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Yang J, Zhao Y, Qian L, Yu Y, Zhang Y, Zhang J. Modularization of dual recognized CRISPR/Cas12a system for the detection of Staphylococcus aureus assisted by hydrazone chemistry. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134877. [PMID: 38901249 DOI: 10.1016/j.jhazmat.2024.134877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/31/2024] [Accepted: 06/09/2024] [Indexed: 06/22/2024]
Abstract
In this work, a dual recognized CRISPR/Cas12a system has been proposed, in which the activation chain is cleverly divided into two parts that can serve for precise dual target recognition, and hydrazone chemistry is introduced for the formation of a whole activation chain. It has been further explored to construct a new method for the specific and sensitive detection of Staphylococcus aureus (SA) as one of the most common pathogens in infectious diseases. In virtue of proximity effect contributed by complementary base pairing, hydrazone chemistry accelerates the formation of the whole activation strand and improves the specificity of the CRISPR/Cas12a system, serving for the accurate analysis of SA. Moreover, the temporary aggregation of CRISPR/Cas12a around SA enhances its catalytical efficiency so as to further amplify signal. With high sensitivity, stability, reproducibility and specificity, the established method has been successfully applied to detect SA in complex substrates. Meanwhile, our established method can well evaluate the inhibition effect of chlorogenic acid and congo red in comparison with flow cytometry. ENVIRONMENTAL IMPLICATION: Bacterial pathogens exist widely in the environment and seriously threaten the safety of human health. Staphylococcus aureus (SA) is the most common pathogen of human suppurative infection, which can cause local suppurative infection, pneumonia, and even systemic infections such as sepsis. In this work, a dual recognized CRISPR/Cas12a system mediated by hydrazone chemistry has been proposed. With high sensitivity and low detection limit, the established method can specifically detect SA and effectively evaluate the antibacterial effect of inhibitors. This method is expected to be further developed into a detection method in different scenarios such as environmental monitoring and clinical diagnosis.
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Affiliation(s)
- Jingyi Yang
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Yining Zhao
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Lelin Qian
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Ying Yu
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China; Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Yuan Zhang
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Juan Zhang
- Center for Molecular Recognition and Biosensing, Joint International Research Laboratory of Biomaterials and Biotechnology in Organ Repair, Ministry of Education, Shanghai Engineering Research Center of Organ Repair, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
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Luo Z, Li P, Zhang D, Zhu J, Wang W, Zhao W, Li P, Yuan G. A Novel Antimicrobial Mechanism of Azalomycin F Acting on Lipoteichoic Acid Synthase and Cell Envelope. Molecules 2024; 29:856. [PMID: 38398608 PMCID: PMC10893547 DOI: 10.3390/molecules29040856] [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: 12/16/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Lipoteichoic acid (LTA) plays an essential role in bacterial growth and resistance to antibiotics, and LTA synthetase (LtaS) was considered as an attractive target for combating Gram-positive infections. Azalomycin F, a natural guanidyl-containing polyhydroxy macrolide, can target the LTA of Staphylococcus aureus. Using various technologies including enzyme-linked immunosorbent assay, transmission electron microscope, proteomics, and parallel reaction monitoring, here, the experimental results indicated that azalomycin F can accelerate the LTA release and disrupt the cell envelope, which would also lead to the feedback upregulation on the expressions of LtaS and other related enzymes. Simultaneously, the reconstituted enzyme activity evaluations showed that azalomycin F can significantly inhibit the extracellular catalytic domain of LtaS (eLtaS), while this was vague for LtaS embedded in the liposomes. Subsequently, the fluorescence analyses for five incubation systems containing azalomycin F and eLtaS or the LtaS-embedded liposome indicated that azalomcyin F can spontaneously bind to the active center of LtaS. Combining the mass spectroscopy analyses and the molecular dockings, the results further indicated that this interaction involves the binding sites of substrates and the LTA prolongation, especially the residues Lys299, Phe353, Trp354 and His416. All these suggested that azalomycin F has multiple antibacterial mechanisms against S. aureus. It can not only inhibit LTA biosynthesis through the interactions of its guanidyl side chain with the active center of LtaS but also disrupt the cell envelope through the synergistic effect of accelerating the LTA release, damaging the cell membrane, and electrostatically interacting with LTA. Simultaneously, these antibacterial mechanisms exhibit a synergistic inhibition effect on S. aureus cells, which would eventually cause the cellular autolysis.
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Affiliation(s)
- Zilong Luo
- Biotechnological Engineering Center for Pharmaceutical Research and Development, Jiangxi Agricultural University, Nanchang 330045, China
| | - Pingyi Li
- Biotechnological Engineering Center for Pharmaceutical Research and Development, Jiangxi Agricultural University, Nanchang 330045, China
| | - Duoduo Zhang
- Biotechnological Engineering Center for Pharmaceutical Research and Development, Jiangxi Agricultural University, Nanchang 330045, China
| | - Jianping Zhu
- Laboratory of Natural Medicine and Microbiological Drug, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
| | - Wan Wang
- School of Basic Medicine, Nanchang Medical College, Nanchang 330006, China
| | - Wenjia Zhao
- Biotechnological Engineering Center for Pharmaceutical Research and Development, Jiangxi Agricultural University, Nanchang 330045, China
| | - Peibo Li
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Ganjun Yuan
- Biotechnological Engineering Center for Pharmaceutical Research and Development, Jiangxi Agricultural University, Nanchang 330045, China
- Laboratory of Natural Medicine and Microbiological Drug, College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China
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3
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Sahoo J, Sahoo S, Subramaniam Y, Bhatt P, Rana S, De M. Photo-Controlled Gating of Selective Bacterial Membrane Interaction and Enhanced Antibacterial Activity for Wound Healing. Angew Chem Int Ed Engl 2024; 63:e202314804. [PMID: 37955346 DOI: 10.1002/anie.202314804] [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: 10/03/2023] [Revised: 11/11/2023] [Accepted: 11/13/2023] [Indexed: 11/14/2023]
Abstract
Reversible biointerfaces are essential for on-demand molecular recognition to regulate stimuli-responsive bioactivity such as specific interactions with cell membranes. The reversibility on a single platform allows the smart material to kill pathogens or attach/detach cells. Herein, we introduce a 2D-MoS2 functionalized with cationic azobenzene that interacts selectively with either Gram-positive or Gram-negative bacteria in a light-gated fashion. The trans conformation (trans-Azo-MoS2 ) selectively kills Gram-negative bacteria, whereas the cis form (cis-Azo-MoS2 ), under UV light, exhibits antibacterial activity against Gram-positive strains. The mechanistic investigation indicates that the cis-Azo-MoS2 exhibits higher affinity towards the membrane of Gram-positive bacteria compared to trans-Azo-MoS2 . In case of Gram-negative bacteria, trans-Azo-MoS2 internalizes more efficiently than cis-Azo-MoS2 and generates intracellular ROS to kill the bacteria. While the trans-Azo-MoS2 exhibits strong electrostatic interactions and internalizes faster into Gram-negative bacterial cells, cis-Azo-MoS2 primarily interacts with Gram-positive bacteria through hydrophobic and H-bonding interactions. The difference in molecular mechanism leads to photo-controlled Gram-selectivity and enhanced antibacterial activity. We found strain-specific and high bactericidal activity (minimal bactericidal concentration, 0.65 μg/ml) with low cytotoxicity, which we extended to wound healing applications. This methodology provides a single platform for efficiently switching between conformers to reversibly control the strain-selective bactericidal activity regulated by light.
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Affiliation(s)
- Jagabandhu Sahoo
- Department of Organic Chemistry, Indian Institute of Science, Bengaluru, 560012, India
| | - Soumyashree Sahoo
- Department of Organic Chemistry, Indian Institute of Science, Bengaluru, 560012, India
| | | | - Preeti Bhatt
- Materials Research Centre, Indian Institute of Science, Bengaluru, 560012, India
| | - Subinoy Rana
- Materials Research Centre, Indian Institute of Science, Bengaluru, 560012, India
| | - Mrinmoy De
- Department of Organic Chemistry, Indian Institute of Science, Bengaluru, 560012, India
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4
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She P, Yang Y, Li L, Li Y, Liu S, Li Z, Zhou L, Wu Y. Repurposing of the antimalarial agent tafenoquine to combat MRSA. mSystems 2023; 8:e0102623. [PMID: 38047647 PMCID: PMC10734505 DOI: 10.1128/msystems.01026-23] [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: 09/25/2023] [Accepted: 10/25/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE This study represents the first investigation into the antimicrobial effect of TAF against S. aureus and its potential mechanisms. Our data highlighted the effects of TAF against MRSA planktonic cells, biofilms, and persister cells, which is conducive to broadening the application of TAF. Through mechanistic studies, we revealed that TAF targets bacterial cell membranes. In addition, the in vivo experiments in mice demonstrated the safety and antimicrobial efficacy of TAF, suggesting that TAF could be a potential antibacterial drug candidate for the treatment of infections caused by multiple drug-resistant S. aureus.
