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1

Mechanisms of adaptation in the intestinal parasite Giardia lamblia.  

Science.gov (United States)

Giardia lamblia, a parasite of humans, is a major source of waterborne diarrhoeal disease. Giardia is also an excellent system to study basic biochemical processes because it is a single-celled eukaryote with a small genome and its entire life cycle can be replicated in vitro. Giardia trophozoites undergo fundamental changes to survive outside the intestine of their host by differentiating into infective cysts. Encystation entails the synthesis, processing, transport, secretion and extracellular assembly of cyst wall components. To survive within the intestine, Giardia undergoes antigenic variation, a process by which the parasite continuously switches its major surface molecules, allowing the parasite to evade the host's immune response and produce chronic and recurrent infections. The objective of the present chapter is to provide a better understanding of the molecular mechanisms involved in adaptation and differentiation in Giardia, with a particular focus on the process of encystation and antigenic variation of this interesting micro-organism. PMID:22023449

Lujan, Hugo D

2011-01-01

2

Unusual ribosomal RNA of the intestinal parasite Giardia lamblia.  

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The anaerobic protozoan Giardia lamblia is a common intestinal parasite in humans, but is poorly defined at molecular and phylogenetic levels. We report here a structural characterization of the ribosomal RNA (rRNA) and rRNA genes of G. lamblia. Gel electrophoresis under native or non-denaturing conditions identified two high molecular weight rRNA species corresponding to the 16-18S and 23-28S rRNAs. Surprisingly, both species (1300 and 2300 nucleotides long, respectively) were considerably s...

Edlind, T. D.; Chakraborty, P. R.

1987-01-01

3

Cholesterol starvation induces differentiation of the intestinal parasite Giardia lamblia.  

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Giardia lamblia, like most human intestinal parasitic protozoa, sustains fundamental morphological and biochemical changes to survive outside the small intestine of its mammalian host by differentiating into an infective cyst. However, the stimulus that triggers this differentiation remains totally undefined. In this work, we demonstrate the induction of cyst formation in vitro when trophozoites are starved for cholesterol. Expression of cyst wall proteins was detected within encystation-spec...

Luja?n, H. D.; Mowatt, M. R.; Byrd, L. G.; Nash, T. E.

1996-01-01

4

Genomic minimalism in the early diverging intestinal parasite Giardia lamblia.  

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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. PMID:17901334

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

5

Unusual ribosomal RNA of the intestinal parasite Giardia lamblia.  

Science.gov (United States)

The anaerobic protozoan Giardia lamblia is a common intestinal parasite in humans, but is poorly defined at molecular and phylogenetic levels. We report here a structural characterization of the ribosomal RNA (rRNA) and rRNA genes of G. lamblia. Gel electrophoresis under native or non-denaturing conditions identified two high molecular weight rRNA species corresponding to the 16-18S and 23-28S rRNAs. Surprisingly, both species (1300 and 2300 nucleotides long, respectively) were considerably shorter than their counterparts from other protozoa (typically 1800 and 3400 nucleotides), and from bacteria as well (typically 1540 and 2900 nucleotides long). Denaturing polyacrylamide gel electrophoresis identified a major low molecular RNA of 127 nucleotides and several minor species, but no molecules with the typical lengths of 5.8S (160 nucleotides) and 5S (120 nucleotides) rRNA. The G. lamblia 1300, 2300, and 127 nucleotide RNAs are encoded within a 5.6 kilobase pair tandemly repeated DNA, as shown by Southern blot analysis and DNA cloning. Thus, the rRNA operon of this eukaryotic organism can be no longer than a typical bacterial operon. Sequence analysis identified the 127 nucleotide RNA as homologous to 5.8S RNA, but comparisons to archaebacterial rRNA suggest that Giardia derived from an early branch in eukaryotic evolution. PMID:3118329

Edlind, T D; Chakraborty, P R

1987-10-12

6

Cholesterol starvation induces differentiation of the intestinal parasite Giardia lamblia.  

Science.gov (United States)

Giardia lamblia, like most human intestinal parasitic protozoa, sustains fundamental morphological and biochemical changes to survive outside the small intestine of its mammalian host by differentiating into an infective cyst. However, the stimulus that triggers this differentiation remains totally undefined. In this work, we demonstrate the induction of cyst formation in vitro when trophozoites are starved for cholesterol. Expression of cyst wall proteins was detected within encystation-specific secretory vesicles 90 min after the cells were placed in lipoprotein-deficient TYI-S-33 medium. Four cloned lines derived from two independent Giardia isolates were tested, and all formed cysts similarly. Addition of cholesterol, low density or very low density lipoproteins to the lipoprotein-deficient culture medium, inhibited the expression of cyst wall proteins, the generation of encystation-specific vesicles, and cyst wall biogenesis. In contrast, high density lipoproteins, phospholipids, bile salts, or fatty acids had little or no effect. These results indicate that cholesterol starvation is necessary and sufficient for the stimulation of Giardia encystation in vitro and, likely, in the intestine of mammalian hosts. PMID:8755526

Luján, H D; Mowatt, M R; Byrd, L G; Nash, T E

1996-07-23

7

??????: Giardia lamblia virus  

Full Text Available Viruses Totiviridae Giardia lamblia virus GLV (acronym) NCBI 29255 Giardia lamblia virus (scient ific name) NCBI 29255 Giardia lamblia virus. (misspelling) NCBI 29255 Giardia vir us sp. (synonym) NCBI 29255 giardia virus GLV (misnomer) NCBI 29255

8

Visualization of chromosomes in the binucleate intestinal parasite Giardia lamblia.  

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Mitosis of Giardia lamblia is a complex and rapid event that is poorly understood at the cellular and molecular levels. Therefore, we conducted this study to determine (1) whether the two nuclei have similar or different chromosomes, (2) the number of chromosomes of G. lamblia, and (3) the morphology and karyotype of the chromosomes. Trophozoites of the C2 and WB strains of G. lamblia were grown in modified TYI-S-33 medium at 37°C. The trophozoites were collected, and sample slides were prepared for conventional light and scanning electron microscopy. Light microscopy revealed five pairs of chromosomes. The chromosomes were approximately 0.64-0.94 ?m long with a short rod-like shape and were usually arranged in pairs. Scanning electron microscopy yielded similar findings, and 10 chromosomes could be seen in each nucleus. Thus, the chromosome number of G. lamblia is 2n = 10. Chromosomes in pair 1 are submetacentric chromosomes, while pairs 2-5 are telocentric chromosomes. The present study shows that G. lamblia trophozoites have typical condensed chromosomes during mitosis and contains five pairs of chromosomes. The karyogram shows good fit to the formula 2n = 10 = 2sm + 8t revealed by scanning electron microscopy. PMID:21526404

Shen, Hai E; Cao, Lei; Li, Ji; Tian, Xi Feng; Yang, Zhi Hong; Wang, Yue; Tian, Yu Na; Lu, Si Qi

2011-11-01

9

Impaired Parasite Attachment as Fitness Cost of Metronidazole Resistance in Giardia lamblia?  

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Infections with the diarrheagenic protozoan pathogen Giardia lamblia are most commonly treated with metronidazole (Mz). Treatment failures with Mz occur in 10 to 20% of cases and Mz resistance develops in the laboratory, yet clinically, Mz-resistant (Mzr) G. lamblia has rarely been isolated from patients. To understand why clinical Mzr isolates are rare, we questioned whether Mz resistance entails fitness costs to the parasite. Our studies employed several newly generated and established isog...

Tejman-yarden, Noa; Millman, Maya; Lauwaet, Tineke; Davids, Barbara J.; Gillin, Frances D.; Dunn, Linda; Upcroft, Jacqueline A.; Miyamoto, Yukiko; Eckmann, Lars

2011-01-01

10

Transcriptional Analysis of Three Major Putative Phosphatidylinositol Kinase Genes in a Parasitic Protozoan, Giardia lamblia  

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The current investigation evaluates the expression of phosphatidylinositol kinase (PIK) genes in the parasitic protozoan, Giardia lamblia. The G. lamblia Genome Database revealed the presence of two putative phosphatidylinositol-3-kinase (gPI3K) and one phosphatidylinositol-4-kinase (gPI4K) genes resembling the catalytic subunit of eukaryotic PIKs. Primers, designed to amplify mRNA of these three genes, were used to measure transcription by quantitative reverse-transcriptase polymerase chain ...

Hernandez, Yunuen; Zamora, Gus; Ray, Suparna; Chapoy, Jaime; Chavez, Edna; Valvarde, Robert; Williams, Ebonye; Aley, Stephen B.; Das, Siddhartha

2007-01-01

11

Nitroimidazole drugs vary in their mode of action in the human parasite Giardia lamblia.  

Science.gov (United States)

Giardia lamblia (syn. duodenalis, intestinalis) is a globally occurring micro-aerophilic human parasite that causes gastrointestinal disease. Standard treatment of G. lamblia infections is based on the 5-nitroimidazole drugs metronidazole and tinidazole. In two other micro-aerophilic parasites, Entamoeba histolytica and Trichomonas vaginalis, 5-nitroimidazole drugs bind to proteins involved in the thioredoxin-mediated redox network and disrupt the redox equilibrium by inhibiting thioredoxin reductase and depleting intracellular thiol pools. The major aim of this study was to assess whether nitroimidazoles exert a similar toxic effect on G. lamblia physiology. The 5-nitroimidazoles metronidazole and tinidazole were found to bind to the same subset of proteins including thioredoxin reductase. However, in contrast to E. histolytica and T. vaginalis, none of the other proteins bound are candidates for being involved in the thioredoxin-mediated redox network. Translation elongation factor EF-1?, an essential factor in protein synthesis, was widely degraded upon treatment with 5-nitroimidazoles. 2-Nitroimidazole (azomycin) and the 5-nitroimidazole ronidazole did not bind to any G. lamblia proteins, which is in contrast to previous findings in E. histolytica and T. vaginalis. All nitroimidazoles tested reduced intracellular thiol pools in G. lamblia, but metronidazole, also in contrast to the situation in the other two parasites, had the slightest effect. Taken together, our results suggest that nitroimidazole drugs affect G. lamblia in a fundamentally different way than E. histolytica and T. vaginalis. PMID:24533278

Leitsch, David; Schlosser, Sarah; Burgess, Anita; Duchêne, Michael

2012-12-01

12

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

Science.gov (United States)

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. PMID:11162464

Garat, B; Musto, H

2000-12-29

13

Growth inhibition of the intestinal parasite Giardia lamblia by a dietary lectin is associated with arrest of the cell cycle.  

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Giardia lamblia, a cause of diarrheal disease throughout the world, is a protozoan parasite that thrives in the small intestine. It is shown here that wheat germ agglutinin (WGA), a naturally occurring lectin widely consumed in normal human diets, reversibly inhibits the growth of G. lamblia trophozoites in vitro, and reduces infection by G. muris in the adult mouse model of giardiasis. The inhibitory effect was dose related, not associated with cytotoxicity and reversed by N-acetyl-D-glucosa...

Ortega-barria, E.; Ward, H. D.; Keusch, G. T.; Pereira, M. E.

1994-01-01

14

Calcium transport and catabolism of adenosine triphosphate in the protozoan parasite Giardia lamblia.  

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1. Calcium uptake by washed trophozoites of Giardia lamblia was dependent on inorganic orthophosphate and stimulated by glucose. Uptake was both rapid and substantial: 224 +/- 73 nmoles Ca2+/mg protein/min. 2. Known inhibitors of Ca2+ uptake in mammalian cells also impeded Ca2+ influx into G. lamblia. 3. The inhibitor studies indicated that Ca2+ transport in G. lamblia was an active process. Energy for such a process could be provided by the action of ATPases. 4. Two types of ATPases were found in the parasite; one, a membrane-associated enzyme activated by Ca2+; the other, a soluble, cytosolic enzyme activated by Mg2+. 5. These enzymes differed not only in their intracellular distribution and divalent cation requirements, but also in their sensitivity to calmodulin antagonists. The particulate enzyme was sensitive to these inhibitors whereas the soluble ATPase was not. 6. Our data indicate that Ca2+ transport in G. lamblia is mediated by a membrane-bound, calmodulin-regulated, Ca2+-ATPase. PMID:2973967

Munoz, M L; Claggett, C E; Weinbach, E C

1988-01-01

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Pyrimidine salvage in Giardia lamblia  

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We have found that the anaerobic protozoan parasite Giardia lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate, and aspartate into the pyrimidine nucleotide pool. Results from high performance liquid chromatography of pyrimidine and pyrimidine nucleoside pulse-labeled nucleotide pools and enzyme assays suggest that the parasite satisfies its pyrimidine nucleotide needs predominantly through salvage of uracil by a cytoplasmic ur...

1985-01-01

16

Clathrin-dependent pathways and the cytoskeleton network are involved in ceramide endocytosis by a parasitic protozoan, Giardia lamblia  

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Although identified as an early-diverged protozoan, Giardia lamblia shares many similarities with higher eukaryotic cells, including an internal membrane system and cytoskeleton, as well as secretory pathways. However, unlike many other eukaryotes, Giardia does not synthesize lipids de novo, but rather depends on exogenous sources for both energy production and organelle or membrane biogenesis. It is not known how lipid molecules are taken up by this parasite and if endocytic pathways are inv...

Hernandez, Yunuen; Castillo, Cynthia; Roychowdhury, Sukla; Hehl, Adrian; Aley, Stephen B.; Das, Siddhartha

2007-01-01

17

Impaired parasite attachment as fitness cost of metronidazole resistance in Giardia lamblia.  

Science.gov (United States)

Infections with the diarrheagenic protozoan pathogen Giardia lamblia are most commonly treated with metronidazole (Mz). Treatment failures with Mz occur in 10 to 20% of cases and Mz resistance develops in the laboratory, yet clinically, Mz-resistant (Mz(r)) G. lamblia has rarely been isolated from patients. To understand why clinical Mz(r) isolates are rare, we questioned whether Mz resistance entails fitness costs to the parasite. Our studies employed several newly generated and established isogenic Mz(r) cell lines with stable, high-level resistance to Mz and significant cross-resistance to tinidazole, nitazoxanide, and furazolidone. Oral infection of suckling mice revealed that three of five Mz(r) cell lines could not establish infection, while two Mz(r) cell lines infected pups, albeit with reduced efficiencies. Failure to colonize resulted from a diminished capacity of the parasite to attach to the intestinal mucosa in vivo and to epithelial cells and plastic surfaces in vitro. The attachment defect was related to impaired glucose metabolism, since the noninfectious Mz(r) lines consumed less glucose, and glucose promoted ATP-independent parasite attachment in the parental lines. Thus, resistance of Giardia to Mz is accompanied by a glucose metabolism-related attachment defect that can interfere with colonization of the host. Because glucose-metabolizing pathways are important for activation of the prodrug Mz, it follows that a fitness trade-off exists between diminished Mz activation and reduced infectivity, which may explain the observed paucity of clinical Mz(r) isolates of Giardia. However, the data also caution that some forms of Mz resistance do not markedly interfere with in vivo infectivity. PMID:21825286

Tejman-Yarden, Noa; Millman, Maya; Lauwaet, Tineke; Davids, Barbara J; Gillin, Frances D; Dunn, Linda; Upcroft, Jacqueline A; Miyamoto, Yukiko; Eckmann, Lars

2011-10-01

18

Insulin-like growth factors stimulate growth and L-cysteine uptake by the intestinal parasite Giardia lamblia.  

Science.gov (United States)

Giardia lamblia, a parasitic protozoan responsible for diarrhea and malabsorption in humans, grows axenically only in media that contain serum and a high concentration of L-cysteine. During our attempts to grow Giardia in the absence of serum, we found that: (a) human insulin-like growth factors (especially IGF-II), but not insulin, promote the growth and L-cysteine uptake by G. lamblia trophozoites; (b) the growth stimulation was inhibited by alpha IR3, an anti-type 1 IGF receptor monoclonal antibody, but an anti-type 2 IGF receptor antibody had no effect; and (c) IGFs act on Giardia through a type 1 IGF receptor-like protein, which can bind IGF-II with higher affinity than IGF-I, and most likely possesses intrinsic phosphotyrosine kinase activity. PMID:8175729

Luján, H D; Mowatt, M R; Helman, L J; Nash, T E

1994-05-01

19

Giardia lamblia infections in adult mice.  

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An adult mouse-Giardia lamblia model was developed and used to study host-parasite interactions, including antigenic variation. The H7/1 clone of isolate GS infected mice consistently and produced infections in 14 mouse strains tested. Infection patterns were mouse strain and Giardia isolate dependent. Antigenic variation occurred in immunocompetent mice but not in mice with severe combined immunodeficiency.

Byrd, L. G.; Conrad, J. T.; Nash, T. E.

1994-01-01

20

Codon usage in Giardia lamblia.  

Science.gov (United States)

A codon usage table for the intestinal parasite Giardia lamblia was generated by analysis of the nucleotide sequences of eight genes comprising 3,135 codons. Codon usage revealed a biased use of synonymous codons with a preference for NNC codons (42.1%). The codon usage of G. lamblia more closely resembles that of the prokaryote Halobacterium halobium (correlation coefficient r = 0.73) rather than that of other eukaryotic protozoans, i.e. Trypanosoma brucei (r = 0.434) and Plasmodium falciparum (r = -0.31). These observations are consistent with the view that G. lamblia represents the first line of descent from the ancestral cells that first took on eukaryotic features. PMID:1522548

Char, S; Farthing, M J

1992-01-01

 
 
 
 
21

Diagnosis of Giardia lamblia infections by detection of parasite-specific antigens.  

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Antigen detection methods may facilitate diagnosis of Giardia lamblia in stool specimens. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and immunoblotting, G. lamblia cysts and trophozoites share several antigens, especially in the 65-kilodalton and 30- to 34-kilodalton regions. By using blind methods, we compared results obtained by counterimmunoelectrophoresis using cyst-immune rabbit serum and by enzyme-linked immunosorbent assay (ELISA) using trophozo...

Janoff, E. N.; Craft, J. C.; Pickering, L. K.; Novotny, T.; Blaser, M. J.; Knisley, C. V.; Reller, L. B.

1989-01-01

22

X-ray structure and characterization of carbamate kinase from the human parasite Giardia lamblia.  

Science.gov (United States)

Carbamate kinase catalyzes the reversible conversion of carbamoyl phosphate and ADP to ATP and ammonium carbamate, which is hydrolyzed to ammonia and carbonate. The three-dimensional structure of carbamate kinase from the human parasite Giardia lamblia (glCK) has been determined at 3 A resolution. The crystals belonged to the monoclinic space group P2(1), with unit-cell parameters a = 69.77, b = 85.41, c = 102.1 A, beta = 106.8 degrees . The structure was refined to a final R factor of 0.227. The essentiality of glCK together with its absence in humans makes the enzyme an attractive candidate for anti-Giardia drug development. Steady-state kinetic rate constants have been determined. The k(cat) for ATP formation is 319 +/- 9 s(-1). The K(m) values for carbamoyl phosphate and ADP are 85 +/- 6 and 70 +/- 5 microM, respectively. The structure suggests that three invariant lysine residues (Lys131, Lys216 and Lys278) may be involved in the binding of substrates and phosphoryl transfer. The structure of glCK reveals that a glycerol molecule binds in the likely carbamoyl phosphate-binding site. PMID:20383005

Galkin, Andrey; Kulakova, Liudmila; Wu, Rui; Nash, Theodore E; Dunaway-Mariano, Debra; Herzberg, Osnat

2010-04-01

23

Tonic Shock Induces Detachment of Giardia lamblia  

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The single-celled organism Giardia lamblia colonizes the small intestine of a wide variety of hosts, including humans. Giardiasis infections can cause severe gastrointestinal symptoms and pose a major health concern in the developing world. Giardia are known to attach robustly to a variety of surfaces, but the conditions that influence this attachment are not known. In this study, we examined the behavior of attached Giardia parasites exposed to rapid changes in solution properties, like thos...

Hansen, Wendy R.; Fletcher, Daniel A.

2008-01-01

24

Active and passive mechanisms drive secretory granule biogenesis during differentiation of the intestinal parasite Giardia lamblia.  

Science.gov (United States)

The parasitic protozoan Giardia lamblia undergoes important changes to survive outside the intestine of its host by differentiating into infective cysts. During encystation, three cyst wall proteins (CWPs) are specifically expressed and concentrated within encystation-specific secretory vesicles (ESVs). ESVs are electron-dense secretory granules that transport CWPs before exocytosis and extracellular polymerization into a rigid cyst wall. Because secretory granules form at the trans-Golgi in higher eukaryotes and because Giardia lacks an identifiable Golgi apparatus, the aim of this work was to investigate the molecular basis of secretory granule formation in Giardia by examining the role of CWPs in this process. Although CWP1, CWP2, and CWP3 are structurally similar in their 26-kDa leucine-rich overlapping region, CWP2 is distinguished by the presence of a 13-kDa C-terminal basic extension. In non-encysting trophozoites, expression of different CWP chimeras showed that the CWP2 basic extension is necessary for biogenesis of ESVs, which occurs in a compartment derived from the endoplasmic reticulum. Nevertheless, the CWP2 basic extension per se is insufficient to trigger ESV formation, indicating that other domains in CWPs are also required. We found that CWP2 is a key regulator of ESV formation by acting as an aggregation factor for CWP1 and CWP3 through interactions mediated by its conserved region. CWP2 also acts as a ligand for sorting via its C-terminal basic extension. These findings show that granule biogenesis requires complex interactions among granule components and membrane receptors. PMID:16611634

Gottig, Natalia; Elías, Eliana V; Quiroga, Rodrigo; Nores, María J; Solari, Alberto J; Touz, María C; Luján, Hugo D

2006-06-30

25

Pyrimidine salvage in Giardia lamblia.  

Science.gov (United States)

We have found that the anaerobic protozoan parasite Giardia lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate, and aspartate into the pyrimidine nucleotide pool. Results from high performance liquid chromatography of pyrimidine and pyrimidine nucleoside pulse-labeled nucleotide pools and enzyme assays suggest that the parasite satisfies its pyrimidine nucleotide needs predominantly through salvage of uracil by a cytoplasmic uracil phosphoribosyltransferase. Exogenous uridine and cytidine are primarily converted to uracil by the action of uridine hydrolase and cytidine deaminase before incorporation into nucleotide pools. Direct salvage of cytosine occurs to a relatively limited extent via cytosine phosphoribosyltransferase. G. lamblia relies on salvage of exogenous thymidine for ribosylthymine monophosphate (TMP) synthesis, accomplished primarily through the action of a 100,000 g-pelletable thymidine phosphotransferase. PMID:3973534

Aldritt, S M; Tien, P; Wang, C C

1985-03-01

26

X-ray structure and characterization of carbamate kinase from the human parasite Giardia lamblia  

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The three-dimensional structure of carbamate kinase from the human parasite G. lamblia has been determined at 3?Å resolution. Steady-state kinetic parameters have been determined and dsRNA-silencing experiments indicate that the enzyme is essential for the survival of G. lamblia.

Galkin, Andrey; Kulakova, Liudmila; Wu, Rui; Nash, Theodore E.; Dunaway-mariano, Debra; Herzberg, Osnat

2010-01-01

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Experimental Infections of Neonatal Mice with Cysts of Giardia lamblia Clone GS/M-83-H7 Are Associated with an Antigenic Reset of the Parasite  

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Transmission of the protozoan parasite Giardia lamblia from one to another host individuum occurs through peroral ingestion of cysts which, following excystation in the small intestine, release two trophozoites each. Many studies have focused on the major surface antigen, VSP (for variant surface protein), which is responsible for the antigenic variability of the parasite. By using trophozoites of G. lamblia clone GS/M-83-H7 (expressing VSP H7) and the neonatal mouse model for experimental in...

Von Allmen, N.; Bienz, M.; Hemphill, A.; Mu?ller, N.

2004-01-01

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Growth inhibition of the intestinal parasite Giardia lamblia by a dietary lectin is associated with arrest of the cell cycle.  

Science.gov (United States)

Giardia lamblia, a cause of diarrheal disease throughout the world, is a protozoan parasite that thrives in the small intestine. It is shown here that wheat germ agglutinin (WGA), a naturally occurring lectin widely consumed in normal human diets, reversibly inhibits the growth of G. lamblia trophozoites in vitro, and reduces infection by G. muris in the adult mouse model of giardiasis. The inhibitory effect was dose related, not associated with cytotoxicity and reversed by N-acetyl-D-glucosamine in accordance with the known specificity of the lectin and in agreement with the presence of GlcNAc residues on the surface membrane of G. lamblia trophozoites. Cell cycle analysis revealed that parasites grown in the presence of WGA are arrested in the G2/M phase, providing an explanation for the lectin-induced inhibition of cell proliferation. Comparison of electrophoretic profiles by lectin blot analysis revealed both glycoprotein induction and suppression in growth-arrested organisms. Our findings raise the possibility that blocking trophozoite growth with naturally occurring dietary lectins may influence the course of giardiasis. In addition, the study of cell cycle arrest by WGA may provide a model to study the regulation of cell division in lower eukaryotes. PMID:7989583

Ortega-Barria, E; Ward, H D; Keusch, G T; Pereira, M E

1994-12-01

29

The proteome landscape of Giardia lamblia encystation  

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Giardia lamblia is an intestinal protozoan parasite required to survive in the environment in order to be transmitted to a new host. To ensure parasite survival, flagellated trophozoites colonizing the small intestine differentiate into non-motile environmentally-resistant cysts which are then shed in the environment. This cell differentiation process called encystation is characterized by significant morphological remodeling which includes secretion of large amounts of cyst wall material. Al...

Faso, Carmen; Bischof, Sylvain; Hehl, Adrian B.

2013-01-01

30

Lectin binding by Giardia lamblia.  

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Surface carbohydrates of Giardia lamblia were examined using six plant lectins chosen because of their specificity for major carbohydrates moieties. The binding to axenically grown G. lamblia trophozoites was assessed in both a quantitative microagglutination assay and a fluorescence assay. Of the six lectins tested, wheat germ agglutinin (WGA) agglutinated the highest percentage (22.9 +/- 3.7%) of live trophozoites, and fluorescein-labeled WGA (100 micrograms/ml) bound to 98 +/- 5% of them. ...

1981-01-01

31

Identification of scaffold/Matrix Attachment (S/MAR like DNA element from the gastrointestinal protozoan parasite Giardia lamblia  

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Full Text Available Abstract Background Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene organization and regulation of gene expression, they have not been reported in protists like Giardia. Several tools have been discovered and formulated to predict S/MARs from a genome of a higher eukaryote which take into account a number of features. However, the lack of a definitive consensus sequence in S/MARs and the randomness of the protozoan genome in general, make it a challenge to predict and identify such sequences from protists. Results Here, we have analysed the Giardia genome for the probable S/MARs predicted by the available computational tools; and then shown these sequences to be physically associated with the nuclear matrix. Our study also reflects that while no single computational tool is competent to predict such complex elements from protist genomes, a combination of tools followed by experimental verification is the only way to confirm the presence of these elements from these organisms. Conclusion This is the first report of S/MAR elements from the protozoan parasite Giardia lamblia. This initial work is expected to lay a framework for future studies relating to genome organization as well as gene regulatory elements in this parasite.

Gautam Pennathur

2010-06-01

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Giardia lamblia low-density lipoprotein receptor-related protein is involved in selective lipoprotein endocytosis and parasite replication  

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As Giardia lamblia is unable to synthesize cholesterol de novo, this steroid might be obtained from the host’s intestinal milieu by endocytosis of lipoproteins. In this work, we identified a putative Giardia lamblia low-density lipoprotein receptor-related proteins (GlLRP), a type-I membrane protein, which shares the substrate-N-terminal binding domain and a FXNPXY-type endocytic motif with human LRPs. Expression of tagged-GlLRP showed that it was localized predominantly in the endoplasmic ...

Rivero, Maria R.; Miras, Silvana L.; Quiroga, Rodrigo; Ro?polo, Andrea S.; Touz, Maria C.

2011-01-01

33

Evaluation of the Triage Micro Parasite Panel for Detection of Giardia lamblia, Entamoeba histolytica/Entamoeba dispar, and Cryptosporidium parvum in Patient Stool Specimens  

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A study comparing the Triage Micro Parasite Panel (Biosite Diagnostics, Inc., San Diego, Calif.) to conventional O&P examination (O&P) was performed using patient fecal specimens. Five hundred twenty-three stool samples were compared. Nineteen specimens were found to be positive by Triage, and 29 were found to be positive by O&P. Seven specimens were positive for Giardia lamblia, four were positive for Entamoeba histolytica/E. dispar, and three were positive for Cryptosporidium parvum as dete...

Sharp, Susan E.; Suarez, Clarisa A.; Duran, Yolanda; Poppiti, Robert J.

2001-01-01

34

Detection of Giardia lamblia, Entamoeba histolytica/Entamoeba dispar, and Cryptosporidium parvum Antigens in Human Fecal Specimens Using the Triage Parasite Panel Enzyme Immunoassay  

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The Triage parasite panel (BIOSITE Diagnostics, San Diego, Calif.) is a new qualitative enzyme immunoassay (EIA) panel for the detection of Giardia lamblia, Entamoeba histolytica/E. dispar, and Cryptosporidium parvum in fresh or fresh, frozen, unfixed human fecal specimens. By using specific antibodies, antigens specific for these organisms are captured and immobilized on a membrane. Panel performance was evaluated with known positive and negative stool specimens (a total of 444 specimens) th...

Garcia, Lynne S.; Shimizu, Robyn Y.; Bernard, Caroline N.

2000-01-01

35

[Histocompatibility antigens and Giardia lamblia parasitosis].  

Science.gov (United States)

A study was made of the HLA in 41 children between the ages of 4 and 13 years, with the parasite Giardia lamblia, of ages between 4 and 13 years. The different histocompatibility antigens were compared in relationship to the clinical and analytical aspects of the patients. Individuals with HLA A1 and/or blood group A have a greater probability of contracting this parasite. Other relationships found were HLA A19 and vomiting. HLA A9 and abdominal pain and HLA B7 with alterations in the gastrointestinal mucous. PMID:1543292

de Manueles Jiménez, J; Martín Ruano, A; Martín Sanz, A J; Martín Ruano, J; Sánchez Calvín, M T

1992-01-01

36

Attachment of Giardia lamblia to rat intestinal epithelial cells.  

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The human enteric protozoan, Giardia lamblia, has surface membrane lectin activity which mediates parasite adherence to erythrocytes. To determine whether an intestinal binding site exists for this lectin we have studied the interaction in vitro between axenically cultured Giardia trophozoites and isolated rat intestinal epithelial cells. Scanning electron microscopy showed that Giardia attached to the apical microvillus membrane and basolateral membrane of rat enterocytes. Any location on th...

Inge, P. M.; Edson, C. M.; Farthing, M. J.

1988-01-01

37

Unusually Low Levels of Genetic Variation among Giardia lamblia Isolates? ‡  

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Giardia lamblia, an intestinal pathogen of mammals, including humans, is a significant cause of diarrheal disease around the world. Additionally, the parasite is found on a lineage which separated early from the main branch in eukaryotic evolution. The extent of genetic diversity among G. lamblia isolates is insufficiently understood, but this knowledge is a prerequisite to better understand the role of parasite variation in disease etiology and to examine the evolution of mechanisms of genet...

Teodorovic, Smilja; Braverman, John M.; Elmendorf, Heidi G.

2007-01-01

38

Description and characterization of a surface lectin from Giardia lamblia.  

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The mechanisms by which the human enteric pathogen Giardia lamblia colonizes the proximal small intestine are poorly understood. Although the parasite possesses an attachment organelle on its ventral surface, the "sucking" disk, we considered that like many bacteria and some protozoa, G. lamblia might also have a surface membrane-associated modality for adherence to its host. Using an erythrocyte mixed-agglutination model, we demonstrated a parasite surface lectin with specificities for D-glu...

Farthing, M. J.; Pereira, M. E.; Keusch, G. T.

1986-01-01

39

A lesson in survival, by Giardia lamblia.  

Science.gov (United States)

In the relationships between host and parasites, there is a cross-talk that involves diverse mechanisms developed by two different genetic systems during years of evolution. On the one hand, immunocompetent hosts have developed effective innate and acquired immune responses that are used to restrict or avoid parasitism. On the other hand, parasites evade the immune response, expressing different antigens on their surface or by using other specific mechanisms, such as nutrient depletion. In this review, we analyze the survival mechanisms used by the protozoan parasite Giardia lamblia during infection. In particular, we examine the multiple roles played by the enzyme arginine deiminase during colonization of the gut, also involving the parasite's mechanism of antigenic variation. Potential drug targets for the treatment of giardiasis are also discussed. PMID:20953552

Rópolo, Andrea S; Touz, Maria C

2010-01-01

40

Transient transfection and expression of firefly luciferase in Giardia lamblia.  

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We have developed a gene transfer system for the protozoan parasite Giardia lamblia. This organism is responsible for many cases of diarrhea worldwide and is considered to be one of the most primitive eukaryotes. Expression of a heterologous gene was detected in this parasite after electroporation with appropriate DNA constructs. We constructed a series of transfection plasmids using flanking sequences of the Giardia glutamate dehydrogenase (GDH) gene to drive expression of the firefly lucife...

Yee, J.; Nash, T. E.

1995-01-01

 
 
 
 
41

Giardia lamblia infections in B-cell-deficient transgenic mice.  

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In the present study, we infected B-cell (and antibody-)-deficient transgenic mice with the Giardia lamblia clone GS/M-83-H7. These animals were inhibited in intestinal anti-Giardia immunoglobulin A (IgA) production and could not resolve the parasite infection, and antigenic diversification within the respective parasite populations occurred in an unusually slow manner. These findings indicate an important immunological function of local IgA antibodies which promotes antigenic variation of th...

Stager, S.; Muller, N.

1997-01-01

42

Interleukin-6-Deficient Mice Are Highly Susceptible to Giardia lamblia Infection but Exhibit Normal Intestinal Immunoglobulin A Responses against the Parasite  

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In the present study, interleukin-6 (IL-6)-deficient mice were infected with Giardia lamblia clone GS/M-83-H7. Murine IL-6 deficiency did not affect the synthesis of parasite-specific intestinal immunoglobulin A. However, in contrast to wild-type mice, IL-6-deficient animals were not able to control the acute phase of parasite infection. Reverse transcription-PCR-based quantitation of cytokine mRNA levels in peripheral lymph node cells exhibited a short-term up-regulation of IL-4 expression i...

Bienz, Marianne; Dai, Wen Juan; Welle, Monika; Gottstein, Bruno; Mu?ller, Norbert

2003-01-01

43

Regulation of antigenic variation in Giardia lamblia.  

Science.gov (United States)

Antigenic variation, a clonal phenotypic variation developed by microorganisms, involves the permanent switching of homologous, antigenically different cell surface molecules. In pathogenic microorganisms, antigenic variation is often described as a mechanism to evade the host immune system and therefore is responsible for the generation of chronic and/or recurrent infections. However, antigenic variation has also been involved in expanding host diversity and differential courses of the diseases. The intestinal protozoan parasite Giardia lamblia undergoes antigenic variation through the continuous exchange of approximately 200 variant-specific surface proteins. Here we review the principal issues regarding the significance of antigenic variation during Giardia infections, the particular features of the variant-specific surface proteins, and the current knowledge on the mechanisms that regulate this process, as well as the relevance of disrupting antigenic variation as a novel approach to design effective antiparasitic vaccines. PMID:21740226

Prucca, César G; Rivero, Fernando D; Luján, Hugo D

2011-01-01

44

Guanine nucleotide-binding proteins in the intestinal parasite Giardia lamblia. Isolation of a gene encoding an approximately 20-kDa ADP-ribosylation factor.  

Science.gov (United States)

Giardia lamblia is a protozoan intestinal parasite that has characteristics of both eukaryotes and prokaryotes. To determine whether genes for guanine nucleotide-binding proteins are present in Giardia, genomic DNA and cDNA libraries were screened by polymerase chain reaction and by hybridization with mixed oligonucleotide probes complementary to sequences encoding conserved GTP-binding domains. A gene with a high degree of sequence identity with mammalian ADP-ribosylation factors (ARFs), believed to be important in vesicular transport, was identified. The Giardia ARF gene had a 573-base open reading frame encoding 191 amino acids which are 63-70% identical with known mammalian and yeast ARFs. Sequence conservation among ARFs was greatest in putative GTP-binding domains. A single ARF mRNA species of approximately 750 bases was found in two different Giardia isolates. Primer extension and RNA sequencing of the Giardia ARF transcript revealed a short (6-base) 5'-untranslated region similar in size to those found in other Giardia transcripts. Giardia extracts contained ARF activity, as shown by stimulation of cholera toxin-catalyzed ADP-ribosylation and a Giardia ARF expressed in Escherichia coli as a fusion protein likewise exhibited biochemical activity. Its presence in Giardia is consistent with the view that ARF emerged before the divergence of this protozoan from other eukaryotes (approximately 1.5 billion years ago), and that an ARF-like protein may have been the ancestor of several other classes of signal-transducing guanine nucleotide-binding proteins, including the alpha subunits of the heterotrimeric G proteins. PMID:1577802

Murtagh, J J; Mowatt, M R; Lee, C M; Lee, F J; Mishima, K; Nash, T E; Moss, J; Vaughan, M

1992-05-15

45

The abundance of sterile transcripts in Giardia lamblia  

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The protozoan parasite Giardia lamblia synthesizes a diverse and surprisingly abundant array of sterile transcripts unable to code for proteins. Random sampling of cDNAs from two evolutionarily divergent Giardia strains indicates that ?20% of cDNAs in the libraries represent polyadenylated sterile transcripts. RNase protection analysis and northern blot hybridization of three sterile transcript loci demonstrated that both the sterile transcript and a complementary mRNA were made in each cas...

Elmendorf, Heidi G.; Singer, Steven M.; Nash, Theodore E.

2001-01-01

46

Efficacies of Zinc-Finger-Active Drugs against Giardia lamblia  

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Twenty-nine of 34 (85%) Zn-finger-active compounds at 300 ?M or less inhibited the growth of Giardia lamblia. The most active compound, disulfiram (Antabuse), was cidal at 1.23 ± 0.32 ?M. In the adult mouse model, significant in vivo activity was demonstrated by increased cure rates and decreased parasite burdens.

Nash, Theodore; Rice, William G.

1998-01-01

47

Ingestion of Giardia lamblia trophozoites by human mononuclear phagocytes.  

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Mononuclear phagocytes may be important effector cells against Giardia lamblia. Human monocyte-derived macrophages were incubated with G. lamblia trophozoites in 13% heat-inactivated autologous serum. At a G. lamblia/macrophage ratio of 1:1, the number of trophozoites ingested per 100 macrophages ranged from 1 to 12 at 0.5 h and increased for all donors (n = 6) to 10 to 92 at 8 h. Ingestion was confirmed by electron microscopy. Increasing the parasite/phagocyte ratio to 5:1 increased the perc...

Hill, D. R.; Pearson, R. D.

1987-01-01

48

Electron microscopy of Giardia lamblia cysts.  

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The flagellated protozoan Giardia lamblia is a recognized public health problem. Intestinal infection can result in acute or chronic diarrhea with associated symptoms in humans. As part of a study to evaluate removal of G. lamblia cysts from drinking water by the processes of coagulation and dual-media filtration, we developed a methodology by using 5.0-microns-porosity membrane filters to evaluate the filtration efficiency. We found that recovery rates of G. lamblia cysts by membrane filtrat...

1980-01-01

49

The effect of hot water extract of Eucalyptus on Giardia lamblia parasite in vivo  

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Full Text Available The current study was conducted in the period from February 2012 till February 2013 to investigate the effect of Eucalyptus aqueous extract in G. lamblia in infected white mice Bulb/c. Flagyl was used in addition to the control solution (physiological solution as a control groups, the results of the study had been proved the effect of the extract by increasing the concentration without any side effect on the animals of the experiment and the results were as follows: The Eucalyptus extract 3000 mg/kg. is more efficient on G. lamblia compared with the Metronidazole and The 2000 mg/kg extract came next where it showed high treatment efficiency notably during the second day and finally the 1000 mg/kg extract came last which is the least effective during the 6th day compare with Flagyl, it was very effective during the fourth day. It was noticed, during a histological study of mice liver and small intestine tissues we notice hypoxia, necrosis, hypertrophy, and a congestion of blood vessels. There are significant differences for the Eucalyptus extract and Flagyl also with days treatment in compare with Flagyl.

Dr. Al - Quraishi Maher Ali

2013-08-01

50

Cytochrome b5 from Giardia lamblia.  

Science.gov (United States)

The protozoan intestinal parasite Giardia lamblia lacks mitochondria and the ability to make haem yet encodes several putative haem-binding proteins, including three of the cytochrome b(5) family. We cloned one of these (gCYTb5-I) and expressed it within Escherichia coli as a soluble holoprotein. UV-visible and resonance Raman spectra of gCYTb5-I resemble those of microsomal cytochrome b(5), and homology modelling supports a structure in which a pair of invariant histidine residues act as axial ligands to the haem iron. The reduction potential of gCYTb5-I is -165 mV vs. SHE and is relatively low compared to most values (-110 to +80 mV) for this class of protein. The amino- and carboxy-terminal sequences that flank the central haem-binding core of the Giardia cytochromes are highly charged and differ from those of other family members. A core gCYTb5-I variant lacking these flanking sequences was also able to bind haem. The presence of one actual and two probable functional cytochromes b(5) in Giardia is evidence of uncharacterized cytochrome-mediated metabolic processes within this medically important protist. PMID:23151674

Alam, Samiah; Yee, Janet; Couture, Manon; Takayama, Shin-ichi J; Tseng, Wan-Hsin; Mauk, A Grant; Rafferty, Steven

2012-12-01

51

Giardia lamblia: uptake of pyrimidine nucleosides.  

Science.gov (United States)

The aerotolerant, anaerobic parasite Giardia lamblia, which depends solely upon salvage pathways for its pyrimidine requirements, was found to transport uridine, cytidine, and thymidine by a carrier mediated mechanism. Support for this conclusion comes from the facts that uptake of radiolabeled uridine, cytidine, and thymidine exhibited saturation kinetics, and uptake of these same radiolabeled nucleosides was inhibited by unlabeled homologs, certain pyrimidine analogs, iodoacetate, and N-ethylmaleimide. Uridine and cytidine (perhaps uracil and cytosine also) are postulated to be transported at a common site which is distinct from the site for thymidine transport. Thymidine does appear to bind nonproductively to the uridine/cytidine transport site, but the reverse of this does not appear to occur. PMID:3569473

Jarroll, E L; Hammond, M M; Lindmark, D G

1987-04-01

52

Antigenic variation in Giardia lamblia and the host's immune response.  

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Giardia lamblia, a protozoan parasite of the small intestine of humans and other animals, undergoes surface antigenic variation. The antigens involved belong to a family of variant-specific surface proteins (VSPs), which are unique, cysteine-rich zinc finger proteins. The patterns of infection in humans and animals fail to show the expected cyclical waves of increasing and decreasing numbers of parasites expressing unique VSPs. Nevertheless, changes in VSP expression occur within the populati...

Nash, T. E.

1997-01-01

53

Putative SF2 helicases of the early-branching eukaryote Giardia lamblia are involved in antigenic variation and parasite differentiation into cysts  

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Full Text Available Abstract Background Regulation of surface antigenic variation in Giardia lamblia is controlled post-transcriptionally by an RNA-interference (RNAi pathway that includes a Dicer-like bidentate RNase III (gDicer. This enzyme, however, lacks the RNA helicase domain present in Dicer enzymes from higher eukaryotes. The participation of several RNA helicases in practically all organisms in which RNAi was studied suggests that RNA helicases are potentially involved in antigenic variation, as well as during Giardia differentiation into cysts. Results An extensive in silico analysis of the Giardia genome identified 32 putative Super Family 2 RNA helicases that contain almost all the conserved RNA helicase motifs. Phylogenetic studies and sequence analysis separated them into 22 DEAD-box, 6 DEAH-box and 4 Ski2p-box RNA helicases, some of which are homologs of well-characterized helicases from higher organisms. No Giardia putative helicase was found to have significant homology to the RNA helicase domain of Dicer enzymes. Additionally a series of up- and down-regulated putative RNA helicases were found during encystation and antigenic variation by qPCR experiments. Finally, we were able to recognize 14 additional putative helicases from three different families (RecQ family, Swi2/Snf2 and Rad3 family that could be considered DNA helicases. Conclusions This is the first comprehensive analysis of the Super Family 2 helicases from the human intestinal parasite G. lamblia. The relative and variable expression of particular RNA helicases during both antigenic variation and encystation agrees with the proposed participation of these enzymes during both adaptive processes. The putatives RNA and DNA helicases identified in this early-branching eukaryote provide initial information regarding the biological role of these enzymes in cell adaptation and differentiation.

Gargantini Pablo R

2012-11-01

54

Experimental infections of neonatal mice with cysts of Giardia lamblia clone GS/M-83-H7 are associated with an antigenic reset of the parasite.  

Science.gov (United States)

Transmission of the protozoan parasite Giardia lamblia from one to another host individuum occurs through peroral ingestion of cysts which, following excystation in the small intestine, release two trophozoites each. Many studies have focused on the major surface antigen, VSP (for variant surface protein), which is responsible for the antigenic variability of the parasite. By using trophozoites of G. lamblia clone GS/M-83-H7 (expressing VSP H7) and the neonatal mouse model for experimental infections, we quantitatively assessed the process of antigenic variation of the parasite on the transcriptional level. In the present study, variant-specific regions identified on different GS/M-83-H7 vsp sequences served as targets for quantitative reverse transcription-PCR to monitor alterations in vsp mRNA levels during infection. Respective results demonstrated that antigenic switching of both the duodenal trophozoite and the cecal cyst populations was associated with a massive reduction in vsp H7 mRNA levels but not with a simultaneous increase in transcripts of any of the subvariant vsp genes analyzed. Most importantly, we also explored giardial variant-type formation and vsp mRNA levels after infection of mice with cysts. This infection mode led to an antigenic reset of the parasite in that a VSP H7-negative inoculum "converted" into a population of intestinal trophozoites that essentially consisted of the original VSP H7 type. This antigenic reset appears to be associated with excystation rather than with a selective process which favors expansion of a residual population of VSP H7 types within the antigenically diversified cyst inoculum. Based on these findings, the VSP H7 type has to be regarded as a predominant variant of G. lamblia clone GS/M-83-H7 which (re-)emerges during early-stage infection and may contribute to an optimal establishment of the parasite within the intestine of the experimental murine host. PMID:15271938

von Allmen, N; Bienz, M; Hemphill, A; Müller, N

2004-08-01

55

Azasterols impair Giardia lamblia proliferation and induces encystation  

International Nuclear Information System (INIS)

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 IC50 values for 22,26-azasterol and 24(R,S),25-epiminolanosterol were 7 ?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 effective chemotherapeutic drugs against Giardia lamblia in vitro and may have another target in cells besides sterol biosynthesis

2007-11-16

56

Purine salvage networks in Giardia lamblia  

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Purine metabolism in Giardia lamblia was investigated by monitoring incorporation of radiolabeled precursors into purine nucleotides in the log-phase trophozoites cultivated in vitro in axenic media and incubated in buffered saline glucose. The lack of incorporation of formate, glycine, hypoxanthine, inosine, and xanthine into the nucleotide pool suggests the absence of de novo purine nucleotide synthesis and the inability to form IMP as the precursor of AMP and GMP in G. lamblia. Only adenin...

