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1.
N Engl J Med ; 372(2): 113-23, 2015 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-25365753

RESUMO

BACKGROUND: In light of the increasing rate of dengue infections throughout the world despite vector-control measures, several dengue vaccine candidates are in development. METHODS: In a phase 3 efficacy trial of a tetravalent dengue vaccine in five Latin American countries where dengue is endemic, we randomly assigned healthy children between the ages of 9 and 16 years in a 2:1 ratio to receive three injections of recombinant, live, attenuated, tetravalent dengue vaccine (CYD-TDV) or placebo at months 0, 6, and 12 under blinded conditions. The children were then followed for 25 months. The primary outcome was vaccine efficacy against symptomatic, virologically confirmed dengue (VCD), regardless of disease severity or serotype, occurring more than 28 days after the third injection. RESULTS: A total of 20,869 healthy children received either vaccine or placebo. At baseline, 79.4% of an immunogenicity subgroup of 1944 children had seropositive status for one or more dengue serotypes. In the per-protocol population, there were 176 VCD cases (with 11,793 person-years at risk) in the vaccine group and 221 VCD cases (with 5809 person-years at risk) in the control group, for a vaccine efficacy of 60.8% (95% confidence interval [CI], 52.0 to 68.0). In the intention-to-treat population (those who received at least one injection), vaccine efficacy was 64.7% (95% CI, 58.7 to 69.8). Serotype-specific vaccine efficacy was 50.3% for serotype 1, 42.3% for serotype 2, 74.0% for serotype 3, and 77.7% for serotype 4. Among the severe VCD cases, 1 of 12 was in the vaccine group, for an intention-to-treat vaccine efficacy of 95.5%. Vaccine efficacy against hospitalization for dengue was 80.3%. The safety profile for the CYD-TDV vaccine was similar to that for placebo, with no marked difference in rates of adverse events. CONCLUSIONS: The CYD-TDV dengue vaccine was efficacious against VCD and severe VCD and led to fewer hospitalizations for VCD in five Latin American countries where dengue is endemic. (Funded by Sanofi Pasteur; ClinicalTrials.gov number, NCT01374516.).


Assuntos
Vacinas contra Dengue , Vírus da Dengue/genética , Dengue/prevenção & controle , Adolescente , Anticorpos Antivirais/sangue , Criança , Dengue/imunologia , Dengue/virologia , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Vírus da Dengue/isolamento & purificação , Doenças Endêmicas/prevenção & controle , Feminino , Hospitalização , Humanos , Análise de Intenção de Tratamento , América Latina , Masculino , Sorogrupo , Índice de Gravidade de Doença , Método Simples-Cego , Resultado do Tratamento , Vacinas Atenuadas/imunologia
2.
Appl Environ Microbiol ; 83(6)2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28062461

RESUMO

The genetic diversity of bacterial populations nodulating Lupinus micranthus in five geographical sites from northern Tunisia was examined. Phylogenetic analyses of 50 isolates based on partial sequences of recA and gyrB grouped strains into seven clusters, five of which belong to the genus Bradyrhizobium (28 isolates), one to Phyllobacterium (2 isolates), and one, remarkably, to Microvirga (20 isolates). The largest Bradyrhizobium cluster (17 isolates) grouped with the B. lupini species, and the other five clusters were close to different recently defined Bradyrhizobium species. Isolates close to Microvirga were obtained from nodules of plants from four of the five sites sampled. We carried out an in-depth phylogenetic study with representatives of the seven clusters using sequences from housekeeping genes (rrs, recA, glnII, gyrB, and dnaK) and obtained consistent results. A phylogeny based on the sequence of the symbiotic gene nodC identified four groups, three formed by Bradyrhizobium isolates and one by the Microvirga and Phyllobacterium isolates. Symbiotic behaviors of the representative strains were tested, and some congruence between symbiovars and symbiotic performance was observed. These data indicate a remarkable diversity of L. micranthus root nodule symbionts in northern Tunisia, including strains from the Bradyrhizobiaceae, Methylobacteriaceae, and Phyllobacteriaceae families, in contrast with those of the rhizobial populations nodulating lupines in the Old World, including L. micranthus from other Mediterranean areas, which are nodulated mostly by Bradyrhizobium strains.IMPORTANCELupinus micranthus is a legume broadly distributed in the Mediterranean region and plays an important role in soil fertility and vegetation coverage by fixing nitrogen and solubilizing phosphate in semiarid areas. Direct sowing to extend the distribution of this indigenous legume can contribute to the prevention of soil erosion in pre-Saharan lands of Tunisia. However, rhizobial populations associated with L. micranthus are poorly understood. In this context, the diversity of endosymbionts of this legume was investigated. Most Lupinus species are nodulated by Bradyrhizobium strains. This work showed that about half of the isolates from northern Tunisian soils were in fact Bradyrhizobium symbionts, but the other half were found unexpectedly to be bacteria within the genera Microvirga and Phyllobacterium These unusual endosymbionts may have a great ecological relevance. Inoculation with the appropriate selected symbiotic bacterial partners will increase L. micranthus survival with consequent advantages for the environment in semiarid areas of Tunisia.


