Performance Evaluation of BD Phoenix and MicroScan WalkAway plus for Determination of Fosfomycin Susceptibility in Enterobacterales

Background: Fosfomycin is an old bactericidal drug that has gained increasing interest in the last decade for its potential use multi-drug resistant gram-negative infections. However, evidence on fosfomycin susceptibility testing reports a poor correlation between commercial methods vs. reference agar dilution (AD) Enterobacterales (EB). The study aimed at assessing performance of two automated systems determination EB clinical isolates. Methods: results collections 100 non-duplicate strains obtained using different platforms (BD Phoenix and MicroScan WalkAway Plus) were compared with those by AD. Categorical agreement (CA), major error (ME) very (VME) rates calculated. Results: BD exhibited 6.9% rate false-resistant achieved CA 69%, whereas Plus 3.7% 72% CA. Both showed detection isolates, 49.1% 56.2% false-susceptible Microscan Plus, respectively. Conclusions: Overall, remains most suitable method routine laboratory antimicrobial strains, given systems. application both systems, laboratories reporting fosfomycin, should be reviewed light accuracy falling below acceptable threshold.