A kind of honey from New Zealand may reverse antibiotic resistance in wound infections.
Sweet treatment for infections. I'm Bob Hirshon and this is Science Update.
Manuka honey, from New Zealand, is prized for its dark color and rich flavor. But it's also a potent antibacterial agent—one that may even reverse some kinds of antibiotic resistance. Microbiologist Rose Cooper and her colleagues at the University of Wales Institute in Cardiff have been exploring that. One study involves methicillin-resistant staph, or MRSA.
The bacterium, in the presence of honey, loses its resistance to methicillin. So it reverses that antibiotic resistance.
Another study of staph infections found that the honey slowed the formation of sticky bacterial masses called biofilms, which also contribute to antibiotic resistance. The work suggests that adding manuka honey to wound dressings could not only fight infections directly, but also help other antibiotics do their job. I'm Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
Antibiotic resistance is one of the most pressing challenges to modern medicine. Simply put, many bacteria have mutated into strains that don't respond to certain antibiotics. Hospitals, in particular, have problems with resistant bacteria, despite all the antiseptic practices that help keep those infections in check. Among the vulnerable are patients with open wounds, which can pick up infections from the surrounding environment during a hospital stay.
Using honey in medicine is hardly a new idea. Ancient Egyptian and Greek physicians used honey to treat various conditions, including wounds, sores, and rashes. Honey's natural antibiotics help to keep it from spoiling in nature. However, its antibiotic properties are very complex and poorly understood. Recently, scientists have been taking a closer look at honey's antibacterial potential for modern clinical use.
Although all honey fights bacteria, these researchers studied an especially potent variety called manuka honey. They looked at its actions against several different types of bacteria, including MRSA (methicillin-resistant Staphylococcus aureus), Pseudomonas aeruginosa, and Group A Streptococci ("strep"). All three commonly infect wounds and resist antibiotics.
Over several studies, the researchers have found that manuka honey not only attacks bacteria directly—for example, by rupturing their membranes or blocking their ability to reproduce. But also prevented the bacteria from forming biofilms: clumps of bacteria stuck together with slimy chemical secretions. That's important because biofilms protect the bacteria and allow them to grow more slowly. Since many antibiotics interfere with their growth and reproduction, growing more slowly makes those antibiotics less effective.
According to recent studies, many chronic wounds that fail to heal are infected with bacteria embedded in biofilms. Cooper's work suggests that applying honey to these wounds may block these biofilms from forming, thereby making the bacteria more vulnerable to antibiotics. They have also found that manuka honey interferes with antibiotic resistance in other ways. Furthermore, the honey helped prevent bacteria from clinging to living tissue, a critical step in the infection process. Treating bacteria with honey changes a number of proteins in the bacterial cell, including proteins associated with movement. So it could be that the honey actually makes the bacteria more mobile, and less prone to stick around.
Now try and answer these questions:
- Why is it important to find solutions to antibiotic-resistant bacteria?
- In what ways did the manuka honey fight infections directly?
- In what ways did the manuka honey interfere with antibiotic resistance?
- Why would scientists be interested in using a natural product in medicine? In what ways do you think they might apply the honey's actions to future drugs?
You may want to check out the May 20, 2011, Science Update Podcast to hear further information about this Science Update and the other programs for that week. This podcast's topics include: the soaring price of gold drives deforestation in the Amazon, colonoscopies laced with gold could help detect cancer, and honey protects against antibiotic resistance. Also: a starless starfish, and a jellyfish that navigates without a brain.