Identification of drug resistance (R) plasmids from catheter urine

We isolated bacterial strains from catheter urine of patients with underlying diseases and investigated their resistance to various drugs. It was found that Serratia marcescens strains were most frequently isolated, from which R plasmids were identified at a high frequency (70%). According to the resistance patterns of R plasmids, prevalence of multiply resistant S. marcescens strains was concluded by selection of the organism according to drugs used and by infection with the organism, and the spread of R plasmids encoding multiple resistance.