Fitness of Escherichia coli mutants with reduced susceptibility to tigecycline.

ABSTRACT:

Objectives

The objective of this study was to determine the fitness of Escherichia coli mutants with reduced susceptibility to tigecycline after exposure to adverse conditions in vitro and in vivo.

Methods

Survival in response to low pH, bile salts, oxidative stress and human serum was examined for E. coli mutants with reduced susceptibility to tigecycline due to single mutations that caused increased efflux (marR, lon) or impaired LPS (rfaC, rfaE, lpcA). An in vitro competition assay was used to determine growth fitness defects. Competitive fitness was assessed using mouse infection models. MICs, exponential growth rates and expression levels of efflux-related genes were measured for genetically reconstructed double and triple mutants.

Results

The LPS mutants were 48

SUBMITTER: Linkevicius M 

PROVIDER: S-EPMC4830415 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature