What bacteria are nitrite positive?

What bacteria are nitrite positive?

A positive result on the nitrite test is highly specific for UTI, typically because of urease-splitting organisms, such as Proteus species and, occasionally, E coli; however, it is very insensitive as a screening tool, as only 25% of patients with UTI have a positive nitrite test result.

What bacteria produces urine nitrites?

Gram-negative enteric organisms produce urinary nitrite and represent the most common uropathogens. Enterococcus, a less common uropathogen, does not produce nitrite and has a unique antibiotic resistance pattern.

What does it mean to have positive nitrite in urine?

The presence of nitrites in urine most commonly means there’s a bacterial infection in your urinary tract. This is usually called a urinary tract infection (UTI). A UTI can happen anywhere in your urinary tract, including your bladder, ureters, kidneys, and urethra.

Which bacteria reduce nitrate to nitrite UTI?

Philosophy of using this test in the diagnosis of UTI is that, large numbers of gram negative bacteria such as Entrobacteriaceae, non-glucose-fermenting gram negative rods and Moraxella catarrhalis can change urine nitrate to nitrite and then nitrite is converted to nitrogen.

What antibiotics treat nitrite positive UTI?

We recommend the use of nitrofurantoin or cephalexin in the treatment of cystitis. If LE is negative, nitrofurantoin is preferable to cephalexin. Second or third generation cephalosporins are appropriate antibiotics in the management of complicated UTI or when pyelonephritis is highly suspected.

What is the normal range of nitrite in urine?

Normally no nitrites are detected in the urine. Urinary nitrates are converted to nitrites by bacteria in the urine. A positive nitrite result signifies that bacteria capable of this conversion (eg, Escherichia coli, Klebsiella, Proteus, Enterobacter, Citrobacter, Pseudomonas) are present in the urinary tract.

What is the normal range for nitrites in urine?

Can you have nitrites in urine without infection?

If there are nitrites in your urine, it may mean that you have a UTI. However, even if no nitrites are found, you still may have an infection, because bacteria don’t always change nitrates into nitrites.

What is the principle of nitrite test?

This test is based on the principle that many (but not all) bacteria produce an enzyme called reductase, which can reduce urinary nitrates to nitrites. Clinical testing is done with a dipstick containing a reagent that reacts with nitrites to produce a pink color, thus indirectly suggesting the presence of bacteria.