Lab Practical 2

Question 1

All GN Cocci

key characteristic

Answer 1

Neisseria gonorrhoeae
Neisseria meningitidis
Neisseria lactamica
Moraxella catarrhalis

kidney bean shaped

Question 2

All GN dipplococci and fastidious GN bacilli

Answer 2

Haemophilus influenzae
Haemophilus parainfluenzae
Brucella
Francisella tularensis
Legionella

Question 3

All Enterobacterales

Answer 3

Citrobacter freundii
Enterbacter cloacae
Escherichia coli
Klebsiella pnemoniae
Proteus mirabilus
Vibrio
Shigella
Salmonella
E. coli O157

Question 4

All Remaining MISC GNR

Answer 4

Acinetobacter baumannii (ACBA)
Burkholderia cepacia (BUCE)
Stenotrophomonas maltophilia (STMA)
Pseudomonas aeruginosa (PSAE)
Yersinia

Question 5

MAC Agar

type, additives, growth indicators

Answer 5

Slective differential
Selective: bile salt + crystal violet, selects for G-
Differential: lactose fermentation > turns agar pink
Growth: enterobacterales mostly

Question 6

All Mediums for Neisseria

3 type, reagents

Answer 6

Thayer Martin, Modified Thayer Martin, Martin Lewis

All are modified CHOC with vancomycin

Question 7

What Agar is Used to Isolate Bordatella?

2 name, type, reagents

Answer 7

Bordet-gengou (B-G) blood agar
- Enriched + selective
- Blood and glycerol for enrichment, antimicrobials for selectivity
- For B. pertussis and parapertussis

Regan-Lowe agar
- B. pertussis
- Charcoal

Question 8

Legionella Isolating Medium

Name, type, how

Answer 8

BCYE-alpha (buffered charcoal-yeast extract) Agar
- Enriched
- L-cysteine added which Legionella needs
- Charcoal absorbes toxic compounds

Question 9

SMAC Agar

type, how, what for

Answer 9

Selective differential
- Sorbitol replaces lactose
- Normal E. coli flora can ferment sorbitol, E coli. O157 is colorless

Question 10

HE Agar

what species, reagents,

Answer 10

Salmonella and Shigella
- Lactose, sucrose, bile salt, ferric ammonium sulfate for H2S
- Salmonella produces H2S, Shigella does not

Question 11

CIN Agar

2 species, reagent

Answer 11

Isolation of Yersinia, sometimes Citrobacter can grow
- Yersinia appears translucent without dark red centers
- Novobiocin antimicrobial

Question 12

Medium for Vibrio Isolation

Answer 12

Thiosulfate Citrate Bile salts Sucrose (TCBS) agar
- Thiosulfate
- oxgall
- sucrose use = yellow color

Question 13

Neisseria + Moraxella Lactose

Answer 13

Neisseria gonorrhoea: -
Neisseria lactamica: +
Moraxella: -
Neisseria meningitidis: -

Question 14

Neisseria + Moraxella Glucose

Answer 14

All Neisserias can use
Moraxella cannot use

Question 15

Neisseria + Moraxella Maltose

Answer 15

Lactamica and meningitidis can
Gonorrhoea and Moraxella cannot

Question 16

Butyrate test

method and who is +

Answer 16

Production of butyrate esterase causes release in indoxyl. Forms indigo, blue green color change
Only Moraxella catarrhalis is +

Question 17

Oxidase

method

Answer 17

Kovac reagent oxidized by electrons, makes purple color

Question 18

Porphyrin

method, what for, results

Answer 18

Porphobilinogen presence, ALA will convert to porphyrin, fluorescent

• Separate H. influenzae and parainfluenzae
• Tests for hemin

+: parainfluenzae
-: influenzae

Question 19

Satellite Growth

Answer 19

H. influenzae needs both NAD (V) and hemin (X) that it will grow around S. aureus bc it lyses the blood and releases V factor

