Banfi Davide, Bianchi Tommaso, Mastore Maristella, Brivio Maurizio Francesco
Laboratory of Applied Entomology and Parasitology, Department of Theoretical and Applied Sciences (DiSTA), University of Insubria, 21100 Varese, Italy.
Insects. 2024 Aug 16;15(8):618. doi: 10.3390/insects15080618.
The aim of this work was to develop an experimental protocol for the infection of with Gram-positive bacteria. Some physiological characteristics of these insects are comparable to those of vertebrates, therefore allowing the replacement of mammals in the preclinical phases of drug development. Linnaeus 1758 (Lepidoptera: Pyralidae) is accepted as an alternative model for the study of infectious diseases. Since data on infection procedures with different bacterial strains are scarce and sometimes conflicting, also due to different and non-uniform protocols, we developed an experimental protocol that would allow for controlled and repeatable infections, using the Gram-positive bacterium GRAS (Generally Regarded As Safe) . After analyzing the morphology and defining the growth rate of , doses of between 10 and 10 CFU/larvae were administered to late-stage larvae. The survival rate of the larvae was monitored up to 7 days and the LD determined. The bacterial clearance capacity of the larvae after injection with 10 and 10 CFU/larvae was assessed by hemolymph bacterial load analysis. The results made it possible to define the growth curve of correlated with the CFU count; based on the LD (10 CFU/larvae) calculated on the survival of , infections were carried out to evaluate the immune efficiency of the larvae in bacterial clearance. This protocol, standardized on larvae, could provide a functional tool to study the course of bacterial infections.
这项工作的目的是开发一种用革兰氏阳性菌感染[昆虫名称未给出]的实验方案。这些昆虫的一些生理特征与脊椎动物的相似，因此在药物开发的临床前阶段可以替代哺乳动物。1758年的林奈分类法（鳞翅目：螟蛾科）被认为是研究传染病的替代模型。由于关于不同细菌菌株感染程序的数据稀缺，有时还相互矛盾，这也是由于不同且不统一的方案所致，我们开发了一种实验方案，该方案使用革兰氏阳性菌GRAS（一般认为安全），能够实现可控且可重复的感染。在分析了[昆虫名称未给出]的形态并确定其生长速率后，给晚期幼虫施用10⁶至10⁸CFU/幼虫的剂量。监测幼虫的存活率直至7天，并确定LD₅₀。通过血淋巴细菌载量分析评估注射10⁶和10⁸CFU/幼虫后幼虫的细菌清除能力。结果使得能够确定与CFU计数相关的[昆虫名称未给出]的生长曲线；基于根据[昆虫名称未给出]的存活率计算出的LD₅₀（10⁸CFU/幼虫），进行感染以评估幼虫在细菌清除方面的免疫效率。这个以[昆虫名称未给出]幼虫为标准的方案，可以为研究细菌感染过程提供一个实用工具。
