Publication Type
Journal Article
Publication Date (Issue Year)
2026
Journal Name
MDPI-Biology
Abstract
Aquaponic systems are increasingly recognized as sustainable technologies for integrated fish and vegetable production. However, concerns remain regarding the potential internalization of human pathogens into vegetables grown in these systems. This study assessed the risk of pathogen internalization in lettuce leaves grown in aquaponic systems with Nile tilapia challenged with Escherichia coli or Vibrio cholerae. The system comprised nine fish tanks, eighteen hydroponic pipes, and eighty-one lettuce plants, with tanks assigned to three treatments. Samples of water, fish gut, fish blood, and lettuce leaves were collected. Microbiological analyses included selective culture, biochemical assays, and molecular identification. Although colonies consistent with E. coli and V. cholerae were recovered on selective media, molecular sequencing identified other bacterial species, including Aeromonas sp., Aeromonas caviae, Aeromonas veronii, Enterobacter hormaechei, and Citrobacter freundii.
findings indicate that conventional culture-based methods may produce false-positive results and highlight the importance of molecular confirmation. Notably, pathogenic bacteria associated with tilapia were detected and appeared capable of disseminating through the system and internalizing into lettuce tissues. This result highlights the need for biosecurity measures, contamination monitoring, and the combined use of conventional and molecular diagnostic tools to ensure accurate pathogen detection and compliance with international food safety standards
Keywords
biochemistry assays, challenge, contamination, human pathogens, lettuce leaves
Rsif Scholar Name
Angélica Adiação Jossefa
Thematic Area
Food security and Agribusiness
Africa Host University (AHU)
Sokoine University of Agriculture (SUA), Tanzania
Funding Statement
This work was funded by the Partnership for Applied Skills in Sciences, Engineering, and Technology-Regional Scholarship and Innovation Fund (PASET-Rsif) and Carnegie Corporation of New York, awarded to AAJ (B850JN10016) and LAV (B850IG30223) for Ph.D. studies at the SACIDS Africa Centre of Excellence for Infectious Diseases, the SACIDS Foundation for One Health, Sokoine University of Agriculture, Morogoro, Tanzania
Recommended Citation
Jossefa, A. A., Viagem, L. d., Barbuio, K. M., Cerozi, B. d., & Chenyambuga, S. W. (2026). Detection of Bacterial Internalization in Lettuce (Lactuca sativa) Leaves Grown in Aquaponic Systems with Nile Tilapia (Oreochromis niloticus) Under Microbial Challenge. MDPI-Biology https://doi.org/10.3390/biology15070559