1
|
Ayala JC, Balthazar JT, Shafer WM. Transcriptional responses of Neisseria gonorrhoeae to glucose and lactate: implications for resistance to oxidative damage and biofilm formation. mBio 2024:e0176124. [PMID: 39012148 DOI: 10.1128/mbio.01761-24] [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: 06/11/2024] [Accepted: 06/26/2024] [Indexed: 07/17/2024] Open
Abstract
Understanding how bacteria adapt to different environmental conditions is crucial for advancing knowledge regarding pathogenic mechanisms that operate during infection as well as efforts to develop new therapeutic strategies to cure or prevent infections. Here, we investigated the transcriptional response of Neisseria gonorrhoeae, the causative agent of gonorrhea, to L-lactate and glucose, two important carbon sources found in the host environment. Our study revealed extensive transcriptional changes that gonococci make in response to L-lactate, with 37% of the gonococcal transcriptome being regulated, compared to only 9% by glucose. We found that L-lactate induces a transcriptional program that would negatively impact iron transport, potentially limiting the availability of labile iron, which would be important in the face of the multiple hydrogen peroxide attacks encountered by gonococci during its lifecycle. Furthermore, we found that L-lactate-mediated transcriptional response promoted aerobic respiration and dispersal of biofilms, contrasting with an anaerobic condition previously reported to favor biofilm formation. Our findings suggest an intricate interplay between carbon metabolism, iron homeostasis, biofilm formation, and stress response in N. gonorrhoeae, providing insights into its pathogenesis and identifying potential therapeutic targets.IMPORTANCEGonorrhea is a prevalent sexually transmitted infection caused by the human pathogen Neisseria gonorrhoeae, with ca. 82 million cases reported worldwide annually. The rise of antibiotic resistance in N. gonorrhoeae poses a significant public health threat, highlighting the urgent need for alternative treatment strategies. By elucidating how N. gonorrhoeae responds to host-derived carbon sources such as L-lactate and glucose, this study offers insights into the metabolic adaptations crucial for bacterial survival and virulence during infection. Understanding these adaptations provides a foundation for developing novel therapeutic approaches targeting bacterial metabolism, iron homeostasis, and virulence gene expression. Moreover, the findings reported herein regarding biofilm formation and L-lactate transport and metabolism contribute to our understanding of N. gonorrhoeae pathogenesis, offering potential avenues for preventing and treating gonorrhea infections.
Collapse
Affiliation(s)
- Julio C Ayala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Division of STD Prevention, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jacqueline T Balthazar
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center, Decatur, Georgia, USA
| |
Collapse
|
2
|
Laborda P, Molin S, Johansen HK, Martínez JL, Hernando-Amado S. Role of bacterial multidrug efflux pumps during infection. World J Microbiol Biotechnol 2024; 40:226. [PMID: 38822187 DOI: 10.1007/s11274-024-04042-7] [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: 04/03/2024] [Accepted: 05/29/2024] [Indexed: 06/02/2024]
Abstract
Multidrug efflux pumps are protein complexes located in the cell envelope that enable bacteria to expel, not only antibiotics, but also a wide array of molecules relevant for infection. Hence, they are important players in microbial pathogenesis. On the one hand, efflux pumps can extrude exogenous compounds, including host-produced antimicrobial molecules. Through this extrusion, pathogens can resist antimicrobial agents and evade host defenses. On the other hand, efflux pumps also have a role in the extrusion of endogenous compounds, such as bacterial intercommunication signaling molecules, virulence factors or metabolites. Therefore, efflux pumps are involved in the modulation of bacterial behavior and virulence, as well as in the maintenance of the bacterial homeostasis under different stresses found within the host. This review delves into the multifaceted roles that efflux pumps have, shedding light on their impact on bacterial virulence and their contribution to bacterial infection. These observations suggest that strategies targeting bacterial efflux pumps could both reinvigorate the efficacy of existing antibiotics and modulate the bacterial pathogenicity to the host. Thus, a comprehensive understanding of bacterial efflux pumps can be pivotal for the development of new effective strategies for the management of infectious diseases.
Collapse
Affiliation(s)
- Pablo Laborda
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, 9301, Denmark.
| | - Søren Molin
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, 9301, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | |
Collapse
|
3
|
Fan C, Dai W, Zhang H, Liu S, Lin Z, Xue Q. Genomic and Proteomic Analyses of Extracellular Products Reveal Major Virulence Factors Likely Accounting for Differences in Pathogenicity to Bivalves between Vibrio mediterranei Strains. Animals (Basel) 2024; 14:692. [PMID: 38473077 DOI: 10.3390/ani14050692] [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: 11/30/2023] [Revised: 02/07/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Vibrio mediterranei, a bacterial pathogen of bivalves, has exhibited strain-dependent virulence. The mechanisms behind the variations in bivalve pathogenicity between V. mediterranei strains have remained unclear. However, a preliminary analysis of the extracellular product (ECP) proteomes has revealed differences in protein compositions between low- and high-virulence strains; in addition to 1265 shared proteins, 127 proteins have been identified to be specific to one low-virulence strain and 95 proteins to be specific to two high-virulence strains. We further studied the ECP proteins of the three V. mediterranei strains from functional perspectives using integrated genomics and proteomics approaches. The results showed that lipid metabolism, transporter activity and membrane transporter pathways were more enriched in the ECPs of the two high-virulence strains than in those of the low-virulence strain. Additionally, 73 of the 95 high-virulence strain-specific proteins were found to have coding genes in the genome but were not expressed in the low-virulence strain. Moreover, comparisons with known virulence factors in the Virulence Factor Database (VFDB) and the Pathogen-Host Interactions Database (PHI-base) allowed us to predict more than 10 virulence factors in the categories of antimicrobial activity/competitive advantage, the effector delivery system and immune modulation, and the high-virulence strain-specific ECP proteins consisted of a greater percentage of known virulence factors than the low-virulence strain. Particularly, two virulence factors, MtrC and KatG, were identified in the ECPs of the two high-virulence strains but not in those of the low-virulence strain. Most coding genes of the ECP proteins including known virulence factors were identified on chromosome 1 of V. mediterranei. Our findings indicate that variations in virulence factor composition in the bacterial ECPs may partially account for the differences in the bivalve pathogenicity between V. mediterranei strains.
Collapse
Affiliation(s)
- Congling Fan
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
| | - Wenfang Dai
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ninghai, Ningbo 315604, China
| | - Haiyan Zhang
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ninghai, Ningbo 315604, China
| | - Sheng Liu
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ninghai, Ningbo 315604, China
| | - Zhihua Lin
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ninghai, Ningbo 315604, China
| | - Qinggang Xue
- Zhejiang Key Laboratory of Aquatic Germplasm Resource, College of Biological Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, China
- Ninghai Institute of Mariculture Breeding and Seed Industry, Zhejiang Wanli University, Ninghai, Ningbo 315604, China
| |
Collapse
|
4
|
Hooks GM, Ayala JC, Holley CL, Dhulipala V, Beggs GA, Perfect JR, Schumacher MA, Shafer WM, Brennan RG. Hormonal steroids induce multidrug resistance and stress response genes in Neisseria gonorrhoeae by binding to MtrR. Nat Commun 2024; 15:1153. [PMID: 38326294 PMCID: PMC10850145 DOI: 10.1038/s41467-024-45195-1] [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: 08/30/2023] [Accepted: 01/16/2024] [Indexed: 02/09/2024] Open
Abstract
Transcriptional regulator MtrR inhibits the expression of the multidrug efflux pump operon mtrCDE in the pathogenic bacterium Neisseria gonorrhoeae. Here, we show that MtrR binds the hormonal steroids progesterone, β-estradiol, and testosterone, which are present at urogenital infection sites, as well as ethinyl estrogen, a component of some hormonal contraceptives. Steroid binding leads to the decreased affinity of MtrR for cognate DNA, increased mtrCDE expression, and enhanced antimicrobial resistance. Furthermore, we solve crystal structures of MtrR bound to each steroid, thus revealing their binding mechanisms and the conformational changes that induce MtrR.
Collapse
Affiliation(s)
- Grace M Hooks
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Julio C Ayala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- STD Laboratory Reference and Research Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Concerta L Holley
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | - Vijaya Dhulipala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
| | - Grace A Beggs
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - John R Perfect
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
- Laboratories of Microbial Pathogenesis, VA Medical Research Service, Veterans Affairs Medical Center, Decatur, GA, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA.
| |
Collapse
|
5
|
Zhu M, Frank MW, Radka CD, Jeanfavre S, Tse MW, Pacheco JA, Pierce K, Deik A, Xu J, Hussain S, Hussain FA, Xulu N, Khan N, Pillay V, Dong KL, Ndung’u T, Clish CB, Rock CO, Blainey PC, Bloom SM, Kwon DS. Vaginal Lactobacillus fatty acid response mechanisms reveal a novel strategy for bacterial vaginosis treatment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.30.573720. [PMID: 38234804 PMCID: PMC10793477 DOI: 10.1101/2023.12.30.573720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Bacterial vaginosis (BV), a common syndrome characterized by Lactobacillus-deficient vaginal microbiota, is associated with adverse health outcomes. BV often recurs after standard antibiotic therapy in part because antibiotics promote microbiota dominance by Lactobacillus iners instead of Lactobacillus crispatus, which has more beneficial health associations. Strategies to promote L. crispatus and inhibit L. iners are thus needed. We show that oleic acid (OA) and similar long-chain fatty acids simultaneously inhibit L. iners and enhance L. crispatus growth. These phenotypes require OA-inducible genes conserved in L. crispatus and related species, including an oleate hydratase (ohyA) and putative fatty acid efflux pump (farE). FarE mediates OA resistance, while OhyA is robustly active in the human vaginal microbiota and sequesters OA in a derivative form that only ohyA-harboring organisms can exploit. Finally, OA promotes L. crispatus dominance more effectively than antibiotics in an in vitro model of BV, suggesting a novel approach for treatment.
Collapse
Affiliation(s)
- Meilin Zhu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Matthew W. Frank
- Department of Host-Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Christopher D. Radka
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky
| | | | - Megan W. Tse
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Kerry Pierce
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Amy Deik
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jiawu Xu
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Salina Hussain
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
| | - Fatima Aysha Hussain
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Nondumiso Xulu
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | - Nasreen Khan
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
| | | | - Krista L. Dong
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Health Systems Trust, Durban, South Africa
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Thumbi Ndung’u
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- HIV Pathogenesis Programme (HPP), The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa
- Africa Health Research Institute (AHRI), Durban, South Africa
- Max Planck Institute for Infection Biology, Berlin, Germany
- Division of Infection and Immunity, University College London, London, UK
| | | | - Charles O. Rock
- Department of Host-Microbe Interactions, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
- passed away on September 22, 2023
| | - Paul C. Blainey
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Seth M. Bloom
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Douglas S. Kwon
- Ragon Institute of MGH, MIT and Harvard, Cambridge, MA, USA
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| |
Collapse
|
6
|
Gray MC, Thomas KS, Lamb ER, Werner LM, Connolly KL, Jerse AE, Criss AK. Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine. Infect Immun 2023; 91:e0030923. [PMID: 37991382 PMCID: PMC10715150 DOI: 10.1128/iai.00309-23] [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: 08/07/2023] [Accepted: 09/27/2023] [Indexed: 11/23/2023] Open
Abstract
The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as four-component meningococcal B vaccine (4CMenB) are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here, we present the development and optimization of assays to evaluate antibody functionality after immunization of mice: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils [polymorphonuclear leukocytes (PMNs)]. These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical studies and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae.
