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Cytological Characterization of YpsB, a Novel Component of the Bacillus subtilis Divisome

TAVARES, Jose Roberto; SOUZA, Robson F. de; MEIRA, Guilherme Louzada Silva; GUEIROS-FILHO, Frederico J.
Fonte: AMER SOC MICROBIOLOGY Publicador: AMER SOC MICROBIOLOGY
Tipo: Artigo de Revista Científica
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Cell division in bacteria is carried out by an elaborate molecular machine composed of more than a dozen proteins and known as the divisome. Here we describe the characterization of a new divisome protein in Bacillus subtilis called YpsB. Sequence comparisons and phylogentic analysis demonstrated that YpsB is a paralog of the division site selection protein DivIVA. YpsB is present in several gram-positive bacteria and likely originated from the duplication of a DivIVA-like gene in the last common ancestor of bacteria of the orders Bacillales and Lactobacillales. We used green fluorescent protein microscopy to determine that YpsB localizes to the divisome. Similarly to that for DivIVA, the recruitment of YpsB to the divisome requires late division proteins and occurs significantly after Z-ring formation. In contrast to DivIVA, however, YpsB is not retained at the newly formed cell poles after septation. Deletion analysis suggests that the N terminus of YpsB is required to target the protein to the divisome. The high similarity between the N termini of YpsB and DivIVA suggests that the same region is involved in the targeting of DivIVA. YpsB is not essential for septum formation and does not appear to play a role in septum positioning. However...

The iron stimulon of Xylella fastidiosa includes genes for type IV pilus and colicin V-like bacteriocins

ZAINI, Paulo A.; FOGACA, Andrea C.; LUPO, Fernanda G. N.; NAKAYA, Helder I.; VENCIO, Ricardo Z. N.; SILVA, Aline M. da
Fonte: AMER SOC MICROBIOLOGY Publicador: AMER SOC MICROBIOLOGY
Tipo: Artigo de Revista Científica
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Xylella fastidiosa is the etiologic agent of a wide range of plant diseases, including citrus variegated chlorosis (CVC), a major threat to citrus industry. The genomes of several strains of this phytopathogen were completely sequenced, enabling large-scale functional studies. DNA microarrays representing 2,608 (91.6%) coding sequences (CDS) of X. fastidiosa CVC strain 9a5c were used to investigate transcript levels during growth with different iron availabilities. When treated with the iron chelator 2,2`-dipyridyl, 193 CDS were considered up-regulated and 216 were considered down-regulated. Upon incubation with 100 mu M ferric pyrophosphate, 218 and 256 CDS were considered up- and down-regulated, respectively. Differential expression for a subset of 44 CDS was further evaluated by reverse transcription-quantitative PCR. Several CDS involved with regulatory functions, pathogenicity, and cell structure were modulated under both conditions assayed, suggesting that major changes in cell architecture and metabolism occur when X. fastidiosa cells are exposed to extreme variations in iron concentration. Interestingly, the modulated CDS include those related to colicin V-like bacteriocin synthesis and secretion and to functions of pili/fimbriae. We also investigated the contribution of the ferric uptake regulator Fur to the iron stimulon of X. fastidiosa. The promoter regions of the strain 9a5c genome were screened for putative Fur boxes...

Transcriptional Response to Hypoxia in the Aquatic Fungus Blastocladiella emersonii

CAMILO, Cesar M.; GOMES, Suely L.
Fonte: AMER SOC MICROBIOLOGY Publicador: AMER SOC MICROBIOLOGY
Tipo: Artigo de Revista Científica
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Global gene expression analysis was carried out with Blastocladiella emersonii cells subjected to oxygen deprivation (hypoxia) using cDNA microarrays. In experiments of gradual hypoxia (gradual decrease in dissolved oxygen) and direct hypoxia (direct decrease in dissolved oxygen), about 650 differentially expressed genes were observed. A total of 534 genes were affected directly or indirectly by oxygen availability, as they showed recovery to normal expression levels or a tendency to recover when cells were reoxygenated. In addition to modulating many genes with no putative assigned function, B. emersonii cells respond to hypoxia by readjusting the expression levels of genes responsible for energy production and consumption. At least transcriptionally, this fungus seems to favor anaerobic metabolism through the upregulation of genes encoding glycolytic enzymes and lactate dehydrogenase and the downregulation of most genes coding for tricarboxylic acid (TCA) cycle enzymes. Furthermore, genes involved in energy-costly processes, like protein synthesis, amino acid biosynthesis, protein folding, and transport, had their expression profiles predominantly down-regulated during oxygen deprivation, indicating an energy-saving effort. Data also revealed similarities between the transcriptional profiles of cells under hypoxia and under iron(II) deprivation...

