Investigation On Tick Species And Tick-Borne Rickettsia In Border Areas Between China And Korea

Tick-borne Rickettsia disease(TBRD)is caused by Spotted Fever Group Rickettsia(SFG)infection resulting in great disease,even death in humans,livestock and wildlife.So far,at least 26 species of spotted fever group Rickettsia have been reported in the world.However,the systematic detection and analysis of tick-borne Rickettsia in the China and Korea border areas is rarely investigated(Dandong,Yanbian).This experiment focused on the distribution of ticks and the situation of ticks carrying Rickettsia pathogens in border areas.The results showed that there was an epidemic of Rickettsia in this area,causing great threat to human and animal health.Experiment 1 Morphological and mitochondrial 16 S r DNA gene identification of ticks in the border area between China and Korea(Dandong and Yanbian regions).Experiment 2 To study the method of multiple displacement amplification(MDA)for effective amplification of DNA of single tick and detection and typing of pathogens.Experiment 3 Polymerase chain reaction(PCR)was used to detect the three gene fragments of outer membrane protein(omp A,omp B)and cell surface antigen 1(sca1)in ticks collected from the border areas of North Korea(Dandong and Yanbian).To sum up,four ticks were detected in 805 ticks from 15 counties and cities in the border area between China and DPRK(Dandong and Yanbian),namely,Haemaphysalis longicornis,Haemaphysalis concinna,Haemaphysalis japonica and Ixodes persulcatus.With the use of MDA technology,we can effectively amplify the samples with low DNA concentration and get enough DNA samples for pathogen detection and analysis.A total of 206 Rickettsia positive samples were detected,and the detection rate of the pathogen was 25.59%.Rickettsia sp.,Rickettsia raoultii,Rickettsia japonica and Rickettsia heilongjiangensis were found in ticks.The infection rate of Rickettsia in border counties and cities ranged from 0% to 100%.