Abstract
Helicobacter pylori (Marshall & Goodwin) is a widespread human pathogen that is acquiring resistance to the antibiotics used to treat it. This increasing resistance necessitates a continued search for new antibiotics. An antibiotic source that shows promise is animals whose immune systems must adapt to living in bacteria-laden conditions by producing antibacterial peptides or small molecules. Among these animals is the black soldier fly (BSF; Hermetia illucens Linnaeus), a Diptera that colonizes decomposing organic matter. In order to find anti-H. pylori peptides in BSF, larvae were challenged with Escherichia coli (Enterobacteriales: Enterobacteriaceae). Small peptides were extracted from hemolymph and purified using solid-phase extraction, molecular weight cutoff filtration and two rounds of preparative high performance liquid chromatography (HPLC). The anti-H. pylori fraction was followed through the purification process using the inhibition zone assay in brain-heart infusion agar, while peptides from uninoculated larvae had no activity. The inhibition halo of the active sample was comparable to the action of metronidazole in the inhibition zone assay. The purified sample contained four peptides with average masses of approximately 4.2 kDa that eluted together when analyzed by HPLC-mass spectrometry. The peptides likely have similar sequences, activity, and properties. Therefore, BSF produces inducible antibacterial peptides that have in vitro activity against H. pylori, which highlights BSF’s position as an important target for further bioprospecting.
Highlights
Helicobacter pylori is a Gram-negative pathogenic bacterium that infects about half of the world’s population (Zamani et al 2018) and is a causative agent of chronic progressive gastric inflammation, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma (Peek and Crabtree 2006, Wroblewski et al 2010)
At present only two antimicrobial peptides (AMPs) have been isolated and characterized from black soldier fly (BSF) larvae: one displays activity against Gram-positive bacteria (Park et al 2015), the other acts against Gram-negative bacteria like Escherichia coli, Enterobacter aerogenes Hormaeche & Edwards (Enterobacterales: Enterobacteriaceae), and Pseudomonas aeruginosa Migula (Pseudomonadales: Pseudomonadaceae) (Park and Yoe 2017)
We find that BSF larval hemolymph is a source of many AMPs expressed both constitutively and by induction
Summary
Helicobacter pylori is a Gram-negative pathogenic bacterium that infects about half of the world’s population (Zamani et al 2018) and is a causative agent of chronic progressive gastric inflammation, peptic ulcers, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma (Peek and Crabtree 2006, Wroblewski et al 2010). An appealing target for bioprospecting is the saprophagous maggot of the black soldier fly (BSF; Hermetia illucens Linnaeus) This maggot is a warm-climate, nonpest insect that quickly colonizes decomposing matter (Sheppard et al 2002). These characteristics suggest it has a potent immune system and can produce antimicrobial substances like peptides (Park et al 2014, Choi et al 2018) against a broad spectrum of bacteria (Bahar and Ren 2013, Elhag et al 2017). An advantage of using peptides as antimicrobials is that they are effective against multidrug resistant bacteria (Chung and Khanum 2017). Considering the need for new anti-H. pylori compounds and that BSF seems to be a good source for novel antibacterials, we prospect for and characterize inducible AMPs that inhibit H. pylori using bioassaydirected isolation and mass spectrometry
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
