Misuse of antibiotics leads to drug resistant bacterial populations by __________.

What are antibiotics?

  • Antibiotics are medicines used to treat or prevent infections caused by bacteria.
  • They work by inhibiting the growth of or destroying the bacteria.
  • They do this in various ways, such as destroying the bacterial cell wall or inhibiting the generation of energy from glucose within the bacterial cell.

What is antibiotic resistance?

  • Antibiotic resistance occurs when bacteria develop the ability to survive exposure to antibiotics that were designed to kill them or stop their growth.
  • Antibiotic resistant bacteria are free to grow, multiply and cause infection within the host even when exposed to antibiotics.
  • Antibiotic resistance is a major obstacle in the treatment of infectious diseases caused by bacteria.
  • The result is that certain antibiotics can no longer be used to successfully treat certain infections.
  • This significantly affects our ability to prevent and treat these diseases, increasing recovery time, the length of time people stay in hospital and death rates.
  • Understanding the mechanisms by which bacteria become resistant to antibiotics is a key task in preventing the development and spread of antibiotic resistant bacteria.
  • Understanding these mechanisms will also be important in trying to prevent bacteria developing resistance to any new antibacterial treatments that may be produced in the future.

How does antibiotic resistance occur?

  • Antibiotic resistance occurs due to changes, or mutations, in the DNA of the bacteria, or the acquisition of antibiotic resistance genes from other bacterial species through horizontal gene transfer.
  • These changes enable the bacteria to survive the effects of antibiotics designed to kill them.
  • This means that when an antibiotic is used, all the bacteria that have not undergone a mutation are killed, while the antibiotic resistant bacteria remain unaffected.
  • The antibiotic resistant bacteria are able to continue to divide and grow producing even more bacteria that are not affected by the antibiotic.
  • The existence of resistant strains of bacteria means that antibiotics or drugs designed to kill them no longer work, allowing them to spread rapidly, posing a risk to public health.
  • When this happens it is necessary for scientists to develop new antibiotics that the bacteria do not have resistance to.

Misuse of antibiotics leads to drug resistant bacterial populations by __________.

An illustration showing how a population of bacteria can develop resistance to an antibiotic.

Image credit: Genome Research Limited

Why is antibiotic resistance on the up?

  • Antibiotic resistance is a serious and growing problem in modern medicine.
  • The overuse of antibiotics in recent years has played a major role in increasing the prevalence of antibiotic resistant bacteria.
  • By frequently exposing bacteria to antibiotics it places a selection pressure on the bacteria that makes the emergence and spread of resistance much more likely.
  • Antibiotics are often prescribed for minor conditions that could easily get better on their own and patients often do not finish a course of antibiotics as prescribed by their doctors because their symptoms improve quickly.
  • To help prevent further emergence of antibiotic resistance, steps are being taken to ensure that antibiotics are only prescribed when there is a clear need for them and that they are used properly (the full course is taken).

This page was last updated on 2016-01-25

  • Things to Know
    • Things to Know About Antibiotic Resistance
    • What are bacteria and viruses?
    • What is an antibiotic?
    • What is antibiotic resistance?
  • Antibiotics Uses
    • What kinds of infections are caused by viruses and should not be treated with antibiotics?
  • Risks and Concerns
    • Why should I be concerned about antibiotic resistance?
  • Causes
    • Why are bacteria becoming resistant to antibiotics?
    • How do bacteria become resistant to antibiotics?
  • Preventions
    • How can I prevent antibiotic-resistant infections? 6 Tips
  • Antibacterial-Containing Products
    • What about antibacterial-containing products?
  • Probiotics
    • Do probiotics have a role in resistance or resistant infections?

