[Isolation and identification of Borrelia burgdorferi sensu lato from ticks in six provinces in China].

Objective: To understand the carrying status of Borrelia burgdorferi in ticks from the mountain areas from six representative provinces, including Jilin, Shanxi, Gansu, Qinghai, Guizhou and Hunan in China.

Methods: Flagging and trapping methods were used to collect ticks in forest area and culture medium was used to isolate the pathogen. Nested-PCR was used to detect the germ-carrying rate of ticks.

Results: More than 2200 ticks from six representative provinces were collected and 1000 ticks were used to isolate the pathogen. 13 Lyme disease spirochetes from ixodes persulcatus in Changbai, Jilin province and 9 Lyme disease spirochetes from ixodes granulatus in Daozhen, Guizhou province were identified. There were 1255 ticks used for PCR testing. Specific fragments of the Borrelia burgdorferi in ticks were found from the six representative provinces in China. The carrier rate was higher in Jilin (Changbai 27.08%, Tonghua 20.41%), Qinghai (Huzhu 25.06%, Huangnan 21.11%) and Guizhou (Daozhen 25.63%), than in Shanxi (Yuanqu 4.72%, Jiaocheng 3.64%). Result from the sequence analysis showed that the genotype belong to Borrelia garinii in Jilin, Qinghai, Gansu, Shanxi provinces but Borrelia valaisiana in Guizhou and Hunan provinces.

Conclusion: Our data showed that there existed Lyme disease spirochetes in all the six representative provinces in China, but the carriying rates of ticks were different. Borrelia garinii was found in Shanxi province, and Borrelia valaisiana in Hunan province.