Aerobic Gram Negative Cocci

Student Lab

Division of Medical Technology

Jeanne Filbey, MT(ASCP)

General Characteristics

• Normal flora of upper respiratory, alimentary and genitourinary tracts

• Gram stain: GNDC

• Oxidase positive

• Catalase positive

• Non-motile

Aerobic GNDC

Neisseria gonorrhoeae

• Fastidious

• Temperature sensitive

• Culture immediately

• Transport media if delay

Aerobic GNDC

Specimen Gram Stain

• Intracellular GNDC

Neisseria gonorrhoeae

Colony Morphology

• Chocolate agar

• Thayer-Martinagar– Growth– Contains antibiotics

Neisseria gonorrhoeae

Identification

• Carbohydrates– Glucose pos– Maltose neg– Lactose neg– Sucrose neg

• DNase neg• Nitrate neg• Butyrate esterase neg

Neisseria gonorrhoeae

Pathogenesis

• Port of entry

• Progression of infection

• Human to human transfer

• Females asymptomatic

Neisseria gonorrhoeae

Gonorrhea

• Male– Acute urethritis, prostatitis and epididymitis

if untreated

• Female– May be asymptomatic– Cervicitis --> pelvic inflammatory disease --

> scarring of fallopian tubes --> sterility, ectopic pregnancies

Neisseria gonorrhoeae

Other Infections

• Disseminated gonococcal infection

• Pharyngitis

• Gonococcal ophthalmia neonatorum

• Vulvovaginitis

Neisseria gonorrhoeae

Treatment

• Antimicrobial testing

Neisseria gonorrhoeae

Neisseria meningitidis

• Fastidious

• Temperature sensitive

• Culture immediately

• Occasionally grows on SBA

Aerobic GNDC

Specimen Gram Stain

• GNDC

Neisseria meningitidis

Colony Morphology

• Chocolate agar

• Thayer-Martinagar– Growth

Neisseria meningitidis

Identification

• Carbohydrates– Glucose pos– Maltose pos– Lactose neg– Sucrose neg

• DNase neg• Nitrate neg• Butyrate esterase neg

Neisseria meningitidis

Pathogenesis

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

Neisseria meningitidis

Neisseria lactamica

• Normal flora

Aerobic GNDC

Colony Morphology

• Chocolate agar

• Thayer-Martinagar– Growth

Neisseria lactamica

Identification

• Carbohydrates– Glucose pos– Maltose pos– Lactose pos– Sucrose neg

• DNase neg• Nitrate neg• Butyrate esterase neg

Neisseria lactamica

Moraxella (Branhamella) catarrhalis

• Can be normal respiratory flora

Aerobic GNDC

Colony Morphology

• Sheep blood agar

• Chocolate agar

• Thayer-Martinagar– Growth

Moraxella (Branhamella) catarrhalis

Identification

• Carbohydrates– Glucose neg– Maltose neg– Lactose neg– Sucrose neg

• DNase pos• Nitrate pos• Butyrate esterase pos

Moraxella (Branhamella) catarrhalis

Pathogenesis

• Acute bronchitis

• Pneumonia

• Meningitis

• Seen in immunocompromised patients (elderly)

• Otitis media & maxillary sinusitis in kids

• Most produce beta lactamase

Moraxella (Branhamella) catarrhalis

Summary

• Specimen handling and processing

• Growth characteristics

• Identification

• Clinical significance

• Antimicrobial testing

Aerobic GNDC

Who am I?

Urethral gram stain Thayer Martin agar

Neisseria gonorrhoeae

Who am I?

CSF gram stain Chocolate agar

Neisseria meningitidis