›› 2018, Vol. 61 ›› Issue (1): 11-17.doi: 10.16380/j.kcxb.2018.01.002

• 研究论文 • 上一篇    下一篇

白纹伊蚊抗溴氰菊酯品系的筛选及其对登革病毒的易感性

贾志荣1, 刘转转1, 2, 王晓明1, Tricia WILLIAMS1, 刘培文1, 李小聪1, 闫桂云1, 陈晓光1,*   

  1.  (1. 南方医科大学公共卫生学院病原生物学系暨广东省热带病防治研究重点实验室, 广州 510515; 2. 徐州医科大学病原生物学与免疫学系, 感染与免疫实验室, 安徽徐州 221004)
  • 出版日期:2018-01-20 发布日期:2018-01-20

Screening of the deltamethrin-resistant strain of Aedes albopictus (Diptera: Culicidae) and its susceptibility to dengue virus

JIA Zhi-Rong1, LIU Zhuan-Zhuan1,2, WANG Xiao-Ming1, Tricia WILLIAMS1, LIU Pei-Wen1, LI Xiao-Cong1, YAN Gui-Yun1, CHEN Xiao-Guang1,*   

  1. (1. Key Laboratory of Tropical Disease Research of Guangdong Province, Department of Pathogen Biology, School of Public Health, Southern Medical University, Guangzhou 510515, China; 2. Laboratory of Infection and Immunity, Department of Pathogenic Biology and Immunology, Xuzhou Medical University,Xuzhou, Anhui 221004, China)
  • Online:2018-01-20 Published:2018-01-20

摘要: 【目的】建立白纹伊蚊Aedes albopictus抗溴氰菊酯的蚊虫品系,对比白纹伊蚊敏感株和抗性株对登革病毒的易感性差异。【方法】采用浸渍法测定溴氰菊酯对白纹伊蚊幼虫的半数致死浓度(LC50);再以LC50水平的溴氰菊酯对白纹伊蚊幼虫进行群体筛选至第11代,并通过接触筒法检测各代成蚊抗性。以白纹伊蚊敏感株和获得的抗性株(第9代)雌蚊吸食含2型登革病毒(DENV-2)的血餐,于感染后0, 4, 7和10 d解剖蚊虫,收集中肠、卵巢和唾液腺,通过RT-PCR和实时荧光定量PCR分别检测各组织的DENV-2病毒感染率和感染量。【结果】白纹伊蚊经溴氰菊酯筛选至第9代后抗性趋于稳定。第9代抗性株幼虫的LC50为0.053 mg/L,抗性倍数为10.58,成蚊生测的蚊虫死亡率为80%,已达到中度抗性。感染后0 d,所有蚊虫的中肠均可测得DENV-2,而且抗性株的平均病毒感染量高于敏感株;后续时间点敏感株与抗性株蚊虫中肠均保持92.75%~97.18%的病毒感染率,且二株之间无显著性差异(P>0.05)。感染后4 d,两株蚊虫的卵巢中均可检测到DENV-2,感染后7 d和10 d的卵巢病毒感染率均显著高于4 d时(P<0.05),但在7 d和10 d两个时间点,敏感株和抗性株之间均无统计学差异(P>0.05),然而抗性株平均病毒感染量在每一个时间点都显著高于敏感株(P<0.05)。蚊虫唾液腺于感染后7 d检测到DENV-2,10 d时唾液腺的病毒感染率无明显升高且两株蚊虫之间病毒感染率和感染量均无统计学差异(P>0.05)。【结论】经溴氰菊酯的筛选使白纹伊蚊幼虫及成蚊抗性水平逐渐升高,建立了白纹伊蚊抗溴氰菊酯的实验室品系。DENV-2对白纹伊蚊抗性株和敏感株各个组织的感染率相近,但感染量有所不同,说明对溴氰菊酯有中度抗性的白蚊伊蚊对登革病毒的易感性在一定程度上发生了改变。

关键词: 白纹伊蚊, 抗药性, 溴氰菊酯, 登革病毒, 易感性

Abstract: 【Aims】 To establish a strain of the Asian tiger mosquito, Aedes albopictus,resistant to deltamethrin, and to compare the susceptibilities of the susceptible and resistant strains of Ae. Albopictus to dengue virus. 【Methods】 The lethal concentrationrequired to kill half of the sample (LC50 value) of deltamethrin against Ae. albopictus larvae was determined by impregnation method. Then, Ae. albopictus mosquitoes were selected at LC50 of deltamethrin for 11 generations. Deltamethrin resistance of each screened generation was tested by WHO tube assay. Female adults of the susceptible strain and the obtained resistant strain of Ae. albopictus were fed with defibrinated sheep blood mixed with dengue virus-2 (DENV-2). The midguts, ovaries and salivary glands from female adults of the two strains were dissected at 0, 4, 7 and 10 d post infection, and the infection rates and titers of DENV-2 in these tissues were detected by RT-PCR and RTqPCR, respectively. 【Results】 The resistance of Ae. albopictus to deltamethrin tended to be stable after selection for 9 generations. The LC50 value of deltamethrin against the 9th generation of this mosquito was 0.053 mg/L, the resistance ratio was 10.58, and the mortality rate of adults was 80%, showing that moderate resistance to deltamethrin was reached. DENV-2 was positive in all mosquitoes 0 d after infection and the virus titer in the resistant strain was higher than that in the susceptible strain. The infection rate in midguts of the susceptible and resistant strains by DENV-2 maintained between 92.75% and 97.18% at all the tested time points, without significant difference between both (P>0.05). The dissemination of DENV-2 in the ovaries started from 4 d. The infection rates in ovaries of the susceptible and resistant strains at 7 d and 10 d after infection by DENV-2 were significantly higher than those at 4 d (P<0.05). However, no significant difference existed between the two strains at the two time points of 7 and 10 d post infection (P>0.05). The average virus titer was higher in the resistant strain than in the susceptible strain at 4, 7 and 10 d post infection. The first positive detection of DENV-2 in salivary glands began at 7 d, and the infection rate showed no obvious increase at 10 d. Neither the infection rate nor the virus titer of salivary glands showed significant difference between the two strains (P>0.05). 【Conclusion】 The sequential administration of deltamethrin results in a gradual increase of the resistance level of Ae. albopictus larvae and adults. A laboratory strain of Ae. albopictus resistant to deltamethrin has been established. The susceptible and resistant strains infected with DENV-2 present similar infection rates but different virus titers, suggesting that the susceptibility of Ae. albopictus with moderate resistance to deltamethrin to dengue virus changes somewhat as compared to that of the susceptible strain.

Key words: Aedes albopictus, insecticide resistance, deltamethrin, dengue virus, susceptibility