16 research outputs found

    Phytosociological survey of weed plants in soybean culture in the Gurguéia Valley

    Get PDF
    Phytosociology is a set of ecological assessment methods that aim to provide a view of plant species distributions within a plant assemblage. The objective of the current study was to identify and quantify the plants designated as weeds in a glyphosate-resistant soybean crop, using a phytosociological survey of a conventional planting system on the Fazenda Agrosantos (09°27’4124.4” S and 45º01’00.4” O), Vale do Gurguéia, Monte Alegre municipality Piauí state, Brazil. The site lies at a mean altitude of 652 m. Field collections were made 15 days after initial soya planting. For sampling, a 0.40 x 0.40 m quadrat was used, thrown randomly twenty times within the experimental area. Weeds were identified and quantified using the sum of the samples obtained from the quadrat samples. Plants that lay within the quadrat were identified, counted and collected for identification, which was carried out by comparison with specialist bibliographies and weed identification manuals. Evaluated variables were: frequency, density, abundance, relative frequency, relative density, relative abundance and species importance value index. In the soybean cultivation area, 60% of the sampled species were Eudicotyledons, and a total of 8 botanical families and 10 weed species were identified. The species Cenchrus echinatus, Ipomoea asarifolia (Desr.) Roem. & Schult, Amaranthus retroflexus L. and Zea mays L showed the highest values for the analyzed variables, and should therefore be of special attention to soybean producers in the region of Vale da Gurguéia, Piauí, Brazil

    Novel Genetic Polymorphisms That Further Delineate the Phylogeny of the Mycobacterium tuberculosis Complex

    No full text
    In a previous report, we described a PCR protocol for the differentiation of the various species of the Mycobacterium tuberculosis complex (MTC) on the basis of genomic deletions (R. C. Huard, L. C. de Oliveira Lazzarini, W. R. Butler, D. van Soolingen, and J. L. Ho, J. Clin. Microbiol. 41:1637-1650, 2003). That report also provided a broad cross-comparison of several previously identified, phylogenetically relevant, long-sequence and single-nucleotide polymorphisms (LSPs and SNPs, respectively). In the present companion report, we expand upon the previous work (i) by continuing the evaluation of known MTC phylogenetic markers in a larger collection of tubercle bacilli (n = 125), (ii) by evaluating additional recently reported MTC species-specific and interspecific polymorphisms, and (iii) by describing the identification and distribution of a number of novel LSPs and SNPs. Notably, new genomic deletions were found in various Mycobacterium tuberculosis strains, new species-specific SNPs were identified for “Mycobacterium canettii,” Mycobacterium microti, and Mycobacterium pinnipedii, and, for the first time, intraspecific single-nucleotide DNA differences were discovered for the dassie bacillus, the oryx bacillus, and the two Mycobacterium africanum subtype I variants. Surprisingly, coincident polymorphisms linked one M. africanum subtype I genotype with the dassie bacillus and M. microti with M. pinnipedii, thereby suggesting closer evolutionary ties within each pair of species than had been previously thought. Overall, the presented data add to the genetic definitions of several MTC organisms as well as fine-tune current models for the evolutionary history of the MTC

    RDRio Mycobacterium tuberculosis Infection Is Associated with a Higher Frequency of Cavitary Pulmonary Disease▿

    No full text
    Molecular genotyping has shown Mycobacterium tuberculosis lineages to be geographically restricted and associated with distinct ethnic populations. Whether tuberculosis (TB) caused by some M. tuberculosis lineages can present with a differential clinical spectrum is controversial because of very limited clinical data. We recently reported on the discovery of RDRio M. tuberculosis, a Latin American-Mediterranean sublineage that is the predominant cause of TB in Rio de Janeiro, Brazil. To investigate the clinical attributes of TB caused by RDRio strains, we studied a cohort of TB cases from Belo Horizonte, Brazil, in which clinical information recorded on a standardized questionnaire was collected at the time of microbiological testing. These patients were referred for culture and drug susceptibility testing because of the clinical suspicion of “complicated” TB, as demonstrated by high rates of multidrug resistance (12%) and cavitary TB (80%). We performed spoligotyping and RDRio genotyping on the M. tuberculosis strains and analyzed the clinical data from these patients. RDRio M. tuberculosis accounted for 37% of the total TB burden. Multivariate analysis found a significant association between TB caused by RDRio strains and pulmonary cavitation and residence in Belo Horizonte. Since cavitary TB is associated with higher sputum bacillary load, our findings support the hypothesis that RDRio M. tuberculosis is associated with a more “severe” disease as a strategy to increase transmission. Future studies are needed to confirm these observations and to better define the contribution of RDRio M. tuberculosis to the global TB epidemic

    The Mycobacterium tuberculosis Complex-Restricted Gene cfp32 Encodes an Expressed Protein That Is Detectable in Tuberculosis Patients and Is Positively Correlated with Pulmonary Interleukin-10

