Micro Flashcards Preview

First Aid Diseases > Micro > Flashcards

Flashcards in Micro Deck (105):
1

2 bac w/ weird cell walls?

Mycoplasma - contains sterols, no cell wall
Mycobacteria - contains mycolic acid, high lipid content

2

Bugs that don't Gm stain well

"These Rascals May Microscopically Lack Color"
Treponema (to thin, use fluorescent Ab)
Rickettsia (IC)
Mycobac (high lipid content, use carbolfuchsin in acid-fast stain)
Mycopl (no cell wall)
Legionella (mainly IC, use silver stain)
Chlamydia (IC, no muramic acid in cell wall)

3

Do Giemsa stain on...

"Certain Bugs Really TRY my Patience"
Chlamydia, Borrelia, Rickettsiae, TRYpanosomes, Plasmodium

4

PAS stains what?
- used to dx?

"PAS the sugar"
glycogen, mycopolysaccharides
- Whipple's dz (Tropheryma whipplei)

5

Ziehl-Neelsen (carbol fuchsin) stains?

acid-fast org's (Nocardia, Mycobac)

6

India ink stains?
- Can also use for this bug?

Cryptococcus neoformans
- mucicarmine to stain thick polysacch. cap red

7

Silver stain is used for?

Fungi (PCP), Legionella, H. pylori

8

How do you culture H. influenzae?

chocolate agar w/ factors V (NAD+) and X (hematin)

9

How do you culture Neisseria (gonorrhoeae and meningitidis)?

Thayer-Martin (or VPN) media:
Vanc (inhib's Gm+)
Polymixin (inhib's Gm- except Neisseria)
Nystatin (inhib's fungi)

10

How do you culture B. pertussis?

Bordet-Gengou (potato) agar

11

How do you culture C. diphtheriae?

Tellurite plate, Loffler's media

12

How do you culture M.Tb?

Lowenstein-Jensen agar

13

How do you culture M. pneumoniae?

Eaton's agar

14

How do you culture lac-fermenting enterics?
- Can also grow E.coli on?

Pink colonies on MacConkey's agar (fermentation makes acid to turn it pink)
- On EMB (eosin-methylene blue) agar as colonies w/ green metallic sheen

15

How do you culture Legionella?

charcoal yeast extract agar buffered w/ Cys and Fe

16

How do you culture fungi?

"SAB's a FUN GUY"
Sabouraud's agar

17

Obligate aerobes?
Obligate anaerobes?

"Nagging Pests Must Breathe"
Nocardia, Pseudomonas, MTb, Bacillus

"Can't Breathe Air"
Clostridium, Bacteroides, Actinomyces

18

Obligate IC bugs

Rickettsia and Chlamydia

19

Facultative IC bugs

"Some Nasty Bugs May Live FacultativeLY"
Salmonella, Neisseria, Brucella, Mycobac, Listeria, Francisella, Legionella, Yersinia pestis

20

Positive quelling rxn is for who?

Encap'd bac (cap's swells w/ antisera)
"SHiNE SKiS"
Strep. pneumo, Hib, Neisseria meningitidis, E. coli, Salmonella, Klebsiella, GpBStrep

21

Cat(+) bugs

"PLACESS for your cats"
Pseudomonas, Listeria, Aspergillus, Candida, E.coli, S.aureus, Serratia
and Nocardia

22

Urease-pos bugs

"CHuck norris hates PUNKSS"
Cryptococcus, H.pylori, Proteus, Ureaplasma, Nocardia, Klebsiella, S.epidermidis, S.saprophyticus

23

Protein A virulence factor:
exp'd by who? does what?

S.aureus
- binds Fc of Ig to prevent opsonization and phagocytosis

24

IgA protease virulence factor:
exp'd by who? does what?

these org's also have ability to?

SHiN = S.pneumo, HiB, Neisseria
- cleaves IgA -> can colonize resp mucosa

- take up naked DNA = transformation = competence

25

M pr virulence factor:
exp'd by who? does what?
- Abs to it can cause what?

