Environmental Health and Ecological Sciences Department, Ifakara Health Institute, Morogoro, Tanzania.
Laboratory of Chemical Ecology of Insect Vectors, Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Parasit Vectors. 2018 Apr 11;11(1):236. doi: 10.1186/s13071-018-2823-7.
Controlled blood-feeding is essential for maintaining laboratory colonies of disease-transmitting mosquitoes and investigating pathogen transmission. We evaluated a low-cost artificial feeding (AF) method, as an alternative to direct human feeding (DHF), commonly used in mosquito laboratories.
We applied thinly-stretched pieces of polytetrafluoroethylene (PTFE) membranes cut from locally available seal tape (i.e. plumbers tape, commonly used for sealing pipe threads in gasworks or waterworks). Approximately 4 ml of bovine blood was placed on the bottom surfaces of inverted Styrofoam cups and then the PTFE membranes were thinly stretched over the surfaces. The cups were filled with boiled water to keep the blood warm (~37 °C), and held over netting cages containing 3-4 day-old inseminated adults of female Aedes aegypti, Anopheles gambiae (s.s.) or Anopheles arabiensis. Blood-feeding success, fecundity and survival of mosquitoes maintained by this system were compared against DHF.
Aedes aegypti achieved 100% feeding success on both AF and DHF, and also similar fecundity rates (13.1 ± 1.7 and 12.8 ± 1.0 eggs/mosquito respectively; P > 0.05). An. arabiensis had slightly lower feeding success on AF (85.83 ± 16.28%) than DHF (98.83 ± 2.29%) though these were not statistically different (P > 0.05), and also comparable fecundity between AF (8.82 ± 7.02) and DHF (8.02 ± 5.81). Similarly, for An. gambiae (s.s.), we observed a marginal difference in feeding success between AF (86.00 ± 10.86%) and DHF (98.92 ± 2.65%), but similar fecundity by either method. Compared to DHF, mosquitoes fed using AF survived a similar number of days [Hazard Ratios (HR) for Ae. aegypti = 0.99 (0.75-1.34), P > 0.05; An. arabiensis = 0.96 (0.75-1.22), P > 0.05; and An. gambiae (s.s.) = 1.03 (0.79-1.35), P > 0.05].
Mosquitoes fed via this simple AF method had similar feeding success, fecundity and longevity. The method could potentially be used for laboratory colonization of mosquitoes, where DHF is unfeasible. If improved (e.g. minimizing temperature fluctuations), the approach could possibly also support studies where vectors are artificially infected with blood-borne pathogens.
为了维持传播疾病的蚊子的实验室种群并研究病原体的传播，有必要进行受控的血液喂养。我们评估了一种低成本的人工喂养（AF）方法，作为蚊子实验室中常用的直接人喂养（DHF）的替代方法。
我们应用了从当地可用的密封胶带（即管道工胶带，通常用于在煤气厂或水厂密封管道螺纹）上切割的薄拉伸聚四氟乙烯（PTFE）膜。将约 4 毫升牛血放在倒置的聚苯乙烯杯的底部表面上，然后将 PTFE 膜薄薄地拉伸在表面上。杯子装满沸水以保持血液温暖（约 37°C），并放在装有 3-4 天大的已授精雌性埃及伊蚊、冈比亚按蚊（s.s.）或阿拉伯按蚊的网笼上。通过该系统维持的蚊子的血液喂养成功率、繁殖力和存活率与 DHF 进行了比较。
埃及伊蚊在 AF 和 DHF 上均实现了 100%的喂养成功率，并且产卵率也相似（分别为 13.1±1.7 和 12.8±1.0 个/蚊子；P>0.05）。阿拉伯按蚊在 AF 上的喂养成功率（85.83±16.28%）略低于 DHF（98.83±2.29%），尽管这些差异没有统计学意义（P>0.05），并且 AF（8.82±7.02）和 DHF（8.02±5.81）之间的产卵率也相似。同样，对于冈比亚按蚊（s.s.），我们观察到 AF（86.00±10.86%）和 DHF（98.92±2.65%）之间的喂养成功率存在微小差异，但两种方法的繁殖力相似。与 DHF 相比，通过 AF 喂养的蚊子存活的天数相似[埃及伊蚊的危险比（HR）=0.99（0.75-1.34），P>0.05；阿拉伯按蚊=0.96（0.75-1.22），P>0.05；冈比亚按蚊（s.s.）=1.03（0.79-1.35），P>0.05]。
通过这种简单的 AF 方法喂养的蚊子具有相似的喂养成功率、繁殖力和寿命。该方法可能可用于 DHF 不可行的蚊子实验室殖民化。如果加以改进（例如，尽量减少温度波动），该方法也可能支持对人工感染血源性病原体的媒介进行研究。
