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Xu T, Yan X, Kang A, Yang L, Li X, Tian Y, Yang R, Qin S, Guo Y. Development of Membrane-Targeting Fluorescent 2-Phenyl-1 H-phenanthro[9,10- d]imidazole-Antimicrobial Peptide Mimic Conjugates against Methicillin-Resistant Staphylococcus aureus. J Med Chem 2024; 67:9302-9317. [PMID: 38491982 DOI: 10.1021/acs.jmedchem.4c00436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
The escalation of multidrug-resistant bacterial infections, especially infections caused by methicillin-resistant Staphylococcus aureus (MRSA), underscores the urgent need for novel antimicrobial drugs. Here, we synthesized a series of amphiphilic 2-phenyl-1H-phenanthro[9,10-d]imidazole-antimicrobial peptide (AMP) mimic conjugates (III1-30). Among them, compound III13 exhibited excellent antibacterial activity against G+ bacteria and clinical MRSA isolates (MIC = 0.5-2 μg/mL), high membrane selectivity, and low toxicity. Additionally, compared with traditional clinical antibiotics, III13 demonstrated rapid bactericidal efficacy and was less susceptible to causing bacterial resistance. Mechanistic studies revealed that III13 targets phosphatidylglycerol (PG) on bacterial membranes to disrupt membrane integrity, leading to an increase in intracellular ROS and leakage of proteins and DNA, ultimately causing bacterial cell death. Furthermore, III13 possessed good fluorescence properties with potential for further dynamic monitoring of the antimicrobial process. Notably, III13 showed better in vivo efficacy against MRSA compared to vancomycin, suggesting its potential as a promising candidate for anti-MRSA medication.
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Affiliation(s)
- Ting Xu
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang 421001, Hunan Province, China
| | - Xiaoting Yan
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Ayue Kang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Longhua Yang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Xinhui Li
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Yue Tian
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Ruige Yang
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang 421001, Hunan Province, China
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Shangshang Qin
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
| | - Yong Guo
- Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang 421001, Hunan Province, China
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, Henan Province, China
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2
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Gupta A, Imlay JA. How a natural antibiotic uses oxidative stress to kill oxidant-resistant bacteria. Proc Natl Acad Sci U S A 2023; 120:e2312110120. [PMID: 38109539 PMCID: PMC10756299 DOI: 10.1073/pnas.2312110120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 11/17/2023] [Indexed: 12/20/2023] Open
Abstract
Natural products that possess antibiotic and antitumor qualities are often suspected of working through oxidative mechanisms. In this study, two quinone-based small molecules were compared. Menadione, a classic redox-cycling compound, was confirmed to generate high levels of reactive oxygen species inside Escherichia coli. It inactivated iron-cofactored enzymes and blocked growth. However, despite the substantial levels of oxidants that it produced, it was unable to generate significant DNA damage and was not lethal. Streptonigrin, in contrast, was poorer at redox cycling and did not inactivate enzymes or block growth; however, even in low doses, it damaged DNA and killed cells. Its activity required iron and oxygen, and in vitro experiments indicated that its quinone moiety transferred electrons through the adjacent iron atom to oxygen. Additionally, in vitro experiments revealed that streptonigrin was able to damage DNA without inhibition by catalase, indicating that hydrogen peroxide was not involved. We infer that streptonigrin can reduce bound oxygen directly to a ferryl species, which then oxidizes the adjacent DNA, without release of superoxide or hydrogen peroxide intermediates. This scheme allows streptonigrin to kill a bacterial cell without interference by scavenging enzymes. Moreover, its minimal redox-cycling behavior avoids alerting either the OxyR or the SoxRS systems, which otherwise would block killing. This example highlights qualities that may be important in the design of oxidative drugs. These results also cast doubt on proposals that bacteria can be killed by stressors that merely stimulate intracellular O2- and H2O2 formation.
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Affiliation(s)
- Anshika Gupta
- Department of Microbiology, University of Illinois, Urbana, IL61801
| | - James A. Imlay
- Department of Microbiology, University of Illinois, Urbana, IL61801
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3
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Qi W, Jonker MJ, de Leeuw W, Brul S, ter Kuile BH. Reactive oxygen species accelerate de novo acquisition of antibiotic resistance in E. coli. iScience 2023; 26:108373. [PMID: 38025768 PMCID: PMC10679899 DOI: 10.1016/j.isci.2023.108373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/06/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Reactive oxygen species (ROS) produced as a secondary effect of bactericidal antibiotics are hypothesized to play a role in killing bacteria. If correct, ROS may play a role in development of de novo resistance. Here we report that single-gene knockout strains with reduced ROS scavenging exhibited enhanced ROS accumulation and more rapid acquisition of resistance when exposed to sublethal levels of bactericidal antibiotics. Consistent with this observation, the ROS scavenger thiourea in the medium decelerated resistance development. Thiourea downregulated the transcriptional level of error-prone DNA polymerase and DNA glycosylase MutM, which counters the incorporation and accumulation of 8-hydroxy-2'-deoxyguanosine (8-HOdG) in the genome. The level of 8-HOdG significantly increased following incubation with bactericidal antibiotics but decreased after treatment with the ROS scavenger thiourea. These observations suggest that in E. coli sublethal levels of ROS stimulate de novo development of resistance, providing a mechanistic basis for hormetic responses induced by antibiotics.
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Affiliation(s)
- Wenxi Qi
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Martijs J. Jonker
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Wim de Leeuw
- RNA Biology & Applied Bioinformatics, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Stanley Brul
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Benno H. ter Kuile
- Laboratory for Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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4
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Bosveli A, Griboura N, Kampouropoulos I, Kalaitzakis D, Montagnon T, Vassilikogiannakis G. The Rapid Synthesis of Colibactin Warhead Model Compounds Using New Metal-Free Photocatalytic Cyclopropanation Reactions Facilitates the Investigation of Biological Mechanisms. Chemistry 2023; 29:e202301713. [PMID: 37452669 DOI: 10.1002/chem.202301713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/06/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Herein, we report the synthesis of a series of colibactin warhead model compounds using two newly developed metal-free photocatalytic cyclopropanation reactions. These mild cyclopropanations expand the known applications of eosin within synthesis. A halogen atom transfer reaction mode has been harnessed so that dihalides can be used as the cyclopropanating agents. The colibactin warhead models were then used to provide new insight into two key mechanisms in colibactin chemistry. An explanation is provided for why the colibactin warhead sometimes undergoes a ring expansion-addition reaction to give fused cyclobutyl products while at other times nucleophiles add directly to the cyclopropyl unit (as when DNA adds to colibactin). Finally, we provide some evidence that Cu(II) chelated to colibactin may catalyze an important oxidation of the colibactin-DNA adduct. The Cu(I) generated as a result could then also play a role in inducing double strand breaks in DNA.
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Affiliation(s)
- Artemis Bosveli
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | - Nefeli Griboura
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | | | - Dimitris Kalaitzakis
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
| | - Tamsyn Montagnon
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003, Iraklion, Crete
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5
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Yang X, Liu X, Nie Y, Zhan F, Zhu B. Oxidative stress and ROS-mediated cellular events in RSV infection: potential protective roles of antioxidants. Virol J 2023; 20:224. [PMID: 37798799 PMCID: PMC10557227 DOI: 10.1186/s12985-023-02194-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/27/2023] [Indexed: 10/07/2023] Open
Abstract
Respiratory syncytial virus (RSV), a member of the Pneumoviridae family, can cause severe acute lower respiratory tract infection in infants, young children, immunocompromised individuals and elderly people. RSV is associated with an augmented innate immune response, enhanced secretion of inflammatory cytokines, and necrosis of infected cells. Oxidative stress, which is mainly characterized as an imbalance in the production of reactive oxygen species (ROS) and antioxidant responses, interacts with all the pathophysiologic processes above and is receiving increasing attention in RSV infection. A gradual accumulation of evidence indicates that ROS overproduction plays an important role in the pathogenesis of severe RSV infection and serves as a major factor in pulmonary inflammation and tissue damage. Thus, antioxidants seem to be an effective treatment for severe RSV infection. This article mainly reviews the information on oxidative stress and ROS-mediated cellular events during RSV infection for the first time.
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Affiliation(s)
- Xue Yang
- Department of Pediatrics, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, Hubei, China
| | - Xue Liu
- Department of Pediatrics, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, Hubei, China
| | - Yujun Nie
- Department of Pediatrics, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, Hubei, China
| | - Fei Zhan
- Department of Pediatrics, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, Hubei, China
| | - Bin Zhu
- Department of Pediatrics, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441021, Hubei, China.
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Kwun MS, Lee DG. Ferroptosis-Like Death in Microorganisms: A Novel Programmed Cell Death Following Lipid Peroxidation. J Microbiol Biotechnol 2023; 33:992-997. [PMID: 37463851 PMCID: PMC10471485 DOI: 10.4014/jmb.2307.07002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/05/2023] [Accepted: 07/14/2023] [Indexed: 07/20/2023]
Abstract
Ferroptosis is a new kind of programmed cell death of which occurrence in microorganisms is not clearly verified. The elevated level of reactive oxygen species (ROS) influences cellular metabolisms through highly reactive hydroxyl radical formation under the iron-dependent Fenton reaction. Iron contributes to ROS production and acts as a cofactor for lipoxygenase to catalyze poly unsaturated fatty acid (PUFA) oxidation, exerting oxidative damage in cells. While ferroptosis is known to take place only in mammalian cells, recent studies discovered the possible ferroptosis-like death in few specific microorganisms. Capacity of integrating PUFA into intracellular membrane phospholipid has been considered as a key factor in bacterial or fungal ferroptosis-like death. Vibrio species in bacteria and Saccharomyces cerevisiae in fungi exhibited certain characteristics. Therefore, this review focus on introducing the occurrence of ferroptosis-like death in microorganisms and investigating the mode of action underlying the cells based on contribution of lipid peroxidation and iron-dependent reaction.
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Affiliation(s)
- Min Seok Kwun
- School of Life Sciences, BK 21 FOUR KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daehakro 80, Bukgu, Daegu 41566, Republic of Korea
| | - Dong Gun Lee
- School of Life Sciences, BK 21 FOUR KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daehakro 80, Bukgu, Daegu 41566, Republic of Korea
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7
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Hong S, Su S, Gao Q, Chen M, Xiao L, Cui R, Guo Y, Xue Y, Wang D, Niu J, Huang H, Zhao X. Enhancement of β-Lactam-Mediated Killing of Gram-Negative Bacteria by Lysine Hydrochloride. Microbiol Spectr 2023; 11:e0119823. [PMID: 37310274 PMCID: PMC10434284 DOI: 10.1128/spectrum.01198-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/19/2023] [Indexed: 06/14/2023] Open
Abstract
Widespread bacterial resistance among Gram-negative bacteria is rapidly depleting our antimicrobial arsenal. Adjuvants that enhance the bactericidal activity of existing antibiotics provide a way to alleviate the resistance crisis, as new antimicrobials are becoming increasingly difficult to develop. The present work with Escherichia coli revealed that neutralized lysine (lysine hydrochloride) enhances the bactericidal activity of β-lactams in addition to increasing bacteriostatic activity. When combined, lysine hydrochloride and β-lactam increased expression of genes involved in the tricarboxylic acid (TCA) cycle and raised reactive oxygen species (ROS) levels; as expected, agents known to mitigate bactericidal effects of ROS reduced lethality from the combination treatment. Lysine hydrochloride had no enhancing effect on the lethal action of fluoroquinolones or aminoglycosides. Characterization of a tolerant mutant indicated involvement of the FtsH/HflkC membrane-embedded protease complex in lethality enhancement. The tolerant mutant, which carried a V86F substitution in FtsH, exhibited decreased lipopolysaccharide levels, reduced expression of TCA cycle genes, and reduced levels of ROS. Lethality enhancement by lysine hydrochloride was abolished by treating cultures with Ca2+ or Mg2+, cations known to stabilize the outer membrane. These data, plus damage observed by scanning electron microscopy, indicate that lysine stimulates β-lactam lethality by disrupting the outer membrane. Lethality enhancement of β-lactams by lysine hydrochloride was also observed with Acinetobacter baumannii and Pseudomonas aeruginosa, thereby suggesting that the phenomenon is common among Gram-negative bacteria. Arginine hydrochloride behaved in a similar way. Overall, the combination of lysine or arginine hydrochloride and β-lactam offers a new way to increase β-lactam lethality with Gram-negative pathogens. IMPORTANCE Antibiotic resistance among Gram-negative pathogens is a serious medical problem. The present work describes a new study in which a nontoxic nutrient increases the lethal action of clinically important β-lactams. Elevated lethality is expected to reduce the emergence of resistant mutants. The effects were observed with significant pathogens (Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa), indicating widespread applicability. Examination of tolerant mutants and biochemical measurements revealed involvement of endogenous reactive oxygen species in response to outer membrane perturbation. These lysine hydrochloride-β-lactam data support the hypothesis that lethal stressors can stimulate the accumulation of ROS. Genetic and biochemical work also revealed how an alteration in a membrane protease, FtsH, abolishes lysine stimulation of β-lactam lethality. Overall, the work presents a method for antimicrobial enhancement that should be safe, easy to administer, and likely to apply to other nutrients, such as arginine.
