Microbial Diversity of Adult Aedes aegypti and Water Collected from Different Mosquito Aquatic Habitats in Puerto Rico

Mosquitoes, the major vectors of viruses like dengue, are naturally host to diverse microorganisms, which play an important role in their development, fecundity, immunity, and vector competence. The composition of their microbiota is strongly influenced by the environment, particularly their aquatic larval habitat. In this study, we used 2×300 bp 16s Illumina sequencing to compare the microbial profiles of emerging adult Aedes aegypti mosquitoes and the water collected from common types of aquatic habitat containers in Puerto Rico, which has endemic dengue transmission. We sequenced 141 mosquito and 46 water samples collected from plastic containers, septic tanks, discarded tires, underground trash cans, tree holes, or water meters. We identified 9 bacterial genera that were highly prevalent in the mosquito microbiome, and 77 for the microbiome of the aquatic habitat. The most abundant mosquito-associated bacterial OTUs were from the families Burkholderiaceae, Pseudomonadaceae, Comamonadaceae, and Xanthomonadaceae. Microbial profiles varied greatly between mosquitoes, and there were few major differences explained by container type; however, the microbiome of mosquitoes from plastic containers was more diverse and contained more unique taxa than the other groups. Container water was significantly more diverse than mosquitoes, and our data suggest that mosquitoes filter out many bacteria, with Alphaproteobacteria in particular being far more abundant in water. These findings provide novel insight into the microbiome of mosquitoes in the region and provide a platform to improve our understanding of the fundamental mosquito-microbe interactions.

Intrapulmonary pharmacokinetics of high doses of tigecycline in patients with ventilator-associated pneumonia

Tigecycline is commonly used for infections by multidrug-resistant bacteria. However, it is not approved for ventilator-associated pneumonia (VAP) as increased mortality has been reported in VAP patients treated with conventional doses. The purpose of this study was to prospectively evaluate the intrapulmonary pharmacokinetics of off-label high-dose tigecycline in patients with VAP. Nine mechanically ventilated patients received tigecycline intravenously (loading dose 200 mg followed by 100 mg every 12 h). After ≥5 doses, two bronchoscopies were performed in each patient on consecutive days and eight blood samples were collected. Tigecycline concentrations in plasma and bronchoalveolar lavage fluid were determined by liquid chromatography. The urea dilution method was used to calculate epithelial lining fluid (ELF) concentrations. A two-compartmental pharmacokinetic (PK) model with linear elimination was used to estimate PK parameters. Mean patient age was 69 ± 11.86 years and mean APACHE II score was 21. The estimated population mean PK parameters (relative standard error) were: clearance, 11.64 L/h (54%); volume of distribution in central compartment, 79.01 L (37%); volume of distribution in peripheral compartment, 92.95 L (17%); intercompartmental clearance, 62.81 L/h (34%); and ELF penetration ratio, 2.41 (40%). C_max, C_min, plasma AUC_0-12, plasma fAUC_0-12 and ELF AUC_0-12 were 1.99 ± 1.82 μg/mL, 0.81 ± 1.27 μg/mL, 12.89 ± 17.25 μg•h/mL, 3.24 ± 3.09 μg•h/mL and 7.13 ± 2.61 μg•h/mL, respectively. The increased plasma and ELF AUC_0-12 achieved with a 200 mg daily tigecycline dose, combined with high ELF penetration, support the effectiveness of off-label high-dose tigecycline in VAP.

Impaired cognitive performance on MoCA testing at discharge in elderly patients following day endoscopy and its relationship to preoperative mild cognitive impairment

In patients admitted to hospital, preoperative mild cognitive impairment predicts postoperative complications. The effect of mild cognitive impairment on discharge readiness among the day stay surgery population is unknown. Our aims were to determine the incidence of impaired cognitive performance at discharge after day stay endoscopy and whether pre-existing mild cognitive impairment was associated with its development. A single-centre cohort study of elective day stay endoscopy patients was undertaken. Over a three-month period, data were collected from 69 patients aged 65 years and over. Patients were cognitively assessed on admission and discharge using the Montreal cognitive assessment tool and the three-minute diagnostic confusion assessment method. At baseline, patients who scored 1.5 or more standard deviations below age-adjusted levels on the Montreal cognitive assessment tool in conjunction with a subjective memory complaint were classified as having mild cognitive impairment. At discharge, patients were classified as having impaired cognitive performance if there was a reduction in the Montreal cognitive assessment tool score by at least two points. We also assessed delirium and subsyndromal delirium at discharge using the three-minute diagnostic confusion assessment method. We identified mild cognitive impairment in 23 patients (33.3%) on admission, and impaired performance on the Montreal cognitive assessment tool test at discharge in 35 (50.7%) patients. There was no association between mild cognitive impairment on admission and impaired cognitive performance at discharge (50.0% versus 51.1%, P = 0.94). This study demonstrates that evidence of impaired cognitive performance on the Montreal cognitive assessment tool testing is present after day stay endoscopy in over 50% of elderly patients, but this is not associated with preoperative cognitive status.

