Time to Clinical Stability in Patients with Ventilator-Associated Pneumonia due to Methicillin-Resistant Staphylococcus aureus Treated with Linezolid versus Vancomycin: Results from the IMPACT-HAP Study

Background: Time to clinical stability is a well-defined early clinical outcome in hospitalized patients with community-acquired pneumonia, but it has not been evaluated in patients with ventilator-associated pneumonia (VAP). The objective of this study was to compare time to clinical stability in patients with MRSA VAP treated with linezolid versus vancomycin. Methods: This was a secondary analysis of the IMPACT-HAP study database. VAP was defined according to CDC criteria. MRSA VAP was considered when MRSA was isolated from a tracheal aspirate or bronchoalveolar lavage. A patient was considered to reach clinical stability the day that the following four criteria were met: 1) Afebrile for 24 hours, 2) Decrease in WBC \u3e10% or WBC within normal range, 3) Improving of PaO2/FiO2 ratio of \u3e 20%, or PaO2/FiO2 ratio \u3e 250, or extubation, or FiO2 ≤ 30% if extubated, and 4) Systolic blood pressure \u3e90 mmHg. Time to clinical stability for linezolid and vancomycin were compared using the Chi-Squared and Student’s t-tests. Results: A total of 89 patients treated with linezolid and 75 patients treated with vancomycin met study criteria. From the population of linezolid treated patients, 79% reached clinical stability, compared to 75% of the population of vancomycin treated patients (P=0.463). Median time to clinical stability was 6 days (IQR 8) for patients treated with linezolid, versus 7 days (IQR 12) for patients treated with vancomycin (P=0.490). Conclusions: This study failed to demonstrate a statistically significant difference in time to clinical stability in patients with MRSA VAP treated with linezolid or vancomycin. The number of days for patients to reach clinical stability can be used as an early clinical outcome in patients with VAP

Distribution of Legionella Species and Serogroups Isolated by Culture in Patients with Sporadic Community-Acquired Legionellosis: An International Collaborative Survey

This international collaborative survey identified culture-confirmed legionellosis in 508 patients with sporadic community-acquired legionellosis. Legionella pneumophila constituted 91.5% of the isolates. Serogroup 1 was the predominant serogroup (84.2%), and serogroups 2-13 (7.4%) accounted for the remaining serogroups. The Legionella species most commonly isolated were L. longbeachae (3.9%) and L. bozemanii (2.4%), followed by L. micdadei, L. dumoffii, L. feeleii, L. wadsworthii and L. anisa (2.2% combined). L. longbeachae constituted 30.4% of the community-acquired Legionella isolates in Australia and New Zealan

Factors Associated With Antimicrobial Resistance and Mortality in Pneumococcal Bacteremia

We conducted a multicenter, retrospective cohort study of patients with Streptococcus pneumoniae bacteremia to determine factors associated with antibiotic resistance and mortality. Risk factors were identified using multivariate logistic regression. 1,574 patients at 34 sites were enrolled. Compared to isolates from patients not receiving an antibiotic before the index blood culture, patients receiving an antibiotic were less likely to harbor an antibiotic susceptible organism. Susceptibility to penicillin decreased from 78% (95% confidence interval [CI], 75−80) to 49% (95%CI, 39−59); to cefotaxime/ceftriaxone, from 92% (95%CI, 90−93) to 82% (95%CI, 72−89); and to macrolide, from 84% (95%CI, 82−87) to 55% (95%CI, 41−68). Factors associated with macrolide non-susceptibility include: >24 hours of antibiotic therapy at time of the index culture (odds ratio [OR] 4.0), residing in southern U.S. (OR 1.7), and having an antibiotic allergy (OR 1.7). Harboring an antibiotic non-susceptible strain (OR 1.4) and male sex (OR 1.4) were associated with increased risk of mortality, whereas Black race (OR 0.6) and evidence of focal infection (OR 0.6) were associated with decreased risk

Assessment of Time to Clinical Response, a Proxy for Discharge Readiness, among Hospitalized Patients with Community-Acquired Pneumonia Who Received either Ceftaroline Fosamil or Ceftriaxone in Two Phase III FOCUS Trials

