly endemic. Ultimately, the vaccine could become an essential tool for achieving hookworm control and elimination, a key target in the 2012 London Declaration on Neglected Tropical Diseases. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Association between anaemia and infections (HIV, malaria and hookworm) among children admitted at Muhimbili National Hospital.

    Science.gov (United States)

    Magesa, A S; Magesa, P M

    2012-09-01

    Anaemia is the major cause of morbidity and mortality in paediatric age with much aetiology. The magnitude of childhood anaemia has been inadequately studied at Muhimbili National Hospital (MNH). The study was aimed at determining the frequency of anaemia and associated infections in patients admitted in general paediatric wards at MNH in Dar es Salaam. This was a descriptive cross-sectional study. This was conducted at MNH in general paediatric wards from 20th August, 2009 to 15th December, 2009. Patients, aged 1-84 months, consecutively admitted were recruited in the study. After informed verbal consent from the guardian or parent was obtained, information on demographic and clinical characteristics was collected from the parent or guardian. Physical examination and laboratory tests on blood ; stool samples for hookworm screening; blood slides for malaria parasites; Human Immunodeficiency Virus (HIV) screening; and blood peripheral smears were done on all subjects. Additional information was taken from medical files. Data management: The prevalence of anemia was determined as a percentage of all paediatric patients recruited during the time of data collection. All information was recorded using questionnaires and analysis was done using SPSS version 13.0. A p value of 1.0, p > 0.05). Anaemia in paediatric patients admitted at MNH is a disease of high public health importance in Dar es Salaam and may well carry a high burden in the rest of the country. Other risk factors of anaemia should be investigated with a goal of reducing the burden of anaemia.

  4. Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples

    OpenAIRE

    Mugambi, Robert Muriuki; Agola, Eric L.; Mwangi, Ibrahim N.; Kinyua, Johnson; Shiraho, Esther Andia; Mkoji, Gerald M.

    2015-01-01

    Background Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in ...

  5. Low efficacy of single-dose albendazole and mebendazole against hookworm and effect on concomitant helminth infection in Lao PDR.

    Directory of Open Access Journals (Sweden)

    Phonepasong Ayé Soukhathammavong

    2012-01-01

    Full Text Available BACKGROUND: Albendazole and mebendazole are increasingly deployed for preventive chemotherapy targeting soil-transmitted helminth (STH infections. We assessed the efficacy of single oral doses of albendazole (400 mg and mebendazole (500 mg for the treatment of hookworm infection in school-aged children in Lao PDR. Since Opisthorchis viverrini is co-endemic in our study setting, the effect of the two drugs could also be determined against this liver fluke. METHODOLOGY: We conducted a randomized, open-label, two-arm trial. In total, 200 children infected with hookworm (determined by quadruplicate Kato-Katz thick smears derived from two stool samples were randomly assigned to albendazole (n=100 and mebendazole (n=100. Cure rate (CR; percentage of children who became egg-negative after treatment, and egg reduction rate (ERR; reduction in the geometric mean fecal egg count at treatment follow-up compared to baseline at 21-23 days posttreatment were used as primary outcome measures. Adverse events were monitored 3 hours post treatment. PRINCIPAL FINDINGS: Single-dose albendazole and mebendazole resulted in CRs of 36.0% and 17.6% (odds ratio: 0.4; 95% confidence interval: 0.2-0.8; P=0.01, and ERRs of 86.7% and 76.3%, respectively. In children co-infected with O. viverrini, albendazole and mebendazole showed low CRs (33.3% and 24.2%, respectively and moderate ERRs (82.1% and 78.2%, respectively. CONCLUSIONS/SIGNIFICANCE: Both albendazole and mebendazole showed disappointing CRs against hookworm, but albendazole cured infection and reduced intensity of infection with a higher efficacy than mebendazole. Single-dose administrations showed an effect against O. viverrini, and hence it will be interesting to monitor potential ancillary benefits of a preventive chemotherapy strategy that targets STHs in areas where opisthorchiasis is co-endemic. CLINICAL TRIAL REGISTRATION: Current Controlled Trials ISRCTN29126001.

  6. Low Efficacy of Single-Dose Albendazole and Mebendazole against Hookworm and Effect on Concomitant Helminth Infection in Lao PDR

    Science.gov (United States)

    Soukhathammavong, Phonepasong Ayé; Sayasone, Somphou; Phongluxa, Khampheng; Xayaseng, Vilavanh; Utzinger, Jürg; Vounatsou, Penelope; Hatz, Christoph; Akkhavong, Kongsap; Keiser, Jennifer; Odermatt, Peter

    2012-01-01

    Background Albendazole and mebendazole are increasingly deployed for preventive chemotherapy targeting soil-transmitted helminth (STH) infections. We assessed the efficacy of single oral doses of albendazole (400 mg) and mebendazole (500 mg) for the treatment of hookworm infection in school-aged children in Lao PDR. Since Opisthorchis viverrini is co-endemic in our study setting, the effect of the two drugs could also be determined against this liver fluke. Methodology We conducted a randomized, open-label, two-arm trial. In total, 200 children infected with hookworm (determined by quadruplicate Kato-Katz thick smears derived from two stool samples) were randomly assigned to albendazole (n = 100) and mebendazole (n = 100). Cure rate (CR; percentage of children who became egg-negative after treatment), and egg reduction rate (ERR; reduction in the geometric mean fecal egg count at treatment follow-up compared to baseline) at 21–23 days posttreatment were used as primary outcome measures. Adverse events were monitored 3 hours post treatment. Principal Findings Single-dose albendazole and mebendazole resulted in CRs of 36.0% and 17.6% (odds ratio: 0.4; 95% confidence interval: 0.2–0.8; P = 0.01), and ERRs of 86.7% and 76.3%, respectively. In children co-infected with O. viverrini, albendazole and mebendazole showed low CRs (33.3% and 24.2%, respectively) and moderate ERRs (82.1% and 78.2%, respectively). Conclusions/Significance Both albendazole and mebendazole showed disappointing CRs against hookworm, but albendazole cured infection and reduced intensity of infection with a higher efficacy than mebendazole. Single-dose administrations showed an effect against O. viverrini, and hence it will be interesting to monitor potential ancillary benefits of a preventive chemotherapy strategy that targets STHs in areas where opisthorchiasis is co-endemic. Clinical Trial Registration Current Controlled Trials ISRCTN29126001 PMID:22235353

  7. Zoonotic Hookworm FAQs

    Science.gov (United States)

    ... larva migrans. What are the clinical manifestations of animal (zoonotic) hookworm in people? Cutaneous larval migrans (CLM) in a person's foot. ... and larvae may be found in dirt where animals have been. People may become infected while walking barefoot or when ...

  8. Heterologous Infection of Pregnant Mice Induces Low Birth Weight and Modifies Offspring Susceptibility to Malaria.

    Directory of Open Access Journals (Sweden)

    Ankur Sharma

    Full Text Available Pregnancy malaria (PM is associated with poor pregnancy outcomes, and can arise due to relapse, recrudescence or a re-infection with heterologous parasites. We have used the Plasmodium chabaudi model of pregnancy malaria in C57BL/6 mice to examine recrudescence and heterologous infection using CB and AS parasite strains. After an initial course of patent parasitemia and first recrudescence, CB but not AS parasites were observed to recrudesce again in most animals that became pregnant. Pregnancy exacerbated heterologous CB infection of AS-experienced mice, leading to mortality and impaired post-natal growth of pups. Parasites were detected in placental blood without evidence of sequestration, unlike P. falciparum but similar to other malaria species that infect pregnant women. Inflammatory cytokine levels were elevated in pregnant females during malaria, and associated with intensity of infection and with poor outcomes. Pups born to dams during heterologous infection were more resistant to malaria infections at 6-7 weeks of age, compared to pups born to malaria-experienced but uninfected dams or to malaria-naïve dams. In summary, our mouse model reproduces several features of human PM, including recrudescences, heterologous infections, poor pregnancy outcomes associated with inflammatory cytokines, and modulation of offspring susceptibility to malaria. This model should be further studied to explore mechanisms underlying PM pathogenesis.

  9. Past Life and Future Effects—How Heterologous Infections Alter Immunity to Influenza Viruses

    Directory of Open Access Journals (Sweden)

    Aisha Souquette

    2018-05-01

    Full Text Available Influenza virus frequently mutates due to its error-prone polymerase. This feature contributes to influenza virus’s ability to evade pre-existing immunity, leading to annual epidemics and periodic pandemics. T cell memory plays a key protective role in the face of an antigenically distinct influenza virus strain because T cell targets are often derived from conserved internal proteins, whereas humoral immunity targets are often sites of increased mutation rates that are tolerated by the virus. Most studies of influenza T cell memory are conducted in naive, specific pathogen free mice and do not account for repetitive influenza infection throughout a lifetime, sequential acute heterologous infections between influenza infections, or heterologous chronic co-infections. By contrast to these mouse models, humans often experience numerous influenza infections, encounter heterologous acute infections between influenza infections, and are infected with at least one chronic virus. In this review, we discuss recent advances in understanding the effects of heterologous infections on the establishment and maintenance of CD8+ T cell immunological memory. Understanding the various factors that affect immune memory can provide insights into the development of more effective vaccines and increase reproducibility of translational studies between animal models and clinical results.

  10. Combination of five diagnostic tests to estimate the prevalence of hookworm infection among school-aged children from a rural area of colombia.

    Science.gov (United States)

    Barreto, Rafael E; Narváez, Javier; Sepúlveda, Natalia A; Velásquez, Fabián C; Díaz, Sandra C; López, Myriam Consuelo; Reyes, Patricia; Moncada, Ligia I

    2017-09-01

    Public health programs for the control of soil-transmitted helminthiases require valid diagnostic tests for surveillance and parasitic control evaluation. However, there is currently no agreement about what test should be used as a gold standard for the diagnosis of hookworm infection. Still, in presence of concurrent data for multiple tests it is possible to use statistical models to estimate measures of test performance and prevalence. The aim of this study was to estimate the diagnostic accuracy of five parallel tests (direct microscopic examination, Kato-Katz, Harada-Mori, modified Ritchie-Frick, and culture in agar plate) to detect hookworm infections in a sample of school-aged children from a rural area in Colombia. We used both, a frequentist approach, and Bayesian latent class models to estimate the sensitivity and specificity of five tests for hookworm detection, and to estimate the prevalence of hookworm infection in absence of a Gold Standard. The Kato-Katz and agar plate methods had an overall agreement of 95% and kappa coefficient of 0.76. Different models estimated a sensitivity between 76% and 92% for the agar plate technique, and 52% to 87% for the Kato-Katz technique. The other tests had lower sensitivity. All tests had specificity between 95% and 98%. The prevalence estimated by the Kato-Katz and Agar plate methods for different subpopulations varied between 10% and 14%, and was consistent with the prevalence estimated from the combination of all tests. The Harada-Mori, Ritchie-Frick and direct examination techniques resulted in lower and disparate prevalence estimates. Bayesian approaches assuming imperfect specificity resulted in lower prevalence estimates than the frequentist approach. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Estimating sensitivity of the Kato-Katz technique for the diagnosis of Schistosoma mansoni and hookworm in relation to infection intensity.

    Directory of Open Access Journals (Sweden)

    Oliver Bärenbold

    2017-10-01

    Full Text Available The Kato-Katz technique is the most widely used diagnostic method in epidemiologic surveys and drug efficacy trials pertaining to intestinal schistosomiasis and soil-transmitted helminthiasis. However, the sensitivity of the technique is low, particularly for the detection of light-intensity helminth infections. Examination of multiple stool samples reduces the diagnostic error; yet, most studies rely on a single Kato-Katz thick smear, thus underestimating infection prevalence. We present a model which estimates the sensitivity of the Kato-Katz technique in Schistosoma mansoni and hookworm, as a function of infection intensity for repeated stool sampling and provide estimates of the age-dependent 'true' prevalence. We find that the sensitivity for S. mansoni diagnosis is dominated by missed light infections, which have a low probability to be diagnosed correctly even through repeated sampling. The overall sensitivity strongly depends on the mean infection intensity. In particular at an intensity of 100 eggs per gram of stool (EPG, we estimate a sensitivity of 50% and 80% for one and two samples, respectively. At an infection intensity of 300 EPG, we estimate a sensitivity of 62% for one sample and 90% for two samples. The sensitivity for hookworm diagnosis is dominated by day-to-day variation with typical values for one, two, three, and four samples equal to 50%, 75%, 85%, and 95%, respectively, while it is only weakly dependent on the mean infection intensity in the population. We recommend taking at least two samples and estimate the 'true' prevalence of S. mansoni considering the dependence of the sensitivity on the mean infection intensity and the 'true' hookworm prevalence by taking into account the sensitivity given in the current study.

  12. Cognitive performance and iron status are negatively associated with hookworm infection in Cambodian schoolchildren

    DEFF Research Database (Denmark)

    Khov, Kuong; Fiorentino, Marion; Perignon, Marlene

    2016-01-01

    Soil-transmitted helminth (STH) infection has been associated with lower cognitive performance of schoolchildren. To identify pathways through which STH infection might affect school performance, baseline data from a large rice-fortification trial in Cambodian schoolchildren were used to investig...

  13. Epidemiology of hookworm (Uncinaria spp.) infection in New Zealand (Hooker's) sea lion (Phocarctos hookeri) pups on Enderby Island, Auckland Islands (New Zealand) during the breeding seasons from 1999/2000 to 2004/2005.

    Science.gov (United States)

    Castinel, A; Duignan, P J; Lyons, E T; Pomroy, W E; Gibbs, N; López-Villalobos, N; Chilvers, B L; Wilkinson, I S

    2007-06-01

    This is the first investigation of the epidemiology of hookworm (Uncinaria spp.) infection in New Zealand sea lions (NZSLs; Phocarctos hookeri) on Enderby Island, Auckland Islands. The examination of faeces for hookworm eggs in various age categories of sea lions revealed that only pups up to at least 3 months of age harboured adult hookworms in their intestines. Gross necropsy of more than 400 pups from 1999/2000 to 2004/2005 showed that the prevalence of hookworm infection varied significantly between years and was higher from mid-January to the end of February when the majority of pups were between 3 and 9 weeks old. The average burden of adult parasites per pup was not influenced by the host's sex and body condition or by year. This study also provided evidence for transmission occurring by the transmammary route in NZSLs.

  14. Randomized, controlled, assessor-blind clinical trial to assess the efficacy of single- versus repeated-dose albendazole to treat ascaris lumbricoides, trichuris trichiura, and hookworm infection.

    Science.gov (United States)

    Adegnika, Ayola A; Zinsou, Jeannot F; Issifou, Saadou; Ateba-Ngoa, Ulysse; Kassa, Roland F; Feugap, Eliane N; Honkpehedji, Yabo J; Dejon Agobe, Jean-Claude; Kenguele, Hilaire M; Massinga-Loembe, Marguerite; Agnandji, Selidji T; Mordmüller, Benjamin; Ramharter, Michael; Yazdanbakhsh, Maria; Kremsner, Peter G; Lell, Bertrand

    2014-05-01

    In many regions where soil-transmitted helminth infections are endemic, single-dose albendazole is used in mass drug administration programs to control infections. There are little data on the efficacy of the standard single-dose administration compared to that of alternative regimens. We conducted a randomized, controlled, assessor-blinded clinical trial to determine the efficacies of standard and extended albendazole treatment against soil-transmitted helminth infection in Gabon. A total of 175 children were included. Adequate cure rates and egg reduction rates above 85% were found with a single dose of albendazole for Ascaris infection, 85% (95% confidence interval [CI], 73, 96) and 93.8% (CI, 87.6, 100), respectively, while two doses were necessary for hookworm infestation (92% [CI, 78, 100] and 92% [CI, 78, 100], respectively). However, while a 3-day regimen was not sufficient to cure Trichuris (cure rate, 83% [CI, 73, 93]), this regimen reduced the number of eggs up to 90.6% (CI, 83.1, 100). The rate ratios of two- and three-dose regimens compared to a single-dose treatment were 1.7 (CI, 1.1, 2.5) and 2.1 (CI, 1.5, 2.9) for Trichuris and 1.7 (CI, 1.0, 2.9) and 1.7 (CI, 1.0, 2.9) for hookworm. Albendazole was safe and well tolerated in all regimens. A single-dose albendazole treatment considerably reduces Ascaris infection but has only a moderate effect on hookworm and Trichuris infections. The single-dose option may still be the preferred regimen because it balances efficacy, safety, and compliance during mass drug administration, keeping in mind that asymptomatic low-level helminth carriage may also have beneficial effects. (This study has been registered at ClinicalTrials.gov under registration number NCT01192802.).

  15. Ultrastructural study on experimental infection of rotavirus in a murine heterologous model

    Directory of Open Access Journals (Sweden)

    Selma Majerowicz

    1994-09-01

    Full Text Available Viral replication, histopathological and ultrastructural changes were observed for a period of nine days in the small intestine of suckling mice infected with a simian rotavirus (SA11. Samples taken from duodenum, jejunun and ileum were prepared for light microscopy, transmission and scanning electron microscopy analysis. Histopathologic effect could be detected within 8 hr post-infection, when only a few altered cells were observed. Damage was extensive after 16 hr post-infection, showing swollen enterocytes and reduced and irregularly oriented microvilli at intestinal villi tips. Virus particles were detected at 16 and 48 hr post-infection, budding from the viroplasm into the rough endoplasmic reticulum cisternae in ileum enterocytes. Clear evidence of viral replication, observed by electron microscopy was not described before in heterologous murine models. Regeneration of the intestinal villi began at the third day post-infection. Despite some differences observed in clinical symptoms and microscopic analysis of homologous and heterologous rotavirus infections, we concluded that mechanisms of heterologous rotavirus infection in mice follow similar patterns to those observed in the homologous models.

  16. Investigations of peritoneal and intestinal infections of adult hookworms (Uncinaria spp.) in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, California (2003).

    Science.gov (United States)

    Lyons, Eugene T; Delong, R L; Nadler, S A; Laake, J L; Orr, A J; Delong, B L; Pagan, C

    2011-09-01

    The peritoneal cavity (PNC) and intestine of northern fur seal (Callorhinus ursinus) pups and California sea lion (Zalophus californianus) pups that died in late July and early August, 2003, on San Miguel Island, California, were examined for hookworms. Prevalence and morphometric studies were done with the hookworms in addition to molecular characterization. Based on this and previous molecular studies, hookworms from fur seals are designated as Uncinaria lucasi and the species from sea lions as Uncinaria species A. Adult hookworms were found in the PNC of 35 of 57 (61.4%) fur seal pups and of 13 of 104 (12.5%) sea lion pups. The number of hookworms located in the PNC ranged from 1 to 33 (median = 3) for the infected fur seal pups and 1 to 16 (median = 2) for the infected sea lion pups. In addition to the PNC, intestines of 43 fur seal and 32 sea lion pups were examined. All of these pups were positive for adult hookworms. The worms were counted from all but one of the sea lion pups. Numbers of these parasites in the intestine varied from 3 to 2,344 (median = 931) for the fur seal pups and 39 to 2,766 (median = 643) for the sea lion pups. Sea lion pups with peritoneal infections had higher intensity infections in the intestines than did pups without peritoneal infections, lending some support for the hypothesis that peritoneal infections result from high-intensity infections of adult worms. There was no difference in intestinal infection intensities between fur seal pups with and without peritoneal infections. Female adult hookworms in the intestines of both host species were significantly larger than males, and sea lion hookworms were larger than those in fur seals. Worms in the intestine also were larger than worms found in the PNC. Gene sequencing and (RFLP) analysis of (PCR) amplified (ITS) ribosomal DNA were used to diagnose the species of 172 hookworms recovered from the PNC and intestine of 18 C. ursinus and seven Z. californianus hosts

  17. Effective anthelmintic therapy of residents living in endemic area of high prevalence for Hookworm and Schistosoma mansoni infections enhances the levels of allergy risk factor anti-Der p1 IgE

    Directory of Open Access Journals (Sweden)

    Sabrina S. Campolina

    2015-01-01

    Full Text Available In this work were investigated the relationship between Hookworm/Schistosoma mansoni infections and allergy related risk factors in two endemic areas with distinct prevalence of infections and co-infection. The intensity of infections, eosinophilia, allergy risk factors, infections status and anti-Der p1 IgE levels before and 2 years (population 1 and 3 years (population 2 after anthelmintic treatment, were evaluated. It was observed that the population with lower prevalence and intensity of infection (population 2 had lower eosinophils counts (>600/mm3 and higher animal contact than the population with higher parasites intensity (population 1. After anthelmintic treatment the intensity of S. mansoni single infection decreased, but no changes were observed in Hookworm and co-infected individuals. The anthelmintic treatment also enhanced anti-Der p1 IgE optical density in ELISA on the subgroups that became negative for helminth infection regardless of their previous infection condition in population 1. Facing that, we evaluated the anti-Der p1 IgE reactivity index, and the ratio (after/before treatment was significantly higher in patients co-infected before treatment. On the other hand, no association between anti-Der p1 IgE reactivity index and the intensity of infections were observed. In conclusion, effective anthelmintic therapy of subjects from endemic areas with high prevalence of Hookworm and S. mansoni infections enhances anti-Der p1 IgE levels.

  18. Partial protection of SIV-infected rhesus monkeys against superinfection with a heterologous SIV isolate

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory

    2009-01-01

    Although there is increasing evidence that individuals already infected with human immunodeficiency virus type 1 (HIV-1) can be infected with a heterologous strain of the virus, the extent of protection against superinfection conferred by the first infection and the biologic consequences of superinfection are not well understood. We explored these questions in the simian immunodeficiency virus (SIV)/rhesus monkey model of HIV-1/AIDS. We infected cohorts of rhesus monkeys with either SIVmac251 or SIVsmE660 and then exposed animals to the reciprocal virus through intrarectal inoculations. Employing a quantitative real-time PCR assay, we determined the replication kinetics of the two strains of virus for 20 weeks. We found that primary infection with a replication-competent virus did not protect against acquisition of infection by a heterologous virus but did confer relative control of the superinfecting virus. In animals that became superinfected, there was a reduction in peak replication and rapid control of the second virus. The relative susceptibility to superinfection was not correlated with CD4(+) T-cell count, CD4(+) memory T-cell subsets, cytokine production by virus-specific CD8(+) or CD4(+) cells, or neutralizing antibodies at the time of exposure to the second virus. Although there were transient increases in viral loads of the primary virus and a modest decline in CD4(+) T-cell counts after superinfection, there was no evidence of disease acceleration. These findings indicate that an immunodeficiency virus infection confers partial protection against a second immunodeficiency virus infection, but this protection may be mediated by mechanisms other than classical adaptive immune responses.

  19. Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples.

    Science.gov (United States)

    Mugambi, Robert Muriuki; Agola, Eric L; Mwangi, Ibrahim N; Kinyua, Johnson; Shiraho, Esther Andia; Mkoji, Gerald M

    2015-11-06

    Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in faecal samples, is not effective due to its low sensitivity that is brought about mainly by non-random distribution of eggs in stool and day to day variation in egg output. It is tedious, cumbersome to perform and requires experience for correct diagnosis. LAMP-based tests are simple, relatively cheap, offer greater sensitivity, specificity than existing tests, have high throughput capability, and are ideal for use at the point of care. We have developed a LAMP diagnostic test for detection of hookworm infection in faecal samples. LAMP relies on auto cycling strand displacement DNA synthesis performed at isothermal temperature by Bst polymerase and a set of 4 specific primers. The primers used in the LAMP assay were based on the second Internal Transcribed Spacer (ITS-2) region and designed using Primer Explorer version 4 Software. The ITS-2 region of the ribosomal gene (rDNA) was identified as a suitable target due to its low mutation rates and substantial differences between species. DNA was extracted directly from human faecal samples, followed by LAMP amplification at isothermal temperature of 63 °C for 1 h. Amplicons were visualized using gel electrophoresis and SYBR green dye. Both specificity and sensitivity of the assay were determined. The LAMP based technique developed was able to detect N. americanus DNA in faecal samples. The assay showed 100 % specificity and no cross-reaction was observed with other helminth parasites (S. mansoni, A. lumbricoides or T. trichiura). The

  20. Suppression of adaptive immunity to heterologous antigens during Plasmodium infection through hemozoin-induced failure of dendritic cell function

    Directory of Open Access Journals (Sweden)

    Phillips R

    2006-04-01

    Full Text Available Abstract Background Dendritic cells (DCs are central to the initiation and regulation of the adaptive immune response during infection. Modulation of DC function may therefore allow evasion of the immune system by pathogens. Significant depression of the host's systemic immune response to both concurrent infections and heterologous vaccines has been observed during malaria infection, but the mechanisms underlying this immune hyporesponsiveness are controversial. Results Here, we demonstrate that the blood stages of malaria infection induce a failure of DC function in vitro and in vivo, causing suboptimal activation of T cells involved in heterologous immune responses. This effect on T-cell activation can be transferred to uninfected recipients by DCs isolated from infected mice. Significantly, T cells activated by these DCs subsequently lack effector function, as demonstrated by a failure to migrate to lymphoid-organ follicles, resulting in an absence of B-cell responses to heterologous antigens. Fractionation studies show that hemozoin, rather than infected erythrocyte (red blood cell membranes, reproduces the effect of intact infected red blood cells on DCs. Furthermore, hemozoin-containing DCs could be identified in T-cell areas of the spleen in vivo. Conclusion Plasmodium infection inhibits the induction of adaptive immunity to heterologous antigens by modulating DC function, providing a potential explanation for epidemiological studies linking endemic malaria with secondary infections and reduced vaccine efficacy.

  1. Transmission of a heterologous clade C Symbiodinium in a model anemone infection system via asexual reproduction

    Directory of Open Access Journals (Sweden)

    Wan-Nan U. Chen

    2016-08-01

    Full Text Available Anemones of genus Exaiptasia are used as model organisms for the study of cnidarian-dinoflagellate (genus Symbiodinium endosymbiosis. However, while most reef-building corals harbor Symbiodinium of clade C, Exaiptasia spp. anemones mainly harbor clade B Symbiodinium (ITS2 type B1 populations. In this study, we reveal for the first time that bleached Exaiptasia pallida anemones can establish a symbiotic relationship with a clade C Symbiodinium (ITS2 type C1. We further found that anemones can transmit the exogenously supplied clade C Symbiodinium cells to their offspring by asexual reproduction (pedal laceration. In order to corroborate the establishment of stable symbiosis, we used microscopic techniques and genetic analyses to examine several generations of anemones, and the results of these endeavors confirmed the sustainability of the system. These findings provide a framework for understanding the differences in infection dynamics between homologous and heterologous dinoflagellate types using a model anemone infection system.

  2. Brucella suis strain 2 vaccine is safe and protective against heterologous Brucella spp. infections.

    Science.gov (United States)

    Zhu, Liangquan; Feng, Yu; Zhang, Ge; Jiang, Hui; Zhang, Zhen; Wang, Nan; Ding, Jiabo; Suo, Xun

    2016-01-12

    Brucellosis is a wide spread zoonotic disease that causes abortion and infertility in mammals and leads to debilitating, febrile illness in humans. Brucella abortus, Brucella melitensis and Brucella suis are the major pathogenic species to humans. Vaccination with live attenuated B. suis strain 2 (S2) vaccine is an essential and critical component in the control of brucellosis in China. The S2 vaccine is very effective in preventing brucellosis in goats, sheep, cattle and swine. However, there are still debates outside of China whether the S2 vaccine is able to provide protection against heterologous virulent Brucella species. We investigated the residual virulence, immunogenicity and protective efficacy of the S2 vaccine in BALB/c mice by determining bacteria persistence in spleen, serum antibody response, cellular immune response and protection against a heterologous virulent challenge. The S2 vaccine was of low virulence as there were no bacteria recovered in spleen four weeks post vaccination. The vaccinated mice developed Brucella-specific IgG in 2-3 weeks, and a burst production of IFN-γ at one week as well as a two-fold increase in TNF-α production. The S2 vaccine protected mice from a virulent challenge by B. melitensis M28, B. abortus 2308 and B. suis S1330, and the S2 vaccinated mice did not develop any clinical signs or tissue damage. Our study demonstrated that the S2 vaccine is of low virulence, stimulates good humoral and cellular immunity and protects animals against infection by heterologous, virulent Brucella species. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Lactobacillus priming of the respiratory tract: Heterologous immunity and protection against lethal pneumovirus infection.

    Science.gov (United States)

    Garcia-Crespo, Katia E; Chan, Calvin C; Gabryszewski, Stanislaw J; Percopo, Caroline M; Rigaux, Peter; Dyer, Kimberly D; Domachowske, Joseph B; Rosenberg, Helene F

    2013-03-01

    We showed previously that wild-type mice primed via intranasal inoculation with live or heat-inactivated Lactobacillus species were fully (100%) protected against the lethal sequelae of infection with the virulent pathogen, pneumonia virus of mice (PVM), a response that is associated with diminished expression of proinflammatory cytokines and diminished virus recovery. We show here that 40% of the mice primed with live Lactobacillus survived when PVM challenge was delayed for 5months. This robust and sustained resistance to PVM infection resulting from prior interaction with an otherwise unrelated microbe is a profound example of heterologous immunity. We undertook the present study in order to understand the nature and unique features of this response. We found that intranasal inoculation with L. reuteri elicited rapid, transient neutrophil recruitment in association with proinflammatory mediators (CXCL1, CCL3, CCL2, CXCL10, TNF-alpha and IL-17A) but not Th1 cytokines. IFNγ does not contribute to survival promoted by Lactobacillus-priming. Live L. reuteri detected in lung tissue underwent rapid clearance, and was undetectable at 24h after inoculation. In contrast, L. reuteri peptidoglycan (PGN) and L. reuteri genomic DNA (gDNA) were detected at 24 and 48h after inoculation, respectively. In contrast to live bacteria, intranasal inoculation with isolated L. reuteri gDNA elicited no neutrophil recruitment, had minimal impact on virus recovery and virus-associated production of CCL3, and provided no protection against the negative sequelae of virus infection. Isolated PGN elicited neutrophil recruitment and proinflammatory cytokines but did not promote sustained survival in response to subsequent PVM infection. Overall, further evaluation of the responses leading to Lactobacillus-mediated heterologous immunity may provide insight into novel antiviral preventive modalities. Published by Elsevier B.V.

  4. Heterologous RNA-silencing suppressors from both plant- and animal-infecting viruses support plum pox virus infection.

    Science.gov (United States)

    Maliogka, Varvara I; Calvo, María; Carbonell, Alberto; García, Juan Antonio; Valli, Adrian

    2012-07-01

    HCPro, the RNA-silencing suppressor (RSS) of viruses belonging to the genus Potyvirus in the family Potyviridae, is a multifunctional protein presumably involved in all essential steps of the viral infection cycle. Recent studies have shown that plum pox potyvirus (PPV) HCPro can be replaced successfully by cucumber vein yellowing ipomovirus P1b, a sequence-unrelated RSS from a virus of the same family. In order to gain insight into the requirement of a particular RSS to establish a successful potyviral infection, we tested the ability of different heterologous RSSs from both plant- and animal-infecting viruses to substitute for HCPro. Making use of engineered PPV chimeras, we show that PPV HCPro can be replaced functionally by some, but not all, unrelated RSSs, including the NS1 protein of the mammal-infecting influenza A virus. Interestingly, the capacity of a particular RSS to replace HCPro does not correlate strictly with its RNA silencing-suppression strength. Altogether, our results suggest that not all suppression strategies are equally suitable for efficient escape of PPV from the RNA-silencing machinery. The approach followed here, based on using PPV chimeras in which an under-consideration RSS substitutes for HCPro, could further help to study the function of diverse RSSs in a 'highly sensitive' RNA-silencing context, such as that taking place in plant cells during the process of a viral infection.

  5. Hookworm-related anaemia among pregnant women: a systematic review.

    Directory of Open Access Journals (Sweden)

    Simon Brooker

    2008-09-01

    Full Text Available Hookworm infection is among the major causes of anaemia in poor communities, but its importance in causing maternal anaemia is poorly understood, and this has hampered effective lobbying for the inclusion of anthelmintic treatment in maternal health packages. We sought to review existing evidence on the role of hookworm as a risk factor for anaemia among pregnant women. We also estimate the number of hookworm infections in pregnant women in sub-Saharan Africa (SSA.Structured searches using MEDLINE and EMBASE as well as manual searches of reference lists were conducted, and unpublished data were obtained by contacting authors. Papers were independently reviewed by two authors, and relevant data were extracted. We compared haemoglobin concentration (Hb according to intensity of hookworm infection and calculated standardised mean differences and 95% confidence intervals. To estimate the number of pregnant women, we used population surfaces and a spatial model of hookworm prevalence.One hundred and five reports were screened and 19 were eligible for inclusion: 13 cross-sectional studies, 2 randomised controlled trials, 2 non-randomised treatment trials and 2 observational studies. Comparing uninfected women and women lightly (1-1,999 eggs/gram [epg] infected with hookworm, the standardised mean difference (SMD was -0.24 (95% CI: -0.36 to -0.13. The SMD between women heavily (4000+ epg infected and those lightly infected was -0.57 (95% CI: -0.87 to -0.26. All identified intervention studies showed a benefit of deworming for maternal or child health, but since a variety of outcomes measures were employed, quantitative evaluation was not possible. We estimate that 37.7 million women of reproductive age in SSA are infected with hookworm in 2005 and that approximately 6.9 million pregnant women are infected.Evidence indicates that increasing hookworm infection intensity is associated with lower haemoglobin levels in pregnant women in poor countries

  6. Advancing a vaccine to prevent hookworm disease and anemia.

    Science.gov (United States)

    Hotez, Peter J; Beaumier, Coreen M; Gillespie, Portia M; Strych, Ulrich; Hayward, Tara; Bottazzi, Maria Elena

    2016-06-03

    A human hookworm vaccine is under development and in clinical trials in Africa and the Americas. The vaccine contains the Na-APR-1 and Na-GST-1 antigens. It elicits neutralizing antibodies that interfere with establishment of the adult hookworm in the gut and the ability of the parasite to feed on blood. The vaccine target product profile is focused on the immunization of children to prevent hookworm infection and anemia caused by Necator americanus. It is intended for use in low- and middle-income countries where hookworm is highly endemic and responsible for at least three million disability-adjusted life years. So far, the human hookworm vaccine is being developed in the non-profit sector through the Sabin Vaccine Institute Product Development Partnership (PDP), in collaboration with the HOOKVAC consortium of European and African partners. We envision the vaccine to be incorporated into health systems as part of an elimination strategy for hookworm infection and other neglected tropical diseases, and as a means to reduce global poverty and address the Sustainable Development Goals. Copyright © 2016 World Health Organization. Published by Elsevier Ltd.. All rights reserved.

  7. Hookworm infection and anemia in adult women in rural Chiapas, Mexico Anemia e infección por Necator americanus en mujeres en Chiapas, México

    Directory of Open Access Journals (Sweden)

    Paula E. Brentlinger

    2003-04-01

    Full Text Available OBJECTIVE: To describe associations between anemia and hookworm (Necator americanus infection in hospitalized women in rural Chiapas, Mexico. MATERIAL AND METHODS: We retrospectively reviewed the hospital records of 68 anemic women (defined as having a hemoglobin level OBJETIVO: Describir la asociación entre anemia severa e infección con Necator americanus en una población de mujeres hospitalizadas en el estado de Chiapas, México. MATERIAL Y MÉTODOS: En el registro de ingresos del año 1999 de un hospital rural en Altamirano, Chiapas, se identificaron a las pacientes con diagnósticos de egreso de anemia (definida como hemoglobina<10mg/dl y/o parasitosis intestinal. También se revisó el registro de transfusiones para identificar a las mujeres mayores de 14 años de edad que recibieron sangre. La revisión de expedientes y el análisis de datos se llevó a cabo en el año 2000. Las comparaciones de las características de las pacientes se hicieron con la prueba t de Student (para variables continuas y la prueba ji2 (para variables categóricas. La significancia estadística se estableció con un valor de p< 0.01. RESULTADOS: En las mujeres en quienes se realizó examen coproscópico, 50% tuvieron N. americanus. La presencia de N. americanus no excluyó la presencia de otro factor de riesgo para anemia, por ejemplo embarazo o hemorragia. Los niveles de hemoglobina de las mujeres infectadas con N. americanus fueron significativamente más bajos (promedio 4.1 g/dl que los de las demás mujeres anémicas (promedio 7.0 gm/dl, y la prevalencia de N. americanus en mujeres anémicas fue más alta (50.0% que en la población atendida por el hospital (1.9%. CONCLUSIONES: Aunque la prevalencia de infección con N. americanus no se considera alta en la población general mexicana, fue importante en las mujeres anémicas que se sometieron a coproscopía en nuestro estudio. Las mujeres anémicas ameritan coproscopía donde existe N. americanus, y pueden

  8. Biochemical Characterization and Vaccine Potential of a Heme-Binding Glutathione Transferase from the Adult Hookworm Ancylostoma caninum

    Science.gov (United States)

    Zhan, Bin; Liu, Sen; Perally, Samirah; Xue, Jian; Fujiwara, Ricardo; Brophy, Peter; Xiao, Shuhua; Liu, Yueyuan; Feng, Jianjun; Williamson, Angela; Wang, Yan; Bueno, Lilian L.; Mendez, Susana; Goud, Gaddam; Bethony, Jeffrey M.; Hawdon, John M.; Loukas, Alex; Jones, Karen; Hotez, Peter J.

    2005-01-01

    We report the cloning and expression of Ac-GST-1, a novel glutathione S-transferase from the adult hookworm Ancylostoma caninum, and its possible role in parasite blood feeding and as a vaccine target. The predicted Ac-GST-1 open reading frame contains 207 amino acids (mass, 24 kDa) and exhibited up to 65% amino acid identity with other nematode GSTs. mRNA encoding Ac-GST-1 was detected in adults, eggs, and larval stages, but the protein was detected only in adult hookworm somatic extracts and excretory/secretory products. Using antiserum to the recombinant protein, Ac-GST-1 was immunolocalized to the parasite hypodermis and muscle tissue and weakly to the intestine. Recombinant Ac-GST-1 was enzymatically active, as determined by conjugation of glutathione to a model substrate, and exhibited a novel high-affinity binding site for hematin. The possible role of Ac-GST-1 in parasite heme detoxification during hemoglobin digestion or heme uptake prompted interest in evaluating it as a potential vaccine antigen. Vaccination of dogs with Ac-GST-1 resulted in a 39.4% reduction in the mean worm burden and 32.3% reduction in egg counts compared to control dogs following larval challenge, although the reductions were not statistically significant. However, hamsters vaccinated with Ac-GST-1 exhibited statistically significant worm reduction (53.7%) following challenge with heterologous Necator americanus larvae. These studies suggest that Ac-GST-1 is a possible drug and vaccine target for hookworm infection. PMID:16177370

  9. Prevalence and zoonotic potential of canine hookworms in Malaysia

    Directory of Open Access Journals (Sweden)

    Mahdy Mohammed AK

    2012-05-01

    Full Text Available Abstract Background Canine hookworm infection is endemic in Southeast Asian countries with a prevalence ranging from 70% to 100%, with zoonotic transmission representing a potentially significant public health concern. However, there are limited data available on the prevalence of canine hookworms in Malaysia. This study was conducted to determine the prevalence of hookworm and Ancylostoma species among dogs in Malaysia. Methods Faecal samples were collected from 221 dogs living in urban areas, rural areas and animal shelters in Selangor. Faecal samples were processed using the formal-ether concentration technique followed by wet mount preparation and iodine staining for the detection of hookworm eggs. Samples positive for hookworm eggs were examined using PCR, targeting ITS2 and 28 s rRNA region, and subsequently sequenced in both directions. The sequences were phylogenetically analysed using MrBayes for Bayesian Inference. Results The overall prevalence of hookworm among dogs was 48% (95%CI; 41.41–54.95. Rural stray dogs had the highest prevalence 71.4% (95%CI; 61.13–81.49 followed by urban stray dogs, recording 48% (95%CI; 34.15–61.85 and lastly dogs in shelters with 28.7% (95%CI; 19.56–37.84. Logistic regression identified rural stray dogs as a high risk group (OR = 4.55, 95%; 2.50–8.31 and keeping dogs in shelters as a protective factor (OR = 0.24, 95%; 0.14–0.43. Molecular methods identified both Ancylostoma ceylanicum and Ancylostoma caninum with A. ceylanicum being predominant among urban stray dogs. Rural dogs had a higher prevalence of A. caninum than A. ceylanicum, while both species showed equal distribution among dogs in shelters. Phylogenetic analysis placed A. ceylanicum isolated from dogs in one group with A. ceylanicum human isolates. Conclusion This study indicates that dogs have the potential to act as reservoir hosts of human hookworm infection in Malaysia. This finding necessitates the inclusion of dogs

  10. Analysis of Host Range Restriction Determinants in the Rabbit Model: Comparison of Homologous and Heterologous Rotavirus Infections

    Science.gov (United States)

    Ciarlet, Max; Estes, Mary K.; Barone, Christopher; Ramig, Robert F.; Conner, Margaret E.

    1998-01-01

    The main limitation of both the rabbit and mouse models of rotavirus infection is that human rotavirus (HRV) strains do not replicate efficiently in either animal. The identification of individual genes necessary for conferring replication competence in a heterologous host is important to an understanding of the host range restriction of rotavirus infections. We recently reported the identification of the P type of the spike protein VP4 of four lapine rotavirus strains as being P[14]. To determine whether VP4 is involved in host range restriction in rabbits, we evaluated infection in rotavirus antibody-free rabbits inoculated orally with two P[14] HRVs, PA169 (G6) and HAL1166 (G8), and with several other HRV strains and animal rotavirus strains of different P and G types. We also evaluated whether the parental rhesus rotavirus (RRV) (P5B[3], G3) and the derived RRV-HRV reassortant candidate vaccine strains RRV × D (G1), RRV × DS-1 (G2), and RRV × ST3 (G4) would productively infect rabbits. Based on virus shedding, limited replication was observed with the P[14] HRV strains and with the SA11 Cl3 (P[2], G3) and SA11 4F (P6[1], G3) animal rotavirus strains, compared to the homologous ALA strain (P[14], G3). However, even limited infection provided complete protection from rotavirus infection when rabbits were challenged orally 28 days postinoculation (DPI) with 103 50% infective doses of ALA rabbit rotavirus. Other HRVs did not productively infect rabbits and provided no significant protection from challenge, in spite of occasional seroconversion. Simian RRV replicated as efficiently as lapine ALA rotavirus in rabbits and provided complete protection from ALA challenge. Live attenuated RRV reassortant vaccine strains resulted in no, limited, or productive infection of rabbits, but all rabbits were completely protected from heterotypic ALA challenge. The altered replication efficiency of the reassortants in rabbits suggests a role for VP7 in host range restriction

  11. Migrant clinics and hookworm science: peripheral origins of International Health, 1840-1920.

    Science.gov (United States)

    Palmer, Steven

    2009-01-01

    This article proposes a global history of hookworm disease based on the main scientific publications on hookworm disease (ankylostomiasis) in the late nineteenth and early twentieth centuries and archival sources from the Rockefeller Foundation's International Health Board. The location of hookworm research is explained by the presence of large concentrations of migrant laborers who suffered from serious hookworm disease in frontier regions during the second industrial revolution. This hookworm disease pandemic was not the result of a linear spread of infection. The extraordinary labor conditions in these regions created ideal ecologies for the reproduction of the parasite, leading to levels of infection that produced ankylostomiasis. The major findings in hookworm science came from research-oriented physicians building new institutions of medical science in peripheral nation-states. In a number of Latin American states their work led to treatment programs conceived in national terms that preceded the interest of Rockefeller philanthropy in the disease. The Rockefeller Foundation incorporated these programs in order to launch its International Health hookworm eradication program in 1914.

  12. Molecular Identification of Hookworm Isolates in Humans, Dogs and Soil in a Tribal Area in Tamil Nadu, India.

    Directory of Open Access Journals (Sweden)

    Santosh George

    2016-08-01

    Full Text Available Hookworms (Necator americanus and Ancylostoma duodenale remain a major public health problem worldwide. Infections with hookworms (e.g., A. caninum, A. ceylanicum and A. braziliense are also prevalent in dogs, but the role of dogs as a reservoir for zoonotic hookworm infections in humans needs to be further explored.As part of an open-label community based cluster-randomized trial in a tribal area in Tamil Nadu (India; 2013-2015, a total of 143 isolates of hookworm eggs from human stool were speciated based on a previously described PCR-RFLP methodology. The presence of hookworm DNA was confirmed in 119 of 143 human samples. N. americanus (100% was the most prevalent species, followed by A. caninum (16.8% and A. duodenale (8.4%. Because of the high prevalence of A. caninum in humans, dog samples were also collected to assess the prevalence of A. caninum in dogs. In 68 out of 77 canine stool samples the presence of hookworms was confirmed using PCR-RFLP. In dogs, both A. caninum (76.4% and A. ceylanicum (27.9% were identified. Additionally, to determine the contamination of soil with zoonotic hookworm larvae, topsoil was collected from defecating areas. Hookworm DNA was detected in 72 out of 78 soil samples that revealed presence of hookworm-like nematode larvae. In soil, different hookworm species were identified, with animal hookworms being more prevalent (A. ceylanicum: 60.2%, A. caninum: 29.4%, A. duodenale: 16.6%, N. americanus: 1.4%, A. braziliense: 1.4%.In our study we regularly detected the presence of A. caninum DNA in the stool of humans. Whether this is the result of infection is currently unknown but it does warrant a closer look at dogs as a potential reservoir.

  13. Molecular Identification of Hookworm Isolates in Humans, Dogs and Soil in a Tribal Area in Tamil Nadu, India.

    Science.gov (United States)

    George, Santosh; Levecke, Bruno; Kattula, Deepthi; Velusamy, Vasanthakumar; Roy, Sheela; Geldhof, Peter; Sarkar, Rajiv; Kang, Gagandeep

    2016-08-01

    Hookworms (Necator americanus and Ancylostoma duodenale) remain a major public health problem worldwide. Infections with hookworms (e.g., A. caninum, A. ceylanicum and A. braziliense) are also prevalent in dogs, but the role of dogs as a reservoir for zoonotic hookworm infections in humans needs to be further explored. As part of an open-label community based cluster-randomized trial in a tribal area in Tamil Nadu (India; 2013-2015), a total of 143 isolates of hookworm eggs from human stool were speciated based on a previously described PCR-RFLP methodology. The presence of hookworm DNA was confirmed in 119 of 143 human samples. N. americanus (100%) was the most prevalent species, followed by A. caninum (16.8%) and A. duodenale (8.4%). Because of the high prevalence of A. caninum in humans, dog samples were also collected to assess the prevalence of A. caninum in dogs. In 68 out of 77 canine stool samples the presence of hookworms was confirmed using PCR-RFLP. In dogs, both A. caninum (76.4%) and A. ceylanicum (27.9%) were identified. Additionally, to determine the contamination of soil with zoonotic hookworm larvae, topsoil was collected from defecating areas. Hookworm DNA was detected in 72 out of 78 soil samples that revealed presence of hookworm-like nematode larvae. In soil, different hookworm species were identified, with animal hookworms being more prevalent (A. ceylanicum: 60.2%, A. caninum: 29.4%, A. duodenale: 16.6%, N. americanus: 1.4%, A. braziliense: 1.4%). In our study we regularly detected the presence of A. caninum DNA in the stool of humans. Whether this is the result of infection is currently unknown but it does warrant a closer look at dogs as a potential reservoir.

  14. Diverse heterologous primary infections radically alter immunodominance hierarchies and clinical outcomes following H7N9 influenza challenge in mice.

    Directory of Open Access Journals (Sweden)

    Susu Duan

    2015-02-01

    Full Text Available The recent emergence of a novel H7N9 influenza A virus (IAV causing severe human infections in China raises concerns about a possible pandemic. The lack of pre-existing neutralizing antibodies in the broader population highlights the potential protective role of IAV-specific CD8(+ cytotoxic T lymphocyte (CTL memory specific for epitopes conserved between H7N9 and previously encountered IAVs. In the present study, the heterosubtypic immunity generated by prior H9N2 or H1N1 infections significantly, but variably, reduced morbidity and mortality, pulmonary virus load and time to clearance in mice challenged with the H7N9 virus. In all cases, the recall of established CTL memory was characterized by earlier, greater airway infiltration of effectors targeting the conserved or cross-reactive H7N9 IAV peptides; though, depending on the priming IAV, each case was accompanied by distinct CTL epitope immunodominance hierarchies for the prominent K(bPB(1703, D(bPA(224, and D(bNP(366 epitopes. While the presence of conserved, variable, or cross-reactive epitopes between the priming H9N2 and H1N1 and the challenge H7N9 IAVs clearly influenced any change in the immunodominance hierarchy, the changing patterns were not tied solely to epitope conservation. Furthermore, the total size of the IAV-specific memory CTL pool after priming was a better predictor of favorable outcomes than the extent of epitope conservation or secondary CTL expansion. Modifying the size of the memory CTL pool significantly altered its subsequent protective efficacy on disease severity or virus clearance, confirming the important role of heterologous priming. These findings establish that both the protective efficacy of heterosubtypic immunity and CTL immunodominance hierarchies are reflective of the immunological history of the host, a finding that has implications for understanding human CTL responses and the rational design of CTL-mediated vaccines.

  15. Protection against heterologous infection by using cross antigenicity between schistosoma mansoni and fasciola hepatica

    International Nuclear Information System (INIS)

    Moawad, M.A.; Amin, M.M.

    2004-01-01

    Fasciola hepatica is the causative agent of fasciolosis in many areas in America, Europe, Africa, Asia and Australia. There is an urgent need for improved methods to control the parasite's transmission. The present study is parasitological, immunological (interleukine-1β and interleukine-6) and histopathological investigations on the immunizing effect of cross antigenicity between S. mansoni and F. hepatica against schistosomiasis and fasciolosis in mice. Parasitological study showed that vaccination with irradiated cercariae of S. mansoni or vaccination by F. hepatica whole worm extract (FhWWE) before challenged with encysted metacercariae of F. hepatica or cercariae of S. mansoni played a significant control on the parasitic infection manifested by a remarkable reduction in the means of worm count. Assessment of IL-1β and IL-6 in sera of the experimental groups showed that there are cross reactivity between fasciola / schistosoma and its relation to cross protection. Histopathological examination of vaccinated mice livers showed protection against parasite maturation and liver damage after challenged, as compared to mice infected only without vaccination

  16. Mechanistic and single-dose in vivo therapeutic studies of Cry5B anthelmintic action against hookworms.

    Directory of Open Access Journals (Sweden)

    Yan Hu

    Full Text Available Hookworm infections are one of the most important parasitic infections of humans worldwide, considered by some second only to malaria in associated disease burden. Single-dose mass drug administration for soil-transmitted helminths, including hookworms, relies primarily on albendazole, which has variable efficacy. New and better hookworm therapies are urgently needed. Bacillus thuringiensis crystal protein Cry5B has potential as a novel anthelmintic and has been extensively studied in the roundworm Caenorhabditis elegans. Here, we ask whether single-dose Cry5B can provide therapy against a hookworm infection and whether C. elegans mechanism-of-action studies are relevant to hookworms.To test whether the C. elegans invertebrate-specific glycolipid receptor for Cry5B is relevant in hookworms, we fed Ancylostoma ceylanicum hookworm adults Cry5B with and without galactose, an inhibitor of Cry5B-C. elegans glycolipid interactions. As with C. elegans, galactose inhibits Cry5B toxicity in A. ceylanicum. Furthermore, p38 mitogen-activated protein kinase (MAPK, which controls one of the most important Cry5B signal transduction responses in C. elegans, is functionally operational in hookworms. A. ceylanicum hookworms treated with Cry5B up-regulate p38 MAPK and knock down of p38 MAPK activity in hookworms results in hypersensitivity of A. ceylanicum adults to Cry5B attack. Single-dose Cry5B is able to reduce by >90% A. ceylanicum hookworm burdens from infected hamsters, in the process eliminating hookworm egg shedding in feces and protecting infected hamsters from blood loss. Anthelmintic activity is increased about 3-fold, eliminating >97% of the parasites with a single 3 mg dose (∼30 mg/kg, by incorporating a simple formulation to help prevent digestion in the acidic stomach of the host mammal.These studies advance the development of Cry5B protein as a potent, safe single-dose anthelmintic for hookworm therapy and make available the information of how

  17. Heterologous prime-boost strategy in non-human primates combining the infective dengue virus and a recombinant protein in a formulation suitable for human use.

    Science.gov (United States)

    Valdés, Iris; Hermida, Lisset; Gil, Lázaro; Lazo, Laura; Castro, Jorge; Martín, Jorge; Bernardo, Lídice; López, Carlos; Niebla, Olivia; Menéndez, Tamara; Romero, Yaremis; Sánchez, Jorge; Guzmán, María G; Guillén, Gerardo

    2010-05-01

    The aim of the present work was to test the concept of the heterologous prime-boost strategy combining an infective dengue virus with a recombinant chimeric protein carrying domain III of the envelope protein. Two studies in monkeys, combining recombinant protein PD5 (domain III of the envelope protein from dengue-2 virus, fused to the protein carrier P64k) and the infective dengue virus in the same immunization schedules were carried out. Humoral and cell-mediated immunity were evaluated. In the first study, monkeys received four doses of the protein PD5 and were subsequently infected with one dose of dengue virus. Antibody response measured after virus inoculation was significantly higher compared to that in non-primed monkeys and comparable to that elicited after two doses of infective virus. In a second study, monkeys were infected with one dose of the virus and subsequently boosted with one dose of the recombinant protein, reaching high levels of neutralizing antibodies, which were still detectable 14 months after the last immunization. In addition, the cellular immune response was also recalled. The results obtained in the present work support the approach of heterologous prime-boosting, in either order prime or boost, combining the chimeric protein PD5 (formulated in alum-CPS-A) and an infective dengue virus. The latter could potentially be replaced by an attenuated vaccine candidate. Copyright 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Experimental Andes virus infection in deer mice: characteristics of infection and clearance in a heterologous rodent host.

    Directory of Open Access Journals (Sweden)

    Jessica R Spengler

    Full Text Available New World hantaviruses can cause hantavirus cardiopulmonary syndrome with high mortality in humans. Distinct virus species are hosted by specific rodent reservoirs, which also serve as the vectors. Although regional spillover has been documented, it is unknown whether rodent reservoirs are competent for infection by hantaviruses that are geographically separated, and known to have related, but distinct rodent reservoir hosts. We show that Andes virus (ANDV of South America, carried by the long tailed pygmy rice rat (Oligoryzomys longicaudatus, infects and replicates in vitro and in vivo in the deer mouse (Peromyscus maniculatus, the reservoir host of Sin Nombre virus (SNV, found in North America. In experimentally infected deer mice, viral RNA was detected in the blood, lung, heart and spleen, but virus was cleared by 56 days post inoculation (dpi. All of the inoculated deer mice mounted a humoral immune response by 14 dpi, and produced measurable amounts of neutralizing antibodies by 21 dpi. An up-regulation of Ccl3, Ccl4, Ccl5, and Tgfb, a strong CD4⁺ T-cell response, and down-regulation of Il17, Il21 and Il23 occurred during infection. Infection was transient with an absence of clinical signs or histopathological changes. This is the first evidence that ANDV asymptomatically infects, and is immunogenic in deer mice, a non-natural host species of ANDV. Comparing the immune response in this model to that of the immune response in the natural hosts upon infection with their co-adapted hantaviruses may help clarify the mechanisms governing persistent infection in the natural hosts of hantaviruses.

  19. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

    Science.gov (United States)

    Nfon, Charles; Berhane, Yohannes; Pasick, John; Embury-Hyatt, Carissa; Kobinger, Gary; Kobasa, Darwyn; Babiuk, Shawn

    2012-01-01

    There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI) A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI) A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI). In addition, heterologous cell mediated immunity (CMI) was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  20. Prior infection of chickens with H1N1 or H1N2 avian influenza elicits partial heterologous protection against highly pathogenic H5N1.

    Directory of Open Access Journals (Sweden)

    Charles Nfon

    Full Text Available There is a critical need to have vaccines that can protect against emerging pandemic influenza viruses. Commonly used influenza vaccines are killed whole virus that protect against homologous and not heterologous virus. Using chickens we have explored the possibility of using live low pathogenic avian influenza (LPAI A/goose/AB/223/2005 H1N1 or A/WBS/MB/325/2006 H1N2 to induce immunity against heterologous highly pathogenic avian influenza (HPAI A/chicken/Vietnam/14/2005 H5N1. H1N1 and H1N2 replicated in chickens but did not cause clinical disease. Following infection, chickens developed nucleoprotein and H1 specific antibodies, and reduced H5N1 plaque size in vitro in the absence of H5 neutralizing antibodies at 21 days post infection (DPI. In addition, heterologous cell mediated immunity (CMI was demonstrated by antigen-specific proliferation and IFN-γ secretion in PBMCs re-stimulated with H5N1 antigen. Following H5N1 challenge of both pre-infected and naïve controls chickens housed together, all naïve chickens developed acute disease and died while H1N1 or H1N2 pre-infected chickens had reduced clinical disease and 70-80% survived. H1N1 or H1N2 pre-infected chickens were also challenged with H5N1 and naïve chickens placed in the same room one day later. All pre-infected birds were protected from H5N1 challenge but shed infectious virus to naïve contact chickens. However, disease onset, severity and mortality was reduced and delayed in the naïve contacts compared to directly inoculated naïve controls. These results indicate that prior infection with LPAI virus can generate heterologous protection against HPAI H5N1 in the absence of specific H5 antibody.

  1. Modeling the economic and epidemiologic impact of hookworm vaccine and mass drug administration (MDA) in Brazil, a high transmission setting.

    Science.gov (United States)

    Bartsch, Sarah M; Hotez, Peter J; Hertenstein, Daniel L; Diemert, David J; Zapf, Kristina M; Bottazzi, Maria Elena; Bethony, Jeffrey M; Brown, Shawn T; Lee, Bruce Y

    2016-04-27

    Although mass drug administration (MDA) has helped reduce morbidity attributed to soil-transmitted helminth infections in children, its limitations for hookworm infection have motivated the development of a human hookworm vaccine to both improve morbidity control and ultimately help block hookworm transmission leading to elimination. However, the potential economic and epidemiologic impact of a preventive vaccine has not been fully evaluated. We developed a dynamic compartment model coupled to a clinical and economics outcomes model representing both the human and hookworm populations in a high transmission region of Brazil. Experiments simulated different implementation scenarios of MDA and vaccination under varying circumstances. Considering only intervention costs, both annual MDA and vaccination were highly cost-effective (ICERs ≤ $790/DALY averted) compared to no intervention, with vaccination resulting in lower incremental cost-effectiveness ratios (ICERs ≤ $444/DALY averted). From the societal perspective, vaccination was economically dominant (i.e., less costly and more effective) versus annual MDA in all tested scenarios, except when vaccination was less efficacious (20% efficacy, 5 year duration) and MDA coverage was 75%. Increasing the vaccine's duration of protection and efficacy, and including a booster injection in adulthood all increased the benefits of vaccination (i.e., resulted in lower hookworm prevalence, averted more disability-adjusted life years, and saved more costs). Assuming its target product profile, a pediatric hookworm vaccine drastically decreased hookworm prevalence in children to 14.6% after 20 years, compared to 57.2% with no intervention and 54.1% with MDA. The addition of a booster in adulthood further reduced the overall prevalence from 68.0% to 36.0% and nearly eliminated hookworm infection in children. Using a human hookworm vaccine would be cost-effective and in many cases economically dominant, providing both health

  2. Hookworm infestation in children presenting with melena-case series

    International Nuclear Information System (INIS)

    Saeed, A.; Cheema, H.A.; Alvi, A; Suleman, H.

    2008-01-01

    Hookworm infection is common in children and can present with symptoms of upper gastrointestinal bleeding and severe anemia. Ten children below 5 years presenting with me lena and severe pallor were seen from December 2006 to May 2007 in the gastroenterology and hepatology department of children's hospital, Lahore. All patients had history of transfusion. Complete blood picture, eosinophil count with peripheral smear, stool complete examination for ova and cysts were performed in all cases while upper and lower gastrointestinal Endoscopies were performed in three patients to locate the source of bleeding. Stool routine examination in all these cases confirmed hook worm ova. These patients were managed with Antihelmenthic and stool complete examination was done three days after the medicine. There was no mortality. Though upper gastrointestinal bleeding with hookworm infestation is very rare but in the developing Countries it should be considered when other causes of upper gastrointestinal bleeding are ruled out. (author)

  3. Larval migration in PERL chambers as an in vitro model for percutaneous infection stimulates feeding in the canine hookworm Ancylostoma caninum

    Directory of Open Access Journals (Sweden)

    Welz Claudia

    2011-01-01

    Full Text Available Abstract Background Ancylostoma caninum third-stage larvae are the non-feeding infective stage of this parasite and are able to infect potential hosts via different infection routes. Since percutaneous infection is one of the most important routes and skin penetration is the first step into parasitic life, an existing in vitro model for percutaneous migration was modified and evaluated. The main parameter used to evaluate migration was the migration ratio (migrated larvae as a percentage of total number of larvae recovered. Additionally, the skin lag was calculated, expressing the percentage of larvae remaining in the skin and therefore not being recovered. Since initiation of feeding is proposed to be an important step in the transition from free-living to parasitic A. caninum larvae, feeding assays were performed with in vitro percutaneously migrated larvae. Additionally, infective larvae of A. caninum were activated via serum-stimulation and feeding behaviour was analysed and compared between percutaneously migrated and serum-stimulated larvae. Results Maximum skin migration levels of infective larvae were observed at temperatures above 32°C when larvae were placed on the epidermal side of skin for more than 12 hours. The medium beneath the skin had no effect on migration ratio, and no significant difference between the migration ratios through fresh and frozen/thawed skin was observed. Maximum feeding levels of 93.2% were observed for percutaneously migrated larvae after 48 h incubation, whereas serum-stimulated larvae reached the maximum of 91.0% feeding larvae after 24 h. Conclusions The PERL chamber system was optimised and standardised as an in vitro model for percutaneous migration. The larvae recovered after percutaneous migration showed characteristic signs of activation similar to that of serum-stimulated larvae. The observed difference in time course of resumption of feeding indicates that percutaneously migrated larvae are not

  4. Suppression of basophil histamine release and other IgE-dependent responses in childhood Schistosoma mansoni/hookworm coinfection

    DEFF Research Database (Denmark)

    Pinot de Moira, Angela; Fitzsimmons, Colin M; Jones, Frances M

    2014-01-01

    (HR), plus helminth- and HDM-specific IgE and IgG4 responses were measured pre- and post-treatment. RESULTS: Nonspecific- and helminth-specific-HR, and associations between helminth-specific IgE and helminth-specific HR increased post-treatment. Hookworm infection appeared to modify the relationship...... between circulating levels of HDM-IgE and HR: a significant positive association was observed among children without detectable hookworm infection, but no association was observed among infected children. In addition, hookworm infection was associated with a significantly reduced risk of wheeze, and IgG4...... in Ugandan schoolchildren coinfected with Schistosoma mansoni and hookworm. METHODS: Skin prick test (SPT) sensitivity to house dust mite allergen (HDM) and current wheeze were assessed pre-anthelmintic treatment. Nonspecific (anti-IgE), helminth-specific, and HDM-allergen-specific basophil histamine release...

  5. Identification of hookworm DAF-16/FOXO response elements and direct gene targets.

    Directory of Open Access Journals (Sweden)

    Xin Gao

    2010-08-01

    Full Text Available The infective stage of the parasitic nematode hookworm is developmentally arrested in the environment and needs to infect a specific host to complete its life cycle. The canine hookworm (Ancylostoma caninum is an excellent model for investigating human hookworm infections. The transcription factor of A. caninum, Ac-DAF-16, which has a characteristic fork head or "winged helix" DNA binding domain (DBD, has been implicated in the resumption of hookworm development in the host. However, the precise roles of Ac-DAF-16 in hookworm parasitism and its downstream targets are unknown. In the present study, we combined molecular techniques and bioinformatics to identify a group of Ac-DAF-16 binding sites and target genes.The DNA binding domain of Ac-DAF-16 was used to select genomic fragments by in vitro genomic selection. Twenty four bound genomic fragments were analyzed for the presence of the DAF-16 family binding element (DBE and possible alternative Ac-DAF-16 bind motifs. The 22 genes linked to these genomic fragments were identified using bioinformatics tools and defined as candidate direct gene targets of Ac-DAF-16. Their developmental stage-specific expression patterns were examined. Also, a new putative DAF-16 binding element was identified.Our results show that Ac-DAF-16 is involved in diverse biological processes throughout hookworm development. Further investigation of these target genes will provide insights into the molecular basis by which Ac-DAF-16 regulates its downstream gene network in hookworm infection.

  6. Molecular differentiation of three canine and feline hookworms in South China through HRM analysis.

    Science.gov (United States)

    Wang, M W; Yan, X X; Hang, J X; Shi, X L; Fu, Y Q; Zhang, P; Yang, F; Pan, W D; Li, G Q

    2018-02-05

    To investigate the prevalence of canine and feline hookworms in South China, and to assess the risk of zoonotic hookworms to humans, one pair of primers (HRM-F/HRM-R) was designed to establish a high-resolution melting (HRM) method based on internal transcribed spacer 1 (ITS-1) rDNA for the detection of Ancylostoma ceylanicum, A. caninum and A. tubaeforme infection. The results showed that the HRM for the three hookworms produced different melting-curve profiles, where melting temperature (T m) values were 84.50°C for A. ceylanicum, 82.25°C for A. caninum and 81.73°C for A. tubaeforme, respectively. The reproducibility of intra- and inter-assay melting curves was almost perfect. The lowest concentration detected was about 5.69 ×10-4 g/μl. The HRM detection results from 18 canine and feline hookworm samples were in complete accordance with their sequencing results. The HRM method was more sensitive than the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique in the detection of 98 clinical samples. It is concluded that the HRM method can differentiate between A. ceylanicum, A. caninum, A. tubaeforme and their mixed infections, which may provide important technical support for the zoonotic risk assessment and molecular epidemiological survey of canine and feline hookworms.

  7. Unexpected absence of genetic separation of a highly diverse population of hookworms from geographically isolated hosts.

    Science.gov (United States)

    Haynes, Benjamin T; Marcus, Alan D; Higgins, Damien P; Gongora, Jaime; Gray, Rachael; Šlapeta, Jan

    2014-12-01

    The high natal site fidelity of endangered Australian sea lions (Neophoca cinerea) along the southern Australian coast suggests that their maternally transmitted parasitic species, such as hookworms, will have restricted potential for dispersal. If this is the case, we would expect to find a hookworm haplotype structure corresponding to that of the host mtDNA haplotype structure; that is, restricted among geographically separated colonies. In this study, we used a fragment of the cytochrome c oxidase I mitochondrial DNA (mtDNA) gene to investigate the diversity of hookworms (Uncinaria sanguinis) in N. cinerea to assess the importance of host distribution and ecology on the evolutionary history of the parasite. High haplotype (h=0.986) and nucleotide diversity (π=0.013) were seen, with 45 unique hookworm mtDNA haplotypes across N. cinerea colonies; with most of the variation (78%) arising from variability within hookworms from individual colonies. This is supported by the low genetic differentiation co-efficient (GST=0.007) and a high gene flow (Nm=35.25) indicating a high migration rate between the populations of hookworms. The haplotype network demonstrated no clear distribution and delineation of haplotypes according to geographical location. Our data rejects the vicariance hypothesis; that female host natal site fidelity and the transmammary route of infection restrict hookworm gene flow between N. cinerea populations and highlights the value of studies of parasite diversity and dispersal to challenge our understanding of parasite and host ecology. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Investigating hookworm genomes by comparative analysis of two Ancylostoma species

    Directory of Open Access Journals (Sweden)

    Kapulkin Wadim

    2005-04-01

    Full Text Available Abstract Background Hookworms, infecting over one billion people, are the mostly closely related major human parasites to the model nematode Caenorhabditis elegans. Applying genomics techniques to these species, we analyzed 3,840 and 3,149 genes from Ancylostoma caninum and A. ceylanicum. Results Transcripts originated from libraries representing infective L3 larva, stimulated L3, arrested L3, and adults. Most genes are represented in single stages including abundant transcripts like hsp-20 in infective L3 and vit-3 in adults. Over 80% of the genes have homologs in C. elegans, and nearly 30% of these were with observable RNA interference phenotypes. Homologies were identified to nematode-specific and clade V specific gene families. To study the evolution of hookworm genes, 574 A. caninum / A. ceylanicum orthologs were identified, all of which were found to be under purifying selection with distribution ratios of nonsynonymous to synonymous amino acid substitutions similar to that reported for C. elegans / C. briggsae orthologs. The phylogenetic distance between A. caninum and A. ceylanicum is almost identical to that for C. elegans / C. briggsae. Conclusion The genes discovered should substantially accelerate research toward better understanding of the parasites' basic biology as well as new therapies including vaccines and novel anthelmintics.