Collapse
Affiliation(s)
- Mary C. Gray
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Keena S. Thomas
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Evan R. Lamb
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Lacie M. Werner
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Kristie L. Connolly
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
| | - Ann E. Jerse
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, Maryland, USA
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| |
Collapse
|
7
|
Gray MC, Thomas KS, Lamb ER, Werner LM, Connolly KL, Jerse AE, Criss AK. Evaluating vaccine-elicited antibody activities against Neisseria gonorrhoeae: cross-protective responses elicited by the 4CMenB meningococcal vaccine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.03.551882. [PMID: 37577557 PMCID: PMC10418180 DOI: 10.1101/2023.08.03.551882] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The bacterial pathogen Neisseria gonorrhoeae is an urgent global health problem due to increasing numbers of infections, coupled with rampant antibiotic resistance. Vaccines against gonorrhea are being prioritized to combat drug-resistant N. gonorrhoeae. Meningococcal serogroup B vaccines such as 4CMenB are predicted by epidemiology studies to cross-protect individuals from natural infection with N. gonorrhoeae and elicit antibodies that cross-react with N. gonorrhoeae. Evaluation of vaccine candidates for gonorrhea requires a suite of assays for predicting efficacy in vitro and in animal models of infection, including the role of antibodies elicited by immunization. Here we present assays to evaluate antibody functionality after immunization: antibody binding to intact N. gonorrhoeae, serum bactericidal activity, and opsonophagocytic killing activity using primary human neutrophils (polymorphonuclear leukocytes). These assays were developed with purified antibodies against N. gonorrhoeae and used to evaluate serum from mice that were vaccinated with 4CMenB or given alum as a negative control. Results from these assays will help prioritize gonorrhea vaccine candidates for advanced preclinical to early clinical study and will contribute to identifying correlates and mechanisms of immune protection against N. gonorrhoeae .
Collapse
|
8
|
Waltmann A, Balthazar JT, Begum AA, Hua N, Jerse AE, Shafer WM, Hobbs MM, Duncan JA. Neisseria gonorrhoeae MtrCDE Efflux Pump During In Vivo Experimental Genital Tract Infection in Men and Mice Reveals the Presence of Within-Host Colonization Bottleneck. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.06.23.23291824. [PMID: 37425726 PMCID: PMC10327229 DOI: 10.1101/2023.06.23.23291824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The MtrCDE efflux pump of Neisseria gonorrhoeae exports a wide range of antimicrobial compounds that the gonococcus encounters at mucosal surfaces during colonization and infection. Here, we evaluate the role of this efflux pump system in strain FA1090 in human male urethral infection with a Controlled Human Infection Model. Using the strategy of competitive multi-strain infection with wild-type FA1090 and an isogenic mutant strain that does not contain a functional MtrCDE pump, we found that the presence of the efflux pump during human experimental infection did not confer a competitive advantage. This finding is in contrast to previous findings in female mice, which demonstrated that gonococci of strain FA19 lacking a functional MtrCDE pump had a significantly reduced fitness compared to the wild type strain in the lower genital tract of female mice. We conducted competitive infections in female mice with FA19 and FA1090 strains, including mutants that do not assemble a functional Mtr efflux pump, demonstrating the fitness advantage provided byt the MtrCDE efflux pump during infection of mice is strain dependent. Our data indicate that new gonorrhea treatment strategies targeting the MtrCDE efflux pump functions may not be universally efficacious in naturally occurring infections. Owing to the equal fitness of FA1090 strains in men, our experiments unexpectedly demonstrated the likely presence of an early colonization bottleneck of N. gonorrhoeae in the human male urethra. TRIAL REGISTRATION Clinicaltrials.gov NCT03840811 .
Collapse
|
9
|
Hooks GM, Ayala JC, Beggs GA, Perfect JR, Schumacher MA, Shafer WM, Brennan RG. Hormonal steroids bind the Neisseria gonorrhoeae multidrug resistance regulator, MtrR, to induce a multidrug binding efflux pump and stress-response sigma factor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.13.544409. [PMID: 37398116 PMCID: PMC10312642 DOI: 10.1101/2023.06.13.544409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Overexpression of the multidrug efflux pump MtrCDE, a critical factor of multidrug-resistance in Neisseria gonorrhoeae , the causative agent of gonorrheae, is repressed by the transcriptional regulator, MtrR (multiple transferable resistance repressor). Here, we report the results from a series of in vitro experiments to identify innate, human inducers of MtrR and to understand the biochemical and structural mechanisms of the gene regulatory function of MtrR. Isothermal titration calorimetry experiments reveal that MtrR binds the hormonal steroids progesterone, β-estradiol, and testosterone, all of which are present at significant concentrations at urogenital infection sites as well as ethinyl estrogen, a component of some birth control pills. Binding of these steroids results in decreased affinity of MtrR for cognate DNA, as demonstrated by fluorescence polarization-based assays. The crystal structures of MtrR bound to each steroid provided insight into the flexibility of the binding pocket, elucidated specific residue-ligand interactions, and revealed the conformational consequences of the induction mechanism of MtrR. Three residues, D171, W136 and R176 are key to the specific binding of these gonadal steroids. These studies provide a molecular understanding of the transcriptional regulation by MtrR that promotes N. gonorrhoeae survival in its human host.
Collapse
|
10
|
Pugh HL, Connor C, Siasat P, McNally A, Blair JMA. E. coli ST11 (O157:H7) does not encode a functional AcrF efflux pump. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001324. [PMID: 37074150 PMCID: PMC10202319 DOI: 10.1099/mic.0.001324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/23/2023] [Indexed: 04/20/2023]
Abstract
Escherichia coli is a facultative anaerobe found in a wide range of environments. Commonly described as the laboratory workhorse, E. coli is one of the best characterized bacterial species to date, however much of our understanding comes from studies involving the laboratory strain E. coli K-12. Resistance-nodulation-division efflux pumps are found in Gram-negative bacteria and can export a diverse range of substrates, including antibiotics. E. coli K-12 has six RND pumps; AcrB, AcrD, AcrF, CusA, MdtBC and MdtF, and it is frequently reported that all E. coli strains possess these six pumps. However, this is not true of E. coli ST11, a lineage of E. coli, which is primarily composed of the highly virulent important human pathogen, E. coli O157:H7. Here we show that acrF is absent from the pangenome of ST11 and that this lineage of E. coli has a highly conserved insertion within the acrF gene, which when translated encodes 13 amino acids and two stop codons. This insertion was found to be present in 97.59 % of 1787 ST11 genome assemblies. Non-function of AcrF in ST11 was confirmed in the laboratory as complementation with acrF from ST11 was unable to restore AcrF function in E. coli K-12 substr. MG1655 ΔacrB ΔacrF. This shows that the complement of RND efflux pumps present in laboratory bacterial strains may not reflect the situation in virulent strains of bacterial pathogens.
Collapse
Affiliation(s)
- Hannah L. Pugh
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Christopher Connor
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Pauline Siasat
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Alan McNally
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Jessica M. A. Blair
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| |
Collapse
|
11
|
Fanelli G, Pasqua M, Prosseda G, Grossi M, Colonna B. AcrAB efflux pump impacts on the survival of adherent-invasive Escherichia coli strain LF82 inside macrophages. Sci Rep 2023; 13:2692. [PMID: 36792672 PMCID: PMC9931695 DOI: 10.1038/s41598-023-29817-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
The tripartite complex AcrAB-TolC is the major RND pump in Escherichia coli and other Enterobacteriaceae. It consists of the AcrB transporter, which is embedded in the inner membrane, the AcrA adapter located in the periplasm, and the channel protein TolC responsible for the transport of substrates towards the extracellular environment. Besides conferring resistance to many classes of antibiotics, AcrAB plays a role in the pathogenesis and virulence of several bacterial pathogens. Here we report that the AcrAB pump heavily affects the infection process of the LF82 strain, the prototype of Adherent-Invasive Escherichia coli (AIEC) which are highly abundant in the ileal mucosa of Chron disease patients. We found that the deletion of genes encoding AcrA and/or AcrB leads to decreased survival of LF82 within macrophages. Ectopic AcrAB expression in a acrAB defective mutant restores the wild type condition. Furthermore, we demonstrate that inhibition of AcrB and replacement of the transporter with an unfunctional AcrB also interfere with bacterial viability inside macrophages. Overall, these data suggest a pivotal role of the AcrAB efflux pump in bacteria-host cell interactions also in AIEC.
Collapse
Affiliation(s)
- Giulia Fanelli
- grid.7841.aDepartment of Biology and Biotechnology “C. Darwin”, Istituto Pasteur Italia, Sapienza Università di Roma, Rome, Italy
| | - Martina Pasqua
- grid.7841.aDepartment of Biology and Biotechnology “C. Darwin”, Istituto Pasteur Italia, Sapienza Università di Roma, Rome, Italy
| | - Gianni Prosseda
- grid.7841.aDepartment of Biology and Biotechnology “C. Darwin”, Istituto Pasteur Italia, Sapienza Università di Roma, Rome, Italy
| | - Milena Grossi
- Department of Biology and Biotechnology "C. Darwin", Istituto Pasteur Italia, Sapienza Università di Roma, Rome, Italy.
| | - Bianca Colonna
- Department of Biology and Biotechnology "C. Darwin", Istituto Pasteur Italia, Sapienza Università di Roma, Rome, Italy.
| |
Collapse
|
12
|
Blair JMA, Zeth K, Bavro VN, Sancho-Vaello E. The role of bacterial transport systems in the removal of host antimicrobial peptides in Gram-negative bacteria. FEMS Microbiol Rev 2022; 46:6617596. [PMID: 35749576 PMCID: PMC9629497 DOI: 10.1093/femsre/fuac032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/23/2022] [Accepted: 06/22/2022] [Indexed: 01/09/2023] Open
Abstract
Antibiotic resistance is a global issue that threatens our progress in healthcare and life expectancy. In recent years, antimicrobial peptides (AMPs) have been considered as promising alternatives to the classic antibiotics. AMPs are potentially superior due to their lower rate of resistance development, since they primarily target the bacterial membrane ('Achilles' heel' of the bacteria). However, bacteria have developed mechanisms of AMP resistance, including the removal of AMPs to the extracellular space by efflux pumps such as the MtrCDE or AcrAB-TolC systems, and the internalization of AMPs to the cytoplasm by the Sap transporter, followed by proteolytic digestion. In this review, we focus on AMP transport as a resistance mechanism compiling all the experimental evidence for the involvement of efflux in AMP resistance in Gram-negative bacteria and combine this information with the analysis of the structures of the efflux systems involved. Finally, we expose some open questions with the aim of arousing the interest of the scientific community towards the AMPs-efflux pumps interactions. All the collected information broadens our understanding of AMP removal by efflux pumps and gives some clues to assist the rational design of AMP-derivatives as inhibitors of the efflux pumps.
Collapse
Affiliation(s)
- Jessica M A Blair
- College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Kornelius Zeth
- Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark
| | - Vassiliy N Bavro
- School of Life Sciences, University of Essex, Colchester, CO4 3SQ, United Kingdom
| | - Enea Sancho-Vaello
- Corresponding author. College of Medical and Dental Sciences, Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom. E-mail:
| |
Collapse
|
13
|
A Single Amino Acid Substitution in Elongation Factor G Can Confer Low-Level Gentamicin Resistance in Neisseria gonorrhoeae. Antimicrob Agents Chemother 2022; 66:e0025122. [PMID: 35465683 PMCID: PMC9112995 DOI: 10.1128/aac.00251-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The continued emergence of Neisseria gonorrhoeae isolates which are resistant to first-line antibiotics has reinvigorated interest in alternative therapies such as expanded use of gentamicin (Gen). We hypothesized that expanded use of Gen promotes emergence of gonococci with clinical resistance to this aminoglycoside. To understand how decreased susceptibility of gonococci to Gen might develop, we selected spontaneous low-level Gen-resistant (GenR) mutants (Gen MIC = 32 μg/mL) of the Gen-susceptible strain FA19. Consequently, we identified a novel missense mutation in fusA, which encodes elongation factor G (EF-G), causing an alanine (A) to valine (V) substitution at amino acid position 563 in domain IV of EF-G; the mutant allele was termed fusA2. Transformation analysis showed that fusA2 could increase the Gen MIC by 4-fold. While possession of fusA2 did not impair either in vitro gonococcal growth or protein synthesis, it did result in a fitness defect during experimental infection of the lower genital tract in female mice. Through bioinformatic analysis of whole-genome sequences of 10,634 international gonococcal clinical isolates, other fusA alleles were frequently detected, but genetic studies revealed that they could not decrease Gen susceptibility in a similar manner to fusA2. In contrast to these diverse international fusA alleles, the fusA2-encoded A563V substitution was detected in only a single gonococcal clinical isolate. We hypothesize that the rare occurrence of fusA2 in N. gonorrhoeae clinical isolates is likely due to a fitness cost during infection, but compensatory mutations which alleviate this fitness cost could emerge and promote GenR in global strains.
