DIAGNOSTIC-DETECTION AND DIRECT GENOTYPING OF BORRELIA-BURGDORFERI BYPOLYMERASE-CHAIN-REACTION IN CEREBROSPINAL-FLUID IN LYME NEUROBORRELIOSIS

Background: A DNA target imbalance in favor of the plasmid-borne outer surface protein A (OspA) versus chromosomal genes has been thought to explain the relatively high diagnostic sensitivity of an OspA-based p olymerase chain reaction (PCR) on joint fluid from patients with Lyme arthritis. The aim of this study was to evaluate the diagnostic sensit ivity of the OspA-based PCR on cerebrospinal fluid (CSF) samples from patients with Lyme neuroborreliosis and to perform DNA sequence analys is on the amplicon to determine the genospecies of Borrelia present in the CSF. Methods and Results: CSF from 150 consecutively diagnosed Eu ropean patients with untreated active neuroborreliosis was investigate d. Borrelia burgdorferi DNA was detected in 31 of 150 patients with Ly me neuroborreliosis (20.6%). Genotyping of the amplicons was possible in 13 of the CSF samples and revealed that 11 of the 13 patients had b een infected with Borrelia garinii, 1 with Borrelia afzelii, and 1 spe cimen showed evidence of a mixture of B. garinii and B. afzelii sequen ces. Conclusions: The diagnostic sensitivity of the OspA-based PCR for detection of B. burgdorferi DNA in CSF was comparable to that found p reviously using PCR assays based on genomic targets. The predominance of B. garinii DNA (92%) found in CSF substantially supports the curren t hypothesis that B. garinii is the principal agent of Lyme neuroborre liosis in Europe. Mixed infections, comprising different genospecies o f B. burgdorferi sensu late, seem to be the exception.