Staphylococcus aureus. You may have a wound infection. In most cases, it passes without treatment, while severe cases may require antibiotics that kill the bacteria. This is the case for the majority of the population. In fact, many of us—even though we feel healthy—carry staph in the nose, which is a good, moist environment in which bacteria thrive.
However, more and more staph is becoming antibiotic-resistant (also known as multiple-resistant Staphylococcus aureus, or MRSA), and these infections can be difficult to treat.
“Antibiotic resistance is a growing problem, especially on a global level. And when you suddenly have this relatively minor infection that can’t be treated with antibiotics, the situation can become serious, sometimes life-threatening,” says Professor Niels Odem of the LEO Foundation. Cutaneous Immunology Research Center, University of Copenhagen.
Therefore, all over the world, a lot of resources are being invested in combating antibiotic resistance in Staphylococcus aureus infections, and a new study among patients with cutaneous lymphoma has yielded positive results. A new substance called endolysin has been shown to kill both resistant and non-resistant Staphylococcus aureus — without the need for antibiotics. But we’ll come back to that.
The finding is good news for patients with compromised immune systems for whom S. aureus infections can be serious and, at worst, fatal. But it also adds to the knowledge we have of other forms of therapy.
“For people with a severe disease such as cutaneous lymphoma, staphylococcus can be a huge problem, sometimes insoluble, as many develop an antibiotic-resistant form of Staphylococcus aureus,” says Nils Odem, and adds:
“This is why we are careful not to give antibiotics to everyone, because we don’t want to have to deal with more resistant bacteria. Therefore, it is important that we find new ways to treat – and not least prevent – these infections.”
The answer may be a new material
In some patients, S. aureus will exacerbate the cancer. And although antibiotics seem to be effective in some cases, they are not without their problems.
“We can say that giving high doses of antibiotics to patients with serious infections leads to an improvement in their health, skin, and symptoms of cancer. But once you stop giving them antibiotics, the symptoms and staph quickly return. Patients experience many adverse effects, and some risks of getting on resistant bacteria,” says Nils Odom.
Therefore, treating S. aureus can be challenging. At worst, cancer patients may die from an infection that doctors are unable to treat.
And this is where endolysin enters the scene, as this new substance may be part of the solution to antibiotic resistance like MRSA.
“This particular endolesin is a completely new synthetically produced enzyme that has been improved many times over and designed as a new drug,” explains Postdoc Emil Pallesen, first author of the study. He adds:
“The great thing about this enzyme is that it is designed to penetrate the wall of Staphylococcus aureus. This enables it to target and kill harmful Staphylococcus aureus and leave harmless skin bacteria unharmed.”
This is what made the researchers decide to test the new substance. They expected it to be able to kill both resistant and non-resistant staph bacteria.
“We tested the substance on skin samples from patients, and it appears to kill Staphylococcus aureus from patients. Endolesin doesn’t care whether the bacteria are resistant to antibiotics or not, because it doesn’t work in the same way as antibiotics,” says Niels Odom and adds:
“The really good news is that our lab tests have shown that endolysin not only kills Staphylococcus aureus, but also inhibits its ability to promote cancer growth.”