In vitro activities of pazufloxacin, a novel injectable quinolone, against bacteria causing infections in obstetric and gynecological patients

Concentration-Dependent Activity of Pazufloxacin against Pseudomonas aeruginosa: An In Vivo Pharmacokinetic/Pharmacodynamic Study

The bacterium Pseudomonas aeruginosa is known to be associated with nosocomial infections around the world. Pazufloxacin, a potent DNA gyrase inhibitor, is known to be an effective drug candidate. However, it has not been clarified whether the pharmacokinetic (PK)/pharmacodynamic (PD) of pazufloxacin was effective against P. aeruginosa. Herein, we demonstrated that the PK/PD index of pazufloxacin against P. aeruginosa infection is used to optimize the dosing regiments. We constructed an in vivo infection model by infecting P. aeruginosa into the thigh of a mouse to determine the PD, and we measured the serum concentration of pazufloxacin to construct the PK model using high-performance liquid chromatography. The therapeutic efficacy of pazufloxacin was correlated with the ratio of the area under the free concentration time curve at 24 h to the minimum inhibitory concentration (fAUC24/MIC), and the maximum free concentration to the MIC (fCmax/MIC). Each contribution rate (R2) was 0.72 and 0.65, respectively, whereas the time at which the free drug concentration remained above the MIC (R2 = 0.28). The target value of pazufloxacin fAUC24/MIC for stasis was 46.1, for 1 log10 it was 63.8, and for 2 log10 it was 100.8. Moreover, fCmax/MIC for stasis was 5.5, for 1 log10 it was 7.1, and for 2 log10 it was 10.8. We demonstrated that the in vivo concentration-dependent activity of pazufloxacin was effective against the P. aeruginosa infection, and successfully made the PK/PD model sufficiently bactericidal. The PK/PD model will be beneficial in preventing the spread of nosocomial infections.

Novel insight into the vaginal microflora in postmenopausal women under hormone replacement therapy as analyzed by PCR-denaturing gradient gel electrophoresis

OBJECTIVES

A study was conducted to use new molecular technologies to identify the vaginal bacterial species of postmenopausal women under oral estrogen therapy (Premarin-conjugated equine estrogen, CEE).

STUDY DESIGN

Nineteen postmenopausal women under CEE treatment were recruited and their vaginal flora were analyzed during 3 months, using polymerase chain reaction in combination with denaturing gradient gel electrophoresis (DGGE) and sequencing of DNA fragments.

RESULTS

Sixty-eight percent of the women presented with a 'Normal' Nugent score at the first sampling time (d0). All the subjects had bacterial species detected in their vaginal flora. Lactobacillus species were detected in all samples. Moreover, 53% of the women had lactobacilli exclusively at d0. Two Lactobacillus species were dominant, and were recovered from the majority of samples (L. iners and L. crispatus). Forty-four percent of the samples also contained other bacterial species, which were potential urogenital pathogens. Candida albicans was detected in 26% of the subjects. The vaginal flora of the women under CEE treatment were different from that of postmenopausal women not receiving hormone therapy, but very similar to premenopausal women.

CONCLUSIONS

The present study indicates that one benefit from hormone replacement therapy (HRT) is the restoration of a lactobacilli vaginal flora associated with a protective effect against urogenital infections.

In vitro activities of Garenoxacin (BMS 284756) against 108 clinical isolates of Gardnerella vaginalis

Garenoxacin (BMS 284756) was active against 105 of 108 (97%) recent clinical Gardnerella vaginalis isolates at < or =2 micro g/ml by using the reference agar dilution method for anaerobes. Twenty-eight percent of isolates (31 of 108) were resistant to metronidazole, and 44% were resistant to doxycycline. All were susceptible to clindamycin and ampicillin-sulbactam.