13 Family Enterobacteriaceae

Enterobacteriacaea common characteristics

1. Gram (-) short rods

2. Non-sporeforming, may or may not be capsulated or with slime layer

3. Motile with peritrichous flagella except Shigella and Klebsiella

Enterobacteriacaea common characteristics

1. Gram (_) short rods

2. Non-________, may or may not be _______ or with slime layer

3. Motile with ________ flagella except _____ and ______

shigella and klebsiella

Motile with peritrichous flagella except?

Enterobacteriaceae common characteristics

4. Possess fimbriae or pili

5. All are aerobic but can be facultatively anaerobic

6. Simple nutritional requirement

Enterobacteriaceae common characteristics

4. Possess _____ or ___

5. All are _____ but can be ______ anaerobic

6. _____ nutritional requirement

FALSE, all are aerobic but can be facultatively anaerobic

Enterobacteriaceae cannot be facultatively anaerobic

Enterobacteriaceae common characteristics

7. All ferment glucose with acid production

8. Reduce nitrate (NO3) to nitrite (NO2)

9. Oxidase negative, catalase positive

Enterobacteriaceae common characteristics

7. All ferment _____ with ___ production

8. Reduce _____ (NO3) to ____ (NO2)

9. Oxidase _____, catalase _____

• K (capsular) antigen

• H (flagellar) antigen

• O (somatic) antigen

• Vi 

Enterobacteriaceae antigenic structure

K (capsular) antigen

capsular polysaccharide particularly heavy in Klebsiella

H (flagellar) antigen

flagellar proteins of motile genera and species

O (somatic) antigen

O-specific polysaccharide chain of lipopolysaccharide

Vi

capsule of Salmonella

Over 30 genera and 130 species

Enterobacteriaceae has how many genera and species?

Lactose Fermenters

• Citrobacter

• Escherichia

• Enterobacter

• Klebsiella

Non-lactose fermenters

• Shigella

• Yersinia

• Proteus

• Salmonella

CEEK SYPS

Cite both lactose and non lactose fermenters in Enterobacteriaceae

• Morganella morganii

• Providencia spp.

• Serratia spp.

• Erwinia

MPSE

Cite others in Enterobacteriaceae

• Citrobacter

• Enterobacter

• Serratia

• Morganella morganii (formerly Proteus morganii/Providencia)

• Edwardsiella

CESME

Cite opportunistic Enterobacteriaceae

Escherichia coli are commonly found in the lower intestines of warm-blood animals (endotherms)

Escherichia coli are commonly found in the ___ intestines of ____-blood animals (endotherms)

E. coli

Endotherms

fish and cold-blooded animals

Escherichia coli are absent from intestines of?

carnivores and omnivores

E. coli harbor which organism?

E. coli have few or no organism in stomach and anterior bowel

E. coli have few or no organism in _____ and _______ bowel

In E. coli, most strains are harmless but some serotypes pathogenic and cause food poisoning in humans and majority of cases of UTI

In E. coli, most strains are _____ but some serotypes pathogenic and cause ____ ________ in humans and majority of cases of ___

E. coli of Harmless strains part of normal flora of the gut > produces Vit K and prevent establishment of pathogenic bacteria within the intestine

E. coli of harmless strains part of normal flora of the gut > produces Vit _ and prevent establishment of pathogenic bacteria within the ____

feco-oral route

major route in E. coli?

E. coli is most widely studied prokaryote model organism

E. coli is most widely studied ______ model organism

Theodore Escherich

E. coli is discovered by this German pediatrician and bacteriologist in 1885?

O157:H7

This strain of E. coli produce lethal toxins

E. coli food poisoning can result from eating unwashed vegetables and uncooked meat

E. coli food poisoning can result from eating ____ vegetables and _____ meat

O,K,H,F (adhesive function)

Antigen in E.coli

K88 (F4)

Best known antigen in E. coli?

1. Plasmid encoded heat labile LT enterotoxin

2. Heat stable ST enterotoxin

3. Edema disease toxins – first of the E coli toxins to be demonstrated

4. Shiga-like toxin (SLT)

Enterotoxins of E. coli

LT enterotoxin

consists of 2 dissimilar polypeptide subunits A and B -> 5B and 1A subunit in each entire toxin molecule

1. B subunits bind to gangliosides GM1 on mucoid cells on the intestines

2. subunit A activates adenylate cyclase by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP increase which causes a net outflow of Na, Cl and water from cell

1. _ subunits bind to gangliosides GM1 on mucoid cells on the ______

2. subunit A activates adenylate cyclase by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP increase which causes a net outflow of Na, Cl and water from cell

1. B subunits bind to gangliosides GM1 on mucoid cells on the intestines

2. subunit A activates adenylate cyclase by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP increase which causes a net outflow of Na, Cl and water from cell

1. B subunits bind to gangliosides GM1 on mucoid cells on the intestines

2. subunit _ activates _____ _______ by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP increase which causes a net outflow of Na, Cl and water from cell

1. B subunits bind to gangliosides GM1 on mucoid cells on the intestines

2. subunit A activates adenylate cyclase by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP increase which causes a net outflow of Na, Cl and water from cell

1. B subunits bind to gangliosides GM1 on mucoid cells on the intestines

2. subunit A activates adenylate cyclase by NAD-dependent ADP ribosylation of its regulatory subunits

3. levels of intracellular cyclic AMP ______ which causes a net outflow of ___ , ____ and ____ from cell

Sta and STb

ST exists as?

STa found in enterotoxigenic E. coli from baby piglets

• Soluble in methanol and has biological activity in suckling mice

• Activates guanylate cyclase in intestinal mucosal cells -> inhibition of Na and Cl absorption by brush border

STb – found in enterotoxigenic E. coli from weanling pigs

• Insoluble and no biological activity in suckling mice

• No effect in cyclic GMP levels in intestinal mucosal cells

• Mechanism of fluid efflux unknown -> characterized by an early onset of action that is evident for as long as 18 hours in pig intestine

STb – found in enterotoxigenic E. coli from weanling pigs

which has no effect in cyclic GMP levels in intestinal mucosal cells?

Edema disease toxins

first of the E coli toxins to be demonstrated

Edema disease toxins are Thermolabile protein, insoluble at acid pH but soluble at alkaline pH

Edema disease toxins are ______ protein, insoluble at ____ pH but soluble at _____ pH

Edema disease toxins Related to Shiga-like toxin 2 (SLT2) of E. coli found in hemorrhagic colitis in humans

Edema disease toxins Related to _______ toxin 2 (SLT2) of E. coli found in hemorrhagic colitis in humans

Edema disease toxins Produces paralysis and death in mice and toxic changes in Vero cells

Edema disease toxins Produces _____ and _____ in mice and toxic changes in ____ cells

Edema disease toxins

• May inhibit protein synthesis in endothelial cells of blood vessels

• End effect is hypertension and panarteritis

Edema disease toxins

• May inhibit ______ synthesis in endothelial cells of blood vessels

• End effect is _____ and ______

Shiga like toxin

Proteinaceous protein produced by most enteropathogenic E, coli from enteritis in human infants

Shiga like toxin Structurally resembles cytotoxin of Shigella dysenteriae type 1 (Shiga)

Shiga like toxin Structurally resembles cytotoxin of ______ _______ type 1 (Shiga)

Shiga like toxin contains A and B subunits, B with toxin-binding function

Shiga like toxin contains _ and _ subunits, B with ___ -binding function

Shiga like toxin is cell associated with E.coli which inhibit protein synthesis, produced in iron deprivation, lethal for mice, enterotoxic for rabbits

Shiga like toxin is cell associated with E.coli which inhibit protein synthesis, produced in ____ deprivation, lethal for ___, enterotoxic for ____

Shiga like toxin is Associated with destruction of gut epithelial cell microvilli (effacement) -> effacing E. coli

Shiga like toxin is Associated with ______ of ___ epithelial cell _____ (effacement) -> effacing E. coli

Pathogenesis

E.coli is Associated with disease of the intestine and fulminating septicemia of young and newborn, respiratory disease of poultr

Pathogenesis

E.coli is Associated with disease of the _____ and fulminating _____ of young and newborn, respiratory disease of _____

Pathogenesis

E.coli is an Opportunistic infection in udder, uterus and body parts

Pathogenesis

E.coli is an Opportunistic infection in ____, _____ and ___ parts

1. ETEC – enterotoxigenic E. coli

2. EPEC – enteropathogenic E. coli

3. EIEC – enteroinvasive E. coli

4. AEEC – attaching and effacing E. coli

5. EHEC – enterohemorrhagic E. coli

6. EAEC – enteroaggregative E. coli

7. AIEC – adherent-invasive E. coli

E. coli strains that cause enteritis

ETEC – enterotoxigenic E. coli

E. coli strain that produce enterotoxins

ETEC – enterotoxigenic E. coli

Uses fimbrial adhesins to bind to enterocytes in the small intestines

a. LT – similar to cholera toxins

b. ST – cGMP accumulation in the target cells and subsequent secretion of fluids and electrolytes into intestinal lumen

