Giardia lamblia: identification of molecules that contribute to direct mast cell activation.

PubMed

Muñoz-Cruz, Samira; Gomez-García, Argelia; Matadamas-Martínez, Félix; Alvarado-Torres, Juan A; Meza-Cervantez, Patricia; Arriaga-Pizano, Lourdes; Yépez-Mulia, Lilián

2018-06-02

Mast cells play a central role in the early clearance of the intestinal parasite Giardia lamblia. In a previous study, we reported that G. lamblia live trophozoites or trophozoite-derived total soluble extract induced direct activation (IgE-independent) of mast cells and release of IL-6 and TNF-α. To identify the Giardia molecules and the mast cell receptors involved in this activation, trophozoite-derived total soluble proteins separated into three fractions (F1-F3) were evaluated for its ability to activate mast cells in vitro. F2 activated mast cells in a greater extent than F1 and F3. Furthermore, F2 induced the release of IL-6 and TNF-α by mast cells. TLR2 and TLR4 expression increased slightly after mast cell stimulation with either F2 or total soluble extract; however, these receptors were not involved in F2 or total soluble extract-induced proinflammatory cytokine production. Proteins present in F2 as unique and high-intensity bands identified by liquid chromatography coupled with tandem mass spectrometry, include molecules with important biological activities such as enolase and arginine deiminase (ADI). Recombinant ADI and enolase were tested for their ability to activate mast cells, but only ADI induced a significant release of IL-6 and TNF-α. ADI product, citrulline but not ammonium, also induced mast cell release of TNF-α. Interestingly, recombinant ADI still stimulated the secretion of TNF-α by mast cells in a arginine-free medium, although in a lower extend that in the presence of arginine, indicating that either ADI itself can stimulate mast cells or through its metabolic product, citrulline.

Comparative analysis of the 5S rRNA and its associated proteins reveals unique primitive rather than parasitic features in Giardia lamblia.

PubMed

Feng, Jin-Mei; Sun, Jun; Xin, De-Dong; Wen, Jian-Fan

2012-01-01

5S rRNA is a highly conserved ribosomal component. Eukaryotic 5S rRNA and its associated proteins (5S rRNA system) have become very well understood. Giardia lamblia was thought by some researchers to be the most primitive extant eukaryote while others considered it a highly evolved parasite. Previous reports have indicated that some aspects of its 5S rRNA system are simpler than that of common eukaryotes. We here explore whether this is true to its entire system, and whether this simplicity is a primitive or parasitic feature. By collecting and confirming pre-existing data and identifying new data, we obtained almost complete datasets of the system of three isolates of G. lamblia, two other parasitic excavates (Trichomonas vaginalis, Trypanosoma cruzi), and one free-living one (Naegleria gruberi). After comprehensively comparing each aspect of the system among these excavates and also with those of archaea and common eukaryotes, we found all the three Giardia isolates to harbor a same simplified 5S rRNA system, which is not only much simpler than that of common eukaryotes but also the simplest one among those of these excavates, and is surprisingly very similar to that of archaea; we also found among these excavates the system in parasitic species is not necessarily simpler than that in free-living species, conversely, the system of free-living species is even simpler in some respects than those of parasitic ones. The simplicity of Giardia 5S rRNA system should be considered a primitive rather than parasitically-degenerated feature. Therefore, Giardia 5S rRNA system might be a primitive system that is intermediate between that of archaea and the common eukaryotic model system, and it may reflect the evolutionary history of the eukaryotic 5S rRNA system from the archaeal form. Our results also imply G. lamblia might be a primitive eukaryote with secondary parasitically-degenerated features.

Azasterols impair Giardia lamblia proliferation and induces encystation

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

Maia, Claudia; Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, Rio de Janeiro; Attias, Marcia

2007-11-16

The effects of sterol biosynthesis inhibitors on growth and fine structure of Giardia lamblia P1 strain cultures were analyzed. Azasterols demonstrated high efficacy in killing cells. The IC{sub 50} values for 22,26-azasterol and 24(R,S),25-epiminolanosterol were 7 {mu}M and 170 nM, respectively. Morphological analysis showed that azasterols induced changes in G. lamblia ultrastructure. The most significant alterations were: (a) considerable increase of the size of the peripheral vesicles, which are part of the parasite endosomal-lysosomal system; (b) appearance of autophagosomal structures; and (c) induction of differentiation, followed by an abnormal enlargement of encystation secretory vesicles. We propose that azasterols are effectivemore » chemotherapeutic drugs against Giardia lamblia in vitro and may have another target in cells besides sterol biosynthesis.« less

A Multiplex PCR for Simultaneous Detection of Three Zoonotic Parasites Ancylostoma ceylanicum, A. caninum, and Giardia lamblia Assemblage A

PubMed Central

Hu, Wei; Wu, Sheng; Yu, Xingang; Abullahi, Auwalu Yusuf; Song, Meiran; Tan, Liping; Wang, Zhen; Jiang, Biao; Li, Guoqing

2015-01-01

Ancylostoma ceylanicum, A. caninum, and Giardia lamblia assemblage A are common intestinal parasites of dogs and cats; they can also infect humans, causing parasitic zoonoses. In this study, a multiplex PCR method was developed for simultaneous identification and detection of those three zoonotic parasites. Three pairs of specific primers were designed based on ITS sequence of A. ceylanicum and A. caninum and TPI gene of G. lamblia available in the GenBank. The multiplex PCR reaction system was established by optimizing the reaction condition, and a series of tests on the sensitivity, specificity, and clinical application were also conducted. Results showed that three target fragments were amplified specifically; the detection limit was 10 eggs for both A. ceylanicum and A. caninum, 72 pg DNA for G. lamblia. Of 112 clinical fecal samples, 34.8% and 17.8% samples were positive for A. caninum and A. ceylanicum, respectively, while only 2.7% samples were positive for G. lamblia assemblage A. It is concluded that the established multiplex PCR assay is a convenient, rapid, cost-effective, and high-efficiency method for molecular detection and epidemiological investigation of three zoonotic parasites. PMID:26447336

Genome-wide computational identification of microRNAs and their targets in the deep-branching eukaryote Giardia lamblia.

PubMed

Zhang, Yan-Qiong; Chen, Dong-Liang; Tian, Hai-Feng; Zhang, Bao-Hong; Wen, Jian-Fan

2009-10-01

Using a combined computational program, we identified 50 potential microRNAs (miRNAs) in Giardia lamblia, one of the most primitive unicellular eukaryotes. These miRNAs are unique to G. lamblia and no homologues have been found in other organisms; miRNAs, currently known in other species, were not found in G. lamblia. This suggests that miRNA biogenesis and miRNA-mediated gene regulation pathway may evolve independently, especially in evolutionarily distant lineages. A majority (43) of the predicted miRNAs are located at one single locus; however, some miRNAs have two or more copies in the genome. Among the 58 miRNA genes, 28 are located in the intergenic regions whereas 30 are present in the anti-sense strands of the protein-coding sequences. Five predicted miRNAs are expressed in G. lamblia trophozoite cells evidenced by expressed sequence tags or RT-PCR. Thirty-seven identified miRNAs may target 50 protein-coding genes, including seven variant-specific surface proteins (VSPs). Our findings provide a clue that miRNA-mediated gene regulation may exist in the early stage of eukaryotic evolution, suggesting that it is an important regulation system ubiquitous in eukaryotes.

Identification and analysis of the RNA degrading complexes and machinery of Giardia lamblia using an in silico approach.

PubMed

Williams, Christopher W; Elmendorf, Heidi G

2011-11-29

RNA degradation is critical to the survival of all cells. With increasing evidence for pervasive transcription in cells, RNA degradation has gained recognition as a means of regulating gene expression. Yet, RNA degradation machinery has been studied extensively in only a few eukaryotic organisms, including Saccharomyces cerevisiae and humans. Giardia lamblia is a parasitic protist with unusual genomic traits: it is binucleated and tetraploid, has a very compact genome, displays a theme of genomic minimalism with cellular machinery commonly comprised of a reduced number of protein components, and has a remarkably large population of long, stable, noncoding, antisense RNAs. Here we use in silico approaches to investigate the major RNA degradation machinery in Giardia lamblia and compare it to a broad array of other parasitic protists. We have found key constituents of the deadenylation and decapping machinery and of the 5'-3' RNA degradation pathway. We have similarly found that all of the major 3'-5' RNA degradation pathways are present in Giardia, including both exosome-dependent and exosome-independent machinery. However, we observe significant loss of RNA degradation machinery genes that will result in important differences in the protein composition, and potentially functionality, of the various RNA degradation pathways. This is most apparent in the exosome, the central mediator of 3'-5' degradation, which apparently contains an altered core configuration in both Giardia and Plasmodium, with only four, instead of the canonical six, distinct subunits. Additionally the exosome in Giardia is missing both the Rrp6, Nab3, and Nrd1 proteins, known to be key regulators of noncoding transcript stability in other cells. These findings suggest that although the full complement of the major RNA degradation mechanisms were present - and likely functional - early in eukaryotic evolution, the composition and function of the complexes is more variable than previously appreciated. We suggest that the missing components of the exosome complex provide an explanation for the stable abundance of sterile RNA species in Giardia.

INDUCTION OF ALBENDAZOLE RESISTANCE IN GIARDIA LAMBLIA

EPA Science Inventory

Previous studies have shown that Giardia lamblia resistance to metronidazole can be induced in the laboratory, and treatment failures with this drug have also been documented. As replacement theraples, anthelmintic benzimidazoles have antigiardial activity with few clinical side ...

Protein SUMOylation is Involved in Cell-cycle Progression and Cell Morphology in Giardia lamblia.

PubMed

Di Genova, Bruno M; da Silva, Richard C; da Cunha, Júlia P C; Gargantini, Pablo R; Mortara, Renato A; Tonelli, Renata R

2017-07-01

The unicellular protozoa Giardia lamblia is a food- and waterborne parasite that causes giardiasis. This illness is manifested as acute and self-limited diarrhea and can evolve to long-term complications. Successful establishment of infection by Giardia trophozoites requires adhesion to host cells and colonization of the small intestine, where parasites multiply by mitotic division. The tight binding of trophozoites to host cells occurs by means of the ventral adhesive disc, a spiral array of microtubules and associated proteins such as giardins. In this work we show that knock down of the Small Ubiquitin-like MOdifier (SUMO) results in less adhesive trophzoites, decreased cell proliferation and deep morphological alterations, including at the ventral disc. Consistent with the reduced proliferation, SUMO knocked-down trophozoites were arrested in G1 and in S phases of the cell cycle. Mass spectrometry analysis of anti-SUMO immunoprecipitates was performed to identify SUMO substrates possibly involved in these events. Among the identified SUMOylation targets, α-tubulin was further validated by Western blot and confirmed to be a SUMO target in Giardia trophozoites. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Comparison of techniques for detecting antigens of Giardia lamblia and Cryptosporidium parvum in faeces.

PubMed Central

Tee, G H; Moody, A H; Cooke, A H; Chiodini, P L

1993-01-01

AIM--To compare the use of commercial monoclonal antibody test systems--the Giardia CEL IF test and the Crypto CEL IF test--for the detection of Giardia lamblia and Cryptosporidium parvum antigens in faeces with conventional techniques. METHODS--Sensitivity and specificity were evaluated using preparations of cysts of G lamblia and purified oocysts of C parvum. Evaluation of 59 random faecal samples passing through the Department of Clinical Parasitology, Hospital for Tropical Diseases, London, was carried out for both organisms. RESULTS--The fluorescence staining techniques proved more sensitive than other tests routinely used for diagnosis. PMID:8331181

Persistent G. lamblia impairs growth in a murine malnutrition model

PubMed Central

Bartelt, Luther A.; Roche, James; Kolling, Glynis; Bolick, David; Noronha, Francisco; Naylor, Caitlin; Hoffman, Paul; Warren, Cirle; Singer, Steven; Guerrant, Richard

2013-01-01

Giardia lamblia infections are nearly universal among children in low-income countries and are syndemic with the triumvirate of malnutrition, diarrhea, and developmental growth delays. Amidst the morass of early childhood enteropathogen exposures in these populations, G. lamblia–specific associations with persistent diarrhea, cognitive deficits, stunting, and nutrient deficiencies have demonstrated conflicting results, placing endemic pediatric giardiasis in a state of equipoise. Many infections in endemic settings appear to be asymptomatic/subclinical, further contributing to uncertainty regarding a causal link between G. lamblia infection and developmental delay. We used G. lamblia H3 cyst infection in a weaned mouse model of malnutrition to demonstrate that persistent giardiasis leads to epithelial cell apoptosis and crypt hyperplasia. Infection was associated with a Th2-biased inflammatory response and impaired growth. Malnutrition accentuated the severity of these growth decrements. Faltering malnourished mice exhibited impaired compensatory responses following infection and demonstrated an absence of crypt hyperplasia and subsequently blunted villus architecture. Concomitantly, severe malnutrition prevented increases in B220+ cells in the lamina propria as well as mucosal Il4 and Il5 mRNA in response to infection. These findings add insight into the potential role of G. lamblia as a “stunting” pathogen and suggest that, similarly, malnourished children may be at increased risk of G. lamblia–potentiated growth decrements. PMID:23728173

Persistent G. lamblia impairs growth in a murine malnutrition model.

PubMed

Bartelt, Luther A; Roche, James; Kolling, Glynis; Bolick, David; Noronha, Francisco; Naylor, Caitlin; Hoffman, Paul; Warren, Cirle; Singer, Steven; Guerrant, Richard

2013-06-01

Giardia lamblia infections are nearly universal among children in low-income countries and are syndemic with the triumvirate of malnutrition, diarrhea, and developmental growth delays. Amidst the morass of early childhood enteropathogen exposures in these populations, G. lamblia–specific associations with persistent diarrhea, cognitive deficits, stunting, and nutrient deficiencies have demonstrated conflicting results, placing endemic pediatric giardiasis in a state of equipoise. Many infections in endemic settings appear to be asymptomatic/ subclinical, further contributing to uncertainty regarding a causal link between G. lamblia infection and developmental delay. We used G. lamblia H3 cyst infection in a weaned mouse model of malnutrition to demonstrate that persistent giardiasis leads to epithelial cell apoptosis and crypt hyperplasia. Infection was associated with a Th2-biased inflammatory response and impaired growth. Malnutrition accentuated the severity of these growth decrements. Faltering malnourished mice exhibited impaired compensatory responses following infection and demonstrated an absence of crypt hyperplasia and subsequently blunted villus architecture. Concomitantly, severe malnutrition prevented increases in B220+ cells in the lamina propria as well as mucosal Il4 and Il5 mRNA in response to infection. These findings add insight into the potential role of G. lamblia as a "stunting" pathogen and suggest that, similarly, malnourished children may be at increased risk of G. lamblia– potentiated growth decrements.

A Systematic Review and Meta-analysis of the Association Between Giardia lamblia and Endemic Pediatric Diarrhea in Developing Countries

PubMed Central

Muhsen, Khitam; Levine, Myron M.

2012-01-01

We performed a systematic literature review and meta-analysis examining the association between diarrhea in young children in nonindustrialized settings and Giardia lamblia infection. Eligible were case/control and longitudinal studies that defined the outcome as acute or persistent (>14 days) diarrhea, adjusted for confounders and lasting for at least 1 year. Data on G. lamblia detection (mainly in stools) from diarrhea patients and controls without diarrhea were abstracted. Random effects model meta-analysis obtained pooled odds ratios (ORs) and 95% confidence intervals (CIs). Twelve nonindustrialized-setting acute pediatric diarrhea studies met the meta-analysis inclusion criteria. Random-effects model meta-analysis of combined results (9774 acute diarrhea cases and 8766 controls) yielded a pooled OR of 0.60 (95% CI, .38–.94; P = .03), indicating that G. lamblia was not associated with acute diarrhea. However, limited data suggest that initial Giardia infections in early infancy may be positively associated with diarrhea. Meta-analysis of 5 persistent diarrhea studies showed a pooled OR of 3.18 (95% CI, 1.50–6.76; P < .001), positively linking Giardia with that syndrome. The well-powered Global Enteric Multicenter Study (GEMS) is prospectively addressing the association between G. lamblia infection and diarrhea in children in developing countries. PMID:23169940

MODELING INACTIVATION OF GIARDIA LAMBLIA

EPA Science Inventory

Under the auspices of the Safe Drinking Water Act (SDWA)the U.S. EPA hasa promulgated the Surface Water Treatment Rule (SWTR) requiring public water systems using surface water to provide minimum disinfection to Control Giardia Lamblia, enteric virsues, and bacteria. The C-t con...

Comparative Analysis of the 5S rRNA and Its Associated Proteins Reveals Unique Primitive Rather Than Parasitic Features in Giardia lamblia

PubMed Central

Xin, De-Dong; Wen, Jian-Fan

2012-01-01

Background 5S rRNA is a highly conserved ribosomal component. Eukaryotic 5S rRNA and its associated proteins (5S rRNA system) have become very well understood. Giardia lamblia was thought by some researchers to be the most primitive extant eukaryote while others considered it a highly evolved parasite. Previous reports have indicated that some aspects of its 5S rRNA system are simpler than that of common eukaryotes. We here explore whether this is true to its entire system, and whether this simplicity is a primitive or parasitic feature. Methodology/Principal Findings By collecting and confirming pre-existing data and identifying new data, we obtained almost complete datasets of the system of three isolates of G. lamblia, two other parasitic excavates (Trichomonas vaginalis, Trypanosoma cruzi), and one free-living one (Naegleria gruberi). After comprehensively comparing each aspect of the system among these excavates and also with those of archaea and common eukaryotes, we found all the three Giardia isolates to harbor a same simplified 5S rRNA system, which is not only much simpler than that of common eukaryotes but also the simplest one among those of these excavates, and is surprisingly very similar to that of archaea; we also found among these excavates the system in parasitic species is not necessarily simpler than that in free-living species, conversely, the system of free-living species is even simpler in some respects than those of parasitic ones. Conclusion/Significance The simplicity of Giardia 5S rRNA system should be considered a primitive rather than parasitically-degenerated feature. Therefore, Giardia 5S rRNA system might be a primitive system that is intermediate between that of archaea and the common eukaryotic model system, and it may reflect the evolutionary history of the eukaryotic 5S rRNA system from the archaeal form. Our results also imply G. lamblia might be a primitive eukaryote with secondary parasitically-degenerated features. PMID:22685540

Analysis of Giardin expression during encystation of Giardia lamblia

USDA-ARS?s Scientific Manuscript database

The present study analyzed giardin transcription in trophozoites and cysts during encystation of Giardia lamblia. Encystment was induced using standard methods, and the number of trophozoites and cysts were counted at various time-points during encystation. At all time points, RNA from both stages...

Modeling Cryptosporidium spp. Oocyst Inactivation in Bubble-Diffuser Ozone Contactors

DTIC Science & Technology

1998-07-01

requirements for Giardia lamblia (G. lamblia) and viruses under the Surface Water Treatment Rule (SWTR). Minimum CT requirements include relatively...parvum and C. muris ) oocysts in ozone bubble-diffuser contactors. The model is calibrated with semi-batch kinetic data, verified with pilot-scale

Evidence for the bacterial origin of genes encoding fermentation enzymes of the amitochondriate protozoan parasite Entamoeba histolytica.

PubMed

Rosenthal, B; Mai, Z; Caplivski, D; Ghosh, S; de la Vega, H; Graf, T; Samuelson, J

1997-06-01

Entamoeba histolytica is an amitochondriate protozoan parasite with numerous bacterium-like fermentation enzymes including the pyruvate:ferredoxin oxidoreductase (POR), ferredoxin (FD), and alcohol dehydrogenase E (ADHE). The goal of this study was to determine whether the genes encoding these cytosolic E. histolytica fermentation enzymes might derive from a bacterium by horizontal transfer, as has previously been suggested for E. histolytica genes encoding heat shock protein 60, nicotinamide nucleotide transhydrogenase, and superoxide dismutase. In this study, the E. histolytica por gene and the adhE gene of a second amitochondriate protozoan parasite, Giardia lamblia, were sequenced, and their phylogenetic positions were estimated in relation to POR, ADHE, and FD cloned from eukaryotic and eubacterial organisms. The E. histolytica por gene encodes a 1,620-amino-acid peptide that contained conserved iron-sulfur- and thiamine pyrophosphate-binding sites. The predicted E. histolytica POR showed fewer positional identities to the POR of G. lamblia (34%) than to the POR of the enterobacterium Klebsiella pneumoniae (49%), the cyanobacterium Anabaena sp. (44%), and the protozoan Trichomonas vaginalis (46%), which targets its POR to anaerobic organelles called hydrogenosomes. Maximum-likelihood, neighbor-joining, and parsimony analyses also suggested as less likely E. histolytica POR sharing more recent common ancestry with G. lamblia POR than with POR of bacteria and the T. vaginalis hydrogenosome. The G. lamblia adhE encodes an 888-amino-acid fusion peptide with an aldehyde dehydrogenase at its amino half and an iron-dependent (class 3) ADH at its carboxy half. The predicted G. lamblia ADHE showed extensive positional identities to ADHE of Escherichia coli (49%), Clostridium acetobutylicum (44%), and E. histolytica (43%) and lesser identities to the class 3 ADH of eubacteria and yeast (19 to 36%). Phylogenetic analyses inferred a closer relationship of the E. histolytica ADHE to bacterial ADHE than to the G. lamblia ADHE. The 6-kDa FD of E. histolytica and G. lamblia were most similar to those of the archaebacterium Methanosarcina barkeri and the delta-purple bacterium Desulfovibrio desulfuricans, respectively, while the 12-kDa FD of the T. vaginalis hydrogenosome was most similar to the 12-kDa FD of gamma-purple bacterium Pseudomonas putida. E. histolytica genes (and probably G. lamblia genes) encoding fermentation enzymes therefore likely derive from bacteria by horizontal transfer, although it is not clear from which bacteria these amebic genes derive. These are the first nonorganellar fermentation enzymes of eukaryotes implicated to have derived from bacteria.

Cyst acquisition rate for Giardia lamblia in backcountry travelers to Desolation Wilderness, Lake Tahoe

USGS Publications Warehouse

Zell, S.C.; Sorenson, S.K.

1993-01-01

The objective of this study was to determine the incidence of Giardia lamblia acquisition in back-country travelers to a wilderness area, provide longitudinal follow-up on the incidence of symptomatic gastrointestinal illness and relate such information to concentrations of Giardia cysts in water samples from a high-use area. A prospective cohort non-interventional study of 41 healthy adult backcountry travelers from age 19 to 71 years in Desolation Wilderness, Lake Tahoe Basin was carried out. The incidence of Giardia cyst acquisition in backcountry travelers was only 5.7% (95% CI 0.17–20.2%). Mild, self-limiting gastrointestinal illness occurred in 16.7% of subjects (95% CI 4.9%–34.50%), none of whom demonstrated G. lamblia infection. Water sampling from three popular stream sites revealed cyst contamination to be generally at low levels with cyst concentrations in the single digit range for every 100 gallons filtered. G. lamblia contamination of water occurs, but at low levels. Acquisition of this parasite may be infrequent in backcountry recreationalists. Symptomatic gastrointestinal illness following wilderness travel can be due to other etiologies. Our findings may not be representative of all wilderness areas, but suggest that in the absence of documented G. lamblia infection, persons symptomatic following travel may suffer a self-limiting gastrointestinal illness. In such circumstances, empiric therapy for giardiasis is tempting but difficult to justify.

A real-time RT-PCR method to detect viable Giardia lamblia cysts in environmental waters.

PubMed

Baque, Robert H; Gilliam, Amy O; Robles, Liza D; Jakubowski, Walter; Slifko, Theresa R

2011-05-01

Currently, USEPA Method 1623 is the standard assay used for simultaneous detection of Giardia cysts and Cryptosporidium oocysts in various water matrices. However, the method is unable to distinguish between species, genotype, or to assess viability. Therefore, the objective of the present study was to address the shortcomings of USEPA Method 1623 by developing a novel molecular-based method that can assess viability of Giardia cysts in environmental waters and identify genotypes that pose a human health threat (assemblage groups A and B). Primers and TaqMan(®) probes were designed to target the beta-giardin gene in order to discriminate among species and assemblages. Viability was determined by detection of de-novo mRNA synthesis after heat induction. The beta-giardin primer/probe sets were able to detect and differentiate between Giardia lamblia assemblages A and B, and did not detect Giardia muris (mouse species) or G. lamblia assemblages C, D, E and F (non-human), with the exception of Probe A which did detect G. lamblia assemblage F DNA. Additionally, DNA or cDNA of other waterborne organisms were not detected, suggesting that the method is specific to Giardia assemblages. Assay applicability was demonstrated by detection of viable G. lamblia cysts in spiked (assemblage B) and unspiked (assemblage A and B) reclaimed water samples. Copyright © 2011 Elsevier Ltd. All rights reserved.

Establishment of a C57BL/6N mouse model of giardiasis.

PubMed

Lu, Siqi; Luo, Xiaobing; Chen, Xiaoning; Wang, Fengyun

2002-10-01

To establish a C57BL/6N mouse model infected with Giardia lamblia (G. lamblia) isolates from human origin. Two groups of C57BL/6N mouse were inoculated with purified cysts of two G. lamblia isolates (CD and XZ) by gavage separately. Patterns and curves of cyst excretion of the infected mice were observed and summarized. Histopathological changes of the small intestines of the infected mice were observed. Thirty-six mice receiving 1 x 10(4) cysts each were all infected. The C57BL/6N mouse showed high susceptibility to G. lamblia infection. There was no notable distinction between the two groups of the mice infected by the cysts of CD and XZ isolates. Cyst excretion occurred with intermittence. Of 36 infected mice, 32 (89%) passed cysts intermittently and 4 (11%) others persistently. The latent period of cyst excretion was 0 - 3 days p.i. (post-inoculation). The interruption of cyst excretion ranged from 12 to 20 days p.i. The fastigium of the cyst excretion was on day 6 p.i. The peak count of the cysts passed during a 2 h collection period was 2.3 x 10(7)/g fecal specimen. Edema, inflammation, cell infiltration, small blood vessels congestion, mitotic figures and mucosa necrosis appeared in sections of intestines. C57Bl/6N mouse is a suitable animal model of G. lamblia.

MATRIX ASSISTED LASER DESORPTION/IONIZATION TIME OF FLIGHT MASS SPECTROMETRY BASED ANALYSIS OF GIARDIA LAMBLIA

EPA Science Inventory

Giardia lamblia is a zoonotic protozoan parasite that is a leading cause of drinking water related gastro-intestinal disease outbreaks worldwide. Due to the genotypic complexity and high prevalence of this parasite in the environment, numerous research studies are being done to ...

IDENTIFICATION OF A FLAVOBACTERIUM STRAIN VIRULENT AGAINT GIARDIA LAMBLIA CYSTS

EPA Science Inventory

We have isolated a bacterial strain capable of killing the cyst form of Giardia lamblia, from a Kentucky stream. This bacterium, designated Sun4, is a Gram negative, aerobic rod which produces a yellow pigment, but not of the flexirubin-type. Although true gliding motility has no...

CLONING AND CHARACTERIZATION OF CDNA ENCODING GIARDIA LAMBLIA d-GIARDIN

USDA-ARS?s Scientific Manuscript database

A cDNA coding for d-giardin was cloned from Giardia lamblia trophozoites in order to localize the protein and study its function in mediating surface attachment. Recombinant d-giardin antigen was produced in Escherichia coli as a poly-histidine fusion protein and was purified by affinity chromatogr...

The proteasome of the differently-diverged eukaryote Giardia lamblia and its role in remodeling of the microtubule-based cytoskeleton.

PubMed

Ray, Atrayee; Sarkar, Srimonti

2017-08-01

Giardia lamblia is the causative agent of the diarrheal disease giardiasis, against which only a limited number of drugs are currently available. Increasing reports of resistance to these drugs makes it necessary to identify new cellular targets for designing the next generation of anti-giardial drugs. Towards this goal, therapeutic agents that target the parasitic cellular machinery involved in the functioning of the unique microtubule-based cytoskeleton of the Giardia trophozoites are likely to be effective as microtubule function is not only important for the survival of trophozoites within the host, but also their extensive remodeling is necessary during the transition from trophozoites to cysts. Thus, drugs that affect microtubule remodeling have the potential to not only kill the disease-causing trophozoites, but also inhibit transmission of cysts in the community. Recent studies in other model organisms have indicated that the proteasome plays an integral role in the formation and remodeling of the microtubule-based cytoskeleton. This review draws attention to the various processes by which the giardial proteasome may impact the functioning of its microtubule cytoskeleton and highlights the possible differences of the parasitic proteasome and some of other cellular machinery involved in microtubule remodeling, compared to that of the higher eukaryotic host.

Lectin Activation in Giardia lamblia by Host Protease: A Novel Host-Parasite Interaction

NASA Astrophysics Data System (ADS)

Lev, Boaz; Ward, Honorine; Keusch, Gerald T.; Pereira, Miercio E. A.

1986-04-01

A lectin in Giardia lamblia was activated by secretions from the human duodenum, the environment where the parasite lives. Incubation of the secretions with trypsin inhibitors prevented the appearance of lectin activity, implicating proteases as the activating agent. Accordingly, lectin activation was also produced by crystalline trypsin and Pronase; other proteases tested were ineffective. When activated, the lectin agglutinated intestinal cells to which the parasite adheres in vivo. The lectin was most specific to mannose-6-phosphate and apparently was bound to the plasma membrane. Activation of a parasite lectin by a host protease represents a novel mechanism of hostparasite interaction and may contribute to the affinity of Giardia lamblia to the infection site.

Identification and analysis of the RNA degrading complexes and machinery of Giardia lamblia using an in silico approach

PubMed Central

2011-01-01

Background RNA degradation is critical to the survival of all cells. With increasing evidence for pervasive transcription in cells, RNA degradation has gained recognition as a means of regulating gene expression. Yet, RNA degradation machinery has been studied extensively in only a few eukaryotic organisms, including Saccharomyces cerevisiae and humans. Giardia lamblia is a parasitic protist with unusual genomic traits: it is binucleated and tetraploid, has a very compact genome, displays a theme of genomic minimalism with cellular machinery commonly comprised of a reduced number of protein components, and has a remarkably large population of long, stable, noncoding, antisense RNAs. Results Here we use in silico approaches to investigate the major RNA degradation machinery in Giardia lamblia and compare it to a broad array of other parasitic protists. We have found key constituents of the deadenylation and decapping machinery and of the 5'-3' RNA degradation pathway. We have similarly found that all of the major 3'-5' RNA degradation pathways are present in Giardia, including both exosome-dependent and exosome-independent machinery. However, we observe significant loss of RNA degradation machinery genes that will result in important differences in the protein composition, and potentially functionality, of the various RNA degradation pathways. This is most apparent in the exosome, the central mediator of 3'-5' degradation, which apparently contains an altered core configuration in both Giardia and Plasmodium, with only four, instead of the canonical six, distinct subunits. Additionally the exosome in Giardia is missing both the Rrp6, Nab3, and Nrd1 proteins, known to be key regulators of noncoding transcript stability in other cells. Conclusions These findings suggest that although the full complement of the major RNA degradation mechanisms were present - and likely functional - early in eukaryotic evolution, the composition and function of the complexes is more variable than previously appreciated. We suggest that the missing components of the exosome complex provide an explanation for the stable abundance of sterile RNA species in Giardia. PMID:22126454

Human Memory CD4+ T Cell Immune Responses against Giardia lamblia

PubMed Central

Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina

2015-01-01

The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4+ T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4+ effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4+ EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4+ T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4+ EM T cell response of which IL-17A production seems to be an important component. PMID:26376930

Field portable mobile phone based fluorescence microscopy for detection of Giardia lamblia cysts in water samples

NASA Astrophysics Data System (ADS)

Ceylan Koydemir, Hatice; Gorocs, Zoltan; McLeod, Euan; Tseng, Derek; Ozcan, Aydogan

2015-03-01

Giardia lamblia is a waterborne parasite that causes an intestinal infection, known as giardiasis, and it is found not only in countries with inadequate sanitation and unsafe water but also streams and lakes of developed countries. Simple, sensitive, and rapid detection of this pathogen is important for monitoring of drinking water. Here we present a cost-effective and field portable mobile-phone based fluorescence microscopy platform designed for automated detection of Giardia lamblia cysts in large volume water samples (i.e., 10 ml) to be used in low-resource field settings. This fluorescence microscope is integrated with a disposable water-sampling cassette, which is based on a flow-through porous polycarbonate membrane and provides a wide surface area for fluorescence imaging and enumeration of the captured Giardia cysts on the membrane. Water sample of interest, containing fluorescently labeled Giardia cysts, is introduced into the absorbent pads that are in contact with the membrane in the cassette by capillary action, which eliminates the need for electrically driven flow for sample processing. Our fluorescence microscope weighs ~170 grams in total and has all the components of a regular microscope, capable of detecting individual fluorescently labeled cysts under light-emitting-diode (LED) based excitation. Including all the sample preparation, labeling and imaging steps, the entire measurement takes less than one hour for a sample volume of 10 ml. This mobile phone based compact and cost-effective fluorescent imaging platform together with its machine learning based cyst counting interface is easy to use and can even work in resource limited and field settings for spatio-temporal monitoring of water quality.

Therapeutic enhancement of newly derived bacteriocins against Giardia lamblia.

PubMed

Amer, Eglal I; Mossallam, Shereen F; Mahrous, Hoda

2014-11-01

Trials for identifying efficient anti-giardial agents are still ongoing. Nowadays, bacteriocins have attracted the attention as potential antimicrobial compounds. For the first time, the current study evaluated the therapeutic efficacy of bacteriocins derived from newly isolated Egyptian strains of probiotics Lactobacilli; L. acidophilus (P106) and L. plantarum (P164) against Giardia lamblia. Bacteriocins' efficacy was evaluated both in vitro; by growth inhibition and adherence assays, and in vivo; through estimation of parasite density, intestinal histopathological examination and ultrastructural analysis of Giardia trophozoites. In vivo bacteriocins' clinical safety was assessed. In vitro results proved that 50 µg of L. acidophilus bacteriocin induced reduction of the mean Giardia lamblia trophozoites by 58.3 ± 4.04%, while at lower concentrations of 10 and 20 µg of both L. acidophilus and L. plantarum, non significant reduction of the mean parasite density was achieved. In vitro trophozoites adherence was susceptible to the tested bacteriocins at all studied concentrations with variable degrees, while the highest adherence reduction was demonstrated using 50 µg of L acidophilus bacteriocin. In vivo, oral inoculation of 50 µg/mouse L. acidophilus bacteriocin for 5 successive days resulted in a noteworthy decline of the intestinal parasite density, along with amelioration of intestinal pathology of infected mice. Ultrastructural examination proved thatfive doses of L. acidophilus bacteriocin showed marked changes in cellular architecture of the trophozoites with evident disorganization of the cell membrane, adhesive disc and cytoplasmic components. This is the first reported study of the safe anti-giardial efficacy of L. acidophilus (P106) derived bacteriocin, hence highlighting its great promise as a potential therapeutic safe alternative to existing commercial drugs. Copyright © 2014 Elsevier Inc. All rights reserved.

The Giardia lamblia genome.

PubMed

Adam, R D

2000-04-10

Giardia lamblia is a protozoan parasite of humans and other mammals that is thought to be one of the most primitive extant eukaryotic organisms. Although distinctly eukaryotic, it is notable for its lack of mitochondria, nucleoli, and perixosomes. It has been suggested that Giardia spp. are pre-mitochondriate organisms, but the identification of genes in G. lamblia thought to be of mitochondrial origin has generated controversy regarding that designation. Giardi lamblia trophozoites have two nuclei that are identical in all ways that have been studied. They are polyploid with at least four, and perhaps eight or more, copies of each of five chromosomes per organism and have an estimated genome complexity of 1.2x10(7)bp of DNA, and GC content of 46%. There is evidence for recombination at the telomeres of some of the chromosomes, and multiple size variants of single chromosomes have been identified within cloned isolates. However, the internal regions of the chromosomes demonstrate no evidence of recombination. For example, there is no evidence for control of vsp gene expression by DNA recombination, and no evidence for rapid mutation in the vsp genes. Single pass sequences of approximately 9% of the G. lamblia genome have already been obtained. An ongoing genome project plans to obtain approximately 95% of the genome by a random approach, as well as a complete physical map using a bacterial artificial chromosome library. The results will facilitate a better understanding of the biology of Giardia spp. as well as their phylogenetic relationship to other primitive organisms.

Effects of Dietary Zinc Manipulation on Growth Performance, Zinc Status and Immune Response during Giardia lamblia Infection: A Study in CD-1 Mice

PubMed Central

Iñigo-Figueroa, Gemma; Méndez-Estrada, Rosa O.; Quihui-Cota, Luis; Velásquez-Contreras, Carlos A.; Garibay-Escobar, Adriana; Canett-Romero, Rafael; Astiazarán-García, Humberto

2013-01-01

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 106 G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host’s humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection. PMID:24002196

Prevalence of Cryptosporidium parvum/hominis, Entamoeba histolytica and Giardia lamblia among Young Children with and without Diarrhea in Dar es Salaam, Tanzania.

PubMed

Tellevik, Marit G; Moyo, Sabrina J; Blomberg, Bjørn; Hjøllo, Torunn; Maselle, Samuel Y; Langeland, Nina; Hanevik, Kurt

2015-01-01

Although enteroparasites are common causes of diarrheal illness, few studies have been performed among children in Tanzania. This study aimed to investigate the prevalence of Cryptosporidium parvum/hominis, Entamoeba histolytica and Giardia lamblia among young children in Dar es Salaam, Tanzania, and identify risk factors for infection. We performed an unmatched case-control study among children < 2 years of age in Dar es Salaam, recruited from August 2010 to July 2011. Detection and identification of protozoans were done by PCR techniques on DNA from stool specimens from 701 cases of children admitted due to diarrhea at the three study hospitals, and 558 controls of children with no history of diarrhea during the last month prior to enrollment. The prevalence of C. parvum/hominis was 10.4% (84.7% C. hominis), and that of G. lamblia 4.6%. E. histolytica was not detected. The prevalence of Cryptosporidium was significantly higher in cases (16.3%) than in controls (3.1%; P < 0.001; OR = 6.2; 95% CI: 3.7-10.4). G. lamblia was significantly more prevalent in controls (6.1%) than in cases (3.4%; P = 0.027; OR = 1.8; 95% CI: 1.1-3.1). Cryptosporidium infection was found more often in HIV-positive (24.2%) than in HIV-negative children (3.9%; P < 0.001; OR = 7.9; 95% CI: 3.1-20.5), and was also associated with rainfall (P < 0.001; OR = 2.41; 95% CI: 1.5-3.8). Among cases, stunted children had significantly higher risk of being infected with Cryptosporidium (P = 0.011; OR = 2.12; 95% CI: 1.2-3.8). G. lamblia infection was more prevalent in the cool season (P = 0.004; OR = 2.2; 95% CI: 1.3-3.8), and more frequent among cases aged > 12 months (P = 0.003; OR = 3.5; 95% CI: 1.5-7.8). Among children aged 7-12 months, those who were breastfed had lower prevalence of G. lamblia infection than those who had been weaned (P = 0.012). Cryptosporidium infection is common among young Tanzanian children with diarrhea, particularly those living with HIV, and infection is more frequent during the rainy season. G. lamblia is frequently implicated in asymptomatic infections, but rarely causes overt diarrheal illness, and its prevalence increases with age.

Diagnosis of AIDS-Related Intestinal Parasites

DTIC Science & Technology

1989-01-20

other intestinal parasites: Giardia lamblia (65), Endolimax nana (35), Entamoeba coli (33), Chilomastix mesnili (25), Ascaris lumbricoides (8...likely at risk for infection. ELISA Testing for Entamoeba histolytica, Giardia lamblia, Cryptosporidium 7. Taylor DN, Houston R, Shlim DR, Echeverria P...Assn 260:1245-1248, 1988. Significance: ELISA testing for Entamoeba histolytica antigen in fecal specimens is a viable alternative to traditional

New Disinfection Agents for Water

DTIC Science & Technology

1984-10-01

oo20 7 Effect of Agent I and HTII on Viability of Entamoeba invadens ..... ................ o...type I and rotavirus), protozoa ( Entamoeba invadens and Giardia lamblia), and fungi (Rhodotorula rubra and Candida albicans). Variables in the study...sufficiently long contact time. PROTOZOA STUDIES The IP-1 strain of Entamoeba invadens and the Portland strain of Giardia lamblia were grown in 15 mL

Trends of amino acid usage in the proteins from the unicellular parasite Giardia lamblia.

PubMed

Garat, B; Musto, H

2000-12-29

Correspondence analysis of amino acid frequencies was applied to 75 complete coding sequences from the unicellular parasite Giardia lamblia, and it was found that three major factors influence the variability of amino acidic composition of proteins. The first trend strongly correlated with (a) the cysteine content and (b) the mean weight of the amino acids used in each protein. The second trend correlated with the global levels of hydropathy and aromaticity of each protein. Both axes might be related with the defense of the parasite to oxygen free radicals. Finally, the third trend correlated with the expressivity of each gene, indicating that in G. lamblia highly expressed sequences display a tendency to preferentially use a subset of the total amino acids.

Water quality in three creeks in the backcountry of Grand Teton National Park, USA

USGS Publications Warehouse

Farag, A.M.; Goldstein, J.N.; Woodward, D.F.

2001-01-01

This study was conducted in Grand Teton National Park during the summers of 1996 and 1997 to investigate the water quality in two high human use areas: Garnet Canyon and lower Cascade Canyon. To evaluate the water quality in these creeks, fecal coliform, Giardia lamblia, coccidia, and microparticulates were measured in water samples. No evidence of fecal coliform, Giardia lamblia, or coccidia, was found in Garnet Creek. The water quality and general water chemistry of Garnet Creek was similar to the reference site. No Giardia lamblia or coccidia were found in Cascade Creek, but fecal coliforms were present. The isolated colonies of Escherichia coli from Cascade Creek matched the ribosome patterns of avian, deer, canine, elk, rodent, and human coliforms.

Identification and determination of the viability of Giardia lamblia cysts and Cryptosporidium parvum and Cryptosporidium hominis oocysts in human fecal and water supply samples by fluorescent in situ hybridization (FISH) and monoclonal antibodies.

PubMed

Lemos, Vanessa; Graczyk, Thaddeus K; Alves, Margarida; Lobo, Maria Luísa; Sousa, Maria C; Antunes, Francisco; Matos, Olga

2005-12-01

In the present study, fluorescent in situ hybridization (FISH) and monoclonal antibodies (MAbs) were evaluated for species-specific detection and viability determination of Giardia lamblia, Cryptosporidium parvum, and Cryptosporidium hominis in human fecal and water supply samples. A total of 50 fecal human samples positive for G. lamblia cysts, 38 positive for C. parvum, and 23 positive for C. hominis were studied. Also, 18 water supply samples positive for Giardia spp. and Cryptosporidium spp. by the United States Environmental Protection Agency (USEPA) Method 1623 were studied by FISH and fluorescein isothiocyanate (FITC)-conjugated MAbs. Eighteen percent of the fecal samples parasitologically positive for G. lamblia presented viable and nonviable cysts, and 5% of those positive for Cryptosporidium spp. presented viable and nonviable oocysts. Of the 18 water supply samples analyzed, 6 (33%) presented Giardia spp. viable and nonviable cysts and 2 (11%) presented viable and nonviable Cryptosporidium spp. oocysts. G. lamblia identification was confirmed by polymerase chain reaction (PCR) and sequencing of the beta-giardin gene in the fecal and water samples found positive by FISH and FITC-conjugated MAbs. C. parvum and Cryptosporidium muris were identified, by PCR and sequencing of the small subunit of ribosomal RNA gene, in seven and one water samples, respectively. Our results confirm that this technique enables simultaneous visualization, species-specific identification, and viability determination of the organisms present in human fecal and water supply samples.

Molecular characterization of Giardia lamblia in children less than 5 years of age with diarrhoea attending the Bengo General Hospital, Angola

PubMed Central

Gasparinho, Carolina; Ferreira, Filipa S; Mayer, António Carlos; Mirante, Maria Clara; Vaz Nery, Susana; Santos-Reis, Ana; Portugal-Calisto, Daniela; Brito, Miguel

2017-01-01

Abstract Background Giardia lamblia is a pathogenic intestinal protozoan with high prevalence in developing countries, especially among children. Molecular characterization has revealed the existence of eight assemblages, with A and B being more commonly described in human infections. Despite its importance, to our knowledge this is the first published molecular analysis of G. lamblia assemblages in Angola. Methods The present study aimed to identify the assemblages of G. lamblia in children with acute diarrhoea presenting at the Bengo General Hospital, Angola. A stool sample was collected and microscopy and immunochromatographic tests were used. DNA was extracted and assemblage determination was performed through amplification of the gene fragment ssu-rRNA (175 bp) and β-giardin (511 bp) through polymerase chain reaction and DNA sequencing. Results Of the 16 stool samples screened, 12 were successfully sequenced. Eleven isolates were assigned to assemblage B and one to assemblage A. Subassemblage determination was not possible for assemblage B, while the single isolate assigned to assemblage A was identified as belonging to subassemblage A3. Conclusion This study provides information about G. lamblia assemblages in Bengo Province, Angola and may contribute as a first step in understanding the molecular epidemiology of this protozoan in the country. GenBank accession numbers for the ssur-RNA gene: MF479750, MF479751, MF479752, MF479753, MF479754, MF479755, MF479756, MF479757, MF479758, MF479759, MF479760, MF479761. GenBank accession numbers for the β-giardin gene: MF565378, MF565379, MF565380, MF565381. PMID:29438541

Identification of variant-specific surface proteins in Giardia muris trophozoites.

PubMed

Ropolo, Andrea S; Saura, Alicia; Carranza, Pedro G; Lujan, Hugo D

2005-08-01

Giardia lamblia undergoes antigenic variation, a process that might allow the parasite to evade the host's immune response and adapt to different environments. Here we show that Giardia muris, a related species that naturally infects rodents, possesses multiple variant-specific surface proteins (VSPs) and expresses VSPs on its surface, suggesting that it undergoes antigenic variation similar to that of G. lamblia.

Modified PEHPS medium as an alternative for the in vitro culture of Giardia lamblia.

PubMed

Vargas-Villarreal, Javier; Mata-Cárdenas, Benito D; Hernández-García, Magda E; Garza-González, Jesús N; De La Garza-Salinas, Laura H; González-Salazar, Francisco

2014-01-01

Commercial culture media present interlot variations in biological activity. We have previously designed a homemade and economic culture medium, PEHPS medium, for the axenic cultivation of Entamoeba histolytica and Trichomonas vaginalis. Trophozoites of amoebae and trichomonads grow well in this medium. Furthermore, the medium is stable for several months when stored frozen or refrigerated. The objective of this work was to modify PEHPS medium to support the in vitro growth of Giardia lamblia. Inocula of 5 × 10(3) trophozoites/mL of G. lamblia were incubated at 36.5°C in modified PEHPS or TYI-S-33 medium. Then, the growths of the three Giardia strains in both media were compared. The logarithmic growth phase lasted 72 h; the mean yield of the strains ranged from 10.06 to 11.43 × 10(5) Giardia trophozoites/mL, and the range of duplication time in the three strains was from 5.67 to 6.06 in modified PEHPS medium. These growth characteristics were not significantly different from those obtained with TYI-S-33 medium. We conclude that modified PEHPS medium might be used for the axenic cultivation of G. lamblia.

Antigiardial activity of Ocimum basilicum essential oil.

PubMed

de Almeida, Igor; Alviano, Daniela Sales; Vieira, Danielle Pereira; Alves, Péricles Barreto; Blank, Arie Fitzgerald; Lopes, Angela Hampshire C S; Alviano, Celuta Sales; Rosa, Maria do Socorro S

2007-07-01

In this study, we investigated the effects of Ocimum basilicum essential oil on Giardia lamblia and on the modulation of the interaction of these parasites by peritoneal mouse macrophage. The essential oil (2 mg/ml) and its purified substances demonstrated antigiardial activity. Linalool (300 microg/ml), however, was able to kill 100% parasites after 1 h of incubation, which demonstrates its high antigiardial potential. Pretreatment of peritoneal mouse macrophages with 2 mg/ml essential oil dilution reduced in 79% the association index between these macrophages and G. lamblia, with a concomitant increase by 153% on nitric oxide production by the G. lamblia-ingested macrophages. The protein profiles and proteolitic activity of these parasite trophozoites, previously treated or not with 2 mg/ml essential oil or with the purified fractions, were also determined. After 1 and 2 h of incubation, proteins of lysates and culture supernatants revealed significant differences in bands patterns when compared to controls. Besides, the proteolitic activity, mainly of cysteine proteases, was clearly inhibited by the essential oil (2 mg/ml) and the purified linalool (300 microg/ml). These results suggest that, with G. lamblia, the essential oil from O. basilicum and its purified compounds, specially linalool, have a potent antimicrobial activity.

Prevalence of Giardia lamblia in Different Water Sources of District Nowshehra, Khyber Pakhtunkhwa Pakistan.

NASA Astrophysics Data System (ADS)

khan, Shaukat Ali; Ayaz, Sultan; Khan, Sanaullah; Anees, Muhammad; Khan, Amir Muhammad; Khan, Imran

2012-12-01

Giardia lamblia is a cosmopolitan parasite that occurs worldwide and generally effects gastrointestinal tract. Water played a media for transmission of Giardia to different hosts. A total of 300 water samples were examined from different water sources, i.e. tap, open well, bore well and drain waters and DNA was extracted by trizol method through prescribed protocol. DNA was amplified through PCR. The overall prevalence of G. lamblia was 27.66% (83/300). Among these 2.5% (1/40) in bore well water, 29% (29/100) open well, 18.83% (11/60) tap water and 42% (42/100) drain water. It is concluded from the study that Giardia is frequently found in all water sources and is the main cause of ill health.

Antiparasitic activity of diallyl trisulfide (Dasuansu) on human and animal pathogenic protozoa (Trypanosoma sp., Entamoeba histolytica and Giardia lamblia) in vitro.

PubMed

Lun, Z R; Burri, C; Menzinger, M; Kaminsky, R

1994-03-01

Garlic (Allium sativum L.) and one of its major components, allicin, have been known to have antibacterial and antifungal activity for a long time. Diallyl trisulfide is a chemically stable final transformation product of allicin which was synthesized in 1981 in China and used for treatment of bacterial, fungal and parasitic infections in man. The activity of diallyl trisulfide was investigated in several important protozoan parasites in vitro. The IC50 (concentration which inhibits metabolism or growth of parasites by 50%) for Trypanosoma brucei brucei, T.b. rhodesiense, T.b. gambiense, T. evansi, T. congolense and T. equiperdum was in the range of 0.8-5.5 micrograms/ml. IC50 values were 59 micrograms/ml for Entamoeba histolytica and 14 micrograms/ml for Giardia lamblia. The cytotoxicity of the compound was evaluated on two fibroblast cell lines (MASEF, Mastomys natalensis embryo fibroblast and HEFL-12, human embryo fibroblast) in vitro. The maximum tolerated concentration for both cell lines was 25 micrograms/ml. The results indicate that the compound has potential to be used for treatment of several human and animal parasitic diseases.

[Detection of antibodies against Lamblia antigens in serum from atopic patients].

PubMed

Akhapkina, I G

2004-04-01

The method of solid-phase immune-enzyme assay was used to test the sera of atopic patients for the purpose of detecting IgG to lamblias. A high degree of protozoal invasion was established especially among pre-school and school children. It was proven as expedient to make the serological examinations of atopic patients in cases the clinical finding is unclear.

Identification of Variant-Specific Surface Proteins in Giardia muris Trophozoites

PubMed Central

Ropolo, Andrea S.; Saura, Alicia; Carranza, Pedro G.; Lujan, Hugo D.

2005-01-01

Giardia lamblia undergoes antigenic variation, a process that might allow the parasite to evade the host's immune response and adapt to different environments. Here we show that Giardia muris, a related species that naturally infects rodents, possesses multiple variant-specific surface proteins (VSPs) and expresses VSPs on its surface, suggesting that it undergoes antigenic variation similar to that of G. lamblia. PMID:16041041

Prevalence of Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. in Libya: 2000-2015.

PubMed

Ghenghesh, Khalifa Sifaw; Ghanghish, Khaled; BenDarif, Elloulu T; Shembesh, Khaled; Franka, Ezzadin

2016-01-01

The intestinal protozoa Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. are the causative agents of giardiasis, amebiasis, and cryptosporidiosis, respectively. Adequate knowledge of the geographical distribution of parasites and the demographic variables that influence their prevalence is important for effective control of infection in at-risk populations. The data were obtained by an English language literature search of Medline and PubMed for papers using the search terms 'intestinal parasites and Libya, G. lamblia and Libya, E. histolytica and Libya and Cryptosporidium and Libya' for the period 2000-2015. The data obtained for the period 2000-2015 showed prevalence rates of 0.8-36.6% (mean 19.9%) for E. histolytica/dispar, 1.2-18.2% (mean 4.6%) for G. lamblia and 0.9-13% (mean 3.4%) for Cryptosporidium spp. among individuals in Libya with gastroenteritis (GE). On the other hand, prevalence rates of 0.8-16.3% (mean 8.3%), 1.8-28.8% (mean 4.8%), and 1.0-2.5% (mean=2.4), respectively, were observed for individuals without GE. The mean prevalence rate of E. histolytica/dispar was significantly higher among individuals with GE compared with those without GE (p<0.0000001, OR=2.74). No significant difference in prevalence rate of the three organisms was found according to gender, but most of infections were observed in children aged 10 years or younger. The reviewed data suggest that E. histolytica, G. lamblia, and Cryptosporidium spp. may play a minor role in GE in Libya. The observed high prevalence rates of E. histolytica/dispar reported from Libya could be due mainly to the non-pathogenic E. dispar and E. moshkovskii. However, more studies are needed in the future using E. histolytica-specific enzyme immunoassays and/or molecular methods to confirm this observation.

Antigenic switching of TSA 417, a trophozoite variable surface protein, following completion of the life cycle of Giardia lamblia.

PubMed Central

Meng, T C; Hetsko, M L; Gillin, F D

1993-01-01

Expression of TSA 417, the predominant cysteine-rich variable surface protein of Giardia lamblia WB clone C6 trophozoites, did not change during encystation in vitro. However, in vitro excystation of cysts derived in vitro or in vivo consistently produced TSA 417 nonexpressing trophozoite populations, suggesting that completion of the life cycle leads to antigenic switching. Images PMID:8225614

Larrea tridentata: A novel source for anti-parasitic agents active against Entamoeba histolytica, Giardia lamblia and Naegleria fowleri.

PubMed

Bashyal, Bharat; Li, Linfeng; Bains, Trpta; Debnath, Anjan; LaBarbera, Daniel V

2017-08-01

Protozoan parasites infect and kill millions of people worldwide every year, particularly in developing countries where access to clean fresh water is limited. Among the most common are intestinal parasites, including Giardia lamblia and Entamoeba histolytica. These parasites wreak havoc on the epithelium lining the small intestines (G. lamblia) and colon (E. histolytica) causing giardiasis and amebiasis, respectively. In addition, there are less common but far more deadly pathogens such as Naegleria fowleri that thrive in warm waters and infect the central nervous systems of their victims via the nasal passages. Despite their prevalence and associated high mortality rates, there remains an unmet need to identify more effective therapeutics for people infected with these opportunistic parasites. To address this unmet need, we have surveyed plants and traditional herbal medicines known throughout the world to identify novel antiparasitic agents with activity against G. lamblia, E. histolytica, and N. fowleri. Herein, we report Larrea tridentata, known as creosote bush, as a novel source for secondary metabolites that display antiparasitic activity against all three pathogens. This report also characterizes the lignan compound classes, nordihydroguairetic acid and demethoxyisoguaiacin, as novel antiparasitic lead agents to further develop more effective drug therapy options for millions of people worldwide.

Larrea tridentata: A novel source for anti-parasitic agents active against Entamoeba histolytica, Giardia lamblia and Naegleria fowleri

PubMed Central

Bains, Trpta; Debnath, Anjan

2017-01-01

Protozoan parasites infect and kill millions of people worldwide every year, particularly in developing countries where access to clean fresh water is limited. Among the most common are intestinal parasites, including Giardia lamblia and Entamoeba histolytica. These parasites wreak havoc on the epithelium lining the small intestines (G. lamblia) and colon (E. histolytica) causing giardiasis and amebiasis, respectively. In addition, there are less common but far more deadly pathogens such as Naegleria fowleri that thrive in warm waters and infect the central nervous systems of their victims via the nasal passages. Despite their prevalence and associated high mortality rates, there remains an unmet need to identify more effective therapeutics for people infected with these opportunistic parasites. To address this unmet need, we have surveyed plants and traditional herbal medicines known throughout the world to identify novel antiparasitic agents with activity against G. lamblia, E. histolytica, and N. fowleri. Herein, we report Larrea tridentata, known as creosote bush, as a novel source for secondary metabolites that display antiparasitic activity against all three pathogens. This report also characterizes the lignan compound classes, nordihydroguairetic acid and demethoxyisoguaiacin, as novel antiparasitic lead agents to further develop more effective drug therapy options for millions of people worldwide. PMID:28793307

Detection and genotyping of Entamoeba histolytica, Entamoeba dispar, Giardia lamblia, and Cryptosporidium parvum by oligonucleotide microarray.

PubMed

Wang, Zheng; Vora, Gary J; Stenger, David A

2004-07-01

Entamoeba histolytica, Giardia lamblia, and Cryptosporidium parvum are the most frequently identified protozoan parasites causing waterborne disease outbreaks. The morbidity and mortality associated with these intestinal parasitic infections warrant the development of rapid and accurate detection and genotyping methods to aid public health efforts aimed at preventing and controlling outbreaks. In this study, we describe the development of an oligonucleotide microarray capable of detecting and discriminating between E. histolytica, Entamoeba dispar, G. lamblia assemblages A and B, and C. parvum types 1 and 2 in a single assay. Unique hybridization patterns for each selected protozoan were generated by amplifying six to eight diagnostic sequences/organism by multiplex PCR; fluorescent labeling of the amplicons via primer extension; and subsequent hybridization to a set of genus-, species-, and subtype-specific covalently immobilized oligonucleotide probes. The profile-based specificity of this methodology not only permitted for the unequivocal identification of the six targeted species and subtypes, but also demonstrated its potential in identifying related species such as Cryptosporidium meleagridis and Cryptosporidium muris. In addition, sensitivity assays demonstrated lower detection limits of five trophozoites of G. lamblia. Taken together, the specificity and sensitivity of the microarray-based approach suggest that this methodology may provide a promising tool to detect and genotype protozoa from clinical and environmental samples.

Does the use of tubular digesters to treat livestock waste lower the risk of infection from Cryptosporidium parvum and Giardia lamblia?

PubMed

Kinyua, Maureen N; Wald, Ileana; Camacho-Céspedes, Fabricio; Izurieta, Ricardo; Haas, Charles N; Ergas, Sarina J

2016-10-01

Worldwide, high incidences of cryptosporidiosis and giardiasis are attributed to livestock waste. Quantitative microbial risk assessment can be used to estimate the risk of livestock related infections from Cryptosporidium parvum and Giardia lamblia. The objective of this paper was to assess the occupational and public health risks associated with management of raw and anaerobically digested livestock waste in two rural communities in Costa Rica based on fomite, soil and crop contamination and livestock waste management exposure pathways. Risks related to cattle waste were greater than swine waste due to cattle shedding more (oo)cysts. Cryptosporidium parvum also posed a greater risk than Giardia lamblia in all exposure pathways due to livestock shedding high loads of Cryptosporidium parvum oocysts and oocysts' lower inactivation rates during anaerobic digestion compared with Giardia lamblia cysts. The risk of infection from exposure to contaminated soil and crops was significantly lower for a community using tubular anaerobic digesters to treat livestock waste compared to a community where the untreated waste was applied to soil. The results indicate that treatment of livestock waste in small-scale tubular anaerobic digesters has the potential to significantly decrease the risk of infection below the World Health Organization's acceptable individual annual risk of infection (10 -4 ).

Ultrastructural observations on giardiasis in a mouse model. II. Endosymbiosis and organelle distribution in Giardia muris and Giardia lamblia.

PubMed

Nemanic, P C; Owen, R L; Stevens, D P; Mueller, J C

1979-08-01

Ultrastructural observations of Giardia muris in a mouse model revealed endosymbiotic microbes not previously reported in Giardia. Endosymbionts 240--360 nm wide, 600--1,400 nm long, and with an internal structure similar to that of bacilli were not seen entering Giardia but were found and appeared to divide within Giardia. No evidence was found of digestion of the endosymbionts by the giardia host in either the trophozoite or the cyst form. Endosymbionts were concentrated centrally around the nuclear area and were uncommon in peripheral feeding regions. The same cellular organelles seen in G. muris were found in Giardia lamblia from human jejunal biopsy material, but no endosymbionts were identified in G. lamblia trophozoites from the seven patients examined. Endosymbionts within Giardia may be found to alter trophozoite pathogenicity, metabolism, range of infectivity, antigenic surface characteristics, and host specificity, as they do in other protozoa.

Monitoring of Noxious Protozoa for Management of Natural Water Resources.

PubMed

Bahk, Young Yil; Cho, Pyo Yun; Ahn, Sung Kyu; Park, Sangjung; Jheong, Won Hwa; Park, Yun-Kyu; Shin, Ho-Joon; Lee, Sang-Seob; Rhee, Okjae; Kim, Tong-Soo

2018-04-01

Waterborne parasitic protozoa, particularly Giardia lamblia and Cryptosporidium spp., are common causes of diarrhea and gastroenteritis worldwide. The most frequently identified source of infestation is water, and exposure involves either drinking water or recreation in swimming pools or natural bodies of water. In practice, studies on Cryptosporidium oocysts and Giardia cysts in surface water are challenging owing to the low concentrations of these microorganisms because of dilution. In this study, a 3-year monitoring of Cryptosporidium parvum, Giardia lamblia , and Naegleria fowleri was conducted from August 2014 to June 2016 at 5 surface water sites including 2 lakes, 1 river, and 2 water intake plants. A total of 50 water samples of 40 L were examined. Cryptosporidium oocysts were detected in 22% of samples and Giardia cysts in 32%. Water at the 5 sampling sites was all contaminated with Cryptosporidium oocysts (0-36/L), Giardia cysts (0-39/L), or both. The geometric mean concentrations of Cryptosporidium and Giardia were 1.14 oocysts/L and 4.62 cysts/L, respectively. Thus, effective monitoring plans must take into account the spatial and temporal parameters of contamination because they affect the prevalence and distribution of these protozoan cysts in local water resources.

Filtration of Pathogenic Parasites Using Surfactant-Modified Zeolites

NASA Astrophysics Data System (ADS)

Lehner, T.; Schulze-Makuch, D.; Bowman, R.

2003-12-01

Migration of pathogenic microorganisms, specifically Cryptosporidium parvum and Giardia lamblia, in groundwater due to sewage effluent and mismanaged wastewater has become an increased concern for human health in many regions. Cryptosporididosis and Giardiasis produces moderate to severe intestinal illness for many weeks and is a serious threat for immunodeficient persons. Previous studies by Schulze-Makuch et al. (2002) indicated that surfactant-modified zeolites (SMZ) removed all of the bacteria and most viruses in laboratory experiments. This study focuses on the efficiency of the SMZ to prevent migration of the protozoan spores in groundwater. Adsorption of the spores involves interactions between the surface properties of the spores and the SMZ. The efficiency of removal is tested simulating natural conditions. Laboratory experiments are conducted in a plexiglass model aquifer and pathogen removal is measured by taking water samples from strategically placed piezometers in the model. Since C. parvum and G. lamblia are hazardous to humans and move primarily in spore state through groundwater, polystyrene microspheres of similar sizes and Bacillus subtilis, a sporulating bacterium, are used as analogues for the protozoa. Preliminary results show a significant decrease in concentration of the B. subtilis spores down-gradient of the barrier.

Fecal indicators and zoonotic pathogens in household drinking water taps fed from rainwater tanks in Southeast Queensland, Australia.

PubMed

Ahmed, W; Hodgers, L; Sidhu, J P S; Toze, S

2012-01-01

In this study, the microbiological quality of household tap water samples fed from rainwater tanks was assessed by monitoring the numbers of Escherichia coli bacteria and enterococci from 24 households in Southeast Queensland (SEQ), Australia. Quantitative PCR (qPCR) was also used for the quantitative detection of zoonotic pathogens in water samples from rainwater tanks and connected household taps. The numbers of zoonotic pathogens were also estimated in fecal samples from possums and various species of birds by using qPCR, as possums and birds are considered to be the potential sources of fecal contamination in roof-harvested rainwater (RHRW). Among the 24 households, 63% of rainwater tank and 58% of connected household tap water (CHTW) samples contained E. coli and exceeded Australian drinking water guidelines of <1 CFU E. coli per 100 ml water. Similarly, 92% of rainwater tanks and 83% of CHTW samples also contained enterococci. In all, 21%, 4%, and 13% of rainwater tank samples contained Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% of rainwater tank and 13% of CHTW samples contained Campylobacter spp. and G. lamblia, respectively. The number of E. coli (P = 0.78), Enterococcus (P = 0.64), Campylobacter (P = 0.44), and G. lamblia (P = 0.50) cells in rainwater tanks did not differ significantly from the numbers observed in the CHTW samples. Among the 40 possum fecal samples tested, Campylobacter spp., Cryptosporidium parvum, and G. lamblia were detected in 60%, 13%, and 30% of samples, respectively. Among the 38 bird fecal samples tested, Campylobacter spp., Salmonella spp., C. parvum, and G. lamblia were detected in 24%, 11%, 5%, and 13% of the samples, respectively. Household tap water samples fed from rainwater tanks tested in the study appeared to be highly variable. Regular cleaning of roofs and gutters, along with pruning of overhanging tree branches, might also prove effective in reducing animal fecal contamination of rainwater tanks.

Evaluation of nine immunoassay kits (enzyme immunoassay and direct fluorescence) for detection of Giardia lamblia and Cryptosporidium parvum in human fecal specimens.

PubMed Central

Garcia, L S; Shimizu, R Y

1997-01-01

It is well known that Giardia lamblia and Cryptosporidium parvum can cause severe symptoms in humans, particularly those who are immunologically compromised. Immunoassay procedures offer both increased sensitivity and specificity compared to conventional staining methods. These reagents are also helpful when screening large numbers of patients, particularly in an outbreak situation or when screening patients with minimal symptoms. The data obtained by using 9 diagnostic kits were compared: direct fluorescent-antibody assay (DFA) kits (TechLab Giardia/Crypto IF kit, TechLab Crypto IF kit, and Meridian Merifluor Cryptosporidium/Giardia) and enzyme immunoassay (EIA) kits (Alexon ProSpecT Giardia EZ Microplate Assay, Alexon ProSpecT Cryptosporidium Microplate Assay, Cambridge Giardia lamblia Antigen Microwell ELISA, Meridian Premier Giardia lamblia, Meridian Premier Cryptosporidium, TechLab Giardia CELISA, Trend Giardia lamblia EIA). The test with the Meridian Merifluor Cryptosporidium/Giardia kit was used as the reference method. In various combinations, 60 specimens positive for Giardia, 60 specimens positive for Cryptosporidium, 40 specimens positive for a Giardia-Cryptosporidium mix, and 50 negative fecal specimens were tested. Different species (nine protozoa, three coccidia, one microsporidium, five nematodes, three cestodes, and one trematode) were included in the negative specimens. The sensitivity of EIA for Giardia ranged from 94% (Alexon) to 99% (Trend and Cambridge); the specificity was 100% with all EIA kits tested. The sensitivity of EIA for Cryptosporidium ranged from 98% (Alexon) to 99% (Meridian Premier); specificities were 100%. All DFA results were in agreement, with 100% sensitivity and specificity; however, the TechLab reagents resulted in fluorescence intensity that was generally one level below that seen with the reagents used in the reference method. In addition to sensitivity and specificity, factors such as cost, simplicity, ease of interpretation of results (color, intensity of fluorescence), equipment, available personnel, and number of tests ordered are also important considerations prior to kit selection. PMID:9163474

Prevalence of Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. in Libya: 2000-2015.

