Experimental Treatment Targets Drug-Resistant Bacteria


07 October, 2018

You probably have heard about the Trojan Horse. Tradition says the ancient Greeks used a large wooden horse to trick enemy forces and capture the city of Troy.

Now, researchers say a similar plan of attack could help doctors destroy bacterial infections that are resistant to antibiotic drugs.

Scientists say the decreasing effectiveness of antibiotics is among the most critical problems facing modern medicine. Drug-resistant bacteria have become increasingly difficult to defeat in recent years. Scientists use the term "superbug" when talking about such bacteria.

Learning to trick superbugs

In the United States, researchers wondered if superbugs could be tricked into taking a molecule that looks like food but causes problems once inside them.

The researchers are with the University of Washington's School of Medicine. They studied a superbug called Pseudomonas aeruginosa, which causes infections in wounds, the lungs and other body parts. It can be a problem in patients whose ability to fight infection is weakened by cancer or conditions such as AIDS.

The researchers were interested in iron, an important nutrient for bacteria during infection. It causes the bacteria to grow and spread. The researchers looked for ways to limit and even stop the spread.

Microbiology professor Pradeep Singh said they came up with the idea of using a chemical mimic to deploy an antimicrobial drug to fight the bacteria. The researchers decided to use gallium, another metal, because of its similarity to iron.

The research targeted Pseudomonas aeruginosa, which causes infection in the lungs, urinary tract, wounds and elsewhere. (Singh Lab, University of Washington)
The research targeted Pseudomonas aeruginosa, which causes infection in the lungs, urinary tract, wounds and elsewhere. (Singh Lab, University of Washington)

In laboratory studies, bacteria developed resistance to gallium at low rates. The researchers found that gallium's effectiveness was increased when it was used in combination with some existing antibiotics.

These findings led the researchers to test gallium in mice and then in human patients. In the mice, the researchers found that a single dosage of gallium cured lung infections that usually killed the animals.

The human tests involved 20 patients with the lung disease cystic fibrosis. Professor Christopher Goss told VOA the gallium was slowly given to the patients in a liquid solution over five days. And while the metal cleared from the blood, it moved to the lungs, helping the patients breathe easier for up to a month.

An iron Trojan Horse

Goss described gallium as a Trojan Horse. "Gallium not only fails to nourish bacteria as iron would, it actually harms them," he said.

The results are reported in the publication Science Translational Medicine.

More research is needed to confirm gallium's safety and effectiveness as a treatment. But the study's results suggest that the plan of attack that ended the Trojan War might be helpful in the modern-day battle against superbugs.

I'm Pete Musto.

Faith Laipdus reported this story for VOANews. George Grow adapted the report for Learning English. Hai Do was the editor.

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Words in This Story

mimicv. to act like; to copy the actions of something

antimicrobial adj. related to an agent that kills microorganisms or stops their growth

dosagen. a measured amount of something, such as medicine

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