Positive nitrite

In addition to white blood cells, bacteria and red blood cells may also be seen in the microscopic examination. If bacteria are present, the chemical test for nitrite may also be positive. Nitrite. The most accurate dipstick test is the nitrite test because bacteria must be present in the urine to convert nitrates to nitrites.

So, when your pet’s urine is nitrite-positive, it means there are bacteria present somewhere in your dog or cat’s urinary tract. No all bacteria involved in UTIs have the ability to create nitrite. So, the lack of nitrite-positive urine is not firm evidence that your pet is free of a urinary tract infection.

Invasive bacterial infection was defined as a positive blood or cerebrospinal fluid culture. Results: The dipstick urinalysis was positive for nitrite or leucocyte esterase in 766 (22.5%) of the 3401 infants we studied, and 270 (35.2%) had a dipstick test that was just positive for nitrite. Overall, 107 were diagnosed with an IBI (3.1%).

Of 12 women with a positive chlamydia test, 83% had a negative urinary nitrite. What causes false positive nitrite in urine? False-positive nitrite results may occur when urine specimens have remained at room temperature for an extended period of time, allowing bacterial contaminants to multiply and produce measurable levels of nitrites.

Because these specific bacteria can reduce nitrate to nitrite, infections with these organisms may show a positive nitrite result on the dipstick. The usefulness of the nitrite test is limited, however, as nitrite production is not associated with other urinary tract pathogens such as Pseudomonas or even enterococci. (6)

The most significant predictor from our study was preoperative positive urine nitrite. Besides, to our knowledge, this was the first study reporting that preoperative positive urine nitrite was an independent risk factor for POF after URS, RIRS or PCNL. Nitrite is not normally present in urine unless uropathogens metabolite urinary nitrate.

A positive leukocyte esterase test result is most frequently accompanied by the presence of bacteria, which produce a positive nitrite reaction. In women with dysuria (painful urination), a positive test for nitrites and leukocyte esterase are usually an indication of a urinary tract infection (probability is higher than 90%).

The detection of bacteria in urine by nitrite positive dipstick is also dependent on nitrite from the patient's diet (vegetables) and sufficient bladder incubation time. Gram-positive uropathogens do not produce nitrite reductase and therefore when infection is due to these bacteria, the dipstick will be negative for nitrite.[ 9 ]

Bladder infections are usually caused by gram-negative bacteria. These bacteria reduce nitrate to nitrite when urine remains in the bladder at least three hours. Gram-positive bacteria do not produce a positive nitrite reaction because they lack the enzyme nitrate reductase that converts urinary nitrate to nitrite.