Things to Know About Antibiotic Resistance

  • Disease-causing bacteria can cause illness. Viruses can also cause illness.
  • Antibiotics are drugs used to treat bacterial infections. Viral infections do not respond to antibiotic treatment.
  • Antibiotics have been used for a long time and are frequently prescribed. Because of this widespread use, the infectious bacteria the antibiotics were designed to target have adapted and changed, making the drugs less effective. This is antibiotic resistance.
  • Antibiotics are not effective against viral infections such as the common cold, most sore throats, and the flu. Using antibiotics when they are not needed contributes to antibiotic resistance and unwanted side effects.
  • The more antibiotics are used, the more resistant the bacteria can become because sensitive bacteria are killed, but stronger germs resist the treatment and grow and multiply. Repeated and improper use of antibiotics contributes to this process.
  • The Food and Drug Administration (FDA) states antibiotic resistance is a common public health problem because nearly all types of bacteria have become stronger and less responsive to antibiotic treatment.
  • Antibiotic resistance in children and older adults is of particular concern due to high rates of antibiotic use. Once a particular bacterium becomes resistant to an antibiotic, treating that infection becomes more difficult and in some cases, medically impossible. Untreated, bacterial infections can spread rapidly.
  • Prevention of antibiotic-resistant infections:
    • Do not take antibiotics for viral infections.
    • Complete your prescribed course of treatment exactly as instructed by your healthcare provider. Do not stop taking your medicine even if you feel better, and do not save any antibiotics for future use.
    • Do not take someone else's antibiotics because different kinds of antibiotics treat different types of bacterial infections.
  • The roles of probiotics in preventing drug-resistant infections in humans have not been established. CDC is monitoring the research on probiotics use, but cannot make any recommendations at this time.

What are bacteria and viruses?

Bacteria are single-celled organisms usually found all over the inside and outside of our bodies, except in the blood and spinal fluid.

  • Many bacteria are not harmful. In fact, some are actually beneficial. However, disease-causing bacteria trigger illnesses, such as strep throat and some ear infections.
  • Viruses are even smaller than bacteria. A virus cannot survive outside the body's cells. It causes illnesses by invading healthy cells and reproducing.

What kinds of infections are caused by viruses and should not be treated with antibiotics?

Viral infections that should not be treated with antibiotics include:

  • Colds
  • Flu
  • Most coughs and bronchitis
  • Sore throats (except for those resulting from strep throat)
  • Some ear infections

What is an antibiotic?

Antibiotics, also known as antimicrobial drugs, are drugs that fight infections caused by bacteria. Alexander Fleming discovered the first antibiotic, penicillin, in 1927. After the first use of antibiotics in the 1940s, they transformed medical care and dramatically reduced illness and death from infectious diseases.

The term "antibiotic" originally referred to a natural compound produced by a fungus or another microorganism that kills bacteria that cause disease in humans or animals. Some antibiotics may be synthetic compounds (not produced by microorganisms) that can also kill or inhibit the growth of microbes. Technically, the term "antimicrobial agent" refers to both natural and synthetic compounds; however, many people use the word "antibiotic" to refer to both.

Although antibiotics have many beneficial effects, their use has contributed to the problem of antibiotic resistance.

What is antibiotic resistance?

Antibiotic resistance is the ability of bacteria or other microbes to resist the effects of an antibiotic.

  • Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections.
  • The bacteria survive and continue to multiply causing more harm.

Why should I be concerned about antibiotic resistance?

Antibiotic resistance has been called one of the world's most pressing public health problems. Almost every type of bacteria has become stronger and less responsive to antibiotic treatment when it is really needed. These antibiotic-resistant bacteria can quickly spread to family members, schoolmates, and co-workers - threatening the community with a new strain of the infectious disease that is more difficult to cure and more expensive to treat. For this reason, antibiotic resistance is among CDC's top concerns.

Antibiotic resistance can cause significant danger and suffering for children and adults who have common infections, once easily treatable with antibiotics. Microbes can develop resistance to specific medicines. A common misconception is that a person's body becomes resistant to specific drugs. However, it is microbes, not people, that become resistant to the drugs.

If a microbe is resistant to many drugs, treating the infections it causes can become difficult or even impossible. Someone with an infection that is resistant to a certain medicine can pass that resistant infection to another person. In this way, a hard-to-treat illness can be spread from person to person. In some cases, the illness can lead to serious disability or even death.

Why are bacteria becoming resistant to antibiotics?

Antibiotic use promotes the development of antibiotic-resistant bacteria. Every time a person takes antibiotics, sensitive bacteria are killed, but resistant germs may be left to grow and multiply. Repeated and improper uses of antibiotics are the primary causes of the increase in drug-resistant bacteria.

While antibiotics should be used to treat bacterial infections, they are not effective against viral infections like the common cold, most sore throats, and the flu. The widespread use of antibiotics promotes the spread of antibiotic resistance. Smart use of antibiotics is the key to controlling the spread of resistance.

