Thayer-Martin agar
Comparison of two culture media types used to grow Neisseria gonorrhoeae bacteria.
Known as overgrowth, note that the non-selective chocolate agar medium on the left, due to its composition, allowed for the growth of organismal colonies other than those of Neisseria gonorrhoeae, while the selective Thayer-Martin medium on the right, containing antimicrobials that inhibit the growth of organisms other than N. gonorrhoeae, shows no overgrowth, but is positive for N. gonorrhoeae bacteria.
Known as overgrowth, note that the non-selective chocolate agar medium on the left, due to its composition, allowed for the growth of organismal colonies other than those of Neisseria gonorrhoeae, while the selective Thayer-Martin medium on the right, containing antimicrobials that inhibit the growth of organisms other than N. gonorrhoeae, shows no overgrowth, but is positive for N. gonorrhoeae bacteria.
Components
It usually contains the following combination of antibiotics, called VCN inhibitor- Vancomycin, which is able to kill most Gram-positive organisms, although some Gram-positive organisms such as Lactobacillus and Pediococcus are intrinsically resistant
- Colistin, which is added to kill most Gram-negative organisms except Neisseria, although some other Gram-negative organisms such as Legionella are also resistant
- Nystatin, which can kill most fungi
- Trimethoprim, which inhibits Gram-negative organisms, especially swarming Proteus
Clinical implications
A negative culture on Thayer-Martin in a patient exhibiting symptoms of pelvic inflammatory disease most likely indicates an infection with Chlamydia trachomatis.Mnemonics: Thayer-Martin = Thigh-er Martyr = a martyr who keeps trying to get in the thighs of ppl = Gonorrhea selected (selective!) - (Reproduction okay with credits to npprep.blogspot.com)
