Ramirez José L, Gore Haley M, Payne Angela, Pinto Salorrane Miranda Nascimento, Flor-Weiler Lina B, Fernandes Everton K K, Muturi Ephantus J
Crop BioProtection Research Unit, USDA-ARS, National Center for Agricultural Utilization Research, 1815 N. University St., Peoria, IL 61604, USA.
Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74690-900, GO, Brazil.
J Fungi (Basel). 2025 Aug 21;11(8):608. doi: 10.3390/jof11080608.
The increasing global burden of mosquito-borne diseases and the widespread development of insecticide resistance in mosquitoes have fueled renewed interest in entomopathogenic fungi as effective tools that are compatible with existing mosquito control strategies. These fungi produce different types of infective propagules, including hydrophobic conidia and yeast-like blastospores, which differ in structure, mode of infection, and virulence. In this study, we evaluated the larvicidal activity of conidial and blastospore propagules from MBC076 and MBC397 against . Conidia exhibited more rapid and more potent larvicidal effects compared to blastospores, but the overall survival at seven days post-infection was similar between the two types of propagules. Interestingly, blastospore infections resulted in a significantly higher proportion of pupal mortality, suggesting a delayed mode of action. Immune profiling of infected larvae indicated significant induction of antimicrobial effectors such as cecropin, defensin, and attacin, primarily in response to conidial infection. In contrast, blastospore infections were associated with reduced expression of several prophenoloxidase genes, particularly during infection with blastospores. These findings indicate that different fungal species and their propagule types exert varying levels of virulence and immune modulation in mosquito larvae. This study provides insights into the infection dynamics of fungal propagules and identifies immune markers that can be leveraged to enhance the efficacy of fungal-based larvicides.
蚊媒疾病在全球造成的负担日益加重，且蚊子对杀虫剂的抗药性广泛出现，这使得人们重新对昆虫病原真菌产生兴趣，将其作为与现有蚊虫控制策略兼容的有效工具。这些真菌产生不同类型的感染性繁殖体，包括疏水性分生孢子和酵母样芽生孢子，它们在结构、感染方式和毒力方面存在差异。在本研究中，我们评估了MBC076和MBC397的分生孢子和芽生孢子繁殖体对[具体蚊虫种类未给出]的杀幼虫活性。与芽生孢子相比，分生孢子表现出更快且更强的杀幼虫效果，但两种繁殖体在感染后七天的总体存活率相似。有趣的是，芽生孢子感染导致蛹死亡率显著更高，表明其作用方式较为延迟。对受感染幼虫的免疫分析表明，抗菌效应分子如天蚕素、防御素和攻击素显著诱导，主要是对分生孢子感染的反应。相比之下，芽生孢子感染与几种前酚氧化酶基因的表达降低有关，尤其是在感染[具体芽生孢子种类未给出]芽生孢子期间。这些发现表明，不同的真菌种类及其繁殖体类型在蚊虫幼虫中发挥不同程度的毒力和免疫调节作用。本研究深入了解了真菌繁殖体的感染动态，并确定了可用于提高基于真菌的杀幼虫剂功效的免疫标志物。
