Researchers from McMaster University recently published an article in Nature Communications Biology that details how bacteria become resistant to antibiotics. The paper presents influential findings as the World Health Organization states about 700,000 people around the world die each year from drug resistance illnesses.

As CBC News reports, Maikel Rheinstadter, physics professor at McMaster, and Andree Khondker, an undergraduate biochemistry student, report that bacteria fight off antibiotics by stiffening their own cell membranes and changing the barrier’s electrical charge. This results in the bacteria being a less attractive target to the drugs.

Rheinstadter and his team used X-ray imaging and computer simulations to view polymyxin B—an antibiotic—interacting with the antibiotic-resistant bacteria. Normally, antibiotics have a positive charge and are attracted to bacteria which often have a negatively charged membrane. The antibiotics then puncture the bacteria’s membrane which causes the cell to die. When resistant bacteria reduce their own charge, it lowers their attractiveness to antibiotics.

What are antibiotics and bacteria?

 Bacteria are single-celled organisms and are found inside and outside of our bodies. While some bacteria are actually helpful, like the majority of bacteria living in our intestines, some disease-causing bacteria can cause illnesses such as strep throat.

An antibiotic is a substance that either kills a bacterium or inhibits its growth and replication according to Microbiology Society. Antibiotics are a type of antimicrobial and are specifically designed to circumvent bacterial infections within the body. The majority of antibiotics are produced in laboratories and are often based on compounds found in nature. They can fight against a wide range of bacteria or be highly specialised and only attack certain bacteria. They are one of the most common drugs used in medicine and are essential in surgeries such as organ transplants, appendectomies, and caesarean sections.

The Resistance

The first antibiotic discovered was penicillin—in 1928 by Alexander Fleming. Since that time, scientists and health professionals have acknowledged that bacteria will look for ways to resist new drugs. Currently, more and more bacteria are developing and sharing their resistance with other bacteria.

According to the Centres for Disease Control and Prevention, antibiotic resistance is when bacteria develop the ability to fight off the antibiotics designed to kill them. The infection caused when these antibiotic-resistant bacteria infect humans or animals is difficult to treat and may result in extended hospital stays, costly and toxic alternative medicine, and increased mortality. The longer duration spent at the hospital increases health care costs and the economic burden on families and societies. With the rate of new resistant strains rising dangerously, infections such as pneumonia, tuberculosis, blood poisoning, and foodborne diseases are becoming harder, and sometimes impossible, to treat as antibiotics become less effective.

As the World Health Organization explains, antibiotic resistance is a natural process however, misusing antibiotics in humans and animals is accelerating the process. Overuse of antibiotics enables the development of antibiotic-resistant bacteria. Meaning that each time a person takes antibiotics, non-resistant bacteria are killed, but resistant bacteria are left to grow and multiply. Poor infection prevention and control can also increase the spread of antibiotic resistance.

Antibiotics are not effective against viral infections like the common cold, flu, most sore throats, and many sinus and ear infections. Using antibiotics for these viral illnesses is another example of how overuse of antibiotics can promote the spread of antibiotic resistance.

Prevention

In order to prevent the spread of antibiotic resistance, the World Health Organization recommends only using antibiotics when prescribed by a certified health professional and never sharing or using leftover antibiotics. Viral infections should not be treated with antibiotics either.

Measures to prevent infections such as regularly washing hands, preparing food hygienically, avoiding close contact with sick people, practicing safer sex, and keeping vaccinations up to date should be actively practiced. Other important strategies centre around preparing food hygienically and include keeping raw and cooked food separate, cooking food thoroughly, storing food at safe temperatures, using safe water and raw materials, and choosing foods that have been produced without the use of antibiotics for growth promotion or disease prevention in healthy animals.

Choosing antibiotic free food products is vital as people can also be exposed to resistant bacteria from animals. While any use of antibiotics can lead to resistance, when animals are given antibiotics for growth promotion or increased feed efficiency, bacteria are exposed to low doses of these drugs over a prolonged period of time. This type of exposure to antibiotics may lead to the survival and growth of resistant bacteria. The resistant bacteria can contaminate the environment through animal stool. They can also infect meat—when the animals are slaughtered and processed—and produce when it is irrigated with contaminated water. People can then get infected with resistant bacteria when they eat the contaminated raw/undercooked meat and produce. 

Antibiotics must be used responsibly in both humans and animals because both uses enable the development and spread of resistant bacteria. Antibiotics are valuable for treating bacterial infections and reducing animal disease however, decisions about which—and how much—antibiotics can be used in humans and animals should be made after careful consideration.