Amino Acid Substitutions Account for Most MexS Alterations in Clinical NfxC Mutants of Pseudomonas Aeruginosa

Overview

Journal Antimicrob Agents Chemother

Publisher American Society for Microbiology

Specialty Pharmacology

Date 2016 Feb 3

PMID 26833155

Citations 38

Authors

Charlotte Richardot

Paulo Juarez

Katy Jeannot

Isabelle Patry

Patrick Plesiat

Catherine Llanes

Affiliations

Soon will be listed here.

Abstract

Multidrug-resistant mutants ofPseudomonas aeruginosathat overproduce the active efflux system MexEF-OprN (callednfxCmutants) have rarely been characterized in the hospital setting. Screening of 221 clinical strains exhibiting a reduced susceptibility to ciprofloxacin (a substrate of MexEF-OprN) and imipenem (a substrate of the negatively coregulated porin OprD) led to the identification of 43 (19.5%)nfxCmutants. Subsequent analysis of 22 nonredundant mutants showed that, in contrast to theirin vitro-selected counterparts, only 3 of them (13.6%) harbored a disruptedmexSgene, which codes for the oxidoreductase MexS, whose inactivation is known to activate themexEF-oprNoperon through a LysR-type regulator, MexT. Nine (40.9%) of the clinicalnfxCmutants contained single amino acid mutations in MexS, and these were associated with moderate effects on resistance and virulence factor production in 8/9 strains. Finally, the remaining 10 (45.5%)nfxCmutants did not display mutations in any of the regulators known to controlmexEF-oprNexpression (themexS,mexT,mvaT, andampRgenes), confirming that other loci are responsible for pump upregulation in patients. Collectively, these data demonstrate thatnfxCmutants are probably more frequent in the hospital than previously thought and have genetic and phenotypic features somewhat different from those ofin vitro-selected mutants.

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References

Lamarche M, Deziel E . MexEF-OprN efflux pump exports the Pseudomonas quinolone signal (PQS) precursor HHQ (4-hydroxy-2-heptylquinoline). PLoS One. 2011; 6(9):e24310. PMC: 3177830. DOI: 10.1371/journal.pone.0024310. View

Jin Y, Yang H, Qiao M, Jin S . MexT regulates the type III secretion system through MexS and PtrC in Pseudomonas aeruginosa. J Bacteriol. 2010; 193(2):399-410. PMC: 3019812. DOI: 10.1128/JB.01079-10. View

Gellatly S, Hancock R . Pseudomonas aeruginosa: new insights into pathogenesis and host defenses. Pathog Dis. 2013; 67(3):159-73. DOI: 10.1111/2049-632X.12033. View

Linares J, Lopez J, Camafeita E, Albar J, Rojo F, Martinez J . Overexpression of the multidrug efflux pumps MexCD-OprJ and MexEF-OprN is associated with a reduction of type III secretion in Pseudomonas aeruginosa. J Bacteriol. 2005; 187(4):1384-91. PMC: 545608. DOI: 10.1128/JB.187.4.1384-1391.2005. View

Ohman D, Cryz S, Iglewski B . Isolation and characterization of Pseudomonas aeruginosa PAO mutant that produces altered elastase. J Bacteriol. 1980; 142(3):836-42. PMC: 294108. DOI: 10.1128/jb.142.3.836-842.1980. View

Ditta G, Stanfield S, Corbin D, Helinski D . Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti. Proc Natl Acad Sci U S A. 1980; 77(12):7347-51. PMC: 350500. DOI: 10.1073/pnas.77.12.7347. View

Lacks S, Greenberg B . Complementary specificity of restriction endonucleases of Diplococcus pneumoniae with respect to DNA methylation. J Mol Biol. 1977; 114(1):153-68. DOI: 10.1016/0022-2836(77)90289-3. View

Kohler T, van Delden C, Curty L, Hamzehpour M, Pechere J . Overexpression of the MexEF-OprN multidrug efflux system affects cell-to-cell signaling in Pseudomonas aeruginosa. J Bacteriol. 2001; 183(18):5213-22. PMC: 95401. DOI: 10.1128/JB.183.18.5213-5222.2001. View

Olivares J, Alvarez-Ortega C, Linares J, Rojo F, Kohler T, Luis Martinez J . Overproduction of the multidrug efflux pump MexEF-OprN does not impair Pseudomonas aeruginosa fitness in competition tests, but produces specific changes in bacterial regulatory networks. Environ Microbiol. 2012; 14(8):1968-81. DOI: 10.1111/j.1462-2920.2012.02727.x. View

10.

