64 research outputs found

    Variations in gene organization and DNA uptake signal sequence in the folP region between commensal and pathogenic Neisseria species

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    BACKGROUND: Horizontal gene transfer is an important source of genetic variation among Neisseria species and has contributed to the spread of resistance to penicillin and sulfonamide drugs in the pathogen Neisseria meningitidis. Sulfonamide resistance in Neisseria meningitidis is mediated by altered chromosomal folP genes. At least some folP alleles conferring resistance have been horizontally acquired from other species, presumably from commensal Neisseriae. In this work, the DNA sequence surrounding folP in commensal Neisseria species was determined and compared to corresponding regions in pathogenic Neisseriae, in order to elucidate the potential for inter-species DNA transfer within this region. RESULTS: The upstream region of folP displayed differences in gene order between species, including an insertion of a complete Correia element in Neisseria lactamica and an inversion of a larger genomic segment in Neisseria sicca, Neisseria subflava and Neisseria mucosa. The latter species also had DNA uptake signal sequences (DUS) in this region that were one base different from the DUS in pathogenic Neisseriae. Another interesting finding was evidence of a horizontal transfer event from Neisseria lactamica or Neisseria cinerea that introduced a novel folP allele to the meningococcal population. CONCLUSION: Genetic recombination events immediately upstream of folP and horizontal transfer have resulted in sequence differences in the folP region between the Neisseria species. This variability could be a consequence of the selective pressure on this region exerted by the use of sulfonamide drugs

    Sensitive and specific detection of Trypanosoma cruzi DNA in clinical specimens using a multi-target real-time PCR approach

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    Background: The laboratory diagnosis of Chagas disease is challenging because the usefulness of different diagnostic tests will depend on the stage of the disease. Serology is the preferred method for patients in the chronic phase, whereas PCR can be successfully used to diagnose acute and congenital cases. Here we present data using a combination of three TaqMan PCR assays to detect T. cruzi DNA in clinical specimens. Methods/Principal Findings: Included in the analysis were DNA extracted from 320 EDTA blood specimens, 18 heart tissue specimens, 6 umbilical cord blood specimens, 2 skin tissue specimens and 3 CSF specimens. For the blood specimens both whole blood and buffy coat fraction were analyzed. The specimens were from patients living in the USA, with suspected exposure to T. cruzi through organ transplantation, contact with triatomine bugs or laboratory accidents, and from immunosuppressed patients with suspected Chagas disease reactivation. Real-time PCR was successfully used to diagnose acute and Chagas disease reactivation in 20 patients, including one case of organ-transmitted infection and one congenital case. Analysis of buffy coat fractions of EDTA blood led to faster diagnosis in six of these patients compared to whole blood analysis. The three real-time PCR assays produced identical results for 94% of the specimens. The major reason for discrepant results was variable sensitivity among the assays, but two of the real-time PCR assays also produced four false positive results. Conclusions/Significance: These data strongly indicate that at least two PCR assays with different performances should be combined to increase the accuracy. This evaluation also highlights the benefit of extracting DNA from the blood specimen's buffy coat to increase the sensitivity of PCR analysis.Fil: Qvarnstrom, Yvonne. Centers for Disease Control and Prevention; Estados UnidosFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Veron, Vincent. Centre hospitalier Andrée-Rosemon; Guayana FrancesaFil: Aznar, Christine. Centre hospitalier Andrée-Rosemon; Guayana FrancesaFil: Steurer, Francis. Centers for Disease Control and Prevention; Estados UnidosFil: da Silva, Alexandre J.. Centers for Disease Control and Prevention; Estados Unido

    Acute Chagas Disease in a Returning Traveler

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    Acute Chagas disease is rarely recognized, and the risk for acquiring the disease is undefined in travelers to Central America. We describe a case of acute Chagas disease in a traveler to Costa Rica and highlight the need for increased awareness of this infection in travelers to Chagas-endemic areas

