Skip main navigation

AMR terminology

Antimicrobial Resistance AMR terminology
Photo of a penicillin fermentation flask
© Science museum, London
There is a lot of jargon surrounding antimicrobial resistance (AMR) so here we will cover the most commonly used terms and how we will be using them in the course.

Antimicrobial resistance (AMR) – AMR occurs when microorganisms (bacteria, viruses and fungi) change so that medications used to treat them become ineffective. This term is sometimes only used in the context of bacteria. It can also be be referred to as “drug resistance”.

Antibiotic resistance – refers specifically to resistance of bacteria to antibiotics, which are drugs used to kill or inhibit growth of bacteria.

Antibacterial resistance (ABR) – see Antibiotic resistance

Antiviral resistance – refers specifically to resistance of viruses to antivirals.

Susceptible – a microbe is “susceptible” when it is not resistant to any of the antimicrobials tested.

Multi-drug resistant (MDR) – when a microbe is resistant to multiple drugs tested. Extensively or Totally drug resistant (XDR,TDR) are additional terms used when most or all of the medically used drugs are ineffective.

Antimicrobial susceptibility testing (AST) – the screening of bacterial isolates to determine which antibiotics they are susceptible to, usually by growing the bacterium in the presence of the antibiotic. This is also called drug susceptibility testing (DST).

Antibiotic stewardship – interventions designed to promote the appropriate usage of antibiotics with an aim to reduce AMR

© Wellcome Genome Campus Advanced Courses and Scientific Conferences
This article is from the free online

Bacterial Genomes: Disease Outbreaks and Antimicrobial Resistance

Created by
FutureLearn - Learning For Life

Reach your personal and professional goals

Unlock access to hundreds of expert online courses and degrees from top universities and educators to gain accredited qualifications and professional CV-building certificates.

Join over 18 million learners to launch, switch or build upon your career, all at your own pace, across a wide range of topic areas.

Start Learning now