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Flashcards in Random Micro Things that are annoying Deck (68):
1

Media used for H. influenzae culture

Chocolate agar
-Requires Factors V (NAD) and X (Hematin)

2

Media used for N. gonorrhoeae and N. meningitidis culture

Thayer-Martin agar (VCN)
-Vancomycin: inhibits gram pos organisms
-Colistin: inhibits gram neg except Neisseria
-Nystatin: inhibits fungi

3

Media used for B. pertussis culture

Bordet-Gengou agar (Bordet for Bordetella)
Regan-Lowe medium (contains charcoal, blood, Abx)

4

Media used for C. diptheriae culture

Cystine-Tellurite agar
Loffler medium

5

Media used for M. tuberculosis culture

Lowenstein-Jensen agar

6

Media used for M. pneumoniae culture

Eaton agar (requires cholesterol)

7

Media used for Lactose-fermenting enterics culture)

MacConkey agar (colonies turn pink)

8

Media used for E. coli culture

Eosin-methylene blue (EMB) agar

9

Media used for Legionella culture

Charcoal yeast extract agar buffered with cysteine and iron

10

Media used for Fungi culture

Sabouraud agar (Sab's a fun guy)

11

Spirochetes

Borrelia
Leptospira
Treponema

12

No cell wall

Mycoplasma
Ureaplasma

13

Pleomorphic

Chlamydiae
Rickettsiae

14

Which bugs don't gram stain well and why?

Treponema - too thin to be seen
Mycobacteria - high lipid content; mycelia acids in cell wall detected by carbolfuchsin in acid fast stan
Mycoplasma - no cell wall
Legionella - primarily intracellular
Rickettsia - intracellular parasite
Chalmydia - intracellular parasite; lacks classic peptidoglycan because of low muramic acid

15

Silver stain

Legionella, Fungi (pneumocystis), Helicobacter pylori

16

India ink

Cryptococcus neoformans

17

Ziehl-Neelsen (carbol fuchsin) stain

Acid-fast bacteria (Nocardia, Mycobacteria)
Protozoa (Cryptosporidium oocysts)

18

Alternative to Ziehl-Neelsen stain

Auramine-Rhodamine stain

19

PAS (periodic acid Schiff stain)

Stains glycogen, mucopolysaccharides, used to diagnose Whipple disease (Tropheryma whipplei)

20

Giemsa stain (Certain Bugs Really Try my Patience)

Chlamydia
Borrelia
Rickettsia
Trypanosomes
Plasmodium

21

Which bacteria has the following?
a. Antiphagocytic capsule
b. Hypervariable pili
c. IgG binding outer membrane protein
d. Intracellular polyphosphate granules

a. Strep pneumo, H. influenzae, Neisseria
b. Neisseria meningitidis AND gonorrhea
c. Staph aureus (Protein A)
d. Corynebacterium diptheriae (evident with methylene blue stain)

22

Obligate Aerobes (Naggy Pests Must Breathe)

Nocardia
Pseudomonas
MycoBacterium tb (predilection for apices of lung which have highest pO2)

23

Obligate Anaerobes (Frankly Can't Breathe Air)

Fusobacterium
Clostridium
Bacteroides
Actinomyces

24

Properties of Anaerobes

Lack catalase and/or superoxide disputes so they are susceptible to oxidative damage
-Generally foul smelling (short chain fatty acids) and difficult to culture
-Produce gas in tissue (CO2 and H2)

25

Which antibiotic is ineffective against anaerobes? Why?

AminOglycOsides --> they require O2 to enter into bacterial cell

26

Obligate intracellular bugs (stay inside, it's Really CHilly COld)

Rickettsia
Chalmydia
Coxiella
-ALL rely on host ATP

27

Facultative intracellular bugs

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

28

Encapsulated bacteria (SHiNE SKiS) + P

Strep pneumo
H. influenzae
Neisseria
E. coli
Salmonella
Klebsiella
Group B strep
AND PSEUDOMONAS

29

How are encapsulated bacteria cleared?

Opsonized and cleared by spleen

30

Which bacteria have conjugate vaccines?

PCV (pneumococcal conjugate)
H influenzae type B
Meningococcal

31

Urease positive (CHubby PUNKSS)

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

32

Catalase positive organisms (Cats Need PLACESS)

Nocardia
Pseudomonas
Listeria
Aspergillus
Candida
E. coli
Staphylococci
Serratia

33

Abscesses commonly caused by?

Catalase + organisms

34

Bacteria that produce yellow sulfur granules

Actinomyces

35

Bacteria with yellow pigment

Staph aureus

36

Bacteria with blue green pigment

Pseudomonas

37

Bacteria with red pigment

Serratia marcescens

38

Which organisms have IgA protease and what does it do?

Strep pneumo, H influenzae and Neisseria --> cleaves IgA so that they can colonize respiratory mucosa

39

Which bacteria have type III secretion system?

Pseudomonas
Salmonella
Shigella
E. coli

40

Toxin produced by bacteria and released

Exotoxin (gram + and -)

41

Location of exotoxin genes

Plasmid or bacteriophage

42

Are exotoxins and endotoxins heat stable?

