Comparative activity of new quinolones against 326 clinical isolates of Stenotrophomonas maltophilia

Abstract

Stenotrophomonas maltophilia is an important emerging pathogen causing a variety of infections in severely ill patients. This microorganism is inherently resistant to many antibiotics, and only a few therapeutic options are available. The principal aim of this study was to assess the in vitro activity of new quinolones against this pathogen. Three hundred and twenty-six single clinical isolates were tested in this study. The MIC(90) was 16 mg/L for ciprofloxacin, 8 mg/L for levofloxacin and gatifloxacin, 4 mg/L for trovafloxacin, moxifloxacin and sparfloxacin and 2 mg/L for clinafloxacin. At a 2 mg/L concentration, a C(max) lung:MIC ratio of >/=10 can be reached for 95%, 84.3%, 83.1% and 81.5% of isolates, respectively, for clinafloxacin, trovafloxacin, moxifloxacin and sparfloxacin (P < 0. 001 compared with levofloxacin and ciprofloxacin). In spite of the rare but serious adverse events associated with the new-generation quinolones, these agents may become very useful in the treatment of certain severe or life-threatening infectious conditions due to S. maltophilia, notably lower respiratory tract infections.

Activities of Ciprofloxacin and Moxifloxacin against Stenotrophomonas maltophilia and Emergence of Resistant Mutants in an In Vitro Pharmacokinetic-Pharmacodynamic Model

“…Newer fluoroquinolones, such as moxifloxacin, appear to be more active against S. maltophilia than the older agents of this family (28,37). Moreover, the development of resistance has been shown to be less pronounced with moxifloxacin than with ciprofloxacin in Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae (7,12,29).…”

In Vitro Killing Effect of Moxifloxacin on Clinical Isolates of Stenotrophomonas maltophilia Resistant to Trimethoprim-Sulfamethoxazole

“…Trimethoprimsulfamethoxazole is considered the treatment of choice (2), but resistant isolates emerge (8). Although newer fluoroquinolones have been shown to possess a considerable in vitro inhibitory effect on that species (3,10), studies involved only isolates susceptible to co-trimoxazole. The present study focused on the in vitro killing effect of moxifloxacin on genetically distinct isolates of S. maltophilia resistant to co-trimoxazole.…”

Acral necrosis by Stenotrophomonas maltophilia

“…New generation quinolones (trovafloxacin, clinafloxacin, moxifloxacin, sparfloxacin) have an enhanced in vitro activity against SM and could become an alternative if clinical studies confirm these results. 15 Some authors refer to the synergistic effect of a combination of antimicrobial agents. 1,16 Despite the fact that SM has been considered to be a nosocomially acquired pathogen, community acquired infection with this bacterium may occur more frequently than previously recognized.…”