Collapse
|
14
|
Jain N, Sk MF, Mishra A, Kar P, Kumar A. Identification of novel Efflux pump inhibitors for Neisseria gonorrhoeae via multiple ligand-based pharmacophores, e-pharmacophore, molecular docking, density functional theory, and Molecular dynamics approaches. Comput Biol Chem 2022; 98:107682. [DOI: 10.1016/j.compbiolchem.2022.107682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/30/2022] [Accepted: 04/04/2022] [Indexed: 11/24/2022]
|
15
|
Heydarian M, Rühl E, Rawal R, Kozjak-Pavlovic V. Tissue Models for Neisseria gonorrhoeae Research—From 2D to 3D. Front Cell Infect Microbiol 2022; 12:840122. [PMID: 35223556 PMCID: PMC8873371 DOI: 10.3389/fcimb.2022.840122] [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: 12/20/2021] [Accepted: 01/24/2022] [Indexed: 12/02/2022] Open
Abstract
Neisseria gonorrhoeae is a human-specific pathogen that causes gonorrhea, the second most common sexually transmitted infection worldwide. Disease progression, drug discovery, and basic host-pathogen interactions are studied using different approaches, which rely on models ranging from 2D cell culture to complex 3D tissues and animals. In this review, we discuss the models used in N. gonorrhoeae research. We address both in vivo (animal) and in vitro cell culture models, discussing the pros and cons of each and outlining the recent advancements in the field of three-dimensional tissue models. From simple 2D monoculture to complex advanced 3D tissue models, we provide an overview of the relevant methodology and its application. Finally, we discuss future directions in the exciting field of 3D tissue models and how they can be applied for studying the interaction of N. gonorrhoeae with host cells under conditions closely resembling those found at the native sites of infection.
Collapse
|
16
|
Golparian D, Unemo M. Antimicrobial resistance prediction in Neisseria gonorrhoeae: Current status and future prospects. Expert Rev Mol Diagn 2021; 22:29-48. [PMID: 34872437 DOI: 10.1080/14737159.2022.2015329] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Several nucleic acid amplification tests (NAATs), mostly real-time PCRs, to detect antimicrobial resistance (AMR) determinants and predict AMR in Neisseria gonorrhoeae are promising, and some may be ready to apply at the point-of-care (POC), but important limitations remain with most NAATs. Next-generation sequencing (NGS) can overcome many of these limitations.Areas covered: Recent advances, with main focus on publications since 2017, in the development and use of NAATs and NGS to predict gonococcal AMR for surveillance and clinical use, and pros and cons of these tests as well as future perspectives for appropriate use of molecular AMR prediction for N. gonorrhoeae.Expert Commentary: NAATs and/or NGS for AMR prediction should supplement culture-based AMR surveillance, which will remain because it detects also AMR due to unknown AMR determinants, and translation into POC tests is imperative for the end-goal of individualized treatment, sparing ceftriaxone±azithromycin. Several challenges for direct testing of clinical, especially pharyngeal, specimens and for accurate prediction of cephalosporins and azithromycin resistance, especially using NAATs, remain. The choice of AMR prediction assay needs to carefully consider the intended use of the assay; limitations intrinsic to the AMR prediction technology, algorithms and specific to chosen methodology; specimen types analyzed; and cost-effectiveness.
Collapse
Affiliation(s)
- Daniel Golparian
- WHO Collaborating Centre for Gonorrhoea and other STIs, National Reference Laboratory for STIs, Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and other STIs, National Reference Laboratory for STIs, Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| |
Collapse
|
17
|
Kanesaka I, Ohno A, Katsuse AK, Takahashi H, Kobayashi I. The emergence of the ceftriaxone-resistant Neisseria gonorrhoeae FC428 clone by transfer of resistance from an oral Neisseria subflava reservoir of resistance. J Antimicrob Chemother 2021; 77:364-373. [PMID: 34747462 DOI: 10.1093/jac/dkab390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 10/05/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The ceftriaxone-resistant Neisseria gonorrhoeae FC428 clone was first discovered in Japan in 2015. OBJECTIVES We investigated the possibility of horizontal gene transfer from Neisseria subflava harbouring the mosaic-like PBP-2 in the emergence of the FC428 clone. We also analysed whether there were fitness costs associated with the sustained international dissemination of the clone. METHODS Sequencing of the penA gene in ceftriaxone-resistant N. subflava strains was performed. For transformation experiments between donor N. subflava and ciprofloxacin-resistant wild-type penA N. gonorrhoeae recipient, the full-length PCR amplification product of the penA gene, including DUS regions, was used as the donor DNA. Biological fitness of the transformants was measured by growth competition assays. The impact of QRDR and mtrR mutations, which have been reported as compensatory mutations, on fitness was also assessed. RESULTS The penA mosaic allele of the FC428 clone showed 100%, 91.8%, and 89.8% homology, respectively, with penA genes of three ceftriaxone-resistant N. subflava strains, No. 30, No. 9 and No. 14. Results were consistent with homologous recombination with the donated penA mosaic allele. In co-cultures with the parent strain, transformants showed comparable growth indicating that a gyrA mutation compensates for the fitness cost of mosaic penA alleles. CONCLUSIONS Our findings support the hypothesis that the FC428 clone was generated by transformation of the mosaic penA allele from oropharyngeal N. subflava to N. gonorrhoeae. Furthermore, it suggests that mutations in the gyrA QRDR region compensate for fitness costs and contribute to the continued transmission of the FC428 clone.
Collapse
Affiliation(s)
- Izumo Kanesaka
- Department of Infection Control and Prevention, Faculty of Nursing, Toho University, 4-16-20, Omori-nishi, Ota-ku, Tokyo 143-0015, Japan
| | - Akira Ohno
- Department of Infection Control and Prevention, Faculty of Nursing, Toho University, 4-16-20, Omori-nishi, Ota-ku, Tokyo 143-0015, Japan
| | - Akiko Kanayama Katsuse
- Department of Infection Control and Prevention, Faculty of Nursing, Toho University, 4-16-20, Omori-nishi, Ota-ku, Tokyo 143-0015, Japan
| | - Hiroshi Takahashi
- Department of Infection Control and Prevention, Faculty of Nursing, Toho University, 4-16-20, Omori-nishi, Ota-ku, Tokyo 143-0015, Japan
| | - Intetsu Kobayashi
- Department of Infection Control and Prevention, Faculty of Nursing, Toho University, 4-16-20, Omori-nishi, Ota-ku, Tokyo 143-0015, Japan
| |
Collapse
|
18
|
Ammerman L, Mertz SB, Park C, Wise JG. Transport Dynamics of MtrD: An RND Multidrug Efflux Pump from Neisseria gonorrheae. Biochemistry 2021; 60:3098-3113. [PMID: 34609833 DOI: 10.1021/acs.biochem.1c00399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The MtrCDE system confers multidrug resistance to Neisseria gonorrheae, the causative agent of gonorrhea. Using free and directed molecular dynamics (MD) simulations, we analyzed the interactions between MtrD and azithromycin, a transport substrate of MtrD, and a last-resort clinical treatment for multidrug-resistant gonorrhea. We then simulated the interactions between MtrD and streptomycin, an apparent nonsubstrate of MtrD. Using known conformations of MtrD homologues, we simulated a potential dynamic transport cycle of MtrD using targeted MD techniques (TMD), and we noted that forces were not applied to ligands of interest. In these TMD simulations, we observed the transport of azithromycin and the rejection of streptomycin. In an unbiased, long-time scale simulation of AZY-bound MtrD, we observed the spontaneous diffusion of azithromycin through the periplasmic cleft. Our simulations show how the peristaltic motions of the periplasmic cleft facilitate the transport of substrates by MtrD. Our data also suggest that multiple transport pathways for macrolides may exist within the periplasmic cleft of MtrD.
Collapse
Affiliation(s)
- Lauren Ammerman
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Research Computing, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas 75275-0376, United States
| | - Sarah B Mertz
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Research Computing, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas 75275-0376, United States
| | - Chanyang Park
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas 75275-0376, United States
| | - John G Wise
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Research Computing, Southern Methodist University, Dallas, Texas 75275-0376, United States.,Center for Drug Discovery, Design and Delivery, Southern Methodist University, Dallas, Texas 75275-0376, United States
| |
Collapse
|
19
|
Ramli SR, Bunk B, Spröer C, Geffers R, Jarek M, Bhuju S, Goris M, Mustakim S, Pessler F. Complete Genome Sequencing of Leptospira interrogans Isolates from Malaysia Reveals Massive Genome Rearrangement but High Conservation of Virulence-Associated Genes. Pathogens 2021; 10:pathogens10091198. [PMID: 34578230 PMCID: PMC8467490 DOI: 10.3390/pathogens10091198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 11/16/2022] Open
Abstract
The ability of Leptospirae to persist in environments and animal hosts but to cause clinically highly variable disease in humans has made leptospirosis the most common zoonotic disease. Considering the paucity of data on variation in complete genomes of human pathogenic Leptospirae, we have used a combination of Single Molecule Real-Time (SMRT) and Illumina sequencing to obtain complete genome sequences of six human clinical L. interrogans isolates from Malaysia. All six contained the larger (4.28–4.56 Mb) and smaller (0.34–0.395 Mb) chromosome typical of human pathogenic Leptospirae and 0–7 plasmids. Only 24% of the plasmid sequences could be matched to databases. We identified a chromosomal core genome of 3318 coding sequences and strain-specific accessory genomes of 49–179 coding sequences. These sequences enabled detailed genomic strain typing (Genome BLAST Distance Phylogeny, DNA–DNA hybridization, and multi locus sequence typing) and phylogenetic classification (whole-genome SNP genotyping). Even though there was some shared synteny and collinearity across the six genomes, there was evidence of major genome rearrangement, likely driven by horizontal gene transfer and homologous recombination. Mobile genetic elements were identified in all strains in highly varying numbers, including in the rfb locus, which defines serogroups and contributes to immune escape and pathogenesis. On the other hand, there was high conservation of virulence-associated genes including those relating to sialic acid, alginate, and lipid A biosynthesis. These findings suggest (i) that the antigenic variation, adaption to various host environments, and broad spectrum of virulence of L. interrogans are in part due to a high degree of genomic plasticity and (ii) that human pathogenic strains maintain a core set of genes required for virulence.
Collapse
Affiliation(s)
- Siti Roszilawati Ramli
- Research Group Biomarkers for Infectious Diseases, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
- Department of Biotechnology, Technical University Braunschweig, 38106 Braunschweig, Germany
- Bacteriology Unit, Institute for Medical Research, National Institute of Health, Setia Alam 40170, Malaysia
| | - Boyke Bunk
- Leibniz Institute German Collection of Microorganisms and Cell Cultures (DSMZ), 38124 Braunschweig, Germany; (B.B.); (C.S.)
| | - Cathrin Spröer
- Leibniz Institute German Collection of Microorganisms and Cell Cultures (DSMZ), 38124 Braunschweig, Germany; (B.B.); (C.S.)
| | - Robert Geffers
- Genome Analytics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (R.G.); (M.J.); (S.B.)
| | - Michael Jarek
- Genome Analytics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (R.G.); (M.J.); (S.B.)
| | - Sabin Bhuju
- Genome Analytics, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany; (R.G.); (M.J.); (S.B.)
| | - Marga Goris
- Leptospirosis Reference Centre, Amsterdam Medical Centre, University of Amsterdam, 1100 DD Amsterdam, The Netherlands;
| | - Sahlawati Mustakim
- Department of Pathology, Hospital Tuanku Ampuan Rahimah, Klang 41672, Malaysia;
| | - Frank Pessler
- Research Group Biomarkers for Infectious Diseases, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany;
- Centre for Individualised Infection Medicine, 30625 Hannover, Germany
- Research Group Biomarkers for Infectious Diseases, TWINCORE Center for Experimental and Clinical Infection Research, 30625 Hannover, Germany
- Correspondence: or ; Tel.: +49-(0)511-220027-167; Fax: +49-(0)511-220027-186
| |
Collapse
|
20
|
Bettoni S, Maziarz K, Stone MRL, Blaskovich MAT, Potempa J, Bazzo ML, Unemo M, Ram S, Blom AM. Serum Complement Activation by C4BP-IgM Fusion Protein Can Restore Susceptibility to Antibiotics in Neisseria gonorrhoeae. Front Immunol 2021; 12:726801. [PMID: 34539665 PMCID: PMC8440848 DOI: 10.3389/fimmu.2021.726801] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/12/2021] [Indexed: 11/13/2022] Open
Abstract
Neisseria gonorrhoeae is the etiological agent of gonorrhea, the second most common bacterial sexually transmitted infection worldwide. Reproductive sequelae of gonorrhea include infertility, ectopic pregnancy and chronic pelvic pain. Most antibiotics currently in clinical use have been rendered ineffective due to the rapid spread of antimicrobial resistance among gonococci. The developmental pipeline of new antibiotics is sparse and novel therapeutic approaches are urgently needed. Previously, we utilized the ability of N. gonorrhoeae to bind the complement inhibitor C4b-binding protein (C4BP) to evade killing by human complement to design a chimeric protein that linked the two N-terminal gonococcal binding domains of C4BP with the Fc domain of IgM. The resulting molecule, C4BP-IgM, enhanced complement-mediated killing of gonococci. Here we show that C4BP-IgM induced membrane perturbation through complement deposition and membrane attack complex pore insertion facilitates the access of antibiotics to their intracellular targets. Consequently, bacteria become more susceptible to killing by antibiotics. Remarkably, C4BP-IgM restored susceptibility to azithromycin of two azithromycin-resistant clinical gonococcal strains because of overexpression of the MtrC-MtrD-MtrE efflux pump. Our data show that complement activation can potentiate activity of antibiotics and suggest a role for C4BP-IgM as an adjuvant for antibiotic treatment of drug-resistant gonorrhea.
