Antibiotics are medicines used to treat bacterial infections, but in recent years, their effectiveness has been declining. This is because bacteria can develop resistance, making infections harder to treat.
One of the most dangerous bacteria, Staphylococcus aureus (commonly known as Staph), is becoming more resistant to antibiotics. Scientists have now found that people with diabetes are at a higher risk of developing antibiotic-resistant Staph infections.
Diabetes is a long-term health condition that affects how the body controls blood sugar levels. High blood sugar weakens the immune system, making it harder to fight infections. It also creates an environment where bacteria can grow quickly.
Researchers at the University of North Carolina (UNC) School of Medicine, led by microbiologists Brian Conlon and Lance Thurlow, wanted to understand how diabetes affects the development of antibiotic resistance.
Their study, published in Science Advances, showed that antibiotic resistance emerges much faster in diabetic individuals compared to those without diabetes. This suggests that diabetes itself might be contributing to the rise of drug-resistant infections.
The Link Between Diabetes and Antibiotic Resistance
When someone has diabetes, their blood sugar levels are often too high. Bacteria like Staph use this extra sugar as fuel, helping them grow and multiply rapidly. At the same time, diabetes weakens the immune system, making it harder to kill bacteria before they become a serious infection.
As Staph bacteria multiply, random mutations occur. Some of these mutations help the bacteria survive antibiotic treatment. In people without diabetes, the immune system helps keep these mutant bacteria under control. However, in people with diabetes, the immune system is weaker, allowing these resistant bacteria to spread quickly.
Dr. Thurlow explained that once a resistant Staph strain appears in a diabetic person, it can take over the entire infection in just a few days. This rapid growth increases the risk of antibiotic-resistant infections not only in people with diabetes but also in the broader population, as resistant bacteria can spread from person to person.
Testing the Theory in the Lab
To study this effect, the researchers used mice as models for infection. They created two groups: one group of mice was made diabetic by a treatment that damaged their pancreas, while the other group remained healthy.
Both groups were then infected with Staphylococcus aureus and treated with an antibiotic called rifampicin, which is known for developing resistance quickly.
After five days, the results were clear. The antibiotic worked well in healthy mice, killing most of the bacteria. But in diabetic mice, the bacteria had evolved to resist the drug. In fact, more than 100 million antibiotic-resistant bacteria were found in each diabetic mouse, compared to almost none in the healthy ones.
To confirm their findings, the scientists repeated the experiment, but this time they introduced a small number of rifampicin-resistant bacteria at the start of the infection. In diabetic mice, these resistant bacteria quickly took over, while in healthy mice, they remained a minor part of the infection. This showed that diabetes helps antibiotic-resistant bacteria grow much faster.
Can We Prevent Antibiotic Resistance in Diabetes?
The researchers wanted to find a way to slow down this process. They tested whether lowering blood sugar levels could help prevent antibiotic resistance. When they treated diabetic mice with insulin to control their blood sugar, they found that resistant bacteria did not take over as quickly.
This suggests that keeping blood sugar at normal levels might reduce the risk of developing antibiotic-resistant infections.
Dr. Conlon emphasized that antibiotic resistance is not only about taking too many antibiotics—it is also influenced by the health of the person taking them. In diabetes, high blood sugar creates the perfect conditions for resistant bacteria to thrive.
What This Means for the Future
This study raises important concerns about the link between diabetes and antibiotic resistance. Since antibiotic-resistant bacteria can spread through the air, surfaces, and food, infections that start in people with diabetes could affect the wider community.
The researchers plan to continue their work by studying antibiotic resistance in humans with and without diabetes. They also want to investigate whether other vulnerable groups, such as cancer patients and organ transplant recipients, are also at higher risk of antibiotic resistance.
Understanding how health conditions affect antibiotic resistance could lead to better treatments and prevention strategies. For now, this research highlights the importance of controlling blood sugar in diabetes—not just for managing the disease but also for preventing dangerous drug-resistant infections.
The research findings can be found in Science Advances.
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