ID IV

Question 0

how does amoeba attak

Answer 0

surface lectin allows trophozoite adherence to colonic epithelium–>invasion–>confers complement resistance (because it prevents complement from binding)

Question 1

entameoba histolytica causes

Answer 1

ulceration of colonic mucosa

Question 2

what does the amoeba do

Answer 2

kill PMN–>liquefy tissues–>cause sterile abscess (can’t grow bacteria on it)

Question 3

what shape are the ulcers

Answer 3

flask shaped

Question 4

how is amoeba transmitted

Answer 4

fecal-oral

Question 5

ameoba looks a lot like…histologically

Answer 5

macrophage

Question 6

pseudomembranous colitis is primarily frm

Answer 6

clostridium difficile

Question 7

clostridium difficile

Answer 7

toxin producing, gram positive, spore-forming anaerobic bacillus

Question 8

spores of cdiff

Answer 8

stable in environment

colonizatin of large bowel after disturbances of normal microbiome (antibiotics)

Question 9

what does c diff produce

Answer 9

cytotoxins A &B

Question 10

symptoms of c diff

Answer 10

diarrhea
pseudomembrane formation (fibrin, inflam cells, bacteria, and dead cells)

Question 11

gram stain of c diff

Answer 11

gram positive

Question 12

pseudomembrane

Answer 12

fibrin, cellular debris, inflammatory cells adherent to colonic mucosa

Question 13

cryptococcal meningitis

Answer 13

encapsulated yeast

Question 14

where is cryptococcal found

Answer 14

high nitrogen soils

aerosol spread

Question 15

toxin in crypto

Answer 15

none

Question 16

viruelnece factor in CM

Answer 16

polysaccharide capsule

Question 17

symptoms of cryptococcal meningitis

Answer 17

cmmon resp infection

immunosuppressed tend to disseminate to meninges, bone, skin

Question 18

time course o CM

Answer 18

gradual onset–>chronic meningitis–>hydrocephalus

Question 19

reservoir of cryptococcus

Answer 19

pigeon droppings

Question 20

how does cryptococcus look in meninges?

Answer 20

transulent, gelatinous

huge number of yeast

Question 21

what do we stain cryptococcus with and what do we see

Answer 21

mucicarmine

detects polysacharides, shows encapsulated yeast forms

Question 22

what else can we stain cryptococcus in cns

Answer 22

melanins tain

Question 23

diagnosis of cryptococcus

Answer 23

stain and India ink prep
antigen detection of secreted polysaccharide in csf or serum- few cross reactions
culture of yeast forms

Question 24

colonies look

Answer 24

brown- represents production of melanin-like compound

Question 25

infectious form is

Answer 25

sporozoite

Question 26

sporozoites are found int he

Answer 26

Anopheles mosquito

Question 27

the bite of the mosquite injects the form that

Answer 27

infects hepatocytes

Question 28

parasite from infects

Answer 28

erythrocytes-->mature in liver-->break out-->infect RBCs-->infected RBCs lyse-->release new infections-->attach to and invaid RBC

Question 29

what infects mosquitos

Answer 29

gametocytes

Question 30

life cycleof malaria

Answer 30

mosquito infects with sporozoite-->matures to merozoite-->enters erythrocytic cycle-->gametocytes reinfect mosquito

Question 31

action of malaria

Answer 31

binding of infected RBC to endothelium by integrin & thrombospondin receptors-->local clogging of small vessels or release of high levels of cytokines may cause acute organ dysfunction

Question 32

clinical features of malaria

Answer 32

``` fever high parasitemia severe anemia renal failure cerebral dysfunction pulmonary edema and death ```

Question 33

malaria morphological change

Answer 33

congestion or enlargement of spleen and liver with deposition of malaria pigment from hemoglobin digestion

Question 34

morphological change of cerebral malaria

Answer 34

small vessels filled with parasitized RBC and have ring hemorrhages little inflammatory infilitrate seen

Question 35

diagnosis of malaria is by

Answer 35

examination of blood films