Exotoxin - destroyed rapidly at 60 degrees celsius (except staph enterotoxin)
Endotoxin - stable at 100 degrees celsius for 1 hour

43

Corynebacterium diphtheria toxin

Exotoxin that inactivates elongation factor 2 --> pharyngitis with pseudomembranes in throat and severe lymphadenopathy (bull neck)
-Similar to Pseudomonas toxin

44

Pseudomonas aeruginosa toxin

Exotoxin A --> inactivates EF2 --> host cell death
-Similar to C. diphtheria toxin

45

Shigella toxin

Shiga toxin --> inactivates 60s ribosome by removing adenine from rRNA--> inhibits protein synthesis --> GI mucosal damage causes dysentery and ST also enhances cytokine release causing HUS

46

E. coli (EHEC) toxin

Shiga-like toxin (SLT) --> inactivates 60s ribosome by removing adenine from rRNA --> stops protein synthesis --> enhances cytokine release causing HUS (DOES NOT INVADE HOST CELLS LIKE SHIGELLA)

47

E. coli (ETEC) toxin

1. Heat labile (LT) --> overactivates adenylate cyclase to increase cAMP --> increase Cl secretion in gut and water efflux
2. Heat stable (ST) --> overactivates guanylate cyclase to increase cGMP --> decrease resorption of NaCl and H20 in gut

48

Bacillus anthracis toxin

Edema toxin --> mimics adenylate cyclase enzyme to increase cAMP and causes edematous borders of black eschar in cutaneous anthrax

49

Vibrio cholerae toxin

Cholera toxin --> overactivates adenylate cyclase to increase cAMP by permanently activating Gs --> increases Cl secretion in gut and water efflux --> rice water diarrhea

50

Bordetella pertussis toxin

Overactivates adenylate cyclase (increases cAMP) by disabling Gi --> impairing phagocytosis to permit survival of microbe --> whooping cough

51

Clostridium tetani toxin

Tetanospasmin --> protease that cleaves SNARE --> prevents release of inhibitory (GABA and glycine) neurotransmitters from Renshaw cells in spinal cord

52

Clostridium botulinum toxin

--> protease the cleaves SNARE to prevent release of stimulatory Ach signals at neuromuscular junction --> flaccid paralysis

53

Clostridium perfringens toxin

Alpha toxin --> phospholipase (lecithinase) that degrades tissue and cell membranes --> degradation of phospholipids --> myonecrosis and hemolysis

54

Streptococcus pyogenes toxin

Streptolysin O -->protein that degrades cell membrane --> lyses RBCs (host antibodies against toxin can be used to diagnose acute rheumatic fever)

55

Staph aureus toxin

Toxic shock syndrome toxin (TSST1) --> binds to MHCII and TCR outside of antigen binding site to cause overwhelming release of IL1, IL2, IFNy and TNFalpha --> shock

56

Strep pyogenes toxin

Exotoxin A --> binds to MHC II and TCR outside of antigen binding site to cause overwhelming release of IL1, IL2, IFNy and TNFalpha --> shock

57

Actions of endotoxin (esp Lipid A)

Edema (C3a)
Nitric oxide (hypotension)
DIC/Death (activates tissue factor)
Outer membrane
TNF-alpha (fever and hypotension)
O-antigen
eXtremely heat stable
IL-1 (fever)
Neutrophil chemotaxis (C5a)

58

What is transformation?

Ability to take up NAKED DNA from environment (also known as competence)

59

Which bacteria can undergo transformation?

Strep pneumo
H. influenzae type B
Neisseria

60

How does adding deoxyribonuclease to environment affect transformation?

Deoxyribonucleases degrade DNA and there is no transformation

61

What are F+ bacteria?

F+ plasmid contains genes required for sex pilus and conjugation

62

What are F- bacteria?

Bacteria without the plasmid (conjugation)

63

What is F+ x F- conjugation?

The sex pilus on the F+ bacterium contacts the F- bacterium and a single strand of plasmid DNA is transferred across the conjugal bridge
NO TRANSFER OF CHROMOSOMAL DNA

64

What is Hfr x F- conjugation?

F+ plasmid can become incorporated into bacterial chromosome (high frequency recombination = Hfr) --> replication of incorporated plasmid DNA may include some flanking chromosomal DNA so there is transfer of plasmid AND chromosomal DNA (unlike F+ x F-)

65

What is transposition?

Segment of DNA (transposon) that can jump from one location to another and transfer genes from plasmid to chromosome and vice versa

66

What is generalized transduction?

A packaging event --> a lytic phage (virus) infects bacterium leading to cleavage of bacterial DNA --> parts of the bacterial chromosomal DNA may become packaged in viral capsid --> phage infects another bacterium and transfers these genes

67

What is specialized transduction?

Excision event where lysogenic phage infects bacterium and viral DNA incorporates into bacterial chromosome --> when phage DNA is excised the flanking bacterial genes may be excised with it --> the DNA is packaged into phage viral capsid and can infect another bacterium

68

Which bacterial toxin genes are encoded as lysogenic phage? (ABCDE)

shiga A like toxin
Botulinum toxin
Cholera toxin
Diptheria toxin
Erythrogenic toxin of Streptococcus pyogenes