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Affiliation(s)
- Pengfei She
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Yifan Yang
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Linhui Li
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Yimin Li
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Shasha Liu
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Zehao Li
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Linying Zhou
- Department of Laboratory Medicine, The Affiliated Changsha Hospital of Xiangya School of Medicine (The First Hospital of Changsha), Central South University, Changsha, China
| | - Yong Wu
- Department of Laboratory Medicine, The Affiliated Changsha Hospital of Xiangya School of Medicine (The First Hospital of Changsha), Central South University, Changsha, China
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5
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Douglas EA, Marshall B, Alghamadi A, Joseph EA, Duggan S, Vittorio S, De Luca L, Serpi M, Laabei M. Improved Antibacterial Activity of 1,3,4-Oxadiazole-Based Compounds That Restrict Staphylococcus aureus Growth Independent of LtaS Function. ACS Infect Dis 2023; 9:2141-2159. [PMID: 37828912 PMCID: PMC10644342 DOI: 10.1021/acsinfecdis.3c00250] [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: 05/31/2023] [Indexed: 10/14/2023]
Abstract
The lipoteichoic acid (LTA) biosynthesis pathway has emerged as a promising antimicrobial therapeutic target. Previous studies identified the 1,3,4 oxadiazole compound 1771 as an LTA inhibitor with activity against Gram-positive pathogens. We have succeeded in making six 1771 derivatives and, through subsequent hit validation, identified the incorporation of a pentafluorosulfanyl substituent as central in enhancing activity. Our newly described derivative, compound 13, showed a 16- to 32-fold increase in activity compared to 1771 when tested against a cohort of multidrug-resistant Staphylococcus aureus strains while simultaneously exhibiting an improved toxicity profile against mammalian cells. Molecular techniques were employed in which the assumed target, lipoteichoic acid synthase (LtaS), was both deleted and overexpressed. Neither deletion nor overexpression of LtaS altered 1771 or compound 13 susceptibility; however, overexpression of LtaS increased the MIC of Congo red, a previously identified LtaS inhibitor. These data were further supported by comparing the docking poses of 1771 and derivatives in the LtaS active site, which indicated the possibility of an additional target(s). Finally, we show that both 1771 and compound 13 have activity that is independent of LtaS, extending to cover Gram-negative species if the outer membrane is first permeabilized, challenging the classification that these compounds are strict LtaS inhibitors.
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Affiliation(s)
| | - Brandon Marshall
- School
of Chemistry, Cardiff University, Cardiff CF10 3AT, Wales, U.K.
| | - Arwa Alghamadi
- School
of Chemistry, Cardiff University, Cardiff CF10 3AT, Wales, U.K.
| | - Erin A. Joseph
- School
of Chemistry, Cardiff University, Cardiff CF10 3AT, Wales, U.K.
| | - Seána Duggan
- Medical
Research Council Centre for Medical Mycology at the University of
Exeter, University of Exeter, Exeter EX4 4DQ, U.K.
| | - Serena Vittorio
- Department
of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina I-98125, Italy
| | - Laura De Luca
- Department
of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina I-98125, Italy
| | - Michaela Serpi
- School
of Chemistry, Cardiff University, Cardiff CF10 3AT, Wales, U.K.
| | - Maisem Laabei
- Department
of Life Sciences, University of Bath, Bath BA2 7AY, U.K.
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6
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Jeong GJ, Khan F, Tabassum N, Cho KJ, Kim YM. Controlling biofilm and virulence properties of Gram-positive bacteria by targeting wall teichoic acid and lipoteichoic acid. Int J Antimicrob Agents 2023; 62:106941. [PMID: 37536571 DOI: 10.1016/j.ijantimicag.2023.106941] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/05/2023]
Abstract
Wall teichoic acid (WTA) and lipoteichoic acid (LTA) are structural components of Gram-positive bacteria's peptidoglycan and cell membrane, which are mostly anionic glycopolymers. WTA confers numerous physiological, virulence, and pathogenic features to bacterial pathogens. It controls cell shape, cell division, and the localisation of autolytic enzymes and ion homeostasis. In the context of virulence and pathogenicity, it aids bacterial cell attachment and colonisation and protects against the host defence system and antibiotics. Having such a broad function in pathogenic bacteria's lifecycle, WTA/LTA become one of the potential targets for antibacterial agents to reduce bacterial infection in the host. The number of reports for targeting the WTA/LTA pathway has risen, mostly by focusing on three distinct targets: antivirulence targets, β-lactam potentiator targets, and essential targets. The current review looked at the role of WTA/LTA in biofilm development and virulence in a range of Gram-positive pathogenic bacteria. Furthermore, alternate strategies, such as the application of natural and synthetic compounds that target the WTA/LTA pathway, have been thoroughly discussed. Moreover, the application of nanomaterials and a combination of drugs have also been discussed as a viable method for targeting the WTA/LTA in numerous Gram-positive bacteria. In addition, a future perspective for controlling bacterial infection by targeting the WTA/LTA is proposed.
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Affiliation(s)
- Geum-Jae Jeong
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
| | - Fazlurrahman Khan
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
| | - Nazia Tabassum
- Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea
| | - Kyung-Jin Cho
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea
| | - Young-Mog Kim
- Department of Food Science and Technology, Pukyong National University, Busan, Republic of Korea; Marine Integrated Biomedical Technology Center, The National Key Research Institutes in Universities, Pukyong National University, Busan, 48513, Republic of Korea; Research Center for Marine Integrated Bionics Technology, Pukyong National University, Busan 48513, Republic of Korea.
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7
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Wang L, Li A, Fang J, Wang Y, Chen L, Qiao L, Wang W. Enhanced Cell Wall and Cell Membrane Activity Promotes Heat Adaptation of Enterococcus faecium. Int J Mol Sci 2023; 24:11822. [PMID: 37511581 PMCID: PMC10380804 DOI: 10.3390/ijms241411822] [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: 06/14/2023] [Revised: 07/09/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023] Open
Abstract
Enterococcus faecium (E. faecium) is widely used in foods and is known as a probiotic to treat or prevent diarrhea in pets and livestock. However, the poor resistance of E. faecium to high temperature processing procedures limits its use. Strain domestication is a low-cost and effective method to obtain high-temperature-resistant strains. In this study, heat treatment was performed from 45 °C to 70 °C and the temperature was gradually increased by 5 °C every 3 days. After domestication, the survival rates of the high temperature adaptation strain RS047-wl under 65 °C water bath for 40 min was 11.5 times higher than WT RS047. Moreover, the saturated fatty acid (SFA) contents in cell membrane and the cell volume significantly increased in the RS047-wl. The combined transcriptomic, metabolomic, and proteomics analysis results showed a significant enhancement of cell wall and membrane synthesis ability in the RS047-wl. In conclusion, one of the main factors contributing to the improved high temperature resistance of RS047-wl was its enhanced ability to synthesize cell wall and membrane, which helped maintain normal cell morphology. Developing a high-temperature-resistant strain and understanding its mechanism enables it to adapt to high temperatures. This lays the groundwork for its future development and application.
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Affiliation(s)
- Li Wang
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Aike Li
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
| | - Jun Fang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Yongwei Wang
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
| | - Lixian Chen
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
| | - Lin Qiao
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
| | - Weiwei Wang
- Academy of National Food and Strategic Reserves Administration, Beijing 100037, China
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8
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Douglas EJA, Wulandari SW, Lovell SD, Laabei M. Novel antimicrobial strategies to treat multi-drug resistant Staphylococcus aureus infections. Microb Biotechnol 2023; 16:1456-1474. [PMID: 37178319 PMCID: PMC10281381 DOI: 10.1111/1751-7915.14268] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Antimicrobial resistance is a major obstacle for the treatment of infectious diseases and currently represents one of the most significant threats to global health. Staphylococcus aureus remains a formidable human pathogen with high mortality rates associated with severe systemic infections. S. aureus has become notorious as a multidrug resistant bacterium, which when combined with its extensive arsenal of virulence factors that exacerbate disease, culminates in an incredibly challenging pathogen to treat clinically. Compounding this major health issue is the lack of antibiotic discovery and development, with only two new classes of antibiotics approved for clinical use in the last 20 years. Combined efforts from the scientific community have reacted to the threat of dwindling treatment options to combat S. aureus disease in several innovative and exciting developments. This review describes current and future antimicrobial strategies aimed at treating staphylococcal colonization and/or disease, examining therapies that show significant promise at the preclinical development stage to approaches that are currently being investigated in clinical trials.
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9
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Zeden MS, Gallagher LA, Bueno E, Nolan AC, Ahn J, Shinde D, Razvi F, Sladek M, Burke Ó, O’Neill E, Fey PD, Cava F, Thomas VC, O’Gara JP. Metabolic reprogramming and altered cell envelope characteristics in a pentose phosphate pathway mutant increases MRSA resistance to β-lactam antibiotics. PLoS Pathog 2023; 19:e1011536. [PMID: 37486930 PMCID: PMC10399904 DOI: 10.1371/journal.ppat.1011536] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 08/03/2023] [Accepted: 07/04/2023] [Indexed: 07/26/2023] Open
Abstract
Central metabolic pathways control virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with physiologically-relevant concentrations of glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. The pgl mutation reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Levels of lipoteichoic acids (LTAs) were significantly reduced in pgl, which may limit cell lysis, while the surface charge of pgl cells was significantly more positive. A vraG mutation in pgl reversed the increased OX resistance phenotype, and partially restored wild-type surface charge, but not LTA levels. Mutations in vraF or graRS from the VraFG/GraRS complex that regulates DltABCD-mediated d-alanylation of teichoic acids (which in turn controls β-lactam resistance and surface charge), also restored wild-type OX susceptibility. Collectively these data show that reduced levels of LTAs and OX-induced lysis combined with a VraFG/GraRS-dependent increase in cell surface positive charge are accompanied by significantly increased OX resistance in an MRSA pgl mutant.
