Deciphering the Catalytic Mechanism of Virginiamycin B Lyase with Multiscale Methods and Molecular Dynamics Simulations.

Due to the emergence of antibiotic resistance, the need to explore novel antibiotics and/or novel strategies to counter antibiotic resistance is of utmost importance. In this work, we explored the molecular and mechanistic details of the degradation of a streptogramin B antibiotic by virginiamycin B (Vgb) lyase of Staphylococcus aureus using classical molecular dynamics simulations and multiscale quantum mechanics/molecular mechanics methods. Our results were in line with available experimental kinetic information. Although we were able to identify a stepwise mechanism, in the wild-type enzyme, the intermediate is short-lived, showing a small barrier to decay to the product state. The impact of point mutations on the reaction was also assessed, showing not only the importance of active site residues to the reaction catalyzed by Vgb lyase but also of near positive and negative residues surrounding the active site. Using molecular dynamics simulations, we also predicted the most likely protonation state of the 3-hydroxypicolinic moiety of the antibiotic and the impact of mutants on antibiotic binding. All this information will expand our understanding of linearization reactions of cyclic antibiotics, which are crucial for the development of novel strategies that aim to tackle antibiotic resistance.

The genus Bradleya Hornibrook, 1952 (Crustacea: Ostracoda) in South America and adjacent oceanic areas, with description of a new bradleyine genus.

The ostracod genus Bradleya Hornibrook is an important taxon of Cenozoic assemblages, occurring practically in all oceanic regions. The wide distribution both in shallow and deep waters turns Bradleya interesting for studies involving phylogeny and paleoceanography. The present work aims at the study of fossil and recent species in South America and adjacent regions, based on bibliographic review and the restudy of samples from the Brazilian continental margin, the Navidad Formation (lower Miocene) and El Peral Beds (meso-upper Miocene), both cropping out in the Central Chile. The chronostratigraphic, (paleo)bathymetric and (paleo)zoogeographic distribution of the species is reviewed and updated. The bridge composition was studied in all species recorded and revealed to be important taxonomic character. The taxa identified were gathered into three morphological groups: two proposed previously (i.e., the dictyon-group and the arata-group) and a new one in the present work (i.e., the normani-group). The dictyon-group and the arata-group gather deep-sea species, while the normani-group is predominantly neritic, including most of the species of Brazilian margin. Bradleya victorjarai sp. nov. is proposed for the Miocene of Chile, and Bradleya ybate (Bergue et al.) is reassigned to Rigracythere gen. nov. Questionable or misidentified species ascribed to Bradleya are briefly discussed.

Predicting hospital emergency department visits accurately: A systematic review.

OBJECTIVES: The emergency department (ED) is a very important healthcare entrance point, known for its challenging organisation and management due to demand unpredictability. An accurate forecast system of ED visits is crucial to the implementation of better management strategies that optimise resources utilization, reduce costs and improve public confidence. The aim of this review is to investigate the different factors that affect the ED visits forecasting outcomes, in particular the predictive variables and type of models applied. METHODS: A systematic search was conducted in PubMed, Web of Science and Scopus. The review methodology followed the PRISMA statement guidelines. RESULTS: Seven studies were selected, all exploring predictive models to forecast ED daily visits for general care. MAPE and RMAE were used to measure models' accuracy. All models displayed good accuracy, with errors below 10%. CONCLUSIONS: Model selection and accuracy was found to be particularly sensitive to the ED dimension. While ARIMA-based and other linear models have good performance for short-time forecast, some machine learning methods proved to be more stable when forecasting multiple horizons. The inclusion of exogenous variables was found to be advantageous only in bigger EDs.

Different Enzyme Conformations Induce Different Mechanistic Traits in HIV-1 Protease.

The influence of the dynamical flexibility of enzymes on reaction mechanisms is a cornerstone in biological sciences. In this study, we aim to 1) study the convergence of the activation free energy by using the first step of the reaction catalysed by HIV-1 protease as a case study, and 2) provide further evidence for a mechanistic divergence in this enzyme, as two different reaction pathways were seen to contribute to this step. We used quantum mechanics/molecular mechanics molecular dynamics simulations, on four different initial conformations that led to different barriers in a previous study. Despite the sampling, the four activation free energies still spanned a range of 5.0 kcal ⋅ mol-1 . Furthermore, the new simulations did confirm the occurrence of an unusual mechanistic divergence, with two different mechanistic pathways displaying equivalent barriers. An active-site water molecule is proposed to influence the mechanistic pathway.

