NEISSERIA Introduction The Neisseriae are Gve diplococci Pathogens

NEISSERIA

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

N. gonorrhoeae Obligate parasite of human urogenital tract. Ø Morphology: Gram -ve diplococci (bean shaped). Ø Culture: enriched media (lysed blood or chocolate), moist aerobic atmosphere +5 -10% CO 2. Temp. 3537 o. C. Ø

Gram stain of N. gonorrhoea

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

Identification Ø Oxidase +ve. Ø Carbohydrate utilization: N. gonorrhoeae produces acid from glucose only. Ø Slide agglutination with specific antisera (Phadebact test).

Pathogenicity Causes gonorrhoea Ø Arthritis, Ø Septicemia, Ø Ø Ophthalmia neonatorum.

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

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

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

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

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

Gram stain of Neisseria meningitis

Haemorrhagic rash

Death from Waterhouse-Friderichsen syndrome

Neck rigidity

Antigenic structure Ø Polysaccharide antigens Ø Three main groups A, B, C Ø Other groups Y, W 135. Ø Grouping: slide agglutination with specific antisera

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

Meningitis Ø Ø Ø 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

Meningitis (Continue) Culture deposit into blood & chocolate agars and glucose broth 7 cooked meat media Ø Incubate in air + 5%CO 2 Ø Id : sugar utilization + latex Ø For partially treated meningitis: detection of bacterial antigen by: latex agglu, CCIE. . for common serogroups of meningitis pathogens. Ø

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

Commensal Neisseriae N. pharyngis, N. flava, N. sicca, . . Ø In mucous mem. Of mouth, nose, pharynx, less common in genital tract. Ø Differ. From pathogenic one: Ø grow in ordinary media( no CO 2) § at room temp. § rough, pigmented § acid from a number of CHOs §

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

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

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

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

Findings in CSF Normal CSF: Ø Clear , colorless Ø 0 -5 lymphocytes Ø Sterile Ø 150 -450 mg /l protein Ø 2. 8 -3. 9 mmol/l glucose

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

CSF in TB meningitis Ø Ø Ø 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

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

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

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

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