Quantification of the Antibacterial Action of Trimethoprim Alone and in Combination with Sulfonamides by Bacterial Growth Kinetics

摘要: The dependence of growth rates Escherichia coli on sulfonamides or trimethoprim (TMP) has been established. new steady state is obtained shortly after addition TMP, whereas a lag phase about five generations observed for sulfonamides. inhibitory effect TMP times larger than the sulfamethoxazole (SMZ) as evaluated from plot 1/ko-kapp vs. 1/C. well that reversible if drug containing culture diluted. Whereas sulfonamide only bacteriostatic, can cause bacterial death certain threshold concentration ( 1 tM) passed; decrease in number bacteria observed. Combinations and at concentrations where both drugs act merely bacteriostatically lead to effects considerably greater would be expected simple additivity. It justifiable say combination synergistic effect.