Prospects and Pitfalls: Next-Generation Tools to Control Mosquito-Transmitted Disease

Mosquito-transmitted diseases, including malaria and dengue, are a major threat to human health around the globe, affecting millions each year. A diverse array of next-generation tools has been designed to eliminate mosquito populations or to replace them with mosquitoes that are less capable of transmitting key pathogens. Many of these new approaches have been built on recent advances in CRISPR/Cas9-based genome editing. These initiatives have driven the development of pathogen-resistant lines, new genetics-based sexing methods, and new methods of driving desirable genetic traits into mosquito populations. Many other emerging tools involve microorganisms, including two strategies involving Wolbachia that are achieving great success in the field. At the same time, other mosquito-associated bacteria, fungi, and even viruses represent untapped sources of new mosquitocidal or antipathogen compounds. Although there are still hurdles to be overcome, the prospect that such approaches will reduce the impact of these diseases is highly encouraging.

Demographic and clinical features of critically ill patients with COVID-19 in Greece: The burden of diabetes and obesity

AIMS

The aim of the study was to investigate the association between type-2 diabetes mellitus, other underlying diseases and obesity with the outcomes of critically ill Covid-19 patients in Greece.

METHODS

In this retrospective observational multi-centre study, data and outcomes of 90 RNA 2109-nCoV confirmed critically ill patients from 8 hospitals throughout Greece, were analysed. All reported information stand through April 13th 2020.

RESULTS

The median age of the patients was 65.5 (IQR 56-73), majority were male (80%) and obesity was present in 34.4% of patients most prevalent to younger than 55 years. Hypertension was the prevailing comorbidity (50%), followed by cardiovascular diseases (21.1%) and type-2 diabetes (18.9%). At admission, common symptoms duration had a median of 8 (IQR 5-11) days. A 13.3% of the patients were discharged, 53.4% were still in the ICUs and 28.9% deceased who were hospitalised for fewer days than the survivors [6 (IQR 3-9) vs. 9 (IQR 7-14.5) respectively]. Aging was not a risk factor but diabetes deteriorates the outcomes. Obesity poses a suggestive burden as it was more notable in deceased versus survivors.

CONCLUSIONS

Type 2 diabetes and obesity may have contributed to disease severity and mortality in COVID-19 critically ill patients in Greece.

Seroprevalence of Aspergillus IgG and disease prevalence of chronic pulmonary aspergillosis in a country with intermediate burden of tuberculosis: a prospective observational study

OBJECTIVES

Chronic pulmonary aspergillosis (CPA) is an emerging global disease with tuberculosis (TB) being the most important risk factor. Epidemiologic data on the seroprevalence of Aspergillus IgG and prevalence of CPA in different areas, especially in country with intermediate burden of TB, are lacking.

METHODS

We prospectively recruited healthy volunteers, TB close contacts, active TB patients and participants with old pulmonary TB in Taiwan during 2012-2019. We measured serum Aspergillus fumigatus and niger-specific IgG levels and assessed if the participants were having CPA.

RESULTS

A total of 1242 participants (including 200 healthy volunteers, 326 TB close contacts, 524 active TB patients and 192 old TB cases) were recruited. Using 27 mgA/L (milligrams of antigen-specific antibodies per liter) as cut-off level, the seropositive rate of A. fumigatus-specific IgG was 33.0% (66/200), 37.7% (123/326), 26.5% (139/524) and 43.2% (83/192) among the four groups, respectively. In multivariate logistic regression, pulmonary cavitation (OR 1.73; 95% CI 1.07-2.80), female sex (OR 1.49; 95% CI 1.14-1.95), old TB (OR 1.59; 1.05-2.42) were independent risk factors for Aspergillus IgG positivity. One (0.2%) active TB patient and four (2.1%) old TB patients developed CPA. Correlation between A. fumigatus and A. niger-specific IgG was high (Spearman correlation coefficient: 0.942).

DISCUSSION

Geographic variation in Aspergillus IgG seroprevalence and CPA prevalence exists. A universal cut-off value for Aspergillus IgG may not exist. In areas and populations in which background Aspergillus IgG level is unknown, Aspergillus IgG may be better used as a test of exclusion for CPA using prespecified cut-off level.

