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Patrick T. K. Woo - One of the best experts on this subject based on the ideXlab platform.
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selected parasitosis in cultured and wild fish
Veterinary Parasitology, 2009Co-Authors: F C Guo, Patrick T. K. WooAbstract:While intensive aquaculture has and will continue to supply the ever growing population with highly nutritious protein, it also comes with problems which include more frequent outbreaks of diseases in fish farms and transmission of diseases between farmed and wild fish. We have selected four Phyla of economically important fish parasites for our present discussion—a haemoflagellate (Cryptobia salmositica), a microsporidian, (Loma salmonae), a monogenean (Gyrodactylus salaries) and two copepods (Lepeophtheirus salmonis, Caligus rogercresseyi). This review consists of two parts with a brief description of each parasite and its biology related to transmission, followed by discussions on epizootic outbreaks in both wild and farmed fish, interactions between wild and farmed fish, and disease prevention and control.
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A S-adenosylmethionine synthetase gene from the pathogenic piscine Hemoflagellate, Cryptobia salmositica
Parasitology Research, 2007Co-Authors: Palmy R. Jesudhasan, Patrick T. K. WooAbstract:We report on the identification of a Cryptobia genomic DNA gene, predict it to encode a S -adenosylmethionine synthetase signature 1 motif and propose to name it S -adenosylmethionine synthetase ( MAT ). The open reading frame of MAT is 1,046 bp with 341 deduced amino acids. The MAT gene was identified using universal genome walking and Southern blot analysis revealed it to be a multi-copy gene. The S -adenosylmethionine synthetase of Cryptobia salmositica amino acid sequence is similar to those of other pathogenic kinetoplastids ( Leishmania donovani 71%, Leishmania major 70%, Leishmania infantum 71%, Trypanosoma brucei 72%, Trypanosoma cruzi 70% and T. cruzi strain CL Brener 70%). The C. salmositica MAT has a conserved hexapeptide GAGDQG, which is widely found in bacteria, parasitic protozoans and also in humans. These suggest that MAT may have highly conserved functions such as regulation of gene expression and biosynthesis of a multitude of essential metabolites.
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A metalloproteinase gene from the pathogenic piscine Hemoflagellate, Cryptobia salmositica
Parasitology Research, 2007Co-Authors: Palmy R. Jesudhasan, Chung-wei Tan, Patrick T. K. WooAbstract:We report the identification of a Cryptobia genomic DNA gene predicted to encode a hydrophobic protein containing a zinc metalloproteinase motif, HEXXH , and hence named it a major surface proteinase 1-like (MSP-1). The MSP-1 gene was identified using universal genome walking. Southern blot analysis revealed it to be a multicopy gene. Fragments of DNA encoding a segment homologous to the HEXXH motif of MSP-1 are widely found in bacteria, yeast, parasitic protozoans, plants, and animals including humans. These results suggest that the MSP-1 may have highly conserved functions, such as in intracellular proteolysis.
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A cathepsin L-like cysteine proteinase gene from the protozoan parasite, Cryptobia salmositica
Parasitology research, 2006Co-Authors: Palmy R. Jesudhasan, Chung-wei Tan, Nikos Hontzeas, Patrick T. K. WooAbstract:The present study describes the identification of a cathepsin L-like cysteine proteinase gene (CYS) from the Hemoflagellate Cryptobia salmositica. Genomic DNA sequence of cysteine proteinase was obtained by genome walking using degenerate primers. Specific primers were designed to amplify the cDNA of cysteine proteinase from mRNA by rapid amplification of cDNA ends-PCR. The open reading frame of CYS is 1,329 bp, with 443 deduced amino acids. Based on the sequence analysis, cysteine proteinase of C. salmositica is similar to the cathepsin L-like cysteine proteinase of kinetoplastid parasites such as Leishmania spp. and Trypanosoma spp. The identification of CYS proteinase gene could help to design cysteine proteinase specific inhibitors. Further studies are required to characterize the complete genomic organization of the cysteine proteinase.
Hemanta K. Majumder - One of the best experts on this subject based on the ideXlab platform.
