Plant pathogenic bacteria (PPB) cause substantial crop losses worldwide. Some well-known examples include Erwinia amylovora, causing fire blight in pear and apple orchards, Xanthomonas oryzae, damaging rice cultures, Ralstonia solanacearum, affecting tomato and potato plants, and Candidatus Liberibacter sp. (also known as Huanglongbing), which infects citrus plants. Economic losses of crops due to bacterial diseases are estimated over one billion dollars every year. In this context, farmers resort to antibiotics to fight plant bacterial diseases, in different parts of the world.

The amount of antibiotics used in plant protection is commonly considered to be relatively low, in comparison to human and animal health. However, an increasing number of studies and reports point out that the quantities effectively applied on crops are challenging to assess because there is a lack of monitoring over the world. Therefore, it was suggested that the use of antibiotics for plant health might be more widespread than previously thought.

Current initiatives collecting AMU and AMR data in plants

In the global context of the lack of information surrounding antimicrobial use (AMU) in plant health and to assess the current situation regarding antibiotic use in plant health, different initiatives have emerged, aiming to collect and gather data worldwide.

• The European Food Safety Authority (EFSA) has initiated and supported the “Plantibio” project, which aimed to reduce risk assessment uncertainties and collect data on antibiotics used for control of PPB, antibiotic resistance associated with PPB and potential alternatives to antibiotics in plant health. Outcomes of this project were gathered in a published report available at this link.
• The Centre for Agriculture and Bioscience International (CABI), has developed the “Plantwise” program to reduce crop losses due to plant health problems. For this purpose, they have established plant clinics, run by plant doctors giving practical advice for plant health.

Other initiatives are led by FAO, including surveys on antibiotic and fungicide use launched by the International Plant Protection Convention (IPPC) (IPPC is an intergovernmental treaty that develops, adopts and promotes the application of International Phytosanitary Measures -ISPMs-). Additionally, FAOSTAT collects and provides access to food and agriculture data for over 245 countries and territories, including data on quantities of antibiotic and fungicide use data, which are both included in the “fungicides” data collection.

Currently, FAO is working on the optimization of a data collection mechanism for AMU in plants that is envisioned to be implemented via the InFARM system and its IT platform. This tool will aim to collect information such as the type of antibiotics authorized in each participating country, on which crops, for which disease, the quantity applied, the surface of application or the way of application.

Additional resources on AMR and AMU in plant production and protection

To learn more about the antibiotic use and resistance in plant health, additional key scientific literature reviews and reports are listed hereunder.

• McManus, P. S. & Stockwell, V. O. Antibiotic Use for Plant Disease Management in the United States. Plant Heal. Prog. 1–8 (2001) doi:10.1094/php-2001-0327-01-rv. https://apsjournals.apsnet.org/doi/pdf/10.1094/PHP-2001-0327-01-RV
• McManus, P. S., Stockwell, V. O., Sundin, G. W. & Jones, A. L. Antibiotic use in plant agriculture. Annu. Rev. Phytopathol. 40, 443–465 (2002). https://doi.org/10.1146/annurev.phyto.40.120301.093927
• Vidaver, A. K. Uses of antimicrobials in plant agriculture. Clin. Infect. Dis. 34, S107–S110 (2002). https://doi.org/10.1086/340247
• Stockwell, V. O. & Duffy, B. Use of antibiotics in plant agriculture. Rev. sci. tech. Off. int. Epiz. 31, 199–210 (2012). https://doi.org/10.20506/rst.31.1.2104
• McManus, P. S. Does a drop in the bucket make a splash? Assessing the impact of antibiotic use on plants. Curr. Opin. Microbiol. 19, 76–82 (2014). https://doi.org/10.1016/j.mib.2014.05.013
• Sundin, G. W. & Wang, N. Antibiotic resistance in plant-pathogenic bacteria. Annu Rev Phytopathol 56, 161–180 (2018). https://doi.org/10.1146/annurev-phyto-080417-045946
• Chen, Q. L., Cui, H. L., Su, J. Q., Penuelas, J. & Zhu, Y. G. Antibiotic Resistomes in Plant Microbiomes. Trends Plant Sci. 24, 530–541 (2019). https://doi.org/10.1016/j.tplants.2019.02.010
• Haynes, E., Ramwell, C., Griffiths, T., Walker, D. & Smith, J. Review of Antibiotic Use in Crops, Associated Risk of Antimicrobial Resistance and Research Gaps. Report to Department for Environment, Food and Rural Affairs (Defra) & The Food Standards Agency (FSA) https://doi.org/10.46756/sci.fsa.vnq132 (2020) doi:10.46756/sci.fsa.vnq132.
• Taylor, P. & Reeder, R. Antibiotic use on crops in low and middle-income countries based on recommendations made by agricultural advisors. CABI Agriculture and Bioscience vol. 1 https://doi.org/10.1186/s43170-020-00001-y (2020).
• Miller, S. A., Ferreira, J. P. & Lejeune, J. T. Antimicrobial use and resistance in plant agriculture: a One Health perspective. Agric. 12, 1–27 (2022). https://doi.org/10.3390/agriculture12020289
• Verhaegen, M. et al. On the use of antibiotics to control plant pathogenic bacteria: a genetic and genomic perspective. Front. Microbiol. 14, 1221478 (2023). https://doi.org/10.3389/fmicb.2023.1221478
• Islam, T., Haque, A., Barai, H. R., Istiaq, A. & KIm, J.-J. Antibiotic Resistance in Plant Pathogenic Bacteria : Recent Data and Environmental Impact of Unchecked Use and the Potential Biocontrol Agents as an Eco-Friendly Alternative. Plants 13, 1135 (2024). https://doi.org/10.3390/plants13081135