  9. A polyvalent influenza A DNA vaccine induces heterologous immunity and protects pigs against pandemic A(H1N1)pdm09 virus infection

    DEFF Research Database (Denmark)

    Bragstad, Karoline; Vinner, Lasse; Hansen, Mette Sif

    2013-01-01

    seasonal and emerging influenza viruses. We have developed an alternative influenza vaccine based on DNA expressing selected influenza proteins of pandemic and seasonal origin. In the current study, we investigated the protection of a polyvalent influenza DNA vaccine approach in pigs. We immunised pigs...... intradermally with a combination of influenza DNA vaccine components based on the pandemic 1918 H1N1 (M and NP genes), pandemic 2009 H1N1pdm09 (HA and NA genes) and seasonal 2005 H3N2 genes (HA and NA genes) and investigated the protection against infection with virus both homologous and heterologous to the DNA...... of this DNA vaccine to limit virus shedding may have an impact on virus spread among pigs which could possibly extend to humans as well, thereby diminishing the risk for epidemics and pandemics to evolve....

  10. Adult hookworms (Necator spp.) collected from researchers working with wild western lowland gorillas

    Czech Academy of Sciences Publication Activity Database

    Kalousová, B.; Hasegawa, H.; Petrželková, Klára Judita; Sakamaki, T.; Kooriyma, T.; Modrý, D.

    2016-01-01

    Roč. 9, č. 75 (2016), č. článku 75. ISSN 1756-3305 R&D Projects: GA ČR GA15-05180S Institutional support: RVO:68081766 Keywords : Necator spp * Hookworm * Morphology * Human infection * Necator gorillae * Necator americanus Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.080, year: 2016

  11. Adult hookworms (Necator spp.) collected from researchers working with wild western lowland gorillas

    Czech Academy of Sciences Publication Activity Database

    Kalousová, B.; Hasegawa, H.; Petrželková, Klára Judita; Sakamaki, T.; Kooriyma, T.; Modrý, David

    2016-01-01

    Roč. 9, FEB 9 (2016), č. článku 75. ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Necator spp * Necator gorillae * Necator americanus * hookworm * morphology * human infection Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.080, year: 2016

  12. Biodegradable nanoparticle-entrapped vaccine induces cross-protective immune response against a virulent heterologous respiratory viral infection in pigs.

    Directory of Open Access Journals (Sweden)

    Varun Dwivedi

    Full Text Available Biodegradable nanoparticle-based vaccine development research is unexplored in large animals and humans. In this study, we illustrated the efficacy of nanoparticle-entrapped UV-killed virus vaccine against an economically important respiratory viral disease of pigs called porcine reproductive and respiratory syndrome virus (PRRSV. We entrapped PLGA [poly (lactide-co-glycolides] nanoparticles with killed PRRSV antigens (Nano-KAg and detected its phagocytosis by pig alveolar macrophages. Single doses of Nano-KAg vaccine administered intranasally to pigs upregulated innate and PRRSV specific adaptive responses. In a virulent heterologous PRRSV challenge study, Nano-KAg vaccine significantly reduced the lung pathology and viremia, and the viral load in the lungs. Immunologically, enhanced innate and adaptive immune cell population and associated cytokines with decreased secretion of immunosuppressive mediators were observed at both mucosal sites and blood. In summary, we demonstrated the benefits of intranasal delivery of nanoparticle-based viral vaccine in eliciting cross-protective immune response in pigs, a potential large animal model.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. Interaction of hookworm 14-3-3 with the forkhead transcription factor DAF-16 requires intact Akt phosphorylation sites

    Directory of Open Access Journals (Sweden)

    Hawdon John M

    2009-04-01

    Full Text Available Abstract Background Third-stage infective larvae (L3 of hookworms are in an obligatory state of developmental arrest that ends upon entering the definitive host, where they receive a signal that re-activates development. Recovery from the developmentally arrested dauer stage of Caenorhabditis elegans is analogous to the resumption of development during hookworm infection. Insulin-like signaling (ILS mediates recovery from arrest in C. elegans and activation of hookworm dauer L3. In C. elegans, phosphorylation of the forkhead transcription factor DAF-16 in response to ILS creates binding cites for the 14-3-3 protein Ce-FTT-2, which translocates DAF-16 out of the nucleus, resulting in resumption of reproductive development. Results To determine if hookworm 14-3-3 proteins play a similar role in L3 activation, hookworm FTT-2 was identified and tested for its ability to interact with A. caninum DAF-16 in vitro. The Ac-FTT-2 amino acid sequence was 91% identical to the Ce-FTT-2, and was most closely related to FTT-2 from other nematodes. Ac-FTT-2 was expressed in HEK 293T cells, and was recognized by an antibody against human 14-3-3β isoform. Reciprocal co-immunoprecipitations using anti-epitope tag antibodies indicated that Ac-FTT-2 interacts with Ac-DAF-16 when co-expressed in serum-stimulated HEK 293T cells. This interaction requires intact Akt consensus phosphorylation sites at serine107 and threonine312, but not serine381. Ac-FTT-2 was undetectable by Western blot in excretory/secretory products from serum-stimulated (activated L3 or adult A. caninum. Conclusion The results indicate that Ac-FTT-2 interacts with DAF-16 in a phosphorylation-site dependent manner, and suggests that Ac-FTT-2 mediates activation of L3 by binding Ac-DAF-16 during hookworm infection.

  15. Efficacy and safety of tribendimidine, tribendimidine plus ivermectin, tribendimidine plus oxantel pamoate, and albendazole plus oxantel pamoate against hookworm and concomitant soil-transmitted helminth infections in Tanzania and Côte d'Ivoire: a randomised, controlled, single-blinded, non-inferiority trial.

    Science.gov (United States)

    Moser, Wendelin; Coulibaly, Jean T; Ali, Said M; Ame, Shaali M; Amour, Amour K; Yapi, Richard B; Albonico, Marco; Puchkov, Maxim; Huwyler, Jörg; Hattendorf, Jan; Keiser, Jennifer

    2017-11-01

    Preventive chemotherapy is the current strategy to control soil-transmitted helminth infections (caused by Ascaris lumbricoides, hookworm, and Trichuris trichiura). But, to improve efficacy and avoid emerging resistance, new drugs are warranted. Tribendimidine has shown good anthelmintic efficacy and is therefore a frontrunner for monotherapy and combination chemotherapy. We did a randomised, controlled, single-blinded, non-inferiority trial on Pemba Island, Tanzania, and in Côte d'Ivoire. We recruited adolescents aged 15-18 years from four primary schools on Pemba, and school attendees and non-schoolers from two districts in Côte d'Ivoire. Only hookworm-positive participants were randomly assigned (1:1:1:1) to single, oral doses of tribendimidine 400 mg plus placebo (tribendimidine monotherapy), tribendimidine 400 mg plus ivermectin 200 μg/kg, tribendimidine 400 mg plus oxantel pamoate 25 mg/kg, or albendazole 400 mg plus oxantel pamoate 25 mg/kg. Randomisation was done via a computer-generated list in block sizes of four or eight. Participants were asked to provide two stool samples on 2 consecutive days at baseline and again 14-21 days at follow-up. The primary outcome was the difference in egg-reduction rates (ERRs; ie, the geometric mean reduction) in hookworm egg counts between treatment groups, measured by the Kato-Katz technique. Differences in coadministrated treatment groups were assessed for non-inferiority with a margin of -3% to albendazole plus oxantel pamoate based on the available-case population, analysed by intention to treat. Safety was assessed 3 h and 24 h after treatment. This study is registered with ISRCTN (number 14373201). Between July 26, and Dec 23, 2016, we treated 636 hookworm-positive participants, and outcome data were available for 601 participants (151 assigned to tribendimidine monotherapy, 154 to tribendimidine plus ivermectin, 148 to tribendimidine plus oxantel pamoate, and 148 to albendazole plus oxantel pamoate

  16. Prevalence of Hookworms, Uncinaria Lucasi (Ancylostomatidae, In Northern Fur Seals (Callorhinus Ursinus On St. Paul Island, Alaska

    Directory of Open Access Journals (Sweden)

    Lyons E.T.

    2014-07-01

    Full Text Available Prevalence of Hookworms, Uncinaria lucasi (Ancylostomatidae, in Northern Fur Seals (Callorhinus ursinus on St. Paul Island, Alaska. Lyons, E. T., Kuzmina, T. A., Carie, J. L., Tolliver, S. C., Spraker, T. R. — Review of main studies on biology and ecology of the hookworm Uncinaria lucasi Stiles, 1901 performed on St. Paul Island, Alaska, is presented. Current data on prevalence of adult hookworms parasitizing northern fur seals (NFS, Callorhinus ursinus Linnaeus, 1758, were obtained based on the examination of the intestines of dead NFS pups and subadult 3-4 year-old males in July and August of 2011-2013. In addition, blubber samples collected from subadult NFS males were examined for parasitic third stage hookworm larvae (L3. All current data were compared with previously published studies performed in 1950s-1960s. Current prevalence of U. lucasi in dead pups collected from Reef Rookery was 4.9 % in 2011, 0 % in 2012 and 10.5 % in 2013. This rookery has a rocky substrate. On sandy rookeries prevalence was up to 75 % on Morjovi Rookery and 50 % on Vostochni Rookery. Parasitic L3 were recovered in 2.5 % of subadult males examined in 2013. Decreasing prevalence of hookworm infection of dead pups and subadult males during the last several years follows the tremendous decline in the number of fur seals in the herd on St. Paul Island during last several decades.

  17. Comparison of culture-based, vital stain and PMA-qPCR methods for the quantitative detection of viable hookworm ova.

    Science.gov (United States)

    Gyawali, P; Sidhu, J P S; Ahmed, W; Jagals, P; Toze, S

    2017-06-01

    Accurate quantitative measurement of viable hookworm ova from environmental samples is the key to controlling hookworm re-infections in the endemic regions. In this study, the accuracy of three quantitative detection methods [culture-based, vital stain and propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR)] was evaluated by enumerating 1,000 ± 50 Ancylostoma caninum ova in the laboratory. The culture-based method was able to quantify an average of 397 ± 59 viable hookworm ova. Similarly, vital stain and PMA-qPCR methods quantified 644 ± 87 and 587 ± 91 viable ova, respectively. The numbers of viable ova estimated by the culture-based method were significantly (P methods. Therefore, both PMA-qPCR and vital stain methods appear to be suitable for the quantitative detection of viable hookworm ova. However, PMA-qPCR would be preferable over the vital stain method in scenarios where ova speciation is needed.

  18. The hookworm Ancylostoma ceylanicum: An emerging public health risk in Australian tropical rainforests and Indigenous communities.

    Science.gov (United States)

    Smout, Felicity A; Skerratt, Lee F; Butler, James R A; Johnson, Christopher N; Congdon, Bradley C; Thompson, R C Andrew

    2017-06-01

    Ancylostoma ceylanicum is the common hookworm of domestic dogs and cats throughout Asia, and is an emerging but little understood public health risk in tropical northern Australia. We investigated the prevalence of A. ceylanicum in soil and free-ranging domestic dogs at six rainforest locations in Far North Queensland that are Indigenous Australian communities and popular tourist attractions within the Wet Tropics World Heritage Area. By combining PCR-based techniques with traditional methods of hookworm species identification, we found the prevalence of hookworm in Indigenous community dogs was high (96.3% and 91.9% from necropsy and faecal samples, respectively). The majority of these infections were A. caninum. We also observed, for the first time, the presence of A. ceylanicum infection in domestic dogs (21.7%) and soil (55.6%) in an Indigenous community. A. ceylanicum was present in soil samples from two out of the three popular tourist locations sampled. Our results contribute to the understanding of dogs as a public health risk to Indigenous communities and tourists in the Wet Tropics. Dog health needs to be more fully addressed as part of the Australian Government's commitments to "closing the gap" in chronic disease between Indigenous and other Australians, and encouraging tourism in similar locations.

  19. The hookworm Ancylostoma ceylanicum: An emerging public health risk in Australian tropical rainforests and Indigenous communities

    Directory of Open Access Journals (Sweden)

    Felicity A. Smout

    2017-06-01

    Full Text Available Ancylostoma ceylanicum is the common hookworm of domestic dogs and cats throughout Asia, and is an emerging but little understood public health risk in tropical northern Australia. We investigated the prevalence of A. ceylanicum in soil and free-ranging domestic dogs at six rainforest locations in Far North Queensland that are Indigenous Australian communities and popular tourist attractions within the Wet Tropics World Heritage Area. By combining PCR-based techniques with traditional methods of hookworm species identification, we found the prevalence of hookworm in Indigenous community dogs was high (96.3% and 91.9% from necropsy and faecal samples, respectively. The majority of these infections were A. caninum. We also observed, for the first time, the presence of A. ceylanicum infection in domestic dogs (21.7% and soil (55.6% in an Indigenous community. A. ceylanicum was present in soil samples from two out of the three popular tourist locations sampled. Our results contribute to the understanding of dogs as a public health risk to Indigenous communities and tourists in the Wet Tropics. Dog health needs to be more fully addressed as part of the Australian Government's commitments to “closing the gap” in chronic disease between Indigenous and other Australians, and encouraging tourism in similar locations.

  20. Transgenic C. elegans dauer larvae expressing hookworm phospho null DAF-16/FoxO exit dauer.

    Directory of Open Access Journals (Sweden)

    Verena Gelmedin

    Full Text Available Parasitic hookworms and the free-living model nematode Caenorhabtidis elegans share a developmental arrested stage, called the dauer stage in C. elegans and the infective third-stage larva (L3 in hookworms. One of the key transcription factors that regulate entrance to and exit from developmental arrest is the forkhead transcription factor DAF-16/FoxO. During the dauer stage, DAF-16 is activated and localized in the nucleus. DAF-16 is negatively regulated by phosphorylation by the upstream kinase AKT, which causes DAF-16 to localize out of the nucleus and the worm to exit from dauer. DAF-16 is conserved in hookworms, and hypothesized to control recovery from L3 arrest during infection. Lacking reverse genetic techniques for use in hookworms, we used C. elegans complementation assays to investigate the function of Ancylostoma caninum DAF-16 during entrance and exit from L3 developmental arrest. We performed dauer switching assays and observed the restoration of the dauer phenotype when Ac-DAF-16 was expressed in temperature-sensitive dauer defective C. elegans daf-2(e1370;daf-16(mu86 mutants. AKT phosphorylation site mutants of Ac-DAF-16 were also able to restore the dauer phenotype, but surprisingly allowed dauer exit when temperatures were lowered. We used fluorescence microscopy to localize DAF-16 during dauer and exit from dauer in C. elegans DAF-16 mutant worms expressing Ac-DAF-16, and found that Ac-DAF-16 exited the nucleus during dauer exit. Surprisingly, Ac-DAF-16 with mutated AKT phosphorylation sites also exited the nucleus during dauer exit. Our results suggest that another mechanism may be involved in the regulation DAF-16 nuclear localization during recovery from developmental arrest.

  1. Comparison of immune responses after intra-typic heterologous and homologous vaccination against foot-and-mouth disease virus infection in pigs

    NARCIS (Netherlands)

    Eble, P.L.; Bruin, de M.G.M.; Bouma, A.; Hemert-Kluitenberg, van F.; Dekker, A.

    2006-01-01

    This study compares the immune responses and protection induced by intra-typic heterologous vaccination with that induced by homologous vaccination against challenge with foot-and-mouth disease virus (FMDV). Humoral and cell-mediated immune responses and protection against challenge with FMDV O

  2. Safety and immunogenicity of the Na-GST-1 hookworm vaccine in Brazilian and American adults.

    Directory of Open Access Journals (Sweden)

    David J Diemert

    2017-05-01

    Full Text Available Necator americanus Glutathione-S-Transferase-1 (Na-GST-1 plays a role in the digestion of host hemoglobin by adult N. americanus hookworms. Vaccination of laboratory animals with recombinant Na-GST-1 is associated with significant protection from challenge infection. Recombinant Na-GST-1 was expressed in Pichia pastoris and adsorbed to aluminum hydroxide adjuvant (Alhydrogel according to current Good Manufacturing Practice. Two Phase 1 trials were conducted in 142 healthy adult volunteers in the United States and Brazil, first in hookworm-naïve individuals and then in residents of a N. americanus endemic area in Brazil. Volunteers received one of three doses of recombinant Na-GST-1 (10, 30, or 100 μg adjuvanted with Alhydrogel, adjuvanted with Alhydrogel and co-administered with an aqueous formulation of Glucopyranosyl Lipid A (GLA-AF, or the hepatitis B vaccine. Vaccinations were administered via intramuscular injection on days 0, 56, and 112. Na-GST-1/Alhydrogel was well tolerated in both hookworm-naïve and hookworm-exposed adults, with the most common adverse events being mild to moderate injection site pain and tenderness, and mild headache and nausea; no vaccine-related severe or serious adverse events were observed. Antigen-specific IgG antibodies were induced in a dose-dependent fashion, with increasing levels observed after each vaccination in both trials. The addition of GLA-AF to Na-GST-1/Alhydrogel did not result in significant increases in specific IgG responses. In both the US and Brazil studies, the predominant IgG subclass induced against Na-GST-1 was IgG1, with lesser amounts of IgG3. Vaccination of both hookworm-naïve and hookworm-exposed adults with recombinant Na-GST-1 was safe, well tolerated, and resulted in significant antigen-specific IgG responses. Based on these results, this vaccine will be advanced into clinical trials in children and eventual efficacy studies.ClinicalTrials.gov (NCT01261130 for the Brazil trial

  3. Immunization with Brugia malayi Myosin as Heterologous DNA Prime Protein Boost Induces Protective Immunity against B. malayi Infection in Mastomys coucha.

    Directory of Open Access Journals (Sweden)

    Jyoti Gupta

    Full Text Available The current control strategies employing chemotherapy with diethylcarbamazine, ivermectin and albendazole have reduced transmission in some filaria-endemic areas, there is growing interest for complementary approaches, such as vaccines especially in light of threat of parasite developing resistance to mainstay drugs. We earlier demonstrated recombinant heavy chain myosin of B. malayi (Bm-Myo as a potent vaccine candidate whose efficacy was enhanced by heterologous DNA prime/protein boost (Myo-pcD+Bm-Myo vaccination in BALB/c mice. BALB/c mouse though does not support the full developmental cycle of B. malayi, however, the degree of protection may be studied in terms of transformation of challenged infective larvae (L3 to next stage (L4 with an ease of delineating the generated immunological response of host. In the current investigation, DNA vaccination with Bm-Myo was therefore undertaken in susceptible rodent host, Mastomys coucha (M. coucha which sustains the challenged L3 and facilitates their further development to sexually mature adult parasites with patent microfilaraemia. Immunization schedule consisted of Myo-pcD and Myo-pcD+Bm-Myo followed by B. malayi L3 challenge and the degree of protection was evaluated by observing microfilaraemia as well as adult worm establishment. Myo-pcD+Bm-Myo immunized animals not only developed 78.5% reduced blood microfilarial density but also decreased adult worm establishment by 75.3%. In addition, 75.4% of the recovered live females revealed sterilization over those of respective control animals. Myo-pcD+Bm-Myo triggered higher production of specific IgG and its isotypes which induced marked cellular adhesion and cytotoxicity (ADCC to microfilariae (mf and L3 in vitro. Both Th1 and Th2 cytokines were significantly up-regulated displaying a mixed immune response conferring considerable protection against B. malayi establishment by engendering a long-lasting effective immune response and therefore emerges

  4. Detection of Helminth Eggs and Identification of Hookworm Species in Stray Cats, Dogs and Soil from Klang Valley, Malaysia.

    Directory of Open Access Journals (Sweden)

    Sandee Tun

    Full Text Available The present study was conducted to determine the prevalence of helminth eggs excreted in the faeces of stray cats, dogs and in soil samples. A total of 505 fresh samples of faeces (from 227 dogs and 152 cats and soil were collected. The egg stage was detected via microscopy after the application of formalin-ether concentration technique. Genomic DNA was extracted from the samples containing hookworm eggs and used for further identification to the species level using real-time polymerase chain reaction coupled with high resolution melting analysis. Microscopic observation showed that the overall prevalence of helminth eggs among stray cats and dogs was 75.7% (95% CI = 71.2%-79.9%, in which 87.7% of dogs and 57.9% of cats were infected with at least one parasite genus. Five genera of heliminth eggs were detected in the faecal samples, including hookworms (46.4%, Toxocara (11.1%, Trichuris (8.4%, Spirometra (7.4% and Ascaris (2.4%. The prevalence of helminth infections among stray dogs was significantly higher than that among stray cats (p < 0.001. Only three genera of helminths were detected in soil samples with the prevalence of 23% (95% CI = 15.1%-31%, consisting of hookworms (16.6%, Ascaris (4% and Toxocara (2.4%. The molecular identification of hookworm species revealed that Ancylostoma ceylanicum was dominant in both faecal and soil samples. The dog hookworm, Ancylostoma caninum, was also detected among cats, which is the first such occurrence reported in Malaysia till date. This finding indicated that there was a cross-infection of A. caninum between stray cats and dogs because of their coexistent within human communities. Taken together, these data suggest the potential role of stray cats and dogs as being the main sources of environmental contamination as well as for human infections.

  5. Analysing risk factors of co-occurrence of schistosomiasis haematobium and hookworm using bivariate regression models: Case study of Chikwawa, Malawi

    Directory of Open Access Journals (Sweden)

    Bruce B.W. Phiri

    2016-06-01

    Full Text Available Schistosomiasis and soil-transmitted helminth (STH infections constitute a major public health problem in many parts of sub-Saharan Africa. In areas where prevalence of geo-helminths and schistosomes is high, co-infection with multiple parasite species is common, resulting in disproportionately elevated burden compared with single infections. Determining risk factors of co-infection intensity is important for better design of targeted interventions. In this paper, we examined risk factors of hookworm and S. haematobium co-infection intensity, in Chikwawa district, southern Malawi in 2005, using bivariate count models. Results show that hookworm and S. haematobium infections were much localised with small proportion of individuals harbouring more parasites especially among school-aged children. The risk of co-intensity with both hookworm and S. haematobium was high for all ages, although this diminished with increasing age, increased with fishing (hookworm: coefficient. = 12.29; 95% CI = 11.50–13.09; S. haematobium: 0.040; 95% CI = 0.0037, 3.832. Both infections were abundant in those with primary education (hookworm: coef. = 0.072; 95% CI = 0.056, 0.401 and S. haematobium: coef. = 0.286; 95% CI = 0.034, 0.538. However, much lower risk was observed for those who were farmers (hookworm: coef. = −0.349, 95% CI = −0.547,−0.150; S. haematobium: coef. −0.239, 95% CI = −0.406, −0.072. In conclusion, our findings suggest that efforts to control helminths infection should be co-integrated and health promotion campaigns should be aimed at school-going children and adults who are in constant contact with water.

  6. Vaccination against porcine parvovirus protects against disease, but does not prevent infection and virus shedding after challenge infection with a heterologous virus strain.

    Science.gov (United States)

    Jóźwik, A; Manteufel, J; Selbitz, H-J; Truyen, U

    2009-10-01

    The demonstration of field isolates of porcine parvovirus (PPV) that differ genetically and antigenically from vaccine strains of PPV raises the question of whether the broadly used inactivated vaccines can still protect sows against the novel viruses. Ten specific-pathogen-free primiparous sows were assigned to three groups and were vaccinated with one of two vaccines based on the old vaccine strains, or served as non-vaccinated controls. After insemination, all sows were challenged with the prototype genotype 2 virus, PPV-27a, on gestation day 41; fetuses were delivered on gestation day 90 and examined for virus infection. The fetuses of the vaccinated sows were protected against disease, but both the vaccinated and the non-vaccinated sows showed a marked increase in antibody titres after challenge infection, indicating replication of the challenge virus. All sows (vaccinated and non-vaccinated) shed the challenge virus for at least 10 days after infection, with no difference in the pattern or duration of virus shedding.

  7. hookworm species distribution around asendabo town jimma zone

    African Journals Online (AJOL)

    DigLab

    acknowledged cause of anemia as a result of intestinal blood loss. The aim of this study was to ... KEY WORDS: Hookworm species, anemia, helminth, Asendabo, Jimma, Ethiopia. ... nematode parasites Necator americanus and Ancylostoma.

  8. Sanitation, hookworm, anemia, stunting, and wasting in primary school children in southern Ethiopia: Baseline results from a study in 30 schools.

    Science.gov (United States)

    Grimes, Jack E T; Tadesse, Gemechu; Gardiner, Iain A; Yard, Elodie; Wuletaw, Yonas; Templeton, Michael R; Harrison, Wendy E; Drake, Lesley J

    2017-10-01

    Inadequate nutrition; neglected topical diseases; and insufficient water, sanitation, and hygiene (WASH) are interrelated problems in schools in low-income countries, but are not routinely tackled together. A recent three-year longitudinal study investigated integrated school health and nutrition approaches in 30 government primary schools in southern Ethiopia. Here, we report on baseline associations between sanitation, hookworm infection, anemia, stunting, and wasting. In each school, the Schistosoma mansoni, S. haematobium, and soil-transmitted helminth infection intensities; blood hemoglobin concentrations; heights; and weights of approximately 125 students were assessed. Of these 125 students, approximately 20 were randomly selected for student WASH surveys. Of these 20, approximately 15 were randomly selected for household sanitation observations. School WASH was also assessed through a combination of observations and questions to the headteacher. Mixed-effects logistic regression was used to compare household sanitation with hookworm infection (the other parasites being much less prevalent); and hookworm infection with anemia, stunting, and wasting. Blood, stool, and urine samples were provided by 3,729 children, and student WASH and household WASH surveys were conducted with 596 and 448 of these students, respectively. Hookworm, Ascaris lumbricoides, Trichuris trichiura, and S. mansoni infections had prevalences of 18%, 4.8%, 0.6%, and 0.3%, respectively, and no S. haematobium infections were found. Anemia, stunting, and wasting had prevalences of 23%, 28%, and 14%, respectively. No statistically significant associations were found between latrine absence or evidence of open defecation at home, and hookworm infection (adjusted odds ratio, OR = 1.28, 95% confidence interval, CI: 0.476-3.44; and adjusted OR = 1.21, 95% CI: 0.468-3.12; respectively); or between hookworm infection and anemia, stunting, or wasting (adjusted OR = 1.24, 95% CI: 0

  9. The human hookworm vaccine: recent updates and prospects for success.

    Science.gov (United States)

    Bottazzi, M E

    2015-09-01

    Approximately 440 million people globally are afflicted by hookworm disease, one of the 17 WHO-recognized neglected tropical diseases (NTDs). The iron-deficiency anaemia attributed to this disease contributes to at least 3.2 million disability-adjusted life years (DALYs) according to the Global Burden of Disease Study 2010. The current WHO-recommended control strategies rely primarily on mass drug administration or preventive chemotherapy. However, evidence is starting to accumulate confirming that preventive chemotherapy alone will not be sufficient to reduce the reinfection rates of hookworm, especially in areas of heavy transmission. The global health and research community is currently building a consensus stressing the need for the advancement of research and innovation to bridge the gaps and identify new public health interventions for diseases such as hookworm and other NTDs. This paper presents the strategies used by the Sabin Vaccine Institute Product Development Partnership (Sabin PDP) in their ongoing endeavour for the development of a human hookworm vaccine. Recent updates and the current prospects for success of an effective human hookworm vaccine, as a new technology to be linked to or combined with drug interventions, are presented.

  10. Drug Repositioning and Pharmacophore Identification in the Discovery of Hookworm MIF Inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Y Cho; J Vermeire; J Merkel; L Leng; X Du; R Bucala; M Cappello; E Lolis

    2011-12-31

    The screening of bioactive compound libraries can be an effective approach for repositioning FDA-approved drugs or discovering new pharmacophores. Hookworms are blood-feeding, intestinal nematode parasites that infect up to 600 million people worldwide. Vaccination with recombinant Ancylostoma ceylanicum macrophage migration inhibitory factor (rAceMIF) provided partial protection from disease, thus establishing a 'proof-of-concept' for targeting AceMIF to prevent or treat infection. A high-throughput screen (HTS) against rAceMIF identified six AceMIF-specific inhibitors. A nonsteroidal anti-inflammatory drug (NSAID), sodium meclofenamate, could be tested in an animal model to assess the therapeutic efficacy in treating hookworm disease. Furosemide, an FDA-approved diuretic, exhibited submicromolar inhibition of rAceMIF tautomerase activity. Structure-activity relationships of a pharmacophore based on furosemide included one analog that binds similarly to the active site, yet does not inhibit the Na-K-Cl symporter (NKCC1) responsible for diuretic activity.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-01

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

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

    International Nuclear Information System (INIS)

    Asojo, Oluwatoyin A.

    2011-01-01

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

  13. Identification, isolation, and molecular cloning of a hookworm protease: an approach towards a defined vaccine for ancylostomiasis

    Energy Technology Data Exchange (ETDEWEB)

    Hotez, P.J.

    1985-01-01

    The hookworm Ancylostoma caninum was shown to release in vitro a 37 kDa protease that catalyzed the hydrolysis of fibrinogen, plasminogen, and elastin. The enzyme was purified from parasite extracts by ion-exchange chromatography, followed by gel filtration and hydrophobic interaction chromatography. An amino-terminal sequence was determined. When assayed with radiolabeled fibrin as substrate, the enzyme displayed optimal activity at pH 9-11; it was inactivated by dialysis against ethylenediamine tetraacetic acid. Antiserum raised against the protease in rabbits cross-reacted on western blots with soluble antigen from the infective larval stage of the parasite. A cDNA library from hookworm mRNA was constructed in the expression vector bacteriophage lambdagtll. A positive clone was identified with the rabbit antiserum that was shown to contain an 800-bp insert. The insert was mapped, subcloned into M13, and sequenced, revealing an open reading frame of 789 nucleotides corresponding to 263 amino acids.

  14. Health Education through Analogies: Preparation of a Community for Clinical Trials of a Vaccine against Hookworm in an Endemic Area of Brazil

    Science.gov (United States)

    Gazzinelli, Maria Flavia; Lobato, Lucas; Matoso, Leonardo; Avila, Renato; de Cassia Marques, Rita; Shah Brown, Ami; Correa-Oliveira, Rodrigo; Bethony, Jeffrey M.; Diemert, David J.

    2010-01-01

    Background Obtaining informed consent for clinical trials is especially challenging when working in rural, resource-limited areas, where there are often high levels of illiteracy and lack of experience with clinical research. Such an area, a remote field site in the northeastern part of the state of Minas Gerais, Brazil, is currently being prepared for clinical trials of experimental hookworm vaccines. This study was conducted to assess whether special educational tools can be developed to increase the knowledge and comprehension of potential clinical trial participants and thereby enable them to make truly informed decisions to participate in such research. Methodology/Principal Findings An informational video was produced to explain the work of the research team and the first planned hookworm vaccine trial, using a pedagogical method based on analogies. Seventy-two adults living in a rural community of Minas Gerais were administered a structured questionnaire that assessed their knowledge of hookworm, of research and of the planned hookworm vaccine trial, as well as their attitudes and perceptions about the researchers and participation in future vaccine trials. The questionnaire was administered before being shown the educational video and two months after and the results compared. After viewing the video, significant improvements in knowledge related to hookworm infection and its health impact were observed: using a composite score combining related questions for which correct answers were assigned a value of 1 and incorrect answers a value of 0, participants had a mean score of 0.76 post-video compared to 0.68 pre-video (p = 0.0001). Similar improvements were seen in understanding the purpose of vaccination and the possible adverse effects of an experimental vaccine. Although 100% of participants expressed a positive opinion of the researchers even before viewing the film and over 90% said that they would participate in a hookworm vaccine trial, an

  15. Health education through analogies: preparation of a community for clinical trials of a vaccine against hookworm in an endemic area of Brazil.

    Directory of Open Access Journals (Sweden)

    Maria Flavia Gazzinelli

    Full Text Available BACKGROUND: Obtaining informed consent for clinical trials is especially challenging when working in rural, resource-limited areas, where there are often high levels of illiteracy and lack of experience with clinical research. Such an area, a remote field site in the northeastern part of the state of Minas Gerais, Brazil, is currently being prepared for clinical trials of experimental hookworm vaccines. This study was conducted to assess whether special educational tools can be developed to increase the knowledge and comprehension of potential clinical trial participants and thereby enable them to make truly informed decisions to participate in such research. METHODOLOGY/PRINCIPAL FINDINGS: An informational video was produced to explain the work of the research team and the first planned hookworm vaccine trial, using a pedagogical method based on analogies. Seventy-two adults living in a rural community of Minas Gerais were administered a structured questionnaire that assessed their knowledge of hookworm, of research and of the planned hookworm vaccine trial, as well as their attitudes and perceptions about the researchers and participation in future vaccine trials. The questionnaire was administered before being shown the educational video and two months after and the results compared. After viewing the video, significant improvements in knowledge related to hookworm infection and its health impact were observed: using a composite score combining related questions for which correct answers were assigned a value of 1 and incorrect answers a value of 0, participants had a mean score of 0.76 post-video compared to 0.68 pre-video (p = 0.0001. Similar improvements were seen in understanding the purpose of vaccination and the possible adverse effects of an experimental vaccine. Although 100% of participants expressed a positive opinion of the researchers even before viewing the film and over 90% said that they would participate in a hookworm vaccine

  16. coinfection with malaria, hookworm and schistosomiasis among

    African Journals Online (AJOL)

    Esem

    Schistosomiasis among School Children in Zambezi: A School-based ... positive at least to one parasitic infection. Estimated .... coinfections did not differ significantly by age and sex with the ..... Efficacy of integrated school based deworming ...

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-01

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

  19. Feleke et al., Afr., J. Infect. Dis.

    African Journals Online (AJOL)

    user

    2017-11-15

    Nov 15, 2017 ... Background: Anemia is an indicator of both poor nutrition and health. ... Intestinal parasitosis infections and hemoglobin level were determined by formula ether concentration ... education, family size and hookworm infection.

  20. Detection of Helminth Eggs and Identification of Hookworm Species in Stray Cats, Dogs and Soil from Klang Valley, Malaysia.

    Science.gov (United States)

    Tun, Sandee; Ithoi, Init; Mahmud, Rohela; Samsudin, Nur Izyan; Kek Heng, Chua; Ling, Lau Yee

    2015-01-01

    The present study was conducted to determine the prevalence of helminth eggs excreted in the faeces of stray cats, dogs and in soil samples. A total of 505 fresh samples of faeces (from 227 dogs and 152 cats) and soil were collected. The egg stage was detected via microscopy after the application of formalin-ether concentration technique. Genomic DNA was extracted from the samples containing hookworm eggs and used for further identification to the species level using real-time polymerase chain reaction coupled with high resolution melting analysis. Microscopic observation showed that the overall prevalence of helminth eggs among stray cats and dogs was 75.7% (95% CI = 71.2%-79.9%), in which 87.7% of dogs and 57.9% of cats were infected with at least one parasite genus. Five genera of heliminth eggs were detected in the faecal samples, including hookworms (46.4%), Toxocara (11.1%), Trichuris (8.4%), Spirometra (7.4%) and Ascaris (2.4%). The prevalence of helminth infections among stray dogs was significantly higher than that among stray cats (p dog hookworm, Ancylostoma caninum, was also detected among cats, which is the first such occurrence reported in Malaysia till date. This finding indicated that there was a cross-infection of A. caninum between stray cats and dogs because of their coexistent within human communities. Taken together, these data suggest the potential role of stray cats and dogs as being the main sources of environmental contamination as well as for human infections.

  1. Ascaris and hookworm transmission in preschool children from rural Panama: role of yard environment, soil eggs/larvae and hygiene and play behaviours.

    Science.gov (United States)

    Krause, Rachel J; Koski, Kristine G; Pons, Emérita; Sandoval, Nidia; Sinisterra, Odalis; Scott, Marilyn E

    2015-10-01

    This study explored whether the yard environment and child hygiene and play behaviours were associated with presence and intensity of Ascaris and hookworm in preschool children and with eggs and larvae in soil. Data were collected using questionnaires, a visual survey of the yard, soil samples and fecal samples collected at baseline and following re-infection. The presence of eggs/larvae in soil was associated negatively with water storage (eggs) but positively with dogs (eggs) and distance from home to latrine (larvae). Baseline and re-infection prevalences were: hookworm (28.0%, 3.4%); Ascaris (16.9%, 9.5%); Trichuris (0.9%, 0.7%). Zero-inflated negative binomial regression models revealed a higher baseline hookworm infection if yards had eggs or larvae, more vegetation or garbage, and if the child played with soil. Baseline Ascaris was associated with dirt floor, dogs, exposed soil in yard, open defecation and with less time playing outdoors, whereas Ascaris re-infection was associated with water storage, vegetation cover and garbage near the home and not playing with animals. Our results show complex interactions between infection, the yard environment and child behaviours, and indicate that transmission would be reduced if latrines were closer to the home, and if open defecation and water spillage were reduced.

  2. Antibody responses in pregnancy-induced transmammary transmission of Ancylostoma caninum hookworm larvae.

    Science.gov (United States)

    Arasu, P; Heller, A

    1999-09-20

    Third stage larvae of the Ancylostoma caninum hookworm nematode have the capacity to infect a dog, abort the normal maturation pathway to become blood-feeding intestinal worms, and instead distribute throughout the body in a developmentally arrested state that is relatively resilient to most chemotherapeutic agents. During pregnancy, a percentage of the arrested larvae reactivate and transmit via the mammary glands to infect the nursing puppies with resulting iron-deficiency anemia and potential mortality. To determine if the suppression of parasite-specific antibody responses during pregnancy facilitates the reactivation and transmammary transfer of hookworm larvae, a murine model of A. caninum infection was used to compare the infected versus uninfected animals that were either bred or not bred. Initial comparisons of genetically divergent BALB/c versus C57BL/6 mice showed that both the strains mounted strong Th2 biased IgG1 and IgE antibody responses to A. caninum infection. Using the BALB/c strain for the breeding analyses, it was confirmed that larval transfer to the mouse pups only occurred during the post-partum lactational period. In the dams, levels of total and antigen-specific IgG1 and total IgE were highly correlated with parasite burden. During most phases of pregnancy and lactation, infected dams had lower total IgG1, IgG2a and IgE levels as compared to unbred mice at comparable times post-infection; this downward modulation of antibody responses supports the established dogma of a generalized immunosuppression associated with pregnancy. However, at parturition and post-partum lactation, antigen-specific IgG1 levels measured at 1:5000 serum dilutions were comparable between bred and unbred mice, and antigen-specific IgG2a levels at 1:100 serum dilutions were also not significantly different except for a marginal reduction in the bred mice at the lactational timepoint. The comparable anti-A. caninum IgG1 levels between bred and unbred mice, and low

  3. Photosynthetic fuel for heterologous enzymes

    DEFF Research Database (Denmark)

    Mellor, Silas Busck; Vavitsas, Konstantinos; Nielsen, Agnieszka Janina Zygadlo

    2017-01-01

    of reducing power. Recent work on the metabolic engineering of photosynthetic organisms has shown that the electron carriers such as ferredoxin and flavodoxin can be used to couple heterologous enzymes to photosynthetic reducing power. Because these proteins have a plethora of interaction partners and rely...... on electrostatically steered complex formation, they form productive electron transfer complexes with non-native enzymes. A handful of examples demonstrate channeling of photosynthetic electrons to drive the activity of heterologous enzymes, and these focus mainly on hydrogenases and cytochrome P450s. However......, competition from native pathways and inefficient electron transfer rates present major obstacles, which limit the productivity of heterologous reactions coupled to photosynthesis. We discuss specific approaches to address these bottlenecks and ensure high productivity of such enzymes in a photosynthetic...

  4. Molecular identification of zoonotic hookworm species in dog faeces from Tanzania

    DEFF Research Database (Denmark)

    Merino-Tejedor, A.; Nejsum, P.; Mkupasi, E. M.

    2018-01-01

    The presence and distribution of various species of canine hookworms in Africa are poorly known. The main objective of this study, therefore, was to identify the hookworm species present in canine faecal samples from Morogoro, Tanzania, using molecular techniques. Faecal samples from 160 local do...

  5. Hookworm-like eggs in children's faecal samples from a rural area of ...

    African Journals Online (AJOL)

    Larvae of C. elegans in water drop from the coprocultive (vision through electronic loupe). Discussion. A brief review of other studies showed frequent prob- lems in the identification of hookworm eggs by micros- copy. It is often reported as misdiagnosis of hookworm eggs with other nematode species. Some researchers14- ...

  6. Assessing the speed of kill of hookworms, Ancylostoma caninum, by Advantage Multi ® for Dogs using endoscopic methods.

    Science.gov (United States)

    Lee, Alice C Y; Hostetler, Joseph A; Bowman, Dwight D

    2014-08-29

    Endoscopic capsules and endoscopy were used to assess the speed of kill and the clearance of hookworms in dogs experimentally infected with Ancylostoma caninum. A total of four adult dogs were inoculated in two separate cohorts comprised of two 4-year-old females and two 7-year-old males. Dogs were treated topically with Advantage Multi(®) for Dogs 13 days (Cohort 1) or 16 days (Cohort 2) after infection. Endoscopic imaging of the small intestine was carried out both pre- and post-treatment. Examination of the first cohort revealed that the worms had been cleared and the hookworm-induced lacerations were markedly diminished within 48 h of treatment. In the second cohort, endoscopic capsules were given the day of, the day after, and two days after treatment; within 24h of product administration, the worms had been removed with a concurrent reduction in observed lesions. Topical application of Advantage Multi(®) for Dogs rapidly removed worms from the small intestine of the dogs in this study as early as 24h post-treatment, with a marked reduction in the number of mucosal lesions seen. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Activity of oxantel pamoate monotherapy and combination chemotherapy against Trichuris muris and hookworms: revival of an old drug.

    Directory of Open Access Journals (Sweden)

    Jennifer Keiser

    Full Text Available BACKGROUND: It is widely recognized that only a handful of drugs are available against soil-transmitted helminthiasis, all of which are characterized by a low efficacy against Trichuris trichiura, when administered as single doses. The re-evaluation of old, forgotten drugs is a promising strategy to identify alternative anthelminthic drug candidates or drug combinations. METHODOLOGY: We studied the activity of the veterinary drug oxantel pamoate against Trichuris muris, Ancylostoma ceylanicum and Necator americanus in vitro and in vivo. In addition, the dose-effect of oxantel pamoate combined with albendazole, mebendazole, levamisole, pyrantel pamoate and ivermectin was studied against T. muris in vitro and additive or synergistic combinations were followed up in vivo. PRINCIPAL FINDINGS: We calculated an ED50 of 4.7 mg/kg for oxantel pamoate against T. muris in mice. Combinations of oxantel pamoate with pyrantel pamoate behaved antagonistically in vitro (combination index (CI = 2.53. Oxantel pamoate combined with levamisole, albendazole or ivermectin using ratios based on their ED50s revealed antagonistic effects in vivo (CI = 1.27, 1.90 and 1.27, respectively. A highly synergistic effect (CI = 0.15 was observed when oxantel pamoate-mebendazole was administered to T. muris-infected mice. Oxantel pamoate (10 mg/kg lacked activity against Ancylostoma ceylanicum and Necator americanus in vivo. CONCLUSION/SIGNIFICANCE: Our study confirms the excellent trichuricidal properties of oxantel pamoate. Since the drug lacks activity against hookworms it is necessary to combine oxantel pamoate with a partner drug with anti-hookworm properties. Synergistic effects were observed for oxantel pamoate-mebendazole, hence this combination should be studied in more detail. Since, of the standard drugs, albendazole has the highest efficacy against hookworms, additional investigations on the combination effect of oxantel pamoate-albendazole should be

  8. Soil-Transmitted Helminth Infections and Schistosomiasis mansoni ...

    African Journals Online (AJOL)

    user

    Hookworm infection is a public health problem of great ... medical aid in Ethiopia. Although .... respectively, are reported for the first time from this .... Helminths also impair the mental and physical ... Gebre Manual T. Human Wastes. Disposal.

  9. Method for determining heterologous biosynthesis pathways

    KAUST Repository

    Gao, Xin

    2017-08-10

    The present invention relates to a method and system for dynamically analyzing, determining, predicting and displaying ranked suitable heterologous biosynthesis pathways for a specified host. The present invention addresses the problem of finding suitable pathways for the endogenous metabolism of a host organism because the efficacy of heterologous biosynthesis is affected by competing endogenous pathways. The present invention is called MRE (Metabolic Route Explorer), and it was conceived and developed to systematically and dynamically search for, determine, analyze, and display promising heterologous pathways while considering competing endogenous reactions in a given host organism.

  10. for presence of hookworms (Uncinaria spp. on San Miguel Island, California

    Directory of Open Access Journals (Sweden)

    Lyons E. T.

    2016-06-01

    Full Text Available Necropsy and extensive parasitological examination of dead northern elephant seal (NES pups was done on San Miguel Island, California, in February, 2015. The main interest in the current study was to determine if hookworms were present in NESs on San Miguel Island where two hookworm species of the genus Uncinaria are known to be present - Uncinaria lyonsi in California sea lions and Uncinaria lucasi in northern fur seals. Hookworms were not detected in any of the NESs examined: stomachs or intestines of 16 pups, blubber of 13 pups and blubber of one bull. The results obtained in the present study of NESs on San Miguel Island plus similar finding on Año Nuevo State Reserve and The Marine Mammal Center provide strong indication that NES are not appropriate hosts for Uncinaria spp. Hookworm free-living third stage larvae, developed from eggs of California sea lions and northern fur seals, were recovered from sand. It seems that at this time, further search for hookworms in NESs would be nonproductive.

  11. A comparative analysis of preservation techniques for the optimal molecular detection of hookworm DNA in a human fecal specimen

    Science.gov (United States)

    Pilotte, Nils; Baumer, Ben; Grant, Jessica; Asbjornsdottir, Kristjana; Schaer, Fabian; Hu, Yan; Aroian, Raffi; Walson, Judd; Williams, Steven A.

    2018-01-01

    Background Proper collection and storage of fecal samples is necessary to guarantee the subsequent reliability of DNA-based soil-transmitted helminth diagnostic procedures. Previous research has examined various methods to preserve fecal samples for subsequent microscopic analysis or for subsequent determination of overall DNA yields obtained following DNA extraction. However, only limited research has focused on the preservation of soil-transmitted helminth DNA in stool samples stored at ambient temperature or maintained in a cold chain for extended periods of time. Methodology Quantitative real-time PCR was used in this study as a measure of the effectiveness of seven commercially available products to preserve hookworm DNA over time and at different temperatures. Results were compared against “no preservative” controls and the “gold standard” of rapidly freezing samples at -20°C. The preservation methods were compared at both 4°C and at simulated tropical ambient temperature (32°C) over a period of 60 days. Evaluation of the effectiveness of each preservative was based on quantitative real-time PCR detection of target hookworm DNA. Conclusions At 4°C there were no significant differences in DNA amplification efficiency (as measured by Cq values) regardless of the preservation method utilized over the 60-day period. At 32°C, preservation with FTA cards, potassium dichromate, and a silica bead two-step desiccation process proved most advantageous for minimizing Cq value increases, while RNA later, 95% ethanol and Paxgene also demonstrate some protective effect. These results suggest that fecal samples spiked with known concentrations of hookworm-derived egg material can remain at 4°C for 60 days in the absence of preservative, without significant degradation of the DNA target. Likewise, a variety of preservation methods can provide a measure of protection in the absence of a cold chain. As a result, other factors, such as preservative toxicity

  12. Prior mucosal exposure to heterologous cells alters the pathogenesis of cell-associated mucosal feline immunodeficiency virus challenge

    Directory of Open Access Journals (Sweden)

    Leavell Sarah

    2010-05-01

    Full Text Available Abstract Background Several lines of research suggest that exposure to cellular material can alter the susceptibility to infection by HIV-1. Because sexual contact often includes exposure to cellular material, we hypothesized that repeated mucosal exposure to heterologous cells would induce an immune response that would alter the susceptibility to mucosal infection. Using the feline immunodeficiency virus (FIV model of HIV-1 mucosal transmission, the cervicovaginal mucosa was exposed once weekly for 12 weeks to 5,000 heterologous cells or media (control and then cats were vaginally challenged with cell-associated or cell-free FIV. Results Exposure to heterologous cells decreased the percentage of lymphocytes in the mucosal and systemic lymph nodes (LN expressing L-selectin as well as the percentage of CD4+ CD25+ T cells. These shifts were associated with enhanced ex-vivo proliferative responses to heterologous cells. Following mucosal challenge with cell-associated, but not cell-free, FIV, proviral burden was reduced by 64% in cats previously exposed to heterologous cells as compared to media exposed controls. Conclusions The pathogenesis and/or the threshold for mucosal infection by infected cells (but not cell-free virus can be modulated by mucosal exposure to uninfected heterologous cells.

  13. Method for determining heterologous biosynthesis pathways

    KAUST Repository

    Gao, Xin; Kuwahara, Hiroyuki; Alazmi, Meshari Saud; Cui, Xuefeng

    2017-01-01

    suitable pathways for the endogenous metabolism of a host organism because the efficacy of heterologous biosynthesis is affected by competing endogenous pathways. The present invention is called MRE (Metabolic Route Explorer), and it was conceived

  14. Heterologous Protection against Asian Zika Virus Challenge in Rhesus Macaques.

    Directory of Open Access Journals (Sweden)

    Matthew T Aliota

    2016-12-01

    Full Text Available Zika virus (ZIKV; Flaviviridae, Flavivirus was declared a public health emergency of international concern by the World Health Organization (WHO in February 2016, because of the evidence linking infection with ZIKV to neurological complications, such as Guillain-Barre Syndrome in adults and congenital birth defects including microcephaly in the developing fetus. Because development of a ZIKV vaccine is a top research priority and because the genetic and antigenic variability of many RNA viruses limits the effectiveness of vaccines, assessing whether immunity elicited against one ZIKV strain is sufficient to confer broad protection against all ZIKV strains is critical. Recently, in vitro studies demonstrated that ZIKV likely circulates as a single serotype. Here, we demonstrate that immunity elicited by African lineage ZIKV protects rhesus macaques against subsequent infection with Asian lineage ZIKV.Using our recently developed rhesus macaque model of ZIKV infection, we report that the prototypical ZIKV strain MR766 productively infects macaques, and that immunity elicited by MR766 protects macaques against heterologous Asian ZIKV. Furthermore, using next generation deep sequencing, we found in vivo restoration of a putative N-linked glycosylation site upon replication in macaques that is absent in numerous MR766 strains that are widely being used by the research community. This reversion highlights the importance of carefully examining the sequence composition of all viral stocks as well as understanding how passage history may alter a virus from its original form.An effective ZIKV vaccine is needed to prevent infection-associated fetal abnormalities. Macaques whose immune responses were primed by infection with East African ZIKV were completely protected from detectable viremia when subsequently rechallenged with heterologous Asian ZIKV. Therefore, these data suggest that immunogen selection is unlikely to adversely affect the breadth of

  15. Expression, purification, and characterization of the Necator americanus aspartic protease-1 (Na-APR-1 (M74)) antigen, a component of the bivalent human hookworm vaccine.

    Science.gov (United States)

    Seid, Christopher A; Curti, Elena; Jones, R Mark; Hudspeth, Elissa; Rezende, Wanderson; Pollet, Jeroen; Center, Lori; Versteeg, Leroy; Pritchard, Sonya; Musiychuk, Konstantin; Yusibov, Vidadi; Hotez, Peter J; Bottazzi, Maria Elena

    2015-01-01

    Over 400 million people living in the world's poorest developing nations are infected with hookworms, mostly of the genus Necator americanus. A bivalent human hookworm vaccine composed of the Necator americanus Glutathione S-Transferase-1 (Na-GST-1) and the Necator americanus Aspartic Protease-1 (Na-APR-1 (M74)) is currently under development by the Sabin Vaccine Institute Product Development Partnership (Sabin PDP). Both monovalent vaccines are currently in Phase 1 trials. Both Na-GST-1 and Na-APR-1 antigens are expressed as recombinant proteins. While Na-GST-1 was found to express with high yields in Pichia pastoris, the level of expression of Na-APR-1 in this host was too low to be suitable for a manufacturing process. When the tobacco plant Nicotiana benthamiana was evaluated as an expression system, acceptable levels of solubility, yield, and stability were attained. Observed expression levels of Na-APR-1 (M74) using this system are ∼300 mg/kg. Here we describe the achievements and obstacles encountered during process development as well as characterization and stability of the purified Na-APR-1 (M74) protein and formulated vaccine. The expression, purification and analysis of purified Na-APR-1 (M74) protein obtained from representative 5 kg reproducibility runs performed to qualify the Na-APR-1 (M74) production process is also presented. This process has been successfully transferred to a pilot plant and a 50 kg scale manufacturing campaign under current Good Manufacturing Practice (cGMP) has been performed. The 50 kg run has provided a sufficient amount of protein to support the ongoing hookworm vaccine development program of the Sabin PDP.

  16. Adaptation in the innate immune system and heterologous innate immunity.

    Science.gov (United States)

    Martin, Stefan F

    2014-11-01

    The innate immune system recognizes deviation from homeostasis caused by infectious or non-infectious assaults. The threshold for its activation seems to be established by a calibration process that includes sensing of microbial molecular patterns from commensal bacteria and of endogenous signals. It is becoming increasingly clear that adaptive features, a hallmark of the adaptive immune system, can also be identified in the innate immune system. Such adaptations can result in the manifestation of a primed state of immune and tissue cells with a decreased activation threshold. This keeps the system poised to react quickly. Moreover, the fact that the innate immune system recognizes a wide variety of danger signals via pattern recognition receptors that often activate the same signaling pathways allows for heterologous innate immune stimulation. This implies that, for example, the innate immune response to an infection can be modified by co-infections or other innate stimuli. This "design feature" of the innate immune system has many implications for our understanding of individual susceptibility to diseases or responsiveness to therapies and vaccinations. In this article, adaptive features of the innate immune system as well as heterologous innate immunity and their implications are discussed.

  17. Albendazole and ivermectin for the control of soil-transmitted helminths in an area with high prevalence of Strongyloides stercoralis and hookworm in northwestern Argentina: A community-based pragmatic study.

    Directory of Open Access Journals (Sweden)

    Adriana Echazú

    2017-10-01

    Full Text Available Recommendations for soil-transmitted helminth (STH control give a key role to deworming of school and pre-school age children with albendazole or mebendazole; which might be insufficient to achieve adequate control, particularly against Strongyloides stercoralis. The impact of preventive chemotherapy (PC against STH morbidity is still incompletely understood. The aim of this study was to assess the effectiveness of a community-based program with albendazole and ivermectin in a high transmission setting for S. stercoralis and hookworm.Community-based pragmatic trial conducted in Tartagal, Argentina; from 2012 to 2015. Six communities (5070 people were enrolled for community-based PC with albendazole and ivermectin. Two communities (2721 people were re-treated for second and third rounds. STH prevalence, anemia and malnutrition were explored through consecutive surveys. Anthropometric assessment of children, stool analysis, complete blood count and NIE-ELISA serology for S. stercoralis were performed.STH infection was associated with anemia and stunting in the baseline survey that included all communities and showed a STH prevalence of 47.6% (almost exclusively hookworm and S. stercoralis. Among communities with multiple interventions, STH prevalence decreased from 62% to 23% (p<0.001 after the first PC; anemia also diminished from 52% to 12% (p<0.001. After two interventions S. stercoralis seroprevalence declined, from 51% to 14% (p<0.001 and stunting prevalence decreased, from 19% to 12% (p = 0.009.Hookworm' infections are associated with anemia in the general population and nutritional impairment in children. S. stercoralis is also associated with anemia. Community-based deworming with albendazole and ivermectin is effective for the reduction of STH prevalence and morbidity in communities with high prevalence of hookworm and S. stercoralis.

  18. Overcoming tumor resistance by heterologous adeno-poxvirus combination therapy

    Directory of Open Access Journals (Sweden)

    Markus Vähä-Koskela

    2014-01-01

    Full Text Available Successful cancer control relies on overcoming resistance to cell death and on activation of host antitumor immunity. Oncolytic viruses are particularly attractive in this regard, as they lyse infected tumor cells and trigger robust immune responses during the infection. However, repeated injections of the same virus promote antiviral rather than antitumor immunity and tumors may mount innate antiviral defenses to restrict oncolytic virus replication. In this article, we have explored if alternating the therapy virus could circumvent these problems. We demonstrate in two virus-resistant animal models a substantial delay in antiviral immune- and innate cellular response induction by alternating injections of two immunologically distinct oncolytic viruses, adenovirus, and vaccinia virus. Our results are in support of clinical development of heterologous adeno-/vaccinia virus therapy of cancer.

  19. New tools for NTD vaccines: A case study of quality control assays for product development of the human hookworm vaccine Na-APR-1M74.

    Science.gov (United States)

    Pearson, Mark S; Jariwala, Amar R; Abbenante, Giovanni; Plieskatt, Jordan; Wilson, David; Bottazzi, Maria Elena; Hotez, Peter J; Keegan, Brian; Bethony, Jeffrey M; Loukas, Alex

    2015-01-01

    Na-APR-1(M74) is an aspartic protease that is rendered enzymatically inactive by site-directed mutagenesis and is a candidate antigen component in the Human Hookworm Vaccine. The mutant protease exerts vaccine efficacy by inducing antibodies that neutralize the enzymatic activity of wild type enzyme (Na-APR-1wt) in the gut of the hookworm, thereby depriving the worm of its ability to digest its blood meal. Previously, canines immunized with Na-APR-1(M74) and challenged with Ancylostoma caninum were partially protected against hookworm challenge infection, especially from the loss in hemoglobin observed in control canines and canine immunoglobulin (Ig) G raised against Na-APR-1 was shown to inhibit the enzymatic activity of Na-APR-1 wt in vitro, thereby providing proof of concept of Na-APR-1(M74) as a vaccine antigen. The mutated version, Na-APR-1(M74), was then expressed at the cGMP level using a Nicotiana benthamiana expression system (Fraunhofer, CMB, Delaware, MD), formulated with Alhydrogel®, and used to immunize mice in a dose-ranging study to explore the enzyme-neutralizing capacity of the resulting anti- Na-APR-1(M74) IgG. As little as 0.99 μg of recombinant Na-APR-1(M74) could induce anti Na-APR-1(M74) IgG in mice that were capable of inhibiting Na-APR-1w t-mediated digestion of a peptide substrate by 89%. In the absence of enzymatic activity of Na-APR-1(M74) as a surrogate marker of protein functionality, we developed an assay based on the binding of a quenched fluorescence-labeled inhibitor of aspartic proteases, BODIPY-FL pepstatin A (BDP). Binding of BDP in the active site of Na-APR-1 wt was demonstrated by inhibition of enzymatic activity, and competitive binding with unlabelled pepstatin A. BDP also bound to Na-APR-1(M74) which was assessed by fluorescence polarization, but with an ∼ 50-fold reduction in the dissociation constant. Taken together, these assays comprise a "toolbox" that could be useful for the analyses of Na-APR-1(M74) as it

  20. Uptake and Persistence of Homologous and Heterologous Zooxanthellae in the Temperate Sea Anemone Cereus pedunculatus (Pennant).

    Science.gov (United States)

    Davy, S K; Lucas, I A N; Turner, J R

    1997-04-01

    The uptake and persistence of symbiotic dinoflagellates (zooxanthellae) were measured in the temperate sea anemone Cereus pedunculatus (Pennant). Aposymbiotic specimens of C. pedunculatus were inoculated with zooxanthellae freshly isolated from a range of temperate and subtropical Anthozoa. Each inoculate consisted of zooxanthellae from a single host species and was either homologous (zooxanthellae from a host of the same species as the one being inoculated) or heterologous (from a host of a different species than the one being inoculated). The densities of zooxanthellae in host tissues were determined at regular intervals. C. pedunculatus took up homologous and heterologous zooxanthellae to similar degrees, except for zooxanthellae from the temperate Anthopleura ballii, which were taken up to a lesser extent. The densities of all zooxanthellae declined between 4 hours and 4 days after uptake, indicating that zooxanthellae were expelled, digested, or both during this period. The densities of all zooxanthellae increased between 2 and 8 weeks after inoculation, indicating zooxanthella growth. Over the entire 8-week period after uptake, densities of homologous zooxanthellae were always greater than those of heterologous zooxanthellae. Between 8 and 36 weeks after infection, densities of homologous zooxanthellae declined markedly and densities of some heterologous zooxanthellae increased further, resulting in homologous and heterologous zooxanthella densities being the same at 36 weeks. These densities were the same as those in naturally infected C. pedunculatus of similar size. The results suggest that zooxanthellae from a range of host species and environments can establish symbioses with C. pedunculatus and that, over long periods under laboratory conditions, heterologous zooxanthellae may populate C. pedunculatus to the same extent as homologous zooxanthellae.

  1. Two potential hookworm DAF-16 target genes, SNR-3 and LPP-1: gene structure, expression profile, and implications of a cis-regulatory element in the regulation of gene expression.

    Science.gov (United States)

    Gao, Xin; Goggin, Kevin; Dowling, Camille; Qian, Jason; Hawdon, John M

    2015-01-08

    Hookworms infect nearly 700 million people, causing anemia and developmental stunting in heavy infections. Little is known about the genomic structure or gene regulation in hookworms, although recent publication of draft genome assemblies has allowed the first investigations of these topics to be undertaken. The transcription factor DAF-16 mediates multiple developmental pathways in the free living nematode Caenorhabditis elegans, and is involved in the recovery from the developmentally arrested L3 in hookworms. Identification of downstream targets of DAF-16 will provide a better understanding of the molecular mechanism of hookworm infection. Genomic Fragment 2.23 containing a DAF-16 binding element (DBE) was used to identify overlapping complementary expressed sequence tags (ESTs). These sequences were used to search a draft assembly of the Ancylostoma caninum genome, and identified two neighboring genes, snr-3 and lpp-1, in a tail-to-tail orientation. Expression patterns of both genes during parasitic development were determined by qRT-PCR. DAF-16 dependent cis-regulatory activity of fragment 2.23 was investigated using an in vitro reporter system. The snr-3 gene spans approximately 5.6 kb in the genome and contains 3 exons and 2 introns, and contains the DBE in its 3' untranslated region. Downstream from snr-3 in a tail-to-tail arrangement is the gene lpp-1. The lpp-1 gene spans more than 6 kb and contains 10 exons and 9 introns. The A. caninum genome contains 2 apparent splice variants, but there are 7 splice variants in the A. ceylanicum genome. While the gene order is similar, the gene structures of the hookworm genes differ from their C. elegans orthologs. Both genes show peak expression in the late L4 stage. Using a cell culture based expression system, fragment 2.23 was found to have both DAF-16-dependent promoter and enhancer activity that required an intact DBE. Two putative DAF-16 targets were identified by genome wide screening for DAF-16 binding

  2. Heterologous Protein Expression by Lactococcus lactis

    NARCIS (Netherlands)

    Villatoro-Hernández, J.; Kuipers, O.P.; Saucedo-Cárdenas, O.; Montes-de-Oca-Luna, R.

    2012-01-01

    This chapter describes the use of Lactococcus lactis as a safe and efficient cell factory to produce heterologous proteins of medical interest. The relevance of the use of this lactic acid bacterium (LAB) is that it is a noncolonizing, nonpathogenic microorganism that can be delivered in vivo at a

  3. Albendazole and ivermectin for the control of soil-transmitted helminths in an area with high prevalence of Strongyloides stercoralis and hookworm in northwestern Argentina: A community-based pragmatic study.

    Science.gov (United States)

    Echazú, Adriana; Juarez, Marisa; Vargas, Paola A; Cajal, Silvana P; Cimino, Ruben O; Heredia, Viviana; Caropresi, Silvia; Paredes, Gladys; Arias, Luis M; Abril, Marcelo; Gold, Silvia; Lammie, Patrick; Krolewiecki, Alejandro J

    2017-10-01

    Recommendations for soil-transmitted helminth (STH) control give a key role to deworming of school and pre-school age children with albendazole or mebendazole; which might be insufficient to achieve adequate control, particularly against Strongyloides stercoralis. The impact of preventive chemotherapy (PC) against STH morbidity is still incompletely understood. The aim of this study was to assess the effectiveness of a community-based program with albendazole and ivermectin in a high transmission setting for S. stercoralis and hookworm. Community-based pragmatic trial conducted in Tartagal, Argentina; from 2012 to 2015. Six communities (5070 people) were enrolled for community-based PC with albendazole and ivermectin. Two communities (2721 people) were re-treated for second and third rounds. STH prevalence, anemia and malnutrition were explored through consecutive surveys. Anthropometric assessment of children, stool analysis, complete blood count and NIE-ELISA serology for S. stercoralis were performed. STH infection was associated with anemia and stunting in the baseline survey that included all communities and showed a STH prevalence of 47.6% (almost exclusively hookworm and S. stercoralis). Among communities with multiple interventions, STH prevalence decreased from 62% to 23% (palbendazole and ivermectin is effective for the reduction of STH prevalence and morbidity in communities with high prevalence of hookworm and S. stercoralis.

  4. Heterologous Protection against Malaria after Immunization with Plasmodium falciparum Sporozoites.

    Directory of Open Access Journals (Sweden)

    Remko Schats

    Full Text Available Sterile protection in >90% of volunteers against homologous Plasmodium falciparum infection has been achieved only using the controlled human malaria infection (CHMI model. This efficient model involves whole parasite immunizations under chloroquine prophylaxis (CPS-immunization, requiring only 30-45 mosquitoes bites infected with P. falciparum-sporozoites. Given the large diversity of P. falciparum parasites, it is essential to assess protection against heterologous parasite strains.In an open-label follow-up study, 16 volunteers previously CPS-immunized and challenged with P. falciparum NF54 (West-Africa in a dose de-escalation and challenge trial were re-challenged with clone NF135.C10 (Cambodia at 14 months after the last immunization (NCT01660854.Two out of thirteen NF54 protected volunteers previously fully protected against NF54 were also fully protected against NF135.C10, while 11/13 showed a delayed patency (median prepatent period of 10.5 days (range 9.0-15.5 versus 8.5 days in 5 malaria-naïve controls (p = 0.0005. Analysis of patency by qPCR indicated a 91 to >99% estimated reduction of liver parasite load in 7/11 partially protected subjects. Three volunteers previously not protected against NF54, were also not protected against NF135.C10.This study shows that CPS-immunization can induce heterologous protection for a period of more than one year, which is a further impetus for clinical development of whole parasite vaccines.Clinicaltrials.gov NCT01660854.

  5. Model for product development of vaccines against neglected tropical diseases: a vaccine against human hookworm.

    Science.gov (United States)

    Bottazzi, Maria Elena; Brown, Ami Shah

    2008-12-01

    This article provides an overview of the advances in product development and technology transfer of the vaccine against human hookworm, with particular emphasis on the lessons learned and the challenges of developing a vaccine in the nonprofit sector. The comprehensive approach to vaccine development established by the Human Hookworm Vaccine Initiative (HHVI) identifies key operational and technical aspects that are essential for a successful partnership with a developing country vaccine manufacturer. This article also highlights the importance of a global access roadmap to guide the vaccine development program. The advancement of new products for the control of neglected tropical diseases portends great challenges for global access, including aspects related to vaccine design, product development and manufacture, vaccine introduction and distribution, financing, knowledge dissemination and intellectual property management. With only three vaccines for neglected tropical diseases in clinical trials - hookworm, leishmaniasis and schistosomiasis - we are at the nascent stages of developing vaccines for neglected populations. Product development public-private partnerships, such as the HHVI, continue to show great promise on this front and will eventually provide significant control tools for achieving millennium development goals related to poverty reduction, as well as child and maternal health.

  6. Heterologous Prime-Boost HIV-1 Vaccination Regimens in Pre-Clinical and Clinical Trials

    Directory of Open Access Journals (Sweden)

    Julia L. Hurwitz

    2010-02-01

    Full Text Available Currently, there are more than 30 million people infected with HIV-1 and thousands more are infected each day. Vaccination is the single most effective mechanism for prevention of viral disease, and after more than 25 years of research, one vaccine has shown somewhat encouraging results in an advanced clinical efficacy trial. A modified intent-to-treat analysis of trial results showed that infection was approximately 30% lower in the vaccine group compared to the placebo group. The vaccine was administered using a heterologous prime-boost regimen in which both target antigens and delivery vehicles were changed during the course of inoculations. Here we examine the complexity of heterologous prime-boost immunizations. We show that the use of different delivery vehicles in prime and boost inoculations can help to avert the inhibitory effects caused by vector-specific immune responses. We also show that the introduction of new antigens into boost inoculations can be advantageous, demonstrating that the effect of ‘original antigenic sin’ is not absolute. Pre-clinical and clinical studies are reviewed, including our own work with a three-vector vaccination regimen using recombinant DNA, virus (Sendai virus or vaccinia virus and protein. Promising preliminary results suggest that the heterologous prime-boost strategy may possibly provide a foundation for the future prevention of HIV-1 infections in humans.

  7. Effectiveness of Albendazole for Hookworm Varies Widely by Community and Correlates with Nutritional Factors: A Cross-Sectional Study of School-Age Children in Ghana.