Global Gene Expression Analysis during Sporulation of the Aquatic Fungus Blastocladiella emersonii

VIEIRA, Andre L. G.; GOMES, Suely L.
Fonte: AMER SOC MICROBIOLOGY Publicador: AMER SOC MICROBIOLOGY
Tipo: Artigo de Revista Científica
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The Blastocladiella emersonii life cycle presents a number of drastic biochemical and morphological changes, mainly during two cell differentiation stages: germination and sporulation. To investigate the transcriptional changes taking place during the sporulation phase, which culminates with the production of the zoospores, motile cells responsible for the dispersal of the fungus, microarray experiments were performed. Among the 3,773 distinct genes investigated, a total of 1,207 were classified as differentially expressed, relative to time zero of sporulation, at at least one of the time points analyzed. These results indicate that accurate transcriptional control takes place during sporulation, as well as indicating the necessity for distinct molecular functions throughout this differentiation process. The main functional categories overrepresented among upregulated genes were those involving the microtubule, the cytoskeleton, signal transduction involving Ca(2+), and chromosome organization. On the other hand, protein biosynthesis, central carbon metabolism, and protein degradation were the most represented functional categories among downregulated genes. Gene expression changes were also analyzed in cells sporulating in the presence of subinhibitory concentrations of glucose or tryptophan. Data obtained revealed overexpression of microtubule and cytoskeleton transcripts in the presence of glucose...

Experimental Chemotherapy against Trypanosoma cruzi Infection Using Ruthenium Nitric Oxide Donors

SILVA, Jean Jerley N.; PAVANELLI, Wander R.; PEREIRA, Jose Clayston M.; SILVA, Joao S.; FRANCO, Douglas W.
Fonte: AMER SOC MICROBIOLOGY Publicador: AMER SOC MICROBIOLOGY
Tipo: Artigo de Revista Científica
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The ruthenium NO donors of the group trans-[Ru(NO)(NH(3))(4)L](n+), where the ligand (L) is N-heterocyclic H(2)O, SO(3)(2 -), or triethyl phosphite, are able to lyse Trypanosoma cruzi in vitro and in vivo. Using half-maximal (50%) inhibitory concentrations against bloodstream trypomastigotes (IC(50)(try)) and cytotoxicity data on mammalian V-79 cells (IC(50)(V79)), the in vitro therapeutic indices (TIs) (IC(50)(V79)/IC(50)(try)) for these compounds were calculated. Compounds that exhibited an in vitro TI of >= 10 and trypanocidal activity against both epimastigotes and trypomastigotes with an IC(50)(try/epi) of <= 100 mu M were assayed in a mouse model for acute Chagas` disease, using two different routes (intraperitoneal and oral) for drug administration. A dose-effect relationship was observed, and from that, the ideal dose of 400 nmol/kg of body weight for both trans-[Ru(NO)(NH(3))(4)isn](BF(4))(3) (isn, isonicotinamide) and trans-[Ru(NO)(NH3) 4imN](BF4) 3 (imN, imidazole) and median (50%) effective doses (ED50) of 86 and 190 nmol/kg, respectively, were then calculated. Since the 50% lethal doses (LD(50)) for both compounds are higher than 125 mu mol/kg, the in vivo TIs (LD(50)/ED(50)) of the compounds are 1,453 for trans-[Ru(NO)(NH(3))(4)isn](BF(4))(3) and 658 for trans-[Ru(NO)(NH(3))(4)imN](BF(4))(3). Although these compounds exhibit a marked trypanocidal activity and are able to react with cysteine...