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Affiliation(s)
- Merve S. Zeden
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Laura A. Gallagher
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Emilio Bueno
- Department of Molecular Biology, Umeå University, MIMS—Laboratory for Molecular Infection Medicine Sweden, Umeå, Sweden
| | - Aaron C. Nolan
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Jongsam Ahn
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Dhananjay Shinde
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Fareha Razvi
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Margaret Sladek
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Órla Burke
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | - Eoghan O’Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Felipe Cava
- Department of Molecular Biology, Umeå University, MIMS—Laboratory for Molecular Infection Medicine Sweden, Umeå, Sweden
| | - Vinai C. Thomas
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - James P. O’Gara
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
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10
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Serpi M, Pertusati F, Morozzi C, Novelli G, Giannantonio D, Duggan K, Vittorio S, Fallis IA, De Luca L, Williams D. Synthesis, molecular docking and antibacterial activity of an oxadiazole-based lipoteichoic acid inhibitor and its metabolites. J Mol Struct 2023; 1278:None. [PMID: 38312219 PMCID: PMC10836577 DOI: 10.1016/j.molstruc.2023.134977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 01/16/2023]
Abstract
Amongst drug resistant Gram-positive bacteria, Staphylococcus aureus is a pathogen of great concern as it is the leading cause of life-threatening nosocomial and community acquired infections which are often associated with implanted medical devices. The biosynthesis of lipotheicoic acid (LTA) by S. aureus has been recognized as a promising antibacterial target, owing its critical role in the growth and survival of Gram-positive bacteria. Here we report for the first time the chemical synthesis and characterisation of an oxadiazole based compound (1771), previously described as an inhibitor of LTA biosynthesis by targeting Lta synthase enzyme (LtaS). To investigate its controversial mode of action, we also performed molecular docking studies, which indicated that 1771 behaves as a competitive inhibitor against LtaS. We also synthesised and evaluated the antimicrobial activity of 1771 metabolites which we have identified from its decomposition in mouse serum, proving that the biological activity was caused by intact 1771.
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Affiliation(s)
- Michaela Serpi
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, Wales CF10 3AT, United Kingdom
| | - Fabrizio Pertusati
- School of Pharmacy and Pharmaceutical Sciences, Redwood Building, King Edwards VII avenue, Cardiff, Wales CF10 3NB, United Kingdom
| | - Chiara Morozzi
- School of Pharmacy and Pharmaceutical Sciences, Redwood Building, King Edwards VII avenue, Cardiff, Wales CF10 3NB, United Kingdom
| | - Giulia Novelli
- School of Pharmacy and Pharmaceutical Sciences, Redwood Building, King Edwards VII avenue, Cardiff, Wales CF10 3NB, United Kingdom
| | - Daniele Giannantonio
- School of Pharmacy and Pharmaceutical Sciences, Redwood Building, King Edwards VII avenue, Cardiff, Wales CF10 3NB, United Kingdom
| | - Katrina Duggan
- Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff, United Kingdom
| | - Serena Vittorio
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno D'Alcontres 31, Messina I-98125, Italy
| | - Ian A. Fallis
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, Wales CF10 3AT, United Kingdom
| | - Laura De Luca
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Viale F. Stagno D'Alcontres 31, Messina I-98125, Italy
| | - David Williams
- Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff, United Kingdom
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11
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Zeden MS, Gallagher LA, Bueno E, Nolan AC, Ahn J, Shinde D, Razvi F, Sladek M, Burke Ó, O'Neill E, Fey PD, Cava F, Thomas VC, O'Gara JP. Metabolic reprogramming and flux to cell envelope precursors in a pentose phosphate pathway mutant increases MRSA resistance to β-lactam antibiotics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.03.530734. [PMID: 36945400 PMCID: PMC10028837 DOI: 10.1101/2023.03.03.530734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Central metabolic pathways controls virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. Further evidence of the pleiotropic effect of the pgl mutation was reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Reduced binding of wheat germ agglutinin (WGA) to pgl was indicative of lower wall teichoic acid/lipoteichoic acid levels or altered teichoic acid structures. Mutations in the vraFG or graRS loci reversed the increased OX resistance phenotype and restored WGA binding to wild-type levels. VraFG/GraRS was previously implicated in susceptibility to cationic antimicrobial peptides and vancomycin, and these data reveal a broader role for this multienzyme membrane complex in the export of cell envelope precursors or modifying subunits required for resistance to diverse antimicrobial agents. Altogether our study highlights important roles for the PPP and VraFG/GraRS in β-lactam resistance, which will support efforts to identify new drug targets and reintroduce β-lactams in combination with adjuvants or other antibiotics for infections caused by MRSA and other β-lactam resistant pathogens. Author summary High-level resistance to penicillin-type (β-lactam) antibiotics significantly limits the therapeutic options for patients with MRSA infections necessitating the use of newer agents, for which reduced susceptibility has already been described. Here we report for the first time that the central metabolism pentose phosphate pathway controls MRSA resistance to penicillin-type antibiotics. We comprehensively demonstrated that mutation of the PPP gene pgl perturbed metabolism in MRSA leading to increased flux to cell envelope precursors to drive increased antibiotic resistance. Moreover, increased resistance was dependent on the VraRG/GraRS multienzyme membrane complex previously implicated in resistance to antimicrobial peptides and vancomycin. Our data thus provide new insights on MRSA mechanisms of β-lactam resistance, which will support efforts to expand the treatment options for infections caused by this and other antimicrobial resistant pathogens.
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12
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Li X, Cai Y, Xia Q, Liao Y, Qin R. Antibacterial sensitizers from natural plants: A powerful weapon against methicillin-resistant Staphylococcus aureus. Front Pharmacol 2023; 14:1118793. [PMID: 36909155 PMCID: PMC9998539 DOI: 10.3389/fphar.2023.1118793] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/13/2023] [Indexed: 02/26/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a drug-resistant bacterium that can cause a range of infections with high morbidity and mortality, including pneumonia, etc. Therefore, development of new drugs or therapeutic strategies against MRSA is urgently needed. Increasing evidence has shown that combining antibiotics with "antibacterial sensitizers" which itself has no effect on MRSA, is highly effective against MRSA. Many studies showed the development of antibacterial sensitizers from natural plants may be a promising strategy against MRSA because of their low side effects, low toxicity and multi-acting target. In our paper, we first reviewed the resistance mechanisms of MRSA including "Resistance to Beta-Lactams", "Resistance to Glycopeptide antibiotics", "Resistance to Macrolides, Aminoglycosides, and Oxazolidinones" etc. Moreover, we summarized the possible targets for antibacterial sensitizers against MRSA. Furthermore, we reviewed the synergy effects of active monomeric compounds from natural plants combined with antibiotics against MRSA and their corresponding mechanisms over the last two decades. This review provides a novel approach to overcome antibiotic resistance in MRSA.
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Affiliation(s)
- Xiaoli Li
- Department of Pharmacology, College of Pharmacy, Chongqing Medical University, Chongqing, China.,Chongqing Key Laboratory of Drug Metabolism, Chongqing, China
| | - Yongqing Cai
- Department of Pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Qinchuan Xia
- Fuan Pharmaceutical Group Chongqing Bosen Pharmaceutical Co., Ltd., Chongqing, China
| | - Yongqun Liao
- Fuan Pharmaceutical Group Chongqing Bosen Pharmaceutical Co., Ltd., Chongqing, China
| | - Rongxin Qin
- Department of Pharmacology, College of Pharmacy, Army Medical University (The Third Military Medical University), Chongqing, China
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13
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Kepplinger B, Wen X, Tyler AR, Kim BY, Brown J, Banks P, Dashti Y, Mackenzie ES, Wills C, Kawai Y, Waldron KJ, Allenby NEE, Wu LJ, Hall MJ, Errington J. Mirubactin C rescues the lethal effect of cell wall biosynthesis mutations in Bacillus subtilis. Front Microbiol 2022; 13:1004737. [PMID: 36312962 PMCID: PMC9609785 DOI: 10.3389/fmicb.2022.1004737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/22/2022] [Indexed: 01/29/2023] Open
Abstract
Growth of most rod-shaped bacteria is accompanied by the insertion of new peptidoglycan into the cylindrical cell wall. This insertion, which helps maintain and determine the shape of the cell, is guided by a protein machine called the rod complex or elongasome. Although most of the proteins in this complex are essential under normal growth conditions, cell viability can be rescued, for reasons that are not understood, by the presence of a high (mM) Mg2+ concentration. We screened for natural product compounds that could rescue the growth of mutants affected in rod-complex function. By screening > 2,000 extracts from a diverse collection of actinobacteria, we identified a compound, mirubactin C, related to the known iron siderophore mirubactin A, which rescued growth in the low micromolar range, and this activity was confirmed using synthetic mirubactin C. The compound also displayed toxicity at higher concentrations, and this effect appears related to iron homeostasis. However, several lines of evidence suggest that the mirubactin C rescuing activity is not due simply to iron sequestration. The results support an emerging view that the functions of bacterial siderophores extend well beyond simply iron binding and uptake.