    No full text
    Human tuberculosis (TB) is caused by the bacillus Mycobacterium tuberculosis, a subspecies of the M. tuberculosis complex (MTC) of mycobacteria. Postgenomic dissection of the M. tuberculosis proteome is ongoing and critical to furthering our understanding of factors mediating M. tuberculosis pathobiology. Towards this end, a 32-kDa putative glyoxalase in the culture filtrate (CF) of growing M. tuberculosis (originally annotated as Rv0577 and hereafter designated CFP32) was identified, cloned, and characterized. The cfp32 gene is MTC restricted, and the gene product is expressed ex vivo as determined by the respective Southern and Western blot testing of an assortment of mycobacteria. Moreover, the cfp32 gene sequence is conserved within the MTC, as no polymorphisms were found in the tested cfp32 PCR products upon sequence analysis. Western blotting of M. tuberculosis subcellular fractions localized CFP32 predominantly to the CF and cytosolic compartments. Data to support the in vivo expression of CFP32 were provided by the serum recognition of recombinant CFP32 in 32% of TB patients by enzyme-linked immunosorbent assay (ELISA) as well as the direct detection of CFP32 by ELISA in the induced sputum samples from 56% of pulmonary TB patients. Of greatest interest was the observation that, per sample, sputum CFP32 levels (a potential indicator of increasing bacterial burden) correlated with levels of expression in sputum of interleukin-10 (an immunosuppressive cytokine and a putative contributing factor to disease progression) but not levels of gamma interferon (a key cytokine in the protective immune response in TB), as measured by ELISA. Combined, these data suggest that CFP32 serves a necessary biological function(s) in tubercle bacilli and may contribute to the M. tuberculosis pathogenic mechanism. Overall, CFP32 is an attractive target for drug and vaccine design as well as new diagnostic strategies

    Down-Modulation of Lung Immune Responses by Interleukin-10 and Transforming Growth Factor β (TGF-β) and Analysis of TGF-β Receptors I and II in Active Tuberculosis

    No full text
    Immune factors influencing progression to active tuberculosis (TB) remain poorly defined. In this study, we investigated the expression of immunoregulatory cytokines and receptors by using lung bronchoalveolar lavage cells obtained from patients with pulmonary TB, patients with other lung diseases (OLD patients), and healthy volunteers (VOL) by using reverse transcriptase PCR, a transforming growth factor β (TGF-β) bioactivity assay, and an enzyme immunoassay. TB patients were significantly more likely than OLD patients to coexpress TGF-β receptor I (RI) and RII mRNA, as well as interleukin-10 (IL-10) mRNA (thereby indicating the state of active gene transcription in the alveolar cells at harvest). In contrast, gamma interferon (IFN-γ) and IL-2 mRNA was seen in both TB and OLD patients. Likewise, significantly elevated pulmonary steady-state protein levels of IL-10, IFN-γ, and bioactive TGF-β were found in TB patients versus those in OLD patients and VOL. These data suggest that the combined production of the immunosuppressants IL-10 and TGF-β, as well as coexpression of TGF-β RI and RII (required for cellular response to TGF-β), may act to down-modulate host anti-Mycobacterium tuberculosis immunity and thereby allow uncontrolled bacterial replication and overt disease. Delineating the underlying mechanisms of M. tuberculosis-triggered expression of these immune elements may provide a molecular-level understanding of TB immunopathogenesis

    Mycobacterium tuberculosis of the RDRio Genotype Is the Predominant Cause of Tuberculosis and Associated with Multidrug Resistance in Porto Alegre City, South Brazil

    No full text
    Made available in DSpace on 2015-08-19T13:49:35Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) harrison_gomes2_etal_IOC_2013.pdf: 160438 bytes, checksum: eb812b0c3b31487bdc9aa59291b52025 (MD5) Previous issue date: 2013Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Universidade Federal do Rio de Janeiro. Unidade de Pesquisa em Tuberculose. Rio de Janeiro, RJ, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil.Hospital Sanatório Partenon (HSP), Porto Alegre, RS, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Hospital Sanatório Partenon (HSP), Porto Alegre, RS, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Hospital Sanatório Partenon (HSP), Porto Alegre, RS, Brasil.Universidade Federal do Rio Grande do Sul (UFRGS). Porto Alegre, RS, Brasil.Fundação Universidade de Rio Grande. Rio Grande, RS, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular Aplicada a Micobactérias. Rio de Janeiro, RJ, Brasil.Fundação Estadual de Produção e Pesquisa em Saúde (FEPPS). Porto Alegre, RS, Brasil / Universidade Luterana do Brazil (ULBRA/RS). Porto Alegre, RS, Brasil.Spoligotyping has shown Mycobacterium tuberculosis strains to be composed of different lineages, and some of them are not just geographically restricted but also affect specific ethnic populations and are associated with outbreaks and drug resistance. We recently described a particular subtype within the Latin American-Mediterranean (LAM) family, called RDRio, widespread in Brazil. Moreover, recent data also indicate that RDRio is present in many countries on all continents and is associated with cavitary disease and multidrug resistance (MDR). To further explore the relationship between RDRio and MDR, we conducted a study in a tuberculosis (TB) reference center responsible for the care of MDR patients in Rio Grande do Sul, the southernmost Brazilian state. From a collection of 237 clinical isolates, RDRio alone was responsible for one-half of all MDR cases, including one large group composed of strains with identical IS6110-restriction fragment length polymorphism (RFLP) and having the LAM5 signature. We additionally had complete data records for 96 patients and could make comparisons between the presence and absence of RDRio. No difference in clinical, radiological or laboratory features was observed, but a significantly greater number of cases with MDR were described in patients infected with an RDRio strain (P 0.0015). Altogether, RDRio was responsible for 38% of all TB cases. These data support and confirmed previous findings that RDRio is the main agent responsible for TB in Brazil and is associated with drug resistance. Considering that RDRio is a globally distributed genotype, such findings raise concern about the increase in MDR in certain human populations
    corecore