3.2 Flashcards
What are the Gram stain characteristics of Neisseria gonorrhoeae?
Gram-negative diplococci.
Does Neisseria gonorrhoeae ferment glucose?
Yes
Is Neisseria gonorrhoeae part of the human microbiota?
No
What type of agar does Neisseria gonorrhoeae require for growth?
Enriched chocolate agar plate (CAP).
How is Neisseria gonorrhoeae transmitted?
Sexual contact
What body sites are primarily affected by Neisseria gonorrhoeae?
Urethra, endocervix, anal canal, pharynx, and conjunctiva.
List the virulence factors of Neisseria gonorrhoeae.
Common pili
Outer membrane proteins (I, II, III, and LOS)
Receptors for human transferrin (iron acquisition)
IgA protease
What is the principal virulence factor of Neisseria gonorrhoeae?
Common pili
What is the function of common pili in Neisseria gonorrhoeae?
Attachment to human mucosal cells
Invasion of host cells
Survival by inhibiting phagocytosis in neutrophils
What is the difference between T1-T2 and T3-T5 gonococcal strains?
T1-T2: Possess pili, virulent, small dome-shaped colonies.
T3-T5: Lack pili, avirulent, larger flatter colonies.
Mediates tissue damage and elicits an inflammatory response in Neisseria gonorrhoeae?
LOS endotoxin
Protects against the host’s inflammatory response and serum complement-mediated killing.
porB
Adherence to phagocytic and epithelial cells in Neisseria gonorrhoeae
Protein II (Opa)
What does Protein III (Rmp) do in Neisseria gonorrhoeae?
Blocks the bactericidal effect of host IgG
What enzyme in Neisseria gonorrhoeae cleaves IgA on mucosal surfaces?
IgA protease
How does Neisseria gonorrhoeae acquire iron for survival?
Through receptors for human transferrin
A pyogenic infection of non-ciliated columnar and transitional epithelium; incubation period is 2-7 days.
gonorrhea
List down the related infections and diseases caused by Neisseria gonorrhoeae
Gonorrhea
Ophthalmia neonatorum
Gonorrheal arthritis-dermatitis syndrome
What is the origin of the term “gonorrhea”?
Greek words gonos (“seed”) and rhoia (“flux”), meaning “flow of seed.
What is the colloquial term for gonorrhea, and where does it originate?
“Clap,” from the French word clapoir (“brothel”).
What are the symptoms of gonorrhea in men?
Purulent discharge and dysuria.
What are the symptoms of gonorrhea in women?
Dysuria and vaginal bleeding
List down complications under gonorrhea.
Joints: Arthritis
Heart: Endocarditis
Meninges: Meningitis
Eyes: Ophthalmia
Other parts: Pharynx, rectum
What body sites are commonly affected by gonorrhea?
Endocervix, conjunctiva, pharyngeal surfaces, anorectal area, and urethra.
What are complications of gonorrhea in men?
Prostatitis
Epididymitis
What are complications of gonorrhea in women?
Pelvic inflammatory disease (PID)
Cervicitis
Vaginal discharge
Pelvic inflammatory disease (PID)
Can cause
sterility, ectopic pregnancy, or Fitz-Hugh-Curtis syndrome (perihepatitis).
A type of perihepatitis caused by pelvic inflammatory disease (PID)
Fitz-Hugh-Curtis syndrome
Chief complaint in asymptomatic oropharyngeal infections
pharyngitis
Infection in the anorectal area.
Symptoms: Discharge, rectal pain, or bloody stools.
rectal gonorrhea
Gonococcal eye infection acquired during vaginal delivery through an infected birth canal
ophthalmia neonatorum
What are the consequences of untreated ophthalmia neonatorum?
Blindness if not treated immediately
What are the methods of preventing ophthalmia neonatorum?
Tetracycline
Erythromycin
Povidone-iodine
Silver nitrate (dilute solution or 1% Crede’s prophylaxis)
What is Crede’s prophylaxis for preventing ophthalmia neonatorum?
1-2 drops of 1% silver nitrate solution in the eyes of newborns
What is the most common manifestation of disseminated gonococcal disease?
Gonorrheal arthritis-dermatitis syndrome
What are the symptoms of gonorrheal arthritis-dermatitis syndrome?
Fever.
Chills.
Malaise.
Intermittent bacteremia.
Polyarticular arthritis or tenosynovitis.
Skin lesions.
What joints are commonly affected in gonorrheal arthritis-dermatitis syndrome
Wrist.
Knee.
Ankle.
List down the laboratory diagnostic methods for N. gonorrhoeae.
Direct gram staining.
Culture.
Biochemical tests.
Immunoserologic identification.
Molecular assays.
Antimicrobial susceptibility testing.
What specimens are collected for diagnosing Neisseria gonorrhoeae?
Urethral, cervical, anal canal, oropharyngeal, and skin lesion swabs.
