Widal’s Reaction Results

1. Widal’s Reaction Results

2. 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 or other salmonella infection.

3. Analysis H抗体与O抗体的性质及其消长的意义 体内出现情况 抗体类型 与正常值比较 出现较早 维持时间短 O抗体 IgM 高 高 低 出现较晚 维持时间长 H抗体 IgG 高 低 高 感染早期 预防接种 非特异性回忆反应 伤寒的可能性很大 O凝集的交叉反应

4. 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 serum which appears (++) bacteria agglutination.

5. Experiment five Isolation and Identification of influenza virus

6. 病毒感染的微生物学检查法 • In general, diagnostic tests can be grouped into 3 categories: • direct detection • indirect examination (virus isolation) • serological methods

7. 流感病毒的分离鉴定 • Purpose： • To obtain information about microbiological diagnosis methods of influenza virus • Procedure • Acquiring and managing specimen • Isolation and Identification of influenza virus • serological diagnosis of influenza virus

8. 流感病毒的分离鉴定 • 标本采集和处理 • Throat washing or gargling are obtained within 3 days after infection • Test at once or stored frozen. • Centrifuge the washings 15 min at 3000 rpm, Harvest 1 ml of supernatant. • Add antibiotic to prevent bacterial contamination.

9. Patient’s serum Throat washings or gargling Treated with penicillin and streptomycin 血凝抑制实验 Embryonated egg inoculation (amniotic or allantoic route) Harvest amniotic and allantoic fluids Hemagglutination test + - Hemagglutination inhibition test complement fixation test Inoculate to fresh embryos after two such passages the result is negative

10. Hemagglutination test, HT • MATERIALS • Virus: the allantoic fluid that contains influenza virus; • physiological saline; • 0.5% chicken RBC suspension. • 20-well plastic disposable microtiter plates and glass pipettes.

11. Hemagglutination test, HT Materials well No. (ml)1 2 3 4 5 6 7 8 9 10 Saline 0.45 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Virus 0.05 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 弃 Dilution 1:10 1:20 1:40 1:80 1:160 1:3201:6401:12801:2560 con 0.5%RBC 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 incubate the plate at room temperature for 30 to 60 min. Check the agglutination.

12. Hemagglutination test (HT) • Results Record the hemagglutination as the followings: ++++ : All the RBC had been agglutinated. +++ : 75% of RBC had been agglutinated ++ : 50% of RBC had been agglutinated. + : 25% of RBC had been agglutinated. - : No RBC was agglutinated.

13. Hemagglutination inhibition test (HIT) • MATERIALS • Patient’s serum: deactivated 30 min at 56℃; • influenza virus: 4 HA units; • 0.5% chicken RBC suspension; • physiological saline • 20-well microtiter plates, pipettes and tubes.

14. Materials well No. (ml)1 2 3 4 5 6 7 8 9 10 Saline 0.9 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 Serum 0.1 0.25 0.25 0.25 0.25 0.25 0.25 弃 0.25 - Dilution 1:10 1:20 1:40 1:80 1:160 1:320 1:640 - - - Virus 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 - - Mix evenly incubation at 37℃ for 1h 0.5%RBC 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 - 0.25 Mix evenly incubation at 20℃ for 1 h Result - - - + ++ +++ ++++ ++++ - - 弃

16. Hemagglutination inhibition test (HIT) • RESULT Assess hemagglutination as above, the hemagglutination inhibition (HI) titer is the reciprocal of the highest dilution of the patient's serum which shows complete inhibition of agglutination.