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:<p>The study of antimicrobial resistance (AMR) in infectious diarrhea has generally been limited to cultivation, antimicrobial susceptibility testing and targeted PCR assays. When individual strains of significance are identified, whole genome shotgun (WGS) sequencing of important clones and clades is performed. Genes that encode resistance to antibiotics have been detected in environmental, insect, human and animal metagenomes and are known as "resistomes". While metagenomic datasets have been mined to characterize the healthy human gut resistome in the Human Microbiome Project and MetaHIT and in a Yanomani Amerindian cohort, directed metagenomic sequencing has not been used to examine the epidemiology of AMR. Especially in developing countries where sanitation is poor, diarrhea and enteric pathogens likely serve to disseminate antibiotic resistance elements of clinical significance. Unregulated use of antibiotics further exacerbates the problem by selection for acquisition of resistance. This is exemplified by recent reports of multiple antibiotic resistance in Shigella strains in India, in Escherichia coli in India and Pakistan, and in nontyphoidal Salmonella (NTS) in South-East Asia. We propose to use deep metagenomic sequencing and genome level assembly to study the epidemiology of AMR in stools of children suffering from diarrhea. Here the epidemiology component will be surveillance and analysis of the microbial composition (to the bacterial species/strain level where possible) and its constituent antimicrobial resistance genetic elements (such as plasmids, integrons, transposons and other mobile genetic elements, or MGEs) in samples from a cohort where diarrhea is prevalent and antibiotic exposure is endemic. The goal will be to assess whether consortia of specific mobile antimicrobial resistance elements associate with species/strains and whether their presence is enhanced or amplified in diarrheal microbiomes and in the presence of antibiotic exposure. This work could potentially identify clonal complexes of organisms and MGEs with enhanced resistance and the potential to transfer this resistance to other enteric pathogens.</p> <p>We have performed WGS, metagenomic assembly and gene/protein mapping to examine and characterize the types of AMR genes and transfer elements (transposons, integrons, bacteriophage, plasmids) and their distribution in bacterial species and strains assembled from DNA isolated from diarrheal and non-diarrheal stools. The samples were acquired from a cohort of pediatric patients and controls from Colombia, South America where antibiotic use is prevalent. As a control, the distribution and abundance of AMR genes can be compared to published studies where resistome gene lists from healthy cohort sequences were compiled. Our approach is more epidemiologic in nature, as we plan to identify and catalogue antimicrobial elements on MGEs capable of spread through a local population and further we will, where possible, link mobile antimicrobial resistance elements with specific strains within the population.</p>
| phs001260 | dbGaP
Project description:WGS of antibiotic resistant bacterial strains
Project description:hvKP ATCC43816 and its lytic phage H5 were employed as a phage-antibiotic combination model. Based on the comprehensive characterization of phages, including cryo-electron microscopy, we evaluated the synergic effect of H5 on bacterial killing in vitro when combined with multiple antibiotics, and analyzed the advantages of phage-antibiotic combinations from an evolutionary perspective and proposes a novel PAS mechanism by using ceftazidime as an example.
Project description:Protein post-translational modifications (PTMs) play crucial roles in various biological processes across prokaryotes and eukaryotes. Lysine acetylation (Kac), which is observed in different bacteria species and is known to be a dynamic and reversible PTM involved in numerous physiological functions. However, limited research has been conducted to explore the connection between Kac and bacterial antibiotic resistance. In this investigation, we employed advanced 4D label-free quantitative proteomics technology to examine the differential expression of Kac-modified proteins in Staphylococcus aureus strains: one susceptible to erythromycin (Ery-S) and another induced to be resistant (Ery-R). Our systematic analysis identified a total of 1808 acetylated proteins with 6791 specific Kac sites. Notably, we quantified 1907 of these sites across 483 proteins. A total of 548 Kac sites were affected by erythromycin pressure on 316 acetylated proteins. Functional analyses uncovered a notable presence of differentially acetylated proteins (DAPs) within pathways associated with ribosome assembly, glycolysis, and lysine biosynthesis. Moreover, our findings indicate a significant acetylation of ribosomal proteins in antibiotic-resistant strains, implying a potential regulatory role of this modification in translation processes. Further investigations using polysome profiling experiments revealed that Kac modification of ribosomal and ribosome-associated proteins can maintain translation in response to antibiotic stress. Our data provides support for the link between protein lysine acetylation and bacterial antibiotic resistance, highlighting the potential involvement of ribosome translation. These findings collectively unveil a novel mechanism that enhances our understanding of bacterial antibiotic resistance and offer valuable insights for the development of antibiotic treatment strategies.
