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Pi H, Carlin SM, Beavers WN, Hillebrand GH, Krystofiak ES, Stauff DL, Skaar EP. FapR regulates HssRS-mediated heme homeostasis in Bacillus anthracis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602573. [PMID: 39026866 PMCID: PMC11257595 DOI: 10.1101/2024.07.08.602573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Bacillus anthracis, a Gram-positive facultative anaerobe and the causative agent of anthrax, multiplies to extraordinarily high numbers in vertebrate blood, resulting in considerable heme exposure. Heme is an essential nutrient and the preferred iron source for bacteria during vertebrate colonization, but its high redox potential makes it toxic in excess. To regulate heme homeostasis, many Gram-positive bacteria, including B. anthracis, rely on the two-component signaling system HssRS. HssRS comprises the heme sensing histidine kinase HssS, which modulates the activity of the HssR transcription factor to enable bacteria to circumvent heme toxicity. However, the regulation of the HssRS system remains unclear. Here we identify FapR, the transcriptional regulator of fatty acid biosynthesis, as a key factor in HssRS function. FapR plays an important role in maintaining membrane integrity and the localization of the histidine kinase HssS. Specifically, disruption of fapR leads to increased membrane rigidity, which hinders the penetration of HssRS inducers, resulting in the inactivation of HssRS. Furthermore, deletion of fapR affects the loading of HssS onto the cell membrane, compromising its heme sensing function and subsequently reducing endogenous heme biosynthesis. These findings shed light on the molecular mechanisms governing bacterial adaptation to heme stress and provide potential targets for antimicrobial intervention strategies.
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Affiliation(s)
- Hualiang Pi
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN
- Current address: Department of Microbial Pathogenesis and Microbial Sciences Institute, Yale University School of Medicine, New Haven, CT
| | - Sophia M. Carlin
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - William N. Beavers
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN
| | | | - Evan S. Krystofiak
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | | | - Eric P. Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, TN
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2
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Chen H, Wang Y, Wang W, Cao T, Zhang L, Wang Z, Chi X, Shi T, Wang H, He X, Liang M, Yang M, Jiang W, Lv D, Yu J, Zhu G, Xie Y, Gao B, Wang X, Liu X, Li Y, Ouyang L, Zhang J, Liu H, Li Z, Tong Y, Xia X, Tan GY, Zhang L. High-yield porphyrin production through metabolic engineering and biocatalysis. Nat Biotechnol 2024:10.1038/s41587-024-02267-3. [PMID: 38839873 DOI: 10.1038/s41587-024-02267-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 04/26/2024] [Indexed: 06/07/2024]
Abstract
Porphyrins and their derivatives find extensive applications in medicine, food, energy and materials. In this study, we produced porphyrin compounds by combining Rhodobacter sphaeroides as an efficient cell factory with enzymatic catalysis. Genome-wide CRISPRi-based screening in R. sphaeroides identifies hemN as a target for improved coproporphyrin III (CPIII) production, and exploiting phosphorylation of PrrA further improves the production of bioactive CPIII to 16.5 g L-1 by fed-batch fermentation. Subsequent screening and engineering high-activity metal chelatases and coproheme decarboxylase results in the synthesis of various metalloporphyrins, including heme and the anti-tumor agent zincphyrin. After pilot-scale fermentation (200 L) and setting up the purification process for CPIII (purity >95%), we scaled up the production of heme and zincphyrin through enzymatic catalysis in a 5-L bioreactor, with CPIII achieving respective enzyme conversion rates of 63% and 98% and yielding 10.8 g L-1 and 21.3 g L-1, respectively. Our strategy offers a solution for high-yield bioproduction of heme and other valuable porphyrins with substantial industrial and medical applications.
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Affiliation(s)
- Haihong Chen
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Yaohong Wang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Weishan Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ting Cao
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Zhengduo Wang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xuran Chi
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Tong Shi
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Huangwei Wang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xinwei He
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Mindong Liang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Mengxue Yang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Wenyi Jiang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Dongyuan Lv
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Jiaming Yu
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Guoliang Zhu
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Yongtao Xie
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Bei Gao
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xinye Wang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Xueting Liu
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Youyuan Li
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Liming Ouyang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Jingyu Zhang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Huimin Liu
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Zilong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yaojun Tong
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xuekui Xia
- Key Biosensor Laboratory of Shandong Province, Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Gao-Yi Tan
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China.
| | - Lixin Zhang
- State Key Laboratory of Bioreactor Engineering and School of Biotechnology, East China University of Science and Technology, Shanghai, China.