PubMed

Ghenghesh, Khalifa Sifaw; Ghanghish, Khaled; BenDarif, Elloulu T; Shembesh, Khaled; Franka, Ezzadin

2016-01-01

Introduction The intestinal protozoa Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. are the causative agents of giardiasis, amebiasis, and cryptosporidiosis, respectively. Adequate knowledge of the geographical distribution of parasites and the demographic variables that influence their prevalence is important for effective control of infection in at-risk populations. Methods The data were obtained by an English language literature search of Medline and PubMed for papers using the search terms 'intestinal parasites and Libya, G. lamblia and Libya, E. histolytica and Libya and Cryptosporidium and Libya' for the period 2000-2015. Results The data obtained for the period 2000-2015 showed prevalence rates of 0.8-36.6% (mean 19.9%) for E. histolytica/dispar, 1.2-18.2% (mean 4.6%) for G. lamblia and 0.9-13% (mean 3.4%) for Cryptosporidium spp. among individuals in Libya with gastroenteritis (GE). On the other hand, prevalence rates of 0.8-16.3% (mean 8.3%), 1.8-28.8% (mean 4.8%), and 1.0-2.5% (mean=2.4), respectively, were observed for individuals without GE. The mean prevalence rate of E. histolytica/dispar was significantly higher among individuals with GE compared with those without GE (p<0.0000001, OR=2.74). No significant difference in prevalence rate of the three organisms was found according to gender, but most of infections were observed in children aged 10 years or younger. Conclusion The reviewed data suggest that E. histolytica, G. lamblia, and Cryptosporidium spp. may play a minor role in GE in Libya. The observed high prevalence rates of E. histolytica/dispar reported from Libya could be due mainly to the non-pathogenic E. dispar and E. moshkovskii. However, more studies are needed in the future using E. histolytica-specific enzyme immunoassays and/or molecular methods to confirm this observation.

Prevalence of Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. in Libya: 2000–2015

PubMed Central

Ghenghesh, Khalifa Sifaw; Ghanghish, Khaled; BenDarif, Elloulu T.; Shembesh, Khaled; Franka, Ezzadin

2016-01-01

Introduction The intestinal protozoa Entamoeba histolytica, Giardia lamblia, and Cryptosporidium spp. are the causative agents of giardiasis, amebiasis, and cryptosporidiosis, respectively. Adequate knowledge of the geographical distribution of parasites and the demographic variables that influence their prevalence is important for effective control of infection in at-risk populations. Methods The data were obtained by an English language literature search of Medline and PubMed for papers using the search terms ‘intestinal parasites and Libya, G. lamblia and Libya, E. histolytica and Libya and Cryptosporidium and Libya’ for the period 2000–2015. Results The data obtained for the period 2000–2015 showed prevalence rates of 0.8–36.6% (mean 19.9%) for E. histolytica/dispar, 1.2–18.2% (mean 4.6%) for G. lamblia and 0.9–13% (mean 3.4%) for Cryptosporidium spp. among individuals in Libya with gastroenteritis (GE). On the other hand, prevalence rates of 0.8–16.3% (mean 8.3%), 1.8–28.8% (mean 4.8%), and 1.0–2.5% (mean=2.4), respectively, were observed for individuals without GE. The mean prevalence rate of E. histolytica/dispar was significantly higher among individuals with GE compared with those without GE (p<0.0000001, OR=2.74). No significant difference in prevalence rate of the three organisms was found according to gender, but most of infections were observed in children aged 10 years or younger. Conclusion The reviewed data suggest that E. histolytica, G. lamblia, and Cryptosporidium spp. may play a minor role in GE in Libya. The observed high prevalence rates of E. histolytica/dispar reported from Libya could be due mainly to the non-pathogenic E. dispar and E. moshkovskii. However, more studies are needed in the future using E. histolytica-specific enzyme immunoassays and/or molecular methods to confirm this observation. PMID:27363524

GIS-based analysis of the fate of waste-related pathogens Cryptosporidium parvum, Giardia lamblia and Escherichia coli in a tropical canal network.

PubMed

Diallo, Mamadou B C; Anceno, Alfredo J; Tawatsupa, Benjawan; Tripathi, Nitin K; Wangsuphachart, Voranuch; Shipin, Oleg V

2009-03-01

Urban canals play a major socio-economic role in many tropical countries and, particularly, Thailand. One of the overlooked functions that they perform is a significant attenuation of waste-related pathogens posing considerable health risk, as well as pollution attenuation in general. The study dealt with a comparison of three canals receiving: (i) municipal, (ii) mainly industrial and (iii) mainly agricultural wastewater, listed in order of progressively decreasing organic loading. The occurrence and fate of waterborne Cryptosporidium parvum, Giardia lamblia and Escherichia coli were monitored in the canals by both real-time PCR and conventionally for 12 months. The pathogens are etiological agents of an estimated 38% and 47% of diarrhea cases worldwide and in Thailand, respectively. The geographic information system (GIS) was used to evaluate and map point and, particularly, non-point pollution sources which allowed differentiating the canal sections in terms of predominant pathogen sources. The flowthrough canals, which can be viewed as waste stabilization ponds, were found to be efficiently removing the pathogens at the following generalized specific rates: 0.3 (C. parvum), 1.2 (G. lamblia), 1.8 (E. coli) log10/km.d in the dry season. The rates decreased in the rainy season for E. coli and G. lamblia, but increased for C. parvum which indicated different removal mechanisms. Data suggest that E. coli and G. lamblia were mainly removed through sedimentation and sunlight (UV) irradiation, while the likely mechanism for C. parvum was predation. Overall, the specific pathogen removal rates positively correlated with the canal organic loading rates in the rainy season. As an important result, an estimate of the municipal pollution mitigation by over 2280 km canals in the Greater Bangkok suggests that concomitant to the pathogens at least 36-95 tons of BOD5 is being removed daily, thereby saving the receiving Chao Phraya River and Bight of Bangkok, by far exceeding current, from major eutrophication problems.

Fecal Indicators and Zoonotic Pathogens in Household Drinking Water Taps Fed from Rainwater Tanks in Southeast Queensland, Australia

PubMed Central

Hodgers, L.; Sidhu, J. P. S.; Toze, S.

2012-01-01

In this study, the microbiological quality of household tap water samples fed from rainwater tanks was assessed by monitoring the numbers of Escherichia coli bacteria and enterococci from 24 households in Southeast Queensland (SEQ), Australia. Quantitative PCR (qPCR) was also used for the quantitative detection of zoonotic pathogens in water samples from rainwater tanks and connected household taps. The numbers of zoonotic pathogens were also estimated in fecal samples from possums and various species of birds by using qPCR, as possums and birds are considered to be the potential sources of fecal contamination in roof-harvested rainwater (RHRW). Among the 24 households, 63% of rainwater tank and 58% of connected household tap water (CHTW) samples contained E. coli and exceeded Australian drinking water guidelines of <1 CFU E. coli per 100 ml water. Similarly, 92% of rainwater tanks and 83% of CHTW samples also contained enterococci. In all, 21%, 4%, and 13% of rainwater tank samples contained Campylobacter spp., Salmonella spp., and Giardia lamblia, respectively. Similarly, 21% of rainwater tank and 13% of CHTW samples contained Campylobacter spp. and G. lamblia, respectively. The number of E. coli (P = 0.78), Enterococcus (P = 0.64), Campylobacter (P = 0.44), and G. lamblia (P = 0.50) cells in rainwater tanks did not differ significantly from the numbers observed in the CHTW samples. Among the 40 possum fecal samples tested, Campylobacter spp., Cryptosporidium parvum, and G. lamblia were detected in 60%, 13%, and 30% of samples, respectively. Among the 38 bird fecal samples tested, Campylobacter spp., Salmonella spp., C. parvum, and G. lamblia were detected in 24%, 11%, 5%, and 13% of the samples, respectively. Household tap water samples fed from rainwater tanks tested in the study appeared to be highly variable. Regular cleaning of roofs and gutters, along with pruning of overhanging tree branches, might also prove effective in reducing animal fecal contamination of rainwater tanks. PMID:22020514

Different profile of intestinal protozoa and helminthic infections among patients with diarrhoea according to age attending a rural hospital in southern Ethiopia.

PubMed

Ramos, Jose M; Rodríguez-Valero, Natalia; Tisiano, Gabriel; Fano, Haji; Yohannes, Tafese; Gosa, Ashenafi; Fruttero, Enza; Reyes, Francisco; Górgolas, Miguel

2014-06-01

The aim of this study was to analyze the association of intestinal parasitic diseases with age and gender in patients with diarrhea attending a rural hospital in southern Ethiopia in the period 2007-2012. A total of 32,191 stool examination was performed in patients who presented with diarrhea. The overall prevalence of intestinal parasites in the present study was 26.5%. Predominant parasites detected were Giardia lamblia (15.0%), Entamoeba histolytica/dispar (5.4%), and Ascaris lumbricoides (5.0%). The median of age of diarrheal patients with Hymenolepis species, Schistosoma mansoni and G. lamblia was significantly lower (5 y., 10.5 y., and 18 y., respectively; p<0.001). The median age of diarrheal patients with Taenia species, S. stercoralis, and E. histolytica/dispar was significantly higher (24 y., 24 y., and 20 y., respectively; p<0.01). In conclusion, Giardia lamblia was the most prevalent intestinal parasite and the profile of intestinal parasitic infections is influenced by age.

Genotyping of Giardia lamblia isolates from humans in China and Korea using ribosomal DNA Sequences.

PubMed

Yong, T S; Park, S J; Hwang, U W; Yang, H W; Lee, K W; Min, D Y; Rim, H J; Wang, Y; Zheng, F

2000-08-01

Genetic characterization of a total of 15 Giardia lamblia isolates, 8 from Anhui Province, China (all from purified cysts) and 7 from Seoul, Korea (2 from axenic cultures and 5 from purified cysts), was performed by polymerase chain reaction amplification and sequencing of a 295-bp region near the 5' end of the small subunit ribosomal DNA (eukaryotic 16S rDNA). Phylogenetic analyses were subsequently conducted using sequence data obtained in this study, as well as sequences published from other Giardia isolates. The maximum parsimony method revealed that G. lamblia isolates from humans in China and Korea are divided into 2 major lineages, assemblages A and B. All 7 Korean isolates were grouped into assemblage A, whereas 4 Chinese isolates were grouped into assemblage A and 4 into assemblage B. Two Giardia microti isolates and 2 dog-derived Giardia isolates also grouped into assemblage B, whereas Giardia ardeae and Giardia muris were unique.

The effect of UV light on the inactivation of Giardia lamblia and Giardia muris cysts as determined by animal infectivity assay (P-2951-01).

PubMed

Mofidi, Alexander A; Meyer, Ernest A; Wallis, Peter M; Chou, Connie I; Meyer, Barbara P; Ramalingam, Shivaji; Coffey, Bradley M

2002-04-01

This study measured the effect of germicidal ultraviolet (UV) light on Giardia lamblia and Giardia muris cysts, as determined by their infectivity in Mongolian gerbils and CD-1 mice, respectively. Reduction of cyst infectivity due to UV exposure was quantified by applying most probable number techniques. Controlled bench-scale, collimated-beam tests exposed cysts suspended in filtered natural water to light from a low-pressure UV lamp. Both G. lamblia and G. muris cysts showed similar sensitivity to UV light. At 3 mJ/cm2, a dose 10-fold lower than what large-scale UV reactors may be designed to provide, > 2-log10 (99 percent) inactivation was observed. These results, combined with previously published data showing other protozoa and bacteria have similar, high sensitivity to UV light, establish that UV disinfection of drinking water is controlled by viruses which may require over 10-fold more UV dose for the same level of control.

Automated 3D detection and classification of Giardia lamblia cysts using digital holographic microscopy with partially coherent source

NASA Astrophysics Data System (ADS)

El Mallahi, A.; Detavernier, A.; Yourassowsky, C.; Dubois, F.

2012-06-01

Over the past century, monitoring of Giardia lamblia became a matter of concern for all drinking water suppliers worldwide. Indeed, this parasitic flagellated protozoan is responsible for giardiasis, a widespread diarrhoeal disease (200 million symptomatic individuals) that can lead immunocompromised individuals to death. The major difficulty raised by Giardia lamblia's cyst, its vegetative transmission form, is its ability to survive for long periods in harsh environments, including the chlorine concentrations and treatment duration used traditionally in water disinfection. Currently, there is a need for a reliable, inexpensive, and easy-to-use sensor for the identification and quantification of cysts in the incoming water. For this purpose, we investigated the use of a digital holographic microscope working with partially coherent spatial illumination that reduces the coherent noise. Digital holography allows one to numerically investigate a volume by refocusing the different plane of depth of a hologram. In this paper, we perform an automated 3D analysis that computes the complex amplitude of each hologram, detects all the particles present in the whole volume given by one hologram and refocuses them if there are out of focus using a refocusing criterion based on the integrated complex amplitude modulus and we obtain the (x,y,z) coordinates of each particle. Then the segmentation of the particles is processed and a set of morphological and textures features characteristic to Giardia lamblia cysts is computed in order to classify each particles in the right classes.

Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process

PubMed Central

Merino, María C.; Zamponi, Nahuel; Vranych, Cecilia V.; Touz, María C.; Rópolo, Andrea S.

2014-01-01

Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation. PMID:25058047

Curcumin alters the cytoskeleton and microtubule organization on trophozoites of Giardia lamblia.

PubMed

Gutiérrez-Gutiérrez, Filiberto; Palomo-Ligas, Lissethe; Hernández-Hernández, José Manuel; Pérez-Rangel, Armando; Aguayo-Ortiz, Rodrigo; Hernández-Campos, Alicia; Castillo, Rafael; González-Pozos, Sirenia; Cortés-Zárate, Rafael; Ramírez-Herrera, Mario Alberto; Mendoza-Magaña, María Luisa; Castillo-Romero, Araceli

2017-08-01

Giardia lamblia is a worldwide protozoan responsible for a significant number of intestinal infections. There are several drugs for the treatment of giardiasis, but they often cause side effects. Curcumin, a component of turmeric, has antigiardial activity; however, the molecular target and mechanism of antiproliferative activity are not clear. The effects of curcumin on cellular microtubules have been widely investigated. Since tubulin is the most abundant protein in the cytoskeleton of Giardia, to elucidate whether curcumin has activity against the microtubules of this parasite, we treated trophozoites with curcumin and the cells were analyzed by scanning electron microscopy and confocal microscopy. Curcumin inhibited Giardia proliferation and adhesion in a time-concentration-dependent mode. The higher inhibitory concentrations of curcumin (3 and 15μM) disrupted the cytoskeletal structures of trophozoites; the damage was evident on the ventral disk, flagella and in the caudal region, also the membrane was affected. The immunofluorescence images showed altered distribution of tubulin staining on ventral disk and flagella. Additionally, we found that curcumin caused a clear reduction of tubulin expression. By docking analysis and molecular dynamics we showed that curcumin has a high probability to bind at the interface of the tubulin dimer close to the vinblastine binding site. All the data presented indicate that curcumin may inhibit Giardia proliferation by perturbing microtubules. Copyright © 2017. Published by Elsevier B.V.

Development of T m -shift genotyping method for detection of cat-derived Giardia lamblia.

PubMed

Pan, Weida; Fu, Yeqi; Abdullahi, Auwalu Yusuf; Wang, Mingwei; Shi, Xianli; Yang, Fang; Yu, Xingang; Yan, Xinxin; Zhang, Pan; Hang, Jianxiong; Li, Guoqing

2017-04-01

To develop T m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5'-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10 -5 and 4.88 × 10 -5  ng/μL samples of assemblage A and F standard plasmids. The T m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia.

Multiplex PCR detection of Cryptosporidium sp, Giardia lamblia and Entamoeba histolytica directly from dried stool samples from Guinea-Bissauan children with diarrhoea.

PubMed

Mero, Sointu; Kirveskari, Juha; Antikainen, Jenni; Ursing, Johan; Rombo, Lars; Kofoed, Poul-Erik; Kantele, Anu

2017-09-01

In developing countries, diarrhoea is the most common cause of death for children under five years of age, with Giardia lamblia, Cryptosporidium and Entamoeba histolytica as the most frequent pathogenic parasites. Traditional microscopy for stool parasites has poor sensitivity and specificity, while new molecular methods may provide more accurate diagnostics. In poor regions with sample storage hampered by uncertain electricity supply, research would benefit from a method capable of analysing dried stools. A real-time multiplex PCR method with internal inhibition control was developed for detecting Giardia lamblia, Cryptosporidium hominis/parvum and Entamoeba histolytica directly from stool specimens. Applicability to dried samples was checked by comparing with fresh ones in a small test material. Finally, the assay was applied to dried specimens collected from Guinea-Bissauan children with diarrhoea. The PCR's analytical sensitivity limit was 0.1 ng/ml for G. lamblia DNA, 0.01 ng/ml for E. histolytica DNA and 0.1 ng/ml for Cryptosporidium sp. In the test material, the assay performed similarly with fresh and dried stools. Of the 52 Guinea-Bissauan samples, local microscopy revealed a parasite in 15%, while PCR detected 62% positive for at least one parasite: 44% of the dried samples had Giardia, 23% Cryptosporidium and 0% E. histolytica. Our new multiplex real-time PCR for protozoa presents a sensitive method applicable to dried samples. As proof of concept, it worked well on stools collected from Guinea-Bissauan children with diarrhoea. It provides an epidemiological tool for analysing dried specimens from regions poor in resources.

Intestinal Protozoal Parasites in Diarrheal Children and Associated Risk Factors at Yirgalem Hospital, Ethiopia: A Case-Control Study.

PubMed

Firdu, Teshome; Abunna, Fufa; Girma, Mekonnen

2014-01-01

Aim. A case-control study was conducted to determine the prevalence of G. lamblia, Cryptosporidium, spp and E. histolytica/dispar in diarrheal children at Yirgalem Hospital from February 2011 to August. Subjects and Methods. A total of 230 children participated in the study of which 115 (50%) were cases and 115 (50%) were controls. A single stool sample was collected and examined by direct saline wet mount, formol-ether concentration, and modified Ziehl-Neelsen. Results. Eighty-four (36.52%) were positive for at least one intestinal parasites (57 (49.56%) from diarrheal children and 27 (23.47%) out of nondiarrheal children). The prevalence of G. lamblia, Cryptosporidium spp, and E. histolytica/dispar was 15.65%, 9.56%, and 4.35% in children with diarrhea and 1.74%, 5.21%, and 1.74% in those without it, respectively. Cryptosporidium spp and E. histolytica/dispar revealed higher infection in males (10.81% and 5.4%, resp.) than in females (7.32% and 2.43%, resp.). G. lamblia infection was higher in females (29.27%) than in males (8.11%). Cryptosporidium spp infection was higher in the age groups of ≤4 years old (53.84%). Significant difference was seen between 10 and 13 (7.69%) years old. Higher prevalence of E. histolytica/dispar was found in 5-9 years (85.71%) than ≤4 years old (14.28%). Conclusion. Cryptosporidium spp, E. histolytica/dispar, and G. lamblia were higher in children with diarrhea than in those without it.

[Experimental model of activated Lamblia (Giardia) muris infection in albino mice].

PubMed

Irikov, O A; Kovalenko, F P

2007-01-01

Experimental L. muris infection was reproduced in 100% of the intact albino mice intragastrically given levomycin in an average total dose of 15.88-34.84 or 0.88-1.02 g/kg for 18-34 days. With levomycin administration, the intensity of giardiasis was 1121.6-8540.1 (mean 4830.9) thousand L. muris trophozoites per animal. The total number of trophozoites per animal decreased to 302.2-3481.4 (mean 1546.4) thousand and 28.1-324.0 (mean 109.4) thousand specimens 5-8 and 11-13 days after discontinuation of the antibiotic, respectively. The maximum number of L. muris trophozoites was observed in the proximal and middle portions of the murine small intestine during and after the administration oflevomycin. The highest isolation of cysts was seen 12-14 days after the initiation of administration of the antibiotic. Following 8-10 days of terminations of a course of levomycin therapy the native smear of animal feces showed no Lamblia cysts. In mice with activated infection, the isolation rate of Lamblia cysts was directly related to the intensity of intestinal infection with trophozoites of the parasite.

Flagellar generated flow mediates attachment of Giardia Lamblia

NASA Astrophysics Data System (ADS)

Picou, Theodore; Polackwich, Jamie; Burrola Gabilondo, Beatriz; McAllister, Ryan; Powers, Tom; Elmendorf, Heidi; Urbach, Jeff

2011-11-01

Giardia lamblia is a protozoan parasite responsible for widespread diarrheal disease in humans and animals worldwide. Attachment to the host intestinal mucosa and resistance to peristalsis is necessary for establishing infection, but the physical basis for this attachment is poorly understood. We report results from confocal fluorescence microscopy that demonstrate that the regular beating of the posterior flagella generate a flow through the ventral disk, a suction-cup shaped structure that is against the substrate during attachment. Finite element simulations show that the negative pressure generated by the flow is consistent with the measured force of attachement between the parasite and its substrate.

Potential causative agents of acute gastroenteritis in households with preschool children: prevalence, risk factors, clinical relevance and household transmission.

PubMed

Heusinkveld, M; Mughini-Gras, L; Pijnacker, R; Vennema, H; Scholts, R; van Huisstede-Vlaanderen, K W; Kortbeek, T; Kooistra-Smid, M; van Pelt, W

2016-10-01

Acute gastroenteritis (AGE) morbidity remains high amongst preschool children, posing a significant societal burden. Empirical data on AGE-causing agents is needed to gauge their clinical relevance and identify agent-specific targets for control. We assessed the prevalence, risk factors and association with symptoms for enteropathogens in households with preschool children. A monthly-repeated cross-sectional survey of enteropathogens in households with preschool children was performed. A parent-child pair per household (n = 907 households) provided faecal samples and reported their symptoms and potential risk exposures. Samples were tested by multiplex reverse transcription polymerase chain reaction (RT-PCR) for 19 enteropathogens. Associations were assessed using logistic regression. 28.3 % of children (n = 981) and 15.6 % of parents (n = 971) carried pathogenic bacteria and/or Escherichia coli-associated pathogenicity genes, and 6.5 % and 3.3 % carried viruses, respectively. Giardia lamblia (4.6 % of children, 2.5 % of parents) and Dientamoeba fragilis (36 %, 39 %, respectively) were the main parasites, and were associated with pet exposure. Living in rural areas was associated with carriage of pathogenic E. coli, norovirus I and D. fragilis. Pathogenic E. coli was associated with summertime and livestock exposure. Attending day-care centres increased the risk of carrying norovirus, sapovirus and G. lamblia. Viruses occurred mainly in winter and were associated with AGE symptoms. Child-parent associations were found for bacterial pathogenicity genes, viruses, G. lamblia and D. fragilis. Enteropathogens spread widely in households with preschool children, particularly viruses, which more often cause symptoms. While bacteria predominate during summer and in those exposed to livestock, viruses predominate in wintertime and, like G. lamblia, are widespread amongst day-care centre attendees.

Antiprotozoal Constituents from Annona cherimola Miller, a Plant Used in Mexican Traditional Medicine for the Treatment of Diarrhea and Dysentery

PubMed Central

Calzada, Fernando; Correa-Basurto, Jose; Barbosa, Elizabeth; Mendez-Luna, David; Yepez-Mulia, Lilian

2017-01-01

Background: Annona cherimola Miller (Annonaceae) is a medicinal plant frequently recommended in Mexican traditional medicine for the treatment of gastrointestinal disorders such as diarrhea and dysentery. Objective: This work was undertaken to obtain information that support the traditional use of A. cherimola, on pharmacological basis using in vitro and computational experiments. Material and Methods: Bioassay-guided fractionation of the ethanol extract of the leaves of A. cherimola afforded five phenolic compounds: caffeic acid, quercetin, kaempferol, nicotinflorin, and rutin. Results: The in vitro antiprotozoal assay showed that kaempferol was the most potent antiamoebic and antigiardial compound with IC50 values of 7.9 μg/mL for Entamoeba histolytica and 8.7 μg/mL for Giardia lamblia. Computational molecular docking study showed that kaempferol interacted in a region different than metronidazole in the enzyme pyruvate: ferredoxin oxidoreductase (PFOR). Conclusion: Considering that PFOR is a target of metronidazole; kaempferol may be a lead compound for the development of novel antiprotozoal agent. Also, these findings give support to the use of A. cherimola in the traditional medicine from México for the treatment of diarrhea and dysentery. SUMMARY Bioassay-guided fractionation of the ethanol extract of the leaves of Annona cherimola afforded five phenolic compounds: caffeic acid, quercetin, kaempferol, nicotinflorin and rutin. The in vitro antiprotozoal assay showed that kaempferol was the most potent antiamoebic and antigiardial compound with IC50 values of 7.9 μg/mL for Entamoeba histolytica and 8.7 μg/mL for Giardia lamblia. Computational molecular docking study showed that kaempferol interacted in a region different that metronidazole in the enzyme pyruvate: ferredoxin oxidoreductase. Abbreviations used: PFOR:Pyruvate:ferredoxin oxidoreductase, G: lamblia: Giardia lamblia, E: histolytica: Entamoeba histolytica PMID:28216899

Cross-species transmission of Giardia spp.: inoculation of beavers and muskrats with cysts of human, beaver, mouse, and muskrat origin.

PubMed Central

Erlandsen, S L; Sherlock, L A; Januschka, M; Schupp, D G; Schaefer, F W; Jakubowski, W; Bemrick, W J

1988-01-01

Giardia cysts isolated from humans, beavers, mice, and muskrats were tested in cross-species transmission experiments for their ability to infect either beavers or muskrats. Giardia cysts, derived from multiple symptomatic human donors and used for inoculation of beavers or muskrats, were shown to be viable by incorporation of fluorogenic dyes, excystation, and their ability to produce infections in the Mongolian gerbil model. Inoculation of beavers with 5 x 10(5) Giardia lamblia cysts resulted in the infection of 75% of the animals (n = 8), as judged by the presence of fecal cysts or intestinal trophozoites at necropsy. The mean prepatent period was 13.1 days. An infective dose experiment, using 5 x 10(1) to 5 x 10(5) viable G. lamblia cysts collected by fluorescence-activated cell sorting, demonstrated that doses of between, less than 50, and less than 500 viable cysts were required to produce infection in beavers. Scanning electron microscopy of beaver small intestine revealed that attachment of G. lamblia trophozoites produced lesions in the microvillous border. Inoculation of muskrats with G. lamblia cysts produced infections when the dose of cysts was equal to or greater than 1.25 x 10(5). The inoculation of beavers with Giardia ondatrae or Giardia muris cysts did not produce any infection; however, the administration to muskrats of Giardia cysts of beaver origin resulted in the infection of 62% of the animals (n = 8), with a prepatent period of 5 days. Our results demonstrated that beavers and muskrats could be infected with Giardia cysts derived from humans, but only by using large numbers of cysts.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:3063208

Comparison of four rapid diagnostic tests, ELISA, microscopy and PCR for the detection of Giardia lamblia, Cryptosporidium spp. and Entamoeba histolytica in feces.

PubMed

Van den Bossche, Dorien; Cnops, Lieselotte; Verschueren, Jacob; Van Esbroeck, Marjan

2015-03-01

Microscopy is the diagnostic reference standard for the detection of parasites, but it is labor-intensive and requires experience. Rapid diagnostic tests (RDTs) can provide an alternative to microscopy. RDTs from four different manufacturers were compared to enzyme-linked immunosorbent assay (ELISA), microscopy and/or parasite-specific real-time PCR: ImmunoCardSTAT!®CGE (Meridian Bioscience Inc., Cincinnati, Ohio, USA) (A), Crypto/Giardia Duo-Strip (Coris Bioconcepts, Gembloux, Belgium) (B), RIDA®QUICK Cryptosporidium/Giardia/Entamoeba Combi (R-BioPharm, Darmstadt, Germany) (C) and Giardia/Cryptosporidium Quik Chek (Techlab Inc., Blacksburg, Virginia, USA) (D). Thirty frozen samples were analyzed retrospectively. For Giardia lamblia (n=12) and Cryptosporidium (n=12) sensitivities ranged from 58% (B), over 83% (A, C) to 100% (D) and from 92% (B) to 100% (A, C, D), respectively. Specificity for both G. lamblia and Cryptosporidium was 100% for all RDT brands. Sensitivity for Entamoeba histolytica (n=5) was 100%, while specificity reached 80% (A) to 88% (C). In a prospective study, fresh samples were tested. For G. lamblia (n=30), sensitivity ranged from 66% (B), over 79% (A) and 83% (C) to 100% (D) and specificity varied between 94% (D) and 100% (A, B, C). For Cryptosporidium (n=3), sensitivity was 100% for all brands except (B) (67%) and specificities were 95% (A, B), 98% (C) and 100% (D). E. histolytica (n=1) was detected by both (A) and (C), while specificity was 81% and 87% respectively. RDTs can be a valuable tool when microscopic expertise is poor and in remote and outbreak settings where other techniques are often not available and rapid diagnosis is required. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification and Validation of Small-Gatekeeper Kinases as Drug Targets in Giardia lamblia

PubMed Central

Hennessey, Kelly M.; Smith, Tess R.; Xu, Jennifer W.; Alas, Germain C. M.; Ojo, Kayode K.; Merritt, Ethan A.

2016-01-01

Giardiasis is widely acknowledged to be a neglected disease in need of new therapeutics to address toxicity and resistance issues associated with the limited available treatment options. We examined seven protein kinases in the Giardia lamblia genome that are predicted to share an unusual structural feature in their active site. This feature, an expanded active site pocket resulting from an atypically small gatekeeper residue, confers sensitivity to “bumped” kinase inhibitors (BKIs), a class of compounds that has previously shown good pharmacological properties and minimal toxicity. An initial phenotypic screen for biological activity using a subset of an in-house BKI library found that 5 of the 36 compounds tested reduced trophozoite growth by at least 50% at a concentration of 5 μM. The cellular localization and the relative expression levels of the seven protein kinases of interest were determined after endogenously tagging the kinases. Essentiality of these kinases for parasite growth and infectivity were evaluated genetically using morpholino knockdown of protein expression to establish those that could be attractive targets for drug design. Two of the kinases were critical for trophozoite growth and attachment. Therefore, recombinant enzymes were expressed, purified and screened against a BKI library of >400 compounds in thermal stability assays in order to identify high affinity compounds. Compounds with substantial thermal stabilization effects on recombinant protein were shown to have good inhibition of cell growth in wild-type G. lamblia and metronidazole-resistant strains of G. lamblia. Our data suggest that BKIs are a promising starting point for the development of new anti-giardiasis therapeutics that do not overlap in mechanism with current drugs. PMID:27806042

Detection and molecular characterisation of Giardia lamblia genotypes in Sharjah, United Arab Emirates.

PubMed

ElBakri, Ali; Samie, Amidou; Bessong, Pascal; Potgieter, Natasha; Odeh, Ra'ed Abu

2014-08-01

No data are available on Giardia lamblia genotypes in the United Arab Emirates (UAE). This study aimed to identify G. lamblia from DNA extracted from human stool samples to gain information on its prevalence and to perform molecular analysis on isolates collected from expatriates from different localities residing in Sharjah, UAE. In total, 111 healthy expatriates residing in Sharjah were screened for G. lamblia using nested PCR amplification of the small subunit ribosomal RNA (ssu-rRNA) gene. Positive samples were genotyped using a nested PCR amplifying the triosephosphate isomerase (tpi) gene to differentiate between the two human assemblages (A and B). A subset of the PCR products (n=23) were sequenced and their phylogenetic relationships were determined. Of the 111 participants, 67 (60.4%) were identified as positive for the ssu-rRNA gene. When genotyped for the tpi gene, 18.9% (21/111) were of assemblage A, 17.1% (19/111) belonged to assemblage B and 5.4% (6/111) showed patterns compatible with mixed infections. A strong correlation between the presence of diarrhoea and assemblage B was observed (χ(2)=10.553; p=0.001). Moreover, an association was also observed between mixed infections (A+B) and diarrhoea (χ(2)=8.899; p=0.003). No correlation between age, gender and geographic origin of the infected individual was noted. Phylogenetic analysis showed three clusters for the tpi gene. No relationship between the clusters and the origin of samples was noted. This study is the first to determine the infection rate and genotypic composition of Giardia in Sharjah, UAE. © The Author 2014. 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.

An In Vitro Evaluation of Ozonized Organic Extra-Virgin Olive Oil on Giardia Lamblia Cysts.

PubMed

Boland-Nazar, Najmeh Sadat; Eslamirad, Zahra; Sarmadian, Hossein; Ghasemikhah, Reza

2016-11-01

Giardia lamblia is a common intestinal parasite that has been reported all over the world. This study was conducted to evaluate the effect of ozonized organic extra-virgin olive oil on the cyst of G. lamblia . The olive oil was ozonized based on international standards and confirmed by the world health organization (WHO) at various times in a generator. The ozone concentration of olive oil was adjusted at 32, 64, 96, 128, 160 mg/g based on ozone absorption. Giardia lamblia cysts were isolated from heavily infected stool samples and the sucrose gradient flotation technique. Five groups of triple tubes containing Giardia cysts were exposed to olive oil with 32, 64, 96, 128, 160 ozone concentrations, and the sixth and seventh groups were exposed to non-ozonized olive oil and normal saline, respectively. The tubes were placed at room temperature, and every four hours, the mortality of the Giardia cysts was assessed. The results showed that the first five groups' mortality rate of Giardia cysts reached 100% in 100 hours. An increasing concentration of ozone in olive oil leads to an increase in the mortality rate of Giardia cysts. The results showed a significant difference in the mean time of the mortality in all the groups (P ≤ 0.05). Furthermore, the higher fatality effect of ozonized organic extra-virgin olive oil (Ozonized Olive Oil = OZO) was proved in comparison with metronidazole in vitro. We concluded that ozonized organic extra-virgin olive oil was a growth inhibitor of Giardia cysts, and concerning its compatibility with a biological system, it is recommended for further clinical trials.

Effect of enteric parasitic infection on serum trace elements and nutritional status in upper Egyptian children

PubMed Central

Yones, Doaa A; Galal, Lamia A; Abdallah, Alameldin M; Zaghlol, Khaled S

2015-01-01

Introduction: Enteric parasitic infections still the cause of major health problems among Egyptian children as they have great morbid effect on their physical and cognitive development. Malnutrition makes children more prone to micronutrient deficiency and subsequently more vulnerable to parasitic infection. The present study aimed to identify the effect of intestinal parasitism on micronutrient serum level and children nutritional status. Materials and Methods: A case control study was carried out on children from 1 to 6 years old who were attending the Assiut University Children Hospital outpatient clinic, after parasitological stool examination they were divided into Group 1 (G1, n: 60) positive with enteric parasite and Group 2 (G2, n: 60) age and sex matched and free of parasites. Anthropometric measurements were expressed as weight for age (WFA), height for age (HFA), and weight for height (WFH) parameters. Serum zinc (Zn) and copper (Cu) were determined by atomic absorption spectrophotometer. Results: Intestinal parasitic infection rate was 55.7%; more commonly detected parasites were Giardia lamblia 28%, Cryptosporidium sp. 20%, and polyparasitism 18%. All children (G1 and G2) were underweight (WFA) while 63% of G1 were malnourished, either in the form of wasting (WFH) or stunting (HFA) or both aspects. Stunting and wasting were more dominant among children infected with G. lamblia and Cryptosporidium sp. and most of them were below 2 years old. Conclusions: Coincident decrease in serum Zn level and an increase of serum Cu was more prominent among G. lamblia and Cryptosporidium sp. patients. G. lamblia and Cryptosporidium sp. were found to be more associated with nonstandard children nutritional status beside to an altered micronutrient level. PMID:25709950

Association between Helicobacter pylori and intestinal parasites in an Añu indigenous community of Venezuela.

PubMed

Fuenmayor-Boscán, Alisbeth D; Hernández, Ileana M; Valero, Kutchynskaya J; Paz, América M; Sandrea, Lisette B; Rivero, Zulbey

2016-03-01

Helicobacter pylori (Hp) and enteroparasite infections are highly prevalent in populations with poor living conditions, like the Amerindian communities. Identifying associations between both types of infectious agents could help to detect shared risk factors or transmission routes in these minority ethnic groups. Therefore, the prevalence and association between Hp and enteroparasites were investigated in an indigenous community whose living conditions favor such infectious diseases. Seropositivity (anti-Hp-specific IgG) and active infection (stool antigen test), intestinal parasitosis (direct and concentrated coproparasitological test, methylene blue, and Kinyoun stains), and risk factors for fecal-oral transmission were determined in 167 children and 151 adults of the Añu indigenous community living at the Sinamaica Lagoon, in Venezuela. A high rate of Hp infection (seropositivity and active infection) and enteroparasitosis was evidenced, as expected. Some significant associations were detected: direct associations between Hp and polyparasitic infection, helminths, and protozoan (particularly in children); inverse association between Hp and Giardia lamblia. No shared epidemiological factors were identified for Hp and the detected intestinal parasites, probably due to overlapping factors. Direct associations detected support the participation of the fecal-oral route in the transmission of the involved infectious agents. Inverse relationship (Hp) and G. lamblia may suggest the existence of antagonistic interactions between them. Further research is required to elucidate the mechanisms underlying these associations.

A new-generation 5-nitroimidazole can induce highly metronidazole-resistant Giardia lamblia in vitro

PubMed Central

Dunn, Linda A.; Burgess, Anita G.; Krauer, Kenia G.; Eckmann, Lars; Vanelle, Patrice; Crozet, Maxime D.; Gillin, Frances D.; Upcroft, Peter; Upcroft, Jacqueline A.

2010-01-01

The 5-nitroimidazole (NI) compound C17, with a side chain carrying a remote phenyl group in the 2-position of the imidazole ring, is at least 14-fold more active against the gut protozoan parasite Giardia lamblia than the 5-NI drug metronidazole (MTR), with a side chain in the 1-position of the imidazole ring, which is the primary drug for the treatment of giardiasis. Over 10 months, lines resistant to C17 were induced in vitro and were at least 12-fold more resistant to C17 than the parent strains. However, these lines had ID90 values (concentration of drug at which 10% of control parasite ATP levels are detected) for MTR of >200 μM, whilst lines induced to be highly resistant to MTR in vitro have maximum ID90 values around 100 μM (MTR-susceptible isolates typically have an ID90 of 5–12.8 μM). The mechanism of MTR activation in Giardia apparently involves reduction to toxic radicals by the activity of pyruvate:ferredoxin oxidoreductase (PFOR) and the electron acceptor ferredoxin. MTR-resistant Giardia have decreased PFOR activity, which is consistent with decreased activation of MTR in these lines, but C17-resistant lines have normal levels of PFOR. Therefore, an alternative mechanism of resistance in Giardia must account for these super-MTR-resistant cells. PMID:20456926

Hydrologic and Vegetative Removal of Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii Surrogate Microspheres in Coastal Wetlands

PubMed Central

Hogan, Jennifer N.; Daniels, Miles E.; Watson, Fred G.; Oates, Stori C.; Miller, Melissa A.; Conrad, Patricia A.; Shapiro, Karen; Hardin, Dane; Dominik, Clare; Melli, Ann; Jessup, David A.

2013-01-01

Constructed wetland systems are used to reduce pollutants and pathogens in wastewater effluent, but comparatively little is known about pathogen transport through natural wetland habitats. Fecal protozoans, including Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii, are waterborne pathogens of humans and animals, which are carried by surface waters from land-based sources into coastal waters. This study evaluated key factors of coastal wetlands for the reduction of protozoal parasites in surface waters using settling column and recirculating mesocosm tank experiments. Settling column experiments evaluated the effects of salinity, temperature, and water type (“pure” versus “environmental”) on the vertical settling velocities of C. parvum, G. lamblia, and T. gondii surrogates, with salinity and water type found to significantly affect settling of the parasites. The mesocosm tank experiments evaluated the effects of salinity, flow rate, and vegetation parameters on parasite and surrogate counts, with increased salinity and the presence of vegetation found to be significant factors for removal of parasites in a unidirectional transport wetland system. Overall, this study highlights the importance of water type, salinity, and vegetation parameters for pathogen transport within wetland systems, with implications for wetland management, restoration efforts, and coastal water quality. PMID:23315738

Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system.

PubMed

Kumar, Thulasi; Abd Majid, Mohamad Azlan; Onichandran, Subashini; Jaturas, Narong; Andiappan, Hemah; Salibay, Cristina C; Tabo, Hazel A L; Tabo, Norbel; Dungca, Julieta Z; Tangpong, Jitbanjong; Phiriyasamith, Sucheep; Yuttayong, Boonyaorn; Polseela, Raxsina; Do, Binh Nhu; Sawangjaroen, Nongyao; Tan, Tian-Chye; Lim, Yvonne A L; Nissapatorn, Veeranoot

2016-01-13

Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays. A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency's methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays. Cryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993). The presence of (oo)cysts in the water samples means that there is potential risk for zoonotic disease transmission in the studied countries. Detection using qPCR is feasible for quantifying both pathogenic C. parvum and G. lamblia in large water samples.

A microfluidic laser scattering sensor for label-free detection of waterborne pathogens

NASA Astrophysics Data System (ADS)

Wei, Huang; Yang, Limei; Li, Feng

2016-10-01

A microfluidic-based multi-angle laser scattering (MALS) sensor capable of acquiring scattering pattern of single particle is demonstrated. The size and relative refractive index (RI) of polystyrene (PS) microspheres were deduced with accuracies of 60 nm and 0.001 by analyzing the scattering patterns. We measured scattering patterns of waterborne parasites i.e., cryptosporidium parvum (c.parvum) and giardia lamblia (g.lamblia), and some other representative species in 1 L water within 1 hour, and the waterborne parasites were identified with accuracy better than 96% by classification of distinctive scattering patterns with a support-vector-machine (SVM) algorithm. The system provides a promising tool for label-free and rapid detection of waterborne parasites.

Flagellar generated flow mediates attachment of Giardia lamblia

NASA Astrophysics Data System (ADS)

Urbach, Jeffrey; Luo, Haibei; Picou, Theodore; McAllister, Ryan; Elmendorf, Heidi

2011-03-01

Giardia lamblia is a protozoan parasite responsible for widespread diarrheal disease in humans and animals worldwide. Attachment to the host intestinal mucosa and resistance to peristalsis is necessary for establishing infection, but the physical basis for this attachment is poorly understood. We report results from TIRF and confocal fluorescence microscopy that demonstrate that the regular beating of the posterior flagella generate a flow through the ventral disk, a suction-cup shaped structure that is against the substrate during attachment. Finite element simulations are used to compare the negative pressure generated by the flow to the measured attachment force and the expected performance of the flagellar pump. NIH grant 1R21AI062934-0.

Detection of pathogenic micro-organisms on children's hands and toys during play.

PubMed

Martínez-Bastidas, T; Castro-del Campo, N; Mena, K D; Castro-del Campo, N; León-Félix, J; Gerba, C P; Chaidez, C

2014-06-01

This study aimed to determine if the children's leisure activities impact the presence of pathogens on their hands and toys. To assess the microbiological hazard in playground areas, a pilot study that included 12 children was conducted. We then conducted an intervention study; children's hands and toys were washed before playing. Faecal coliforms, pathogenic bacteria and Giardia lamblia were quantified by membrane filtration, selective media and flotation techniques, respectively; rotavirus, hepatitis A and rhinovirus by RT-PCR. Pilot study results revealed faecal contamination on children's hands and toys after playing on sidewalks and in public parks. Pathogenic bacteria, hepatitis A and G. lamblia on children's hands were also found. In the intervention study, Staphylococcus aureus and Klebsiella pneumoniae were found on children's hands at concentrations up to 2·5 × 10(4) and 1 × 10(4) CFU hands(-1), respectively. E. coli and Kl. pneumoniae were detected on toys (2·4 × 10(3) and 2·7 × 10(4) CFU toy(-1), respectively). Salmonella spp, Serratia spp and G. lamblia cysts were also present on toys. Children's play activities influence microbial presence on hands and toys; the transfer seems to occur in both ways. Control strategy needs to be implemented to protect children from infectious diseases. © 2014 The Society for Applied Microbiology.

Expression, purification, crystallization and preliminary X-ray diffraction analysis of α-11 giardin from Giardia lamblia

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

Pathuri, Puja; Nguyen, Emily Tam; Luecke, Hartmut, E-mail: hudel@uci.edu

2006-11-01

α-11 giardin from the intestinal protozoan parasite, G. lamblia has been cloned, expressed, purified and crystallized under two different conditions and in two different space groups. Crystals from the first condition diffracted to 1.1 Å and belong to a primitive orthorhombic space group and crystals obtained in the second condition diffracted to 2.93 Å and belong to a primitive monoclinic space group. α-11 Giardin, a protein from the annexin superfamily, is a 35.0 kDa protein from the intestinal protozoan parasite Giardia lamblia which triggers a form of diarrhea called giardiasis. Here, the cloning, expression, purification and the crystallization of α-11more » giardin under two different conditions and in two different space groups is reported. Crystals from the first condition diffracted to 1.1 Å and belong to a primitive orthorhombic space group, while crystals from the second condition, which included calcium in the crystallization solution, diffracted to 2.93 Å and belong to a primitive monoclinic space group. Determination of the detailed atomic structure of α-11 giardin will provide a better insight into its biological function and might establish whether this class of proteins is a potential drug target against giardiasis.« less

Dietary lipids containing gangliosides reduce Giardia muris infection in vivo and survival of Giardia lamblia trophozoites in vitro.

PubMed

Suh, M; Belosevic, M; Clandinin, M T

2004-06-01

We examined whether a ganglioside supplemented diet affected the course of Giardia muris infection in mice and survival of Giardia lamblia trophozoites in vitro. Female CD-1 mice were fed 1 of 5 experimental diets: standard lab chow as a control diet; semi-synthetic diets containing 20% (w/w) triglyceride based on the fat composition of a conventional infant formula; triglyceride diet; triglyceride diet containing a low level of ganglioside (0.1% w/w); and triglyceride diet containing a high level of ganglioside (1.0% w/w of diet). After 2 weeks of feeding, mice were inoculated with G. muris by gastric intubation and fed the experimental diets during the course of the infection. Cysts released in the faeces and trophozoites present in the small intestine were enumerated at various times post-infection. The average cyst output and the number of trophozoites during the course of the infection in mice fed ganglioside-containing diet were found to be significantly lower (3-log10 reduction) compared to animals fed control diets. The results of in vitro growth studies indicated that gangliosides may be directly toxic to the parasites. Thus, gangliosides have a protective effect against G. muris infection in vivo and affect the survival of G. lamblia trophozoites in vitro.

Development of species-specific rDNA probes for Giardia by multiple fluorescent in situ hybridization combined with immunocytochemical identification of cyst wall antigens.

PubMed

Erlandsen, Stanley L; Jarroll, Edward; Wallis, Peter; van Keulen, Harry

2005-08-01

In this study, we describe the development of fluorescent oligonucleotide probes to variable regions in the small subunit of 16S rRNA in three distinct Giardia species. Sense and antisense probes (17-22 mer) to variable regions 1, 3, and 8 were labeled with digoxygenin or selected fluorochomes (FluorX, Cy3, or Cy5). Optimal results were obtained with fluorochome-labeled oligonucleotides for detection of rRNA in Giardia cysts. Specificity of fluorescent in situ hybridization (FISH) was shown using RNase digestion and high stringency to diminish the hybridization signal, and oligonucleotide probes for rRNA in Giardia lamblia, Giardia muris, and Giardia ardeae were shown to specifically stain rRNA only within cysts or trophozoites of those species. The fluorescent oligonucleotide specific for rRNA in human isolates of Giardia was positive for ten different strains. A method for simultaneous FISH detection of cysts using fluorescent antibody (genotype marker) and two oligonucleotide probes (species marker) permitted visualization of G. lamblia and G. muris cysts in the same preparation. Testing of an environmental water sample revealed the presence of FISH-positive G. lamblia cysts with a specific rDNA probe for rRNA, while negative cysts were presumed to be of animal or bird origin.

Validation of housekeeping genes as an internal control for gene expression studies in Giardia lamblia using quantitative real-time PCR.

PubMed

Marcial-Quino, Jaime; Fierro, Francisco; De la Mora-De la Mora, Ignacio; Enríquez-Flores, Sergio; Gómez-Manzo, Saúl; Vanoye-Carlo, America; Garcia-Torres, Itzhel; Sierra-Palacios, Edgar; Reyes-Vivas, Horacio

2016-04-25

The analysis of transcript levels of specific genes is important for understanding transcriptional regulation and for the characterization of gene function. Real-time quantitative reverse transcriptase PCR (RT-qPCR) has become a powerful tool to quantify gene expression. The objective of this study was to identify reliable housekeeping genes in Giardia lamblia. Twelve genes were selected for this purpose, and their expression was analyzed in the wild type WB strain and in two strains with resistance to nitazoxanide (NTZ) and metronidazole (MTZ), respectively. RefFinder software analysis showed that the expression of the genes is different in the three strains. The integrated data from the four analyses showed that the NADH oxidase (NADH) and aldolase (ALD) genes were the most steadily expressed genes, whereas the glyceraldehyde-3-phosphate dehydrogenase gene was the most unstable. Additionally, the relative expression of seven genes were quantified in the NTZ- and MTZ-resistant strains by RT-qPCR, using the aldolase gene as the internal control, and the results showed a consistent differential pattern of expression in both strains. The housekeeping genes found in this work will facilitate the analysis of mRNA expression levels of other genes of interest in G. lamblia. Copyright © 2016 Elsevier B.V. All rights reserved.

Cloning of Giardia lamblia heat shock protein HSP70 homologs: implications regarding origin of eukaryotic cells and of endoplasmic reticulum.

PubMed Central

Gupta, R S; Aitken, K; Falah, M; Singh, B

1994-01-01

The genes for two different 70-kDa heat shock protein (HSP70) homologs have been cloned and sequenced from the protozoan Giardia lamblia. On the basis of their sequence features, one of these genes corresponds to the cytoplasmic form of HSP70. The second gene, on the basis of its characteristic N-terminal hydrophobic signal sequence and C-terminal endoplasmic reticulum (ER) retention sequence (Lys-Asp-Glu-Leu), is the equivalent of ER-resident GRP78 or the Bip family of proteins. Phylogenetic trees based on HSP70 sequences show that G. lamblia homologs show the deepest divergence among eukaryotic species. The identification of a GRP78 or Bip homolog in G. lamblia strongly suggests the existence of ER in this ancient eukaryote. Detailed phylogenetic analyses of HSP70 sequences by boot-strap neighbor-joining and maximum-parsimony methods show that the cytoplasmic and ER homologs form distinct subfamilies that evolved from a common eukaryotic ancestor by gene duplication that occurred very early in the evolution of eukaryotic cells. It is postulated that because of the essential "molecular chaperone" function of these proteins in translocation of other proteins across membranes, duplication of their genes accompanied the evolution of ER or nucleus in the eukaryotic cell ancestor. The presence in all eukaryotic cytoplasmic HSP70 homologs (including the cognate, heat-induced, and ER forms) of a number of autapomorphic sequence signatures that are not present in any prokaryotic or organellar homologs provides strong evidence regarding the monophyletic nature of eukaryotic lineage. Further, all eukaryotic HSP70 homologs share in common with the Gram-negative group of eubacteria a number of sequence features that are not present in any archaebacterium or Gram-positive bacterium, indicating their evolution from this group of organisms. Some implications of these findings regarding the evolution of eukaryotic cells and ER are discussed. Images PMID:8159675

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

PubMed

Rayan, Paran; Verghese, Susan; McDonnell, Pauline Ann

2010-01-01

Environmental factors affect the dissemination and distribution of intestinal parasites in human communities. To comprehend the prevalence of parasitic infestation and to examine whether geographical location and age also influence the prevalence of infection, fecal samples from 195 school children (rural = 95; male = 39; female = 56) (urban = 100; male = 60; female = 40) of five age groups ranging from 5 to 11 years in two different socio-economic zones (rural and urban) were screened for specific intestinal parasites using standard histological techniques. Percentage incidences of parasitic species found in fecal wet mounts and concentrates in rural children were Entamoeba coli (25.3%), Giardia lamblia (17.9%), Blastocystis hominis (14.7%), Entamoeba histolytica (4.2%), Iodamoeba butschlii (1.1%), Hymenolepis nana (1.1%) and Ascaris lumbricoides (1.1%). Whereas the percentage incidences among urban children were E. coli (26%), A. lumbricoides (21%), B. hominis (18%), G. lamblia (14%), T. trichiura (8%), I. butschlii (4%) and A. duodenale (1%). Such findings may be related to dietary differences, living conditions and the greater use of natural anti-helminthic medicinal plants in rural communities. These results are important for both epidemiological data collection and for correlating dietary differences to intestinal parasitic diseases. We chose to investigate whether geographical location and age affect the prevalence and distribution of intestinal parasites among school children from two separate regions (rural and urban) in areas surrounding, Chennai, Tamil Nadu, India. A study of the prevalence of parasitic infestations was undertaken among primary school children, in rural and urban communities around Chennai, Tamil Nadu, India. Faecal sample collection, direct microscopic techniques, macroscopic examination and concentration techniques for identifying the parasites. Percentage incidences of parasitic species found in faecal wet mounts and concentrates were done instead of statistical analyses. Both macroscopic and microscopic examinations of faecal samples revealed that the overall percentage prevalence of parasite species encountered in rural children were Entamoeba coli (25.3%), G. lamblia (17.9%), B. hominis (14.7%), Entamoeba histolytica (4.2%), I. butschlii (1.1%), H. nana (1.1%), Ascaris lumbricoides (1.1%). The prevalence among urban children were E. coli (26%), A. lumbricoides (21%), B. hominis (18%), G. lamblia (14%), T. trichiura (8%), I. butschlii (4%) and A. duodenale (1%). Overall, comparative significant differences were noted between rural and urban children for E. histolytica (4.2 vs. 14%), G. lamblia (17.9 vs. 14%), A. lumbricoides (1.1 vs. 21%) and T. trichiura (0 vs. 8%), with the major difference being the much higher occurrence of A. lumbricoides and T. trichiura infections in urban children. One of the greatest challenges for healthcare professionals is the prevention and treatment of protozoal and helminthic parasitic infections. From our study we conclude that the prevalence of different pathogenic species of amoeba such as Entamoeba histolytica (4.2 vs. 0%) and G. lamblia (17.9 vs. 14%), (P value was equal to 1) was significantly higher among rural children compared to children from urban areas. In contrast, the prevalence of nematodes such as A. lumbricoides (21% vs. 1.1%), T. trichiura (8% vs. 0%) and A. duodenale (1%) was also significantly higher among rural children.

42 CFR 493.917 - Parasitology.

Code of Federal Regulations, 2010 CFR

2010-10-01

... vermicularis Entamoeba histolytica Entamoeba coli Giardia lamblia Endolimax nana Dientamoeba fragilis Iodamoeba... Diphyllobothrium latum Cryptosporidium sp. Plasmodium falciparum (3) For laboratories specified in paragraph (a)(1...

Metronidazole-triazole conjugates: Activity against Clostridium difficile and parasites

PubMed Central

Jarrad, Angie M.; Karoli, Tomislav; Debnath, Anjan; Tay, Chin Yen; Huang, Johnny X.; Kaeslin, Geraldine; Elliott, Alysha G.; Miyamoto, Yukiko; Ramu, Soumya; Kavanagh, Angela M.; Zuegg, Johannes; Eckmann, Lars; Blaskovich, Mark A.T.; Cooper, Matthew A.

2015-01-01

Metronidazole has been used clinically for over 50 years as an antiparasitic and broad-spectrum antibacterial agent effective against anaerobic bacteria. However resistance to metronidazole in parasites and bacteria has been reported, and improved second-generation metronidazole analogues are needed. The copper catalysed Huigsen azide-alkyne 1,3-dipolar cycloaddition offers a way to efficiently assemble new libraries of metronidazole analogues. Several new metronidazole-triazole conjugates (Mtz-triazoles) have been identified with excellent broad spectrum antimicrobial and antiparasitic activity targeting Clostridium difficile, Entamoeba histolytica and Giardia lamblia. Cross resistance to metronidazole was observed against stable metronidazole resistant C. difficile and G. lamblia strains. However for the most potent Mtz-triazoles, the activity remained in a therapeutically relevant window. PMID:26117821

[Chonic diarrhea and malabsorption due to common variable immunodeficiency, gastrectomy and giardiasis infection: a difficult nutritional management].

PubMed

Domínguez-López, M E; González-molero, I; Ramírez-Plaza, C P; Soriguer, F; Olveira, G

2011-01-01

Gastric cancer is a frequent cause of cancer-related mortality in the world. Surgery is the only potentially curative therapy, although the adverse effects of surgery are common and considerable. Common variable immunodeficiency is in many cases cause of gastrointestinal system problems such as chronic diarrhea caused by infestation with giardia lamblia, nodular lymphoid hiperplasia ad loss of villi leading frequently to malapsortion and malnutrition. Nutritional deficiencies due to malapsorption (postgastrectomy and secondary to loss of villi, giardiasis and common variable inmunodeficiency) are common. We present the case of a patient with gastric cancer who underwent a gastrectomy with common variable hipogammaglobulinemia and chronic infestation by giardia lamblia, with serious diarrhea resistant to treatment and malabsorption.

42 CFR 493.917 - Parasitology.

Code of Federal Regulations, 2013 CFR

2013-10-01

... example, the types of parasites that might be included in an approved program over time are— Enterobius vermicularis Entamoeba histolytica Entamoeba coli Giardia lamblia Endolimax nana Dientamoeba fragilis Iodamoeba...

42 CFR 493.917 - Parasitology.

Code of Federal Regulations, 2012 CFR

2012-10-01

... example, the types of parasites that might be included in an approved program over time are— Enterobius vermicularis Entamoeba histolytica Entamoeba coli Giardia lamblia Endolimax nana Dientamoeba fragilis Iodamoeba...

42 CFR 493.917 - Parasitology.

Code of Federal Regulations, 2014 CFR

2014-10-01

... example, the types of parasites that might be included in an approved program over time are— Enterobius vermicularis Entamoeba histolytica Entamoeba coli Giardia lamblia Endolimax nana Dientamoeba fragilis Iodamoeba...

Genomic minimalism in the early diverging intestinal parasite Giardia lamblia.

PubMed

Morrison, Hilary G; McArthur, Andrew G; Gillin, Frances D; Aley, Stephen B; Adam, Rodney D; Olsen, Gary J; Best, Aaron A; Cande, W Zacheus; Chen, Feng; Cipriano, Michael J; Davids, Barbara J; Dawson, Scott C; Elmendorf, Heidi G; Hehl, Adrian B; Holder, Michael E; Huse, Susan M; Kim, Ulandt U; Lasek-Nesselquist, Erica; Manning, Gerard; Nigam, Anuranjini; Nixon, Julie E J; Palm, Daniel; Passamaneck, Nora E; Prabhu, Anjali; Reich, Claudia I; Reiner, David S; Samuelson, John; Svard, Staffan G; Sogin, Mitchell L

2007-09-28

The genome of the eukaryotic protist Giardia lamblia, an important human intestinal parasite, is compact in structure and content, contains few introns or mitochondrial relics, and has simplified machinery for DNA replication, transcription, RNA processing, and most metabolic pathways. Protein kinases comprise the single largest protein class and reflect Giardia's requirement for a complex signal transduction network for coordinating differentiation. Lateral gene transfer from bacterial and archaeal donors has shaped Giardia's genome, and previously unknown gene families, for example, cysteine-rich structural proteins, have been discovered. Unexpectedly, the genome shows little evidence of heterozygosity, supporting recent speculations that this organism is sexual. This genome sequence will not only be valuable for investigating the evolution of eukaryotes, but will also be applied to the search for new therapeutics for this parasite.

Disinfection efficacy of sodium dichloroisocyanurate (NADCC) against common food-borne intestinal protozoa.

PubMed

El Zawawy, Lobna A; El-Said, Doaa; Ali, Safia M; Fathy, Fouad M

2010-04-01

The present study was conducted to investigate the efficacy of sodium dichloroisocyanurate (NaDCC) on the infective stages of common food-borne intestinal protozoa; Entamoeba histolytica (E. histolytica), Giardia lamblia (G. lamblia), Cryptosporidium, Cyclospora and Microsporidia; beside its effect on raw green vegetables and fruits. Parasites, isolated from stool of patients with diarrhea or dysentery, were exposed to NaDCC solution (1g/l) for one and two hours. Disinfection effect of NaDCC was assessed by in-vitro viability, using trypan blue stain, and infectivity bioassay in laboratory animals as indicated by fecal and intestinal parasitic counts. Raw vegetables and fruits were dipped in NaDCC solution in the same concentration and exposure time as used for treatment of the parasites. Results revealed statistically significant reductions in viability and infectivity of all examined parasites indicating their susceptibility to NaDCC. Relative variations in susceptibility were revealed; E. histolytica and G. lamblia were most susceptible (100% reduction) followed by Microsporidia then Cryptospridium and Cyclospora. NaDCC did not affect the consistency, color, taste or flavor of raw green vegetables and fruits. The proved efficacy of NaDCC, in cheap and convenient dry tablet form, makes it a promising tool in decontaminating raw vegetables and fruits from food-borne protozoan parasites at household and restaurant levels as well as in catering and fresh produce industry. It is also recommended for disinfection of food preparation surfaces and equipment.

The biology of Giardia spp.

PubMed Central

Adam, R D

1991-01-01

Gardia spp. are flagellated protozoans that parasitize the small intestines of mammals, birds, reptiles, and amphibians. The infectious cysts begin excysting in the acidic environment of the stomach and become trophozoites (the vegetative form). The trophozoites attach to the intestinal mucosa through the suction generated by a ventral disk and cause diarrhea and malabsorption by mechanisms that are not well understood. Giardia spp. have a number of unique features, including a predominantly anaerobic metabolism, complete dependence on salvage of exogenous nucleotides, a limited ability to synthesize and degrade carbohydrates and lipids, and two nuclei that are equal by all criteria that have been tested. The small size and unique sequence of G. lamblia rRNA molecules have led to the proposal that Giardia is the most primitive eukaryotic organism. Three Giardia spp. have been identified by light lamblia, G. muris, and G. agilis, but electron microscopy has allowed further species to be described within the G. lamblia group, some of which have been substantiated by differences in the rDNA. Animal models and human infections have led to the conclusion that intestinal infection is controlled primarily through the humoral immune system (T-cell dependent in the mouse model). A major immunogenic cysteine-rich surface antigen is able to vary in vitro and in vivo in the course of an infection and may provide a means of evading the host immune response or perhaps a means of adapting to different intestinal environments. Images PMID:1779932

Spatial distribution of Giardia lamblia infection among general population in Mazandaran Province, north of Iran.

PubMed

Siyadatpanah, Abolghasem; Sharif, Mehdi; Daryani, Ahmad; Sarvi, Shahabeddin; Kohansal, Mohammad Hasan; Barzegari, Saeed; Pagheh, Abdol Sattar; Gholami, Shirzad

2018-06-01

Giardia lamblia is the most prevalent intestinal parasites of humans in Iran and other in the world although information on geographical distribution of giardiasis plays significant role in identifying communities at high risk, little attention has been paid to study human giardiasis using geographical information system. Therefore, the aim of the current study was to determine temporal and spatial patterns of human giardiasis distribution to identify possible high risk areas and seasons in northern Iran. A total of 4788 people referred to health centers in the Mazandaran Province of northern Iran were surveyed January to December 2015. From each person stool sample and questionnaire with socio-demographic data were collected. Giardia infection was diagnosed using direct wet mount, formalin ether concentration and trichrome staining. The results were analyzed using Moran Local Indicators of spatial association and geographically weighted regression. The overall prevalence of Giardia infection was 4.6% (222/4788), and was significantly higher among those aged 5-9 years compared to their older peers ( P  < 0.0001). Our data showed a significant dependency between the prevalence of G. lamblia and age, job, residence, season and height from the sea ( P  < 0.0001). The results of this study provided a precise and specific spatial and temporal pattern of human giardiasis distribution in the Mazandaran Province, Iran. These evidences should be considered for proper control of disease decisions and strategies.

Co-infection of intestinal parasites and Helicobacter pylori among upper gastrointestinal symptomatic adult patients attending Mekanesalem Hospital, northeast Ethiopia.

PubMed

Seid, Abdurahaman; Tamir, Zemenu; Kasanew, Brhanu; Senbetay, Moges

2018-02-20

Intestinal parasites and H. pylori are well-known for their high prevalence worldwide. Thus, the objective of this study waste assess risk factors and co-infection of intestinal parasites and H. pylori among adult patients with upper gastrointestinal complaints. A hospital-based cross sectional study was conducted among 363 consecutive adult patients from December 10, 2015 to February 30,2016. Stool and venous blood were collected for analysis of Intestinal parasites and H. pylori infection, respectively. Data was analyzed using SPSS version 16 and logistic regression analysis was carried out to assess predictors of co-infection. A p ≤ 0.05 was considered as statistically significant. Helicobacter pylori IgG and intestinal parasites were detected in 70.25-38.3% of participants, respectively while G. lamblia accounted 22.3%. G. lamblia prevalence was significantly higher among H. pylori infected participants (COR: 2.76; 95% CI: 1.46-5.23), but E. hystolytica/dispar infection didn't show significant variation (p = 0.15). H. pylori and intestinal parasites concomitant co-infection was associated with male sex (AOR: 1.61; 95% CI: 1.01-2.56), consumption of river water (AOR: 1.85; 95% CI: 1.11-3.07) and ground/spring water (AOR: 4.10; 95% CI: 1.97-8.52). Thus, besides H. pylori investigation, upper gastrointestinal symptomatic patients should be screened for G. lamblia infection and other intestinal parasites.

Structure of the prolyl-tRNA synthetase from the eukaryotic pathogen Giardia lamblia

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

Larson, Eric T.; Kim, Jessica E.; Napuli, Alberto J.

2012-09-01

The structure of Giardia prolyl-tRNA synthetase cocrystallized with proline and ATP shows evidence for half-of-the-sites activity, leading to a corresponding mixture of reaction substrates and product (prolyl-AMP) in the two active sites of the dimer. The genome of the human intestinal parasite Giardia lamblia contains only a single aminoacyl-tRNA synthetase gene for each amino acid. The Giardia prolyl-tRNA synthetase gene product was originally misidentified as a dual-specificity Pro/Cys enzyme, in part owing to its unexpectedly high off-target activation of cysteine, but is now believed to be a normal representative of the class of archaeal/eukaryotic prolyl-tRNA synthetases. The 2.2 Å resolutionmore » crystal structure of the G. lamblia enzyme presented here is thus the first structure determination of a prolyl-tRNA synthetase from a eukaryote. The relative occupancies of substrate (proline) and product (prolyl-AMP) in the active site are consistent with half-of-the-sites reactivity, as is the observed biphasic thermal denaturation curve for the protein in the presence of proline and MgATP. However, no corresponding induced asymmetry is evident in the structure of the protein. No thermal stabilization is observed in the presence of cysteine and ATP. The implied low affinity for the off-target activation product cysteinyl-AMP suggests that translational fidelity in Giardia is aided by the rapid release of misactivated cysteine.« less

40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Giardia lamblia zero (2) Viruses zero (3) Legionella zero (4) Total coliforms (including fecal) zero coliforms and Escherichia coli (5) Cryptosporidium zero (6) Escherichia coli (E. coli) zero (b) The MCLG...

40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Giardia lamblia zero (2) Viruses zero (3) Legionella zero (4) Total coliforms (including fecal) zero coliforms and Escherichia coli (5) Cryptosporidium zero (6) Escherichia coli (E. coli) zero (b) The MCLG...

Localizing Proteins in Fixed Giardia lamblia and Live Cultured Mammalian Cells by Confocal Fluorescence Microscopy.