Elderly versus nonelderly patients with invasive aspergillosis in the ICU: a comparison and risk factor analysis for mortality from the AspICU cohort

Data regarding the epidemiology and diagnosis of invasive aspergillosis in the critically ill population are limited, with data regarding elderly patients (≥75 years old) even scarcer. We aimed to further compare the epidemiology, characteristics and outcome of elderly versus nonelderly critically ill patients with invasive aspergillosis (IA) Prospective, international, multicenter observational study (AspICU) including adult intensive care unit (ICU) patients, with a culture and/or direct examination and/or histopathological sample positive for Aspergillus spp. at any site. We compared clinical characteristics and outcome of IA in ICU patients using two different diagnostic algorithms. Elderly and nonelderly ICU patients with IA differed in a number of characteristics, including comorbidities, clinical features of the disease, mycology testing, and radiological findings. No difference regarding mortality was found. According to the clinical algorithm, elderly patients were more likely to be diagnosed with putative IA. Elderly patients had less diagnostic radiological findings and when these findings were present they were detected late in the disease course. The comparison between elderly survivors and nonsurvivors demonstrated differences in clinical characteristics of the disease, affected sites and supportive therapy needed. All patients who were diagnosed with proven IA died. Increased vigilance combined with active search for mycological laboratory evidence and radiological confirmation are necessary for the timely diagnosis of IA in the elderly patient subset. Although elderly state per se is not a particular risk factor for mortality, a high SOFA score and the decision not to administer antifungal therapy may have an impact on survival of elderly patients.

MicroRNAs 143 and 150 in whole blood enable detection of T-cell immunoparalysis in sepsis

Background

Currently, no suitable clinical marker for detection of septic immunosuppression is available. We aimed at identifying microRNAs that could serve as biomarkers of T-cell mediated immunoparalysis in sepsis.

Methods

RNA was isolated from purified T-cells or from whole blood cells obtained from septic patients and healthy volunteers. Differentially regulated miRNAs were identified by miRNA Microarray (n = 7). Validation was performed via qPCR (n = 31).

Results

T-cells of septic patients revealed characteristics of immunosuppression: Pro-inflammatory miR-150 and miR-342 were downregulated, whereas anti-inflammatory miR-15a, miR-16, miR-93, miR-143, miR-223 and miR-424 were upregulated. Assessment of T-cell effector status showed significantly reduced mRNA-levels of IL2, IL7R and ICOS, and increased levels of IL4, IL10 and TGF-β. The individual extent of immunosuppression differed markedly. MicroRNA-143, − 150 and − 223 independently indicated T-cell immunoparalysis and significantly correlated with patient’s IL7R-/ICOS-expression and SOFA-scores. In whole blood, composed of innate and adaptive immune cells, both traits of immunosuppression and hyperinflammation were detected. Importantly, miR-143 and miR-150 – both predominantly expressed in T-cells – retained strong power of discrimination also in whole blood samples.

Conclusions

These findings suggest miR-143 and miR-150 as promising markers for detection of T-cell immunosuppression in whole blood and may help to develop new approaches for miRNA-based diagnostic in sepsis.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0056-z) contains supplementary material, which is available to authorized users.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Management of KPC-producing Klebsiella pneumoniae infections

BACKGROUND

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas.

AIMS

To provide practical suggestion for physicians dealing with the management of KPC-KP infections in critically ill patients, based on expert opinions.

SOURCES

PubMed search for relevant publications related to the management of KPC-KP infections.

CONTENTS

A panel of experts developed a list of 12 questions to be addressed. In view of the current lack of high-level evidence, they were asked to provide answers on the bases of their knowledge and experience in the field. The panel identified several key aspects to be addressed when dealing with KPC-KP in critically ill patients (preventing colonization in the patient, preventing infection in the colonized patient and colonization of his or her contacts, reducing mortality in the infected patient by rapidly diagnosing the causative agent and promptly adopting the best therapeutic strategy) and provided related suggestions that were based on the available observational literature and the experience of panel members.

IMPLICATIONS

Diagnostic technologies could speed up the diagnosis of KPC-KP infections. Combination treatment should be preferred to monotherapy in cases of severe infections. For non-critically ill patients without severe infections, results from randomized clinical trials are needed for ultimately weighing benefits and costs of using combinations rather than monotherapy. Multifaceted infection control interventions are needed to decrease the rates of colonization and cross-transmission of KPC-KP.

Validation of the new Sepsis-3 definitions: proposal for improvement in early risk identification

OBJECTIVES

Sepsis-3 definitions generated controversies regarding their general applicability. The Sepsis-3 Task Force outlined the need for validation with emphasis on the quick Sequential Organ Failure Assessment (qSOFA) score. This was done in a prospective cohort from a different healthcare setting.

METHODS

Patients with infections and at least two signs of systemic inflammatory response syndrome (SIRS) were analysed. Sepsis was defined as total SOFA ≥2 outside the intensive care unit (ICU) or as an increase of ICU admission SOFA ≥2. The primary endpoints were the sensitivity of qSOFA outside the ICU and sepsis definition both outside and within the ICU to predict mortality.

RESULTS

In all, 3346 infections outside the ICU and 1058 infections in the ICU were analysed. Outside the ICU, respective mortality with ≥2 SIRS and qSOFA ≥2 was 25.3% and 41.2% (p <0.0001); the sensitivities of qSOFA and of sepsis definition to predict death were 60.8% and 87.2%, respectively. This was 95.9% for sepsis definition in the ICU. The sensitivity of qSOFA and of ≥3 SIRS criteria for organ dysfunction outside the ICU was 48.7% and 72.5%, respectively (p <0.0001). Misclassification outside the ICU with the 1991 and Sepsis-3 definitions into stages of lower severity was 21.4% and 3.7%, respectively (p <0.0001) and 14.9% and 3.7%, respectively, in the ICU (p <0.0001). Adding arterial pH ≤7.30 to qSOFA increased sensitivity for prediction of death to 67.5% (p 0.004).

