Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 82
Filtrar
1.
Intern Emerg Med ; 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38372885

RESUMEN

EDs restricted visitors during the COVID-19 pandemic on the assumption that the risks of disease spread outweighed the psychological benefits of liberal visitation. But data suggest that beyond providing emotional support, family and caregivers can clarify history, improve patient monitoring, and advocate for patients-actions that can improve quality of care. Our objective was to assess whether removing visitors from the bedside contributed to errors in emergency care. We reviewed a database of medical errors covering visits from 11/15/17 to 7/30/22 at an urban, tertiary-care, academic ED for five types of error amenable to visitor intervention: inadequate history gathering, inadequate monitoring, falls, giving a medication to which a patient is allergic, and inappropriate medication dosing. These records were reviewed by two investigators to determine the likelihood visitor presence could have prevented the error. For those errors judged susceptible to visitor intercession, the number in each category was compared for the period before and after strict restrictions took effect. Our review found 27/781 (3.5%) errors in the pre-pandemic period and 27/568 (4.8%) errors in the pandemic period fell into one of these five categories (p = 0.29). Visitors prevented harm from reaching the patient in three of 27 pre-pandemic errors (11.1%), compared to 0 out of 27 peri-pandemic errors (p = 0.23). On review by two attendings, 17/24 (70.8%) errors that reached the patient in the pre-pandemic period were judged amenable to visitor intervention, compared to 25/27 (92.6%) in the pandemic period (p = 0.09). There were no statistically significant differences in the categories of error between the two groups; monitoring errors came the closest: 1/17 (5.9%) pre-COVID errors amenable to visitor intervention in these categories were monitoring related, whereas 7/25 (28.0%) post-COVID errors were (p = 0.16). While this study did not demonstrate a statistically significant difference in error between lenient and restrictive visitation eras, we did find multiple cases in the pre-COVID era in which family presence prevented error, and qualitative review of post-COVID errors suggested many could have been prevented by family presence. Larger trials are needed to determine how frequent and consequential such errors are and how to balance the public health imperative of curbing disease spread with the harm caused by restricting visitation.

2.
Am J Emerg Med ; 77: 17-20, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38096635

RESUMEN

Rising length of stay and inpatient boarding in emergency departments have directly affected patient satisfaction and nearly all provider-to-patient care metrics. Prior studies suggest that ED observation has significant clinical and financial benefits including decreasing hospitalization and length of stay. ED observation is one method long employed to shorten ED length of stay and to free up inpatient beds, yet many patients continue to be admitted to the hospital with an average hospital length of stay of only one day. The objectives of this study were to evaluate whether vigorous tracking and provider reviews of one day hospital admits affected the utilization of ED observation and whether this correlated with significant change in rates of admission from observation status. Between September 2020 and May 2021, in a tertiary care hospital with an annual ED volume of 55,0000, chart reviews of 24-h inpatient discharges were initiated by two senior EM faculty to determine perceived suitability for ED observation. Non-punitive email reviews were then initiated with ED attending providers in order to encourage evaluation of whether these patients would have benefitted from being placed into observation. We then analyzed ED observation patient volumes and subsequent admission rates to the hospital from ED observation and compared these numbers to baseline ED observation volume and admission rates between September 2018 and May 2019. A total of 1448 reviews were conducted on 24-h discharges which correlated with an increase in utilization of ED observation from 11.77% (95% CI [11.62, 12.31]) of total ED volume in our control period to 14.21% (95% CI [13.84, 14.58]) during the study period. We found that the overall admission rate from ED observation increased from 20.12% (95% CI [18.97, 21.26]) baseline to 23.80% (95% CI [22.60, 25.00]) during the same time periods. Our data suggest that increasing the total number of patients placed into observation by 21% correlated with a relative increase in admission rates from ED observation by 18%. This would suggest that our efforts to potentially include more patients into our observation program led to a significant increase in subsequent admission rates. There is likely a balance that must be struck between under- and over-utilization of ED observation, and expanding ED observation may be an effective solution to hospital boarding and ED overcrowding.


