Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia
IntroductionThe rpoE-chrR pair is a regulatory system used by photosynthetic microorganisms to overcome singlet oxygen stress. rpoE and chrR encode the sigma factor σE and anti-sigma factor ChrR, respectively. Stenotrophomonas maltophilia, an opportunistic pathogen, is a multidrug-resistant gram-neg...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2025-02-01
|
| Series: | Frontiers in Cellular and Infection Microbiology |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fcimb.2025.1492008/full |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832542288834723840 |
|---|---|
| author | Ren-Hsuan Ku Hsu-Feng Lu Li-Hua Li Li-Hua Li Ting-Yu Yeh Yi-Tsung Lin Yi-Tsung Lin Tsuey-Ching Yang |
| author_facet | Ren-Hsuan Ku Hsu-Feng Lu Li-Hua Li Li-Hua Li Ting-Yu Yeh Yi-Tsung Lin Yi-Tsung Lin Tsuey-Ching Yang |
| author_sort | Ren-Hsuan Ku |
| collection | DOAJ |
| description | IntroductionThe rpoE-chrR pair is a regulatory system used by photosynthetic microorganisms to overcome singlet oxygen stress. rpoE and chrR encode the sigma factor σE and anti-sigma factor ChrR, respectively. Stenotrophomonas maltophilia, an opportunistic pathogen, is a multidrug-resistant gram-negative bacterium. Although it is not a photosynthetic microorganism, a rpoE-chrR homolog (smlt2377-smlt2378) was found in the S. maltophilia genome. In this study, we aimed to assess the significance of σEc-ChrR pair in oxidative stress alleviation and antibiotic susceptibility of S. maltophilia KJ.MethodsReverse transcription-polymerase chain reaction was used to validate the presence of operon. The contribution of rpoEc-chrR-chrA operon to oxidative stress alleviation and antibiotic susceptibility was evaluated using mutant constructs and stress-tolerance assays. RNA-seq transcriptome assay of wild-type KJ, KJΔChrR (chrR mutant), and KJΔChrRΔRpoEc (chrR/rpoEc double mutant) was performed to reveal the σEc regulon.ResultsThe rpoEc-chrR pair and downstream chrA formed an operon. Inactivation of chrR upregulated the expression of rpoEc-chrR-chrA operon in an σEc- and ChrA-dependent manner. σEc activation contributed to superoxide tolerance and increased β-lactam susceptibility but did not affect the tolerance to singlet oxygen and hydrogen peroxide. Transcriptome analysis revealed that expression of the nine-gene cluster, smlt2375-smlt2367, was significantly upregulated in KJΔChrR and reverted to the wild-type level in KJΔChrRΔRpoEc. smlt2375-smlt2367 cluster was located upstream of the rpoEc-chrR-chrA operon and divergently transcribed, seeming to be involved in membrane lipid modification. Deletion of smlt2375-smlt2367 cluster from the chromosome of KJΔChrR reverted the superoxide tolerance and β-lactam susceptibility to the wild-type level.DiscussionThe rpoEc-chrR pair of S. maltophilia was involved in superoxide tolerance and β-lactam susceptibility. Notably, a novel regulatory circuit involving rpoEc-chrR-chrA operon and smlt2375-smlt2367 cluster was revealed. |
| format | Article |
| id | doaj-art-15a05c6b984a4e5a9ba2b5b476ddf9a9 |
| institution | Kabale University |
| issn | 2235-2988 |
| language | English |
| publishDate | 2025-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj-art-15a05c6b984a4e5a9ba2b5b476ddf9a92025-02-04T06:31:51ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882025-02-011510.3389/fcimb.2025.14920081492008Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophiliaRen-Hsuan Ku0Hsu-Feng Lu1Li-Hua Li2Li-Hua Li3Ting-Yu Yeh4Yi-Tsung Lin5Yi-Tsung Lin6Tsuey-Ching Yang7Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, TaiwanDepartment of Medical Laboratory Science and Biotechnology, Asia University, Taichung, TaiwanDepartment of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, TaiwanDepartment of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, TaiwanDivision of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, TaiwanSchool of Medicine, National Yang Ming Chiao Tung