Overexpression of the MexXY Multidrug Efflux System Correlates with Deficient Pyoverdine Production in <i>Pseudomonas aeruginosa</i>

• Main Authors: Kei Ikarashi (Author), Ryo Kutsuna (Author), Junko Tomida (Author), Yoshiaki Kawamura (Author), Yuji Morita (Author)
• Format: Book
• Published: MDPI AG, 2021-05-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

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.

Item Description

10.3390/antibiotics10060658
2079-6382