A manganese-independent aldolase enables Staphylococcus aureus to resist host-imposed metal starvation
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus aureus
PROVIDER: GSE202268 | GEO | 2022/12/19
REPOSITORIES: GEO
Similar Datasets
Project description:During infection the host imposes manganese and zinc starvation on invading pathogens. Despite this, Staphylococcus aureus and other successful pathogens remain capable of causing devastating disease. However, how these invaders adapt to host-imposed metal starvation and overcome nutritional immunity remains unknown. We report that ArlRS, a global staphylococcal virulence regulator, enhances the ability of S. aureus to grow in the presence of the manganese-and zinc-binding innate immune effector calprotectin. Utilization of calprotectin variants with altered metal binding properties revealed that strains lacking ArlRS are specifically more sensitive to manganese starvation. Loss of ArlRS did not alter the expression of manganese importers or prevent S. aureus from acquiring metals. It did, however, alter staphylococcal metabolism and impair the ability of S. aureus to grow on amino acids. Further studies suggested that relative to consuming glucose, the preferred carbon source of S. aureus, utilizing amino acids reduced the cellular demand for manganese. When forced to use glucose as the sole carbon source S. aureus became more sensitive to calprotectin compared to when amino acids are provided. Infection experiments utilizing wild type and calprotectin-deficient mice, which have defects in manganese sequestration, revealed that ArlRS is important for disease when manganese availability is restricted but not when this essential nutrient is freely available. In total, these results indicate that altering cellular metabolism contributes to the ability of pathogens to resist manganese starvation and that ArlRS enables S. aureus to overcome nutritional immunity by facilitating this adaptation.
| S-EPMC5130280 | biostudies-literature
Project description:The host restricts the availability of zinc to prevent infection. To overcome this defense, Staphylococcus aureus and Pseudomonas aeruginosa rely on zincophore-dependent zinc importers. Synthesis of the zincophore staphylopine by S. aureus and its import are both necessary for the bacterium to cause infection. In this study, we sought to elucidate how loss of zincophore efflux impacts bacterial resistance to host-imposed zinc starvation. In culture and during infection, mutants lacking CntE, the staphylopine efflux pump, were more sensitive to zinc starvation imposed by the metal-binding immune effector calprotectin than those lacking the ability to import staphylopine. However, disruption of staphylopine synthesis reversed the enhanced sensitivity phenotype of the ΔcntE mutant to calprotectin, indicating that intracellular toxicity of staphylopine is more detrimental than the impaired ability to acquire zinc. Unexpectedly, intracellular accumulation of staphylopine does not increase the expression of metal importers or alter cellular metal concentrations, suggesting that, contrary to prevailing models, the toxicity associated with staphylopine is not strictly due to intracellular chelation of metals. As P. aeruginosa and other pathogens produce zincophores with similar chemistry, our observations on the crucial importance of zincophore efflux are likely to be broadly relevant.IMPORTANCEStaphylococcus aureus and many other bacterial pathogens rely on metal-binding small molecules to obtain the essential metal zinc during infection. In this study, we reveal that export of these small molecules is critical for overcoming host-imposed metal starvation during infection and prevents toxicity due to accumulation of the metal-binding molecule within the cell. Surprisingly, we found that intracellular toxicity of the molecule is not due to chelation of cellular metals.
| S-EPMC7148132 | biostudies-literature
Project description:ArlRS is a two-component regulatory system in Staphylococcus aureus. Here we use RNA-sequencing to compare gene expression in a wild-type USA300 strain and an isogenic arlRS mutant.
