Bacteria, viruses, parasites and other microbes are always changing to ensure their survival. Some have adapted so well to medical treatment that drugs commonly used to prevent or kill them are no longer effective. These microbes cause drug-resistant infections. Their ability to survive medicines used against them is called antimicrobial resistance (AMR). In the case of bacterial pathogens, for which antibiotics are the most common and important drugs available for treatment, we speak of antibiotic resistance (ABR).