Long-term adaptation of S. aureus in CF patients
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Project description:Long-term adaptation of S. aureus in CF patients
| PRJEB5528 | ENA
Project description:Staphylococcus aureus is one of the first and most prevalent pathogens cultured from the airways of cystic fibrosis (CF) patients, which can persist there for extended periods. Airway infections in CF patients are characterized by a strong inflammatory response of highly recruited neutrophils. One killing mechanism of neutrophils is the formation of neutrophil extracellular traps (NETs), which capture and eradicate bacteria by extracellular fibers of neutrophil chromatin decorated with antimicrobial granule proteins. S. aureus secretes nuclease, which can degrade NETs. We hypothesized, that S. aureus adapts to the airways of CF patients during persistent infection by escaping from NET-mediated killing via an increase of nuclease activity. Sputum samples of CF patients with chronic S. aureus infection were visualized by confocal microscopy after immuno-fluorescence staining for NET-specific markers, S. aureus bacteria and overall DNA structures. Nuclease activity was analyzed in sequential isogenic long persisting S. aureus isolates, as confirmed by whole genome sequencing, from an individual CF patient using a FRET-based nuclease activity assay. Additionally, some of these isolates were selected and analyzed by qRT-PCR to determine the expression of nuc1 and regulators of interest. NET-killing assays were performed with clinical S. aureus isolates to evaluate killing and bacterial survival depending on nuclease activity. To confirm the role of nuclease during NET-mediated killing, a clinical isolate with low nuclease activity was transformed with a nuclease expression vector (pCM28nuc). Furthermore, two sputa from an individual CF patient were subjected to RNA-sequence analysis to evaluate the activity of nuclease in vivo. In sputa, S. aureus was associated to extracellular DNA structures. Nuclease activity in clinical S. aureus isolates increased in a time-and phenotype-dependent manner. In the clinical isolates, the expression of nuc1 was inversely correlated to the activity of agr and was independent of saeS. NET-mediated killing was significantly higher in S. aureus isolates with low compared to isolates with high nuclease activity. Importantly, transformation of the clinical isolate with low nuclease activity with pCM28nuc conferred protection against NET-mediated killing confirming the beneficial role of nuclease for protection against NETs. Also, nuclease expression in in vivo sputa was high, which underlines the important role of nuclease within the highly inflamed CF airways. In conclusion, our data show that S. aureus adapts to the neutrophil-rich environment of CF airways with increasing nuclease expression most likely to avoid NET-killing during long-term persistence.
2019-11-01 | GSE139662 | GEO
Project description:Microbes are responsible for cycling carbon (C) through soils, and predicted changes in soil C stocks under climate change are highly sensitive to shifts in the mechanisms assumed to control the microbial physiological response to warming. Two mecha-nisms have been suggested to explain the long-term warming impact on microbial physiology: microbial thermal acclimation and changes in the quantity and quality of substrates available for microbial metabolism. Yet studies disentangling these two mechanisms are lacking. To resolve the drivers of changes in microbial physiology in response to long-term warming, we sampled soils from 13- and 28-year- old soil warming experiments in different seasons. We performed short-term laboratory incubations across a range of temperatures to measure the relationships between temperature sensitivity of physiology (growth, respiration, carbon use efficiency, and extracellular enzyme activity) and the chemical composition of soil organic matter. We observed apparent thermal acclimation of microbial respiration, but only in sum-mer, when warming had exacerbated the seasonally-induced, already small dissolved organic matter pools. Irrespective of warming, greater quantity and quality of soil carbon increased the extracellular enzymatic pool and its temperature sensitivity. We propose that fresh litter input into the system seasonally cancels apparent thermal acclimation of C-cycling processes to decadal warming. Our findings reveal that long-term warming has indirectly affected microbial physiology via reduced C availability in this system, implying that earth system models including these negative feedbacks may be best suited to describe long-term warming effects on these soils. Citation: Domeignoz-Horta LA, Pold G, Erb H, Sebag D, Verrecchia E, Northen T, Louie K, Eloe-Fadrosh E, Pennacchio C, Knorr MA, Frey SD, Melillo JM, DeAngelis KM. Substrate availability and not thermal acclimation controls microbial temperature sensitivity response to long-term warming. Glob Chang Biol. 2023 Mar;29(6):1574-1590. doi: 10.1111/gcb.16544.