Kohler T, Epp S, Curty L, Pechere J . Characterization of MexT, the regulator of the MexE-MexF-OprN multidrug efflux system of Pseudomonas aeruginosa. J Bacteriol. 1999; 181(20):6300-5. PMC: 103763. DOI: 10.1128/JB.181.20.6300-6305.1999. View

11.

Morita Y, Tomida J, Kawamura Y . Efflux-mediated fluoroquinolone resistance in the multidrug-resistant Pseudomonas aeruginosa clinical isolate PA7: identification of a novel MexS variant involved in upregulation of the mexEF-oprN multidrug efflux operon. Front Microbiol. 2015; 6:8. PMC: 4301020. DOI: 10.3389/fmicb.2015.00008. View

12.

Kumar A, Schweizer H . Evidence of MexT-independent overexpression of MexEF-OprN multidrug efflux pump of Pseudomonas aeruginosa in presence of metabolic stress. PLoS One. 2011; 6(10):e26520. PMC: 3200333. DOI: 10.1371/journal.pone.0026520. View

13.

Fargier E, Mac Aogain M, Mooij M, Woods D, Morrissey J, Dobson A . MexT functions as a redox-responsive regulator modulating disulfide stress resistance in Pseudomonas aeruginosa. J Bacteriol. 2012; 194(13):3502-11. PMC: 3434746. DOI: 10.1128/JB.06632-11. View

14.

Essar D, Eberly L, Hadero A, Crawford I . Identification and characterization of genes for a second anthranilate synthase in Pseudomonas aeruginosa: interchangeability of the two anthranilate synthases and evolutionary implications. J Bacteriol. 1990; 172(2):884-900. PMC: 208517. DOI: 10.1128/jb.172.2.884-900.1990. View

15.

Westfall L, Carty N, Layland N, Kuan P, Colmer-Hamood J, Hamood A . mvaT mutation modifies the expression of the Pseudomonas aeruginosa multidrug efflux operon mexEF-oprN. FEMS Microbiol Lett. 2006; 255(2):247-54. DOI: 10.1111/j.1574-6968.2005.00075.x. View

16.

Schweizer H . Efflux as a mechanism of resistance to antimicrobials in Pseudomonas aeruginosa and related bacteria: unanswered questions. Genet Mol Res. 2003; 2(1):48-62. View

17.

Balasubramanian D, Schneper L, Merighi M, Smith R, Narasimhan G, Lory S . The regulatory repertoire of Pseudomonas aeruginosa AmpC ß-lactamase regulator AmpR includes virulence genes. PLoS One. 2012; 7(3):e34067. PMC: 3315558. DOI: 10.1371/journal.pone.0034067. View

18.

Fukuda H, Hosaka M, Hirai K, Iyobe S . New norfloxacin resistance gene in Pseudomonas aeruginosa PAO. Antimicrob Agents Chemother. 1990; 34(9):1757-61. PMC: 171918. DOI: 10.1128/AAC.34.9.1757. View

19.

Tian Z, Mac Aogain M, OConnor H, Fargier E, Mooij M, Adams C . MexT modulates virulence determinants in Pseudomonas aeruginosa independent of the MexEF-OprN efflux pump. Microb Pathog. 2009; 47(4):237-41. DOI: 10.1016/j.micpath.2009.08.003. View

20.

Dumas J, Van Delden C, Perron K, Kohler T . Analysis of antibiotic resistance gene expression in Pseudomonas aeruginosa by quantitative real-time-PCR. FEMS Microbiol Lett. 2006; 254(2):217-25. DOI: 10.1111/j.1574-6968.2005.00008.x. View