[Nature of the genetic control of antibiotic resistance in a Pseudomonas aeruginosa BS205 strain].

The clinical strain BS205 of P. aeruginosa is characterized by a high level of resistance to streptomycin, kanamycin, chloramphenicol, sulfanilamide and mercuric chloride. These markers can be transferred to P. aeruginosa PAO by means of transduction with phage F116L or mobilization with plasmid RP4. In the same way as in the initial strain of P. aeruginosa BS205 no plasmid DNA is detected in transducers or transconjugants. After transference to the strains of the transducers or transconjugants containing markers Sm, Km, Cm, Su, and Hg. plasmid Rip 64 of the incompatibility group is eliminated from the cells of these strains when they are grown on the nonselective medium. The genes of resistance to streptomycin, kanamycin, chloramphenicol, sulfanilamide and mercury and the gene(s) of incompatibility specific of the plasmid of the incompatibility group P-3 are included in the DNA fragment of the size of about 24 megadalton. This fragment is probably a defective plasmid not capable of autonomic existence which is integrated into the bacterial chromosome of P. aeruginosa BS205.