Specificities and sensitivities of four monoclonal antibodies for typing of Borrelia burgdorferi sensu lato isolates

Borrelia burgdorferi, the agent of Lyme borreliosis, is genetically more he terogeneous than previously thought. In Europe five genospecies have been d escribed from the original B. burgdorferi sensu late (sl): B. burgdorferi s ensu stricto (ss), B. garinii, B. afzelii, B. lusitaniae, and B. valaisiana . In the United States, B. burgdorferi ss as well as B. bissettii in Califo rnia and B. andersonii on the East Coast were differentiated. In Asia, B. j aponica has been identified along, with B. garinii, B. afzelii, and B. vala isiana. In order to evaluate sensitivity and specificity of four species-sp ecific monoclonal antibodies, we analyzed 210 B. burgdorferi sl isolates be longing to eight genospecies by immunoblot and confirmed genospecies by res triction fragment length polymorphism (RFLP) of rrf (5S)-rrl (23S) intergen ic spacer amplicon, Monoclonal antibody H3TS had 100% sensitivity for 55 B. burgdorferi ss isolates but showed reactivity with all four isolates belon ging to B. bissetii. Monoclonal antibody I 17.3 showed 100% specificity and sensitivity for 45 B. afzelii isolates. Monoclonal antibody D6 was 100% sp ecific for B. garinii but missed 1 of 64 isolates (98.5% sensitivity), Mono clonal antibody A116k was 100% specific for B. valaisiana but was unreactiv e with 4 of 24 isolates (83.5% sensitivity). Genetic analysis correlated we ll with results of reactivity and confirmed efficacy of the phenotypic typi ng of these antibodies. Some isolates showed atypical RFLP. Therefore, both phenotypic and genotypic analyses are needed to characterize new Borrelia isolates.