Transcriptomic analysis reveals the cell membrane defense regulated by LiaX-FRS system in Lacticaseibacillus paracasei L9 under bile salt stress
Ontology highlight
ABSTRACT:
ORGANISM(S): Lacticaseibacillus paracasei
PROVIDER: GSE270722 | GEO | 2025/06/25
REPOSITORIES: GEO
Similar Datasets
Project description:In this study, we showed for the first time that c-di-AMP is produced by C. difficile and controls the uptake of potassium, making it essential for growth. We found that c-di-AMP is involved in biofilm formation, cell wall homeostasis, osmotolerance as well as detergent and bile salt resistance in C. difficile. We identified BusR as a new regulator that binds c-di-AMP and represses the expression of the compatible solute transporter BusAA-AB. Interestingly, a busR mutant is highly resistant to a hyperosmotic or bile salt stress compared to the parental strain while a busAA mutant is more susceptible. A short exposure of C. difficile cells to bile salts resulted in a decrease of the c-di-AMP concentrations reinforcing the hypothesis that changes in membrane characteristics due to variations of the cellular turgor or membrane damages constitute a signal for the adjustment of the intracellular c-di-AMP concentration. In a colonization mouse model, a strain producing elevated c-di-AMP concentrations failed to persist in the gut in contrast to the parental strain. Thus, c-di-AMP is a signaling molecule with pleiotropic effects that controls osmolyte uptake to confer osmotolerance and bile salt resistance in C. difficile and that is important for colonization of the host.
2021-12-27 | GSE192529 | GEO
Project description:Bbr_0838 from Bifidobacterium breve UCC2003 encodes a 683 residue membrane protein, that contains a permease domain displaying similarity to transporters belonging to the major facilitator superfamily, as well as a CBS (cystathionine beta synthase) domain. The high level of similarity to bile-efflux pumps from other bifidobacteria, suggests a significant role for Bbr_0838 in bile tolerance of B. breve UCC2003. Bbr_0838 transcription was shown to be monocistronic and strongly induced upon exposure to bile. Further analysis delineated the transcriptional start site and the minimal region required for promoter activity and bile regulation. Insertional inactivation of Bbr_0838 in B. breve UCC2003 resulted in a strain that exhibited reduced survival upon cholate exposure as compared to the parent strain, a phenotype that was reversed when a functional Bbr_0838 gene was introduced into UCC2003::838800. Transcriptome analysis of UCC2003::838800 grown in the presence or absence of bile demonstrated that transcription of Bbr_0832, which is predicted to encode a macrolide-efflux transporter gene, was significantly increased in the presence of bile, representing a likely compensatory mechanism for bile removal in the absence of Bbr_0838. This study represents the first in depth analysis of a bile-inducible locus in bifidobacteria, identifying a key gene relevant for bifidobacterial bile tolerance.
2012-02-20 | GSE31224 | GEO
Project description:Listeria monocytogenes is a gram-positive, facultative anaerobe food-borne pathogen that is the causative agent of listeriosis. Upon ingestion, L. monocytogenes is subjected to a variety of non-specific host defenses such as bile. The main component of bile is bile salts which is known to be bactericidal through inducing DNA damage, oxidative damage, membrane instability, and protein misfolding. Previous studies have focused mainly on aerobic conditions; however the human GI tract is an environment ranging from microaerophilic to anaerobic. The bile salt hydrolase, an enzyme known to reduce toxicity of bile through hydrolysis, has been shown to have an increase in activity under anaerobic conditions. Therefore, the purpose of this study was to determine the effect of oxygen on bile resistance and determine the bile specific proteome that is responsible for this. To do this, we performed survival assays on virulent strains: F2365, 10403S, EGDe and avirulent strain, HCC23. Results showed an increase in viability for all virulent strains when exposed to porcine bile under anaerobic conditions. Interestingly, an increase in resistance was seen in HCC23 only under aerobic conditions. We then used a total proteomic analysis approach to compare the bile specific proteome under both aerobic and anaerobic conditions. Results showed many difference between all strains including an increase in abundance of proteins associated with stress responses, repair, cell morphology, and cell division under anaerobic conditions. Response to bile salt stress showed to be strain dependent. This study not only identified proteins responsible for L. monocytogenes bile resistance but also differerences between aerobic and anaerobic conditions thus suggesting that oxygen availability is not only a stressor but in some way providing assistance to overcoming bile salts.