CONCLUSIONS

Our analysis positively validated the use of SOFA score to predict unfavourable outcome and to limit misclassification into lower severity. However, qSOFA score had inadequate sensitivity for early risk assessment.

Predictors of choice of initial antifungal treatment in intraabdominal candidiasis

Intraabdominal candidiasis (IAC) is the second most frequent form of invasive candidiasis, and is associated with high mortality rates. This study aims to identify current practices in initial antifungal treatment (IAT) in a real-world scenario and to define the predictors of the choice of echinocandins or azoles in IAC episodes. Secondary analysis was performed of a multinational retrospective cohort at 13 teaching hospitals in four countries (Italy, Greece, Spain and Brazil), over a 3-year period (2011-2013). IAC was identified in 481 patients, 323 of whom received antifungal therapy (classified as the treatment group). After excluding 13 patients given amphotericin B, the treatment group was further divided into the echinocandin group (209 patients; 64.7%) and the azole group (101 patients; 32.3%). Median APACHE II scores were significantly higher in the echinocandin group (p 0.013), but IAT did not differ significantly with regard to the Candida species involved. Logistic multivariate stepwise regression analysis, adjusted for centre effect, identified septic shock (adjusted OR (aOR) 1.54), APACHE II >15 (aOR 1.16) and presence in surgical ward at diagnosis (aOR 1.16) as the top three independent variables associated with an empirical echinocandin regimen. No differences in 30-day mortality were observed between groups. Echinocandin regimen was the first choice for IAT in patients with IAC. No statistical differences in mortality were observed between regimens, but echinocandins were administered to patients with more severe disease. Some disagreements were identified between current clinical guidelines and prescription of antifungals for IAC at the bedside, so further educational measures are required to optimize therapies.

Therapeutic management of peritonitis: a comprehensive guide for intensivists

PURPOSE

The management of peritonitis in critically ill patients is becoming increasingly complex due to their changing characteristics and the growing prevalence of multidrug-resistant (MDR) bacteria.

METHODS

A multidisciplinary panel summarizes the latest advances in the therapeutic management of these critically ill patients.

RESULTS

Appendicitis, cholecystitis and bowel perforation represent the majority of all community-acquired infections, while most cases of healthcare-associated infections occur following suture leaks and/or bowel perforation. The micro-organisms involved include a spectrum of Gram-positive and Gram-negative bacteria, as well as anaerobes and fungi. Healthcare-associated infections are associated with an increased likelihood of MDR pathogens. The key elements for success are early and optimal source control and adequate surgery and appropriate antibiotic therapy. Drainage, debridement, abdominal cleansing, irrigation, and control of the source of contamination are the major steps to ensure source control. In life-threatening situations, a "damage control" approach is the safest way to gain time and achieve stability. The initial empirical antiinfective therapy should be prescribed rapidly and must target all of the micro-organisms likely to be involved, including MDR bacteria and fungi, on the basis of the suspected risk factors. Dosage adjustment needs to be based on pharmacokinetic parameters. Supportive care includes pain management, optimization of ventilation, haemodynamic and fluid monitoring, improvement of renal function, nutrition and anticoagulation.

CONCLUSIONS

The majority of patients with peritonitis develop complications, including worsening of pre-existing organ dysfunction, surgical complications and healthcare-associated infections. The probability of postoperative complications must be taken into account in the decision-making process prior to surgery.

COPD patients with ventilator-associated pneumonia: implications for management

Data on the occurrence and outcome of patients with chronic obstructive pulmonary disease (COPD) and ventilator-associated pneumonia (VAP) are quite limited. The aim of this study was to determine if COPD intensive care unit (ICU) patients have a higher rate of VAP development, different microbiological aetiology or have worse outcomes than other patients without VAP. A secondary analysis of a large prospective, observational study conducted in 27 European ICUs was carried out. Trauma patients were excluded. Of 2082 intubated patients included in the study, 397 (19.1%) had COPD; 79 (19.9%) patients with COPD and 332 (19.7%) patients without COPD developed VAP. ICU mortality increased by 17% (p < 0.05) when COPD patients developed VAP, remaining an independent predictor of mortality [odds ratio (OR) 2.28; 95% confidence interval (CI) 1.35-3.87]. The development of VAP in COPD patients was associated with a median increase of 12 days in the duration of mechanical ventilation and >13 days in ICU stay (p < 0.05). Pseudomonas aeruginosa was more common in VAP when COPD was present (29.1% vs. 18.7%, p = 0.04) and was the most frequent isolate in COPD patients with early-onset VAP, with a frequency 2.5 times higher than in patients without early-onset VAP (33.3% vs. 13.3%, p = 0.03). COPD patients are not more predisposed to VAP than other ICU patients, but if COPD patients develop VAP, they have a worse outcome. Antibiotic coverage for non-fermenters needs to be included in the empiric therapy of all COPD patients, even in early-onset VAP.

