Microbiology-Bacteria Flashcards Preview

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Flashcards in Microbiology-Bacteria Deck (52):
1

bacterial structures that induce TNF and IL1

Liptechoic acid (cell wall component unique to gram+); Lipid A (o polysaccharide antigen unique to gram - )

2

contains D-glutamate in capsule

Bacillus anthracis

3

cell membrane with sterols, no cell wall

mycoplasma

4

cell walls/membrane contain mycolic acid with high lipid content

mycobacteria

5

Bugs that do not gram stain well:

Treponema, mycobacteria, mycoplasma, Legionella, Rickettsia, Chlamydia (these microbes may lack real color)

6

Giemsa stain

Chlamydia, borrelia, rickettsiae, trypanosomes, plasmodium (Certain bugs really try my patience)

7

PAS stain

stains glycogen (used to diagnose Tropheryma whipplei)

8

Ziehl Neelsen stain (carbol fuchsin)

Acid fast organisms like nocardia or mycobacterium

9

India ink

cryptococcus neoformans (mucicarmine can stain capsule red)

10

Silver stain

Fungi (pneumocystis), legionella, helicobacter pylori

11

H influenzae growth requirements:

Chocolate agar containing NAD+ and hematin

12

Neisseria gonorrhea, Neisseria meningitidis growth requirements

Thayer Martin (VPN media) vancomycin, polymyxin, nystastin

13

Bordatella pertussis growth requirements

Bordet Gengou potato agar

14

C diptheriae growth requirements

tellurite agar, loffler medium

15

M tuberculosis growth requirements

Lowenstein Jensen agar

16

M pneumoniae growth requirements

Eaton agar, requires cholesterol

17

Lactose fermenting enterics growth requirements

pink colonies on macConkey agar (fermentation produces acid, turning colony pink); E coli is also grown on eosin methylene blue agar as colonies with green metallic sheen

18

Legionella growth requirements

charcoal yeast extract agar buffered with cystein and iron

19

fungi growth requirements growth requirements

sabouraud agar

20

What are some obligate aerobes?

Nocardia, Pseudomonas, MycoBacterium (nagging pests must breath)

21

What are some obligate anaerobes?

Closteridium, Bacteroides, actinomyces (can't breath air)

22

antibiotic that requires O2 to enter bacterial cell?

amino2glycosides; ineffective against anaerobes

23

Obligate intracellular

rickettsia, chlamydia (can't make own ATP)

24

Facultative intracellular

Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis

25

bacteria opsonized and cleared by spleen

Encapsulated bacteria: streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis, E coli, Salmonella, Klebsiella pneumoniae, group B strep (SHiNE, SKiS)

26

Which vaccinations to give asplenics?

S pneumo, H influ, N meningitidis vaccinations, which are conjugate vaccines that have polysaccharide capsule antigens conjugated to a carrier protein to enhance immunogenicity

27

NADPH oxidase deficient person is susceptible to..?

CGD, recurrent infections with catalase positive organisms: Psuedomonas, Listeria, Aspergillus, Candida, E coli, S aureus, Serratia (PLACESS for your cats)

28

Urease positive bugs

Cryptococcus, H pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S epidermidis, S saprophyticus

29

yellow sulfur granules w/ filaments of bacteria

actinomyces israelii (israel has yellow sand)

30

yellow pigment

S aureus (Au = gold)

31

blue green pigment

Pseudomonas aeruginosa (aerugula is green)

32

red pigment

Serratia marascens (maraschino cherries are red)

33

Protein A

Binds Fc region of IgG and prevents opsonization and phagocytosis--expressed by S aureus

34

IgA proteus

Enzyme that cleaves IgA; secreted by S pneumoniae, HiB, Neisseria (SHiN) to colonize respiratory mucosa

35

M protein

prevents phagocytosis--group A streptococci; binds to serum factor H, destroying C3-convertase and preventing opsonization by C3b; plasma B cells can generate antibodies against M protein which will help in opsonization and further the destruction of the microorganism by the macrophages and neutrophilis. Cross-reactivity of anti-M protein antibodies with heart muscle is the basis for rheumatic fever

36

Exotoxin vs Endotoxin heat stability?

Exotoxins are destroyed rapidly at 60 C except for Staph enterotoxin. Endotoxins are stable at 100 C for 1 hr.

37

Pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck)

Corynebacterium diphtheriae: diptheria toxin--inactivate elongation factor (EF-2)-->inhibit protein synthesis; ADP ribosylating A-B toxin

38

Toxin released by pseudomonas aeruginosa

Exotoxin A: inactivates EF2-->inhibit protein synthesis, ADP ribosylating A-B toxin

39

GI mucosal damage resulting in dysentery; also causes HUS

Shigella (shiga toxin)--inactivates 60S ribosome by removing adenine from rRNA; cytokine release-->HUS; ADP-ribosylating A-B toxin

40

causes HUS, but does not invade host cells (unlike Shigella)

EHEC (O157:H7)--shiga like toxin--inactivates 60S ribosome by removing adenine from rRNA; cytokine release-->HUS; ADP ribosylating A-B toxin

41

watery diarrhea, E coli toxin

ETEC: heat labile toxin--overactivates adenylate cyclase--increased chloride secretion in guy and water efflux; heat stable toxin overactivates guanylate cyclase-->decreases resorption of NaCl and H2O in guy

42

toxin likely responsible for characteristic edematous borders of black eschar in cutaneous anthrax

bacillus anthacis--edema factor--mimcs adenylate cyclase enzyme--increases cAMP

43

voluminous rice water diarrhea

vibrio cholerae--cholera toxin--overactivates adenylate cyclase by permanently activating Gs-->increased Cl secretion in gut and water efflux; ADP ribosylating A-B toxin

44

toxin that released by bacteria associated with whooping cough

bordatella pertussis--pertussis toxin--overactivates adenylate cyclase by disabling Gi, impairs phagocytosis to permit microbe survival

45

spasticity, risus sardonicus, "lockjaw"

Clostridium tetani--tetanospasmin--protease that cleave SNARE proteins required for neurotransmitter release; prevents release of inhibitory GABA/glycine from Renshaw cells in spinal cord

46

Flaccid paralysis, floppy baby,

clostridium botulinum--botulinum toxin--protease that cleave SNARE proteins required for neurotransmitter release; prevents release of stimulatory Ach signals at NMJ-->flaccid paralysis

47

myonecrosis (gas gangrene) and hemolysis (double zone on blood agar)

Clostridium perfringens--alpha toxin--phospholipase (lecithinase) that degrades tissue and cell membranes

48

hemolysis, ASO used to diagnose rhematic fever

streptococcus pyogenes--streptolysin O--protein that degrades cell membrane--lyses RBCs

49

toxic shock syndrome, scalded skin syndrome

staph aureus--toxic shock snydrome toxin (TSST-1); brings MHCII and TCR in proximity to outside of antigen binding site to cause overwhelming release of IFN-gamma and IL2-->shock

50

toxic shock syndrome: fever rash shock

streptococcus pyogenes (exotoxin A); same mechanism of action as TSST-1

51

Endotoxin (gram negatives) has what actions?

activates macrophages--IL1, TNF, NO; activates complement--C3a, C5a; activates tissue factor--coagulation cascade/DIC

52

which bacterial toxins are encoded in a lysogenic phage

ABCDE: ShigA-like toxin, Botulinum toxin, Cholera toxin, Diptheria toxin, Erythrogenic toxin of Strep Pyogenes (Strep O)