1983-01-01

57

Effect of Giardia lamblia Infection on the Cognitive Function of School children  

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Background: The association between helminthic parasitic infection and cognitive function has long been recognized, however there are few reports about Giardia lamblia infection. This paper describes a study about the effect of G. lamblia infection on the cognitive function. Methods: One hundred thirty two children infected with G. lamblia from Robat Karim south of western Tehran, Iran were compared with 150 children without any parasitic infection. These two groups were identical in socioeco...

Partovi, F.; Khalili, G.; Kariminia, A.; Mahmoudzadeh- Niknam, H.

2007-01-01

58

Giardia lamblia and other intestinal parasitic infections and their relationships with nutritional status in children in Brazilian Amazon Giardia lamblia e outros parasitas intestinais e sua relação com o status nutricional de crianças de uma área urbana na Amazônia Brasileira  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this survey was to assess the relationships between intestinal parasitism, nutritional status and hemoglobin level in children with Indian ascendancy living in an urban area in Brazilian Amazon. We carried out a cross-sectional survey obtaining anthropometric, parasitological and socioeconomic data, and hemoglobin measurements of children aged six to 84 months. Anthropometric data were expressed as z-scores for weight for age (WAZ, height for age (HAZ, weight for height (WHZ and mid upper circumference for age (MUACZ parameters. Parasitological examinations were performed through Ritchie (n = 307, Kato-Katz (n = 278, Baermann-Moraes (n = 238 and Safranin-methylene blue methods (n = 307. Hemoglobin measurements were obtained with a Hemocue® photometer (n = 282. Socioeconomic data were used in order to classify children in three family income strata (n = 242. Multiple linear regression analysis showed independent interactions between Giardia lamblia and WAZ (beta = -0.195, SE = 0.138, p = 0.003, WHZ (beta = -0.161, SE = 0.133, p = 0.018 and MUACZ (beta = -0.197, SE = 0.143, p = 0.011, controlling for age, sex, family income, Ascaris lumbricoides, and hookworm infection. Also, the multivariate model showed that the only variable associated with hemoglobin levels was age. Intestinal parasitism control should increase children's possibilities of full development in the studied area.O presente estudo objetivou avaliar a relação entre as parasitoses intestinais, o status nutricional e os níveis de hemoglobina em crianças vivendo em uma área urbana na Amazônia Brasileira. Foi realizado um estudo seccional, obtendo-se dados antropométricos, parasitológicos e socioeconômicos, além de dosagens de hemoglobina através do fotômetro Hemocue®, de crianças com idade entre seis e 84 meses. Os dados da antropometria foram expressos como escores de desvio-padrão (escores z para os parâmetros peso-idade (PI, altura-idade (AI, peso-altura (PA e perímetro braquial-idade (PBI. Os exames parasitológicos foram realizados através dos métodos de Ritchie (n = 307, Kato-Katz (n = 278, Baermann-Moraes (n = 238 e Safranina-Azul-de-Metileno (n = 307. A regressão linear múltipla demonstrou interações independentes entre Giardia lamblia e PI (beta = -0.195, p = 0.003, PA (beta = -0.161, p = 0.018 e PBI (beta = -0.197, p = 0.011, após controle para idade, sexo, renda familiar e infecções por Ascaris lumbricoides e ancilostomídeos. O modelo multivariado demonstrou ainda que a única variável associada aos níveis de hemoglobina foi a idade. O estudo concluiu que a giardíase está associada, nos sujeitos pesquisados, a menores médias para os parâmetros antropométricos estudados e que um controle efetivo das parasitoses intestinais poderia contribuir para o pleno desenvolvimento das crianças na área estudada.

Filipe Anibal Carvalho-Costa

2007-06-01

59

Giardia lamblia and other intestinal parasitic infections and their relationships with nutritional status in children in Brazilian Amazon / Giardia lamblia e outros parasitas intestinais e sua relação com o status nutricional de crianças de uma área urbana na Amazônia Brasileira  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O presente estudo objetivou avaliar a relação entre as parasitoses intestinais, o status nutricional e os níveis de hemoglobina em crianças vivendo em uma área urbana na Amazônia Brasileira. Foi realizado um estudo seccional, obtendo-se dados antropométricos, parasitológicos e socioeconômicos, além [...] de dosagens de hemoglobina através do fotômetro Hemocue®, de crianças com idade entre seis e 84 meses. Os dados da antropometria foram expressos como escores de desvio-padrão (escores z) para os parâmetros peso-idade (PI), altura-idade (AI), peso-altura (PA) e perímetro braquial-idade (PBI). Os exames parasitológicos foram realizados através dos métodos de Ritchie (n = 307), Kato-Katz (n = 278), Baermann-Moraes (n = 238) e Safranina-Azul-de-Metileno (n = 307). A regressão linear múltipla demonstrou interações independentes entre Giardia lamblia e PI (beta = -0.195, p = 0.003), PA (beta = -0.161, p = 0.018) e PBI (beta = -0.197, p = 0.011), após controle para idade, sexo, renda familiar e infecções por Ascaris lumbricoides e ancilostomídeos. O modelo multivariado demonstrou ainda que a única variável associada aos níveis de hemoglobina foi a idade. O estudo concluiu que a giardíase está associada, nos sujeitos pesquisados, a menores médias para os parâmetros antropométricos estudados e que um controle efetivo das parasitoses intestinais poderia contribuir para o pleno desenvolvimento das crianças na área estudada. Abstract in english The objective of this survey was to assess the relationships between intestinal parasitism, nutritional status and hemoglobin level in children with Indian ascendancy living in an urban area in Brazilian Amazon. We carried out a cross-sectional survey obtaining anthropometric, parasitological and so [...] cioeconomic data, and hemoglobin measurements of children aged six to 84 months. Anthropometric data were expressed as z-scores for weight for age (WAZ), height for age (HAZ), weight for height (WHZ) and mid upper circumference for age (MUACZ) parameters. Parasitological examinations were performed through Ritchie (n = 307), Kato-Katz (n = 278), Baermann-Moraes (n = 238) and Safranin-methylene blue methods (n = 307). Hemoglobin measurements were obtained with a Hemocue® photometer (n = 282). Socioeconomic data were used in order to classify children in three family income strata (n = 242). Multiple linear regression analysis showed independent interactions between Giardia lamblia and WAZ (beta = -0.195, SE = 0.138, p = 0.003), WHZ (beta = -0.161, SE = 0.133, p = 0.018) and MUACZ (beta = -0.197, SE = 0.143, p = 0.011), controlling for age, sex, family income, Ascaris lumbricoides, and hookworm infection. Also, the multivariate model showed that the only variable associated with hemoglobin levels was age. Intestinal parasitism control should increase children's possibilities of full development in the studied area.

Filipe Anibal, Carvalho-Costa; Alessandra Queiroga, Gonçalves; Sandra Laranjeira, Lassance; Luanda Macedo da, Silva Neto; Carla Alexandra Almeida, Salmazo; Marcio Neves, Bóia.

60

A Homogenous Luminescence Assay Reveals Novel Inhibitors for Giardia Lamblia Carbamate Kinase  

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The human pathogen Giardia lamblia is an anaerobic protozoan parasite that causes giardiasis, one of the most common diarrheal diseases worldwide. Although several drugs are available for the treatment of giardisis, resistance to these drugs has been reported and is likely to increase. The Giardia carbamate kinase (glCK) plays an essential role in Giardia metabolism and has no homologs in humans, making it an attractive candidate for anti-Giardia drug development. We have developed a luminesc...

Chen, Catherine Z.; Southall, Noel; Galkin, Andrey; Lim, Kap; Marugan, Juan J.; Kulakova, Liudmila; Shinn, Paul; Leer, Danielle; Zheng, Wei; Herzberg, Osnat

2012-01-01

 
 
 
 
61

PURE CULTURE METHOD: GIARDIA LAMBLIA FROM DIFFERENT STOOL SAMPLES  

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Full Text Available Introduction. Giardiasis is one of the health problems in the world including Iran. To determine the biochemical and biological problems and also identification of various strains, it is essential to obtain pure culture and then mass production of Giardia lamblia. The goal of this study was to isolate this protozoa purely.
Methods. Giardia lamblia cysts were isolated from 50 stool samples by use of floating of a four - layer of sucrose method. The cysts were transfered to an inducing solution. Subsequently, they were cultured in a modified culture medium (TYIS-33. Following excystation of trophozoite and its multiplication, the parasite was caltured and purified.
Findings. Excitation of trophozoite was observed in 40 samples (80 percent from which 22 samples (55 percent yielded pure culture. The doubling time was approximately 13hr and the peak of parasite was observed between third and fourth days.
Conclusion. The proliferation and growth rate of Giardia lamblia have enabled us to use this method widely. Cystein and ascorbic acid which are present in the induction solution, have a key role in excystation of trophozoite. Purification and passage of samples has facilitated the culture of this parasite in vitro. Therefore this method has yielded better results in comparison with other studies. This is probably due to a decrease in the amount of bovine bile or using different strains of Giardia lamblia in the present study.

H.A YOUSEFI

2000-03-01

62

Determining the molecular mechanism of inactivation by chemical modification of triosephosphate isomerase from the human parasite Giardia lamblia: a study for antiparasitic drug design.  

Science.gov (United States)

Giardiasis, the most prevalent intestinal parasitosis in humans, is caused by Giardia lamblia. Current drug therapies have adverse effects on the host, and resistant strains against these drugs have been reported, demonstrating an urgent need to design more specific antigiardiasic drugs. ATP production in G. lamblia depends mainly on glycolysis; therefore, all enzymes of this pathway have been proposed as potential drug targets. We previously demonstrated that the glycolytic enzyme triosephosphate isomerase from G. lamblia (GlTIM), could be completely inactivated by low micromolar concentrations of thiol-reactive compounds, whereas, in the same conditions, the activity of human TIM (HuTIM) was almost unaltered. We found that the chemical modification (derivatization) of at least one Cys, of the five Cys residues per monomer in GlTIM, causes this inactivation. In this study, structural and functional studies were performed to describe the molecular mechanism of GlTIM inactivation by thiol-reactive compounds. We found that the Cys222 derivatization is responsible for GlTIM inactivation; this information is relevant because HuTIM has a Cys residue in an equivalent position (Cys217). GlTIM inactivation is associated with a decrease in ligand affinity, which affects the entropic component of ligand binding. In summary, this work describes a mechanism of inactivation that has not been previously reported for TIMs from other parasites and furthermore, we show that the difference in reactivity between the Cys222 in GlTIM and the Cys217 in HuTIM, indicates that the surrounding environment of each Cys residue has unique structural differences that can be exploited to design specific antigiardiasic drugs. PMID:21786322

Enríquez-Flores, Sergio; Rodríguez-Romero, Adela; Hernández-Alcántara, Gloria; Oria-Hernández, Jesús; Gutiérrez-Castrellón, Pedro; Pérez-Hernández, Gerardo; de la Mora-de la Mora, Ignacio; Castillo-Villanueva, Adriana; García-Torres, Itzhel; Méndez, Sara T; Gómez-Manzo, Saúl; Torres-Arroyo, Angélica; López-Velázquez, Gabriel; Reyes-Vivas, Horacio

2011-09-01

63

Crystal Structures of Carbamate Kinase from Giardia lamblia Bound with Citric Acid and AMP-PNP  

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The parasite Giardia lamblia utilizes the L-arginine dihydrolase pathway to generate ATP from L-arginine. Carbamate kinase (CK) catalyzes the last step in this pathway, converting ADP and carbamoyl phosphate to ATP and ammonium carbamate. Because the L-arginine pathway is essential for G. lamblia survival and absent in high eukaryotes including humans, the enzyme is a potential target for drug development. We have determined two crystal structures of G. lamblia CK (glCK) with bound ligands. O...

Lim, Kap; Kulakova, Liudmila; Galkin, Andrey; Herzberg, Osnat

2013-01-01

64

Activity of the anthelmintic benzimidazoles against Giardia lamblia in vitro.  

Science.gov (United States)

In vitro growth of the protozoan parasite Giardia lamblia was highly sensitive to certain anthelmintic benzimidazoles. Albendazole and mebendazole were 30- to 50-fold more active than metronidazole and 4- to 40-fold more active than quinacrine. Thiabendazole, a noncarbamate benzimidazole, was less active. Since lack of intestinal absorption makes mebendazole an attractive new antigiardial agent, its in vitro activity was further characterized. At low concentrations (0.05 micrograms/ml) mebendazole had a static effect on G. lamblia growth; however, lethal activity was observed at a concentration fivefold lower (0.3 micrograms/ml) than necessary for the cidal agent metronidazole. Two observations are consistent with a microtubule target for mebendazole. First, attachment of cells to the culture tube, mediated by the ventral disk and flagella, was rapidly disrupted by mebendazole treatment. Second, the characteristic cell structure was grossly distorted by treatment. No mebendazole-resistant G. lamblia were detected in a population of 10(8) cells. PMID:2230276

Edlind, T D; Hang, T L; Chakraborty, P R

1990-12-01

65

Antigenic variation and the murine immune response to Giardia lamblia.  

Science.gov (United States)

The protozoan parasite Giardia lamblia is an important causative agent of acute or chronic diarrhoea in humans and various animals. During infection, the parasite survives the host's reactions by undergoing continuous antigenic variation of its major surface antigen, named VSP (variant surface protein). The VSPs form a unique family of cysteine-rich proteins that are extremely heterogeneous in size. The relevance of antigenic variation for the survival in the host has been most successfully studied by performing experimental infections in a combined mother/offspring mouse system and by using the G. lamblia clone GS/M-83-H7 (human isolate) as model parasite. In-vivo antigenic variation of G. lamblia clone GS/M-83-H7 is characterised by a diversification of the intestinal parasite population into a complex mixture of different variant antigen types. It could be shown that maternally transferred lactogenic anti-VSP IgA antibodies exhibit cytotoxic activity on the Giardia variant-specific trophozoites in suckling mice, and thus express a modulatory function on the proliferative parasite population characteristics. Complementarily, in-vitro as well as in-vivo experiments in adult animals indicated that non-immunological factors such as intestinal proteases may interfere into the process of antigen variation in that they favour proliferation of those variant antigen-type populations which resist the hostile physiological conditions within the intestine. These observations suggest that an interplay between immunological and physiological factors, rather than one of these two factor alone, modulates antigenic diversification of a G. lamblia population within an experimental murine host and thus influences the survival rate and strategy of the parasite. PMID:9925261

Müller, N; Gottstein, B

1998-12-01

66

Flagellar generated flow mediates attachment of Giardia Lamblia  

Science.gov (United States)

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.

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

2011-11-01

67

Adaptor Protein 2 Regulates Receptor-Mediated Endocytosis and Cyst Formation in Giardia lamblia  

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The parasite Giardia lamblia possesses peripheral vacuoles (PVs) that function as both endosomes and lysosomes and are implicated in the adaptation, differentiation, and survival of the parasite in different environments. The mechanisms by which Giardia traffics essential proteins to these organelles and regulates their secretion have important implications in the control of parasite dissemination. In this study, we describe the participation of the heterotetrameric clathrin-adaptor protein g...

Rivero, Maria R.; Vranych, Cecilia V.; Bisbal, Mariano; Maletto, Belkys A.; Ropolo, Andrea S.; Touz, Maria C.

2010-01-01

68

A Detailed, Hierarchical Study of Giardia lamblia's Ventral Disc Reveals Novel Microtubule-Associated Protein Complexes  

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Giardia lamblia is a flagellated, unicellular parasite of mammals infecting over one billion people worldwide. Giardia's two-stage life cycle includes a motile trophozoite stage that colonizes the host small intestine and an infectious cyst form that can persist in the environment. Similar to many eukaryotic cells, Giardia contains several complex microtubule arrays that are involved in motility, chromosome segregation, organelle transport, maintenance of cell shape and transformation between...

Schwartz, Cindi L.; Heumann, John M.; Dawson, Scott C.; Hoenger, Andreas

2012-01-01

69

Some hematimetric findings in human Giardia lambia infection Valores hematimétricos na infecção humana causada por Giardia lamblia  

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Up to now few reports about haematological alterations induced by Giardia lamblia infection have been described. Because there are questions on this matter still not answered, we carried out a study to evaluate some erythrometric and leucometric parameters in a sample that consisted of 55 patients exclusively infected with G. lamblia and of 55 sex and age matched parasite-free individuals. The haematological parameters evaluated were: mean corpuscular volume (MCV), hemoglobin concentration, a...

1996-01-01

70

Apo and calcium-bound crystal structures of cytoskeletal protein alpha-14 giardin (annexin E1) from the intestinal protozoan parasite Giardia lamblia.  

Science.gov (United States)

Alpha-14 giardin (annexin E1), a member of the alpha giardin family of annexins, has been shown to localize to the flagella of the intestinal protozoan parasite Giardia lamblia. Alpha giardins show a common ancestry with the annexins, a family of proteins most of which bind to phospholipids and cellular membranes in a Ca(2+)-dependent manner and are implicated in numerous membrane-related processes including cytoskeletal rearrangements and membrane organization. It has been proposed that alpha-14 giardin may play a significant role during the cytoskeletal rearrangement during differentiation of Giardia. To gain a better understanding of alpha-14 giardin's mode of action and its biological role, we have determined the three-dimensional structure of alpha-14 giardin and its phospholipid-binding properties. Here, we report the apo crystal structure of alpha-14 giardin determined in two different crystal forms as well as the Ca(2+)-bound crystal structure of alpha-14 giardin, refined to 1.9, 1.6 and 1.65 A, respectively. Although the overall fold of alpha-14 giardin is similar to that of alpha-11 giardin, multiwavelength anomalous dispersion phasing was required to solve the alpha-14 giardin structure, indicating significant structural differences between these two members of the alpha giardin family. Unlike most annexin structures, which typically possess N-terminal domains, alpha-14 giardin is composed of only a core domain, followed by a C-terminal extension that may serve as a ligand for binding to cytoskeletal protein partners in Giardia. In the Ca(2+)-bound structure we detected five bound calcium ions, one of which is a novel, highly coordinated calcium-binding site not previously observed in annexin structures. This novel high-affinity calcium-binding site is composed of seven protein donor groups, a feature rarely observed in crystal structures. In addition, phospholipid-binding assays suggest that alpha-14 giardin exhibits calcium-dependent binding to phospholipids that coordinate cytoskeletal disassembly/assembly during differentiation of the parasite. PMID:19046974

Pathuri, Puja; Nguyen, Emily Tam; Ozorowski, Gabriel; Svärd, Staffan G; Luecke, Hartmut

2009-01-30

71

Adherence of Giardia lamblia trophozoites to Int-407 human intestinal cells  

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Attachment of Giardia lamblia trophozoites to enterocytes is essential for colonization of the small intestine and is considered a prerequisite for parasite-induced enterocyte dysfunction and clinical disease. In this work, coincubation of Giardia with Int-407 cells, was used as an in vitro model to study the role of cytoskeleton and surface lectins involved in the attachment of the parasite. This interaction was also studied by scanning and transmission electron microscopy. Adherence was dep...

Sousa, M. Ce?u; Gonc?alves, C. A.; Bairos, V. A.; Poiares-da-silva, J.

2001-01-01

72

Opsonization in vitro of Giardia lamblia trophozoites.  

Science.gov (United States)

The ability of peritoneal rabbit macrophages from immunized and nonimmunized animals to phagocytose Giardia lamblia trophozoites in the presence of serum was studied and compared in an in vitro system. The rabbits which served as the source of immune serum and macrophages were injected repeatedly at multiple sites (intramuscularly, subcutaneously, and intradermally) with a mixture of G. lamblia trophozoites and Freund complete adjuvant. In the presence of normal rabbit serum, a low level of phagocytosis of Giardia trophozoites by normal and immune macrophages was observed. In the presence of hyperimmune rabbit serum, an increased phagocytic activity of both types of macrophages occurred. The opsonic activity was similar whether whole serum or purified immunoglobulin G was used and whether or not these were heat inactivated. G. lamblia trophozoites in suspension were shown to be agglutinated in the presence of hyperimmune serum. Tests employing serial dilutions of hyperimmune serum resulted in a parallel loss of opsonifying and agglutinating activities. It is suggested that opsonization in vivo may play a role in the ability of the host to limit infection by these organisms. Images

Radulescu, S; Meyer, E A

1981-01-01

73

Cholate-dependent killing of Giardia lamblia by human milk.  

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We showed previously that nonimmune human milk (NHM) kills Giardia lamblia trophozoites in vitro and presented evidence that killing requires the bile salt-stimulated lipase of milk. Since this enzyme is activated by bile salts, killing should be dependent on the presence of bile salts. We now show that killing by fresh NHM or NHM stored at -70 degrees C is totally dependent on sodium cholate (a bile salt). With less than 0.4 mM cholate, no parasites were killed, whereas with 1 mM cholate, gr...

1985-01-01

74

Tumor Necrosis Factor ? Contributes to Protection Against Giardia lamblia Infection in Mice  

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Giardia lamblia is a ubiquitous parasite that causes diarrhea. Effective control of Giardia infections in mice has been shown to involve IgA, T cells, mast cells, and IL-6. We now show that TNF? also plays an important role in the early control of giardiasis. Mice treated with neutralizing anti-TNF? antibodies or genetically deficient in TNF? were infected with the G. lamblia clone GS/(M)-H7. In both cases, mice lacking TNF? had much higher parasite numbers than controls during the first ...

Zhou, Ping; Li, Erqiu; Shea-donohue, Terez; Singer, Steven M.

2007-01-01

75

Giardia lamblia and Helicobater pylori Coinfection  

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"nBackground: Giardia lamblia and Helicobacter pylori are two flagellate microorganisms that grow in duodenum and stom­ach. The aim of this study was to evaluate the prevalence of them in patients with dyspepsia and other GI disorders. "nMethods: In this cross-sectional study, co-infection of above-mentioned agents was investigated in a group of 130 patients [me­dian age of 40 yr (range=11-79) including 76 males (58.8%)] with dyspepsia using three methods of duodenal aspirat...

Shafie, R.; MR Jahani; Rezaeian, M.; Amini, M.; Ar, Metvayi; Ebrahimi Daryani, N.; MR Keramati

2009-01-01

76

The abundance of sterile transcripts in Giardia lamblia.  

Science.gov (United States)

The protozoan parasite Giardia lamblia synthesizes a diverse and surprisingly abundant array of sterile transcripts unable to code for proteins. Random sampling of cDNAs from two evolutionarily divergent Giardia strains indicates that approximately 20% of cDNAs in the libraries represent polyadenylated sterile transcripts. RNase protection analysis and northern blot hybridization of three sterile transcript loci demonstrated that both the sterile transcript and a complementary mRNA were made in each case, further categorizing these sterile transcripts as antisense transcripts. Investigation of the genomic loci for these same three sterile antisense transcripts showed typical transcription units for the sense transcripts, but still failed to reveal a usable open reading frame for the sterile antisense transcripts. 5'-RACE mapped the transcription start site for one of the sterile antisense transcripts to an AT-rich region, as is typical for GIARDIA: It is unclear whether these sterile transcripts represent errors in transcription or whether they have regulatory functions within the cell, although preliminary investigations failed to reveal evidence for a role in developmental gene regulation. In either case, the presence of such a large pool of sterile antisense transcripts is dramatic evidence of the unusual molecular machinery of the early diverging protist G.lamblia. PMID:11713317

Elmendorf, H G; Singer, S M; Nash, T E

2001-11-15

77

Giardia lamblia and Helicobater pylori Coinfection  

Directory of Open Access Journals (Sweden)

Full Text Available "nBackground: Giardia lamblia and Helicobacter pylori are two flagellate microorganisms that grow in duodenum and stom­ach. The aim of this study was to evaluate the prevalence of them in patients with dyspepsia and other GI disorders. "nMethods: In this cross-sectional study, co-infection of above-mentioned agents was investigated in a group of 130 patients [me­dian age of 40 yr (range=11-79 including 76 males (58.8%] with dyspepsia using three methods of duodenal aspiration sam­ple, duodenal biopsy samples and evaluation of stool samples."nResults: : From 105 patients (59 males, 46 females, median age 40 years, range 11-79 entering this study from 3 hospitals, 4 patients (3.8% had G. lamblia and 61 patients (58% had H. pylori. All 4 patients infected by Giardia had also H. pylori infec­tion. Tenesmus (3 out of 4 patients was the most common symptom in patients with H. pylori infection (48 out of 61 pa­tients was reflux. Other symptoms in patients infected with both organisms (4 patients included diarrhea (2 cases, weight loss (2 cases, and loss of appetite (1 case but no report of vomiting."nConclusion: In patients co-infected with Giardia, H.pylori differentiation by physical examination is not possible. So in those patients with positive Rapid Urease Test (RUT, stool examination for Giardia detection is recommended. In addition, met­ronidazole (broad spectrum, anti-protozoal drug can be useful in H. pylori infection.

R Shafie

2009-03-01

78

Putative telomerase catalytic subunits from Giardia lamblia and Caenorhabditis elegans.  

Science.gov (United States)

Eukaryotic chromosomes end in short nucleotide repeats that are added by the enzyme telomerase. The catalytic subunit of telomerase has been shown to be most closely related in sequence to reverse transcriptases encoded by eukaryotic retrotransposable elements. This raises the question as to whether the telomerase subunit was present in the first eukaryotes or was derived during early eukaryote evolution from the replication machinery of a retrotransposable element. We present the sequence of a putative telomerase catalytic subunit from the diplomonad parasite, Giardia lamblia. The G. lamblia subunit appears to have most of the characteristics of other sequenced telomerases, except that it lacks the conserved telomerase-specific 'T' motif previously identified in other eukaryotic genes. Searching genomic databases with the G. lamblia sequence, we also identified a potential telomerase catalytic subunit from Caenorhabditis elegans. The C. elegans subunit is uncharacteristically short, and lacks several motifs found in all other telomerases. The identification of a G. lamblia telomerase similar to that of most other eukaryotes suggests that telomerase dates back to the earliest extant marker of eukaryotic evolution. The atypical C. elegans telomerase, on the other hand, raises intriguing biochemical questions concerning sub-domains of the telomerase catalytic subunit previously considered indispensable. The enzymatic machinery for telomere formation in C. elegans is likely to differ substantially from that of other eukaryotes. PMID:10876087

Malik, H S; Burke, W D; Eickbush, T H

2000-06-27

79

Kinetics of lymphocyte subpopulation in intestinal mucosa of protein deficient Giardia lamblia infected mice.  

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Kinetics of gut lymphocyte subpopulations were studied in normal and malnourished groups of mice infected with Giardia lamblia. The maximum parasite load was observed at second, third, and first week of postinfection in normal controls, moderate (8%) and severe (3%) protein deficient groups respectively. The number of G lamblia trophozoite in 3% protein deficient group was low compared with control groups. A significant increase in T cell population of intraepithelial lymphocytes and lamina p...

Upadhyay, P.; Ganguly, N. K.; Walia, B. N.; Mahajan, R. C.

1986-01-01

80

Effect of corticosteroid and irradiation on experimental Giardia lamblia infection in mice  

International Nuclear Information System (INIS)

Following infection with the parasite, Giardia lamblia, the faecal excretion rate of these cysts was studied in mice pre-treated with cortisone and/or whole body irradiation compared to controls. The cortisone/irradiation treatment increased the susceptibility to infection, as shown by the higher cyst excretion rate. Thus these treatments presumably depressed the cellular and humoral immunity normally present in G. lamblia infected mice. (UK)

1980-01-01

 
 
 
 
81

Molecular characterization of the cis-prenyltransferase of Giardia lamblia  

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Giardia lamblia, the protist that causes diarrhea, makes an Asn-linked-glycan (N-glycan) precursor that contains just two sugars (GlcNAc2) attached by a pyrophosphate linkage to a polyprenol lipid. Because the candidate cis-prenyltransferase of Giardia appears to be more similar to bacterial enzymes than to those of most eukaryotes and because Giardia is missing a candidate dolichol kinase (ortholog to Saccharomyces cerevisiae SEC59 gene product), we wondered how Giardia synthesizes dolichol ...

Grabin?ska, Kariona A.; Cui, Jike; Chatterjee, Aparajita; Guan, Ziqiang; Raetz, Christian R. H.; Robbins, Phillips W.; Samuelson, John

2010-01-01

82

High-Throughput Giardia lamblia Viability Assay Using Bioluminescent ATP Content Measurements?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The human pathogen Giardia lamblia is an anaerobic protozoan parasite that causes giardiasis, one of the most common diarrheal diseases worldwide. Although several drugs are available for the treatment of giardiasis, drug resistance has been reported and is likely to increase, and recurrent infections are common. The search for new drugs that can overcome the drug-resistant strains of Giardia is an unmet medical need. New drug screen methods can facilitate the drug discovery process and aid w...

Chen, Catherine Z.; Kulakova, Liudmila; Southall, Noel; Marugan, Juan J.; Galkin, Andrey; Austin, Christopher P.; Herzberg, Osnat; Zheng, Wei

2011-01-01

83

Amplification, expression, and packaging of a foreign gene by giardiavirus in Giardia lamblia.  

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Giardia lamblia is an intestinal protozoan parasite and one of the earliest eukaryotic divergents. The trophozoite multiplies via asexual binary fission and lacks all natural means of lateral gene transfer. A system is developed here for long-term expression of a foreign gene in this organism by exploiting recombinant virions derived from the giardiavirus (GLV), a double-stranded RNA virus that infects many Giardia isolates. An in vitro transcript of the cloned GLV cDNA, comprising the firefl...

Yu, D. C.; Wang, A. L.; Wang, C. C.

1996-01-01

84

A deeply divergent phosphoglucomutase (PGM) of Giardia lamblia has both PGM and phosphomannomutase activities  

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Giardia lamblia, which is an important parasitic cause of diarrhea, uses activated forms of glucose to make glycogen and activated forms of mannose to make glycophosphosphoinositol anchors. A necessary step for glucose activation is isomerization of glucose-6-phosphate to glucose-1-phosphate by a phosphoglucomutase (PGM). Similarly, a phosphomannomutase (PMM) converts mannose-6-phosphate to mannose-1-phosphate. While whole genome sequences of Giardia predict two PGM candidates, no PMM candida...

Mitra, Sanghamitra; Cui, Jike; Robbins, Phillips W.; Samuelson, John

2010-01-01

85

Effect of Giardia lamblia Infection on the Cognitive Function of School children  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The association between helminthic parasitic infection and cognitive function has long been recognized, however there are few reports about Giardia lamblia infection. This paper describes a study about the effect of G. lamblia infection on the cognitive function. Methods: One hundred thirty two children infected with G. lamblia from Robat Karim south of western Tehran, Iran were compared with 150 children without any parasitic infection. These two groups were identical in socioeconomic and nutritional status. Cognitive function was assessed using, three tests from Wechsler Intelligence Scale for children and one subset of the Clinical Evolution of Language Function. Results: Comparison of two groups revealed that uninfected children improved significantly more than children who had G. lamblia infection in the tests of Fluency (P< 0.02 and Digit-span Forwards/ Backwards (P< 0.004. Conclusion: Regular stool examination is suggested in areas with low hygienic conditions, since G. lamblia infection might be present without any clinical manifestation.

F Partovi

2007-05-01

86

Improved In Vitro Excystation Procedure for Giardia lamblia Cysts  

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Giardia lamblia cysts obtained from human symptomatic and asymptomatic donors were excysted in vitro. Excystation averaged 87% for cysts from symptomatic donors and 70% for cysts from asymptomatic donors.

Rice, Eugene W.; Schaefer, Frank W.

1981-01-01

87

Transient transfection and expression of firefly luciferase in Giardia lamblia.  

Science.gov (United States)

We have developed a gene transfer system for the protozoan parasite Giardia lamblia. This organism is responsible for many cases of diarrhea worldwide and is considered to be one of the most primitive eukaryotes. Expression of a heterologous gene was detected in this parasite after electroporation with appropriate DNA constructs. We constructed a series of transfection plasmids using flanking sequences of the Giardia glutamate dehydrogenase (GDH) gene to drive expression of the firefly luciferase reporter gene. The optimal construct consisted of a GDH/luciferase fusion gene in which the first 18 codons of the GDH gene immediately preceded the luciferase gene; this fusion gene was flanked by the upstream and downstream sequences of the GDH gene. Electroporation of this construct into Giardia yielded luciferase activity that was 3000- to 50,000-fold above background. Removal of either the 5' or 3' GDH flanking sequences from this construct resulted in significantly reduced luciferase activity, and removal of both flanking sequences reduced luciferase activity to background levels. Luciferase activity was proportional to the amount of DNA electroporated and was maximal at 6 hr after electroporation. PMID:7777558

Yee, J; Nash, T E

1995-06-01

88

PURE CULTURE METHOD: GIARDIA LAMBLIA FROM DIFFERENT STOOL SAMPLES  

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Introduction. Giardiasis is one of the health problems in the world including Iran. To determine the biochemical and biological problems and also identification of various strains, it is essential to obtain pure culture and then mass production of Giardia lamblia. The goal of this study was to isolate this protozoa purely.
Methods. Giardia lamblia cysts were isolated fro...

Yousefi, H. A.

2000-01-01

89

Isolation and identification of a Giardia lamblia-specific stool antigen (GSA 65) useful in coprodiagnosis of giardiasis.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A Giardia lamblia-specific antigen (GSA 65) was isolated from stools of G. lamblia-positive patients by crossed- and line-immunoelectrophoresis and counterimmunoelectrophoresis (CIE) in agarose by using rabbit antiserum prepared against G. lamblia cysts. CIE with rabbit anti-GSA 65 monospecific antiserum revealed that GSA 65 was present in aqueous stool eluates of giardiasis patients and in cysts and trophozoites of the parasite. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of im...

Rosoff, J. D.; Stibbs, H. H.

1986-01-01

90

The Cre/loxP system in Giardia lamblia: genetic manipulations in a binucleate tetraploid protozoan.  

Science.gov (United States)

The bacteriophage-derived Cre/loxP system is a valuable tool that has revolutionised genetic and cell biological research in many organisms. We implemented this system in the intestinal parasite Giardia lamblia, an evolutionarily diverged protozoan whose binucleate and tetraploid genome organisation severely limits the application of reverse genetic approaches. We show that Cre-recombinase is functionally expressed in G. lamblia and demonstrate "recycling" of selectable markers. Providing the means for more complex and versatile genetic modifications, this technique massively increases the scope of functional investigations in G. lamblia and other protozoa with similar limitations with respect to genetic manipulation. PMID:24747534

Wampfler, Petra B; Faso, Carmen; Hehl, Adrian B

2014-07-01

91

BILIARY LIPIDS SUPPORT SERUM-FREE GROWTH OF 'GIARDIA LAMBLIA'  

Science.gov (United States)

Giardia lamblia has only been grown in vitro in media containing serum or serum fractions. How this pathogen can grow in the human small intestinal lumen without serum is not known. The authors found that samples of human hepatic or gall bladder bile maintained G. lamblia surviva...

92

Chromosome sequence maps of the Giardia lamblia assemblage A isolate WB.  

Science.gov (United States)

Two genotypes, assemblages A and B, of the pathogenic gut protozoan parasite Giardia lamblia infect humans. Symptoms of infection range from asymptomatic to chronic diarrhea. Giardia chromosomes have long been characterized but not until the publication of the first Giardia genome sequence was chromosome mapping work, commenced nearly two decades ago, completed. Initial mapping studies identified and ordered Not I chromosome segments (summating to 1.8 Mb) of the estimated 2 Mb chromosome 3. The resulting map was confirmed with the release of the Giardia genome sequence and this revitalized mapping. The result is that 93% of the WB isolate genome sequence has now been assigned to one of five major chromosomes, and community access to these data has been made available through GiardiaDB, the database for Giardia genomes. PMID:20739222

Upcroft, Jacqui A; Krauer, Kenia G; Upcroft, Peter

2010-10-01

93

Glucosylceramide synthesis inhibition affects cell cycle progression, membrane trafficking, and stage differentiation in Giardia lamblia[S  

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Synthesis of glucosylceramide via glucosylceramide synthase (GCS) is a crucial event in higher eukaryotes, both for the production of complex glycosphingolipids and for regulating cellular levels of ceramide, a potent antiproliferative second messenger. In this study, we explored the dependence of the early branching eukaryote Giardia lamblia on GCS activity. Biochemical analyses revealed that the parasite has a GCS located in endoplasmic reticulum (ER) membranes that is active in proliferati...

S?tefanic?, Sas?a; Spycher, Cornelia; Morf, Laura; Fabria?s, Gemma; Casas, Josefina; Schraner, Elisabeth; Wild, Peter; Hehl, Adrian B.; Sonda, Sabrina

2010-01-01

94

Role of nitric oxide and superoxide in Giardia lamblia killing  

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Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhibited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) an...

Fernandes, P. D.; Assreuy, J.

1997-01-01

95

Tetracyclines as antiparasitic agents: lipophilic derivatives are highly active against Giardia lamblia in vitro.  

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Comparisons of the inhibitory activities of different tetracyclines have been reported for Plasmodium falciparum but no other parasites. The in vitro response of the intestinal parasite Giardia lamblia to six tetracyclines in current use was determined. In addition, the experimental drug thiacycline (EMD 33,330) was evaluated. Three groups were discerned, with representative 50 and 90% inhibitory concentrations of, respectively, 36 and 130 (tetracycline), 6.4 and 22 (doxycycline), and 1.8 and...

Edlind, T. D.

1989-01-01

96

snoRNAs in Giardia lamblia: a novel role in RNA silencing?  

Science.gov (United States)

In the expanding world of small regulatory RNAs, a recent paper by Saraiya and Wang has reported the identification in the protozoan parasite Giardia lamblia of a novel class of small RNAs, which are derived by Dicer processing of small nucleolar RNAs and have the potential to function as micro RNAs. Interestingly, these RNAs occur not only in this parasite but also in humans. PMID:19616476

Kolev, Nikolay G; Ullu, Elisabetta

2009-08-01

97

Detection and Genotyping of Entamoeba histolytica, Entamoeba dispar, Giardia lamblia, and Cryptosporidium parvum by Oligonucleotide Microarray  

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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...

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

2004-01-01

98

Neuronal Nitric Oxide Synthase is Necessary for Elimination of Giardia lamblia Infections in Mice1  

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Nitric oxide (NO) produced by inducible nitric oxide synthase (NOS2) is important for control of numerous infections. In vitro, NO inhibits replication and differentiation of the intestinal protozoan parasite Giardia lamblia. However, the role of NO against this parasite has not been tested in vivo. IL-6 deficient mice fail to control Giardia infections and these mice have reduced levels of NOS2 mRNA in the small intestine following infection compared to wild-type mice. However, NOS2 gene-tar...

Li, Erqiu; Zhou, Ping; Singer, Steven M.

2006-01-01

99

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

Science.gov (United States)

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...

100

Biliary lipids support serum-free growth of Giardia lamblia.  

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Giardia lamblia has been grown in vitro only in media containing serum or serum fractions. How this pathogen can grow in the human small intestinal lumen without serum is not known. We found that samples of human hepatic or gall bladder bile maintained G. lamblia survival for 24 to 48 h in medium without serum but did not support growth. By contrast, an artificial biliary lipid dispersion containing six bile salts, phosphatidylcholine (PC), and cholesterol, in the ratios characteristic of hum...

Gillin, F. D.; Gault, M. J.; Hofmann, A. F.; Gurantz, D.; Sauch, J. F.

1986-01-01

 
 
 
 
101

Comparison of Giardia lamblia and Giardia muris cyst inactivation by ozone.  

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Inactivation of Giardia lamblia and Giardia muris cysts was compared by using an ozone demand-free 0.05 M phosphate buffer in bench-scale batch reactors at 22 degrees C. Ozone was added to each trial from a concentrated stock solution for contact times of 2 and 5 min. The viability of the control and treated cysts was evaluated by using the C3H/HeN mouse and Mongolian gerbil models for G. muris and G. lamblia, respectively. The resistance of G. lamblia to ozone was not significantly different...

Finch, G. R.; Black, E. K.; Labatiuk, C. W.; Gyu?re?k, L.; Belosevic, M.

1993-01-01

102

Immunofluorescence and morphology of Giardia lamblia cysts exposed to chlorine.  

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Giardia cyst-like objects detected by immunofluorescence in chlorinated water samples often cannot be positively identified by their morphological appearance. To determine the effect of chlorine on cyst immunofluorescence and morphology, Giardia lamblia cysts were exposed to chlorine for 48 h. The majority of cysts exposed to chlorine concentrations of 1 to 11 mg/liter at 5 and 15 degrees C lost their internal morphological characteristics necessary for identification, but most of them were s...

Sauch, J. F.; Berman, D.

1991-01-01

103

Chitin synthetase in encysting Giardia lamblia and Entamoeba invadens  

International Nuclear Information System (INIS)

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 3H GlcNAc from UDP-GlcNAc 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

1987-05-01

104

Chitin synthetase in encysting Giardia lamblia and Entamoeba invadens  

Energy Technology Data Exchange (ETDEWEB)

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-GlcNAc 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.

Das, S.; Gillin, F.D.

1987-05-01

105

Isolate and epitope variability in susceptibility of Giardia lamblia to intestinal proteases.  

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The surface antigens of Giardia lamblia differ. To determine whether the unique surface antigens found in variants and isolates could differentially protect the parasite from digestion by intestinal protease, G. lamblia clones WB-2X (WB), GS/M-H7 (GS/M), and B6, each of which expresses a unique surface variant antigen, were exposed to alpha-chymotrypsin and trypsin at concentrations up to 20 mg/ml in culture medium. The number of surviving trophozoites and morphologic changes were assessed ov...

Nash, T. E.; Merritt, J. W.; Conrad, J. T.

1991-01-01

106

ARGININE DEIMINASE PLAYS MULTIPLE REGULATORY ROLES IN THE BIOLOGY OF GIARDIA LAMBLIA  

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The protozoan parasite Giardia lamblia utilizes arginine deiminase (gADI) to produce energy from free L-arginine under anaerobic conditions. In this work, we demonstrate that in addition to its known role as a metabolic enzyme, it also functions as a pepidtyl-arginine deiminase converting protein-bound arginine into citrulline. gADI specifically binds to and citrullinates the arginine in the conserved CRGKA tail of variant-specific surface proteins (VSPs) affecting both antigenic switching an...

Touz, Maria Carolina; Ropolo, Andrea Silvana; Rivero, Maria Romina; Vranych, Cecilia Veronica; Conrad, John Thomas; Svard, Staffan Gunnar; Nash, Theodore Elliot

2008-01-01

107

Bax Function in the Absence of Mitochondria in the Primitive Protozoan Giardia lamblia  

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Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant or...

Hehl, Adrian B.; Regos, Attila; Schraner, Elisabeth; Schneider, Andre?

2007-01-01

108

A Novel Family of Cyst Proteins with Epidermal Growth Factor Repeats in Giardia lamblia  

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The biological goal of Giardia lamblia life cycle is differentiation into a cyst form (encystation) that can survive in the environment and infect a new host. Since cystic stages are key to transmission of parasites, this differentiation may be a target for interruption of the life cycle. Synthesis and assembly of the extracellular cyst wall are the major hallmarks of this important differentiation. During encystation, cyst wall structural proteins are coordinately synthesized and are mainly ...

Chiu, Pei-wei; Huang, Yu-chang; Pan, Yu-jiao; Wang, Chih-hung; Sun, Chin-hung

2010-01-01

109

Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia  

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Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant or...

Hehl, Adrian B.; Regos, Attila; Schraner, Elisabeth; Schneider, Andre?

2008-01-01

110

Rapid Reinfection by Giardia Lamblia After Treatment in a Hyperendemic Community, During One Year Follow up  

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Background: Giardia lamblia is the most common intestinal parasite in the most parts of Iran, including Hamadan. Treatment of healthy cyst pass...

Fallah, M.

2011-01-01

111

Proteomic analysis of the ventral disc of Giardia lamblia  

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Abstract Background Giardia lamblia is a multiflagellated protozoan that inhabits the small intestine of vertebrates, causing giardiasis. To colonize the small intestine, the trophozoites form of the parasite remains attached to intestinal epithelial cells by means of cytoskeletal elements that form a structure known as the ventral disc. Previous studies have shown that the ventral disc is made of tubulin and giardins. Results To obtain further informat...

Lourenço Daniela; Andrade Iamara; Terra Letícia; Guimarães Patricia; Zingali Russolina; de Souza Wanderley

2012-01-01

112

Susceptibility of Giardia lamblia to aminoglycoside protein synthesis inhibitors: correlation with rRNA structure.  

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The very limited development of antiparasitic agents targeting protein synthesis stems in part from the belief that parasite and host ribosomes are sufficiently similar to preclude selective toxicity. However, recent studies have revealed that Giardia lamblia rRNA has an unusual size and sequence; consequently, this organism and its homogeneous rRNA provide a useful model for the development of protein synthesis inhibitors with antiparasitic activity. In this study, I determined the sequence ...

Edlind, T. D.

1989-01-01

113

Simultaneous Detection of Entamoeba histolytica, Giardia lamblia, and Cryptosporidium parvum in Fecal Samples by Using Multiplex Real-Time PCR  

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Entamoeba histolytica, Giardia lamblia, and Cryptosporidium are three of the most important diarrhea-causing parasitic protozoa. For many years, microscopic examination of stool samples has been considered to be the “gold standard” for diagnosis of E. histolytica, G. lamblia, and C. parvum infections. Recently, more specific and sensitive alternative methods (PCR, enzyme-linked immunosorbent assay, and direct fluorescent-antibody assay) have been introduced for all three of these parasiti...

Verweij, Jaco J.; Blange?, Roy A.; Templeton, Kate; Schinkel, Janke; Brienen, Eric A. T.; Rooyen, Marianne A. A.; Lieshout, Lisette; Polderman, Anton M.

2004-01-01

114

A sphingolipid inhibitor induces a cytokinesis arrest and blocks stage differentiation in Giardia lamblia.  

Science.gov (United States)

Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 muM. The inhibition of parasite replication was irreversible at 10 muM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents. PMID:18086854

Sonda, Sabrina; Stefanic, Sasa; Hehl, Adrian B

2008-02-01

115

Dual acylation accounts for the localization of {alpha}19-giardin in the ventral flagellum pair of Giardia lamblia  

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A Giardia-specific protein family denominated as alpha-giardins, represents the major protein component, besides tubulin, of the cytoskeleton of the human pathogenic parasite Giardia lamblia. One of its members, alpha19-giardin, carries an N-terminal sequence extension of MGCXXS, which in many proteins serves as a target for dual lipid conjugation: myristoylation at the glycine residue after removal of the methionine and palmitoylation at the cysteine residue. As the first experimental eviden...

Saric, M.; Vahrmann, A.; Niebur, D.; Kluempers, V.; Hehl, A. B.; Scholze, H.

2009-01-01

116

Dual Acylation Accounts for the Localization of ?19-Giardin in the Ventral Flagellum Pair of Giardia lamblia? †  

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A Giardia-specific protein family denominated as ?-giardins, represents the major protein component, besides tubulin, of the cytoskeleton of the human pathogenic parasite Giardia lamblia. One of its members, ?19-giardin, carries an N-terminal sequence extension of MGCXXS, which in many proteins serves as a target for dual lipid conjugation: myristoylation at the glycine residue after removal of the methionine and palmitoylation at the cysteine residue. As the first experimental evidence of ...

S?aric?, Mirela; Vahrmann, Anke; Niebur, Daniela; Kluempers, Verena; Hehl, Adrian B.; Scholze, Henning

2009-01-01

117

Use of an Enzyme Immunoassay Does Not Eliminate the Need To Analyze Multiple Stool Specimens for Sensitive Detection of Giardia lamblia  

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The relative sensitivities of a commercially available enzyme immunoassay (EIA) (ProSpecT Giardia; Alexon-Trend Inc., Ramsey, Minn.) and conventional ovum-and-parasite (O&P) examination for the detection of Giardia lamblia in preserved stool specimens were determined. Paired stool samples collected independently within a 7-day period from 103 patients were analyzed by both methods. A total of 54 specimens from 30 patients (18 asymptomatically infected with G. lamblia and 12 with symptoms cons...