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A Novel Endonuclease from Kinetoplastid Hemoflagellated Protozoan Parasite Leishmania
Journal of biochemistry, 1998Co-Authors: Bidyottam Mittra, Pranab K. Sadhukhan, Hemanta K. MajumderAbstract:A nuclease activity has been purified from the nuclei-kinetoplast fraction of Leishmania. This enzyme, termed endonuclease M (Endo M), is shown by electrophoresis in a denaturing polyacrylamide gel to be associated with a single polypeptide of molecular mass 52 kDa. Physical analysis of the enzyme indicates that it has a sedimentation coefficient S20,w of 4.5S, a Stoke's radius of 32.5 A, and a native molecular mass of 53 kDa. The final Mono Q purified Endo M possesses both DNase and RNase activities. It acts as an endonuclease by introducing random single-stranded nicks into the supercoiled DNA molecules, that often leads to its linearization due to nicking at the opposite strands, and subsequent degradation of the DNA with further incubation. Single-stranded DNA is twice preferred to double-stranded DNA as substrate. Single-stranded RNA is also degraded rapidly and is competitive as a substrate with single-stranded DNA. RNA:DNA hybrids, however, are largely resistant to the Endo M digestion.
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An ATP-independent catenating enzyme from the kinetoplast Hemoflagellate Leishmaniadonovani
Biochemical and biophysical research communications, 1991Co-Authors: Asit K. Chakraborty, Hemanta K. MajumderAbstract:An enzyme from Leishmania donovani that catenates monomeric pBR322 into huge catenanes has been isolated and characterized. The enzyme also decatenates kinetoplast DNA networks into covalently closed monomeric circles and relaxes supercoiled pBR322. The catenation, decatenation and relaxation reactions do not require ATP. The formation of topological isomers of unique linking numbers suggest that the enzyme is a type II DNA topoisomerase.
Edmundo C Grisard - One of the best experts on this subject based on the ideXlab platform.
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TRENDS ON TRYPANOSOMA (HERPETOSOMA) RANGELI RESEARCH TENDENCIAS EN INVESTIGACIONES DE TRYPANOSOMA (HERPETOSOMA) RANGELI
2006Co-Authors: Ethel Bayer-santos, Mario Steindel, Thaís Cristine, Marques Sincero, Patrícia Hermes Stoco, Edmundo C GrisardAbstract:Trypanosoma rangeli is a Hemoflagellate protozoan parasite presenting an overlapping distribution with T. cruzi, the etiological agent of Chagas disease, in a wide geographical area in Latin America. Despite considered as non-pathogenic for man, T. rangeli shares several characteristics with T. cruzi such as vertebrate and invertebrate reservoirs, vectors and approximately half of the soluble antigenic determinants. Despite the importance of specific detection, little is know about T. rangeli
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trypanosoma rangeli transcriptome project generation and analysis of expressed sequence tags
Kinetoplastid Biology and Disease, 2004Co-Authors: Cristiane Q Snoeijer, Gisele Fernanda Assine Picchi, Bibiana Paula Dambros, Stenio Perdigao Fragoso, Daniel M Lorenzini, Mario Steindel, Samuel Goldenberg, Edmundo C GrisardAbstract:Trypanosoma rangeli is an important Hemoflagellate parasite of several mammalian species in Central and South America, sharing geographical areas, vectors and reservoirs with T. cruzi, the causative agent of Chagas disease. Thus, the occurrence of single and/or mixed infections, including in humans, must be expected and are of great importance for specific diagnosis and epidemiology. In comparison to several Trypanosomatidae species, the T. rangeli biology and genome are little known, reinforcing the needs of a gene discovery initiative. The T. rangeli transcriptome initiative aims to promote gene discovery through the generation of expressed sequence tags (ESTs) and Orestes (ORF ESTs) from both epimastigote and trypomastigote forms of the parasite, allowing further studies of the parasite biology, taxonomy and phylogeny.
