Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Med Ethics ; 49(6): 444-446, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36517227

RESUMO

Hardman and Hutchinson claim that ethics is 'grounded in particular, everyday concerns'. According to them, an implication of this is that ethics courses for (future) clinicians should de-emphasise teaching the theories and principles of philosophical ethics and focus instead on pedagogical activities more closely related to everyday concerns, for example, exposure to real patient accounts. I respond that, even if ethics is an 'everyday' phenomenon, learning philosophical ethics may be of significant practical benefit to clinicians. I argue that the theories of philosophical ethics can reasonably be interpreted as partial, simplified descriptions-or models-of moral phenomena, and that they can be effectively deployed in tandem by clinicians as complementary decision-making tools for help in navigating ethically complex situations in the clinic.


Assuntos
Teoria Ética , Princípios Morais , Humanos , Ética Médica
2.
Appl Clin Inform ; 15(3): 489-500, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38925539

RESUMO

OBJECTIVES: While clinical practice guidelines recommend that oncologists discuss goals of care with patients who have advanced cancer, it is estimated that less than 20% of individuals admitted to the hospital with high-risk cancers have end-of-life discussions with their providers. While there has been interest in developing models for mortality prediction to trigger such discussions, few studies have compared how such models compare with clinical judgment to determine a patient's mortality risk. METHODS: This study is a prospective analysis of 1,069 solid tumor medical oncology hospital admissions (n = 911 unique patients) from February 7 to June 7, 2022, at Memorial Sloan Kettering Cancer Center. Electronic surveys were sent to hospitalists, advanced practice providers, and medical oncologists the first afternoon following a hospital admission and they were asked to estimate the probability that the patient would die within 45 days. Provider estimates of mortality were compared with those from a predictive model developed using a supervised machine learning methodology, and incorporated routine laboratory, demographic, biometric, and admission data. Area under the receiver operating characteristic curve (AUC), calibration and decision curves were compared between clinician estimates and the model predictions. RESULTS: Within 45 days following hospital admission, 229 (25%) of 911 patients died. The model performed better than the clinician estimates (AUC 0.834 vs. 0.753, p < 0.0001). Integrating clinician predictions with the model's estimates further increased the AUC to 0.853 (p < 0.0001). Clinicians overestimated risk whereas the model was extremely well-calibrated. The model demonstrated net benefit over a wide range of threshold probabilities. CONCLUSION: The inpatient prognosis at admission model is a robust tool to assist clinical providers in evaluating mortality risk, and it has recently been implemented in the electronic medical record at our institution to improve end-of-life care planning for hospitalized cancer patients.


Assuntos
Neoplasias , Humanos , Neoplasias/mortalidade , Masculino , Feminino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Medição de Risco/métodos , Idoso , Hospitalização/estatística & dados numéricos
3.
Int J Syst Evol Microbiol ; 63(Pt 12): 4724-4729, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23959829

RESUMO

A novel moderately thermophilic, heterotrophic bacterium was isolated from a deep-sea hydrothermal vent deposit from the Mariner field along the Eastern Lau Spreading Center of the south-western Pacific Ocean. Cells were short motile rods (about 0.4×0.8 µm) that occurred singly or in pairs and were surrounded by a sheath-like membrane or 'toga'. The cells grew between 45 and 65 °C (optimum 57-60 °C) and at pH 4.1-6.0 (optimum pH 5.5-5.7) and grew optimally at 3 % (w/v) NaCl. The isolate grew on a range of carbon and proteinaceous substrates and reduced sulfur. The G+C content of the DNA was about 45 mol%. Phylogenetic analysis of the 16S rRNA gene sequence placed the new isolate as a deeply diverging lineage within the order Thermotogales. Based on the physiological, morphological and phylogenetic data, the isolate represents a novel species of a new genus with the proposed name Mesoaciditoga lauensis gen. nov., sp. nov. The type strain of Mesoaciditoga lauensis is cd-1655R(T) ( = DSM 25116(T) = OCM 1212(T)).


