Tracking Antimicrobial Resistant E. coli from Pigs on Farm to Pork at Slaughter

Area of Science:

• Food safety and veterinary microbiology
• Antimicrobial resistance surveillance
• One Health initiatives

Background:

• Antimicrobial-resistant bacteria pose a significant food chain risk.
• Tracking resistance from farm animals to meat is crucial but often overlooked.
• Understanding resistance dynamics in production environments is essential for public health.

Purpose of the Study:

• To investigate the transfer and dynamics of antimicrobial resistance in Escherichia coli from pigs to meat.
• To assess antimicrobial resistance patterns and genetic markers throughout the production chain.
• To evaluate the potential for farm environments and prior pig populations to act as resistance reservoirs.

Main Methods:

• Prospective study on conventional and organic farms, tracking pigs from entry to slaughter.
• Recording antimicrobial drug usage on farms.
• Testing E. coli isolates for antimicrobial susceptibility (AMS) to 26 antibiotics and performing PCR genotyping for resistance genes.
• Analyzing 244 meat samples from 122 pigs.

Main Results:

• E. coli was detected in 22.1% of meat samples.
• Resistance to most tested antibiotics, including critically important ones, was observed.
• Significant variation in resistance patterns, from monoresistance to 16-fold multidrug resistance, was found even within single meat samples.
• High genetic similarity between on-farm and at-slaughter isolates suggests potential reservoirs in the farm environment or previous pig batches.

Conclusions:

• Antimicrobial resistance in E. coli is highly dynamic throughout the pig production chain.
• The farm environment and previous pig populations may act as reservoirs for resistant E. coli.
• The dynamic nature of resistance complicates reliable prediction of health risks based on food chain surveillance.