Collapse
Affiliation(s)
- Serena Bettoni
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Karolina Maziarz
- Department of Translational Medicine, Lund University, Malmö, Sweden
| | - M Rhia L Stone
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Jan Potempa
- Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Oral Immunity and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, United States
| | - Maria Luiza Bazzo
- Molecular Biology, Microbiology and Serology Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Magnus Unemo
- World Health Organization (WHO) Collaborating Centre for Gonorrhoea and other STIs, Department of Laboratory Medicine, Örebro University, Örebro, Sweden
| | - Sanjay Ram
- Department of Medicine, Division of Infectious Diseases, University of Massachusetts Medical School, Worcester, MA, United States
| | - Anna M. Blom
- Department of Translational Medicine, Lund University, Malmö, Sweden
| |
Collapse
|
21
|
Hawley KL, Montezuma-Rusca JM, Delgado KN, Singh N, Uversky VN, Caimano MJ, Radolf JD, Luthra A. Structural Modeling of the Treponema pallidum Outer Membrane Protein Repertoire: a Road Map for Deconvolution of Syphilis Pathogenesis and Development of a Syphilis Vaccine. J Bacteriol 2021; 203:e0008221. [PMID: 33972353 PMCID: PMC8407342 DOI: 10.1128/jb.00082-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/27/2021] [Indexed: 01/11/2023] Open
Abstract
Treponema pallidum, an obligate human pathogen, has an outer membrane (OM) whose physical properties, ultrastructure, and composition differ markedly from those of phylogenetically distant Gram-negative bacteria. We developed structural models for the outer membrane protein (OMP) repertoire (OMPeome) of T. pallidum Nichols using solved Gram-negative structures, computational tools, and small-angle X-ray scattering (SAXS) of selected recombinant periplasmic domains. The T. pallidum "OMPeome" harbors two "stand-alone" proteins (BamA and LptD) involved in OM biogenesis and four paralogous families involved in the influx/efflux of small molecules: 8-stranded β-barrels, long-chain-fatty-acid transporters (FadLs), OM factors (OMFs) for efflux pumps, and T. pallidum repeat proteins (Tprs). BamA (TP0326), the central component of a β-barrel assembly machine (BAM)/translocation and assembly module (TAM) hybrid, possesses a highly flexible polypeptide-transport-associated (POTRA) 1-5 arm predicted to interact with TamB (TP0325). TP0515, an LptD ortholog, contains a novel, unstructured C-terminal domain that models inside the β-barrel. T. pallidum has four 8-stranded β-barrels, each containing positively charged extracellular loops that could contribute to pathogenesis. Three of five FadL-like orthologs have a novel α-helical, presumptively periplasmic C-terminal extension. SAXS and structural modeling further supported the bipartite membrane topology and tridomain architecture of full-length members of the Tpr family. T. pallidum's two efflux pumps presumably extrude noxious small molecules via four coexpressed OMFs with variably charged tunnels. For BamA, LptD, and OMFs, we modeled the molecular machines that deliver their substrates into the OM or external milieu. The spirochete's extended families of OM transporters collectively confer a broad capacity for nutrient uptake. The models also furnish a structural road map for vaccine development. IMPORTANCE The unusual outer membrane (OM) of T. pallidum, the syphilis spirochete, is the ultrastructural basis for its well-recognized capacity for invasiveness, immune evasion, and persistence. In recent years, we have made considerable progress in identifying T. pallidum's repertoire of OMPs. Here, we developed three-dimensional (3D) models for the T. pallidum Nichols OMPeome using structural modeling, bioinformatics, and solution scattering. The OM contains three families of OMP transporters, an OMP family involved in the extrusion of noxious molecules, and two "stand-alone" proteins involved in OM biogenesis. This work represents a major advance toward elucidating host-pathogen interactions during syphilis; understanding how T. pallidum, an extreme auxotroph, obtains a wide array of biomolecules from its obligate human host; and developing a vaccine with global efficacy.
Collapse
Affiliation(s)
- Kelly L. Hawley
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases and Immunology, Connecticut Children’s, Hartford, Connecticut, USA
| | - Jairo M. Montezuma-Rusca
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Division of Infectious Diseases, UConn Health, Farmington, Connecticut, USA
| | | | - Navreeta Singh
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Melissa J. Caimano
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Justin D. Radolf
- Department of Pediatrics, UConn Health, Farmington, Connecticut, USA
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
- Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA
- Department of Immunology, UConn Health, Farmington, Connecticut, USA
| | - Amit Luthra
- Department of Medicine, UConn Health, Farmington, Connecticut, USA
- Department of Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| |
Collapse
|
22
|
Fairweather SJ, Gupta V, Chitsaz M, Booth L, Brown MH, O’Mara ML. Coordination of Substrate Binding and Protonation in the N. gonorrhoeae MtrD Efflux Pump Controls the Functionally Rotating Transport Mechanism. ACS Infect Dis 2021; 7:1833-1847. [PMID: 33980014 DOI: 10.1021/acsinfecdis.1c00149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Multidrug resistance is a serious problem that threatens the effective treatment of the widespread sexually transmitted disease gonorrhea, caused by the Gram-negative bacterium Neisseria gonorrhoeae. The drug efflux pump primarily implicated in N. gonorrhoeae antimicrobial resistance is the inner membrane transporter MtrD, which forms part of the tripartite multiple transferable resistance (Mtr) CDE efflux system. A structure of MtrD was first solved in 2014 as a symmetrical homotrimer, and then, recently, as an asymmetrical homotrimer. Through a series of molecular dynamics simulations and mutagenesis experiments, we identify the combination of substrate binding and protonation states of the proton relay network that drives the transition from the symmetric to the asymmetric conformation of MtrD. We characterize the allosteric coupling between the functionally important local regions that control conformational changes between the access, binding, and extrusion states and allow for transition to the asymmetric MtrD conformation. We also highlight a significant rotation of the transmembrane helices caused by protonation of the proton relay network, which widens the intermonomeric gap that is a hallmark of the rotational transporter mechanism. This is the first analysis and description of the transport mechanism for the N. gonorrhoeae MtrD transporter and provides evidence that antimicrobial efflux in MtrD follows the functionally rotating transport mechanism seen in protein homologues from the same transport protein superfamily.
Collapse
Affiliation(s)
- Stephen J. Fairweather
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Vrinda Gupta
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - Mohsen Chitsaz
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia
| | - Lauren Booth
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - Melissa H. Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia
| | - Megan L. O’Mara
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| |
Collapse
|
23
|
Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
Collapse
Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
| |
Collapse
|
24
|
Henderson PJF, Maher C, Elbourne LDH, Eijkelkamp BA, Paulsen IT, Hassan KA. Physiological Functions of Bacterial "Multidrug" Efflux Pumps. Chem Rev 2021; 121:5417-5478. [PMID: 33761243 DOI: 10.1021/acs.chemrev.0c01226] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacterial multidrug efflux pumps have come to prominence in human and veterinary pathogenesis because they help bacteria protect themselves against the antimicrobials used to overcome their infections. However, it is increasingly realized that many, probably most, such pumps have physiological roles that are distinct from protection of bacteria against antimicrobials administered by humans. Here we undertake a broad survey of the proteins involved, allied to detailed examples of their evolution, energetics, structures, chemical recognition, and molecular mechanisms, together with the experimental strategies that enable rapid and economical progress in understanding their true physiological roles. Once these roles are established, the knowledge can be harnessed to design more effective drugs, improve existing microbial production of drugs for clinical practice and of feedstocks for commercial exploitation, and even develop more sustainable biological processes that avoid, for example, utilization of petroleum.
Collapse
Affiliation(s)
- Peter J F Henderson
- School of Biomedical Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Claire Maher
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia
| | - Liam D H Elbourne
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Bart A Eijkelkamp
- College of Science and Engineering, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Ian T Paulsen
- Department of Biomolecular Sciences, Macquarie University, Sydney 2109, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, New South Wales, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney 2019, New South Wales, Australia
| |
Collapse
|
25
|
Jefferson A, Smith A, Fasinu PS, Thompson DK. Sexually Transmitted Neisseria gonorrhoeae Infections-Update on Drug Treatment and Vaccine Development. MEDICINES 2021; 8:medicines8020011. [PMID: 33562607 PMCID: PMC7914478 DOI: 10.3390/medicines8020011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/17/2021] [Accepted: 02/03/2021] [Indexed: 12/15/2022]
Abstract
Background: Sexually transmitted gonorrhea, caused by the Gram-negative diplococcus Neisseria gonorrhoeae, continues to be a serious global health challenge despite efforts to eradicate it. Multidrug resistance among clinical N. gonorrhoeae isolates has limited treatment options, and attempts to develop vaccines have not been successful. Methods: A search of published literature was conducted, and information extracted to provide an update on the status of therapeutics and vaccine development for gonorrheal infection. Results: Recommended pharmacological treatment for gonorrhea has changed multiple times due to increasing acquisition of resistance to existing antibiotics by N. gonorrhoeae. Only broad-spectrum cephalosporin-based combination therapies are currently recommended for treatment of uncomplicated urogenital and anorectal gonococcal infections. With the reported emergence of ceftriaxone resistance, successful strategies addressing the global burden of gonorrhea must include vaccination. Century-old efforts at developing an effective vaccine against gonorrhea, leading to only four clinical trials, have not yielded any successful vaccine. Conclusions: While it is important to continue to explore new drugs for the treatment of gonorrhea, the historical trend of resistance acquisition suggests that any long-term strategy should include vaccine development. Advanced technologies in proteomics and in silico approaches to vaccine target identification may provide templates for future success.
