CORRELATION OF 6 METHODS FOR TYPING NOSOCOMIAL ISOLATES OF ACINETOBACTER-BAUMANNII

A comparative study of biotyping, antimicrobial susceptibility, whale- cell protein analysis, plasmid analysis, pulsed-field gel electrophore sis of chromosomal DNA and polymerase chain reaction with arbitrary pr imers of Acinetobacter baumannii isolates from three large hospitals w as performed to determine the best markers for epidemiological purpose s. Ninety-two isolates were included: 38 belonged to a previously desc ribed outbreak and 54 were randomly selected from sporadic cases of in fection. Biotyping, whole-cell protein and plasmid analysis were the l east discriminatory methods, whereas antimicrobial susceptibility and polymerase chain reaction with arbitrary primers showed moderate discr iminatory power. Typing based on pulsed-held gel electrophoresis of ch romosomal DNA appeared to be the best discriminatory method (discrimin ation index of 0.9623). The addition of polymerase chain reaction with arbitrary primers or antimicrobial susceptibility to pulsed-held gel electrophoresis of chromosomal DNA did not further increase the discri minatory power.