The Gram stain is typically the initial step in identifying bacteria and frequently dictates future identification methods. Misclassification may come from the tendency of some gram-positive rods to seem gram-variable or gram-negative, particularly members of the genera Bacillus, Erysipelothrix, Lactobacillus, and Listeria. In 1976, Cerney reported employing L-alanine-4-nitroanilide to identify cell-wall aminopeptidase, which was connected … Read more