Collapse
Affiliation(s)
- Amber Jefferson
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Amanda Smith
- School of Pharmacy, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA; (A.J.); (A.S.)
| | - Pius S. Fasinu
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
| | - Dorothea K. Thompson
- Department of Pharmaceutical Sciences, College of Pharmacy & Health Sciences, Campbell University, Buies Creek, NC 27506, USA;
- Correspondence: ; Tel.: +1-910-893-7463
| |
Collapse
|
26
|
Comprehensive Bioinformatic Assessments of the Variability of Neisseria gonorrhoeae Vaccine Candidates. mSphere 2021; 6:6/1/e00977-20. [PMID: 33536323 PMCID: PMC7860988 DOI: 10.1128/msphere.00977-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A protective vaccine is the only viable way to stop the spread of gonorrhea in the face of rising antibiotic resistance. However, the notorious phase and antigenic variation of Neisseria gonorrhoeae surface proteins remains one of the challenges in vaccine development. To facilitate vaccine advancement efforts, we carried out comprehensive bioinformatic analyses of sequence variation by comparing 34 gonorrhea antigen candidates among >5,000 clinical N. gonorrhoeae isolates deposited in the Neisseria PubMLST database. Eight protein antigens showed exceptional conservation by having a single allele variant distributed in >80% of isolates. An additional 18 vaccine candidates were represented by ≤3 alleles in >50% of N. gonorrhoeae isolates globally. Phylogenetic analyses highlighted closely related antigen variants and additionally showed that AniA and FetB were the closest between N. gonorrhoeae and N. meningitidis Up to 44% of N. meningitidis alleles for both antigens have premature stop codons, suggesting differential expression. Mapping polymorphisms to the available three-dimensional structures of 12 antigens revealed low-frequency surface polymorphisms. PorB and TbpB possessed numerous high-prevalence polymorphic sites. While TbpA was also highly variable, conserved loops were nonetheless identified. A high degree of sequence conservation, the distribution of a single antigen variant among N. gonorrhoeae strains globally, or low-frequency sequence polymorphisms in surface loops make ACP, AniA, BamA, BamE, MtrE, NspA, NGO0778, NGO1251, NGO1985, OpcA, PldA, Slam2, and ZnuD promising candidates for a gonorrhea vaccine. Finally, the commonly used N. gonorrhoeae FA1090 strain emerges as a vaccine prototype, as it carries antigen sequence types identical to the most broadly distributed antigen variants.IMPORTANCE Neisseria gonorrhoeae, the Gram-negative bacterium responsible for the sexually transmitted infection gonorrhea, is categorized as a high-priority pathogen for research and development efforts. N. gonorrhoeae's "superbug" status, its high morbidity, and the serious health impact associated with gonorrhea highlight the importance of vaccine development. One of the longstanding barriers to developing an effective vaccine against N. gonorrhoeae is the remarkable variability of surface-exposed antigens. In this report, we addressed this roadblock by applying extensive bioinformatic analyses to 34 gonorrhea antigen candidates among >5,000 clinical N. gonorrhoeae isolates. Our studies are important, as they reveal promising, conserved gonorrhea vaccine candidates and aid structural vaccinology. Moreover, these approaches are broadly applicable to other infectious diseases where surface antigen variability impedes successful vaccine design.
Collapse
|
27
|
Lim KYL, Mullally CA, Haese EC, Kibble EA, McCluskey NR, Mikucki EC, Thai VC, Stubbs KA, Sarkar-Tyson M, Kahler CM. Anti-Virulence Therapeutic Approaches for Neisseria gonorrhoeae. Antibiotics (Basel) 2021; 10:antibiotics10020103. [PMID: 33494538 PMCID: PMC7911339 DOI: 10.3390/antibiotics10020103] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 01/15/2023] Open
Abstract
While antimicrobial resistance (AMR) is seen in both Neisseria gonorrhoeae and Neisseria meningitidis, the former has become resistant to commonly available over-the-counter antibiotic treatments. It is imperative then to develop new therapies that combat current AMR isolates whilst also circumventing the pathways leading to the development of AMR. This review highlights the growing research interest in developing anti-virulence therapies (AVTs) which are directed towards inhibiting virulence factors to prevent infection. By targeting virulence factors that are not essential for gonococcal survival, it is hypothesized that this will impart a smaller selective pressure for the emergence of resistance in the pathogen and in the microbiome, thus avoiding AMR development to the anti-infective. This review summates the current basis of numerous anti-virulence strategies being explored for N. gonorrhoeae.
Collapse
Affiliation(s)
- Katherine Y. L. Lim
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Christopher A. Mullally
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Ethan C. Haese
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Emily A. Kibble
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Nicolie R. McCluskey
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Edward C. Mikucki
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Van C. Thai
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Keith A. Stubbs
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia;
| | - Mitali Sarkar-Tyson
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
| | - Charlene M. Kahler
- Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Crawley, WA 6009, Australia; (K.Y.L.L.); (C.A.M.); (E.C.H.); (E.A.K.); (N.R.M.); (E.C.M.); (V.C.T.); (M.S.-T.)
- Correspondence:
| |
Collapse
|
28
|
The serogroup B meningococcal outer membrane vesicle-based vaccine 4CMenB induces cross-species protection against Neisseria gonorrhoeae. PLoS Pathog 2020; 16:e1008602. [PMID: 33290434 PMCID: PMC7748408 DOI: 10.1371/journal.ppat.1008602] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/18/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
There is a pressing need for a gonorrhea vaccine due to the high disease burden associated with gonococcal infections globally and the rapid evolution of antibiotic resistance in Neisseria gonorrhoeae (Ng). Current gonorrhea vaccine research is in the stages of antigen discovery and the identification of protective immune responses, and no vaccine has been tested in clinical trials in over 30 years. Recently, however, it was reported in a retrospective case-control study that vaccination of humans with a serogroup B Neisseria meningitidis (Nm) outer membrane vesicle (OMV) vaccine (MeNZB) was associated with reduced rates of gonorrhea. Here we directly tested the hypothesis that Nm OMVs induce cross-protection against gonorrhea in a well-characterized female mouse model of Ng genital tract infection. We found that immunization with the licensed Nm OMV-based vaccine 4CMenB (Bexsero) significantly accelerated clearance and reduced the Ng bacterial burden compared to administration of alum or PBS. Serum IgG and vaginal IgA and IgG that cross-reacted with Ng OMVs were induced by 4CMenB vaccination by either the subcutaneous or intraperitoneal routes. Antibodies from vaccinated mice recognized several Ng surface proteins, including PilQ, BamA, MtrE, NHBA (known to be recognized by humans), PorB, and Opa. Immune sera from both mice and humans recognized Ng PilQ and several proteins of similar apparent molecular weight, but MtrE was only recognized by mouse serum. Pooled sera from 4CMenB-immunized mice showed a 4-fold increase in serum bactericidal50 titers against the challenge strain; in contrast, no significant difference in bactericidal activity was detected when sera from 4CMenB-immunized and unimmunized subjects were compared. Our findings directly support epidemiological evidence that Nm OMVs confer cross-species protection against gonorrhea, and implicate several Ng surface antigens as potentially protective targets. Additionally, this study further defines the usefulness of murine infection model as a relevant experimental system for gonorrhea vaccine development.
Collapse
|
29
|
Draft Genome Sequence of Serratia marcescens Strain ZZCCN01, Isolated from the Cardiac Blood of a Beef Cow. Microbiol Resour Announc 2020; 9:9/49/e00728-20. [PMID: 33272984 PMCID: PMC7714838 DOI: 10.1128/mra.00728-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Serratia marcescens strain ZZCCN01 was isolated from the cardiac blood of a dead beef cow with a lung infection and a foam-like secretion from the nostril. Here, we introduce the 5.1-Mb draft genome sequence, which comprises 105 scaffolds, and the corresponding annotation.
Collapse
|
30
|
Zhou K, Chen SC, Yang F, van der Veen S, Yin YP. Impact of the gonococcal FC428 penA allele 60.001 on ceftriaxone resistance and biological fitness. Emerg Microbes Infect 2020; 9:1219-1229. [PMID: 32438866 PMCID: PMC7448936 DOI: 10.1080/22221751.2020.1773325] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/30/2020] [Accepted: 05/19/2020] [Indexed: 12/23/2022]
Abstract
Global dissemination of the Neisseria gonorrhoeae ceftriaxone-resistant FC428 clone jeopardizes the currently recommended ceftriaxone-based first-line therapies. Ceftriaxone resistance in the FC428 clone has been associated with the presence of its mosaic penA allele 60.001. Here we investigated the contribution penA allele 60.001 to ceftriaxone resistance and its impact on biological fitness. Gonococcal isolates expressing penA allele 60.001 and mosaic penA allele 10.001, which is widespread in the Asia-Pacific region and associated with reduced susceptibility to ceftriaxone and cefixime, were genetic engineered to exchange their penA alleles. Subsequent antimicrobial susceptibility analyses showed that mutants containing penA 60.001 displayed 8- to 16-fold higher ceftriaxone and cefixime minimal inhibitory concentrations (MICs) compared with otherwise isogenic mutants containing penA 10.001. Further analysis of biological fitness showed that in vitro liquid growth of single strains and in the competition was identical between the isogenic penA allele exchange mutants. However, in the presence of high concentrations of palmitic acid or lithocholic acid, the penA 60.001-containing mutants grew better than the isogenic penA 10.001-containing mutants when grown as single strains. In contrast, the penA 10.001 mutants outcompeted the penA 60.001 mutants when grown in competition at slightly lower palmitic acid or lithocholic acid concentrations. Finally, the penA 60.001 mutants were outcompeted by their penA 10.001 counterparts for in vivo colonization and survival in a mouse vaginal tract infection model. In conclusion, penA allele 60.001 is essential for ceftriaxone resistance of the FC428 clone, while its impact on biological fitness is dependent on the specific growth conditions.
Collapse
Affiliation(s)
- Ke Zhou
- Peking Union Medical College, Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, People’s Republic of China
- National Center for STD Control, China Center for Disease Control and Prevention, Nanjing, People’s Republic of China
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
| | - Shao-Chun Chen
- Peking Union Medical College, Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, People’s Republic of China
- National Center for STD Control, China Center for Disease Control and Prevention, Nanjing, People’s Republic of China
| | - Fan Yang
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
| | - Stijn van der Veen
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
- Department of Dermatology, School of Medicine, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, People’s Republic of China
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, People’s Republic of China
| | - Yue-Ping Yin
- Peking Union Medical College, Institute of Dermatology, Chinese Academy of Medical Sciences, Nanjing, People’s Republic of China
- National Center for STD Control, China Center for Disease Control and Prevention, Nanjing, People’s Republic of China
| |
Collapse
|
31
|
Characterization of Posttranslationally Modified Multidrug Efflux Pumps Reveals an Unexpected Link between Glycosylation and Antimicrobial Resistance. mBio 2020; 11:mBio.02604-20. [PMID: 33203757 PMCID: PMC7683400 DOI: 10.1128/mbio.02604-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The substantial rise in multidrug-resistant bacterial infections is a current global imperative. Cumulative efforts to characterize antimicrobial resistance in bacteria has demonstrated the spread of six families of multidrug efflux pumps, of which resistance-nodulation-cell division (RND) is the major mechanism of multidrug resistance in Gram-negative bacteria. RND is composed of a tripartite protein assembly and confers resistance to a range of unrelated compounds. In the major enteric pathogen Campylobacter jejuni, the three protein components of RND are posttranslationally modified with N-linked glycans. The direct role of N-linked glycans in C. jejuni and other bacteria has long been elusive. Here, we present the first detailed account of the role of N-linked glycans and the link between N-glycosylation and antimicrobial resistance in C. jejuni We demonstrate the multifunctional role of N-linked glycans in enhancing protein thermostability, stabilizing protein complexes and the promotion of protein-protein interaction, thus mediating antimicrobial resistance via enhancing multidrug efflux pump activity. This affirms that glycosylation is critical for multidrug efflux pump assembly. We present a generalized strategy that could be used to investigate general glycosylation system in Campylobacter genus and a potential target to develop antimicrobials against multidrug-resistant pathogens.IMPORTANCE Nearly all bacterial species have at least a single glycosylation system, but the direct effects of these posttranslational protein modifications are unresolved. Glycoproteome-wide analysis of several bacterial pathogens has revealed general glycan modifications of virulence factors and protein assemblies. Using Campylobacter jejuni as a model organism, we have studied the role of general N-linked glycans in the multidrug efflux pump commonly found in Gram-negative bacteria. We show, for the first time, the direct link between N-linked glycans and multidrug efflux pump activity. At the protein level, we demonstrate that N-linked glycans play a role in enhancing protein thermostability and mediating the assembly of the multidrug efflux pump to promote antimicrobial resistance, highlighting the importance of this posttranslational modification in bacterial physiology. Similar roles for glycans are expected to be found in other Gram-negative pathogens that possess general protein glycosylation systems.
