Effect of antibiotics on fatty acid composition of strains of E. coli K12 carrying R-plasmids.

A dynamic approach was employed for a study of the reaction of the fatty acid pool of sensitive and resistant strains of E. coli K12 in response to the introduction of antibiotics. Bacteria whose resistance is controlled by plasmids exhibited a specific reaction - a reversible increase in the concentration of cis-9,10-methyl-enehexadecanoic acid. Strains of E. coli K12 (C600, J53, CSH-2) carrying plasmids RP4, R6K, R1 drd 19, pMB9, R386, RP1, RtS-1, were studied.