Agricultural soils in floodplain areas face contamination from waterborne pathogens during flooding events, yet characterization of these microbial communities remains limited. Furtak and Marzec-Grządziel investigated potentially pathogenic microorganisms in cultivated soils from the Vistula River valley in Poland, comparing soil samples collected before and during simulated flooding conditions.
The researchers examined two different Fluvisols from the floodplain. At each site, the collected soil from blackcurrant-cultivated fields and an adjacent uncultivated meadow. DNA from soil samples and river water was extracted, and after extraction DNA was quantified using both a NanoDrop® 1000 Spectrophotometer and the Quantus™ Fluorometer. Using fluorometric quantification provided a complementary method for confirming DNA concentration, particularly important when dealing with environmental samples that may contain contaminants that could interfere with spectrophotometric readings. Once DNA concentrations were known, DNA samples were diluted and analyzed by Next Generation Sequencing (NGS) to identify soil microbes. Complementary identification methods using culture on selective media were also pursued.
Analysis of 22 potentially pathogenic taxa revealed that flooding significantly altered microbial community composition. In fresh, unflooded soils, the researchers detected 12 pathogenic taxa, including representatives from genera such as Acinetobacter, Legionella, Mycobacterium and Nocardia. Notably, an additional 10 pathogens were detected under simulated flooding, including families Arcobacteraceae, Enterobacteriaceae, Erwiniaceae and Yersiniaceae, as well as the genera Aliarcobacter, Pantoea, Pseudarcobacter, Serratia, Treponema and Vagococcus. The relative abundance of total selected pathogens increased after flooding, with highest abundances recorded in blackcurrant cultivation soils. Enterobacteriaceae bacteria detected in the river water multiplied in all tested soils by day 2 of flooding, suggesting direct transfer from contaminated water.
The findings indicate that agricultural soils in flood-prone areas harbor diverse pathogenic bacteria that proliferate under flooded conditions. The emergence of previously undetected pathogens may reflect selection of anaerobic and facultative anaerobic microorganisms favored by the reduced oxygen and changed pH associated with flooding. This preliminary study underscores the importance of monitoring microbial hazards in floodplain agriculture and highlights the need for further research to assess risk of pathogen transmission to crops and farmers in these vulnerable areas.
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Literature Cited
Furtak K, Marzec-Grządziel A. (2025) Microbial Hazard in Cultivated Soils Located in the Floodplains of the Vistula River Valley, Poland—Preliminary Research. Water, Air & Soil Pollution. 236,614. DOI:10.1007/s11270-025-08251-0
This article was created with the assistance of AI and edited by a human.
