GENUS NEISSERIA Amany Niazy Lab 6 NEISSERIA SPECIES

GENUS: NEISSERIA Amany Niazy Lab # 6

NEISSERIA SPECIES �Contains many species; 2 are human pathogens ◦ Neisseria gonorrhoea (gonococcus) ◦ Neisseria meningitidis (meningococcus) �Other species are normal flora that inhabit the upper respiratory tract of humans.

SPECIMEN �Neisseria gonorrhoea Urethral discharge Genital swabs (servical or rectal) �Neisseria meningitidis CSF �Fastidious organism very sensitive to Process specimen environmental factors as soon as possible

GRAM STAIN �Direct Gram Stain: • Neisseria are intracellular organisms • GNDC inside and outside pus cells (PMN) (kidney or bean shaped)

CULTURE �Inoculate into ◦ Chocolate Agar • Basal media at 40 C (no solidification) add sheep blood • Keep in water bath at 70 C to hemolyse blood • This releases and denatures many RBCs and serum proteins, making them more readily digestible to the bacteria • Colonies appear: Colorless , raised, 1 -2 mm in diameter

CULTURE �Thayer Martin (selective medium) • Contain antibiotics to inhibit other bacteria and fungi VCNT Vancomycin, Colistin, Nystatin, Trimethoprim.

INCUBATION �Temp 35 -37 ˚C ONLY Non-pathogenic Neisseria grow at room temperature �Need 5 -10% CO 2 to grow: �CO 2 envelop in anaerobic jar or �Candle jar �For 48 hours

IDENTIFICATION �Gram stain GNDC �Oxidase +ve �Carbohydrate utilization test

IDENTIFICATION 1. Gram stain from plate GNDC (Kidney shaped)

IDENTIFICATION 2. All Neisseria species are Oxidase +ve Preparation of Oxidase Test: • Add filter paper on a clean slide • Add 2 -3 drops of oxidase reagent on filter paper • Use cover slip to transfer colony onto filter paper • + ve Purple color

IDENTIFICATION 3. HISS medium. broth + serum + sugar + indicator (phenol red) Neisseria meningitides Neisseria gonorrhoeae

YOUR WORK FOR TODAY 1. 2. 3. 4. 5. 6. 7. Prepare gram stain from culture. Do oxidase test. Subculture organism to chocolate agar. Incubate in the CO 2 jar. Read after 48 hours. See sugar utilization tube (demonstration) See intracellular GNDC slide (demonstration slide)

• New diagnosis techniques: • Immunoassays • DNA hybridization • PCR • Doc Kaiser’s microbiology website http: //student. ccbcmd. edu/~gkaiser/goshp. ht m

Numbers in Saudi Population 13 cases of meningococcal meningitis in 2007

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