University, Taipei, TaiwanDepartment of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, TaiwanIntroductionThe rpoE-chrR pair is a regulatory system used by photosynthetic microorganisms to overcome singlet oxygen stress. rpoE and chrR encode the sigma factor σE and anti-sigma factor ChrR, respectively. Stenotrophomonas maltophilia, an opportunistic pathogen, is a multidrug-resistant gram-negative bacterium. Although it is not a photosynthetic microorganism, a rpoE-chrR homolog (smlt2377-smlt2378) was found in the S. maltophilia genome. In this study, we aimed to assess the significance of σEc-ChrR pair in oxidative stress alleviation and antibiotic susceptibility of S. maltophilia KJ.MethodsReverse transcription-polymerase chain reaction was used to validate the presence of operon. The contribution of rpoEc-chrR-chrA operon to oxidative stress alleviation and antibiotic susceptibility was evaluated using mutant constructs and stress-tolerance assays. RNA-seq transcriptome assay of wild-type KJ, KJΔChrR (chrR mutant), and KJΔChrRΔRpoEc (chrR/rpoEc double mutant) was performed to reveal the σEc regulon.ResultsThe rpoEc-chrR pair and downstream chrA formed an operon. Inactivation of chrR upregulated the expression of rpoEc-chrR-chrA operon in an σEc- and ChrA-dependent manner. σEc activation contributed to superoxide tolerance and increased β-lactam susceptibility but did not affect the tolerance to singlet oxygen and hydrogen peroxide. Transcriptome analysis revealed that expression of the nine-gene cluster, smlt2375-smlt2367, was significantly upregulated in KJΔChrR and reverted to the wild-type level in KJΔChrRΔRpoEc. smlt2375-smlt2367 cluster was located upstream of the rpoEc-chrR-chrA operon and divergently transcribed, seeming to be involved in membrane lipid modification. Deletion of smlt2375-smlt2367 cluster from the chromosome of KJΔChrR reverted the superoxide tolerance and β-lactam susceptibility to the wild-type level.DiscussionThe rpoEc-chrR pair of S. maltophilia was involved in superoxide tolerance and β-lactam susceptibility. Notably, a novel regulatory circuit involving rpoEc-chrR-chrA operon and smlt2375-smlt2367 cluster was revealed.https://www.frontiersin.org/articles/10.3389/fcimb.2025.1492008/fullStenotrophomonas maltophiliasinglet oxygenβ-lactam susceptibilityoxidative stresssigma factor |
| spellingShingle | Ren-Hsuan Ku Hsu-Feng Lu Li-Hua Li Li-Hua Li Ting-Yu Yeh Yi-Tsung Lin Yi-Tsung Lin Tsuey-Ching Yang Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia Frontiers in Cellular and Infection Microbiology Stenotrophomonas maltophilia singlet oxygen β-lactam susceptibility oxidative stress sigma factor |
| title | Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia |
| title_full | Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia |
| title_fullStr | Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia |
| title_full_unstemmed | Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia |
| title_short | Roles of the rpoEc-chrR-chrA operon in superoxide tolerance and β-lactam susceptibility of Stenotrophomonas maltophilia |
| title_sort | roles of the rpoec chrr chra operon in superoxide tolerance and β lactam susceptibility of stenotrophomonas maltophilia |
| topic | Stenotrophomonas maltophilia singlet oxygen β-lactam susceptibility oxidative stress sigma factor |
| url | https://www.frontiersin.org/articles/10.3389/fcimb.2025.1492008/full |
| work_keys_str_mv | AT renhsuanku rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT hsufenglu rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT lihuali rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT lihuali rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT tingyuyeh rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT yitsunglin rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT yitsunglin rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia AT tsueychingyang rolesoftherpoecchrrchraoperoninsuperoxidetoleranceandblactamsusceptibilityofstenotrophomonasmaltophilia |