Studies to improve the ability of culture medium to recover Borrelia miyamotoi

Abstract

The relapsing fever spirochete Borrelia miyamotoi was recently detected in hard-bodied Ixodes scapularis ticks that also transmit Lyme disease-causing B. burgdorferi. As a result, methods of laboratory diagnosis that rely on detecting specific antibody responses are likely confounded as the spirochetes share similar proteins. Efforts to better understand this possibility have been hampered due to the absence of a medium capable of recovering B. miyamotoi from a human who contracted the illness in the United States. In this study, MKP-F culture medium typically used to cultivate a laboratory-acclimated B. miyamotoi isolate was significantly improved by eliminating gelatin and adding 10% human serum (MKP-H). However, the increased efficacy was not sufficient to recover the spirochetes from a patient who contracted the spirochetes. In a preliminary experiment, it was also confirmed that patients infected with B. miyamotoi produce antibodies that react commonly with multiple B. burgdorferi proteins, including the C6 peptide thought to be highly specific for Lyme disease spirochetes, which highlights the necessity of continued effort to improve the efficacy of laboratory culture medium sufficient to recover B. miyamotoi spirochetes from local patients.