CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES ›› 2022, Vol. 40 ›› Issue (1): 76-83.doi: 10.12140/j.issn.1000-7423.2022.01.011

• ORIGINAL ARTICLES • Previous Articles     Next Articles

Investigation and genotype analysis of piroplasms in ticks parasitized on wild animals in eastern Fujian

ZHOU Shu-heng(), ZENG Zhi-wei, LIU Wei-jun, WANG Jia-xiong, XU Guo-ying, XIAO Fang-zhen*()   

  1. Fujian Center for Disease Control and Prevention, Fujian Provincial Key Laboratory of Zoonosis Research, Fuzhou 350001, China
  • Received:2021-06-16 Revised:2021-08-05 Online:2022-02-28 Published:2022-01-29
  • Contact: XIAO Fang-zhen E-mail:582777160@qq.com;18642028@qq.com
  • Supported by:
    Fujian Provincial Health Technology Project(2019-ZQN-27);Fujian Provincial Medical Innovation Project(2020CXB010);Construction of Fujian Provincial Scientific and Technological Innovation Platform(2019Y2001)

Abstract:

Objective To investigate the infection and genetic characteristics of piroplasms in ticks parasitized on wild animals in eastern Fujian. Methods Tick specimens were collected from wild animals in eastern Fujian between 2014 and 2019. The tick species were identified by morphology and DNA barcoding determination technology. Genomic DNA was extracted from tick specimens, PCR was used to amplify 18S rRNA gene sequence of piroplasms, and the PCR products were sequenced for alignment by BLAST, and for constructing phylogenetic tree using the neighbour joining method. Rate variables were analyzed using the row-list χ 2 test and Fisher’s exact test. Results In total, 372 ticks were collected, including 338 adults (181 females and 157 males), 29 nymphs and 5 larvae, belong to 12 species. The piroplasm 18S rRNA sequene was amplified in 372 tick DNA samples by PCR, and found 21 positives, revealing the overall piroplasm infection rate of 5.65% (21/327) in ticks. Among the infected, higher infection rate were found in Ixodes sinensis(3/9) and I. ovatus (4/13). The piroplasm infection rates of piriformis in different developmental stages of ticks were 5.32% (18/338) in adults, 10.34% (3/29) in nymphs and 0 (0/5) in larvae, respectively. The differences were not significant (Fisher’s exact test, P > 0.05). The piroplasm infection rates in adult ticks of different sexes were 7.18% (13/181) in females and 3.18% (5/157) in males, respectively, with no significant difference (χ2 = 2.67, P > 0.05). The infection rates in the ticks parasitized on hare, muntjac, field rodents and wild boar were 2/7, 11.03% (15/136), 2.44% (1/41) and 1.60% (3/188) respectively, with significant difference between the wild animal groups (χ 2 = 20.89, P < 0.01). Sequencing analysis showed that piroplasm 18S rRNA sequence was detected in 17 tick samples collected from 11 animals hosts’ body surface. The piropolasms detected belong to the genera Theileria (n = 8) and Babesia (n = 9). Specifically, the Thelieria comprises two species, T. capreoli and T. cervi, while the Babesia comprises B. microti as well as three undefined species. The phylogenetic tree analysis indicated that among the 17 positive sequences, 4 sequences sourced from Haemaphysalis formosensis, H. flava and I. ovatus clustered with T. capreoli, 4 sequences from I. sinensis and I. ovatus clustered with T. cervi, one sequence from H. yeni clustered with unknown Babesia 1, 2 sequences from unknown Haemaphysalis A clustered with unknown Babesia 2, 3 sequences from H. formosensis and H. hystricis clustered with unknown Babesia 3, and 3 sequences from I. ovatus and I. granulatus clustered with B. microti. Conclusion A variety of tick species parasitized on wild animals in eastern Fujian were found infected with Babesia and Theileria, there existing risks of transmission of the parasites to humans and animals.

Key words: Tick, Babesia, Thelieria, Genetic characteristics, Eastern Fujian, Wild animals, Investigation

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