Assuntos
Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/classificação , Fontes Hidrotermais/microbiologia , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/genética , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/isolamento & purificação , Processos Heterotróficos , Dados de Sequência Molecular , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética
4.
JAMA Netw Open ; 5(3): e221078, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35244701

RESUMO

IMPORTANCE: Electronic patient-reported outcomes (ePROs) may have the potential to improve cancer care delivery by enhancing patient quality of life, reducing acute care visits, and extending overall survival. However, the optimal cadence of ePRO assessments is unknown. OBJECTIVE: To determine patient response preferences and the clinical value associated with a daily cadence for ePROs for patients receiving antineoplastic treatment. DESIGN, SETTING, AND PARTICIPANTS: This quality improvement study of adult patients undergoing antineoplastic treatment assessed a remote monitoring program using ePROs that was developed to manage cancer therapy-related symptoms. ePRO data submitted between October 16, 2018 to February 29, 2020, from a single regional site within the Memorial Sloan Kettering Cancer Center network were included. Data were analyzed from April 2020 to January 2022. EXPOSURE: While undergoing active treatment, patients received a daily ePRO assessment that, based on patient responses, generated yellow (moderate) or red (severe) symptom alerts that were sent to clinicians. MAIN OUTCOMES AND MEASURES: The main outcomes assessed included patient response rate, symptom alert frequency, and an analysis of the clinical value of daily ePROs. RESULTS: A total of 217 patients (median [range] age, 66 [31-92] years; 103 [47.5%] women and 114 [52.5%] men) initiating antineoplastic therapy at high risk for symptoms were monitored for a median (range) of 91 (2-369) days. Most patients had thoracic (59 patients [27.2%]), head and neck (48 patients [22.1%]), or gastrointestinal (43 patients [19.8%]) malignant neoplasms. Of 14 603 unique symptom assessments completed, 7349 (50.3%) generated red or yellow symptom alerts. Symptoms commonly generating alerts included pain (665 assessments [23.0%]) and functional status (465 assessments [16.1%]). Most assessments (8438 assessments [57.8%]) were completed at home during regular clinic hours (ie, 9 am-5 pm), with higher response rates on weekdays (58.4%; 95% CI, 57.5%-59.5%) than on weekend days (51.3%; 95% CI, 49.5%-53.1%). Importantly, 284 of 630 unique red alerts (45.1%) surfaced without a prior yellow alert for the same symptom within the prior 7 days; symptom severity fluctuated over the course of a week, and symptom assessments generating a red alert were followed by an acute care visit within 7 days 8.7% of the time compared with 2.9% for assessments without a red alert. CONCLUSIONS AND RELEVANCE: These findings suggest that daily ePRO assessments were associated with increased insight into symptom management in patients undergoing antineoplastic treatment and symptom alerts were associated with risk of acute care.


Assuntos
Antineoplásicos , Neoplasias , Adulto , Idoso , Antineoplásicos/efeitos adversos , Feminino , Humanos , Masculino , Neoplasias/tratamento farmacológico , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Avaliação de Sintomas
5.
JCO Oncol Pract ; 18(12): e1935-e1942, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36265089

RESUMO

PURPOSE: Traditional oncology care models have not effectively identified and managed at-risk patients to prevent acute care. A next step is to harness advances in technology to enable patients to report symptoms any time, enabling digital hovering-intensive symptom monitoring and management. Our objective was to evaluate a digital platform that identifies and remotely monitors high-risk patients initiating antineoplastic therapy with the goal of preventing acute care visits. METHODS: This was a single-institution matched cohort quality improvement study conducted at a National Cancer Institute-designated cancer center between January 1, 2019, and March 31, 2020. Eligible patients were those initiating intravenous antineoplastic therapy who were identified as high risk for seeking acute care. Enrolled patients' symptoms were monitored using a digital platform. A dedicated team of clinicians managed reported symptoms. The primary outcomes of emergency department visits and hospitalizations within 6 months of treatment initiation were analyzed using cumulative incidence analyses with a competing risk of death. RESULTS: Eighty-one patients from the intervention arm were matched by stage and disease with contemporaneous high-risk control patients. The matched cohort had similar baseline characteristics. The cumulative incidence of an emergency department visit for the intervention cohort was 0.27 (95% CI, 0.17 to 0.37) at six months compared with 0.47 (95% CI, 0.36 to 0.58) in the control (P = .01) and of an inpatient admission was 0.23 (95% CI, 0.14 to 0.33) in the intervention cohort versus 0.41 (95% CI, 0.30 to 0.51) in the control (P = .02). CONCLUSION: The narrow employment of technology solutions to complex care delivery challenges in oncology can improve outcomes and innovate care. This program was a first step in using a digital platform and a remote team to improve symptom care for high-risk patients.


