1
|
Löckener I, Behrmann LV, Reuter J, Schiefer A, Klöckner A, Krannich S, Otten C, Mölleken K, Ichikawa S, Hoerauf A, Schneider T, Pfarr KM, Henrichfreise B. The MraY Inhibitor Muraymycin D2 and Its Derivatives Induce Enlarged Cells in Obligate Intracellular Chlamydia and Wolbachia and Break the Persistence Phenotype in Chlamydia. Antibiotics (Basel) 2024; 13:421. [PMID: 38786149 PMCID: PMC11117252 DOI: 10.3390/antibiotics13050421] [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: 03/04/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially caused by persisting Chlamydia and long regimens against filarial infections accompanied by low compliance. A new treatment strategy could be the targeting of the reduced peptidoglycan structures involved in cell division in the obligate intracellular bacteria Chlamydia and Wolbachia, the latter being obligate endosymbionts supporting filarial development, growth, and survival. Here, cell culture experiments with C. trachomatis and Wolbachia showed that the nucleoside antibiotics muraymycin and carbacaprazamycin interfere with bacterial cell division and induce enlarged, aberrant cells resembling the penicillin-induced persistence phenotype in Chlamydia. Enzymatic inhibition experiments with purified C. pneumoniae MraY revealed that muraymycin derivatives abolish the synthesis of the peptidoglycan precursor lipid I. Comparative in silico analyses of chlamydial and wolbachial MraY with the corresponding well-characterized enzyme in Aquifex aeolicus revealed a high degree of conservation, providing evidence for a similar mode of inhibition. Muraymycin D2 treatment eradicated persisting non-dividing C. trachomatis cells from an established penicillin-induced persistent infection. This finding indicates that nucleoside antibiotics may have additional properties that can break bacterial persistence.
Collapse
Affiliation(s)
- Iris Löckener
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Lara Vanessa Behrmann
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
| | - Jula Reuter
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Andrea Schiefer
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
| | - Anna Klöckner
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Sebastian Krannich
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Christian Otten
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Katja Mölleken
- Institute for Functional Microbial Genomics, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany;
| | - Satoshi Ichikawa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Kenneth M. Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Beate Henrichfreise
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| |
Collapse
|
2
|
Ersoy SC, Proctor RA, Rose WE, Abdelhady W, Fan SH, Madrigal SL, Elsayed AM, Chambers HF, Sobral RG, Bayer AS. Sensitizing methicillin-resistant Staphylococcus aureus (MRSA) to cefuroxime: the synergic effect of bicarbonate and the wall teichoic acid inhibitor ticlopidine. Antimicrob Agents Chemother 2024; 68:e0162723. [PMID: 38349162 PMCID: PMC10916381 DOI: 10.1128/aac.01627-23] [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: 12/08/2023] [Accepted: 01/18/2024] [Indexed: 03/07/2024] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major challenge for clinicians due, in part, to their resistance to most β-lactams, the first-line treatment for methicillin-susceptible S. aureus. A phenotype termed "NaHCO3-responsiveness" has been identified, wherein many clinical MRSA isolates are rendered susceptible to standard-of-care β-lactams in the presence of physiologically relevant concentrations of NaHCO3, in vitro and ex vivo; moreover, such "NaHCO3-responsive" isolates can be effectively cleared by β-lactams from target tissues in experimental infective endocarditis (IE). One mechanistic impact of NaHCO3 exposure on NaHCO3-responsive MRSA is to repress WTA synthesis. This NaHCO3 effect mimics the phenotype of tarO-deficient MRSA, including sensitization to the PBP2-targeting β-lactam, cefuroxime (CFX). Herein, we further investigated the impacts of NaHCO3 exposure on CFX susceptibility in the presence and absence of a WTA synthesis inhibitor, ticlopidine (TCP), in a collection of clinical MRSA isolates from skin and soft tissue infections (SSTI) and bloodstream infections (BSI). NaHCO3 and/or TCP enhanced susceptibility to CFX in vitro, by both minimum inhibitor concentration (MIC) and time-kill assays, as well as in an ex vivo simulated endocarditis vegetations (SEV) model, in NaHCO3-responsive MRSA. Furthermore, in experimental IE (presumably in the presence of endogenous NaHCO3), pre-exposure to TCP prior to infection sensitized the NaHCO3-responsive MRSA strain (but not the non-responsive strain) to enhanced clearances by CFX in target tissues. These data support the notion that NaHCO3 is acting similarly to WTA synthesis inhibitors, and that such inhibitors have potential translational applications in the treatment of certain MRSA strains in conjunction with specific β-lactam agents.
Collapse
Affiliation(s)
- Selvi C. Ersoy
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Warren E. Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Wessam Abdelhady
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Sook-Ha Fan
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | | | - Ahmed M. Elsayed
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Henry F. Chambers
- University of California-San Francisco School of Medicine, San Francisco, California, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Arnold S. Bayer
- The Lundquist Institute for Biomedical Innovations at Harbor-UCLA Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| |
Collapse
|
3
|
Han J, Zhao X, Zhao X, Li P, Gu Q. Insight into the structure, biosynthesis, isolation method and biological function of teichoic acid in different gram-positive microorganisms: A review. Int J Biol Macromol 2023; 253:126825. [PMID: 37696369 DOI: 10.1016/j.ijbiomac.2023.126825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/13/2023]
Abstract
Teichoic acid (TA) is a weakly anionic polymer present in the cell walls of Gram-positive bacteria. It can be classified into wall teichoic acid (WTA) and lipoteichoic acid (LTA) based on its localization in the cell wall. The structure and biosynthetic pathway of TAs are strain-specific and have a significant role in maintaining cell wall stability. TAs have various beneficial functions, such as immunomodulatory, anticancer and antioxidant activities. However, the purity and yield of TAs are generally not high, and different isolation methods may even affect their structural integrity, which limits the research progress on the probiotic functions of TA. This paper reviews an overview of the structure and biosynthetic pathway of TAs in different strains, as well as the research progress of the isolation and purification methods of TAs. Furthermore, this review also highlights the current research status on the biological functions of TAs. Through a comprehensive understanding of this review, it is expected to pave the way for advancements in isolating and purifying high-quality TAs and, in turn, lay a foundation for contributing to the development of targeted probiotic therapies.
