Expression Of Babesia Microti Truncated Secreted Antigen And Epidemiology Research Of Two Kinds Of Tick-borne Diseases

The tick can transmit various kinds of pathogens of human and animals,including Babesia microti and Borrelia burgdorferi etc. In recent years, tick-bronediseases are spreading, which not on3ly leads to serious lost on the economic, but alsothreaten the people’s health. The serology investigation will facilitate the effectiveprevention and the treatment of these diseases. As a new pathogen, B.microti isdifficult to be diagnosed. In order to establish an effective diagnosis method. weselected a truncated fragment of Babesia microti secreted antigen1(BmSA1), as adiagnosing antigen to establish B.microti ELISA method. The fragment from72bp to762bp in the full length of BmSA1gene, which encoding a228amino acids betweenN-terminal signal peptide and C-terminal cross membrane area was selected as targetfragment through the biological information analysis, to be ligated into pGEX-4T-1expression vectorand to construct recombinant plasmid. Soluable recombinant proteinwas highly expressed. After a purification with GST-binding beads, the recombinantwas used as the diagnosis antigen, which can react with the sera of micewith an5-dayand55-day post infection, which suggests the diagnotic significance of therecombinant antigen to detect the infection of hosts at diffenrent stages, which can beused to diagnose the infection of host at early stage. Simultaneously, the antigen wasshown to clearly differentiate negative and positive sera of mice, without a crossreactive with antibodies of the other pathogens tested in this study, which hints thespecificity of the antigen.In order to investigate two kinds of ticks-borne deseases including B.microti andlyme disease, this experiment employed the GST-tBmSA1protein and GST-tFlaA asantigens, to react with2641sera samples incluing cows, sheeps, pigs, dogs, mice andthe mouse rabbits from Shanghai, Zhejiang, Jiangsu, henan, Guangxi, and Qinghaiprovinces to perform ELISA. The result indicates that the infection rate of pigs withB.microti15.0%, which is the highest among the tested animals, and the lower one are the dogs (the infection rate is12.22%). The infection rate of wild mouse is10.67%, which rank the third. The infection rates of other tested animals are under6%. As for B. burgdorferi, the infection rate of dogs is the highest(7.48%), followedby that of the goat (infection rate is5.99%), and the pigs (infection rate is5.2%), Inthe present study, the infection rates of other species are under5%. And theantibodies was not detected in the sera of mice and the mouse ribbits.A highly effective ELISA method to diagnose B.microti was established, inaddition, two kinds of tick-brone diseases were investigated on many kinds of animalsfrom different provinces of China, The study results provided important data fortick-borne diseases epidemic situation, which also provided the theoreticalbase, forthe provention and control of these diseases and showed great significance on theveterinary and hygiene.