title: Transformation of tetracycline by TetX and its subsequent degradation in a heterologous host.
abstract: TetX is a flavin-dependent monooxygenase. It has been reported to inactivate all tested tetracyclines. In this study, Escherichia coli overexpressing TetX was added to soil bacterial enrichment cultures along with varying levels of tetracycline and was found to affect community-wide tetracycline resistance levels. Soil microbial communities developed lower levels of tetracycline resistance upon exposure to 25 μg/mL of tetracycline when an E. coli expressing TetX was present (6% of cultivable bacteria were resistant to 40 μg/mL tetracycline). In contrast, in the absence of TetX activity, a similar tetracycline exposure selected for greater levels of resistant bacteria in the soil microbial community (90% of cultivable bacteria were resistant to 40 μg/mL tetracycline). We also describe new metabolites formed after tetracycline transformation by TetX and report the transient generation of redox-active metabolite(s). The results presented here are particularly pertinent in the light of the recent emergence of tet(X) in different bacterial species, including clinical isolates.
authors.affiliation: Biotechnology Institute, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Biotechnology Institute, University of Minnesota, St. Paul, MN 55108, USA Department of Civil, Environmental and Geo- Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: LaPara
authors.affiliation: Biotechnology Institute, University of Minnesota, St. Paul, MN 55108, USA Department of Soil, Water and Climate, University of Minnesota, St. Paul, MN 55108, USA sadowsky@umn.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sadowsky
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D018014:Gene Transfer Techniques; D008826:Microbial Sensitivity Tests; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D012988:Soil Microbiology; D013752:Tetracycline / Q000378:metabolism*; D013753:Tetracycline Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D006899:Mixed Function Oxygenases; D013752:Tetracycline
keywords: Escherichia coli; Sphingobacterium; TetX, monooxygenase; antibiotic resistance