ABSTRACT The primary driver of health care costs for patients with community-acquired pneumonia (CAP) is the hospital length of stay (LOS). Unfortunately, hospital LOS comparisons are difficult to make from phase III CAP trials because of their structured designs and prespecified treatment durations. However, an opportunity still exists to draw inferences about potential LOS differences between treatments through the use of surrogates for hospital discharge. The intent of this study was to quantify the time to a clinical response, a proxy for the time to discharge readiness, among hospitalized CAP patients who received either ceftaroline or ceftriaxone in two phase III CAP FOCUS clinical trials. On the basis of the Infectious Diseases Society of America and American Thoracic Society CAP management guidelines and recent FDA guidance documents for community-acquired bacterial pneumonia, a post hoc adjudication algorithm was constructed a priori to compare the time to a clinical response, a proxy for the time to discharge readiness, between patients who received ceftaroline or ceftriaxone. Overall, 1,116 patients (ceftaroline, n = 562; ceftriaxone, n = 554) from the pooled FOCUS trials met the selection criteria for this analysis. Kaplan-Meier analyses showed that ceftaroline was associated with a shorter time, measured in days, to meeting the clinical response criteria ( P = 0.03). Of the patients on ceftaroline, 61.0, 76.1, and 83.6% achieved a clinical response by days 3, 4, and 5, compared to 54.3, 69.8, and 79.3% of the ceftriaxone-treated patients. In the Cox regression, ceftaroline was associated with a shorter time to a clinical response (HR, 1.16, P = 0.02). The methodology employed here provides a framework to draw comparative effectiveness inferences from phase III CAP efficacy trials. (The FOCUS trials whose data were analyzed in this study have been registered at ClinicalTrials.gov under registration no. NCT00621504 and NCT00509106.

Sepsis in Patients with Ventilator Associated Pneumonia due to Methicillin- Resistant Staphylococcus aureus: Incidence and Impact on Clinical outcomes

Background: Sepsis is a clinical syndrome associated with organ dysfunction due to a dysregulated host response to infection. Methicillin-resistant Staphylococcus aureus (MRSA) Ventilator-associated pneumonia (VAP) is a serious infection frequently associated with sepsis. The objectives of this study were to define the incidence of sepsis and clinical failure in patients with MRSA VAP. Methods: This was a secondary analysis of the Improving Medicine through Pathway Assessment of Critical Therapy in Hospital-Acquired Pneumonia (IMPACT-HAP) study database. VAP was defined according to CDC criteria. MRSA VAP was considered when MRSA was isolated from a tracheal aspirate or bronchoalveolar lavage. We used the 3rd International Consensus Definitions for sepsis. The presence of clinical failure was evaluated at the 14-day follow-up and defined as: 1) progression of baseline signs and symptoms of pneumonia, or 2) death. The Chi- Square Trend Test was utilized to determine the association between the level of organ dysfunction and clinical failure. Results: MRSA VAP was diagnosed in 205 patients with 138 (67%) presenting with sepsis. Clinical failure occurred in 14% (8/57) of patients without sepsis. Clinical failure occurred in 18% (13/73) of patients with sepsis and 1 organ dysfunction, in 28% (12/43) of patients with sepsis and 2 organ dysfunction, in 28% (5/18) of patients with sepsis and 3 organ dysfunction, and in 100% (4/4) of patients with sepsis and 4 organ dysfunction (p= 0.01). Conclusions: Sepsis is a frequent complication of MRSA VAP and the number of organ dysfunction correlates with clinical failure in these patients. Effective prevention and treatment of sepsis and associated organ dysfunction is essential to avoid cumulative burden of disease in MRSA VAP

Pneumococcal epidemiology among us adults hospitalized for community-acquired pneumonia