The work (proposal:https://doi.org/10.46936/10.25585/60001340) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
2023-08-04 | MSV000092599 | MassIVE
Project description:To provide a more detailed survey of adaptive changes in the physiology of P. aeruginosa (PA) during long-term infection of the cystic fibrosis (CF) lung, we performed a comparative proteome and transcriptome analysis of a set of isogenic sequential non-mutator and mutator isolates from three selected CF patients. Recently, we showed that during CF lung persistence PA mutators converge to a virulence-attenuated phenotype. In this study, we demonstrate that besides virulence-associated traits (VATs) the adaptation process of PA predominantly comprises metabolic pathways. In end-stage mutator strains, transcripts of genes encoding VATs, chemotaxis, degradation of aromatic compounds and several two-component regulatory systems were decreased. In contrast, several transcripts of genes or proteins involved in metabolism of fatty acids, nucleotides, amino acids and the generation of energy were increased. Of particular interest is the increased expression level of genes involved in (i) the anaerobic arginine-deiminase pathway, (ii) the anaerobic respiration such as nitrate-uptake protein OprF, redox-active azurin and cytchrome c551 peroxidase, (iii) the micro-aerobic respiration such as high oxygen-affinity cytochrome oxidase cbb3 (iv) the tricarboxylic acid cycle (TCA), glyoxylate shunt and anaplerotic carboxylation reactions to oxaloacetate. Strikingly, an increased transcription of the anaerobic regulator gene anr correlates with the up-regulation of ANR-dependent genes. In conclusion, these changes in transcriptome and proteome indicate an adaptive shift towards constitutive expression of genes of metabolic pathways obviously required for growth under micro-aerobic and nutritional conditions of suppurative CF lung tissue. Finally, these results provide us with new targets for antimicrobial agents and biomarkers reflecting adaptation of PA towards progressive CF lung disease. Experiment Overall Design: P. aeruginosa isolates recovered from different time points of chronic cystic fibrosis lung disease were cultered in vitro, harvested for RNA extraction and hybridization on Affymetrix microarrays. We compared the transcriptome (triplicate microarrays) of early non-mutator P. aeruginosa isolates with late mutator isolates with high mutation frequency probably the driving force of an efficient adaptation to changing environements to conclude from differences in gene expression to the requirements of CF lung environment. Experiment Overall Design: Second publication of array data to be added later
2009-06-08 | E-GEOD-10362 | biostudies-arrayexpress
Project description:To provide a more detailed survey of adaptive changes in the physiology of P. aeruginosa (PA) during long-term infection of the cystic fibrosis (CF) lung, we performed a comparative proteome and transcriptome analysis of a set of isogenic sequential non-mutator and mutator isolates from three selected CF patients. Recently, we showed that during CF lung persistence PA mutators converge to a virulence-attenuated phenotype. In this study, we demonstrate that besides virulence-associated traits (VATs) the adaptation process of PA predominantly comprises metabolic pathways. In end-stage mutator strains, transcripts of genes encoding VATs, chemotaxis, degradation of aromatic compounds and several two-component regulatory systems were decreased. In contrast, several transcripts of genes or proteins involved in metabolism of fatty acids, nucleotides, amino acids and the generation of energy were increased. Of particular interest is the increased expression level of genes involved in (i) the anaerobic arginine-deiminase pathway, (ii) the anaerobic respiration such as nitrate-uptake protein OprF, redox-active azurin and cytchrome c551 peroxidase, (iii) the micro-aerobic respiration such as high oxygen-affinity cytochrome oxidase cbb3 (iv) the tricarboxylic acid cycle (TCA), glyoxylate shunt and anaplerotic carboxylation reactions to oxaloacetate. Strikingly, an increased transcription of the anaerobic regulator gene anr correlates with the up-regulation of ANR-dependent genes. In conclusion, these changes in transcriptome and proteome indicate an adaptive shift towards constitutive expression of genes of metabolic pathways obviously required for growth under micro-aerobic and nutritional conditions of suppurative CF lung tissue. Finally, these results provide us with new targets for antimicrobial agents and biomarkers reflecting adaptation of PA towards progressive CF lung disease. Keywords: in vitro study/interstrain comparison/clinical isolates/early nonmutator vs. late mutator; variable time point of isolation from cf respiratory secretions
2009-05-26 | GSE10362 | GEO
Project description:Microbes are responsible for cycling carbon (C) through soils, and predicted changes in soil C stocks under climate change are highly sensitive to shifts in the mechanisms assumed to control the microbial physiological response to warming. Two mecha-nisms have been suggested to explain the long-term warming impact on microbial physiology: microbial thermal acclimation and changes in the quantity and quality of substrates available for microbial metabolism. Yet studies disentangling these two mechanisms are lacking. To resolve the drivers of changes in microbial physiology in response to long-term warming, we sampled soils from 13- and 28-year- old soil warming experiments in different seasons. We performed short-term laboratory incubations across a range of temperatures to measure the relationships between temperature sensitivity of physiology (growth, respiration, carbon use efficiency, and extracellular enzyme activity) and the chemical composition of soil organic matter. We observed apparent thermal acclimation of microbial respiration, but only in sum-mer, when warming had exacerbated the seasonally-induced, already small dissolved organic matter pools. Irrespective of warming, greater quantity and quality of soil carbon increased the extracellular enzymatic pool and its temperature sensitivity. We propose that fresh litter input into the system seasonally cancels apparent thermal acclimation of C-cycling processes to decadal warming. Our findings reveal that long-term warming has indirectly affected microbial physiology via reduced C availability in this system, implying that earth system models including these negative feedbacks may be best suited to describe long-term warming effects on these soils. Citation: Domeignoz-Horta LA, Pold G, Erb H, Sebag D, Verrecchia E, Northen T, Louie K, Eloe-Fadrosh E, Pennacchio C, Knorr MA, Frey SD, Melillo JM, DeAngelis KM. Substrate availability and not thermal acclimation controls microbial temperature sensitivity response to long-term warming. Glob Chang Biol. 2023 Mar;29(6):1574-1590. doi: 10.1111/gcb.16544.
