COVID-19 Updates

Visit UC San Diego's Coronavirus portal for the latest information for the campus community.


More than 2 million people in the U.S. develop drug-resistant infections annually.

Around 90,000 people die as a result of these infections. Infections that were once easily curable with antibiotics are becoming difficult to impossible to treat, and an increasing number of people are suffering severe illness -- or dying -- as a result. Globally there are 700,000 deaths per year due to antimicrobial resistance.

About Antimicrobial Resistance (AMR)

Wonder Drugs

Antibiotics deserve much of the credit for the dramatic increase in life expectancy around the world in the 20th century. Antibiotics have saved millions of lives, prevented amputations and blindness, advanced our abilities to perform surgery, enabled new cancer treatments, and protected the lives of our military men and women. Unfortunately, it is inevitable that over time bacteria develop resistance to existing antibiotics, making infections more difficult to treat. Antibiotics and other antimicrobials are the only drugs where extensive use leads to loss of benefit.

Microbes are very small living organisms, like bacteria. Most of the time, microbes are harmless and even helpful to humans, but some cause infections and disease. Drugs that we use to treat infections caused by microbes are called antimicrobial drugs. Antimicrobials are drugs that either kill or slow the growth of microbes (bacteria, fungi, viruses, and parasites). The most commonly known antimicrobial is antibiotics, which are used to treat bacterial infections. When the microbe develops resistance, i.e. a particular drug is no longer able to kill or slow the growth of the microorganism, this is called antimicrobial resistance (AMR). In some cases, the microorganism develops resistance to more than one drug, in which case the term multidrug resistance (MDR) is used. As a result of AMR, the antimicrobial drugs become ineffective and the infections persist in the body, which in turn increases the chance of spreading the infection to others. This resistance has the potential to affect people at any stage of life, as well as healthcare, veterinary, and agriculture industries. For example, without effective antibiotics, the success of any major surgery and cancer chemotherapy is compromised. The cost of healthcare for patients with resistance infections is much higher than non-resistant infections because the illness will have a longer duration, additional testing is required, and more expensive drugs must be used. New resistance mechanisms are emerging and spreading globally, which threatens our ability to treat infectious diseases, leading to prolonged illness, disability, and death, making AMR one of the worlds' most urgent public health problems.

Antibiotic Resistance Timeline

Penicillin, discovered in 1928 by Alexander Fleming, was the first commercialized antibiotic. Ever since, the discovery of a new antibiotic is followed by the discovery of resistance to that antibiotic. Microbes are always looking for ways to survive and resist new drugs. Increasingly, microbes are sharing their resistance with one another, making it that much harder for researchers to keep up. The chart on the left shows the timeline of antibiotic drugs being introduced, and the timing of when resistance to that drug was identified. Dates are based on early reports of resistance in the literature. In the case of pan drug-resistant (PDR) Acinetobacter and Pseudomonas, the date is based on reports of health care transmission/outbreaks. Penicillin was in limited use prior to widespread population use in 1943, which could explain the identified resistance prior to full introduction of the antibiotic.


5 Things to Know about AMR

  • AMR is one of the most urgent threats to public health, a problem that is connected to the health of people, animals, and the environment.
  • AMR occurs when drugs designed to kill the microbe fail to kill. It does not mean that a person is resistant to antibiotics.
  • AMR affects all stages of life, resulting in difficult and sometimes impossible to treat infections. Many times these infections require extended hospital stays, increased follow-up visits to the doctor, and the use of costly and potentially toxic treatments.
  •  Antibiotics are great at saving human and animal lives, but they do not work on viral infections such as colds and the flu. Take antibiotics only when needed, as improper use increases the chance of resistance forming.
  • AMR has been found in all regions of the world. The ease of modern travel around the globe means resistance can also easily cross borders, and spread in places like hospitals, farms, within communities, and the environment.

How Antimicrobial Resistance Happens

Every time antimicrobial drugs are used they can lead to resistance, because the microbes develop defense strategies against them, making the drug less effective. When you get an bacterial infection, there are a lot of bacteria making you sick. Some of these bacteria are resistant to the antibiotic. When you take antibiotics, the resistant bacteria are not killed and are able to multiply and continue to make you sick. These resistant bacteria can share their defense strategy with other bacteria, spreading the resistance. The antibiotics cannot treat your infection and you could spread your infection to other people, also spreading the resistance to others.

Click here to learn about the drivers of resistance