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Affiliation(s)
- Bernhard Kepplinger
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Xin Wen
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew Robert Tyler
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Byung-Yong Kim
- Odyssey Therapeutics Inc., Newcastle upon Tyne, United Kingdom
| | - James Brown
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Peter Banks
- Faculty of Medical Sciences, Bioscience Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yousef Dashti
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Eilidh Sohini Mackenzie
- Faculty of Medical Sciences, Bioscience Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Corinne Wills
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yoshikazu Kawai
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kevin John Waldron
- Faculty of Medical Sciences, Bioscience Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Ling Juan Wu
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Michael John Hall
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Newcastle University, Newcastle upon Tyne, United Kingdom
- Odyssey Therapeutics Inc., Newcastle upon Tyne, United Kingdom
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14
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Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
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Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
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15
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Adaptive laboratory evolution and independent component analysis disentangle complex vancomycin adaptation trajectories. Proc Natl Acad Sci U S A 2022; 119:e2118262119. [PMID: 35858453 PMCID: PMC9335240 DOI: 10.1073/pnas.2118262119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Infections with methicillin-resistant Staphylococcus aureus (MRSA) are associated with significant morbidity and mortality. Vancomycin is a last-line antibiotic used to treat MRSA infections; however, strains with decreased susceptibility to vancomycin (vancomycin-intermediate S. aureus [VISA]) have been spreading, and VISA infections are associated with prolonged therapeutic treatment and treatment failure. To map out the evolutionary trajectory behind VISA development, we characterized the mutational, transcriptional, and phenotypic landscape of 10 lineages of S. aureus USA300 strain JE2 that evolved in parallel to vancomycin. We demonstrate that MRSA strains adapt to vancomycin by divergent pathways leading to high or low oxacillin susceptibility characterized by mutational or transcriptional profiles. Our results point to diagnostic possibilities that may support personalized antibiotic treatment regimes. Human infections with methicillin-resistant Staphylococcus aureus (MRSA) are commonly treated with vancomycin, and strains with decreased susceptibility, designated as vancomycin-intermediate S. aureus (VISA), are associated with treatment failure. Here, we profiled the phenotypic, mutational, and transcriptional landscape of 10 VISA strains adapted by laboratory evolution from one common MRSA ancestor, the USA300 strain JE2. Using functional and independent component analysis, we found that: 1) despite the common genetic background and environmental conditions, the mutational landscape diverged between evolved strains and included mutations previously associated with vancomycin resistance (in vraT, graS, vraFG, walKR, and rpoBCD) as well as novel adaptive mutations (SAUSA300_RS04225, ssaA, pitAR, and sagB); 2) the first wave of mutations affected transcriptional regulators and the second affected genes involved in membrane biosynthesis; 3) expression profiles were predominantly strain-specific except for sceD and lukG, which were the only two genes significantly differentially expressed in all clones; 4) three independent virulence systems (φSa3, SaeR, and T7SS) featured as the most transcriptionally perturbed gene sets across clones; 5) there was a striking variation in oxacillin susceptibility across the evolved lineages (from a 10-fold increase to a 63-fold decrease) that also arose in clinical MRSA isolates exposed to vancomycin and correlated with susceptibility to teichoic acid inhibitors; and 6) constitutive expression of the VraR regulon explained cross-susceptibility, while mutations in walK were associated with cross-resistance. Our results show that adaptation to vancomycin involves a surprising breadth of mutational and transcriptional pathways that affect antibiotic susceptibility and possibly the clinical outcome of infections.
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16
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Ali SR, De M. Superparamagnetic Nickel Nanocluster-Embedded MoS 2 Nanosheets for Gram-Selective Bacterial Adhesion and Antibacterial Activity. ACS Biomater Sci Eng 2022; 8:2932-2942. [PMID: 35666676 DOI: 10.1021/acsbiomaterials.2c00257] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Ever increasing infectious diseases caused by pathogenic bacteria are creating one of the greatest health problems. The extensive use of numerous antibiotics and antimicrobial agents has prompted the growth of multidrug-resistant bacterial strains. The ancient biomedical application of metals and the recent advancement in the field of nanotechnology have encouraged us to explore the antimicrobial activity of nanomaterials. Herein, we have synthesized a magnetically separable superparamagnetic nickel nanocluster-loaded two-dimensional molybdenum disulfide nanocomposite (Ni@2D-MoS2). It can selectively bind with Gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis over Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. After the functionalization of Ni@2D-MoS2 with a positively charged ligand, it showed an excellent Gram-selective antibacterial activity toward MRSA and E. faecalis. Furthermore, the superparamagnetic property of the synthesized material can be used for the simultaneous removal and killing of the microbes and recycled for further use. This study demonstrates strategies to develop hybrid antimicrobial nanomaterial systems for selective antibacterial activity with recyclability.
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Affiliation(s)
- Sk Rajab Ali
- Department of Organic Chemistry, Indian Institute of Science, CV Raman Road, Bangalore 560012, India
| | - Mrinmoy De
- Department of Organic Chemistry, Indian Institute of Science, CV Raman Road, Bangalore 560012, India
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17
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Chee Wezen X, Chandran A, Eapen RS, Waters E, Bricio-Moreno L, Tosi T, Dolan S, Millership C, Kadioglu A, Gründling A, Itzhaki LS, Welch M, Rahman T. Structure-Based Discovery of Lipoteichoic Acid Synthase Inhibitors. J Chem Inf Model 2022; 62:2586-2599. [PMID: 35533315 PMCID: PMC9131456 DOI: 10.1021/acs.jcim.2c00300] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Indexed: 01/20/2023]
Abstract
Lipoteichoic acid synthase (LtaS) is a key enzyme for the cell wall biosynthesis of Gram-positive bacteria. Gram-positive bacteria that lack lipoteichoic acid (LTA) exhibit impaired cell division and growth defects. Thus, LtaS appears to be an attractive antimicrobial target. The pharmacology around LtaS remains largely unexplored with only two small-molecule LtaS inhibitors reported, namely "compound 1771" and the Congo red dye. Structure-based drug discovery efforts against LtaS remain unattempted due to the lack of an inhibitor-bound structure of LtaS. To address this, we combined the use of a molecular docking technique with molecular dynamics (MD) simulations to model a plausible binding mode of compound 1771 to the extracellular catalytic domain of LtaS (eLtaS). The model was validated using alanine mutagenesis studies combined with isothermal titration calorimetry. Additionally, lead optimization driven by our computational model resulted in an improved version of compound 1771, namely, compound 4 which showed greater affinity for binding to eLtaS than compound 1771 in biophysical assays. Compound 4 reduced LTA production in S. aureus dose-dependently, induced aberrant morphology as seen for LTA-deficient bacteria, and significantly reduced bacteria titers in the lung of mice infected with S. aureus. Analysis of our MD simulation trajectories revealed the possible formation of a transient cryptic pocket in eLtaS. Virtual screening (VS) against the cryptic pocket led to the identification of a new class of inhibitors that could potentiate β-lactams against methicillin-resistant S. aureus. Our overall workflow and data should encourage further drug design campaign against LtaS. Finally, our work reinforces the importance of considering protein conformational flexibility to a successful VS endeavor.
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Affiliation(s)
- Xavier Chee Wezen
- Science
Program, School of Chemical Engineering and Science, Faculty of Engineering,
Computing and Science, Swinburne University
of Technology Sarawak, Kuching 93350, Malaysia
| | - Aneesh Chandran
- Department
of Biotechnology & Microbiology, Kannur
University, Kannur 670 661, Kerala, India
| | | | - Elaine Waters
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Laura Bricio-Moreno
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Tommaso Tosi
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Stephen Dolan
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Charlotte Millership
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Aras Kadioglu
- Department
of Clinical Infection Microbiology and Immunology, Institute of Infection
and Global Health, University of Liverpool, Liverpool L69 7BE, U.K.
| | - Angelika Gründling
- Section
of Molecular Microbiology and MRC Centre for Molecular Bacteriology
and Infection, Imperial College London, London SW7 2AZ, U.K.
| | - Laura S. Itzhaki
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
| | - Martin Welch
- Department
of Biochemistry, University of Cambridge, Cambridge CB2 1QW, U.K.
| | - Taufiq Rahman
- Department
of PharmacologyUniversity of CambridgeCambridgeCB2 1PDU.K.
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18
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Abstract
Cell division and cell wall synthesis in staphylococci need to be precisely coordinated and controlled to allow the cell to multiply while maintaining its nearly spherical shape. The mechanisms ensuring correct placement of the division plane and synthesis of new cell wall have been studied intensively. However, hitherto unknown factors and proteins are likely to play key roles in this complex interplay. Here, we identified and investigated a protein with a major influence on cell morphology in Staphylococcus aureus. The protein, named SmdA (for staphylococcal morphology determinant A), is a membrane protein with septum-enriched localization. By CRISPRi knockdown and overexpression combined with different microscopy techniques, we demonstrated that proper levels of SmdA were necessary for cell division, including septum formation and cell splitting. We also identified conserved residues in SmdA that were critical for its functionality. Pulldown and bacterial two-hybrid interaction experiments showed that SmdA interacted with several known cell division and cell wall synthesis proteins, including penicillin-binding proteins (PBPs) and EzrA. Notably, SmdA also affected susceptibility to cell wall targeting antibiotics, particularly in methicillin-resistant S. aureus (MRSA). Together, our results showed that S. aureus was dependent on balanced amounts of membrane attached SmdA to carry out proper cell division.
