Chines Journal of Vector Biology and Control ›› 2019, Vol. 30 ›› Issue (6): 597-602.DOI: 10.11853/j.issn.1003.8280.2019.06.001

• Original Reports •     Next Articles

Ecological niches of sandfly (Diptera: Psychodidae) in the extension region of Loess Plateau, China: an endemic focus of visceral leishmaniasis

CHEN Han-ming1, CHEN Hui-ying1, GAO Jing-peng1, LI Kai-li1, YANG Zhen-zhou2, PENG Heng3, MA Ya-jun1   

  1. 1 Department of Tropical Diseases, Faculty of Naval Medicine, Naval Medical University, Shanghai 200433, China;
    2 Institute of Disease Control and Prevention, People's Liberation Army of China;
    3 Department of Medical Microbiology and Parasitology, College of Basic Medical Sciences, Naval Medical University
  • Received:2019-07-02 Online:2019-12-20 Published:2019-12-20
  • Supported by:
    Supported by the National Natural Science Foundation of China (No. 81371848) and the National Science and Technology Major Project of China (No. 2017ZX10303404002-001)

我国黄土高原延伸地带利什曼病流行区的传播媒介小生境调查

陈翰明1, 陈辉莹1, 高景鹏1, 李凯利1, 杨振洲2, 彭恒3, 马雅军1   

  1. 1 海军军医大学海军医学系热带病学教研室, 上海 200433;
    2 解放军疾病预防控制中心, 北京 100071;
    3 海军军医大学基础医学院, 上海 200433
  • 通讯作者: 马雅军,Email:yajun_ma@163.com;彭恒,Email:pengheng0923@126.com
  • 作者简介:陈翰明,男,硕士,从事媒介生物学研究,Email:13482329184@163.com
  • 基金资助:
    国家自然科学基金(81371848);国家科技重大专项(2017ZX10303404002-001)

Abstract: Objective To investigate the ecological niches of sandflies in the endemic area of visceral leishmaniasis in the extension regions of the Loess Plateau, China, and to determine the infection status of Wolbachia in sandflies. Methods Sandflies were collected in Shan county, Henan province, China (in July 2015) and Yangquan and Wuxiang county, Shanxi province, China (in June and July, 2017). Meanwhile, the habitats were observed and investigated. The sandflies were sorted in the field according to their external morphology; the fresh samples were randomly selected for dissection. The species were identified by observing their pharyngeal armatures and spermathecae. Molecular identification was performed according to partial sequences of the mitochondrial DNA cytochrome b (mtDNA Cyt b) gene. The 16S rRNA fragments of Wolbachia were amplified by PCR to determine the infection status of Wolbachia in sandflies. Results The sites for sandfly collection were typical extension regions of the Loess Plateau with a large area of bare land. A total of 2 273 sandflies were collected in Shan county, Henan province; female sandflies accounted for 79.60% (1 635/2 054) in chicken houses and 93.15%(204/219) in cave dwellings and courtyards, both of which were higher than those of male sandflies. In Yangquan and Wuxiang county, Shanxi province, 3 599 and 2 850 sandflies were captured, respectively. The proportion of female sandflies was much higher than that of male sandflies in both areas. Among the collected sandflies, 99.60%(3 444/3 458) were female sandflies captured in chicken farms and 74.01%(2 549/3 444) of the female sandflies took blood meal. It could be inferred that chickens, sheep, pigs, dogs, ducks, geese, donkeys, and cattle (whether fed concentratedly or scatteredly) in the countryyards were blood source animals for sandflies and the loose soil surrounding those animals were breeding sites for sandflies. All the 50 sandflies identified by morphology were Phlebotomus chinensis. Molecular identification showed that all the 108 sandflies were Ph. chinensis except one that was identified as Sergentomyia squamirostris (found in Shan county, Henan province). Phlebotomus chinensis was the dominant species in the area, and the peak activity season for local sandflies ranged from June to July every year. Wolbachia detection was positive in 9 pooled samples from Shan county, 6 pooled and 56 individual samples from Yangquan city, 10 pooled and 79 individual samples from Wuxiang county. The infection rate for the individual sandfly was 51.85% (56/108) in Yangquan and 73.15% (79/108) in Wuxiang county. Conclusion The ecological niches of vector Ph. chinensis have been identified in the extension regions of the Loess Plateau, which is an important endemic area of leishmaniasis in China. Wolbachia has a high infection rate among the on-site Ph. chinensis population.

Key words: Sandfly, Stretching region of the Loess Plateau, Microhabitat, Wolbachia

摘要: 目的 调查我国黄土高原延伸地带内脏利什曼病流行区白蛉的小生境,并检测其体内沃尔巴克氏体感染情况。方法 2015年7月在河南省陕县、2017年6、7月在山西省阳泉市和武乡县采集白蛉,同时观察和了解当地环境。现场依据外部形态分拣白蛉,随机挑选新鲜样本解剖,观察其咽甲和受精囊,进行鉴定。并依据线粒体DNA细胞色素b(mtDNA Cyt b)的部分序列,进行分子鉴别。PCR法扩增沃尔巴克氏体16S rRNA部分片段,确定白蛉体内沃尔巴克氏体感染情况。结果 白蛉采集地均为典型的黄土高原延伸地带,裸露的土地面积大。在河南省陕县共采集白蛉2 273只,其中雌蛉在鸡舍中占79.60%(1 635/2 054),在窑洞和院落占93.15%(204/219),均高于雄蛉;在山西省阳泉市和武乡县分别捕获白蛉3 599和2 850只,雌蛉比例均远大于雄蛉,其中在养鸡场诱集的雌蛉占99.60%(3 444/3 458),吸血个体比例占雌蛉的74.01%(2 549/3 444);可见村内集中或散养的鸡、羊、猪、犬、鸭、鹅、驴和牛等都可能是白蛉的血源动物,周边分散的疏松土壤是其孳生地。形态鉴定的50只均为中华白蛉,分子鉴定显示,除河南省陕县的1只为鳞喙司蛉外,其余107只均为中华白蛉,中华白蛉为当地的优势种,每年的6-7月是当地白蛉活动的高峰季节。沃尔巴克氏体感染检测结果显示,河南省陕县的9组混合样本、山西省阳泉市的6组混合和56只单个样本、武乡县的10组混合和79只单个样本呈阳性。单只白蛉感染率山西省阳泉市为51.85%(56/108),武乡县为73.15%(79/108)。结论 明确了我国重要的利什曼病流行区黄土高原延伸地带传播媒介中华白蛉的小生境,沃尔巴克氏体在现场中华白蛉群体中感染率高。

关键词: 白蛉, 黄土高原延伸地带, 小生境, 沃尔巴克氏体

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