Faculty: Dr' Alvin Fox

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ENTEROBACTERIACEAE, VIBRIO, CAMPYLOBACTER AND
HELICOBACTER
Faculty Dr. Alvin Fox
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Key Words
Opportunistic diseases Shigella
Diarrhea/Dysentery Bacillary
dysentery Urinary tract infections Shiga
toxin Opportunistic infections Salmonella
enteritidis Lactose positive/negative salmonello
sis Enteropathogenic E. coli Salmonella
cholerae-suis Enterotoxigenic E. coli
Salmonella typhi Heat stable toxin
Typhoid Heat labile toxin Vi Enteroinvasive
E. coli Vibrio cholerae Enterohemorrhagic E.
coli Choleragen Vero toxin (Shiga-like)
Yersinia entercolitica Hemolysin
Helicobacter pylori pili Campylobacter
jejuni
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Opportunistic diseases -Enterobacteriaceae

• septicemia,
• pneumonia,
• meningitis
• urinary tract infections

Citrobacter Enterobacter Escherichia Hafnia Morgan
ella Providencia Serratia
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Enterobacteriaceae

• gastrointestinal diseases
• Escherichia coli
• Salmonella
• Shigella
• Yersinia entercolitica

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Reiter's syndrome

• Histocompatibility antigen (HLA) B27
• Enterobacteriaceae
• Salmonella
• Shigella
• Yersinia

• Not Enterobacteriaceae
• Campylobacter
• Chlamydia

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Enterobacteriaceae

• community acquired
• otherwise healthy people
• Klebsiella pneumoniae
• respiratory diseases
• prominent capsule
• urinary tract infection
• fecal contamination
• E. coli
• Proteus
• urease (degrades urea)
• alkaline urine

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Enterobacteriaceae

• Gram negative facultative anaerobic rods
• oxidase negative (no cytochrome oxidase)

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Feces

• E. coli
• lactose positive
• not usually identified
• lactose positive sp. common, healthy intestine
• Shigella
• Salmonella
• Yersinia
• lactose negative
• identified

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Enterobacteriaceae

• other sites
• identified biochemically

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Serotypes

• reference laboratory
• antigens
• O (lipopolysaccharide)
• H (flagellar)
• K (capsular)

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Diarrhea and Dysentery
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Escherichia coli
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Escherichia coli

• E. coli and Shigella
• genetically indistinguishable

• many similarities in diseases

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• Enteropathogenic E. coli

• destruction of surface microvilli

• fever
• diarrhea
• vomiting
• nausea
• non-bloody stools

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Enterotoxigenic E. coli

• diarrhea like cholera
• milder
• travellers diarrhea

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Enterotoxigenic E. coli

• Heat labile toxin
• like choleragen
• Adenyl cyclase activated
• cyclic AMP
• secretion water/ions
• Heat stable toxin
• Guanylate cyclase activated
• cyclic GMP
• uptake water/ions

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Enteroinvasive E. coli (EIEC )

• Dysentery
• resembles shigellosis

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Enterohemorrhagic E. coli

• Usually O157H7

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Meat

• Hemorrhagic
• bloody, copious diarrhea
• few leukocytes
• afebrile
• hemolytic-uremic syndrome
• hemolytic anemia
• thrombocytopenia
• kidney failure

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Enterohemorrhagic E. coli

• Vero toxin
• shiga-like
• Hemolysins

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Treatment -gastrointestinal disease

• fluid replacement
• antibiotics
• not used unless systemic
• e.g. hemolytic-uremia syndrome

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E. coli fimbriae
Type 1
mannose
P

• galactose
• glycolipids
• glycoproteins

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Shigella

• S. flexneri, S. boydii, S. sonnei, S. dysenteriae
• bacillary dysentery
• shigellosis
• bloody feces
• intestinal pain
• pus

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Shigellosis

• within 2-3 days
• epithelial cell damage

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Shigella sonnei
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Shiga toxin

• neurotoxic
• enterotoxic
• cytotoxic
• inhibits protein synthesis
• lysing 28S rRNA

