bacteriolysis

Bacteriolysis is the rupture of bacterial cells that results in death and the release of cytoplasmic contents into the surrounding medium. It occurs when the cell envelope is compromised to the point that osmotic pressure causes the cell to swell and burst.

Causes and mechanisms include enzymatic degradation of the cell wall by lysozyme; inhibition of cell wall synthesis by beta-lactam antibiotics; lytic activity delivered by bacteriophages through endolysins and holins; autolysins produced by the bacteria themselves during growth or stress; and immune system–mediated lysis via mechanisms such as the membrane attack complex. Osmotic lysis occurs when the environment is hypotonic and the weakened cell wall cannot contain the internal turgor pressure. The susceptibility of bacteria to lysis varies with species and cell wall structure, such as differences between Gram-positive and Gram-negative organisms.

Consequences and significance include the rapid death of the bacterium and the release of intracellular components, which can provoke inflammatory responses. Release of endotoxins from Gram-negative bacteria is a notable concern during lysis. In research and clinical contexts, bacteriolysis is exploited in phage therapy and antibiotic action, but it can also complicate diagnostic assessments and patient outcomes when uncontrolled lysis occurs.

See also: lysozyme, beta-lactam antibiotics, bacteriophages, complement system.