Knowledge Bank

Antibiotic resistance (AR) is a critical global health issue with far-reaching implications for healthcare, agriculture, and society. Recent data from the Wang lab revealed high prevalence of antibiotic resistance in traditionally fermented foods. The consumption of foodborne antibiotic resistant bacteria, passing through the gastrointestinal (GI) track has the potential to spread and amplify the amount of AR bacteria and the encoding AR gene within our own body. The objective of this study is to examine: 1) the prevalence and abundance of antibiotic resistant bacteria in vegetables associated with different production practices, and 2) the effect of post-harvest processing methods, such as sanitizers, exemplified by an electrolyzed water wash, on mitigating these AR bacteria from raw vegetables. In this study, green onion was planted in triplicate within three distinct types of soil: traditional potting soil (control), potting soil containing poultry feces (acting as fertilizer, experiment), and potting soil containing autoclaved poultry feces (control, with nutrients of feces). Each soil type was potted with replicates. Microbial assessments of the harvested plants were then conducted by plating the green onions on Brain Heart Infusion (BHI), for gram positive bacteria, and Luria Broth (LB), for gram negative bacteria, agar plates, with and without the supplementation of representative antibiotic, tetracycline, or ampicillin. Samples of green onion washed with electrolyzed water, pH of 4.4, for 5 minutes were further assessed by plate counting for the efficacy of the treatment. Our results suggest that the electrolyzed water treatment effectively inactivated pure cultures of E. coli and Lactobacillus sp. strains by at least 4 logs, and AR bacteria from purchased retail green onions by at least 2 logs. The abundance of AR bacteria in green onions grown in potting soil with and without autoclaved feces were low, but 1-2 logs higher in green onion grown in soil supplemented with unautoclaved feces. Electrolyzed water treatment also effectively mitigated total and AR bacteria in harvested green onions. Our data illustrated the potential transmission of AR bacteria from fecal fertilizer through the plants, and the effective mitigation of microbial risks in raw vegetables by electrolyzed water. The data paved the way for interrupting the ever- escalating circle of AR transmission via the chain of host feces, plants, food, and host gut/feces by targeted mitigation.