Assessment of animal diseases caused by bacteria resistant to antimicrobials: Poultry

Abstract

In this opinion, the antimicrobial-resistant bacteria responsible for transmissible diseases that constitute a threat to poultry health have been assessed. The assessment has been performed following a methodology based on information collected by an extensive literature review and expert judgement. Details of the methodology used for this assessment are explained in a separate opinion. A global state of play is provided for: Avibacterium (Haemophilus) paragallinarum, Bordetella avium, Clostridium perfringens, Enterococcus faecalis and Enterococcus cecorum, Erysipelothrix rhusiopathiae, Escherichia coli, Gallibacterium spp., Mycoplasma synoviae, Ornithobacterium rhinotracheale, Pasteurella multocida, Riemerella anatipestifer and Staphylococcus aureus. Among those bacteria, EFSA identified Escherichia coli, Enterococcus faecalis and Enterococcus cecorum with ≥ 66% certainty as being the most relevant antimicrobial resistant bacteria in the EU based on the available evidence. The animal health impact of these most relevant bacteria, and their eligibility for being listed and categorised within the Animal Health Law Framework, will be assessed in separate scientific opinions.

Keywords: Animal Health Law; antimicrobial resistance; extensive literature review; poultry.

Figure 1

Date of publication of the 66 studies included in the extensive literature review

Figure 2

Geographical distribution of the 66 studies included

Figure 3

Distribution of E. coli isolates per site of infection


1. SSTI: skin and soft tissue infections.

Figure 4

Escherichia coli resistance data for each included study on chickens (broiler or laying hens) sorted by continent


1. Each circle represents one study, and the size of each circle reflects how many isolates were included in the study. The colour of a circle illustrates the chicken production type and whether a study reports resistance only (R) or resistance merged with intermediate (R + I). The dashed lines indicate the weighted arithmetic mean with the same colour code as the circles. The exact percentages these lines represent are listed in Appendix E. Numbers written to the left of antibiotic names reflect the number of studies for a certain drug/continent combination.

Figure 5

Escherichia coli resistance data for each included study in chickens from mixed or unknown chicken populations sorted by continent


1. Each circle represents one study, and the size of each circle reflects how many isolates were included in the study. The colour of a circle illustrates the chicken production type and whether a study reports resistance only (R) or resistance merged with intermediate (R + I). The dashed lines indicate the weighted arithmetic mean with the same colour code as the circles. The exact percentages these lines represent are listed in Appendix E. Numbers written to the left of antibiotic names reflect the number of studies for a certain drug/continent combination.

Figure 6

Escherichia coli resistance data for each included study on poultry species other than chickens (turkey, duck, goose, quail and ostrich), sorted by country


1. Each circle represents one study, and the size of each circle reflects how many isolates were included in the study. The colour of a circle illustrates the poultry species and whether a study reports resistance only (R) or resistance merged with intermediate (R + I). The dashed lines indicate the weighted arithmetic mean with the same colour code as the circles. The exact percentages these lines represent are listed in Appendix E. Numbers written to the left of antibiotic names reflect the number of studies for a certain drug/country combination.

Figure 7

Proportion (%) of clinical poultry E. coli isolates retrieved from colibacillosis in broilers to three antimicrobials of interest reported by the FINRES‐Vet monitoring programme

Figure 8

Proportion (%) of clinical poultry E. coli isolates resistant/intermediate resistant to seven antimicrobials of interest reported by the GERM‐Vet monitoring programme

Figure 9

Proportion (%) of clinical poultry E. coli isolates retrieved from different hosts resistant to seven antimicrobials of interest reported by the RESAPATH monitoring programme

Figure 10

Proportion (%) of clinical poultry E. coli isolates retrieved from laying hens resistant to eight antimicrobials of interest reported by the SWEDRES‐Svarm monitoring programme

Figure 11

Distribution of Enterococcus spp. isolates per site of infection

Figure 12

Enterococcus spp. resistance data for each included study in chickens (broilers, layers, mixed and unknown chicken category), sorted by country


1. Each circle represents one study, and the size of each circle reflects how many isolates were included in the study. The colour of a circle illustrates the chicken production type and whether a study reports resistance only (R) or resistance merged with intermediate (R + I). The dashed lines indicate weighted arithmetic mean with the same colour code as the circles. The exact percentages these lines represent are listed in Appendix E. Numbers written to the left of antibiotic names reflect the number of studies for a certain drug/country combination.

Figure 13

Proportion (%) of clinical E. cecorum isolates retrieved from hens and broiler resistant to seven antimicrobials of interest reported by the RESAPATH monitoring programme

Figure 14

Distribution of S. aureus isolates per site of infection

Figure 15

Staphylococcus aureus resistance data for each included study on chickens (broiler, layer, mixed and unknown chicken category), sorted by country


1. Each circle represents one study, and the size of each circle reflects how many isolates were included in the study. The colour of a circle illustrates the chicken production type and whether a study reports resistance only (R) or resistance merged with intermediate (R + I). The dashed lines indicate weighted arithmetic mean with the same colour code as the circles. The exact percentages these lines represent are listed in Appendix E. Numbers written to the left of antibiotic names reflect the number of studies for a certain drug/country combination.

Figure 16

Proportion (%) of clinical S. aureus isolates retrieved from hens and broiler resistant to nine antimicrobials of interest reported by the RESAPATH monitoring programme

Figure 17

Number of clinical S. aureus isolates retrieved from chickens in England and Wales between 2015 and 2019 that were susceptible and resistant to nine antimicrobials of interest reported by the UK‐VARSS monitoring programme

Figure 18

Level of certainty for the inclusion of the selected antimicrobial resistant pathogens of poultry species among the most relevant in the EU