A 22-year-old sexually active woman presents with lower abdominal pain, cervical motion tenderness, and mucopurulent cervical discharge. Gram stain of the discharge shows Gram-negative intracellular diplococci within PMNs. Culture on Thayer-Martin medium shows oxidase-positive colonies. The organism ferments glucose but NOT maltose. Which organism is responsible?
- A Neisseria meningitidis
- B Chlamydia trachomatis
- C Neisseria gonorrhoeae ✓
- D Trichomonas vaginalis
Correct answer: C. Neisseria gonorrhoeae
Explanation
Neisseria gonorrhoeae ferments only glucose (not maltose, sucrose, or lactose), which differentiates it from N. meningitidis that ferments both glucose and maltose. It causes pelvic inflammatory disease (PID), presenting with cervical motion tenderness. Gram-negative intracellular diplococci within PMNs on smear is characteristic. Thayer-Martin medium (containing vancomycin, colistin, nystatin) selectively grows Neisseria. Chlamydia is an obligate intracellular organism not visualised by Gram stain.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.