    Science.gov (United States)

    Humphries, Debbie; Nguyen, Sara; Kumar, Sunny; Quagraine, Josephine E; Otchere, Joseph; Harrison, Lisa M; Wilson, Michael; Cappello, Michael

    2017-02-08

    Mass drug administration (MDA) targeting school-age children is recommended by the World Health Organization for the global control of soil-transmitted helminth (STH) infections. Although considered safe and cost-effective to deliver, benzimidazole anthelminthics are variably effective against the three most common STHs, and widespread use has raised concern about the potential for emerging resistance. To identify factors mediating response to albendazole, we conducted a cross-sectional study of hookworm infection in the Kintampo North Municipality of Ghana in 2011. Among 140 school-age children residing in five contiguous communities, the hookworm prevalence was 59% (82/140). The overall cure rate following administration of single-dose albendazole (400 mg) was 35% (27/76), with a community-wide fecal egg reduction rate (ERR) of 61% (95% confidence interval: 51.8-71.1). Significant disparities were observed in albendazole effectiveness by community, with a cure rate as low as 0% ( N = 24) in Jato Akuraa and ERRs ranging from 53% to 95% across the five study sites. Individual host factors associated with response to deworming treatment included time since last meal, pretreatment blood hemoglobin level, and mid-upper arm circumference. These data demonstrate significant community-level variation in the effectiveness of albendazole, even among populations living in close proximity. Identification of host factors that influence response to albendazole, most notably the timing of drug administration and nutritional factors, creates an opportunity to enhance the effectiveness of deworming through targeted interventions. These findings also demonstrate the importance of measuring anthelminthic response as part of the monitoring and evaluation of community-based deworming programs. © The American Society of Tropical Medicine and Hygiene.

  8. Fusarium pathogenesis investigated using Galleria mellonella as a heterologous host

    Science.gov (United States)

    Coleman, Jeffrey J.; Muhammed, Maged; Kasperkovitz, Pia V.; Vyas, Jatin M.; Mylonakis, Eleftherios

    2011-01-01

    Members of the fungal genus Fusarium are capable of manifesting in a multitude of clinical infections, most commonly in immunocompromised patients. In order to better understand the interaction between the fungus and host, we have developed the larvae of the greater wax moth, Galleria mellonella, as a heterologous host for fusaria. When conidia are injected into the hemocoel of this Lepidopteran system, both clinical and environmental isolates of the fungus are able to kill the larvae at 37°C, although killing occurs more rapidly when incubated at 30°C. This killing was dependent on several other factors besides temperature, including the Fusarium strain, the number of conidia injected, and the conidia morphology, where macroconidia are more virulent than their microconidia counterpart. There was a correlation in the killing rate of Fusarium spp. when evaluated in G. mellonella and a murine model. In vivo studies indicated G. mellonella hemocytes were capable of initially phagocytosing both conidial morphologies. The G. mellonella system was also used to evaluate antifungal agents, and amphotericin B was able to confer a significant increase in survival to Fusarium infected-larvae. The G. mellonella-Fusarium pathogenicity system revealed that virulence of Fusarium spp. is similar, regardless of the origin of the isolate, and that mammalian endothermy is a major deterrent for Fusarium infection and therefore provides a suitable alternative to mammalian models to investigate the interaction between the host and this increasingly important fungal pathogen. PMID:22115447

  9. The structure of hookworm platelet inhibitor (HPI), a CAP superfamily member from Ancylostoma caninum.

    Science.gov (United States)

    Ma, Dongying; Francischetti, Ivo M B; Ribeiro, Jose M C; Andersen, John F

    2015-06-01

    Secreted protein components of hookworm species include a number of representatives of the cysteine-rich/antigen 5/pathogenesis-related 1 (CAP) protein family known as Ancylostoma-secreted proteins (ASPs). Some of these have been considered as candidate antigens for the development of vaccines against hookworms. The functions of most CAP superfamily members are poorly understood, but one form, the hookworm platelet inhibitor (HPI), has been isolated as a putative antagonist of the platelet integrins αIIbβ3 and α2β1. Here, the crystal structure of HPI is described and its structural features are examined in relation to its possible function. The HPI structure is similar to those of other ASPs and shows incomplete conservation of the sequence motifs CAP1 and CAP2 that are considered to be diagnostic of CAP superfamily members. The asymmetric unit of the HPI crystal contains a dimer with an extensive interaction interface, but chromatographic measurements indicate that it is primarily monomeric in solution. In the dimeric structure, the putative active-site cleft areas from both monomers are united into a single negatively charged depression. A potential Lys-Gly-Asp disintegrin-like motif was identified in the sequence of HPI, but is not positioned at the apex of a tight turn, making it unlikely that it interacts with the integrin. Recombinant HPI produced in Escherichia coli was found not to inhibit the adhesion of human platelets to collagen or fibrinogen, despite having a native structure as shown by X-ray diffraction. This result corroborates previous analyses of recombinant HPI and suggests that it might require post-translational modification or have a different biological function.

  10. Albendazole and ivermectin for the control of soil-transmitted helminths in an area with high prevalence of Strongyloides stercoralis and hookworm in northwestern Argentina: A community-based pragmatic study

    Science.gov (United States)

    Juarez, Marisa; Vargas, Paola A.; Cajal, Silvana P.; Cimino, Ruben O.; Heredia, Viviana; Caropresi, Silvia; Paredes, Gladys; Arias, Luis M.; Abril, Marcelo; Gold, Silvia; Lammie, Patrick; Krolewiecki, Alejandro J.

    2017-01-01

    Background Recommendations for soil-transmitted helminth (STH) control give a key role to deworming of school and pre-school age children with albendazole or mebendazole; which might be insufficient to achieve adequate control, particularly against Strongyloides stercoralis. The impact of preventive chemotherapy (PC) against STH morbidity is still incompletely understood. The aim of this study was to assess the effectiveness of a community-based program with albendazole and ivermectin in a high transmission setting for S. stercoralis and hookworm. Methodology Community-based pragmatic trial conducted in Tartagal, Argentina; from 2012 to 2015. Six communities (5070 people) were enrolled for community-based PC with albendazole and ivermectin. Two communities (2721 people) were re-treated for second and third rounds. STH prevalence, anemia and malnutrition were explored through consecutive surveys. Anthropometric assessment of children, stool analysis, complete blood count and NIE-ELISA serology for S. stercoralis were performed. Principal findings STH infection was associated with anemia and stunting in the baseline survey that included all communities and showed a STH prevalence of 47.6% (almost exclusively hookworm and S. stercoralis). Among communities with multiple interventions, STH prevalence decreased from 62% to 23% (p<0.001) after the first PC; anemia also diminished from 52% to 12% (p<0.001). After two interventions S. stercoralis seroprevalence declined, from 51% to 14% (p<0.001) and stunting prevalence decreased, from 19% to 12% (p = 0.009). Conclusions Hookworm’ infections are associated with anemia in the general population and nutritional impairment in children. S. stercoralis is also associated with anemia. Community-based deworming with albendazole and ivermectin is effective for the reduction of STH prevalence and morbidity in communities with high prevalence of hookworm and S. stercoralis. PMID:28991899

  11. Long-Lasting Effects of BCG Vaccination on Both Heterologous Th1/Th17 Responses and Innate Trained Immunity

    DEFF Research Database (Denmark)

    Kleinnijenhuis, Johanneke; Quintin, Jessica; Preijers, Frank

    2013-01-01

    '. In the present study we assessed whether BCG was able to induce long-lasting effects on both trained immunity and heterologous T helper 1 (Th1) and Th17 immune responses 1 year after vaccination. The production of TNFα and IL-1β to mycobacteria or unrelated pathogens was higher after 2 weeks and 3 months...... in proinflammatory cytokine production after stimulation with the TLR4 ligand lipopolysaccharide. The heterologous production of Th1 (IFN-γ) and Th17 (IL-17 and IL-22) immune responses to nonmycobacterial stimulation remained strongly elevated even 1 year after BCG vaccination. In conclusion, BCG induces sustained...... changes in the immune system associated with a nonspecific response to infections both at the level of innate trained immunity and at the level of heterologous Th1/Th17 responses. © 2013 S. Karger AG, Basel....

  12. Relationship between intensity of soil-transmitted helminth infections and anemia during pregnancy.

    Science.gov (United States)

    Larocque, Renee; Casapia, Martin; Gotuzzo, Eduardo; Gyorkos, Theresa W

    2005-10-01

    A direct relationship exists between the intensity of hookworm infection and blood loss. Other parasites may also contribute to blood loss. Our objective was to assess the relationship between the intensity of soil-transmitted helminth infections and anemia in pregnant women in a highly endemic area of Peru. Recruitment occurred between April and November 2003. Overall, 47.31% of 1,042 women had anemia (hemoglobin anemia. However, those infected with moderate and heavy intensities of hookworm infection (OR = 1.84; 95% CI: 1.06, 3.17) and those with moderate and heavy intensities of both hookworm and Trichuris infections (OR = 2.13; 95% CI: 1.10, 4.13) were more likely to suffer from anemia than women having no or light intensities. These results support routine anthelminthic treatment within prenatal care programs in highly endemic areas.

  13. Heterologous expression in Tritrichomonas foetus of functional Trichomonas vaginalis AP65 adhesin

    Directory of Open Access Journals (Sweden)

    Alderete JF

    2005-03-01

    Full Text Available Abstract Background Trichomonosis, caused by Trichomonas vaginalis, is the number one, nonviral sexually transmitted infection that has adverse consequences for the health of women and children. The interaction of T. vaginalis with vaginal epithelial cells (VECs, a step preparatory to infection, is mediated in part by the prominent surface protein AP65. The bovine trichomonad, Tritrichomonas foetus, adheres poorly to human VECs. Thus, we established a transfection system for heterologous expression of the T. vaginalis AP65 in T. foetus, as an alternative approach to confirm adhesin function for this virulence factor. Results In this study, we show stable transfection and expression of the T. vaginalis ap65 gene in T. foetus from an episomal pBS-ap65-neo plasmid. Expression of the gene and protein was confirmed by RT-PCR and immunoblots, respectively. AP65 in transformed T. foetus bound to host cells. Specific mAbs revealed episomally-expressed AP65 targeted to the parasite surface and hydrogenosome organelles. Importantly, surface-expression of AP65 in T. foetus paralleled increased levels of adherence of transfected bovine trichomonads to human VECs. Conclusion The T. vaginalis AP65 adhesin was stably expressed in T. foetus, and the data obtained using this heterologous system strongly supports the role of AP65 as a prominent adhesin for T. vaginalis. In addition, the heterologous expression in T. foetus of a T. vaginalis gene offers an important, new approach for confirming and characterizing virulence factors.

  14. The bandit, a new DNA transposon from a hookworm-possible horizontal genetic transfer between host and parasite.

    Directory of Open Access Journals (Sweden)

    Thewarach Laha

    2007-09-01

    Full Text Available An enhanced understanding of the hookworm genome and its resident mobile genetic elements should facilitate understanding of the genome evolution, genome organization, possibly host-parasite co-evolution and horizontal gene transfer, and from a practical perspective, development of transposon-based transgenesis for hookworms and other parasitic nematodes.A novel mariner-like element (MLE was characterized from the genome of the dog hookworm, Ancylostoma caninum, and termed bandit. The consensus sequence of the bandit transposon was 1,285 base pairs (bp in length. The new transposon was flanked by perfect terminal inverted repeats of 32 nucleotides in length with a common target site duplication TA, and it encoded an open reading frame (ORF of 342 deduced amino acid residues. Phylogenetic comparisons confirmed that the ORF encoded a mariner-like transposase, which included conserved catalytic domains, and that the bandit transposon belonged to the cecropia subfamily of MLEs. The phylogenetic analysis also indicated that the Hsmar1 transposon from humans was the closest known relative of bandit, and that bandit and Hsmar1 constituted a clade discrete from the Tc1 subfamily of MLEs from the nematode Caenorhabditis elegans. Moreover, homology models based on the crystal structure of Mos1 from Drosophila mauritiana revealed closer identity in active site residues of the catalytic domain including Ser281, Lys289 and Asp293 between bandit and Hsmar1 than between Mos1 and either bandit or Hsmar1. The entire bandit ORF was amplified from genomic DNA and a fragment of the bandit ORF was amplified from RNA, indicating that this transposon is actively transcribed in hookworms.A mariner-like transposon termed bandit has colonized the genome of the hookworm A. caninum. Although MLEs exhibit a broad host range, and are identified in other nematodes, the closest phylogenetic relative of bandit is the Hsmar1 element of humans. This surprising finding suggests

  15. Heterologous Expression of the Oxytetracycline Biosynthetic Pathway in Myxococcus xanthus▿

    Science.gov (United States)

    Stevens, D. Cole; Henry, Michael R.; Murphy, Kimberly A.; Boddy, Christopher N.

    2010-01-01

    New natural products for drug discovery may be accessed by heterologous expression of bacterial biosynthetic pathways in metagenomic DNA libraries. However, a “universal” host is needed for this experiment. Herein, we show that Myxococcus xanthus is a potential “universal” host for heterologous expression of polyketide biosynthetic gene clusters. PMID:20208031

  16. Heterologous expression of cellobiohydrolases in filamentous fungi

    DEFF Research Database (Denmark)

    Zoglowek, Marta; Lübeck, Peter S.; Ahring, Birgitte K.

    2015-01-01

    Cellobiohydrolases are among the most important enzymes functioning in the hydrolysis of crystalline cellulose, significantly contributing to the efficient biorefining of recalcitrant lignocellulosic biomass into biofuels and bio-based products. Filamentous fungi are recognized as both well...... into valuable products. However, due to low cellobiohydrolase activities, certain fungi might be deficient with regard to enzymes of value for cellulose conversion, and improving cellobiohydrolase expression in filamentous fungi has proven to be challenging. In this review, we examine the effects of altering...... promoters, signal peptides, culture conditions and host post-translational modifications. For heterologous cellobiohydrolase production in filamentous fungi to become an industrially feasible process, the construction of site-integrating plasmids, development of protease-deficient strains and glycosylation...

  17. Heterologous gene expression in filamentous fungi.

    Science.gov (United States)

    Su, Xiaoyun; Schmitz, George; Zhang, Meiling; Mackie, Roderick I; Cann, Isaac K O

    2012-01-01

    Filamentous fungi are critical to production of many commercial enzymes and organic compounds. Fungal-based systems have several advantages over bacterial-based systems for protein production because high-level secretion of enzymes is a common trait of their decomposer lifestyle. Furthermore, in the large-scale production of recombinant proteins of eukaryotic origin, the filamentous fungi become the vehicle of choice due to critical processes shared in gene expression with other eukaryotic organisms. The complexity and relative dearth of understanding of the physiology of filamentous fungi, compared to bacteria, have hindered rapid development of these organisms as highly efficient factories for the production of heterologous proteins. In this review, we highlight several of the known benefits and challenges in using filamentous fungi (particularly Aspergillus spp., Trichoderma reesei, and Neurospora crassa) for the production of proteins, especially heterologous, nonfungal enzymes. We review various techniques commonly employed in recombinant protein production in the filamentous fungi, including transformation methods, selection of gene regulatory elements such as promoters, protein secretion factors such as the signal peptide, and optimization of coding sequence. We provide insights into current models of host genomic defenses such as repeat-induced point mutation and quelling. Furthermore, we examine the regulatory effects of transcript sequences, including introns and untranslated regions, pre-mRNA (messenger RNA) processing, transcript transport, and mRNA stability. We anticipate that this review will become a resource for researchers who aim at advancing the use of these fascinating organisms as protein production factories, for both academic and industrial purposes, and also for scientists with general interest in the biology of the filamentous fungi. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Ancylostoma ailuropodae sp. n. (Nematoda: Ancylostomatidae), a new hookworm parasite isolated from wild giant pandas in Southwest China

    Science.gov (United States)

    Hookworms belonging to the genus Ancylostoma cause ancylostomiasis, a disease of considerable concern in humans and domestic and wild animals. Molecular and epidemiological data support evidence for the zoonotic potential among species of Ancylostoma where transmission to humans is facilitated by ra...

  19. Molecular evidence of shared hookworm Ancylostoma tubaeforme haplotypes between the critically endangered Iberian lynx and sympatric domestic cats

    Czech Academy of Sciences Publication Activity Database

    Millán, J.; Blasco-Costa, Maria Isabel

    2012-01-01

    Roč. 186, 3-4 (2012), s. 518-522 ISSN 0304-4017 Institutional support: RVO:60077344 Keywords : Ancylostomiasis * Hookworm * Reservoir * Spain Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.381, year: 2012 http://www.sciencedirect.com/science/article/pii/S030440171100759X#

  20. Mapping Historic Hookworm Disease Prevalence in the Southern Us, Comparing Percent Prevalence with Percent Soil Drainage Type Using GIS

    Directory of Open Access Journals (Sweden)

    Alice L. Anderson

    2011-01-01

    Full Text Available Mapping of Historic US Hookworm prevalence data from the Rockefeller Sanitary Commission (early 1900s using current GIS (Geographic Information System software (county shape files illustrates the extremely high prevalence of hookworm disease (Uncariasis in the Southeastern US at the time. Some counties in 7 states recorded 50% to 100% of the population with positive screens for hookworm in a monumental surveillance and treatment campaign. Narrative descriptions mentioned higher prevalence in “sand districts” vs. “clay districts”. In order to validate this description for historic data, further GIS databases (STATSGO were used to classify and quantify the % acreage in Eastern North Carolina falling into moderately- to well-drained soil types. These were then mapped and compared with the historic prevalence data. Most severely infested counties had at least 50% moderately to well-drained soil. Further analysis on soil data for other states with “coastal plains” could provide more background information on Environmental conditions for hookworm prevalence and distribution in US history. “Since history has no properly scientific value, its only purpose is educative. And if historians neglect to educate the public, if they fail to interest it intelligently in the past, then all their historical learning is valueless except in so far as it educates themselves”. Trevelyan, (1922.

  1. Molecular systematics of pinniped hookworms (Nematoda: Uncinaria): species delimitation, host associations and host-induced morphometric variation.

    Science.gov (United States)

    Nadler, Steven A; Lyons, Eugene T; Pagan, Christopher; Hyman, Derek; Lewis, Edwin E; Beckmen, Kimberlee; Bell, Cameron M; Castinel, Aurelie; Delong, Robert L; Duignan, Padraig J; Farinpour, Cher; Huntington, Kathy Burek; Kuiken, Thijs; Morgades, Diana; Naem, Soraya; Norman, Richard; Parker, Corwin; Ramos, Paul; Spraker, Terry R; Berón-Vera, Bárbara

    2013-12-01

    Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the

  2. The mitochondrial genomes of Ancylostoma caninum and Bunostomum phlebotomum – two hookworms of animal health and zoonotic importance

    Directory of Open Access Journals (Sweden)

    Littlewood D Timothy J

    2009-02-01

    Full Text Available Abstract Background Hookworms are blood-feeding nematodes that parasitize the small intestines of many mammals, including humans and cattle. These nematodes are of major socioeconomic importance and cause disease, mainly as a consequence of anaemia (particularly in children or young animals, resulting in impaired development and sometimes deaths. Studying genetic variability within and among hookworm populations is central to addressing epidemiological and ecological questions, thus assisting in the control of hookworm disease. Mitochondrial (mt genes are known to provide useful population markers for hookworms, but mt genome sequence data are scant. Results The present study characterizes the complete mt genomes of two species of hookworm, Ancylostoma caninum (from dogs and Bunostomum phlebotomum (from cattle, each sequenced (by 454 technology or primer-walking, following long-PCR amplification from genomic DNA (~20–40 ng isolated from individual adult worms. These mt genomes were 13717 bp and 13790 bp in size, respectively, and each contained 12 protein coding, 22 transfer RNA and 2 ribosomal RNA genes, typical for other secernentean nematodes. In addition, phylogenetic analysis (by Bayesian inference and maximum likelihood of concatenated mt protein sequence data sets for 12 nematodes (including Ancylostoma caninum and Bunostomum phlebotomum, representing the Ascaridida, Spirurida and Strongylida, was conducted. The analysis yielded maximum statistical support for the formation of monophyletic clades for each recognized nematode order assessed, except for the Rhabditida. Conclusion The mt genomes characterized herein represent a rich source of population genetic markers for epidemiological and ecological studies. The strong statistical support for the construction of phylogenetic clades and consistency between the two different tree-building methods employed indicate the value of using whole mt genome data sets for systematic studies of

  3. CD4 and CD8 T cell responses to the M. tuberculosis Ag85B-TB10.4 promoted by adjuvanted subunit, adenovector or heterologous prime boost vaccination

    DEFF Research Database (Denmark)

    Elvang, Tara; Christensen, Jan P; Billeskov, Rolf

    2009-01-01

    recruited to the site of infection, at the onset of infection. However, compared to CD8 T cells, CD4 T cells showed more extensive recruitment and were the main T cell subset proliferating at the site of infection. CONCLUSIONS/SIGNIFICANCE: Heterologous prime boost based on H4, produced an additive effect...

  4. Three new shuttle vectors for heterologous expression in Zymomonas mobilis

    Directory of Open Access Journals (Sweden)

    Qinghua Cao

    2016-01-01

    Conclusions: These results indicated that these expression vectors are useful tools for gene expression in Z. mobilis and this could provide a solid foundation for further studies of heterologous gene expression in Z. mobilis.

  5. Adaption of Saccharomyces cerevisiae expressing a heterologous protein

    DEFF Research Database (Denmark)

    Krogh, Astrid Mørkeberg; Beck, Vibe; Højlund Christensen, Lars

    2008-01-01

    Production of the heterologous protein, bovine aprotinin, in Saccharomyces cerevisiae was shown to affect the metabolism of the host cell to various extent depending on the strain genotype. Strains with different genotypes, industrial and laboroatory, respectively, were investigated. The maximal...

  6. Heterologous prime-boost vaccinations for poverty-related diseases: advantages and future prospects.

    Science.gov (United States)

    Radosević, Katarina; Rodriguez, Ariane; Lemckert, Angelique; Goudsmit, Jaap

    2009-05-01

    Classical vaccination approaches, based on a single vaccine administered in a homologous prime-boost schedule and optimized to induce primarily neutralizing antibodies, are unlikely to be sufficiently efficacious to prevent TB, malaria or HIV infections. Novel vaccines, capable of inducing a more powerful immune response, in particular T-cell immunity, are desperately needed. Combining different vaccine modalities that are able to complement each other and induce broad and sustainable immunity is a promising approach. This review provides an overview of heterologous prime-boost vaccination modalities currently in development for the 'big three' poverty-related diseases and emphasizes the need for innovative vaccination approaches.

  7. Evaluation of homologous, heterologous, and affinity conjugates for the serodiagnosis of Toxoplasma gondii and Neospora caninum in maned wolves (Chrysocyon brachyurus).

    Science.gov (United States)

    Silva, D A O; Vitaliano, S N; Mineo, T W P; Ferreira, R A; Bevilacqua, E; Mineo, J R

    2005-10-01

    Use of serological tests in the diagnosis of infectious diseases in wild animals has several limitations, primarily the difficulty of obtaining species-specific reagents. Wild canids, such as maned wolves (Chrysocyon brachyurus), are highly predisposed to infection by Toxoplasma gondii and, to a lesser extent, to Neospora caninum. The aim of the present study was to evaluate homologous, heterologous, and affinity conjugates in enzyme-linked immunosorbent assays (ELISAs) and indirect fluorescent antibody tests (IFATs) for detecting immunoglobulin (Ig) G antibodies against T. gondii and N. caninum in maned wolves. Serum samples were obtained from 59 captive animals in Brazil and tested by ELISA for T. gondii serology and IFAT for N. caninum serology using 3 different enzymatic and fluorescent conjugates: homologous (guinea pig anti-maned wolf IgG-peroxidase and -fluorescein isothiocyanate [FITC]), heterologous (rabbit anti-dog IgG-peroxidase and -FITC), and affinity (protein A-peroxidase and -FITC). Seropositivity to T. gondii was comparable among the homologous (69.5%), heterologous (74.6%), and affinity (71.2%) enzymatic conjugates. A significant positive correlation was found between the antibody levels determined by the 3 enzymatic conjugates. The highest mean antibody levels (ELISA index = 4.5) were observed with the protein A-peroxidase conjugate. The same seropositivity to N. caninum (8.5%) was found with the homologous and heterologous fluorescent conjugates, but protein A-FITC was not able to detect or confirm any positive samples with homologous or heterologous conjugates. Our results demonstrate that homologous, heterologous, and affinity conjugates might be used in ELISA for serological assays of T. gondii in wild canids, whereas for N. caninum infection, only the homologous or heterologous fluorescent conjugates have been shown to be useful.

  8. Biochemical mechanisms determine the functional compatibility of heterologous genes

    DEFF Research Database (Denmark)

    Porse, Andreas; Schou, Thea S.; Munck, Christian

    2018-01-01

    -gene libraries have suggested that sequence composition is a strong barrier for the successful integration of heterologous genes. Here we sample 200 diverse genes, representing >80% of sequenced antibiotic resistance genes, to interrogate the factors governing genetic compatibility in new hosts. In contrast...... factors governing the functionality and fitness of antibiotic resistance genes. These findings emphasize the importance of biochemical mechanism for heterologous gene compatibility, and suggest physiological constraints as a pivotal feature orienting the evolution of antibiotic resistance....

  9. Homologous and Heterologous Protection of Nonhuman Primates by Ebola and Sudan Virus-Like Particles

    Science.gov (United States)

    Warfield, Kelly L.; Dye, John M.; Wells, Jay B.; Unfer, Robert C.; Holtsberg, Frederick W.; Shulenin, Sergey; Vu, Hong; Swenson, Dana L.; Bavari, Sina; Aman, M. Javad

    2015-01-01

    Filoviruses cause hemorrhagic fever resulting in significant morbidity and mortality in humans. Several vaccine platforms that include multiple virus-vectored approaches and virus-like particles (VLPs) have shown efficacy in nonhuman primates. Previous studies have shown protection of cynomolgus macaques against homologous infection for Ebola virus (EBOV) and Marburg virus (MARV) following a three-dose vaccine regimen of EBOV or MARV VLPs, as well as heterologous protection against Ravn Virus (RAVV) following vaccination with MARV VLPs. The objectives of the current studies were to determine the minimum number of vaccine doses required for protection (using EBOV as the test system) and then demonstrate protection against Sudan virus (SUDV) and Taï Forest virus (TAFV). Using the EBOV nonhuman primate model, we show that one or two doses of VLP vaccine can confer protection from lethal infection. VLPs containing the SUDV glycoprotein, nucleoprotein and VP40 matrix protein provide complete protection against lethal SUDV infection in macaques. Finally, we demonstrate protective efficacy mediated by EBOV, but not SUDV, VLPs against TAFV; this is the first demonstration of complete cross-filovirus protection using a single component heterologous vaccine within the Ebolavirus genus. Along with our previous results, this observation provides strong evidence that it will be possible to develop and administer a broad-spectrum VLP-based vaccine that will protect against multiple filoviruses by combining only three EBOV, SUDV and MARV components. PMID:25793502

  10. Homologous and heterologous protection of nonhuman primates by Ebola and Sudan virus-like particles.

    Directory of Open Access Journals (Sweden)

    Kelly L Warfield

    Full Text Available Filoviruses cause hemorrhagic fever resulting in significant morbidity and mortality in humans. Several vaccine platforms that include multiple virus-vectored approaches and virus-like particles (VLPs have shown efficacy in nonhuman primates. Previous studies have shown protection of cynomolgus macaques against homologous infection for Ebola virus (EBOV and Marburg virus (MARV following a three-dose vaccine regimen of EBOV or MARV VLPs, as well as heterologous protection against Ravn Virus (RAVV following vaccination with MARV VLPs. The objectives of the current studies were to determine the minimum number of vaccine doses required for protection (using EBOV as the test system and then demonstrate protection against Sudan virus (SUDV and Taï Forest virus (TAFV. Using the EBOV nonhuman primate model, we show that one or two doses of VLP vaccine can confer protection from lethal infection. VLPs containing the SUDV glycoprotein, nucleoprotein and VP40 matrix protein provide complete protection against lethal SUDV infection in macaques. Finally, we demonstrate protective efficacy mediated by EBOV, but not SUDV, VLPs against TAFV; this is the first demonstration of complete cross-filovirus protection using a single component heterologous vaccine within the Ebolavirus genus. Along with our previous results, this observation provides strong evidence that it will be possible to develop and administer a broad-spectrum VLP-based vaccine that will protect against multiple filoviruses by combining only three EBOV, SUDV and MARV components.

  11. Microfluidic platform for electrophysiological recordings from host-stage hookworm and Ascaris suum larvae: A new tool for anthelmintic research

    Directory of Open Access Journals (Sweden)

    Janis C. Weeks

    2016-12-01

    Full Text Available The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device (‘chip’ that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping of the worm's pharynx. These electropharyngeograms (EPGs are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels. Microfluidic technologies have transformed C. elegans research and the goal of the current study was to validate hookworm and Ascaris suum host-stage larvae in the microfluidic EPG platform. Ancylostoma ceylanicum and A. caninum infective L3s (iL3s that had been activated in vitro generally produced erratic EPG activity under the conditions tested. In contrast, A. ceylanicum L4s recovered from hamsters exhibited robust, sustained EPG activity, consisting of three waveforms: (1 conventional pumps as seen in other nematodes; (2 rapid voltage deflections, associated with irregular contractions of the esophagus and openings of the esophogeal-intestinal valve (termed a ‘flutter’; and (3 hybrid waveforms, which we classified as pumps. For data analysis, pumps and flutters were combined and termed EPG ‘events.’ EPG waveform identification and analysis were performed semi-automatically using custom-designed software. The neuromodulator serotonin (5-hydroxytryptamine; 5HT increased EPG event frequency in A. ceylanicum L4s at an optimal concentration of 0.5 mM. The anthelmintic drug ivermectin (IVM inhibited EPG activity in a concentration-dependent manner. EPGs from A. suum L3s recovered from pig lungs exhibited robust pharyngeal pumping in 1 mM 5HT, which was inhibited by IVM. These experiments validate the use of A

  12. Soil-Transmitted Helminths in Children in a Remote Aboriginal Community in the Northern Territory: Hookworm is Rare but Strongyloides stercoralis and Trichuris trichiura Persist

    Directory of Open Access Journals (Sweden)

    Deborah C. Holt

    2017-10-01

    Full Text Available (1 Background: soil-transmitted helminths are a problem worldwide, largely affecting disadvantaged populations. The little data available indicates high rates of infection in some remote Aboriginal communities in Australia. Studies of helminths were carried out in the same remote community in the Northern Territory in 1994–1996 and 2010–2011; (2 Methods: fecal samples were collected from children aged <10 years and examined for helminths by direct smear microscopy. In the 2010–2011 study, some fecal samples were also analyzed by agar plate culture and PCR for Strongyloides stercoralis DNA. Serological analysis of fingerprick dried blood spots using a S. stercoralis NIE antigen was also conducted; (3 Results and Conclusions: a reduction in fecal samples positive for S. stercoralis, hookworm and Trichuris trichiura was seen between the studies in 1994–1996 and 2010–2011, likely reflecting public health measures undertaken in the region to reduce intestinal helminths. Comparison of methods to detect S. stercoralis showed that PCR of fecal samples and serological testing of dried blood spots was at least as sensitive as direct smear microscopy and agar plate culture. These methods have advantages for use in remote field studies.

  13. Heat shock response improves heterologous protein secretion in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Österlund, Tobias; Liu, Zihe

    2013-01-01

    The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often low due to limitations of the host strain. Heat shock response (HSR) is an inducible, global, cellular...... stress response, which facilitates the cell recovery from many forms of stress, e.g., heat stress. In S. cerevisiae, HSR is regulated mainly by the transcription factor heat shock factor (Hsf1p) and many of its targets are genes coding for molecular chaperones that promote protein folding and prevent...... the accumulation of mis-folded or aggregated proteins. In this work, we over-expressed a mutant HSF1 gene HSF1-R206S which can constitutively activate HSR, so the heat shock response was induced at different levels, and we studied the impact of HSR on heterologous protein secretion. We found that moderate and high...

  14. Production of a heterologous proteinase A by Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Møller, Kasper; Tidemand, L.D.; Winther, J.R.

    2001-01-01

    In order to evaluate the potential of Saccharomyces kluyveri for heterologous protein production, S. kluyveri Y159 was transformed with a S. cerevisiae-based multi-copy plasmid containing the S. cerevisiae PEP4 gene, which encodes proteinase A, under the control of its native promoter. As a refer......In order to evaluate the potential of Saccharomyces kluyveri for heterologous protein production, S. kluyveri Y159 was transformed with a S. cerevisiae-based multi-copy plasmid containing the S. cerevisiae PEP4 gene, which encodes proteinase A, under the control of its native promoter...

  15. Virus-mediated suppression of host non-self recognition facilitates horizontal transmission of heterologous viruses.

    Directory of Open Access Journals (Sweden)

    Songsong Wu

    2017-03-01

    Full Text Available Non-self recognition is a common phenomenon among organisms; it often leads to innate immunity to prevent the invasion of parasites and maintain the genetic polymorphism of organisms. Fungal vegetative incompatibility is a type of non-self recognition which often induces programmed cell death (PCD and restricts the spread of molecular parasites. It is not clearly known whether virus infection could attenuate non-self recognition among host individuals to facilitate its spread. Here, we report that a hypovirulence-associated mycoreovirus, named Sclerotinia sclerotiorum mycoreovirus 4 (SsMYRV4, could suppress host non-self recognition and facilitate horizontal transmission of heterologous viruses. We found that cell death in intermingled colony regions between SsMYRV4-infected Sclerotinia sclerotiorum strain and other tested vegetatively incompatible strains was markedly reduced and inhibition barrage lines were not clearly observed. Vegetative incompatibility, which involves Heterotrimeric guanine nucleotide-binding proteins (G proteins signaling pathway, is controlled by specific loci termed het (heterokaryon incompatibility loci. Reactive oxygen species (ROS plays a key role in vegetative incompatibility-mediated PCD. The expression of G protein subunit genes, het genes, and ROS-related genes were significantly down-regulated, and cellular production of ROS was suppressed in the presence of SsMYRV4. Furthermore, SsMYRV4-infected strain could easily accept other viruses through hyphal contact and these viruses could be efficiently transmitted from SsMYRV4-infected strain to other vegetatively incompatible individuals. Thus, we concluded that SsMYRV4 is capable of suppressing host non-self recognition and facilitating heterologous viruses transmission among host individuals. These findings may enhance our understanding of virus ecology, and provide a potential strategy to utilize hypovirulence-associated mycoviruses to control fungal diseases.

  16. HETEROLOGOUS EXPRESSION AND PARTIAL PURIFICATION OF ...

    African Journals Online (AJOL)

    bono

    2011-10-10

    Oct 10, 2011 ... and CYCLOPS in L. japonicus, has been identified ... CYCLOPS, which is phosphorylated in vitro by the CCaMK seems to be important for the infection process in both symbioses, but is dispensable for nodule organogenesis, suggesting ..... Lougnon G, Schornack S, Bono J-J, Cook D R, Ane JM (2007). A.

  17. Hordeum vulgare cysteine protease heterologous expressed in yeast

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben Bach

    , (Hordeum vulgare) endoprotease B2 (HvEPB2) was cloned with and without the 5 amino acid C-terminal sequence into the Pichia pastoris expression vector pPICZ Aα and electrotransformed into Pichia pastoris strain SDM1163. Heterologous protein production was induced with 2% MeOH and the protein expression...

  18. Transcriptional changes in the hookworm, Ancylostoma caninum, during the transition from a free-living to a parasitic larva.

    Directory of Open Access Journals (Sweden)

    Bennett J D Datu

    Full Text Available BACKGROUND: Third-stage larvae (L3 of the canine hookworm, Ancylostoma caninum, undergo arrested development preceding transmission to a host. Many of the mRNAs up-regulated at this stage are likely to encode proteins that facilitate the transition from a free-living to a parasitic larva. The initial phase of mammalian host invasion by A. caninum L3 (herein termed "activation" can be mimicked in vitro by culturing L3 in serum-containing medium. METHODOLOGY/PRINCIPAL FINDINGS: The mRNAs differentially transcribed between activated and non-activated L3 were identified by suppression subtractive hybridisation (SSH. The analysis of these mRNAs on a custom oligonucleotide microarray printed with the SSH expressed sequence tags (ESTs and publicly available A. caninum ESTs (non-subtracted yielded 602 differentially expressed mRNAs, of which the most highly represented sequences encoded members of the pathogenesis-related protein (PRP superfamily and proteases. Comparison of these A. caninum mRNAs with those of Caenorhabditis elegans larvae exiting from developmental (dauer arrest demonstrated unexpectedly large differences in gene ontology profiles. C. elegans dauer exiting L3 up-regulated expression of mostly intracellular molecules involved in growth and development. Such mRNAs are virtually absent from activated hookworm larvae, and instead are over-represented by mRNAs encoding extracellular proteins with putative roles in host-parasite interactions. CONCLUSIONS/SIGNIFICANCE: Although this should not invalidate C. elegans dauer exit as a model for hookworm activation, it highlights the limitations of this free-living nematode as a model organism for the transition of nematode larvae from a free-living to a parasitic state.

  19. Infection,

    Science.gov (United States)

    1980-10-16

    characteristic in severe gram-negative sepsis. Hypertriglyceridemia results from an increase in hepatic synthesis in combination with diminished activity of...induced stress, and tissue repair (1). The magnitude and type of nutritional losses caused by an infection reflect both the severity and duration of an... several functional forms of nutrient loss must be anticipated. Functional losses are defined as the within-body losses of nutrients due to infection

  20. CXCR4 Is Required by a Nonprimate Lentivirus: Heterologous Expression of Feline Immunodeficiency Virus in Human, Rodent, and Feline Cells

    Science.gov (United States)

    Poeschla, Eric M.; Looney, David J.

    1998-01-01

    A heterologous feline immunodeficiency virus (FIV) expression system permitted high-level expression of FIV proteins and efficient production of infectious FIV in human cells. These results identify the FIV U3 element as the sole restriction to the productive phase of replication in nonfeline cells. Heterologous FIV expression in a variety of human cell lines resulted in profuse syncytial lysis that was FIV env specific, CD4 independent, and restricted to cells that express CXCR4, the coreceptor for T-cell-line-adapted strains of human immunodeficiency virus. Stable expression of human CXCR4 in CXCR4-negative human and rodent cell lines resulted in extensive FIV Env-mediated, CXCR4-dependent cell fusion and infection. In feline cells, stable overexpression of human CXCR4 resulted in increased FIV infectivity and marked syncytium formation during FIV replication or after infection with FIV Env-expressing vectors. The use of CXCR4 is a fundamental feature of lentivirus biology independent of CD4 and a shared cellular link to infection and cytopathicity for distantly related lentiviruses that cause AIDS. Their conserved use implicates chemokine receptors as primordial lentivirus receptors. PMID:9658135

  1. P143 proteins from heterologous nucleopolyhedroviruses induce apoptosis in BM-N cells derived from the silkworm Bombyx mori.

    Science.gov (United States)

    Hamajima, Rina; Kobayashi, Michihiro; Ikeda, Motoko

    2017-04-02

    We previously demonstrated that ribosomal RNA (rRNA) of Bombyx mori BM-N cells is rapidly degraded upon infection with heterologous nucleopolyhedroviruses (NPVs), including Autographa californica multiple NPV (AcMNPV), Hyphantria cunea MNPV, Spodoptera exigua MNPV and S. litura MNPV, and that this response is triggered by viral P143 proteins. The transient expression of P143 proteins from heterologous NPVs was also shown to induce apoptosis and caspase-3-like protease activation in BM-N cells. In the present study, we conducted a transient expression assay using BM-N cells expressing mutant AcMNPV P143 (Ac-P143) proteins and demonstrated that five amino acid residues cooperatively participate in Ac-P143 protein-triggered apoptosis of BM-N cells. Notably, these five residues were previously shown to be required for triggering rRNA degradation in BM-N cells. As rRNA degradation in BM-N cells does not result from apoptosis, the present results suggest that Ac-P143-triggered rRNA degradation is the upstream signal for apoptosis induction in BM-N cells. We further showed that P143 protein-triggered apoptosis does not occur in S. frugiperda Sf9 or Lymantria dispar Ld652Y cells, indicating that apoptosis induction by heterologous P143 proteins is a BM-N cell-specific response. In addition, the observed induction of apoptosis in BM-N cells was found to be mediated by activation of the initiator caspase Bm-Dronc. Taken together, these results suggest that BM-N cells evolved a unique antiviral system that recognizes heterologous NPV P143 proteins to induce rRNA degradation and caspase-dependent apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Recombinant lactic acid bacteria as delivery vectors of heterologous antigens: the future of vaccination?

    Science.gov (United States)

    Trombert, A

    2015-01-01

    Lactic acid bacteria (LABs) are good candidates for the development of new oral vaccines and are attractive alternatives to attenuated pathogens. This review focuses on the use of wild-type and recombinant lactococci and lactobacilli with emphasis on their molecular design, immunomodulation and treatment of bacterial infections. The majority of studies related to recombinant LABs have focused on Lactococcus lactis, however, molecular tools have been successfully used for Lactobacillus spp. Recombinant lactobacilli and lactococci have several health benefits, such as immunomodulation, restoration of the microbiota, synthesis of antimicrobial substances and inhibition of virulence factors. In addition, protective immune responses that are well tolerated are induced by the expression of heterologous antigens from recombinant probiotics.

  3. Trivalent combination vaccine induces broad heterologous immune responses to norovirus and rotavirus in mice.

    Directory of Open Access Journals (Sweden)

    Kirsi Tamminen

    Full Text Available Rotavirus (RV and norovirus (NoV are the two major causes of viral gastroenteritis (GE in children worldwide. We have developed an injectable vaccine design to prevent infection or GE induced with these enteric viruses. The trivalent combination vaccine consists of NoV capsid (VP1 derived virus-like particles (VLPs of GI-3 and GII-4 representing the two major NoV genogroups and tubular RV recombinant VP6 (rVP6, the most conserved and abundant RV protein. Each component was produced in insect cells by a recombinant baculovirus expression system and combined in vitro. The vaccine components were administered intramuscularly to BALB/c mice either separately or in the trivalent combination. High levels of NoV and RV type specific serum IgGs with high avidity (>50% as well as intestinal IgGs were detected in the immunized mice. Cross-reactive IgG antibodies were also elicited against heterologous NoV VLPs not used for immunization (GII-4 NO, GII-12 and GI-1 VLPs and to different RVs from cell cultures. NoV-specific serum antibodies blocked binding of homologous and heterologous VLPs to the putative receptors, histo-blood group antigens, suggesting broad NoV neutralizing activity of the sera. Mucosal antibodies of mice immunized with the trivalent combination vaccine inhibited RV infection in vitro. In addition, cross-reactive T cell immune responses to NoV and RV-specific antigens were detected. All the responses were sustained for up to six months. No mutual inhibition of the components in the trivalent vaccine combination was observed. In conclusion, the NoV GI and GII VLPs combination induced broader cross-reactive and potentially neutralizing immune responses than either of the VLPs alone. Therefore, trivalent vaccine might induce protective immune responses to the vast majority of circulating NoV and RV genotypes.

  4. Current prevalence of adult Uncinaria spp. in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, California, with notes on the biology of these hookworms.

    Science.gov (United States)

    Lyons, E T; Melin, S R; DeLong, R L; Orr, A J; Gulland, F M; Tolliver, S C

    2001-06-28

    A prevalence survey for hookworms (Uncinaria spp.) was done in northern fur seal (Callorhinus ursinus) and California sea lion (Zalophus californianus) pups on San Miguel Island, CA, in 2000. Intestines of dead pups were examined for adult hookworms in July. These parasites were found in 95% of 20 fur seal pups and 100% of 31 sea lion pups. The number of hookworms varied from 4 to 2142 (mean = 760) in fur seal pups and from 20 to 2634 (mean = 612) in sea lion pups. A direct relationship was evident between body condition and number of hookworms in the pups; that is, pups in poor condition had fewer hookworms than those in good condition. There was a decline in the number of hookworms in sea lion pups in 2000 compared to collections in 1996. Eggs of Uncinaria spp. were found in rectal feces (collected in late September and early October) of none of 35 (0%) live fur seal pups and 41 of 48 (85%) live sea lion pups. Packed cell volume values, determined for most of the same live pups, were essentially normal for C. ursinus but were much lower than normal for most Z. californianus. Hookworm larvae were not found in blubber of fur seal and sea lion pups or in rookery sand in July. Rookery sand, positive for live hookworm larvae when put in a refrigerator, was negative at removal 2.5 years later. The average number of eggs in utero of female hookworms was 285 for three specimens from a fur seal pup and 281 from three specimens from a sea lion pup. One hookworm larva was recovered from milk stripped from the teats of a stranded Z. californianus female at The Marine Mammal Center, Sausalito, CA.

  5. Intestinal parasite infections in symptomatic children attending hospital in Siem Reap, Cambodia.

    Science.gov (United States)

    Moore, Catrin E; Nget, Phot; Saroeun, Mao; Kuong, Suy; Chanthou, Seng; Kumar, Varun; Bousfield, Rachel; Nader, Johanna; Bailey, J Wendi; Beeching, Nicholas J; Day, Nicholas P; Parry, Christopher M

    2015-01-01

    Infections with helminths and other intestinal parasites are an important but neglected problem in children in developing countries. Accurate surveys of intestinal parasites in children inform empirical treatment regimens and can assess the impact of school based drug treatment programmes. There is limited information on this topic in Cambodia. In a prospective study of intestinal parasites in symptomatic children attending Angkor Hospital for Children, Siem Reap, Cambodia, April-June 2012, samples were examined by microscopy of a direct and concentrated fecal sample. Two culture methods for hookworm and Strongyloides stercoralis were employed when sufficient sample was received. Demographic, clinical and epidemiological data were collected. We studied 970 samples from 865 children. The median (inter-quartile range) age of the children was 5.4 (1.9-9.2) years, 54% were male. The proportion of children with abdominal pain was 66.8%, diarrhea 34.9%, anemia 12.7% and malnutrition 7.4%. 458 parasitic infections were detected in 340 (39.3%) children. The most common parasites using all methods of detection were hookworm (14.3%), Strongyloides stercoralis (11.6%) and Giardia lamblia (11.2%). Giardia lamblia was most common in children aged 1-5 years, hookworm and Strongyloides stercoralis were more common with increasing age. Hookworm, Strongloides stercoralis and Giardia lamblia were more common in children living outside of Siem Reap town. In a multivariate logistic regression increasing age was associated with all three infections, defecating in the forest for hookworm infection, the presence of cattle for S. stercoralis and not using soap for handwashing for G. lamblia. This study confirms the importance of intestinal parasitic infections in symptomatic Cambodian children and the need for adequate facilities for laboratory diagnosis together with education to improve personal hygiene and sanitation.

  6. Intestinal parasite infections in symptomatic children attending hospital in Siem Reap, Cambodia.

    Directory of Open Access Journals (Sweden)

    Catrin E Moore

    Full Text Available Infections with helminths and other intestinal parasites are an important but neglected problem in children in developing countries. Accurate surveys of intestinal parasites in children inform empirical treatment regimens and can assess the impact of school based drug treatment programmes. There is limited information on this topic in Cambodia.In a prospective study of intestinal parasites in symptomatic children attending Angkor Hospital for Children, Siem Reap, Cambodia, April-June 2012, samples were examined by microscopy of a direct and concentrated fecal sample. Two culture methods for hookworm and Strongyloides stercoralis were employed when sufficient sample was received. Demographic, clinical and epidemiological data were collected.We studied 970 samples from 865 children. The median (inter-quartile range age of the children was 5.4 (1.9-9.2 years, 54% were male. The proportion of children with abdominal pain was 66.8%, diarrhea 34.9%, anemia 12.7% and malnutrition 7.4%. 458 parasitic infections were detected in 340 (39.3% children. The most common parasites using all methods of detection were hookworm (14.3%, Strongyloides stercoralis (11.6% and Giardia lamblia (11.2%. Giardia lamblia was most common in children aged 1-5 years, hookworm and Strongyloides stercoralis were more common with increasing age. Hookworm, Strongloides stercoralis and Giardia lamblia were more common in children living outside of Siem Reap town. In a multivariate logistic regression increasing age was associated with all three infections, defecating in the forest for hookworm infection, the presence of cattle for S. stercoralis and not using soap for handwashing for G. lamblia.This study confirms the importance of intestinal parasitic infections in symptomatic Cambodian children and the need for adequate facilities for laboratory diagnosis together with education to improve personal hygiene and sanitation.

  7. Heterologous production of peptides in plants: fusion proteins and beyond.

    Science.gov (United States)

    Viana, Juliane Flávia Cançado; Dias, Simoni Campos; Franco, Octávio Luiz; Lacorte, Cristiano

    2013-11-01

    Recombinant DNA technology has allowed the ectopic production of proteins and peptides of different organisms leading to biopharmaceutical production in large cultures of bacterial, yeasts and mammalian cells. Otherwise, the expression of recombinant proteins and peptides in plants is an attractive alternative presenting several advantages over the commonly used expression systems including reduced production costs, easy scale-up and reduced risks of pathogen contamination. Different types of proteins and peptides have been expressed in plants, including antibodies, antigens, and proteins and peptides of medical, veterinary and industrial applications. However, apart from providing a proof of concept, the use of plants as platforms for heterologous protein and peptide production still depends on key steps towards optimization including the enhancement of expression levels, manipulation of post-transcriptional modifications and improvements in purification methods. In this review, strategies to increase heterologous protein and peptide stability and accumulation are discussed, focusing on the expression of peptides through the use of gene fusions.

  8. The heterologous expression strategies of antimicrobial peptides in microbial systems.

    Science.gov (United States)

    Deng, Ting; Ge, Haoran; He, Huahua; Liu, Yao; Zhai, Chao; Feng, Liang; Yi, Li

    2017-12-01

    Antimicrobial peptides (AMPs) consist of molecules acting on the defense systems of numerous organisms toward tumor and multiple pathogens, such as bacteria, fungi, viruses, and parasites. Compared to traditional antibiotics, AMPs are more stable and have lower propensity for developing resistance through functioning in the innate immune system, thus having important applications in the fields of medicine, food and so on. However, despite of their high economic values, the low yield and the cumbersome extraction process in AMPs production are problems that limit their industrial application and scientific research. To conquer these obstacles, optimized heterologous expression technologies were developed that could provide effective ways to increase the yield of AMPs. In this review, the research progress on heterologous expression of AMPs using Escherichia coli, Bacillus subtilis, Pichia pastoris and Saccharomyces cerevisiae as host cells was mainly summarized, which might guide the expression strategies of AMPs in these cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Kluyveromyces marxianus as a host for heterologous protein synthesis.

    Science.gov (United States)

    Gombert, Andreas K; Madeira, José Valdo; Cerdán, María-Esperanza; González-Siso, María-Isabel

    2016-07-01

    The preferentially respiring and thermotolerant yeast Kluyveromyces marxianus is an emerging host for heterologous protein synthesis, surpassing the traditional preferentially fermenting yeast Saccharomyces cerevisiae in some important aspects: K . marxianus can grow at temperatures 10 °C higher than S. cerevisiae, which may result in decreased costs for cooling bioreactors and reduced contamination risk; has ability to metabolize a wider variety of sugars, such as lactose and xylose; is the fastest growing eukaryote described so far; and does not require special cultivation techniques (such as fed-batch) to avoid fermentative metabolism. All these advantages exist together with a high secretory capacity, performance of eukaryotic post-translational modifications, and with a generally regarded as safe (GRAS) status. In the last years, replication origins from several Kluyveromyces spp. have been used for the construction of episomal vectors, and also integrative strategies have been developed based on the tendency for non-homologous recombination displayed by K. marxianus. The recessive URA3 auxotrophic marker and the dominant Kan(R) are mostly used for selection of transformed cells, but other markers have been made available. Homologous and heterologous promoters and secretion signals have been characterized, with the K. marxianus INU1 expression and secretion system being of remarkable functionality. The efficient synthesis of roughly 50 heterologous proteins has been demonstrated, including one thermophilic enzyme. In this mini-review, we summarize the physiological characteristics of K. marxianus relevant for its use in the efficient synthesis of heterologous proteins, the efforts performed hitherto in the development of a molecular toolbox for this purpose, and some successful examples.

  10. Heterologous expression of antigenic peptides in Bacillus subtilis biofilms.

    Science.gov (United States)

    Vogt, Cédric M; Schraner, Elisabeth M; Aguilar, Claudio; Eichwald, Catherine

    2016-08-11

    Numerous strategies have been developed for the display of heterologous proteins in the surface of live bacterial carriers, which can be used as vaccines, immune-modulators, cancer therapy or bioremediation. Bacterial biofilms have emerged as an interesting approach for the expression of proteins of interest. Bacillus subtilis is a well-described, endospore-forming organism that is able to form biofilms and also used as a probiotic, thus making it a suitable candidate for the display of heterologous proteins within the biofilm. Here, we describe the use of TasA, an important structural component of the biofilms formed by B. subtilis, as a genetic tool for the display of heterologous proteins. We first engineered the fusion protein TasA-mCherry and showed that was widely deployed within the B. subtilis biofilms. A significant enhancement of the expression of TasA-mCherry within the biofilm was obtained when depleting both tasA and sinR genes. We subsequently engineered fusion proteins of TasA to antigenic peptides of the E. granulosus parasite, paramyosin and tropomyosin. Our results show that the antigens were well expressed within the biofilm as denoted by macrostructure complementation and by the detection of the fusion protein in both immunoblot and immunohistochemistry. In addition, we show that the recombinant endospores of B. subtilis preserve their biophysical and morphological properties. In this work we provide strong evidence pointing that TasA is a suitable candidate for the display of heterologous peptides, such as antigens, cytokines, enzymes or antibodies, in the B. subtilis biofilms. Finally, our data portray that the recombinant endospores preserve their morphological and biophysical properties and could be an excellent tool to facilitate the transport and the administration.

  11. Radioimmunoassay with heterologous antibody (hetero-antibody RIA)

    International Nuclear Information System (INIS)

    Iwasawa, Atsushi; Hayashi, Hiroaki; Itoh, Zen; Wakabayashi, Katsumi

    1991-01-01

    To develop a homologous radioimmunoassay (RIA) for a hormone of a small or rare animal often meets difficulty in collecting a large amount of purified antigen required for antibody production. On the other hand, to employ a heterologous RIA to estimate the hormone often gives poor sensitivity. To overcome this difficulty, a 'hetero-antibody' RIA was studied. In a hetero-antibody RIA system, a purified preparation of a hormone is used for radioiodination and standardization and a heterologous antibody to the hormone is used for the first antibody. Canine motilin and rat LH were selected as examples, and anti-porcine motilin and anti-hCG, anti-hCGβ or anti-ovine LHβ was used as the heterologous antibody. The sensitivities of the hetero-antibody RIAs were much higher than those of heterologous RIAs in any case, showing that these hetero-antibody RIA systems were suitable for practical use. To clarify the principle of hetero-antibody RIA, antiserum to porcine motilin was fractionated on an affinity column where canine motilin was immobilized. The fraction bound had greater constants of affinity with both porcine and canine motilins than the rest of the antibody fractions. This fraction also reacted with a synthetic peptide corresponding to the C-terminal sequence common to porcine and canine motilins in a competitive binding test with labeled canine motilin. These results suggest that an antibody population having high affinity and cross-reactivity is present in polyclonal antiserum and indicate that the population can be used in hetero-antibody RIA at an appropriate concentration. (author)

  12. Associations between maternal helminth and malaria infections in pregnancy, and clinical malaria in the offspring

    DEFF Research Database (Denmark)

    Ndibazza, Juliet; Webb, Emily L; Lule, Swaib

    2013-01-01

    Background. Helminth and malaria coinfections are common in the tropics. We investigated the hypothesis that prenatal exposure to these parasites might influence susceptibility to infections such as malaria in childhood.Methods. In a birth cohort of 2,345 mother-child pairs in Uganda, maternal...... helminth and malaria infection status was determined during pregnancy, and childhood malaria episodes recorded from birth to age five years. We examined associations between maternal infections and malaria in the offspring.Results. Common maternal infections were hookworm (45%), Mansonella perstans (21......%), Schistosoma mansoni (18%), and Plasmodium falciparum (11%). At age 5 years, 69% of the children were still under follow-up. The incidence of malaria was 34 episodes per 100 child-years, and the mean prevalence of asymptomatic malaria at annual visits was 5.4%. Maternal hookworm and M. perstans infections were...

  13. The silencing suppressor (NSs) protein of the plant virus Tomato spotted wilt virus enhances heterologous protein expression and baculovirus pathogenicity in cells and lepidopteran insects.

    Science.gov (United States)

    de Oliveira, Virgínia Carla; da Silva Morgado, Fabricio; Ardisson-Araújo, Daniel Mendes Pereira; Resende, Renato Oliveira; Ribeiro, Bergmann Morais

    2015-11-01

    In this work, we showed that cell death induced by a recombinant (vAcNSs) Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing the silencing suppressor (NSs) protein of Tomato spotted wilt virus (TSWV) was enhanced on permissive and semipermissive cell lines. The expression of a heterologous gene (firefly luciferase) during co-infection of insect cells with vAcNSs and a second recombinant baculovirus (vAgppolhfluc) was shown to increase when compared to single vAgppolhfluc infections. Furthermore, the vAcNSs mean time-to-death values were significantly lower than those for wild-type AcMNPV on larvae of Spodoptera frugiperda and Anticarsia gemmatalis. These results showed that the TSWV-NSs protein could efficiently increase heterologous protein expression in insect cells as well as baculovirus pathogenicity and virulence, probably by suppressing the gene-silencing machinery in insects.

  14. Antiviral activity of Small interfering RNAs: Specificity testing using heterologous virus reveals interferon-related effects overlooked by conventional mismatch controls

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Lorenzen, Niels; Pedersen, Finn Skou

    2006-01-01

    to the viral glycoprotein gene of the target-virus efficiently inhibited viral multiplication in infected cell cultures, while two of three corresponding mismatched siRNAs did not have this effect. This suggested specific interference, but similar results were obtained when the same siRNAs were tested against...... a heterologous virus. Further analyses revealed that the siRNAs induced a non-target-specific anti-viral effect correlating with upregulation of the interferon induced Mx gene....

  15. Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa

    Directory of Open Access Journals (Sweden)

    Kvalsvig Jane D

    2004-08-01

    Full Text Available Abstract Background Geohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province. Methods Grade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection. Results The hookworm prevalence in the study population (83.2% was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR of 78.8 and 96.4% and egg reduction rates (ERR of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%. Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels. Conclusion High geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches.

  16. The potential impact of density dependent fecundity on the use of the faecal egg count reduction test for detecting drug resistance in human hookworms.

    Directory of Open Access Journals (Sweden)

    Andrew C Kotze

    Full Text Available Current efforts to control human soil-transmitted helminth (STH infections involve the periodic mass treatment of people, particularly children, in all endemic areas, using benzimidazole and imidothiazole drugs. Given the fact that high levels of resistance have developed to these same drugs in roundworms of livestock, there is a need to monitor drug efficacy in human STHs. The faecal egg count reduction test (FECRT, in which faecal egg output is measured pre- and post-drug treatment, is presently under examination by WHO as a means of detecting the emergence of resistance. We have examined the potential impact of density dependent fecundity on FECRT data. Recent evidence with the canine hookworm indicates that the density dependent egg production phenomenon shows dynamic properties in response to drug treatment. This will impact on measurements of drug efficacy, and hence drug resistance. It is likely that the female worms that survive a FECRT drug treatment in some human cases will respond to the relaxation of density dependent constraints on egg production by increasing their egg output significantly compared to their pre-treatment levels. These cases will therefore underestimate drug efficacy in the FECRT. The degree of underestimation will depend on the ability of the worms within particular hosts to increase their egg output, which will in turn depend on the extent to which their egg output is constrained prior to the drug treatment. As worms within different human cases will likely be present at quite different densities prior to a proposed FECRT, there is potential for the effects of this phenomenon on drug efficacy measurements to vary considerably within any group of potential FECRT candidates. Measurement of relative drug efficacy may be improved by attempting to ensure a consistent degree of underestimation in groups of people involved in separate FECRTs. This may be partly achieved by omission of cases with the heaviest infections

  17. Advances in neglected tropical disease vaccines: Developing relative potency and functional assays for the Na-GST-1/Alhydrogel hookworm vaccine

    Science.gov (United States)

    Brelsford, Jill B.; Plieskatt, Jordan L.; Yakovleva, Anna; Jariwala, Amar; Keegan, Brian P.; Peng, Jin; Xia, Pengjun; Li, Guangzhao; Campbell, Doreen; Periago, Maria Victoria; Correa-Oliveira, Rodrigo; Bottazzi, Maria Elena; Hotez, Peter J.

    2017-01-01

    A new generation of vaccines for the neglected tropical diseases (NTDs) have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, vaccine stability testing programs. A key measure of vaccine stability testing is "relative potency" or the immunogenicity of the vaccine during storage. As with most NTD vaccines, the Na-GST-1/Alhydrogel Hookworm Vaccine was not developed by attenuation or inactivation of the pathogen (Necator americanus), so conventional methods for measuring relative potency are not relevant for this investigational product. Herein, we describe a novel relative potency testing program and report for the first time on the clinical lot of this NTD vaccine during its first 60 months of storage at 2–8°C. We also describe the development of a complementary functional assay that measures the ability of IgG from animals or humans immunized with Na-GST-1/Alhydrogel to neutralize this important hookworm enzyme. While 90% inhibition of the catalytic activity of Na-GST-1 was achieved in animals immunized with Na-GST-1/Alhydrogel, lower levels of inhibition were observed in immunized humans. Moreover, anti-Na-GST-1 antibodies from volunteers in non-hookworm endemic areas were better able to inhibit catalytic activity than anti-Na-GST-1 antibodies from volunteers resident in hookworm endemic areas. The results described herein provide the critical tools for the product development of NTD vaccines. PMID:28192438

  18. Advances in neglected tropical disease vaccines: Developing relative potency and functional assays for the Na-GST-1/Alhydrogel hookworm vaccine.

    Directory of Open Access Journals (Sweden)

    Jill B Brelsford

    2017-02-01

    Full Text Available A new generation of vaccines for the neglected tropical diseases (NTDs have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, vaccine stability testing programs. A key measure of vaccine stability testing is "relative potency" or the immunogenicity of the vaccine during storage. As with most NTD vaccines, the Na-GST-1/Alhydrogel Hookworm Vaccine was not developed by attenuation or inactivation of the pathogen (Necator americanus, so conventional methods for measuring relative potency are not relevant for this investigational product. Herein, we describe a novel relative potency testing program and report for the first time on the clinical lot of this NTD vaccine during its first 60 months of storage at 2-8°C. We also describe the development of a complementary functional assay that measures the ability of IgG from animals or humans immunized with Na-GST-1/Alhydrogel to neutralize this important hookworm enzyme. While 90% inhibition of the catalytic activity of Na-GST-1 was achieved in animals immunized with Na-GST-1/Alhydrogel, lower levels of inhibition were observed in immunized humans. Moreover, anti-Na-GST-1 antibodies from volunteers in non-hookworm endemic areas were better able to inhibit catalytic activity than anti-Na-GST-1 antibodies from volunteers resident in hookworm endemic areas. The results described herein provide the critical tools for the product development of NTD vaccines.

  19. Locating irregularly shaped clusters of infection intensity

    DEFF Research Database (Denmark)

    Yiannakoulias, Niko; Wilson, Shona; Kariuki, H. Curtis

    2010-01-01

    of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the "greedy growth scan" is a suitable method for exploratory geographical analysis...... for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis...

  20. Heterologous Expression in Remodeled C. elegans: A Platform for Monoaminergic Agonist Identification and Anthelmintic Screening.

    Science.gov (United States)

    Law, Wenjing; Wuescher, Leah M; Ortega, Amanda; Hapiak, Vera M; Komuniecki, Patricia R; Komuniecki, Richard

    2015-04-01

    Monoamines, such as 5-HT and tyramine (TA), paralyze both free-living and parasitic nematodes when applied exogenously and serotonergic agonists have been used to clear Haemonchus contortus infections in vivo. Since nematode cell lines are not available and animal screening options are limited, we have developed a screening platform to identify monoamine receptor agonists. Key receptors were expressed heterologously in chimeric, genetically-engineered Caenorhabditis elegans, at sites likely to yield robust phenotypes upon agonist stimulation. This approach potentially preserves the unique pharmacologies of the receptors, while including nematode-specific accessory proteins and the nematode cuticle. Importantly, the sensitivity of monoamine-dependent paralysis could be increased dramatically by hypotonic incubation or the use of bus mutants with increased cuticular permeabilities. We have demonstrated that the monoamine-dependent inhibition of key interneurons, cholinergic motor neurons or body wall muscle inhibited locomotion and caused paralysis. Specifically, 5-HT paralyzed C. elegans 5-HT receptor null animals expressing either nematode, insect or human orthologues of a key Gαo-coupled 5-HT1-like receptor in the cholinergic motor neurons. Importantly, 8-OH-DPAT and PAPP, 5-HT receptor agonists, differentially paralyzed the transgenic animals, with 8-OH-DPAT paralyzing mutant animals expressing the human receptor at concentrations well below those affecting its C. elegans or insect orthologues. Similarly, 5-HT and TA paralyzed C. elegans 5-HT or TA receptor null animals, respectively, expressing either C. elegans or H. contortus 5-HT or TA-gated Cl- channels in either C. elegans cholinergic motor neurons or body wall muscles. Together, these data suggest that this heterologous, ectopic expression screening approach will be useful for the identification of agonists for key monoamine receptors from parasites and could have broad application for the identification

  1. Heterologous Expression in Remodeled C. elegans: A Platform for Monoaminergic Agonist Identification and Anthelmintic Screening.

    Directory of Open Access Journals (Sweden)

    Wenjing Law

    2015-04-01

    Full Text Available Monoamines, such as 5-HT and tyramine (TA, paralyze both free-living and parasitic nematodes when applied exogenously and serotonergic agonists have been used to clear Haemonchus contortus infections in vivo. Since nematode cell lines are not available and animal screening options are limited, we have developed a screening platform to identify monoamine receptor agonists. Key receptors were expressed heterologously in chimeric, genetically-engineered Caenorhabditis elegans, at sites likely to yield robust phenotypes upon agonist stimulation. This approach potentially preserves the unique pharmacologies of the receptors, while including nematode-specific accessory proteins and the nematode cuticle. Importantly, the sensitivity of monoamine-dependent paralysis could be increased dramatically by hypotonic incubation or the use of bus mutants with increased cuticular permeabilities. We have demonstrated that the monoamine-dependent inhibition of key interneurons, cholinergic motor neurons or body wall muscle inhibited locomotion and caused paralysis. Specifically, 5-HT paralyzed C. elegans 5-HT receptor null animals expressing either nematode, insect or human orthologues of a key Gαo-coupled 5-HT1-like receptor in the cholinergic motor neurons. Importantly, 8-OH-DPAT and PAPP, 5-HT receptor agonists, differentially paralyzed the transgenic animals, with 8-OH-DPAT paralyzing mutant animals expressing the human receptor at concentrations well below those affecting its C. elegans or insect orthologues. Similarly, 5-HT and TA paralyzed C. elegans 5-HT or TA receptor null animals, respectively, expressing either C. elegans or H. contortus 5-HT or TA-gated Cl- channels in either C. elegans cholinergic motor neurons or body wall muscles. Together, these data suggest that this heterologous, ectopic expression screening approach will be useful for the identification of agonists for key monoamine receptors from parasites and could have broad application for

  2. Expression of Heterologous Cellulases in Thermotoga sp. Strain RQ2

    Directory of Open Access Journals (Sweden)

    Hui Xu

    2015-01-01

    Full Text Available The ability of Thermotoga spp. to degrade cellulose is limited due to a lack of exoglucanases. To address this deficiency, cellulase genes Csac_1076 (celA and Csac_1078 (celB from Caldicellulosiruptor saccharolyticus were cloned into T. sp. strain RQ2 for heterologous overexpression. Coding regions of Csac_1076 and Csac_1078 were fused to the signal peptide of TM1840 (amyA and TM0070 (xynB, resulting in three chimeric enzymes, namely, TM1840-Csac_1078, TM0070-Csac_1078, and TM0070-Csac_1076, which were carried by Thermotoga-E. coli shuttle vectors pHX02, pHX04, and pHX07, respectively. All three recombinant enzymes were successfully expressed in E. coli DH5α and T. sp. strain RQ2, rendering the hosts with increased endo- and/or exoglucanase activities. In E. coli, the recombinant enzymes were mainly bound to the bacterial cells, whereas in T. sp. strain RQ2, about half of the enzyme activities were observed in the culture supernatants. However, the cellulase activities were lost in T. sp. strain RQ2 after three consecutive transfers. Nevertheless, this is the first time heterologous genes bigger than 1 kb (up to 5.3 kb in this study have ever been expressed in Thermotoga, demonstrating the feasibility of using engineered Thermotoga spp. for efficient cellulose utilization.