Assuntos
Bradyrhizobium/isolamento & purificação , Lupinus/microbiologia , Methylobacteriaceae/isolamento & purificação , Phyllobacteriaceae/isolamento & purificação , Nódulos Radiculares de Plantas/microbiologia , Biodiversidade , Bradyrhizobium/classificação , Bradyrhizobium/genética , DNA Girase/genética , DNA Bacteriano/genética , Genes Essenciais/genética , Methylobacteriaceae/classificação , Methylobacteriaceae/genética , Phyllobacteriaceae/classificação , Phyllobacteriaceae/genética , Filogenia , Nodulação/fisiologia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Microbiologia do Solo , Simbiose/fisiologia , Tunísia
3.
BMC Pediatr ; 16: 13, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26795213

RESUMO

BACKGROUND: Neonates admitted to neonatal intensive care units (NICU) are exposed to a wide variety of drugs, most without any data on safety and efficacy. OBJECTIVE: To describe the drugs prescribed to different groups of neonates hospitalized in a NICU, and to analyze off-label use and harmful potential of drugs, in terms of the potential risks. METHODS: This was a six-month retrospective cohort study of drug use in a NICU, with neonates who were inpatients for a period of over 24 hours, and using prescription data from electronic medical records. Drug information found in the package leaflets, in the British National Formulary for Children 2012-2013, and in the Thomson Micromedex database were compared. Drugs and excipients considered potentially harmful were evaluated according to the literature. RESULTS: One hundred ninety-two neonates were included in the study, with a mean gestational age (GA) of 33.3 weeks (SD ± 4.3), 75.0 % were preterm, with an average of 18.8 days of hospitalization (SD ± 18.1), and a total of 3617 neonates-day. 3290 prescriptions were registered, on average 17.1 prescriptions/neonate (SD ± 17.9) and 8.8 drugs/neonate (SD ± 5.9). The number of prescriptions and drugs was higher in neonates with GA <31 weeks (p <0.05). Anti-infectives for systemic use, blood, alimentary tract and metabolism drug groups were more frequent, varying according to the GA. Neonates (99.5 %) were exposed to unlicensed drugs (UL) and off label use (OL), more frequently in GA <28 weeks (p <0.05). Most OL drugs used were indicated for newborns. 15 potentially harmful drugs were used in more than 70 % of the neonates, and most were OL; exposure to harmful excipients occurred in 91.6 % of the neonates, a percentage even higher when considering immature neonates. CONCLUSIONS: Immature neonates in a Brazilian NICU are exposed to a variety of OL, UL and potentially harmful drugs and excipients.


Assuntos
Uso de Medicamentos/estatística & dados numéricos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Unidades de Terapia Intensiva Neonatal , Terapia Intensiva Neonatal/métodos , Uso Off-Label/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Brasil , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Terapia Intensiva Neonatal/estatística & dados numéricos , Masculino , Estudos Retrospectivos , Medição de Risco
4.
J Biol Chem ; 289(31): 21217-29, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24942742

RESUMO

[NiFe] hydrogenases are key enzymes for the energy and redox metabolisms of different microorganisms. Synthesis of these metalloenzymes involves a complex series of biochemical reactions catalyzed by a plethora of accessory proteins, many of them required to synthesize and insert the unique NiFe(CN)2CO cofactor. HypC is an accessory protein conserved in all [NiFe] hydrogenase systems and involved in the synthesis and transfer of the Fe(CN)2CO cofactor precursor. Hydrogenase accessory proteins from bacteria-synthesizing hydrogenase in the presence of oxygen include HupK, a scaffolding protein with a moderate sequence similarity to the hydrogenase large subunit and proposed to participate as an intermediate chaperone in the synthesis of the NiFe cofactor. The endosymbiotic bacterium Rhizobium leguminosarum contains a single hydrogenase system that can be expressed under two different physiological conditions: free-living microaerobic cells (∼ 12 µm O2) and bacteroids from legume nodules (∼ 10-100 nm O2). We have used bioinformatic tools to model HupK structure and interaction of this protein with HypC. Site-directed mutagenesis at positions predicted as critical by the structural analysis have allowed the identification of HupK and HypC residues relevant for the maturation of hydrogenase. Mutant proteins altered in some of these residues show a different phenotype depending on the physiological condition tested. Modeling of HypC also predicts the existence of a stable HypC dimer whose presence was also demonstrated by immunoblot analysis. This study widens our understanding on the mechanisms for metalloenzyme biosynthesis in the presence of oxygen.