Collapse
|
32
|
Selective Inhibition of Coxiella burnetii Replication by the Steroid Hormone Progesterone. Infect Immun 2020; 88:IAI.00894-19. [PMID: 32928965 PMCID: PMC7671902 DOI: 10.1128/iai.00894-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 09/09/2020] [Indexed: 01/09/2023] Open
Abstract
Coxiella burnetii is a zoonotic bacterial obligate intracellular parasite and the cause of query (Q) fever. During natural infection of female animals, C. burnetii shows tropism for the placenta and is associated with late-term abortion, at which time the pathogen titer in placental tissue can exceed one billion bacteria per gram. During later stages of pregnancy, placental trophoblasts serve as the major source of progesterone, a steroid hormone known to affect the replication of some pathogens. During infection of placenta-derived JEG-3 cells, C. burnetii showed sensitivity to progesterone but not the immediate precursor pregnenolone or estrogen, another major mammalian steroid hormone. Using host cell-free culture, progesterone was determined to have a direct inhibitory effect on C. burnetii replication. Synergy between the inhibitory effect of progesterone and the efflux pump inhibitors verapamil and 1-(1-naphthylmethyl)-piperazine is consistent with a role for efflux pumps in preventing progesterone-mediated inhibition of C. burnetii activity. The sensitivity of C. burnetii to progesterone, but not structurally related molecules, is consistent with the ability of progesterone to influence pathogen replication in progesterone-producing tissues.
Collapse
|
33
|
Gao L, Wang Z, van der Veen S. Gonococcal Adaptation to Palmitic Acid Through farAB Expression and FadD Activity Mutations Increases In Vivo Fitness in a Murine Genital Tract Infection Model. J Infect Dis 2020; 224:141-150. [PMID: 33170275 DOI: 10.1093/infdis/jiaa701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022] Open
Abstract
Neisseria gonorrhoeae is a bacterial pathogen that colonizes mucosal epithelia that are rich in antimicrobial molecules such as long-chain fatty acids. Here we studied the mechanisms involved in palmitic acid resistance and their impact on in vivo biological fitness in a murine genital tract infection model. A stable palmitic acid-resistant derivative was obtained by serial passage with incremental palmitic acid concentrations. This derivative outcompeted its parent strain for colonization and survival in the murine infection model. Subsequent whole-genome sequencing resulted in the identification of the 3 resistance-related SNPs ihfAC5T, fadDC772T, and farAG-52T (promoter) that were verified for resistance against palmitic acid. Subsequent characterization of the associated resistance determinants showed that ihfAC5T and farAG-52T induced gene expression of the FarAB efflux pump, whereas fadDC772T increased the maximum enzyme activity of the FadD long-chain fatty acid-coenzyme A ligase. Our results highlight the mechanisms involved in gonococcal adaptation to the murine host environment.
Collapse
Affiliation(s)
- Lingyu Gao
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhemin Wang
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Stijn van der Veen
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| |
Collapse
|
34
|
Dubb RK, Nothaft H, Beadle B, Richards MR, Szymanski CM. N-glycosylation of the CmeABC multidrug efflux pump is needed for optimal function in Campylobacter jejuni. Glycobiology 2020; 30:105-119. [PMID: 31588498 DOI: 10.1093/glycob/cwz082] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/20/2022] Open
Abstract
Campylobacter jejuni is a prevalent gastrointestinal pathogen associated with increasing rates of antimicrobial resistance development. It was also the first bacterium demonstrated to possess a general N-linked protein glycosylation pathway capable of modifying > 80 different proteins, including the primary Campylobacter multidrug efflux pump, CmeABC. Here we demonstrate that N-glycosylation is necessary for the function of the efflux pump and may, in part, explain the evolutionary pressure to maintain this protein modification system. Mutants of cmeA in two common wildtype (WT) strains are highly susceptible to erythromycin (EM), ciprofloxacin and bile salts when compared to the isogenic parental strains. Complementation of the cmeA mutants with the native cmeA allele restores the WT phenotype, whereas expression of a cmeA allele with point mutations in both N-glycosylation sites is comparable to the cmeA mutants. Moreover, loss of CmeA glycosylation leads to reduced chicken colonization levels similar to the cmeA knock-out strain, while complementation fully restores colonization. Reconstitution of C. jejuni CmeABC into Escherichia coli together with the C. jejuni N-glycosylation pathway increases the EM minimum inhibitory concentration and decreases ethidium bromide accumulation when compared to cells lacking the pathway. Molecular dynamics simulations reveal that the protein structures of the glycosylated and non-glycosylated CmeA models do not vary from one another, and in vitro studies show no change in CmeA multimerization or peptidoglycan association. Therefore, we conclude that N-glycosylation has a broader influence on CmeABC function most likely playing a role in complex stability.
Collapse
Affiliation(s)
- Rajinder K Dubb
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Bernadette Beadle
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Michele R Richards
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Microbiology and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| |
Collapse
|
35
|
|
36
|
Zhang J, van der Veen S. Neisseria gonorrhoeae 23S rRNA A2059G mutation is the only determinant necessary for high-level azithromycin resistance and improves in vivo biological fitness. J Antimicrob Chemother 2020; 74:407-415. [PMID: 30376120 DOI: 10.1093/jac/dky438] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 09/28/2018] [Indexed: 12/13/2022] Open
Abstract
Objectives The global emergence of Neisseria gonorrhoeae isolates displaying high-level azithromycin resistance is a major concern for the currently recommended azithromycin/ceftriaxone dual therapy. N. gonorrhoeae high-level azithromycin resistance has been associated with an A2059G mutation in 23S rRNA. Here we investigated the specific contribution of this 23S rRNA A2059G mutation to high-level azithromycin resistance and its impact on biological fitness. Methods A2059G/G2059A alleles were specifically cloned into all four genomic copies of 23S rDNA of an azithromycin-susceptible isolate and a high-level azithromycin-resistant isolate. WT and mutant strains were subsequently investigated for azithromycin susceptibility using the agar dilution method. In addition, their biological fitness was studied by comparative liquid growth in the presence of hydrophobic and amphipathic compounds, by competition assays in a mouse vaginal tract infection model and by competition assays for invasion and intracellular survival. Results Azithromycin susceptibility analyses showed that the 23S rRNA A2059G mutation is the only genetic determinant required for N. gonorrhoeae to display the high-level azithromycin resistance phenotype. Further analysis of biological fitness showed that strains containing 2059G outcompeted isogenic strains containing 2059A for colonization in the mouse vaginal tract infection model and for invasion of HeLa cervical epithelial cells. Furthermore, the A2059G mutation enhanced growth in the presence of lithocholic acid or Triton X-100. Conclusions Our findings that the 23S rRNA A2059G mutation is sufficient for high-level azithromycin resistance and that this mutation generally enhanced the biological fitness of N. gonorrhoeae have important implications for the currently recommended treatment policies and antimicrobial stewardship programmes.
Collapse
Affiliation(s)
- Jianglin Zhang
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Stijn van der Veen
- Department of Microbiology and Parasitology, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China.,State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| |
Collapse
|
37
|
Colclough AL, Alav I, Whittle EE, Pugh HL, Darby EM, Legood SW, McNeil HE, Blair JM. RND efflux pumps in Gram-negative bacteria; regulation, structure and role in antibiotic resistance. Future Microbiol 2020; 15:143-157. [PMID: 32073314 DOI: 10.2217/fmb-2019-0235] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Rresistance-nodulation-division (RND) efflux pumps in Gram-negative bacteria remove multiple, structurally distinct classes of antimicrobials from inside bacterial cells therefore directly contributing to multidrug resistance. There is also emerging evidence that many other mechanisms of antibiotic resistance rely on the intrinsic resistance conferred by RND efflux. In addition to their role in antibiotic resistance, new information has become available about the natural role of RND pumps including their established role in virulence of many Gram-negative organisms. This review also discusses the recent advances in understanding the regulation and structure of RND efflux pumps.
Collapse
Affiliation(s)
- Abigail L Colclough
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Ilyas Alav
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Emily E Whittle
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Hannah L Pugh
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Elizabeth M Darby
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Simon W Legood
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Helen E McNeil
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Jessica Ma Blair
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| |
Collapse
|
38
|
Identification of a Neisseria gonorrhoeae Histone Deacetylase: Epigenetic Impact on Host Gene Expression. Pathogens 2020; 9:pathogens9020132. [PMID: 32085531 PMCID: PMC7168274 DOI: 10.3390/pathogens9020132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 12/19/2022] Open
Abstract
Epigenetic reprogramming in macrophages is termed trained innate immunity, which regulates immune tolerance and limits tissue damage during infection. Neisseria gonorrhoeae is a strict human pathogen that causes the sexually transmitted infection termed gonorrhea. Here, we report that this pathogen harbors a gene that encodes a histone deacetylase-like enzyme (Gc-HDAC) that shares high 3D-homology to human HDAC1, HDAC2 and HDAC8. A Gc-HDAC null mutant was constructed to determine the biologic significance of this gene. The results showed that WT gonococci reduced the expression of host defense peptides LL-37, HBD-1 and SLPI in macrophages when compared to its Gc-HDAC-deficient isogenic strain. The enrichment of epigenetic marks in histone tails control gene expression and are known to change during bacterial infections. To investigate whether gonococci exert epigenetic modifications on host chromatin, the enrichment of acetylated lysine 9 in histone 3 (H3K9ac) was investigated using the TLR-focused ChIP array system. The data showed that infection with WT gonococci led to higher H3K9ac enrichment at the promoters of pro-inflammatory mediators' genes, many TLRs, adaptor proteins and transcription factors, suggesting gene activation when compared to infection with the Gc-HDAC-deficient mutant. Taken together, the data suggest that gonococci can exert epigenetic modifications on host cells to modulate certain macrophage defense genes, leading to a maladaptive state of trained immunity.
Collapse
|
39
|
Multidrug Resistance in Neisseria gonorrhoeae: Identification of Functionally Important Residues in the MtrD Efflux Protein. mBio 2019; 10:mBio.02277-19. [PMID: 31744915 PMCID: PMC6867893 DOI: 10.1128/mbio.02277-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
With over 78 million new infections globally each year, gonorrhea remains a frustratingly common infection. Continuous development and spread of antimicrobial-resistant strains of Neisseria gonorrhoeae, the causative agent of gonorrhea, have posed a serious threat to public health. One of the mechanisms in N. gonorrhoeae involved in resistance to multiple drugs is performed by the MtrD multidrug resistance efflux pump. This study demonstrated that the MtrD pump has a broader substrate specificity than previously proposed and identified a cluster of residues important for drug binding and translocation. Additionally, a permeation pathway for the MtrD substrate progesterone actively moving through the protein was determined, revealing key interactions within the putative MtrD drug binding pockets. Identification of functionally important residues and substrate-protein interactions of the MtrD protein is crucial to develop future strategies for the treatment of multidrug-resistant gonorrhea. A key mechanism that Neisseria gonorrhoeae uses to achieve multidrug resistance is the expulsion of structurally different antimicrobials by the MtrD multidrug efflux protein. MtrD resembles the homologous Escherichia coli AcrB efflux protein with several common structural features, including an open cleft containing putative access and deep binding pockets proposed to interact with substrates. A highly discriminating N. gonorrhoeae strain, with the MtrD and NorM multidrug efflux pumps inactivated, was constructed and used to confirm and extend the substrate profile of MtrD to include 14 new compounds. The structural basis of substrate interactions with MtrD was interrogated by a combination of long-timescale molecular dynamics simulations and docking studies together with site-directed mutagenesis of selected residues. Of the MtrD mutants generated, only one (S611A) retained a wild-type (WT) resistance profile, while others (F136A, F176A, I605A, F610A, F612C, and F623C) showed reduced resistance to different antimicrobial compounds. Docking studies of eight MtrD substrates confirmed that many of the mutated residues play important nonspecific roles in binding to these substrates. Long-timescale molecular dynamics simulations of MtrD with its substrate progesterone showed the spontaneous binding of the substrate to the access pocket of the binding cleft and its subsequent penetration into the deep binding pocket, allowing the permeation pathway for a substrate through this important resistance mechanism to be identified. These findings provide a detailed picture of the interaction of MtrD with substrates that can be used as a basis for rational antibiotic and inhibitor design.
