STUDIES ON THE DRUG RESISTANCE OF STAPHYLOCOCCI AND ESCHERICHIA COLI AGAINST ANTIBIOTICS. II: GENERAL TENDENCY OF RESISTANT STRAINS

To evaluate the changes of the susceptibilities of Staphylococcus aureus and Escherichia coli clinical isolates over a four-year period from 1965 through 1968, we have conducted a series of studies. Results from these studies were used to assess the changes of bacterial sensitivities within groups of bacteria classified according to minimal inhibitory concentrations (MIC) values or having high sensitivity, intermediate sensitivity, or low sensitivity. We were able to compare changes in antibiotic activities more accurately by this technique than by our previous method of comparison of the averages of the MIC values only.