Hanson, Kevan L.; Cartwright, Charles P.

2001-01-01

118

Bidirectional transcription is an inherent feature of Giardia lamblia promoters and contributes to an abundance of sterile antisense transcripts throughout the genome  

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A prominent feature of transcription in Giardia lamblia is the abundant production of sterile antisense transcripts (Elmendorf et al. The abundance of sterile transcripts in Giardia lamblia. Nucleic Acids., 29, 4674–4683). Here, we use a computational biology analysis of SAGE data to assess the abundance and distribution of sense and antisense messages in the parasite genome. Sterile antisense transcripts are produced at ?50% of loci with detectable transcription, yet their abundance at a...

Teodorovic, Smilja; Walls, Colleen D.; Elmendorf, Heidi G.

2007-01-01

119

Acute trichinellosis increases susceptibility to Giardia lamblia infection in the mouse model.  

Science.gov (United States)

The intestinal protozoan parasite Giardia lamblia causes diarrhoea in humans and animals. In the present study, we used the C57BL/6 inbred mouse model to assess the impact of a nematode (Trichinella spiralis) infection on the course of a G. lamblia (clone GS/M-83-H7) infection. Acute trichinellosis coincided with transient intestinal inflammation and generated an intestinal environment that strongly promoted growth of G. lamblia trophozoites although the local anti-Giardia immunoglobulin (Ig) A production was not affected. This increased G. lamblia infection intensity correlated with intestinal mast cell infiltration, mast cell degranulation, and total IgE production. Furthermore, a G. lamblia single-infection investigated in parallel also resulted in intestinal mast cell accumulation but severe infiltration was triggered in the absence of IgE. Recently, intestinal mast cells emerging during a G. lamblia infection were reported to be involved in those immunological mechanisms that control intestinal proliferation of the parasite in mice. This anti-giardial activity was assumed to be related to the capacity of mast cells to produce IL-6. However, this previous assumption was questioned by our present immunohistological findings indicating that murine intestinal mast cells, activated during a G. lamblia infection were IL-6-negative. In the present co-infection experiments, mast cells induced during acute trichinellosis were not able to control a concurrent G. lamblia infection. This observation makes it feasible that the T. spiralis infection created an immunological and physiological environment that superimposed the anti-giardial effect of mast cells and thus favoured intestinal growth of G. lamblia trophozoites in double-infected mice. Furthermore, our findings raise the possibility that intestinal inflammation e.g. as a consequence of a 'pre-existing' nematode infection is a factor which contributes to increased susceptibility of a host to a G. lamblia infection. The phenomenon of a 'pre-existing' nematode infection prior to a G. lamblia infection is a frequent constellation in endemic areas of giardiasis and may therefore have a direct impact on the epidemiological situation of the disease. PMID:16677442

von Allmen, N; Christen, S; Forster, U; Gottstein, B; Welle, M; Müller, N

2006-08-01

120

Neuronal nitric oxide synthase is necessary for elimination of Giardia lamblia infections in mice.  

Science.gov (United States)

NO produced by inducible NO synthase (NOS2) is important for the control of numerous infections. In vitro, NO inhibits replication and differentiation of the intestinal protozoan parasite Giardia lamblia. However, the role of NO against this parasite has not been tested in vivo. IL-6-deficient mice fail to control Giardia infections, and these mice have reduced levels of NOS2 mRNA in the small intestine after infection compared with wild-type mice. However, NOS2 gene-targeted mice and wild-type mice treated with the NOS2 inhibitor N-iminoethyl-L-lysine eliminated parasites as well as control mice. In contrast, neuronal NOS (NOS1)-deficient mice and wild-type mice treated with the nonspecific NOS inhibitor NG-nitro-L-arginine methyl ester and the NOS1-specific inhibitor 7-nitroindazole all had delayed parasite clearance. Finally, Giardia infection increased gastrointestinal motility in wild-type mice, but not in SCID mice. Furthermore, treatment of wild-type mice with NG-nitro-L-arginine methyl ester or loperamide prevented both the increased motility and the elimination of parasites. Together, these data show that NOS1, but not NOS2, is necessary for clearance of Giardia infection. They also suggest that increased gastrointestinal motility contributes to elimination of the parasite and may also contribute to parasite-induced diarrhea. Importantly, this is the first example of NOS1 being involved in the elimination of an infection. PMID:16365445

Li, Erqiu; Zhou, Ping; Singer, Steven M

2006-01-01

 
 
 
 
121

Arginine deiminase has multiple regulatory roles in the biology of Giardia lamblia.  

Science.gov (United States)

The protozoan parasite Giardia lamblia uses arginine deiminase (ADI) to produce energy from free L-arginine under anaerobic conditions. In this work, we demonstrate that, in addition to its known role as a metabolic enzyme, it also functions as a peptidylarginine deiminase, converting protein-bound arginine into citrulline. G. lamblia ADI specifically binds to and citrullinates the arginine in the conserved CRGKA tail of variant-specific surface proteins (VSPs), affecting both antigenic switching and antibody-mediated cell death. During encystation, ADI translocates from the cytoplasm to the nuclei and appears to play a regulatory role in the expression of encystation-specific genes. ADI is also sumoylated, which might modulate its activity. Our findings reveal a dual role played by ADI and define novel regulatory pathways used by Giardia for survival. PMID:18697833

Touz, Maria Carolina; Rópolo, Andrea Silvana; Rivero, Maria Romina; Vranych, Cecilia Veronica; Conrad, John Thomas; Svard, Staffan Gunnar; Nash, Theodore Elliott

2008-09-01

122

Treatment of Intestinal 'Entamoeba histolytica' and 'Giardia lamblia' with Metronidazole, Tinidazole and Ornidazole: A Comparative Study,  

Science.gov (United States)

Metronidazole, tinidazole and ornidazole were compared in patients treated for Entamoeba histolytica or Giardia lamblia intestinal infections. Only patients with three positive stool specimens for trophozoites and/or cysts of El histolytica or G. lamblia ...

S. Bassily Z. Farid N. A. El-Masry E. M. Mikhail

1987-01-01

123

Sensitive and Rapid Detection of Giardia lamblia Infection in Pet Dogs using Loop-Mediated Isothermal Amplification  

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Giardia lamblia is recognized as one of the most prevalent parasites in dogs. The present study aimed to establish a loop-mediated isothermal amplification (LAMP) assay for rapid and specific detection of G. lamblia from dogs. The fecal samples were collected and prepared for microscopic analysis, and then the genomic DNA was extracted directly from purified cysts. The concentration of DNA samples of G. lamblia were diluted by 10-fold serially ranging from 10-1 to 10-5 ng/µl for LAMP and PCR...

2013-01-01

124

Tetracyclines as antiparasitic agents: lipophilic derivatives are highly active against Giardia lamblia in vitro.  

Science.gov (United States)

Comparisons of the inhibitory activities of different tetracyclines have been reported for Plasmodium falciparum but no other parasites. The in vitro response of the intestinal parasite Giardia lamblia to six tetracyclines in current use was determined. In addition, the experimental drug thiacycline (EMD 33,330) was evaluated. Three groups were discerned, with representative 50 and 90% inhibitory concentrations of, respectively, 36 and 130 (tetracycline), 6.4 and 22 (doxycycline), and 1.8 and 3.4 (thiacycline) micrograms/ml. These dramatic differences in activity correlate with increased lipophilicity. PMID:2619281

Edlind, T D

1989-12-01

125

The cytotoxic effects of ciprofloxacin in Giardia lamblia trophozoites  

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The cytotoxicity of ciprofloxacin was investigated in culture of Giardia lamblia (ATCC 30957), used as an in vitro cellular model, on the basis of cell growth, morphology, viability, adherence and metabolic studies. The effects on cell membrane integrity were evaluated by permeability of the cells to trypan blue, and the morphological alterations were studied by optical and transmission electronic microscopy. The metabolic studies were performed by measured oxygen uptake with a Clark-type oxy...

Sousa, M. C.; Poiares-da-silva, J.

2001-01-01

126

Cytotoxicity Induced by Bismuth Subcitrate in Giardia lamblia Trophozoites  

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The cytotoxicity of colloidal bismuth subcitrate (CBS) was investigated in cultured Giardia lamblia trophozoites on the basis of cell attachment, morphology and viability studies. The effects on cell membrane integrity were evaluated by the permeability to trypan blue, and the morphological alterations were studied by phase-contrast microscopy and transmission electron microscopy. Our data show that although CBS induced loss of cellular viability (morphological and regrowth studies), the cell...

Sousa, M. C.; Poiares-da-silva, J.

1999-01-01

127

Nuclear inheritance and genetic exchange without meiosis in the binucleate parasite Giardia intestinalis  

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The protozoan parasite Giardia intestinalis (also known as Giardia lamblia) is a major waterborne pathogen. During its life cycle, Giardia alternates between the actively growing trophozoite, which has two diploid nuclei with low levels of allelic heterozygosity, and the infectious cyst, which has four nuclei and a tough outer wall. Although the formation of the cyst wall has been studied extensively, we still lack basic knowledge about many fundamental aspects of the cyst, including the sour...

Carpenter, Meredith L.; Assaf, Zoe June; Gourguechon, Ste?phane; Cande, W. Zacheus

2012-01-01

128

Oxidative stress-induced cell cycle blockage and a protease-independent programmed cell death in microaerophilic Giardia lamblia  

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Giardia lamblia is a microaerophilic human gastrointestinal parasite and considered as an early-diverged eukaryote. In vitro oxidative stress generation plays a significant role in cell cycle progression and cell death of this parasite. In the present study hydrogen peroxide, metronidazole, and a modified growth medium without cysteine and ascorbic acid have been chosen as oxidative stress-inducing agents. Cell cycle progression has been found to be regulated by different types of oxidative s...

Ghosh, Esha; Ghosh, Arjun; Ghosh, Amar Nath; Nozaki, Tomoyoshi; Ganguly, Sandipan

2009-01-01

129

Virtual Screening of Combinatorial Libraries across a Gene Family: in Search of Inhibitors of Giardia lamblia Guanine Phosphoribosyltransferase  

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Parasitic protozoa lack the ability to synthesize purine nucleotides de novo, relying instead on purine salvage enzymes for their survival. Guanine phosphoribosyltransferase (GPRT) from the protozoan parasite Giardia lamblia is a potential target for rational antiparasitic drug design, based on the experimental evidence, which indicates the lack of interconversion between adenine and guanine nucleotide pools. The present study is a continuation of our efforts to use three-dimensional structur...

Aronov, Alex M.; Munagala, Narsimha R.; Kuntz, Irwin D.; Wang, Ching C.

2001-01-01

130

Development of functional gastrointestinal disorders after Giardia lamblia infection  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Functional gastrointestinal disorders (FGID may occur following acute gastroenteritis. This long-term complication has previously not been described after infection with the non-invasive protozoan Giardia lamblia. This study aims to characterize persistent abdominal symptoms elicited by Giardia infection according to Rome II criteria and symptoms scores. Methods Structured interview and questionnaires 12–30 months after the onset of Giardia infection, and at least 6 months after Giardia eradication, among 82 patients with persisting abdominal symptoms elicited by the Giardia infection. All had been evaluated to exclude other causes. Results We found that 66 (80.5% of the 82 patients had symptoms consistent with irritable bowel syndrome (IBS and 17 (24.3% patients had functional dyspepsia (FD according to Rome II criteria. IBS was sub classified into D-IBS (47.0%, A-IBS (45.5% and C-IBS (7.6%. Bloating, diarrhoea and abdominal pain were reported to be most severe. Symptoms exacerbation related to specific foods were reported by 45 (57.7% patients and to physical or mental stress by 34 (44.7% patients. Conclusion In the presence of an IBS-subtype pattern consistent with post-infectious IBS (PI-IBS, and in the absence of any other plausible causes, we conclude that acute Giardia infection may elicit functional gastrointestinal diseases with food and stress related symptoms similar to FGID patients in general.

Hanevik Kurt

2009-04-01

131

Comparação de quatro métodos laboratoriais para diagnóstico da Giardia lamblia em fezes de crianças residentes em Belém, Pará / Evaluation of four techniques for diagnosis of Giardia lamblia in children's stool from Belém city, Para State, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Relatamos a comparação de quatro metodologias para o diagnóstico da Giardia lamblia em material fecal de crianças, Belém/PA. A Hematoxilina Férrica e o método direto apresentaram menor positividade, enquanto que o Método de Faust continua uma boa escolha para o diagnóstico e o Ensaio imunoenzimático [...] melhora a qualidade da detecção deste parasito. Abstract in english We report the evaluation of four techniques for Giardia lamblia diagnosis in children's stool. The Iron haematoxilin staining and direct examination with lugol showed lower positivity, while the method of Faust et al. Continues to be a good option for G. lamblia diagnosis and Immunoenzymatic assay i [...] ncreases the detection of this parasite.

Machado, Ricardo Luiz Dantas; Figueredo, Maria Cristina; Frade, Amanda Farage; Kudó, Mônica Eriko; Silva Filho, Manoel Gomes; Póvoa, Marinete Marins.

132

Comparison of microscopy, rapid immunoassay, and molecular techniques for the detection of Giardia lamblia and Cryptosporidium parvum.  

Science.gov (United States)

Giardia lamblia and Cryptosporidium parvum are recognized as the most common protozoan infections in Saudi Arabia. Microscopic examination of stool samples, either direct or concentrated, for the recovery of G. lamblia cysts and trophozoites and C. parvum oocysts is still the most commonly used for the diagnosis of both parasites. We compared the conventional parasitological techniques of iodine-stained wet mount for G. lamblia and Kinyoun's acid-fast for C. parvum against ImmunoCard STAT® Cryptosporidium/Giardia and real-time polymerase chain reaction (PCR) detecting the 18S rRNA gene of G. lamblia and conventional PCR detecting the same gene of C. parvum at a tertiary hospital in Dhahran, Saudi Arabia. Out of 148 stool samples, 19 and 12 true positives were identified for G. lamblia and C. parvum, respectively, using a composite reference standard. In this case, true positives and negatives were considered as those with at least two positive or negative results out of the three tests. Both ImmunoCard STAT! and PCR methods were more sensitive than the microscopic tests of a single stool specimen of 85.7% (CI=62.6-96.2%) and 85.7% (CI=56.2-97.5%) for G. lamblia and C. parvum, respectively. However, specificity of microscopic tests was higher than other techniques for both parasites. Although PCR seems to be most sensitive for both G. lamblia and C. parvum, its low specificity may render its superiority over other techniques. When a single stool sample is used for detection of G. lamblia and C. parvum, better results can be obtained when coupled with serological testing. Although PCR is the most sensitive method for the detection of both G. lamblia and C. parvum, its use requires attention in relation to the increased possible false positives. PMID:23411740

Elsafi, Salah H; Al-Maqati, Thekra N; Hussein, Mohi I; Adam, Ahmed A; Hassan, Mohamed M Abu; Al Zahrani, Eidan M

2013-04-01

133

Role of nitric oxide and superoxide in Giardia lamblia killing  

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Full Text Available Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine. Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites. This effect was inhibited (>90% by an NO synthase inhibitor (200 µM and unaffected by superoxide dismutase (SOD, 300 U/ml. Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP and sodium nitroprusside (SNP in a dose-dependent manner (LD50 300 and 50 µM, respectively. A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1, did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM. The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM. These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

Fernandes P.D.

1997-01-01

134

Role of nitric oxide and superoxide in Giardia lamblia killing  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhib [...] ited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 µM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM). The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM). These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

P.D., Fernandes; J., Assreuy.

135

An unusually compact ribosomal DNA repeat in the protozoan Giardia lamblia.  

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The ribosomal RNA (rRNA) genes of the protozoan parasite Giardia lamblia have been analyzed with respect to size, composition and copy number. They are found to be remarkable in several respects. First, the rRNAs themselves are the smallest yet reported for any eukaryotic organism. Second, the genes encoding them are found as an exceptionally small tandemly repeated unit of only 5.4 kilobase-pairs. Third, the genes are extraordinarily G:C rich, even in regions which are highly conserved betwe...

Boothroyd, J. C.; Wang, A.; Campbell, D. A.; Wang, C. C.

1987-01-01

136

[Research progress on the mechanisms of antigenic variation in Giardia lamblia].  

Science.gov (United States)

The intestinal protozoan parasite Giardia lamblia is one of the most common causes of diarrhoea and undergoes antigenic variation. In pathogenic microorganisms, antigenic variation is often described as a mechanism to evade the host immune system, resulting in chronic and/or recurrent infections. In the recent years, significant advances in the knowledge of the antigen switching process have been achieved. Here we review the principal knowledge on the mechanisms that regulate this process, including genomic organization, post-transcriptional gene silencing, expressional modifications, and processing and turnover of VSPs. PMID:23072166

Feng, Xian-Min; Wang, Yue-Hua; Ju, Xiao-Hong

2012-08-30

137

Isolation and expression of the gene for a major surface protein of Giardia lamblia.  

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To study the interactions between the parasitic protozoan Giardia lamblia and its environment, we have cloned the gene that encodes the two major surface-labeled trophozoite protein species. Sequence analysis of this gene reveals a single open reading frame specifying a hydrophilic, cysteine-rich (11.8%) protein of 72.5-kDa molecular mass with an amino-terminal signal peptide and a postulated hydrophobic membrane-spanning anchor region near the carboxyl terminus. Most of the cysteine residues...

Gillin, F. D.; Hagblom, P.; Harwood, J.; Aley, S. B.; Reiner, D. S.; Mccaffery, M.; So, M.; Guiney, D. G.

1990-01-01

138

Elevated levels of immunoglobulin A to Giardia lamblia during a waterborne outbreak of gastroenteritis.  

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During an outbreak of diarrheal illness among residents of a trailer park in rural Vermont, 37 (30%) of 122 residents met the case definition of outbreak-related giardiasis. Convalescent-phase sera from 24 residents and 20 nonresident control subjects were tested by enzyme-linked immunosorbent assay for immunoglobulin G (IgG), IgM, and IgA antibodies to Giardia lamblia. Residents showed higher levels of parasite-specific antibody than did nonresident controls for IgG and IgA but not IgM. Nine...

Birkhead, G.; Janoff, E. N.; Vogt, R. L.; Smith, P. D.

1989-01-01

139

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

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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 s...

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

140

Estudio de factores asociados con la reinfección por Giardia lamblia en niños de círculos infantiles  

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El protozoo Giardia lamblia, también conocido como Giardia duodenalis o Giardia intestinalis, es un parásito del intestino delgado que puede causar alta morbilidad tanto en países desarrollados como en los subdesarrollados. La infección por G. lamblia es más prevalente en niños de 1 a 5 años de edad, en especial aquellos que asisten a círculos infantiles. Teniendo en cuenta la alta frecuencia que puede alcanzar la infección por este protozoo en estas instituciones educacionales, y co...

Nu?n?ez Ferna?ndez, Fidel Angel

2005-01-01

 
 
 
 
141

Lysosomal protein trafficking in Giardia lamblia: common and distinct features  

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Giardia is a flagellated protozoan parasite that has to face different microenvironments during its life cycle in order to survive. All cells exchange materials with the extracellular medium through the reciprocal processes of endocytosis and secretion. Unlike more evolved cells, Giardia lacks a defined endosomal/lysosomal system, but instead possesses peripheral vacuoles that play roles in endocytosis, degradation, recycling, and secretion of proteins during growth and differentiation of the...

Touz, Maria C.; Rivero, Maria R.; Miras, Silvana L.; Bonifacino, Juan S.

2012-01-01

142

Mechanisms of Giardia lamblia differentiation into cysts.  

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Microbiologists have long been intrigued by the ability of parasitic organisms to adapt to changes in the environment. Since most parasites occupy several niches during their journey between vectors and hosts, they have developed adaptive responses which allow them to survive under adverse conditions. Therefore, the life cycles of protozoan and helminthic parasites are excellent models with which to study numerous mechanisms involved in cell differentiation, such as the regulation of gene exp...

Luja?n, H. D.; Mowatt, M. R.; Nash, T. E.

1997-01-01

143

Characterisation of alpha-1 giardin: an immunodominant Giardia lamblia annexin with glycosaminoglycan-binding activity.  

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Alpha-1 giardin is an immunodominant protein in the intestinal protozoan parasite Giardia lamblia. The Triage((R)) parasite panel, used to detect copro-antigens in stool from giardiasis patients, reacts with an epitope between amino acids 160 and 200 in alpha-1 giardin. This region of the protein is also highly immunogenic during human infections. Alpha-1 giardin is related to annexins and like many other annexins it was shown to be plasma membrane associated. Immunoelectron and immunofluorescence microscopy revealed that some alpha-1 giardin are displayed on the surface of recently excysted cells. Recombinant alpha-1 giardin displayed a Ca(2+)-dependent binding to glycosaminoglycans (GAGs), in particular heparan sulphate, a common GAG in the intestinal tract. Recombinant alpha-1 giardin bound to thin sections of human small intestine, a binding which could be inhibited by adding increasing concentrations of sulphated sugars. A surface associated trypsin activated Giardia lectin (taglin) has been suggested to be important for G. lamblia attachment. In this study we show that a monoclonal antibody that inhibits taglin recognises alpha-1 and alpha-2 giardin. Thus, alpha-1 giardin is a highly immunoreactive GAG-binding protein, which may play a key role in the parasite-host interaction. Our results further show a conserved function of annexins from lower to higher eukaryotes. PMID:14527517

Weiland, Malin E-L; Palm, J E Daniel; Griffiths, William J; McCaffery, J Michael; Svärd, Staffan G

2003-10-01

144

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

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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 resolution 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. PMID:22948920

Larson, Eric T; Kim, Jessica E; Napuli, Alberto J; Verlinde, Christophe L M J; Fan, Erkang; Zucker, Frank H; Van Voorhis, Wesley C; Buckner, Frederick S; Hol, Wim G J; Merritt, Ethan A

2012-09-01

145

Cryopreservation of Giardia lamblia with dimethyl sulfoxide using a Dewar flask.  

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This study examined the effect of varying freezing conditions on the human intestinal parasite Giardia lamblia (Portland-1 strain) using a constant vacuum in a Dewar flask and an ethanol bath to regulate the cooling rate. The cryopreservation of the trophozoite stage was investigated. Dimethyl sulfoxide (Me2SO), the cryoprotective agent of choice, was added directly to Giardia growth medium. Me2SO toxicity assays were conducted on those concentrations used in the freezing protocol. The results of this study indicated a 6.5% (v/v) Me2SO concentration yields a 90% survival based upon organism motility. A 30.9% cell viability was obtained by freezing in medium without a cryoprotective agent. Recommendations are offered concerning alternate viability criteria. PMID:6713946

Lyman, J R; Marchin, G L

1984-04-01

146

Oxidative stress-induced cell cycle blockage and a protease-independent programmed cell death in  microaerophilic Giardia lamblia  

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Esha Ghosh1, Arjun Ghosh1, Amar Nath Ghosh2, Tomoyoshi Nozaki3, Sandipan Ganguly11Division of Parasitology; 2Division of Electron Microscopy, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, West Bengal, India; 3Division of Parasitology, National Institute of Infectious Diseases, Tokyo, JapanAbstract: Giardia lamblia is a microaerophilic human gastrointestinal parasite and considered as an early-diverged eukaryote. In vitro oxidative stress generation plays a significa...

Esha Ghosh; Arjun Ghosh; Amar Nath Ghosh; Tomoyoshi Nozaki; Sandipan Ganguly

2009-01-01

147

vsp Gene Expression by Giardia lamblia Clone GS/M-83-H7 during Antigenic Variation In Vivo and In Vitro  

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Giardia lamblia infections are associated with antigenic variation of the parasite, which is generated by a continuous change of the variant-specific surface proteins (VSPs). Many investigations on the process of antigenic variation were based on the use of G. lamblia clone GS/M-83-H7, which expresses VSP H7 as its major surface antigen. In the present study, mice were infected with the aforementioned clonal line to investigate vsp gene expression during the complex process of antigenic varia...

Bienz, M.; Siles-lucas, M.; Wittwer, P.; Mu?ller, N.

2001-01-01

148

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

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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 exp...

Gemma Iñigo-Figueroa; Me?ndez-estrada, Rosa O.; Luis Quihui-Cota; Vela?squez-contreras, Carlos A.; Adriana Garibay-Escobar; Rafael Canett-Romero; Humberto Astiazarán-García

2013-01-01

149

Actividad lactásica en niños con enfermedad diarreica por Giardia lamblia  

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Full Text Available Se realizó un estudio prospectivo, de corte transversal y analítico, con el propósito de establecer posibles diferencias en el comportamiento de la actividad lactásica en niños menores de 2 años con enfermedad diarreica por Giardia lamblia tratados en el Servicio de Diarreas del Hospital Pediátrico Docente "Dr. Ángel A. Aballí", en el período de diciembre de 1994 a noviembre de 1995. Se determinaron los niveles de la actividad enzimática según diferentes categorías de variables de caracterización del niño y su enfermedad. Los resultados permitieron afirmar su reducción en estos niños, y que tal actividad tiene un comportamiento diferencial asociado con la edad, estado nutricional y grado de atrofia de la mucosa.A prospective analytical cross-sectional study was made with the objective of setting likely differences in Beta-galactosidase performance in under 2 years-old children admitted with diarrheal disease due to Giardia lamblia to «Ángel A. Aballí» Teaching Pediatric Hospital’s Diarrhea Service Unit from December 1994 to November 1995. Levels of the enzime activity were determined according to the several characterization variable categories of the child and his disease. The outcome showed the decline in diarrheal disease in thesechildren and the different performance patterns of this enzime depending on age, nutrition and mucosa atrophic level.

Arnaldo Izquierdo Estévez

1998-03-01

150

Adaptor protein 2 regulates receptor-mediated endocytosis and cyst formation in Giardia lamblia.  

Science.gov (United States)

The parasite Giardia lamblia possesses PVs (peripheral vacuoles) that function as both endosomes and lysosomes and are implicated in the adaptation, differentiation and survival of the parasite in different environments. The mechanisms by which Giardia traffics essential proteins to these organelles and regulates their secretion have important implications in the control of parasite dissemination. In the present study, we describe the participation of the heterotetrameric clathrin-adaptor protein gAP2 (Giardia adaptor protein 2) complex in lysosomal protein trafficking. A specific monoclonal antibody against the medium subunit (gmu2) of gAP2 showed localization of this complex to the PVs, cytoplasm and plasma membrane in the growing trophozoites. gAP2 also co-localized with clathrin in the PVs, suggesting its involvement in endocytosis. Uptake experiments using standard molecules for the study of endocytosis revealed that gAP2 specifically participated in the endocytosis of LDL (low-density lipoprotein). Targeted down-regulation of the gene encoding gmu2 in growing and encysting trophozoites resulted in a large decrease in the amount of cell growth and cyst wall formation, suggesting a distinct mechanism in which gAP2 is directly involved in both endocytosis and vesicular trafficking. PMID:20199400

Rivero, Maria R; Vranych, Cecilia V; Bisbal, Mariano; Maletto, Belkys A; Ropolo, Andrea S; Touz, Maria C

2010-05-15

151

Cryptosporidium Parvum y Giardia Lamblia en aguas crudas y tratadas del estado Bolívar, Venezuela / CRYPTOSPORIDIUM PARVUM AND GIARDIA LAMBLIA IN RAW AND TREATED WATERS OF THE BOLIVAR STATE  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Se identificó la presencia de Cryptosporidium parvum y Giardia lamblia en aguas de consumo humano antes y después del tratamiento físico-químico y en pozos profundos del estado Bolívar, utilizando el método de inmunofluorescencia con anticuerpos monoclonales (MeriFluor C/G® (Meridian Diagnostic, Inc [...] ) para Cryptosporidium parvum y Giardia y el método de tinción tricrómica para Microsporidium spp. Se demostró Cryptosporidium parvum (28,57%) y Giardia lamblia (23,81%) antes de tratamiento de las aguas y 14,2% de ambos protozoarios después del tratamiento. Ninguna muestra evidenció Microsporidium spp. Sólo uno de los pozos de agua presentó C. parvum (4,76%). Se concluye que Cryptosporidium parvum y Giardia lamblia son resistentes al tratamiento físico-químico de las aguas, lo cual constituye un riesgo para las personas que utilicen esas fuentes. Abstract in english The presence of Cryptosporidium Parvum and Giardia Lamblia was found in human drinking water before and after physical-chemical treatment in deep wells of the Bolívar State using the immunofluorescence method with monoclonal antibodies (MeriFluor C/G ® (Meridian Diagnostic, Inc) for Cryptosporidium [...] Parvum and Giardia, and the trichromic stain method for Microsporidium spp. The presence of Cryptosporidium Parvum (28.57%) and Giardia Lamblia (23.81%) was detected before the treatment of the water, and 14.2% of both protozoa after the treatment. No evidence of Microsporidium spp was found. Only one of the water wells revealed C. Parvum (4.76%). It is concluded that the Cryptosporidium Parvum and Giardia Lamblia are resistant to the physical-chemical treatment of the waters which constitutes a risk factor for the people using these sources.

Julman, Cermeño; Jewel, Arenas; Neyla, Yori; Isabel, Hernández.

152

Molecular characterisation of a predominant antigenic region of Giardia lamblia variant surface protein H7.  

Science.gov (United States)

During infection, the intestinal protozoan parasite Giardia lamblia undergoes continuous antigenic variation which is determined by diversification of the parasite's major surface antigen, named VSP (variant surface protein). One member from this protein family, VSP H7, is expressed by G. lamblia clone GS/M-83-H7. In the present study, we characterised a highly antigenic portion of VSP H7 which is positioned inside a 130 amino acid C-terminal region of the protein. This region overlaps with a cysteine-rich motif that is rather conserved within the VSP family. Detailed molecular dissection of the antigenic portion monitored a 12 amino acid peptidyl structure which constitutes a non-conformational epitope of VSP H7. In the murine host, this epitope is recognised relatively early (before day 10 p.i.) during infection and stimulates a strong intestinal immunoglobulin A response. At late infective stages (after day 10 p.i.) this immune reaction is progressively complemented by reactions against 'late' antigenic epitopes which are also located inside the 130 amino acid antigenic portion but in closer proximity to the C-terminal end of VSP H7 than the 12 amino acid epitope. Both the high antigenicity and the conserved character suggest that the 12 amino acid epitope is a key factor within the immunological interplay between G. lamblia and the experimental murine host. PMID:11403775

Bienz, M; Wittwer, P; Zimmermann, V; Müller, N

2001-06-01

153

Identification and characterization of gamma-giardin and the gamma-giardin gene from Giardia lamblia.  

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The giardins are abundant cytoskeletal proteins that range in size from 29-38 kDa and are specific to the ventral disk of the intestinal protozoan parasite Giardia lamblia. The 29-kDa (beta and beta-1; refs. 8-10) and the 33-kDa (alpha-1 and alpha-2; refs. 3 and 7) giardins have been characterized previously. In this paper we extend the analysis of the giardins to include the 38-kDa giardin, which we have named gamma-giardin. After purifying gamma-giardin by two-dimensional electrophoresis, we raised polyclonal antibodies to the protein and used them to demonstrate that gamma-giardin shares at least one epitope with 9 other giardin polypeptides and that it localizes to the ventral disk of the parasite. We also determined an internal peptide sequence of 12 amino acid residues and used this information to construct oligonucleotide probes for the gamma-giardin gene. After cloning the gene, we determined the nucleotide sequence of its 933-bp open reading frame and 866 bp of 5' and 3' flanking sequence. We found the downstream AGTPuAAPy motif typical of all G. lamblia genes sequenced to date, and determined that the single copy of the gamma-giardin gene localizes to the same chromosome or chromosomal cluster as the alpha-giardins. Finally, we demonstrated by primer extension analysis that gamma-giardin transcripts contain a short untranslated leader characteristic of G. lamblia messenger RNAs. PMID:1474999

Nohria, A; Alonso, R A; Peattie, D A

1992-11-01

154

Detection of Giardia lamblia Antigens in Human Fecal Specimens by a Solid-Phase Qualitative Immunochromatographic Assay?  

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The SIMPLE-READ Giardia rapid assay (Medical Chemical Corporation) is a solid-phase qualitative immunochromatographic assay that detects Giardia lamblia in aqueous extracts of human fecal specimens. Testing 106 Giardia-positive and 104 Giardia-negative stool specimens yielded a sensitivity of 97.2% and a specificity of 100% for the SIMPLE-READ Giardia rapid assay.

Garcia, Lynne S.; Garcia, John Paul

2006-01-01

155

Improved specificity for Giardia lamblia cyst quantification in wastewater by development of a real-time PCR method.  

Science.gov (United States)

The protozoan parasite Giardia lamblia is the most common cause of waterborne disease outbreaks associated with drinking water in the United States. The conventional method used for the enumeration of Giardia cysts in water is based on immunofluorescence with monoclonal antibodies. It is tedious and time-consuming and has the major drawback to be non-specific for the only species infecting humans, G. lamblia. We have developed a real-time polymerase chain reaction (PCR) method using fluorescent TaqMan technology, which improved the specificity of G. lamblia cyst quantification compared to the immunofluorescence assay (IFA). However, this PCR was not totally specific for G. lamblia species and amplified Giardia ardeae target as well. This method showed a sensitivity of 0.45 cysts per reaction and an efficiency of 95% in purified suspensions. We have then applied this quantification method to raw wastewater, a medium containing numerous debris, particles and PCR inhibitors. The adaptation to these environmental samples was realized by a screening of three cyst purification methods and six DNA extraction protocols. Real-time quantification was accomplished by the simultaneous amplification of unknown samples and a tenfold serial dilution of purified G. lamblia cysts. For all samples, the concentrations observed with TaqMan PCR method were compared to the IFA values. Giardia spp. cysts were detected in all non-spiked raw wastewater samples with IFA procedure and the concentrations of Giardia spp. cysts used for the comparison between the two methods ranged between 3.3x10(2)/l and 4.3x10(3)/l. The highest TaqMan PCR/IFA ratios were observed when Percoll/sucrose flotation was combined with DNA extraction protocol optimized for cyst wall lysis, impurities adsorption on a resin, and double step protein digestion and column purification. The concentrations observed with this TaqMan PCR method ranged from 2.5x10(2) to 2.4x10(3) G. lamblia cysts/l and only one sample resulted in a no amplification curve. Thus, we developed a TaqMan PCR method increasing the rapidity and specificity of G. lamblia cyst quantification. The combination of Percoll/sucrose flotation and DNA extraction optimized protocol before TaqMan assay has provided a good indication of the G. lamblia contamination level in raw sewage samples. PMID:15003687

Bertrand, Isabelle; Gantzer, Christophe; Chesnot, Thierry; Schwartzbrod, Janine

2004-04-01

156

Detection of a Giardia lamblia coproantigen by using a commercially available immunoenzymatic assay, in Belo Horizonte, Brazil  

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Full Text Available It is known that fecal examination to detect Giardia lamblia cysts or trophozoites produces a high percentage of false-negative results. A commercially available immunoenzymatic assay (ProSpecT Giardia Microplate Assay, Alexon, Inc., BIOBRÁS to detect G. lamblia specific coproantigen was evaluated for the first time in Brazil. A total of 90 specimens were tested. Each specimen was first tested as unpreserved stool, and then it was preserved in 10% Formalin to be tested 2 months later. The assay was able to identify all the 30 positive patients (sensitivity = 100.0% by visual or spectrophotometric examination in the unpreserved specimens and was negative in 57 of the 60 patients without G. lamblia (specificity = 95.0%. The assay identified 27 of the 30 positive patients (sensitivity = 90.0% and was negative in 59 of the 60 negatives (specificity = 98.3% in the preserved stools according to both readings. A marked difference was observed in the optical densities in both groups, preserved and unpreserved stools, when the G. lamblia-positive specimens were compared to the negative or positive for other intestinal parasites than G. lamblia. The assay seems a good alternative for giardiasis diagnosis, especially when the fecal examination was repeatedly negative and the patient presents giardiasislike symptoms.

ROCHA Míriam Oliveira e

1999-01-01

157

Aislamiento y axenización de Giardia lamblia en niños procedentes de círculos infantiles de Ciudad de La Habana  

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Full Text Available Se reporta el aislamiento de Giardia lamblia procedentes de niños de 3 círculos infantiles de Ciudad de La Habana. El 2,8 % de los aislamientos fue logrado utilizando la desenquistación in vitro, mientras que utilizando al gerbil como modelo animal para la desenquistación del parásito se logró el 97,2 %, lo que demostró la superioridad de este último método.It is reported the isolation of Giardia lamblia in children from three day care centers in Havana City. The 2,8 % of the isolations were obtained by using the disencystment in vitro, whereas using gerbil as an animal model for the parasite disencystment 97,2 % was attained. This result shows the superiority ot he latter.

Dinorah Torres

1996-12-01

158

Ozonoterapia en el síndrome de malabsorción intestinal secundario a parasitismo por Giardia lamblia: estudio preliminar  

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Full Text Available Se estudió el efecto de la ozonoterapia combinada (OLEOZON® oral y ozonoterapia rectal en el síndrome de malabsorción intestinal, secundario a parasitismo intestinal por Giardia lamblia. Se tomaron 186 pacientes y se formaron 3 grupos de 62 pacientes cada uno. El primer grupo se trató con metronidazol y vitaminoterapia, el segundo con OLEOZON® oral y vitaminoterapia y el tercero con ozonoterapia combinada y vitaminoterapia. Los pacientes fueron evaluados clínicamente por drenaje biliar y biopsia de yeyuno al inicio y final del tratamiento. Se alcanzó una mejoría importante en el tercer grupo (66,1 %, de los cuales, los diagnosticados tempranamente, 40,3 % obtuvo su curación. Se concluyó que la ozonoterapia combinada puede ser eficaz en esta patología.The effect of combined ozone therapy (oral OLEOZON® and rectal ozone therapy on the syndrome of intestinal malabsorption secondary to intestinal parasitism caused by Giardia lamblia was studied. 186 patients were selected and dividided into 3 groups of 62 patients each. The first group was treated with metronidazole and vitamin therapy, the second with oral OLEOZON® and vitamin therapy, and the third with combined ozone therapy and vitamin therapy. The patients were clinically evaluated by biliary drainage and jejunum biopsy at the beginning and at the end of the treatment. A significant improvement was observed in the third group (66.1 %. Of them, those that had been early diagnosed were cured (40.3 %. It was concluded that combined ozone therapy may be efficient in this pathology.

Nazarina Ivonne Méndez Pérez

2003-09-01

159

Prevalence and Spatial Distribution of Entamoeba histolytica/dispar and Giardia lamblia among Schoolchildren in Agboville Area (Côte d'Ivoire)  

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According to WHO, intestinal amoebiasis caused by Entamoeba histolytica is the third principal parasitic disease responsible for mortality in the world. This protozoal parasite infects approximately 180 million individuals throughout the world, among whom 40 to 110 thousand die from it each year. Giardiasis, caused by another protozoan parasite, Giardia lamblia, infects approximately 200 million individuals throughout the world, is a frequent cause of diarrhea in children, and can have negati...

Ouattara, Mamadou; N Gue?ssan, Nicaise A.; Yapi, Ahoua; N Goran, Elie?zer K.

2010-01-01

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ENCYSTATION AND EXPRESSION OF CYST ANTIGENS BY 'GIARDIA LAMBLIA' IN VITRO  

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The cyst form of Giardia lamblia is responsible for transmission of giardiasis, a major waterborne intestinal disease. These studies demonstrate for the first time expression of cyst antigens and encystation of G. lamblia in vitro by both morphologic and immunologic criteria. The...

 
 
 
 
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Routine in vitro cultivation of Giardia lamblia by using the string test.  

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In vitro axenic cultures of Giardia lamblia were successfully established in 14 successive subjects by a method employing the string test (Entero-Test) for obtaining samples of fluid from the proximal small intestine. This method is applicable to isolating G. lamblia from unselected subjects, including asymptomatic carriers, children, and individuals in diverse or remote geographic regions.

Korman, S. H.; Hais, E.; Spira, D. T.

1990-01-01

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Quantum Dots as a Novel Immunofluorescent Detection System for Cryptosporidium parvum and Giardia lamblia  

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Semiconductor quantum dot-conjugated antibodies were successfully developed to label Cryptosporidium parvum and Giardia lamblia. This novel fluorescence system exhibited superior photostability, gave 1.5- to 9-fold-higher signal-to-noise ratios than traditional organic dyes in detecting C. parvum, and allowed dual-color detection for C. parvum and G. lamblia.

Zhu, Liang; Ang, Simon; Liu, Wen-tso

2004-01-01

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Degradation of Giardia lamblia cysts in mixed human and swine wastes.  

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This study was conducted to determine the persistence of Giardia lamblia cysts in mixed septic tank effluent and swine manure slurry and to correlate fluorescein diacetate-propidium iodide staining of G. lamblia cysts with their morphology under low-voltage scanning electron microscopy. Under field conditions, G. lamblia cysts were degraded more rapidly in the mixed waste than in the control Dulbecco's phosphate-buffered saline (PBS). For total and viable cysts, the mixed waste had D values (...

Deng, M. Y.; Cliver, D. O.

1992-01-01

164

Serum antibodies to Giardia lamblia by age in populations in Colorado and Thailand.  

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We measured levels of antibodies to Giardia lamblia by age in serum specimens from persons in Denver, Colorado, and Soongnern, Thailand. Serum levels of immunoglobulin (Ig) G, IgM, and IgA G lamblia-specific antibodies measured by enzyme-linked immunosorbent assay increased substantially during childhood in both geographic areas, although children in Soongnern showed significantly higher mean levels of each antibody class (P less than .05). After adolescence, levels of G lamblia-specific IgM ...

Janoff, E. N.; Taylor, D. N.; Echeverria, P.; Glode, M. P.; Blaser, M. J.

1990-01-01

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Performance of Three Enzyme Immunoassays and Two Direct Fluorescence Assays for Detection of Giardia lamblia in Stool Specimens Preserved in ECOFIX  

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ECOFIX is a single-vial stool preservative that is both formalin- and mercury-free. We evaluated the abilities of three commercial Giardia lamblia-specific enzyme immunoassays (EIAs) (ProSpecT Giardia Microplate Assay [Alexon-Trend Inc.], Giardia Test [Techlab], and Premier Giardia lamblia [Meridian Diagnostics, Inc.]) and two commercial direct fluorescent-antibody (FA) assays for G. lamblia (Crypto/Giardia IF Test [Techlab] and Merifluor Cryptosporidium/Giardia [Meridian Diagnostics, Inc.]) ...

Fedorko, Daniel P.; Williams, Esther C.; Nelson, Nancy A.; Calhoun, Leslie B.; Yan, Sizhuang S.

2000-01-01

166

Genome ploidy in different stages of the Giardia lamblia life cycle.  

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The early diverging eukaryotic parasite Giardia lamblia is unusual in that it contains two apparently identical nuclei in the vegetative trophozoite stage. We have determined the nuclear and cellular genome ploidy of G. lamblia cells during all stages of the life cycle. During vegetative growth, the nuclei cycle between a diploid (2N) and tetraploid (4N) genome content and the cell, consequently, cycles between 4N and 8N. Stationary phase trophozoites arrest in the G2 phase with a ploidy of 8N (two nuclei, each with a 4N ploidy). On its way to cyst formation, a G1 trophozoite goes through two successive rounds of chromosome replication without an intervening cell division event. Fully differentiated cysts contain four nuclei, each with a ploidy of 4N, resulting in a cyst ploidy of 16N. The newly excysted cell, for which we suggest the term 'excyzoite', contains four nuclei (cellular ploidy 16N). In a reversal of the events occurring during encystation, the excyzoite divides twice to form four trophozoites containing two diploid nuclei each. The formation of multiple cells from a single cyst is likely to be one of the main reasons for the low infectious doses of G. lamblia. PMID:11207620

Bernander, R; Palm, J E; Svärd, S G

2001-01-01

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Crystal structures of carbamate kinase from Giardia lamblia bound with citric acid and AMP-PNP.  

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The parasite Giardia lamblia utilizes the L-arginine dihydrolase pathway to generate ATP from L-arginine. Carbamate kinase (CK) catalyzes the last step in this pathway, converting ADP and carbamoyl phosphate to ATP and ammonium carbamate. Because the L-arginine pathway is essential for G. lamblia survival and absent in high eukaryotes including humans, the enzyme is a potential target for drug development. We have determined two crystal structures of G. lamblia CK (glCK) with bound ligands. One structure, in complex with a nonhydrolyzable ATP analog, adenosine 5'-adenylyl-?,?-imidodiphosphate (AMP-PNP), was determined at 2.6 Å resolution. The second structure, in complex with citric acid bound in the postulated carbamoyl phosphate binding site, was determined in two slightly different states at 2.1 and 2.4 Å resolution. These structures reveal conformational flexibility of an auxiliary domain (amino acid residues 123-170), which exhibits open or closed conformations or structural disorder, depending on the bound ligand. The structures also reveal a smaller conformational change in a region associated the AMP-PNP adenine binding site. The protein residues involved in binding, together with a model of the transition state, suggest that catalysis follows an in-line, predominantly dissociative, phosphotransfer reaction mechanism, and that closure of the flexible auxiliary domain is required to protect the transition state from bulk solvent. PMID:23700444

Lim, Kap; Kulakova, Liudmila; Galkin, Andrey; Herzberg, Osnat

2013-01-01

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Sensitive and Rapid Detection of Giardia lamblia Infection in Pet Dogs using Loop-Mediated Isothermal Amplification  

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Giardia lamblia is recognized as one of the most prevalent parasites in dogs. The present study aimed to establish a loop-mediated isothermal amplification (LAMP) assay for rapid and specific detection of G. lamblia from dogs. The fecal samples were collected and prepared for microscopic analysis, and then the genomic DNA was extracted directly from purified cysts. The concentration of DNA samples of G. lamblia were diluted by 10-fold serially ranging from 10-1 to 10-5 ng/µl for LAMP and PCR assays. The LAMP assay allows the amplification to be finished within 60 min under isothermal conditions of 63? by employing 6 oligonucleotide primers designed based on G. lamblia elongation factor 1 alpha (EF1?) gene sequence. Our tests showed that the specific amplification products were obtained only with G. lamblia, while no amplification products were detected with DNA of other related protozoans. Sensitivity evaluation indicated that the LAMP assay was sensitive 10 times more than PCR. It is concluded that LAMP is a rapid, highly sensitive and specific DNA amplification technique for detection of G. lamblia, which has implications for effective control and prevention of giardiasis.