GAS
- helps prevent phagocytosis by inhib'ing C'
- RF

26

Diphtheria toxin -> ?

inact's EF2 -> inhib's pr syn via ADP-ribosylation of EF2 -> pharyngitis w/ pseudomem's in throat and severe lymphadenopathy (bull neck)
- AB toxin

27

Pseudomonas Exotoxin A -> ?
- also has what other toxin?

inact's EF2 -> host cell death (AB toxin)
- endotoxin -> F, shock

28

Shigella Shiga toxin -> ?

inact's 60S by removing A from rRNA -> GI mucosal damage, dysentery; cytokine release -> HUS

29

EHEC O157:H7 Shiga-like toxin (SLT) -> ?

inact's 60S by removing A from rRNA -> cytokine release causing HUS; doesn't invade host cells (unlike Shigella)

30

ETEC (enterotoxigenic E.coli) LT (heat-labile toxin) -> ?

incr'd cAMP -> incr'd Cl and H2O out into gut -> watery D
[Labile in the Air (cAmp)]
- AB toxin

31

ETEC ST (heat-stable toxin) -> ?

incr'd cGMP -> decr'd reab'n of NaCl and water in gut -> watery D
[Stable on the Ground (cGmp)]
- AB toxin

32

Bacillus anthracis Edema factor -> ?
(Lethal factor also contributes to this sx)

like AC, incr's cAMP -> edematous borders of black eschar in cut anthrax

33

Vibrio cholerae, Cholera toxin -> ?

permanently act's Gs -> incr'd AC and cAMP -> incr'd Cl and water efflux into gut -> "rice-water D"
- AB toxin

34

Bordatella pertussis, pertussis toxin -> ?

disable's Gi -> incr's AC and cAMP -> impairs phagocytosis -> Whooping cough
- AB toxin

35

Clostridium tetani, tetanospasmin -> ?

cleaves SNARE pr needed for nt release -> m. rigidity and lock jaw bc prevents release of inhib GABA and Gly nt's from Renshaw cells in SC

36

Clostridium botulinum, Botulinum toxin -> ?

heat labile toxin that cleaves SNARE pr needed for nt release -> flaccid paralysis (floppy baby) bc prevents release of ACh at NMJ

37

Clostridium perfringens, alpha toxin -> ?

phospholipase (lecithinase) that degrades tissue and cell mem's -> degrades phospholipid C -> myonecrosis (gas gangrene) and hemolysis (2x zone of hemolysis on bl agar)

38

Strep.pyogenes, Streptolysin O -> ?
- ASO Abs used to dx?

Strep.pyogenes, Exotoxin A -> ?

pr that degrades cell mem -> lyses RBCs (b-hemolysis)
- RF

brings MHC-II and TCR together -> release of IFN-g and IL-2 -> shock (F, rash, shock)

39

S.aureus, TSST-1 -> ?
- sx?
- exfoliative toxin ->
- enterotoxin ->

brings MHC-II and TCR together -> polyclonal Tcell act'n -> release of IFN-g and IL-2 -> shock
- sx: F, rash, shock
- scalded skin syndrome
- food poisoning

40

Endotoxin (LPS on Gm-):
- act's Mphage ->
- act's C' ->
- act's TF ->

- IL-1 (F), TNF (F and hypotension), NO (hypotension)
- C3a (hypotension, edema), C5a (N's)
- coag cascade -> DIC

41

Endotoxin -> what sx?

"ENDOTOXIN"
Edema, NO, DIC/Death, Outer mem, TNF-a, eXtremely heat stable, IL-1, N chemotaxis

42

5 bac toxins encoded in a lysogenic phage:

"ABCDE"
ShigA-like toxin (EHEC O157:H7)
Botulinum toxin
Cholera toxin
Diphtheria toxin
Erythrogenic toxin of S.pyogenes (Streptolysin O, brks dwn cell mem's, inc'ing of RBCs)

43

S. pneumo is most common cause of?

"MOPS"
Meningitis
Otitis media in kids
Pneumonia
Sinusitis

44

Scarlet fever
- caused by?
- sx?

S. pyogenes (GAS)
- scarlet sandpaper-like rash sparing face, strawberry (scarlet) tongue after white exudate peels off, scarlet sore throat, F

45

GBS makes CAMP factor which does what?
- Test for GBS?

Enlarges area of hemolysis formed by S.aureus
- hippurate test positive (can hydrolyse sodium hippurate)

46

Bac for meningitis <2yo?, for adults?

