New BB0108, BB0126, BB0298, BB0323, and BB0689 Chromosomally Encoded Recombinant Proteins of sensu lato for Serodiagnosis of Lyme Disease.

Five chromosomally encoded proteins, BB0108, BB0126, BB0298, BB0323, and BB0689, from sensu lato (s.l.), were obtained in three variants each, representing the most common genospecies found in Europe (, sensu stricto (s.s.), and ). The reactivity of these recombinant proteins with the IgM and IgG antibodies present in human serum was assessed using Western blot (WB) and the ELISA. In IgG-WB, the proteins exhibited varying reactivity, peaking at approximately 40-50% for BB0108 and BB0689. However, none of these proteins were recognized by specific antibodies in the IgM-WB. The sensitivity of IgG-ELISA based on three variants of BB0108 and BB0323 ranged from 71% to 82% and from 62% to 72%, respectively. Conversely, the specificity of both tested proteins was consistently above 82%. Tests utilizing single variants of BB0323 did not yield any diagnostic value in detecting IgM antibodies. However, BB0108 demonstrated recognition by antibodies present in 52% to 63% of the tested sera. These antigens appear advantageous due to the consistent reactivity observed across their variants. This observation suggests that appropriate selection of antigens conserved within s.l. could offer a solution to the issue of variable sensitivity encountered in serodiagnostic tests across Europe.