BACKGROUND: Few studies have measured the burden of adult pneumococcal disease after the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the US infant vaccination schedule. Further, most data regarding pneumococcal serotypes are derived from invasive pneumococcal disease (IPD), which represents only a fraction of all adult pneumococcal disease burden. Understanding which pneumococcal serotypes cause pneumonia in adults is critical for informing current immunization policy. The objective of this study was to measure the proportion of radiographically-confirmed (CXR+) community-acquired pneumonia (CAP) caused by PCV13 serotypes in hospitalized US adults. METHODS: This observational, prospective surveillance study recruited hospitalized adults aged \u3e /=18years from 21 acute care hospitals across 10 geographically-dispersed cities in the United States between October 2013 and September 2016. Clinical and demographic data were collected during hospitalization. Vital status was ascertained 30days after enrollment. Pneumococcal serotypes were detected via culture from the respiratory tract and normally-sterile sites (including blood and pleural fluid). Additionally, a novel, Luminex-based serotype-specific urinary antigen detection (UAD) assay was used to detect serotypes included in PCV13. RESULTS: Of 15,572 enrolled participants, 12,055 eligible patients with CXR+CAP were included in the final analysis population. Mean age was 64.1years and 52.7% were aged \u3e /=65years. Common comorbidities included chronic obstructive pulmonary disease (43.0%) and diabetes mellitus (28.6%). PCV13 serotypes were detected in 552/12,055 (4.6%) of all patients and 265/6347 (4.2%) of those aged \u3e /=65years. Among patients aged 18-64years PCV13 serotypes were detected in 3.8-5.3% of patients depending on their risk status. CONCLUSIONS: After implementation of a pneumococcal conjugate vaccination program in US children, and despite the herd protection observed in US adults, a persistent burden of PCV13-type CAP remains in this population

Effects of Alcohol on the Acquisition and Expression of Fear Potentiated Startle in Mouse Lines Selectively Bred for High and Low Alcohol Preference

Rationale: Anxiety disorders and alcohol-use disorders frequently co-occur in humans perhaps because alcohol relieves anxiety. Studies in humans and rats indicate that alcohol may have greater anxiolytic effects in organisms with increased genetic propensity for high alcohol consumption. Objectives and Methods: The purpose of this study was to investigate the effects of moderate doses of alcohol (0.5, 1.0, 1.5 g/kg) on the acquisition and expression of anxiety-related behavior using a fear-potentiated startle (FPS) procedure. Experiments were conducted in two replicate pairs of mouse lines selectively bred for high- (HAP1 and HAP2) and low- (LAP1 and LAP2) alcohol preference; these lines have previously shown a genetic correlation between alcohol preference and FPS (HAP\u3eLAP; Barrenha and Chester 2007). In a control experiment, the effect of diazepam (4.0 mg/kg) on the expression of FPS was tested in HAP2 and LAP2 mice. Results: The 1.5 g/kg alcohol dose moderately decreased the expression of FPS in both HAP lines but not LAP lines. Alcohol had no effect on the acquisition of FPS in any line. Diazepam reduced FPS to a similar extent in both HAP2 and LAP2 mice. Conclusions: HAP mice may be more sensitive to the anxiolytic effects of alcohol than LAP mice when alcohol is given prior to the expression of FPS. These data collected in two pairs of HAP/LAP mouse lines suggest that the anxiolytic response to alcohol in HAP mice may be genetically correlated with their propensity toward high alcohol preference and robust FPS

Pharmacological Alterations of Anxious Behaviour in Mice Depending on Both Strain and the Behavioural Situation

A previous study comparing non-emotive mice from the strain C57BL/6/ByJ with ABP/Le mice showed ABP/Le to be more anxious in an open-field situation. In the present study, several compounds affecting anxiety were assayed on ABP/Le and C57BL/6/ByJ mice using three behavioural models of anxiety: the elevated plus-maze, the light-dark discrimination test and the free exploratory paradigm. The compounds used were the full benzodiazepine receptor agonist, chlordiazepoxide, and the antagonist, flumazenil, the GABAA antagonist, bicuculline, the full 5-HT1A agonist 8-OH-DPAT, and the mixed 5-HT1A/5-HT1B agonist, RU 24969. Results showed the effect of the compounds to be dependent on both the strain and the behavioural task. Several compounds found to be anxiolytic in ABP/Le mice had an anxiogenic effect on C57BL/6/ByJ mice. More behavioural changes were observed for ABP/Le in the elevated plus-maze, but the clearest findings for C57BL/6/ByJ mice were observed in the light-dark discrimination apparatus. These data demonstrate that anxious behaviour is a complex phenomenon which cannot be described by a single behavioural task nor by the action of a single compound

Synaptic E3 Ligase SCRAPPER in Contextual Fear Conditioning: Extensive Behavioral Phenotyping of Scrapper Heterozygote and Overexpressing Mutant Mice

