ceftiofur and Salmonella-Food-Poisoning

Codex published the 'Guidelines for Risk Analysis of Foodborne Antimicrobial Resistance' to standardise the approach for evaluating risk posed by foodborne antimicrobial-resistant bacteria. One of the first steps in the guidelines is to compile a risk profile, which provides the current state of knowledge regarding a food safety issue, describes risk management options and recommends next steps. In Canada, ceftiofur/ceftriaxone-resistant Salmonella enterica subsp. enterica serovar Heidelberg from poultry was identified as an antimicrobial resistance (AMR) food safety issue. The first objective of this article was to contextualise this food safety issue, using the risk profile format of the Codex Guidelines. A second objective was to evaluate the applicability of the Codex Guidelines. This risk profile indicated that ceftiofur/ceftriaxone-resistant S. Heidelberg (CSH) was commonly isolated from poultry and was associated with severe disease in humans. Ceftiofur use in poultry hatcheries temporally mirrored the prevalence of CSH from poultry meat at retail and from people with salmonellosis. The evidence was sufficient to indicate the need for risk management options, such as restricting the use of ceftiofur in poultry. The Codex Guidelines provided a useful approach to summarise data for decision-makers to evaluate an AMR food safety issue.

Topics: Animals; Anti-Bacterial Agents; Canada; Ceftriaxone; Cephalosporins; Drug Resistance, Bacterial; Food Microbiology; Humans; Microbial Sensitivity Tests; Poultry; Practice Guidelines as Topic; Risk Assessment; Risk Management; Salmonella enterica; Salmonella Food Poisoning

The Canadian Integrated Program for Antimicrobial Resistance Surveillance describes a strong correlation (r = 0.9, p<0.0001) between ceftiofur-resistant Salmonella enterica serovar Heidelberg isolated from retail chicken and incidence of ceftiofur-resistant Salmonella serovar Heidelberg infections in humans across Canada. In Quebec, changes of ceftiofur resistance in chicken Salmonella Heidelberg and Escherichia coli isolates appear related to changing levels of ceftiofur use in hatcheries during the study period, from highest to lowest levels before and after a voluntary withdrawal, to increasing levels after reintroduction of use (62% to 7% to 20%, and 34% to 6% to 19%, respectively). These events provide evidence that ceftiofur use in chickens results in extended-spectrum cephalosporin resistance in bacteria from chicken and humans. To ensure the continued effectiveness of extended-spectrum cephalosporins for treating serious infections in humans, multidisciplinary efforts are needed to scrutinize and, where appropriate, limit use of ceftiofur in chicken production in Canada.

Topics: Animals; Anti-Bacterial Agents; Canada; Cephalosporins; Chickens; Drug Resistance, Bacterial; Humans; Meat; Microbial Sensitivity Tests; Poultry Diseases; Quebec; Salmonella enterica; Salmonella Food Poisoning; Salmonella Infections, Animal

Third-generation cephalosporin (3GC) antimicrobials are the drugs of choice for treatment of salmonellosis in children. Salmonella isolated in the USA are assayed by the National Antimicrobial Resistance Monitoring System (NARMS) for resistance to antimicrobials including first-, second- and third-generation cephalosporins. From 1999 to 2003, 34,411 Salmonella were isolated from animals in the USA, of which 10.9% were found to be resistant to ceftiofur, a 3GC used in animals, whilst only 0.3% were resistant to ceftriaxone, a 3GC used in human medicine. Ceftiofur resistance rose from 4.0% in 1999 to 18.8% in 2003. Isolates from diagnostic laboratories had higher levels of resistance (18.5%), whereas levels in isolates from on-farm (3.4%) and slaughter (7.1%) sources were lower. Animals with a higher than average proportion of resistant Salmonella included cattle (17.6%), horses (19.2%) and dogs (20.8%). Levels in turkeys (6.8%), chickens (7.1%), eggs (3.6%) and swine (4.6%) were lower. Resistance varied between Salmonella serotypes. A few serotypes had significantly high levels, e.g. S. Newport was 70.4% ceftiofur resistant. Resistance was predominantly associated with bla(CMY-2)-encoding plasmids. These data suggest that the acquisition of resistance plasmids and the spread of specific serotypes harbouring these plasmids are driving the observed resistance to ceftiofur in Salmonella animal isolates.

Topics: Animals; Anti-Bacterial Agents; Cephalosporin Resistance; Cephalosporins; Drug Resistance, Multiple, Bacterial; Humans; Plasmids; Prevalence; Salmonella enterica; Salmonella Food Poisoning; Salmonella Infections, Animal; Serotyping; United States