Asunto(s)
Líquidos Corporales , Hospitalización , Humanos , Tiempo de Internación , Servicio de Urgencia en Hospital , Hospitales , Admisión del Paciente , Estudios Retrospectivos
3.
J Emerg Med ; 65(3): e250-e255, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37689413

RESUMEN

BACKGROUND: Error in emergency medicine remains common and difficult to identify. OBJECTIVE: To evaluate if questioning emergency physician reviewers as to whether or not they would have done something differently (Would you have done something differently? [WYHDSD]) can be a useful marker to identify error. METHODS: Prospective data were collected on all patients presenting to an academic emergency department (ED) between 2017 and 2021. All cases who met the following criteria were identified: 1) returned to ED within 72 h and admitted; 2) transferred to intensive care unit from floor within 24 h of admission; 3) expired within 24 h of arrival; or 4) patient or provider complaint. Cases were randomly assigned to emergency physicians and reviewed using an electronic tool to assess for error and adverse events. Reviewers were then mandated to answer WYHDSD in the management of the case. RESULTS: During the study period, 6672 cases were reviewed. Of the 5857 cases where reviewers would not have done something differently, 5847 cases were found to have no error. The question WYHDSD had a sensitivity of 97.4% in predicting error and a negative predictive value of 99.8%. CONCLUSION: There was a significantly higher rate of near misses, adverse events, and errors attributable to an adverse event in cases where the reviewer would have done something differently (WHDSD) compared with cases where they would not. Therefore, asking reviewers if they WHDSD could potentially be used as a marker to identify error and improve patient care in the ED.


Asunto(s)
Medicina de Emergencia , Médicos , Humanos , Estudios Prospectivos , Servicio de Urgencia en Hospital , Hospitalización
4.
J Am Coll Emerg Physicians Open ; 4(4): e13013, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37520081

RESUMEN

Emergency department (ED) crowding poses significant operational challenges to hospitals. One strategy to address these issues is the implementation of an ED observation (EDO) unit. EDO involves placing patients in observation status after their initial evaluation, allowing for continued assessment, treatment, and the determination of a safe disposition. This paper provides a comprehensive guide for ED leaders on the implementation of ED observation in their departments. It includes a checklist summarizing key implementation points, operational and financial considerations, staffing and location planning, patient selection, clinical care protocols, documentation and communication processes, securing buy-in from stakeholders, and outcome measurement. The guide also highlights the updated billing codes based on the 2023 updated Current Procedural Terminology (CPT) guidelines. Successful implementation of an EDO program has shown benefits such as improved patient flow, enhanced revenue generation, reduced costs, and comparable clinical outcomes. This guide aims to equip ED leaders with the necessary knowledge and tools to implement and manage an effective ED observation program in their departments, ultimately improving the overall efficiency of emergency care delivery.

6.
Am J Emerg Med ; 54: 228-231, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35182916

RESUMEN

BACKGROUND: There is a paucity of data looking at resident error or contrasting errors and adverse events among residents and attendings. This type of data could be vital in developing and enhancing educational curricula OBJECTIVES: Using an integrated, readily accessible electronic error reporting system the objective of this study is to compare the frequency and types of error and adverse events attributed to emergency medicine residents with those attributed to emergency medicine attendings. METHODS: Individual events were classified into errors and/or adverse events, and were attributed to one of three groups-residents only, attendings only, or both (if the event had both resident and attending involvement). Error and adverse events were also classified into five different categories of events-systems, documentation, diagnostic, procedural and treatment. The proportion of error events were compared between the residents only and the attendings only group using a one-sample test of proportions. Categorical variables were compared using Fisher's exact test. RESULTS: Of a total of 115 observed events over the 11-month data collection period, 96 (83.4%) were errors. A majority of these errors, 40 (41.7%), were attributed to both residents and attendings, 20 (20.8%) were attributed to residents only, and 36 (37.5%) were attributed to attendings only. Of the 19 adverse events, 14 (73.7%) were attributed to both residents and attendings, and 5 (26.3%) adverse events were attributed to attendings only. No adverse events were attributed solely to residents (Table 1). Excluding events attributed to both residents and attendings, there was a significant difference between the proportion of errors attributed to attendings only (64.3%, CI: 50.6, 76.0), and residents only (35.7%, CI: 24.0, 49.0), p = 0.03. (Table 2). There was no significant difference between the residents only and the attendings only group in the distribution of errors and adverse events (Fisher's exact, p = 0.162). (Table 2). There was no statistically significant difference between the two groups in errors that did not result in adverse events and the rate of errors proceeding to adverse events (Fisher's exact, p = 0.15). (Table 3). There was no statistically significant difference between the two groups in the distribution of the types of errors and adverse events (Fisher's exact, p = 0.09). Treatment related errors were the most common error types, for both the attending and the resident groups. CONCLUSIONS: Resident error, somewhat expectedly, is most commonly related to treatment interventions, and rarely is due to an individual resident mistake. Resident error instead seems to reflect concomitant error on the part of the attending. Error, in general as well as adverse events, are more likely to be attributed to an attending alone rather than to a resident.