  3. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans.

    Science.gov (United States)

    Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.

  4. Heterologous expression of the methyl carbamate-degrading hydrolase MCD.

    Science.gov (United States)

    Naqvi, Tatheer; Cheesman, Matthew J; Williams, Michelle R; Campbell, Peter M; Ahmed, Safia; Russell, Robyn J; Scott, Colin; Oakeshott, John G

    2009-10-26

    The methyl carbamate-degrading hydrolase (MCD) of Achromobacter WM111 has considerable potential as a pesticide bioremediation agent. However this potential has been unrealisable until now because of an inability to express MCD in heterologous hosts such as Escherichia coli. Herein, we describe the first successful attempt to express appreciable quantities of MCD in active form in E. coli, and the subsequent characterisation of the heterologously expressed material. We find that the properties of this material closely match the previously reported properties of MCD produced from Achromobacter WM111. This includes the presence of two distinct forms of the enzyme that we show are most likely due to the presence of two functional translational start sites. The purified enzyme catalyses the hydrolysis of a carbamate (carbaryl), a carboxyl ester (alpha-naphthyl acetate) and a phophotriester (dimethyl umbelliferyl phosphate) and it is relatively resistant to thermal and solvent-mediated denaturation. The robust nature and catalytic promiscuity of MCD suggest that it could be exploited for various biotechnological applications.

  5. A Distinct Class of Genome Rearrangements Driven by Heterologous Recombination.

    Science.gov (United States)

    León-Ortiz, Ana María; Panier, Stephanie; Sarek, Grzegorz; Vannier, Jean-Baptiste; Patel, Harshil; Campbell, Peter J; Boulton, Simon J

    2018-01-18

    Erroneous DNA repair by heterologous recombination (Ht-REC) is a potential threat to genome stability, but evidence supporting its prevalence is lacking. Here we demonstrate that recombination is possible between heterologous sequences and that it is a source of chromosomal alterations in mitotic and meiotic cells. Mechanistically, we find that the RTEL1 and HIM-6/BLM helicases and the BRCA1 homolog BRC-1 counteract Ht-REC in Caenorhabditis elegans, whereas mismatch repair does not. Instead, MSH-2/6 drives Ht-REC events in rtel-1 and brc-1 mutants and excessive crossovers in rtel-1 mutant meioses. Loss of vertebrate Rtel1 also causes a variety of unusually large and complex structural variations, including chromothripsis, breakage-fusion-bridge events, and tandem duplications with distant intra-chromosomal insertions, whose structure are consistent with a role for RTEL1 in preventing Ht-REC during break-induced replication. Our data establish Ht-REC as an unappreciated source of genome instability that underpins a novel class of complex genome rearrangements that likely arise during replication stress. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  6. In vivo myomaker-mediated heterologous fusion and nuclear reprogramming.

    Science.gov (United States)

    Mitani, Yasuyuki; Vagnozzi, Ronald J; Millay, Douglas P

    2017-01-01

    Knowledge regarding cellular fusion and nuclear reprogramming may aid in cell therapy strategies for skeletal muscle diseases. An issue with cell therapy approaches to restore dystrophin expression in muscular dystrophy is obtaining a sufficient quantity of cells that normally fuse with muscle. Here we conferred fusogenic activity without transdifferentiation to multiple non-muscle cell types and tested dystrophin restoration in mouse models of muscular dystrophy. We previously demonstrated that myomaker, a skeletal muscle-specific transmembrane protein necessary for myoblast fusion, is sufficient to fuse 10T 1/2 fibroblasts to myoblasts in vitro. Whether myomaker-mediated heterologous fusion is functional in vivo and whether the newly introduced nonmuscle nuclei undergoes nuclear reprogramming has not been investigated. We showed that mesenchymal stromal cells, cortical bone stem cells, and tail-tip fibroblasts fuse to skeletal muscle when they express myomaker. These cells restored dystrophin expression in a fraction of dystrophin-deficient myotubes after fusion in vitro. However, dystrophin restoration was not detected in vivo although nuclear reprogramming of the muscle-specific myosin light chain promoter did occur. Despite the lack of detectable dystrophin reprogramming by immunostaining, this study indicated that myomaker could be used in nonmuscle cells to induce fusion with muscle in vivo, thereby providing a platform to deliver therapeutic material.-Mitani, Y., Vagnozzi, R. J., Millay, D. P. In vivo myomaker-mediated heterologous fusion and nuclear reprogramming. © FASEB.

  7. Humans and great apes cohabiting the forest ecosystem in central african republic harbour the same hookworms

    Czech Academy of Sciences Publication Activity Database

    Hasegawa, H.; Modrý, David; Kitagawa, M.; Shutt, K. A.; Todd, A.; Kalousová, B.; Profousová, I.; Petrželková, Klára Judita

    2014-01-01

    Roč. 8, č. 3 (2014), e2715 ISSN 1935-2735 Institutional support: RVO:60077344 Keywords : Necator spp. * mountain gorillas * infection * chimpanzees * Dzanga-Sangha Protected Areas * Central African Republic Subject RIV: EG - Zoology Impact factor: 4.446, year: 2014

  8. Humans and great apes cohabiting the forest ecosystem in Central African Republic harbour the same hookworms

    Czech Academy of Sciences Publication Activity Database

    Hasegawa, H.; Modrý, D.; Kitagawa, M.; Shutt, K. A.; Todd, A.; Kalousová, B.; Profousová, I.; Petrželková, Klára Judita

    2014-01-01

    Roč. 8, č. 3 (2014), e2715 ISSN 1935-2735 R&D Projects: GA ČR GA206/09/0927 Institutional support: RVO:68081766 Keywords : Necator spp. * mountain gorillas * infection * chimpanzees * Dzanga-Sangha Protected Areas, Central African Republic Subject RIV: EG - Zoology Impact factor: 4.446, year: 2014

  9. Profilaxia da anemia ancilostomótica: sindrome de carencia Prophylaxis of Hookworm Anemia-carencial syndrome

    Directory of Open Access Journals (Sweden)

    W. O. Cruz

    1945-04-01

    anti-helmíntica, que além de onerosos são pouco práticos, pois interferem em hábitos enraizados nas populações rurais.A review of the recent advances in the mechanism of hookworm anemia is presented, pointing out the importance of a qualitatively defective nutrition in the genesis of this disease. The carencial aspect of hookworm anemia is emphasized. The accepted prophylaxia of hookworm disease limits itself to avoiding human infestation by the ancylostomidae. This method is criticized as a pratical means of eradicating the anemia in rural population. This paper deals with preliminary studies to build up a carencial type of prophylaxis in hookworm anemia (as in prophylaxis of endemic goitre based on the administration of iron salts, in the food usually consumed in Brazil. The mixtures ferrous sulphate and mandioca flour or amoniacal ferric citrate and baked beans, have been able to prevent anemia in patients heavely infested. during long periods of time (6-8 months. the minimus efficient daily doses of iron needed to maintain normal blood levels have not been precisely ascertained, but even 0.1 g of ferrous sulphate (37 mg of metalic iron daily in mandioca flour was satisfatory for that purpose. Different foods and iron salts have been tried with no results, for different reasons. When iron salts were administered in insufficient doses, the progressive evolution of the anemia was observed in detail. In conclusion the use of iron salts in suficient quantities mixed to usual food is advised as a prophylatic method is hookworm anemia. A campaign of this type can be accomplished at extremely low cost, and probably has definite advantages over the classical prophylaxis, whose methods interferes with rooted habits of people of rural areas and therefore give very poor practical results.

  10. Modelling the geographical distribution of soil-transmitted helminth infections in Bolivia.

    Science.gov (United States)

    Chammartin, Frédérique; Scholte, Ronaldo G C; Malone, John B; Bavia, Mara E; Nieto, Prixia; Utzinger, Jürg; Vounatsou, Penelope

    2013-05-25

    The prevalence of infection with the three common soil-transmitted helminths (i.e. Ascaris lumbricoides, Trichuris trichiura, and hookworm) in Bolivia is among the highest in Latin America. However, the spatial distribution and burden of soil-transmitted helminthiasis are poorly documented. We analysed historical survey data using Bayesian geostatistical models to identify determinants of the distribution of soil-transmitted helminth infections, predict the geographical distribution of infection risk, and assess treatment needs and costs in the frame of preventive chemotherapy. Rigorous geostatistical variable selection identified the most important predictors of A. lumbricoides, T. trichiura, and hookworm transmission. Results show that precipitation during the wettest quarter above 400 mm favours the distribution of A. lumbricoides. Altitude has a negative effect on T. trichiura. Hookworm is sensitive to temperature during the coldest month. We estimate that 38.0%, 19.3%, and 11.4% of the Bolivian population is infected with A. lumbricoides, T. trichiura, and hookworm, respectively. Assuming independence of the three infections, 48.4% of the population is infected with any soil-transmitted helminth. Empirical-based estimates, according to treatment recommendations by the World Health Organization, suggest a total of 2.9 million annualised treatments for the control of soil-transmitted helminthiasis in Bolivia. We provide estimates of soil-transmitted helminth infections in Bolivia based on high-resolution spatial prediction and an innovative variable selection approach. However, the scarcity of the data suggests that a national survey is required for more accurate mapping that will govern spatial targeting of soil-transmitted helminthiasis control.

  11. Development and evaluation of an efficient heterologous gene knock-in reporter system in Lactococcus lactis.

    Science.gov (United States)

    Lu, Yifei; Yan, Hongxiang; Deng, Jiezhong; Huang, Zhigang; Jin, Xurui; Yu, Yanlan; Hu, Qiwen; Hu, Fuquan; Wang, Jing

    2017-09-18

    Lactococcus lactis is a food grade probiotics and widely used to express heterologous proteins. Generally, target genes are knocked into the L. lactis genome through double-crossover recombination to express heterologous proteins stably. However, creating marker-less heterologous genes knocked-in clones is laborious. In this study, an efficient heterologous gene knock-in reporter system was developed in L. lactis NZ9000. Our knock-in reporter system consists of a temperature-sensitive plasmid pJW and a recombinant L. lactis strain named NZB. The pJW contains homologous arms, and was constructed to knock-in heterologous genes at a fixed locus of NZ9000 genome. lacZ (β-galactosidase) gene was knocked into the chromosome of NZ9000 as a counter-selective marker through the plasmid pJW to generate NZB. The engineered NZB strain formed blue colonies on X-Gal plate. The desired double-crossover mutants formed white colonies distinctive from the predominantly blue colonies (parental and plasmid-integrated clones) when the embedded lacZ was replaced with the target heterologous genes carried by pJW in NZB. By using the system, the heterologous gene knocked-in clones are screened by colony phenotype change rather than by checking colonies individually. Our new knock-in reporter system provides an efficient method to create heterologous genes knocked-in clones.

  12. Parasite infection is associated with Kaposi's sarcoma associated herpesvirus (KSHV in Ugandan women

    Directory of Open Access Journals (Sweden)

    Ndibazza Juliet

    2011-09-01

    Full Text Available Abstract Background Immune modulation by parasites may influence susceptibility to bacteria and viruses. We examined the association between current parasite infections, HIV and syphilis (measured in blood or stool samples using standard methods and antibodies against Kaposi's sarcoma herpesvirus (KSHV, measured by ELISA, in 1915 stored plasma samples from pregnant women in Entebbe, Uganda. Results Seroprevalence of KSHV was higher in women with malaria parasitaemia (73% vs 60% p = 0.01, hookworm (67% vs 56% p = 0.001 and Mansonella perstans (69% vs 59% p = 0.05; seroprevalence increased with increasing intensity of hookworm infection (p Conclusions Specific parasite infections are associated with presence of antibodies against KSHV, perhaps mediated via their effect on immune function.

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

    Science.gov (United States)

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

    2014-08-01

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

  14. Locating irregularly shaped clusters of infection intensity

    Directory of Open Access Journals (Sweden)

    Niko Yiannakoulias

    2010-05-01

    Full Text Available Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until recently, cluster detection methods were limited in their ability to detect irregular spatial patterns, and limited to finding clusters that were roughly circular in shape. This approach has less power to detect irregularly-shaped, yet important spatial anomalies, particularly at high spatial resolutions. We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the “greedy growth scan”, is a modification of the spatial scan method for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the “greedy growth scan” is a suitable method for exploratory geographical analysis of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales.

  15. Functional expression and evaluation of heterologous phosphoketolases in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Bergman, Alexandra; Siewers, Verena; Nielsen, Jens

    2016-01-01

    Phosphoketolases catalyze an energy-and redox-independent cleavage of certain sugar phosphates. Hereby, the two-carbon (C2) compound acetyl-phosphate is formed, which enzymatically can be converted into acetyl-CoA-a key precursor in central carbon metabolism. Saccharomyces cerevisiae does...... not demonstrate efficient phosphoketolase activity naturally. In this study, we aimed to compare and identify efficient heterologous phosphoketolase enzyme candidates that in yeast have the potential to reduce carbon loss compared to the native acetyl-CoA producing pathway by redirecting carbon flux directly from...... C5 and C6 sugars towards C2-synthesis. Nine phosphoketolase candidates were expressed in S. cerevisiae of which seven produced significant amounts of acetyl-phosphate after provision of sugar phosphate substrates in vitro. The candidates showed differing substrate specificities, and some...

  16. Heterologous embryo transfer: Magisterial answers and metaphysical questions.

    Science.gov (United States)

    Accad, Michel

    2014-02-01

    The debate regarding the morality of heterologous embryo transfer (HET) as a solution for the fate of cryopreserved embryos remains active. This paper endeavors to show that the magisterial instructions on bioethical issues can only lead to the conclusion that HET is always morally illicit. I begin by showing that the text of Dignitas personae recognizes HET as a procedure accomplishing a procreative function, and I indicate that it is through gestation that this procreative function occurs. I further show that the previous Instruction, Donum vitae, implicitly points to an ontological or spiritual consideration at play during gestation. This consideration is likely related to the procreative function identified in Dignitas personae. Finally, I place these two textual arguments in the context of the debate concerning HET and conclude that metaphysical questions must be clarified in order for the immorality of HET to be understood from a suitable anthropological perspective and gain more widespread acceptance.

  17. Heterologous transporter expression for improved fatty alcohol secretion in yeast

    DEFF Research Database (Denmark)

    Hu, Yating; Zhu, Zhiwei; Nielsen, Jens

    2017-01-01

    The yeast Saccharomyces cerevisiae is an attractive host for industrial scale production of biofuels including fatty alcohols due to its robustness and tolerance towards harsh fermentation conditions. Many metabolic engineering strategies have been applied to generate high fatty alcohol production...... transporters tested, human FATP1 was shown to mediate fatty alcohol export in a high fatty alcohol production yeast strain. An approximately five-fold increase of fatty alcohol secretion was achieved. The results indicate that the overall cell fitness benefited from fatty alcohol secretion and that the acyl......-CoA synthase activity of FATP1 contributed to increased cell growth as well. This is the first study that enabled an increased cell fitness for fatty alcohol production by heterologous transporter expression in yeast, and this investigation indicates a new potential function of FATP1, which has been known...

  18. Babesia divergens: protection of intact calves against heterologous challenge by the injection of irradiated piroplasms

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D; Purnell, R E; Brocklesby, D W [Agricultural Research Council, Compton (UK). Inst. for Research on Animal Diseases

    1980-03-01

    Blood from a splenectomized calf infected with Babesia divergens was divided into 20 ml aliquots which were ..gamma..-irradiated at doses of 0, 24, 28, 32, 36 and 40 krad and then inoculated into groups of three intact calves. Animals receiving non-irradiated blood had typical mild B. divergens reactions, but those receiving irradiated blood had either very mild reactions or no overt reaction. When the calves were challenged with a similar number (7.5 X 10/sup 9/) of heterologous parasites of a recently-isolated field strain, those which had received blood irradiated at 0, 24, 28 and 32 krad were all immune whereas four of the five surviving animals which had received blood irradiated at 36 or 40 krad were susceptible. The immune status of individual cattle was reflected accurately in the results of the micro-ELISA test, which detected a significant rise in serum antibody titre of the four susceptible animals by day 21 after challenge.

  19. Babesia divergens: protection of intact calves against heterologous challenge by the injection of irradiated piroplasms

    International Nuclear Information System (INIS)

    Lewis, D.; Purnell, R.E.; Brocklesby, D.W.

    1980-01-01

    Blood from a splenectomized calf infected with Babesia divergens was divided into 20 ml aliquots which were γ-irradiated at doses of 0, 24, 28, 32, 36 and 40 krad and then inoculated into groups of three intact calves. Animals receiving non-irradiated blood had typical mild B. divergens reactions, but those receiving irradiated blood had either very mild reactions or no overt reaction. When the calves were challenged with a similar number (7.5 X 10 9 ) of heterologous parasites of a recently-isolated field strain, those which had received blood irradiated at 0, 24, 28 and 32 krad were all immune whereas four of the five surviving animals which had received blood irradiated at 36 or 40 krad were susceptible. The immune status of individual cattle was reflected accurately in the results of the micro-ELISA test, which detected a significant rise in serum antibody titre of the four susceptible animals by day 21 after challenge. (Auth.)

  20. A heterologous prime-boost Ebola virus vaccine regimen induces durable neutralizing antibody response and prevents Ebola virus-like particle entry in mice.

    Science.gov (United States)

    Chen, Tan; Li, Dapeng; Song, Yufeng; Yang, Xi; Liu, Qingwei; Jin, Xia; Zhou, Dongming; Huang, Zhong

    2017-09-01

    Ebola virus (EBOV) is one of the most virulent pathogens known to humans. Neutralizing antibodies play a major role in the protection against EBOV infections. Thus, an EBOV vaccine capable of inducing a long-lasting neutralizing antibody response is highly desirable. We report here that a heterologous prime-boost vaccine regimen can elicit durable EBOV-neutralizing antibody response in mice. A chimpanzee serotype 7 adenovirus expressing EBOV GP (denoted AdC7-GP) was generated and used for priming. A truncated version of EBOV GP1 protein (denoted GP1t) was produced at high levels in Drosophila S2 cells and used for boosting. Mouse immunization studies showed that the AdC7-GP prime/GP1t boost vaccine regimen was more potent in eliciting neutralizing antibodies than either the AdC7-GP or GP1t alone. Neutralizing antibodies induced by the heterologous prime-boost regimen sustained at high titers for at least 18 weeks after immunization. Significantly, in vivo challenge studies revealed that the entry of reporter EBOV-like particles was efficiently blocked in mice receiving the heterologous prime-boost regimen even at 18 weeks after the final dose of immunization. These results suggest that this novel AdC7-GP prime/GP1t boost regimen represents an EBOV vaccine approach capable of establishing long-term protection, and therefore warrants further development. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Homologous and heterologous antibody responses of mice immunized with purified feline herpesvirus type 1 and canine herpesvirus glycoproteins.

    Science.gov (United States)

    Limcumpao, J A; Horimoto, T; Xuan, X N; Tohya, Y; Azetaka, M; Takahashi, E; Mikami, T

    1991-06-01

    The three glycoproteins each of feline herpesvirus type 1 (FHV-1) and canine herpesvirus (CHV) were purified by affinity chromatography using glycoprotein-specific monoclonal antibodies and used individually or in combination in immunizing mice to determine their relative immunogenicity. All the glycoproteins induced detectable virus neutralizing antibodies to the homologous virus but FHV-1 gp143/108 and its cross-reacting counterpart, CHV gp145/112, elicited the highest titers not only to the homologous virus but to the heterologous virus as well. The production of ELISA antibodies after glycoprotein immunization was variable, while hemagglutination-inhibiting antibodies were produced by only 1 out of 10 FHV-1 gp60-inoculated mice. In general, the antibody titers induced by CHV glycoproteins were lower than those by FHV-1 glycoproteins. These results indicate that these glycoproteins may be useful as subunit vaccines against FHV-1 and CHV infections.

  2. Protection of macaques with diverse MHC genotypes against a heterologous SIV by vaccination with a deglycosylated live-attenuated SIV.

    Directory of Open Access Journals (Sweden)

    Chie Sugimoto

    Full Text Available HIV vaccine development has been hampered by issues such as undefined correlates of protection and extensive diversity of HIV. We addressed these issues using a previously established SIV-macaque model in which SIV mutants with deletions of multiple gp120 N-glycans function as potent live attenuated vaccines to induce near-sterile immunity against the parental pathogenic SIVmac239. In this study, we investigated the protective efficacy of these mutants against a highly pathogenic heterologous SIVsmE543-3 delivered intravenously to rhesus macaques with diverse MHC genotypes. All 11 vaccinated macaques contained the acute-phase infection with blood viral loads below the level of detection between 4 and 10 weeks postchallenge (pc, following a transient but marginal peak of viral replication at 2 weeks in only half of the challenged animals. In the chronic phase, seven vaccinees contained viral replication for over 80 weeks pc, while four did not. Neutralizing antibodies against challenge virus were not detected. Although overall levels of SIV specific T cell responses did not correlate with containment of acute and chronic viral replication, a critical role of cellular responses in the containment of viral replication was suggested. Emergence of viruses with altered fitness due to recombination between the vaccine and challenge viruses and increased gp120 glycosylation was linked to the failure to control SIV. These results demonstrate the induction of effective protective immune responses in a significant number of animals against heterologous virus by infection with deglycosylated attenuated SIV mutants in macaques with highly diverse MHC background. These findings suggest that broad HIV cross clade protection is possible, even in hosts with diverse genetic backgrounds. In summary, results of this study indicate that deglycosylated live-attenuated vaccines may provide a platform for the elucidation of correlates of protection needed for a

  3. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Milne, N.; Luttik, M.A.H.; Cueto Rojas, H.F.; Wahl, A.; Van Maris, A.J.A.; Pronk, J.T.; Daran, J.G.

    2015-01-01

    In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential

  4. Heterologous stable expression of terpenoid biosynthetic genes using the moss Physcomitrella patens

    DEFF Research Database (Denmark)

    Bach, Søren Spanner; King, Brian Christopher; Zhan, Xin

    2014-01-01

    Heterologous and stable expression of genes encoding terpenoid biosynthetic enzymes in planta is an important tool for functional characterization and is an attractive alternative to expression in microbial hosts for biotechnological production. Despite improvements to the procedure, such as stre...

  5. Targeting a heterologous protein to multiple plant organelles via rationally designed 5? mRNA tags

    NARCIS (Netherlands)

    Voges, M.J.; Silver, P.A.; Way, J.C.; Mattozzi, M.D.

    2013-01-01

    Background Plant bioengineers require simple genetic devices for predictable localization of heterologous proteins to multiple subcellular compartments. Results We designed novel hybrid signal sequences for multiple-compartment localization and characterize their function when fused to GFP in

  6. Transcriptional analysis of heterologous gene expression using the endogenous sD promoter from Bacillus halodurans

    CSIR Research Space (South Africa)

    Crampton, Michael C

    2010-07-01

    Full Text Available This presentation focused on the transcriptional analysis of heterologous gene expression using the endogenous sD promoter from Bacillus halodurans. It concludes to a successful implementation of a high throughput mRNA sandwich hybridisation...

  7. Improvement of heterologous protein production in Aspergillus oryzae by RNA interference with alpha-amylase genes.

    Science.gov (United States)

    Nemoto, Takashi; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

    2009-11-01

    Aspergillus oryzae RIB40 has three alpha-amylase genes (amyA, amyB, and amyC), and secretes alpha-amylase abundantly. However, large amounts of endogenous secretory proteins such as alpha-amylase can compete with heterologous protein in the secretory pathway and decrease its production yields. In this study, we examined the effects of suppression of alpha-amylase on heterologous protein production in A. oryzae, using the bovine chymosin (CHY) as a reporter heterologous protein. The three alpha-amylase genes in A. oryzae have nearly identical DNA sequences from those promoters to the coding regions. Hence we performed silencing of alpha-amylase genes by RNA interference (RNAi) in the A. oryzae CHY producing strain. The silenced strains exhibited a reduction in alpha-amylase activity and an increase in CHY production in the culture medium. This result suggests that suppression of alpha-amylase is effective in heterologous protein production in A. oryzae.

  8. Use of heterologous expressed polyketide synthase and small molecule foldases to make aromatic and cyclic compounds

    DEFF Research Database (Denmark)

    2016-01-01

    A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell.......A method for producing individual or libraries of tri- to pentadecaketide-derived aromatic compounds of interest by heterologous expression of polyketide synthase and aromatase/cyclase in a recombinant host cell....

  9. From fresh heterologous oocyte donation to autologous oocyte banking.

    Science.gov (United States)

    Stoop, D

    2012-01-01

    Today, oocyte donation has become well established, giving rise to thousands of children born worldwide annually. The introduction of oocyte cryopreservation through vitrification allows the introduction of egg banking, improving the efficiency and comfort of oocyte donation. Moreover, the vitrification technique can now enable autologous donation of oocytes to prevent future infertility. We evaluated fresh heterologous oocyte donation in terms of obstetrical and perinatal outcome as well as of the reproductive outcome of past donors. We then evaluated the efficiency of a closed vitrification device and its clinical applications within ART. Thirdly, we evaluated the opinion of women with regard to preventive egg freezing and the efficiency of a human oocyte in relation to age. Oocyte donation is associated with an increased risk of first trimester bleeding and pregnancy induced hypertension. Donating oocytes does not seem to increase the likelihood for a later need of fertility treatment. The chance of an oocyte to result in live birth (utilization rate) in women women would consider safeguarding their reproductive potential through egg freezing or are at least open to the idea. The introduction of efficient oocyte cryopreservation has revolutionized oocyte donation through the establishment of eggbank donation. The technique also enables women to perform autologous donation after preventive oocyte storage in order to circumvent their biological clock.

  10. Characterization of a Lactococcus lactis promoter for heterologous protein production

    Directory of Open Access Journals (Sweden)

    Christian E. Ogaugwu

    2018-03-01

    Full Text Available Constitutively active promoter elements for heterologous protein production in Lactococcus lactis are scarce. Here, the promoter of the PTS-IIC gene cluster from L. lactis NZ3900 is described. This promoter was cloned upstream of an enhanced green fluorescent protein, GFPmut3a, and transformed into L. lactis. Transformants produced up to 13.5 μg of GFPmut3a per milliliter of log phase cells. Addition of cellobiose further increased the production of GFPmut3a by up to two-fold when compared to glucose. Analysis of mutations at two specific positions in the PTS-IIC promoter showed that a ‘T’ to ‘G’ mutation within the −35 element resulted in constitutive expression in glucose, while a ‘C’ at nucleotide 7 in the putative cre site enhanced promoter activity in cellobiose. Finally, this PTS-IIC promoter is capable of mediating protein expression in Bacillus subtilis and Escherichia coli Nissle 1917, suggesting the potential for future biotechnological applications of this element and its derivatives.

  11. Experimental infection of pregnant goats with bovine viral diarrhea virus (BVDV)1 or 2

    Science.gov (United States)

    Infections with bovine viral diarrhea virus (BVDV) of the genus pestivirus, family Flaviviridae, are not limited to cattle but occur in various artiodactyls. Persistently infected (PI) cattle are the main source of BVDV. Persistent infections also occur in heterologous hosts such as sheep and deer. ...

  12. An in silico platform for the design of heterologous pathways in nonnative metabolite production

    Directory of Open Access Journals (Sweden)

    Chatsurachai Sunisa

    2012-05-01

    Full Text Available Abstract Background Microorganisms are used as cell factories to produce valuable compounds in pharmaceuticals, biofuels, and other industrial processes. Incorporating heterologous metabolic pathways into well-characterized hosts is a major strategy for obtaining these target metabolites and improving productivity. However, selecting appropriate heterologous metabolic pathways for a host microorganism remains difficult owing to the complexity of metabolic networks. Hence, metabolic network design could benefit greatly from the availability of an in silico platform for heterologous pathway searching. Results We developed an algorithm for finding feasible heterologous pathways by which nonnative target metabolites are produced by host microorganisms, using Escherichia coli, Corynebacterium glutamicum, and Saccharomyces cerevisiae as templates. Using this algorithm, we screened heterologous pathways for the production of all possible nonnative target metabolites contained within databases. We then assessed the feasibility of the target productions using flux balance analysis, by which we could identify target metabolites associated with maximum cellular growth rate. Conclusions This in silico platform, designed for targeted searching of heterologous metabolic reactions, provides essential information for cell factory improvement.

  13. Oxantel pamoate-albendazole for Trichuris trichiura infection.

    Science.gov (United States)

    Speich, Benjamin; Ame, Shaali M; Ali, Said M; Alles, Rainer; Huwyler, Jörg; Hattendorf, Jan; Utzinger, Jürg; Albonico, Marco; Keiser, Jennifer

    2014-02-13

    Infections with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) are widespread and often occur concomitantly. These parasitic-worm infections are typically treated with albendazole or mebendazole, but both drugs show low efficacy against T. trichiura. Albendazole is the drug of choice against hookworm. In this double-blind trial conducted on Pemba Island, Tanzania, we randomly assigned children, 6 to 14 years of age, to receive one of four treatments: oxantel pamoate at a dose of 20 mg per kilogram of body weight, plus 400 mg of albendazole, administered on consecutive days; oxantel pamoate at a single dose of 20 mg per kilogram; albendazole at a single dose of 400 mg; or mebendazole at a single dose of 500 mg. We assessed the efficacy and safety profile of oxantel pamoate-albendazole when used in the treatment of T. trichiura infection (primary outcome) and concomitant soil-transmitted helminth infection (secondary outcome). Efficacy was determined by means of assessment of the cure rate and egg-reduction rate. Adverse events were assessed four times after treatment. Complete data were available for 458 children, of whom 450 were infected with T. trichiura, 443 with hookworm, and 293 with A. lumbricoides. The cure rate of T. trichiura infection was significantly higher with oxantel pamoate-albendazole than with mebendazole (31.2% vs. 11.8%, P=0.001), as was the egg-reduction rate (96.0% [95% confidence interval {CI}, 93.5 to 97.6] vs. 75.0% [95% CI, 64.2 to 82.0]). The cure rate with albendazole (2.6%) and the egg-reduction rate with albendazole (45.0%; 95% CI, 32.0 to 56.4) were significantly lower than the rates with mebendazole (P=0.02 for the comparison of cure rates). Oxantel pamoate had low efficacy against hookworm and A. lumbricoides. Adverse events (mainly mild) were reported by 30.9% of all children. Treatment with oxantel pamoate-albendazole resulted in higher cure and egg-reduction rates for T. trichiura infection

  14. Strain- and Dose-Dependent Reduction of Toxoplasma gondii Burden in Pigs Is Associated with Interferon-Gamma Production by CD8+ Lymphocytes in a Heterologous Challenge Model

    Directory of Open Access Journals (Sweden)

    Malgorzata Jennes

    2017-06-01

    Full Text Available Toxoplasma gondii is a worldwide prevalent parasite of humans and animals. The global infection burden exceeds yearly one million disability-adjusted life years (DALY's in infected individuals. Therefore, effective preventive measures should be taken to decrease the risk of infection in humans. Although human toxoplasmosis is predominantly foodborne by ingestion of tissue cysts in meat from domestic animals such as pigs, the incidence risk is difficult to estimate due to the lack of screening of animals for infection and insights in location and persistence of the parasite in the tissues. Hence, experimental infections in pigs can provide more information on the risk for zoonosis based on the parasite burden in meat products intended for human consumption and on the immune responses induced by infection. In the present study, homo- and heterologous infection experiments with two distinct T. gondii strains (IPB-LR and IPB-Gangji were performed. The humoral and cellular immune responses, the presence of viable parasites and the parasite load in edible meat samples were evaluated. In homologous infection experiments the parasite persistence was clearly strain-dependent and inversely correlated with the infection dose. The results strongly indicate a change in the amount of parasite DNA and viable cysts in porcine tissues over time. Heterologous challenge infections demonstrated that IPB-G strain could considerably reduce the parasite burden in the subsequent IPB-LR infection. A strong, however, not protective humoral response was observed against GRA7 and TLA antigens upon inoculation with both strains. The in vitro IFN-γ production by TLA-stimulated PBMCs was correlated with the infection dose and predominantly brought about by CD3+CD4−CD8αbright T-lymphocytes. The described adaptive cellular and humoral immune responses in pigs are in line with the induced or natural infections in mice and humans. Previous studies underscored the

  15. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010.

    Science.gov (United States)

    Pullan, Rachel L; Smith, Jennifer L; Jasrasaria, Rashmi; Brooker, Simon J

    2014-01-21

    Quantifying the burden of parasitic diseases in relation to other diseases and injuries requires reliable estimates of prevalence for each disease and an analytic framework within which to estimate attributable morbidity and mortality. Here we use data included in the Global Atlas of Helminth Infection to derive new global estimates of numbers infected with intestinal nematodes (soil-transmitted helminths, STH: Ascaris lumbricoides, Trichuris trichiura and the hookworms) and use disability-adjusted life years (DALYs) to estimate disease burden. Prevalence data for 6,091 locations in 118 countries were sourced and used to estimate age-stratified mean prevalence for sub-national administrative units via a combination of model-based geostatistics (for sub-Saharan Africa) and empirical approaches (for all other regions). Geographical variation in infection prevalence within these units was approximated using modelled logit-normal distributions, and numbers of individuals with infection intensities above given thresholds estimated for each species using negative binomial distributions and age-specific worm/egg burden thresholds. Finally, age-stratified prevalence estimates for each level of infection intensity were incorporated into the Global Burden of Disease Study 2010 analytic framework to estimate the global burden of morbidity and mortality associated with each STH infection. Globally, an estimated 438.9 million people (95% Credible Interval (CI), 406.3 - 480.2 million) were infected with hookworm in 2010, 819.0 million (95% CI, 771.7 - 891.6 million) with A. lumbricoides and 464.6 million (95% CI, 429.6 - 508.0 million) with T. trichiura. Of the 4.98 million years lived with disability (YLDs) attributable to STH, 65% were attributable to hookworm, 22% to A. lumbricoides and the remaining 13% to T. trichiura. The vast majority of STH infections (67%) and YLDs (68%) occurred in Asia. When considering YLDs relative to total populations at risk however, the burden

  16. Risk factors for helminth, malaria, and HIV infection in pregnancy in Entebbe, Uganda.

    Directory of Open Access Journals (Sweden)

    Patrick William Woodburn

    2009-06-01

    Full Text Available Infections during pregnancy may have serious consequences for both mother and baby. Assessment of risk factors for infections informs planning of interventions and analysis of the impact of infections on health outcomes.To describe risk factors for helminths, malaria and HIV in pregnant Ugandan women before intervention in a trial of de-worming in pregnancy.The trial recruited 2,507 pregnant women between April 2003 and November 2005. Participants were interviewed and blood and stool samples obtained; location of residence at enrolment was mapped. Demographic, socioeconomic, behavioral and other risk factors were modelled using logistic regression.There was a high prevalence of helminth, malaria and HIV infection, as previously reported. All helminths and malaria parasitemia were more common in younger women, and education was protective against every infection. Place of birth and/or tribe affected all helminths in a pattern consistent with the geographical distribution of helminth infections in Uganda. Four different geohelminths (hookworm, Trichuris, Ascaris and Trichostrongylus showed a downwards trend in prevalence during the enrolment period. There was a negative association between hookworm and HIV, and between hookworm and low CD4 count among HIV-positive women. Locally, high prevalence of schistosomiasis and HIV occurred in lakeshore communities.Interventions for helminths, malaria and HIV need to target young women both in and out of school. Antenatal interventions for malaria and HIV infection must continue to be promoted. Women originating from a high risk area for a helminth infection remain at high risk after migration to a lower-risk area, and vice versa, but overall, geohelminths seem to be becoming less common in this population. High risk populations, such as fishing communities, require directed effort against schistosomiasis and HIV infection.

  17. Rapid Re-Infection with Soil-Transmitted Helminths after Triple-Dose Albendazole Treatment of School-Aged Children in Yunnan, People's Republic of China

    Science.gov (United States)

    Yap, Peiling; Du, Zun-Wei; Wu, Fang-Wei; Jiang, Jin-Yong; Chen, Ran; Zhou, Xiao-Nong; Hattendorf, Jan; Utzinger, Jürg; Steinmann, Peter

    2013-01-01

    Post-treatment soil-transmitted helminth re-infection patterns were studied as part of a randomized controlled trial among school-aged children from an ethnic minority group in Yunnan province, People's Republic of China. Children with a soil-transmitted helminth infection (N = 194) were randomly assigned to triple-dose albendazole or placebo and their infection status monitored over a 6-month period using the Kato-Katz and Baermann techniques. Baseline prevalence of Trichuris trichiura, Ascaris lumbricoides, hookworm, and Strongyloides stercoralis were 94.5%, 93.3%, 61.3%, and 3.1%, respectively, with more than half of the participants harboring triple-species infections. For the intervention group (N = 99), the 1-month post-treatment cure rates were 96.7%, 91.5%, and 19.6% for hookworm, A. lumbricoides, and T. trichiura, respectively. Egg reduction rates were above 88% for all three species. Rapid re-infection with A. lumbricoides was observed: the prevalence 4 and 6 months post-treatment was 75.8% and 83.8%, respectively. Re-infection with hookworm and T. trichiura was considerably slower. PMID:23690551

  18. Rationally designed, heterologous S. cerevisiae transcripts expose novel expression determinants

    Science.gov (United States)

    Ben-Yehezkel, Tuval; Atar, Shimshi; Zur, Hadas; Diament, Alon; Goz, Eli; Marx, Tzipy; Cohen, Rafael; Dana, Alexandra; Feldman, Anna; Shapiro, Ehud; Tuller, Tamir

    2015-01-01

    Deducing generic causal relations between RNA transcript features and protein expression profiles from endogenous gene expression data remains a major unsolved problem in biology. The analysis of gene expression from heterologous genes contributes significantly to solving this problem, but has been heavily biased toward the study of the effect of 5′ transcript regions and to prokaryotes. Here, we employ a synthetic biology driven approach that systematically differentiates the effect of different regions of the transcript on gene expression up to 240 nucleotides into the ORF. This enabled us to discover new causal effects between features in previously unexplored regions of transcripts, and gene expression in natural regimes. We rationally designed, constructed, and analyzed 383 gene variants of the viral HRSVgp04 gene ORF, with multiple synonymous mutations at key positions along the transcript in the eukaryote S. cerevisiae. Our results show that a few silent mutations at the 5′UTR can have a dramatic effect of up to 15 fold change on protein levels, and that even synonymous mutations in positions more than 120 nucleotides downstream from the ORF 5′end can modulate protein levels up to 160%–300%. We demonstrate that the correlation between protein levels and folding energy increases with the significance of the level of selection of the latter in endogenous genes, reinforcing the notion that selection for folding strength in different parts of the ORF is related to translation regulation. Our measured protein abundance correlates notably(correlation up to r = 0.62 (p=0.0013)) with mean relative codon decoding times, based on ribosomal densities (Ribo-Seq) in endogenous genes, supporting the conjecture that translation elongation and adaptation to the tRNA pool can modify protein levels in a causal/direct manner. This report provides an improved understanding of transcript evolution, design principles of gene expression regulation, and suggests simple

  19. Comparison of heterologous xylose transporters in recombinant Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Hahn-Hägerdal Bärbel

    2010-03-01

    Full Text Available Abstract Background Baker's yeast (Saccharomyces cerevisiae has been engineered for xylose utilization to enable production of fuel ethanol from lignocellulose raw material. One unresolved challenge is that S. cerevisiae lacks a dedicated transport system for pentose sugars, which means that xylose is transported by non-specific Hxt transporters with comparatively low transport rate and affinity for xylose. Results In this study, we compared three heterologous xylose transporters that have recently been shown to improve xylose uptake under different experimental conditions. The transporters Gxf1, Sut1 and At5g59250 from Candida intermedia, Pichia stipitis and Arabidopsis thaliana, respectively, were expressed in isogenic strains of S. cerevisiae and the transport kinetics and utilization of xylose was evaluated. Expression of the Gxf1 and Sut1 transporters led to significantly increased affinity and transport rates of xylose. In batch cultivation at 4 g/L xylose concentration, improved transport kinetics led to a corresponding increase in xylose utilization, whereas no correlation could be demonstrated at xylose concentrations greater than 15 g/L. The relative contribution of native sugar transporters to the overall xylose transport capacity was also estimated during growth on glucose and xylose. Conclusions Kinetic characterization and aerobic batch cultivation of strains expressing the Gxf1, Sut1 and At5g59250 transporters showed a direct relationship between transport kinetics and xylose growth. The Gxf1 transporter had the highest transport capacity and the highest xylose growth rate, followed by the Sut1 transporter. The range in which transport controlled the growth rate was determined to between 0 and 15 g/L xylose. The role of catabolite repression in regulation of native transporters was also confirmed by the observation that xylose transport by native S. cerevisiae transporters increased significantly during cultivation in xylose and

  20. Predicting frequency distribution and influence of sociodemographic and behavioral risk factors of Schistosoma mansoni infection and analysis of co-infection with intestinal parasites

    Directory of Open Access Journals (Sweden)

    Carla V.V. Rollemberg

    2015-05-01

    Full Text Available Geospatial analysis was used to study the epidemiology of Schistosoma mansoni, intestinal parasites and co-infections in an area (Ilha das Flores in Sergipe, Brazil. We collected individually georeferenced sociodemographic, behavioral and parasitological data from 500 subjects, analyzed them by conventional statistics, and produced risk maps by Kernel estimation. The prevalence rates found were: S. mansoni (24.0%, Trichuris trichiura (54.8%, Ascaris lumbricoides (49.2%, Hookworm (17.6% and Entamoeba histolytica (7.0%. Only 59/500 (11.8% individuals did not present any of these infections, whereas 279/500 (55.8% were simultaneously infected by three or more parasites. We observed associations between S. mansoni infection and various variables such as male gender, being rice farmer or fisherman, low educational level, low income, water contact and drinking untreated water. The Kernel estimator indicated that high-risk areas coincide with the poorest regions of the villages as well as with the part of the villages without an adequate sewage system. We also noted associations between both A. lumbricoides and hookworm infections with low education and low income. A. lumbricoides infection and T. trichiura infection were both associated with drinking untreated water and residential open-air sewage. These findings call for an integrated approach to effectively control multiple parasitic infections.

  1. Influence of helminth infections on childhood nutritional status in lowland Bolivia.

    Science.gov (United States)

    Tanner, S; Leonard, W R; McDade, T W; Reyes-Garcia, V; Godoy, R; Huanca, T

    2009-01-01

    Infectious disease, such as diarrheal disease, respiratory infections, and parasitic infections, are an important source of nutritional and energetic stress in many populations. Inspired by the research and methodological innovations of A. Roberto Frisancho, this work considers the impact of childhood environment and local disease ecology on child health and nutritional patterns among an indigenous group in lowland Bolivia. Specifically, we examine the association between soil-transmitted helminth infection, especially hookworm species, and anthropometric markers of short- and long-term nutritional status. Fecal samples, anthropometric dimensions, and health interviews were collected for 92 children ranging in age from 2.0 to 10.9 years. Microscopic examination revealed high levels of parasitic infection, with 76% of children positive for hookworm species infections (77% of girls and 74% of boys). Less common infections included Ascaris lumbricoides, Trichurius trichiura, and Strongyloides stercoralis with only 15% of children positive for multiple-species infections. After adjusting for sex and age, no statistically significant associations were observed between helminth infections and the frequency of reported illness or anthropometric measures of nutritional status. These data demonstrate the difficulty of assessing nutritional impacts of endemic infections.

  2. Protection of dogs against canine heartworm infection 28?days after four monthly treatments with Advantage Multi? for Dogs

    OpenAIRE

    Bowman, Dwight D.; Grazette, Alyssa R.; Basel, Chris; Wang, Yingying; Hostetler, Joseph A.

    2016-01-01

    Background Monthly heartworm preventives are designed to protect dogs by killing heartworms acquired the month prior to their administration, and after treatment with most products, the drug levels rapidly dissipate to very low levels. Work with Advantage Multi? for Dogs (imidacloprid?+?moxidectin) topical solution showed protection against hookworm infection throughout the month after administration of several monthly doses suggesting that similar protection might occur with heartworms. This...

  3. haplotypes of hookworms (Ancylostoma)

    African Journals Online (AJOL)

    Melanie

    2012-01-26

    Jan 26, 2012 ... resulting tree, as well as their genetic distance from other samples .... E6. RTAYR1. 545. A. brasiliense. JQ083592. 18, 19. E7. RTAYR1. 545 ..... Traub RJ, Inpankaew T, Sutthikornchai C, Sukthana Y, Thompson RCA. (2008).

  4. Comparison of intestinal parasitic infection in newly arrived and resident workers in Qatar

    Directory of Open Access Journals (Sweden)

    Abu-Madi Marawan A

    2011-11-01

    Full Text Available Abstract Background The rapid growth of Qatar in the last two decades has been associated with an enormous expansion of building programs in its cities and in the provision of new service industries. This in turn has attracted a large influx of immigrant workers seeking employment in jobs associated with food handling, domestic service and the building industry. Many of these immigrants come from countries in the tropics and subtropics where intestinal parasitic infections are common. Methods We analyzed intestinal parasitic infections recorded in 2008 among immigrant and long-term resident workers in Doha city, Qatar (n = 1538. Stool examinations were carried out at the Hamad Medical Corporation and at the Medical Commission in Doha using standard procedures. Results Overall, 21.5% of subjects were infected with at least one of the species recorded (8 helminth and 4 protozoan species; the highest prevalence was for hookworms = 8.3% and there were strong regional effects on prevalence of helminths, with subjects from North East Africa and Nepal showing particularly high prevalence. Most helminths declined in prevalence in subjects that acquired residency status in Qatar, especially among female subjects, but there was a marked exception among male Nepalese workers, who continued to harbour helminth infections (notably hookworms after they became residents. Contrary to all other regional groups the prevalence of Giardia duodenalis was higher among Nepalese residents compared with new arrivals, while Blastocystis hominis infections were more common among residents of all regions, and especially among North East Africans. Conclusions Our analysis has identified male Nepalese workers as a particular risk group continuing to harbour hookworm infection and G. duodenalis as residents, and subjects from North East Africa are as particularly likely to acquire B. hominis infection after settling in the country. These conclusions have important

  5. Associations between mild-to-moderate anaemia in pregnancy and helminth, malaria and HIV infection in Entebbe, Uganda.

    Science.gov (United States)

    Muhangi, Lawrence; Woodburn, Patrick; Omara, Mildred; Omoding, Nicholas; Kizito, Dennison; Mpairwe, Harriet; Nabulime, Juliet; Ameke, Christine; Morison, Linda A; Elliott, Alison M

    2007-09-01

    It is suggested that helminths, particularly hookworm and schistosomiasis, may be important causes of anaemia in pregnancy. We assessed the associations between mild-to-moderate anaemia (haemoglobin >8.0 g/dl and pregnancy in Entebbe, Uganda. The prevalence of anaemia was 39.7%. The prevalence of hookworm was 44.5%, Mansonella perstans 21.3%, Schistosoma mansoni 18.3%, Strongyloides 12.3%, Trichuris 9.1%, Ascaris 2.3%, asymptomatic Plasmodium falciparum parasitaemia 10.9% and HIV 11.9%. Anaemia showed little association with the presence of any helminth, but showed a strong association with malaria (adjusted odds ratio (AOR) 3.22, 95% CI 2.43-4.26) and HIV (AOR 2.46, 95% CI 1.90-3.19). There was a weak association between anaemia and increasing hookworm infection intensity. Thus, although highly prevalent, helminths showed little association with mild-to-moderate anaemia in this population, but HIV and malaria both showed a strong association. This result may relate to relatively good nutrition and low helminth infection intensity. These findings are pertinent to estimating the disease burden of helminths and other infections in pregnancy. [Clinical Trial No. ISRCTN32849447].

  6. Yield improvement of heterologous peptides expressed in yps1-disrupted Saccharomyces cerevisiae strains.

    Science.gov (United States)

    Egel-Mitani; Andersen; Diers; Hach; Thim; Hastrup; Vad

    2000-06-01

    Heterologous protein expression levels in Saccharomyces cerevisiae fermentations are highly dependent on the susceptibility to endogenous yeast proteases. Small peptides, such as glucagon and glucagon-like-peptides (GLP-1 and GLP-2), featuring an open structure are particularly accessible for proteolytic degradation during fermentation. Therefore, homogeneous products cannot be obtained. The most sensitive residues are found at basic amino acid residues in the peptide sequence. These heterologous peptides are degraded mainly by the YPS1-encoded aspartic protease, yapsin1, when produced in the yeast. In this article, distinct degradation products were analyzed by HPLC and mass spectrometry, and high yield of the heterologous peptide production has been achieved by the disruption of the YPS1 gene (previously called YAP3). By this technique, high yield continuous fermentation of glucagon in S. cerevisiae is now possible.

  7. Protective efficacy of an inactivated Eurasian avian-like H1N1 swine influenza vaccine against homologous H1N1 and heterologous H1N1 and H1N2 viruses in mice.

    Science.gov (United States)

    Sui, Jinyu; Yang, Dawei; Qiao, Chuanling; Xu, Huiyang; Xu, Bangfeng; Wu, Yunpu; Yang, Huanliang; Chen, Yan; Chen, Hualan

    2016-07-19

    Eurasian avian-like H1N1 (EA H1N1) swine influenza viruses are prevalent in pigs in Europe and Asia, but occasionally cause human infection, which raises concern about their pandemic potential. Here, we produced a whole-virus inactivated vaccine with an EA H1N1 strain (A/swine/Guangxi/18/2011, SW/GX/18/11) and evaluated its efficacy against homologous H1N1 and heterologous H1N1 and H1N2 influenza viruses in mice. A strong humoral immune response, which we measured by hemagglutination inhibition (HI) and virus neutralization (VN), was induced in the vaccine-inoculated mice upon challenge. The inactivated SW/GX/18/11 vaccine provided complete protection against challenge with homologous SW/GX/18/11 virus in mice and provided effective protection against challenge with heterologous H1N1 and H1N2 viruses with distinctive genomic combinations. Our findings suggest that this EA H1N1 vaccine can provide protection against both homologous H1N1 and heterologous H1N1 or H1N2 virus infection. As such, it is an excellent vaccine candidate to prevent H1N1 swine influenza. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Seasonal influenza split vaccines confer partial cross-protection against heterologous influenza virus in ferrets when combined with the CAF01 adjuvant

    DEFF Research Database (Denmark)

    Christensen, Dennis; Christensen, Jan P.; Korsholm, Karen S.

    2018-01-01

    Influenza epidemics occur annually, and estimated 5-10% of the adult population and 20-30% of children will become ill from influenza infection. Seasonal vaccines primarily work through the induction of neutralizing antibodies against the principal surface antigen hemagglutinin (HA). This important...... role of HA-specific antibodies explains why previous pandemics have emerged when new HAs have appeared in circulating human viruses. It has long been recognized that influenza virus-specific CD4(+) T cells are important in protection from infection through direct effector mechanisms or by providing...... help to B cells and CD8(+) T cells. However, the seasonal influenza vaccine is poor at inducing CD4(+) T-cell responses and needs to be combined with an adjuvant facilitating this response. In this study, we applied the ferret model to investigate the cross-protective efficacy of a heterologous...

  9. METHOD FOR THE PRODUCTION OF HETEROLOGOUS POLYPEPTIDES IN TRANSFORMED YEAST CELLS

    DEFF Research Database (Denmark)

    2000-01-01

    The invention describes industrial fermentation of a $i(Saccharomyces) yeast species for production of a heterologous product encoded by a plasmid or DNA contained in said $i(Saccharomyces) yeast species with method utilizes the substrate more efficiently and without fermentative metabolism...... resulting in formation of ethanol and other unwanted primary products of fermentative activity whereby high yields of the heterologous product are obtained. The $i(Saccharomyces) yeast species is preferably a Crabtree negative $i(Saccharomyces species) in particular $i(Saccharomyces kluyveri)....

  10. Direct capture and heterologous expression of Salinispora natural product genes for the biosynthesis of enterocin.

    Science.gov (United States)

    Bonet, Bailey; Teufel, Robin; Crüsemann, Max; Ziemert, Nadine; Moore, Bradley S

    2015-03-27

    Heterologous expression of secondary metabolic pathways is a promising approach for the discovery and characterization of bioactive natural products. Herein we report the first heterologous expression of a natural product from the model marine actinomycete genus Salinispora. Using the recently developed method of yeast-mediated transformation-associated recombination for natural product gene clusters, we captured a type II polyketide synthase pathway from Salinispora pacifica with high homology to the enterocin pathway from Streptomyces maritimus and successfully produced enterocin in two different Streptomyces host strains. This result paves the way for the systematic interrogation of Salinispora's promising secondary metabolome.

  11. Helminth infections among people using wastewater and human excreta in peri-urban agriculture and aquaculture in Hanoi, Vietnam.

    Science.gov (United States)

    Do, Thuy Trang; Mølbak, Kåre; Phung, Dac Cam; Dalsgaard, Anders

    2007-12-01

    To assess the prevalence of helminth infections and their associated risks in a community using both wastewater and human excreta in agriculture and aquaculture. A cross-sectional study was conducted in a peri-urban area in Hanoi, Vietnam. Data on the demography, socioeconomics and sanitation were collected from a survey of 400 agricultural households. Parasitological examination for the eggs of Ascaris sp., Trichuris sp. and hookworm was performed on single stool specimens obtained from study household members' 15-70 years and 0-72 months of age. Of 807 stool samples collected from 620 adults and 187 children, 39% were infected with helminths. The prevalence of infections with Ascaris sp., Trichuris sp. and hookworm was 21.6%, 9.8% and 21.8%, respectively. Univariate and multivariate analyses showed that being an adult, female gender, living in a household without a latrine, excreta composted for less than 1 month and use of fresh human excreta were significantly associated with co-infection with all three helminths. Being an adult was an independent determinant for infections with individual helminths. The absence of a latrine and use of stored urine for irrigation were associated with an increased risk of Ascaris infection. Risk factors for Trichuris infection were inadequately composted excreta and year-round wastewater contact; risk factors for hookworm infection were female gender, household without a latrine and use of fresh human excreta. Wastewater exposure did not pose a major risk for helminth infection in this community. Instead, lack of sanitation facilities and use of fresh or inadequately composted human excreta in agriculture were important risk factors.

  12. Co-endemicity of Plasmodium falciparum and Intestinal Helminths Infection in School Age Children in Rural Communities of Kwara State Nigeria

    Science.gov (United States)

    Adedoja, Ayodele; Tijani, Bukola Deborah; Akanbi, Ajibola A.; Ojurongbe, Taiwo A.; Adeyeba, Oluwaseyi A.; Ojurongbe, Olusola

    2015-01-01

    Background Malaria and intestinal helminths co-infection are major public health problems particularly among school age children in Nigeria. However the magnitude and possible interactions of these infections remain poorly understood. This study determined the prevalence, impact and possible interaction of Plasmodium falciparum and intestinal helminths co-infection among school children in rural communities of Kwara State, Nigeria. Methods Blood, urine and stool samples were collected from 1017 primary school pupils of ages 4–15 years. Stool samples were processed using both Kato-Katz and formol-ether concentration techniques and microscopically examined for intestinal helminths infection. Urine samples were analyzed using sedimentation method for Schistosoma haematobium. Plasmodium falciparum was confirmed by microscopy using thick and thin blood films methods and packed cell volume (PCV) was determined using hematocrit reader. Univariate analysis and chi-square statistical tests were used to analyze the data. Results Overall, 61.2% of all school children had at least an infection of either P. falciparum, S. haematobium, or intestinal helminth. S. haematobium accounted for the largest proportion (44.4%) of a single infection followed by P. falciparum (20.6%). The prevalence of malaria and helminth co-infection in the study was 14.4%. Four species of intestinal helminths were recovered from the stool samples and these were hookworm (22.5%), Hymenolepis species (9.8%), Schistosoma mansoni (2.9%) and Enterobius vermicularis (0.6%). The mean densities of P. falciparum in children co-infected with S. haematobium and hookworm were higher compared to those infected with P. falciparum only though not statistically significant (p = 0.062). The age distribution of both S. haematobium (p = 0.049) and hookworm (p = 0.034) infected children were statistically significant with the older age group (10–15 years) recording the highest prevalence of 47.2% and 25% respectively

  13. Height, zinc and soil-transmitted helminth infections in schoolchildren

    DEFF Research Database (Denmark)

    de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim

    2015-01-01

    Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data...... on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris...... trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children...

  14. Heterologous Production and Yield Improvement of Epothilones in Burkholderiales Strain DSM 7029.

    Science.gov (United States)

    Bian, Xiaoying; Tang, Biao; Yu, Yucong; Tu, Qiang; Gross, Frank; Wang, Hailong; Li, Aiying; Fu, Jun; Shen, Yuemao; Li, Yue-Zhong; Stewart, A Francis; Zhao, Guoping; Ding, Xiaoming; Müller, Rolf; Zhang, Youming

    2017-07-21

    The cloning of microbial natural product biosynthetic gene clusters and their heterologous expression in a suitable host have proven to be a feasible approach to improve the yield of valuable natural products and to begin mining cryptic natural products in microorganisms. Myxobacteria are a prolific source of novel bioactive natural products with only limited choices of heterologous hosts that have been exploited. Here, we describe the use of Burkholderiales strain DSM 7029 as a potential heterologous host for the functional expression of myxobacterial secondary metabolites. Using a newly established electroporation procedure, the 56 kb epothilone biosynthetic gene cluster from the myxobacterium Sorangium cellulosum was introduced into the chromosome of strain DSM 7029 by transposition. Production of epothilones A, B, C, and D was detected despite their yields being low. Optimization of the medium, introduction of the exogenous methylmalonyl-CoA biosynthetic pathway, and overexpression of rare tRNA genes resulted in an approximately 75-fold increase in the total yields of epothilones to 307 μg L -1 . These results show that strain DSM 7029 has the potential to produce epothilones with reasonable titers and might be a broadly applicable host for the heterologous expression of other myxobacterial polyketide synthases and nonribosomal peptide synthetases, expediting the process of genome mining.

  15. A novel platform for heterologous gene expression in Trichoderma reesei (Teleomorph Hypocrea jecorina)

    DEFF Research Database (Denmark)

    Jørgensen, Mikael Skaanning; Skovlund, Dominique Aubert; Johannesen, Pia Francke

    2014-01-01

    ABSTRACT: BACKGROUND: The industrially applied filamentous fungus Trichoderma reesei has received substantial interest due to its highly efficient synthesis apparatus of cellulytic enzymes. However, the production of heterologous enzymes in T. reesei still remains low mainly due to lack of tools...

  16. Heterologous expression of the Arabidopsis etr1-1 allele inhibits the senescence of carnation flowers

    NARCIS (Netherlands)

    Bovy, A.G.; Angenent, G.C.; Dons, H.J.M.; Altvorst, van A.

    1999-01-01

    The Arabidopsis thaliana etr1-1 allele, capable of conferring ethylene insensitivity in a heterologous host, was introduced into transgenic carnation plants. This gene was expressed under control of either its own promoter, the constitutive CaMV 35S promoter or the flower-specific petunia FBP1

  17. Heterologous humoral immune response in patients treated with human growth hormone from different sources

    International Nuclear Information System (INIS)

    Cardoso, A.I.; Llera, A.S.; Iacono, R.F.

    1993-01-01

    The existence of homologous anti-human growth hormone (anti-hGH) and heterologous anti-bovine growth hormone (anti-bGH) humoral immune responses in hypopituitary patients under hGH therapy has been reported previously. In order to study the influence of the hormone source, both responses were compared by radiobinding assays performed with [ 125 I]hGH or [ 125 I]bGH as tracers. 57 hypopituitary patients treated with extractive hGH, recombinant methionyl hGH or authentic recombinant hGH were studied. A very low incidence of heterologous antibodies was found in patients under recombinant hGH therapy, contrary to the high incidence observed in patients treated with extractive hGH preparations. In addition, immunochemical studies performed with a synthetic peptide (hGH 44-128) indicated that this peptide exhibited, in the anti-bGH/[ 125 I]bGH radioimmunoassay system, higher reactivity than the native hGH, suggesting that such fragment resembled an altered conformation of the hormone. The high heterologous response elicited only by the extractive hGH along with the behaviour of the hGH 44-128 fragment supports the fact that the extraction and purification procedures in extractive preparations may alter slightly the structure of the hGH molecule and trigger a heterologous immune response. 16 refs., 4 figs., 1 tab

  18. Heterologous humoral immune response in patients treated with human growth hormone from different sources

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, A.I.; Llera, A.S.; Iacono, R.F. (and others) (Inst. de Estudios de la Inmunidad Humoral, Buenos Aires (Argentina))

    1993-07-01

    The existence of homologous anti-human growth hormone (anti-hGH) and heterologous anti-bovine growth hormone (anti-bGH) humoral immune responses in hypopituitary patients under hGH therapy has been reported previously. In order to study the influence of the hormone source, both responses were compared by radiobinding assays performed with [[sup 125]I]hGH or [[sup 125]I]bGH as tracers. 57 hypopituitary patients treated with extractive hGH, recombinant methionyl hGH or authentic recombinant hGH were studied. A very low incidence of heterologous antibodies was found in patients under recombinant hGH therapy, contrary to the high incidence observed in patients treated with extractive hGH preparations. In addition, immunochemical studies performed with a synthetic peptide (hGH 44-128) indicated that this peptide exhibited, in the anti-bGH/[[sup 125]I]bGH radioimmunoassay system, higher reactivity than the native hGH, suggesting that such fragment resembled an altered conformation of the hormone. The high heterologous response elicited only by the extractive hGH along with the behaviour of the hGH 44-128 fragment supports the fact that the extraction and purification procedures in extractive preparations may alter slightly the structure of the hGH molecule and trigger a heterologous immune response. 16 refs., 4 figs., 1 tab.

  19. Heterologous Prime-Boost Immunizations with a Virosomal and an Alphavirus Replicon Vaccine

    NARCIS (Netherlands)

    Walczak, Mateusz; de Mare, Arjan; Riezebos-Brilman, Annelies; Regts, Joke; Hoogeboom, Baukje-Nynke; Visser, Jeroen T.; Fiedler, Marc; Jansen-Duerr, Pidder; van der Zee, Ate G. J.; Nijman, Hans W.; Wilschut, Jan; Daemen, Toos

    2011-01-01

    Heterologous prime-boost immunization strategies in general establish higher frequencies of antigen-specific T lymphocytes than homologous prime-boost protocols or single immunizations. We developed virosomes and recombinant Semliki Forest virus (rSFV) as antigen delivery systems, each capable of

  20. ANTIGENIC RELATEDNESS OF SELECTED FLAVIVIRUSES: STUDY WITH HOMOLOGOUS AND HETEROLOGOUS IMMUNE MOUSE ASCITIC FLUIDS

    Directory of Open Access Journals (Sweden)

    S.S. BABA

    1998-11-01

    Full Text Available The antigenic relationship of 9 flaviviruses, Yellow fever (YF , Wesselsbron (WSL , Uganda S (UGS , Potiskum (POT, West Nile (WN , Banzi (BAN , Zika (ZK , Dengue type 1 (DEN-1 and Dengue type 2 (DEN-2, was assessed by cross-haemagglutination-inhibition (Cross-HI and cross-complement fixation (Cross-CF reactions between each of the viruses and their homologous immune mouse ascitic fluids. Titre ratios were calculated using the heterologous and homologous titres. Cross-CF reactions revealed wider antigenic variations among viruses than Cross-HI reactions. There was no significant antigenic variation between WSL, POT and YF viruses using either of those methods. However, definite differences in antigenicity were observed between them and UGS, BAN and ZK viruses. There were no significant differences between UGS, BAN and ZK or between DEN-1 and DEN-2. The serological relationship among flaviviruses is important in establishing diagnosis and epidemiology of these infections in Africa.A relação antigênica de 9 Flavivirus, Febre amarela (YF, Wesselsbron (WSL, Uganda S (UGS, Potiskum (POT, West Nile (WN, Banzi (BAN, Zika (ZK, Dengue tipo 1 (DEN-1 e Dengue tipo2 (DEN-2, foi avaliada por reação de inibição da hemaglutinação cruzada (cross-HI e reação de fixação do complemento cruzada (Cross-CF entre cada um dos virus e seu fluido ascítico homólogo em camundongos. Médias de títulos foram calculadas usando os títulos heterólogos e homólogos. Reações cruzadas CF revelaram maiores variações antigênicas entre virus do que reações cruzadas HI. Não houve variação antigênica significativa entre virus WSL, POT e YF usando cada um dos métodos. Todavia, diferenças definidas da antigenicidade foram observadas entre eles e os vírus UGS, BAN e ZK. Não existiram diferenças significativas entre UGS, BAN e ZK ou entre DEN-1 e DEN-2. A relação sorológica entre Flavivirus é importante para se estabelecer o diagnóstico e a

  1. Vaccination with Recombinant Parainfluenza Virus 5 Expressing Neuraminidase Protects against Homologous and Heterologous Influenza Virus Challenge.

    Science.gov (United States)

    Mooney, Alaina J; Gabbard, Jon D; Li, Zhuo; Dlugolenski, Daniel A; Johnson, Scott K; Tripp, Ralph A; He, Biao; Tompkins, S Mark

    2017-12-01

    Seasonal human influenza virus continues to cause morbidity and mortality annually, and highly pathogenic avian influenza (HPAI) viruses along with other emerging influenza viruses continue to pose pandemic threats. Vaccination is considered the most effective measure for controlling influenza; however, current strategies rely on a precise vaccine match with currently circulating virus strains for efficacy, requiring constant surveillance and regular development of matched vaccines. Current vaccines focus on eliciting specific antibody responses against the hemagglutinin (HA) surface glycoprotein; however, the diversity of HAs across species and antigenic drift of circulating strains enable the evasion of virus-inhibiting antibody responses, resulting in vaccine failure. The neuraminidase (NA) surface glycoprotein, while diverse, has a conserved enzymatic site and presents an appealing target for priming broadly effective antibody responses. Here we show that vaccination with parainfluenza virus 5 (PIV5), a promising live viral vector expressing NA from avian (H5N1) or pandemic (H1N1) influenza virus, elicited NA-specific antibody and T cell responses, which conferred protection against homologous and heterologous influenza virus challenges. Vaccination with PIV5-N1 NA provided cross-protection against challenge with a heterosubtypic (H3N2) virus. Experiments using antibody transfer indicate that antibodies to NA have an important role in protection. These findings indicate that PIV5 expressing NA may be effective as a broadly protective vaccine against seasonal influenza and emerging pandemic threats. IMPORTANCE Seasonal influenza viruses cause considerable morbidity and mortality annually, while emerging viruses pose potential pandemic threats. Currently licensed influenza virus vaccines rely on the antigenic match of hemagglutinin (HA) for vaccine strain selection, and most vaccines rely on HA inhibition titers to determine efficacy, despite the growing

  2. The interrelation between intestinal parasites and latent TB infections among newly resettled refugees in Texas.

    Science.gov (United States)

    Board, Amy R; Suzuki, Sumihiro

    2016-01-01

    Previous research has documented that parasite infection may increase vulnerability to TB among certain at risk populations. The purpose of this study was to identify whether an association exists between latent tuberculosis infection (LTBI) and intestinal parasite infection among newly resettled refugees in Texas while controlling for additional effects of region of origin, age and sex. Data for all refugees screened for both TB and intestinal parasites between January 2010 and mid-October 2013 were obtained from the Texas Refugee Health Screening Program and were analyzed using logistic regression. A total of 9860 refugees were included. In multivariable logistic regression analysis, pathogenic and non-pathogenic intestinal parasite infections yielded statistically significant reduced odds of LTBI. However, when individual parasite species were analyzed, hookworm infection indicated statistically significant increased odds of LTBI (OR 1.674, CI: 1.126-2.488). A positive association exists between hookworm infection and LTBI in newly arrived refugees to Texas. More research is needed to assess the nature and extent of these associations. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Helminth infections and practice of prevention and control measures among pregnant women attending antenatal care at Anbesame health center, Northwest Ethiopia.

    Science.gov (United States)

    Shiferaw, Melashu Balew; Zegeye, Amtatachew Moges; Mengistu, Agmas Dessalegn

    2017-07-12

    Helminth infections have a terrible impact on child growth and development, and harm pregnant women. Regular treatment and long term preventive interventions are important measures to break the transmission routes. Hence, identifying the status of helminth infection and practices of prevention and control measures among pregnant women is important in different geographical areas of Ethiopia including our setting. A cross-sectional study was conducted on 180 pregnant women from March to June, 2015. About 2 g of stool was collected and examined to identify helminth infections. Proportions and risk factors of helminth infections were calculated using SPSS version 20. Among the total 180 study participants, 38 (21.1% [95% CI 15.2-27.0%]) pregnant women had helminth infections. Hookworm and Schistosoma mansoni were the only identified helminth species. Thirty-six (20.0% [95% CI 14.3-25.7%]) and 4 (2.2% [95% CI 0.2-4.2%]) pregnant women had hookworm and S. mansoni infections, respectively. Of which, double infection (hookworm and S. mansoni) was found in two pregnant women. Only 32 (17.8%) pregnant women had proper hand wash practice after toilet, 48 (26.7%) drank treated water, and 40 (22.2%) wore shoes regularly. Those pregnant women who did not take albendazole or mebendazole dewormers (AOR 3.57; 95% CI 1.19-10.69; P 0.023) were more infected from helminth infections. This study showed that there was a high intestinal helminth infection among pregnant women, and low practice of prevention and control measures. Thus, prevention and control measures should be strengthened in the setting.

