How do you diagnose Salmonella infection

Diagnosis of Salmonella infection is undertaken by

a) Isolation of Salmonella -

  • Salmonella isolated using blood culture, organisms are isolated from blood stream at all stages of infection
  • Salmonella species are isolated mostly from 2nd week and 3rd week from stool and urine samples respectively.
  • Faeces and Urine are centrifuged and the deposits are enriched in Selenine F broth followed by inoculation in to Selective media Deoxycholate Citrate Agar (DCA)
  • The colonies are tested for presence of Salmonella 'O' and 'H' antigens by slide agglutination test, followed by biochemical testing.

b) Widal test : -

  • Widal test is done to detect Salmonella antibodies in the blood of infected person. Specific O and H antibodies of Salmonella are detected in blood.
  • Detection of Vi antibodies in the serum is diagnostic for Salmonella chronic carriers.
  • Fourfold increase in antibody level is used for confirming Salmonella infection.


dr.deepakdayama Thursday, May 21, 2009


Akinbode S.A Friday, February 6, 2009

what is salmonella paratyphi A and B and the possible causes

mohammed ali Friday, December 5, 2008

thank you

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