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Affiliation(s)
- Shouqiang Hong
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Shaopeng Su
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Qiong Gao
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Miaomiao Chen
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Lisheng Xiao
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Runbo Cui
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Yinli Guo
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Yunxin Xue
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Dai Wang
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
| | - Jianjun Niu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen, Fujian Province, China
| | - Haihui Huang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Xilin Zhao
- State Key Laboratory of Vaccines for Infectious Diseases, Xiang An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China
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Oswin HP, Haddrell AE, Hughes C, Otero-Fernandez M, Thomas RJ, Reid JP. Oxidative Stress Contributes to Bacterial Airborne Loss of Viability. Microbiol Spectr 2023; 11:e0334722. [PMID: 36912675 PMCID: PMC10101003 DOI: 10.1128/spectrum.03347-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 01/18/2023] [Indexed: 03/14/2023] Open
Abstract
While the airborne decay of bacterial viability has been observed for decades, an understanding of the mechanisms driving the decay has remained elusive. The airborne transport of bacteria is often a key step in their life cycle and as such, characterizing the mechanisms driving the airborne decay of bacteria is an essential step toward a more complete understanding of microbial ecology. Using the Controlled Electrodynamic Levitation and Extraction of Bioaerosols onto a Substrate (CELEBS), it was possible to systematically evaluate the impact of different physicochemical and environmental parameters on the survival of Escherichia coli in airborne droplets of Luria Bertani broth. Rather than osmotic stress driving the viability loss, as was initially considered, oxidative stress was found to play a key role. As the droplets evaporate and equilibrate with the surrounding environment, the surface-to-volume ratio increases, which in turn increased the formation of reactive oxygen species in the droplet. These reactive oxygen species appear to play a key role in driving the airborne loss of viability of E. coli. IMPORTANCE The airborne transport of bacteria has a wide range of impacts, from disease transmission to cloud formation. By understanding the factors that influence the airborne stability of bacteria, we can better understand these processes. However, while we have known for several decades that airborne bacteria undergo a gradual loss of viability, we have not previously identified the mechanisms driving this process. In this work, we discovered that oxygen surrounding an airborne droplet facilitates the formation of reactive oxygen species within the droplet, which then gradually damage and kill bacteria within the droplet. This discovery indicates that adaptations to help bacteria deal with oxidative stress may also aid their airborne survival and be essential adaptations for bacterial airborne pathogens. Understanding the adaptations bacteria need to survive in airborne droplets could eventually lead to the development of novel antimicrobials designed to inhibit their airborne survival, helping to prevent the transmission of disease.
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Affiliation(s)
- Henry P. Oswin
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Allen E. Haddrell
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Cordelia Hughes
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Mara Otero-Fernandez
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
| | - Richard J. Thomas
- Defence Science Technology Laboratory (DSTL), Porton Down, Salisbury, United Kingdom
| | - Jonathan P. Reid
- School of Chemistry, Cantock’s Close, University of Bristol, Bristol, United Kingdom
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Huo C, Zhao Q, Liu R, Li X, He F, Jing M, Wan J, Zong W. Cytotoxicity and Oxidative Stress Effects of Indene on Coelomocytes of Earthworm ( Eisenia foetida): Combined Analysis at Cellular and Molecular Levels. TOXICS 2023; 11:136. [PMID: 36851011 PMCID: PMC9961689 DOI: 10.3390/toxics11020136] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/24/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
Indene (IND) is a kind of important aromatic hydrocarbon that is extracted from coal tar and has important applications in industry and biology. In the process of production and utilization, it is easy to enter the soil and produce toxic effects on the soil or organisms. The earthworm is an important organism in the soil. The toxicity of indene on earthworm coelomocytes is rarely studied, and the oxidative stress effects of IND on earthworm coelomocytes remain unclear. In this study, coelomocytes from earthworms and antioxidant enzymes were selected as the research targets. In addition, IND caused oxidative stress, and its related toxic effects and mechanisms were systematically studied and evaluated at the cellular and molecular levels. The results showed that IND destroyed the redox balance in earthworm coelomocytes, and the large accumulation of reactive oxygen species (ROS) significantly inhibited the activities of the antioxidant system, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), and caused lipid peroxidation and membrane permeability changes, resulting in a decrease in cell viability to 74.5% of the control group. At the molecular level, IND was bound to SOD by the arene-H bond, and the binding constant was 4.95 × 103. IND changed the secondary structure of the SOD and led to a loosening of the structure of the SOD peptide chain. Meanwhile, IND caused SOD fluorescence sensitization, and molecular simulation showed that IND was mainly bound to the junction of SOD subunits. We hypothesized that the changes in SOD structure led to the increase in SOD activity. This research can provide a scientific basis for IND toxicity evaluation.
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Affiliation(s)
- Chengqian Huo
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Qiang Zhao
- Shandong Provincial Eco-Environment Monitoring Center, 3377 Jingshi Dong Lu, Jinan 250100, China
| | - Rutao Liu
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Xiangxiang Li
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Falin He
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Mingyang Jing
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Jingqiang Wan
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, 72# Jimo Binhai Road, Qingdao 266237, China
| | - Wansong Zong
- College of Population, Resources and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014, China
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Fan L, Pan Z, Liao X, Zhong Y, Guo J, Pang R, Chen X, Ye G, Su Y. Uracil restores susceptibility of methicillin-resistant Staphylococcus aureus to aminoglycosides through metabolic reprogramming. Front Pharmacol 2023; 14:1133685. [PMID: 36762116 PMCID: PMC9902350 DOI: 10.3389/fphar.2023.1133685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 01/16/2023] [Indexed: 01/26/2023] Open
Abstract
Background: Methicillin-resistant Staphylococcus aureus (MRSA) has now become a major nosocomial pathogen bacteria and resistant to many antibiotics. Therefore, Development of novel approaches to combat the disease is especially important. The present study aimed to provide a novel approach involving the use of nucleotide-mediated metabolic reprogramming to tackle intractable methicillin-resistant S. aureus (MRSA) infections. Objective: This study aims to explore the bacterial effects and mechanism of uracil and gentamicin in S. aureus. Methods: Antibiotic bactericidal assays was used to determine the synergistic bactericidal effect of uracil and gentamicin. How did uracil regulate bacterial metabolism including the tricarboxylic acid (TCA) cycle by GC-MS-based metabolomics. Next, genes and activity of key enzymes in the TCA cycle, PMF, and intracellular aminoglycosides were measured. Finally, bacterial respiration, reactive oxygen species (ROS), and ATP levels were also assayed in this study. Results: In the present study, we found that uracil could synergize with aminoglycosides to kill MRSA (USA300) by 400-fold. Reprogramming metabolomics displayed uracil reprogrammed bacterial metabolism, especially enhanced the TCA cycle to elevate NADH production and proton motive force, thereby promoting the uptake of antibiotics. Furthermore, uracil increased cellular respiration and ATP production, resulting the generation of ROS. Thus, the combined activity of uracil and antibiotics induced bacterial death. Inhibition of the TCA cycle or ROS production could attenuate bactericidal efficiency. Moreover, uracil exhibited bactericidal activity in cooperation with aminoglycosides against other pathogenic bacteria. In a mouse mode of MRSA infection, the combination of gentamicin and uracil increased the survival rate of infected mice. Conclusion: Our results suggest that uracil enhances the activity of bactericidal antibiotics to kill Gram-positive bacteria by modulating bacterial metabolism.
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Affiliation(s)
- Lvyuan Fan
- MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Department of Cell Biology and Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Zhiyu Pan
- MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Department of Cell Biology and Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Xu Liao
- Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Yilin Zhong
- MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Department of Cell Biology and Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Juan Guo
- MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Department of Cell Biology and Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China
| | - Rui Pang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xinhai Chen
- Institute of Infectious Diseases Shenzhen Bay Laboratory, Shenzhen, China
| | - Guozhu Ye
- Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China,*Correspondence: Yubin Su, ; Guozhu Ye,
| | - Yubin Su
- MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Department of Cell Biology and Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China,*Correspondence: Yubin Su, ; Guozhu Ye,
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11
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HslO ameliorates arrested ΔrecA polA cell growth and reduces DNA damage and oxidative stress responses. Sci Rep 2022; 12:22182. [PMID: 36564489 PMCID: PMC9789031 DOI: 10.1038/s41598-022-26703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Chromosome damage combined with defective recombinase activity has been widely considered to render cells inviable, owing to deficient double-strand break repair. However, temperature-sensitive recAts polA cells grow well upon induction of DNA damage and supplementation with catalase at restrictive temperatures. These treatments reduce intracellular reactive oxygen species (ROS) levels, which suggests that recAts polA cells are susceptible to ROS, but not chronic chromosome damage. Therefore, we investigated whether polA cells can tolerate a complete lack of recombinase function. We introduced a ΔrecA allele in polA cells in the presence or absence of the hslO-encoding redox molecular chaperon Hsp33 expression plasmid. Induction of the hslO gene with IPTG resulted in increased cell viability in ΔrecA polA cells with the hslO expression plasmid. ΔrecA polA cells in the absence of the hslO expression plasmid showed rich medium sensitivity with increasing ROS levels. Adding catalase to the culture medium considerably rescued growth arrest and decreased ROS. These results suggest that hslO expression manages oxidative stress to an acceptable level in cells with oxidative damage and rescues cell growth. Overall, ROS may regulate several processes, from damage response to cell division, via ROS-sensitive cell metabolism.
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12
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Hur JI, Kim J, Ryu S, Jeon B. Phylogenetic Association and Genetic Factors in Cold Stress Tolerance in Campylobacter jejuni. Microbiol Spectr 2022; 10:e0268122. [PMID: 36314968 PMCID: PMC9769813 DOI: 10.1128/spectrum.02681-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/13/2022] [Indexed: 12/24/2022] Open
Abstract
Campylobacter jejuni is a major foodborne pathogen transmitted to humans primarily via contaminated poultry meat. Since poultry meat is generally processed, distributed, and stored in the cold chain, the survival of C. jejuni at refrigeration temperatures crucially affects human exposure to C. jejuni. Here, we investigated genetic factors associated with cold stress tolerance in C. jejuni. Seventy-nine C. jejuni strains isolated from retail raw chicken exhibited different survival levels at 4°C for 21 days. Multilocus sequence typing (MLST) clonal complex 21 (CC-21) and CC-443 were dominant among cold stress-tolerant strains, whereas CC-45 was common among cold stress-sensitive strains. Genome-wide average nucleotide identity (ANI) analysis identified a phylogenetic cluster associated with cold stress tolerance. Moreover, a pangenome analysis revealed 58 genes distinctively present in the cold stress-tolerant phylogenetic cluster. Among these 58 genes, cfrA, encoding the ferric enterobactin receptor involved in ion transport and metabolism, was selected for further analysis. Remarkably, the viability of a ΔcfrA mutant at 4°C was significantly decreased, while the levels of total reactive oxygen species and intracellular iron exceeded those of the wild type. Additionally, a knockout mutation of cfrA also significantly decreased the viability of three cold stress-tolerant isolates at 4°C, confirming the role of cfrA in cold stress tolerance. The results of this study demonstrate that unique phylogenetic clusters of C. jejuni associated with cold stress tolerance exist and that cfrA is a genetic factor contributing to cold stress tolerance in C. jejuni. IMPORTANCE The tolerance of foodborne pathogens to environmental stresses significantly affects food safety. Several studies have demonstrated that C. jejuni survives extended exposures to low temperatures, but the mechanisms of cold stress tolerance are not fully understood. Here, we demonstrate that C. jejuni strains in certain phylogenetic groups exhibit increased tolerance to cold stress. Notably, cfrA is present in the phylogenetic cluster associated with cold stress tolerance and plays a role in the survival of C. jejuni at low temperatures by alleviating oxidative stress. This is the first study to discover phylogenetic associations involving cold stress tolerance and to identify genetic elements conferring cold stress tolerance to C. jejuni.
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Affiliation(s)
- Jeong In Hur
- Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Jinshil Kim
- Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Byeonghwa Jeon
- Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA
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13
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Aribisala JO, Sabiu S. Redox Impact on Bacterial Macromolecule: A Promising Avenue for Discovery and Development of Novel Antibacterials. Biomolecules 2022; 12:1545. [PMID: 36358894 PMCID: PMC9688007 DOI: 10.3390/biom12111545] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 07/30/2023] Open
Abstract
Antibiotic resistance in bacteria has remained a serious public health concern, resulting in substantial deaths and morbidity each year. Factors such as mutation and abuse of currently available antibiotics have contributed to the bulk of the menace. Hence, the introduction and implementation of new therapeutic strategies are imperative. Of these strategies, data supporting the role of reactive oxygen species (ROS) in bacterial lethality are intriguing, with several antimicrobials, including antibiotics such as fluoroquinolones, β-lactams, and aminoglycosides, as well as natural plant compounds, being remarkably implicated. Following treatment with ROS-inducing antimicrobials, ROS such as O2•-, •OH, and H2O2 generated in bacteria, which the organism is unable to detoxify, damage cellular macromolecules such as proteins, lipids, and nucleic acids and results in cell death. Despite the unique mechanism of action of ROS-inducing antibacterials and significant studies on ROS-mediated means of bacterial killing, the field remains a topical one, with contradicting viewpoints that require frequent review. Here, we appraised the antibacterial agents (antibiotics, natural and synthetic compounds) implicated in ROS generation and the safety concerns associated with their usage. Further, background information on the sources and types of ROS in bacteria, the mechanism of bacterial lethality via oxidative stress, as well as viewpoints on the ROS hypothesis undermining and solidifying this concept are discussed.
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14
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Tang A, Ren Q, Wu Y, Wu C, Cheng Y. Investigation into the Antibacterial Mechanism of Biogenic Tellurium Nanoparticles and Precursor Tellurite. Int J Mol Sci 2022; 23:ijms231911697. [PMID: 36232999 PMCID: PMC9569536 DOI: 10.3390/ijms231911697] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/19/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022] Open
Abstract
Antibacterial tellurium nanoparticles have the advantages of high activity and biocompatibility. Microbial synthesis of Te nanoparticles is not only a green technology but builds new ecological relationships in diverse environments. However, the antibacterial mechanism of Te nanoparticles is largely unclear. In this study, we report the bacterial synthesis of rod-shaped Te nanoparticles (BioTe) with high antibacterial activity against Escherichia coli. Morphology and permeability examination indicates that membrane damage is the primary reason for the antibacterial activity of BioTe, rather than ROS production and DNA damage. Moreover, a comparison of transcriptome and relative phenotypes reveals the difference in antibacterial mechanisms between BioTe and tellurite. Based on our evidence, we propose an antibacterial mode of rod-shaped BioTe, in which positively charged BioTe interact with the cell membrane through electrostatic attraction and then penetrate the membrane by using their sharp ends. In contrast, tellurite toxicity might be involved in sulfur metabolism.
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Affiliation(s)
- Aiguo Tang
- School of Life Sciences, Anhui University, Hefei 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, China
| | - Qianwen Ren
- Anhui Province Key Laboratory of Industrial Wastewater and Environmental Treatment, Hefei 230109, China
| | - Yaling Wu
- School of Life Sciences, Anhui University, Hefei 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, China
| | - Chao Wu
- Anhui Province Key Laboratory of Industrial Wastewater and Environmental Treatment, Hefei 230109, China
| | - Yuanyuan Cheng
- School of Life Sciences, Anhui University, Hefei 230601, China
- Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei 230601, China
- Anhui Key Laboratory of Modern Biomanufacturing, Hefei 230601, China
- Correspondence:
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15
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Revitt‐Mills SA, Wright EK, Vereker M, O'Flaherty C, McPherson F, Dawson C, van Oijen AM, Robinson A. Defects in DNA double‐strand break repair resensitize antibiotic‐resistant
Escherichia coli
to multiple bactericidal antibiotics. Microbiologyopen 2022; 11:e1316. [PMCID: PMC9500592 DOI: 10.1002/mbo3.1316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 09/03/2022] [Accepted: 09/03/2022] [Indexed: 11/11/2022] Open
Affiliation(s)
- Sarah A. Revitt‐Mills
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Elizabeth K. Wright
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Madaline Vereker
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Callum O'Flaherty
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Fairley McPherson
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Catherine Dawson
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Antoine M. van Oijen
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
| | - Andrew Robinson
- School of Chemistry and Molecular Bioscience, Molecular Horizons Institute University of Wollongong Wollongong New South Wales Australia
- Illawarra Health and Medical Research Institute Wollongong New South Wales Australia
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16
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Ketcham A, Freddolino PL, Tavazoie S. Intracellular acidification is a hallmark of thymineless death in E. coli. PLoS Genet 2022; 18:e1010456. [PMID: 36279294 PMCID: PMC9632930 DOI: 10.1371/journal.pgen.1010456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 11/03/2022] [Accepted: 10/01/2022] [Indexed: 11/05/2022] Open
Abstract
Thymidine starvation causes rapid cell death. This enigmatic process known as thymineless death (TLD) is the underlying killing mechanism of diverse antimicrobial and antineoplastic drugs. Despite decades of investigation, we still lack a mechanistic understanding of the causal sequence of events that culminate in TLD. Here, we used a diverse set of unbiased approaches to systematically determine the genetic and regulatory underpinnings of TLD in Escherichia coli. In addition to discovering novel genes in previously implicated pathways, our studies revealed a critical and previously unknown role for intracellular acidification in TLD. We observed that a decrease in cytoplasmic pH is a robust early event in TLD across different genetic backgrounds. Furthermore, we show that acidification is a causal event in the death process, as chemical and genetic perturbations that increase intracellular pH substantially reduce killing. We also observe a decrease in intracellular pH in response to exposure to the antibiotic gentamicin, suggesting that intracellular acidification may be a common mechanistic step in the bactericidal effects of other antibiotics.
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Affiliation(s)
- Alexandra Ketcham
- Department of Biological Sciences, Columbia University, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Peter L. Freddolino
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
| | - Saeed Tavazoie
- Department of Biological Sciences, Columbia University, New York, New York, United States of America
- Department of Systems Biology, Columbia University, New York, New York, United States of America
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, United States of America
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17
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Truncated Pleurocidin Derivative with High Pepsin Hydrolysis Resistance to Combat Multidrug-Resistant Pathogens. Pharmaceutics 2022; 14:pharmaceutics14102025. [PMID: 36297458 PMCID: PMC9610943 DOI: 10.3390/pharmaceutics14102025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 11/29/2022] Open
Abstract
The global prevalence of antimicrobial resistance calls for the development of novel antimicrobial agents, particularly for these orally available drugs. Structural modifications of the natural antimicrobial peptides (AMPs) provide a straightforward approach to develop potent antimicrobial agents with high specificity and low toxicity. In this study, we truncated 11-amino-acids at the C-terminus of Pleurocidin, an AMP produced by Pleuronectes americanus, and obtained four peptide analogues termed GK-1, GK-2, GK-3 and GK-4. Minimum inhibitory concentration (MIC) tests showed that GK-1 obtained by direct truncation of Pleurocidin has no antibacterial activity, while GK-2, GK-3 and GK-4 show considerable antibacterial activity with Pleurocidin. Notably, GK-4 displays rapid bacteriostatic activity, great stability and low hemolysis, as well as enhanced hydrolytic resistance to pepsin treatment. Mechanistic studies showed that GK-4 induces membrane damage by interacting with bacterial membrane-specific components, dissipates bacterial membrane potential and promotes the generation of ROS. SEM and CD analysis further confirmed the ability of GK-4 to resist pepsin hydrolysis, which may be attributed to its stable helicity structure. Collectively, our findings reveal that GK-4 is a potential orally available candidate to treat infections caused by multidrug-resistant pathogens.
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18
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Moxifloxacin-Mediated Killing of Mycobacterium tuberculosis Involves Respiratory Downshift, Reductive Stress, and Accumulation of Reactive Oxygen Species. Antimicrob Agents Chemother 2022; 66:e0059222. [PMID: 35975988 PMCID: PMC9487606 DOI: 10.1128/aac.00592-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Moxifloxacin is central to treatment of multidrug-resistant tuberculosis. Effects of moxifloxacin on the Mycobacterium tuberculosis redox state were explored to identify strategies for increasing lethality and reducing the prevalence of extensively resistant tuberculosis. A noninvasive redox biosensor and a reactive oxygen species (ROS)-sensitive dye revealed that moxifloxacin induces oxidative stress correlated with M. tuberculosis death. Moxifloxacin lethality was mitigated by supplementing bacterial cultures with an ROS scavenger (thiourea), an iron chelator (bipyridyl), and, after drug removal, an antioxidant enzyme (catalase). Lethality was also reduced by hypoxia and nutrient starvation. Moxifloxacin increased the expression of genes involved in the oxidative stress response, iron-sulfur cluster biogenesis, and DNA repair. Surprisingly, and in contrast with Escherichia coli studies, moxifloxacin decreased expression of genes involved in respiration, suppressed oxygen consumption, increased the NADH/NAD+ ratio, and increased the labile iron pool in M. tuberculosis. Lowering the NADH/NAD+ ratio in M. tuberculosis revealed that NADH-reductive stress facilitates an iron-mediated ROS surge and moxifloxacin lethality. Treatment with N-acetyl cysteine (NAC) accelerated respiration and ROS production, increased moxifloxacin lethality, and lowered the mutant prevention concentration. Moxifloxacin induced redox stress in M. tuberculosis inside macrophages, and cotreatment with NAC potentiated the antimycobacterial efficacy of moxifloxacin during nutrient starvation, inside macrophages, and in mice, where NAC restricted the emergence of resistance. Thus, NADH-reductive stress contributes to moxifloxacin-mediated killing of M. tuberculosis, and the respiration stimulator (NAC) enhances lethality and suppresses the emergence of drug resistance.
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19
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Wang X, Li H, Chen Y, Meng X, Yorgan Dieketseng M, Wang X, Yan S, Wang B, Zhou L, Zheng G. A neglected risk of nanoplastics as revealed by the promoted transformation of plasmid‐borne ampicillin resistance gene by
Escherichia coli. Environ Microbiol 2022; 24:4946-4959. [DOI: 10.1111/1462-2920.16178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 08/13/2022] [Indexed: 11/26/2022]
Affiliation(s)
- Xinxin Wang
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Hua Li
- College of Urban Construction, Nanjing Tech University Nanjing China
| | - Yu Chen
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Xiaoqing Meng
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Mahlatsi Yorgan Dieketseng
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Xiaomeng Wang
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Su Yan
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
| | - Baozhan Wang
- Department of Microbiology College of Life Sciences, Nanjing Agricultural University Nanjing China
| | - Lixiang Zhou
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization Nanjing China
| | - Guanyu Zheng
- Department of Environmental Engineering College of Resources and Environmental Sciences, Nanjing Agricultural University Nanjing China
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization Nanjing China
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20
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Ni X, Zhang M, Zhang J, Zhang Z, Dong S, Zhao L. Molecular mechanism of two functional protein structure changes under 2,3-butanedione-induced oxidative stress and apoptosis effects in the hepatocytes. Int J Biol Macromol 2022; 218:969-980. [PMID: 35907461 DOI: 10.1016/j.ijbiomac.2022.07.171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/21/2022] [Accepted: 07/21/2022] [Indexed: 11/24/2022]
Abstract
Food security has become closely watched with the occurrence of a series of food safety incidents in recent years. The widespread adoption of 2,3-butanedione (BUT), as a food additive, is an unpreventable significant risk factor to food security. Based on this, mouse hepatocyte AML-12 cells and two functional proteins (bovine serum albumin and lysozyme) were utilized as targeted receptors to study the adverse effects of BUT at the cellular and molecular levels. Results suggested that BUT could disrupt the redox balance of AML-12 cells, reducing glutathione (GSH) activity fell to 87.18 %, which cannot offset the production of reactive oxygen species (ROS). Meanwhile, the increasement of lipid peroxidation and malondialdehyde (MDA) levels were observed. The mitochondrial membrane function was also abnormal due to the excessive accumulation of ROS and eventually leads to cell apoptosis and death. At the molecular level, the exposure of BUT could alter the skeleton and secondary structure of bovine serum albumin (BSA) and lysozyme (LYZ), and it could statically quench the intrinsic fluorescence of proteins. The combined experiments confirmed proved the potentially toxic effects of BUT accumulation on the detoxification organ, providing theoretical support for the liver diseases caused by BUT exposure, and a reference for the risk assessment of occupational exposure of BUT.