Use of selective digestive tract decontamination in European intensive cares: the ifs and whys

BACKGROUND

Several studies have shown that the use of selective digestive tract decontamination (SDD) reduces mortality. However, fear for increasing multidrug resistance might prevent wide acceptance. A survey was performed among the units registered in the European Registry for Intensive Care (ERIC), in order to investigate the number of ICUs using SDD and the factors that prevented the use of SDD.

METHODS

One invitation to the electronic survey was sent to each ERIC unit. The survey focused on department characteristics (intensive care type, local resistance levels), local treatment modalities (antibiotic stewardship) and doctors' opinions (collaborative issues concerning SDD). All ICU's in countries participating in the European Centre for Disease Prevention and Control resistance surveillance program were analysed.

RESULTS

Seventeen percent of the ICUs registered in the ERIC database used SDD prophylaxis. Most of these ICUs were located in the Netherlands or Germany. ICUs using SDD were four times more likely to use antibiotic stewardship. Also larger ICUs were more likely to use SDD. On the contrary, resistance to antibiotics was not related to the use of SDD. Also the doctor's opinion that SDD is proven in cluster-randomized trials was not a determinant for not using SDD.

CONCLUSION

SDD is used in a minority of the European ICUs registered in the ERIC database. Larger ICUs and ICUs with a prudent antibiotic policy were more likely to use SDD. Neither antibiotic resistance nor the cluster randomized study design were determinants of the non-use of SDD.

Bloodstream infections in ICU with increased resistance: epidemiology and outcomes

BACKGROUND

Aim of this study was to evaluate the epidemiology and outcomes of hospital-acquired bloodstream infections (HA-BSI) in Greek intensive care units (ICU).

METHODS

Secondary analysis of data from 29 ICU collected during the EUROBACT study, a large prospective, observational, multination survey of HA-BSI. First episodes of HA-BSI acquired in the ICU or within 48 hours prior to admission were recorded.

RESULTS

Gram-negative bacteria predominated namely Acinetobacter sp, Klebsiella sp, Pseudomonas sp (73.3% of monomicrobial infections) followed by Gram-positive cocci (18.3%); fungi (7.6%) and anaerobes (0.8%). Overall 73.3% of isolates were multidrug resistant (MDR), 47.1% extensively resistant (XDR) and 1.2% pan-drug resistant (PDR). Carbapenems were the most frequent empirically prescribed antibiotics, while colistin was the most frequently adequate; for both, calculated mean total daily doses were suboptimal. Overall 28-day all-cause mortality was 33.3%. In the multivariate analysis, factors adversely affecting outcome were higher SOFA score at HA-BSI onset (OR 1.19; 95% CI 1.08-1.31, P=0.0006), need for renal supportive therapy (OR 2.75; 95% CI 1.35-5.59, P=0.0053), and for vasopressors/inotropes (OR 2.68; CI 1.18-6.12, P=0.02); adequate empirical treatment had a protective effect (OR 0.48; CI 0.24-0.95, P=0.03).

CONCLUSION

TIMELY administration of adequately dosed treatment regimens and early ICU admission of critically ill patients could help in improving outcomes.

Risk factors for target non-attainment during empirical treatment with β-lactam antibiotics in critically ill patients

PURPOSE

Risk factors for β-lactam antibiotic underdosing in critically ill patients have not been described in large-scale studies. The objective of this study was to describe pharmacokinetic/pharmacodynamic (PK/PD) target non-attainment envisioning empirical dosing in critically ill patients and considering a worst-case scenario as well as to identify patient characteristics that are associated with target non-attainment.

METHODS

This analysis uses data from the DALI study, a prospective, multi-centre pharmacokinetic point-prevalence study. For this analysis, we assumed that these were the concentrations that would be reached during empirical dosing, and calculated target attainment using a hypothetical target minimum inhibitory concentration (MIC), namely the susceptibility breakpoint of the least susceptible organism for which that antibiotic is commonly used. PK/PD targets were free drug concentration maintained above the MIC of the suspected pathogen for at least 50 % and 100 % of the dosing interval respectively (50 % and 100 % f T (>MIC)). Multivariable analysis was performed to identify factors associated with inadequate antibiotic exposure.

RESULTS

A total of 343 critically ill patients receiving eight different β-lactam antibiotics were included. The median (interquartile range) age was 60 (47-73) years, APACHE II score was 18 (13-24). In the hypothetical situation of empirical dosing, antibiotic concentrations remained below the MIC during 50 % and 100 % of the dosing interval in 66 (19.2 %) and 142 (41.4 %) patients respectively. The use of intermittent infusion was significantly associated with increased risk of non-attainment for both targets; creatinine clearance was independently associated with not reaching the 100 % f T( >MIC) target.