RefZ Facilitates the Switch from Medial to Polar Division during Spore Formation in Bacillus subtilis

Wagner-Herman, Jennifer K.; Bernard, Remi; Dunne, Roisin; Bisson Filho, Alexandre W.; Kumar, Krithika; Trang Nguyen; Mulcahy, Lawrence; Koullias, John; Gueiros-Filho, Frederico José; Rudner, David Z.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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During sporulation, Bacillus subtilis redeploys the division protein FtsZ from midcell to the cell poles, ultimately generating an asymmetric septum. Here, we describe a sporulation-induced protein, RefZ, that facilitates the switch from a medial to a polar FtsZ ring placement. The artificial expression of RefZ during vegetative growth converts FtsZ rings into FtsZ spirals, arcs, and foci, leading to filamentation and lysis. Mutations in FtsZ specifically suppress RefZ-dependent division inhibition, suggesting that RefZ may target FtsZ. During sporulation, cells lacking RefZ are delayed in polar FtsZ ring formation, spending more time in the medial and transition stages of FtsZ ring assembly. A RefZ-green fluorescent protein (GFP) fusion localizes in weak polar foci at the onset of sporulation and as a brighter midcell focus at the time of polar division. RefZ has a TetR DNA binding motif, and point mutations in the putative recognition helix disrupt focus formation and abrogate cell division inhibition. Finally, chromatin immunoprecipitation assays identified sites of RefZ enrichment in the origin region and near the terminus. Collectively, these data support a model in which RefZ helps promote the switch from medial to polar division and is guided by the organization of the chromosome. Models in which RefZ acts as an activator of FtsZ ring assembly near the cell poles or as an inhibitor of the transient medial ring at midcell are discussed.; National Institutes of Health; National Institutes of Health [GM086466]; Giovanni ArmeniseHarvard Foundation; Giovanni Armenise-Harvard Foundation; Hellman Family Faculty Fund; Hellman Family Faculty Fund; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [08/58821-1]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [478019/2009-2]; David Rockefeller Center for Latin American Studies faculty grants program; David Rockefeller Center for Latin American Studies faculty grants program

Role of Heme Oxygenase-1 in Polymyxin B-Induced Nephrotoxicity in Rats

Fonseca, Cassiane Dezoti; Watanabe, Mirian; Fernandes Vattimo, Maria de Fatima
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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Polymyxin B (PMB) is a cationic polypeptide antibiotic with activity against multidrug-resistant Gram-negative bacteria. PMB-induced nephrotoxicity consists of direct toxicity to the renal tubules and the release of reactive oxygen species (ROS) with oxidative damage. This study evaluated the nephroprotective effect of heme oxygenase-1 (HO-1) against PMB-induced nephrotoxicity in rats. Adult male Wistar rats, weighing 286 +/- 12 g, were treated intraperitoneally once a day for 5 days with saline, hemin (HO-1 inducer; 10 mg/kg), zinc protoporphyrin (ZnPP) (HO-1 inhibitor; 50 mu mol/kg, administered before PMB on day 5), PMB (4 mg/kg), PMB plus hemin, and PMB plus ZnPP. Renal function (creatinine clearance, Jaffe method), urinary peroxides (ferrous oxidation of xylenol orange version 2 [FOX-2]), urinary thiobarbituric acid-reactive substances (TBARS), renal tissue thiols, catalase activity, and renal tissue histology were analyzed. The results showed that PMB reduced creatinine clearance (P < 0.05), with an increase in urinary peroxides and TBARS. The PMB toxicity caused a reduction in catalase activity and thiols (P < 0.05). Hemin attenuated PMB nephrotoxicity by increasing the catalase antioxidant activity (P < 0.05). The combination of PMB and ZnPP incremented the fractional interstitial area of renal tissue (P < 0.05)...