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19
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Naderi F, Orojloo M, Kamali S, Jannesar R, Amani S. Synthesis, Structural Characterization, in Vitro Biological Activity, and Computational Quantum Chemical Studies of New Cobalt (II), Nickel (II), and Copper (II) Complexes Based on an Azo-Azomethine Ligand. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2022.2049325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Fatemeh Naderi
- Chemistry Department, Faculty of Sciences, Arak University, Arak, Iran
| | - Masoumeh Orojloo
- Chemistry Department, Faculty of Sciences, Arak University, Arak, Iran
| | - Shirin Kamali
- Chemistry Department, Faculty of Sciences, Arak University, Arak, Iran
| | - Ramin Jannesar
- Department of Pathology, Yasuj University of Medical Sciences, Yasuj, Iran
- Department of Biotechnology and Microbial Nanotechnology, Dena Pathobiology Laboratory, Yasuj, Iran
| | - Saeid Amani
- Chemistry Department, Faculty of Sciences, Arak University, Arak, Iran
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20
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Muscato J, Morris HG, Mychack A, Rajagopal M, Baidin V, Hesser AR, Lee W, İnecik K, Wilson LJ, Kraml CM, Meredith TC, Walker S. Rapid Inhibitor Discovery by Exploiting Synthetic Lethality. J Am Chem Soc 2022; 144:3696-3705. [PMID: 35170959 PMCID: PMC9012225 DOI: 10.1021/jacs.1c12697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Synthetic lethality occurs when inactivation of two genes is lethal but inactivation of either single gene is not. This phenomenon provides an opportunity for efficient compound discovery. Using differential growth screens, one can identify biologically active compounds that selectively inhibit proteins within the synthetic lethal network of any inactivated gene. Here, based purely on synthetic lethalities, we identified two compounds as the only possible inhibitors of Staphylococcus aureus lipoteichoic acid (LTA) biosynthesis from a screen of ∼230,000 compounds. Both compounds proved to inhibit the glycosyltransferase UgtP, which assembles the LTA glycolipid anchor. UgtP is required for β-lactam resistance in methicillin-resistant S. aureus (MRSA), and the inhibitors restored sensitivity to oxacillin in a highly resistant S. aureus strain. As no other compounds were pursued as possible LTA glycolipid assembly inhibitors, this work demonstrates the extraordinary efficiency of screens that exploit synthetic lethality to discover compounds that target specified pathways. The general approach should be applicable not only to other bacteria but also to eukaryotic cells.
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Affiliation(s)
- Jacob
D. Muscato
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Heidi G. Morris
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Aaron Mychack
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Mithila Rajagopal
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States,Department
of Chemistry and Chemical Biology, Harvard
University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Vadim Baidin
- Department
of Chemistry and Chemical Biology, Harvard
University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Anthony R. Hesser
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Wonsik Lee
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Kemal İnecik
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Laura J. Wilson
- Lotus
Separations LLC, B20 Frick Chemistry Laboratory, Princeton, New Jersey 08544, United States
| | - Christina M. Kraml
- Lotus
Separations LLC, B20 Frick Chemistry Laboratory, Princeton, New Jersey 08544, United States
| | - Timothy C. Meredith
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States
| | - Suzanne Walker
- Department
of Microbiology, Harvard University, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, United States,Department
of Chemistry and Chemical Biology, Harvard
University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States,
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21
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Sahoo J, De M. Gram-Selective Antibacterial Activity of Mixed-Charge 2D-MoS2. J Mater Chem B 2022; 10:4588-4594. [DOI: 10.1039/d2tb00361a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Development of nanomaterial-based antibiotics can be the most potent alternative due to the increasing resistance against conventional antibiotics. But one of the important parameters in development of antibacterial agent is...
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22
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Pharmacokinetics of Azalomycin F, a Natural Macrolide Produced by Streptomycete Strains, in Rats. Molecules 2021; 26:molecules26216464. [PMID: 34770873 PMCID: PMC8588360 DOI: 10.3390/molecules26216464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/23/2021] [Accepted: 10/24/2021] [Indexed: 12/05/2022] Open
Abstract
As antimicrobial resistance has been increasing, new antimicrobial agents are desperately needed. Azalomycin F, a natural polyhydroxy macrolide, presents remarkable antimicrobial activities. To investigate its pharmacokinetic characteristics in rats, the concentrations of azalomycin F contained in biological samples, in vitro, were determined using a validated high-performance liquid chromatography–ultraviolet (HPLC-UV) method, and, in vivo, samples were assayed by an ultra-high performance liquid chromatography–tandem mass spectrometric (UPLC–MS/MS) method. Based on these methods, the pharmacokinetics of azalomycin F were first investigated. Its plasma concentration-time courses and pharmacokinetic parameters in rats were obtained by a non-compartment model for oral (26.4 mg/kg) and intravenous (2.2 mg/kg) administrations. The results indicate that the oral absolute bioavailability of azalomycin F is very low (2.39 ± 1.28%). From combinational analyses of these pharmacokinetic parameters, and of the results of the in-vitro absorption and metabolism experiments, we conclude that azalomycin F is absorbed relatively slowly and with difficulty by the intestinal tract, and subsequently can be rapidly distributed into the tissues and/or intracellular f of rats. Azalomycin F is stable in plasma, whole blood, and the liver, and presents plasma protein binding ratios of more than 90%. Moreover, one of the major elimination routes of azalomycin F is its excretion through bile and feces. Together, the above indicate that azalomycin F is suitable for administration by intravenous injection when used for systemic diseases, while, by oral administration, it can be used in the treatment of diseases of the gastrointestinal tract.
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Accumulation of Succinyl Coenzyme A Perturbs the Methicillin-Resistant Staphylococcus aureus (MRSA) Succinylome and Is Associated with Increased Susceptibility to Beta-Lactam Antibiotics. mBio 2021; 12:e0053021. [PMID: 34182779 PMCID: PMC8437408 DOI: 10.1128/mbio.00530-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Penicillin binding protein 2a (PBP2a)-dependent resistance to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA) is regulated by the activity of the tricarboxylic acid (TCA) cycle via a poorly understood mechanism. We report that mutations in sucC and sucD, but not other TCA cycle enzymes, negatively impact β-lactam resistance without changing PBP2a expression. Increased intracellular levels of succinyl coenzyme A (succinyl-CoA) in the sucC mutant significantly perturbed lysine succinylation in the MRSA proteome. Suppressor mutations in sucA or sucB, responsible for succinyl-CoA biosynthesis, reversed sucC mutant phenotypes. The major autolysin (Atl) was the most succinylated protein in the proteome, and increased Atl succinylation in the sucC mutant was associated with loss of autolytic activity. Although PBP2a and PBP2 were also among the most succinylated proteins in the MRSA proteome, peptidoglycan architecture and cross-linking were unchanged in the sucC mutant. These data reveal that perturbation of the MRSA succinylome impacts two interconnected cell wall phenotypes, leading to repression of autolytic activity and increased susceptibility to β-lactam antibiotics.
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Park OJ, Kwon Y, Park C, So YJ, Park TH, Jeong S, Im J, Yun CH, Han SH. Streptococcus gordonii: Pathogenesis and Host Response to Its Cell Wall Components. Microorganisms 2020; 8:microorganisms8121852. [PMID: 33255499 PMCID: PMC7761167 DOI: 10.3390/microorganisms8121852] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 02/08/2023] Open
Abstract
Streptococcus gordonii, a Gram-positive bacterium, is a commensal bacterium that is commonly found in the skin, oral cavity, and intestine. It is also known as an opportunistic pathogen that can cause local or systemic diseases, such as apical periodontitis and infective endocarditis. S. gordonii, an early colonizer, easily attaches to host tissues, including tooth surfaces and heart valves, forming biofilms. S. gordonii penetrates into root canals and blood streams, subsequently interacting with various host immune and non-immune cells. The cell wall components of S. gordonii, which include lipoteichoic acids, lipoproteins, serine-rich repeat adhesins, peptidoglycans, and cell wall proteins, are recognizable by individual host receptors. They are involved in virulence and immunoregulatory processes causing host inflammatory responses. Therefore, S.gordonii cell wall components act as virulence factors that often progressively develop diseases through overwhelming host responses. This review provides an overview of S. gordonii, and how its cell wall components could contribute to the pathogenesis and development of therapeutic strategies.
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Affiliation(s)
- Ok-Jin Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Yeongkag Kwon
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Chaeyeon Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Yoon Ju So
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Tae Hwan Park
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Sungho Jeong
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Jintaek Im
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
| | - Cheol-Heui Yun
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea;
- Institute of Green Bio Science Technology, Seoul National University, Pyeongchang 25354, Korea
| | - Seung Hyun Han
- Department of Oral Microbiology and Immunology, School of Dentistry, Dental Research Institute, Seoul National University, Seoul 08826, Korea; (O.-J.P.); (Y.K.); (C.P.); (Y.J.S.); (T.H.P.); (S.J.); (J.I.)
