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Sent on Wednesday, 2011 Nov 02Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | J Clin Microbiol. 2011 Nov;49(11):3892-904.Serial Quantitative PCR Assay for Detection, Species Discrimination, and Quantification of Leishmania spp. in Human Samples.Weirather JL, Jeronimo SM, Gautam S, Sundar S, Kang M, Kurtz MA, Haque R, Schriefer A, Talhari S, Carvalho EM, Donelson JE, Wilson ME.SourceInternal Medicine and Microbiology, University of Iowa, SW34-GH, 200 Hawkins Dr., Iowa City, IA 52242. mary-wilson@uiowa.edu. AbstractThe Leishmania species cause a variety of human disease syndromes. Methods for diagnosis and species differentiation are insensitive and many require invasive sampling. Although quantitative PCR (qPCR) methods are reported for leishmania detection, no systematic method to quantify parasites and determine the species in clinical specimens is established. We developed a serial qPCR strategy to identify and rapidly differentiate Leishmania species and quantify parasites in clinical or environmental specimens. SYBR green qPCR is mainly employed, with corresponding TaqMan assays for validation. The screening primers recognize kinetoplast minicircle DNA of all Leishmania species. Species identification employs further qPCR set(s) individualized for geographic regions, combining species-discriminating probes with melt curve analysis. The assay was sufficient to detect Leishmania parasites, make species determinations, and quantify Leishmania spp. in sera, cutaneous biopsy specimens, or cultured isolates from subjects from Bangladesh or Brazil with different forms of leishmaniasis. The multicopy kinetoplast DNA (kDNA) probes were the most sensitive and useful for quantification based on promastigote standard curves. To test their validity for quantification, kDNA copy numbers were compared between Leishmania species, isolates, and life stages using qPCR. Maxicircle and minicircle copy numbers differed up to 6-fold between Leishmania species, but the differences were smaller between strains of the same species. Amastigote and promastigote leishmania life stages retained similar numbers of kDNA maxi- or minicircles. Thus, serial qPCR is useful for leishmania detection and species determination and for absolute quantification when compared to a standard curve from the same Leishmania species. |
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| 2. | Am J Dermatopathol. 2011 Oct 29. [Epub ahead of print]Calcified Bodies in New World Cutaneous Leishmaniasis.Alvarez P, Salinas C, Bravo F.SourceFrom the *Laboratorio Universitario de Dermatopatologia, Universidad Peruana Cayetano Heredia, Lima, Peru; and †Servicio de Dermatologia, Hospital Nacional Cayetano Heredia, Lima, Peru. AbstractWe report a case of a 9-year-old boy who presented with 2 lesions that were compatible clinically with cutaneous leishmaniasis of the New World. A skin biopsy showed tuberculoid granulomas with rounded calcified bodies. The diagnosis was supported by a positive leishmanin test and a positive polymerase chain reaction. The patient responded to specific treatment for leishmaniasis. These calcified bodies, described under different names in the literature (Michaelis-Gutmann bodies, Schaumann bodies, psammoma bodies, or conchoidal bodies), have been reported in an experimental leishmaniasis and, only once before, in a case of human leishmaniasis of the Old World. |
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| 3. | Trop Biomed. 2011 Aug;28(2):411-7.In vitro cultivation of axenic amastigotes and the comparison of antioxidant enzymes at different stages of Leishmania tropica.Bahrami S, Hatam GR, Razavi M, Nazifi S.SourceDepartment of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran. AbstractThe present study aimed to establish a simple method to yield large amounts of Leishmania tropica amastigote-like forms in axenic cultures and to compare the superoxide dismutase (SOD) and glutathione peroxidase (GPX) enzymes at different stages of L. tropica. Different culture conditions were tested to find the optimum condition of axenic amastigotes generation. