A conjugative plasmid that is responsible for resistance to various elements in bacterial cells, including antibiotics, metal ions, ultraviolet radiation, bacteriophage, and ethidium bromide.
Tests to find out whether the additive is capable of selecting resistance factors. These tests are to be performed under field conditions in the animal species for which the additive is primarily intended. Subsequently, it should be determined whether R factors which may have been found carry multiple resistance and are transmissible.