PubMed

Nyindodo-Ogari, Lilian; Schwartzbach, Steven D; Skalli, Omar; Estraño, Carlos E

2016-01-01

Confocal fluorescence microscopy and electron microscopy (EM) are complementary methods for studying the intracellular localization of proteins. Confocal fluorescence microscopy provides a rapid and technically simple method to identify the organelle in which a protein localizes but only EM can identify the suborganellular compartment in which that protein is present. Confocal fluorescence microscopy, however, can provide information not obtainable by EM but required to understand the dynamics and interactions of specific proteins. In addition, confocal fluorescence microscopy of cells transfected with a construct encoding a protein of interest fused to a fluorescent protein tag allows live cell studies of the subcellular localization of that protein and the monitoring in real time of its trafficking. Immunostaining methods for confocal fluorescence microscopy are also faster and less involved than those for EM allowing rapid optimization of the antibody dilution needed and a determination of whether protein antigenicity is maintained under fixation conditions used for EM immunogold labeling. This chapter details a method to determine by confocal fluorescence microscopy the intracellular localization of a protein by transfecting the organism of interest, in this case Giardia lamblia, with the cDNA encoding the protein of interest and then processing these organisms for double label immunofluorescence staining after chemical fixation. Also presented is a method to identify the organelle targeting information in the presequence of a precursor protein, in this case the presequence of the precursor to the Euglena light harvesting chlorophyll a/b binding protein of photosystem II precursor (pLHCPII), using live cell imaging of mammalian COS7 cells transiently transfected with a plasmid encoding a pLHCPII presequence fluorescent protein fusion and stained with organelle-specific fluorescent dyes.

An atypical proprotein convertase in Giardia lamblia differentiation.

PubMed

Davids, B J; Gilbert, M A; Liu, Q; Reiner, D S; Smith, A J; Lauwaet, T; Lee, C; McArthur, A G; Gillin, F D

2011-02-01

Proteolytic activity is important in the lifecycles of parasites and their interactions with hosts. Cysteine proteases have been best studied in Giardia, but other protease classes have been implicated in growth and/or differentiation. In this study, we employed bioinformatics to reveal the complete set of putative proteases in the Giardia genome. We identified 73 peptidase homologs distributed over 5 catalytic classes in the genome. Serial analysis of gene expression of the G. lamblia lifecycle found thirteen protease genes with significant transcriptional variation over the lifecycle, with only one serine protease transcript upregulated late in encystation. The translated gene sequence of this encystation-specific transcript was most similar to eukaryotic subtilisin-like proprotein convertases (SPC), although the typical catalytic triad was not identified. Epitope-tagged gSPC protein expressed in Giardia under its own promoter was upregulated during encystation with highest expression in cysts and it localized to encystation-specific secretory vesicles (ESV). Total gSPC from encysting cells produced proteolysis in gelatin gels that co-migrated with the epitope-tagged protease in immunoblots. Immuno-purified gSPC also had gelatinase activity. To test whether endogenous gSPC activity is involved in differentiation, trophozoites and cysts were exposed to the specific serine proteinase inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride hydrochloride (AEBSF). After 21 h encystation, a significant decrease in ESV was observed with 1mM AEBSF and by 42 h the number of cysts was significantly reduced, but trophozoite growth was not inhibited. Concurrently, levels of cyst wall proteins 1 and 2, and AU1-tagged gSPC protein itself were decreased. Excystation of G. muris cysts was also significantly reduced in the presence of AEBSF. These results support the idea that serine protease activity is essential for Giardia encystation and excystation. Copyright © 2010 Elsevier B.V. All rights reserved.

An Atypical Proprotein Convertase in Giardia lamblia Differentiation

PubMed Central

Davids, B. J.; Gilbert, M. A.; Liu, Q.; Reiner, D. S.; Smith, A. J.; Lauwaet, T.; Lee, C.; McArthur, A. G.; Gillin, F. D.

2010-01-01

Proteolytic activity is important in the lifecycles of parasites and their interactions with hosts. Cysteine proteases have been best studied in Giardia, but other protease classes have been implicated in growth and/or differentiation. In this study, we employed bioinformatics to reveal the complete set of putative proteases in the Giardia genome. We identified 73 peptidase homologues distributed over 5 catalytic classes in the genome. Serial analysis of gene expression of the G. lamblia lifecycle found thirteen protease genes with significant transcriptional variation over the lifecycle, with only one serine protease transcript upregulated late in encystation. The translated gene sequence of this encystation-specific transcript was most similar to eukaryotic subtilisin-like proprotein convertases (SPC), although the typical catalytic triad was not identified. Epitope-tagged gSPC protein expressed in Giardia under its own promoter was upregulated during encystation with highest expression in cysts and it localized to encystation-specific secretory vesicles (ESV). Total gSPC from encysting cells produced proteolysis in gelatin gels that co-migrated with the epitope-tagged protease in immunoblots. Immuno-purified gSPC also had gelatinase activity. To test whether endogenous gSPC activity is involved in differentiation, trophozoites and cysts were exposed to the specific serine proteinase inhibitor 4-(2-Aminoethyl)-benzenesulfonyl fluoride hydrochloride (AEBSF). After 21 h encystation, a significant decrease in ESV was observed with 1 mM AEBSF and by 42 h the number of cysts was significantly reduced, but trophozoite growth was not inhibited. Concurrently, levels of cyst wall proteins 1 and 2, and AU1-tagged gSPC protein itself were decreased. Excystation of G. muris cysts was also significantly reduced in the presence of AEBSF. These results support the idea that serine protease activity is essential for Giardia encystation and excystation. PMID:21075147

IL-17A promotes protective IgA responses and expression of other potential effectors against the lumen-dwelling enteric parasite Giardia.

PubMed

Dann, Sara M; Manthey, Carolin F; Le, Christine; Miyamoto, Yukiko; Gima, Lauren; Abrahim, Andrew; Cao, Anthony T; Hanson, Elaine M; Kolls, Jay K; Raz, Eyal; Cong, Yingzi; Eckmann, Lars

2015-09-01

Giardia lamblia is a leading protozoan cause of diarrheal disease worldwide. It colonizes the lumen and epithelial surface of the small intestine, but does not invade the mucosa. Acute infection causes only minimal mucosal inflammation. Effective immune defenses exist, yet their identity and mechanisms remain incompletely understood. Interleukin (IL)-17A has emerged as an important cytokine involved in inflammation and antimicrobial defense against bacterial pathogens at mucosal surfaces. In this study, we demonstrate that IL-17A has a crucial function in host defense against Giardia infection. Using murine infection models with G. muris and G. lamblia, we observed marked and selective induction of intestinal IL-17A with peak expression after 2 weeks. Th17 cells in the lamina propria and innate immune cells in the epithelial compartment of the small intestine were responsible for the IL-17A response. Experiments in gene-targeted mice revealed that the cytokine, and its cognate receptor IL-17RA, were required for eradication of the parasite. The actions of the cytokine were mediated by hematopoietic cells, and were required for the transport of IgA into the intestinal lumen, since IL-17A deficiency led to marked reduction of fecal IgA levels, as well as for increased intestinal expression of several other potential effectors, including β-defensin 1 and resistin-like molecule β. In contrast, intestinal hypermotility, another major antigiardial defense mechanism, was not impacted by IL-17A loss. Taken together, these findings demonstrate that IL-17A and IL-17 receptor signaling are essential for intestinal defense against the important lumen-dwelling intestinal parasite Giardia. Copyright © 2015 Elsevier Inc. All rights reserved.

40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... lamblia zero (2) Viruses zero (3) Legionella zero (4) Total coliforms (including fecal coliforms and Escherichia coli) zero. (5) Cryptosporidium zero. [54 FR 27527, 27566, June 29, 1989; 55 FR 25064, June 19...

40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... lamblia zero (2) Viruses zero (3) Legionella zero (4) Total coliforms (including fecal coliforms and Escherichia coli) zero. (5) Cryptosporidium zero. [54 FR 27527, 27566, June 29, 1989; 55 FR 25064, June 19...

40 CFR 141.52 - Maximum contaminant level goals for microbiological contaminants.

Code of Federal Regulations, 2011 CFR

2011-07-01

... lamblia zero (2) Viruses zero (3) Legionella zero (4) Total coliforms (including fecal coliforms and Escherichia coli) zero. (5) Cryptosporidium zero. [54 FR 27527, 27566, June 29, 1989; 55 FR 25064, June 19...

ADEQUACY OF DISINFECTION FOR CONTROL OF NEWLY RECOGNIZED WATERBORNE PATHOGENS

EPA Science Inventory

Agents recently recognized as causes or potential causes of waterborne outbreaks include pathogenic bacteria (Campylobacter jejuni, Yersinia enterocoliticia), viruses (rotavirus, Norwalk virus and other poorly defined viral agents) and Giardia lamblia, a protozoan agent. Although...

Antiprotozoal activities of benzimidazoles and correlations with beta-tubulin sequence.

PubMed Central

Katiyar, S K; Gordon, V R; McLaughlin, G L; Edlind, T D

1994-01-01

Benzimidazoles have been widely used since the 1960s as anthelmintic agents in veterinary and human medicine and as antifungal agents in agriculture. More recently, selected benzimidazole derivatives were shown to be active in vitro against two protozoan parasites, Trichomonas vaginalis and Giardia lamblia, and clinical studies with AIDS patients have suggested that microsporidia are susceptible as well. Here, we first present in vitro susceptibility data for T. vaginalis and G. lamblia using an expanded set of benzimidazole derivatives. Both parasites were highly susceptible to four derivatives, including mebendazole, flubendazole, and fenbendazole (50% inhibitory concentrations of 0.005 to 0.16 microgram/ml). These derivatives also had lethal activity that was time dependent: 90% of T. vaginalis cells failed to recover following a 20-h exposure to mebendazole at 0.17 microgram/ml. G. lamblia, but not T. vaginalis, was highly susceptible to five additional derivatives. Next, we examined in vitro activity of benzimidazoles against additional protozoan parasites: little or no activity was observed against Entamoeba histolytica, Leishmania major, and Acanthamoeba polyphaga. Since the microtubule protein beta-tubulin has been identified as the benzimidazole target in helminths and fungi, potential correlations between benzimidazole activity and beta-tubulin sequence were examined. This analysis included partial sequences (residues 108 to 259) from the organisms mentioned above, as well as the microsporidia Encephalitozoon hellem and Encephalitozoon cuniculi and the sporozoan Cryptosporidium parvum. beta-tubulin residues Glu-198 and, in particular, Phe-200 are strong predictors of benzimidazole susceptibility; both are present in Encephalitozoon spp. but absent in C. parvum. PMID:7811023

Click Chemistry-Facilitated Structural Diversification of Nitrothiazoles, Nitrofurans, and Nitropyrroles Enhances Antimicrobial Activity against Giardia lamblia

PubMed Central

Kim, Wan Jung; Korthals, Keith A.; Li, Suhua; Le, Christine; Kalisiak, Jarosław; Sharpless, K. Barry; Fokin, Valery V.; Miyamoto, Yukiko

2017-01-01

ABSTRACT Giardia lamblia is an important and ubiquitous cause of diarrheal disease. The primary agents in the treatment of giardiasis are nitroheterocyclic drugs, particularly the imidazoles metronidazole and tinidazole and the thiazole nitazoxanide. Although these drugs are generally effective, treatment failures occur in up to 20% of cases, and resistance has been demonstrated in vivo and in vitro. Prior work had suggested that side chain modifications of the imidazole core can lead to new effective 5-nitroimidazole drugs that can combat nitro drug resistance, but the full potential of nitroheterocycles other than imidazole to yield effective new antigiardial agents has not been explored. Here, we generated derivatives of two clinically utilized nitroheterocycles, nitrothiazole and nitrofuran, as well as a third heterocycle, nitropyrrole, which is related to nitroimidazole but has not been systematically investigated as an antimicrobial drug scaffold. Click chemistry was employed to synthesize 442 novel nitroheterocyclic compounds with extensive side chain modifications. Screening of this library against representative G. lamblia strains showed a wide spectrum of in vitro activities, with many of the compounds exhibiting superior activity relative to reference drugs and several showing >100-fold increase in potency and the ability to overcome existing forms of metronidazole resistance. The majority of new compounds displayed no cytotoxicity against human cells, and several compounds were orally active against murine giardiasis in vivo. These findings provide additional impetus for the systematic development of nitroheterocyclic compounds with nonimidazole cores as alternative and improved agents for the treatment of giardiasis and potentially other infectious agents. PMID:28396548

In vitro anti-Giardia lamblia activity of 2-aryl-3-hydroxymethyl imidazo[1,2-a]pyridines and -pyrimidines, individually and in combination with albendazole.

PubMed

Velázquez-Olvera, Stephanía; Salgado-Zamora, Héctor; Jiménez-Cardoso, Enedina; Campos-Aldrete, Maria-Elena; Pérez-González, Cuauhtémoc; Ben Hadda, Taibi

2016-03-01

Giardiasis is a major diarrheal disease found throughout the world, the causative agent being the flagellate protozoan Giardia intestinalis. Infection is more common in children than in adults. The appearance of drug resistance has complicated the treatment of several parasitic diseases, including giardiasis. Thus, the aim of this investigation was to make an in vitro evaluation of the antigiardia response of synthetic derivatives 2-aryl-3-hydroxymethylimidazo[1,2-a]pyridines 1 and -pyrimidines 2 against trophozoites of Giardia lamblia WB, in comparison with the reference drug, albendazole. Additionally, the synergistic action of albendazole in combination with each of the most active 2-aryl-3-hydroxymethyl imidazo[1,2-a]pyridines and pyrimidines was also assessed. Based on the IC50 values obtained, the best anti-Giardia activity was provided by the 3-hydroxymethyl-4-fluorophenylimidazo[1,2-a]pyrimidine derivative 2c and the corresponding imidazo[1,2-a]pyrimidine with the p-tolyl substituent 2d, followed by 2a and 2b. These four compounds showed effectiveness at a concentration similar to that of albendazole. Regarding synergism, the IC50 of the combination of albendazole with 2a, 2b or 2c gave the best anti-Giardia action, showing greater efficacy than albendazole alone. Hence, G. lamblia WB showed high susceptibility to some 2-aryl-3-hydroxymethyl imidazo[1,2-a] pyrimidines, which acted synergistically when used in combination with albendazole. Copyright © 2015 Elsevier B.V. All rights reserved.

Click Chemistry-Facilitated Structural Diversification of Nitrothiazoles, Nitrofurans, and Nitropyrroles Enhances Antimicrobial Activity against Giardia lamblia.

PubMed

Kim, Wan Jung; Korthals, Keith A; Li, Suhua; Le, Christine; Kalisiak, Jarosław; Sharpless, K Barry; Fokin, Valery V; Miyamoto, Yukiko; Eckmann, Lars

2017-06-01

Giardia lamblia is an important and ubiquitous cause of diarrheal disease. The primary agents in the treatment of giardiasis are nitroheterocyclic drugs, particularly the imidazoles metronidazole and tinidazole and the thiazole nitazoxanide. Although these drugs are generally effective, treatment failures occur in up to 20% of cases, and resistance has been demonstrated in vivo and in vitro Prior work had suggested that side chain modifications of the imidazole core can lead to new effective 5-nitroimidazole drugs that can combat nitro drug resistance, but the full potential of nitroheterocycles other than imidazole to yield effective new antigiardial agents has not been explored. Here, we generated derivatives of two clinically utilized nitroheterocycles, nitrothiazole and nitrofuran, as well as a third heterocycle, nitropyrrole, which is related to nitroimidazole but has not been systematically investigated as an antimicrobial drug scaffold. Click chemistry was employed to synthesize 442 novel nitroheterocyclic compounds with extensive side chain modifications. Screening of this library against representative G. lamblia strains showed a wide spectrum of in vitro activities, with many of the compounds exhibiting superior activity relative to reference drugs and several showing >100-fold increase in potency and the ability to overcome existing forms of metronidazole resistance. The majority of new compounds displayed no cytotoxicity against human cells, and several compounds were orally active against murine giardiasis in vivo These findings provide additional impetus for the systematic development of nitroheterocyclic compounds with nonimidazole cores as alternative and improved agents for the treatment of giardiasis and potentially other infectious agents. Copyright © 2017 American Society for Microbiology.

MALDI-MIS INVESTIGATIONS OF DRINKING WATER PATHOGENS--GIARDIA AND CRYPTOSPORIDIUM

EPA Science Inventory

The protozoan parasites, Cryptosporidium parvum and Giardia lamblia, have been responsible for numerous waterborne outbreaks of gastrointestinal illness in the United States. The 1993 cryptosporidiosis outbreak in Milwaukee affected approximately 400,000 people and resulted in o...

METHODS FOR DETECTION OF CRYPTOSPORIDIUM SP. AND GIARDIA SP.

EPA Science Inventory

There have been several waterborne outbreaks of giardiasis caused by infection with Giardia lamblia, and cryptosporidiosis, caused by infection with Cryptosporidium parvum. These outbreaks have created a need to detect these organisms in source and finished drinking water. The pr...

CRITERIA FOR EVALUATION OF PROPOSED PROTOZOAN DETECTION METHODS

EPA Science Inventory

There has been a proliferation of techniques and methods reported for analysis of water samples to determine the presence of the protozoan pathogens Cryptosporidium parvum and Giardia lamblia. Many of the proposed methods are presented as complete procedures, which include sampli...

CRITERIA FOR EVALUATION OF PROPOSED PROTOZOAN DETECTION METHODS.

EPA Science Inventory

There has been a proliferation of techniques and methods reported for analysis of water samples to determine the presence of the protozoan pathogens Cryptosporidium parvum and Giardia lamblia. Many of the proposed methods are presented as complete procedures, which include sampli...

ESTIMATION OF GIARDIA CT VALUES AT HIGH PH FOR THE SURFACE WATER TREATMENT RULE

EPA Science Inventory

The U.S. Environmental Protection Agency currently recommends Ct (disinfectant concentration multiplied by the exposure time) values to achieve required levels of inactivation of Giardia lamblia cysts by different disinfectants including free chlorine. Current guidance covers ina...

SPECIES AND GENUS DIFFERENTIATION OF PARASITES (GIARDIA AND CRYPTOSPORIDIUM) BY MALDI - MASS SPECTROMETRY

EPA Science Inventory

The protozoan parasites, Cryptosporidium parvum and Giardia lamblia, have been responsible for numerous waterborne outbreaks of gastrointestinal illness in the United States. The 1993 cryptosporidiosis outbreak in Milwaukee affected approximately 400,000 people and resulted in o...

Irritable bowel syndrome and chronic fatigue 3 years after acute giardiasis: historic cohort study.

PubMed

Wensaas, Knut-Arne; Langeland, Nina; Hanevik, Kurt; Mørch, Kristine; Eide, Geir Egil; Rortveit, Guri

2012-02-01

Giardia lamblia is a common cause of gastroenteritis worldwide, but there is limited knowledge about the long-term complications. To estimate the relative risk of irritable bowel syndrome (IBS) and chronic fatigue 3 years after acute giardiasis. Controlled historic cohort study with 3 years' follow-up. Data collected by mailed questionnaire. Waterborne outbreak of giardiasis in the city of Bergen, Norway. 817 patients exposed to Giardia lamblia infection verified by detection of cysts in stool samples and 1128 matched controls. IBS and chronic fatigue. The prevalence of IBS in the exposed group was 46.1%, compared with 14.0% in the control group, and the adjusted RR=3.4 (95% CI 2.9 to 3.8). Chronic fatigue was reported by 46.1% of the exposed group and 12.0% of the controls, the adjusted RR was 4.0 (95% CI 3.5 to 4.5). IBS and chronic fatigue were associated and the RR for the exposed group of having a combination of the two outcomes was 6.8 (95% CI 5.3 to 8.5). The RR was also increased for having just one of the two syndromes, 1.8 for IBS (95% CI 1.4 to 2.3) and 2.2 for chronic fatigue (95% CI 1.7 to 2.8). Infection with Giardia lamblia in a non-endemic area was associated with a high prevalence of IBS and chronic fatigue 3 years after acute illness, and the risk was significantly higher than in the control group. This shows that the potential consequences of giardiasis are more serious than previously known. Further studies are needed, especially in areas where giardiasis is endemic.

Epidemiology of Soil-Transmitted Helminth and Intestinal Protozoan Infections in Preschool-Aged Children in the Amhara Region of Ethiopia

PubMed Central

Aiemjoy, Kristen; Gebresillasie, Sintayehu; Stoller, Nicole E.; Shiferaw, Ayalew; Tadesse, Zerihun; Chanyalew, Melsew; Aragie, Solomon; Callahan, Kelly; Keenan, Jeremy D.

2017-01-01

Intestinal parasites are important contributors to global morbidity and mortality and are the second most common cause of outpatient morbidity in Ethiopia. This cross-sectional survey describes the prevalence of soil-transmitted helminths and intestinal protozoa in preschool children 0–5 years of age in seven communities in the Amhara region of Ethiopia, and investigates associations between infection, household water and sanitation characteristics, and child growth. Stool samples were collected from children 0–5 years of age, 1 g of sample was preserved in sodium acetate–acetic acid–formalin, and examined for intestinal helminth eggs and protozoa cysts ether-concentration method. A total of 212 samples were collected from 255 randomly selected children. The prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm were 10.8% (95% confidence interval [CI] 6.6–15.1), 1.4% (95% CI = 0–3.0), and 0% (95% CI = 0–1.7), respectively. The prevalence of the pathogenic intestinal protozoa Giardia lamblia and Entamoeba histolytica/dispar were 10.4% (95% CI = 6.2–14.6) and 3.3% (95% CI = 0.09–5.7), respectively. Children with A. lumbricoides infections had lower height-for-age z-scores compared with those without, but were not more likely to have stunting. Compared with those without G. lamblia, children with G. lamblia infections had lower weight-for-age and weight-for-height z-scores and were more than five times as likely to meet the z-score definition for wasting (prevalence ratio = 5.42, 95% CI = 2.97–9.89). This article adds to a growing body of research on child growth and intestinal parasitic infections and has implications for their treatment and prevention in preschool-aged children. PMID:28167597

Epidemiology of Soil-Transmitted Helminth and Intestinal Protozoan Infections in Preschool-Aged Children in the Amhara Region of Ethiopia.

PubMed

Aiemjoy, Kristen; Gebresillasie, Sintayehu; Stoller, Nicole E; Shiferaw, Ayalew; Tadesse, Zerihun; Chanyalew, Melsew; Aragie, Solomon; Callahan, Kelly; Keenan, Jeremy D

2017-04-01

AbstractIntestinal parasites are important contributors to global morbidity and mortality and are the second most common cause of outpatient morbidity in Ethiopia. This cross-sectional survey describes the prevalence of soil-transmitted helminths and intestinal protozoa in preschool children 0-5 years of age in seven communities in the Amhara region of Ethiopia, and investigates associations between infection, household water and sanitation characteristics, and child growth. Stool samples were collected from children 0-5 years of age, 1 g of sample was preserved in sodium acetate-acetic acid-formalin, and examined for intestinal helminth eggs and protozoa cysts ether-concentration method. A total of 212 samples were collected from 255 randomly selected children. The prevalence of Ascaris lumbricoides , Trichuris trichiura , and hookworm were 10.8% (95% confidence interval [CI] 6.6-15.1), 1.4% (95% CI = 0-3.0), and 0% (95% CI = 0-1.7), respectively. The prevalence of the pathogenic intestinal protozoa Giardia lamblia and Entamoeba histolytica / dispar were 10.4% (95% CI = 6.2-14.6) and 3.3% (95% CI = 0.09-5.7), respectively. Children with A. lumbricoides infections had lower height-for-age z -scores compared with those without, but were not more likely to have stunting. Compared with those without G. lamblia , children with G. lamblia infections had lower weight-for-age and weight-for-height z -scores and were more than five times as likely to meet the z -score definition for wasting (prevalence ratio = 5.42, 95% CI = 2.97-9.89). This article adds to a growing body of research on child growth and intestinal parasitic infections and has implications for their treatment and prevention in preschool-aged children.

Identification of a nicotinamide/nicotinate mononucleotide adenylyltransferase in Giardia lamblia (GlNMNAT).

PubMed

Forero-Baena, Nicolás; Sánchez-Lancheros, Diana; Buitrago, July Constanza; Bustos, Victor; Ramírez-Hernández, María Helena

2015-01-01

Giardia lamblia is an intestinal protozoan parasite that causes giardiasis, a disease of high prevalence in Latin America, Asia and Africa. Giardiasis leads to poor absorption of nutrients, severe electrolyte loss and growth retardation. In addition to its clinical importance, this parasite is of special biological interest due to its basal evolutionary position and simplified metabolism, which has not been studied thoroughly. One of the most important and conserved metabolic pathways is the biosynthesis of nicotinamide adenine dinucleotide (NAD). This molecule is widely known as a coenzyme in multiple redox reactions and as a substrate in cellular processes such as synthesis of Ca 2+ mobilizing agents, DNA repair and gene expression regulation. There are two pathways for NAD biosynthesis, which converge at the step catalyzed by nicotinamide/nicotinate mononucleotide adenylyltransferase (NMNAT, EC 2.7.7.1/18). Using bioinformatics tools, we found two NMNAT sequences in Giardia lamblia ( glnmnat-a and glnmnat-b ). We first verified the identity of the sequences in silico . Subsequently, glnmnat-a was cloned into an expression vector. The recombinant protein (His-GlNMNAT) was purified by nickel-affinity binding and was used in direct in vitro enzyme assays assessed by C18-HPLC, verifying adenylyltransferase activity with both nicotinamide (NMN) and nicotinic acid (NAMN) mononucleotides. Optimal reaction pH and temperature were 7.3 and 26 °C. Michaelis-Menten kinetics were observed for NMN and ATP, but saturation was not accomplished with NAMN, implying low affinity yet detectable activity with this substrate. Double-reciprocal plots showed no cooperativity for this enzyme. This represents an advance in the study of NAD metabolism in Giardia spp.

DO AUTOCHTHONOUS BACTERIA AFFECT GIARDIA CYST SURVIVAL IN NATURAL WATERS?

EPA Science Inventory

Giardia lamblia survives in and is transmitted to susceptible human and animal populations via water, where it is present in an environmentally resistant cyst form. Previous research has highlighted the importance of water temperature in cyst survival, and has also suggested the ...

ANTIPROTOZOAL ACTIVITY OF EXTRACTS OF ELAEODENDRON TRICHOTOMUM (CELASTRACEAE).

PubMed

Roca-Mézquita, Carolina; Graniel-Sabido, Manlio; Moo-Puc, Rosa E; Leon-Déniz, Lorena V; Gamboa-León, Rubí; Arjona-Ruiz, Carely; Tun-Garrido, Juan; Mirón-López, Gumersindo; Mena-Rejón, Gonzalo J

2016-01-01

Chagas disease, amebiasis, giardiasis and trichomoniasis represent a serious health problem in Latin America. The drugs employed to treat these illnesses produce important side effects and resistant strains have appeared. The present study was aimed to evaluate the antiprotozoal activity of leaves, stem bark and root bark of Elaeodendron trichotomum , a celastraceus, that is used in Mexico as an anti-infective in febrile-type diseases. Dichloromethane and methanol extracts of leaves, bark and roots of Elaeodendron trichotomum were tested against Entamoeba histolytica , Giardia lamblia , Trichomonas vaginalis , and Trypanosoma cruzi . A quantitative HPLC analysis of pristimerin and tingenone was performed. The dichloromethane extract of roots was active against E. histolytica , G. lamblia , T. vaginalis , and T. cruzi , at IC50's of 0.80, 0.44, 0.46, and 2.68 μg/mL, respectively. The HPLC analysis revealed the presence of tingenone (3.84%) and pristimerin (0.14%). The dichloromethane extract of the roots bark showed significant activity against all screened protozoa.

ANTIPROTOZOAL ACTIVITY OF EXTRACTS OF ELAEODENDRON TRICHOTOMUM (CELASTRACEAE)

PubMed Central

Roca-Mézquita, Carolina; Graniel-Sabido, Manlio; Moo-Puc, Rosa E.; Leon-Déniz, Lorena V.; Gamboa-León, Rubí; Arjona-Ruiz, Carely; Tun-Garrido, Juan; Mirón-López, Gumersindo; Mena-Rejón, Gonzalo J.

2016-01-01

Background: Chagas disease, amebiasis, giardiasis and trichomoniasis represent a serious health problem in Latin America. The drugs employed to treat these illnesses produce important side effects and resistant strains have appeared. The present study was aimed to evaluate the antiprotozoal activity of leaves, stem bark and root bark of Elaeodendron trichotomum, a celastraceus, that is used in Mexico as an anti-infective in febrile-type diseases. Materials and methods: Dichloromethane and methanol extracts of leaves, bark and roots of Elaeodendron trichotomum were tested against Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis, and Trypanosoma cruzi. A quantitative HPLC analysis of pristimerin and tingenone was performed. Results: The dichloromethane extract of roots was active against E. histolytica, G. lamblia, T. vaginalis, and T. cruzi, at IC50’s of 0.80, 0.44, 0.46, and 2.68 μg/mL, respectively. The HPLC analysis revealed the presence of tingenone (3.84%) and pristimerin (0.14%). Conclusions: The dichloromethane extract of the roots bark showed significant activity against all screened protozoa. PMID:28852732

[The prevalence of intestinal parasitism in native villages of the Tembé tribe, the Brazilian eastern Amazon].

PubMed

Miranda, R dos A; Xavier, F B; Nascimento, J R; de Menezes, R C

1999-01-01

To determine the prevalence of intestinal parasitism in the Tembé settlements, parasitological examination was performed in December 1996 in the entire population (93 Indians). Hookworms were found in 29.0%, A. lumbricoides in 34.4%, E. histolytica in 12.9%, and G. lamblia in 4.3% of the individuals. The Turé-Mariquita settlement had the highest prevalence of hookworms and A. lumbricoides, while Acará-Mirim had the highest prevalence of E. histolytica and G. lamblia. No differences in mean age were found between Indians with parasites and Indians without parasites. The association between intestinal parasites and sex was nonsignificant, except for the prevalence of hookworms, which was very high in males (38.6%) compared to females (20.4%). The study showed a high prevalence of some intestinal parasites in the Tembé settlements, indicating that primary and secondary health measures should taken immediately for the prevention of intestinal parasitoses.

Modeling and analysis of propulsion in the multiflagellated micoorganism Giardia lamblia

NASA Astrophysics Data System (ADS)

Lenaghan, Scott C.; Chen, Jun; Zhang, Mingjun

2013-07-01

The goal of this work was to analyze the propulsion of multiflagellated microorganisms, and to draw insight to the underlying physics and biology of the movement. Giardia lamblia was chosen as the model organism due to its unique ability to mechanically attach to various surfaces, its rapid movement, and its fine control over steering and navigation. In this work, a mechanics model was utilized to study the mechanics and propulsive contribution of the ventral and anterior flagella in Giardia. It was discovered that energy is supplied mainly at the proximal portion of these flagella, supporting the hypothesis that a decreasing adenosine triphosphate (ATP) gradient along the length of the flagella would not affect the motion observed. Similarly, the elasticity of the flagella allows the energy input at the proximal portion to be transferred to the distal portion, where the majority of thrust is generated. Specifically, we found that the ventral flagella are the driving force for planar propulsion and turning, while the anterior flagella are used for steering and control.

Label-free detection and identification of waterborne parasites using a microfluidic multi-angle laser scattering system

NASA Astrophysics Data System (ADS)

Huang, Wei; Yang, Limei; Lei, Lei; Li, Feng

2017-10-01

A microfluidic-based multi-angle laser scattering (MALS) system capable of acquiring scattering patterns of a single particle is designed and demonstrated. The system includes a sheathless nozzle microfluidic glass chip, and an on-chip MALS unit being in alignment with the nozzle exit in the chip. The size and relative refractive indices (RI) of polystyrene (PS) microspheres were deduced with accuracies of 60 nm and 0.002 by comparing the experimental scattering patterns with theoretical ones. We measured scattering patterns of waterborne parasites i.e., Cryptosporidium parvum (C.parvum) and Giardia lamblia (G. lamblia), and some other representative species suspended in deionized water at a maximum flow rate of 12 μL/min, and a maximum of 3000 waterborne parasites can be identified within one minute with a mean accuracy higher than 96% by classification of distinctive scattering patterns using a support-vector-machine (SVM) algorithm. The system provides a promising tool for label-free detection of waterborne parasites and other biological contaminants.

In vitro antiprotozoal activity of the leaves of Artemisia ludoviciana.

PubMed

Said Fernández, Salvador; Ramos Guerra, Monica Celina; Mata Cárdenas, Benito David; Vargas Villarreal, Javier; Villarreal Treviño, Licet

2005-07-01

The inhabitants of Northeast of Mexico use an infusion of leaves from Artemisia ludoviciana as an antidiarrheal remedy. The aqueous, methanol, acetone and hexane leaf extracts from mature plants were found to be active in vitro against the parasitic protozoa Entamoeba histolytica and Giardia lamblia.

Studies of Giardia lamblia

DTIC Science & Technology

1994-10-05

isoenzyme analysis of 19 axenic strains isolated from symptomatic and asymptomatic patients in Mexico . Trans. R. Soc. Trop. Med. Hyg. 83 : 644-646...antibody studies with agents of Varicella and Herpes Zoster propagated in vitro. Proe. Soc. Exptl. BioI. Med . 86 :7 89-794. Woo, P. and G.S. Panayi

The efficacy of potassium ferrate as a chemical disinfectant on E. coli, Vibrio cholera, human adenovirus, and Giardia lamblia

EPA Science Inventory

Introduction: Drinking water and wastewater go through numerous treatments to remove microorganisms and other contaminants one of many processes along the treatment train is disinfection. There are different ways to disinfect these waters, however to date the most common disinf...

Lensfree microscopy on a cellphone

PubMed Central

Tseng, Derek; Mudanyali, Onur; Oztoprak, Cetin; Isikman, Serhan O.; Sencan, Ikbal; Yaglidere, Oguzhan; Ozcan, Aydogan

2010-01-01

We demonstrate lensfree digital microscopy on a cellphone. This compact and light-weight holographic microscope installed on a cellphone does not utilize any lenses, lasers or other bulky optical components and it may offer a cost-effective tool for telemedicine applications to address various global health challenges. Weighing ~38 grams (<1.4 ounces), this lensfree imaging platform can be mechanically attached to the camera unit of a cellphone where the samples are loaded from the side, and are vertically illuminated by a simple light-emitting diode (LED). This incoherent LED light is then scattered from each micro-object to coherently interfere with the background light, creating the lensfree hologram of each object on the detector array of the cellphone. These holographic signatures captured by the cellphone permit reconstruction of microscopic images of the objects through rapid digital processing. We report the performance of this lensfree cellphone microscope by imaging various sized micro-particles, as well as red blood cells, white blood cells, platelets and a waterborne parasite (Giardia lamblia). PMID:20445943

A HISTORICAL PERSPECTIVE OF DETECTION METHODS FOR GIARDIA CYSTS AND CRYPTOSPORIDIUM OOCYSTS IN WATER

EPA Science Inventory

In the mid-20th century Giardia was classified as a non-pathogenic commensal organism and Cryptosporidium was not recognized yet. However as early as 1946 a waterborne outbreak of giardiasis was suspected. From 1965 to 1979 it became clear that Giardia lamblia was indeed a human ...

The efficacy of potassium ferrate as a chemical disinfectant on E. coli, Vibrio cholera, human adenovirus, and Giardia lamblia - Abstract

EPA Science Inventory

Introduction: Drinking water and wastewater effluents go through numerous treatments to remove microorganisms and other contaminants in the United States. One of many processes along the treatment train is disinfection, and to date the most common disinfectants still remain chemi...

THz+X Seedling Report

DTIC Science & Technology

2005-11-23

lamblia Entamoeba histolytica Toxoplasma Microsporidia Additional viral encephalitides West Nile Virus LaCrosse California encephalitis VEE...Is Catalyzed by Salicylate 1- Monooxygenase from Pseudomonas sp . Strain ATCC 29352; Applied and Environmental Microbiology, July 2004, p. 4040-4047...the Mechanism of RDX Biodegradation by Rhodococcus - 31 - sp . Strain DN22; Applied and Environmental Microbiology, March 2003, p. 1347-1351

MATRIX ASSISTED LASER DESORPTION/IONIZATION TIME OF FLIGHT MASS SPECTROMETRY BASED ANALYSIS OF GIARDIA LAMBLIA

EPA Science Inventory

Giardia is the protozoan parasite that is the etiologic agent of giardiasis. This illness is the most common parasitic disease, estimated to infect 2.5 million people in the United States and up to 280 million people worldwide each year [8,19]. Symptoms of giardiasis range from ...

Structure-activity studies of dicationically substituted bis-benzimidazoles against Giardia lamblia: correlation of antigiardial activity with DNA binding affinity and giardial topoisomerase II inhibition.

PubMed Central

Bell, C A; Dykstra, C C; Naiman, N A; Cory, M; Fairley, T A; Tidwell, R R

1993-01-01

Nine dicationically substituted bis-benzimidazoles were examined for their in vitro activities against Giardia lamblia WB (ATCC 30957). The potential mechanisms of action of these compounds were evaluated by investigating the relationship among in vitro antigiardial activity and the affinity of the molecules for DNA and their ability to inhibit the activity of giardial topoisomerase II. Each compound demonstrated antigiardial activity, as measured by assessing the incorporation of [methyl-3H]thymidine by giardial trophozoites exposed to the test agents. Three compounds exhibited excellent in vitro antigiardial activities, with 50% inhibitory concentrations which compared very favorably with those of two currently used drugs, quinacrine HCl and metronidazole. Putative mechanisms of action for these compounds were suggested by the strong correlation observed among in vitro antigiardial activity and the affinity of the molecules for natural and synthetic DNA and their ability to inhibit the relaxation activity of giardial topoisomerase II. A strong correlation between the DNA binding affinity of these compounds and their inhibition of giardial topoisomerase II activity was also observed. Images PMID:8109934

Anti-Giardia activity of Syzygium aromaticum essential oil and eugenol: effects on growth, viability, adherence and ultrastructure.

PubMed

Machado, M; Dinis, A M; Salgueiro, L; Custódio, José B A; Cavaleiro, C; Sousa, M C

2011-04-01

The present work evaluates the anti-Giardia activity of Syzygium aromaticum and its major compound eugenol. The effects were evaluated on parasite growth, adherence, viability and ultrastructure. S. aromaticum essential oil (IC(50)=134 μg/ml) and eugenol (IC(50)=101 μg/ml) inhibited the growth of G. lamblia. The essential oil inhibited trophozoites adherence since the first hour of incubation and was able to kill almost 50% of the parasites population in a time dependent manner. The eugenol inhibited G. lamblia trophozoites adherence since the third hour and not induce cell lyses. The main morphological alterations were modifications on the cell shape, presence of precipitates in the cytoplasm, autophagic vesicles, internalization of flagella and ventral disc, membrane blebs, and intracellular and nuclear clearing. Taken together, our findings lead us to propose that eugenol was responsible for the anti-giardial activity of the S. aromaticum essential oil and both have potential for use as therapeutic agents against giardiasis. Copyright © 2011 Elsevier Inc. All rights reserved.

[Knowledge, perceptions and practice of dermatologists with respect to Giardia lamblia infection].

PubMed

Iglesias Hernández, Tania; Almannoni, Saleh Ali; Rodríguez, Maria Elena; Sánchez Valdés, Lizet; Pupo, Deisy Martín; Manzur Katrib, Julián; Fonte Galindo, Luis

2010-01-01

to ascertain the level of knowledge, the perceptions and practice of dermatologists in the City of Havana with respect to Giardia lamblia infection. with prior informed consent given by the dermatologists from the City of Havana, 50 dermatologists- a number very close to the universe of these experts in the province- were administered a survey of their knowledge, perceptions and practice about this parasitosis. The survey was prepared in 4 phases; that is, interviews to physicians on diagnosis, treatment and control of giardiasis; drafting of a preliminary questionnaire based on the interview results; submission of this instruments to the experts, and finally its validation through its application to a small group of physicians. it was evinced that the dermatologists in the City of Havana had poor knowledge about giardiasis, particularly its cutaneous manifestations (out of 19 questions on cognitive aspects, the correct answer mean was 10,18), inadequate perceptions on this disease and practice was not good. with the aim of mitigating these difficulties, some academic intervention is needed to make emphasis on the formative aspects related to parasitic diseases in general and giardiasis in particular

Drinking water system treatment and contamination in Shatila Refugee Camp in Beirut, Lebanon.

PubMed

Khoury, S; Graczyk, T; Burnham, G; Jurdi, M; Goldman, L

2016-11-02

Drinking water at Shatila Palestinian Refugee Camp in Beirut, Lebanon is of poor quality and unpredictably intermittent quantity. We aimed to characterize drinking water sources and contamination at Shatila and determine how drinking water can be managed to reduce community health burdens. We interviewed the Popular Committee, well owners, water vendors, water shopkeepers and preschool administrators about drinking water sources, treatment methods and the population served. Water samples from the sources and intermediaries were analysed for thermotolerant faecal coliforms (FCs), Giardia lamblia, Cryptosporidium parvum and microsporidia, using immunofluorescent antibody detection for G. lamblia and C. parvum, and chromotrope-2 stain for microsporidia. All drinking water sources were contaminated with FCs and parasites. FC counts (cfu/mL) were as follows: wells (35-300), water vendors (2-178), shops (30-300) and preschools (230-300). Responsible factors identified included: unskilled operators; improper maintenance of wells and equipment; lack of proper water storage and handling; and misperception of water quality. These factors must be addressed to improve water quality at Shatila and other refugee camps.

Prevalence and impact of water-borne zoonotic pathogens in water, cattle and humans in selected villages in Dodoma Rural and Bagamoyo districts, Tanzania

NASA Astrophysics Data System (ADS)

Kusiluka, L. J. M.; Karimuribo, E. D.; Mdegela, R. H.; Luoga, E. J.; Munishi, P. K. T.; Mlozi, M. R. S.; Kambarage, D. M.

A study on the prevalence of water-borne zoonotic pathogens in water, cattle and humans was conducted in six villages in Dodoma Rural (5) and Bagamoyo (1) districts, Tanzania. Water sources were screened for faecal coliform organisms, thermophilic Campylobacter, Salmonella, Cryptosporidium and Giardia. Faecal samples from cattle and humans were also analysed for the above specific pathogens. Results indicate that 70.8% ( n = 48) of the water sources screened were contaminated with faecal coliform organisms. Water sources in two villages, one each in Dodoma Rural and Bagamoyo districts were also contaminated with Giardia lamblia. The overall prevalence of Campylobacter jejuni in cattle in the two study areas was 2.3% ( n = 942) and at least one animal in each village was infected with C. jejuni. Cryptosporidium parvum was detected in 0.5% ( n = 942) of the cattle examined in three villages in Dodoma district. Salmonella spp. was demonstrated in only 1.4% ( n = 144) of the cattle in Chalinze village in Dodoma Rural district while G. lamblia was only detected in 1.5% ( n = 202) of the animals examined in Chamakweza village in Bagamoyo district. Nine (1.9%) of the people screened at three heath centres in the study areas were infected with C. jejuni while 3.7% ( n = 484) of the people had C. parvum oocysts. G. lamblia was detected in 2.5% of the 202 people screened at the Chalinze health centre in Bagamoyo district. Analysis of the secondary data revealed that clinical complaints related to enteric diseases were prevalent in humans in the two areas throughout the year and the prevalence varied from about 1% to 25% in both <5 years and ⩾5 years patients. In conclusion, this study has highlighted the possible public health risks, which may be associated with keeping of animals and sharing of water sources between humans and animals.

Sedimentation of Free and Attached Cryptosporidium Oocysts and Giardia Cysts in Water

PubMed Central

Medema, G. J.; Schets, F. M.; Teunis, P. F. M.; Havelaar, A. H.

1998-01-01

Experimental analysis of the sedimentation velocity of Cryptosporidium parvum oocysts and Giardia lamblia cysts was compared with mathematical description of their sedimentation velocities by using measurements of (oo)cyst size and density and the density and viscosity of the sedimentation medium to determine if the sedimentation kinetics of freely suspended oocysts of C. parvum and cysts of G. lamblia can be described by Stokes’ law. The theoretically calculated sedimentation kinetics showed a good agreement with the experimentally observed kinetics. Both showed a decline in sedimentation velocity over time, caused primarily by variation in (oo)cyst density. The initial apparent sedimentation velocities in Hanks balanced salt solution at 23°C was 0.35 μm · s−1 for oocysts and 1.4 μm · s−1 for cysts. (Oo)cysts that enter the surface water environment by discharges of biologically treated sewage may be attached to sewage particles, and this will affect their sedimentation kinetics. Therefore, (oo)cysts were mixed with settled secondary effluent. (Oo)cysts readily attached to the (biological) particles in effluent; 30% of both cysts and oocysts attached during the first minutes of mixing, and this fraction increased to approximately 75% after 24 h. The sedimentation velocity of (oo)cysts attached to secondary effluent particles increased with particle size and was (already in the smallest size fraction [1 to 40 μm]) determined by the sedimentation kinetics of the effluent particles. The observed sedimentation velocities of freely suspended (oo)cysts are probably too low to cause significant sedimentation in surface water or reservoirs. However, since a significant proportion of both cysts and oocysts attached readily to organic biological particles in secondary effluent, sedimentation of attached (oo)cysts after discharge into surface water will probably be a significant factor in the environmental ecology of C. parvum and G. lamblia. Attachment to particles influences not only sedimentation of (oo)cysts in surface water but also their behavior in drinking water treatment processes. PMID:9797307

Modelling pathogen log10 reduction values achieved by activated sludge treatment using naïve and semi naïve Bayes network models.

PubMed

Carvajal, Guido; Roser, David J; Sisson, Scott A; Keegan, Alexandra; Khan, Stuart J

2015-11-15

Risk management for wastewater treatment and reuse have led to growing interest in understanding and optimising pathogen reduction during biological treatment processes. However, modelling pathogen reduction is often limited by poor characterization of the relationships between variables and incomplete knowledge of removal mechanisms. The aim of this paper was to assess the applicability of Bayesian belief network models to represent associations between pathogen reduction, and operating conditions and monitoring parameters and predict AS performance. Naïve Bayes and semi-naïve Bayes networks were constructed from an activated sludge dataset including operating and monitoring parameters, and removal efficiencies for two pathogens (native Giardia lamblia and seeded Cryptosporidium parvum) and five native microbial indicators (F-RNA bacteriophage, Clostridium perfringens, Escherichia coli, coliforms and enterococci). First we defined the Bayesian network structures for the two pathogen log10 reduction values (LRVs) class nodes discretized into two states (< and ≥ 1 LRV) using two different learning algorithms. Eight metrics, such as Prediction Accuracy (PA) and Area Under the receiver operating Curve (AUC), provided a comparison of model prediction performance, certainty and goodness of fit. This comparison was used to select the optimum models. The optimum Tree Augmented naïve models predicted removal efficiency with high AUC when all system parameters were used simultaneously (AUCs for C. parvum and G. lamblia LRVs of 0.95 and 0.87 respectively). However, metrics for individual system parameters showed only the C. parvum model was reliable. By contrast individual parameters for G. lamblia LRV prediction typically obtained low AUC scores (AUC < 0.81). Useful predictors for C. parvum LRV included solids retention time, turbidity and total coliform LRV. The methodology developed appears applicable for predicting pathogen removal efficiency in water treatment systems generally. Copyright © 2015 Elsevier Ltd. All rights reserved.

Apyretic gastrointestinal disorders due to giardiasis contracted in Morocco

PubMed Central

Meunier, Yann A.; Hole, Michael K.

2011-01-01

We present the case of a 32-year-old French man who presented with morning nausea, bloating, frequent flatulence, burping, occasional pyrosis, and alternating diarrhea and constipation two weeks after a trip to Morocco. The diagnosis was established by a parasitological stool exam that revealed cysts of Giardia lamblia. He was successfully treated with tinidazole. PMID:24765301

Human Enteropathogen Load in Activated Sewage Sludge and Corresponding Sewage Sludge End Products▿

PubMed Central

Graczyk, Thaddeus K.; Lucy, Frances E.; Tamang, Leena; Miraflor, Allen

2007-01-01

This study demonstrated a significant reduction in the concentrations of Cryptosporidium parvum and Cryptosporidium hominis oocysts, Giardia lamblia cysts, and spores of human-virulent microsporidia in dewatered and biologically stabilized sewage sludge cake end products compared to those of the respective pathogens in the corresponding samples collected during the sludge activation process. PMID:17277215

Microfluidics for effective concentration and sorting of waterborne protozoan pathogens.

PubMed

Jimenez, M; Bridle, H

2016-07-01

We report on an inertial focussing based microfluidics technology for concentrating waterborne protozoa, achieving a 96% recovery rate of Cryptosporidium parvum and 86% for Giardia lamblia at a throughput (mL/min) capable of replacing centrifugation. The approach can easily be extended to other parasites and also bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

Strategies To Discover the Structural Components of Cyst and Oocyst Walls

PubMed Central

Bushkin, G. Guy; Chatterjee, Aparajita; Robbins, Phillips W.

2013-01-01

Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or mass spectrometry. Structural components include a sugar polysaccharide (chitin for Entamoeba, β-1,3-linked glucose for Toxoplasma, and β-1,3-linked GalNAc for Giardia) and/or acid-fast lipids (Toxoplasma and Cryptosporidium). Because Entamoeba cysts and Toxoplasma oocysts are difficult to obtain, studies of walls of nonhuman pathogens (E. invadens and Eimeria, respectively) accelerate discovery. Biochemical methods to dissect fungal walls work well for cyst and oocyst walls, although the results are often unexpected. For example, echinocandins, which inhibit glucan synthases and kill fungi, arrest the development of oocyst walls and block their release into the intestinal lumen. Candida walls are coated with mannans, while Entamoeba cysts are coated in a dextran-like glucose polymer. Models for cyst and oocyst walls derive from their structural components and organization within the wall. Cyst walls are composed of chitin fibrils and lectins that bind chitin (Entamoeba) or fibrils of the β-1,3-GalNAc polymer and lectins that bind the polymer (Giardia). Oocyst walls of Toxoplasma have two distinct layers that resemble those of fungi (β-1,3-glucan in the inner layer) or mycobacteria (acid-fast lipids in the outer layer). Oocyst walls of Cryptosporidium have a rigid bilayer of acid-fast lipids and inner layer of oocyst wall proteins. PMID:24096907

Case-control study of diarrheal disease etiology in individuals over 5 years in southwest China.

PubMed

Zhang, Shun-Xian; Yang, Chun-Li; Gu, Wen-Peng; Ai, Lin; Serrano, Emmanuel; Yang, Pin; Zhou, Xia; Li, Shi-Zhu; Lv, Shan; Dang, Zhi-Sheng; Chen, Jun-Hu; Hu, Wei; Tian, Li-Guang; Chen, Jia-Xu; Zhou, Xiao-Nong

2016-01-01

Acute diarrhea is one of the major public health problems worldwide. Most of studies on acute diarrhea have been made on infants aged below 5 years and few efforts have been made to identify the etiological agents of acute diarrhea in people over five, especially in China. 271 diarrhea cases and 149 healthy controls over 5 years were recruited from four participating hospitals between June 2014 and July 2015. Each stool specimen was collected to detect a series of enteric pathogens, involving five viruses ( Rotavirus group A, RVA; Norovirus , NoV; Sapovirus , SaV; Astrovirus , As; and Adenovirus , Ad), seven bacteria (diarrheagenic Escherichia coli , DEC; non-typhoidal Salmonella , NTS; Shigella spp.; Vibrio cholera; Vibrio parahaemolyticus ; Aeromonas spp.; and Plesiomonas spp.) and three protozoa ( Cryptosporidium spp., Giardia lamblia, G. lamblia , and Blastocystis hominis, B. hominis ). Standard microbiological and molecular methods were applied to detect these pathogens. Data was analyzed using Chi square, Fisher-exact tests and logistic regressions. The prevalence of at least one enteric pathogen was detected in 29.2% (79/271) acute diarrhea cases and in 12.1% (18/149) in healthy controls ( p  < 0.0001). Enteric viral infections (14.4%) were the most common in patients suffering from acute diarrhea, followed by bacteria (13.7%) and intestinal protozoa (4.8%). DEC (12.5%) was the most common causative agent in diarrhea cases, followed by NoV GII (10.0%), RVA (7.4%) and B. hominis (4.8%). The prevalence of co-infection was statistically higher ( p  = 0.0059) in the case group (7.7%) than in the healthy control (1.3%). RVA-NoV GII (3.0%) was the most common co-infection in symptomatic cases. DEC was the most predominant pathogen in diarrhea cases, but it was largely overlooked because the lack of laboratory capacities. Because of the high prevalence of co-infections, it is recommended the urgent development of alternative laboratory methods to assess polymicrobial infections. Such methodological improvements will result in a better prevention and treatment strategies to control diarrhea illness in China.

Reversible assembly of magnetized particles: Application to water-borne pathogen enumeration

NASA Astrophysics Data System (ADS)

Ramadan, Qasem

2009-12-01

Reversible assembly of magnetized particles and cells has been proposed and implemented. The approach is based on magnetized particles or magnetically labeled cell immobilization in an array of individual particle/cell for optical counting. The device has been tested for few types of magnetic particles and one water-borne pathogen: Giardia Lamblia. An individual particle immobilization efficiency of 92% was achieved.

Ultraviolet Light Disinfection in the Use of Individual Water Purification Devices

DTIC Science & Technology

2006-03-01

adenovirus, Giardia lamblia, Giardia muris , and Cryptosporidium parvum. Adenovirus was evaluated because it is considered the most resistant to...7 reproduce cannot infect and are thereby inactivated. Subsequently, when evaluating UV disinfection capability, Giardia cyst and...0.25 to 20 NTU resulted in a 0.8-log and 0.5-log decrease in inactivation of Cryptosporidium and Giardia , respectively (reference 3). The type of

Regional Disease Vector Ecology Profile East Asia

DTIC Science & Technology

2002-04-01

hepatitis A and E, rotaviruses, and other viral species. Infection with pathogenic protozoa, such as Entamoeba histolytica, Giardia lamblia and...to secretions or blood from infected animals or humans. Medical workers treating patients are at high risk of becoming infected . Clinical symptoms...caused by any of 4 protozoan species in the genus Plasmodium that are transmitted by the bite of an infective female Anopheles mosquito. Clinical symptoms

Regional Disease Vector Ecology Profile: South Central Asia

DTIC Science & Technology

2001-09-01

rotaviruses, and other viral species. Infection with pathogenic protozoa, such as Entamoeba histolytica, Giardia lamblia and Cryptosporidium spp., is...Hyalomma ticks, but most human cases result from exposure to secretions or blood from infected animals or humans. Medical workers treating patients are at...by any of 4 protozoan species in the genus Plasmodium that are transmitted by the bite of an infective female Anopheles mosquito. Clinical symptoms

Antiprotozoal, Antibacterial and Antidiarrheal Properties from the Flowers of Chiranthodendron pentadactylon and Isolated Flavonoids.

PubMed

Calzada, Fernando; Juárez, Teresa; García-Hernández, Normand; Valdes, Miguel; Ávila, Oscar; Mulia, Lilian Yepez; Velázquez, Claudia

2017-01-01

Chiranthodendron pentadactylon Larreat. (Sterculiaceae) is a Mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea. To evaluate in vitro antiprotozoal and antibacterial activities and in vivo antidiarrheal activity from the flowers of C. pentadactylon using the extract, fractions, and major isolated flavonoids. Bioassay-guided fractionation of the methanol extract of C. pentadactylon (MECP) led to the isolation of five flavonoids, tiliroside, astragalin, isoquercitrin, (+)-catechin, and (-)-epicatechin. Antimicrobial activities were tested on two protozoa ( Entamoeba histolytica and Giardia lamblia ) and nine bacterial enteropathogens (two Escherichia coli strains, two Shigella sonnei strains, two Shigella flexneri strains, two Salmonella sp. strains, and Vibrio cholerae ) isolated from feces of children with acute diarrhea or dysentery and resistant to chloramphenicol. Also, antidiarrheal activity was tested on cholera toxin-induced diarrhea in male Balb-c mice. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia ; tiliroside showed moderate antiprotozoal activity against both protozoan. In contrast, in the antibacterial activity, tiliroside was the most potent compound on all microorganisms with minimum inhibitory concentration values less than 0.7 mg/mL. In the case of cholera toxin-induced diarrhea, epicatechin was the most potent flavonoid with IC 50 of 14.7 mg/kg. Epicatechin and tiliroside were the flavonoids responsible for antimicrobial andantidiarrheal activities of C. pentadactylon . Its antiprotozoal, antibacterial, and antidiarrheal properties are in good agreement with the traditional medicinal use of C. pentadactylon for the treatment of infectious diarrhea. Epicatechin was the most potent antiamoebic and antigiardial compound with IC 50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia .Tiliroside showed antibacterial activity against all microorganisms tested with MIC values less than 0.7 mg/mL.Epicatechin was the most potent flavonoid on cholera toxin-induced diarrhea with IC 50 of 14.7 mg/kg. Abbreviations used: MECP: Methanol extract of C. pentadactylon .

Comparative Analysis of the 15.5kD Box C/D snoRNP Core Protein in the Primitive Eukaryote Giardia lamblia Reveals Unique Structural and Functional Features

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

Biswas, Shyamasri; Buhrman, Greg; Gagnon, Keith

2012-07-11

Box C/D ribonucleoproteins (RNP) guide the 2'-O-methylation of targeted nucleotides in archaeal and eukaryotic rRNAs. The archaeal L7Ae and eukaryotic 15.5kD box C/D RNP core protein homologues initiate RNP assembly by recognizing kink-turn (K-turn) motifs. The crystal structure of the 15.5kD core protein from the primitive eukaryote Giardia lamblia is described here to a resolution of 1.8 {angstrom}. The Giardia 15.5kD protein exhibits the typical {alpha}-{beta}-{alpha} sandwich fold exhibited by both archaeal L7Ae and eukaryotic 15.5kD proteins. Characteristic of eukaryotic homologues, the Giardia 15.5kD protein binds the K-turn motif but not the variant K-loop motif. The highly conserved residues ofmore » loop 9, critical for RNA binding, also exhibit conformations similar to those of the human 15.5kD protein when bound to the K-turn motif. However, comparative sequence analysis indicated a distinct evolutionary position between Archaea and Eukarya. Indeed, assessment of the Giardia 15.5kD protein in denaturing experiments demonstrated an intermediate stability in protein structure when compared with that of the eukaryotic mouse 15.5kD and archaeal Methanocaldococcus jannaschii L7Ae proteins. Most notable was the ability of the Giardia 15.5kD protein to assemble in vitro a catalytically active chimeric box C/D RNP utilizing the archaeal M. jannaschii Nop56/58 and fibrillarin core proteins. In contrast, a catalytically competent chimeric RNP could not be assembled using the mouse 15.5kD protein. Collectively, these analyses suggest that the G. lamblia 15.5kD protein occupies a unique position in the evolution of this box C/D RNP core protein retaining structural and functional features characteristic of both archaeal L7Ae and higher eukaryotic 15.5kD homologues.« less

Regional Disease Vector Ecology Profile Central Europe

DTIC Science & Technology

2001-04-01

E, rotaviruses and other viral species. Infection with pathogenic protozoa, such as Entamoeba histolytica, Giardia lamblia and Cryptosporidium spp...Medical workers treating patients are at high risk of becoming infected . Clinical symptoms can be severe, with mortality rates up to 50%. Q fever is...papatasi and 71 P. sergenti are endophilic and follow odor plumes to their hosts. Only females suck blood, but both sexes feed on plant sugars and

Association between parasitic infections and tuberculin skin test results in refugees.

PubMed

Watts, Nathaniel S; Mizinduko, Mucho M; Barnett, Elizabeth D; White, Laura F; Hochberg, Natasha S

Parasitic infections are known to modulate the immune response necessary for controlling Mycobacterium tuberculosis infection. We sought to investigate species-specific effects of parasite infection on M. tuberculosis infection. As part of the Refugee Health Assessment Program, stool examinations and tuberculin skin testing were performed on refugees seen at Boston Medical Center between 1995 and 2012. Tuberculin skin test (TST) and stool examination data were collected for 6669 refugees; 3349 (50.2%) were TST positive (≥10 mm). Among TST-positive subjects, 176 (5.3%) had helminth infections and 1149 (34.3%) protozoa. After adjusting for sex, age, and country of origin, helminth and protozoan infections were not associated with TST-positivity. When species-specific effects were examined, subjects infected with Trichuris trichiura and Giardia lamblia had reduced odds of TST-positivity (adjusted OR [aOR] 0.65 [95%CI 0.44-0.96; p = 0.03] and aOR 0.79 [95%CI 0.65-0.95, p = 0.01], respectively). Our findings suggest that T. trichiura and G. lamblia may provide protection against M. tuberculosis infection. This study adds to a growing body of literature suggesting that immune response modulation and susceptibility to M. tuberculosis infection is parasite species-dependent. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevalence of Intestinal Protozoans among Schoolchildren in Suburban Areas near Yangon, Myanmar.

PubMed

Kim, Min-Jae; Jung, Bong-Kwang; Cho, Jaeeun; Kim, Deok-Gyu; Song, Hyemi; Lee, Keon-Hoon; Cho, Seon; Htoon, Thi Thi; Tin, Htay Htay; Chai, Jong-Yil

2016-06-01

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area.

Prevalence of Intestinal Protozoans among Schoolchildren in Suburban Areas near Yangon, Myanmar

PubMed Central

Kim, Min-Jae; Jung, Bong-Kwang; Cho, Jaeeun; Kim, Deok-Gyu; Song, Hyemi; Lee, Keon-Hoon; Cho, Seon; Htoon, Thi Thi; Tin, Htay Htay; Chai, Jong-Yil

2016-01-01

Although intestinal protozoans are common etiologies of diarrhea, few studies have been conducted in Myanmar. This study planned to investigate the prevalence of Giardia lamblia, Entamoeba coli, Entamoeba histolytica, and Endolimax nana among schoolchildren and their guardians in suburban areas near Yangon, Myanmar. We performed a cross-sectional survey among schoolchildren and their guardians from 7 primary schools in South Dagon and Hlaing Thar Yar districts, Yangon, Myanmar. Stool samples were observed with a microscope after concentration technique and iodine staining. Total 821 stool samples, including 556 from schoolchildren and 265 from guardians, were examined. The median age was 6 years old for schoolchildren and 36 years old for guardians. A 53.1% of the school children and 14.6 % of the guardians were males. The overall prevalence of each intestinal protozoan species was as follows: 3.4% (28/821) for G. lamblia; 3.5% (29/821) for E. coli; 1.2% (10/821) for E. histoytica, and 3.0% for E. nana. This study showed that intestinal protozoans are common in primary schoolchildren and their guardians in suburban areas near Yangon, Myanmar. Health interventions, such as hand washing education, improvement of sanitation, and establishment of water purification systems are urgently needed in this area. PMID:27417092

The Military Efficacy of Individual Water Purification Filters.

DTIC Science & Technology

1990-12-01

criteria. ’t *.;as a.Lso serv ea that the KPF units grew opportunistic Pseudomonas sp . on the oroduct water side of the filters, which could have a...small pathogenic protozoan cysts such as Cryptospor-dium parvum, Giardia lamblia, and Entamoeba coli, from water over the effective use life of the...of heterotrophic bacteria such as Pseudoronas sP , Flavobacterium Sp , and other potentially harmfui organisms inside of the units. Enteric viruses are

Iodine Disinfection in the Use of Individual Water Purification Devices

DTIC Science & Technology

2006-03-01

Effect of Resin Disinfectants-I3 and –I5 on Giardia muris and Giardia lamblia. Applied and Environmental Microbiology, 46(5), 965-969. 24. AWWA... Giardia or Cryptosporidium). Iodine-using IWPDs meeting these standards are considered effective against disease causing bacteria, viruses, and...CT = 65 mg-min/L) for a 2-log inactivation of E. histolytica cysts (references 9 and 10). Another study using Giardia cysts showed CT’s up to 3

Regional Disease Vector Ecology Profile. Southeast Asia

DTIC Science & Technology

2009-06-01

strains of Escherichia coli, hepatitis A and E, rotaviruses, etc. Infection with pathogenic protozoa, such as Entamoeba histolytica, Giardia lamblia and...the genus Plasmodium that are transmitted by the bite of an infective female Anopheles mosquito. Clinical symptoms of malaria vary with the species...some feed only late at night or at dawn. Most anophelines feed on exposed legs, but some may feed on arms, ears or the neck. Infected females tend to

[Infectious diseases among Brazilian preschool children attending daycare centers].

PubMed

Pedraza, Dixis Figueroa; Queiroz, Daiane de; Sales, Márcia Cristina

2014-02-01

The scope of this article is to analyze the prevalence and factors associated with the development of infectious diseases that affect children in daycare centers, namely respiratory infections, diarrheal disease and parasitic infections. Bibliographic research was conducted in the MEDLINE, LILACS and SciELO databases, and observational studies were included. 129 studies were identified, of which 21 were considered relevant to this study, namely two longitudinal and 19 cross-sectional studies. The systematization of the reviewed studies highlighted: i) the presence of intestinal parasites was the main outcome analyzed, followed by respiratory infections; ii) only one study investigated the occurrence of diarrheal disease; iii) the Giardia lamblia was the most prevalent parasitosis; iv) the variables that were most often associated with the development of intestinal parasitosis were child age, family income and maternal education; v) the attendance at daycare centers was a risk factor for intestinal parasites and respiratory infections. Respiratory and parasitic infections are major problems in institutionalized children in daycare centers. The reduction of such diseases involves a complex web of socio-economic, sanitation and daycare center infrastructure aspects.

Molecular appraisal of intestinal parasitic infection in transplant recipients

PubMed Central

Yadav, Pooja; Khalil, Shehla; Mirdha, Bijay Ranjan

2016-01-01

Background & objectives: Diarrhoea is the main clinical manifestation caused by intestinal parasitic infections in patients, with special reference to transplant recipients who require careful consideration to reduce morbidity and mortality. Further, molecular characterization of some important parasites is necessary to delineate the different modes of transmission to consider appropriate management strategies. We undertook this study to investigate the intestinal parasitic infections in transplant recipients with or without diarrhoea, and the genotypes of the isolated parasites were also determined. Methods: Stool samples from 38 transplant recipients comprising 29 post-renal, two liver and seven bone marrow transplant (BMT) recipients presenting with diarrhoea and 50 transplant recipients (42 post-renal transplant, eight BMT) without diarrhoea were examined for the presence of intestinal parasites by light microscopy using wet mount, modified Ziehl–Neelsen staining for intestinal coccidia and modified trichrome staining for microsporidia. Genotypes of Cryptosporidium species were determined by multilocus genotyping using small subunit ribosomal (SSUrRNA), Cryptosporidium oocyst wall protein (COWP) and dihydrofolate reductase (DHFR) as the target genes. Assemblage study for Giardia lamblia was performed using triose phosphate isomerase (TPI) as the target gene. Samples were also screened for bacterial, fungal and viral pathogens. Results: The parasites that were detected included Cryptosporidium species (21%, 8/38), Cystoisospora (Isospora) belli (8%, 3), Cyclospora cayetanensis (5%, 2), G. lamblia (11%, 4), Hymenolepis nana (11%, 4), Strongyloides stercoralis (3%, 1) and Blastocystis hominis (3%, 1). Multilocus genotyping of Cryptosporidium species at SSUrRNA, COWP and DHFR loci could detect four isolates of C. hominis; two of C. parvum, one of mixed genotype and one could not be genotyped. All the C. hominis isolates were detected in adult post-renal transplant (PRT) recipients, whereas the C. parvum isolates included a child with BMT and an adult with PRT. Clostridium difficle, cytomegalovirus and Candida albicans were found in 2, 3 and 2 patients, respectively. Interpretation & conclusions: In the present study, C. hominis was observed as an important parasite causing intestinal infections in transplant recipients. Multilocus genotyping of Cryptosporidium species could detect four isolates of C. hominis; two of C. parvum, one of mixed genotype and one could not be genotyped. Genotyping of G. lamblia revealed that assemblage B was most common. PMID:27934806

Intestinal parasites of the Pacific.

