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Overexpression of the MexEF-OprN multidrug efflux system affects cell-to-cell signaling in Pseudomonas aeruginosa.
J Bacteriol. 2001 Sep; 183(18):5213-22.JB

Abstract

Intrinsic and acquired antibiotic resistance of the nosocomial pathogen Pseudomonas aeruginosa is mediated mainly by the expression of several efflux pumps of broad substrate specificity. Here we report that nfxC type mutants, overexpressing the MexEF-OprN efflux system, produce lower levels of extracellular virulence factors than the susceptible wild type. These include pyocyanin, elastase, and rhamnolipids, three factors controlled by the las and rhl quorum-sensing systems of P. aeruginosa. In agreement with these observations are the decreased transcription of the elastase gene lasB and the rhamnosyltransferase genes rhlAB measured in nfxC type mutants. Expression of the lasR and rhlR regulator genes was not affected in the nfxC type mutant. In contrast, transcription of the C4-homoserine lactone (C4-HSL) autoinducer synthase gene rhlI was reduced by 50% in the nfxC type mutant relative to that in the wild type. This correlates with a similar decrease in C4-HSL levels detected in supernatants of the nfxC type mutant. Transcription of an rhlAB-lacZ fusion could be partially restored by the addition of synthetic C4-HSL and Pseudomonas quinolone signal (PQS). It is proposed that the MexEF-OprN efflux pump affects intracellular PQS levels.

Authors+Show Affiliations

Department of Genetics and Microbiology, Centre Médical Universitaire, CH-1211 Geneva 4, Switzerland. Thilo.Kohler@medecine.unige.chNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

11514502

Citation

Köhler, T, et al. "Overexpression of the MexEF-OprN Multidrug Efflux System Affects Cell-to-cell Signaling in Pseudomonas Aeruginosa." Journal of Bacteriology, vol. 183, no. 18, 2001, pp. 5213-22.
Köhler T, van Delden C, Curty LK, et al. Overexpression of the MexEF-OprN multidrug efflux system affects cell-to-cell signaling in Pseudomonas aeruginosa. J Bacteriol. 2001;183(18):5213-22.
Köhler, T., van Delden, C., Curty, L. K., Hamzehpour, M. M., & Pechere, J. C. (2001). Overexpression of the MexEF-OprN multidrug efflux system affects cell-to-cell signaling in Pseudomonas aeruginosa. Journal of Bacteriology, 183(18), 5213-22.
Köhler T, et al. Overexpression of the MexEF-OprN Multidrug Efflux System Affects Cell-to-cell Signaling in Pseudomonas Aeruginosa. J Bacteriol. 2001;183(18):5213-22. PubMed PMID: 11514502.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Overexpression of the MexEF-OprN multidrug efflux system affects cell-to-cell signaling in Pseudomonas aeruginosa. AU - Köhler,T, AU - van Delden,C, AU - Curty,L K, AU - Hamzehpour,M M, AU - Pechere,J C, PY - 2001/8/22/pubmed PY - 2001/9/28/medline PY - 2001/8/22/entrez SP - 5213 EP - 22 JF - Journal of bacteriology JO - J. Bacteriol. VL - 183 IS - 18 N2 - Intrinsic and acquired antibiotic resistance of the nosocomial pathogen Pseudomonas aeruginosa is mediated mainly by the expression of several efflux pumps of broad substrate specificity. Here we report that nfxC type mutants, overexpressing the MexEF-OprN efflux system, produce lower levels of extracellular virulence factors than the susceptible wild type. These include pyocyanin, elastase, and rhamnolipids, three factors controlled by the las and rhl quorum-sensing systems of P. aeruginosa. In agreement with these observations are the decreased transcription of the elastase gene lasB and the rhamnosyltransferase genes rhlAB measured in nfxC type mutants. Expression of the lasR and rhlR regulator genes was not affected in the nfxC type mutant. In contrast, transcription of the C4-homoserine lactone (C4-HSL) autoinducer synthase gene rhlI was reduced by 50% in the nfxC type mutant relative to that in the wild type. This correlates with a similar decrease in C4-HSL levels detected in supernatants of the nfxC type mutant. Transcription of an rhlAB-lacZ fusion could be partially restored by the addition of synthetic C4-HSL and Pseudomonas quinolone signal (PQS). It is proposed that the MexEF-OprN efflux pump affects intracellular PQS levels. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/11514502/Overexpression_of_the_MexEF_OprN_multidrug_efflux_system_affects_cell_to_cell_signaling_in_Pseudomonas_aeruginosa_ L2 - http://jb.asm.org/cgi/pmidlookup?view=long&pmid=11514502 DB - PRIME DP - Unbound Medicine ER -