Prevalence of Borrelia burgdorferi sensu lato in ticks from eastern China.

Juan Hou,Ye Lu,Jimin Sun,Zhenyu Gong,Chengliang Chai,Chengwei Wang,Junfen Lin,Yue Chang,Feng Ling,Xianghua Yu,Xiaodong Ye,Shiping Gu,Jianmin Jiang,Weilong Pang,Zhiping Chen,Xiaohua Zheng

doi:10.4269/ajtmh.14-0587

Abstract

To explore the tick distribution and prevalence of Borrelia in Zhejiang Province, we performed a survey in nine sites. A total of 447 adult ticks of 11 species were captured and the dominant tick species were Haemaphysalis longicornis and Ixodes sinensis and the abundance of tick species in different areas varied significantly. Overall, 4.70% of the ticks were polymerase chain reaction (PCR) positive for Borrelia. The average PCR positive rates were 5.19% for H. longicornis, 3.45% for Amblyomma testudinarium, 1.06% for I. sinensis, 5.00% for Rhipicephalus (Boophilus) microplus, and 19.44% for Ixodes granulatus, respectively. No Borrelia DNA was detected in Rhiphicephalus haemaphysaloides, Haemaphysalis yeni, Dermacentor taiwanensis, Haemaphysalis hystricis, Hyalomna asiaticum, and Ixodes ovatus. The prevalence of Borrelia was significantly different among tick species and the prevalence in I. granulatus was significantly higher than that in other tick species. Of note, experimentally confirmed vectors for B. burgdorferi s.l. including I. sinensis and I. granulatus were found in Zhejiang Province. Two species of B. burgdorferi s.l. exist in Zhejiang Province of which 12 sequences were most similar to the sequence of Borrelia garinii and nine sequences were most similar to the sequence of Borrelia valaisiana or Borrelia yangtze sp. nov.

Highlights

MATERIALS AND METHODSTicks are important vectors for human and animal pathogens of viral, bacterial, and protozoan nature worldwide
Haemaphysalis longicornis was dominant in Daishan (91.38%), Xinchang (80.00%), Taishun (76.67%), and Yongjia (94.29%); H. longicornis (21.43%), Rhiphicephalus haemaphysaloides (21.43%), and I. sinensis (22.86%) in Jindong; I. sinensis (100%) in Tiantai; H. longicornis (58.14%) and Rhipicephalus microplus (41.86%) in Xianju; Amblyomma testudinarium (23.96%) and I. sinensis (65.63%) in Anji; Ixodes granulatus (100%) in Wencheng (Table 2)
R. haemaphysaloides and A. testudinarium were all from domestic dogs, all B. microplus were from cattle, H. yeni, H. hystricis, and H. asiaticum from S. scrofa, D. taiwanensis and I. ovatus were from Eragrotis amurensis

Summary

MATERIALS AND METHODS

Ticks are important vectors for human and animal pathogens of viral, bacterial, and protozoan nature worldwide. To explore the tick distribution and prevalence of Borrelia, we performed a survey in nine locations in Zhejiang Province in Eastern China. Each adult tick was subjected individually to DNA extraction. All tick samples were screened for Borrelia infection through testing them individually by nested PCR amplification, which was performed using a MyCyclerThermal Cycler (BIO-RAD, Hercules, CA) with the primers (Table 1) designed to amplify a fragment of 5S-23S rRNA as described previously.[6]. In each PCR, at least two negative controls contained mastermix and sterile water instead of DNA template. Bidirectional sequencing of positive PCR products were commercially conducted by Shanghai Sangon Biotechnology Co. C2 test, or Fisher’s exact test was used to compare Borrelia prevalence among different tick species, different sampling sites, and different host species. Statistical analysis was performed with the use of Statistical Product and Service Solutions (SPSS 11.0; Chicago, IL)

RESULTS

B2 B3 B4

DISCUSSION