Why is flagellar antigen called H antigen?

Why is flagellar antigen called H antigen?

The bacteria’s surface are covered with lipopolysaccharide (LPS). The outermost portion of the LPS is the O antigen. Flagella are whip-like tails that bacteria use to move around. Flagella is the whole structure, while the slender threadlike portion of the flagella is called the H antigen.

What is H and O antigen?

O antigen and H antigen are two types of antigens used to determine the different serotypes of bacterial species. O antigen is a lipopolysaccharide found on the cell wall. H antigen is a proteinaceous antigen which is a part of the flagella.

What happens if H antigen is absent?

People who lack the H antigen do not suffer from deleterious effects, and being H-deficient is only an issue if they need a blood transfusion, because they would need blood without the H antigen present on red blood cells. Therefore, the H antigen is present more in blood type O and less in blood type AB.

What is H antigen function?

The Hh blood group contains one antigen, the H antigen, which is found on virtually all RBCs and is the building block for the production of the antigens within the ABO blood group. (A transfusion of “normal” group O blood can trigger a severe transfusion reaction.)

What is the difference between typhoid O and typhi H?

S typhi O positive means active infection of typhoid fever. Active infection indicates the patient has an infection of Salmonella enterica serovar typhi. S typhi H positive means there is a past infection or it shows the result of the immunized person’s serum test report.

What is the meaning of O and H in widal test?

Widal agglutination was introduced as a serologic technique to aid in diagnosis of typhoid fever. The test was based on demonstrating the presence of agglutinin (antibody) in the serum of an infected patient, against the H (flagellar) and O (somatic) antigens ofSalmonella typhi.