Pathogenic Enteric Bacteria I

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Pathogenic Enteric Bacteria I

• Dr A. Aziz Djamal MSc.DTMH.SpMK(K)

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• Topics
• Escherichia .
• Vibrio
• Klebsiella
• Proteus
• Enterobacter

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• Escherichia
• Klebsiella
• Proteus
• Enterobacter
• All are member of Enterobacteriaceae family
• Rod shape
• Gram negative
• Facultative anaerob

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• Genus Vibrio belong to the family of Vibrionaceae
• Curve rod shape
• Gram negative
• Facultative anaerob
• One single polar flagel

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Escherichia coli

• Found by Theodor Escherich ( Austrian ) 1882
• Bacteria coli commune
• Normal inhabitant of intestinal human and warm
  blooded animal
• By the time proceed it is also in process of
  adaptation and change

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• It is used as standard for fecal contamination.
• Water quality for household purpose.
• MPN test / Index.
• Lactose fermenter

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Pathogenic strains

1. EPEC ( Enteropathogenic )
2. ETEC ( Enterotoxigenic )
3. EIEC ( Enteroinvasive )
4. EHEC( Enterohaemorrhagic )
5. EAEC ( Enteroadherent )

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Enteropathogenic E coli

• Infantile diarrhea
• Attachment to immature intestinal mucosal cells
• Destruction of mucosal villi
• Causing diarrhea followed by fever and icteric
• Fatal infection especially on neglected labor.

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Enterotoxigenic E. coli (ETEC)

• Produced Enterotoxin.
• Plasmid mediated enterotoxin production.
• There are 2 kind of Toxins Lt ( Labile toxin )
• 
  St ( Stable toxin)

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Lt ( Labile toxin )

• Big Molecule.
• Antigenic.
• Cross reaction with Cholera toxin.
• Activate Adenylate cyclase enzyme -- Cascade
  reaction-end product cyclic -5--AMP ( Adenosine
  Mono Phosphate )--Profuse watery diarrhea.
• Dehydration--Electrolyte and Acid-Base
  derangementmetabolic acidosis renal failure
  death.

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Stable toxin (St)

• Smaller molecule
• Non Antigenic.
• Activate Guadenylate cyclase enzyme
  systemcascade reactionend product cyclic 5
  GMP (Guadenosin Mono Phosphate ) Low quality
  energy resouces mild diarrhea.

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Enteroinvasive Escherichia coli (EIEC)

• Site of infection mucosal cells layer of Colon.
• Shigella like infection.
• Shiga like toxin toxic to colonic mucosal
  cells- necrosisulcersbleeding ( Blooded
  diarrhea), fever tenesmus ani ( Trias Bacillar
  Dysentery)

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Enterohemorrrhagic E coliEHEC

• Firstly dairy product contamination, meat on
  refrigeratorProduce toxin ( Shiga like toxin
  )strain O157 H7Fever, diarrhea, abdominal
  cramp-Hemolytic uremic syndrome.
• Newly strain O104 H4, outbreak in German ,May 31
  found 470 cases with HUS---9 deaths. Raw lettuce,
  cucumber and tomatoes.

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Enteroadherent E coli

• Multilayer colonization on intestinal mucose.
• Biofilm formation
• Inhibit water and nutrition absorbtion.
• Malabsorbtion syndrome.