Project description:Sedation with benzodiazepines (BZs) has eventual side-effects proved to entail incremented risks for ventilator-associated pneumonia (VAP) (e.g. immunity alterations and nervous/mechanical responses increasing the aspiration of upper respiratory tract-colonizing bacteria), but some knowledge gaps on the topic exist. For instance, it has never been approached whether BZs could cause a modulation of intrinsic bacterial virulence, and/or influence the host-pathogen interaction in neglected contexts (e.g. respiratory epithelium features, or the lytic/opsonic activity of complement) to facilitate VAP development. Thus, to enrich the picture of factors contributing to the BZs-associated higher risk for VAP, we analyzed relevant in vitro, ex vivo and in vivo infection-related parameters to decipher whether they could be affected by these sedatives in the top VAP-causing pathogen Pseudomonas aeruginosa. While most variables were unaltered (including among others invertebrate infection assays and a rat model of VAP), a significantly attenuated pathogenic impact of infection on human respiratory A549 cells (invasion, cytotoxicity and inflammation reduced up to ≈50%) appeared upon BZ exposure at high therapeutic concentrations (diazepam/midazolam 10 µg/ml), potentially because of effects of the drugs mostly on the cultured cells. These facts could entail a BZs-associated stealth pathogen-like behavior of P. aeruginosa on the respiratory epithelium, consisting of a weak immune activation proportional to the mild damage caused, perhaps favoring VAP onset. Strikingly, BZs triggered a significantly increased biofilm formation (up to ≈2-fold > controls) on plastic plates and endotracheal tubes (supported by the upregulation of various biofilm-related genes and c-di-GMP accumulation), suggesting a groundbreaking idea: the BZ-dependent boosted formation of these P. aeruginosa sessile reservoirs, likely enabling bacterial release to deep airways and thus VAP progression. Animal models with prolonged sedation/ventilation periods should be conducted to confirm that BZs pose an added trigger for VAP through the surprising hitherto unknown phenomena revealed here.

Project description:INTRO: The ongoing challenge of accurately diagnosing infection in the ICU motivates a search for novel molecular diagnostics. In the current study, we tested the hypothesis that the informational content of circulating leukocytes differs, thereby allowing one to rank leukocyte populations on their potential to contribute to RNA diagnostics for pneumonia. METHODS: Sixteen patients (10 male, 6 female) at risk for VAP were entered into our IRB-approved study that collects blood and clinical data every 48 hours for up to 21 days. Four of the sixteen patients developed VAP as diagnosed and treated by the attending ICU physician. Previously reported blood protocols were used to isolate buffy coat, enriched neutrophil, and enriched monocyte populations by using negative selection. Cellular purity was assessed by FACS for one of the 4 VAP patients. Genome-wide expression analysis was performed on RMA-normalized signal from Affymetrix U133 2.0 Plus GeneChips. EDGE software (FDR=0.10) was used to determine changes in mRNA abundance over time for each cell population. RESULTS: During the 5-day window in which each of the four patients (all males) developed VAP, significant changes in gene expression were observed (Table 2), but the information content (number of genes altered) varied across leukocyte populations. These differences were not due to signal variance (coefficient of variation, CV) or differences in the number of samples available for analysis. Moreover, only 0.6% of the monocyte gene list overlaps with the neutrophil list, arguing that neutrophil contamination of monocyte populations is insufficient to explain the 40-fold difference in gene number. CONCLUSIONS: Enriched monocyte populations from circulating blood provide far more genes for study of the host response to VAP than the other 2 cell populations studied. This information should be considered when designing blood gene expression profiling experiments in patients at risk for sepsis. Keywords: time course Four patients over several timepoints measured three different cell types for VAP signal

Project description:INTRO: The ongoing challenge of accurately diagnosing infection in the ICU motivates a search for novel molecular diagnostics. In the current study, we tested the hypothesis that the informational content of circulating leukocytes differs, thereby allowing one to rank leukocyte populations on their potential to contribute to RNA diagnostics for pneumonia. METHODS: Sixteen patients (10 male, 6 female) at risk for VAP were entered into our IRB-approved study that collects blood and clinical data every 48 hours for up to 21 days. Four of the sixteen patients developed VAP as diagnosed and treated by the attending ICU physician. Previously reported blood protocols were used to isolate buffy coat, enriched neutrophil, and enriched monocyte populations by using negative selection. Cellular purity was assessed by FACS for one of the 4 VAP patients. Genome-wide expression analysis was performed on RMA-normalized signal from Affymetrix U133 2.0 Plus GeneChips. EDGE software (FDR=0.10) was used to determine changes in mRNA abundance over time for each cell population. RESULTS: During the 5-day window in which each of the four patients (all males) developed VAP, significant changes in gene expression were observed (Table 2), but the information content (number of genes altered) varied across leukocyte populations. These differences were not due to signal variance (coefficient of variation, CV) or differences in the number of samples available for analysis. Moreover, only 0.6% of the monocyte gene list overlaps with the neutrophil list, arguing that neutrophil contamination of monocyte populations is insufficient to explain the 40-fold difference in gene number. CONCLUSIONS: Enriched monocyte populations from circulating blood provide far more genes for study of the host response to VAP than the other 2 cell populations studied. This information should be considered when designing blood gene expression profiling experiments in patients at risk for sepsis. Keywords: time course

			Action	DRS
	SRR6787150.fastq.gz	Fastqsanger.gz
	SRR6787160.fastq.gz	Fastqsanger.gz
	SRR6787170.fastq.gz	Fastqsanger.gz
	SRR6787180.fastq.gz	Fastqsanger.gz
	SRR6787190.fastq.gz	Fastqsanger.gz

Dataset Information

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets