Alterations of Metabolic and Lipid Profiles in Polymyxin-Resistant Pseudomonas aeruginosa

Han, Mei‐Ling; Zhu, Yan; Creek, Darren J.; Ye, Lin; Anderson, Dovile; Shen, Hsin‐Hui; Tsuji, Brian T.; Gutu, Alina D.; Moskowitz, Samuel M.; Velkov, Tony; Li, Jian

doi:10.1128/aac.02656-17

Cited by 53 publications

(57 citation statements)

References 60 publications

(71 reference statements)

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“…The protein encoded by PA4775 has no homologue within the databases but the open reading frame (ORF) is cotranscribed with speE2 (28) and is required for conferring resistance to dendrimers. Indeed, the speD2 operon was recently described as being responsible for the synthesis of norspermidine (29,37,38). However, addition of spermidine or norspermidine, carrying three amine groups, had no effect on AMP activities.…”

Section: Discussionmentioning

confidence: 99%

Adaptive and Mutational Responses to Peptide Dendrimer Antimicrobials in Pseudomonas aeruginosa

Jeddou

Falconnet

Lüscher

et al. 2020

Antimicrob Agents Chemother

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Colistin (polymyxin E) is a last-resort antibiotic against multidrug-resistant isolates of Pseudomonas aeruginosa. However, the nephro-toxicity of colistin limits its use, spurring the interest in novel antimicrobial peptides (AMP). Here, we show that the synthetic AMP-dendrimer G3KL (MW 4,531.38 Da, 15 positive charges, MIC = 8 mg/liter) showed faster killing than polymyxin B (Pmx-B) with no detectable resistance selection in P. aeruginosa strain PA14. Spontaneous mutants selected on Pmx-B, harboring loss of function mutations in the PhoQ sensor kinase gene, showed increased Pmx-B MICs and arnB operon expression (4-amino-l-arabinose addition to lipid A), but remained susceptible to dendrimers. Two mutants carrying a missense mutation in the periplasmic loop of the PmrB sensor kinase showed increased MICs for Pmx-B (8-fold) and G3KL (4-fold) but not for the dendrimer T7 (MW 4,885.64 Da, 16 positive charges, MIC = 8 mg/liter). The pmrB mutants showed increased expression of the arnB operon as well as of the speD2-speE2-PA4775 operon, located upstream of pmrAB, and involved in polyamine biosynthesis. Exogenous supplementation with the polyamines spermine and norspermine increased G3KL and T7 MICs in a phoQ mutant background but not in the PA14 wild type. This suggests that both addition of 4-amino-l-arabinose and secretion of polyamines are required to reduce susceptibility to dendrimers, probably neutralizing the negative charges present on the lipid A and the 2-keto-3-deoxyoctulosonic acid (KDO) sugars of the lipopolysaccharide (LPS), respectively. We further show by transcriptome analysis that the dendrimers G3KL and T7 induce adaptive responses through the CprRS two-component system in PA14.

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Section: Discussionmentioning

confidence: 99%

Adaptive and Mutational Responses to Peptide Dendrimer Antimicrobials in Pseudomonas aeruginosa

Jeddou

Falconnet

Lüscher

et al. 2020

Antimicrob Agents Chemother

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“…The modification of lipid A, such as the addition of L-Ara4N, phosphoethanolamine, and galactosamine, was linked to homogeneous colistin resistance in various bacteria (12,31). In P. aeruginosa, lipid A is modified with the addition of L-Ara4N through the pmrHFIJKLM operon and under the control of pmrAB and phoPQ, which leads to colistin resistance (32). However, there have been few studies of lipid A structure with respect to colistin heteroresistance.…”

Section: Colistin (Hetero)resistance In Pseudomonas Aeruginosamentioning

confidence: 99%

Resistance and Heteroresistance to Colistin in Pseudomonas aeruginosa Isolates from Wenzhou, China

