中国寄生虫学与寄生虫病杂志 ›› 2022, Vol. 40 ›› Issue (1): 76-83.doi: 10.12140/j.issn.1000-7423.2022.01.011

• 论著 • 上一篇    下一篇

闽东地区野生动物寄生蜱感染梨形虫状况的调查及基因型分析

周淑姮(), 曾志伟, 刘维俊, 王加熊, 徐国英, 肖方震*()   

  1. 福建省疾病预防控制中心,福建省人兽共患病研究重点实验室,福州 350001
  • 收稿日期:2021-06-16 修回日期:2021-08-05 出版日期:2022-02-28 发布日期:2022-01-29
  • 通讯作者: 肖方震
  • 作者简介:周淑姮(1973-),女,本科,副主任医师,从事病媒生物及人兽共患传染病研究。E-mail: 582777160@qq.com
  • 基金资助:
    福建省卫生健康中青年骨干人才培养项目(2019-ZQN-27);福建省医学创新课题(2020CXB010);福建省科技创新平台建设项目(2019Y2001)

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
  • 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)

摘要:

目的 了解福建省闽东地区野生动物寄生蜱感染梨形虫的状况及基因特征。 方法 于2014—2019年在闽东地区采集野生动物(野兔、山麂、野鼠、野猪)体表寄生的蜱样品,采用形态学辅以DNA条形码鉴定技术进行蜱种鉴定。提取蜱虫DNA,采用PCR扩增梨形虫18S rRNA片段,PCR产物纯化测序后,进行BLAST序列比对分析,并采用邻接法构建系统进化树。率的比较采用行列表χ2检验和Fisher’s确切概率法。 结果 共采集372只蜱,分属12种,其中成蜱338只(雌蜱181只,雄蜱157只),若蜱29只,幼蜱5只。372份蜱DNA样品PCR扩增共获得21份阳性产物,蜱的梨形虫总感染率为5.65%,其中中华硬蜱(3/9)和卵形硬蜱(4/13)感染率较高。不同发育期蜱的梨形虫感染率分别为成蜱5.32%(18/338),若蜱10.34%(3/29),幼蜱0(0/5),差异无统计学意义(Fisher’s确切概率法,P > 0.05);不同性别成蜱的梨形虫感染率分别为雌性7.18%(13/181),雄性3.18%(5/157),差异无统计学意义(χ2 = 2.67,P > 0.05)。野兔、山麂、野鼠、野猪等4种野生动物寄生蜱的梨形虫感染率分别为2/7、11.03%(15/136)、2.44%(1/41)、1.60%(3/188),差异有统计学意义(χ2 = 20.89,P < 0.01)。测序结果显示,共获得17条梨形虫18S rRNA序列片段,分属于泰勒虫(8条)和巴贝虫(9条),它们来自11个宿主体表的17只蜱样品,其中泰勒虫包括狍泰勒虫和Thelieria cervi 2个虫种,巴贝虫包括田鼠巴贝虫和3个未定种。系统进化树分析结果显示,在获得的17条基因序列中,源于台岛血蜱、褐黄血蜱、卵形硬蜱的4条与狍泰勒虫聚成一支,源于中华硬蜱和卵形硬蜱的4条与T. cervi聚成一支,源于越原血蜱的1条与未知巴贝虫1聚成一支,源于未知血蜱A的2条与未知巴贝虫2聚成一支,源于台岛血蜱和豪猪血蜱的3条与未知巴贝虫3聚成一支,源于卵形硬蜱和粒形硬蜱的3条与田鼠巴贝虫聚成一支。 结论 闽东地区野生动物多种寄生蜱感染巴贝虫和泰勒虫,存在对人及动物致病的风险。

关键词: 蜱, 巴贝虫, 泰勒虫, 基因特征, 闽东, 野生动物, 调查

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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