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3
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Falb N, Patil G, Furtmüller PG, Gabler T, Hofbauer S. Structural aspects of enzymes involved in prokaryotic Gram-positive heme biosynthesis. Comput Struct Biotechnol J 2023; 21:3933-3945. [PMID: 37593721 PMCID: PMC10427985 DOI: 10.1016/j.csbj.2023.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/19/2023] [Accepted: 07/19/2023] [Indexed: 08/19/2023] Open
Abstract
The coproporphyrin dependent heme biosynthesis pathway is almost exclusively utilized by Gram-positive bacteria. This fact makes it a worthwhile topic for basic research, since a fundamental understanding of a metabolic pathway is necessary to translate the focus towards medical biotechnology, which is very relevant in this specific case, considering the need for new antibiotic targets to counteract the pathogenicity of Gram-positive superbugs. Over the years a lot of structural data on the set of enzymes acting in Gram-positive heme biosynthesis has accumulated in the Protein Database (www.pdb.org). One major challenge is to filter and analyze all available structural information in sufficient detail in order to be helpful and to draw conclusions. Here we pursued to give a holistic overview of structural information on enzymes involved in the coproporphyrin dependent heme biosynthesis pathway. There are many aspects to be extracted from experimentally determined structures regarding the reaction mechanisms, where the smallest variation of the position of an amino acid residue might be important, but also on a larger level regarding protein-protein interactions, where the focus has to be on surface characteristics and subunit (secondary) structural elements and oligomerization. This review delivers a status quo, highlights still missing information, and formulates future research endeavors in order to better understand prokaryotic heme biosynthesis.
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Affiliation(s)
- Nikolaus Falb
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Gaurav Patil
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Paul G. Furtmüller
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Thomas Gabler
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
| | - Stefan Hofbauer
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, A-1190 Vienna, Austria
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4
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Lu M, Wong KI, Li X, Wang F, Wei L, Wang S, Wu MX. Oregano Oil and Harmless Blue Light to Synergistically Inactivate Multidrug-Resistant Pseudomonas aeruginosa. Front Microbiol 2022; 13:810746. [PMID: 35359746 PMCID: PMC8961286 DOI: 10.3389/fmicb.2022.810746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 01/25/2022] [Indexed: 11/20/2022] Open
Abstract
Blue light (BL) at 405 nm and oregano essential oil (OEO) have shown bactericidal activity by its own. Here, we demonstrated that the two synergistically killed multidrug-resistant (MDR) Pseudomonas aeruginosa (Pa). Pa ATCC19660 and HS0065 planktonic cells and mature biofilms were reduced by more than 7 log10 after treatment by BL combined with OEO, in sharp contrast to no significant bacterial reduction with the monotreatment. The duo also sufficiently eliminated acute or biofilm-associated infection of open burn wounds in murine without incurring any harmful events in the skin. The synergic bactericide was attributed mainly to the ability of OEO to magnify cytotoxic reactive oxygen species (ROS) production initiated by BL that excited endogenous tetrapyrrole macrocycles in bacteria while completely sparing the surrounding tissues from the phototoxic action. OEO ingredient analysis in combination with microbial assays identified carvacrol and its isomer thymol to be the major phytochemicals that cooperated with BL executing synergic killing. The finding argues persuasively for valuable references of carvacrol and thymol in assessing and standardizing the bactericidal potential of various OEO products.
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Affiliation(s)
- Min Lu
- Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Department of Orthopaedics, Ruijin Hospital, Shanghai Institute of Traumatology and Orthopaedics, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ka Ioi Wong
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xin Li
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Wang
- Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Department of Orthopaedics, Ruijin Hospital, Shanghai Institute of Traumatology and Orthopaedics, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Wei
- Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Department of Orthopaedics, Ruijin Hospital, Shanghai Institute of Traumatology and Orthopaedics, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shen Wang
- Department of Plastic and Reconstructive Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mei X. Wu
- Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States
- *Correspondence: Mei X. Wu,
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5
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DnaJ and ClpX are required for HitRS and HssRS two-component system signaling in Bacillus anthracis. Infect Immun 2021; 90:e0056021. [PMID: 34748369 DOI: 10.1128/iai.00560-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacillus anthracis is the causative agent of anthrax. This Gram-positive bacterium poses a substantial risk to human health due to high mortality rates and the potential for malicious use as a bioterror weapon. To survive within the vertebrate host, B. anthracis relies on two-component system (TCS) signaling to sense host-induced stresses and respond to alterations in the environment through changes in target gene expression. HitRS and HssRS are cross-regulating TCSs in B. anthracis that respond to cell envelope disruptions and high heme levels, respectively. In this study, an unbiased and targeted genetic selection was designed to identify gene products that are involved in HitRS and HssRS signaling. This selection led to the identification of inactivating mutations within dnaJ and clpX that disrupt HitRS- and HssRS-dependent gene expression. DnaJ and ClpX are the substrate-binding subunits of the DnaJK protein chaperone and ClpXP protease, respectively. DnaJ regulates the levels of HitR and HitS to facilitate signal transduction, while ClpX specifically regulates HitS levels. Together these results reveal that the protein homeostasis regulators, DnaJ and ClpX, function to maintain B. anthracis signal transduction activities through TCS regulation. One sentence summary: Use of a genetic selection strategy to identify modulators of two-component system signaling in Bacillus anthracis.
