Evaluation of accuracy and applicability of RAISUS S4 system for testing antimicrobial drug susceptibility of staphylococci

Abstract

The rapid detection of antimicrobial drug-resistant strains, especially methicillin-resistant Staphylococcus aureus (MRSA), is important for the effective treatment and control of infectious diseases. In this study, we evaluated the applicability of the automatic analyzer RAISUS S4 system. The susceptibilities of 57 strains, including 18 MRSA strains, 21 MSSA strains, and 18 MR coagulase-negative staphylococcal strains, to antibiotics were measured using the RAISUS S4 system with the RAISUS plate RSMP, and the results were compared with those obtained using the DP panel as the reference method. The rates of agreement within ±1 dilution ranged from 86.0% to 100%, and those of category agreement ranged from 91.2% to 100%. In addition, we detected methicillin-resistant strains only 6.5 hours after the start of culture. In conclusion, the RAISUS S4 system was found to be useful for reducing the turnaround time for reporting methicillin-resistant strains and for choosing the appropriate drugs for the treatment of infectious diseases caused by staphylococcal strains.