In vivo correlates of molecularly inferred virulence among extraintestinal pathogenic Escherichia coli (ExPEC) in the wax moth Galleria mellonella model system

Abstract

In contrast to commensal Escherichia coli, extraintestinal pathogenic E. coli (ExPEC) strains possess an array of virulence-associated genes. We sought to establish the feasibility of using the invertebrate Galleria mellonella (greater wax moth) for assessing ExPEC virulence and to investigate the correlation between genotypic determinants of virulence and in vivo pathogenicity. We observed a correlation between the number of virulence genes and larval survival, such that ExPEC isolates with higher virulence scores killed larvae significantly faster than isolates with lower virulence scores. By correlating genotypic and phenotypic virulence, we provide preliminary validation of this model for future studies investigating ExPEC virulence.

Keywords: :

• Escherichia coli
• Galleria mellonella
• ExPEC
• in vivo
• infection model
• virulence

This article is referred to by:

New to Galleria mellonella

Disclosure of Potential Conflicts of Interests

J.R.J. has received grants or contracts from Merck, Rochester Medical, and Syntiron, and has patent applications regarding molecular tests for E. coli clonal groups. All other authors have no conflicts to report.

Acknowledgments

We thank the staff of the Clinical Microbiology laboratory at Auckland District Health Board, New Zealand for performing antimicrobial susceptibility tests. D.A.W. is supported by a Clinical Research Training Fellowship from the Health Research Council (HRC) of New Zealand and S.W. by an HRC Sir Charles Hercus Fellowship (09/099). This material is based in part upon work supported by Office of Research and Development, Medical Research Service, Department of Veterans Affairs (J.R.J.).