Collapse
Affiliation(s)
- Jiarun Han
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Xin Zhao
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Xilian Zhao
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Ping Li
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Qing Gu
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China.
| |
Collapse
|
4
|
Thoden JB, McKnight JO, Kroft CW, Jast JDT, Holden HM. Structural analysis of a bacterial UDP-sugar 2-epimerase reveals the active site architecture before and after catalysis. J Biol Chem 2023; 299:105200. [PMID: 37660908 PMCID: PMC10622841 DOI: 10.1016/j.jbc.2023.105200] [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: 06/23/2023] [Revised: 08/18/2023] [Accepted: 08/28/2023] [Indexed: 09/05/2023] Open
Abstract
The sugar, 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid, was first identified ∼40 years ago in the O-antigen of Pseudomonas aeruginosa O:3,a,d. Since then, it has been observed on the O-antigens of various pathogenic Gram-negative bacteria including Bordetella pertussis, Escherichia albertii, and Pseudomonas mediterranea. Previous studies have established that five enzymes are required for its biosynthesis beginning with uridine dinucleotide (UDP)-N-acetyl-d-glucosamine (UDP-GlcNAc). The final step in the pathway is catalyzed by a 2-epimerase, which utilizes UDP-2,3-diacetamido-2,3-dideoxy-d-glucuronic acid as its substrate. Curious as to whether this biochemical pathway is found in extreme thermophiles, we examined the published genome sequence for Thermus thermophilus HB27 and identified five ORFs that could possibly encode for the required enzymes. The focus of this investigation is on the ORF WP_011172736, which we demonstrate encodes for a 2-epimerase. For this investigation, ten high resolution X-ray crystallographic structures were determined to resolutions of 2.3 Å or higher. The models have revealed the manner in which the 2-epimerase anchors its UDP-sugar substrate as well as its UDP-sugar product into the active site. In addition, this study reveals for the first time the manner in which any sugar 2-epimerase can simultaneously bind UDP-sugars in both the active site and the allosteric binding region. We have also demonstrated that the T. thermophilus enzyme is allosterically regulated by UDP-GlcNAc. Whereas the sugar 2-epimerases that function on UDP-GlcNAc have been the focus of past biochemical and structural analyses, this is the first detailed investigation of a 2-epimerase that specifically utilizes UDP-2,3-diacetamido-2,3-dideoxy-d-glucuronic acid as its substrate.
Collapse
Affiliation(s)
- James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James O McKnight
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Charles W Kroft
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Joshua D T Jast
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA.
| |
Collapse
|
5
|
Lacey KA, Serpas L, Makita S, Wang Y, Rashidfarrokhi A, Soni C, Gonzalez S, Moreira A, Torres VJ, Reizis B. Secreted mammalian DNases protect against systemic bacterial infection by digesting biofilms. J Exp Med 2023; 220:e20221086. [PMID: 36928522 PMCID: PMC10037111 DOI: 10.1084/jem.20221086] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 01/18/2023] [Accepted: 03/01/2023] [Indexed: 03/18/2023] Open
Abstract
Extracellular DNase DNASE1L3 maintains tolerance to self-DNA in humans and mice, whereas the role of its homolog DNASE1 remains controversial, and the overall function of secreted DNases in immunity is unclear. We report that deletion of murine DNASE1 neither caused autoreactivity in isolation nor exacerbated lupus-like disease in DNASE1L3-deficient mice. However, combined deficiency of DNASE1 and DNASE1L3 rendered mice susceptible to bloodstream infection with Staphylococcus aureus. DNASE1/DNASE1L3 double-deficient mice mounted a normal innate response to S. aureus and did not accumulate neutrophil extracellular traps (NETs). However, their kidneys manifested severe pathology, increased bacterial burden, and biofilm-like bacterial lesions that contained bacterial DNA and excluded neutrophils. Furthermore, systemic administration of recombinant DNASE1 protein during S. aureus infection rescued the mortality of DNase-deficient mice and ameliorated the disease in wild-type mice. Thus, DNASE1 and DNASE1L3 jointly facilitate the control of bacterial infection by digesting extracellular microbial DNA in biofilms, suggesting the original evolutionary function of secreted DNases as antimicrobial agents.
Collapse
Affiliation(s)
- Keenan A. Lacey
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Lee Serpas
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Sohei Makita
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Yueyang Wang
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ali Rashidfarrokhi
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Chetna Soni
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Sandra Gonzalez
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Andre Moreira
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, NY, USA
| | - Boris Reizis
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| |
Collapse
|
6
|
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.
Collapse
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,
| |
Collapse
|
7
|
Qin M, Chen P, Deng B, He R, Wu Y, Yang Y, Deng W, Ding X, Yang F, Xie C, Yang Y, Tian GB. The Emergence of a Multidrug-Resistant and Pathogenic ST42 Lineage of Staphylococcus haemolyticus from a Hospital in China. Microbiol Spectr 2022; 10:e0234221. [PMID: 35579464 PMCID: PMC9241665 DOI: 10.1128/spectrum.02342-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/08/2022] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus haemolyticus is an opportunistic pathogen associated with hospital-acquired infections. However, the genetic diversity of S. haemolyticus among the patients and the hospital environment is largely unknown. Here, we isolated 311 S. haemolyticus strains from different sampling sites of patients and hospital environment. Genomic analysis showed that ST42 is an emerging clone widely disseminated in the hospital. S. haemolyticus ST42 strains exhibited decreased susceptibilities for multiple antibiotics compared with other STs and carried significantly more antibiotic resistance genes (ARGs). Furthermore, ST42 strains harbored more virulence genes per isolate than in other STs, and the capsular biosynthesis genes capDEFG were more prevalent in ST42 strains. Using the Galleria mellonella infection model, we demonstrated that ST42 strains are highly virulent compared with non-ST42 strains. Taken together, our data identified an emerging ST42 clone of S. haemolyticus with aggregated ARGs and virulence determinants in the hospital, representing a significant health threat in terms of both disease and treatment. IMPORTANCES. haemolyticus is an emerging opportunistic pathogen with a high burden of antimicrobial resistance. We performed molecular epidemiological analysis of S. haemolyticus that was isolated from a hospital, and found that the phylogenetic lineages are diverse accompanied by a dominant epidemic clonal lineage ST42. We demonstrated that S. haemolyticus ST42 strains have been disseminated among patients and the hospital environment. The data provide mechanistic insight and indicate that S. haemolyticus ST42 strains are multidrug-resistance and virulent clones via accumulating more ARGs and virulence genes.
