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1.
J Endovasc Ther ; : 15266028241266208, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39082386

RESUMO

PURPOSE: This report presents the endovascular strategies adopted to treat a kidney calculus venous embolism after percutaneous nephrolithotomy and the versatility of endovascular techniques to manage even the most unexpected renovascular complications after urological intervention. According to the literature available in PubMed, Cochrane, SciELO, and Science.gov repositories, this is the first case to our knowledge of renal vein calculus embolism as a complication of percutaneous treatment of kidney stones. CASE REPORT: A 62-year-old woman underwent percutaneous nephrolithotomy to treat a left kidney 2.8-cm staghorn calculi. The stone cracked, leaving a residual fragment in the ureteropelvic junction. Abdominal computed tomography revealed a 0.9-mm extrarenal calculus located inside the left retroaortic renal vein. Calculus was captured using a basket catheter system through a 6F 45-cm sheath positioned in the left common femoral vein (CFV) and accessed by dissection to safely conclude the calculus extraction by venous cut down. The patient was asymptomatically discharged 48 hours after the endovascular procedure, under a rivaroxaban anticoagulation regimen, with no symptoms or renal function impairment until the 6 months of follow-up. CONCLUSION: The endovascular strategy proposed in this case was effective for calculus rescue and venous flow restoration. CLINICAL IMPACT: This case reinforces the adaptability of endovascular therapy in an unexpected scenario. A potentially life-threatening extremely rare adverse event following a common urological procedure could be treated with minimally invasive hybrid treatment, preserving renal function and maintaining venous vascular patency. This report may add a discussion of procedures to manage similar events and bring to the literature a possible strategy to solve the problem.

2.
PLoS Pathog ; 17(9): e1009933, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34525131

RESUMO

Adipose tissue is one of the major reservoirs of Trypanosoma brucei parasites, the causative agent of sleeping sickness, a fatal disease in humans. In mice, the gonadal adipose tissue (AT) typically harbors 2-5 million parasites, while most solid organs show 10 to 100-fold fewer parasites. In this study, we tested whether the AT environment responds immunologically to the presence of the parasite. Transcriptome analysis of T. brucei infected adipose tissue revealed that most upregulated host genes are involved in inflammation and immune cell functions. Histochemistry and flow cytometry confirmed an increasingly higher number of infiltrated macrophages, neutrophils and CD4+ and CD8+ T lymphocytes upon infection. A large proportion of these lymphocytes effectively produce the type 1 effector cytokines, IFN-γ and TNF-α. Additionally, the adipose tissue showed accumulation of antigen-specific IgM and IgG antibodies as infection progressed. Mice lacking T and/or B cells (Rag2-/-, Jht-/-), or the signature cytokine (Ifng-/-) displayed a higher parasite load both in circulation and in the AT, demonstrating the key role of the adaptive immune system in both compartments. Interestingly, infections of C3-/- mice showed that while complement system is dispensable to control parasite load in the blood, it is necessary in the AT and other solid tissues. We conclude that T. brucei infection triggers a broad and robust immune response in the AT, which requires the complement system to locally reduce parasite burden.


Assuntos
Tecido Adiposo/imunologia , Tecido Adiposo/microbiologia , Trypanosoma brucei brucei/imunologia , Tripanossomíase Africana/imunologia , Animais , Camundongos
3.
Proc Natl Acad Sci U S A ; 117(29): 17228-17239, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32616573

RESUMO

The ability of Staphylococcus aureus to infect many different tissue sites is enabled, in part, by its transcriptional regulatory network (TRN) that coordinates its gene expression to respond to different environments. We elucidated the organization and activity of this TRN by applying independent component analysis to a compendium of 108 RNA-sequencing expression profiles from two S. aureus clinical strains (TCH1516 and LAC). ICA decomposed the S. aureus transcriptome into 29 independently modulated sets of genes (i-modulons) that revealed: 1) High confidence associations between 21 i-modulons and known regulators; 2) an association between an i-modulon and σS, whose regulatory role was previously undefined; 3) the regulatory organization of 65 virulence factors in the form of three i-modulons associated with AgrR, SaeR, and Vim-3; 4) the roles of three key transcription factors (CodY, Fur, and CcpA) in coordinating the metabolic and regulatory networks; and 5) a low-dimensional representation, involving the function of few transcription factors of changes in gene expression between two laboratory media (RPMI, cation adjust Mueller Hinton broth) and two physiological media (blood and serum). This representation of the TRN covers 842 genes representing 76% of the variance in gene expression that provides a quantitative reconstruction of transcriptional modules in S. aureus, and a platform enabling its full elucidation.


