Tags

Type your tag names separated by a space and hit enter

Multidrug resistance pump AcrAB-TolC is required for high-level, Tet(A)-mediated tetracycline resistance in Escherichia coli.
J Antimicrob Chemother. 2006 Jul; 58(1):31-6.JA

Abstract

OBJECTIVES

Starting from the observation that Escherichia coli tolC mutations severely reduced the high-level resistance to tetracycline afforded by Tn10- and plasmid-encoded Tet(A) pumps, we studied the mechanism of this susceptibility.

METHODS

The MIC of tetracycline for MC4100 tolC::Tn10 and several tolC mutants carrying the Tn10 in other sites on the chromosome (thr::Tn10) was determined. The effect of a tolC mutation on the level of expression of Tn10 tet(A) was examined by using a tet(A)::lacZ gene fusion. Influence of tolC mutations on tetracycline efflux and accumulation was quantified by spectrofluorometric assays. The contribution of the AcrAB multidrug efflux system to high-level tetracycline resistance was measured in a Tn10-carrying acrAB null mutant strain.

RESULTS

Tn10- and plasmid-encoded Tet(A) conferred 5- to 6-fold lower levels of tetracycline resistance in tolC mutants, as compared with control strain tolC+. Spectrofluorometric analyses showed that this resulted from a decrease in drug efflux in tolC mutants. Chlortetracycline resistance was also compromised by loss of TolC. Mutational loss of the AcrAB multidrug efflux transporter had the same effect as tolC mutations on tetracycline resistance. This indicated that tolC mutations act through inactivation of the AcrAB system.

CONCLUSIONS

Our results are compatible with the hypothesis that the AcrAB pump is an important component in the development of high levels of resistance to tetracycline in E. coli, perhaps by working in combination with Tet(A).

Authors+Show Affiliations

Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas (Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de Tucumán), Tucumán, Argentina.No affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

16687460

Citation

de Cristóbal, Ricardo E., et al. "Multidrug Resistance Pump AcrAB-TolC Is Required for High-level, Tet(A)-mediated Tetracycline Resistance in Escherichia Coli." The Journal of Antimicrobial Chemotherapy, vol. 58, no. 1, 2006, pp. 31-6.
de Cristóbal RE, Vincent PA, Salomón RA. Multidrug resistance pump AcrAB-TolC is required for high-level, Tet(A)-mediated tetracycline resistance in Escherichia coli. J Antimicrob Chemother. 2006;58(1):31-6.
de Cristóbal, R. E., Vincent, P. A., & Salomón, R. A. (2006). Multidrug resistance pump AcrAB-TolC is required for high-level, Tet(A)-mediated tetracycline resistance in Escherichia coli. The Journal of Antimicrobial Chemotherapy, 58(1), 31-6.
de Cristóbal RE, Vincent PA, Salomón RA. Multidrug Resistance Pump AcrAB-TolC Is Required for High-level, Tet(A)-mediated Tetracycline Resistance in Escherichia Coli. J Antimicrob Chemother. 2006;58(1):31-6. PubMed PMID: 16687460.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Multidrug resistance pump AcrAB-TolC is required for high-level, Tet(A)-mediated tetracycline resistance in Escherichia coli. AU - de Cristóbal,Ricardo E, AU - Vincent,Paula A, AU - Salomón,Raúl A, Y1 - 2006/05/10/ PY - 2006/5/12/pubmed PY - 2006/9/30/medline PY - 2006/5/12/entrez SP - 31 EP - 6 JF - The Journal of antimicrobial chemotherapy JO - J. Antimicrob. Chemother. VL - 58 IS - 1 N2 - OBJECTIVES: Starting from the observation that Escherichia coli tolC mutations severely reduced the high-level resistance to tetracycline afforded by Tn10- and plasmid-encoded Tet(A) pumps, we studied the mechanism of this susceptibility. METHODS: The MIC of tetracycline for MC4100 tolC::Tn10 and several tolC mutants carrying the Tn10 in other sites on the chromosome (thr::Tn10) was determined. The effect of a tolC mutation on the level of expression of Tn10 tet(A) was examined by using a tet(A)::lacZ gene fusion. Influence of tolC mutations on tetracycline efflux and accumulation was quantified by spectrofluorometric assays. The contribution of the AcrAB multidrug efflux system to high-level tetracycline resistance was measured in a Tn10-carrying acrAB null mutant strain. RESULTS: Tn10- and plasmid-encoded Tet(A) conferred 5- to 6-fold lower levels of tetracycline resistance in tolC mutants, as compared with control strain tolC+. Spectrofluorometric analyses showed that this resulted from a decrease in drug efflux in tolC mutants. Chlortetracycline resistance was also compromised by loss of TolC. Mutational loss of the AcrAB multidrug efflux transporter had the same effect as tolC mutations on tetracycline resistance. This indicated that tolC mutations act through inactivation of the AcrAB system. CONCLUSIONS: Our results are compatible with the hypothesis that the AcrAB pump is an important component in the development of high levels of resistance to tetracycline in E. coli, perhaps by working in combination with Tet(A). SN - 0305-7453 UR - https://www.unboundmedicine.com/medline/citation/16687460/Multidrug_resistance_pump_AcrAB_TolC_is_required_for_high_level_Tet_A__mediated_tetracycline_resistance_in_Escherichia_coli_ L2 - https://academic.oup.com/jac/article-lookup/doi/10.1093/jac/dkl172 DB - PRIME DP - Unbound Medicine ER -