PubMed

Small, Ethan A; Tice, Alan D; Zheng, Xiaotian

2003-10-01

Information about intestinal parasites in Hawaii and the Pacific is not current. We reviewed reports on fecal samples obtained from two laboratories and found recovery rates of 9.3% in Hawaii, 14.2% in Saipan, 18% in Rota and 9.5% in Guam. The most frequently identified parasites were Blastocystis hominis (7.6%), Giardia lamblia (1.2%), and Entamoeba coli (0.7%). Although the incidence and types of organisms have changed with time, physicians in Hawaii should continue looking for intestinal parasites.

Cross-modulation of pathogen-specific pathways enhances malnutrition during enteric co-infection with Giardia lamblia and enteroaggregative Escherichia coli

PubMed Central

Bartelt, Luther A.; Bolick, David T.; Zaenker, Edna I.; Donowitz, Jeffery; Thomas-Beckett, Rose Viguna; Rogala, Allison; Carroll, Ian M.; Swann, Jonathan R.; Guerrant, Richard L.

2017-01-01

Diverse enteropathogen exposures associate with childhood malnutrition. To elucidate mechanistic pathways whereby enteric microbes interact during malnutrition, we used protein deficiency in mice to develop a new model of co-enteropathogen enteropathy. Focusing on common enteropathogens in malnourished children, Giardia lamblia and enteroaggregative Escherichia coli (EAEC), we provide new insights into intersecting pathogen-specific mechanisms that enhance malnutrition. We show for the first time that during protein malnutrition, the intestinal microbiota permits persistent Giardia colonization and simultaneously contributes to growth impairment. Despite signals of intestinal injury, such as IL1α, Giardia-infected mice lack pro-inflammatory intestinal responses, similar to endemic pediatric Giardia infections. Rather, Giardia perturbs microbial host co-metabolites of proteolysis during growth impairment, whereas host nicotinamide utilization adaptations that correspond with growth recovery increase. EAEC promotes intestinal inflammation and markers of myeloid cell activation. During co-infection, intestinal inflammatory signaling and cellular recruitment responses to EAEC are preserved together with a Giardia-mediated diminishment in myeloid cell activation. Conversely, EAEC extinguishes markers of host energy expenditure regulatory responses to Giardia, as host metabolic adaptations appear exhausted. Integrating immunologic and metabolic profiles during co-pathogen infection and malnutrition, we develop a working mechanistic model of how cumulative diet-induced and pathogen-triggered microbial perturbations result in an increasingly wasted host. PMID:28750066

Cross-modulation of pathogen-specific pathways enhances malnutrition during enteric co-infection with Giardia lamblia and enteroaggregative Escherichia coli.

PubMed

Bartelt, Luther A; Bolick, David T; Mayneris-Perxachs, Jordi; Kolling, Glynis L; Medlock, Gregory L; Zaenker, Edna I; Donowitz, Jeffery; Thomas-Beckett, Rose Viguna; Rogala, Allison; Carroll, Ian M; Singer, Steven M; Papin, Jason; Swann, Jonathan R; Guerrant, Richard L

2017-07-01

Diverse enteropathogen exposures associate with childhood malnutrition. To elucidate mechanistic pathways whereby enteric microbes interact during malnutrition, we used protein deficiency in mice to develop a new model of co-enteropathogen enteropathy. Focusing on common enteropathogens in malnourished children, Giardia lamblia and enteroaggregative Escherichia coli (EAEC), we provide new insights into intersecting pathogen-specific mechanisms that enhance malnutrition. We show for the first time that during protein malnutrition, the intestinal microbiota permits persistent Giardia colonization and simultaneously contributes to growth impairment. Despite signals of intestinal injury, such as IL1α, Giardia-infected mice lack pro-inflammatory intestinal responses, similar to endemic pediatric Giardia infections. Rather, Giardia perturbs microbial host co-metabolites of proteolysis during growth impairment, whereas host nicotinamide utilization adaptations that correspond with growth recovery increase. EAEC promotes intestinal inflammation and markers of myeloid cell activation. During co-infection, intestinal inflammatory signaling and cellular recruitment responses to EAEC are preserved together with a Giardia-mediated diminishment in myeloid cell activation. Conversely, EAEC extinguishes markers of host energy expenditure regulatory responses to Giardia, as host metabolic adaptations appear exhausted. Integrating immunologic and metabolic profiles during co-pathogen infection and malnutrition, we develop a working mechanistic model of how cumulative diet-induced and pathogen-triggered microbial perturbations result in an increasingly wasted host.

Chitin synthetase in encysting Giardia lamblia and Entamoeba invadens

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

Das, S.; Gillin, F.D.

1987-05-01

Giardia lamblia (Gl) and Entamoeba invadens (Ei) are protozoan parasites with two morphologic stages in their life cycles. Motile trophozoites colonize the intestine of humans and reptiles respectively. Water resistant cysts, which can survive outside the host, transmit infection. In vitro cyst formation of Ei from trophozoites has been reported, and the authors have recently induced in vitro encystation of Gl. Although the cyst walls of both parasites contain chitin, it synthesis by encysting trophozoites has not been reported. The authors now show that encystation conditions greatly increase chitin synthetase (CS) specific activity (incorporation of /sup 3/H GlcNAc from UDP-GlcNAcmore » into TCA-or alcohol-precipitable material). Extracts of encysting Gl incorporated 3.6 nmol/mg protein in 5 hr compared to < 0.005 in controls. Extracts of encysting Fi incorporated 4.8 n mol/mg protein, compared to 1.7 in the control. CS activity of both parasites requires preformed chitin. The Gl enzyme requires a reducing agent, is inhibited by digitonin and the CS inhibitors, polyoxin D and Nikkomycin, but not by tunicamycin. The product is digested by chitinase. Ei enzyme does not require a reducing agent and is stimulated by 1 mg/ml digitonin, but inhibited by higher concentrations. These studies demonstrate CS enzymes which may play important roles in encystation of Gl and Ei.« less

Mucosal delivery of a transmission-blocking DNA vaccine encoding Giardia lamblia CWP2 by Salmonella typhimurium bactofection vehicle.

PubMed

Abdul-Wahid, Aws; Faubert, Gaétan

2007-12-05

In this study, we investigated the use of Salmonella typhimurium (STM1 strain) as a bactofection vehicle to deliver a transmission-blocking DNA vaccine (TBDV) plasmid to the intestinal immune system. The gene encoding the full length cyst wall protein-2 (CWP2) from Giardia lamblia was subcloned into the pCDNA3 mammalian expression vector and stably introduced into S. typhimurium STM1. Eight-week-old female BALB/c mice were orally immunized every 2 weeks, for a total of three immunizations. Vaccinated and control mice were sacrificed 1 week following the last injection. Administration of the DNA vaccine led to the production of CWP2-specific cellular immune responses characterized by a mixed Th1/Th2 response. Using ELISA, antigen-specific IgA and IgG antibodies were detected in intestinal secretions. Moreover, analysis of sera demonstrated that the DNA immunization also stimulated the production of CWP2-specific IgG antibodies that were mainly of the IgG2a isotype. Finally, challenge infection with live Giardia muris cysts revealed that mice receiving the CWP2-encoding DNA vaccine were able to reduce cyst shedding by approximately 60% compared to control mice. These results demonstrate, for the first time, the development of parasite transmission-blocking immunity at the intestinal level following the administration of a mucosal DNA vaccine delivered by S. typhimurium STM1.

The detection of Giardia muris and Giardia lamblia cysts by immunofluorescence in animal tissues and fecal samples subjected to cycles of freezing and thawing.

PubMed

Erlandsen, S L; Sherlock, L A; Bemrick, W J

1990-04-01

The effects of freezing and thawing on the detection of selected Giardia spp. cysts were investigated using immunofluorescence, bright field microscopy, and low voltage scanning electron microscopy (SEM). Giardia muris cysts were obtained from either animal carcasses, fecal pellets, or isolated cyst preparations, whereas Giardia lamblia cysts were isolated from fecal samples. These samples were stained using an immunofluorescence technique after 1-3 freezing (-16 C) and thawing (20 C) cycles. Cysts were detected successfully by immunofluorescence in all samples. However, in those samples subjected to freeze-thawing, the cyst walls often became distorted and then were not detectable by bright field microscopy. Low voltage SEM demonstrated that the filaments in the distorted cyst wall underwent rearrangements of interfilament spacing. Quantitation of cyst recovery after freezing and thawing demonstrated that a substantial loss occurred after 1 cycle of alternating temperature when low concentrations of cysts were used, but not with high concentrations of cysts. Cyst recovery, after 3 freezing and thawing cycles, was dramatically lowered irrespective of the initial cyst concentration. These results demonstrated that immunofluorescence was an effective technique for the detection of Giardia spp. cysts in frozen samples and would suggest that freezing and thawing of fecal samples could prevent the detection of cysts when only bright field microscopy was employed.

Prevalence of Soil-Transmitted Helminthiases and Schistosomiasis in Preschool Age Children in Mwea Division, Kirinyaga South District, Kirinyaga County, and Their Potential Effect on Physical Growth

PubMed Central

Mkoji, Gerald M.

2017-01-01

Intestinal parasitic infections can significantly contribute to the burden of disease, may cause nutritional and energetic stress, and negatively impact the quality of life in low income countries of the world. This cross-sectional study done in Mwea irrigation scheme, in Kirinyaga, central Kenya, assessed the public health significance of soil-transmitted helminthiases (STH), schistosomiasis, and other intestinal parasitic infections, among 361 preschool age children (PSAC) through fecal examination, by measuring anthropometric indices, and through their parents/guardians, by obtaining sociodemographic information. Both intestinal helminth and protozoan infections were detected, and, among the soil-transmitted helminth parasites, there were Ascaris lumbricoides (prevalence, 3%), Ancylostoma duodenale (<1%), and Trichuris trichiura (<1%). Other intestinal helminths were Hymenolepis nana (prevalence, 3.6%) and Enterobius vermicularis (<1%). Schistosoma mansoni occurred at a prevalence of 5.5%. Interestingly, the protozoan, Giardia lamblia (prevalence, 14.7%), was the most common among the PSAC. Other protozoans were Entamoeba coli (3.9%) and Entamoeba histolytica (<1). Anthropometric indices showed evidence of malnutrition. Intestinal parasites were associated with hand washing behavior, family size, water purification, and home location. These findings suggest that G. lamblia infection and malnutrition may be significant causes of ill health among the PSAC in Mwea, and, therefore, an intervention plan is needed. PMID:29138640

Subclinical Enteric Parasitic Infections and Growth Faltering in Infants in São Tomé, Africa: A Birth Cohort Study

PubMed Central

Garzón, Marisol; Seixas, Jorge; Papoila, Ana Luísa; Alves, Marta

2018-01-01

The associations between enteric pathogenic parasites and growth in infants in São Tomé were explored using a refined anthropometric approach to recognize early growth faltering. A birth cohort study was conducted with follow-up to 24 months of age. Microscopic examination for protozoa and soil-transmitted helminths was performed. Anthropometric assessments included: z-scores for weight-for-length (WLZ), length-for-age (LAZ), weight (WAVZ) and length velocities (LAVZ), length-for-age difference (LAD), and wasting and stunting risk (≤−1 SD). Generalized additive mixed effects regression models were used to explore the associations between anthropometric parameters and enteric parasitic infections and cofactors. A total of 475 infants were enrolled, and 282 completed the study. The great majority of infants were asymptomatic. Giardia lamblia was detected in 35.1% of infants in at least one stool sample, helminths in 30.4%, and Cryptosporidium spp. in 14.7%. Giardia lamblia and helminth infections were significantly associated with mean decreases of 0.10 in LAZ and 0.32 in LAD, and of 0.16 in LAZ and 0.48 in LAD, respectively. Cryptosporidium spp. infection was significantly associated with a mean decrease of 0.43 in WAVZ and 0.55 in LAVZ. The underestimated association between subclinical parasitic enteric infections and mild growth faltering in infants should be addressed in public health policies. PMID:29621166

Webuye Health and Demographic Surveillance Systems Baseline Survey of Soil-Transmitted Helminths and Intestinal Protozoa among Children up to Five Years

PubMed Central

Obala, A. A.; Simiyu, C. J.; Odhiambo, D. O.; Nanyu, V.; Chege, P.; Downing, R.; Mwaliko, E.; Mwangi, A. W.; Menya, D.; Chelagat, D.; Nyamogoba, H. D. N.; Ayuo, P. O.; O'Meara, W. P.; Twagirumukiza, M.; Vandenbroek, D.; Otsyula, B. B. O.; de Maeseneer, J.

2013-01-01

Background. The intestinal parasitic infections (IPIs) are globally endemic, and they constitute the greatest cause of illness and disease worldwide. Transmission of IPIs occurs as a result of inadequate sanitation, inaccessibility to potable water, and poor living conditions. Objectives. To determine a baseline prevalence of IPIs among children of five years and below at Webuye Health and Demographic Surveillance (HDSS) area in western Kenya. Methods. Cross-sectional survey was used to collect data. Direct saline and formal-ether-sedimentation techniques were used to process the specimens. Descriptive and inferential statistics such as Chi-square statistics were used to analyze the data. Results. A prevalence of 52.3% (417/797) was obtained with the male child slightly more infected than the female (53.5% versus 51%), but this was not significant (χ 2 = 0.482, P > 0.05). Giardia lamblia and Entamoeba histolytica were the most common pathogenic IPIs with a prevalence of 26.1% (208/797) and 11.2% (89/797), respectively. Soil-transmitted helminths (STHs) were less common with a prevalence of 4.8% (38/797), 3.8% (30/797), and 0.13% (1/797) for Ascaris lumbricoides, hookworms, and Trichuris trichiura, respectively. Conclusions. Giardia lamblia and E. histolytica were the most prevalent pathogenic intestinal protozoa, while STHs were less common. Community-based health promotion techniques are recommended for controlling these parasites. PMID:23533444

Genetic Analysis of a Novel Human Adenovirus With a Serologically Unique Hexon and a Recombinant Fiber Gene

DTIC Science & Technology

2011-09-07

diarrhea and was subsequently hospitalized. Cryptosporidium parvum and Giardia lamblia were also found in the fecal matter of the patient; therefore, the... bovine serum (FBS), penicillin (200 U/ml), L-glutamine (2 mM), Fungizone (1 mg/ml), and streptomycin (200 mg/ml). HAdV-D58 was investigated serologi... particles were separated from Hep-2 cells by ultracentrifugation. Genomic DNA was acquired from viral particles using AccuPrep Genomic DNA Extraction Kit

Observations on the intestinal protozoa infecting man in Rhodesia.

PubMed

Goldsmid, J M; Rogers, S; Mahomed, K

1976-09-18

Humans in Rhodesia harbour a wide range of intestinal protozoa. Of the species included, Entamoeba histolytica, Entamoeba coli and Giardia lamblia have previously been recorded. Other species which are either rarely reported or which have previously never been reported from this country, include Trichomonas hominis, Chilomastix mesnili, Enteromonas hominis, Retortamonas intestinalis, Balantidum coli,Entamoeba hartmanni,Entamoeba histolytica Laredo. Endolimax nana, Dientamoeba fragilis and Isospora belli. The importance in Rhodesia of these species, and especially of E. histolytica, is discussed.

Antigiardial activity of glycoproteins and glycopeptides from Ziziphus honey.

PubMed

Mohammed, Seif Eldin A; Kabashi, Ahmed S; Koko, Waleed S; Azim, M Kamran

2015-01-01

Natural honey contains an array of glycoproteins, proteoglycans and glycopeptides. Size-exclusion chromatography fractionated Ziziphus honey proteins into five peaks with molecular masses in the range from 10 to >200 kDa. The fractionated proteins exhibited in vitro activities against Giardia lamblia with IC50 values ≤ 25 μg/mL. Results indicated that honey proteins were more active as antiprotozoal agents than metronidazole. This study indicated the potential of honey proteins and peptides as novel antigiardial agents.

Parasitological Evaluation of a Foodhandler Population Cohort in Panama: Risk Factors for Intestinal Parasitism.

DTIC Science & Technology

1990-06-01

Infections " Infections Infected ’ Infected Sex Giardia lamblia 63 46ri 49 25% Male 135 69% Entamoeba coli 21 15%; 19 l0%Ascaris... Infections in Panama 251 TABLE I TABLE U1 BREAKDOWN OF STUDY POPULATION BY SEX . ETHNIC GROUP. OVA/PARASITE EXAM AND CULTURE RESULTS IN STUDY AGE...CARRIAGE BY SEX , ETHNIC GROUP AND TRANSMISSION RISK GROUP Number of Number Variable Individuals Infected AR RR (95% CI) Intestinal parasitism Sex Male 135

Class B Alkaline Stabilization to Achieve Pathogen Inactivation

PubMed Central

Bean, Christine L.; Hansen, Jacqueline J.; Margolin, Aaron B.; Balkin, Helene; Batzer, Glenda; Widmer, Giovanni

2007-01-01

Liming is a cost-effective treatment currently employed in many Class B biosolids production plants in the United States. A bench scale model of lime stabilization was designed to evaluate the persistence of viral, bacterial and parasitic pathogens. The survival of fecal coliforms, Salmonella, adenovirus type 5, rotavirus Wa, bacteriophage MS-2, Cryptosporidium parvum oocysts, Giardia lamblia cysts, and Ascaris lumbricoides ova was evaluated under lime stabilization conditions in a water matrix. Fecal coliforms and Salmonella were undetectable following 2 hours of lime stabilization, demonstrating a 7-log reduction. Adenovirus, MS-2 and rotavirus were below detectable levels following 2 h of liming, demonstrating a 4-log reduction. G. lamblia cysts were also inactivated. A. lumbricoides ova remained viable following 72 hours of liming as did C. parvum oocysts. While this study confirmed that Ascaris ova are resistant to liming, their scarcity in sludge and low recovery efficiencies limit their use as indicator. The persistence of C. parvum oocysts after exposure to lime, suggests that this parasite would be a better choice as indicator for evaluating biosolids intended for land application. The studies done with adenovirus Type 5, rotavirus Wa and male specific bacteriophage provided preliminary data demonstrating similar inactivation rates. Monitoring anthropogenic viruses is a time consuming, labor intensive and expensive process. If further studies could demonstrate that phage could be used as an indicator of other enteric viruses, enhanced monitoring could result in greater acceptance of land application of biosolids while demonstrating no increased public health threat. PMID:17431316

Intestinal parasitism in the United States: update on a continuing problem.

PubMed

Kappus, K D; Lundgren, R G; Juranek, D D; Roberts, J M; Spencer, H C

1994-06-01

To document patterns of intestinal parasitism in the United States, we analyzed results of 216,275 stool specimens examined by the state diagnostic laboratories in 1987; parasites were found in 20.0%. Percentages were highest for protozoans: Giardia lamblia (7.2%), Entamoeba coli and Endolimax nana (4.2% each), Blastocystis hominis (2.6%), and Entamoeba histolytica (0.9%). The most commonly identified helminths were nematodes: hookworm (1.5%), Trichuris trichiura (1.2%), and Ascaris lumbricoides (0.8%). Identifications of G. lamblia increased broadly from the 4.0% average found in 1979, with 40 states reporting increases and seven reporting decreases. Seasonally, Giardia identifications increased in the summer and fall, especially in the Midwest. Nine states reported hookworms in more than 2% of specimens; none were states with indigenous transmission. We analyzed similar, but abbreviated, data for 1991; parasites were found in 19.7% of the 178,786 specimens and Giardia was found in 5.6%. States reporting percentages of Giardia identification in the highest quartile for both 1987 and 1991 were located in the Midwest or in the Northwest. Cryptosporidium was identified in both the 1987 and 1991 surveys; it had not been identified in a previous survey. For each year, Cryptosporidium was reported from 25 states across the country (for both years in 17 states). We conclude that intestinal parasitism should not be overlooked as a cause of gastrointestinal illness in the United States and that the prevalence of Giardia may be increasing.

Intestinal protozoa in HIV-infected patients in Apulia, South Italy.

PubMed Central

Brandonisio, O.; Maggi, P.; Panaro, M. A.; Lisi, S.; Andriola, A.; Acquafredda, A.; Angarano, G.

1999-01-01

Protozoa are important enteric pathogens in patients with human immunodeficiency virus (HIV) infection. In this study the prevalence of intestinal protozoa in 154 HIV-infected patients, with or without diarrhoea, in our region (Apulia, South Italy) was evaluated between December 1993 and February 1998. In the majority of patients CD4+ T cell count was below 200/microl. The overall prevalence of intestinal protozoa was 43/154 (27.92%). Twenty-eight (43.08%) out of 65 patients with diarrhoea and 15 (16-85%) out of 89 non-diarrhoeic patients were parasitized. In particular, in the group of 65 patients with diarrhoea the following protozoa were identified: Cryptosporidium parvum in 14 (21.54%), Blastocystis hominis in 7 (10.77%), microsporidia in 6 (9.23%), Giardia lamblia in 4 (6.15%) and Isospora belli in 1 (1.54%). Three patients were Cryptosporidium parvum-microsporidia co-infected. In patients without intestinal symptoms, prevalence was 3/89 (3.37%) for Cryptosporidium parvum, 9/89 (10.11%) for Blastocystis hominis, 1/89 (1.12%) for microsporidia and 2/89 (2.25%) for Giardia lamblia. A significant (P<0.001) correlation was observed between protozoan infection and the presence of diarrhoea. In particular, Cryptosporidium parvum and microsporidia infections were significantly (P<0.001) and P = 0.046, respectively) associated with diarrhoeal illness. Moreover, the majority of cases of cryptosporidiosis were first diagnosed in the periods of heaviest rainfall. Therefore, drinking water contamination may be a possible source of human infection in our area. PMID:10694157

Prevalence of bacteria and intestinal parasites among food-handlers in Gondar town, northwest Ethiopia.

PubMed

Andargie, Gashaw; Kassu, Afework; Moges, Feleke; Tiruneh, Moges; Huruy, Kahsay

2008-12-01

Food-handlers with poor personal hygiene working in food-service establishments could be potential sources of infection due to pathogenic organisms. The study was undertaken to determine the prevalence of bacteria and intestinal parasites among 127 food-handlers working in the cafeterias of the University of Gondar and the Gondar Teachers Training College, Gondar, Ethiopia. Fingernail contents of both the hands and stool specimens were collected from all the 127 food-handlers. The samples were examined for bacteria and intestinal parasites following standard procedures. Coagulase-negative staphylococci were the predominant bacteria species (41.7%) isolated from fingernail contents, followed by Staphylococcus aureus (16.5%), Klebsiella species (5.5%), Escherichia coli (3.1%), Serratia species (1.58%), Citrobacter species (0.8%), and Enterobacter species (0.8%). Shigella species were isolated from stool samples of four food-handlers (3.1%). None of the food-handlers was positive for Salmonella species and Shigella species in respect of their fingernail contents. No intestinal parasites were detected from fingernail contents. Intestinal parasites detected in the stools of the food-handlers included Ascaris lumbricoides (18.11%), Strongyloides stercoralis (5.5%), Entamoeba histolytica/dispar (1.6%), Trichuris trichiura (1.6%), hookworm species (0.8%), Gardia lamblia (0.8%), and Schistosoma mansoni (0.8%); 1.6% of the study subjects were positive for each of A. lumbricoides, T. trichiura, hookworm, and G. lamblia. The findings emphasize the importance of food-handlers as potential sources of infections and suggest health institutions for appropriate hygienic and sanitary control measures.

Rapid Detection and Enumeration of Giardia lamblia Cysts in Water Samples by Immunomagnetic Separation and Flow Cytometric Analysis ▿ †

PubMed Central

Keserue, Hans-Anton; Füchslin, Hans Peter; Egli, Thomas

2011-01-01

Giardia lamblia is an important waterborne pathogen and is among the most common intestinal parasites of humans worldwide. Its fecal-oral transmission leads to the presence of cysts of this pathogen in the environment, and so far, quantitative rapid screening methods are not available for various matrices, such as surface waters, wastewater, or food. Thus, it is necessary to establish methods that enable reliable rapid detection of a single cyst in 10 to 100 liters of drinking water. Conventional detection relies on cyst concentration, isolation, and confirmation by immunofluorescence microscopy (IFM), resulting in low recoveries and high detection limits. Many different immunomagnetic separation (IMS) procedures have been developed for separation and cyst purification, so far with variable but high losses of cysts. A method was developed that requires less than 100 min and consists of filtration, resuspension, IMS, and flow cytometric (FCM) detection. MACS MicroBeads were used for IMS, and a reliable flow cytometric detection approach was established employing 3 different parameters for discrimination from background signals, i.e., green and red fluorescence (resulting from the distinct pattern emitted by the fluorescein dye) and sideward scatter for size discrimination. With spiked samples, recoveries exceeding 90% were obtained, and false-positive results were never encountered for negative samples. Additionally, the method was applicable to naturally occurring cysts in wastewater and has the potential to be automated. PMID:21685159

14-3-3 Regulates Actin Filament Formation in the Deep-Branching Eukaryote Giardia lamblia

PubMed Central

Xu, Jennifer; Steele-Ogus, Melissa; Alas, Germain C. M.

2017-01-01

ABSTRACT The phosphoserine/phosphothreonine-binding protein 14-3-3 is known to regulate actin; this function has been previously attributed to sequestration of phosphorylated cofilin. 14-3-3 was identified as an actin-associated protein in the deep-branching eukaryote Giardia lamblia; however, Giardia lacks cofilin and all other canonical actin-binding proteins (ABPs). Thus, the role of G. lamblia 14-3-3 (Gl-14-3-3) in actin regulation was unknown. Gl-14-3-3 depletion resulted in an overall disruption of actin organization characterized by ectopically distributed short actin filaments. Using phosphatase and kinase inhibitors, we demonstrated that actin phosphorylation correlated with destabilization of the actin network and increased complex formation with 14-3-3, while blocking actin phosphorylation stabilized actin filaments and attenuated complex formation. Giardia’s sole Rho family GTPase, Gl-Rac, modulates Gl-14-3-3’s association with actin, providing the first connection between Gl-Rac and the actin cytoskeleton in Giardia. Giardia actin (Gl-actin) contains two putative 14-3-3 binding motifs, one of which (S330) is conserved in mammalian actin. Mutation of these sites reduced, but did not completely disrupt, the association with 14-3-3. Native gels and overlay assays indicate that intermediate proteins are required to support complex formation between 14-3-3 and actin. Overall, our results support a role for 14-3-3 as a regulator of actin; however, the presence of multiple 14-3-3–actin complexes suggests a more complex regulatory relationship than might be expected for a minimalistic parasite. IMPORTANCE Giardia lacks canonical actin-binding proteins. Gl-14-3-3 was identified as an actin interactor, but the significance of this interaction was unknown. Loss of Gl-14-3-3 results in ectopic short actin filaments, indicating that Gl-14-3-3 is an important regulator of the actin cytoskeleton in Giardia. Drug studies indicate that Gl-14-3-3 complex formation is in part phospho-regulated. We demonstrate that complex formation is downstream of Giardia’s sole Rho family GTPase, Gl-Rac. This result provides the first mechanistic connection between Gl-Rac and Gl-actin in Giardia. Native gels and overlay assays indicate intermediate proteins are required to support the interaction between Gl-14-3-3 and Gl-actin, suggesting that Gl-14-3-3 is regulating multiple Gl-actin complexes. PMID:28932813

Wide-field fluorescent microscopy on a cell-phone.

PubMed

Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

2011-01-01

We demonstrate wide-field fluorescent imaging on a cell-phone, using compact and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. Battery powered light-emitting diodes (LEDs) are used to side-pump the sample of interest using butt-coupling. The pump light is guided within the sample cuvette to excite the specimen uniformly. The fluorescent emission from the sample is then imaged with an additional lens that is put in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to the detection path, an inexpensive plastic color filter is sufficient to create the dark-field background needed for fluorescent imaging. The imaging performance of this light-weight platform (~28 grams) is characterized with red and green fluorescent microbeads, achieving an imaging field-of-view of ~81 mm(2) and a spatial resolution of ~10 μm, which is enhanced through digital processing of the captured cell-phone images using compressive sampling based sparse signal recovery. We demonstrate the performance of this cell-phone fluorescent microscope by imaging labeled white-blood cells separated from whole blood samples as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts.

Parasitic disease control in a residential facility for the mentally retarded.

PubMed Central

Thacker, S B; Simpson, S; Gordon, T J; Wolfe, M; Kimball, A M

1979-01-01

Asymptomatic infection with either Entameba histolytica or Giardia lamblia was found in 61 per cent of the residents of a dormitory in an institution for the mentally retarded; two other dormitories had rates of 20 per cent and 22 per cent. Drug therapy was successfully undertaken in all three dormitories, and environmental improvements were introduced in the heavily infected dormitory. A one-year follow-up showed a reduction in parasitic disease in two dormitories but, in the most heavily infected dormitory, infection had returned to pretreatment levels. PMID:389070

Sexually transmitted infections manifesting as proctitis

PubMed Central

Lamb, Chris A; Lamb, Elizabeth Iris Mary; Mansfield, John C; Sankar, K Nathan

2013-01-01

There is a rising incidence of several sexually transmitted infections (STIs), many of which can present with proctitis. Causative organisms include Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus, Treponema pallidum (syphilis), Giardia lamblia (giardiasis) and Entamoeba histolytica (amoebiasis). This paper outlines important clinical discriminators and key investigations to distinguish these organisms from non-infective pathology that include inflammatory bowel disease, solitary rectal ulcer syndrome and Behçet's syndrome. Management of these infections is described and suggestions are made for successful gastroenterology clinical consultation when an STI is suspected. PMID:23914292

Prevalence of Strongyloides stercoralis and Other Intestinal Parasites among Institutionalized Mentally Disabled Individuals in Rasht, Northern Iran

PubMed Central

SAEIDINIA, Amin; TAVAKOLI, Ilnaz; NAGHIPOUR, Mohammad Reza; RAHMATI, Behnaz; GHAVAMI LAHIJI, Hossein; SALKHORI, Omid; ASHRAFI, Keyhan

2016-01-01

Background: We aimed to determine the status of strongyloidiasis in mentally disabled population in the institutional places in Rasht City, the capital of Guilan Province, northern Iran. Methods: This cross-sectional study was conducted in 8 institutions for mentally retarded population in Rasht in 2013. Before collecting the samples, a questionnaire was filled out for each participant by an expert person. A single stool sample was obtained from each of the 173 subjects and examined using direct wet mount, formalin-ether concentration technique and agar plate culture method. Results: A total of 173 mentally disabled individuals aged 2–57 (25.69±11.56) yr old were studied. Stool examination showed that 51 (29.5%) cases were infected with at least one parasite. Of 173 studied cases only 10 (5.8%) individuals were infected with pathogenic parasites, of which 2 (1.2%) cases were infected with Strongyloides stercoralis and 8 (4.6%) with Giardia lamblia. On the other hand, 42 (24.3%) of the studied population were infected with non-pathogenic intestinal protozoa such as Blastocystis hominis (n=29, 16.8%), Entamoeba coli (n=16, 9.2%) and Endolimax nana (n=4, 2.3%). Mixed protozoal infections were observed in 8 (4.6%) individuals. Conclusion: The prevalence rate of S. stercoralis in mentally disabled individuals in Rasht was somewhat higher than those of normal population of the province. The same picture was seen when the prevalence of G. lamblia and non-pathogenic protozoa in normal and mentally disabled populations were compared. PMID:28127364

Microbiological risk infection assessment using QMRA in agriculture systems in Côte d'Ivoire, West Africa.

PubMed

Kouamé, Parfait K; Nguyen-Viet, Hung; Dongo, Kouassi; Zurbrügg, Christian; Biémi, Jean; Bonfoh, Bassirou

2017-10-28

Poor wastewater management that results from a lack of appropriate sanitation infrastructure contributes to increasing health risks in urban areas in Côte d'Ivoire. We assessed the health risks associated with the use of wastewater for watering salad destined for human consumption, to help local authorities in developing appropriate risk mitigation measures for Yamoussoukro, the political capital of Côte d'Ivoire. We applied a stochastic approach based on quantitative microbiological risk assessment (QMRA), focusing on wastewater for farming activities and salad consumption at the household level. Farming activities rely on a large degree on contaminated water and are conducted without any protection. The QMRA highlights that the poor quality of watering water increased the microbiological risk of the two assessed groups of urban farmers and individual households. The annual risk of infection due to watering wastewater in the city is estimated at 0.01 per person per year (pppy) for Giardia lamblia and 0.2 pppy for Escherichia coli O157:H7. The annual risk from salad consumption is 0.01 pppy for G. lamblia and 0.9 pppy for E. coli O157:H7. Both the annual risks from farming activities and salad consumption were higher than the tolerable standard of risk of 10 -4 pppy as defined by the World Health Organization. There is a need to conduct a risk analysis and a cost-effectiveness study on intervention to improve public health and the livelihoods of the producers which are women in majority in Yamoussoukro.

Prevalence of Bacteria and Intestinal Parasites among Food-handlers in Gondar Town, Northwest Ethiopia

PubMed Central

Andargie, Gashaw; Kassu, Afework; Moges, Feleke; Tiruneh, Moges; Huruy, Kahsay

2008-01-01

Food-handlers with poor personal hygiene working in food-service establishments could be potential sources of infection due to pathogenic organisms. The study was undertaken to determine the prevalence of bacteria and intestinal parasites among 127 food-handlers working in the cafeterias of the University of Gondar and the Gondar Teachers Training College, Gondar, Ethiopia. Fingernail contents of both the hands and stool specimens were collected from all the 127 food-handlers. The samples were examined for bacteria and intestinal parasites following standard procedures. Coagulase-negative staphylococci were the predominant bacteria species (41.7%) isolated from fingernail contents, followed by Staphylococcus aureus (16.5%), Klebsiella species (5.5%), Escherichia coli (3.1%), Serratia species (1.58%), Citrobacter species (0.8%), and Enterobacter species (0.8%). Shigella species were isolated from stool samples of four food-handlers (3.1%). None of the food-handlers was positive for Salmonella species and Shigella species in res-pect of their fingernail contents. No intestinal parasites were detected from fingernail contents. Intestinal parasites detected in the stools of the food-handlers included Ascaris lumbricoides (18.11%), Strongyloides stercoralis (5.5%), Entamoeba histolytica/dispar (1.6%), Trichuris trichiura (1.6%), hookworm species (0.8%), Gardia lamblia (0.8%), and Schistosoma mansoni (0.8%); 1.6% of the study subjects were positive for each of A. lumbricoides, T. trichiura, hookworm, and G. lamblia. The findings emphasize the importance of food-handlers as potential sources of infections and suggest health institutions for appropriate hygienic and sanitary control measures. PMID:19069624

A detailed look at the cytoskeletal architecture of the Giardia lamblia ventral disc.

PubMed

Brown, Joanna R; Schwartz, Cindi L; Heumann, John M; Dawson, Scott C; Hoenger, Andreas

2016-04-01

Giardia lamblia is a protistan parasite that infects and colonizes the small intestine of mammals. It is widespread and particularly endemic in the developing world. Here we present a detailed structural study by 3-D negative staining and cryo-electron tomography of a unique Giardia organelle, the ventral disc. The disc is composed of a regular array of microtubules and associated sheets, called microribbons that form a large spiral, held together by a myriad of mostly unknown associated proteins. In a previous study we analyzed by cryo-electron tomography the central microtubule portion (here called disc body) of the ventral disc and found a large portion of microtubule associated inner (MIPs) and outer proteins (MAPs) that render these microtubules hyper-stable. With this follow-up study we expanded our 3-D analysis to different parts of the disc such as the ventral and dorsal areas of the overlap zone, as well as the outer disc margin. There are intrinsic location-specific characteristics in the composition of microtubule-associated proteins between these regions, as well as large differences between the overall architecture of microtubules and microribbons. The lateral packing of microtubule-microribbon complexes varies substantially, and closer packing often comes with contracted lateral tethers that seem to hold the disc together. It appears that the marginal microtubule-microribbon complexes function as outer, laterally contractible lids that may help the cell to clamp onto the intestinal microvilli. Furthermore, we analyzed length, quantity, curvature and distribution between different zones of the disc, which we found to differ from previous publications. Copyright © 2016 Elsevier Inc. All rights reserved.

The minimal kinome of Giardia lamblia illuminates early kinase evolution and unique parasite biology

PubMed Central

2011-01-01

Background The major human intestinal pathogen Giardia lamblia is a very early branching eukaryote with a minimal genome of broad evolutionary and biological interest. Results To explore early kinase evolution and regulation of Giardia biology, we cataloged the kinomes of three sequenced strains. Comparison with published kinomes and those of the excavates Trichomonas vaginalis and Leishmania major shows that Giardia's 80 core kinases constitute the smallest known core kinome of any eukaryote that can be grown in pure culture, reflecting both its early origin and secondary gene loss. Kinase losses in DNA repair, mitochondrial function, transcription, splicing, and stress response reflect this reduced genome, while the presence of other kinases helps define the kinome of the last common eukaryotic ancestor. Immunofluorescence analysis shows abundant phospho-staining in trophozoites, with phosphotyrosine abundant in the nuclei and phosphothreonine and phosphoserine in distinct cytoskeletal organelles. The Nek kinase family has been massively expanded, accounting for 198 of the 278 protein kinases in Giardia. Most Neks are catalytically inactive, have very divergent sequences and undergo extensive duplication and loss between strains. Many Neks are highly induced during development. We localized four catalytically active Neks to distinct parts of the cytoskeleton and one inactive Nek to the cytoplasm. Conclusions The reduced kinome of Giardia sheds new light on early kinase evolution, and its highly divergent sequences add to the definition of individual kinase families as well as offering specific drug targets. Giardia's massive Nek expansion may reflect its distinctive lifestyle, biphasic life cycle and complex cytoskeleton. PMID:21787419

Triage and protocol recommendations for the parasitology laboratory based on an epidemiological investigation of parasite diagnostics in Ontario laboratories

PubMed Central

Maier, Allison; Krolik, Julia; Majury, Anna

2014-01-01

OBJECTIVES: A study was performed using a subset of Ontario laboratory parasitology data, with three objectives: to describe parasitic infections in Ontario; to identify risk factors for acquiring a parasitic infection using routinely collected information; and to use this information to assess current protocols for parasite testing in laboratories and, in turn, to propose alternatives to optimize the allocation of laboratory resources. METHODS: All parasitology records from January 4, 2010 to September 14, 2010 were reviewed descriptively and risk factor analyses were performed using information collected from requisitions. These results were used to develop preliminary alternative protocols, which considered high-throughput screening tests and inclusion/exclusion criteria for ova and parasite testing; these were then retrospectively analyzed with the dataset to determine appropriateness. RESULTS: Of the 29,260 records analyzed, 10% were multiple samples from single patients submitted on the same day, of which 98% had the same result. Three percent of all parasite tests were positive, with the most prevalent parasites being (in ascending order) Dientamoeba fragilis, Giardia lamblia, Cryptosporidium species and Entamoeba histolytica/dispar. Age and sex were found to be weak risk factors, while rural living was found to be a moderate risk factor for D fragilis, G lamblia and Cryptosporidium infections. The strongest risk factor was travel history, especially for nonendemic parasites. The retrospective analysis of six alternative protocols identified four that may be more efficient than current procedures. CONCLUSIONS: The present study demonstrated that current protocols may be redundant and can be optimized to target prevalent parasites and populations with high risk factors. PMID:25587292

Protozoa as a cause of recurrent abdominal pain in children.

PubMed

Gijsbers, Carolien F M; Schweizer, Joachim J; Büller, Hans A

2013-11-01

The aim of this study was to investigate whether protozoa can be identified as a cause of recurrent abdominal pain (RAP), and whether protozoan infections can be recognized by a specific clinical presentation. For 2 years, all patients (ages 4-16 years) fulfilling the Apley criteria of RAP referred to secondary care were prospectively evaluated for protozoa (Giardia lamblia, Dientamoeba fragilis, Blastocystis hominis) and treated if positive. Re-examination followed at least 10 days after treatment. Disappearance of pain with eradication and a pain-free follow-up of at least 6 months were considered to be indicative of a causal relation with RAP. The predictive value of the characteristics of the pain for protozoan infections was calculated. Of 220 included patients (92 boys, mean age 8.8 years), 215 brought a stool sample; 73 (34%) carried parasites, 10 of whom had 2 parasites, 2 had 3 parasites. Sixty-five patients were treated. Twenty-five (11%) were pain-free after eradication (21 had D fragilis, 8 B hominis, 4 G lamblia), of whom 11 had another infection (2) or constipation (9) as second diagnosis for the pain. Five had recurrence of infection with D fragilis and were again pain-free with eradication. Patients with protozoa as cause of their pain did not show differences with respect to their presentation when compared with patients with an asymptomatic infection and patients without protozoa. Protozoa were found as the cause of pain in 6% to 11% of children with RAP. These patients did not show a characteristic presentation when compared with patients with other causes of abdominal pain.

[Expected epidemic risk from the minimum drinking water content of protozoan agents of enteric parasitic diseases].

PubMed

Novosil'tsev, G I; Chernyshenko, A I; Rusanova, N A; Gracheva, M N; Mel'nikova, L I

2010-01-01

The paper presents information on lambliasis and cryptosporidiosis outbreaks associated with drinking water contamination-associated. It discusses a risk for the emergence of mass outbreaks of lambliasis and cryptosporidiosis among the population of the municipalities of administrative district centers and other human settlements, which are to exercise sanitary and parasitological control over the quality of water of its centralized drinking supply. The significance of this water contamination by lamblia cysts and cryptosporidium oocysts is considered. Calculations are given to predict an epidemic risk and possible ways of its prevention.

The prokaryote-to-eukaryote transition reflected in the evolution of the V/F/A-ATPase catalytic and proteolipid subunits

NASA Technical Reports Server (NTRS)

Hilario, E.; Gogarten, J. P.

1998-01-01

Changes in the primary and quarternary structure of vacuolar and archaeal type ATPases that accompany the prokaryote-to-eukaryote transition are analyzed. The gene encoding the vacuolar-type proteolipid of the V-ATPase from Giardia lamblia is reported. Giardia has a typical vacuolar ATPase as observed from the common motifs shared between its proteolipid subunit and other eukaryotic vacuolar ATPases, suggesting that the former enzyme works as a hydrolase in this primitive eukaryote. The phylogenetic analyses of the V-ATPase catalytic subunit and the front and back halves of the proteolipid subunit placed Giardia as the deepest branch within the eukaryotes. Our phylogenetic analysis indicated that at least two independent duplication and fusion events gave rise to the larger proteolipid type found in eukaryotes and in Methanococcus. The spatial distribution of the conserved residues among the vacuolar-type proteolipids suggest a zipper-type interaction among the transmembrane helices and surrounding subunits of the V-ATPase complex. Important residues involved in the function of the F-ATP synthase proteolipid have been replaced during evolution in the V-proteolipid, but in some cases retained in the archaeal A-ATPase. Their possible implication in the evolution of V/F/A-ATPases is discussed.

Intestinal parasitosis in school children of Lalitpur district of Nepal.

PubMed

Tandukar, Sarmila; Ansari, Shamshul; Adhikari, Nabaraj; Shrestha, Anisha; Gautam, Jyotshana; Sharma, Binita; Rajbhandari, Deepak; Gautam, Shikshya; Nepal, Hari Prasad; Sherchand, Jeevan B

2013-11-09

Enteric parasites are the most common cause of parasitic diseases and cause significant morbidity and mortality, particularly in developing countries like Nepal. The objective of this study was to estimate the prevalence and risk factors of intestinal parasitic infections among school going children of Lalitpur district of Nepal. A total of 1392 stool samples were collected from school children of two government, two private and two community schools of the same district. The stool samples were examined for evidence of parasitic infections by direct microscopy and confirmed by concentration methods (formal ether sedimentation technique or floatation technique by using Sheather's sugar solution). Modified Ziehl-Neelsen (ZN) staining was performed for the detection of coccidian parasites. Prevalence of intestinal parasitosis was found to be 16.7%. The highest prevalence rate was seen with Giardia lamblia (7.4%) followed by Entamoeba histolytica (3.4%) and Cyclospora cayetanensis (1.6%). Children aged 11-15 years and the ones belonging to family of agriculture workers were most commonly affected. Hand washing practice and type of drinking water also showed significant difference. The burden of parasitic infections among the school children, coupled with the poor sanitary conditions in the schools, should be regarded as an issue of public health priority and demands for effective school health programs involving periodic health education and screening.

Rational Design, Synthesis and Evaluation of First Generation Inhibitors of the Giardia lamblia Fructose-1,6-biphosphate Aldolase

PubMed Central

Li, Zhimin; Liu, Zhengang; Cho, Dae Won; Zou, Jiwen; Gong, Maozhen; Breece, Robert M.; Galkin, Andrey; Li, Ling; Zhao, Hong; Maestas, Gabriel D.; Tierney, David L.; Herzberg, Osnat; Dunaway-Mariano, Debra; Mariano, Patrick S.

2011-01-01

Inhibitors of the Giardia lamblia fructose 1,6-bisphosphate aldolase (GlFBPA), which transforms fructose 1,6-bisphosphate (FBP) to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, were designed based on 3-hydroxy-2-pyridone and 1,2-dihydroxypyridine scaffolds that position two negatively charged tetrahedral groups for interaction with substrate phosphate binding residues, a hydrogen bond donor to the catalytic Asp83, and a Zn2+ binding group. The inhibition activities for the GlFBPA catalyzed reaction of FBP of the prepared alkyl phosphonate/phosphate substituted 3-hydroxy-2-pyridinones and a dihydroxypyridine were determined. The 3-hydroxy-2-pyridone inhibitor 8 was found to bind to GlFBPA with an affinity (Ki = 14 μM) that is comparable to that of FBP (Km = 2 μM) or its inert analog TBP (Ki = 1 μM). The X-ray structure of the GlFBPA-inhibitor 8 complex (2.3 Å) shows that 8 binds to the active site in the manner predicted by in silico docking with the exception of coordination with Zn2+. The observed distances and orientation of the pyridone ring O=C-C-OH relative to Zn2+ are not consistent with a strong interaction. To determine if Zn2+coordination occurs in the GlFBPA-inhibitor 8 complex in solution, EXAFS spectra were measured. A four coordinate geometry comprised of the three enzyme histidine ligands and an oxygen atom from the pyridone ring O=C-C-OH was indicated. Analysis of the Zn2+ coordination geometries in recently reported structures of class II FBPAs suggests that strong Zn2+ coordination is reserved for the enediolate-like transition state, accounting for minimal contribution of Zn2+ coordination to binding of 8 to GlFBPA. PMID:21333622

Microbiological and toxicological effects of Perla black bean (Phaseolus vulgaris L.) extracts: in vitro and in vivo studies.

PubMed

Lara-Díaz, Víctor Javier; Gaytán-Ramos, Angel A; Dávalos-Balderas, Alfredo José; Santos-Guzmán, Jesús; Mata-Cárdenas, Benito David; Vargas-Villarreal, Javier; Barbosa-Quintana, Alvaro; Sanson, Misu; López-Reyes, Alberto Gabriel; Moreno-Cuevas, Jorge E

2009-02-01

We investigated the microbiological and toxicological effects of three Perla black bean extracts on the growth and culture of selected pathogenic microorganisms, the toxicity over Vero cell lines and an in vivo rat model. Three different solvents were used to obtain Perla black bean extracts. All three Perla black bean extracts were tested for antibacterial and antiparasitic activity and further analysed for intrinsic cytotoxicity (IC(50)). Methanol Perla black bean extract was used for acute toxicity test in rats, with the up-and-down doping method. All Perla black bean extracts inhibited bacterial growth. Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella oxytoca, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis and Listeria monocytogenes showed inhibition, while Escherichia coli and Enterobacter aerogenes did not. Acidified water and acetic acid Perla black bean extract were tested in parasites. The best IC(50) was observed for Giardia lamblia, while higher concentrations were active against Entamoeba histolytica and Trichomonas vaginalis. The Vero cells toxicity levels (IC(50)) for methanol, acidified water and acetic acid Perla black bean extract were [mean +/- S.D. (95% CI)]: 275 +/- 6.2 (267.9-282.0), 390 +/- 4.6 (384.8-395.2) and 209 +/- 3.39 (205.6-212.4) microg/ml, respectively. In vivo acute toxicity assays did not show changes in absolute organ weights, gross and histological examinations of selected tissues or functional tests. The acetic acid and methanol Perla black bean extract proved to exhibit strong antibacterial activity and the acidified water Perla black bean extract exerted parasiticidal effects against Giardia lamblia, Entamoeba hystolitica and Trichomonas vaginalis. The three Perla black bean extracts assayed over Vero cells showed very low toxicity and the methanol Perla black bean extract in vivo did not cause toxicity.

Intestinal parasitic infections in suburban government schools, Lak Hok subdistrict, Muang Pathum Thani, Thailand.

PubMed

Kitvatanachai, Sirima; Rhongbutsri, Pochong

2013-09-01

To provide baseline information of parasitic infections in 3 suburban government schools, Lakhok subdistrict of Muang Pathum Thani, Thailand. This study was conducted between May-June 2010 using simple direct smear and modified formalin ether and from a population of 1 253 in 3 suburban government schools. Total samples of 202 registered and participated. The average of prevalence of infection from 3 schools was 13.9%, there were 13.7%, 14.3% and 13.9% in N, S and R school, respectively with no significant difference between schools (P>0.05). The infection rates did not show significant difference between genders (P>0.05). The highest rate of infection was 20.4% in Pathom 2 (8 years) students and the lowest was 4% in Pathom 1 (7 years) with statistically difference between age groups (P<0.05). The highest prevalence of pathogenic protozoa was Giardia lamblia (G. lamblia) which was found in 50% of infected cases, followed by 25% of Entamoeba histolytica (E. histolytica) and Blastocystis hominis (B. hominis). The highest prevalence of non-pathogenic protozoa was Endolimax nana (E. nana) which was found in 88.9%, followed by 11.1% of Entamoeba coli (E. coli). Mixed infections between Blastocystis hominis (B. hominis) and Endolimax nana (E. nana) were reported at 7.1%. The only helminthic infection found in this study area was hookworm, found in 1 student (3.8%). The formalin ether concentration technique showed a higher efficacy of detection (78%-100%) than the simple direct smear method (0%-50%). Surveillance of Protozoan infections may need to be focused on suburban areas. Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Frequency, diagnostic performance of coproantigen detection and genotyping of the Giardia among patients referred to a multi-level teaching hospital in northern India.

PubMed

Ghoshal, Ujjala; Shukla, Ratnakar; Pant, Priyannk; Ghoshal, Uday C

Giardiasis, a common gastrointestinal parasitic infection in tropics, is diagnosed on stool microscopy (gold standard); however, its sensitivity is low due to intermittent fecal shedding. Coproantigen detection (ELISA) is useful but requires further evaluation. We aimed to study: (a) detection of Giardia by stool microscopy and/or coproantigen, (b) diagnostic performance of fecal antigen detection and microscopy, and c) genotypic characterization of G. lamblia using PCR specific for triose phosphate isomerase (tpi) gene. Stool samples from 2992 patients were examined by microscopy from March 2013 to March 2015 in a multi level teaching hospital in northern India. Giardia coproantigen detection was performed by ELISA in a subset of patients. Genetic characterization of G. lamblia was performed by PCR targeting tpi gene in a subset of microscopy positive stool samples. Of 2992 patients, 132 (4.4%) had Giardia by microscopy (cyst/trophozoite) and/or ELISA. ELISA was performed in 264 patients; of them, 127 were positive by microscopy. Sensitivity, specificity, positive and negative predictive values of ELISA were 91, 91, 94, and 91%, respectively, using microscopy as a gold standard. PCR was performed in 116 randomly selected samples having Giardia using tpi gene. Assemblages A and B were found among 44 (38%) and 72 (62%) patients, respectively. Assemblage B was more often associated with malnutrition and loss of appetite than A (48/72 [67%] vs. 21/44 [48%], P = 0.044 and 17/72 [24%] vs. 14/44 [32%], P = 0.019). We conclude that 4.4% of studied population had giardiasis. Fecal antigen is a useful method for diagnosis and assemblage B is the most common genotype.

Interactions of Cryptosporidium parvum, Giardia lamblia, Vaccinal Poliovirus Type 1, and Bacteriophages φX174 and MS2 with a Drinking Water Biofilm and a Wastewater Biofilm▿

PubMed Central

Helmi, Karim; Skraber, Sylvain; Gantzer, Christophe; Willame, Raphaël; Hoffmann, Lucien; Cauchie, Henry-Michel

2008-01-01

Biofilms colonizing surfaces inside drinking water distribution networks may provide a habitat and shelter to pathogenic viruses and parasites. If released from biofilms, these pathogens may disseminate in the water distribution system and cause waterborne diseases. Our study aimed to investigate the interactions of protozoan parasites (Cryptosporidium parvum and Giardia lamblia [oo]cysts) and viruses (vaccinal poliovirus type 1, φX174, and MS2) with two contrasting biofilms. First, attachment, persistence, and detachment of the protozoan parasites and the viruses were assessed with a drinking water biofilm. This biofilm was allowed to develop inside a rotating annular reactor fed with tap water for 7 months prior to the inoculation. Our results show that viable parasites and infectious viruses attached to the drinking water biofilm within 1 h and persisted within the biofilm. Indeed, infectious viruses were detected in the drinking water biofilm up to 6 days after the inoculation, while viral genome and viable parasites were still detected at day 34, corresponding to the last day of the monitoring period. Since viral genome was detected much longer than infectious particles, our results raise the question of the significance of detecting viral genomes in biofilms. A transfer of viable parasites and viruses from the biofilm to the water phase was observed after the flow velocity was increased but also with a constant laminar flow rate. Similar results regarding parasite and virus attachment and detachment were obtained using a treated wastewater biofilm, suggesting that our observations might be extrapolated to a wide range of environmental biofilms and confirming that biofilms can be considered a potential secondary source of contamination. PMID:18281435

Interactions of Cryptosporidium parvum, Giardia lamblia, vaccinal poliovirus type 1, and bacteriophages phiX174 and MS2 with a drinking water biofilm and a wastewater biofilm.

PubMed

Helmi, Karim; Skraber, Sylvain; Gantzer, Christophe; Willame, Raphaël; Hoffmann, Lucien; Cauchie, Henry-Michel

2008-04-01

Biofilms colonizing surfaces inside drinking water distribution networks may provide a habitat and shelter to pathogenic viruses and parasites. If released from biofilms, these pathogens may disseminate in the water distribution system and cause waterborne diseases. Our study aimed to investigate the interactions of protozoan parasites (Cryptosporidium parvum and Giardia lamblia [oo]cysts) and viruses (vaccinal poliovirus type 1, phiX174, and MS2) with two contrasting biofilms. First, attachment, persistence, and detachment of the protozoan parasites and the viruses were assessed with a drinking water biofilm. This biofilm was allowed to develop inside a rotating annular reactor fed with tap water for 7 months prior to the inoculation. Our results show that viable parasites and infectious viruses attached to the drinking water biofilm within 1 h and persisted within the biofilm. Indeed, infectious viruses were detected in the drinking water biofilm up to 6 days after the inoculation, while viral genome and viable parasites were still detected at day 34, corresponding to the last day of the monitoring period. Since viral genome was detected much longer than infectious particles, our results raise the question of the significance of detecting viral genomes in biofilms. A transfer of viable parasites and viruses from the biofilm to the water phase was observed after the flow velocity was increased but also with a constant laminar flow rate. Similar results regarding parasite and virus attachment and detachment were obtained using a treated wastewater biofilm, suggesting that our observations might be extrapolated to a wide range of environmental biofilms and confirming that biofilms can be considered a potential secondary source of contamination.

Hsp90 Inhibitors as New Leads To Target Parasitic Diarrheal Diseases

PubMed Central

Shahinas, Dea; Bryant, Clifford; Hirata, Ken; Miyamoto, Yukiko; Hwang, Grace; Gut, Jiri; Renslo, Adam R.; Pillai, Dylan R.; Eckmann, Lars; Reed, Sharon L.; McKerrow, James H.

2014-01-01

Entamoeba histolytica and Giardia lamblia are anaerobic protozoan parasites that cause amebiasis and giardiasis, two of the most common diarrheal diseases worldwide. Current therapy relies on metronidazole, but resistance has been reported and the drug has significant adverse effects. Therefore, it is critical to search for effective, better-tolerated antiamebic and antigiardial drugs. We synthesized several examples of a recently reported class of Hsp90 inhibitors and evaluated these compounds as potential leads for antiparasitic chemotherapy. Several of these inhibitors showed strong in vitro activity against both E. histolytica and G. lamblia trophozoites. The inhibitors were rescreened to discriminate between amebicidal and giardicidal activity and general cytotoxicity toward a mammalian cell line. No mammalian cytotoxicity was found at >100 μM for 48 h for any of the inhibitors. To understand the mechanism of action, a competitive binding assay was performed using the fluorescent ATP analogue bis-ANS (4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid dipotassium salt) and recombinant E. histolytica Hsp90 preincubated in both the presence and absence of Hsp90 inhibitors. There was significant reduction in fluorescence compared to the level in the control, suggesting that E. histolytica Hsp90 is a selective target. The in vivo efficacy and safety of one Hsp90 inhibitor in a mouse model of amebic colitis and giardiasis was demonstrated by significant inhibition of parasite growth at a single oral dose of 5 mg/kg of body weight/day for 7 days and 10 mg/kg/day for 3 days. Considering the results for in vitro activity and in vivo efficacy, Hsp90 inhibitors represent a promising therapeutic option for amebiasis and giardiasis. PMID:24820073

Gastrointestinal infections and diarrheal disease in Ghanaian infants and children: an outpatient case-control study.

PubMed

Krumkamp, Ralf; Sarpong, Nimako; Schwarz, Norbert Georg; Adlkofer, Julia; Adelkofer, Julia; Loag, Wibke; Eibach, Daniel; Hagen, Ralf Matthias; Adu-Sarkodie, Yaw; Tannich, Egbert; May, Jürgen

2015-03-01

Diarrheal diseases are among the most frequent causes of morbidity and mortality in children worldwide, especially in resource-poor areas. This case-control study assessed the associations between gastrointestinal infections and diarrhea in children from rural Ghana. Stool samples were collected from 548 children with diarrhea and from 686 without gastrointestinal symptoms visiting a hospital from 2007-2008. Samples were analyzed by microscopy and molecular methods. The organisms most frequently detected in symptomatic cases were Giardia lamblia, Shigella spp./ enteroinvasive Escherichia coli (EIEC), and Campylobacter jejuni. Infections with rotavirus (adjusted odds ratio [aOR] = 8.4; 95% confidence interval [CI]: 4.3-16.6), C. parvum/hominis (aOR = 2.7; 95% CI: 1.4-5.2) and norovirus (aOR = 2.0; 95%CI: 1.3-3.0) showed the strongest association with diarrhea. The highest attributable fractions (AF) for diarrhea were estimated for rotavirus (AF = 14.3%; 95% CI: 10.9-17.5%), Shigella spp./EIEC (AF = 10.5%; 95% CI: 3.5-17.1%), and norovirus (AF = 8.2%; 95% CI 3.2-12.9%). Co-infections occurred frequently and most infections presented themselves independently of other infections. However, infections with E. dispar, C. jejuni, and norovirus were observed more often in the presence of G. lamblia. Diarrheal diseases in children from a rural area in sub-Saharan Africa are mainly due to infections with rotavirus, Shigella spp./EIEC, and norovirus. These associations are strongly age-dependent, which should be considered when diagnosing causes of diarrhea. The presented results are informative for both clinicians treating gastrointestinal infections as well as public health experts designing control programs against diarrheal diseases.

Central importance of immunoglobulin A in host defense against Giardia spp.

PubMed

Langford, T Dianne; Housley, Michael P; Boes, Marianne; Chen, Jianzhu; Kagnoff, Martin F; Gillin, Frances D; Eckmann, Lars

2002-01-01

The protozoan pathogen Giardia is an important cause of parasitic diarrheal disease worldwide. It colonizes the lumen of the small intestine, suggesting that effective host defenses must act luminally. Immunoglobulin A (IgA) antibodies are presumed to be important for controlling Giardia infection, but direct evidence for this function is lacking. B-cell-independent effector mechanisms also exist and may be equally important for antigiardial host defense. To determine the importance of the immunoglobulin isotypes that are transported into the intestinal lumen, IgA and IgM, for antigiardial host defense, we infected gene-targeted mice lacking IgA-expressing B-cells, IgM-secreting B-cells, or all B-cells as controls with Giardia muris or Giardia lamblia GS/M-83-H7. We found that IgA-deficient mice could not eradicate either G. muris or G. lamblia infection, demonstrating that IgA is required for their clearance. Furthermore, although neither B-cell-deficient nor IgA-deficient mice could clear G. muris infections, IgA-deficient mice controlled infection significantly better than B-cell-deficient mice, suggesting the existence of B-cell-dependent but IgA-independent antigiardial defenses. In contrast, mice deficient for secreted IgM antibodies cleared G. muris infection normally, indicating that they have no unique functions in antigiardial host defense. These data, together with the finding that B-cell-deficient mice have some, albeit limited, residual capacity to control G. muris infection, show that IgA-dependent host defenses are central for eradicating Giardia spp. Moreover, B-cell-dependent but IgA-independent and B-cell-independent antigiardial host defenses exist but are less important for controlling infection.

Modeling Long-Term Host Cell-Giardia lamblia Interactions in an In Vitro Co-Culture System

PubMed Central

Fisher, Bridget S.; Estraño, Carlos E.; Cole, Judith A.

2013-01-01

Globally, there are greater than 700,000 deaths per year associated with diarrheal disease. The flagellated intestinal parasite, Giardia lamblia, is one of the most common intestinal pathogens in both humans and animals throughout the world. While attached to the gastrointestinal epithelium, Giardia induces epithelial cell apoptosis, disrupts tight junctions, and increases intestinal permeability. The underlying cellular and molecular mechanisms of giardiasis, including the role lamina propria immune cells, such as macrophages, play in parasite control or clearance are poorly understood. Thus far, one of the major obstacles in ascertaining the mechanisms of Giardia pathology is the lack of a functionally relevant model for the long-term study of the parasite in vitro. Here we report on the development of an in vitro co-culture model which maintains the basolateral-apical architecture of the small intestine and allows for long-term survival of the parasite. Using transwell inserts, Caco-2 intestinal epithelial cells and IC-21 macrophages are co-cultured in the presence of Giardia trophozoites. Using the developed model, we show that Giardia trophozoites survive over 21 days and proliferate in a combination media of Caco-2 cell and Giardia medium. Giardia induces apoptosis of epithelial cells through caspase-3 activation and macrophages do not abrogate this response. Additionally, macrophages induce Caco-2 cells to secrete the pro-inflammatory cytokines, GRO and IL-8, a response abolished by Giardia indicating parasite induced suppression of the host immune response. The co-culture model provides additional complexity and information when compared to a single-cell model. This model will be a valuable tool for answering long-standing questions on host-parasite biology that may lead to discovery of new therapeutic interventions. PMID:24312526

Identification of Giardia lamblia and the human infectious-species of Cryptosporidium in drinking water resources in Western Saudi Arabia by nested-PCR assays.

PubMed

Hawash, Y; Ghonaim, M; Hussein, Y; Alhazmi, A; Alturkistani, A

2015-06-01

The presence of Cryptosporidium and/or Giardia in drinking water represents a major public health problem. This study was the first report concerned with the occurrence of these protozoa in drinking water in Saudi Arabia. The study was undertaken in Al-Taif, a high altitude region, Western Saudi Arabia. Eight underground wells water, six desalinated water and five domestic brands of bottled water samples, 10 liter each, were monthly collected between May 2013 and April 2014. All samples (n = 228), were processed using an automated wash/elution station (IDEXX Laboratories, Inc.). Genomic DNA was directly isolated and purified from samples concentrates with QIAamp® Stool Mini Kit (Qiagen). The target protozoan DNA sequences were amplified using two previously published nested-PCR protocols. Of all the analyzed water, 31 samples (≈14%) were found contaminated with the target protozoa. Giardia lamblia was detected in ≈10% (7/72) of desalinated water and in ≈9% (9/96) of wells water. On the other hand, Cryptosporidium was identified in ≈8% (8/72) of desalinated water and in ≈7% (7/96) of wells water. All bottled water samples (n = 60) were (oo)cysts-free. Protozoan (oo)cysts were more frequently identified in water samples collected in the spring than in other seasons. The methodology established in our study proved sensitive, cost-effective and is amenable for future automation or semi-automation. For better understanding of the current situation that represent an important health threat to the local inhabitants, further studies concerned with (oo)cyst viability, infectivity, concentration and genotype identification are recommended.

A genomic survey of the fish parasite Spironucleus salmonicida indicates genomic plasticity among diplomonads and significant lateral gene transfer in eukaryote genome evolution

PubMed Central

Andersson, Jan O; Sjögren, Åsa M; Horner, David S; Murphy, Colleen A; Dyal, Patricia L; Svärd, Staffan G; Logsdon, John M; Ragan, Mark A; Hirt, Robert P; Roger, Andrew J

2007-01-01

Background Comparative genomic studies of the mitochondrion-lacking protist group Diplomonadida (diplomonads) has been lacking, although Giardia lamblia has been intensively studied. We have performed a sequence survey project resulting in 2341 expressed sequence tags (EST) corresponding to 853 unique clones, 5275 genome survey sequences (GSS), and eleven finished contigs from the diplomonad fish parasite Spironucleus salmonicida (previously described as S. barkhanus). Results The analyses revealed a compact genome with few, if any, introns and very short 3' untranslated regions. Strikingly different patterns of codon usage were observed in genes corresponding to frequently sampled ESTs versus genes poorly sampled, indicating that translational selection is influencing the codon usage of highly expressed genes. Rigorous phylogenomic analyses identified 84 genes – mostly encoding metabolic proteins – that have been acquired by diplomonads or their relatively close ancestors via lateral gene transfer (LGT). Although most acquisitions were from prokaryotes, more than a dozen represent likely transfers of genes between eukaryotic lineages. Many genes that provide novel insights into the genetic basis of the biology and pathogenicity of this parasitic protist were identified including 149 that putatively encode variant-surface cysteine-rich proteins which are candidate virulence factors. A number of genomic properties that distinguish S. salmonicida from its human parasitic relative G. lamblia were identified such as nineteen putative lineage-specific gene acquisitions, distinct mutational biases and codon usage and distinct polyadenylation signals. Conclusion Our results highlight the power of comparative genomic studies to yield insights into the biology of parasitic protists and the evolution of their genomes, and suggest that genetic exchange between distantly-related protist lineages may be occurring at an appreciable rate in eukaryote genome evolution. PMID:17298675

Etiology of Childhood Diarrhea Following Rotavirus Vaccine Introduction: A Prospective, Population-Based Study in Nicaragua

PubMed Central

Becker-Dreps, Sylvia; Bucardo, Filemon; Vilchez, Samuel; Zambrana, Luis Enrique; Liu, Lan; Weber, David J.; Peña, Rodolfo; Barclay, Leslie; Vinjé, Jan; Hudgens, Michael G.; Nordgren, Johan; Svensson, Lennart; Morgan, Douglas R.; Espinoza, Félix; Paniagua, Margarita

2014-01-01

Background Nicaragua was the first developing nation to implement routine immunization with the pentavalent rotavirus vaccine (RV5). In this RV5-immunized population, understanding infectious etiologies of childhood diarrhea is necessary to direct diarrhea treatment and prevention efforts. Methods We followed a population-based sample of children less than 5 years in León, Nicaragua for diarrhea episodes through household visits. Information was obtained on RV5 history and sociodemographics. Stool samples collected during diarrhea episodes and among healthy children underwent laboratory analysis for viral, bacterial, and parasitic enteropathogens. Detection frequency and incidence of each enteropathogen was calculated. Results The 826 children in the cohort experienced 677 diarrhea episodes during 607.5 child-years of exposure time (1.1 episodes per child-year). At least one enteropathogen was detected among 61.1% of the 337 diarrheal stools collected. The most common enteropathogens among diarrheal stools were: norovirus (20.4%), sapovirus (16.6%), enteropathogenic Escherichia coli (EPEC, 11.3%), Entamoeba histolytica/dispar (8.3%), Giardia lamblia (8.0%), and enterotoxigenic E.coli (ETEC, 7.7%), with rotavirus detected among 5.3% of diarrheal stools. EPEC and ETEC were frequently detected among stools from healthy children. Among children with diarrhea, norovirus was more commonly detected among younger children (< 2 years) and G. lamblia was more commonly detected among older children (2-4 years). The mean age of rotavirus detection was 34.6 months. Conclusions In this Central American community following RV5 introduction, rotavirus was not commonly detected among children with diarrhea. Prevention and appropriate management of norovirus and sapovirus should be considered to further reduce the burden of diarrheal disease. PMID:24879131

Redox Pathways as Drug Targets in Microaerophilic Parasites.

