Gram positive

Refers to the ability of a bacterium to resist decolorization with alcohol after being treated with Gram crystal violet stain, imparting a violet color to the bacterium when viewed by light microscopy

Description
Gram staining relies on retention in the bacterial cell wall. Although an important means of classifying bacteria, it has been superseded by more specific molecular methods for many purposes. Gram-positive infections are generally more easily controlled by &#946;-lactam antibiotics, such as penicillin, than infections with Gram-negative bacteria, owing to the greater antibiotic susceptibility of Gram-positive bacteria. While Gram-negative bacteria are generally more pathogenic to humans, Mycobacterium tuberculosis and other Gram-positive tuberculosis agents are notable exceptions. See Gram stain