Urine dipstick showed nitrites, put on ab's. 3 days later, called and told no growth in culture, stop ab's. how can i have nitrites but no uti?

Nitrites in urine: False positive nitrite dipstick causes storage/dark urine: false positive results can be caused by colored substances in the urine (e.g. Phenazopyridine) and prolonged specimen storage at room temperature that allows proliferation of contaminating bacteria. If urinalysis cannot be done within two hours after collection, specimens should be refrigerated to prevent bacterial growth.

Nitrites: While the presence of nitrites in urine usually signifies the presence of a urinary tract infection, it is possible that someone misread the strip. Another possibility is that the urine specimen stood too long and some bacterial contamination took place but the number of organisms was too small to make the culture results postive. The culture is the significant result.