AI Article Synopsis
- Exposure to aminoglycosides leads to the development of resistant subpopulations of Pseudomonas aeruginosa, influenced by an efflux system called MexXY-OprM.
- Under antibiotic pressure, the MexY protein is overproduced, whereas OprM levels remain stable, with MexY production correlated to gentamicin concentration.
- Mutants lacking MexXY or OprM cannot develop this adaptive resistance, highlighting the importance of the MexXY efflux system's rapid response in combating drug effects.
Article Abstract
Exposure of Pseudomonas aeruginosa to aminoglycosides frequently selects for recalcitrant subpopulations exhibiting an unstable, "adaptive" resistance to these antibiotics. In this study, we investigated the implication in the phenomenon of MexXY-OprM, an active efflux system known to export aminoglycosides in P. aeruginosa. Immunoblotting experiments demonstrated that the transporter MexY, but not the outer membrane pore OprM, was overproduced during the post-drug exposure adaptation period in wild-type strain PAO1. Furthermore, MexY production was dependent upon the degree of bacterial exposure to gentamicin (drug concentration). In contrast to parental strain PAO1, mutants defective in MexXY or in OprM were unable to develop adaptive resistance. Altogether, these results indicate that the resistance process requires the rapid production of MexXY and the interaction of these proteins with the constitutively produced component OprM.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC152483 | PMC |
| http://dx.doi.org/10.1128/AAC.47.4.1371-1375.2003 | DOI Listing |
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