How do bacteria become resistant to antibiotics?

Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply causing more harm. Bacteria can do this through several mechanisms. Some bacteria develop the ability to neutralize the antibiotic before it can do harm, others can rapidly pump the antibiotic out, and still, others can change the antibiotic attack site so it cannot affect the function of the bacteria.

Antibiotics kill or inhibit the growth of susceptible bacteria. Sometimes one of the bacteria survives because it has the ability to neutralize or escape the effect of the antibiotic; that one bacterium can then multiply and replace all the bacteria that were killed off. Exposure to antibiotics, therefore, provides selective pressure, which makes the surviving bacteria more likely to be resistant. In addition, bacteria that were at one time susceptible to an antibiotic can acquire resistance through mutation of their genetic material or by acquiring pieces of DNA that code for the resistance properties of other bacteria. The DNA that codes for resistance can be grouped in a single easily transferable package. This means that bacteria can become resistant to many antimicrobial agents because of the transfer of one piece of DNA.

How can I prevent antibiotic-resistant infections? 6 Tips

By visiting this website, you are taking the first step to reduce your risk of getting antibiotic-resistant infections. It is important to understand that, although they are very useful drugs, antibiotics designed for bacterial infections are not useful for viral infections such as a cold, cough, or the flu. Some useful 6 tips to remember are:

  1. Talk with your healthcare provider about antibiotic resistance:
    - Ask whether an antibiotic is likely to be beneficial for your illness
    - Ask what else you can do to feel better sooner
  2. Do not take an antibiotic for a viral infection like a cold or the flu.
  3. Do not save some of your antibiotics for the next time you get sick. Discard any leftover medication once you have completed your prescribed course of treatment.
  4. Take an antibiotic exactly as the healthcare provider tells you. Do not skip doses. Complete the prescribed course of treatment even if you are feeling better. If treatment stops too soon, some bacteria may survive and re-infect.
  5. Do not take antibiotics prescribed for someone else. The antibiotic may not be appropriate for your illness. Taking the wrong medicine may delay correct treatment and allow bacteria to multiply.
  6. If your healthcare provider determines that you do not have a bacterial infection, ask about ways to help relieve your symptoms. Do not pressure your provider to prescribe an antibiotic.

What about antibacterial-containing products?

An essential part of preventing the spread of infection in the community and at home is proper hygiene. This includes hand-washing and cleaning shared items and surfaces.

Antibacterial-containing products have not been proven to prevent the spread of infection better than products that do not contain antibacterial chemicals. Although a link between antibacterial chemicals used in personal cleaning products and bacterial resistance has been shown in vitro studies (in a controlled environment), no human health consequence has been demonstrated. More studies examining resistance issues related to these products are needed.

Do probiotics have a role in resistance or resistant infections?

Probiotics are defined as microorganisms that when administered in sufficient quantities may improve health. There are a variety of probiotics that have been studied for various health benefits. Their role in preventing drug-resistant infections in humans has not been established. CDC is currently monitoring research on probiotic use, but cannot make any recommendations at this time.

From
Misuse of antibiotics leads to drug resistant bacterial populations by __________.

How has the misuse of antibiotics led to bacterial resistance?

Anytime antibiotics are used, they can contribute to antimicrobial resistance. This is because increases in antimicrobial resistance are driven by a combination of germs exposed to antibiotics, the spread of those germs, and their mechanisms of resistance.

How does bacteria become resistant to antibiotics?

Germs get rid of antibiotics using pumps in their cell walls to remove antibiotic drugs that enter the cell. Example: Some Pseudomonas aeruginosa bacteria can produce pumps to get rid of several different important antibiotic drugs, including fluoroquinolones, beta-lactams, chloramphenicol, and trimethoprim.

What are the effects of misuse of antibiotics?

Taking antibiotics too often or for the wrong reasons can change bacteria so much that antibiotics don't work against them. This is called bacterial resistance or antibiotic resistance. Some bacteria are now resistant to even the most powerful antibiotics available. Antibiotic resistance is a growing problem.

What are the main causes of drug resistant bacteria?

Misuse and overuse of antimicrobials are the main drivers in the development of drug-resistant pathogens. Lack of clean water and sanitation and inadequate infection prevention and control promotes the spread of microbes, some of which can be resistant to antimicrobial treatment.