Aminoglycosides induce a bacterial senescent state that increases antibiotic tolerance in treatment-naïve cells
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ABSTRACT:
ORGANISM(S): Escherichia coli BW25113
PROVIDER: GSE184377 | GEO | 2022/12/31
REPOSITORIES: GEO
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Project description:In a given bacterial population, antibiotic treatment kills a large portion of the population, while a small, tolerant subpopulation survives. Tolerant cells disrupt the efficacy of antibiotic treatment and increase the likelihood that a population gains antibiotic resistance. Antibiotic tolerance is different from resistance because tolerant cells cannot grow and replicate in the presence of the antibiotic, but when the antibiotic is removed, they begin to propagate. When a population becomes resistant, the antibiotic becomes ineffective, which is a major health concern. Since antibiotic tolerance often leads to antibiotic resistance, we have taken a systems biology approach to examine how regulatory networks respond to antibiotic stress so that cells can survive and recover after antibiotic treatment. We have compared gene expression with and without ampicillin in E. coli.
2020-12-04 | GSE156896 | GEO
Project description:Tan2012 - Antibiotic Treatment, Inoculum Effect
The efficacy of many antibiotics decreases with increasing bacterial density, a phenomenon called the ‘inoculum effect’ (IE). This study reveals that, for ribosome-targeting antibiotics, IE is due to bistable inhibition of bacterial growth, which reduces the efficacy of certain treatment frequencies.
This model is described in the article:
The inoculum effect and band-pass bacterial response to periodic antibiotic treatment.
Tan C, Phillip Smith R, Srimani JK, Riccione KA, Prasada S, Kuehn M, You L.
Mol Syst Biol. 2012 Oct 9; 8:617
Abstract:
The inoculum effect (IE) refers to the decreasing efficacy of an antibiotic with increasing bacterial density. It represents a unique strategy of antibiotic tolerance and it can complicate design of effective antibiotic treatment of bacterial infections. To gain insight into this phenomenon, we have analyzed responses of a lab strain of Escherichia coli to antibiotics that target the ribosome. We show that the IE can be explained by bistable inhibition of bacterial growth. A critical requirement for this bistability is sufficiently fast degradation of ribosomes, which can result from antibiotic-induced heat-shock response. Furthermore, antibiotics that elicit the IE can lead to 'band-pass' response of bacterial growth to periodic antibiotic treatment: the treatment efficacy drastically diminishes at intermediate frequencies of treatment. Our proposed mechanism for the IE may be generally applicable to other bacterial species treated with antibiotics targeting the ribosomes.
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2012-11-01 | BIOMD0000000425 | BioModels
Project description:For this study, we created three highly representational different sized genomic libraries of P. aeruginosa PAO1 within the vector pBTB-1. Vector pBTB-1 is a low copy number broad host range plasmid containing a Ã-lactamase resistance marker, a pBAD promoter upstream of the cloning site, as well as transcriptional terminators flanking the cloning site to aid in insert stability. These libraries were transformed into the recombination-deficient P. aeruginosa PAO1 mutant, PAO2003, pooled, and parallel selections performed to identify via traditional sequencing or SCALEs the genomic regions capable of conferring increased tolerance to amikacin, gentamicin, or tobramycin. These antibiotics are all structurally related but have differing substitution patterns on their aminoglycoside backbones. These differences in structure and substitution patterns impact the activity of each antibiotic. We chose to study three different aminoglycosides in attempts to identify genomic regions capable of conferring resistance to not only a specific aminoglycoside, but also to the more general class of aminoglycosides.
