GI III Flashcards
1
Q
What are the two vibrio species that cause GI disease?
A
Vibrio cholerae
Vibrio Parahaemolyticus
2
Q
What is the gram stain, morphology, and aerobic/anaerobic properties of vibrio genus?
A
Gram negative, comma (curved) facultative anaerobes
3
Q
Where are vibrio species found in the environment?
A
Free-living in water
4
Q
What are the two diseases that vibrio cholerae causes?
A
Gastroenteritis
Bacteremia
5
Q
What are the three diseases that vibrio cholerae causes?
A
Gastroenteristis
Bacteremia
Wound infx
6
Q
What is the nutrient that vibrio species require for growth?
A
NaCl
7
Q
True or false: vibrio grows at a very narrow range of pH
A
False-very broad pH range
8
Q
How fast does cholerae onset?
A
Abruptly
9
Q
How long does cholerae last?
A
7 days
10
Q
What type of stool do pts with cholerae produce?
A
Rice water stool (mucus + electrolytes)
11
Q
How does cholerae spread?
A
Water
12
Q
True or false: there is long term immunity to cholerae
A
True, but there are many serotypes d/t O-antigen changes
13
Q
What is the part of cholerae that is used to type it?
A
O antigen
14
Q
What is the strain of cholerae that is currently causing a pandemic?
A
El Tor
15
Q
What are the two major virulence factors of cholerae?
A
Toxin co-regulated pilus (TCP)
Cholera toxin
16
Q
What type of toxin is the cholerae toxin?
A
AB toxin
17
Q
What is the MOA for cholerae toxin?
A
Activates adenylate cyclase to increase cAMP
18
Q
True or false: there is significant cell damage with cholerae infections
A
False
19
Q
The cholerae toxin works very similarly to what other bacterial toxin?
A
ETEC LT toxin
20
Q
Where did cholerae get its toxin?
A
Via the CTX(phi) prophage
21
Q
How do you diagnose cholerae?
A
Culture with differential media
22
Q
What is the treatment for cholerae?
A
Rehydration (IV if bad)
23
Q
Is vibrio cholera an inflammatory bacteria?
A
No
24
Q
Is vibrio parahaemolyticus an inflammatory bacteria?
A
Yes
25
What is the disease that vibrio parahaemolyticus causes?
Explosive diarrhea, n/v abdo pain
26
What is the virulence factor that vibrio parahaemolytocus produces? How does it produce diarrhea?
Kanagwa hemolysin--induces Cl secretion, thus watery diarrhea
27
What is vibrio parahaemolyticus associated with?
Raw shellfish
28
What is the treatment for vibrio parahaemolyticus?
Supportive
29
Is Yersinia enterocolitica an inflammatory or non-inflammatory bacteria?
Inflammatory
30
What is the gram stain and morphology of Yersinia enterocolitica?
Gram negative coccobacilli
31
Wher eis Yersinia enterocolitica usually found?
Nature and animals
32
What are the symptoms of an infection with Yersinia enterocolitica?
Fever, abdominal cramps, water/bloody diarrhea
33
How long do symptoms of Yersinia enterocolitca last?
1-2 weeks
34
How does Yersinia enterocoliticus cause disease?
Not well understood, but it appears to bind M cells and invade the terminal ileum, producing enterotoxins
35
What is the protein that Yersinia injects into M cells that allows it to enter the cell?
Yops
36
Is the enterotoxin that Yersinia produces heat stable?
Yes
37
How do you diagnose Yersinia enterocolitica infx?
Culture
38
What is the treatment for Yersinia enterocolitica infx?
Supportive
39
What are the gram staining and morhology of C.diff? Aerobic or anaerobic
Gram positive bacilli anaerobic
40
Is C.diff invasive? Does it form spores?
Non-invasive
| DOES form spores
41
Which bacteria causes pseudomembrane colitis?
C.diff
42
What is the pathogenesis of C.diff?
Produces a pseudomembrane that inhibits water reabsorption--this may lead to necrosis
43
What are the three diseases the C.diff can cause?
CDAD
Pseudomembrane colitis
Fulminant colitis
44
Which disease that c.diff causes requires a surgical consult?
Fulminant colitis
45
Is abdominal TTP present with C.diff inx?
Yes
46
What are the symptoms of fulminant colitis aside from diarrhea? (4)
Lethargy, fever, tachycardia, dilated colon
47
What are the symptoms of pseudomembrane colitis?
Same as CDAD, but more severe
48
How does C.diff cause disease?
Produces an AB toxin that damages the mucosa
49
Does infx with C.diff cause an inflammatory response?
yes
50
Which bacterial infection disrupts host cell cytoskeleton to cause diarrhea?
