Contamination of Retail Meat Samples with Multidrug-Resistant Organisms in Relation to Organic and Conventional Production and Processing: A Cross-Sectional Analysis of Data from the United States National Antimicrobial Resistance Monitoring System, 2012–2017

Abstract

Background: During food animal production, animals are exposed to, colonized by, and sometimes infected with bacteria that may contaminate animal products with susceptible and multidrug-resistant organisms (MDRO). The United States’ Organic Foods Production Act resulted in decreased antibiotic use in some animal production operations. Some studies have reported that decreased antibiotic use is associated with reduced MDRO on meat. Objectives: The aim of this study was to investigate associations of meat production and processing methods with MDRO and overall bacterial contamination of retail meats. Methods: Bacterial contamination data from 2012 to 2017 for chicken breast, ground beef, ground turkey, and pork chops were downloaded from the National Antimicrobial Resistance Monitoring System. Poisson regression models with robust variance were used to estimate associations with MDRO contamination and any contamination (adjusted for year and meat type) overall, and according to bacteria genus ( Salmonella , Campylobacter , Enterococcus , Escherichia coli ) and meat type. Results: A total of 39,349 retail meat samples were linked to 216 conventional, 123 split (conventional and organic), and three organic processing facilities. MDRO contamination was similar in conventionally produced meats processed at split vs. conventional facilities but was significantly lower in organically produced meats processed at split facilities ; 95% CI: 0.30, 0.63]. Meat processed by split vs. conventional processors had higher or similar MDRO contamination for all tested bacterial genera except Campylobacter ( ; 95% CI: 0.13, 0.64). The prevalence of any contamination was lower in samples processed at split vs. conventional facilities for aggregated samples ( ; 95% CI: 0.68, 0.73) and all meat types and bacterial genera. Discussion: Organically produced and processed retail meat samples had a significantly lower prevalence of MDRO than conventionally produced and processed samples had, whereas meat from split processors had a lower prevalence of any contamination than samples from conventional processors had. Additional studies are needed to confirm findings and clarify specific production and processing practices that might explain them. https://doi.org/10.1289/EHP7327

Impact of a Statewide Livestock Antibiotic Use Policy on Resistance in Human Urine Escherichia coli Isolates: A Synthetic Control Analysis

“…SB27 could be related to changes in ESC resistance in multiple ways; exposures may occur through dietary and environmental pathways, including living near animal production sites. 6 – 9 In 2019, third-generation cephalosporin-resistant E. coli accounted for the most worldwide deaths ( ) of any pathogen–drug combination, 38 and thus policies that may reduce resistance are critical.…”

“…48 This lengthy period to complete guidance for implementation is one potential explanation for the lack of significant change in E. coli resistant to tetracycline estimated in our study, given that tetracycline is a major animal drug and accounted for 66% of domestic sales of medically important antimicrobials in food-producing animals in 2020. 4 Because antibiotic use was not restricted outside of California and because retail meat processing and distribution is not restricted regionally, 9 a continued influx of retail meat from animals raised and processed out of state (without the SB27 restrictions) could have impacted findings. Nationwide, tetracycline use in food-producing animals dropped by 30% from 2011 to 2020 (in comparison with a 1% drop for cephalosporins) 4 ; this overall trend in tetracycline use could have masked any California-specific changes, especially when combined with nationwide food distribution.…”

“…5 Antimicrobial-resistant pathogens may spread from industrial food animal production sites to people through multiple routes, including foodborne, occupational, and environmental exposures. 6 – 9 Animals can harbor bacteria from the farm to the processing facility where they can contaminate the retail meat supply, where improperly handled or undercooked meat can lead to human infection. 10 – 12 The European Union has enacted regulations to restrict antimicrobial use in food-animal production, resulting in a 35% (biomass-adjusted) reduction in use from 2011 to 2018.…”

A Nuanced Picture: Microbial Contamination at Conventional and Split Meat Processing Facilities

“…Meat products sold in U.S. stores are less likely to be contaminated with antimicrobial-resistant organisms if they were produced and processed according to Certified Organic standards set by the U.S. Department of Agriculture. That conclusion, from the authors of a new paper published in Environmental Health Perspectives , 1 is not surprising, given evidence from prior research. 2 But according to the new study, the picture for conventionally produced meat is more nuanced.…”

Transmission of antimicrobial resistance (AMR) during animal transport

“…In summary, young age is generally a risk factor for harbouring ARB/ARGs even though this may not be valid for all species, management conditions, bacteria and AMR determinants. Conventional farms are at greater risk for housing ARB than organic or antimicrobial‐free farms (Tenhagen et al., 2018 ; Pesciaroli et al., 2020 ; Innes et al., 2021 ; Mencía‐Ares et al., 2021 ; Weinroth et al., 2022 ). In all species, antimicrobial consumption is a major driver for an increase of ARB/ARGs.…”