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6
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Simultaneous exposure to intracellular and extracellular photosensitizers for the treatment of Staphylococcus aureus infections. Antimicrob Agents Chemother 2021; 65:e0091921. [PMID: 34516248 DOI: 10.1128/aac.00919-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a serious threat to public health due to the rise of antibiotic resistance in this organism, which can prolong or exacerbate skin and soft tissue infections (SSTIs). Methicillin-resistant S. aureus is a Gram-positive bacterium and a leading cause of SSTIs. As such, many efforts are underway to develop therapies that target essential biological processes in S. aureus. Antimicrobial photodynamic therapy is effective alternative to antibiotics, therefore we developed an approach to simultaneously expose S. aureus to intracellular and extracellular photoactivators. A near infrared photosensitizer was conjugated to human monoclonal antibodies (mAbs) that target the S. aureus Isd heme acquisition proteins. Additionally, the compound VU0038882 was developed to increase photoactivatable porphyrins within the cell. Combinatorial PDT treatment of drug-resistant S. aureus exposed to VU0038882 and conjugated anti-Isd mAbs proved to be an effective antibacterial strategy in vitro and in a murine model of SSTIs.
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7
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Lu M, Wang S, Wang T, Hu S, Bhayana B, Ishii M, Kong Y, Cai Y, Dai T, Cui W, Wu MX. Bacteria-specific phototoxic reactions triggered by blue light and phytochemical carvacrol. Sci Transl Med 2021; 13:13/575/eaba3571. [PMID: 33408183 DOI: 10.1126/scitranslmed.aba3571] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 06/26/2020] [Accepted: 11/16/2020] [Indexed: 12/15/2022]
Abstract
Development of alternatives to antibiotics is one of the top priorities in the battle against multidrug-resistant (MDR) bacterial infections. Here, we report that two naturally occurring nonantibiotic modalities, blue light and phytochemical carvacrol, synergistically kill an array of bacteria including their planktonic forms, mature biofilms, and persisters, irrespective of their antibiotic susceptibility. Combination but not single treatment completely or substantially cured acute and established biofilm-associated Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus infections of full thickness murine third-degree burn wounds and rescued mice from lethal Pseudomonas aeruginosa skin wound infections. The combined therapy diminished bacterial colony-forming units as high as 7.5 log10 within 30 min and introduced few adverse events in the survival of cocultured mammalian cells, wound healing, or host DNA. Mechanistic studies revealed that carvacrol was photocatalytically oxidized into a series of photoreactive substrates that underwent photolysis or additional photosensitization reactions in response to the same blue light, forming two autoxidation cycles that interacted with each other resulting in robust generation of cytotoxic reactive oxygen species. This phototoxic reaction took place exclusively in bacteria, initiated by blue light excitation of endogenous porphyrin-like molecules abundantly produced in bacteria compared with mammalian cells. Moreover, no bacterial resistance developed to the combined treatment after 20 successive passages. This highly selective phototoxic reaction confers a unique strategy to combat the growing threat of MDR bacteria.
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Affiliation(s)
- Min Lu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA.,Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China
| | - Shen Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Tao Wang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China
| | - Sisi Hu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Brijesh Bhayana
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Momoko Ishii
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Yifei Kong
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Yuchen Cai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Wenguo Cui
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P. R. China.
| | - Mei X Wu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA.