PubMed

Leitsch, David; Williams, Catrin F; Hrdý, Ivan

2018-05-25

The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia jointly cause hundreds of millions of infections in humans every year. Other microaerophilic parasites such as Tritrichomonas foetus and Spironucleus spp. pose a relevant health problem in veterinary medicine. Unfortunately, vaccines against these pathogens are unavailable, but their microaerophilic lifestyle opens opportunities for specifically developed chemotherapeutics. In particular, their high sensitivity towards oxygen can be exploited by targeting redox enzymes. This review focusses on the redox pathways of microaerophilic parasites and on drugs, either already in use or currently in the state of development, which target these pathways. Copyright © 2018 Elsevier Ltd. All rights reserved.

Intestinal parasitic infections and its association with undernutrition and CD4 T cell levels among HIV/AIDS patients on HAART in Butajira, Ethiopia.

PubMed

Gedle, Dereje; Kumera, Gemechu; Eshete, Tewodros; Ketema, Kasahun; Adugna, Haweni; Feyera, Fetuma

2017-05-15

Intestinal parasitic infections and HIV/AIDS have been the major public health problems and remain a vital cause of morbidity and mortality in developing countries. Both problems are linked in a vicious cycle. The magnitude of intestinal parasites was prevalent among people living with HIV/AIDS even in the HAART era. However, the pertinent risk factors associated with intestinal parasites among HIV/AIDS patients were not well investigated in Ethiopia particularly at Butajira town. Therefore, the aim of this study was to determine the prevalence of intestinal parasites and associated risk factors among HIV/AIDS patients on HAART in Butajira, Ethiopia. A cross-sectional study was conducted, and a total of 323 study subjects was involved in the study. A systematic random sampling technique was used to select each participant during data collection. Stool specimen was collected and processed using direct wet mount, formol-ether concentration technique, and modified Ziehl-Neelson staining techniques to identify both common and opportunistic intestinal parasites. Structured questionnaire was used to collect socio-demographic, environmental, clinical, and nutritional data. Both bivariate and multivariate logistic regression analyses were used to assess the association of various explanatory factors on intestinal parasites. P value ≤0.05 at 95% CI was considered statistically significant. The overall prevalence of intestinal parasites was 35.9% (95% CI 31.0-40.9%). Protozoa's (Entanmoeba histolytica/dispar trophozoite, E. histolytica/dispar cyst, Giardia lamblia trophozoite, and G. lamblia cyst), helminths (Tanea species, Ascaris lumbricoides, Strongyloid stercoralis, Hookworm species and H. nana), and opportunistic intestinal parasites (Cryptosporidium parvum, Isospora belli) were observed in 57 (17.1%), 46 (14.4%), and 28 (8.7%) study participants respectively. Multivariate logistic regression analysis revealed that the presence of animals (AOR 6. 14; 95% CI 3.13, 12.0); using river water (AOR 4.87; 95% CI 1.14, 20.7); undernutrition (AOR 2.59; 95% CI 1.36-4.95); and level of immunosuppression (AOR 4.02; 95% CI 1.78-9.05 and AOR 2.84; 95% CI 1.37-5.89) were significantly associated with intestinal parasites. The prevalence of intestinal parasites found to be higher among HIV/AIDS patients receiving HAART at Butajira Hospital, southern Ethiopia. Presence of animals, using river water, lower CD4 T cell count, and undernutrition were significant factors affecting intestinal parasites. Therefore, consistent detection of intestinal parasites and deworming of patients should be performed as well as improving health education on personal hygiene, avoiding contact with pit or domestic animals, and using safe or treated water. Furthermore, improving nutritional support and household food access are recommended.

Intestinal parasitosis in school children of Lalitpur district of Nepal

PubMed Central

2013-01-01

Background Enteric parasites are the most common cause of parasitic diseases and cause significant morbidity and mortality, particularly in developing countries like Nepal. The objective of this study was to estimate the prevalence and risk factors of intestinal parasitic infections among school going children of Lalitpur district of Nepal. Methods A total of 1392 stool samples were collected from school children of two government, two private and two community schools of the same district. The stool samples were examined for evidence of parasitic infections by direct microscopy and confirmed by concentration methods (formal ether sedimentation technique or floatation technique by using Sheather’s sugar solution). Modified Ziehl-Neelsen (ZN) staining was performed for the detection of coccidian parasites. Results Prevalence of intestinal parasitosis was found to be 16.7%. The highest prevalence rate was seen with Giardia lamblia (7.4%) followed by Entamoeba histolytica (3.4%) and Cyclospora cayetanensis (1.6%). Children aged 11–15 years and the ones belonging to family of agriculture workers were most commonly affected. Hand washing practice and type of drinking water also showed significant difference. Conclusions The burden of parasitic infections among the school children, coupled with the poor sanitary conditions in the schools, should be regarded as an issue of public health priority and demands for effective school health programs involving periodic health education and screening. PMID:24207086

[The frequency of giardiasis in various children's environment].

PubMed

Pikiewicz-Koch, A

1999-01-01

Giardiasis is an intestinal parastic disease, occurring in many world regions. Its incidence is variable and depends on such factors as studied population and diagnostic methods. In this study the incidence of Giardiasis was assessed in children living in various environments and living conditions. Stool examination was made using microscopic and immunoenzymatic methods. Among 208 examined children 42 (20.2%) were infected with Giardia lamblia. Giardiasis was the most common in children living in orphanage--41.4%. Incidence of Giardiasis among children from day--care centers was the lowest--3.7%. Children aged 12-14 years were infected in 42.7% and aged 0-2 years only in 12.5%. There was no significant difference between boys and girls.

Rapid detachment of Giardia lamblia trophozoites as a mechanism of antimicrobial action of the isoflavone formononetin

PubMed Central

Lauwaet, Tineke; Andersen, Yolanda; Van de Ven, Liesbeth; Eckmann, Lars; Gillin, Frances D.

2010-01-01

Objectives Attachment to the small intestinal mucosa is crucial for initiating and maintaining Giardia infection. We tested the effect of isoflavones on Giardia attachment. Methods We evaluated the effect of formononetin on trophozoite attachment to glass, to intestinal epithelial cell layers in vitro and to murine small intestinal explants, and on the intestinal load in mice. Results We found that the isoflavone formononetin inhibits both attachment and flagellar motility within minutes and reduces the trophozoite load of Giardia in mice within 1.5 h after treatment. Conclusions The antigiardial activity of formononetin is at least partially due to its capacity to rapidly detach trophozoites. PMID:20067984

Rational Design Synthesis and Evaluation of First Generation Inhibitors of the Giardia Lamblia Fructose-1 6-biphosphate Aldolase

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

Z Li; Z Liu; D Cho

2011-12-31

Inhibitors of the Giardia lamblia fructose 1,6-bisphosphate aldolase (GlFBPA), which transforms fructose 1,6-bisphosphate (FBP) to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, were designed based on 3-hydroxy-2-pyridone and 1,2-dihydroxypyridine scaffolds that position two negatively charged tetrahedral groups for interaction with substrate phosphate binding residues, a hydrogen bond donor to the catalytic Asp83, and a Zn{sup 2+} binding group. The inhibition activities for the GlFBPA catalyzed reaction of FBP of the prepared alkyl phosphonate/phosphate substituted 3-hydroxy-2-pyridinones and a dihydroxypyridine were determined. The 3-hydroxy-2-pyridone inhibitor 8 was found to bind to GlFBPA with an affinity (K{sub i} = 14 {micro}M) that is comparable tomore » that of FBP (K{sub m} = 2 {micro}M) or its inert analog TBP (K{sub i} = 1 {micro}M). The X-ray structure of the GlFBPA-inhibitor 8 complex (2.3 {angstrom}) shows that 8 binds to the active site in the manner predicted by in silico docking with the exception of coordination with Zn{sup 2+}. The observed distances and orientation of the pyridone ring O=C-C-OH relative to Zn{sup 2+} are not consistent with a strong interaction. To determine if Zn{sup 2+} coordination occurs in the GlFBPA-inhibitor 8 complex in solution, EXAFS spectra were measured. A four coordinate geometry comprised of the three enzyme histidine ligands and an oxygen atom from the pyridone ring O=C-C-OH was indicated. Analysis of the Zn{sup 2+} coordination geometries in recently reported structures of class II FBPAs suggests that strong Zn{sup 2+} coordination is reserved for the enediolate-like transition state, accounting for minimal contribution of Zn{sup 2+} coordination to binding of 8 to GlFBPA.« less

Rational design, synthesis and evaluation of first generation inhibitors of the Giardia lamblia fructose-1,6-biphosphate aldolase.

PubMed

Li, Zhimin; Liu, Zhengang; Cho, Dae Won; Zou, Jiwen; Gong, Maozhen; Breece, Robert M; Galkin, Andrey; Li, Ling; Zhao, Hong; Maestas, Gabriel D; Tierney, David L; Herzberg, Osnat; Dunaway-Mariano, Debra; Mariano, Patrick S

2011-04-01

Inhibitors of the Giardia lamblia fructose 1,6-bisphosphate aldolase (GlFBPA), which transforms fructose 1,6-bisphosphate (FBP) to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, were designed based on 3-hydroxy-2-pyridone and 1,2-dihydroxypyridine scaffolds that position two negatively charged tetrahedral groups for interaction with substrate phosphate binding residues, a hydrogen bond donor to the catalytic Asp83, and a Zn(2+) binding group. The inhibition activities for the GlFBPA catalyzed reaction of FBP of the prepared alkyl phosphonate/phosphate substituted 3-hydroxy-2-pyridinones and a dihydroxypyridine were determined. The 3-hydroxy-2-pyridone inhibitor 8 was found to bind to GlFBPA with an affinity (K(i)=14μM) that is comparable to that of FBP (K(m)=2μM) or its inert analog TBP (K(i)=1μM). The X-ray structure of the GlFBPA-inhibitor 8 complex (2.3Å) shows that 8 binds to the active site in the manner predicted by in silico docking with the exception of coordination with Zn(2+). The observed distances and orientation of the pyridone ring O=C-C-OH relative to Zn(2+) are not consistent with a strong interaction. To determine if Zn(2+)coordination occurs in the GlFBPA-inhibitor 8 complex in solution, EXAFS spectra were measured. A four coordinate geometry comprised of the three enzyme histidine ligands and an oxygen atom from the pyridone ring O=C-C-OH was indicated. Analysis of the Zn(2+) coordination geometries in recently reported structures of class II FBPAs suggests that strong Zn(2+) coordination is reserved for the enediolate-like transition state, accounting for minimal contribution of Zn(2+) coordination to binding of 8 to GlFBPA. Copyright © 2010 Elsevier Inc. All rights reserved.

High malnutrition rate in Venezuelan Yanomami compared to Warao Amerindians and Creoles: significant associations with intestinal parasites and anemia.

PubMed

Verhagen, Lilly M; Incani, Renzo N; Franco, Carolina R; Ugarte, Alejandra; Cadenas, Yeneska; Sierra Ruiz, Carmen I; Hermans, Peter W M; Hoek, Denise; Campos Ponce, Maiza; de Waard, Jacobus H; Pinelli, Elena

2013-01-01

Children in rural areas experience the interrelated problems of poor growth, anemia and parasitic infections. We investigated the prevalence of and associations between intestinal helminth and protozoan infections, malnutrition and anemia in school-age Venezuelan children. This cross-sectional study was conducted in 390 children aged 4-16 years from three rural areas of Venezuela: the Amazon Region, Orinoco Delta and Carabobo State. Stool samples were collected for direct parasitic examinations. Anthropometric indicators of chronic (height-for-age Z score) and acute (weight-for-height and Body Mass Index (BMI)-for-age Z score in respectively children under 5 years of age and children aged 5 years and above) malnutrition were calculated. Multivariate linear and logistic regression models were built to determine factors associated with nutritional status and polyparasitism. Hookworm and Strongyloides stercoralis prevalences were highest in children from the Amazon rainforest (respectively 72% and 18%) while children from the Orinoco Delta and Carabobo State showed higher rates of Ascaris lumbricoides (respectively 28% and 37%) and Trichuris trichiura (40% in both regions). The prevalence of Giardia lamblia infection was not significantly different between regions (average: 18%). Anemia prevalence was highest in the Amazon Region (24%). Hemoglobin levels were significantly decreased in children with a hookworm infection. Malnutrition was present in respectively 84%, 30% and 13% of children from the Amazon Region, Orinoco Delta and Carabobo State. In multivariate analysis including all regions, G. lamblia and helminth infections were significantly and negatively associated with respectively height-for-age and weight-for-height/BMI-for-age Z scores. Furthermore, hemoglobin levels were positively associated with the height-for-age Z score (0.11, 95% CI 0.02 - 0.20). In rural populations in Venezuela helminthiasis and giardiasis were associated with acute and chronic nutritional status respectively. These data highlight the need for an integrated approach to control transmission of parasites and improve the health status of rural Venezuelan children.

High Malnutrition Rate in Venezuelan Yanomami Compared to Warao Amerindians and Creoles: Significant Associations WITH Intestinal Parasites and Anemia

PubMed Central

Verhagen, Lilly M.; Incani, Renzo N.; Franco, Carolina R.; Ugarte, Alejandra; Cadenas, Yeneska; Sierra Ruiz, Carmen I.; Hermans, Peter W. M.; Hoek, Denise; Campos Ponce, Maiza; de Waard, Jacobus H.; Pinelli, Elena

2013-01-01

Background Children in rural areas experience the interrelated problems of poor growth, anemia and parasitic infections. We investigated the prevalence of and associations between intestinal helminth and protozoan infections, malnutrition and anemia in school-age Venezuelan children. Methods This cross-sectional study was conducted in 390 children aged 4-16 years from three rural areas of Venezuela: the Amazon Region, Orinoco Delta and Carabobo State. Stool samples were collected for direct parasitic examinations. Anthropometric indicators of chronic (height-for-age Z score) and acute (weight-for-height and Body Mass Index (BMI)-for-age Z score in respectively children under 5 years of age and children aged 5 years and above) malnutrition were calculated. Multivariate linear and logistic regression models were built to determine factors associated with nutritional status and polyparasitism. Results Hookworm and Strongyloides stercoralis prevalences were highest in children from the Amazon rainforest (respectively 72% and 18%) while children from the Orinoco Delta and Carabobo State showed higher rates of Ascaris lumbricoides (respectively 28% and 37%) and Trichuris trichiura (40% in both regions). The prevalence of Giardia lamblia infection was not significantly different between regions (average: 18%). Anemia prevalence was highest in the Amazon Region (24%). Hemoglobin levels were significantly decreased in children with a hookworm infection. Malnutrition was present in respectively 84%, 30% and 13% of children from the Amazon Region, Orinoco Delta and Carabobo State. In multivariate analysis including all regions, G. lamblia and helminth infections were significantly and negatively associated with respectively height-for-age and weight-for-height/BMI-for-age Z scores. Furthermore, hemoglobin levels were positively associated with the height-for-age Z score (0.11, 95% CI 0.02 - 0.20). Conclusions In rural populations in Venezuela helminthiasis and giardiasis were associated with acute and chronic nutritional status respectively. These data highlight the need for an integrated approach to control transmission of parasites and improve the health status of rural Venezuelan children. PMID:24143243

Intestinal Parasitic Infections in HIV Infected and Non-Infected Patients in a Low HIV Prevalence Region, West-Cameroon

PubMed Central

Nkenfou, Céline Nguefeu; Nana, Christelle Tafou; Payne, Vincent Khan

2013-01-01

The magnitude of intestinal parasitic infection in acquired immunodeficiency syndrome patients requires careful consideration in the developing world where poor nutrition is associated with poor hygiene and several tropical diseases. However, there have been very few studies addressing this issue in Cameroon. This study was conducted to determine the prevalence of intestinal parasitosis in HIV/AIDS patients in Dschang -Cameroon. Stool and blood specimens from HIV/AIDS patients and control group were screened respectively for intestinal parasites and for HIV antibodies. Intestinal parasites were identified using direct microscopy, formalin-ether concentration and Ziehl Neelsen methods. Out of 396 participants recruited among patients consulting at hospital, 42 (10.6%) were HIV positive, thirty of them treatment naïve. The overall prevalence of intestinal parasites was 14.64%. Out of 42 HIV/AIDS patients, 59.5% (25/42) were infected with intestinal parasites, while only 9.32% (33/354) of the HIV negative patients were infected with intestinal parasites. The parasites detected in our study population included Crystosporidium parvum (2.53%), Entamoeba histolytica (7.52%), Entamoeba coli (4.04%), Giardia lamblia (0.25%), Trichuris trichura (0.25%), Strongyloides stercoralis (0.25%) and Taenia spp. (0.25%). In the HIV infected group, Crystosporidium parvum (19.04%), Entamoeba histolytica (19.04%), Entamoeba coli (21.42%), Giardia lamblia (2.38%), Strongyloides stercoralis (0.25%) and Taenia spp. (0.25%) were found. Crystosporidium parvum was found to be significantly higher in HIV/AIDS patients than in controls (P<0.05). Multivariate analysis showed that the HIV status and the quality of water were the major risk factors for intestinal parasitosis. Routine examinations of stool samples for parasites would significantly benefit the HIV patients by contributing in reducing morbidity and improving the efficiency of antiretroviral treatment. Even after the introduction of free anti-retroviral drugs, opportunistic intestinal infections are still a threat. HIV patients should be screened routinely for intestinal parasites and treated for their overall well being. PMID:23451283

Crystal structure of a macrophage migration inhibitory factor from Giardia lamblia

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

Buchko, Garry W.; Abendroth, Jan; Robinson, Howard

2013-06-15

Macrophage migration inhibitory factor (MIF) is a eukaryotic cytokine that affects a broad spectrum of immune responses and its activation/inactivation is associated with numerous diseases. During protozoan infections MIF is not only expressed by the host, but, has also been observed to be expressed by some parasites and released into the host. To better understand the biological role of parasitic MIF proteins, the crystal structure of the MIF protein from Giardia lamblia (Gl-MIF), the etiological agent responsible for giardiasis, has been determined at 2.30 Å resolution. The 114-residue protein adopts an α/β fold consisting of a four-stranded β-sheet with twomore » anti-parallel α-helices packed against a face of the β-sheet. An additional short β-strand aligns anti-parallel to β4 of the β-sheet in the adjacent protein unit to help stabilize a trimer, the biologically relevant unit observed in all solved MIF crystal structures to date, and form a discontinuous β-barrel. The structure of Gl-MIF is compared to the MIF structures from humans (Hs-MIF) and three Plasmodium species (falciparum, berghei, and yoelii). The structure of all five MIF proteins are generally similar with the exception of a channel that runs through the center of each trimer complex. Relative to Hs-MIF, there are differences in solvent accessibility and electrostatic potential distribution in the channel of Gl-MIF and the Plasmodium-MIFs due primarily to two “gate-keeper” residues in the parasitic MIFs. For the Plasmodium MIFs the gate-keeper residues are at positions 44 (Y==>R) and 100 (V==>D) and for Gl-MIF it is at position 100 (V==>R). If these gate-keeper residues have a biological function and contribute to the progression of parasitemia they may also form the basis for structure-based drug design targeting parasitic MIF proteins.« less

Investigation of zoonotic infections among Auckland Zoo staff: 1991-2010.

PubMed

Forsyth, M B; Morris, A J; Sinclair, D A; Pritchard, C P

2012-12-01

Investigation was undertaken to assess the occurrence of zoonotic infection among staff at Auckland Zoological Park, New Zealand, in 1991, 2002 and 2010. Serial cross-sectional health surveys in 1991, 2002 and 2010 comprising a health questionnaire, and serological, immunological and microbiological analysis for a range of potential zoonotic infections were performed. Laboratory results for zoo animals were also reviewed for 2004-2010 to assess the occurrence of potential zoonotic infections. Veterinary clinic, animal handler, grounds, maintenance and administrative staff participated in the surveys, with 49, 42 and 46 participants in the 1991, 2002 and 2010 surveys, respectively (29% of total zoo staff in 2010). A small number of staff reported work-related infections, including erysipelas (1), giardiasis (1) and campylobacteriosis (1). The seroprevalence of antibodies to hepatitis A virus and Toxoplasma gondii closely reflected those in the Auckland community. No carriage of hepatitis B virus (HBV) was detected, and most of those with anti-HBV antibodies had been vaccinated. Few staff had serological evidence of past leptospiral infection. Three veterinary clinic staff had raised Chlamydophila psittaci antibodies, all < 1 : 160 indicating past exposure. Two staff (in 1991) had asymptomatic carriage of Giardia lamblia and one person (in 2010) had a dermatophyte infection. After 1991, positive tests indicating exposure to Mycobacterium tuberculosis were < 10%, comparable to the general New Zealand population. Zoo animals had infections with potential zoonotic agents, including G. lamblia, Salmonella spp., Campylobacter spp. and T. gondii, although the occurrence was low. Zoonotic agents pose an occupational risk to zoo workers. While there was evidence of some zoonotic transmission at Auckland Zoo, this was uncommon and risks appear to be adequately managed under current policies and procedures. Nevertheless, ongoing assessment of risk factors is needed as environmental, human and animal disease and management factors change. Policies and procedures should be reviewed periodically in conjunction with disease monitoring results for both animals and staff to minimise zoonotic transmission. © 2012 Blackwell Verlag GmbH.

sequence of Gl-MIF and the other Crystal structure of a macrophage migration inhibitory factor from Giardia lamblia

PubMed Central

Abendroth, Jan; Robinson, Howard; Zhang, Yanfeng; Hewitt, Stephen N.; Edwards, Thomas E.; Van Voorhis, Wesley C.; Myler, Peter J.

2013-01-01

Macrophage migration inhibitory factor (MIF) is a eukaryotic cytokine that affects a broad spectrum of immune responses and its activation/inactivation is associated with numerous diseases. During protozoan infections MIF is not only expressed by the host, but, has also been observed to be expressed by some parasites and released into the host. To better understand the biological role of parasitic MIF proteins, the crystal structure of the MIF protein from Giardia lamblia (Gl-MIF), the etiological agent responsible for giardiasis, has been determined at 2.30 Å resolution. The 114-residue protein adopts an α/β fold consisting of a four-stranded β-sheet with two anti-parallel α-helices packed against a face of the β-sheet. An additional short β-strand aligns anti-parallel to β4 of the β-sheet in the adjacent protein unit to help stabilize a trimer, the biologically relevant unit observed in all solved MIF crystal structures to date, and form a discontinuous β-barrel. The structure of Gl-MIF is compared to the MIF structures from humans (Hs-MIF) and three Plasmodium species (falciparum, berghei, and yoelii). The structure of all five MIF proteins are generally similar with the exception of a channel that runs through the center of each trimer complex. Relative to Hs-MIF, there are differences in solvent accessibility and electrostatic potential distribution in the channel of Gl-MIF and the Plasmodium-MIFs due primarily to two “gate-keeper” residues in the parasitic MIFs. For the Plasmodium MIFs the gate-keeper residues are at positions 44 (Y⇒R) and 100 (V⇒D) and for Gl-MIF it is at position 100 (V⇒R). If these gate-keeper residues have a biological function and contribute to the progression of parasitemia they may also form the basis for structure-based drug design targeting parasitic MIF proteins. PMID:23709284

INTESTINAL PARASITES IN DIABETIC PATIENTS IN SOHAG UNIVERSITY HOSPITALS, EGYPT.

PubMed

Elnadi, Nada A; Hassanien, Hassan A; Ahmad, Amal M; Abd Ellah, Asmaa K

2015-08-01

Intestinal parasites usually create benign diseases, though they may induce complications with high morbidity and mortality to the immunocompromised, including diabetic patients. The study detected the prevalence of intestinal parasitic infections in diabetic patients, comparing to non-diabetic controls and other parameters. A total of 100 fecal samples were collected from diabetic patients at the outpatient clinic of Sohag University Hospitals and another 100 from cross matched controls. The samples were examined macroscopically and microscopically by direct smear and different concentration methods then stained by Modified Ziehl-Neelsen Acid fast stain. Glycated hemoglobin (Hb Alc) was measured to detect DM controlled patients. The data were organized, tabulated, and statistically analyzed. Intestinal parasites were found in 25 (25%) cases out of 100 patients in diabetic group and 7(7%) cases out of 100 controls with high significance (P<0.001)). In the diabetic group, Giardia lamblia was detected in 22 cases (22%) and 5 (5%) among controls, Entamoeba histolytica in 7 cases (7%) and 3 (3%) among controls, Hymenolypis nana in 5 cases (5%) and 3 (3%) among controls, Entamoeba coli in 8 patients (8%), Entamoeba hartmanni in 3 cases (3%), Dientamoeba fragilis in a case (1%), Cryptosporidium parvum in 5 cases (5%) and microsporidia in 3 cases (3%). But, E. coli, E. hartmanni, D. fragilis and C. parvum nor microsporidia were detected in controls. The rate of G. lamblia in DM patients compared to controls was high significant (P<0.001). Hymenolepis nana was 5% (5 cases) in diabetic patients compared to 3% (3 cases) in controls. Residence and sex differences were not significant, while age, >10 years showed the highest prevalence (P< 0.003), type I infection rate was significantly higher than type II (P<0.001). DM control was also significantly affected the infection rates (P<0.007 in type I and P< 0.01 in type II).

Ultraviolet disinfection of water for small water supplies

NASA Astrophysics Data System (ADS)

Carlson, D. A.; Seabloom, R. W.; Dewalle, F. B.; Wetzler, T. F.; Engeset, J.

1985-07-01

In the study ultraviolet radiation was considered as an alternative means of disinfection of small drinking water supplies. A major impetus for the study was the large increase in waterborne disease episodes in the United States whose etiologic agent, Giardia lamblia, was found to be highly resistant to conventional chlorination. While the germicidal effect of sunlight has long been known, it has been found that artificial UV radiation with a wavelength of 253.7 nm, can be produced by low pressure mercury vapor lamps. The inactivation of microorganisms by UV radiation is based upon photochemical reactions in DNA which result in errors in the coding system. Inactivation of microorganisms due to exposure to UV is proportional to the intensity multiplied by the time of exposure.

Advances in understanding Giardia: determinants and mechanisms of chronic sequelae

PubMed Central

Sartor, R. Balfour

2015-01-01

Giardia lamblia is a flagellated protozoan that is the most common cause of intestinal parasitic infection in children living in resource-limited settings. The pathogenicity of Giardia has been debated since the parasite was first identified, and clinical outcomes vary across studies. Among recent perplexing findings are diametrically opposed associations between Giardia and acute versus persistent diarrhea and a poorly understood potential for long-term sequelae, including impaired child growth and cognitive development. The mechanisms driving these protean clinical outcomes remain elusive, but recent advances suggest that variability in Giardia strains, host nutritional status, the composition of microbiota, co-infecting enteropathogens, host genetically determined mucosal immune responses, and immune modulation by Giardia are all relevant factors influencing disease manifestations after Giardia infection. PMID:26097735

Detection of Intestinal Protozoa in the Clinical Laboratory

PubMed Central

McHardy, Ian H.; Wu, Max; Shimizu-Cohen, Robyn; Couturier, Marc Roger

2014-01-01

Despite recent advances in diagnostic technology, microscopic examination of stool specimens remains central to the diagnosis of most pathogenic intestinal protozoa. Microscopy is, however, labor-intensive and requires a skilled technologist. New, highly sensitive diagnostic methods have been developed for protozoa endemic to developed countries, including Giardia lamblia (syn. G. intestinalis/G. duodenalis) and Cryptosporidium spp., using technologies that, if expanded, could effectively complement or even replace microscopic approaches. To date, the scope of such novel technologies is limited and may not include common protozoa such as Dientamoeba fragilis, Entamoeba histolytica, or Cyclospora cayetanensis. This minireview describes canonical approaches for the detection of pathogenic intestinal protozoa, while highlighting recent developments and FDA-approved tools for clinical diagnosis of common intestinal protozoa. PMID:24197877

Detection of intestinal protozoa in the clinical laboratory.

PubMed

McHardy, Ian H; Wu, Max; Shimizu-Cohen, Robyn; Couturier, Marc Roger; Humphries, Romney M

2014-03-01

Despite recent advances in diagnostic technology, microscopic examination of stool specimens remains central to the diagnosis of most pathogenic intestinal protozoa. Microscopy is, however, labor-intensive and requires a skilled technologist. New, highly sensitive diagnostic methods have been developed for protozoa endemic to developed countries, including Giardia lamblia (syn. G. intestinalis/G. duodenalis) and Cryptosporidium spp., using technologies that, if expanded, could effectively complement or even replace microscopic approaches. To date, the scope of such novel technologies is limited and may not include common protozoa such as Dientamoeba fragilis, Entamoeba histolytica, or Cyclospora cayetanensis. This minireview describes canonical approaches for the detection of pathogenic intestinal protozoa, while highlighting recent developments and FDA-approved tools for clinical diagnosis of common intestinal protozoa.

Intestinal parasites in a migrant farmworker population.

PubMed

Ungar, B L; Iscoe, E; Cutler, J; Bartlett, J G

1986-03-01

Three hundred thirty-nine migrant worker women and children were screened by single stool examination for intestinal parasites. Infection occurred in 34.2%. Giardia lamblia and Trichuris trichiura were the most common pathogens; Entamoeba coli and Endolimax nana were the most common commensals. Infants under 1 year of age were free of infection. Children between 2 and 5 years old and women between 25 and 35 years old had the highest prevalence. Significantly more Haitians were infected than Mexican-Americans or American blacks. Of ten symptoms, only abdominal pain and gas correlated significantly with infection. This migrant population has a greater prevalence of intestinal parasites than the general American public. Screening by stool examination may be beneficial to diminish the reservoir of infection.

A Retrospective Analysis of the Results of a Five-Year (2005-2009) Parasitological Examination for Common Intestinal Parasites from Bale-Robe Health Center, Robe Town, Southeastern Ethiopia.

PubMed

Chala, Bayissa

2013-01-01

A cross-sectional retrospective survey using the past five years clinical records (2005-2009) was conducted. The study was aimed at assessing the status of common intestinal parasites from Bale-Robe Health Center, Southeastern Ethiopia, in 2009/2010. The survey involved collection of data recorded on intestinal parasite from the health center during 2005-2009. Precoded questionnaires and interviews were also supplemented for knowledge attitude practices survey (KAPs survey) to assess awareness level of treatment seekers. Analysis of the various associations and strength of significant variations among qualitative and quantitative variables were assessed. The results revealed that Entamoeba histolytica (36.1%) and Giardia lamblia (11.0%), both being protozoan parasites were found to be the most prevalent intestinal parasites encountered during 2005-2009. The least prevalent intestinal parasite recorded was Strongyloides stercoralis (1.1%). Most intestinal parasites were detected among age group of 15 years and above than 0-4 and 5-14 years as shown in Table 4. There was a significant correlation between intestinal parasites prevalence and the age of treatment seeking individuals (P < 0.05). A sharp increasing trend of E. histolytica and Ascaris lumbricoides infections was observed owing to low personal and environmental sanitation of the majority of the society. Initiation of health education at different levels could be recommended to mitigate infectious parasites in the area.

Acetate formation in the energy metabolism of parasitic helminths and protists.

PubMed

Tielens, Aloysius G M; van Grinsven, Koen W A; Henze, Katrin; van Hellemond, Jaap J; Martin, William

2010-03-15

Formation and excretion of acetate as a metabolic end product of energy metabolism occurs in many protist and helminth parasites, such as the parasitic helminths Fasciola hepatica, Haemonchus contortus and Ascaris suum, and the protist parasites, Giardia lamblia, Entamoeba histolytica, Trichomonas vaginalis as well as Trypanosoma and Leishmania spp. In all of these parasites acetate is a main end product of their energy metabolism, whereas acetate formation does not occur in their mammalian hosts. Acetate production might therefore harbour novel targets for the development of new anti-parasitic drugs. In parasites, acetate is produced from acetyl-CoA by two different reactions, both involving substrate level phosphorylation, that are catalysed by either a cytosolic acetyl-CoA synthetase (ACS) or an organellar acetate:succinate CoA-transferase (ASCT). The ACS reaction is directly coupled to ATP synthesis, whereas the ASCT reaction yields succinyl-CoA for ATP formation via succinyl-CoA synthetase (SCS). Based on recent work on the ASCTs of F. hepatica, T. vaginalis and Trypanosoma brucei we suggest the existence of three subfamilies of enzymes within the CoA-transferase family I. Enzymes of these three subfamilies catalyse the ASCT reaction in eukaryotes via the same mechanism, but the subfamilies share little sequence homology. The CoA-transferases of the three subfamilies are all present inside ATP-producing organelles of parasites, those of subfamily IA in the mitochondria of trypanosomatids, subfamily IB in the mitochondria of parasitic worms and subfamily IC in hydrogenosome-bearing parasites. Together with the recent characterisation among non-parasitic protists of yet a third route of acetate formation involving acetate kinase (ACK) and phosphotransacetylase (PTA) that was previously unknown among eukaryotes, these recent developments provide a good opportunity to have a closer look at eukaryotic acetate formation. (c) 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

[Czech eponyms in pathology].

PubMed

Steiner, Ivo

2013-01-01

The 24th European Congress of Pathology taking place in Prague is an opportunity to remind our society of the Czech names appearing as eponyms in pathological terminology: Karel Rokitanský - R. protuberance in dermoid cyst; R. thrombogenic theory of atherosclerosis; Mayer - R. - Küster - Hauser - Winckel syndrome (congenital malformation of the vagina and uterus); Václav Treitz - T. duodenal ligament; T. retroperitoneal hernia; T. uremic colitis; Vilém Dušan Lambl - L. excrescences of heart valves; Lamblia (Giardia) intestinalis, and also the foundation of urological cytology; Stanislav Provázek - Prowazek - Halberstädter bodies (trachoma), Rickettsia Prowazeki (typhus fever); Josef Vaněk - V. tumor (gastric inflammatory fibroid polyp), and also discovery of the etiology of pneumocystic pneumonia; Otto Jírovec - Pneumocystis Jiroveci; Blahoslav Bednář - B. tumor (pigmented dermatofibrosarcoma protuberans).

Characterisation of the subtelomeric regions of Giardia lamblia genome isolate WBC6.

PubMed

Prabhu, Anjali; Morrison, Hilary G; Martinez, Charles R; Adam, Rodney D

2007-04-01

Giardia trophozoites are polyploid and have five chromosomes. The chromosome homologues demonstrate considerable size heterogeneity due to variation in the subtelomeric regions. We used clones from the genome project with telomeric sequence at one end to identify six subtelomeric regions in addition to previously identified subtelomeric regions, to study the telomeric arrangement of the chromosomes. The subtelomeric regions included two retroposons, one retroposon pseudogene, and two vsp genes, in addition to the previously identified subtelomeric regions that include ribosomal DNA repeats. The presence of vsp genes in a subtelomeric region suggests that telomeric rearrangements may contribute to the generation of vsp diversity. These studies of the subtelomeric regions of Giardia may contribute to our understanding of the factors that maintain stability, while allowing diversity in chromosome structure.

Prevalence of Irritable Bowel Syndrome and Chronic Fatigue 10 Years After Giardia Infection.

PubMed

Litleskare, Sverre; Rortveit, Guri; Eide, Geir Egil; Hanevik, Kurt; Langeland, Nina; Wensaas, Knut-Arne

2018-03-06

Irritable bowel syndrome (IBS) is a complication that can follow gastrointestinal infection, but it is not clear if patients also develop chronic fatigue. We investigated the prevalence and odds ratio of IBS and chronic fatigue 10 years after an outbreak of Giardia lamblia, compared with a control cohort, and changes in prevalence over time. We performed a prospective follow-up study of 1252 laboratory-confirmed cases of giardiasis (exposed), which developed in Bergen, Norway in 2004. Statistics Norway provided us with information from 2504 unexposed individuals from Bergen, matched by age and sex (controls). Questionnaires were mailed to participants 3, 6, and 10 years after the outbreak. Results from the 3- and 6-year follow-up analyses have been published previously. We report the 10-year data and changes in prevalence among time points, determined by logistic regression using generalized estimating equations. The prevalence of IBS 10 years after the outbreak was 43% (n = 248) among 576 exposed individuals and 14% (n = 94) among 685 controls (adjusted odds ratio for development of IBS in exposed individuals, 4.74; 95% CI, 3.61-6.23). At this time point, the prevalence of chronic fatigue was 26% (n = 153) among 587 exposed individuals and 11% (n = 73) among 692 controls (adjusted odds ratio, 3.01; 95% CI, 2.22-4.08). The prevalence of IBS among exposed persons did not change significantly from 6 years after infection (40%) to 10 years after infection (43%; adjusted odds ratio for the change 1.03; 95% CI, 0.87-1.22). However, the prevalence of chronic fatigue decreased from 31% at 6 years after infection to 26% at 10 years after infection (adjusted odds ratio for the change 0.74; 95% CI, 0.61-0.90). The prevalence of IBS did not change significantly from 6 years after an outbreak of Giardia lamblia infection in Norway to 10 years after. However, the prevalence of chronic fatigue decreased significantly from 6 to 10 years afterward. IBS and chronic fatigue were still associated with giardiasis 10 years after the outbreak. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

Apo And Calcium-Bound Crystal Structures of Alpha-11 Giardin, An Unusual Annexin From 'Giardia Lamblia'

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

Pathuri, P.; Nguyen, E.T.; Svard, S.G.

2007-07-12

Alpha-11 giardin is a member of the multi-gene alpha-giardin family in the intestinal protozoan, Giardia lamblia. This gene family shares an ancestry with the annexin super family, whose common characteristic is calcium-dependent binding to membranes that contain acidic phospholipids. Several alpha giardins are highly expressed during parasite-induced diarrhea in humans. Despite being a member of a large family of proteins, little is known about the function and cellular localization of alpha-11 giardin, although giardins are often associated with the cytoskeleton. It has been shown that Giardia exhibits high levels of alpha-11 giardin mRNA transcript throughout its life cycle; however, constitutivemore » over-expression of this protein is lethal to the parasite. Determining the three-dimensional structure of an alpha-giardin is essential to identifying functional domains shared in the alpha-giardin family. Here we report the crystal structures of the apo and Ca{sup 2+}-bound forms of alpha-11 giardin, the first alpha giardin to be characterized structurally. Crystals of apo and Ca{sup 2+}-bound alpha-11 giardin diffracted to 1.1 angstroms and 2.93 angstroms, respectively. The crystal structure of selenium-substituted apo alpha-11 giardin reveals a planar array of four tandem repeats of predominantly {alpha}-helical domains, reminiscent of previously determined annexin structures, making this the highest-resolution structure of an annexin to date. The apo alpha-11 giardin structure also reveals a hydrophobic core formed between repeats I/IV and II/III, a region typically hydrophilic in other annexins. Surprisingly, the Ca{sup 2+}-bound structure contains only a single calcium ion, located in the DE loop of repeat I and coordinated differently from the two types of calcium sites observed in previous annexin structures. The apo and Ca{sup 2+}-bound alpha-11 giardin structures assume overall similar conformations; however, Ca2+-bound alpha-11 giardin crystallized in a lower-symmetry space group with four molecules in the asymmetric unit. Vesicle-binding studies suggest that alpha-11 giardin, unlike most other annexins, does not bind to vesicles composed of acidic phospholipids in a calcium-dependent manner.« less

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

PubMed

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

2015-07-17

In resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. The study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area. qPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1%) and N. americanus (36.4%) infections. There were 48.6% of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/μL: 0.63 fg/μL, P < 0.001) respectively. qPCR outperformed microscopy by the largest margin in G. lamblia infections (63.6% versus 8.1%, P < 0.05). Polyparasitism was detected more often by qPCR compared to microscopy (64.7% versus 24.2%, P < 0.05). Multi-parallel qPCR is a quantitative molecular diagnostic method for common intestinal parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR.

PubMed

Ribas, Alexis; Jollivet, Chloé; Morand, Serge; Thongmalayvong, Boupha; Somphavong, Silaphet; Siew, Chern-Chiang; Ting, Pei-Jun; Suputtamongkol, Saipin; Saensombath, Viengsaene; Sanguankiat, Surapol; Tan, Boon-Huan; Paboriboune, Phimpha; Akkhavong, Kongsap; Chaisiri, Kittipong

2017-10-01

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

PubMed Central

Ribas, Alexis; Jollivet, Chloé; Morand, Serge; Thongmalayvong, Boupha; Somphavong, Silaphet; Siew, Chern-Chiang; Ting, Pei-Jun; Suputtamongkol, Saipin; Saensombath, Viengsaene; Sanguankiat, Surapol; Tan, Boon-Huan; Paboriboune, Phimpha; Akkhavong, Kongsap; Chaisiri, Kittipong

2017-01-01

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor. PMID:29103267

Treatment of infectious complications of acquired immunodeficiency syndrome.

PubMed

Furio, M M; Wordell, C J

1985-01-01

The infectious complications of the acquired immunodeficiency syndrome (AIDS) are discussed, and the conventional and nonconventional therapies used for these infections are reviewed. The infections most commonly encountered in patients with AIDS are Pneumocystis carinii pneumonia (58%), Candida esophagitis (31%), toxoplasmosis (21%), cytomegalovirus infections (15%), and herpes-simplex virus infections (12%). Pneumocystis carinii pneumonia is the most common life-threatening process in these patients. Trimethoprim-sulfamethoxazole (TMP-SMZ) is considered the drug of choice for its treatment. Oral candidiasis often indicates the progression to AIDS in the high-risk populations of homosexual or bisexual men, intravenous drug abusers, and individuals with hemophilia. Nystatin suspension is commonly used to treat oral candidiasis, while Candida esophagitis demands systemic therapy with ketoconazole. Toxoplasmosis most commonly manifests itself in patients with AIDS as a cerebral mass lesion. The recommended therapy includes sulfadiazine and pyrimethamine. AIDS patients frequently experience protozoal invasion of the intestinal tract with Giardia lamblia, Isospora belli, and Cryptosporidium muris. Various drugs have been tried for these infections, including quinacrine hydrochloride, metronidazole, TMP-SMZ, and spiramycin. Cytomegalovirus (CMV) infections commonly involve the lungs, gastrointestinal tract, eyes, brain, and nervous system. Attempts to treat these disseminated CMV infections with antiviral agents, including acyclovir, have not been successful. However, acyclovir has been found beneficial in the treatment of herpes-simplex virus infections. Multiple infectious complications may occur in patients with AIDS as a result of the cellular-immune deficiency associated with this disease. Until more research is done with AIDS patients, therapy must be based on the data available from the treatment of these infections in immunosuppressed patients without AIDS.

Short communication: Nitazoxanide inhibits HIV viral replication in monocyte-derived macrophages.

PubMed

Gekonge, Bethsebah; Bardin, Matthew C; Montaner, Luis J

2015-02-01

We document the anti-HIV activity of nitazoxanide (NTZ), the first member of the thiazolide class of antiinfective drugs, originally effective against enteritis caused by Cryptosporidium parvum and Giardia lamblia. NTZ has been administered extensively worldwide, with no severe toxicities associated with its use. Here, we show for the first time that NTZ decreases HIV-1 replication in monocyte-derived macrophages (MDM) if present before or during HIV-1 infection. This NTZ effect is associated with downregulation of HIV-1 receptors CD4 and CCR5, and increasing gene expression of host cell anti-HIV resistance factors APOBEC3A/3G and tetherin. As NTZ is already in clinical use for other conditions, this newly described anti-HIV activity in MDM may facilitate innovative intensification strategies against HIV-1 when combined with current antiretroviral drug regimens.

Lensfree super-resolution holographic microscopy using wetting films on a chip

NASA Astrophysics Data System (ADS)

Mudanyali, Onur; Bishara, Waheb; Ozcan, Aydogan

2011-08-01

We investigate the use of wetting films to significantly improve the imaging performance of lensfree pixel super-resolution on-chip microscopy, achieving < 1 μm spatial resolution over a large imaging area of ~24 mm2. Formation of an ultra-thin wetting film over the specimen effectively creates a micro-lens effect over each object, which significantly improves the signal-to-noise-ratio and therefore the resolution of our lensfree images. We validate the performance of this approach through lensfree on-chip imaging of various objects having fine morphological features (with dimensions of e.g., ≤0.5 μm) such as Escherichia coli (E. coli), human sperm, Giardia lamblia trophozoites, polystyrene micro beads as well as red blood cells. These results are especially important for the development of highly sensitive field-portable microscopic analysis tools for resource limited settings.

Drinking-Water Standards and Regulations. Volume 2. Manual for 1982-88

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

Wang, L.K.; Wang, M.H.S.

1988-04-10

The following 11 important documents are compiled for Drinking Water Standards and Regulations: (1) U.S. Environmental Agency Water Programs, National Interim Primary Drinking Water Regulations; (2) New Jersey Safe Drinking Water Act; (3) Summary of New Jersey Drinking Water Standards; (4) U.S. Environmental Protection Agency Safe Drinking Water Act of 1986 Amendments; (5) U.S. Environmental Protection Agency National Primary Drinking Water Standards; (6) Canadian National Health and Welfare Drinking Water Quality Guidelines--Maximum Acceptable Concentrations; (7) U.S. Environmental Protection Agency, National Primary Drinking Water Regulations, Filtration and Disinfection Turbidity, Giardia Lamblia, Viruses, Legionella, and Heterotrophic Bacteria; (8) Public Water Supply Manual--Guidemore » to the Safe Drinking Water Program; (9) Public Water Supply Manual--Emergency Response; (10) U.S. EPA Approved Krofta Chemicals; (11) NY-DOH Approved Krofta Chemicals.« less

The Giardia genome project database.

PubMed

McArthur, A G; Morrison, H G; Nixon, J E; Passamaneck, N Q; Kim, U; Hinkle, G; Crocker, M K; Holder, M E; Farr, R; Reich, C I; Olsen, G E; Aley, S B; Adam, R D; Gillin, F D; Sogin, M L

2000-08-15

The Giardia genome project database provides an online resource for Giardia lamblia (WB strain, clone C6) genome sequence information. The database includes edited single-pass reads, the results of BLASTX searches, and details of progress towards sequencing the entire 12 million-bp Giardia genome. Pre-sorted BLASTX results can be retrieved based on keyword searches and BLAST searches of the high throughput Giardia data can be initiated from the web site or through NCBI. Descriptions of the genomic DNA libraries, project protocols and summary statistics are also available. Although the Giardia genome project is ongoing, new sequences are made available on a bi-monthly basis to ensure that researchers have access to information that may assist them in the search for genes and their biological function. The current URL of the Giardia genome project database is www.mbl.edu/Giardia.

Application of the pentaiodide strong base resin disinfectant to the U.S. space program

NASA Technical Reports Server (NTRS)

Marchin, George L.

1990-01-01

A pentaiodide resin is described which has 70 percent of its weight composed of elemental iodine, has a relatively low iodine residual, and may offer superior disinfection capability for applications on long-duration space vehicles. Such a disinfectant is crucial for use on spacecraft for long periods of time where water would be recycled through various systems. The pentaiodide resin is capable of devitalizing 1 x 10 to the 9th bacteria per ml in aqueous suspension within 10 seconds of contact with the resin bed. A number of organisms have already been tested and the resin continues to prove effective. Resin properties and composition are discussed and a detailed account of the first investigation of the pentaiodide resin as a disinfectant against the intestinal parasite Giardia lamblia is provided.

Novel flashlamp-based time-resolved fluorescence microscope reduces autofluorescence for 30-fold contrast enhancement in environmental samples

NASA Astrophysics Data System (ADS)

Connally, Russell; Veal, Duncan; Piper, James A.

2003-07-01

The abundance of naturally fluorescing components (autofluorophors) encountered in environmentally sourced samples can greatly hinder the detection and identification of fluorescently labeled target using fluorescence microscopy. Time-resolved fluorescence microscopy (TRFM) is a technique that reduces the effects of autofluorescence through precisely controlled time delays. Lanthanide chelates have fluorescence lifetimes many orders of magnitude greater than typical autofluorophors, and persist in their luminescence long after autofluorescence has ceased. An intense short pulse of (UV) light is used to excite fluorescence in the sample and after a short delay period the longer persisting fluorescence from the chelate is captured with an image-intensified CCD camera. The choice of pulsed excitation source for TRFM has a large impact on the price and performance of the instrument. A flashlamp with a short pulse duration was selected for our instrument because of the high spectral energy in the UV region and short pulse length. However, flash output decays with an approximate lifetime of 18μs and the TRFM requires a long-lived chelate to ensure probe fluorescence is still visible after decay of the flash plasma. We synthesized a recently reported fluorescent chelate (BHHCT) and conjugated it to a monoclonal antibody directed against the water-borne parasite Giardia lamblia. Fluorescence lifetime of the construct was determined to be 339μs +/- 14μs and provided a 45-fold enhancement of labeled Giardia over background using a gate delay of 100μs. Despite the sub-optimal decay characteristics of the light pulse, flashlamps have many advantages compared to optical chopper wheels and modulated lasers. Their low cost, lack of vibration, ease of interface and small footprint are important factors to consider in TRFM design.

Time-resolvable fluorescent conjugates for the detection of pathogens in environmental samples containing autofluorescent material

NASA Astrophysics Data System (ADS)

Connally, Russell; Veal, Duncan; Piper, James A.

2003-07-01

Water is routinely monitored for environmental pathogens such a Cryptosporidium and Giardia using immunofluorescence microscopy (IFM). Autofluorescence can greatly diminish an operators capacity to resolve labeled pathogens from non-specific background. Naturally fluorescing components (autofluorophores) encountered in biological samples typically have fluorescent lifetimes (τ) of less than 100 nanoseconds and their emissions may be excluded through use of time-resolved fluorescence microscopy (TRFM). TRFM relies on the large differences in τ between autofluorescent molecules and long-lived lanthanide chelates. In TRFM, targets labeled with a time-resolvable fluorescent immunoconjugate are excited by an intense (UV) light pulse. A short delay is imposed to permit the decay of autofluorescence before capture of luminescence from the excited chelate using an image intensified CCD camera. In our experience, autofluorescence can be reduced to insignificant levels with a consequent 30-fold increase in target visibility using TRFM techniques. We report conjugation of a novel europium chelate to a monoclonal antibody specific for Giardia lamblia and use of the immunoconjugate for TRFM studies. Initial attempts to conjugate the same chelate to a monoclonal antibody directed against Cryptosporidium parvum led to poorly fluorescent constructs that were prone to denature and precipitate. We successfully conjugated BHHCT to anti-mouse polyvalent immunoglobulin and used this construct to overcome the difficulties in direct labeling of the anti-Cryptosporidium antibody. Both Giardia and Cryptosporidium were labeled using the anti-mouse protocol with a subsequent 20-fold and 6.6-fold suppression of autofluorescence respectively. A rapid protocol for conjugating and purifying the immunoconjugate was found and methods of quantifying the fluorescence to protein ratio determined. Performance of our TRFM was dependent on the quality and brightness of the immunoconjugate and optimization of the conjugation process is necessary to reap the full benefit of time-resolved techniques.

Parental involvement and association with adolescents' fruit and vegetable intake at follow-up: Process evaluation results from the multi-component school-based Boost intervention.

PubMed

Jørgensen, Sanne Ellegård; Jørgensen, Thea Suldrup; Aarestrup, Anne Kristine; Due, Pernille; Krølner, Rikke

2016-10-26

Based on the assumption of parental influence on adolescent behavior, multicomponent school-based dietary interventions often include a parental component. The effect of this intervention component is seldom reported and the evidence is inconsistent. We conducted a systematic process evaluation of the parental component and examined whether the leveal of parental involvement in a large multi-component intervention: the Boost study was associated with adolescents' fruit and vegetable (FV) intake at follow-up. The Boost study was targeting FV intake among 1,175 Danish 7 th graders (≈13- year-olds) in the school year 2010/11. The study included a school component: free FV in class and curricular activities; a local community component: fact sheets for sports- and youth clubs; and a parental component: presentation of Boost at a parent-school meeting, 6 newsletters to parents, 3 guided student-parent curricular activities, and a student-parent Boost event. Students whose parent replied to the follow-up survey (n = 347). Questionnaire data from students, parents and teachers at 20 intervention schools. Process evaluation measures: dose delivered, dose received, appreciation and level of parental involvement. Parental involvement was trichotomized into: low/no (0-2 points), medium (3 points) and high (4-6 points). The association between level of parental involvement and self-reported FV intake (24-h recall), was analyzed using multilevel regression analyses. The Boost study was presented at a parent-school meeting at all intervention schools. The dose delivered was low to moderate for the three other parental elements. Most parents appreciated the intervention and talked with their child about Boost (83.5 %). High, medium and low parental involvement was found among 30.5 %, 29.6 % and 39.4 % of the students respectively. Parental involvement was highest among women. More men agreed that the parental newsletters provided new information. Students with a medium and high level of parental involvement ate 47.5 and 95.2 g more FV per day compared to students with low level/no parental involvement (p = 0.02). Students with a high level of parental involvement ate significantly more FV at follow-up compared to students with a low level/no parental involvement. Parental involvement in interventions may improve adolescents' FV intake if challenges of implementation can be overcome. ISRCTN11666034 . Registered 06/01/2012. Retrospectively registered.

High Resolution CryoFESEM of Microbial Surfaces

NASA Astrophysics Data System (ADS)

Erlandsen, Stanley; Lei, Ming; Martin-Lacave, Ines; Dunny, Gary; Wells, Carol

2003-08-01

The outer surfaces of three microorganisms, Giardia lamblia, Enterococcus faecalis, and Proteus mirabilis, were investigated by cryo-immobilization followed by sublimation of extracellular ice and cryocoating with either Pt alone or Pt plus carbon. Cryocoated samples were examined at [minus sign]125°C in either an in-lens field emission SEM or a below-the-lens field emission SEM. Cryocoating with Pt alone was sufficient for low magnification observation, but attempts to do high-resolution imaging resulted in radiolysis and cracking of the specimen surface. Double coating with Pt and carbon, in combination with high resolution backscatter electron detectors, enabled high-resolution imaging of the glycocalyx of bacteria, revealing a sponge-like network over the surface. High resolution examination of bacterial flagella also revealed a periodic substructure. Common artifacts included radiolysis leading to “cracking” of the surface, and insufficient deposition of Pt resulting in the absence of detectable surface topography.

Microbiological and Pharmacological Evaluation of the Micropropagated Rubus liebmannii Medicinal Plant

PubMed Central

Jiménez-Arellanes, Adelina; Cornejo-Garrido, Jorge; Rojas-Bribiesca, Gabriela; Nicasio-Torres, María del Pilar; Said-Fernández, Salvador; Mata-Cárdenas, Benito David; Molina-Salinas, Gloria María; Tortoriello, Jaime; Meckes-Fischer, Mariana

2012-01-01

Rubus liebmannii is an endemic species from Mexico used in traditional medicine primarily to treat dysentery and cough. The in vitro activity against Giardia lamblia and Entamoeba histolytica that produces the ethanolic extract of the aerial parts of the plant led us to expand the pharmacological and phytochemical research of this species. Gastrointestinal disorders including amebiasis remain one of the health problems that need to be addressed and it is of interest to find alternatives that improve their treatment. Also, it is important to emphasize that R. liebmannii grows wild in the country and is not found in abundance; therefore, alternatives that avoid overexploitation of the natural resource are mandatory. Ongoing with the evaluation of the potentialities that R. liebmannii possesses for treating infectious gastrointestinal diseases, the aim of the present study was to evaluate the biological effects and the chemical composition of the micropropagated plant. PMID:22966243

Recent advances in molecular biology of parasitic viruses.

PubMed

Banik, Gouri Rani; Stark, Damien; Rashid, Harunor; Ellis, John T

2014-01-01

The numerous protozoa that can inhabit the human gastro-intestinal tract are known, yet little is understood of the viruses which infect these protozoa. The discovery, morphologic details, purification methods of virus-like particles, genome and proteome of the parasitic viruses, Entamoeba histolytica, Giardia lamblia, Trichomonas vaginalis, and the Eimeria sp. are described in this review. The protozoan viruses share many common features: most of them are RNA or double-stranded RNA viruses, ranging between 5 and 8 kilobases, and are spherical or icosahedral in shape with an average diameter of 30-40 nm. These viruses may influence the function and pathogenicity of the protozoa which they infect, and may be important to investigate from a clinical perspective. The viruses may be used as specific genetic transfection vectors for the parasites and may represent a research tool. This review provides an overview on recent advances in the field of protozoan viruses.

Pathogens in drinking water: Are there any new ones

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

Reasoner, D.J.

1993-01-01

Since 1976 three newly recognized human pathogens have become familiar to the drinking water industry as waterborne disease agents. These are: the legionnaires disease agent, Legionella pneumophila and related species; and two protozoan pathogens, Giardia lamblia and Cryptosporidium parvum, both of which form highly disinfectant resistant cysts that are shed in the feces of infected individuals. The question frequently arises - are there other emerging waterborne pathogens that may pose a human health problem that the drinking water industry will have to deal with. The paper will review the current state of knowledge of the occurrence and incidence of pathogensmore » and opportunistic pathogens other than Legionella, Giardia and Cryptosporidium in treated and untreated drinking water. Bacterial agents that will be reviewed include Aeromonas, Pseudomonas, Campylobacter, Mycobacterium, Yersinia and Plesiomonas. Aspects of detection of these agents including detection methods and feasibility of monitoring will be addressed.« less

In vivo antigiardial activity of three flavonoids isolated of some medicinal plants used in Mexican traditional medicine for the treatment of diarrhea.

PubMed

Barbosa, Elizabeth; Calzada, Fernando; Campos, Rafael

2007-02-12

Mexican traditional medicine uses a great variety of plants in the treatment of gastrointestinal disorders such as diarrhea. In order to understand the properties of some of their chemical constituents, three flavonoids (kaempferol, tiliroside and (-)-epicatechin) isolated from Geranium mexicanum, Cuphea pinetorum, Helianthemum glomeratum, and Rubus coriifolius, were assayed to demonstrate their in vivo antiprotozoal activity; using an experimental infection of Giardia lamblia in suckling female CD-1 mice. Compounds tested showed antigiardial activity with values of ED(50) (micromol/kg) 0.072 for (-)-epicatechin, 2.057 for kaempferol and 1.429 for tiliroside. The most active flavonoid was the (-)-epicatechin, its activity was higher than metronidazole and emetine, drugs used as positive controls. In the case of kaempferol and tiliroside their potency was close to that of the metronidazole, but far less than emetine.

Giardia muris trophozoite antigenic targets for mouse intestinal IgA antibody.

PubMed

Heyworth, M F; Vergara, J A

1994-02-01

The aim of this work was to characterize Giardia muris trophozoite proteins that are targets for intestinal anti-trophozoite IgA in G. muris-infected mice. Intestinal secretions were obtained from immunocompetent BALB/c mice that had been infected with G. muris cysts 4-5 weeks previously and from control uninfected BALB/c mice. Flow cytometry of G. muris trophozoites that had been incubated with intestinal secretions and with fluorescein isothiocyanate-conjugated anti-mouse IgA showed that anti-trophozoite IgA was present in intestinal secretions obtained from infected BALB/c mice. By immunoblotting on G. muris trophozoite proteins separated by one-dimensional gel electrophoresis, this IgA recognized at least one trophozoite protein of molecular mass of approximately 80 kDa. The 80-kDa G. muris protein(s) has a molecular mass similar to that described for cysteine-rich surface proteins of the human parasite Giardia lamblia.

Gastrointestinal parasites of the colobus monkeys of Uganda.

PubMed

Gillespie, Thomas R; Greiner, Ellis C; Chapman, Colin A

2005-06-01

From August 1997 to July 2003, we collected 2,103 fecal samples from free-ranging individuals of the 3 colobus monkey species of Uganda-the endangered red colobus (Piliocolobus tephrosceles), the eastern black-and-white colobus (Colobus guereza), and the Angolan black-and-white colobus (C. angolensis)--to identify and determine the prevalence of gastrointestinal parasites. Helminth eggs, larvae, and protozoan cysts were isolated by sodium nitrate flotation and fecal sedimentation. Coprocultures facilitated identification of helminths. Seven nematodes (Strongyloides fulleborni, S. stercoralis, Oesophagostomum sp., an unidentified strongyle, Trichuris sp., Ascaris sp., and Colobenterobius sp.), 1 cestode (Bertiella sp.), 1 trematode (Dicrocoeliidae), and 3 protozoans (Entamoeba coli, E. histolytica, and Giardia lamblia) were detected. Seasonal patterns of infection were not apparent for any parasite species infecting colobus monkeys. Prevalence of S. fulleborni was higher in adult male compared to adult female red colobus, but prevalence did not differ for any other shared parasite species between age and sex classes.

Opportunistic parasites among immunosuppressed children in Minia District, Egypt.

PubMed

Abdel-Hafeez, Ekhlas H; Ahmad, Azza K; Ali, Basma A; Moslam, Fadia A

2012-03-01

A total of 450 stool samples were collected from inpatient and outpatient clinics of Pediatric Department, Minia University Hospital, Minia District, Egypt. Two groups of patients were studied, including 200 immunosuppressed and 250 immunocompetent children. Stool samples were subjected to wet saline and iodine mounts. A concentration technique (formol-ether sedimentation method) was carried out for stool samples diagnosed negative by wet saline and iodine mounts. Samples were stained by 2 different methods; acid fast stain (modified Ziehl-Neelsen stain) and Giemsa stain. Total 188 cases (94%) were diagnosed positive for parasitic infections among immunosuppressed children, whereas 150 cases (60%) were positive in immunocompetent children (P<0.0001). The most common protozoan infection in immunosuppressed group was Cryptosporidium parvum (60.2%), followed by Blastocystis hominis (12.1%), Isospora belli (9.7%), and Cyclospora caytenensis (7.8%). On the other hand, Entamoeba histolytica (24.6%) and Giardia lamblia (17.6%) were more common than other protozoans in immunocompetent children.

Parasitic causes of prolonged diarrhoea in travellers - diagnosis and management.

PubMed

Slack, Andrew

2012-10-01

Prolonged infectious diarrhoea in the returning traveller is generally caused by protozoal and occasionally by helminth parasites. This article provides a framework for the diagnosis, management and prevention of the diseases that cause persistent diarrhoea in the traveller. A large proportion of disease is caused by Giardia lamblia, Cryptosporidium parvum and Entamoeba histolytica. However, given the ease of travel with comorbid conditions such as human immunodeficiency virus, there is an expanding list of organisms that can cause persistent diarrhoea. An awareness of the likely aetiological agents and their clinical features enables a more effective diagnosis and management of the patient's condition using an appropriate antiparasitic agent. Prevention strategies need to be initiated before travel and should consist of simple but memorable advice. Noninfectious causes of diarrhoea should be considered as diarrhoea can be a prominent feature of conditions such as hyperthyroidism or coeliac disease.

Hymenolepis nana: a common cause of paediatric diarrhoea in urban slum dwellers in India.

PubMed

Mirdha, Bijay Ranjan; Samantray, Jyotish Chandra

2002-12-01

The prevalence of intestinal parasitic infections was studied for a period of 5 years (April 1996-April 2001) among urban slum dwellers. All age groups were represented in the study. Parasitological examinations were performed on 939 faecal specimens collected on a household basis. The total prevalence of pathogenic parasites was 33.6 per cent. No significant age and sex differences in pathogenic parasites were observed. The prevalence of intestinal helminths and pathogenic protozoa was as follows: Hymenolepis nana (9.9 per cent), Ascaris lumbricoides (8.5 per cent), Giardia lamblia (8.4 per cent) and Entamoeba histolyticaldispar (3.7 per cent). Thirty-four E. histolytica/dispar positive samples were cultured and speciation was done using polymerase chain reaction (PCR). The predominant isolate was E. dispar compared to E. histolytica. The notable finding of the present study was high prevalence of Hymenolepis nana compared with other parasitic infections in slum dwellers.

Cardiomyopathy Syndrome of Atlantic Salmon (Salmo salar L.) Is Caused by a Double-Stranded RNA Virus of the Totiviridae Family▿

PubMed Central

Haugland, Øyvind; Mikalsen, Aase B.; Nilsen, Pål; Lindmo, Karine; Thu, Beate J.; Eliassen, Trygve M.; Roos, Norbert; Rode, Marit; Evensen, Øystein

2011-01-01

Cardiomyopathy syndrome (CMS) of farmed and wild Atlantic salmon (Salmo salar L.) is a disease of yet unknown etiology characterized by a necrotizing myocarditis involving the atrium and the spongious part of the heart ventricle. Here, we report the identification of a double-stranded RNA virus likely belonging to the family Totiviridae as the causative agent of the disease. The proposed name of the virus is piscine myocarditis virus (PMCV). On the basis of the RNA-dependent RNA polymerase (RdRp) sequence, PMCV grouped with Giardia lamblia virus and infectious myonecrosis virus of penaeid shrimp. The genome size of PMCV is 6,688 bp, with three open reading frames (ORFs). ORF1 likely encodes the major capsid protein, while ORF2 encodes the RdRp, possibly expressed as a fusion protein with the ORF1 product. ORF3 seems to be translated as a separate protein not described for any previous members of the family Totiviridae. Following experimental challenge with cell culture-grown virus, histopathological changes are observed in heart tissue by 6 weeks postchallenge (p.c.), with peak severity by 9 weeks p.c. Viral genome levels detected by real-time reverse transcription (RT)-PCR peak earlier at 6 to 7 weeks p.c. The virus genome is detected by in situ hybridization in degenerate cardiomyocytes from clinical cases of CMS. Virus genome levels in the hearts from clinical field cases correlate well with the severity of histopathological changes in heart tissue. The identification of the causative agent for CMS is important for improved disease surveillance and disease control and will serve as a basis for vaccine development against the disease. PMID:21411528

Health Status of Immigrant Children and Environmental Survey of Child Daycare Centers in Samut Sakhon Province, Thailand.

PubMed

Sagnuankiat, Surapol; Wanichsuwan, Molee; Bhunnachet, Ekaporn; Jungarat, Nahathai; Panraksa, Kanitha; Komalamisra, Chalit; Maipanich, Wanna; Yoonuan, Tippayarat; Pubampen, Somchit; Adisakwattana, Poom; Watthanakulpanich, Dorn

2016-02-01

Samut Sakhon is a Thai province popular among immigrants attracted to work in factories and the Thai food industry, especially people from Myanmar. Poor personal-hygiene behaviors, crowded accommodation and limited sanitation, result in health problems among immigrant workers. Various infectious diseases among this group are seen and managed by Samut Sakhon General Hospital. The impact of intestinal parasitic infections on public health is well known; they can spread from infected immigrant areas to uninfected areas via close contact and fecal-oral transmission from contaminated food and water. This study aimed to determine the prevalence of intestinal parasitic infections among 372 immigrant children at 8 child-daycare centers during their parents' work time, by physical examination, fecal examination, and examination of the environment around the centers. Physical examinations were generally unremarkable, except that head-lice and fingernail examinations were positive in two cases (0.8 %). The results showed intestinal parasitic infections to be highly prevalent, at 71.0 %. These infections comprised both helminths and protozoa: Trichuris trichiura (50.8 %), Enterobius vermicularis (25.2 %), Ascaris lumbricoides (15.3 %), hookworm (11.6 %), Giardia lamblia (10.2 %), Endolimax nana (3.5 %), Entamoeba coli (2.7 %), and Blastocystis hominis (0.5 %). The environmental survey found a small number of houseflies near the accommodation to be positive for helminthic eggs (0.2 %), including A. lumbricoides, E. vermicularis, hookworms, Taenia spp., and minute intestinal flukes. Regarding the high prevalence of intestinal parasitic infections among children, it has been conjectured whether they were infected, along with their parents, during their daily lives before or after settling in Thailand. Intestinal parasites among immigrant children may involve a significant epidemiological impact, since immigrant children can serve as carriers and transmitters of disease.

