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Flashcards in Bacteria Deck (85):
1

gram positive cocci

staph, strep

2

gram negative cocci

neisseria

3

gram positive rods

clostridium, corynebacterium, bacillus, listeria, mycobacterium, gardnerella

4

branching filamentous gram positives

actinomyces, nocardia (weakly acid fast)

5

pleomorphic gram negatives

rickettsiae, chlamydiae

6

spiral gram negatives

spirochetes (borrelia, leptospira, treponema)

7

bacteria that do not gram stain well

These Microbes May Lack Real Color
- treponema, mycobacteria, mycoplasma, legionella (intracellular), rickettsia (intracellular parasite), chlamydia (intracellular parasite)

8

mycobacteria

contains mycolic acid, high lipid content

9

mycoplasma

no cell wall - contains sterols

10

Giemsa stain bugs

Certain Bugs Really Try my Patience
- chlamydia, borrelia, Rickettsia, Trypanosomes, Plasmodium

11

Ziehl-Neelsen

acid-fast organisms - nocardia, mycobacterium

12

PAS

tropheryma whipplei

13

india ink stain

cryptococus neoformans

14

silver stain

legionella, fungi (pneumocystis), H pylori

15

chocolate agar with factors V and X

H influenzae

16

Thayer Martin (VPN media)

neisseria
- Vancomycin, Polymixin/colistin, Nystatin

17

Bordet-Gengou (potato agar)

B. pertussis (Bordet for Bordetella)

18

tellurite agar, Loffler medium

C. diptheriae

19

Lowenstein-Jensen agar

M. tuberculosis

20

Eaton agar, requires cholesterol

M. pneumoniae

21

MacConkey agar

lactose-fermeting enterics
- e coli is also grown on eosin-methylene blue with green metallic sheen
- MacConKEE'S agar: citrobacter, klebsiella, e coli, enterobacter, serratia

22

charcoal yeast agar buffered with cysteine and iron

legionella

23

Sabouraud's agar

fungi

24

obligate aerobes

Nagging Pests Must Breathe
- nocardia, psuedomonas, MycoBacterium tuberculosis

25

facultative intracellular

Some Nasty Bugs May Live FacultativeLY
- salmonella, neiseeria, brucella, mycobacterium, listeria, francisella, legionella, yersinia pestis

26

obligate intracellular

rickettsia, chlamydia

27

obligate anaerobes

Anaerobes Can't Breathe Air
- clostridium, bacteroides, actinomyces
- lack catalase or superoxide dysmutase - susceptible to oxidative damage
-aminO2glycosides are effective because they require O2 to enter the cell

28

encapsulated organisms

SHiNE SKis
- strep pneumo, HiB, Neisseria meningitidis, E coli, Salmonella, Klebsiella pneumonia, group B Strep
(first three bugs secrete IgA protease to colonize respiratory mucosa)

29

catalase-positive organisms

You need PLACESS for your CATs
- chronic granulomatous disease have increased infections with these bugs because they lack NADPH oxidase
- pseudomonas, listeria, aspergillus, candida, E coli, S aureus, Serratia

30

urease positive bugs

PUNKSS Can Handle urease
- Proteus, Ureaplasma, Nocardia, Klebsiella, S epidermidis, S saprophyticus, Cryptococus, H pylori

31

diptheria toxin

- secreted by c. diphtheriae, inactivates elongation factor (EF-2)
- presents with pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck)

32

exotoxin A

- secreted by pseudomonas aeruginosa, inactivates elongation factor (EF-2)
- leads to host cell death

33

shiga toxin

- secreted by shigella spp. and inactivates 60s ribosome by removing adenine from rRNA
- GI mucosal damage --> dysentery
- ST also enhances cytokine release, causing HUS

34

shiga-like toxin

- secreted by EHEC and inactivates 60s ribosome by removing adenine from rRNA
- enhances cytokine release, causes HUS
- unlike shigella, does not invade host cells

35

heat-labile toxin (LT)

- secreted by ETEC, overactivates adenylyl cyclase, increased cAMP, increasing Cl secretion in gut
- watery diarrhea
- "Labile in the Air, Stable on the Ground"

36

heat-stable toxin (ST)

-secreted by ETEC, overactivates guanylate cyclase, increasing cGMP, decreasing NaCl and H20 absorption in the gut
- watery diarrhea, "Labile in the Air, Stable on the Ground"

37

edema factor

- secreted by bacillus anthracis
- mimics adenylate cyclase (inc cAMP), resulting in edema surrounding black eschar

38

cholera toxin

-secreted by vibrio cholerae, overactivates adenylate cyclase, inc cAMP, by permanently activating Gs --> Cl secretion into the gut
- voluminous "rice-water" diarrhea

39

pertussis toxin

- overactivates adenylate cyclase (inc cAMP) by disabling Gi, impairing phagocytosis to permit survival of microbe
- whooping cough, unknown if related to toxin

40

tetanospasmin

- produced by clostridium tetani, protease that cleaves SNARE proteins required for NT release
- spasticity, risus sardonicus, and "lockjaw"
- toxin prevents release of inhibitory NTs from Renshaw cells in spinal cord