Transmembrane Protease Serine 2 Proteolytic Cleavage of the SARS-CoV-2 Spike Protein: A Mechanistic Quantum Mechanics/Molecular Mechanics Study to Inspire the Design of New Drugs To Fight the COVID-19 Pandemic.

Despite the development of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, there is an urgent need for efficient drugs to treat infected patients. An attractive drug target is the human transmembrane protease serine 2 (TMPRSS2) because of its vital role in the viral infection mechanism of SARS-CoV-2 by activation of the virus spike protein (S protein). Having in mind that the information derived from quantum mechanics/molecular mechanics (QM/MM) studies could be an important tool in the design of transition-state (TS) analogue inhibitors, we resorted to adiabatic QM/MM calculations to determine the mechanism of the first step (acylation) of proteolytic cleavage of the S protein with atomistic details. Acylation occurred in two stages: (i) proton transfer from Ser441 to His296 concerted with the nucleophilic attack of Ser441 to the substrate's P1-Arg and (ii) proton transfer from His296 to the P1'-Ser residue concerted with the cleavage of the ArgP1-SerP1' peptide bond, with a Gibbs activation energy of 17.1 and 15.8 kcal mol-1, relative to the reactant. An oxyanion hole composed of two hydrogen bonds stabilized the rate-limiting TS by 8 kcal mol-1. An analysis of the TMPRSS2 interactions with the high-energy, short-lived tetrahedral intermediate highlighted the limitations of current clinical inhibitors and pointed out specific ways to develop higher-affinity TS analogue inhibitors. The results support the development of more efficient drugs against SARS-CoV-2 using a human target, free from resistance development.

Functional, biochemical and molecular impact of sediment plumes from deep-sea mining on Mytilus galloprovincialis under hyperbaric conditions.

The deep-sea is the biggest ecosystem in the world and despite the extreme conditions that characterize it, is highly biodiverse and complex. Deep-sea mining has been foreseen as a potential and concerning new stressor, and among the deep-sea mining associated stressors, sediment plumes, likely to be released into the water column as a side effect of mining, can reach habitats within a radius of more than a hundred kilometers. The present study examined the effects of suspended sediments of different grain sizes (63-125 µm, 125-250 µm and 250-500 µm) in the model species Mytilus galloprovincialis, at 4 bar, as a proxy to address the potential effects of sediment plumes, in the water column, with different grain sizes under high pressure conditions. Functional (filtration rate - FR), biochemical (catalase - CAT, glutathione s-transferase - GST, lipid peroxidation - LPO) and molecular (gene expression of [actin (ACTN), glutathione S-transferase alpha (GSTA), superoxide dismutase 2 (SOD2), catalase (CAT), heat shock protein 60 (HSP60), cytochrome c oxidase (COI) and DNA mismatch repair protein (MSH6)]) endpoints were studied in juvenile organisms. The FR decreased significantly for all tested grain size ranges, with a more severe effect for the particles with a diameter between 63 and 125 µm. In addition to the FR, significant changes were also observed for all tested biomarkers. Gene expression was significantly downregulated for CAT and ACTN. Overall, this study demonstrated that the smaller sized particles are the ones leading to more severe effects. Given their high dispersion potential and longer suspension periods under mining operation scenarios, particular attention should be given to the release of sediment plumes that may affect deep-sea environments and the water column. It is, therefore, vital to create standards and guidelines for sustainable mining practices.

Antibiotic use in patients with COVID-19: a 'snapshot' Infectious Diseases International Research Initiative (ID-IRI) survey.

