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14. salmonella typhi
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- 3. MORPHOLOGY This gram-negativeenteric bacillus belongs to the family Enterobacteriaceae. It is a motile with peritrinchous flagella N0n- sporing Non capsulated Size varies from 2-4 X 0.6 mu m
- 4. CULTURAL CHARACTERISTICS Theyare aerobics, facultative anaerobes Growing optimum in the tempereture of 37 degree C and in the pH of 6-8.
- 5. NUTRIENT BROTH Afterovernight incubation at 37 degree C, uniform turbidity will be produced in the medium.
- 6. NUTRIENT AGAR MEDIUM Greyish white, circular colonies will be formed at 2-3mm diameter.
- 7. BLOOD AGAR MEDIUM Circular, smooth, convex colonies will be formed
- 8. MACCONKEY AGAR MEDIUM They produce pale yellow or colorless colonies with 1-3 mm diameter in size.
- 9. WILSON&BLAIR BISMUTH SULPHITE MEDIUM It is a selective medium for salmonella. The colonies will be black in color with metalic surface appearance.
- 10. XLD AGAR MEDIUM Red color colonies will be formed with black centres.
- 11. DEOXYCHOLATE CITRATE AGARMEDIUM It is also a selective medium for salmonella. In this colorless colonies will be produced after 24hrs of incubation
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- 13. Salmonella typhiand salmonella para typhi primarily cause infection in humans. Man acquires infection via oral route by ingestion of contaminated water or contaminated food. Typhoid fever can be caused by ingestion of a small number of bacilli but the para typhoid fever needs the consumption of large number of bacilli to produce infection.
- 14. The salmonellaproduces three important clinical diseases, ENTERIC FEVER SEPTICAEMIA SALMONELLA ENTEROCOLITIS
- 15. ENTERIC FEVER Itis usually caused by salmonella typhi (typhoid fever) and salmonella para typhi A,B and C (para typhoid fever)
- 16. TYPHOID FEVER On reachingthe gut via contaminated food or water the bacilli undergone through the following stages. Incubation phase Septicemia phase Localization phase
- 17. INCUBATION PHASE Itranges from 10-14 days When reaches the bacilli in the abdomen most of them will be destroyed, but some of them are revived and attaches to the epithelial cells of villi. These cells then enters to the mesentric lymph nodes and multiplication occurs. After multiplication the bacteria enters to the blood stream and causes primary infection.
- 18. SEPTICEMIA PHASE Duringthis stage the bacilli are entered to the gall bladder, spleen,liver bone marrow, lungs and kidney and the further multiplication occurs. After multiplication it enters to blood and causes secondary multiplication. During this time they produce toxins and causes fever and other symptoms.
- 19. LOCALIZATION PHASE Someof the fully grown bacilli will localized in the organs like liver, gall bladder, spleen etc and producing the toxins. So that the tissue becomes inflammed, undergo necrosis and results in typhoid ulcer. Later this ulcer leads to hemorrage and perforation.
- 20. EARLY ILLNESS Oncesigns and symptoms do appear, you're likely to experience: Fever that starts low and increases daily, possibly reaching as high as 104.9 F (40.5 C) Headache Weakness and fatigue Muscle aches Sweating Dry cough Loss of appetite and weight loss Abdominal pain Diarrhea or constipation Rash Extremely swollen abdomen
- 21. LATER ILLNESS Ifyou don't receive treatment, you may: Become delirious Lie motionless and exhausted with your eyes half-closed in what's known as the typhoid state
- 22. PARA TYPHOID FEVER Paratyphoid fever is mainly caused by salmonella para typhi A,B and C
- 23. PARA TYPHOID A In this the paratyphoid fever resembles typhoid fever but presents with more abrupt onset and mild symptoms. The features are fever, head ache, abdominal pain, malaise, anorexia, cough, hepatomegaly and splenomegaly.
- 24. PARA TYPHOID B It also causes paratyphoid fever. It may occur as typhoid like illness or severe gastro enteritis. Cold sores or fever blisters are frequently seen in this infection.
- 25. PARA TYPHOID C It is also causes paratyphoid disease. It is a rare type of infection.
- 26. SEPTICAEMIA It ismainly caused by S.paratyphi C. Infection occurs through oral route and bacilli enters to the blood stream. Growth and multiplication occurs in different body organs and causes pneumonia, osteomyelitis, pulmonary abscess, endocarditis and meningitis.
- 27. SALMONELLA ENTEROCOLITIS Itis otherwise known as salmonella food poisoning or gastroenteritis. It is also caused by the ingestion of contaminated food like egg, meat and sweets. Incubation period is 12-24 hours after that the symptoms will develop. Features are fever, vomiting, abdominal pain and diarrhea. Lasts for only few days Usually no complications occurs.
- 28. LABORATORY DIAGNOSIS Hematologicalinvestigations Bacteriological investigations Blood culture Clot culture Stool culture Urine culture duodenal juice or bile culture Biochemical tests Slide agglutination test Serological test
- 29. Hematological investigations Theleucocytes, lymphocyte and monocyte counts will be elevated.
- 30. Blood culture The blood should be collected before starting the treatment. Blood culture is positive in 80-90% of patients in first week. Culture result will get negative after 3 hours of administration of chloramphenicol.
- 31. Clot culture In this test 5ml of blood is allowed to clot. The clot is added to a bottle of bile broth containing streptokinase. Lysis of the clot and release of the clot will occur.
- 32. Stool culture Stool cultures will be positive during second week of illness. The stool sample is cultured in tetrathionate broth and incubated for 24 hrs, the growth of bacilli can be observed.
- 33. Urine culture Will be positive in second and third week of infection
- 34. Duodenal juiceor bile culture Performing to identify whether the bacilli are present over intestine or liver.
- 35. BIOCHEMICAL TESTS Sugarfermentation test: fermentation of glucose, maltose and dextrose will occur with the production of acids and gas. H2S test: positive Citrate utilization test: positive Iodole test: positive M.R test: positive
- 36. SLIDE AGGLUTINATION TEST The organism is placed in a microscopic slide and one drop of anti serum is added and mixed by tilting the slide. Clumping of the bacilli will occur within few minutes indicates a positive test.
- 38. SEROLOGICAL TEST Itinclude widal test and ELISA
- 39. TREATMENT Antibiotics likechloramphenicol, ampicillin and furazolidone are effective.