Rapid bacterial identification (ID) and antimicrobial susceptibility tests (AST) can have a significant impact on the management of infections, especially those caused by antibiotic-resistant bacteria (1, 2, 5). However, these rapid automated methods do not overcome the need for the preparation of a suspension of the organism at a fixed density (0.5 to 0.6 McFarland standard [MF]; 1.5 10 CFU/ml...