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8
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Photoinactivation of mycobacteria to combat infection diseases: current state and perspectives. Appl Microbiol Biotechnol 2021; 105:4099-4109. [PMID: 33997929 PMCID: PMC8126513 DOI: 10.1007/s00253-021-11349-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/04/2021] [Accepted: 05/09/2021] [Indexed: 12/11/2022]
Abstract
Abstract The spread of multi-drug-resistant bacterial strains causing serious infectious diseases dictates the development of new approaches to combat these diseases. In addition to drug resistance, the important causative agent of tuberculosis (Mycobacterium tuberculosis (Mtb)) is able to persist asymptomatically in individuals for many years, causing latent forms of tuberculosis. In such a dormant state, Mtb cells are also resistant to known antibiotics. In this regard, photodynamic inactivation (PDI) could be an effective alternative to antibiotics as its action is based on the generation of active forms of oxygen independently on the presence of specific antibiotic targets, thereby inactivating both drug-resistant and dormant bacteria. In this review, we summarise examples of the application of PDI for the elimination of representatives of the genus Mycobacteria, both in vitro and in vivo. According to published results, including photosensitisers in the PDI regime results in a significantly higher lethal effect. Such experiments were mainly performed using chemically synthesised photosensitisers, which need to be transported to the areas of bacterial infections, limiting PDI usage by surface (skin) diseases. In this regard, endogenous photosensitisers (mainly porphyrins) could be used to solve the problem of transportation. In vitro experiments demonstrate the effective application of PDI for mycobacteria, including Mtb, using endogenous porphyrins; the intracellular contents of these substances can be elevated by administration of 5-aminolevulenic acid, a precursor of porphyrin synthesis. Photodynamic inactivation can also be used for dormant mycobacteria, which are characterised by high levels of endogenous porphyrins. Thus, PDI can effectively eliminate drug-resistant mycobacteria. The exploitation of modern light-transmitting techniques opens new possibilities to use PDI in clinical settings. Key points •The potential effects of photodynamic inactivation of mycobacteria are critically reviewed. •Approaches to photoinactivation of mycobacteria using exogenous and endogenous photosensitisers are described. •Prospects for the use of photodynamic inactivation in the treatment of tuberculosis are discussed.
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Pérez C, Zúñiga T, Palavecino CE. Photodynamic therapy for treatment of Staphylococcus aureus infections. Photodiagnosis Photodyn Ther 2021; 34:102285. [PMID: 33836278 DOI: 10.1016/j.pdpdt.2021.102285] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/10/2021] [Accepted: 04/02/2021] [Indexed: 12/09/2022]
Abstract
BACKGROUND Staphylococcus aureus is a Gram-positive spherical bacterium that commonly causes various infections which can range from superficial to life-threatening. Hospital strains of S. aureus are often resistant to antibiotics, which has made their treatment difficult in recent decades. Other therapeutic alternatives have been postulated to overcome the drawbacks of antibiotic multi-resistance. Of these, photodynamic therapy (PDT) is a promising approach to address the notable shortage of new active antibiotics against multidrug-resistant S. aureus. PDT combines the use of a photosensitizer agent, light, and oxygen to eradicate pathogenic microorganisms. Through a systematic analysis of published results, this work aims to verify the usefulness of applying PDT in treating multidrug-resistant S.aureus infections. METHODS This review was based on a bibliographic search in various databases and the analysis of relevant publications. RESULTS There is currently a large body of evidence demonstrating the efficacy of photodynamic therapy in eliminating S.aureus strains. Both biofilm-producing strains, as well as multidrug-resistant strains. CONCLUSION We conclude that there is sufficient scientific evidence that PDT is a useful adjunct to traditional antibiotic therapy for treating S. aureus infections. Clinical application through appropriate trials should be introduced to further define optimal treatment protocols, safety and efficay.
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Affiliation(s)
- Camila Pérez
- Escuela de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad Central de Chile, Chile.
| | - Tania Zúñiga
- Escuela de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad Central de Chile, Chile.
| | - Christian Erick Palavecino
- Laboratorio de Microbiología Celular, Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Lord Cochrane 418, 8330546, Santiago, Chile.