BACKGROUND: Antibiotics may be indicated in patients with COVID-19 due to suspected or confirmed bacterial superinfection. OBJECTIVES: To investigate antibiotic prescribing practices in patients with COVID-19. METHODS: We performed an international web-based survey and investigated the pattern of antibiotic use as reported by physicians involved in treatment of COVID-19. SPSS Statistics version 25 was used for data analysis. RESULTS: The survey was completed by 166 participants from 23 countries and 82 different hospitals. Local guidelines for antibiotic use in COVID-19 patients were reported by 61.8% (n = 102) of participants and for 82.9% (n = 136) they did not differ from local community-acquired pneumonia guidelines. Clinical presentation was recognized as the most important reason for the start of antibiotics (mean score = 4.07 and SD = 1.095 on grading scale from 1 to 5). When antibiotics were started, most respondents rated as the highest the need for coverage of atypical pathogens (mean score = 2.8 and SD = 0.99), followed by Staphylococcus aureus (mean score = 2.67 and SD = 1.05 on bi-modal scale, with values 1 and 2 for disagreement and values 3 and 4 for agreement). In the patients on the ward, 29.1% of respondents chose not to prescribe any antibiotic. Combination of ß-lactams and macrolides or fluoroquinolones was reported by 52.4% (n = 87) of respondents. In patients in the ICU, piperacillin/tazobactam was the most commonly prescribed antibiotic. The mean reported duration of antibiotic treatment was 7.12 (SD = 2.44) days. CONCLUSIONS: The study revealed widespread broad-spectrum antibiotic use in patients with COVID-19. Implementation of antimicrobial stewardship principles is warranted to mitigate the negative consequences of antibiotic therapy.

Levels of evidence supporting clinical practice guidelines on invasive aspergillosis.

Invasive aspergillosis (IA) is a severe life-threatening infection with challenges in therapy. The aim was to evaluate the level of evidence (LOE) supporting recommendations in clinical practice guidelines (CPGs) of IA and changes over time. Search on CPG on IA released between 2000 and 2019 was done. Last versions were evaluated and compared with previous versions. Recommendations were classified by LOE as A (multiple randomized controlled trial (RCT) or meta-analysis), B (data from a single RCT or observational studies), or C (observational studies with limitations, case series, or expert opinion). Diagnosis recommendations were excluded. Five CPG from three groups of scientific societies were identified: the 2016 Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS), 2017 European Society of Clinical Microbiology Infectious Diseases/European Confederation of Medical Mycology/European Respiratory Society (ESCMID/ECMM/ERS), 2018 Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) CPGs, and their previous versions (2008 IDSA/ATS and 2011 GEMICOMED/SEIMC). ECMID/ECMM/ERS have not published any previous version. From 511 recommendations analyzed, 80 were classified as LOE A (15.7%), 223 LOE B (43.6%), and 208 LOE C (40.7%). Among 238 strong recommendations, only 57 (24.0%) were supported by LOE A. When comparing recent CPGs with previous versions, the proportion of recommendations supported by LOE A did not significantly increase over time (IDSA/ATS: 13.3% [2016] vs. 14.8% [2008], p = 0.798; and SEIMC: 22.6% [2018] vs. 19% [2011], p = 0.568). In conclusion, IA is a condition with an urgent unmet clinical need for more high-quality randomized trials.

Evidence supporting recommendations from international guidelines on treatment, diagnosis, and prevention of HAP and VAP in adults.

Clinical practice guidelines (CPGs) are intended to support clinical decisions and should be based on high-quality evidence. The objective of the study was to evaluate the quality of evidence supporting the recommendations issued in CPGs for therapy, diagnosis, and prevention of hospital-acquired and ventilator-associated pneumonia (HAP/VAP). CPGs released by international scientific societies after year 2000, using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology, were analyzed. Number and strength of recommendations and quality of evidence (high, moderate, low, and very low) were extracted and indexed in the aforementioned sections. High-quality evidence was based on randomized control trials (RCT) without important limitations and exceptionally on rigorous observational studies. Eighty recommendations were assessed, with 7 (8.7%), 24 (30.0%), 29 (36.3%), and 20 (25.0%) being supported by high, moderate, low, and very low-quality evidence, respectively. Highest evidence degree was reported for 26 prevention recommendations, with 7 (26.9%) supported by high-quality evidence and no recommendation based on very low-quality evidence. In contrast, among 9 recommendations for diagnosis and 45 for therapy, none was supported by high-quality evidence, in spite of being recommended as strong in 33.3% and 46.7%, respectively. Among HAP/VAP diagnosis recommendations, the majority of evidence was rated as low or very low-quality (55.6% and 22.2%, respectively) whereas among HAP/VAP therapy recommendations, 4/5 were rated as low and very low-quality (40% each). In conclusion, among HAP/VAP international guidelines, most recommendations, particularly in therapy, remain supported by observational studies, case reports, and expert opinion. Well-designed RCTs are urgently needed.

