NAAT (nucleic acid amplification test) is preferred over culture for detection of Chlamydia trachomatis in urogenital specimens because:

• A NAAT requires only 2 hours, while culture requires 48–72 hours for isolation
• B NAAT simultaneously determines antibiotic susceptibility pattern
• C Culture for Chlamydia cannot be performed on urethral specimens
• D NAAT detects both viable and non-viable organisms, allowing use of non-invasive specimens ✓

Explanation

NAAT for Chlamydia trachomatis is far more sensitive (>90%) than culture (60–80%) because it detects nucleic acids from both viable and non-viable organisms and can be performed on self-collected specimens (first-catch urine, vaginal swabs) without requiring viable organisms or transport in specialized media. Culture requires live organisms, appropriate cell lines (McCoy cells), centrifugation, and 48–72 hours, and is largely reserved for medico-legal cases or susceptibility testing. NAAT does not provide susceptibility data, but C. trachomatis resistance to azithromycin is rare in clinical practice.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.