2.3.The cards were read by kinetic fluorescence measurement, and the results reported within 3 h [7].A bacterial suspension of each isolate was prepared by mixing the bacterial colony growing on blood agar with 0.45% saline sodium chloride solution to obtain a concentration of 0.5-0.63 McFarland units using the VITEK DensiCHEK(TM) colorimeter (bioMerieux).Quality control for Vitek was done using Gram-positive bacteria (Enterococcus casseliflavus ATCC 700327 and Staphylococcus saprophyticus BAA-750) and Gram-negative bacteria (Enterobacter hormaechei ATCC 700323 and Stenotrophomonas maltophilia ATCC 17666).