Preisegger Lautaro, Flecha Juan Cruz, Ghilini Fiorella, Espin-Sánchez Daysi, Prieto Eduardo, Oberti Héctor, Abreo Eduardo, Huarte-Bonnet Carla, Pedrini Nicolás, Mannino Maria Constanza
Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), Calles 60 y 120, La Plata 1900, Argentina.
Instituto de Investigaciones Fisicoquìmicas Teóricas y Aplicadas (INIFTA), CCT La Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de La Plata (UNLP), Diagonal 113 y 64 S/N, La Plata 1900, Argentina.
J Fungi (Basel). 2025 Jan 28;11(2):101. doi: 10.3390/jof11020101.
The ability of entomopathogenic fungi, such as , to infect insects by penetrating their cuticle is well documented. However, some insects have evolved mechanisms to combat fungal infections. The red flour beetle (), a major pest causing significant economic losses in stored product environments globally, embeds antifungal compounds within its cuticle as a protective barrier. Previous reports have addressed the contributions of non-cuticular infection routes, noting an increase in mortality in beetles fed with conidia. In this study, we further explore the progression and dynamics of oral exposure in the gut of after feeding with an encapsulated conidia formulation. First, we characterized the formulation surface using atomic force microscopy, observing no significant topological differences between capsules containing and not containing conidia. Confocal microscopy confirmed uniform conidia distribution within the hydrogel matrix. Then, larvae and adult insects fed with the conidia-encapsulated formulation exhibited distributed throughout the alimentary canal, with a higher presence of conidia before the pyloric chamber. More conidia were found in the larval midgut and hindgut compared to adults, but no germinated conidia were observed in the epithelium. These results suggest that the presence of conidia obstructs the gut, impairing the insect's ability to ingest, process, and absorb nutrients. This disruption may weaken the host, increasing its susceptibility to infections and, ultimately, leading to death. By providing the first direct observation of fungal conidia within the alimentary canal of , this study highlights a novel aspect of fungal-host interaction and opens new avenues for advancing fungal-based pest control strategies by exploiting stage-specific vulnerabilities.
诸如[具体真菌名称未给出]等昆虫病原真菌通过穿透昆虫表皮来感染它们的能力已有充分记载。然而，一些昆虫已经进化出对抗真菌感染的机制。赤拟谷盗（[具体拉丁学名未给出]）是一种在全球储存产品环境中造成重大经济损失的主要害虫，它在其表皮内嵌入抗真菌化合物作为保护屏障。先前的报告已经探讨了非表皮感染途径的作用，指出喂食分生孢子的甲虫死亡率有所增加。在本研究中，我们进一步探究了用包囊化的[具体真菌名称未给出]分生孢子制剂喂食后，[赤拟谷盗学名未给出]肠道内口服暴露的进程和动态。首先，我们使用原子力显微镜对制剂表面进行了表征，观察到含有和不含有分生孢子的胶囊之间没有显著的拓扑差异。共聚焦显微镜证实分生孢子在水凝胶基质中分布均匀。然后，喂食分生孢子包囊制剂的幼虫和成虫在整个消化道中均呈现[分生孢子分布情况未明确]，在幽门腔之前分生孢子的存在量更高。与成虫相比，在幼虫中肠和后肠中发现了更多的分生孢子，但在上皮细胞中未观察到萌发的分生孢子。这些结果表明分生孢子的存在阻塞了肠道，损害了昆虫摄取、处理和吸收营养的能力。这种破坏可能会削弱宿主，增加其对感染的易感性，并最终导致死亡。通过首次直接观察[赤拟谷盗学名未给出]消化道内的真菌分生孢子，本研究突出了真菌与宿主相互作用的一个新方面，并通过利用特定阶段的脆弱性为推进基于真菌的害虫控制策略开辟了新途径。