Listeria > E.coli > GBS
N. meningitidis > H.flue

47

How do you dx C. diphtheriae?
- grows on?

Gm+ rods w/ metachromatic (blue and red) granules and Elek's test for exotoxin
- blk colonies on cystine-tellurite agar OR on Loeffler's coag'd bl serum then stain w/ methylene blue to see bac

48

C. diphtheriae properties?

ABCDEFG
ADP-ribosylation (of EF2 to inact it)
B-prophage (carries exotoxin)
Corynebacterium
Diphtheria
EF2 (what exotoxin inact's) (Elek's test for it toxin)
Granules (metachromatic)

49

Which Gm+ bac form spores (found in soil)?
What are 3 others?

Bacillus anthracis, C.perfringens, C.tetani
- B.cereus, C.botulinum, Coxiella burnetii

50

Only bac w/ polypep capsule (containing D-Glutamate)?

Bacillus anthracis

51

Woolsorters' dz =

inhal of B. anthracis (anthrax) spores from contaminated wool; flu sx that rapidly progress to pulm hemorrhage, mediastinitis and shock

52

Actinomyces vs. Nocardia
- air? acid fast?
- found in?
- causes?
- trt w/?

- anaerobe vs. aerobe; no vs. partially
- nl oral flora vs. soil
- oral/facial abscesses that drain thr sinus tracts -> yellow sulfur granules VS. pulm infec's in immcomp'd and cut infec's post trauma in nl ppl
- Pn vs. sulfonamides

53

Mycobac:
- M. kansaii causes?
- M.avium-intracellulare causes? drug?
- Cord factor inhib's?
- Sulfatides inhib?

- pulm TB-like sx
- disseminated non-TB dz in AIDS; prophylaxis w/ azithromycin
- inhib's Mphage maturation and induces release of TNF-a
- are surface gp's that inhibs phagolysosomal fusion

54

Mycobac leprae
- infects where?
- which type has pos lepromin skin test?
- trtmt

- likes cool T's -> infec's skin and superficial n's -> glove and stocking loss of sensation
- Tuberculoid type bc high CMI and lg Th1 response vs. low CMI w/ humoral Th2 response in lepromatous
- Tuberculoid: dapsone + rifampin for 6mo
Lepromatous: dapsone + rifampin + clofazimine for 2-5yrs

55

Lactose fermenting bac (pink on MacConkey's agar) (5 bac)
- on EMB agar they grow as?

CEKES lactose
Citrobacter, Enterobacter, Klebsiella, E.coli, Serratia
- purple/blk colonies; E.coli grows purple w/ green sheen

56

What abx do not work on Gm- bugs? Which do?

PnG and vanc (can't X outer mem)
- Pn deriv's like amp/amox

57

Trtmt of N. meningitidis vs. N. gonorrhoeae?

Ceftriaxone or PnG AND trt close contacts w/ rifampin, cipro or ceftriaxone
vs. Ceftriaxone (+ azithromycin or doxycycline for possible Chlamydia coinfec)

58

H.flue
- Causes?
- Non typable strains cause?
- Grow it on?
- Trt w/?

- HaEMOPhilus: Epiglottitis, Meningitis, Otitis media, Pneumo
- mucosal infec's: otitis media, conjunctivitis, bronchitis
- "When you get the flu, mom goes to the 5&dime to buy chocolate" = Chocolate agar + Factor V (NAD+, S.aureus can make) and X (hematin)
- Meningitis w/ ceftriaxone and rifampin to close contacts

59

Legionella
- grows on?
- labs show?
- trt w/

- charcoal yeast extract w/ Fe and Cysteine
- hypoNa
- quinolone or macrolide

60

Pseudomonas can cause?
- Trtmt?

BE PSEUDDO = Burn wound infec's, Endocarditis, Pneumo (esp in CF, biofilm), Sepsis (blk lesions on skin), Ext. otitis media, UTI (pyelo), Drug use, Diabetic Osteomyelitis
- aminoglycosides + big Pn (Piperacillin, ticarcillin)

61

3 E.coli VFs?

1) fimbriae (cystitis and pyelo)
2) K capsule (pneumo, neonatal meningitis)
3) LPS endotox (septic shock)

62

4 A's of Klebsiella:

Aspiration pneumo
Abscess in lungs/liver
Alcoholics
di-A-betics

63

Typhoid F
- caused by?
- sx?
- can stay in?