41

botulinum toxin

- produced by clostridium botulinum, protease that cleaves SNARE proteins required for NT release
- flaccid paralysis, floppy baby, toxin prevents release of stimulatory Ach signals and NMJ

42

alpha toxin

-produced by clostridium perfringens, phospholipase (lechithinase) degrades tissue and cell membranes
- leads to myonecrosis ("gas gangrene") and hemolysis ("double zone" of hemolysis on blood agar)

43

streptolysin O

- produced by strep pyogenes, its a protein that degrades cell membranes
- lyses RBCs, contributes to b hemolysis, Abs used to diagnose rheumatic fever

44

toxic shock syndrome toxin (TSST-1)

- produced by staph aureus, brings MHC II and TCR in proximity to outside antigen binding site to cause overwhelming release of IFNgamma and IL 2 --> shock
- TSS, scalded skin syndrome, food poisoning

45

exotoxin A

- produced by strep pyogenes, brings MHC II and TCR in proximity to outside antigen binding site to cause overwhelming release of IFNgamma and IL 2 --> shock
- TSS

46

Endotoxin effects

ENDOTOXIN
- edema, NO, DIC, Outer membrane, TNFa, O-antigen, eXtremely heat stable, IL-1, Neutrophil chemotaxis

47

strep pneumo most common cause of...

MOPS
- meningitis, otitis media in kids, pneumonia, sinusitis
- Most are OPtochin Sensitivte

48

EIEC

invades intestinal mucosa and causes necrosis and inflammation. clinical manifestations similar to shigella

49

EHEC

- shiga-like toxin, HUS, does not ferment sorbitol like other e coli

50

EPEC

no toxin produced, adheres to apical surface and prevents absorption
- common in Pediatrics

51

ETEC

produces heat stable and heat labile enteroToxins
- watery travelers diarrhea

52

salmonella typhi

causes typhoid fever
- rose spots on the abdomen, fever, headache, diarrhea
- can remain in the gallbladder in carrier state

53

yersinia enterocolitica

transmitted via pet feces, contaminated milk, pork
- can mimic Chrons or appendicitis

54

H pylori

- catalase, oxidase and urease +
- creates an alkaline environment
- triple therapy: PPI + clarithromycin + amox or flagyl

55

VDRL false positives

viruses (mono, hepatitis), drugs, rheumatic fever, lupus/leprosy

56

reheated rice toxin

B. cereus

57

reheated meat dishes infection

C. perfringens

58

meats, mayo, custard preformed toxin

S. aureus

59

contaminated seafood infection

V. parahaemolyticus and V. vulnificus

60

campylobacter diarrhea

comma or S shaped organisms, growth at 42C

61

E histolytica diarrhea

protozoan, amebic dysentery, liver abscess

62

salmonella diarrhea

lactose neg, flagelar motility, has animal reservoir, esp poultry and eggs

63

Y enterocolitica diarrhea

day care outbreaks, pseudoappendicitis

64

causes of watery (non-bloody) diarrhea

C diff, C perfringens, ETEC, V. cholerae, rotavirus, norovirus, protozoa (giardia, cryptosporidium)

65

most common causes of pneumonia in neonates

E coli, GBS

66

most common causes of pneumonia in kids (4 weeks-18yrs)

Runts May Cough Chunky Sputum
- RSV, Mycoplasma, C. trachomatis, C. pneumoniae, Strep pneumo

67

most common causes of pneumonia in adults 18-40

Mycoplasma, C pneumoniae, S pneumoniae

68

most common causes of pneumonia in adults 40-65

S pneumo, H flu, anaerobes, viruses, mycoplasma

69

most common causes of pneumonia in the elderly

S pneumo, influenza, anaerobes, H flu, GNR

70

bugs causing pneumonia in alcoholic

s. pneumo, klebs, staph

71

bugs causing pneumo in CF

pseudomonas, s. aureus, s. pneumo

72

bugs causing pneumo in immunocompromised

staph, enteric GNR, fungi, viruses, PCP

73

bugs causing post-viral pneumonia

staph, H flu, s. pneumo

74

common causes of meningitis in 0-6mo

GBS, E coli, listeria

75

common causes of meningitis in 6 mo - 6 years

S. pneumo, N meningitidis, HiB, enteroviruses

76

common causes of meningitis 6 years - 60 years

s. pneumo, N. meningitidis, enteroviruses, HSV

77

common causes of meningitis 60+

S. pneumo, GNR, listeria

78

UTI bug with red pigment

serratia

79

UTI bug with "swarming" and associated with struvite stones

proteus

80

congenital toxo

chorioretinitis, hydrocephalus, intracranial calcifications

81

congenital rubella

PDA, cataracts, deafness +/- blueberry muffin rash

82

congenital CMV

hearing loss, seizures, petechial rash, "blueberry muffin" rash

83

congenital HIV

recurrent infections, chronic diarrhea

84

congenital HSV

encephalitis, herpetic vesicular lesions

85

congenital syphillis

stillbirth, hydrops, saddle nose, saber shins, CN VIII deafness, Hutchinson teeth