[Verification of nosocomial infection chains with Pseudomonas aeruginosa (author's transl)].

With all 3 typing methods (sero, lyso, pyocin type) errors can arise. The pyocin test following heat curing can be expected to give the least erroneous results. This was demonstrated by a test of 200 non-selected strains which were grown within 4 weeks. The possibility exists that a single patient discharges several different strains simultaneously or in succession. These results must be considered when efforts are made to detect infection chains in a hospital.