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Affiliation(s)
- Xinyu Ni
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, PR China
| | - Miao Zhang
- College of Chemistry & Environmental Science, Hebei University, Baoding, Hebei 071002, PR China
| | - Jing Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, PR China
| | - Zhen Zhang
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, PR China
| | - Sijun Dong
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, PR China.
| | - Lining Zhao
- College of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, PR China.
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21
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Kaidow A, Ishii N, Suzuki S, Shiina T, Kasahara H. Reactive oxygen species accumulation is synchronised with growth inhibition of temperature-sensitive recAts polA Escherichia coli. Arch Microbiol 2022; 204:396. [PMID: 35705748 PMCID: PMC9200703 DOI: 10.1007/s00203-022-02957-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/16/2022] [Accepted: 04/28/2022] [Indexed: 11/30/2022]
Abstract
When combined with recombinase defects, chromosome breakage and double-strand break repair deficiencies render cells inviable. However, cells are viable when an SOS response occurs in recAts polA cells in Escherichia coli. Here, we aimed to elucidate the underlying mechanisms of this process. Transposon mutagenesis revealed that the hslO gene, a redox chaperone Hsp33 involved in reactive oxidative species (ROS) metabolism, was required for the suppression of recAts polA lethality at a restricted temperature. Recently, it has been reported that lethal treatments trigger ROS accumulation. We also found that recAts polA cells accumulated ROS at the restricted temperature. A catalase addition to the medium alleviates the temperature sensitivity of recAts polA cells and decreases ROS accumulation. These results suggest that the SOS response and hslO manage oxidative insult to an acceptable level in cells with oxidative damage and rescue cell growth. Overall, ROS might regulate several cellular processes.
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Affiliation(s)
- Akihiro Kaidow
- Department of Biology, School of Biology, Tokai University, Sapporo, 005-8601, Japan.
| | - Noriko Ishii
- Department of Bioscience and Technology, School of Biology, Tokai University, Sapporo, 005-8601, Japan
| | - Sinngo Suzuki
- Department of Molecular Medicine, School of Medicine, Tokai University, Isehara, 259-1193, Japan
| | - Takashi Shiina
- Department of Molecular Medicine, School of Medicine, Tokai University, Isehara, 259-1193, Japan
| | - Hirokazu Kasahara
- Department of Bioscience and Technology, School of Biology, Tokai University, Sapporo, 005-8601, Japan
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22
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Zeng J, Hong Y, Zhao N, Liu Q, Zhu W, Xiao L, Wang W, Chen M, Hong S, Wu L, Xue Y, Wang D, Niu J, Drlica K, Zhao X. A broadly applicable, stress-mediated bacterial death pathway regulated by the phosphotransferase system (PTS) and the cAMP-Crp cascade. Proc Natl Acad Sci U S A 2022; 119:e2118566119. [PMID: 35648826 PMCID: PMC9191683 DOI: 10.1073/pnas.2118566119] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 04/22/2022] [Indexed: 12/30/2022] Open
Abstract
Recent work indicates that killing of bacteria by diverse antimicrobial classes can involve reactive oxygen species (ROS), as if a common, self-destructive response to antibiotics occurs. However, the ROS-bacterial death theory has been challenged. To better understand stress-mediated bacterial death, we enriched spontaneous antideath mutants of Escherichia coli that survive treatment by diverse bactericidal agents that include antibiotics, disinfectants, and environmental stressors, without a priori consideration of ROS. The mutants retained bacteriostatic susceptibility, thereby ruling out resistance. Surprisingly, pan-tolerance arose from carbohydrate metabolism deficiencies in ptsI (phosphotransferase) and cyaA (adenyl cyclase); these genes displayed the activity of upstream regulators of a widely shared, stress-mediated death pathway. The antideath effect was reversed by genetic complementation, exogenous cAMP, or a Crp variant that bypasses cAMP binding for activation. Downstream events comprised a metabolic shift from the TCA cycle to glycolysis and to the pentose phosphate pathway, suppression of stress-mediated ATP surges, and reduced accumulation of ROS. These observations reveal how upstream signals from diverse stress-mediated lesions stimulate shared, late-stage, ROS-mediated events. Cultures of these stable, pan-tolerant mutants grew normally and were therefore distinct from tolerance derived from growth defects described previously. Pan-tolerance raises the potential for unrestricted disinfectant use to contribute to antibiotic tolerance and resistance. It also weakens host defenses, because three agents (hypochlorite, hydrogen peroxide, and low pH) affected by pan-tolerance are used by the immune system to fight infections. Understanding and manipulating the PtsI-CyaA-Crp–mediated death process can help better control pathogens and maintain beneficial microbiota during antimicrobial treatment.
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Affiliation(s)
- Jie Zeng
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Yuzhi Hong
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Institute of Molecular Enzymology and School of Biology & Basic Medical Sciences, Medical College, Soochow University, Suzhou 215123, China
| | - Ningqiu Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Qianyu Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Weiwei Zhu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Lisheng Xiao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Weijie Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Miaomiao Chen
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Shouqiang Hong
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Liwen Wu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Yunxin Xue
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Dai Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Jianjun Niu
- Center of Clinical Laboratory, Zhongshan Hospital, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Karl Drlica
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
| | - Xilin Zhao
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
- Public Health Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
- Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Rutgers University, Newark, NJ 07103
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23
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Ndugire W, Raviranga NGH, Lao J, Ramström O, Yan M. Gold Nanoclusters as Nanoantibiotic Auranofin Analogues. Adv Healthc Mater 2022; 11:e2101032. [PMID: 34350709 PMCID: PMC8816973 DOI: 10.1002/adhm.202101032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/13/2021] [Indexed: 12/21/2022]
Abstract
Auranofin, a gold(I)-complex with tetraacetylated thioglucose (Ac4 GlcSH) and triethylphosphine ligands, is an FDA-approved drug used as an anti-inflammatory aid in the treatment of rheumatoid arthritis. In repurposing auranofin for other diseases, it was found that the drug showed significant activity against Gram-positive but was inactive against Gram-negative bacteria. Herein, the design and synthesis of gold nanoclusters (AuNCs) based on the structural motif of auranofin are reported. Phosphine-capped AuNCs are synthesized and glycosylated, yielding auranofin analogues with mixed triphenylphosphine monosulfonate (TPPMS)/Ac4 GlcSH ligand shells. These AuNCs are active against both Gram-negative and Gram-positive bacteria, including multidrug-resistant pathogens. Notably, an auranofin analogue, a mixed-ligand 1.6 nm AuNC 4b, is more active than auranofin against Pseudomonas aeruginosa, while exhibiting lower toxicity against human A549 cells. The enhanced antibacterial activity of these AuNCs is characterized by a greater uptake of Au by the bacteria compared to AuI complexes. Additional factors include increased oxidative stress, moderate inhibition of thioredoxin reductase (TrxR), and DNA damage. Most intriguingly, the uptake of AuNCs are not affected by the bacterial outer membrane (OM) barrier or by binding with the extracellular proteins. This contrasts with AuI complexes like auranofin that are susceptible to protein binding and hindered by the OM barrier.
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Affiliation(s)
- William Ndugire
- Department of Chemistry, University of Massachusetts Lowell, One University Ave., Lowell, MA, 01854, USA
| | - N G Hasitha Raviranga
- Department of Chemistry, University of Massachusetts Lowell, One University Ave., Lowell, MA, 01854, USA
| | - Jingzhe Lao
- Department of Chemistry, University of Massachusetts Lowell, One University Ave., Lowell, MA, 01854, USA
| | - Olof Ramström
- Department of Chemistry, University of Massachusetts Lowell, One University Ave., Lowell, MA, 01854, USA
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, SE-39182, Sweden
| | - Mingdi Yan
- Department of Chemistry, University of Massachusetts Lowell, One University Ave., Lowell, MA, 01854, USA
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24
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Khan SR, Kuzminov A. Thymine-starvation-induced chromosomal fragmentation is not required for thymineless death in Escherichia coli. Mol Microbiol 2022; 117:1138-1155. [PMID: 35324030 DOI: 10.1111/mmi.14897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 11/29/2022]
Abstract
Thymine or thymidine starvation induces robust chromosomal fragmentation in E. coli thyA deoCABD mutants, and is proposed to be the cause of thymineless death (TLD). However, fragmentation kinetics challenges the idea that fragmentation causes TLD, by peaking before the onset of TLD and disappearing by the time TLD accelerates. Quantity and kinetics of fragmentation also stays unchanged in hyper-TLD-exhibiting recBCD mutant, making its faster and deeper TLD independent of fragmentation as well. Elimination of fragmentation without affecting cellular metabolism did not abolish TLD in the thyA mutant, but reduced early TLD in the thyA recBCD mutant, suggesting replication-dependent, but undetectable by pulsed field gel, double-strand breaks contributed to TLD. Chromosomal fragmentation, but not TLD, was eliminated in both the thyA and thyA recBCD mutants harboring deoCABD operon. Expression of a single gene, deoA, encoding thymidine phosphorylase, was sufficient to abolish fragmentation, suggesting thymidine-to-thymine interconversion during T-starvation being a key factor. Overall, this study reveals that chromosomal fragmentation, a direct consequence of T-starvation, is either dispensable or redundant for the overall TLD pathology, including hyper-TLD in the recBCD mutant. Replication forks, unlike chromosomal fragmentation, may provide minor contribution to TLD, but only in the repair-deficient thyA deoCABD recBCD mutant.
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Affiliation(s)
- Sharik R Khan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Andrei Kuzminov
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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25
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Oxidative damage blocks thymineless death and trimethoprim poisoning in Escherichia coli. J Bacteriol 2021; 204:e0037021. [PMID: 34633866 DOI: 10.1128/jb.00370-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cells that cannot synthesize one of the DNA precursors, dTTP, due to thyA mutation or metabolic poisoning, undergo thymineless death (TLD), - a chromosome-based phenomenon of unclear mechanisms. In E. coli, thymineless death is caused either by denying thyA mutants thymidine supplementation or by treating wild type cells with trimethoprim. Two recent reports promised a potential breakthrough in TLD understanding, suggesting significant oxidative damage during thymine starvation. Oxidative damage in vivo comes from Fenton's reaction, when hydrogen peroxide meets ferrous iron to produce hydroxyl radical. Therefore, TLD could kill via irreparable double-strand breaks behind replication forks, when starvation-caused single-strand DNA gaps are attacked by hydroxyl radicals. We tested the proposed Fenton-TLD connection, in both thyA mutants denied thymidine, as well as in trimethoprim-treated WT cells, under three conditions: 1) intracellular iron chelation; 2) mutational inactivation of hydrogen peroxide (HP) scavenging; 3) acute treatment with sublethal HP concentrations. We found that TLD kinetics are affected by neither iron chelation, nor HP stabilization in cultures, indicating no induction of oxidative damage during thymine starvation. Moreover, acute exogenous HP treatments completely block TLD, apparently by blocking cell division - which may be a novel TLD prerequisite. Separately, the acute trimethoprim sensitivity of the rffC and recBCD mutants demonstrates how bactericidal power of this antibiotic could be amplified by inhibiting the corresponding enzymes. Importance Mysterious thymineless death strikes cells that are starved for thymine and therefore replicating their chromosomal DNA without dTTP. After 67 years of experiments testing various obvious and not so obvious explanations, thymineless death is still without a mechanism. Recently, oxidative damage via in vivo Fenton's reaction was proposed as a critical contributor to the irreparable chromosome damage during thymine starvation. We have tested this idea by either blocking in vivo Fenton's reaction (expecting no thymineless death) or by amplifying oxidative damage (expecting hyper thymineless death). Instead, we found that blocking Fenton's reaction has no influence on thymineless death, while amplifying oxidative damage prevents thymineless death altogether. Thus, oxidative damage does not contribute to thymineless death, while the latter remains enigmatic.