Assuntos
Antineoplásicos , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Cuidados Paliativos , Hospitalização , Serviço Hospitalar de Emergência , Estudos de Coortes
6.
JCO Clin Cancer Inform ; 4: 275-289, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32213093

RESUMO

PURPOSE: To create a risk prediction model that identifies patients at high risk for a potentially preventable acute care visit (PPACV). PATIENTS AND METHODS: We developed a risk model that used electronic medical record data from initial visit to first antineoplastic administration for new patients at Memorial Sloan Kettering Cancer Center from January 2014 to September 2018. The final time-weighted least absolute shrinkage and selection operator model was chosen on the basis of clinical and statistical significance. The model was refined to predict risk on the basis of 270 clinically relevant data features spanning sociodemographics, malignancy and treatment characteristics, laboratory results, medical and social history, medications, and prior acute care encounters. The binary dependent variable was occurrence of a PPACV within the first 6 months of treatment. There were 8,067 observations for new-start antineoplastic therapy in our training set, 1,211 in the validation set, and 1,294 in the testing set. RESULTS: A total of 3,727 patients experienced a PPACV within 6 months of treatment start. Specific features that determined risk were surfaced in a web application, riskExplorer, to enable clinician review of patient-specific risk. The positive predictive value of a PPACV among patients in the top quartile of model risk was 42%. This quartile accounted for 35% of patients with PPACVs and 51% of potentially preventable inpatient bed days. The model C-statistic was 0.65. CONCLUSION: Our clinically relevant model identified the patients responsible for 35% of PPACVs and more than half of the inpatient beds used by the cohort. Additional research is needed to determine whether targeting these high-risk patients with symptom management interventions could improve care delivery by reducing PPACVs.


Assuntos
Registros Eletrônicos de Saúde/normas , Serviço Hospitalar de Emergência/organização & administração , Hospitalização/estatística & dados numéricos , Modelos Estatísticos , Neoplasias/tratamento farmacológico , Medição de Risco/métodos , Idoso , Feminino , Humanos , Masculino , Aplicações da Informática Médica , Pessoa de Meia-Idade , Fatores de Risco
7.
JCO Oncol Pract ; 16(10): e1050-e1059, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32468925

RESUMO

PURPOSE: Early detection and management of symptoms in patients with cancer improves outcomes. However, the optimal approach to symptom monitoring and management is unknown. InSight Care is a mobile health intervention that captures symptom data and facilitates patient-provider communication to mitigate symptom escalation. PATIENTS AND METHODS: Patients initiating antineoplastic treatment at a Memorial Sloan Kettering regional location were eligible. Technology supporting the program included the following: a predictive model that identified patient risk for a potentially preventable acute care visit; a secure patient portal enabling communication, televisits, and daily delivery of patient symptom assessments; alerts for concerning symptoms; and a symptom-trending application. The main outcomes of the pilot were feasibility and acceptability evaluated through enrollment and response rates and symptom alerts, and perceived value evaluated on the basis of qualitative patient and provider interviews. RESULTS: The pilot program enrolled 100 high-risk patients with solid tumors and lymphoma (29% of new treatment starts v goal of 25%). Over 6 months of follow-up, the daily symptom assessment response rate was 56% (the goal was 50%), and 93% of patients generated a severe symptom alert. Patients and providers perceived value in the program, and archetypes were developed for program improvement. Enrolled patients were less likely to use acute care than were other high-risk patients. CONCLUSION: InSight Care was feasible and holds the potential to improve patient care and decrease facility-based care. Future work should focus on optimizing the cadence of patient assessments, the workforce supporting remote symptom management, and the return of symptom data to patients and clinical teams.


