Science: Infections in hospitalized patients may be caused by their own bacteria

Hospitals have strict personal hygiene and sanitation protocols to protect patients from germs that rarely sicken healthy people but can be fatal to patients with serious illnesses who are already hospitalized
.
Nearly 100,000 people die each year in U.
S.
hospitals from infections
after admission.
But despite strict infection control measures, new strains of bacteria continue to emerge that seem to come out of nowhere, making people in hospitals around the world sick
.

Researchers at Washington University School of Medicine in St.
Louis have found evidence that points to an unexpected source of the bacterium: the hospitalized patients themselves
.
Through studies of mice, the researchers found that urinary tract infections (UTIs)
occurred even after a sterile catheter was inserted into the urethra, even if no bacteria were detected in the bladder beforehand.
This tube is commonly used in hospitals to empty the bladder
of a person undergoing surgery.
In mice, the researchers said, inserting a test tube activated dormant Acinetobacter baumannii (A.
b ummannii) hidden in bladder cells, prompting them to appear, multiply and cause urinary tract infections
.

The findings, published Jan.
11 in the journal Science Translational Medicine, suggest that screening patients for dangerous bacterial caches can complement infection control efforts and help prevent deadly infections
.

"You can disinfect the entire hospital, but there will still be new strains of Pseudomonas baumanni, cleaning is not enough, and no one really knows why
.
" This study suggests that patients may unknowingly carry bacteria into hospitals, which has implications for
infection control.
If someone is planning surgery and is going to have a catheter intubation, we can try to determine if the patient is carrying the bacteria and cure the person
before the surgery.
Ideally, this will reduce the chances
of getting these life-threatening infections.
”

Acinetobacter baumannii is a major threat to hospitalized patients, causing many cases of urinary tract infections in catheters, pneumonia in ventilator patients, and bloodstream infections in patients with intravenous midline catheters
.
The bacteria are known to be resistant to a wide range of antibiotics, making this infection difficult to treat and easily fatal
.

In this study, researchers investigate why people develop so many Baumannococcus urinary tract infections
after receiving a catheter.

Most urinary tract infections in healthy people are caused
by E.
coli.
Studies have shown that after a urinary tract infection appears to have been cured, E.
coli can hide in bladder cells for months and then reappear, causing another infection
.

The researchers analyzed whether Vibrio baumannii could hide inside
cells like E.
coli.
They studied mice
with urinary tract infections caused by Vibrio baumannia.
They used mice with weakened immune systems because, like humans, healthy mice can fight Vibrio baumannio.

Once the infection disappeared and no bacteria were detected in the mice's urine for two months, the researchers inserted the catheter into the mouse's urethra
using aseptic technique.
Within 24 hours, about half of the mice developed urinary tract infections
caused by strains of Acinetobacter baumannii.

"The bacteria must have been there, hidden inside the bladder cells, until the catheter was introduced
.
Catheter insertion causes inflammation, which causes the reservoir to be activated and infections to erupt
in large numbers.
”

Because Vibrio baumannii rarely causes symptoms in healthy people, many people who carry the bacteria may never know they're
infected, the researchers said.
As part of the study, researchers searched the scientific literature and found that about 2 percent of healthy people carry Vibrio baumannii
in their urine.

"I think we can safely say that a certain percentage of people carry Acinetobacter baumannii
.
As long as they are basically healthy, they do not cause any problems, but once they are hospitalized, the situation is different
.
This has changed the way we think about
infection control.
We can start thinking about how to check if a patient already has Acinetobacter before they receive certain types of treatment; How can we get rid of it; And whether other bacteria that caused deadly outbreaks in hospitals, such as Klebsiella, are also hiding in the body in the
same way.
That's what
we're grappling with now.
”