Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis

BackgroundSalmonella has the ability to adapt to variable environments by modulating metabolism. The Tricarboxylic Acid Cycle (TCA), as a core metabolic process, is critical for the environmental adaptation and infection process of Salmonella. Fumarate reductase FrdA is an important enzyme in the TC...

Full description

Saved in:
Bibliographic Details
Main Authors: Siping Zhu, Xinyi Sun, Hong Li, Yongmei Su, Chihuan Li, Xintong Zhu, Chao Ren, Xiaochen Liu, Yulai Dong, Qiumei Shi, Zhiqiang Zhang
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-08-01
Series:Frontiers in Microbiology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmicb.2025.1626276/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849229379857547264
author Siping Zhu
Xinyi Sun
Xinyi Sun
Hong Li
Yongmei Su
Chihuan Li
Xintong Zhu
Chao Ren
Xiaochen Liu
Yulai Dong
Qiumei Shi
Zhiqiang Zhang
author_facet Siping Zhu
Xinyi Sun
Xinyi Sun
Hong Li
Yongmei Su
Chihuan Li
Xintong Zhu
Chao Ren
Xiaochen Liu
Yulai Dong
Qiumei Shi
Zhiqiang Zhang
author_sort Siping Zhu
collection DOAJ
description BackgroundSalmonella has the ability to adapt to variable environments by modulating metabolism. The Tricarboxylic Acid Cycle (TCA), as a core metabolic process, is critical for the environmental adaptation and infection process of Salmonella. Fumarate reductase FrdA is an important enzyme in the TCA cycle, mainly catalyzing the conversion of fumarate to succinate. But the association between this enzyme and the pathogenicity of Salmonella has not yet been reported.MethodsTo determine the role of fumarate reductase FrdA in Salmonella infection, a frdA-gene deletion strain of Salmonella enteritidis (S. enteritidis) was generated in this study, and the effect of frdA knockout on the biological properties and pathogenicity of S. enteritidis were further examined. Then, the immunoprotective effect of frdA-deficient strain was determined.ResultsThe results showed that frdA deletion did not affect the growth properties of S. enteritidis but caused a significant decreased survival under environmental stress, as well as a substantial decrease in its motility and biofilm formation ability. The ΔfrdA mutant displayed apparently reduced adhesion and invasion to Caco-2 cells and markedly impaired survival and replication in RAW264.7 cells. The animal infection test showed that the frdA gene deletion could lead to a significant decrease in virulence of S. enteritidis in mice, with a 64-fold increased LD50 for mice, and ΔfrdA demonstrated significantly decreased colonization in mouse tissues and organs. The transcriptomics results showed that frdA deletion resulted in altered expression of 2163 genes in S. enteritidis, and downregulated expression of csgD and other virulence genes were confimed by qPCR. Moreover, immunization of mice with the frdA deletion strain provided promising immune protection for mice.ConclusionFumarate reductase FrdA is closely associated with pathogenicity of S. enteritidis and that is an attractive candidate target for vaccine design of Salmonella.
format Article
id doaj-art-6c9a3dccffdd4893befeb2deeb77b3cf
institution Kabale University
issn 1664-302X
language English
publishDate 2025-08-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Microbiology
spelling doaj-art-6c9a3dccffdd4893befeb2deeb77b3cf2025-08-21T14:26:55ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2025-08-011610.3389/fmicb.2025.16262761626276Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidisSiping Zhu0Xinyi Sun1Xinyi Sun2Hong Li3Yongmei Su4Chihuan Li5Xintong Zhu6Chao Ren7Xiaochen Liu8Yulai Dong9Qiumei Shi10Zhiqiang Zhang11Hebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaCollege of Computer Engineering, Zhanjiang University of Science and Technology, Zhanjiang, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaWeichang Man and Mongolian Autonomous County Xinrui Agricultural Development Ltd., Chengde, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaHebei Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science & Technology, Qinhuangdao, ChinaBackgroundSalmonella has the ability to adapt to variable environments by modulating metabolism. The Tricarboxylic Acid Cycle (TCA), as a core metabolic process, is critical for the environmental adaptation and infection process of Salmonella. Fumarate reductase FrdA is an important enzyme in the TCA cycle, mainly catalyzing the conversion of fumarate to succinate. But the association between this enzyme and the pathogenicity of Salmonella has not yet been reported.MethodsTo determine the role of fumarate reductase FrdA in Salmonella infection, a frdA-gene deletion strain of Salmonella enteritidis (S. enteritidis) was generated in this study, and the effect of frdA knockout on the biological properties and pathogenicity of S. enteritidis were further examined. Then, the immunoprotective effect of frdA-deficient strain was determined.ResultsThe results showed that frdA deletion did not affect the growth properties of S. enteritidis but caused a significant decreased survival under environmental stress, as well as a substantial decrease in its motility and biofilm formation ability. The ΔfrdA mutant displayed apparently reduced adhesion and invasion to Caco-2 cells and markedly impaired survival and replication in RAW264.7 cells. The animal infection test showed that the frdA gene deletion could lead to a significant decrease in virulence of S. enteritidis in mice, with a 64-fold increased LD50 for mice, and ΔfrdA demonstrated significantly decreased colonization in mouse tissues and organs. The transcriptomics results showed that frdA deletion resulted in altered expression of 2163 genes in S. enteritidis, and downregulated expression of csgD and other virulence genes were confimed by qPCR. Moreover, immunization of mice with the frdA deletion strain provided promising immune protection for mice.ConclusionFumarate reductase FrdA is closely associated with pathogenicity of S. enteritidis and that is an attractive candidate target for vaccine design of Salmonella.https://www.frontiersin.org/articles/10.3389/fmicb.2025.1626276/fullSalmonella enteritidisfrdAgene deletionvirulenceimmune protection
spellingShingle Siping Zhu
Xinyi Sun
Xinyi Sun
Hong Li
Yongmei Su
Chihuan Li
Xintong Zhu
Chao Ren
Xiaochen Liu
Yulai Dong
Qiumei Shi
Zhiqiang Zhang
Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
Frontiers in Microbiology
Salmonella enteritidis
frdA
gene deletion
virulence
immune protection
title Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
title_full Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
title_fullStr Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
title_full_unstemmed Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
title_short Characterization and immunoprotective efficacy of a fumarate reductase frdA mutant of Salmonella enteritidis
title_sort characterization and immunoprotective efficacy of a fumarate reductase frda mutant of salmonella enteritidis
topic Salmonella enteritidis
frdA
gene deletion
virulence
immune protection
url https://www.frontiersin.org/articles/10.3389/fmicb.2025.1626276/full
work_keys_str_mv AT sipingzhu characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT xinyisun characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT xinyisun characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT hongli characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT yongmeisu characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT chihuanli characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT xintongzhu characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT chaoren characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT xiaochenliu characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT yulaidong characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT qiumeishi characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis
AT zhiqiangzhang characterizationandimmunoprotectiveefficacyofafumaratereductasefrdamutantofsalmonellaenteritidis