    Cutaneous microsporidiosis in an immunosuppressed patient

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    Microsporidia are a group of obligate intracellular parasites that naturally infect domestic and wild animals. Human microsporidiosis is an increasingly recognized multisystem opportunistic infection. The clinical manifestations are diverse with diarrhea being the most common presenting symptom. We present a 52‐year‐old woman with a history of amyopathic dermatomyositis complicated by interstitial lung disease managed with mycophenolate mofetil and hydroxychloroquine who presented with a 7‐month history of recurrent subcutaneous nodules as well as intermittent diarrhea and chronic sinusitis. A punch biopsy showed superficial and deep lymphocytic and granulomatous dermatitis with focal necrosis. Tissue stains for microorganisms revealed oval 1 to 3 ÎŒm spores within the necrotic areas in multiple tissue stains. Additional studies at the Centers for Disease Control and Prevention confirmed cutaneous microsporidiosis. This case is one of very few confirmed examples of cutaneous microsporidiosis reported in the literature.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155918/1/cup13674_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155918/2/cup13674.pd

    Disseminated Microsporidiosis in an Immunosuppressed Patient

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    We report a case of disseminated microsporidiosis in a patient with multiple myeloma who had received an allogeneic stem cell transplant requiring substantial immunosuppression. The causative organism was identified as Tubulinosema acridophagus, confirming this genus of microsporidia as a novel human pathogen

    Distribution of Parmarion cf. martensi (Pulmonata: Helicarionidae), a New Semi-Slug Pest on Hawai‘i Island, and Its Potential as a Vector for Human Angiostrongyliasis.

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    v. ill. 23 cm.QuarterlyThe semi-slug Parmarion cf. martensi Simroth, 1893, was first discovered on O‘ahu, Hawai‘i, in 1996 and then on the island of Hawai‘i in 2004. This species, which is probably native to Southeast Asia, is abundant in eastern Hawai‘ i Island, reportedly displacing the Cuban slug, Veronicella cubensis (Pfeiffer, 1840), in some areas. A survey in July–August 2005 found P. cf. martensi primarily in the lower Puna area of Hawai‘i Island, with an isolated population in Kailua-Kona (western Hawai‘i Island). It is now established in commercial papaya plantations, and survey participants reported it as a pest of lettuce and papaya in home gardens. Survey respondents considered P. cf. martensi a pest also because of its tendency to climb on structures where it deposits its feces and because of its potential to transmit disease. Individuals of this species were found to carry large numbers of infective third-stage larvae of the nematod

    International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from Chagas disease patients