Assuntos
Regulação Bacteriana da Expressão Gênica , Redes Reguladoras de Genes/genética , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Transcriptoma , Proteínas de Bactérias/genética , Proteínas de Ligação a DNA/genética , Redes e Vias Metabólicas , Proteínas Repressoras/genética , Análise de Sequência de RNA , Fator sigma/genética , Infecções Estafilocócicas , Virulência/genética , Fatores de Virulência/genética
4.
Molecules ; 26(23)2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34885736

RESUMO

Biomass thermochemical liquefaction is a chemical process with multifunctional bio-oil as its main product. Under this process, the complex structure of lignocellulosic components can be hydrolysed into smaller molecules at atmospheric pressure. This work demonstrates that the liquefaction of burned pinewood from forest fires delivers similar conversion rates into bio-oil as non-burned wood does. The bio-oils from four burned biomass fractions (heartwood, sapwood, branches, and bark) showed lower moisture content and higher HHV (ranging between 32.96 and 35.85 MJ/kg) than the initial biomasses. The increased HHV resulted from the loss of oxygen, whereas the carbon and hydrogen mass fractions increased. The highest conversion of bark and heartwood was achieved after 60 min of liquefaction. Sapwood, pinewood, and branches reached a slightly higher conversion, with yields about 8% greater, but with longer liquefaction time resulting in higher energy consumption. Additionally, the van Krevelen diagram indicated that the produced bio-oils were closer and chemically more compatible (in terms of hydrogen and oxygen content) to the hydrocarbon fuels than the initial biomass counterparts. In addition, bio-oil from burned pinewood was shown to be a viable alternative biofuel for heavy industrial applications. Overall, biomass from forest fires can be used for the liquefaction process without compromising its efficiency and performance. By doing so, it recovers part of the lost value caused by wildfires, mitigating their negative effects.


Assuntos
Biomassa , Lignina/química , Óleos de Plantas/química , Polifenóis/química , Incêndios Florestais , Hidrogênio/química , Hidrólise , Oxigênio/química , Peptídeo Hidrolases/química , Pinus/química , Temperatura , Água , Madeira/química
5.
Environ Microbiol ; 21(5): 1575-1585, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30652406

RESUMO

The production of pentabromopseudilin and related brominated compounds by Pseudoalteromonas spp. has recently been linked to the bmp biosynthetic gene cluster. This study explored the distribution and evolutionary history of this gene cluster in the genus Pseudoalteromonas. A phylogeny of the genus revealed numerous clades that do not contain type strains, suggesting considerable species level diversity has yet to be described. Comparative genomics revealed four distinct versions of the gene cluster distributed among 19 of the 101 Pseudoalteromonas genomes examined. These were largely localized to the least inclusive clades containing the Pseudoalteromonas luteoviolacea and Pseudoalteromonas phenolica type strains and show clear evidence of gene and gene cluster loss in certain lineages. Bmp gene phylogeny is largely congruent with the Pseudoalteromonas species phylogeny, suggesting vertical inheritance within the genus. However, the gene cluster is found in three different genomic environments suggesting either chromosomal rearrangement or multiple acquisition events. Bmp conservation within certain lineages suggests the encoded products are highly relevant to the ecology of these bacteria.


Assuntos
Proteínas de Bactérias/genética , Família Multigênica , Pseudoalteromonas/genética , Proteínas de Bactérias/metabolismo , Genoma Bacteriano , Genômica , Filogenia , Pseudoalteromonas/classificação , Pseudoalteromonas/isolamento & purificação , Pseudoalteromonas/metabolismo , Pirróis/química , Pirróis/metabolismo
6.
Appl Environ Microbiol ; 85(21)2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31471305

