COMPARISON OF BIOTYPING, RIBOTYPING, AND PULSED-FIELD GEL-ELECTROPHORESIS FOR INVESTIGATION OF A COMMON-SOURCE OUTBREAK OF BURKHOLDERIA-PICKETTII BACTEREMIA

Over a 3-month period, six immunocompromised patients developed one or more episodes of Burkholderia pickettii bacteremia and/or catheter in fection, Vials of a commercially available, ''sterile'' saline for inj ection which had been used for Bushing the patients' indwelling intrav enous devices were implicated as the common source of the organisms, N o further cases were diagnosed once the use of this saline was discont inued. Twenty six isolates, including 9 outbreak-related strains from case patients and contaminated saline as well as 17 control strains, w ere tested comparatively by biotyping, ribotyping with EcoRI and HindI II, and pulsed-field gel electrophoresis (PFGE) with SpeI. Macrorestri ction analysis revealed nine PFGE groups and was more discriminating t han ribotyping (seven ribotypes) and biotyping (two biovars), Among th e outbreak-related isolates, one B. pickettii type was found by the th ree typing methods, Furthermore, PFGE was useful for subdividing ribot ypes and for distinguishing isolates involved in the outbreak from all epidemiologically unrelated strains.