Assuntos
Neoplasias , Administração dos Cuidados ao Paciente , Telemedicina , Humanos , Linfoma/terapia , Neoplasias/terapia , Projetos Piloto , Avaliação de Sintomas
8.
JCO Clin Cancer Inform ; 3: 1-10, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31225984

RESUMO

PURPOSE: Electronic medical records (EMRs) are a vast resource of potentially mineable data that can be used to complement and extend clinical trials. Extracting and analyzing EMR data are impeded by technical complexities associated with large, multiformat databases. We sought to develop and validate a framework that would overcome the difficulties associated with EMR data and create a simple, portable, and expandable system to better use this resource. MATERIALS AND METHODS: An Internet-accessible program was developed in Python that applied user-defined criteria to identify and extract patient data from Memorial Sloan Kettering databases. A Worker Application composed of individual modules was developed to identify each patient's functional status, smoking status, and treatment classification. The validity of this approach was tested by identifying, extracting, and analyzing data from a patient cohort that paralleled a practice-changing, prospective, randomized phase III clinical trial performed at a different institution. We called this a synthetic clinical trial. RESULTS: Our synthetic clinical trial identified and extracted data on a cohort of 281 patients with lung cancer who matched inclusion criteria and received their first treatment between October 2003 and July 2010. The data extraction modules were precise and accurate, with F-measures greater than 0.98. Results were similar in directionality and magnitude to the chosen comparator clinical trial. CONCLUSION: Our framework offers an accurate and user-friendly interface for identifying and extracting EMR data that can be used to create synthetic clinical trials. Additional studies are needed to validate this approach in other patient cohorts, replicate our findings, and leverage this methodology to improve patient care and accelerate drug development.


Assuntos
Ensaios Clínicos como Assunto , Registros Eletrônicos de Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais
9.
Ann N Y Acad Sci ; 1125: 1-43, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18378585

RESUMO

Thermophilic anaerobes are Archaea and Bacteria that grow optimally at temperatures of 50 degrees C or higher and do not require the use of O(2) as a terminal electron acceptor for growth. The prokaryotes with this type of physiology are studied for a variety of reasons, including (a) to understand how life can thrive under extreme conditions, (b) for their biotechnological potential, and (c) because anaerobic thermophiles are thought to share characteristics with the early evolutionary life forms on Earth. Over 300 species of thermophilic anaerobes have been described; most have been isolated from thermal environments, but some are from mesobiotic environments, and others are from environments with temperatures below 0 degrees C. In this overview, the authors outline the phylogenetic and physiological diversity of thermophilic anaerobes as currently known. The purpose of this overview is to convey the incredible diversity and breadth of metabolism within this subset of anaerobic microorganisms.


Assuntos
Archaea/fisiologia , Bactérias Anaeróbias/classificação , Bactérias Anaeróbias/genética , Variação Genética , Temperatura Alta , Archaea/classificação , Archaea/genética , Consumo de Oxigênio , Filogenia
10.
J Oncol Pract ; 14(8): e484-e495, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30016125

RESUMO

PURPOSE: The Centers for Medicare & Medicaid Services (CMS) identifies suboptimal management of treatment toxicities as a care gap and proposes the measurement of hospital performance on the basis of emergency department visits for 10 common symptoms. Current management strategies do not address symptom co-occurrence. METHODS: We evaluated symptom co-occurrence in three patient cohorts that presented to a cancer hospital urgent care center in 2016. We examined both the CMS-identified symptoms and an expanded clinician-identified set defined as symptoms that could be safely managed in the outpatient setting if identified early and managed proactively. The cohorts included patients who presented with a CMS-defined symptom within 30 days of treatment, patients who presented within 30 days of treatment with a symptom from the expanded set, and patients who presented with a symptom from the expanded set within 30 days of treatment start. Symptom co-occurrence was measured by Jaccard index. A community detection algorithm was used to identify symptom clusters on the basis of a random walk process, and network visualizations were used to illustrate symptom dynamics. RESULTS: There were 6,429 presentations in the CMS symptom-defined cohort. The network analysis identified two distinct symptom clusters centered around pain and fever. In the expanded symptom cohort, there were 5,731 visits and six symptom clusters centered around fever, emesis/nausea, fatigue, deep vein thrombosis, pain, and ascites. For patients who newly initiated treatment, there were 1,154 visits and four symptom clusters centered around fever, nausea/emesis, fatigue, and deep vein thrombosis. CONCLUSION: Uncontrolled symptoms are associated with unplanned acute care. Recognition of the complexity of symptom co-occurrence can drive improved management strategies.


