Galleria mellonella as an infection model to investigate virulence of Vibrio parahaemolyticus

ABSTRACT

Non-toxigenic V. parahaemolyticus isolates (tdh⁻/trh⁻/T3SS2⁻) have recently been isolated from patients with gastroenteritis. In this study we report that the larvae of the wax moth (Galleria mellonella) are susceptible to infection by toxigenic or non-toxigenic clinical isolates of V. parahaemolyticus. In comparison larvae inoculated with environmental isolates of V. parahaemolyticus did not succumb to disease. Whole genome sequencing of clinical non-toxigenic isolates revealed the presence of a gene encoding a nudix hydrolase, identified as mutT. A V. parahaemolyticus mutT mutant was unable to kill G. mellonella at 24 h post inoculation, indicating a role of this gene in virulence. Our findings show that G. mellonella is a valuable model for investigating screening of possible virulence genes of V. parahaemolyticus and can provide new insights into mechanisms of virulence of atypical non-toxigenic V. parahaemolyticus. These findings will allow improved genetic tests for the identification of pathogenic V. parahaemolyticus to be developed and will have a significant impact for the scientific community.

KEYWORDS:

• Vibrio parahaemolyticus
• nudix hydrolase
• MutT
• Galleria mellonella

This article is referred to by:

Galleria mellonella: A model of infection to discern novel mechanisms of pathogenesis of non-toxigenic Vibrio parahaemolyticus strains

Acknowledgements

We acknowledge Dr Konrad Paszkiewicz, Dr Karen Moore, Exeter DNA Sequencing Services and funding from Wellcome Trust Institutional Strategic Support Fund (WT097835MF), Wellcome Trust Multi User Equipment Award (WT101650MA) and Medical Research Council Clinical Infrastructure Funding (MR/M008924/1) for supporting whole genome sequencing of strains within this study. We also thank Florentina Papanicola and Nicole Needham for their help with gathering preliminary data to support this study.

Funding

None of the authors of this manuscript have any commercial or other association that might pose a conflict of interest. This work was partly supported by Wellcome Trust Institutional Strategic Support Fund (WT097835MF), Wellcome Trust Multi User Equipment Award (WT097835MF) Medical Research Council Clinical Infrastructure Funding (MR/M008924/1) and Biotechnology and Biological Sciences Research Council (BBSRC) funding (BB/N016513/1).