C.diff
51
How do you diagnose C.diff? Why isn't a culture helpful?
Toxin in stool
| NOTE culture is not helpful b/c it is normal flora
52
What is the treatment for c/diff infection?
Oral vanco or metroidazole
53
What is the prevention technique for C.diff?
Fecal transplant
54
Is EHEC inflammatory or noninflammatory pathogen?
Inflammatory
55
What are the gram staining, morphologic, and aerobic/anaerobic characteristics of EHEC?
Gram-negative bacilli, facultative anaerobe
56
Is EHEC an invasive pathogen?
Generally no
57
What are the reservoirs of EHEC?
Cattle or other ruminants
58
What is EHEC associated with?
Beef or veggies washed from rivers/streams
59
What is the disease caused by EHEC?
Hemorrhagic colitis (hematochezia)
60
Is there fever in EHEC infx? Abdominal ttp?
NO fever, but there is marked abdominal TTP
61
What is the sequelae of EHEC?
Hemolytic uremic syndrome (renal failure)
62
What is the pathogenesis of EHEC?
Attaches to epithelium and produces a shiga-like toxin that blocks translation by cleaving part of the 60S subunit of the ribosome
63
How does EHEC cause HUS?
The shiga toxin attaches to Gb3, which the kidney is rich in
64
How do you diagnose EHEC? (3)
Presumtive (diarrhea WITHOUT fever)
Culture
PCR
65
What is the treatment for EHEC?
Supportive
| Abx Is harmful
66
For which bacterial infx of the large intestine is the use of abx absolutely contraindicated?
EHEC and non-typhoidal Salmonella
67
How do you prevent EHEC infx?
Properly cook hamburger
68
A pt comes in complaining of diarrhea, abdominal pain after eating a hamburger earlier in the day. A fever is absent. What is your diagnosis?
EHEC
69
Why is the use of abx contraindicated for EHEC infx?
Damages bacteria, and activates phage/toxin production
70
Is shigella an inflammatory or noninflammatory bacteria?
Inflammatory
71
What is the gram stain of shigella? Morphology? Aerobic or anaerobic?
Gram negative rods, facultative anaerobe
72
True or false: humans are the only reservoir for shigella
True
73
Which bacteria discussed in lecture is acid resistant, and thus requires a low inoculation dose?
Shigella
74
What are the three intracellular pathogens discussed in lecture?
Shigella, listeria , and EIEC
75
What are the three species of shigella? Which is found in developed, developing, and underdeveloped countries?
Developed - S. soneii
Developing - S. Flexneri
Underdeveloped - S. Dysentariae
76
What is shigella associated with in developed nations? Why?
Day care centers because children are disgusting
77
How long does shigella infx last?
2-5 days
78
What are the symptoms of infx with S. sonneii?
Fever, malaise, and water diarrhea
79
What are the symptoms of infx with S. flexerni and S. dysenteriae?
Fever, malaise, watery diarrhea, abdo pain, tenesmus, hematochezia
80
What is the cell type that shigella infects?
M cells in peyer's patches
81
What happens once shigella infects M cells?
Eaten by macrophages, then bust out and do stuff
82
Shigella is intracellular motile like which pathogen discussed earlier? What allows for this?
Listeria
Actin polymerization
83
How does salmonella induce its own uptake into M cells?
T3 secretion systems
84
How does the shiga toxin produce renal failure?
binds to host Gb3 receptor on kidneys
85
What is the MOA of shigella toxin?
Inhibits translation
86
How do you diagnose shigella?
Stool culture using selective media
Serological testing
87
What is the treatment for shigella?
Rehydration
Abx if you want
88
Does infection with shigella confer immunity?
No
89
Is there a vaccine available for shigella?
No
90
Is EIEC an inflammatory or noninflammatory bacteria?
Inflammatory
91
EIEC has the same MOA of pathogenesis as what other bacteria? Why?
Shigella
Picked up the toxin from shigella
92
What three bacterial infections do not cause fevers?
ETEC
V cholerae
EHEC
93
What three bacterial infections always cause bloody diarrhea?
EHEC
Shigella
EIEC
94
Which strain of E.coli has a shiga-like toxin?
EHEC
95
Which strain of E.coli has a similar pathogenesis to shigella, but does not have a shiga toxin?
EIEC
96
What are the toxins produced by ETEC?
LT and ST (cAMP and cGMP respectively)
97
Pus/blood stools are associated with which bacterial infections?
Shigella
| EIEC
98
HUS is a problem with which bateria?
EHEC
| Shigella
99
What is the toxin that Listeria produces?
LLO
100
Which bacterial infx can be transmitted from mother to fetus?
Listeria
