Unit 2 Neisseria, Moraxilla, and Haemophilus

Question 1

Gram stain: Neisseria

Answer 1

Gram negative Diplococci

Question 2

Gram stain: Haemophilus

Answer 2

Gram negative Pleomorphic coccobacilli or rods

Question 3

Gram stain: Moraxella catarrhalis

Answer 3

Gram negative Diplococci

Question 4

Discuss the correct method of collection and transport necessary to recover Neisseria gonorrhoeae.

Answer 4

Collection: Non-nutritive swab- Dacron or Rayon; cotton and calcium alginate swabs are prohibited

Transport: “Bedside” inoculation to transport systems

Culture: Selective media that inhibits normal flora (jembec) and CO2 atmosphere

Question 5

Choose the appropriate primary isolation media to recover Neisseria and Haemophilus species based on knowledge of content and purpose of the media.

Answer 5

Neisseria: Jembec and CO2 atmosphere; **Modified Thayer Martin, chocolate agar with IsoVitaleX suuplement

Haemophilus: Chocolate agar with 33-37°C, 5-10% CO2

Question 6

Colony morphology: Neisseria gonorrhoeae

Answer 6

small, round translucent ON CHOC: tan ON BLOOD: doesn’t grow well

Question 7

Colony morphology: Neisseria meningitidis

Answer 7

gray, convex, possibly mucoid ON CHOC: possibly greenish hue

Question 8

Colony morphology: Neisseria lactamica

Answer 8

yellow/gold colonies

Question 9

Colony morphology: Moraxella catarrhalis

Answer 9

smooth, opaque, gray/white colonies; “hockey puck”

Question 10

Colony morphology: Haemophilus influenzae

Answer 10

Translucent, tan, sometimes mucoid with distinct mousy odor

Question 11

Colony morphology: Haemophilus influenzae biogroup aegyptus

Answer 11

Same as H. influenzae but smaller colonies

Question 12

Colony morphology: Haemophilus ducreyi

Answer 12

small, flat, smooth, translucent/opaque, “scooty”

Question 13

Explain the principle and purpose: Nitrate reduction

Answer 13

1) Determine if the organism can reduce nitrate

2) Nitrate is used at the final electron acceptor for anaerobic metabolism by a lot of GNs

Question 14

Explain the principle and purpose: Carbohydrate utilization test

Answer 14

1) Determine which carbohydrates can be utilized for growth

2) Growth/use of carbohydrate results in color change due to pH change

Question 15

Explain the principle and purpose: Porphyrin test (ALA)

Answer 15

1) For respiratory sources, tests presence of enzymes that make porphyrin
2) ALAporphyrinX factor
Synthesize own hemin=X factor independent=pink fluorescence under UV

Question 16

Explain the principle and purpose: Catarrhalis disk

Answer 16

1) Detection of butyrate esterate

2) Hydrolysis of substrate releases indoxyl blue/green color

Question 17

Explain the principle and purpose: DNase test

Answer 17

1) Determine if the organism has the enzyme DNase/can hydrolyze DNA
2) DNase in the organism will break down  colorless zone

Question 18

Explain the principle and purpose: Beta lactamase

Answer 18

1) Determine if the organism produces beta-lactamases

2) Beta lactames open beta lactam ringscolor change (pink)

Question 19

Explain the principle and purpose: Haemophilus ID quad

Answer 19

1) Speciation

2) Growth factors V + X, horse or rabbit blood to assess hemolysis

Question 20

Explain the principle and purpose: Staph streak

Answer 20

1) Determine V factor requirement

2) Haemophilus species that require V factor satellite around Staph on blood agar bc its produces V factor

Question 21

Differentiate the saprophytic Neisseria from potentially pathogenic Neisseria species utilizing colony morphology characteristics.

Answer 21

Nonpathogenic typically yellow/gold colonies; except Neisseria lactamica, nonpathogenic cannot grown on MTM

Question 22

Haemophilus influenzae: growth factor requirements, ALA and hemolysis

Answer 22

1) X and V
2) Negative
3) None

Question 23

Haemophilus influenzae biogroup aegyptius: growth factor requirements, ALA and hemolysis

Answer 23

1) X and V
2) Negative
3) Positive on RB

Question 24

Haemophilus parainfluenzae: growth factor requirements, ALA and hemolysis

Answer 24

1) V only
2) Positive
3) Variable on RB

Question 25

Haemophilus haemolyticus: growth factor requirements, ALA and hemolysis

Answer 25

1) X and V
2) Negative
3) Positive on both HB and RB

Question 26

Haemophilus parahaemolyticus: growth factor requirements, ALA and hemolysis

Answer 26

1) V only
2) Positive
3) Positive on both HB and RB

Question 27

Haemophilus ducreyi: growth factor requirements, ALA and hemolysis

Answer 27

1) X only
2) Negative
3) None

Question 28

Nitrate reduction for Neisseria spp?

Answer 28

Negative

Question 29

Growth on media: Neisseria gonorrheae

Answer 29

Chocolate
MTM

Not well on BAP

Question 30

Growth on media: Neisseria meningitidus

Answer 30

Chocolate
MTM
BAP

Question 31

Growth on media: Moraxella catarrhalis

Answer 31

Choc
MTM
BAP

Question 32

Tests/results that aid in ID of Moraxella catarrhalis

Answer 32

DNase pos
Catarrhalis disk pos
Nitrate reduction pos
**Cannot utilize any carbohydrates

Question 33

Which species are usually Beta lactamase positive?

Answer 33

Moraxella catarrhalis and Haemophilus influenzae

Question 34

Growth on media: Neisseria lactamica

Answer 34

Chocolate
MTM
Blood

Question 35

What is special about Haemophilus ducreyi’s gram stain?

Answer 35

School of fish