Assuntos
Antineoplásicos/efeitos adversos , Neoplasias/tratamento farmacológico , Assistência Ambulatorial , Ascite/induzido quimicamente , Institutos de Câncer , Análise por Conglomerados , Fadiga/induzido quimicamente , Feminino , Febre/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Dor/induzido quimicamente , Trombose Venosa/induzido quimicamente , Vômito/induzido quimicamente
11.
Obstet Gynecol ; 123(5): 1031-1037, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24785856

RESUMO

OBJECTIVE: To assess the direct costs of three surgical approaches in uterine cancer and the cost-effectiveness of incorporating robot-assisted surgery. METHODS: A cost system that allocates the actual cost of resources used to treat each patient, as opposed to borrowing cost data from a billing system, was used to determine direct costs for patients who underwent surgery for uterine cancer from 2009 to 2010. These costs included all aspects of surgical care up to 6 months after discharge. Total amortized direct costs included the capital cost of three dual-console robotic platforms with 5 years of service contracts. Nonamortized costs were also calculated (excluded capital costs). Modeling was performed to estimate the mean cost of surgical care for patients presenting with endometrial cancer from 2007 to 2010. RESULTS: Of 436 cases (132 laparoscopic, 262 robotic, 42 laparotomy), total mean amortized direct costs per case were $20,489 (laparoscopy), $23,646 (robot), and $24,642 (laparotomy) (P<.05 [robot compared with laparoscopy]; P=.6 [robot compared with laparotomy]). Total nonamortized costs per case were $20,289, $20,467, and $24,433, respectively (P=.9 [robot compared with laparoscopy]; P=.03 [robot compared with laparotomy]). The planned surgical approach in 2007 was laparoscopy, 68%; robot, 8%; and laparotomy, 24% compared with 26%, 64%, and 9%, respectively, in 2010 (P<.001). The modeled mean amortized direct costs per case were $21,738 in 2007 and $22,678 in 2010 (+$940). Nonamortized costs were $21,298 in 2007 and $20,573 in 2010 (-$725). CONCLUSION: Laparoscopy is least expensive when including capital acquisition costs. Laparoscopy and robotic surgery are comparable if upfront costs are excluded. There is cost neutralization with the robot when it helps decrease laparotomy rates.


Assuntos
Custos Diretos de Serviços , Laparoscopia/economia , Robótica/economia , Neoplasias Uterinas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise Custo-Benefício , Feminino , Humanos , Pessoa de Meia-Idade , Modelos Econômicos , Equipamentos Cirúrgicos/economia
12.
Front Microbiol ; 4: 169, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23801987

RESUMO

Thermal environments have island-like characteristics and provide a unique opportunity to study population structure and diversity patterns of microbial taxa inhabiting these sites. Strains having ≥98% 16S rRNA gene sequence similarity to the obligately anaerobic Firmicutes Thermoanaerobacter uzonensis were isolated from seven geothermal springs, separated by up to 1600 m, within the Uzon Caldera (Kamchatka, Russian Far East). The intraspecies variation and spatial patterns of diversity for this taxon were assessed by multilocus sequence analysis (MLSA) of 106 strains. Analysis of eight protein-coding loci (gyrB, lepA, leuS, pyrG, recA, recG, rplB, and rpoB) revealed that all loci were polymorphic and that nucleotide substitutions were mostly synonymous. There were 148 variable nucleotide sites across 8003 bp concatenates of the protein-coding loci. While pairwise F ST values indicated a small but significant level of genetic differentiation between most subpopulations, there was a negligible relationship between genetic divergence and spatial separation. Strains with the same allelic profile were only isolated from the same hot spring, occasionally from consecutive years, and single locus variant (SLV) sequence types were usually derived from the same spring. While recombination occurred, there was an "epidemic" population structure in which a particular T. uzonensis sequence type rose in frequency relative to the rest of the population. These results demonstrate spatial diversity patterns for an anaerobic bacterial species in a relative small geographic location and reinforce the view that terrestrial geothermal springs are excellent places to look for biogeographic diversity patterns regardless of the involved distances.

