Antibiotics are a group of medicines that are used to treat infections caused by bacteria and certain parasites. They do not work against infections that are caused by viruses – for example, the common cold or flu. Antibiotics are normally only prescribed for more serious bacterial infections – for example, pneumonia.
There are two main categories of antibiotics:
Narrow-spectrum antibiotics only kill a limited number of bacteria. They can target and kill the bacteria that are causing your illness without killing other, good bacteria. Narrow-spectrum antibiotics are usually prescribed when your doctor knows exactly what bacteria are causing your infection.
Broad-spectrum antibiotics work against many different bacteria, including some bacteria resistant to narrow-spectrum antibiotics. They are prescribed when your doctor does not know exactly what bacteria are causing your infection or when your illness is caused by several different bacteria.
What Is Antibiotic Resistance?
Resistance occurs when an antibiotic is no longer effective at killing or limiting the growth of bacteria. It can occur naturally (innate ability or genetic mutation), or can be acquired through previous exposure to an antibiotic or through contact with another organism that is resistant (transfer of resistance).
There are several ways that bacteria can resist the effects of antibiotics. Some bacteria develop the ability to neutralize the antibiotic before it can harm them, others can change the antibiotic attack site so it cannot affect the function of the bacteria, and still others can pump the antibiotic out of the cell or prevent the antibiotic from getting into the cell.
Once bacteria are resistant, the infections they cause may not be cured or controlled by antibiotic treatment, or there may be few effective drug choices. In some cases, these illnesses can lead to disability or even death.
How Do Bacteria Acquire Resistance?
The widespread use of antibiotics around the world promotes the development of antibiotic resistance. Bacteria can develop drug resistance when:
- Antibiotics are used too often or without a purpose (e.g. to treat a viral infection)
- An antibiotic is stopped too early
- The dose or schedule instructions for an antibiotic are not followed
When antibiotics are used too often or used improperly, they can kill the vulnerable bacteria in the body, but leave some of the resistant ones to grow and spread. Resistant bacteria can persist in the body and cause infection in the same person, or spread to other people and make them sick with a bacteria that is more difficult to treat.
Bacteria are very resilient. They can:
- Neutralize antibiotics before they kill the bacteria
- Change the antibiotic attack site so it cannot affect the bacteria
- Pump the antibiotic out of their cells
- Prevent the antibiotic from getting into their cells
These techniques allow resistant bacteria to thrive in the presence of antibiotics
Antibiotics are called “societal drugs” since antibiotic resistance can pass from bacterium to bacterium and resistant bacterial infections can pass from person to person. Thus, antibiotic use and antibiotic resistance and eventually effect the entire community.
When antibiotics are used in humans or animals, approximately 80-90% of the ingested antibiotics are passed through the body intact and enter the environment as waste. Further, they are no longer in therapeutic concentration, which means it’s not enough to kill the bacteria, which promotes the development of resistance.
Because antibiotic misuse is one of the causes of antibiotic resistance, it is possible to slow or reverse resistance by being more responsible about the way we use antibiotics.
The problem of antibiotic resistance is of importance because of the many factors that contribute to it, primarily the human behaviour (irregularity in completing prescribed doses, taking antibiotics where they aren’t necessary) as well as clinical practice, but the real frustration and impediment is the inability to accurately diagnose an infection resulting in incorrect prescription, or the use of broad spectrum antibiotics.
Another important contributor to this is the use of antibiotics in agriculture. Just like humans, plants are infected by bacteria, and are subsequently sprayed with antibiotics which eventually enter the environment in minute doses and eventually contribute to resistance. Antibiotics fed to animals play a similar role. Animals are generally fed broad spectrum antibiotics because the individual assessment of diseased animals is generally not feasible. This results in indiscriminate use of antibiotics where they aren’t needed, leading to subsequent development of resistance.
Why Is This An Issue?
- Infections caused by resistant micro-organisms often fail to respond to the standard treatment, resulting in prolonged illness, higher health care expenditures and a greater risk of death.
- It reduces the effectiveness of treatment; thus patients remain infectious for a longer time, increasing the risk of spreading resistant micro-organisms to others.
- The achievements of modern medicine are put at risk by antibiotic resistance. Without effective antimicrobials for prevention and treatment of infections, the success of organ transplantation, cancer chemotherapy and major surgery would be compromised.
- The growth of global trade and travel allows resistant micro-organisms to be spread rapidly to distant countries and continents through humans and food. It affects developing economies proportionally more than developed ones.
How To Counter It?
Because antibiotic misuse is one of the causes of antibiotic resistance, it is possible to slow or reverse resistance by being more responsible about the way we use antibiotics. This will help ensure that antibiotics we now have continue to be effective while researchers work to develop new antibiotics or other treatments for serious bacterial infections.
Using simple infection control practices, it is also possible to prevent many infections in the first place:
Healthcare providers can:
- Prescribe antibiotics correctly – get cultures, start the right drug promptly at the right dose for the right duration. Reassess the prescription within 48 hours based on tests and patient exam.
- Document the dose, duration and indication for every antibiotic prescription.
- Stay aware of antibiotic resistance patterns in your facility.
- Participate in and lead efforts within your hospital to improve prescribing practices.
- Follow hand hygiene and other infection control measures with every patient.
- Ask if tests will be done to make sure the right antibiotic is prescribed.
- Take antibiotics exactly as the doctor prescribes. Do not skip doses. Complete the prescribed course of treatment, even when you start feeling better.
- Only take antibiotics prescribed for you; do not share or use leftover antibiotics. Antibiotics treat specific types of infections. Taking the wrong medicine may delay correct treatment and allow bacteria to multiply.
- Do not save antibiotics for the next illness. Discard any leftover medication once the prescribed course of treatment is completed.
- Do not ask for antibiotics when your doctor thinks you do not need them. Remember antibiotics have side effects.
- Prevent infections by practising good hand hygiene and getting recommended vaccines.
We cannot outrun microbial evolution. A new broad spectrum antibiotic, if applied with current methods, would eventually meet new forms of resistance. The overall solution involves a long term path towards a more intelligent use of antibiotics enabling a future of more effective prevention, targeted treatments and smart clinical decision support systems for more accurate diagnosis.