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10
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Klimka A, Mertins S, Nicolai AK, Rummler LM, Higgins PG, Günther SD, Tosetti B, Krut O, Krönke M. Epitope-specific immunity against Staphylococcus aureus coproporphyrinogen III oxidase. NPJ Vaccines 2021; 6:11. [PMID: 33462229 PMCID: PMC7813823 DOI: 10.1038/s41541-020-00268-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/27/2020] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus represents a serious infectious threat to global public health and a vaccine against S. aureus represents an unmet medical need. We here characterise two S. aureus vaccine candidates, coproporphyrinogen III oxidase (CgoX) and triose phosphate isomerase (TPI), which fulfil essential housekeeping functions in heme synthesis and glycolysis, respectively. Immunisation with rCgoX and rTPI elicited protective immunity against S. aureus bacteremia. Two monoclonal antibodies (mAb), CgoX-D3 and TPI-H8, raised against CgoX and TPI, efficiently provided protection against S. aureus infection. MAb-CgoX-D3 recognised a linear epitope spanning 12 amino acids (aa), whereas TPI-H8 recognised a larger discontinuous epitope. The CgoX-D3 epitope conjugated to BSA elicited a strong, protective immune response against S. aureus infection. The CgoX-D3 epitope is highly conserved in clinical S. aureus isolates, indicating its potential wide usability against S. aureus infection. These data suggest that immunofocusing through epitope-based immunisation constitutes a strategy for the development of a S. aureus vaccine with greater efficacy and better safety profile.
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Affiliation(s)
- Alexander Klimka
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany
| | - Sonja Mertins
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany
| | - Anne Kristin Nicolai
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany
| | - Liza Marie Rummler
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany
| | - Paul G Higgins
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany
| | - Saskia Diana Günther
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany.,Cologne Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Bettina Tosetti
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany.,Cologne Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Oleg Krut
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,Paul-Ehrlich Institute, Langen, Germany
| | - Martin Krönke
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany. .,German Center for Infection Research (DZIF), Partner site Bonn-Cologne, Cologne, Germany. .,Cologne Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany. .,Center for Molecular Medicine Cologne (CMMC), Cologne, Germany.
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11
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Chan EWL, Chin MY, Low YH, Tan HY, Ooi YS, Chong CW. The Antibacterial Agent Identified from Acidocella spp. in the Fluid of Nepenthes gracilis Against Multidrug-Resistant Klebsiella pneumoniae: A Functional Metagenomic Approach. Microb Drug Resist 2020; 27:1018-1028. [PMID: 33325795 DOI: 10.1089/mdr.2020.0311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aims: The fluid of Nepenthes gracilis harbors diverse bacterial taxa that could serve as a gene pool for the discovery of the new genre of antimicrobial agents against multidrug-resistant Klebsiella pneumoniae. The aim of this study was to explore the presence of antibacterial genes in the fluids of N. gracilis growing in the wild. Methods: Using functional metagenomic approach, fosmid clones were isolated and screened for antibacterial activity against three strains of K. pneumoniae. A clone that exhibited the most potent antibacterial activity was sent for sequencing to identify the genes responsible for the observed activity. The secondary metabolites secreted by the selected clone was sequentially extracted using hexane, chloroform, and ethyl acetate. The chemical profiles of a clone (C6) hexane extract were determined by gas chromatography/mass spectrometry (GC-MS). Results: Fosmid clone C6 from the fluid of pitcher plant that exhibited antibacterial activity against three strains of K. pneumoniae was isolated using functional metagenome approach. A majority of the open reading frames detected from C6 were affiliated with the largely understudied Acidocella genus. Among them, the gene that encodes for coproporphyrinogen III oxidase in the heme biosynthesis pathway could be involved in the observed antibacterial activity. Based on the GC-MS analysis, the identities of the putative bioactive compounds were 2,5-di-tert-butylphenol and 1-ethyl-2-methyl cyclododecane. Conclusions: The gene that encodes for coproporphyrinogen III oxidase in the heme biosynthesis pathway as well as the secondary metabolites, namely 2,5-di-tert-butylphenol and 1-ethyl-2-methyl cyclododecane could be the potential antibacterial molecules responsible for the antibacterial activity of C6.
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Affiliation(s)
- Elaine Wan Ling Chan
- Institute for Research, Development and Innovation, International Medical University, Kuala Lumpur, Malaysia
| | - Mei Yu Chin
- School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Yi Hui Low
- School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Hui Yin Tan
- School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Yi Sing Ooi
- School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Chun Wie Chong
- Institute for Research, Development and Innovation, International Medical University, Kuala Lumpur, Malaysia.,School of Pharmacy, Monash University Malaysia, Bandar Sunway, Malaysia
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12
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Chaudhary D, Pramanik T, Santra S. Thiocoumarins and Dithiocoumarins: Advances in Synthesis and Pharmacological Activity. CURR ORG CHEM 2020. [DOI: 10.2174/1385272824999200812132707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Thiocoumarins and dithiocoumarins are two important classes of sulphurcontaining
heterocyclic compounds, which are bioisosteres of coumarins. Herein, various
synthetic strategies for these two classes of heterocyclic compounds reported in the literature
have been discussed. Different solvents, catalysts, reagents and reaction conditions,
which were employed successfully for synthesizing thiocoumarins and dithiocoumarins
have also been described concisely in this review. Mechanistic overview has been given
wherever it was necessary. In addition, a comparative view of various solvents, catalysts
and reagents focusing on their efficiency for synthesizing thiocoumarins and dithiocoumarins,
has been discussed as well. Furthermore, pharmacological activities of these two
classes of compounds have also been discussed.
