Gut bacteria populations and antimicrobial-resistance pattersn change from transport to post-slaughter

The National Resistance Monitoring System (NARMS) has long been used to monitor trends in antimicrobial resistance of foodborne bacteria such as Salmonella, Campylobacter and E. coli. However, NARMS was never designed to correlate on-farm antimicrobial use with resistance trends. Consequently, researchers set out to examine the potential impact of common hog transport practices on the antimicrobial-resistance patterns of Salmonella, Campylobacter and E. coli post-slaughter. They also looked for any differences in the bacteria populations based on prevalence, serotype or pattern changes.

Researchers collected fecal samples from truckloads of 150-plus pigs upon arriving at the packing plant, and collected cecum samples post-slaughter. They then tested Salmonella, Campylobacter and E. coli isolates for resistance to certain antimicrobials.

Of the 1,163 isolates collected, 898 (77%) were resistant to at least one antimicrobial tested. However, the samples collected post-slaughter didn’t reflect the resistance patterns identified when pigs arrived at the plant and therefore are not useful for monitoring on-farm antimicrobial resistance.  Click here for more details.

Research Review: Surveillance changes needed to reflect the impact of on-farm antimicrobial use