Pertaining to bacteria that counterstain pale red with Gram stain. These bacteria have a lipopolysaccharide (endotoxin) layer exterior to a thin peptidoglycan layer in the cell walls.
Losing the stain or decolorized by alcohol in Gram’s method of staining, a primary characteristic of bacteria having a cell wall composed of a thin layer of peptidoglycan covered by an outer membrane of lipoprotein and lipopolysaccharide.