Assuntos
Proteínas de Bactérias/metabolismo , Hidrogenase/metabolismo , Oxigênio/metabolismo , Rhizobium leguminosarum/enzimologia , Proteínas de Bactérias/química , Sequência de Bases , Primers do DNA , Eletroforese em Gel de Poliacrilamida , Modelos Moleculares , Ligação Proteica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
5.
Int J Syst Evol Microbiol ; 64(Pt 6): 2072-2078, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24664579

RESUMO

A group of strains isolated from root nodules of Phaseolus lunatus (Lima bean) in Peru were characterized by genotypic, genomic and phenotypic methods. All strains possessed identical 16S rRNA gene sequences that were 99.9% identical to that of Bradyrhizobium lablabi CCBAU 23086(T). Despite having identical 16S rRNA gene sequences, the Phaseolus lunatus strains could be divided into two clades by sequence analysis of recA, atpD, glnII, dnaK and gyrB genes. The genome sequence of a representative of each clade was obtained and compared to the genomes of closely related species of the genus Bradyrhizobium. Average nucleotide identity values below the species circumscription threshold were obtained when comparing the two clades to each other (88.6%) and with all type strains of the genus Bradyrhizobium (≤92.9%). Phenotypes distinguishing both clades from all described and closely related species of the genus Bradyrhizobium were found. On the basis of the results obtained, two novel species, Bradyrhizobium paxllaeri sp. nov. (type strain LMTR 21(T) = DSM 18454(T) = HAMBI 2911(T)) and Bradyrhizobium icense sp. nov. (type strain LMTR 13(T) = HAMBI 3584(T) = CECT 8509(T) = CNPSo 2583(T)), are proposed to accommodate the uncovered clades of Phaseolus lunatus bradyrhizobia. These species share highly related but distinct nifH and nodC symbiosis genes.


Assuntos
Bradyrhizobium/classificação , Phaseolus/microbiologia , Filogenia , Nódulos Radiculares de Plantas/metabolismo , Técnicas de Tipagem Bacteriana , Composição de Bases , Bradyrhizobium/genética , Bradyrhizobium/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Dados de Sequência Molecular , Fixação de Nitrogênio , Hibridização de Ácido Nucleico , Peru , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Simbiose
6.
Antonie Van Leeuwenhoek ; 105(6): 1121-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24756908

RESUMO

Fifty-one rhizobial strains isolated from root nodules of Cytisus villosus growing in Northeastern Algeria were characterized by genomic and phenotypic analyses. Isolates were grouped into sixteen different patterns by PCR-RAPD. The phylogenetic status of one representative isolate from each pattern was examined by multilocus sequence analyses of four housekeeping genes (16S rRNA, glnII, recA, and atpD) and one symbiotic gene (nodC). Analysis of 16S rRNA gene sequences showed that all the isolates belonged to the genus Bradyrhizobium. Phylogenetic analyses based on individual or concatenated genes glnII, recA, and atpD indicated that strains cluster in three distinct groups. Ten out of the sixteen strains grouped together with Bradyrhizobium japonicum, while a second group of four clustered with Bradyrhizobium canariense. The third group, represented by isolates CTS8 and CTS57, differed significantly from all other bradyrhizobia known to nodulate members of the Genisteae tribe. In contrast with core genes, sequences of the nodC symbiotic gene from all the examined strains form a homogeneous group within the genistearum symbiovar of Bradyrhizobium. All strains tested nodulated Lupinus angustifolius, Lupinus luteus, and Spartium junceum but not Glycine max. From these results, it is concluded that C. villosus CTS8 and CTS57 strains represent a new lineage within the Bradyrhizobium genus.


Assuntos
Bradyrhizobium/classificação , Bradyrhizobium/isolamento & purificação , Cytisus/microbiologia , Cytisus/fisiologia , Nodulação , Argélia , Proteínas de Bactérias/genética , Bradyrhizobium/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes Bacterianos , Lupinus/microbiologia , Lupinus/fisiologia , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Spartium/microbiologia , Spartium/fisiologia
7.
Mol Phylogenet Evol ; 67(3): 626-30, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23499616

RESUMO

Nod factor modifications mediated by nodZ and nolL gene products (fucosylation and acetylation of fucose residues, respectively) were probably later acquisitions in the nodulation process. Novel phylogenetic analyses suggest that nodZ and nolL genes were transferred from Bradyrhizobium to other nodule bacteria. These bradyrhizobial genes are highly diverse while rhizobial, sinorhizobial and mesorhizobial nodZ and nolL genes are represented by few branches among those from bradyrhizobia. These genes in novel rhizobial backgrounds may have favored efficient nodulation in legume hosts commonly associated with Bradyrhizobium strains.


