Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA.
Biostatistics Research Branch, Division of Clinical Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA.
Parasit Vectors. 2024 Jul 6;17(1):290. doi: 10.1186/s13071-024-06364-9.
Aedes and Anopheles mosquitoes are responsible for tremendous global health burdens from their transmission of pathogens causing malaria, lymphatic filariasis, dengue, and yellow fever. Innovative vector control strategies will help to reduce the prevalence of these diseases. Mass rearing of mosquitoes for research and support of these strategies presently depends on meals of vertebrate blood, which is subject to acquisition, handling, and storage issues. Various blood-free replacements have been formulated for these mosquitoes, but none of these replacements are in wide use, and little is known about their potential impact on competence of the mosquitoes for Plasmodium infection.
Colonies of Aedes aegypti and Anopheles stephensi were continuously maintained on a blood-free replacement (SkitoSnack; SS) or bovine blood (BB) and monitored for engorgement and hatch rates. Infections of Ae. aegypti and An. stephensi were assessed with Plasmodium gallinaceum and P. falciparum, respectively.
Replicate colonies of mosquitoes were maintained on BB or SS for 10 generations of Ae. aegypti and more than 63 generations of An. stephensi. The odds of engorgement by SS- relative to BB-maintained mosquitoes were higher for both Ae. aegypti (OR = 2.6, 95% CI 1.3-5.2) and An. stephensi (OR 2.7, 95% CI 1.4-5.5), while lower odds of hatching were found for eggs from the SS-maintained mosquitoes of both species (Ae. aegypti OR = 0.40, 95% CI 0.26-0.62; An. stephensi OR = 0.59, 95% CI 0.36-0.96). Oocyst counts were similar for P. gallinaceum infections of Ae. aegypti mosquitoes maintained on SS or BB (mean ratio = [mean on SS]/[mean on BB] = 1.11, 95% CI 0.85-1.49). Similar oocyst counts were also observed from the P. falciparum infections of SS- or BB-maintained An. stephensi (mean ratio = 0.76, 95% CI 0.44-1.37). The average counts of sporozoites/mosquito showed no evidence of reductions in the SS-maintained relative to BB-maintained mosquitoes of both species.
Aedes aegypti and An. stephensi can be reliably maintained on SS over multiple generations and are as competent for Plasmodium infection as mosquitoes maintained on BB. Use of SS alleviates the need to acquire and preserve blood for mosquito husbandry and may support new initiatives in fundamental and applied research, including novel manipulations of midgut microbiota and factors important to the mosquito life cycle and pathogen susceptibility.
伊蚊属和按蚊属的蚊子通过传播导致疟疾、淋巴丝虫病、登革热和黄热病的病原体，对全球健康造成了巨大负担。创新的病媒控制策略将有助于降低这些疾病的流行率。目前，为了研究和支持这些策略，大量饲养蚊子需要以脊椎动物的血液为食，但血液的获取、处理和储存存在问题。已经为这些蚊子配制了各种无血替代品，但这些替代品都没有广泛使用，而且对它们对疟原虫感染的蚊子能力的潜在影响知之甚少。
埃及伊蚊和致倦库蚊的种群连续以无血替代品（SkitoSnack；SS）或牛血（BB）饲养，并监测其血餐摄入量和孵化率。用禽疟原虫和恶性疟原虫分别评估埃及伊蚊和致倦库蚊的感染情况。
在 SS 或 BB 上维持了 10 代埃及伊蚊和超过 63 代致倦库蚊的重复种群。SS 维持的蚊子的血餐摄入量高于 BB 维持的蚊子，无论是埃及伊蚊（OR=2.6，95%CI 1.3-5.2）还是致倦库蚊（OR=2.7，95%CI 1.4-5.5），而 SS 维持的蚊子的孵化率较低，无论是埃及伊蚊（OR=0.40，95%CI 0.26-0.62）还是致倦库蚊（OR=0.59，95%CI 0.36-0.96）。在 SS 或 BB 上维持的蚊子中，感染禽疟原虫的卵囊计数相似（感染 SS 的卵囊计数与感染 BB 的卵囊计数的平均比值 [mean on SS]/[mean on BB]=1.11，95%CI 0.85-1.49）。从 SS 或 BB 维持的致倦库蚊中观察到的感染恶性疟原虫的卵囊计数也相似（感染 SS 的卵囊计数与感染 BB 的卵囊计数的平均比值 [mean on SS]/[mean on BB]=0.76，95%CI 0.44-1.37）。两种蚊子的 SS 维持的平均感染疟原虫的子孢子数/蚊子均未显示出减少的证据。
埃及伊蚊和致倦库蚊可以在 SS 上连续多代可靠地维持，并且对疟原虫感染的能力与 BB 维持的蚊子一样。使用 SS 减轻了获取和保存血液用于蚊子饲养的需求，并可能支持基础和应用研究中的新举措，包括对中肠微生物群和对蚊子生命周期和病原体易感性很重要的因素的新操作。