Li, Jie; Wang, Peiyuan; Zhang, Aiguo; Zhang, Ping; Alsarakibi, Muhamd

2013-01-01

169

Oxidative stress-induced cell cycle blockage and a protease-independent programmed cell death in  microaerophilic Giardia lamblia  

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Full Text Available Esha Ghosh1, Arjun Ghosh1, Amar Nath Ghosh2, Tomoyoshi Nozaki3, Sandipan Ganguly11Division of Parasitology; 2Division of Electron Microscopy, National Institute of Cholera and Enteric Diseases, Beliaghata, Kolkata, West Bengal, India; 3Division of Parasitology, National Institute of Infectious Diseases, Tokyo, JapanAbstract: Giardia lamblia is a microaerophilic human gastrointestinal parasite and considered as an early-diverged eukaryote. In vitro oxidative stress generation plays a significant role in cell cycle progression and cell death of this parasite. In the present study hydrogen peroxide, metronidazole, and a modified growth medium without cysteine and ascorbic acid have been chosen as oxidative stress-inducing agents. Cell cycle progression has been found to be regulated by different types of oxidative stresses. Apoptosis is not an established pathway in Giardia, which is devoid of ideal mitochondria, but in the present investigation, apoptosis-like programmed cell death has been found by the experiments like AnnexinV-FITC assay, DNA fragmentation pattern, etc. On the contrary, Caspase-9 assay, which confirms the caspase-mediated apoptotic pathway, has been found to be negative in all the stress conditions. Protease inhibitor assay confirmed that, even in absence of any proteases, programmed cell death does occur in this primitive eukaryote. All these results signify a novel pathway of programmed suicidal death in Giardia lamblia under oxidative stress. This is the first demonstration of protease-independent programmed cell death regulation in Giardia exclusive for its own specialties.Keywords: Giardia lamblia, oxidative stress, reactive oxygen species, programmed cell death, apoptosis, early branching eukaryotes

Esha Ghosh

2009-03-01

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GiardiaDB and TrichDB: integrated genomic resources for the eukaryotic protist pathogens Giardia lamblia and Trichomonas vaginalis  

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GiardiaDB (http://GiardiaDB.org) and TrichDB (http://TrichDB.org) house the genome databases for Giardia lamblia and Trichomonas vaginalis, respectively, and represent the latest additions to the EuPathDB (http://EuPathDB.org) family of functional genomic databases. GiardiaDB and TrichDB employ the same framework as other EuPathDB sites (CryptoDB, PlasmoDB and ToxoDB), supporting fully integrated and searchable databases. Genomic-scale data available via these resources may be queried based o...

Aurrecoechea, Cristina; Brestelli, John; Brunk, Brian P.; Carlton, Jane M.; Dommer, Jennifer; Fischer, Steve; Gajria, Bindu; Gao, Xin; Gingle, Alan; Grant, Greg; Harb, Omar S.; Heiges, Mark; Innamorato, Frank; Iodice, John; Kissinger, Jessica C.

2009-01-01

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Synchronisation of Giardia lamblia: identification of cell cycle stage-specific genes and a differentiation restriction point.  

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The intestinal parasite Giardia lamblia undergoes cell differentiations that entail entry into and departure from the replicative cell cycle. The pathophysiology of giardiasis depends directly upon the ability of the trophozoite form to replicate in the host upper small intestine. Thus, cell proliferation is tightly linked to disease. However, studies of cell cycle regulation in Giardia have been hampered by the inability to synchronise cultures. Here we report that Giardia isolates of the major human genotypes A and B can be synchronised using aphidicolin, a mycotoxin that reversibly inhibits replicative DNA polymerases in eukaryotic cells. Aphidicolin arrests Giardia trophozoites in the early DNA synthesis (S) phase of the cell cycle. We identified a set of cell cycle orthologues in the Giardia genome using bioinformatic analyses and showed that synchronised parasites express these genes in a cell cycle stage-specific manner. The synchronisation method also showed that during encystation, exit from the ordinary cell cycle occurs preferentially in G(2) and defines a restriction point for differentiation. Synchronisation opens up possibilities for further molecular and cell biological studies of chromosome replication, mitosis and segregation of the complex cytoskeleton in Giardia. PMID:18289546

Reiner, David S; Ankarklev, Johan; Troell, Karin; Palm, Daniel; Bernander, Rolf; Gillin, Frances D; Andersson, Jan O; Svärd, Staffan G

2008-07-01

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Development of functional gastrointestinal disorders after Giardia lamblia infection  

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Abstract Background Functional gastrointestinal disorders (FGID) may occur following acute gastroenteritis. This long-term complication has previously not been described after infection with the non-invasive protozoan Giardia lamblia. This study aims to characterize persistent abdominal symptoms elicited by Giardia infection according to Rome II criteria and symptoms scores. Methods Structured interview and questionnaires 12–30 months after t...

Hanevik Kurt; Dizdar Vernesa; Langeland Nina; Hausken Trygve

2009-01-01

173

Immuno-PCR for detection of Giardia lamblia cysts in water.  

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Giardia lamblia cysts at low concentrations were detected in water samples using a highly sensitive immunological-PCR (IPCR) method. Magnetic gold particles were precoated with monoclonal anti-Giardia antibodies, and Giardia lamblia cysts ranging from 1 to 100 cysts were diluted in 500 microL of water. A biotinylated detection antibody bound to the G. lamblia cysts was then linked by a streptavidin bridge to biotinylated Giardia-reporter DNA. After extensive washing, reporter DNA was released by denaturation, transferred to PCR tubes, amplified, electrophoresed, and visualized. An optimized immuno-PCR method detected as little as five G. lamblia cysts. To further evaluate the specificity and the clinical application of this IPCR assay for G. lamblia cysts, Entamoeba histolytica and Cryptosporidium parvum were also collected and detected by IPCR. The data demonstrated that this monoclonal antibody-based IPCR method is particularly useful for analysis of environmental water samples in which the densities of G. lamblia cysts is very low, and provides a platform capable of rapid screening of samples from drinking water, wells, rivers, lakes, and recreational swimming pools for trace levels of G. lamblia cysts. PMID:24830167

Deng, Ming Jun; Ji, Xin Cheng; Xiao, Xi Zhi; Sun, Tao; Wu, Zhen Xing; Zheng, Xiao Long; Wang, Qun; Zhu, Lai Hua

2014-01-01

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snoRNA, a Novel Precursor of microRNA in Giardia lamblia  

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An Argonaute homolog and a functional Dicer have been identified in the ancient eukaryote Giardia lamblia, which apparently lacks the ability to perform RNA interference (RNAi). The Giardia Argonaute plays an essential role in growth and is capable of binding specifically to the m7G-cap, suggesting a potential involvement in microRNA (miRNA)-mediated translational repression. To test such a possibility, small RNAs were isolated from Giardia trophozoites, cloned, and sequenced. A 26-nucleotide...

2008-01-01

175

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

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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.

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

2012-05-01

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Cloning of two putative Giardia lamblia glucosamine 6-phosphate isomerase genes only one of which is transcriptionally activated during encystment.  

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The biosynthesis of the carbohydrate component of the cyst wall of the protozoan parasite Giardia lamblia, a polymer of N-acetylgalactosamine (GalNac), is by a pathway that is initiated with the conversion of fructose 6-phosphate to glucosamine 6-phosphate by an aminating isomerase, glucose 6-phosphate isomerase. This enzyme appears only after Giardia trophozoites are induced to start the production of cyst wall components after bile is added. To investigate whether induction of glucosamine 6-phosphate isomerase is by protein modification or by transcription activation, its gene was cloned and sequenced. Two genes, gpi1 and gpi2, encoding putative glucosamine 6-phosphate isomerases were identified but one, gpi1 was expressed. The transcript for gpi1 appeared not earlier than 6 h after cells were induced with bile salts. These results show that the first enzyme in the pathway leading to GalNac synthesis in encysting Giardia cyst wall biosynthesis is under transcriptional control. PMID:9864853

Van Keulen, H; Steimle, P A; Bulik, D A; Borowiak, R K; Jarroll, E L

1998-01-01

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Detection of Giardia lamblia and Cryptosporidium parvum Antigens in Human Fecal Specimens Using the ColorPAC Combination Rapid Solid-Phase Qualitative Immunochromatographic Assay  

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The ColorPAC Giardia/Cryptosporidium (Becton Dickinson) is a solid-phase qualitative immunochromatographic assay that detects and distinguishes between Giardia lamblia and Cryptosporidium parvum in human stool. Agreement between the Alexon-Trend ProSpecT Giardia Rapid EIA and the ColorPAC assay was 166 of 172 (96.5%). Agreement between the Alexon-Trend ProSpecT Cryptosporidium Rapid EIA and the ColorPAC assay was 169 of 171 (98.8%). No cross-reactions were seen with other parasites or human c...

Garcia, Lynne S.; Shimizu, Robyn Y.

2000-01-01

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ELISA y técnica de sedimentación espontánea para el diagnóstico de infección por Giardia lamblia en muestras fecales de niños de Perú ELISA and spontaneous sedimentation technique for the diagnosis of Giardia lamblia infection in stool samples of Peruvian children  

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Full Text Available OBJETIVO: Comparar un kit ELISA comercial para coproantígenos y la técnica de sedimentación espontánea en tubo (TSET para el diagnóstico de Giardia lamblia en muestras fecales de niños de una zona endémica peruana. MATERIAL Y MÉTODOS: Fueron analizadas 174 muestras mediante la TSET y el kit Giardia 2nd Generation ELISA. RESULTADOS: Fueron positivas 51 muestras por ELISA y 49 por TSET. CONCLUSIONES: El ELISA resultó ser altamente sensible y específico, sencillo y rápido; sin embargo, la muy buena concordancia, alta precisión, bajo costo y capacidad para detectar otros enteroparásitos hace que la TSET sea recomendable para el diagnóstico en zonas endémicas del Perú.OBJETIVE: To compare a commercial coproantigen ELISA kit and the technique of spontaneous sedimentation in tube (TSET for the diagnosis of Giardia lamblia in fecal specimens from children in a Peruvian endemic area. MATERIAL AND METHODS: 174 fecal samples were analyzed by TSET and 2nd Generation Giardia ELISA kit. RESULTS: 51 samples were positive by ELISA and 49 by TSET. CONCLUSIONS: The ELISA was highly sensitive and specific, simple and fast. However, the very good agreement, high precision, low cost and ability to detect other intestinal parasites makes use of TSET recommended for laboratory diagnosis in endemic areas of Peru.

Claudia Rodríguez-Ulloa

2011-12-01

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An unusually compact ribosomal DNA repeat in the protozoan Giardia lamblia.  

Science.gov (United States)

The ribosomal RNA (rRNA) genes of the protozoan parasite Giardia lamblia have been analyzed with respect to size, composition and copy number. They are found to be remarkable in several respects. First, the rRNAs themselves are the smallest yet reported for any eukaryotic organism. Second, the genes encoding them are found as an exceptionally small tandemly repeated unit of only 5.4 kilobase-pairs. Third, the genes are extraordinarily G:C rich, even in regions which are highly conserved between all other eukaryotic rRNA genes. Finally, by analogy to other organisms, the 5.8S RNA appears to lack about 15 nucleotides from its 3'-end, a region previously thought to be essential for 5.8S RNA function. We also provide the first estimates of the genomic complexity and total G:C content of this important protozoan pathogen. PMID:3588284

Boothroyd, J C; Wang, A; Campbell, D A; Wang, C C

1987-05-26

180

In situ analyses reveal that the two nuclei of Giardia lamblia are equivalent.  

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The protozoan parasite Giardia lamblia has the unusual morphology of bearing two equal-sized nuclei. This organism probably represents the earliest diverging lineage of eukaryotes, suggesting that its biological tactics may be transitional. To begin to understand the role played by the two equal-sized nuclei in this organism, and perhaps the role this organism has played along the path to higher eukaryotes, we have analyzed the structure and function of these two nuclei. We show that the two nuclei are equivalent with respect to the amount of DNA harbored in each nucleus, the presence of ribosomal DNA sequences, and the transcriptional activity. We begin also to address the question of how these bilaterally symmetrical ancestors divide, by illustrating the mitotic plane of division. PMID:2384520

Kabnick, K S; Peattie, D A

1990-03-01

 
 
 
 
181

Giardia lamblia Transcriptome Analysis Using TSS-Seq and RNA-Seq  

Science.gov (United States)

Giardia lamblia is a protozoan parasite that is found worldwide and has both medical and veterinary importance. We applied the transcription start sequence (TSS-seq) and RNA sequence (RNA-seq) techniques to study the transcriptome of the assemblage A WB strain trophozoite. We identified 8000 transcription regions (TR) with significant transcription. Of these regions, 1881 TRs were more than 500 nucleotides upstream of an annotated ORF. Combining both techniques helped us to identify 24 ORFs that should be re-annotated and 60 new ORFs. From the 8000 TRs, we were able to identify an AT-rich consensus that includes the transcription initiation site. It is possible that transcription that was previously thought to be bidirectional is actually unidirectional.

Tolba, Mohammed E. M.; Kobayashi, Seiki; Imada, Mihoko; Suzuki, Yutaka; Sugano, Sumio

2013-01-01

182

Giardia lamblia e alergia respiratória: estudo em uma amostra de crianças de área urbana com frequência elevada da protozoose / Giardia lamblia and respiratory allergies: a study of children from an urban area with a high incidence of protozoan infections  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Uma elevada incidência de enteroparasitoses é encontrada em regiões urbanas do nordeste brasileiro. As infecções por Giardia lamblia têm sido relacionadas com aumento da prevalência de alergias cutâneas e gastrointestinais. Contudo, ainda existe pouca informação sobre a associação entre a [...] giardíase e doenças alérgicas das vias aéreas. Diante disso, o presente estudo se propôs a verificar a relação entre a infecção por G. lamblia em crianças de área urbana e reatividade alérgica respiratória. MÉTODOS: O estudo incluiu 110 pacientes, de ambos os sexos e idades, entre 5 e 15 anos. Os pacientes foram submetidos a questionários de avaliação dos sintomas clínicos, testes cutâneos de leitura imediata e exames coproparasitológicos e sorológicos. RESULTADOS: Foi verificada uma frequência elevada de crianças infectadas por G. lamblia (45%, 50/110). A infecção pelo protozoário não foi associada com maior risco de alergias respiratórias (p = 0,075), elevação de IgE total (p = 0,701), IgE específica (p = 0,250) ou teste cutâneo positivo para diferentes alérgenos ambientais (p = 0,239). CONCLUSÃO: O estudo demonstrou que a presença dos sintomas de asma, atopia cutânea e marcadores sorológicos não foram associados com a presença de infecção pela G. lamblia nessa amostra de crianças. Abstract in english OBJECTIVES: There is a high incidence of intestinal parasite infection in urban areas in the Northeast of Brazil. Giardia lamblia infections have been associated with increased prevalence of cutaneous allergies and gastrointestinal disorders. However, little is known about the relationship between g [...] iardiasis and allergic diseases of the airways. The present study aimed to investigate the possible association between respiratory allergic diseases and infections by G. lamblia in children from urban areas. METHODS: This study recruited 110 patients of both sexes aged 5-15 years. Patients were administered a questionnaire evaluating clinical symptoms and were given skin tests, parasite tests and serum tests. RESULTS: A high incidence of G. lamblia was observed (45%, 50/110). Infections by this protozoan were not associated with increased risk of respiratory allergy (p = 0.075), high total IgE levels (p = 0.701), positive specific IgE tests (p = 0.250), or positive skin tests for a range of environmental allergens (p = 0.239). CONCLUSION: This study demonstrated that symptoms of asthma, skin allergy and serum markers were not associated with G. lamblia infections in this sample of children from urban areas.

Valdênia M. O., Souza; Iana R. F., Sales; Décio M., Peixoto; Vláudia M. Assis, Costa; José A., Rizzo; Almerinda R., Silva; Roberta Faria, Camilo; Felipe Faria, Pierotti; Dirceu, Solé; Emanuel S. C., Sarinho.

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A novel ARID/Bright-like protein involved in transcriptional activation of cyst wall protein 1 gene in Giardia lamblia.  

Science.gov (United States)

The capability of protozoan parasite Giardia lamblia to encyst is critical for survival outside the host and its transmission. AT-rich interaction domain (ARID) or Bright homologs constitute a large family of transcription factors in higher eukaryotes that regulate cell proliferation, development, and differentiation. We asked whether Giardia has ARID-like genes and whether they influence gene expression during Giardia encystation. Blast searches of the Giardia genome data base identified two genes with putative ARID/Bright domains (gARID1 and 2). Epitope-tagged gARID1 was found to localize to nuclei. Recombinant gARID1 specifically bound to the encystation-induced cyst wall protein (cwp) gene promoters. Mutation analysis revealed that AT-rich initiators were required for binding of gARID1 to the cwp promoters. gARID1 contains several key residues for DNA binding, and its binding sequences are similar to those of the known ARID family proteins. The gARID1 binding sequences were positive cis-acting elements of the cwp1 promoter during both vegetative growth and encystation. We also found that gARID1 transactivated the cwp1 promoter through its binding sequences in vivo. Our results suggest that the ARID family has been conserved during evolution and that gARID1 is an important transactivator in regulation of the Giardia cwp1 gene, which is key to Giardia differentiation into cysts. PMID:17244608

Wang, Chih-Hung; Su, Li-Hsin; Sun, Chin-Hung

2007-03-23

184

Proteomics of Secretory and Endocytic Organelles in Giardia lamblia  

Science.gov (United States)

Giardia lamblia is a flagellated protozoan enteroparasite transmitted as an environmentally resistant cyst. Trophozoites attach to the small intestine of vertebrate hosts and proliferate by binary fission. They access nutrients directly via uptake of bulk fluid phase material into specialized endocytic organelles termed peripheral vesicles (PVs), mainly on the exposed dorsal side. When trophozoites reach the G2/M restriction point in the cell cycle they can begin another round of cell division or encyst if they encounter specific environmental cues. They induce neogenesis of Golgi-like organelles, encystation-specific vesicles (ESVs), for regulated secretion of cyst wall material. PVs and ESVs are highly simplified and thus evolutionary diverged endocytic and exocytic organelle systems with key roles in proliferation and transmission to a new host, respectively. Both organelle systems physically and functionally intersect at the endoplasmic reticulum (ER) which has catabolic as well as anabolic functions. However, the unusually high degree of sequence divergence in Giardia rapidly exhausts phylogenomic strategies to identify and characterize the molecular underpinnings of these streamlined organelles. To define the first proteome of ESVs and PVs we used a novel strategy combining flow cytometry-based organelle sorting with in silico filtration of mass spectrometry data. From the limited size datasets we retrieved many hypothetical but also known organelle-specific factors. In contrast to PVs, ESVs appear to maintain a strong physical and functional link to the ER including recruitment of ribosomes to organelle membranes. Overall the data provide further evidence for the formation of a cyst extracellular matrix with minimal complexity. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000694.

Wampfler, Petra B.; Tosevski, Vinko; Nanni, Paolo; Spycher, Cornelia; Hehl, Adrian B.

2014-01-01

185

A novel palmitoyl acyl transferase controls surface protein palmitoylation and cytotoxicity in Giardia lamblia.  

Science.gov (United States)

The intestinal protozoan parasite Giardia lamblia undergoes surface antigenic variation whereby one of a family of structurally related variant-specific surface proteins (VSPs) is replaced in a regulated process by another antigenically distinct VSP. All VSPs are type I membrane proteins that have a conserved hydrophobic sequence terminated by the invariant hydrophilic amino acids, CRGKA. Using transfected Giardia constitutively expressing HA-tagged VSPH7 and incubated with radioactive [3H]palmitate, we demonstrate that the palmitate is attached to the Cys in the conserved CRGKA tail. Surface location of mutant VSPs lacking either the CRGKA tail or its Cys is identical to that of wild-type VSPH7 but non-palmitoylated mutants fail to undergo complement-independent antibody specific cytotoxicity. In addition, membrane localization of non-palmitoylated mutant VSPH7 changes from a pattern similar to rafts to non-rafts. Palmitoyl transferases (PAT), responsible for protein palmitoylation in other organisms, often possess a cysteine-rich domain containing a conserved DHHC motif (DHHC-CRD). An open reading frame corresponding to a putative 50 kDa Giardia PAT (gPAT) containing a DHHC-CRD motif was found in the Giardia genome database. Expression of epitope-tagged gPAT using a tetracycline inducible vector localized gPAT to the plasma membrane, a pattern similar to that of VSPs. Transfection with gPAT antisense producing vectors inhibits gPAT expression and palmitoylation of VSPs in vitro confirming the function of gPAT. These results show that VSPs are palmitoylated at the cysteine within the conserved tail by gPAT and indicate an essential function of palmitoylation in control of VSP-mediated signalling and processing. PMID:16262786

Touz, María C; Conrad, John T; Nash, Theodore E

2005-11-01

186

Influence of Antibodies in Mother’s Milk on Antigenic Variation of Giardia lamblia in the Murine Mother-Offspring Model of Infection  

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In the present study, neonatal ZU.ICR mice and their mothers were infected with trophozoites of Giardia lamblia clone GS/M-83-H7 expressing the variant surface protein (VSP) H7. The infection experiments included a detailed analysis of the specificities of anti-Giardia immunoglobulin A (IgA) antibodies in mother’s milk and a determination of the effects of the milk antibodies on both the growth of the parasite during in vitro cultivation and colonization of the parasite within the intestine...

Sta?ger, S.; Gottstein, B.; Sager, H.; Jungi, T. W.; Mu?ller, N.

1998-01-01

187

Virtual screening of combinatorial libraries across a gene family: in search of inhibitors of Giardia lamblia guanine phosphoribosyltransferase.  

Science.gov (United States)

Parasitic protozoa lack the ability to synthesize purine nucleotides de novo, relying instead on purine salvage enzymes for their survival. Guanine phosphoribosyltransferase (GPRT) from the protozoan parasite Giardia lamblia is a potential target for rational antiparasitic drug design, based on the experimental evidence, which indicates the lack of interconversion between adenine and guanine nucleotide pools. The present study is a continuation of our efforts to use three-dimensional structures of parasitic phosphoribosyltransferases (PRTs) to design novel antiparasitic agents. Two micromolar phthalimide-based GPRT inhibitors were identified by screening the in-house phthalimide library. A combination of structure-based scaffold selection using virtual library screening across the PRT gene family and solid phase library synthesis led to identification of smaller (molecular weight, <300) ligands with moderate to low specificity for GPRT; the best inhibitors, GP3 and GP5, had K(i) values in the 23 to 25 microM range. These results represent significant progress toward the goal of designing potent inhibitors of purine salvage in Giardia parasites. As a second step in this process, altering the phthalimide moiety to optimize interactions in the guanine-binding pocket of GPRT is expected to lead to compounds with promising activity against G. lamblia PRT. PMID:11502531

Aronov, A M; Munagala, N R; Kuntz, I D; Wang, C C

2001-09-01

188

Ozonoterapia en el síndrome de malabsorción intestinal secundario a parasitismo por Giardia lamblia: estudio preliminar  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se estudió el efecto de la ozonoterapia combinada (OLEOZON® oral y ozonoterapia rectal) en el síndrome de malabsorción intestinal, secundario a parasitismo intestinal por Giardia lamblia. Se tomaron 186 pacientes y se formaron 3 grupos de 62 pacientes cada uno. El primer grupo se trató con metronida [...] zol y vitaminoterapia, el segundo con OLEOZON® oral y vitaminoterapia y el tercero con ozonoterapia combinada y vitaminoterapia. Los pacientes fueron evaluados clínicamente por drenaje biliar y biopsia de yeyuno al inicio y final del tratamiento. Se alcanzó una mejoría importante en el tercer grupo (66,1 %), de los cuales, los diagnosticados tempranamente, 40,3 % obtuvo su curación. Se concluyó que la ozonoterapia combinada puede ser eficaz en esta patología. Abstract in english The effect of combined ozone therapy (oral OLEOZON® and rectal ozone therapy) on the syndrome of intestinal malabsorption secondary to intestinal parasitism caused by Giardia lamblia was studied. 186 patients were selected and dividided into 3 groups of 62 patients each. The first group was treated [...] with metronidazole and vitamin therapy, the second with oral OLEOZON® and vitamin therapy, and the third with combined ozone therapy and vitamin therapy. The patients were clinically evaluated by biliary drainage and jejunum biopsy at the beginning and at the end of the treatment. A significant improvement was observed in the third group (66.1 %). Of them, those that had been early diagnosed were cured (40.3 %). It was concluded that combined ozone therapy may be efficient in this pathology.

Nazarina Ivonne, Méndez Pérez; José L., Calunga Fernández; Silvia, Menéndez Cepero.

189

Efecto de un extracto de Petiveria Alliacea Lin sobre el crecimiento de Giardia lamblia in vitro  

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Full Text Available Se evaluó el efecto de un extracto fluido elaborado con un menstruo de Petiveria alliacea (anamú sobre el crecimiento in vitro de Giardia lamblia. Para este ensayo se empleó una cepa aislada en el Instituto de Medicina Tropical "Pedro Kourí", procedente de un paciente infestado. Los cultivos fueron incubados a 37 °C durante 48 h y posteriormente ajustada su concentración a 2 ´105 parásitos por 0,5 mL. Los resultados obtenidos muestran un marcado efecto antigiardiásico, por los altos porcentajes inhibitorios del crecimiento con las 5 concentraciones probadas (17,2; 4,3; 1,075; 0,54 y 0,135 mg/mL, que alcanzó el 96,81 % con la mayor concentración y el 5,03 % con la de 0,135 mg/mL. La concentración media inhibitoria resultó de 2,05 mg/mL.The effect of a fluid extract made with a menstruum of Petiveria alliacea (anamú on the growth of Giardia lamblia in vitro was evaluated. A strain isolated from an infected patient at “Pedro Kouri” Institute of Tropical Medicine was used in this trial. The cultures were incubated at 37 ºC during 48 hours and later their concentrations of 2 x 105 parasites per 0.5 mL were adjusted. The results obtained showed a marked antigiardiasis effect due to the high inhibitory percentages of growth with the 5 tested concentrations (17.2; 4.3; 1.075; 0.54 and 0.135 mg//mL. An effect of 96.81 % was attained with the highest concentration and of 5.03 % with the concentration of 0.135 mg/mL. The mean inhibitory concentration was 2.05 mg/mL.

Aimée Echevarría

2001-09-01

190

Efecto de un extracto de Petiveria Alliacea Lin sobre el crecimiento de Giardia lamblia in vitro  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se evaluó el efecto de un extracto fluido elaborado con un menstruo de Petiveria alliacea (anamú) sobre el crecimiento in vitro de Giardia lamblia. Para este ensayo se empleó una cepa aislada en el Instituto de Medicina Tropical "Pedro Kourí", procedente de un paciente infestado. Los cultivos fueron [...] incubados a 37 °C durante 48 h y posteriormente ajustada su concentración a 2 ´105 parásitos por 0,5 mL. Los resultados obtenidos muestran un marcado efecto antigiardiásico, por los altos porcentajes inhibitorios del crecimiento con las 5 concentraciones probadas (17,2; 4,3; 1,075; 0,54 y 0,135 mg/mL), que alcanzó el 96,81 % con la mayor concentración y el 5,03 % con la de 0,135 mg/mL. La concentración media inhibitoria resultó de 2,05 mg/mL. Abstract in english The effect of a fluid extract made with a menstruum of Petiveria alliacea (anamú) on the growth of Giardia lamblia in vitro was evaluated. A strain isolated from an infected patient at “Pedro Kouri” Institute of Tropical Medicine was used in this trial. The cultures were incubated at 37 ºC during 48 [...] hours and later their concentrations of 2 x 105 parasites per 0.5 mL were adjusted. The results obtained showed a marked antigiardiasis effect due to the high inhibitory percentages of growth with the 5 tested concentrations (17.2; 4.3; 1.075; 0.54 and 0.135 mg//mL). An effect of 96.81 % was attained with the highest concentration and of 5.03 % with the concentration of 0.135 mg/mL. The mean inhibitory concentration was 2.05 mg/mL.

Aimée, Echevarría; Dinorah, Torres Idavoy.

191

Spontaneous chromosome rearrangements in the protozoan Giardia lamblia: estimation of mutation rates.  

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Subcloned lines of the WB strain of Giardia lamblia contain polymorphic ribosomal RNA (rRNA) encoding chromosomes (Le Blancq et al., Nucl. Acids Res. 1991, 19, 4405-4412). We show that in a continuously propagated culture of G.lamblia trophozoites the proportion of trophozoites with rearranged rRNA encoding chromosomes gradually increases, consistent with the high mutation rate of about 1% per cell per division cycle. This conclusion is based on the finding in one experiment that after about ...

1992-01-01

192

ELISA y técnica de sedimentación espontánea para el diagnóstico de infección por Giardia lamblia en muestras fecales de niños de Perú / ELISA and spontaneous sedimentation technique for the diagnosis of Giardia lamblia infection in stool samples of Peruvian children  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish OBJETIVO: Comparar un kit ELISA comercial para coproantígenos y la técnica de sedimentación espontánea en tubo (TSET) para el diagnóstico de Giardia lamblia en muestras fecales de niños de una zona endémica peruana. MATERIAL Y MÉTODOS: Fueron analizadas 174 muestras mediante la TSET y el kit Giardia [...] 2nd Generation ELISA. RESULTADOS: Fueron positivas 51 muestras por ELISA y 49 por TSET. CONCLUSIONES: El ELISA resultó ser altamente sensible y específico, sencillo y rápido; sin embargo, la muy buena concordancia, alta precisión, bajo costo y capacidad para detectar otros enteroparásitos hace que la TSET sea recomendable para el diagnóstico en zonas endémicas del Perú. Abstract in english OBJETIVE: To compare a commercial coproantigen ELISA kit and the technique of spontaneous sedimentation in tube (TSET) for the diagnosis of Giardia lamblia in fecal specimens from children in a Peruvian endemic area. MATERIAL AND METHODS: 174 fecal samples were analyzed by TSET and 2nd Generation Gi [...] ardia ELISA kit. RESULTS: 51 samples were positive by ELISA and 49 by TSET. CONCLUSIONS: The ELISA was highly sensitive and specific, simple and fast. However, the very good agreement, high precision, low cost and ability to detect other intestinal parasites makes use of TSET recommended for laboratory diagnosis in endemic areas of Peru.

Claudia, Rodríguez-Ulloa; Marco, Rivera-Jacinto.

193

ELISA y técnica de sedimentación espontánea para el diagnóstico de infección por Giardia lamblia en muestras fecales de niños de Perú / ELISA and spontaneous sedimentation technique for the diagnosis of Giardia lamblia infection in stool samples of Peruvian children  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish OBJETIVO: Comparar un kit ELISA comercial para coproantígenos y la técnica de sedimentación espontánea en tubo (TSET) para el diagnóstico de Giardia lamblia en muestras fecales de niños de una zona endémica peruana. MATERIAL Y MÉTODOS: Fueron analizadas 174 muestras mediante la TSET y el kit Giardia [...] 2nd Generation ELISA. RESULTADOS: Fueron positivas 51 muestras por ELISA y 49 por TSET. CONCLUSIONES: El ELISA resultó ser altamente sensible y específico, sencillo y rápido; sin embargo, la muy buena concordancia, alta precisión, bajo costo y capacidad para detectar otros enteroparásitos hace que la TSET sea recomendable para el diagnóstico en zonas endémicas del Perú. Abstract in english OBJETIVE: To compare a commercial coproantigen ELISA kit and the technique of spontaneous sedimentation in tube (TSET) for the diagnosis of Giardia lamblia in fecal specimens from children in a Peruvian endemic area. MATERIAL AND METHODS: 174 fecal samples were analyzed by TSET and 2nd Generation Gi [...] ardia ELISA kit. RESULTS: 51 samples were positive by ELISA and 49 by TSET. CONCLUSIONS: The ELISA was highly sensitive and specific, simple and fast. However, the very good agreement, high precision, low cost and ability to detect other intestinal parasites makes use of TSET recommended for laboratory diagnosis in endemic areas of Peru.

Claudia, Rodríguez-Ulloa; Marco, Rivera-Jacinto.

194

Bax function in the absence of mitochondria in the primitive protozoan Giardia lamblia.  

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Bax-induced permeabilization of the mitochondrial outer membrane and release of cytochrome c are key events in apoptosis. Although Bax can compromise mitochondria in primitive unicellular organisms that lack a classical apoptotic machinery, it is still unclear if Bax alone is sufficient for this, or whether additional mitochondrial components are required. The protozoan parasite Giardia lamblia is one of the earliest branching eukaryotes and harbors highly degenerated mitochondrial remnant organelles (mitosomes) that lack a genome. Here we tested whether human Bax expressed in Giardia can be used to ablate mitosomes. We demonstrate that these organelles are neither targeted, nor compromised, by Bax. However, specialized compartments of the regulated secretory pathway are completely ablated by Bax. As a consequence, maturing cyst wall proteins that are sorted into these organelles are released into the cytoplasm, causing a developmental arrest and cell death. Interestingly, this ectopic cargo release is dependent on the carboxy-terminal 22 amino acids of Bax, and can be prevented by the Bax-inhibiting peptide Ku70. A C-terminally truncated Bax variant still localizes to secretory organelles, but is unable to permeabilize these membranes, uncoupling membrane targeting and cargo release. Even though mitosomes are too diverged to be recognized by Bax, off-target membrane permeabilization appears to be conserved and leads to cell death completely independently of mitochondria. PMID:17534438

Hehl, Adrian B; Regos, Attila; Schraner, Elisabeth; Schneider, André

2007-01-01

195

High-speed microscopic imaging of flagella motility and swimming in Giardia lamblia trophozoites  

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We report, in this paper, several findings about the swimming and attachment mechanisms of Giardia lamblia trophozoites. These data were collected using a combination of a high-contrast CytoViva imaging system and a particle image velocimetry camera, which can capture images at speeds greater than 800 frames/s. Using this system, we discovered that, during rapid swimming of Giardia trophozoites, undulations of the caudal region contributed to forward propulsion combined with the beating of th...

Lenaghan, Scott C.; Davis, Corinne A.; Henson, William R.; Zhang, Zhili; Zhang, Mingjun

2011-01-01

196

Evaluation Of Cytokines Changes In Patients Infected With Giardia lamblia In Comparison With Healthy Subjects  

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Full Text Available Background and Aim: Human Giardisis infection is caused by the flagellate protozoa. Giardia lamblia, which lives in the small intestine, causing damage and may also cause gastrointestinal symptoms. This parasitic disease has a worldwide distribution and prevalence varies from 5% to 30%. The role of both humeral and cellular immune response in the host defense against parasites has proven. Since an immune response is directly affected by cytokine, study of cytokines changes in patients with giardiosis is of particular importance. Materials and Methods: In this study the serum levels of IL-2 - 4 - 6 to 17 and 23 in patients and healthy subjects were measured and compared. Fasting blood samples were taken from the volunteers, ELISA was performed to measure cytokines. Results: In this study, the amount of IL-2 and IL-6 in infected patients was significantly more than the controls, but IL-4 levels were significantly lower in infected individuals (P=0.0001. Also for the first time in people with giardiasis IL-17 and IL-23 was measured and there was a significant aifference in these cytokines between the infected patients healthy controls(respectively P=0.044 and P=0.03 Conclusion: Host defense response against parasitic infections, is directly and affected by cytokines. Increased interleukin 2, 6, 17 and 23 in patients with Giardiosis was probably caused by immune response and local intestinal inflammation.

Mitra Zarebavani

2012-12-01

197

Detection of anti-Giardia lamblia serum antibody among children of day care centers / Detecção de anticorpos séricos anti-Giardia lamblia em crianças de creches  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVOS: Detectar anticorpos séricos anti-Giardia lamblia entre crianças atendidas em creches e estimar a freqüência de infecção por Giardia lamblia em área endêmica. MÉTODOS: Foram coletadas três amostras de fezes de cada uma das 147 crianças de três creches da rede municipal de Botucatu, SP, com [...] idade variando de 0 a 6 anos, e as amostras foram processadas pelos métodos de sedimentação espontânea e flutuação pelo sulfato de zinco. Amostras de sangue foram obtidas da polpa digital, coletadas em papel de filtro e testadas pelos métodos de imunofluorescência indireta (IFI) e de reação imunoenzimática (Elisa) para pesquisa de IgG anti-Giardia. RESULTADOS E CONCLUSÕES: De um total de 147 crianças, 93 (63,3%) apresentaram cistos de Giardia nas fezes. Dos 147 eluatos testados, 93 (63,3%) e 100 (68%) foram positivos para Giardia em IFI e em Elisa, respectivamente. A sensibilidade de IFI foi de 82% e de Elisa, 72%. Contudo, Elisa foi menos específica (39%) do que IFI (70%). A imunofluorescência indireta apresentou maior concordância com o exame de fezes do que Elisa. Abstract in english OBJETIVES: To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas. METHODS: Three separate stool specimens and filter paper blood samples were collecte [...] d from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for Giardia IgG. RESULTS AND CONCLUSIONS: Of 147 individuals tested, 93 (63.3%) showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3%) and 100 (68%) samples , respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39%) than IIF (70%). IIF also showed a higher concordance with microscopic examination than ELISA.

Guimarães, Semíramis; Sogayar, Maria Inês L.

198

Detection of anti-Giardia lamblia serum antibody among children of day care centers / Detecção de anticorpos séricos anti-Giardia lamblia em crianças de creches  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: English Abstract in portuguese OBJETIVOS: Detectar anticorpos séricos anti-Giardia lamblia entre crianças atendidas em creches e estimar a freqüência de infecção por Giardia lamblia em área endêmica. MÉTODOS: Foram coletadas três amostras de fezes de cada uma das 147 crianças de três creches da rede municipal de Botucatu, SP, com [...] idade variando de 0 a 6 anos, e as amostras foram processadas pelos métodos de sedimentação espontânea e flutuação pelo sulfato de zinco. Amostras de sangue foram obtidas da polpa digital, coletadas em papel de filtro e testadas pelos métodos de imunofluorescência indireta (IFI) e de reação imunoenzimática (Elisa) para pesquisa de IgG anti-Giardia. RESULTADOS E CONCLUSÕES: De um total de 147 crianças, 93 (63,3%) apresentaram cistos de Giardia nas fezes. Dos 147 eluatos testados, 93 (63,3%) e 100 (68%) foram positivos para Giardia em IFI e em Elisa, respectivamente. A sensibilidade de IFI foi de 82% e de Elisa, 72%. Contudo, Elisa foi menos específica (39%) do que IFI (70%). A imunofluorescência indireta apresentou maior concordância com o exame de fezes do que Elisa. Abstract in english OBJETIVES: To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas. METHODS: Three separate stool specimens and filter paper blood samples were collecte [...] d from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) for Giardia IgG. RESULTS AND CONCLUSIONS: Of 147 individuals tested, 93 (63.3%) showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3%) and 100 (68%) samples , respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39%) than IIF (70%). IIF also showed a higher concordance with microscopic examination than ELISA.

Guimarães, Semíramis; Sogayar, Maria Inês L.

199

Detection of anti-Giardia lamblia serum antibody among children of day care centers Detecção de anticorpos séricos anti-Giardia lamblia em crianças de creches  

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Full Text Available OBJETIVES: To detect anti-Giardia lamblia serum antibodies in healthy children attending public day care centers and to assess serological tests as tools for estimating the prevalence of G. lamblia in endemic areas. METHODS: Three separate stool specimens and filter paper blood samples were collected from 147 children ranging from 0 to 6 years old. Each stool sample was processed using spontaneous sedimentation and zinc sulfate flotation methods. Blood samples were tested by indirect immunofluorescence (IIF and enzyme-linked immunosorbent assay (ELISA for Giardia IgG. RESULTS AND CONCLUSIONS: Of 147 individuals tested, 93 (63.3% showed Giardia cysts in their feces. Using IIF and ELISA, serum antibodies were detected in 93 (63.3% and 100 (68% samples , respectively. Sensitivity of IIF and ELISA was 82% and 72%, respectively. However, ELISA revealed to be less specific (39% than IIF (70%. IIF also showed a higher concordance with microscopic examination than ELISA.OBJETIVOS: Detectar anticorpos séricos anti-Giardia lamblia entre crianças atendidas em creches e estimar a freqüência de infecção por Giardia lamblia em área endêmica. MÉTODOS: Foram coletadas três amostras de fezes de cada uma das 147 crianças de três creches da rede municipal de Botucatu, SP, com idade variando de 0 a 6 anos, e as amostras foram processadas pelos métodos de sedimentação espontânea e flutuação pelo sulfato de zinco. Amostras de sangue foram obtidas da polpa digital, coletadas em papel de filtro e testadas pelos métodos de imunofluorescência indireta (IFI e de reação imunoenzimática (Elisa para pesquisa de IgG anti-Giardia. RESULTADOS E CONCLUSÕES: De um total de 147 crianças, 93 (63,3% apresentaram cistos de Giardia nas fezes. Dos 147 eluatos testados, 93 (63,3% e 100 (68% foram positivos para Giardia em IFI e em Elisa, respectivamente. A sensibilidade de IFI foi de 82% e de Elisa, 72%. Contudo, Elisa foi menos específica (39% do que IFI (70%. A imunofluorescência indireta apresentou maior concordância com o exame de fezes do que Elisa.

Semíramis Guimarães

2002-02-01

200

The Study of the Multilayer Filtration Process Efficiency on Giardia lamblia Elimination in Isfahan Water Treatment Plant  

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Full Text Available Introduction: Giardia lamblia is a waterborne highly infectious protozoan parasite capable of causing gastrointestinal illness. The multilayer filtration is used in many applications such as turbidity removes from surface waters and Bacteria, Viruses and protozoan removes. This study was investigated in full-scale the efficiency of filtration process during water treatment that remove Giardia cyst in water at Isfahan province. Materials and methods: We used Information Collection Rule method (ICR. In this method the polypropylene yarn-wound cartridge filter for isolation of these parasites was examined and followed by elution, sample concentration, flotation by percoll-sucrose solution and immunofluorescence antibody (IFA staining to recognize them. Results: Result showed that three layer filtration had a maximum 2.3 log10 for remove Giardia cyst. Cysts removal in water filtration is likely to be comparable to the efficiency of turbidity. Efficiency removal was 99.5% for Giardia and 92.7% for turbidity in filtration stage. We detected 0.2 cyst per 100 liter and per 100 liter in filtered water. This observation is according to U.S.EPA standards. The number of cysts were more in high pH samples. Discussion and conclusion: Analysis of physical processes of treatment water in Isfahan plant configurations showed that granular filters (include sand, anthracite and garnet filter were more likely to have effluence in removal cysts than dual filters.

Zahra Mosaviyan

2014-04-01

 
 
 
 
201

Can Giardia lamblia infection lower the risk of acute diarrhea among preschool children?  

Science.gov (United States)

There are inconsistent findings concerning the role of Giardia lamblia in pediatric diarrhea. A prospective cohort study of the incidence of acute diarrhea among Israeli Arab preschool children offered the opportunity to examine the association between G. lamblia infection (at baseline) and subsequent diarrhea. Following baseline screening by light microscopy for the presence of Giardia in their stools, a cohort was assembled of 142 children who were followed between October 2003 and August 2004 for the incidence of diarrhea. Surveillance was performed through maternal interviews. At baseline, 21 children tested Giardia-positive. During the prospective surveillance, acute diarrhea occurred less often among Giardia-positive children (9.5%) than among children who were not infected with Giardia (26.5%). G. lamblia infection was associated with lower risk of acute diarrhea; adjusted odds ratio of 0.18 (95% confidence interval 0.04-0.93) (p = 0.041). This prospective study provides additional evidence that Giardia may lower the risk of subsequent acute diarrhea among preschool children. PMID:24158113

Muhsen, Khitam; Cohen, Dani; Levine, Myron M

2014-04-01

202

Rapid and sensitive detection of Giardia lamblia using a piezoelectric cantilever biosensor in finished and source waters.  

Science.gov (United States)

The current method for detecting the waterborne parasite Giardia lamblia is tedious and requires a preconcentration step. We show for the first time a piezoelectric-excited millimeter-sized cantilever (PEMC) biosensor immobilized with a monoclonal antibody against G. lamblia that exhibits selective and sensitive detection of G. lamblia cysts in several water matrixes (buffer, tap, and river water) at a detection limit of 1-10 cysts/mL without a preconcentration step. The PEMC sensor is a resonance-based device that functions at a high-order mode near 1 MHz. The antibody-immobilized sensor was exposed to 1-10,000 G. lamblia cysts/mL samples in a flow arrangement. When the cysts bind to the antibody on the sensor, the resonant frequency of the cantilever sensor decreases and is recorded continuously. Positive confirmation of sensor detection responses was obtained by environmental scanning electron microscope of sensor surface after detection experiments. Higher sample flow rates (0.5-5.0 mL/min) gave higher sensor detection response. Detecting as few as 10 cysts per mL was achieved in all three water matrixes tested, and significant sensor response was obtained in 15 min. We also show the feasibility of analyzing at a low concentration of 1 cyst/mL in a one liter sample at a high flow rate of 5 mL/min. PMID:20121270

Xu, Sen; Mutharasan, Raj

2010-03-01

203

Effects of bile and bile salts on growth and membrane lipid uptake by Giardia lamblia. Possible implications for pathogenesis of intestinal disease.  

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We have shown previously that ox and pig bile accelerate in vitro growth of Giardia lamblia. We have now investigated the possible mechanisms by which mammalian biles promote parasite growth. Growth effects of (a) ox, pig, guinea pig, and human biles, (b) pure bile salts, and (c) egg and soybean lecithins were studied in the presence of a lecithin-containing growth medium. Individually, dilute native bile and pure sodium taurocholate (TC), glycocholate (GC), and taurodeoxycholate (TDC) promot...

Farthing, M. J.; Keusch, G. T.; Carey, M. C.

1985-01-01

204

Development and testing of a filter system for isolation of Giardia lamblia cysts from water.  

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An inexpensive, practical, and reliable method for isolation of Giardia lamblia cysts from potable and environmental water has been developed from commercially available components. This system was successfully used to isolate cysts from well water associated with a family outbreak of giardiasis.

Hausler, W. J.; Davis, W. E.; Moyer, N. P.

1984-01-01

205

EXPERIMENTAL INFECTION OF MONGREL DOGS WITH 'GIARDIA LAMBLIA' CYSTS AND CULTURED TROPHOZOITES  

Science.gov (United States)

In light of recent epidemiologic data implicating wild and domestic animals in the transmission of giardiasis, a study was undertaken to determine whether mongrel dogs could be infected with Giardia lamblia. After careful screening by stool examination (a minimum of six stools ex...

206

DETERMINATION OF GIARDIA LAMBLIA CYST INFECTIVE DOSE FOR THE MONGOLIAN GERBIL (MERIONES UNQUICULATUS)  

Science.gov (United States)

The purpose of this study was to determine the I.D.50 for Giardia lamblia (CDC:0284:1) cysts in Mongolian gerbils (Meriones unquiculatus) and compare it to human infectivity data. ysts were purified from Mongolian gerbil feces and diluted to produce inocula for each dosage group....

207

Small-intestinal factors promote encystation of Giardia lamblia in vitro.  

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Bile salts and fatty acids stimulated differentiation of cultured Giardia lamblia trophozoites into water-resistant cysts at the slightly alkaline pH of the small intestinal lumen. Maximum encystation occurred at pH 7.8. Thus, specific small-intestinal factors may influence encystation in vivo as well as in vitro.

1988-01-01

208

INACTIVATION OF GERBIL-CULTURED GIARDIA LAMBLIA CYSTS BY FREE CHLORINE  

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Giardia lamblia cysts were harvested from Mongolian gerbils and exposed to free chlorine in buffered water at pH 5, 7, and 9 at 15 degrees C. he contact times required to obtained a 2-log reduction in cyst survival (i.e., a 99% kill) were interpolated from survival curves generat...

209

Structural basis for inactivation of Giardia lamblia carbamate kinase by disulfiram.  

