This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Adam, R D Search for Related Content PubMed PubMed Citation Articles by Adam, R D

The biology of Giardia spp.

Department of Internal Medicine, University of Arizona, Tucson 85724.

SUMMARY

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

This article has been cited by other articles:

• Morrison, H. G., McArthur, A. G., Gillin, F. D., Aley, S. B., Adam, R. D., Olsen, G. J., Best, A. A., Cande, W. Z., Chen, F., Cipriano, M. J., Davids, B. J., Dawson, S. C., Elmendorf, H. G., Hehl, A. B., Holder, M. E., Huse, S. M., Kim, U. U., Lasek-Nesselquist, E., Manning, G., Nigam, A., Nixon, J. E. J., Palm, D., Passamaneck, N. E., Prabhu, A., Reich, C. I., Reiner, D. S., Samuelson, J., Svard, S. G., Sogin, M. L. (2007). Genomic Minimalism in the Early Diverging Intestinal Parasite Giardia lamblia. Science 317: 1921-1926 [Abstract] [Full Text]  
• Troeger, H., Epple, H.-J., Schneider, T., Wahnschaffe, U., Ullrich, R., Burchard, G.-D., Jelinek, T., Zeitz, M., Fromm, M., Schulzke, J.-D. (2007). Effect of chronic Giardia lamblia infection on epithelial transport and barrier function in human duodenum. Gut 56: 328-335 [Abstract] [Full Text]  
• Ali, V., Nozaki, T. (2007). Current Therapeutics, Their Problems, and Sulfur-Containing-Amino-Acid Metabolism as a Novel Target against Infections by "Amitochondriate" Protozoan Parasites. Clin. Microbiol. Rev. 20: 164-187 [Abstract] [Full Text]  
• Morelle, W., Jimenez, J.-C., Cieniewski-Bernard, C., Dei-Cas, E., Michalski, J.-C. (2005). Characterization of the N-linked glycans of Giardia intestinalis. Glycobiology 15: 549-559 [Abstract] [Full Text]  
• Worgall, T. S., Davis-Hayman, S. R., Magana, M. M., Oelkers, P. M., Zapata, F., Juliano, R. A., Osborne, T. F., Nash, T. E., Deckelbaum, R. J. (2004). Sterol and fatty acid regulatory pathways in a Giardia lamblia-derived promoter: evidence for SREBP as an ancient transcription factor. J. Lipid Res. 45: 981-988 [Abstract] [Full Text]  
• Sun, C.-H., McCaffery, J. M., Reiner, D. S., Gillin, F. D. (2003). Mining the Giardia lamblia Genome for New Cyst Wall Proteins. J. Biol. Chem. 278: 21701-21708 [Abstract] [Full Text]  
• Reiner, D. S., Hetsko, M. L., Meszaros, J. G., Sun, C.-H., Morrison, H. G., Brunton, L. L., Gillin, F. D. (2003). Calcium Signaling in Excystation of the Early Diverging Eukaryote, Giardia lamblia. J. Biol. Chem. 278: 2533-2540 [Abstract] [Full Text]  
• Sarver, A. E., Wang, C. C. (2002). The Adenine Phosphoribosyltransferase from Giardia lamblia Has a Unique Reaction Mechanism and Unusual Substrate Binding Properties. J. Biol. Chem. 277: 39973-39980 [Abstract] [Full Text]  
• Gerwig, G. J., van Kuik, J. A., Leeflang, B. R., Kamerling, J. P., Vliegenthart, J. F.G., Karr, C. D., Jarroll, E. L. (2002). The Giardia intestinalis filamentous cyst wall contains a novel {beta}(1-3)-N-acetyl-D-galactosamine polymer: a structural and conformational study. Glycobiology 12: 499-505 [Abstract] [Full Text]  
• Yu, L. Z., Birky, C. W. Jr., Adam, R. D. (2002). The Two Nuclei of Giardia Each Have Complete Copies of the Genome and Are Partitioned Equationally at Cytokinesis. Eukaryot Cell 1: 191-199 [Abstract] [Full Text]  
• Lloyd, D., Ralphs, J. R., Harris, J. C. (2002). Giardia intestinalis, a eukaryote without hydrogenosomes, produces hydrogen. Microbiology 148: 727-733 [Abstract] [Full Text]  
• Touz, M. C., Nores, M. J., Slavin, I., Carmona, C., Conrad, J. T., Mowatt, M. R., Nash, T. E., Coronel, C. E., Lujan, H. D. (2002). The Activity of a Developmentally Regulated Cysteine Proteinase Is Required for Cyst Wall Formation in the Primitive Eukaryote Giardia lamblia. J. Biol. Chem. 277: 8474-8481 [Abstract] [Full Text]  
• Amar, C. F. L., Dear, P. H., Pedraza-Diaz, S., Looker, N., Linnane, E., McLauchlin, J. (2002). Sensitive PCR-Restriction Fragment Length Polymorphism Assay for Detection and Genotyping of Giardia duodenalis in Human Feces. J. Clin. Microbiol. 40: 446-452 [Abstract] [Full Text]  
