Background:

Since the introduction of the fluoroquinolones, ciprofloxacin and ofloxacin over 10 years ago, there has been a small but significant increase in the number of resistant clinical isolates of species previously susceptible to these agents. More recent fluoroquinolones have better activity against Gram-positive species while retaining activity against Gram-negative species. The comparative in vitro activity of the novel fluoroquinolone WCK 1152A was determined against a range of clinical isolates.

Methods:

MICs were determined for 1007 clinical isolates, the majority using the NCCLS agar dilution method. The microbroth method was performed when testing isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis.

Results:

MICs of WCK 1152A, moxifloxacin and ciprofloxacin for respiratory tract pathogens are summarised below. Generally, the in vitro activity of WCK 1152A was similar to that of moxifloxacin. Against isolates of S. pneumoniae of defined genotype, and ‘atypical’ respiratory pathogens, WCK 1152A was some twofold to fourfold more active than moxifloxacin.

Conclusion:

Improved activity against multi-resistant isolates of S. pneumoniae and ‘atypical’ pathogens indicate a potential role for WCK 1152A in the treatment of respiratory tract infections.