Lysozyme is a cornerstone of innate immunity. The canonical mechanism for bacterial killing by lysozyme occurs through the hydrolysis of cell wall peptidoglycan (PG). Conventional type (c-type) lysozymes are also highly cationic and can kill certain bacteria independently of PG hydrolytic activity.

What kind of bacteria does lysozyme kill?

In vitro, lysozyme is generally considered effective against some Gram-positive bacteria, but ineffective against Gram-negative bacteria [19]. However, lysozyme, perhaps indirectly, can affect Gram-negative bacteria in vivo [11, 20].

Does lysozyme kill Gram-positive bacteria?

Lysozyme degrades peptidoglycan in the bacterial cell wall leading to rapid killing of Gram-positive organisms; however, this mechanism cannot account for the protective effect of lysozyme against Gram-negative bacteria.