SCRAPPER, an F-box protein coded by FBXL20, is a subunit of SCF type E3 ubiquitin ligase. SCRAPPER localizes synapses and directly binds to Rab3-interacting molecule 1 (RIM1), an essential factor for synaptic vesicle release, thus it regulates neural transmission via RIM1 degradation. A defect in SCRAPPER leads to neurotransmission abnormalities, which could subsequently result in neurodegenerative phenotypes. Because it is likely that the alteration of neural transmission in Scrapper mutant mice affect their systemic condition, we have analyzed the behavioral phenotypes of mice with decreased or increased the amount of SCRAPPER. We carried out a series of behavioral test batteries for Scrapper mutant mice. Scrapper transgenic mice overexpressing SCRAPPER in the hippocampus did not show any significant difference in every test argued in this manuscript by comparison with wild-type mice. On the other hand, heterozygotes of Scrapper knockout [SCR (+/−)] mice showed significant difference in the contextual but not cued fear conditioning test. In addition, SCR (+/−) mice altered in some tests reflecting anxiety, which implies the loss of functions of SCRAPPER in the hippocampus. The behavioral phenotypes of Scrapper mutant mice suggest that molecular degradation conferred by SCRAPPER play important roles in hippocampal-dependent fear memory formation

FOCUS 1: a randomized, double-blinded, multicentre, Phase III trial of the efficacy and safety of ceftaroline fosamil versus ceftriaxone in community-acquired pneumonia

Objectives: Ceftaroline, the active form of the prodrug ceftaroline fosamil, is a novel cephalosporin with bactericidal activity against important pathogens associated with community-acquired pneumonia (CAP), including Streptococcus pneumoniae and common Gram-negative pathogens. FOCUS 1 is a randomized, double-blinded, Phase III study that was conducted to evaluate the efficacy and safety of ceftaroline fosamil in treating patients with CAP. The primary objective was to determine non-inferiority [lower limit of 95% confidence interval (CI) ≥ 210%] in clinical cure rates achieved with ceftaroline fosamil compared with those achieved with ceftriaxone in the clinically evaluable (CE) and modified intent-to-treat efficacy (MITTE) populations. Methods: Patients hospitalized in a non-intensive care unit setting with CAP of Pneumonia Outcomes Research Team (PORT) risk class III or IV requiring intravenous (iv) therapy were randomized (1:1) to receive 600 mg of ceftaroline fosamil iv every 12 h or 1 g of ceftriaxone iv every 24 h. Patients also received two 500 mg doses of oral clarithromycin every 12 h administered on day 1. Clinical cure, microbiological response, adverse events (AEs) and laboratory tests were assessed. FOCUS 1 registration number NCT00621504 (http://clinicaltrials.gov/ ct2/show/NCT00621504). Results: Of 613 enrolled patients, 298 received ceftaroline fosamil and 308 received ceftriaxone. Baseline characteristics between treatment groups were comparable. Clinical cure rates were as follows: CE population, 86.6% (194/224) for ceftaroline fosamil and 78.2% (183/234) for ceftriaxone [difference (95% CI), 8.4% (1.4, 15.4)]; and MITTE population, 83.8% (244/291) for ceftaroline fosamil and 77.7% (233/300) for ceftriaxone [difference (95% CI), 6.2% (20.2, 12.6)]. Clinical cure rates for CAP caused by S. pneumoniae in the microbiological MITTE population were 88.9% (24/27) and 66.7% (20/30) for ceftaroline fosamil and ceftriaxone, respectively. Both agents were well tolerated, with similar rates of AEs, serious AEs, deaths and discontinuations because of an AE. The most common AEs for ceftaroline fosamil-treated patients were diarrhoea, headache, insomnia and nausea, and the most common AEs for ceftriaxone-treated patients were hypokalaemia, hypertension, nausea and diarrhoea. Conclusions: Ceftaroline fosamil demonstrated high clinical cure and microbiological response rates in hospitalized patients with CAP of PORTrisk class III or IV. Ceftaroline fosamil was well tolerated, with a safety profile similar to that of ceftriaxone and consistent with the cephalosporin class. In this study, ceftaroline fosamil was an effective and well-tolerated treatment option for CAP