Assuntos
Bradyrhizobium/classificação , Bradyrhizobium/genética , Genes Bacterianos , Filogenia , Rhizobium/classificação , Rhizobium/genética , Variação Genética , Dados de Sequência Molecular , Simbiose
8.
Biology (Basel) ; 12(5)2023 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-37237492

RESUMO

The genes of the type VI secretion system (T6SS) from Rhizobium etli Mim1 (ReMim1) that contain possible effectors can be divided into three modules. The mutants in them indicated that they are not required for effective nodulation with beans. To analyze T6SS expression, a putative promoter region between the tssA and tssH genes was fused in both orientations to a reporter gene. Both fusions are expressed more in free living than in symbiosis. When the module-specific genes were studied using RT-qPCR, a low expression was observed in free living and in symbiosis, which was clearly lower than the structural genes. The secretion of Re78 protein from the T6SS gene cluster was dependent on the presence of an active T6SS. Furthermore, the expression of Re78 and Re79 proteins in E. coli without the ReMim1 nanosyringe revealed that these proteins behave as a toxic effector/immunity protein pair (E/I). The harmful action of Re78, whose mechanism is still unknown, would take place in the periplasmic space of the target cell. The deletion of this ReMim1 E/I pair resulted in reduced competitiveness for bean nodule occupancy and in lower survival in the presence of the wild-type strain.

9.
Nurs Open ; 10(12): 7703-7712, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37775964

RESUMO

AIM: To translate and culturally adapt the FRAIL scale into Spanish and perform a preliminary test of diagnostic accuracy in patients admitted to intensive care units. DESIGN: Cross-sectional diagnostic study. METHODS: Five intensive care units (ICU) in Spain were participated. Stage 1: Three native Spanish-speaking bilingual translators familiar with the field of critical care translated the scale from English into Spanish. Stage 2: Three native English-speaking bilingual translators familiar with critical care medicine. Stage 3: Authors of the original scale compared the English original and back-translated versions of the scale. Stage 4: Five nurses with more than 5 years of ICU experience and five critical care physicians assessed the comprehension and relevance of each of the items of the Spanish version in 30 patients of 3 different age ranges (<50, 50-65 and >65 years). RESULTS: The FRAIL scale was translated and adapted cross-culturally for patients admitted to intensive care units in Spain. The process consisted of four stages: translation, back translation, comparison and pilot test. There was good correspondence between the original scale and the Spanish version in 100% of the items. The participating patients assessed the relevance (content validity) and comprehensibility (face validity) of each of the items of the first Spanish version. The relevance of some of the items scored low when the scale was used in patients younger than 65 years. CONCLUSIONS: We have cross-culturally adapted the FRAIL scale, originally in English, to Spanish for its use in the critical care medical setting in Spanish-speaking countries. IMPLICATIONS FOR PROFESSIONALS: Physicians and nurses can apply the new scale to all patients admitted to the intensive care units. Nursing care can be adapted according to frailty, trying to reduce the side effects of admission to these units for the most fragile patients. REPORTING METHOD: The manuscript's authors have adhered to the EQUATOR guidelines, using the COSMIN reporting guideline for studies on the measurement properties of patient-reported outcome measures. PATIENT OR PUBLIC CONTRIBUTION: In a pilot clinical study, we applied the first version of the FRAIL-Spain scale to intensive care unit (ICU) patients. Five nurses with more than 5 years of ICU experience and five critical care physicians assessed the relevance (content validity) and comprehensibility (face validity) of the five items of the first Spanish version. Relevance was assessed using a 4-point Likert scale ranging from 1 (no relevance) to 4 (high relevance), and comprehensibility was assessed as poor, acceptable or good. Each health professional applied the scale to three patients (total number of patients = 30) of three different age ranges (<50, 50-65 and >65 years) and recorded the time of application of the scale to each patient. Although the frailty scales were initially created by geriatricians to be applied to the elders, there is little experience with their application in critically ill patients of any age. Therefore, more information is needed to determine the relevance of using this scale in critical care patients. In this pilot study, we considered that nurses and critical care physicians should evaluate frailty using this adapted scale in adult patients admitted to the Intensive Care Units.


Assuntos
Comparação Transcultural , Fragilidade , Adulto , Idoso , Humanos , Espanha , Estado Terminal , Projetos Piloto , Estudos Transversais , Idoso Fragilizado , Fragilidade/diagnóstico
10.
Ann Diagn Pathol ; 15(5): 333-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21665507