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    A century after its discovery, Chagas disease, caused by the parasite Trypanosoma cruzi, still represents a major neglected tropical threat. Accurate diagnostics tools as well as surrogate markers of parasitological response to treatment are research priorities in the field. The polymerase chain reaction (PCR) has been proposed as a sensitive laboratory tool for detection of T. cruzi infection and monitoring of parasitological treatment outcome. However, high variation in accuracy and lack of international quality controls has precluded reliable applications in the clinical practice and comparisons of data among cohorts and geographical regions. In an effort towards harmonization of PCR strategies, 26 expert laboratories from 16 countries evaluated their current PCR procedures against sets of control samples, composed by serial dilutions of T.cruzi DNA from culture stocks belonging to different lineages, human blood spiked with parasite cells and blood samples from Chagas disease patients. A high variability in sensitivities and specificities was found among the 48 reported PCR tests. Out of them, four tests with best performance were selected and further evaluated. This study represents a crucial first step towards device of a standardized operative procedure for T. cruzi PCR.Fil: Schijman, Alejandro G. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular (INGEBI-CONICET). Laboratorio de BiologĂ­a Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Bisio, Margarita. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular (INGEBI-CONICET). Laboratorio de BiologĂ­a Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Orellana, Liliana. Universidad de Buenos Aires. Instituto de CĂĄlculo; Argentina.Fil: Sued, Mariela. Universidad de Buenos Aires. Instituto de CĂĄlculo; Argentina.Fil: Duffy, TomĂĄs. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular (INGEBI-CONICET). Laboratorio de BiologĂ­a Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Mejia Jaramillo, Ana M. Universidad de Antioquia. Grupo Chagas; Colombia.Fil: Cura, Carolina. Instituto de Investigaciones en IngenierĂ­a GenĂ©tica y BiologĂ­a Molecular (INGEBI-CONICET). Laboratorio de BiologĂ­a Molecular de la Enfermedad de Chagas (LabMECh); Argentina.Fil: Auter, Frederic. French Blood Services; Francia.Fil: Veron, Vincent. Universidad de ParasitologĂ­a. Laboratorio Hospitalario; Guayana Francesa.Fil: Qvarnstrom, Yvonne. Centers for Disease Control. Department of Parasitic Diseases; Estados Unidos.Fil: Deborggraeve, Stijn. Institute of Tropical Medicine; BĂ©lgica.Fil: Hijar, Gisely. Instituto Nacional de Salud; PerĂș.Fil: Zulantay, InĂ©s. Facultad de Medicina; Chile.Fil: Lucero, RaĂșl Horacio. Universidad Nacional del Nordeste; Argentina.Fil: VelĂĄzquez, Elsa. ANLIS Dr.C.G.MalbrĂĄn. Instituto Nacional de ParasitologĂ­a Dr. Mario Fatala Chaben; Argentina.Fil: Tellez, Tatiana. Universidad Mayor de San Simon. Centro Universitario de Medicina Tropical; Bolivia.Fil: Sanchez Leon, Zunilda. Universidad Nacional de AsunciĂłn. Instituto de Investigaciones en Ciencias de la Salud; Paraguay.Fil: GalvĂŁo, Lucia. Faculdade de FarmĂĄcia; Brasil.Fil: Nolder, Debbie. Hospital for Tropical Diseases. London School of Tropical Medicine and Hygiene Department of Clinical Parasitology; Reino Unido.Fil: Monje Rumi, MarĂ­a. Universidad Nacional de Salta. Laboratorio de PatologĂ­a Experimental; Argentina.Fil: Levi, JosĂ© E. Hospital Sirio LibanĂȘs. Blood Bank; Brasil.Fil: Ramirez, Juan D. Universidad de los Andes. Centro de Investigaciones en MicrobiologĂ­a y ParasitologĂ­a Tropical; Colombia.Fil: Zorrilla, Pilar. Instituto Pasteur; Uruguay.Fil: Flores, MarĂ­a. Instituto de Salud Carlos III. Centro de Mahahonda; España.Fil: Jercic, Maria I. Instituto Nacional De Salud. SecciĂłn ParasitologĂ­a; Chile.Fil: Crisante, Gladys. Universidad de los Andes. Centro de Investigaciones ParasitolĂłgicas J.F. Torrealba; Venezuela.Fil: Añez, NĂ©stor. Universidad de los Andes. Centro de Investigaciones ParasitolĂłgicas J.F. Torrealba; Venezuela.Fil: De Castro, Ana M. Universidade Federal de GoiĂĄs. Instituto de Patologia Tropical e SaĂșde PĂșblica (IPTSP); Brasil.Fil: Gonzalez, Clara I. Universidad Industrial de Santander. Grupo de InmunologĂ­a y EpidemiologĂ­a Molecular (GIEM); Colombia.Fil: Acosta Viana, Karla. Universidad AutĂłnoma de YucatĂĄn. Departamento de Biomedicina de Enfermedades Infecciosas y Parasitarias Laboratorio de BiologĂ­a Celular; MĂ©xico.Fil: Yachelini, Pedro. Universidad CatĂłlica de Santiago del Estero. Instituto de Biomedicina; Argentina.Fil: Torrico, Faustino. Universidad Mayor de San Simon. Centro Universitario de Medicina Tropical; Bolivia.Fil: Robello, Carlos. Instituto Pasteur; Uruguay.Fil: Diosque, Patricio. Universidad Nacional de Salta. Laboratorio de PatologĂ­a Experimental; Argentina.Fil: Triana Chavez, Omar. Universidad de Antioquia. Grupo Chagas; Colombia.Fil: Aznar, Christine. Universidad de ParasitologĂ­a. Laboratorio Hospitalario; Guayana Francesa.Fil: Russomando, Graciela. Universidad Nacional de AsunciĂłn. Instituto de Investigaciones en Ciencias de la Salud; Paraguay.Fil: BĂŒscher, Philippe. Institute of Tropical Medicine; BĂ©lgica.Fil: Assal, Azzedine. French Blood Services; Francia.Fil: Guhl, Felipe. Universidad de los Andes. Centro de Investigaciones en MicrobiologĂ­a y ParasitologĂ­a Tropical; Colombia.Fil: Sosa Estani, Sergio. ANLIS Dr.C.G.MalbrĂĄn. Centro Nacional de DiagnĂłstico e InvestigaciĂłn en Endemo-Epidemias; Argentina.Fil: DaSilva, Alexandre. Centers for Disease Control. Department of Parasitic Diseases; Estados Unidos.Fil: Britto, Constança. Instituto Oswaldo Cruz/FIOCRUZ. LaboratĂłrio de Biologia Molecular e Doenças EndĂȘmicas; Brasil.Fil: Luquetti, Alejandro. LaboratĂłrio de Pesquisa de Doença de Chagas; Brasil.Fil: Ladzins, Janis. World Health Organization (WHO). Special Programme for Research and Training in Tropical Diseases (TDR); Suiza

    International Study to Evaluate PCR Methods for Detection of Trypanosoma cruzi DNA in Blood Samples from Chagas Disease Patients

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    A century after its discovery, Chagas disease, caused by the parasite Trypanosoma cruzi, still represents a major neglected tropical threat. Accurate diagnostics tools as well as surrogate markers of parasitological response to treatment are research priorities in the field. The polymerase chain reaction (PCR) has been proposed as a sensitive laboratory tool for detection of T. cruzi infection and monitoring of parasitological treatment outcome. However, high variation in accuracy and lack of international quality controls has precluded reliable applications in the clinical practice and comparisons of data among cohorts and geographical regions. In an effort towards harmonization of PCR strategies, 26 expert laboratories from 16 countries evaluated their current PCR procedures against sets of control samples, composed by serial dilutions of T.cruzi DNA from culture stocks belonging to different lineages, human blood spiked with parasite cells and blood samples from Chagas disease patients. A high variability in sensitivities and specificities was found among the 48 reported PCR tests. Out of them, four tests with best performance were selected and further evaluated. This study represents a crucial first step towards device of a standardized operative procedure for T. cruzi PCR

    Variations in gene organization and DNA uptake signal sequence in the region between commensal and pathogenic species-0

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    <p><b>Copyright information:</b></p><p>Taken from "Variations in gene organization and DNA uptake signal sequence in the region between commensal and pathogenic species"</p><p>BMC Microbiology 2006;6():11-11.</p><p>Published online 17 Feb 2006</p><p>PMCID:PMC1431543.</p><p>Copyright © 2006 Qvarnstrom and Swedberg; licensee BioMed Central Ltd.</p>other species. Open reading frames are visualized as colored block arrows (the tip of each arrow symbolizing the stop codon) and labeled with their designations according to the text. Non-coding regions are visualized as solid lines. The gene and the Correia element in were only partially sequenced. The symbol // means that 13 kb sequence separating from has been omitted in the figure. The intergenic regions are defined by dotted vertical lines and designated TC (-), DM (-), MF (-) and FU (-upstream), respectively
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