• Langford, T. D., Housley, M. P., Boes, M., Chen, J., Kagnoff, M. F., Gillin, F. D., Eckmann, L. (2002). Central Importance of Immunoglobulin A in Host Defense against Giardia spp.. Infect. Immun. 70: 11-18 [Abstract] [Full Text]  
• Biagini, G. A., Park, J. H., Lloyd, D., Edwards, M. R. (2001). The antioxidant potential of pyruvate in the amitochondriate diplomonads Giardia intestinalis and Hexamita inflata. Microbiology 147: 3359-3365 [Abstract] [Full Text]  
• Elmendorf, H. G., Singer, S. M., Nash, T. E. (2001). The abundance of sterile transcripts in Giardia lamblia. Nucleic Acids Res 29: 4674-4683 [Abstract] [Full Text]  
• Aronov, A. M., Munagala, N. R., Kuntz, I. D., Wang, C. C. (2001). Virtual Screening of Combinatorial Libraries across a Gene Family: in Search of Inhibitors of Giardia lamblia Guanine Phosphoribosyltransferase. Antimicrob. Agents Chemother. 45: 2571-2576 [Abstract] [Full Text]  
• McArthur, A. G., Knodler, L. A., Silberman, J. D., Davids, B. J., Gillin, F. D., Sogin, M. L. (2001). The Evolutionary Origins of Eukaryotic Protein Disulfide Isomerase Domains: New Evidence from the Amitochondriate Protist Giardia lamblia. Mol Biol Evol 18: 1455-1463 [Abstract] [Full Text]  
• Adam, R. D. (2001). Biology of Giardia lamblia. Clin. Microbiol. Rev. 14: 447-475 [Abstract] [Full Text]  
• Morrison, H. G., Roger, A. J., Nystul, T. G., Gillin, F. D., Sogin, M. L. (2001). Giardia lamblia Expresses a Proteobacterial-like DnaK Homolog. Mol Biol Evol 18: 530-541 [Abstract] [Full Text]  
• Sánchez, L. B., Elmendorf, H., Nash, T. E., Müller, M. (2001). NAD(P)H:menadione oxidoreductase of the amitochondriate eukaryote Giardia lamblia: a simpler homologue of the vertebrate enzyme. Microbiology 147: 561-570 [Abstract] [Full Text]  
• Upcroft, P., Upcroft, J. A. (2001). Drug Targets and Mechanisms of Resistance in the Anaerobic Protozoa. Clin. Microbiol. Rev. 14: 150-164 [Abstract] [Full Text]  
• Eckmann, L., Gillin, F. D. (2001). Microbes and Microbial Toxins: Paradigms for Microbial- Mucosal Interactions I. Pathophysiological aspects of enteric infections with the lumen-dwelling protozoan pathogen Giardia lamblia. Am. J. Physiol. Gastrointest. Liver Physiol. 280: G1-G6 [Abstract] [Full Text]  
• Wu, G., McArthur, A. G., Fiser, A., Sogin, M. L., M, M. (2000). Core Histones of the Amitochondriate Protist, Giardia lamblia. Mol Biol Evol 17: 1156-1163 [Abstract] [Full Text]  
• Hehl, A. B., Marti, M., Köhler, P. (2000). Stage-Specific Expression and Targeting of Cyst Wall Protein-Green Fluorescent Protein Chimeras in Giardia. Mol. Biol. Cell 11: 1789-1800 [Abstract] [Full Text]  
• Yee, J., Mowatt, M. R., Dennis, P. P., Nash, T. E. (2000). Transcriptional Analysis of the Glutamate Dehydrogenase Gene in the Primitive Eukaryote, Giardia lamblia. IDENTIFICATION OF A PRIMORDIAL GENE PROMOTER. J. Biol. Chem. 275: 11432-11439 [Abstract] [Full Text]  
• TORRES, M. F., UETANABARO, A. P. T., COSTA, A. F., ALVES, C. A., FARIAS, L. M., BAMBIRRA, E. A., PENNA, F. J., VIEIRA, E. C., NICOLI, J. R. (2000). Influence of bacteria from the duodenal microbiota of patients with symptomatic giardiasis on the pathogenicity of Giardia duodenalis in gnotoxenic mice. J Med Microbiol 49: 209-215 [Abstract] [Full Text]  
• Eckmann, L., Laurent, F., Langford, T. D., Hetsko, M. L., Smith, J. R., Kagnoff, M. F., Gillin, F. D. (2000). Nitric Oxide Production by Human Intestinal Epithelial Cells and Competition for Arginine as Potential Determinants of Host Defense Against the Lumen-Dwelling Pathogen Giardia lamblia. J. Immunol. 164: 1478-1487 [Abstract] [Full Text]  
• Faubert, G. (2000). Immune Response to Giardia duodenalis. Clin. Microbiol. Rev. 13: 35-54 [Abstract] [Full Text]  
