A novel sensitive nitrite reagent to be used in the clinical microbiology laboratory

We have discovered that a simple chemical compound, viz., 2-aminothiazolemethoxyimino acetic acid (ATMAA) is a specific nitrite reagent. In acidified aqueous milieu, it develops a purple or cherry-red color with sodium nitrite. A spectrophotometric method for the quantitative measurement of nitrite was developed and showed that a linear relationship exists between the intensity of red color and the concentration of nitrite. The method is sensitive, rapid and simple to perform. It was adopted for the detection, directly in the culture media, of nitrite produced from nitrate by bacterial nitrate-reductase. This new method was compared with current techniques for the species identification of microbial isolates such as mycobacteria, Gram-positive and Gram-negative bacteria, yeasts and dermatophytes.