Levels of evidence supporting European and American community-acquired pneumonia guidelines.

Optimal clinical decisions should be supported by clinical practice guidelines (CPG) based on evidence generated from randomized clinical trials (RCT). We aimed to evaluate the class and level of evidence (LOE) supporting the international community-acquired pneumonia (CAP) guidelines and their variation over time. The 2019 Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) and the 2011 European Respiratory Society/European Society Clinical Microbiology Infectious Diseases (ERS/ESCMID) CPG and its immediate predecessors (2007 and 2005) were evaluated. The number of recommendations and distribution as LOE A (supported by multiple RCT or a single, large RCT), B (supported by data from a single RCT or observational studies) and C (expert opinion, case studies, or standard of care) was identified. Overall, recommendations for diagnosis, management, and prevention were graded as strong in 51.4%, 62.9%, and 23.5% in spite that they were supported by LOE A in 5.7%, 11.1%, and 52.9%, respectively. In the 2019 ATS/IDSA guidelines (39 recommendations), 7.7% (n = 3) recommendations were classified as LOE A, 30.8% (n = 12) as LOE B, and 61.5% (24%) as LOE C. Across the 2011 ERS/ESCMID guidelines (68 recommendations), 21.2% (n = 14) recommendations were classified as LOE A, 4.6% (n = 3) as LOE B, and 74.2% (n = 49) as LOE C. When comparing with prior versions, the proportion of recommendations that were LOE A did not significantly increase in ERS/ESCMID (21.2% vs 20%) and decreased in ATS/IDSA (7.7% vs 32.0%). In conclusion, large randomized trials or network meta-analysis including comparison of regimens to identify high probability of best cure and mortality is an unmet clinical need on CAP.

Ventilator-associated pneumonia diagnosis: a prioritization exercise based on multi-criteria decision analysis.

The aim was to provide global experts ranking on priorities in diagnostic tools for VAP in clinical practice. A multiple criteria decision analysis (MCDA) was performed to identify diagnosis tools for VAP diagnosis. Priority factors were identified after literature review. An international, multidisciplinary expert panel reviewed variables and ranked diagnostic tools. Experts from ten European hospitals participated. Regarding bedside clinical practices, seven required chest X-ray use in all patients, whereas six reported the use of blood cultures and endotracheal aspirate in all patients. Invasive techniques were routinely performed in seven sites. CRP, PCT, and Gram stains were performed in all patients by 5, 2, and 8, respectively. Impact on patient outcomes, safety, and impact on the decision to start antibiotic therapy were ranked as the top three relevant concerns (7.7/10, 7/10, and 6.9/10, respectively). Chest X-ray was ranked as the most important imaging technique to diagnose VAP (score 251.7). Apart from blood cultures, endotracheal aspirate culture was identified as the main collection method for the microbiological testing (scores of 274.8 and 246.8, respectively). Mini-BAL was the preferred invasive technique with a score of 208. Top three biomarkers were CRP (score 184.3), PCT (181.3), and WBC (166.4). Gram stain (192.5) was prioritized among laboratory diagnostic techniques. Using MCDA, it is recommended to perform a combination of diagnostic techniques including images (chest X-ray), culture of clinical specimens (blood cultures and endotracheal aspirate), and biomarkers (CRP or PCT) for VAP diagnosis at the bedside. Gram stain was ranked as the preferred laboratory technique.

Is the dendritic organ of the striped eel catfish Plotosus lineatus an ammonia excretory organ?