Asunto(s)
Medicina de Emergencia , Internado y Residencia , Medicina de Emergencia/educación , Servicio de Urgencia en Hospital , Humanos
7.
Acad Emerg Med ; 29(2): 184-192, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34860436

RESUMEN

BACKGROUND: The Society for Academic Emergency Medicine Board of Directors convened a task force to elucidate the current state of workforce, operational, and educational issues being faced by academic medical centers related to advanced practice providers (APPs). The task force surveyed academic emergency department (ED) chairs and residency program directors (PDs). METHODS: The survey was distributed to the Association of Academic Chairs of Emergency Medicine (AACEM)-member chairs and their respective residency PDs in 2021. We surveyed 125 chairs with their self-identified PDs. The survey sampled hiring, state-independent practice laws, scope of practice, teaching and supervision, training opportunities, delegation of procedures between physician learners and APPs, and perceptions of the impact on resident and medical student education. RESULTS: Of the AACEM-member chairs identified, 73% responded and 47% of PDs responded. Most (98%) employ either physician assistants or nurse practitioners. Among responding departments, 86% report APPs working in fast-track settings, 80% work in the main ED, and 54% work in the waiting room. In 44% of departments, APPs and residents evaluate patients concurrently, and 2% of respondents reported that APPs manage high-acuity patients without attending involvement. Two-thirds of chairs believe that APPs contribute positively to the quality of patient care, while 44% believe that APPs contribute to the academic environment. One-third of PDs believe that the presence of APPs interferes with resident education. Although 75% of PDs believe that residents require training to work effectively with APPs in the ED, almost half (49%) report zero hours of training around APP supervision or collaborative skills. CONCLUSIONS: APPs are ubiquitous across academic EDs. Future research is required for academic ED leaders to balance physician and APP deployment across the academic ED within the context of patient care, resident education, institutional resources, professional development opportunities for APP staff, and standardization of APP EM training.


Asunto(s)
Medicina de Emergencia , Internado y Residencia , Enfermeras Practicantes , Asistentes Médicos , Centros Médicos Académicos , Medicina de Emergencia/educación , Humanos , Encuestas y Cuestionarios , Estados Unidos
9.
J Am Coll Emerg Physicians Open ; 1(5): 887-897, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33145537

RESUMEN

INTRODUCTION: The evaluation of peer-reviewed cases for error is key to quality assurance (QA) in emergency medicine, but defining error to ensure reviewer agreement and reproducibility remains elusive. The objective of this study was to create a consensus-based set of rules to systematically identify medical errors. METHODS: This is a prospective, observational study of all cases presented for peer review at an urban, tertiary care, academic medical center emergency department (ED) quality assurance (QA) committee between October 13, 2015, and September 14, 2016. Our hospital uses an electronic system enabling staff to self-identify QA issues for subsequent review. In addition, physician or patient complaints, 72-hour returns with admission, death within 24 hours, floor transfers to ICU < 24 hours, and morbidity and mortality conference cases are automatic triggers for review. Trained reviewers not involved in the patient's care use a structured 8-point Likert scale to assess for error and preventable or non-preventable adverse events. Cases where reviewers perceived a need for additional treatment, or that caused patient harm, are referred to a 20-member committee of emergency department leadership, attendings, residents, and nurses for consensus review. For this study, "rules" were proposed by the reviewers identifying the error and validated by consensus during each meeting. The committee then decided if a rule had been broken (error) or not broken (judgment call). If an error could not be phrased in terms of a rule broken, then it would not be considered an error. The rules were then evaluated by 2 reviewers and organized by theme into categories to determine common errors in emergency medicine. RESULTS: We identified 108 episodes of rules broken in 103 cases within a database of 920 QA reviewed cases. In cases where a rule was broken and therefore an error was scored, the following 5 major themes emerged: (1) not acquiring necessary information (eg, not completing a relevant physical exam), N = 33 (31%); (2) not acting on data that were acquired (eg, abnormal vital signs or labs), N = 25 (23%); (3) knowledge gaps by clinicians (eg, not knowing to reduce a hernia), N = 16 (15%); (4) communication gaps (eg, discharge instructions), N = 17 (16%); and (5) systems issues (eg, improper patient registration), N = 17 (16%). CONCLUSION: The development of consensus-based rules may result in a more standardized and practical definition of error in emergency medicine to be used as a QA tool and a basis for research. The most common type of rule broken was not acquiring necessary information. A rule-based definition of medical error in emergency medicine may identify key areas for risk reduction strategies, help standardize medical QA, and improve patient care and physician education.