Science.gov (United States)

Carbamate kinase from Giardia lamblia is an essential enzyme for the survival of the organism. The enzyme catalyzes the final step in the arginine dihydrolase pathway converting ADP and carbamoyl phosphate to ATP and carbamate. We previously reported that disulfiram, a drug used to treat chronic alcoholism, inhibits G. lamblia CK and kills G. lamblia trophozoites in vitro at submicromolar IC50 values. Here, we examine the structural basis for G. lamblia CK inhibition of disulfiram and its analog, thiram, their activities against both metronidazole-susceptible and metronidazole-resistant G. lamblia isolates, and their efficacy in a mouse model of giardiasis. The crystal structure of G. lamblia CK soaked with disulfiram revealed that the compound thiocarbamoylated Cys-242, a residue located at the edge of the active site. The modified Cys-242 prevents a conformational transition of a loop adjacent to the ADP/ATP binding site, which is required for the stacking of Tyr-245 side chain against the adenine moiety, an interaction seen in the structure of G. lamblia CK in complex with AMP-PNP. Mass spectrometry coupled with trypsin digestion confirmed the selective covalent thiocarbamoylation of Cys-242 in solution. The Giardia viability studies in the metronidazole-resistant strain and the G. lamblia CK irreversible inactivation mechanism show that the thiuram compounds can circumvent the resistance mechanism that renders metronidazole ineffectiveness in drug resistance cases of giardiasis. Together, the studies suggest that G. lamblia CK is an attractive drug target for development of novel antigiardial therapies and that disulfiram, an FDA-approved drug, is a promising candidate for drug repurposing. PMID:24558036

Galkin, Andrey; Kulakova, Liudmila; Lim, Kap; Chen, Catherine Z; Zheng, Wei; Turko, Illarion V; Herzberg, Osnat

2014-04-11

210

Selective condensation drives partitioning and sequential secretion of cyst wall proteins in differentiating Giardia lamblia.  

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Controlled secretion of a protective extracellular matrix is required for transmission of the infective stage of a large number of protozoan and metazoan parasites. Differentiating trophozoites of the highly minimized protozoan parasite Giardia lamblia secrete the proteinaceous portion of the cyst wall material (CWM) consisting of three paralogous cyst wall proteins (CWP1-3) via organelles termed encystation-specific vesicles (ESVs). Phylogenetic and molecular data indicate that Diplomonads have lost a classical Golgi during reductive evolution. However, neogenesis of ESVs in encysting Giardia trophozoites transiently provides basic Golgi functions by accumulating presorted CWM exported from the ER for maturation. Based on this "minimal Golgi" hypothesis we predicted maturation of ESVs to a trans Golgi-like stage, which would manifest as a sorting event before regulated secretion of the CWM. Here we show that proteolytic processing of pro-CWP2 in maturing ESVs coincides with partitioning of CWM into two fractions, which are sorted and secreted sequentially with different kinetics. This novel sorting function leads to rapid assembly of a structurally defined outer cyst wall, followed by slow secretion of the remaining components. Using live cell microscopy we find direct evidence for condensed core formation in maturing ESVs. Core formation suggests that a mechanism controlled by phase transitions of the CWM from fluid to condensed and back likely drives CWM partitioning and makes sorting and sequential secretion possible. Blocking of CWP2 processing by a protease inhibitor leads to mis-sorting of a CWP2 reporter. Nevertheless, partitioning and sequential secretion of two portions of the CWM are unaffected in these cells. Although these cysts have a normal appearance they are not water resistant and therefore not infective. Our findings suggest that sequential assembly is a basic architectural principle of protective wall formation and requires minimal Golgi sorting functions. PMID:20386711

Konrad, Christian; Spycher, Cornelia; Hehl, Adrian B

2010-04-01

211

An unusual triosephosphate isomerase from the early divergent eukaryote Giardia lamblia.  

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Recombinant triosephosphate isomerase from the parasite Giardia lamblia (GlTIM) was characterized and immunolocalized. The enzyme is distributed uniformly throughout the cytoplasm. Size exclusion chromatography of the purified enzyme showed two peaks with molecular weights of 108 and 55 kDa. Under reducing conditions, only the 55-kDa protein was detected. In denaturing gel electrophoresis without dithiothreitol, the enzyme showed two bands with molecular weights of 28 and 50 kDa; with dithiotretitol, only the 28-kDa protein was observed. These data indicate that GlTIM may exist as a tetramer or a dimer and that, in the former, the two dimers are covalently linked by disulfide bonds. The kinetics of the dimer were similar to those of other TIMs. The tetramer exhibited half of the kcat of the dimer without changes in the Km. Studies on the thermal stability and the apparent association constants between monomers showed that the tetramer was slightly more stable than the dimer. This finding suggests the oligomerization is not related to enzyme thermostability as in Thermotoga maritima. Instead, it could be that oligomerization is related to the regulation of catalytic activity in different states of the life cycle of this mesophilic parasite. PMID:15146481

López-Velázquez, Gabriel; Molina-Ortiz, Dora; Cabrera, Nallely; Hernández-Alcántara, Gloria; Peon-Peralta, Jorge; Yépez-Mulia, Lilian; Pérez-Montfort, Ruy; Reyes-Vivas, Horacio

2004-06-01

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Crystal structure of a macrophage migration inhibitory factor from Giardia lamblia  

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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 ?/? fold consisting of a four-stranded ?-sheet with two anti-parallel ?-helices packed against a face of the ?-sheet. An additional short ?-strand aligns anti-parallel to ?4 of the ?-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 ?-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.

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

2013-06-15

213

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

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Full Text Available Abstract 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.

Williams Christopher W

2011-11-01

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Inducible nitric oxide synthase in duodenum of children with Giardia lamblia infection.  

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Full Text Available The investigation were performed on children with Giardia lamblia infection, diagnosed on the basis of positive stool tests for Giardia antigen (Elisa or by microscopical detection of trophozoites in duodenal fluid. In duodenal biopsies morphological studies and immunohistochemical reaction for inducible nitric oxide synthase (iNOS were performed. The control group was made up of duodenal tissue of children with excluded giardiasis and inflammation of the upper part of gastrointestinal tract. The duodenal biopsies from children without Giardia lamblia infection were found to have a high immunoreactivity for iNOS in enterocytes, the cells of intestinal crypts, endothelial cells of vessels and connective tissue cells of lamina propria. In children with giardiasis: in some biopsies the expression of iNOS was as high as in control group, in others was weaker detectable and the shortening of intestinal villi was seen. There were also duodenal biopsies with the lack of immunoreactivity for iNOS, with shorter villi and a large amount of mucus in the intestinal epithelium. Beside of goblet cells, also enterocytes were loaded with mucus. The pathological changes may cause malabsorption and also may have a negative influence on the defense of the intestinal wall against Giardia lamblia infection. The different morphological and immunohistochemical results in the duodenum of children with giardiasis can elucidate a variety of clinical symptoms from asymptomatic to severe infection.

Agnieszka Kolasa

2010-08-01

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In vitro inhibition of Giardia lamblia and Trichomonas vaginalis growth by bithionol, dichlorophene, and hexachlorophene.  

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Bithionol, dichlorophene, and hexachlorophene, which are used in treating some helminthic infections, killed trophozoites of Giardia lamblia and Trichomonas vaginalis in modified BI-S-33 and Asami media, respectively. Virtually all G. lamblia and T. vaginalis cells were killed within 24 h with a 0.42 mM concentration of these compounds, except that 0.93 mM dichlorophene was required for sterilizing T. vaginalis in the same period. In modified BI-S-33 and Asami media from which bovine and huma...

Takeuchi, T.; Kobayashi, S.; Tanabe, M.; Fujiwara, T.

1985-01-01

216

Cysteine-dependent zinc binding by membrane proteins of Giardia lamblia.  

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The abundant, highly variable surface proteins (VSPs) which cover the surface of Giardia lamblia trophozoites compose a group of extremely cysteine (C)-rich proteins in which more than half of the cysteines are in the motif CXXC. Because of the constancy of these features among the known VSPs and the prominence of cysteine and particularly CXXC in proteins that bind zinc and other metals, we asked whether G. lamblia VSPs bind zinc in vitro. VSPs are the major protein component of Triton X-114...

Zhang, Y. Y.; Aley, S. B.; Stanley, S. L.; Gillin, F. D.

1993-01-01

217

Giardia lamblia expresses a proteobacterial-like DnaK homolog.  

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We identified a novel gene encoding molecular chaperone HSP70 in the amitochondriate parasite Giardia lamblia. The predicted protein is similar to bacterial DnaK and mitochondrial HSP70s. The gene is transcribed and translated at a constant level during trophozoite growth and encystation. Alignment of the sequence with a data set of cytosolic, endoplasmic reticulum (ER), mitochondrial, and DnaK HSP70 homologs indicated that the sequence was extremely divergent and contained insertions unique to giardial HSP70s. Phylogenetic analyses demonstrated that this sequence was distinct from the cytosolic and ER forms and was most similar to proteobacterial and mitochondrial DnaKs. However, a specific relationship with the alpha proteobacterial and mitochondrial sequences was not strongly supported by phylogenetic analyses of this data set, in contrast to similar analyses of cpn60. These data neither confirm nor reject the possibility that this gene is a relic of secondary mitochondrial loss; they leave open the possibility that it was acquired in a separate endosymbiotic event. PMID:11264404

Morrison, H G; Roger, A J; Nystul, T G; Gillin, F D; Sogin, M L

2001-04-01

218

Allelic sequence heterozygosity in single Giardia parasites  

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Full Text Available Abstract Background Genetic heterogeneity has become a major inconvenience in the genotyping and molecular epidemiology of the intestinal protozoan parasite Giardia intestinalis, in particular for the major human infecting genotype, assemblage B. Sequence-based genotyping of assemblage B Giardia from patient fecal samples, where one or several of the commonly used genotyping loci (beta-giardin, triosephosphate isomerase and glutamate dehydrogenase are implemented, is often hampered due to the presence of sequence heterogeneity in the sequencing chromatograms. This can be due to allelic sequence heterozygosity (ASH and /or co-infections with parasites of different assemblage B sub-genotypes. Thus, two important questions have arisen; i does ASH occur at the single cell level, and/or ii do multiple sub-genotype infections commonly occur in patients infected with assemblage B, G. intestinalis isolates? Results We used micromanipulation in order to isolate single Giardia intestinalis, assemblage B trophozoites (GS isolate and cysts from human patients. Molecular analysis at the tpi loci of trophozoites from the GS lineage indicated that ASH is present at the single cell level. Analyses of assemblage B Giardia cysts from clinical samples at the bg and tpi loci also indicated ASH at the single cell level. Additionally, alignment of sequence data from several different cysts that originated from the same patient yielded different sequence patterns, thus suggesting the presence of multiple sub-assemblage infections in congruence with ASH within the same patient. Conclusions Our results conclusively show that ASH does occur at the single cell level in assemblage B Giardia. Furthermore, sequence heterogeneity generated during sequence-based genotyping of assemblage B isolates may possess the complexity of single cell ASH in concurrence with co-infections of different assemblage B sub-genotypes. These findings explain the high abundance of sequence heterogeneity commonly found when performing sequence based genotyping of assemblage B Giardia, and illuminates the necessity of developing new G. intestinalis genotyping tools.

Ankarklev Johan

2012-05-01

219

Axenic cultivation and characterization of Giardia lamblia isolated from humans in Korea  

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Inoculating of human fecal cysts to suckling Mongolian gerbils, two Giardia lamblia isolates, K1 and K2, were established as axenic cultures. Using this in vitro culture, both isolates were characterized as a "medium-rate grower" upon its growth pattern. These two Giardia isolates were grouped by using two genetic analysis. With genetic analysis of SSU-rDNA sequences, both K1 and K2 were found as members of Hopkins' group 1, despite some nucleotide differences noticed in K1 (5 differences/292...

Park, Soon-jung; Yong, Tai-soon; Yang, Hye-won; Lee, Du-ho; Lee, Kyungwon

1999-01-01

220

Experimental Verification of the Identity of Variant-Specific Surface Proteins in Giardia lamblia Trophozoites  

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The cell membrane of a Giardia lamblia trophozoite is covered with a single species of variant-specific surface protein (VSP) that is replaced by another VSP every 6 to 13 generations of cell growth, possibly for an evasion of host immunity. Experimentally, only six VSP species have been verified to localize to the cell membrane thus far. By assuming that VSP contains multiple CXXC motifs, 219 vsp genes were annotated in GiardiaDB of the WB isolate. By further assuming that VSP possesses both...

Li, Wei; Saraiya, Ashesh A.; Wang, Ching C.

2013-01-01

 
 
 
 
221

Enzyme immunoassay for detection of Giardia lamblia cyst antigens in formalin-fixed and unfixed human stool.  

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An antigen-capture enzyme-linked immunosorbent assay employing rabbit and mouse antisera to Giardia lamblia cyst antigens was developed for the diagnosis of Giardia infection through detection of G. lamblia-specific stool antigens in cell-free aqueous eluates of human stool. This is the first report of the use of anti-cyst antibodies in an enzyme immunoassay for G. lamblia. The assay gave a positive result with 54 of 59 stools from patients with symptomatic, clinically diagnosed giardiasis, g...

Stibbs, H. H.; Samadpour, M.; Manning, J. F.

1988-01-01

222

Ozonoterapia en el síndrome de malabsorción intestinal secundario a parasitismo por Giardia lamblia: estudio preliminar  

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Se estudió el efecto de la ozonoterapia combinada (OLEOZON® oral y ozonoterapia rectal) en el síndrome de malabsorción intestinal, secundario a parasitismo intestinal por Giardia lamblia. Se tomaron 186 pacientes y se formaron 3 grupos de 62 pacientes cada uno. El primer grupo se trató con metronidazol y vitaminoterapia, el segundo con OLEOZON® oral y vitaminoterapia y el tercero con ozonoterapia combinada y vitaminoterapia. Los pacientes fueron evaluados clínicamente por drenaje bilia...

2003-01-01

223

IDENTIFICATION OF GROWTH INHIBITING COMPOUNDS IN A GIARDIA LAMBLIA HIGH-THROUGHPUT SCREEN  

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Giardia lamblia is one of the most common eukaryotic pathogens and is classified by the CDC as a category B agent of bioterrorism. In a departure from more traditional research focused on specific pathways or molecules, we have developed a high-throughput assay for screening libraries of small compounds for inhibitors and enhancers of trophozoite multiplication. Following a 24-h period of culture in 384-well plates in the presence of compounds, trophozoites were fixed, stained and enumerated....

Santiago, Ruben Bonilla; Wu, Zijin; Zhang, Linghui; Widmer, Giovanni

2008-01-01

224

Dual acylation accounts for the localization of {alpha}19-giardin in the ventral flagellum pair of Giardia lamblia.  

Science.gov (United States)

A Giardia-specific protein family denominated as alpha-giardins, represents the major protein component, besides tubulin, of the cytoskeleton of the human pathogenic parasite Giardia lamblia. One of its members, alpha19-giardin, carries an N-terminal sequence extension of MGCXXS, which in many proteins serves as a target for dual lipid conjugation: myristoylation at the glycine residue after removal of the methionine and palmitoylation at the cysteine residue. As the first experimental evidence of a lipid modification, we found alpha19-giardin to be associated with the membrane fraction of disrupted trophozoites. After heterologous coexpression of alpha19-giardin with giardial N-myristoyltransferase (NMT) in Escherichia coli, we found the protein in a myristoylated form. Additionally, after heterologous expression together with the palmitoyl transferase Pfa3 in Saccharomyces cerevisiae, alpha19-giardin associates with the membrane of the main vacuole. Immunocytochemical colocalization studies on wild-type Giardia trophozoites with tubulin provide evidence that alpha19-giardin exclusively localizes to the ventral pair of the giardial flagella. A mutant in which the putatively myristoylated N-terminal glycine residue was replaced by alanine lost this specific localization. Our findings suggest that the dual lipidation of alpha19-giardin is responsible for its specific flagellar localization. PMID:19684283

Saric, Mirela; Vahrmann, Anke; Niebur, Daniela; Kluempers, Verena; Hehl, Adrian B; Scholze, Henning

2009-10-01

225

SUMOylation in Giardia lamblia: A Conserved Post-Translational Modification in One of the Earliest Divergent Eukaryotes  

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Full Text Available Post-translational modifications are able to regulate protein function and cellular processes in a rapid and reversible way. SUMOylation, the post-translational modification of proteins by the addition of SUMO, is a highly conserved process that seems to be present in modern cells. However, the mechanism of protein SUMOylation in earlier divergent eukaryotes, such as Giardia lamblia, is only starting to become apparent. In this work, we report the presence of a single SUMO gene encoding to SUMO protein in Giardia. Monoclonal antibodies against recombinant Giardia SUMO protein revealed the cytoplasmic localization of native SUMO in wild-type trophozoites. Moreover, the over-expression of SUMO protein showed a mainly cytoplasmic localization, though also neighboring the plasma membrane, flagella, and around and even inside the nuclei. Western blot assays revealed a number of SUMOylated proteins in a range between 20 and 120 kDa. The genes corresponding to putative enzymes involved in the SUMOylation pathway were also explored. Our results as a whole suggest that SUMOylation is a process conserved in the eukaryotic lineage, and that its study is significant for understanding the biology of this interesting parasite and the role of post-translational modification in its evolution.

Andrea S. Rópolo

2012-07-01

226

Modified PEHPS Medium as an Alternative for the In Vitro Culture of Giardia lamblia  

Science.gov (United States)

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 × 103 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 × 105Giardia 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.

Vargas-Villarreal, Javier; Mata-Cardenas, Benito D.; Hernandez-Garcia, Magda E.; Garza-Gonzalez, Jesus N.; De La Garza-Salinas, Laura H.; Gonzalez-Salazar, Francisco

2014-01-01

227

Modified PEHPS Medium as an Alternative for the In Vitro Culture of Giardia lamblia.  

Science.gov (United States)

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. PMID:24982905

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

228

Identification of an immunogenic protein of Giardia lamblia using monoclonal antibodies generated from infected mice  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and [...] characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.

Jael, Quintero; Diana Carolina, Figueroa; Rafael, Barcelo; Linda, Breci; Humberto, Astiazaran-Garcia; Lucila, Rascon; Ramon, Robles-Zepeda; Adriana, Garibay-Escobar; Enrique, Velazquez-Contreras; Gloria Leon, Avila; Jose Manuel, Hernandez-Hernandez; Carlos, Velazquez.

229

Numerous fragmented spliceosomal introns, AT-AC splicing, and an unusual dynein gene expression pathway in Giardia lamblia.  

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Spliceosomal introns are hallmarks of eukaryotic genomes, dividing coding regions into separate exons, which are joined during mRNA intron removal catalyzed by the spliceosome. With few known exceptions, spliceosomal introns are cis-spliced, that is, removed from one contiguous pre-mRNA transcript. The protistan intestinal parasite Giardia lamblia exhibits one of the most reduced eukaryotic genomes known, with short intergenic regions and only four known spliceosomal introns. Our genome-wide search for additional introns revealed four unusual cases of spliceosomal intron fragmentation, with consecutive exons of conserved protein-coding genes being dispersed to distant genomic sites. Independent transcripts are trans-spliced to yield contiguous mature mRNAs. Most strikingly, a dynein heavy chain subunit is both interrupted by two fragmented introns and also predicted to be assembled as two separately translated polypeptides, a remarkably complex expression pathway for a nuclear-encoded sequence. For each case, we observe extensive base-pairing potential between intron halves. This base pairing provides both a rationale for the in vivo association of independently transcribed mRNAs transcripts and the apparent specificity of splicing. Similar base-pairing potential in two cis-spliced G. lamblia introns suggests an evolutionary pathway whereby intron fragmentation of cis-spliced introns is permissible and a preliminary evolutionary step to complete gene fission. These results reveal remarkably complex genome dynamics in a severely genomically reduced parasite. PMID:21482665

Roy, Scott W; Hudson, Andrew J; Joseph, Joella; Yee, Janet; Russell, Anthony G

2012-01-01

230

Comparación de métodos de lisis y extracción de ADN de trofozoítos de Giardia lamblia COMPARISON OF LYSIS METHODS AND DNA EXTRACTION OF GIARDIA LAMBLIA TROPHOZOITES  

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Full Text Available Se evaluó la eficiencia de procedimientos de lisis y tratamientos de extracción de ADN de trofozoítos de Giardia lamblia respecto a la eficiencia de ruptura, cantidad y pureza de ADN, además de los tiempos de procesamiento y costos. Se testearon cinco métodos de lisis (agua destilada y calor; agua destilada, calor y proteinasa K; buffer de lisis D; buffer de lisis E y un kit comercial y tres métodos de purificación de ADN (fenol:cloroformo: isoamílico; Chelex 100 y un kit comercial. Los datos obtenidos se analizaron estadísticamente. La combinación de buffer de lisis E y Chelex fue un método simple y económico, que produjo alto rendimiento de ADN con baja pureza. Ella técnica comercial fue un método simple, más costoso que produjo bajas cantidades de ADN con un nivel de pureza apropiado para estudios molecularesThe efficiency of lysis procedures and DNA purification treatments of Giardia lamblia trophozoites were evaluated regarding the breaking-up efficiency, quantity and pureness of DNA, processing time and costs. Five lysis methods (distilled water and heating; distilled water, heating and proteinase K; buffer D Lysis; buffer E lysis, and commercial kit, and three DNA purification methods (phenol:chloroform:isoamilic, Chelex 100 and commercial kit were tested. The obtained data were statistically analyzed. The buffer E lysis and Chelex combination was simple and economic method which produced high DNA performance with low pureness. Commercial kit was simple and expensive method which generated low yields of DNA with appropriate purity level for molecular analysis

NORA B MOLINA

2006-12-01

231

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

Science.gov (United States)

Alpha-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 alpha-11 giardin under two different conditions and in two different space groups is reported. Crystals from the first condition diffracted to 1.1 A 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 A and belong to a primitive monoclinic space group. Determination of the detailed atomic structure of alpha-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. PMID:17077490

Pathuri, Puja; Nguyen, Emily Tam; Luecke, Hartmut

2006-11-01

232

The profile of snoRNA-derived microRNAs that regulate expression of variant surface proteins in Giardia lamblia.  

Science.gov (United States)

In the current investigation, we analysed all the known small nucleolar RNAs (snoRNAs) in the deeply branching protozoan parasite Giardia lamblia for potential microRNAs (miRNAs) that might be derived from them. Two putative miRNAs have since been identified by Northern blot, primer extension, 3' RACE and co-immunoprecipitation with Giardia Argonaute (GlAgo), and designated miR6 and miR10. Giardia Dicer (GlDcr) is capable of processing the snoRNAs into the corresponding miRNAs in vitro. Potential miR6 and miR10 binding sites in Giardia genome were predicted bio-informatically. A miR6 binding site was found at the 3' untranslated regions (UTR) of 44 variant surface protein (vsp) genes, whereas a miR10 binding site was identified at the 3' end of 159 vsp open-reading frames. Thirty-three of these vsp genes turned out to contain binding sites for both miR6 and miR10. A reporter mRNA tagged with the 3' end of vsp1267, which contains the target sites for both miRNAs, was translationally repressed by both miRNAs in Giardia. Episomal expression of an N-terminal c-myc tagged VSP1267 was found significantly repressed by introducing either miR6 or miR10 into the cells and the repressive effects were additive. When the 2'-O-methyl antisense oligos (ASOs) of either miR6 or miR10 was introduced, however, there was an enhancement of tagged VSP1267 expression suggesting an inhibition of the repressive effects of endogenous miR6 or miR10 by the ASOs. Of the total 220 vsp genes in Giardia, we have now found 178 of them carrying putative binding sites for all the miRNAs that have been currently identified, suggesting that miRNAs are likely the regulators of VSP expression in Giardia. PMID:22568619

Li, Wei; Saraiya, Ashesh A; Wang, Ching C

2012-09-01

233

??????: Giardia intestinalis  

Full Text Available Protozoa Giardiinae Giardia intestinalis Giardia duodenalis (synonym) NCBI 5741 Giardia intestin alis (scientific name) NCBI 5741 Giardia lamblia (genbank synonym) NCBI 5741

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Isolation of two Giardia lamblia (WB strain) clones with distinct surface protein and antigenic profiles and differing infectivity and virulence.  

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To determine the relationship between antigenic profiles and pathogenicity among Giardia lamblia clones (WB strain), trophozoites were cloned by the technique of limiting dilution. The phenotype of each clone was determined by an indirect immunofluorescence test using a polyclonal rabbit anti-G. lamblia trophozoite serum made against the parent strain. Two clones were chosen for further studies: a highly fluorescent clone, F+, in which more than 95% of the trophozoites fluoresced, and a low-f...

Udezulu, I. A.; Visvesvara, G. S.; Moss, D. M.; Leitch, G. J.

1992-01-01

235

Avaliação de diferentes métodos no diagnóstico laboratorial de Giardia lamblia  

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Full Text Available

Giardia lamblia é um enteroparasita de prevalência significativa no mundo inteiro. Estudou-se a reprodutibilidade diagnóstica laboratorial por meio dos métodos Coprotest®, Direto modificado, Faust e Hematoxilina Férrica, para o protozoário G. lamblia, segundo a associação com algumas características da população de estudo tais como grupo etário, gênero e distribuição dos casos segundo a variação sazonal nos meses em que se desenvolveu a pesquisa. Fezes de 200 crianças da região de Araraquara-SP, foram examinadas pelos quatro métodos, e os resultados comparados. Verificou-se que 8% delas, encontravam-se parasitadas por G. lamblia. Não houve associação com o gênero; quanto à idade ocorreram mais casos no grupo de três a cinco anos e a maior freqüência de casos foi no mês de janeiro. Em relação ao diagnóstico laboratorial concluiu-se que os resultados mais confiáveis podem ser obtidos quando se utiliza duas metodologias associadas de ótima reprodutibilidade que neste estudo foram Coprotest - Faust; Direto-Faust e Coprotest-Direto (k > 0,81. Palavras-chave: G. lamblia; métodos diagnósticos; Coprotest®; Direto modificado; Faust; Hematoxilina Férrica.

J. G.D. GARCIA

2009-01-01

236

A unique mechanism of nuclear division in Giardia lamblia involves components of the ventral disk and the nuclear envelope  

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Full Text Available The fine structure of the binucleate, parasitic protist Giardia lamblia during interphase and divisional stages was studied by serial thin sectioning and three-dimensional reconstructions. The earlier sign of nuclear division is the development of a few peripheral areas of densely packed chromatin directly attached to the inner nuclear envelope. An intracytoplasmic sheet of ventral disk components grows from the cell periphery towards one of the nuclei, apparently constricting this nucleus, which becomes located at a ventral bulge. After the basal bodies become duplicated, a full nuclear division occurs in trophozoites, giving two pairs of parent-daughter nuclei. This full division occurs in a dorsal-ventral direction, with the resulting nuclear pairs located at the sides of the two sets of basal bodies. A new ventral disk is formed from the disk-derived sheets in the cell harboring the four nuclei. Cytokinesis is polymorphic, but at early stages is dorsal-to-dorsal. Encysting trophozoites show the development of Golgi cisternae stacks and dense, specific secretory granules. 3-D reconstructions show that cysts contain a single pair of incompletely strangled nuclei. The dividing Giardia lacks a typical, microtubular spindle either inside or outside the nuclei. The nuclear envelope seems to be the only structure involved in the final division of the parent-daughter nuclei.

Alberto J. Solari

2003-12-01

237

A unique mechanism of nuclear division in Giardia lamblia involves components of the ventral disk and the nuclear envelope  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english The fine structure of the binucleate, parasitic protist Giardia lamblia during interphase and divisional stages was studied by serial thin sectioning and three-dimensional reconstructions. The earlier sign of nuclear division is the development of a few peripheral areas of densely packed chromatin d [...] irectly attached to the inner nuclear envelope. An intracytoplasmic sheet of ventral disk components grows from the cell periphery towards one of the nuclei, apparently constricting this nucleus, which becomes located at a ventral bulge. After the basal bodies become duplicated, a full nuclear division occurs in trophozoites, giving two pairs of parent-daughter nuclei. This full division occurs in a dorsal-ventral direction, with the resulting nuclear pairs located at the sides of the two sets of basal bodies. A new ventral disk is formed from the disk-derived sheets in the cell harboring the four nuclei. Cytokinesis is polymorphic, but at early stages is dorsal-to-dorsal. Encysting trophozoites show the development of Golgi cisternae stacks and dense, specific secretory granules. 3-D reconstructions show that cysts contain a single pair of incompletely strangled nuclei. The dividing Giardia lacks a typical, microtubular spindle either inside or outside the nuclei. The nuclear envelope seems to be the only structure involved in the final division of the parent-daughter nuclei.

Solari, Alberto J.; Rahn, Monica I.; Saura, Alicia; Lujan, Hugo D..

238

Nucleotide sequence of a second alpha giardin gene and molecular analysis of the alpha giardin genes and transcripts in Giardia lamblia.  

Science.gov (United States)

The giardins are a group of proteins with relative molecular masses (Mrs) between 29,000 and 38,000 that are specific to the ventral disk of the intestinal protozoan parasite Giardia lamblia. We previously have characterized alpha-giardin, renamed here alpha-1-giardin, as a novel 33-kDa protein located on the edges of the disk microribbons. Southern blot analysis of G. lamblia genomic DNA, followed by cloning and sequencing, revealed the existence of a related gene that we have called alpha-2-giardin. Sequence comparison of the alpha-giardin genes reveals 81% identity at the nucleotide level and 77% at the predicted amino acid level. The predicted alpha-giardins have similar Mrs of approximately 33,900 and are very rich in alpha-helix conformations. Each gene is present in single copy and, like many other known Giardia coding sequences, exhibits a strong preference for cytidine and guanosine in the third base position of each codon. Chromosome hybridization analysis indicates that both genes are either on the same chromosome or on chromosomes with similar mobility. Experiments utilizing primer extension and RNA sequencing provide evidence that both genes are transcribed. The stable transcripts have extremely short leader regions of only 3 nucleotides, and the downstream sequence of the alpha-2-giardin gene reveals that the sequence AGTPuAA remains a consistent element within G. lamblia protein-encoding genes. PMID:1542319

Alonso, R A; Peattie, D A

1992-01-01

239

The risk of infection from Giardia lamblia due to drinking water supply, use of water, and latrines among preschool children in rural Lesotho.  

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Stool samples were collected from 267 rural, preschool children in four districts in Lesotho during October-November, 1984. Sixty-three children (23.6%) were tested positive for Giardia lamblia, the most commonly recovered parasite from stool samples. The use of low amounts of water for personal hygiene was associated significantly with having G. lamblia (OR = 2.42), but the use of traditional, non-improved drinking water sources (OR = 1.38) or lack of latrines (OR = 0.94) was not. Although G. lamblia may be primarily waterborne in developed countries, the amount of water that is used for personal and domestic hygiene may be more important than the quality of drinking water in developing countries. Other risk factors that were identified to be associated significantly with having or not having Giardia were child older than 24 months (OR = 6.79), mother less than 20 years of age (OR = 5.18), residing in Mohales Hoek district (OR = 2.33), and possessing several agricultural tools (OR = 0.70). PMID:2722373

Esrey, S A; Collett, J; Miliotis, M D; Koornhof, H J; Makhale, P

1989-03-01

240

Comparación de métodos de lisis y extracción de ADN de trofozoítos de Giardia lamblia / COMPARISON OF LYSIS METHODS AND DNA EXTRACTION OF GIARDIA LAMBLIA TROPHOZOITES  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Se evaluó la eficiencia de procedimientos de lisis y tratamientos de extracción de ADN de trofozoítos de Giardia lamblia respecto a la eficiencia de ruptura, cantidad y pureza de ADN, además de los tiempos de procesamiento y costos. Se testearon cinco métodos de lisis (agua destilada y calor; agua d [...] estilada, calor y proteinasa K; buffer de lisis D; buffer de lisis E y un kit comercial) y tres métodos de purificación de ADN (fenol:cloroformo: isoamílico; Chelex 100 y un kit comercial). Los datos obtenidos se analizaron estadísticamente. La combinación de buffer de lisis E y Chelex fue un método simple y económico, que produjo alto rendimiento de ADN con baja pureza. Ella técnica comercial fue un método simple, más costoso que produjo bajas cantidades de ADN con un nivel de pureza apropiado para estudios moleculares Abstract in english The efficiency of lysis procedures and DNA purification treatments of Giardia lamblia trophozoites were evaluated regarding the breaking-up efficiency, quantity and pureness of DNA, processing time and costs. Five lysis methods (distilled water and heating; distilled water, heating and proteinase K; [...] buffer D Lysis; buffer E lysis, and commercial kit), and three DNA purification methods (phenol:chloroform:isoamilic, Chelex 100 and commercial kit) were tested. The obtained data were statistically analyzed. The buffer E lysis and Chelex combination was simple and economic method which produced high DNA performance with low pureness. Commercial kit was simple and expensive method which generated low yields of DNA with appropriate purity level for molecular analysis

MOLINA, NORA B; POLVERINO, DANIELA; MINVIELLE, MARTA C; APEZTEGUÍA, MARÍA; AGUILAR, MARIO; BASUALDO, JUAN A.

 
 
 
 
241

Characterization of Microtubule-Binding and Dimerization Activity of Giardia lamblia End-Binding 1 Protein  

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End-binding 1 (EB1) proteins are evolutionarily conserved components of microtubule (MT) plus-end tracking protein that regulate MT dynamics. Giardia lamblia, with two nuclei and cytoskeletal structures, requires accurate MT distribution for division. In this study, we show that a single EB1 homolog gene of G. lamblia regulates MT dynamics in mitosis. The haemagglutinin-tagged G. lamblia EB1 (GlEB1) localizes to the nuclear envelopes and median bodies, and is transiently present in mitotic spindles of dividing cells. Knockdown of GlEB1 expression using the morpholinos-based anti-EB1 oligonucleotides, resulted in a significant defect in mitosis of Giardia trophozoites. The MT-binding assays using recombinant GlEB1 (rGlEB1) proteins demonstrated that rGlEB1102–238, but not rGlEB11–184, maintains an MT-binding ability comparable with that of the full length protein, rGlEB11–238. Size exclusion chromatography showed that rGlEB1 is present as a dimer formed by its C-terminal domain and a disulfide bond. In vitro-mutagenesis of GlEB1 indicated that an intermolecular disulfide bond is made between cysteine #13 of the two monomers. Complementation assay using the BIM1 knockout mutant yeast, the yeast homolog of mammalian EB1, indicated that expression of the C13S mutant GlEB1 protein cannot rescue the mitotic defect of the BIM1 mutant yeast. These results suggest that dimerization of GlEB1 via the 13th cysteine residues plays a role during mitosis in Giardia.

Kim, Juri; Nagami, Sara; Lee, Kyu-Ho; Park, Soon-Jung

2014-01-01

242

Characterization of microtubule-binding and dimerization activity of Giardia lamblia end-binding 1 protein.  

Science.gov (United States)

End-binding 1 (EB1) proteins are evolutionarily conserved components of microtubule (MT) plus-end tracking protein that regulate MT dynamics. Giardia lamblia, with two nuclei and cytoskeletal structures, requires accurate MT distribution for division. In this study, we show that a single EB1 homolog gene of G. lamblia regulates MT dynamics in mitosis. The haemagglutinin-tagged G. lamblia EB1 (GlEB1) localizes to the nuclear envelopes and median bodies, and is transiently present in mitotic spindles of dividing cells. Knockdown of GlEB1 expression using the morpholinos-based anti-EB1 oligonucleotides, resulted in a significant defect in mitosis of Giardia trophozoites. The MT-binding assays using recombinant GlEB1 (rGlEB1) proteins demonstrated that rGlEB1102-238, but not rGlEB11-184, maintains an MT-binding ability comparable with that of the full length protein, rGlEB11-238. Size exclusion chromatography showed that rGlEB1 is present as a dimer formed by its C-terminal domain and a disulfide bond. In vitro-mutagenesis of GlEB1 indicated that an intermolecular disulfide bond is made between cysteine #13 of the two monomers. Complementation assay using the BIM1 knockout mutant yeast, the yeast homolog of mammalian EB1, indicated that expression of the C13S mutant GlEB1 protein cannot rescue the mitotic defect of the BIM1 mutant yeast. These results suggest that dimerization of GlEB1 via the 13th cysteine residues plays a role during mitosis in Giardia. PMID:24828878

Kim, Juri; Nagami, Sara; Lee, Kyu-Ho; Park, Soon-Jung

2014-01-01

243

The application of on-chip optofluidic microscopy for imaging Giardia lamblia trophozoites and cysts  

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The optofluidic microscope (OFM) is a lensless, low-cost and highly compact on-chip device that can enable high-resolution microscopy imaging. The OFM performs imaging by flowing/scanning the target objects across a slanted hole array; by measuring the time-varying light transmission changes through the holes, we can then render images of the target objects at a resolution that is comparable to the holes' size. This paper reports the adaptation of the OFM for imaging Giardia lamblia trophozoi...

Lee, Lap Man; Cui, Xiquan; Yang, Changhuei

2009-01-01

244

Killing of Giardia lamblia by human milk is mediated by unsaturated fatty acids.  

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Giardia lamblia trophozoites were killed in vitro by 1% fresh human milk in the presence of bile. A similar effect was achieved in the absence of bile with milk which had been stored for at least 24 h at 6 degrees C. This killing activity was found to be caused by unsaturated fatty acids. Depending on their chain length and the number of double bonds, the concentrations of unsaturated fatty acids required for a 50% killing effect varied between 15 and 36 microM. The saturated palmitic and ste...

Rohrer, L.; Winterhalter, K. H.; Eckert, J.; Ko?hler, P.

1986-01-01

245

Lipidomic Analysis Reveals That Phosphatidylglycerol and Phosphatidylethanolamine are Newly Generated Phospholipids in an Early-Divergent Protozoan, Giardia lamblia  

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The pathogenic protozoan Giardia lamblia is known to not synthesize membrane lipids de novo. Therefore, it is possible that lipids in the small intestine, where trophozoites colonize, play key roles in regulating the growth and differentiation of this important pathogen. The focus of the current study is to conduct a complete lipidomic analysis and to test the hypothesis that Giardia has some ability to generate new phospholipids (PLs). Using mass spectrometry, now we show that phosphatidylgl...

Yichoy, Mayte; Nakayasu, Ernesto S.; Shpak, Max; Aguilar, Clemente; Aley, Stephen B.; Almeida, Igor C.; Das, Siddhartha

2009-01-01

246

In vitro susceptibilities of 25 Giardia lamblia isolates of human origin to six commonly used antiprotozoal agents.  

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The role drug resistance plays in the occurrence of chronic and recurrent giardiasis has not been established. Extensive data on the susceptibility to antimicrobial agents of living Giardia spp. trophozoites from human origin are lacking. We have determined with a macrodilution method in semisolid medium the in vitro susceptibility of 25 Giardia lamblia isolates, all obtained by routine cultivation of the duodenal fluid of children to six commonly used antiprotozoal drugs. The results showed ...

Gordts, B.; Hemelhof, W.; Asselman, C.; Butzler, J. P.

1985-01-01

247

Sorting of encystation-specific cysteine protease to lysosome-like peripheral vacuoles in Giardia lamblia requires a conserved tyrosine-based motif.  

Science.gov (United States)

Encystation-specific cysteine protease (ESCP) was the first membrane-associated protein described to be part of the lysosome-like peripheral vacuoles in the intestinal parasite Giardia lamblia. ESCP is homologous to cathepsin C enzymes of higher eukaryotes, but is distinguished from other lysosomal cysteine proteases because it possesses a transmembrane domain and a short cytoplasmic tail. Tyrosine-based motifs within tails of membrane proteins are known to participate in endosomal/lysosomal protein sorting in higher eukaryotes. In this study, we show that a YRPI motif within the ESCP cytoplasmic tail is necessary and sufficient to mediate ESCP sorting to peripheral vacuoles in Giardia. Deletion and point mutation analysis demonstrated that the tyrosine residue is critical for ESCP sorting, whereas amino acids located at the Y+1 (Arg), Y+2 (Pro), and Y+3 (Ile) positions show minimal effect. Loss of the motif resulted in surface localization, whereas addition of the motif to a variant-specific surface protein resulted in lysosomal localization. Although Giardia trophozoites lack a morphologically discernible Golgi apparatus, our findings indicate that this parasite directs proteins to the lysosomes using a conserved sorting signal similar to that used by yeast and mammalian cells. Because Giardia is one of the earliest branching protist, these results demonstrate that sorting motifs for specific protein traffic developed very early during eukaryotic evolution. PMID:12466276

Touz, Maria C; Lujan, Hugo D; Hayes, Stanley F; Nash, Theodore E

2003-02-21

248

Identification in the Ancient Protist Giardia lamblia of Two Eukaryotic Translation Initiation Factor 4E Homologues with Distinctive Functions†  

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Eukaryotic translation initiation factor 4E (eIF4E) binds to the m7GTP of capped mRNAs and is an essential component of the translational machinery that recruits the 40S small ribosomal subunit. We describe here the identification and characterization of two eIF4E homologues in an ancient protist, Giardia lamblia. Using m7GTP-Sepharose affinity column chromatography, a specific binding protein was isolated and identified as Giardia eIF4E2. The other homologue, Giardia eIF4E1, bound only to th...

2005-01-01

249

The structure of tryptophanyl-tRNA synthetase from Giardia lamblia reveals divergence from eukaryotic homologs.  

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The 2.1A crystal structure of tryptophanyl-tRNA synthetase (TrpRS) from the diplomonad Giardia lamblia reveals that the N-terminus of this class I aminoacyl-tRNA synthetase forms a 16-residue alpha-helix. This helix replaces a beta-hairpin that is required by human TrpRS for normal activity and has been inferred to play a similar role in all eukaryotic TrpRS. The primary sequences of TrpRS homologs from several basal eukaryotes including Giardia lack a set of three residues observed to stabilize interactions with this beta-hairpin in the human TrpRS. Thus the present structure suggests that the activation reaction mechanism of TrpRS from the basal eukaryote G. lamblia differs from that of higher eukaryotes. Furthermore, the protein as observed in the crystal forms an (alpha(2))(2) homotetramer. The canonical dimer interface observed in all previous structures of tryptophanyl-tRNA synthetases is maintained, but in addition each N-terminal alpha-helix reciprocally interlocks with the equivalent helix from a second dimer to form a dimer of dimers. Although we have no evidence for tetramer formation in vivo, modeling indicates that the crystallographically observed tetrameric structure would be compatible with the tRNA binding mode used by dimeric TrpRS and TyrRS. PMID:20438846

Arakaki, Tracy L; Carter, Megan; Napuli, Alberto J; Verlinde, Christophe L M J; Fan, Erkang; Zucker, Frank; Buckner, Frederick S; Van Voorhis, Wesley C; Hol, Wim G J; Merritt, Ethan A

2010-08-01

250

Molecular Characterization of the Iranian Isolates of Giardia Lamblia: Application of the Glutamate Dehydrogenase Gene  

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Full Text Available Background: This study was conducted to determine of molecular epidemiology of the Giardia lamblia by PCR-RFLP method in Tehran, capital of Iran. Methods: Thirty eight stool samples were randomly selected from 125 patients diagnosed with giardiasis using microscopy in Tehran. DNA extraction of some samples were performed by phenol/chloroform/isoamyl alcohol method and to raise the sensitivity of the PCR assay, the genomic DNA of the others were extracted using glass beads and the QIAamp Stool Mini Kit in order to effectively remove the PCR inhibitors. A single step PCR-RFLP assay, targeting the glutamate dehydrogenase (gdh locus, was used to differentiate within and between assemblages A and B that have been found in humans. Results: Of the 38 isolates, 33 samples (87% were found as G. lamblia (genotype AII, 3 (7.8% belonged to assemblage B, genotype BIII, the mixed of genotype AII and B were detected only in two samples (5.2%. Conclusions: PCR-RFLP is a sensitive and powerful analytical tool that allows effective genotype discrimination within and between assemblages at targeting gdh gene, and makes it possible to identify the presence of mixed genotypes. Our data suggest that there is an anthroponotic origin of the infection route, assemblage A group II, in Tehran so it seems that the main reservoir of Giardia infection is humans in the area studies.

L Akhlaghi

2008-07-01

251

Comparação de quatro métodos laboratoriais para diagnóstico da Giardia lamblia em fezes de crianças residentes em Belém, Pará  

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Full Text Available Relatamos a comparação de quatro metodologias para o diagnóstico da Giardia lamblia em material fecal de crianças, Belém/PA. A Hematoxilina Férrica e o método direto apresentaram menor positividade, enquanto que o Método de Faust continua uma boa escolha para o diagnóstico e o Ensaio imunoenzimático melhora a qualidade da detecção deste parasito.

Machado Ricardo Luiz Dantas

2001-01-01

252

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

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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.

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

1993-01-01

253

The effects of dihydroartemisinin on Giardia lamblia morphology and cell cycle in vitro.  

Science.gov (United States)

Several anti-Giardia drugs, such as metronidazole, tinidazole, mebendazole, albendazole and furazolidone, are usually effective but have severe side effects and potential toxicity. An urgent need exists for more effective and less toxic agents that can act against this protozoan. For this purpose, the effects of dihydroartemisinin (DHA) on Giardia lamblia were investigated in vitro. Axenically grown G. lamblia trophozoites were treated with DHA (LD(50) = 200 microg/mL) at different time intervals. The morphological and ultrastructural changes of the treated trophozoites were observed by both light and transmission electron microscopy (TEM). Changes in the cell cycle of the treated cells were observed by flow cytometry. By light microscopy, we observed that DHA-treated trophozoites were detached from the wall of the culture tube and shown bradypraxia and bubbles in the dorsal and ventral surfaces. Ultrastructural observations by TEM revealed that DHA promoted modifications of the cell shape, pronounced dorsal vesiculation, plasma membrane blebbing, disaggregation of ribosomes, depletion of cytoplasmic matrix and heavy deposition of electron-dense precipitates on the cytoplasm and nucleus. The main changes observed in the treated group included the following: (1) trophozoites were rounder in shape and the endoplasmic reticulum was dilated, (2) enlarged trophozoites contained lamella structures and deformed nuclei, (3) trophozoites displayed dissolved cytoplasm with large vacuole spaces or decreased cytoplasmic volume, (4) adhesive disc bubbles or the lamella structures of cytoplasm were clearly observed, and (5) cell division was arrested. Using microscopy and cytometry techniques, we demonstrate that changes in G. lamblia morphology and cell cycle state were induced by DHA. PMID:20422219

Tian, Xi Feng; Shen, Hai E; Li, Ji; Chen, Yang; Yang, Zhi Hong; Lu, Si Qi

2010-07-01

254

Commercial assay for detection of Giardia lamblia and Cryptosporidium parvum antigens in human fecal specimens by rapid solid-phase qualitative immunochromatography.  

Science.gov (United States)

The ImmunoCard STAT! Cryptosporidium/Giardia rapid assay (Meridian Bioscience, Inc.) is a solid-phase qualitative immunochromatographic assay that detects and distinguishes between Giardia lamblia and Cryptosporidium parvum in aqueous extracts of human fecal specimens (fresh, frozen, unfixed, or fixed in 5 or 10% formalin or sodium acetate-acetic acid-formalin). By using specific antibodies, antigens specific for these organisms are isolated and immobilized on a substrate. After the addition of appropriate reagents, a positive test is detected visually by the presence of a gray-black color bar (regardless of the intensity) next to the organism name printed on the test device. A control is included in the device. Steps include tube preparation (buffer, patient specimen, conjugates A and B), testing (addition of sample onto the test device), and visual reading (total time, 12 min). Test performance was evaluated with known positive and negative stool specimens (170 specimens positive for Giardia and 231 specimens negative for Giardia) (85 specimens positive for Cryptosporidium and 316 specimens negative for Cryptosporidium); they were tested with trichrome, iron-hematoxylin, or modified acid-fast stains or the Meridian Bioscience, Inc., Giardia/Cryptosporidium Merifluor combination reagent; specimens with discrepant results were retested by using the Merifluor combination reagent. On the basis of the results of the reference methods, the sensitivities, specificities, and positive and negative predictive values were as follows: for G. lamblia, 93.5, 100, 100, and 95.5%, respectively; for C. parvum, 98.8, 100, 100, and 99.7%, respectively. False-negative results for G. lamblia were obtained with specimens with low parasite numbers (n = 7) or specimens containing trophozoites only (n = 3); one specimen with a false-negative result contained numerous cysts. The one specimen false negative for C. parvum was confirmed to be positive by immunofluorescence. No cross-reactivity was seen with 10 different protozoa (152 challenges), nine different helminths (35 challenges), or human cells (4 challenges) found in fecal specimens. This rapid test system may be very beneficial in the absence of trained microscopists; however, for patients who remain symptomatic after a negative result, the ova and parasite examination and special stains for other coccidia and the microsporidia should always remain options. PMID:12517850

Garcia, Lynne S; Shimizu, Robyn Y; Novak, Susan; Carroll, Marilyn; Chan, Frank

2003-01-01

255

Does breast-feeding protect the child from Giardia lamblia infection?  

