tetC

tetC is a gene that encodes a tetracycline efflux pump protein in bacteria. It is one of several tet determinants that confer resistance to tetracycline antibiotics by actively exporting the drug from the cell, thereby lowering intracellular concentrations to subinhibitory levels.

Genetic context and distribution: tetC is commonly located on plasmids, transposons, or other mobile genetic elements, enabling horizontal transfer between bacteria. It has been identified in a range of taxa, including diverse Gram-negative species and in some Gram-positive bacteria, and it often co-occurs with other tetracycline resistance genes on the same genetic element.

Mechanism and regulation: The TetC protein is an inner membrane transporter that uses the proton motive force to expel tetracycline. Expression of tetC can be regulated by nearby regulatory genes, frequently of the TetR family, and may be inducible in the presence of tetracycline or related compounds.

Clinical and environmental significance: The presence of tetC contributes to tetracycline resistance in both clinical isolates and environmental or agricultural settings. Detection and surveillance typically rely on molecular methods such as PCR assays targeting tetC and sequencing, as well as broader approaches like whole-genome sequencing.

Evolution and diversity: tetC exists in multiple allelic variants, with potential differences in substrate range and regulatory control. The tet gene family is highly mobile, reflecting ongoing adaptation and contributing to the spread of tetracycline resistance across different ecological niches.