New insight may save many hospital patients

Hospitals are known for their strict hygiene and sanitation protocols to protect patients from bacteria that can be deadly for those already hospitalized with serious illnesses.

However, nearly 100,000 people die every year in US hospitals of infections they develop after being admitted, and new strains of bacteria keep emerging, seemingly out of nowhere, to sicken people in hospitals worldwide.

Researchers at Washington University School of Medicine in St. Louis have found evidence pointing to an unexpected source of such bacteria: the hospitalized patients themselves.

According to a study published in Science Translational Medicine, researchers discovered that Urinary Tract Infections (UTIs) can arise after sterile tubes, called catheters, are inserted into the urinary tract, even when no bacteria are detectable in the bladder beforehand. Such tubes are commonly used in hospitals to empty the bladders of people undergoing surgery.

In the study, using mice, inserting the tubes activated dormant Acinetobacter baumannii (A. baumannii) bacteria hidden in bladder cells, triggering them to emerge, multiply and cause UTIs.

The findings suggest that screening patients for hidden reservoirs of dangerous bacteria could supplement infection-control efforts and help prevent deadly infections.

“You could sterilize the whole hospital, and you would still have new strains of A. baumannii popping up,” says co-senior author Mario Feldman, PhD, a professor of molecular microbiology.

“Cleaning is just not enough, and nobody really knows why. This study shows that patients may be unwittingly carrying the bacteria into the hospital themselves, and that has implications for infection control.”

A. baumannii is a major threat to hospitalized people, causing many cases of UTIs in people with urinary catheters, pneumonia in people on ventilators, and bloodstream infections in people with central-line catheters into their veins.

The bacteria are notoriously resistant to a broad range of antibiotics, so such infections are challenging to treat and easily can turn deadly.

The researchers have suggested that if someone has a planned surgery and is going to be catheterized, we could try to determine whether the patient is carrying the bacteria and cure that person of it before the surgery. Ideally, that would reduce the chances of developing one of these life-threatening infections.