[Bacteriology and chemotherapy]

In a farewell lecture the relevance of bacteriology for the education of medical students is described. In the times of Koch and Pasteur the bacteriological diagnostic of epidemic diseases was the main problems, to day it is the isolation and differentiation of the patient's own bacteria which give the background for resistance or sensitivity tests to chemotherapeutics. The choice of antimicrobial substances depends not only on the sensitivity of the individual bacterial strain or the toxicology of certain substances but also on the necessity to preserve the normal microecology of the gut and other biotopes. This normal bacterial colonisation is an important factor of colonial resistance against superinfection. Other points for the choice of antimicrobial substances are the epidemiological distribution of resistant strains and the possible interference between the immunological system and certain antibiotics.