Antibiotic Resistance: A World at Risk

by Prasad Kanuparthi

Before going on a vacation with his family, Dr. Alexander Fleming stacked several cultured plates of Staphylococcus bacteria in a corner of his laboratory. Upon returning, he realized that a fungus contaminated one of his cultured plates and destroyed his bacterial colonies. After culturing the fungal mold and extracting the substance it produced, Dr. Fleming used it to treat various bacterial cultures, only to realize that the extracted substance was highly toxic to many bacterial colonies. He named the substance penicillin, after the mold that housed it. Penicillin’s toxic effect on multiple forms of disease-causing bacterial strains made it a global game-changing antibiotic in the fight against bacterial infections.

Since then, the story has changed. Through gradual evolutionary changes, bacterial pathogens have evolved to become resistant to many antibiotics, including penicillin. As Dr. Fleming stated in a lecture given shortly after receiving his Nobel Prize in 1954 for this very work, “The time may come when the ignorant man may easily underdose himself, and by exposing his microbes to non-lethal quantities of the drug make them resistant.” Dr. Fleming, in essence, correctly predicted the antibiotic-resistance problem we face today.

The gene for penicillin resistance existed in the bacterial population before penicillin’s inception. The emergence of a pharmaceutical industry that mass produces antibiotics has led to natural selection in favor of those bacteria possessing antibiotic resistance. The prevalence of bacterial resistance has the potential to cause uncontrollable infection in areas of poor sanitation, as these ‘superbugs’ are rapidly transmitted from person to person.

To combat the growing incidence of antibiotic-resistant bacterial infections, researchers have developed new types of antibiotics. These different classes of antibiotics are grouped according to their structure and mechanism of action. Some of them, like ampicillin and amoxicillin, are similar in action to penicillin. Others, such as the class of antibiotics termed carbapenems, inhibit various other bacterial actions.

Unfortunately, despite development of these novel antibiotics, widespread and inappropriate use have produced strains resistant even to the most potent, last-resort antibiotics. An example of a highly-dangerous bacterial infection is methicillin-resistant Staphylococcus aureus (MRSA). This deadly strain’s resistance to conventional antibiotic treatment makes it difficult to treat in the thousands of infections it causes in hospital settings each year. In fact, a sizeable portion of the patient population already possess Staphylococcus aureus bacteria on the surface of their skin. A potentially fatal infection develops when the bacteria find their way inside the patient’s body and replicate.

In addition, unnecessary prescriptions for antibiotics increase a patient’s probability of developing antibiotic-resistant bacteria (an insufficient dose encourages resistant bacterial growth). To combat the increasing misuse of antibiotics for afflictions not requiring antibiotic treatment, researchers are aiming to develop better tools to determine the source of a patient’s illness. For example, researchers at Duke University have developed a novel blood test to identify whether a patient’s respiratory symptoms are caused by viral or bacterial infection. The test utilizes the difference that viruses cause specific genes to be activated in the immune system that are not activated by bacteria. Since antibiotics have no effect on viral infections, other forms of medicine can be prescribed instead, eliminating the unnecessary use of antibiotics. This will hopefully help curb the rate at which antibiotic-resistant bacteria proliferate.

A prime example of the overuse of antibiotics is the common cold, a viral infection. Individuals with symptoms of the common cold may request or may be incorrectly prescribed antibiotics. Using antibiotics unnecessarily eliminates nonresistant bacteria and therein selects resistant bacteria to develop. This becomes a potential future threat to the patient’s health.

It is the hope of researchers at Duke that widely implementing accurate blood testing will reduce the number of improper prescriptions for antibiotics, thereby reducing the number of cases of antibiotic-resistant bacterial infections. On a global scale, as these techniques are further developed, these tools can be implemented in areas without proper health care. For example, reduced manufacturing costs, less expensive alternatives, or more information on proper sanitary habits can all reduce the spread and occurrence of these deadly pathogens. Ensuring that these vulnerable individuals do not succumb to the very real threat of antibiotic-resistant bacterial infection is crucial as bacteria continue to evolve. It is our duty to safeguard future generations from the potential pandemic of antibacterial resistance by furthering Dr. Fleming’s work by using innovation to combat infection.