Collapse
Affiliation(s)
- Mingyang Qin
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Ping Chen
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Baoguo Deng
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Ruowen He
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Yiping Wu
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Yanxian Yang
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
| | - Wenbin Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, China
| | - Xin Ding
- State Key Laboratory of Oncology in South China, Guangzhou, China
| | - Fan Yang
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Chuanbo Xie
- Cancer Prevention Center, Sun Yat-sen University Cancer Center, Guangzhou, China
- State Key Laboratory of Oncology in South China, Guangzhou, China
- Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Yongqiang Yang
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, China
| | - Guo-Bao Tian
- Department of Microbiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
- Key Laboratory of Tropical Diseases Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
- School of Medicine, Xizang Minzu University, Xianyang, Shaanxi, China
| |
Collapse
|
8
|
Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
Collapse
|
9
|
Abatedaga I, Perez Mora B, Tuttobene M, Müller G, Biancotti D, Borsarelli CD, Valle L, Mussi MA. Characterization of BLUF-photoreceptors present in Acinetobacter nosocomialis. PLoS One 2022; 17:e0254291. [PMID: 35442978 PMCID: PMC9020721 DOI: 10.1371/journal.pone.0254291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 03/01/2022] [Indexed: 11/18/2022] Open
Abstract
Acinetobacter nosocomialis is a Gram-negative opportunistic pathogen, whose ability to cause disease in humans is well recognized. Blue light has been shown to modulate important physiological traits related to persistence and virulence in this microorganism. In this work, we characterized the three Blue Light sensing Using FAD (BLUF) domain-containing proteins encoded in the A. nosocomialis genome, which account for the only canonical light sensors present in this microorganism. By focusing on a light-modulated bacterial process such as motility, the temperature dependence of light regulation was studied, as well as the expression pattern and spectroscopic characteristics of the different A. nosocomialis BLUFs. Our results show that the BLUF-containing proteins AnBLUF65 and AnBLUF46 encode active photoreceptors in the light-regulatory temperature range when expressed recombinantly. In fact, AnBLUF65 is an active photoreceptor in the temperature range from 15°C to 37°C, while AnBLUF46 between 15°C to 32°C, in vitro. In vivo, only the Acinetobacter baumannii BlsA’s ortholog AnBLUF65 was expressed in A. nosocomialis cells recovered from motility plates. Moreover, complementation assays showed that AnBLUF65 is able to mediate light regulation of motility in A. baumannii ΔblsA strain at 30°C, confirming its role as photoreceptor and in modulation of motility by light. Intra-protein interactions analyzed using 3D models built based on A. baumannii´s BlsA photoreceptor, show that hydrophobic/aromatic intra-protein interactions may contribute to the stability of dark/light- adapted states of the studied proteins, reinforcing the previous notion on the importance of these interactions in BLUF photoreceptors. Overall, the results presented here reveal the presence of BLUF photoreceptors in A. nosocomialis with idiosyncratic characteristics respect to the previously characterized A. baumannii’s BlsA, both regarding the photoactivity temperature-dependency as well as expression patterns, contributing thus to broaden our knowledge on the BLUF family.
Collapse
Affiliation(s)
- Inés Abatedaga
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
| | - Bárbara Perez Mora
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Marisel Tuttobene
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Gabriela Müller
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Daiana Biancotti
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
| | - Claudio D. Borsarelli
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
- Instituto de Ciencias Químicas (ICQ), Facultad de Agronomía y Agroindustrias (FAyA), UNSE, Santiago del Estero, Argentina
| | - Lorena Valle
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET), Universidad Nacional de Santiago del Estero (UNSE), Santiago del Estero, Argentina
- Instituto de Ciencias Químicas (ICQ), Facultad de Agronomía y Agroindustrias (FAyA), UNSE, Santiago del Estero, Argentina
- * E-mail: (MAM); (LV)
| | - Maria A. Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario (UNR), Rosario, Argentina
- * E-mail: (MAM); (LV)
| |
Collapse
|
10
|
Chang de Azevedo E, Nascimento AS. The β-lactam ticarcillin is a Staphylococcus aureus UDP-N-acetylglucosamine 2-epimerase binder. Biochimie 2022; 197:1-8. [DOI: 10.1016/j.biochi.2022.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/17/2022] [Accepted: 01/25/2022] [Indexed: 11/27/2022]
|
11
|
Pan T, Guan J, Li Y, Sun B. LcpB Is a Pyrophosphatase Responsible for Wall Teichoic Acid Synthesis and Virulence in Staphylococcus aureus Clinical Isolate ST59. Front Microbiol 2021; 12:788500. [PMID: 34975809 PMCID: PMC8716876 DOI: 10.3389/fmicb.2021.788500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes severe pandemics primarily consisting of skin and soft tissue infections. However, the underlying pathomechanisms of the bacterium are yet to fully understood. The present study identifies LcpB protein, which belongs to the LytR-A-Psr (LCP) family, is crucial for cell wall synthesis and virulence in S. aureus. The findings revealed that LcpB is a pyrophosphatase responsible for wall teichoic acid synthesis. The results also showed that LcpB regulates enzyme activity through specific key arginine sites in its LCP domain. Furthermore, knockout of lcpB in the CA-MRSA isolate ST59 resulted in enhanced hemolytic activity, enlarged of abscesses, and increased leukocyte infiltration. Meanwhile, we also found that LcpB regulates virulence in agr-independent manner and the key sites for pyrophosphatase of LcpB play critical roles in regulating the virulence. In addition, the results showed that the role of LcpB was different between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). This study therefore highlights the dual role of LcpB in cell wall synthesis and regulation of virulence. These insights on the underlying molecular mechanisms can thus guide the development of novel anti-infective strategies.
Collapse
Affiliation(s)
- Ting Pan
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jing Guan
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yujie Li
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| |
Collapse
|
12
|
Lloyd MD, Yevglevskis M, Nathubhai A, James TD, Threadgill MD, Woodman TJ. Racemases and epimerases operating through a 1,1-proton transfer mechanism: reactivity, mechanism and inhibition. Chem Soc Rev 2021; 50:5952-5984. [PMID: 34027955 PMCID: PMC8142540 DOI: 10.1039/d0cs00540a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 12/12/2022]
Abstract
Racemases and epimerases catalyse changes in the stereochemical configurations of chiral centres and are of interest as model enzymes and as biotechnological tools. They also occupy pivotal positions within metabolic pathways and, hence, many of them are important drug targets. This review summarises the catalytic mechanisms of PLP-dependent, enolase family and cofactor-independent racemases and epimerases operating by a deprotonation/reprotonation (1,1-proton transfer) mechanism and methods for measuring their catalytic activity. Strategies for inhibiting these enzymes are reviewed, as are specific examples of inhibitors. Rational design of inhibitors based on substrates has been extensively explored but there is considerable scope for development of transition-state mimics and covalent inhibitors and for the identification of inhibitors by high-throughput, fragment and virtual screening approaches. The increasing availability of enzyme structures obtained using X-ray crystallography will facilitate development of inhibitors by rational design and fragment screening, whilst protein models will facilitate development of transition-state mimics.
