What does Vi antigen do?

Vi antigen capsule is implicated in the evasion of the innate immune system (reviewed in ref. 3). The production of Vi antigen reduces serum complement binding/killing and promotes intracellular replication; Vi antigen-deficient mutants are 10,000-fold less virulent in a mouse model of infection (4).

What is Vi antigen in Salmonella?

Vi capsular polysaccharide (Vi) is a major virulence factor of human typhoid-causing pathogen Salmonella enterica serovar Typhi (S. Typhi). It distinguishes S. Typhi from closely related non-typhoidal Salmonella serovars such as S. Typhimurium which do not normally cause systemic infection in humans.

Where is Salmonella typhi from?

Salmonella Typhi bacteria are shed in the urine or stool of infected persons. Salmonella Typhi is spread by eating or drinking contaminated food or water or by contact with stool from infected persons.

What is flagellar antigen?

The O antigen, also called somatic antigen, is the polysaccharide portion of the outer membrane liposaccharide and the H antigen, also called flagellar antigen, is the protein flagellin that makes the filaments of the bacterial flagellum.

What is H substance in blood group?

Also known as substance H, H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay Blood phenotype (see hh blood group) Histocompatibility antigen, a major factor in graft rejection.

Which antibiotic is good for typhoid?

Antibiotic therapy is the only effective treatment for typhoid fever….Commonly prescribed antibiotics include:

  • Ciprofloxacin (Cipro).
  • Azithromycin (Zithromax).
  • Ceftriaxone.

What is Typhi O and 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.