[Bacteriocin typing of Enterobacter cloacae strains (author's transl)]

By means of bacteriocin typing epidemic studies were carried out with regard to 65 strains of Enterobacter cloacae, isolated from various specimens of 59 patients. Based on detailed preliminary investigations the presentation with bacteriocins in liquid cultures induced by Mitomycin C was found most preferable. Since constant and reproducible results are essential, standardization of culture media, incubation temperature, incubation time and inoculum size is required. By means of 13 bacteriocin-producing strains the isolates could be typed and categorized into 24 types according to their sensitivity to bacteriocins. A rather varied picture emanated from the distribution of the individual types with regard to the different medical fields so that cross-infection with a certain strain was negligible. Seeing that one bacteriocin type was found predominantly in the intensive care unit, it can be maintained that this strain originated from the ward itself. The importance of bacteriocin typing for the interpretation of certain up-to-date epidemic situations is obvious which typing has also been successfully employed with regard to investigations of Enterobacter cloacae infections. However, it is doubtful whether bacteriocin production and bacteriocin sensitivity sufficiently constant in order to obtain comparable results over a more extended period of time and in different areas.