- Salmonella typhi
- rose spots on ab, F, HA, D
- GB -> carrier state (Typhoid Mary)

64

3x tx for H.pylori
- pt's w/ it are at incr'd risk for?

PPI, clarithromycin, amox or metronidazole
- PUD, gastric adenoca, lymphoma

65

What are the 3 spirochetes?
How do you visualize them?

BIG = Borrelia (Big size), Leptospira, Treponema
- Borrelia - aniline dye (Wright's or Giemsa stain)
- Treponema by dark-field microscopy

66

Leptospirosis presents as?
- Severe form is?

flu-like sx w/ jaundice and photophobia w/ conjunctivitis (surfers and tropics bc is from animal urine in water)
- Weil's dz = jaundice and azotemia (bad liver and kidney), F, hemorrhage, anemia

67

Lyme dz: 3 stages?
Trtmt?

1) erythema chronicum migrans (red rash w/ central clearing), flu sx
2) neuro (facial n. palsy) and cardiac (AV node block)
3) MSK (chronic monoarthritis and migratory polyarthritis), neuro (encephalopathy and polyneuropathy), and cut sx
- Doxycycline or ceftriaxone

68

Congenital syphilis presents as?
- Passes to fetus, when?

Saber shins, saddle nose, CN VIII deafness, Hutchinson's teeth, mulberry molars
- after 1st trimester

69

VDRL tests for?
- used to dx?
- false pos's?

nonsp Ab that rcts w/ beef cardiolipin
- syphilis
- VDRL: Viruses (mono, hepatitis); Drugs, Rheumatic f., Lupus/Leprosy

70

Jarisch-Herxheimer rxn =

flu-like synd immediately after starting abx due to killed bac releasing pyrogens

71

Syphilis: Rule of 6s:

Six - Sexual trans
6 axial filaments
6 wk incubation
6 wks for ulcer to heal
6 wks after ulcer heals progresses to 2* syph
6 wks for 2* syph to resolve
66% of latent stage pt's have resolution
6 yrs to develop 3* syph (at least)

72

RMSF =
- Bac needs what to grow?
- classic triad?
- rash is?

From Rickettsia rickettsii; obligate IC org
- CoA and NAD+
- HA, F, rash (vasculitis)
- starts at wrists/ankles, spreads to trunk, palms and soles

73

Typhus
- Endemic type spread by?
- Epidemic type spread by?
- Rash is?

- R. typhi on fleas
- R. prowazekii from human body louse
- Starts centrally on trunk, spreads out but NOT to palms and soles

74

Ehrlichiosis
- spread by
- histo shows

spread by tick
- monocytes w/ morula (berry-like inclusions) in cyto

75

Anaplasmosis
- spread by
- histo shows

spread by tick
- granuloctes w/ morula in cyto

76

Q fever
- spread by
- caused by
- presents as

spread by tick feces and cattle placenta releasing spores that are inhaled
- caused by Coxiella burnetii
- presents as pneumo

77

Chlamydiae
- how to dx?
- cell wall does not have?

- cyto inclusions (contain lots of reticulate bodies) on Giemsa or fluorescent Ab-stained smear
- no muramic acid

78

Chlamydia trachomatis serotypes:
A,B,C =
D-K =
L1, L2, L3 =

- ABC=Africa/Blindness/Chronic infec (blind from follicular conjunctivitis)
- everything else! urethritis/PID, ectopic preg, neonatal pneumo (staccato cough) or conjunctivitis
- lymphogranuloma venereum

79

Mycoplasma pneumoniae
- high titer of?
- grown on?
- bac mem contains?
- trtmt?

cold agglutinins (IgM) which can agglutinate or lyse RBCs
- Eaton's agar
- sterols for stability
- macrolide or FQ

80

Enterobius, Ascaris, Trichinella
- are what?
- how do they infect?

nematodes
- ingested

81

Strongyloides, Ancylostoma, Necator
- are what?
- how do they infect?

