Contribution of the MexX-MexY-OprM Efflux System to Intrinsic Resistance in Pseudomonas aeruginosa

@article{Masuda2000ContributionOT,
  title={Contribution of the MexX-MexY-OprM Efflux System to Intrinsic Resistance in Pseudomonas aeruginosa},
  author={Nobuhisa Masuda and Eiko Sakagawa and Satoshi Ohya and Naomasa Gotoh and Hideto Tsujimoto and Takeshi Nishino},
  journal={Antimicrobial Agents and Chemotherapy},
  year={2000},
  volume={44},
  pages={2242 - 2246}
}
ABSTRACT To test the possibility that MexX-MexY, a new set of efflux system components, is associated with OprM and contributes to intrinsic resistance in Pseudomonas aeruginosa, we constructed a series of isogenic mutants lacking mexXY and/ormexAB and/or oprM from a laboratory strain PAO1, and examined their susceptibilities to ofloxacin, tetracycline, erythromycin, gentamicin, and streptomycin. Loss of either MexXY or OprM from the MexAB-deficient mutant increased susceptibility to all agents… Expand
Roles of MexXY- and MexAB-multidrug efflux pumps in intrinsic multidrug resistance of Pseudomonas aeruginosa PAO1.
TLDR
It was found that each pump compensated to some extent for the lack of another pump with respect to the common substrates (tetracycline, quinolones, and cefpirome). Expand
Clinical Strains of Pseudomonas aeruginosa Overproducing MexAB-OprM and MexXY Efflux Pumps Simultaneously
TLDR
Data show that clinical isolates are able to broaden their drug resistance profiles by coexpressing two Mex efflux pumps and suggest the existence of additional regulators for MexAB-OprM and MexXY. Expand
Mutations in PA2491 (mexS) Promote MexT-Dependent mexEF-oprN Expression and Multidrug Resistance in a Clinical Strain of Pseudomonas aeruginosa
TLDR
Spontaneous multidrug-resistant mutants of the P. aeruginosa clinical isolate hyperexpressing mexEF-oprN and showing reduced production of OprD were readily selected in vitro, and all of them were shown to carry mutations in PA2491, highlighting the probable significance of such mutations as determinants of MexEF-OprN-mediated multidrog resistance in vivo. Expand
Fmt Bypass in Pseudomonas aeruginosa Causes Induction of MexXY Efflux Pump Expression
TLDR
Transcriptional profiling and/or mexX::lux promoter fusion analysis revealed that fmt and folD mutants were strongly upregulated for mexXY and another gene known to be required for upregulation of the pump, PA5471, which supports the notion that MexXY has a natural physiological function responding to impairment of ribosome function or protein synthesis and that fmt mutation (Fmt bypass) and fol D mutation generate the intracellular mex XY-inducing signal. Expand
Resistance and Virulence of Pseudomonas aeruginosa Clinical Strains Overproducing the MexCD-OprJ Efflux Pump
TLDR
Data show that, while rather infrequent among P. aeruginosa strains with low-level resistance to ciprofloxacin, MexCD-OprJ-overproducing mutants may be isolated after single therapy with fluoroquinolones and may be pathogenic. Expand
Polymyxin Susceptibility in Pseudomonas aeruginosa Linked to the MexXY-OprM Multidrug Efflux System
TLDR
It is possible that some additional change in LPS promoted by SPC-induced mexXY expression impacted CPA synthesis or its incorporation into LPS and that this was responsible for the observed changes in polymyxin susceptibility. Expand
Expression of the MexXY efflux pump in amikacin-resistant isolates of Pseudomonas aeruginosa.
  • S. Islam, S. Jalal, B. Wretlind
  • Biology, Medicine
  • Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases
  • 2004
TLDR
The MexZ-MexX-MexY multidrug efflux system in Pseudomonas aeruginosa was studied to determine its contribution to aminoglycoside resistance and the effect of mexZ and mexOZ mutations, and the production of MexY mRNA was investigated quantitatively by real-time PCR. Expand
A Two-Component Regulatory System Interconnects Resistance to Polymyxins, Aminoglycosides, Fluoroquinolones, and β-Lactams in Pseudomonas aeruginosa
TLDR
The data indicate that ParRS may promote either induced or constitutive multidrug resistance to four different classes of antibiotics through the activation of three distinct mechanisms (efflux, porin loss, and LPS modification). Expand
Enhancement of the mexAB-oprM Efflux Pump Expression by a Quorum-Sensing Autoinducer and Its Cancellation by a Regulator, MexT, of the mexEF-oprN Efflux Pump Operon in Pseudomonas aeruginosa
TLDR
It was concluded that β-lactam hypersusceptibility in nfxC-type mutant cells is caused by MexT-mediated cancellation of C4-HSL-mediated enhancement of MexAB-OprM expression. Expand
Substrate Specificities of MexAB-OprM, MexCD-OprJ, and MexXY-OprM Efflux Pumps in Pseudomonas aeruginosa
TLDR
To find the exact substrate specificities of three species of tripartite efflux systems of Pseudomonas aeruginosa, MexAB-OprM, MexCD- oprJ, and MexXY-OPRM, a series of isogenic mutants were constructed, each constitutively overproduced one of the three efflux system and lacked the other two. Expand
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TLDR
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TLDR
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