Culture of Borrelia persica and its flagellar antigen in vitro.

Borrelia persica is a strain seen only in the Middle East and responsible for relapsing fever. These spirochetes are notable for multiphasic antigenic variation of polymorphic outer membrane lipoproteins, a phenomenon responsible for immune evasion. Diagnosis of the disease is a problem and requires a fixed antigen like the flagellar antigen. In vitro culture of B. persica was carried out for the first time and flagellar antigen was purified from culture. 10% SDS was added to the mixture to dissolve the cell wall and then the solution was sheared in an Omni mixer. Electron microscopy confirmed the purity of a 42 KDa periplasmic antigen as revealed by SDS-PAGE. Indirect haemagglutination kits were designed using the pure flagella and tested for cross reactivity with another relapsing fever spirochaete Borrelia microtii positive serum. The kit showed 98% sensitivity and 95% specificity.

Purification of periplasmic flagellar antigen from Borrelia microtti.

Borrelia microtti and Borrelia persica are 2 Iranian strains of Borrelia found in western Asia and responsible for relapsing fever. The outer surface antigens of Borrelia undergo variations which are responsible for the relapsing phenomenon. The fixed flagellar antigen is required for diagnosis as the variant antigens cannot be used in serological methods of diagnosis. The fixed flagellar antigen was purified for the first time from the Iranian strain of Borrelia microtti using detergent treatment and shearing in an omnimixer. Periplasmic flagella were extracted, as confirmed by electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed a band corresponding to 42 kDa. Indirect haemagglutination kits were designed using the pure flagella and the complete sonicate of Borrelia and showed 98% sensitivity and 95% specificity.