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Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Background: Giardia lamblia is one of the most prevalent protozoa infections of the human small intestine. Although anyone can be infected by Giardia, women and children are more susceptible. Giardia infection can cause malnutrition, diarrhea and indigestion of fat. In this study, the effect of breast-feeding on the prevalence of Giardia among children is investigated. "nMethods: A total of 482 children, aged 6 to 24 months, from the urban areas of Semnan, Damghan and Garmsar in Iran, were enrolled in this survey. Each mother underwent an interview and filled out a questionnaire that included mother's age, family size, birth order of the child, age and sex of the child and type of milk consumed, among other variables. Then, each mother was given a sample container with 30cc of phenol alcohol formaldehyde (PAF and an applicator for sampling her child's stool. Each mother was trained to consecutively sample her child's stool for three days, to put the stool into the provided container using the applicator and to shake it until the sample and liquid appeared homogenous. The sample was examined using the direct method, using formalin-ether and thionine. Data was analyzed using the c2 test and logistic regression using SPSS version 11.5."n"nResults: The mean age of the children was 13.6(±5.6 months. Of these children, 45.6% were girls. The prevalence of G. lamblia infection was 8.5%. There was a significant relationship between Giardia and the age of the child, education level of the mother and type of milk the child consumed (p<0.05, such that children who had not consumed their mothers' milk were more likely to be infected compared to those who had been breast fed (OR=2.38, 95% CI: 1.13-5.03, P=0.023."n"nConclusions: Results show that breast-feeding is a safer method of feeding with regard to Giardia infection. Therefore, mothers should be educated to breast-feed their children and not use other types of milk or milk substitutes. This important issue must be considered by policy makers for education and subsidy programs. "n"n Keywords: Giardia lamblia, breast-feeding, formula milk, cow's milk.

Ghorbani R

2008-09-01

256

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

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?-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.

Pathuri, Puja; Nguyen, Emily Tam; Luecke, Hartmut

2006-01-01

257

Identification of Variant-Specific Surface Proteins in Giardia muris Trophozoites  

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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.

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

2005-01-01

258

Comparison of Two Target Genes for Detection and Genotyping of Giardia lamblia in Human Feces by PCR and PCR-Restriction Fragment Length Polymorphism  

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A PCR assay targeting the tpi gene was developed to detect and to genotype Giardia lamblia in human feces. Our assay was specific and discriminated between G. lamblia assemblages A and B. G. lamblia cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of tpi or gdh genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assem...

2005-01-01

259

Characteristics and risk factors for symptomatic Giardia lamblia infections in Germany  

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Full Text Available Abstract Background In developed countries, giardiasis is considered a travel related disease. However, routine surveillance data from Germany indicate that >50% of infections were acquired indigenously. We studied the epidemiological characteristics of symptomatic Giardia infections acquired in Germany and abroad, and verified the proportion of cases acquired in Germany in order to investigate risk factors for sporadic autochthonous Giardia infections. Methods We identified Giardia cases notified by 41 local health authorities between February 2007 and January 2008 and interviewed them on their clinical symptoms, underlying morbidities, travel abroad and potential risk factors for the disease. We conducted a case-control-study including laboratory-confirmed (microscopy or antigen-test autochthonous Giardia cases with clinical manifestations (diarrhoea, cramps, bloating and randomly selected controls from the local population registry matched by county of residence and age-group (0-5, 6-19, ?20 years. Secondary cases, controls with diarrhoea and persons who had travelled outside Germany in the three weeks prior to disease onset (exposure period were excluded. We calculated adjusted odds ratios (aOR with 95% confidence intervals (CI using conditional logistic regression. Results Of 273 interviewed cases, 131 (48% had not travelled abroad during the defined exposure period. Of these 131, 85 (65% were male, 68 (54% were living in communities with >100,000 inhabitants and 107 (83% were aged 20 years or older. We included 120 cases and 240 controls in the case-control study. Cases were more likely to be male (aOR 2.5 CI 1.4-4.4, immunocompromised (aOR 15.3 CI 1.8-127 and daily consumers of green salad (aOR 2.9 CI 1.2-7.2. Contact with animals (pets/farm animals and exposure to surface water (swimming/water sports were not associated with symptomatic disease. Conclusions A substantial proportion of Giardia lamblia cases in Germany are indigenously acquired. Symptomatic cases are significantly more likely to be immunocompromised than control persons from the general population. Physicians should consider Giardia infections among patients with no recent history of travel abroad, particularly if they have immune deficiencies. Green salads may be an important vehicle of infection. Information campaigns highlighting this food-borne risk should emphasise the risk to persons with immune deficiencies.

Stark Klaus

2010-01-01

260

The transcriptional response to encystation stimuli in Giardia lamblia is restricted to a small set of genes.  

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The protozoan parasite Giardia lamblia undergoes stage differentiation in the small intestine of the host to an environmentally resistant and infectious cyst. Encystation involves the secretion of an extracellular matrix comprised of cyst wall proteins (CWPs) and a ?(1-3)-GalNAc homopolymer. Upon the induction of encystation, genes coding for CWPs are switched on, and mRNAs coding for a Myb transcription factor and enzymes involved in cyst wall glycan synthesis are upregulated. Encystation in vitro is triggered by several protocols, which call for changes in bile concentrations or availability of lipids, and elevated pH. However, the conditions for induction are not standardized and we predicted significant protocol-specific side effects. This makes reliable identification of encystation factors difficult. Here, we exploited the possibility of inducing encystation with two different protocols, which we show to be equally effective, for a comparative mRNA profile analysis. The standard encystation protocol induced a bipartite transcriptional response with surprisingly minor involvement of stress genes. A comparative analysis revealed a core set of only 18 encystation genes and showed that a majority of genes was indeed upregulated as a side effect of inducing conditions. We also established a Myb binding sequence as a signature motif in encystation promoters, suggesting coordinated regulation of these factors. PMID:20693303

Morf, Laura; Spycher, Cornelia; Rehrauer, Hubert; Fournier, Catharine Aquino; Morrison, Hilary G; Hehl, Adrian B

2010-10-01

 
 
 
 
261

A mitochondrial-like chaperonin 60 gene in Giardia lamblia: evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria.  

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Diplomonads, parabasalids, as represented by trichomonads, and microsporidia are three protist lineages lacking mitochondria that branch earlier than all other eukaryotes in small subunit rRNA and elongation factor phylogenies. The absence of mitochondria and plastids in these organisms suggested that they diverged before the origin of these organelles. However, recent discoveries of mitochondrial-like heat shock protein 70 and/or chaperonin 60 (cpn60) genes in trichomonads and microsporidia imply that the ancestors of these two groups once harbored mitochondria or their endosymbiotic progenitors. In this report, we describe a mitochondrial-like cpn60 homolog from the diplomonad parasite Giardia lamblia. Northern and Western blots reveal that the expression of cpn60 is independent of cellular stress and, except during excystation, occurs throughout the G. lamblia life cycle. Phylogenetic analyses position the G. lamblia cpn60 in a clade that includes mitochondrial and hydrogenosomal cpn60 proteins. The most parsimonious interpretation of these data is that the cpn60 gene was transferred from the endosymbiotic ancestors of mitochondria to the nucleus early in eukaryotic evolution, before the divergence of the diplomonads and trichomonads from other extant eukaryotic lineages. A more complicated explanation requires that these genes originated from distinct alpha-proteobacterial endosymbioses that formed transiently within these protist lineages. PMID:9419358

Roger, A J; Svärd, S G; Tovar, J; Clark, C G; Smith, M W; Gillin, F D; Sogin, M L

1998-01-01

262

Impact of Helicobacter pylori and Giardia lamblia infections on chronic urticaria.  

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The etiology of chronic urticaria is largely unknown. The role of Helicobacter pylori infection, which is the most important cause of gastritis and peptic ulcer, is not clear in the pathophysiology of chronic urticaria. In this study, we aimed to define the impact of H. pylori on chronic urticaria. Thirty-eight patients who had chronic urticaria of unknown origin and dyspepsia were included in the study. In all patients, standard laboratory tests for detection of urticaria etiology were performed. Mean urticaria symptom scores of patients were carried out. All patients underwent upper gastrointestinal endoscopy. The presence of H. pylori was investigated using urease testing and histopathology. Duodenal fluid aspirated during upper endoscopy was examined for the presence of Giardia lamblia. H. pylori infection was detected in 29 patients. After successful eradication of H. pylori infection, the mean symptom score of patients did not change significantly (2.6 +/- 0.6 vs., 2.4 +/- 0.8). Only one patient had a total disappearance of urticaria symptoms. Out of 38 patients, only one had G. lamblia infection. The results of our study suggest that there is no association between H. pylori infection and chronic urticaria. PMID:10879997

Erel, F; Sener, O; Erdil, A; Karaayvaz, M; Gür, G; Caliskaner, Z; Ozangüç, N

2000-01-01

263

Giardia lamblia EB1 is a functional homolog of yeast Bim1p that binds to microtubules.  

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Giardia lamblia, with two nuclei and a distinct polarized morphology, is an interesting organism for investigating how distribution of its microtubule (MT) is controlled during its cell cycle. In this study, we identified the end-binding protein 1 (EB1) of G. lamblia, a well-known microtubule-associated protein that organizes MTs in eukaryotes. Immunofluorescence assays using recombinant EB1 (rEB1)-specific antibodies demonstrated EB1 localization in nuclear membrane as well as in some cytoskeletal structures such as axomenes and median bodies of trophozoites of G. lamblia. Complementation experiments using the BIM1 knock-out mutant of yeast, the yeast homolog of mammalian EB1, showed that giardial EB1 was able to carry out a homologous function in controlling MT dynamics. In addition, rEB1 of G. lamblia co-precipitated with MTs by an in vitro binding assay, thereby demonstrating that G. lamblia EB1 is a MT-associated protein. These results, taken together, suggest that G. lamblia EB1 is a functional homolog of eukaryotic EB1 and is likely to be a determinant for MT distribution. PMID:18590831

Kim, Juri; Sim, Seobo; Kim, Junwon; Song, Kiwon; Yong, Tai-Soon; Park, Soon-Jung

2008-12-01

264

Freqüência de Giardia lamblia em cães atendidos em clínicas veterinárias de Porto Alegre, RS, Brasil / Frequency of Giardia lamblia in dogs attended by veterinary clinics in Porto Alegre city, RS, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A pesquisa de cistos de Giardia lamblia em fezes de cães oriundos de clínicas veterinárias de Porto Alegre, RS, Brasil, foi realizada pelo método de FAUST et al. (1939). Das 526 amostras analisadas, 38% (198) foram positivas para cistos de G. lamblia, sendo 22% (116) constituídos por animais menores [...] de 11 meses de idade e 16% (82) constituídos por animais com 12 meses ou mais de idade. Houve diferença significativa (p Abstract in english The method of Faust et al. (1939) was utilized for detection of Giardia lamblia cysts in feces from dogs in Porto Alegre city, Rio Grande Sul State, Brazil. From the 526 analyzed samples 38% (198) showed positive results for the presence of G. lamblia cyst, so 22% (116) belonged to group one, formed [...] by animals that were less than eleven months old; and 16% (82) belonged to group two, formed by animals that were twelve months or older. There was a significant difference (p

Adriane, Bartmann; Flávio Antônio Pacheco de, Araújo.

265

Freqüência de Giardia lamblia em cães atendidos em clínicas veterinárias de Porto Alegre, RS, Brasil Frequency of Giardia lamblia in dogs attended by veterinary clinics in Porto Alegre city, RS, Brazil  

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Full Text Available A pesquisa de cistos de Giardia lamblia em fezes de cães oriundos de clínicas veterinárias de Porto Alegre, RS, Brasil, foi realizada pelo método de FAUST et al. (1939. Das 526 amostras analisadas, 38% (198 foram positivas para cistos de G. lamblia, sendo 22% (116 constituídos por animais menores de 11 meses de idade e 16% (82 constituídos por animais com 12 meses ou mais de idade. Houve diferença significativa (pThe method of Faust et al. (1939 was utilized for detection of Giardia lamblia cysts in feces from dogs in Porto Alegre city, Rio Grande Sul State, Brazil. From the 526 analyzed samples 38% (198 showed positive results for the presence of G. lamblia cyst, so 22% (116 belonged to group one, formed by animals that were less than eleven months old; and 16% (82 belonged to group two, formed by animals that were twelve months or older. There was a significant difference (p<0,05 among the two groups checked by the c² test. From the animals researched, 54% (285 were male dogs and from these 20% (104 presented cysts in their feces. From the other 46% (241, which were female dogs, 18% (95 presented positive results for the cysts of G. lamblia in their sample. The c² test applied to these data showed that there was not any significant difference between the results found in female or male dogs of all ages. Based on these results, we can come to the conclusion that 38% of the analyzed dogs showed positive results for the infection of G. lamblia and that the younger animals those aged less than eleven months presented a rate of risk to get infected which is two times bigger than the ones for the animals with 12 months or older, as well as, the fact that the sex of the animals did not present any association to the positive results of infection.

Adriane Bartmann

2004-08-01

266

Comparison of Nine Commercially Available Enzyme-Linked Immunosorbent Assays for Detection of Giardia lamblia in Fecal Specimens  

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Overall performance, including ease of use, total hands-on time, incubation and processing times, sensitivity, and specificity, of each of nine enzyme-linked immunosorbent assays (ELISAs) were compared by using 222 individual fecal samples submitted for the detection of Giardia lamblia. The assays evaluated were manufactured by Alexon, Inc., Cambridge Biotech Corp., Meridian, Inc., and Trend Scientific, Inc. All assays used polyclonal antibodies except the “new and improved” Microplate (d...

Aldeen, William E.; Carroll, K.; Robison, A.; Morrison, M.; Hale, D.

1998-01-01

267

SUMOylation in Giardia lamblia: A Conserved Post-Translational Modification in One of the Earliest Divergent Eukaryotes  

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Post-translational modifications are able to regulate protein function and cellular processes in a rapid and reversible way. SUMOylation, the post-translational modification of proteins by the addition of SUMO, is a highly conserved process that seems to be present in modern cells. However, the mechanism of protein SUMOylation in earlier divergent eukaryotes, such as Giardia lamblia, is only starting to become apparent. In this work, we report the presence of a single SUMO gene encoding to SU...

Vranych, Cecilia V.; Merino, Mari?a C.; Nahuel Zamponi; Touz, Mari?a C.; Ro?polo, Andrea S.

2012-01-01

268

New Method Using Sedimentation and Immunomagnetic Separation for Isolation and Enumeration of Cryptosporidium parvum Oocysts and Giardia lamblia cysts  

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A new method for the isolation of Cryptosporidium parvum oocysts and Giardia lamblia cysts from biosolid samples has been developed that utilizes sedimentation and immunomagnetic separation. The method was used to recover stained cysts and oocysts (spike organisms) from primary settled sewage sludge, anaerobically digested sewage sludge, and bovine manure. Recovery efficiencies associated with this method were approximately 40 to 60% and were significantly greater than those associated with s...

Massanet-nicolau, Jaime

2003-01-01

269

Comparison of primers and optimization of PCR conditions for detection of Cryptosporidium parvum and Giardia lamblia in water.  

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Eight pairs of published PCR primers were evaluated for the specific detection of Cryptosporidium parvum and Giardia lamblia in water. Detection sensitivities ranged from 1 to 10 oocysts or cysts for purified preparations and 5 to 50 oocysts or cysts for seeded environmental water samples. Maximum sensitivity was achieved with two successive rounds of amplification and hybridization, with oligonucleotide probes detected by chemiluminescence. Primer annealing temperatures and MgCl2 concentrati...

Rochelle, P. A.; Leon, R.; Stewart, M. H.; Wolfe, R. L.

1997-01-01

270

Adhesion of Cryptosporidium parvum and Giardia lamblia to solid surfaces: the role of surface charge and hydrophobicity  

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Adhesion of Cryptosporidium parvum and Giardia lamblia to four materials of different surface charge and hydrophobicity was investigated. Glass beads were used with and without three polymer coatings: aminosilines (A0750), fluorosilines (T2494), an amino cationic polymer. Surface charge density and hydrophobicity of the beads were characterized by measuring the zeta potential (ZP) and the contact angle, respectively. Adhesion was derived from batch experiments where negatively charged (oo)cys...

Dai, X.; Boll, J.; Hayes, M. E.; Aston, D. E.

2004-01-01

271

Freqüencia da infecção por Giardia lamblia (Kunstler, 1882 em cães (Canis familiaris avaliada pelo Método de Faust e cols. (1939 e pela Coloração da Auramina, no município de Canoas, RS, Brasil Frequence of infection by Giardia lamblia (Kunstler, 1882 in dogs (Canis familiaris available trough the Faust and Collaborators Method (1939 and Auramine Staining in Canoas, RS, Brazil  

Directory of Open Access Journals (Sweden)

Full Text Available Giardia lamblia é um protozoário que acomete mais comumente animais jovens e que convivem em grupos. Apesar da alta prevalência, nem todos os animais apresentam a forma clínica da doença. Mesmo assim, a giardíase tem importância epidemiológica por possuir um elevado potencial zoonótico. O presente estudo teve como objetivo determinar a freqüência de Giardia lamblia em cães no município de Canoas, RS, Brasil, através do Método de Faust e cols. (1939 e da Técnica de Coloração da Auramina. Os grupos experimentais foram divididos de acordo com a procedência e o sexo. Das 332 amostras analisadas pelo Método de Faust e cols, a freqüência obtida foi de 34,04%, podendo variar de 28,95 a 39,13%, dentro de um intervalo de confiança de 95%. Destas amostras positivas, 40,96% foram de canil e 27,11% de cães de rua. O Teste Exato de Fisher aplicado a esses dados revelou existir uma diferença significativa (p=0,0107 entre as variáveis resultado e procedência. A variável sexo, neste método, não apresentou diferença significativa em relação ao resultado (P=0,8162 totalizando 33,11% de machos e 34,08% de fêmeas infectadas com o parasita. Das 147 amostras realizadas pela Técnica de Coloração da Auramina, 23 foram positivas, totalizando 15,65%. A análise estatística pelo Teste McNemar revelou existir diferença significativa entre as duas técnicas (P=0,0004. O valor Kappa foi igual a 0,07, considerado como um grau de concordância fraco. Os resultados encontrados neste estudo nos permitem afirmar que o Método de Faust e cols. foi o mais adequado para o diagnóstico da infecção por Giardia lamblia, sendo este parasita altamente prevalente na região estudada.Giardia lamblia is a protozoan that commonly infects young animals which live in groups. Despite its high prevalence many animals don’t exhibit clinical signs. Giardiasis is epidemiologically important concerning the zoonotic potential of the disease. The objective of this study was to determine the frequence of Giardia lamblia in the canine population of Canoas, RS, Brazil, applying the Faust and Collaborators Method (1939 and the Auramine Staining Technique. The dogs were classified according to the origin and gender. Feces samples of 332 dogs were analyzed by the Faust and Collaborators Method. The frequency of the infection obtained was 34.04%, ranging from 28.95% to 39.13% (confident interval at a 95% level. For kennel bred animals 40,96% of the samples were positive and for stray dogs 27.11%. Applying Fisher’s Exact Test to these figures there was a significant difference (P=0.0107 when comparing the origin of the animals and the results of the tests. However when comparing genders there was no significant difference (P=0.8162, the former with 33.11% of positive males and 34.08% positive females. When submitted to the Auramine Staining Technique(147 samples, 15.67% (23 of the samples resulted positive. The statistical analysis using the McNemar Test exposed a significant difference between both techniques (P=0.0004. The Kappa value of 0.07 obtained was considered of low rate. The results allow one to affirm that the Faust and Collaborators Method was the most suitable diagnostic test for Giardia lamblia infection, considering the high prevalence of this parasite in the studied region.

Cristiane Beck

2005-02-01

272

Freqüencia da infecção por Giardia lamblia (Kunstler, 1882) em cães (Canis familiaris) avaliada pelo Método de Faust e cols. (1939) e pela Coloração da Auramina, no município de Canoas, RS, Brasil / Frequence of infection by Giardia lamblia (Kunstler, 1882) in dogs (Canis familiaris) available trough the Faust and Collaborators Method (1939) and Auramine Staining in Canoas, RS, Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Giardia lamblia é um protozoário que acomete mais comumente animais jovens e que convivem em grupos. Apesar da alta prevalência, nem todos os animais apresentam a forma clínica da doença. Mesmo assim, a giardíase tem importância epidemiológica por possuir um elevado potencial zoonótico. O presente e [...] studo teve como objetivo determinar a freqüência de Giardia lamblia em cães no município de Canoas, RS, Brasil, através do Método de Faust e cols. (1939) e da Técnica de Coloração da Auramina. Os grupos experimentais foram divididos de acordo com a procedência e o sexo. Das 332 amostras analisadas pelo Método de Faust e cols, a freqüência obtida foi de 34,04%, podendo variar de 28,95 a 39,13%, dentro de um intervalo de confiança de 95%. Destas amostras positivas, 40,96% foram de canil e 27,11% de cães de rua. O Teste Exato de Fisher aplicado a esses dados revelou existir uma diferença significativa (p=0,0107) entre as variáveis resultado e procedência. A variável sexo, neste método, não apresentou diferença significativa em relação ao resultado (P=0,8162) totalizando 33,11% de machos e 34,08% de fêmeas infectadas com o parasita. Das 147 amostras realizadas pela Técnica de Coloração da Auramina, 23 foram positivas, totalizando 15,65%. A análise estatística pelo Teste McNemar revelou existir diferença significativa entre as duas técnicas (P=0,0004). O valor Kappa foi igual a 0,07, considerado como um grau de concordância fraco. Os resultados encontrados neste estudo nos permitem afirmar que o Método de Faust e cols. foi o mais adequado para o diagnóstico da infecção por Giardia lamblia, sendo este parasita altamente prevalente na região estudada. Abstract in english Giardia lamblia is a protozoan that commonly infects young animals which live in groups. Despite its high prevalence many animals don’t exhibit clinical signs. Giardiasis is epidemiologically important concerning the zoonotic potential of the disease. The objective of this study was to determine the [...] frequence of Giardia lamblia in the canine population of Canoas, RS, Brazil, applying the Faust and Collaborators Method (1939) and the Auramine Staining Technique. The dogs were classified according to the origin and gender. Feces samples of 332 dogs were analyzed by the Faust and Collaborators Method. The frequency of the infection obtained was 34.04%, ranging from 28.95% to 39.13% (confident interval at a 95% level). For kennel bred animals 40,96% of the samples were positive and for stray dogs 27.11%. Applying Fisher’s Exact Test to these figures there was a significant difference (P=0.0107) when comparing the origin of the animals and the results of the tests. However when comparing genders there was no significant difference (P=0.8162), the former with 33.11% of positive males and 34.08% positive females. When submitted to the Auramine Staining Technique(147 samples), 15.67% (23) of the samples resulted positive. The statistical analysis using the McNemar Test exposed a significant difference between both techniques (P=0.0004). The Kappa value of 0.07 obtained was considered of low rate. The results allow one to affirm that the Faust and Collaborators Method was the most suitable diagnostic test for Giardia lamblia infection, considering the high prevalence of this parasite in the studied region.

Cristiane, Beck; Flávio Antônio Pacheco de, Araújo; Adriana Tarnowski, Olicheski; Adriana Schneider, Breyer.

273

Non-specific reactions in enzyme linked immunosorbent assays for serum antibody to entamoeba histolytica and Giardia lamblia in non-endemic areas.  

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Serum samples from 20 Indian children with diarrhoea were compared with those from 20 children resident in the United Kingdom who had been diagnosed as having ulcerative colitis, or Crohn's disease, or indeterminate colitis using enzyme linked immunosorbent assays specific for Entamoeba histolytica and Giardia lamblia. More than 50% of the United Kingdom patients had high IgG responses in ELISAs for E histolytica and G lamblia. A confirmatory ELISA showed that the British sera reacted specifi...

1990-01-01

274

Identification in the Ancient Protist Giardia lamblia of Two Eukaryotic Translation Initiation Factor 4E Homologues with Distinctive Functions†  

Science.gov (United States)

Eukaryotic translation initiation factor 4E (eIF4E) binds to the m7GTP of capped mRNAs and is an essential component of the translational machinery that recruits the 40S small ribosomal subunit. We describe here the identification and characterization of two eIF4E homologues in an ancient protist, Giardia lamblia. Using m7GTP-Sepharose affinity column chromatography, a specific binding protein was isolated and identified as Giardia eIF4E2. The other homologue, Giardia eIF4E1, bound only to the m2,2,7GpppN structure. Although neither homologue can rescue the function of yeast eIF4E, a knockdown of eIF4E2 mRNA in Giardia by a virus-based antisense ribozyme decreased translation, which was shown to use m7GpppN-capped mRNA as a template. Thus, eIF4E2 is likely the cap-binding protein in a translation initiation complex. The same knockdown approach indicated that eIF4E1 is not required for translation in Giardia. Immunofluorescence assays showed wide distribution of both homologues in the cytoplasm. But eIF4E1 was also found concentrated and colocalized with the m2,2,7GpppN cap, 16S-like rRNA, and fibrillarin in the nucleolus-like structure in the nucleus. eIF4E1 depletion from Giardia did not affect mRNA splicing, but the protein was bound to Giardia small nuclear RNAs D and H known to have an m2,2,7GpppN cap, thus suggesting a novel function not yet observed among other eIF4Es in eukaryotes.

Li, Lei; Wang, Ching C.

2005-01-01

275

Identification in the ancient protist Giardia lamblia of two eukaryotic translation initiation factor 4E homologues with distinctive functions.  

Science.gov (United States)

Eukaryotic translation initiation factor 4E (eIF4E) binds to the m(7)GTP of capped mRNAs and is an essential component of the translational machinery that recruits the 40S small ribosomal subunit. We describe here the identification and characterization of two eIF4E homologues in an ancient protist, Giardia lamblia. Using m(7)GTP-Sepharose affinity column chromatography, a specific binding protein was isolated and identified as Giardia eIF4E2. The other homologue, Giardia eIF4E1, bound only to the m(2,2,7)GpppN structure. Although neither homologue can rescue the function of yeast eIF4E, a knockdown of eIF4E2 mRNA in Giardia by a virus-based antisense ribozyme decreased translation, which was shown to use m(7)GpppN-capped mRNA as a template. Thus, eIF4E2 is likely the cap-binding protein in a translation initiation complex. The same knockdown approach indicated that eIF4E1 is not required for translation in Giardia. Immunofluorescence assays showed wide distribution of both homologues in the cytoplasm. But eIF4E1 was also found concentrated and colocalized with the m(2,2,7)GpppN cap, 16S-like rRNA, and fibrillarin in the nucleolus-like structure in the nucleus. eIF4E1 depletion from Giardia did not affect mRNA splicing, but the protein was bound to Giardia small nuclear RNAs D and H known to have an m(2,2,7)GpppN cap, thus suggesting a novel function not yet observed among other eIF4Es in eukaryotes. PMID:15879529

Li, Lei; Wang, Ching C

2005-05-01

276

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

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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...

277

Variant surface antigens of Giardia lamblia are associated with the presence of a thick cell coat: thin section and label fracture immunocytochemistry survey.  

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Giardia lamblia undergoes surface antigenic variation. The ultrastructural location of antigens on four different variants was studied by label fracture and immunocytochemistry with four monoclonal antibodies (MAbs), each of which recognized the predominant variant in a particular clone. Each Giardia clone and its reacting MAb showed similar findings. The entire surface of the organism was covered by a surface coat which contained the variant surface protein. The surface coat was densely and ...

Pimenta, P. F.; Da Silva, P. P.; Nash, T.

1991-01-01

278

Adaptor Protein Complex 1 Mediates the Transport of Lysosomal Proteins from a Golgi-like Organelle to Peripheral Vacuoles in the Primitive Eukaryote Giardia lamblia  

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Giardia lamblia is an early branching protist that possesses peripheral vacuoles (PVs) with characteristics of lysosome-like organelles, located underneath the plasma membrane. In more evolved cells, lysosomal protein trafficking is achieved by cargo recognition involving adaptor protein (AP) complexes that recognize specific amino acid sequences (tyrosine and/or dileucine motifs) within the cytoplasmic tail of membrane proteins. Previously, we reported that Giardia has a tyrosine-based sorti...

Touz, Mari?a C.; Kulakova, Liudmila; Nash, Theodore E.

2004-01-01

279

Commercial Assay for Detection of Giardia lamblia and Cryptosporidium parvum Antigens in Human Fecal Specimens by Rapid Solid-Phase Qualitative Immunochromatography  

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The ImmunoCard STAT! Cryptosporidium/Giardia rapid assay (Meridian Bioscience, Inc.) is a solid-phase qualitative immunochromatographic assay that detects and distinguishes between Giardia lamblia and Cryptosporidium parvum in aqueous extracts of human fecal specimens (fresh, frozen, unfixed, or fixed in 5 or 10% formalin or sodium acetate-acetic acid-formalin). By using specific antibodies, antigens specific for these organisms are isolated and immobilized on a substrate. After the addition ...

Garcia, Lynne S.; Shimizu, Robyn Y.; Novak, Susan; Carroll, Marilyn; Chan, Frank

2003-01-01

280

Prevalence of Giardia lamblia with or without diarrhea in South East, South East Asia and the Far East.  

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This article is a review of the latest information on the prevalence of G. lamblia in South Asia, South East Asia and Far East, characterizing the current endemic situation within these regions. Around 33 published papers from 2002-2007 were collected on G. lamblia. The included countries were Nepal, Bangladesh, India, Cambodia, Vietnam, Malaysia, Philippines, Indonesia, Thailand, Republic of Korea, and China. Only five published papers were discarded because data was extracted before 2002-2007 or they are not included within our regions, emphasizing more on G. lamblia in animals, or performed at extensive molecular level. The prevalence of G. lamblia varied markedly between studies illustrating higher levels in the urban than in the rural areas, more among poor communities, slightly higher in males than in females with age range of 2-5-year-old children, and among university students, old-aged people, HIV-positive patients, and gastric carcinoma patients. Though G. lamblia is not a life-threatening parasite, nevertheless, it is still considered as the most common water-borne diarrhea-causing disease. It is important to understand the etiology, frequency, and consequences of acute diarrhea in children. Routine surveillance such as bi-annual follow-up treatments, treating G. duodenalis cysts and other protozoa oocysts detected in ground water sources, and continuous health education are the most preventive measures. PMID:18425689

Dib, Hassan H; Lu, Si Qi; Wen, Shao Fang

2008-07-01

 
 
 
 
281

The principal conductance in Giardia lamblia trophozoites possesses functional properties similar to the mammalian ClC-2 current.  

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The human intestinal pathogen Giardia lamblia is a flagellated unicellular protozoan with pronounced medical and biological relevance. However, the basic physiology of Giardia trophozoites has been sparsely studied, especially the electrical and ionic properties of their cellular membrane which are virtually unknown. In this study, we were able to record and characterize the macroscopic ionic currents of Giardia trophozoite membrane by electrophysiological methods of the patch clamp technique. Giardia trophozoites showed a high current density (?600 pA/pF at -140 mV) that was activated upon hyperpolarization. This current was carried by a chloride-selective channel (I Cl-G) and it was the most important determinant of the membrane potential in Giardia trophozoites. Moreover, this conductance was able to carry other halide anions and the sequence of permeability was Br(-)?>?Cl(-)???I(-)???F(-). Besides the voltage-dependent inward-rectifying nature of I Cl-G, its activation and deactivation kinetics were comparable to those observed in ClC-2 channels. Extracellular pH modified the voltage-dependent properties of I Cl-G, shifting the activation curve from a V 1/2?=?-79?±?1 mV (pH 7.4) to -93?±?2 mV (pH 8.4) and -112?±?2 mV (pH 5.4). Furthermore, the maximal amplitude of I Cl-G measured at -100 mV showed dependence to external pH in a bell-shaped fashion reported only for ClC-2 channels. Therefore, our results suggest that I Cl-G possesses several functional properties similar to the mammalian ClC-2 channels. PMID:24043571

Moreno-Galindo, Eloy G; Rodríguez-Elías, Julio C; Ramírez-Herrera, Mario A; Sánchez-Chapula, José A; Navarro-Polanco, Ricardo A

2014-05-01

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The Comparison of the Efficacy of Various Fixatives on Diverse Staining Methods of Giardia lamblia Cyst  

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Full Text Available The definite and exact diagnosis of protozoa is possible using high magnification objective lenses, provided that suitable stained smears are prepared. Therefore, the appropriateness of both fixative and staining methods to the species of parasite, which is the main objective of this study, is important. In this study, five various fixatives including (Merthiolate iodine formalin MIF, (Sodium acetate-acetic acid formalin SAF, (Polyvinyl alcohol PVA, formalin and schaudinn and four types of stains including Hematoxylin I, Hematoxylin II, Trichrome and Carbol-fuchsin were prepared using standard procedures. After the smears of stool samples containing Giadria lamblia cyst were prepared and kept for 24 h in various fixatives, the study was carried out using the four above-mentioned stains by changing the ingredients and time as well as by repeating the experiments. After fixing and staining all the smears in identical conditions along with the implementing interferences in the staining process, the following results were eventually obtained considering the morphologic indexes and negative and positive scores (from 1 to 20: formalin with 17 scores in hematoxylin I staining, formalin and SAF with 15 and 14 scores, respectively in Hematoxylin II staining, MIF with 13 scores in Trichrome staining and SAF, PVA, MIF with 11.5, 11.5 and 11 scores, respectively in carbol-fuchsin staining were found to be the best fixatives. Hematoxylin I staining using formalin fixative with 17 scores showed the best result while the maximum score for Carbol-fuchsin staining was 11.5 showing a necessity for more expenditure, time and expert cooperation to reach ideal results.

E. Badparva

2009-01-01

283

N-acetyl-D-glucosamine is present in cysts and trophozoites of Giardia lamblia and serves as receptor for wheatgerm agglutinin.  

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Previously, on the basis of lectin binding and glycosidase digestion assays, we have suggested that N-acetyl-D-glucosamine residues (GlcNAc) are major structural components of both trophozoites and in vivo cysts of the intestinal parasite Giardia lamblia. In this report we confirm that GlcNAc is present both in trophozoites and in vitro cysts as assessed by lectin binding and glycosidase digestion assays, galactosyltransferase labeling, immunochemical analysis using antibodies specific for GlcNAc and its beta 1-4 oligomers, and by gas chromatography/mass spectrometry (GC/MS). The results show that wheatgerm agglutinin (WGA) binds specifically to intact trophozoites and in vitro cysts as well as to SDS-PAGE separated proteins. WGA binding to the separated proteins was markedly reduced after their digestion with N-acetyl-beta-D-glucosaminidase, supporting the conclusion that WGA is reacting with terminal beta-linked GlcNAc residues. Labeling of trophozoites and cysts by 3H-exogalactosylation with galactosyltransferase further confirmed the presence of terminal GlcNAc in both surface and intracellular glycoproteins. The presence of GlcNAc is also supported by microfluorometric analysis using antibodies to (GlcNAc)1, (GlcNAc)2, and (GlcNAc)3, which revealed a sugar-inhibitable binding of the antibody to live trophozoites. Finally, the presence of GlcNAc in both cysts and trophozoites was unequivocally confirmed by GC/MS analysis of detergent-extracted membranes and of glycoproteins isolated by affinity chromatography on WGA-agarose. GC/MS analysis also revealed mannose (Man), N-acetyl-D-galactosamine (GalNAc), fucose (Fuc), galactose (Gal), glucose (Glc) and N-acetylneuraminic acid (NANA) to be present in cysts. All these sugars were also present in trophozoites, except for GalNAc. The glycoproteins isolated by WGA affinity chromatography were 5- to 40-fold enriched in GlcNAc, further supporting the conclusion that WGA reacts with GlcNAc in Giardia. In summary, the data presented here provide biological and chemical evidence for GlcNAc in both cysts and trophozoites of G. lamblia and are consistent with previously published results from this and other laboratories. PMID:2128647

Ortega-Barria, E; Ward, H D; Evans, J E; Pereira, M E

1990-12-01

284

Identification of chitin as a structural component of Giardia cysts.  

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The intestinal parasite Giardia lamblia is a significant cause of diarrheal disease, which is perpetuated by the infective cyst form of the parasite. Although a rational approach to the control of giardiasis would be to inhibit cyst formation, nothing is known of the chemical composition of the cyst wall or of its biosynthesis. In these studies, we have shown that chitin is a major structural component of G. lamblia and G. muris cyst walls. This conclusion is based on the finding that chitina...

Ward, H. D.; Alroy, J.; Lev, B. I.; Keusch, G. T.; Pereira, M. E.

1985-01-01

285

Characteristics and risk factors for symptomatic Giardia lamblia infections in Germany  

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Abstract Background In developed countries, giardiasis is considered a travel related disease. However, routine surveillance data from Germany indicate that >50% of infections were acquired indigenously. We studied the epidemiological characteristics of symptomatic Giardia infections acquired in Germany and abroad, and verified the proportion of cases acquired in Germany in order to investigate risk factors for sporadic autochthonous Giardia infections. ...

Espelage Werner; an der Heiden Matthias; Stark Klaus; Alpers Katharina

2010-01-01

286

Release of metabolic enzymes by Giardia in response to interaction with intestinal epithelial cells.  

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Giardia lamblia, an important cause of diarrheal disease, resides in the small intestinal lumen in close apposition to epithelial cells. Since the disease mechanisms underlying giardiasis are poorly understood, elucidating the specific interactions of the parasite with the host epithelium is likely to provide clues to understanding the pathogenesis. Here we tested the hypothesis that contact of Giardia lamblia with intestinal epithelial cells might lead to release of specific proteins. Using ...

Ringqvist, E.; Palm, J. E. D.; Skarin, H.; Hehl, A. B.; Weiland, M.; Davids, B. J.; Reiner, D. S.; Griffiths, W. J.; Eckmann, L.; Gillin, F. D.; Sva?rd, S. G.

2008-01-01

287

Occurence of Giardia lamblia in children of municipal day-care centers from Botucatu, São Paulo State, Brazil Ocorrência de Giardia lamblia em crianças atendidas em creches municipais de Botucatu, Estado de São Paulo, Brasil  

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Full Text Available Considering that the number of day-care centers for pre-school-age children has expanded rapidly in developing countries, and that these institutions presenting conditions that facilitate the transmission of many enteric agents, a parasitological survey was carried out in three municipal day-cares from Botucatu: two in the urban area (one in downtown area and the other one in the city periphery area and the third in the rural area. Three separate stool specimens were collected from 147 children ranging from 0 to 72 months old and 20 staff members. Each stool specimen was processed by Lutz and zinc sulfate flotation methods. The frequency of giardiasis observed among children of downtown, periphery and rural day-cares was 69.6%, 52.7% and 69.6%, respectively. Only one employee was positive for G. lamblia. The examination of three stool specimens increased the positivity for G. lamblia: from the ninety three final positive examinations, 24 (25.5% and 8 (8.5% were positives only after examination of the second and third samples, respectively. Others intestinal organisms like Ascaris lumbricoides (20.4%, Trichuris trichiura (19.0%. Hymenolepis nana (8.8%, Entamoeba coli (22.4% and Blastocystis hominis (32.0% were frequently found in the children. There was no significant association among localization of the day-cares, sex of the children and the levels of G. lamblia infection. According to the age, G. lamblia was found mainly in children between 12 to 47 months old.Foi realizado um levantamento parasitológico em três creches da rede municipal: duas na área urbana, uma no centro da cidade e a outra na periferia, e a terceira na zona rural. Três amostras de fezes, coletadas com intervalo de 7 dias, foram obtidas de 147 crianças com idade variando de 0 a 6 anos e de 20 funcionários. Cada amostra foi processada pelos métodos de sedimentação espontânea e centrífugo - flutuação com sulfato de zinco. Os resultados demonstraram que das 147 crianças examinadas, 93 (63,3% apresentaram cistos de G. lamblia nas fezes. Apenas 1 funcionário foi positivo para G. lamblia. O uso de 3 amostras de fezes aumentou a positividade do exame para o diagnóstico deste parasita, uma vez que dos 93 casos positivos, 24 (25,5% e 8 (8,5% foram diagnosticados somente após exame da segunda e terceira amostras, respectivamente. Outros parasitas e comensais intestinais como Ascaris lumbricoides (20,4%, Trichuris trichiura (19,0%, Hymenolepis nana (8,8%, Entamoeba coli (22,4% e Blastocystis hominis (32,0% foram diagnosticados. A análise estatística revelou não haver associação entre localização das creches, sexo e a frequência de infecção por G. lamblia. As porcentagens mais altas de infecção por Giardia foram observadas entre as crianças com idade variando de 1 a 4 anos.

Semíramis Guimarães

1995-12-01

288

Host-Pathogen Responses during Giardia infections  

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Giardia lamblia is a eukaryotic parasite of the upper small intestine of humans and animals. The infecting trophozoite cells do not invade the epithelium lining of the intestine, but attach to the brush border surface in the intestinal lumen. The giardiasis disease in humans is highly variable. Prior to this study, the molecular mechanisms involved in establishment of infection or cause of disease were largely uncharacterized. In this thesis, the molecular relationship between Giardia and the...

Ringqvist, Emma

2009-01-01

289

Parasitismo por Giardia sp. e Cryptosporidium sp. em Coendou villosus / Parasitism by Giardia sp. and Cryptosporidium sp. in Coendou villosus  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi verificar o possível parasitismo por Giardia sp. e Cryptosporidium sp. em amostras de fezes de ouriço-cacheiro (Coendou villosus). As amostras foram analisadas pelo método de centrífugo-flutuação com sulfato de zinco e apresentaram elevada infecção por cistos de Giardia [...] sp. e por oocistos de Cryptosporidium sp., embora os animais não apresentassem sinal clínico decorrente disso. Abstract in english This research was aimed at verifing the possible parasitism by Giardia sp. and Cryptosporidium sp. in porcupine (Coendou villosus) faeces samples. Samples were analyzed by the centrifugal-flotation method with zinc sulphate and showed high infection by cysts of Giardia sp. and by oocysts of Cryptosp [...] oridium sp., although the animals did not show any associated clinical sign.

João Fabio, Soares; Aleksandro Schafer da, Silva; Camila Belmonte, Oliveira; Marcos Kipper da, Silva; Gleide, Mariscano; Edson Luis, Salomão; Silvia Gonzalez, Monteiro.

290

Parasitismo por Giardia sp. e Cryptosporidium sp. em Coendou villosus Parasitism by Giardia sp. and Cryptosporidium sp. in Coendou villosus  

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Full Text Available O objetivo deste trabalho foi verificar o possível parasitismo por Giardia sp. e Cryptosporidium sp. em amostras de fezes de ouriço-cacheiro (Coendou villosus. As amostras foram analisadas pelo método de centrífugo-flutuação com sulfato de zinco e apresentaram elevada infecção por cistos de Giardia sp. e por oocistos de Cryptosporidium sp., embora os animais não apresentassem sinal clínico decorrente disso.This research was aimed at verifing the possible parasitism by Giardia sp. and Cryptosporidium sp. in porcupine (Coendou villosus faeces samples. Samples were analyzed by the centrifugal-flotation method with zinc sulphate and showed high infection by cysts of Giardia sp. and by oocysts of Cryptosporidium sp., although the animals did not show any associated clinical sign.

João Fabio Soares

2008-04-01

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

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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: di...

Garcia, L. S.; Shimizu, R. Y.

1997-01-01

292

CYTOCHEMICAL METHODS FOR ASSESSING 'GIARDIA' CYST VIABILITY  

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Giardia lamblia is the most common human intestinal protozoan parasite reported in the United States and England. The objective of the study was to develop a practical, reliable, rapid, microscopically-read method, comparable to excystation for determining the viability of Giardi...

293

Giardia y giardiasis Giardia and giardiasis  

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Full Text Available Giardia lamblia es un protozoario parásito que habita el intestino delgado de los seres humanos y de muchos otros vertebrados y es una de las más comunes causas de diarrea en todo el mundo. Durante su ciclo de vida Giardia sufre significativos cambios bioquímicos y morfológicos que le permiten sobrevivir en ambientes y condiciones que de otro modo lo destruirían. Para sobrevivir fuera del intestino del hospedador, los trofozoítos de Giardia se diferencian a quistes, los que se caracterizan por poseer una rígida pared glicoproteica externa que les permiten sobrevivir inclusive frente a la acción de los desinfectantes más comunes. Otro de los mecanismos de adaptación de este parásito es la variación de los antígenos de superficie que le permite a los trofozoítos evadir la respuesta inmune del huésped y generar infecciones tanto agudas como crónicas o recurrentes en individuos infectados. Durante los últimos años se han producido importantes avances en el conocimiento de las bases moleculares de los procesos de enquistamiento y variación antigénica en Giardia que pronostican el pronto hallazgo de nuevos agentes quimioterapéuticos y/o inmunoprofilácticos contra este importante parásito intestinal.Giardia lamblia is a protozoan parasite that inhabits the upper small intestine of humans and several other vertebrates and one of the most frequent cause of intestinal disease worldwide. During its life cycle, G. lamblia undergoes significant biochemical and morphological changes that allow the parasite to survive under hostile environmental conditions. To survive outside the host’s intestine, Giardia differentiates into resistant cysts, which are characterized by a rigid extracellular cyst wall that protect the parasite even to the action of the most common chemical disinfectants. Another adaptive mechanism of Giardia is the switching of its surface antigens, a mechanism that allows the trophozoites to evade the host’s immune responses and produce acute, chronic and/or recurrent infections. During the last years, important advances in the knowledge of the molecular basis underlying the mechanisms of encystation and antigenic variation in Giardia suggest that novel chemotherapeutic and/or immunoprophylactic reagents against this important human pathogen could soon be available.

Hugo D. Luján

2006-02-01

294

Molecular & Biochemical Parasitology Release of metabolic enzymes by Giardia in response to interaction with intestinal epithelial cells  

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Giardia lamblia, an important cause of diarrheal disease, resides in the small intestinal lumen in close apposition to epithelial cells. Since the disease mechanisms underlying giardiasis are poorly understood, elucidating the specific interactions of the parasite with the host epithelium is likely to provide clues to understanding the pathogenesis. Here we tested the hypothesis that contact of Giardia lamblia with intestinal epithelial cells might lead to release of specific proteins. Using ...

Ringqvist, Emma; Palm, J. E. Daniel; Skarin, Hanna; Hehl, Adrian B.; Weiland, Malin; Davids, Barbara J.; Reiner, David S.; Griffiths, William J.; Eckmann, Lars; Gillin, Frances D.; Sva?rd, Staffan G.