2017-05-03 | PXD002243 | Pride
Project description:Bbr_0838 from Bifidobacterium breve UCC2003 encodes a 683 residue membrane protein, that contains a permease domain displaying similarity to transporters belonging to the major facilitator superfamily, as well as a CBS (cystathionine beta synthase) domain. The high level of similarity to bile-efflux pumps from other bifidobacteria, suggests a significant role for Bbr_0838 in bile tolerance of B. breve UCC2003. Bbr_0838 transcription was shown to be monocistronic and strongly induced upon exposure to bile. Further analysis delineated the transcriptional start site and the minimal region required for promoter activity and bile regulation. Insertional inactivation of Bbr_0838 in B. breve UCC2003 resulted in a strain that exhibited reduced survival upon cholate exposure as compared to the parent strain, a phenotype that was reversed when a functional Bbr_0838 gene was introduced into UCC2003::838800. Transcriptome analysis of UCC2003::838800 grown in the presence or absence of bile demonstrated that transcription of Bbr_0832, which is predicted to encode a macrolide-efflux transporter gene, was significantly increased in the presence of bile, representing a likely compensatory mechanism for bile removal in the absence of Bbr_0838. This study represents the first in depth analysis of a bile-inducible locus in bifidobacteria, identifying a key gene relevant for bifidobacterial bile tolerance. In order to investigate differences in global gene expression upon growth or exposure of B. breve UCC2003-delta0838 to cholic acid compared to normal growing cells, DNA microarray experiments were performed. Total RNA was isolated from B. breve UCC2003-delta0838 cultures under normal conditions and cultures grown on or exposed to cholic acid. All experiments were performed in duplo and targets where confirmed with QRT-PCR. In addition transcriptome analyse was performed of B. breve UCC2003 compared to that of B. breve UCC2003-delta0838 both exposed to 0.1 % cholic acid. This was performed as a single experiment and targets were confirmed by QRT-PCR
2012-02-20 | E-GEOD-31224 | biostudies-arrayexpress
Project description:Enterohemorrhagic Escherichia coli (EHEC), including serotype O157:H7, cause severe food-borne illness. On route to the human colon, they encounter and resist, numerous anti-microbial ingestion stresses. We hypothesize that these stresses cue EHEC to alter virulence properties. This study investigated the impact of bile salts on virulence properties and examined the genetic basis of the phenotypes. Established assays were used to examine adhesion to human epithelial cells, motility, verotoxin (VT) production and antimicrobial resistance with/without bile salt stress. Bacteria treated for 90 minute in DMEM plus 0.15% (w/v) bile salt mix demonstrated significantly enhanced adhesion to epithelial cells and resistance to several antibiotics but did not increase motility or VT production. To determine the genetic basis of these phenotypes a microarray experiment was conducted. EHEC strain 86-24, in mid-log phase of growth, were grown in DMEM pH 7.4 (control), or DMEM plus bile salt mix (0.15% w/v), for 90 minutes, statically at 37˚C, 5% CO2 prior to harvesting RNA for the microarray study. Four biological replicates were produced for each treatment. Microarray and gene expression analysis (semi-quantitative RT-PCR and beta-galactosidase reporter assays) of bile salt-treated EHEC revealed significant up-regulation of genes for lipid A modification, fimbriae, an efflux pump, and a two-component regulatory system relative to the bacteria grown in DMEM alone. This work points to several mechanisms that EHEC employs to resist the stresses of the human small intestine, notably efflux, antimicrobial resistance, and outer membrane alterations. Bile salts enhanced the virulence-related properties of increased adhesion and resistance to antimicrobials but not VT production or motility. This research contributes to our understanding of how EHEC senses and responds to host environmental signals and the mechanisms this pathogen uses to successfully colonize and infect the human host. Bacteria were grown in LB broth overnight with shaking, then subcultured into DMEM and grown statically at 37˚C, 5%CO2 to mid-log phase. Bacteria were then subjected to one of two 90 minute treatments: 1) Control: DMEM pH 7.4, or 2) Bile Salt Stress: DMEM pH 7.4 plus 0.15%, grown statically at 37˚C, 5%CO2.
