评估印度内脏利什曼病传播媒介——白蛉属(Phlebotomus argentipes)的杀虫剂敏感性、诊断剂量和时间,采用 CDC 瓶生物测定法。
Assessing insecticide susceptibility, diagnostic dose and time for the sand fly Phlebotomus argentipes, the vector of visceral leishmaniasis in India, using the CDC bottle bioassay.
机构信息
Kala-Azar Medical Research Center, Muzaffarpur, Bihar, India.
Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
出版信息
PLoS Negl Trop Dis. 2023 May 10;17(5):e0011276. doi: 10.1371/journal.pntd.0011276. eCollection 2023 May.
Visceral leishmaniasis (VL) is a vector-borne protozoan disease, which can be fatal if left untreated. Synthetic chemical insecticides are very effective tools for controlling of insect vectors, including the sand fly Phlebotomus argentipes, the vector of VL in the Indian subcontinent. However, repeated use of the same insecticide with increasing doses potentially can create high selection pressure and lead to tolerance and resistance development. The objective of this study was to determine the lethal concentrations and assess levels of susceptibility, diagnostic doses and times to death of laboratory-reared P. argentipes to five insecticides that are used worldwide to control vectors. Using the Center for Disease Control and Prevention (CDC) bottle bioassay, 20-30 sand flies were exposed in insecticide- coated 500-ml glass bottles. Flies were then observed for 24 hours and mortality was recorded. Dose-response survival curves were generated for each insecticide using QCal software and lethal concentrations causing 50%, 90% and 95% mortality were determined. A bioassay was also conducted to determine diagnostic doses and diagnostic times by exposing 20-30 flies in each bottle containing set concentrations of insecticide. Mortality was recorded at 10-minute intervals for 120 minutes to generate the survival curve. Phlebotomus argentipes are highly susceptible to alpha-cypermethrin, followed by deltamethrin, malathion, chlorpyrifos, and least susceptible to DDT. Also, the lowest diagnostic doses and diagnostic times were established for alpha-cypermethrin (3μg/ml for 40 minutes) to kill 100% of the flies. The susceptibility data, diagnostic doses and diagnostic times presented here will be useful as baseline reference points for future studies to assess insecticide susceptibility and resistance monitoring of field caught sand flies and to assist in surveillance as VL elimination is achieved in the region.
内脏利什曼病(VL)是一种由寄生虫引起的疾病,如果不及时治疗可能致命。合成化学杀虫剂是控制昆虫媒介的非常有效工具,包括在印度次大陆传播 VL 的白蛉。然而,重复使用相同的杀虫剂并增加剂量可能会产生很高的选择压力,导致耐受性和抗药性的发展。本研究的目的是确定实验室饲养的白蛉对五种在全球范围内用于控制媒介的杀虫剂的致死浓度,并评估其敏感性、诊断剂量和死亡时间。使用疾病控制与预防中心(CDC)瓶生物测定法,将 20-30 只白蛉暴露在涂有杀虫剂的 500 毫升玻璃瓶中。然后观察苍蝇 24 小时并记录死亡率。使用 QCal 软件为每种杀虫剂生成剂量-反应生存曲线,并确定引起 50%、90%和 95%死亡率的致死浓度。还进行了生物测定以确定诊断剂量和诊断时间,即将 20-30 只苍蝇暴露在每个含有设定浓度杀虫剂的瓶中。在 120 分钟内每 10 分钟记录一次死亡率,以生成生存曲线。白蛉对 alpha-氯氰菊酯高度敏感,其次是溴氰菊酯、马拉硫磷、毒死蜱,对滴滴涕最不敏感。此外,alpha-氯氰菊酯(40 分钟内 3μg/ml)的最低诊断剂量和诊断时间可杀死 100%的苍蝇。本研究提供的敏感性数据、诊断剂量和诊断时间将作为未来研究的基线参考点,用于评估现场捕获的白蛉对杀虫剂的敏感性和抗药性监测,并协助在该地区实现 VL 消除时进行监测。