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26
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Wang H, Shang F, Shen J, Xu J, Chen X, Ni J, Yu L, Xue T. LsrR, the effector of AI-2 quorum sensing, is vital for the H 2O 2 stress response in mammary pathogenic Escherichia coli. Vet Res 2021; 52:127. [PMID: 34600565 PMCID: PMC8487509 DOI: 10.1186/s13567-021-00998-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/11/2021] [Indexed: 12/12/2022] Open
Abstract
Mammary pathogenic Escherichia coli (MPEC) is an important causative agent of mastitis in dairy cows that results in reduced milk quality and production, and is responsible for severe economic losses in the dairy industry worldwide. Oxidative stress, as an imbalance between reactive oxygen species (ROS) and antioxidants, is a stress factor that is common in most bacterial habitats. The presence of ROS can damage cellular sites, including iron-sulfur clusters, cysteine and methionine protein residues, and DNA, and may cause bacterial cell death. Previous studies have reported that Autoinducer 2 (AI-2) can regulate E. coli antibiotic resistance and pathogenicity by mediating the intracellular receptor protein LsrR. This study explored the regulatory mechanism of LsrR on the H2O2 stress response in MPEC, showing that the transcript levels of lsrR significantly decreased under H2O2 stress conditions. The survival cell count of lsrR mutant XW10/pSTV28 was increased about 3080-fold when compared with that of the wild-type WT/pSTV28 in the presence of H2O2 and overexpression of lsrR (XW10/pUClsrR) resulted in a decrease in bacterial survival rates under these conditions. The β-galactosidase reporter assays showed that mutation of lsrR led to a remarkable increase in expression of the promoters of ahpCF, katG and oxyR, while lsrR-overexpressing significantly reduced the expression of ahpCF and katG. The electrophoretic mobility shift assays confirmed that LsrR could directly bind to the promoter regions of ahpCF and katG. These results revealed the important role played by LsrR in the oxidative stress response of MPEC.
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Affiliation(s)
- Hui Wang
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jiawei Shen
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jingyi Xu
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Xiaolin Chen
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Jingtian Ni
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China
| | - Lumin Yu
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China. .,Institute of Microbe and Host Health, Linyi University, Linyi, 276005, Shandong, China.
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, 230036, Anhui, China.
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27
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Electron Microscopy Reveals Unexpected Cytoplasm and Envelope Changes during Thymineless Death in Escherichia coli. J Bacteriol 2021; 203:e0015021. [PMID: 34152201 DOI: 10.1128/jb.00150-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial rod-shaped cells experiencing irreparable chromosome damage should filament without other morphological changes. Thymineless death (TLD) strikes thymidine auxotrophs denied external thymine/thymidine (T) supplementation. Such T-starved cells cannot produce the DNA precursor dTTP and therefore stop DNA replication. Stalled replication forks in T-starved cells were always assumed to experience mysterious chromosome lesions, but TLD was recently found to happen even without origin-dependent DNA replication, with the chromosome still remaining the main TLD target. T starvation also induces morphological changes, as if thymidine prevents cell envelope or cytoplasm problems that otherwise translate into chromosome damage. Here, we used transmission electron microscopy (TEM) to examine cytoplasm and envelope changes in T-starved Escherichia coli cells, using treatment with a DNA gyrase inhibitor as a control for "pure" chromosome death. Besides the expected cell filamentation in response to both treatments, we see the following morphological changes specific for T starvation and which might lead to chromosome damage: (i) significant cell widening, (ii) nucleoid diffusion, (iii) cell pole damage, and (iv) formation of numerous cytoplasmic bubbles. We conclude that T starvation does impact both the cytoplasm and the cell envelope in ways that could potentially affect the chromosome. IMPORTANCE Thymineless death is a dramatic and medically important phenomenon, the mechanisms of which remain a mystery. Unlike most other auxotrophs in the absence of the required supplement, thymidine-requiring E. coli mutants not only go static in the absence of thymidine, but rapidly die of chromosomal damage of unclear nature. Since this chromosomal damage is independent of replication, we examined fine morphological changes in cells undergoing thymineless death in order to identify what could potentially affect the chromosome. Here, we report several cytoplasm and cell envelope changes that develop in thymidine-starved cells but not in gyrase inhibitor-treated cells (negative control) that could be linked to subsequent irreparable chromosome damage. This is the first electron microscopy study of cells undergoing "genetic death" due to irreparable chromosome lesions.
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28
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Kim J, Ren D, Gilbert JL. Cytotoxic effect of galvanically coupled magnesium-titanium particles on Escherichia coli. J Biomed Mater Res B Appl Biomater 2021; 109:2162-2173. [PMID: 33979012 DOI: 10.1002/jbm.b.34864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 02/04/2021] [Accepted: 04/28/2021] [Indexed: 11/06/2022]
Abstract
Orthopedic device-related infections (ODRIs) are difficult to control due to microbial biofilm formation and associated with high-level resistance to conventional antibiotics. In many cases, the only treatment option for ODRI is explantation. Previous studies have shown that application of cathodic potentials at the metal surface can eradicate biofilms, and Mg and Mg-Ti particles have the same effect as cathodic potentials. This study investigated the effects of Mg and Mg-Ti particles on established biofilms and planktonic cells E. coli. Bacterial cultures with developed biofilms or planktonic cells were treated with Mg or Mg-Ti particles, and the viability were assessed using flow cytometry or visual assessment methods (i.e., observation from SEM images and opacity of the solution). It was found that viability of biofilms treated with 16.67 mg/ml of Mg was 2.8 ± 0.96% at the end of 6-hr killing compared to untreated controls. This extent of killing was more significant compared to 24-hr grown biofilms treated with ofloxacin, an antibiotic known to be effective against these bacteria. Biofilms treated with 50 and 100 μg/ml of ofloxacin had 62 ± 4.6% and 52 ± 19.3% survival, respectively, where ofloxacin at these concentrations is known to kill planktonic counterparts very effectively. Inhibition zone tests revealed that biofilms within 2 mm of Mg or Mg-Ti particle clusters were effectively killed. These results demonstrated the potential of Mg or Mg-Ti particles in killing microbial biofilms and potential for controlling ODRI.
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Affiliation(s)
- Jua Kim
- Department of Biomedical and Chemical Engineering, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA.,Syracuse Biomaterials Institute, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA.,Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Dacheng Ren
- Department of Biomedical and Chemical Engineering, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA.,Syracuse Biomaterials Institute, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA
| | - Jeremy L Gilbert
- Department of Biomedical and Chemical Engineering, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA.,Syracuse Biomaterials Institute, College of Engineering and Computer Science, Syracuse University, Syracuse, New York, USA.,Department of Bioengineering, Clemson University, Clemson, South Carolina, USA.,Clemson-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
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29
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Shi J, Chen C, Wang D, Tong Z, Wang Z, Liu Y. Amphipathic Peptide Antibiotics with Potent Activity against Multidrug-Resistant Pathogens. Pharmaceutics 2021; 13:438. [PMID: 33804947 PMCID: PMC8063935 DOI: 10.3390/pharmaceutics13040438] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/15/2021] [Accepted: 03/20/2021] [Indexed: 11/16/2022] Open
Abstract
The emergence and prevalence of multidrug-resistant (MDR) bacteria have posed a serious threat to public health. Of particular concern are methicillin-resistant Staphylococcus aureus (MRSA) and blaNDM, mcr-1 and tet(X)-positive Gram-negative pathogens. The fact that few new antibiotics have been approved in recent years exacerbates this global crisis, thus, new alternatives are urgently needed. Antimicrobial peptides (AMPs) originated from host defense peptides with a wide range of sources and multiple functions, are less prone to achieve resistance. All these characteristics laid the foundation for AMPs to become potential antibiotic candidates. In this study, we revealed that peptide WW307 displayed potent antibacterial and bactericidal activity against MDR bacteria, including MRSA and Gram-negative bacteria carrying blaNDM-5, mcr-1 or tet(X4). In addition, WW307 exhibited great biofilm inhibition and eradication activity. Safety and stability experiments showed that WW307 had a strong resistance against various physiological conditions and displayed relatively low toxicity. Mechanistic experiments showed that WW307 resulted in membrane damage by selectively targeting bacterial membrane-specific components, including lipopolysaccharide (LPS), phosphatidylglycerol (PG), and cardiolipin (CL). Moreover, WW307 dissipated membrane potential and triggered the production of reactive oxygen species (ROS). Collectively, these results demonstrated that WW307 represents a promising candidate for combating MDR pathogens.
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Affiliation(s)
- Jingru Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
| | - Chen Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
| | - Dejuan Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
| | - Ziwen Tong
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
| | - Zhiqiang Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Yuan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; (J.S.); (C.C.); (D.W.); (Z.T.)
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
- Institute of Comparative Medicine, Yangzhou University, Yangzhou 225009, China
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30
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Abstract
Nucleotide metabolism plays a central role in bacterial physiology, producing the nucleic acids necessary for DNA replication and RNA transcription. Recent studies demonstrate that nucleotide metabolism also proactively contributes to antibiotic-induced lethality in bacterial pathogens and that disruptions to nucleotide metabolism contributes to antibiotic treatment failure in the clinic. As antimicrobial resistance continues to grow unchecked, new approaches are needed to study the molecular mechanisms responsible for antibiotic efficacy. Here we review emerging technologies poised to transform understanding into why antibiotics may fail in the clinic. We discuss how these technologies led to the discovery that nucleotide metabolism regulates antibiotic drug responses and why these are relevant to human infections. We highlight opportunities for how studies into nucleotide metabolism may enhance understanding of antibiotic failure mechanisms.
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Affiliation(s)
- Allison J Lopatkin
- Department of Biology, Barnard College, New York, NY, United States.,Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY, United States.,Data Science Institute, Columbia University, New York, NY, United States
| | - Jason H Yang
- Ruy V. Lourenço Center for Emerging and Re-emerging Pathogens, Rutgers New Jersey Medical School, Newark, NJ, United States.,Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, United States
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31
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Degradation of the Escherichia coli Essential Proteins DapB and Dxr Results in Oxidative Stress, which Contributes to Lethality through Incomplete Base Excision Repair. mBio 2021; 13:e0375621. [PMID: 35130721 PMCID: PMC8822343 DOI: 10.1128/mbio.03756-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Various lethal stresses, including bactericidal antibiotics, can trigger the production of reactive oxygen species (ROS) that contribute to killing. Incomplete base excision repair (BER) of oxidized nucleotides, especially 8-oxo-dG, has been identified as a major component of ROS-induced lethality. However, the relative contributions of this pathway to death vary widely between stresses, due in part to poorly understood complex differences in the physiological changes caused by these stresses. To identify new lethal stresses that kill cells through this pathway, we screened an essential protein degradation library and found that depletion of either DapB or Dxr leads to cell death through incomplete BER; the contribution of this pathway to overall cell death is greater for DapB than for Dxr. Depletion of either protein generates oxidative stress, which increases incorporation of 8-oxo-dG into the genome. This oxidative stress is causally related to cell death, as plating on an antioxidant provided a protective effect. Moreover, incomplete BER was central to this cell death, as mutants lacking the key BER DNA glycosylases MutM and MutY were less susceptible, while overexpression of the nucleotide sanitizer MutT, which degrades 8-oxo-dGTP to prevent its incorporation, was protective. RNA sequencing of cells depleted of these proteins revealed widely different transcriptional responses to these stresses. Our discovery that oxidative stress-induced incomplete BER is highly dependent on the exact physiological changes that the cell experiences helps explain the past confusion that arose concerning the role of ROS in antibiotic lethality. IMPORTANCE Bacterial cell death is a poorly understood process. The generation of reactive oxygen species (ROS) is an apparently common response to challenges by a wide variety of lethal stresses, including bactericidal antibiotics. Incomplete BER of nucleotides damaged by these ROS, especially 8-oxo-dG, is a significant contributing factor to this lethality, but the levels of its contribution vary widely between different lethal stresses. A better understanding of the conditions that cause cells to die because of incomplete BER may lead to improved strategies for targeting this mode of death as an adjunct to antimicrobial therapy.
