The R plasmid, also known as the resistance plasmid, is an extra chromosomal portion of a bacterial gene that allows it to develop resistance to antibiotics. R plasmids are thought to play a role in the growing incidence of antibiotic drug resistance in humans with bacterial infections.
R plasmids move from one bacterial cell to another by conjugation.This involves cell to cell contact and a transfer of the DNA copy to the recipient. Plasmids are seen in various sizes and numbers in the cell. Conjugative transposons are elements similar to plasmids. They move from one cell to another and carry antibiotic resistance.