Question

Name that hemolysis: Clear zone around colony, may be narrow or wide, caused by the complete lysis of RBCs. e.g., Group A strep, group B strep, Listeria monocytogenes

1) Alpha hemolysis
2) Beta hemolysis
3) Gamma hemolysis
4) Delta hemolysis

Answer 1

The clear zone around a bacterial colony caused by complete lysis of RBCs is known as beta-hemolysis, characteristic of certain bacteria including Group A and B strep, as well as Listeria monocytogenes.

Step-by-step explanation:

The hemolysis described with a clear zone around the colony, caused by the complete lysis of red blood cells (RBCs), is known as beta-hemolysis. This type of hemolysis is seen with certain bacterial species such as Group A strep, Group B strep, and Listeria monocytogenes. Examples include the pathogenic Streptococcus pyogenes, which is part of the Lancefield Group A and is known to be ß-hemolytic, as well as L. monocytogenes, a bacteria that can cause serious infections in humans and also exhibits beta-hemolysis on blood agar plates.