Vaccination of domestic animals with a novel oral vaccine prevents Giardia infections, alleviates signs of giardiasis and reduces transmission to humans

PubMed Central

Serradell, Marianela C; Saura, Alicia; Rupil, Lucia L; Gargantini, Pablo R; Faya, Marcela I; Furlan, Paulina J; Lujan, Hugo D

2016-01-01

Giardia lamblia is a human intestinal parasite and one of the most frequent enteric pathogen of companion animals. Clinical manifestations of giardiasis, such as diarrhoea, anorexia, weight loss and lethargy, have been associated with Giardia infections in both domestic and farm animals. A few anti-parasitic drugs are routinely used to treat giardiasis, but re-infections are common and drug-resistant strains have already been reported. Unfortunately, efficient vaccines against Giardia are not available. Giardia undergoes antigenic variation; through this mechanism, parasites can avoid the host’s immune defenses, causing chronic infections and/or re-infections. Antigenic variation is characterised by a continuous switch in the expression of members of a homologous family of genes encoding surface antigens. In a previous report, we indicated that in Giardia, the mechanism responsible for the exchange of variant-specific surface proteins (VSPs) involves the RNA interference (RNAi) pathway. From a repertoire of ~200 VSP genes, only one is expressed on the surface of single trophozoites; however, RNAi machinery disruption generates trophozoites that express the complete VSP repertoire. We also demonstrated that gerbils orally immunised with VSPs isolated from these altered parasites showed high levels of protection. Here we tested this vaccine in cats and dogs, and found that it is highly efficient in preventing new infections and reducing chronic giardiasis in domestic animals both in experimental and natural infections. Remarkably, immunisation of dogs in a highly endemic area strongly decreased the percentage of infected children in the community, suggesting that this vaccine would block the zoonotic transmission of the disease. PMID:29263857

Intestinal parasitic infections in children presenting with diarrhoea in outpatient and inpatient settings in an informal settlement of Nairobi, Kenya.

PubMed

Mbae, Cecilia Kathure; Nokes, David James; Mulinge, Erastus; Nyambura, Joyce; Waruru, Anthony; Kariuki, Samuel

2013-05-27

The distribution of and factors associated with intestinal parasitic infections are poorly defined in high risk vulnerable populations such as urban slums in tropical sub-Saharan Africa. In a cross sectional study, children aged 5 years and below who presented with diarrhoea were recruited from selected outpatient clinics in Mukuru informal settlement, and from Mbagathi District hospital, Nairobi, over a period of two years (2010-2011). Stool samples were examined for the presence of parasites using direct, formal-ether concentration method and the Modified Ziehl Neelsen staining technique. Overall, 541/2112 (25.6%) were positive for at least one intestinal parasite, with the common parasites being; Entamoeba histolytica, 225 (36.7%),Cryptosporidium spp. 187, (30.5%), Giardia lamblia, 98 (16%).The prevalence of intestinal parasites infection was higher among children from outpatient clinics 432/1577(27.4%) than among those admitted in hospital 109/535 (20.1%) p < 0.001. Infections with E. histolytica, and G. lamblia were higher among outpatients than inpatients (13.8% vs 1.3% p < 0.001 and 5.8% vs 1.3% p < 0.049) respectively, while infection with Cryptosporidium spp. was higher among inpatients than outpatients (15.3% vs 6.7%) respectively p < 0.001. Other parasites isolated among outpatients included Isospora belli, 19 (1.2%), Ascaris lumbricoides, 26 (1.6%), and Hymenolepis nana 12 (0.8%), with the remainder detected in less than ten samples each. HIV-infected participants were more likely to be infected with any parasite than uninfected participants, Adjusted Odds Ratio (AOR), 2.04, 95% CI, 1.55-2.67, p < 0.001), and with Cryptosporidium spp. (AOR, 2.96, 95% CI 2.07-4.21, p < 0.001).The inpatients were less likely to be infected with E. histolytica than outpatients (AOR, 0.11, 95% CI, 0.51-0.24, p < 0.001), but more likely for inpatients to be infected with Cryptosporidium spp. than outpatients (AOR, 1.91, 95% CI, 1.33-2.73, p < 0.001). Mixed parasitic infections were seen in 65 (12.0%) of the 541 infected stool samples. Intestinal parasitic infections are common in urban informal settlements' environment. Routine examinations of stool samples and treatment could benefit both the HIV infected and uninfected children in outpatient and inpatient settings.

Rapid imaging, detection and quantification of Giardia lamblia cysts using mobile-phone based fluorescent microscopy and machine learning.

PubMed

Koydemir, Hatice Ceylan; Gorocs, Zoltan; Tseng, Derek; Cortazar, Bingen; Feng, Steve; Chan, Raymond Yan Lok; Burbano, Jordi; McLeod, Euan; Ozcan, Aydogan

2015-03-07

Rapid and sensitive detection of waterborne pathogens in drinkable and recreational water sources is crucial for treating and preventing the spread of water related diseases, especially in resource-limited settings. Here we present a field-portable and cost-effective platform for detection and quantification of Giardia lamblia cysts, one of the most common waterborne parasites, which has a thick cell wall that makes it resistant to most water disinfection techniques including chlorination. The platform consists of a smartphone coupled with an opto-mechanical attachment weighing ~205 g, which utilizes a hand-held fluorescence microscope design aligned with the camera unit of the smartphone to image custom-designed disposable water sample cassettes. Each sample cassette is composed of absorbent pads and mechanical filter membranes; a membrane with 8 μm pore size is used as a porous spacing layer to prevent the backflow of particles to the upper membrane, while the top membrane with 5 μm pore size is used to capture the individual Giardia cysts that are fluorescently labeled. A fluorescence image of the filter surface (field-of-view: ~0.8 cm(2)) is captured and wirelessly transmitted via the mobile-phone to our servers for rapid processing using a machine learning algorithm that is trained on statistical features of Giardia cysts to automatically detect and count the cysts captured on the membrane. The results are then transmitted back to the mobile-phone in less than 2 minutes and are displayed through a smart application running on the phone. This mobile platform, along with our custom-developed sample preparation protocol, enables analysis of large volumes of water (e.g., 10-20 mL) for automated detection and enumeration of Giardia cysts in ~1 hour, including all the steps of sample preparation and analysis. We evaluated the performance of this approach using flow-cytometer-enumerated Giardia-contaminated water samples, demonstrating an average cyst capture efficiency of ~79% on our filter membrane along with a machine learning based cyst counting sensitivity of ~84%, yielding a limit-of-detection of ~12 cysts per 10 mL. Providing rapid detection and quantification of microorganisms, this field-portable imaging and sensing platform running on a mobile-phone could be useful for water quality monitoring in field and resource-limited settings.

Community Involvement Components in Culturally-Oriented Teacher Preparation.

ERIC Educational Resources Information Center

Mahan, James M.

1982-01-01

Describes community involvement components in culturally oriented teacher education program, i.e., preservice and inservice community agency assignments, oncampus cultural preparation. Reveals that cultural immersion student teacher programs are attractive and professionally advantageous. (AH)

Vocabulary Acquisition through Cloze Exercises, Sentence-Writing and Composition-Writing: Extending the Evaluation Component of the Involvement Load Hypothesis

ERIC Educational Resources Information Center

Zou, Di

2017-01-01

This research inspects the allocation of involvement load to the evaluation component of the involvement load hypothesis, examining how three typical approaches to evaluation (cloze-exercises, sentence-writing, and composition-writing) promote word learning. The results of this research were partially consistent with the predictions of the…

Metabarcoding analysis of eukaryotic microbiota in the gut of HIV-infected patients.

PubMed

Hamad, Ibrahim; Abou Abdallah, Rita; Ravaux, Isabelle; Mokhtari, Saadia; Tissot-Dupont, Hervé; Michelle, Caroline; Stein, Andreas; Lagier, Jean-Christophe; Raoult, Didier; Bittar, Fadi

2018-01-01

Research on the relationship between changes in the gut microbiota and human disease, including AIDS, is a growing field. However, studies on the eukaryotic component of the intestinal microbiota have just begun and have not yet been conducted in HIV-infected patients. Moreover, eukaryotic community profiling is influenced by the use of different methodologies at each step of culture-independent techniques. Herein, initially, four DNA extraction protocols were compared to test the efficiency of each method in recovering eukaryotic DNA from fecal samples. Our results revealed that recovering eukaryotic components from fecal samples differs significantly among DNA extraction methods. Subsequently, the composition of the intestinal eukaryotic microbiota was evaluated in HIV-infected patients and healthy volunteers through clone sequencing, high-throughput sequencing of nuclear ribosomal internal transcribed spacers 1 (ITS1) and 2 (ITS2) amplicons and real-time PCRs. Our results revealed that not only richness (Chao-1 index) and alpha diversity (Shannon diversity) differ between HIV-infected patients and healthy volunteers, depending on the molecular strategy used, but also the global eukaryotic community composition, with little overlapping taxa found between techniques. Moreover, our results based on cloning libraries and ITS1/ITS2 metabarcoding sequencing showed significant differences in fungal composition between HIV-infected patients and healthy volunteers, but without distinct clusters separating the two groups. Malassezia restricta was significantly more prevalent in fecal samples of HIV-infected patients, according to cloning libraries, whereas operational taxonomic units (OTUs) belonging to Candida albicans and Candida tropicalis were significantly more abundant in fecal samples of HIV-infected patients compared to healthy subjects in both ITS subregions. Finally, real-time PCR showed the presence of Microsporidia, Giardia lamblia, Blastocystis and Hymenolepis diminuta in different proportions in fecal samples from HIV patients as compared to healthy individuals. Our work revealed that the use of different sequencing approaches can impact the perceived eukaryotic diversity results of the human gut. We also provide a more comprehensive view of the eukaryotic community in the gut of HIV-infected patients through the complementarity of the different molecular techniques used. Combining these various methodologies may provide a gold standard for a more complete characterization of the eukaryotic microbiome in future studies.

Separate cortical networks involved in music perception: preliminary functional MRI evidence for modularity of music processing.

PubMed

Schmithorst, Vincent J

2005-04-01

Music perception is a quite complex cognitive task, involving the perception and integration of various elements including melody, harmony, pitch, rhythm, and timbre. A preliminary functional MRI investigation of music perception was performed, using a simplified passive listening task. Group independent component analysis (ICA) was used to separate out various components involved in music processing, as the hemodynamic responses are not known a priori. Various components consistent with auditory processing, expressive language, syntactic processing, and visual association were found. The results are discussed in light of various hypotheses regarding modularity of music processing and its overlap with language processing. The results suggest that, while some networks overlap with ones used for language processing, music processing may involve its own domain-specific processing subsystems.

Communicative Interaction Processes Involving Non-Vocal Physically Handicapped Children.

ERIC Educational Resources Information Center

Harris, Deberah

1982-01-01

Communication prostheses are critical components of the nonvocal child's communication process, but are only one component. This article focuses on the steps involved in communicative interaction processes and the potential barriers to the development of effective interaction and analysis of nonvocal communicative interactions. A discussion of the…

49 CFR 579.23 - Reporting requirements for manufacturers of 5,000 or more motorcycles annually.

Code of Federal Regulations, 2012 CFR

2012-10-01

... claims, consumer complaints, warranty claims, and field reports which involve the systems and components..., consumer complaints, warranty claims, or field reports, respectively, that involves the systems or components or fire indicated by the code. If an underlying property damage claim, consumer complaint...

49 CFR 579.23 - Reporting requirements for manufacturers of 5,000 or more motorcycles annually.

Code of Federal Regulations, 2014 CFR

2014-10-01

... claims, consumer complaints, warranty claims, and field reports which involve the systems and components..., consumer complaints, warranty claims, or field reports, respectively, that involves the systems or components or fire indicated by the code. If an underlying property damage claim, consumer complaint...

49 CFR 579.23 - Reporting requirements for manufacturers of 5,000 or more motorcycles annually.

Code of Federal Regulations, 2013 CFR

2013-10-01

... claims, consumer complaints, warranty claims, and field reports which involve the systems and components..., consumer complaints, warranty claims, or field reports, respectively, that involves the systems or components or fire indicated by the code. If an underlying property damage claim, consumer complaint...

Prevalence of intestinal parasitic infections in certified food-handlers working in food establishments in the City of Nairobi, Kenya.

PubMed

Kamau, Paul; Aloo-Obudho, Penina; Kabiru, Ephantus; Ombacho, Kepha; Langat, Bernard; Mucheru, Obadiah; Ireri, Laban

2012-03-01

Most intestinal parasites are cosmopolitan with the highest prevalence in the tropics and subtopics. Rural-to-urban migration rapidly increases the number of food eating places in towns and their environs. Some of these eating estabishments have poor sanitation and are overcrowded, facilitating disease transmission, especially through food-handling. Our investigations in Nairobi, therefore, were set to determine the presence of intestinal parasites in food-handlers with valid medical certificates. Direct and concentrated stool processing techniques were used. Chisquare test and ANOVA were used for data analysis. The parasites Ascaris lumbricoides, Entamoeba histolytica and Giardia lamblia were observed in certified food-handlers. Significant difference was found in parasite frequency by eating classes and gender (χ(2) = 9.49, P = 0.73), (F = 1.495, P = 0.297), but not in parasite occurrence between age brackets (χ(2) = 6.99, P = 0.039). The six-month medical certificate validity period may contribute significantly to the presence of intestinal parasites in certified food-handlers.

The endoparasites of sheep and goats, and shepherd in North Sinai Governorate, Egypt.

PubMed

Mazyad, Said A M; el-Nemr, Hossam I

2002-04-01

Examination of sheep and goats in four areas in North Sinai revealed an overall infection of 12.70% with Fasciola species, 11.8% with Paramphistomum cerve, 12.80% with Moniezia expansa, 47.11% with Trichostrongylus colubriformis, 4.59% Trichuris ovis and 44.85% Coccidia. The highly infected sheep and goats were diagnosed in El Hassanah center (90.49%), followed by Al Arish city (87.31%), then Rafah city (74.39%), and lastly Bir Al Abd (54.71%). The elevation of the overall percent of infection in the four areas was due to Coccidia infection. This parasite was a concomitant infection in nearly all animals. On the other hand, examination of fifteen of the shepherds revealed Ascaris lumbricoides in four, T. colubriformis in three, Fasciala in one, Giardia lamblia in ten and Coccidia in three. Double and rarely, triple infection was seen. The correlation between parasitic infections in sheep and goats, and their shepherd was discussed.

Post-travel screening of asymptomatic long-term travelers to the tropics for intestinal parasites using molecular diagnostics.

PubMed

Soonawala, Darius; van Lieshout, Lisette; den Boer, Marion A M; Claas, Eric C J; Verweij, Jaco J; Godkewitsch, André; Ratering, Marchel; Visser, Leo G

2014-05-01

The incidence of asymptomatic travel-related parasitic infection is uncertain. Previous studies did not distinguish new incident infections, from past infections. Regardless of symptoms, we performed multiplex real-time polymerase chain reaction on pre- and post-travel stool samples of Dutch long-term travelers to the (sub)tropics. Serological screening for Schistosoma spp. was only performed in travelers to sub-Saharan Africa. In total, 679 travelers were included in the study. The follow-up rate was 82% (556 of 679). Participants' median travel duration was 12 weeks. There was one incident infection with Strongyloides stercoralis; there were none with Entamoeba histolytica, 4 with Cryptosporidium spp. (1%), and 22 with Giardia lamblia (4%). Nine of 146 travelers (6%) seroconverted for Schistosoma spp. Routine screening of stool samples for parasitic infection is not indicated for asymptomatic people, who travel to the (sub)tropics for up to 3 months. Screening for Schistosoma spp. should be offered to travelers with fresh-water contact in endemic regions.

Post-Travel Screening of Asymptomatic Long-Term Travelers to the Tropics for Intestinal Parasites Using Molecular Diagnostics

PubMed Central

Soonawala, Darius; van Lieshout, Lisette; den Boer, Marion A. M.; Claas, Eric C. J.; Verweij, Jaco J.; Godkewitsch, André; Ratering, Marchel; Visser, Leo G.

2014-01-01

The incidence of asymptomatic travel-related parasitic infection is uncertain. Previous studies did not distinguish new incident infections, from past infections. Regardless of symptoms, we performed multiplex real-time polymerase chain reaction on pre- and post-travel stool samples of Dutch long-term travelers to the (sub)tropics. Serological screening for Schistosoma spp. was only performed in travelers to sub-Saharan Africa. In total, 679 travelers were included in the study. The follow-up rate was 82% (556 of 679). Participants' median travel duration was 12 weeks. There was one incident infection with Strongyloides stercoralis; there were none with Entamoeba histolytica, 4 with Cryptosporidium spp. (1%), and 22 with Giardia lamblia (4%). Nine of 146 travelers (6%) seroconverted for Schistosoma spp. Routine screening of stool samples for parasitic infection is not indicated for asymptomatic people, who travel to the (sub)tropics for up to 3 months. Screening for Schistosoma spp. should be offered to travelers with fresh-water contact in endemic regions. PMID:24615130

Microbial detection in microfluidic devices through dual staining of quantum dots-labeled immunoassay and RNA hybridization.

PubMed

Zhang, Qing; Zhu, Liang; Feng, Hanhua; Ang, Simon; Chau, Fook Siong; Liu, Wen-Tso

2006-01-18

This paper reported the development of a microfludic device for the rapid detection of viable and nonviable microbial cells through dual labeling by fluorescent in situ hybridization (FISH) and quantum dots (QDs)-labeled immunofluorescent assay (IFA). The coin sized device consists of a microchannel and filtering pillars (gap=1-2 microm) and was demonstrated to effectively trap and concentrate microbial cells (i.e. Giardia lamblia). After sample injection, FISH probe solution and QDs-labeled antibody solution were sequentially pumped into the device to accelerate the fluorescent labeling reactions at optimized flow rates (i.e. 1 and 20 microL/min, respectively). After 2 min washing for each assay, the whole process could be finished within 30 min, with minimum consumption of labeling reagents and superior fluorescent signal intensity. The choice of QDs 525 for IFA resulted in bright and stable fluorescent signal, with minimum interference with the Cy3 signal from FISH detection.

Breast-feeding protects infantile diarrhea caused by intestinal protozoan infections.

PubMed

Abdel-Hafeez, Ekhlas Hamed; Belal, Usama Salah; Abdellatif, Manal Zaki Mohamed; Naoi, Koji; Norose, Kazumi

2013-10-01

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-α were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-α were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-α and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.

Cryptosporidium and Giardia in Humans, Domestic Animals, and Village Water Sources in Rural India

PubMed Central

Daniels, Miles E.; Shrivastava, Arpit; Smith, Woutrina A.; Sahu, Priyadarshi; Odagiri, Mitsunori; Misra, Pravas R.; Panigrahi, Pinaki; Suar, Mrutyunjay; Clasen, Thomas; Jenkins, Marion W.

2015-01-01

Cryptosporidium parvum and Giardia lamblia are zoonotic enteric protozoa of significant health concern where sanitation, hygiene, and water supplies are inadequate. We examined 85 stool samples from diarrhea patients, 111 pooled fecal samples by species across seven domestic animal types, and water from tube wells (N = 207) and ponds (N = 94) across 60 villages in coastal Odisha, India, for Cryptosporidium oocysts and Giardia cysts to measure occurrence, concentration/shedding, and environmental loading rates. Oocysts/cysts were detected in 12% of diarrhea patients. Detection ranged from 0% to 35% for Cryptosporidium and 0% to 67% for Giardia across animal hosts. Animal loading estimates indicate the greatest contributors of environmental oocysts/cysts in the study region are cattle. Ponds were contaminated with both protozoa (oocysts: 37%, cysts: 74%), as were tube wells (oocysts: 10%, cysts: 14%). Future research should address the public health concern highlighted from these findings and investigate the role of domestic animals in diarrheal disease transmission in this and similar settings. PMID:26123963

Genotyping of Giardia isolates in Scotland: a descriptive epidemiological study.

PubMed

Alexander, C; Jones, B; Inverarity, D; Pollock, K G J

2014-08-01

Giardiasis, caused by the intestinal protozoan parasite Giardia intestinalis (synonyms: G. lamblia, G. duodenalis), is one of the most frequent parasites to infect the Scottish population. Transmission of the infective cysts in faecal matter is commonly via food and/or water. Giardia is subdivided into assemblages, where clinical and epidemiological differences have been described between assemblages A and B. This snapshot descriptive epidemiological study examines 30 positive cases of Giardia of which 72% (n = 21) were shown to be assemblage A, 14% (n = 4) assemblage B and 10% (n = 3) mixed assemblages (A and B). There was a 2:3 female:male ratio of affected individuals with foreign travel recorded in 22 of these cases. The commonest symptom was diarrhoea which was reported in 80% of cases followed by tiredness. Five cases required hospitalization emphasizing the importance of gaining a greater understanding of how Giardia assemblages influence clinical outcomes to assist in formulating guidelines to manage potential Giardia outbreaks.

Potential impacts of climate change on infectious diseases in the Arctic.

PubMed

Parkinson, Alan J; Butler, Jay C

2005-12-01

Climate change could cause changes in the incidence of infectious diseases in Arctic regions. Higher ambient temperatures in the Arctic may result in an increase in some temperature sensitive foodborne diseases such as gastroenteritis, paralytic shellfish poisoning and botulism. An increase in mean temperature may also influence the incidence of infectious diseases of animals that are spread to humans (zoonoses) by changing the population and range of animal hosts and insect vectors. An increase in flooding events may result in outbreaks of waterborne infection, such as Giardia lamblia or Cryptospordium parvum. A change in rodent and fox populations may result in an increase in rabies or echinococcosis. Temperature and humidity influence the distribution and density of many arthropod vectors which in turn may influence the incidence and northern range of vectorborne diseases such as West Nile virus. Recommendations include: the strenghtening of public health systems, disease surveillance coordinated with climate monitoring, and research into the detection, prevention, control and treatment of temperature-sensitive infectious diseases.

Developmental changes in the adhesive disk during Giardia differentiation.

PubMed

Palm, Daniel; Weiland, Malin; McArthur, Andrew G; Winiecka-Krusnell, Jadwiga; Cipriano, Michael J; Birkeland, Shanda R; Pacocha, Sarah E; Davids, Barbara; Gillin, Frances; Linder, Ewert; Svärd, Staffan

2005-06-01

Giardia lamblia is a protozoan parasite infecting the upper mammalian small intestine. Infection relies upon the ability of the parasite to attach to the intestine via a unique cytoskeletal organelle, the ventral disk. We determined the composition and structure of the disk throughout the life cycle of the parasite and identified a new disk protein, SALP-1. SALP-1 is an immunodominant protein related to striated fiber-assemblin (SFA). The disk is disassembled during encystation and stored as four fragments in the immobile cyst. Serial Analysis of Gene Expression (SAGE) showed that the mRNA levels of the disk proteins decreased in encystation but two-dimensional protein gels showed that the protein levels were more constant. The parasite emerges without a functional disk but the four disk fragments are quickly reassembled into two new disks on the dividing, early excysting form. Thus, disk proteins are stored within the cyst, ready to be used in the rapid steps of excystation.

Opportunistic Parasites among Immunosuppressed Children in Minia District, Egypt

PubMed Central

Ahmad, Azza K.; Ali, Basma A.; Moslam, Fadia A.

2012-01-01

A total of 450 stool samples were collected from inpatient and outpatient clinics of Pediatric Department, Minia University Hospital, Minia District, Egypt. Two groups of patients were studied, including 200 immunosuppressed and 250 immunocompetent children. Stool samples were subjected to wet saline and iodine mounts. A concentration technique (formol-ether sedimentation method) was carried out for stool samples diagnosed negative by wet saline and iodine mounts. Samples were stained by 2 different methods; acid fast stain (modified Ziehl-Neelsen stain) and Giemsa stain. Total 188 cases (94%) were diagnosed positive for parasitic infections among immunosuppressed children, whereas 150 cases (60%) were positive in immunocompetent children (P<0.0001). The most common protozoan infection in immunosuppressed group was Cryptosporidium parvum (60.2%), followed by Blastocystis hominis (12.1%), Isospora belli (9.7%), and Cyclospora caytenensis (7.8%). On the other hand, Entamoeba histolytica (24.6%) and Giardia lamblia (17.6%) were more common than other protozoans in immunocompetent children. PMID:22451735

[Whipple's disease associated with opportunistic infections].

PubMed

Meier-Willersen, H J; Maiwald, M; von Herbay, A

1993-06-11

A 36-year-old man, with a history of recurrent respiratory infection, dermatomycosis, arthralgia and abnormal stools for 12 years, developed a febrile illness (up to 40 degrees C). A Serratia marcescens septicaemia responded to antibiotics. Four months later cervical and abdominal lymph-adenopathies were noticed. Cervical lymph node biopsy revealed lymphadenitis with epithelioid cell nests. Duodenoscopy with biopsy demonstrated Whipple's disease associated with lambliasis. Electron-microscopy showed rod-shaped bacteria typical of Whipple's disease, and Giardia lamblia. Using the polymerase chain reaction, Whipple-specific DNA fragments of 284 base pairs from the genome of the Whipple bacterium (Tropheryma whippelii) were demonstrated. Antibiotic treatment with Ampicillin (2 g three times daily) and ceftriaxone (2 g once daily) i.v. for 21 days, followed by oral ofloxacin (200 mg daily) and co-trimoxazole (three times daily 800 mg sulfamethoxazole and 160 mg trimethoprim), brought about remission of Whipple's disease. Long-term antibiotic treatment was continued with co-trimoxazole. Lambliasis recurred after 3 and 5 months, despite treatment with metronidazole, 250 mg three times daily for 7 days.

Flash lamp-excited time-resolved fluorescence microscope suppresses autofluorescence in water concentrates to deliver an 11-fold increase in signal-to-noise ratio.

PubMed

Connally, Russell; Veal, Duncan; Piper, James

2004-01-01

The ubiquity of naturally fluorescing components (autofluorophores) encountered in most biological samples hinders the detection and identification of labeled targets through fluorescence-based techniques. Time-resolved fluorescence (TRF) is a technique by which the effects of autofluorescence are reduced by using specific fluorescent labels with long fluorescence lifetimes (compared with autofluorophores) in conjunction with time-gated detection. A time-resolved fluorescence microscope (TRFM) is described that is based on a standard epifluorescence microscope modified by the addition of a pulsed excitation source and an image-intensified time-gateable CCD camera. The choice of pulsed excitation source for TRFM has a large impact on the price and performance of the instrument. A flash lamp with rapid discharge characteristics was selected for our instrument because of the high spectral energy in the UV region and short pulse length. However, the flash output decayed with an approximate lifetime of 18 micros and the TRFM required a long-lived lanthanide chelate label to ensure that probe fluorescence was visible after decay of the flash plasma. We synthesized a recently reported fluorescent chelate (BHHCT) and conjugated it to a monoclonal antibody directed against the waterborne parasite Giardia lamblia. For a 600-nm bandpass filter set and a gate delay of 60 micros, the TRFM provided an 11.3-fold improvement in the signal-to-noise ratio (S/N) of labeled Giardia over background. A smaller gain in an SNR of 9.69-fold was achieved with a 420-nm longpass filter set; however, the final contrast ratio between labeled cyst and background was higher (11.3 versus 8.5). Despite the decay characteristics of the light pulse, flash lamps have many practical advantages compared with optical chopper wheels and modulated lasers for applications in TRFM.

Synthesis of zwitterionic salts of pyridinium-Meldrum acid and barbiturate through unique four-component reactions.

PubMed

Wang, Qi-Fang; Hui, Li; Hou, Hong; Yan, Chao-Guo

2010-03-08

An efficient synthetic procedure for the preparation of the unusual charge-separated pyridinium-Meldrum acid and N,N-dimethylbarbiturate acid zwitterionic salts was developed though a unique one-pot four-component reaction involving pyridine, aromatic aldehyde, Meldrum acid or N,N-dimethylbarbituric acid, and p-nitrobenzyl bromide in acetonitrile. By varying combinations of four components involving nitrogen-containing heterocycles, we conveniently established reactive alpha-halomethylene compounds, aldehydes and beta-dicarbonyl compounds a library of zwitterionic salts.

Implementation and Qualifications Lessons Learned for Space Flight Photonic Components

NASA Technical Reports Server (NTRS)

Ott, Melanie N.

2010-01-01

This slide presentation reviews the process for implementation and qualification of space flight photonic components. It discusses the causes for most common anomalies for the space flight components, design compatibility, a specific failure analysis of optical fiber that occurred in a cable in 1999-2000, and another ExPCA connector anomaly involving pins that broke off. It reviews issues around material selection, quality processes and documentation, and current projects that the Photonics group is involved in. The importance of good documentation is stressed.

Factors associated with successful transition among children with disabilities in eight European countries

PubMed Central

2017-01-01

Introduction This research paper aims to assess factors reported by parents associated with the successful transition of children with complex additional support requirements that have undergone a transition between school environments from 8 European Union member states. Methods Quantitative data were collected from 306 parents within education systems from 8 EU member states (Bulgaria, Cyprus, Greece, Ireland, the Netherlands, Romania, Spain and the UK). The data were derived from an online questionnaire and consisted of 41 questions. Information was collected on: parental involvement in their child’s transition, child involvement in transition, child autonomy, school ethos, professionals’ involvement in transition and integrated working, such as, joint assessment, cooperation and coordination between agencies. Survey questions that were designed on a Likert-scale were included in the Principal Components Analysis (PCA), additional survey questions, along with the results from the PCA, were used to build a logistic regression model. Results Four principal components were identified accounting for 48.86% of the variability in the data. Principal component 1 (PC1), ‘child inclusive ethos,’ contains 16.17% of the variation. Principal component 2 (PC2), which represents child autonomy and involvement, is responsible for 8.52% of the total variation. Principal component 3 (PC3) contains questions relating to parental involvement and contributed to 12.26% of the overall variation. Principal component 4 (PC4), which involves transition planning and coordination, contributed to 11.91% of the overall variation. Finally, the principal components were included in a logistic regression to evaluate the relationship between inclusion and a successful transition, as well as whether other factors that may have influenced transition. All four principal components were significantly associated with a successful transition, with PC1 being having the most effect (OR: 4.04, CI: 2.43–7.18, p<0.0001). Discussion To support a child with complex additional support requirements through transition from special school to mainstream, governments and professionals need to ensure children with additional support requirements and their parents are at the centre of all decisions that affect them. It is important that professionals recognise the educational, psychological, social and cultural contexts of a child with additional support requirements and their families which will provide a holistic approach and remove barriers for learning. PMID:28636649

Factors associated with successful transition among children with disabilities in eight European countries.

PubMed

Ravenscroft, John; Wazny, Kerri; Davis, John M

2017-01-01

This research paper aims to assess factors reported by parents associated with the successful transition of children with complex additional support requirements that have undergone a transition between school environments from 8 European Union member states. Quantitative data were collected from 306 parents within education systems from 8 EU member states (Bulgaria, Cyprus, Greece, Ireland, the Netherlands, Romania, Spain and the UK). The data were derived from an online questionnaire and consisted of 41 questions. Information was collected on: parental involvement in their child's transition, child involvement in transition, child autonomy, school ethos, professionals' involvement in transition and integrated working, such as, joint assessment, cooperation and coordination between agencies. Survey questions that were designed on a Likert-scale were included in the Principal Components Analysis (PCA), additional survey questions, along with the results from the PCA, were used to build a logistic regression model. Four principal components were identified accounting for 48.86% of the variability in the data. Principal component 1 (PC1), 'child inclusive ethos,' contains 16.17% of the variation. Principal component 2 (PC2), which represents child autonomy and involvement, is responsible for 8.52% of the total variation. Principal component 3 (PC3) contains questions relating to parental involvement and contributed to 12.26% of the overall variation. Principal component 4 (PC4), which involves transition planning and coordination, contributed to 11.91% of the overall variation. Finally, the principal components were included in a logistic regression to evaluate the relationship between inclusion and a successful transition, as well as whether other factors that may have influenced transition. All four principal components were significantly associated with a successful transition, with PC1 being having the most effect (OR: 4.04, CI: 2.43-7.18, p<0.0001). To support a child with complex additional support requirements through transition from special school to mainstream, governments and professionals need to ensure children with additional support requirements and their parents are at the centre of all decisions that affect them. It is important that professionals recognise the educational, psychological, social and cultural contexts of a child with additional support requirements and their families which will provide a holistic approach and remove barriers for learning.

The development of Drink Less: an alcohol reduction smartphone app for excessive drinkers.

PubMed

Garnett, Claire; Crane, David; West, Robert; Brown, Jamie; Michie, Susan

2018-05-04

Excessive alcohol consumption poses a serious problem for public health. Digital behavior change interventions have the potential to help users reduce their drinking. In accordance with Open Science principles, this paper describes the development of a smartphone app to help individuals who drink excessively to reduce their alcohol consumption. Following the UK Medical Research Council's guidance and the Multiphase Optimization Strategy, development consisted of two phases: (i) selection of intervention components and (ii) design and development work to implement the chosen components into modules to be evaluated further for inclusion in the app. Phase 1 involved a scoping literature review, expert consensus study and content analysis of existing alcohol apps. Findings were integrated within a broad model of behavior change (Capability, Opportunity, Motivation-Behavior). Phase 2 involved a highly iterative process and used the "Person-Based" approach to promote engagement. From Phase 1, five intervention components were selected: (i) Normative Feedback, (ii) Cognitive Bias Re-training, (iii) Self-monitoring and Feedback, (iv) Action Planning, and (v) Identity Change. Phase 2 indicated that each of these components presented different challenges for implementation as app modules; all required multiple iterations and design changes to arrive at versions that would be suitable for inclusion in a subsequent evaluation study. The development of the Drink Less app involved a thorough process of component identification with a scoping literature review, expert consensus, and review of other apps. Translation of the components into app modules required a highly iterative process involving user testing and design modification.

Stakeholder involvement in water management: necessity or luxury?

PubMed

Morrison, K

2003-01-01

Stakeholder involvement in water management is widely recognized as an important component of the design and implementation of sustainable water management initiatives. Despite this, there remains a deep-rooted resistance to the widespread implementation of programs to prioritize such involvement (as witnessed by, for example, the low priority given to the public involvement element of the European Union Water Framework Directive). This paper addresses the issue of stakeholder involvement by first confronting the fact that it is not a water issue, per se. Such diverse fields as economics, agriculture, public health, pollution prevention, business and education have also identified stakeholder involvement as a difficult but necessary component of successful action in their fields. For the water sector, the issue of stakeholder involvement as either a necessity for sustainable water management, or a luxury to be used to complement traditional approaches, is discussed.

Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

ERIC Educational Resources Information Center

Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

2009-01-01

The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

Integrating ARCS Motivational Theory into the Component Display Theory of Instructional Design.

ERIC Educational Resources Information Center

Marovitz, Mitchell E.; Buckley, Jeanne

A two-stage study was conducted to determine the effects of motivational components in the learning experience. The first stage involved administration of a survey instrument to 150 teachers in the New York City area to obtain information on the means by which teachers incorporate motivation into their instruction. The second stage involved the…

Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors.

PubMed

Burger, Joanna; Gochfeld, Michael; Bunn, Amoret; Downs, Janelle; Jeitner, Christian; Pittfield, Taryn; Salisbury, Jennifer

2016-01-01

Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define and describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.

Psychological comorbidity increases the risk for postinfectious IBS partly by enhanced susceptibility to develop infectious gastroenteritis.

PubMed

Wouters, Mira M; Van Wanrooy, Sander; Nguyen, Anh; Dooley, James; Aguilera-Lizarraga, Javier; Van Brabant, Winde; Garcia-Perez, Josselyn E; Van Oudenhove, Lukas; Van Ranst, Marc; Verhaegen, Jan; Liston, Adrian; Boeckxstaens, Guy

2016-08-01

Psychological factors increase the risk to develop postinfectious IBS (PI-IBS), but the mechanisms involved are unclear. As stress affects the immune system, we investigated the potential interaction between psychological factors, the immune response against infectious gastroenteritis (IGE) and the development of IGE and PI-IBS in a large cohort exposed to contaminated drinking water. 18 620 people exposed to contaminated drinking water (norovirus, Giardia lamblia, Campylobacter jejuni) were invited to participate in a prospective controlled cohort study. They were asked to complete questionnaires assessing demographic, psychological and clinical data during the outbreak and 1 year later. At both time points, in-depth immune function (peripheral blood and rectal biopsies) was studied in a subgroup of subjects. 1379 subjects completed the questionnaires during the outbreak, of which 271 developed IGE. Risk factors for IGE included younger age, pre-existing dyspepsia-like symptoms, anxiety and drinking contaminated tap water. Anxiety scores before the outbreak inversely correlated with interleukin-2-expressing CD4+ T cells (r=0.6, p=0.01, n=23). At follow-up, 34 of 172 (20%) IGE subjects developed IBS compared with 24/366 exposed participants (7%, p<0.0001, χ(2) test). A Th2 cytokine phenotype at time of infection was associated with increased risk for PI-IBS 1 year later. Except for increased B cell numbers, no evidence for systemic or rectal mucosal immune activation in PI-IBS was demonstrated at follow-up. Our study shows that the increased risk of patients with psychological comorbidity to develop PI-IBS may partly result from an increased susceptibility to develop IGE, possibly resulting from a Th2-immune bias. (ClinicalTrials.gov NCT01497847). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Breadth and depth involvement: Understanding Internet gambling involvement and its relationship to gambling problems.

PubMed

LaPlante, Debi A; Nelson, Sarah E; Gray, Heather M

2014-06-01

The "involvement effect" refers to the finding that controlling for gambling involvement often reduces or eliminates frequently observed game-specific associations with problem gambling. In other words, broader patterns of gambling behavior, particularly the number of types of games played over a defined period, contribute more to problem gambling than playing specific games (e.g., lottery, casino, Internet gambling). This study extends this burgeoning area of inquiry in three primary ways. First, it tests independently and simultaneously the predictive power of two gambling patterns: breadth involvement (i.e., the number of games an individual plays) and depth involvement (i.e., the number of days an individual plays). Second, it includes the first involvement analyses of actual betting activity records that are associated with clinical screening information. Third, it evaluates and compares the linearity of breadth and depth effects. We conducted analyses of the actual gambling activity of 1,440 subscribers to the bwin.party gambling service who completed an online gambling disorder screen. In all, 11 of the 16 games we examined had a significant univariate association with a positive screen for gambling disorder. However, after controlling for breadth involvement, only Live Action Internet sports betting retained a significant relationship with potential gambling-related problems. Depth involvement, though significantly related to potential problems, did not impact game-based gambling disorder associations as much as breadth involvement. Finally, breadth effects appeared steeply linear, with a slight quadratic component manifesting beyond four games played, but depth effects appeared to have a strong linear component and a slight cubic component.

Relevance of the two-component sensor protein CiaH to acid and oxidative stress responses in Streptococcus pyogenes.

PubMed

Tatsuno, Ichiro; Isaka, Masanori; Okada, Ryo; Zhang, Yan; Hasegawa, Tadao

2014-03-28

The production of virulence proteins depends on environmental factors, and two-component regulatory systems are involved in sensing these factors. We previously established knockout strains in all suspected two-component regulatory sensor proteins of the emm1 clinical strain of S. pyogenes and examined their relevance to acid stimuli in a natural atmosphere. In the present study, their relevance to acid stimuli was re-examined in an atmosphere containing 5% CO2. The spy1236 (which is identical to ciaHpy) sensor knockout strain showed significant growth reduction compared with the parental strain in broth at pH 6.0, suggesting that the Spy1236 (CiaHpy) two-component sensor protein is involved in acid response of S. pyogenes. CiaH is also conserved in Streptococcus pneumoniae, and it has been reported that deletion of the gene for its cognate response regulator (ciaRpn) made the pneumococcal strains more sensitive to oxidative stress. In this report, we show that the spy1236 knockout mutant of S. pyogenes is more sensitive to oxidative stress than the parental strain. These results suggest that the two-component sensor protein CiaH is involved in stress responses in S. pyogenes.

Independent component model for cognitive functions of multiple subjects using [15O]H2O PET images.

PubMed

Park, Hae-Jeong; Kim, Jae-Jin; Youn, Tak; Lee, Dong Soo; Lee, Myung Chul; Kwon, Jun Soo

2003-04-01

An independent component model of multiple subjects' positron emission tomography (PET) images is proposed to explore the overall functional components involved in a task and to explain subject specific variations of metabolic activities under altered experimental conditions utilizing the Independent component analysis (ICA) concept. As PET images represent time-compressed activities of several cognitive components, we derived a mathematical model to decompose functional components from cross-sectional images based on two fundamental hypotheses: (1) all subjects share basic functional components that are common to subjects and spatially independent of each other in relation to the given experimental task, and (2) all subjects share common functional components throughout tasks which are also spatially independent. The variations of hemodynamic activities according to subjects or tasks can be explained by the variations in the usage weight of the functional components. We investigated the plausibility of the model using serial cognitive experiments of simple object perception, object recognition, two-back working memory, and divided attention of a syntactic process. We found that the independent component model satisfactorily explained the functional components involved in the task and discuss here the application of ICA in multiple subjects' PET images to explore the functional association of brain activations. Copyright 2003 Wiley-Liss, Inc.

77 FR 36419 - Feasibility of Enumerating “Specially Designed” Components

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-19

... feasibility of positively identifying ``specially designed'' ``components'' on the Commerce Control List (CCL... exhaustive lists of the ``specially designed'' ``components'' referred to in certain Export Control... project involving minimizing the use of the term ``specially designed'' on the current Commerce Control...

ESEA Title I Migrant. Final Technical Report.

ERIC Educational Resources Information Center

Austin Independent School District, TX. Office of Research and Evaluation.

The 1981-82 Austin (Texas) Independent School District Title I Migrant Program consisted of seven components: three instructional components--prekindergarten, communication skills, and summer school; and four support components--health services, parental involvement, migrant student record transfer system (MSRTS), and evaluation. The major…

[Hypovitaminosis D and metabolic syndrome].

PubMed

Miñambres, Inka; de Leiva, Alberto; Pérez, Antonio

2014-12-23

Metabolic syndrome and hypovitaminosis D are 2 diseases with high prevalence that share several risk factors, while epidemiological evidence shows they are associated. Although the mechanisms involved in this association are not well established, hypovitaminosis D is associated with insulin resistance, decreased insulin secretion and activation of the renin-angiotensin system, mechanisms involved in the pathophysiology of metabolic syndrome. However, the apparent ineffectiveness of vitamin D supplementation on metabolic syndrome components, as well as the limited information about the effect of improving metabolic syndrome components on vitamin D concentrations, does not clarify the direction and the mechanisms involved in the causal relationship between these 2 pathologies. Overall, because of the high prevalence and the epidemiological association between both diseases, hypovitaminosis D could be considered a component of the metabolic syndrome. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Functional remediation components: A conceptual method of evaluating the effects of remediation on risks to ecological receptors

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

Burger, Joanna; Gochfeld, Michael; Bunn, Amoret

2016-08-30

Governmental agencies, regulators, health professionals, tribal leaders, and the public are faced with understanding and evaluating the effects of cleanup activities on species, populations, and ecosystems. While engineers and managers understand the processes involved in different remediation types such as capping, pump and treat, and natural attenuation, there is often a disconnect between (1) how ecologists view the influence of different types of remediation, (2) how the public perceives them, and (3) how engineers understand them. The overall goal of the present investigation was to define the components of remediation types (= functional remediation). Objectives were to (1) define andmore » describe functional components of remediation, regardless of the remediation type, (2) provide examples of each functional remediation component, and (3) explore potential effects of functional remediation components in the post-cleanup phase that may involve continued monitoring and assessment. Functional remediation components include types, numbers, and intensity of people, trucks, heavy equipment, pipes, and drill holes, among others. Several components may be involved in each remediation type, and each results in ecological effects, ranging from trampling of plants, to spreading invasive species, to disturbing rare species, and to creating fragmented habitats. In some cases remediation may exert a greater effect on ecological receptors than leaving the limited contamination in place. A goal of this conceptualization is to break down functional components of remediation such that managers, regulators, and the public might assess the effects of timing, extent, and duration of different remediation options on ecological systems.« less

Chemosensory Gene Families in Ectropis grisescens and Candidates for Detection of Type-II Sex Pheromones.

PubMed

Li, Zhao-Qun; Luo, Zong-Xiu; Cai, Xiao-Ming; Bian, Lei; Xin, Zhao-Jun; Liu, Yan; Chu, Bo; Chen, Zong-Mao

2017-01-01

Tea grey geometrid ( Ectropis grisescens ), a devastating chewing pest in tea plantations throughout China, produces Type-II pheromone components. Little is known about the genes encoding proteins involved in the perception of Type-II sex pheromone components. To investigate the olfaction genes involved in E . grisescens sex pheromones and plant volatiles perception, we sequenced female and male antennae transcriptomes of E . grisescens . After assembly and annotation, we identified 153 candidate chemoreception genes in E. grisescens , including 40 odorant-binding proteins (OBPs), 30 chemosensory proteins (CSPs), 59 odorant receptors (ORs), and 24 ionotropic receptors (IRs). The results of phylogenetic, qPCR, and mRNA abundance analyses suggested that three candidate pheromone-binding proteins (EgriOBP2, 3, and 25), two candidate general odorant-binding proteins (EgriOBP1 and 29), six pheromone receptors (EgriOR24, 25, 28, 31, 37, and 44), and EgriCSP8 may be involved in the detection of Type-II sex pheromone components. Functional investigation by heterologous expression in Xenopus oocytes revealed that EgriOR31 was robustly tuned to the E . grisescens sex pheromone component (Z,Z,Z)-3,6,9-octadecatriene and weakly to the other sex pheromone component (Z,Z)-3,9-6,7-epoxyoctadecadiene. Our results represent a systematic functional analysis of the molecular mechanism of olfaction perception in E . grisescens with an emphasis on gene encoding proteins involved in perception of Type-II sex pheromones, and provide information that will be relevant to other Lepidoptera species.

Chemosensory Gene Families in Ectropis grisescens and Candidates for Detection of Type-II Sex Pheromones

PubMed Central

Li, Zhao-Qun; Luo, Zong-Xiu; Cai, Xiao-Ming; Bian, Lei; Xin, Zhao-Jun; Liu, Yan; Chu, Bo; Chen, Zong-Mao

2017-01-01

Tea grey geometrid (Ectropis grisescens), a devastating chewing pest in tea plantations throughout China, produces Type-II pheromone components. Little is known about the genes encoding proteins involved in the perception of Type-II sex pheromone components. To investigate the olfaction genes involved in E. grisescens sex pheromones and plant volatiles perception, we sequenced female and male antennae transcriptomes of E. grisescens. After assembly and annotation, we identified 153 candidate chemoreception genes in E. grisescens, including 40 odorant-binding proteins (OBPs), 30 chemosensory proteins (CSPs), 59 odorant receptors (ORs), and 24 ionotropic receptors (IRs). The results of phylogenetic, qPCR, and mRNA abundance analyses suggested that three candidate pheromone-binding proteins (EgriOBP2, 3, and 25), two candidate general odorant-binding proteins (EgriOBP1 and 29), six pheromone receptors (EgriOR24, 25, 28, 31, 37, and 44), and EgriCSP8 may be involved in the detection of Type-II sex pheromone components. Functional investigation by heterologous expression in Xenopus oocytes revealed that EgriOR31 was robustly tuned to the E. grisescens sex pheromone component (Z,Z,Z)-3,6,9-octadecatriene and weakly to the other sex pheromone component (Z,Z)-3,9-6,7-epoxyoctadecadiene. Our results represent a systematic functional analysis of the molecular mechanism of olfaction perception in E. grisescens with an emphasis on gene encoding proteins involved in perception of Type-II sex pheromones, and provide information that will be relevant to other Lepidoptera species. PMID:29209233

Practical implementation, characterization and applications of a multi-colour time-gated luminescence microscope.

PubMed

Zhang, Lixin; Zheng, Xianlin; Deng, Wei; Lu, Yiqing; Lechevallier, Severine; Ye, Zhiqiang; Goldys, Ewa M; Dawes, Judith M; Piper, James A; Yuan, Jingli; Verelst, Marc; Jin, Dayong

2014-10-13

Time-gated luminescence microscopy using long-lifetime molecular probes can effectively eliminate autofluorescence to enable high contrast imaging. Here we investigate a new strategy of time-gated imaging for simultaneous visualisation of multiple species of microorganisms stained with long-lived complexes under low-background conditions. This is realized by imaging two pathogenic organisms (Giardia lamblia stained with a red europium probe and Cryptosporidium parvum with a green terbium probe) at UV wavelengths (320-400 nm) through synchronization of a flash lamp with high repetition rate (1 kHz) to a robust time-gating detection unit. This approach provides four times enhancement in signal-to-background ratio over non-time-gated imaging, while the average signal intensity also increases six-fold compared with that under UV LED excitation. The high sensitivity is further confirmed by imaging the single europium-doped Y₂O₂S nanocrystals (150 nm). We report technical details regarding the time-gating detection unit and demonstrate its compatibility with commercial epi-fluorescence microscopes, providing a valuable and convenient addition to standard laboratory equipment.

Practical Implementation, Characterization and Applications of a Multi-Colour Time-Gated Luminescence Microscope

NASA Astrophysics Data System (ADS)

Zhang, Lixin; Zheng, Xianlin; Deng, Wei; Lu, Yiqing; Lechevallier, Severine; Ye, Zhiqiang; Goldys, Ewa M.; Dawes, Judith M.; Piper, James A.; Yuan, Jingli; Verelst, Marc; Jin, Dayong

2014-10-01

Time-gated luminescence microscopy using long-lifetime molecular probes can effectively eliminate autofluorescence to enable high contrast imaging. Here we investigate a new strategy of time-gated imaging for simultaneous visualisation of multiple species of microorganisms stained with long-lived complexes under low-background conditions. This is realized by imaging two pathogenic organisms (Giardia lamblia stained with a red europium probe and Cryptosporidium parvum with a green terbium probe) at UV wavelengths (320-400 nm) through synchronization of a flash lamp with high repetition rate (1 kHz) to a robust time-gating detection unit. This approach provides four times enhancement in signal-to-background ratio over non-time-gated imaging, while the average signal intensity also increases six-fold compared with that under UV LED excitation. The high sensitivity is further confirmed by imaging the single europium-doped Y2O2S nanocrystals (150 nm). We report technical details regarding the time-gating detection unit and demonstrate its compatibility with commercial epi-fluorescence microscopes, providing a valuable and convenient addition to standard laboratory equipment.

Parasitic infections associated with malignancy and leprosy.

PubMed

Azab, M E; Mohamed, N H; Salem, S A; Safar, E H; Bebars, M A; Sabry, N M; Mohamed, M S

1992-04-01

Results of parasitic infections, as revealed by urine and stool examination was significant (P less than 0.05) in 43.3% of patients suffering from different malignant diseases and non significant (P greater than 0.05) in 29.3% of leprosy patients compared to 22% in control subjects. The most prevalent parasites were E. histolytica and G. lamblia. Cryptosporidium occysts were not detected. By stool examination and culture, S. stercoralis larvae were detected only in the malignancy group. The most common parasites occurring concomitantly were A. duodenale and S. stercoralis. By the IFAT, strongyloidiasis gave significantly higher positive results in the malignancy group than in the leprosy and control groups. IFAT for toxocariasis, showed highly significant positivity in the leprosy group and significantly positivity in the malignancy group. For toxoplasmosis, it showed highly significant positive results in both leprosy and malignancy groups. Eosinophilia was significantly more prominent among malignancy patients and insignificant among those with leprosy. Parasitic infection detected by urine and stool examination among patients with eosinophilia was found in 76% of the malignancy patients and in 66.7% of the leprosy patients.

Retention of pharmaceutical residues and microorganisms at the Altendorf retention soil filter.

PubMed

Christoffels, E; Mertens, F M; Kistemann, T; Schreiber, C

2014-01-01

A study has been conducted on a retention soil filter (RSF) to test its effectiveness in removing pharmaceutical residues and microorganisms from combined sewer overflows (CSOs). Efficient removal of solids, nutrients and heavy metals has already been proven. The possibility that organic micropollutants and microorganisms are also retained by the use of RSFs has been identified, but data are lacking. Results obtained in this study, in which testing for removal by a RSF of numerous micro-pollutant substances was performed, are most promising. The pharmaceuticals diclofenac and ibuprofen are presented in detail as examples of such micropollutants. Both showed a reduction in positive samples of more than 55% as well as a significant reduction in median and maximum concentrations. For microorganisms such as Escherichia coli, coliphages and Giardia lamblia (cysts), an average reduction in concentrations by three logarithmic steps (99.9%) was achieved. These results add to the evidence that using a RSF in the advanced treatment of wastewater from CSOs reduces the exposure of water-courses to pharmaceutical residues and microbial contamination.

A large community outbreak of gastroenteritis associated with consumption of drinking water contaminated by river water, Belgium, 2010.

PubMed

Braeye, T; DE Schrijver, K; Wollants, E; van Ranst, M; Verhaegen, J

2015-03-01

SUMMARY On 6 December 2010 a fire in Hemiksem, Belgium, was extinguished by the fire brigade with both river water and tap water. Local physicians were asked to report all cases of gastroenteritis. We conducted a retrospective cohort study among 1000 randomly selected households. We performed a statistical and geospatial analysis. Human stool samples, tap water and river water were tested for pathogens. Of the 1185 persons living in the 528 responding households, 222 (18·7%) reported symptoms of gastroenteritis during the time period 6-13 December. Drinking tap water was significantly associated with an increased risk for gastroenteritis (relative risk 3·67, 95% confidence interval 2·86-4·70) as was place of residence. Campylobacter sp. (2/56), norovirus GI and GII (11/56), rotavirus (1/56) and Giardia lamblia (3/56) were detected in stool samples. Tap water samples tested positive for faecal indicator bacteria and protozoa. The results support the hypothesis that a point-source contamination of the tap water with river water was the cause of the multi-pathogen waterborne outbreak.

Intestinal parasites in cancer patients in the South of Brazil.

PubMed

Jeske, S; Bianchi, T F; Moura, M Q; Baccega, B; Pinto, N B; Berne, M E A; Villela, M M

2017-11-27

Intestinal parasitic infections in immunocompromised patients can lead to serious complications when not diagnosed and treated early. This study aimed to investigate the frequency of intestinal parasites in cancer patients undergoing chemotherapy in the South of Brazil. Three fecal samples collected from each patient (73 individuals) were processed by Ritchie and Faust techniques and submitted to specific staining methods for intestinal protozoa. A 61.6% parasite and/or commensal positivity was found. Helminths identified were Ascaris lumbricoides (33.3%), Taenia spp. (6.6%), Strongyloides stercoralis (4.4%) and Trichuris trichiura (2.2%). Among protozoans, Giardia lamblia (26.6%), Cryptosporidium spp. (13.3%) and Cystoisospora belli (4.4%) were identified. The presence of Entamoeba coli, Endolimax nana and Entamoeba hartmanni was also recorded. The results obtained warn of the importance of fecal parasitological diagnosis and the use of specific staining methods for the detection of intestinal parasites in cancer patients. These exams should be regularly requested at the patient's first clinic visit, given the high prevalence found in this study and the possible severity of such conditions for these individuals.

Cryptosporidium and Giardia in Humans, Domestic Animals, and Village Water Sources in Rural India.

PubMed

Daniels, Miles E; Shrivastava, Arpit; Smith, Woutrina A; Sahu, Priyadarshi; Odagiri, Mitsunori; Misra, Pravas R; Panigrahi, Pinaki; Suar, Mrutyunjay; Clasen, Thomas; Jenkins, Marion W

2015-09-01

Cryptosporidium parvum and Giardia lamblia are zoonotic enteric protozoa of significant health concern where sanitation, hygiene, and water supplies are inadequate. We examined 85 stool samples from diarrhea patients, 111 pooled fecal samples by species across seven domestic animal types, and water from tube wells (N = 207) and ponds (N = 94) across 60 villages in coastal Odisha, India, for Cryptosporidium oocysts and Giardia cysts to measure occurrence, concentration/shedding, and environmental loading rates. Oocysts/cysts were detected in 12% of diarrhea patients. Detection ranged from 0% to 35% for Cryptosporidium and 0% to 67% for Giardia across animal hosts. Animal loading estimates indicate the greatest contributors of environmental oocysts/cysts in the study region are cattle. Ponds were contaminated with both protozoa (oocysts: 37%, cysts: 74%), as were tube wells (oocysts: 10%, cysts: 14%). Future research should address the public health concern highlighted from these findings and investigate the role of domestic animals in diarrheal disease transmission in this and similar settings. © The American Society of Tropical Medicine and Hygiene.

[Cryptosporidium sp infections and other intestinal parasites in food handlers from Zulia state, Venezuela].

PubMed

Freites, Azael; Colmenares, Deisy; Pérez, Marly; García, María; Díaz de Suárez, Odelis

2009-03-01

Cryptosporidiosis in food handlers from Venezuela is unknown, being this an important public health problem in immunosuppressed patients. To determine the prevalence of Cryptosporidium sp and other intestinal parasites in food handlers from Zulia State, one hundred nineteen fecal samples were evaluated by wet mount, concentrated according to Ritchie and modified Ziehl-Neelsen staining. Fourteen (11.8%) were positive for Cryptosporidium sp and associated with other protozoosis (P < 0.05), being most frequent Endolimax nana (42.9%). The general prevalence of the intestinal parasitism was 48.7%, emphasizing E. nana (41.2%), followed by Blastocystis hominis (38.7%) and Entamoeba coli (17.6%). The most frequent pathogenic protozoa was Giardia lamblia (13.4%), followed by the complex Entamoeba histolytica/E. dispar (9.2%). 4.1% were positive for intestinal helminthes. The infection by Cryptosporidium sp is frequent in food handlers from Zulia State. Given to the results of this investigation and the nonexistence of studies in this population, is necessary to deepen in the impact of this parasitism in food handlers and the consumers of their products.

Intestinal parasitosis among Yemeni patients with cancer, Sana'a, Yemen.

PubMed

Al-Qobati, Salah A; Al-Maktari, Mohamed T; Al-Zoa, Abdulla M Bin; Derhim, Mohamed

2012-12-01

The profile of intestinal parasitosis was assessed among patients on anticancer chemotherapy in Sana'a city, Yemen during the period from April to December 2011. A total of 206 patients (115 males & 91 females), aged 3 to 18 years with mean of 14.17 +/- 3.13 were subjected to stool examinations by different techniques. The overall rate of intestinal parasites was 63.1%. Cryptosporidium parvum was the highest (30.1%) followed by G. lamblia (18.0%) and then C. cayetanensis (5.3%). Blastocystis hominis and E. histolytica/dispar were detected in 4.9% & 2.4% respectively. E. coli, H. nana and A. lumbricoides were diagnosed in an equal of 1.5% and S. stercoralis was seen in one case only. The majority of infected patients suffered from diarrhea. They showed 4.64 risk of protozoan infections compared to those who passed formed stool with statistically significant difference. Diarrhea was associated with higher risk of cryptosporidiosis and giardiasis (OR = 2.73 & 2.67 respectively). The risk of intestinal parasitosis neither differed significantly with patients' age nor sex.

Intestinal parasitosis: data analysis 2006-2011 in a teaching hospital of Ancona, Italy.

PubMed

Silvestri, Carmela; Greganti, Gianfranco; Arzeni, Daniela; Morciano, Angela; Castelli, Pamela; Barchiesi, Francesco; Cirioni, Oscar; Giacometti, Andrea

2013-03-01

Intestinal parasites are a serious problem in developing countries, but should not be underestimated in industrialised countries either. Between January 2006 and December 2011, stool specimens and the scotch tests of 5323 Italian and non Italian patients (adults and children) attending the laboratory of our Infectious Diseases Clinic in a teaching Hospital at Ancona were analyzed specifically for intestinal parasites. The present study shows that, over a six-year period, of a total of 5323 patients 305 harboured at least one species of parasite (5.7%). Among the pathogenic protozoa Giardia lamblia was the most common, the overall prevalence of giardiasis being 1.8 % (99/5323). Helminths were found in 0.9% of the patients (48/5323). In particular, Hymenolepis nana, Strongyloides stercoralis and Trichuris trichiura were most commonly recovered in non-Italian children, suggesting that certain intestinal parasites are restricted to endemic areas in the tropics. Eighteen of the 305 infected patients had more than one parasite in their stools. Our study demonstrates that intestinal parasites must be considered even in industrialised areas and stool examination should be supported by epidemiological data and clinical features.

The Prevalence of Blastocystis hominis and Other Protozoan Parasites in Soldiers Returning from Peacekeeping Missions

PubMed Central

Duda, Aleksandra; Kosik-Bogacka, Danuta; Lanocha-Arendarczyk, Natalia; Kołodziejczyk, Lidia; Lanocha, Aleksandra

2015-01-01

Blastocystis hominis is a common intestinal parasite found in humans living in poor sanitary conditions, living in tropical and subtropical climates, exposed to infected animals, or consuming contaminated food or water. The aim of this study was to determine the prevalence of B. hominis in Polish military personnel returning from peacekeeping missions in Iraq and Afghanistan. In total, 1,826 stool samples were examined. Gastrointestinal parasites were detected in 17% of the soldiers. The examined stool samples most frequently contained vacuolar forms of B. hominis (15.3%) and cysts of Entamoeba coli (1.0%) or Giardia lamblia (0.7%). In 97.1% of stool samples from infected soldiers, we observed less than five developmental forms of B. hominis in the field of view (40×). The parasite infections in soldiers were diagnosed in the autumn and the spring. There was no statistical correlation between age and B. hominis infection. Our results show that peacekeeping missions in countries with tropical or subtropical climates could be associated with risk for parasitic diseases, including blastocystosis. PMID:25732683

Pulverized glass as an alternative filter medium

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

Piccirillo, J.B.; Letterman, R.D.

1998-07-01

A significant amount of low-value, recycled glass is stockpiled at recycling facilities or landfilled. This study was conducted to investigate the use of pulverized recycled glass as a filter medium in slow sand filtration. The glass was pulverized using a flail mill-type pulverizer. The size distribution of the pulverizer output was adjusted by sieving to meet the grain size requirements of the Ten States Standards and the USEPA for filter media were compared to a fourth unit containing silica sand media. The filter influent was spiked with clay, coliform group bacteria and the cysts and oocyst of Giardia lamblia andmore » Cryptosporidium parvum. Over an 8 month period of continuous operation, the performance of the glass sand filter media was as good as or better than the silica sand, with removals of 56% to 96% for turbidity; 99.78% to 100.0% for coliform bacteria; 99.995% to 99.997% for giardia cysts; and 99.92% to 99.97% for cryptosporidium oocysts. According to a cost-benefit analysis, converting waste glass into filter media may be economically advantageous for recycling facilities.« less

Analysis of Sir2E in the cellular slime mold Dictyostelium discoideum: cellular localization, spatial expression and overexpression.

PubMed

Katayama, Takahiro; Yasukawa, Hiro

2008-10-01

It has been reported that Dictyostelium discoideum encodes four silent information regulator 2 (Sir2) proteins (Sir2A-D) showing sequence similarity to human homologues of Sir2 (SIRT1-3). Further screening in a database revealed that D. discoideum encodes an additional Sir2 homologue (Sir2E). The amino acid sequence of Sir2E is not similar to those of SIRTs but is similar to those of proteins encoded by Giardia lamblia, Cryptosporidium hominis and Cryptosporidium parvum. Fluorescence of Sir2E-green fluorescent protein fusion protein was detected in the D. discoideum nucleus, indicating that Sir2E is a nuclear localizing protein. Reverse transcription-polymerase chain reaction and whole-mount in situ hybridization analyses showed that D. discoideum expressed sir2E in amoebae in the growth phase and in prestalk cells in the developmental phase. D. discoideum overexpressing sir2E grew faster than the wild type. These results indicate that Sir2E plays important roles both in the growth phase and developmental phase of D. discoideum.

Intestinal Parasitic Infestation in Combatants and Their Families: A Hospital-Based Study in Mid-Western Regional Police Hospital, Nepal

PubMed Central

Paudel, Damodar; Aung, Myo Nyein; Sharma, Bindhya; Aung, Thin Nyein Nyein; Moolphate, Saiyud

2014-01-01

Objective: To find out the scenario of intestinal parasitic infestation in combatants and their families in the setting of Mid-Western Regional Police Hospital (MWRPH), Nepal. Study Design: Cross-sectional study. Methods: All 2005 patients presented with the complaint of abdominal pain, diarrhoea, frequent defecation, blood in stool, or black stool from August 2007 to February 2011 were offered a stool examination. About 10g of fresh stool was collected in a clean, dry bottle. Two slides from each specimen were examined applying light microscope in 10 and 40 uvf at Banke, Nepalgunj hospital laboratory. Result: Among 2005 patients, 928 (46.28%) were infested with either helminths and/or protozoa. 96% were single infestation. The most common infestation was Ascaris lumbricoides (48.06%) and the second was hook worm (18.97%). Most common protozoal infestations were Entamoeba histolytica (12.92%) and Giardia lamblia (9.49%). Helminthic infestations peaked in cool months and protozoal infestations were rather steady throughout the year. Conclusion: Very high parasitic infestation in least developed mid- western Nepal may need urgent public health intervention. PMID:24762341

Contributions to the initial development of a microelectromechanical loop heat pipe, which is based on coherent porous silicon

NASA Astrophysics Data System (ADS)

Cytrynowicz, Debra G.

The research project itself was the initiation of the development of a planar miniature loop heat pipe based on a capillary wick structure made of coherent porous silicon. Work on this project fell into four main categories, which were component fabrication, test system construction, characterization testing and test data collection, performance analysis and thermal modeling. Component fabrication involved the production of various components for the evaporator. When applicable, these components were to be produced by microelectronic and MEMS or microelectromechanical fabrication techniques. Required work involved analyses and, where necessary, modifications to the wafer processing sequence, the photo-electrochemical etching process, system and controlling computer program to make it more reliable, flexible and efficient. The development of more than one wick production process was also extremely necessary in the event of equipment failure. Work on developing this alternative also involved investigations into various details of the photo-electrochemical etching process itself. Test system construction involved the actual assembly of open and closed loop test systems. Characterization involved developing and administering a series of tests to evaluate the performance of the wicks and test systems. Although there were some indications that the devices were operating according to loop heat pipe theory, they were transient and unstable. Performance analysis involved the construction of a transparent evaporator, which enabled the visual observation of the phenomena, which occurred in the evaporator during operation. It also involved investigating the effect of the quartz wool secondary wick on the operation of the device. Observations made during the visualization study indicated that the capillary and boiling limits were being reached at extremely low values of input power. The work was performed in a collaborative effort between the Biomedical Nanotechnology Research Laboratory at the University of Toledo, the Center for Microelectronics and Sensors and MEMS at the University of Cincinnati and the Thermo-Mechanical Systems Branch of the Power and On-Board Propulsion Division at the John H. Glenn Research Center of the National Aeronautics and Space Administration in Cleveland, Ohio. Work on the project produced six publications, which presented various details on component fabrication, tests system construction and characterization and thermal modeling.

Teaching Software Componentization: A Bar Chart Java Bean

ERIC Educational Resources Information Center

Mitri, Michel

2010-01-01

In the current object-oriented paradigm, software construction increasingly involves creating and utilizing "software components". These components can serve a variety of functions, from common algorithmic processes to database connectivity to graphical interfaces. The advantage of component architectures is that programmers can use pre-existing…

Reassessing the causal structure of enduring involvement

Treesearch

Jinhee Jun; Gerard T. Kyle; James D. Absher; William E. Hammitt

2009-01-01

Guided by tenets of identity theory, we hypothesized a causal structure of enduring involvement suggesting that self-relevant components precede the other dimensions. We used Kyle et al.'s (2004a) Modified Involvement Scale, in which leisure involvement is conceptualized as a multidimensional construct consisting of identity affirmation, identity expression,...

A Model Parental Involvement Program for Bilingual/Bicultural Developmental Day Care.

