Project description:Polymyxin B is considered as a last-resort antibiotic for multidrug-resistant or extensively drug-resistant gram-negative bacterial infections. Addressing Salmonella resistance to polymyxin B is crucial for global public health. In this study, transcriptomic detection and analysis were used to clarify the mechanisms by which CpxA-deleted S.typhimurium is involved in resistance to polymyxin B stress, which may be related to processes such as increased assembly of bacterial flagella.
Project description:Bacterial filamentation is one of the most important bacterial SOS responses to antibiotic drugs and contributes to the development of antimicrobial resistance. Understanding the mechanism of the bacterial SOS response is crucial to control the development of antibiotic-resistant bacteria. We uncover the molecular changes of SOS-associated bacterial filamentation. Bacterial proteins that correlate with bacterial SOS responses and facilitate to bacterial antimicrobial resistance are studied.
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.
Project description:Efflux pumps of the resistance-nodulation-division (RND) superfamily, particularly the AcrAB-TolC and MexAB-OprM, besides mediating intrinsic and acquired resistance, also intervene in bacterial pathogenicity. Inhibitors of such pumps could restore activities of antibiotics and curb bacterial virulence. Here, we identify pyrrole-based compounds that boost antibiotic activity in Escherichia coli and Pseudomonas aeruginosa by inhibiting their archetype RND transporters. The discovered efflux pump inhibitors (EPIs) inhibit the efflux of fluorescent probes, attenuate persister formation, and diminish resistant mutant development. Molecular docking and biophysical studies revealed that the EPIs bind to AcrB. EPIs also possess an anti-pathogenic potential and attenuate P. aeruginosa virulence in vivo. The excellent efficacy of the EPI-antibiotic combination was evidenced in animal lung infection and sepsis protection models. These findings indicate that EPIs discovered herein with no off-target effects and negligible toxicity are potential antibiotic adjuvants to address life-threatening bacterial infections.
Project description:Prediction of antimicrobial potential using a dataset of 29537 compounds screened against the antibiotic resistant pathogen Burkholderia cenocepacia. The model uses the Chemprop Direct Message Passing Neural Network (D-MPNN) and has an AUC score of 0.823 for the test set. It has been used to virtually screen the FDA approved drugs as well as a collection of natural product list (>200k compounds) with hit rates of 26% and 12% respectively.
Model Type: Predictive machine learning model.
Model Relevance: Probability that a compound inhibits bacterial pathogens with a focus on ESKAPE.
Model Encoded by: Sarima Chiorlu (Ersilia)
Metadata Submitted in BioModels by: Zainab Ashimiyu-Abdusalam
Implementation of this model code by Ersilia is available here:
https://github.com/ersilia-os/eos5xng
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.
This model is hosted on BioModels Database
and identified by: MODEL1208300000
.
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:Antibiotic resistance is increasingly becoming a serious challenge to public health. The regulation of metabolism by post-translational modifications (PTMs) has been widely studied; however, the comprehensive mechanism underlying the regulation of acetylation in bacterial resistance against antibiotics is unknown. Herein, with Escherichia coli as the model, we performed quantitative analysis of the acetylated proteome of wild-type sensitive strain (WT) and ampicillin- (Re-Amp), kanamycin- (Re-Kan), and polymyxin B-resistant (Re-Pol) strains. Based on bioinformatics analysis combined with biochemical validations, we found that a common regulatory mechanism exists between the different resistant strains. Acetylation negatively regulates bacterial metabolism to maintain antibiotic resistance, but positively regulates bacterial motility. Further analyses revealed that key enzymes in various metabolic pathways were differentially acetylated. Particularly, pyruvate kinase (PykF), a key glycolytic enzyme regulating bacterial metabolism, and its acetylated form were highly expressed in the three resistant types and were identified as reversibly acetylated by the deacetylase CobB and the acetyl-transferase PatZ, and also could be acetylated by non-enzyme AcP in vitro. Further, the deacetylation of Lys413 of PykF increased the enzyme activity by changing the conformation of ATP binding site of PykF, resulting in an increase in energy production, which in turn increased the sensitivity of drug-resistant strains to antibiotics. This study provides novel insights for understanding bacterial resistance and lays the foundation for future research on regulation of acetylation in antibiotic-resistant strains.
Project description:Many bacteria are often resistant to antibiotic treatment and drugs because, even if these drugs are effective, bacteria can slow down their growth rate and thus attenuate the effectiveness of the drug. A similar growth-rate control is detected in pathogenic bacteria that infect and persist inside their hosts. The bacterial growth rate within host cells can be regulated by multiple signaling pathways, most of which are still unknown. A toxin-antitoxin (TA) system is one of the candidates for controlling bacterial growth because the TA system could slow down growth by expressing a toxin component. The toxin protein can be neutralized by the antitoxin component, serving as a non-heritable phenotypic switch for growth rate. In this study, we investigated a type II toxin-antitoxin system from the intracellular bacterial pathogen Salmonella enterica serovar Typhimurium. We characterized residues required for toxin’s activity and a potential mechanism of the toxin by searching for its target via bacterial two-hybrid screening. Understanding the underlying mechanism of toxin-mediated persister formation and growth rate control within host cells will provide a new alternative to treat antibiotic resistant bacteria or intracellular bacteria surviving within host cells.
Project description:Many bacteria are often resistant to antibiotic treatment and drugs because, even if these drugs are effective, bacteria can slow down their growth rate and thus attenuate the effectiveness of the drug. A similar growth-rate control is detected in pathogenic bacteria that infect and persist inside their hosts. The bacterial growth rate within host cells can be regulated by multiple signaling pathways, most of which are still unknown. A toxin-antitoxin (TA) system is one of the candidates for controlling bacterial growth because the TA system could slow down growth by expressing a toxin component. The toxin protein can be neutralized by the antitoxin component, serving as a non-heritable phenotypic switch for growth rate. In this study, we investigated a type II toxin-antitoxin system from the intracellular bacterial pathogen Salmonella enterica serovar Typhimurium. We characterized residues required for toxin’s activity and a potential mechanism of the toxin by searching for its target via bacterial two-hybrid screening. Understanding the underlying mechanism of toxin-mediated persister formation and growth rate control within host cells will provide a new alternative to treat antibiotic resistant bacteria or intracellular bacteria surviving within host cells.
Project description:According to our study, Chrysanthemum lavandulifolum extract showed excellent antibiotic effects on Escherichia coli O157:H7. A notable point is that the antibiotic efficacy of the herb extract is on the all three proven targets for main antibiotic drugs that are bacterial cell wall biosynthesis, bacterial protein synthesis and bacterial DNA replication and repair. This multi-target efficacy of the herbal antibiotics may be used as more effective and safe drugs that substitute existing antibiotics.