Salmonella enterica subsp. enterica serovar Typhimurium str. LT2
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ABSTRACT:
PROVIDER: PRJNA203730 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To investigate the response of S. pneumoniae to three distinct antimicrobial peptides (AMPs), i.e. bacitracin, nisin and LL-37, transcriptome analysis of challenged bacteria was performed. Only a limited number of genes was found to be up- or down-regulated in all cases. Several of these common highly induced genes were chosen for further analysis, i.e. SP0385-0387, SP0912-0913, SP0785-0787, SP1714-1715 and the blp cluster. Deletion of these genes in combination with MIC determinations showed that several putative transporters, i.e. SP0785-0787 and SP0912-0913, were indeed involved in resistance to lincomycin, LL-37 and to bacitracin, nisin, lincomycin, respectively. Mutation of blp-bacteriocin production and its immunity genes resulted in an increased of sensitivity to LL-37. Interestingly, a putative ABC transporter (SP1715) protected against bacitracin and Hoechst 33342, but confered sensitivity to LL-37. A GntR-like regulator, SP1714, was identified as a negative regulator of itself and two of the putative transporters. In conclusion, we show that resistance to three different AMPs in S. pneumoniae is mediated by several putative ABC transporters, some of which have not been associated with antimicrobial resistance in this organism before. In addition, a GntR-like regulator was identified, which regulates two of these transporters. Our findings extend the undertstanding of defense mechanisms of this important human pathogen against antimicrobial compounds and points toward novel proteins, i.e. putative ABC transporters, which can be used as targets for the development of new antimicrobials.
2010-01-08 | GSE16491 | GEO
Project description:Secreted antimicrobial peptides (AMPs) are an important part of the human innate immune system and prevent local and systemic infections by inhibiting bacterial growth in a concentration dependent manner. In the respiratory tract, the cationic peptide LL-37 is one of the most abundant AMPs and capable of building pore complexes in usually negatively charged bacterial membranes, leading to destruction of bacteria. However, adaptation mechanisms of several pathogens to LL-37 are already described and are known to weaken the antimicrobial effect of the AMP, for instance, by repulsion, export or degradation of the peptide. This study examines proteome wide changes in Streptococcus pneumoniae D39, the leading cause of bacterial pneumonia, in response to physiological concentrations of LL-37 by high resolution mass spectrometry. Our data indicate that pneumococci may use some of the known adaptation mechanisms to reduce the effect of LL-37 on their physiology, too. Additionally, several proteins seem to be involved in resistance to AMPs which have not been related to this process before, such as the teichoic acid flippase TacF (SPD_1128). Understanding colonization and infection relevant adaptations of the pneumococcus to AMPs, especially LL-37, could finally uncover new drug targets to weaken the burden of this widespread pathogen.
2020-03-19 | PXD016511 | Pride
Project description:The antimicrobial peptide human Beta Defensin 3 (hBD3) is an essential part of the innate immune system and involved in protection against respiratory pathogens by specifically permeabilizing bacterial membranes. The Gram-positive bacterium S. pneumoniae causes serious diseases including pneumonia, meningitis, and septicemia despite being frequently exposed to human defense molecules including hBD3 during colonization and infection. Thus, the question arises how pneumococci adapt to stress caused by antimicrobial peptides. We addressed this subject by analyzing the proteome of S. pneumoniae after treatment with hBD3 and compared our data with the proteomic changes induced by LL-37, another crucial antimicrobial peptide present in the human respiratory tract. As antimicrobial peptides usually cause membrane perturbations, the response to the membrane active cationic detergent cetyl trimethyl ammonium bromide (CTAB) was examined to assess the specificity of the pneumococcal response to antimicrobial peptides. In brief, hBD3 and LL-37 induce a similar response in pneumococci especially in changes of proteins with annotated transporter and virulence function. However, LL-37 causes changes in abundance of cell surface modification proteins that cannot be observed after treatment with hBD3. Interestingly, CTAB induces unique proteomic changes in S. pneumoniae. Though, the detergent seems to activate a two-component system that is also activated in response to antimicrobial peptide stress (TCS 05). Overall, our publicly available data represent a novel resource on pneumococcal adaptation to specific cell surface stresses on a functional level. This knowledge can potentially be used to develop strategies to circumvent pneumococcal resistance to antimicrobial peptides.