13.
Front Microbiol ; 3: 47, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22363325

RESUMO

Cultivation-independent studies have shown that taxa belonging to the "deep-sea hydrothermal vent euryarchaeota 2" (DHVE2) lineage are widespread at deep-sea hydrothermal vents. While this lineage appears to be a common and important member of the microbial community at vent environments, relatively little is known about their overall distribution and phylogenetic diversity. In this study, we examined the distribution, relative abundance, co-occurrence patterns, and phylogenetic diversity of cultivable thermoacidophilic DHVE2 in deposits from globally distributed vent fields. Results of quantitative polymerase chain reaction assays with primers specific for the DHVE2 and Archaea demonstrate the ubiquity of the DHVE2 at deep-sea vents and suggest that they are significant members of the archaeal communities of established vent deposit communities. Local similarity analysis of pyrosequencing data revealed that the distribution of the DHVE2 was positively correlated with 10 other Euryarchaeota phylotypes and negatively correlated with mostly Crenarchaeota phylotypes. Targeted cultivation efforts resulted in the isolation of 12 axenic strains from six different vent fields, expanding the cultivable diversity of this lineage to vents along the East Pacific Rise and Mid-Atlantic Ridge. Eleven of these isolates shared greater than 97% 16S rRNA gene sequence similarity with one another and the only described isolate of the DHVE2, Aciduliprofundum boonei T469(T). Sequencing and phylogenetic analysis of five protein-coding loci, atpA, EF-2, radA, rpoB, and secY, revealed clustering of isolates according to geographic region of isolation. Overall, this study increases our understanding of the distribution, abundance, and phylogenetic diversity of the DHVE2.

14.
Int J Syst Evol Microbiol ; 60(Pt 1): 67-71, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19648349

RESUMO

An obligately anaerobic, xylanolytic, extremely thermophilic bacterium, strain JW/HY-331(T), was isolated from sheep faeces collected from a farm at the University of Georgia, USA. Cells of strain JW/HY-331(T) stained Gram-positive and were catalase-negative, non-motile rods. Single terminal endospores (0.4-0.6 mum in diameter) swelled the mother cell. Growth ranges were 44-77 degrees C (optimum 70 degrees C at pH(70 degrees C) 7.2) and pH(70 degrees C) 5.9-8.6 (optimum 7.2 at 70 degrees C). Salt tolerance was 0-2.0 % (w/v) NaCl. No growth was observed at or below 42 degrees C or at or above 79 degrees C or at pH(70 degrees C) 5.7 and below or 8.9 and above. In the presence of 0.3 % yeast extract and 0.1 % tryptone, strain JW/HY-331(T) utilized xylose, glucose, galactose, cellobiose, raffinose and xylan as carbon and energy sources, but not dextran, soluble potato starch, CM-cellulose, cellulose powder, casein or Casamino acids. Fermentation products from glucose were lactate, acetate, ethanol, CO2 and H2. The G+C content of the genomic DNA was 45.4 mol% (HPLC). Major cellular fatty acids were iso-C(17 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). No respiratory quinones were detected. The cell-wall structure was a single layer (Gram-type positive) of the peptidoglycan type A1gamma; the cell-wall sugars were galactose and mannose. Based on 16S rRNA gene sequence analysis, 'Catabacter hongkongensis' HKU16 (85.4 % similarity), Caloramator fervidus ATCC 43204(T) (84.2 %) and Caloranaerobacter azorensis MV1087(T) (83.4 %) were the closest relatives, but they were only distantly related to strain JW/HY-331(T). On the basis of physiological, chemotaxonomic and phylogenetic data, isolate JW/HY-331(T) (=DSM 21659(T) =ATCC BAA-1711(T)) is proposed as the type strain of Caldicoprobacter oshimai gen. nov., sp. nov., placed in Caldicoprobacteraceae fam. nov. within the order Clostridiales of the phylum Firmicutes.


Assuntos
Fezes/microbiologia , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Anaerobiose , Animais , Composição de Bases , DNA Bacteriano/genética , DNA Ribossômico/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Bactérias Gram-Positivas/genética , Bactérias Gram-Positivas/metabolismo , Temperatura Alta , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Ovinos , Xilose/metabolismo
15.
Int J Syst Evol Microbiol ; 59(Pt 11): 2685-91, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19625440

