Open AccessA Combination of sbmA and tolC Mutations in Escherichia coli K-12 Tn 10 -Carrying Strains Results in Hypersusceptibility to Tetracycline
Author(s) -
Ricardo Cristóbal,
P Vincent,
Raúl Armando Salomón
Publication year - 2008
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01844-07
Subject(s) - tetracycline , biology , escherichia coli , mutant , transposable element , mutation , phenotype , genetics , microbiology and biotechnology , gene , antibiotics
Previously, we demonstrated thatEscherichia coli tolC mutations reduce the high-level resistance to tetracycline afforded by the transposon Tn10 -encoded TetA pump from resistance at 200 μg/ml to resistance at 40 μg/ml. In this study, we found that the addition of ansbmA mutation to atolC ::Tn10 mutant exacerbates this phenotype: the double mutant did not form colonies, even in the presence of tetracycline at a concentration as low as 5 μg/ml. Inactivation ofsbmA alone partially inhibited high-level tetracycline resistance, from resistance at 200 μg/ml to resistance at 120 μg/ml. There thus appears to be an additive effect of the mutations, resulting in almost complete suppression of the phenotypic expression of Tn10 tetracycline resistance.