10.
Rambam Maimonides Med J ; 11(4)2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32516112

RESUMEN

The practice of medicine forces medical practitioners to make difficult and challenging choices on a daily basis. On the one hand we are obligated to cure with every resource available, while on the other hand we put the patient at risk because our treatments are flawed. To understand the ethics of error in medicine, its moral value, and the effects, error must first be defined. However, definition of error remains elusive, and its incidence has been extraordinarily difficult to quantify. Yet, a health care system that acknowledges error as a consequence of normative ethical practice must create systems to minimize error. Error reduction, in turn, should attempt to decrease patient harm and improve the entire health care system. We discuss a number of ethical and moral considerations that arise from practicing medicine despite anticipated error.

12.
Ann Emerg Med ; 76(4): 454-458, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32461010

RESUMEN

STUDY OBJECTIVE: Single-payer health care is supported by most Americans, but the effect of single payer on any particular sector of the health care market has not been well explored. We examine the effect of 2 potential single-payer designs, Medicare for All and an alternative including Medicare and Medicaid, on total payments and out-of-pocket spending for treat-and-release emergency care (patients discharged after an emergency department [ED] visit). METHODS: We used the 2013 to 2016 Medical Expenditure Panel Survey to determine estimates of payments made for ED visits by insurance type, and the 2015 National Hospital Ambulatory Medical Care Survey to estimate the proportion of ED visits covered by each insurance type. RESULTS: We found that total payments were predicted to increase from $85.5 billion to $89.0 billion (range $81.3 to $99.8 billion) in the Medicare-only scenario and decrease to $79.4 billion (range $71.6 to $87.2 billion) under Medicare/Medicaid, whereas out-of-pocket costs were predicted to decrease from $116 per visit to $45 with Medicare and to $36 with Medicare/Medicaid. CONCLUSION: In this study of ED treat-and-release patients, a transition to a Medicare for All system may increase ED reimbursement and reduce consumer out-of-pocket costs, whereas a system that maintains Medicaid in addition to Medicare could reduce total payments for emergency care.


Asunto(s)
Servicios Médicos de Urgencia/economía , Medicare/tendencias , Mecanismo de Reembolso/tendencias , Servicios Médicos de Urgencia/métodos , Tratamiento de Urgencia/economía , Tratamiento de Urgencia/métodos , Encuestas de Atención de la Salud/estadística & datos numéricos , Humanos , Estados Unidos
13.
Emerg Med Clin North Am ; 38(2): 297-310, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32336326

RESUMEN

Burnout is a work-related condition. Although stress may be a part of emergency medicine, excessive levels of chronic stress can lead to maladaptive behaviors and burnout. Burnout can lead to decreased physician longevity and performance and poorer patient outcomes. The first step is recognizing burnout in providers. Efforts can then be made to identify modifiable or unnecessary sources of stress to help reduce chronic stress and burnout. Solutions should be found to eliminate or ameliorate individual-level and system-level sources of stress.


Asunto(s)
Agotamiento Profesional/prevención & control , Medicina de Emergencia , Médicos/psicología , Agotamiento Profesional/etiología , Agotamiento Profesional/psicología , Humanos
14.
Am J Emerg Med ; 38(8): 1658-1661, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31787443