DivIVA-Mediated Polar Localization of ComN, a Posttranscriptional Regulator of Bacillus subtilis

Santos, Valquiria Tiago dos; Bisson-Filho, Alexandre W.; Gueiros-Filho, Frederico J.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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ComN (YrzD) is a small, 98-amino-acid protein recently shown to be involved in the posttranscriptional control of the late competence comE operon in Bacillus subtilis. We show here that ComN localizes to the division site and cell poles in a DivIVA-dependent fashion. Yeast two-hybrid and glutathione S-transferase pulldown experiments showed that ComN interacts directly with DivIVA. ComN is not essential for the polar assembly of the core competence DNA uptake machinery. Nevertheless, polar localization of ComN should play some role in competence acquisition because delocalization of ComN leads to a small reduction in competence efficiency. We found that ComN promotes the accumulation of its target comE mRNA to septal and polar sites. Thus, we speculate that localized translation of ComE proteins may be required for efficient competence development. Our results underscore the versatility of DivIVA as a promoter of the differentiation of bacterial poles and demonstrate that the repertoire of polarly localized molecules in B. subtilis is broad, including a regulator of gene expression and its target mRNA. Moreover, our findings suggest that mRNA localization may play a role in the subcellular organization of bacteria.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [08/58821-1]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [478019/2009-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)

Genome Sequence of the Bacterioplanktonic, Mixotrophic Vibrio campbellii Strain PEL22A, Isolated in the Abrolhos Bank

Amaral, Gilda Rose S.; Silva, Bruno Sergio de O.; Santos, Eidy O.; Dias, Graciela M.; Lopes, Rubens Mendes; Edwards, Robert A.; Thompson, Cristiane C.; Thompson, Fabiano L.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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Vibrio campbellii PEL22A was isolated from open ocean water in the Abrolhos Bank. The genome of PEL22A consists of 6,788,038 bp (the GC content is 45%). The number of coding sequences (CDS) is 6,359, as determined according to the Rapid Annotation using Subsystem Technology (RAST) server. The number of ribosomal genes is 80, of which 68 are tRNAs and 12 are rRNAs. V. campbellii PEL22A contains genes related to virulence and fitness, including a complete proteorhodopsin cluster, complete type II and III secretion systems, incomplete type I, IV, and VI secretion systems, a hemolysin, and CTX Phi.; CNPq; CNPq; CAPES; CAPES; FAPERJ; FAPERJ; Division of Biological Infrastructure, NSF; Division of Biological Infrastructure, NSF [DBI 0850356]

Streptomyces brevispora sp nov and Streptomyces laculatispora sp nov., actinomycetes isolated from soil

Zucchi, Tiago Domingues; Kim, Byung-yong; Kshetrimayum, Jenileima Devi; Weon, Hang-Yeon; Kwon, Soon-Wo; Goodfellow, Michael
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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The taxonomic positions of two actinomycetes isolated from a hay meadow soil sample were determined using a polyphasic approach. The isolates had chemical and morphological properties typical of streptomycetes and formed a distinct 16S rRNA gene subclade together with the type strain Streptomyces drozdowiczii NRRL B-24297(T). DNA DNA relatedness studies showed that the three strains belonged to different genomic species. The organisms were also distinguished using a combination of phenotypic properties. On the basis of these data it is proposed that the isolates be assigned to the genus Streptomyces as Streptomyces brevispora sp. nov. and Streptomyces laculatispora sp. nov., with BK160(T) (=KACC 21093(T) =NCIMB 14702(T)) and BK166(T) (=KACC 20907(T) =NCIMB 14703(T)) as the respective type strains.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [201066/2009-2]

Streptomyces cocklensis sp nov., a dioxamycin-producing actinomycete

Kim, Byung-Yong; Zucchi, Tiago Domingues; Fiedler, Hans-Peter; Goodfellow, Michael
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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The taxonomic position of a streptomycete isolated from soil collected from Cockle Park Experimental Farm, Northumberland, UK, was determined by using a polyphasic approach. The organism had chemical and morphological features consistent with its classification in the genus Streptomyces. 16S rRNA gene sequence analysis supported classification of the strain in the genus Streptomyces and showed that it formed a distinct phyletic line loosely associated with members of the Streptomyces yeochonensis Glade. It was related most closely to Streptomyces paucisporeus 1413(T) (98.6%16S rRNA gene sequence similarity), but could be distinguished from the latter based on the low level of DNA DNA relatedness (40%). It was readily distinguished from the type strains of all species assigned to the S. yeochonensis clade based on a combination of phenotypic properties. Strain BK168(T) (=KACC 20908(T)=NCIMB 14704(T)) should therefore be classified as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces cocklensis sp. nov. is proposed. The organism produces the antibiotic dioxamycin.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico, UK [201066/2009-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico...

