Failure of a short-term antibiotic therapy for human brucellosis using ciprofloxacin. A study on in vitro susceptibility of Brucella strains.
BACKGROUND
Human brucellosis is characterized byfocal complications, chronic courses, and therapeutic failures.


METHODS
In a relapsed case of brucellosis after short-term antibiotic therapy using doxycycline and ciprofloxacin two Brucella strains were isolated, before and after treatment. In vitro susceptibilities of both isolates were determined by E tests including a great variety of antibiotics. In a killing rate experiment the bactericidal activities of doxycycline, streptomycin, rifampin and ciprofloxacin as single agents and in combinations were determined.


RESULTS
Lowest MIC values were measured for doxycycline and ciprofloxacin. MICs did not change under therapy. Streptomycin alone exhibited the most effective killing within 6 h, whereas the other single agents did not show bactericidal activity. Doxycycline plus ciprofloxacin was the most active combination in vitro.


CONCLUSIONS
Routine susceptibility testing of Brucellae is not obligatory as most of the 'traditional' anti-Brucella antibiotics are active in vitro and bactericidal efficacy may differ in vivo.
Al Dahouk
Sascha
S
Department of Bacteriology, Bundeswehr Institute of Microbiology, Munich, Germany. SaschaAlDahouk@bundeswehr.org
Hagen
Ralf M
RM
Nockler
Karsten
K
Tomaso
Herbert
H
Wittig
Martina
M
Scholz
Holger C
HC
Vergnaud
Gilles
G
Neubauer
Heinrich
H
D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002006:Brucellosis / Q000188:drug therapy*; D002939:Ciprofloxacin / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012008:Recurrence; D017211:Treatment Failure
D000890:Anti-Infective Agents; D002939:Ciprofloxacin