RESUMO

Renal cell carcinoma (RCC) with rhabdoid morphology (RCC-RM) is a recently described variant of RCC, which has an aggressive biologic behavior and poor prognosis, akin to sarcomatoid RCC. The current World Health Organization classification of RCC does not include the rhabdoid phenotype as a distinct histologic entity. The aim of this study is to investigate whether RCC-RM represents a dedifferentiation of a classifiable-type World Health Organization RCC or a carcinosarcoma with muscle differentiation. We reviewed 168 cases of RCC obtained between 2003 and 2008. From these cases, 10 (6%) were found to have areas of classic rhabdoid morphology. Immunohistochemistry for cytokeratin, epithelial membrane antigen, desmin, CD10, and CD117 was performed in each case using the labeled streptavidin-biotin method. Rhabdoid differentiation was identified in association with conventional-type RCC (9) and with unclassifiable-type RCC with spindle cell morphology (1). In all cases, both the rhabdoid and nonrhabdoid tumoral areas were positive for cytokeratin and epithelial membrane antigen and negative for desmin. Cytokeratin positivity in the rhabdoid areas was focal. In cases associated with conventional-type RCC, CD10 was positive in both the rhabdoid and nonrhabdoid foci. CD117 was negative in these tumors. The unclassifiable-type RCC with spindle cell morphology was negative for both CD10 and CD117. The similar immunophenotype between the rhabdoid and nonrhabdoid tumoral foci supports the origin of the rhabdoid cells from the classifiable-type RCC. Areas of rhabdoid morphology do not represent muscle metaplastic differentiation. Renal cell carcinoma with rhabdoid morphology may represent a dedifferentiation of a classifiable-type RCC, similar to that of sarcomatoid differentiation. The recognition of RCC-RM is important as it allows for the inclusion of these high-grade malignancies into a category associated with poor prognosis despite lacking the spindle cell component classically identified as sarcomatoid change.


Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Carcinoma de Células Renais/classificação , Carcinoma de Células Renais/metabolismo , Carcinossarcoma/patologia , Desdiferenciação Celular , Feminino , Humanos , Imuno-Histoquímica , Imunofenotipagem , Neoplasias Renais/classificação , Neoplasias Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Neprilisina/análise , Prognóstico , Proteínas Proto-Oncogênicas c-kit/análise , Tumor Rabdoide/patologia
11.
Syst Appl Microbiol ; 42(6): 126015, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31591000

RESUMO

Three bacterial strains, LmiM8T, LmiE10 and LluTb3, isolated from nitrogen-fixing nodules of Lupinus micranthus (Lmi strains) and L. luteus (Llu strain) growing in Northern Tunisia were analysed using genetic, phenotypic and symbiotic approaches. Phylogenetic analyses based on rrs and concatenated gyrB and dnaK genes suggested that these Lupinus strains constitute a new Microvirga species with identities ranging from 95 to 83% to its closest relatives Microvirga makkahensis, M. vignae, M. zambiensis, M. ossetica, and M. lotononidis. The genome sequences of strains LmiM8T and LmiE10 exhibited pairwise Average Nucleotide Identities (ANIb) above 99.5%, significantly distant (73-89% pairwise ANIb) from other Microvirga species sequenced (M. zambiensis and M. ossetica). A phylogenetic analysis based on the symbiosis-related gene nodA placed the sequences of the new species in a divergent clade close to Mesorhizobium, Microvirga and Bradyrhizobium strains, suggesting that the M. tunisiensis strains represent a new symbiovar different from the Bradyrhizobium symbiovars defined to date. In contrast, the phylogeny derived from another symbiosis-related gene, nifH, reproduced the housekeeping genes phylogenies. The study of morphological, phenotypical and physiological features, including cellular fatty acid composition of the novel isolates demonstrated their unique profile regarding close reference Microvirga strains. Strains LmiM8T, LmiE10 and LluTb3 were able to nodulate several Lupinus spp. Based on genetic, genomic and phenotypic data presented in this study, these strains should be grouped within a new species for which the name Microvirga tunisiensis sp. nov. is proposed (type strain LmiM8T=CECT 9163T, LMG 29689T).


Assuntos
Lupinus/microbiologia , Methylobacteriaceae/classificação , Filogenia , Nódulos Radiculares de Plantas/microbiologia , Antibacterianos/farmacologia , Ácidos Graxos/química , Genes Bacterianos/genética , Genes Essenciais/genética , Methylobacteriaceae/química , Methylobacteriaceae/efeitos dos fármacos , Methylobacteriaceae/genética , Fenótipo , Análise de Sequência de DNA , Especificidade da Espécie , Simbiose/genética , Tunísia
12.
FEMS Microbiol Ecol ; 95(5)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977796

RESUMO

The Type VI secretion systems (T6SSs) allow bacteria to translocate effector proteins to other bacteria or to eukaryotic cells. However, little is known about the role of T6SS in endosymbiotic bacteria. In this work we describe the T6SS of Rhizobium etli Mim1, a bacteria able to effectively nodulate common beans. Structural genes and those encoding possible effectors have been identified in a 28-gene DNA region of R. etli Mim1 pRetMIM1f plasmid. Immunodetection of Hcp protein, a conserved key structural component of T6SS systems, indicates that this secretion system is active at high cell densities, in the presence of root exudates, and in bean nodules. Rhizobium etli mutants affected in T6SS structural genes produced plants with lower dry weight and smaller nodules than the wild-type strain, indicating for the first time that the T6SS plays a positive role in Rhizobium-legume symbiosis.


