Neisseria

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Chapter No # 05
NEISSERIA
Genus: Neisseria
G-ve, diplococci, kidney shaped
Oxidase: +ve
Neisseria gonorrhoeae
N. gonorrhoeae
Gonorrhoea
Virulence Factors
Factor Responsible for:
1. Pili Attachment to epithelial cell
2. OMP II (PrII) Invasion of epithelial cells
3. OMP I (PrI) Invasion of epithelial cells
4. LPS Damage to epithelial cells
5. IgA protease Destruction of secretary Ab
Clinical Significance
i. Transmitted by direct, close, usually sexual
 contact between individuals.
 Uncomplicated gonorrhoea:
 In men: acute urethritis >purulent discharge
 in women (endocervix): vaginal discharge
 asymptomatic:
ii. Conjunctivitis (ophthalmia neonatorum): also known as pink eye, is inflammation of the
outermost layer of the white part of the eye and the inner surface of the eyelid
iii. Pelvic inflamatory disease (PID): is an infection of the upper part of the female reproductive
system namely the uterus, fallopian tubes, and ovaries, and inside of the pelvis.

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Chapter No # 05
iv. Disseminated gonococcal infection (DGI): results from bacteremic spread of the sexually
transmitted pathogen, Neisseria gonorrhoeae, which can lead to a variety of clinical symptoms
and signs, such as arthritis or arthralgias, tenosynovitis, and multiple skin lesions.
Laboratory Diagnosis
1. Specimens: Transport media!!!!
 Men: Urethral samples.
 Women: Uretheral, cervical and rectal specimens.
2. Endocervical swab >>
3. In DGI:
 Blood, swabs from skin lesions, or pus aspirated from a joint.
4. In neonatal ophthalmia: Conjunctival material.
5. Urine specimen:
6. Gram stain
7. Thayer-Martin Media:(or Thayer-Martin medium) is a Mueller-Hinton agar with 5% chocolate
sheep blood and antibiotics. It is used for culturing and primarily isolating pathogenic Neisseria
bacteria, including Neisseria gonorrhoeae and Neisseria meningitides
8. Oxidase test
9. Carbohydrate utilization
10. Oxidase test
Kovac’s oxidase test determines the presence of cytochrome oxidase. Kovac’s oxidase reagent,
tetramethyl-p-phenylenediamine dihydrochloride, is turned into a purple compound by
organisms containing cytochrome oxidase
11. Carbohydrate utilization
4 different carbohydrates (glucose [also called dextrose], maltose, lactose, and sucrose) are used
in the media and different species utilize different carbohydrate.
Treatment
 N. gonorrhoeae > β-lactamase
 3rd
generation cephalosporins
 Ceftriaxone
Ciprofloxacin: resistance?
N. meningitidis
Virulence Factors: > Capsule.
Serological Classification:
 Serogroups A, B, and C.
 Others: X, Y, Z, Z' (29E), and W-135

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Chapter No # 05
Gram-stain of Neisseria meningitidis Gram-negative diplococcic
Clinical Significance
Habitat: Oro- or naso-pharynges of asymptomatic carriers
Transmission:
Meningococcemia and/or meningitis >
- rash
- "Waterhouse-Friderchsen syndrome“hemorrhagic adrenalitis or fulminant
meningococcemia is defined as adrenal gland failure due to bleeding into the adrenal glands
Pneumonia >
Laboratory Diagnosis
 Specimens: >> Transport media !!!!!
 CSF, blood, aspirate from skin lesions or pus from an infected joint.
 Carriers:
 Gram stain & Blood agar/ TM medium
 Grouping: Specific antisera.
 CSF: can be examined for meningococcal, polysaccharide antigen by
 latex , agglutination , coagglutination, etc...
CCoonnttrrooll
 Chemoprophylaxis.
 Vaccination.
TTrreeaattmmeenntt
 Penicillin
 Rifampicin
 Ciprofloxacin
Prepared By Amjad Khan Afridi Date: 18t h
March, 2017