Inflamed joint fluid and blood samples.
Eye discharge swabs
Which swabs are inhibitory to Neisseria gonorrhoeae?
Calcium alginate and cotton swabs.
What type of swabs are preferred for specimen collection?
Dacron or rayon swabs
What transport media can be used for Neisseria gonorrhoeae specimens?
Amies medium with charcoal
JEMBEC plates
Transgrow
Gono-Pak
Bio-Bag
What is the special feature of the JEMBEC system for transporting Neisseria gonorrhoeae?
Contains MTM medium and a CO₂-generating tablet (sodium bicarbonate + citric acid).
What substance inhibits Neisseria gonorrhoeae in sodium polyanethol sulfonate (SPS)?
SPS concentrations above 0.025%.
List down the selective culture media for Neisseria gonorrhoeae
CAP (Chocolate Agar Plate).
TMA (Thayer-Martin Agar).
MTM (Modified Thayer-Martin).
ML (Martin-Lewis).
NYC (New York City).
GC-Lect.
What are the colony characteristics of Neisseria gonorrhoeae on CAP?
Small, grayish to tan, convex, translucent, shiny colonies with smooth or irregular margins
What are the advantages of NYC medium over other media?
Supports the growth of Mycoplasma hominis and Ureaplasma urealyticum.
Which selective media inhibit swarming Proteus spp.?
Modified Thayer-Martin medium (MTM) (contains trimethoprim lactate).
GC-Lect medium (contains trimethoprim).
Which colony types are associated with virulent Neisseria gonorrhoeae strains?
T1 and T2: Smaller, raised, and bright colonies.
What does a Gram stain showing >5 PMNs/field but no bacteria indicate?
Nongonococcal urethritis (e.g., caused by Chlamydia trachomatis or Ureaplasma urealyticum)
Why should pharyngeal specimens not be Gram-stained for N. gonorrhoeae
Pharyngeal flora can complicate interpretation, leading to unreliable results
What is the best method for direct Gram staining of body fluids
Use of a cytocentrifuge
A transport and culture system for N. gonorrhoeae.
Contains:
MTM medium.
CO2-generating tablet (sodium bicarbonate + citric acid).
JEMBEC system
What is the presumptive identification test for N. gonorrhoeae
Oxidase test.
What is the reagent used in the oxidase test for Neisseria gonorrhoeae
1% dimethyl-p-phenylenediamine dihydrochloride
tetramethyl-p-phenylenediamine dihydrochloride
What is the positive result of the oxidase test for Neisseria gonorrhoeae?
Purple color within 10 seconds
What is the traditional method for carbohydrate utilization in N. gonorrhoeae
Use of cysteine trypticase soy agar (CTA) with 1% specific carbohydrate and phenol red as a pH indicator.
What carbohydrate does Neisseria gonorrhoeae ferment?
Glucose only
What reagent is used in the superoxol test for Neisseria gonorrhoeae?
30% hydrogen peroxide.
What is the result of the superoxol test for Neisseria gonorrhoeae?
Vigorous bubbling
A rapid screening test for N. gonorrhoeae
Limulus test
What does a positive DNAse test indicate
Positive: Moraxella spp.
Negative: Neisseria spp.
What is the nucleic acid amplification test (NAAT) used for in Neisseria gonorrhoeae diagnosis?
Detects gonococcal antigen or nucleic acid directly in specimens.
What specimens are used for NAAT?
Endocervical or urethral swabs; urine
What is the limitation of the chemiluminescent nucleic acid probe?
Not approved for pharyngeal or rectal specimens; cannot identify beta-lactamase-producing strains.
What are particle agglutination methods used for identifying N. gonorrhoeae?
Phadebact GC OMNI Test
MicroTrak Culture Confirmation Test
GonoGen II Test
Coagglutination assay with S. aureus cells coated with antibodies.
Phadebact GC OMNI Test
Uses FITC-antibody.
MicroTrak Culture Confirmation Test
Colorimetric test with antibodies adsorbed to metal sol particles
GonoGen II Test
Highly specific and sensitive, using monoclonal antibodies to recognize epitopes on the outer membrane protein (Por) of N. gonorrhoeae.
fluorescent antibody tests (FAT)
What does ELISA (Gonozyme) detect?
Direct detection of gonococcal antigen in specimens.
What is the advantage of NAAT?
Simultaneously detects Chlamydia trachomatis.
Less sensitive to transport and storage conditions.
What does the chemiluminescent nucleic acid probe detect
Gonococcal rRNA in genital and conjunctival specimens (1–2 hours).
What is the preferred medium for AST of N. gonorrhoeae
Gonococcal (GC) agar
What are the preferred methods for AST?
Disk diffusion or agar dilution (MIC).
What is an alternative method for AST?
E-test
What antibiotics are effective against N. gonorrhoeae?
Extended-spectrum cephalosporins and quinolones.
