[Immunodiagnostic tests aimed at discovering infections in dogs caused by Borrelia burgdorferi sensu lato and the assessment of the epizootiological situation. [Doctoral dissertation]] | Imunodijagnostički testovi u otkrivanju infekcija pasa izazvanih sa Borrelia burgdorferi sensu lato i procena epizootiološke situacije. Doktorska disertacija

Lyme borreliosis (LM) is an infectious, multisystemic disease of humans and certain animal species caused by spirochetes of the Borrelia burgdorferi sensu lato complex. Previous investiagtions have revealed that dogs represent competent reservoirs of B. burgdorferi sensu lato. Therefore, assaying the seroprevalence in dogs is a useful tool in establishing endemic areas of Lyme borreliosis. This doctoral thesis deals with examining the seroprevalence of dogs in the Belgrade area with home made IIF, iELISA and the Western blot test. The strain antigens were prepared using three species, B. burgdorferi sensu stricto, B. afzelii and B. garinii. Positive serum was obtained through immunization of dogs by two protocols of immunization: intravenous application of inactivated whole cell culture of borrelia and subcutaneous application of sonicated borrelia (B. burgdorferi s.s.). The IIF, ELISA and the Western blot assay confirmed that the dogs immunized by the two protocols exhibited differences in time appearance and avidity of IgG antibodies. The Western blot determined that avidity of IgG antibodies was the highest in OspA, OspB and p17, of B. burgdorferi s.s. and B. afzelii, no matter which immunization protocol had been used. Assaying of the 215 dogs blood sera originating from four different groups of dogs:1. hunting dogs (n=41), 2. stray dogs (n=125), 3. home dogs with symptoms that indicate infection with B. burgdorferi and 4. home, clinically healthy dogs (n=15) by IIF, ELISA and the Western blot test, has for the first time revealed the presence of dogs infected by B. burgdorferi s.l. in the Belgrade area. The established seroprevalence was 24.7%, and the highest level was found in the stray dog group (31.2%). It was found that the antibodies reactivity at p39, p58, p17 and p83/100 in immunoblot with B. burgdorferi s.s., and at p30, p39, p58, p14, p83/100 and p21 in immunoblot with B. afzelii indicated that dogs were naturally infected by B. burgdorferi s.l. A comparative analysis of immunoblot results with B. burgdorferi s.s. and B. afzelii revealed the congruence of 93.2%. Using the immunoblot as a standard test, it was established that the calculated IIF sensitivity was 67.9% and specificity 92.6%, and the ELISA test sensitivity and specificity were 94.4% and 84.9%, respectively. Testing of the dog sera reactivity at 7 serovars of L. interrogans by microscopic agglutination test did not find that the results of home made tests were influenced by cross reactive antibodies. The results of B. burgdorferi s.l. seroprevalence in the Belgrade area dogs are in accordance with the percentage of tick infection with B. burgdorferi s.l., which leads us to the conclusion that serological assaying of dogs represents a useful tool in determining endemic areas.