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Trypanosoma rangeliTranscriptome Project: Generation and analysis of expressed sequence tags
Kinetoplastid Biology and Disease, 2004Co-Authors: Cristiane Q Snoeijer, Gisele Fernanda Assine Picchi, Bibiana Paula Dambros, Stenio Perdigao Fragoso, Daniel M Lorenzini, Mario Steindel, Samuel Goldenberg, Edmundo C GrisardAbstract:Trypanosoma rangeli is an important Hemoflagellate parasite of several mammalian species in Central and South America, sharing geographical areas, vectors and reservoirs with T. cruzi , the causative agent of Chagas disease. Thus, the occurrence of single and/or mixed infections, including in humans, must be expected and are of great importance for specific diagnosis and epidemiology. In comparison to several Trypanosomatidae species, the T. rangeli biology and genome are little known, reinforcing the needs of a gene discovery initiative. The T. rangeli transcriptome initiative aims to promote gene discovery through the generation of expressed sequence tags (ESTs) and Orestes (ORF ESTs) from both epimastigote and trypomastigote forms of the parasite, allowing further studies of the parasite biology, taxonomy and phylogeny.
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Kinetoplastid Biology and Disease BioMed Central Focus Trypanosoma rangeli Transcriptome Project: Generation and analysis of expressed sequence tags
2004Co-Authors: Cristiane Q Snoeijer, Bibiana Paula Dambros, Stenio Perdigao Fragoso, Daniel M Lorenzini, Mario Steindel, Samuel Goldenberg, Gisele Fern, A Picchi, Edmundo C GrisardAbstract:© 2004 Snoeijer et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. Trypanosoma rangeli is an important Hemoflagellate parasite of several mammalian species in Central and South America, sharing geographical areas, vectors and reservoirs with T. cruzi, the causative agent of Chagas disease. Thus, the occurrence of single and/or mixed infections, including in humans, must be expected and are of great importance for specific diagnosis and epidemiology. In comparison to several Trypanosomatidae species, the T. rangeli biology and genome are little known, reinforcing the needs of a gene discovery initiative. The T. rangeli transcriptome initiative aims to promote gene discovery through the generation of expressed sequence tags (ESTs) and Orestes (ORF ESTs) from both epimastigote and trypomastigote forms of the parasite, allowing further studies of the parasite biology, taxonomy and phylogeny. The Trypanosoma rangeli EST project Trypanosoma rangeli and T. cruzi are Hemoflagellate protozoan parasites transmitted by triatomine bugs in a wide
Rosa M Reguera - One of the best experts on this subject based on the ideXlab platform.
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gene disruption of the dna topoisomerase ib small subunit induces a non viable phenotype in the Hemoflagellate leishmania major
BMC Microbiology, 2008Co-Authors: Rafael Balanafouce, Carlos Garciaestrada, Yolanda Perezpertejo, Rosa M RegueraAbstract:Background The unusual heterodimeric leishmanial DNA topoisomerase IB consists of a large subunit containing the phylogenetically conserved "core" domain, and a small subunit harboring the C-terminal region with the characteristic tyrosine residue in the active site. RNAi silencing of any of both protomers induces a non-viable phenotype in the hemoflagelate Trypanosoma brucei. Unfortunately, this approach is not suitable in Leishmania where gene replacement with an antibiotic marker is the only approach to generate lack-of-function mutants. In this work, we have successfully generated null mutants in the small subunit of the L. major DNA topoisomerase IB using two selection markers, each conferring resistance to hygromycin B and puromycin, respectively.
Rachel Kaminsky - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of dl-α-difluoromethylornithine against susceptible and drug-resistant Trypanosoma brucei brucei
Acta Tropica, 1991Co-Authors: Erich Zweygarth, Rachel KaminskyAbstract:Abstract The antitrypanosomal activity of the ornithine decarboxylase inhibitor dl -α-difluoromethylornithine (DFMO, eflornithine) was tested in ten stocks and one clone of the Hemoflagellate Trypanosoma brucei brucei in an in vitro system. They showed varying levels of susceptibility to DFMO, their IC 50 (the concentration which inhibited growth by 50%) values ranging from 81–691 μM. Differences in DFMO susceptibility were also demonstrated in mice. Combinations of melarsonyl potassium (mel W; trimelarsan) and DFMO showed an additive effect in vitro in a mel W-susceptible and a mel W-resistant stock, but an antagonistic effect in a mel W- and DFMO-susceptible clone. Combinations of suramin and DFMO showed an antagonistic effect in vitro in a suramin-susceptible clone, but a potentiation in a suramin-resistant stock.