National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India.
Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA.
Malar J. 2018 Jun 5;17(1):225. doi: 10.1186/s12936-018-2343-0.
As much as 80% of global Plasmodium vivax infections occur in South Asia and there is a shortage of direct studies on infectivity of P. vivax in Anopheles stephensi, the most common urban mosquito carrying human malaria. In this quest, the possible effects of laboratory colonization of mosquitoes on infectivity and development of P. vivax is of interest given that colonized mosquitoes can be genetically less divergent than the field population from which they originated.
Patient-derived P. vivax infected blood was fed to age-matched wild and colonized An. stephensi. Such a comparison requires coordinated availability of same-age wild and colonized mosquito populations. Here, P. vivax infection are studied in colonized An. stephensi in their 66th-86th generation and fresh field-caught An. stephensi. Wild mosquitoes were caught as larvae and pupae and allowed to develop into adult mosquitoes in the insectary. Parasite development to oocyst and sporozoite stages were assessed on days 7/8 and 12/13, respectively.
While there were batch to batch variations in infectivity of individual patient-derived P. vivax samples, both wild and colonized An. stephensi were roughly equally susceptible to oocyst stage Plasmodium infection. At the level of sporozoite development, significantly more mosquitoes with sporozoite load of 4+ were seen in wild than in colonized populations.
全球约 80%的间日疟原虫感染发生在南亚，而在携带人类疟疾的最常见城市蚊子——致倦库蚊中，关于间日疟原虫感染力的直接研究却很匮乏。在这一探索中，由于实验室饲养的蚊子在遗传上可能比它们起源的野外种群差异更小，因此研究蚊子的实验室饲养对间日疟原虫感染力和发育的可能影响很有意思。
将取自患者的间日疟原虫感染血液喂给年龄匹配的野生和实验室饲养的致倦库蚊。这种比较需要协调相同年龄的野生和实验室饲养的蚊子种群。在这里，研究了在第 66-86 代的实验室饲养的致倦库蚊中和新捕获的野外致倦库蚊中感染间日疟原虫的情况。野生蚊子在昆虫饲养室中从幼虫和蛹发育成成蚊。在第 7/8 天和第 12/13 天分别评估寄生虫发育到卵囊和子孢子阶段的情况。
虽然个别源自患者的间日疟原虫样本的感染力存在批次间的差异，但野生和实验室饲养的致倦库蚊对卵囊阶段疟原虫感染的敏感性大致相同。在子孢子发育水平上，在野生种群中观察到的具有 4+子孢子负荷的蚊子明显多于实验室饲养的种群。