Assuntos
Proteínas de Bactérias/metabolismo , Fabaceae/microbiologia , Rhizobium etli/metabolismo , Simbiose , Sistemas de Secreção Tipo VI/metabolismo , Proteínas de Bactérias/genética , Fabaceae/fisiologia , Plasmídeos/genética , Plasmídeos/metabolismo , Rhizobium etli/genética , Sistemas de Secreção Tipo VI/genética
13.
Pathology ; 40(2): 161-75, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18203038

RESUMO

Infectious and parasitic diseases have always challenged man. Although many of them are typically seen in some areas of the world and can be adequately managed by just improving socioeconomic status and sanitary conditions, they are still quite prevalent and may sometimes be seen outside their original geographical areas. Human migration due to different reasons, tourism, blood transfusion and solid organ transplantation has created new concerns for health professionals all over the world. If not for diagnostic purposes, at least these tropical and infectious diseases should be largely known because their epidemiology, pathogenesis, host/parasite interaction, inflammatory and reparative responses are quite interesting and teach us about human biology. Curiosity is inherent to pathology practice and so we are compelled to look for things other than tumours or degenerative diseases. This review focuses on infectious and parasitic diseases found in a developing country and brings up-to-date information on diseases caused by viruses (dengue, yellow fever), bacteria (typhoid fever, leprosy), parasites (Chagas' disease, cutaneous and visceral leishmaniasis, amoebiasis, Capillaria hepatica, schistosomiasis, cysticercosis) and caused by fungi (paracoccidioidomycosis, cryptococcosis, histoplasmosis) that may be useful for pathologists when facing somewhat strange cases from developing countries.


Assuntos
Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/patologia , Adolescente , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/patologia , Brasil , Criança , Pré-Escolar , Países em Desenvolvimento , Humanos , Lactente , Recém-Nascido , Micoses/diagnóstico , Micoses/patologia , Doenças Parasitárias/diagnóstico , Doenças Parasitárias/patologia
14.
FEMS Microbiol Lett ; 365(5)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29281013

RESUMO

Several genes coding for proteins with metal ion-inducible autocleavage (MIIA) domains were identified in type III secretion system tts gene clusters from draft genomes of recently isolated Bradyrhizobium spp. MIIA domains have been first described in the effectors NopE1 and NopE2 of Bradyrhizobium diazoefficiens USDA 110. All identified genes are preceded by tts box promoter motifs. The identified proteins contain one or two MIIA domains. A phylogenetic analysis of 35 MIIA domain sequences from 16 Bradyrhizobium strains revealed four groups. The protein from Bradyrhizobium sp. LmjC strain contains a single MIIA domain and was designated MdcE (MdcELmjC). It was expressed as a fusion to maltose-binding protein (MalE) in Escherichia coli and subsequently purified by affinity chromatography. Recombinant MalE-MdcELmjC-Strep protein exhibited autocleavage in the presence of Ca2+, Cu2+, Cd2+ and Mn2+, but not in the presence of Mg2+, Ni2+ or Co2+. Site-directed mutagenesis at the predicted cleavage site abolished autocleavage activity of MdcELmjC. An LmjC mdcE- mutant was impaired in the ability to nodulate Lupinus angustifolius and Macroptilium atropurpureum.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Bradyrhizobium/genética , Bradyrhizobium/metabolismo , Nodulação , Proteínas de Bactérias/genética , Bradyrhizobium/classificação , Cátions/metabolismo , Escherichia coli/genética , Fabaceae/microbiologia , Mutação , Filogenia , Regiões Promotoras Genéticas , Domínios Proteicos/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Sistemas de Secreção Tipo III/genética
15.
Syst Appl Microbiol ; 41(5): 487-493, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29803609

RESUMO

In this study, a polyphasic approach was used to analyze three representative strains (LmiH4, LmiM2 and LmiT21) from a collection of six previously described strains isolated in Tunisia from root nodules of Lupinus micranthus. The phylogenetic analysis of the concatenated rrs, recA and glnII genes showed that strain LmiH4 had 100% concatenated gene sequence identity with the type strain Bradyrhizobium retamae Ro19T. Similarly, strain LmiM2 shared 100% concatenated gene sequence identity with the species Bradyrhizobium valentinum LmjM3T. However, strain LmiT21 showed an identical concatenated gene sequence with reference strain Phyllobacterium sophorae CCBAU03422T. The recA-glnII concatenated protein-coding genes used produced incongruent phylogenies compared with 16S rDNA phylogeny. The nodC gene analysis showed that the strains were phylogenetically divergent to the Bradyrhizobium symbiovars defined to date, and represented two new symbiovars. Plant infection analysis revealed that the three strains showed moderate host range and symbiotic specificities. Based on their symbiotic characteristics, we propose that the three strains isolated from Lupinus micranthus nodules belong to two new symbiovars, with the first denominated lupini within the two species Bradyrhizobium valentinum (type strain LmiM2) and B. retamae (type strain LmiH4), and the second denominated mediterranense within the species P. sophorae (type strain LmiT21).


