Acquired resistance of Staphylococcus aureus (strain FDA 209P JC-1, strain CN 491) and Escherichia coli (strain NIHJ JC-2, strain CN 314 and strain K-12) to TMP alone, SMX alone and their combinations (SMX-TMP) have been studied by serial transfer of light inoculum (104cells/ml) in increasing concentrations of drugs in MUELLER-HINTON broth (Eiken) or SR medium (Difco).
It was concluded from the results of this investigation that the increases in resistance to combinations (SMX-TMP) were less than those to SMX alone and TMP alone.
