March 13 (UPI) -- Scientists are finding the use of antibodies is a promising way to treat Klebsiella pneumoniae, a bacteria strain that causes about 10 percent of all hospital-acquired infections in the United States and is usually resistant to antibiotics.
The in vitro research was conducted by scientists at the National Institute of Allergy and Infectious Diseases' Rocky Mountain Laboratories and the New Jersey Medical School-Rutgers University. Their findings were published Tuesday in mBio, the American Society for Microbiology journal. The NIAID is part of the National Institutes of Health.
The researchers plan to test this therapeutic concept in mice and determine whether it can be preventive, called active immunization, rather than only therapeutic, known as passive immunization.
The strain, which is called sequence type 258 and is normally found in the human intestines, has been resistant to carbapenem antibiotics.
The Centers for Disease Control and Prevention has labeled the bacteria as an urgent threat. Infections can cause pneumonia, bloodstream infections, wound or surgical site infections and meningitis.
The CDC said Klebsiella infections commonly occur among sick patients receiving treatment for other conditions. Most at risk are patients requiring devices that include ventilators or intravenous catheters and patients who are taking long courses of certain antibiotics. The Klebsiella bacteria can be spread through person-to-person contact, the CDC said.
One-tenth of all infections among 183 United States hospitals tested contracted the Klebsiella strain, according to a National Institutes of Health study in 2010.
"Infections caused by carbapenem-resistant K. pneumoniae are difficult to treat and mortality is high," the researchers wrote in the latest study. "New prophylactic approaches and/or therapeutic measures are needed to prevent or treat infections caused by these multidrug-resistant bacteria."
In their study, the researchers first determined that the bacterial capsule prevents immune system neutrophils from ingesting and killing the strain. Then they singled out and removed a capsule from the two most abundant capsule types of ST258 and used them to generate antibodies in rabbits.
They found that one of the antibodies enhanced the ability of white blood cells to ingest and kill bacteria.
These results are a "proof of concept" for an approach to treat these infections, the authors wrote.