Pyramid Test

Despite the fact that amidopyrine tests are used only in microbiological practice to differentiate certain types of bacteria, there are other, simpler and less labor-intensive methods that can be used for this purpose. One of these methods is the pyramidon or pyridoxine test. This technique is very simple, and the ingredients for it are available in many pharmacies or chemical supply stores.

1. The principle of the method Pyramidon or pyriton tests are based on the different effects of pyramidon (piromidon) and thyroxine (tirokseen) on group A streptococci. Streptococcus is divided into two main groups, one of which includes S. pyogenes, the other - S. faecalis. These organisms exhibit similar metabolic activities. In the presence of iodine, thyroxine and iodine kill group A bacteria. Iodine is a nutrient, while thyroxine, which is produced by various bacteria, can replace iodine. As a result, bacteria, including strains resistant to iodine, die. Pyramidon, on the other hand, is an enzyme capable of hydrolyzing various substances, including tyroxine and its metabolic products. It does not have the ability to inhibit bacterial metabolism. If the arrows glow brighter in the presence of Pyramidone, then they belong to group A streptococci. Thus, these are two enzymes, one of which has properties that inhibit the metabolism of type A bacteria, and the other breaks down and utilizes these biomolecules. Since the enzymes used in this test are absolutely specific for a particular microflora species, the results are reliable and have virtually no false positives.

Pyramidon test (or pyramidon test, amidopyrine test) is a reagent in microbiology for identifying bacteria by the ability to change the color of its colony after adding amidopyrine reagent crystals. The test was developed in 1913 by Georg Grundmann.

*Butanedioic acid (butyric acid) and pyramidone (benzoic acid salt)* form a yellow pigment, and the absence of a reaction is considered a negative test result. The presence of pigment is a positive test result. When mixing the wort with water with the addition of amidopyrines and a red dye - tetrazolium salt (p-phenylenediaminesulfonic acid), the color of the colony changes as a result of the formation of a large amount of non-enzymatic secondary product (lactic acid and yellow sediments), which makes the color of the medium more intense yellow, very quickly removing the black background. A change in colony color indicates the presence of viable bacterial dehydrogenases.