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were determined at logarithmic and stationary phases and axenic amastigote stage of the parasite. A high proportion (88%) of amastigote-like forms of L. tropica was observed in BHI medium supplemented with 20% FCS, pH 4.5, and incubated at 37ºC with 5% CO(2). The results showed that SOD activity was at the lowest level in the logarithmic phase of promastigotes and increased towards the stationary phase of promastigotes and amastigote stage. The results showed that the optimum condition for differentiation of L. tropica promastigotes to axenic amastigotes was BHI medium containing 20% FCS at pH 4.5, incubated at 37ºC in the presence of 5% CO(2). It seems that SOD, but not GPX is a major determinant of intracellular survival of the parasite. |
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| 4. | Trop Biomed. 2011 Aug;28(2):366-75.Seasonal distribution of phlebotomine sand flies (Diptera: Psychodidae) in Tham Phra Phothisat temple, Saraburi province, Thailand.Polseela R, Apiwathnasorn C, Samung Y.SourceDepartment of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand. AbstractPhlebotomine sand flies have long been incriminated as vectors of leishmaniasis in various parts of both the Old and New World. Prompted by recent indigenous cases of leishmaniasis in Thailand, a bionomic study of sand flies was undertaken in Tham Phra Phothisat temple, Saraburi province. In this study, sand flies were collected using Centers for Disease Control (CDC) light traps, to clarify the activity patterns and species composition of the sand flies. Traps were laid from August 2005 to July 2006. The insects were collected monthly between 1800-0600 hours. A total of 8,131 sand flies were collected with a female:male ratio of 1.9:1. Sixteen species were identified, of which 5 belonged to the genus Phlebotomus, 9 to Sergentomyia and 1 to Chinius. Species comprised the abundant species (Sergentomyia silvatica 35.6%, Sergentomyia barraudi 18.1%, Sergentomyia anodontis, 17.1%, Sergentomyia iyengari 11.9%, and Sergentomyia gemmea 11.2%); the less common species (<2%) were Sergentomyia dentata 1.8%, Phlebotomus stantoni 1.1%, Sergentomyia indica 1.0%, Phlebotomus argentipes 0.8%, Sergentomyia perturbans 0.4%, Chinius barbazani 0.3%, Phlebotomus asperulus 0.2%, Phlebotomus philippinensis gouldi 0.1%, Phlebotomus major major 0.1%, Sergentomyia quatei 0.1% and Sergentomyia bailyi 0.1%. The results revealed seasonal variation in sand fly prevalence, with the highest peak in July. Soil samples collected were characterized by alkaline (pH 7.6). |
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| 5. | Trop Biomed. 2011 Aug;28(2):259-68.Morphometric and meristic characterization of Phlebotomus argentipes species complex in northern Sri Lanka: evidence for the presence of potential leishmaniasis vectors in the country.Gajapathy K, Jude PJ, Surendran SN.SourceDepartment of Zoology, Faculty of Science, University of Jaffna, Jaffna 40000. AbstractThe transmission of cutaneous leishmaniasis (CL) is of public health concern in Sri Lanka. The parasite Leishmania donovani is reported to be the causative agent for CL in Sri Lanka. However there is no report on the vector of CL in the country. Phlebotomus argentipes sensu lato is the well known vector of L. donovani which causes visceral leishmaniasis (VL) in the nearby South India. The taxon Ph. argentipes previously reported to occur as a species complex comprising of two morphospecies namely A and B. The taxonomy of the Argentipes complex was reassessed recently and reported to have three species viz. Phlebotomus glaucus, Ph. argentipes sensu stricto and Ph. annandalei. A study was carried out in Jaffna mainland, where three CL patients have been recorded, and two associated islands in northern Sri Lanka to record the presence of the members of the Argentipes complex. Sandflies were collected using human landing and cattle baited collections. Collected samples were analyzed based on reported morphometric and meristic characteristics. The study revealed the presence of all three members of the complex in which Ph. glaucus and Ph. argentipes s.s. are reported for the first time in Sri Lanka. |
