Contaminants in shrimp probiotics - a potential emerging threat to food security

Abstract

Probiotics are used widely in shrimp aquaculture to improve growth and prevent disease; however, for the most part their safety and efficacy remains largely unknown. Shrimp aquaculture may be vulnerable to the negative effects of unsafe and ineffective commercial products, such as the transfer of shrimp and human pathogens and antibiotic resistance genes. Shrimp health may also be adversely affected by the use of these products, potentially leading to crop yield losses. Here, we used 16S amplicon sequencing to identify the bacterial genera present in commercial shrimp probiotics and assess this against their listed product content. We identified the presence of additional genera to the labelled contents including Escherichia/Shigella and Enterococcus that may pose a risk of disease to animals and potentially humans that come into contact with these products, as well as potentially acting as carriers for virulence and antimicrobial resistance genes. Our results suggest that some commercial shrimp probiotics may be misleading to consumers and potentially unsafe for shrimp, people and the environment. We highlight the risks that contaminated commercial probiotics may pose to food security and present a series of safety and efficacy considerations to support the sustainable use of commercial shrimp probiotics.