as an Infection Model forSterne.

Abstract

Understanding bacterial virulence provides insight into the molecular basis behind infection and could identify new drug targets. However, assessing potential virulence determinants relies on testing in an animal model. The mouse is a well-validated model but it is constrained by the ethical and logistical challenges of using vertebrate animals. Recently the larva of the greater wax mothhas been explored as a possible infection model for a number of pathogens. In this study, we developedas an infection model forSterne. We first validated two different infection assays, a survival assay and a competition assay, using mutants containing disruptions in knownvirulence genes. We next tested the utility ofto assess the virulence of transposon mutants with unknown mutations that had increased susceptibility to hydrogen peroxide inassays. One of these transposon mutants also displayed significantly decreased virulence in. Further investigation revealed that this mutant had a disruption in the petrobactin biosynthesis operon (), which has been previously implicated in both virulence and defense against oxidative stress. We conclude thatcan detect attenuated virulence ofSterne in a manner consistent with that of mammalian infection models. Therefore,could serve as a useful alternative to vertebrate testing, especially for early assessments of potential virulence genes when use of a mammalian model may not be ethical or practical.