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| 6. | DNA Repair (Amst). 2011 Oct 29. [Epub ahead of print]Trypanosoma brucei AP endonuclease 1 has a major role in the repair of abasic sites and protection against DNA-damaging agents.Charret KS, Requena CE, Castillo-Acosta VM, Ruiz-Pérez LM, González-Pacanowska D, Vidal AE.SourceInstituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas (CSIC), Avda. del Conocimiento s/n, 18100 Armilla, Granada, Spain. AbstractDNA repair mechanisms guarantee the maintenance of genome integrity, which is critical for cell viability and proliferation in all organisms. As part of the cellular defenses to DNA damage, apurinic/apyrimidinic (AP) endonucleases repair the abasic sites produced by spontaneous hydrolysis, oxidative or alkylation base damage and during base excision repair (BER). Trypanosoma brucei, the protozoan pathogen responsible of human sleeping sickness, has a class II AP endonuclease (TBAPE1) with a high degree of homology to human APE1 and bacterial exonuclease III. The purified recombinant enzyme cleaves AP sites and removes 3'-phosphoglycolate groups from 3'-ends. To study its cellular function, we have established TBAPE1-deficient cell lines derived from bloodstream stage trypanosomes, thus confirming that the AP endonuclease is not essential for viability in this cell type under in vitro culture conditions. The role of TBAPE1 in the removal of AP sites is supported by the inverse correlation between the level of AP endonuclease in the cell and the number of endogenously generated abasic sites in its genomic DNA. Furthermore, depletion of TBAPE1 renders cells hypersensitive to AP site and strand break-inducing agents such as methotrexate and phleomycin respectively but not to alkylating agents. Finally, the increased susceptibility that TBAPE1-depleted cells show to nitric oxide suggests an essential role for this DNA repair enzyme in protection against the immune defenses of the mammalian host. Copyright © 2011 Elsevier B.V. All rights reserved. |
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| 7. | Biochem Biophys Res Commun. 2011 Oct 21. [Epub ahead of print]Identification of a second catalytically active trans-sialidase in Trypanosoma brucei.Nakatani F, Morita YS, Ashida H, Nagamune K, Maeda Y, Kinoshita T.SourceDepartment of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan. AbstractThe procyclic stage of Trypanosoma brucei is covered by glycosylphosphatidylinositol (GPI)-anchored surface proteins called procyclins. The procyclin GPI anchor contains a side chain of N-acetyllactosamine repeats terminated by sialic acids. Sialic acid modification is mediated by trans-sialidases expressed on the parasite's cell surface. Previous studies suggested the presence of more than one active trans-sialidases, but only one has so far been reported. Here we cloned and examined enzyme activities of four additional trans-sialidase homologs, and show that one of them, Tb927.8.7350, encodes another active trans-sialidase, designated as TbSA C2. In an in vitro assay, TbSA C2 utilized α2-3 sialyllactose as a donor, and produced an α2-3-sialylated product, suggesting that it is an α2-3 trans-sialidase. We suggest that TbSA C2 plays a role in the sialic acid modification of the trypanosome cell surface. Copyright © 2011. Published by Elsevier Inc. |
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| 8. | FEBS J. 2011 Sep 30. doi: 10.1111/j.1742-4658.2011.08379.x. [Epub ahead of print]3-(3-amino-3-carboxyprop yl)-5,6-Dihydrouridine is one of two novel post-transcriptional modifications in tRNA(Lys) (UUU) from Trypanosoma brucei.Krog JS, Español Y, Giessing AM, Dziergowska A, Malkiewicz A, de Pouplana LR, Kirpekar F.SourceDepartment of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark Institute for Research in Biomedicine, Barcelona, Spain Institute of Organic Chemistry, Technical University, Lodz, Poland. AbstracttRNA is the most heavily modified of all RNA types, with typically 10-20% of the residues being post-transcriptionally altered. Unravelling the modification pattern of a tRNA is a challenging task; there are 92 currently known tRNA modifications [1], many of which are chemically similar. Furthermore, the