Similar Datasets
Project description:Klebsiella pneumoniae clinical isolates, OXA48 and Wt, colistin heteroresistance
| PRJEB66360 | ENA
Project description:To investigate the mechanism of PmB resistance and heteroresistance in Enterobacter bugandensis by analysing the differential gene expression under PmB treatment.
2024-05-01 | GSE218614 | GEO
Project description:Carbapenem-resistant Acinetobacter baumannii (CRAB) is a Priority 1 (Critical) pathogen urgently requiring new antibiotics. Polymyxins are a last-line option against CRAB-associated infections. This transcriptomic study utilized a CRAB strain to investigate mechanisms of bacterial killing with polymyxin B, colistin, colistin B and colistin/sulbactam combination therapy. After 4 h of 2 mg/L polymyxin monotherapy, all polymyxins exhibited common modes of action which primarily involved disruption to amino acid and fatty acid metabolism. Of the three monotherapies, polymyxin B induced the greatest number of differentially expressed genes (DEGs), including for genes involved with fatty acid metabolism. Gene disturbances with colistin and colistin B were highly similar (89% common genes for colistin B), though effects on gene expression were generally lower (0-1.5-fold in most cases) with colistin B. Colistin alone (2 mg/L) or combined with sulbactam (64 mg/L) resulted in rapid membrane disruption as early as 1 h. Transcriptomic analysis of this combination revealed the effects were driven by colistin and included disturbances in fatty acid synthesis and catabolism and inhibition of nutrient uptake. Combination therapy produced substantially higher fold changes in 72% of DEGs shared with monotherapy, resulting in substantially greater reductions in fatty acid biosynthesis and increases in biofilm, cell wall and phospholipid synthesis. This indicates synergistic bacterial killing with the colistin/sulbactam combination results from a systematic increase in perturbation of many genes associated with bacterial metabolism. These mechanistic insights enhance our understanding of bacterial responses to polymyxin mono- and combination therapy and will assist to optimize polymyxin use in patients. Carbapenem-resistant Acinetobacter baumannii (CRAB) is a Priority 1 (Critical) pathogen urgently requiring new antibiotics. Polymyxins are a last-line option against CRAB-associated infections. This transcriptomic study utilized a CRAB strain to investigate mechanisms of bacterial killing with polymyxin B, colistin, colistin B and colistin/sulbactam combination therapy. After 4 h of 2 mg/L polymyxin monotherapy, all polymyxins exhibited common modes of action which primarily involved disruption to amino acid and fatty acid metabolism. Of the three monotherapies, polymyxin B induced the greatest number of differentially expressed genes (DEGs), including for genes involved with fatty acid metabolism. Gene disturbances with colistin and colistin B were highly similar (89% common genes for colistin B), though effects on gene expression were generally lower (0-1.5-fold in most cases) with colistin B. Colistin alone (2 mg/L) or combined with sulbactam (64 mg/L) resulted in rapid membrane disruption as early as 1 h. Transcriptomic analysis of this combination revealed the effects were driven by colistin and included disturbances in fatty acid synthesis and catabolism and inhibition of nutrient uptake. Combination therapy produced substantially higher fold changes in 72% of DEGs shared with monotherapy, resulting in substantially greater reductions in fatty acid biosynthesis and increases in biofilm, cell wall and phospholipid synthesis. This indicates synergistic bacterial killing with the colistin/sulbactam combination results from a systematic increase in perturbation of many genes associated with bacterial metabolism. These mechanistic insights enhance our understanding of bacterial responses to polymyxin mono- and combination therapy and will assist to optimize polymyxin use in patients.
2023-07-01 | GSE218219 | GEO
Project description:Genomic characterization of colistin heteroresistance in Klebsiella pneumoniae during a nosocomial outbreak
| PRJNA312296 | ENA
Project description:Colistin sulfate (polymixin E) is an antibiotic prescribed with resurging frequency for multidrug resistant gram negative bacterial infections. It is associated with nephrotoxicity in humans in up to 33% of cases. Little is known regarding genes involved in colistin nephrotoxicity. A murine model of colistin-mediated kidney injury was developed. C57/BL6 mice were administered saline or colistin at a dose of 16mg/kg/day in 2 divided doses. An Illumina gene expression array was performed on kidney RNA harvested 72 hours after first colistin dose to identify differentially expressed genes early in drug treatment. Array platform was MouseWG-6, 48,000 probes. Drug given intraperitoneal.