Assuntos
Bradyrhizobium/classificação , Lupinus/microbiologia , Phyllobacteriaceae/classificação , Filogenia , Nódulos Radiculares de Plantas/microbiologia , Simbiose/fisiologia , Bradyrhizobium/genética , Bradyrhizobium/isolamento & purificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Genes Bacterianos/genética , Genes Essenciais/genética , Fenótipo , Phyllobacteriaceae/genética , Phyllobacteriaceae/isolamento & purificação , Nodulação/genética , Análise de Sequência de DNA , Microbiologia do Solo , Especificidade da Espécie , Simbiose/genética , Tunísia
16.
Odontoestomatol ; 25(41)2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1440708

RESUMO

El bruxismo del sueño ha sido extensamente estudiado en las últimas décadas pero aún persiste una considerable controversia científica en relación al bruxismo de la vigilia. El presente trabajo de revisión se focalizó en este tema, incluyendo 45 artículos publicados entre los años 2011 al año 2020. Los consensos internacionales plantean avances en nuevas clasificaciones diagnósticas, que contemplan herramientas como cuestionarios, examen clínico, electromiografía, polisomnografía, evaluación ecológica momentánea y métodos de muestreo de experiencias. Se considera al bruxismo de la vigilia un problema comportamental, pasible de ser tratado mediante terapias comportamentales que lo controlen. La evaluación ecológica momentánea permite capturar información comportamental en tiempo real y se presenta como una herramienta valiosa para el diagnóstico y evaluación del bruxismo de la vigilia. A pesar de numerosos avances presentados en esta revisión, aún se requieren estudios que exploren esta área del conocimiento, especialmente en los mecanismos fisiopatológicos y los posibles tratamientos.


O bruxismo do sono tem sido amplamente estudado nas últimas décadas, mas ainda persiste considerável controvérsia científica em relação ao bruxismo de vigília. O presente trabalho de revisão focou nesse tema, incluindo 45 artigos publicados entre 2011 e 2020. Consensos internacionais propõem avanços em novas classificações diagnósticas, que incluem ferramentas como questionários, exame clínico, eletromiografia, polissonografia, avaliação ecológica momentânea e métodos de amostragem de experiência. O bruxismo de vigília é considerado um problema comportamental, que pode ser tratado por terapias comportamentais que o controlam. A avaliação ecológica momentânea permite capturar informações comportamentais em tempo real e se apresenta como uma ferramenta valiosa para o diagnóstico e avaliação do bruxismo em vigília. Apesar dos inúmeros avanços apresentados nesta revisão, ainda são necessários estudos para explorar essa área do conhecimento, principalmente nos mecanismos fisiopatológicos e possíveis tratamentos.

17.
Syst Appl Microbiol ; 41(4): 333-339, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29656850

RESUMO

We have characterized genetic, phenotypic and symbiotic properties of bacterial strains previously isolated from nitrogen-fixing nodules of Retama sphaerocarpa from Northern Algeria. Phylogenetic analyses of 16S rRNA genes and three concatenated housekeeping genes, recA, atpD and glnII, placed them in a new divergent group that is proposed to form a new Bradyrhizobium species, Bradyrhizobium algeriense sp. nov. (type strain RST89T, LMG 27618 and CECT 8363). Based on these phylogenetic markers and on genomic identity data derived from draft genomic sequences, Bradyrhizobium valentinum LmjM3T, Bradyrhizobium lablabi CCBAU 23086T, Bradyrhizobium retamae Ro19T, and Bradyrhizobium jicamae PAC68T are the closest relatives of B. algeriense RST89T, with sequence identities of 92-94% and Average Nucleotide Identities (ANIm) under 90%, well below the 95-96% species circumscription threshold. Likewise, a comparison of whole-cell proteomic patterns, estimated by Matrix-Assisted Laser Desorption/Ionization-Time-of-Flight (MALDI-TOF) mass spectrometric analysis, yielded almost identical spectra between B. algeriense strains but significant differences with B. valentinum, Bradyrhizobium paxllaeri, Bradyrhizobium icense, B. lablabi, B. jicamae and B. retamae. A phylogenetic tree based on symbiotic gene nodC revealed that the B. algeriense sequences cluster with sequences from the Bradyrhizobium symbiovar retamae, previously defined with B. retamae strains isolated from Retama monosperma. B. algeriense strains were able to establish effective symbioses with Retama raetam, Lupinus micranthus, Lupinus albus and Genista numidica, but not with Lupinus angustifolius or Glycine max.


