Investigation On The Pathogens Of Tick-borne Diseases In Parts Of Natural Scenic Spots In China

Objective: To investigate the distribution species of ticks and the infection and coinfection status of Borrelia burgdorferi sensu lato、Anaplasma phagocytophilum、Spotted fever group Rickettsiae and Babesia in ticks and rodents from the Mudanjiang Jingbo lake of Heilongjiang pvovince、the Sanmenxia Ganshan National Forest Park of Henan province、the Wuyishan Scenic Area of Fujian province and the Pingxiang Youyiguan Scenic Area of Guangxi province. The findings from these researches are expected to provide scientific support for prevention and control of these tick-borne diseases.Methods: The free ticks were collected manually with white cloth frag from the grassland and the forest area. The parasitic ticks were collected on the host skin of domestic animals(such as cattle,sheep and dog). Rodents were trapped by the night trapping method, and birds were caught by using netting. Genome DNA were extracted from collected samples.Four kinds of pathogens B.b.s.l, AP,SFGR and Babesia was detected by PCR or Nested- PCR Positive samples were sequenced by commercial sequencing. Sequence analysis was done by alignment of the resulting sequences with sequences in NCBI database. The statistical analysis was done using SPSS 19.0 software(including c2-test and Fisher’s exact test).The phylogenetic analysis were performed using MEGA 5.0 software.Results: A total number of 903 ticks were collected from the Mudanjiang Jingbo lake in 2012 and 2013,including 781 Haemaphysalis concinna、70 Ixodes persulcatus and 52 Haemaphysalis japonica,the infection rate of Borrelia burgdorferi sensu lato in ticks was 1.33%(12/903), Haemaphysalis concinna,Ixodes persulcatus,Haemaphysalis japonica positive rates were 0.17%, 15.71%,0.00% respectively.There is statistical difference in the rates of Borrelia burgdorferi sensu lato infection among Haemaphysalis concinna, Ixodes persulcatus and Haemaphysalis japonica(c2=50.03,P<0.05). According to the sequences analysis, these strains were belong to B.afzelii and B. garinii genotypes. The infection rate of Spotted fever group rickettsiae in ticks was 6.31%(57/903), Haemaphysalis concinna、Ixodes persulcatus, Haemaphysalis japonica positive rates were 3.97%, 35.71% and 1.92% respectively. There is statistical difference in the rates of Spotted fever group Rickettsia infection among Haemaphysalis concinna,Ixodes persulcatus and Haemaphysalis japonica(c2=63.29,P<0.05). According to the sequences analysis, these strains were belong to Rickettsia heilongjiangii、Rickettsia raoultii、Candidatus Rickettsia tarasevichiae and an unknown genotypes of Spotted fever group Rickettsia. The infection rate of Anaplasma phagocytophilum in ticks was 0.22%(2/903). There is no significant difference in theinfections of AP among Haemaphysalis concinna、 Haemaphysalis japonica and Ixodes persulcatus(c2=5.04,P﹥0.05). According to the sequences analysis, These strains had higher homology of nucleotides sequence with China-Russia border and the northeast area of China.The infection rate of Babesia in ticks was 0.22%(2/903). There is no significant difference in the infections of Babesia among Haemaphysalis concinna、 Haemaphysalis japonica and Ixodes persulcatus(c2=5.04,P﹥0.05). According to the sequences analysis, the strain were belong to Babesia microti. The coinfection was detected of B.b.s.1 and AP, B.b.s.1 and Babesia, B.b.s.1 and SFGR in ticks from Jingbo lake of Mudanjiang city.Four kinds of pathogens was not found in 12 rodents from the Mudangjiang Jingbo lake.The infection rate of Spotted fever group rickettsiae in ticks was 0.40%(1/248) from the Sanmenxia Ganshan National Forest Park. According to the sequences analysis, the strain were belong to Rickettsia sp.The infection of Borrelia burgdorferi sensu lato in rodents was 5.66%(3/53) from the Pingxiang Youyiguan Scenic Area. 161 Haemaphysalis cornigera of parasitic ticks was not detected the presence of pathogens. According to the sequences analysis, the strain were belong to B. valaisiana.31 parasitic ticks was not detected the presence of pathogens from the Wuyishan Scenic Area.Conclusion: The ticks from the Mudanjiang Jingbo lake were detected in four kinds of pathogen infection. Ixodes persulcatus was detected four pathogens infection and coinfection from the Mudanjiang Jingbo lake. The ticks was detected Spotted fever group rickettsiae from the Sanmenxia Ganshan National Forest Park. The rodents were detected Borrelia burgdorferi sensu lato from the Pingxiang Youyiguan Scenic Area. This study laid a foundation for further studies of the tick-borne disease in natural scenic spot of China. The local Public health agency should be paid attention the prevention and control of the tick-borne diseases in natural scenic spot.