nematodes
- thr skin

82

Brain cysts, seizures -> ? parasite

Taenia solium (cystericersosis) (pork tapeworm -> praziquentel)

83

Liver cysts -> ? parasite

Enchinococcus granulosus (dog tapeworm -> praziquantel; allergic to fluid in cysts)

84

VitB12 defic -> ? parasite

Diphyllobothrium latum (from raw freshwater fish -> praziquantel)

85

Biliary tract dz, cholangioca -> ? parasite

Clonorchis sinensis (from undercooked fish -> praziquantel)

86

Hemoptysis -> ? parasite

Paragonimus westermani (from undercooked crab meat -> lung inflamm and 2* bac infec -> praziquantel)

87

Portal HTN -> ? parasite

Schistosoma mansoni (from freshwater snails, eggs in liver/spleen -> fibrosis and inflamm -> praziquantel)

88

Hematuria, bladder ca -> ? parasite

Schistosoma haematobium (from freshwater snails -> lives in bladder -> eggs cause fibrosis and inflamm -> praziquantel)

89

Microcytic anemia -> ? parasite

Ancylostoma, Necator (hookworms, suck bl from GI wall -> anemia -> -bendazoles, pyrantel pamoate)

90

Perianal pruritus -> ? parasite

Enterobius (pinworm -> GI infec -> lay eggs at night outside anus -> Scotch tape test -> mebendazole or pyrantel pamoate)

91

Four vaccines for encap'd bugs?

pneumovax (PPV-23) has no conj'd pr, just polysacch (Strep.pneumo, >2yo at risk); Prevnar-13 is conj'd (kids d

92

JONES criteria for RF:

Jts (polyarthritis), Heart (carditis), Nodules (subcut), Erythema marginatum, Syndenham's chorea

93

Yersinia enterocolitica
- causes what 2 things?

day-care outbreaks of bl'y D
pseudoappendicities (actually is mesenteric adenitis)

94

Common causes of pneumo:
- in neonates?
- in kids 4wk - 18yrs

- GBS, E.coli
- Mycopl, Chlamydia trachomatis (infants-3yrs), C. pneumo (school kids), S. pneumo

95

Common causes of pneumo:
- 18-40yo
- 40-65yo
- elderly

- Mycopl, C.pneumo, S.pneumo
- S.pneumo, H.flue, anaerobes, viruses, mycopl
- S.pneumo, influenza virus, anaerobes, H.flue, GNRs

96

Pneumo in:
- nosocomial?
- CF?
- post-viral?

- Staph, enteric GNRs
- Pseudomonas, S.aureus, S.pneumo
- Staph, H.flue, S.pneumo

97

Common causes of meningitis:
- 0-6mo
- 6mo-6yrs
- 6-60yrs
- 60+ yrs

- GBS, E.coli, Listeria
- S.pneumo, N.meningitis, HiB (if unvaccinated), enteroviruses
- S.pneumo, N.meningitis (#1 in teens), enteroviruses, HSV
- S.pneumo, GNRs, Listeria

98

Trtmt of meningitis?

Ceftriaxone + vanc empirically, add amp if Listeria is suspected

99

Viral causes of meningitis?

Enteroviruses (esp. coxsackie), HSV-2 (HSV-1 = encephalitis), HIV, WNV, VZV

100

Causes of meningitis in HIV+?

Cryptococcus, CMV, toxoplasmosis (brain abscesses), JC virus (PML)

101

Chancroid =
- caused by?

painful genital ulcer, inguinal adenopathy
- Haemophilus ducreyi

102

Trichomonas vaginalis causes?
vs.
Gardnerella vaginalis causes?

- Vaginitis: strawberry-colored mucosa, motile in wet prep, STD
- Vaginosis: no inflamm, bad fishy smell d/c, pos whiff test, clue cells, not and STD

103

7 bugs that cause bl'y D?

Can't Stop Shitting E ErYthrocytEs:
Campylobacter
Salmonella
Shigella
EHEC
EIEC
Yersinia
Entamoeba

104

4 bac, 2 protozoa and 2 viruses that cause watery D?

ETEC, V.cholerae, C.dif, C.perfringens
Giardia, Cryptosporidium
Rotavirus, norovirus

105

Neutropenic pt's will get?

Candida albicans (systemic), Aspergillus