ERIC Educational Resources Information Center

de Avila, Marcia Freedman

Parental involvement in migrant education is now being mandated across the country. Parental involvement in bilingual/bicultural day care is just as, if not more, important than involvement at the public school level. This study was conducted to test whether or not parental involvement could become an active component in a bilingual/bicultural day…

Method of using infrared radiation for assembling a first component with a second component

DOEpatents

Sikka, Vinod K.; Whitson, Barry G.; Blue, Craig A.

1999-01-01

A method of assembling a first component for assembly with a second component involves a heating device which includes an enclosure having a cavity for inserting a first component. An array of infrared energy generators is disposed within the enclosure. At least a portion of the first component is inserted into the cavity, exposed to infrared energy and thereby heated to a temperature wherein the portion of the first component is sufficiently softened and/or expanded for assembly with a second component.

The facilitated component of intestinal glucose absorption

PubMed Central

Kellett, George L

2001-01-01

Over the last decade, a debate has developed about the mechanism of the passive or ‘diffusive’ component of intestinal glucose absorption and, indeed, whether it even exists. Pappenheimer and colleagues have proposed that paracellular solvent drag contributes a passive component, which, at high concentrations of sugars similar to those in the jejunal lumen immediately after a meal, is severalfold greater than the active component mediated by the Na+-glucose cotransporter SGLT1. On the other hand, Ferraris & Diamond maintain that the kinetics of glucose absorption can be explained solely in terms of SGLT1 and that a passive or paracellular component plays little, if any, part. Recently, we have provided new evidence that the passive component of glucose absorption exists, but is in fact facilitated since it is mediated by the rapid, glucose-dependent activation and recruitment of the facilitative glucose transporter GLUT2 to the brush-border membrane; regulation involves a protein kinase C (PKC)-dependent pathway activated by glucose transport through SGLT1 and also involves mitogen-activated protein kinase (MAP kinase) signalling pathways. This topical review seeks to highlight the significant points of the debate, to show how our proposals on GLUT2 impact on different aspects of the debate and to look at the regulatory events that are likely to be involved in the short-term regulation of sugar absorption during the assimilation of a meal. PMID:11251042

Ethnicity in Black American Fiction.

ERIC Educational Resources Information Center

Steele, Shelby

1977-01-01

Ethnicity in the American context involves two components: the cultural component and the "outsider" component. The first consists of those customs, folkways, rituals, and values identified with a particular ethnic group and its unique patterns of living. The second is the feeling of being outside the mainstream politically, economically,…

Practical synthesis of phthalimides and benzamides by a multicomponent reaction involving arynes, isocyanides, and CO2/H2O.

PubMed

Kaicharla, Trinadh; Thangaraj, Manikandan; Biju, Akkattu T

2014-03-21

Transition-metal-free multicomponent reactions involving arynes and isocyanides with either CO2 or H2O have been reported. With CO2 as the third component, the reactions resulted in the formation of N-substituted phthalimides. The utility of water as the third component furnished benzamide derivatives in moderate to good yields. These reactions took place under mild conditions with broad scope.

Forensic engineering: applying materials and mechanics principles to the investigation of product failures.

PubMed

Hainsworth, S V; Fitzpatrick, M E

2007-06-01

Forensic engineering is the application of engineering principles or techniques to the investigation of materials, products, structures or components that fail or do not perform as intended. In particular, forensic engineering can involve providing solutions to forensic problems by the application of engineering science. A criminal aspect may be involved in the investigation but often the problems are related to negligence, breach of contract, or providing information needed in the redesign of a product to eliminate future failures. Forensic engineering may include the investigation of the physical causes of accidents or other sources of claims and litigation (for example, patent disputes). It involves the preparation of technical engineering reports, and may require giving testimony and providing advice to assist in the resolution of disputes affecting life or property.This paper reviews the principal methods available for the analysis of failed components and then gives examples of different component failure modes through selected case studies.

A Meta-Analysis: The Relationship between Father Involvement and Student Academic Achievement

ERIC Educational Resources Information Center

Jeynes, William H.

2015-01-01

A meta-analysis was undertaken, including 66 studies, to determine the relationship between father involvement and the educational outcomes of urban school children. Statistical analyses were done to determine the overall impact and specific components of father involvement. The possible differing effects of paternal involvement by race were also…

Antiprotozoal, antimycobacterial, and anti-inflammatory evaluation of Cnidoscolus chayamansa (Mc Vaugh) extract and the isolated compounds.

PubMed

Pérez-González, Mariana Z; Gutiérrez-Rebolledo, Gabriel A; Yépez-Mulia, Lilián; Rojas-Tomé, Irma S; Luna-Herrera, Julieta; Jiménez-Arellanes, María A

2017-05-01

Cnidoscolus chayamansa is a medicinal and edible plant known as Chaya, is commonly used as an anti-inflammatory, antiprotozoal, antibacterial agent and as a remedy for respiratory illness, gastrointestinal disorders, and vaginal infections related with the inflammation process. In this paper, we describe the plant's phytochemical analysis and biological activities (antimycobacterial, antibacterial, antiprotozoal, and anti-inflammatory properties) of the CHCl 3 :MeOH (1:1) leaves extract and isolated compounds, as well as the acute and sub-acute toxic effects. Chemical identification of isolated compounds was performed by 1 H- and 13 C NMR spectra data. In vitro antibacterial and antimycobacterial activities were determined by disc diffusion and MABA assays, respectively; antiprotozoal test by means of the sub-culture test. Topical and systemic anti-inflammatory effects were tested by TPA and carrageenan assay on BALB/c mice. Moretenol, moretenyl acetate, kaempferol-3,7-dimethyl ether, and 5-hydroxy-7-3',4'-trimethoxyflavanone were the main compounds isolated. The CHCl 3 :MeOH extract showed antiprotozoal (IC 50 ≤65.29μg/mL), antimycobacterial (MIC≤50μg/mL), and anti-inflammatory activities (ED 50 =1.66mg/ear and 467.73mg/kg), but was inactive against the bacterial strains tested. The LD 50 for extract was >2g/kg. In the sub-acute toxicity test, the extract was administered at 1g/kg for 28days and did not cause lethality or any alteration in hematological and biochemical parameters; in addition, liver, kidney, and spleen histological analysis exhibited no structural changes. Moretenol and moretenyl acetate showed MIC=25μg/mL against Mycobacterium tuberculosis H37Rv and against four monoresistant strains of M. tuberculosis H37Rv. Both compounds exhibited moderate activity against Entamoeba histolytica and Giardia lamblia (IC 50 ≤71.70μg/mL). Kaempferol-3,7-dimethyl ether and 5-hydroxy-7-3',4'-trimethoxy-flavanone were more active than the extract against E. histolytica and G. lamblia, showing IC 50 ≤27.43μg/mL. As topical anti-inflammatory agents, moretenol and kaempferol-3,7-dimethyl ether were the most active compounds inhibiting the edema in 30.52 and 26.67%, respectively. Moretenol and moretenyl acetate showed significant antimycobacterial and antiprotozoal activities; in addition, important antiprotozoal effect was detected with kaempferol-3,7-dimethyl ether and 5-hydroxy-7-3',4'-trimethoxyflavanone. The extract and the terpenoids possess good anti-inflammatory activity. The extract did not produce lethality or adverse effects in acute and sub-acute tests. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Individual Differences in Dual Task Performance. Final Report.

ERIC Educational Resources Information Center

Lansman, Marcy; Hunt, Earl

This report summarizes the research results and provides a reference. The basic question addressed was, "Is performance on multi-component tasks predicted by performance on the individual components performed separately?" In the first series of experiments, a dual task involving memory and verbal processing components to predict a…

The Driver Behaviour Questionnaire: a North American analysis.

PubMed

Cordazzo, Sheila T D; Scialfa, Charles T; Bubric, Katherine; Ross, Rachel Jones

2014-09-01

The Driver Behaviour Questionnaire (DBQ), originally developed in Britain by Reason et al. [Reason, J., Manstead, A., Stradling, S., Baxter, J., & Campbell, K. (1990). Errors and violations on the road: A real distinction? Ergonomics, 33, 1315-1332] is one of the most widely used instruments for measuring driver behaviors linked to collision risk. The goals of the study were to adapt the DBQ for a North American driving population, assess the component structure of the items, and to determine whether scores on the DBQ could predict self-reported traffic collisions. Of the original Reason et al. items, our data indicate a two-component solution involving errors and violations. Evidence for a Lapses component was not found. The 20 items most closely resembling those of Parker et al. [Parker, D., Reason, J. T., Manstead, A. S. R., & Stradling, S. G. (1995). Driving errors, driving violations and accident involvement. Ergonomics, 38, 1036-1048] yielded a solution with 3 orthogonal components that reflect errors, lapses, and violations. Although violations and Lapses were positively and significantly correlated with self-reported collision involvement, the classification accuracy of the resulting models was quite poor. A North American DBQ has the same component structure as reported previously, but has limited ability to predict self-reported collisions. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

Enhancing links between visual short term memory, visual attention and cognitive control processes through practice: An electrophysiological insight.

PubMed

Fuggetta, Giorgio; Duke, Philip A

2017-05-01

The operation of attention on visible objects involves a sequence of cognitive processes. The current study firstly aimed to elucidate the effects of practice on neural mechanisms underlying attentional processes as measured with both behavioural and electrophysiological measures. Secondly, it aimed to identify any pattern in the relationship between Event-Related Potential (ERP) components which play a role in the operation of attention in vision. Twenty-seven participants took part in two recording sessions one week apart, performing an experimental paradigm which combined a match-to-sample task with a memory-guided efficient visual-search task within one trial sequence. Overall, practice decreased behavioural response times, increased accuracy, and modulated several ERP components that represent cognitive and neural processing stages. This neuromodulation through practice was also associated with an enhanced link between behavioural measures and ERP components and with an enhanced cortico-cortical interaction of functionally interconnected ERP components. Principal component analysis (PCA) of the ERP amplitude data revealed three components, having different rostro-caudal topographic representations. The first component included both the centro-parietal and parieto-occipital mismatch triggered negativity - involved in integration of visual representations of the target with current task-relevant representations stored in visual working memory - loaded with second negative posterior-bilateral (N2pb) component, involved in categorising specific pop-out target features. The second component comprised the amplitude of bilateral anterior P2 - related to detection of a specific pop-out feature - loaded with bilateral anterior N2, related to detection of conflicting features, and fronto-central mismatch triggered negativity. The third component included the parieto-occipital N1 - related to early neural responses to the stimulus array - which loaded with the second negative posterior-contralateral (N2pc) component, mediating the process of orienting and focusing covert attention on peripheral target features. We discussed these three components as representing different neurocognitive systems modulated with practice within which the input selection process operates. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Involving Families in School Events

ERIC Educational Resources Information Center

Barrera, John M.; Warner, Laverne

2006-01-01

The relationship of schools to diverse communities demands attention by administrators, teachers, staff members, and volunteers. How well the three constructs mesh depends on the abilities and sensitivities of all constituencies involved. Three components are essential to successful programs that involve families in an educational setting:…

The Relationship between Parental Involvement and Urban Secondary School Student Academic Achievement: A Meta-Analysis

ERIC Educational Resources Information Center

Jeynes, William H.

2007-01-01

A meta-analysis is undertaken, including 52 studies, to determine the influence of parental involvement on the educational outcomes of urban secondary school children. Statistical analyses are done to determine the overall impact of parental involvement as well as specific components of parental involvement. Four different measures of educational…

Height as a Determinant of Submission and the Assignment of Responsibility.

ERIC Educational Resources Information Center

Hess, Harrie F.

Height is one important variable among many in the elicitation of the submissive response. In addition to overt behavioral components, the submissive response involves a cognitive component, in which oneself is perceived as smaller and weaker, and an affective component, consisting of a feeling of intimidation by the other. Submission is a…

Homework Involvement among Hong Kong Primary School Students

ERIC Educational Resources Information Center

Tam, Vicky C. W.

2009-01-01

One component of the curriculum reform in Hong Kong focuses on the use of homework in consolidating learning, deepening understanding and constructing knowledge. This study examines the profile of Hong Kong primary school students' homework involvement, and investigates the relationships between time involvement and academic attributes, namely…

Already at the Table: Patterns of Play and Gambling Involvement Prior to Gambling Expansion.

PubMed

Nelson, Sarah E; LaPlante, Debi A; Gray, Heather M; Tom, Matthew A; Kleschinsky, John H; Shaffer, Howard J

2018-03-01

During 2011, the Governor of Massachusetts signed a bill to allow casino gambling in the state (Commonwealth of Massachusetts 2011). As a result, two resort casinos will begin operations during 2018 and 2019; a smaller slots parlor began operations during June 2015. Prior to this expansion, gambling was widely available in Massachusetts, through the state lottery, off-track betting, and gambling opportunities available in neighboring states. Within this context, it is important to understand the patterns of gambling involvement in the population prior to gambling expansion. The current study examined gambling involvement, patterns of play, and gambling-related problems prior to gambling expansion among a sample of 511 Massachusetts residents who were members of a statewide Internet panel. To measure patterns of play, we asked questions about past-year games played and frequency of play. To measure breadth of involvement, we assessed the number of different games played. To measure depth of involvement, we measured time spent gambling, amount wagered, and amount won or lost. Principal component analysis revealed four play pattern components accounting for more than 50% of the variance in game play frequency. Multiple regression analyses revealed that component scores composed of casino gambling and skill-based gambling (e.g., poker, sports) variables uniquely contributed to the prediction of gambling-related problems, even when depth of involvement was controlled. However, the addition of breadth of involvement to the model resulted in a model where no set of variables contributed significantly, suggesting a complex relationship among play patterns, depth, and breadth of involvement. The study established discrete and distinguishable gambling play patterns associated with gambling-related problems and identified groups of individuals potentially vulnerable to the effects of gambling expansion.

Meeting the Challenge of Involving Parents in School. Newsletter

ERIC Educational Resources Information Center

Center for Comprehensive School Reform and Improvement, 2005

2005-01-01

Parent involvement continues to challenge practitioners engaged in school reform despite being a required component of many school improvement initiatives--from Title I Schoolwide Programs to federally mandated school improvement plans. The benefits of parent involvement are clear: A growing body of research shows that successful parent…

Multi-Dimensional Parental Involvement in Schools: A Principal's Guide

ERIC Educational Resources Information Center

Rapp, Nicole; Duncan, Heather

2012-01-01

Parental involvement is an important indicator of students' success in school. When schools engage families in a manner connected to improving learning, students do make greater gains. Creating and implementing an effective parental involvement model is an essential component in increasing student achievement in school. This article addresses the…

Report of Total Involvement Professional Semester TIPS.

ERIC Educational Resources Information Center

Payne, James I.

The goal of the Total Involvement Professional Semester (TIPS) was to allow elementary education students at Shippensburg State College to become involved in an educational environment in a meaningful way to develop their professional knowledge and skills. The experimental program consisted of five important components: a) three weeks of…

The Evaluation Exchange. Volume 14, Numbers 1-2 Spring 2008

ERIC Educational Resources Information Center

Bouffard, Suzanne, Ed; Weiss, Abby; DeDeo, Carrie-Anne, Ed.

2008-01-01

This issue of "The Evaluation Exchange" spotlights one of the central components of complementary learning: family involvement. There are 28 articles herein: (1) "Thinking Big: A New Framework for Family Involvement Policy, Practice, and Research" (Suzanne Bouffard and Heather Weiss) reframes family involvement as part of a broader complementary…

Continuity and Variability in the Parental Involvement and Advocacy Beliefs of Latino Families of Young Children: Finding the Potential for a Collective Voice

ERIC Educational Resources Information Center

Durand, Tina M.; Perez, Nicole A.

2013-01-01

Parental involvement is an important component of children's school success. Although the literature on parental involvement among Latino families is growing and moving from deficit-based perspectives, very few studies have examined the parental involvement beliefs and practices of Latino families who vary across demographic and sociocultural…

Dissecting components of population-level variation in seed production and the evolution of masting behavior.

Treesearch

W. D. Koenig; D. Kelly; V. L. Sork; R. P. Duncan; J. S. Elkinton; M.S. Peltonen; R. D. Westfall

2003-01-01

Mast-fruiting or masting behavior is the cumulative result of the reproductive patterns of individuals within a population and thus involves components of individual variability, between-individual synchrony, and endogenous cycles of temporal autocorrelation. Extending prior work by Herrera, we explore the interrelationships of these components using data on individual...

The enabling technology for recovery of valued components from minerals in the upper and Mid Amur region

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

Sorokin, A.P.; Rimkevich, V.S.; Dem'yanova, L.P.

2009-05-15

Based on the physico-technical operations involved in the mineral processing technologies, the optimal production conditions are found for refractory fiber materials, aluminium, silicium, their compounds and other valued components. Ecologically safe and efficient aggregate technologies are developed for recovery of valued components from nonmetallic minerals and anthracides (brown coals).

Two Genetic Loci Produce Distinct Carbohydrate-Rich Structural Components of the Pseudomonas aeruginosa Biofilm Matrix

PubMed Central

Friedman, Lisa; Kolter, Roberto

2004-01-01

Pseudomonas aeruginosa forms biofilms, which are cellular aggregates encased in an extracellular matrix. Molecular genetics studies of three common autoaggregative phenotypes, namely wrinkled colonies, pellicles, and solid-surface-associated biofilms, led to the identification of two loci, pel and psl, that are involved in the production of carbohydrate-rich components of the biofilm matrix. The pel gene cluster is involved in the production of a glucose-rich matrix material in P. aeruginosa strain PA14 (L. Friedman and R. Kolter, Mol. Microbiol. 51:675-690, 2004). Here we investigate the role of the pel gene cluster in P. aeruginosa strain ZK2870 and identify a second genetic locus, termed psl, involved in the production of a mannose-rich matrix material. The 11 predicted protein products of the psl genes are homologous to proteins involved in carbohydrate processing. P. aeruginosa is thus able to produce two distinct carbohydrate-rich matrix materials. Either carbohydrate-rich matrix component appears to be sufficient for mature biofilm formation, and at least one of them is required for mature biofilm formation in P. aeruginosa strains PA14 and ZK2870. PMID:15231777

Two genetic loci produce distinct carbohydrate-rich structural components of the Pseudomonas aeruginosa biofilm matrix.

PubMed

Friedman, Lisa; Kolter, Roberto

2004-07-01

Pseudomonas aeruginosa forms biofilms, which are cellular aggregates encased in an extracellular matrix. Molecular genetics studies of three common autoaggregative phenotypes, namely wrinkled colonies, pellicles, and solid-surface-associated biofilms, led to the identification of two loci, pel and psl, that are involved in the production of carbohydrate-rich components of the biofilm matrix. The pel gene cluster is involved in the production of a glucose-rich matrix material in P. aeruginosa strain PA14 (L. Friedman and R. Kolter, Mol. Microbiol. 51:675-690, 2004). Here we investigate the role of the pel gene cluster in P. aeruginosa strain ZK2870 and identify a second genetic locus, termed psl, involved in the production of a mannose-rich matrix material. The 11 predicted protein products of the psl genes are homologous to proteins involved in carbohydrate processing. P. aeruginosa is thus able to produce two distinct carbohydrate-rich matrix materials. Either carbohydrate-rich matrix component appears to be sufficient for mature biofilm formation, and at least one of them is required for mature biofilm formation in P. aeruginosa strains PA14 and ZK2870. Copyright 2004 American Society for Microbiology

IMMUNOREACTIONS INVOLVING PLATELETS

PubMed Central

Shulman, N. Raphael

1958-01-01

A steric and kinetic model for the sequence and mechanism of reactions leading to formation of a complex from an antibody, a haptene (quinidine), and a cell membrane (platelets), and to fixation of complement by the complex was deduced from the effects of varying the initial concentration of each component of the complex on the amount of complement fixed, from kinetic aspects of the sequential reactions, and from other chemical and physical properties of the various components involved. Theoretical results calculated using equations based on the model, which were derived by Dr. Terrell L. Hill, were similar in all respects to experimental results. Results of this study were consistent with the possibilities that the protein moiety of a haptenic antigen involved in development of an antibody which attaches to a cell is not necessarily a component of the cell, and that the cell reacts with the antibody by virtue of having a surface favorable for non-specific adsorption of certain haptene-antibody complexes. PMID:13525578

A qualitative study of DRG coding practice in hospitals under the Thai Universal Coverage scheme.

PubMed

Pongpirul, Krit; Walker, Damian G; Winch, Peter J; Robinson, Courtland

2011-04-08

In the Thai Universal Coverage health insurance scheme, hospital providers are paid for their inpatient care using Diagnosis Related Group-based retrospective payment, for which quality of the diagnosis and procedure codes is crucial. However, there has been limited understandings on which health care professions are involved and how the diagnosis and procedure coding is actually done within hospital settings. The objective of this study is to detail hospital coding structure and process, and to describe the roles of key hospital staff, and other related internal dynamics in Thai hospitals that affect quality of data submitted for inpatient care reimbursement. Research involved qualitative semi-structured interview with 43 participants at 10 hospitals chosen to represent a range of hospital sizes (small/medium/large), location (urban/rural), and type (public/private). Hospital Coding Practice has structural and process components. While the structural component includes human resources, hospital committee, and information technology infrastructure, the process component comprises all activities from patient discharge to submission of the diagnosis and procedure codes. At least eight health care professional disciplines are involved in the coding process which comprises seven major steps, each of which involves different hospital staff: 1) Discharge Summarization, 2) Completeness Checking, 3) Diagnosis and Procedure Coding, 4) Code Checking, 5) Relative Weight Challenging, 6) Coding Report, and 7) Internal Audit. The hospital coding practice can be affected by at least five main factors: 1) Internal Dynamics, 2) Management Context, 3) Financial Dependency, 4) Resource and Capacity, and 5) External Factors. Hospital coding practice comprises both structural and process components, involves many health care professional disciplines, and is greatly varied across hospitals as a result of five main factors.

Graduated driver licensing programs and fatal crashes of 16-year-old drivers: a national evaluation.

PubMed

Chen, Li-Hui; Baker, Susan P; Li, Guohua

2006-07-01

Implementation of graduated driver licensing programs is associated with reductions in crash rates of young drivers, but graduated driver licensing programs vary in their components. The impact of programs with different components is unknown. The purpose of this work was to determine which graduated driver licensing programs are associated with the greatest reductions in fatal motor vehicle crashes involving 16-year-old drivers. We conducted a retrospective study of all 16-year-old drivers involved in fatal crashes in the United States from 1994 through 2004 using data from the Fatality Analysis Reporting System and the US Census Bureau. We measured incidence rate ratios of fatal motor vehicle crashes involving 16-year-old drivers according to graduated driver licensing programs, adjusted for state and year. Compared with state quarters with no graduated driver licensing program components, reductions of 16% to 21% in fatal crash involvement rates of 16-year-old drivers occurred with programs that included > or = 3-month mandatory waiting period, nighttime driving restriction, and either > or = 30 hours of supervised driving or passenger restriction. Reductions of 18% to 21% occurred in state quarters with programs that included > or = 5 of the 7 components examined. Drivers aged 20 to 24 or 25 to 29 years did not experience significant reductions. Comprehensive graduated driver licensing programs are associated with reductions of approximately 20% in 16-year-old drivers' fatal crash involvement rates. The greatest benefit seems to be associated with programs that include age requirements and > or = 3 months of waiting before the intermediate stage, nighttime driving restriction, and either > or = 30 hours of supervised driving or passenger restriction.

A qualitative study of DRG coding practice in hospitals under the Thai Universal Coverage Scheme

PubMed Central

2011-01-01

Background In the Thai Universal Coverage health insurance scheme, hospital providers are paid for their inpatient care using Diagnosis Related Group-based retrospective payment, for which quality of the diagnosis and procedure codes is crucial. However, there has been limited understandings on which health care professions are involved and how the diagnosis and procedure coding is actually done within hospital settings. The objective of this study is to detail hospital coding structure and process, and to describe the roles of key hospital staff, and other related internal dynamics in Thai hospitals that affect quality of data submitted for inpatient care reimbursement. Methods Research involved qualitative semi-structured interview with 43 participants at 10 hospitals chosen to represent a range of hospital sizes (small/medium/large), location (urban/rural), and type (public/private). Results Hospital Coding Practice has structural and process components. While the structural component includes human resources, hospital committee, and information technology infrastructure, the process component comprises all activities from patient discharge to submission of the diagnosis and procedure codes. At least eight health care professional disciplines are involved in the coding process which comprises seven major steps, each of which involves different hospital staff: 1) Discharge Summarization, 2) Completeness Checking, 3) Diagnosis and Procedure Coding, 4) Code Checking, 5) Relative Weight Challenging, 6) Coding Report, and 7) Internal Audit. The hospital coding practice can be affected by at least five main factors: 1) Internal Dynamics, 2) Management Context, 3) Financial Dependency, 4) Resource and Capacity, and 5) External Factors. Conclusions Hospital coding practice comprises both structural and process components, involves many health care professional disciplines, and is greatly varied across hospitals as a result of five main factors. PMID:21477310

Rethinking geochemical feature of the Afar and Kenya mantle plumes and geodynamic implications

NASA Astrophysics Data System (ADS)

Meshesha, Daniel; Shinjo, Ryuichi

2008-09-01

We discuss the spatial and temporal variation in the geochemistry of mantle sources which were sampled by the Eocene to Quaternary mafic magmas in the vicinity of the Afar and Kenya plume upwelling zones, East Africa. Despite the contributions of lithospheric and crustal sources, carefully screened Eocene to Quaternary mafic lavas display wide range of Sr-Nd-Pb isotopic and incompatible trace elemental compositions that can be attributed to significant intraplume heterogeneity. The geochemical variations reflect the involvement of at least four mantle plume components as sources for the northeastern Africa magmatism: (1) isotopically depleted but trace element-enriched component; (2) component characterized by radiogenic Pb isotope signatures (HIMU?); (3) enriched mantle-like component; and (4) high-3He/4He-type (as HT2-type basalts) plume component. The first component disappears in the Miocene-Quaternary magmatism, and the second component is hardly recognized after the eruption of Miocene basalt in southern Ethiopia. Plume-unrelated depleted asthenosphere starts to involve at a nascent stage of seafloor spreading centers in the Red Sea and Gulf of Aden. The other two-plume components have persisted from the late Eocene to present, but their proportions have changed through time and space. We propose a model of multiple impingements of plumelets within the broad upwelling zone connected to the African Superplume in the lower mantle beneath southern Africa. The plumelet contains a matrix of high-3He/4He-type component with blobs, streaks, or ribbons of other components.

Selecting candidate structures for lithium treatment : what to provide the petrographer along with concrete specimens : tech brief.

DOT National Transportation Integrated Search

2006-02-01

The process of selecting candidate structures (and : appropriate components of structures) for lithium treatment : invariably involves sampling one or several components : of the structures for laboratory investigations, particularly : petrographic e...

Evaluation of long carbon fiber reinforced concrete to mitigate earthquake damage of infrastructure components.

DOT National Transportation Integrated Search

2013-06-01

The proposed study involves investigating long carbon fiber reinforced concrete as a method of mitigating earthquake damage to : bridges and other infrastructure components. Long carbon fiber reinforced concrete has demonstrated significant resistanc...

Examining Involvement as a Critical Factor: Perceptions from First Generation and Non-First Generation College Students

ERIC Educational Resources Information Center

Davenport, Mona Yvette

2010-01-01

This study tested the perceptions of involvement components (Non-Academic Facility Usage, Intra-Racial Relations, Campus and Charleston Involvement, Faculty Interaction, Academic Facility Usage, Inter-Racial Relations, Cultural Center Usage, and Athletic Facilities Usage) for first generation and non-first generation African American and Hispanic…

Building the Future of Family Involvement. The Evaluation Exchange. Volume 14, Numbers 1-2, Spring 2008

ERIC Educational Resources Information Center

DeDeo, Carrie-Anne, Ed.

2007-01-01

This double issue of "The Evaluation Exchange" focuses on one of the central components of complementary learning: family involvement. As outlined in the Theory & Practice article, investments in family involvement are important across ages and settings and through the co-constructed efforts and shared responsibilities of many…

Guidelines for Parent Involvement in Chapter 1 Programs.

ERIC Educational Resources Information Center

Weckstein, Paul

Chapter 1 is the largest federal education program in existence. It provides extra services to help low-achieving students and is targeted primarily at areas where low-income families reside. Parent involvement in designing and implementing the program is an essential part of Chapter 1. However, the parent involvement component is often not as…

Collaborating with Families from Diverse Cultural and Linguistic Backgrounds: Considering Time and Communication Orientations

ERIC Educational Resources Information Center

Cheatham, Gregory A.; Santos, Rosa Milagros

2011-01-01

Parents' involvement in their children's education influences the children's educational success and is regarded as best practice in early childhood. A critical component in increasing parental involvement is effective collaboration between teacher and family. This involves being friendly, honest, and clear; listening and providing information;…

Identifying Barriers That Hinder Onsite Parental Involvement in a School-Based Health Promotion Program

PubMed Central

Garcia-Dominic, Oralia; Wray, Linda A.; Treviño, Roberto P.; Hernandez, Arthur E.; Yin, Zenong; Ulbrecht, Jan S.

2009-01-01

We investigated whether barriers to onsite parental involvement in the Bienestar Health Program Parent Component could be identified and whether participation rates could be increased by addressing these barriers. All nonparticipating parents of fourth-grade students of San Antonio Independent School District from 4 schools, which were selected randomly from 20 intervention schools in Bienestar, were invited to take part in this study. A total of 47 of 223 (21%) parents engaged in one of four focus groups offered. Parents identified barriers to their involvement in Bienestar that fit into five descriptive categories: (a) low value, (b) high cost, (c) competing family demands, (d) concerns about the program design, and (e) social role norms. The Bienestar Parent Component was then modified according to the focus group findings, which resulted in a marked increase in parental involvement from 17% to 37% overall. These findings suggest that even when parents are involved in the initial design of parent-friendly and culturally sensitive programs, as was the case for Bienestar, maximizing parental involvement may require additional assessment, identification, and remediation of barriers. PMID:19339644

Understanding Oral Reading Fluency among Adults with Low Literacy: Dominance Analysis of Contributing Component Skills

ERIC Educational Resources Information Center

Mellard, Daryl F.; Anthony, Jason L.; Woods, Kari L.

2012-01-01

This study extends the literature on the component skills involved in oral reading fluency. Dominance analysis was applied to assess the relative importance of seven reading-related component skills in the prediction of the oral reading fluency of 272 adult literacy learners. The best predictors of oral reading fluency when text difficulty was…

Engineering intelligent tutoring systems

NASA Technical Reports Server (NTRS)

Warren, Kimberly C.; Goodman, Bradley A.

1993-01-01

We have defined an object-oriented software architecture for Intelligent Tutoring Systems (ITS's) to facilitate the rapid development, testing, and fielding of ITS's. This software architecture partitions the functionality of the ITS into a collection of software components with well-defined interfaces and execution concept. The architecture was designed to isolate advanced technology components, partition domain dependencies, take advantage of the increased availability of commercial software packages, and reduce the risks involved in acquiring ITS's. A key component of the architecture, the Executive, is a publish and subscribe message handling component that coordinates all communication between ITS components.

Prevalence and risk factors for intestinal parasites in food handlers, southern Brazil.

PubMed

Colli, Cristiane Maria; Mizutani, Angelica Sayuri; Martins, Vanessa Aparecida; Ferreira, Erika Cristina; Gomes, Mônica Lúcia

2014-01-01

In this study, the prevalence and risk factors for enteroparasites were determined in food handlers from Maringá, Paraná State, southern Brazil. Fecal and subungual materials of 150 street food vendors were analyzed by the methods of Lutz, Faust, and Mello, respectively. A questionnaire on hygiene and sanitary conditions of the workplace and of domicile was applied. The prevalence of enteroparasites was 28%, and the protozoa infection was more expressive (21.3%) than by helminths (6.7%), but without significant difference (p > 0.05). Entamoeba coli was the most frequent species occurring in 15.3%, while the prevalence of protozoa pathogenic was low (Giardia lamblia: 2.7% and Entamoeba histolytica: 0.7%). The subungual material presented negative results. The presence of pets in domiciles has increased twice the risk of infection. The working conditions of the majority of street food vendors were inappropriate. The results highlight the need for more rigorous programs of continuing education, parasitological examination every six months, and health surveillance. In this way, the quality of the service provided to the population can be improved and the transmission of food-borne diseases can be prevented.

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

PubMed

Exner, M; Gornik, V

2004-07-01

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

Mining the Giardia genome and proteome for conserved and unique basal body proteins

PubMed Central

Lauwaet, Tineke; Smith, Alias J.; Reiner, David S.; Romijn, Edwin P.; Wong, Catherine C. L.; Davids, Barbara J.; Shah, Sheila A.; Yates, John R.; Gillin, Frances D.

2015-01-01

Giardia lamblia is a flagellated protozoan parasite and a major cause of diarrhea in humans. Its microtubular cytoskeleton mediates trophozoite motility, attachment and cytokinesis, and is characterized by an attachment disk and eight flagella that are each nucleated in a basal body. To date, only 10 giardial basal body proteins have been identified, including universal signaling proteins that are important for regulating mitosis or differentiation. In this study, we have exploited bioinformatics and proteomic approaches to identify new Giardia basal body proteins and confocal microscopy to confirm their localization in interphase trophozoites. This approach identified 75 homologs of conserved basal body proteins in the genome including 65 not previously known to be associated with Giardia basal bodies. Thirteen proteins were confirmed to co-localize with centrin to the Giardia basal bodies. We also demonstrate that most basal body proteins localize to additional cytoskeletal structures in interphase trophozoites. This might help to explain the roles of the four pairs of flagella and Giardia-specific organelles in motility and differentiation. A deeper understanding of the composition of the Giardia basal bodies will contribute insights into the complex signaling pathways that regulate its unique cytoskeleton and the biological divergence of these conserved organelles. PMID:21723868

Treatment of Giardiasis

PubMed Central

Gardner, Timothy B.; Hill, David R.

2001-01-01

Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine. PMID:11148005

[Diarrhea from the infectologist's point of view].

PubMed

Nemes, Zsuzsanna

2009-02-22

Gastroenteritis is a nonspecific term for various pathologic states of the gastrointestinal tract. Gastroenteritis causing pathogens are the second leading cause of morbidity and mortality worldwide. In the developed countries diarrhea is the most common reason for missing work, while in the developing world, it is a leading cause of death. Internationally, the mortality rate is 5-10 million deaths each year. "Traveller's diarrhea" is a polyetiologic common health problem of international travellers which affects travellers generally for days, but it can result in chronic postinfectious irritable bowel syndrome as well. Infectious agents usually cause acute gastroenteritis either by adherence of the intestinal mucosa, or by mucosal invasion, enterotoxin production, and/or cytotoxin production. The incubation period can often suggest the cause of etiology. When symptoms occur within 6 hours of eating, ingestion of preformed toxin of S. aureus or Bacillus cereus should be suspected. The incidence of hypervirulent C. difficile associated colitis is an emerging problem as a healthcare system associated infection. While infectious agents do not commonly cause chronic diarrhea, those that do include C. difficile, Giardia lamblia, Entamoeba histolytica, Cryptosporidium, Aeromonas and Yersinia . Amoebiasis is the second to malaria as a protozoal cause of death. Infection with HIV is also a common cause of diarrhea.

Bioconjugated fluorescent silica nanoparticles for the rapid detection of Entamoeba histolytica.

PubMed

Hemadi, Ahmad; Ekrami, Alireza; Oormazdi, Hormozd; Meamar, Ahmad Reza; Akhlaghi, Lame; Samarbaf-Zadeh, Ali Reza; Razmjou, Elham

2015-05-01

Rapid detection of Entamoeba histolytica based on fluorescent silica nanoparticle (FSNP) indirect immunofluorescence microscopy was evaluated. Silica nanoparticles were synthesized using Stöber's method, with their surface activated to covalently bind to, and immobilize, protein A. For biolabeling, FSNP was added to conjugated E. histolytica trophozoites with monoclonal anti-E. histolytica IgG1 for microscopic observation of fluorescence. Fluorescent silica nanoparticle sensitivity was determined with axenically cultured E. histolytica serially diluted to seven concentrations. Specificity was evaluated using other intestinal protozoa. Fluorescent silica nanoparticles detected E. histolytica at the lowest tested concentration with no cross-reaction with Entamoeba dispar, Entamoeba moshkovskii, Blastocystis sp., or Giardia lamblia. Visualization of E. histolytica trophozoites with anti-E. histolytica antibody labeled with fluorescein isothiocyanate (FITC) was compared with that using anti-E. histolytica antibody bioconjugated FSNP. Although FITC and FSNP produced similar results, the amount of specific antibody required for FITC to induce fluorescence of similar intensity was fivefold that for FSNP. Fluorescent silica nanoparticles delivered a rapid, simple, cost-effective, and highly sensitive and specific method of detecting E. histolytica. Further study is needed before introducing FSNP for laboratory diagnosis of amoebiasis. Copyright © 2015 Elsevier B.V. All rights reserved.

[Detection of Entamoeba histolytica and Entamoeba dispar by PCR in children, less than five years of age with diarrhea, in Maracaibo, Venezuela. A preliminary study].

PubMed

Bracho Mora, Angela; Rivero de Rodríguez, Zulbey; Arraiz, Nailet; Villalobos, Rafael; Urdaneta, Haydee

2013-12-01

To determine the prevalence of Entamoeba histolytica as a producer of diarrhea, a study was conducted in children, less than five years of age, with diarrhea who attended several out patient clinics of the Servicio Aut6nomo Hospital Universitario, Maracaibo, Venezuela. A macroscopic and microscopic examination with physiological saline, lugol and Kinyoun staining were performed to the stool samples obtained. The remainder of the sample was frozen until DNA extraction, and PCR amplification was performed separately for E. histolytica and E. dispar. Microscopic examination showed no trophozoites and/or cysts of Entamoeba histolytica/dispar/moshkovskii, or intestinal coccidians in any of the 50 samples analyzed. Parasites detected were Giardia lamblia (6%), Blastocystis sp. (4%), Pentatrichomonas hominis (2%), Ascaris lumbricoides (2%) and Trichuris trichiura (2%). By PCR, six samples (12%) had DNA of E. dispar and two (4%) had DNA from E. histolytica; no child showed association of both amoebae. The two children who had E. histolytica were one-year-old. E. dispar was detected in younger children. We suggest that the prevalence of E. histolytica in children under five years is really low.

Evaluation of a new single-tube multiprobe real-time PCR for diagnosis of Entamoeba histolytica and Entamoeba dispar.

PubMed

Liang, Shih-Yu; Hsia, Kan-Tai; Chan, Yun-Hsien; Fan, Chia-Kwung; Jiang, Donald Dah-Shyong; Landt, Olfert; Ji, Dar-Der

2010-08-01

A single-tube multiprobe real-time PCR assay for simultaneous detection of Entamoeba histolytica and Entamoeba dispar was developed. One primer pair with 2 species-specific probes was designed based on new SSU RNA regions of the ribosomal DNA-containing episome. The sensitivity is 1 parasite per milliliter of feces and thus superior to the conventional nested PCR and comparable to other published real-time PCR protocols. The applicability for clinical diagnosis was validated with 218 stool specimens from patients. A total of 51 E. histolytica and 39 E. dispar positive samples was detected by the multiprobe real-time PCR compared to 39 and 22 by routine nested PCR diagnosis. The detection rate of Entamoeba species for the multiprobe real-time PCR assays was significantly higher than the nested PCR (40.8% vs. 28.0%, P < 0.01). The test did not show cross reactivity with DNA from Entamoeba moshkovskii, Giardia lamblia , Cryptosporidium sp., Escherichia coli , or other nonpathogenic enteric parasites. The multiprobe real-time PCR assay is simple and rapid and has high specificity and sensitivity. The assay could streamline the laboratory diagnosis procedure and facilitate epidemiological investigation.

Host defences against Giardia lamblia.

PubMed

Lopez-Romero, G; Quintero, J; Astiazarán-García, H; Velazquez, C

2015-08-01

Giardia spp. is a protozoan parasite that inhabits the upper small intestine of mammals and other species and is the aetiological agent of giardiasis. It has been demonstrated that nitric oxide, mast cells and dendritic cells are the first line of defence against Giardia. IL-6 and IL-17 play an important role during infection. Several cytokines possess overlapping functions in regulating innate and adaptive immune responses. IgA and CD4(+) T cells are fundamental to the process of Giardia clearance. It has been suggested that CD4(+) T cells play a double role during the anti-Giardia immune response. First, they activate and stimulate the differentiation of B cells to generate Giardia-specific antibodies. Second, they act through a B-cell-independent mechanism that is probably mediated by Th17 cells. Several Giardia proteins that stimulate humoral and cellular immune responses have been described. Variant surface proteins, α-1 giardin, and cyst wall protein 2 can induce host protective responses to future Giardia challenges. The characterization and evaluation of the protective potential of the immunogenic proteins that are associated with Giardia will offer new insights into host-parasite interactions and may aid in the development of an effective vaccine against the parasite. © 2015 John Wiley & Sons Ltd.

[Prevalence of iron and iodine deficiency, and parasitosis among children from Arandas, Jalisco, Mexico].

PubMed

Vásquez-Garibay, Edgar Manuel; Romero-Velarde, Enrique; Nápoles-Rodríguez, Francisco; Nuño-Cosío, María Eugenia; Trujillo-Contreras, Francisco; Sánchez-Mercado, Oscar

2002-01-01

To estimate the prevalence of iron deficiency, iodine deficiency and parasitosis in children attending the Instituto Alteño para el Desarrollo de Jalisco (Highlands Institute for Development of Jalisco State, INADEJ), Arandas, Jalisco, Mexico. A cross-sectional study was conducted between 1997 and 1999, among 432 children aged 12 to 120 months attending the INADEJ. Measurements included hematological values, urine iodine concentration, and presence of parasites. Student's t test chi square tests were used for parametric and nonparametric analysis. The prevalence figures of anemia (20 vs 7.4%, p = 0.007) and iron deficiency (60.9 vs 44.4%, p = 0.02) were higher in preschool than in school children. Iodine deficiency was found in 29% (10.5% moderate or severe) and parasitosis in 47.2% of children, mainly E. histolytica (30.2%) and G. lamblia (28.9%). Low income, male gender and lack of social security policy holding were associated to parasitosis. The high prevalence rates of iron deficiency, iodine deficiency, and parasitosis, should be addressed by state health services with effective interventions to restrain these preventable diseases. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Detection of Pathogenic Protozoa in the Diagnostic Laboratory: Result Reproducibility, Specimen Pooling, and Competency Assessment▿

PubMed Central

Libman, M. D.; Gyorkos, T. W.; Kokoskin, E.; MacLean, J. D.

2008-01-01

Stool microscopy as performed in clinical parasitology laboratories is a complex procedure with subjective interpretation. Quality assurance (QA) programs often emphasize proficiency testing as an assessment tool. We describe a result reproducibility assessment tool, which can form part of a broader QA program, and which is based on the blinded resubmission of selected clinical samples, using concordance between the reports of the initial and resubmitted specimen as an indicator. Specimens preserved in sodium acetate-acetic acid-formalin can be stored for several months for use in such a program. The presence of multiple protozoa in one specimen does not affect concordance. Some dilution of specimens occurs in this process, and this may explain poor concordance when specimens with low protozoal concentrations are resubmitted. Evaluation of this tool in a large parasitology laboratory revealed concordance rates for pathogenic protozoa (Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Dientamoeba fragilis) of about 80%, which may be considered for use as a benchmark value. We also used this tool to demonstrate that when pairs of specimens from one patient are pooled to create a single specimen, concordance between the results of the individual and pooled specimens is high. PMID:18448690

Molecular typing of canine Giardia duodenalis isolates from Minas Gerais, Brazil.

PubMed

Fava, Natália M N; Soares, Rodrigo M; Scalia, Luana A M; Cunha, Maria Júlia Rodrigues da; Faria, Elaine S M; Cury, Márcia Cristina

2016-02-01

Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia) is a widespread intestinal parasite in mammals, including humans and pets worldwide. It should be considered a species complex and comprises eight assemblage (A-H). This works aimed to determine the genotypic variability among G. duodenalis isolates from dogs from Minas Gerais state, Brazil. Fecal samples of 97 dogs, from 1-to-10 months old from 15 commercial kennels, were collected and analyzed by the zinc sulfate centrifugal flotation technique, to determine their positivity for G. duodenalis cysts. Cysts pellets were stored and submitted to PCR and nested-PCR reactions with gdh and tpi primers, and then sequencing. Among positive samples (n = 19), fragment amplifications of gdh and tpi genes was observed in 16 (84,2%) and 14 (73,6%), respectively. In total, 30 sequences were obtained. Sequencing analysis showed that for gdh, all isolates were identified as host-specific genotype D, and for tpi, besides host-specific genotype C, were also observed zoonotic genotypes A and B. This study provides, for the first time, current information about genetic characterization of G. duodenalis isolates found in dogs in Minas Gerais state. Copyright © 2016 Elsevier Inc. All rights reserved.

Anorexia, bulimia, and the female athlete triad: evaluation and management.

PubMed

Mendelsohn, Felicia A; Warren, Michelle P

2010-03-01

The female athlete triad is an increasingly prevalent condition involving disordered eating, amenorrhea, and osteoporosis. An athlete can suffer from all 3 components of the triad, or just 1 or 2 of the individual conditions. The main element underlying all the aspects of the triad is an adaptation to a negative caloric balance. Screening for these disorders should be an important component of an athlete's care. Prevention and treatment should involve a team approach, including a physician, a nutritionist, and a mental health provider. Copyright 2010 Elsevier Inc. All rights reserved.

Proving Correctness for Pointer Programs in a Verifying Compiler

NASA Technical Reports Server (NTRS)

Kulczycki, Gregory; Singh, Amrinder

2008-01-01

This research describes a component-based approach to proving the correctness of programs involving pointer behavior. The approach supports modular reasoning and is designed to be used within the larger context of a verifying compiler. The approach consists of two parts. When a system component requires the direct manipulation of pointer operations in its implementation, we implement it using a built-in component specifically designed to capture the functional and performance behavior of pointers. When a system component requires pointer behavior via a linked data structure, we ensure that the complexities of the pointer operations are encapsulated within the data structure and are hidden to the client component. In this way, programs that rely on pointers can be verified modularly, without requiring special rules for pointers. The ultimate objective of a verifying compiler is to prove-with as little human intervention as possible-that proposed program code is correct with respect to a full behavioral specification. Full verification for software is especially important for an agency like NASA that is routinely involved in the development of mission critical systems.

Holistic processing of face configurations and components.

PubMed

Hayward, William G; Crookes, Kate; Chu, Ming Hon; Favelle, Simone K; Rhodes, Gillian

2016-10-01

Although many researchers agree that faces are processed holistically, we know relatively little about what information holistic processing captures from a face. Most studies that assess the nature of holistic processing do so with changes to the face affecting many different aspects of face information (e.g., different identities). Does holistic processing affect every aspect of a face? We used the composite task, a common means of examining the strength of holistic processing, with participants making same-different judgments about configuration changes or component changes to 1 portion of a face. Configuration changes involved changes in spatial position of the eyes, whereas component changes involved lightening or darkening the eyebrows. Composites were either aligned or misaligned, and were presented either upright or inverted. Both configuration judgments and component judgments showed evidence of holistic processing, and in both cases it was strongest for upright face composites. These results suggest that holistic processing captures a broad range of information about the face, including both configuration-based and component-based information. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Genome-scale analysis of the high-efficient protein secretion system of Aspergillus oryzae

PubMed Central

2014-01-01

Background The koji mold, Aspergillus oryzae is widely used for the production of industrial enzymes due to its particularly high protein secretion capacity and ability to perform post-translational modifications. However, systemic analysis of its secretion system is lacking, generally due to the poorly annotated proteome. Results Here we defined a functional protein secretory component list of A. oryzae using a previously reported secretory model of S. cerevisiae as scaffold. Additional secretory components were obtained by blast search with the functional components reported in other closely related fungal species such as Aspergillus nidulans and Aspergillus niger. To evaluate the defined component list, we performed transcriptome analysis on three α-amylase over-producing strains with varying levels of secretion capacities. Specifically, secretory components involved in the ER-associated processes (including components involved in the regulation of transport between ER and Golgi) were significantly up-regulated, with many of them never been identified for A. oryzae before. Furthermore, we defined a complete list of the putative A. oryzae secretome and monitored how it was affected by overproducing amylase. Conclusion In combination with the transcriptome data, the most complete secretory component list and the putative secretome, we improved the systemic understanding of the secretory machinery of A. oryzae in response to high levels of protein secretion. The roles of many newly predicted secretory components were experimentally validated and the enriched component list provides a better platform for driving more mechanistic studies of the protein secretory pathway in this industrially important fungus. PMID:24961398

Genome-scale analysis of the high-efficient protein secretion system of Aspergillus oryzae.

PubMed

Liu, Lifang; Feizi, Amir; Österlund, Tobias; Hjort, Carsten; Nielsen, Jens

2014-06-24

The koji mold, Aspergillus oryzae is widely used for the production of industrial enzymes due to its particularly high protein secretion capacity and ability to perform post-translational modifications. However, systemic analysis of its secretion system is lacking, generally due to the poorly annotated proteome. Here we defined a functional protein secretory component list of A. oryzae using a previously reported secretory model of S. cerevisiae as scaffold. Additional secretory components were obtained by blast search with the functional components reported in other closely related fungal species such as Aspergillus nidulans and Aspergillus niger. To evaluate the defined component list, we performed transcriptome analysis on three α-amylase over-producing strains with varying levels of secretion capacities. Specifically, secretory components involved in the ER-associated processes (including components involved in the regulation of transport between ER and Golgi) were significantly up-regulated, with many of them never been identified for A. oryzae before. Furthermore, we defined a complete list of the putative A. oryzae secretome and monitored how it was affected by overproducing amylase. In combination with the transcriptome data, the most complete secretory component list and the putative secretome, we improved the systemic understanding of the secretory machinery of A. oryzae in response to high levels of protein secretion. The roles of many newly predicted secretory components were experimentally validated and the enriched component list provides a better platform for driving more mechanistic studies of the protein secretory pathway in this industrially important fungus.

Non-destructive component separation using infrared radiant energy

DOEpatents

Simandl, Ronald F [Knoxville, TN; Russell, Steven W [Knoxville, TN; Holt, Jerrid S [Knoxville, TN; Brown, John D [Harriman, TN

2011-03-01

A method for separating a first component and a second component from one another at an adhesive bond interface between the first component and second component. Typically the method involves irradiating the first component with infrared radiation from a source that radiates substantially only short wavelengths until the adhesive bond is destabilized, and then separating the first component and the second component from one another. In some embodiments an assembly of components to be debonded is placed inside an enclosure and the assembly is illuminated from an IR source that is external to the enclosure. In some embodiments an assembly of components to be debonded is simultaneously irradiated by a multi-planar array of IR sources. Often the IR radiation is unidirectional. In some embodiments the IR radiation is narrow-band short wavelength infrared radiation.

EVALUATION OF ACID DEPOSITION MODELS USING PRINCIPAL COMPONENT SPACES

EPA Science Inventory

An analytical technique involving principal components analysis is proposed for use in the evaluation of acid deposition models. elationships among model predictions are compared to those among measured data, rather than the more common one-to-one comparison of predictions to mea...

TOGA: A TOUGH code for modeling three-phase, multi-component, and non-isothermal processes involved in CO 2-based Enhanced Oil Recovery

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

Pan, Lehua; Oldenburg, Curtis M.

TOGA is a numerical reservoir simulator for modeling non-isothermal flow and transport of water, CO 2, multicomponent oil, and related gas components for applications including CO 2-enhanced oil recovery (CO 2-EOR) and geologic carbon sequestration in depleted oil and gas reservoirs. TOGA uses an approach based on the Peng-Robinson equation of state (PR-EOS) to calculate the thermophysical properties of the gas and oil phases including the gas/oil components dissolved in the aqueous phase, and uses a mixing model to estimate the thermophysical properties of the aqueous phase. The phase behavior (e.g., occurrence and disappearance of the three phases, gas +more » oil + aqueous) and the partitioning of non-aqueous components (e.g., CO 2, CH 4, and n-oil components) between coexisting phases are modeled using K-values derived from assumptions of equal-fugacity that have been demonstrated to be very accurate as shown by comparison to measured data. Models for saturated (water) vapor pressure and water solubility (in the oil phase) are used to calculate the partitioning of the water (H 2O) component between the gas and oil phases. All components (e.g., CO 2, H 2O, and n hydrocarbon components) are allowed to be present in all phases (aqueous, gaseous, and oil). TOGA uses a multiphase version of Darcy’s Law to model flow and transport through porous media of mixtures with up to three phases over a range of pressures and temperatures appropriate to hydrocarbon recovery and geologic carbon sequestration systems. Transport of the gaseous and dissolved components is by advection and Fickian molecular diffusion. New methods for phase partitioning and thermophysical property modeling in TOGA have been validated against experimental data published in the literature for describing phase partitioning and phase behavior. Flow and transport has been verified by testing against related TOUGH2 EOS modules and CMG. The code has also been validated against a CO 2-EOR experimental core flood involving flow of three phases and 12 components. Results of simulations of a hypothetical 3D CO 2-EOR problem involving three phases and multiple components are presented to demonstrate the field-scale capabilities of the new code. This user guide provides instructions for use and sample problems for verification and demonstration.« less

Robustness of Flexible Systems With Component-Level Uncertainties

NASA Technical Reports Server (NTRS)

Maghami, Peiman G.

2000-01-01

Robustness of flexible systems in the presence of model uncertainties at the component level is considered. Specifically, an approach for formulating robustness of flexible systems in the presence of frequency and damping uncertainties at the component level is presented. The synthesis of the components is based on a modifications of a controls-based algorithm for component mode synthesis. The formulation deals first with robustness of synthesized flexible systems. It is then extended to deal with global (non-synthesized ) dynamic models with component-level uncertainties by projecting uncertainties from component levels to system level. A numerical example involving a two-dimensional simulated docking problem is worked out to demonstrate the feasibility of the proposed approach.

Street conflict mediation to prevent youth violence: conflict characteristics and outcomes.

PubMed

Whitehill, Jennifer M; Webster, Daniel W; Vernick, Jon S

2013-06-01

Mediation of potentially violent conflicts is a key component of CeaseFire, an effective gun violence-prevention programme. To describe conflicts mediated by outreach workers (OW) in Baltimore's CeaseFire replication, examine neighbourhood variation, and measure associations between conflict risk factors and successful nonviolent resolution. A cross-sectional study was conducted using records for 158 conflicts mediated between 2007 and 2009. Involvement of youth, gangs, retaliation, weapons and other risk factors were described. Principal component analysis (PCA) was used for data-reduction purposes before the relationship between conflict risk components and mediation success was assessed with multivariate logistic regression. Most conflicts involved 2-3 individuals. Youth, persons with a history of violence, gang members and weapons were commonly present. OWs reported immediate, nonviolent resolution for 65% of mediated conflicts; an additional 23% were at least temporarily resolved without violence. PCA identified four dimensions of conflict risk: the risk-level of individuals involved; whether the incident was related to retaliation; the number of people involved; and shooting likelihood. However, these factors were not related to the OW's ability to resolve the conflict. Neighbourhoods with programme-associated reductions in homicides mediated more gang-related conflicts; neighbourhoods without programme-related homicide reductions encountered more retaliatory conflicts and more weapons.

Health inequities: lower socio-economic conditions and higher incidences of intestinal parasites

PubMed Central

Östan, İpek; Kilimcioğlu, Ali A; Girginkardeşler, Nogay; Özyurt, Beyhan C; Limoncu, M Emin; Ok, Ülgen Z

2007-01-01

Background Intestinal parasitic infections affect child health and development and slow down growth, while reducing adults' productivity and work capacity. The aim of the present study was to determine and compare the incidences of intestinal parasitic infections and the socio-economic status of two near primary school children in Manisa, a western city of Turkey. Methods A total of 352 children were involved a questionnaire study from a private school (Ülkem Primary School – ÜPS, 116 children) and a community-based school (Şehzadeler Primary School – ŞPS, 236 children). Of these, stool samples could be obtained from a total of 294 students; 97 (83.6%) from ÜPS, and 197 (83.5%) from ŞPS. The wet mount preparations of the stool samples were examined; samples were also fixed in polyvinyl alcohol and examined with modified formalin ethyl acetate sedimentation and trichrome staining techniques. Data were analyzed using SPSS for Windows version 10.0. The chi-squared test was used for the analytic assessment. Results The percentages of the students found to be infected with intestinal parasites, were 78 (39.6%) and 13 (13.4%) in ŞPS and ÜPS, respectively. Totally 91 (31.0%) of the students from both schools were found to be infected with at least one intestinal parasite. Giardia lamblia was found to be the most common pathogenic intestinal parasite and Blastocystis hominis was prevalent independently from the hygienic conditions. The factors which significantly (p < 0.05) increase the incidence of intestinal parasites were uneducated and unemployed mother, lower social status of father, living in crowded houses with insufficient indoor spaces, using the tap water as drinking water, and living at shanty areas. Conclusion Intestinal parasitic infections in school children were found to be a public health problem that increased due to lower socio-economic conditions. We conclude that organization of education seminars including the topics such as prevention of the infectious diseases, improving general hygienic conditions, and application of supportive programs for the parents may be suggested not only to reduce intestinal parasitic infections, but also to elevate the socio-cultural levels. PMID:18042287

[Neural and cognitive correlates of social cognition: findings on neuropsychological and neuroimaging studies].

PubMed

Kobayakawa, Mutsutaka; Kawamura, Mitsuru

2011-12-01

Social cognition includes various components of information processing related to communication with other individuals. In this review, we have discussed 3 components of social cognitive function: face recognition, empathy, and decision making. Our social behavior involves recognition based on facial features and also involves empathizing with others; while making decisions, it is important to consider the social consequences of the course of action followed. Face recognition is divided into 2 routes for information processing: a route responsible for overt recognition of the face's identity and a route for emotional and orienting responses based on the face's personal affective significance. Two systems are possibly involved in empathy: a basic emotional contagion "mirroring" system and a more advanced "theory of mind" system that considers the cognitive perspective. Decision making is mediated by a widespread system that includes several cortical and subcortical components. Numerous lesion and neuroimaging studies have contributed to clarifying the neural correlates of social cognitive function, and greater information can be obtained on social cognitive function by combining these 2 approaches.

10 CFR 34.101 - Notifications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... written report to the NRC's Office of Federal and State Materials and Environmental Management Programs... shielded position and secure it in this position; or (3) Failure of any component (critical to safe... overexposure submitted under 10 CFR 20.2203 which involves failure of safety components of radiography...

QUANTITATION OF MOLECULAR ENDPOINTS FOR THE DOSE-RESPONSE COMPONENT OF CANCER RISK ASSESSMENT

EPA Science Inventory

Cancer risk assessment involves the steps of hazard identification, dose-response assessment, exposure assessment and risk characterization. The rapid advances in the use of molecular biology approaches has had an impact on all four components, but the greatest overall current...

Reaching a Consensus on the Definition of Genetic Literacy that Is Required from a Twenty-First-Century Citizen

NASA Astrophysics Data System (ADS)

Boerwinkel, Dirk Jan; Yarden, Anat; Waarlo, Arend Jan

2017-12-01

To determine what knowledge of genetics is needed for decision-making on genetic-related issues, a consensus-reaching approach was used. An international group of 57 experts, involved in teaching, studying, or developing genetic education and communication or working with genetic applications in medicine, agriculture, or forensics, answered the questions: "What knowledge of genetics is relevant to those individuals not professionally involved in science?" and "Why is this knowledge relevant?" The answers were classified in different knowledge components following the PISA 2015 science framework. During a workshop with the participants, the results were discussed and applied to seven cases in which genetic knowledge is relevant for decision-making. The analysis of these discussions resulted in a revised framework consisting of nine conceptual knowledge components, three sociocultural components, and four epistemic components. The framework can be used in curricular decisions; its open character allows for including new technologies and applications and facilitates comparisons of different cases.

Design and development of progressive tool for manufacturing washer

NASA Astrophysics Data System (ADS)

Annigeri, Ulhas K.; Raghavendra Ravi Kiran, K.; Deepthi, Y. P.

2017-07-01

In a progressive tool the raw material is worked at different station to finally fabricate the component. A progressive tool is a lucrative tool for mass production of components. A lot of automobile and other transport industries develop progressive tool for the production of components. The design of tool involves lot of planning and the same amount of skill of process planning is required in the fabrication of the tool. The design also involves use of thumb rules and standard elements as per experience gained in practice. Manufacturing the press tool is a laborious task as special jigs and fixtures have to be designed for the purpose. Assembly of all the press tool elements is another task where use of accurate measuring instruments for alignment of various tool elements is important. In the present study, design and fabrication of progressive press tool for production of washer has been developed and the press tool has been tried out on a mechanical type of press. The components produced are to dimensions.

A comparison of the hazard perception ability of accident-involved and accident-free motorcycle riders.

PubMed

Cheng, Andy S K; Ng, Terry C K; Lee, Hoe C

2011-07-01

Hazard perception is the ability to read the road and is closely related to involvement in traffic accidents. It consists of both cognitive and behavioral components. Within the cognitive component, visual attention is an important function of driving whereas driving behavior, which represents the behavioral component, can affect the hazard perception of the driver. Motorcycle riders are the most vulnerable types of road user. The primary purpose of this study was to deepen our understanding of the correlation of different subtypes of visual attention and driving violation behaviors and their effect on hazard perception between accident-free and accident-involved motorcycle riders. Sixty-three accident-free and 46 accident-involved motorcycle riders undertook four neuropsychological tests of attention (Digit Vigilance Test, Color Trails Test-1, Color Trails Test-2, and Symbol Digit Modalities Test), filled out the Chinese Motorcycle Rider Driving Violation (CMRDV) Questionnaire, and viewed a road-user-based hazard situation with an eye-tracking system to record the response latencies to potentially dangerous traffic situations. The results showed that both the divided and selective attention of accident-involved motorcycle riders were significantly inferior to those of accident-free motorcycle riders, and that accident-involved riders exhibited significantly higher driving violation behaviors and took longer to identify hazardous situations compared to their accident-free counterparts. However, the results of the regression analysis showed that aggressive driving violation CMRDV score significantly predicted hazard perception and accident involvement of motorcycle riders. Given that all participants were mature and experienced motorcycle riders, the most plausible explanation for the differences between them is their driving style (influenced by an undesirable driving attitude), rather than skill deficits per se. The present study points to the importance of conceptualizing the influence of different driving behaviors so as to enrich our understanding of the role of human factors in road accidents and consequently develop effective countermeasures to prevent traffic accidents involving motorcycles. Copyright © 2011 Elsevier Ltd. All rights reserved.

Human factors analysis of workstation design: Earth Radiation Budget Satellite Mission Operations Room

NASA Technical Reports Server (NTRS)

Stewart, L. J.; Murphy, E. D.; Mitchell, C. M.

1982-01-01

A human factors analysis addressed three related yet distinct issues within the area of workstation design for the Earth Radiation Budget Satellite (ERBS) mission operation room (MOR). The first issue, physical layout of the MOR, received the most intensive effort. It involved the positioning of clusters of equipment within the physical dimensions of the ERBS MOR. The second issue for analysis was comprised of several environmental concerns, such as lighting, furniture, and heating and ventilation systems. The third issue was component arrangement, involving the physical arrangement of individual components within clusters of consoles, e.g., a communications panel.

The economics of project analysis: Optimal investment criteria and methods of study

NASA Technical Reports Server (NTRS)

Scriven, M. C.

1979-01-01

Insight is provided toward the development of an optimal program for investment analysis of project proposals offering commercial potential and its components. This involves a critique of economic investment criteria viewed in relation to requirements of engineering economy analysis. An outline for a systems approach to project analysis is given Application of the Leontief input-output methodology to analysis of projects involving multiple processes and products is investigated. Effective application of elements of neoclassical economic theory to investment analysis of project components is demonstrated. Patterns of both static and dynamic activity levels are incorporated.

Weak Interactions

DOE R&D Accomplishments Database

Lee, T. D.

1957-06-01

Experimental results on the non-conservation of parity and charge conservation in weak interactions are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi interactions are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)

Dynamics of Alliances.

ERIC Educational Resources Information Center

Hubbard, James; And Others

To encourage the involvement of the community in mathematics, science, and technology education, some states and localities have formed alliances. This book outlines four key components of alliance building: process, environment, structure, and outcomes; and describes how changes in one component affect the others. It is designed to serve as a…

Memory Perceptions and Memory Performance in Adulthood and Aging.

ERIC Educational Resources Information Center

Hultsch, D. F.; And Others

1985-01-01

This article reviews two questionnaires designed to measure people's perceptions of their own memories and identifies several research questions requiring further study. Results show that, in general, memory perceptions appear to be multidimensional and involve belief and affective components as well as knowledge components. (CT)

Preventing Food Allergies by Tricking Dendritic Cells

USDA-ARS?s Scientific Manuscript database

Food allergies are adverse responses to components (usually proteins) within the foods we eat, which result in a self-damaging response from our immune system. A myriad of cellular and molecular components are involved in the decision to tolerate or respond to foreign molecules that pass through the...

Acadia National Park ITS field operational test : key informant interviews

DOT National Transportation Integrated Search

2003-03-01

This document reflects the ideas and opinions of a group of key informants and stakeholders involved in the Field Operational Test of ITS components in and around Acadia National Park from 1999 through 2002. The stakeholders were involved in the plan...

Individualized Education Programs for Students with Autism: Including Parents in the Process.

ERIC Educational Resources Information Center

Simpson, Richard L.

1995-01-01

The involvement of parents in developing individualized education programs (IEPs) for their children with autism is discussed. Essential components of IEP documents are outlined, and strategies that professionals can use to promote significant family involvement are considered. (Author/SW)

Strategies in Development and Delivery of Nanotechnology Based Cosmetic Products.

PubMed

Ahmad, Usama; Ahmad, Zeeshan; Khan, Ahmed Abdullah; Akhtar, Juber; Singh, Satya Prakash; Ahmad, Farhan Jalees

2018-03-26

The science of formulation involving cosmetic ingredients has always been a challenge since the release of active components greatly depends upon the carrier system involved and the selectivity of skin barrier. The principle obstacle of the skin resides in the epidermis and it's hard for many active components to cross it. The formulation related factors like size of particles, viscosity and lipophilicity of the components also play an important role in permeation of the dermal composition. Though widely used; conventional creams and gels still struggle in terms of success. This work focuses on nano based formulation strategies for successful delivery of cosmetic agents. Novel strategies like nanoemulsion, nanogels, liposomes, aquasomes, niosomes, dendrimers and fullerenes have paved way for successful delivery of dermal formulations to desire depths in the skin. © Georg Thieme Verlag KG Stuttgart · New York.

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers

PubMed Central

Yon, Felipe; Joo, Youngsung; Cortés Llorca, Lucas; Rothe, Eva; Baldwin, Ian T.; Kim, Sang-Gyu

2016-01-01

Summary The rhythmic opening/closing and volatile emissions of flowers is known to attract pollinators at specific times. That these rhythms are maintained under constant light or dark conditions suggests a circadian clock involvement. Although a forward and reverse genetic approach led to the identification of core circadian clock components in Arabidopsis thaliana, involvement of these clock components for floral rhythms remained untested likely due to weak diurnal rhythms in A. thaliana flowers.Here we addressed the role of these core clock components in the flowers of the wild tobacco Nicotiana attenuata, whose flowers open at night, emit benzyl acetone (BA) scents, and move vertically through a 140° arc.We first measured N. attenuata floral rhythms under constant light conditions. The results suggest that the circadian clock controls flower opening, BA emission, and pedicel movement, but not flower closing.We generated transgenic N. attenuata lines silenced in the homologous genes of Arabidopsis LATE ELONGATED HYPOCOTYL (LHY) and ZEITLUPE (ZTL), which are known as a core clock component. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. PMID:26439540

Investigating Mitochondrial Dysfunction in Human Lung Cells Exposed to Redox-Active PM Components

EPA Science Inventory

Exposure to ambient particulate matter (PM) causes cardiopulmonary morbidity and mortality through mechanisms that involve oxidative stress. 1,2-naphthoquinone (1,2-NQ) is a ubiquitous component of PM and a potent redox-active electrophile. We previously reported that 1,2-NQ incr...