2008-01-01

295

Sheep May Not Be an Important Zoonotic Reservoir for Cryptosporidium and Giardia Parasites  

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Little is known of the prevalence of Cryptosporidium and Giardia parasites in sheep and the genotypes that they harbor, although potentially sheep may contribute significantly to contamination of watersheds. In the present study, conducted in Western Australia, a total of 1,647 sheep fecal samples were screened for the presence of Cryptosporidium and Giardia spp. using microscopy, and a subset (n = 500) were screened by PCR and genotyped. Analysis revealed that although both parasites were de...

Ryan, Una M.; Bath, Caroline; Robertson, Ian; Read, Carolyn; Elliot, Aileen; Mcinnes, Linda; Traub, Rebecca; Besier, Brown

2005-01-01

296

Simultaneous expression of different variant-specific surface proteins in single Giardia lamblia trophozoites during encystation.  

Science.gov (United States)

A novel variant-specific surface protein (VSP) from Giardia was identified using the monoclonal antibody 9B10, raised against purified cyst walls. VSP9B10B is preferentially induced during encystation and expressed simultaneously with other VSPs on the surface of encysting trophozoites. These results support the hypothesis that encystation and antigenic variation are processes that are mechanistically related. PMID:12183579

Carranza, Pedro G; Feltes, Gisela; Ropolo, Andrea; Quintana, Silvia M C; Touz, María C; Luján, Hugo D

2002-09-01

297

Simultaneous Expression of Different Variant-Specific Surface Proteins in Single Giardia lamblia Trophozoites during Encystation  

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A novel variant-specific surface protein (VSP) from Giardia was identified using the monoclonal antibody 9B10, raised against purified cyst walls. VSP9B10B is preferentially induced during encystation and expressed simultaneously with other VSPs on the surface of encysting trophozoites. These results support the hypothesis that encystation and antigenic variation are processes that are mechanistically related.

Carranza, Pedro G.; Feltes, Gisela; Ropolo, Andrea; Quintana, Silvia M. C.; Touz, Mari?a C.; Luja?n, Hugo D.

2002-01-01

298

Identification of Obscure yet Conserved Actin-Associated Proteins in Giardia lamblia.  

Science.gov (United States)

Consistent with its proposed status as an early branching eukaryote, Giardia has the most divergent actin of any eukaryote and lacks core actin regulators. Although conserved actin-binding proteins are missing from Giardia, its actin is utilized similarly to that of other eukaryotes and functions in core cellular processes such as cellular organization, endocytosis, and cytokinesis. We set out to identify actin-binding proteins in Giardia using affinity purification coupled with mass spectroscopy (multidimensional protein identification technology [MudPIT]) and have identified >80 putative actin-binding proteins. Several of these have homology to conserved proteins known to complex with actin for functions in the nucleus and flagella. We validated localization and interaction for seven of these proteins, including 14-3-3, a known cytoskeletal regulator with a controversial relationship to actin. Our results indicate that although Giardia lacks canonical actin-binding proteins, there is a conserved set of actin-interacting proteins that are evolutionarily indispensable and perhaps represent some of the earliest functions of the actin cytoskeleton. PMID:24728194

Paredez, Alexander R; Nayeri, Arash; Xu, Jennifer W; Krtková, Jana; Cande, W Zacheus

2014-06-01

299

Atrofia Villositaria Duodenal, un Hallazgo Inesperadamente Frecuente en Infestación por Giardia Lamblia / Duodenal villous atrophy, an unexpectedly common finding in giardia lamblia infestation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish OBJETIVO: Estudiar la presencia y frecuencia de los cambios histopatológicos tales como atrofia villositaria, linfocitosis intraepitelial, hiperplasia linfoide nodular y presencia de eosinófilos en biopsis duodenales informadas como Giardiasis. METODOLOGÍA: Se recolectó todos los casos diagnosticado [...] s como giardiasis duodenal durante el período 2005 a 2009 en 5 diferentes servicios de anatomía patológica y fueron revisados por un grupo de patólogos. RESULTADOS: Se incluyeron 30 casos. Se observó atrofia de las vellosidades en el 61,2%, incremento de linfocitos intraepiteliales en 63,3%, presencia de folículos linfoides en el 43,3% el promedio de eosinófilos en lámina propia por campo de alto poder fue aprox. 7. DISCUSIÓN: Nuestro porcentaje de atrofia villositaria es mucho mayor que lo reportado por otros autores, los casos con atrofia presentaron mayor frecuencia de linfocitosis 83,3% que los casos sin atrofia. (30%). Este hallazgo coincide con la relación directa entre linfocitos intraepiteliales /atrofia de vellosidades descrita por varios autores. Ninguno de los casos con hiperplasia linfoide, presentó ausencia de células plasmáticas que nos hiciera sospechar histológicamente de algún tipo de inmunodepresión humoral. El número de eosinófilos encontrado fue levemente elevado. Abstract in english OBJECTIVE: To study the histological changes observed in Giardia positive biopsies obtained from the duodenum.: The number of intraepithelial lymphocytes (IEL), grade of villous atrophy, presence of lymph follicles and number of eosinophils in the lamina propria per HPF were assessed. METHODS: All g [...] iardia positive biopsies diagnosed during period 2005-2009 in 5 pathology units were reevaluated by a group of pathologists. RESULTS: Thirty cases were included. Atrophic villous architecture was seen in 61,2%, increase in number of intraepithelial lymphocytes in 63,3% The occurrence of lymphoid follicles in 43,3%. DISCUSSION: Villous atrophy was higher than reported by others authors, cases with atrophy showed greater frequency of increase in the number of intraepithelial lymphocytes than cases without atrophy. No cases with lymph follicle showed lack of plasmatic cells, the number of eosinophils was subtly increased.

Fernando, Arévalo; Violeta, Aragón; Domingo, Morales L.; Domingo, Morales Caramutti; Jannitza, Arandia; Gabriel, Alcocer.

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Quantitative assessment of sense and antisense transcripts from genes involved in antigenic variation (vsp genes) and encystation (cwp 1 gene) of Giardia lamblia clone GS/M-83-H7.  

Science.gov (United States)

Antigenic variation of the intestinal protozoan parasite Giardia lamblia is caused by an exchange of the parasite's variant surface protein (VSP) coat. Many investigations on antigenic variation were performed with G. lamblia clone GS/M-83-H7 which produces surface antigen VSP H7. To generate novel information on giardial vsp gene transcription, vsp RNA levels were assessed by quantitative reverse transcription-(RT)-PCR in both axenic VSP H7-type trophozoites and subvariants obtained after negative selection of GS/M-83-H7 trophozoites by treatment with a cytotoxic, VSP H7-specific monoclonal antibody. Our investigation was not restricted to the assessment of the sense vsp transcript levels but also included an approach aimed at the detection of complementary antisense vsp transcripts within the two trophozoite populations. We found that sense vsp H7 RNA predominated in VSP H7-type trophozoites while sense RNA from only one (vsp IVg) of 8 subvariant vsp genes totally analysed predominated in subvariant-type trophozoites. Interestingly, the two trophozoite populations exhibited a similar relative distribution regarding the vsp H7 and vsp IVg antisense RNA molecules. An analogous sense versus antisense RNA pattern was also observed when the transcripts of gene cwp 1 (encoding cyst wall protein 1) were investigated. Here, both types of RNA molecules only appeared after cwp 1 had been induced through in vitro encystation of the parasite. These findings for the first time demonstrated that giardial antisense RNA production did not occur in a constitutive manner but was directly linked to complementary sense RNA production after activation of the respective gene systems. PMID:15830812

von Allmen, N; Bienz, M; Hemphill, A; Müller, N

2005-04-01

 
 
 
 
301

Lipid metabolism in Giardia: a post-genomic perspective  

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Giardia lamblia, a protozoan parasite, infects a wide variety of vertebrates, including humans. Studies indicate that this anaerobic protist possesses a limited ability to synthesize lipid molecules de novo and depends on supplies from its environment for growth and differentiation. It has been suggested that most lipids and fatty acids are taken up by endocytic and non-endocytic pathways and are used by Giardia for energy production and membrane/organelle biosynthesis. The purpose of this ar...

Yichoy, M.; Duarte, T. T.; Chatterjee, A.; Mendez, T. L.; Aguilera, K. Y.; Roy, D.; Roychowdhury, S.; Aley, S. B.; Das, S.

2011-01-01

302

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

Energy Technology Data Exchange (ETDEWEB)

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 to 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.

Z Li; Z Liu; D Cho; J Zou; M Gong; R Breece; A Galkin; L Li; H Zhao; et al.

2011-12-31

303

Giardia and Pets  

Science.gov (United States)

... CDC.gov . Parasites - Giardia Parasites Home Share Compartir Giardia and Pets On this Page Can I get ... and treatment information for humans. Can I get Giardia infection from my pet? The risk of humans ...

304

Disaccharidase activity in the small intestine of gerbils (Meriones unguiculatus) during primary and challenge infections with Giardia lamblia.  

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The sequence of changes in the activity of six disaccharidases in the small intestine of gerbils during primary and secondary G lamblia infections was examined. The primary G lamblia infection induced a transient reduction in disaccharidase activity which was related to the highest trophozoite burden in the small intestine. During the primary exposure, a 30% to 85% decrease in the activity of enzymes was observed on days 10 and 20 after infection. Secondary exposure of gerbils to G lamblia ca...

Belosevic, M.; Faubert, G. M.; Maclean, J. D.

1989-01-01

305

A Novel Giardia lamblia Nitroreductase, GlNR1, Interacts with Nitazoxanide and Other Thiazolides?  

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The nitrothiazole analogue nitazoxanide [NTZ; 2-acetolyloxy-N-(5-nitro-2-thiazolyl)benzamide] represents the parent compound of a class of drugs referred to as thiazolides and exhibits a broad spectrum of activities against a wide variety of helminths, protozoa, and enteric bacteria infecting animals and humans. NTZ and other thiazolides are active against a wide range of other intracellular and extracellular protozoan parasites in vitro and in vivo, but their mode of action and respective su...

Mu?ller, Joachim; Wastling, Jonathan; Sanderson, Sanya; Mu?ller, Norbert; Hemphill, Andrew

2007-01-01

306

Giardia Infections  

Science.gov (United States)

... is an illness caused by a parasite called Giardia intestinalis. It lives in soil, food, and water. ... poop) through sexual contact. The risk of getting giardia is higher for travelers to countries where it ...

307

NL MIND-BEST: a web server for ligands and proteins discovery--theoretic-experimental study of proteins of Giardia lamblia and new compounds active against Plasmodium falciparum.  

Science.gov (United States)

There are many protein ligands and/or drugs described with very different affinity to a large number of target proteins or receptors. In this work, we selected Ligands or Drug-target pairs (DTPs/nDTPs) of drugs with high affinity/non-affinity for different targets. Quantitative Structure-Activity Relationships (QSAR) models become a very useful tool in this context to substantially reduce time and resources consuming experiments. Unfortunately most QSAR models predict activity against only one protein target and/or have not been implemented in the form of public web server freely accessible online to the scientific community. To solve this problem, we developed here a multi-target QSAR (mt-QSAR) classifier using the MARCH-INSIDE technique to calculate structural parameters of drug and target plus one Artificial Neuronal Network (ANN) to seek the model. The best ANN model found is a Multi-Layer Perceptron (MLP) with profile MLP 20:20-15-1:1. This MLP classifies correctly 611 out of 678 DTPs (sensitivity=90.12%) and 3083 out of 3408 nDTPs (specificity=90.46%), corresponding to training accuracy=90.41%. The validation of the model was carried out by means of external predicting series. The model classifies correctly 310 out of 338 DTPs (sensitivity=91.72%) and 1527 out of 1674 nDTP (specificity=91.22%) in validation series, corresponding to total accuracy=91.30% for validation series (predictability). This model favorably compares with other ANN models developed in this work and Machine Learning classifiers published before to address the same problem in different aspects. We implemented the present model at web portal Bio-AIMS in the form of an online server called: Non-Linear MARCH-INSIDE Nested Drug-Bank Exploration & Screening Tool (NL MIND-BEST), which is located at URL: http://miaja.tic.udc.es/Bio-AIMS/NL-MIND-BEST.php. This online tool is based on PHP/HTML/Python and MARCH-INSIDE routines. Finally we illustrated two practical uses of this server with two different experiments. In experiment 1, we report by first time Quantum QSAR study, synthesis, characterization, and experimental assay of antiplasmodial and cytotoxic activities of oxoisoaporphine alkaloids derivatives as well as NL MIND-BEST prediction of potential target proteins. In experiment 2, we report sampling, parasite culture, sample preparation, 2-DE, MALDI-TOF, and -TOF/TOF MS, MASCOT search, MM/MD 3D structure modeling, and NL MIND-BEST prediction for different peptides a new protein of the found in the proteome of the human parasite Giardia lamblia, which is promising for anti-parasite drug-targets discovery. PMID:21277861

González-Díaz, Humberto; Prado-Prado, Francisco; Sobarzo-Sánchez, Eduardo; Haddad, Mohamed; Maurel Chevalley, Séverine; Valentin, Alexis; Quetin-Leclercq, Joëlle; Dea-Ayuela, María A; Teresa Gomez-Muños, María; Munteanu, Cristian R; José Torres-Labandeira, Juan; García-Mera, Xerardo; Tapia, Ricardo A; Ubeira, Florencio M

2011-05-01

308

Presencia de Giardia lamblia y Cryptosporidium spp. en aguas residuales depuradas reutilizadas para riego agrícola en la isla de Tenerife, España. Efectos del transporte a larga distancia sobre la calidad del agua reutilizada Giardia lamblia and Cryptosporidium spp. Presence in treated wastewater reutilised for irrigation in Tenerife island, Spain. Long-distance transport effects in the reutilised water quality  

Directory of Open Access Journals (Sweden)

Full Text Available El empleo de aguas residuales depuradas para riego agrícola es la alternativa de reutilización con más relevancia hoy día, siempre y cuando se desarrolle con garantías sanitarias y medioambientales.Giardia lamblia y Cryptosporidium spp. son dos protozoos patógenos entéricos de amplia distribución ambiental, frecuentes en hábitats acuáticos. La investigación y detección de estos parásitos en aguas ha adquirido importancia en los últimos años debido a que poseen formas de dispersión resistentes a los tratamientos habituales, aplicados tanto en procesos de potabilización como de depuración, y a que han sido clasificados como patógenos emergentes causantes de importantes brotes de transmisión hídrica.En este trabajo se estudia la presencia de quistes de Giardia lamblia y ooquistes de Cryptosporidium spp. en el agua residual depurada de la ciudad de Santa Cruz de Tenerife que es transportada hasta el sur de la isla de Tenerife para su reutilización en agricultura. Asimismo se investiga el efecto del transporte, el almacenamiento y el tratamiento avanzado sobre la concentración de quistes y ooquistes a través del sistema, y la existencia de relaciones con otros parámetros bacteriológicos y físico-químicos.Los resultados obtenidos ponen de manifiesto comportamientos variables de los contenidos en quistes y ooquistes frente a los tratamientos aplicados, y el efecto depurador que el transporte a larga distancia, parece tener sobre el agua residual depurada.No se han encontrado relaciones entre las concentraciones de quistes y ooquistes en el agua residual depurada y el contenido de los indicadores tradicionales de contaminación fecal.Treated wastewater use for irrigation is, nowadays, the more relevant reutilization alternative of wastewater, if it is developed with sanitary and environmental warranties.Giardia lamblia and Cryptosporidium spp. two wide distributed enteric pathogen protozoan, which are frequent in aquatic habitats. These protozoan investigation and detection have acquired importance in the last years due to their dispersion forms, which show resistance to the habitual treatments of potabilization and purification, and their classification as emerging pathogens which are the causative agents of important hydrical transmission outbreaks.In our work, Giardia lamblia cyst and Cryptosporidium spp. oocyst presence in Santa Cruz de Tenerife treated wastewater which is transported to the South of the island to be reutilised in agriculture. Furthermore, transport, storage and advanced treatment effects against cyst and oocyst concentration throughout the system and relation existence with other bacteriological and physical-chemical parameters, are also investigated.The obtained results demonstrate variable behaviours in cyst and oocyst concentration against applied treatments, and the depurative effect of the long-distance transport which seems to have in treated wastewater.There was not found any relation between cyst and oocyst concentration in treated wastewater and the traditional indicators of faecal contamination.

Escolástico Aguiar González

2002-06-01

309

DETECTION OF GIARDIA MURIS AND GIARDIA LAMBLIA CYSTS BY IMMUNOFLUORESCENCE IN ANIMAL TISSUES AND FECAL SAMPLES SUBJECTED TO CYCLES OF FREEZING AND THAWING  

Science.gov (United States)

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). iardia muris cysts were obtained from either animal carcasses, fecal pellet...

310

Impacto de la dieta sobre la inducción de infección con quistes de Giardia lamblia en ratas Sprague-Dawley The effect of malnourishment on the development of giardiosis in Sprague-Dawley rats  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo. Evaluar el efecto de la desnutrición en la inducción de la giardiosis con diferentes concentraciones de quistes de Giardia lamblia utilizando como modelo animal ratas Sprague-Dawley. Material y métodos. Es un estudio experimental efectuado entre 1995 y 1999, en el Centro de Investigación en Alimentación y Desarrollo, de la ciudad de Hermosillo, estado de Sonora, México, y cuya muestra estuvo integrada por dos grupos de 6 a 8 unidades experimentales, las cuales recibieron dos tipos de dieta y cinco tratamientos con diferente concentración de inóculo de quistes de Giardia lamblia. Durante la fase experimental se monitoreó la excreción de quistes, ganancia de peso, consumo de alimento, análisis del contenido intestinal y daños macro y microscópicos en mucosa intestinal. El tratamiento estadístico de los datos consistió en análisis de varianza, y de residuales cuando fue necesario. Resultados. En los animales alimentados con una dieta que cubre sus requerimientos nutricionales (DN se observó que es posible provocar la infección con 60 quistes, mientras que en los animales desnutridos (dieta DLN la concentración que se requiere es de únicamente seis quistes para establecer daños a nivel de mucosa intestinal. Conclusiones. La ganancia de peso monitoreada durante los 10 días de ensayo no resultó ser un buen indicador de la infección por Giardia lamblia. El porcentaje de infección depende de la concentración de quistes inoculados y del estado de nutrición de los animales evaluados.Objective. To assess the effect of malnutrition on the development of giardiosis in Sprague-Dawley rats, using different inoculum sizes of Giardia lamblia cysts. Material and Methods. An experimental study was conducted between 1995 and 1999 at Centro de Investigación, Alimentación y Desarrollo (Center for Research, Food, and Development, in Hermosillo, Sonora, Mexico. The study population consisted of two groups of six to eight experimental units that were fed two different diets and inoculated five different concentrations of Giardia lamblia cysts. Data were collected on excretion of cysts, weight gain, food intake, bowel contents, and macro and microscopic lesions in the intestinal mucosa. Statistical analysis consisted of analysis of variance and residuals. Results. Animals fed with a diet meeting nutritional requirements required an infecting inoculum of 60 cysts, while malnourished rats required only six cysts to develop mucosal lesions. Conclusions. Weight gain monitored during ten days was not a good indicator of Giardia lamblia infection. Infection depended on cyst inoculum size as well as on the nutritional status of the tested animals.

Martha Elvia Díaz-Cinco

2002-07-01

311

Giardia and Drinking Water from Private Wells  

Science.gov (United States)

... can I remove Giardia from my drinking water? Giardia and Drinking Water from Private Wells What is ... visit CDC's Giardia website. Where and how does Giardia get into drinking water? Millions of Giardia parasites ...

312

Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells  

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In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consum...

2012-01-01

313

Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells  

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In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the host´s production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively cons...

2012-01-01

314

OBSERVATION ON THE INTESTINAL PARASITIC INFECTIONS  

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During 1980-82, a total number of 4143 stool samples, from 2332 males and 1811 females, referred to the Central Laboratory of the School of Public Health, were examined for intestinal parasites. All the specimens were examined for intestinal parasites. All the specimens were examined by formol-ether concentration and wet-mount (ringer solution) techniques. The main prevalent pathogenic parasites were Entamoeba histolytica (8.7%), Giardia lamblia (16.1%), and Hymenolepis nana (3.2%). The overa...

Rezaeian, M.

1986-01-01

315

Review of Zoonotic Parasites in Medical and Veterinary Fields in the Republic of Korea  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., ...

Youn, Heejeong

2009-01-01

316

Evaluation of rapid commercial enzyme immunoassay for detection of Giardia lamblia in formalin-preserved stool specimens.  

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Two hundred twenty-three formalin-preserved stool specimens were evaluated by using ProSpecT Giardia Rapid Assay (membrane bound) (Alexon, Inc., Sunnyvale, Calif.). Enzyme immunoassay (EIA) results were compared with those by conventional microscopic examination. Two hundred four specimens were negative by both methods, and 13 (6.3%) were positive. Five specimens were negative by initial microscopic exam and positive by EIA; three of these specimens were found to be positive upon extensive mi...

Scheffler, E. H.; Etta, L. L.

1994-01-01

317

Reduced expression of maturation markers in bovine dendritic cells after incubation with Giardia duodenalis trophozoites  

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Giardia duodenalis (syn. G. intestinalis, G. lamblia) is an important intestinal parasite in a wide range of mammals, including farm animals, companion animals and humans. The role of dendritic cells in the immune response against G. duodenalis is poorly documented and has only been studied in the mouse, which is not a natural host for this parasite. The objective of this study was to investigate whether G. duodenalis trophozoites or their excretion/secretion (ES) products activate and mature...

2011-01-01

318

Parasitic Contamination of Raw Vegetables in Shahroud, Semnan  

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Background: Given the importance of healthy vegetables, the present study was conducted to determine parasitic infection of vegetable consumed in Shahroud.Materials and Methods: This cross-sectional study has been conducted on 92 samples of various vegetables collected from 16 vegetable growing farms and 1 vegetable process workshop. Results: Sixty two percent of tested vegetables lacked parasites and the highest amount of parasites observed (34.78%) was related to Giardia lamblia. A signific...

2012-01-01

319

Parasite detection efficiencies of five stool concentration systems.  

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Fresh fecal material that was free of ova and parasites was pooled with 10% Formalin in a 1:4 ratio to prepare a standard specimen. Portions of 100 ml of this specimen were individually seeded with Cryptosporidium oocysts, Entamoeba coli, Entamoeba histolytica, and Giardia lamblia cysts; ova of Necator americanus; and Strongyloides larvae. Appropriate volumes of each parasite suspension were used to evaluate the Fecal Concentrator Kit (Remel, Lenexa, Kans.), Fecal Parasite Concentrator (Everg...

Perry, J. L.; Matthews, J. S.; Miller, G. R.

1990-01-01

320

Parasitic Prevalence in a Suburban School of Famaillá, Tucumán, Argentina  

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Prevalence of intestinal parasites was investigated in rural primary school children in Famaillá city, Tucumán province, Argentina. Stool specimens from 149 school children were collected. The prevalence rate of intestinal parasite infections was 86.6%. No significant differences were observed in the distribution by age or by sex. Blastocystis hominis was the most commonly found protozoan parasite (54.4%), followed by Entamoeba coli (35.6%), Giardia lamblia (24.8%), and others (16.7%). Ente...

Dib, Julia?n; Oquilla, Juana; Lazarte, Silvia G.; Gonzalez, Silvia N.

2012-01-01

 
 
 
 
321

Detección de parásitos intestinales en agua y alimentos de Trujillo, Perú / Detection of water-Borne and food-borne intestinal parasites of Trujillo, Perú  

Scientific Electronic Library Online (English)

Full Text Available SciELO Peru | Language: Spanish Abstract in spanish Detectamos distintas especies de parásitos intestinales, tanto protozoos como helmintos, presentes en muestras de agua provenientes de acequias y pozos (Giardia lamblia, Blastocystis hominis, Entamoeba coli, Cyclospora cayetanensis, Cryptosporidium spp. y Balantidium coli), así como en alimentos cru [...] dos y cocidos (Giardia lamblia, Cyclospora cayetanensis., Endolimax nana, Iodamoeba butschlii y Blastocystis hominis Fasciola hepatica y Ascaris lumbricoides) recolectadas en varios distritos de la provincia de Trujillo, Perú. Abstract in english We report the detection of different intestinal parasites, protozoan and helminthes, in samples of water from ditches and wells (Giardia lamblia, Blastocystis hominis, Entamoeba coli, Cyclospora cayetanensis, Cryptosporidium spp. y Balantidium coli), as well as in raw and cooked foods (Giardia lambl [...] ia, Cyclospora cayetanensis., Endolimax nana, Iodamoeba butschlii y Blastocystis hominis Fasciola hepatica y Ascaris lumbricoides) collected in several districts of the province of Trujillo, Peru.

Pérez-Cordón, Gregorio; Rosales, María J.; Valdez, Renzo A.; Vargas-Vásquez, Franklin; Cordova, Ofelia.

322

Evaluation of PCR, nested PCR, and fluorescent antibodies for detection of Giardia and Cryptosporidium species in wastewater.  

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Giardiasis and cryptosporidiosis are diseases caused by the protozoan parasites Giardia lamblia and Cryptosporidium parvum. Waterborne transmission of these organisms has become more prevalent in recent years, and regulatory agencies are urging that source and finished water be screened for these organisms. A major problem associated with testing for these organisms is the lack of reliable methodologies and baseline information on the prevalence of these parasites in various water sources. Ou...

Mayer, C. L.; Palmer, C. J.

1996-01-01

323

The molecular mechanisms of giardia encystation.  

Science.gov (United States)

The protozoan parasite Giardia lamblia is transmitted as an environmentally resistant cyst. The encystation process is attracting attention not only from the viewpoint of disease transmission, but also as a model for differentiation. Here, Hugo Luján, Michael Mowatt and Theodore Nash discuss molecular events underlying this process, including the induction of expression and transport of cyst wall proteins and the induction of Golgi-like activity. They also propose that the signal for encystation derives from cholesterol deprivation in the lower small intestine. PMID:17040845

Luján, H D; Mowatt, M R; Nash, T E

1998-11-01

324

Evaluation of a Screening Test for Detection of Giardia and Cryptosporidium Parasites ?  

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The Giardia/Cryptosporidium Chek test (TechLab, Inc.), a screening test for Giardia and Cryptosporidium, was evaluated with 136 fecal samples. Using the results of the Giardia II test and Cryptosporidium II test as gold standards, it was 98.4% sensitive and 100% specific and had positive and negative predictive values of 98.7% and 99.3%.

Youn, Sojin; Kabir, Mamun; Haque, Rashidul; Petri, William A.

2009-01-01

325

Giardia Infection Prevention and Control  

Science.gov (United States)

... please visit this page: About CDC.gov . Parasites - Giardia Parasites Home Share Compartir Prevention & Control On This ... Clean up after ill pets and people. See Giardia and Pets for information on minimizing your exposure ...

326

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

Energy Technology Data Exchange (ETDEWEB)

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 of 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.

Biswas, Shyamasri; Buhrman, Greg; Gagnon, Keith; Mattos, Carla; Brown, II, Bernard A.; Maxwell, E. Stuart (NCSU); (UTSMC)

2012-07-11

327

Hospital-based surveillance of enteric parasites in Kolkata  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Diarrhoea is the second leading cause of illness and death in developing countries and the second commonest cause of death due to infectious diseases among children under five in such countries. Parasites, as well as bacterial and viral pathogens, are important causes of diarrhoea. However, parasitic infections are sometimes overlooked, leading after a period of time to an uncertain aetiology. In this paper we report the prevalence of Giardia lamblia, Entamoeba histolytica and Cryptosporidium sp. in and around Kolkata. Findings A hospital-based laboratory surveillance study was conducted among the patients admitted between November 2007 and October 2008 to the Infectious Diseases (ID Hospital (Population = 1103 with diarrhoeal complaints. Of the 1103 samples collected, 147 were positive for Giardia lamblia, 84 for Cryptosporidium sp. and 51 for Entamoeba histolytica. For all these parasites there was a high rate of mixed infection with common enteric viruses and bacteria such as Rotavirus, Vibrio cholerae and Shigella sp. There were also cases of co-infection with all other diarrheogenic pathogens. The age group ? 5 years had the highest prevalence of parasites whereas the age group >5 – 10 years was predominantly infected with Giardia lamblia (p =10 – 20 years could also be considered at risk for G. lamblia (p = 0.009; OR = 2.231; 95% CI = 1.223 – 4.067. Month-wise occurrence data showed an endemic presence of G. lamblia whereas Cryptosporidium sp. and E. histolytica occurred sporadically. The GIS study revealed that parasites were more prevalent in areas such as Tangra, Tiljala and Rajarhat, which are mainly slum areas. Because most of the population surveyed was in the lower income group, consumption of contaminated water and food could be the major underlying cause of parasitic infestations. Conclusion This study provides important information on the occurrence and distribution of three important intestinal parasites and indicates their diarrheogenic capacity in Kolkata and surrounding areas.

Ghosh Mrinmoy

2009-06-01

328

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

Science.gov (United States)

SUMMARY 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. PMID:24125434

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

2014-08-01

329

OBSERVATION ON THE INTESTINAL PARASITIC INFECTIONS  

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Full Text Available During 1980-82, a total number of 4143 stool samples, from 2332 males and 1811 females, referred to the Central Laboratory of the School of Public Health, were examined for intestinal parasites. All the specimens were examined for intestinal parasites. All the specimens were examined by formol-ether concentration and wet-mount (ringer solution techniques. The main prevalent pathogenic parasites were Entamoeba histolytica (8.7%, Giardia lamblia (16.1%, and Hymenolepis nana (3.2%. The overall infection rate with protozoa, metazoan and both were 45%, 18.3% and 53.8% respectively.

M.Rezaeian

1986-08-01

330

Gene Regulation in Giardia lambia Involves a Putative MicroRNA Derived from a Small Nucleolar RNA  

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Two core microRNA (miRNA) pathway proteins, Dicer and Argonaute, are found in Giardia lamblia, a deeply branching parasitic protozoan. There are, however, no apparent homologues of Drosha or Exportin5 in the genome. Here, we report a 26 nucleotide (nt) RNA derived from a 106 nt Box C/D snoRNA, GlsR2. This small RNA, designated miR5, localizes to the 3? end of GlsR2 and has a 75 nt hairpin precursor. GlsR2 is processed by the Dicer from Giardia (GlDcr) and generated miR5. Immunoprecipitation...

Li, Wei; Saraiya, Ashesh A.; Wang, Ching C.

2011-01-01

331

GASTROINTESTINAL PARASITES OF SCHOOL CHILDREN IN BENIN CITY, NIGERIA  

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Examination of faecal samples of 6,430 school children aged between 2 and 20 years, for gastrointestinal parasites using sedimentation and Kato smear techniques was carried out in Benin City, Nigeria between January 1997 and December 1998. Four thousand two hundred and thirty six (65.8%) were infected. Three species of protozoa and 8 species of helminths were recorded as follows: Entamoeba histolytica (6%), Entomoeba coli (4.8%), Giardia lamblia (5.2%), Schistosoma mansoni (2.4%), Fasciola gi...

Ce, Okaka; Ao, Awharitoma; Jn, Okonji

2000-01-01

332

Evaluation of a new monoclonal antibody combination reagent for direct fluorescence detection of Giardia cysts and Cryptosporidium oocysts in human fecal specimens.  

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Giardia lamblia and Cryptosporidium parvum can cause severe symptoms in humans, particularly in the immunologically compromised. Monoclonal antibody reagents offer increased sensitivity and an excellent alternative to conventional staining methods. These reagents are helpful when screening large numbers of patients or those with minimal symptoms. Problems of false-positive and false-negative results with routine staining methods for stool parasites can be eliminated with monoclonal antibody r...

Garcia, L. S.; Shum, A. C.; Bruckner, D. A.

1992-01-01

333

INACTIVATION OF 'GIARDIA' CYSTS BY CHLORINE  

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This study was undertaken to determine the viability of Giardia lamblia cysts shed from an asymptomatic carrier and to correlate the chlorine resistance of these cysts with those from a symptomatic carrier and another Giardia species, G. muris, which is infective for mice....

334

Identification of chitin as a structural component of Giardia cysts.  

Science.gov (United States)

The intestinal parasite Giardia lamblia is a significant cause of diarrheal disease, which is perpetuated by the infective cyst form of the parasite. Although a rational approach to the control of giardiasis would be to inhibit cyst formation, nothing is known of the chemical composition of the cyst wall or of its biosynthesis. In these studies, we have shown that chitin is a major structural component of G. lamblia and G. muris cyst walls. This conclusion is based on the finding that chitinase specifically destroys the cyst wall, as revealed by electron microscopy. The presence of chitin was also shown directly by lectin binding studies. Of 12 lectins with diverse carbohydrate recognition specificity, only the N-acetylglucosamine-specific lectins wheat germ agglutinin, succinylated wheat germ agglutinin, and tomato lectin bound to cyst walls, as shown by fluorescence microscopy and cytochemistry. Wheat germ agglutinin binding was completely abolished by treatment of the cysts with purified chitinase. This effect was specific since it could be prevented by incubating the enzyme with chitin before treatment of the cysts. Treatment of cysts with N-acetyl-beta-glucosaminidase partially inhibited wheat germ agglutinin binding, whereas other glycosidases and proteases had no effect. These findings indicate that chitin is a major structural component of Giardia cyst walls and raise the possibility that inhibitors of chitin synthesis may be of use in preventing encystation and thus controlling spread of the disease. PMID:4030095

Ward, H D; Alroy, J; Lev, B I; Keusch, G T; Pereira, M E

1985-09-01

335

Parasitas intestinais em centros de educação infantil municipal de Lages, SC, Brasil Intestinal parasites in nursey schools of Lages, southern Brazil  

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Full Text Available Infecção por enteroparasitas foi avaliada em 200 crianças em idade escolar, residentes em Lages. A prevalência geral entre helmintos e protozoários foi de 70,5% com 61,4% no sexo masculino e 74,5% no feminino. Os parasitos mais prevalentes foram Ascaris lumbricoides (35%, Giardia lamblia (14% e Trichuris trichiura (13%.Two hundred chinldren from nursery schools in Lages, southern Brazil, were associated as to parasitic ibfections. The overall prevalence of helminths and protozoa was 70.5%, affecting 61.4% of male and 74.5% of female children. The most prevalent parasites were Ascaris lumbricoides (35%, Giardia lambia (14% e Trichuris trichiura (13%.

Rosiléia Marinho de Quadros

2004-10-01

336

Antigenic conservation and variation in Giardia cysts from various vertebrate hosts.  

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Monoclonal antibodies produced against Giardia muris cysts reacted in indirect immunofluorescence with homologous cysts and cysts from a Giardia-infected wild Norway rat but did not cross-react with Giardia lamblia cysts of human, dog, or beaver sources. Another monoclonal antibody raised against Giardia simoni cysts from the Norway rat reacted with homologous cysts (rat) and cross-reacted with cysts from a cow. The demonstration of antigenic differences at the cyst surfaces of Giardia organi...

Riley, E. T.; Stibbs, H. H.

1989-01-01

337

Diarrea crónica refractaria y malabsorción secundaria a hipogammaglobulinemia común variable, infestación crónica por giardia lamblia y gastrectomía total por adenocarcinoma gástrico: un manejo nutricional complejo / Chonic diarrhea and malabsorption due to common variable immunodeficiency, gastrectomy and giardiasis infection: a difficult nutritional management  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish El adenocarcinoma gástrico es una de las causas más frecuentes de mortalidad en el mundo, siendo la cirugía el único tratamiento potencialmente curativo, aunque los efectos adversos digestivos y nutricionales son frecuentes y abundantes. La hipogammaglobulinemia variable común es causa de frecuentes [...] manifestaciones digestivas, derivándose las más importantes en diarrea crónica causada por giardiasis, hiperplasia nodular linfoide o atrofia vellosa, siendo frecuente la malabsorción y la desnutrición. Los déficits nutricionales secundarios a la malabsorción (postgastrectomía y asociada a la atrofia vellosa y la giardiasis por hipogammaglobulinemia variable común) son asimismo frecuentes. Presentamos el caso de un paciente gastrectomizado por adenocarcinoma gástrico y con hipogammaglobulinemia variable común e infestación crónica por giardiasis que presenta una importante diarrea crónica refractaria a tratamiento y malabsorción. Abstract in english 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 chro [...] nic 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.

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

338

INTESTINAL PARASITES IN SEMBALUN LAWANG, LOMBOK  

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Full Text Available Survey tinja telah dilakukan diantara penduduk di Kampung Sembalun Lawang, Distrik Aikinal, Lombok Timur, pada bulan Agustus 1973 untuk mengetahui angka parasit usus dan demam keong di daerah tersebut. Dari 146 penduduk yang diperiksa tinjanya ditemukan 99 persen mengandung sekurang-kurangnya satu jenis parasit usus, 85 persen dengan dua jenis atau lebih dan 40 persen dengan tiga jenis atau lebih. Tidak ditemukan bibit penyakit demam keong diantara penduduk didaerah ini. Angka infeksi dari parasit usus tersebut masing-masing adalah Ascaris lumbricoides 96 persen, Trichuris trichiura 84 persen, cacing tambang 25 persen, Entamocba coli 18 persen, Enterobius vermicularis 10 persen, lodamoeba butsehlii 3 persen, Entamoeba histolytica 1 persen dan Giardia lamblia 1 persen. Pada umumnya tidak banyak perbedaan angka infeksi dari parasit usus ini diantara golongan umur dan kelamin kecuali untuk cacing tambang dimana infeksi pada golongan laki-laki lebih banyak dari pada golongan perempuan.

Arbain Joesoef

2012-09-01

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Prevalencia de Giardiasis y Parásitos Intestinales en Preescolares de Hogares atendidos en un programa estatal en Armenia, Colombia Prevalence of giardiasis and intestinal parasites in pre-school children from homes being attended as part of a state programme in Armenia, Colombia  

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Full Text Available Objetivo El propósito de este estudio es el de obtener datos sobre la giardiasis y el parasitismo intestinal en una muestra significativa de los niños en edades pre-escolares de los hogares de madres comunitarias del Instituto Colombiano de Bienestar Familiar (ICBF. Materiales y Métodos Se recolectó un seriado de tres muestras de heces en 328 niños, con previo consentimiento del tutor legal. Se le realizó el análisis de laboratorio por examen directo microscópico y macroscópico utilizando Lugol al 1 %, solución salina al 0,83 %, solución salina-eosina, Kato Katz y formol-éter o metodo de concentración de Ritchie (prueba comprobatoria. Las muestras positivas se conservaron en formol salino. Resultados Los parásitos con potencial patógeno tuvieron las siguientes prevalencias: Ascaris lumbricoides 2,4 %, Hymenolepsis nana 0,6 %, Trichuris trichura 2,1 %, Blastocystis hominis 6,1 % y Giardia lamblia 13 %. Conclusiones Este estudio muestra la baja frecuencia de los helmintos con respecto a los protozoos, por lo tanto estrategias de desparasitación masiva con dosis únicas de Albendazol no tienen utilidad. Se recomienda la vigilancia periódica de parásitos por exámenes en estos niños. Se confirma que el parásito patógeno mas prevalente es Giardia lamblia en los niños de las guarderias infantiles del ICBF. La prevalencia de Giardia no se relacionó de manera estadisticamente significativa con el estado nutricional de los niños de las guarderias del ICBF. La mayoria de niños infectados por Giardia son asintomáticos.Objective Determining the prevalence of giardiasis and intestinal parasitism in pre-school children from the Instituto Colombiano de Bienestar Familiar (ICBF. Material and Methods Three serial faecal samples were collected from 328 children following informed consent from their legal guardians. Microscopic and macroscopic tests were made using 1% Lugol, 0,83 % saline solution, saline-eosin solution and Kato Katz and Ritchie’s test as a confirming test. Positive samples were preserved in saline formol solution. Results Pathogen parasites had the following prevalence frequencies: 2,4 % for Ascaris lumbricoides, 0,6 % for Hymenolepsis nana, 2,1 % for Trichuris trichura, 6,1 % for Blastocystis hominis and 13 % for Giardia lamblia. Conclusions The results of this work showed low helminth frequency compared to that for protozoa; control strategies using single doses of Albendazol are therefore not useful. The most prevalent pathogen parasite was Giardia lamblia in children from the ICBF in Armenia. Periodic surveillance of parasites in children is thereby recommended. The prevalence of Giardia lamblia was not statistically related to the children’s nutritional state. Most Giardia-infected children were asymptomatic.

Jorge M Giraldo-Gómez

340

Prevalencia de Giardiasis y Parásitos Intestinales en Preescolares de Hogares atendidos en un programa estatal en Armenia, Colombia / Prevalence of giardiasis and intestinal parasites in pre-school children from homes being attended as part of a state programme in Armenia, Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Objetivo El propósito de este estudio es el de obtener datos sobre la giardiasis y el parasitismo intestinal en una muestra significativa de los niños en edades pre-escolares de los hogares de madres comunitarias del Instituto Colombiano de Bienestar Familiar (ICBF). Materiales y Métodos Se recolect [...] ó un seriado de tres muestras de heces en 328 niños, con previo consentimiento del tutor legal. Se le realizó el análisis de laboratorio por examen directo microscópico y macroscópico utilizando Lugol al 1 %, solución salina al 0,83 %, solución salina-eosina, Kato Katz y formol-éter o metodo de concentración de Ritchie (prueba comprobatoria). Las muestras positivas se conservaron en formol salino. Resultados Los parásitos con potencial patógeno tuvieron las siguientes prevalencias: Ascaris lumbricoides 2,4 %, Hymenolepsis nana 0,6 %, Trichuris trichura 2,1 %, Blastocystis hominis 6,1 % y Giardia lamblia 13 %. Conclusiones Este estudio muestra la baja frecuencia de los helmintos con respecto a los protozoos, por lo tanto estrategias de desparasitación masiva con dosis únicas de Albendazol no tienen utilidad. Se recomienda la vigilancia periódica de parásitos por exámenes en estos niños. Se confirma que el parásito patógeno mas prevalente es Giardia lamblia en los niños de las guarderias infantiles del ICBF. La prevalencia de Giardia no se relacionó de manera estadisticamente significativa con el estado nutricional de los niños de las guarderias del ICBF. La mayoria de niños infectados por Giardia son asintomáticos. Abstract in english Objective Determining the prevalence of giardiasis and intestinal parasitism in pre-school children from the Instituto Colombiano de Bienestar Familiar (ICBF). Material and Methods Three serial faecal samples were collected from 328 children following informed consent from their legal guardians. Mic [...] roscopic and macroscopic tests were made using 1% Lugol, 0,83 % saline solution, saline-eosin solution and Kato Katz and Ritchie’s test as a confirming test. Positive samples were preserved in saline formol solution. Results Pathogen parasites had the following prevalence frequencies: 2,4 % for Ascaris lumbricoides, 0,6 % for Hymenolepsis nana, 2,1 % for Trichuris trichura, 6,1 % for Blastocystis hominis and 13 % for Giardia lamblia. Conclusions The results of this work showed low helminth frequency compared to that for protozoa; control strategies using single doses of Albendazol are therefore not useful. The most prevalent pathogen parasite was Giardia lamblia in children from the ICBF in Armenia. Periodic surveillance of parasites in children is thereby recommended. The prevalence of Giardia lamblia was not statistically related to the children’s nutritional state. Most Giardia-infected children were asymptomatic.

Jorge M, Giraldo-Gómez; Fabiana, Lora; Luz H, Henao; Shirley, Mejía; Jorge E, Gómez-Marín.

2005-11-17

 
 
 
 
341

Prevalencia de giardiasis y parásitos intestinales en preescolares de hogares atendidos en un programa estatal en Armenia, Colombia / Prevalence of giardiasis and intestinal parasites in pre-school children from homes being attended as part of a state programme in Armenia, Colombia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Public Health | Language: Spanish Abstract in spanish OBJETIVO: El propósito de este estudio es el de obtener datos sobre la giardiasis y el parasitismo intestinal en una muestra significativa de los niños en edades pre-escolares de los hogares de madres comunitarias del Instituto Colombiano de Bienestar Familiar (ICBF). MATERIALES Y MÉTODOS: Se recole [...] ctó un seriado de tres muestras de heces en 328 niños, con previo consentimiento del tutor legal. Se le realizó el análisis de laboratorio por examen directo microscópico y macroscópico utilizando Lugol al 1 %, solución salina al 0,83 %, solución salina-eosina, Kato Katz y formol-éter o metodo de concentración de Ritchie (prueba comprobatoria). Las muestras positivas se conservaron en formol salino. RESULTADOS: Los parásitos con potencial patógeno tuvieron las siguientes prevalencias: Ascaris lumbricoides 2,4 %, Hymenolepsis nana 0,6 %, Trichuris trichura 2,1 %, Blastocystis hominis 6,1 % y Giardia lamblia 13 %. CONCLUSIONES: Este estudio muestra la baja frecuencia de los helmintos con respecto a los protozoos, por lo tanto estrategias de desparasitación masiva con dosis únicas de Albendazol no tienen utilidad. Se recomienda la vigilancia periódica de parásitos por exámenes en estos niños. Se confirma que el parásito patógeno mas prevalente es Giardia lamblia en los niños de las guarderias infantiles del ICBF. La prevalencia de Giardia no se relacionó de manera estadisticamente significativa con el estado nutricional de los niños de las guarderias del ICBF. La mayoria de niños infectados por Giardia son asintomáticos. Abstract in english OBJECTIVE: Determining the prevalence of giardiasis and intestinal parasitism in pre-school children from the Instituto Colombiano de Bienestar Familiar (ICBF). MATERIAL AND METHODS: Three serial faecal samples were collected from 328 children following informed consent from their legal guardians. M [...] icroscopic and macroscopic tests were made using 1% Lugol, 0,83 % saline solution, saline-eosin solution and Kato Katz and Ritchie's test as a confirming test. Positive samples were preserved in saline formol solution. RESULTS: Pathogen parasites had the following prevalence frequencies: 2,4 % for Ascaris lumbricoides, 0,6 % for Hymenolepsis nana, 2,1 % for Trichuris trichura, 6,1 % for Blastocystis hominis and 13 % for Giardia lamblia. CONCLUSIONS: The results of this work showed low helminth frequency compared to that for protozoa; control strategies using single doses of Albendazol are therefore not useful. The most prevalent pathogen parasite was Giardia lamblia in children from the ICBF in Armenia. Periodic surveillance of parasites in children is thereby recommended. The prevalence of Giardia lamblia was not statistically related to the children's nutritional state. Most Giardia-infected children were asymptomatic.

Jorge M., Giraldo-Gómez; Fabiana, Lora; Luz H., Henao; Shirley, Mejía; Jorge E., Gómez-Marín.

342

Parasitic Contamination of Raw Vegetables in Shahroud, Semnan  

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

Saeid Nazemi

2012-08-01

343

The Antimicrobial Effect of Methanol Extracts of Eucalyptus, Satureia Hortensis and Heracleum Glabrescens on Giardia Cysts  

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Full Text Available Background and objectives: Giardiasis is a parasitic infection of smallintestine, with a worldwide distribution and the prevalence of Giardia indifferent parts of the world varies between 1 to 25%. Plants have the vastrange of antimicrobial and antifungal activity that can be identified asalternative treatments for bacterial and parasitic pathogens, the same asGiardia. In this study, the methanol extracts of eucalyptus plants, Satureiahortensis and Heracleum glabrescens, on Giardia cysts were studied in vitro.Material and Methods: The cysts were isolated from the feces using amodified Bingham. After counting by Hemusytumetr, they were placed nearby 200 mg / ml, 100 mg / ml and 10 mg / ml of the extracts prepared byDMSO for 30 and 60 minutes. Then, the number of dead and live cysts wascounted under a microscope.Results: the fatality effect of the extracts in 60 minutes is higher than thoseof 30 minutes. The methanol extracts of Satureia hortensis, Eucalyptus andHeracleum glabrescens with the dilution of 200 mg/ml in 60 mins have thefatality effect of 84/3%, 63/3% and 44%, respectively. The highestfatality(84.3% on Giardia cysts is related to Satureia hortensis with thedilution of 200 mg/ml in 60 mins and the Lowest(27% is related toHeracleum glabrescens with the dilution of 10 mg/ml in 30-minute period.The significant relationship between the plant type and the fatality ofmethanol extracts is observed.Conclusion: the methanol extracts of Eucalyptus, Heracleum glabrescensand especially Satureia hortensis have anti-parasitic effects in the laboratoryconditions. Thus, they can be used in the future, instead of the chemicalantiparasitic drugs.Key words: Antibacterial Giardia lamblia cysts, Eucalyptus, Satureiahortensis, Heracleum glabrescens, Tonekabon

Safarnejad Tameshkel, F.