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32
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Bush NG, Diez-Santos I, Abbott LR, Maxwell A. Quinolones: Mechanism, Lethality and Their Contributions to Antibiotic Resistance. Molecules 2020; 25:E5662. [PMID: 33271787 PMCID: PMC7730664 DOI: 10.3390/molecules25235662] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 12/05/2022] Open
Abstract
Fluoroquinolones (FQs) are arguably among the most successful antibiotics of recent times. They have enjoyed over 30 years of clinical usage and become essential tools in the armoury of clinical treatments. FQs target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, where they stabilise a covalent enzyme-DNA complex in which the DNA is cleaved in both strands. This leads to cell death and turns out to be a very effective way of killing bacteria. However, resistance to FQs is increasingly problematic, and alternative compounds are urgently needed. Here, we review the mechanisms of action of FQs and discuss the potential pathways leading to cell death. We also discuss quinolone resistance and how quinolone treatment can lead to resistance to non-quinolone antibiotics.
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Affiliation(s)
| | | | | | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK; (N.G.B.); (I.D.-S.); (L.R.A.)
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33
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Foret MK, Lincoln R, Do Carmo S, Cuello AC, Cosa G. Connecting the "Dots": From Free Radical Lipid Autoxidation to Cell Pathology and Disease. Chem Rev 2020; 120:12757-12787. [PMID: 33211489 DOI: 10.1021/acs.chemrev.0c00761] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Our understanding of lipid peroxidation in biology and medicine is rapidly evolving, as it is increasingly implicated in various diseases but also recognized as a key part of normal cell function, signaling, and death (ferroptosis). Not surprisingly, the root and consequences of lipid peroxidation have garnered increasing attention from multiple disciplines in recent years. Here we "connect the dots" between the fundamental chemistry underpinning the cascade reactions of lipid peroxidation (enzymatic or free radical), the reactive nature of the products formed (lipid-derived electrophiles), and the biological targets and mechanisms associated with these products that culminate in cellular responses. We additionally bring light to the use of highly sensitive, fluorescence-based methodologies. Stemming from the foundational concepts in chemistry and biology, these methodologies enable visualizing and quantifying each reaction in the cascade in a cellular and ultimately tissue context, toward deciphering the connections between the chemistry and physiology of lipid peroxidation. The review offers a platform in which the chemistry and biomedical research communities can access a comprehensive summary of fundamental concepts regarding lipid peroxidation, experimental tools for the study of such processes, as well as the recent discoveries by leading investigators with an emphasis on significant open questions.
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Affiliation(s)
- Morgan K Foret
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Richard Lincoln
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
| | - Sonia Do Carmo
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6.,Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 0C7.,Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Gonzalo Cosa
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 0B8
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34
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Drlica K, Zhao X. Bacterial death from treatment with fluoroquinolones and other lethal stressors. Expert Rev Anti Infect Ther 2020; 19:601-618. [PMID: 33081547 DOI: 10.1080/14787210.2021.1840353] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Lethal stressors, including antimicrobials, kill bacteria in part through a metabolic response proposed to involve reactive oxygen species (ROS). The quinolone anti-bacterials have served as key experimental tools in developing this idea. AREAS COVERED Bacteriostatic and bactericidal action of quinolones are distinguished, with emphasis on the contribution of chromosome fragmentation and ROS accumulation to bacterial death. Action of non-quinolone antibacterials and non-antimicrobial stressors is described to provide a general framework for understanding stress-mediated, bacterial death. EXPERT OPINION Quinolones trap topoisomerases on DNA in reversible complexes that block DNA replication and bacterial growth. At elevated drug concentrations, DNA ends are released from topoisomerase-mediated constraint, leading to the idea that death arises from chromosome fragmentation. However, DNA ends also stimulate repair, which is energetically expensive. An incompletely understood metabolic shift occurs, and ROS accumulate. Even after quinolone removal, ROS continue to amplify, generating secondary and tertiary damage that overwhelms repair and causes death. Repair may also contribute to death directly via DNA breaks arising from incomplete base-excision repair of ROS-oxidized nucleotides. Remarkably, perturbations that interfere with ROS accumulation confer tolerance to many diverse lethal agents.
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Affiliation(s)
| | - Xilin Zhao
- Rutgers University, Newark, NJ, USA.,State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, South Xiang-An Road, Xiang-An District, Xiamen, Fujian Province, China
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35
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Revitt-Mills SA, Robinson A. Antibiotic-Induced Mutagenesis: Under the Microscope. Front Microbiol 2020; 11:585175. [PMID: 33193230 PMCID: PMC7642495 DOI: 10.3389/fmicb.2020.585175] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/28/2020] [Indexed: 11/24/2022] Open
Abstract
The development of antibiotic resistance poses an increasing threat to global health. Understanding how resistance develops in bacteria is critical for the advancement of new strategies to combat antibiotic resistance. In the 1980s, it was discovered that certain antibiotics induce elevated rates of mutation in bacteria. From this, an “increased evolvability” hypothesis was proposed: antibiotic-induced mutagenesis increases the genetic diversity of bacterial populations, thereby increasing the rate at which bacteria develop antibiotic resistance. However, antibiotic-induced mutagenesis is one of multiple competing factors that act on bacterial populations exposed to antibiotics. Its relative importance in shaping evolutionary outcomes, including the development of antibiotic resistance, is likely to depend strongly on the conditions. Presently, there is no quantitative model that describes the relative contribution of antibiotic-induced mutagenesis to bacterial evolution. A far more complete understanding could be reached if we had access to technology that enabled us to study antibiotic-induced mutagenesis at the molecular-, cellular-, and population-levels simultaneously. Direct observations would, in principle, allow us to directly link molecular-level events with outcomes in individual cells and cell populations. In this review, we highlight microscopy studies which have allowed various aspects of antibiotic-induced mutagenesis to be directly visualized in individual cells for the first time. These studies have revealed new links between error-prone DNA polymerases and recombinational DNA repair, evidence of spatial regulation occurring during the SOS response, and enabled real-time readouts of mismatch and mutation rates. Further, we summarize the recent discovery of stochastic population fluctuations in cultures exposed to sub-inhibitory concentrations of bactericidal antibiotics and discuss the implications of this finding for the study of antibiotic-induced mutagenesis. The studies featured here demonstrate the potential of microscopy to provide direct observation of phenomena relevant to evolution under antibiotic-induced mutagenesis.
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Affiliation(s)
- Sarah A Revitt-Mills
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Andrew Robinson
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
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Kawano A, Yamasaki R, Sakakura T, Takatsuji Y, Haruyama T, Yoshioka Y, Ariyoshi W. Reactive Oxygen Species Penetrate Persister Cell Membranes of Escherichia coli for Effective Cell Killing. Front Cell Infect Microbiol 2020; 10:496. [PMID: 33042869 PMCID: PMC7530241 DOI: 10.3389/fcimb.2020.00496] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 08/10/2020] [Indexed: 02/05/2023] Open
Abstract
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.
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Affiliation(s)
- Aki Kawano
- Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
| | - Ryota Yamasaki
- Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
| | - Tatsuya Sakakura
- Division of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Yoshiyuki Takatsuji
- Division of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Tetsuya Haruyama
- Division of Functional Interface Engineering, Department of Biological Systems and Engineering, Kyushu Institute of Technology, Kitakyushu, Japan
| | - Yoshie Yoshioka
- Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
| | - Wataru Ariyoshi
- Division of Infections and Molecular Biology, Department of Health Promotion, Kyushu Dental University, Kitakyushu, Japan
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Martínez SR, Durantini AM, Becerra MC, Cosa G. Real-Time Single-Cell Imaging Reveals Accelerating Lipid Peroxyl Radical Formation in Escherichia coli Triggered by a Fluoroquinolone Antibiotic. ACS Infect Dis 2020; 6:2468-2477. [PMID: 32786297 DOI: 10.1021/acsinfecdis.0c00317] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The formation of reactive oxygen species (ROS) induced by bactericidal antibiotics has been associated with a common, nonspecific mechanism of cellular death. Herein, we report real-time single-cell fluorescence studies on Escherichia coli stained with a fluorogenic probe for lipid peroxyl radicals showing the generation of this form of ROS when exposed to the minimum inhibitory concentration (MIC) and 10× MIC of the fluoroquinolone antibiotic ciprofloxacin (3 and 30 μM, respectively). Single-cell intensity-time trajectories show an induction period followed by an accelerating phase for cells treated with antibiotic, where initial and maximum intensity achieved following 3.5 h of incubation with antibiotic showed dose-dependent average values. A large fraction of bacteria remains viable after the studies, indicating ROS formation is occurring a priori of cell death. Punctate structures are observed, consistent with membrane blebbing. The addition of a membrane embedding lipid peroxyl radical scavenger, an α-tocopherol analogue, to the media increased the MIC of ciprofloxacin. Lipid peroxyl radical formation precedes E. coli cell death and may be invoked in a cascade event including membrane disruption and consequent cell wall permeabilization. Altogether, our work illustrates that lipid peroxidation is caused by ciprofloxacin in E. coli and suppressed by α-tocopherol analogues. Lipid peroxidation may be invoked in a cascade event including membrane disruption and consequent cell wall permeabilization. Our work provides a methodology to assess antibiotic-induced membrane peroxidation at the single-cell level; this methodology provides opportunities to explore the scope and nature of lipid peroxidation in antibiotic-induced cell lethality.
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Affiliation(s)
- Sol R. Martínez
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
- IMBIV-CONICET and Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Quı́micas, Universidad Nacional de Córdoba, Haya de la Torre S/N, Córdoba X5000, Argentina
| | - Andrés M. Durantini
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
| | - María C. Becerra
- IMBIV-CONICET and Departamento de Ciencias Farmacéuticas, Facultad de Ciencias Quı́micas, Universidad Nacional de Córdoba, Haya de la Torre S/N, Córdoba X5000, Argentina
| | - Gonzalo Cosa
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada
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Henrikus SS, Henry C, McGrath AE, Jergic S, McDonald J, Hellmich Y, Bruckbauer ST, Ritger ML, Cherry M, Wood EA, Pham PT, Goodman MF, Woodgate R, Cox MM, van Oijen AM, Ghodke H, Robinson A. Single-molecule live-cell imaging reveals RecB-dependent function of DNA polymerase IV in double strand break repair. Nucleic Acids Res 2020; 48:8490-8508. [PMID: 32687193 PMCID: PMC7470938 DOI: 10.1093/nar/gkaa597] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 06/30/2020] [Accepted: 07/16/2020] [Indexed: 01/09/2023] Open
Abstract
Several functions have been proposed for the Escherichia coli DNA polymerase IV (pol IV). Although much research has focused on a potential role for pol IV in assisting pol III replisomes in the bypass of lesions, pol IV is rarely found at the replication fork in vivo. Pol IV is expressed at increased levels in E. coli cells exposed to exogenous DNA damaging agents, including many commonly used antibiotics. Here we present live-cell single-molecule microscopy measurements indicating that double-strand breaks induced by antibiotics strongly stimulate pol IV activity. Exposure to the antibiotics ciprofloxacin and trimethoprim leads to the formation of double strand breaks in E. coli cells. RecA and pol IV foci increase after treatment and exhibit strong colocalization. The induction of the SOS response, the appearance of RecA foci, the appearance of pol IV foci and RecA-pol IV colocalization are all dependent on RecB function. The positioning of pol IV foci likely reflects a physical interaction with the RecA* nucleoprotein filaments that has been detected previously in vitro. Our observations provide an in vivo substantiation of a direct role for pol IV in double strand break repair in cells treated with double strand break-inducing antibiotics.
