Micro

Question 1

S. bovis

Answer 1

Colonizes gut; can cause bacteremia and subacute endocarditis , associated w/ colon cancer
“bovis in the blood, cancer in the colon”

Question 2

Diphtheria caused by

Answer 2

Exotoxin encoded by beta prophage.

Inhibits protein synthesis via ADP-ribosylation of EF-2 (elongation factor)

Question 3

Sxs of diphtheria

Answer 3

pseudomembranous pharyngitis w/ LAD, myocarditis, arrhythmias

Question 4

Black colonies on cystine-tellurite agar

Answer 4

diphtheria

Question 5

Diphtheria ABDEFG mnemonic

Answer 5

ADP-ribosylation
Beta prophage
Corynebacterium
Diphtheriae
Elongation Factor 2
Granules (lab dx based on G+ rods with metachroniatic granules and +Elek test for toxin)

Question 6

Scabies

Answer 6

intensely pruritic rash on flexor surfaces of wrist, lateral surface of fingers, finger webs. Usually worse at night due to delayed type IV hypersensitivity rx to mite, mite fees/eggs.

Linear burrows are most specific finding.

Question 7

Multinucleated giant cells

Answer 7

Herpes, shingles

Question 8

Necrotic keratinocytes

Answer 8

stevens johnson syndrome

s/p CMV, mycoplasma, or drug exposure

Question 9

What antibiotic treats diphtheria

Answer 9

penicillin
also need to give the antitoxin
(and DPT vaccine but this doesn’t help active infx)

Question 10

paramyxovirus

Answer 10

measles

Question 11

togaviruses

Answer 11

Rubella (congenital, childhood, adult)

Arbovirus: Western/Eastern/Venezuelan equine encephalitis

Question 12

Vibrio Cholerae

Answer 12

comma shaped, oxidase positive
gram negative bacillus
grow on alkaline selective media (thiosulfate-citrate-bile salts-sucrose aka TCBS agar)
More infective in alkaline situations (ppl on PPIs)

Question 13

bacillary angiomatosis

Answer 13

skin infx caused by cat scratch disease aka bartonella

immunocompromised patients need erythromycin or doxy; can be fatal

Question 14

c perfringens toxin

Answer 14

lecithinase aka alpha toxin

degrades lecithin in phospholipid membranes

Question 15

What is O antigen

Answer 15

found on outer membrane of gram neg bacteria, most extracellular component of LPS

Question 16

how do super antigens work

Answer 16

bind to T cell receptor and MHC class II on APCs, leading to widespread T cell stimulation and inflammation

Question 17

How does LOS (neisseria meningitides) work

Answer 17

induces production of TNF-a, IL-1B, IL-6, IL-8 via interaction with TLR4

Question 18

toxin from scalded skin syndrome does what

Answer 18

cleaves desmoglein in desmosomes

Question 19

bacitracin test sometimes replaced by which

Answer 19

PYR test
PYR + is GAS
PYR - is GBS

Question 20

proofreading of DNA goes which direction

Answer 20

3’–>5’

Question 21

how to tell difference between e coli UTI and enterobacter colacae

Answer 21

e coli is indole positive

Question 22

what reproductive process can segmented viruses participate in?

Answer 22

Reassortment - refers to changes in genomic composition that occur when host cells are connected with two segmented viruses that can exchange whole genome sequences.

Question 23

what are the four segmented viruses

Answer 23

BOAR: bunyavirus, orthomixovirus (flu), arenavirus, reovirus

Question 24

p53 gene does what

Answer 24

stops cells at G1/S phase to allow for DNA fixing

Question 25

Fluoroquinolones MOA

Answer 25

disrupt DNA winding-unwinding

Question 26

Bactrim MOA

Answer 26

blocks folic acid metabolism

Question 27

vancomycin MOA

Answer 27

binds to D-alanyl-D-alanine portion of cell wall precursors, blocking glycopeptide polymerization and inhibiting bacterial cell wall synthesis

Question 28

Linezolid MOA

Answer 28

inhibits bacterial protein synthesis by binding to 23S ribosomal RNA of 50S subunit. - prevents ribosomal formation

Question 29

daptomycin MOA

Answer 29

causes depolarization of bacterial cellular membrane and inhibition of DNA, RNA, and protein synthesis assoc w/ elevated CPK

Question 30

HPV 6/11 prefer what kind of cells

Answer 30

stratified squamous epithelium: anal canal, vagina, cervix, and vocal cords (obviously this is SUPER high yield)

Question 31

norepinephrine has minimal effect on what type of receptors?

Answer 31

beta 2

Question 32

cyanide nitroprusside urine test

Answer 32

a qualitative test for diagnosis of cystinuria; the addition of fresh sodium cyanide formed by sodium nitroprusside to a sample of urine gives rise to a stable red-purple color in the presence of cystine.

Question 33

Winter's formula

Answer 33

predicts res compensation for met acidosis | Pco2 = 1.5 [HCO3-] + 8 +/- 2

Question 34

mnemonic for high AG acidosis

Answer 34

MUDPILES | Methanol, uremia, DKA, propylene glycol, iron/isoniazid, lactate, ethylene glycol, salicylate (late)

Question 35

mnemonic for non-AG acidosis

Answer 35

``` HARD ASS Hyperalimentation Addison's RTA Diarrhea Acetazolamide Spironolactone Saline infusion ```