Impact of Multiple Antimicrobial Exposures on the Transfer Efficiency of Multidrug Resistance Plasmids in Salmonella enteric
Ontology highlight
ABSTRACT:
ORGANISM(S): Salmonella enterica Escherichia coli J53
PROVIDER: GSE261094 | GEO | 2024/03/25
REPOSITORIES: GEO
Similar Datasets
Project description:Impact of Multiple Antimicrobial Exposures on the Transfer Efficiency of Multidrug Resistance Plasmids in Salmonella enteric
| PRJNA1085278 | ENA
Project description:Plasmid maintenance costs to bacterial hosts is closely linked to the mechanisms that underlie plasmid fitness and how these costs are resolved. Herein, we performed multiple (63) serial passage to explore the compensatory mechanisms of co-evolution of multidrug-resistant IncHI2 plasmid pJXP9 and S. Typhimurium strain ATCC 14028 with or without antibiotic selection. pJXP9 could be maintained at for hundreds of generations even without drug exposure. Decreased lag times and higher competitive advantages were observed in end-point evolved strains bearing pJXP9 compared to ancestral strains. Genomic and transcriptomic analyses revealed that the fitness costs of pJXP9 in ATCC 14028 were derived from not only specific plasmid genes, particularly the multidrug-resistant region and conjugation transfer region I, but also the conflicts resulting from chromosomal gene interactions. Correspondingly, plasmid-borne deletions of these regions could compensate the fitness cost due to the presence of the plasmid. Furthermore, mutations and mRNA alterations in chromosomal genes involved in physiological functions were also adaptative. These functions included decreased flagellar motility, oxidative stress resistance and fumaric acid synthesis, and increased Cu resistance. Our findings suggest that plasmid maintenance through plasmid-bacteria co-evolution is a trade-off between increasing plasmid vertical transmission and impairing its horizontal transmission and bacterial physiological phenotypes.
2022-03-02 | GSE197475 | GEO
Project description:Incomplete antibiotic removal in pharmaceutical wastewater treatment plants (PWWTPs) could lead to the development and spread of antibiotic-resistant bacteria (ARBs) and genes (ARGs) in the environment, posing a growing public health threat. In this study, two multiantibiotic-resistant bacteria, Ochrobactrum intermedium (N1) and Stenotrophomonas acidaminiphila (N2), were isolated from the sludge of a PWWTP in Guangzhou, China. The N1 strain was highly resistant to ampicillin, cefazolin, chloramphenicol, tetracycline, and norfloxacin, while the N2 strain exhibited high resistance to ampicillin, chloramphenicol, and cefazolin. Whole-genome sequencing revealed that N1 and N2 had genome sizes of 0.52 Mb and 0.37 Mb, respectively, and harbored 33 and 24 ARGs, respectively. The main resistance mechanism in the identified ARGs included efflux pumps, enzymatic degradation, and target bypass, with the N1 strain possessing more multidrug-resistant efflux pumps than the N2 strain (22 vs 12). This also accounts for the broader resistance spectrum of N1 than of N2 in antimicrobial susceptibility tests. Additionally, both genomes contain numerous mobile genetic elements (89 and 21 genes, respectively) and virulence factors (276 and 250 factors, respectively), suggesting their potential for horizontal transfer and pathogenicity. Overall, this research provides insights into the potential risks posed by ARBs in pharmaceutical wastewater and emphasizes the need for further studies on their impact and mitigation strategies.
2024-10-20 | E-MTAB-14497 | biostudies-arrayexpress
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:Most cancer deaths result from progression of therapy resistant disease, yet our understanding of this phenotype is limited. Cancer therapies generate stress signals that act upon mitochondria to initiate apoptosis. Mitochondria isolated from neuroblastoma cells were exposed to tBid or Bim, death effectors activated by therapeutic stress. Multidrug resistant tumor cells obtained from children at relapse had markedly attenuated Bak and Bax oligomerization and cytochrome c release (surrogates for apoptotic commitment) in comparison with patient-matched tumor cells obtained at diagnosis. Electron microscopy identified reduced endoplasmic reticulum-mitochondria contacts (ERMCs) in therapy resistant cells, and genetically or biochemically reducing ERMCs in therapy sensitive tumors phenocopied resistance. ERMCs serve as platforms to transfer Ca2+ and bioactive lipids to mitochondria. Reduced Ca2+ transfer was found in some but not all resistant cells, and inhibiting transfer did not attenuate apoptotic signaling. In contrast, reduced ceramide synthesis and transfer was common to resistant cells and its inhibition induced stress resistance. We identify ERMCs as physiologic regulators of apoptosis via ceramide transfer and uncover a previously unrecognized mechanism for cancer multidrug resistance.
