NONDIFFERENTIATION BETWEEN LYME-DISEASE SPIROCHETES FROM VECTOR TICKSAND HUMAN CEREBROSPINAL-FLUID

To determine whether Lyme disease neuropathogenesis may result from in fection by a particular segment of the locally extant population of sp irochetes, genetic markers of spirochetes found in cerebrospinal fluid (CSF) of 12 pediatric patients were compared with those in spirochete s from 40 vector ticks sampled in the vicinity of their homes. The pri mary structure of the outer surface protein A served as the marker of variation; a fragment of the corresponding gene was amplified by neste d polymerase chain reaction and the products sequenced, Tick-derived v ariants clustered in seven distinct categories, of which four were pre sent in CSF. One of the CSF variants differed from any found in ticks, Coinfection by different spirochete variants was infrequent in ticks and absent in human samples, Spirochetal neuropathology in children in our study site does not correlate with a particular segment of the ti ckborne pathogens present in nature.