  4. Heterologous expression of Streptococcus mutans Cnm in Lactococcus lactis promotes intracellular invasion, adhesion to human cardiac tissues and virulence.

    Science.gov (United States)

    Freires, Irlan A; Avilés-Reyes, Alejandro; Kitten, Todd; Simpson-Haidaris, P J; Swartz, Michael; Knight, Peter A; Rosalen, Pedro L; Lemos, José A; Abranches, Jacqueline

    2017-01-02

    In S. mutans, the expression of the surface glycoprotein Cnm mediates binding to extracellular matrix proteins, endothelial cell invasion and virulence in the Galleria mellonella invertebrate model. To further characterize Cnm as a virulence factor, the cnm gene from S. mutans strain OMZ175 was expressed in the non-pathogenic Lactococcus lactis NZ9800 using a nisin-inducible system. Despite the absence of the machinery necessary for Cnm glycosylation, Western blot and immunofluorescence microscopy analyses demonstrated that Cnm was effectively expressed and translocated to the cell wall of L. lactis. Similar to S. mutans, expression of Cnm in L. lactis enabled robust binding to collagen and laminin, invasion of human coronary artery endothelial cells and increased virulence in G. mellonella. Using an ex vivo human heart tissue colonization model, we showed that Cnm-positive strains of either S. mutans or L. lactis outcompete their Cnm-negative counterparts for tissue colonization. Finally, Cnm expression facilitated L. lactis adhesion and colonization in a rabbit model of infective endocarditis. Collectively, our results provide unequivocal evidence that binding to extracellular matrices mediated by Cnm is an important virulence attribute of S. mutans and confirm the usefulness of the L. lactis heterologous system for further characterization of bacterial virulence factors.

  5. Exposure to Sarcocystis spp. in horses from Spain determined by Western blot analysis using Sarcocystis neurona merozoites as heterologous antigen.

    Science.gov (United States)

    Arias, M; Yeargan, M; Francisco, I; Dangoudoubiyam, S; Becerra, P; Francisco, R; Sánchez-Andrade, R; Paz-Silva, A; Howe, D K

    2012-04-30

    Horses serve as an intermediate host for several species of Sarcocystis, all of which utilize canids as the definitive host. Sarcocystis spp. infection and formation of latent sarcocysts in horses often appears to be subclinical, but morbidity can occur, especially when the parasite burden is large. A serological survey was conducted to determine the presence of antibodies against Sarcocystis spp. in seemingly healthy horses from the Galicia region of Spain. Western blot analyses using Sarcocystis neurona merozoites as heterologous antigen suggested greater than 80% seroprevalance of Sarcocystis spp. in a sample set of 138 horses. The serum samples were further tested with enzyme-linked immunosorbent assays (ELISAs) based on recombinant S. neurona-specific surface antigens (rSnSAGs). As expected for horses from the Eastern Hemisphere, less than 4% of the serum samples were positive when analyzed with either the rSnSAG2 or the rSnSAG4/3 ELISAs. An additional 246 horses were tested using the rSnSAG2 ELISA, which revealed that less than 3% of the 384 samples were seropositive. Collectively, the results of this serologic study suggested that a large proportion of horses from this region of Spain are exposed to Sarcocystis spp. Furthermore, the anti-Sarcocystis seroreactivity in these European horses could be clearly distinguished from anti-S. neurona antibodies using the rSnSAG2 and rSnSAG4/3 ELISAs. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Heterologous expression of pikromycin biosynthetic gene cluster using Streptomyces artificial chromosome system.

    Science.gov (United States)

    Pyeon, Hye-Rim; Nah, Hee-Ju; Kang, Seung-Hoon; Choi, Si-Sun; Kim, Eung-Soo

    2017-05-31

    Heterologous expression of biosynthetic gene clusters of natural microbial products has become an essential strategy for titer improvement and pathway engineering of various potentially-valuable natural products. A Streptomyces artificial chromosomal conjugation vector, pSBAC, was previously successfully applied for precise cloning and tandem integration of a large polyketide tautomycetin (TMC) biosynthetic gene cluster (Nah et al. in Microb Cell Fact 14(1):1, 2015), implying that this strategy could be employed to develop a custom overexpression scheme of natural product pathway clusters present in actinomycetes. To validate the pSBAC system as a generally-applicable heterologous overexpression system for a large-sized polyketide biosynthetic gene cluster in Streptomyces, another model polyketide compound, the pikromycin biosynthetic gene cluster, was preciously cloned and heterologously expressed using the pSBAC system. A unique HindIII restriction site was precisely inserted at one of the border regions of the pikromycin biosynthetic gene cluster within the chromosome of Streptomyces venezuelae, followed by site-specific recombination of pSBAC into the flanking region of the pikromycin gene cluster. Unlike the previous cloning process, one HindIII site integration step was skipped through pSBAC modification. pPik001, a pSBAC containing the pikromycin biosynthetic gene cluster, was directly introduced into two heterologous hosts, Streptomyces lividans and Streptomyces coelicolor, resulting in the production of 10-deoxymethynolide, a major pikromycin derivative. When two entire pikromycin biosynthetic gene clusters were tandemly introduced into the S. lividans chromosome, overproduction of 10-deoxymethynolide and the presence of pikromycin, which was previously not detected, were both confirmed. Moreover, comparative qRT-PCR results confirmed that the transcription of pikromycin biosynthetic genes was significantly upregulated in S. lividans containing tandem

  7. Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits

    International Nuclear Information System (INIS)

    Freitas, S.H.; Doria, R.G.S.; Mendonca, F.S.; Santos, M.D.; Moreira, R.; Simoes, R.S.; Camargo, L.M.; Simoes, M.J.; Marques, A.T.C.

    2012-01-01

    A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects. (author)

  8. Geohelminth Infections and Nutritional Status of Preschool Aged Children in a Periurban Settlement of Ogun State

    Directory of Open Access Journals (Sweden)

    O. O. Omitola

    2016-01-01

    Full Text Available This study assessed the geohelminth and nutritional status of preschoolers in a periurban community of Ogun state. Fresh stool specimens were collected for laboratory analysis, processed using ether concentration method, and examined under the microscope for geohelminth ova. Demographic characteristics and daily nutrient intake of children were subjectively assessed during an interview session with parents, following anthropometric data collection. Data obtained were analysed using a statistical software for Windows. Nutritional indicators such as underweight, stunting, and wasting were computed from anthropometric data. Results showed an overall prevalence of 39.2% and 12.4% for Ascariasis and Hookworm infection, respectively, with no significant difference (P>0.05 between the sexes. Prevalence of nutritional indicators was 52.6%, 35.1%, 34.0%, and 9.3% for underweight, stunting, wasting, and thinness conditions, respectively. A good proportion of the malnourished preschoolers were free of Ascaris infection but infected with Hookworm parasite. The adverse effect of geohelminth infection cannot still be ignored in impaired growth, reduced survival, poor development, and cognitive performance of preschoolers. Therefore promotion of adequate health education program on measures of preventing geohelminth infections is needed.

  9. TLR1/2 activation during heterologous prime-boost vaccination (DNA-MVA enhances CD8+ T Cell responses providing protection against Leishmania (Viannia.

    Directory of Open Access Journals (Sweden)

    Asha Jayakumar

    2011-06-01

    Full Text Available Leishmania (Viannia parasites present particular challenges, as human and murine immune responses to infection are distinct from other Leishmania species, indicating a unique interaction with the host. Further, vaccination studies utilizing small animal models indicate that modalities and antigens that prevent infection by other Leishmania species are generally not protective.Using a newly developed mouse model of chronic L. (Viannia panamensis infection and the heterologous DNA prime - modified vaccinia virus Ankara (MVA boost vaccination modality, we examined whether the conserved vaccine candidate antigen tryparedoxin peroxidase (TRYP could provide protection against infection/disease.Heterologous prime - boost (DNA/MVA vaccination utilizing TRYP antigen can provide protection against disease caused by L. (V. panamensis. However, protection is dependent on modulating the innate immune response using the TLR1/2 agonist Pam3CSK4 during DNA priming. Prime-boost vaccination using DNA alone fails to protect. Prior to infection protectively vaccinated mice exhibit augmented CD4 and CD8 IFNγ and memory responses as well as decreased IL-10 and IL-13 responses. IL-13 and IL-10 have been shown to be independently critical for disease in this model. CD8 T cells have an essential role in mediating host defense, as CD8 depletion reversed protection in the vaccinated mice; vaccinated mice depleted of CD4 T cells remained protected. Hence, vaccine-induced protection is dependent upon TLR1/2 activation instructing the generation of antigen specific CD8 cells and restricting IL-13 and IL-10 responses.Given the general effectiveness of prime-boost vaccination, the recalcitrance of Leishmania (Viannia to vaccine approaches effective against other species of Leishmania is again evident. However, prime-boost vaccination modality can with modulation induce protective responses, indicating that the delivery system is critical. Moreover, these results suggest that

  10. Heterologous prime-boost vaccination with DNA and MVA vaccines, expressing HIV-1 subtype C mosaic Gag virus-like particles, is highly immunogenic in mice.

    Directory of Open Access Journals (Sweden)

    Ros Chapman

    Full Text Available In an effort to make affordable vaccines suitable for the regions most affected by HIV-1, we have constructed stable vaccines that express an HIV-1 subtype C mosaic Gag immunogen (BCG-GagM, MVA-GagM and DNA-GagM. Mosaic immunogens have been designed to address the tremendous diversity of this virus. Here we have shown that GagM buds from cells infected and transfected with MVA-GagM and DNA-GagM respectively and forms virus-like particles. Previously we showed that a BCG-GagM prime MVA-GagM boost generated strong cellular immune responses in mice. In this study immune responses to the DNA-GagM and MVA-GagM vaccines were evaluated in homologous and heterologous prime-boost vaccinations. The DNA homologous prime boost vaccination elicited predominantly CD8+ T cells while the homologous MVA vaccination induced predominantly CD4+ T cells. A heterologous DNA-GagM prime MVA-GagM boost induced strong, more balanced Gag CD8+ and CD4+ T cell responses and that were predominantly of an effector memory phenotype. The immunogenicity of the mosaic Gag (GagM was compared to a naturally occurring subtype C Gag (GagN using a DNA homologous vaccination regimen. DNA-GagN expresses a natural Gag with a sequence that was closest to the consensus sequence of subtype C viruses sampled in South Africa. DNA-GagM homologous vaccination induced cumulative HIV-1 Gag-specific IFN-γ ELISPOT responses that were 6.5-fold higher than those induced by the DNA-GagN vaccination. Similarly, DNA-GagM vaccination generated 7-fold higher levels of cytokine-positive CD8+ T cells than DNA-GagN, indicating that this subtype C mosaic Gag elicits far more potent immune responses than a consensus-type Gag. Cells transfected and infected with DNA-GagM and MVA-GagM respectively, expressed high levels of GagM and produced budding virus-like particles. Our data indicates that a heterologous prime boost regimen using DNA and MVA vaccines expressing HIV-1 subtype C mosaic Gag is highly

  11. AFSC/NMML/CCEP: Hookworm Intensity of Infection in California sea lion and Northern Fur Seal Pups in California, 1996 through 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — There are various causes of mortality for California sea lion (Zalophus californianus) and northern fur seal (Callorhinus ursinus) pups. This dataset contains...

  12. Profiling Nonrecipients of Mass Drug Administration for Schistosomiasis and Hookworm Infections: A Comprehensive Analysis of Praziquantel and Albendazole Coverage in Community-Directed Treatment in Uganda

    NARCIS (Netherlands)

    Chami, G.; Kontoleon, Andreas A.; Bulte, E.H.; Fenwick, Alan

    2016-01-01

    Background. Repeated mass drug administration (MDA) with preventive chemotherapies is the mainstay of morbidity control for schistosomiasis and soil-transmitted helminths, yet the World Health Organization recently reported that less than one-third of individuals who required preventive

  13. Profiling Nonrecipients of Mass Drug Administration for Schistosomiasis and Hookworm Infections : A Comprehensive Analysis of Praziquantel and Albendazole Coverage in Community-Directed Treatment in Uganda

    NARCIS (Netherlands)

    Chami, Goylette F.; Kontoleon, Andreas A.; Bulte, Erwin; Fenwick, Alan; Kabatereine, Narcis B.; Tukahebwa, Edridah M.; Dunne, David W.

    2016-01-01

    Background. Repeated mass drug administration (MDA) with preventive chemotherapies is the mainstay of morbidity control for schistosomiasis and soil-transmitted helminths, yet the World Health Organization recently reported that less than one-third of individuals who required preventive

  14. A new maltose-inducible high-performance heterologous expression system in Bacillus subtilis.

    Science.gov (United States)

    Yue, Jie; Fu, Gang; Zhang, Dawei; Wen, Jianping

    2017-08-01

    To improve heterologous proteins production, we constructed a maltose-inducible expression system in Bacillus subtilis. An expression system based on the promoter for maltose utilization constructed in B. subtilis. Successively, to improve the performance of the P malA -derived system, mutagenesis was employed by gradually shortening the length of P malA promoter and altering the spacing between the predicted MalR binding site and the -35 region. Furthermore, deletion of the maltose utilization genes (malL and yvdK) improved the P malA promoter activity. Finally, using this efficient maltose-inducible expression system, we enhanced the production of luciferase and D-aminoacylase, compared with the P hpaII system. A maltose-inducible expression system was constructed and evaluated. It could be used for high level expression of heterologous proteins production.

  15. Heterologous surface display on lactic acid bacteria: non-GMO alternative?

    Science.gov (United States)

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-01-01

    Lactic acid bacteria (LAB) are food-grade hosts for surface display with potential applications in food and therapy. Alternative approaches to surface display on LAB would avoid the use of recombinant DNA technology and genetically-modified organism (GMO)-related regulatory requirements. Non-covalent surface display of proteins can be achieved by fusing them to various cell-wall binding domains, of which the Lysine motif domain (LysM) is particularly well studied. Fusion proteins have been isolated from recombinant bacteria or from their growth medium and displayed on unmodified bacteria, enabling heterologous surface display. This was demonstrated on non-viable cells devoid of protein content, termed bacteria-like particles, and on various species of genus Lactobacillus. Of the latter, Lactobacillus salivarius ATCC 11741 was recently shown to be particularly amenable for LysM-mediated display. Possible regulatory implications of heterologous surface display are discussed, particularly those relevant for the European Union.

  16. Urothelial carcinoma of urinary bladder with exclusive heterologous component of epithelioid rhabdomyosarcoma at metastatic site.

    Science.gov (United States)

    Agarwal, Poojan; Pasricha, Sunil; Gupta, Gurudutt; Sharma, Anila; Mehta, Anurag

    2018-01-01

    Urothelial carcinoma of urinary bladder with divergent differentiation into rhabdomyosarcoma (RMS) is an extremely uncommon aggressive phenomenon. We present a case of a 74-year-old male with bladder carcinoma which metastasized to the abdominal wall as epithelioid RMS. To the best knowledge of our literature searches, an oligometastasis of exclusive heterologous component has not been described before. The clinical, radiological, and immunohistochemistry profile of the patient supported the monoclonal nature of the tumor.

  17. Construction of a system for heterologous production of carbonic anhydrase from Plasmodium falciparum in Pichia pastoris

    OpenAIRE

    Gullberg, Erik

    2008-01-01

    Malaria is one of the biggest current global health problems, and with the increasing occurance of drug resistant Plasmodium falciparum strains, there is an urgent need for new antimalarial drugs. Given the important role of carbonic anhydrase in Plasmodium falciparum (PfCA), it is a potential novel drug target. Heterologous expression of malaria proteins is problematic due to the unusual codon usage of the Plasmodium genome, so to overcome this problem a synthetic PfCA gene was designed, opt...

  18. The K Domain Mediates Homologous and Heterologous Interactions Between FLC and SVP Proteins of Brassica juncea

    Directory of Open Access Journals (Sweden)

    Ma Guanpeng

    2015-07-01

    Full Text Available The transcription factors FLOWERING LOCUS C (FLC and SHORT VEGETATIVE PHASE (SVP can interact to form homologous and heterologous protein complexes that regulate flowering time in Brassica juncea Coss. (Mustard.Previous studies showed that protein interactions were mediated by the K domain, which contains the subdomains K1, K2 and K3. However, it remains unknown how the subdomains mediate the interactions between FLC and SVP. In the present study, we constructed several mutants of subdomains K1–K3 and investigated the mechanisms involved in the heterologous interaction of BjFLC/BjSVP and in the homologous interaction of BjFLC/BjFLC or BjSVP/BjSVP. Yeast two-hybrid and β-Galactosidase activity assays showed that the 19 amino acids of the K1 subdomain in BjSVP and the 17 amino acids of the K1 subdomain in BjFLC were functional subdomains that interact with each other to mediate hetero-dimerization. The heterologous interaction was enhanced by the K2 subdomain of BjSVP protein, but weakened by its interhelical domain L2. The heterologous interaction was also enhanced by the K2 subdomain of BjFLC protein, but weakened by its K3 subdomain. The homologous interaction of BjSVP was mediated by the full K-domain. However, the homologous interaction of BjFLC was regulated only by its K1 and weakened by its K2 and K3 subdomains. The results provided new insights into the interactions between FLC and SVP, which will be valuable for further studies on the molecular regulation mechanisms of the regulation of flowering time in B. juncea and other Brassicaceae.

  19. Spatial organization of heterologous metabolic system in vivo based on TALE.

    Science.gov (United States)

    Zhu, Lv-yun; Qiu, Xin-Yuan; Zhu, Ling-Yun; Wu, Xiao-Min; Zhang, Yuan; Zhu, Qian-Hui; Fan, Dong-Yu; Zhu, Chu-Shu; Zhang, Dong-Yi

    2016-05-17

    For years, prokaryotic hosts have been widely applied in bio-engineering. However, the confined in vivo enzyme clustering of heterologous metabolic pathways in these organisms often results in low local concentrations of enzymes and substrates, leading to a low productive efficacy. We developed a new method to accelerate a heterologous metabolic system by integrating a transcription activator-like effector (TALE)-based scaffold system into an Escherichia coli chassis. The binding abilities of the TALEs to the artificial DNA scaffold were measured through ChIP-PCR. The effect of the system was determined through a split GFP study and validated through the heterologous production of indole-3-acetic acid (IAA) by incorporating TALE-fused IAA biosynthetic enzymes in E. coli. To the best of our knowledge, we are the first to use the TALE system as a scaffold for the spatial organization of bacterial metabolism. This technique might be used to establish multi-enzymatic reaction programs in a prokaryotic chassis for various applications.

  20. Malignant phyllodes tumor of the breast with heterologous high-grade angiosarcoma

    Directory of Open Access Journals (Sweden)

    Ghassan Tranesh

    2017-03-01

    Full Text Available Phyllodes tumors (PTs account for <3% of fibroepithelial breast lesions and for 0.3% to 1.0% of primary breast tumors. They occur predominantly in middle-aged women (mean age range, 40–50 years. PTs can be categorized into benign, borderline, and malignant; the first 2 categories are distinguished only by degree of cellular atypia and mitotic activity. Malignant PTs are more frequent among persons of Hispanic ethnicity, especially those born in Central America or South America. Heterologous sarcomatous elements may be present in malignant PTs, predominantly liposarcoma and rarely fibrosarcoma, rhabdomyosarcoma, leiomyosarcoma, osteosarcoma, and chondrosarcoma. Breast angiosarcoma (BA is a rare heterologous, sarcomatous element that may arise secondary to malignant PT. We report a 47-year-old woman with no history of previous surgery or radiation therapy who presented to the emergency department with a painful right breast mass. She admittedly noticed the right breast mass for many years; however, recently it increased in size. Mammography and ultrasonography identified a partially cystic mass. Core needle biopsy showed dense hyalinized fibrous tissue with old blood clots, suggestive of infarcted fibroadenoma. The patient received antibiotics and analgesics; however, she reported intractable pain and a worsening skin rash of her right breast. Chest computed tomography and magnetic resonance imaging showed a doubling in mass size, with pectoralis major muscle involvement. Incisional biopsy showed malignant PT with heterologous high-grade angiosarcoma. The diagnosis of angiosarcoma was confirmed through immunoreactivity for CD31, FLI1, and ERG immunostains.

  1. Paradoxical associations between soil-transmitted helminths and Plasmodium falciparum infection.

    Science.gov (United States)

    Fernández-Niño, Julián A; Idrovo, Alvaro J; Cucunubá, Zulma M; Reyes-Harker, Patricia; Guerra, Ángela P; Moncada, Ligia I; López, Myriam C; Barrera, Sandra M; Cortés, Liliana J; Olivera, Mario; Nicholls, Rubén S

    2012-11-01

    Evidence on the comorbidity between soil-transmitted helminth infections and malaria is scarce and divergent. This study explored the interactions between soil-transmitted helminth infections and uncomplicated falciparum malaria in an endemic area of Colombia. A paired case-control study matched by sex, age and location in Tierralta, Cordoba, was done between January and September 2010. The incident cases were 68 patients with falciparum malaria and 178 asymptomatic controls. A questionnaire was used to gather information on sociodemographic variables. Additionally physical examinations were carried out, stool samples were analysed for intestinal parasites and blood samples for Ig E concentrations. We found associations between infection with hookworm (OR: 4.21; 95% CI: 1.68-11.31) and Ascaris lumbricoides (OR 0.43; 95% CI: 0.18-1.04) and the occurrence of falciparum malaria. The effects of soil-transmitted helminths on the occurrence of malaria were found to be paradoxical. While hookworm is a risk factor, A. lumbricoides has a protective effect. The findings suggest that, in addition to the comorbidity, the presence of common determinants of soil-transmitted helminth infections and malaria could also exist. While the biological mechanisms involved are not clear, public health policies aimed at the control of their common social and environmental determinants are suggested. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

  2. The C Terminus of the Core β-Ladder Domain in Japanese Encephalitis Virus Nonstructural Protein 1 Is Flexible for Accommodation of Heterologous Epitope Fusion.

    Science.gov (United States)

    Yen, Li-Chen; Liao, Jia-Teh; Lee, Hwei-Jen; Chou, Wei-Yuan; Chen, Chun-Wei; Lin, Yi-Ling; Liao, Ching-Len

    2016-02-01

    NS1 is the only nonstructural protein that enters the lumen of the endoplasmic reticulum (ER), where NS1 is glycosylated, forms a dimer, and is subsequently secreted during flavivirus replication as dimers or hexamers, which appear to be highly immunogenic to the infected host, as protective immunity can be elicited against homologous flavivirus infections. Here, by using a trans-complementation assay, we identified the C-terminal end of NS1 derived from Japanese encephalitis virus (JEV), which was more flexible than other regions in terms of housing foreign epitopes without a significant impact on virus replication. This mapped flexible region is located in the conserved tip of the core β-ladder domain of the multimeric NS1 structure and is also known to contain certain linear epitopes, readily triggering specific antibody responses from the host. Despite becoming attenuated, recombinant JEV with insertion of a neutralizing epitope derived from enterovirus 71 (EV71) into the C-terminal end of NS1 not only could be normally released from infected cells, but also induced dual protective immunity for the host to counteract lethal challenge with either JEV or EV71 in neonatal mice. These results indicated that the secreted multimeric NS1 of flaviviruses may serve as a natural protein carrier to render epitopes of interest more immunogenic in the C terminus of the core β-ladder domain. The positive-sense RNA genomes of mosquito-borne flaviviruses appear to be flexible in terms of accommodating extra insertions of short heterologous antigens into their virus genes. Here, we illustrate that the newly identified C terminus of the core β-ladder domain in NS1 could be readily inserted into entities such as EV71 epitopes, and the resulting NS1-epitope fusion proteins appeared to maintain normal virus replication, secretion ability, and multimeric formation from infected cells. Nonetheless, such an insertion attenuated the recombinant JEV in mice, despite having retained

  3. Changing Patterns of Gastrointestinal Parasite Infections in Cambodian Children: 2006–2011

    Science.gov (United States)

    Hor, Put Chhat; Soeng, Sona; Sun, Sopheary; Lee, Sue J.; Parry, Christopher M.; Day, Nicholas P. J.; Stoesser, Nicole

    2012-01-01

    We studied gastrointestinal parasites in symptomatic Cambodian children attending a provincial hospital in Siem Reap, Cambodia between 2006 and 2011. A total of 16 372 faecal samples were examined by direct microscopy. Parasites were detected in 3121 (19.1%) samples and most common were Giardia lamblia (8.0% of samples; 47.6% disease episodes), hookworm (5.1%; 30.3%) and Strongyloides stercoralis (2.6%; 15.6%). The proportion of infected children increased, and the number of disease episodes effectively treated with a single dose of mebendazole decreased, over the 5-year period. PMID:22723077

  4. Effect of challenge of pigs previously immunised with inactivated vaccines containing homologous and heterologous Mycoplasma hyopneumoniae strains

    Directory of Open Access Journals (Sweden)

    Villarreal Iris

    2012-01-01

    significant differences in protective efficacy between bacterins containing homologous and heterologous M. hyopneumoniae strains. Further research is necessary to better characterize the antigens involved in protection and to elucidate the protective immunity responses following M. hyopneumoniae vaccination and/or infection.

  5. Effect of challenge of pigs previously immunised with inactivated vaccines containing homologous and heterologous Mycoplasma hyopneumoniae strains.

    Science.gov (United States)

    Villarreal, Iris; Vranckx, Katleen; Calus, Dries; Pasmans, Frank; Haesebrouck, Freddy; Maes, Dominiek

    2012-01-06

    efficacy between bacterins containing homologous and heterologous M. hyopneumoniae strains. Further research is necessary to better characterize the antigens involved in protection and to elucidate the protective immunity responses following M. hyopneumoniae vaccination and/or infection.

  6. Bovine adenovirus type 3 containing heterologous protein in the C-terminus of minor capsid protein IX

    International Nuclear Information System (INIS)

    Zakhartchouk, Alexander; Connors, Wayne; Van Kessel, Andrew; Tikoo, Suresh Kumar

    2004-01-01

    Earlier, we detected pIX of BAdV-3 as a 14-kDa protein in purified virions. Analysis of BAdV-3 pIX using different region antibodies revealed that the N-terminus and central domain of the pIX contain immunogenic sites and are not exposed on the surface of BAdV-3 virion. This suggested that the C-terminus of BAdV-3 pIX (125 amino acid) may be exposed on the virion and may be used as a site for incorporation of heterologous peptides or proteins. We constructed recombinant BAV950 containing a small peptide (21 amino acid), including the RGD motif or recombinant BAV951 containing enhanced yellow-green fluorescent protein (EYFP) fused to the C-terminus of pIX. Western blot analysis demonstrated that the chimeric pIX-RGD was incorporated into virion capsids. Incorporation of the RGD motif into the pIX resulted in significant augmentation of BAdV-3 fiber knob-independent infection of the integrin-positive cells, suggesting that RGD motifs are displayed on the surface of virion capsids and are accessible for binding to integrins. Analysis of BAV951 revealed that the chimeric pIX is incorporated into virion capsids and EYFP containing the C-terminus of pIX is exposed on the surface of the virion. Moreover, insertion of chimeric pIXs was maintained without change through successive rounds of viral replication. These results suggested that in contrast to major capsid proteins (hexon, penton, fiber), the minor capsid protein IX can be use for the incorporation of targeting ligands based on either small peptides or longer polypeptides

  7. Antibody-dependent enhancement of dengue virus infection is inhibited by SA-17, a doxorubicin derivative

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa; Jarupathirun, Patsaporn; Kaptein, Suzanne; Neyts, Johan; Smit, Jolanda

    2013-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus (DENV)-induced disease during a heterologous re-infection. Despite ADE's clinical impact, only a few antiviral compounds have been assessed for their anti-ADE activity. We reported earlier

  8. A coproantigen diagnostic test for Strongyloides infection.

    Directory of Open Access Journals (Sweden)

    Alex M Sykes

    Full Text Available Accurate diagnosis of infection with the parasite Strongyloides stercoralis is hampered by the low concentration of larvae in stool, rendering parasitological diagnosis insensitive. Even if the more sensitive agar plate culture method is used repeated stool sampling is necessary to achieve satisfactory sensitivity. In this manuscript we describe the development of a coproantigen ELISA for diagnosis of infection. Polyclonal rabbit antiserum was raised against Strongyloides ratti excretory/secretory (E/S antigen and utilized to develop an antigen capture ELISA. The assay enabled detection of subpatent rodent S. ratti and human S. stercoralis infection. No cross-reactivity was observed with purified E/S from Schistosoma japonicum, the hookworms Ancylostoma caninum, A. ceylanicum, nor with fecal samples collected from rodents harboring Trichuris muris or S. mansoni infection. Strongyloides coproantigens that appear stable when frozen as formalin-extracted fecal supernatants stored at -20 °C remained positive up to 270 days of storage, whereas supernatants stored at 4 °C tested negative. These results indicate that diagnosis of human strongyloidiasis by detection of coproantigen is an approach worthy of further development.

  9. Heterologous overexpression of Glomerella cingulata FAD-dependent glucose dehydrogenase in Escherichia coli and Pichia pastoris

    Directory of Open Access Journals (Sweden)

    Sygmund Christoph

    2011-12-01

    Full Text Available Abstract Background FAD dependent glucose dehydrogenase (GDH currently raises enormous interest in the field of glucose biosensors. Due to its superior properties such as high turnover rate, substrate specificity and oxygen independence, GDH makes its way into glucose biosensing. The recently discovered GDH from the ascomycete Glomerella cingulata is a novel candidate for such an electrochemical application, but also of interest to study the plant-pathogen interaction of a family of wide-spread, crop destroying fungi. Heterologous expression is a necessity to facilitate the production of GDH for biotechnological applications and to study its physiological role in the outbreak of anthracnose caused by Glomerella (anamorph Colletotrichum spp. Results Heterologous expression of active G. cingulata GDH has been achieved in both Escherichia coli and Pichia pastoris, however, the expressed volumetric activity was about 4800-fold higher in P. pastoris. Expression in E. coli resulted mainly in the formation of inclusion bodies and only after co-expression with molecular chaperones enzymatic activity was detected. The fed-batch cultivation of a P. pastoris transformant resulted in an expression of 48,000 U L-1 of GDH activity (57 mg L-1. Recombinant GDH was purified by a two-step purification procedure with a yield of 71%. Comparative characterization of molecular and catalytic properties shows identical features for the GDH expressed in P. pastoris and the wild-type enzyme from its natural fungal source. Conclusions The heterologous expression of active GDH was greatly favoured in the eukaryotic host. The efficient expression in P. pastoris facilitates the production of genetically engineered GDH variants for electrochemical-, physiological- and structural studies.

  10. Heterologous overexpression of Glomerella cingulata FAD-dependent glucose dehydrogenase in Escherichia coli and Pichia pastoris.

    Science.gov (United States)

    Sygmund, Christoph; Staudigl, Petra; Klausberger, Miriam; Pinotsis, Nikos; Djinović-Carugo, Kristina; Gorton, Lo; Haltrich, Dietmar; Ludwig, Roland

    2011-12-12

    FAD dependent glucose dehydrogenase (GDH) currently raises enormous interest in the field of glucose biosensors. Due to its superior properties such as high turnover rate, substrate specificity and oxygen independence, GDH makes its way into glucose biosensing. The recently discovered GDH from the ascomycete Glomerella cingulata is a novel candidate for such an electrochemical application, but also of interest to study the plant-pathogen interaction of a family of wide-spread, crop destroying fungi. Heterologous expression is a necessity to facilitate the production of GDH for biotechnological applications and to study its physiological role in the outbreak of anthracnose caused by Glomerella (anamorph Colletotrichum) spp. Heterologous expression of active G. cingulata GDH has been achieved in both Escherichia coli and Pichia pastoris, however, the expressed volumetric activity was about 4800-fold higher in P. pastoris. Expression in E. coli resulted mainly in the formation of inclusion bodies and only after co-expression with molecular chaperones enzymatic activity was detected. The fed-batch cultivation of a P. pastoris transformant resulted in an expression of 48,000 U L⁻¹ of GDH activity (57 mg L⁻¹). Recombinant GDH was purified by a two-step purification procedure with a yield of 71%. Comparative characterization of molecular and catalytic properties shows identical features for the GDH expressed in P. pastoris and the wild-type enzyme from its natural fungal source. The heterologous expression of active GDH was greatly favoured in the eukaryotic host. The efficient expression in P. pastoris facilitates the production of genetically engineered GDH variants for electrochemical-, physiological- and structural studies.

  11. Heterologous Production of a Novel Cyclic Peptide Compound, KK-1, in Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Akira Yoshimi

    2018-04-01

    Full Text Available A novel cyclic peptide compound, KK-1, was originally isolated from the plant-pathogenic fungus Curvularia clavata. It consists of 10 amino acid residues, including five N-methylated amino acid residues, and has potent antifungal activity. Recently, the genome-sequencing analysis of C. clavata was completed, and the biosynthetic genes involved in KK-1 production were predicted by using a novel gene cluster mining tool, MIDDAS-M. These genes form an approximately 75-kb cluster, which includes nine open reading frames, containing a non-ribosomal peptide synthetase (NRPS gene. To determine whether the predicted genes were responsible for the biosynthesis of KK-1, we performed heterologous production of KK-1 in Aspergillus oryzae by introduction of the cluster genes into the genome of A. oryzae. The NRPS gene was split in two fragments and then reconstructed in the A. oryzae genome, because the gene was quite large (approximately 40 kb. The remaining seven genes in the cluster, excluding the regulatory gene kkR, were simultaneously introduced into the strain of A. oryzae in which NRPS had already been incorporated. To evaluate the heterologous production of KK-1 in A. oryzae, gene expression was analyzed by RT-PCR and KK-1 productivity was quantified by HPLC. KK-1 was produced in variable quantities by a number of transformed strains, along with expression of the cluster genes. The amount of KK-1 produced by the strain with the greatest expression of all genes was lower than that produced by the original producer, C. clavata. Therefore, expression of the cluster genes is necessary and sufficient for the heterologous production of KK-1 in A. oryzae, although there may be unknown factors limiting productivity in this species.

  12. Heterologous Production of a Novel Cyclic Peptide Compound, KK-1, in Aspergillus oryzae.

    Science.gov (United States)

    Yoshimi, Akira; Yamaguchi, Sigenari; Fujioka, Tomonori; Kawai, Kiyoshi; Gomi, Katsuya; Machida, Masayuki; Abe, Keietsu

    2018-01-01

    A novel cyclic peptide compound, KK-1, was originally isolated from the plant-pathogenic fungus Curvularia clavata . It consists of 10 amino acid residues, including five N -methylated amino acid residues, and has potent antifungal activity. Recently, the genome-sequencing analysis of C. clavata was completed, and the biosynthetic genes involved in KK-1 production were predicted by using a novel gene cluster mining tool, MIDDAS-M. These genes form an approximately 75-kb cluster, which includes nine open reading frames, containing a non-ribosomal peptide synthetase (NRPS) gene. To determine whether the predicted genes were responsible for the biosynthesis of KK-1, we performed heterologous production of KK-1 in Aspergillus oryzae by introduction of the cluster genes into the genome of A. oryzae . The NRPS gene was split in two fragments and then reconstructed in the A. oryzae genome, because the gene was quite large (approximately 40 kb). The remaining seven genes in the cluster, excluding the regulatory gene kkR , were simultaneously introduced into the strain of A. oryzae in which NRPS had already been incorporated. To evaluate the heterologous production of KK-1 in A. oryzae , gene expression was analyzed by RT-PCR and KK-1 productivity was quantified by HPLC. KK-1 was produced in variable quantities by a number of transformed strains, along with expression of the cluster genes. The amount of KK-1 produced by the strain with the greatest expression of all genes was lower than that produced by the original producer, C. clavata . Therefore, expression of the cluster genes is necessary and sufficient for the heterologous production of KK-1 in A. oryzae , although there may be unknown factors limiting productivity in this species.

  13. Longitudinal study of experimental induction of AA amyloidosis in mice seeded with homologous and heterologous AA fibrils.

    Science.gov (United States)

    Muhammad, Naeem; Murakami, Tomoaki; Inoshima, Yasuo; Ishiguro, Naotaka

    2016-09-01

    To investigate pathogenesis and kinetics of experimentally induced murine AA amyloidosis seeded with homologous (murine) and heterologous (bovine) AA fibrils. Experimental AA amyloidosis was induced by administration of inflammatory stimulus and preformed AA fibrils to a total of 111 female C57/Black mice. In this longitudinal study, heterologous (bovine) as well as homologous (murine) AA fibrils were injected intraperitoneally to mice in various combinations. Re-stimulation was done at 120 or 300 days post first inoculation. To analyze the intensity of amyloid depositions in mice organs, immunohistochemical techniques and image J software were used. Assessment of cytokines level in sera was done using a Mouse Th1/Th2/Th17 Cytokine CBA Kit. Incidence and severity of AA amyloidosis were quite low in mice inoculated with heterologous bovine AA fibrils than homologous murine one. Homologous AA fibrils administration at first and second inoculation caused maximum amount of amyloid depositions and severe systemic form of amyloidosis. Increase in the level of pro-inflammatory cytokine IL-6 was observed after first inoculation, while second inoculation caused a further increase in the level of anti-inflammatory cytokine IL-10. AA amyloidosis can be induced by heterologous as well as homologous AA fibrils. Severity of AA amyloidosis induced with homologous AA fibrils is higher compared to heterologous AA fibrils.

  14. Comparative genomic analysis identified a mutation related to enhanced heterologous protein production in the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Jin, Feng-Jie; Katayama, Takuya; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2016-11-01

    Genomic mapping of mutations using next-generation sequencing technologies has facilitated the identification of genes contributing to fundamental biological processes, including human diseases. However, few studies have used this approach to identify mutations contributing to heterologous protein production in industrial strains of filamentous fungi, such as Aspergillus oryzae. In a screening of A. oryzae strains that hyper-produce human lysozyme (HLY), we previously isolated an AUT1 mutant that showed higher production of various heterologous proteins; however, the underlying factors contributing to the increased heterologous protein production remained unclear. Here, using a comparative genomic approach performed with whole-genome sequences, we attempted to identify the genes responsible for the high-level production of heterologous proteins in the AUT1 mutant. The comparative sequence analysis led to the detection of a gene (AO090120000003), designated autA, which was predicted to encode an unknown cytoplasmic protein containing an alpha/beta-hydrolase fold domain. Mutation or deletion of autA was associated with higher production levels of HLY. Specifically, the HLY yields of the autA mutant and deletion strains were twofold higher than that of the control strain during the early stages of cultivation. Taken together, these results indicate that combining classical mutagenesis approaches with comparative genomic analysis facilitates the identification of novel genes involved in heterologous protein production in filamentous fungi.

  15. Diversion of flux toward sesquiterpene production in Saccharomyces cerevisiae by fusion of host and heterologous enzymes

    DEFF Research Database (Denmark)

    Albertsen, Line; Chen, Yun; Bach, Lars Stougaard

    2011-01-01

    be limited by the inability of the heterologous enzymes to collaborate with the native yeast enzymes. This may cause loss of intermediates by diffusion or degradation or due to conversion of the intermediate through competitive pathways. To bypass this problem, we have pursued a strategy in which key enzymes...... increased the production of patchoulol, the main sesquiterpene produced by PTS, up to 2-fold. Moreover, we have demonstrated that the fusion strategy can be used in combination with traditional metabolic engineering to further increase the production of patchoulol. This simple test case of synthetic biology...

  16. Heterologous expression of plasmodial proteins for structural studies and functional annotation

    CSIR Research Space (South Africa)

    Birkholtz, LM

    2008-01-01

    Full Text Available Malaria Journal Open AcceReview Heterologous expression of plasmodial proteins for structural studies and functional annotation Lyn-Marie Birkholtz1, Gregory Blatch2, Theresa L Coetzer3, Heinrich C Hoppe1,4, Esmaré Human1, Elizabeth J Morris1,5, Zoleka Ngcete..., Kwadlangezwa, South Africa Email: Lyn-Marie Birkholtz - lbirkholtz@up.ac.za; Gregory Blatch - G.Blatch@ru.ac.za; Theresa L Coetzer - theresa.coetzer@nhls.ac.za; Heinrich C Hoppe - hhoppe@csir.co.za; Esmaré Human - esmare.human@up.ac.za; Elizabeth J Morris...

  17. Heterologous expression of a deuterated membrane-integrated receptor and partial deuteration in methylotrophic yeasts

    International Nuclear Information System (INIS)

    Massou, S.; Puech, V.; Talmont, F.; Demange, P.; Lindley, N.D.; Tropis, M.; Milon, A.

    1999-01-01

    Methylotrophic yeast has previously been shown to be an excellent system for the cost-effective production of perdeuterated biomass and for the heterologous expression of membrane receptors. A protocol for the expression of 85% deuterated, functional human μ-opiate receptor was established. For partially deuterated biomass, deuteration level and distribution were determined for fatty acids, amino acids and carbohydrates. It was shown that prior to biosynthesis of lipids and amino acids (and of carbohydrates, to a lower extent), exchange occurs between water and methanol hydrogen atoms, so that 80%-90% randomly deuterated biomass and over-expressed proteins may be obtained using only deuterated water

  18. Responses of Synechocystis sp. PCC 6803 to heterologous biosynthetic pathways

    DEFF Research Database (Denmark)

    Vavitsas, Konstantinos; Rue, Emil Østergaard; Stefánsdóttir, Lára Kristín

    2017-01-01

    BACKGROUND: There are an increasing number of studies regarding genetic manipulation of cyanobacteria to produce commercially interesting compounds. The majority of these works study the expression and optimization of a selected heterologous pathway, largely ignoring the wholeness and complexity...... different compounds, the cyanogenic glucoside dhurrin and the diterpenoid 13R-manoyl oxide in Synechocystis PCC 6803. We used genome-scale metabolic modelling to study fluxes in individual reactions and pathways, and we determined the concentrations of key metabolites, such as amino acids, carotenoids...

  19. High-yields heterologous production of the novel Aspergillus fumigatus elastase inhibitor AFUEI in Aspergillus oryzae.

    Science.gov (United States)

    Yamashita, Nobuo; Komori, Yumiko; Okumura, Yoshiyuki; Uchiya, Kei-Ichi; Matsui, Takeshi; Nishimura, Akira; Ogawa, Kenji; Nikai, Toshiaki

    2011-08-01

    AFUEI, an elastase inhibitor produced by Aspergillus fumigatus strongly inhibits the elastolytic activity of A. fumigatus etc. To purify AFUEI, we constructed a strain that overproduces AFUEI by introducing the gene encoding AFUEI (Genbank accession no. AB546725) under control of the amyB promoter into the heterologous host Aspergillus oryzae. A. oryzae TF-4 displayed strong elastase inhibitory activity and produced considerably more AFUEI than that of A. fumigatus. Furthermore, AFUEI could be purified using culture broth and single ultrafiltration (UF) treatment, allowing for the effective production of AFUEI for use in clinical trials. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. The relationship between helminth infections and low haemoglobin levels in Ethiopian children with blood type A.

    Science.gov (United States)

    Degarege, A; Yimam, Y; Madhivanan, P; Erko, B

    2017-05-01

    The current study was conducted to evaluate the nature of association of ABO blood type with helminth infection and related reduction in haemoglobin concentration. Stool samples were collected from 403 school-age children attending Tikur Wuha Elementary School from February to April 2011. Helminth infection was examined using formol-ether concentration and thick Kato-Katz (two slides per stool specimen) techniques. Haemoglobin level was determined using a HemoCue machine and ABO blood type was determined using the antisera haemagglutination test. Nutritional status was assessed using height and weight measurements. Out of 403 children examined, 169, 120, 96 and 18 had blood type O, A, B and AB, respectively. The prevalences of helminth infections were 46.9% for hookworm, 24.6% for Schistosoma mansoni, 4.2% for Ascaris lumbricoides, 1.7% for Trichuris trichiura and 58.3% for any helminth species. The relative odds of infection with at least one helminth species was significantly higher among children with blood type A (adjusted odds ratio (AOR), 2.10; 95% confidence interval (CI), 1.28-3.45) or blood type B (AOR, 2.08; 95% CI, 1.22-3.56) as compared to children with blood type O. Among children infected with helminths, mean haemoglobin concentration was lower in those with blood type A than those with blood type O (β, -0.36; 95% CI, -0.72 to -0.01). The relative odds of hookworm infection (AOR, 1.78; 95% CI, 1.08-2.92) and related reduction in haemogobin levels (β, -0.45; 95% CI, -0.84 to -0.04) was higher among children with blood type A as compared to those with blood type O. Although the difference was not significant, the relative odds of S. mansoni or A. lumbricoides infections and related reduction in haemoglobin levels was also higher in children with blood type A or B as compared to children with blood type O. In conclusion, children with blood type A are associated with an increased risk of helminth, particularly hookworm, infection and related reduction

  1. Intestinal helminth infections in feral cats and a raccoon dog on Aphaedo Island, Shinan-gun, with a special note on Gymnophalloides seoi infection in cats.

    Science.gov (United States)

    Shin, Eun-Hee; Park, Jae-Hwan; Guk, Sang-Mee; Kim, Jae-Lip; Chai, Jong-Yil

    2009-06-01

    Four feral cats and a raccoon dog purchased from a local collector on Aphaedo Island, Shinan-gun, where human Gymnophalloides seoi infections are known to be prevalent, were examined for their intestinal helminth parasites. From 2 of 4 cats, a total of 310 adult G. seoi specimens were recovered. Other helminths detected in cats included Heterophyes nocens (1,527 specimens), Pygidiopsis summa (131), Stictodora fuscata (4), Acanthotrema felis (2), Spirometra erinacei (15), toxocarids (4), and a hookworm (1). A raccoon dog was found to be infected with a species of echinostome (55), hookworms (7), toxocarids (3), P. summa (3), and S. erinacei (1). No G. seoi was found in the raccoon dog. The results indicate that feral cats and raccoon dogs on Aphaedo are natural definitive hosts for intestinal trematodes and cestodes, including G. seoi, H. nocens, and S. erinacei. It has been first confirmed that cats, a mammalian species other than humans, play the role of a natural definitive host for G. seoi on Aphaedo Island.

  2. Cross-amplification of heterologous microsatellite markers in Rhamdia quelen and Leporinus elongatus

    Directory of Open Access Journals (Sweden)

    Nelson Mauricio Lopera-Barrero

    2016-02-01

    Full Text Available Native fish species in Brazil are an asset in fish farming, but their natural stocks have been significantly reduced in recent years. To mitigate this negative impact, studies on fish conservation are being conducted and genetic tools for the discrimination of population parameters are increasingly achieving great importance. Current analysis evaluates a set of microsatellite heterologous primers in the jundiá (Rhamdia quelen and in the piapara (Leporinus elongatus. Samples from the caudal fin of 15 broodstock from each species were analyzed. DNA extraction was performed with NaCl protocol and the integrity of the extracted DNA was checked with agarose gel 1%. Twenty primers developed for Piaractus mesopotamicus, Colossoma macropomum, Prochilodus lineatus, Brycon opalinus and Oreochromis niloticus were evaluated. Cross amplification of four primers of the B. opalinus and P. lineatus species (BoM12, Pli43 and Pli60 in R. quelen and BoM2, Pli43 and Pli60 in L. elongatus was assessed. Primers of P. mesopotamicus, C. macropomum and O. niloticus showed no cross amplification in the two species analyzed. Results revealed the possibility of using the four amplified heterologous primers in genetic studies for R. quelen and L. elongatus.

  3. Isobutanol production in Synechocystis PCC 6803 using heterologous and endogenous alcohol dehydrogenases

    Directory of Open Access Journals (Sweden)

    Rui Miao

    2017-12-01

    Full Text Available Isobutanol is a flammable compound that can be used as a biofuel due to its high energy density and suitable physical and chemical properties. In this study, we examined the capacity of engineered strains of Synechocystis PCC 6803 containing the α-ketoisovalerate decarboxylase from Lactococcus lactis and different heterologous and endogenous alcohol dehydrogenases (ADH for isobutanol production. A strain expressing an introduced kivd without any additional copy of ADH produced 3 mg L−1 OD750−1 isobutanol in 6 days. After the cultures were supplemented with external addition of isobutyraldehyde, the substrate for ADH, 60.8 mg L−1 isobutanol was produced after 24 h when OD750 was 0.8. The in vivo activities of four different ADHs, two heterologous and two putative endogenous in Synechocystis, were examined and the Synechocystis endogenous ADH encoded by slr1192 showed the highest efficiency for isobutanol production. Furthermore, the strain overexpressing the isobutanol pathway on a self-replicating vector with the strong Ptrc promoter showed significantly higher gene expression and isobutanol production compared to the corresponding strains expressing the same operon introduced on the genome. Hence, this study demonstrates that Synechocystis endogenous AHDs have a high capacity for isobutanol production, and identifies kivd encoded α-ketoisovalerate decarboxylase as one of the likely bottlenecks for further isobutanol production.

  4. Dedifferentiated Leiomyosarcoma of the Uterus with Heterologous Elements: A Potential Diagnostic Pitfall

    Directory of Open Access Journals (Sweden)

    Kojo R. Rawish

    2012-01-01

    Full Text Available Dedifferentiation is a phenomenon that is well characterized in a variety of tumors and is defined by the occurrence of a high-grade or undifferentiated tumor, typically unrecognizable regarding its line of differentiation, from a low-grade/borderline neoplasm. This phenomenon has previously been described in 2 uterine leiomyosarcomas, but both were devoid of heterologous elements. The authors describe herein a case of a dedifferentiated leiomyosarcoma of the uterus with osteoid heterologous elements, believed to be the first such reported case. The original tumor was a high-grade leiomyosarcoma with large low-grade and leiomyoma-like areas and whose constituent cells displayed intense nuclear immunoreactivity for both estrogen receptor (ER and progesterone receptor (PR in approximately 30% of cells. The tumor recurred six months after its resection as an undifferentiated sarcoma that was negative for smooth muscle markers, but which remained positive for ER and PR. Osteoid production was only identified in the recurrent tumor and was significant in extent therein. This case highlights the immunophenotypic changes that may occur in dedifferentiated leiomyosarcomas, and this possibility should be a consideration when an apparently undifferentiated sarcoma is identified in a patient with a history of uterine leiomyosarcoma. In our case, the expression of ER and PR provided significant supportive evidence of the uterine origin of the recurrent tumor.

  5. Heterologous expression of enterocin AS-48 in several strains of lactic acid bacteria.

    Science.gov (United States)

    Fernández, M; Martínez-Bueno, M; Martín, M C; Valdivia, E; Maqueda, M

    2007-05-01

    Enterococcus faecalis produces a cationic and circular enterocin, AS-48, of 7149 Da, the genetic determinants of which are located within the pMB2 plasmid. We have compared enterocin AS-48 production by different enterococci species with that of other 'safe' lactic acid bacteris (LAB) (GRAS status) and looked into the subsequent application of this enterocin in food production. In an effort to exploit this system for the heterologous expression of enterocin AS-48, a number of vectors containing the as-48 cluster were constructed and used to transform several LAB strains (genera Enterococcus, Lactococcus and Lactobacillus) Heterologous production of enterocin AS-48 failed when bacteria other than those belonging to the genus Enterococcus were used as hosts, although expression of a partial level of resistance against AS-48 were always detected, ruling out the possibility of a lack of recognition of the enterococcal promoters. Our results reveal the special capacity of species from the genus Enterococcus to produce AS-48, an enterocin that requires a post-transcriptional modification to generate a circular peptide with a wide range of inhibitory activity against pathogenic and spoilage bacteria. Preliminary experiments in foodstuffs using nonvirulent enterococci with interesting functional properties reveal the possibility of a biotechnological application of these transformants.

  6. Mitochondrial targeting increases specific activity of a heterologous valine assimilation pathway in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Kevin V. Solomon

    2016-12-01

    Full Text Available Bio-based isobutantol is a sustainable ‘drop in’ substitute for petroleum-based fuels. However, well-studied production routes, such as the Ehrlich pathway, have yet to be commercialized despite more than a century of research. The more versatile bacterial valine catabolism may be a competitive alternate route producing not only an isobutanol precursor but several carboxylic acids with applications as biomonomers, and building blocks for other advanced biofuels. Here, we transfer the first two committed steps of the pathway from pathogenic Pseudomonas aeruginosa PAO1 to yeast to evaluate their activity in a safer model organism. Genes encoding the heteroligomeric branched chain keto-acid dehydrogenase (BCKAD; bkdA1, bkdA2, bkdB, lpdV, and the homooligomeric acyl-CoA dehydrogenase (ACD; acd1 were tagged with fluorescence epitopes and targeted for expression in either the mitochondria or cytoplasm of S. cerevisiae. We verified the localization of our constructs with confocal fluorescence microscopy before measuring the activity of tag-free constructs. Despite reduced heterologous expression of mitochondria-targeted enzymes, their specific activities were significantly improved with total enzyme activities up to 138% greater than those of enzymes expressed in the cytoplasm. In total, our results demonstrate that the choice of protein localization in yeast has significant impact on heterologous activity, and suggests a new path forward for isobutanol production. Keywords: Pseudomonas, Isobutanol, Dehydrogenase, Mitochondria, Saccharomyces cerevisiae, Metabolic engineering

  7. Synthetic Promoters and Transcription Factors for Heterologous Protein Expression in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Fabian Machens

    2017-10-01

    Full Text Available Orthogonal systems for heterologous protein expression as well as for the engineering of synthetic gene regulatory circuits in hosts like Saccharomyces cerevisiae depend on synthetic transcription factors (synTFs and corresponding cis-regulatory binding sites. We have constructed and characterized a set of synTFs based on either transcription activator-like effectors or CRISPR/Cas9, and corresponding small synthetic promoters (synPs with minimal sequence identity to the host’s endogenous promoters. The resulting collection of functional synTF/synP pairs confers very low background expression under uninduced conditions, while expression output upon induction of the various synTFs covers a wide range and reaches induction factors of up to 400. The broad spectrum of expression strengths that is achieved will be useful for various experimental setups, e.g., the transcriptional balancing of expression levels within heterologous pathways or the construction of artificial regulatory networks. Furthermore, our analyses reveal simple rules that enable the tuning of synTF expression output, thereby allowing easy modification of a given synTF/synP pair. This will make it easier for researchers to construct tailored transcriptional control systems.

  8. Heterologous Synapsis and Crossover Suppression in Heterozygotes for a Pericentric Inversion in the Zebra Finch.

    Science.gov (United States)

    del Priore, Lucía; Pigozzi, María I

    2015-01-01

    In the zebra finch, 2 alternative morphs regarding centromere position were described for chromosome 6. This polymorphism was interpreted to be the result of a pericentric inversion, but other causes of the centromere repositioning were not ruled out. We used immunofluorescence localization to examine the distribution of MLH1 foci on synaptonemal complexes to test the prediction that pericentric inversions cause synaptic irregularities and/or crossover suppression in heterozygotes. We found complete suppression of crossing over in the region involved in the rearrangement in male and female heterozygotes. In contrast, the same region showed high levels of crossing over in homozygotes for the acrocentric form of this chromosome. No inversion loops or synaptic irregularities were detected along bivalent 6 in heterozygotes suggesting that heterologous pairing is achieved during zygotene or early pachytene. Altogether these findings strongly indicate that the polymorphic chromosome 6 originated by a pericentric inversion. Since inversions are common rearrangements in karyotypic evolution in birds, it seems likely that early heterologous pairing could help to fix these rearrangements, preventing crossing overs in heterozygotes and their deleterious effects on fertility. © 2015 S. Karger AG, Basel.

  9. Xenobiotic Compounds Degradation by Heterologous Expression of a Trametes sanguineus Laccase in Trichoderma atroviride.

    Directory of Open Access Journals (Sweden)

    Edgar Balcázar-López

    Full Text Available Fungal laccases are enzymes that have been studied because of their ability to decolorize and detoxify effluents; they are also used in paper bleaching, synthesis of polymers, bioremediation, etc. In this work we were able to express a laccase from Trametes (Pycnoporus sanguineus in the filamentous fungus Trichoderma atroviride. For this purpose, a transformation vector was designed to integrate the gene of interest in an intergenic locus near the blu17 terminator region. Although monosporic selection was still necessary, stable integration at the desired locus was achieved. The native signal peptide from T. sanguineus laccase was successful to secrete the recombinant protein into the culture medium. The purified, heterologously expressed laccase maintained similar properties to those observed in the native enzyme (Km and kcat and kcat/km values for ABTS, thermostability, substrate range, pH optimum, etc. To determine the bioremediation potential of this modified strain, the laccase-overexpressing Trichoderma strain was used to remove xenobiotic compounds. Phenolic compounds present in industrial wastewater and bisphenol A (an endocrine disruptor from the culture medium were more efficiently removed by this modified strain than with the wild type. In addition, the heterologously expressed laccase was able to decolorize different dyes as well as remove benzo[α]pyrene and phenanthrene in vitro, showing its potential for xenobiotic compound degradation.

  10. Heterologous Expression and Characterization of a Thermostable Exo-β-D-Glucosaminidase from Aspergillus oryzae.

    Science.gov (United States)

    Wu, Dingxin; Wang, Linchun; Li, Yuwei; Zhao, Shumiao; Peng, Nan; Liang, Yunxiang

    2016-02-01

    An exo-β-D-glucosaminidase (AorCsxA) from Aspergillus oryzae FL402 was heterologously expressed and purified. The deduced amino acid sequence indicated that AorCsxA belonged to glycoside hydrolase family 2. AorCsxA digested colloid chitosan into glucosamine but not into chitosan oligosaccharides, demonstrating exo-β-D-glucosaminidase (CsxA) activity. AorCsxA exhibited optimal activity at pH 5.5 and 50°C; however, the enzyme expressed in Pichia pastoris (PpAorCsxA) showed much stronger thermostability at 50°C than that expressed in Escherichia coli (EcAorCsxA), which may be related to glycosylation. AorCsxA activity was inhibited by EDTA and most of the tested metal ions. A single amino acid mutation (F769W) in AorCsxA significantly enhanced the specific activity and hydrolysis velocity as revealed by comparison of Vmax and kcat values with those of the wild-type enzyme. The three-dimensional structure suggested the tightened pocket at the active site of F769W enabled efficient substrate binding. The AorCsxA gene was heterologously expressed in P. pastoris, and one transformant was found to produce 222 U/ml activity during the high-cell-density fermentation. This AorCsxA-overexpressing P. pastoris strain is feasible for large-scale production of AorCsxA.

  11. Combined protein construct and synthetic gene engineering for heterologous protein expression and crystallization using Gene Composer

    Directory of Open Access Journals (Sweden)

    Walchli John

    2009-04-01

    Full Text Available Abstract Background With the goal of improving yield and success rates of heterologous protein production for structural studies we have developed the database and algorithm software package Gene Composer. This freely available electronic tool facilitates the information-rich design of protein constructs and their engineered synthetic gene sequences, as detailed in the accompanying manuscript. Results In this report, we compare heterologous protein expression levels from native sequences to that of codon engineered synthetic gene constructs designed by Gene Composer. A test set of proteins including a human kinase (P38α, viral polymerase (HCV NS5B, and bacterial structural protein (FtsZ were expressed in both E. coli and a cell-free wheat germ translation system. We also compare the protein expression levels in E. coli for a set of 11 different proteins with greatly varied G:C content and codon bias. Conclusion The results consistently demonstrate that protein yields from codon engineered Gene Composer designs are as good as or better than those achieved from the synonymous native genes. Moreover, structure guided N- and C-terminal deletion constructs designed with the aid of Gene Composer can lead to greater success in gene to structure work as exemplified by the X-ray crystallographic structure determination of FtsZ from Bacillus subtilis. These results validate the Gene Composer algorithms, and suggest that using a combination of synthetic gene and protein construct engineering tools can improve the economics of gene to structure research.

  12. Impact of High-Level Expression of Heterologous Protein on Lactococcus lactis Host.

    Science.gov (United States)

    Kim, Mina; Jin, Yerin; An, Hyun-Joo; Kim, Jaehan

    2017-07-28

    The impact of overproduction of a heterologous protein on the metabolic system of host Lactococcus lactis was investigated. The protein expression profiles of L. lactis IL1403 containing two near-identical plasmids that expressed high- and low-level of the green fluorescent protein (GFP) were examined via shotgun proteomics. Analysis of the two strains via high-throughput LC-MS/MS proteomics identified the expression of 294 proteins. The relative amount of each protein in the proteome of both strains was determined by label-free quantification using the spectral counting method. Although expression level of most proteins were similar, several significant alterations in metabolic network were identified in the high GFP-producing strain. These changes include alterations in the pyruvate fermentation pathway, oxidative pentose phosphate pathway, and de novo synthesis pathway for pyrimidine RNA. Expression of enzymes for the synthesis of dTDP-rhamnose and N -acetylglucosamine from glucose was suppressed in the high GFP strain. In addition, enzymes involved in the amino acid synthesis or interconversion pathway were downregulated. The most noticeable changes in the high GFP-producing strain were a 3.4-fold increase in the expression of stress response and chaperone proteins and increase of caseinolytic peptidase family proteins. Characterization of these host expression changes witnessed during overexpression of GFP was might suggested the metabolic requirements and networks that may limit protein expression, and will aid in the future development of lactococcal hosts to produce more heterologous protein.

  13. Heterologous Expression of Tulip Petal Plasma Membrane Aquaporins in Pichia pastoris for Water Channel Analysis▿

    Science.gov (United States)

    Azad, Abul Kalam; Sawa, Yoshihiro; Ishikawa, Takahiro; Shibata, Hitoshi

    2009-01-01

    Water channels formed by aquaporins (AQPs) play an important role in the control of water homeostasis in individual cells and in multicellular organisms. Plasma membrane intrinsic proteins (PIPs) constitute a subclass of plant AQPs. TgPIP2;1 and TgPIP2;2 from tulip petals are members of the PIP family. In this study, we overexpressed TgPIP2;1 and TgPIP2;2 in Pichia pastoris and monitored their water channel activity (WCA) either by an in vivo spheroplast-bursting assay performed after hypo-osmotic shock or by growth assay. Osmolarity, pH, and inhibitors of AQPs, protein kinases (PKs), and protein phosphatases (PPs) affect the WCA of heterologous AQPs in this expression system. The WCA of TgPIP2;2-expressing spheroplasts was affected by inhibitors of PKs and PPs, which indicates that the water channel of this homologue is regulated by phosphorylation in P. pastoris. From the results reported herein, we suggest that P. pastoris can be employed as a heterologous expression system to assay the WCA of PIPs and to monitor the AQP-mediated channel gating mechanism, and it can be developed to screen inhibitors/effectors of PIPs. PMID:19251885

  14. Heterologous expression of tulip petal plasma membrane aquaporins in Pichia pastoris for water channel analysis.

    Science.gov (United States)

    Azad, Abul Kalam; Sawa, Yoshihiro; Ishikawa, Takahiro; Shibata, Hitoshi

    2009-05-01

    Water channels formed by aquaporins (AQPs) play an important role in the control of water homeostasis in individual cells and in multicellular organisms. Plasma membrane intrinsic proteins (PIPs) constitute a subclass of plant AQPs. TgPIP2;1 and TgPIP2;2 from tulip petals are members of the PIP family. In this study, we overexpressed TgPIP2;1 and TgPIP2;2 in Pichia pastoris and monitored their water channel activity (WCA) either by an in vivo spheroplast-bursting assay performed after hypo-osmotic shock or by growth assay. Osmolarity, pH, and inhibitors of AQPs, protein kinases (PKs), and protein phosphatases (PPs) affect the WCA of heterologous AQPs in this expression system. The WCA of TgPIP2;2-expressing spheroplasts was affected by inhibitors of PKs and PPs, which indicates that the water channel of this homologue is regulated by phosphorylation in P. pastoris. From the results reported herein, we suggest that P. pastoris can be employed as a heterologous expression system to assay the WCA of PIPs and to monitor the AQP-mediated channel gating mechanism, and it can be developed to screen inhibitors/effectors of PIPs.

  15. Assessment of Efficacy and Quality of Two Albendazole Brands Commonly Used against Soil-Transmitted Helminth Infections in School Children in Jimma Town, Ethiopia.

    Science.gov (United States)

    Belew, Sileshi; Getachew, Mestawet; Suleman, Sultan; Mohammed, Tesfaye; Deti, Habetewold; D'Hondt, Matthias; Wynendaele, Evelien; Mekonnen, Zeleke; Vercruysse, Jozef; Duchateau, Luc; De Spiegeleer, Bart; Levecke, Bruno

    2015-09-01

    There is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia. A randomized clinical trial was conducted according to the World Health Organization (WHO) guidelines to assess drug efficacy, by means of egg reduction rate (ERR), of Bendex and Ovis against STH infections in school children in Jimma, Ethiopia. In addition, the chemical and physicochemical quality of the drugs was assessed according to the United States and European Pharmacopoeia, encompassing mass uniformity of the tablets, amount of active compound and dissolution profile. Both drugs were highly efficacious against A. lumbricoides (>97%), but showed poor efficacy against T. trichiura (~20%). For hookworms, Ovis was significantly (p Ovis. The study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates

  16. Spatio-temporal distribution of soil-transmitted helminth infections in Brazil.

    Science.gov (United States)

    Chammartin, Frédérique; Guimarães, Luiz H; Scholte, Ronaldo Gc; Bavia, Mara E; Utzinger, Jürg; Vounatsou, Penelope

    2014-09-18

    In Brazil, preventive chemotherapy targeting soil-transmitted helminthiasis is being scaled-up. Hence, spatially explicit estimates of infection risks providing information about the current situation are needed to guide interventions. Available high-resolution national model-based estimates either rely on analyses of data restricted to a given period of time, or on historical data collected over a longer period. While efforts have been made to take into account the spatial structure of the data in the modelling approach, little emphasis has been placed on the temporal dimension. We extracted georeferenced survey data on the prevalence of infection with soil-transmitted helminths (i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura) in Brazil from the Global Neglected Tropical Diseases (GNTD) database. Selection of the most important predictors of infection risk was carried out using a Bayesian geostatistical approach and temporal models that address non-linearity and correlation of the explanatory variables. The spatial process was estimated through a predictive process approximation. Spatio-temporal models were built on the selected predictors with integrated nested Laplace approximation using stochastic partial differential equations. Our models revealed that, over the past 20 years, the risk of soil-transmitted helminth infection has decreased in Brazil, mainly because of the reduction of A. lumbricoides and hookworm infections. From 2010 onwards, we estimate that the infection prevalences with A. lumbricoides, hookworm and T. trichiura are 3.6%, 1.7% and 1.4%, respectively. We also provide a map highlighting municipalities in need of preventive chemotherapy, based on a predicted soil-transmitted helminth infection risk in excess of 20%. The need for treatments in the school-aged population at the municipality level was estimated at 1.8 million doses of anthelminthic tablets per year. The analysis of the spatio-temporal aspect of the risk of infection

  17. Effects of maturation-inducing hormone on heterologous gap junctional coupling in ovarian follicles of Atlantic croaker

    Science.gov (United States)

    Yoshizaki, G.; Patino, R.; Thomas, P.; Bolamba, D.; Chang, Xiaotian

    2001-01-01

    A previous ultrastructural study of heterologous (granulosa cell-oocyte) gap junction (GJ) contacts in ovarian follicles of Atlantic croaker suggested that these contacts disappear late during the process of resumption of oocyte meiosis. This observation suggested that, unlike scenarios proposed for a number of other species, uncoupling of GJ is not necessary for the onset of meiotic resumption in croaker follicles. However, the functionality of heterologous GJ contacts and the temporal association between maturation-inducing hormone (MIH)-induced changes in heterologous coupling and resumption of oocyte meiosis have not been examined in Atlantic croaker. These questions were addressed with a cell-cell coupling assay that is based on the transfer of a GJ marker, Lucifer Yellow, from oocytes to granulosa cells. Follicle-enclosed oocytes injected with Lucifer Yellow allowed transfer of the dye into the follicle cell layer, thus confirming that there is functional heterologous coupling between the oocyte and the granulosa cells. Dye transfer was observed in vitellogenic, full-grown/maturation-incompetent, and full-grown /maturation-competent follicles. Treatment of maturation-competent follicles with MIH caused a time-dependent decline in the number of follicles transferring dye. However, although GJ uncoupling in some of the follicles was observed before germinal vesicle breakdown (GVBD, index of meiotic resumption), about 50% of the follicles maintained the ability to transfer dye even after GVBD had occurred. Further, a known GJ inhibitor (phorbol 12-myristate 13-acetate) blocked heterologous GJ within a time frame similar to that seen with MIH but without inducing any of the morphological changes (including GVBD) associated with follicular maturation. In conclusion, uncoupling of heterologous GJ seems insufficient and unnecessary for the onset of meiotic resumption in ovarian follicles of Atlantic croaker. ?? 2001 Elsevier Science.