Collapse
Affiliation(s)
- Matthew D Lloyd
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| | - Maksims Yevglevskis
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and CatSci Ltd., CBTC2, Capital Business Park, Wentloog, Cardiff CF3 2PX, UK
| | - Amit Nathubhai
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and University of Sunderland, School of Pharmacy & Pharmaceutical Sciences, Sciences Complex, Sunderland SR1 3SD, UK
| | - Tony D James
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK and School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, People's Republic of China
| | - Michael D Threadgill
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK. and Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth SY23 3BY, UK
| | - Timothy J Woodman
- Drug & Target Discovery, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, UK.
| |
Collapse
|
13
|
Hurlburt NK, Guan J, Ong H, Yu H, Chen X, Fisher AJ. Structural characterization of a nonhydrolyzing UDP-GlcNAc 2-epimerase from Neisseria meningitidis serogroup A. Acta Crystallogr F Struct Biol Commun 2020; 76:557-567. [PMID: 33135674 PMCID: PMC7605110 DOI: 10.1107/s2053230x20013680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/13/2020] [Indexed: 11/10/2022] Open
Abstract
Bacterial nonhydrolyzing UDP-N-acetylglucosamine 2-epimerases catalyze the reversible interconversion of UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-N-acetylmannosamine (UDP-ManNAc). UDP-ManNAc is an important intermediate in the biosynthesis of certain cell-surface polysaccharides, including those in some pathogenic bacteria, such as Neisseria meningitidis and Streptococcus pneumoniae. Many of these epimerases are allosterically regulated by UDP-GlcNAc, which binds adjacent to the active site and is required to initiate UDP-ManNAc epimerization. Here, two crystal structures of UDP-N-acetylglucosamine 2-epimerase from Neisseria meningitidis serogroup A (NmSacA) are presented. One crystal structure is of the substrate-free enzyme, while the other structure contains UDP-GlcNAc substrate bound to the active site. Both structures form dimers as seen in similar epimerases, and substrate binding to the active site induces a large conformational change in which two Rossmann-like domains clamp down on the substrate. Unlike other epimerases, NmSacA does not require UDP-GlcNAc to instigate the epimerization of UDP-ManNAc, although UDP-GlcNAc was found to enhance the rate of epimerization. In spite of the conservation of residues involved in binding the allosteric UDP-GlcNAc observed in similar UDP-GlcNAc 2-epimerases, the structures presented here do not contain UDP-GlcNAc bound in the allosteric site. These structural results provide additional insight into the mechanism and regulation of this critical enzyme and improve the structural understanding of the ability of NmSacA to epimerize modified substrates.
Collapse
Affiliation(s)
| | - Jasper Guan
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Hoonsan Ong
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Hai Yu
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Xi Chen
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Andrew J. Fisher
- Department of Chemistry, University of California, Davis, CA 95616, USA
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| |
Collapse
|
14
|
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.
Collapse
|
15
|
de Azevedo EC, Nascimento AS. Energy landscape of the domain movement in Staphylococcus aureus UDP-N-acetylglucosamine 2-epimerase. J Struct Biol 2019; 207:158-168. [PMID: 31088716 DOI: 10.1016/j.jsb.2019.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/18/2019] [Accepted: 05/07/2019] [Indexed: 12/30/2022]
Abstract
Staphylococcus aureus is an important cause of resistant healthcare-associated infections. It has been shown that the wall teichoic acid (WTA) may be an important drug target acting on antibiotic-resistant cells. The UDP-N-acetylglucosamine 2-epimerase, MnaA, is one of the first enzymes on the pathway for the biosynthesis of the WTA. Here, detailed molecular dynamics simulations of S. aureus MnaA were used to characterize the conformational changes that occur in the presence of UDP and UDP-GlcNac and also the energetic landscape associated with these changes. Using different simulation techniques, such as ABMD and GAMD, it was possible to assess the energetic profile for the protein with and without ligands in its active site. We found that there is a dynamic energy landscape that has its minimum changed by the presence of the ligands, with a closed structure of the enzyme being more frequently observed for the bound state while the unbound enzyme favors an opened conformation. Further structural analysis indicated that positively charged amino acids associated with UDP and UDP-GlcNac interactions play a major role in the enzyme opening movement. Finally, the energy landscape profiled in this work provides important conclusions for the design of inhibitor candidates targeting S. aureus MnaA.
Collapse
Affiliation(s)
- Erika Chang de Azevedo
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador SaoCarlense, 400, Parque Arnold Schmidit, São Carlos, SP 13566-590, Brazil
| | - Alessandro S Nascimento
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador SaoCarlense, 400, Parque Arnold Schmidit, São Carlos, SP 13566-590, Brazil.
