In vitro fosfomycin study on concordance of susceptibility testing methods against ESBL and carbapenem-resistant Enterobacteriaceae

•88.6% ESBL E. coli and 76.0% carbapenemase K. pneumoniae susceptible to fosfomycin.•For ESBL-producing E. coli, the AD method showed CA of 100% with BMD and GT.•For KPC-producing K. pneumoniae, there were CA of 92% and 94 with BMD and GT.•The BD Phoenix system exhibits a CA > 90% for all isolates.•The AD method is the only reference method for carbapenem-resistant K. pneumoniae.