If you've ever had a Uti before, you know what it feels like. It can be a pain to go to the doctor, give a urine sample, and wait for your results, and it can also be a pain if you don't have a urine sample.
Nearly half of women get a uti at some point in their lives. A urine sample needs to be sent to the hospital to be tested for a disease.
They will look for infections caused bybacteria that are resistant to antibiotics.
Agar plating is a technique used to do this. A small amount of urine is put on to a dish filled with a substance called agar which is kept warm overnight to allow anybacteria to grow.
The technique has been used in hospitals for over 140 years.
It's important to know what type ofbacteria are present, how many are in your urine, and which antibiotic can be used to treat them.
There are a lot of things in urine that can affect the detection ofbacteria. If you spread the urine on agar, it won't affect the growth ofbacteria.
Single cells in the sample can form blobs which are easy to count. The shape, color, size, and smell of colonies can be used to determine the type ofbacteria present.
Different types ofbacteria must be isolated and tested separately from the rest of the sample.
It's difficult to find alternatives that don't affect other urine components.
We've used the agar technique for a long time. We have a pretty good understanding of how to use the results to adjust the treatment given to someone who has an infectious disease.
The system is not perfect.
The current method of agar plating takes a long time to identify the best antibiotics to use. Patients have to be treated before the test results are known.
It's inconvenient and expensive to switch drugs after a few days. The problem of antibiotic resistance is going to get worse as a result of using more antibiotics.
The problems are helping to drive innovation in the field.
Current tests can measure antibiotic resistance in urine, but we need tests that can be done in less time.
These methods need to be portable and cheap so we can use them in the community.
This may be possible, according to recent progress.
Digital cameras can detect if a cell is growing on a small scale or in a liquid. It takes a few hours to check if an antibiotic will work, but it's still much quicker than agar plated.
Mass spectrometry is a technique that can be used to measure fragments of a sample and compare them with a database to identifybacteria.
This will speed up the testing of colonies found on agar plates.
Many of the new methods are still being researched. Agar plating is still needed for antibiotic susceptibility testing.
urine samples still need to be transported to hospital labs for analysis, because many of these technologies are too large and expensive for a GP or pharmacy.
In the future, such technologies should be able to reduce the time it takes for a person to receive a diagnosis while still being accessible. Our lab is working on this.
We've found that we can make smaller, more portable tests that are just as accurate and can be recorded with a cheap digital camera.
We are going to check these tiny tests with real patient samples.
To ensure that every case is treated quickly and effectively with the correct antibiotic, some of the new rapid UTI tests need to be used in common practice.
It will be awhile before these and other new technologies are used for diagnosis. People who think they have a UTI need to go to their GP in order to be diagnosed and given the correct medication.
Sarah Needs is a post-doctoral research associate at the University of Reading.
Under a Creative Commons license, this article is re-posted. The original article is worth a read.
All Rights Reserved © 2024
