Neisseria spp. Flashcards
Gram Negative Dipplococci
Neisseria spp.
Moraxella spp.
Grows on Chocolate + Blood agar 5-10% CO2, 37C
Neisseria, Moraxella, Haemophilus
Neisseria culture conditions
5-10% CO2, 37C, chocolate agar (maybe blood agar too)
Neisseria colonies on chocolate agar
1-2mm, grey, round, smooth, wet, no haem
Neisseria spp. basic characteristics
Gram negative dipplococci (coffee bean shaped)
KOh positive
Oxidase positive
Catalase positive
Oxidase Positive bacteria
Neisseria, Moraxella, Haemophilus, Pseudomonas
Presumptive Neisseria spp tests
- Taxo Sugar Utilization Test
Taxo Sugar Utilization test procedure
- Prepare heavy inoculum of test isolate using 5ml sterile water.
- Lawn over entire chocolate agar.
- Place 4 taxo discs on surface of inoculum - spread apart evenly.
- Incubate at 37C for 24-48hrs.
Control = N.lactamica - Following incubation, place agar in fume hood and add drop of phenol red indicator to each disc.
Pos = red -> yellow colour change.
Neisseria additional confirmatory tests
Vitek + Maldi-Tof
If N. meningitis - sent to ISMRL in Temple Street for PCR.
Neisseria meningitis infection
Commensal in 10-15% ppl.
1. BSI aka meningococcaemia - can lead to Disseminated Intravascular Coagulation (DIC).
2. Meningitis - fever, headache, stiff neck, rash.
Neisseria Gonorrhoea infections
Not a commensal , STI.
Causes urethritis (urethra infection) in men.
Asymptomatic in women.
Neisseria specimens
Genital -> urethral /cervical swab.
CSF, Blood.
Taxo Sugar Utilization test results
N. Gonorrhoea = glucose positive
N. meningitis = glucose + maltose positive
N. lactamica = glucose + maltose + lactose positive.
Is neisseria spp. fastidious?
YES
Heavy inoculum in lawning of chocolate agar (taxo sugar utilization test).
