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Flashcards in afebrile watery diarrhea Deck (35)
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1
Q

cholera is.

A

acute illness via enterotoxin colonizing mucosal surface of small bowl
rapid loss of fluid and e-lytes–>hypovolemic shock, metab. acidosis, death

2
Q

Vibrio cholerae

A

G-, ox positive facultative anaerobe, salt-loving, curved rod
common H Ag
EC, noninvasive
biofilm matrix proteins: RbmA, Bap1, RbmC

3
Q

main V. cholera O Ag type

A

Type O1

O139 as well

4
Q

Cholera-like illness serotypes

A
O141, O75 (US)
O37, O10, O12, O6, O14 (world)
serotype changes from lateral transfer of gene cassettes
El Tor strain pandemic, Haiti epidemic
inc. virulence
5
Q

new strain of cholera resistant to ?? found in ??
2 super bug genes

strain name??

A

3rd generation Abs, India
New Delhi Metallo B-lactamase-1 (blaNDM-1)
plasmid-med B lactamase-1 (blaDHA-1)

O1 El Tor Ogawa

6
Q

V. cholera transmission: different infectious doses for person-person vs environ. spread

A

person-person
hyperinfectious state of rice-water feces for 5 hours

from environment, food-borne, contam. food/water
high infectious does: 10^6-8 bac

7
Q

V. cholera spread in ?? mos

risk factor ??

A
warm mos: that don't have an "R"
contaminate shellfish (w/bicarb or food: inf. dose drops to 10^4)
8
Q

cholera is a ??? therefore multiply in and adhere to ?? producing ??

A

toxemia, sm. intestine, CT enterotoxin

9
Q

V. cholera O1 virulence factors

A

TCP*
CT-1, CT-2*
MARTX toxins
*not all genes that carry 1 or both(1st 2) of these genes cause cholera

10
Q

cholera vir. factor: TCP

A

toxin co-reg common pili

need for colonization and is attach. site for CTX? (lysogenic phage containing genes encoding cholera toxin)

11
Q

cholera virulence factors: CT-1 and CT-2

A

cholera enterotoxins
cause of diarrhea, heat-labile, bind Gm1 ganglioside–>inactivation of GTPase–>inc. cAMP production–>hyper sec. of Cl- and bicarb–>H2O follows from cell

12
Q

cholera virulence factor: MARTX toxin

A

multifunctional-autoprocessing repeats-in-toxins
produced by most isolates
disrupts actin cytoskeleton–>either? allows colonization/reduces functionality of innate immune cells preventing clearance, aides extra intestinal survival
rel. to C. diff toxin B

13
Q

immunity to V. cholera: both ?? and ??

vaccines cross-protect for ??

A

CD4+ T-cell dependent, IgA

ETEC, O1, NOT O139

14
Q

V. cholera s/s

A

mild diarrhea–>fatal (hypovolemic shock, hemoconc., K depletion, loss of bicarb, sev. acidosis

15
Q

V. cholera incubation period
diarrhea time frame
fever ?
disease course ?

A

1-5 days, then abrupt
diarrhea for 1-3 days
typically NO fever
may run 1-7 days

16
Q

classic V. cholera presentation

A

effortless vomiting, watery diarrhea (“rice water” appearance, flecks of floating mucus), musc. crapms, poor turgor, “absent” periph. pulse, sunken eyes, wrinkled skin, cyanosis, fishy odor–>60% mort. w. out tx!

17
Q

V. cholera dx

A

abrupt afebrile watery diarrhea assoc. with eating shellfish
10^6-10^8 vibrios/mL in rice stools (microscopic)
Cx: spec. request media
serology: rapid slide test, serotype

18
Q

V. cholera ddx

A

all abrupt afebrile diarrhea

base ddx on epidem: food hx, incub. period

19
Q

V. cholera tx

abx?

A

enteric isolation
initial rehydration IV: 5gm NaCl 4 gm NaHCO3, 1 gm KCl in 1L H20
oral admin of gluc-e-lyte solution, amylase-res. starch (SCFA-prod in colon, stim. Na absorption)

abx only for sev. dehydration, also Zn supple.

20
Q

V. cholera ppx

A

handle food properly!

vaccine for travel to endemic area

21
Q

Enterotoxigenic E. coli (ETEC)

what color on McConkey?

A

G- rod, motile by flagella (H Ag) or non-motile, non-fastidious, facultative anaerobe, oxidase negative
coliform: ferments lactose with acid and gas production
PINK on McConkey agar

22
Q

ETEC happens in who?

passed how?
associations?

A

traveler’s diarrhea, weanling diarrhea, food and water borne outbreaks ww
fecal-oral, reservoir is GIT of humans/animals
no gender/season assoc
risk factor: poor sanitation

23
Q

ETEC has ?? that allows them to attach to sm. bowel and secrete ?? causing mucosal cells to secrete fluids and e-lytes

A

fimbriae

enterotoxins

24
Q

ETEC virulence factors

A

colonization factor Ag (CFA) fimbriae: adherence
enterotoxins:
LT (heat labile): like Cholera toxin (CT), inc. cAMP
ST (heat stable): binds GC–>inc. cGMP–>phos/act. Cl channel–>Cl secretion, inhib. of Na uptake

25
Q

what can provide partial immunity to ETEC??

what else provides some protection??

A
cholera vaccine
bismuth subsalicylate (4tabs/day) +/- abx for travelers
26
Q

ETEC self-limiting?

A

yes

27
Q

ETEC infectious dose??
onset??
duration?? fever?

A

HIGH: 10^6-10^8
abrupt onset: 1-2 day incubation period
diarrhea for 1-3 days, no fever

28
Q

ETEC dx: Cx?

ddx

A

Cx not useful

any afebrile short term diarrhea: cholera, aeromonas, FB agents, use epi to rank

29
Q

ETEC tx

abx?

A

fluid/e-lyte replacement

abx in sev. cases

30
Q

Enteroaggregative E. coli (EAEC)

A

adhere to epithelial cells: HEp-2 in a “stacked-brick” pattern

unknown how it causes diarrhea, new strains can produce Shiga toxins

cause persistent watery diarrhea
reservoir: human GIT

31
Q

aeromonas hydrophila

resistant to ??

A

oxidase positive

Chlorine and refrigeration/cold temps

32
Q

aeromonas causes what??
transmitted how ??
live where ??

A

up to 13% reported gastroenteritis cases in US
fecal-oral
fresh water, ubiquitous: environ/clinic/food
can survive and multiply at low temps
unknown infectious dose

33
Q

aeromonas produces…
for how long??
how?

A

profuse afebrile watery diarrhea
about 3 days duration
produces enterotoxin (like CT)

34
Q

aeromonas dx: Cx?

ddx

A

Cx on blood agar with ampicillin

Cholera, ETEC (travs diarrhea) any fresh/brack water contam. food-assoc. afebrile diarrhea of short duration

35
Q

aeromonas tx

aeromonas is typically ??

A

rehydration

MDR

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