UTI danger: Bug behind common infection can travel to the BRAIN and cause deadly abscesses, experts warn

Bacteria that causes common urinary tract infections could spread to the brain and cause a life-threatening abscess, scientists have warned.

Klebsiella pneumoniae lives in the intestines and is normally harmless, but it can cause infections if it spreads to other areas such as the urinary tract, blood or wounds.

In serious cases, it can trigger life-threatening complications including sepsis and necrotizing fasciitis, where tissue turns black and starts to die.

Now, in a new case report from Germany, scientists say they have found that the bug can ‘evolve’ and spread to the brain.

Researchers at a hospital in Cologne have said a 63-year-old woman was admitted to their unit with a urinary tract infection and abrupt vision loss in her right eye.

Scans revealed she had eye inflammation and lesions in her brain, particularly on the parietal lobe, a hub for processing sensory information.

Doctors took two urine samples and also a sample from inside her skull.

All three samples tested positive for Klebsiella pneumoniae – and two of these were an ‘evolved’ strain that was coated in a slime capsule, which researchers said made it able to dodge the immune system and proliferate in the body.

Fortunately, the infection was quickly cleared using antibiotics. 

Researchers suggested the more virulent bacteria may have evolved in the patient over one to two years, noting that two years ago the woman was treated for another urinary tract infection.

In some cases, a subpopulation of bacteria, a genetically distinct group of bacteria in a larger population, can emerge in an infection if some bacteria emerge that are better at spreading in the body or resisting antibiotics.

‘Our findings show highly virulent [bacteria] can evolve within an apparently harmless reservoir such as a urinary tract infection,’ said Dr Christoph Ernst, a microbiologist who led the research.

‘We therefore suspect that [virulent] populations are especially prevalent in multidrug-resistant infections.’

It was not clear whether the evolution of the bacteria had led to the brain infection, infections in the brain are reported in rare cases, but it had made the organism better able to evade the immune system, increasing the likelihood that it would infect other organs.

There is no evidence to suggest that the bacteria spread from the woman and is causing infections in other individuals. 

It is also unclear how the bacteria reaches the brain. One theory is that the eye acts as an entry point after the bacteria is transferred there by a contaminated hand. 

In the case report, researchers said it was an example of a new phenomenon which they called heterovirulence. In this case, a new more virulent strain emerges that is outcompeted by the main strain in one area, in this case the urinary tract, but is better able to spread and infect other areas – such as the eye – than the main strain.

The development was revealed in a case report in the New England Journal of Medicine.

About eight million urinary tract infections are recorded in the US every year, of which at least a million are thought to be caused by this bacteria.

Those who have a weakened immune system, diabetes or a recent surgery are at higher risk of infection.

Women are far more likely to suffer from a urinary tract infection than men, which researchers say is because their urethra is shorter and closer to the anus.

The bacteria is a particular problem in hospitals, where it can linger on surfaces and spread between sick patients. 

It is transmitted via touching a surface contaminated with feces and then another body part, such as the urinary tract or eye. It can also be spread via contaminated medical devices.

Warning signs of an infection include difficulty urinating or painful urination, pain in the urinary tract or fever and chills.

Anyone who suspects they have the infection is advised to consult their doctor. It is normally treated with antibiotics.