- Correspondence: ; Tel.: +82-2-880-2310
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25
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Lipoteichoic acid polymer length is determined by competition between free starter units. Proc Natl Acad Sci U S A 2020; 117:29669-29676. [PMID: 33172991 DOI: 10.1073/pnas.2008929117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Carbohydrate polymers exhibit incredible chemical and structural diversity, yet are produced by polymerases without a template to guide length and composition. As the length of carbohydrate polymers is critical for their biological functions, understanding the mechanisms that determine polymer length is an important area of investigation. Most Gram-positive bacteria produce anionic glycopolymers called lipoteichoic acids (LTA) that are synthesized by lipoteichoic acid synthase (LtaS) on a diglucosyl-diacylglycerol (Glc2DAG) starter unit embedded in the extracellular leaflet of the cell membrane. LtaS can use phosphatidylglycerol (PG) as an alternative starter unit, but PG-anchored LTA polymers are significantly longer, and cells that make these abnormally long polymers exhibit major defects in cell growth and division. To determine how LTA polymer length is controlled, we reconstituted Staphylococcus aureus LtaS in vitro. We show that polymer length is an intrinsic property of LtaS that is directly regulated by the identity and concentration of lipid starter units. Polymerization is processive, and the overall reaction rate is substantially faster for the preferred Glc2DAG starter unit, yet the use of Glc2DAG leads to shorter polymers. We propose a simple mechanism to explain this surprising result: free starter units terminate polymerization by displacing the lipid anchor of the growing polymer from its binding site on the enzyme. Because LtaS is conserved across most Gram-positive bacteria and is important for survival, this reconstituted system should be useful for characterizing inhibitors of this key cell envelope enzyme.
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26
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Pinto L, Torres C, Gil C, Santos HM, Capelo JL, Borges V, Gomes JP, Silva C, Vieira L, Poeta P, Igrejas G. Multiomics Substrates of Resistance to Emerging Pathogens? Transcriptome and Proteome Profile of a Vancomycin-Resistant Enterococcus faecalis Clinical Strain. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2020; 24:81-95. [PMID: 32073998 DOI: 10.1089/omi.2019.0164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Antibiotic resistance and hospital acquired infections are on the rise worldwide. Vancomycin-resistant enterococci have been reported in clinical settings in recent decades. In this multiomics study, we provide comprehensive proteomic and transcriptomic analyses of a vancomycin-resistant Enterococcus faecalis clinical isolate from a patient with a urinary tract infection. The previous genotypic profile of the strain C2620 indicated the presence of antibiotic resistance genes characteristic of the vanB cluster. To further investigate the transcriptome of this pathogenic strain, we used whole genome sequencing and RNA-sequencing to detect and quantify the genes expressed. In parallel, we used two-dimensional gel electrophoresis followed by MALDI-TOF/MS (Matrix-assisted laser desorption/ionization-Time-of-flight/Mass spectrometry) to identify the proteins in the proteome. We studied the membrane and cytoplasm subproteomes separately. From a total of 207 analysis spots, we identified 118 proteins. The protein list was compared to the results obtained from the full transcriptome assay. Several genes and proteins related to stress and cellular response were identified, as well as some linked to antibiotic and drug responses, which is consistent with the known state of multiresistance. Even though the correlation between transcriptome and proteome data is not yet fully understood, the use of multiomics approaches has proven to be increasingly relevant to achieve deeper insights into the survival ability of pathogenic bacteria found in health care facilities.
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Affiliation(s)
- Luís Pinto
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Carmen Torres
- Área de Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Concha Gil
- Departamento de Microbiologia II, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Hugo M Santos
- LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - José Luís Capelo
- LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Lisbon, Portugal
| | - Patrícia Poeta
- Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
| | - Gilberto Igrejas
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.,LAQV-REQUIMTE, Faculty of Science and Technology, Nova University of Lisbon, Lisbon, Portugal
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27
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Gökalp M, Dede B, Tilki T, Karabacak Atay Ç. Triazole based azo molecules as potential antibacterial agents: Synthesis, characterization, DFT, ADME and molecular docking studies. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128140] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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28
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Multiple ways to kill bacteria via inhibiting novel cell wall or membrane targets. Future Med Chem 2020; 12:1253-1279. [PMID: 32538147 DOI: 10.4155/fmc-2020-0046] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The rise of antibiotic-resistant infections has been well documented and the need for novel antibiotics cannot be overemphasized. US FDA approved antibiotics target only a small fraction of bacterial cell wall or membrane components, well-validated antimicrobial targets. In this review, we highlight small molecules that inhibit relatively unexplored cell wall and membrane targets. Some of these targets include teichoic acids-related proteins (DltA, LtaS, TarG and TarO), lipid II, Mur family enzymes, components of LPS assembly (MsbA, LptA, LptB and LptD), penicillin-binding protein 2a in methicillin-resistant Staphylococcus aureus, outer membrane protein transport (such as LepB and BamA) and lipoprotein transport components (LspA, LolC, LolD and LolE). Inhibitors of SecA, cell division protein, FtsZ and compounds that kill persister cells via membrane targeting are also covered.
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29
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Hesser AR, Matano LM, Vickery CR, Wood BM, Santiago AG, Morris HG, Do T, Losick R, Walker S. The length of lipoteichoic acid polymers controls Staphylococcus aureus cell size and envelope integrity. J Bacteriol 2020; 202:JB.00149-20. [PMID: 32482719 PMCID: PMC8404710 DOI: 10.1128/jb.00149-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/22/2020] [Indexed: 02/08/2023] Open
Abstract
The opportunistic pathogen Staphylococcus aureus is protected by a cell envelope that is crucial for viability. In addition to peptidoglycan, lipoteichoic acid (LTA) is an especially important component of the S. aureus cell envelope. LTA is an anionic polymer anchored to a glycolipid in the outer leaflet of the cell membrane. It was known that deleting the gene for UgtP, the enzyme that makes this glycolipid anchor, causes cell growth and division defects. In Bacillus subtilis, growth abnormalities from the loss of ugtP have been attributed to both the absence of the encoded protein and to the loss of its products. Here, we show that growth defects in S. aureus ugtP deletion mutants are due to the long, abnormal LTA polymer that is produced when the glycolipid anchor is missing from the outer leaflet of the membrane. Dysregulated cell growth leads to defective cell division, and these phenotypes are corrected by mutations in the LTA polymerase, ltaS, that reduce polymer length. We also show that S. aureus mutants with long LTA are sensitized to cell wall hydrolases, beta-lactam antibiotics, and compounds that target other cell envelope pathways. We conclude that control of LTA polymer length is important for S. aureus physiology and promotes survival under stressful conditions, including antibiotic stress.IMPORTANCE Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of community- and hospital-acquired infections and is responsible for a large fraction of deaths caused by antibiotic-resistant bacteria. S. aureus is surrounded by a complex cell envelope that protects it from antimicrobial compounds and other stresses. Here we show that controlling the length of an essential cell envelope polymer, lipoteichoic acid, is critical for controlling S. aureus cell size and cell envelope integrity. We also show that genes involved in LTA length regulation are required for resistance to beta-lactam antibiotics in MRSA. The proteins encoded by these genes may be targets for combination therapy with an appropriate beta-lactam.
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Affiliation(s)
- Anthony R Hesser
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Leigh M Matano
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | | | - B McKay Wood
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Ace George Santiago
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Heidi G Morris
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Truc Do
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Richard Losick
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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30
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Lipoteichoic Acid Biosynthesis Inhibitors as Potent Inhibitors of S. aureus and E. faecalis Growth and Biofilm Formation. Molecules 2020; 25:molecules25102277. [PMID: 32408616 PMCID: PMC7287929 DOI: 10.3390/molecules25102277] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 01/04/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE) have been deemed as serious threats by the CDC. Many chronic MRSA and VRE infections are due to biofilm formation. Biofilm are considered to be between 10–10,000 times more resistant to antibiotics, and therefore new chemical entities that inhibit and/or eradicate biofilm formation are needed. Teichoic acids, such as lipoteichoic acids (LTAs) and wall teichoic acids (WTAs), play pivotal roles in Gram-positive bacteria’s ability to grow, replicate, and form biofilms, making the inhibition of these teichoic acids a promising approach to fight infections by biofilm forming bacteria. Here, we describe the potent biofilm inhibition activity against MRSA and VRE biofilms by two LTA biosynthesis inhibitors HSGN-94 and HSGN-189 with MBICs as low as 0.0625 µg/mL against MRSA biofilms and 0.5 µg/mL against VRE biofilms. Additionally, both HSGN-94 and HSGN-189 were shown to potently synergize with the WTA inhibitor Tunicamycin in inhibiting MRSA and VRE biofilm formation.
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31
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Gabryszewski SJ, Wong Fok Lung T, Annavajhala MK, Tomlinson KL, Riquelme SA, Khan IN, Noguera LP, Wickersham M, Zhao A, Mulenos AM, Peaper D, Koff JL, Uhlemann AC, Prince A. Metabolic Adaptation in Methicillin-Resistant Staphylococcus aureus Pneumonia. Am J Respir Cell Mol Biol 2020; 61:185-197. [PMID: 30742488 PMCID: PMC6670030 DOI: 10.1165/rcmb.2018-0389oc] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a versatile human pathogen that is associated with diverse types of infections ranging from benign colonization to sepsis. We postulated that MRSA must undergo specific genotypic and phenotypic changes to cause chronic pulmonary disease. We investigated how MRSA adapts to the human airway to establish chronic infection, as occurs during cystic fibrosis (CF). MRSA isolates from patients with CF that were collected over a 4-year period were analyzed by whole-genome sequencing, transcriptional analysis, and metabolic studies. Persistent MRSA infection was associated with staphylococcal metabolic adaptation, but not changes in immunogenicity. Adaptation was characterized by selective use of the tricarboxylic acid cycle cycle and generation of biofilm, a means of limiting oxidant stress. Increased transcription of specific metabolic genes was conserved in all host-adapted strains, most notably a 10,000-fold increase in fumC, which catalyzes the interconversion of fumarate and malate. Elevated fumarate levels promoted in vitro biofilm production in clinical isolates. Host-adapted strains preferred to assimilate glucose polymers and pyruvate, which can be metabolized to generate N-acetylglucosamine polymers that comprise biofilm. MRSA undergoes substantial metabolic adaptation to the human airway to cause chronic pulmonary infection, and selected metabolites may be useful therapeutically to inhibit infection.
