1 / 34

NEISSERIA

NEISSERIA. Introduction. The Neisseriae are G-ve diplococci Pathogens are:- N.meningitidis N.gonorrhoeae Exacting growth requirements Commensals easy to grow on ordinary media. N. gonorrhoeae. Obligate parasite of human urogenital tract. Morphology: Gram -ve diplococci (bean shaped).

lot
Télécharger la présentation

NEISSERIA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NEISSERIA

  2. Introduction • The Neisseriae are G-ve diplococci • Pathogens are:- N.meningitidis • N.gonorrhoeae • Exacting growth requirements • Commensals easy to grow on ordinary media

  3. N. gonorrhoeae • Obligate parasite of human urogenital tract. • Morphology: Gram -ve diplococci (bean shaped). • Culture: enriched media (lysed blood or chocolate), moist aerobic atmosphere +5-10% CO2. Temp.35-37oC.

  4. Gram stain of N.gonorrhoea

  5. Selective media • Thayer-Martin medium contains vancomycin, colistin, nystatin & trimethoprim. • Colonies: 48hrs incubation.

  6. Identification • Oxidase +ve. • Carbohydrate utilization: N.gonorrhoeae produces acid from glucoseonly. • Slide agglutination with specific antisera (Phadebact test).

  7. Pathogenicity • Causes gonorrhoea • Arthritis, • Septicemia, • Ophthalmia neonatorum.

  8. Gonorrhoea • Acute pyogenic infection of urethra and (in females) cervix. • Acute purulent urethral , vaginal discharge , dysuria • Asymptomatic in females • Rectum & oropharynx may be involved.

  9. Complications • Prostatitis, epididymitis , urethral stricture in males. • Salpingitis , infertility in females • Septicemia • Arthritis • Meningitis (rare).

  10. Diagnosis • Specimen: urethral,cervical smears &swabs (transport medium). • Gram film: intracellular Gram -ve diplococci • Culture: selective media • Oxidase +ve • acid production from glucose • Latex agglutination

  11. Treatment of gonorrhoea • One curative dose • Sens. Testing • Blind treatment: ceftriaxone,ciprofloxacin • Spectinomycin • Penicillin: resistance common.

  12. N. meningitidis • Habitat: human nasopharynx (10-25%) • Similar to N. gonorrhoea but less exacting ? • Can grow in BA, Chocolate agar without selective media from CSF ? • Id. CHO utilization: acid from glucose& maltose.

  13. Gram stain of Neisseria meningitis

  14. Haemorrhagic rash

  15. Death from Waterhouse-Friderichsen syndrome

  16. Neck rigidity

  17. Antigenic structure • Polysaccharide antigens • Three main groups A,B,C • Other groups Y,W135. • Grouping: slide agglutination with specific antisera

  18. Pathogenicity • Meningococcal meningitis, as a spread from nasopharynx blood stream meninges in susceptible hosts. • Direct spread to meninges • Rash • Adrenal haemorrhage (Waterhouse-Friderchsen syndrome)

  19. Meningitis • Clinically: rapid deterioration of flu like illness • Headache, neck stiffness, +ve kerning’s sign, fever,..… • Diagnosis: CSF + blood culture • CSF: WBC , RBCs • Gram stain: bacteria & cells

  20. Meningitis (Continue) • Culture deposit into blood & chocolate agars and glucose broth 7 cooked meat media • Incubate in air + 5%CO2 • Id : sugar utilization + latex • For partially treated meningitis: detection of bacterial antigen by: latex agglu, CCIE.. for common serogroups of meningitis pathogens.

  21. Treatment • Parenteral antimicrobial • Start blind treatment after collection of specimens by: • Ceftriaxone or cefotaxime • Change later according to sens. Test. • Contacts: rifampicin • Prevention: vaccination (polyvalent)

  22. Commensal Neisseriae • N.pharyngis, N.flava, N.sicca,.. • In mucous mem. Of mouth,nose, pharynx, less common in genital tract. • Differ. From pathogenic one: • grow in ordinary media( no CO2) • at room temp. • rough, pigmented • acid from a number of CHOs

  23. Other causes of meningitis • Bacterial causes: • Three primary pathogens: • N. meningitidis, HI, S.pneumoniae • N.menningitidis all ages • HI 2m-5y • S.pneumoniae all ages but more common in adult with underlying illnesses.

  24. Other causative bacteria (Continue) • E.coli & other coliforms • Listeria • Strept.group B • Salmonella spp. • Favobacteria.. • All common in neonates

  25. Other causative bacteria (Continue • After surgery or trauma • S.aureus • S.pneumoniae • AFB chronic meningitis • Spirochaetes

  26. Other Causes • Viral :enterivirus, Paramyxovirus, Herpes viruses, adenoviruses, arboviruses. • Fungi: yeasts (Candida, cryptococcus spp.) • Aspergillus spp. • Mucor

  27. Findings in CSF Normal CSF: • Clear , colorless • 0-5 lymphocytes • Sterile • 150-450 mg /l protein • 2.8-3.9mmol/l glucose

  28. CSF in bacterial meningitis • Turbid • 500-20,000 cells mainly polys,few lymphocytes • Bacteria in Gram stain • Markedly raised protein • Reduced or absent glucose

  29. CSF in TB meningitis • Clear or slightly turbid • 10-500 cells,mainly lymphocytes( polys early) • AFB in Z-N stain • Grow in LJ medium • Moderately raised protein • Sugar reduced

  30. CSF in viral meningitis • Clear or slightly turbid • 10-500 cells mainly lymphocytes • Stool culture, or serology +ve • Normal or slightly raised protein • Normal glucose

  31. Cerebral abscess • Clear or slightly turbid • Bacteria: S. milleri, Bacteroides, S.aureus. Proteus(Causative bacteria) • 0-500 mainly polymorphs • Often no organisms in CSF • Normal or raised protein • Normal glucose

  32. Complication of meningitis • Death ( 30% with pneumococci,10% Hi & N.meningitidis. • Ventriculitis • hydrocephalus • Paralysis • Cerebral abscess..

  33. Treatment of meningitis • Depends on age ,causal bacteria • Urgent ,parenteral • Ceftriaxone • Neonates: amp+ gm (or ceftriaxone) • Sens.testing • Anti TB

More Related