| |
Collapse
|
16
|
Interplay of Klebsiella pneumoniae fabZ and lpxC Mutations Leads to LpxC Inhibitor-Dependent Growth Resulting from Loss of Membrane Homeostasis. mSphere 2018; 3:3/5/e00508-18. [PMID: 30381354 PMCID: PMC6211225 DOI: 10.1128/msphere.00508-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Emergence of antibiotic resistance has prompted efforts to identify and optimize novel inhibitors of antibacterial targets such as LpxC. This enzyme catalyzes the first committed step of lipid A synthesis, which is necessary to generate lipopolysaccharide and ultimately the Gram-negative protective outer membrane. Investigation of this pathway and its interrelationship with inner membrane (phospholipid) biosynthesis or other pathways is therefore highly important to the fundamental understanding of Gram-negative bacteria and by extension to antibiotic discovery. Here we exploited the availability of a novel LpxC inhibitor to engender the generation of K. pneumoniae resistant mutants whose growth depends on chemical inhibition of LpxC. Inhibitor dependency resulted from the interaction of different resistance mutations and was based on loss of normal cellular mechanisms required to establish membrane homeostasis. This study provides new insights into the importance of this process in K. pneumoniae and how it may be linked to novel biosynthetic pathway inhibitors. Tight coordination of inner and outer membrane biosynthesis is very important in Gram-negative bacteria. Biosynthesis of the lipid A moiety of lipopolysaccharide, which comprises the outer leaflet of the outer membrane has garnered interest for Gram-negative antibacterial discovery. In particular, several potent inhibitors of LpxC (the first committed step of the lipid A pathway) are described. Here we show that serial passaging of Klebsiella pneumoniae in increasing levels of an LpxC inhibitor yielded mutants that grew only in the presence of the inhibitor. These strains had mutations in fabZ and lpxC occurring together (encoding either FabZR121L/LpxCV37G or FabZF51L/LpxCV37G). K. pneumoniae mutants having only LpxCV37G or LpxCV37A or various FabZ mutations alone were less susceptible to the LpxC inhibitor and did not require LpxC inhibition for growth. Western blotting revealed that LpxCV37G accumulated to high levels, and electron microscopy of cells harboring FabZR121L/LpxCV37G indicated an extreme accumulation of membrane in the periplasm when cells were subcultured without LpxC inhibitor. Significant accumulation of detergent-like lipid A pathway intermediates that occur downstream of LpxC (e.g., lipid X and disaccharide monophosphate [DSMP]) was also seen. Taken together, our results suggest that redirection of lipid A pathway substrate by less active FabZ variants, combined with increased activity from LpxCV37G was overdriving the lipid A pathway, necessitating LpxC chemical inhibition, since native cellular maintenance of membrane homeostasis was no longer functioning. IMPORTANCE Emergence of antibiotic resistance has prompted efforts to identify and optimize novel inhibitors of antibacterial targets such as LpxC. This enzyme catalyzes the first committed step of lipid A synthesis, which is necessary to generate lipopolysaccharide and ultimately the Gram-negative protective outer membrane. Investigation of this pathway and its interrelationship with inner membrane (phospholipid) biosynthesis or other pathways is therefore highly important to the fundamental understanding of Gram-negative bacteria and by extension to antibiotic discovery. Here we exploited the availability of a novel LpxC inhibitor to engender the generation of K. pneumoniae resistant mutants whose growth depends on chemical inhibition of LpxC. Inhibitor dependency resulted from the interaction of different resistance mutations and was based on loss of normal cellular mechanisms required to establish membrane homeostasis. This study provides new insights into the importance of this process in K. pneumoniae and how it may be linked to novel biosynthetic pathway inhibitors.
Collapse
|
17
|
Lam AK, Hill MA, Moen EL, Pusavat J, Wouters CL, Rice CV. Cationic Branched Polyethylenimine (BPEI) Disables Antibiotic Resistance in Methicillin-Resistant Staphylococcus epidermidis (MRSE). ChemMedChem 2018; 13:2240-2248. [PMID: 30193012 DOI: 10.1002/cmdc.201800433] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/05/2018] [Indexed: 11/10/2022]
Abstract
Staphylococcus epidermidis is one of the most prevalent prokaryotic species on human skin and mucosal membranes that constitute the commensal flora. S. epidermidis has become one of the most common causes of primary bacteremia. Infections are difficult to diagnose because the pathogen has natural niches on human skin and the ability to adhere to inanimate surfaces via biofilms. Alarmingly, S. epidermidis has acquired resistance to many antibiotics, which presents a danger to human health. Known as methicillin-resistant S. epidermidis (MRSE), most clinical isolates of MRSE in North America exhibit β-lactam resistance primarily due to the presence of mecA, a gene that bestows β-lactam antibiotic resistance in a manner similar to methicillin-resistant Staphylococcus aureus (MRSA). MecA encodes for expression of penicillin-binding protein 2a (PBP2a), which is absent in β-lactam susceptible strains of S. epidermidis. We can disable this resistance factor in MRSE with 600-Da branched polyethylenimine (BPEI). Cationic BPEI targets anionic wall teichoic acid (WTA), an essential cofactor for proper functioning of PBP2a. We found that BPEI synergizes the activity of β-lactam antibiotics against MRSE. Growth curves suggest that the combination of BPEI and oxacillin is bactericidal. Electron micrographs indicate abnormalities in the cellular septa and cell walls of treated samples. Therefore, first-line clinical treatments can be effective against MRSE when used in combination with BPEI.
Collapse
Affiliation(s)
- Anh K Lam
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Melissa A Hill
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Erika L Moen
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Jennifer Pusavat
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Cassandra L Wouters
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Charles V Rice
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| |
Collapse
|
18
|
Analysis of the Tunicamycin Biosynthetic Gene Cluster of Streptomyces chartreusis Reveals New Insights into Tunicamycin Production and Immunity. Antimicrob Agents Chemother 2018; 62:AAC.00130-18. [PMID: 29844049 PMCID: PMC6105854 DOI: 10.1128/aac.00130-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/10/2018] [Indexed: 11/20/2022] Open
Abstract
The tunicamycin biosynthetic gene cluster of Streptomyces chartreusis consists of 14 genes (tunA to tunN) with a high degree of apparent translational coupling. Transcriptional analysis revealed that all of these genes are likely to be transcribed as a single operon from two promoters, tunp1 and tunp2. In-frame deletion analysis revealed that just six of these genes (tunABCDEH) are essential for tunicamycin production in the heterologous host Streptomyces coelicolor, while five (tunFGKLN) with likely counterparts in primary metabolism are not necessary, but presumably ensure efficient production of the antibiotic at the onset of tunicamycin biosynthesis. Three genes are implicated in immunity, namely, tunI and tunJ, which encode a two-component ABC transporter presumably required for export of the antibiotic, and tunM, which encodes a putative S-adenosylmethionine (SAM)-dependent methyltransferase. Expression of tunIJ or tunM in S. coelicolor conferred resistance to exogenous tunicamycin. The results presented here provide new insights into tunicamycin biosynthesis and immunity.
