Antibiotic use on crops in low and middle-income countries based on recommendations made by agricultural advisors

Abstract

Background: Microbial resistance to medically important antibiotics is of international concern. There is considerable attention paid to the medical and veterinary use of antibiotics but there is a paucity of data on their use in global crop production. The only well documented use of antibiotics on crops is that on top fruit in the USA. Due to the absence of other data it is generally assumed that this use comprises the bulk of antibiotics applied to plants. The goal of this study was to investigate the scale and diversity of antibiotics being recommended for managing crop health problems in LMICs and the crops and types of problems for which they are selected. Methods: Plantwise is an international program which assists with the provision of agronomic advice to smallholder farmers in LMICs. Recommendations relating to the management of crop problems are stored in an international database, comprising over 400,000 records collected over 8 years. The extent of antibiotic use in crop production when grouped by the WHO regions was analysed using descriptive statistics. Results: Within our data all WHO regions of the world are using antibiotics on crop plants with the exception of Africa (no data for Europe) and the main crop on which they are used is rice. In some years, and in one region, nearly 10% of the management recommendations for rice contained an antibiotic. Eleven antibiotics are being recommended on crops (often blended together) and there is considerable regional variation as to where they are used. The problems against which antibiotics are recommended are extremely varied and we speculate that they are often used as a prophylactic spray to prevent, or control, low levels of bacterial disease. Conclusions: The data reveals that antibiotics are being recommended far more frequently and on a much greater variety of crops than previously thought. Relative to medical and veterinary use the quantities used globally are comparatively small, but this niche does provide some unique avenues by which resistance could develop in human pathogens. Results presented here have implications for those wanting to limit the spread of antibiotic resistance.