Efficacy of minocycline and tigecycline in a hamster model of leptospirosis.

Leptospirosis is a widespread zoonotic infection characterized by acute febrile illness. Severely ill patients may require empiric treatment with broad-spectrum antibiotics prior to definitive diagnosis. We evaluated the efficacy of minocycline and tigecycline against leptospirosis in a hamster model. Hamsters were treated with either minocycline (5, 10, or 25 mg/kg per day) or tigecycline (5, 10, or 25 mg/kg per day) for 5 days. Controls included untreated animals and doxycycline-treated animals (5 mg/kg per day). Nine days after infection, all untreated animals were dead. All treated hamsters survived to the end of study (day 21). Study groups showed significantly improved survival compared to the untreated group (P < .01). Minocycline and tigecycline showed survival benefit comparable to the standard treatment, doxycycline. In the absence of doxycycline, minocycline may be considered as an alternative, while tigecycline may be useful in the management of severely ill patients prior to a definitive diagnosis.