tRNA has to be investigated with single-nucleotide resolution in order to ensure complete mapping of all modifications. In the present work, we characterized tRNA(Lys) (UUU) from Trypanosoma brucei, and provide a complete overview of its post-transcriptional modifications. The first step was MALDI-TOF MS of two independent digests of the tRNA, with RNase A and RNase T1, respectively. This revealed digestion products harbouring mass-changing modifications. Next, the modifications were mapped at the nucleotide level in the RNase products by tandem MS. Comparison with the sequence of the unmodified tRNA revealed the modified residues. The modifications were further characterized at the nucleoside level by chromatographic retention time and fragmentation pattern upon higher-order tandem MS. Phylogenetic comparison with modifications in tRNA(Lys) from other organisms was used through the entire analysis. We identified modifications on 12 nucleosides in tRNA(Lys) (UUU), where U47 exhibited a novel modification, 3-(3-amino-3-carboxypropyl)-5,6-dihydrouridine, based on identical chromatographic retention and MS fragmentation as the synthetic nucleoside. A37 was observed in two versions: a minor fraction with the previously described 2-methylthio-N(6) -threonylcarbamoyl-modification, and a major fraction with A37 being modified by a 294.0-Da moiety. The latter product is the largest adenosine modification reported so far, and we discuss its nature and origin. © 2011 The Authors Journal compilation © 2011 FEBS. |
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| 9. | Curr Top Med Chem. 2011 Oct 27. [Epub ahead of print]Multi-Target-Directed Ligands as innovative tools to combat trypanosomatid diseases.Bolognesi ML.SourceDepartment of Pharmaceutical Sciences, University of Bologna, Via Belmeloro, 6, 40126 Bologna, Italy. marialaura.bolognesi@unibo.it. AbstractOf the tropical diseases, trypanosomiases and leishmaniases should most concern the pharmaceutical community because of their high prevalence in developing countries and the lack of effective drug treatments. Despite this, they have not historically received much attention in terms of investment and research effort, nor do they now. In very recent years, thanks to the involvement of several nonprofit organizations, the chemotherapeutic options have expanded with the introduction of the first combination therapy. The optimal efficacy and safety of nifurtimox-eflornithine combination against second-stage human African trypanosomiasis is an encouraging first step towards simpler and more affordable therapies. Along the same line, I propose that single chemical entities able to modulate more than one target may prove more efficacious and tolerable than the available arsenal of drugs. Herein, I discuss the pros and cons of this approach, together with examples taken from the recent literature. |
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| 10. | Bull Acad Natl Med. 2011 Jan;195(1):181-8.[Mediterranean visceral leishmaniasis]. [Article in French] Marty P, Pomares C, Michel G, Delaunay P, Ferrua B, Rosenthal E.SourceParasitologie-mycologie, CHU l'Archet--Nice Sophia Antipolis, inserm U 895. marty.p@chu-nice.fr AbstractMediterranean visceral leishmaniasis is a parasitic zoonosis due to Leishmania infantum. The dog is the reservoir species and also the main victim. The vector is the female Phlebotomus sand fly. In the southern Mediterranean region the disease is most frequent in children, whereas in Europe, and particularly in France, it is mostly an opportunistic infection associated with immunosuppression. Frequent asymptomatic carriage has been detected in southern Europe. The classic symptom triad consists of fever, pallor and splenomegaly. Biological signs include low cell blood counts (anemia, leukoneutropenia, and thrombocytopenia) and an inflammatory syndrome. Commercial serologic tests such as those based on immunoblotting are very useful. The gold standard for diagnosis is parasite detection in bone marrow or blood. PCR is useful for therapeutic follow-up. Treatment is currently based on liposomal amphotericin B (AmBisome). |
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