ETEC Produces 2 proteinaceous enterotoxins:

ETEC – enterotoxigenic E. coli

Non-invasive, do not leave intestinal lumen

LT in ETEC

similar to cholera toxins

ST in ETEC

cGMP accumulation in the target cells and subsequent secretion of fluids and electrolytes into intestinal lumen

EPEC – enteropathogenic E. coli

Do not produce enterotoxins or Shiga-like toxins and cause enteritis by other unknown mechanism

EPEC – enteropathogenic E. coli

Use adhesins known as intimin to bind host intestinal cells

intimin

Adhesins used by EPEC

EPEC – enteropathogenic E. coli

Virulence factor similar to Shigella

EPEC – enteropathogenic E. coli

Adherence to intestinal mucosa causes rearrangement of actin in host cell causing deformation

EPEC – enteropathogenic E. coli

Moderately invasive and elicits an immune response

EPEC – enteropathogenic E. coli

Changes in intestinal cell ultrastructure due to attachment and effacement is likely to cause diarrhea

EIEC – enteroinvasive E. coli

strain that is only in humans

EIEC – enteroinvasive E. coli

Invade enterocytes and deeper layers of mucosa of intestine

EIEC – enteroinvasive E. col

Syndrome similar to shigellosis with profuse diarrhea and high fever

AEEC – attaching and effacing E. coli

Colonize the intestine

AEEC – attaching and effacing E. coli

Produce Shiga-like toxins and destroy microvilli layers

EHEC – enterohemorrhagic E. coli

Most infamous member of pathotype is O157:H7

EHEC – enterohemorrhagic E. coli

Causes bloody diarrhea without fever

EHEC – enterohemorrhagic E. coli

Causes hemolytic-uremic syndrome and sudden kidney failure

EHEC – enterohemorrhagic E. coli

Uses bacterial fimbria for attachment, moderately invasive

EHEC – enterohemorrhagic E. coli

Possesses Shiga toxin that elicit intense inflammatory response

EAEC – enteroaggregative E. coli

Fimbriae aggregate tissue cells

EAEC – enteroaggregative E. coli

Binds to intestinal mucosa to cause watery diarrhea without fever

EAEC – enteroaggregative E. coliaa

Non-invasive, produces hemolysins and ST enterotoxins similar to ETEC

EAEC – enteroaggregative E. coli

Found only in humans as well

AIEC – adherent-invasive E. coli

Invade intestinal epithelial cells and replicate intracellularly

AIEC – adherent-invasive E. coli

Able to proliferate more effectively in host

AIEC – adherent-invasive E. coli

Diseases characteristically found in newborn and young animals

AIEC – adherent-invasive E. coli

Critical factor immune status of newborn

AIEC – adherent-invasive E. coli

Colostrum and predisposing factors

AIEC – adherent-invasive E. coli

Primary source of infection is feces

Manifestations of enteric colibacillosis in swine

1. Neonatal E. coli enteritis – piglets 1 to 4 days

2. Weanling enteritis – shortly after weaning

3. Edema disease – in various body tissues after weaning

Manifestations of enteric colibacillosis in swine

Adhesion -> colonization -> toxin production

Pathogenesis of neonatal enteritis

Neonatal enteritis

affects piglets 1-4 days

Neonatal enteritis

Profuse, pale yellow, watery diarrhea -> fatal dehydration within 18 hours -> mortality as high as 90%

Weanling enteritis

Hemolytic E. coli

Weanling enteritis

occurs shortly after weaning

Weanling enteritis

Change of diet leads to massive colonization of anterior small intestine

Weanling enteritis

Persists for 2 to 3 days, pigs collapse and die after short period of diarrhea

Weanling enteritis

Net efflux of sodium, water, bicarbonate and chloride into bowel lumen

Edema disease

Bowel edema

•Colonization -> release of edema disease (ED) toxin -> bloodstream -> small arteries -> mural edema, hyaline degeneration, permeable to fluid

edema disease pathogenesis

Edeme disease

ED toxin vasotoxin -> hypertensiv

1. enteric disease

2. Mastitis

disease in cattle

enteric disease in cattle

white scours, during first week of life

enteric disease in cattle

• Severe diarrhea with feces full of gas bubbles 16 Contoso Suites -

• Die in a few days due to dehydration and acidosis

mastitis

E. coli most important causative agent in this disease in cattle

collibacillosis

• enteric diarrhea

• bacteremic - sudden death

disease in lambs