Insect Model Hosts in Bacteriology: Innate Immunity and Host–Pathogen Interactions

Bacteria are integral associates of insects, contributing significantly to their tremendous diversity and ecological success. Consequently, insects have emerged as a powerful model organism for investigating novel aspects of bacterial-host interactions. In particular, the larvae of Galleria mellonella (the greater wax moth) and other insect species have emerged as valuable non-mammalian model systems for studying bacterial pathogenesis and host innate immune responses.

Insects as model hosts offer a range of practical and scientific advantages: they are inexpensive, easy to maintain, ethically straightforward under the 3Rs framework for animal research, and possess innate immune systems with considerable functional homology to those of vertebrates, including phagocytic haemocytes, humoral antimicrobial peptide responses, and melanisation cascades. Critically, they recapitulate key features of bacterial infection - including host lethality, bacterial burden, and immune activation - for a wide range of human and veterinary pathogens.

Work with G. mellonella and related hosts has provided critical insights into the virulence of Listeria monocytogenes, uropathogenic E. coli, Mycobacterium species, and Pseudomonas aeruginosa, among others. Emerging research is also revealing the role of epigenetic mechanisms and small RNA regulation - including miRNAs - in modulating insect responses to bacterial infection, as well as the use of insect models to evaluate the in vivo efficacy of novel antimicrobial compounds. Despite this progress, the field would benefit from greater standardisation of methodologies, and more systematic comparison of insect model findings with mammalian infection data. Furthermore, there is a critical need to expand the scope of these models to address emerging research frontiers, including antimicrobial resistance and the impacts of climate change.

This Research Topic aims to highlight and advance the use of insect model hosts in bacteriology research, with a focus on innate immune mechanisms, host–pathogen interaction dynamics, and the application of insect models to translational antimicrobial research.

Articles of interest may cover, but are not limited to, the following themes:

- Innate immune responses to bacterial infection in G. mellonella and other insect hosts
- Bacterial virulence factor characterisation using insect infection models
- Epigenetic and non-coding RNA regulation of insect immunity during bacterial infection
- Comparative studies of insect and mammalian infection models for the same pathogen
- Gut microbiome homeostasis and disruption during bacterial infection in insect hosts
- Use of insect models for evaluating novel antimicrobial compounds and therapeutic candidates
- Methodological advances and standardisation in insect infection model research

We welcome original research articles, methods papers, reviews, and perspectives.

If you are interested in submitting or have any questions, please contact the journal email: bacteriology@frontiersin.org.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Case Report
• Classification
• Clinical Trial
• Editorial
• FAIR² Data
• General Commentary
• Hypothesis and Theory
• Methods
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Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Case Report
• Classification
• Clinical Trial
• Editorial
• FAIR² Data
• General Commentary
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• Perspective
• Review
• Systematic Review
• Technology and Code

Keywords: Galleria mellonella, Insect model hosts, Innate immunity, Host-pathogen interactions, Bacterial pathogenesis, Antimicrobial peptides, Virulence factors, miRNA regulation, Antimicrobial compound screening, Gut microbiome

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.