What type of agar is recommended for differentiating Vibrio cholerae from other bacteria?

Thiosulfate-Citrate-Bile Salts-Sucrose (TCBS) agar is specifically designed for the isolation and differentiation of Vibrio species, including Vibrio cholerae. This selective medium contains components that inhibit the growth of many non-Vibrio organisms while providing an environment that supports the growth of Vibrio bacteria. Additionally, the high sucrose concentration in TCBS agar is critical because V. cholerae ferments sucrose, resulting in alkaline conditions that change the pH indicator in the agar and lead to the formation of yellow colonies. This yellow coloration is a key feature that allows for easy differentiation of V. cholerae from other bacteria that do not ferment sucrose, which may produce green or colorless colonies.

Other media listed, like Cefsulodin-irgasan-novobiocin (CIN) agar, MacConkey agar, and Columbia agar, do not possess the same selective properties for Vibrio cholerae and may not facilitate the clear differentiation required. CIN agar is primarily used for isolating Yersinia spp., while MacConkey agar is designed for Gram-negative bacteria but lacks the specificity for Vibrio. Columbia agar, being a more general-purpose medium, does not provide the selective