what is nitrates in urine
Tests to detect nitrites and leukocyte esterase have become part of a routine urinalysis. Most species of bacteria that colonize in the urine cause nitrates, which are derived from dietary metabolites, to be converted to nitrites. In healthy people, both the urinary nitrite test and the leukocyte esterase (LE) tests are negative. A negative nitrite test does not necessarily mean that the urine is free of all bacteria, particularly if there are clinical symptoms, because some bacteria do not produce nitrites.