2020-04-29 | GSE130887 | GEO
Project description:The human opportunistic pathogen Staphylococcus aureus produces numerous small regulatory RNAs (sRNAs) for which functions are still poorly understood. Here, we focused on an atypical and large sRNA called RsaC. Its length varies between different isolates due to the presence of repeated sequences at the 5' end while its 3' part is structurally independent and highly conserved. Using MS2-affinity purification coupled with RNA sequencing (MAPS) and quantitative differential proteomics, sodA mRNA was identified as a primary target of RsaC sRNA. SodA is a Mn-dependent superoxide dismutase involved in oxidative stress response. Remarkably, rsaC gene is co-transcribed with the major manganese ABC transporter MntABC and, consequently, RsaC is mainly produced in response to Mn starvation. This 3'UTR-derived sRNA is released from mntABC-RsaC precursor after cleavage by RNase III. The mature and stable form of RsaC inhibits the synthesis of the Mn-containing enzyme SodA synthesis and favors the oxidative stress response mediated by SodM, an alternative SOD enzyme using either Mn or Fe as co-factor. In addition, other putative targets of RsaC are involved in oxidative stress (ROS and NOS) and metal homeostasis (Fe and Zn). Consequently, RsaC may balance two interconnected defensive responses, i.e. oxidative stress and metal-dependent nutritional immunity.
| S-EPMC6765141 | biostudies-literature
Project description:Manganese (Mn) is an essential micronutrient critical for the pathogenesis of Staphylococcus aureus, a significant cause of human morbidity and mortality. Paradoxically, excess Mn is toxic, therefore maintaining intracellular Mn homeostasis is required for survival. To identify gene candidates that contribute to manganese detoxification, we compared the transcriptional response of S. aureus cells exposed to 1 mM MnCl2 and those that were untreated.
2019-01-01 | GSE124285 | GEO
Project description:For Staphylococcus aureus it was shown previously that aminocoumarinecoumarin antibiotics such as novobiocin lead to immediate down-regulation of recA expression and thereby inhibition of the SOS response, the mutation frequency and the recombination capacity. Aminocoumarinecoumarin function by inhibition of the ATPase activity of the gyrase subunit B. Here we analysed the global impact of the DNA relaxing agent novobiocin on gene expression in S. aureus. By use of a novobiocin resistant mutant, it became evident that the change in recA expression is due to gyrase inhibition. Microarray analysis and Northern blot hybridization revealed that the expression of a distinct set of genes is increased (e.g. recF-gyrB-gyrA, rib operon and ure operon …)), or decreased (e.g. arlRS, recA, lukA, hlgC, fnbA) by novobiocin. The two-component ArlRS system was previously found to decrease the supercoiling level in S. aureus. Thus, down-regulation of arlRS might in part compensate for the relaxing effect of novobiocin. Novobiocin resulted in down-regulation of several of arlRS repressed target genes in an arl mutant. Global analysis and gene mapping of supercoiling sensitive genes did not give indications that they are clustered in the genome. Promoter fusion assays confirmed that responsiveness of a given gene is intrinsic to the promoter region but independent of the chromosomal location. The results indicate that molecular property of the spacers of a given promoter dictatesa given promoter rather than chromosomal topology dictates the responsiveness towards changes in supercoiling rather than chromosomal topology.
2014-09-08 | GSE50157 | GEO
Project description:For Staphylococcus aureus it was shown previously that aminocoumarinecoumarin antibiotics such as novobiocin lead to immediate down-regulation of recA expression and thereby inhibition of the SOS response, the mutation frequency and the recombination capacity. Aminocoumarinecoumarin function by inhibition of the ATPase activity of the gyrase subunit B. Here we analysed the global impact of the DNA relaxing agent novobiocin on gene expression in S. aureus. By use of a novobiocin resistant mutant, it became evident that the change in recA expression is due to gyrase inhibition. Microarray analysis and Northern blot hybridization revealed that the expression of a distinct set of genes is increased (e.g. recF-gyrB-gyrA, rib operon and ure operon M-bM-^@M-&)), or decreased (e.g. arlRS, recA, lukA, hlgC, fnbA) by novobiocin. The two-component ArlRS system was previously found to decrease the supercoiling level in S. aureus. Thus, down-regulation of arlRS might in part compensate for the relaxing effect of novobiocin. Novobiocin resulted in down-regulation of several of arlRS repressed target genes in an arl mutant. Global analysis and gene mapping of supercoiling sensitive genes did not give indications that they are clustered in the genome. Promoter fusion assays confirmed that responsiveness of a given gene is intrinsic to the promoter region but independent of the chromosomal location. The results indicate that molecular property of the spacers of a given promoter dictatesa given promoter rather than chromosomal topology dictates the responsiveness towards changes in supercoiling rather than chromosomal topology. We analyzed S. aureus global gene expression changes to the treatment of novobiocin
2014-09-08 | E-GEOD-50157 | biostudies-arrayexpress
Project description:The human opportunistic pathogen Staphylococcus aureus has developed multiple strategies to adapt to various environments, to fight and escape the immune system, to spread and persist in host tissues. It is responsible for numerous diseases ranging from benign skin infections to more serious such as endocarditis or septicemia. The pathogenicity is due to the production of a multitude of virulence factors, whose synthesis is finely regulated by a combination of regulatory proteins and small non-coding RNAs (sRNAs). Our study reveals an unexpected function of an atypical sRNA, RsaC, which is at the heart of networks controlling defence responses to oxidative stress, manganese import and nutrition immunity. This work highlights a novel mechanism required for S. aureus to survive into its host.
