Activity of the investigational fluoroquinolone, finafloxacin and seven other antimicrobial agents against 114 obligately anaerobic bacteria

Abstract number: P1238

Schaumann R., Genzel G.H., Stubbings W., Stingu C.S., Labischinski H., Rodloff A.C.

Objectives: Finafloxacin (FIN) is a novel fluoroquinolone antimicrobial belonging to a 8-cyano subclass and exhibits enhanced activity at slightly acidic pH. FIN is active against a wide range of Gram-positive and Gram-negative aerobes and anaerobes. With the present study, the activity of FIN was tested against 114 recently strains of obligately anaerobic bacteria including reference strains and compared with various other antimicrobials including investigations under acidic conditions.

Methods: The activity of FIN against 73 strains of the Bacteroides fragilis group, 10 other obligately Gram-negative rods and 31 Clostridium difficile strains was tested and compared with the activity of moxifloxacin (MOX), levofloxacin (LEV), ciprofloxacin (CIP), clindamycin (CLI), imipenem (IMP), piperacillin/tazobactam (PIT) and metronidazole (MET). MICs were determined employing the microdilution technique in Wilkens-Chalgren broth supplemented with vitamin K1 and haemin. Furthermore, the MICs of FIN against 11 selected B. fragilis strains, the 10 other Gram-negative rods and 10 selected C. difficile strains were tested under acidic conditions.

Results: The MIC50 and MIC90 values (mg/ml) of the 114 strains tested are listed in the Table.

Under acidic conditions FIN has an increased activity against the selected obligately anaerobes compared to the activity at a neutral pH (data not shown).

Conclusions: FIN has promising activity against several pathogenic species of the B. fragilis group and other Gram-negative rods and is slightly more active than MOX against the obligately anaerobic bacteria tested here. Under acidic conditions FIN is more active against obligately anaerobes compared to the activity under neutral conditions.

Antimicrobial agentB. fragilis group (n = 73)Other obligately Gram-negative rods (n = 10)C. difficile (n = 31)
CIP81611616geqslant R: gt-or-equal, slanted64
CLI18leqslant R: less-than-or-eq, slant0.03geqslant R: gt-or-equal, slanted648geqslant R: gt-or-equal, slanted64
IMP0.250.5leqslant R: less-than-or-eq, slant0.030.0624

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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