In vitro activity and selection of disk content for disk diffusion susceptibility tests with trovafloxacin

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• The emergence of antibiotic resistance necessitates the development of novel antimicrobial agents.
• Fluoroquinolones are a class of broad-spectrum antibiotics with significant clinical utility.
• Trovafloxacin represents a new generation fluoroquinolone with potential for enhanced antimicrobial activity.

Purpose of the Study:

• To evaluate the in vitro antimicrobial activity of trovafloxacin.
• To compare trovafloxacin's efficacy against ciprofloxacin and ofloxacin.
• To assess trovafloxacin against a diverse range of bacterial pathogens, including anaerobic and Gram-positive species.

Main Methods:

• In vitro susceptibility testing of 517 bacterial isolates from 50 species.
• Comparative analysis of trovafloxacin, ciprofloxacin, and ofloxacin activity.
• Disk diffusion testing for trovafloxacin using 10 microgram disks.

Main Results:

• All three fluoroquinolones exhibited good in vitro activity against Enterobacteriaceae.
• Trovafloxacin displayed significantly enhanced activity (4- to 16-fold greater) against anaerobic bacteria, Staphylococcus, Streptococcus, and Enterococcus species compared to ciprofloxacin.
• Satisfactory results were obtained using 10 microgram trovafloxacin disks in disk diffusion testing.

Conclusions:

• Trovafloxacin exhibits potent in vitro activity, particularly against challenging anaerobic and Gram-positive bacterial pathogens.
• The findings support the potential clinical utility of trovafloxacin as a novel therapeutic option.
• Tentative criteria for clinical studies using trovafloxacin disk diffusion testing are proposed.