Collapse
|
19
|
Hager FF, López-Guzmán A, Krauter S, Blaukopf M, Polter M, Brockhausen I, Kosma P, Schäffer C. Functional Characterization of Enzymatic Steps Involved in Pyruvylation of Bacterial Secondary Cell Wall Polymer Fragments. Front Microbiol 2018; 9:1356. [PMID: 29997588 PMCID: PMC6030368 DOI: 10.3389/fmicb.2018.01356] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022] Open
Abstract
Various mechanisms of protein cell surface display have evolved during bacterial evolution. Several Gram-positive bacteria employ S-layer homology (SLH) domain-mediated sorting of cell-surface proteins and concomitantly engage a pyruvylated secondary cell-wall polymer as a cell-wall ligand. Specifically, pyruvate ketal linked to β-D-ManNAc is regarded as an indispensable epitope in this cell-surface display mechanism. That secondary cell wall polymer (SCWP) pyruvylation and SLH domain-containing proteins are functionally coupled is supported by the presence of an ortholog of the predicted pyruvyltransferase CsaB in bacterial genomes, such as those of Bacillus anthracis and Paenibacillus alvei. The P. alvei SCWP, consisting of pyruvylated disaccharide repeats [→4)-β-D-GlcNAc-(1→3)-4,6-Pyr-β-D-ManNAc-(1→] serves as a model to investigate the widely unexplored pyruvylation reaction. Here, we reconstituted the underlying enzymatic pathway in vitro in combination with synthesized compounds, used mass spectrometry, and nuclear magnetic resonance spectroscopy for product characterization, and found that CsaB-catalyzed pyruvylation of β-D-ManNAc occurs at the stage of the lipid-linked repeat. We produced the P. alvei TagA (PAV_RS07420) and CsaB (PAV_RS07425) enzymes as recombinant, tagged proteins, and using a synthetic 11-phenoxyundecyl-diphosphoryl-α-GlcNAc acceptor, we uncovered that TagA is an inverting UDP-α-D-ManNAc:GlcNAc-lipid carrier transferase, and that CsaB is a pyruvyltransferase, with synthetic UDP-α-D-ManNAc and phosphoenolpyruvate serving as donor substrates. Next, to substitute for the UDP-α-D-ManNAc substrate, the recombinant UDP-GlcNAc-2-epimerase MnaA (PAV_RS07610) of P. alvei was included in this in vitro reconstitution system. When all three enzymes, their substrates and the lipid-linked GlcNAc primer were combined in a one-pot reaction, a lipid-linked SCWP repeat precursor analog was obtained. This work highlights the biochemical basis of SCWP biosynthesis and bacterial pyruvyl transfer.
Collapse
Affiliation(s)
- Fiona F Hager
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Arturo López-Guzmán
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Simon Krauter
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Markus Blaukopf
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Mathias Polter
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Paul Kosma
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Christina Schäffer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| |
Collapse
|
20
|
Caveney NA, Li FK, Strynadka NC. Enzyme structures of the bacterial peptidoglycan and wall teichoic acid biogenesis pathways. Curr Opin Struct Biol 2018; 53:45-58. [PMID: 29885610 DOI: 10.1016/j.sbi.2018.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/08/2018] [Accepted: 05/16/2018] [Indexed: 01/08/2023]
Abstract
The bacterial cell wall is a complex polymeric structure with essential roles in defence, survival and pathogenesis. Common to both Gram-positive and Gram-negative bacteria is the mesh-like peptidoglycan sacculus that surrounds the outer leaflet of the cytoplasmic membrane. Recent crystallographic studies of enzymes that comprise the peptidoglycan biosynthetic pathway have led to significant new understanding of all stages. These include initial multi-step cytosolic formation of sugar-pentapeptide precursors, transfer of the precursors to activated polyprenyl lipids at the membrane inner leaflet and flippase mediated relocalization of the resulting lipid II precursors to the outer leaflet where glycopolymerization and subsequent peptide crosslinking are finalized. Additional, species-specific enzymes allow customized peptidoglycan modifications and biosynthetic regulation that are important to bacterial virulence and survival. These studies have reinforced the unique and specific catalytic mechanisms at play in cell wall biogenesis and expanded the atomic foundation to develop novel, structure guided, antibacterial agents.
Collapse
Affiliation(s)
- Nathanael A Caveney
- University of British Columbia, Biochemistry and Molecular Biology and the Center for Blood Research, Rm 4350 Life Sciences Center, 2350 Health Sciences Mall, Vancouver V6T 1Z3 Canada
| | - Franco Kk Li
- University of British Columbia, Biochemistry and Molecular Biology and the Center for Blood Research, Rm 4350 Life Sciences Center, 2350 Health Sciences Mall, Vancouver V6T 1Z3 Canada
| | - Natalie Cj Strynadka
- University of British Columbia, Biochemistry and Molecular Biology and the Center for Blood Research, Rm 4350 Life Sciences Center, 2350 Health Sciences Mall, Vancouver V6T 1Z3 Canada.
| |
Collapse
|
21
|
Walker SS, Labroli M, Painter RE, Wiltsie J, Sherborne B, Murgolo N, Sher X, Mann P, Zuck P, Garlisi CG, Su J, Kargman S, Xiao L, Scapin G, Salowe S, Devito K, Sheth P, Buist N, Tan CM, Black TA, Roemer T. Antibacterial small molecules targeting the conserved TOPRIM domain of DNA gyrase. PLoS One 2017; 12:e0180965. [PMID: 28700746 PMCID: PMC5507300 DOI: 10.1371/journal.pone.0180965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/23/2017] [Indexed: 12/21/2022] Open
Abstract
To combat the threat of antibiotic-resistant Gram-negative bacteria, novel agents that circumvent established resistance mechanisms are urgently needed. Our approach was to focus first on identifying bioactive small molecules followed by chemical lead prioritization and target identification. Within this annotated library of bioactives, we identified a small molecule with activity against efflux-deficient Escherichia coli and other sensitized Gram-negatives. Further studies suggested that this compound inhibited DNA replication and selection for resistance identified mutations in a subunit of E. coli DNA gyrase, a type II topoisomerase. Our initial compound demonstrated weak inhibition of DNA gyrase activity while optimized compounds demonstrated significantly improved inhibition of E. coli and Pseudomonas aeruginosa DNA gyrase and caused cleaved complex stabilization, a hallmark of certain bactericidal DNA gyrase inhibitors. Amino acid substitutions conferring resistance to this new class of DNA gyrase inhibitors reside exclusively in the TOPRIM domain of GyrB and are not associated with resistance to the fluoroquinolones, suggesting a novel binding site for a gyrase inhibitor.