2013-11-05 | GSE46410 | GEO
Project description:Heteroresistance in bacteria describes a subpopulational phenomenon of transient antibiotic resistance variation among cells of a generally susceptible population. Here, we investigated the molecular mechanisms and phenotypic characteristics underlying heteroresistance to ceftazidime (CAZ) in a clinical Enterobacter cloacae complex strain (ECC). We identified a plasmid-borne gene duplication-amplification (GDA) event of a region harboring an ampC gene encoding a β-lactamase blaDHA-1 as the key determinant of heteroresistance. Individual colonies exhibited variations in the copy number of the genes resulting in resistance level variation which correlated with growth onset (lag times) and growth rates in the presence of CAZ, analysed in linear models. GDA copy number heterogeneity occurred within single resistant colonies, demonstrating heterogeneity of GDA on the single-cell level. The interdependence between GDA, lag time and antibiotic treatment and the strong plasticity underlying heteroresistance underlines the high risk for misdetection of antimicrobial heteroresistance and subsequent treatment failure.
2024-10-17 | PXD056728 | Pride
Project description:Colistin sulfate (polymixin E) is an antibiotic prescribed with resurging frequency for multidrug resistant gram negative bacterial infections. It is associated with nephrotoxicity in humans in up to 33% of cases. Little is known regarding genes involved in colistin nephrotoxicity. A murine model of colistin-mediated kidney injury was developed. C57/BL6 mice were administered saline or colistin at a dose of 16mg/kg/day in 2 divided doses. An Illumina gene expression array was performed on kidney RNA harvested 72 hours after first colistin dose to identify differentially expressed genes early in drug treatment. Array platform was MouseWG-6, 48,000 probes. Drug given intraperitoneal. Total RNA was isolated from mouse kidneys which were harvested upon sacrifice. 12 total 10 week old C57 bl6 mice were analyzed. Six mice were administered 0.1% saline twice daily, six mice were given colistin at 16 mg/kg/day in 2 divided doses. The 2 groups were randomized to 2 different MouseWG-6_V2_0_R2_11278593 and groups were compared.
2013-11-05 | E-GEOD-46410 | biostudies-arrayexpress
Project description:We found that the antibiotic colistin acts synergistically with antifungals of the echinocandin class (e.g. aminocandin) on C. albicans cells. In order to elucidate the mode of action of colistin in fungi we performed microarray analysis of samples treated with only aminocandin (0.00125µg/ml) or treated with aminocandin (0.00125µg/ml) and colistin (5µg/ml). We compared: (A). untreated cells to cells treated with aminocandin only; (B). cells treated with aminocandin to cells treated with aminocandin and colistin. By comparing those datasets it should be possible to identify genes differentially expressed in response to aminocandin and in response to both drugs. And subsequently to be able to interpret where in the cell colistin acts. (See related experiment in ArrayExpress: E-MEXP-3438)
2012-03-01 | E-MEXP-3437 | biostudies-arrayexpress
Project description:Colistin is a crucial last-line drug used for the treatment of life-threatening infections caused by multi-drug resistant strains of the Gram-negative bacteria, Acinetobacter baumannii. However, colistin resistant A. baumannii isolates can be isolated following failed colistin therapy. Resistance is most often mediated by the addition of phosphoethanolamine (pEtN) to lipid A by PmrC, following missense mutations in the pmrCAB operon encoding PmrC and the two-component signal transduction system PmrA/PmrB. We recovered an isogenic pair of A. baumannii isolates from a single patient before (6009-1) and after (6009-2) failed colistin treatment that displayed low/intermediate and high levels of colistin resistance, respectively. To understand how increased colistin-resistance arose, we genome sequenced each isolate which revealed that 6009-2 had an extra copy of the insertion sequence element ISAba125 within a gene encoding an H-NS-family transcriptional regulator. Consequently, transcriptomic analysis of the clinical isolates identified was performed and more than 150 genes as differentially expressed in the colistin-resistant, hns mutant, 6009-2. Importantly, the expression of eptA, encoding a second lipid A-specific pEtN transferase, but not pmrC, was significantly increased in the hns mutant. This is the first time an H-NS-family transcriptional regulator has been associated with a pEtN transferase and colistin resistance.
2018-02-19 | GSE107964 | GEO