title: In vitro and in vivo susceptibility of the Lyme disease spirochete, Borrelia burgdorferi, to four antimicrobial agents.
abstract: The antimicrobial susceptibility of Borrelia burgdorferi isolated from human spinal fluid was determined in vitro and in vivo. A broth dilution technique was used to determine the MBCs of four antimicrobial agents. The Lyme disease spirochete was most susceptible to ceftriaxone (MBC, 0.04 microgram/ml) and erythromycin (MBC, 0.05 microgram/ml), then tetracycline (MBC, 0.8 microgram/ml), and finally penicillin G (MBC, 6.4 micrograms/ml). Syrian hamsters were used to determine the 50% curative doses (CD50s) of the four antimicrobial agents. Ceftriaxone and tetracycline had the highest activities, with CD50s of 24.0 and 28.7 mg/kg [corrected], respectively. Both erythromycin and penicillin G possessed low activities. The CD50 of erythromycin was 235.3 mg/kg [corrected], and the CD50 of penicillin G was greater than 197.5 mg/kg [corrected].
mesh_terms: D000818:Animals; D001898:Borrelia / Q000187:drug effects*; D025065:Borrelia burgdorferi; D002443:Ceftriaxone / Q000494:pharmacology* / Q000627:therapeutic use; D006224:Cricetinae; D004917:Erythromycin / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008193:Lyme Disease / Q000188:drug therapy / Q000382:microbiology; D008647:Mesocricetus; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000494:pharmacology* / Q000627:therapeutic use; D013752:Tetracycline / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D004917:Erythromycin; D002443:Ceftriaxone; D013752:Tetracycline; D010400:Penicillin G