Mhr Topic 18: Gram Negative Enteric Rods

Front 1

3 main conditions associated with enteric rods?

Back 1

Sepsis, GI and UTI

Front 2

3 diseases that can be caused when enteric rods get into the blood

Back 2

Meningitis, pneumonia, and salmonella can get into the bone.

Front 3

Enterotoxins secreted in the SI v.s. Colon

Back 3

SI - Nausea, vomiting, watery diarrhea
Colon - Bloody diarrhea, fever, cramps, abdominal pain, leukocytes in the stool.

Front 4

3 organisms responsible for neonatal meningitis

Back 4

1) Group B strep
2) E. coli
3) Lysteria

Front 5

Enterotoxigenic E. coli (Normal habitat, infection route, disease)

Back 5

1) Normally found in colon of humans and animals.
2) Infection via fecal contaminated food and water. Known as travelers diarrhea b/c locals have built up an IgA immunity but travelers have not.
3) Get watery diarrhea for several days without blood or mucus, nausea, vomiting.

Front 6

Enterotoxigenic E. coli (Virulence factors and disease mech.)

Back 6

1) Pilli - allow bacteria to bind to SI.
2) LT and ST Enterotoxins - After bacteria has bound to SI, toxin is released.
Toxin binds, ^ cGMP/AMP,causes release of chlorine and water, watery diarrhea.

Front 7

Enteropathogenic E. coli (Normal habitat, infection route, disease)

Back 7

1) Colon of humans
2) Fecal contaminated food or water.
3) Watery diarrhea for several days, fever, vomiting.

Front 8

Enteropathogenic E. coli (Virulence factors and disease mech.)

Back 8

1) Bundle forming Pilli (BFP) - adhere to the small intestine. Trigger a signal cascade causeing NaCl secretion and fluid loss. Also damages mircovilli.

Front 9

Enterohemorrhagic E. coli (Normal habitat, infection route, disease)

Back 9

1) Colon of animals
2) Contaminated, undercooked beef or milk, animal contact (petting zoos), other food contaminated with cow feces. Less than 100 organisms needed.
3) Mild to copious bloody diarrhea, sever abdominal pain, no fever. Hemorrhagic colitis can lead to hemolytic uremic syndrome (HUS) leading to acute renal failure.

Front 10

Enterohemorrhagic E. coli (Virulence factors and disease mech.)

Back 10

1) Binds to brushborder of large intestine
2) Verotoxin (shigellatoxin) - After bound, bacteria secretes toxin leading to
-destruction of microvilli
-toxin enters cell and inhibits protein synth causing cell death
-gets into blood causes endothelial damage and platlet aggregation
-platlet thrombi causes hemorrhagic colitis and hemolytic uremic syndrome

Front 11

What test can distinguish Enterohemorhagic ecoli from other e.colis?

Back 11

Enterohamorrhagic E. coli is sorbitol negative (dosent ferment), others are positive.

Front 12

Enteroinvasive E. coli (normal habitat, infection, disease)

Back 12

1) Colon of humans
2) Fecal contaminated food or water
3) Fever, scant-bloody diarrhea, pus in diarrhea.

Front 13

Enteroinvasive E. coli (virulence factors and disease mech)

Back 13

1) Organism binds large intestine
2) Invades mucosal cells causing inflammation, inflammation leads to leukocytes in stool.

Front 14

Uropathogenic E. coli (normal habitat, infection, disease)

Back 14

1) Normal flora of human colon
2) Organisms get out of normal site via sex, pregnancy, obstruction, prostate hyperplasia, and nosocomial infections via urinary catheters.
3) Cystitis aka bladder infection aka uncomplicated UTI - Dysuria, frequent urination
Pyelonephritis aka kidney infection aka complicated UTI - dysuria, fever, shaking chills, flank pain, nausea, vomiting.

Front 15

Uropathogenic E. coli (virulence factors and disease mech)

Back 15

1) Pilli - pilli bind to receptors on urinary tract epithelium
2) K1 capsule - Stimulate cytokines/inflamation, also resists compliment
3) Motility - allows bacteria to ascend to bladder and kidney
4) LPS effects

Front 16

Extraintestinal E. coli (normal habitat, infection, disease)

Back 16

1) ?
2) Get via passing through birth canal or nosocomial via urinary catheters
3) Neonatal meningitis from birth, sepsis, endotoxic shock, pneumonia in nosocomial infections in immunocomprimised.

Front 17

Extraintestinal E. coli (virulence factors and disease mech)

Back 17

1) LPS effetcs
2) K1 capsule - inhibits phagocytosis and compliment

Front 18

Uropathogenic E. coli (diagnosis)

Back 18

Significant bacteruria (>10^5 CFU of midstream urine)
Pyuria (inflammatory cells in urine)
White cell casts (cylinder aggregations of protein in distal convoluted tubule

Front 19

Lab results for E. coli (Gram, MacConkey, oxidase, motility, sterotyping for antigens)

Back 19

1) Gram negative
2) Lactose +
3)Oxidase -
4) Motile
5) O, H, and K (LPS, flagellum, and capsule respectively)

Front 20

Shigella (reservoir, infection, disease)

Back 20

1) Human reservoir only
2) fecal oral transmission. Less than 100 organisms needed.
3) Enterocolitis, initial watery diarrhea, then cramps, fever, scant bloody dysentery, mucus/pus/leukocytes in stool

Front 21

Shigella (virulence factors and disease mech)

Back 21

1) pilli - Bind to and allow entrance into M cells in colon.
2) Invasins - enduce endocytosis and Actin polymerization.
3) polymerize actin within cells. Uses actin to inject itself into neighboring cell. Cause cell death and inflammation.
4) Acid resistant to stomach Ph

Front 22

Shigella dysenteriae (disease and mech)

Back 22

Most pathogenic Shigella which causes hemolytic uremic syndrome (HUS) and renal failure.
Produces Shiga toxin which binds to renal vasculature and kills by inhibiting protein synth.

Front 23

Shigella Diagnosis (Gram stain, oxidase, lactose, H2S, motility, stool)

Back 23

1) Gram - rod
2) Oxidase -
3) Lactose -
4) H2S - (different from salmonella)
5) non motile (")
6) Leukocytes in stool

Front 24

Salmonella (reservoir, infection, disease)

Back 24

1) Poultry, eggs, dairy
2) Fecal oral transmission via contaminated food/water consumption, need many organisms
3) Watery diarrhea, nausea, vomiting, progresses to bloody diarrhea (more volume b/c involvement of both intestines) possible fever. Can get bone infection in peeps with sickle cell.

Front 25

Salmonella (virulence factors and disease mech)

Back 25

1) pilli - allow binding to both small and large intestine
2) Gets endocytosed, avoids being killed.
3) Releases invaisins - cause chloride and water excretion
4) In colon, cause cell death, inflamation
5) can get into blood stream and lead to LPS effects

(AKA intracellular, causing watery diarrhea, can get into blood stream and cause LPS)

Front 26

Salmonella Diagnosis (Gram, oxidase, lactose, H2S, motility, stool)

Back 26

1) gram - rod
2) oxidase -
3) lactose -
4) H2S + (different from shigella)
5) Motile (")
6) leukocytes in stool

Front 27

Salmonella typhi (reservoir, infection, disease)

Back 27

1) Only human
2) fecal/oral transmission via contaminated food/water in endemic areas (latin america, asia, and india)
3) Severe life threatening systemic illness. High fever, constipation, chills, headache, delerium, tender abdomen, enlarged liver and spleen, rose spots

Front 28

Salmonella typhi (virulence factors and disease mech)

Back 28

1) Is resistant to bile, hides in biliary tract
2) Pili for attachment to SI
3) Inject invasins into host
4) Neutralize killing inside cells, easily get into bloodstream, lead to LPS effect and septic shock

Front 29

Campylobacter (reservoir, infection, disease)

Back 29

1) poultry, cattle, dogs
2) fecal oral food/water contamination, improper handling of food (especially poultry). Need less than 500 organisms
3) 1-7 days post exposure get watery to bloody diarrhea with fever and severe abdominal pain.
C. jejuni associated with Guillain Barre syndrome - autoimmune demylenating neuropathy
C. intestinalis associated with systemic infection of young/old and immunocompromised.

Front 30

Campylobacter (virulence factors and disease mech)

Back 30

1) Colonizes intestinal mucosa via flagella and adhesins (colon and SI minus duodenu,)
2) Cytotoxin, endotoxin, and enterotoxin similar to cholera cause inflamation, acute gastroenteritis, ulceration.

Front 31

Campylobacter diagnosis (Gram, motility, oxidase, O2 and temp restrictions)

Back 31

-First isolate on CAMPY media which inhibits other fecal flora
-gram - curved rods (seagulls)
-darting motility
-oxidase +
-like 5% O2, 10% CO2
-likes 42 C

Front 32

Yersinia (Reservoir, infection, disease)

Back 32

1) animals
2) Via food and milk contaminated with animal feces (dog cat cattle)
3) Enterocolitis similar to salmonella and shigella. Also associated with reactive arthritis and Reiters syndrome (autoimmune)

Front 33

Yersinia (virulence factors and disease mech)

Back 33

1) Adhesins
2) Invasins
3) YOPs inhibit phagocytosis

Front 34

Yersinia diagnosis (gram, lactose, temp)

Back 34

Isolate on selective media
-gram -
-lactose -
- grows at 25 C

Front 35

Vibrio (Reservoir, infection, disease)

Back 35

1) Human GI tract
2) Consume undercooked seafood contaminated with human feces. Need huge number of organisms. Endemic to U.S. gulf
3) Rice water stools (watery and cloudy) immense amount of water loss (10 liters a day). Also causes swimmers ear.

Front 36

Vibrio (virulence factors and disease mech)

Back 36

1) NaCl stimulates growth
2) Not acid resistant
3) Cholera toxin is a classic AB toxin, adheres to small bowel, is taken in, causes ADP-robosylation, hypersecretion of NaCl and water

Front 37

Vibrio diagnosis (gram, oxidase, motility)

Back 37

Isolate on selective media
-gram negative curved rod (comma shaped)
-oxidase +
-very motile

Front 38

Helicobacteria (infection, disease)

Back 38

1) Can be transmitted human to human
2) Stomach bleeding and pain, chronic inflammation, possible cancer.

Front 39

Helicobacter (virulence and disease mech.)

Back 39

1) Mucinase - penetrate stomach mucosal layer
2) Flagella - motility
3) Urease - Converts urea to ammonia in stomach damaging cells and neutralizing pH
4) cytotoxin
5) endotoxin

Front 40

Klebsiella pneumoniae (reservoir, infection, disease)

Back 40

1) ubiquitous in nature and body
2) Oportunistic infection. Often nosocomial.
3) Respiratory problems, UTI, wound infection, can lead to sepsis. Cough up jelly looking sputum.

Front 41

Klebsiella pneumoniae (virulence and disease mech.)

Back 41

1) Luxurious complex capsule inhibits phagocytosis and compliment)
2) Have pilli and adhessions
3) Endotoxin

Front 42

Klebsiella pneumoniae diagnosis (gram, lactose, urease, motility)

Back 42

Short, plump gram - rod
lactose +
urease +
non-motile

Front 43

Helicobacter Diagnosis (gram, oxidase, urease, O2)

Back 43

gram - curved, helical s shaped rod
oxidase +
Urease +
Microaerophilic

Front 44

Enterobacteriacaea

Back 44

Oportunistic, nosocomial, antibiotic resistant, urease +.

Front 45

Food poisoning: who is responsible for 1-6 hour onset, 8-16 hours onset, and more than 16 hour onset.

Back 45

1-6:
-Bacillus cereus
-Staphylococcus aureus
8-16:
-Clostridium perfringens
-Bacillus cerus (if caused by bug, not preformed toxin)
>16:
-Campylobacter jejuni
-Clostridium botulinum
-Escherichia coli
-Salmonella
-Shigella