- Conventional meat samples are more likely to harbor antibiotic-resistant nontyphoid Salmonella (NTS) than is antibiotic-free or organic meat.
Why this matters
- Antibiotic-resistant NTS infections are a public health concern.
- Overuse of antibiotics in animals may lead to antibiotic resistance.
- Antimicrobial susceptibility testing and whole genome sequencing were performed on 320 Salmonella isolates from 3481 samples of poultry meat from random outlets in Pennsylvania from 2008 to 2017.
- Salmonella samples were compared between conventional vs antibiotic-free or organic meats.
- NTS prevalence was significantly higher in conventional (10.2% [280/2733]) vs antibiotic-free poultry (5.3% [40/748]; P<.0001>
- Salmonella isolates from conventional meat were more likely to be resistant to 3 or more drugs (55% [154/280]) compared with antibiotic-free poultry (27.5% [11/40]; P=.0011).
- Salmonella from conventional meat were also significantly more likely to show resistance to 4 drug classes, including beta-lactams (P=.006).
- 100 Salmonella from conventional meat vs 8 isolates from antibiotic-free and organic samples harbored a gene conferring resistance to beta-lactams.
- 24.3% (68/280) of isolates from conventional meat vs 7.5% (3/40) from antibiotic-free samples contained the extended-spectrum beta-lactamase gene blaCMY-2 (P=.0145).
- These findings were presented without peer review at a conference.
- Samples were from a single area, so generalizability is unclear.