Fastidiosos

Neisseria gonorrhoeae

Intracellular Gram-negative diplococci

Identification & Growth

Identification

Oxidase-positive, catalase-positive
Ferments only glucose (not maltose, which differentiates it from meningococcus)

Growth Conditions

Thayer-Martin/Martin-Lewis medium, 35–37 °C with 5% CO₂, 24–48 h
Highly sensitive to cold and desiccation — plate immediately

Clinical Significance

Urethritis, cervicitis, pelvic inflammatory disease, neonatal conjunctivitis

Intrinsic Resistance

Vancomycin, clindamycin, linezolid, daptomycin, trimethoprim

Bench Alerts

A direct Gram stain of male urethral discharge already has high diagnostic value
Ciprofloxacin and penicillin resistance rates are high — empirical treatment is ceftriaxone
Inadequate transport is the main cause of a false-negative culture

Clinical Notes

Clinical presentations

Causes urethritis, cervicitis, proctitis, and pharyngitis, frequently asymptomatic in women and in extragenital infections.
Can ascend causing pelvic inflammatory disease, with risk of infertility and ectopic pregnancy.
Disseminated gonococcal infection causes septic arthritis, tenosynovitis, and pustular skin lesions.
Neonatal conjunctivitis (ophthalmia neonatorum) occurs via vertical transmission during delivery.

Specimens and collection

Nucleic acid amplification tests (NAAT) on urethral, endocervical, rectal, or pharyngeal specimens are the current diagnostic method of choice.
Culture on selective medium (Thayer-Martin) remains necessary when antimicrobial susceptibility testing is required.
Specimens should be transported promptly and kept warm, as the organism is sensitive to cold and desiccation.

Epidemiology and at-risk populations

Is one of the most common bacterial sexually transmitted infections globally, with highest incidence in sexually active young adults.
Coinfection with Chlamydia trachomatis is common, justifying combined testing and treatment in clinical practice.
WHO classifies N. gonorrhoeae as a high-priority pathogen due to rising antimicrobial resistance.

Resistance and therapeutic implications

Progressive resistance has already eliminated penicillins, tetracyclines, fluoroquinolones, and more recently azithromycin as reliable empiric options in many regions.
Single-dose injectable ceftriaxone is currently the mainstay of empiric treatment recommended by international guidelines.
Strains with reduced susceptibility to extended-spectrum cephalosporins have been reported, prompting ongoing laboratory surveillance.

Bench and reporting notes

Gram-negative intracellular diplococci within polymorphonuclear cells on Gram stain of male urethral discharge are highly suggestive.
Positive oxidase test and acid production from glucose (but not maltose) differentiate it from N. meningitidis on biochemical identification.
Confirmed cases are notifiable, requiring sexual partner tracing and treatment.

Sources

Educational decision-support content. It does not replace laboratory validation, current guidelines or review by the responsible professional.

FAQ: Frequently Asked Questions

How to identify Neisseria gonorrhoeae in the lab?

Neisseria gonorrhoeae is identified through oxidase-positive, catalase-positive, ferments only glucose (not maltose, which differentiates it from meningococcus).

What are the intrinsic resistances of Neisseria gonorrhoeae?

This organism is naturally resistant to vancomycin, clindamycin, linezolid, daptomycin, trimethoprim. These drugs should not be reported as susceptible.

Where is Neisseria gonorrhoeae commonly found?

It is typically associated with urethritis, cervicitis, pelvic inflammatory disease, neonatal conjunctivitis.

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