A veterinarian develops a malignant pustule on his hand after handling a dead cow. Culture of the lesion grows non-motile, Gram-positive rods with a polypeptide capsule. What is the biochemical composition of this antiphagocytic capsule?

• A Polysialic acid
• B Polysaccharide containing N-acetylmannosamine
• C Hyaluronic acid
• D Poly-D-glutamic acid ✓

Explanation

Bacillus anthracis is unique among bacteria in having a capsule composed of poly-B-glutamic acid, which is antiphagocytic and poorly immunogenic. Polysialic acid is the capsule of Neisseria meningitidis group D and E. coli K1. Hyaluronic acid is the capsule of Streptococcus pyogenes. N-acetylmannosamine is part of the Group D Streptococcus capsule.

Reference: Ananthanarayan and Panicker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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