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Affiliation(s)
- Diksha Chaudhary
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab 144411, India
| | - Tanay Pramanik
- Department of Chemistry, University of Engineering and Management, University Area, Action Area III, B/5, Newtown, Kolkata, West Bengal - 700160, India
| | - Soumava Santra
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab 144411, India
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13
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Walter AB, Simpson J, Jenkins JL, Skaar EP, Jansen ED. Optimization of optical parameters for improved photodynamic therapy of Staphylococcus aureus using endogenous coproporphyrin III. Photodiagnosis Photodyn Ther 2019; 29:101624. [PMID: 31866531 DOI: 10.1016/j.pdpdt.2019.101624] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/28/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND It has recently been shown that endogenous photosensitization of Gram-positive bacteria is achieved through the accumulation of the heme precursor coproporphyrin III and not protoporphyrin IX, as was previously assumed. As previous studies have operated under this assumption, the efficacy of optimal targeting of the absorption peaks of coproporphyrin III has not been explored. METHODS Staphylococcus aureus was endogenously photosensitized through the addition of either the small molecule VU0038882, aminolevulinic acid, or both. The efficacy of five different LEDs whose wavelengths target different coproporphyrin III absorption peaks were determined in vitro. Based on these in vitro measurements, the effectiveness of utilizing these LEDs to treat a skin infection was predicted using a Monte Carlo simulation to estimate the fluence rates and resulting bacterial reductions as a function of depth. RESULTS Optimal targeting of the Soret band provided a 4.7-log improvement as compared to previously utilized wavelengths. Activation of the Q-bands was found to provide similar cytotoxic effects but required significantly larger doses of light. Despite near sterilization in vitro, it was predicted that Soret band targeted light would only provide at least a 2 log-reduction up to 430 μm into the skin while Q-band targeted light could remain effective up to 1 mm in depth. Multiplexing these different wavelengths was found to provide a further 0.5-1.0 log-reduction in bacterial viability. CONCLUSIONS Accurate targeting of coproporphyrin III has shown that endogenous photodynamic therapy has the potential to be further developed into an effective treatment of skin and soft tissue infections caused by Gram-positive bacteria.
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Affiliation(s)
- Alec B Walter
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Biophotonics Center, Vanderbilt University, Nashville, TN, USA
| | - Jocelyn Simpson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - J Logan Jenkins
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Biophotonics Center, Vanderbilt University, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Biophotonics Center, Vanderbilt University, Nashville, TN, USA.
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14
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Luo Y, Li J, Liu X, Tan L, Cui Z, Feng X, Yang X, Liang Y, Li Z, Zhu S, Zheng Y, Yeung KWK, Yang C, Wang X, Wu S. Dual Metal-Organic Framework Heterointerface. ACS CENTRAL SCIENCE 2019; 5:1591-1601. [PMID: 31572786 PMCID: PMC6764158 DOI: 10.1021/acscentsci.9b00639] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Indexed: 05/19/2023]
Abstract
Herein, a core-shell dual metal-organic framework (MOF) heterointerface is synthesized. The Prussian blue (PB) MOF acts as a core for the growth of a porphyrin-doped MOF which is named PB@MOF. Porphyrins can significantly enhance the transfer of photoinspired electrons from PB and suppress the recombination of electrons and holes, thus enhancing the photocatalytic properties and consequently promoting the yields of singlet oxygen rapidly under 660 nm illumination. PB@MOF can exhibit a better photothermal conversion efficiency up to 29.9% under 808 nm near-infrared irradiation (NIR). The PB@MOF heterointerface can possess excellent antibacterial efficacies of 99.31% and 98.68% opposed to Staphylococcus aureus and Escherichia coli, separately, under the dual light illumination of 808 nm NIR and 660 nm red light for 10 min. Furthermore, the trace amount of Fe and Zr ions can trigger the immune system to favor wound healing, promising that PB@MOF achieves the rapid therapy of bacterial infected wounds and environmental disinfection.
