Researchers prevent spread of flesh-eating bacteria

The attacking virus, Group A Streptococcus (GAS), is one of the most versatile human pathogens, responsible for a variety of mucosal and skin infections.It is possible that in the future, the frightening flesh-eating bacterias that are known to attack the …

The attacking virus, Group A Streptococcus (GAS), is one of the most versatile human pathogens, responsible for a variety of mucosal and skin infections.It is possible that in the future, the frightening flesh-eating bacterias that are known to attack the human body suddenly and aggressively will be effectively neutralized.

Researchers at Hebrew University and Hadassah Medical Center have found a protein that prevents the spread of this bacteria in the bodies of mice.

The attacking bacteria, Group A Streptococcus (GAS), is one of the most versatile human pathogens, responsible for a variety of mucosal and skin infections. Many, such such as “strep throat” or impetigo, are relatively mild illnesses.

But in other cases, the very same bacteria can cause other severe and even life-threatening diseases. These diseases occur when GAS get into areas of the body where bacteria are usually not found, such as the blood, muscle, or the lungs. These infections are termed “invasive GAS disease.”

In these cases, it can spread rapidly throughout the body and causes quick death in 35 percent of cases. Until now, researchers have not been able to discover what causes this bacteria to leave some people unaffected, while attacking others so aggressively.

In the last two decades there has been a global increase in the incidence of invasive GAS infections. Two of the most severe forms of invasive GAS disease are toxic shock syndrome (TSS) and necrotizing fasciitis (NF). These diseases can strike even previously healthy adults and children. TSS causes a rapid drop in blood pressure and multiorgan failure. NF – occasionally, described by the media as “the flesh-eating bacteria” – rapidly destroys skin, fat and muscles tissue. Despite prompt antibiotic treatment and surgical steps, 20% to 60% of patients with TSS and NF eventually die of the disease. The death toll of patients from other forms of invasive GAS diseases ranges between 10%-15%.

Investigators from the department of clinical microbiology at Hebrew University, Professor Emmuel Hanski and Dr. Alon Moses, discovered a way to stop the spread of the bacteria in mice, by injecting a mixture of amino acids – peptides – into the body of the mouse.

The mixture caused the white blood cells to be directed by the immune system to the place of the infection, preventing bacterial spread and the development of a sudden, lethal, systemic infection. In the mice that were injected, mortality was completely prevented.

According to the scientists, theirs is a breakthrough in two respects – both because of the fact that they succeeded in understanding the way in which the bacteria attacks the immune system, and in that they pinpointed the key material that is included in the non-violent bacterias.

“We had to ask ourselves why the white blood cells weren’t being recruited in certain cases. We discovered that a certain protein had been digesting the peptide responsible for recruiting the white blood cells,” Prof. Hanski explained to ISRAEL21c. He said that the two researchers worked with a group of investigators led by Dr. Carlos Hidalgo-Grass.

The key to their breakthrough was being able to recreate that peptide synthetically, introducing it to the mouse’s body, and putting the white blood cells to work.

“So now, using the peptides, we can obtain full protection in mice,” said Hanski.

Reaching this point has taken the scientists through five years of research. They caution that the research is still an early stage of development, and many more steps will be needed taken in order to treat humans, which may not be possible for years.

“It is still a long way until we will be able to say we’ve found a cure,” said Hanski.

But the findings definitely pave the way for development of new and efficient treatments against highly invasive life-threatening GAS infections that are urgently needed.

The Israeli researchers’ work, will appear in an upcoming issue of the prestigious medical journal, The Lancet.