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Affiliation(s)
| | | | - Medini K Annavajhala
- 2Department of Medicine, and.,3Microbiome and Pathogen Genomics Core, Department of Medicine, Columbia University Irving Medical Center, New York, New York; and
| | | | | | | | | | | | | | | | - David Peaper
- 5Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut
| | | | - Anne-Catrin Uhlemann
- 2Department of Medicine, and.,3Microbiome and Pathogen Genomics Core, Department of Medicine, Columbia University Irving Medical Center, New York, New York; and
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32
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Yuan G, Li P, Xu X, Li P, Zhong Q, He S, Yi H, Yi W, Guan Y, Wen ZT. Azalomycin F 5a Eradicates Staphylococcus aureus Biofilm by Rapidly Penetrating and Subsequently Inducing Cell Lysis. Int J Mol Sci 2020; 21:ijms21030862. [PMID: 32013221 PMCID: PMC7036916 DOI: 10.3390/ijms21030862] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/24/2020] [Accepted: 01/28/2020] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial resistance has emerged as a serious threat to public health. Bacterial biofilm, as a natural lifestyle, is a major contributor to resistance to antimicrobials. Azalomycin F5a, a natural guanidine-containing polyhydroxy macrolide, has remarkable activities against Gram-positive bacteria, including Staphylococcus aureus, a major causative agent of hospital-acquired infections. To further evaluate its potential to be developed as a new antimicrobial agent, its influence on S. aureus biofilm formation was evaluated using the crystal violet method, and then its eradication effect against mature biofilms was determined by confocal laser scanning microscopy, the drop plate method, and regrowth experiments. The results showed that azalomycin F5a could significantly inhibit S. aureus biofilm formation, and such effects were concentration dependent. In addition, it can also eradicate S. aureus mature biofilms with the minimum biofilm eradication concentration of 32.0 μg/mL. As extracellular deoxyribonucleic acid (eDNA) plays important roles in the structural integrity of bacterial biofilm, its influence on the eDNA release in S. aureus biofilm was further analyzed using gel electrophoresis. Combined with our previous works, these results indicate that azalomycin F5a could rapidly penetrate biofilm and causes damages to the cell membrane, leading to an increase in DNase release and eventually eradicating S. aureus biofilm.
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Affiliation(s)
- Ganjun Yuan
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA 70119, USA
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70119, USA
- Correspondence: (G.Y.); (Z.T.W.); Tel.: +86-791-83813459 (G.Y.); +1-504-9418465 (Z.T.W.)
| | - Pingyi Li
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Xuejie Xu
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Peibo Li
- School of Life Sciences, Sun Yat-sen University, 135 Xingang Road, Guangzhou 510275, China
| | - Qiwang Zhong
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Su He
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Houqin Yi
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Wenfang Yi
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Yingying Guan
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, China; (P.L.); (Q.Z.)
| | - Zezhang Tom Wen
- Department of Oral and Craniofacial Biology, Louisiana State University Health Sciences Center, New Orleans, LA 70119, USA
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70119, USA
- Correspondence: (G.Y.); (Z.T.W.); Tel.: +86-791-83813459 (G.Y.); +1-504-9418465 (Z.T.W.)
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Coe KA, Lee W, Stone MC, Komazin-Meredith G, Meredith TC, Grad YH, Walker S. Multi-strain Tn-Seq reveals common daptomycin resistance determinants in Staphylococcus aureus. PLoS Pathog 2019; 15:e1007862. [PMID: 31738809 PMCID: PMC6934316 DOI: 10.1371/journal.ppat.1007862] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/27/2019] [Accepted: 09/24/2019] [Indexed: 01/30/2023] Open
Abstract
Antibiotic-resistant Staphylococcus aureus remains a leading cause of antibiotic resistance-associated mortality in the United States. Given the reality of multi-drug resistant infections, it is imperative that we establish and maintain a pipeline of new compounds to replace or supplement our current antibiotics. A first step towards this goal is to prioritize targets by identifying the genes most consistently required for survival across the S. aureus phylogeny. Here we report the first direct comparison of multiple strains of S. aureus via transposon sequencing. We show that mutant fitness varies by strain in key pathways, underscoring the importance of using more than one strain to differentiate between core and strain-dependent essential genes. We treated the libraries with daptomycin to assess whether the strain-dependent differences impact pathways important for survival. Despite baseline differences in gene importance, several pathways, including the lipoteichoic acid pathway, consistently promote survival under daptomycin exposure, suggesting core vulnerabilities that can be exploited to resensitize daptomycin-nonsusceptible isolates. We also demonstrate the merit of using transposons with outward-facing promoters capable of overexpressing nearby genes for identifying clinically-relevant gain-of-function resistance mechanisms. Together, the daptomycin vulnerabilities and resistance mechanisms support a mode of action with wide-ranging effects on the cell envelope and cell division. This work adds to a growing body of literature demonstrating the nuanced insights gained by comparing Tn-Seq results across multiple bacterial strains. Antibiotic-resistant Staphylococcus aureus kills thousands of people every year in the United States alone. To stay ahead of the looming threat of multidrug-resistant infections, we must continue to develop new antibiotics and find ways to make our current repertoire of antibiotics more effective, including by finding pairs of compounds that perform best when administered together. In the age of next-generation sequencing, we can now use transposon sequencing to find potential targets for new antibiotics on a genome-wide scale, identified as either essential genes or genes that positively influence survival in the presence of an antibiotic. In this work, we created a compendium of genes that are essential across a range of S. aureus strains, as well as those that are important for growth in the presence of the antibiotic daptomycin. The results will be a resource for researchers working to develop the next generation of antibiotic therapies.
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Affiliation(s)
- Kathryn A. Coe
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Wonsik Lee
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Madeleine C. Stone
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gloria Komazin-Meredith
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, Pennsylvania, United States of America
| | - Timothy C. Meredith
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, Pennsylvania, United States of America
- * E-mail: (TCM); (YHG); (SW)
| | - Yonatan H. Grad
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Division of Infectious Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (TCM); (YHG); (SW)
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail: (TCM); (YHG); (SW)
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Guanidine-Containing Polyhydroxyl Macrolides: Chemistry, Biology, and Structure-Activity Relationship. Molecules 2019; 24:molecules24213913. [PMID: 31671653 PMCID: PMC6864768 DOI: 10.3390/molecules24213913] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/26/2019] [Accepted: 10/29/2019] [Indexed: 12/20/2022] Open
Abstract
Antimicrobial resistance has been seriously threatening human health, and discovering new antimicrobial agents from the natural resource is still an important pathway among various strategies to prevent resistance. Guanidine-containing polyhydroxyl macrolides, containing a polyhydroxyl lactone ring and a guanidyl side chain, can be produced by many actinomycetes and have been proved to possess many bioactivities, especially broad-spectrum antibacterial and antifungal activities. To explore the potential of these compounds to be developed into new antimicrobial agents, a review on their structural diversities, spectroscopic characterizations, bioactivities, acute toxicities, antimicrobial mechanisms, and the structure-activity relationship was first performed based on the summaries and analyses of related publications from 1959 to 2019. A total of 63 guanidine-containing polyhydroxyl macrolides were reported, including 46 prototype compounds isolated from 33 marine and terrestrial actinomycetes and 17 structural derivatives. Combining with their antimicrobial mechanisms, structure-activity relationship analyses indicated that the terminal guanidine group and lactone ring of these compounds are vital for their antibacterial and antifungal activities. Further, based on their bioactivities and toxicity analyses, the discovery of guanidyl side-chain targeting to lipoteichoic acid of Staphylococcus aureus indicated that these compounds have a great potency to be developed into antimicrobial and anti-inflammatory drugs.
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Tet38 of Staphylococcus aureus Binds to Host Cell Receptor Complex CD36-Toll-Like Receptor 2 and Protects from Teichoic Acid Synthesis Inhibitors Tunicamycin and Congo Red. Infect Immun 2019; 87:IAI.00194-19. [PMID: 31010815 DOI: 10.1128/iai.00194-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 04/14/2019] [Indexed: 02/06/2023] Open
Abstract
Using an affinity column retention assay, we showed that the purified Tet38 membrane transporter of Staphylococcus aureus bound specifically to host cell CD36 and to the complex CD36-Toll-like receptor 2 (TLR-2), but not to TLR-2 alone or TLR-2 and S. aureus lipoteichoic acid (LTA). We tested the effect of LTA on the internalization of S. aureus tet38 mutant QT7 versus RN6390 by A549 epithelial cells. Addition of anti-LTA antibody to the bacteria prior to adding to A549 cells reduced internalization of QT7 2-fold compared to that with nonspecific antibody treatment. QT7 internalized 4- to 6-fold less than RN6390 with or without anti-LTA antibody. These data suggested that Tet38 and LTA were independently involved in the invasion process. The wall teichoic acid (WTA) inhibitor tunicamycin had an 8-fold decrease in activity with overexpression of tet38 and a 2-fold increase in activity in QT7 (tet38). Reserpine (an inhibitor of efflux pumps) reduced the effect of tet38 overexpression on tunicamycin resistance 4-fold. In addition, tet38 affected growth in the presence of LTA inhibitor Congo red, with overexpression increasing growth and deletion of tet38 reducing growth. In conclusion, Tet38 contributes to S. aureus invasion of A549 via direct binding to CD36 of the complex CD36-TLR-2, and LTA independently bound to TLR-2. The reduction of tunicamycin resistance in the presence of reserpine and the survival ability of the tet38 overexpressor in the presence of Congo red suggest that Tet38 can also protect the synthesis of LTA and WTA in S. aureus against their inhibitors, possibly functioning as an efflux pump.
