1 Salmonella Filename Salmonella ppt 1222202 2 Salmonella

1 Salmonella Filename: Salmonella. ppt 12/22/202

2 Salmonella ä Nomenclature ä Incidence ä Clinical syndromes ä gastroenteritis ä typhoid fever 12/22/202

3 Salmonella ä ä 2, 000 serotypes Subgroup 1 ä ä S. cholerae-suis S. typhi S. enteritidis ä Human Pathogens ä ä Salmonella typhi Salmonella paratyphi subgroups 2 -5 ä ä cold-blooded animals environment 12/22/202

4 S. cholerae-suis: Transmission ä Humans to animals ä Animals to humans ä Humans and animals to animal feeds Large Inoculum: 106 12/22/202

5 Incidence in Ontario 1994 typhoid paratyphoid salmonellosis 1003 1992 6 85 639 1991 6 152 581 12/22/202

6 Salmonella: Clinical Syndromes ä Gastroenteritis ä Bacteremia: followed by gastroenteritis ä Enteric fever ä Asymptomatic colonization 12/22/202

7 Salmonella: Gastroenteritis ä incubation 6 -48 hrs. ä nausea, vomiting, diarrhea, fever, abdominal cramps, myalgia, headache ä 2 days - 1 week: usually spontaneous resolution 12/22/202

8 Mechanism of Pathogenicity Gastroenteritis ä ingestion ä absorbed to brush border of epithelial cells of small intestine and colon ä migrate to lamina propria, ileocaecal ä multiply in lymphoid follicles ä reticulendothelial hyperplasia and hypertrophy 12/22/202

9 Hyperplasia vs Hypertrophy ä Hyperplasia : abnormal increases in the number of normal cells (organ swells) ä Hypertrophy : increase in size of an organ 12/22/202

10 Salmonella: Bacteremia Usually caused by ä S. cholerae-suis ä S. typhi ä S. paratyphi ä S. dublin Complications ä osteomyelitis (10%) ä arthritis ä endocarditis Gram negative bacteremia is non-suppurative 12/22/202

11 Enteric Fever: S. typhi ä ileocaecal penetration ä intraluminal multiplication ä mononuclear response (macrophages) ä Salmonella remains alive ä 2 nd week - lymphoid hyperplasia (mesenteric lymph nodes) ä back to bowel 12/22/202

12 S. typhi ä found in stool - enteric media and selenite enrichment ä high antibodies 12/22/202

13 Mechanism of Fluid Secretion Stimulation ä Arachidonic acid with the enzyme cyclooxygenase stimulates the production of prostaglandin which then causes an increase in c. AMP (cyclic adenosine monophosphate) and stimulates fluid secretion. 12/22/202

14 Reduction of Fluid Secretion ä Anti-inflammatory drugs ä aspirin - non-steroidal, anti-inflammatory ä inhibits cyclo-oxygenase which is necessary to ä produce prostaglandins 12/22/202

15 The End 12/22/202