Assuntos
Bradyrhizobium , Fabaceae/microbiologia , Nódulos Radiculares de Plantas/microbiologia , Argélia , Bradyrhizobium/classificação , Bradyrhizobium/genética , Bradyrhizobium/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/análise , Genes Bacterianos/genética , Genes Essenciais/genética , Tipagem de Sequências Multilocus , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Simbiose
18.
Genes (Basel) ; 9(2)2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29364862

RESUMO

Rhizobium leguminosarum bv. viciae is a soil α-proteobacterium that establishes a diazotrophic symbiosis with different legumes of the Fabeae tribe. The number of genome sequences from rhizobial strains available in public databases is constantly increasing, although complete, fully annotated genome structures from rhizobial genomes are scarce. In this work, we report and analyse the complete genome of R. leguminosarum bv. viciae UPM791. Whole genome sequencing can provide new insights into the genetic features contributing to symbiotically relevant processes such as bacterial adaptation to the rhizosphere, mechanisms for efficient competition with other bacteria, and the ability to establish a complex signalling dialogue with legumes, to enter the root without triggering plant defenses, and, ultimately, to fix nitrogen within the host. Comparison of the complete genome sequences of two strains of R. leguminosarum bv. viciae, 3841 and UPM791, highlights the existence of different symbiotic plasmids and a common core chromosome. Specific genomic traits, such as plasmid content or a distinctive regulation, define differential physiological capabilities of these endosymbionts. Among them, strain UPM791 presents unique adaptations for recycling the hydrogen generated in the nitrogen fixation process.

19.
Diagn Microbiol Infect Dis ; 90(3): 198-205, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29217418

RESUMO

Molecular characterization of virulence and antimicrobial resistance profiles were determined for Shigella species isolated from children with diarrhea in Fortaleza, Brazil. Fecal specimens were collected along with socioeconomic and clinical data from children with moderate to severe diarrhea requiring emergency care. Shigella spp. were isolated by standard microbiological techniques, and we developed 4 multiplex polymerase chain reaction assays to detect 16 virulence-related genes (VRGs). Antimicrobial susceptibility tests were performed using disk diffusion assays. S. flexneri and S. sonnei were the predominant serogroups. S. flexneri was associated with low monthly incomes; more severe disease; higher number of VRGs; and presence of pic, set, and sepA genes. The SepA gene was associated with more intense abdominal pain. S. flexneri was correlated with resistance to ampicillin and chloramphenicol, whereas S. sonnei was associated with resistance to azithromycin. Strains harboring higher numbers of VRGs were associated with resistance to more antimicrobials. We highlight the correlation between presence of S. flexneri and sepA, and increased virulence and suggest a link to socioeconomic change in northeastern Brazil. Additionally, antimicrobial resistance was associated with serogroup specificity in Shigella spp. and increased bacterial VRGs.


Assuntos
Antibacterianos/farmacologia , Disenteria Bacilar/microbiologia , Shigella flexneri/genética , Shigella flexneri/patogenicidade , Shigella sonnei/genética , Shigella sonnei/patogenicidade , Ampicilina/farmacologia , Azitromicina/farmacologia , Proteínas de Bactérias/genética , Brasil , Cloranfenicol/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana , Disenteria Bacilar/tratamento farmacológico , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Serina Proteases/genética , Shigella flexneri/efeitos dos fármacos , Shigella flexneri/isolamento & purificação , Shigella sonnei/efeitos dos fármacos , Shigella sonnei/isolamento & purificação , Virulência/genética
20.
RSC Adv ; 8(28): 15253-15265, 2018 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-35539474

RESUMO

Direct functionalization of prefabricated free-standing graphene oxide paper (GOP) is the only approach suitable for systematic tuning of its mechanical, thermal and electronic characteristics. However, the traditional liquid-phase functionalization can compromise physical integrity of the paper-like material up to its total disintegration. In the present paper, we attempted to apply an alternative, solvent-free strategy for facile and nondestructive functionalization of GOP with 1-octadecylamine (ODA) and 1,12-diaminododecane (DAD) as representatives of aliphatic amines, and with 1-aminopyrene (AP) and 1,5-diaminonaphthalene (DAN) as examples of aromatic amines. The functionalization can be carried out under moderate heating at 150-180 °C for 2 h in vacuum, and proceeds through both amidation and epoxy ring opening reactions. Comparative characterization of pristine and amine-modified GOP samples was carried out by means of Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopy, thermogravimetric and differential thermal analysis, scanning electron and atomic force microscopy. In addition, we compared stability in water, wettability, electrical conductivity and elastic (Young's) modulus of GOP samples before and after functionalization. The highest content of amine species was obtained in the case of GOP-ODA, followed by GOP-DAD, GOP-AP and GOP-DAN. The functionalization increased mechanical and thermal stability, as well as the electrical conductivity of GOP. The magnitude of each effect depends on the structure of amine employed, which allows for tuning a given GOP characteristic. Morphological characterization showed that, compared to pristine graphene oxide paper, amine-modified mats become relatively ordered layered structures, in which individual GO sheets are organized in a near-parallel fashion.

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