• Posted August 5, 2024

Doctors May Have New Weapon Against Flesh-Eating Bacteria

MONDAY, Aug. 5, 2024 (HeathDay News) -- A new antimicrobial compound can effectively clear “flesh-eating” bacterial infections in mice, a new study shows.

The compound could be the first in an entirely new class of antibiotics, which could prove invaluable in the fight against antibiotic-resistant germs, researchers said.

“Bacterial infections of every type are an important health problem, and they are increasingly becoming multi-drug resistant and thus harder to treat,” said co-senior researcher Scott Hultgren, a professor of molecular microbiology with Washington University School of Medicine in St. Louis.

Researchers dubbed the new class of antibiotics GmPcides, for gram-positive-icide. It’s based on a type of molecule called ring-fused-2-pyridone.

GmPcides target gram-positive bacteria, which cause drug-resistant staph infections, toxic shock syndrome and other deadly infectious illnesses, researchers said.

Gram-positive bacteria tend to have thick cell walls, and can release a variety of toxins during an infection.

“All of the gram-positive bacteria that we’ve tested have been susceptible to that compound. That includes enterococci, staphylococci, streptococci, C. difficile, which are the major pathogenic bacteria types,” said co-senior researcher Michael Caparon, a professor of molecular microbiology with Washington University.

For this new study, researchers focused on Streptococcus pyrogenes, which is responsible for 500,000 deaths every year globally, including flesh-eating disease.

Mice infected with S. pyrogenes fared better following treatment with a GmPcide than untreated mice, researchers found. They had less weight loss, ulcers characteristic of the infection were smaller and they fought off the infection faster.

The GmPCide appeared to reduce the damage done by the bacteria to infected mice, and it also sped up healing of damaged skin, researchers said. However, not all animal research pans out in humans.

It’s not clear yet what makes GmPCides so effective, researchers said.

The compounds appear to have a significant effect on the cell membranes of bacteria, researchers noted. This can weaken the bacteria’s ability to spread and do damage.

“One of the jobs of a membrane is to exclude material from the outside,” Caparon said. “We know that within five to 10 minutes of treatment with GmPcide, the membranes start to become permeable and allow things that normally should be excluded to enter into the bacteria, which suggests that those membranes have been damaged.”

Researchers believe the GmPcides also appear less likely to lead to drug-resistant strains. Experiments intended to test this possibility found that few cells are able to survive the compound and pass on their advantages to a next generation of bacteria.

The research team discovered GmPcides while working on a compound to prevent bacteria from attaching to the surface of urethral catheters, which is a common cause of hospital-associated urinary tract infections.

In a happy accident, the researchers found that the new class of antibiotics was able to fight off multiple types of bacteria. Lab studies showed that GmPcides could wipe out bacteria strains in petri dishes.

Still, there’s a long way to go before GmPcides will be available hospitals and pharmacies, Caparon said.

The compounds would need to progress through animal studies and human trials before being approved by the U.S. Food and Drug Administration.

The new study was published Aug. 2 in the journal Science Advances.

More information

The U.S. Centers for Disease Control and Prevention has more about antimicrobial resistance.

SOURCE: Washington University School of Medicine, St. Louis, news release, Aug. 2, 2024