Amycolatopsis thermophila sp nov and Amycolatopsis viridis sp nov., thermophilic actinomycetes isolated from arid soil

Zucchi, Tiago Domingues; Tan, Geok Yuan Annie; Goodfellow, Michael
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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The taxonomic positions of two thermophilic actinomycetes isolated from an arid Australian soil sample were established based on an investigation using a polyphasic taxonomic approach. The organisms had chemical and morphological properties typical of members of the genus Amycolatopsis and formed distinct phyletic lines in the Amycolatopsis methanolica 16S rRNA subclade. The two organisms were distinguished from one another and from the type strains of related species of the genus Amycolatopsis using a range of phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the two isolates be classified in the genus Amycolatopsis as Amycolatopsis thermophila sp. nov. (type strain GY088(T)=NCIMB 14699(T)=NRRL B-24836(T)) and Amycolatopsis viridis sp. nov. (type strain GY115(T)=NCIMB 14700(T)= NRRL B-24837(T)).; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico in the UK [201066/2009-2]

Low Sensitivity of NS1 Protein Tests Evidenced during a Dengue Type 2 Virus Outbreak in Santos, Brazil, in 2010

Felix, Alvina Clara; Romano, Camila Malta; Centrone, Cristiane de Campos; Rodrigues, Celia Lima; Villas-Boas, Lucy; Araújo, Evaldo Stanislau Affonso de; de Matos, Andreia Manso; Carvalho, Karina Inacio; Turchi Martelli, Celina Maria; Kallas, Esper George
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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In 2010, a large outbreak of dengue occurred in Santos, Brazil. The detection of the NS1 antigen was used for diagnosis in addition to the detection of IgG, IgM, and RNA. A large number of NS1 false-negative results were obtained. A total of 379 RNA-positive samples were selected for thorough evaluation. NS1 was reactive in 37.7% of cases. Most of the cases were characterized as a secondary infection by dengue 2 virus. Sequencing of NS1 positive and negative isolates did not reveal any mutation that could justify the diagnostic failure. Use of existing NS1 tests in the Brazilian population may present a low negative predictive value, and they should be used with caution, preferentially after performing a validation with samples freshly obtained during the ongoing epidemic.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2010/12313-5]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)

Streptomyces herbaceus sp nov., Streptomyces incanus sp nov and Streptomyces pratens sp nov., isolated from the soil of a hay meadow

Kim, Byung-Yong; Rong, Xiaoying; Zucchi, Tiago D.; Bonda, Avinash N. V.; Huang, Ying; Goodfellow, Michael
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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The taxonomic positions of three streptomycetes isolated from a soil sample from a hay meadow were determined using a polyphasic approach. The isolates had chemical and morphological properties typical of the genus Streptomyces and, in phylogenetic analyses based on 16S rRNA gene sequences, formed a distinct subclade that was most closely related to the Streptomyces prasinus subclade. DNA-DNA relatedness studies showed that the novel strains belonged to three different genomic species. The novel strains could be distinguished from one another and from the type strains of the species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the novel strains be assigned to the genus Streptomyces as Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., with BK119(T) (=KACC 21001(T) =CGMCC 4.5797(T)), BK128(T) (=KACC 21002(T) =CGMCC 4.5799(T)) and BK138(T) (=KACC 20904(T) =CGMCC 4.5800(T)) as the respective type strains.; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [201066/2009-2]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico; Newcastle University; Newcastle University

Analysis of Transmitted Resistance to Raltegravir and Selective Pressure among HIV-1-Infected Patients on a Failing HAART in Sao Paulo, Brazil

