Bacteria

Question 1

Don’t Gram Stain Well:

Answer 1

These Microbes May Lack Real Color
Treponema, Mycobacteria, Mycoplasma, Legionella, Rickettsia, Chlamydia

plus: Leptospira, Bartonella, Ehrlichia, Anaplasma

Question 2

Reason for poor gram stain = too thin to be visualized

Answer 2

Treponema, Leptospira

Question 3

Reason for poor gram stain = cell wall has high lipid content

Answer 3

Mycobacteria

Question 4

Reason for poor gram stain = no cell wall

Answer 4

Mycoplasma, ureaplasma

Question 5

Reason for poor gram stain = primarily intracellular

Answer 5

Legionella, Rickettsia, Chlamydia, Barontella, Ehrlichia, Anaplasma

Chlamydia also lack classic peptidoglycan bc of decreased muramic acid

Question 6

Giemsa Stain

Answer 6

Chlamydia, Rickettsia, Borrelia, Trypanosomes, Plasmodium

Question 7

PAS stain dyes which molecules?

Answer 7

glycogen, mucopolysaccharides (PaSs the sugar)

Question 8

PAS stain Dx’es

Answer 8

Whipple Dz (tropheryma whipplei)

Question 9

Ziehl-Neesen Stain

Answer 9

Acid fast bacteria
Mycobacteria (mycolic acid)
Nocardia
Protozoa like Cryptosporidium oocysts

Question 10

Ziehl-Neesen stain alternative for screening

Answer 10

Auramine-rhodamine stain

Question 11

India ink stain

Answer 11

Encapsulated Fungus - Cryptococcus neoformans

Mucicarmine also stains its thick polysaccharide capsule red.

Question 12

Sliver Stain

Answer 12

Fungi - Coccidioides, PCP
Legionella
Helicobacter pylori

Question 13

Syphilis fluorescent Ab stain for confirmation (specific)

Answer 13

FTA-ABS

Question 14

Thayer Martin agar is selective for:

Answer 14

Neisseria

Vanco - gram +
Trimethoprim and Colistin - gram - except Neisseria
Nystatin - fungi

Question 15

MacConkey Agar detects

Answer 15

pH: lactose fermenters = pink (ex: E. coli)

Question 16

H influenza grows on

Answer 16

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

Question 17

B pertussis grows on

Answer 17

Bordet-Gengou agar (potato)

Regan-Lowe medium (charcoal, blood, antibiotic)

Question 18

C. diphtheriae grows on

Answer 18

Tellurite agar

Loffler medium

Question 19

M tuberculosis grows on

Answer 19

Lowenstein-Jensen agar

Question 20

M pneumonia grows on

Answer 20

Eaton agar - requires cholesterol

Question 21

E coli grows on (besides MacConkey):

Answer 21

Eosin-methylene blue (EMB) agar

Colonies w/ green metallic sheen

Question 22

Legionella grows on

Answer 22

Charcoal yeast extract agar + cysteine and iron

Question 23

Fungi grow on

Answer 23

Sabouraud agar

“Sab’s a fun guy!)

Question 24

Obligate Aerobes

Answer 24

Nagging Pests Must Breathe
Nocardia
Pseudomonas
Mycobacterium TB (loves the apexes when reactivated)
Bacillus

Question 25

Obligate Anaerobes

Answer 25

Can't Breath Fresh Air - no catalase or superoxide dismutase Clostridium Bacteroides Fusobacterium Actinomyces Generally foul-smelling and produce gas in tissue (CO2/H2O) AminOglycosides are ineffective (need O2 to activate drug) - Tx w/Metronidazole and Clindamycin

Question 26

Obligate Intracellular

Answer 26

Rickettsia, Chlamydia, Coxiella "Really CHillly and COld - stay inside" Rely on host ATP

Question 27

Facultative Intracellular

Answer 27

``` Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersenia pestis ```

Question 28

Encapsulated Bacteria

Answer 28

``` Even Some Pretty Nasty Killers Have Shiny Bodies E. coli S. pneumonia Pseudomonas N. meningitides Klebsiella Haemophilus influenzae B Salmonella B Strep (agalactiae) All opsonized/cleared by spleen ```

Question 29

Encapsulated Bacteria w/ Vaccines

Answer 29

``` SHiN S. pneumoniae Haemophilus influenza B N. meningiditis For asplenics especially! ```

Question 30

Encapsulated Vaccine components

Answer 30

Capsular polysaccharide + protein conjugate = antigen PCV (conjugated - Prevnar), HiB and Meningiococcal are all conjugated PPSV (polysaccharide) is not conjugated to a protein (pneumovax)

Question 31

Urease Positive organisms

Answer 31

``` Pee CHUNKSS Proteus Cryptococcus H pylori Ureaplasma Nocardia Klebsiella S epidermidis and S saprophyticus Potentiate struvite stones (hydrolyzes urea to release ammonia + CO2 which increases pH) ```

Question 32

Catalase Positive Organisms

Answer 32

``` Cats Need PLACESS to Belch Hairballs Nocardia Pseudomonas Listeria Aspergillus Candida E coli Staphylococci Serratia B cepacia H pylori ```

Question 33

Yellow "sulfur" granule pigment

Answer 33

Actinomyces israelii Israel has yellow sand Granules - filaments of bacteria surrounded by neutrophils

Question 34

Yellow pigment

Answer 34

S aureus (gold)

Question 35

Blue-green pigment

Answer 35

Pseudomonas aeruginosa

Question 36

Red pigment

Answer 36

Serratia marcescens (Maraschino cherry!)

Question 37

Form biofilms

Answer 37

S epidermidis Strep viridans Pseudomonas Nontypeable H influenza

Question 38

Biofilm on catheter and prosthetic devices

Answer 38

S epidermidis

Question 39

Biofilm on dental plaques

Answer 39

Biofilm on endocarditis too | Strep viridans

Question 40

Biofilm on respiratory tree or contact lens

Answer 40

Pseudomonas

Question 41

Biofilm on otitis media

Answer 41

Nontypeable (unencapsulated) H influenza

Question 42

Protein A virulence factor

Answer 42

S aureus binds Fc of IgG prevents opsonization/phagocytosis

Question 43

IgA protease

Answer 43

``` SHiN S. pneumoniae H. influenza B Neisseria Helps to colonize respiratory tract! These SHiN bacteria can also do transformation (take up environmental DNA = "competence") ```

Question 44

Type III Secretion System

Answer 44

"Injectosome" - direct delivery of toxins from gram - bacteria Pseudomonas, Salmonella, Shigella, E coli

Question 45

Spore Forming Bacteria

Answer 45

Bacillus Clostridium Coxiella (Q-fever)

Question 46

Lysogenic Phage Toxins

Answer 46

``` ABCD'S Group A strep erythrogenic toxin Botulinum toxin Cholera toxin Diphtheria toxin Shiga toxin ```