Giglio Fabiana, De Stefano Federica, Fusco Alessandra, Salvia Rosanna, Scieuzo Carmen, Cos Paul, Donnarumma Giovanna, Falabella Patrizia
Department of Basic and Applied Sciences, University of Basilicata, Via Dell'Ateneo Lucano 10, 85100, Potenza, Italy.
Department of Experimental Medicine, University of Campania "Luigi Vanvitelli," , Naples, NA, 80138, Italy.
Probiotics Antimicrob Proteins. 2025 Aug 7. doi: 10.1007/s12602-025-10697-x.
Antimicrobial peptides (AMPs) constitute a chemically and structurally heterogeneous family of molecules produced by a wide range of living organisms, including plants, fish, amphibians, mammals, and insects. Their expression is particularly high in hosts frequently exposed to microorganisms, where AMPs play a key role in innate immune responses. Insects represent one of the richest natural sources of AMPs. Over their long evolutionary history, they have developed a highly efficient immune system with AMPs playing a central role in defense against pathogens, enabling them to colonize various habitats. In recent years, interest in AMPs has significantly increased due to the emergence of antibiotic resistance, positioning these peptides as potential therapeutic alternatives for treating infections caused by multi-resistant pathogens. In this study, we investigated the antimicrobial activity of peptide fractions extracted from the hemolymph of Hermetia illucens larvae (Diptera, Stratiomyidae), an insect known for its high expression of AMPs. Larvae were injected separately with either Escherichia coli (Gram-negative) or Micrococcus flavus (Gram-positive), and hemolymph was collected 24 h post-infection, as well as from uninfected larvae. Antimicrobial activity was assessed through microbiological assays, including both agar diffusion tests and microdilution assays. Results demonstrated significant activity against pathogenic bacterial strains, including antibiotic-resistant ones. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined for each experimental condition. MIC values ranged from 0.023 to 0.375 µg·µL⁻, while MBC values ranged from 0.187 to 0.750 µg·µL⁻, depending on the bacterial strain and the infection treatment group. These findings demonstrate the potential of H. illucens-derived AMPs as effective agents against Gram-positive and Gram-negative bacteria, including resistant strains, and support their further development as alternatives or adjuvants to conventional antibiotics.
抗菌肽（AMPs）是一类化学和结构上异质的分子家族，由多种生物体产生，包括植物、鱼类、两栖动物、哺乳动物和昆虫。它们在经常接触微生物的宿主中表达特别高，在先天免疫反应中发挥关键作用。昆虫是AMPs最丰富的天然来源之一。在其漫长的进化历史中，它们发展出了高效的免疫系统，其中AMPs在抵御病原体方面发挥着核心作用，使它们能够在各种栖息地中生存。近年来，由于抗生素耐药性的出现，人们对AMPs的兴趣显著增加，这些肽被定位为治疗多重耐药病原体引起的感染的潜在治疗替代品。在本研究中，我们研究了从黑水虻幼虫（双翅目，水虻科）血淋巴中提取的肽组分的抗菌活性，黑水虻以其高表达的AMPs而闻名。分别向幼虫注射大肠杆菌（革兰氏阴性）或黄微球菌（革兰氏阳性），在感染后24小时收集血淋巴，以及未感染幼虫的血淋巴。通过微生物学测定评估抗菌活性，包括琼脂扩散试验和微量稀释试验。结果表明对包括耐药菌株在内的致病细菌菌株具有显著活性。针对每种实验条件确定了最低抑菌浓度（MIC）和最低杀菌浓度（MBC）。MIC值范围为0.023至0.375µg·µL⁻，而MBC值范围为0.187至0.750µg·µL⁻，具体取决于细菌菌株和感染治疗组。这些发现证明了黑水虻来源的AMPs作为对抗革兰氏阳性和革兰氏阴性细菌（包括耐药菌株）的有效剂的潜力，并支持它们作为传统抗生素的替代品或佐剂的进一步开发。