Mantovani, N. P.; Azevedo, R. G.; Rabelato, J. T.; Sanabani, S.; Diaz, R. S.; Komninakis, S. V.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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We studied the presence of primary resistance to raltegravir (RAL), natural polymorphisms, and selection pressure on HIV-1 integrase. We found a high frequency of integrase polymorphisms related to the resistance to RAL and sequence stability. Further studies are needed to determine the importance of these polymorphisms to RAL resistance.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [09/05712-3]

Cross-reactivity of antipneumococcal surface protein C (PspC) antibodies with different strains and evaluation of inhibition of human complement factor H and secretory IgA binding via PspC

Moreno, Adriana T.; Oliveira, Maria Leonor S.; Ho, Paulo L.; Vadesilho, Cintia F. M.; Palma, Giovana M. P.; Ferreira Jr., Jorge M. C.; Ferreira, Daniela M.; Santos, Silvia Regina Cavani Jorge; Martinez, Marina Baquerizo; Miyaji, Eliane N.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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Pneumococcal surface protein C (PspC) is an important candidate for a cost-effective vaccine with broad coverage against pneumococcal diseases. Previous studies have shown that Streptococcus pneumoniae is able to bind to both human factor H (FH), an inhibitor of complement alternative pathway, and human secretory IgA (sIgA) via PspC. PspC was classified into 11 groups based on variations of the gene. In this work, we used three PspC fragments from different groups (PspC3, PspC5, and PspC8) to immunize mice for the production of antibodies. Immunization with PspC3 induced antibodies that recognized the majority of the clinical isolates as analyzed by Western blotting of whole-cell extracts and flow cytometry of intact bacteria, while anti-PspC5 antibodies showed cross-reactivity with the paralogue pneumococcal surface protein A (PspA), and anti-PspC8 antibodies reacted only with the PspC8-expressing strain. Most of the isolates tested showed strong binding to FH and weaker interaction with sIgA. Preincubation with anti-PspC3 and anti-PspC5 IgG led to some inhibition of binding of FH, and preincubation with anti-PspC3 partially inhibited sIgA binding in Western blotting. The analysis of intact bacteria through flow cytometry showed only a small decrease in FH binding after incubation of strain D39 with anti-PspC3 IgG...

HIV-1 Proviral DNA Loads (as Determined by Quantitative PCR) in Patients Subjected to Structured Treatment Interruption after Antiretroviral Therapy Failure

Komninakis, Shirley V.; Santos, Domingos E. M.; Santos, Carlos; Oliveros, Marcia P. R.; Sanabani, Sabri; Diaz, Ricardo S.
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
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The impact of Structured Treatment Interruption (STI) in peripheral blood mononuclear cell (PBMC) proviral reservoirs in 41 highly active antiretroviral therapy (HAART)-treated viremic individuals at baseline and 12 weeks after STI was determined using quantitative PCR (qPCR). Viral load increased 0.7 log(10) and CD4 decreased 97.5 cells/mm(3) after 12 weeks. A total of 28 of the 41 individuals showed an increased proviral load, 19 with a statistically significant increase above 10%. An increase in active viral replication is an important factor in the replenishment of the proviral reservoir even for short time periods.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [03/11781-1]

Amycolatopsis granulosa sp nov., Amycolatopsis ruanii sp nov and Amycolatopsis thermalba sp nov., thermophilic actinomycetes isolated from arid soils

Zucchi, Tiago Domingues; Tan, Geok Yuan Annie; Bonda, Avinash Naga Venkata; Frank, Sarah; Kshetrimayum, Jenileima Devi; Goodfellow, Michael
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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The taxonomic positions of three thermophilic actinomycetes isolated from arid soil samples were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus Amycolatopsis. 16S rRNA gene sequence data supported the classification of the isolates in the genus Amycolatopsis and showed that they formed distinct branches in the Amycolatopsis methanolica subclade. DNA-DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The three isolates were readily distinguished from one another and from the type strains of species classified in the A. methanolica subclade based on a combination of phenotypic properties and by genomic fingerprinting. Consequently, it is proposed that the three isolates be classified in the genus Amycolatopsis as representatives of Amycolatopsis granulosa sp. nov. (type strain GY307(T)=NCIMB 14709(T)=NRRL B-24844(T)), Amycolatopsis ruanii sp. nov. (type strain NMG112(T)=NCIMB 14711(T)=NRRL B-24848(T)) and Amycolatopsis thermalba sp. nov. (type strain SF45(T)=NCIMB 14705(T)=NRRL B-24845(T)).; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico [201066/2009-2]

