Ong'wen Fedinand, Njoroge Margaret Mendi, Fillinger Ulrike, Lutermann Heike, Bukhari Tullu
Human Health Theme, International Centre of Insect Physiology and Ecology, Nairobi P.O. Box 30772-00100, Kenya.
Department of Zoology and Entomology, Faculty of Natural & Agricultural Sciences, University of Pretoria, Private Bag x 20, Hatfield 0028, South Africa.
Insects. 2024 Jun 13;15(6):449. doi: 10.3390/insects15060449.
Arthropod vectors are responsible for a multitude of human and animal diseases affecting poor communities in sub-Saharan Africa. Their control still relies on chemical agents, despite growing evidence of insecticide resistance and environmental health concerns. Biorational agents, such as the entomopathogenic fungus , might be an alternative for vector control. Recently, the isolate ICIPE 7 has been developed into a commercial product in Kenya for control of ticks on cattle. We were interested in assessing the potential of controlling not only ticks but also disease-transmitting mosquitoes and tsetse flies using cattle as blood hosts, with the aim of developing a product for integrated vector management. Laboratory bioassays were carried out with , isolate ICIPE 7 and isolate ICIPE 30, to compare efficacy against laboratory-reared . ICIPE 7 was further tested against wild and spp. Dose-response tests were implemented, period of mosquito exposure was evaluated for effects on time to death, and the number of spores attached to exposed vectors was assessed. Exposure to 10 spores/mL of ICIPE 7 for 10 min resulted in a similar mortality of as exposure to ICIPE 30, albeit at a slower rate (12 vs. 8 days). The same ICIPE 7 concentration also resulted in mortalities of tsetse flies (LT: 16 days), tick nymphs (LT: 11 days), and adult ticks (LT: 20 days). Mosquito mortality was dose-dependent, with decreasing LT of 8 days at a concentration of 10 spores/mL to 6 days at 10 spores/mL. Exposure period did not modulate the outcome, 1 min of exposure still resulted in mortality, and spore attachment to vectors was dose-dependent. The laboratory bioassays confirmed that ICIPE 7 has the potential to infect and cause mortality to the three exposed arthropods, though at slower rate, thus requiring further validation under field conditions.
节肢动物媒介传播多种影响撒哈拉以南非洲贫困社区人类和动物的疾病。尽管越来越多的证据表明存在杀虫剂抗性以及对环境健康的担忧，但它们的控制仍依赖化学药剂。生物理性制剂，如昆虫病原真菌，可能是媒介控制的一种替代方法。最近，分离株ICIPE 7已在肯尼亚开发成一种商业产品，用于控制牛身上的蜱虫。我们有兴趣评估以牛作为血源宿主来控制不仅是蜱虫，还有传播疾病的蚊子和采采蝇的潜力，目的是开发一种用于综合媒介管理的产品。用分离株ICIPE 7和分离株ICIPE 30进行了实验室生物测定，以比较对实验室饲养的[具体昆虫名称未给出]的功效。ICIPE 7还针对野生[具体昆虫名称未给出]和[具体昆虫名称未给出]属进行了进一步测试。进行了剂量反应测试，评估蚊子暴露时间对死亡时间的影响，并评估附着在暴露媒介上的孢子数量。暴露于10个孢子/毫升的ICIPE 7 10分钟导致[具体昆虫名称未给出]的死亡率与暴露于ICIPE 30相似，尽管速度较慢（12天对8天）。相同的ICIPE 7浓度也导致采采蝇（半数致死时间：16天）、蜱若虫（半数致死时间：11天）和成年蜱（半数致死时间：20天）的死亡。蚊子死亡率呈剂量依赖性，在10个孢子/毫升的浓度下半数致死时间从8天降至6天。暴露时间并未调节结果，1分钟的暴露仍导致死亡，且孢子附着在媒介上呈剂量依赖性。实验室生物测定证实ICIPE 7有感染并导致三种暴露节肢动物死亡的潜力，尽管速度较慢，因此需要在野外条件下进一步验证。