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Affiliation(s)
- Yue Luo
- Ministry-of-Education Key Laboratory for the Green
Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer
Materials, School of Materials Science & Engineering, Hubei
University, Wuhan 430062, China
| | - Jun Li
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Xiangmei Liu
- Ministry-of-Education Key Laboratory for the Green
Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer
Materials, School of Materials Science & Engineering, Hubei
University, Wuhan 430062, China
- E-mail:
| | - Lei Tan
- Ministry-of-Education Key Laboratory for the Green
Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer
Materials, School of Materials Science & Engineering, Hubei
University, Wuhan 430062, China
| | - Zhenduo Cui
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Xiaobo Feng
- Department of Orthopaedics, Union Hospital,
Tongji Medical College, Huazhong University of Science and
Technology, Wuhan 430022, China
| | - Xianjin Yang
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Yanqin Liang
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Zhaoyang Li
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Shengli Zhu
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
| | - Yufeng Zheng
- State Key Laboratory for Turbulence and Complex System
and Department of Materials Science and Engineering, College of Engineering,
Peking University, Beijing 100871,
China
| | - Kelvin Wai Kwok Yeung
- Department of Orthopaedics & Traumatology, Li Ka
Shing Faculty of Medicine, The University of Hong Kong,
Pokfulam, Hong Kong 999077, China
| | - Cao Yang
- Department of Orthopaedics, Union Hospital,
Tongji Medical College, Huazhong University of Science and
Technology, Wuhan 430022, China
| | - Xianbao Wang
- Ministry-of-Education Key Laboratory for the Green
Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer
Materials, School of Materials Science & Engineering, Hubei
University, Wuhan 430062, China
| | - Shuilin Wu
- Ministry-of-Education Key Laboratory for the Green
Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer
Materials, School of Materials Science & Engineering, Hubei
University, Wuhan 430062, China
- School of Materials Science & Engineering, the Key
Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of
China, Tianjin University, Tianjin 300072,
China
- E-mail: ;
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15
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Abstract
Staphylococcus aureus is one of the most important human pathogens that is responsible for a variety of diseases ranging from skin and soft tissue infections to endocarditis and sepsis. In recent decades, the treatment of staphylococcal infections has become increasingly difficult as the prevalence of multi-drug resistant strains continues to rise. With increasing mortality rates and medical costs associated with drug resistant strains, there is an urgent need for alternative therapeutic options. Many innovative strategies for alternative drug development are being pursued, including disruption of biofilms, inhibition of virulence factor production, bacteriophage-derived antimicrobials, anti-staphylococcal vaccines, and light-based therapies. While many compounds and methods still need further study to determine their feasibility, some are quickly approaching clinical application and may be available in the near future.
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16
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Thomsen IP, Liu GY. Targeting fundamental pathways to disrupt Staphylococcus aureus survival: clinical implications of recent discoveries. JCI Insight 2018. [PMID: 29515041 DOI: 10.1172/jci.insight.98216] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The emergence of community-associated methicillin-resistant Staphylococcus aureus during the past decade along with an impending shortage of effective antistaphylococcal antibiotics have fueled impressive advances in our understanding of how S. aureus overcomes the host environment to establish infection. Backed by recent technologic advances, studies have uncovered elaborate metabolic, nutritional, and virulence strategies deployed by S. aureus to survive the restrictive and hostile environment imposed by the host, leading to a plethora of promising antimicrobial approaches that have potential to remedy the antibiotic resistance crisis. In this Review, we highlight some of the critical and recently elucidated bacterial strategies that are potentially amenable to intervention, discuss their relevance to human diseases, and address the translational challenges posed by current animal models.