RESUMO

Staphylococcus aureus is a Gram-positive pathogenic bacterium that colonizes an estimated one-third of the human population and can cause a wide spectrum of disease, ranging from superficial skin infections to life-threatening sepsis. The adaptive mechanisms that contribute to the success of this pathogen remain obscure partially due to a lack of knowledge of its metabolic requirements. Systems biology approaches can be extremely useful in predicting and interpreting metabolic phenotypes; however, such approaches rely on a chemically defined minimal medium as a basis to investigate the requirements of the cell. In this study, a chemically defined minimal medium formulation, termed synthetic minimal medium (SMM), was investigated and validated to support growth of three S. aureus strains: LAC and TCH1516 (USA300 lineage), as well as D592 (USA100 lineage). The formulated SMM was used in an adaptive laboratory evolution experiment to probe the various mutational trajectories of all three strains leading to optimized growth capabilities. The evolved strains were phenotypically characterized for their growth rate and antimicrobial susceptibility. Strains were also resequenced to examine the genetic basis for observed changes in phenotype and to design follow-up metabolite supplementation assays. Our results reveal evolutionary trajectories that arose from strain-specific metabolic requirements. SMM and the evolved strains can also serve as important tools to study antibiotic resistance phenotypes of S. aureusIMPORTANCE As researchers try to understand and combat the development of antibiotic resistance in pathogens, there is a growing need to thoroughly understand the physiology and metabolism of the microbes. Staphylococcus aureus is a threatening pathogen with increased antibiotic resistance and well-studied virulence mechanisms. However, the adaptive mechanisms used by this pathogen to survive environmental stresses remain unclear, mostly due to the lack of information about its metabolic requirements. Defining the minimal metabolic requirements for S. aureus growth is a first step toward unraveling the mechanisms by which it adapts to metabolic stresses. Here, we present the development of a chemically defined minimal medium supporting growth of three S. aureus strains, and we reveal key genetic mutations contributing to improved growth in minimal medium.


Assuntos
Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Análise de Sistemas , Biologia de Sistemas/métodos , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Virulência
7.
J Nat Prod ; 82(8): 2262-2267, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31368305

RESUMO

Photopiperazines A-D (1-4), unsaturated diketopiperazine derivatives, were isolated from the culture broth of a rare, marine-derived actinomycete bacterium, strain AJS-327. This strain shows very poor 16S rRNA sequence similarity to other members of the actinomycete family Streptomycetaceae, indicating it is likely a new lineage within this group. The structures of the photopiperazines were defined by analysis of HR-ESI-TOF-MS spectra in conjunction with the interpretation of 1D and 2D NMR data. The photopiperazines are sensitive to light, causing interconversion among the four olefin geometrical isomers, which made purification of each isomer challenging. The photopiperazines are highly cytotoxic metabolites that show selective toxicity toward U87 glioblastoma and SKOV3 ovarian cancer cell lines.


Assuntos
Actinobacteria/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Piperazinas/química , Streptomycetaceae/química , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma/patologia , Humanos
8.
Sensors (Basel) ; 19(19)2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31547079

RESUMO

Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude and Heading Reference Systems (AHRS), and odometry based on Light Detection and Ranging (LiDAR) sensors. In our LiDAR-based odometry solution, the trunks of the trees are used in a feature-based scan matching algorithm to estimate the relative movement of the vehicle. Our method employs a robust adaptive fusion algorithm based on the unscented Kalman filter. For motion control, we adopt a strategy that integrates a vector field, used to impose the main direction of the movement for the robot, with an optimal probabilistic planner, which is responsible for obstacle avoidance. Experiments with a quadrotor equipped with a planar LiDAR in an actual forest environment is used to illustrate the effectiveness of our approach.

9.
Int Braz J Urol ; 45(5): 1071-1072, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30901175

RESUMO

INTRODUCTION: Robotic-assisted radical prostatectomy is the leading surgical technique and was discussed in Pasadena Consensus Panel (1). The goal of this study is to present the results of the first fifty-five patients submitted to Anterograde Anatomic Radical Retropubic Prostatectomy technique (R2PA2), without adding complexity or cost. MATERIALS AND METHODS: Fifty-five eligible men with localized prostate cancer underwent R2PA2 from January, 2016 to December, 2017. The technique was previously described (2): the main surgical steps were anterograde dissection, ligation of the dorsal vascular complex without dividing, preservation of the bladder neck, nerve sparing, preservation of Denonvilliers' fascia and confection of the running suture anastomosis. All patients were operated on by second-year residents. RESULTS: All procedures were completed as planned, but one converted to retrograde prostatectomy (mean duration, 163.40 minutes; hospital stay, 4 days with 4.20 days of drainage; indwelling vesical catheterization of 9.80 days). Positive surgical margin was found in six T2 staging patient (10.90%) and five T3 (9.10%). Biochemical PSA recurrence occurred in three patients (5.50%). Twenty-four (43.60%) were continent immediately after indwelling catheter removal, seventeen (30.90%) did not wear a pad at one postoperative month while eighteen (30%) used only one safety pad. Five minor complications occurred. CONCLUSION: We were able to perform R2PA2 allowing men who do not have access to this new technology to be operated on with the same technique used in robotic surgery. This method was reproducible by low-volume prostate cancer surgeons; help inexperienced surgeons to develop skills valuable to future training with robotic techniques. ACKNOWLEDGEMENTS This work was supported by the FAPERJ - Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro. Secretaria de Estado de Ciência, Tecnologia e Inovação do Governo do Estado do Rio de Janeiro, Brazil, and Pedro Ernesto University Hospital of the State University of Rio de Janeiro, Brazil. Available at: http://www.intbrazjurol.com.br/video-section/20180421_Carrerette_et_al.