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Affiliation(s)
- Sarah S Henrikus
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Camille Henry
- Department of Biochemistry, University of Wisconsin-Madison, WI 53706, USA
| | - Amy E McGrath
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Slobodan Jergic
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - John P McDonald
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yvonne Hellmich
- Institute of Biochemistry, Goethe Universität, Frankfurt 3MR4+W2, Germany
| | | | - Matthew L Ritger
- Department of Biochemistry, University of Wisconsin-Madison, WI 53706, USA
| | - Megan E Cherry
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Elizabeth A Wood
- Department of Biochemistry, University of Wisconsin-Madison, WI 53706, USA
| | - Phuong T Pham
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Myron F Goodman
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Roger Woodgate
- Laboratory of Genomic Integrity, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael M Cox
- Department of Biochemistry, University of Wisconsin-Madison, WI 53706, USA
| | - Antoine M van Oijen
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Harshad Ghodke
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Andrew Robinson
- Molecular Horizons Institute and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
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Li Y, Xu X, Liu X, Li B, Han Y, Zheng Y, Chen D, Yeung KWK, Cui Z, Li Z, Liang Y, Zhu S, Wang X, Wu S. Photoelectrons Mediating Angiogenesis and Immunotherapy through Heterojunction Film for Noninvasive Disinfection. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000023. [PMID: 32999817 PMCID: PMC7507565 DOI: 10.1002/advs.202000023] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 05/31/2020] [Indexed: 05/23/2023]
Abstract
A light-inspired hydroxyapatite (Hap)/nitrogen-doped carbon dots (NCDs) modified graphene oxide (GO) heterojunction film is developed, which shows a promoted separation of interfacial electrons and holes and an inhibited recombination efficiency via hole depletion. The metabolism of bacteria on this film is significantly inhibited under light irradiation, due to the enhanced photocatalytic and photothermal effects. In addition, the electron transfer from the plasmonic membrane to the GO/NCD/Hap film further inhibits the adenosine triphosphate process of bacteria, thus leading to the synergetic antibacterial efficacy. Meanwhile, the electron transfer between film and cell membrane induces the Ca2+ flow after irradiation, which can promote the migration and proliferation of cells and alkaline phosphatase enhancement, thus favoring the tissue reconstruction. An in vivo test discloses that the vascular injury repair is achieved through the Ca2+-activated PLCγ1/ERK pathway, identified by the enhanced CD31 expression. Moreover, the increased CD4+/CD8+ lymphocytes are ameliorative by activating the PI3K/P-AKT pathway. Consequently, the electron transfer boosts the synergic photodynamic and photothermal therapeutic effects for bacterial infection by Ca2+ flow for immunotherapy. This mild phototherapy approach with GO/NCDs/Hap, which can simultaneously repair injured vessels and relieve inflammation reactions, will increase the clinical application of noninvasive phototherapy in the near future.
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Affiliation(s)
- Yuan Li
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
| | - Xiaomo Xu
- Hubei Key Laboratory of Polymer MaterialsMinistry‐of‐Education Key Laboratory for the Green Preparation and Application of Functional MaterialsSchool of Materials Science and EngineeringHubei UniversityWuhan430062China
| | - Xiangmei Liu
- Hubei Key Laboratory of Polymer MaterialsMinistry‐of‐Education Key Laboratory for the Green Preparation and Application of Functional MaterialsSchool of Materials Science and EngineeringHubei UniversityWuhan430062China
| | - Bo Li
- State Key Laboratory for Mechanical Behavior of MaterialsSchool of Materials Science and EngineeringXi'an Jiaotong UniversityXi'anShaanxi710049China
| | - Yong Han
- State Key Laboratory for Mechanical Behavior of MaterialsSchool of Materials Science and EngineeringXi'an Jiaotong UniversityXi'anShaanxi710049China
| | - Yufeng Zheng
- State Key Laboratory for Turbulence and Complex SystemDepartment of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing100871China
| | - Da‐fu Chen
- Laboratory Bone Tissue EngineeringBeijing Research Institute Orthopaedics and TraumatologyBeijing JiShuiTan HospitalBeijing100035P. R. China
| | - Kelvin Wai Kwok Yeung
- Department of Orthopaedics and TraumatologyLi Ka Shing Faculty of MedicineThe University of Hong KongPokfulamHong Kong999077China
| | - Zhenduo Cui
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
| | - Zhaoyang Li
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
| | - Yanqin Liang
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
| | - Shengli Zhu
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
| | - Xianbao Wang
- Hubei Key Laboratory of Polymer MaterialsMinistry‐of‐Education Key Laboratory for the Green Preparation and Application of Functional MaterialsSchool of Materials Science and EngineeringHubei UniversityWuhan430062China
| | - Shuilin Wu
- The Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of ChinaSchool of Materials Science and EngineeringTianjin UniversityTianjin300072China
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40
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Liu Y, Yang K, Jia Y, Shi J, Tong Z, Wang Z. Cysteine Potentiates Bactericidal Antibiotics Activity Against Gram-Negative Bacterial Persisters. Infect Drug Resist 2020; 13:2593-2599. [PMID: 32801796 PMCID: PMC7397215 DOI: 10.2147/idr.s263225] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/16/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose Bacterial metabolism regulators offer a novel productive strategy in the eradication of antibiotic refractory bacteria, particularly bacterial persisters. However, the potential of amino acids in the fight against Gram-negative bacterial persisters has not been fully explored. The aim of this study is to investigate the potentiation of amino acids to antibiotics in combating Gram-negative bacterial persisters and to reveal the underlying mechanisms of action. Methods Bactericidal activity of antibiotics in the absence or presence of amino acids was evaluated through detecting the reduction of bacterial CFUs. The ratio of NAD+/NADH in E. coli B2 persisters was determined using assay kit with WST-8. Bacterial respiration and ROS production were measured by the reduction of iodonitrotetrazolium chloride and fluorescent probe 2′,7′-dichlorodihydrofluorescein diacetate, respectively. Results In this study, we found that cysteine possesses excellent synergistic bactericidal activity with ciprofloxacin against multiple Gram-negative bacterial persisters. Furthermore, the potentiation of cysteine was evaluated in exponential and stationary-phase E. coli ATCC 25922 and E. coli B2. Interestingly, cysteine significantly improves three bactericidal antibiotics killing against stationary-phase bacteria, but not exponential-phase bacteria, implying that the effect of cysteine correlates with the metabolic state of bacteria. Mechanistic studies revealed that cysteine accelerates the bacterial TCA cycle and promotes bacterial respiration and ROS production. These metabolic regulation effects of cysteine re-sensitive bacterial persisters to antibiotic killing. Conclusion Collectively, our study highlights the synergistic bactericidal activity of bacterial metabolism regulators such as cysteine with commonly used antibiotics against Gram-negative bacterial persisters.
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Affiliation(s)
- Yuan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.,Institute of Comparative Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
| | - Kangni Yang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
| | - Yuqian Jia
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
| | - Jingru Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
| | - Ziwen Tong
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
| | - Zhiqiang Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China.,Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, People's Republic of China
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41
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Frandi A, Collier J. HdaB: a novel and conserved DnaA-related protein that targets the RIDA process to stimulate replication initiation. Nucleic Acids Res 2020; 48:2412-2423. [PMID: 31875223 PMCID: PMC7049699 DOI: 10.1093/nar/gkz1193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 12/03/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022] Open
Abstract
Exquisite control of the DnaA initiator is critical to ensure that bacteria initiate chromosome replication in a cell cycle-coordinated manner. In many bacteria, the DnaA-related and replisome-associated Hda/HdaA protein interacts with DnaA to trigger the Regulatory Inactivation of DnaA (RIDA) and prevent over-initiation events. In the Caulobacter crescentus Alphaproteobacterium, the RIDA process also targets DnaA for its rapid proteolysis by Lon. The impact of the RIDA process on adaptation of bacteria to changing environments remains unexplored. Here, we identify a novel and conserved DnaA-related protein, named HdaB, and show that homologs from three different Alphaproteobacteria can inhibit the RIDA process, leading to over-initiation and cell death when expressed in actively growing C. crescentus cells. We further show that HdaB interacts with HdaA in vivo, most likely titrating HdaA away from DnaA. Strikingly, we find that HdaB accumulates mainly during stationary phase and that it shortens the lag phase upon exit from stationary phase. Altogether, these findings suggest that expression of hdaB during stationary phase prepares cells to restart the replication of their chromosome as soon as conditions improve, a situation often met by free-living or facultative intracellular Alphaproteobacteria.
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Affiliation(s)
- Antonio Frandi
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH-1015, Switzerland
| | - Justine Collier
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne CH-1015, Switzerland
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42
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Nitrogen starvation reveals the mitotic potential of mutants in the S/MAPK pathways. Nat Commun 2020; 11:1973. [PMID: 32332728 PMCID: PMC7181643 DOI: 10.1038/s41467-020-15880-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 03/24/2020] [Indexed: 02/08/2023] Open
Abstract
The genetics of quiescence is an emerging field compared to that of growth, yet both states generate spontaneous mutations and genetic diversity fueling evolution. Reconciling mutation rates in dividing conditions and mutation accumulation as a function of time in non-dividing situations remains a challenge. Nitrogen-starved fission yeast cells reversibly arrest proliferation, are metabolically active and highly resistant to a variety of stresses. Here, we show that mutations in stress- and mitogen-activated protein kinase (S/MAPK) signaling pathways are enriched in aging cultures. Targeted resequencing and competition experiments indicate that these mutants arise in the first month of quiescence and expand clonally during the second month at the expense of the parental population. Reconstitution experiments show that S/MAPK modules mediate the sacrifice of many cells for the benefit of some mutants. These findings suggest that non-dividing conditions promote genetic diversity to generate a social cellular environment prone to kin selection. Nitrogen-starved fission yeast cells survive for weeks without dividing. Here, the authors show that some of these surviving cells accumulate mutations in the stress- and mitogen-activated protein kinase pathways and outcompete their parental cells, which provide nutrients for the mutant cells.
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Lam PL, Wong RSM, Lam KH, Hung LK, Wong MM, Yung LH, Ho YW, Wong WY, Hau DKP, Gambari R, Chui CH. The role of reactive oxygen species in the biological activity of antimicrobial agents: An updated mini review. Chem Biol Interact 2020; 320:109023. [PMID: 32097615 DOI: 10.1016/j.cbi.2020.109023] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/18/2020] [Accepted: 02/21/2020] [Indexed: 01/07/2023]
Abstract
Antimicrobial resistance remains a serious problem that results in high mortality and increased healthcare costs globally. One of the major issues is that resistant pathogens decrease the efficacy of conventional antimicrobials. Accordingly, development of novel antimicrobial agents and therapeutic strategies is urgently needed to overcome the challenge of antimicrobial resistance. A potential strategy is to kill pathogenic microorganisms via the formation of reactive oxygen species (ROS). ROS are defined as a number of highly reactive molecules that comprise molecular oxygen (O2), superoxide anion (O2•-), hydrogen peroxide (H2O2) and hydroxyl radicals (•OH). ROS exhibit antimicrobial actions against a broad range of pathogens through the induction of oxidative stress, which is an imbalance between ROS and the ability of the antioxidant defence system to detoxify ROS. ROS-dependent oxidative stress can damage cellular macromolecules, including DNA, lipids and proteins. This article reviews the antimicrobial action of ROS, challenges to ROS hypothesis, work to solidify ROS-mediated antimicrobial lethality hypothesis, recent developments in antimicrobial agents using ROS as an antimicrobial strategy, safety concerns related to ROS, and future directions in ROS research.
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Affiliation(s)
- P-L Lam
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - R S-M Wong
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
| | - K-H Lam
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - L-K Hung
- Research and Development Division, Kamford Genetics Company Limited, Hong Kong, China
| | - M-M Wong
- Research and Development Division, Kamford Genetics Company Limited, Hong Kong, China
| | - L-H Yung
- Research and Development Division, Kamford Genetics Company Limited, Hong Kong, China
| | - Y-W Ho
- Allways Health Care Medical Centre, Tsuen Wan, Hong Kong, China
| | - W-Y Wong
- State Key Laboratory of Chemical Biology and Drug Discovery and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
| | - D K-P Hau
- One Health International Limited, Shatin, Hong Kong, China.
| | - R Gambari
- Department of Life Sciences and Biotechnology, Section of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy.
| | - C-H Chui
- Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China; Research and Development Division, Kamford Genetics Company Limited, Hong Kong, China.
