RIBOTYPING OF SELECTED ISOLATES OF ENTEROBACTER-CLOACAE AND CLINICAL-DATA RELATED TO BIOTYPE, PHAGE TYPE, O-SEROTYPE, AND RIBOTYPE

in order to evaluate if ribotyping of selected isolates of Enterobacte r cloacae could further elucidate the epidemiology, we performed ribot yping of 109 isolates indistinguishable by bio-, phage-, and O-serotyp ing, with inconclusive typing results, or from patients with more than one isolate. Ribotyping provided additional information, and some cas es of cross-infection or common source of infection were revealed. Und er the supposition that isolates sharing the same ribotype were of the same origin, problems arose with respect to bio-, O-sero, as well as phage typing; In particular a remarkable number of isolates showed dif ferences in phage type. In order to identify possible virulence charac teristics of certain types, clinical data were related to bio-, phage- , O-sero-, and ribotype. Biotype 66 was significantly more frequent am ong blood culture isolates (P=0.001), but this might have reflected th e presence of a certain strain in the environment of the intensive car e unit, where patients were more likely to develop bacteraemia; seroty pe 04 was significantly more frequent among isolates from the urinary tract (P=0.02), and serotype 013 was more frequent among women (P=0.05 ). One ribotype was found only among community-acquired isolates, whic h might suggest that it is a frequent but less virulent strain.