• Singer, S. M., Nash, T. E. (2000). T-Cell-Dependent Control of Acute Giardia lamblia Infections in Mice. Infect. Immun. 68: 170-175 [Abstract] [Full Text]  
• Knodler, L. A., Noiva, R., Mehta, K., McCaffery, J. M., Aley, S. B., Svard, S. G., Nystul, T. G., Reiner, D. S., Silberman, J. D., Gillin, F. D. (1999). Novel Protein-disulfide Isomerases from the Early-diverging Protist Giardia lamblia. J. Biol. Chem. 274: 29805-29811 [Abstract] [Full Text]  
• Sun, C.-H., Tai, J.-H. (1999). Identification and Characterization of a ran Gene Promoter in the Protozoan Pathogen Giardia lamblia. J. Biol. Chem. 274: 19699-19706 [Abstract] [Full Text]  
• Samuelson, J. (1999). Why Metronidazole Is Active against both Bacteria and Parasites. Antimicrob. Agents Chemother. 43: 1533-1541 [Full Text]  
• Gupta, R. S. (1998). Protein Phylogenies and Signature Sequences: A Reappraisal of Evolutionary Relationships among Archaebacteria, Eubacteria, and Eukaryotes. Microbiol. Mol. Biol. Rev. 62: 1435-1491 [Abstract] [Full Text]  
• Park, J.-H., Edwards, M. R., Schofield, P. J. (1998). Swelling detection for volume regulation in the primitive eukaryote Giardia intestinalis: a common feature of volume detection in present-day eukaryotes. FASEB J. 12: 571-579 [Abstract] [Full Text]  
• Roger, A. J., Svard, S. G., Tovar, J., Clark, C. G., Smith, M. W., Gillin, F. D., Sogin, M. L. (1998). A mitochondrial-like chaperonin 60 gene in Giardia lamblia: Evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria. Proc. Natl. Acad. Sci. USA 95: 229-234 [Abstract] [Full Text]  
• Upcroft, P, Chen, N, Upcroft, J A (1997). Telomeric organization of a variable and inducible toxin gene family in the ancient eukaryote Giardia duodenalis.. Genome Res. 7: 37-46 [Abstract]  
• Soltys, B., Falah, M, Gupta, R. (1996). Identification of endoplasmic reticulum in the primitive eukaryote Giardia lamblia using cryoelectron microscopy and antibody to Bip. J. Cell Sci. 109: 1909-1917 [Abstract]  
• Luján, H. D., Mowatt, M. R., Conrad, J. T., Bowers, B., Nash, T. E. (1995). Identification of a Novel Giardia lamblia Cyst Wall Protein with Leucine-rich Repeats. J. Biol. Chem. 270: 29307-29313 [Abstract] [Full Text]  
• Luján, H. D., Mowatt, M. R., Wu, J.-j., Lu, Y., Lees, A., Chance, M. R., Nash, T. E. (1995). Purification of a Variant-specific Surface Protein of Giardia lamblia and Characterization of its Metal-binding Properties. J. Biol. Chem. 270: 13807-13813 [Abstract] [Full Text]  
• Luján, H. D., Marotta, A., Mowatt, M. R., Sciaky, N., Lippincott-Schwartz, J., Nash, T. E. (1995). Developmental Induction of Golgi Structure and Function in the Primitive Eukaryote Giardia lamblia. J. Biol. Chem. 270: 4612-4618 [Abstract] [Full Text]  
• Marshall, J, Holberton, D. (1995). Giardia gene predicts a 183 kDa nucleotide-binding head-stalk protein. J. Cell Sci. 108: 2683-2692 [Abstract]  
• Abel, E. S., Davids, B. J., Robles, L. D., Loflin, C. E., Gillin, F. D., Chakrabarti, R. (2001). Possible Roles of Protein Kinase A in Cell Motility and Excystation of the Early Diverging Eukaryote Giardia lamblia. J. Biol. Chem. 276: 10320-10329 [Abstract] [Full Text]  
• Munagala, N., Sarver, A. E., Wang, C. C. (2000). Converting the Guanine Phosphoribosyltransferase from Giardia lamblia to a Hypoxanthine-guanine Phosphoribosyltransferase. J. Biol. Chem. 275: 37072-37077 [Abstract] [Full Text]  
• Biagini, G. A., Knodler, L. A., Saliba, K. J., Kirk, K., Edwards, M. R. (2001). Na+-dependent pH Regulation by the Amitochondriate Protozoan Parasite Giardia intestinalis. J. Biol. Chem. 276: 29157-29162 [Abstract] [Full Text]  
• Bunjun, S., Stathopoulos, C., Graham, D., Min, B., Kitabatake, M., Wang, A. L., Wang, C. C., Vivares, C. P., Weiss, L. M., Soll, D. (2000). A dual-specificity aminoacyl-tRNA synthetase in the deep-rooted eukaryote Giardia lamblia. Proc. Natl. Acad. Sci. USA 97: 12997-13002 [Abstract] [Full Text]