Hans Geir Eiken

Senior Research Scientist

(+47) 996 29 966
hansgeir.eiken@nibio.no

Place
Bergen

Visiting address
Thormøhlensgate 55, 5006 Bergen

To document

Abstract

Abstract Background: Pesticides are used in greenhouse cultivation to control fungi and pests and to shape plant growth. This influences microbial communities and may increase the selective pressure for resistant species development. Antimicrobial resistance (AMR) is a growing global health challenge, and while AMR dispersal through soil and water is well studied, the role of bioaerosols as AMR vectors remains insufficiently explored. Objectives: To explore the link between chemical pesticide and the prevalence of AMR genes in aerosols from greenhouses using pesticides and those not using them. Methods: Forty-nine fullshift personal samples of inhalable dust were collected in eight greenhouses from 2021 and 2024. Five greenhouses used chemical pesticides and three did not. DNA was extracted and screened for the presence of 45 clinically relevant AMR genes using HT-qPCR. Results: Twenty of the 45 screened genes were detected. Greenhouses using pesticides showed significantly higher AMR gene levels than those not using chemicals. Several genes, particularly β-lactam and tetracycline resistance genes, occurred in high concentrations, including extreme values exceeding 60,000 gene copies/m³. This suggest that pesticide-using greenhouses may represent a greater risk for AMR dispersal. In contrast, greenhouses without chemical pesticide showed lower and more stable AMR gene levels. Factors other than pesticide application may also contribute, such as import of treated plants, soil and fertilizer materials, plant types or individual workers. Further research is needed to assess the health risks for greenhouse workers and to support the development of effective strategies for preventing and controlling AMR spread.