Collapse
Affiliation(s)
- Scott S. Walker
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
- * E-mail:
| | - Marc Labroli
- Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | | | - Judyann Wiltsie
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Brad Sherborne
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Nicholas Murgolo
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Xinwei Sher
- Merck & Co., Inc., Boston, Massachusetts, United States of America
| | - Paul Mann
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Paul Zuck
- Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | | | - Jing Su
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Stacia Kargman
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Li Xiao
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Giovanna Scapin
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Scott Salowe
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Kristine Devito
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Payal Sheth
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Nichole Buist
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | | | - Todd A. Black
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| | - Terry Roemer
- Merck & Co., Inc., Kenilworth, New Jersey, United States of America
| |
Collapse
|
22
|
Dual-Targeting Small-Molecule Inhibitors of the Staphylococcus aureus FMN Riboswitch Disrupt Riboflavin Homeostasis in an Infectious Setting. Cell Chem Biol 2017; 24:576-588.e6. [PMID: 28434876 DOI: 10.1016/j.chembiol.2017.03.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/03/2017] [Accepted: 03/23/2017] [Indexed: 11/22/2022]
Abstract
Riboswitches are bacterial-specific, broadly conserved, non-coding RNA structural elements that control gene expression of numerous metabolic pathways and transport functions essential for cell growth. As such, riboswitch inhibitors represent a new class of potential antibacterial agents. Recently, we identified ribocil-C, a highly selective inhibitor of the flavin mononucleotide (FMN) riboswitch that controls expression of de novo riboflavin (RF, vitamin B2) biosynthesis in Escherichia coli. Here, we provide a mechanistic characterization of the antibacterial effects of ribocil-C as well as of roseoflavin (RoF), an antimetabolite analog of RF, among medically significant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis. We provide genetic, biophysical, computational, biochemical, and pharmacological evidence that ribocil-C and RoF specifically inhibit dual FMN riboswitches, separately controlling RF biosynthesis and uptake processes essential for MRSA growth and pathogenesis. Such a dual-targeting mechanism is specifically required to develop broad-spectrum Gram-positive antibacterial agents targeting RF metabolism.
Collapse
|
23
|
Mandal M, Tan Z, Madsen-Duggan C, Buevich AV, Caldwell JP, Dejesus R, Flattery A, Garlisi CG, Gill C, Ha SN, Ho G, Koseoglu S, Labroli M, Basu K, Lee SH, Liang L, Liu J, Mayhood T, McGuinness D, McLaren DG, Wen X, Parmee E, Rindgen D, Roemer T, Sheth P, Tawa P, Tata J, Yang C, Yang SW, Xiao L, Wang H, Tan C, Tang H, Walsh P, Walsh E, Wu J, Su J. Can We Make Small Molecules Lean? Optimization of a Highly Lipophilic TarO Inhibitor. J Med Chem 2017; 60:3851-3865. [DOI: 10.1021/acs.jmedchem.7b00113] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mihirbaran Mandal
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Zheng Tan
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Christina Madsen-Duggan
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Alexei V. Buevich
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - John P. Caldwell
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Reynalda Dejesus
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Amy Flattery
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Charles G. Garlisi
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Charles Gill
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Sookhee Nicole Ha
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Ginny Ho
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Sandra Koseoglu
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Marc Labroli
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Kallol Basu
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Sang Ho Lee
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Lianzhu Liang
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Jenny Liu
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Todd Mayhood
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Debra McGuinness
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - David G. McLaren
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Xiujuan Wen
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Emma Parmee
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Diane Rindgen
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Terry Roemer
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Payal Sheth
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Paul Tawa
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - James Tata
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Christine Yang
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Shu-Wei Yang
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Li Xiao
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Hao Wang
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Christopher Tan
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Haifeng Tang
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Paul Walsh
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Erika Walsh
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Jin Wu
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Jing Su
- Global Chemistry, ‡Early Discovery Bacteriology, §Discovery Pharmaceutical Sciences, ∥Pharmacokinetics, Pharmacodynamics, and Drug Metabolism, ⊥In Vivo Pharmacology, and #In Vitro Pharmacology, MRL, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| |
Collapse
|
24
|
Mashruwala AA, Guchte AVD, Boyd JM. Impaired respiration elicits SrrAB-dependent programmed cell lysis and biofilm formation in Staphylococcus aureus. eLife 2017; 6. [PMID: 28221135 PMCID: PMC5380435 DOI: 10.7554/elife.23845] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 02/20/2017] [Indexed: 01/25/2023] Open
Abstract
Biofilms are communities of microorganisms attached to a surface or each other. Biofilm-associated cells are the etiologic agents of recurrent Staphylococcus aureus infections. Infected human tissues are hypoxic or anoxic. S. aureus increases biofilm formation in response to hypoxia, but how this occurs is unknown. In the current study we report that oxygen influences biofilm formation in its capacity as a terminal electron acceptor for cellular respiration. Genetic, physiological, or chemical inhibition of respiratory processes elicited increased biofilm formation. Impaired respiration led to increased cell lysis via divergent regulation of two processes: increased expression of the AtlA murein hydrolase and decreased expression of wall-teichoic acids. The AltA-dependent release of cytosolic DNA contributed to increased biofilm formation. Further, cell lysis and biofilm formation were governed by the SrrAB two-component regulatory system. Data presented support a model wherein SrrAB-dependent biofilm formation occurs in response to the accumulation of reduced menaquinone. DOI:http://dx.doi.org/10.7554/eLife.23845.001 Millions of bacteria live on the human body. Generally these bacteria co-exist with us peacefully, but sometimes certain bacteria may enter the body and cause infections, such as gum disease or a bone infection called osteomyelitis. Many of these infections are thought to occur when the bacteria become able to form complex communities called biofilms. Bacteria living in a biofilm cooperate and make lifestyle choices as a community, so in this way, they behave like a single organism containing many cells. A sticky glue-like material called the matrix holds the bacteria in a biofilm together. This matrix protects the bacteria in the biofilm from both the human immune system and antibiotics, allowing infections to develop and making them difficult to treat. Previous research has shown that the supply and level of oxygen in infected tissues decreases as an infection gets worse. One bacterium that typically lives peacefully on our bodies, called Staphylococcus aureus, can sometimes cause serious biofilm-associated infections. S. aureus forms biofilms more readily when oxygen is in short supply, but it was not known how these biofilms form. Understanding how S. aureus forms biofilms could help scientists develop better treatments for bacterial infections. Most bacterial cells have a cell wall to provide them with structural support. Mashruwala et al. found that, when oxygen levels are low, S. aureus decreases the production of a type of sugar that makes up the cell wall. At the same time, the bacteria produce more of an enzyme that breaks down cell walls. Together, these processes cause some of the bacteria cells to break open. The contents of these broken cells, including their DNA, help form the matrix that will hold together and protect the other bacterial cells in the biofilm. The experiments also identified a protein called SrrAB that switches on the process that ruptures the cells when oxygen is low. The findings of Mashruwala et al. show how bacteria grown in the laboratory form biofilms when they are starved of oxygen. The next steps following on from this work are to find out whether the same thing happens when bacteria infect animals and whether drugs that block the rupturing of bacterial cells could be used to treat infections. DOI:http://dx.doi.org/10.7554/eLife.23845.002
Collapse
Affiliation(s)
- Ameya A Mashruwala
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Adriana van de Guchte
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| | - Jeffrey M Boyd
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, United States
| |
Collapse
|
25
|
Müller I. Guidelines for the successful generation of protein-ligand complex crystals. Acta Crystallogr D Struct Biol 2017; 73:79-92. [PMID: 28177304 PMCID: PMC5297911 DOI: 10.1107/s2059798316020271] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 12/21/2016] [Indexed: 11/23/2022] Open
Abstract
With continuous technical improvements at synchrotron facilities, data-collection rates have increased dramatically. This makes it possible to collect diffraction data for hundreds of protein-ligand complexes within a day, provided that a suitable crystal system is at hand. However, developing a suitable crystal system can prove challenging, exceeding the timescale of data collection by several orders of magnitude. Firstly, a useful crystallization construct of the protein of interest needs to be chosen and its expression and purification optimized, before screening for suitable crystallization and soaking conditions can start. This article reviews recent publications analysing large data sets of crystallization trials, with the aim of identifying factors that do or do not make a good crystallization construct, and gives guidance in the design of an expression construct. It provides an overview of common protein-expression systems, addresses how ligand binding can be both help and hindrance for protein purification, and describes ligand co-crystallization and soaking, with an emphasis on troubleshooting.
