About Antibiotic Resistance

Antibiotic resistance happens when germs like bacteria and fungi develop the ability to defeat the drugs designed to kill them. That means the germs are not killed and continue to grow.

Infections caused by antibiotic-resistant germs are difficult, and sometimes impossible, to treat. In most cases, antibiotic-resistant infections require extended hospital stays, additional follow-up doctor visits, and costly and toxic alternatives.

Antibiotic resistance does not mean the body is becoming resistant to antibiotics; it is that bacteria have become resistant to the antibiotics designed to kill them.

Antibiotic Resistance Threatens Everyone


On CDC’s website, antibiotic resistance is also referred to as antimicrobial resistance or drug resistance.

Antibiotic resistance has the potential to affect people at any stage of life, as well as the healthcare, veterinary, and agriculture industries, making it one of the world’s most urgent public health problems.

Each year in the U.S., at least 2.8 million people are infected with antibiotic-resistant bacteria or fungi, and more than 35,000 people die as a result.

No one can completely avoid the risk of resistant infections, but some people are at greater risk than others (for example, people with chronic illnesses). If antibiotics lose their effectiveness, then we lose the ability to treat infections and control public health threats.

Many medical advances are dependent on the ability to fight infections using antibiotics, including joint replacements, organ transplants, cancer therapy, and treatment of chronic diseases like diabetes, asthma, and rheumatoid arthritis.

Brief History of Resistance and Antibiotics

Learn how CDC is leading efforts to combat antibiotic resistance through the Antibiotic Resistance Solutions Initiative.

Penicillin, the first commercialized antibiotic, was discovered in 1928 by Alexander Fleming. Ever since, there has been discovery and acknowledgement of resistance alongside the discovery of new antibiotics. In fact, germs will always look for ways to survive and resist new drugs. More and more, germs are sharing their resistance with one another, making it harder for us to keep up.

Select Germs Showing Resistance Over Time

Select Germs Showing Resistance Over Time
Antibiotic Approved or Released Year Released Resistant Germ Identified Year Identified
Penicillin 1941

Penicillin-resistant Staphylococcus aureus

Penicillin-resistant Streptococcus pneumoniae

Penicillinase-producing Neisseria gonorrhoeae






Vancomycin 1958
Plasmid-mediated vancomycin-resistant Enterococcus faecium

Vancomycin-resistant Staphylococcus aureus



Amphotericin B 1959 Amphotericin B-resistant Candida auris 2016
Methicillin 1960 Methicillin-resistant Staphylococcus aureus 1960
Extended-spectrum cephalosporins 1980 (Cefotaxime) Extended-spectrum beta-lactamase- producing Escherichia coli 1983
Azithromycin 1980 Azithromycin-resistant Neisseria gonorrhoeae 2011
Imipenem 1985 Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae 1996
Ciprofloxacin 1987 Ciprofloxacin-resistant Neisseria gonorrhoeae 2007
Fluconazole 1990 (FDA approved) Fluconazole-resistant Candida 1988
Caspofungin 2001 Caspofungin-resistant Candida 2004
Daptomycin 2003 Daptomycin-resistant methicillin-resistant Staphylococcus aureus 2004
Ceftazidime-avibactam 2015 Ceftazidime-avibactam-resistant KPC-producing Klebsiella pneumoniae 2015

Find more information on the development of antibiotic resistance in the latest AR Threats Report.

Fact Sheets