Farmed insects can offer an environmentally sustainable aquafeed or livestock feed ingredient. The value of black soldier fly (Hermetia illucens) (BSF) larvae could be improved by enrichment in omega-3 through the dietary inclusion of seaweed. However, the industry practice of drying seaweed at low temperatures to retain nutritional properties may benefit the survival of human pathogenic bacteria, particularly if the seaweed has been harvested from contaminated water. Here we have demonstrated that E. coli and E. coli O157:H7 died-off in seaweed dried at 50 °C, although both were detected in the dried powder following 72 h storage. V. parahaemolyticus fell below the level of detection in stored seaweed after drying at ≥ 50 °C, but L. monocytogenes remained detectable, and continued to grow in seaweed dried at ≤60 °C. Therefore, drying seaweed at low temperatures risks pathogen carry-over into insects destined for animal feed. BSF larvae reared on an artificially contaminated seaweed-supplemented diet also became contaminated by all four bacteria present in the supplement. Water quality at seaweed harvesting sites, seaweed desiccation, and insect rearing practices, represent critical points where development of regulatory standards could achieve targeted control of pathogenic hazards.

养殖昆虫可提供环境可持续的水产饲料或家畜饲料成分。可以通过在饮食中添加海藻来富含omega-3，从而提高黑蝇（Hermetia illucens）（BSF）幼虫的价值。但是，在低温下干燥海藻以保持营养特性的工业实践可能有益于人类病原菌的生存，特别是如果海藻是从污染水中收获的。在这里，我们证明了大肠杆菌和O157：H7大肠杆菌在50°C干燥的海藻中会死亡，尽管在72 h储存后的干燥粉末中都检测到了两者。≥50°C干燥后，副溶血弧菌在储存的海藻中降至检测水平以下，但是单核细胞增生李斯特菌仍可检测到，并在≤60°C干燥的海藻中继续生长。因此，在低温下干燥海藻有可能将病原体带入要用作动物饲料的昆虫中。用人工污染的海藻补充饮食饲养的BSF幼虫也被补充物中存在的所有四种细菌污染。海藻收获场的水质，海藻干燥和昆虫饲养方法代表了关键点，在这些关键点上，制定监管标准可以实现对病原性危害的目标控制。