In vitro antibacterial activity of chinfloxacin, a new fluoroquinolone antibiotic.
BACKGROUND
Chinfloxacin is a novel synthetic fluoroquinolone with a structure similar to moxifloxacin. The in vitro activity of chinfloxacin was evaluated in the current study.


METHODS
Chinfloxacin was tested against a total of 1,739 clinical isolates representing 23 species using the agar dilution method. Studies of bactericidal activity, including minimum bactericidal concentrations (MBC) and time-kill curve determinations, were conducted according to the recommendations of the Clinical and Laboratory Standards Institute.


RESULTS
Minimum inhibitory concentrations (MIC)(50)s and MIC(90)s of chinfloxacin were found to be the same or 2-fold lower than those of moxifloxacin against gram-positive isolates except for Streptococcus pyogenes (against which chinfloxacin showed similar MIC(50) as moxifloxacin but 2-fold higher MIC(90)), and the same as or 2-fold higher than those of moxifloxacin against gram-negative isolates. Chinfloxacin showed potent bactericidal activity with MBC/MIC ratios in the range of 1-2 for almost all the isolates tested. Time-kill curves further demonstrated chinfloxacin as a concentration-dependent bactericidal agent usually effective at concentrations of 2 MIC or higher.


CONCLUSIONS
Chinfloxacin showed similar in vitro activity as moxifloxacin.
Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
Guo-Qing
GQ
Li
Min
M
Yuan
Xin-Yi
XY
Yang
Cong-Ran
CR
Li
Xin-Xin
XX
Hu
Wei-Xin
WX
Zhang
Ren-Hui
RH
Lou
Hui-Yuan
HY
Guo
Xuan-Wang
XW
You
Shan
S
Cen
Jian-Dong
JD
Jiang
Xue-Fu
XF
You
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D024841:Fluoroquinolones / Q000737:chemistry / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D013297:Streptococcus pyogenes / Q000187:drug effects
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; C577146:chinfloxacin