Unit 2 Neisseria, Moraxilla, and Haemophilus Flashcards
Gram stain: Neisseria
Gram negative Diplococci
Gram stain: Haemophilus
Gram negative Pleomorphic coccobacilli or rods
Gram stain: Moraxella catarrhalis
Gram negative Diplococci
Discuss the correct method of collection and transport necessary to recover Neisseria gonorrhoeae.
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
Choose the appropriate primary isolation media to recover Neisseria and Haemophilus species based on knowledge of content and purpose of the media.
Neisseria: Jembec and CO2 atmosphere; **Modified Thayer Martin, chocolate agar with IsoVitaleX suuplement
Haemophilus: Chocolate agar with 33-37°C, 5-10% CO2
Colony morphology: Neisseria gonorrhoeae
small, round translucent ON CHOC: tan ON BLOOD: doesn’t grow well
Colony morphology: Neisseria meningitidis
gray, convex, possibly mucoid ON CHOC: possibly greenish hue
Colony morphology: Neisseria lactamica
yellow/gold colonies
Colony morphology: Moraxella catarrhalis
smooth, opaque, gray/white colonies; “hockey puck”
Colony morphology: Haemophilus influenzae
Translucent, tan, sometimes mucoid with distinct mousy odor
Colony morphology: Haemophilus influenzae biogroup aegyptus
Same as H. influenzae but smaller colonies
Colony morphology: Haemophilus ducreyi
small, flat, smooth, translucent/opaque, “scooty”
Explain the principle and purpose: Nitrate reduction
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
Explain the principle and purpose: Carbohydrate utilization test
1) Determine which carbohydrates can be utilized for growth
2) Growth/use of carbohydrate results in color change due to pH change
Explain the principle and purpose: Porphyrin test (ALA)
1) For respiratory sources, tests presence of enzymes that make porphyrin
2) ALAporphyrinX factor
Synthesize own hemin=X factor independent=pink fluorescence under UV
Explain the principle and purpose: Catarrhalis disk
1) Detection of butyrate esterate
2) Hydrolysis of substrate releases indoxyl blue/green color
Explain the principle and purpose: DNase test
1) Determine if the organism has the enzyme DNase/can hydrolyze DNA
2) DNase in the organism will break down colorless zone
Explain the principle and purpose: Beta lactamase
1) Determine if the organism produces beta-lactamases
2) Beta lactames open beta lactam ringscolor change (pink)
Explain the principle and purpose: Haemophilus ID quad
1) Speciation
2) Growth factors V + X, horse or rabbit blood to assess hemolysis
Explain the principle and purpose: Staph streak
1) Determine V factor requirement
2) Haemophilus species that require V factor satellite around Staph on blood agar bc its produces V factor
Differentiate the saprophytic Neisseria from potentially pathogenic Neisseria species utilizing colony morphology characteristics.
Nonpathogenic typically yellow/gold colonies; except Neisseria lactamica, nonpathogenic cannot grown on MTM
Haemophilus influenzae: growth factor requirements, ALA and hemolysis
1) X and V
2) Negative
3) None
Haemophilus influenzae biogroup aegyptius: growth factor requirements, ALA and hemolysis
1) X and V
2) Negative
3) Positive on RB
Haemophilus parainfluenzae: growth factor requirements, ALA and hemolysis
1) V only
2) Positive
3) Variable on RB
