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Dissemination of antibiotic resistance genes is regulated by iron oxides: Insight into the influence on bacterial transformation

Authors :
Tingting Wang
Yanxing Xu
Wanting Ling
Ahmed Mosa
Si Liu
Zhipeng Lin
Hefei Wang
Xiaojie Hu
Source :
Environment International, Vol 185, Iss , Pp 108499- (2024)
Publication Year :
2024
Publisher :
Elsevier, 2024.

Abstract

The transportation of antibiotic resistance genes (ARGs) in manure-soil-plant continuums poses risks to human health. Horizontal gene transfer, particularly for bacterial transformation, is an important way for ARG dissemination. As crucial components in soils, iron oxides impacted the fates of various abiotic and biotic contaminants due to their active properties. However, whether they can influence the transformation of ARGs is unknown, which waits to be figured out to boost the assessment and control of ARG spread risks. In this study, we have investigated the effects of goethite, hematite, and magnetite (0–250 mg/L, with sizes 100 nm) on the transfer of ampicillin resistance genes to Escherichia coli cells. At lower iron oxide concentrations, the transformation of ARGs was first facilitated (transformation frequency reached up to 3.38-fold higher), but the facilitating effects gradually weakened and eventually disappeared as concentrations further increased. Particle size and iron oxide type were not the universal determinants controlling the transformation. At lower concentrations, iron oxides interacted with proteins and phospholipids in E. coli envelope structures, and induced the overgeneration of intracellular reactive oxygen species. Consequently, they led to pore formation and permeability enhancement on the cell membrane, thus promoting the transformation. The facilitation was also associated with the carrier-like effect of iron oxides for antibiotic resistance plasmids. At higher concentrations, the weakened facilitations were attributed to the aggregation of iron oxides. In this study, we highlight the crucial roles of the concentrations (contents) of iron oxides on the dissemination of ARGs in soils; this study may serve as a reference for ARG pollution control in future agricultural production.

Details

Language :
English
ISSN :
01604120
Volume :
185
Issue :
108499-
Database :
Directory of Open Access Journals
Journal :
Environment International
Publication Type :
Academic Journal
Accession number :
edsdoj.93219fb9921345349eb97d4d0c2793c9
Document Type :
article
Full Text :
https://doi.org/10.1016/j.envint.2024.108499