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NEISSERIA

NEISSERIA. Gram negative diplococci Aerobic, Catalase –ve, Oxidase +ve Pathogenic – N.meningitidis, N.gonorrhoeae Non-pathogenic – commensals in oral cavity ; N.flavescens, N.sicca. NEISSERIA MENINGITIDIS. Intracellular diplococci; Gram negative Culture – Blood agar, Chocolate agar,

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NEISSERIA

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  1. NEISSERIA

  2. Gram negative diplococci • Aerobic, Catalase –ve, Oxidase +ve • Pathogenic – N.meningitidis, N.gonorrhoeae • Non-pathogenic – commensals in oral cavity ; N.flavescens, N.sicca

  3. NEISSERIA MENINGITIDIS • Intracellular diplococci; Gram negative • Culture – • Blood agar, Chocolate agar, • Thayer Martin medium with Vancomycin, colistin, nystatin & trimethoprim • Obligate aerobes; 5-10% CO2 • Gluocse & maltose fermented with acid only • Oxidase test – 1% tetramethyl paraphenylene diamine hydrochloride

  4. +ve - ve

  5. Gram stain of Neisseria meningitis

  6. Classification • 13 serogroups – A,B,C,D,X,Y,Z,W135,29E • H,I,K,L. • Group B & C – serotypes based on outer membrane proteins • Group A, B, C, 29E, W135 & Y – cause meningitis • Children below 5 years • A & B epidemics • C – sporadic outbreaks

  7. PATHOGENSIS • Source – Nasopharynx of carriers • Route of infection – Inhalation – perineural sheath of olfactory nerve or hematogenous • Incubation period – 3 days • Acute fever with petechial rash • Water house Friderichsen syndrome – disseminated intravascular coagulation, shock & multiorgan failure • C5 –C9 deficiency

  8. Haemorrhagic rash

  9. Death from Waterhouse-Friderichsen syndrome

  10. Neck rigidity

  11. Lab diagnosis • Specimen – CSF, Blood, swabs from petechial lesions, nasopharyngeal sawbs • Stuart’s transport media • Microscopy - Gram negative diplococci within polymorphs • Capsular polysaccharide Antigen detection by latex agglutination • Culture – BA, CA, Glucose broth, Bile broth

  12. Treatment & Prophylaxis • Penicillin G, Chloramphenicol – Intrathecal • Carriers – Rifampicin or Ciprofloxacin • Vaccine • Polysaccharide of A,C,W 135, Y • Single dose intramuscularly • Duration of Immunity – 3 years

  13. Neisseria gonorrhoeae

  14. NEISSERIA GONORRHOEAE • Gram negative diplococci, bean shaped • Intracellular within polymorphs • Pili for adhesion; agglutinates RBC’s • Culture – BA, CA, Thayer martin agar • 4 colony types – T1 – T4 • T1 & T2 – virulent; pili present; small brown colonies • T3 & T4 – avirulent; pili absent; large non-pigmented colonies

  15. Oxidase +ve; ferments glucose but not maltose • ANTIGENIC STRUCTURE • Capsule – polyphosphate • Pili – protein; variable • LPS – endotoxin • Outer membrane proteins • Protein1/ Por protein - either A or B; 24-1A & 32-1B • Protein2/ Opa protein- adhesion; opaque colonies • Protein3/ Rmp protein – transport of molecules • IgA protease • Beta lactamse enzyme

  16. Pathogenesis • Sexually transmitted • Adhesion to mucosal surfaces by Pili • Adhesion stabilized by Opa protein • Migration to epithelial cells • Multiplication and colonization in sub epithelial space • Por protein protects from Phagocytosis • Endotoxin activates TNF alpha • Incubation period 2 – 8 days

  17. Clinical syndromes • Urethritis – dysuria & sponatneous purulent discharge • Multiple draining sinuses – water can perinium • Epididymitis, prostatitis • Cervicitis - only 50% have dysuria & discharge • Vulvovaginitis • Pelvic inflammatory disease • Optahlmia neonatorum • Fitz-Hugh-Curtis syndrome – perihepatic inflammation • Disseminated infection – septic arthritis, meningitis, osetomyelitis

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

  19. Lab diagnosis • Specimen - urethral / cervical discharge. Chronic urethritis in male – prostatic massage • Transport – Stuart’s media • Culture – BA, CA ,Thayer martin medium • Oxidase +ve; ferments glucose but not maltose • Blood culture in disseminated cases

  20. Treatment • Penicillin - PPNG • Low level resistance – Chromosome mediated • High level resistance - Plasmid mediated • Ceftriaxone, • Ciprofloxacin + doxycycline / erytromycin / azitromycin

  21. Antimicrobial Resistance • Gonococcal strains resistant to: • Penicillins • Tetracyclines • Spectinomycin • Fluoroquinolones • Presently, ciprofloxacin and ofloxacin recommended by CDC for treatment

  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

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