Aerobic Gram Negative Cocci

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Aerobic Gram Negative Cocci

• Student Lab
• Division of Medical Technology
• Jeanne Filbey, MT(ASCP)

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General Characteristics
Aerobic GNDC

• Normal flora of upper respiratory, alimentary and
  genitourinary tracts
• Gram stain GNDC
• Oxidase positive
• Catalase positive
• Non-motile

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Neisseria gonorrhoeae
Aerobic GNDC

• Fastidious
• Temperature sensitive
• Culture immediately
• Transport media if delay

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Specimen Gram Stain
Neisseria gonorrhoeae

• Intracellular GNDC

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Colony Morphology
Neisseria gonorrhoeae

• Chocolate agar
• Thayer-Martinagar
• Growth
• Contains antibiotics

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Identification
Neisseria gonorrhoeae

• Carbohydrates
• Glucose pos
• Maltose neg
• Lactose neg
• Sucrose neg
• DNase neg
• Nitrate neg
• Butyrate esterase neg

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Pathogenesis
Neisseria gonorrhoeae

• Port of entry
• Progression of infection
• Human to human transfer
• Females asymptomatic

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Gonorrhea
Neisseria gonorrhoeae

• Male
• Acute urethritis, prostatitis and epididymitis if
  untreated
• Female
• May be asymptomatic
• Cervicitis --gt pelvic inflammatory disease --gt
  scarring of fallopian tubes --gt sterility,
  ectopic pregnancies

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Other Infections
Neisseria gonorrhoeae

• Disseminated gonococcal infection
• Pharyngitis
• Gonococcal ophthalmia neonatorum
• Vulvovaginitis

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Treatment
Neisseria gonorrhoeae

• Antimicrobial testing

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Neisseria meningitidis
Aerobic GNDC

• Fastidious
• Temperature sensitive
• Culture immediately
• Occasionally grows on SBA

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Specimen Gram Stain
Neisseria meningitidis

• GNDC

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Colony Morphology
Neisseria meningitidis

• Chocolate agar
• Thayer-Martinagar
• Growth

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Identification
Neisseria meningitidis

• Carbohydrates
• Glucose pos
• Maltose pos
• Lactose neg
• Sucrose neg
• DNase neg
• Nitrate neg
• Butyrate esterase neg

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Pathogenesis
Neisseria meningitidis

• Meningitis
• Septicemia
• Septic arthritis
• Endocarditis
• Pneumonia
• Urethritis
• Asymptomatic nasopharyngeal carriers

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Neisseria lactamica
Aerobic GNDC

• Normal flora

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Colony Morphology
Neisseria lactamica

• Chocolate agar
• Thayer-Martinagar
• Growth

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Identification
Neisseria lactamica

• Carbohydrates
• Glucose pos
• Maltose pos
• Lactose pos
• Sucrose neg
• DNase neg
• Nitrate neg
• Butyrate esterase neg

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Moraxella (Branhamella) catarrhalis
Aerobic GNDC

• Can be normal respiratory flora

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Colony Morphology
Moraxella (Branhamella) catarrhalis

• Sheep blood agar
• Chocolate agar
• Thayer-Martinagar
• Growth

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Identification
Moraxella (Branhamella) catarrhalis

• Carbohydrates
• Glucose neg
• Maltose neg
• Lactose neg
• Sucrose neg
• DNase pos
• Nitrate pos
• Butyrate esterase pos

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Pathogenesis
Moraxella (Branhamella) catarrhalis

• Acute bronchitis
• Pneumonia
• Meningitis
• Seen in immunocompromised patients (elderly)
• Otitis media maxillary sinusitis in kids
• Most produce beta lactamase

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Summary
Aerobic GNDC

• Specimen handling and processing
• Growth characteristics
• Identification
• Clinical significance
• Antimicrobial testing

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Who am I?
Urethral gram stain
Thayer Martin agar
Neisseria gonorrhoeae
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Who am I?
CSF gram stain
Chocolate agar
Neisseria meningitidis