Assuntos
Prostatectomia/métodos , Neoplasias da Próstata/cirurgia , Idoso , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Reprodutibilidade dos Testes , Resultado do Tratamento
10.
J Am Chem Soc ; 140(34): 10775-10784, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30085661

RESUMO

The microbial metabolites known as the macrolides are some of the most successful natural products used to treat infectious and immune diseases. Describing the structures of these complex metabolites, however, is often extremely difficult due to the presence of multiple stereogenic centers inherent in this class of polyketide-derived metabolites. With the availability of genome sequence data and a better understanding of the molecular genetics of natural product biosynthesis, it is now possible to use bioinformatic approaches in tandem with spectroscopic tools to assign the full stereostructures of these complex metabolites. In our quest to discover and develop new agents for the treatment of cancer, we observed the production of a highly cytotoxic macrolide, neaumycin B, by a marine-derived actinomycete bacterium of the genus Micromonospora. Neaumycin B is a complex polycyclic macrolide possessing 19 asymmetric centers, usually requiring selective degradation, crystallization, derivatization, X-ray diffraction analysis, synthesis, or other time-consuming approaches to assign the complete stereostructure. As an alternative approach, we sequenced the genome of the producing strain and identified the neaumycin gene cluster ( neu). By integrating the known stereospecificities of biosynthetic enzymes with comprehensive NMR analysis, the full stereostructure of neaumycin B was confidently assigned. This approach exemplifies how mining gene cluster information while integrating NMR-based structure data can achieve rapid, efficient, and accurate stereostructural assignments for complex macrolides.


Assuntos
Antineoplásicos/química , Genômica/métodos , Macrolídeos/química , Sequência de Aminoácidos , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Biologia Computacional , Humanos , Macrolídeos/isolamento & purificação , Macrolídeos/farmacologia , Micromonospora/química , Micromonospora/genética , Família Multigênica , Alinhamento de Sequência , Estereoisomerismo
11.
BMC Infect Dis ; 18(1): 53, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29370774

RESUMO

BACKGROUND: Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases. METHODS: We genotyped the M. tuberculosis strains using the MIRU-VNTR system. We performed an evolutionary reconstruction of the genotypes with median networks, used in this context for the first time. TB cases from a period of two years were evaluated combining genetic, epidemiological and georeferencing information. RESULTS: The data reveal a unique complex scenario in Porto where the autochthonous population acts as a genetic reservoir of M. tuberculosis diversity with discreet episodes of transmission, mostly undetected using classical epidemiology alone. CONCLUSIONS: Although control policies have been successful in decreasing incidence in Porto, the discerned complexity suggests that, for elimination to be a realistic goal, strategies need to be adjusted and coupled with a continuous genetic characterization of strains and detailed epidemiological evaluation, in order to successfully identify and interrupt transmission chains.


Assuntos
Mycobacterium tuberculosis/genética , Tuberculose/transmissão , Feminino , Genótipo , Humanos , Repetições Minissatélites , Epidemiologia Molecular/métodos , Mycobacterium tuberculosis/patogenicidade , Portugal , Fatores Socioeconômicos , Tuberculose/epidemiologia , Tuberculose/genética
12.
J Immunol ; 197(12): 4714-4726, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27849167