2021-11-18 | ST002054 | MetabolomicsWorkbench
Project description:6PPD mouse exposure to study maternal transfer and metabolism. This dataset only contains the exposed animals.
2023-01-04 | MSV000091007 | GNPS
Project description:Analysis of mutational signatures caused by exposure to known mutagens in human induced pluripotent stem (iPS) cells. A reference human iPS cell-line will be exposed to 100 chemicals known or proposed to be mutagenic. Following exposure to mutagen, cells will undergo a period of recovery before sub clones are generated and sequenced. The progenitor “parental” IPS cell-line will be used to generate reference sequence data, in order to determine the mutational signatures acquired as a result of exposure to different mutagens.
| EGAS00001002060 | EGA
Project description:Given the risk of environmental pollution by pharmaceutical compounds and the effects of these compounds on exposed ecosystems, ecologically relevant and realistic assessments are required. However, many studies have been mostly focused on individual responses in a single generation exposed to one-effect concentration. Here, transcriptional responses of the crustacean Daphnia magna to the antibiotic tetracycline across multiple generations and effect concentrations were investigated. The results demonstrated that tetracycline induced different transcriptional responses of daphnids that were dependent on dose and generation. For example, reproduction-related expressed sequence tags (ESTs), including vitellogenin, were distinctly related to the dose-dependent tetracycline exposure, whereas multigenerational exposure induced significant change of molting-related ESTs such as cuticle protein. Sixty-five ESTs were shared in all contrasts, suggesting a conserved mechanism of tetracycline toxicity regardless of exposure concentration or time. Most of them were associated with general stress responses including translation, protein and carbohydrate metabolism, and oxidative phosphorylation. In addition, effects across the dose-response curve showed higher correlative connections among transcriptional, physiological, and individual responses than multigenerational effects. In the multigenerational exposure, the connectivity between adjacent generations decreased with increasing generation number. The results clearly highlight that exposure concentration and time trigger different mechanisms and functions, providing further evidence that multigenerational and dose-response effects cannot be neglected in environmental risk assessment.
2017-10-16 | GSE94439 | GEO
Project description:A549 cells were grown at air liquid interphase (ALI) and exposed to airborne formaldehyde for three days. An exposure platform was developed for this purpose, which provided the volatile analyte in a humidified atmosphere. The platform was composed of a reference and an exposure chamber. Treatments/ Sample code: (A) 0 ppm (not = no treatment) in the exposure chamber and control cells in the reference chamber (co); (B) 0.1 ppm (01 FA) in the exposure chamber and control cells in the reference chamber (co); and (C) 0.5 ppm (05FA) in the exposure chamber and control cells in the reference chamber (co)
2016-12-05 | GSE76790 | GEO
Project description:The delta smelt (Hypomesus transpacificus) is an endangered pelagic fish species endemic to the Sacramento-San Joaquin estuary, California, and considered an indicator of ecosystem health. The experimental combination of molecular biomarkers with higher level condition indicators may allow for interpretation of responses in a functional context that can be used to predict detrimental outcomes caused by contaminant exposure. Copper is a contaminant of concern in Californian waterways that may affect the development and survival of this endangered species. We have developed and applied a delta smelt microarray in order to screen for probable candidate molecular biomarkers that may be used in monitoring programs. Functional classifications of microarray responses are presented along with quantitative Polymerase Chain Reaction (qPCR) assessments measuring effects upon neuromuscular, digestive and immune responses in delta smelt exposed to copper. Differences in sensitivity were measured between juvenile and larval delta smelt (LC¬5096h= 25.2 and 80.4 ?g/L Cu2+ respectively). Swimming velocity declined with higher exposure concentrations in a dose-dependent manner, though were not statistically significant to controls. Genes encoding for aspartoacylase (ASPA), hemopexin, alpha-actin and calcium regulation proteins were significantly affected by exposure and were functionally interpreted with measured swimming responses. Effects on digestion were measured by upregulation of chitinase and downregulation of amylase, whilst downregulation of tumor necrosis factor indicated a probable compromised immune system. We utilized 3 replicates for exposed samples and 3 replicates for controls, both of which were hybridized to a reference pool. Each replicate contained 4 pooled larval delta smelt. The Reference pool consisted of delta smelt samples from this experiment and a number of prior tests. No dye swaps were performed due to limited material. Supplementary file linked below reports candidate differentially expressed cDNAs. Data represented as filtered, normalized, Log-2 Alexa (547/555) ratios.
2010-08-18 | E-GEOD-23238 | biostudies-arrayexpress