The dendritic organ (DO) is a salt secretory organ in the Plotosidae marine catfishes. The potential role of the DO in ammonia excretion was investigated by examining the effects of salinity [brackishwater (BW 3‰), seawater (SW 34‰) and hypersaline water (HSW 60‰)] acclimation and DO ligation on ammonia excretion and ammonia transporter expression by immunohistochemistry (IHC), immunoblotting (IB) and qPCR. Ammonia flux rates (JAmm) were significantly lower in BW compared to SW and HSW. DO ligation resulted in a significantly lower JAmm in SW but not BW fish. IHC demonstrated apical and basolateral localization of Rhesus-associated glycoprotein (Rhag-like) and Rhbg-like proteins, respectively, in parenchymal cells of the DO acini. In the gills, which are the primary site of ammonia excretion in teleost fishes, IHC showed an apical localization of Rhag-like protein in some Na+/K+-ATPase (NKA) immunoreactive (IR) cells limited to a few interlamellar regions of the filament and, in both apical and basolateral membranes of pillar cells irrespective of treatment group. In gills, the distribution of NKA-IR cells showed no salinity and/or ligation dependency. IB of Rhag and Rhbg-like proteins was found only in the gills and expression levels did not change with salinity but ligation in BW decreased Rhbg-like levels. Although Rhcg was not detected with heterologous antibodies, rhcg1 mRNA expression was detected in both gills and DO. HSW was associated with the lowest expression in DO and ligations in SW and BW were without effect on branchial expression levels. Taken together these results indicate the DO potentially has a physiological role in ammonia excretion under SW conditions.

Enabling Mitochondrial Uptake of Lipophilic Dications Using Methylated Triphenylphosphonium Moieties.

Triphenylphosphonium (TPP+) species comprising multiple charges, i.e., bis-TPP+, are predicted to be superior mitochondrial-targeting vectors and are expected to have mitochondrial accumulations 1000-fold greater than TPP+, the current "gold standard". However, bis-TPP+ vectors linked by short hydrocarbon chains ( n < 5) are unable to be taken up by the mitochondria, thus hindering their development as mitochondrial delivery vectors. Through the incorporation of methylated TPP+ moieties (T*PP+), we successfully enabled the accumulation of bis-TPP+ with a short linker chain in isolated mitochondria, as measured by high performance liquid chromatography. These experimental results are further supported by molecular dynamics and ab initio calculations, revealing the strong correlations between mitochondria uptake and molecular volume, surface area, and chemical hardness. Most notably, the molecular volume has been shown to be a strong predictor of accumulation for both mono- and bis-TPP+ salts. Our study underscores the potential of T*PP+ moieties as alternative mitochondrial vectors to overcome low permeation into the mitochondria.

Outcome and Management of Refractory Respiratory Failure With Timely Extracorporeal Membrane Oxygenation: Single-Center Experience With Legionella Pneumonia.

OBJECTIVE:: To analyze the management and outcome of patients with refractory respiratory failure complicating severe Legionella pneumonia rescued with extracorporeal membrane oxygenation (ECMO) in our Center. DESIGN AND SETTING:: Observational study of patients with refractory respiratory failure treated with ECMO in Hospital S.João (Porto, Portugal), between November 2009 and September 2016. PARTICIPANTS:: A total of 112 patients rescued with ECMO, of which 14 had Legionella pneumonia. RESULTS:: Patients with Legionella pneumonia were slightly older than patients with acute respiratory failure of other etiologies (51 [48-56] vs 45 [35-54]), but with no significant differences in acute respiratory failure severity between groups: Pao2/Fio2 ratio 67 (60-75) versus 69 (55-85) and Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score 4 (1-5) versus 2 (-1-4), respectively. Legionella pneumonia was associated with earlier ECMO initiation (days of invasive mechanical ventilation [IMV] before ECMO: 2.0 [1.0-4.0] vs 5.0 [2.0-9.5]). After IMV adjustment to "lung rest" settings, this group presented higher respiratory system (RS) static compliance (28.7 [18.8-37.4] vs 16.0 [10.0-20.8] mL/cmH2O) but required higher ECMO support (blood flow 5.0 [4.3-5.4] vs 4.2 [3.6-4.8]). Patients with Legionella pneumonia had shorter IMV (16 [14-23] vs 27 [20-42] days) and lower incidence of intensive care unit nosocomial infections (35.7% vs 64.3%), with a trend to higher hospital survival (85.7% vs 62.2%; P = .13). CONCLUSION:: In Legionella pneumonia complicated by refractory respiratory failure, ECMO support allowed patient stabilization under lung protective ventilation and high survival rates. Timely ECMO referral should be considered for Legionella pneumonia failing conventional treatment.

Is arbuscular mycorrhizal fungal species community affected by cotton growth management systems in the Brazilian Cerrado?