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Naclerio GA, Karanja CW, Opoku-Temeng C, Sintim HO. Antibacterial Small Molecules That Potently Inhibit Staphylococcus aureus Lipoteichoic Acid Biosynthesis. ChemMedChem 2019; 14:1000-1004. [PMID: 30939229 DOI: 10.1002/cmdc.201900053] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/20/2019] [Indexed: 01/02/2023]
Abstract
The rise of antibiotic resistance, especially in Staphylococcus aureus, and the increasing death rate due to multiresistant bacteria have been well documented. The need for new chemical entities and/or the identification of novel targets for antibacterial drug development is high. Lipoteichoic acid (LTA), a membrane-attached anionic polymer, is important for the growth and virulence of many Gram-positive bacteria, and interest has been high in the discovery of LTA biosynthesis inhibitors. Thus far, only a handful of LTA biosynthesis inhibitors have been described with moderate (MIC=5.34 μg mL-1 ) to low (MIC=1024 μg mL-1 ) activities against S. aureus. Herein we describe the identification of novel compounds that potently inhibit LTA biosynthesis in S. aureus, displaying impressive antibacterial activities (MIC as low as 0.25 μg mL-1 ) against methicillin-resistant S. aureus (MRSA). Under similar in vitro assay conditions, these compounds are 4-fold more potent than vancomycin and 8-fold more potent than linezolid against MRSA.
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Affiliation(s)
- George A Naclerio
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
| | - Caroline W Karanja
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
| | - Clement Opoku-Temeng
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA.,Graduate Program in Biochemistry, University of Maryland, College Park, MD, 20742, USA
| | - Herman O Sintim
- Chemistry Department, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
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Discovery of glycerol phosphate modification on streptococcal rhamnose polysaccharides. Nat Chem Biol 2019; 15:463-471. [PMID: 30936502 PMCID: PMC6470023 DOI: 10.1038/s41589-019-0251-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 02/20/2019] [Indexed: 12/15/2022]
Abstract
Cell wall glycopolymers on the surface of Gram-positive bacteria are fundamental to bacterial physiology and infection biology. Here we identify gacH, a gene in the Streptococcus pyogenes group A carbohydrate (GAC) biosynthetic cluster, in two independent transposon library screens for its ability to confer resistance to zinc and susceptibility to the bactericidal enzyme human group IIA-secreted phospholipase A2. Subsequent structural and phylogenetic analysis of the GacH extracellular domain revealed that GacH represents an alternative class of glycerol phosphate transferase. We detected the presence of glycerol phosphate in the GAC, as well as the serotype c carbohydrate from Streptococcus mutans, which depended on the presence of the respective gacH homologs. Finally, nuclear magnetic resonance analysis of GAC confirmed that glycerol phosphate is attached to approximately 25% of the GAC N-acetylglucosamine side-chains at the C6 hydroxyl group. This previously unrecognized structural modification impacts host-pathogen interaction and has implications for vaccine design.
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Azalomycin F5a, a polyhydroxy macrolide binding to the polar head of phospholipid and targeting to lipoteichoic acid to kill methicillin-resistant Staphylococcus aureus. Biomed Pharmacother 2019; 109:1940-1950. [DOI: 10.1016/j.biopha.2018.11.067] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/13/2018] [Accepted: 11/19/2018] [Indexed: 11/22/2022] Open
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Inactivation of the Monofunctional Peptidoglycan Glycosyltransferase SgtB Allows Staphylococcus aureus To Survive in the Absence of Lipoteichoic Acid. J Bacteriol 2018; 201:JB.00574-18. [PMID: 30322854 PMCID: PMC6287468 DOI: 10.1128/jb.00574-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 10/08/2018] [Indexed: 12/29/2022] Open
Abstract
The bacterial cell wall acts as a primary defense against environmental insults such as changes in osmolarity. It is also a vulnerable structure, as defects in its synthesis can lead to growth arrest or cell death. The important human pathogen Staphylococcus aureus has a typical Gram-positive cell wall, which consists of peptidoglycan and the anionic polymers LTA and wall teichoic acid. Several clinically relevant antibiotics inhibit the synthesis of peptidoglycan; therefore, it and teichoic acids are considered attractive targets for the development of new antimicrobials. We show that LTA is required for efficient peptidoglycan cross-linking in S. aureus and inactivation of a peptidoglycan glycosyltransferase can partially rescue this defect, together revealing an intimate link between peptidoglycan and LTA synthesis. The cell wall of Staphylococcus aureus is composed of peptidoglycan and the anionic polymers lipoteichoic acid (LTA) and wall teichoic acid. LTA is required for growth and normal cell morphology in S. aureus. Strains lacking LTA are usually viable only when grown under osmotically stabilizing conditions or after the acquisition of compensatory mutations. LTA-negative suppressor strains with inactivating mutations in gdpP, which resulted in increased intracellular c-di-AMP levels, were described previously. Here, we sought to identify factors other than c-di-AMP that allow S. aureus to survive without LTA. LTA-negative strains able to grow in unsupplemented medium were obtained and found to contain mutations in sgtB, mazE, clpX, or vraT. The growth improvement through mutations in mazE and sgtB was confirmed by complementation analysis. We also showed that an S. aureussgtB transposon mutant, with the monofunctional peptidoglycan glycosyltransferase SgtB inactivated, displayed a 4-fold increase in the MIC of oxacillin, suggesting that alterations in the peptidoglycan structure could help bacteria compensate for the lack of LTA. Muropeptide analysis of peptidoglycans isolated from a wild-type strain and sgtB mutant strain did not reveal any sizable alterations in the peptidoglycan structure. In contrast, the peptidoglycan isolated from an LTA-negative ltaS mutant strain showed a significant reduction in the fraction of highly cross-linked peptidoglycan, which was partially rescued in the sgtB ltaS double mutant suppressor strain. Taken together, these data point toward an important function of LTA in cell wall integrity through its necessity for proper peptidoglycan assembly. IMPORTANCE The bacterial cell wall acts as a primary defense against environmental insults such as changes in osmolarity. It is also a vulnerable structure, as defects in its synthesis can lead to growth arrest or cell death. The important human pathogen Staphylococcus aureus has a typical Gram-positive cell wall, which consists of peptidoglycan and the anionic polymers LTA and wall teichoic acid. Several clinically relevant antibiotics inhibit the synthesis of peptidoglycan; therefore, it and teichoic acids are considered attractive targets for the development of new antimicrobials. We show that LTA is required for efficient peptidoglycan cross-linking in S. aureus and inactivation of a peptidoglycan glycosyltransferase can partially rescue this defect, together revealing an intimate link between peptidoglycan and LTA synthesis.
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Salt-Induced Stress Stimulates a Lipoteichoic Acid-Specific Three-Component Glycosylation System in Staphylococcus aureus. J Bacteriol 2018; 200:JB.00017-18. [PMID: 29632092 DOI: 10.1128/jb.00017-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/03/2018] [Indexed: 01/01/2023] Open
Abstract
Lipoteichoic acid (LTA) in Staphylococcus aureus is a poly-glycerophosphate polymer anchored to the outer surface of the cell membrane. LTA has numerous roles in cell envelope physiology, including regulating cell autolysis, coordinating cell division, and adapting to environmental growth conditions. LTA is often further modified with substituents, including d-alanine and glycosyl groups, to alter cellular function. While the genetic determinants of d-alanylation have been largely defined, the route of LTA glycosylation and its role in cell envelope physiology have remained unknown, in part due to the low levels of basal LTA glycosylation in S. aureus We demonstrate here that S. aureus utilizes a membrane-associated three-component glycosylation system composed of an undecaprenol (Und) N-acetylglucosamine (GlcNAc) charging enzyme (CsbB; SAOUHSC_00713), a putative flippase to transport loaded substrate to the outside surface of the cell (GtcA; SAOUHSC_02722), and finally an LTA-specific glycosyltransferase that adds α-GlcNAc moieties to LTA (YfhO; SAOUHSC_01213). We demonstrate that this system is specific for LTA with no cross recognition of the structurally similar polyribitol phosphate containing wall teichoic acids. We show that while wild-type S. aureus LTA has only a trace of GlcNAcylated LTA under normal growth conditions, amounts are raised upon either overexpressing CsbB, reducing endogenous d-alanylation activity, expressing the cell envelope stress responsive alternative sigma factor SigB, or by exposure to environmental stress-inducing culture conditions, including growth media containing high levels of sodium chloride.IMPORTANCE The role of glycosylation in the structure and function of Staphylococcus aureus lipoteichoic acid (LTA) is largely unknown. By defining key components of the LTA three-component glycosylation pathway and uncovering stress-induced regulation by the alternative sigma factor SigB, the role of N-acetylglucosamine tailoring during adaptation to environmental stresses can now be elucidated. As the dlt and glycosylation pathways compete for the same sites on LTA and induction of glycosylation results in decreased d-alanylation, the interplay between the two modification systems holds implications for resistance to antibiotics and antimicrobial peptides.
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