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Molina-Torres C.A.,Hospital Universitario Jose nzalez | Castro-Garza J.,Research Center Biomedica Del Noreste | Ocampo-Candiani J.,Hospital Universitario Jose nzalez | Monot M.,Ecole Polytechnique Federale de Lausanne | And 2 more authors.
Journal of Medical Microbiology | Year: 2010

Continuous subculture has been observed to produce changes in the virulence of microorganisms, e.g. rabies virus, poliovirus and Mycobacterium bovis BCG. The latter has been used as a vaccine for tuberculosis for the last 100 years; however, in some instances its efficacy has been observed to be very low. In order to determine whether similar changes can be produced in Mycobacterium tuberculosis, we selected four isolates, M. tuberculosis H37Rv, a Beijing strain (DR-689), and two more isolates with deletion of the phospholipase C locus (plcA-plcB-plcC), and subjected them to serial culturing on Middlebrook 7H9 medium, with or without ox bile. After 100 passages, we performed RFLP-IS6110 analysis to determine whether genomic changes were produced. We also checked their genomic composition by microarray analysis. Changes in virulence were studied by measuring the cytotoxic effect of parental and subcultured isolates on a THP-1 macrophage monolayer. The most visible change was the change of position of an IS6110 band of ∼1400 bp to ∼1600 bp in the Beijing isolate subcultured in the ox bile medium. Analysis by microarray and PCR confirmation did not reveal any genomic changes. Cytotoxic activity was decreased in the isolates at levels close to that of BCG, and more consistently in those subcultured in the presence of ox bile. © 2010 SGM. Source


Miranda-Velasquez L.,Autonomous University of Nuevo Leon | Oranday-Cardenas A.,Autonomous University of Nuevo Leon | Lozano-Garza H.,Research Center Biomedica Del Noreste | Rivas-Morales C.,Autonomous University of Nuevo Leon | And 2 more authors.
Plant Foods for Human Nutrition | Year: 2010

The aim of this study was to determine the hypocholesterolemic activity of Cnidoscolus chayamansa. In an in vivo model, high-cholesterol diet administered to mice Balb/c induced hypercholesterolemia. Three extracts from Cnidoscolus chayamansa (ethanol, methanol and an aqueous extract) were tested on hypercholesterolemic mice. Active extracts were assessed against the in vitro inhibitory activity of the same three extracts on the HMG-CoA reductase enzyme by using Vero cells. The specific chemical groups present in the phytochemical extracts were also determined. Only the aqueous extract (at either doses employed) showed a significant cholesterol reduction (27.9 and 31.1%, for 50 and 100 mg kg-1, respectively P<0.01). The extract did not inhibit the HMG-CoA reductase enzyme, suggesting that its compounds act at another level in cholesterol metabolism. Reactions to secondary metabolites indicate the presence of alkaloids in the aqueous and ethanol extracts and phenol hydroxyls in the ethanol and methanol extracts. © 2010 Springer Science+Business Media, LLC. Source


Molina-Salinas G.M.,Research Center Biomedica Del Noreste | Said-Fernandez S.,Research Center Biomedica Del Noreste
Natural Product Research | Year: 2013

From the hexane extract of stem bark of Diospyros anisandra was isolated a new plumbagin dimer, epoxide of zeylanone, along with 14 known compounds, including seven naphthoquinones, four triterpenoids and three sesquiterpenoids. The structures were elucidated by the application of IR, UV, MS, 1D-and 2D-NMR spectroscopic analysis and by comparison with literature data. © 2013 Taylor and Francis Group, LLC. Source


Almaguer-Chavez J.A.,Hospital Universitario Jose nzalez | Welsh O.,Hospital Universitario Jose nzalez | Lozano-Garza H.G.,Research Center Biomedica Del Noreste | Said-Fernandez S.,Research Center Biomedica Del Noreste | And 3 more authors.
BMC Infectious Diseases | Year: 2011

Background: Subculturing has been extensively used to attenuate human pathogens. In this work we studied the effect of continuous subculturing of Nocardia brasiliensis HUJEG-1 on virulence in a murine model.Methods: Nocardia brasiliensis HUJEG-1 was subcultured up to 130 times on brain heart infusion over four years. BALB/c mice were inoculated in the right foot pad with the bacteria subcultured 0, 40, 80, 100 and 130 times (T0, T40, T80T100and T130). The induction of resistance was tested by using T130to inoculate a group of mice followed by challenge with T0 12 weeks later. Biopsies were taken from the newly infected foot-pad and immunostained with antibodies against CD4, CD8 and CD14 in order to analyze the in situ immunological changes.Results: When using T40, T80T100and T130as inoculums we observed lesions in 10, 5, 0 and 0 percent of the animals, respectively, at the end of 12 weeks. In contrast, their controls produced mycetoma in 80, 80, 70 and 60% of the inoculated animals. When studying the protection of T130, we observed a partial resistance to the infection. Immunostaining revealed an intense CD4+ lymphocytic and macrophage infiltrate in healing lesions.Conclusions: After 130 in vitro passages of N. brasiliensis HUJEG-1 a severe decrease in its virulence was observed. Immunization of BALB/c mice, with these attenuated cells, produced a state of partial resistance to infection with the non-subcultured isolate. © 2011 Almaguer-Chávez et al; licensee BioMed Central Ltd. Source


Molina-Torres C.A.,Hopital Universitario | Barba-Marines A.,Hopital Universitario | Valles-Guerra O.,Hopital Universitario | Ocampo-Candiani J.,Hopital Universitario | And 4 more authors.
Annals of Clinical Microbiology and Antimicrobials | Year: 2014

Background: Due to the emergency of multidrug-resistant strains of Mycobacterium tuberculosis, is necessary the evaluation of new compounds.Findings: Tedizolid, a novel oxazolidinone, and ACH-702, a new isothiazoloquinolone, were tested against M. tuberculosis infected THP-1 macrophages. These two compounds significantly decreased the number of intracellular mycobacteria at 0.25X, 1X, 4X and 16X the MIC value. The drugs were tested either in nanoparticules or in free solution.Conclusion: Tedizolid and ACH-702 have a good intracellular killing activity comparable to that of rifampin or moxifloxacin. © 2014 Molina-Torres et al.; licensee BioMed Central Ltd. Source

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