A mutator phenotype promoting the emergence of spontaneous oxidative stress resistant mutants in Campylobacter jejuni.

A mutator phenotype promoting the emergence of spontaneous oxidative stress resistant mutants in Campylobacter jejuni. Appl Environ Microbiol. 2017 Oct 13;: Authors: Dai L, Sahin O, Tang Y, Zhang Q Abstract Campylobacter jejuni is a leading cause of foodborne illnesses worldwide. As a microaerophilic organism, C. jejuni must be able to defend against oxidative stress encountered both in the host and in the environment. How Campylobacter utilizes a mutation-based mechanism for adaptation to oxidative stress is still unknown. Here we present a previously undescribed phenotypic and genetic mechanism that promotes the emergence of oxidative stress resistant mutants. Specifically, we showed that a naturally occurring mutator phenotype, resulting from a loss of function mutation in the DNA repair enzyme MutY, increased oxidative stress resistance (OX(R)) in C. jejuni We further demonstrated that MutY malfunction didn't directly contribute to the OX(R) phenotype, but increased the spontaneous mutation rate in the peroxide regulator gene perR, which functions as a repressor for multiple genes involved in oxidative stress resistance. Mutations in PerR resulted in loss of its DNA binding function and derepression of PerR-controlled oxidative stress defense genes, thereby conferring an OX(R) phenotype and facilitating Campylobacter survival under oxidative stress. These findings reveal a new mechanism that promotes the emergence of spontaneous ...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research