RESUMO

An anaerobic thermophilic bacterium, designated strain JW/SA-NV4(T), was isolated from a xylan-supplemented enrichment culture from Trego hot spring located within the Black Rock Desert (NV, USA). Cells were generally straight or slightly bent rod-shaped, 0.4-0.8 microm in width and 3-6 microm in length during exponential growth. Cells from stationary phase were variable in size and shape, showing curved or bent morphology. Motility was not seen and flagella were not observed in electron micrographs. Sporulation was not observed. Strain JW/SA-NV4(T) stained Gram-negative but is phylogenetically Gram-type positive. Growth occurred at pH(25 degrees C) 6.8-8.8, with optimum growth at pH 8.4; no growth occurred at pH 9.0 or above or at 6.5 or below. With glucose or xylose as the carbon source, strain JW/SA-NV4(T) grew at 44-74 degrees C; no growth occurred at 76 degrees C or above or at 42 degrees C or below. However, the optimum temperature was 62 and 66 degrees C when grown on glucose and xylose, respectively. The shortest doubling time observed with glucose was approximately 4 h, and with xylose approximately 3.4 h. Strain JW/SA-NV4(T) tolerated an atmosphere containing up to 0.1 % O(2); no growth occurred at a gas atmosphere of 0.2 % O(2). Chemo-organotrophic growth occurred with xylose, glucose, mannose, xylan, pyruvate, fructose, ribose, Casamino acids, mannitol, tryptone, peptone, cellobiose and yeast extract. When grown in mineral media containing 1 g yeast extract l(-1) as an electron donor, thiosulfate and sulfur were reduced to sulfide. The G+C content of the DNA was 38.6 mol% (HPLC). 16S rRNA gene sequence analysis placed strain JW/SA-NV4(T) within the order Thermoanaerobacterales and within the Thermoanaerobacterales Incertae Sedis Family III, specifically between taxa classified within the genera Thermosediminibacter and Thermovenabulum. The closest phylogenetic neighbours were Thermosediminibacter oceani JW/IW-1228P(T) (94.2 % 16S rRNA gene sequence similarity) and Thermosediminibacter litoriperuensis JW/YJL-1230-7/2(T) (94.0 %) [Lee, Y.-J., Wagner, I. D., Brice, M. E., Kevbrin, V. V., Mills, G. L., Romanek, C. S. & Wiegel, J. (2005). Extremophiles 9, 375-383]. Based on physiological and genotypic characteristics, strain JW/SA-NV4(T) (=DSM 18802(T)=ATCC BAA-1454(T)) is proposed to represent the type strain of a novel species in a novel genus, Caldanaerovirga acetigignens gen. nov., sp. nov.


Assuntos
Álcalis/metabolismo , Bactérias/isolamento & purificação , Bactérias/metabolismo , Fontes Termais/microbiologia , Xilose/metabolismo , Anaerobiose , Bactérias/química , Bactérias/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Temperatura Alta , Dados de Sequência Molecular , Nevada , Filogenia , RNA Ribossômico 16S/genética
16.
Int J Syst Evol Microbiol ; 58(Pt 11): 2565-73, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18984694

RESUMO

Several strains of heterotrophic, anaerobic thermophilic bacteria were isolated from hot springs of the Uzon Caldera, Kamchatka, Far East Russia. Strain JW/IW010(T) was isolated from a hot spring within the West sector of the Eastern Thermal field, near Pulsating Spring in the Winding Creek area. Cells of strain JW/IW010(T) were straight to slightly curved rods, 0.5 mum in width and variable in length from 2 to 5 mum and occasionally up to 15 mum, and formed oval subterminal spores. Cells stained Gram-negative, but were Gram-type positive. Growth was observed between 32.5 and 69 degrees C with an optimum around 61 degrees C (no growth occurred at or below 30 degrees C, or at or above 72 degrees C). The pH(60 degrees C) range for growth was 4.2-8.9 with an optimum at 7.1 (no growth occurred at or below pH(60 degrees C) 3.9, or at 9.2 or above). The shortest observed doubling-time at pH(60 degrees C) 6.9 and 61 degrees C was 30 min. Strain JW/IW010(T) was chemo-organotrophic; yeast extract, peptone, Casamino acids and tryptone supported growth. Yeast extract was necessary for the utilization of non-proteinaceous substrates, and growth was observed with inulin, cellobiose, maltose, sucrose, glucose, fructose, galactose, mannose, xylose, trehalose, mannitol, pyruvate and crotonate. The G+C content of the genomic DNA of strain JW/IW010(T) was 33.6 mol% (HPLC method). The major phospholipid fatty acids were iso-15 : 0 (53.5 %), 15 : 0 (11.8 %), 16 : 0 (7.3 %), 10-methyl 16 : 0 (7.3 %) and anteiso-15 : 0 (5.3 %). 16S rRNA gene sequence analysis placed strain JW/IW010(T) in the genus Thermoanaerobacter of the family 'Thermoanaerobacteriaceae' (Firmicutes), with Thermoanaerobacter sulfurigignens JW/SL-NZ826(T) (97 % 16S rRNA gene sequence similarity) and Thermoanaerobacter kivui DSM 2030(T) (94.5 %) as the closest phylogenetic relatives with validly published names. The level of DNA-DNA relatedness between strain JW/IW010(T) and Thermoanaerobacter sulfurigignens JW/SL-NZ826(T) was 64 %. Based on the physiological, phylogenetic and genotypic data, strain JW/IW010(T) represents a novel taxon, for which the name Thermoanaerobacter uzonensis sp. nov. is proposed. The type strain is JW/IW010(T) (=ATCC BAA-1464(T)=DSM 18761(T)). The effectively published strain, 1501/60, of 'Clostridium uzonii' [Krivenko, V. V., Vadachloriya, R. M., Chermykh, N. A., Mityushina, L. L. & Krasilnikova, E. N. (1990). Microbiology (English translation of Mikrobiologiia) 59, 741-748] had approximately 88.0 % DNA-DNA relatedness with strain JW/IW010(T) and was included in the novel taxon.


