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About Antimicrobial Resistance

About Resistance

Antibiotic / Antimicrobial resistance is the ability of microbes to resist the effects of drugs – that is, the germs are not killed, and their growth is not stopped. Although some people are at greater risk than others, no one can completely avoid the risk of antibiotic-resistant infections. Infections with resistant organisms are difficult to treat, requiring costly and sometimes toxic alternatives.

Bacteria will inevitably find ways of resisting the antibiotics developed by humans, which is why aggressive action is needed now to keep new resistance from developing and to prevent the resistance that already exists from spreading.

Explanation of Bacteria and Other Microbes

Microbes are organisms too small for the eye to see and are found everywhere on Earth.  There are many types of microbes: bacteria, viruses, fungi, and parasites.  While most microbes are harmless and even beneficial to living organisms, some can cause disease among humans, other animals, and plants.  These disease-causing microbes are called pathogens; sometimes they are referred to as “germs” or “bugs.”  All types of microbes have the ability to develop resistance to the drugs created to destroy them, becoming drug-resistant organisms.


Examples of Diesease-Causing Microbes Image

How Resistance Happens

Simply using antibiotics creates resistance.  These drugs should only be used to manage infections.

Trends in Drug Resistance

  • Antibiotics are among the most commonly prescribed drugs used in human medicine and can be lifesaving drugs.  However, up to 50% of the time antibiotics are not optimally prescribed, often done so when not needed, incorrect dosing or duration.
  • The germs that contaminate food can become resistant because of the use of antibiotics in people and in food animals.  For some germs, like the bacteria Salmonella and Campylobacter, it is primarily the use of antibiotics in food animals that increases resistance.  Because of the link the between antibiotic use in food-producing animals and the occurrence of antibiotic-resistant infections in humans, antibiotics that are medically important to treating infections in humans should be used in food-producing animals only under veterinary oversight and only to manage and treat infectious disease, not to promote growth.
  • The other major factor in the growth of antibiotic resistance is spread of the resistant strains of bacteria from person to person, or from the non-human sources in the environment.

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How Antimicrobial Resistance happens image


Examples of how Antimicrobial Resistance Spread image

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Resistance in the United States


Resistance in the United States image

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Four Core Actions to Fight Resistance


Preventing infections image


Tracking infections image


Improving antibotic prescribing image


Developing new drugs and diagnostic test

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Brief History of Antibiotics

Humans developed antimicrobials to destroy disease-causing microbes.  The most commonly known antimicrobials are antibiotics, which target bacteria.  Other forms of antimicrobials are antivirals, antifungals, and antiparasitics.

Penicillin, the first commercialized antibiotic, was discovered in 1928 by Alexander Fleming.  While it wasn’t distributed among the general public until 1945, it was widely used in World War II for surgical and wound infections among the Allied Forces.  It was hailed as a “miracle drug” and a future free of infectious diseases was considered.  When Fleming won the Nobel Prize for his discovery, he warned of bacteria becoming resistant to penicillin in his acceptance speech.


Developing Reistance chart

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Questions and Answers

What is an antibiotic?

An antibiotic is a type of drug that kills or stops the growth of bacteria.  Examples include penicillin and ciprofloxacin.

What is an antimicrobial?

An antimicrobial is a type of drug that kills or stops the growth of microbes, such as bacteria, viruses, fungi, and parasites.

What is antibiotic resistance?

Antibiotic resistance is the ability of bacteria to resist the effects of an antibiotic – that is, the bacteria are not killed, and their growth is not stopped.  Resistant bacteria survive exposure to the antibiotic and continue to multiply in the body, potentially causing more harm and spreading to other animals or people.

What effects do resistant infections have on people?

Some resistant infections cause severe illness.  People with these infections:

• May require increased recovery time,
• Tend to incur increased medical expenses, and/or
• May die from the infection.

What are some other consequences of antibiotic resistance?

Physicians have to recommend second- or third-choice drugs for treatment when the bacteria that cause infections are resistant to the drug of choice and this drug doesn’t work. But the alternative drugs might be less effective, more toxic, and more expensive.  Preserving the effectiveness of antibiotics is vital to protecting human and animal health.

How do resistant bacteria in food animals end up in our food?

All animals carry bacteria in their intestines.  Giving antibiotics will kill many bacteria, but resistant bacteria can survive and multiply.

  • When food animals are slaughtered and processed, these resistant bacteria can contaminate the meat or other animal products.
  • These bacteria can also get into the environment when an animal poops and may spread to produce that is irrigated with contaminated water.

How do people get infections with resistant bacteria from animals?

There are several direct routes by which people can get antibiotic-resistant bacteria that develop in industrial food animal production:

  • Improperly handling or consuming inadequately cooked contaminated meat.
  • Contact with infected farm workers or meat processors, or perhaps their families, doctors and others with whom they interact.
  • Drinking contaminated surface or ground water and eating contaminated crops.
  • Contacting air that is vented from concentrated animal housing or is released during animal transport.

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