rifampin and Tularemia

Tularemia is a rare zoonosis. The most common way is ingestion of contaminated meat or water, but the infection may also be acquired by insect bite. The clinical picture of the disease may be nonspecific. Due to polymorphisms of clinical picture, specific treatment is often delayed. In the last 50 years, in Poland, the most infections were acquired by handling hares. In our article, we present the case of a patient who was infected with Francisella tularensis due to arthropod bite. In the presented case, the diagnosis was difficult, because of the nonspecific clinical picture. Information of the epidemiology and the clinical picture changes of tularemia may have great clinical significance. Tularemia requires the special attention of physicians. All patients with lymphadenopathy and arthropod bite history should be screened for tularemia in the outpatient department and, if necessary, treated in hospital.

Topics: Adult; Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Arthropod Vectors; Bites and Stings; Ceftriaxone; Fever; Francisella tularensis; Humans; Lymphatic Diseases; Male; Poland; Rifampin; Streptomycin; Treatment Outcome; Tularemia; Zoonoses

The antibiotic susceptibilities of 50 Francisella tularensis subsp. holarctica biovar II strains isolated from hares and human patients from the eastern part of Austria were examined. Minimum inhibitory concentrations (MICs) of 24 antimicrobial agents were determined using Eteststrade mark on cysteine heart agar plates supplemented with 10% sheep blood. All isolates were sensitive to tetracyclines, aminoglycosides, quinolones, chloramphenicol and rifampicin. Resistance was observed in all isolates against macrolides, penicillins and aztreonam. Bacteria were resistant to cephalosporins and carbapenems, except for 8% of strains investigated that were susceptible or intermediately susceptible. Our in vitro susceptibility data can be applied for the detection and comparison of resistance development and to provide in vitro data for the guidance of therapy.

Topics: Aminoglycosides; Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Austria; Carbapenems; Cephalosporins; Chloramphenicol; Francisella tularensis; Hares; Humans; Microbial Sensitivity Tests; Quinolones; Rifampin; Tetracycline; Tularemia

The protective effects of doxycycline, rifampicin and sisomicin were compared in a multifactor experiment with animal infection induced by finally dispersed aerosol of a virulent strain of the European variant of the tularemia causative agent and the optimal regimens for the antibiotic use were determined. By the values of the protective effect rifampicin and sisomicin were shown to provide a high percentage of the animal survival: more than 80 and up to 50-70 per cent of the animals survived when the aerosol infective doses were 100 and 10,000 LD50, respectively. A characteristic feature of doxycycline was its activity only in the infection induced by low doses of the biological agent. The optimal course of the antibiotic therapy in inhalation tularemia was 6 to 8 days. The interval of 1 to 3 days between the infection and the therapy start had no significant effect on the protective efficacies of the antibiotics.

Topics: Administration, Inhalation; Aerosols; Animals; Anti-Bacterial Agents; Antibiotics, Antitubercular; Dose-Response Relationship, Drug; Doxycycline; Mice; Rifampin; Sisomicin; Tularemia

Under natural conditions, the Francisella tularensis strains AE-261 and P-13864 capable of forming the persist type of resistance to antibacterial drugs and being the cause of the infection in laboratory animals not responding to monotherapy with antibiotics were detectable. The antibioticograms of strains AE-261 and P-13864 under the in vitro conditions did not differ from those of the other studied strains responding to the antibiotic therapy. The observed phenomenon could be associated with individual peculiarities of the strains and their phenotypic variation in the host. Combinations of aminoglycoside antibiotics (streptomycin, gentamicin and amikacin) with rifampicin were shown to be highly active in the treatment of general forms of the infection due to such strains. The combined therapy of tularemia was also considered promising because of its high efficacy when the treatment was started at late periods as well as because unlike the monotherapy with the aminoglycoside antibiotics it provided complete elimination of the pathogen from the host.

Topics: Aminoglycosides; Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Drug Therapy, Combination; Francisella tularensis; Guinea Pigs; Mice; Phenotype; Rabbits; Rifampin; Time Factors; Tularemia