Assuntos
Fontes Termais/microbiologia , Temperatura Alta , Thermoanaerobacter/classificação , Anaerobiose , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Ribossômico/genética , Ácidos Graxos/análise , Genes de RNAr , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA , Especificidade da Espécie , Thermoanaerobacter/genética , Thermoanaerobacter/isolamento & purificação , Thermoanaerobacter/fisiologia
17.
Extremophiles ; 9(5): 375-83, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15965715

RESUMO

A new group of anaerobic thermophilic bacteria was isolated from enrichment cultures obtained from deep sea sediments of Peru Margin collected during Leg 201 of the Ocean Drilling Program. A total of ten isolates were obtained from cores of 1-2 m below seafloor (mbsf) incubated at 60 degrees C: three isolates came from the sediment 426 m below sea level with a surface temperature of 9 degrees C (Site 1227), one from 252 m below sea level with a temperature of 12 degrees C (Site 1228), and six isolates under sulfate-reducing condition from the lower slope of the Peru Trench (Site 1230). Strain JW/IW-1228P from the Site 1228 and strain JW/YJL-1230-7/2 from the Site 1230 were chosen as representatives of the two identified clades. Based on the 16S rDNA sequence analysis, these isolates represent a novel group with Thermovenabulum and Caldanaerobacter as their closest relatives. The temperature range for growth was 52-76 degrees C with an optimum at around 68 degrees C for JW/IW-1228P and 43-76 degrees C with an optimum at around 64 degrees C for JW/YJL-1230-7/2. The pH(25C) range for growth was from 6.3 to 9.3 with an optimum at 7.5 for JW/IW-1228P and from 5 to 9.5 with an optimum at 7.9-8.4 for JW/YJL-1230-7/2. The salinity range for growth was from 0% to 6% (w/v) for JW/IW-1228P and from 0% to 4.5% (w/v) for JW/YJL-1230-7/2. The G+C [corrected] mol% of the genomic DNA was 46.3 +/- 0.7% (n = 4) for Thermosediminibacter oceani [corrected] JW/IW-1228PT [corrected] and 45.2 +/- 0.7 (n = 6) for Thermosediminibacter litoriperuensis [corrected] JW/YJL-1230-7/2T [corrected] DNA-DNA hybridization yielded 52% similarity between the two strains. According to 16S rRNA gene sequence analysis, the isolates are located within the family, Thermoanaerobacteriaceae. Based on their morphological and physiological properties and phylogenetic analysis, it is proposed that strain JW/IW-1228P(T) is placed into a novel taxa, Thermosediminibacter oceani, gen. nov., sp. nov. (DSM 16646(T)=ATCC BAA-1034(T)), and JW/YJL-1230-7/2(T) into Thermosediminibacter litoriperuensis sp. nov. (DSM 16647(T) =ATCC BAA-1035(T)).


Assuntos
Thermoanaerobacter/classificação , Thermoanaerobacter/isolamento & purificação , Anaerobiose , DNA Bacteriano/genética , Transporte de Elétrons , Ácidos Graxos/análise , Ácidos Graxos/química , Microscopia Eletrônica , Peru , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Especificidade por Substrato , Thermoanaerobacter/citologia , Thermoanaerobacter/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa