Vibrio, Campylobacter, Helicobacter, and Pseudomonas

Question 1

What do these organisms have in common?

Answer 1

Water/food associated pathogens

Question 2

Symptoms of Vibrio cholerae

Answer 2

profuse rice water diarrhea, kills you by dehydration (organism is actually non-invasive, staying in GI)

Question 3

Cholera virulence factor

Answer 3

cholera toxin (CTX), serotypes O1 and O139
toxin coregulated pilus (TCP)- sticks to epithelium and releases it
flagella–> motlie in water

Question 4

Cholera role in real world

Answer 4

degradation of zooplankton, shells of crabs

lack of water sanitation/ sewage contamination contribute

Question 5

How is cholera toxin encoded?

Answer 5

By a lysogenic bacteriophage that attaches to the virbio and intergrates in viral DNA so it produces toxin
Pilus = toxin

Question 6

Pathogenesis of Cholera Toxin

Answer 6

Pentamer of 5 B subunits and an A subunit.
B binds to intestinal epithelium.
A activates adenylate cyclase in enterocytes–> causes inappropriate flux of water and electrolytes OUT of cells into lumen

Question 7

Cholera treatment

Answer 7

oral rehydration salt solution/IV fluids
Doxycycline/azithromycin secondary
Vaccine- not v. effective, not avail in US (Dukoral, Shanchol)
Sanitation!

Question 8

Vibrio parahaemolyticus

Answer 8

salt loving, non-fermenter

associated with contaminated shellfish, sushi, undercooked fish OR open wound in seawater

Question 9

Vibrio parahaemolyticus virulence factor

Answer 9

hemolycin, adhesin

Question 10

Vibrio parahaemolyticus illness

Answer 10

self-limited explosive diarrhea with HA, fever, low-grade temp, septicemia in would infections

Question 11

Vibrio vulnificus

Answer 11

salt loving, fermenter w/ chitinase

Invasive, with enzymes that destroy tissue

Question 12

Who has highest mortality upon Vibrio vulnificus infection?

Answer 12

Sepsis/bacteremia: persons with iron overload, hepatobiliary disease, blood-based malignancies, ischemic heart disease

Question 13

Vibrio parahaemolyticus Treatment

Answer 13

supportive care, fluids
tetracycline or quinolone abx?
close contaminated oyster bed
don’t expose wounds to brackish water/salt water

Question 14

Vibrio vulnificus virulence factors

Answer 14

enzymes destroy crab shell, proteins
Cytolysins, collegenase, proteases
CAPSULE
SIDEROPHORES: iron binding proteins

Question 15

Vibrio vulnificus Management

Answer 15

tetracyclines, possible aminoglycosides
supportive care
patient education to minimize risk

Question 16

Aeromonas and Plesiomonas

Answer 16

water associated gram neg rods
GI, sepsis, wound infection
Seen in: bite wounds from reptile/snakes OR abrasion in water
Beta lactam resistant, especially aeromonas

Question 17

Campylobacter basics

Answer 17

Small, seagull shaped gram neg rods

Like: high temp, low O2, high CO2

Question 18

Campylobacter reservoirs

Answer 18

poultry

Question 19

Campylobacter symptoms

Answer 19

self limiting diarrhea, fatigue, fever, abdominal pain, multi-stool per day, sometimes bloody, week or more, bacteremia, sepsis, colitis, micro-abscess in intestine (C. jejuni)

Question 20

Treat: severe GI and systemic infection with campylobacter

Answer 20

erythromycin and tetracyclines and quinolones

Question 21

Guillain-Barre Syndrome

Answer 21

Autoimmune disorder: cross rxn between surface protein of bacteria and surface antigens of motor neurons
Associated w. Campylobacter
Could lead to ascending symmetric paralysis

Question 22

Guillain-Barre Syndrome Treatment

Answer 22

plasmapheresis or IV Ig

Question 23

Helicobacter pylori

Answer 23

gram neg spiral shaped rods, motile
urease producer- helps colonize gut by blocking/neutralizing gastric acid
Urease–> urea

Question 24

Helicobacter pylori can cause…

Answer 24

atrophic gastritis, gastric ulcers, gastric adenocarcinoma, gastric-associated B-cell lymphoma, duodenal ulcers

Question 25

Helicobacter pylori reservoir and spread

Answer 25

Reservoir: humans primarily
Spread: fecal-oral, vomit, AEROSOLIZATION!
asymptomatic

Question 26

Helicobacter pylori Diagnosis

Answer 26

endoscopy, urease test, urea breath test, serology

Question 27

Helicobacter pylori Treatment

Answer 27

two abx PLUS anti-acid medication

ex. 14 days PO BID omeprazole, amoxicillin, clarithromycin

Question 28

Pseudomonas Aeruginosa

Answer 28

found in decaying vegetation
non-fermenting large gram neg rods
like to metabolize anything

Question 29

Pseudomonas Aeruginosa virulence

Answer 29

polysaccharide capsule
pili
adhesions
siderophores
*Exotoxin A (blocks protein synthesis)
elastases
proteases
*biofilm
Abx resistance: porins and beta-lactamase efflux pumps

Question 30

Two bacteria similar to Pseudomonas Aeruginosa

Answer 30

Burkholderia cepacia
Stentotrophomonas (Xanthomonas) maltophilia
Both nosocomial pathogens associated with water

Question 31

Pseudomonas Aeruginosa Clinical Syndromes

Answer 31

• Pneumonia, especially CF, ventilator patients
• Bacteremia/rapid sepsis: immunocompromised hosts
• hot tub folliculitis, ecthyma gangrenosum
• Nail infection green nails- grape smell
• UTI
• Swimmers Ear, Malignant Otitis Externa in diabetics
• Contact lens assoc. infection
• diabetic foot infection
• endocarditis with IVDA, sepsis
• Nuerosurgical hardware

Question 32

Pseudomonas Aeruginosa Treatment

Answer 32

ticarcillin, piperacillin, ceftazidime, aminoglycosides

Possible: G-CSF or debridement of tissue, remove hardware