RT Book, Section A1 Mordorski, Breanne A1 Friedman, Adam J. A2 Kang, Sewon A2 Amagai, Masayuki A2 Bruckner, Anna L. A2 Enk, Alexander H. A2 Margolis, David J. A2 McMichael, Amy J. A2 Orringer, Jeffrey S. SR Print(0) ID 1161351963 T1 Gram-Negative Coccal and Bacillary Infections T2 Fitzpatrick's Dermatology, 9e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9780071837798 LK dermatology.mhmedical.com/content.aspx?aid=1161351963 RD 2024/10/11 AB The Gram stain, developed in the late 1800s by Hans Christian Gram, is used to distinguish 2 major categories of bacteria. Gram-positive bacteria retain the purple hue of the initial crystal violet stain, whereas Gram-negative bacteria are decolorized and subsequently stain red by safranin or carbol fuchsin. While Gram-positive bacteria have thick walls of peptidoglycan and secondary polymers that are relatively impermeable and resist decolorization, Gram-negative bacteria have a thin peptidoglycan layer with an outer lipid membrane bilayer that is readily disrupted by this process.1