Increased Iron Availability Aggravates the Infection of Escherichia coli O157:H7 in Mice
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Iron plays an important role both in bacterial pathogenicity and in host defense mechanisms, which has frequently been underestimated. The primary purpose of this study was to investigate the influence of iron supplementation on the progression of bacterial infection. We used mice as an experimental model to supplement iron after Escherichia coli (E. coli) O157:H7 infection and found that iron supplementation exacerbated clinical symptoms of bacterial infection by increasing mortality and reducing body weight. Iron supplementation promoted the colonization of bacteria and enhanced inflammatory responses by increasing C-reaction protein level and the phagocytic capacity of PBMCs, as well as upregulating the expression of TNF-α and IL-1β in E. coli O157:H7-challenged mice. In vitro cell experiment confirmed that an excess of iron would enhance the growth of E. coli O157:H7 and worsen the outcome of bacterial infection. Therefore, it is certainly plausible that iron supplementation in bacterial infection may worsen rather than improve host outcome.
KeywordsIron E. coli O157:H7 Bacterial infection Iron supplementation Inflammatory responses
This study was supported by the Natural Science Foundation of Zhejiang province of China (No. LR16C170001), National Natural Science Foundation of China (No. 31572411), and National Natural Science Foundation of China (No. 31872363).
Compliance with Ethical Standards
All experimental procedures were approved by the institutional ethics committee of Zhejiang University.
Conflict of Interest
The authors declare that they have no conflict of interest.
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