Project description:Antimicrobial resistance is a global health threat, and alternative therapeutic interventions to replace failing antibiotics are urgently needed. Vaccines are effective tools to combat bacterial infection and mitigate multi-drug resistance, however, the selection of bacterial antigens as vaccine candidates remains challenging. Here we use immunopeptidomics to mine for CD4 T-cell vaccine targets in methicillin-resistant Staphylococcus aureus - a clinically significant, antibiotic-resistant bacterium that is susceptible to T cell meditated control. We identified a novel, highly conserved, immunodominant CD4 T cell epitope in S. aureus that is derived from the core DNA binding protein Hu (Hup). This epitope is shared across a range of clinically relevant bacteria and cross-species reactive Hup specific CD4 T cells are found in both mice and humans. Immunisation with the Hup epitope resulted in the development of broadly protective CD4 T cell immunity capable of limiting disease severity following infection with different bacterial species, including S. aureus and Streptococcus pneumoniae. A vaccine incorporating antigenic targets derived from conserved core genes that are shared across bacterial species, can confer broad spectrum protection against a range of clinically significant bacteria, including antibiotic-resistant strains.
Project description:Staphylococcus aureus is a major pathogen of healthcare settings with a high rate of morbidity and mortality. S. aureus has also emerged as a serious threat in healthy individuals in the community. Increasingly, antibiotic resistant S. aureus strains, particularly methicillin resistant S. aureus (MRSA), are causing these community-acquired infections (CA-MRSA). Because of the rising incidence of antibiotic resistance, including resistance to “last resort” antibiotics, development of prophylactic vaccines for S. aureus is considered a high priority. A complete, accurate characterization of the transcriptome of the host during different types of infection would expedite S. aureus vaccine development by identifying antigens that would be optimal vaccine targets. RNA-seq (deep-sequencing of cDNA) provides an unbiased method to comprehensively and systematically define the transcriptome (the complete set of transcribed regions in a genome) of an organism in a manner that is significantly more sensitive than microarray hybridization approaches. We propose a comprehensive characterization of the host transcriptome in two different murine models of infection (systemic infection and skin and soft tissue infection (SSTI)). We believe that this research will provide insight into potential vaccine targets that are expressed at high levels in both types of infection. We also wish to determine what mouse genes are up- or down-regulated during the course of these infections in order to better characterize the host-pathogen interaction. This description of the in vivo transcriptome will give novel insight into how the host senses and responds to infection with S. aureus in different infection types, and how the host tissue responds to bacterial invasion.
Project description:Staphylococcus aureus is a high-priority pathogen causing severe infections with high morbidity and mortality worldwide. Many S. aureus strains are methicillin-resistant (MRSA) or even multi-drug resistant. It is one of the most successful and prominent modern pathogens. An effective fight against S. aureus infections requires novel targets for antimicrobial and antistaphylococcal therapies. Recent advances in whole-genome sequencing and high-throughput techniques facilitate the generation of genome-scale metabolic models (GEMs). Among the multiple applications of GEMs is drug-targeting in pathogens. Hence, comprehensive and predictive metabolic reconstructions of S. aureus could facilitate the identification of novel targets for antimicrobial therapies. This review aims at giving an overview of all available GEMs of multiple S. aureus strains. We downloaded all 114 available GEMs of S. aureus for further analysis. The scope of each model was evaluated, including the number of reactions, metabolites, and genes.Furthermore, all models were quality-controlled using Mᴇᴍᴏᴛᴇ, an open-source application with standardized metabolic tests. Growth capabilities and model similarities were examined. This review should lead as a guide for choosing the appropriate GEM for a given research question. With the information about the availability, the format, and the strengths and potentials of each model, one can either choose an existing model or combine several models to create models with even higher predictive values. This facilitates model-driven discoveries of novel antimicrobial targets to fight multi-drug resistant S. aureus strains.
Project description:Staphylococcus aureus is a high-priority pathogen causing severe infections with high morbidity and mortality worldwide. Many S. aureus strains are methicillin-resistant (MRSA) or even multi-drug resistant. It is one of the most successful and prominent modern pathogens. An effective fight against S. aureus infections requires novel targets for antimicrobial and antistaphylococcal therapies. Recent advances in whole-genome sequencing and high-throughput techniques facilitate the generation of genome-scale metabolic models (GEMs). Among the multiple applications of GEMs is drug-targeting in pathogens. Hence, comprehensive and predictive metabolic reconstructions of S. aureus could facilitate the identification of novel targets for antimicrobial therapies. This review aims at giving an overview of all available GEMs of multiple S. aureus strains. We downloaded all 114 available GEMs of S. aureus for further analysis. The scope of each model was evaluated, including the number of reactions, metabolites, and genes. Furthermore, all models were quality-controlled using Mᴇᴍᴏᴛᴇ, an open-source application with standardized metabolic tests. Growth capabilities and model similarities were examined. This review should lead as a guide for choosing the appropriate GEM for a given research question. With the information about the availability, the format, and the strengths and potentials of each model, one can either choose an existing model or combine several models to create models with even higher predictive values. This facilitates model-driven discoveries of novel antimicrobial targets to fight multi-drug resistant S. aureus strains.