Collapse
|
40
|
Beggs GA, Zalucki YM, Brown NG, Rastegari S, Phillips RK, Palzkill T, Shafer WM, Kumaraswami M, Brennan RG. Structural, Biochemical, and In Vivo Characterization of MtrR-Mediated Resistance to Innate Antimicrobials by the Human Pathogen Neisseria gonorrhoeae. J Bacteriol 2019; 201:e00401-19. [PMID: 31331979 PMCID: PMC6755732 DOI: 10.1128/jb.00401-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 07/19/2019] [Indexed: 12/14/2022] Open
Abstract
Neisseria gonorrhoeae responds to host-derived antimicrobials by inducing the expression of the mtrCDE-encoded multidrug efflux pump, which expels microbicides, such as bile salts, fatty acids, and multiple extrinsically administered drugs, from the cell. In the absence of these cytotoxins, the TetR family member MtrR represses the mtrCDE genes. Although antimicrobial-dependent derepression of mtrCDE is clear, the physiological inducers of MtrR are unknown. Here, we report the crystal structure of an induced form of MtrR. In the binding pocket of MtrR, we observed electron density that we hypothesized was N-cyclohexyl-3-aminopropanesulfonic acid (CAPS), a component of the crystallization reagent. Using the MtrR-CAPS structure as an inducer-bound template, we hypothesized that bile salts, which bear significant chemical resemblance to CAPS, are physiologically relevant inducers. Indeed, characterization of MtrR-chenodeoxycholate and MtrR-taurodeoxycholate interactions, both in vitro and in vivo, revealed that these bile salts, but not glyocholate or taurocholate, bind MtrR tightly and can act as bona fide inducers. Furthermore, two residues, W136 and R176, were shown to be important in binding chenodeoxycholate but not taurodeoxycholate, suggesting different binding modes of the bile salts. These data provide insight into a crucial mechanism utilized by the pathogen to overcome innate human defenses.IMPORTANCENeisseria gonorrhoeae causes a significant disease burden worldwide, and a meteoric rise in its multidrug resistance has reduced the efficacy of antibiotics previously or currently approved for therapy of gonorrheal infections. The multidrug efflux pump MtrCDE transports multiple drugs and host-derived antimicrobials from the bacterial cell and confers survival advantage on the pathogen within the host. Transcription of the pump is repressed by MtrR but relieved by the cytosolic influx of antimicrobials. Here, we describe the structure of induced MtrR and use this structure to identify bile salts as physiological inducers of MtrR. These findings provide a mechanistic basis for antimicrobial sensing and gonococcal protection by MtrR through the derepression of mtrCDE expression after exposure to intrinsic and clinically applied antimicrobials.
Collapse
Affiliation(s)
- Grace A Beggs
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, USA
| | - Yaramah M Zalucki
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Nicholas Gene Brown
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Sheila Rastegari
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Hospital Research Institute, Houston, Texas, USA
- Department of Biochemistry and Molecular Biology, University of Texas, MD Anderson Cancer Center, Houston, Texas, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital System, Houston, Texas, USA
| | - Rebecca K Phillips
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Hospital Research Institute, Houston, Texas, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital System, Houston, Texas, USA
| | - Timothy Palzkill
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Microbial Pathogenesis, VA Medical Research Service, Veterans Affairs Medical Center, Decatur, Georgia, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Muthiah Kumaraswami
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Hospital Research Institute, Houston, Texas, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital System, Houston, Texas, USA
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
41
|
Pekmezovic M, Mogavero S, Naglik JR, Hube B. Host-Pathogen Interactions during Female Genital Tract Infections. Trends Microbiol 2019; 27:982-996. [PMID: 31451347 DOI: 10.1016/j.tim.2019.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/25/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022]
Abstract
Dysbiosis in the female genital tract (FGT) is characterized by the overgrowth of pathogenic bacterial, fungal, or protozoan members of the microbiota, leading to symptomatic or asymptomatic infections. In this review, we discuss recent advances in studies dealing with molecular mechanisms of pathogenicity factors of Gardnerella vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Neisseria gonorrhoeae, Streptococcus agalactiae, Chlamydia trachomatis, Trichomonas vaginalis, and Candida spp., as well as their interactions with the host and microbiota in the various niches of the FGT. Taking a holistic approach to identifying fundamental commonalities and differences during these infections could help us to better understand reproductive tract health and improve current prevention and treatment strategies.
Collapse
Affiliation(s)
- Marina Pekmezovic
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Selene Mogavero
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany
| | - Julian R Naglik
- Centre for Host-Microbiome Interactions, Faculty of Dental, Oral, and Craniofacial Sciences, King's College London, SE1 1UL, UK
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Hans Knoell Institute, Jena, Germany; Institute of Microbiology, Friedrich Schiller University, Jena, Germany. @leibniz-hki.de
| |
Collapse
|
42
|
Chen S, Connolly KL, Rouquette-Loughlin C, D'Andrea A, Jerse AE, Shafer WM. Could Dampening Expression of the Neisseria gonorrhoeae mtrCDE-Encoded Efflux Pump Be a Strategy To Preserve Currently or Resurrect Formerly Used Antibiotics To Treat Gonorrhea? mBio 2019; 10:e01576-19. [PMID: 31409679 PMCID: PMC6692510 DOI: 10.1128/mbio.01576-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/15/2019] [Indexed: 12/29/2022] Open
Abstract
Neisseria gonorrhoeae has developed resistance to every antibiotic introduced for treatment of gonorrhea since 1938, and concern now exists that gonorrheal infections may become refractory to all available antibiotics approved for therapy. The current recommended dual antibiotic treatment regimen of ceftriaxone (CRO) and azithromycin (AZM) is threatened with the emergence of gonococcal strains displaying resistance to one or both of these antibiotics. Non-beta-lactamase resistance to penicillin and third-generation cephalosporins, as well as low-level AZM resistance expressed by gonococci, requires overexpression of the mtrCDE-encoded efflux pump, which in wild-type (WT) strains is subject to transcriptional repression by MtrR. Since earlier studies showed that loss of MtrCDE renders gonococci hypersusceptible to beta-lactams and macrolides, we hypothesized that transcriptional dampening of mtrCDE would render an otherwise resistant strain susceptible to these antibiotics as assessed by antibiotic susceptibility testing and during experimental infection. In order to test this hypothesis, we ectopically expressed a WT copy of the mtrR gene, which encodes the repressor of the mtrCDE efflux pump operon, in N. gonorrhoeae strain H041, the first reported gonococcal strain to cause a third-generation-cephalosporin-resistant infection. We now report that MtrR production can repress the expression of mtrCDE, increase antimicrobial susceptibility in vitro, and enhance beta-lactam efficacy in eliminating gonococci as assessed in a female mouse model of lower genital tract infection. We propose that strategies that target the MtrCDE efflux pump should be considered to counteract the increasing problem of antibiotic-resistant gonococci.IMPORTANCE The emergence of gonococcal strains resistant to past or currently used antibiotics is a global public health concern, given the estimated 78 million infections that occur annually. The dearth of new antibiotics to treat gonorrhea demands that alternative curative strategies be considered to counteract antibiotic resistance expressed by gonococci. Herein, we show that decreased expression of a drug efflux pump that participates in gonococcal resistance to antibiotics can increase gonococcal susceptibility to beta-lactams and macrolides under laboratory conditions, as well as improve antibiotic-mediated clearance of gonococci from the genital tract of experimentally infected female mice.
Collapse
Affiliation(s)
- Shaochun Chen
- Department of Microbiology and Immunology and the Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, VA Medical Center, Decatur, Georgia, USA
- National Center for STD Control, Chinese Center for Disease Control and Prevention, Nanjing, China
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - Kristie L Connolly
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - Corinne Rouquette-Loughlin
- Department of Microbiology and Immunology and the Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, VA Medical Center, Decatur, Georgia, USA
| | - Alexander D'Andrea
- Department of Microbiology and Immunology and the Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, VA Medical Center, Decatur, Georgia, USA
| | - Ann E Jerse
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - William M Shafer
- Department of Microbiology and Immunology and the Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, VA Medical Center, Decatur, Georgia, USA
| |
Collapse
|
43
|
Baarda BI, Zielke RA, Le Van A, Jerse AE, Sikora AE. Neisseria gonorrhoeae MlaA influences gonococcal virulence and membrane vesicle production. PLoS Pathog 2019; 15:e1007385. [PMID: 30845186 PMCID: PMC6424457 DOI: 10.1371/journal.ppat.1007385] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/19/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023] Open
Abstract
The six-component maintenance of lipid asymmetry (Mla) system is responsible for retrograde transport of phospholipids, ensuring the barrier function of the Gram-negative cell envelope. Located within the outer membrane, MlaA (VacJ) acts as a channel to shuttle phospholipids from the outer leaflet. We identified Neisseria gonorrhoeae MlaA (ngo2121) during high-throughput proteomic mining for potential therapeutic targets against this medically important human pathogen. Our follow-up phenotypic microarrays revealed that lack of MlaA results in a complex sensitivity phenome. Herein we focused on MlaA function in cell envelope biogenesis and pathogenesis. We demonstrate the existence of two MlaA classes among 21 bacterial species, characterized by the presence or lack of a lipoprotein signal peptide. Purified truncated N. gonorrhoeae MlaA elicited antibodies that cross-reacted with a panel of different Neisseria. Little is known about MlaA expression; we provide the first evidence that MlaA levels increase in stationary phase and under anaerobiosis but decrease during iron starvation. Lack of MlaA resulted in higher cell counts during conditions mimicking different host niches; however, it also significantly decreased colony size. Antimicrobial peptides such as polymyxin B exacerbated the size difference while human defensin was detrimental to mutant viability. Consistent with the proposed role of MlaA in vesicle biogenesis, the ΔmlaA mutant released 1.7-fold more membrane vesicles. Comparative proteomics of cell envelopes and native membrane vesicles derived from ΔmlaA and wild type bacteria revealed enrichment of TadA–which recodes proteins through mRNA editing–as well as increased levels of adhesins and virulence factors. MlaA-deficient gonococci significantly outcompeted (up to 16-fold) wild-type bacteria in the murine lower genital tract, suggesting the growth advantage or increased expression of virulence factors afforded by inactivation of mlaA is advantageous in vivo. Based on these results, we propose N. gonorrhoeae restricts MlaA levels to modulate cell envelope homeostasis and fine-tune virulence. The Gram-negative outer membrane is a formidable barrier, primarily because of its asymmetric composition. A layer of lipopolysaccharide is exposed to the external environment and phospholipids are on the internal face of the outer membrane. MlaA is part of a bacterial system that prevents phospholipid accumulation within the lipopolysaccharide layer. If MlaA is removed, membrane asymmetry is disrupted and bacteria become more vulnerable to certain antimicrobials. Neisseria gonorrhoeae causes millions of infections worldwide annually. A growing number are resistant to available antibiotics. Improving our understanding of gonococcal pathogenicity and basic biological processes is required to facilitate the discovery of new weapons against gonorrhea. We investigated the role of MlaA in N. gonorrhoeae and found that when MlaA was absent, bacteria were more sensitive to antibiotics and human defensins. However, the mutant bacteria produced more membrane vesicles–packages of proteins wrapped in membrane material. Mutant vesicles and cell envelopes were enriched in proteins that contribute to disease. These alterations significantly increased mutant fitness during experimental infection of the female mouse genital tract. Our results provide new insights into the processes N. gonorrhoeae uses to fine-tune its ability to stay fit in the hostile environment of the genital tract.