CONCLUSIONS

This study found that-in empirical dosing and considering a worst--case scenario--19 % and 41 % of the patients would not achieve antibiotic concentrations above the MIC during 50 % and 100 % of the dosing interval. The use of intermittent infusion (compared to extended and continuous infusion) was the main determinant of non-attainment for both targets; increasing creatinine clearance was also associated with not attaining concentrations above the MIC for the whole dosing interval. In the light of this study from 68 ICUs across ten countries, we believe current empiric dosing recommendations for ICU patients are inadequate to effectively cover a broad range of susceptible organisms and need to be reconsidered.

Association of autophagy-related 16-like 1 (ATG16L1) gene polymorphism with sepsis severity in patients with sepsis and ventilator-associated pneumonia

Autophagy is a highly conserved mechanism of eukaryotic cells implicated in cell homeostasis and elimination of intracellular pathogens. Functional polymorphisms in genes encoding for autophagy have been associated with susceptibility to inflammatory and infectious diseases, but data on severe infections are missing. The aim of the present study was to assess whether polymorphisms in genes encoding proteins involved in autophagy influence susceptibility to ventilator-associated pneumonia (VAP). Mechanically ventilated patients with VAP were studied. Genotyping for autophagy-related 16-like 1 (ATG16L1, rs2241880) functional polymorphism was performed using the TaqMan single-nucleotide assay. Monocytes were isolated from patients and stimulated with lipopolysaccharide (LPS). Tumor necrosis factor-α (TNF-α) was measured in the supernatants of monocytes using an enzyme-linked immunosorbent assay. Procalcitonin (PCT) was also measured in the serum of patients by an immuno-time-resolved amplified cryptate technology assay. A total of 155 patients with VAP were enrolled in the study. Carriage of the minor A allele of ATG16L1 was associated with septic shock with at least one organ failure (odds ratio (OR): 2.40, p: 0.036). TNF-α production was significantly greater among the carriers of the polymorphism presenting with at least one organ failure (p: 0.040). PCT was increased upon worsening to septic shock and organ failure only among carriers of the minor frequency A alleles. In a homogeneous cohort of septic patients with VAP, the carriage of autophagy polymorphisms predisposes to VAP severity and septic shock development. This may be related with predisposition to immunoparalysis.

Variability in protein binding of teicoplanin and achievement of therapeutic drug monitoring targets in critically ill patients: lessons from the DALI Study

The aims of this study were to describe the variability in protein binding of teicoplanin in critically ill patients as well as the number of patients achieving therapeutic target concentrations. This report is part of the multinational pharmacokinetic DALI Study. Patients were sampled on a single day, with blood samples taken both at the midpoint and the end of the dosing interval. Total and unbound teicoplanin concentrations were assayed using validated chromatographic methods. The lower therapeutic range of teicoplanin was defined as total trough concentrations from 10 to 20 mg/L and the higher range as 10-30 mg/L. Thirteen critically ill patients were available for analysis. The following are the median (interquartile range) total and free concentrations (mg/L): midpoint, total 13.6 (11.2-26.0) and free 1.5 (0.7-2.5); trough, total 11.9 (10.2-22.7) and free 1.8 (0.6-2.6). The percentage free teicoplanin for the mid-dose and trough time points was 6.9% (4.5-15.6%) and 8.2% (5.5-16.4%), respectively. The correlation between total and free antibiotic concentrations was moderate for both the midpoint (ρ = 0.79, P = 0.0021) and trough (ρ = 0.63, P = 0.027). Only 42% and 58% of patients were in the lower and higher therapeutic ranges, respectively. In conclusion, use of standard dosing for teicoplanin leads to inappropriate concentrations in a high proportion of critically ill patients. Variability in teicoplanin protein binding is very high, placing significant doubt on the validity of total concentrations for therapeutic drug monitoring in critically ill patients.

Rituximab in critically ill patients

Rituximab is a monoclonal chimeric antibody used in the treatment of CD20-positive B-cell malignancies and rheumatoid arthritis. However, it is used in several other off-label indications including acute graft-versus-host disease. We sought to critically examine the role of rituximab in the treatment of acute graft versus host disease (aGVHD) in critically ill patients and the potential associations with infectious complications in transplant recipients.

Community acquired methicillin resistant Staphylococcus aureus pneumonia: an update for the emergency and intensive care physician

Pneumonia caused by community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) among individuals without healthcare-associated (HA) risk factors was first recognized a decade ago. CA-MRSA has now been established as a pathogen responsible for rapidly progressive, frequently fatal disease manifesting as necrotizing pneumonia, severe sepsis and necrotizing fasciitis. The frequency of occurrence, risk factors, and optimal treatment of CA-MRSA pneumonia remain unclear and vary significantly across countries. CA-MRSA is resistant to β-lactam antimicrobials due to the acquisition of novel methicillin resistance genetic cassettes. Additionally many CA-MRSA strains produce Panton-Valentine leukocidin (PVL), due to which they probably exceed the virulence of hospital-acquired MRSA isolates (HA-MRSA). CA-MRSA pneumonia requires early suspicion -especially in young otherwise healthy individuals with rapidly evolving clinical picture presenting with cavitary consolidation, bilateral infiltrates, pleural effusion and hemoptysis. Prompt hospitalization and aggressive treatment with intravenous antibiotics is warranted to improve outcomes. Therapeutic approach for severe CA-MRSA infections and particularly pneumonia is generally the same as that for invasive HA-MRSA infections. New anti-MRSA agents and possible combinations are of great importance to be evaluated in the future.