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Martin HA, Kidman AA, Socea J, Vallin C, Pedraza-Reyes M, Robleto EA. The Bacillus Subtilis K-State Promotes Stationary-Phase Mutagenesis via Oxidative Damage. Genes (Basel) 2020; 11:genes11020190. [PMID: 32053972 PMCID: PMC7073564 DOI: 10.3390/genes11020190] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 02/05/2020] [Accepted: 02/06/2020] [Indexed: 12/12/2022] Open
Abstract
Bacterial cells develop mutations in the absence of cellular division through a process known as stationary-phase or stress-induced mutagenesis. This phenomenon has been studied in a few bacterial models, including Escherichia coli and Bacillus subtilis; however, the underlying mechanisms between these systems differ. For instance, RecA is not required for stationary-phase mutagenesis in B. subtilis like it is in E. coli. In B. subtilis, RecA is essential to the process of genetic transformation in the subpopulation of cells that become naturally competent in conditions of stress. Interestingly, the transcriptional regulator ComK, which controls the development of competence, does influence the accumulation of mutations in stationary phase in B. subtilis. Since recombination is not involved in this process even though ComK is, we investigated if the development of a subpopulation (K-cells) could be involved in stationary-phase mutagenesis. Using genetic knockout strains and a point-mutation reversion system, we investigated the effects of ComK, ComEA (a protein involved in DNA transport during transformation), and oxidative damage on stationary-phase mutagenesis. We found that stationary-phase revertants were more likely to have undergone the development of competence than the background of non-revertant cells, mutations accumulated independently of DNA uptake, and the presence of exogenous oxidants potentiated mutagenesis in K-cells. Therefore, the development of the K-state creates conditions favorable to an increase in the genetic diversity of the population not only through exogenous DNA uptake but also through stationary-phase mutagenesis.
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Affiliation(s)
- Holly A. Martin
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA; (H.A.M.); (A.A.K.); (J.S.); (C.V.)
| | - Amanda A. Kidman
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA; (H.A.M.); (A.A.K.); (J.S.); (C.V.)
| | - Jillian Socea
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA; (H.A.M.); (A.A.K.); (J.S.); (C.V.)
| | - Carmen Vallin
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA; (H.A.M.); (A.A.K.); (J.S.); (C.V.)
| | - Mario Pedraza-Reyes
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, P.O. Box 187, Guanajuato Gto. 36050, Mexico;
| | - Eduardo A. Robleto
- University of Nevada, Las Vegas, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA; (H.A.M.); (A.A.K.); (J.S.); (C.V.)
- Correspondence: ; Tel.: +1-702-895-2496
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Kim D, Byun J, Park J, Lee Y, Shim G, Oh YK. Biomimetic polymeric nanoparticle-based photodynamic immunotherapy and protection against tumor rechallenge. Biomater Sci 2020; 8:1106-1116. [DOI: 10.1039/c9bm01704f] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this study, we sought to design a bionanomaterial that could exert anticancer effects against primary tumors and protect against rechallenged tumorsviaphotodynamic immunotherapy.
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Affiliation(s)
- Dongyoon Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Junho Byun
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Jinwon Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Yeon Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Gayong Shim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Yu-Kyoung Oh
- College of Pharmacy and Research Institute of Pharmaceutical Sciences
- Seoul National University
- Seoul 08826
- Republic of Korea
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Hong Y, Li Q, Gao Q, Xie J, Huang H, Drlica K, Zhao X. Reactive oxygen species play a dominant role in all pathways of rapid quinolone-mediated killing. J Antimicrob Chemother 2019; 75:576-585. [DOI: 10.1093/jac/dkz485] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 10/22/2019] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Quinolones have been thought to rapidly kill bacteria in two ways: (i) quinolone-topoisomerase-DNA lesions stimulate the accumulation of toxic reactive oxygen species (ROS); and (ii) the lesions directly cause lethal DNA breaks. Traditional killing assays may have underestimated the ROS contribution by overlooking the possibility that ROS continue to accumulate and kill cells on drug-free agar after quinolone removal.
Methods
Quinolone-induced, ROS-mediated killing of Escherichia coli was measured by plating post-treatment samples on agar with/without anti-ROS agents.
Results
When E. coli cultures were treated with ciprofloxacin or moxifloxacin in the presence of chloramphenicol (to accentuate DNA-break-mediated killing), lethal activity, revealed by plating on quinolone-free agar, was inhibited by supplementing agar with ROS-mitigating agents. Moreover, norfloxacin-mediated lethality, observed with cells suspended in saline, was blocked by inhibitors of ROS accumulation and exacerbated by a katG catalase deficiency that impairs peroxide detoxification. Unlike WT cells, the katG mutant was killed by nalidixic acid or norfloxacin with chloramphenicol present and by nalidixic or oxolinic acid with cells suspended in saline. ROS accumulated after quinolone removal with cultures either co-treated with chloramphenicol or suspended in saline. Deficiencies in recA or recB reduced the protective effects of ROS-mitigating agents, supporting the idea that repair of quinolone-mediated DNA lesions suppresses the direct lethal effects of such lesions.
Conclusions
ROS are the dominant factor in all modes of quinolone-mediated lethality, as quinolone-mediated primary DNA lesions are insufficient to kill without triggering ROS accumulation. ROS-stimulating adjuvants may enhance the lethality of quinolones and perhaps other antimicrobials.
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Affiliation(s)
- Yuzhi Hong
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 07103, USA
| | - Qiming Li
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 07103, USA
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400715, China
| | - Qiong Gao
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 07103, USA
- Institute of Antibiotics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Ministry of Education Eco-Environment of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, 1 Tiansheng Road, Beibei District, Chongqing 400715, China
| | - Haihui Huang
- Institute of Antibiotics, Huashan Hospital, Fudan University, 12 Middle Wulumuqi Road, Shanghai 200040, China
| | - Karl Drlica
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 07103, USA
| | - Xilin Zhao
- Public Health Research Institute and Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ 07103, USA
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, 4221-117 South Xiang-An Road, Xiang-An District, Xiamen, Fujian Province 361102, China
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Weissman JL, Fagan WF, Johnson PLF. Linking high GC content to the repair of double strand breaks in prokaryotic genomes. PLoS Genet 2019; 15:e1008493. [PMID: 31703064 PMCID: PMC6867656 DOI: 10.1371/journal.pgen.1008493] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/20/2019] [Accepted: 10/25/2019] [Indexed: 01/21/2023] Open
Abstract
Genomic GC content varies widely among microbes for reasons unknown. While mutation bias partially explains this variation, prokaryotes near-universally have a higher GC content than predicted solely by this bias. Debate surrounds the relative importance of the remaining explanations of selection versus biased gene conversion favoring GC alleles. Some environments (e.g. soils) are associated with a high genomic GC content of their inhabitants, which implies that either high GC content is a selective adaptation to particular habitats, or that certain habitats favor increased rates of gene conversion. Here, we report a novel association between the presence of the non-homologous end joining DNA double-strand break repair pathway and GC content; this observation suggests that DNA damage may be a fundamental driver of GC content, leading in part to the many environmental patterns observed to-date. We discuss potential mechanisms accounting for the observed association, and provide preliminary evidence that sites experiencing higher rates of double-strand breaks are under selection for increased GC content relative to the genomic background. The overall nucleotide composition of an organism’s genome varies greatly between species. Previous work has identified certain environmental factors (e.g., oxygen availability) associated with the relative number of GC bases as opposed to AT bases in the genomes of species. Many of these environments that are associated with high GC content are also associated with relatively high rates of DNA damage. We show that organisms possessing the non-homologous end-joining DNA repair pathway, which is one mechanism to repair DNA double-strand breaks, have an elevated GC content relative to expectation. We also show that certain sites on the genome that are particularly susceptible to double strand breaks have an elevated GC content. This leads us to suggest that an important underlying driver of variability in nucleotide composition across environments is the rate of DNA damage (specifically double-strand breaks) to which an organism living in each environment is exposed.
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Affiliation(s)
- JL Weissman
- Department of Biology, University of Maryland - College Park, College Park, Maryland, United States of America
| | - William F. Fagan
- Department of Biology, University of Maryland - College Park, College Park, Maryland, United States of America
| | - Philip L. F. Johnson
- Department of Biology, University of Maryland - College Park, College Park, Maryland, United States of America
- * E-mail:
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Xu M, Wan J, Niu Q, Liu R. PFOA and PFOS interact with superoxide dismutase and induce cytotoxicity in mouse primary hepatocytes: A combined cellular and molecular methods. ENVIRONMENTAL RESEARCH 2019; 175:63-70. [PMID: 31103794 DOI: 10.1016/j.envres.2019.05.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/10/2019] [Accepted: 05/08/2019] [Indexed: 05/08/2023]
Abstract
This study investigated the adverse effects of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) on mouse primary hepatocytes by conducting cell viability, apoptosis, intracellular oxidative stress level, superoxide dismutase (SOD), catalase (CAT) activity and glutathione level assays. It was shown that PFOA and PFOS altered antioxidant enzymes activities and triggered oxidative stress, and thus exhibited cytotoxicity to the hepatocytes. Molecular mechanisms of SOD activities were measured and structural changes were explored by isothermal titration calorimetry and multiple spectroscopy. PFOA and PFOS bind to SOD via electrostatic forces with 7.634 ± 0.06 and 9.7 ± 0.4 sites, respectively, leading to structural and conformational changes. The overall results demonstrated that PFOS and PFOA are able to interact with SOD directly, resulting in producing oxidative stress and induce apoptosis.
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Affiliation(s)
- Mengchen Xu
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China
| | - Jingqiang Wan
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China
| | - Qigui Niu
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China
| | - Rutao Liu
- School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 72# Jimo Binhai Road, Qingdao, Shandong, 266237, PR China.
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49
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Huang H, Liao J, Zheng X, Chen Y, Ren H. Low-level free nitrous acid efficiently inhibits the conjugative transfer of antibiotic resistance by altering intracellular ions and disabling transfer apparatus. WATER RESEARCH 2019; 158:383-391. [PMID: 31059932 DOI: 10.1016/j.watres.2019.04.046] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 06/09/2023]
Abstract
Recently, the dissemination of antibiotic resistance genes (ARGs) via plasmid-mediated conjugation has been reported to be facilitated by a series of contaminants. This has highlighted potential challenges to the effective control of this principal mode of horizontal transfer. In the present study, we found that low levels (<0.02 mgN/L) of free nitrous acid (FNA) remarkably inhibited (over 90%) the conjugative transfer of plasmid RP4, a model broad-host-range plasmid, between Escherichia coli. The antimicrobial role of FNA at the applied dosages was firstly ruled out, since no dramatic reductions in viabilities of donor or recipient were observed. Instead, FNA appeared to reduce the available intracellular free Mg2+, which was confirmed to be triggered by the liberation of intracellular Fe2+. These alterations in intracellular Mg2+ and Fe2+ concentrations were found to significantly limit the available energy for conjugative transfer through suppression of glycolysis by decreasing the activities of glycogen phosphorylase and glyceraldehyde-3-phosphate dehydrogenase and also by diverting the glycolytic flux into the pentose phosphate pathway via activation of glucose-6-phosphate dehydrogenase towards the generation of NADPH rather than ATP. Moreover, RP4-encoding genes responsible for DNA transfer and replication (traI, traJ and trfAp), coupling (traG) and mating pair formation (traF and trbBp) were all significantly down-regulated after FNA treatment, indicating that the transfer apparatus required for plasmid processing and delivery was deactivated. By validating the inhibitory effects of FNA on conjugation in real wastewater, this study highlights a promising method for controlling the dissemination of ARGs in systems such as wastewater treatment plants.
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Affiliation(s)
- Haining Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Junqi Liao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiong Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093, Jiangsu, PR China
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Weissman JL, Laljani RMR, Fagan WF, Johnson PLF. Visualization and prediction of CRISPR incidence in microbial trait-space to identify drivers of antiviral immune strategy. ISME JOURNAL 2019; 13:2589-2602. [PMID: 31239539 PMCID: PMC6776019 DOI: 10.1038/s41396-019-0411-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 03/15/2019] [Accepted: 03/24/2019] [Indexed: 01/21/2023]
Abstract
Bacteria and archaea are locked in a near-constant battle with their viral pathogens. Despite previous mechanistic characterization of numerous prokaryotic defense strategies, the underlying ecological drivers of different strategies remain largely unknown and predicting which species will take which strategies remains a challenge. Here, we focus on the CRISPR immune strategy and develop a phylogenetically-corrected machine learning approach to build a predictive model of CRISPR incidence using data on over 100 traits across over 2600 species. We discover a strong but hitherto-unknown negative interaction between CRISPR and aerobicity, which we hypothesize may result from interference between CRISPR-associated proteins and non-homologous end-joining DNA repair due to oxidative stress. Our predictive model also quantitatively confirms previous observations of an association between CRISPR and temperature. Finally, we contrast the environmental associations of different CRISPR system types (I, II, III) and restriction modification systems, all of which act as intracellular immune systems.
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Affiliation(s)
- Jake L Weissman
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Rohan M R Laljani
- Department of Biology, University of Maryland, College Park, MD, USA
| | - William F Fagan
- Department of Biology, University of Maryland, College Park, MD, USA
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