NEISSERIA. Introduction The Neisseriae are G-ve diplococci Pathogens are:- N.meningitidis ...

NEISSERIANEISSERIA

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

N. gonorrhoeaeN. 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.

Gram stain of N.gonorrhoea

Selective mediaSelective media

Thayer-Martin medium contains vancomycin, colistin, nystatin & trimethoprim.

Colonies: 48hrs incubation.

IdentificationIdentification

Oxidase +ve. Carbohydrate utilization: N.gonorrhoeae

produces acid from glucose only. Slide agglutination with specific antisera

(Phadebact test).

PathogenicityPathogenicity

Causes gonorrhoea Arthritis, Septicemia, Ophthalmia neonatorum.

GonorrhoeaGonorrhoea

Acute pyogenic infection of urethra and (in females) cervix.

Acute purulent urethral , vaginal discharge , dysuria Asymptomatic in females Rectum & oropharynx may be involved.

ComplicationsComplications

Prostatitis, epididymitis , urethral stricture in males.

Salpingitis , infertility in females Septicemia Arthritis Meningitis (rare).

DiagnosisDiagnosis

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 gonorrhoeaTreatment of gonorrhoea

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

N. meningitidisN. 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.

Gram stain of Neisseria meningitis

Haemorrhagic rash

Death from Waterhouse-Friderichsen syndrome

Neck rigidity

Antigenic structureAntigenic structure

Polysaccharide antigens Three main groups A,B,C Other groups Y,W135. Grouping: slide agglutination with specific

antisera

PathogenicityPathogenicity

Meningococcal meningitis, as a spread from nasopharynx blood stream meninges in susceptible hosts.

Direct spread to meninges Rash Adrenal haemorrhage (Waterhouse-Friderchsen

syndrome)

MeningitisMeningitis

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)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.

TreatmentTreatment

Parenteral antimicrobial Start blind treatment after collection of specimens

by: Ceftriaxone or cefotaxime Change later according to sens. Test. Contacts: rifampicin Prevention: vaccination (polyvalent)

Commensal NeisseriaeCommensal 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

Other causes of meningitisOther 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.

Other causative bacteria (Continue)Other causative bacteria (Continue)

E.coli & other coliforms Listeria Strept.group B Salmonella spp. Favobacteria.. All common in neonates

After surgery or trauma S.aureus S.pneumoniae AFB chronic meningitis Spirochaetes

Other causative bacteria (ContinueOther causative bacteria (Continue

Other CausesOther Causes

Viral :enterivirus, Paramyxovirus, Herpes

viruses, adenoviruses, arboviruses. Fungi: yeasts (Candida, cryptococcus spp.) Aspergillus spp. Mucor

Findings in CSFFindings in CSF

Normal CSF:

Clear , colorless 0-5 lymphocytes Sterile 150-450 mg /l protein 2.8-3.9mmol/l glucose

CSF in bacterial meningitisCSF in bacterial meningitis

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

CSF in TB meningitisCSF 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

CSF in viral meningitisCSF in viral meningitis

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

Cerebral abscessCerebral 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

Complication of meningitisComplication of meningitis

Death ( 30% with pneumococci,10% Hi & N.meningitidis.

Ventriculitis hydrocephalus Paralysis Cerebral abscess..

Treatment of meningitisTreatment of meningitis

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