Results from a prospective in vitro study on the mecillinam (amdinocillin) susceptibility of Enterobacterales

Abstract

The activity of mecillinam (amdinocillin) was assessed in Enterobacterales (n 420) isolated from urine samples between 2016 and 2017. Mecillinam susceptibilities were 97.4% in Escherichia coli isolates (294/302), 89.7% in Klebsiella spp. isolates (52/58), and 93.3% in Proteus mirabilis isolates (28/30). Among extended-spectrum -lactamase (ESBL) producers, 95.2% (99/104) were mecillinam susceptible, including two OXA-48-producing Klebsiella pneumoniae isolates. In Enterobacter spp. and Citrobacter spp., MICs were low (MIC50 0.5 mg/liter). In conclusion, the activity of mecillinam was high in Enterobacterales, even among multidrug-resistant isolates.