Vibrio, Campylobacter, Helicobacter, and Pseudomonas Flashcards
What do these organisms have in common?
Water/food associated pathogens
Symptoms of Vibrio cholerae
profuse rice water diarrhea, kills you by dehydration (organism is actually non-invasive, staying in GI)
Cholera virulence factor
cholera toxin (CTX), serotypes O1 and O139
toxin coregulated pilus (TCP)- sticks to epithelium and releases it
flagella–> motlie in water
Cholera role in real world
degradation of zooplankton, shells of crabs
lack of water sanitation/ sewage contamination contribute
How is cholera toxin encoded?
By a lysogenic bacteriophage that attaches to the virbio and intergrates in viral DNA so it produces toxin
Pilus = toxin
Pathogenesis of Cholera Toxin
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
Cholera treatment
oral rehydration salt solution/IV fluids
Doxycycline/azithromycin secondary
Vaccine- not v. effective, not avail in US (Dukoral, Shanchol)
Sanitation!
Vibrio parahaemolyticus
salt loving, non-fermenter
associated with contaminated shellfish, sushi, undercooked fish OR open wound in seawater
Vibrio parahaemolyticus virulence factor
hemolycin, adhesin
Vibrio parahaemolyticus illness
self-limited explosive diarrhea with HA, fever, low-grade temp, septicemia in would infections
Vibrio vulnificus
salt loving, fermenter w/ chitinase
Invasive, with enzymes that destroy tissue
Who has highest mortality upon Vibrio vulnificus infection?
Sepsis/bacteremia: persons with iron overload, hepatobiliary disease, blood-based malignancies, ischemic heart disease
Vibrio parahaemolyticus Treatment
supportive care, fluids
tetracycline or quinolone abx?
close contaminated oyster bed
don’t expose wounds to brackish water/salt water
Vibrio vulnificus virulence factors
enzymes destroy crab shell, proteins
Cytolysins, collegenase, proteases
CAPSULE
SIDEROPHORES: iron binding proteins
Vibrio vulnificus Management
tetracyclines, possible aminoglycosides
supportive care
patient education to minimize risk
Aeromonas and Plesiomonas
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
Campylobacter basics
Small, seagull shaped gram neg rods
Like: high temp, low O2, high CO2
Campylobacter reservoirs
poultry
Campylobacter symptoms
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)
Treat: severe GI and systemic infection with campylobacter
erythromycin and tetracyclines and quinolones
Guillain-Barre Syndrome
Autoimmune disorder: cross rxn between surface protein of bacteria and surface antigens of motor neurons
Associated w. Campylobacter
Could lead to ascending symmetric paralysis
Guillain-Barre Syndrome Treatment
plasmapheresis or IV Ig
Helicobacter pylori
gram neg spiral shaped rods, motile
urease producer- helps colonize gut by blocking/neutralizing gastric acid
Urease–> urea
Helicobacter pylori can cause…
atrophic gastritis, gastric ulcers, gastric adenocarcinoma, gastric-associated B-cell lymphoma, duodenal ulcers
