Differences between Neisseria meningitidis and Neisseria gonorrhoeae 4.5/5 (2)

Differences between Neisseria meningitidis and Neisseria gonorrhoeae


Differences between Neisseria meningitidis and Neisseria gonorrhoeae

Neisseria meningitidis and Neisseria gonorrhoeae, are obligate human pathogens that cause distinctly different disease syndromes. They are both Gram negative diplococci, non-sporing, oxidase positive and difficult to differentiate on morphological and cultural characteristics.

Differences between Neisseria meningitidis and Neisseria gonorrhoeae


However, they can be differentiated on the following grounds:

S.N.

Character

Neisseria gonorrhoeae

Neisseria meningitidis

1.      Commonly CalledGonococcusMeningococcus
2.      Causative agent ofSexually transmitted disease- GonorrhoeaCauses a range of diseases embraced by the term invasive meningococcal disease. Most commonly cerebrospinal meningitis.
3.      Cell MorphologyKidney shaped with apposing ends concave.Semicircular diplococcus with flat apposing ends.
4.      CapsuleAbsentCapsule is present which is anti-phagocytic and an important virulence factor.
5.      PiliN. gonorrhoeae most often moves using one retracting pilus.N. meningitidis most often move using four pili.
6.      PlasmidsUsually possess plasmids, coding for drug resistant genes.Rarely have plasmids
7.      FormPredominantly exist in

intracellular form

Exist in both intra· and

extracellular forms

8.      MovementMovement of N. gonorrhoeae occurs at lower speed.Movement of N. meningitidis occurs faster with a larger number of retracting pili.
9.      Growth on Blood AgarN. gonorrhoeae grow less well on blood agar than N. meningitidis.N. meningitidis grow well on blood agar than N.  gonorrhoeae
10.   Culture mediumContain antimicrobials that inhibit the growth of organisms other than N. gonorrhoeae; typically vancomycin (inhibits Gram-positive bacteria), colistin (inhibits gram-negative bacteria including the commensal Neisseria spp.), trimethoprim (inhibits swarming of Proteus spp.) and nystatin or amphotericin B (antifungal agents).Blood agar, trypticase soy agar, supplemented chocolate agar, and Mueller-Hinton agar.
11.   Growth RateSlower than Meningococcus.Slow
12.   FastidiousMost fastidious among Neisseria spp.Comparatively less fastidious.
13.   Colony morphologyN. gonorrhoeae form smooth, round, moist, uniform grey/ brown colonies with a greenish colour underneath on primary isolation medium.

Mostly, has a irregular margin.

N. meningitides would form smooth, round, moist, uniform



large grey/brown colonies with a glistening surface and entire edges.

14.   Sugar FermentationProduce acid from glucose onlyProduce acid from glucose and maltose.
15.   Maltose FermentationNoYes
16.   Nitrite ReductionN. gonorrhoeae doesn’t reduce nitrites.N. meningitidis can reduce nitrites in low concentrations.
17.   AutolysisMay autolyseAutolyse
18.   GlutamylaminotransferaseNon-producerProducer
19.   Β-Lactamase ProductionCommonRare
20.   Antigen HeterogeneityMore than meningococci.Comparatively less.
21.   GroupingStrains characterized by auxotyping which recognizes reqiurements for specific nutrients.Serogroup is determined by its lipopolysaccharide capsular antigen.
22.   Normal FloraNot considered as normal flora.Many normal individuals may harbor Neisseria meningitidis in the upper respiratory tract
23.   PathogenIt is always a pathogen.It may or may not be pathogenic.
24.   Portal of EntryGenitalRespiratory
25.   Site of InfectionPrimarily causing infection of the anogenital tract.Colonizes the upper respiratory tract as a commensal and occasionally invades to

cause systemic disease. 

26.   Virulence FactorsPili, IgA proteases and production of lipopolysaccharide endotoxin.LPS capsule, IgA protease and iron utilizationfrom transferrin.
27.   Related ConditionsN. gonorrhoeae can also cause conjunctivitis, pharyngitis, proctitis or urethritis, prostatitis, and orchitis.Cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis.
28.   SpecimensTransport swab of endocervix, urethra, rectum, pharynx, conjunctiva, blood, joint fluid, aspirates from skin lesions.Cerebrospinal fluid (CSF) and blood, swab skin lesions and nasopharynx.
29.   Presence in inflammatory exudates (pus)In larger proportionsIn less numbers
30.   Prevalence and MortalityN.gonorrhoeae infections have a high prevalence and low mortality.N. meningitidis infections have a low prevalence and high mortality.
31.   SuperbugConsidered as “superbug”Not considered as “superbug”
32.   VaccinesNoSerogroup A, B, C, Y and W-135 meningococcal infections can be prevented by vaccines.

References

  1. Greenwood, D., Slack, R. C. B., Peutherer, J. F., & Duguid, J. P. (1992). Medical microbiology: A guide to microbial infections : pathogenesis, immunity, laboratory diagnosis, and control. Edinburgh: Churchill Livingstone.
  2. Sastry A.S. & Bhat S.K. (2016). Essentials of Medical Microbiology. New Delhi : Jaypee Brothers Medical Publishers.
  3. Parija S.C. (2012). Textbook of Microbiology & Immunology.(2 ed.). India: Elsevier India.
  4. https://microbiologyinfo.com/difference-between-neisseria-gonorrhoeae-and-neisseria-meningitides/
  5. https://www.jfmed.uniba.sk/fileadmin/jlf/Pracoviska/ustav-mikrobiologie-a-imunologie/NEISSERIA_AND_HAEMOPHILUS.pdf
  6. http://textbookofbacteriology.net/neisseria.html

Differences between Neisseria meningitidis and Neisseria gonorrhoeae

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