GENUS: NEISSERIA

GENUS: NEISSERIAAmany Niazy

Lab # 6

NEISSERIA SPECIESContains 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.

SPECIMENNeisseria gonorrhoea Urethral

discharge Genital swabs

(servical or rectal)

Neisseria meningitidis CSF

Fastidious organism very sensitive to environmental factors

Process specimen as

soon as possible

GRAM STAINDirect Gram Stain:

•Neisseria are intracellular organisms

•GNDC inside and outside pus cells (PMN) (kidney or bean shaped)

CULTUREInoculate into

◦ Chocolate Agar •Basal media at 40C (no solidification) add sheep blood•Keep in water bath at 70C 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

CULTUREThayer Martin (selective medium)•Contain antibiotics to inhibit other bacteria and fungi

VCNT Vancomycin, Colistin, Nystatin, Trimethoprim.

INCUBATIONTemp 35-37 ˚C ONLY

Need 5-10% CO2 to grow: CO2 envelop in anaerobic jar or Candle jar

For 48 hours

Non-pathogenic Neisseria grow at room temperature

IDENTIFICATIONGram stain GNDC

Oxidase +ve

Carbohydrate utilization test

IDENTIFICATION 1. Gram stain from plate GNDC

(Kidney shaped)

IDENTIFICATION2. All Neisseria species are

Oxidase +vePreparation 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

IDENTIFICATION3. HISS medium.broth + serum + sugar + indicator

(phenol red)

Neisseria gonorrhoeae

Neisseria meningitides

YOUR WORK FOR TODAY1. Prepare gram stain from culture.2. Do oxidase test.3. Subculture organism to chocolate

agar.4. Incubate in the CO2 jar.5. Read after 48 hours.6. See sugar utilization tube

(demonstration) 7. See intracellular GNDC slide

(demonstration slide)

• New diagnosis techniques:• Immunoassays• DNA hybridization• PCR

• Doc Kaiser’s microbiology website

http://student.ccbcmd.edu/~gkaiser/goshp.htm

Numbers in Saudi Population

13 cases of meningococcal meningitis in 2007

THANK YOU