Project description:Antibiotic resistance is exacerbated by the exchange of antibiotic resistance genes (ARGs) between microbes from diverse habitats. Plasmids are important ARGs mobile elements and are spread by horizontal gene transfer (HGT). In this study, we demonstrated the presence of multi-resistant plasmids from inhalable particulate matter (PM) and its effect on gene horizontal transfer. Three transferable multi-resistant plasmids were identified from PM in a hospital, using conjugative mating assays and nanopore sequencing. pTAir-3 contained 26 horizontal transfer elements and 10 ARGs. Importantly pTAir-5 harbored carbapenem resistance gene (blaOXA) which shows homology to plasmids from human and pig commensal bacteria, thus indicating that PM is a media for antibiotic resistant plasmid spread. In addition, 125 μg/mL PM2.5 and PM10 significantly increased the conjugative transfer rate by 110% and 30%, respectively, and augmented reactive oxygen species (ROS) levels. Underlying mechanisms were revealed by identifying the upregulated expressional levels of genes related to ROS, SOS, cell membranes, pilus generation, and transposition via genome-wide RNA sequencing. The study highlights the airborne spread of multi-resistant plasmids and the impact of inhalable PM on the horizontal transfer of antibiotic resistance.
Project description:Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here we demonstrate that inactivation of a central regulator of iron homeostasis (fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated a substantial reorganization of the Fur regulon in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, over-expression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, while inhibition of the SOS response-mediated mutagenesis had no such effect in fur deficient population. In sum, our work revealed the central role of iron metabolism in de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies. We used microarrays to identify genotype specific transcriptional changes under severe DNA damaging conditions (antibiotic ciprofloxacin). We treated Escherichia coli cells with a highly toxic level of ciprofloxacin (gyrase inhibitor) for RNA extraction and hybridization on Affymetrix microarrays. We planned to find genotype specific transcriptional responses using WT control (BW25113) and fur-knockout mutant (selected from the KEIO collection) strains during antibiotic treatments. For each treatment type we used two biological replicates.
Project description:Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here we demonstrate that inactivation of a central regulator of iron homeostasis (fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated a substantial reorganization of the Fur regulon in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, over-expression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, while inhibition of the SOS response-mediated mutagenesis had no such effect in fur deficient population. In sum, our work revealed the central role of iron metabolism in de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies. We used microarrays to identify genotype specific transcriptional changes under severe DNA damaging conditions (antibiotic ciprofloxacin).
2014-09-11 | GSE55662 | GEO
Project description:Dynamics of antibiotic and antibiotic resistance genes during spectinomycin mycelia dregs fermenting
| PRJNA723988 | ENA
Project description:Stduy of removing antibiotic resistance genes during composting maturity phase
Project description:Pseudomonas aeruginosa infections can be virtually impossible to eradicate and the evolution of resistance during antibiotic therapy is a significant concern. In this study, we use DNA microarrays to characterize the global transcriptional response of P. aeruginosa to clinical-like doses of the antibiotic ciprofloxacin and also to determine the component that is regulated by LexA cleavage and the SOS response. We find that genes involved in virtually every facet of metabolism are down-regulated in response to ciprofloxacin. The LexA-controlled SOS regulon identified by microarray analysis includes only fifteen genes, but does include several genes that encode proteins involved in recombination and replication, including two inducible polymerases known to play a role in mutation and the evolution of antibiotic resistance in other organisms. The data suggests that the inhibition of LexA cleavage during therapy might help combat this pathogen by decreasing its ability to adapt and evolve resistance. Keywords: Time course of response of P. aeruginosa to the antibiotic ciprofloxacin
2006-08-04 | GSE5443 | GEO
Project description:antibiotic resistance genes in soils