2009-12-19 | E-MEXP-2396 | biostudies-arrayexpress
Project description:Several groups have shown that through evolution experiments, tolerance evolved rapidly under cyclic antibiotic treatment which then promote the emergence of resistance. In other words, intermittent antibiotic exposure will “train” the bacteria to become tolerant to the drug, and then boost the chances for them to become fully resistant. This evolutionary trajectory of evolving tolerance and resistance not only occurs in vitro, but also in clinical patients with MRSA blood infections. Despite the fact that repetitive antibiotic treatment will lead to tolerance and resistance development in bacterial populations, the difference on the evolutionary path between those treated with a single drug and drug combination remains unaddressed. In this study, we monitored the development of tolerance in MRSA by treating them with either daptomycin alone for 2 weeks (Scheme 1), or daptomycin combined with rifampin for two weeks (Scheme 2), in a cyclic manner. In addition, we also investigate another scenario where we treat MRSA cells with daptomycin alone for one week, and subsequently treat them with daptomycin and rifampin combination in the second week (Scheme 3). At the end of the evolution experiment, we observed that the population from Scheme 1 developed tolerance towards daptomycin, the population from Scheme 2 developed both tolerance and resistance towards daptomycin, while the population from Scheme 3 developed tolerance after a week of treatment, but then the tolerance phenotype diminished at the end of the second week due to the drug combination treatment. We subjected them to whole genome sequencing and identified single point mutations that are responsible for the observed phenotype. Through proteomics, we compared the proteome profile of the population evolved from scheme 1 (S1D14), scheme 2 (S2D14) and scheme 3 (S3D14), and we observed that these three populations employ distinct mechanisms to survive antibiotic treatment, suggesting that the treatment strategy for these populations should be tailored depending on the treatment conditions.
2021-07-27 | PXD021667 | Pride
Project description:Enterobacter cloacae is a Gram-negative nosocomial pathogen of the ESKAPE priority group with increasing multi-drug resistance via the acquisition of resistance plasmids. However, E. cloacae can also display phenotypic antimicrobial resistance, such as heteroresistance or persistence. Here we report that E. cloacae ATCC 13047 and six strains isolated from patients with blood infections display heteroresistance or persistence to aminoglycosides. E. cloacae heteroresistance is transient, accompanied with formation of "petite" colonies and increased MIC against gentamicin and other aminoglycosides used in the clinic, but not other antibiotic classes. To explore the underlying mechanisms, we performed RNA sequencing of heteroresistant bacteria, which revealed global gene-expression changes and a signature of the CpxRA cell envelope stress response. Deletion of the cpxRA two-component system abrogated aminoglycoside heteroresistance and petite colony formation, pointing to its indispensable role in phenotypic resistance. The introduction of a constitutively active allele of cpxA led to high aminoglycoside MICs, consistent with cell envelope stress driving these behaviours in E. cloacae. Cell envelope stress can be caused by environmental cues, including heavy metals. Indeed, bacterial exposure to copper increased gentamicin MIC in the wild type, but not the ΔcpxRA mutant. Moreover, copper exposure also elevated the gentamicin MICs of bloodstream isolates, suggesting that CpxRA- and copper-dependent aminoglycoside resistance is broadly conserved in E. cloacae strains. Altogether, we establish that E. cloacae relies on transcriptional reprogramming via the envelope stress response pathway for transient resistance to a major class of frontline antibiotic.
2023-10-18 | GSE236124 | GEO
Project description:We investigate the differences in total gene expression between P.aeruginosa PAO1 (wild-type) and mexZ isogenic mutant. Inactivation of mexZ is known to lead to the overexpress of mexX and mexY genes and being involved in intrinsic resistance antibiotic, in particular to aminoglycosides. Cells were grown in a rich medium without any selective pressure (shaking at 37C) and cells were harvested during mid-log phase at OD600 0.5.
2018-08-21 | E-MTAB-5820 | biostudies-arrayexpress
Project description:Drug resistance and tolerance eliminate the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. To uncover antibiotic tolerance mechanisms in biofilms, we applied stable isotope labeling with amino acids (SILAC) proteomics to selectively label and compare proteomes of sensitive and tolerant subpopulations of biofilms formed by Pseudomonas aeruginosa towards colistin, a 'last-resort' antibiotic against multidrug-resistant Gram-negative pathogens. Migration was essential in forming colistin-tolerant biofilm subpopulations, as colistin-tolerant cell-aggregates migrated with type IV pili, onto the top of killed biofilm. The colistin-tolerant cell-aggregates employed quorum sensing (QS) to initiate the formation of fresh colistin-tolerant subpopulations, highlighting multicellular behavior in antibiotic tolerance development. Erythromycin treatment which inhibits motility and QS, boosted biofilm eradication by colistin. This novel ‘-omics’ strategy to study antibiotic tolerant cells provides key insights for designing novel treatments against infections unsuppressed by conventional antimicrobials.
