HETEROGENEITY OF BMPA (P39) AMONG EUROPEAN ISOLATES OF BORRELIA-BURGDORFERI SENSU-LATO AND INFLUENCE OF INTERSPECIES VARIABILITY ON SERODIAGNOSIS

The molecular and antigenic variabilities of BmpA (P39) among European isolates of Borrelia burgdorferi mere analyzed, The bmpA sequences of 12 isolates representing all three species of B. burgdorferi sensu la to pathogenic for humans mere amplified by PCR, cloned, and sequenced, The BmpA protein of Borrelia garinii is heterogeneous, with an amino acid sequence identity ranging from 91 to 97%, whereas the BmpA protei ns of Borrelia afzelii and B. burgdorferi sensu stricto strains appear to be highly conserved (> 98.5% intraspecies identity), The interspec ies identities ranged from 86 to 92%, Cluster analysis of BmpA reflect ed the subdivision of B. burgdorferi sensu lato isolates into the thre e species as well as a considerable heterogeneity among B. garinii str ains. The BmpA protein of each species of B. burgdorferi sensu lato wa s recombinantly expressed in Escherichia coli, purified, and used to g enerate monoclonal antibodies, Seven BmpA-specific antibodies were ide ntified; six of them recognized conserved epitopes of all three specie s, whereas one was specific for BmpA of B. afzelii and B. garinii. A m onoclonal antibody (H1141) recommended by the Centers for Disease Cont rol and Prevention for use in the standardization of immunoblots showe d strong reactivity with BmpA of B. burgdorferi sensu stricto but no o r only weak reactivity with BmpA of B. garinii and B. afzelii, respect ively, Sera from 86 European patients with Lyme borreliosis in differe nt stages and 73 controls mere tested in immunoglobulin G (IgG) and Ig M immunoblots with the recombinant BmpA proteins of the three species, revealing specificities of 98.5 to 100% IgM antibodies against recomb inant BmpA were only rarely detected (1.1 to 8.1%), With the BmpA prot eins of B. afzelii and B. garinii, sensitivities far the IgG test (ser a from stages I to III) were 36.0 and 34.9%, respectively, in contrast to 13.9% with BmpA of B. burgdorferi sensu stricto. Therefore, we rec ommend that recombinant BmpA of B. afzelii or B. garinii should be use d solely, or in addition to B. burgdorferi sensu stricto BmpA, in sero diagnostic tests for Lyme borreliosis in Europe.