New research could help cure cystitis faster
If you’ve ever experienced the burning sensation that comes with a urinary tract infection (UTI), just hearing the word cystitis will make you wince. It’s one of the most common UTIs in women, and a course of antibiotics will usually clear it up eventually. However, finding out which bacteria are causing the problem – and which antibiotics to prescribe - can take a couple of days, during which time every trip to the loo is uncomfortable to say the least.
The current method of identifying the culprit involves growing bacterial colonies on agar plates then testing them. In the best cases this may happen in 12 hours, but it can take much longer. If the patient is prescribed the wrong antibiotic, it can make the situation worse by encouraging bacterial resistance.
New research carried out at the University Hospital Essen in Germany has found a much faster way of identifying which bacteria are responsible in individual cases. The new process, reported in the Journal of Medical Microbiology, analyses the bacteria’s proteins directly from the urine sample.
The process is called MALDI-TOF mass spectrometry (it stands for Matrix-Assisted Laser Desorption Ionization-Time of Flight). Put simply, it works by firing pulses of UV light at biological samples, which are then pushed down a tunnel by an electric force. The important bit here is that the bacteria don’t have to be grown on agar, so the MALDI-TOF method can pick out and identify the bacteria responsible for the UTI in under 30 minutes. Another advantage is that the process works with much lower levels of bacteria than the method used now.
“Identifying bacteria quickly and accurately using MALDI-TOF means treatment for UTIs can be started at an early stage and with an antibiotic targeted at the correct bacterial culprit,” said Dr Frank Mosel, who led the study.
“This should mean less patient suffering, fewer complications and a reduction in costs of both diagnosis and therapy. What’s more, the sensitivity of the test is nearly 100 times higher than the minimum clinical threshold for UTI diagnosis. This means that developing infections can be identified in routine samples before clinical symptoms appear.”
Dr Mosel went on to point out that this would be especially helpful for hospital patients who have had catheters fitted, and who may have weakened immune systems and so may be more at risk of infection.
More rapid diagnosis could also be useful for people with diabetes, who are at increased risk of UTIs because of the sugar in their urine.
There are some instances where MALDI-TOF doesn’t work well – in people who have had operations for bladder cancer for instance – because the human proteins produced mean that it is difficult to detect the bacteria in the urine samples.
However Dr Mosel believes that there is scope for this new process to be used in other areas. “This method could quite feasibly be extended to blood, cerebrospinal fluid and other bodily fluids to detect bacteria or even fungi,” he said.