Antimicrobial Activity of an Extract of Hermetia illucens Larvae Immunized with Lactobacillus casei against Salmonella Species

Abstract

The expressions of antimicrobial peptides (AMPs) in the larvae of the black soldier fly, Hermetia illucens, were significantly increased by pathogen or stimulant induced innate immunity activation. We immunized H. illucens fifth instar larvae with five different Lactobacillus species, that is, Lactobacillus acidophilus, L. brevis, L. casei, L. fermentum, or L. delbrueckii, to induce the mass production of AMPs and selected optimal immune inducers. Antimicrobial activities in hemolymph and H. illucens larvae (HIL) extract were evaluated against three salmonella species (Salmonella pullorum, Salmonella typhimurium, and Salmonella enteritidis). Highest antimicrobial activity was shown by the hemolymph of HIL immunized by L. casei and its activity was closely linked with the inductions of cecropin 1 (HiCec1) and defensin 1 (HiDef1) gene expressions. Furthermore, antimicrobial activity in hemolymph was stable to heat and pH and the growth of three Salmonella species were dramatically suppressed by HIL hemolymph and extract after immunization with L. casei. The minimal inhibitory concentration (MICs) of L. casei-immunized HIL extract against Staphylococcus aureus, Escherichia coli, and Salmonella species ranged from 100~200 µg/100 µL and no cytotoxicity to CaCo-2 and L929 cells were observed in the concentration range 100~40,000 µg/100 µL. Taken together, the present investigation demonstrates that L. casei-immunized HIL extract is a powerful natural antibiotic and preservative that can prevent contamination by Salmonella species.

Identification of Antimicrobial Property of Rat-Tailed Maggots Surviving in Pig Excreta

“…We found that, rat-tailed maggot hemolymph with the concentration of 25-30 µg /100 µl and 35-40 µg / 100 µl, respectively are enough to kill Escherichia coli and Salmonella typhimurium, respectively. Our ndings corroborated with earlier studies, identi ed the role of normal hemolymphs to kill different kinds of bacteria (Sahalan et al, 2006;Basseri et al, 2016;Hirsch et al, 2020;Lee et al, 2020).…”

Black Soldier Fly Full-Fat Larvae Meal as an Alternative to Fish Meal and Fish Oil in Siberian Sturgeon Nutrition: The Effects on Physical Properties of the Feed, Animal Growth Performance, and Feed Acceptance and Utilization

“…The observed improvements in growth performance may be interpreted mainly by the functional role of insect protein – containing AMP and fat composition—with high share of lauric acid as well as chitin prebiotic properties which are widely discussed in the literature [ 59 , 60 , 61 , 62 ]. AMP presence positively affects the microbiome, while the presence of high concentration of lauric acid (21 g/100 g of crude fat) may also play a key role in fish health—immune system stimulation, and microbiome stabilization also [ 62 ]. Moreover, considering the use of full-fat BSFL, and available sources of scientific knowledge on insect fat use [ 21 , 59 , 60 ], there is no confirmed data on negative effects of insect fat – even in total replacement cases.…”

“…The lack of differences in nutrient digestibility coefficients may be interpreted as the effects of a lower level of chitin in full-fat meals in comparison with defatted ones. Chitin in fish nutrition-depending on the dose-is considered as a prebiotic substance or antinutritive compound which may decrease feed palatability, nutrient digestibility, and growth performance [62][63][64][65][66]. It was considered an immunostimulant in the case of yellow catfish (Pelteobagrus fulvidraco) [67].…”

Preparation of Antioxidant and Antibacterial Chitosan Film from Periplaneta americana

“…Recently, insects have attracted researchers’ focuses because they possess extraordinarily huge biomass, and they are promising resources of protein, lipid, and chitin [ 1 ]. In addition, some species of insects provide special substances, like antimicrobial peptides, which make them more valuable [ 2 ]. The American cockroach ( Periplaneta americana ) is one of the world’s most thriving insects distributing in tropic, subtropic, and temperate regions.…”