2016-02-16 | PXD002369 | Pride
Project description:Pseudomonas aeruginosa harbors sophisticated transcription factor (TF) networks to coordinately regulate cellular metabolic states for rapidly adapting to changing environments. The superior capacity in fine-tuning the metabolic states enables its success in tolerance to antibiotics and evading host immune defenses. However, the linkage among transcriptional regulation, metabolic states, and antibiotic tolerance in P. aeruginosa remains largely unclear. By screening the P. aeruginosa TF mutant library constructed by CRISPR/Cas12k-guided transposase, we identify that rccR (PA5438) is a major genetic determinant in aminoglycoside antibiotic tolerance, the deletion of which substantially enhances bacterial tolerance. We further reveal the inhibitory roles of RccR in pyruvate metabolism (aceE/F) and glyoxylate shunt pathway (aceA and glcB), and overexpression of aceA or glcB enhances bacterial tolerance. Moreover, we identify that 2-keto-3-deoxy-6-phosphogluconate (KDPG) is a signal molecule that directly binds to RccR. Structural analysis of the RccR/KDPG complex reveals the detailed interactions. Substitution of the key residues R152, K270, or R277 with alanine abolishes KDPG sensing by RccR and impairs bacterial growth with glycerol or glucose as the sole carbon source. Collectively, our study unveils the connection between aminoglycoside antibiotic tolerance and RccR-mediated central carbon metabolism regulation in P. aeruginosa, and elucidates the KDPG sensing mechanism by RccR.
2023-07-20 | GSE237535 | GEO
Project description:Bacterial evolution of antibiotic resistance frequently has deleterious side effects on microbial growth, virulence, and susceptibility to other antimicrobial agents. However, it is unclear how these trade-offs could be utilized for manipulating antibiotic resistance in the clinic, not least because the underlying molecular mechanisms are poorly understood. Using laboratory evolution, we demonstrate that clinically relevant resistance mutations in Escherichia coli constitutively rewire a large fraction of the transcriptome in a repeatable and stereotypic manner. Strikingly, lineages adapted to functionally distinct antibiotics and having no resistance mutations in common show a wide range of parallel gene expression changes that alter oxidative stress response, iron homeostasis, and the composition of the bacterial outer membrane and cell surface. These common physiological alterations are associated with changes in cell morphology and enhanced sensitivity to antimicrobial peptides. Finally, the constitutive transcriptomic changes induced by resistance mutations are largely distinct from those induced by antibiotic stresses in the wild-type. This indicates a limited role for genetic assimilation of the induced antibiotic stress response during resistance evolution. Our work suggests that diverse resistance mutations converge on similar global transcriptomic states that shape genetic susceptibility to antimicrobial compounds.
2023-01-26 | GSE223493 | GEO
Project description:Kaiser2014 - Salmonella persistence after ciprofloxacin treatment
The model describes the bacterial tolerance to antibiotics. Using a mouse model for Salmonella diarrhea, the authors have found that bacterial persistence occurs in the presence of the antibiotic ciprofloxacin because Salmonella can exist in two different states. One, the fast-growing population that spreads in the host's tissues and the other, slow-growing "persister" population that hide out inside dendritic cells of the host's immune system and cannot be attacked by the antibiotics. However, this can be killed by adding agents that directly stimulate the host's immune defense.
This model is described in the article:
Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.
Kaiser P, Regoes RR, Dolowschiak T, Wotzka SY, Lengefeld J, Slack E, Grant AJ, Ackermann M, Hardt WD.
PLoS Biol. 2014 Feb 18;12(2):e1001793.
Abstract:
In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN), the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.
This model is hosted on BioModels Database and identified
by: MODEL1312170001.
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.
2014-03-25 | BIOMD0000000527 | BioModels