  18. Spatial analysis and risk mapping of soil-transmitted helminth infections in Brazil, using Bayesian geostatistical models.

    Science.gov (United States)

    Scholte, Ronaldo G C; Schur, Nadine; Bavia, Maria E; Carvalho, Edgar M; Chammartin, Frédérique; Utzinger, Jürg; Vounatsou, Penelope

    2013-11-01

    Soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura and hookworm) negatively impact the health and wellbeing of hundreds of millions of people, particularly in tropical and subtropical countries, including Brazil. Reliable maps of the spatial distribution and estimates of the number of infected people are required for the control and eventual elimination of soil-transmitted helminthiasis. We used advanced Bayesian geostatistical modelling, coupled with geographical information systems and remote sensing to visualize the distribution of the three soil-transmitted helminth species in Brazil. Remotely sensed climatic and environmental data, along with socioeconomic variables from readily available databases were employed as predictors. Our models provided mean prevalence estimates for A. lumbricoides, T. trichiura and hookworm of 15.6%, 10.1% and 2.5%, respectively. By considering infection risk and population numbers at the unit of the municipality, we estimate that 29.7 million Brazilians are infected with A. lumbricoides, 19.2 million with T. trichiura and 4.7 million with hookworm. Our model-based maps identified important risk factors related to the transmission of soiltransmitted helminths and confirm that environmental variables are closely associated with indices of poverty. Our smoothed risk maps, including uncertainty, highlight areas where soil-transmitted helminthiasis control interventions are most urgently required, namely in the North and along most of the coastal areas of Brazil. We believe that our predictive risk maps are useful for disease control managers for prioritising control interventions and for providing a tool for more efficient surveillance-response mechanisms.

  19. Parasitic infection improves survival from septic peritonitis by enhancing mast cell responses to bacteria in mice.

    Directory of Open Access Journals (Sweden)

    Rachel E Sutherland

    Full Text Available Mammals are serially infected with a variety of microorganisms, including bacteria and parasites. Each infection reprograms the immune system's responses to re-exposure and potentially alters responses to first-time infection by different microorganisms. To examine whether infection with a metazoan parasite modulates host responses to subsequent bacterial infection, mice were infected with the hookworm-like intestinal nematode Nippostrongylus brasiliensis, followed in 2-4 weeks by peritoneal injection of the pathogenic bacterium Klebsiella pneumoniae. Survival from Klebsiella peritonitis two weeks after parasite infection was better in Nippostrongylus-infected animals than in unparasitized mice, with Nippostrongylus-infected mice having fewer peritoneal bacteria, more neutrophils, and higher levels of protective interleukin 6. The improved survival of Nippostrongylus-infected mice depends on IL-4 because the survival benefit is lost in mice lacking IL-4. Because mast cells protect mice from Klebsiella peritonitis, we examined responses in mast cell-deficient Kit(W-sh/Kit(W-sh mice, in which parasitosis failed to improve survival from Klebsiella peritonitis. However, adoptive transfer of cultured mast cells to Kit(W-sh/Kit(W-sh mice restored survival benefits of parasitosis. These results show that recent infection with Nippostrongylus brasiliensis protects mice from Klebsiella peritonitis by modulating mast cell contributions to host defense, and suggest more generally that parasitosis can yield survival advantages to a bacterially infected host.

  20. Vaginal Infections

    Science.gov (United States)

    ... gov/ Home Body Your reproductive health Vaginal infections Vaginal infections Help for infections If you have pain, ... infections and how to prevent them. Types of vaginal infections top Two common vaginal infections are bacterial ...

  1. Infective Endocarditis

    Science.gov (United States)

    ... Center > Infective Endocarditis Menu Topics Topics FAQs Infective Endocarditis En español Infective endocarditis is an infection of ... time, congestive heart failure (CHF). What causes infective endocarditis? The infection that leads to endocarditis can be ...

  2. Helminth infections among long-term-residents and settled immigrants in Qatar in the decade from 2005 to 2014: temporal trends and varying prevalence among subjects from different regional origins.

    Science.gov (United States)

    Abu-Madi, Marawan A; Behnke, Jerzy M; Boughattas, Sonia; Al-Thani, Asma; Doiphode, Sanjay H; Deshmukh, Anand

    2016-03-16

    Travel and migration from developing regions, where tropical diseases are common, to more developed industrialised nations can contribute to the introduction and subsequent spread of infections. With its rapidly expanding economy, Qatar has attracted vast numbers of immigrant workers in the last two decades, often from countries with poor socio-economic levels. Many used to arrive with patent intestinal parasitic infections. We analysed the prevalence of helminth infections in a dataset of 29,286 records of subjects referred for stool examination at the Hamad Medical Corporation over the course of a decade (2005 to 2014, inclusive). Overall prevalence of combined helminth infections was low (1.86 %) but there were significant temporal trends, age and sex effects and those arising from the region of origin of the subjects. The most common helminths were hookworms (overall prevalence 1.22 %), which accounted for 70.1 % of cases, and therefore patterns for combined helminth infections were largely driven by hookworms. In both cases, and also in Trichuris trichiura and Ascaris lumbricoides, prevalence peaked in 2008, since when prevalence has been steadily falling. Helminth infections were largely concentrated among subjects from five Asian countries (Nepal, Bangladesh, Sri Lanka, India and Pakistan), and there was a highly biased prevalence in favour of male subjects in all cases. Prevalence of all three nematodes peaked in age class 7 (mean age 25.5 years, range = 20-29) and there were significant interactions between region of origin, sex of subjects and prevalence of hookworms. These results offer optimism that prevalence will continue to decline in the years ahead, especially if control is targeted at those most at risk of carrying infections.

  3. Immune mechanisms in Babesia-infected animals

    International Nuclear Information System (INIS)

    Phillips, R.S.

    1980-01-01

    The course of a Babesia infection depends on the species of host and parasite involved. Animals infected with virulent babesias may need chemotherapy before acquired immunity develops. Maintenance of immunity is not dependent on the presence of the parasite. Babesia infections are characteristically of long duration. The immune response to babesias includes both humoral and cellular components. Antibody levels detected in serodiagnostic tests do not relate to levels of resistance to the parasite. Some antibodies, however, appear to be protective. Antiparasitic antibodies may damage parasites in or outside the red cell and act as opsonins. T-cell-deficient and anti-lymphocyte-serum-treated rodents are more susceptible to rodent piroplasms indicating a role for T-cells as either helper cells and/or as mediators of cell-mediated immunity (CMI). There is indirect evidence of CMI, but the cell-mediated mechanisms involved in parasite killing are not known. In domestic animals immunity is largely species- and strain-specific. Antigenic variation by babesias occurs. In rodents, however, there is cross-immunity between different species of rodent piroplasms and between rodent piroplasms and some malaria parasites. Prior infection with agents such as BCG, and Corynebacterium parvum, gives mice non-specific resistance to rodent piroplasms possibly mediated through a soluble non-antibody factor. This factor may also be liberated during piroplasm infections and by being toxic to malaria parasites account for heterologous immunity. Active immunization against babesias has been achieved with avirulent strains, irradiated parasites and dead parasites in adjuvant. During Babesia infections the primary and, to a lesser degree, the secondary immune response to heterologous antigens can be depressed. Maximum depression coincides with peak parasitaemia when antigen priming may be abolished completely. Immunosuppression during Babesia infections can prolong or exacerbate concurrent

  4. The burden of moderate-to-heavy soil-transmitted helminth infections among rural malaysian aborigines: an urgent need for an integrated control programme.

    Science.gov (United States)

    Ahmed, Abdulhamid; Al-Mekhlafi, Hesham M; Choy, Seow Huey; Ithoi, Init; Al-Adhroey, Abdulelah H; Abdulsalam, Awatif M; Surin, Johari

    2011-12-30

    Soil-transmitted helminth (STH) infections, among the most common neglected tropical diseases, continue to be a major threat to the health and socioeconomic wellbeing of infected people especially children in developing countries. A cross-sectional study among 254 aboriginal schoolchildren was conducted in order to determine the current prevalence and intensity of infections and to investigate the potential risk factors associated with moderate-to-heavy burden of STH infections among these children. Overall, 93.7% of children were found to be infected with one or more STH species. The prevalence of trichuriasis, ascariasis and hookworm infections were 84.6%, 47.6% and 3.9%, respectively. Almost half of the participants had heavy trichuriasis, one-quarter had heavy ascariasis whereas all hookworm infections were light infections. Overall, moderate-to-heavy STH infections accounted for 56.7% of the total infections. Univariate analysis revealed that those using untreated water supply (P = 0.013), living in houses without toilets (P = 0.027) and having domestic animals in the houses (P = 0.044) had significantly higher prevalence of moderate-to-heavy infections than others. Logistic regression analysis confirmed using untreated water for drinking (P = 0.001) and the absence of a toilet in the house (P = 0.003) as significant risk factors of moderate-to-heavy STH infections among these children. The high proportion of moderate-to-heavy STH infections further confirms the need for serious attention towards these devastating diseases that has put lives and the future of aboriginal children in jeopardy. Introduction of more poverty alleviation schemes, proper sanitation, provision of clean and safe drinking water, health education, as well as the introduction of periodic school-based deworming programmes are imperative among these communities in order to curtail the transmission and morbidity caused by STH.

  5. Lessons learned from implementation of a demonstration program to reduce the burden of anemia and hookworm in women in Yen Bai Province, Viet Nam

    Directory of Open Access Journals (Sweden)

    Thach Tran D

    2009-07-01

    Full Text Available Abstract Background Iron deficiency, anemia and hookworm disease are important public health problems for women of reproductive age living in developing countries and affect the health of newborns and infants. Iron supplementation and deworming treatment are effective in addressing these problems in both pregnant and non-pregnant women. Daily iron supplementation and deworming after the first trimester is recommended for pregnant women although these programs usually do not operate efficiently or effectively. Weekly iron-folic acid supplementation and regular deworming for non-pregnant women may be a viable approach for improving iron status and preventing anemia during the reproductive years. Addressing these diseases at a population level before women become pregnant could significantly improve women's health before and during pregnancy, as well as their infants' growth and development. Methods and Results This paper describes the major processes undertaken in a demonstration intervention of preventive weekly iron-folic acid supplementation with regular deworming for all 52,000 women aged 15–45 years in two districts of Yen Bai province, in northern Viet Nam. The intervention strategy included extensive consultation with community leaders and village, commune, district and provincial health staff, and training for village health workers. Distribution of the drugs was integrated with the existing health service infrastructure and the village health workers were the direct point of contact with women. Iron-folic acid tablets and deworming treatment were provided free of charge from May 2006. An independent Vietnamese NGO was commissioned to evaluate compliance and identify potential problems. The program resulted in effective distribution of iron-folic acid tablets and deworming treatment to all villages in the target districts, with full or partial compliance of 85%. Conclusion Training for health staff, the strong commitment of all partners

  6. Modulating Endoplasmic Reticulum-Golgi Cargo Receptors for Improving Secretion of Carrier-Fused Heterologous Proteins in the Filamentous Fungus Aspergillus oryzae

    Science.gov (United States)

    Hoang, Huy-Dung; Maruyama, Jun-ichi

    2014-01-01

    Filamentous fungi are excellent hosts for industrial protein production due to their superior secretory capacity; however, the yield of heterologous eukaryotic proteins is generally lower than that of fungal or endogenous proteins. Although activating protein folding machinery in the endoplasmic reticulum (ER) improves the yield, the importance of intracellular transport machinery for heterologous protein secretion is poorly understood. Here, using Aspergillus oryzae as a model filamentous fungus, we studied the involvement of two putative lectin-like cargo receptors, A. oryzae Vip36 (AoVip36) and AoEmp47, in the secretion of heterologous proteins expressed in fusion with the endogenous enzyme α-amylase as the carrier. Fluorescence microscopy revealed that mDsRed-tagged AoVip36 localized in the Golgi compartment, whereas AoEmp47 showed localization in both the ER and the Golgi compartment. Deletion of AoVip36 and AoEmp47 improved heterologous protein secretion, but only AoVip36 deletion had a negative effect on the secretion of α-amylase. Analysis of ER-enriched cell fractions revealed that AoVip36 and AoEmp47 were involved in the retention of heterologous proteins in the ER. However, the overexpression of each cargo receptor had a different effect on heterologous protein secretion: AoVip36 enhanced the secretion, whereas AoEmp47 promoted the intracellular retention. Taken together, our data suggest that AoVip36 and AoEmp47 hinder the secretion of heterologous proteins by promoting their retention in the ER but that AoVip36 also promotes the secretion of heterologous proteins. Moreover, we found that genetic deletion of these putative ER-Golgi cargo receptors significantly improves heterologous protein production. The present study is the first to propose that ER-Golgi transport is a bottleneck for heterologous protein production in filamentous fungi. PMID:25362068

  7. Soil transmitted helminths and schistosoma mansoni infections among school children in Zarima town, northwest Ethiopia.

    Science.gov (United States)

    Alemu, Abebe; Atnafu, Asmamaw; Addis, Zelalem; Shiferaw, Yitayal; Teklu, Takele; Mathewos, Biniam; Birhan, Wubet; Gebretsadik, Simon; Gelaw, Baye

    2011-07-09

    In Ethiopia, because of low quality drinking water supply and latrine coverage, helminths infections are the second most predominant causes of outpatient morbidity. Indeed, there is a scarcity of information on the prevalence of soil transmitted helminths and Schistosomiasis in Ethiopia, special in study area. Therefore, the aim of this study was to determine the prevalence and associated risk factors of soil transmitted helminths and intestinal Schistosomiasis. Cross-sectional study was conducted among 319 school children of Zarima town from April 1 to May 25, 2009. A pre-tested structured questionnaire was used to collect socio-demographic data and possible risk factors exposure. Early morning stool samples were collected and a Kato Katz semi concentration technique was used to examine and count parasitic load by compound light microscope. Data entry and analysis was done using SPSS-15 version and p-value transmitted helminths, Ascaris lumbricoides was the predominant isolate (22%) followed by Hookworms (19%) and Trichuris trichiura (2.5%). Schistosoma mansoni was also isolated in 37.9% of the study participants. Hookworm and S. mansoni infections showed statistically significant associations with shoe wearing and swimming habit of school children, respectively. Prevalence of soil transmitted helminths (STH) and S.mansoni was high and the diseases were still major health problem in the study area which alerts public health intervention as soon as possible.

  8. [High-level expression of heterologous protein based on increased copy number in Saccharomyces cerevisiae].

    Science.gov (United States)

    Zhang, Xinjie; He, Peng; Tao, Yong; Yang, Yi

    2013-11-04

    High-level expression system of heterologous protein mediated by internal ribosome entry site (IRES) in Saccharomyces cerevisiae was constructed, which could be used for other applications of S. cerevisiae in metabolic engineering. We constructed co-expression cassette (promoter-mCherry-TIF4631 IRES-URA3) containing promoters Pilv5, Padh2 and Ptdh3 and recombined the co-expression cassette into the genome of W303-1B-A. The URA3+ transformants were selected. By comparing the difference in the mean florescence value of mCherry in transformants, the effect of three promoters was detected in the co-expression cassette. The copy numbers of the interested genes in the genome were determined by Real-Time PCR. We analyzed genetic stability by continuous subculturing transformants in the absence of selection pressure. To verify the application of co-expression cassette, the ORF of mCherry was replaced by beta-galactosidase (LACZ) and xylose reductase (XYL1). The enzyme activities and production of beta-galactosidase and xylose reductase were detected. mCherry has been expressed in the highest-level in transformants with co-expression cassette containing Pilv5 promoter. The highest copy number of DNA fragment integrating in the genome was 47 in transformants containing Pilv5. The engineering strains showed good genetic stability. Xylose reductase was successfully expressed in the co-expression cassette containing Pilv5 promoter and TIF4631 IRES. The highest enzyme activity was 0. 209 U/mg crude protein in the transformants WIX-10. Beta-galactosidase was also expressed successfully. The transformants that had the highest enzyme activity was WIL-1 and the enzyme activity was 12.58 U/mg crude protein. The system mediated by Pilv5 promoter and TIF4631 IRES could express heterologous protein efficiently in S. cerevisiae. This study offered a new strategy for expression of heterologous protein in S. cerevisiae and provided sufficient experimental evidence for metabolic engineering

  9. Developing a xylanase XYNZG from Plectosphaerella cucumerina for baking by heterologously expressed in Kluyveromyces lactis.

    Science.gov (United States)

    Zhan, Fei Xiang; Wang, Qin Hong; Jiang, Si Jing; Zhou, Yu Ling; Zhang, Gui Min; Ma, Yan He

    2014-12-16

    Xylanase can replace chemical additives to improve the volume and sensory properties of bread in the baking. Suitable baking xylanase with improved yield will promote the application of xylanase in baking industry. The xylanase XYNZG from the Plectosphaerella cucumerina has been previously characterized by heterologous expression in Pichia pastoris. However, P. pastoris is not a suitable host for xylanase to be used in the baking process since P. pastoris does not have GRAS (Generally Regarded As Safe) status and requires large methanol supplement during the fermentation in most conditions, which is not allowed to be used in the food industry. Kluyveromyces lactis, as another yeast expression host, has a GRAS status, which has been successfully used in food and feed applications. No previous work has been reported concerning the heterologous expression of xylanase gene xynZG in K. lactis with an aim for application in baking. The xylanase gene xynZG from the P. cucumerina was heterologously expressed in K. lactis. The recombinant protein XYNZG in K. lactis presented an approximately 19 kDa band on SDS-PAGE and zymograms analysis. Transformant with the highest halo on the plate containing the RBB-xylan (Remazol Brilliant Blue-xylan) was selected for the flask fermentation in different media. The results indicated that the highest activity of 115 U/ml at 72 h was obtained with the YLPU medium. The mass spectrometry analysis suggested that the hydrolytic products of xylan by XYNZG were mainly xylobiose and xylotriose. The results of baking trials indicated that the addition of XYNZG could reduce the kneading time of dough, increase the volume of bread, improve the texture, and have more positive effects on the sensory properties of bread. Xylanase XYNZG is successfully expressed in K. lactis, which exhibits the highest activity among the published reports of the xylanase expression in K. lactis. The recombinant XYNZG can be used to improve the volume and sensory

  10. Efficacy of a high potency O1 Manisa monovalent vaccine against heterologous challenge with foot-and-mouth disease virus of O/SEA/Mya-98 lineage in sheep.

    Science.gov (United States)

    Singanallur, N B; Pacheco, J M; Arzt, J; Stenfeldt, C; Fosgate, G T; Rodriguez, L; Vosloo, W

    2017-09-01

    Potency tests for commercial oil-adjuvanted foot-and-mouth disease (FMD) vaccines are usually carried out in cattle, using a full dose (2 ml) of vaccine and homologous virus challenge. However, in sheep the recommended vaccine dose is half of the cattle dose (1 ml) and most vaccines have not been potency tested for this species, especially with heterologous viruses. To determine the efficacy of a high potency (>6PD 50 ) FMD virus (FMDV) O1Manisa vaccine in sheep, we carried out a study using a heterologous FMDV (FMDV O/SKR/2010 - Mya-98 strain) challenge. Groups of seven animals each were vaccinated with 2×, 1×, 1/2× or 1/4× dose (2 ml, 1 ml, 0.5 ml or 0.25 ml respectively) and challenged at 7 days post vaccination (dpv). Only 3 of the 7 sheep in the group vaccinated with 2 ml were protected. With 2 additional groups, receiving double or single doses and challenged at 14 dpv, 4 of 7 sheep were protected in each group. None of the sheep had measurable neutralising antibodies against the vaccine or challenge virus at 7 dpv. However, all vaccinated animals challenged at 14 dpv had a homologous neutralising response against FMDV O1 Manisa on the day of challenge and all but one animal also had a heterologous response to FMDV O/SKR/2010. Infectious FMDV and viral RNA could be found in nasal swabs between 1 and 6 days post challenge (dpc) in most vaccinated sheep, but those vaccinated with higher doses or challenged at 14 dpv showed significant decreases in the level of FMDV detection. Intermittent virus shedding was noticed between 1 and 35 dpc in all vaccinated groups, but persistent infection could be demonstrated only in 4 sheep (20%). This study showed that at the recommended dose, a high potency (>6 PD 50 ) FMDV O1Manisa vaccine does not protect sheep against a heterologous challenge at 7 dpv. However, partial protection was observed when a double dose was used at 7 dpv or when double or single dose vaccinated sheep were challenged at 14 dpv. Copyright

  11. Heterologous Immunological Effects of Early BCG Vaccination in Low-Birth-Weight Infants in Guinea-Bissau

    DEFF Research Database (Denmark)

    Jensen, Kristoffer Jarlov; Larsen, Nanna; Biering-Sørensen, Sofie

    2015-01-01

    or -7/8, or purified protein derivative (PPD). RESULTS:  Among 467 infants, BCG significantly increased the in vitro cytokine responses to purified protein derivative of Mycobacterium tuberculosis (PPD), as expected. BCG was also associated with increased responses to heterologous innate stimulation...

  12. LCR/MEL: A versatile system for high-level expression of heterologous proteins in erythroid cells.

    NARCIS (Netherlands)

    M. Needham; C. Gooding; K. Hudson; M. Antoniou (Michael); F.G. Grosveld (Frank); M. Hollis

    1992-01-01

    textabstractWe have used the human globin locus control region (LCR) to assemble an expression system capable of high-level, integration position-independent expression of heterologous genes and cDNAs in murine erythroleukaemia (MEL) cells. The cDNAs are inserted between the human beta-globin

  13. Heterologous Production of Cyanobacterial Mycosporine-Like Amino Acids Mycosporine-Ornithine and Mycosporine-Lysine in Escherichia coli

    Science.gov (United States)

    Katoch, Meenu; Mazmouz, Rabia; Chau, Rocky; Pearson, Leanne A.; Pickford, Russell

    2016-01-01

    ABSTRACT Mycosporine-like amino acids (MAAs) are an important class of secondary metabolites known for their protection against UV radiation and other stress factors. Cyanobacteria produce a variety of MAAs, including shinorine, the active ingredient in many sunscreen creams. Bioinformatic analysis of the genome of the soil-dwelling cyanobacterium Cylindrospermum stagnale PCC 7417 revealed a new gene cluster with homology to MAA synthase from Nostoc punctiforme. This newly identified gene cluster is unusual because it has five biosynthesis genes (mylA to mylE), compared to the four found in other MAA gene clusters. Heterologous expression of mylA to mylE in Escherichia coli resulted in the production of mycosporine-lysine and the novel compound mycosporine-ornithine. To our knowledge, this is the first time these compounds have been heterologously produced in E. coli and structurally characterized via direct spectral guidance. This study offers insight into the diversity, biosynthesis, and structure of cyanobacterial MAAs and highlights their amenability to heterologous production methods. IMPORTANCE Mycosporine-like amino acids (MAAs) are significant from an environmental microbiological perspective as they offer microbes protection against a variety of stress factors, including UV radiation. The heterologous expression of MAAs in E. coli is also significant from a biotechnological perspective as MAAs are the active ingredient in next-generation sunscreens. PMID:27520810

  14. Multi-omic profiling of EPO producing Chinese hamster ovary cell panel reveals metabolic adaptation to heterologous protein production

    DEFF Research Database (Denmark)

    Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

    Heterologous protein production in CHO cells imposes a burden on the host cell metabolism and impact cellular physiology on a global scale. In this work, a multi-omics approach was applied to characterize the physiological impact of erythropoietin production, and discover production bottlenecks, ...

  15. Multi-omic profiling of EPO-producing Chinese hamster ovary cell panel reveals metabolic adaptation to heterologous protein production

    DEFF Research Database (Denmark)

    Ley, Daniel; Kazemi Seresht, Ali; Engmark, Mikael

    2015-01-01

    Chinese hamster ovary (CHO) cells are the preferred production host for many therapeutic proteins. The production of heterologous proteins in CHO cells imposes a burden on the host cell metabolism and impact cellular physiology on a global scale. In this work, a multi-omics approach was applied...

  16. Mucosal vaccination with heterologous viral vectored vaccine targeting subdominant SIV accessory antigens strongly inhibits early viral replication

    DEFF Research Database (Denmark)

    Xu, Huanbin; Andersson, Anne-Marie Carola; Ragonnaud, Emeline

    2017-01-01

    Conventional HIV T cell vaccine strategies have not been successful in containing acute peak viremia, nor in providing long-term control. We immunized rhesus macaques intramuscularly and rectally using a heterologous adenovirus vectored SIV vaccine regimen encoding normally weakly immunogenic tat...

  17. Mutational analysis of the N-terminal topogenic signal of watermelon glyoxysomal malate dehydrogenase using the heterologous host Hansenula polymorpha

    NARCIS (Netherlands)

    Gietl, Christine; Faber, Klaas Nico; Klei, Ida J. van der; Veenhuis, Marten

    1994-01-01

    We have studied the significance of the N-terminal presequence of watermelon (Citrullus vulgaris) glyoxysomal malate dehydrogenase [gMDH; (S)-malate:NAD+ oxidoreductase; EC 1.1.1.37] in microbody targeting. The yeast Hansenula polymorpha was used as heterologous host for the in vivo expression of

  18. Engineering metabolic pathways in Amycolatopsis japonicum for the optimization of the precursor supply for heterologous brasilicardin congeners production

    Directory of Open Access Journals (Sweden)

    Paul N. Schwarz

    2018-03-01

    Full Text Available The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action, high potency and reduced toxicity compared to today's standard drugs. However, production of brasilicardin has been hampered since the producer strain Nocardia terpenica IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism. Previously, we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Amycolatopsis japonicum. Four brasilicardin congeners, intermediates of the BraA biosynthesis, were produced. Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization. Therefore, we used a metabolic engineering approach to increase heterologous production of brasilicardin in A. japonicum. Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate (IPP and to channel the precursor into the direction of diterpenoid biosynthesis. Both approaches contributed to an elevated heterologous production of the brasilicardin backbone, which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.

  19. BCG Vaccination Protects against Experimental Viral Infection in Humans through the Induction of Cytokines Associated with Trained Immunity

    NARCIS (Netherlands)

    Arts, Rob J W; Moorlag, Simone J C F M; Novakovic, Boris; Li, Yang; Wang, Shuang-Yin; Oosting, Marije; Kumar, Vinod; Xavier, Ramnik J; Wijmenga, Cisca; Joosten, Leo A B; Reusken, Chantal B E M; Benn, Christine S; Aaby, Peter; Koopmans, Marion P; Stunnenberg, Hendrik G; van Crevel, Reinout; Netea, Mihai G

    2018-01-01

    The tuberculosis vaccine bacillus Calmette-Guérin (BCG) has heterologous beneficial effects against non-related infections. The basis of these effects has been poorly explored in humans. In a randomized placebo-controlled human challenge study, we found that BCG vaccination induced genome-wide

  20. BCG Vaccination Protects against Experimental Viral Infection in Humans through the Induction of Cytokines Associated with Trained Immunity

    DEFF Research Database (Denmark)

    Arts, Rob J W; Moorlag, Simone J C F M; Novakovic, Boris

    2018-01-01

    The tuberculosis vaccine bacillus Calmette-Guérin (BCG) has heterologous beneficial effects against non-related infections. The basis of these effects has been poorly explored in humans. In a randomized placebo-controlled human challenge study, we found that BCG vaccination induced genome-wide ep...

  1. Combination of heterologous fibrin sealant and bioengineered human embryonic stem cells to improve regeneration following autogenous sciatic nerve grafting repair.

    Science.gov (United States)

    Mozafari, Roghayeh; Kyrylenko, Sergiy; Castro, Mateus Vidigal; Ferreira, Rui Seabra; Barraviera, Benedito; Oliveira, Alexandre Leite Rodrigues

    2018-01-01

    Peripheral nerve injury is a worldwide clinical problem, and the preferred surgical method for treating it is the end-to-end neurorrhaphy. When it is not possible due to a large nerve gap, autologous nerve grafting is used. However, these surgical techniques result in nerve regeneration at highly variable degrees. It is thus very important to seek complementary techniques to improve motor and sensory recovery. One promising approach could be cell therapy. Transplantation therapy with human embryonic stem cells (hESCs) is appealing because these cells are pluripotent and can differentiate into specialized cell types and have self-renewal ability. Therefore, the main objective of this study was to find conditions under which functional recovery is improved after sciatic nerve neurorrhaphy. We assumed that hESC, either alone or in combination with heterologous fibrin sealant scaffold, could be used to support regeneration in a mouse model of sciatic nerve injury and repair via autografting with end-to-end neurorrhaphy. Five millimeters of the sciatic nerve of C57BL/6 J mice were transected off and rotated 180 degrees to simulate an injury, and then stumps were sutured. Next, we applied heterologous fibrin sealant and/or human embryonic stem cells genetically altered to overexpress fibroblast growth factor 2 (FGF2) at the site of the injury. The study was designed to include six experimental groups comprising neurorrhaphy (N), neurorrhaphy + heterologous fibrin sealant (N + F), neurorrhaphy + heterologous fibrin sealant + doxycycline (N + F + D), neurorrhaphy + heterologous fibrin sealant + wild-type hESC (N + F + W), neurorrhaphy + heterologous fibrin sealant + hESC off (N + F + T), and neurorrhaphy + heterologous fibrin sealant + hESC on via doxycycline (N + F + D + T). We evaluated the recovery rate using Catwalk and von Frey functional recovery tests, as well as immunohistochemistry analysis. The experiments indicated that

  2. Nucleolytic degradation of homologous and heterologous deoxyribonucleic acid molecules at the surface of competent pneumococci

    International Nuclear Information System (INIS)

    Seto, H.; Lopez, R.; Garrigan, O.; Tomasz, A.

    1975-01-01

    Competent pneumococci can catalyze the rapid and quantitative degradation of extracellular deoxyribonucleic acid (DNA) molecules through the activity of surface-located nucleases (endo- and, possibly, exonucleases as well). Both homologous and heterologous DNAs are degraded by a mechanism that seems to involve a cyclic process: (i) attachment of DNA to the cell surface followed by (ii) nucleolytic attack, and (iii) release to the medium. Processes (ii) and (iii) are both inhibited by ethylenediaminetetraacetate. Whereas surface nuclease activity is specific for competent cells, the bulk of this activity is not coupled to irreversible DNA uptake (deoxyribonuclease-resistant binding). Pneumococcal DNA treated with ultraviolet irradiation or nitrous acid (cross-linking) is selectively impaired in the ability to irreversibly bind to competent cells, whereas reversible binding is normal. (U.S.)

  3. Production of isotopically labeled heterologous proteins in non-E. coli prokaryotic and eukaryotic cells

    International Nuclear Information System (INIS)

    Takahashi, Hideo; Shimada, Ichio

    2010-01-01

    The preparation of stable isotope-labeled proteins is necessary for the application of a wide variety of NMR methods, to study the structures and dynamics of proteins and protein complexes. The E. coli expression system is generally used for the production of isotope-labeled proteins, because of the advantages of ease of handling, rapid growth, high-level protein production, and low cost for isotope-labeling. However, many eukaryotic proteins are not functionally expressed in E. coli, due to problems related to disulfide bond formation, post-translational modifications, and folding. In such cases, other expression systems are required for producing proteins for biomolecular NMR analyses. In this paper, we review the recent advances in expression systems for isotopically labeled heterologous proteins, utilizing non-E. coli prokaryotic and eukaryotic cells.

  4. Heterologous overexpression of sfCherry fluorescent protein in Nannochloropsis salina

    Directory of Open Access Journals (Sweden)

    Nam Kyu Kang

    2015-12-01

    Full Text Available Oleaginous microalgae of the Nannochloropsis genus are considered excellent candidates for biofuels and value-added products owing to their high biomass productivity and lipid content. Here, we report the first overexpression and detection of a heterologous sfCherry fluorescent protein in Nannochloropsis salina in order to develop a transformation toolbox for future genetic improvements. Particle bombardment was employed for transformation, and expression of Shble under the control of TUB and UEP promoters, cloned from N. salina, was used to confer resistance to Zeocin antibiotics, resulting in 5.9 and 4.7 transformants per 108 cells, respectively. Stable integration of the markers into the genome was confirmed using a restriction enzyme site-directed amplification (RESDA PCR. The expression of sfCherry fluorescent protein was confirmed by Western blot analysis and confocal microscopy. These results suggest new possibilities of efficient genetic engineering of Nannochloropsis for the production of biofuels and other biochemicals.

  5. Phosphorylation of plant plasma membrane H+-ATPase by the heterologous host S. cerevisiae

    DEFF Research Database (Denmark)

    Rudashevskaya, Elena; Ye, Juanying; Young, Clifford

     It is known, that phosphorylation of both plant and yeast plasma membrane H+-ATPase results in enzyme activation or inhibition. Several sites at the regulatory C-terminus of the enzyme have been found to undergo phosphorylation in vivo in both plant and yeast. The C-termini of plant H...... of heterologous system of yeast cells, expressing plant proton pump. Therefore identification of possible regulatory effects by phosphorylation events in plant H+-ATPase in the system is significant. A number of putative phosphorylation sites at regulatory C-domain of H+-ATPase (AHA2) have been point...... functioning of the residues and suggests, that plant H+-ATPase could be regulated by phosphorylation at several sites being in yeast cells. Plant H+-ATPase purified from yeast cells by his-tag affinity chromatography was subjected to IMAC and TiO2 for enrichment of phosphopeptides. The phosphopeptides were...

  6. Application of image cytometry to characterize heterologous lipid flippases in yeast

    DEFF Research Database (Denmark)

    Jensen, Maria Stumph; Costa, Sara; Theorin, Lisa

    2016-01-01

    Lipid flippases are integral membrane proteins that play a central role in moving lipids across cellular membranes. Some of these transporters are ATPases that couple lipid translocation to ATP hydrolysis, whereas others function without any discernible metabolic energy input. A growing number...... is typically monitored by flow cytometry, a costly and maintenance-intensive method. Here, we have optimized a protocol to use an automated image-based cell counter to accurately measure lipid uptake by heterologous lipid flippases expressed in yeast. The method was validated by comparison with the classical...... for characterization of lipid flippase activity, and should be readily adaptable to analyze a variety of other transport systems in yeast, parasites, and mammalian cells. © 2016 International Society for Advancement of Cytometry....

  7. Streptomyces rimosus GDS(L Lipase: Production, Heterologous Overexpression and Structure-Stability Relationship

    Directory of Open Access Journals (Sweden)

    Marija Abramić

    2003-01-01

    Full Text Available Streptomyces rimosus lipase gene has been overexpressed in a heterologous host, S. lividans TK23. The maximal lipase activity was determined in the culture filtrates of the late stationary phase. Time course of lipase production was monitored by a modified plate assay. S. rimosus lipase gene has been located on the AseI B fragment approximately 2 Mb far from the left end of the S. rimosus linear chromosome. Out of eight examined streptomycetes, the presence of this rare type of bacterial lipase gene was detected in two belonging to the S. rimosus taxonomic cluster, and in one non-related species. Comparison of protein sequences of the Streptomyces lipolytic enzymes was performed. The result indicated the best structural stability of the putative S. coelicolor lipase-2.

  8. Cloning and heterologous expression of the antibiotic peptide (ABP) genes from Rhizopus oligosporus NBRC 8631.

    Science.gov (United States)

    Yamada, Osamu; Sakamoto, Kazutoshi; Tominaga, Mihoko; Nakayama, Tasuku; Koseki, Takuya; Fujita, Akiko; Akita, Osamu

    2005-03-01

    We carried out protein sequencing of purified Antibiotic Peptide (ABP), and cloned two genes encoding this peptide as abp1 and abp2, from Rhizopus oligosporus NBRC 8631. Both genes contain an almost identical 231-bp segment, with only 3 nucleotide substitutions, encoding a 77 amino acid peptide. The abp gene product comprises a 28 amino acid signal sequence and a 49 amino acid mature peptide. Northern blot analysis showed that at least one of the abp genes is transcribed in R. oligosporus NBRC 8631. A truncated form of abp1 encoding only the mature peptide was fused with the alpha-factor signal peptide and engineered for expression in Pichia pastoris SMD1168H. Culture broth of the recombinant Pichia displayed ABP activity against Bacillus subtilis NBRC 3335 after induction of heterologous gene expression. This result indicates that mature ABP formed the active structure without the aid of other factors from R. oligosporus, and was secreted.

  9. Process strategies to improve heterologous protein production in Escherichia coli under lactose or IPTG induction

    DEFF Research Database (Denmark)

    Kilikian, B. V.; Surarez, I. D.; Liria, C. W.

    2000-01-01

    Cells of Escherichia coli BL21 bearing the chicken muscle Troponin C (TnC) gene under the control of the lacUV5 promoter were induced under different cultivation conditions and the consequences on growth and cell protein content were investigated. The type of inducer molecule (lactose or IPTG...... per gram dry cell weight (DCW), was achieved when isopropyl-beta-D-thiogalactoside (IPTG) was the inducer. Under lactose induction, a value of 96 mg per gram DCW was attained. However, the high metabolic load imposed by IPTG, when compared with lactose induction, as assessed by the cell protein...... content and stability, indicates that lactose is probably the most appropriate inducer for the synthesis of this heterologous protein. (C) 2000 Elsevier Science Ltd. All rights reserved....

  10. Effects of introducing heterologous pathways on microbial metabolism with respect to metabolic optimality

    DEFF Research Database (Denmark)

    Kim, Hyun Uk; Kim, Byoungjin; Seung, Do Young

    2014-01-01

    reactions are more frequently introduced into various microbial hosts. The genome-scale metabolic simulations of Escherichia coli strains engineered to produce 1,4-butanediol, 1,3-propanediol, and amorphadiene suggest that microbial metabolism shows much different responses to the introduced heterologous...... reactions in a strain-specific manner than typical gene knockouts in terms of the energetic status (e.g., ATP and biomass generation) and chemical production capacity. The 1,4-butanediol and 1,3-propanediol producers showed greater metabolic optimality than the wild-type strains and gene knockout mutants...... for the energetic status, while the amorphadiene producer was metabolically less optimal. For the optimal chemical production capacity, additional gene knockouts were most effective for the strain producing 1,3-propanediol, but not for the one producing 1,4-butanediol. These observations suggest that strains having...

  11. Simian rhesus rotavirus is a unique heterologous (non-lapine) rotavirus strain capable of productive replication and horizontal transmission in rabbits.

    Science.gov (United States)

    Ciarlet, M; Estes, M K; Conner, M E

    2000-05-01

    Simian rhesus rotavirus (RRV) is the only identified heterologous (non-lapine) rotavirus strain capable of productive replication at a high inoculum dose of virus (>10(8) p.f.u.) in rabbits. To evaluate whether lower doses of RRV would productively infect rabbits and to obtain an estimate of the 50% infectious dose, rotavirus antibody-free rabbits were inoculated orally with RRV at inoculum doses of 10(3), 10(5) or 10(7) p.f.u. Based on faecal virus antigen or infectious virus shedding, RRV replication was observed with inoculum doses of 10(7) and 10(5) p.f.u., but not 10(3) p.f.u. Horizontal transmission of RRV to one of three mock-inoculated rabbits occurred 4-5 days after onset of virus antigen shedding in RRV-infected rabbits. Rabbits infected at 10(7) and 10(5), but not 10(3), p.f.u. of RRV developed rotavirus-specific immune responses and were completely (100%) protected from lapine ALA rotavirus challenge. These data confirm that RRV can replicate productively and spread horizontally in rabbits. In attempts to elucidate the genetic basis of the unusual replication efficacy of RRV in rabbits, the sequence of the gene encoding the lapine non-structural protein NSP1 was determined. Sequence analysis of the NSP1 of three lapine rotaviruses revealed a high degree of amino acid identity (85-88%) with RRV. Since RRV and lapine strains also share similar VP7s (96-97%) and VP4s (69-70%), RRV might replicate efficiently in rabbits because of the high relatedness of these three gene products, each implicated in host range restriction.

  12. α1B-Adrenergic Receptors Differentially Associate with Rab Proteins during Homologous and Heterologous Desensitization

    Science.gov (United States)

    Castillo-Badillo, Jean A.; Sánchez-Reyes, Omar B.; Alfonzo-Méndez, Marco A.; Romero-Ávila, M. Teresa; Reyes-Cruz, Guadalupe; García-Sáinz, J. Adolfo

    2015-01-01

    Internalization of G protein-coupled receptors can be triggered by agonists or by other stimuli. The process begins within seconds of cell activation and contributes to receptor desensitization. The Rab GTPase family controls endocytosis, vesicular trafficking, and endosomal fusion. Among their remarkable properties is the differential distribution of its members on the surface of various organelles. In the endocytic pathway, Rab 5 controls traffic from the plasma membrane to early endosomes, whereas Rab 4 and Rab 11 regulate rapid and slow recycling from early endosomes to the plasma membrane, respectively. Moreover, Rab 7 and Rab 9 regulate the traffic from late endosomes to lysosomes and recycling to the trans-Golgi. We explore the possibility that α1B-adrenergic receptor internalization induced by agonists (homologous) and by unrelated stimuli (heterologous) could involve different Rab proteins. This possibility was explored by Fluorescence Resonance Energy Transfer (FRET) using cells coexpressing α1B-adrenergic receptors tagged with the red fluorescent protein, DsRed, and different Rab proteins tagged with the green fluorescent protein. It was observed that when α1B-adrenergic receptors were stimulated with noradrenaline, the receptors interacted with proteins present in early endosomes, such as the early endosomes antigen 1, Rab 5, Rab 4, and Rab 11 but not with late endosome markers, such as Rab 9 and Rab 7. In contrast, sphingosine 1-phosphate stimulation induced rapid and transient α1B-adrenergic receptor interaction of relatively small magnitude with Rab 5 and a more pronounced and sustained one with Rab 9; interaction was also observed with Rab 7. Moreover, the GTPase activity of the Rab proteins appears to be required because no FRET was observed when dominant-negative Rab mutants were employed. These data indicate that α1B-adrenergic receptors are directed to different endocytic vesicles depending on the desensitization type (homologous vs

  13. Heterologous gene expression driven by carbonic anhydrase gene promoter in Dunaliella salina

    Science.gov (United States)

    Yurong, Chai; Yumin, Lu; Tianyun, Wang; Weihong, Hou; Lexun, Xue

    2006-12-01

    Dunaliella salina, a halotolerant unicellular green alga without a rigid cell wall, can live in salinities ranging from 0.05 to 5 mol/L NaCl. These features of D. salina make it an ideal host for the production of antibodies, oral vaccine, and commercially valuable polypeptides. To produce high level of heterologous proteins from D. salina, highly efficient promoters are required to drive expression of target genes under controlled condition. In the present study, we cloned a 5' franking region of 1.4 kb from the carbonic anhydrase ( CAH) gene of D. salina by genomic walking and PCR. The fragment was ligated to the pMD18-T vector and characterized. Sequence analysis indicated that this region contained conserved motifs, including a TATA- like box and CAAT-box. Tandem (GT)n repeats that had a potential role of transcriptional control, were also found in this region. The transcription start site (TSS) of the CAH gene was determined by 5' RACE and nested PCR method. Transformation assays showed that the 1.4 kb fragment was able to drive expression of the selectable bar (bialaphos resistance) gene when the fusion was transformed into D. salina by biolistics. Northern blotting hybridizations showed that the bar transcript was most abundant in cells grown in 2 mol/L NaCl, and less abundant in 0.5 mol/L NaCl, indicating that expression of the bar gene was induced at high salinity. These results suggest the potential use of the CAH gene promoter to induce the expression of heterologous genes in D. salina under varied salt condition.

  14. Imbalance of heterologous protein folding and disulfide bond formation rates yields runaway oxidative stress

    Directory of Open Access Journals (Sweden)

    Tyo Keith EJ

    2012-03-01

    Full Text Available Abstract Background The protein secretory pathway must process a wide assortment of native proteins for eukaryotic cells to function. As well, recombinant protein secretion is used extensively to produce many biologics and industrial enzymes. Therefore, secretory pathway dysfunction can be highly detrimental to the cell and can drastically inhibit product titers in biochemical production. Because the secretory pathway is a highly-integrated, multi-organelle system, dysfunction can happen at many levels and dissecting the root cause can be challenging. In this study, we apply a systems biology approach to analyze secretory pathway dysfunctions resulting from heterologous production of a small protein (insulin precursor or a larger protein (α-amylase. Results HAC1-dependent and independent dysfunctions and cellular responses were apparent across multiple datasets. In particular, processes involving (a degradation of protein/recycling amino acids, (b overall transcription/translation repression, and (c oxidative stress were broadly associated with secretory stress. Conclusions Apparent runaway oxidative stress due to radical production observed here and elsewhere can be explained by a futile cycle of disulfide formation and breaking that consumes reduced glutathione and produces reactive oxygen species. The futile cycle is dominating when protein folding rates are low relative to disulfide bond formation rates. While not strictly conclusive with the present data, this insight does provide a molecular interpretation to an, until now, largely empirical understanding of optimizing heterologous protein secretion. This molecular insight has direct implications on engineering a broad range of recombinant proteins for secretion and provides potential hypotheses for the root causes of several secretory-associated diseases.

  15. The Role of Heterologous Chloroplast Sequence Elements in Transgene Integration and Expression1[W][OA

    Science.gov (United States)

    Ruhlman, Tracey; Verma, Dheeraj; Samson, Nalapalli; Daniell, Henry

    2010-01-01

    Heterologous regulatory elements and flanking sequences have been used in chloroplast transformation of several crop species, but their roles and mechanisms have not yet been investigated. Nucleotide sequence identity in the photosystem II protein D1 (psbA) upstream region is 59% across all taxa; similar variation was consistent across all genes and taxa examined. Secondary structure and predicted Gibbs free energy values of the psbA 5′ untranslated region (UTR) among different families reflected this variation. Therefore, chloroplast transformation vectors were made for tobacco (Nicotiana tabacum) and lettuce (Lactuca sativa), with endogenous (Nt-Nt, Ls-Ls) or heterologous (Nt-Ls, Ls-Nt) psbA promoter, 5′ UTR and 3′ UTR, regulating expression of the anthrax protective antigen (PA) or human proinsulin (Pins) fused with the cholera toxin B-subunit (CTB). Unique lettuce flanking sequences were completely eliminated during homologous recombination in the transplastomic tobacco genomes but not unique tobacco sequences. Nt-Ls or Ls-Nt transplastomic lines showed reduction of 80% PA and 97% CTB-Pins expression when compared with endogenous psbA regulatory elements, which accumulated up to 29.6% total soluble protein PA and 72.0% total leaf protein CTB-Pins, 2-fold higher than Rubisco. Transgene transcripts were reduced by 84% in Ls-Nt-CTB-Pins and by 72% in Nt-Ls-PA lines. Transcripts containing endogenous 5′ UTR were stabilized in nonpolysomal fractions. Stromal RNA-binding proteins were preferentially associated with endogenous psbA 5′ UTR. A rapid and reproducible regeneration system was developed for lettuce commercial cultivars by optimizing plant growth regulators. These findings underscore the need for sequencing complete crop chloroplast genomes, utilization of endogenous regulatory elements and flanking sequences, as well as optimization of plant growth regulators for efficient chloroplast transformation. PMID:20130101

  16. The role of heterologous chloroplast sequence elements in transgene integration and expression.

    Science.gov (United States)

    Ruhlman, Tracey; Verma, Dheeraj; Samson, Nalapalli; Daniell, Henry

    2010-04-01

    Heterologous regulatory elements and flanking sequences have been used in chloroplast transformation of several crop species, but their roles and mechanisms have not yet been investigated. Nucleotide sequence identity in the photosystem II protein D1 (psbA) upstream region is 59% across all taxa; similar variation was consistent across all genes and taxa examined. Secondary structure and predicted Gibbs free energy values of the psbA 5' untranslated region (UTR) among different families reflected this variation. Therefore, chloroplast transformation vectors were made for tobacco (Nicotiana tabacum) and lettuce (Lactuca sativa), with endogenous (Nt-Nt, Ls-Ls) or heterologous (Nt-Ls, Ls-Nt) psbA promoter, 5' UTR and 3' UTR, regulating expression of the anthrax protective antigen (PA) or human proinsulin (Pins) fused with the cholera toxin B-subunit (CTB). Unique lettuce flanking sequences were completely eliminated during homologous recombination in the transplastomic tobacco genomes but not unique tobacco sequences. Nt-Ls or Ls-Nt transplastomic lines showed reduction of 80% PA and 97% CTB-Pins expression when compared with endogenous psbA regulatory elements, which accumulated up to 29.6% total soluble protein PA and 72.0% total leaf protein CTB-Pins, 2-fold higher than Rubisco. Transgene transcripts were reduced by 84% in Ls-Nt-CTB-Pins and by 72% in Nt-Ls-PA lines. Transcripts containing endogenous 5' UTR were stabilized in nonpolysomal fractions. Stromal RNA-binding proteins were preferentially associated with endogenous psbA 5' UTR. A rapid and reproducible regeneration system was developed for lettuce commercial cultivars by optimizing plant growth regulators. These findings underscore the need for sequencing complete crop chloroplast genomes, utilization of endogenous regulatory elements and flanking sequences, as well as optimization of plant growth regulators for efficient chloroplast transformation.

  17. Production of antibacterial peptide from bee venom via a new strategy for heterologous expression.

    Science.gov (United States)

    Hou, Chunsheng; Guo, Liqiong; Lin, Junfang; You, Linfeng; Wu, Wuhua

    2014-12-01

    Honey bee is important economic insect that not only pollinates fruits and crops but also provides products with various physiological activities. Bee venom is a functional agent that is widely applied in clinical treatment and pharmacy. Secapin is one of these agents that have a significant role in therapy. The functions of secapin from the bee venom have been documented, but little information is known about its heterologous expression under natural condition. Moreover, few scholars verified experimentally the functions of secapin from bee venom in vitro. In this study, we successfully constructed a heterologous expression vector, which is different from conventional expression system. A transgenic approach was established for transformation of secapin gene from the venom of Apis mellifera carnica (Ac-sec) into the edible fungi, Coprinus cinereus. Ac-sec was encoded by a 234 bp nucleotide that contained a signal peptide domain and two potential phosphorylation sites. The sequence exhibited highly homology with various secapins characterized from honey bee and related species. Southern blot data indicated that Ac-sec was present as single or multiple copy loci in the C. cinereus genome. By co-transformation and double-layer active assay, Ac-sec was expressed successfully in C. cinereus and the antibacterial activity of the recombinants was identified, showing notable antibacterial activities on different bacteria. Although Ac-sec is from the venom of Apidae, phylogenetic analysis demonstrated that Ac-sec was more closely related to that of Vespid than to bee species from Apidae. The molecular characteristics of Ac-sec and the potential roles of small peptides in biology were discussed.

  18. Heterologous production of Pseudomonas aeruginosa rhamnolipid under anaerobic conditions for microbial enhanced oil recovery.

    Science.gov (United States)

    Zhao, F; Shi, R; Zhao, J; Li, G; Bai, X; Han, S; Zhang, Y

    2015-02-01

    The ex situ application of rhamnolipid to enhance oil recovery is costly and complex in terms of rhamnolipid production and transportation, while in situ production of rhamnolipid is restricted by the oxygen-deficient environments of oil reservoirs. To overcome the oxygen-limiting conditions and to circumvent the complex regulation of rhamnolipid biosynthesis in Pseudomonas aeruginosa, an engineered strain Pseudomonas stutzeri Rhl was constructed for heterologous production of rhamnolipid under anaerobic conditions. The rhlABRI genes for rhamnolipid biosynthesis were cloned into a facultative anaerobic strain Ps. stutzeri DQ1 to construct the engineered strain Rhl. Anaerobic production of rhamnolipid was confirmed by thin layer chromatography and Fourier transform infrared analysis. Rhamnolipid product reduced the air-water surface tension to 30.3 mN m(-1) and the oil-water interfacial tension to 0.169 mN m(-1). Rhl produced rhamnolipid of 1.61 g l(-1) using glycerol as the carbon source. Rhl anaerobic culture emulsified crude oil up to EI24 ≈ 74. An extra 9.8% of original crude oil was displaced by Rhl in the core flooding test. Strain Rhl achieved anaerobic production of rhamnolipid and worked well for enhanced oil recovery in the core flooding model. The rhamnolipid produced by Rhl was similar to that of the donor strain SQ6. This is the first study to achieve anaerobic and heterologous production of rhamnolipid. Results demonstrated the potential feasibility of Rhl as a promising strain to enhance oil recovery through anaerobic production of rhamnolipid. © 2014 The Society for Applied Microbiology.

  19. Ligand-selective activation of heterologously-expressed mammalian olfactory receptor.

    Science.gov (United States)

    Ukhanov, K; Bobkov, Y; Corey, E A; Ache, B W

    2014-10-01

    Mammalian olfactory receptors (ORs) appear to have the capacity to couple to multiple G protein-coupled signaling pathways in a ligand-dependent selective manner. To better understand the mechanisms and molecular range of such ligand selectivity, we expressed the mouse eugenol OR (mOR-EG) in HEK293T cells together with Gα15 to monitor activation of the phospholipase-C (PLC) signaling pathway and/or Gαolf to monitor activation of the adenylate cyclase (AC) signaling pathway, resulting in intracellular Ca(2+) release and/or Ca(2+) influx through a cyclic nucleotide-gated channel, respectively. PLC-dependent responses differed dynamically from AC-dependent responses, allowing them to be distinguished when Gα15 and Gαolf were co-expressed. The dynamic difference in readout was independent of the receptor, the heterologous expression system, and the ligand concentration. Of 17 reported mOR-EG ligands tested, including eugenol, its analogs, and structurally dissimilar compounds (mousse cristal, nootkatone, orivone), some equally activated both signaling pathways, some differentially activated both signaling pathways, and some had no noticeable effect even at 1-5mM. Our findings argue that mOR-EG, when heterologously expressed, can couple to two different signaling pathways in a ligand selective manner. The challenge now is to determine the potential of mOR-EG, and perhaps other ORs, to activate multiple signaling pathways in a ligand selective manner in native ORNs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Heterologous expression of mlrA in a photoautotrophic host - Engineering cyanobacteria to degrade microcystins.

    Science.gov (United States)

    Dexter, Jason; Dziga, Dariusz; Lv, Jing; Zhu, Junqi; Strzalka, Wojciech; Maksylewicz, Anna; Maroszek, Magdalena; Marek, Sylwia; Fu, Pengcheng

    2018-06-01

    In this report, we establish proof-of-principle demonstrating for the first time genetic engineering of a photoautotrophic microorganism for bioremediation of naturally occurring cyanotoxins. In model cyanobacterium Synechocystis sp. PCC 6803 we have heterologously expressed Sphingopyxis sp. USTB-05 microcystinase (MlrA) bearing a 23 amino acid N-terminus secretion peptide from native Synechocystis sp. PCC 6803 PilA (sll1694). The resultant whole cell biocatalyst displayed about 3 times higher activity against microcystin-LR compared to a native MlrA host (Sphingomonas sp. ACM 3962), normalized for optical density. In addition, MlrA activity was found to be almost entirely located in the cyanobacterial cytosolic fraction, despite the presence of the secretion tag, with crude cellular extracts showing MlrA activity comparable to extracts from MlrA expressing E. coli. Furthermore, despite approximately 9.4-fold higher initial MlrA activity of a whole cell E. coli biocatalyst, utilization of a photoautotrophic chassis resulted in prolonged stability of MlrA activity when cultured under semi-natural conditions (using lake water), with the heterologous MlrA biocatalytic activity of the E. coli culture disappearing after 4 days, while the cyanobacterial host displayed activity (3% of initial activity) after 9 days. In addition, the cyanobacterial cell density was maintained over the duration of this experiment while the cell density of the E. coli culture rapidly declined. Lastly, failure to establish a stable cyanobacterial isolate expressing native MlrA (without the N-terminus tag) via the strong cpcB560 promoter draws attention to the use of peptide tags to positively modulate expression of potentially toxic proteins. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. The Interaction of Deworming, Improved Sanitation, and Household Flooring with Soil-Transmitted Helminth Infection in Rural Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jade Benjamin-Chung

    2015-12-01

    Full Text Available The combination of deworming and improved sanitation or hygiene may result in greater reductions in soil-transmitted helminth (STH infection than any single intervention on its own. We measured STH prevalence in rural Bangladesh and assessed potential interactions among deworming, hygienic latrines, and household finished floors.We conducted a cross-sectional survey (n = 1,630 in 100 villages in rural Bangladesh to measure three exposures: self-reported deworming consumption in the past 6 months, access to a hygienic latrine, and household flooring material. We collected stool samples from children 1-4 years, 5-12 years, and women 15-49 years. We performed mini-FLOTAC on preserved stool samples to detect Ascaris lumbricoides, Enterobius vermicularis, hookworm, and Trichuris trichiura ova. Approximately one-third (32% of all individuals and 40% of school-aged children had an STH infection. Less than 2% of the sample had moderate/heavy intensity infections. Deworming was associated with lower Ascaris prevalence (adjusted prevalence ratio (PR = 0.53; 95% CI 0.40, 0.71, but there was no significant association with hookworm (PR = 0.93, 95% CI 0.60, 1.44 or Trichuris (PR = 0.90, 95% CI 0.74, 1.08. PRs for hygienic latrine access were 0.91 (95% CI 0.67,1.24, 0.73 (95% CI 0.43,1.24, and 1.03 (95% CI 0.84,1.27 for Ascaris, hookworm, and Trichuris, respectively. Finished floors were associated with lower Ascaris prevalence (PR = 0.56, 95% CI 0.32, 0.97 but not associated with hookworm (PR = 0.48 95% CI 0.16,1.45 or Trichuris (PR = 0.98, 95% CI 0.72,1.33. Across helminths and combinations of exposures, adjusted prevalence ratios for joint exposures were consistently more protective than those for individual exposures.We found moderate STH prevalence in rural Bangladesh among children and women of childbearing age. This study is one of the first to examine independent and combined associations with deworming, sanitation, and hygiene. Our results suggest

  2. Prevalence of intestinal parasitic infections and associated risk factors among students at Dona Berber primary school, Bahir Dar, Ethiopia.

    Science.gov (United States)

    Hailegebriel, Tamirat

    2017-05-23

    Intestinal parasitic infections are still one of the major health concerns in developing countries. Monitoring of intestinal parasitic infection and associated risk factors are essential for intervention strategies. Therefore, the aim of this study was to assess the prevalence of intestinal parasitic infection and associated risk factors among students at Dona Berber primary school, Bahir Dar, Ethiopia. School based cross-sectional study was conducted among students at Dona Berber primary school from October 2015 to June 2016. Three hundred fifty nine students were involved in the study by providing stool specimens and detailed personal information. Students were selected by stratified and systematic random sampling method. Fresh stool samples were collected from each student and processed by formal-ether fecal concentration technique. Data were analyzed using SPSS version 20.0 statistical software and p value intestinal parasites. The rates of single and double parasitic infections among students were 49.6% and 16.2%, respectively. The most prevalent parasite detected in the study was E. histolytica/dispar (24.5%) followed by hookworm (22.8%). Among the different variables assessed in the study, family size of 6 (AOR = 4.90; 95% CI, 2.03-11.83), irregularly shoe wearing habit (AOR = 2.85; 95% CI, 1.53-5.32) and unclean finger nail (AOR = 3.68; 95% CI, 1.87-7.26) were independently predict intestinal parasitic infections. Student drinking well water (AOR = 2.51; 95% CI, 2.30-4.86) and unclean finger nail (AOR = 4.42; 95% CI, 2.55-7.65) were strongly associated with E. histolytica/dispar infection. Likewise, irregular shoe wearing habit (AOR = 14.13; 95% CI, 7.06-28.29) was strongly associated with hookworm infections. High prevalence of intestinal parasitic infection among the study participants demands improvement of health education, environmental sanitation and quality of water sources.

  3. A live attenuated cold-adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

    International Nuclear Information System (INIS)

    Joseph, Tomy; McAuliffe, Josephine; Lu, Bin; Vogel, Leatrice; Swayne, David; Jin, Hong; Kemble, George; Subbarao, Kanta

    2008-01-01

    The appearance of human infections caused by avian influenza A H7 subtype viruses underscores their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets when challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials

  4. Different levels of immunogenicity of two strains of Fowlpox virus as recombinant vaccine vectors eliciting T-cell responses in heterologous prime-boost vaccination strategies.

    Science.gov (United States)

    Cottingham, Matthew G; van Maurik, Andre; Zago, Manola; Newton, Angela T; Anderson, Richard J; Howard, M Keith; Schneider, Jörg; Skinner, Michael A

    2006-07-01

    The FP9 strain of F has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified V Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These "passage-specific" alterations are hypothesized to be involved in determining the immunogenicity of fowlpox virus as a recombinant vaccine vector.

  5. Closely-related Borrelia burgdorferi (sensu stricto) strains exhibit similar fitness in single infections and asymmetric competition in multiple infections.

    Science.gov (United States)

    Rynkiewicz, Evelyn C; Brown, Julia; Tufts, Danielle M; Huang, Ching-I; Kampen, Helge; Bent, Stephen J; Fish, Durland; Diuk-Wasser, Maria A

    2017-02-06

    Wild hosts are commonly co-infected with complex, genetically diverse, pathogen communities. Competition is expected between genetically or ecologically similar pathogen strains which may influence patterns of coexistence. However, there is little data on how specific strains of these diverse pathogen species interact within the host and how this impacts pathogen persistence in nature. Ticks are the most common disease vector in temperate regions with Borrelia burgdorferi, the causative agent of Lyme disease, being the most common vector-borne pathogen in North America. Borrelia burgdorferi is a pathogen of high public health concern and there is significant variation in infection phenotype between strains, which influences predictions of pathogen dynamics and spread. In a laboratory experiment, we investigated whether two closely-related strains of B. burgdorferi (sensu stricto) showed similar transmission phenotypes, how the transmission of these strains changed when a host was infected with one strain, re-infected with the same strain, or co-infected with two strains. Ixodes scapularis, the black-legged tick, nymphs were used to sequentially infect laboratory-bred Peromyscus leucopus, white-footed mice, with one strain only, homologous infection with the same stain, or heterologous infection with both strains. We used the results of this laboratory experiment to simulate long-term persistence and maintenance of each strain in a simple simulation model. Strain LG734 was more competitive than BL206, showing no difference in transmission between the heterologous infection groups and single-infection controls, while strain BL206 transmission was significantly reduced when strain LG734 infected first. The results of the model show that this asymmetry in competition could lead to extinction of strain BL206 unless there was a tick-to-host transmission advantage to this less competitive strain. This asymmetric competitive interaction suggests that strain identity and

  6. Immunogenicity and Protective Efficacy of Brugia malayi Heavy Chain Myosin as Homologous DNA, Protein and Heterologous DNA/Protein Prime Boost Vaccine in Rodent Model.

    Directory of Open Access Journals (Sweden)

    Jyoti Gupta

    Full Text Available We earlier demonstrated the immunoprophylactic efficacy of recombinant heavy chain myosin (Bm-Myo of Brugia malayi (B. malayi in rodent models. In the current study, further attempts have been made to improve this efficacy by employing alternate approaches such as homologous DNA (pcD-Myo and heterologous DNA/protein prime boost (pcD-Myo+Bm-Myo in BALB/c mouse model. The gene bm-myo was cloned in a mammalian expression vector pcDNA 3.1(+ and protein expression was confirmed in mammalian Vero cell line. A significant degree of protection (79.2%±2.32 against L3 challenge in pcD-Myo+Bm-Myo immunized group was observed which was much higher than that exerted by Bm-Myo (66.6%±2.23 and pcD-Myo (41.6%±2.45. In the heterologous immunized group, the percentage of peritoneal leukocytes such as macrophages, neutrophils, B cells and T cells marginally increased and their population augmented further significantly following L3 challenge. pcD-Myo+Bm-Myo immunization elicited robust cellular and humoral immune responses as compared to pcD-Myo and Bm-Myo groups as evidenced by an increased accumulation of CD4+, CD8+ T cells and CD19+ B cells in the mouse spleen and activation of peritoneal macrophages. Though immunized animals produced antigen-specific IgG antibodies and isotypes, sera of mice receiving pcD-Myo+Bm-Myo or Bm-Myo developed much higher antibody levels than other groups and there was profound antibody-dependent cellular adhesion and cytotoxicity (ADCC to B. malayi infective larvae (L3. pcD-Myo+Bm-Myo as well as Bm-Myo mice generated a mixed T helper cell phenotype as evidenced by the production of both pro-inflammatory (IL-2, IFN-γ and anti-inflammatory (IL-4, IL-10 cytokines. Mice receiving pcD-Myo on contrary displayed a polarized pro-inflammatory immune response. The findings suggest that the priming of animals with DNA followed by protein booster generates heightened and mixed pro- and anti-inflammatory immune responses that are capable of

  7. Heterologous Two-Dose Vaccination with Simian Adenovirus and Poxvirus Vectors Elicits Long-Lasting Cellular Immunity to Influenza Virus A in Healthy Adults

    Directory of Open Access Journals (Sweden)

    L. Coughlan

    2018-03-01

    Full Text Available Background: T-cell responses against highly conserved influenza antigens have been previously associated with protection. However, these immune responses are poorly maintained following recovery from influenza infection and are not boosted by inactivated influenza vaccines. We have previously demonstrated the safety and immunogenicity of two viral vectored vaccines, modified vaccinia virus Ankara (MVA and the chimpanzee adenovirus ChAdOx1 expressing conserved influenza virus antigens, nucleoprotein (NP and matrix protein-1 (M1. We now report on the safety and long-term immunogenicity of multiple combination regimes of these vaccines in young and older adults. Methods: We conducted a Phase I open-label, randomized, multi-center study in 49 subjects aged 18–46 years and 24 subjects aged 50 years or over. Following vaccination, adverse events were recorded and the kinetics of the T cell response determined at multiple time points for up to 18 months. Findings: Both vaccines were well tolerated. A two dose heterologous vaccination regimen significantly increased the magnitude of pre-existing T-cell responses to NP and M1 after both doses in young and older adults. The fold-increase and peak immune responses after a single MVA-NP + M1 vaccination was significantly higher compared to ChAdOx1 NP + M1. In a mixed regression model, T-cell responses over 18 months were significantly higher following the two dose vaccination regimen of MVA/ChAdOx1 NP + M1. Interpretation: A two dose heterologous vaccination regimen of MVA/ChAdOx1 NP + M1 was safe and immunogenic in young and older adults, offering a promising vaccination strategy for inducing long-term broadly cross-reactive protection against influenza A. Funding Source: Medical Research Council UK, NIHR BMRC Oxford. Keywords: Influenza, T-cell responses, Influenza vaccines, Viral vectors, Adults, Older adults

  8. Prevalence and effect of schistosome and soil-transmitted helminth infection on labour input in rice-growing communities of Ogun State, Nigeria

    Directory of Open Access Journals (Sweden)

    Sammy Olufemi Sam-Wobo

    2013-06-01

    Full Text Available Schistosomiasis and soil-transmitted helminthiasis (STH are public health problems in communities which lack basic social amenities with poor hygienic conditions. Studies were carried out to determine the prevalence and effect of schistosomes and soil-transmitted helminths infection on labour input on rice production in 9 rice-growing communities of Ogun State. Parasitological examinations of urine and faecal samples, and structured questionnaires were conducted on 243 consented individuals from May 2009 to March 2010. The results showed an overall prevalence of 17% for Ascaris lumbricoides, 12% for hookworms, 2% for Trichuris trichiura, 1% for Schistosoma haematobium and 1% for Schistosoma mansoni. A. lumbricoides and hookworms were more prevalent in Agbajege (25%, and varied in the other 8 communities. T. trichiura was prevalent in three communities, Agbajege (5%, Akodu (4.2%, and Moloko-Asipa (4.8 %; S. haematobium was prevalent only in Ayedere (2.6% and Lufoko (8%, while S. mansoni was prevalent only in Moloko-Asipa (9.5%. Infections among the gender were varied as 26.3 % of males and 33.8 % of females had an overall prevalence of: A. lumbricoides (16.8%, hookworms (11.8%, T. trichiura (1.6%, S. haematobium (1.1% and S. mansoni (1.1%. On frequency of infection to incapacitation per year, 45% of respondents were incapacitated 1-2 times, 27% 3-4 times and 19% were incapacitated more than 4 times. Understanding the effect of these two diseases will not only improve the health status of residents but also increase their productivity and ensure food security.

  9. Developing and evaluating health education learning package (HELP) to control soil-transmitted helminth infections among Orang Asli children in Malaysia.

