Oligonucleotide primers based on Borrelia burgdorferi sensu lato ospA gene sequences have been designed for use in the PCR to type all (SL primers) or each (GI to GIII primers) of the B. burgdorferi sensu lato genospecies involved in
Lyme disease. These genospecies-specific primers were then used in the PCR on 24 biological fluids collected from 18 neuroborreliosis patients. Among the samples tested, 20 contained DNA from Borrelia garinii, 11 contained DNA from B. burgdorferi sensu stricto, and 10 contained DNA from Borrelia afzelii. In toto, 10 patients appeared to have been infected by a single genospecies and 8 were infected by more than one
Lyme disease-associated genospecies. Serum specimens from six patients were absorbed with heterologous antigens and tested by Western blotting (immunoblotting). In four cases, residual immunodetection revealed specific epitopes of genospecies also detected by PCR; in two of them, the concordant results indicated pluri-infection of the patients. In the other two cases, Western blotting showed specific antibodies for two genospecies of Borrelia, while PCR detected DNA from only one. In summary, the data underscored the relatively high prevalence of pluri-infections in
Lyme disease and confirmed the association of B. garinii with neuroborreliosis.