Tetracycline resistance genes are always located on plasmids, transposons and conjugative transposons so that they can be transferred between genera and species of bacteria.

• 四环素耐药基因常与质粒、转座子、接合转座子等可移动性遗传成分相连，在细菌的种间或属间转移，导致其在菌群中广泛分布。