New weapon to combat resistant bacteria

The problem of hospital infection, severe disease caused by antibiotic-resistant staphylococcus bacteria, entails major costs and great suffering. Group A streptococcus bacteria, also called meat-eating killer bacteria, are another growing problem. A team of Lund scientists in Sweden has now developed a substance called Cystapep, which seems to work on bacteria that nothing else seems to be able to knock out.

If Cystapep delivers what it promises, this is nothing short of sensational. Sweden is in a better position than other countries when it comes to antibiotic resistance, but in other parts of the world dangerous strains of bacteria have developed resistance to most of the antibiotics doctors have in their arsenal, and the problem is growing worse every year in Sweden as well.

Cystapep took its name from the fact that it is a peptide (a small molecule) that is based on a larger protein called cystatin. Cystatin occurs in various forms in the body and is part of our natural protection against bacteria, fungi, and viruses. The Lund researchers Aftab Jasir and Claes Schalén, medical microbiology, and Anders Grubb, clinical chemistry, have collaborated with a team of Polish scientists to cultivate and develop the segment of cystatin C protein that has proven to provide the best protection.

“The substance has been shown to be effective against infectious staphylococcus, streptococcus, enterococcus, and pneumococcus bacteria, which include many dangerous and more or less antibiotic-resistant strains. On the other hand, the body’s own flora of bacteria is not affected, which is good news,” says Aftab Jasir.

Cystapep has also been shown to attack polio and herpes viruses. The fact that one and the same substance works against not only infectious bacteria but also viruses is unique. And the substance seems to have its very own modus operandi that bacteria cannot easily defend themselves against. The Lund team has tried to induce resistance to Cystapep by creating mutations, a procedure that is usually not very difficult, but it didn’t work at all in this case.

The researchers have just published their findings in APMIS, Acta Patologica Microbiologica Immunologica Scandinavica. They have also applied for a patent on Cystapep in order to be able to continue their research. Before transferring the patent to the pharmaceuticals industry, they want to learn more about the way the substance works, try to make it even more effective, and try out its efficacy against foreign strains of bacteria. Since Aftab Jasir and Claes Schalén are the project leader and coordinator, respectively, of a major EU project on A-streptococci, they have ready access to bacteria cultures from other countries. Clinical use of the substance may become a reality in 5 to 10 years’ time.