Ontology highlight
ABSTRACT:
PROVIDER: PRJNA638217 | ENA |
REPOSITORIES: ENA
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Project description:Diagnosis of acute infection in the critically ill remains a challenge. Changes in physiologic parameters and existing molecular diagnostics are not specific and microbiologic confirmation of infection can take days. As cellular first responders, preclinical studies indicate that circulating leukocytes are activated in response to bacterial infection, manifesting infection-specific transcriptional programs. We hypothesized that circulating leukocyte transcriptional profiles can be used to diagnose infection and monitor response to therapy in the critically ill. Experiment Overall Design: A translational research approach was employed. Fifteen mice underwent intratracheal (i.t.) injections of live P. aeruginosa, P. aeruginosa endotoxin, live S. pneumoniae, or normal saline. At 24 hours after injury, GeneChip microarray analysis of circulating buffy coat RNA identified 219 genes that distinguished between the pulmonary insults and differences in 7-day mortality. Similarly, buffy coat microarray expression profiles were generated from 20 mechanically ventilated patients every two days for up to three weeks; 11 of these patients developed pneumonia. Principal components analysis of the expression levels of the human orthologs for the mouse genes resulted in gene expression trajectories that describe the cohort of 11 patients as they develop, are treated for, and convalesce from ventilator-associated pneumonia (VAP). When the VAP microarray profiles were analyzed independently, 85 genes were identified with consistent changes in abundance during the seven days bracketing the diagnosis of VAP. The estimated prediction accuracy in this small patient cohort was 91%. The abundance of select transcripts was validated using real-time PCR. Principal components analysis of the average microarray-measured abundances of these genes defined a general trajectory (riboleukogram) for the onset of acute infection in this patient population. Individual riboleukograms demonstrated that the onset and course of infection are specific for each individual, but as patients recover from infection the riboleukograms converge. The gene ontologies of the co-expression networks indicate that leukocyte chemokines and granule maturation are especially informative for pneumonia diagnostics.
2008-04-09 | E-GEOD-6377 | biostudies-arrayexpress
Project description:Rationale: Patients in the intensive care unit (ICU) are frequently exposed to unnecessary antibiotics. Markers of the host response to infection may aid pneumonia diagnosis and avoid antibiotic-induced complications. Objective: To assess the host response to suspected bacterial pneumonia through assessment of alveolar neutrophilia and transcriptomic profiling of alveolar macrophages. Methods: We determined the test characteristics of BAL neutrophilia for the diagnosis of bacterial pneumonia in 3 cohorts of mechanically ventilated patients. In one cohort, we also isolated alveolar macrophages from BAL fluid and used the transcriptome to identify signatures of bacterial pneumonia. Finally, we developed a humanized mouse model of Pseudomonas aeruginosa pneumonia to determine if pathogen-specific signatures can be identified in human alveolar macrophages. Measurements and Main Results: BAL neutrophilia was highly sensitive for bacterial pneumonia in both the retrospective (N = 851) and validation cohorts (N = 76 and N = 79) with a negative predictive value of over 90% when BAL neutrophil percentage was less than 50%. A transcriptional signature of bacterial pneumonia was present in both resident and recruited macrophages. Gene signatures from both cell types identified patients with bacterial pneumonia with test characteristics similar to BAL neutrophilia. Conclusions: A BAL neutrophil percentage of less than 50% is highly sensitive for bacterial pneumonia. Informative transcriptomic signatures can be generated from BAL fluid obtained during routine clinical care in the ICU. The identification of novel host response biomarkers is a promising approach to aid the diagnosis and treatment of pneumonia.
2018-11-06 | GSE121871 | GEO
Project description:Engineered live bacteria could provide a new modality for treating lung infections , a major cause of mortality worldwide. Here, we engineered a genome-reduced human lung bacterium, Mycoplasma pneumoniae, to treat ventilator-associated pneumonia (VAP), a disease with high hospital mortality when associated with Pseudomonas aeruginosa biofilms. After validating the biosafety of an attenuated M. pneumoniae chassis in mice, we introduced four transgenes in the chromosome by transposition, to implement bactericidal and biofilm degradation activities. We show that this engineered strain has high efficacy against an acute P. aeruginosa lung infection in a mouse model. In addition, we demonstrate that the engineered strain can dissolve biofilms formed in endotracheal tubes of VAP patients and can be combined with antibiotics targeting the peptidoglycan layer to increase efficacy against gram-positive and gram-negative bacteria. We expect that our
2023-10-24 | PXD037233 | Pride
Project description:Ventilator-associated pneumonia (VAP) is a healthcare-acquired infection arising from the invasion of the lower respiratory tract by opportunistic pathogens in ventilated patients. The current method of diagnosis requires the culture of an airway sample such as bronchoalveolar lavage, which is invasive to obtain and may take up to seven days to identify a causal pathogen, or indeed rule out infection. While awaiting results, patients are administered empirical antibiotics; risks of this approach include lack of effect on the causal pathogen, contribution to the development of antibiotic resistance and downstream effects such as increased length of intensive care stay, cost, morbidity and mortality. Specific biomarkers which could identify causal pathogens in a timely manner are needed as they would allow judicious use of the most appropriate antimicrobial therapy. Volatile organic compound (VOC) analysis in exhaled breath is proposed as an alternative due to its non-invasive nature and its potential to provide rapid diagnosis at the patient's bedside. VOCs in exhaled breath originate from exogenous, endogenous, as well as microbial sources. To identify potential markers, VAP-associated pathogens Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus were cultured in both artificial sputum medium and nutrient broth, and their headspaces were sampled and analysed for VOCs. Previously reported volatile markers were identified in this study, including indole and 1-undecene, alongside compounds that are novel to this investigation, cyclopentanone and 1-hexanol. We further investigated media components (substrates) to identify those that are essential for indole and cyclopentanone production, with potential implications for understanding microbial metabolism in the lung.
2018-08-08 | MTBLS497 | MetaboLights
Project description:Objective: Identify genes that are differentially expressed between critically ill trauma patients who go on to develop ventilator-associated pneumonia (VAP) compared to similar patients who do not develop VAP Using gene expression differences, develop a model that predicts which patients are at greater risk of developing VAP. Prospective observational study, analysis of gene expression in 20 patient samples, 10 that developed ventilator-associated pneumonia, 10 that did not
2013-01-01 | E-GEOD-30385 | biostudies-arrayexpress
Project description:The onset of an infection-specific transcriptional program precedes the clinical diagnosis in patients who developed Ventilator-associated pneumonia (VAP). Ventilator-associated tracheobronchitis (VAT) is another respiratory infection affecting<br><br>outcomes in intubated patients, but interactions between VAT and VAP remains unknown.
2011-11-19 | E-MEXP-3001 | biostudies-arrayexpress
Project description:This project was a prospective translational study aimed at evaluating gene expression profiles (GEP) of patients with ventilator-associated pneumonia (VAP) . GEP of VAP were compared with a control group of patients which did not developed ventilator-associated lower respiratory tract infection despite being subjected to mechanical ventilation.
2018-01-31 | E-MTAB-5638 | biostudies-arrayexpress