Identification of a novel strain of Borrelia hermsii in a previously undescribed northern California focus

An epizootiologic investigation testing for the presence of tick-borne rela psing fever spirochetes in rodent and tick hosts was conducted at Eagle Lak e in Lassen County, California. Six of 211 O. hermsi ticks and none of 180 rodents were polymerase chain reaction (PCR)-positive for Borrelia spiroche tes. Sequencing of the PCR amplified flagellin gene fragment suggests that the spirochetes from Eagle Lake represent a previously undescribed strain o f Borrelia hermsii.