Fate of Salmonella enterica Typhimurium and Listeria monocytogenes in Black Soldier Fly (Hermetia illucens) Larvae Reared on Two Artificial Diets

Foods. 2022 Jul 25;11(15):2208. doi: 10.3390/foods11152208.

Abstract

Ensuring food security is one of the main challenges facing the world over the next 30 years. There is, thus, an urgent need to significantly increase the supply of sustainable protein that can be transformed into animal feed. Proteins from insects offer a valuable alternative. This article presents the results of challenge tests conducted to investigate the dynamics of the microbial load of Salmonella enterica Typhimurium and Listeria monocytogenes in black soldier fly (Hermetia illucens) larvae grown on contaminated substrates. Four separate challenge tests were performed on two substrates: the Gainesville diet and a homemade diet. The challenge test procedure was carried out in accordance with ISO/DIS 20976-2 (under development). The results of this study show that, when grown on contaminated substrates, BSF larvae do not eliminate Salmonella Typhimurium or L. monocytogenes, but can reduce their microbial load. Sanitation processes downstream of the breeding of BSF larvae are, however, required to reduce the microbiological risks of this novel food.

Keywords: L. monocytogenes; Salmonella typhimurium; black soldier fly; insect; novel food.

Grants and funding

This research was funded by the Italian Ministry of Health, grant number PRC2019005:E54I19002740001 and grant number PRC2015005:E88C16000070001 and auto-funded by IZSLER:E52F17002320005.