2019-11-11 | PXD013225 | Pride
Project description:Staphylococcus aureus pathogenicity is mainly due to the production of a number of secreted and cell surface-associated proteins under the regulation of the agr gene. A region of the agr gene was used to subgroup S. aureus strains according to restriction fragment length polymorphisms. Additionally, strains were subtyped according to the coagulase gene in order to strengthen discriminatory power. Virulence capabilities of agr genotype subgroups were evaluated using an in vitro neutrophil bactericidal assay, which showed that prevalent genotypes were significantly better at evading this primary host defense. Multiplex PCR was then used to detect enterotoxin genes among the genotype subgroups in order to determine possible virulence candidates that enable strains to combat neutrophil killing. The prevalent genotype strains were found to possess higher production capabilities for enterotoxin A than did low-prevalence strains. The significance of enterotoxin A production capabilities in affecting pathogenicity of S. aureus strains was evaluated and found to have a profound effect on neutrophil killing abilities. The use of a large epidemiological database as a tool for subgrouping strains with varying degrees of pathogenicity has allowed the identification of relevant and previously undefined virulence factors that affect a pathogen's capability to overcome host immune defenses.
| S-EPMC97853 | biostudies-literature
Project description:Staphylococcus aureus thymidine-dependent small-colony variants (TD-SCVs) are frequently isolated from patients with chronic S. aureus infections after long-term treatment with trimethoprim-sulfamethoxazole (TMP-SMX). In TD-SCVs, mutations of thymidylate synthase (thyA, TS), essential for DNA synthesis, occur. However, it has never been shown, that TMP-SMX is responsible for the induction and selection of TD-SCVs. Short-term exposure of TMP-SMX induced the TD-SCV phenotype morphologically as shown in transmission electron-microscopy and on the transcriptional level by qRT-PCR in wild-type S. aureus, while selection of TD-SCVs with thyA mutations occurred only rarely after long-term exposure. In reversion experiments with clinical TD-SCVs, all revertants revealed compensating mutations at the initially identified mutation site. Whole DNA microarray analysis of a thyA deletion mutant (∆thyA), which exhibited the typical TD-SCV phenotype, identified tremendous alterations compared to the wild-type. Important virulence regulators such as agr, arlRS, sarA and major virulence determinants including hla, hlb, sspA, sspB and geh were down-regulated, while genes associated with the colonization capacity like fnbA, fnbB, spa, clfB, sdrC and sdrD were up-regulated. The expression of genes involved in pyrimidine and purine metabolism as well as in nucleotide interconversion changed significantly. The ∆thyA-mutant was attenuated in virulence in both, a Caenorhabditis elegans killing model and an acute murine pneumonia model. Furthermore, competition experiments in vitro and in vivo (using a chronic pneumonia mouse model) revealed a survival and growth advantage of the ∆thyA-mutant under low thymidine conditions and TMP-SMX exposure. In conclusion, our results clearly show for the first time that TMP-SMX induces the TD-SCV phenotype after short-term exposure in S. aureus and that long-term exposure selects thyA mutations providing an advantage for TD-SCVs under specified conditions. Thus, our results help to understand the dynamic processes of induction and selection of S. aureus TD-SCVs during TMP-SMX exposure.
2013-05-29 | GSE47406 | GEO