Multiple stressor effects on a model soil nematode, Caenorhabditis elegans: Combined effects of the pathogen Klebsiella pneumoniae and zinc oxide nanoparticles.

Autor: Cochran JP; Department of Plant and Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA., Unrine JM; Department of Plant and Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA; Kentucky Water Resources Research Institute, University of Kentucky, Lexington, KY, USA., Coyne M; Department of Plant and Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA., Tsyusko OV; Department of Plant and Soil Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA. Electronic address: olga.tsyusko@uky.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 Mar 20; Vol. 865, pp. 161307. Date of Electronic Publication: 2022 Dec 31.
DOI: 10.1016/j.scitotenv.2022.161307
Abstrakt: Research utilizing the model soil nematode Caenorhabditis elegans has revealed that agriculturally relevant nanoparticles (NP), such as zinc oxide NP (ZnONP), cause toxicity at low concentrations and disrupt molecular pathways of pathogen resistance. However, in most nanotoxicity assessments, model organisms are exposed to a single stressor but in nature organisms are affected by multiple sources of stress, including infections, which might exacerbate or mitigate negative effects of NP exposure. Thus, to expand our understanding of the environmental consequences of released NP, this project examined the synergistic/antagonistic effects of ZnONP on C. elegans infected with a common pathogen, Klebsiella pneumoniae. Individual exposures of C. elegans to ZnONP, zinc sulfate (Zn 2+ ions) or K. pneumoniae significantly decreased nematode reproduction compared to controls. To assess the combined stress of ZnONP and K. pneumoniae, C. elegans were exposed to equitoxic EC 30 concentrations of ZnONP (or Zn ions) and K. pneumoniae. After the combined exposure there was no decrease in reproduction. This complete elimination of reproductive toxicity was unexpected because exposures were conducted at EC 30 Zn concentrations and reproductive toxicity due to Zn should have occurred. Amelioration of the pathogen effects by Zn are partially explained by the Zn impact on the K. pneumoniae biofilm. Quantitative assessments showed that external biofilm production and estimated colony forming units (CFU) of K. pneumoniae within the nematodes were significantly decreased. Taken together, our results suggest that during the combined exposure of C. elegans to both stressors Zn in ionic or particulate form inhibits K. pneumoniae ability to colonize nematode's intestine through decreasing pathogen biofilm formation. This highlights the unpredictable nature of combined stressor effects, calling into question the utility of exposures in simplified laboratory media.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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