Evaluation of the genetic diversity of Histoplasma capsulatum var. capsulatum isolates from north-eastern Brazil

Brilhante, Raimunda S. N.; Ribeiro, Joyce F.; Lima, Rita A. C.; Castelo-Branco, Debora S. C. M.; Soares, Rodrigo Martins; Mesquita, Jaco R. L.; Grangeiro, Thalles Barbosa; Camargo, Zoilo P.; Cordeiro, Rossana A.; Rocha, Marcos F. G.; Sidrim, Jose J. C.
Fonte: SOC GENERAL MICROBIOLOGY; READING Publicador: SOC GENERAL MICROBIOLOGY; READING
Tipo: Artigo de Revista Científica
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Since the beginning of the HIV epidemic, there has been a significant increase in the number of histoplasmosis cases in Ceara, a state in north-east Brazil. The lack of epidemiological data on the genotypes circulating in the north-east region shows the importance of more detailed studies on the molecular epidemiology of Histoplasma capsulatum var. capsulatum in this region. Different molecular techniques have been used to better characterize the genetic profile of H. capsulatum var. capsulatum strains. The aim of this study was to analyse the genetic diversity of H. capsulatum var. capsulatum isolates in Fortaleza, the capital of Ceara, through the sequencing of the internal transcribed spacer (ITS)1-5.8S-ITS2 region, and establish the molecular profile of these isolates, along with strains from south-east Brazil, by RAPD analysis, featuring the different clusters in those regions. The isolates were grouped into two clusters. Cluster 1 included strains from the south-east and north-east regions with separation of isolates into three distinct subgroups (subgroups 1a, 1 b and 1 c). Cluster 2 included only samples from north-east Brazil. Sequencing of the ITS1 -5.8S-ITS2 region allowed the detection of two major clades, which showed geographical correlation between them and their subgroups. Therefore...

Molecular Characterization of the Putative Transcription Factor SebA Involved in Virulence in Aspergillus fumigatus

Dinamarco, Taísa Magnani; Almeida, Ricardo Sérgio Couto de; Castro, Patrícia Alves de; Brown, Neil Andrew; Reis, Thaila Fernanda dos; Ramalho, Leandra Naira Zambelli; Savoldi, Marcela; Goldman, Maria Helena de Souza; Goldman, Gustavo Henrique
Fonte: AMER SOC MICROBIOLOGY; WASHINGTON Publicador: AMER SOC MICROBIOLOGY; WASHINGTON
Tipo: Artigo de Revista Científica
Português
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Aspergillus fumigatus is a major opportunistic pathogen and allergen of mammals. Nutrient sensing and acquisition mechanisms, as well as the capability to cope with different stressing conditions, are essential for A. fumigatus virulence and survival in the mammalian host. This study characterized the A. fumigatus SebA transcription factor, which is the putative homologue of the factor encoded by Trichoderma atroviride seb1. The Delta sebA mutant demonstrated reduced growth in the presence of paraquat, hydrogen peroxide, CaCl2, and poor nutritional conditions, while viability associated with sebA was also affected by heat shock exposure. Accordingly, SebA:GFP (SebA:green fluorescent protein) was shown to accumulate in the nucleus upon exposure to oxidative stress and heat shock conditions. In addition, genes involved in either the oxidative stress or heat shock response had reduced transcription in the Delta sebA mutant. The A. fumigatus Delta sebA strain was attenuated in virulence in a murine model of invasive pulmonary aspergillosis. Furthermore, killing of the Delta sebA mutant by murine alveolar macrophages was increased compared to killing of the wild-type strain. A. fumigatus SebA plays a complex role, contributing to several stress tolerance pathways and growth under poor nutritional conditions...