Final Evaluation Report. 1976-1977. Title I Migrant Program. Publication Number: 76.59.

ERIC Educational Resources Information Center

Austin Independent School District, TX. Office of Research and Evaluation.

The final evaluation of the Elementary and Secondary Education Act Title I Migrant Program in the Austin, Texas Independent School District is reported. The program consisted of instructional, student recruitment, parental involvement, health services, and clothing components. The instructional component included programs for pre-kindergarten…

Evaluation of the Fredonia Outreach Program.

ERIC Educational Resources Information Center

Mohan, Madan; And Others

Purpose of the program was to provide each migrant child the educational treatment that would be most effective in developing his potential. Consisting of a reading component which provided remedial reading instruction using tutors, and the LEAD (Learn, Experience, and Develop) component which involved parents and the community in bringing about…

Application of molecular genetic tools for forest pathology

Treesearch

Mee-Sook Kim; John Hanna; Amy Ross-Davis; Ned Klopfenstein

2012-01-01

In recent years, advances in molecular genetics have provided powerful tools to address critical issues in forest pathology to help promote resilient forests. Although molecular genetic tools are initially applied to understand individual components of forest pathosystems, forest pathosystems involve dynamic interactions among biotic and abiotic components of the...

Accelerated Reader/Reading Renaissance. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2007

2007-01-01

The Accelerated Reader/Reading Renaissance program (now called Accelerated Reader Best Classroom Practices) is a guided reading intervention in which teachers direct student reading of text. It involves two components. Reading Renaissance, the first component, is a set of recommended principles on guided reading (or teachers' direction of…

[Pain in humans: experimental facts and hypotheses].

PubMed

Cesaro, P

1994-09-15

The description of painful phenomena in humans has to take into account its different components: sensory component (relevant to nociception), affective and emotional components. Nociceptor's (physiology is best understood with electrophysiological and neurochemical methods allowing a clear description of hyperalgesia, with its peripheral and spinal mechanisms. A functional model is partly available to explain allodynia, spontaneous burning pain and lightning pain, the three main consequences following deafferentation. At the thalamo-cortical level, one can describe nociceptive pathways and other pathways or neuronal networks involved in the affective and emotional components of pain.

Correction to hill (2005).

PubMed

Hill, Clara E

2006-01-01

Reports an error in "Therapist Techniques, Client Involvement, and the Therapeutic Relationship: Inextricably Intertwined in the Therapy Process" by Clara E. Hill (Psychotherapy: Theory, Research, Practice, Training, 2005 Win, Vol 42(4), 431-442). An author's name was incorrectly spelled in a reference. The correct reference is presented. (The following abstract of the original article appeared in record 2006-03309-003.) I propose that therapist techniques, client involvement, and the therapeutic relationship are inextricably intertwined and need to be considered together in any discussion of the therapy process. Furthermore, I present a pantheoretical model of how these three variables evolve over four stages of successful therapy: initial impression formation, beginning the therapy (involves the components of facilitating client exploration and developing case conceptualization and treatment strategies), the core work of therapy (involves the components of theory-relevant tasks and overcoming obstacles), and termination. Theoretical propositions as well as implications for training and research are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Potyvirus helper component-proteinase self-interaction in the yeast two-hybrid system and delineation of the interaction domain involved.

PubMed

Urcuqui-Inchima, S; Walter, J; Drugeon, G; German-Retana, S; Haenni, A L; Candresse, T; Bernardi, F; Le Gall, O

1999-05-25

Using the yeast two-hybrid system, a screen was performed for possible interactions between the proteins encoded by the 5' region of potyviral genomes [P1, helper component-proteinase (HC-Pro), and P3]. A positive self-interaction involving HC-Pro was detected with lettuce mosaic virus (LMV) and potato virus Y (PVY). The possibility of heterologous interaction between the HC-Pro of LMV and of PVY was also demonstrated. No interaction involving either the P1 or the P3 proteins was detected. A series of ordered deletions from either the N- or C-terminal end of the LMV HC-Pro was used to map the domain involved in interaction to the 72 N-terminal amino acids of the protein, a region known to be dispensable for virus viability but necessary for aphid transmission. A similar but less detailed analysis mapped the interacting domain to the N-terminal half of the PVY HC-Pro. Copyright 1999 Academic Press.

Mental Imagery and Post-Traumatic Stress Disorder: A Neuroimaging and Experimental Psychopathology Approach to Intrusive Memories of Trauma

PubMed Central

Clark, Ian A.; Mackay, Clare E.

2015-01-01

This hypothesis and theory paper presents a pragmatic framework to help bridge the clinical presentation and neuroscience of intrusive memories following psychological trauma. Intrusive memories are a hallmark symptom of post-traumatic stress disorder (PTSD). However, key questions, including those involving etiology, remain. In particular, we know little about the brain mechanisms involved in why only some moments of the trauma return as intrusive memories while others do not. We first present an overview of the patient experience of intrusive memories and the neuroimaging studies that have investigated intrusive memories in PTSD patients. Next, one mechanism of how to model intrusive memories in the laboratory, the trauma film paradigm, is examined. In particular, we focus on studies combining the trauma film paradigm with neuroimaging. Stemming from the clinical presentation and our current understanding of the processes involved in intrusive memories, we propose a framework in which an intrusive memory comprises five component parts; autobiographical (trauma) memory, involuntary recall, negative emotions, attention hijacking, and mental imagery. Each component part is considered in turn, both behaviorally and from a brain imaging perspective. A mapping of these five components onto our understanding of the brain is described. Unanswered questions that exist in our understanding of intrusive memories are considered using the proposed framework. Overall, we suggest that mental imagery is key to bridging the experience, memory, and intrusive recollection of the traumatic event. Further, we suggest that by considering the brain mechanisms involved in the component parts of an intrusive memory, in particular mental imagery, we may be able to aid the development of a firmer bridge between patients’ experiences of intrusive memories and the clinical neuroscience behind them. PMID:26257660

Power Provision Based on Self-Sacrificing Craft

NASA Technical Reports Server (NTRS)

Hinchey, Michael G. (Inventor); Sterrit, Roy (Inventor); Vassev, Emil I. (Inventor); Hinchey, Bridget (Inventor)

2015-01-01

A biologically-inspired system and method is provided for self-adapting behavior of swarm-based exploration missions, whereby individual components, for example, spacecraft, in the system can sacrifice themselves for the greater good of the entire system. The self-sacrifice can involve donating resources or assets, such as power provisions, to a different component of an autonomous system. A receiving component of the system can benefit from receiving the donated resource or power provision.

Community Involvement Components in Culturally-Oriented Teacher Preparation.

ERIC Educational Resources Information Center

Mahan, James M.

At Indiana University, preservice teachers participate in required community-based multicultural programs that allow them to become directly involved with community characteristics, values, needs, and achievements. It is hoped that this experience will help them to adapt curriculum and instructional techniques to fit community realities and…

Does autophagy take a front seat in lifespan extension?

PubMed Central

Petrovski, Goran; Das, Dipak K

2010-01-01

Abstract This review focuses on the interrelationship between ageing and autophagy. There is a striking similarity between the signalling aspects of these two processes. Both ageing and autophagy involve several of the signalling components such as insulin/IGF-1, AMPK, Ras-cAMP-PKA, Sch9 and mTOR. Ageing and ageing-mediated defective autophagy involve accumulation of lipofuscin. Components of anti-ageing and autophagy include SirTs and FoxOs. Nutritional deprivation or calorie restriction as well as several nutriceuticals including resveratrol, spermidine, curcumin and piperine can enhance autophagy and increase lifespan. Such striking similarities indicate that lifespan is strongly dependent on autophagy. PMID:21114762

Identification of a two-component signal transduction system involved in fimbriation of Porphyromonas gingivalis.

PubMed

Hayashi, J; Nishikawa, K; Hirano, R; Noguchi, T; Yoshimura, F

2000-01-01

Porphyromonas gingivalis, a periodontopathogen, is an oral anaerobic gram-negative bacterium with numerous fimbriae on the cell surface. Fimbriae have been considered to be an important virulence factor in this organism. We analyzed the genomic DNA of transposon-induced, fimbria-deficient mutants derived from ATCC 33277 and found that seven independent mutants had transposon insertions within the same restriction fragment. Cloning and sequencing of the disrupted region from one of the mutants revealed two adjacent open reading frames (ORFs) which seemed to encode a two-component signal transduction system. We also found that six of the mutants had insertions in a gene, fimS, a homologue of the genes encoding sensor kinase, and that the insertion in the remaining one disrupted the gene immediately downstream, fimR, a homologue of the response regulator genes in other bacteria. These findings suggest that this two-component regulatory system is involved in fimbriation of P. gingivalis.

S-layers: principles and applications

PubMed Central

Sleytr, Uwe B; Schuster, Bernhard; Egelseer, Eva-Maria; Pum, Dietmar

2014-01-01

Monomolecular arrays of protein or glycoprotein subunits forming surface layers (S-layers) are one of the most commonly observed prokaryotic cell envelope components. S-layers are generally the most abundantly expressed proteins, have been observed in species of nearly every taxonomical group of walled bacteria, and represent an almost universal feature of archaeal envelopes. The isoporous lattices completely covering the cell surface provide organisms with various selection advantages including functioning as protective coats, molecular sieves and ion traps, as structures involved in surface recognition and cell adhesion, and as antifouling layers. S-layers are also identified to contribute to virulence when present as a structural component of pathogens. In Archaea, most of which possess S-layers as exclusive wall component, they are involved in determining cell shape and cell division. Studies on structure, chemistry, genetics, assembly, function, and evolutionary relationship of S-layers revealed considerable application potential in (nano)biotechnology, biomimetics, biomedicine, and synthetic biology. PMID:24483139

Conserved regions of ribonucleoprotein ribonuclease MRP are involved in interactions with its substrate.

PubMed

Esakova, Olga; Perederina, Anna; Berezin, Igor; Krasilnikov, Andrey S

2013-08-01

Ribonuclease (RNase) MRP is a ubiquitous and essential site-specific eukaryotic endoribonuclease involved in the metabolism of a wide range of RNA molecules. RNase MRP is a ribonucleoprotein with a large catalytic RNA moiety that is closely related to the RNA component of RNase P, and multiple proteins, most of which are shared with RNase P. Here, we report the results of an ultraviolet-cross-linking analysis of interactions between a photoreactive RNase MRP substrate and the Saccharomyces cerevisiae RNase MRP holoenzyme. The results show that the substrate interacts with phylogenetically conserved RNA elements universally found in all enzymes of the RNase P/MRP family, as well as with a phylogenetically conserved RNA region that is unique to RNase MRP, and demonstrate that four RNase MRP protein components, all shared with RNase P, interact with the substrate. Implications for the structural organization of RNase MRP and the roles of its components are discussed.

The Overgrid Interface for Computational Simulations on Overset Grids

NASA Technical Reports Server (NTRS)

Chan, William M.; Kwak, Dochan (Technical Monitor)

2002-01-01

Computational simulations using overset grids typically involve multiple steps and a variety of software modules. A graphical interface called OVERGRID has been specially designed for such purposes. Data required and created by the different steps include geometry, grids, domain connectivity information and flow solver input parameters. The interface provides a unified environment for the visualization, processing, generation and diagnosis of such data. General modules are available for the manipulation of structured grids and unstructured surface triangulations. Modules more specific for the overset approach include surface curve generators, hyperbolic and algebraic surface grid generators, a hyperbolic volume grid generator, Cartesian box grid generators, and domain connectivity: pre-processing tools. An interface provides automatic selection and viewing of flow solver boundary conditions, and various other flow solver inputs. For problems involving multiple components in relative motion, a module is available to build the component/grid relationships and to prescribe and animate the dynamics of the different components.

Component Pin Recognition Using Algorithms Based on Machine Learning

NASA Astrophysics Data System (ADS)

Xiao, Yang; Hu, Hong; Liu, Ze; Xu, Jiangchang

2018-04-01

The purpose of machine vision for a plug-in machine is to improve the machine’s stability and accuracy, and recognition of the component pin is an important part of the vision. This paper focuses on component pin recognition using three different techniques. The first technique involves traditional image processing using the core algorithm for binary large object (BLOB) analysis. The second technique uses the histogram of oriented gradients (HOG), to experimentally compare the effect of the support vector machine (SVM) and the adaptive boosting machine (AdaBoost) learning meta-algorithm classifiers. The third technique is the use of an in-depth learning method known as convolution neural network (CNN), which involves identifying the pin by comparing a sample to its training. The main purpose of the research presented in this paper is to increase the knowledge of learning methods used in the plug-in machine industry in order to achieve better results.

A Writing and Ethics Component for a Quantum Mechanics, Physical Chemistry Course

ERIC Educational Resources Information Center

Reilly, John T.; Strickland, Michael

2010-01-01

A writing-across-the-curriculum and ethics component is presented for a second-semester, physical chemistry course. The activity involves introducing ethical issues pertinent to scientists. Students are asked to read additional material, participate in discussions, and write essays and a paper on an ethical issue. The writing and discussion…

Decreasing Inappropriate Vocalizations Using Classwide Group Contingencies and Color Wheel Procedures: A Component Analysis

ERIC Educational Resources Information Center

Kirk, Emily R.; Becker, Jennifer A.; Skinner, Christopher H., Fearrington, Jamie Yarbr; McCane-Bowling, Sara J.; Amburn, Christie; Luna, Elisa; Greear, Corinne

2010-01-01

Teacher referrals for consultation resulted in two independent teams collecting evidence that allowed for a treatment component evaluation of color wheel (CW) procedures and/or interdependent group-oriented reward (IGOR) procedures on inappropriate vocalizations in one third- and one first-grade classroom. Both studies involved the application of…

Dance band on the Titanic: biomechanical signaling in cardiac hypertrophy.

PubMed

Sussman, Mark A; McCulloch, Andrew; Borg, Thomas K

2002-11-15

Biomechanical signaling is a complex interaction of both intracellular and extracellular components. Both passive and active components are involved in the extracellular environment to signal through specific receptors to multiple signaling pathways. This review provides an overview of extracellular matrix, specific receptors, and signaling pathways for biomechanical stimulation in cardiac hypertrophy.

Interprofessional Anatomy Education in the United Kingdom and Ireland: Perspectives from Students and Teachers

ERIC Educational Resources Information Center

Smith, Claire F.; Hall, Samuel; Border, Scott; Adds, Philip J.; Finn, Gabrielle M.

2015-01-01

There is increasing recognition of multiprofessional learning in anatomy and its role in medical and healthcare professions. This study utilized two components to investigate anatomy interprofessional education (AIPE) in the United Kingdom and Ireland. First, a survey involving qualitative and quantitative components asked Heads of Anatomy to…

Using Theory to Support Classroom Teachers as Physical Activity Promoters

ERIC Educational Resources Information Center

Egan, Catherine A.; Webster, Collin A.

2018-01-01

Recently, there has been growing attention on the importance of the staff involvement component of a comprehensive school physical activity program (CSPAP). In particular, classroom teachers (CTs) are increasingly being called upon to promote physical activity (PA) in their classrooms as part of the PA during school component of a CSPAP.…

Anatomy and Selected Biomechanical Aspects of the Shoulder.

ERIC Educational Resources Information Center

Keene, James S.

This paper focuses on the anatomy and functions of the shoulder that are relevant to the evaluation and treatment of athletic injuries. A discussion is presented on the four basic components of the shoulder mechanism: (1) super structure--bony components; (2) moving parts--joints involved; (3) motor power--musculature; and (4) communications…

CD-ROM Network Configurations: Good, Better, Best!

ERIC Educational Resources Information Center

McClanahan, Gloria

1996-01-01

Rates three methods of arranging CD-ROM school networks: (1) peer-to-peer; (2) daisy chain configurations; and (3) dedicated CD-ROM file server. Describes the following network components: the file server, network adapters and wiring, the CD-ROM file server, and CD-ROM drives. Discusses issues involved in assembling these components into a working…

Tracking the Use of Ada in Commercial Applications; Case Studies and Summary Report. Revision.

DTIC Science & Technology

1988-01-09

Promoting a reusable component technology enforcing the separation of components. Th FraCADE is a trademark of Dowell-Schlumberger. 1 Hydraulic ... fracturing involves injection of a non-reactive fluid under very high pressure into a well to create a fracture within an oil reservoir. The fracture itself

Facial Speech Gestures: The Relation between Visual Speech Processing, Phonological Awareness, and Developmental Dyslexia in 10-Year-Olds

ERIC Educational Resources Information Center

Schaadt, Gesa; Männel, Claudia; van der Meer, Elke; Pannekamp, Ann; Friederici, Angela D.

2016-01-01

Successful communication in everyday life crucially involves the processing of auditory and visual components of speech. Viewing our interlocutor and processing visual components of speech facilitates speech processing by triggering auditory processing. Auditory phoneme processing, analyzed by event-related brain potentials (ERP), has been shown…

How-to-Do-It: A Physical Model Illustrating Protein Synthesis on the Ribosome.

ERIC Educational Resources Information Center

Rogerson, Allen C.; Cheney, Richard W., Jr.

1989-01-01

Describes a way to help students grasp intermediate steps in the movement and relationships of the various components involved in the addition of an amino acid to a nascent peptide chain. Includes drawings of the model in operation, construction details, and suggested shapes and labeling of components. (RT)

Developing dimensions for a multicomponent multidisciplinary approach to obesity management: a qualitative study.

PubMed

Cochrane, Anita J; Dick, Bob; King, Neil A; Hills, Andrew P; Kavanagh, David J

2017-10-16

There have been consistent recommendations for multicomponent and multidisciplinary approaches for obesity management. However, there is no clear agreement on the components, disciplines or processes to be considered within such an approach. In this study, we explored multicomponent and multidisciplinary approaches through an examination of knowledge, skills, beliefs, and recommendations of stakeholders involved in obesity management. These stakeholders included researchers, practitioners, educators, and patients. We used qualitative action research methods, including convergent interviewing and observation, to assist the process of inquiry. The consensus was that a multicomponent and multidisciplinary approach should be based on four central meta-components (patient, practitioner, process, and environmental factors), and specific components of these factors were identified. Psychologists, dieticians, exercise physiologists and general practitioners were nominated as key practitioners to be included. A complex condition like obesity requires that multiple components be addressed, and that both patients and multiple disciplines are involved in developing solutions. Implementing cycles of continuous improvement to deal with complexity, instead of trying to control for it, offers an effective way to deal with complex, changing multisystem problems like obesity.

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

Shah, Kedar G.; Pannu, Satinderpall S.

An integrated circuit system having an integrated circuit (IC) component which is able to have its functionality destroyed upon receiving a command signal. The system may involve a substrate with the IC component being supported on the substrate. A module may be disposed in proximity to the IC component. The module may have a cavity and a dissolving compound in a solid form disposed in the cavity. A heater component may be configured to heat the dissolving compound to a point of sublimation where the dissolving compound changes from a solid to a gaseous dissolving compound. A triggering mechanism maymore » be used for initiating a dissolution process whereby the gaseous dissolving compound is allowed to attack the IC component and destroy a functionality of the IC component.« less

Two Methods for Teaching Simple Visual Discriminations to Learners with Severe Disabilities

ERIC Educational Resources Information Center

Graff, Richard B.; Green, Gina

2004-01-01

Simple discriminations are involved in many functional skills; additionally, they are components of conditional discriminations (identity and arbitrary matching-to-sample), which are involved in a wide array of other important performances. Many individuals with severe disabilities have difficulty acquiring simple discriminations with standard…

Auditory Pattern Recognition and Brief Tone Discrimination of Children with Reading Disorders

ERIC Educational Resources Information Center

Walker, Marianna M.; Givens, Gregg D.; Cranford, Jerry L.; Holbert, Don; Walker, Letitia

2006-01-01

Auditory pattern recognition skills in children with reading disorders were investigated using perceptual tests involving discrimination of frequency and duration tonal patterns. A behavioral test battery involving recognition of the pattern of presentation of tone triads was used in which individual components differed in either frequency or…

Family Night Out: An After School Program.

ERIC Educational Resources Information Center

Boileau, Penny L.

Discovering the value of after-school programs to school improvement initiatives and student achievement, one school district implemented a parent involvement component. Goals identified for the program were: to provide opportunities for parents and school staff to work as partners, and to share information about parent involvement and assets to…

Electrodynamics in One Dimension: Radiation and Reflection

ERIC Educational Resources Information Center

Asti, G.; Coisson, R.

2011-01-01

Problems involving polarized plane waves and currents on sheets perpendicular to the wavevector involve only one component of the fields, so it is possible to discuss electrodynamics in one dimension. Taking for simplicity linearly polarized sinusoidal waves, we can derive the field emitted by currents (analogous to dipole radiation in three…

An Inorganic Laboratory Experiment Involving Photochemistry, Liquid Chromatography, and Infrared Spectroscopy.

ERIC Educational Resources Information Center

Post, Elroy W.

1980-01-01

Presents an experiment involving photochemical legand displacement on a metal carbonyl, separation of the product mixture by chromotography, and identification of the components by use of infrared spectroscopy and group theory. The chromatography and spectroscopy are combined as complementary tools in this experiment. (Author/JN)

Language: Critical Components in Readers with Criminal Referral History

ERIC Educational Resources Information Center

Platt, Derrick E.

2009-01-01

Low levels of reading performance are associated with delinquency. However, few studies have investigated the relationship between early involvement in the justice system and reading problems. This study examined the relationship between youth at various early stages of involvement with criminal behaviors and reading abilities (specifically,…

Extending Volunteer Programs in Schools.

ERIC Educational Resources Information Center

Hedges, Henry G.

Documented here is a project involving three extensions or adaptations for using volunteers in schools. The first adaptation involves a plan for meeting certain major needs of a secondary school with volunteer help. This plan includes components designed to reorganize the secondary school curriculum to allow some of the students to study aspects…

Educational and Service Outcomes of a Service Integration Effort.

ERIC Educational Resources Information Center

Greene, David; Diehm, Gwen

1995-01-01

Study investigated the effects of a service-learning component in an undergraduate occupational therapy course. Comparisons were made between students involved in service-learning and those not involved of how they perceived institutionalized older adults' perspectives on disease and aging. Also evaluated were weekly journal entries of the…

Using Independent Research Projects to Foster Learning in the Comparative Vertebrate Anatomy Laboratory

ERIC Educational Resources Information Center

Ghedotti, Michael J.; Fielitz, Christopher; Leonard, Daniel J.

2005-01-01

This paper presents a teaching methodology involving an independent research project component for use in undergraduate Comparative Vertebrate Anatomy laboratory courses. The proposed project introduces cooperative, active learning in a research context to comparative vertebrate anatomy. This project involves pairs or groups of three students…

Commonalities in the central nervous system's involvement with complementary medical therapies: limbic morphinergic processes.

PubMed

Esch, Tobias; Guarna, Massimo; Bianchi, Enrica; Zhu, Wei; Stefano, George B

2004-06-01

Currently, complementary and alternative medicine (CAM) are experiencing growing popularity, especially in former industrialized countries. However, most of the underlying physiological and molecular mechanisms as well as participating biological structures are still speculative. Specific and non-specific effects may play a role in CAM. Moreover, trust, belief, and expectation may be of importance, pointing towards common central nervous system (CNS) pathways involved in CAM. Four CAM approaches (acupuncture, meditation, music therapy, and massage therapy) were examined with regard to the CNS activity pattern involved. CNS commonalities between different approaches were investigated. Frontal/prefrontal and limbic brain structures play a role in CAM. Particularly, left-anterior regions of the brain and reward or motivation circuitry constituents are involved, indicating positive affect and emotion-related memory processing--accompanied by endocrinologic and autonomic functions--as crucial components of CAM effects. Thus, trust and belief in a therapist or positive therapy expectations seem to be important. However, besides common non-specific or subjective effects, specific (objective) physiological components also exist. Non-specific CNS commonalities are involved in various CAM therapies. Different therapeutic approaches physiologically overlap in the brain. However, molecular correspondents of the detected CNS analogies still have to be specified. In particular, fast acting autoregulatory signaling molecules presumably play a role. These may also be involved in the placebo response.

Analysis of inflammasomes and antiviral sensing components reveals decreased expression of NLRX1 in HIV-positive patients assuming efficient antiretroviral therapy.

PubMed

Nasi, Milena; De Biasi, Sara; Bianchini, Elena; Digaetano, Margherita; Pinti, Marcello; Gibellini, Lara; Pecorini, Simone; Carnevale, Gianluca; Guaraldi, Giovanni; Borghi, Vanni; Mussini, Cristina; Cossarizza, Andrea

2015-09-24

Few studies have investigated the importance of different components of the inflammasome system and of innate mitochondrial sensing (IMS) pathways in HIV infection and its treatment. We analysed the expression of several components of the inflammasome and of the IMS in HIV-positive patients taking successful combination antiretroviral therapy (cART). We enrolled 20 HIV-positive patients under cART, who achieved viral suppression since at least 10 months and 20 age and sex-matched healthy donors. By RT-PCR, using peripheral blood mononuclear cells (PBMCs), we quantified the mRNA expression of 16 genes involved in inflammasome activation and regulation (AIM2, NAIP, PYCARD, CASP1, CASP5, NLRP6, NLRP1, NLRP3, TXNIP, BCL2, NLRC4, PANX1, P2RX7, IL-18, IL-1β, SUGT1) and eight genes involved in IMS (MFN2, MFN1, cGAS, RIG-I, MAVS, NLRX1, RAB32, STING). Compared with controls, HIV-positive patients showed significantly lower mRNA levels of the mitochondrial protein NLRX1, which plays a key role in regulating apoptotic cell death; main PBMC subpopulations behave in a similar manner. No differences were observed in the expression of inflammasome components, which however showed complex correlations. The decreased level of NLRX1 in HIV infection could suggest that the virus is able to downregulate mechanisms linked to triggering of cell death in several immune cell types. The fact that HIV-positive patients did not show altered expression of inflammasome components, nor of most genes involved in IMS, suggests that the infection and/or the chronic immune activation does not influence the transcriptional machinery of innate mechanisms able to trigger inflammation at different levels.

The National Heart, Lung, and Blood Institute Recipient Epidemiology and Donor Evaluation Study (REDS-III): A research program striving to improve blood donor and transfusion recipient outcomes

PubMed Central

Kleinman, Steven; Busch, Michael P; Murphy, Edward L; Shan, Hua; Ness, Paul; Glynn, Simone A.

2014-01-01

Background The Recipient Epidemiology and Donor Evaluation Study -III (REDS-III) is a 7-year multicenter transfusion safety research initiative launched in 2011 by the National Heart, Lung, and Blood Institute. Study design The domestic component involves 4 blood centers, 12 hospitals, a data coordinating center, and a central laboratory. The international component consists of distinct programs in Brazil, China, and South Africa which involve US and in-country investigators. Results REDS-III is using two major methods to address key research priorities in blood banking/transfusion medicine. First, there will be numerous analyses of large “core” databases; the international programs have each constructed a donor/donation database while the domestic program has established a detailed research database that links data from blood donors and their donations, the components made from these donations, and data extracts from the electronic medical records of the recipients of these components. Secondly, there are more than 25 focused research protocols involving transfusion recipients, blood donors, or both that are either in progress or scheduled to begin within the next 3 years. Areas of study include transfusion epidemiology and blood utilization; transfusion outcomes; non-infectious transfusion risks; HIV-related safety issues (particularly in the international programs); emerging infectious agents; blood component quality; donor health and safety; and other donor issues. Conclusions It is intended that REDS-III serve as an impetus for more widespread recipient and linked donor-recipient research in the US as well as to help assure a safe and available blood supply in the US and in international locations. PMID:24188564

Real Time Monitoring of Dissolved Organic Carbon Concentration and Disinfection By-Product Formation Potential in a Surface Water Treatment Plant with Simulaneous UV-VIS Absorbance and Fluorescence Excitation-Emission Mapping

NASA Astrophysics Data System (ADS)

Gilmore, A. M.

2015-12-01

This study describes a method based on simultaneous absorbance and fluorescence excitation-emission mapping for rapidly and accurately monitoring dissolved organic carbon concentration and disinfection by-product formation potential for surface water sourced drinking water treatment. The method enables real-time monitoring of the Dissolved Organic Carbon (DOC), absorbance at 254 nm (UVA), the Specific UV Absorbance (SUVA) as well as the Simulated Distribution System Trihalomethane (THM) Formation Potential (SDS-THMFP) for the source and treated water among other component parameters. The method primarily involves Parallel Factor Analysis (PARAFAC) decomposition of the high and lower molecular weight humic and fulvic organic component concentrations. The DOC calibration method involves calculating a single slope factor (with the intercept fixed at 0 mg/l) by linear regression for the UVA divided by the ratio of the high and low molecular weight component concentrations. This method thus corrects for the changes in the molecular weight component composition as a function of the source water composition and coagulation treatment effects. The SDS-THMFP calibration involves a multiple linear regression of the DOC, organic component ratio, chlorine residual, pH and alkalinity. Both the DOC and SDS-THMFP correlations over a period of 18 months exhibited adjusted correlation coefficients with r2 > 0.969. The parameters can be reported as a function of compliance rules associated with required % removals of DOC (as a function of alkalinity) and predicted maximum contaminant levels (MCL) of THMs. The single instrument method, which is compatible with continuous flow monitoring or grab sampling, provides a rapid (2-3 minute) and precise indicator of drinking water disinfectant treatability without the need for separate UV photometric and DOC meter measurements or independent THM determinations.

Gene Network Polymorphism Illuminates Loss and Retention of Novel RNAi Silencing Components in the Cryptococcus Pathogenic Species Complex.

PubMed

Feretzaki, Marianna; Billmyre, R Blake; Clancey, Shelly Applen; Wang, Xuying; Heitman, Joseph

2016-03-01

RNAi is a ubiquitous pathway that serves central functions throughout eukaryotes, including maintenance of genome stability and repression of transposon expression and movement. However, a number of organisms have lost their RNAi pathways, including the model yeast Saccharomyces cerevisiae, the maize pathogen Ustilago maydis, the human pathogen Cryptococcus deuterogattii, and some human parasite pathogens, suggesting there may be adaptive benefits associated with both retention and loss of RNAi. By comparing the RNAi-deficient genome of the Pacific Northwest Outbreak C. deuterogattii strain R265 with the RNAi-proficient genomes of the Cryptococcus pathogenic species complex, we identified a set of conserved genes that were lost in R265 and all other C. deuterogattii isolates examined. Genetic and molecular analyses reveal several of these lost genes play roles in RNAi pathways. Four novel components were examined further. Znf3 (a zinc finger protein) and Qip1 (a homolog of N. crassa Qip) were found to be essential for RNAi, while Cpr2 (a constitutive pheromone receptor) and Fzc28 (a transcription factor) are involved in sex-induced but not mitosis-induced silencing. Our results demonstrate that the mitotic and sex-induced RNAi pathways rely on the same core components, but sex-induced silencing may be a more specific, highly induced variant that involves additional specialized or regulatory components. Our studies further illustrate how gene network polymorphisms involving known components of key cellular pathways can inform identification of novel elements and suggest that RNAi loss may have been a core event in the speciation of C. deuterogattii and possibly contributed to its pathogenic trajectory.

Status of the Flooding Fragility Testing Development

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

Pope, C. L.; Savage, B.; Bhandari, B.

2016-06-01

This report provides an update on research addressing nuclear power plant component reliability under flooding conditions. The research includes use of the Component Flooding Evaluation Laboratory (CFEL) where individual components and component subassemblies will be tested to failure under various flooding conditions. The resulting component reliability data can then be incorporated with risk simulation strategies to provide a more thorough representation of overall plant risk. The CFEL development strategy consists of four interleaved phases. Phase 1 addresses design and application of CFEL with water rise and water spray capabilities allowing testing of passive and active components including fully electrified components.more » Phase 2 addresses research into wave generation techniques followed by the design and addition of the wave generation capability to CFEL. Phase 3 addresses methodology development activities including small scale component testing, development of full scale component testing protocol, and simulation techniques including Smoothed Particle Hydrodynamic (SPH) based computer codes. Phase 4 involves full scale component testing including work on full scale component testing in a surrogate CFEL testing apparatus.« less

Color enhancement of landsat agricultural imagery: JPL LACIE image processing support task

NASA Technical Reports Server (NTRS)

Madura, D. P.; Soha, J. M.; Green, W. B.; Wherry, D. B.; Lewis, S. D.

1978-01-01

Color enhancement techniques were applied to LACIE LANDSAT segments to determine if such enhancement can assist analysis in crop identification. The procedure involved increasing the color range by removing correlation between components. First, a principal component transformation was performed, followed by contrast enhancement to equalize component variances, followed by an inverse transformation to restore familiar color relationships. Filtering was applied to lower order components to reduce color speckle in the enhanced products. Use of single acquisition and multiple acquisition statistics to control the enhancement were compared, and the effects of normalization investigated. Evaluation is left to LACIE personnel.

Structural bioinformatics of the human spliceosomal proteome

PubMed Central

Korneta, Iga; Magnus, Marcin; Bujnicki, Janusz M.

2012-01-01

In this work, we describe the results of a comprehensive structural bioinformatics analysis of the spliceosomal proteome. We used fold recognition analysis to complement prior data on the ordered domains of 252 human splicing proteins. Examples of newly identified domains include a PWI domain in the U5 snRNP protein 200K (hBrr2, residues 258–338), while examples of previously known domains with a newly determined fold include the DUF1115 domain of the U4/U6 di-snRNP protein 90K (hPrp3, residues 540–683). We also established a non-redundant set of experimental models of spliceosomal proteins, as well as constructed in silico models for regions without an experimental structure. The combined set of structural models is available for download. Altogether, over 90% of the ordered regions of the spliceosomal proteome can be represented structurally with a high degree of confidence. We analyzed the reduced spliceosomal proteome of the intron-poor organism Giardia lamblia, and as a result, we proposed a candidate set of ordered structural regions necessary for a functional spliceosome. The results of this work will aid experimental and structural analyses of the spliceosomal proteins and complexes, and can serve as a starting point for multiscale modeling of the structure of the entire spliceosome. PMID:22573172

[Investigation on contamination of Cryptosporidium and Giardia in drinking water and environmental water in Shanghai].

PubMed

Zhang, Xiao-Ping; He, Yan-Yan; Zhu, Qian; Ma, Xiao-Jiang; Cai, Li

2010-12-30

To understand the contamination status of Cryptosporidium sp. and Giardia lamblia in drinking water, source water and environmental water in Shanghai. All water samples collected from drinking water, source water and environmental water were detected by a procedure of micromembrane filtration, immune magnetic separation (IMS), and immunofluorescent assay (IFA). Cryptosporidium oocysts and Giardia cysts were not found in 156 samples of the drinking water including finished water, tap water, or pipe water for directly drinking in communities. Among 70 samples either source water of water plants (15 samples), environmental water from Huangpu River(25), canal water around animal sheds(15), exit water from waste-water treatment plants(9), or waste water due to daily life(6), Cryptosporidium oocysts were detected in 1(6.7%), 2(8.0%), 7(46.7%), 1(11.1%), and 1(16.7%) samples, respectively; and Giardia cysts were detected in 1(6.7%), 3(12.0%), 6 (40.0%), 2(22.2%), and 2(33.3%), respectively. The positive rate of Cryptosporidium oocysts and Giardia cysts was 17.1% (12/70) and 20.0% (14/70), respectively. No Cryptosporidium oocysts and Giardia cysts have been detected in drinking water, but found in source water and environmental water samples in Shanghai.

Prevalence of Intestinal Parasites in Bakery Workers in Khorramabad, Lorestan Iran

PubMed Central

Kheirandish, F; Tarahi, MJ; Haghighi, A; Nazemalhosseini- Mojarad, E; Kheirandish, M

2011-01-01

Background Food contamination may occur through production, processing, distribution and preparation. In Iran especially in Khorramabad, 33° 29' 16" North, 48° 21' 21" East, due to kind of nutrition, culture and economic status of people, bread is a part of the main meal and the consumption of bread is high. In this study, the bakery workers were studied for determining of intestinal parasites prevalence. Methods The study was carried out during September to November 2010 in Khorramabad. All the 278 bakeries and the bakery workers including 816 people were studied in a census method and their feces were examined for the presence of parasites by direct wet-mount, Lugol's iodine solution, and formaldehyde-ether sedimentation, trichrome staining, and single round PCR (For discrimination of Entamoeba spp). Results Ninety-six (11.9%) stool specimens were positive for different intestinal parasites. Intestinal parasites included Giardia lamblia 3.7%, Entamoeba coli 5.5%, Blastocystis sp. 2.1%, Entamoeba dispar 0.4%, Hymenolepis nana 0.1%, and Blastocystis sp. 0.1%. Conclusion In order to reduce the contamination in these persons, some cases such as stool exam every three months with concentration methods, supervision and application of accurate health rules by health experts, training in transmission of parasites are recommended. PMID:22347316

Water quality monitoring using an automated portable fiber optic biosensor: RAPTOR

NASA Astrophysics Data System (ADS)

Anderson, George P.; Rowe-Taitt, Chris A.

2001-03-01

The RAPTOR is a portable, automated biosensor capable of performing rapid, ten-minute assays on a sample for four target analytes simultaneously. Samples are analyzed using a fluorescent sandwich immunoassay on the surface of short polystyrene optical probes with capture antibody adsorbed to the probe surface. Target analytes bound to the fiber by capture antibodies are detected with fluorescently labeled tracer antibodies, which are held in a separate reservoir. Since target recognition is a two-step process, selectivity is enhanced, and the optical probes can be reused up to forty times, or until a positive result is obtained. This greatly reduces the logistical burden for field operations. Numerous assays for toxins, such as SEB and ricin, and bacteria, such as Bacillus anthracis and Francisella tularensis, have been developed for the RAPTOR. An assay of particular interest for water quality monitoring and the screening of fruits and vegetables is detection of Giardia cysts. Giardia lamblia is a parasitic protozoan common in the developing world that causes severe intestinal infections. Thus, a simple field assay for screening water supplies would be highly useful. Such an assay has been developed using the RAPTOR. The detection limit for Giardia cysts was 5x104/ml for a 10-minute assay.

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

PubMed

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

2007-09-01

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

Intestinal parasitosis and anaemia among patients in a Health Center, North Ethiopia.

PubMed

Alemu, Megbaru; Kinfe, Birhane; Tadesse, Desalegn; Mulu, Wondemagegn; Hailu, Tadesse; Yizengaw, Endalew

2017-11-28

The aim of this cross-sectional study was to determine the magnitude of intestinal parasitosis and anaemia in a Health Center, North Ethiopia. A total of 427 outpatients were enrolled and the median age of the participants was 22 years. The prevalence of intestinal parasitosis was 143 (33.5%). Age, place of residence and occupation were significantly associated with intestinal parasitosis. When we see parasite specific factors, significant associations were observed for source of drinking water (P = 0.02), age (P < 0.001) and family size (P = 0.003), respectively with Entameba histolytica, Hookworm and Giardia lamblia infections. The overall prevalence of anaemia was 35 (8.2%). The mean haemoglobin concentration among the study participants was 12.8 mg/dl. The highest prevalence of anemia was recorded for the age group of 15-19 years (29.6%). The proportion of anemia among intestinal parasite -infected and non-infected participants was 10.7 and 7.0%, respectively. Study participants infected with S. stercoralis and hookworm were more likely to develop anaemia than the non- infected ones; AOR (adjusted odds ratio) = 5.3, 95% CI (1.01-27.4); P = 0.028 and AOR = 11.1, 95% CI (3.36-36.9); P = 0.000, respectively.

Intestinal Parasitic Infections among Pregnant Women in Venezuela

PubMed Central

Rodríguez-Morales, Alfonso J.; Barbella, Rosa A.; Case, Cynthia; Arria, Melissa; Ravelo, Marisela; Perez, Henry; Urdaneta, Oscar; Gervasio, Gloria; Rubio, Nestor; Maldonado, Andrea; Aguilera, Ymora; Viloria, Anna; Blanco, Juan J.; Colina, Magdary; Hernández, Elizabeth; Araujo, Elianet; Cabaniel, Gilberto; Benitez, Jesús; Rifakis, Pedro

2006-01-01

Introduction. Intestinal parasitic infections, especially due to helminths, increase anemia in pregnant women. The results of this are low pregnancy weight gain and IUGR, followed by LBW, with its associated greater risks of infection and higher perinatal mortality rates. For these reasons, in the setting of no large previous studies in Venezuela about this problem, a national multicentric study was conducted. Methods. Pregnant women from nine states were studied, a prenatal evaluation with a coproparasitological study. Univariated and multivariated analyses were made to determine risk factors for intestinal parasitosis and related anemia. Results. During 19 months, 1038 pregnant women were included and evaluated. Intestinal parasitosis was evidenced in 73.9%: A lumbricoides 57.0%, T trichiura 36.0%, G lamblia 14.1%, E hystolitica 12.0%, N americanus 8.1%, E vermicularis 6.3%, S stercoralis 3.3%. Relative risk for anemia in those women with intestinal parasitosis was 2.56 (P < .01). Discussion. Intestinal parasitoses could be associated with conditions for development of anemia at pregnancy. These features reflect the need of routine coproparasitological study among pregnant women in rural and endemic zones for intestinal parasites. Further therapeutic and prophylactic protocols are needed. Additional research on pregnant intestinal parasitic infection impact on newborn health is also considered. PMID:17093349

[Giant gastric ulcer by cytomegalovirus in infection VIH/SIDA].

PubMed

Pérez-Pereyra, Julia; Morales, Domingo; Díaz, Ramiro; Yoza, Max; Frisancho, Oscar

2008-01-01

Cytomegalovirus infection is an important cause of morbidity in immunosupressed patients with Human Immunodeficiency Virus (HIV). In this paper we present a 43 years old man with renal failure under hemodialysis, several blood transfusions because of anemia and three months of disease characterized by epigastric pain, specially at nights, ameliorated with antacid drugs. Other symptoms were early satisfy, vomits and weigh loss (18Kg). At clinical exam, the patient was pallid, presented adenopathies at cervical and inguinal regions and had a pain at epigastric region in profound touch palpation. The most important exams were HB: 10mg/dl, CMV: 83.5, leukocytes 7000, lymphocytes: 1715, erythrocyte sedimentation rate 49mm/h, the venon test (-), and Giardia lamblia trophozoites in stools. The studies demonstrated the patient was seropositive for HIV and the tests for IgG CMV and IgG Herpes virus resulted seropositives too. At endoscopy the esophagus mucosa was covered by a white plaque which suggests candida infection. In the stomach, over the body gastric, we found a big and deep ulcerated lesion (45 x 41mm), with defined rims and white fund. Biopsy from the edges of the gastric ulcer had the characteristic CMV intranuclear and intracytoplasmic inclusions; we confirmed the diagnosis by immunohystochemistry. The patient receives ganciclovir an then HAART and is getting well.

Crystal structure and tartrate inhibition of Legionella pneumophila histidine acid phosphatase.

PubMed

Dhatwalia, Richa; Singh, Harkewal; Reilly, Thomas J; Tanner, John J

2015-11-01

Histidine acid phosphatases (HAPs) utilize a nucleophilic histidine residue to catalyze the transfer of a phosphoryl group from phosphomonoesters to water. HAPs function as protein phosphatases and pain suppressors in mammals, are essential for Giardia lamblia excystation, and contribute to virulence of the category A pathogen Francisella tularensis. Herein we report the first crystal structure and steady-state kinetics measurements of the HAP from Legionella pneumophila (LpHAP), also known as Legionella major acid phosphatase. The structure of LpHAP complexed with the inhibitor l(+)-tartrate was determined at 2.0 Å resolution. Kinetics assays show that l(+)-tartrate is a 50-fold more potent inhibitor of LpHAP than of other HAPs. Electrostatic potential calculations provide insight into the basis for the enhanced tartrate potency: the tartrate pocket of LpHAP is more positive than other HAPs because of the absence of an ion pair partner for the second Arg of the conserved RHGXRXP HAP signature sequence. The structure also reveals that LpHAP has an atypically expansive active site entrance and lacks the nucleotide substrate base clamp found in other HAPs. These features imply that nucleoside monophosphates may not be preferred substrates. Kinetics measurements confirm that AMP is a relatively inefficient in vitro substrate of LpHAP. Copyright © 2015 Elsevier Inc. All rights reserved.

Detection of enteropathogens in diarrhoeal diseases among malnourished Egyptian infant and children.

PubMed

Hassan, E M; el-Meneza, S A; el-Rashidy, Z; Rashad, R; Rabie, S; Fahmy, S A

1989-01-01

The influence of the Pre-existing malnutrition (PEM) on the severity of diarrhoea as well as the causative organisms was studied on 60 cases. The duration of diarrhoea was prolonged in cases with PEM. The stool purgative rate ranged from 4-15 times/day in PEM infant while it was 3-6 times in well nourished cases (WNC) (P less than 0.05). Also vomiting and dehydration was more marked among PEM cases (52.9% and 32.4% of cases than in WNC cases (31.3% and 12.5% of cases) (P less than 0.05). Rota virus and Candida albicans were the Commonest identified organisms in the stools of the PEM cases, they were detected in 52% and 38.2% of cases respectively while 25% of WNC had rota virus in their stool and non of them had Candida (P less than 0.02). Giardia lamblia was detected in 23.5% and 18.8% of PEM and WNC while 10% of healthy controls had Giardia. Other bacterial enteropathogen were also found less frequently including Salmonella, Shigella, E. coli, Pseudomonas and Campylobacter. There was no statistical difference in the incidence between both groups. Multiple infections were detected in 47% and 18.7% of PEM cases and WNC (P less than 0.05) and correlated with the severity of illness.

Intestinal parasitism among waste pickers in Mato Grosso do Sul, Midwest Brazil

PubMed Central

Higa, Minoru German; Cardoso, Wesley Márcio; Weis, Sabrina Moreira dos Santos; França, Adriana de Oliveira; Pontes, Elenir Rose Jardim Cury; da Silva, Patrícia Vieira; de Oliveira, Márcia Pereira; Dorval, Maria Elizabeth Moraes Cavalheiros

2017-01-01

ABSTRACT The purpose of this study was to estimate the prevalence of intestinal parasites in both cooperative-affiliated and independent waste pickers operating at the municipal sanitary landfill in Campo Grande, Mato Grosso do Sul, Brazil, and associate these findings with hemoglobin, eosinophils, vitamin A and C levels and interleukin 5 and 10 (IL-5 and IL-10) production. Biological samples were collected, in addition to clinical, epidemiological, and sociodemographic data. Stool analyzes were based on sedimentation by centrifugation and on spontaneous sedimentation. High-performance liquid chromatography was used to determine vitamin A and C levels. ELISA was employed to quantify interleukins. Intestinal parasites were found in 29 of the 66 subjects assessed (43.9%). Endolimax nana (22.7%), Entamoeba coli (21.1%), Giardia lamblia (6.1%), Entamoeba histolytica/E. dispar (4.5%), and Ascaris lumbricoides (4.5%) were the most prevalent species. Pathogenic parasites were detected in 11 individuals (16.7%). Hypovitaminoses A and C were detected in 19.6% (13/66) and 98.4% (65/66) of subjects, respectively. IL-5 and IL-10 production was observed in 21 (31.8%) and 32 (48.4%) subjects, respectively. Infection with pathogenic intestinal parasites was not a cause of vitamin A and C deficiency or IL-5 and IL-10 production among these workers. PMID:29267595

Dynamic protein S-palmitoylation mediates parasite life cycle progression and diverse mechanisms of virulence.

PubMed

Brown, Robert W B; Sharma, Aabha I; Engman, David M

2017-04-01

Eukaryotic parasites possess complex life cycles and utilize an assortment of molecular mechanisms to overcome physical barriers, suppress and/or bypass the host immune response, including invading host cells where they can replicate in a protected intracellular niche. Protein S-palmitoylation is a dynamic post-translational modification in which the fatty acid palmitate is covalently linked to cysteine residues on proteins by the enzyme palmitoyl acyltransferase (PAT) and can be removed by lysosomal palmitoyl-protein thioesterase (PPT) or cytosolic acyl-protein thioesterase (APT). In addition to anchoring proteins to intracellular membranes, functions of dynamic palmitoylation include - targeting proteins to specific intracellular compartments via trafficking pathways, regulating the cycling of proteins between membranes, modulating protein function and regulating protein stability. Recent studies in the eukaryotic parasites - Plasmodium falciparum, Toxoplasma gondii, Trypanosoma brucei, Cryptococcus neoformans and Giardia lamblia - have identified large families of PATs and palmitoylated proteins. Many palmitoylated proteins are important for diverse aspects of pathogenesis, including differentiation into infective life cycle stages, biogenesis and tethering of secretory organelles, assembling the machinery powering motility and targeting virulence factors to the plasma membrane. This review aims to summarize our current knowledge of palmitoylation in eukaryotic parasites, highlighting five exemplary mechanisms of parasite virulence dependent on palmitoylation.

Evolutionary game based control for biological systems with applications in drug delivery.

PubMed

Li, Xiaobo; Lenaghan, Scott C; Zhang, Mingjun

2013-06-07

Control engineering and analysis of biological systems have become increasingly important for systems and synthetic biology. Unfortunately, no widely accepted control framework is currently available for these systems, especially at the cell and molecular levels. This is partially due to the lack of appropriate mathematical models to describe the unique dynamics of biological systems, and the lack of implementation techniques, such as ultra-fast and ultra-small devices and corresponding control algorithms. This paper proposes a control framework for biological systems subject to dynamics that exhibit adaptive behavior under evolutionary pressures. The control framework was formulated based on evolutionary game based modeling, which integrates both the internal dynamics and the population dynamics. In the proposed control framework, the adaptive behavior was characterized as an internal dynamic, and the external environment was regarded as an external control input. The proposed open-interface control framework can be integrated with additional control algorithms for control of biological systems. To demonstrate the effectiveness of the proposed framework, an optimal control strategy was developed and validated for drug delivery using the pathogen Giardia lamblia as a test case. In principle, the proposed control framework can be applied to any biological system exhibiting adaptive behavior under evolutionary pressures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comprehensive system models: Strategies for evaluation

NASA Technical Reports Server (NTRS)

Field, Christopher; Kutzbach, John E.; Ramanathan, V.; Maccracken, Michael C.

1992-01-01

The task of evaluating comprehensive earth system models is vast involving validations of every model component at every scale of organization, as well as tests of all the individual linkages. Even the most detailed evaluation of each of the component processes and the individual links among them should not, however, engender confidence in the performance of the whole. The integrated earth system is so rich with complex feedback loops, often involving components of the atmosphere, oceans, biosphere, and cryosphere, that it is certain to exhibit emergent properties very difficult to predict from the perspective of a narrow focus on any individual component of the system. Therefore, a substantial share of the task of evaluating comprehensive earth system models must reside at the level of whole system evaluations. Since complete, integrated atmosphere/ ocean/ biosphere/ hydrology models are not yet operational, questions of evaluation must be addressed at the level of the kinds of earth system processes that the models should be competent to simulate, rather than at the level of specific performance criteria. Here, we have tried to identify examples of earth system processes that are difficult to simulate with existing models and that involve a rich enough suite of feedbacks that they are unlikely to be satisfactorily described by highly simplified or toy models. Our purpose is not to specify a checklist of evaluation criteria but to introduce characteristics of the earth system that may present useful opportunities for model testing and, of course, improvement.

Gray Matter Is Targeted in First-Attack Multiple Sclerosis

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

Schutzer, Steven E.; Angel, Thomas E.; Liu, Tao

The cause of multiple sclerosis (MS), its driving pathogenesis at the earliest stages, and what factors allow the first clinical attack to manifest remain unknown. Some imaging studies suggest gray rather than white matter may be involved early, and some postulate this may be predictive of developing MS. Other imaging studies are in conflict. To determine if there was objective molecular evidence of gray matter involvement in early MS we used high-resolution mass spectrometry to identify proteins in the cerebrospinal fluid (CSF) of first-attack MS patients (two independent groups) compared to established relapsing remitting (RR) MS and controls. We foundmore » that the CSF proteins in first-attack patients were differentially enriched for gray matter components (axon, neuron, synapse). Myelin components did not distinguish these groups. The results support that gray matter dysfunction is involved early in MS, and also may be integral for the initial clinical presentation.« less

Reassembling the Information Technology Innovation Process: An Actor Network Theory Method for Managing the Initiation, Production, and Diffusion of Innovations

NASA Astrophysics Data System (ADS)

Zendejas, Gerardo; Chiasson, Mike

This paper will propose and explore a method to enhance focal actors' abilities to enroll and control the many social and technical components interacting during the initiation, production, and diffusion of innovations. The reassembling and stabilizing of such components is the challenging goal of the focal actors involved in these processes. To address this possibility, a healthcare project involving the initiation, production, and diffusion of an IT-based innovation will be influenced by the researcher, using concepts from actor network theory (ANT), within an action research methodology (ARM). The experiences using this method, and the nature of enrolment and translation during its use, will highlight if and how ANT can provide a problem-solving method to help assemble the social and technical actants involved in the diffusion of an innovation. Finally, the paper will discuss the challenges and benefits of implementing such methods to attain widespread diffusion.

A plan analysis of pedophile sexual abusers' motivations for treatment: a qualitative pilot study.

PubMed

Drapeau, Martin; Körner, Annett; Granger, Luc; Brunet, Louis; Caspar, Franz

2005-06-01

Many authors have suggested adapting treatment programs to the specific needs of sexual abusers. However, little research has been conducted to understand what these patients seek in therapy or what elements play a key role in keeping them in treatment. In this pilot study, fifteen (N=15) pedophile sexual abusers from La Macaza clinic for sexual abusers were interviewed. Plan analysis was used to investigate the most prevalent components involved in staying in or leaving therapy. Results suggest that many components involved in the plans leading to doing and to avoiding treatment were similar. Differences were found in regards to the outcome of confrontations with the therapists, a tendency to isolate and overcomply, guilt related to the abuse, a need for a stable environment, and a need to be accepted. These results are discussed along with possible ways to improve the patients' involvement in treatment.

Cost-effective and compact wide-field fluorescent imaging on a cell-phone.

PubMed

Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek; Ozcan, Aydogan

2011-01-21

We demonstrate wide-field fluorescent and darkfield imaging on a cell-phone with compact, light-weight and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. For this purpose, we used battery powered light-emitting diodes (LEDs) to pump the sample of interest from the side using butt-coupling, where the pump light was guided within the sample cuvette to uniformly excite the specimen. The fluorescent emission from the sample was then imaged using an additional lens that was positioned right in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to our detection path, an inexpensive plastic colour filter was sufficient to create the dark-field background required for fluorescent imaging, without the need for a thin-film interference filter. We validate the performance of this platform by imaging various fluorescent micro-objects in 2 colours (i.e., red and green) over a large field-of-view (FOV) of ∼81 mm(2) with a raw spatial resolution of ∼20 μm. With additional digital processing of the captured cell-phone images, through the use of compressive sampling theory, we demonstrate ∼2 fold improvement in our resolving power, achieving ∼10 μm resolution without a trade-off in our FOV. Further, we also demonstrate darkfield imaging of non-fluorescent specimen using the same interface, where this time the scattered light from the objects is detected without the use of any filters. The capability of imaging a wide FOV would be exceedingly important to probe large sample volumes (e.g., >0.1 mL) of e.g., blood, urine, sputum or water, and for this end we also demonstrate fluorescent imaging of labeled white-blood cells from whole blood samples, as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts. Weighing only ∼28 g (∼1 ounce), this compact and cost-effective fluorescent imaging platform attached to a cell-phone could be quite useful especially for resource-limited settings, and might provide an important tool for wide-field imaging and quantification of various lab-on-a-chip assays developed for global health applications, such as monitoring of HIV+ patients for CD4 counts or viral load measurements.

Cost-effective and compact wide-field fluorescent imaging on a cell-phone†

PubMed Central

Zhu, Hongying; Yaglidere, Oguzhan; Su, Ting-Wei; Tseng, Derek

2011-01-01

We demonstrate wide-field fluorescent and darkfield imaging on a cell-phone with compact, light-weight and cost-effective optical components that are mechanically attached to the existing camera unit of the cell-phone. For this purpose, we used battery powered light-emitting diodes (LEDs) to pump the sample of interest from the side using butt-coupling, where the pump light was guided within the sample cuvette to uniformly excite the specimen. The fluorescent emission from the sample was then imaged using an additional lens that was positioned right in front of the existing lens of the cell-phone camera. Because the excitation occurs through guided waves that propagate perpendicular to our detection path, an inexpensive plastic colour filter was sufficient to create the dark-field background required for fluorescent imaging, without the need for a thin-film interference filter. We validate the performance of this platform by imaging various fluorescent micro-objects in 2 colours (i.e., red and green) over a large field-of-view (FOV) of ~81 mm2 with a raw spatial resolution of ~20 μm. With additional digital processing of the captured cell-phone images, through the use of compressive sampling theory, we demonstrate ~2 fold improvement in our resolving power, achieving ~10 μm resolution without a trade-off in our FOV. Further, we also demonstrate darkfield imaging of non-fluorescent specimen using the same interface, where this time the scattered light from the objects is detected without the use of any filters. The capability of imaging a wide FOV would be exceedingly important to probe large sample volumes (e.g., >0.1 mL) of e.g., blood, urine, sputum or water, and for this end we also demonstrate fluorescent imaging of labeled white-blood cells from whole blood samples, as well as water-borne pathogenic protozoan parasites such as Giardia Lamblia cysts. Weighing only ~28 g (~1 ounce), this compact and cost-effective fluorescent imaging platform attached to a cell-phone could be quite useful especially for resource-limited settings, and might provide an important tool for wide-field imaging and quantification of various lab-on-a-chip assays developed for global health applications, such as monitoring of HIV+ patients for CD4 counts or viral load measurements. PMID:21063582

Self-assembly concepts in the formation of nanostructured particles using a liquid-phase synthesis method

NASA Astrophysics Data System (ADS)

Nandiyanto, Asep Bayu Dani

2016-02-01

When synthesizing particles using a liquid-phase synthesis method, reactant components show interaction with the reaction system itself. However, current reports described successful synthesis of material with only partial information on the component-component interaction and possible self-assembly mechanism occurring during the material synthesis process. Here, self-assembly concepts in the formation of nanostructured particles are presented. Influences of self-assembly parameters (i.e., surface charge, size, and concentration of components involving the reaction) on self-organized material fabrication are described. Because understanding the interaction of the component provides significant information in regard to practical uses, this report can be relevant to further material development and fabrication.

The permeability characteristics and interaction of main components from Si-Ni-San in a MDCK epithelial cell monolayer model.

PubMed

Chen, Ruonan; Shen, Chenlin; Xu, Qingqing; Liu, Yaru; Li, Bo; Huang, Cheng; Ma, Taotao; Meng, Xiaoming; Wu, Maomao; Li, Jun

2017-07-26

1. Si-Ni-San (SNS) possesses extensive therapeutic effects, however, the extent to which main components are absorbed and the mechanisms involved are controversial. 2. In this study, MDCK cell model was used to determine the permeability characteristics and interaction between the major components of Si-Ni-San, including saikosaponin a, paeoniflorin, naringin and glycyrrhizic acid. 3. The transport of the major components was concentration-dependent in both directions. Moreover, the transport of paeoniflorin, naringin and glycyrrhizic acid was significantly reduced at 4°C or in the presence of NaN3. Additionally, the efflux of paeoniflorin and naringin were apparently reduced in the presence of P-gp inhibitor verapamil. The transport of glycyrrhizic acid was clearly inhibited by the inhibitors of MRP2, indicating that MRP2 may be involved in the transport of glycyrrhizic acid. However, the results indicated that saikosaponin a was absorbed mainly by passive diffusion. Furthermore, the combined incubation of four major components had a powerful sorbefacient effect than a single drug used alone which may be regulated by tight junctions. 4. Taken together, our study provides useful information for pharmacological applications of Si-Ni-San and offers new insights into this ancient decoction for further researches, especially in drug synergism.

A regulon conserved in monocot and dicot plants defines a functional module in antifungal plant immunity

PubMed Central

Humphry, Matt; Bednarek, Paweł; Kemmerling, Birgit; Koh, Serry; Stein, Mónica; Göbel, Ulrike; Stüber, Kurt; Piślewska-Bednarek, Mariola; Loraine, Ann; Schulze-Lefert, Paul; Somerville, Shauna; Panstruga, Ralph

2010-01-01

At least two components that modulate plant resistance against the fungal powdery mildew disease are ancient and have been conserved since the time of the monocot–dicot split (≈200 Mya). These components are the seven transmembrane domain containing MLO/MLO2 protein and the syntaxin ROR2/PEN1, which act antagonistically and have been identified in the monocot barley (Hordeum vulgare) and the dicot Arabidopsis thaliana, respectively. Additionally, syntaxin-interacting N-ethylmaleimide sensitive factor adaptor protein receptor proteins (VAMP721/722 and SNAP33/34) as well as a myrosinase (PEN2) and an ABC transporter (PEN3) contribute to antifungal resistance in both barley and/or Arabidopsis. Here, we show that these genetically defined defense components share a similar set of coexpressed genes in the two plant species, comprising a statistically significant overrepresentation of gene products involved in regulation of transcription, posttranslational modification, and signaling. Most of the coexpressed Arabidopsis genes possess a common cis-regulatory element that may dictate their coordinated expression. We exploited gene coexpression to uncover numerous components in Arabidopsis involved in antifungal defense. Together, our data provide evidence for an evolutionarily conserved regulon composed of core components and clade/species-specific innovations that functions as a module in plant innate immunity. PMID:21098265

Silencing Nicotiana attenuata LHY and ZTL alters circadian rhythms in flowers.

PubMed

Yon, Felipe; Joo, Youngsung; Cortés Llorca, Lucas; Rothe, Eva; Baldwin, Ian T; Kim, Sang-Gyu

2016-02-01

The rhythmic opening/closing and volatile emissions of flowers are known to attract pollinators at specific times. That these rhythms are maintained under constant light or dark conditions suggests a circadian clock involvement. Although a forward and reverse genetic approach has led to the identification of core circadian clock components in Arabidopsis thaliana, the involvement of these clock components in floral rhythms has remained untested, probably because of the weak diurnal rhythms in A. thaliana flowers. Here, we addressed the role of these core clock components in the flowers of the wild tobacco Nicotiana attenuata, whose flowers open at night, emit benzyl acetone (BA) scents and move vertically through a 140° arc. We first measured N. attenuata floral rhythms under constant light conditions. The results suggest that the circadian clock controls flower opening, BA emission and pedicel movement, but not flower closing. We generated transgenic N. attenuata lines silenced in the homologous genes of Arabidopsis LATE ELONGATED HYPOCOTYL (LHY) and ZEITLUPE (ZTL), which are known to be core clock components. Silencing NaLHY and NaZTL strongly altered floral rhythms in different ways, indicating that conserved clock components in N. attenuata coordinate these floral rhythms. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Modelling robot construction systems

NASA Technical Reports Server (NTRS)

Grasso, Chris

1990-01-01

TROTER's are small, inexpensive robots that can work together to accomplish sophisticated construction tasks. To understand the issues involved in designing and operating a team of TROTER's, the robots and their components are being modeled. A TROTER system that features standardized component behavior is introduced. An object-oriented model implemented in the Smalltalk programming language is described and the advantages of the object-oriented approach for simulating robot and component interactions are discussed. The presentation includes preliminary results and a discussion of outstanding issues.

NDE of cylindrically symmetric components with piezofilm transducers

NASA Astrophysics Data System (ADS)

Hsu, David K.; Zhang, Zhong

PVDF polymer film transducers are presently shown to exhibit the flexibility and comformability required for inspection of components with curved surfaces. Although these transducers are less efficient than rigid ceramic ones, and are less accurately matched to the acoustic impedance of metals as well as ceramic transducers, their advantages are presently shown to outweigh their disadvantages in some applications involving tube and rod shaped components. Interface measurements of a Zr/Zircalloy-2 tube allowed the detailed evaluation of weakly reflecting interfaces.

Component research for future propulsion systems

NASA Technical Reports Server (NTRS)

Walker, C. L.; Weden, G. J.; Zuk, J.

1981-01-01

Factors affecting the helicopter market are reviewed. The trade-offs involving acquisition cost, mission reliability, and life cycle cost are reviewed, including civil and military aspects. The potential for advanced vehicle configurations with substantial improvements in energy efficiency, operating economics, and characteristics to satisfy the demands of the future market are identified. Advanced propulsion systems required to support these vehicle configurations are discussed, as well as the component technology for the engine systems. Considerations for selection of components in areas of economics and efficiency are presented.

Components of Environmental Literacy in Elementary Science Education Curriculum in Bulgaria and Turkey

ERIC Educational Resources Information Center

Erdogan, Mehmet; Kostova, Zdravka; Marcinkowski, Thomas

2009-01-01

The purpose of this study was to analyze the extent to which science education objectives in elementary schools addressed to the six basic components of environmental literacy (EL), and how this attention differed from Bulgaria to Turkey. The main method in the study involved comparative content analysis of these objectives. The courses sampled…

Delivering Speech and Language Therapy to Head Start Children: A Template for Inclusion through Systemic Change.

ERIC Educational Resources Information Center

Strobridge, Michele

This practicum was designed to provide speech and language therapy to children identified as speech and language impaired, in a Head Start classroom with typically developing peers. The practicum involved amending Head Start component plans, discussing inclusion issues at four education component meetings, conducting an interagency meeting with…

Do Adults Show an Effect of Delayed First Language Acquisition When Calculating Scalar Implicatures?

ERIC Educational Resources Information Center

Davidson, Kathryn; Mayberry, Rachel I.

2015-01-01

Language acquisition involves learning not only grammatical rules and a lexicon but also what people are intending to convey with their utterances: the semantic/pragmatic component of language. In this article we separate the contributions of linguistic development and cognitive maturity to the acquisition of the semantic/pragmatic component of…

Involving Teachers in Reducing Children's Media Risks

ERIC Educational Resources Information Center

Stiller, Anja; Schwendemann, Hanna; Bleckmann, Paula; Bitzer, Eva-Maria; Mößle, Thomas

2018-01-01

Purpose: The purpose of this paper is twofold: first, to introduce MEDIA PROTECT, a multi-modal intervention for parents and teachers with six components preventing problematic, and in the long run addictive, use of screen media by children; second, to present results of a formative evaluation of the teacher training, an important component of the…

Microstructure-Evolution and Reliability Assessment Tool for Lead-Free Component Insertion in Army Electronics

DTIC Science & Technology

2008-10-01

provide adequate means for thermal heat dissipation and cooling. Thus electronic packaging has four main functions [1]: • Signal distribution which... dissipation , involving structural and materials consideration. • Mechanical, chemical and electromagnetic protection of components and... nature when compared to phenomenological models. Microelectronic packaging industry spends typically several months building and reliability

Application of molecular genetic tools to studies of forest pathosystems [Chapter 2

Treesearch

Mee-Sook Kim; Ned B. Klopfenstein; Richard C. Hamelin

2005-01-01

The use of molecular genetics in forest pathology has greatly increased over the past 10 years. For the most part, molecular genetic tools were initially developed to focus on individual components (e.g., pathogen, host) of forest pathosystems. As part of broader forest ecosystem complexes, forest pathosystems involve dynamic interactions among living components (e.g...

Energy efficient engine component development and integration program

NASA Technical Reports Server (NTRS)

1980-01-01

The design of an energy efficient commercial turbofan engine is examined with emphasis on lower fuel consumption and operating costs. Propulsion system performance, emission standards, and noise reduction are also investigated. A detailed design analysis of the engine/aircraft configuration, engine components, and core engine is presented along with an evaluation of the technology and testing involved.

Telling the Technology Story: PR Strategies for School Leaders. Backgrounder Brief. CoSN Essential Leadership Skills Series

ERIC Educational Resources Information Center

Consortium for School Networking (NJ1), 2006

2006-01-01

This Backgrounder Brief is an executive summary of "Telling the Technology Story: PR Strategies for School Leaders," a component of the Consortium for School Networking (CoSN) Essential Leadership Skills Series. Public relations is a critical component of a district's successful technology implementation--and it involves communicating on an…