Salmonella Long Essays
Question 1. Describe etiopathogenesis and clinical features and lab diagnosis of enteric fever.
Answer:
Enteric fever:
- Etiopathogenesis:
- Enteric Fever Includes:
- Typhoid fever – caused by salmonella typhi.
- Paratyphoid fever – caused by salmonella paratyphi.
- Enteric Fever Includes:
Virulence Factors:
1. Endotoxin.
- Causes diverse toxic manifestations of enteric fever.
Read And Learn More: Microbiology Question and Answers
2. Exotoxin – enterotoxin.
3. Capsule.
- Has anti-phagocytic activity.
Enteric Fever Clinical features:
- The incubation period is 7 – 14 days.
- Route of infection – contaminated food and water.
1. Typhoid Fever – Its Manifestations Include.
- Gradual illness
- Headache
- Anorexia
- Congestion of mucous membrane.
- Hepatosplenomegaly.
- Step-ladder pyrexia.
- Relative bradycardia.
- Leucopenia.
- Skin rashes called ‘Rose-spots’ appear during the second or third week.
2. Paratyphoid Fever.
- Symptoms are milder than typhoid fever.
- Septicaemia with suppurative complications occurs.
Lab Diagnosis Of Enteric Fever:
1. Isolation Of Bacilli.
- For isolation of bacteria, specimens are obtained from blood, feces, urine, aspirated duodenal fluid, bile, bone marrow or rose spot.
- These specimens are then cultured.
2. Demonstration Of Antibodies.
- Widal Test
- It is an agglutination for the detection of agglutinins H and 0 in patients with enteric fever
- Widal Test Method:
- Equal volumes (0.4 ml) of serial dilutions of serum from 1:10 to 1: 640 and H and 0 antigens are mixed.
- One control tube containing antigen and normal saline is used.
- All these tubes are incubated in a water bath at 37°C.
- Widal Test Results:
- Widal Test Interpretation:
3. Demonstration of Circulating Antigen.
- Done by counterimmunoelectrophoresis and ELISA.
Salmonella Short Essays
Question 1. Diseased caused by salmonella.
Answer:
Question 2. Antigenic structure of salmonella.
Answer:
Salmonella possesses three types of antigens.
