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BANA Test — MFDS Part 1 MCQ

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HardMicrobiologyBANA TestMFDS Part 1

A pooled subgingival plaque specimen produces a strong positive reaction on a chairside N-benzoyl-DL-arginine-2-naphthylamide (BANA) card. Which group comprises the organisms classically associated with strong BANA hydrolysis?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia

Explanation lettering: C = shown as A · E = shown as B · B = shown as C · A = shown as E

The correct answer is A. The BANA card demonstrates hydrolysis of the synthetic substrate N-benzoyl-DL-arginine-2-naphthylamide by trypsin-like peptidase activity classically associated with Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia—the periodontal red-complex organisms. It is an enzyme-activity assay rather than a species-specific identification test, so a positive result cannot establish which individual member is present. The organisms in B, C and D can occur in dysbiotic subgingival biofilms but do not constitute the characteristic strongly BANA-positive group. The organisms in E are principally associated with cariogenic or commensal plaque rather than the defining BANA-hydrolysing periodontal group.

Reference: de Andrade JA et al. The ability of the BANA Test to detect different levels of P. gingivalis, T. denticola and T. forsythia. Brazilian Oral Research. 2010;24(2):224-230. https://pubmed.ncbi.nlm.nih.gov/20658043/