The work (proposal:https://doi.org/10.46936/10.25585/60001340) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
2023-08-04 | MSV000092599 | GNPS
Project description:Some intracellular bacteria are known to cause long-term infections for periods of time that last decades without compromising the viability of the host. Although of critical importance, the changes that intracellular bacteria suffer during this long process of residence in a host cell environment remain obscure. Here, we report an experimental approach to study the adaptations of intracellular mycobacteria forced by a long-term intracellular lifestyle. Long-term infection of host macrophages with mycobacteria was maintained for a period of years. Mycobacteria in the long-term infected macrophages underwent an adaptation process leading to impaired phenolic glycolipids (PGL) synthesis, preference for glucose as a carbon source and neutral lipids accumulation. These changes correlated with increased survival of mycobacteria in macrophages and mice during re-infection and specific expression of stress- and survival-related genes. Our findings identify bacterial traits implicated in the establishment of long-term cellular infections and represent a tool for understanding the physiological states of bacteria living in fluctuating intracellular environments.
2014-12-31 | GSE49976 | GEO
Project description:Background: Chronic lung infection of cystic fibrosis (CF) patients by Staphylococcus aureus is a well-established epidemiological fact. Indeed, S. aureus is the most commonly identified pathogen in the lungs of CF patients. Strikingly the molecular mechanisms underlying S. aureus persistency are not understood. Methods: To gain insights into S. aureus adaptation to CF lungs, we selected pairs of sequential S. aureus isolates from 3 patients with CF and from one patient with non-CF chronic lung disease. We used a combination of genomic, proteomic and metabolomic approaches with functional assays for in-depth characterization of S. aureus long-term persistence during chronic lung infection. Results: For the first time, we show that late S. aureus isolates from CF patients have an increased ability for intracellular survival in CFBE-F508del cells compared to ancestral early isolates. Importantly, the increased ability to persist intracellularly was confirmed for S. aureus isolates within the own patient F508del epithelial cells. An increased ability to form biofilm was also demonstrated. Furthermore, to explain observed phenotypic adaptations, we identified the underlying genetic modifications inducing altered protein expression profiles and notable metabolic changes. These modifications affect several metabolic pathways (e.g., pantothenate and fatty acids) and virulence regulators (encoded by agr and sae loci) that could constitute therapeutic targets. Conclusions: Our results strongly suggest that the intracellular environment might constitute an important niche of persistence and relapse necessitating adapted antibiotic treatments.
2021-03-29 | PXD011281 | Pride
Project description:Our paper presents the results of a study in which we used whole genome bisulfite sequencing (WGBS) and RNA-Seq (i.e. transcriptomics) to examine the long-term epigenomic dynamics of an experimenta evolution study under high CO2 in the marine cyanobacterium Trichodesmium. We identify m5C methylated sites that rapidly change in response to short-term high CO2 exposure, which are then maintained for 4.5 years even after adaptation (i.e. trait canalization). After 7 years of CO2 selection, high-CO2 triggered methylation levels return to ancestral, low-CO2 levels, consistent with genetic assimilation theory and observations in eukaryotic model systems. These data suggest a potential role for m5C methylation in prokaryotic trait canalization and identify genetic assimilation as an evolutionary mechanism of potential biogeochemical importance under global change factors.
2020-08-18 | GSE138171 | GEO