Table G.1.

WHO (2017) and AMEG (EMA/AMEG, 2014; EMA/AMEG, 2016) categorisation of critically important antimicrobials

AMEG categorisation	WHO Highest Priority Critically Important Antimicrobials
Fluoroquinolones	Quinolones (fluoroquinolones and other quinolones)
The AMEG categorisation only includes fluoroquinolones under category 2	The recently published 5th revision of the WHO CIA list (WHO, 2017) includes all quinolones under the Highest Priority Critically Important Antimicrobials. Initial categorisations included the fluoroquinolones but not the quinolones under this category Quinolones are known to select for quinolone‐resistant Salmonella spp. and E. coli in animals. At the same time, quinolones are one of few available therapies for serious Salmonella spp. and E. coli infections. Given the high incidence of human disease due to Salmonella spp. and E. coli, the absolute number of serious cases is substantial
3rd and 4th‐generation cephalosporins	Cephalosporins (3rd‐ and higher generation)
The AMEG includes under category 2 the 3rd‐ and 4th‐generation cephalosporins. No VMP that contains cephalosporins of generations higher than the 4th‐generation is approved for food‐producing animals in the EU/EEA countries	Cephalosporins (3rd‐ and higher generation) are known to select for cephalosporin‐resistant Salmonella spp. and E. coli in animals. At the same time, 3rd‐ and higher generation cephalosporins are one of few available therapies for serious Salmonella spp. and E. coli infections in humans, particularly in children. Given the high incidence of human disease due to Salmonella spp. and E. coli, the absolute number of serious cases is substantial
Macrolides and ketolides	Macrolides and ketolides
Macrolides are included in category 1 of the AMEG (lower risk than category 2) as the risk for human and animal health was perceived as lower than that of the substances included in category 2 (AMEG report includes ketolides with macrolides in category 1; however, currently no products containing ketolides are authorised in the EU for animal use.)	Macrolides and ketolides are known to select for macrolide‐resistant Campylobacter spp. in animals, especially Campylobacter jejuni in poultry. At the same time, macrolides are one of few available therapies for serious campylobacter infections in humans. Given the high incidence of human disease due to Campylobacter spp., especially Campylobacter jejuni, the absolute number of serious cases is substantial
Glycopeptides	Glycopeptides
Glycopeptides are included in AMEG category 3 as there is no VMP that contains glycopeptides approved for food‐producing animals in the EU/EEA countries	Glycopeptides are known to select for glycopeptide‐resistant Enterococcus spp. in food animals (e.g. when avoparcin was used as a growth promoter, vancomycin‐resistant enterococci (VRE) developed in food animals and were transmitted to people). At the same time, glycopeptides are one of the few available therapies for serious enterococcal infections in humans. Given the high number of cases, the previously documented occurrence of transmission of VRE to people from food animals, and the very serious consequences of treatment failures in such cases, glycopeptides are classified as being of the highest priority
Polymyxins	Polymyxins
Due to the discovery of transferable resistance to polymyxins (e.g. colistin) use in both human and veterinary medicine must be rationalised and reserved for clinical conditions The EMA agreed that sales of colistin for use in animals should be reduced to the minimum feasible and the polymyxins were consequently added to category 2 of the AMEG classification (EMA/AMEG, 2016)	Polymyxins (e.g. colistin) are known to select for plasmid mediated polymyxin‐resistant E. coli in food animals. At the same time, intravenous polymyxins are one of few available therapies for serious Enterobacteriaceae and Pseudomonas aeruginosa multiresistant infections in people in healthcare settings in many countries, especially in seriously ill patients in critical care. Given the high incidence of human disease due to Enterobacteriaceae, the absolute number of serious cases where colistin is needed can be considered substantial

The scope of the classifications is different.

AMEG: Antimicrobial Advice Ad Hoc Expert Group; CIA: critically important antimicrobials; VMP: veterinary medicinal product.