1 / 34

salmonella

salmonella. Pathogenesis. PATHOGENICITY OF SALMONELLAE. Clinical syndromes caused by Salmonellae in human beings: A. Enteric fever B. Gastroenteritis (food poisoning) C. Salmonella septicemia. ENTERIC FEVER.

dora
Download Presentation

salmonella

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. salmonella Pathogenesis..

  2. PATHOGENICITY OF SALMONELLAE • Clinical syndromes caused by Salmonellae in human beings: A. Enteric fever B. Gastroenteritis (food poisoning) C. Salmonella septicemia

  3. ENTERIC FEVER • The term ENTERIC FEVER includes 1. TYPHOID FEVER – caused by S typhi 2. PARATYPHOID FEVER – caused by S paratyphi A, B & C

  4. Contd.. • Enteric fever is endemic in all over India. • With a proportion of TYPHOID to PARATYPHOID A about 10 : 1. • Paratyphoid B is rare andParatyphoid C is very rare.

  5. Typhoid Fever • Typhoid fever, also known as typhoid • Other names:abdominal typhus, infantile remittant fever, slow fever, nervous fever, pythogenic fever, etc.

  6. Contd.. • Typhosin Greek means, smoke and typhus fever got its name from smoke that was believed to cause it. • Typhoid means typhus-like and thus the name given to this disease. • The term Typhoid was given by Louis (1829) to distinguish it from typhus fever. • Eberth described the typhoid bacillus in spleen sections and mesenteric lymph nodes from a patient who died from typhoid and Gaffky isolated it in pure cultures.

  7. Electron microscopy SALMONELLA

  8. Epidemiology

  9. WORLD WIDE DISTRIBUTION

  10. Contd.. • Source : Case of Typhoid or carriers in frequent. • Infective material : Contaminated food or water. • Route of infection : Ingestion of contaminated food or water.

  11. Carrier state.. • CARRIERS are more important in the transmission of the disease. • Types of carriers: 1. Convalescent carriers 2. Temporary carriers 3. Chronic carriers • Convalescent carriers shed bacilli in feces for 3 WEEKS to 3 MONTHS after clinical cure. • Temporary carriersshed bacilli for more than 3 MONTHS but less than A YEAR. • Chronic carriers shed bacilli for over A YEAR.

  12. Contd.. • 2-4 % of patients become Chronic carriers, esp. women over 40yrs. • Food handlers or cooks that become carriers are particularly dangerous. • The best known example was Mary Mallon, named for nick as TYPHOID MARY. • She caused at least 7 outbreaks in 15 yrs affecting over 200 people.

  13. in a 1909 newspaper illustration Mary Mallon

  14. Bacilli persist in gall bladder or kidney are shred out

  15. Pathogenesis • Median Infective Dose (ID50) is about 1 000 to 1 000 000 bacilli in human volunteers. • The course of organism in the body is as follows.

  16. Clinical Course.. • Incubation period is usually 7-14 days, but may range 3-56 days according to dose of infection. • Clinical course: From Mild Undifferentiated Pyrexia (AMBULANT TYPHOID) Rapidly fatal disease

  17. Clinical features.. • Gradual Onset of head ache malaise anorexia • Typical features: Step ladder pyrexia Relative bradycardia Toxemia

  18. Contd.. • A soft, palpable spleen is a constant finding • Hepatomegaly is also common • Rose spots that fade on pressure appear on skin during 2nd or 3rd week.

  19. Rose spots

  20. Bile is a good culture medium for the bacillus, it multiplies abundantly in GALL BLADDER INTESTINES involves the PAYERS PATCHES LYMPHOID FOLLICLES

  21. Causation

  22. Complications of the disease • Intestinal perforation • Hemorrhage • Circulatory collapse • Bronchitis or Bronchopneumonia is always found. • Psychoses • Meningitis • Cholecystitis • Arthritis • Abscesses

  23. Contd.. • Periostitis • Nephritis • Hemolytic anemia • Venous thromboses • Peripheral neuritis • Osteomyelitis is rare sequel.

  24. Convalescence & Relapse • Convalescence is slow • In 5-10% of cases relapse occurs during convalscence • Relapse rate is higher in patients treated early with Chloramphenicol.

  25. Paratyphoid fever • Resembles typhoid fever but is generally milder • Caused by S. paratyphi A and B, rarely by S. paratyphi C which is often associated with frank septicemia in supporative complications.

  26. Salmonella Gastroenteritis • Food poisoning. • Zoonotic disease. • Caused by any Salmonella except S. typhi. Pathogenic Species: 1. S typhimurium(most common) 2. S enteritidis

  27. Pathogenesis • Source: Poultry, Meat, Milk and its products, esp., Eggs and its products (as the bacteria can enter through the shell if eggs are contaminated and grow inside), uncooked vegetables. • Route: Ingestion • Gastroenteritis may occur without food poisoning as in cross infection in hospitals.

  28. Clinically.. • Short incubation period of 24hrs or less. • Featured by Diarrhea, Vomiting, Abdominal pain, Fever. • Diarrhea: May vary from one or more loose stools to an acute Cholera like • Usually subsides in 2-4 days resembles and dysentery.

  29. Salmonella Septicemia • Caused by: S choleraesuis • Focal supporative lesions: Osteomyelitiss, Deep abscesses, Endocarditis, Pneumonia, Meningitis.

More Related