Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing
Persister cells are difficult to eliminate because they are tolerant to antibiotic stress. In the present study, using artificially induced Escherichia coli persister cells, we found that reactive oxygen species (ROS) have greater effects on persister cells than on exponential cells. Thus, we examin...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2020-09-01
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| Series: | Frontiers in Cellular and Infection Microbiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fcimb.2020.00496/full |
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| author | Aki Kawano Ryota Yamasaki Tatsuya Sakakura Yoshiyuki Takatsuji Tetsuya Haruyama Yoshie Yoshioka Wataru Ariyoshi |
| author_facet | Aki Kawano Ryota Yamasaki Tatsuya Sakakura Yoshiyuki Takatsuji Tetsuya Haruyama Yoshie Yoshioka Wataru Ariyoshi |
| author_sort | Aki Kawano |
| collection | DOAJ |
| description | Persister cells are difficult to eliminate because they are tolerant to antibiotic stress. In the present study, using artificially induced Escherichia coli persister cells, we found that reactive oxygen species (ROS) have greater effects on persister cells than on exponential cells. Thus, we examined which types of ROS could effectively eliminate persister cells and determined the mechanisms underlying the effects of these ROS. Ultraviolet (UV) light irradiation can kill persister cells, and bacterial viability is markedly increased under UV shielding. UV induces the production of ROS, which kill bacteria by moving toward the shielded area. Electron spin resonance-based analysis confirmed that hydroxyl radicals are produced by UV irradiation, although singlet oxygen is not produced. These results clearly revealed that ROS sterilizes persister cells more effectively compared to the sterilization of exponential cells (**p < 0.01). These ROS do not injure the bacterial cell wall but rather invade the cell, followed by cell killing. Additionally, the sterilization effect on persister cells was increased by exposure to oxygen plasma during UV irradiation. However, vapor conditions decreased persister cell sterilization by reducing the levels of hydroxyl radicals. We also verified the effect of ROS against bacteria in biofilms that are more resistant than planktonic cells. Although UV alone could not completely sterilize the biofilm bacteria, UV with ROS achieved complete sterilization. Our results demonstrate that persister cells strongly resist the effects of antibiotics and starvation stress but are less able to withstand exposure to ROS. It was shown that ROS does not affect the cell membrane but penetrates it and acts internally to kill persister cells. In particular, it was clarified that the hydroxy radical is an effective sterilizer to kill persister cells. |
| first_indexed | 2024-12-14T21:17:16Z |
| format | Article |
| id | doaj.art-86a7707844af40cea254c9380a63a2a8 |
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| issn | 2235-2988 |
| language | English |
| last_indexed | 2024-12-14T21:17:16Z |
| publishDate | 2020-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cellular and Infection Microbiology |
| spelling | doaj.art-86a7707844af40cea254c9380a63a2a82022-12-21T22:47:02ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882020-09-011010.3389/fcimb.2020.00496497552Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell KillingAki Kawano0Ryota Yamasaki1Tatsuya Sakakura2Yoshiyuki Takatsuji3Tetsuya Haruyama4Yoshie Yoshioka5Wataru Ariyoshi6Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, JapanDivision of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, JapanDivision of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, JapanDivision of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, JapanDivision of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, JapanDivision of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, JapanDivision of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, JapanPersister cells are difficult to eliminate because they are tolerant to antibiotic stress. In the present study, using artificially induced Escherichia coli persister cells, we found that reactive oxygen species (ROS) have greater effects on persister cells than on exponential cells. Thus, we examined which types of ROS could effectively eliminate persister cells and determined the mechanisms underlying the effects of these ROS. Ultraviolet (UV) light irradiation can kill persister cells, and bacterial viability is markedly increased under UV shielding. UV induces the production of ROS, which kill bacteria by moving toward the shielded area. Electron spin resonance-based analysis confirmed that hydroxyl radicals are produced by UV irradiation, although singlet oxygen is not produced. These results clearly revealed that ROS sterilizes persister cells more effectively compared to the sterilization of exponential cells (**p < 0.01). These ROS do not injure the bacterial cell wall but rather invade the cell, followed by cell killing. Additionally, the sterilization effect on persister cells was increased by exposure to oxygen plasma during UV irradiation. However, vapor conditions decreased persister cell sterilization by reducing the levels of hydroxyl radicals. We also verified the effect of ROS against bacteria in biofilms that are more resistant than planktonic cells. Although UV alone could not completely sterilize the biofilm bacteria, UV with ROS achieved complete sterilization. Our results demonstrate that persister cells strongly resist the effects of antibiotics and starvation stress but are less able to withstand exposure to ROS. It was shown that ROS does not affect the cell membrane but penetrates it and acts internally to kill persister cells. In particular, it was clarified that the hydroxy radical is an effective sterilizer to kill persister cells.https://www.frontiersin.org/article/10.3389/fcimb.2020.00496/fullreactive oxygen speciespersisterEscherichia coliradical vapor reactorbiofilm |
| spellingShingle | Aki Kawano Ryota Yamasaki Tatsuya Sakakura Yoshiyuki Takatsuji Tetsuya Haruyama Yoshie Yoshioka Wataru Ariyoshi Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing Frontiers in Cellular and Infection Microbiology reactive oxygen species persister Escherichia coli radical vapor reactor biofilm |
| title | Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing |
| title_full | Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing |
| title_fullStr | Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing |
| title_full_unstemmed | Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing |
| title_short | Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing |
| title_sort | reactive oxygen species penetrate persister cell membranes of escherichia coli for effective cell killing |
| topic | reactive oxygen species persister Escherichia coli radical vapor reactor biofilm |
| url | https://www.frontiersin.org/article/10.3389/fcimb.2020.00496/full |
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