RESUMEN

BACKGROUND: Morbidity and Mortality (M&M) rounds are peer review conferences during which cases with adverse outcomes and difficult management decisions are presented. Their primary objective is to learn from complications and errors, modify behavior and judgment based on previous experiences, and prevent repetition of errors leading to complications. The objective of this study was to determine if M&M conferences can reduce repetitive error making demonstrated by a shift of the incidence of cases presented at M&M by chief complaint (CC) and experience of attendings. METHODS: All M&M cases from 1/1/2014-12/31/2017 derived from an urban, tertiary referral Emergency Department were reviewed and grouped into 12 different CC categories and by attending years of experience (1-4, 5-9 and 10+). Number and percent of M&M cases by CC and years of attending experience were calculated by year and a chi-squared analysis was performed. RESULTS: 350 M&M cases were presented over the four-year study period. There was a significant difference between CC categories from year-to-year (p < 0.001). Attendings with 1-4 years of experience had the majority of cases (46.3%), while those with 5-9 years had the fewest total cases (15.1%, p < 0.001). CONCLUSIONS: There was a persistent significant difference across CC categories of M&M cases from year-to-year, with down-trending and up-trending of specific CCs suggesting that M&M presentation may prevent repetitive errors. Newer attendings show increased rates of M&M cases relative to more experienced attendings. There may be a distinctive educational benefit of participation at M&M for attendings with fewer than five years of clinical experience.


Asunto(s)
Medicina de Emergencia , Rondas de Enseñanza , Medicina de Emergencia/educación , Medicina de Emergencia/métodos , Humanos , Errores Médicos/prevención & control , Errores Médicos/estadística & datos numéricos , Morbilidad , Mortalidad , Rondas de Enseñanza/métodos , Centros de Atención Terciaria
15.
mSystems ; 4(6)2019 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-31796563

RESUMEN

Wetland soils are one of the largest natural contributors to the emission of methane, a potent greenhouse gas. Currently, microbial contributions to methane emissions from these systems emphasize the roles of acetoclastic and hydrogenotrophic methanogens, while less frequently considering methyl-group substrates (e.g., methanol and methylamines). Here, we integrated laboratory and field experiments to explore the potential for methylotrophic methanogenesis in Old Woman Creek (OWC), a temperate freshwater wetland located in Ohio, USA. We first demonstrated the capacity for methylotrophic methanogenesis in these soils using laboratory soil microcosms amended with trimethylamine. However, subsequent field porewater nuclear magnetic resonance (NMR) analyses to identify methanogenic substrates failed to detect evidence for methylamine compounds in soil porewaters, instead noting the presence of the methylotrophic substrate methanol. Accordingly, our wetland soil-derived metatranscriptomic data indicated that methanol utilization by the Methanomassiliicoccaceae was the likely source of methylotrophic methanogenesis. Methanomassiliicoccaceae relative contributions to mcrA transcripts nearly doubled with depth, accounting for up to 8% of the mcrA transcripts in 25-cm-deep soils. Longitudinal 16S rRNA amplicon and mcrA gene surveys demonstrated that Methanomassiliicoccaceae were stably present over 2 years across lateral and depth gradients in this wetland. Meta-analysis of 16S rRNA sequences similar (>99%) to OWC Methanomassiliicoccaceae in public databases revealed a global distribution, with a high representation in terrestrial soils and sediments. Together, our results demonstrate that methylotrophic methanogenesis likely contributes to methane flux from climatically relevant wetland soils.IMPORTANCE Understanding the sources and controls on microbial methane production from wetland soils is critical to global methane emission predictions, particularly in light of changing climatic conditions. Current biogeochemical models of methanogenesis consider only acetoclastic and hydrogenotrophic sources and exclude methylotrophic methanogenesis, potentially underestimating microbial contributions to methane flux. Our multi-omic results demonstrated that methylotrophic methanogens of the family Methanomassiliicoccaceae were present and active in a freshwater wetland, with metatranscripts indicating that methanol, not methylamines, was the likely substrate under the conditions measured here. However, laboratory experiments indicated the potential for other methanogens to become enriched in response to trimethylamine, revealing the reservoir of methylotrophic methanogenesis potential residing in these soils. Collectively, our approach used coupled field and laboratory investigations to illuminate metabolisms influencing the terrestrial microbial methane cycle, thereby offering direction for increased realism in predictive process-oriented models of methane flux in wetland soils.

16.
J Emerg Med ; 57(5): e161-e165, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31594743

RESUMEN

Postgraduate training in emergency medicine (EM) varies in length among different programs. This fact creates a dilemma for applicants to the specialty of EM and prevents EM educators from reaching a consensus regarding the optimal length of training. Historically, EM training existed in the postgraduate year (PGY) 1-3, 2-4, and 1-4 formats, until the PGY 2-4 program became obsolete in 2011-2012. Currently, three-quarters of EM programs follow the PGY 1-3 format. In this article, we clarify for the applicants the main differences between the PGY 1-3 and PGY 1-4 formats. We also discuss the institutional, personal, and graduate considerations that explain why an institution or an individual would choose one format over the other.


