Antimicrobial susceptibility of Francisella tularensis subsp. holarctica strains from Hungary, Central Europe.
OBJECTIVE
Determining the in vitro susceptibility to 11 antibiotics of Francisella tularensis subsp. holarctica strains belonging to the phylogenetic group B.13, from different areas of Hungary.


METHODS
Twenty-nine F. tularensis strains isolated between 2003 and 2010 from free-ranging European brown hares (Lepus europaeus) and a captive patas monkey (Erythrocebus patas) were collected from different parts of Hungary and examined for antibiotic susceptibility with commercially available MIC test strips on modified Francis agar plates; values were interpreted according to CLSI breakpoints.


RESULTS
The strains were susceptible to aminoglycosides (MIC(90) values: gentamicin, 0.75 mg/L; and streptomycin, 6.0 mg/L), tetracyclines (MIC(90) values: tetracycline, 0.5 mg/L; and doxycycline, 1.0 mg/L), quinolones (MIC(90) values: ciprofloxacin, 0.047 mg/L; and levofloxacin, 0.023 mg/L) and chloramphenicol (MIC(90) value: 1.5 mg/L), i.e. antibiotics commonly used in therapy. Tigecycline (MIC(90) value: 0.19 mg/L) and rifampicin (MIC(90) value: 1.0 mg/L) were also active against F. tularensis strains, while resistance to erythromycin (MIC(90) value: >256 mg/L) and linezolid (MIC(90) value: 32 mg/L) was observed in all strains.


CONCLUSIONS
Based on the results, quinolones are recommended as first choice therapy for F. tularensis infection. The in vitro susceptibility of the strains to tigecycline may encourage the application of this antibiotic as well. The similar antibiotic susceptibilities of the Hungarian strains belonging to different subclades of phylogenetic group B.13 indicates that strains from other Central and Eastern European countries belonging to this group might also have the same susceptibility profile.
Institute for Veterinary Medical Research, Centre for Agricultural Research,  Hungarian Academy of Sciences, Hungária körút 21, H-1143 Budapest,  Hungary.
Zsuzsa
Z
Kreizinger
László
L
Makrai
Georgina
G
Helyes
Tibor
T
Magyar
Károly
K
Erdélyi
Miklós
M
Gyuranecz
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004901:Erythrocebus patas / Q000382:microbiology*; D005604:Francisella tularensis / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D034621:Hares / Q000382:microbiology*; D006814:Hungary; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing
D000900:Anti-Bacterial Agents