Ask a doctor on the topic of General medicine

bacteria urine

December 28, 2016 | 20,00 EUR | answered by Dr. med. Ralf Berg

Hello, I have a question. If there was nothing in the urine, so in a normal urine test. Can there still be hidden bacteria?

Dr. med. Ralf Berg

Good day,

There are two types of "normal" urine tests.

1. The urine quick test using a stick

If in this (repeat) urine test (correctly collected, midstream urine, in the morning after overnight rest) no metabolic products of bacteria (nitrite and ketones) or inflammatory cells (leukocytes) can be detected further, it can be assumed that there are no or only a few bacteria left in the urine. Especially if this is repeated after therapy, and is negative, the likelihood that there are still bacteria "hiding" is less than 10%.

2. The urine culture

If there is still suspicion that bacteria are present in small numbers in the urine, then a urine sample (additional or at the beginning as in your case) is sent to the laboratory and a urine culture is performed. The urine is incubated at 37.00 temperature. If no bacteria appear under optimal growth conditions, it can be assumed that the urine is sterile, i.e. free of bacteria. Of course, it's not 100% guaranteed. A small error rate of 3-5% undetected bacteria is always possible. I hope that was understandable.

If no bacteria were found in your follow-up examination, then this chapter is closed for you this time.

With best regards, R. C. Berg