Lin

Fang

et al. 2019

Antimicrob Agents Chemother

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The goal was to investigate the mechanisms of colistin resistance and heteroresistance in Pseudomonas aeruginosa clinical isolates. Colistin resistance was determined by the broth microdilution method. Colistin heteroresistance was evaluated by population analysis profiling. Time-kill assays were also conducted. PCR sequencing was performed to detect the resistance genes among (hetero)resistant isolates, and quantitative real-time PCR assays were performed to determine their expression levels. Pulsed-field gel electrophoresis and multilocus sequence typing were performed. Lipid A characteristics were determined via matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS). Two resistant isolates and 9 heteroresistant isolates were selected in this study. Substitutions in PmrB were detected in 2 resistant isolates. Among heteroresistant isolates, 8 of 9 heteroresistant isolates had nonsynonymous PmrB substitutions, and 2 isolates, including 1 with a PmrB substitution, had PhoQ alterations. Correspondingly, the expression levels of pmrA or phoP were upregulated in PmrB- or PhoQ-substituted isolates. One isolate also found alterations in ParRS and CprRS. The transcript levels of the pmrH gene were observed to increase across all investigated isolates. MALDI-TOF MS showed additional 4-amino-4-deoxy-l-arabinose (l-Ara4N) moieties in lipid A profiles in (hetero)resistant isolates. In conclusion, both colistin resistance and heteroresistance in P. aeruginosa in this study mainly involved alterations of the PmrAB regulatory system. There were strong associations between mutations in specific genetic loci for lipid A synthesis and regulation of modifications to lipid A. The transition of colistin heteroresistance to resistance should be addressed in future clinical surveillance.

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“…8 The pmrB mutant of P. aeruginosa showed a significant metabolic perturbation in the total intracellular lipid level, the methionine salvage cycle, and synthesis of spermidine. 5 Resistance can be mediated by the addition of positively charged arabinosamine through the action of the arnBCADTEF operon. The results achieved in the present research were consistent with a previous report, in which the complex regulation of LPS modification involved the participation of at least 4 two-component regulatory systems in P. aeruginosa.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies indicated that Gramnegative pathogens exhibited resistance mechanisms of AMPs, including proteolytic degradation of AMPs, shielding of the bacterial surface, modification of the bacterial outer membrane, pumping AMPs into or out of the cell, downregulation of AMP expression, 3,4 diverse genetic alterations, and alterations of amino acids and carbohydrate metabolism. 5,6 Some bacteria (e.g., P. aeruginosa) also could develop resistance to a number of AMPs, such as polymyxin, 7 and reports on resistance of polymyxins in P. aeruginosa have increased. A growing number of P. aeruginosa strains demonstrated resistance to AMPs due to mutations in twocomponent regulatory systems (e.g., PhoPQ and PmrAB).…”

Section: Introductionmentioning

confidence: 99%

<p>Transcriptome Analysis Reveals the Resistance Mechanism of <em>Pseudomonas aeruginosa</em> to Tachyplesin I</p>

Hong

Jiang

et al. 2020

IDR

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Video abstractPoint your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use:https://youtu.be/5BsNhiQUUDIBackground: Tachyplesin I is a cationic antimicrobial peptide with a typical cyclic antiparallel β-sheet structure. We previously demonstrated that long-term continuous exposure to increased concentration of tachyplesin I can induce resistant Gram-negative bacteria. However, no significant information is available about the resistance mechanism of Pseudomonas aeruginosa (P. aeruginosa) to tachyplesin I. Materials and Methods: In this study, the global gene expression profiling of P. aeruginosa strain PA-99 and P. aeruginosa CGMCC1.2620 (PA1.2620) was conducted using transcriptome sequencing. For this purpose, outer membrane permeability and outer membrane proteins (OMPs) were further analyzed.Results: Transcriptome sequencing detected 672 upregulated and 787 downregulated genes, covering Clusters of Orthologous Groups (COGs) of P. aeruginosa strain PA-99 compared with PA1.2620. Totally, 749 differentially expressed genes (DEGs) were assigned to 98 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and among them, a twocomponent regulatory system, a beta-lactam resistance system, etc. were involved in some known genes resistant to drugs. Additionally, we further attempted to indicate whether the resistance mechanism of P. aeruginosa to tachyplesin I was associated with the changes of outer membrane permeability and OMPs. Conclusion: Our results indicated that P. aeruginosa resistant to tachyplesin I was mainly related to reduced entry of tachyplesin I into the bacterial cell due to overexpression of efflux pump, in addition to a decrease of outer membrane permeability. Our findings were also validated by pathway enrichment analysis and quantitative reverse transcription polymerase chain reaction (RT-qPCR). This study may provide a promising guidance for understanding the resistance mechanism of P. aeruginosa to tachyplesin I.

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Alterations of Metabolic and Lipid Profiles in Polymyxin-Resistant Pseudomonas aeruginosa

Cited by 53 publications

References 60 publications

Adaptive and Mutational Responses to Peptide Dendrimer Antimicrobials in Pseudomonas aeruginosa

Adaptive and Mutational Responses to Peptide Dendrimer Antimicrobials in Pseudomonas aeruginosa

Resistance and Heteroresistance to Colistin in Pseudomonas aeruginosa Isolates from Wenzhou, China

<p>Transcriptome Analysis Reveals the Resistance Mechanism of <em>Pseudomonas aeruginosa</em> to Tachyplesin I</p>

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