[A clinical study on postantibiotic effect (PAE) and its application to chemotherapy for complicated cystitis with an...

In an in vitro complicated cystitis model, the concentrations of the urinary antimicrobial agents were determined using a computer-controlled automatic urine concentration simulator. The effects on the bacterial count curves showing the presence or absence of PAE in antimicrobial agents were studied by comparing the times required for regrowth to the concentration at the initial inoculation, i.e., effective regrowth time (ERT). The following results were obtained. 1. When beta-lactam antimicrobial agents (such as AMPC and CFIX) with no PAE against the gram-negative rods were tested, the ERT of the gram-negative rods were about two hours shorter than that of the gram-positive coccus. 2. When new quinolone antimicrobial agents (such as OFLX) and aminoglycosides (such as ISP) that possess PAE against both the gram-positive and negative organisms were used there was no difference between ERT of the gram-negative rods and gram-positive coccus. Therefore, it was demonstrated that the presence or absence of PAE is also reflected in the cell number curve in the case of this in vitro model, more closely related to clinical cases, when the antibiotics is simulated in urinary concentration shifting.