Microbiology

Question 1

Giemsa stain

“Certain Bugs Really Try my Patience”

Answer 1

Chlamydia
Borrelia
Rickettsiae
Trypanosomes
Plasmodium

Question 2

PAS (periodic acid-Schiff) stain

Answer 2

Tropheryma whipplei

Stains glycogen, mucopolysaccharides

Question 3

Ziehl-Neelsen (carbol fuschin) stain

Answer 3

Acid fast organisms
Mycobacterium
Nocardia

Question 4

India ink stain

Answer 4

Cryptococcus neoformans

Question 5

Mucicarmine stain

Answer 5

Cryptococcus neoformans

Stains the thick polysaccharide capsule red

Question 6

Silver stain

Answer 6

Fungi = pneumocystis
Legionella
Helicobacter pylori

Question 7

Chocolate agar with factors V (NAD+) and X (hematin)

Answer 7

Haemophilus influenzae

Question 8

Thayer-Martin (VPN) media

Answer 8

Neisseria gonorrhoeae

Neisseria meningitidis

Question 9

VPN media components

Answer 9

Vancomycin (gram +)
Polymyxin (gram -)
Nystatin (fungi)

Question 10

Bordet-Gengou (potato) agar

Answer 10

Bordetella pertussis

Question 11

Tellurite agar, Loffler media

Answer 11

Corynebacterium diphtheriae

Question 12

Lowenstein-Jensen agar

Answer 12

Mycobacterium tuberculosis

Question 13

Eaton agar, requires cholesterol

Answer 13

Mycoplasma pneumoniae

Question 14

Pink colonies on MacConkey agar

Answer 14

Lactose fermenting enterics
Fast = Klebsiella, E.coli, Enterobacter (Fast is KEE)
Slow = Citrobacter, Serratia

Question 15

Green metallic sheen on eosin-methylene blue (EMB) agar

Answer 15

Escherichia coli

Question 16

Charcoal yeast extract agar buffered with cysteine and iron

Answer 16

Legionella

Question 17

Sabouraud agar

Answer 17

Fungi

Question 18

Obligate aerobes

“Nagging Pests Must Breathe”

Answer 18

Nocardia
Pseudomonas aeruginosa
Mycobacterium tuberculosis

Question 19

Pseudomonas infection associations (4)

Answer 19

Burn wounds
Complications of diabetes
Nosocomial pneumonia
Pneumonias in cystic fibrosis

Question 20

Obligate anaerobes

“Anaerobes Can’t Breathe Air”

Answer 20

Clostridium
Bacteroides
Actinomyces
Lack catalase and/or superoxide dismutase = susceptible to oxidative damage
Produce GAS in tissue (CO2 and H2)

Question 21

Which class of antibiotic is ineffective against anaerobes?

Answer 21

Aminoglycosides

Require O2 to enter into bacterial cell

Question 22

Obligate intracellular

“Stay inside when it’s Really Cold”

Answer 22

Rickettsia
Chlamydia
Cannot make own ATP

Question 23

Facultative intracellular

“Some Nasty Bugs May Live FacultativeLY”

Answer 23

Salmonella
Neisseria
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersinia pestis

Question 24

Encapsulated bacteria

“SHiNE SKiS”

Answer 24

Streptococcus pneumoniae
Haemophilus influenzae type B
Neisseria meningitidis
Escherichia coli
Salmonella
Klebsiella pneumoniae
Group B Strep (S. agalactiae)

Opsonized and cleared by spleen
Asplenics have decreased opsonizing ability and are at risk for severe infections

Question 25

Which vaccines should you give to asplenic patients?

Answer 25

S. pneumoniae H. influenzae N. meningitidis Capsule + protein conjugate = antigen in vaccines

Question 26

Catalase positive organisms | "PLACESS for your cats"

Answer 26

``` Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia ```

Question 27

Urease positive organisms

Answer 27

``` Cryptococcus Helicobacter pylori Proteus Ureaplasma Nocardia Klebsiella Staphylococcus epidermidis Staphylococcus saprophyticus ```

Question 28

Pigment producing bacteria

Answer 28

Actinomyces israelii = yellow "sulfur" granules, composed of filaments of bacteria S. aureus = yellow pigment (aureus = gold) Pseudonomas aeruginosa = blue green pigment Serratia marcescens = red pigment

Question 29

Protein A

Answer 29

Binds Fc region of IgG = prevents opsonization and phagocytosis Expressed by S. aureus

Question 30

IgA protease

Answer 30

Enzyme that cleaves IgA | Secreted by S. pneumoniae, H. influenzae type B, and Neisseria (SHiN) in order to colonize respiratory mucosa

Question 31

M protein

Answer 31

Helps prevent phagocytosis | Expressed by group A streptococci