Asunto(s)
Medicina de Emergencia/educación , Internado y Residencia/métodos , Factores de Tiempo , Curriculum/normas , Curriculum/tendencias , Educación de Postgrado en Medicina/métodos , Educación de Postgrado en Medicina/normas , Medicina de Emergencia/métodos , Humanos , Internado y Residencia/normas , Enseñanza/psicología , Enseñanza/normas
17.
West J Emerg Med ; 20(2): 250-255, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30881544

RESUMEN

INTRODUCTION: In an age of increasing scrutiny of each hospital admission, emergency department (ED) observation has been identified as a low-cost alternative. Prior studies have shown admission rates for syncope in the United States to be as high as 70%. However, the safety and utility of substituting ED observation unit (EDOU) syncope management has not been well studied. The objective of this study was to evaluate the safety of EDOU for the management of patients presenting to the ED with syncope and its efficacy in reducing hospital admissions. METHODS: This was a prospective before-and-after cohort study of consecutive patients presenting with syncope who were seen in an urban ED and were either admitted to the hospital, discharged, or placed in the EDOU. We first performed an observation study of syncope management and then implemented an ED observation-based management pathway. We identified critical interventions and 30-day outcomes. We compared proportions of admissions and adverse events rates with a chi-squared or Fisher's exact test. RESULTS: In the "before" phase, 570 patients were enrolled, with 334 (59%) admitted and 27 (5%) placed in the EDOU; 3% of patients discharged from the ED had critical interventions within 30 days and 10% returned. After the management pathway was introduced, 489 patients were enrolled; 34% (p<0.001) of pathway patients were admitted while 20% were placed in the EDOU; 3% (p=0.99) of discharged patients had critical interventions at 30 days and 3% returned (p=0.001). CONCLUSION: A focused syncope management pathway effectively reduces hospital admissions and adverse events following discharge and returns to the ED.


Asunto(s)
Unidades de Observación Clínica/estadística & datos numéricos , Servicio de Urgencia en Hospital/organización & administración , Síncope/terapia , Unidades de Observación Clínica/organización & administración , Estudios de Cohortes , Vías Clínicas/estadística & datos numéricos , Utilización de Instalaciones y Servicios , Femenino , Hospitalización/estadística & datos numéricos , Hospitales de Enseñanza/estadística & datos numéricos , Hospitales Urbanos/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Alta del Paciente/estadística & datos numéricos , Estudios Prospectivos , Estados Unidos
18.
Nat Microbiol ; 4(2): 352-361, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30510171

RESUMEN

The deep terrestrial biosphere harbours a substantial fraction of Earth's biomass and remains understudied compared with other ecosystems. Deep biosphere life primarily consists of bacteria and archaea, yet knowledge of their co-occurring viruses is poor. Here, we temporally catalogued viral diversity from five deep terrestrial subsurface locations (hydraulically fractured wells), examined virus-host interaction dynamics and experimentally assessed metabolites from cell lysis to better understand viral roles in this ecosystem. We uncovered high viral diversity, rivalling that of peatland soil ecosystems, despite low host diversity. Many viral operational taxonomic units were predicted to infect Halanaerobium, the dominant microorganism in these ecosystems. Examination of clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins (CRISPR-Cas) spacers elucidated lineage-specific virus-host dynamics suggesting active in situ viral predation of Halanaerobium. These dynamics indicate repeated viral encounters and changing viral host range across temporally and geographically distinct shale formations. Laboratory experiments showed that prophage-induced Halanaerobium lysis releases intracellular metabolites that can sustain key fermentative metabolisms, supporting the persistence of microorganisms in this ecosystem. Together, these findings suggest that diverse and active viral populations play critical roles in driving strain-level microbial community development and resource turnover within this deep terrestrial subsurface ecosystem.


