Tetracycline Resistance Determinants from Groups A to D Vary in Their Ability to Confer Decreased Accumulation of Tetracycline Derivatives by Escherichia coli
Chopra, Ian and Shales, Stuart and Ball, Peter,, 128, 689-692 (1982),
doi = https://doi.org/10.1099/00221287-128-4-689,
publicationName = Microbiology Society,
issn = 1350-0872,
abstract= The ability of four genetically distinct plasmid-located tetracycline resistance determinants (Tet A, B, C and D) to confer decreased accumulation of tetracycline and some of its analogues by Escherichia coli K12 was examined. Accumulation of oxytetracycline, tetracycline, demethylchlorotetracycline, 6-demethyl-6-deoxy-5-hydroxy-6-methylene-tetracycline, chlorotetracycline, doxycycline and 6-demethyl-6-deoxytetracycline was examined by fluorescence spectroscopy. The determinants varied in their ability to promote decreased accumulation of tetracyclines, defined as an R+/R− fluorescence ratio of < 0·85. Plasmid pIP7 (TetA) caused reduced accumulation of only oxytetracycline, tetracycline and chlorotetracycline, but plasmid pDU301 (TetB) promoted reduced accumulation of all the compounds tested except 6-demethyl-6-deoxytetracycline. The TetC determinant of pBR322 caused decreased uptake of five derivatives, but not doxycycline or 6-demethyl-6-deoxytetra-cycline. Plasmid RA1 (TetD) encoded reduced accumulation of oxytetracycline, tetracycline, 6-demethyl-6-deoxy-5-hydroxy-6-methylenetetracycline and chlorotetracycline. In general, the resistance determinants were more efficient in promoting decreased accumulation of hydrophilic tetracyclines. These accumulation studies provide a satisfactory method for the phenotypic identification of Tet resistance determinants.,
language=,
type=