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Shigellosis

• man only "reservoir"
• mostly young children
• fecal to oral contact.
• children to adults
• transmitted by adult food handlers
• unwashed hands

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Treating shigellosis

• manage dehydration
• patients respond to antibiotics
• disease duration diminished

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Salmonella
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Salmonella

• 2000 antigenic "types
• genetically single species
• S. enterica
• disease category
• S. enteritidis
• many serotypes
• S. cholerae-suis
• S. typhi

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Salmonellosis

• S. enteritidis
• the common salmonella infection
• poultry, eggs
• no human reservoir
• Gastroenteritis
• nausea
• vomiting
• non-bloody stool
• self-limiting (2 - 5 days)

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Salmonellosis
uncomplicated cases (the vast majority)
antibiotic therapy not useful
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S. cholerae-suis

• much less common
• septicemia
• antibiotic therapy essential

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Typhoid

• enteric fever.
• severest salmonella disease
• Salmonella typhi
• rare in US
• epidemics
• third world
• Europe
• historical

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Salmonella typhi

• human reservoir
• carrier state common
• contaminated food
• water supply
• poor sanitary conditions

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Typhoid

• Septicemia
• -occurs 10-14 days
• lasts 7 days

• gall bladder
• shedding, weeks

• acute phase, gastroenteritis

gastrointenteritis
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S. typhi

• Vi (capsular) antigen
• protective

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Typhoid -Therapy

• Antibiotics
• essential
• Vaccines
• ineffective

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Yersiniosis

• Yersinia entercolitica
• gastroenteritis
• Scandinavia common
• US
• colder regions

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Yersiniosis

• transmission
• fecal contamination, domestic animals
• water
• milk
• meat

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Yersinia
Diarrhea fever abdominal pain antibiotic therapy
recommended occassional bacteremia
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Yersinia -isolation
cold enrichment
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Y. pseudotuberculosis

• similar
• less severe disease

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Vibrio cholerae
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Vibrios

• Gram negative rods
• comma shaped
• facultative anaerobes
• oxidase positive
• simple nutritional requirements
• readily cultivated

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Occurrence -cholera

• third world
• US
• uncommon
• traveler
• ingestion of sea-food

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Transmission - V. cholerae
feces

• water
• fresh
• salt

• food

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Cholera - attachment
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Cholera toxin- Choleragen

• B binds to gangliosides
• provides channel for A
• A catalyses ADP-ribosylation
• regulator complex
• activates adenylate cyclase

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Cholera -therapy

• massive secretion of ions/water into
• gut lumen

• dehydration and death

• therapy
• fluid replacement
• antibiotic therapy

• vaccination
• partially effective
• not generally used
• international travelers

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Vibrio parahemolyticus

• raw sea-food
• grows best in high salt
• not common in US
• diarrhea

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CAMPYLOBACTER HELICOBACTER

• Gram negative rods
• curved or spiral
• genetically related.

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Campylobacter
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C. jejuni.

• infects the intestinal tract of animals
• cattle and sheep
• major cause of abortions.

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Transmission

• milk
• meat products

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Campylobacter
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Isolation - Campylobacter

• microaerophilic
• grows best 42oC.

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Campylobacter - symptoms

• diarrhea
• malaise
• fever
• abdominal pain
• usually self-limiting
• antibiotics occassionally
• bacteremia
• small minority

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Helicobacter pylori

• stomach mucosa
• ulcers

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Urease

• Important in neutralizing stomach acid

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Diagnosis -Helicobacter

• 1. Culture
• 2. urease NH4 CO2
• mucosal endoscopy NH4
• radioactive CO2 in breath
• after feeding radioactive urea

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Therapy -Helicobacter

• Antibiotics
• cures ulcers

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Summary statement

• sanitary measures
• protect the water supply
• food/water borne epidemics
• rare US
• common third world.
• zoonotic infections
• contaminated animal products
• less well controlled
• common US and elsewhere

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Therapy

• severe diarrhea
• fluid replacement essential
• antibiotic therapy sometimes used in local
• infection but always in systemic disease