    Science.gov (United States)

    Al-Delaimy, Ahmed K; Al-Mekhlafi, Hesham M; Lim, Yvonne A L; Nasr, Nabil A; Sady, Hany; Atroosh, Wahib M; Mahmud, Rohela

    2014-09-02

    This study was carried out to develop a health education learning package (HELP) about soil-transmitted helminth (STH) infections, and to evaluate what impact such a package could have in terms of reducing the incidence and intensity of STH infections among Orang Asli schoolchildren in Pahang, Malaysia. To identify the key risk factors of STH in Orang Asli communities, we applied an extensive mixed methods approach which involved an intensive literature review, as well as community-based discussions with children, their parents, teachers and health personnel, whilst also placing the children under direct observation. To evaluate the package, 317 children from two schools in Lipis, Pahang were screened for STH infections, treated by a 3-day course of albendazole and then followed up over the next 6 months. The knowledge of teachers, parents and children towards STH infections were assessed at baseline and after 3 months. The developed package consists of a half day workshop for teachers, a teacher's guide book to STH infections, posters, a comic book, a music video, a puppet show, drawing activities and an aid kit. The package was well-received with effective contributions being made by teachers, children and their parents. The incidence rates of hookworm infection at different assessment points were significantly lower among children in the intervention school compared to those in the control school. Similarly, the intensity of trichuriasis, ascariasis and hookworm infections were found to be significantly lower among children in the HELP group compared to those in the control group (P < 0.05). Moreover, the package significantly improved the knowledge, attitude and practices (KAP) of Orang Asli people and the knowledge of teachers towards STH infections. A school-based health education learning package (HELP) was developed which displayed a significant impact in terms of reducing the intensity of all three main STH infections, as well as in reducing the

  10. Adult population as potential reservoir of NTD infections in rural villages of Kwale district, Coastal Kenya: implications for preventive chemotherapy interventions policy.

    Science.gov (United States)

    Njenga, Sammy M; Mwandawiro, Charles S; Muniu, Erastus; Mwanje, Mariam T; Haji, Fatma M; Bockarie, Moses J

    2011-09-14

    Neglected tropical diseases (NTDs) are major public health problems in developing countries where they contribute to suffering of populations living in poor settings. As part of a research project started in September 2009 in Kwale district, Coast Region, Kenya, a baseline cross-sectional survey was conducted in 5 rural villages to provide information on the status of NTDs, including urinary schistosomiasis, soil-transmitted helminthiasis (STH), and lymphatic filariasis. This paper presents the results of a parasitological investigation among adults in the study villages. A total of 599 adults in the 5 study villages were tested for NTD infections in urine, stool and blood. The presence of Schistosoma haematobium infection was determined by the urine filtration method. The presence of STH in stool was determined by Kato-Katz method while filarial antigenaemia was determined using immunochromatographic (ICT) test. The study revealed high prevalence of hookworm (41.7%) and schistosomiasis (18.2%) infections among adults in the study villages. Of the 599 individuals examined, 50.1% had one or more helminthic infections. There was low level of polyparasitism with helminthic NTDs in the study population with 9.5% and 1.7% of the participants having two and three infections, respectively. In the current study, hookworm and schistosomiasis infections were identified as important infections among adults living in areas of high endemicity for these infections. Thus, if this section of the population is left untreated it may remain an important potential reservoir and a source of re-infection for school-age children treated in school deworming programmes. Therefore, there is a need to design novel strategies for preventive chemotherapy interventions that could allow inclusion of adults in an effort to reduce force of infection in high endemic communities.

  11. Complete Microbiota Engraftment Is Not Essential for Recovery from Recurrent Clostridium difficile Infection following Fecal Microbiota Transplantation

    Directory of Open Access Journals (Sweden)

    Christopher Staley

    2016-12-01

    Full Text Available Bacterial communities from subjects treated for recurrent Clostridium difficile infection (rCDI by fecal microbiota transplantation (FMT, using either heterologous donor stool samples or autologous stool samples, were characterized by Illumina next-generation sequencing. As previously reported, the success of heterologous FMT (90% was superior to that of autologous FMT (43% (P = 0.019, and post-FMT intestinal bacterial communities differed significantly between treatment arms (P < 0.001. Subjects cured by autologous FMT typically had greater abundances of the Clostridium XIVa clade and Holdemania bacteria prior to treatment, and the relative abundances of these groups increased significantly after FMT compared to heterologous FMT and pre-FMT samples. The typical shift to post-FMT, donor-like assemblages, featuring high relative abundances of genera within the Bacteroidetes and Firmicutes phyla, was not observed in the autologous FMT subjects. Autologous FMT patient bacterial communities were significantly different in composition than those for heterologous FMT patients and donors (P < 0.001. The SourceTracker program, which employs a Bayesian algorithm to determine source contributions to sink communities, showed that patients initially treated by heterologous FMT had significantly higher percentages of engraftment (i.e., similarity to donor communities, mean value of 74% compared to those who suffered recurrence following autologous FMT (1% (P ≤ 0.013. The findings of this study suggest that complete donor engraftment may be not necessary if functionally critical taxa are present in subjects following antibiotic therapy.

  12. Intestinal helminthic infections among elementary students of Babile town, eastern Ethiopia.

    Science.gov (United States)

    Tefera, Ephrem; Mohammed, Jemal; Mitiku, Habtamu

    2015-01-01

    Intestinal helminthic infections are important public health problems in developing countries. In Ethiopia, intestinal parasitic infections are highly prevalent because of low living standards and poor environmental sanitation. There are several areas in Ethiopia from which epidemiological information is lacking including Babile town. The aim of this study was to determine the prevalence of intestinal helminthic infection among students of Babile town. A cross sectional study was conducted from May 14 to June 08, 2012. Stool samples collected from 644 students were examined by the McMaster method. Data were analyzed using SPSS version 16.0. Univariate analysis was carried out using the Chi-square test to check for presence or absence of association between exposure and the presence of infection and odds ratios with 95% CI were computed to measure the strength of association. Logistic regression was used to calculate predictors of helminthic infection. Statistical significance was set at Pintestinal helminths was 13.8%, of which three students were infected with soil transmitted helminths with a prevalence rate of 0.47%. The prevalence of Hymenolepis nana, Enterobius vermicularis, hookworm, and Trichiura trichiura infections were 13, 0.6, 0.3, and 0.2% respectively. Intestinal helminthic infection was significantly associated with grade and sex of the school children. The prevalence of intestinal helminths was low. Health information dissemination is recommended. Since infection by Hymenolepis nana is a long term health problem in the area, provision of regular treatment by anthelminthic drug of choice for hymenolepiasis is also recommended.

  13. Impact of Helminth Infection during Pregnancy on Cognitive and Motor Functions of One-Year-Old Children

    Science.gov (United States)

    Mireku, Michael O.; Boivin, Michael J.; Davidson, Leslie L.; Ouédraogo, Smaïla; Koura, Ghislain K.; Alao, Maroufou J.; Massougbodji, Achille; Cot, Michel; Bodeau-Livinec, Florence

    2015-01-01

    Objective To determine the effect of helminth infection during pregnancy on the cognitive and motor functions of one-year-old children. Methods Six hundred and thirty five singletons born to pregnant women enrolled before 29 weeks of gestation in a trial comparing two intermittent preventive treatments for malaria were assessed for cognitive and motor functions using the Mullen Scales of Early Learning, in the TOVI study, at twelve months of age in the district of Allada in Benin. Stool samples of pregnant women were collected at recruitment, second antenatal care (ANC) visit (at least one month after recruitment) and just before delivery, and were tested for helminths using the Kato-Katz technique. All pregnant women were administered a total of 600 mg of mebendazole (100 mg two times daily for 3 days) to be taken after the first ANC visit. The intake was not directly observed. Results Prevalence of helminth infection was 11.5%, 7.5% and 3.0% at first ANC visit, second ANC visit and at delivery, respectively. Children of mothers who were infected with hookworms at the first ANC visit had 4.9 (95% CI: 1.3–8.6) lower mean gross motor scores compared to those whose mothers were not infected with hookworms at the first ANC visit, in the adjusted model. Helminth infection at least once during pregnancy was associated with infant cognitive and gross motor functions after adjusting for maternal education, gravidity, child sex, family possessions, and quality of the home stimulation. Conclusion Helminth infection during pregnancy is associated with poor cognitive and gross motor outcomes in infants. Measures to prevent helminth infection during pregnancy should be reinforced. PMID:25756357

  14. Comparison of individual and pooled stool samples for the assessment of intensity of Schistosoma mansoni and soil-transmitted helminth infections using the Kato-Katz technique.

    Science.gov (United States)

    Kure, Ashenafi; Mekonnen, Zeleke; Dana, Daniel; Bajiro, Mitiku; Ayana, Mio; Vercruysse, Jozef; Levecke, Bruno

    2015-09-24

    Our group has recently provided a proof-of-principle for the examination of pooled stool samples using McMaster technique as a strategy for the rapid assessment of intensity of soil-transmitted helminth infections (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm). In the present study we evaluated this pooling strategy for the assessment of intensity of both STH and Schistosoma mansoni infections using the Kato-Katz technique. A cross-sectional survey was conducted in 360 children aged 5-18 years from six schools in Jimma Zone (southwest Ethiopia). We performed faecal egg counts (FECs) in both individual and pooled samples (pools sizes of 5, 10 and 20) to estimate the number of eggs per gram of stool (EPG) using the Kato-Katz technique. We also assessed the time to screen both individual and pooled samples. Except for hookworms, there was a significant correlation (correlation coefficient = 0.53-0.95) between the mean of individual FECs and the FECs of pooled samples for A. lumbricoides, T. trichiura and S. mansoni, regardless of the pool size. Mean FEC were 2,596 EPG, 125 EPG, 47 EPG, and 41 EPG for A. lumbricoides, T. trichiura, S. mansoni and hookworm, respectively. There was no significant difference in FECs between the examination of individual and pooled stool samples, except for hookworms. For this STH, pools of 10 resulted in a significant underestimation of infection intensity. The total time to obtain individual FECs was 65 h 5 min. For pooled FECs, this was 19 h 12 min for pools of 5, 14 h 39 min for pools of 10 and 12 h 42 min for pools of 20. The results indicate that pooling of stool sample holds also promise as a rapid assessment of infections intensity for STH and S. mansoni using the Kato-Katz technique. In this setting, the time in the laboratory was reduced by 70 % when pools of 5 instead of individual stool samples were screened.

  15. Heterologous microarray experiments allow the identification of the early events associated with potato tuber cold sweetening

    Directory of Open Access Journals (Sweden)

    Vitulli Federico

    2008-04-01

    Full Text Available Abstract Background Since its discovery more than 100 years ago, potato (Solanum tuberosum tuber cold-induced sweetening (CIS has been extensively investigated. Several carbohydrate-associated genes would seem to be involved in the process. However, many uncertainties still exist, as the relative contribution of each gene to the process is often unclear, possibly as the consequence of the heterogeneity of experimental systems. Some enzymes associated with CIS, such as β-amylases and invertases, have still to be identified at a sequence level. In addition, little is known about the early events that trigger CIS and on the involvement/association with CIS of genes different from carbohydrate-associated genes. Many of these uncertainties could be resolved by profiling experiments, but no GeneChip is available for the potato, and the production of the potato cDNA spotted array (TIGR has recently been discontinued. In order to obtain an overall picture of early transcriptional events associated with CIS, we investigated whether the commercially-available tomato Affymetrix GeneChip could be used to identify which potato cold-responsive gene family members should be further studied in detail by Real-Time (RT-PCR (qPCR. Results A tomato-potato Global Match File was generated for the interpretation of various aspects of the heterologous dataset, including the retrieval of best matching potato counterparts and annotation, and the establishment of a core set of highly homologous genes. Several cold-responsive genes were identified, and their expression pattern was studied in detail by qPCR over 26 days. We detected biphasic behaviour of mRNA accumulation for carbohydrate-associated genes and our combined GeneChip-qPCR data identified, at a sequence level, enzymatic activities such as β-amylases and invertases previously reported as being involved in CIS. The GeneChip data also unveiled important processes accompanying CIS, such as the induction of redox

  16. Assembly/disassembly of a complex icosahedral virus to incorporate heterologous nucleic acids

    Science.gov (United States)

    Pascual, Elena; Mata, Carlos P.; Carrascosa, José L.; Castón, José R.

    2017-12-01

    Hollow protein containers are widespread in nature, and include virus capsids as well as eukaryotic and bacterial complexes. Protein cages are studied extensively for applications in nanotechnology, nanomedicine and materials science. Their inner and outer surfaces can be modified chemically or genetically, and the internal cavity can be used to template, store and/or arrange molecular cargos. Virus capsids and virus-like particles (VLP, noninfectious particles) provide versatile platforms for nanoscale bioengineering. Study of capsid protein self-assembly into monodispersed particles, and of VLP structure and biophysics is necessary not only to understand natural processes, but also to infer how these platforms can be redesigned to furnish novel functional VLP. Here we address the assembly dynamics of infectious bursal disease virus (IBDV), a complex icosahedral virus. IBDV has a ~70 nm-diameter T  =  13 capsid with VP2 trimers as the only structural subunits. During capsid assembly, VP2 is synthesized as a precursor (pVP2) whose C terminus is cleaved. The pVP2 C terminus has an amphipathic helix that controls VP2 polymorphism. In the absence of the VP3 scaffolding protein, necessary for control of assembly, 466/456-residue pVP2 intermediates bearing this helix assemble into VLP only when expressed with an N-terminal His6 tag (the HT-VP2-466 protein). HT-VP2-466 capsids are optimal for genetic insertion of proteins (cargo space ~78 000 nm3). We established an in vitro assembly/disassembly system of HT-VP2-466-based VLP for heterologous nucleic acid packaging and/or encapsulation of drugs and other molecules. HT-VP2-466 (empty) capsids were disassembled and reassembled by dialysis against low-salt/basic pH and high-salt/acid pH buffers, respectively, thus illustrating the reversibility in vitro of IBDV capsid assembly. HT-VP2-466 VLP also packed heterologous DNA by non-specific confinement during assembly. These and previous results establish the bases

  17. Structural Diversification of Lyngbyatoxin A by Host-Dependent Heterologous Expression of the tleABC Biosynthetic Gene Cluster.

    Science.gov (United States)

    Zhang, Lihan; Hoshino, Shotaro; Awakawa, Takayoshi; Wakimoto, Toshiyuki; Abe, Ikuro

    2016-08-03

    Natural products have enormous structural diversity, yet little is known about how such diversity is achieved in nature. Here we report the structural diversification of a cyanotoxin-lyngbyatoxin A-and its biosynthetic intermediates by heterologous expression of the Streptomyces-derived tleABC biosynthetic gene cluster in three different Streptomyces hosts: S. lividans, S. albus, and S. avermitilis. Notably, the isolated lyngbyatoxin derivatives, including four new natural products, were biosynthesized by crosstalk between the heterologous tleABC gene cluster and the endogenous host enzymes. The simple strategy described here has expanded the structural diversity of lyngbyatoxin A and its biosynthetic intermediates, and provides opportunities for investigation of the currently underestimated hidden biosynthetic crosstalk. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Hydrophobins in ectomycorrhizas: heterologous transcription of the Pisolithus HydPt-1 gene in yeast and Hebeloma cylindrosporum

    Directory of Open Access Journals (Sweden)

    D Tagu

    2009-12-01

    Full Text Available Hydrophobins are fungal cell wall proteins involved in aggregation of hyphae. Upon the development of the ectomycorrhizal symbiosis between tree roots and fungal hyphae, the transcripts of hydrophobin genes markedly accumulated. As the precise role of these proteins in symbiosis is not yet known, we develop heterologous expression system of the Pisolithus hydrophobin HYDPt-1. This gene has been introduced in Saccharomyces cerevisiae and in the ectomycorrhizal basidiomycete Hebeloma cylindrosporum. Introns were required for hydPt-1 transcript accumulation in the basidiomycete H. cylindrosporum. Heterologous transcript accumulation did not alter the phenotype of either species. The lack of altered phenotype resulted from the absence of HYDPt-1 polypeptide accumulation in transformed strains.

  19. Heterologous Expression of Membrane and Soluble Proteins Derepresses GCN4 mRNA Translation in the Yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Steffensen, L.; Pedersen, P. A.

    2006-01-01

    -ATPase also induced GCN4 translation. Derepression of GCN4 translation required phosphorylation of eIF-2 , the tRNA binding domain of Gcn2p, and the ribosome-associated proteins Gcn1p and Gcn20p. The increase in Gcn4p density in response to heterologous expression did not induce transcription from the HIS4...... promoter, a traditional Gcn4p target.......This paper describes the first physiological response at the translational level towards heterologous protein production in Saccharomyces cerevisiae. In yeast, the phosphorylation of eukaryotic initiation factor 2 (eIF-2 ) by Gcn2p protein kinase mediates derepression of GCN4 mRNA translation. Gcn4...

  20. Malignant pleural mesothelioma with heterologous osteoblastic differentiation: case report of the characteristic CT and bone scan findings

    International Nuclear Information System (INIS)

    Cho, Young Jun; Kim, Joung Sook; Kim, Ji Young; Choi, Soo Jeon; Choi, Sang Bong

    2008-01-01

    Malignant pleural mesothelioma is an uncommon neoplasm which is accompanied extremely rarely by osteoblastic heterologous elements. The CT manifestations of this tumor have been reported in several references. And, to our knowledge, only one case report provides a description of the bone scan findings. Here, we report the case of a rapidly progressing malignant pleural mesothelioma with heterologous osteoblastic elements. A CT scan reveals diffuse irregular pleural thickening and very coarse nodular calcifications along the right pleura and major fissure. A bone scan revealed an area of extensive increased radioactivity consistent with the pleural calcifications on the CT scan in the right hemithorax. A follow-up CT scan performed 40 days later suggests the presence of rapidly progressing nodular coarse calcifications

  1. Malignant pleural mesothelioma with heterologous osteoblastic differentiation: case report of the characteristic CT and bone scan findings

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Jun; Kim, Joung Sook; Kim, Ji Young; Choi, Soo Jeon; Choi, Sang Bong [Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    Malignant pleural mesothelioma is an uncommon neoplasm which is accompanied extremely rarely by osteoblastic heterologous elements. The CT manifestations of this tumor have been reported in several references. And, to our knowledge, only one case report provides a description of the bone scan findings. Here, we report the case of a rapidly progressing malignant pleural mesothelioma with heterologous osteoblastic elements. A CT scan reveals diffuse irregular pleural thickening and very coarse nodular calcifications along the right pleura and major fissure. A bone scan revealed an area of extensive increased radioactivity consistent with the pleural calcifications on the CT scan in the right hemithorax. A follow-up CT scan performed 40 days later suggests the presence of rapidly progressing nodular coarse calcifications.

  2. Heterologous Synthesis and Recovery of Advanced Biofuels from Bacterial Cell Factories.

    Science.gov (United States)

    Malik, Sana; Afzal, Ifrah; Mehmood, Muhammad Aamer; Al Doghaither, Huda; Rahimuddin, Sawsan Abdulaziz; Gull, Munazza; Nahid, Nazia

    2018-01-01

    Microbial engineering to produce advanced biofuels is currently the most encouraging approach in renewable energy. Heterologous synthesis of biofuels and other useful industrial chemicals using bacterial cell factories has radically diverted the attentions from the native synthesis of these compounds. However, recovery of biofuels from the media and cellular toxicity are the main hindrances to successful commercialization of advanced biofuels. Therefore, membrane transporter engineering is gaining increasing attentions from all over the world. The main objective of this review is to explore the ways to increase the microbial production of biofuels by counteracting the cellular toxicity and facilitating their easier recovery from media. Microbial synthesis of industrially viable compounds such as biofuels has been increased due to genomic revolution. Moreover, advancements in protein engineering, gene regulation, pathway portability, metabolic engineering and synthetic biology led the focus towards the development of robust and cost-effective systems for biofuel production. The most convenient way to combat cellular toxicity and to secrete biofuels is the use of membrane transport system. The use of membrane transporters is currently a serious oversight as do not involve chemical changes and contribute greatly to efflux biofuels in extracellular milieu. However, overexpression of transport systems can also be detrimental to cell, so, in future, structure-based engineering of transporters can be employed to evaluate optimum expression range, to increase biofuel specificity and transport rate through structural studies of biofuel molecules. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Identification and Heterologous Expression of Genes Involved in Anaerobic Dissimilatory Phosphite Oxidation by Desulfotignum phosphitoxidans▿

    Science.gov (United States)

    Simeonova, Diliana Dancheva; Wilson, Marlena Marie; Metcalf, William W.; Schink, Bernhard

    2010-01-01

    Desulfotignum phosphitoxidans is a strictly anaerobic, Gram-negative bacterium that utilizes phosphite as the sole electron source for homoacetogenic CO2 reduction or sulfate reduction. A genomic library of D. phosphitoxidans, constructed using the fosmid vector pJK050, was screened for clones harboring the genes involved in phosphite oxidation via PCR using primers developed based on the amino acid sequences of phosphite-induced proteins. Sequence analysis of two positive clones revealed a putative operon of seven genes predicted to be involved in phosphite oxidation. Four of these genes (ptxD-ptdFCG) were cloned and heterologously expressed in Desulfotignum balticum, a related strain that cannot use phosphite as either an electron donor or as a phosphorus source. The ptxD-ptdFCG gene cluster was sufficient to confer phosphite uptake and oxidation ability to the D. balticum host strain but did not allow use of phosphite as an electron donor for chemolithotrophic growth. Phosphite oxidation activity was measured in cell extracts of D. balticum transconjugants, suggesting that all genes required for phosphite oxidation were cloned. Genes of the phosphite gene cluster were assigned putative functions on the basis of sequence analysis and enzyme assays. PMID:20622064

  4. Identification and heterologous expression of genes involved in anaerobic dissimilatory phosphite oxidation by Desulfotignum phosphitoxidans.

    Science.gov (United States)

    Simeonova, Diliana Dancheva; Wilson, Marlena Marie; Metcalf, William W; Schink, Bernhard

    2010-10-01

    Desulfotignum phosphitoxidans is a strictly anaerobic, Gram-negative bacterium that utilizes phosphite as the sole electron source for homoacetogenic CO2 reduction or sulfate reduction. A genomic library of D. phosphitoxidans, constructed using the fosmid vector pJK050, was screened for clones harboring the genes involved in phosphite oxidation via PCR using primers developed based on the amino acid sequences of phosphite-induced proteins. Sequence analysis of two positive clones revealed a putative operon of seven genes predicted to be involved in phosphite oxidation. Four of these genes (ptxD-ptdFCG) were cloned and heterologously expressed in Desulfotignum balticum, a related strain that cannot use phosphite as either an electron donor or as a phosphorus source. The ptxD-ptdFCG gene cluster was sufficient to confer phosphite uptake and oxidation ability to the D. balticum host strain but did not allow use of phosphite as an electron donor for chemolithotrophic growth. Phosphite oxidation activity was measured in cell extracts of D. balticum transconjugants, suggesting that all genes required for phosphite oxidation were cloned. Genes of the phosphite gene cluster were assigned putative functions on the basis of sequence analysis and enzyme assays.

  5. Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

    Science.gov (United States)

    Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

    2012-01-01

    A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

  6. Heterologous protein secretion in Lactococcus lactis: a novel antigen delivery system

    Directory of Open Access Journals (Sweden)

    Langella P.

    1999-01-01

    Full Text Available Lactic acid bacteria (LAB are Gram-positive bacteria and are generally regarded as safe (GRAS organisms. Therefore, LAB could be used for heterologous protein secretion and they are good potential candidates as antigen delivery vehicles. To develop such live vaccines, a better control of protein secretion is required. We developed an efficient secretion system in the model LAB, Lactococcus lactis. Staphylococcal nuclease (Nuc was used as the reporter protein. We first observed that the quantity of secreted Nuc correlated with the copy number of the cloning vector. The nuc gene was cloned on a high-copy number cloning vector and no perturbation of the metabolism of the secreting strain was observed. Replacement of nuc native promoter by a strong lactococcal one led to a significant increase of nuc expression. Secretion efficiency (SE of Nuc in L. lactis was low, i.e., only 60% of the synthesized Nuc was secreted. Insertion of a synthetic propeptide between the signal peptide and the mature moiety of Nuc increased the SE of Nuc. On the basis of these results, we developed a secretion system and we applied it to the construction of an L. lactis strain which secretes a bovine coronavirus (BCV epitope-protein fusion (BCV-Nuc. BCV-Nuc was recognized by both anti-BCV and anti-Nuc antibodies. Secretion of this antigenic fusion is the first step towards the development of a novel antigen delivery system based on LAB-secreting strains.

  7. The pea SAD short-chain dehydrogenase/reductase: quinone reduction, tissue distribution, and heterologous expression.

    Science.gov (United States)

    Scherbak, Nikolai; Ala-Häivälä, Anneli; Brosché, Mikael; Böwer, Nathalie; Strid, Hilja; Gittins, John R; Grahn, Elin; Eriksson, Leif A; Strid, Åke

    2011-04-01

    The pea (Pisum sativum) tetrameric short-chain alcohol dehydrogenase-like protein (SAD) family consists of at least three highly similar members (SAD-A, -B, and -C). According to mRNA data, environmental stimuli induce SAD expression. The aim of this study was to characterize the SAD proteins by examining their catalytic function, distribution in pea, and induction in different tissues. In enzyme activity assays using a range of potential substrates, the SAD-C enzyme was shown to reduce one- or two-ring-membered quinones lacking long hydrophobic hydrocarbon tails. Immunological assays using a specific antiserum against the protein demonstrated that different tissues and cell types contain small amounts of SAD protein that was predominantly located within epidermal or subepidermal cells and around vascular tissue. Particularly high local concentrations were observed in the protoderm of the seed cotyledonary axis. Two bow-shaped rows of cells in the ovary and the placental surface facing the ovule also exhibited considerable SAD staining. Ultraviolet-B irradiation led to increased staining in epidermal and subepidermal cells of leaves and stems. The different localization patterns of SAD suggest functions both in development and in responses to environmental stimuli. Finally, the pea SAD-C promoter was shown to confer heterologous wound-induced expression in Arabidopsis (Arabidopsis thaliana), which confirmed that the inducibility of its expression is regulated at the transcriptional level.

  8. [Cloning, subcellular localization, and heterologous expression of ApNAC1 gene from Andrographis paniculata].

    Science.gov (United States)

    Wang, Jian; Qi, Meng-Die; Guo, Juan; Shen, Ye; Lin, Hui-Xin; Huang, Lu-Qi

    2017-03-01

    Andrographis paniculata is widely used as medicinal herb in China for a long time and andrographolide is its main medicinal constituent. To investigate the underlying andrographolide biosynthesis mechanisms, RNA-seq for A. paniculata leaves with MeJA treatment was performed. In A. paniculata transcriptomic data, the expression pattern of one member of NAC transcription factor family (ApNAC1) matched with andrographolide accumulation. The coding sequence of ApNAC1 was cloned by RT-PCR, and GenBank accession number was KY196416. The analysis of bioinformatics showed that the gene encodes a peptide of 323 amino acids, with a predicted relative molecular weight of 35.9 kDa and isoelectric point of 6.14. To confirm the subcellular localization, ApNAC1-GFP was transiently expressed in A. paniculata protoplast. The results indicated that ApNAC1 is a nucleus-localized protein. The analysis of real-time quantitative PCR revealed that ApNAC1 gene predominantly expresses in leaves. Compared with control sample, its expression abundance sharply increased with methyl jasmonate treatment. Based on its expression pattern, ApNAC1 gene might involve in andrographolide biosynthesis. ApNAC1 was heterologously expressed in Escherichia coli and recombinant protein was purified by Ni-NTA agarose. Further study will help us to understand the function of ApNAC1 in andrographolide biosynthesis. Copyright© by the Chinese Pharmaceutical Association.

  9. Heterología. La ciencia (imposible de los residuos violentos

    Directory of Open Access Journals (Sweden)

    Sergio Tonkonoft

    2015-01-01

    Full Text Available EI presente trabajo busca mostrar que en la obra de Bataille existe una teoría social general, articulada en torno a la noción de lo sagrado. Nuestra hipótesis es que Bataille profundizó y generalizó d movimiento iniciado por Durkheim, quien postula la sintaxis de lo sagrado arcaico como la parte fundamental de la gramática social, pero interpretando este legado a la luz del concepto de multitud, entendido como el otro nombre de la economía general de las pasiones colectivas. Para dlo, se sirvió de dementos deI psicoanálisis y la fenomenología alemana, produciendo la teoría original dd lazo social, su estructuración y sus dinâmicas, con las que reformuló la idea durkheimniana de lo sagrado y procedió a analizar los malestares de su época. Dada la antropología trágica que enmarcó esta empresa intelectual, resultó de ello la teoría social transgredida o imposible que lleva eI nombre de heterología.

  10. Heterologous expression of Pycnoporus cinnabarinus cellobiose dehydrogenase in Pichia pastoris and involvement in saccharification processes

    Directory of Open Access Journals (Sweden)

    Bey Mathieu

    2011-12-01

    Full Text Available Abstract Background Cellobiose dehydrogenase (CDH is an extracellular hemoflavoenzyme produced by lignocellulose-degrading fungi including Pycnoporus cinnabarinus. We investigated the cellulolytic system of P. cinnabarinus, focusing on the involvement of CDH in the deconstruction of lignocellulosic biomass. Results First, P. cinnabarinus growth conditions were optimized for CDH production. Following growth under cellulolytic conditions, the main components secreted were cellulases, xylanases and CDH. To investigate the contribution of P. cinnabarinus secretome in saccharification processes, the Trichoderma reesei enzymatic cocktail was supplemented with the P. cinnabarinus secretome. A significant enhancement of the degradation of wheat straw was observed with (i the production of a large amount of gluconic acid, (ii increased hemicellulose degradation, and (iii increased overall degradation of the lignocellulosic material. P. cinnabarinus CDH was heterologously expressed in Pichia pastoris to obtain large amounts of pure enzyme. In a bioreactor, the recombinant CDH (rCDH expression level reached 7800 U/L. rCDH exhibited values of biochemical parameters similar to those of the natural enzyme, and was able to bind cellulose despite the absence of a carbohydrate-binding module (CBM. Following supplementation of purified rCDH to T. reesei enzymatic cocktail, formation of gluconic acid and increased hemicellulose degradation were observed, thus confirming the previous results observed with P. cinnabarinus secretome. Conclusions We demonstrate that CDH offers an attractive tool for saccharification process enhancement due to gluconic acid production from raw lignocellulosic material.

  11. Heterologous expression of the Halothiobacillus neapolitanus carboxysomal gene cluster in Corynebacterium glutamicum.

    Science.gov (United States)

    Baumgart, Meike; Huber, Isabel; Abdollahzadeh, Iman; Gensch, Thomas; Frunzke, Julia

    2017-09-20

    Compartmentalization represents a ubiquitous principle used by living organisms to optimize metabolic flux and to avoid detrimental interactions within the cytoplasm. Proteinaceous bacterial microcompartments (BMCs) have therefore created strong interest for the encapsulation of heterologous pathways in microbial model organisms. However, attempts were so far mostly restricted to Escherichia coli. Here, we introduced the carboxysomal gene cluster of Halothiobacillus neapolitanus into the biotechnological platform species Corynebacterium gluta-micum. Transmission electron microscopy, fluorescence microscopy and single molecule localization microscopy suggested the formation of BMC-like structures in cells expressing the complete carboxysome operon or only the shell proteins. Purified carboxysomes consisted of the expected protein components as verified by mass spectrometry. Enzymatic assays revealed the functional production of RuBisCO in C. glutamicum both in the presence and absence of carboxysomal shell proteins. Furthermore, we could show that eYFP is targeted to the carboxysomes by fusion to the large RuBisCO subunit. Overall, this study represents the first transfer of an α-carboxysomal gene cluster into a Gram-positive model species supporting the modularity and orthogonality of these microcompartments, but also identified important challenges which need to be addressed on the way towards biotechnological application. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Metabolism of homologous and heterologous serum proteins in garter snakes (Thamnophis ordinoides)

    International Nuclear Information System (INIS)

    Leong, D.; Coe, J.E.

    1978-01-01

    The half-life (Tsub(1/2) of serum immunoglobulin (Ig) and albumin from snakes and mammals were determined in both garter snakes (Thamnophis ordinoides) and mice (Mus musculus). Metabolism of serum proteins in snakes was similar to mammalian protein metabolism in that homologous serum albumin had shorter Tsub(1/2) (16 days) than IgG (38 days). Also, reptilian and mammalian serum proteins had a relatively longer Tsub(1/2) when injected into closely related species. Thus mammalian serum Ig (rabbit gamma globulin (RGG)) had a shorter Tsub(1/2) (6.3 days) in snake than did homologous snake IgG (38 days), whereas in mice, RGG had a longer Tsub(1/2) (3.8 days) than snake Ig (0.9 days). Differences between metabolism of homologous and heterologous albumins were apparent only in snakes in which the Tsub(1/2) of homologous albumin was approximately 8-fold greater than mammalian albumin. These results indicate that metabolism of both Ig and albumin in snakes is regulated by specific receptors whereas albumin receptors have been difficult to demonstrate in mammals. The results of this study suggest that one of the factors determining the metabolism of a protein is its foreignness to the host perhaps because of receptor cross reactions. (author)

  13. Heterologous production of the stain solving peptidase PPP1 from Pleurotus pulmonarius.

    Science.gov (United States)

    Leonhardt, Robin-Hagen; Krings, Ulrich; Berger, Ralf G; Linke, Diana

    2016-05-01

    A novel stain solving subtilisin-like peptidase (PPP1) was identified from the culture supernatant of the agaricomycete Pleurotus pulmonarius. It was purified to homogeneity using a sequence of preparative isoelectric focusing, anion exchange and size exclusion chromatography. Peptides were identified by ab initio sequencing (nLC-ESI-QTOF-MS/MS), characterizing the enzyme as a member of the subtilase family (EC 3.4.21.X). An expression system was established featuring the pPIC9K vector, an alternative Kozak sequence, the codon optimized gene ppp1 gene without the native signal sequence with C-terminal hexa-histidine tag, and Pichia pastoris GS115 as expression host. Intracellular active enzyme was obtained from cultivations in shake flasks and in a five liter bioreactor. With reaction optima of 40 °C and a pH > 8.5, considerable bleaching of pre-stained fabrics (blood, milk and India ink), and the possibility of larger-scale production, the heterologous enzyme is well suitable for detergent applications, especially at lower temperatures as part of a more energy- and cost-efficient washing process. Showing little sequence similarity to other subtilases, this unique peptidase is the first subtilisin-like peptidase from Basidiomycota, which has been functionally produced in Pichia pastoris.

  14. Benchmarking two commonly used Saccharomyces cerevisiae strains for heterologous vanillin-β-glucoside production

    Directory of Open Access Journals (Sweden)

    Tomas Strucko

    2015-12-01

    Full Text Available The yeast Saccharomyces cerevisiae is a widely used eukaryotic model organism and a key cell factory for production of biofuels and wide range of chemicals. From the broad palette of available yeast strains, the most popular are those derived from laboratory strain S288c and the industrially relevant CEN.PK strain series. Importantly, in recent years these two strains have been subjected to comparative “-omics” analyzes pointing out significant genotypic and phenotypic differences. It is therefore possible that the two strains differ significantly with respect to their potential as cell factories for production of specific compounds. To examine this possibility, we have reconstructed a de novo vanillin-β-glucoside pathway in an identical manner in S288c and CEN.PK strains. Characterization of the two resulting strains in two standard conditions revealed that the S288c background strain produced up to 10-fold higher amounts of vanillin-β-glucoside compared to CEN.PK. This study demonstrates that yeast strain background may play a major role in the outcome of newly developed cell factories for production of a given product. Keywords: Yeast, Cell factory, Strain choice, Heterologous production, Vanillin-glucoside, Shikimate pathway

  15. Improved cellulolytic efficacy in Penicilium decumbens via heterologous expression of Hypocrea jecorina endoglucanase II

    Directory of Open Access Journals (Sweden)

    Qin Yuqi

    2013-01-01

    Full Text Available Hypocrea jecorina endoglucanase II (Hjegl2 was heterologously expressed in Penicillium decumbens (yielding strain Pd::Hjegl2. After induction in cellulose containing media, strain Pd::Hjeg2 displayed increased carboxymethylcellulase activity (CMCase, 5.77 IU/ml, representing a 21% increase and cellulose degradation determined with a filter paper assay (FPA, 0.40 IU/ml, 67% increase, as compared to the parent strain. In media supplemented with glucose (2%, Pd::Hjegl2, displayed 51.2-fold and 3-fold higher CMCase and FPA activities, respectively, as compared to the parent strain. No changes in the expression levels of the four main native cellulase genes of P. decumbens (Pdegl1, Pdegl2, Pdcbh1, and Pdcbh2 were noted between the transformant and wild-type strains. These data support the idea that Hjegl2 cleaves both internal and terminal glycosidic residues, in a relatively random and processive manner. In situ polyacrylamide gelactivity staining of extracts derived from wild-type and Pd::Hjegl2 revealed two additional active fractions in the latter strain; one with a molecular mass ~50-65 KDa and another ~80-116 kDa.

  16. Malignant Solitary Fibrous Tumor with Heterologous Rhabdomyosarcomatous Differentiation: A Case Report

    Directory of Open Access Journals (Sweden)

    Jeong-Hwa Kwon

    2017-03-01

    Full Text Available Malignant solitary fibrous tumor (MSFT is a well-described entity, from which heterologous differentiation is extremely rare. We encountered a case of MSFT with rhabdomyosarcomatous differentiation in a 56-year-old man. This patient presented with a large mass in his posterior thigh. He had been treated with chemoradiation for sarcoma involving the cervical spine, right femoral head, and both lungs 6 months earlier. A wide excision was performed. The mass measured 10.6 cm and showed a fish-flesh cut surface with necrotic foci. Microscopically, the tumor showed heterogeneous cellularity with a hemangiopericytic vascular pattern. A hypercellular area showed spindle cells or epithelioid cells with high mitotic activity (63/10 high-power fields and immunoreactivity for CD34 and CD99. A hypocellular area and a cystic area showed pleomorphic rhabdoid cells with immunoreactivity for desmin and myogenin. This is a report of a rare case of MSFT with rhabdomyosarcomatous differentiation and presents new histologic features of MSFT.

  17. Heterologous gln/asn-rich proteins impede the propagation of yeast prions by altering chaperone availability.

    Directory of Open Access Journals (Sweden)

    Zi Yang

    Full Text Available Prions are self-propagating conformations of proteins that can cause heritable phenotypic traits. Most yeast prions contain glutamine (Q/asparagine (N-rich domains that facilitate the accumulation of the protein into amyloid-like aggregates. Efficient transmission of these infectious aggregates to daughter cells requires that chaperones, including Hsp104 and Sis1, continually sever the aggregates into smaller "seeds." We previously identified 11 proteins with Q/N-rich domains that, when overproduced, facilitate the de novo aggregation of the Sup35 protein into the [PSI(+] prion state. Here, we show that overexpression of many of the same 11 Q/N-rich proteins can also destabilize pre-existing [PSI(+] or [URE3] prions. We explore in detail the events leading to the loss (curing of [PSI(+] by the overexpression of one of these proteins, the Q/N-rich domain of Pin4, which causes Sup35 aggregates to increase in size and decrease in transmissibility to daughter cells. We show that the Pin4 Q/N-rich domain sequesters Hsp104 and Sis1 chaperones away from the diffuse cytoplasmic pool. Thus, a mechanism by which heterologous Q/N-rich proteins impair prion propagation appears to be the loss of cytoplasmic Hsp104 and Sis1 available to sever [PSI(+].

  18. Laccase Gene Family in Cerrena sp. HYB07: Sequences, Heterologous Expression and Transcriptional Analysis

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2016-08-01

    Full Text Available Laccases are a class of multi-copper oxidases with industrial potential. In this study, eight laccases (Lac1–8 from Cerrena sp. strain HYB07, a white-rot fungus with high laccase yields, were analyzed. The laccases showed moderate identities to each other as well as with other fungal laccases and were predicted to have high redox potentials except for Lac6. Selected laccase isozymes were heterologously expressed in the yeast Pichia pastoris, and different enzymatic properties were observed. Transcription of the eight laccase genes was differentially regulated during submerged and solid state fermentation, as shown by quantitative real-time polymerase chain reaction and validated reference genes. During 6-day submerged fermentation, Lac7 and 2 were successively the predominantly expressed laccase gene, accounting for over 95% of all laccase transcripts. Interestingly, accompanying Lac7 downregulation, Lac2 transcription was drastically upregulated on days 3 and 5 to 9958-fold of the level on day 1. Consistent with high mRNA abundance, Lac2 and 7, but not other laccases, were identified in the fermentation broth by LC-MS/MS. In solid state fermentation, less dramatic differences in transcript abundance were observed, and Lac3, 7 and 8 were more highly expressed than other laccase genes. Elucidating the properties and expression profiles of the laccase gene family will facilitate understanding, production and commercialization of the fungal strain and its laccases.

  19. Heterologous expression and characterization of a new heme-catalase in Bacillus subtilis 168.

    Science.gov (United States)

    Philibert, Tuyishime; Rao, Zhiming; Yang, Taowei; Zhou, Junping; Huang, Genshu; Irene, Komera; Samuel, Niyomukiza

    2016-06-01

    Reactive oxygen species (ROS) is an inherent consequence to all aerobically living organisms that might lead to the cells being lethal and susceptible to oxidative stress. Bacillus pumilus is characterized by high-resistance oxidative stress that stimulated our interest to investigate the heterologous expression and characterization of heme-catalase as potential biocatalyst. Results indicated that recombinant enzyme significantly exhibited the high catalytic activity of 55,784 U/mg expressed in Bacillus subtilis 168 and 98.097 µmol/min/mg peroxidatic activity, the apparent K m of catalytic activity was 59.6 ± 13 mM with higher turnover rate (K cat = 322.651 × 10(3) s(-1)). The pH dependence of catalatic and peroxidatic activity was pH 7.0 and pH 4.5 respectively with temperature dependence of 40 °C and the recombinant heme-catalase exhibited a strong Fe(2+) preference. It was further revealed that catalase KatX2 improved the resistance oxidative stress of B. subtilis. These findings suggest that this B. pumilus heme-catalase can be considered among the industrially relevant biocatalysts due to its exceptional catalytic rate and high stability and it can be a potential candidate for the improvement of oxidative resistance of industrially produced strains.

  20. Biotechnological exploitation of Tetrapisispora phaffii killer toxin: heterologous production in Komagataella phaffii (Pichia pastoris).

    Science.gov (United States)

    Chessa, Rossella; Landolfo, Sara; Ciani, Maurizio; Budroni, Marilena; Zara, Severino; Ustun, Murat; Cakar, Zeynep Petek; Mannazzu, Ilaria

    2017-04-01

    The use of natural antimicrobials from plants, animals and microorganisms to inhibit the growth of pathogenic and spoilage microorganisms is becoming more frequent. This parallels the increased consumer interest towards consumption of minimally processed food and 'greener' food and beverage additives. Among the natural antimicrobials of microbial origin, the killer toxin produced by the yeast Tetrapisispora phaffii, known as Kpkt, appears to be a promising natural antimicrobial agent. Kpkt is a glycoprotein with β-1,3-glucanase and killer activity, which induces ultrastructural modifications to the cell wall of yeast of the genera Kloeckera/Hanseniaspora and Zygosaccharomyces. Moreover, Kpkt maintains its killer activity in grape must for at least 14 days under winemaking conditions, thus suggesting its use against spoilage yeast in wine making and the sweet beverage industry. Here, the aim was to explore the possibility of high production of Kpkt for biotechnological exploitation. Molecular tools for heterologous production of Kpkt in Komagataella phaffii GS115 were developed, and two recombinant clones that produce up to 23 mg/L recombinant Kpkt (rKpkt) were obtained. Similar to native Kpkt, rKpkt has β-glucanase and killer activities. Moreover, it shows a wider spectrum of action with respect to native Kpkt. This includes effects on Dekkera bruxellensis, a spoilage yeast of interest not only in wine making, but also for the biofuel industry, thus widening the potential applications of this rKpkt.

  1. Engineering multifunctional protein nanoparticles by in vitro disassembling and reassembling of heterologous building blocks

    Science.gov (United States)

    Unzueta, Ugutz; Serna, Naroa; Sánchez-García, Laura; Roldán, Mónica; Sánchez-Chardi, Alejandro; Mangues, Ramón; Villaverde, Antonio; Vázquez, Esther

    2017-12-01

    The engineering of protein self-assembling at the nanoscale allows the generation of functional and biocompatible materials, which can be produced by easy biological fabrication. The combination of cationic and histidine-rich stretches in fusion proteins promotes oligomerization as stable protein-only regular nanoparticles that are composed by a moderate number of building blocks. Among other applications, these materials are highly appealing as tools in targeted drug delivery once empowered with peptidic ligands of cell surface receptors. In this context, we have dissected here this simple technological platform regarding the controlled disassembling and reassembling of the composing building blocks. By applying high salt and imidazole in combination, nanoparticles are disassembled in a process that is fully reversible upon removal of the disrupting agents. By taking this approach, we accomplish here the in vitro generation of hybrid nanoparticles formed by heterologous building blocks. This fact demonstrates the capability to generate multifunctional and/or multiparatopic or multispecific materials usable in nanomedical applications.

  2. Induction of divalent cation permeability by heterologous expression of a voltage sensor domain.

    Science.gov (United States)

    Arima, Hiroki; Tsutsui, Hidekazu; Sakamoto, Ayako; Yoshida, Manabu; Okamura, Yasushi

    2018-01-06

    The voltage sensor domain (VSD) is a protein domain that confers sensitivity to membrane potential in voltage-gated ion channels as well as the voltage-sensing phosphatase. Although VSDs have long been considered to function as regulatory units acting on adjacent effectors, recent studies have revealed the existence of direct ion permeation paths in some mutated VSDs and in the voltage-gated proton channel. In this study, we show that calcium currents are evoked upon membrane hyperpolarization in cells expressing a VSD derived from an ascidian voltage-gated ion channel superfamily. Unlike the previously reported omega-pore in the Shaker K + channel and rNav1.4, mutations are not required. From electrophysiological experiments in heterologous expression systems, we found that the conductance is directly mediated by the VSD itself and is carried by both monovalent and divalent cations. This is the first report of divalent cation permeation through a VSD-like structure. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Heterologous production of human papillomavirus type-16 L1 protein by a lactic acid bacterium

    Directory of Open Access Journals (Sweden)

    Bermúdez-Humarán Luis G

    2009-08-01

    Full Text Available Abstract Background The expression of vaccine antigens in lactic acid bacteria (LAB is a safe and cost-effective alternative to traditional expression systems. In this study, we investigated i the expression of Human papillomavirus type 16 (HPV-16 L1 major capsid protein in the model LAB Lactococcus lactis and ii the ability of the resulting recombinant strain to produce either capsomer-or virus-like particles (VLPs. Results and conclusion HPV-16 L1 gene was cloned into two vectors, pCYT and pSEC, designed for controlled intra- or extracellular heterologous expression in L. lactis, respectively. The capacity of L. lactis harboring either pCYT:L1 or pSEC:L1 plasmid to accumulate L1 in the cytoplasm and supernatant samples was confirmed by Western blot assays. Electron microscopy analysis suggests that, L1 protein produced by recombinant lactococci can self-assemble into structures morphologically similar to VLPs intracellularly. The presence of conformational epitopes on the L. lactis-derived VLPs was confirmed by ELISA using an anti-HPV16 L1 capsid antigen antibody. Our results support the feasibility of using recombinant food-grade LAB, such as L. lactis, for the production of L1-based VLPs and open the possibility for the development of a new safe mucosal vector for HPV-16 prophylactic vaccination.

  4. A heterologous radioimmunoassay for avian prolactin: Application to the measurement of prolactin in the turkey

    International Nuclear Information System (INIS)

    McNeilly, A.S.; Etches, R.J.; Friesen, H.G.

    1978-01-01

    A specific heterologous double-antibody radioimmunoassay has been developed to measure turkey prolactin (PRL) using a guinea pig anti-hPRL antiserum and 125 I-labelled ovine PRL [ 125 I]oPRL. Turkey pituitary prolactin and serum give parallel dose-response curves and no cross-rection is seen with turkey growth hormone, LH or FSH, or mammalian LH, FSH, TSH, GH or placental lactogens. The RIA is accurate and precise and is sufficiently sensitive to measure PRL in all physiological situations investigated in the turkey. The RIA will measure PRL in several avian species including the chicken, duck, goose, pheasant, pheasant x chicken F 1 hybrid, pigeon, quail, and rook. Plasma PRL concentrations in laying and broody turkey hens were not significantly different (46.5 +- 2.5 vs. 39.7 +- 3.8 ng/ml) but both were significantly higher (P < 0.001) than in non-laying turkey hens (4.6 +- 0.7 ng/ml). Oestradiol injection into laying hens did not alter PRL levels while the same injection in non-laying hens caused a significant three-fold increse in plasma PRL levels. (author)

  5. Overexpression of pucC improves the heterologous protein expression level in a Rhodobacter sphaeroides expression system.

    Science.gov (United States)

    Cheng, L; Chen, G; Ding, G; Zhao, Z; Dong, T; Hu, Z

    2015-04-27

    The Rhodobacter sphaeroides system has been used to express membrane proteins. However, its low yield has substantially limited its application. In order to promote the protein expression capability of this system, the pucC gene, which plays a crucial role in assembling the R. sphaeroides light-harvesting 2 complex (LH2), was overexpressed. To build a pucC overexpression strain, a pucC overexpression vector was constructed and transformed into R. sphaeroides CQU68. The overexpression efficiency was evaluated by quantitative real-time polymerase chain reaction. A well-used reporter β-glucuronidase (GUS) was fusion-expressed with LH2 to evaluate the heterologous protein expression level. As a result, the cell culture and protein in the pucC overexpression strain showed much higher typical spectral absorption peaks at 800 and 850 nm compared with the non-overexpression strain, suggesting a higher expression level of LH2-GUS fusion protein in the pucC overexpression strain. This result was further confirmed by Western blot, which also showed a much higher level of heterologous protein expression in the pucC overexpression strain. We further compared GUS activity in pucC overexpression and non-overexpression strains, the results of which showed that GUS activity in the pucC overexpression strain was approximately ten-fold that in the non-overexpression strain. These results demonstrate that overexpressed pucC can promote heterologous protein expression levels in R. sphaeroides.

  6. Transcriptome analysis in non-model species: a new method for the analysis of heterologous hybridization on microarrays

    Directory of Open Access Journals (Sweden)

    Jouventin Pierre

    2010-05-01

    Full Text Available Abstract Background Recent developments in high-throughput methods of analyzing transcriptomic profiles are promising for many areas of biology, including ecophysiology. However, although commercial microarrays are available for most common laboratory models, transcriptome analysis in non-traditional model species still remains a challenge. Indeed, the signal resulting from heterologous hybridization is low and difficult to interpret because of the weak complementarity between probe and target sequences, especially when no microarray dedicated to a genetically close species is available. Results We show here that transcriptome analysis in a species genetically distant from laboratory models is made possible by using MAXRS, a new method of analyzing heterologous hybridization on microarrays. This method takes advantage of the design of several commercial microarrays, with different probes targeting the same transcript. To illustrate and test this method, we analyzed the transcriptome of king penguin pectoralis muscle hybridized to Affymetrix chicken microarrays, two organisms separated by an evolutionary distance of approximately 100 million years. The differential gene expression observed between different physiological situations computed by MAXRS was confirmed by real-time PCR on 10 genes out of 11 tested. Conclusions MAXRS appears to be an appropriate method for gene expression analysis under heterologous hybridization conditions.

  7. Comparison of secretory signal peptides for heterologous protein expression in microalgae: Expanding the secretion portfolio for Chlamydomonas reinhardtii.

    Directory of Open Access Journals (Sweden)

    João Vitor Dutra Molino

    Full Text Available Efficient protein secretion is a desirable trait for any recombinant protein expression system, together with simple, low-cost, and defined media, such as the typical media used for photosynthetic cultures of microalgae. However, low titers of secreted heterologous proteins are usually obtained, even with the most extensively studied microalga Chlamydomonas reinhardtii, preventing their industrial application. In this study, we aimed to expand and evaluate secretory signal peptides (SP for heterologous protein secretion in C. reinhardtii by comparing previously described SP with untested sequences. We compared the SPs from arylsulfatase 1 and carbonic anhydrase 1, with those of untried SPs from binding protein 1, an ice-binding protein, and six sequences identified in silico. We identified over 2000 unique SPs using the SignalP 4.0 software. mCherry fluorescence was used to compare the protein secretion of up to 96 colonies for each construct, non-secretion construct, and parental wild-type cc1690 cells. Supernatant fluorescence varied according to the SP used, with a 10-fold difference observed between the highest and lowest secretors. Moreover, two SPs identified in silico secreted the highest amount of mCherry. Our results demonstrate that the SP should be carefully selected and that efficient sequences can be coded in the C. reinhardtii genome. The SPs described here expand the portfolio available for research on heterologous protein secretion and for biomanufacturing applications.

  8. Disruption of ten protease genes in the filamentous fungus Aspergillus oryzae highly improves production of heterologous proteins.

    Science.gov (United States)

    Yoon, Jaewoo; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

    2011-02-01

    Proteolytic degradation by secreted proteases into the culture medium is one of the significant problems to be solved in heterologous protein production by filamentous fungi including Aspergillus oryzae. Double (tppA, and pepE) and quintuple (tppA, pepE, nptB, dppIV, and dppV) disruption of protease genes enhanced human lysozyme (HLY) and bovine chymosin (CHY) production by A. oryzae. In this study, we used a quintuple protease gene disruptant and performed successive rounds of disruption for five additional protease genes (alpA, pepA, AopepAa, AopepAd, and cpI), which were previously investigated by DNA microarray analyses for their expression. Gene disruption was performed by pyrG marker recycling with a highly efficient gene-targeting background (∆ligD) as previously reported. As a result, the maximum yields of recombinant CHY and HLY produced by a decuple protease gene disruptant were approximately 30% and 35%, respectively, higher than those produced by a quintuple protease gene disruptant. Thus, we successfully constructed a decuple protease gene disruptant possessing highly improved capability of heterologous protein production. This is the first report on decuple protease gene disruption that improved the levels of heterologous protein production by the filamentous fungus A. oryzae.

  9. Improved heterologous protein production by a tripeptidyl peptidase gene (AosedD) disruptant of the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Zhu, Lin; Nemoto, Takeshi; Yoon, Jaewoo; Maruyama, Jun-ichi; Kitamoto, Katsuhiko

    2012-01-01

    Proteolytic degradation is one of the serious bottlenecks limiting the yields of heterologous protein production by Aspergillus oryzae. In this study, we selected a tripeptidyl peptidase gene AosedD (AO090166000084) as a candidate potentially degrading the heterologous protein, and performed localization analysis of the fusion protein AoSedD-EGFP in A. oryzae. As a result, the AoSedD-EGFP was observed in the septa and cell walls as well as in the culture medium, suggesting that AoSedD is a secretory enzyme. An AosedD disruptant was constructed to investigate an effect of AoSedD on the production level of heterologous proteins and protease activity. Both of the total protease and tripeptidyl peptidase activities in the culture medium of the AosedD disruptant were decreased as compared to those of the control strain. The maximum yields of recombinant bovine chymosin (CHY) and human lysozyme (HLY) produced by the AosedD disruptants showed approximately 2.9- and 1.7-fold increases, respectively, as compared to their control strains. These results suggest that AoSedD is one of the major proteases involved in the proteolytic degradation of recombinant proteins in A. oryzae.

  10. Multiple-clone activation of hypnozoites is the leading cause of relapse in Plasmodium vivax infection.

    Directory of Open Access Journals (Sweden)

    Flávia Carolina F de Araujo

    Full Text Available BACKGROUND: Plasmodium vivax infection is characterized by a dormant hepatic stage, the hypnozoite that is activated at varying periods of time after clearance of the primary acute blood-stage, resulting in relapse. Differentiation between treatment failure and new infections requires characterization of initial infections, relapses, and clone multiplicity in vivax malaria infections. METHODOLOGY/PRINCIPAL FINDINGS: Parasite DNA obtained from primary/relapse paired blood samples of 30 patients with P. vivax infection in Brazil was analyzed using 10 molecular markers (8 microsatellites and MSP-1 blocks 2 and 10. Cloning of PCR products and genotyping was used to identify low-frequency clones of parasites. We demonstrated a high frequency of multiple-clone infections in both primary and relapse infections. Few alleles were identified per locus, but the combination of these alleles produced many haplotypes. Consequently, the majority of parasites involved in relapse showed haplotypes that were distinct from those of primary infections. Plasmodium vivax relapse was characterized by temporal variations in the predominant parasite clones. CONCLUSIONS/SIGNIFICANCE: The high rate of low frequency alleles observed in both primary and relapse infections, along with temporal variation in the predominant alleles, might be the source of reported heterologous hypnozoite activation. Our findings complicate the concept of heterologous activation, suggesting the involvement of undetermined mechanisms based on host or environmental factors in the simultaneous activation of multiple clones of hypnozoites.

  11. Migrant Workers in Malaysia: Current Implications of Sociodemographic and Environmental Characteristics in the Transmission of Intestinal Parasitic Infections.

    Directory of Open Access Journals (Sweden)

    Norhidayu Sahimin

    2016-11-01

    Full Text Available A cross-sectional study of intestinal parasitic infections amongst migrant workers in Malaysia was conducted. A total of 388 workers were recruited from five sectors including manufacturing, construction, plantation, domestic and food services. The majority were recruited from Indonesia (n = 167, 43.3%, followed by Nepal (n = 81, 20.9%, Bangladesh (n = 70, 18%, India (n = 47, 12.1% and Myanmar (n = 23, 5.9.2%. A total of four nematode species (Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms, one cestode (Hymenolepis nana and three protozoan species (Entamoeba histolytica/dispar, Giardia sp. and Cryptosporidium spp. were identified. High prevalence of infections with A. lumbricoides (43.3% was recorded followed by hookworms (13.1%, E. histolytica/dispar (11.6%, Giardia sp. (10.8%, T. trichura (9.5%, Cryptosporodium spp. (3.1%, H. nana (1.8% and E. vermicularis (0.5%. Infections were significantly influenced by socio-demographic (nationality, and environmental characteristics (length of working years in the country, employment sector and educational level. Up to 84.0% of migrant workers from Nepal and 83.0% from India were infected with intestinal parasites, with the ascarid nematode A. lumbricoides occurring in 72.8% of the Nepalese and 68.1% of the Indian population. In addition, workers with an employment history of less than a year or newly arrived in Malaysia were most likely to show high levels of infection as prevalence of workers infected with A. lumbricoides was reduced from 58.2% to 35.4% following a year's residence. These findings suggest that improvement is warranted in public health and should include mandatory medical screening upon entry into the country.

  12. Migrant Workers in Malaysia: Current Implications of Sociodemographic and Environmental Characteristics in the Transmission of Intestinal Parasitic Infections

    Science.gov (United States)

    Sahimin, Norhidayu; Lim, Yvonne A. L.; Ariffin, Farnaza; Behnke, Jerzy M.; Lewis, John W.

    2016-01-01

    A cross-sectional study of intestinal parasitic infections amongst migrant workers in Malaysia was conducted. A total of 388 workers were recruited from five sectors including manufacturing, construction, plantation, domestic and food services. The majority were recruited from Indonesia (n = 167, 43.3%), followed by Nepal (n = 81, 20.9%), Bangladesh (n = 70, 18%), India (n = 47, 12.1%) and Myanmar (n = 23, 5.9.2%). A total of four nematode species (Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms), one cestode (Hymenolepis nana) and three protozoan species (Entamoeba histolytica/dispar, Giardia sp. and Cryptosporidium spp.) were identified. High prevalence of infections with A. lumbricoides (43.3%) was recorded followed by hookworms (13.1%), E. histolytica/dispar (11.6%), Giardia sp. (10.8%), T. trichura (9.5%), Cryptosporodium spp. (3.1%), H. nana (1.8%) and E. vermicularis (0.5%). Infections were significantly influenced by socio-demographic (nationality), and environmental characteristics (length of working years in the country, employment sector and educational level). Up to 84.0% of migrant workers from Nepal and 83.0% from India were infected with intestinal parasites, with the ascarid nematode A. lumbricoides occurring in 72.8% of the Nepalese and 68.1% of the Indian population. In addition, workers with an employment history of less than a year or newly arrived in Malaysia were most likely to show high levels of infection as prevalence of workers infected with A. lumbricoides was reduced from 58.2% to 35.4% following a year’s residence. These findings suggest that improvement is warranted in public health and should include mandatory medical screening upon entry into the country. PMID:27806046

  13. Effects of hygiene and defecation behavior on helminths and intestinal protozoa infections in Taabo, Côte d'Ivoire.

    Science.gov (United States)

    Schmidlin, Thomas; Hürlimann, Eveline; Silué, Kigbafori D; Yapi, Richard B; Houngbedji, Clarisse; Kouadio, Bernadette A; Acka-Douabélé, Cinthia A; Kouassi, Dongo; Ouattara, Mamadou; Zouzou, Fabien; Bonfoh, Bassirou; N'Goran, Eliézer K; Utzinger, Jürg; Raso, Giovanna

    2013-01-01

    More than 1 billion people are currently infected with soil-transmitted helminths and schistosomes. The global strategy to control helminthiases is the regular administration of anthelmintic drugs to at-risk populations. However, rapid re-infection occurs in areas where hygiene, access to clean water, and sanitation are inadequate. In July 2011, inhabitants from two villages and seven hamlets of the Taabo health demographic surveillance system in south-central Côte d'Ivoire provided stool and urine samples. Kato-Katz and ether-concentration methods were used for the diagnosis of Schistosoma mansoni, soil-transmitted helminths (Ascaris lumbricoides, Trichuris trichiura, and hookworm), and intestinal protozoa. Urine samples were subjected to a filtration method for the diagnosis of Schistosoma haematobium. A questionnaire was administered to households to obtain information on knowledge, attitude, practice, and beliefs in relation to hygiene, sanitation, and defecation behavior. Logistic regression models were employed to assess for associations between questionnaire data and parasitic infections. A total of 1,894 participants had complete data records. Parasitological examinations revealed prevalences of hookworm, S. haematobium, T. trichiura, S. mansoni, and A. lumbricoides of 33.5%, 7.0%, 1.6%, 1.3% and 0.8%, respectively. Giardia intestinalis and Entamoeba histolytica/E. dispar were detected in 15.0% and 14.4% of the participants, respectively. Only one out of five households reported the presence of a latrine, and hence, open defecation was common. Logistic regression analysis revealed that age, sex, socioeconomic status, hygiene, and defecation behavior are determinants for helminths and intestinal protozoa infections. We found that inadequate sanitation and hygiene behavior are associated with soil-transmitted helminths and intestinal protozoa infections in the Taabo area of south-central Côte d'Ivoire. Our data will serve as a benchmark to monitor the

  14. Migrant Workers in Malaysia: Current Implications of Sociodemographic and Environmental Characteristics in the Transmission of Intestinal Parasitic Infections.

    Science.gov (United States)

    Sahimin, Norhidayu; Lim, Yvonne A L; Ariffin, Farnaza; Behnke, Jerzy M; Lewis, John W; Mohd Zain, Siti Nursheena

    2016-11-01

    A cross-sectional study of intestinal parasitic infections amongst migrant workers in Malaysia was conducted. A total of 388 workers were recruited from five sectors including manufacturing, construction, plantation, domestic and food services. The majority were recruited from Indonesia (n = 167, 43.3%), followed by Nepal (n = 81, 20.9%), Bangladesh (n = 70, 18%), India (n = 47, 12.1%) and Myanmar (n = 23, 5.9.2%). A total of four nematode species (Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis and hookworms), one cestode (Hymenolepis nana) and three protozoan species (Entamoeba histolytica/dispar, Giardia sp. and Cryptosporidium spp.) were identified. High prevalence of infections with A. lumbricoides (43.3%) was recorded followed by hookworms (13.1%), E. histolytica/dispar (11.6%), Giardia sp. (10.8%), T. trichura (9.5%), Cryptosporodium spp. (3.1%), H. nana (1.8%) and E. vermicularis (0.5%). Infections were significantly influenced by socio-demographic (nationality), and environmental characteristics (length of working years in the country, employment sector and educational level). Up to 84.0% of migrant workers from Nepal and 83.0% from India were infected with intestinal parasites, with the ascarid nematode A. lumbricoides occurring in 72.8% of the Nepalese and 68.1% of the Indian population. In addition, workers with an employment history of less than a year or newly arrived in Malaysia were most likely to show high levels of infection as prevalence of workers infected with A. lumbricoides was reduced from 58.2% to 35.4% following a year's residence. These findings suggest that improvement is warranted in public health and should include mandatory medical screening upon entry into the country.

  15. Human infections and co-infections with helminths in a rural population in Guichi, Anhui Province, China

    Directory of Open Access Journals (Sweden)

    Yi Hu

    2015-11-01

    Full Text Available Helminth infections are believed to be common in tropical and subtropical countries. A cross-sectional study was carried out in two villages located in Guichi District in Anhui Province, the People’s Republic of China, where multiparasitism was investigated using parasitological tests. The data collected were fitted to Bayesian multi-level models to profile risk factors for helminth infections. The prevalence of Schistosoma (S. japonicum, Ascaris (A. lumbricoides and Trichuris (T. trichiura were 0.43% (range: 0-0.87% at the village level, 2.28% (range: 1.69-2.88%, and 0.21% (range: 0-0.42%, respectively. No hookworm infection was found. With regard to multiparasitism, only a 33-year-old female was found to be co-infected with S. japonicum and A. lumbricoides. Multiparasitism was unexpectedly rare in the study area, which contrasts with results from other studies carried out elsewhere in the country. The long-term usage of albendazole for individuals serologically positive for schistosomiasis may be the main reason, but this needs to be confirmed by future studies.

  16. Prevalence of parasitic infections in HIV-positive patients in southern Ethiopia: a cross-sectional study.

    Science.gov (United States)

    Fekadu, Sintayehu; Taye, Kefyalew; Teshome, Wondu; Asnake, Solomon

    2013-11-15

    Intestinal parasitic infections are a major public health burden in tropical countries. Although all HIV/AIDS patients are susceptible to parasitic infections, those having lower immune status are at greater risk. The aim of this study was to determine the prevalence of intestinal parasitic infections in patients living with HIV/AIDS. This was a facility-based cross-sectional study. A total of 343 consecutively sampled HIV/AIDS patients from the HIV care clinic of Hawassa University Referral Hospital were included. Subjects were interviewed for demographic variables and diarrheal symptoms using structured questionnaires. Stool examinations and CD4 cells counts were also performed. The prevalence of intestinal parasitic infection was 47.8% among HIV/AIDS patients; single helminthic infection prevalence (22.7%) was higher than that the prevalence of protozoal infections (14.6%). About 54% of study participants had chronic diarrhea while 3.4% had acute diarrhea. The prevalence of intestinal parasites in patients with chronic diarrhea was significantly higher than in acute diarrhea (p intestinal parasite infections such as Ascaris lumbricoides, Taenia spp., and hookworm were commonly found, regardless of immune status or diarrheal symptoms. Opportunistic and non-opportunistic intestinal parasitic infection were more frequent in patients with a CD4 count of Intestinal parasitic infections should be suspected in HIV/AIDS-infected patients with advanced disease presenting with chronic diarrhea. Patients with low CD4 counts should be examined critically for intestinal parasites, regardless of diarrheal status.

  17. Poly-helminth infection in east guatemalan school children

    Directory of Open Access Journals (Sweden)

    William C Sorensen

    2011-01-01

    Full Text Available Background: Soil transmitted helminths (STH remain a global public health concern in spite of occasional dosing campaigns. Aims: To determine baseline prevalence and intensity of STH infection in east Guatemalan school children, and describe the associated epidemiology of anemia, stunting, and wasting in this population. Setting and design: Ten schools in Izabal province (eastern Guatemala were identified, and 1,001 school children were selected for this study. Half of the schools were used as clinical testing sites (blood and stool. Materials and Methods: Anthropometric measures were collected from all children. Over 300 children were tested for anemia and 229 for helminth infection. Ova and parasite specimens were examined via Direct, Kato Katz, and McMaster techniques. Hemoglobin was measured from venipuncture following the hemacue system. Statistical analysis: Correlation between infection intensities and growth indicators were examined. Chi Square or t tests were used for bivariate analysis. Multiple logistic regression was performed on significant variables from bivariate techniques. Results: Over two-thirds of school children were positive for infection by any STH. Prevalence of Hookworm was 30%; Ascaris, 52%; and Trichuris, 39%, most as low-intensity infection. Over half of the children were co-infected. In bivariate analysis, anemia was significantly associated with polyparasitism. Conclusions: For a Guatemalan child who experiences a unit decrease in hemoglobin, one expects to see a 24% increase in the odds of being infected with STH, controlling for age, sex, lake proximity, and growth characteristics. Infection with more than one STH, despite low intensity, led to a significant decrease in hemoglobin.

  18. Rainbow trout surviving infections of viral haemorrhagic septicemia virus (VHSV) show lasting antibodies to recombinant G protein fragments

    DEFF Research Database (Denmark)

    Encinas, P.; Gomez-Casado, E.; Grandes, Fregeneda

    2011-01-01

    sera from trout infected with the homologous VHSV isolate but also with the VHSV-DK-201433 heterologous isolate, which had 13 amino acid changes. Sera from healthy trout and/or from trout surviving infectious haematopoietic necrosis virus (IHNV) infection, were used to calculate cut-off absorbances...... refinements of the frg-ELISA could allow detection of anti-VHSV trout Abs in natural outbreaks caused by different heterologous VHSV isolates. The homologous frg-ELISA method could be useful to follow G immunization attempts during vaccine development and/or to best understand the fish Ab response during VHSV...... infections. The viral frgs approach might also be used with other fish species and/or viruses....