Anidulafungin for the treatment of candidaemia/invasive candidiasis in selected critically ill patients

A prospective, multicentre, phase IIIb study with an exploratory, open-label design was conducted to evaluate efficacy and safety of anidulafungin for the treatment of candidaemia/invasive candidiasis (C/IC) in specific ICU patient populations. Adult ICU patients with confirmed C/IC meeting ≥1 of the following criteria were enrolled: post-abdominal surgery, solid tumour, renal/hepatic insufficiency, solid organ transplant, neutropaenia, and age ≥65 years. Patients received anidulafungin (200 mg on day 1, 100 mg/day thereafter) for 10–42 days, optionally followed by oral voriconazole/fluconazole. The primary efficacy endpoint was global (clinical and microbiological) response at the end of all therapy (EOT). Secondary endpoints included global response at the end of intravenous therapy (EOIVT) and at 2 and 6 weeks post-EOT, survival at day 90, and incidence of adverse events (AEs). The primary efficacy analysis was performed in the modified intent-to-treat (MITT) population, excluding unknown/missing responses. The safety and MITT populations consisted of 216 and 170 patients, respectively. The most common pathogens were Candida albicans (55.9%), C. glabrata (14.7%) and C. parapsilosis (10.0%). Global success was 69.5% (107/154; 95% CI, 61.6–76.6) at EOT, 70.7% (111/157) at EOIVT, 60.2% (77/128) at 2 weeks post-EOT, and 50.5% (55/109) at 6 weeks post-EOT. When unknown/missing responses were included as failures, the respective success rates were 62.9%, 65.3%, 45.3% and 32.4%. Survival at day 90 was 53.8%. Treatment-related AEs occurred in 33/216 (15.3%) patients, four (1.9%) of whom had serious AEs. Anidulafungin was effective, safe and well tolerated for the treatment of C/IC in selected groups of ICU patients.

Colonization and infection by colistin-resistant Gram-negative bacteria in a cohort of critically ill patients

In recent years there has been renewed interest in colistin for the treatment of infections by multidrug-resistant Gram-negative bacteria, causing concern that increasing use may be accompanied by the emergence of resistance. This is a retrospective cohort study of colonization and infection by colistin-resistant (CR) gram-negative bacteria in critically ill patients. Colonization data were based on surveillance culture results. Among 150 patients, 78 (52%) were colonized by CR Gram-negative bacteria. Among them, 30 (20%) were colonized by Klebsiella pneumoniae isolates and 51 (34%) were colonized by intrinsically resistant to colistin (CIR) enterobacteriaceae. Seven cases of infection were caused by CR K. pneumoniae and 12 cases by CIR strains. The main risk factor for colonization by CR pathogens was colistin treatment.

TB or not TB: update from the ERS Respiratory Infection Assembly 10

Lower respiratory tract infections and tuberculosis represent some of the top health priorities in Europe. In the present report, the most recent advances in the field of disease control, clinical research and basic science of lower respiratory tract infections and tuberculosis are presented through analysis of some of the best abstracts presented at the 19th European Respiratory Society Congress in Vienna (Austria). Pathogenesis, diagnosis, treatment, prognostic factors and novel diagnostic techniques relevant for bacterial and viral infections, as well as new tools for the diagnosis of latent and active tuberculosis in different sub-groups of patients, are discussed. The growing epidemiological threat represented by multidrug-resistant and extensively drug-resistant tuberculosis cases is presented and its impact analysed.

The Gram-negative bacteria-binding protein gene family: its role in the innate immune system of anopheles gambiae and in anti-Plasmodium defence

Gram-negative bacteria-binding proteins (GNBPs) are pattern recognition receptors which contribute to the defensive response against Plasmodium infection in Anopheles. We have characterized the GNBP gene family in Anopheles gambiae at the molecular level, and show that they are functionally diverse components of the A. gambiae innate immune system. GNBPB4 is a major factor in the defence against a broad range of pathogens, while the other GNBPs have narrower defence specificities. GNBPB4 is associated with the regulation of immune signalling pathways and was found to interact with the Gram-negative Escherichia coli and weakly co-localized with Plasmodium berghei ookinetes in the mosquito midgut epithelium.

Heteroresistance: a concern of increasing clinical significance?

Recent studies have focused on issues related to heteroresistance, including its definition, methods of detection and frequency. Most such studies have reported data concerning infections caused by Staphylococcus aureus, but the clinical significance of heteroresistance is unclear. Six studies have described infections caused by S. aureus strains that were heteroresistant to vancomycin, with two suggesting an association between the emergence of heteroresistance and treatment failure or mortality, and four suggesting no such association. Further studies are required to evaluate the clinical implications of heteroresistance in an era in which rates of antimicrobial resistance are increasing alarmingly worldwide.