RESUMO

Tuberculosis causes ∼1.5 million deaths every year, thus remaining a leading cause of death from infectious diseases in the world. A growing body of evidence demonstrates that type I IFN plays a detrimental role in tuberculosis pathogenesis, likely by interfering with IFN-γ-dependent immunity. In this article, we reveal a novel mechanism by which type I IFN may confer protection against Mycobacterium tuberculosis infection in the absence of IFN-γ signaling. We show that production of type I IFN by M. tuberculosis-infected macrophages induced NO synthase 2 and inhibited arginase 1 gene expression. In vivo, absence of both type I and type II IFN receptors led to strikingly increased levels of arginase 1 gene expression and protein activity in infected lungs, characteristic of alternatively activated macrophages. This correlated with increased lung bacterial burden and pathology and decreased survival compared with mice deficient in either receptor. Increased expression of other genes associated with alternatively activated macrophages, as well as increased expression of Th2-associated cytokines and decreased TNF expression, were also observed. Thus, in the absence of IFN-γ signaling, type I IFN suppressed the switching of macrophages from a more protective classically activated phenotype to a more permissive alternatively activated phenotype. Together, our data support a model in which suppression of alternative macrophage activation by type I IFN during M. tuberculosis infection, in the absence of IFN-γ signaling, contributes to host protection.


Assuntos
Interferon Tipo I/metabolismo , Pulmão/imunologia , Macrófagos/imunologia , Mycobacterium tuberculosis/imunologia , Óxido Nítrico Sintase Tipo II/metabolismo , Tuberculose Pulmonar/imunologia , Animais , Arginase/genética , Arginase/metabolismo , Carga Bacteriana , Citocinas/metabolismo , Regulação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Pulmão/microbiologia , Ativação de Macrófagos , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/genética , Receptores de Interferon/genética , Transdução de Sinais , Células Th2/imunologia
13.
Int J Syst Evol Microbiol ; 66(1): 347-352, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26514698

RESUMO

Based on genetic, chemotaxonomic and phenotypic characteristics, a novel species belonging to the genus Vibrio is described. The facultatively anaerobic strain S2757T was isolated from a mussel collected in the Solomon Sea (Solomon Islands). Phylogenetic analyses based on sequences of 16S rRNA and fur genes indicated affiliation of the strain to a novel species. This observation was supported by a multilocus sequence analysis including sequences of the housekeeping genes 16S rRNA, gyrB, pyrH, recA and topA. In silico DNA-DNA hybridization and average nucleotide identity values comparing the genomic sequence of strain S2757T with those of closely related type strains were lower than 23 and 82 %, respectively. The DNA G+C content of the strain was 45.3 mol%. Phenotypic and chemotaxonomic analyses clearly differentiated the strain from other Vibrio species. Hence, strain S2757T should be considered to represent a novel species of the genus Vibrio, for which the name Vibrio galatheae sp. nov. is proposed. The type strain is S2757T ( = DSM 100497T = LMG 28895T).


Assuntos
Bivalves/microbiologia , Filogenia , Vibrio/classificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Melanesia , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vibrio/genética , Vibrio/isolamento & purificação
14.
Int J Syst Evol Microbiol ; 66(9): 3737-3742, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27380907

RESUMO

A new aerobic marine bacterium, strain S3431, was isolated from swab samples of an unidentified polychaete near Canal Concepción, Chile. This strain was thought to represent a new taxon within the genus Pseudoalteromonas. Although DNA-DNA reassociation values showed less than 70 % genomic DNA relatedness to established Pseudoalteromonas type strains, it shared 78 % DNA-DNA relatedness with Alteromonas fuliginea DSM 15748 (=KMM 216) (Romanenko et al., 1994). A. fuliginea has later been considered a heterotypic synonym of Pseudoalteromonas citrea(Ivanova et al., 1998). Relatedness between strains S3431, A. fuliginea DSM 15748 and the type strain P. citrea LMG 12323T was therefore studied. Physiological traits and genomic information were shared at a high level by strains S3431 and DSM 15748, but not between these and P. citrea LMG 12323T. There was only approximately 20 % DNA-DNA relatedness between P. citrea LMG 12323T and strains S3431 and DSM 15748. Based on the available phylogenetic and phenotypic data, the reclassification of A. fuliginea DSM 15748 (Romanenko et al., 1995) → Pseudoalteromonas citrea(Ivanova et al., 1998) as Pseudoalteromonas fuligineacomb. nov. is proposed, and strain S3431 should be assigned to this new species. The name Pseudoalteromonas fuliginea is proposed with KMM 216T (=DSM 15748T=CIP 105339T) as the type strain.


