Overexpression of the MexXY Multidrug Efflux System Correlates with Deficient Pyoverdine Production in <i>Pseudomonas aeruginosa</i>
Multidrug-resistant <i>Pseudomonas aeruginosa</i> poses a serious problem due to hospital- and healthcare-associated infections. A major drug resistance mechanism of <i>P. aeruginosa</i> involves active efflux via resistance nodulation cell division (RND)-type multidrug efflu...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-05-01
|
| Series: | Antibiotics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-6382/10/6/658 |
| Summary: | Multidrug-resistant <i>Pseudomonas aeruginosa</i> poses a serious problem due to hospital- and healthcare-associated infections. A major drug resistance mechanism of <i>P. aeruginosa</i> involves active efflux via resistance nodulation cell division (RND)-type multidrug efflux pumps of which MexXY is increasingly recognized as a primary determinant of aminoglycoside resistance in <i>P. aeruginosa</i>. MexXY overexpression is often observed in drug-resistant <i>P. aeruginosa</i> clinical isolates. MexXY deficiency increased pyoverdine production in all four <i>P. aeruginosa</i> strains we tested. MexXY-overproducing multidrug-resistant <i>P. aeruginosa</i> PA7 exhibited the greatest effect among the strains. Complementation with a MexXY-expressing plasmid restored low-level pyoverdine production in a MexXY-deficient <i>P. aeruginosa</i> mutant from PA7, indicating that MexXY expression decreases pyoverdine production. Because <i>P. aeruginosa</i> produces pyoverdine to acquire iron, MexXY-deficient mutants might be more susceptible to iron deficiency than MexXY-producing strains or might require extra iron. High-risk clones of multidrug-resistant <i>P. aeruginosa</i> reportedly tend to be MexXY overproducers but defective pyoverdine producers. This study suggests that <i>P. aeruginosa</i> reduces production of a virulence factor after acquiring a drug resistance factor. |
|---|---|
| ISSN: | 2079-6382 |