The in vitro and in vivo susceptibilities of the Lyme disease pathogen Borrelia burgdorferi to cefuroxime were compared with those of several other antibiotics commonly used to treat this disease. Cefuroxime demonstrated a higher MBC in vitro (1.0 ,ug/ml) than ceftriaxone (0.08 ,Ig/ml) or erythromycin (0.32 ,ug/ml), but the MBC was similar to that of amoxicillin (0.8 ,ug/ml) and doxycycline (1.6 ,ig/ml). B. burgdorferi was considerably less susceptible to tetracycline (3.2 ,ug/mI) and penicillin G (6.4 ,ug/ml). Of the three other Borrelia species tested, two (Borrelia turicatae and Borrelia anserina) also demonstrated susceptibility to cefuroxime, while the third (Borrelia hernsii) was less susceptible. Results obtained with four antimicrobial agents in the in vivo hamster model parallel the antibiotic susceptibilities in the in vitro study. The three antibiotics with similar MBCs in vitro, i.e., cefuroxime, doxycycline, and amoxicillin, demonstrated comparable activities in preventing borreliosis in B. burgdorferi-chalHenged hamsters (50% curative doses = 28.6, 36.5 and 45.0 mg/kg, respectively). Penicillin G, which demonstrated the highest MBC in vitro, had very weak protective activity in the hamster model system. These results indicate that the in vitro and in vivo activities of cefuroxime against B.

Current diagnostic tests for Lyme disease (LD) are dependent upon the host serologic response and are insensitive early in infection and, possibly, following antibiotic therapy. We cloned a library of Borrelia burgdorferi 297 DNA and studied one clone, Ly-1, for its potential in diagnostic and pathogenic studies. Using pulsed-field electrophoresis, we demonstrated that Ly-1 is of chromosomal origin and estimated that the B. burgdorferi chromosome is approximately 1,100 kb in size. The 3.7-kb Ly-1 clone hybridizes with geographically diverse strains of B. burgdorferi. No cross hybridization occurs with DNA from human cells, Escherichia coli, Staphylococcus aureus, Clostridium difficile, or the closely related B. hermsii. We used a dot blot assay to detect 100 pg of B. burgdorferi DNA. We partially determined the nucleotide sequence of Ly-1 and used it to select and synthesize oligonucleotides for use in the polymerase chain reaction (PCR). Two different primer pairs were found to amplify DNA from nine geographically diverse isolates. We could detect 10 fg (<10 molecules) of B. burgdorferi or less than five spirochetes added to human urine. Finally, we were able to use the PCR to detect B. burgdorferi DNA in the urine of four of eight patients with suspected active LD (three with arthritis and one with neurologic manifestations), all of whom responded to antibiotic treatment. In contrast, those patients who were PCR negative either had inactive disease or had been appropriately treated and did not respond to additional antibiotics, and all four control urine specimens were PCR negative. We conclude that B. burgdorferi DNA can be sensitively detected by the PCR with the primers and methods we describe and that the urinary tract is a site of persistent infection in some cases of human LD, an observation of potential diagnostic and pathogenic importance. * Corresponding author. specificity of the Ly-1 DNA clone, part of its nucleotide sequence, its use in the polymerase chain reaction (PCR) to detect <10 DNA copies or less than five organisms in human urine in laboratory reconstructions and, for the first time, the detection of B. burgdorferi DNA in the urine of patients with LD. (This research was presented in part at the meeting MATERIALS AND METHODS Culture methods and strains. B. burgdorferi and B. hermsii strains were grown to maximal densities in BSK II medium (1). Organisms were enumerated by dark-field microscopy with a Petroff-Hausser chamber. The origins of the B. burgdorferi strains were as follows: 297, human cerebrospinal fluid, Conn.; 10293, avian, Conn.; 20047, Ixodes ricinus, France; IPT, I. pacificus, Calif.; P/GU, human skin, Munich, Federal Republic of Germany; MM1, mouse, Minn.; NCH-1, human skin, Wis.; K48, I. ricinus, Czechoslovakia; G25, I. ricinus, Sweden; and CT-2, I. dammini, Wis. The B. hermsii strain used was from the tick Ornithodoros hermsi in the western United States (HS1, ATCC 35209).Cloning of Ly-l. Early-passage B. burgdorferi 297 was grown to a maximal density, and the cells were wa...

The heart can be severely affected in humans with Lyme disease, causing conduction defects and, rarely, heart failure. Although immunodeficient and young mice may develop cardiac lesions, cultivation of Borrelia burgdorferi from cardiac tissues of experimentally infected animals has not been reported previously. We infected Syrian hamsters with B. burgdorferi 297 and found a marked tropism of the spirochete for myocardial and urinary tract tissues. Fifty-six of 57 hearts (98%) and 52 of 58 bladders (90%) were culture positive. The cardiac infection was persistent and could be documented in 21 of 22 hearts (96%) cultured from days 28 to 84 postinfection. The urinary tract was also a site of persistent infection in most animals, with 18 of 23 bladders (78%) being culture positive from days 28 to 84. The persistence of spirochetes was specific for the heart and bladder, as indicated by negative cultures of specimens from the liver and spleen, in which only 1 of 23 cultures was positive from days 28 to 84. Because of the high isolation rates, tropism, and persistence that we found for B. burgdorferi in the hamster heart and bladder, these sites will be useful and important for the cultivation of spirochetes in experimental studies that evaluate the efficacies both of candidate vaccines in preventing infection and of antibiotics in eradicating organisms from privileged sites. In addition, the clear demonstration of persistent cardiac infection with B. burgdorferi may provide a useful model for studying the pathogenesis of cardiac Lyme disease.