4.1 Detection through a One Health AMR surveillance system

The Canadian Integrated Program for AMR Surveillance (CIPARS) identified an increased prevalence, or proportion, of ceftiofur resistance among S. Heidelberg isolates from people with salmonellosis that occurred at the same time as an increased prevalence of ceftiofur resistance was detected in S. Heidelberg isolated from healthy broilers on farms and from retail chicken meat in the early 2000s (Dutil et al., 2010). These increased levels of ceftiofur resistance occurred in people, broilers and chicken meat in the same geographic area during the same time period.

  • What does this information suggest about a possible relationship between AMR in chickens and people?

  • It suggests that ceftiofur resistance in Salmonella in poultry has led to ceftiofur resistance in Salmonella in people, and the resistant bacteria or genes may have been transmitted via the food chain.

    The key pieces of evidence for a link between ceftiofur resistance in poultry and people, with transmission through the food chain were as follows:

    • There was an increased prevalence of ceftiofur resistance in salmonellae isolated from broilers, chicken meat and people suffering from salmonellosis in the same geographic area during the same time period.
    • Serotyping of the Salmonella isolates identified that ceftiofur resistance was occurring in the same Salmonella serovar, i.e. S. Heidelberg, isolated from people, broilers and retail meat.

Further evidence of this transmission of resistance from broilers to people via chicken meat was a drop in prevalence of ceftiofur resistance in S. Heidelberg isolates from infected people and a drop in prevalence in chicken meat following the Quebec poultry industry’s voluntary withdrawal of ceftiofur use in hatcheries that produce broiler chicks, during 2005–6.

  • Subsequently there was a partial reintroduction of ceftiofur use in hatcheries. Suggest what the result of this might be.

  • The incidence of resistant organisms might increase. Unfortunately, this is what happened, and resistance increased again in both people and chicken meat.

4 Detection and control of a One Health AMR problem

4.2 Emergence of ceftiofur-resistant S. Heidelberg in broilers