6 Serological diagnosis Samples:Widal’s test S. typhi and paratyphiWeil-Felix Test Richettsia(立克次体属)
7 Widal’s Reaction Definition: a specific reaction consisting in agglutination of typhoid bacilli or paratyphoid bacilli when mixed with serum from a patient having typhoid fever or other salmonella infection and constituting a test for the disease .Usage: to assist to diagnosis typhoid fever orother salmonella infection.
8 Materials Antigens: TO TH PA PB Antibody: serum of suspected patient Normal salineReaction plateStraws
9 PROCEDURE Reagent (ml) 1 2 3 4 5 6 7 Make the mark Add reagents as the following:Reagent (ml)SalinePatient serum discardSerum dilution 1:20 1:40 1: :160 1: :Bacteria suspensionFinal serum :40 1:80 1:160 1: :640 1:dilutionBacteria suspension: TO TH PA PBShaking several times, put it in 37℃ water bath for2 hours.Then let it stand at room temperature over night.
10 Judgment: Observation: 1. Control tube: no agglutination (-) 2. Lowest titer tube: absolutely agglutination (++++)3. Other tubes:three quarters agglutination(+++) half agglutination (++)one quarter agglutination (+) no agglutination (-)Judgment:Agglutination titer: the highest dilution of serumwhich appears (++) bacteria agglutination.