Which media is used for Neisseria species recovery?

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Multiple Choice

Which media is used for Neisseria species recovery?

Neisseria species are fastidious Gram-negative diplococci that are easily overwhelmed by surrounding flora in clinical samples. To recover them effectively, you need a medium that is both enriched and selective to suppress competing bacteria and fungi. Thayer-Martin medium is specifically designed for this purpose. It uses a chocolate agar base enriched to support the growth of Neisseria, and it adds antimicrobial agents—vancomycin to inhibit Gram-positive organisms, colistin to suppress many Gram-negative rods, and nystatin (or similar antifungal) to prevent fungal overgrowth. This combination creates a selective environment that favors Neisseria gonorrhoeae and Neisseria meningitidis, making it the preferred choice for isolation from specimens. The other media shown aren’t selective for Neisseria. A blood agar plate designed for anaerobes targets anaerobic bacteria and lacks the selective antibiotics; chocolate agar with CO2 supports fastidious organisms but doesn’t suppress competing flora; a CNA plate with oxygen is meant to differentiate Gram-positive from Gram-negative organisms and isn’t tailored for Neisseria recovery.

Neisseria species are fastidious Gram-negative diplococci that are easily overwhelmed by surrounding flora in clinical samples. To recover them effectively, you need a medium that is both enriched and selective to suppress competing bacteria and fungi.

Thayer-Martin medium is specifically designed for this purpose. It uses a chocolate agar base enriched to support the growth of Neisseria, and it adds antimicrobial agents—vancomycin to inhibit Gram-positive organisms, colistin to suppress many Gram-negative rods, and nystatin (or similar antifungal) to prevent fungal overgrowth. This combination creates a selective environment that favors Neisseria gonorrhoeae and Neisseria meningitidis, making it the preferred choice for isolation from specimens.

The other media shown aren’t selective for Neisseria. A blood agar plate designed for anaerobes targets anaerobic bacteria and lacks the selective antibiotics; chocolate agar with CO2 supports fastidious organisms but doesn’t suppress competing flora; a CNA plate with oxygen is meant to differentiate Gram-positive from Gram-negative organisms and isn’t tailored for Neisseria recovery.

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