Assuntos
Alteromonas/classificação , Filogenia , Poliquetos/microbiologia , Pseudoalteromonas/classificação , Animais , Técnicas de Tipagem Bacteriana , Chile , DNA Bacteriano/genética , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
Mar Drugs ; 14(12)2016 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-27999269

RESUMO

Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae) for chitin degradation using in silico and phenotypic assays. Of 10 chitinolytic strains, three strains, Photobacterium galatheae S2753, Pseudoalteromonas piscicida S2040 and S2724, produced large clearing zones on chitin plates. All strains were antifungal, but against different fungal targets. One strain, Pseudoalteromonas piscicida S2040, had a pronounced antifungal activity against all seven fungal strains. There was no correlation between the number of chitin modifying enzymes as found by genome mining and the chitin degrading activity as measured by size of clearing zones on chitin agar. Based on in silico and in vitro analyses, we cloned and expressed two ChiA-like chitinases from the two most potent candidates to exemplify the industrial potential.


Assuntos
Antifúngicos/isolamento & purificação , Quitina/metabolismo , Quitinases/metabolismo , Pseudoalteromonas/enzimologia , Vibrionaceae/enzimologia , Antifúngicos/farmacologia , Biologia Marinha , Pseudoalteromonas/genética , Vibrionaceae/genética
16.
BMC Genomics ; 16: 158, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25879706

RESUMO

BACKGROUND: Antibiotic resistance in bacteria spreads quickly, overtaking the pace at which new compounds are discovered and this emphasizes the immediate need to discover new compounds for control of infectious diseases. Terrestrial bacteria have for decades been investigated as a source of bioactive compounds leading to successful applications in pharmaceutical and biotech industries. Marine bacteria have so far not been exploited to the same extent; however, they are believed to harbor a multitude of novel bioactive chemistry. To explore this potential, genomes of 21 marine Alpha- and Gammaproteobacteria collected during the Galathea 3 expedition were sequenced and mined for natural product encoding gene clusters. RESULTS: Independently of genome size, bacteria of all tested genera carried a large number of clusters encoding different potential bioactivities, especially within the Vibrionaceae and Pseudoalteromonadaceae families. A very high potential was identified in pigmented pseudoalteromonads with up to 20 clusters in a single strain, mostly NRPSs and NRPS-PKS hybrids. Furthermore, regulatory elements in bioactivity-related pathways including chitin metabolism, quorum sensing and iron scavenging systems were investigated both in silico and in vitro. Genes with siderophore function were identified in 50% of the strains, however, all but one harboured the ferric-uptake-regulator gene. Genes encoding the syntethase of acylated homoserine lactones were found in Roseobacter-clade bacteria, but not in the Vibrionaceae strains and only in one Pseudoalteromonas strains. The understanding and manipulation of these elements can help in the discovery and production of new compounds never identified under regular laboratory cultivation conditions. High chitinolytic potential was demonstrated and verified for Vibrio and Pseudoalteromonas species that commonly live in close association with eukaryotic organisms in the environment. Chitin regulation by the ChiS histidine-kinase seems to be a general trait of the Vibrionaceae family, however it is absent in the Pseudomonadaceae. Hence, the degree to which chitin influences secondary metabolism in marine bacteria is not known. CONCLUSIONS: Utilizing the rapidly developing sequencing technologies and software tools in combination with phenotypic in vitro assays, we demonstrated the high bioactive potential of marine bacteria in an efficient, straightforward manner - an approach that will facilitate natural product discovery in the future.


Assuntos
Genoma Bacteriano , Bactérias Gram-Negativas/genética , Água do Mar/microbiologia , Acil-Butirolactonas/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Quitina/metabolismo , Compostos Férricos/química , Compostos Férricos/metabolismo , Dados de Sequência Molecular , Família Multigênica , Biossíntese de Peptídeos Independentes de Ácido Nucleico/genética , Policetídeo Sintases/genética , Policetídeo Sintases/metabolismo , Pseudoalteromonas/genética , Percepção de Quorum/genética , Roseobacter/genética , Alinhamento de Sequência , Sideróforos/metabolismo , Vibrionaceae/genética
17.
Appl Environ Microbiol ; 81(8): 2745-52, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25662978