2011-09-05 | E-GEOD-22060 | biostudies-arrayexpress
Project description:Bile acids are not only crucial for the uptake of lipids, but also have widespread systematic ef-fects and shape the gut-microbiome composition. Bile acids can directly shape the gut-microbiome and can be modified by bacteria such as Eggerthella lenta which in turn plays a crucial role in host metabolism and immune response. We cultivated eight strains that represent a simplified human intestinal microbiome and inves-tigated the molecular response to bile acids, co-culturing with Eggerthella lenta and the combina-tion. We observed growth inhibition of particularly gram-positive strains during bile acid stress, which could be alleviated through co-culturing with Eggerthella lenta. The inhibition of growth was related to a decrease in membrane integrity and genotoxic effects of bile acids, which we investigated using zeta potential measurements in combination with proteomic and metabolomic analyses. Co-culturing with Eggerthella lenta alleviated stress through formation of oxidized and epimer-ized bile acids and the molecular response to co-culturing was seen to be strain specific. We also note that we could detect the recently described Microbial Bile Salt Conjugates in our cultures. This study highlights the significance of a potent bile acid modifier and how in-depth molecular analyses are required to decipher cross-communication between gut and host.
2023-02-24 | PXD035496 | Pride
Project description:Enterohemorrhagic Escherichia coli (EHEC), including serotype O157:H7, cause severe food-borne illness. On route to the human colon, they encounter and resist, numerous anti-microbial ingestion stresses. We hypothesize that these stresses cue EHEC to alter virulence properties. This study investigated the impact of bile salts on virulence properties and examined the genetic basis of the phenotypes. Established assays were used to examine adhesion to human epithelial cells, motility, verotoxin (VT) production and antimicrobial resistance with/without bile salt stress. Bacteria treated for 90 minute in DMEM plus 0.15% (w/v) bile salt mix demonstrated significantly enhanced adhesion to epithelial cells and resistance to several antibiotics but did not increase motility or VT production. To determine the genetic basis of these phenotypes a microarray experiment was conducted. EHEC strain 86-24, in mid-log phase of growth, were grown in DMEM pH 7.4 (control), or DMEM plus bile salt mix (0.15% w/v), for 90 minutes, statically at 37˚C, 5% CO2 prior to harvesting RNA for the microarray study. Four biological replicates were produced for each treatment. Microarray and gene expression analysis (semi-quantitative RT-PCR and beta-galactosidase reporter assays) of bile salt-treated EHEC revealed significant up-regulation of genes for lipid A modification, fimbriae, an efflux pump, and a two-component regulatory system relative to the bacteria grown in DMEM alone. This work points to several mechanisms that EHEC employs to resist the stresses of the human small intestine, notably efflux, antimicrobial resistance, and outer membrane alterations. Bile salts enhanced the virulence-related properties of increased adhesion and resistance to antimicrobials but not VT production or motility. This research contributes to our understanding of how EHEC senses and responds to host environmental signals and the mechanisms this pathogen uses to successfully colonize and infect the human host.
2011-09-06 | GSE22060 | GEO
Project description:Transcriptional profiling of probiotic Lactobacillus rhamnosus strain GG mid-exponential pH-controlled bioreactor cultures before and after exposure to bovine bile (0.2% ox gall). Keywords: bile, stress response
2011-01-01 | GSE22536 | GEO
Project description:Transcriptomic analysis reveals the cell membrane defense regulated by LiaX-FRS system in Lacticaseibacillus paracasei L9 under bile salt stress
| PRJNA1128080 | ENA
Project description:Bifidobacterium are considered to be beneficial for human health and are classified as probiotic bacterium. They must resist many environmental stress factors in order to survive in the gastrointestinal environment including; pH, oxygen availability, bile and nutrient starvation (eg: iron or carbon). This study investigates Bifidobacterium breve UCC2003 global genome response to growth under ferrous and/or ferric iron limiting conditions. Revealing that growth under iron limitation effects many processes in the cell including carbon and nitrogen metabolism and induces/reduces the expression of numerous genes; including multiple iron uptake systems, DPS proteins (which are predicted to be involved in iron storage/DNA protection), Fe-S cluster associated proteins and a bile salt hydrolase (bshB). Insertional mutagenesis and survival assays were employed and demonstrated that iron starvation imposed on B. breve UCC2003 results in an increased resistance to bile stress due to in part the iron-inducible transcription of the bshB gene. Furthermore, this study links BSH activity in B. breve UCC2003 to its ability to survive the deleterious effects of bile salt and suggest that B. breve UCC2003 may be use iron as a signal to adapt to the constantly changing environment within the small intestine.
2018-03-31 | GSE110080 | GEO