Thayer-Main medium is used for culture of
**Core Concept**
Thayer-Martin medium is a selective agar medium used for the isolation and cultivation of _Neisseria gonorrhoeae_ and _Neisseria meningitidis_. This medium contains antibiotics such as vancomycin, colistin, and nystatin to inhibit the growth of other bacteria and fungi.
**Why the Correct Answer is Right**
Thayer-Martin medium is specifically designed to promote the growth of _Neisseria_ species while suppressing the growth of other bacteria. The medium contains a combination of antibiotics that inhibit the growth of gram-positive bacteria, gram-negative bacteria other than _Neisseria_, and fungi. The absence of glucose in this medium also favors the growth of _Neisseria_ species, which are able to utilize other carbon sources such as maltose and lactose.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Thayer-Martin medium is not used for the culture of _Staphylococcus_ species, which are typically isolated on mannitol salt agar.
* **Option B:** This option is incorrect because _Haemophilus_ species are typically isolated on chocolate agar or blood agar, which contain factors V and X.
* **Option C:** This option is incorrect because _Pseudomonas_ species are typically isolated on Pseudomonas agar or Cetrimide agar, which contain cetrimide as a selective agent.
**Clinical Pearl / High-Yield Fact**
Thayer-Martin medium is a useful tool in the laboratory diagnosis of gonorrhea and meningococcal infections, which are both caused by _Neisseria_ species. It is essential to note that the medium should be handled in a biosafety cabinet to prevent the risk of infection.
**Correct Answer: C. _Neisseria meningitidis_**