SIG.b/InTheRes (ENVT-INRAE), Toulouse

Description:

In 2021, SIG.b started a collaboration with the Giraud team from InTheRes (ENVT-INRAE Toulouse).

Ciprofloxacin is an antibiotic of the fluoroquinolone (FQ) family whose primary target is DNA gyrase. Repeated exposure of a susceptible strain, Escherichia coli ATCC25922 to ciprofloxacin at therapeutic concentrations led to isolation of two tolerant mutants. Whole Genome Sequencing (WGS) of the mutants revealed point mutations in the gyrB gene, one of the two subunits of DNA gyrase.

Service Objectives:

Strain Reconstruction by Site-Directed Mutagenesis

– ATCC25922 is the reference strain for antibiograms but is not a laboratory strain; its transformability is low and was improved.

– We reintroduced into the parental strain the mutations obtained by experimental selection in order to verify that these Single Nucleotide Polymorphisms are readily responsible for resistance and tolerance phenotypes.

Funding:

The flat-rate fee and consumables were financed by the INRAE ​​team. The doctoral student from the INRAE ​​team was hosted for 6 months in the service to learn and carry out genetic experiments.

Associated publication:

Front Microbiol. 2022; doi: 10.3389/fmicb.2022.908296. Perault A, Turlan C, Eynard N, Vallé Q, Bousquet-Melou A and Giraud E (2022). Repeated Exposure of Escherichia coli to High Ciprofloxacin Concentrations Selects gyrB Mutants That Show Fluoroquinolone-Specific Hyperpersistence.