Comparison of in vitro antibacterial activity of levofloxacin and ciprofloxacin

ABSTRACT

Levofloxacin and ciprofloxacin are widely used antibiotics that belong to the class of fluoroquinolones. The in vitro antibacterial activity of these two antimicrobials were evaluated and compared in the present study by Disk Diffusion [Kirby-Bauer] method against 52 clinical isolates of Staphylococcus aureus [n = 36] and Klebsiella pneumoniae [n = 16]. These clinical isolates were obtained from different pathological laboratories and medical centers of Karachi. Among clinical isolates of Staphylococcus aureus the average zone of inhibition for levofloxacin was 16.7 mm while for ciprofloxacin the zone of inhibition was 21 mm. For the clinical isolates of Klebseilla pneumoniae the average zone of inhibition of levofloxacin was 16.5 mm while for ciprofloxacin was 16.9 mm. Comparison of susceptibility results indicated that both fluoroquinolones have excellent in vitro antibacterial activity but comparatively ciprofloxacin showed broader spectrum of activity against most of the tested clinical isolates