title: An R plasmid of Serratia marcescens transferable to Pseudomonas aeruginosa.
abstract: Hospital isolates of Serratia marcescens able to transfer resistance to up to 11 antibiotics were found to contain conjugative R plasmids. One set of strains harbors only a single R plasmid with a mass of 89 megadaltons (Mdal). This plasmid codes for resistance to nine antibiotics including ampicillin, carbenicillin, cephalothin, streptomycin, kanamycin, gentamicin, tobramycin, sisomycin, and sulfonamides. The 2nd set of strains harbors 2 R plasmids, 1 with a mass of 89 Mdal, the other 57 Mdal. Analysis of progeny from genetic crosses indicates that the larger R plasmid codes for resistance to the same antibiotics as does the 89-Mdal plasmid described above. The 57-Mdal species codes for resistance to ampicillin, carbenicillin, cephalothin, kanamycin, neomycin, and tetracycline. The 89- and 57-Mdal R plasmids appear unrelated by a number of genetic and physical criteria. The 89-Mdal plasmid, but not the 57-Mdal species, is transferable by conjugation to Pseudomonas aeruginosa, and renders this species stably resistant to carbenicillin, streptomycin, kanamycin, gentamicin, tobramycin, and sisomycin.
mesh_terms: D003227:Conjugation, Genetic; D003470:Culture Media; D004262:DNA Restriction Enzymes / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D009693:Nucleic Acid Hybridization; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D011815:R Factors; D012706:Serratia marcescens / Q000235:genetics*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004262:DNA Restriction Enzymes