Question 20

Oxidation Fermentation (O/F)

how, what species and results

Answer 20

How: sugar and pH indicator, oil layer for anaerobic
Fermenter: E. coli
Oxidizer: Pseudomonas aeruginosa

Question 21

Pigment Production of Pseudomonas Aeruginosa

Answer 21

blue and fluorescent coloring

Question 22

Spot Indole

reagents, interpretation

Answer 22

Trypyophanase enzyme detection, degrade indole because of degradation of tryptophan
- Red color +

Separate E. coli from other enterbacterales becaue E.coli is +

Question 23

ONPG Test

method, results

Answer 23

B- galactosidase cleaves ONPG into galactose
- Positive if broth turns yellow
E.coli is + while Proteus mirabilis is -

Question 24

MUG test

method, results

Answer 24

Tests for beta glucuronidase, fluorescence
Only E. coli is +

Question 25

TSI Test ## Footnote method, results

Answer 25

Glucose, sucrose, lactose, ferric and sodium thiosulfate **A/A:** glucose + something else **K/A:** only glucose **K/K:** none of the sugars **H2S:** has to be either A/A or K/A because enterbacterales always uses glucose, only ones that can produce H2S

Question 26

Motility Test

Answer 26

**Nonmotile enterobacterales:** Klebsiella pnuemoniae and Shigella **Nonmotile Misc GNR:** acinetobacter baumannii

Question 27

Citrate Agar

Answer 27

Can utilize citrate, slant turns blue **Klebsiella pneumoniae + E. colli -**

Question 28

Good Test to Differentiate Proteus Mirabilis ## Footnote But also what?

Answer 28

Urea hydrolysis - CIFR, ENCL, and KLPN and also split urea into ammonia

Question 29

MR/VP ## Footnote 2 reagents in VP, enterobacterales

Answer 29

**VP:** *KOH and alpha-naphthol* **Positive for VP:** ENCL and KLPN - Everything else negative - **Vice versa for MR:** ENCL and KLPN are negative for MR while everything else +

Question 30

Nitrate Reduction ## Footnote what kinds of reduction? 2 reagents in broth

Answer 30

All enterobacterales can reduce nitrate - Can go directly to N2 gas or - **alpha napthylamine and sulfanilic acid for reduction to nitrite** - Turns red if nitrite - If colorness, add zinc and red color means there is still nitrate, no color means N2 produced and no nitrate left

Question 31

Yersinia Bench Aid

Answer 31

- Catalase + - Nonmotile at 25 and 35/37 - Urease, Oxidase, Indole - - Bipolar staining safety pin appearance -

Question 32

Burkholderia Bench Aid

Answer 32

**B. mallei:** oxidase -, non motile **B. pseudomallei:** opposite of that

Question 33

Francisella Bench Aid

Answer 33

- No SBA growth - Oxidase, urease - - Catalase weak +

Question 34

Brucella Bench Aid

Answer 34

SBA and CHOC - Oxidase, urease + - Non motile

Question 35

Oxidase + Rods ## Footnote 2, differentiate

Answer 35

Burkholderia cepecia Pseudomonas aerogunosa - Then do colony morph, pseudomonas smell and sheen

Question 36

Nonmotile Rods ## Footnote 3, differentiate

Answer 36

Klebsiella pneumoniae Shigella Acinetobacter baumannii - MAC lactose, ACBA is non fermenter

Question 37

Motile Rods ## Footnote 5, how to differentiate

Answer 37

ESCO ENCL STMA PRMI CIFR - Then do tsi h2s production

Question 38

TSI H2S Production in Rods

Answer 38

**+ :** PRMI, CIFR **- :** ENCL, ESCO, STMA

Question 39

Differentiate ESCO and ENCL

Answer 39

Indole - E. coli is + - Enterobacter cloacae is -

Question 40

Differentiate CIFR and PRMI

Answer 40

Proteus mirabilis swarms on SBA, Citrobacter does not