2012-01-01

344

Detection of Cryptosporidium spp and other intestinal parasites in children with acute diarrhea and severe dehydration in Rio de Janeiro Detecção de Cryptosporidium spp e outros parasitas intestinais em crianças com diarréia aguda e desidratação grave no Rio de Janeiro  

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The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3%) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7%) samples examined via the direct or Ritchie me...

Filipe Anibal Carvalho-Costa; Alessandra Queiroga Gonçalves; Sandra Laranjeira Lassance; Carla Pontes de Albuquerque; José Paulo Gagliardi Leite; Márcio Neves Bóia

2007-01-01

345

Intestinal Parasites in Children with Lymphohematopoietic Malignancy in Iran, Mashhad  

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Full Text Available Background: Intestinal parasitic disease can cause serious complications for Immunosuppressed patients.Objectives: This study determines the prevalence of intestinal parasites in children, with lymphohematopoietic malignancy in Mashhad, Iran.Patients and Methods: In this cross-sectional study stool samples were collected from 89 children (53 boys, 36 girls with lymphohematopoitic malignancies under chemotherapy, between the age of 1 and 18 years (mean age 7.5 years. Three fresh stool samples taken for three consecutive days were examined by direct smear, formalin-ether method, trichrome staining and ELISA test for Giardia lamblia coproantigens.Results: In this study 35.9% of our patients had parasitic infections and the following parasites were identified; G. lamblia (the most prevalent parasite in children 16 (18%, Entamoeba coli 6 (6.7% Blastocystis hominis 5 (5.6% Iodamoeba butschlii 2 (2.2%. Chilomastics mesnili 1 (1.1%, Hymenolepis nana 1 (1.1% and Enterobius vermicularis 1 (1.1%.Conclusions: With regards to the high incidence of gasterointestinal parasitic diseases and also because of asymptomatic cases of giardiasis, we recommend evaluation of pediatric patients with malignant lymphohematopoitic disease by at least two different diagnostic methods and three rounds of stool examination in order to prevent possible life threatening outcomes. Coproparasitoscopic study for oncologic patients should be performed and anti-parasitic treatment provided before starting chemotherapy to prevent disseminated parasitic infections. The coproantigen-ELISA is especially advantageous in situations where only a single stool sample can be examined.

Nona Zabolinejad

2013-08-01

346

EFFECT OF HALOGENS ON 'GIARDIA' CYST VIABILITY  

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The objective of this research was to determine the effect of chlorine and other disinfecting agents on Giardia lamblia cyst viability. The agents studied included free residual chlorine and six different methods recommended for emergency disinfection of small quantities of water...

347

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

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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...

348

Parasitic prevalence in a suburban school of famaillá, tucumán, Argentina.  

Science.gov (United States)

Prevalence of intestinal parasites was investigated in rural primary school children in Famaillá city, Tucumán province, Argentina. Stool specimens from 149 school children were collected. The prevalence rate of intestinal parasite infections was 86.6%. No significant differences were observed in the distribution by age or by sex. Blastocystis hominis was the most commonly found protozoan parasite (54.4%), followed by Entamoeba coli (35.6%), Giardia lamblia (24.8%), and others (16.7%). Enterobius vermicularis was the most prevalent intestinal helminth (27.5%), followed by Ascaris lumbricoides (20.8%), Trichuris trichiura (12.8%), and others (5.4%). Most of the patients had polyparasitism (62.4%), and protozoan infections prevailed over helminthic infections. These results show high rates of parasitism in the school children of Famaillá, which would be associated with socioeconomic factors and poor environmental sanitation conditions in this area. PMID:23724325

Dib, Julián; Oquilla, Juana; Lazarte, Silvia G; Gonzalez, Silvia N

2012-01-01

349

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

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Giardia duodenalis is one of the most prevalent enteroparasites in children. This parasite produces several clinical manifestations. The aim of this study was to determine the prevalence of genotypes of G. duodenalis causing infection in a region of southeastern Mexico. G. duodenalis cysts were isolated (33/429) from stool samples of children and molecular genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, targeting the triosephosphate isomerase ( tpi ) and glutamate dehydrogenase ( gdh ) genes. The tpi gene was amplified in all of the cyst samples, either for assemblage A (27 samples) or assemblage B (6 samples). RFLP analysis classified the 27 tpi -A amplicons in assemblage A, subgenotype I. Samples classified as assemblage B were further analysed using PCR-RFLP of the gdh gene and identified as assemblage B, subgenotype III. To our knowledge, this is the first report of assemblage B of G. duodenalis in human clinical samples from Mexico. PMID:24676655

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

2014-06-01

350

Longitudinal studies of Giardia contamination in two community drinking water supplies: cyst levels, parasite viability, and health impact.  

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Giardia cyst concentrations were determined in an inventory of 153 raw and 91 chlorinated drinking water samples collected at 86 sites from throughout the western Canadian province of British Columbia. Sixty-four percent of raw water samples were cyst positive (69% of sites). Cyst concentrations were lower in chlorinated than in raw water. The viability of cysts in drinking water samples assessed by infectivity in Mongolian gerbils (Meriones unguiculatus) was decreased in chlorinated water. T...

Isaac-renton, J.; Moorehead, W.; Ross, A.

1996-01-01

351

Prevalence and seasonal fluctuations of intestinal parasitic infections in the Nablus area, West Bank of Jordan.  

Science.gov (United States)

A total of 22,970 stool specimens collected from patients attending the Central Medical Laboratory in the city of Nablus in the period of 1981-1986 were examined for intestinal parasites. Of these 7412 (32.3%) were positive. Entamoeba histolytica (22.9%), Giardia lamblia (7.3%), and Ascaris lumbricoides (5.7%) were the most prevalent intestinal parasites found. Other intestinal parasites present included Hymenolepis nana, Trichomonas hominis, Trichuris trichiura, Taenia saginata, Enterobius vermicularis and Strongyloides stercoralis. Seasonal occurrence of intestinal parasites in the West Bank of Jordan was also studied in the period January 1981-August 1987. Lower prevalence rates of intestinal parasites generally occurred during winter and early spring. Peak incidence occurred during summer and early autumn. The reasons for these seasonal variations are discussed. PMID:2596904

Ali-Shtayeh, M S; Hamdan, A H; Shaheen, S F; Abu-Zeid, I; Faidy, Y R

1989-02-01

352

Anti-Giardia activity of phenolic-rich essential oils: effects of Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris, and Lippia graveolens on trophozoites growth, viability, adherence, and ultrastructure.  

Science.gov (United States)

The present work evaluates the anti-Giardia activity of phenolic-rich essential oils obtained from Thymbra capitata, Origanum virens, Thymus zygis subsp. sylvestris chemotype thymol, and Lippia graveolens aromatic plants. The effects were evaluated on parasite growth, cell viability adherence, and morphology. The tested essential oils inhibited the growth of Giardia lamblia. T. capitata essential oil is the most active followed by O. virens, T. zygis subsp. sylvestris, and L. graveolens oils. The tested essential oils at IC50 (71-257) microg/ml inhibited parasite adherence (p incubation and were able to kill almost 50% of the parasites population in a time-dependent manner. The main ultrastructural alterations promoted by essential oils were deformations in typical trophozoite appearance, often roundly shape, irregular dorsal and ventral surface, presence of membrane blebs, electrodense precipitates in cytoplasm and nuclei, and internalization of flagella and ventral disc. Our data suggest that essential oils induced cell death probably by processes associated to the loss of osmoregulation caused by plasmatic membrane alterations. Experiments revealed that the essential oils did not present cytotoxic effects in mammalian cells. In conclusion, T. capitata, O. virens, T. zygis subsp. sylvestris chemotype thymol, and L. graveolens essential oils have antigiardial activity in vitro and seem to have potential for the treatment of the parasitic disease caused by the protozoan G. lamblia. PMID:20217133

Machado, Marisa; Dinis, Augusto M; Salgueiro, Ligia; Cavaleiro, Carlos; Custódio, José B A; Sousa, Maria do Céu

2010-04-01

353

PREVALENCE OF INTESTINAL PARASITES IN SLUM AREAS OF SOUTHERN DELHI  

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Full Text Available A retrospective study was conducted during the period of 1st July 2010 to 30th June 2011 in the department of microbiology of HAH centenary Hospital, Hamdard Institute of Medical Sciences, New Delhi. A total of 2907 Stool samples send to the microbiology department from indoor and outdoor patients with gastrointestinal symptoms with or without anemia were analyzed. The patients were mostly from low socio economic strata of Sangam Vihar. 759 samples were positive for parasitic infections. The most common intestinal parasites were found to be E. histolytica (20.22%, followed by Giardia lamblia (2.68% and Ascaris lubricoides (1.4%. Ova of Hookworm and larvae of Strongyloides stercoralis was found 6 times each. Other common parasitic isolates were Taenia species (0.1%, H. nana (0.48%, Trichuris trichura (0.1% and Trichomonas hominis 17 (0.58%. The study emphasizes on better drinking water and sanitation requirement for the target population.

Dudeja M., Nandy S., Das A.K., Alam S. and Tiwari R.

2012-09-01

354

Propidium iodide as an indicator of Giardia cyst viability.  

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The use of propidium iodide, whose uptake indicates cell death or damage, was investigated to assess the viability of heat-inactivated and chemically inactivated Giardia muris cysts. This was done by comparing propidium iodide staining with excystation. We first determined that propidium iodide could be used with an immunofluorescence detection procedure by showing that the percentages of Giardia lamblia cysts stained with this dye before and after subjecting them to a fluorescence detection ...

Sauch, J. F.; Flanigan, D.; Galvin, M. L.; Berman, D.; Jakubowski, W.

1991-01-01

355

Intestinal parasites in ecotourism region of the state of Paraná, Brazil  

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To determine the indices of prevalence of intestinal parasites and commensals in the residents of ecotourism region of Paraná State, a retrospective study was conducte, from January/2003 to December/2004 on 3,764 fecal parasitological examinations performed by a private laboratory of Ubiratã using the Baermann-Moraes, water-sedimentation and Willis methods. Among the individuals aged eight months to 89 years, 522 (13.9%) cases were positive. Giardia lamblia (175/522; 24.2%) was the most pre...

Dina Lúcia Morais Falavigna; Amanda Andrea de Almeida; Renata Sayuri Iwazaki; Silvana Marques Araújo

2008-01-01

356

Intestinal Parasites Infection among Immunocompromised Patients in Riyadh, Saudi Arabia  

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Full Text Available This study was conducted to determine the prevalence of intestinal parasites among immunocompromised patients in Riyadh, Saudi Arabia. Fecal samples were collected from 136 immunocompromised patients (52 females and 84 males, aged 2 to 69 years. Specimens were fixed with 10% formalin for 30 min (2-3 g fecal-1 and then concentrated by a formalin-ether sedimentation technique. Samples were examined as wet saline mounts and in iodine preparation for detection of protozoan oocysts, cysts, helminthic eggs and larvae. Permanent stained smears were performed for intestinal coccidian parasites by the modified Ziehl-Neelsen technique and the modified trichrome stain. Intestinal parasites were detected in 54 (39.7% most of them (25.7% were with diarrhea. More specifically the following parasites were detected Cryptosporidium parvum 11(8.1%, Giardia lamblia 9 (6.6%, Cyclospora cayetanensis 8 (5.9%, Blastocystis hominis 7 (5.2%, Entamoeba histolytica 7 (5.2%, Entamoeba coli 5 (3.7%, Strongyloides stercoralis 3 (2.2%, Ascaris lumbricoides 1 (0.7%, Hymenolepis nana 1 (0.7%, Dicrocoelium dendriticum 1 (0.7% and Hook worm 1 (0.7%. The most common parasite associated with diarrhea in patients, was C. parvum (p<0.001, followed by G. lamblia, C. cayetanensis and E. histolytica. However, differences between different age groups were statistically non-significant. Similarly, no significant difference in the infection rate were found between male and female patients.

Wafa A.I. Al-Megrin

2010-01-01

357

Identification of scaffold/Matrix Attachment (S/MAR) like DNA element from the gastrointestinal protozoan parasite Giardia lamblia  

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Abstract Background Chromatin in the nucleus of all eukaryotes is organized into a system of loops and domains. These loops remain fastened at their bases to the fundamental framework of the nucleus, the matrix or the scaffold. The DNA sequences which anchor the bases of the chromatin loops to the matrix are known as Scaffold/Matrix Attachment Regions or S/MARs. Though S/MARs have been studied in yeast and higher eukaryotes and they have been found to be associated with gene ...

Padmaja Sushma S; Lakshmanan Jagannathan; Gupta Ravi; Banerjee Santanu; Gautam Pennathur; Banerjee Sulagna

2010-01-01

358

Usefulness of an enzyme-linked immunosorbent assay for detection of Giardia antigen in feces.  

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The usefulness of a recently developed enzyme-linked immunosorbent assay which detects Giardia lamblia antigen in feces was determined in experimentally infected humans. Giardia antigen was determined in serially collected fecal specimens from humans inoculated with two Giardia isolates, GS/M and Isr. A total of 277 stools from 18 volunteers were tested, 74 from Isr-inoculated volunteers and 203 from GS/M-inoculated volunteers. None of the five Isr-inoculated volunteers became infected, and n...

Nash, T. E.; Herrington, D. A.; Levine, M. M.

1987-01-01

359

Cryptosporidium and Giardia: new challenges to the water industry  

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The protozoan parasites Cryptosporidium parvum and Giardia intestinalis have emerged as significant waterborne pathogens over the past decades. Many outbreaks of waterborne cryptosporidiosis and giardiasis have been recorded,

1999-01-01

360

DIATOMACEOUS EARTH FILTRATION OF 'GIARDIA' CYSTS AND OTHER SUBSTANCES  

Science.gov (United States)

Pilot-plant tests resulted in virtually 100% removals of Giardia lamblia cysts for both coarse and fine grades of diatomaceous earth over a wide range of conditions. Removals of turbidity and total coliform bacteria were functionally dependent on the grade of diatomaceous earth. ...

 
 
 
 
361

DO AUTOCHTHONOUS BACTERIA AFFECT GIARDIA CYST SURVIVAL IN NATURAL WATERS?  

Science.gov (United States)

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 ...

362

PREVALENCE OF INTESTINAL PARASITES AMONG FOOD HANDLERS IN WESTERN IRAN  

Science.gov (United States)

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

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

2014-01-01

363

Prevalence and clinical features of Dientamoeba fragilis infections in patients suspected to have intestinal parasitic infection.  

Science.gov (United States)

The present study was conducted to determine the prevalence and clinical features of dientamoebiasis in patients presumed to be infected with intestinal parasites. A total of 168 patients were examined for D. fragilis using microscopy (after Wheatley's trichrome staining) and culture (using modified Boeck and Drbohlav's medium). D. fragilis trophozoites were detected in 15 samples (8.9%) examined using trichrome staining and in 50 samples (29.8%) by culture method. Other enteric parasites were common in the study population as 48.8% of patients (82/168) were found harboring intestinal parasites. Blastocystis hominis was the most common, identified in 33.3% (56/168) of the samples. Giardia lamblia was detected in 17.9% (30/168) and E. histolytica/E. dispar in 11.9% (20/168). The symptoms most frequently encountered were diarrhea, abdominal pain and weight loss and fatigue. Diarrhea and abdominal pain were significantly more frequent in patients with dientamoebiasis compared to non pathogenic cases (P fragilis compared to 50% of patients infected with G. lamblia, while abdominal pain was encountered with D. fragilis in 41% compared to 33.3% with G. lamblia. These differences were insignificant (P > 0.05). PMID:17985591

Rayan, Hanan Z E; Ismail, Ola A; El Gayar, Eman K

2007-08-01

364

Frequency of Intestinal Parasites in Tehran  

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Full Text Available "nBackground: For a long time, intestinal parasite infections are among the major problems of public health in Iran. Our aim was epidemiological studies on the frequency of intestinal parasites in patients re­ferred to three hospitals in Tehran during 2007-2008."nMethods: During 2007-2008, by simple random selection, 1000 stool samples were collected from Mi­lad, Hazrat-e-Rasoul and Shahid Fahmideh hospitals in Tehran, Iran. We examined the samples using di­rect smear, formol-ethyl acetate concentration, Agar-plate culture and Ziehl-Neelsen staining tech­nique."nResults: The frequency of intestinal parasites were: Blastocystis hominis 12.8%, Giardia lamblia 2.5%, En­tamoeba coli 4.8%, Iodamoeba butschlli 0.9%, unknown 4 nuclei cysts 0.4%, Endolimax nana 3.2%, Chilomastix mesnili 0.4%, Strongyloides stercoralis 0.1%, Hymenolepis nana 0.2% and Taenia sagi­nata 0.2%. Coccidian parasites were not found. Results show that infection with intestinal parasites does not statistically significant according to sex and age."nConclusion: The intestinal parasites, especially helminthic infections have been decreased during re­cent years.

H Oormazdi

2009-05-01

365

Parasitas intestinais em centros de educação infantil municipal de Lages, SC, Brasil / Intestinal parasites in nursey schools of Lages, southern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Infecção por enteroparasitas foi avaliada em 200 crianças em idade escolar, residentes em Lages. A prevalência geral entre helmintos e protozoários foi de 70,5% com 61,4% no sexo masculino e 74,5% no feminino. Os parasitos mais prevalentes foram Ascaris lumbricoides (35%), Giardia lamblia (14%) e Tr [...] ichuris trichiura (13%). Abstract in english Two hundred chinldren from nursery schools in Lages, southern Brazil, were associated as to parasitic ibfections. The overall prevalence of helminths and protozoa was 70.5%, affecting 61.4% of male and 74.5% of female children. The most prevalent parasites were Ascaris lumbricoides (35%), Giardia la [...] mbia (14%) e Trichuris trichiura (13%).

Quadros, Rosiléia Marinho de; Marques, Sandra; Arruda, Andréia Aparecida Ribeiro; Delfes, Patrícia Simone Wolff Rosa; Medeiros, Íris Aparecida Azevedo.

366

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

Scientific Electronic Library Online (English)

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

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

367

Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Other Intestinal Parasites in Young Children in Lobata Province, Democratic Republic of S?o Tom? and Principe  

Science.gov (United States)

Rare systemic studies concerning prevalence of intestinal parasites in children have been conducted in the second smallest country in Africa, the Democratic Republic of São Tomé and Príncipe. Fecal specimens from 348 children (214 in-hospital attending the Aires de Menezes Hospital and 134 from Agostinho Neto village) in São Tome Island were studied by parasitological and molecular methods. Of the 134 children from Agostinho Neto, 52.2% presented intestinal parasites. 32.1% and 20.2% of these children had monoparasitism and polyparasitism, respectively. Ascaris lumbricoides (27.6%), G. duodenalis (7.5%), T. trichiura (4.5%) and Entamoeba coli (10.5%) were the more frequent species identified in the children of this village. Giardia duodenalis (7.5%) and E. bieneusi (5.2%) were identified by PCR. Nested-PCR targeting G. duodenalis TPI identified Assemblage A (60%) and Assemblage B (40%). The E. bieneusi ITS-based sequence identified genotypes K (57.1%), KIN1 (28.6%) and KIN3 (14.3%). Among the 214 in-hospital children, 29.4% presented intestinal parasites. In 22.4% and 7.0% of the parasitized children, respectively, one or more species were concurrently detected. By microscopy, A. lumbricoides (10.3%) and Trichiuris trichiura (6.5%) were the most prevalent species among these children, and Cryptosporidium was detected by PCR in 8.9% of children. GP60 locus analysis identified 6.5% of C. hominis (subtypes IaA27R3 [35.7%], IaA23R3 [14.3%], IeA11G3T3 [28.6%] and IeA11G3T3R1 [21.4%]) and 2.3% of C. parvum (subtypes IIaA16G2R1 [20.0%], IIaA15G2R1 [20.0%], IIdA26G1 [40.0%] and IIdA21G1a [20.0%]). G. duodenalis and E. bieneusi were identified in 0.5% and 8.9% of the in-hospital children, respectively. G. duodenalis Assemblage B was characterized. The E. bieneusi genotypes K (52.6%), D (26.4%), A (10.5%) and KIN1 (10.5%) were identified. Although further studies are required to clarify the epidemiology of these infectious diseases in this endemic region the significance of the present results highlights that it is crucial to strength surveillance on intestinal pathogens.

Lobo, Maria Luisa; Augusto, Joao; Antunes, Francisco; Ceita, Jose; Xiao, Lihua; Codices, Vera; Matos, Olga

2014-01-01

368

Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and other intestinal parasites in young children in Lobata province, Democratic Republic of São Tomé and Principe.  

Science.gov (United States)

Rare systemic studies concerning prevalence of intestinal parasites in children have been conducted in the second smallest country in Africa, the Democratic Republic of São Tomé and Príncipe. Fecal specimens from 348 children (214 in-hospital attending the Aires de Menezes Hospital and 134 from Agostinho Neto village) in São Tome Island were studied by parasitological and molecular methods. Of the 134 children from Agostinho Neto, 52.2% presented intestinal parasites. 32.1% and 20.2% of these children had monoparasitism and polyparasitism, respectively. Ascaris lumbricoides (27.6%), G. duodenalis (7.5%), T. trichiura (4.5%) and Entamoeba coli (10.5%) were the more frequent species identified in the children of this village. Giardia duodenalis (7.5%) and E. bieneusi (5.2%) were identified by PCR. Nested-PCR targeting G. duodenalis TPI identified Assemblage A (60%) and Assemblage B (40%). The E. bieneusi ITS-based sequence identified genotypes K (57.1%), KIN1 (28.6%) and KIN3 (14.3%). Among the 214 in-hospital children, 29.4% presented intestinal parasites. In 22.4% and 7.0% of the parasitized children, respectively, one or more species were concurrently detected. By microscopy, A. lumbricoides (10.3%) and Trichiuris trichiura (6.5%) were the most prevalent species among these children, and Cryptosporidium was detected by PCR in 8.9% of children. GP60 locus analysis identified 6.5% of C. hominis (subtypes IaA27R3 [35.7%], IaA23R3 [14.3%], IeA11G3T3 [28.6%] and IeA11G3T3R1 [21.4%]) and 2.3% of C. parvum (subtypes IIaA16G2R1 [20.0%], IIaA15G2R1 [20.0%], IIdA26G1 [40.0%] and IIdA21G1a [20.0%]). G. duodenalis and E. bieneusi were identified in 0.5% and 8.9% of the in-hospital children, respectively. G. duodenalis Assemblage B was characterized. The E. bieneusi genotypes K (52.6%), D (26.4%), A (10.5%) and KIN1 (10.5%) were identified. Although further studies are required to clarify the epidemiology of these infectious diseases in this endemic region the significance of the present results highlights that it is crucial to strength surveillance on intestinal pathogens. PMID:24846205

Lobo, Maria Luísa; Augusto, João; Antunes, Francisco; Ceita, José; Xiao, Lihua; Codices, Vera; Matos, Olga

2014-01-01

369

HUMAN PARASITIC INFECTIONS IN BALI : A REVIEW  

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Full Text Available Parasitic infections in humans in Bali are well documented, especially in the population who lived in rural areas. The most common infections are those of the soil-transmitted helminthiasis which are caused by Ascaris lumbricoides, Trichuris trichiura and hookworm showing prevalence rates of 40 - 95%, 25 - 90% and 20 - 70% respectively. Enterobius vermicularis prevalence rate has been reported to be 18 - 53%. Taenniasis prevalence rate has been documented to be 0.8 - 23% in some villages, where Taenia saginata was found to be more prevalent than Taenia solium, and this might be due to the eating habit of the Balinese people who consumed both pork and beef lawar. Malaria is still found in Bali especially in regions along the coasts of some regencies, although generally the infection rate is low. The prevalence rates of intestinal protozoa such as Giardia lamblia, Entamoeba histolytica, Balantidium coli have been occasionally reported in low percentages.

Putu Sutisna

2012-09-01

370

Parasites and Foodborne Illness  

Science.gov (United States)

... Web Content Viewer (JSR 286) Actions ${title} Loading... Parasites and Foodborne Illness Introduction Giardia duodenalis or intestinalis ... gondii Trichinella spiralis Taenia saginata/Taenia solium (Tapeworms) Parasites may be present in food or in water ...

371

A study of the prevalence of intestinal parasitic infection in HIV positive individuals in Mashhad, Northeast Iran  

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Full Text Available Introduction and objective: Intestinal parasitic infection is an important problem in the Human Immunodeficiency Virus (HIV-infected patients. The aim of this study was to investigate the prevalence of intestinal parasitic infections among HIV+ patients in Mashhad, Iran.Materials and methods: A coproparasitological study was conducted from October 2005 to August 2006 at Emam Reza hospital, Mashhad University of Medical Sciences, Iran. It was carried out on 31 HIV+ patients admitted at the HIV clinic and 20 HIV-negative individuals as control group using direct and formalin-ether sedimentation concentration methods, trichrome and acid-fast staining.Results: Overall prevalence of intestinal parasites among HIV+ population was 67.7% and in control group was 55% without significant difference between the two groups. More specifically, the following parasites were identified in HIV+ group: Giardia lamblia 22.6%, Blastocystis hominis 22.6%, Chilomastics mesnili 22.6%, Entamoeba coli 9.7%, and Entromonas 3.2%. In the control group Entromonas (45%, B. hominis (15%, E. coli (10%, G. lamblia (5%, and Hymenolepis nana (10%. However, the prevalence of G. lamblia, B. hominis and C. mesnili was greater for HIV+ patients (p<0.05. There were statistically significant differences between trichrome staining (28, 54.9% positive for parasites, acid fast methods (6, 11.8%, direct method (7, 13.7% and formalin-ether method (13, 25.5% in detection of parasites in two groups (p< 0.05. Conclusion: Our study shows the importance of testing for intestinal parasites in patients who are HIV-positive, and emphasizes the necessity of increasing awareness among clinicians regarding the occurrence of parasite infections in these patients. Routine examination of stool samples for parasitic infections could significantly benefit the HIV-infected individuals by contributing to reduce morbidity, mortality and improved quality of life.

Fariba Berenji

2010-04-01

372

A Comparative Analysis of Intestinal Parasitic Infections between HIV+/AIDS Patients and Non-HIV Infected Individuals  

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Full Text Available Background: The aim of this study was to verify the occurrence of intestinal parasitic infections in human immunodeficiency virus (HIV/acquired immunodeficiency syndrome (AIDS patients in Iran in comparison with non-HIV individuals. Methods: A total of HIV+/AIDS patients (Group I and 1220 clinically healthy individuals (Group II were submitted to coproparasitological examination from 2003 to 2005. Results: The overall prevalence of intestinal parasites in group I and group II was 11.4% and 11.6%, respectively, without significant difference between two groups. The prevalence of infection for each helminth and pathogenic protozoan, in every group, was as follows: Group I: Blastocystis hominis (6.1%; Giardia lamblia (4.2%; Cryptosporidium spp. (0.9%; Isospora belli (0.26%; Strongyloides stercoralis (0.26%; Hymenolepis nana (0.13%; and Rhabditis axei (0.13%. Group II: Blastocystis hominis (6.5%; Giardia lamblia (4.1%; Strongyloides stercoralis (0.33%; Hymenolepis nana (0.16%; and Trichostrongylus sp. (0.16%. Although the prevalence of infection for extracellular parasites was not statistically different between two groups, however, the infection rates for enteric coccidians including Cryptosporidium spp. and I. belli were significantly higher in patients at AIDS stage than Group II. Conclusion: The results emphasize the needs for especial consideration of enteropathogenic intracellular coccidians in immunocompromised patients.

EB Kia

2007-04-01

373

Prevalence of intestinal parasites among food handlers in Western Iran.  

Science.gov (United States)

Parasitic infection is one of the problems that affect human health, especially in developing countries. In this study, all of the fast food shops, restaurants, and roast meat outlets of Khorramabad (Western Iran) and all the staff employed by them, some 210 people, were selected through a census and their stools were examined for the presence of parasites. The parasitological tests of direct wet-mount, Lugol's iodine staining, formaldehyde-ether sedimentation and Trichrome staining techniques were performed on the samples. The data was analyzed with a chi-square test and logistic regression was selected as the analytical model. The results showed 19 (9%) stool specimens were positive for different intestinal parasites. These intestinal parasites included Giardia lamblia 2.9%, Entamoeba coli 4.3%, Blastocystis sp. 1.4%, and Hymenolepis nana 0.5%. There was a significant difference between the presence of a valid health card, awareness of transmission of intestinal parasites, participation in training courses in environmental health with intestinal parasites (p 0.05). To control parasitic infection in food handlers, several strategies are recommended such as stool examinations every three months, public education, application of health regulations, controlling the validity of health cards and training on parasitic infection transmission. In this regard, the findings of the present study can be used as a basis to develop preventive programs targeting food handlers because the spread of disease via them is a common problem worldwide. PMID:24626411

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

2014-01-01

374

GIARDIASIS EXTRAINTESTINAL: ENTRE REALIDADES Y MITOS / Extra intestinal manifestations of Giardia Infection: Among myth and reality  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Revisar lo publicado sobre las asociaciones entre giardiasis y manifestaciones extraintestinales y, en los casos de las mejor estudiadas, sobre los mecanismos por los que G. lamblia podría ser capaz de producir daños en órganos y tejidos distantes de la superficie intestinal a la que se adhiere. Se [...] revisaron, previa búsqueda en Medline , todos los artículos publicados sobre manifestaciones extraintestinales de la giardiasis, o relacionados con este tema, durante el período 1985-2006. Puntualmente, algunas monografías y reportes de casos fechados con anterioridad al intervalo mencionado también fueron consultados. Muy variadas son las lesiones asociaciadas a giardiasis descritas en la literatura revisada. De todas ellas, la urticaria y el angiedema, la lesión en “sal y pimienta” del epitelio pigmentado de la retina, la glositis y la artritis reactiva son las más rigurosamente demostradas. En relación con las restantes, estudios adicionales, con el empleo de diseños e instrumentación adecuados, deben demostrar hasta qué punto no son un mito. En perspectivas, además de la continuación de las investigaciones que confirmen y expliquen la existencia de las asociaciones citadas, se hace necesario incursionar en la exploración de los conocimientos, percepciones y prácticas de los médicos relacionados con el diagnóstico, tratamiento y control de la giardiasis. Ello es así, sobre todo, si tenemos en cuenta que en nuestra red de salud se ha hecho habitual el diagnóstico de giardiasis a pacientes con lesiones dermatológicas de naturaleza muy variada y causa no conocida, muchas veces sin el hallazgo del protozoo en sus heces o en el fluido duodenal correspondiente. Abstract in english The purpose of this paper is to go through the literature to review what is published in connection with the association among giardia lamblia infection and extra intestinal manifestations of the disease and the mechanisms which intervene in producing such distant lesions taking in consideration the [...] location of the parasite. Of all the lesions associated to the parasite, rash, angioedema, salt and pepper lesions in the pigments epithelium of the retina, glositis and reactive arthritis are the most rigorously long-established. Regarding others, experimental studies must be carried out to ascertain to which point they are a myth or not. In perspective, besides all the tests that are needed to confirmed the quoted associations, it is necessary to explore the knowledge, perception and practice of doctors related to the diagnosis, prevention and control of the giardia infection. In our Health Care System is very common to find a giardia infection diagnosis in the case of a dermatological infection of unknown origin, most of the times without the findings of the parasite in neither faeces nor bile.

Saleh, Ali Almannoni; Deisy, Martín Pupo; Alexis, Monzote López; Luis, Fonte Galindo.

375

Parasitismo intestinal en una población infantil venezolana / Intestinal parasitism in a Venezuelan pediatric population  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se realizó un estudio descriptivo y transversal de 146 niños con parasitismo intestinal, como muestra representativa de los 227 pacientes de 0-14 años, pertenecientes al Sector 8, Parroquia de Cartanal, Estado Miranda, de la República Bolivariana de Venezuela, en el período 2007- 2008, a fin de cara [...] cterizarles según variables de interés. En la serie predominaron el grupo etario de 0 a 4 años, el sexo masculino, la Giardia lamblia como parásito más frecuente, además de la anemia, la diarrea persistente y el síndrome diarreico agudo como complicaciones más comunes. A fin de minimizar este problema, se recomendó incrementar las actividades de educación sanitaria a la población, para así promover hábitos y estilos de vida saludables. Abstract in english A descriptive and cross-sectional study was conducted in 146 children with intestinal parasitism as a representative sample of 227 patients at age 0-14 years, belonging to the Sector 8, Cartanal parish, Miranda State, of the Bolivarian Republic of Venezuela, from 2007 to 2008, in order to characteri [...] ze them according to variates of interest. In the series the age group of 0 to 4 years, male sex and Giardia lamblia as the most frequent parasite predominated, as well as anemia, persistent diarrhea and acute diarrheal syndrome as the most common complications. To resolve this problem, it was recommended to increase health education activities in the population, thus promoting healthy habits and lifestyles

Arencibia Sosa, Heriberto; Lobaina Lafita, José Luis; Terán Guardia, Carlos; Legrá Rodríguez, Rafael; Arencibia Aquino, Aylin.

376

A comparative study of the intestinal parasites prevalent among children living in rural and urban settings in and around Chennai.  

Science.gov (United States)

A comparative analysis of the various intestinal parasites detected among children attending schools was carried out in a rural and urban location in and around Chennai. A total of 324 stool samples were examined by routine microscopy using normal saline and Lugol's iodine preparation as well as by saturated sodium chloride flotation technique. All suspicious samples were subjected to zinc sulphate concentration technique as well as modified Ziehl Neelson stain and Trichrome stains to identify the other uncommon intestinal parasites. Out of 125 specimens tested from the rural location, the overall prevalence of intestinal parasites was 91%. Ascaris lumbricoides was the most common helminthic parasite detected (52.8%) followed by Trichuris trichura (45.6%), Ancylostoma duodenale (37.6%), Strongyloides stercoralis (3.2%) and Hymenolepis nana (1.6%). Giardia lamblia was the most common protozoan parasite detected (16%), followed by Entamoeba histolytica (4%). In contrast under urban settings, out of the 199 stool specimens tested the positivity rate was 33%. Giardia was the most common parasite detected (22.6%) followed by Entamoeba histolytica (10.6%). All other intestinal parasites such as T. trichura (2.01%), H. nana (1.01%) and A. lumbricoides (0.50%) were found to have much lower prevalence in comparison to the rural area tested. Enterobius vermicularis (0.50%) was also detected. Ancylostoma duodenale and Strongyloides stercoralis were not encountered at all in the urban setting studied. PMID:12718339

Fernandez, Maria Carol; Verghese, Susan; Bhuvaneswari, R; Elizabeth, S J; Mathew, T; Anitha, A; Chitra, A K

2002-03-01

377

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

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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 ?g/ml) and eugenol (IC(50)=101 ?g/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. PMID:21272580

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

2011-04-01

378

Zoonotic Parasites of Bobcats around Human Landscapes  

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We analyzed Lynx rufus fecal parasites from California and Colorado, hypothesizing that bobcats shed zoonotic parasites around human landscapes. Giardia duodenalis, Cryptosporidium, Ancylostoma, Uncinaria, and Toxocara cati were shed. Toxoplasma gondii serology demonstrated exposure. Giardia and Cryptosporidium shedding increased near large human populations. Genotyped Giardia may indicate indirect transmission with humans.

Carver, Scott; Scorza, Andrea V.; Bevins, Sarah N.; Riley, Seth P. D.; Crooks, Kevin R.; Vandewoude, Sue; Lappin, Michael R.

2012-01-01

379

Prevalence of gastrointestinal parasites in the Greek population: local people and refugees  

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Full Text Available SUMMARY A total of 455 faecal samples from the Greek population and refugees was examined and 18.02% were found to be infected with one or more species of parasites. The prevalence of infection with intestinal parasites of the Greek (264 population was 11.36% and that of foreigners (191 originating from Europe, Africa and Asia was 27.23%. Found were a protozoan parasites: Blastocystis hominis, Cryptosporidium parvum, Entamoeba coli and Giardia lamblia (found in both groups examined and b metazoan parasites: Enterobius vermicularis, Taenia spp. and Strongyloides stercoralis (in both groups and Ancylostoma duodenale, Ascaris lumbricoides, Trichuris trichiura and Schistosoma mansoni (only in foreigners. Among the parasites found in foreigners only the helminth species A. duodenale and S. mansoni are considered as imported parasites from tropical and subtropical regions to European countries. The use of the multiple logistic regression showed that the odds ratio comparing Greeks to refugees, adjusted for age and gender, was 3.8 for Africans, 3.0 for Europeans and 2.6 for Asians. No correlation was found between age, gender or symptoms (diarrhea or abdominal pain with the presence of parasites. The overall prevalence of infection with parasites was high in both the Greek population and refugees and therefore a screening for parasite infection is recommended for the prevention of further spread of the infections. Key words: parasites, immigrants, Greece

M.G. Papazahariadou, E.G. Papadopoulos S.E. Frydas, Ch. Mavrovouniotis,T.C. Constantinidis, K. Antoniadou-Sotiriadou,

2007-03-01

380

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

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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 show...

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

1998-01-01

 
 
 
 
381

Evaluation of the EasyScreen™ enteric parasite detection kit for the detection of Blastocystis spp., Cryptosporidium spp., Dientamoeba fragilis, Entamoeba complex, and Giardia intestinalis from clinical stool samples.  

Science.gov (United States)

The aim of this study was to evaluate the EasyScreen™ Enteric Parasite Detection Kit (Genetic Signatures, Sydney, Australia) for the detection and identification of 5 common enteric parasites: Blastocystis spp., Cryptosporidium spp., Dientamoeba fragilis, Entamoeba complex, and Giardia intestinalis in human clinical samples. A total of 358 faecal samples were included in the study. When compared to real-time PCR and microscopy, the EasyScreen™ Enteric Parasite Detection Kit exhibited 92-100% sensitivity and 100% specificity and detected all commonly found genotypes and subtypes of clinically important human parasites. No cross reactivity was detected in stool samples containing various other bacterial, viral, and/or protozoan species. The EasyScreen™ PCR assay was able to provide rapid, sensitive, and specific simultaneous detection and identification of the 5 most important diarrhoea-causing enteric parasites that infect humans. It should be noted, however, that the EasyScreen™ Kit does not substitute for microscopy or for additional PCRs as it does not detect the pathogenic Coccidia spp. Cystoisospora belli or Cyclospora cayetanensis and it does not differentiate between pathogenic and nonpathogenic Entamoeba spp. This study also highlights the lack of sensitivity demonstrated by microscopy; as such, molecular methods should be considered the diagnostic method of choice for enteric parasites. PMID:24286625

Stark, D; Roberts, T; Ellis, J T; Marriott, D; Harkness, J

2014-02-01

382

Giardia muris trophozoite antigenic targets for mouse intestinal IgA antibody.  

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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. PMID:8106773

Heyworth, M F; Vergara, J A

1994-02-01

383

In vitro activity of the F-6 fraction of oregano against Giardia intestinalis.  

Science.gov (United States)

Giardiosis is a neglected parasitic disease that produces diarrhoea and different degrees of malabsorption in humans and animals. Its treatment is based on derivatives of 5-nitroimidazoles, benzimidazoles, nitrofuranes, acridine and nitrotiazoles. These drugs produce undesirable secondary effects, ranging from a metallic taste in the mouth to genetic damage and the selection of resistant strains; therefore, it is necessary to develop new therapeutic alternatives. We demonstrated that a 2-h treatment with 2·87 ?g ml(-1) of fraction 6 of Lippia graveolens (F-6) was sufficient to kill half of an experimental Giardia intestinalis (Syn. G. duodenalis, G. lamblia) population, based on the reduction of MTT-tetrazolium salt levels. F-6 breaks the nuclear envelope and injures the ventral suckling disc. The major compounds of F-6 were characterized as naringenin, thymol, pinocembrin and traces of compounds not yet identified. The results suggest that Lippia is a potential source to obtain compounds with anti-Giardia activity. This knowledge is an important starting point to develop new anti-giardial drugs. Future studies will be required to establish the efficacy of F-6 in vivo using an animal model. PMID:22309702

Rufino-González, Yadira; Ponce-Macotela, Martha; González-Maciel, Angélica; Reynoso-Robles, Rafael; Jiménez-Estrada, Manuel; Sánchez-Contreras, Ángeles; Martínez-Gordillo, Mario N

2012-04-01

384

PARASITES OF MAN IN SERANG, WEST JAVA  

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Full Text Available Survey penyakit menular didesa Cikurai dan Barengkok, Jawa Barat pada bulan Juni 1974 ini adalah merupakan salah satu dari serangkaian survey yang dilakukan oleh Direktorat Jenderal P3.M. Dep. Kes. dan US Namru-2 guna menentukan distribusi dan prevalensi penyakit terutama malaria, filariasis dan penyakit parasit perut. Khususnya didaerah Cikurai dimana dilaporkan adanya Schistosoma in­cognitum secara hyperenzootik maka perlulah dilihat apakah parasit ini ditemukan pula diantara pend-duk setempat. Dari hasil survey didesa Cikurai dan Barengkok, Jawa Barat ini dilihat bahwa Plasmodium falciparum ditemukan pada 8 atau 3 persen dari sediaan darah 261 penduduk yang diperiksa dan tidak terlihat adanya microfilariae. Parasit perut yang menonjol terlihat pada sediaan tinja dari 335 penduduk yang diperiksa adalah Ascaris lumbricoides, Trichuris trichiura dan cacing tambang masing-masing sebesar 89 persen, 87 persen dan 65 persen ; parasit lainnya adalah Entamoeba histolytica, Entamoeba hart manni, Entamoeba coli, Endolinuu nana, lodamoeba butschlii, Giardia lamblia, Chilomastvc mesnili, Enterobius vermicularis, dan Echinostoma sp. Tidak terlihat adanya Schistosoma incognitum pada sediaan tinja dari 335 penduduk yang diperiksa dikedua desa ini.

W. P. Carney

2012-09-01

385

Evaluation of Three Commercial Assays for Detection of Giardia and Cryptosporidium Organisms in Fecal Specimens  

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There is an increasing demand for diagnostic testing for Giardia intestinalis (G. lamblia) and Cryptosporidium parvum, with a priority being placed on obtaining diagnostic results in an efficient and timely manner. Several commercial companies have developed rapid diagnostic tests that are simple to perform and can be completed in less time than traditional methods for detecting Giardia and Cryptosporidium. We compared one of these rapid tests, the ImmunoCard STAT! (Meridian Bioscience, Inc.)...

Johnston, Stephanie P.; Ballard, Melissa M.; Beach, Michael J.; Causer, Louise; Wilkins, Patricia P.

2003-01-01

386

Intestinal parasitic infection among children and neonatus admitted to Ibn-Sina Hospital, Sirt, Libya.  

Science.gov (United States)

A total of 350 stool samples from 196 males and 154 female children and neonatus admitted in Ibn-Sina hospital, Sirt, were examined from June 2001 to May 2002, to determine the prevalence of intestinal parasites. Intestinal parasitic infections were identified in 196 (56%) of children and neonates. No intestinal helminthic parasites were detected but 13 intestinal protozoan parasites were detected. The most prevalent protozoan was Entamoeba histolytica /E. dispar (36.57%); Blastocystis hominis (12.57%), Giardia lamblia (10.29%), Isospora belli (3.14%) and Balantidium coli (0.86%), the latter was detected in non-Libyan children. The non-pathogenic ones were Entamoeba coli (15.14%), Endolimax nana (13.71%), Entamoeba hartmanni (4.29%), Chilomastix mesnilli (4.29%), Retortamonas intestinalis (3.43%), Dientamoeba fragilis (2%), Iodamoeba butschlii (0.86%) and Trichomonas hominis (0.86%). The result showed a significant difference exists between the prevalence of pathogenic and non-pathogenic protozoan parasites (P < 0.05). High prevalence of E. histolytica/ E. dispar followed by E. coli, E. nana, B. hominis and G. lamblia in both sexes of children, while the prevalence of other intestinal parasites were low in both sexes, significantly different existed in the prevalence of intestinal parasites between males and females children (t = 24.68; P < 0.05). Age groups had no effect on the prevalence of intestinal parasites (F = 0.66; P < 0.05). Significant differences existed in the prevalence between single and multiple infections with pathogenic protozoa. The socio-economic status of children parents revealed that high prevalence in children from medium socio-economic status. The family size had no significant effect on the prevalence of the intestinal parasites. PMID:17985574

Kasssem, Hamed H; Zaed, Hana Abdalsalam; Sadaga, Gazala A

2007-08-01

387

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

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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 result...

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

1988-01-01

388

Sensitive Detection of Giardia Cysts by Polymerase Chain Reaction (PCR)  

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Giardia is one of the most common human parasites and causes a lengthly course of nonbacterial diarrhea. Disease outbreaks due to Giardia infection are often attributed to contaminated water supplies. A major problem associated with detection for this organism is the lack of sensitive and reliable methods. PCR has the potential to address many of the limitations.We have performed a PCR-based method for sensitive detection of Giardia cysts. Because the sensitivity of PCR is a function of the e...

Nikaeen, M.; Ar, Mesdaghinia; Jeddi Tehrani, M.; Rezaian, M.; Vaezi, F.

2003-01-01

389

Modeling parasite infection dynamics when there is heterogeneity and imperfect detectability.  

Science.gov (United States)

Understanding the infection and recovery rate from parasitic infections is valuable for public health planning. Two challenges in modeling these rates are (1) infection status is only observed at discrete times even though infection and recovery take place in continuous time and (2) detectability of infection is imperfect. We address these issues through a Bayesian hierarchical model based on a random effects Weibull distribution. The model incorporates heterogeneity of the infection and recovery rate among individuals and allows for imperfect detectability. We estimate the model by a Markov chain Monte Carlo algorithm with data augmentation. We present simulation studies and an application to an infection study about the parasite Giardia lamblia among children in Kenya. PMID:23848564

Cui, Na; Chen, Yuguo; Small, Dylan S

2013-09-01

390

Intestinal parasitic infections and eosinophilia in an human immunedeficiency virus positive population in Honduras  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The occurrence of intestinal parasites, their regional distribution and their relations to eosinophilia were studied in 133 human immunodeficiency virus (HIV) positive individuals from Honduras. After signing an informed consent, participants answered a socio-demographic and risk factor questionnair [...] e, a complete physical examination, medical history, and a series of laboratory tests. All participants were HIV positive but not acquired immunodeficiency syndrome positive. Of them, 67% were co-infected with pathogen and non pathogen parasites. Overall occurrence of nematodes was: 44.3% for Trichuris trichiura, 24% for Ascaris lumbricoides, 12% for Hookworm and 7.5% for Strongyloides stercoralis. No cases of Giardia lamblia, acute amebiasis or cryptosporidiasis were d