Serotype

Serotype a serotype is a closely related single species of microorganisms such as viruses or bacteria or a group of similar immune cells whose antigens are identical on the surface and can be used to isolate or type them. Therefore serotype is the separation of microorganisms with different surface antigens from the same species. For example, salmonella bacteria may look different under a microscope but may be divided into different serotypes based on the presence of surface antigens. Salmonella bacteria are called O-serotype if O-antigen is present on the surface of body cover and H-serotype if the H antigen is present in their flagella. The chemical composition of antigens also varies, such as O-antigen contains lipopolysaccharides, while the H antigen contains flagellar protein. Some serotypes are found only in one species or in a single place. Others are found in different animals and other parts of the world. Some serotypes can cause serious illness when they infect people, and others cause mild disease. To determine the serotype of a microorganism, it is necessary to determine which antigen is found on its surface. The bacterial antigen causes the infected person's immune system to produce specific antibodies that will kill this infectious microorganism. When mixed with a sample of a microorganism and its antigen and blood that contains its antibodies, it will form a clamp. Blood that contains specific antibodies is known as the antiserum. Making clamps when an antigen is mixed with its antibodies is called agglutination. [Md. Shahdat Hossain]