This document discusses two pathogenic Neisseria species: Neisseria gonorrhoeae, which causes gonorrhea, and Neisseria meningitidis, which causes meningitis. It covers their morphology, pathogenesis, clinical features, laboratory diagnosis, treatment and immunoprophylaxis. Key details include that N. gonorrhoeae appears as intracellular gram-negative kidney-shaped diplococci, commonly causes urethritis and pelvic inflammatory disease, and is diagnosed through culture or microscopy of samples from infected sites. N. meningitidis can cause meningitis or septicemia with a petechial rash, and is identified through culture or microscopy of CSF or blood samples.

1. NEISSERIANEISSERIA
G.HARIPRASAD M.Sc.,(Med micro),M.phil.,
Lecturer in Microbiology
Department of Microbiology
Thoothukudi Govt. Medical College
Thoothukudi

2. HUMAN PATHOGENS
• NEISSERIA GONORRHOEA - GONORRHOEA
• NEISSERIA MENINGITIDIS - MENINGITIS
NON-PATHOGENS
BRANHAMELLA CATARRHALIS
- NORMAL COMMENSAL CAUSES OPPORTUNISTIC
INFECTIONS.

3. NEISSERIA GONORRHOEA
[GONOCOCCUS]

4. MORPHOLOGY:
• GRAM NEGATIVE
DIPLOCOCCI
• COCCI ARE ARRANGED
IN PAIRS WITH
ADJACENT SIDE
CONCAVE - KIDNEY
SHAPED.
• INTRACELLULAR.

5. PATHOGENESIS:
MODE OF TRANSMISSION:
• SEXUAL CONTACT (STD)
VIRULENCE FACTOR:
▫ PILI: ATTACHMENT AND ANTIPHAGOCYTIC.
▫ CELL WALL: 2 FACTORS
• ENDOTOXIN – TOXIGENICITY.
• OUTER MEMBRANE PROTEINS(OMP) -
ATTACHMENT
• IgA PROTEASE – DESTROYS SECRETORY IgA.
REPEATED GONOCOCCAL INFECTION DUE TO
CHANGES OF PILI AND OMP

6. CLINICAL FEATURES:
• ASYMPTOMATIC URETHRAL INFECTION IN
MALE AND FEMALE – URETHRITIS -
DISCHARGE OF PUS
IN MEN:
• INFLAMMATION OF THE PERIURETHRAL
TISSUE CAUSES ABCESS AND MULTIPLE
DISCHARGING SINUSES [WATERCAN
PERINIUM].
• INFECTION EXTENDS ALONG THE
URETHRA TO PROSTATE, SEMINAL VESICLE
AND EPIDIDYMIS.
IN WOMEN:
• VULVOVAGINITIS – MUCOPURULENT
DISCHARGE.
• SALPINGITIS - INFECTION OF THE
FALLOPIAN TUBES.
• CERVICITIS.
• PELVIC INFLAMMATORY DISEASE.

7. OPTHALMIA NEONATORUM:
▫ EYE INFECTION IN THE NEWBORN.
▫ RESULTS DUE TO DIRECT INFECTION
DURING PASSAGE THROUGH THE BIRTH
CANAL.

8. LAB DIAGNOSIS
SPECIMEN:
• PUS EXUDATES - URETHRAL AND
VAGINAL.
• VAGINAL AND CERVICAL SWABS.
• TRANSPORT MEDIUM: STUART’S
MEDIUM.
DIRECT MICROSCOPY:
• INTRACELLULAR GRAM NEGATIVE
KIDNEY SHAPED DIPLOCOCCI.
• FLUORESCENT ANTIBOBY
TECHNIQUE –RAPID, SENSITIVE
AND SPECIFIC DIAGNOSIS. INTRACELLULAR GRAM
NEGATIVE DIPLOCOCCI

9. LAB DIAGNOSIS- CONT.,
CULTURE:
• CHOCOLATE AGAR.
• SELECTIVE MEDIA: THAYER
MARTIN.
• INCUBATION AT 37° C IN THE
PRESENCE OF 5-10% OF CARBON
DIOXIDE.
BIOCHEMICAL REACTION:
• GLUCOSE FERMENTATION.
• OXIDASE POSITIVE.
SEROLOGY:
• IMMUNOFLUORESCENCE.
• RIA.
• ELISA
IMMUNOFLUORESCENCE

10. TREATMENT:
• PENICILLIN.
• PPNG (PENICILLINASE PRODUCING
NEISSERIA GONORRHOEA).
• TETRACYCLIN IS ADVISABLE.
• IF IT FAILS CEPHALOSPORINS ARE
USED.
• 1% SILVER NITRATE FOR OPTHALMIA
NEONATORUM.

