Harr Microbiology Practice Test 2025 - Free Microbiology Practice Questions and Study Guide

Chocolate agar is optimal for the growth of Neisseria gonorrhoeae because it provides essential nutrients and growth factors that support the cultivation of this fastidious organism. Chocolate agar is enriched with lysed red blood cells, which release hemoglobin and other growth factors necessary for the growth of certain bacteria, including Neisseria species. The heating process that turns blood agar into chocolate agar creates a medium that contains essential nutrients such as hemin (factor X) and nicotinamide adenine dinucleotide (NAD or factor V), both of which are crucial for the growth of Neisseria gonorrhoeae.

Neisseria gonorrhoeae requires a specific environment to thrive, and the nutrients in chocolate agar enable it to grow better than on regular media like Mueller-Hinton agar, which is primarily designed for antibiotic susceptibility testing; cystine tryptic digest agar, which is not specifically designed for Neisseria and lacks the growth factors, and nutrient agar, which may not provide adequate enrichment for fastidious organisms like gonococci. Therefore, chocolate agar is the best choice for cultivating this organism successfully in a clinical laboratory setting.