Use of agarose gel electrophoresis of plasmid deoxyribonucleic acid to fingerprint gram-negative bacilli

Abstract

Agarose gel electrophoresis of the plasmid DNA from 60 gram-negative bacilli recovered during investigations of nosocomial epidemics was used to fingerprint the strains. This method was as specific at differentiating bacterial strains as more conventional phenotyping methods. In all cases, plasmid band fingerprints of epidemic strain isolates were identical; coisolate plasmid DNA patterns were different. Agarose gel electrophoresis of plasmid DNA is proposed as a method which can be used in conventional microbiology laboratories as an adjunct to or, possibly, replacement for other methods of identifying bacterial strains.