# Long-Chain Hydrocarbons in the Mucous Layer of the Galleria mellonella Insect Eggs as Potential Antibacterial Agents against Multidrug-Resistant Bacteria

## TL;DR

This study explores how Galleria mellonella insect eggs produce long-chain hydrocarbons that may act as antibacterial agents against drug-resistant bacteria.

## Contribution

The study pioneers the discovery of broad-spectrum antibacterial activity in Galleria mellonella egg mucous layers against multidrug-resistant bacteria.

## Key findings

- Galleria mellonella egg mucous layer extracts showed antibacterial activity against multidrug-resistant bacteria.
- Exposure to Gram-positive bacterial antigens enhanced the antibacterial efficacy of the egg extracts.
- Dotriacontane and tetracontane were identified as key volatile compounds in the extracts.

## Abstract

Natural products represent a vital source of chemical
entities
for the development of anti-infective agents. Insects face constant
threats from pathogens and have evolved diverse mechanisms of the
infection response. Among various insect species, the chemical protection
provided by Galleria mellonella eggs
against microorganisms remains poorly understood. This study aimed
to investigate whether G. mellonella produces chemical compounds that could serve as anti-infective agents
against clinically important bacteria. Additionally, the study examined
the effects of larval exposure to bacterial antigens from multidrug-resistant Staphylococcus aureus, Klebsiella
pneumoniae, and Pseudomonas aeruginosaon the chemical composition, morphology, and anti-infective properties
of the eggs. Larvae were challenged with antigens derived from multidrug-resistant
Gram-positive and Gram-negative bacteria. Eggs from intragroup mating
were collected and analyzed by using histological and physicochemical
techniques, including field-emission gun scanning electron microscopy,
energy-dispersive X-ray spectroscopy, and Fourier-transform infrared
spectroscopy. Antibacterial and antibiofilm activities of the egg
extracts were assessed using broth microdilution and crystal violet
assays, respectively. The volatile compound profile of the extracts
was characterized by gas chromatography–mass spectrometry.
This pioneering study demonstrates the broad-spectrum antibacterial
activity of G. mellonella eggs against
clinically relevant bacteria. Notably, the antibacterial efficacy
of the mucous layer extract was significantly enhanced when larvae
were exposed to Gram-positive bacterial antigens. Dotriacontane and
tetracontane were identified as the predominant volatile compounds.
These findings highlight G. mellonella eggs as a promising source of bioactive compounds and underscore
the potential of long-chain hydrocarbons in the development of novel
antibacterial agents.