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Affiliation(s)
- Isaac P Thomsen
- Department of Pediatrics, Division of Pediatric Infectious Diseases, and Vanderbilt Vaccine Research Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - George Y Liu
- Division of Pediatric Infectious Diseases and Research Division of Immunology, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, California, USA
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17
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McClary JS, Boehm AB. Transcriptional Response of Staphylococcus aureus to Sunlight in Oxic and Anoxic Conditions. Front Microbiol 2018; 9:249. [PMID: 29599752 PMCID: PMC5863498 DOI: 10.3389/fmicb.2018.00249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/31/2018] [Indexed: 12/20/2022] Open
Abstract
The transcriptional response of Staphylococcus aureus strain Newman to sunlight exposure was investigated under both oxic and anoxic conditions using RNA sequencing to gain insight into potential mechanisms of inactivation. S. aureus is a pathogenic bacterium detected at recreational beaches which can cause gastrointestinal illness and skin infections, and is of increasing public health concern. To investigate the S. aureus photostress response in oligotrophic seawater, S. aureus cultures were suspended in seawater and exposed to full spectrum simulated sunlight. Experiments were performed under oxic or anoxic conditions to gain insight into the effects of oxygen-mediated and non-oxygen-mediated inactivation mechanisms. Transcript abundance was measured after 6 h of sunlight exposure using RNA sequencing and was compared to transcript abundance in paired dark control experiments. Culturable S. aureus decayed following biphasic inactivation kinetics with initial decay rate constants of 0.1 and 0.03 m2 kJ−1 in oxic and anoxic conditions, respectively. RNA sequencing revealed that 71 genes had different transcript abundance in the oxic sunlit experiments compared to dark controls, and 18 genes had different transcript abundance in the anoxic sunlit experiments compared to dark controls. The majority of genes showed reduced transcript abundance in the sunlit experiments under both conditions. Three genes (ebpS, NWMN_0867, and NWMN_1608) were found to have the same transcriptional response to sunlight between both oxic and anoxic conditions. In the oxic condition, transcripts associated with porphyrin metabolism, nitrate metabolism, and membrane transport functions were increased in abundance during sunlight exposure. Results suggest that S. aureus responds differently to oxygen-dependent and oxygen-independent photostress, and that endogenous photosensitizers play an important role during oxygen-dependent indirect photoinactivation.
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Affiliation(s)
- Jill S McClary
- Civil and Environmental Engineering, Stanford University, Stanford, CA, United States
| | - Alexandria B Boehm
- Civil and Environmental Engineering, Stanford University, Stanford, CA, United States
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18
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Choby JE, Grunenwald CM, Celis AI, Gerdes SY, DuBois JL, Skaar EP. Staphylococcus aureus HemX Modulates Glutamyl-tRNA Reductase Abundance To Regulate Heme Biosynthesis. mBio 2018; 9:e02287-17. [PMID: 29437922 PMCID: PMC5801465 DOI: 10.1128/mbio.02287-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/08/2018] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus is responsible for a significant amount of devastating disease. Its ability to colonize the host and cause infection is supported by a variety of proteins that are dependent on the cofactor heme. Heme is a porphyrin used broadly across kingdoms and is synthesized de novo from common cellular precursors and iron. While heme is critical to bacterial physiology, it is also toxic in high concentrations, requiring that organisms encode regulatory processes to control heme homeostasis. In this work, we describe a posttranscriptional regulatory strategy in S. aureus heme biosynthesis. The first committed enzyme in the S. aureus heme biosynthetic pathway, glutamyl-tRNA reductase (GtrR), is regulated by heme abundance and the integral membrane protein HemX. GtrR abundance increases dramatically in response to heme deficiency, suggesting a mechanism by which S. aureus responds to the need to increase heme synthesis. Additionally, HemX is required to maintain low levels of GtrR in heme-proficient cells, and inactivation of hemX leads to increased heme synthesis. Excess heme synthesis in a ΔhemX mutant activates the staphylococcal heme stress response, suggesting that regulation of heme synthesis is critical to reduce self-imposed heme toxicity. Analysis of diverse organisms indicates that HemX is widely conserved among heme-synthesizing bacteria, suggesting that HemX is a common factor involved in the regulation of GtrR abundance. Together, this work demonstrates that S. aureus regulates heme synthesis by modulating GtrR abundance in response to heme deficiency and through the activity of the broadly conserved HemX.IMPORTANCEStaphylococcus aureus is a leading cause of skin and soft tissue infections, endocarditis, bacteremia, and osteomyelitis, making it a critical health care concern. Development of new antimicrobials against S. aureus requires knowledge of the physiology that supports this organism's pathogenesis. One component of staphylococcal physiology that contributes to growth and virulence is heme. Heme is a widely utilized cofactor that enables diverse chemical reactions across many enzyme families. S. aureus relies on many critical heme-dependent proteins and is sensitive to excess heme toxicity, suggesting S. aureus must maintain proper intracellular heme homeostasis. Because S. aureus provides heme for heme-dependent enzymes via synthesis from common precursors, we hypothesized that regulation of heme synthesis is one mechanism to maintain heme homeostasis. In this study, we identify that S. aureus posttranscriptionally regulates heme synthesis by restraining abundance of the first heme biosynthetic enzyme, GtrR, via heme and the broadly conserved membrane protein HemX.
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Affiliation(s)
- Jacob E Choby
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Graduate Program in Microbiology & Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Caroline M Grunenwald
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Arianna I Celis
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | | | - Jennifer L DuBois
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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