Project description:Heinemann2005 - Genome-scale reconstruction
of Staphylococcus aureus (iMH551)
This model is described in the article:
In silico genome-scale
reconstruction and validation of the Staphylococcus aureus
metabolic network.
Heinemann M, Kümmel A,
Ruinatscha R, Panke S.
Biotechnol. Bioeng. 2005 Dec; 92(7):
850-864
Abstract:
A genome-scale metabolic model of the Gram-positive,
facultative anaerobic opportunistic pathogen Staphylococcus
aureus N315 was constructed based on current genomic data,
literature, and physiological information. The model comprises
774 metabolic processes representing approximately 23% of all
protein-coding regions. The model was extensively validated
against experimental observations and it correctly predicted
main physiological properties of the wild-type strain, such as
aerobic and anaerobic respiration and fermentation. Due to the
frequent involvement of S. aureus in hospital-acquired
bacterial infections combined with its increasing antibiotic
resistance, we also investigated the clinically relevant
phenotype of small colony variants and found that the model
predictions agreed with recent findings of proteome analyses.
This indicates that the model is useful in assisting future
experiments to elucidate the interrelationship of bacterial
metabolism and resistance. To help directing future studies for
novel chemotherapeutic targets, we conducted a large-scale in
silico gene deletion study that identified 158 essential
intracellular reactions. A more detailed analysis showed that
the biosynthesis of glycans and lipids is rather rigid with
respect to circumventing gene deletions, which should make
these areas particularly interesting for antibiotic
development. The combination of this stoichiometric model with
transcriptomic and proteomic data should allow a new quality in
the analysis of clinically relevant organisms and a more
rationalized system-level search for novel drug targets.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180072.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:The rise of antibiotic resistance in many bacterial pathogens has been driven by the spread of a few successful strains, suggesting that some bacteria are genetically pre-disposed to evolving resistance. We tested this hypothesis by challenging a diverse set of 222 strains of Staphylococcus aureus with the antibiotic ciprofloxacin in a large-scale evolution experiment. Surprisingly, we found that a single efflux pump, norA, causes widespread variation in evolvability across the diversity of S. aureus. In most lineages of S. aureus, elevated norA expression potentiated evolution by increasing the fitness benefit provided by resistance mutations in DNA topoisomerase under ciprofloxacin treatment. Amplification of norA provided a further mechanism of rapid evolution, but this was restricted to strains from CC398. Crucially, chemically inhibiting NorA effectively prevented the evolution of resistance across the diversity of S. aureus. Our study shows that the underlying genetic diversity of pathogenic bacteria plays a key role in shaping resistance evolution. Understanding this link makes it possible to predict which strains are likely to evolve resistance and to optimize inhibitor use to prevent this outcome.
Project description:Becker2005 - Genome-scale metabolic network
of Staphylococcus aureus (iSB619)
This model is described in the article:
Genome-scale reconstruction
of the metabolic network in Staphylococcus aureus N315: an
initial draft to the two-dimensional annotation.
Becker SA, Palsson BØ.
BMC Microbiol. 2005; 5: 8
Abstract:
BACKGROUND: Several strains of bacteria have sequenced and
annotated genomes, which have been used in conjunction with
biochemical and physiological data to reconstruct genome-scale
metabolic networks. Such reconstruction amounts to a
two-dimensional annotation of the genome. These networks have
been analyzed with a constraint-based formalism and a variety
of biologically meaningful results have emerged. Staphylococcus
aureus is a pathogenic bacterium that has evolved resistance to
many antibiotics, representing a significant health care
concern. We present the first manually curated elementally and
charge balanced genome-scale reconstruction and model of S.
aureus' metabolic networks and compute some of its properties.
RESULTS: We reconstructed a genome-scale metabolic network of
S. aureus strain N315. This reconstruction, termed iSB619,
consists of 619 genes that catalyze 640 metabolic reactions.
For 91% of the reactions, open reading frames are explicitly
linked to proteins and to the reaction. All but three of the
metabolic reactions are both charge and elementally balanced.
The reaction list is the most complete to date for this
pathogen. When the capabilities of the reconstructed network
were analyzed in the context of maximal growth, we formed
hypotheses regarding growth requirements, the efficiency of
growth on different carbon sources, and potential drug targets.
These hypotheses can be tested experimentally and the data
gathered can be used to improve subsequent versions of the
reconstruction. CONCLUSION: iSB619 represents comprehensive
biochemically and genetically structured information about the
metabolism of S. aureus to date. The reconstructed metabolic
network can be used to predict cellular phenotypes and thus
advance our understanding of a troublesome pathogen.
This model is hosted on
BioModels Database
and identified by:
MODEL1507180070.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:To study the effect of Radix Paeoniae Rubra decoction on tolerance of Staphylococcus aureus.The effect of Radix Paeoniae Rubra on the resistance of Staphylococcus aureus to oxacillin sodium was studied by millipore dilution method in this experiment.At the same time ,conducted on transcriptome analysis of Staphylococcus aureus related genes in Radix Paeoniae Rubra.And to detect the expression level of related genes of Staphylococcus aureus under the action of Radix Paeoniae Rubra by PCR technology.The tolerance of Staphylococcus aureus was decreased obviously when the concentration of Radix Paeoniae Rubra decoction was above 1mg/ml.The effect of Radix Paeoniae Rubra decoction on the expression of tolerance genes femB,pvL and gluM when the concentration of Radix Paeoniae Rubra decoction was above 4mg/ml.When rhe concentration of Radix Paeoniae Rubra is more than 1mg/ml,it can effectively reduce the resistance of Staphylococcus aureus to oxacillin sodium.The reason may be due to the effect of Radix Paeoniae Rubra on the resistance gene of Staphylococcus aureus.
Project description:Bacterial persister cells are phenotypic variants that exhibit a transient non-growing state and antibiotic tolerance. Here we provide in vitro evidence of Staphylococcus aureus persisters within infected host cells. We show that the bacteria surviving antibiotic treatment within host cells are persisters, displaying biphasic killing and reaching a uniformly non-responsive, non-dividing state when followed at the single-cell level. This phenotype is stable but reversible upon antibiotic removal. Intracellular S. aureus persisters remain metabolically active, but display an altered transcriptomic profile consistent with activation of stress responses, including the stringent response as well as cell-wall stress, SOS and heat-shock responses. These changes are associated with multidrug tolerance after exposure to a single antibiotic. We hypothesize that intracellular S. aureus persisters may constitute a reservoir for relapsing infection, and could contribute to therapeutic failures.