Bacteriology Basics

Question 1

PAS Stain

Answer 1

Stains Glycogen

Used to diagnose Whipple disease

Question 2

Ziehl-Neelsen (carbol fuchsin) Stain

Answer 2

Stains Acid-fast organisms (Nocardia, mycobacterium)

Question 3

India Ink

Answer 3

Stains Cryptococcus neoformans

Question 4

Silver Stain

Answer 4

Fungi
Legionella
H. pylori

Question 5

Thayer-Martin Media (VPN)

Answer 5

Contains Vancomycin (inhibits gram +), Polymyxin (inhibits gram -s except Neisseria), and Nystatin (inhibits fungi)
Used for Neisseria species

Question 6

MacConkey Agar

Answer 6

Lactose fermenters grow pink colonies

Question 7

Obligate Aerobes

Answer 7

Nocardia
Pseudomonas aeruginosa
Mycobacterium tuberculosis
Bacillus (?)

Question 8

Obligate Anaerobes (lack catalase and/or superoxide dismutase)

Answer 8

Clostridium
Bacterioides
Actinomyces

Question 9

Obligate Intracellular Bacteria (Can’t Make own ATP)

Answer 9

Rickettsia

Chlamydia

Question 10

Encapsulated Bacteria

Answer 10

SHiNE SKiS:
Streptococcus pneumoniae
Haemophilus influenzae B
Neisseria meningitidis
E. Coli
Salmonella
Klebsiella pneumoniae
Group B Strep

Question 11

Catalase + (degrades H2O2 before it can be converted to microbicidal products by MPO)

Answer 11

If you have chronic granulomatous disease (NADPH oxidase deficiency), you have recurrent infections with cat+ organisms:
Staph
Psuedomonas
Listeria
Aspergillus
E. coli
Serratia
Candida

Question 12

Urease-Positive Bugs

Answer 12

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

Question 13

Pigment-Producing Bacteria

Answer 13

Actinomyces israelii: yellow “sulfur” granules
S. aureus: yellow pigment
Pseudomonas aeruginosa: blue-green pigment
Serratia marcescens: red pigment (maraschino cherries)

Question 14

Protein A

Answer 14

Expressed by S. aureus

Binds Fc region of IgG and prevents opsonization and phagocytosis

Question 15

IgA Protease

Answer 15

Secreted by Strep pneumoniae, H influenzae B, and Neisseria (SHiN) in order to colonize respiratory mucosa
It’s an enzyme that cleaves IgA

Question 16

M Protein

Answer 16

Expressed by Strep Pyogenes
Helps prevent phagocytosis
Molecular mimicry in rheumatic fever

Question 17

Endotoxin Clinical Effects and Mode of Action

Answer 17

Fever, Shock, DIC

Does this by inducing TNF, IL-1, and IL-6

Question 18

Transformation

Answer 18

Ability to take up naked DNA from environment (a feature of many bacteria including SHiN)

Question 19

Conjugation

Answer 19

Transfer of genetic material between two bacteria by a bridge or by direct cell to cell contact

Question 20

Transposition

Answer 20

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

Question 21

Transduction

Answer 21

Genetic material is transferred from a bacteria to another bacteria by a virus

Question 22

Alpha Hemolytic Bacteria Appearance on Blood Agar

Answer 22

Green ring around colonies