Cluster analysis on multiple drugs susceptibility supplements genotyping of methicillin-resistant Staphylococcus aureus☆

Abstract Objective: To evaluate the typing power of cluster analysis of antimicrobial susceptibility. Methods: Results of pulsed-field gel electrophoresis in 71 strains of meth icillin-resistant Staphylococcus aureus were compared with cluster analysis of the diameter of growth inhibition in 11 drugs. Subjects were a consecutive series of patients (n = 71) from the wards and outpatient units of a community teaching hospital. Results: The cluster analysis took 2 to 3 seconds once the data were entered into a computer. The sensitivity, specificity, and accuracy of the cluster analysis were 76.3%, 58.3%, and 73.2%, respectively, using genotyping as the reference. Conclusions: The cluster analysis offered real-time epidemiologic data at minimal cost and labor, warranting its cost-effective role.