Cornmeal-induced resistance to ciprofloxacin and erythromycin in enterococci

► In an ecosystem model, adding different doses of cornmeal led to enterococci resistant to ERY and CIP. ► The dose of cornmeal was related to the emergence of the CIP resistance phenotype and the maintenance time. ► The ERY resistance phenotype appeared later than that of CIP. ► In the ecosystem model, enterococci resistant to CIP were not promoted by a gyrA gene mutation. ► In the ecosystem model, enterococci resistant to ERY were largely promoted by the ermB resistance gene.