11. NON-GONOCOCCAL URETHRITIS
• CHRONIC URETHRITIS WHERE GONOCOCCI
CANNOT BE DEMONSTRATED.
• CAN BE CONSIDERED AS NON-SPECIFIC
URETHRITIS.
• URETHRITIS FORMS PART OF THE
SYNDROME CONSISTING OF CONJUNCTIVITIS
AND ARTHRITIS (REITER’S SYNDROME).
• MAY BE ALSO DUE TO GONOCOCCAL
INFECTION, THE COCCI PERSISTING AS L-
FORMS AND HENCE UNDETECTABLE BY
ROUTINE TESTS.

12. CAUSATIVE AGENTS:
• Chlamydia trachomatis
• Ureaplasma urelyticum.
• Mycoplasma hominis.
• Herpes virus
• Cytomegalo virus.
• Trichomonas vaginalis.
• Candida albicans.
• CAN ALSO BE DUE TO MECHANICAL OR
CHEMICAL IRRITATION.
• MANAGEMENT: DIFFICULT.

13. NEISSERIA MENINGITIDIS
[MENINGOCOCCI]

14. MORPHOLOGY:
• GRAM NEGATIVE,
SPHERICAL OR OVAL
DIPLOCOCCI WITH
ADJACENT SIDE
FLATTENED.
• THE COCCI ARE
GENERALLY
INTRACELLULAR
WHEN ISOLATED
FROM LESIONS.

15. ANTIGENIC STRUCTURE:
• THIRTEEN
SEROTYPES BASED
ON CAPSULAR
POLYSACCHARIDES.
• GROUPS A, B AND C
ARE THE MOST
IMPORTANT
SEROTYPES.

16. PATHOGENESIS:
• STRICT HUMAN PATHOGEN.
• IT CAUSES PYOGENIC MENINGITIS IN ALL
AGES, BUT IS MOST COMMON IN
CHILDREN AND YOUNG ADULTS.
• THE INFECTION IS ACQUIRED BY
DROPLET SPREAD.
• 2 CLINICAL TYPES:
▫ CEREBROSPINAL MENINGITIS
▫ MENINGOCOCCAL SEPTICEMIA.
• SEPTICEMIA PRESENTS AS ACUTE FEVER
WITH PETICHIAL RASH.
• A FEW DEVELOPS FULMINANT
MENINGOCOCCAEMIA
(WATERHOUSE FRIDERICHSEN SYNDROME)
CHARACTERIZED BY SHOCK
DISSEMINATED INTRAVASCULAR
COAGULATION AND MULTISYSTEM
FAILURE.

17. PETECHIAL RASHES IN MENINGOCOCCAL
SEPTICAEMIA

18. LAB DIAGNOSIS
SPECIMENS:
• CSF – LUMBAR
PUNCTURE
• BLOOD.
• NASOPHARYNGEAL
SWAB – ESPECIALLY TO
DETECT CARRIERS.
CSF COLLECTION
BY LUMBAR
PUNCTURE

19. CULTURAL CHARACTERISTICS:
• GROWTH OCCURS IN MEDIA
SUPPLEMENTED WITH BLOOD OR
SERUM.
• CHOCOLATE AGAR.
• BLOOD AGAR.
• SELECTIVE MEDIUM: THAYER MARTIN
MEDIUM.
• GROWTH IS ENHANCED IN 5-10%
CARBON DIOXIDE.

20. DIRECT MICROSCOPY:
• GRAM NEGATIVE,
SPHERICAL OR OVAL
DIPLOCOCCI WITH
ADJACENT SIDE
FLATTENED.
• THE COCCI ARE
GENERALLY
INTRACELLULAR
WHEN ISOLATED
FROM LESIONS.
INTRACELLULAR GRAM
NEGATIVE DIPLOCOCCI

21. BIOCHEMICAL REACTIONS:
• CATALASE AND
OXIDASE POSITIVE.
• GLUCOSE AND
MALTOSE ARE
FERMENTED WITH
ACID PRODUCTION
WITH NO GAS
(GONOCOCCI
FERMENTS GLUCOSE
BUT NOT MALTOSE).

22. SEROLOGY:
• DIRECT SLIDE AGGLUTINATION WITH
SPECIFIC ANTISERUM.
TREATMENT:
• PENICILLIN G – IV
• SULPHONAMIDES
• CHLORAMPHENICOL
• CEPHALOSPORIN.
• RIFAMPICIN AND CIPROFLOXACIN –
FOR CARRIERS

23. IMMUNOPROPHYLAXIS:
• MONOVALENT AND
POLYVALENT VACCINE
PREPARED FROM
POLYSACCHARIDES OF
SEROGROUPS A, C,
W135 AND Y IS
AVAILABLE.