D. Jonas et al., Efficacy of moxifloxacin, trovafloxacin, clinafloxacin and levofloxacin against intracellular Legionella pneumophila, J ANTIMICRO, 47(2), 2001, pp. 147-152
This study compares the in vitro activity of novel fluoroquinolones against
clinical Legionella pneumophila isolates. We determined both the MICs and
intracellular efficacy of moxifloxacin, trovafloxacin, clinafloxacin and le
vofloxacin in the Mono Mac 6 infection model. Six legionella strains were t
ested and all proved highly susceptible to the fluoroquinolones. Clinafloxa
cin and trovafloxacin were found to have the lowest MICs (0.004 mg/L) follo
wed by levofloxacin and moxifloxacin (0.015-0.03 mg/L). In the Mono Mac 6 i
nfection model, inhibition of L. pneumophila was achieved at concentrations
four times below the respective in vitro MICs. Concentrations as low as 0.
015 mg/L of moxifloxacin and levofloxacin, 0.004 mg/L of trovafloxacin and
0.002 mg/L of clinafloxacin markedly decreased viable intracellular bacteri
al counts. These data strongly support further clinical evaluation of new f
luoroquinolones for empirical treatment of lower respiratory tract infectio
n including atypical pneumonia caused by L. pneumophila.