title: Relationship between pigment producibility and drug resistance in Serratia marcescens.
abstract: Among the clinical isolates of Serratia marcescens, non-pigmented cells appeared more frequently from pigmented, drug-resistant strains than from pigmented, drug-sensitive strains. Transfer of R plasmid from Escherichia coli to pigmented strains caused spontaneous loss of pigment producibility, whereas such spontaneous loss never occurred in fresh cultures of drug-sensitive strains. The non-pigmented strain was a better recipient of R plasmid from E. coli than was the pigmented strain. R plasmid was transferred from the non-pigmented strain to the pigmented strain at a higher frequency than from E. coli to the pigmented strain. The results of the present investigation suggest that transfer of R plasmid may be one of the reasons for the significant increase of non-pigmented, drug-resistant strains of S. marcescens in nature.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D010860:Pigments, Biological / Q000096:biosynthesis*; D011815:R Factors; D012706:Serratia marcescens / Q000187:drug effects* / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D010860:Pigments, Biological