RESUMO

Microbial taxonomy is essential in all areas of microbial science. The 16S rRNA gene sequence is one of the main phylogenetic species markers; however, it does not provide discrimination in the family Vibrionaceae, where other molecular techniques allow better interspecies resolution. Although multilocus sequence analysis (MLSA) has been used successfully in the identification of Vibrio species, the technique has several limitations. They include the fact that several locus amplifications and sequencing have to be performed, which still sometimes lead to doubtful identifications. Using an in silico approach based on genomes from 103 Vibrionaceae strains, we demonstrate here the high resolution of the fur gene in the identification of Vibrionaceae species and its usefulness as a phylogenetic marker. The fur gene showed within-species similarity higher than 95%, and the relationships inferred from its use were in agreement with those observed for 16S rRNA analysis and MLSA. Furthermore, we developed a fur PCR sequencing-based method that allowed identification of Vibrio species. The discovery of the phylogenetic power of the fur gene and the development of a PCR method that can be used in amplification and sequencing of the gene are of general interest whether for use alone or together with the previously suggested loci in an MLSA.


Assuntos
Proteínas de Bactérias/genética , Filogenia , Proteínas Repressoras/genética , Vibrionaceae/classificação , Vibrionaceae/genética , Sequência de Bases , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Alinhamento de Sequência
18.
Int J Syst Evol Microbiol ; 65(12): 4503-4507, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26374506

RESUMO

A novel, Gram-negative marine bacterium, S2753T, was isolated from a mussel of the Solomon Sea, Solomon Islands. Analysis of the 16S rRNA gene sequence and whole genome sequence data placed strain S2753T in the genus Photobacterium with the closest relative being Photobacterium halotolerans DSM 18316T (97.7 % 16S rRNA gene similarity). Strain S2753T was able to grow from 15 to 40 °C and in NaCl concentrations of 0.5 to 9 % (w/v). The predominant fatty acids were 16 : 1ω7c/16 : 1ω6c (27.9 %), 16 : 0 (22.1 %) and 18 : 1ω7c/8 : 1ω6c (21.4 %). The genomic DNA G+C mol content was 49.5 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic differences, strain S2753T is considered to represent a novel species of the genus Photobacterium. Furthermore, whole genome sequence analysis comparing S2753T and type-strains of closely related species of the genus Photobacterium also demonstrated that the strain is genomically distinct enough to be considered a novel species. The name Photobacterium galatheae is proposed and the type-strain is S2753T( = LMG 28894T = DSM 100496T).


Assuntos
Bivalves/microbiologia , Photobacterium/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Melanesia , Dados de Sequência Molecular , Photobacterium/genética , Photobacterium/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
19.
Mar Drugs ; 13(3): 1548-51, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25803179

RESUMO

The authors wish to make the following corrections to this paper [1]: Due to duplicated and missing data in Table 3, Page 5533, replace: [...].

20.
Mar Drugs ; 12(11): 5527-46, 2014 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-25419995

RESUMO

Bacterial quorum sensing (QS) and the corresponding signals, acyl homoserine lactones (AHLs), were first described for a luminescent Vibrio species. Since then, detailed knowledge has been gained on the functional level of QS; however, the abundance of AHLs in the family of Vibrionaceae in the environment has remained unclear. Three hundred and one Vibrionaceae strains were collected on a global research cruise and the prevalence and profile of AHL signals in this global collection were determined. AHLs were detected in 32 of the 301 strains using Agrobacterium tumefaciens and Chromobacterium violaceum reporter strains. Ethyl acetate extracts of the cultures were analysed by ultra-high performance liquid chromatography-high resolution mass spectrometry (MS) with automated tandem MS confirmation for AHLs. N-(3-hydroxy-hexanoyl) (OH-C6) and N-(3-hydroxy-decanoyl) (OH-C10) homoserine lactones were the most common AHLs found in 17 and 12 strains, respectively. Several strains produced a diversity of different AHLs, including N-heptanoyl (C7) HL. AHL-producing Vibrionaceae were found in polar, temperate and tropical waters. The AHL profiles correlated with strain phylogeny based on gene sequence homology, however not with geographical location. In conclusion, a wide range of AHL signals are produced by a number of clades in the Vibrionaceae family and these results will allow future investigations of inter- and intra-species interactions within this cosmopolitan family of marine bacteria.


Assuntos
Acil-Butirolactonas/metabolismo , Percepção de Quorum/fisiologia , Vibrionaceae/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Filogenia , RNA Ribossômico 16S/genética , Especificidade da Espécie , Espectrometria de Massas em Tandem/métodos , Vibrionaceae/genética
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