2020-11-02 | PXD020968 | Pride
Project description:Aspergillus fumigatus contributes to invasive and allergic pulmonary disease in immunocompromised individuals. The pulmonary mucus of cystic fibrosis (CF) patients displays elevated levels of the pleiotropic cathelicidin antimicrobial peptide LL-37 and the aim of this work was to assess the effect of LL-37 on the growth A. fumigatus. Exposure of A. fumigatus conidia to high concentrations of intact LL-37 (100 μg/ml) for 24 hours had a positive effect on growth (277.45 ± 22.59% (p < 0.01)) whereas scrambled LL-37 (76.45 ± 7.46%) did not. Exposure of 24 hour pre-formed mycelium to 5 μg/ml LL-37 for 48 hours increased hyphal wet weight significantly (4.37 ± 0.23 g, p < 0.001) compared to the control (2.67 ± 0.05 g). Amino acid leakage from mycelium was observed in the presence of LL-37 and gliotoxin secretion was increased at 24 hours from LL-37 exposed hyphae (169.1 ± 6.36 ng/mg hyphae, p < 0.05) compared to the control (102 ± 18.81 ng/mg hyphae). Quantitative proteomic analysis of 24 hour LL-37 treated hyphae revealed an increase in the abundance of proteins associated with growth (eIF-5A (16.3 fold increased), tissue degradation (aspartic endopeptidase (4.7 fold increased)) and allergic reactions (Asp F13 (10 fold increased)). By 48 hours there was an increase in proteins indicative of cellular stress (glutathione peroxidase (9 fold increased)), growth (eIF-5A (6 fold increased), and virulence (ribonuclease mitogillin (3.7 fold increased). These results indicate that LL-37 stimulates A. fumigatus growth and this may result in increased fungal growth and secretion of toxins in the lungs of CF patients.
2018-05-22 | PXD008143 | Pride
Project description:Raw and processed data from FPOP analysis of bovine indolicidin and human LL-37 antimicrobial peptides with nanodiscs composed of DMPC, DMPG, or E. coli polar lipid extract. Data is provided for both oxidized samples and control samples with no exposure to the UV laser.
| MSV000088174 | MassIVE
Project description:Gene expression in THP-1 cells treated for 6 hours with CNT and GNP conjugated with LL-37, LL-37 spiked as well as free LL-37: Reference (Total RNA Mixture of all samples) vs. treated cells
2017-06-17 | GSE98630 | GEO
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of early-onset neonatal bacterial infection. Evasion of innate immune defenses is critical to neonatal GBS disease pathogenesis. Effectors of the innate immune system such as antimicrobial peptides, as well as numerous antibiotics, target the peptidoglycan layer of the gram positive bacterial cell wall. The intramembrane-sensing histidine kinase class of two-component regulatory systems has recently been identified as important to the gram-positive response to cell wall stress. We identified and characterized the GBS homolog of LiaR, the response regulator component of the LiaFSR system and constructed site-directed, non-polar deletion mutations in the regulator gene liaR. GBS LiaR deletion mutant strains are more susceptible to cell wall active antibiotics (vancomycin and bacitracin) as well as antimicrobial peptides (colistin, nisin and the human cathelicidin LL-37) compared to isogenic wild-type GBS. LiaR mutant GBS are significantly attenuated in mouse models of both GBS sepsis and GBS pneumonia. To determine the genes regulated by LiaR that account for these defects, transcriptional profiling was performed using DNA microarray analysis, comparing wild-type GBS to LiaR mutant GBS under non-stressed conditions.
2012-11-18 | GSE14571 | GEO
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of early-onset neonatal bacterial infection. Evasion of innate immune defenses is critical to neonatal GBS disease pathogenesis. Effectors of the innate immune system such as antimicrobial peptides, as well as numerous antibiotics, target the peptidoglycan layer of the gram positive bacterial cell wall. The intramembrane-sensing histidine kinase class of two-component regulatory systems has recently been identified as important to the gram-positive response to cell wall stress. We identified and characterized the GBS homolog of LiaR, the response regulator component of the LiaFSR system and constructed site-directed, non-polar deletion mutations in the regulator gene liaR. GBS LiaR deletion mutant strains are more susceptible to cell wall active antibiotics (vancomycin and bacitracin) as well as antimicrobial peptides (colistin, nisin and the human cathelicidin LL-37) compared to isogenic wild-type GBS. LiaR mutant GBS are significantly attenuated in mouse models of both GBS sepsis and GBS pneumonia. To determine the genes regulated by LiaR that account for these defects, transcriptional profiling was performed using DNA microarray analysis, comparing wild-type GBS to LiaR mutant GBS under non-stressed conditions. Two separate RNA samples were extracted for each condition. One flip-dye replicate (2 hybridizations) was obtained for each pair of RNA samples for 4 hybridizations total.
2012-11-18 | E-GEOD-14571 | biostudies-arrayexpress
Project description:To identify the potential LL-37-responsed genes, we treated cells with or without LL-37 and their correspondent transcriptional profiles were compared. Total 104 significant genes were identified. Among them, 70 genes are upregulated in repsonse to LL-37 while 34 genes are downregulated in comparison with the control cells.
2016-03-11 | GSE45177 | GEO
Project description:To identify the potential LL-37-responsed genes, we treated cells with or without LL-37 and their correspondent transcriptional profiles were compared. Total 104 significant genes were identified. Among them, 70 genes are upregulated in repsonse to LL-37 while 34 genes are downregulated in comparison with the control cells. LL-37 responsed gene was measured after 3 h growth in YPD followed by 30 min of incubation in the presence of 5 ug/ml LL-37 in RPMI. Two batches of five independent experiments were performed.
2016-03-11 | E-GEOD-45177 | biostudies-arrayexpress