Conventional cotton production in western Bahia, Brazil, involves intensive use of agricultural inputs and mechanization, which may affect arbuscular mycorrhizal fungi (AMF). This work aimed at studying the impact of conventional and organic cotton production in the AMF of western Bahia. Soil samples were obtained from conventional white cotton and colored cotton organic production systems as well as from native Cerrado areas, close to the white cotton fields, and from the subcaducifolia vegetation, close to the organic colored cotton farms. The most frequent species in the conventional farming areas belonged to the genera Acaulospora (10 spp.); Glomus (8 spp.); Dentiscutata (3 spp.); Ambispora, Pacispora and Scutellospora (2 spp. each), as well as Claroideoglomus etunicatum, Diversispora sp., Entrophospora infrequens, Gigaspora sp., Orbispora pernambucana, Paradentiscutata maritima, and Paraglomus occultum. Eighteen species were found in the organic farming areas, with the predominance of Glomus (5 spp.) and Acaulospora (5 spp.), and with Claroideoglomus, Dentiscutata, Gigaspora, Corymbiglomus, Orbispora, Paraglomus, Scutellospora, and Simiglomus (1 spp. each). Paraglomus bolivianum was first reported in Cerrado. In the native vegetation, nine species were found, with the predominance of Glomus and Acaulospora. The highest number of AMF species was found in the organic farming areas, which deserves further investigation.

Understanding Conformational Dynamics of Complex Lipid Mixtures Relevant to Biology.

This is a perspective article entitled "Frontiers in computational biophysics: understanding conformational dynamics of complex lipid mixtures relevant to biology" which is following a CECAM meeting with the same name.

Properties that rank protein:protein docking poses with high accuracy.

The development of docking algorithms to predict near-native structures of protein:protein complexes from the structure of the isolated monomers is of paramount importance for molecular biology and drug discovery. In this study, we assessed the capacity of the interfacial area of protein:protein complexes and of Molecular Mechanics-Poisson Boltzmann Surface Area (MM-PBSA)-derived properties, to rank docking poses. We used a set of 48 protein:protein complexes, and a total of 67 docking experiments distributed among bound:bound, bound:unbound, and unbound:unbound test cases. The MM-PBSA binding free energy of protein monomers has been shown to be very convenient to predict high-quality structures with a high success rate. In fact, considering solely the top-ranked pose of more than 200 docking solutions of each of 39 protein:protein complexes, the success rate was 77% in the prediction of high-quality poses, or 90% if considering high- or medium-quality poses. If considering high- or medium-quality poses as the top-one prediction, a success rate of 87% was obtained for a scoring scheme based on computational alanine scanning mutagenesis data. Such ranking accuracy highlights the ability of these properties to predict near-native poses in protein:protein docking.

Is there a C-reactive protein value beyond which one should consider infection as the cause of acute heart failure?

BACKGROUND: Heart Failure (HF) is a low grade inflammatory condition. High sensitivity C-reactive protein (hsCRP) is an established marker of inflammation. A cut-off value of hsCRP beyond which an infection should be sought has never been studied in HF. We aimed to determine the best hsCRP cut-off for infection prediction in acute HF. METHODS: We analyzed patients included in an acute HF registry - EDIFICA (Estratificação de Doentes com InsuFIciência Cardíaca Aguda). Admission hsCRP measurement was available as part of the registry's protocol. Patients with acute coronary syndrome as the cause of acute HF were excluded from the registry. Infection was considered according to the diagnosis registered in the discharge record. A receiver-operating characteristic (ROC) curve was used to determine the best hsCRP cut-off for infection prediction. RESULTS: We studied 615 patients. Mean age was 76 years, 45.2% were male, 60.3% had systolic dysfunction. Median admission hsCRP was 20.3 (9.5-55.5)mg/L; in 41.6% the cause of decompensation was an infection. The area under the ROC curve for admission hsCRP in the prediction of infection was 0.79 (0.76-0.83); the best hsCRP cut-off was 25 mg/L with a sensitivity of 72.7%, specificity 77.2%, positive predictive value 69.4% and negative predictive value 79.9%. Age and elevated hsCRP independently associated with an infection as the precipitant of acute HF. CONCLUSIONS: We suggest 25 mg/L as a cut-off beyond which an infection should be sought underlying acute HF. Almost 80% of the patients with hsCRP< 25 mg/L are not infected and 69.4% of those with higher hsCRP have a concomitant infection.