3/1: Cholera and ETEC Flashcards
Vibrio cholera prefers ___
___ pH
___ ID
Infects ___
saltwater
8.5-9.0 pH
High ID
infects small intestine
How do you get vibrio cholera?
obtained from seafood that is undercooked and spread by contaminated water
Only strains of vibrio cholera that have _____ can produce the cholera toxin
O1 or O139
2 biotypes of vibrio cholera cause cholera: __ and __
classic type
El tor
In the environment, vibrio cholera produces ___
biofilms
What are the 3 virulence factors of vibrio cholera?
flagella
pili
cholera toxin
Define cholera toxin
encoded by phage
A-B toxin that leads to excessive accumulation of cAMP that causes hypersecretion of Cl, K, Bicarobate
___ alone is what causes diarrhea in vibrio cholera
cholera toxin
What are the symptoms of cholera
loss of liters of fluid
rice water stool containing excess K and bicarbonate
leading to hypokalemia and metabolic acidosis
death within hours from fluid loss
What is the immune response to cholera
nonspecific defenses
secretory IgA against O antigen, B subunit of toxin or pilus
What is the treatment for vibrio cholera
oral solution of glucose, Na, Cl, Excessive levels of K and bicarbonate EARLY
antibiotics can reduce severity
___ causes “travelers diarrhea”
ETEC
Travelers diarrhea is caused by ingesting E.Coli through ____
___ ID
containminated food/water
HIGH ID
ETEC colonizes in ____
proximal small intestine
What are the 3 virulence factors of ETEC
colonizing factor (CF) pilli
heat-labile toxin (LT)
heat-stable toxin (ST)
In ETEC, heat labile toxin (LT). define.
A-B toxin leads to secretion of Cl, blocks NaCl reabsorption
In ETEC, heat stabile toxin (ST). define.
initiates signaling cascade that ends with electrolyte /fluid secretion
What is the immune response to ETEC
LT and CF secretory IgA
How do you diagnose ETEC?
rule out cholera infection
TCBS agam, agglutination test, serological test
What is the treatment for ETEC
oral rehydration (sugar and salt) antibiotics can reduce severity/duration
___ is the most common form of bacterial infection in an organ
uti
cystitis is ___
infection of bladder
W/M: more affected by UTI. why?
women
shorter urethra
Describe difference between uncomplicated and complciated UTI
uncomplicated - normal defense mechanisms in tact, infection contained to urethra/lbladder. UPEC or other COMMENSAL E.COLI
complicated - some anatomical abnormalities, spreads to kidneys,c aused by enterobactericeae
What are the 5 natural defenses of the urinary tract
complete voidance of bladder peristalsis of ureters --> bladder ureterovesicle valves (no backflow) mucous layer acidic pH
What is pyelonephritis
kidney infection
cystitis can spread from bladder up ureters in RETROGRADE FLOW
Who is susceptible to pyelonephritis (5)
- spinal cord injury patients
- kids (undeveloped uterovesicle valves)
- pregnant women (dilated ureters, perstalsis decreased)
- catheter patients
- patients with urinary tract sotnes
____ causes 90% of utis
e.coli
opportunistic infection usually originated in the intestine
UPEC causes ___-
uncomplicated UTIs
What are the 4 virulence factors of UPEC?
- type 1 pili - binds to d-mannose
- p pili - binds to digalactoside in urinary tract
- alpha-hemolysin toxin
- CNF toxin
Proteaus mirabilis causes ____
complicated UTIs
more severe than UTIs caused by e.coli
What are the 4 virulence factors of proteus mirabilis
flagella (adhesion)
hemolysin
IgA protease
urease
How do you diagnose proteus mirabilis UTI
if asymptomatic and no pain - need bacteria levels 10^5
if symptomatic with pain, need bacteria levels 10^2
treatment of proteus mirabilis UTI
antimicrobials
T/F Klebsiella bacteria is motile
NO
no H antigen
Klebsiella can infect ____
urinary tract or respiratory tract
What are the 4 virulence factors of Klebsiella?
pili (type 1 = urinary tract, type 3= respiratory)
antiphagocytic capsule
enterotoxin
aerobactin = sequesters iron
What is the treatment for Klebsiella?
RESISTANT TO ANTIBIOTICS
Helicobacter pylori is motile/immotile
motile
H. pylori causes ___
ulcers, chronic superficial gastridis, even cancer
Define ulcer
erion of epithelium
what is h.pylori’s mode of transmission
uknown
likely fecal-oral or oral-oral
___ bacteria is considered a class I carcinogen
h. pylori
h. pylori can colonize in the stomach due to it’s efficient and rapid production of ____
urease
why does urease help h.pylo colonize in the stomach
urease converts urea –> amonia, rising the pH making the stomach live-able
Once h.pylori is ingested, it senses the low pH or the stomach is secretes urease trying to get to the ____
mucous layer of the stomach
Once h.pylori is at the mucous layer of the stomach, it uses ___ to propel itself deeper into the layer to continue secreting urease
flagella
Once h.pylori has adhered to the epithelium, it injects ___ into the epithelium using ___ secretion
h.pylori does not enter epithelium
h.pylori injects VacA and Cag into the epithelial host
via type 4 secretion system
h.pylori injects VacA into epithelial host cells. what does this do?
creates vacuoles inside epithelial cells and kills them.
invokes inflammatory response that contirbutes to death and ulcer formation
Ulcer formation is produced via:
____ from epithelial cells
____ from bacteria
IL-8 from epithelial cells
Cytotoxin from bacteria
What are symptoms of h.pylori infection
can be silent or lead to nausea, upper abdominal pain
can be present as non-specific symptoms like belching, heartburn, difficulty swallowing, sensation of something stuck in the back of your throat
How do we diagnose h.pylori?
biopsy - because there usually isn’t anything in stomach
urea breath tests
What is an urea breath test
tests of h.pylori infection
patient breaths in labeled urea, urease in stomach made by bacteria breaks it down into LABELED co2, exhaled and quantified
What is the treatment for h.pylori infection?
ANTIBIOTICS
