Which medium provides the best results for isolation of Bordetella pertussis?

• A. Bordet-Gengou
• B. Modified Skirrow's
• C. Buffered charcoal yeast extract
• D. Regan-Lowe

Answer: (D)

Isolation of Bordetella pertussis relies on a medium that both nurtures the organism and suppresses competing nasal flora. Regan-Lowe medium is designed for this purpose: it uses charcoal to absorb inhibitory substances and help keep the surface clean, provides nutrients through yeast extract, and includes antimicrobial additives to inhibit fungi and resident bacteria. This combination makes colonies of B. pertussis easier to see and recover from clinical specimens, with fewer contaminating organisms, often yielding faster and clearer results than other media.

Bordet-Gengou is an older medium that can grow pertussis but tends to be more prone to contamination and may be slower or less reliable in practice. Modified Skirrow’s medium is tailored for Campylobacter, not pertussis. Buffered charcoal yeast extract is used mainly for Legionella and related organisms, not the best choice for isolating B. pertussis.