  19. Yeast as a Heterologous Model System to Uncover Type III Effector Function.

    Directory of Open Access Journals (Sweden)

    Crina Popa

    2016-02-01

    Full Text Available Type III effectors (T3E are key virulence proteins that are injected by bacterial pathogens inside the cells of their host to subvert cellular processes and contribute to disease. The budding yeast Saccharomyces cerevisiae represents an important heterologous system for the functional characterisation of T3E proteins in a eukaryotic environment. Importantly, yeast contains eukaryotic processes with low redundancy and are devoid of immunity mechanisms that counteract T3Es and mask their function. Expression in yeast of effectors from both plant and animal pathogens that perturb conserved cellular processes often resulted in robust phenotypes that were exploited to elucidate effector functions, biochemical properties, and host targets. The genetic tractability of yeast and its amenability for high-throughput functional studies contributed to the success of this system that, in recent years, has been used to study over 100 effectors. Here, we provide a critical view on this body of work and describe advantages and limitations inherent to the use of yeast in T3E research. "Favourite" targets of T3Es in yeast are cytoskeleton components and small GTPases of the Rho family. We describe how mitogen-activated protein kinase (MAPK signalling, vesicle trafficking, membrane structures, and programmed cell death are also often altered by T3Es in yeast and how this reflects their function in the natural host. We describe how effector structure-function studies and analysis of candidate targeted processes or pathways can be carried out in yeast. We critically analyse technologies that have been used in yeast to assign biochemical functions to T3Es, including transcriptomics and proteomics, as well as suppressor, gain-of-function, or synthetic lethality screens. We also describe how yeast can be used to select for molecules that block T3E function in search of new antibacterial drugs with medical applications. Finally, we provide our opinion on the limitations

  20. Phaseolin expression in tobacco chloroplast reveals an autoregulatory mechanism in heterologous protein translation.

    Science.gov (United States)

    De Marchis, Francesca; Bellucci, Michele; Pompa, Andrea

    2016-02-01

    Plastid DNA engineering is a well-established research area of plant biotechnology, and plastid transgenes often give high expression levels. However, it is still almost impossible to predict the accumulation rate of heterologous protein in transplastomic plants, and there are many cases of unsuccessful transgene expression. Chloroplasts regulate their proteome at the post-transcriptional level, mainly through translation control. One of the mechanisms to modulate the translation has been described in plant chloroplasts for the chloroplast-encoded subunits of multiprotein complexes, and the autoregulation of the translation initiation of these subunits depends on the availability of their assembly partners [control by epistasy of synthesis (CES)]. In Chlamydomonas reinhardtii, autoregulation of endogenous proteins recruited in the assembly of functional complexes has also been reported. In this study, we revealed a self-regulation mechanism triggered by the accumulation of a soluble recombinant protein, phaseolin, in the stroma of chloroplast-transformed tobacco plants. Immunoblotting experiments showed that phaseolin could avoid this self-regulation mechanism when targeted to the thylakoids in transplastomic plants. To inhibit the thylakoid-targeted phaseolin translation as well, this protein was expressed in the presence of a nuclear version of the phaseolin gene with a transit peptide. Pulse-chase and polysome analysis revealed that phaseolin mRNA translation on plastid ribosomes was repressed due to the accumulation in the stroma of the same soluble polypeptide imported from the cytosol. We suggest that translation autoregulation in chloroplast is not limited to heteromeric protein subunits but also involves at least some of the foreign soluble recombinant proteins, leading to the inhibition of plastome-encoded transgene expression in chloroplast. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Heterologous Expression and Biochemical Characterization of Two Lipoxygenases in Oriental Melon, Cucumis melo var. makuwa Makino.

    Directory of Open Access Journals (Sweden)

    Songxiao Cao

    Full Text Available Lipoxygenases (LOXs are a class of non-heme iron-containing dioxygenases that catalyse oxidation of polyunsaturated fatty acids to produce hydroperoxidation that are in turn converted to oxylipins. Although multiple isoforms of LOXs have been detected in several plants, LOXs in oriental melon have not attracted much attention. Two full-length LOX cDNA clones, CmLOX10 and CmLOX13 which have been isolated from oriental melon (Cucumis melo var. makuwa Makino cultivar "Yumeiren", encode 902 and 906 amino acids, respectively. Bioinformatics analysis showed that CmLOX10 and CmLOX13 included all of the typical LOX domains and shared 58.11% identity at the amino acid level with each other. The phylogenetic analysis revealed that CmLOX10 and CmLOX13 were members of the type 2 13-LOX subgroup which are known to be involved in biotic and abiotic stress. Heterologous expression of the full-length CmLOX10 and truncated CmLOX13 in Escherichia coli revealed that the encoded exogenous proteins were identical to the predicted molecular weights and possessed the lipoxygenase activities. The purified CmLOX10 and CmLOX13 recombinant enzymes exhibited maximum activity at different temperature and pH and both had higher affinity for linoleic acid than linolenic acid. Chromatogram analysis of reaction products from the CmLOX10 and CmLOX13 enzyme reaction revealed that both enzymes produced 13S-hydroperoxides when linoleic acid was used as substrate. Furthermore, the subcellular localization analysis by transient expression of the two LOX fusion proteins in tobacco leaves showed that CmLOX10 and CmLOX13 proteins were located in plasma membrane and chloroplasts respectively. We propose that the two lipoxygenases may play different functions in oriental melon during plant growth and development.

  2. Heterologous expression of the antimyotoxic protein DM64 in Pichia pastoris.

    Directory of Open Access Journals (Sweden)

    Saulo Martins Vieira

    2017-07-01

    Full Text Available Snakebite envenomation is a neglected condition that constitutes a public health problem in tropical and subtropical countries, including Brazil. Interestingly, some animals are resistant to snake envenomation due to the presence of inhibitory glycoproteins in their serum that target toxic venom components. DM64 is an acidic glycoprotein isolated from Didelphis aurita (opossum serum that has been characterized as an inhibitor of the myotoxicity induced by bothropic toxins bearing phospholipase A2 (PLA2 structures. This antitoxic protein can serve as an excellent starting template for the design of novel therapeutics against snakebite envenomation, particularly venom-induced local tissue damage. Therefore, the aim of this work was to produce a recombinant DM64 (rDM64 in the methylotrophic yeast Pichia pastoris and to compare its biological properties with those of native DM64. Yeast fermentation in the presence of Pefabloc, a serine protease inhibitor, stimulated cell growth (~1.5-fold, increased the rDM64 production yield approximately 10-fold and significantly reduced the susceptibility of rDM64 to proteolytic degradation. P. pastoris fermentation products were identified by mass spectrometry and Western blotting. The heterologous protein was efficiently purified from the culture medium by affinity chromatography (with immobilized PLA2 myotoxin and/or an ion exchange column. Although both native and recombinant DM64 exhibit different glycosylation patterns, they show very similar electrophoretic mobilities after PNGase F treatment. rDM64 formed a noncovalent complex with myotoxin II (Lys49-PLA2 from Bothrops asper and displayed biological activity that was similar to that of native DM64, inhibiting the cytotoxicity of myotoxin II by 92% at a 1:1 molar ratio.

  3. Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae.

    Science.gov (United States)

    Milne, N; Luttik, M A H; Cueto Rojas, H F; Wahl, A; van Maris, A J A; Pronk, J T; Daran, J M

    2015-07-01

    In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing chemicals, uptake and assimilation of ammonium requires 1 ATP per incorporated NH3. Urea assimilation by this yeast is more energy efficient but still requires 0.5 ATP per NH3 produced. To decrease ATP costs for nitrogen assimilation, the S. cerevisiae gene encoding ATP-dependent urease (DUR1,2) was replaced by a Schizosaccharomyces pombe gene encoding ATP-independent urease (ure2), along with its accessory genes ureD, ureF and ureG. Since S. pombe ure2 is a Ni(2+)-dependent enzyme and Saccharomyces cerevisiae does not express native Ni(2+)-dependent enzymes, the S. pombe high-affinity nickel-transporter gene (nic1) was also expressed. Expression of the S. pombe genes into dur1,2Δ S. cerevisiae yielded an in vitro ATP-independent urease activity of 0.44±0.01 µmol min(-1) mg protein(-1) and restored growth on urea as sole nitrogen source. Functional expression of the Nic1 transporter was essential for growth on urea at low Ni(2+) concentrations. The maximum specific growth rates of the engineered strain on urea and ammonium were lower than those of a DUR1,2 reference strain. In glucose-limited chemostat cultures with urea as nitrogen source, the engineered strain exhibited an increased release of ammonia and reduced nitrogen content of the biomass. Our results indicate a new strategy for improving yeast-based production of nitrogen-containing chemicals and demonstrate that Ni(2+)-dependent enzymes can be functionally expressed in S. cerevisiae. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  4. Heterologous expression and characterization of Bacillus coagulans L-arabinose isomerase.

    Science.gov (United States)

    Zhou, Xingding; Wu, Jin Chuan

    2012-05-01

    Bacillus coagulans has been of great commercial interest over the past decade owing to its strong ability of producing optical pure L: -lactic acid from both hexose and pentose sugars including L: -arabinose with high yield, titer and productivity under thermophilic conditions. The L: -arabinose isomerase (L-AI) from Bacillus coagulans was heterologously over-expressed in Escherichia coli. The open reading frame of the L-AI has 1,422 nucleotides encoding a protein with 474 amino acid residues. The recombinant L-AI was purified to homogeneity by one-step His-tag affinity chromatography. The molecular mass of the enzyme was estimated to be 56 kDa by SDS-PAGE. The enzyme was most active at 70°C and pH 7.0. The metal ion Mn(2+) was shown to be the best activator for enzymatic activity and thermostability. The enzyme showed higher activity at acidic pH than at alkaline pH. The kinetic studies showed that the K (m), V (max) and k (cat)/K (m) for the conversion of L: -arabinose were 106 mM, 84 U/mg and 34.5 mM(-1)min(-1), respectively. The equilibrium ratio of L: -arabinose to L: -ribulose was 78:22 under optimal conditions. L: -ribulose (97 g/L) was obtained from 500 g/l of L: -arabinose catalyzed by the enzyme (8.3 U/mL) under the optimal conditions within 1.5 h, giving at a substrate conversion of 19.4% and a production rate of 65 g L(-1) h(-1).

  5. Heterologous expression of the Crassostrea gigas (Pacific oyster) alternative oxidase in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Robertson, Aaron; Schaltz, Kyle; Neimanis, Karina; Staples, James F; McDonald, Allison E

    2016-10-01

    Alternative oxidase (AOX) is a terminal oxidase within the inner mitochondrial membrane (IMM) present in many organisms where it functions in the electron transport system (ETS). AOX directly accepts electrons from ubiquinol and is therefore capable of bypassing ETS Complexes III and IV. The human genome does not contain a gene coding for AOX, so AOX expression has been suggested as a gene therapy for a range of human mitochondrial diseases caused by genetic mutations that render Complex III and/or IV dysfunctional. An effective means of screening mutations amenable to AOX treatment remains to be devised. We have generated such a tool by heterologously expressing AOX from the Pacific oyster (Crassostrea gigas) in the yeast Saccharomyces cerevisiae under the control of a galactose promoter. Our results show that this animal AOX is monomeric and is correctly targeted to yeast mitochondria. Moreover, when expressed in yeast, Pacific oyster AOX is a functional quinol oxidase, conferring cyanide-resistant growth and myxothiazol-resistant oxygen consumption to yeast cells and isolated mitochondria. This system represents a high-throughput screening tool for determining which Complex III and IV genetic mutations in yeast will be amenable to AOX gene therapy. As many human genes are orthologous to those found in yeast, our invention represents an efficient and cost-effective way to evaluate viable research avenues. In addition, this system provides the opportunity to learn more about the localization, structure, and regulation of AOXs from animals that are not easily reared or manipulated in the lab.

  6. Altered Phenotypes in Saccharomyces cerevisiae by Heterologous Expression of Basidiomycete Moniliophthora perniciosa SOD2 Gene

    Directory of Open Access Journals (Sweden)

    Sônia C. Melo

    2015-06-01

    Full Text Available Heterologous expression of a putative manganese superoxide dismutase gene (SOD2 of the basidiomycete Moniliophthora perniciosa complemented the phenotypes of a Saccharomyces cerevisiae sod2Δ mutant. Sequence analysis of the cloned M. perniciosa cDNA revealed an open reading frame (ORF coding for a 176 amino acid polypeptide with the typical metal-binding motifs of a SOD2 gene, named MpSOD2. Phylogenetic comparison with known manganese superoxide dismutases (MnSODs located the protein of M. perniciosa (MpSod2p in a clade with the basidiomycete fungi Coprinopsis cinerea and Laccaria bicolor. Haploid wild-type yeast transformants containing a single copy of MpSOD2 showed increased resistance phenotypes against oxidative stress-inducing hydrogen peroxide and paraquat, but had unaltered phenotype against ultraviolet–C (UVC radiation. The same transformants exhibited high sensitivity against treatment with the pro-mutagen diethylnitrosamine (DEN that requires oxidation to become an active mutagen/carcinogen. Absence of MpSOD2 in the yeast sod2Δ mutant led to DEN hyper-resistance while introduction of a single copy of this gene restored the yeast wild-type phenotype. The haploid yeast wild-type transformant containing two SOD2 gene copies, one from M. perniciosa and one from its own, exhibited DEN super-sensitivity. This transformant also showed enhanced growth at 37 °C on the non-fermentable carbon source lactate, indicating functional expression of MpSod2p. The pro-mutagen dihydroethidium (DHE-based fluorescence assay monitored basal level of yeast cell oxidative stress. Compared to the wild type, the yeast sod2Δ mutant had a much higher level of intrinsic oxidative stress, which was reduced to wild type (WT level by introduction of one copy of the MpSOD2 gene. Taken together our data indicates functional expression of MpSod2 protein in the yeast S. cerevisiae.

  7. Heterologous Protein Expression in Pichia pastoris: Latest Research Progress and Applications.

    Science.gov (United States)

    Juturu, Veeresh; Wu, Jin Chuan

    2018-01-04

    Pichia pastoris is a well-known platform strain for heterologous protein expression. Over the past five years, different strategies to improve the efficiency of recombinant protein expression by this yeast strain have been developed; these include a patent-free protein expression kit, construction of the P. pastoris CBS7435Ku70 platform strain with its high efficiency in site-specific recombination of plasmid DNA into the genomic DNA, the design of synthetic promoters and their variants by combining different core promoters with multiple putative transcription factors, the generation of mutant GAP promoter variants with various promoter strengths, codon optimization, engineering the α-factor signal sequence by replacing the native glutamic acid at the Kex2 cleavage site with the other 19 natural amino acids and the addition of mammalian signal sequence to the yeast signal sequence, and the co-expression of single chaperones, multiple chaperones or helper proteins that aid in recombinant protein folding. Publically available high-quality genome data from multiple strains of P. pastoris GS115, DSMZ 70382, and CBS7435 and the continuous development of yeast expression kits have successfully promoted the metabolic engineering of this strain to produce carotenoids, xanthophylls, nootkatone, ricinoleic acid, dammarenediol-II, and hyaluronic acid. The cell-surface display of enzymes has obviously increased enzyme stability, and high-level intracellular expression of acyl-CoA and ethanol O-acyltransferase, lipase and d-amino acid oxidase has opened up applications in whole-cell biocatalysis for producing flavor molecules and biodiesel, as well as the deracemization of racemic amino acids. High-level expression of various food-grade enzymes, cellulases, and hemicellulases for applications in the food, feed and biorefinery industries is in its infancy and needs strengthening. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Heterologous, Fresh, Human Donor Sclera as Patch Graft Material in Glaucoma Drainage Device Surgery.

    Science.gov (United States)

    Tsoukanas, Dimitrios; Xanthopoulou, Paraskevi; Charonis, Alexandros C; Theodossiadis, Panagiotis; Kopsinis, Gerasimos; Filippopoulos, Theodoros

    2016-07-01

    To determine the safety and efficacy of fresh, human sclera allografts as a patch graft material in glaucoma drainage device (GDD) surgery. Retrospective, noncomparative, interventional, consecutive case series. All GDD cases operated between 2008 and 2013 in which fresh human corneoscleral rims were used immediately after the central corneal button was used for penetrating or endothelial keratoplasty. Surgery was performed by 2 surgeons at 2 facilities. The Ahmed Glaucoma Valve (FP-7) was used exclusively in this cohort. Sixty-four eyes of 60 patients were identified; demographic data were recorded along with intraocular pressure (IOP), medication requirements, visual acuity, complications, and subsequent interventions. Incidence of complications. IOP and medication requirements at the last follow-up. Quilified success utilizing Tube Versus Trabeculectomy study criteria. The mean age of the cohort was 66.2±19.1 years; the average preoperative IOP was 33.2±11.1 mm Hg on 4.2±1.3 IOP-lowering agents before GDD surgery. IOP decreased significantly to 14.1±4.7 mm Hg (Pendophthalmitis, and there was 1 case of conjunctival erosion and tube/plate exposure (1.6%) occurring 30 days after surgery. Qualified success was estimated as 90.5% and 81% at 1 and 2 years, respectively, using Tube Versus Trabeculectomy study criteria. Heterologous, fresh, human donor sclera appears to be a safe material for GDD tube coverage. It provides a cost-efficient alternative compared with traditional patch graft materials associated with a low risk of pathogen transmission.

  9. Changing trends in intestinal parasitic infections among long-term-residents and settled immigrants in Qatar

    Directory of Open Access Journals (Sweden)

    Doiphode Sanjay H

    2010-10-01

    Full Text Available Abstract Background The rapid socio-economic development in Qatar in the last two decades has encouraged a mass influx of immigrant workers, the majority of whom originate from countries with low socio-economic levels, inadequate medical care and many are known to carry patent intestinal helminth and protozoan infections on arrival in Qatar. Some eventually acquire residency status but little is known about whether they continue to harbour infections. Methods We examined 9208 hospital records of stool samples that had been analysed for the presence of intestinal helminth and protozoan ova/cysts, over the period 2005-2008, of subjects from 28 nationalities, but resident in Qatar and therefore not recent arrivals in the country. Results Overall 10.2% of subjects were infected with at least one species, 2.6% with helminths and 8.0% with protozoan species. Although hookworms, Ascaris lumbricoides, Trichuris trichiura and Hymenolepis nana were observed, the majority of helminth infections (69% were caused by hookworms, and these were largely aggregated among 20.0-39.9 year-old male subjects from Nepal. The remaining cases of helminth infection were mostly among Asian immigrants. Protozoan infections were more uniformly spread across immigrants from different regions when prevalence was calculated on combined data, but this disguised three quite contrasting underlying patterns for 3 taxa of intestinal protozoa. Blastocystis hominis, Giardia duodenalis and non-pathogenic amoebae were all acquired in childhood, but whereas prevalence of B. hominis rose to a plateau and then even further among the elderly, prevalence of G. duodenalis fell markedly in children aged 10 and older, and stayed low (Entamoeba coli, E. hartmanni, Endolimax nana and Iodamoeba buetschlii peaked in the 30.0-39.9 age group and only then dropped to very low values among the oldest subjects examined. A worrying trend in respect of both helminth and protozoan parasites was the

  10. B cells are not essential for Lactobacillus-mediated protection against lethal pneumovirus infection*

    OpenAIRE

    Percopo, Caroline M.; Dyer, Kimberly D.; Garcia-Crespo, Katia E.; Gabryszewski, Stanislaw J.; Shaffer, Arthur L.; Domachowske, Joseph B.; Rosenberg, Helene F.

    2014-01-01

    We have shown previously that priming of respiratory mucosa with live Lactobacillus species promotes robust and prolonged survival from an otherwise lethal infection with pneumonia virus of mice (PVM), a property known as heterologous immunity. Lactobacillus-priming results in a moderate reduction in virus recovery and a dramatic reduction in virus-induced proinflammatory cytokine production; the precise mechanisms underlying these findings remain to be elucidated. As B cells have been shown ...

  11. Prevalence of gastrointestinal helminthic infections and associated risk factors among schoolchildren in Tilili town, northwest Ethiopia.

    Science.gov (United States)

    Abera, Alamneh; Nibret, Endalkachew

    2014-07-01

    To determine the prevalence of gastrointestinal helminthes and associated risk factors among schoolchildren in Tilili town, northwest Ethiopia. A cross-sectional study involving 385 schoolchildren was conducted between November 2011 to February 2012. Each student was selected using systematic random sampling method. Questionnaire and observation were used to identify socio-demographic and associated risk factors. Fresh stool samples were observed using formal-ether concentration technique. Data were analyzed using SPSS 16.0 statistical software. Four species of intestinal helminthes were identified with an overall prevalence of 44.2% (170 of 385 schoolchildren). The predominant parasites were Ascaris lumbricoides (A. lumbricoides) 153 (39.7%) and Trichuris trichiura (T. trichiura) 30 (7.8%). One hundred thirty five (35.1%) had single infections and 35 (9.2%) were infected with more than one helminthic parasites in which 32 (8.4%) were double infections and 3 (0.8%) were triple infections. Significant associations were observed between intestinal helminth infection and those of age, grade level, and school variables. Prevalence of hookworm infection was significant in children who did not wear shoes regularly (P<0.05). Intervention programs and education on personal and environmental hygiene should be implemented for the prevention and control of helminthic infections in the study area. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  12. The Impact of Intestinal Parasitic Infections on the Nutritional Status of Rural and Urban School-Aged Children in Nigeria

    Directory of Open Access Journals (Sweden)

    Kenneth N. Opara, PhD

    2012-11-01

    Full Text Available Objectives:Intestinal parasitic infection and undernutrition are still major public health problems in poor and developing countries. The objective of this study was to assess the relationship between intestinal parasitic infection and nutritional status in 405 primary school children from rural and urban areas of Akwa Ibom State, Nigeria.Methods:This cross-sectional survey in 2009 obtained anthropometric data, height-for-age (HA, weight-for-height (WH and weight-for-age (WA Z-scores from each child and fecal samples were also collected and screened for intestinal parasites using standard parasitological protocols.Results:The prevalence of infection with any intestinal parasite was 67.4%. A total of six intestinal parasites were detected; hookworm (41.7% had the highest prevalence. The prevalence of intestinal parasites and undernutrition was significantly higher in rural than in urban children (P<0.001. The prevalence of stunting (HAZ < -2, underweight (WAZ < -2 and wasting (WHZ < -2 for rural and urban children were 42.3% vs. 29.7%; underweight 43.2% vs. 29.6% and wasting 10.9% vs. 6.4%, respectively. With respect to nutritional indicators, the infected children had significantly (P<0.05 higher z-scores than the uninfected children. Multivariate logistic regression analysis showed that only Hookworm and Ascaris lumbricoides were each significantly (P<0.05 associated with stunting, wasting, and underweight.Conclusions and Public Health Implications:Since intestinal parasitic infections are associated with malnutrition, controlling these parasites could increase the physical development and well-being of the affected children.

  13. Soil transmitted helminths and schistosoma mansoni infections among school children in zarima town, northwest Ethiopia

    Directory of Open Access Journals (Sweden)

    Birhan Wubet

    2011-07-01

    Full Text Available Abstract Background In Ethiopia, because of low quality drinking water supply and latrine coverage, helminths infections are the second most predominant causes of outpatient morbidity. Indeed, there is a scarcity of information on the prevalence of soil transmitted helminths and Schistosomiasis in Ethiopia, special in study area. Therefore, the aim of this study was to determine the prevalence and associated risk factors of soil transmitted helminths and intestinal Schistosomiasis. Methods Cross-sectional study was conducted among 319 school children of Zarima town from April 1 to May 25, 2009. A pre-tested structured questionnaire was used to collect socio-demographic data and possible risk factors exposure. Early morning stool samples were collected and a Kato Katz semi concentration technique was used to examine and count parasitic load by compound light microscope. Data entry and analysis was done using SPSS-15 version and p-value Results Out of 319 study subjects, 263 (82.4% of the study participants infected with one or more parasites. From soil transmitted helminths, Ascaris lumbricoides was the predominant isolate (22% followed by Hookworms (19% and Trichuris trichiura (2.5%. Schistosoma mansoni was also isolated in 37.9% of the study participants. Hookworm and S. mansoni infections showed statistically significant associations with shoe wearing and swimming habit of school children, respectively. Conclusion Prevalence of soil transmitted helminths (STH and S.mansoni was high and the diseases were still major health problem in the study area which alerts public health intervention as soon as possible.

  14. Heterologous prime-boost immunization of Newcastle disease virus vectored vaccines protected broiler chickens against highly pathogenic avian influenza and Newcastle disease viruses.

    Science.gov (United States)

    Kim, Shin-Hee; Samal, Siba K

    2017-07-24

    Avian Influenza virus (AIV) is an important pathogen for both human and animal health. There is a great need to develop a safe and effective vaccine for AI infections in the field. Live-attenuated Newcastle disease virus (NDV) vectored AI vaccines have shown to be effective, but preexisting antibodies to the vaccine vector can affect the protective efficacy of the vaccine in the field. To improve the efficacy of AI vaccine, we generated a novel vectored vaccine by using a chimeric NDV vector that is serologically distant from NDV. In this study, the protective efficacy of our vaccines was evaluated by using H5N1 highly pathogenic avian influenza virus (HPAIV) strain A/Vietnam/1203/2004, a prototype strain for vaccine development. The vaccine viruses were three chimeric NDVs expressing the hemagglutinin (HA) protein in combination with the neuraminidase (NA) protein, matrix 1 protein, or nonstructural 1 protein. Comparison of their protective efficacy between a single and prime-boost immunizations indicated that prime immunization of 1-day-old SPF chicks with our vaccine viruses followed by boosting with the conventional NDV vector strain LaSota expressing the HA protein provided complete protection of chickens against mortality, clinical signs and virus shedding. Further verification of our heterologous prime-boost immunization using commercial broiler chickens suggested that a sequential immunization of chickens with chimeric NDV vector expressing the HA and NA proteins following the boost with NDV vector expressing the HA protein can be a promising strategy for the field vaccination against HPAIVs and against highly virulent NDVs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Gastrointestinal and urinary tract pathogenic infections among HIV seropositive patients at the Komfo Anokye Teaching Hospital in Ghana.

    Science.gov (United States)

    Boaitey, Yaw Agyekum; Nkrumah, Bernard; Idriss, Ali; Tay, Samuel Crowther Kofi

    2012-08-21

    Gastrointestinal and urinary tract pathogenic infections are aggravating the incidence and progression of the Human Immunodeficiency Virus (HIV) infection into Acquired Immune Deficiency Syndrome (AIDS) more especially in the developing countries. This study was conducted to assess the common gastrointestinal and urinary infections among HIV/AIDS patients at the Komfo Anokye Teaching Hospital (KATH) in Ghana between April and December 2008. This work reports on gastrointestinal and urinary tract pathogenic infections among 500 HIV seropositive and 300 HIV seronegative patients. There was a 35% (175/500) prevalence of intestinal parasites among HIV seropositive patients compared to 4.3% (13/300) in HIV seronegative patients. Giardia lamblia and Cryptosporidium accounted for 19% (95/500) and 14% (70/500) respectively, while Schistosoma mansoni, Strongyloides stercoralis and hookworm together accounted for 2% (10/500) of intestinal parasitic infections among the HIV seropositive patients. There was no significant difference (p > 0.05) in urinary parasitic infection between HIV seropositive 1% (2/500) and seronegative patients 0.7% (2/300). Most, 60 (86%) out of 70, of the urinary tract infection among the HIV seropositive patients was due to bacteria with E. coli being the most predominant isolate, 28 (47%) out of 60. There was no significant difference in infections based on age and gender. G. lamblia and Cryptosporidium were the most common gastrointestinal parasites detected while bacteria accounted for majority of the urinary tract infections among the HIV seropositive patients at the hospital.

  16. Murine Leukemia Virus (MLV)-based Coronavirus Spike-pseudotyped Particle Production and Infection

    Science.gov (United States)

    Millet, Jean Kaoru; Whittaker, Gary R.

    2016-01-01

    Viral pseudotyped particles (pp) are enveloped virus particles, typically derived from retroviruses or rhabdoviruses, that harbor heterologous envelope glycoproteins on their surface and a genome lacking essential genes. These synthetic viral particles are safer surrogates of native viruses and acquire the tropism and host entry pathway characteristics governed by the heterologous envelope glycoprotein used. They have proven to be very useful tools used in research with many applications, such as enabling the study of entry pathways of enveloped viruses and to generate effective gene-delivery vectors. The basis for their generation lies in the capacity of some viruses, such as murine leukemia virus (MLV), to incorporate envelope glycoproteins of other viruses into a pseudotyped virus particle. These can be engineered to contain reporter genes such as luciferase, enabling quantification of virus entry events upon pseudotyped particle infection with susceptible cells. Here, we detail a protocol enabling generation of MLV-based pseudotyped particles, using the Middle East respiratory syndrome coronavirus (MERS-CoV) spike (S) as an example of a heterologous envelope glycoprotein to be incorporated. We also describe how these particles are used to infect susceptible cells and to perform a quantitative infectivity readout by a luciferase assay. PMID:28018942

  17. Pinworm Infection

    Science.gov (United States)

    Pinworm infection Overview Pinworm infection is the most common type of intestinal worm infection in the United States and one of the most common worldwide. Pinworms are thin and white, measuring about 1/4 ...

  18. Studies on Ancylostomiasis: II.Clinical Symptomatology, Effects of Drugs, especially of Iron Compounds, with Relation to the Severity of Artificial Infection

    International Nuclear Information System (INIS)

    Lee, Mun Ho; Kim, Dong Jip; Lee, Jang Kyu; Seo, Byong Sul

    1967-01-01

    This study was aimed; firstly to observe various clinical symptomatology with relation to the number of Ancylostoma duodenale larvae orally given to the human beings, secondly to evaluate the effects of some drugs like steroid hormones, antihistaminics and antitussives, and, thirdly to study the influences of some iron compounds in prevention and treatment of anemia of such origin. Ten healthy volunteers free from the previous history of hookworm infection were divided into 4 groups, to whom various numbers of actively moving filariform Ancylostoma duodenale larvae were orally given; 500 to 4 cases, 250 to 3 cases and 100 to 3 cases. Following were the results: 1. Clinical symptomatology. 1) The most frequently encountered symptoms and signs were general malaise, cough and hoarseness. The tracheal itching and pain, low back pain, arthralgia, sputum and salivation, acid belching, loss of appetite, abdominal pain and vomiting were also noted. 2) If the larger number of the larvae was given, the clinical symptomatology was more severe. 3) Prednisolone medication caused some improvement of such symptomatology, while the antihistaminics and antitussives like codeine or ephedrine were ineffective. 4) In volunteers whose nutritional conditions were rather poor appeared to show more severe symptomatology. 2. Effects of iron compounds. 1) The oral administration of ferrous fumarate induced a slight increase of serum iron levels in the initial stage of the infection, then a decrease from 15-20 days later and a recovery after 2 months. 2) The intravenous administration of saccharated ferric oxide induced a steady upkeep of the serum iron levels. 3) The hemoglobin contents also showed the upkeeps after either the oral or intravenous administration of the iron compounds. 4) The iron compounds, therefore, are considered to have the preventive as well as the therapeutic effects on hookworm anemia, which may strongly suggest that hookworm anemia is essentially the iron deficiency

  19. Studies on Ancylostomiasis: II.Clinical Symptomatology, Effects of Drugs, especially of Iron Compounds, with Relation to the Severity of Artificial Infection

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mun Ho; Kim, Dong Jip; Lee, Jang Kyu; Seo, Byong Sul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1967-09-15

    This study was aimed; firstly to observe various clinical symptomatology with relation to the number of Ancylostoma duodenale larvae orally given to the human beings, secondly to evaluate the effects of some drugs like steroid hormones, antihistaminics and antitussives, and, thirdly to study the influences of some iron compounds in prevention and treatment of anemia of such origin. Ten healthy volunteers free from the previous history of hookworm infection were divided into 4 groups, to whom various numbers of actively moving filariform Ancylostoma duodenale larvae were orally given; 500 to 4 cases, 250 to 3 cases and 100 to 3 cases. Following were the results: 1. Clinical symptomatology. 1) The most frequently encountered symptoms and signs were general malaise, cough and hoarseness. The tracheal itching and pain, low back pain, arthralgia, sputum and salivation, acid belching, loss of appetite, abdominal pain and vomiting were also noted. 2) If the larger number of the larvae was given, the clinical symptomatology was more severe. 3) Prednisolone medication caused some improvement of such symptomatology, while the antihistaminics and antitussives like codeine or ephedrine were ineffective. 4) In volunteers whose nutritional conditions were rather poor appeared to show more severe symptomatology. 2. Effects of iron compounds. 1) The oral administration of ferrous fumarate induced a slight increase of serum iron levels in the initial stage of the infection, then a decrease from 15-20 days later and a recovery after 2 months. 2) The intravenous administration of saccharated ferric oxide induced a steady upkeep of the serum iron levels. 3) The hemoglobin contents also showed the upkeeps after either the oral or intravenous administration of the iron compounds. 4) The iron compounds, therefore, are considered to have the preventive as well as the therapeutic effects on hookworm anemia, which may strongly suggest that hookworm anemia is essentially the iron deficiency

  20. Heterologous Expression of the Cotton NBS-LRR Gene GbaNA1 Enhances Verticillium Wilt Resistance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Nan-Yang Li

    2018-02-01

    Full Text Available Verticillium wilt caused by Verticillium dahliae results in severe losses in cotton, and is economically the most destructive disease of this crop. Improving genetic resistance is the cleanest and least expensive option to manage Verticillium wilt. Previously, we identified the island cotton NBS-LRR-encoding gene GbaNA1 that confers resistance to the highly virulent V. dahliae isolate Vd991. In this study, we expressed cotton GbaNA1 in the heterologous system of Arabidopsis thaliana and investigated the defense response mediated by GbaNA1 following inoculations with V. dahliae. Heterologous expression of GbaNA1 conferred Verticillium wilt resistance in A. thaliana. Moreover, overexpression of GbaNA1 enabled recovery of the resistance phenotype of A. thaliana mutants that had lost the function of GbaNA1 ortholog gene. Investigations of the defense response in A. thaliana showed that the reactive oxygen species (ROS production and the expression of genes associated with the ethylene signaling pathway were enhanced significantly following overexpression of GbaNA1. Intriguingly, overexpression of the GbaNA1 ortholog from Gossypium hirsutum (GhNA1 in A. thaliana did not induce the defense response of ROS production due to the premature termination of GhNA1, which lacks the encoded NB-ARC and LRR motifs. GbaNA1 therefore confers Verticillium wilt resistance in A. thaliana by the activation of ROS production and ethylene signaling. These results demonstrate the functional conservation of the NBS-LRR-encoding GbaNA1 in a heterologous system, and the mechanism of this resistance, both of which may prove valuable in incorporating GbaNA1-mediated resistance into other plant species.

  1. Shewanella oneidensis: a new and efficient System for Expression and Maturation of heterologous [Fe-Fe] Hydrogenase from Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Sybirna Kateryna

    2008-09-01

    Full Text Available Abstract Background The eukaryotic green alga, Chlamydomonas reinhardtii, produces H2 under anaerobic conditions, in a reaction catalysed by a [Fe-Fe] hydrogenase HydA1. For further biochemical and biophysical studies a suitable expression system of this enzyme should be found to overcome its weak expression in the host organism. Two heterologous expression systems used up to now have several advantages. However they are not free from some drawbacks. In this work we use bacterium Shewanella oneidensis as a new and efficient system for expression and maturation of HydA1 from Chlamydomonas reinhardtii. Results Based on codon usage bias and hydrogenase maturation ability, the bacterium S. oneidensis, which possesses putative [Fe-Fe] and [Ni-Fe] hydrogenase operons, was selected as the best potential host for C. reinhardtii [Fe-Fe] hydrogenase expression. Hydrogen formation by S. oneidensis strain AS52 (ΔhydAΔhyaB transformed with a plasmid bearing CrHydA1 and grown in the presence of six different substrates for anaerobic respiration was determined. A significant increase in hydrogen evolution was observed for cells grown in the presence of trimethylamine oxide, dimethylsulfoxide and disodium thiosulfate, showing that the system of S. oneidensis is efficient for heterologous expression of algal [Fe-Fe] hydrogenase. Conclusion In the present work a new efficient system for heterologous expression and maturation of C. reinhardtii hydrogenase has been developed. HydA1 of C. reinhardtii was purified and shown to contain 6 Fe atoms/molecule of protein, as expected. Using DMSO, TMAO or thiosulfate as substrates for anaerobic respiration during the cell growth, 0.4 – 0.5 mg l-1(OD600 = 1 of catalytically active HydA1 was obtained with hydrogen evolution rate of ~700 μmol H2 mg-1 min-1.

  2. Construction of a Shuttle Vector for Heterologous Expression of a Novel Fungal α-Amylase Gene in Aspergillus oryzae.

    Science.gov (United States)

    Yin, Yanchen; Mao, Youzhi; Yin, Xiaolie; Gao, Bei; Wei, Dongzhi

    2015-07-01

    The filamentous fungus Aspergillus oryzae is a well-known expression host used to express homologous and heterologous proteins in a number of industrial applications. To facilitate higher yields of proteins of interest, we constructed the pAsOP vector to express heterologous proteins in A. oryzae. pAsOP carries a selectable marker, pyrG, derived from Aspergillus nidulans, and a strong promoter and a terminator of the amyB gene derived from A. oryzae. pAsOP transformed A. oryzae efficiently via the PEG-CaCl2-mediated transformation method. As proof of concept, green fluorescent protein (GFP) was successfully expressed in A. oryzae transformed by pAsOP-GFP. Additionally, we identified a novel fungal α-amylase (PcAmy) gene from Penicillium sp. and cloned the gene into the vector. After transformation by pAsOPPcAmy, the α-amylase PcAmy from Penicillium sp. was successfully expressed in a heterologous host system for the first time. The α-amylase activity in the A. oryzae transformant was increased by 62.3% compared with the untransformed A. oryzae control. The PcAmy protein produced in the system had an optimum pH of 5.0 and optimum temperature of 30°C. As a cold-adapted enzyme, PcAmy shows potential value in industrial applications because of its high catalytic activity at low temperature. Furthermore, the expression vector reported in this study provides promising utility for further scientific research and biotechnological applications.

  3. Cell surface expression system for the display of heterologous gene products using chimeric flagellin fusions of bacillus halodurans isolate

    CSIR Research Space (South Africa)

    Du Plessis, A

    2006-10-01

    Full Text Available system for the display of heterologous gene products using chimeric flagellin fusions of a Bacillus halodurans isolate Slide 2 © CSIR 2006 www.csir.co.za Bacillus halodurans Alk 36 xrhombus Ability to over-produce cell... for functionality of the His-tag for metal binding. Slide 13 © CSIR 2006 www.csir.co.za PAGE gel showing over-production of chimeric poly-His flagellin proteins 66.2 kDa 45.0 kDa 31.0 kDa 1. LMW ladder 2. NC3 3. NHisC3 4. NC6 5...

  4. Chimeric FimH adhesin of type 1 fimbriae: a bacterial surface display system for heterologous sequences

    DEFF Research Database (Denmark)

    Pallesen, L; Poulsen, LK; Christiansen, Gunna

    1995-01-01

    of heterologous DNA segments encoding two reporter sequences. In the selected positions such insertions did not significantly alter the function of the FimH protein with regard to surface location and adhesive ability. The system seemed to be quite flexible, since chimeric versions of the FimH adhesin containing...... as many as 56 foreign amino acids were transported to the bacterial surface as components of the fimbrial organelles. Furthermore, the foreign protein segments were recognized by insert-specific antibodies when expressed within chimeric proteins on the surface of the bacteria. The results from...

  5. ABO hemolytic disease of the fetus and newborn: an iatrogenic complication of heterologous assisted reproductive technology-induced pregnancy.

    Science.gov (United States)

    Zuppa, Antonio Alberto; Cardiello, Valentina; Lai, Marco; Cataldi, Luigi; D'Andrea, Vito; Romagnoli, Costantino

    2010-10-01

    ABO hemolytic disease of the fetus and newborn (ABO HDFN) may manifest itself in cases of mothers belonging to blood group O and newborns of groups A or B and more frequently in group A and less so in group B. The case subjects are twin-birth newborns with ABO HDFN, of group AB born to a mother of group O. These cases of ABO HDFN prove inconsistent with Mendel's law of segregation. This case study finds its explanation in new methods of assisted reproduction, particularly heterologous in vitro fertilization with ovodonation. © 2010 American Association of Blood Banks.

  6. Markerless gene knockout and integration to express heterologous biosynthetic gene clusters in Pseudomonas putida

    DEFF Research Database (Denmark)

    Choi, Kyeong Rok; Cho, Jae Sung; Cho, In Jin

    2018-01-01

    Pseudomonas putida has gained much interest among metabolic engineers as a workhorse for producing valuable natural products. While a few gene knockout tools for P. putida have been reported, integration of heterologous genes into the chromosome of P. putida, an essential strategy to develop stable...... plasmid curing systems, generating final strains free of antibiotic markers and plasmids. This markerless recombineering system for efficient gene knockout and integration will expedite metabolic engineering of P. putida, a bacterial host strain of increasing academic and industrial interest....

  7. Heterologous aggregates promote de novo prion appearance via more than one mechanism.

    Directory of Open Access Journals (Sweden)

    Fatih Arslan

    2015-01-01

    Full Text Available Prions are self-perpetuating conformational variants of particular proteins. In yeast, prions cause heritable phenotypic traits. Most known yeast prions contain a glutamine (Q/asparagine (N-rich region in their prion domains. [PSI+], the prion form of Sup35, appears de novo at dramatically enhanced rates following transient overproduction of Sup35 in the presence of [PIN+], the prion form of Rnq1. Here, we establish the temporal de novo appearance of Sup35 aggregates during such overexpression in relation to other cellular proteins. Fluorescently-labeled Sup35 initially forms one or a few dots when overexpressed in [PIN+] cells. One of the dots is perivacuolar, colocalizes with the aggregated Rnq1 dot and grows into peripheral rings/lines, some of which also colocalize with Rnq1. Sup35 dots that are not near the vacuole do not always colocalize with Rnq1 and disappear by the time rings start to grow. Bimolecular fluorescence complementation failed to detect any interaction between Sup35-VN and Rnq1-VC in [PSI+][PIN+] cells. In contrast, all Sup35 aggregates, whether newly induced or in established [PSI+], completely colocalize with the molecular chaperones Hsp104, Sis1, Ssa1 and eukaryotic release factor Sup45. In the absence of [PIN+], overexpressed aggregating proteins such as the Q/N-rich Pin4C or the non-Q/N-rich Mod5 can also promote the de novo appearance of [PSI+]. Similar to Rnq1, overexpressed Pin4C transiently colocalizes with newly appearing Sup35 aggregates. However, no interaction was detected between Mod5 and Sup35 during [PSI+] induction in the absence of [PIN+]. While the colocalization of Sup35 and aggregates of Rnq1 or Pin4C are consistent with the model that the heterologous aggregates cross-seed the de novo appearance of [PSI+], the lack of interaction between Mod5 and Sup35 leaves open the possibility of other mechanisms. We also show that Hsp104 is required in the de novo appearance of [PSI+] aggregates in a [PIN

  8. Heterologous amyloid seeding: revisiting the role of acetylcholinesterase in Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Létitia Jean

    2007-07-01

    for observations that implicate hAChE in the extent of Abeta deposition in the brain. Furthermore, this process of heterologous amyloid seeding by a proteolytic fragment from another protein may represent a previously underestimated pathological trigger, implying that the abundance of the major amyloidogenic species (Abeta in AD, for example may not be the only important factor in neurodegeneration.

  9. Heterologous expression of a tannic acid-inducible laccase3 of Cryphonectria parasitica in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Kim Dae-Hyuk

    2010-02-01

    Full Text Available Abstract Background A tannic acid-inducible and mycoviral-regulated laccase3 (lac3 from the chestnut blight fungus Cryphonectria parasitica has recently been identified, but further characterization was hampered because of the precipitation of protein products by tannic acid supplementation. The present study investigated the heterologous expression of the functional laccase3 using a yeast Saccharomyces cerevisiae. Results Laccase activity in the culture broth of transformants measured using a laccase-specific substrate suggested that the lac3 gene was successfully expressed and the corresponding protein product secreted into the culture media. In addition, activity staining and Western blot analysis of a native gel revealed that the enzyme activity co-existed with the protein product specific to anti-laccase3 antibody, confirming that the cloned lac3 gene is responsible for the laccase activity. When transformants were grown on plates containing tannic acid-supplemented media, brown coloration was observed around transformed cells, indicating the oxidation of tannic acid. However, the enzymatic activity was measurable only in the selective ura- media and was negligible in nonselective nutrient-rich culture conditions. This was in part because of the increased plasmid instability in the nonselective media. Moreover, the protein product of lac3 appears to be sensitive to the cultured nonselective nutrient-rich broth, because a rapid decline in enzymatic activity was observed when the cultured broth of ura- media was mixed with that of nonselective nutrient-rich broth. In addition, constitutive expression of the lac3 gene resulted in a reduced cell number of the lac3 transformants compared to that of vector-only transformed control. However, the presence of recombinant vector without lac3 induction did not affect the growth of transformants. Conclusions The results suggest that expression of the lac3 gene has an inhibitory effect on the growth of

  10. Gene transfer of heterologous G protein-coupled receptors to cardiomyocytes: differential effects on contractility.

    Science.gov (United States)

    Laugwitz, K L; Weig, H J; Moretti, A; Hoffmann, E; Ueblacker, P; Pragst, I; Rosport, K; Schömig, A; Ungerer, M

    2001-04-13

    In heart failure, reduced cardiac contractility is accompanied by blunted cAMP responses to beta-adrenergic stimulation. Parathyroid hormone (PTH)-related peptide and arginine vasopressin are released from the myocardium in response to increased wall stress but do not stimulate contractility or adenylyl cyclase at physiological concentrations. To bypass the defective beta-adrenergic signaling cascade, recombinant P1 PTH/PTH-related peptide receptors (rPTH1-Rs) and V(2) vasopressin receptors (rV(2)-Rs), which are normally not expressed in the myocardium and which are both strongly coupled to adenylyl cyclase, and recombinant beta(2)-adrenergic receptors (rbeta(2)-ARs) were overexpressed in cardiomyocytes by viral gene transfer. The capacity of endogenous hormones to increase contractility via the heterologous, recombinant receptors was compared. Whereas V(2)-Rs are uniquely coupled to Gs, PTH1-Rs and beta(2)-ARs are also coupled to other G proteins. Gene transfer of rPTH1-Rs or rbeta(2)-ARs to adult cardiomyocytes resulted in maximally increased basal contractility, which could not be further stimulated by adding receptor agonists. Agonists at rPTH1-Rs induced increased cAMP formation and phospholipase C activity. In contrast, healthy or failing rV(2)-R-expressing cardiomyocytes showed unaltered basal contractility. Their contractility and cAMP formation increased only at agonist exposure, which did not activate phospholipase C. In summary, we found that gene transfer of PTH1-Rs to cardiomyocytes results in constitutive activity of the transgene, as does that of beta(2)-ARS: In the absence of receptor agonists, rPTH1-Rs and rbeta(2)-ARs increase basal contractility, coupling to 2 G proteins simultaneously. In contrast, rV(2)-Rs are uniquely coupled to Gs and are not constitutively active, retaining their property to be activated exclusively on agonist stimulation. Therefore, gene transfer of V(2)-Rs might be more suited to test the effects of c

  11. Heterologous radioimmunoassays for monkey gonadotrophins. I. Assessment of the reagents proposed for the assay of FSH

    Energy Technology Data Exchange (ETDEWEB)

    Khan, S A; Diczfalusy, E [Reproductive Endocrinology Research Unit, Karolinska sjukhuset, Stockholm

    1983-01-01

    The reliability of the reagents used in heterologous immunoassay procedures for FSH in monkey sera was assessed. Re-investigation of the iodination and purification of the human FSH tracer confirmed the presence of different iodinated molecular species, such as a high molecular weight aggregated material, 'intact' human FSH and subunits. Tracers obtained with the chloramine T procedure were superior to those obtained by the lactoperoxidase method. Purification by cellulose adsorption chromatography resulted in partial dissociation of the intact hormone into free subunits, while Sephadex G-25 chromatography did not yield any subunit-like material. Purification by Ultrogel AcA 54 gave the best separation of the 'intact' iodinated FSH. Binding studies indicated that an anti-ovine FSH (oFSH) serum showed a high degree of binding to 'intact' hFSH, although its binding to subunits and to aggregated material was also significant. The highest degree of binding to this antiserum was shown by the 'intact' tracer iodinated with chloramine T and purified sequentially by Sephadex G-25 and Ultrogel (AcA 54) chromatography. Using a highly purified hFSH tracer in combination with three antisera (anti-oFSH, H 31; anti-hFSH, WHO, M-93-2; anti-hFSH, NIH, batch No. 5) displacement curves were investigated with three purified monkey FSH preparations. No displacement was observed with a widely available anti-hFSH (WHO, M 93-2) serum. However, linear dose dependent displacement was found with another anti-hFSH (NIH, batch No. 5) serum and with an anti-oFSH (H 31) serum. Comparison of immunoassay with the human and ovine antiserum revealed significant differences in slope, parallelism, precision and effective range. Significant discrepancies in the FSH potency estimates in monkey sera were also observed with the two assay systems. It is suggested that - until a homologous system is developed - the immunoassay employing an hFSH tracer and an anti-oFSH serum should be used for macaque FSH.

  12. Enhanced heterologous protein productivity by genome reduction in Lactococcus lactis NZ9000.

    Science.gov (United States)

    Zhu, Duolong; Fu, Yuxin; Liu, Fulu; Xu, Haijin; Saris, Per Erik Joakim; Qiao, Mingqiang

    2017-01-03

    The implementation of novel chassis organisms to be used as microbial cell factories in industrial applications is an intensive research field. Lactococcus lactis, which is one of the most extensively studied model organisms, exhibits superior ability to be used as engineered host for fermentation of desirable products. However, few studies have reported about genome reduction of L. lactis as a clean background for functional genomic studies and a model chassis for desirable product fermentation. Four large nonessential DNA regions accounting for 2.83% in L. lactis NZ9000 (L. lactis 9 k) genome (2,530,294 bp) were deleted using the Cre-loxP deletion system as the first steps toward a minimized genome in this study. The mutants were compared with the parental strain in several physiological traits and evaluated as microbial cell factories for heterologous protein production (intracellular and secretory expression) with the red fluorescent protein (RFP) and the bacteriocin leucocin C (LecC) as reporters. The four mutants grew faster, yielded enhanced biomass, achieved increased adenosine triphosphate content, and diminished maintenance demands compared with the wild strain in the two media tested. In particular, L. lactis 9 k-4 with the largest deletion was identified as the optimum candidate host for recombinant protein production. With nisin induction, not only the transcriptional efficiency but also the production levels of the expressed reporters were approximately three- to fourfold improved compared with the wild strain. The expression of lecC gene controlled with strong constitutive promoters P5 and P8 in L. lactis 9 k-4 was also improved significantly. The genome-streamlined L. lactis 9 k-4 outcompeted the parental strain in several physiological traits assessed. Moreover, L. lactis 9 k-4 exhibited good properties as platform organism for protein production. In future works, the genome of L. lactis will be maximally reduced by using our specific design

  13. Poliovirus and other enteroviruses in children infected with intestinal parasites in Nigeria.

    Science.gov (United States)

    Adekolujo, Daniel R; Olayinka, Suraj O; Adeniji, Johnson A; Oyeyemi, Oyetunde T; Odaibo, Alexander B

    2015-10-29

    Poliovirus, an enterovirus, still persists in Nigeria despite the global efforts tailored towards its eradication. This study aimed to assess the impacts of poliovirus and other enteroviruses on the susceptibility of individuals to intestinal parasite infections. A cross-sectional study on the prevalence of intestinal parasites was conducted on two-sample stool specimens of 717 Nigerian children (between 1 and 19 years of age) whose poliovirus/other enteroviruses infection status had been determined. The overall prevalence of Sabin poliovirus and other related enteroviruses infections were 6.6% and 13.8%, respectively. The prevalence of Ascaris lumbricoides was significantly higher than that of other intestinal parasites (p parasitic infection (OR = 11.7, CI = 9.2-15.0). While the prevalence of all species of parasites except S. mansoni showed no significant variations in children with Sabin poliovirus (p > 0.05), the prevalence of hookworms and Taenia spp. was significantly higher in children with other enteroviral infections (p parasites is an indication of possible association of the parasites in a more poliovirus-endemic population. A combined intervention approach for the two infections is advocated.

  14. Height, zinc and soil-transmitted helminth infections in schoolchildren: a study in Cuba and Cambodia.

    Science.gov (United States)

    de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim; van der Werff, Suzanne D; D'Haese, Patrick C; Fiorentino, Marion; Khov, Kuong; Perignon, Marlene; Chamnan, Chhoun; Berger, Jacques; Parker, Megan E; Díaz, Raquel Junco; Núñez, Fidel Angel; Rivero, Lázara Rojas; Gorbea, Mariano Bonet; Doak, Colleen M; Ponce, Maiza Campos; Wieringa, Frank T; Polman, Katja

    2015-04-20

    Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris trichiura infections. In Cambodia, STH prevalence was 16.8%, mostly caused by hookworm. In Cuban children, STH infection had a strong association with height for age (aB-0.438, p = 0.001), while hair zinc was significantly associated with height for age only in STH uninfected children. In Cambodian children, plasma zinc was associated with height for age (aB-0.033, p = 0.029), but STH infection was not. Only in Cambodia, STH infection showed an association with zinc concentration (aB-0.233, p = 0.051). Factors influencing child growth differ between populations and may depend on prevalences of STH species and zinc deficiency. Further research is needed to elucidate these relationships and their underlying mechanisms.

  15. Antibodies to variable Plasmodium falciparum-infected erythrocyte surface antigens are associated with protection from novel malaria infections

    DEFF Research Database (Denmark)

    Giha, H A; Staalsoe, T; Dodoo, D

    2000-01-01

    is maintained at low densities. Here, we test the hypothesis that the presence or absence of antibodies against variant antigens on the surface of P. falciparum-infected erythrocytes protect individuals against some infectious challenges and render them susceptible to others. Plasma collected in Daraweesh...... susceptible and protected individuals. Together, the results indicate that pre-existing anti-PfEMP1 antibodies can reduce the risk of contracting clinical malaria when challenged by novel parasite clones expressing homologous, but not heterologous variable surface antigens. The results also confirm...

  16. Reduced expression of Autographa californica nucleopolyhedrovirus ORF34, an essential gene, enhances heterologous gene expression

    International Nuclear Information System (INIS)

    Salem, Tamer Z.; Zhang, Fengrui; Thiem, Suzanne M.

    2013-01-01

    Autographa californica multiple nucleopolyhedrovirus ORF34 is part of a transcriptional unit that includes ORF32, encoding a viral fibroblast growth factor (FGF) and ORF33. We identified ORF34 as a candidate for deletion to improve protein expression in the baculovirus expression system based on enhanced reporter gene expression in an RNAi screen of virus genes. However, ORF34 was shown to be an essential gene. To explore ORF34 function, deletion (KO34) and rescue bacmids were constructed and characterized. Infection did not spread from primary KO34 transfected cells and supernatants from KO34 transfected cells could not infect fresh Sf21 cells whereas the supernatant from the rescue bacmids transfection could recover the infection. In addition, budded viruses were not observed in KO34 transfected cells by electron microscopy, nor were viral proteins detected from the transfection supernatants by western blots. These demonstrate that ORF34 is an essential gene with a possible role in infectious virus production.

  17. Reduced expression of Autographa californica nucleopolyhedrovirus ORF34, an essential gene, enhances heterologous gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Salem, Tamer Z. [Department of Entomology, Michigan State University, East Lansing, MI 48824 (United States); Department of Microbial Molecular Biology, AGERI, Agricultural Research Center, Giza 12619 (Egypt); Division of Biomedical Sciences, Zewail University, Zewail City of Science and Technology, Giza 12588 (Egypt); Zhang, Fengrui [Department of Entomology, Michigan State University, East Lansing, MI 48824 (United States); Thiem, Suzanne M., E-mail: smthiem@msu.edu [Department of Entomology, Michigan State University, East Lansing, MI 48824 (United States); Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824 (United States)

    2013-01-20

    Autographa californica multiple nucleopolyhedrovirus ORF34 is part of a transcriptional unit that includes ORF32, encoding a viral fibroblast growth factor (FGF) and ORF33. We identified ORF34 as a candidate for deletion to improve protein expression in the baculovirus expression system based on enhanced reporter gene expression in an RNAi screen of virus genes. However, ORF34 was shown to be an essential gene. To explore ORF34 function, deletion (KO34) and rescue bacmids were constructed and characterized. Infection did not spread from primary KO34 transfected cells and supernatants from KO34 transfected cells could not infect fresh Sf21 cells whereas the supernatant from the rescue bacmids transfection could recover the infection. In addition, budded viruses were not observed in KO34 transfected cells by electron microscopy, nor were viral proteins detected from the transfection supernatants by western blots. These demonstrate that ORF34 is an essential gene with a possible role in infectious virus production.

  18. Heterologous and endogenous U6 snRNA promoters enable CRISPR/Cas9 mediated genome editing in Aspergillus niger.

    Science.gov (United States)

    Zheng, Xiaomei; Zheng, Ping; Sun, Jibin; Kun, Zhang; Ma, Yanhe

    2018-01-01

    U6 promoters have been used for single guide RNA (sgRNA) transcription in the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas9) genome editing system. However, no available U6 promoters have been identified in Aspergillus niger, which is an important industrial platform for organic acid and protein production. Two CRISPR/Cas9 systems established in A. niger have recourse to the RNA polymerase II promoter or in vitro transcription for sgRNA synthesis, but these approaches generally increase cloning efforts and genetic manipulation. The validation of functional RNA polymerase II promoters is therefore an urgent need for A. niger . Here, we developed a novel CRISPR/Cas9 system in A. niger for sgRNA expression, based on one endogenous U6 promoter and two heterologous U6 promoters. The three tested U6 promoters enabled sgRNA transcription and the disruption of the polyketide synthase albA gene in A. niger . Furthermore, this system enabled highly efficient gene insertion at the targeted genome loci in A. niger using donor DNAs with homologous arms as short as 40-bp. This study demonstrated that both heterologous and endogenous U6 promoters were functional for sgRNA expression in A. niger . Based on this result, a novel and simple CRISPR/Cas9 toolbox was established in A. niger, that will benefit future gene functional analysis and genome editing.

  19. Ectopic expression of MPF2-like protein WSA206 leads to arrest in silique and seed development in heterologous host

    International Nuclear Information System (INIS)

    Khan, M.R.

    2016-01-01

    MPF2-like genes belonging to STMADS11 clade of MADS-box transcription factors are mostly involved in calyx inflation, floral reversion and fertility. However their role in fertility remained enigmatic. In this study we transformed WSA206 gene paralog - originated through genome duplication in a Solanaceous plant Withaniasomnifera - ectopically in a heterologous host Arabidopsis thaliana. Interesting phenotypes in floral organs and fruits were observed. Overexpression of WSA206 leads to arrest in silique development. The siliques were compressed and size was drastically reduced from 34mm to 3mm. Along with siliques, the seed development was also suppressed as revealed by shriveling of seeds and reduction in seed number. In extreme cases the siliques were devoid of any seeds. In cases where seeds developed, these were impaired in viability. Besides, the transgenic Arabidopsis also exhibited exorbitant growth of calyx to an extent that it resembled inflated calyx in Solanaceae. The calyx remained persistent and encapsulated the under-developed siliques containing non-viable seeds inside. Thus, fertility and sepal development are tightly coupled traits that are controlled by WSA206 paralog in heterologous system. (author)

  20. Acid-sensing ion channel (ASIC) 4 predominantly localizes to an early endosome-related organelle upon heterologous expression.

    Science.gov (United States)

    Schwartz, Verena; Friedrich, Katharina; Polleichtner, Georg; Gründer, Stefan

    2015-12-15

    Acid-sensing ion channels (ASICs) are voltage-independent proton-gated amiloride sensitive sodium channels, belonging to the DEG/ENaC gene family. Six different ASICs have been identified (ASIC1a, ASIC1b, ASIC2a, ASIC2b, ASIC3, ASIC4) that are activated by a drop in extracellular pH, either as homo- or heteromers. An exception is ASIC4, which is not activated by protons as a homomer and which does not contribute to functional heteromeric ASICs. Insensitivity of ASIC4 to protons and its comparatively low sequence identity to other ASICs (45%) raises the question whether ASIC4 may have different functions than other ASICs. In this study, we therefore investigated the subcellular localization of ASIC4 in heterologous cell lines, which revealed a surprising accumulation of the channel in early endosome-related vacuoles. Moreover, we identified an unique amino-terminal motif as important for forward-trafficking from the ER/Golgi to the early endosome-related compartment. Collectively, our results show that heterologously expressed ASIC4 predominantly resides in an intracellular endosomal compartment.

  1. [Tetanus prevention with vaccine and with vaccine plus heterologous immune serum: serum antibody levels in the rabbit].

    Science.gov (United States)

    Bistoni, F; Mosci, L; Vecchiarelli, A; Marconi, P; Pitzurra, M

    1977-01-01

    Haemagglutinating antibodies have been assessed in rabbits undergoing active- passive immunization against tetanus. The animals received 6 injections of horse immune serum, 400 UI/kg, and A1PO4 adsorbed toxoid, 0.35 Lf/kg, every 30th day. One the 5th day, after the first injection, E.A. antibodies appeared, at low levels, as a result of a passive immunization. Thereafter the tests became negative, up to the 70th day, when an active immunization emerged, with a 25 days delay in comparison with controls. Neutralization test in vivo behaved in the same way. The results stress once more the need to give up the use of heterologous immune sera in tetanus prophylaxis, in active-passive immunization as well. Arguments adding force to this point of view are: the sensibilization against heterologous proteins, the very low (if any) passive protective action, and, last not least, the delay in the emergence of active immunization: the only reliable shield against tetanus.

  2. Recombinant vaccines against T. gondii: comparison between homologous and heterologous vaccination protocols using two viral vectors expressing SAG1.

    Science.gov (United States)

    Mendes, Érica Araújo; Fonseca, Flavio G; Casério, Bárbara M; Colina, Janaína P; Gazzinelli, Ricardo Tostes; Caetano, Braulia C

    2013-01-01

    The use of recombinant viral vectors expressing T. gondii antigens is a safe and efficient approach to induce immune response against the parasite and a valuable tool for vaccine development. We have previously protected mice from toxoplasmosis by immunizing the animals with an adenovirus expressing the protein SAG1 (AdSAG1) of T. gondii. We are now looking for ways to improve the vaccination strategy and enhance protection. One limitation of homologous vaccinations (sequential doses of the same vector) is induction of anti-vector immune response that blocks cell transduction, restricts transgene expression and, consequently, compromises the overall outcome of vaccination. One way to avert the effects of anti-vector response is to use different viruses in prime and boost (heterologous vaccination). Bearing this in mind, we generated a modified Vaccinia Virus Ankara encoding SAG1 (MVASAG1), to be tested as boost agent after prime with AdSAG1. Although minor differences were observed in the magnitude of the anti-SAG1 immune response induced by each vaccination protocol, the heterologous immunization with AdSAG1 followed by MVASAG1 resulted in improved capacity to control brain cyst formation in a model of chronic toxoplasmosis in C57BL/6 mice.

  3. Recombinant vaccines against T. gondii: comparison between homologous and heterologous vaccination protocols using two viral vectors expressing SAG1.

    Directory of Open Access Journals (Sweden)

    Érica Araújo Mendes

    Full Text Available The use of recombinant viral vectors expressing T. gondii antigens is a safe and efficient approach to induce immune response against the parasite and a valuable tool for vaccine development. We have previously protected mice from toxoplasmosis by immunizing the animals with an adenovirus expressing the protein SAG1 (AdSAG1 of T. gondii. We are now looking for ways to improve the vaccination strategy and enhance protection. One limitation of homologous vaccinations (sequential doses of the same vector is induction of anti-vector immune response that blocks cell transduction, restricts transgene expression and, consequently, compromises the overall outcome of vaccination. One way to avert the effects of anti-vector response is to use different viruses in prime and boost (heterologous vaccination. Bearing this in mind, we generated a modified Vaccinia Virus Ankara encoding SAG1 (MVASAG1, to be tested as boost agent after prime with AdSAG1. Although minor differences were observed in the magnitude of the anti-SAG1 immune response induced by each vaccination protocol, the heterologous immunization with AdSAG1 followed by MVASAG1 resulted in improved capacity to control brain cyst formation in a model of chronic toxoplasmosis in C57BL/6 mice.

  4. A simple model-based control for Pichia pastoris allows a more efficient heterologous protein production bioprocess.

    Science.gov (United States)

    Cos, Oriol; Ramon, Ramon; Montesinos, José Luis; Valero, Francisco

    2006-09-05

    A predictive control algorithm coupled with a PI feedback controller has been satisfactorily implemented in the heterologous Rhizopus oryzae lipase production by Pichia pastoris methanol utilization slow (Mut(s)) phenotype. This control algorithm has allowed the study of the effect of methanol concentration, ranging from 0.5 to 1.75 g/L, on heterologous protein production. The maximal lipolytic activity (490 UA/mL), specific yield (11,236 UA/g(biomass)), productivity (4,901 UA/L . h), and specific productivity (112 UA/g(biomass)h were reached for a methanol concentration of 1 g/L. These parameters are almost double than those obtained with a manual control at a similar methanol set-point. The study of the specific growth, consumption, and production rates showed different patterns for these rates depending on the methanol concentration set-point. Results obtained have shown the need of implementing a robust control scheme when reproducible quality and productivity are sought. It has been demonstrated that the model-based control proposed here is a very efficient, robust, and easy-to-implement strategy from an industrial application point of view. (c) 2006 Wiley Periodicals, Inc.

  5. Introduction of caveolae structural proteins into the protozoan Toxoplasma results in the formation of heterologous caveolae but not caveolar endocytosis.

    Directory of Open Access Journals (Sweden)

    Bao Lige

    Full Text Available Present on the plasma membrane of most metazoans, caveolae are specialized microdomains implicated in several endocytic and trafficking mechanisms. Caveolins and the more recently discovered cavins are the major protein components of caveolae. Previous studies reported that caveolar invaginations can be induced de novo on the surface of caveolae-negative mammalian cells upon heterologous expression of caveolin-1. However, it remains undocumented whether other components in the transfected cells participate in caveolae formation. To address this issue, we have exploited the protozoan Toxoplasma as a heterologous expression system to provide insights into the minimal requirements for caveogenesis and caveolar endocytosis. Upon expression of caveolin-1, Toxoplasma accumulates prototypical exocytic caveolae 'precursors' in the cytoplasm. Toxoplasma expressing caveolin-1 alone, or in conjunction with cavin-1, neither develops surface-located caveolae nor internalizes caveolar ligands. These data suggest that the formation of functional caveolae at the plasma membrane in Toxoplasma and, by inference in all non-mammalian cells, requires effectors other than caveolin-1 and cavin-1. Interestingly, Toxoplasma co-expressing caveolin-1 and cavin-1 displays an impressive spiraled network of membranes containing the two proteins, in the cytoplasm. This suggests a synergistic activity of caveolin-1 and cavin-1 in the morphogenesis and remodeling of membranes, as illustrated for Toxoplasma.

  6. Neonatal BCG vaccination is associated with enhanced T-helper 1 immune responses to heterologous infant vaccines

    Directory of Open Access Journals (Sweden)

    Daniel H. Libraty

    2014-01-01

    Full Text Available Neonatal Bacille Calmette Guérin (BCG vaccination has been reported to have beneficial effects beyond preventing infantile tuberculous meningitis and miliary disease. We hypothesized that BCG vaccine given at birth would enhance T-helper 1 (Th1 immune responses to the first vaccines given later in infancy. We conducted a nested case-control study of neonatal BCG vaccination and its heterologous Th1 immune effects in 2–3 months old infants. BCG vaccination at birth was associated with an increased frequency of interferon-γ (IFN-γ producing spot-forming cells (SFC to tetanus toxoid 2–3 months later. The frequency of IFN-γ producing SFC to polioviruses 1–3 also trended higher among infants who received BCG vaccination at birth. The frequency of IFN-γ+/tumor necrosis factor-α (TNF-α+CD45RO+CD4+ T-cells upon stimulation with phorbol myristate acetate (PMA/Ionomycin was higher in 2–3 months old infants who received BCG vaccination at birth compared to those who did not. The circulating frequency of forkhead box P3 (FoxP3+ CD45RO+ regulatory CD4+ T-cells also trended lower in these infants. Neonatal BCG vaccination is associated with heterologous Th1 immune effects 2–3 months later.