AUTHOR=Kay Sammy , Edwards Joseph , Brown Joseph , Dixon Ronald 

TITLE=Galleria mellonella Infection Model Identifies Both High and Low Lethality of Clostridium perfringens Toxigenic Strains and Their Response to Antimicrobials

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.01281

DOI=10.3389/fmicb.2019.01281

ISSN=1664-302X

ABSTRACT=<p>Research progress into mechanisms of the anaerobe <italic>Clostridium perfringens</italic> and associated diseases has been frustrated by the lack of reliable infection models. Wax moth larvae (<italic>Galleria mellonella</italic>) have emerged as a viable alternative to other models of infection since they are economic, survive at 37°C and require no specialist equipment. This study aims to establish to what extent <italic>G. mellonella</italic> larvae can be used to study the virulence of <italic>C. perfringens</italic> strains and its suitability for studying novel treatment strategies by an improved time-lapse approach to data collection. Mortality and morbidity rates of larvae challenged with 10<sup>5</sup> CFU of <italic>C. perfringens</italic> isolates from various sources were observed over 72 h and dose response data obtained. Phenoloxidase enzyme activity was investigated as a marker for immune response and tissue burden assessed by histopathological techniques. Results demonstrate that <italic>C. perfringens</italic> is pathogenic toward <italic>G. mellonella</italic> although potency varies dramatically between <italic>C. perfringens</italic> isolates and the reference strain ATCC 13124 was shown to be avirulent. Infection with <italic>C. perfringens</italic> strains activated the melanisation pathway resulting in melanin deposition but no increase in enzyme activity was observed. Efficacy of antibiotic therapy (penicillin G, bacitracin, neomycin, and tetracycline) administered parenterally to some extent correlates with that of <italic>in vitro</italic> analysis. The findings suggest <italic>G. mellonella</italic> might be a useful <italic>in vivo</italic> model of infection and convenient as a pre-screening assay for virulence of <italic>C. perfringens</italic> strains or as a simple, cheap and rapid <italic>in vivo</italic> assay in the first stage development of novel therapeutics against anaerobes.</p><sec><title>HIGHLIGHTS</title><list list-type="simple" prefix-word="simple"><list-item><label>–</label><p>Potential novel <italic>in vivo</italic> model for the study of <italic>Clostridium perfringens</italic> infection.</p></list-item><list-item><label>–</label><p>Novel time-lapse approach to data collection.</p></list-item><list-item><label>–</label><p>First report of the pathogenicity of <italic>C. perfringens</italic> toward <italic>G. mellonella</italic>.</p></list-item><list-item><label>–</label><p>First report of the efficacy of antibiotic therapy in response to <italic>C. perfringens</italic> infection in <italic>G. mellonella</italic>.</p></list-item></list></sec>