African Regional Postgraduate Programme in Insect Science (ARPPIS), University of Ghana, Legon, Accra, Ghana.
Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana.
PLoS One. 2020 Sep 18;15(9):e0238931. doi: 10.1371/journal.pone.0238931. eCollection 2020.
Some bacteria species found in the mosquito midgut have demonstrated their role in interrupting the development of Plasmodium within the midgut of the Anopheles mosquito and have been identified as potential candidates for novel bacteria-mediated disease control. However, to use these bacteria successfully in biocontrol mechanisms their effect on the fitness of the vector into which they have been introduced has to be evaluated. This study investigated the effect of two such bacteria candidates, Enterobacter cloacae and Serratia marcescens, on Anopheles gambiae s.l. fitness. Pupae and larvae of Anopheles gambiae s.l. mosquitoes were collected by dipping method and reared to adults. The effect of these bacteria on mosquito fitness was assessed by reintroducing isolates of each bacteria separately into antibiotic-treated female adult mosquitoes through sugar meal. Wild type (non-antibiotic-treated) mosquitoes and those antibiotic-treated with no bacteria reintroduction were used as controls. The mosquitoes were monitored on longevity/survival, fecundity, hatch rate, and larval survival. The antibiotic-treated adult mosquitoes had reduced life span with median survival of 14 days while the bacteria-reintroduced groups and the wild type survived to day 22 (p< 0.0001). Treatment with Enterobacter and Serratia did not affect the average egg deposition (p>0.05) but they affected hatch rates positively (p = 0.008). There was, however, some evidence that suggests Enterobacter could have a positive effect on larval development (p < 0.0001). With no observed negative effect on survival/longevity of Anopheles gambiae, introducing E. cloacae and S. marcescens in future bacteria-associated control strategies is unlikely to result in mosquitoes that will be outlived by the wild population. This, however, requires evaluations under field conditions.
一些在蚊子中肠中发现的细菌物种已经证明了它们在中断疟原虫在按蚊中肠内发育方面的作用，并已被确定为潜在的候选新型细菌介导的疾病控制。然而，为了在生物控制机制中成功使用这些细菌，必须评估它们对引入的媒介物适应度的影响。本研究调查了两种候选细菌，阴沟肠杆菌和粘质沙雷氏菌，对冈比亚按蚊适应度的影响。通过浸泡法收集冈比亚按蚊的蛹和幼虫，并将其饲养至成虫。通过糖餐将每种细菌的分离物分别重新引入经抗生素处理的雌性成蚊中，评估这些细菌对蚊子适应度的影响。野生型（未用抗生素处理）蚊子和未用细菌重新引入的抗生素处理蚊子被用作对照。监测蚊子的寿命/存活率、繁殖力、孵化率和幼虫存活率。经抗生素处理的成年蚊子寿命缩短，中位生存时间为 14 天，而细菌重新引入组和野生型蚊子存活至第 22 天（p<0.0001）。用阴沟肠杆菌和粘质沙雷氏菌处理不会影响平均产卵量（p>0.05），但它们会积极影响孵化率（p = 0.008）。然而，有一些证据表明阴沟肠杆菌可能对幼虫发育有积极影响（p < 0.0001）。在不影响冈比亚按蚊生存/寿命的情况下，在未来的细菌相关控制策略中引入阴沟肠杆菌和粘质沙雷氏菌不太可能导致蚊子的寿命超过野生种群。然而，这需要在野外条件下进行评估。