Collapse
Affiliation(s)
- Ilka Müller
- Structural Biology, Discovery from Charles River, Chesterford Research Park, Saffron Walden CB10 1XL, England
| |
Collapse
|
26
|
Wanner S, Schade J, Keinhörster D, Weller N, George SE, Kull L, Bauer J, Grau T, Winstel V, Stoy H, Kretschmer D, Kolata J, Wolz C, Bröker BM, Weidenmaier C. Wall teichoic acids mediate increased virulence in Staphylococcus aureus. Nat Microbiol 2017; 2:16257. [DOI: 10.1038/nmicrobiol.2016.257] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/28/2016] [Indexed: 12/15/2022]
|
27
|
Antibacterial New Target Discovery: Sentinel Examples, Strategies, and Surveying Success. TOPICS IN MEDICINAL CHEMISTRY 2017. [DOI: 10.1007/7355_2016_31] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
28
|
Yang SW, Pan J, Yang C, Labroli M, Pan W, Caldwell J, Ha S, Koseoglu S, Xiao JC, Mayhood T, Sheth PR, Garlisi CG, Wu J, Lee SH, Wang H, Tan CM, Roemer T, Su J. Benzimidazole analogs as WTA biosynthesis inhibitors targeting methicillin resistant Staphylococcus aureus. Bioorg Med Chem Lett 2016; 26:4743-4747. [DOI: 10.1016/j.bmcl.2016.08.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
|
29
|
Multidrug Intrinsic Resistance Factors in Staphylococcus aureus Identified by Profiling Fitness within High-Diversity Transposon Libraries. mBio 2016; 7:mBio.00950-16. [PMID: 27531908 PMCID: PMC4992970 DOI: 10.1128/mbio.00950-16] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Staphylococcus aureus is a leading cause of life-threatening infections worldwide. The MIC of an antibiotic against S. aureus, as well as other microbes, is determined by the affinity of the antibiotic for its target in addition to a complex interplay of many other cellular factors. Identifying nontarget factors impacting resistance to multiple antibiotics could inform the design of new compounds and lead to more-effective antimicrobial strategies. We examined large collections of transposon insertion mutants in S. aureus using transposon sequencing (Tn-Seq) to detect transposon mutants with reduced fitness in the presence of six clinically important antibiotics—ciprofloxacin, daptomycin, gentamicin, linezolid, oxacillin, and vancomycin. This approach allowed us to assess the relative fitness of many mutants simultaneously within these libraries. We identified pathways/genes previously known to be involved in resistance to individual antibiotics, including graRS and vraFG (graRS/vraFG), mprF, and fmtA, validating the approach, and found several to be important across multiple classes of antibiotics. We also identified two new, previously uncharacterized genes, SAOUHSC_01025 and SAOUHSC_01050, encoding polytopic membrane proteins, as important in limiting the effectiveness of multiple antibiotics. Machine learning identified similarities in the fitness profiles of graXRS/vraFG, SAOUHSC_01025, and SAOUHSC_01050 mutants upon antibiotic treatment, connecting these genes of unknown function to modulation of crucial cell envelope properties. Therapeutic strategies that combine a known antibiotic with a compound that targets these or other intrinsic resistance factors may be of value for enhancing the activity of existing antibiotics for treating otherwise-resistant S. aureus strains. Bacterial resistance to every major class of antibiotics has emerged, and we are entering a “post-antibiotic era” where relatively minor infections can lead to serious complications or even death. The utility of an antibiotic for a specific pathogen is limited by both intrinsic and acquired factors. Identifying the repertoire of intrinsic resistance factors of an antibiotic for Staphylococcus aureus, a leading cause of community- and hospital-acquired infections, would inform the design of new drugs as well as the identification of compounds that enhance the activity of existing drugs. To identify factors that limit the activity of antibiotics against S. aureus, we used Tn-Seq to simultaneously assess fitness of transposon mutants in every nonessential gene in the presence of six clinically important antibiotics. This work provides an efficient approach for identifying promising targets for drugs that can enhance susceptibility or restore sensitivity to existing antibiotics.
Collapse
|
30
|
Labroli MA, Caldwell JP, Yang C, Lee SH, Wang H, Koseoglu S, Mann P, Yang SW, Xiao J, Garlisi CG, Tan C, Roemer T, Su J. Discovery of potent wall teichoic acid early stage inhibitors. Bioorg Med Chem Lett 2016; 26:3999-4002. [DOI: 10.1016/j.bmcl.2016.06.090] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/28/2016] [Accepted: 06/29/2016] [Indexed: 10/21/2022]
|