In vitro antibiotic susceptibility of Francisella tularensis isolated from humans and animals

• Published in: Journal of antimicrobial chemotherapy 2000-08, Vol.46 (2), p.287-290
• Main Authors: Ikäheimo, I., Syrjälä, H., Karhukorpi, J., Schildt, R., Koskela, M.
• Format: Article
• Language: English
• Subjects: Animals; Animals, Wild - microbiology; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Arvicolinae; Biological and medical sciences; DNA, Bacterial - analysis; DNA, Bacterial - isolation & purification; Electrophoresis, Polyacrylamide Gel; Francisella tularensis; Francisella tularensis - drug effects; Humans; Medical sciences; Microbial Sensitivity Tests; Pharmacology. Drug treatments; Rabbits; Reverse Transcriptase Polymerase Chain Reaction; Tularemia - microbiology
• ISSN: 0305-7453; 1460-2091; 1460-2091
• DOI: 10.1093/jac/46.2.287

The in vitro susceptibility of 38 strains of Francisella tularensis (biovar F. tularensis palaearctica) was determined using Etests on cysteine heart agar plates with 2% haemoglobin. All strains were susceptible to the antibiotics traditionally used to treat tularaemia, such as streptomycin (MIC90 4.0 mg/L), tetracycline (MIC90 0.38 mg/L) and chloramphenicol (MIC90 0.38 mg/L), and to aminoglycosides, such as tobramycin (MIC90 1.5 mg/L) and gentamicin (MIC90 1.0 mg/L). The quinolones examined had low MIC90s: ciprofloxacin, 0.016 mg/L; levofloxacin, 0.016 mg/L; grepafloxacin, 0.047 mg/L; and trovafloxacin, 0.032 mg/L. In contrast, all the strains were resistant to β-lactams and azithromycin. Quinolones thus seem to be promising drugs for the treatment of tularaemia.