Open access World Wide Web resources on upper and lower respiratory tract infections

BACKGROUND

Respiratory tract infections represent a common problem in everyday practice. The development of the World Wide Web can assist clinicians and other medical care professionals in finding useful information on various clinical conditions, including upper and lower respiratory tract infections.

METHODS

To identify websites containing information for health care professionals on upper and lower respiratory tract infections, we searched popular search engines such as Google and Yahoo. We also reviewed the sites of major institutions as well as relevant organisations and professional societies and associations. Only those sites that included material in the English language, were open access and developed by a governmental and/or academic institution, or a national or international professional society or associations were included.

RESULTS

We selected 106 sites that provide information on upper respiratory tract infections and 67 sites that provide information on lower respiratory tract infections.

CONCLUSIONS

We tried to identify freely available Internet resources with relevant information on upper and lower respiratory tract infections. We believe that the list of relevant World Wide Web resources we generated may be useful as an educational tool for clinicians and trainees.

Candidemia in immunocompromised and immunocompetent critically ill patients: a prospective comparative study

The purpose of this study was to compare the risk factors, clinical manifestations, and outcome of candidemia in immunocompromised (IC) and nonimmunocompromised (NIC) critically ill patients. Data were collected prospectively over a 2-year period (02/2000–01/2002) from patients in a 25-bed, medical–surgical intensive care unit (ICU). Eligible for participation in this study were patients who developed candidemia during their ICU stay. Patients under antifungal therapy and with a confirmed systemic fungal infection prior to the diagnosis of candidemia were excluded. Cultures of blood, urine, and stool were performed for all patients in the study, and all patients underwent endoscopy/biopsy of the esophagus for detection of Candida. Smears and/or scrapings of oropharyngeal and esophageal lesions were examined for hyphae and/or pseudohyphae and were also cultured for yeasts. During the study period, 1,627 patients were hospitalized in the ICU, 57% for primary medical reasons and 43% for surgical reasons. After application of the study’s inclusion and exclusion criteria, 24 patients with candidemia (9 IC and 15 NIC) were analyzed. Total parenteral nutrition was more common in IC than in NIC patients (9/9 [100%] vs 8/15 [53%], p = 0.02). Oropharyngeal candidiasis was detected in 5 of 9 (55.5%) IC patients and in 1 of 15 (6.5%) NIC patients (p = 0.015). Esophageal candidiasis was also more common in IC than in NIC patients (4/9 [44%] vs 0/15 [0%], p = 0.012). Among the 9 IC patients, all except 2 died, resulting in a crude mortality of 78%; among the 15 NIC patients, 9 died, resulting in a crude mortality of 60% (p > 0.05). Autopsy was performed in two IC and in six NIC patients, with disseminated candidiasis found in one IC patient. Oropharyngeal and esophageal candidiasis are frequent in IC patients with candidemia. In contrast, this coexistence is rare in NIC critically ill patients with Candida bloodstream infections. A high mortality was noted in both IC and NIC critically ill patients with candidemia.

Idiopathic scoliosis: a transcranial magnetic stimulation study

STUDY DESIGN

Various neurophysiological parameters of the motor system were investigated in 43 female patients with Idiopathic Scoliosis (IS) and 31 sex and age matched controls using transcranial magnetic stimulation (TMS).

OBJECTIVE

To investigate whether asymmetries in excitatory and inhibitory brain processes, as studied by TMS, are a causative factor in IS.

SUMMARY OF BACKGROUND DATA

Previous studies associated IS with pathological asymmetries of the cerebral cortex and the brain stem at the level of the corticospinal tracts.

METHODS

Forty-three female patients with right IS and 31 normal female subjects entered the study. Various TMS parameters, including the study of ipsilateral pyramidal tract, were studied. Electrophysiological data were correlated with clinical data, the degrees of the scoliotic curve and the Perdriolle and Nash & Moe indexes.

RESULTS

In upper limbs, detailed testing failed to reveal any statistically significant differences between the patient and the control group. In lower limbs, side-to-side differences of central motor conduction time (CMCT) and facilitated cortical-to-muscle latencies were increased in the scoliotic patients (p<0.05). This finding correlated significantly with Nash & Moe and Perdriolle indexes (Spearman's r=0.406 and 0.575, respectively, p<0.05). Following the Bonferroni adjustment, however, differences in CMCT SSDs were not statistically significant (p>0.05).

CONCLUSION

The present TMS data do not support the concept of a generalized brain asymmetry in IS. In lower limbs, a trend towards increased asymmetries in side-to-side differences of CMCT and cortical latencies was detected probably representing subclinical involvement of the corticospinal tracts secondary to mechanical compression. Finally, it is concluded that non-decussation of the pyramidal tracts is not involved in the pathogenesis of IS.