Asunto(s)
Bacteriófagos/fisiología , Firmicutes/crecimiento & desarrollo , Firmicutes/virología , Consorcios Microbianos , Yacimiento de Petróleo y Gas/microbiología , Yacimiento de Petróleo y Gas/virología , Bacteriófagos/clasificación , Bacteriófagos/genética , Biodiversidad , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Firmicutes/clasificación , Firmicutes/genética , Fracking Hidráulico , Metagenoma , Consorcios Microbianos/genética , Activación Viral
19.
mBio ; 9(6)2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30401770

RESUMEN

Microbial carbon degradation and methanogenesis in wetland soils generate a large proportion of atmospheric methane, a highly potent greenhouse gas. Despite their potential to mitigate greenhouse gas emissions, knowledge about methane-consuming methanotrophs is often limited to lower-resolution single-gene surveys that fail to capture the taxonomic and metabolic diversity of these microorganisms in soils. Here our objective was to use genome-enabled approaches to investigate methanotroph membership, distribution, and in situ activity across spatial and seasonal gradients in a freshwater wetland near Lake Erie. 16S rRNA gene analyses demonstrated that members of the methanotrophic Methylococcales were dominant, with the dominance largely driven by the relative abundance of four taxa, and enriched in oxic surface soils. Three methanotroph genomes from assembled soil metagenomes were assigned to the genus Methylobacter and represented the most abundant methanotrophs across the wetland. Paired metatranscriptomes confirmed that these Old Woman Creek (OWC) Methylobacter members accounted for nearly all the aerobic methanotrophic activity across two seasons. In addition to having the capacity to couple methane oxidation to aerobic respiration, these new genomes encoded denitrification potential that may sustain energy generation in soils with lower dissolved oxygen concentrations. We further show that Methylobacter members that were closely related to the OWC members were present in many other high-methane-emitting freshwater and soil sites, suggesting that this lineage could participate in methane consumption in analogous ecosystems. This work contributes to the growing body of research suggesting that Methylobacter may represent critical mediators of methane fluxes in freshwater saturated sediments and soils worldwide.IMPORTANCE Here we used soil metagenomics and metatranscriptomics to uncover novel members within the genus Methylobacter We denote these closely related genomes as members of the lineage OWC Methylobacter Despite the incredibly high microbial diversity in soils, here we present findings that unexpectedly showed that methane cycling was primarily mediated by a single genus for both methane production ("Candidatus Methanothrix paradoxum") and methane consumption (OWC Methylobacter). Metatranscriptomic analyses revealed that decreased methanotrophic activity rather than increased methanogenic activity possibly contributed to the greater methane emissions that we had previously observed in summer months, findings important for biogeochemical methane models. Although members of this Methylococcales order have been cultivated for decades, multi-omic approaches continue to illuminate the methanotroph phylogenetic and metabolic diversity harbored in terrestrial and marine ecosystems.


Asunto(s)
Metano/metabolismo , Methylobacteriaceae/metabolismo , Microbiología del Suelo , Suelo/química , Humedales , ADN Bacteriano/genética , Agua Dulce , Perfilación de la Expresión Génica , Genoma Bacteriano , Metagenómica , Methylobacteriaceae/genética , Ohio , Oxidación-Reducción , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
20.
Environ Microbiol ; 20(12): 4596-4611, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30394652

RESUMEN

About 60% of natural gas production in the United States comes from hydraulic fracturing of unconventional reservoirs, such as shales or organic-rich micrites. This process inoculates and enriches for halotolerant microorganisms in these reservoirs over time, resulting in a saline ecosystem that includes methane producing archaea. Here, we survey the biogeography of methanogens across unconventional reservoirs, and report that members of genus Methanohalophilus are recovered from every hydraulically fractured unconventional reservoir sampled by metagenomics. We provide the first genomic sequencing of three isolate genomes, as well as two metagenome assembled genomes (MAGs). Utilizing six other previously sequenced isolate genomes and MAGs, we perform comparative analysis of the 11 genomes representing this genus. This genomic investigation revealed distinctions between surface and subsurface derived genomes that are consistent with constraints encountered in each environment. Genotypic differences were also uncovered between isolate genomes recovered from the same well, suggesting niche partitioning among closely related strains. These genomic substrate utilization predictions were then confirmed by physiological investigation. Fine-scale microdiversity was observed in CRISPR-Cas systems of Methanohalophilus, with genomes from geographically distinct unconventional reservoirs sharing spacers targeting the same viral population. These findings have implications for augmentation strategies resulting in enhanced biogenic methane production in hydraulically fractured unconventional reservoirs.


Asunto(s)
Fracking Hidráulico , Methanosarcinaceae/fisiología , Ecosistema , Genoma Bacteriano , Metagenoma , Methanosarcinaceae/genética , Gas Natural , Yacimiento de Petróleo y Gas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...