1,721,013 research outputs found
In vitro anti-tuberculosis activity of azole drugs against Mycobacterium tuberculosis clinical isolates
Full text linkBackground: Latent tuberculosis has been associated with the persistence of dormant Mycobacterium tuberculosis in the organism of infected individuals, who are reservoirs of the bacilli and the source for spreading the disease in the community. New active anti-TB drugs exerting their metabolic action at different stages and on latent/dormant bacilli are urgently required to avoid endogenous reactivations and to be part of treatments of multi- and extensively-drug resistant tuberculosis (M/XDR-TB). It was previously reported that azole drugs are active against M. tuberculosis. For that reason, the aims of this study were to determine the in vitro activity of azole drugs, imidazole (clotrimazole, CLO and econazole, ECO) and nitroimidazole (metronidazole, MZ and ipronidazole, IPZ), against a collection of MDR M. tuberculosis clinical isolates; and to analyze their potential use in both the LTB and the active forms of M/XDR-TB treatments.
Methods: A total of 55 MDR M. tuberculosis isolates and H37Rv were included. MZ and IPZ activity against M. tuberculosis isolates were tested using anaerobic culture conditions.
The activity of ECO and CLO was measured by the minimal inhibitory concentration (MIC) using a microdilution colorimetric method.Inst. de BiotecnologíaFil: Imperiale, Belen Rocio. Hospital Dr. Antonio A. Cetrángolo. Laboratorio de Referencia del Programa de Control de la Tuberculosis de la provincia de Buenos Aires; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Morcillo, Nora. Hospital Dr. Antonio A. Cetrángolo. Laboratorio de Referencia del Programa de Control de la Tuberculosis de la provincia de Buenos Aires; Argentin
Comparative study of two deleted Mycobacterium bovis strains in experimental animal models
No full textPosterIntroduction: Bovine tuberculosis (bTB) constitutes a problem for livestock and Public Health due to its negative impact on farms and its zoonotic nature. In Argentina, the application of the National Control and Eradication Program reduced bTB prevalence. Due to its complexity, the disease continues to be a challenge. Vaccination, as a complementary control tool, could reduce its impact on cattle. Currently, there is no commercial vaccine approved for its use in bovines. Two attenuated strains, M. bovis Δmce2 and M. bovis Δmce2-phoP1,2 induced protection against a virulent Mycobacterium bovis (M. bovis) strain, during a challenge in cattle3 and the murine model4, respectively. The objective of this work was to evaluate the virulence and safety of M. bovis Δmce2 and M. bovis Δmce2-phoP in mice and guinea pigs, to compare how these two strains behave in both animal models.Instituto de BiotecnologíaFil: Ferrara Muñiz, Ximena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Ferrara Muñiz, Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blanco, Federico Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Blanco, Federico Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia, Elizabeth Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Garcia, Elizabeth Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Delgado, Fernando Oscar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria; ArgentinaFil: Marfil, Maria Jimena. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Cátedra de Enfermedades Infecciosas; ArgentinaFil: Zumarraga, Martin Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Zumarraga, Martin Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cataldi, Angel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Eirin, Maria Emilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Eirin, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Preparation of a working seed lot of BCG and quality control by PCR genotyping
Full text linkThe bacillus Calmette-Guérin (BCG) was obtained in 1920 after successive passages leading to the attenuation of a Mycobacterium bovis strain. For the following 40 years, BCG had been replicated, resulting in substrains with genotypic and phenotypic differences. Several genomic studies have compared two BCG strains, M. bovis and Mycobacterium tuberculosis, and observed that deleted regions in the different strains could be related to differences in antigenic properties. In this work, a working seed lot was obtained from a lyophilized secondary seed lot from the BCG Pasteur strain 1173 P2 and genetically characterized. The genome was analyzed by PCR directed to five regions (RD1, RD2, RD14, RD15, DU2), using the seed lot and different available strains as templates. No genetic differences were found in the fragments studied as compared to the Pasteur strain. A total of 20 passages were carried out and no differences were found in the size of the fragments amplified by PCR. In conclusion, this method allows to control a working seed lot genotypically and to assess the stability of the BCG genome.El bacilo de Calmette-Guérin (BCG) se obtuvo en 1920, después de sucesivos pasajes que llevaron a la atenuación de una cepa de Mycobacterium bovis. A lo largo de los 40 años subsiguientes la cepa BCG fue replicada y surgieron subcepas con diferencias fenotípicas y genotípicas. Se realizaron varios estudios de comparación genómica de diferentes cepas de BCG, M. bovis y Mycobacterium tuberculosis, y se observó que las deleciones de regiones en las diferentes cepas podrían estar relacionadas con diferencias en las propiedades antigénicas. En este trabajo se describe la preparación y caracterización genética de un lote semilla de trabajo obtenido a partir de un lote semilla secundaria liofilizado de la cepa BCG Pasteur 1173 P2. Se analizaron por PCR cinco regiones (RD1, RD2, RD14, RD15, DU2) en el lote semilla de trabajo utilizando como control las diferentes cepas disponibles. No se hallaron diferencias genéticas en los fragmentos estudiados al comparar el lote semilla de trabajo con la cepa BCG Pasteur 1173 P2. Asimismo, se efectuaron hasta 20 pasajes y no se encontraron diferencias en el tamaño de los fragmentos amplificados por PCR. En conclusión, se ha puesto a punto un método que permite controlar el genotipo de un lote semilla de trabajo y evaluar la estabilidad del genoma del BCG.Instituto de BiotecnologíaFil: Trovero, A. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Argüelles, Claudia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentin
Replication and transmission features of two experimental vaccine candidates against bovine tuberculosis subcutaneously administrated in a murine model
No full textCattle vaccination is an attractive approach in compliance with control and eradication programs against Bovine Tuberculosis (bTB). Today, there is no anti bTB vaccine licensed. Two vaccine candidates, MbΔmce2 and MbΔmce2-phoP previously designed were evaluated in BALB/c mice, including the parental M. bovis NCTC10772 and a M. bovis hypervirulent Mb04-303 strains as controls. Sentinel mice (non-inoculated) cohoused with subcutaneous inoculated mice. Persistence, visible tuberculosis lesions (VTL) in lungs and spleens and bacillary load were investigated subcutaneously delivered at 60 and 90 days after inoculation (dpi) as well as their potential transmission to naïve mice.
While a 100% survival was observed at 90 dpi without VTL in all groups, transmission was not evidenced in the sentinels mice. Vaccine candidates and control strains were isolated from the spleen of all inoculated mice, while Mb04-303 was isolated from the lungs of one inoculated mouse. Vaccine candidate's attenuation considering survival, lung bacillary load and VTL was confirmed, administrated by the subcutaneous route. Future experiments are necessary to demonstrate whether the persistence of both mutants in the spleen, with low CFU, remains over time to increase the potential increasing risk of dissemination to organs and subsequent transmission to other animals by airborne or other routes.Instituto de BiotecnologíaFil: Ferrara Muñiz, Ximena. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Ferrara Muñiz, Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia, Elizabeth Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Garcia, Elizabeth Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blanco, Federico Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Blanco, Federico Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bigi, Fabiana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Bigi, Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zumarraga, Martin Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Zumarraga, Martin Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cataldi, Angel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Eirin, Maria Emilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Eirin, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
The role of glucose in the pathology of EHEC O157: H7
Full text linkThe pathogen enterohemorrhagic Escherichia coli (EHEC) O157: H7 is responsible for hemorrhagic
colitis and hemolytic uremic syndrome in humans [1]. During the colonization process in the
gastrointestinal tract, EHEC needs to adapt to changes in nutrient availability [2]. The objective of this
study was to evaluate the influence of glucose on physiology and processes involved in the pathogenesis
of EHEC O157: H7 in order to improve our understanding of the mechanisms controlling EHEC growth
and survival in the bovine gut.
In this study we first analyzed the growth rate of EHEC O157: H7 Rafaela II clade 8, a strain isolated
from a bovine in Argentina, grown in the medium DMEM supplemented with either 4.5% glucose (Highglucose - DHG) or 1% glucose (Low-glucose - DLG). In addition, we assessed the bacterial adhesion
capacity and actin pedestal formation induced by EHEC [3] by performing infection assays. For this
purpose, Caco-2 epithelial cells were exposed for 5 h with Rafaela II grown with the different
concentrations of glucose. Subsequently, the samples were fixed (paraformaldehyde 4%) and
permeabilized (triton); actin and nucleic acids (DNA) were stained with rhodamine-phalloidin and TOPRO-3, respectively. Bacterial adhesion capacity and pedestal formation of cells were evaluated using a
Leica TCS SP5 laser scanning confocal microscope (MC). Each Image was acquired by monitoring a
single focal plane over time (xyt scanning mode) using a 40X/1.25 oil objective lens and 543nm HeNe
and 633 nm HeNe lasers. The frequency and resolution for acquiring images were set at 200 Hz and 1,024
x 1,024 pixels, while maintaining the same settings for laser powers, gain, and offset.Instituto de BiotecnologíaFil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Marques Da Silva, Wanderson. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Taibo, Catalina Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Laboratorio Integral de Microscopía; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sabio Y Garcia, Julia Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigación en Ciencias Veterinarias y Agronómicas. Laboratorio Integral de Microscopía; ArgentinaFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Larzabal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cataldi, Angel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Bovine tuberculosis in domestic pigs: Genotyping and distribution of isolates in Argentina
No full textBovine tuberculosis is caused by Mycobacterium bovis and affects primarily cattle, among many other mammal species. In this study, 250 isolates of M. bovis collected from pigs slaughtered in Argentina were typed by spoligotyping. Over half of the isolates (66%) grouped into two spoligotypes.
Moreover, SB0140 was the most frequent spoligotype detected in the three performed samplings. In addition, 195 isolates were typed through variable number of tandem repeats (VNTR) by selecting 7 loci (MIRU 16–26–31 and ETR A–B–C–D). The relationship among the patterns was performed using a goeBURST algorithm and the main clonal complexes grouped 110 isolates (56%). Although pigs shared genotypes with cattle (n = 21), some patterns were detected only in pigs (n = 14). These findings suggest the pig as a source of M. bovis infection to cattle.Instituto de BiotecnologíaFil: Barandiaran, Soledad. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Martinez Vivot, Marcela. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Pérez, Andrés M. University of Minnesota. College of Veterinary Medicine; Estados UnidosFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Zumarraga, Martin Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentin
Secretion systems of pathogenic escherichia coli
No full textProtein secretion plays a central role in modulating the interactions of
bacteria with their environments. Bacterial ribosomes synthesize up to 8000 different proteins. Almost half of these become integrated in membranes and are secreted to the periplasm or to the external milieu. Many bacterial processes , such as DNA replication, motility, transport, antibiotic resistance, scavenging of chemicals, and pathogenesis, depend on protein secretion. Thereby, evolutionarily unrelated protein nanomachines have been developed, which allow exported proteins to cross the Gram-negative membranes. Bacterial proteins can be exported directly from the cytoplasm out of the cell by a one-step (cytoplasm to extracellular milieu), including the type I secretion system (T1SS), T3SS, T4SS, and T6SS, or two-step (periplasm translocation step),
including the T2SS and T5SS, while the T4SS can use either the one- or two-step
mechanism. The T3SS, T5SS, and T6SS are the more common secretion systems in Escherichia coli and most of the secreted substrates are virulence factors related to pathogenic E. coli . In this chapter, we will describe the main characteristic of these last three secretion systems.Inst. de BiotecnologíaFil: Navarro-García, Fernando. Instituto Politécnico Nacional. Centro de Investigación y de Estudios
Avanzados.Departamento de Biología Celular; MéxicoFil: Ruiz-Perez, Fernando. University of Virginia School of Medicine. Department of Pediatrics; Estados UnidosFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentin
Novel Effector Protein EspY3 of Type III Secretion System from Enterohemorrhagic Escherichia coli Is Localized in Actin Pedestals
Full text linkEnterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) are attaching and effacing (A/E) pathogens, which translocate effector proteins to intestinal enterocytes through a type III secretion system (T3SS). T3SS and most of its effector proteins are encoded in a pathogenicity island called LEE. Recently, new effectors have been located outside the LEE. This study aimed to characterize EspY3, a novel non-LEE encoded T3SS effector of EHEC. EspY3 shares homology with SopD and PipB2 effector proteins of Salmonella’s T3SS-1 and T3SS-2, respectively. The presence of recombinant EspY3 in the supernatant samples demonstrated that EspY3 was secreted by the T3SS of EHEC and EPEC. Through infection assays, we demonstrated the translocation of EspY3 into Caco-2 cells by T3SS of EPEC. The subcellular localization of EspY3 was determined in the pedestal region, where its presence generates a significant increase in the size of the pedestals area. The EspY3 effector induced the elongation of polymerized actin pedestals in infected Caco-2 by EPEC. This study confirmed that EspY3 is part of the repertoire of T3SS effectors of EHEC O157:H7, and that it participates in modeling cellular actin during the infectionInstituto de BiotecnologíaFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Riviere, Nahuel Agustín. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentin
The intranasal vaccination of pregnant dams with Intimin and EspBconfers protection in neonatal mice from Escherichia coli (EHEC)O157:H7 infection
No full textEnterohemorrhagic Escherichia coli (EHEC) O157:H7 is responsible for intestinal disease and hemolytic uremic syndrome (HUS), a serious systemic complication which particularly affects children. In this study, we evaluated whether passive immunization protects from EHEC O157:H7 colonization and renal damage, by using a weaned BALB/c mouse model of infection. Recombinant proteins EspB and the carboxyl-terminal fragment of 280 amino acids of γ-intimin (γ-Int C280) were used in combination with a macrophage-activating lipopeptide-2 (MALP) adjuvant to immunize pregnant mice by the intranasal route. Neonatal mice were allowed to suckle vaccinated or sham-vaccinated dams until weaning when they were challenged by the oral route with a suspension of an E. coli O157:H7 Stx2+ strain. The excretion of the inoculated strain was followed for 72 h. All vaccinated dams exhibited elevated serum IgG response against both γ-Int C280 and EspB. Passive immunization of newborn mice resulted in a significant increase in serum IgG titers against γ-Int C280 and a slight increase in EspB-specific antibodies. The neonates from vaccinated dams showed a significant reduction in EHEC O157:H7 colonization 48 h post challenge. In addition, the level of plasma urea concentration, a marker of renal failure, was significantly higher in offsprings of sham-vaccinated mice. In conclusion, vaccination of pregnant dams with γ-Int C280 and EspB could reduce colonization and systemic toxicity of EHEC O157:H7 in their suckling offsprings.Fil: Rabinovitz, Bettina Carol. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Vilte, Daniel Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; ArgentinaFil: Mercado, Elsa Cristina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentin
Human and Veterinary Vaccines against Pathogenic Escherichia coli
Full text linkPathogenic Escherichia coli constitute an important current problem of public health and animal production. Efforts have been made to fight the infections caused by these bacteria, and in this chapter, we present the progress made up to date in the vaccines generated for this purpose. Different vaccines have been tested against the pathotypes responsible for human diseases such as diarrhea and urinary infections. Also, the poultry market has deserved the effort of the researchers to obtain a product that fights the E. coli strains that cause diseases in them. Finally, advances are also presented for the zoonotic enterohemorrhagic E. coli (EHEC), which are a different problem due to their low importance as a disease factor in cattle, but they are a very important pathogen in humans. In several of these fields, authorized products have been developed and are currently being marketed.Fil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Vilte, Daniel Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentin
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