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Flashcards in afebrile watery diarrhea Deck (35):
1

cholera is.

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

2

Vibrio cholerae

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

3

main V. cholera O Ag type

Type O1
O139 as well

4

Cholera-like illness serotypes

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

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


strain name??

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

O1 El Tor Ogawa

6

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

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

V. cholera spread in ?? mos
risk factor ??

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

8

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

toxemia, sm. intestine, CT enterotoxin

9

V. cholera O1 virulence factors

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

10

cholera vir. factor: TCP

toxin co-reg common pili
need for colonization and is attach. site for CTX? (lysogenic phage containing genes encoding cholera toxin)

11

cholera virulence factors: CT-1 and CT-2

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

cholera virulence factor: MARTX toxin

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

immunity to V. cholera: both ?? and ??
vaccines cross-protect for ??

CD4+ T-cell dependent, IgA
ETEC, O1, NOT O139

14

V. cholera s/s

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

15

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

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

16

classic V. cholera presentation

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

V. cholera dx

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

V. cholera ddx

all abrupt afebrile diarrhea
(base ddx on epidem: food hx, incub. period)

19

V. cholera tx





abx?

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

V. cholera ppx

handle food properly!
vaccine for travel to endemic area

21

Enterotoxigenic E. coli (ETEC)


what color on McConkey?

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

ETEC happens in who?

passed how?
associations?

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

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

fimbriae
enterotoxins

24

ETEC virulence factors

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

what can provide partial immunity to ETEC??
what else provides some protection??

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

26

ETEC self-limiting?

yes

27

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

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

28

ETEC dx: Cx?
ddx

Cx not useful
any afebrile short term diarrhea: cholera, aeromonas, FB agents, use epi to rank

29

ETEC tx
abx?

fluid/e-lyte replacement
abx in sev. cases

30

Enteroaggregative E. coli (EAEC)

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

aeromonas hydrophila
resistant to ??

oxidase positive
Chlorine and refrigeration/cold temps

32

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

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

aeromonas produces...
for how long??
how?

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

34

aeromonas dx: Cx?
ddx

Cx on blood agar with ampicillin
Cholera, ETEC (travs diarrhea) any fresh/brack water contam. food-assoc. afebrile diarrhea of short duration

35

aeromonas tx
aeromonas is typically ??

rehydration
MDR

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