Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is called a hemolysin.

2022年8月10日 · Hemolysis is the breakdown of red blood cells (RBC). A substance that causes hemolysis is a hemolysin. Brown (1919) introduced three terms alpha, beta and gamma to indicate three types of streptococci based on haemolytic reactions observed on blood agar plates.

Certain bacterial species produce extracellular enzymes that lyse red blood cells in the blood agar (hemolysis). These hemolysins (exotoxin) radially diffuse outwards from the colonies causing complete or partial destruction of the red cells (RBC) in the medium and complete denaturation of hemoglobin within the cells to colorless products.

2021年4月27日 · Based on hemolytic characteristics, streptococci were classified into β-hemolytic and non-β-hemolytic groups. In 1934, streptococci were further classified in the name of Lancefield grouping, based on the presence of group-specific wall polysaccharides on the bacterial surface.

2024年10月7日 · Blood agar plates are a fundamental tool in microbiology for identifying and differentiating bacterial species based on their hemolytic properties. These plates not only support the growth of various bacteria but also reveal distinct patterns of hemolysis that can be crucial for diagnosis and research.

2025年1月14日 · The distinctiveness of beta hemolysis makes it easier to identify and is often a focus in clinical diagnostics. Gamma hemolysis, or non-hemolysis, indicates no change in the blood agar surrounding the colonies. This pattern is observed in bacteria that do not produce hemolysins, such as Enterococcus faecalis.

2024年10月21日 · Different bacteria exhibit distinct hemolysis patterns, aiding identification. Molecular techniques, such as PCR assays, detect bacterial genes associated with hemolysin production, offering specificity and sensitivity.