Collapse
Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
| | - Adriana Le Van
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Ann E. Jerse
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon, United States of America
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America
- * E-mail:
| |
Collapse
|
44
|
El-Rami FE, Zielke RA, Wi T, Sikora AE, Unemo M. Quantitative Proteomics of the 2016 WHO Neisseria gonorrhoeae Reference Strains Surveys Vaccine Candidates and Antimicrobial Resistance Determinants. Mol Cell Proteomics 2019; 18:127-150. [PMID: 30352803 PMCID: PMC6317477 DOI: 10.1074/mcp.ra118.001125] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/23/2018] [Indexed: 12/27/2022] Open
Abstract
The sexually transmitted disease gonorrhea (causative agent: Neisseria gonorrhoeae) remains an urgent public health threat globally because of its reproductive health repercussions, high incidence, widespread antimicrobial resistance (AMR), and absence of a vaccine. To mine gonorrhea antigens and enhance our understanding of gonococcal AMR at the proteome level, we performed the first large-scale proteomic profiling of a diverse panel (n = 15) of gonococcal strains, including the 2016 World Health Organization (WHO) reference strains. These strains show all existing AMR profiles - established through phenotypic characterization and reference genome publication - and are intended for quality assurance in laboratory investigations. Herein, these isolates were subjected to subcellular fractionation and labeling with tandem mass tags coupled to mass spectrometry and multi-combinatorial bioinformatics. Our analyses detected 904 and 723 common proteins in cell envelope and cytoplasmic subproteomes, respectively. We identified nine novel gonorrhea vaccine candidates. Expression and conservation of new and previously selected antigens were investigated. In addition, established gonococcal AMR determinants were evaluated for the first time using quantitative proteomics. Six new proteins, WHO_F_00238, WHO_F_00635c, WHO_F_00745, WHO_F_01139, WHO_F_01144c, and WHO_F_01126, were differentially expressed in all strains, suggesting that they represent global proteomic AMR markers, indicate a predisposition toward developing or compensating gonococcal AMR, and/or act as new antimicrobial targets. Finally, phenotypic clustering based on the isolates' defined antibiograms and common differentially expressed proteins yielded seven matching clusters between established and proteome-derived AMR signatures. Together, our investigations provide a reference proteomics data bank for gonococcal vaccine and AMR research endeavors, which enables microbiological, clinical, or epidemiological projects and enhances the utility of the WHO reference strains.
Collapse
Affiliation(s)
- Fadi E El-Rami
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon
| | - Ryszard A Zielke
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon
| | - Teodora Wi
- §Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - Aleksandra E Sikora
- From the ‡Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, Oregon;; ¶Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, Oregon;.
| | - Magnus Unemo
- ‖World Health Organization Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections, Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
| |
Collapse
|
45
|
Baarda BI, Zielke RA, Nicholas RA, Sikora AE. PubMLST for Antigen Allele Mining to Inform Development of Gonorrhea Protein-Based Vaccines. Front Microbiol 2018; 9:2971. [PMID: 30581422 PMCID: PMC6292995 DOI: 10.3389/fmicb.2018.02971] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/19/2018] [Indexed: 02/02/2023] Open
Abstract
Neisseria gonorrhoeae (Ng) is a human-specific pathogen and the etiological agent of gonorrhea, a sexually transmitted infection with a significant global health burden. While often asymptomatic, untreated gonorrhea can lead to pelvic inflammatory disease, ectopic pregnancy, infertility, and increased transmission/acquisition of HIV. A protective gonorrhea vaccine may be the only way to control disease transmission in the future due to the inexorable development of antibiotic resistance. Subunit antigens are proven candidates for vaccine development due to their safety, cost-effectiveness, and rapid preparation. To inform protein-based gonorrhea vaccine design by including different antigen variants, herein we present bioinformatics mining of alleles and single nucleotide/amino acid polymorphisms using DNA/protein sequences of all Ng isolates deposited into the PubMLST database and MtrE and BamA as model antigens. We also present phylogenetic analyses that can be performed using sequence data to gain insights into the evolutionary relationships between the polymorphisms found among the population of isolates using a convenient tool: Molecular Evolutionary Genetics Analysis (MEGA) software. Finally, we perform antigen polymorphism mapping onto the MtrE and BamA structures. This methodology can be applied for rational vaccine design to increase vaccine coverage and cross-protection by heteroligand presentation achieved via inclusion of diverse antigen variants and is relevant to over 100 different species and genera deposited into the PubMLST family of databases.
Collapse
Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Robert A. Nicholas
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| |
Collapse
|
46
|
Baarda BI, Martinez FG, Sikora AE. Proteomics, Bioinformatics and Structure-Function Antigen Mining For Gonorrhea Vaccines. Front Immunol 2018; 9:2793. [PMID: 30564232 PMCID: PMC6288298 DOI: 10.3389/fimmu.2018.02793] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/13/2018] [Indexed: 12/12/2022] Open
Abstract
Expanding efforts to develop preventive gonorrhea vaccines is critical because of the serious health consequences combined with the prevalence and the dire possibility of untreatable gonorrhea. Reverse vaccinology, which includes genome and proteome mining, has proven successful in the discovery of vaccine candidates against many pathogenic bacteria. Here, we describe proteomic applications including comprehensive, quantitative proteomic platforms and immunoproteomics coupled with broad-ranging bioinformatics that have been applied for antigen mining to develop gonorrhea vaccine(s). We further focus on outlining the vaccine candidate decision tree, describe the structure-function of novel proteome-derived antigens as well as ways to gain insights into their roles in the cell envelope, and underscore new lessons learned about the fascinating biology of Neisseria gonorrhoeae.
Collapse
Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Fabian G. Martinez
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
| |
Collapse
|
47
|
Mechanistic Basis for Decreased Antimicrobial Susceptibility in a Clinical Isolate of Neisseria gonorrhoeae Possessing a Mosaic-Like mtr Efflux Pump Locus. mBio 2018; 9:mBio.02281-18. [PMID: 30482834 PMCID: PMC6282211 DOI: 10.1128/mbio.02281-18] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Historically, after introduction of an antibiotic for treatment of gonorrhea, strains of N. gonorrhoeae emerge that display clinical resistance due to spontaneous mutation or acquisition of resistance genes. Genetic exchange between members of the Neisseria genus occurring by transformation can cause significant changes in gonococci that impact the structure of an antibiotic target or expression of genes involved in resistance. The results presented here provide a framework for understanding how mosaic-like DNA sequences from commensal Neisseria that recombine within the gonococcal mtr efflux pump locus function to decrease bacterial susceptibility to antimicrobials, including antibiotics used in therapy of gonorrhea. Recent reports suggest that mosaic-like sequences within the mtr (multiple transferable resistance) efflux pump locus of Neisseria gonorrhoeae, likely originating from commensal Neisseria sp. by transformation, can increase the ability of gonococci to resist structurally diverse antimicrobials. Thus, acquisition of numerous nucleotide changes within the mtrR gene encoding the transcriptional repressor (MtrR) of the mtrCDE efflux pump-encoding operon or overlapping promoter region for both along with those that cause amino acid changes in the MtrD transporter protein were recently reported to decrease gonococcal susceptibility to numerous antimicrobials, including azithromycin (Azi) (C. B. Wadsworth, B. J. Arnold, M. R. A. Satar, and Y. H. Grad, mBio 9:e01419-18, 2018, https://doi.org/10.1128/mBio.01419-18). We performed detailed genetic and molecular studies to define the mechanistic basis for why such strains can exhibit decreased susceptibility to MtrCDE antimicrobial substrates, including Azi. We report that a strong cis-acting transcriptional impact of a single nucleotide change within the −35 hexamer of the mtrCDE promoter as well gain-of-function amino acid changes at the C-terminal region of MtrD can mechanistically account for the decreased antimicrobial susceptibility of gonococci with a mosaic-like mtr locus.
Collapse
|
48
|
Handing JW, Ragland SA, Bharathan UV, Criss AK. The MtrCDE Efflux Pump Contributes to Survival of Neisseria gonorrhoeae From Human Neutrophils and Their Antimicrobial Components. Front Microbiol 2018; 9:2688. [PMID: 30515136 PMCID: PMC6256084 DOI: 10.3389/fmicb.2018.02688] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/22/2018] [Indexed: 12/24/2022] Open
Abstract
The mucosal inflammatory response to Neisseria gonorrhoeae (Gc) is characterized by recruitment of neutrophils to the site of infection. Gc survives exposure to neutrophils by limiting the ability of neutrophils to make antimicrobial products and by expressing factors that defend against these products. The multiple transferable resistance (Mtr) system is a tripartite efflux pump, comprised of the inner membrane MtrD, the periplasmic attachment protein MtrC, and the outer membrane channel MtrE. Gc MtrCDE exports a diverse array of substrates, including certain detergents, dyes, antibiotics, and host-derived antimicrobial peptides. Here we report that MtrCDE contributes to the survival of Gc after exposure to adherent, chemokine-treated primary human neutrophils, specifically in the extracellular milieu. MtrCDE enhanced survival of Gc in neutrophil extracellular traps and in the supernatant from neutrophils that had undergone degranulation (granule exocytosis), a process that releases antimicrobial proteins into the extracellular milieu. The extent of degranulation was unaltered in neutrophils exposed to parental or mtr mutant Gc. MtrCDE expression contributed to Gc defense against some neutrophil-derived antimicrobial peptides but not others. These findings demonstrate that the Mtr system contributes to Gc survival after neutrophil challenge, a key feature of the host immune response to acute gonorrhea.
Collapse
Affiliation(s)
- Jonathan W Handing
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States
| | - Stephanie A Ragland
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States
| | - Urmila V Bharathan
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States
| | - Alison K Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, United States
| |
Collapse
|
49
|
Blanco P, Sanz-García F, Hernando-Amado S, Martínez JL, Alcalde-Rico M. The development of efflux pump inhibitors to treat Gram-negative infections. Expert Opin Drug Discov 2018; 13:919-931. [PMID: 30198793 DOI: 10.1080/17460441.2018.1514386] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION One of the possibilities for reducing the emergence and spread of antibiotic resistance is the use of anti-resistance compounds capable of resensitizing resistant microorganisms to current antimicrobials. For this purpose, multidrug efflux pumps, whose inhibition may increase bacterial susceptibility to several antibiotics, including macrolides to which Gram-negatives are considered intrinsically resistant, have emerged as suitable targets. Areas covered: In the current review, the authors discuss different mechanisms that can be exploited for inhibiting multidrug efflux pumps and describe the properties and the potential therapeutic value of already studied efflux pumps inhibitors. Although efforts have already been made to develop these inhibitors, there are currently no good candidates for treating infectious diseases. Consequently, the authors also discuss potential approaches for their development. Expert opinion: Classical anti-resistance drugs such as beta-lactamases inhibitors, while useful, are only purposeful for treating infections caused by beta-lactamase producers. However, inhibitors of multidrug efflux pumps, which are present on all organisms, can sensitize both susceptible and resistant bacteria to antibiotics belonging to several different structural families. Since some efflux pumps are involved in bacterial infections, their inhibition may also reduce the infectivity of Gram-negative bacterial pathogens.
Collapse
Affiliation(s)
- Paula Blanco
- a Department of Microbial Biotechnology , Centro Nacional de Biotecnología. CSIC , Madrid , Spain
| | - Fernando Sanz-García
- a Department of Microbial Biotechnology , Centro Nacional de Biotecnología. CSIC , Madrid , Spain
| | - Sara Hernando-Amado
- a Department of Microbial Biotechnology , Centro Nacional de Biotecnología. CSIC , Madrid , Spain
| | - José Luis Martínez
- a Department of Microbial Biotechnology , Centro Nacional de Biotecnología. CSIC , Madrid , Spain
| | - Manuel Alcalde-Rico
- a Department of Microbial Biotechnology , Centro Nacional de Biotecnología. CSIC , Madrid , Spain
| |
Collapse
|
50
|
Palmer A, Criss AK. Gonococcal Defenses against Antimicrobial Activities of Neutrophils. Trends Microbiol 2018; 26:1022-1034. [PMID: 30115561 DOI: 10.1016/j.tim.2018.07.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/09/2018] [Accepted: 07/20/2018] [Indexed: 01/05/2023]
Abstract
Neisseria gonorrhoeae initiates a strong local immune response that is characterized by copious recruitment of neutrophils to the site of infection. Neutrophils neutralize microbes by mechanisms that include phagocytosis, extracellular trap formation, production of reactive oxygen species, and the delivery of antimicrobial granular contents. However, neutrophils do not clear infection with N. gonorrhoeae. N. gonorrhoeae not only expresses factors that defend against neutrophil bactericidal components, but it also manipulates neutrophil production and release of these components. In this review, we highlight the numerous approaches used by N. gonorrhoeae to survive exposure to neutrophils both intracellularly and extracellularly. These approaches reflect the exquisite adaptation of N. gonorrhoeae to its obligate human host.
Collapse
Affiliation(s)
- Allison Palmer
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908-0734, USA
| | - Alison K Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, VA 22908-0734, USA.
| |
Collapse
|