Galleria mellonella is a recognised model to study antimicrobial efficacy; however, standardisation across the scientific field and investigations of methodological components are needed. Here, we investigate the impact of weight on mortality following infection with Methicillin-resistant Staphylococcus aureus (MRSA). Larvae were separated into six weight groups (180–300 mg at 20 mg intervals) and infected with a range of doses of MRSA to determine the 50% lethal dose (LD50), and the ‘lipid weight’ of larvae post-infection was quantified. A model of LD50 values correlated with weight was developed. The LD50 values, as estimated by our model, were further tested in vivo to prove our model. We establish a weight-dependent LD50 in larvae against MRSA and demonstrate that G. mellonella is a stable model within 180–260 mg. We present multiple linear models correlating weight with: LD50, lipid weight, and larval length. We demonstrate that the lipid weight is reduced as a result of MRSA infection, identifying a potentially new measure in which to understand the immune response. Finally, we demonstrate that larval length can be a reasonable proxy for weight. Refining the methodologies in which to handle and design experiments involving G. mellonella, we can improve the reliability of this powerful model.

中文翻译：

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当感染耐甲氧西林金黄色葡萄球菌时，Galleria mellonella 幼虫表现出与体重相关的致死剂量

Galleria mellonella 是公认的研究抗菌功效的模型；但是，需要整个科学领域的标准化和方法学组成部分的调查。在这里，我们调查了体重对耐甲氧西林金黄色葡萄球菌 (MRSA) 感染后死亡率的影响。将幼虫分成六个体重组（180-300 mg，间隔 20 mg）并用一系列剂量的 MRSA 感染以确定 50% 致死剂量（LD50），并量化感染后幼虫的“脂质重量” . 开发了与体重相关的 LD50 值模型。我们的模型估计的 LD50 值在体内进一步测试以证明我们的模型。我们在针对 MRSA 的幼虫中建立了体重依赖性 LD50，并证明 G. mellonella 是 180-260 mg 范围内的稳定模型。我们提出了多个与重量相关的线性模型：LD50、脂质重量和幼虫长度。我们证明了 MRSA 感染导致脂质重量降低，从而确定了一种潜在的新措施来了解免疫反应。最后，我们证明幼虫长度可以作为体重的合理代表。改进处理和设计涉及 G. mellonella 的实验的方法，我们可以提高这个强大模型的可靠性。