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Rendon MA, So M. Zap the clap with DNA: a novel microbicide for preventing Neisseria gonorrhoeae infection. Antimicrob Agents Chemother 2024:e0079424. [PMID: 39150247 DOI: 10.1128/aac.00794-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 07/16/2024] [Indexed: 08/17/2024] Open
Abstract
Each year, Neisseria gonorrhoeae (Ngo) causes over 1.5 million new infections in the United States, and >87 million worldwide. The absence of a vaccine for preventing gonorrhea, the rapid emergence of multidrug-resistant and extremely drug-resistant Ngo strains, and the limited number of antibiotics available for treating gonorrhea underscore the importance of developing new modalities for addressing Ngo infection. Here, we describe DNA-based microbicides that kill Ngo but not commensals. Previously, we showed that Ngo is killed when it takes up differentially methylated DNA with homology to its genome. We exploited this Achilles heel to develop a new class of microbicides for preventing Ngo infection. These microbicides consist of DNA molecules with specific sequences and a methylation pattern different from Ngo DNA. These DNAs kill low-passage and antibiotic-resistant clinical isolates with high efficiency but leave commensals unharmed. Equally important, the DNAs are equally effective against Ngo whether they are in buffered media or personal lubricants. These findings illustrate the potential of this new class of practical, low-cost, self-administered DNA-based microbicides for preventing Ngo transmission during sexual intercourse.
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Affiliation(s)
- Maria A Rendon
- Department of Immunobiology, the BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Magdalene So
- Department of Immunobiology, the BIO5 Institute, University of Arizona, Tucson, Arizona, USA
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2
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Harris-Jones TN, Chan JM, Hackett KT, Weyand NJ, Schaub RE, Dillard JP. Peptidoglycan fragment release and NOD activation by commensal Neisseria species from humans and other animals. Infect Immun 2024; 92:e0000424. [PMID: 38563734 PMCID: PMC11075463 DOI: 10.1128/iai.00004-24] [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: 01/04/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
Neisseria gonorrhoeae, a human restricted pathogen, releases inflammatory peptidoglycan (PG) fragments that contribute to the pathophysiology of pelvic inflammatory disease. The genus Neisseria is also home to multiple species of human- or animal-associated Neisseria that form part of the normal microbiota. Here we characterized PG release from the human-associated nonpathogenic species Neisseria lactamica and Neisseria mucosa and animal-associated Neisseria from macaques and wild mice. An N. mucosa strain and an N. lactamica strain were found to release limited amounts of the proinflammatory monomeric PG fragments. However, a single amino acid difference in the PG fragment permease AmpG resulted in increased PG fragment release in a second N. lactamica strain examined. Neisseria isolated from macaques also showed substantial release of PG monomers. The mouse colonizer Neisseria musculi exhibited PG fragment release similar to that seen in N. gonorrhoeae with PG monomers being the predominant fragments released. All the human-associated species were able to stimulate NOD1 and NOD2 responses. N. musculi was a poor inducer of mouse NOD1, but ldcA mutation increased this response. The ability to genetically manipulate N. musculi and examine effects of different PG fragments or differing amounts of PG fragments during mouse colonization will lead to a better understanding of the roles of PG in Neisseria infections. Overall, we found that only some nonpathogenic Neisseria have diminished release of proinflammatory PG fragments, and there are differences even within a species as to types and amounts of PG fragments released.
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Affiliation(s)
- Tiffany N. Harris-Jones
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jia Mun Chan
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kathleen T. Hackett
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nathan J. Weyand
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Ryan E. Schaub
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joseph P. Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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3
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Garcia EM, Lenz JD, Schaub RE, Hackett KT, Salgado-Pabón W, Dillard JP. IL-17C is a driver of damaging inflammation during Neisseria gonorrhoeae infection of human Fallopian tube. Nat Commun 2024; 15:3756. [PMID: 38704381 PMCID: PMC11069574 DOI: 10.1038/s41467-024-48141-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 04/19/2024] [Indexed: 05/06/2024] Open
Abstract
The human pathogen Neisseria gonorrhoeae ascends into the upper female reproductive tract to cause damaging inflammation within the Fallopian tubes and pelvic inflammatory disease (PID), increasing the risk of infertility and ectopic pregnancy. The loss of ciliated cells from the epithelium is thought to be both a consequence of inflammation and a cause of adverse sequelae. However, the links between infection, inflammation, and ciliated cell extrusion remain unresolved. With the use of ex vivo cultures of human Fallopian tube paired with RNA sequencing we defined the tissue response to gonococcal challenge, identifying cytokine, chemokine, cell adhesion, and apoptosis related transcripts not previously recognized as potentiators of gonococcal PID. Unexpectedly, IL-17C was one of the most highly induced genes. Yet, this cytokine has no previous association with gonococcal infection nor pelvic inflammatory disease and thus it was selected for further characterization. We show that human Fallopian tubes express the IL-17C receptor on the epithelial surface and that treatment with purified IL-17C induces pro-inflammatory cytokine secretion in addition to sloughing of the epithelium and generalized tissue damage. These results demonstrate a previously unrecognized but critical role of IL-17C in the damaging inflammation induced by gonococci in a human explant model of PID.
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Affiliation(s)
- Erin M Garcia
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Jonathan D Lenz
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Ryan E Schaub
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Kathleen T Hackett
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Wilmara Salgado-Pabón
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA.
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4
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Vacca F, Cardamone D, Andreano E, Medini D, Rappuoli R, Sala C. Deep-learning image analysis for high-throughput screening of opsono-phagocytosis-promoting monoclonal antibodies against Neisseria gonorrhoeae. Sci Rep 2024; 14:4807. [PMID: 38413727 PMCID: PMC10899611 DOI: 10.1038/s41598-024-55606-4] [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: 01/09/2024] [Accepted: 02/26/2024] [Indexed: 02/29/2024] Open
Abstract
Antimicrobial resistance (AMR) is nowadays a global health concern as bacterial pathogens are increasingly developing resistance to antibiotics. Monoclonal antibodies (mAbs) represent a powerful tool for addressing AMR thanks to their high specificity for pathogenic bacteria which allows sparing the microbiota, kill bacteria through complement deposition, enhance phagocytosis or inhibit bacterial adhesion to epithelial cells. Here we describe a visual opsono-phagocytosis assay which relies on confocal microscopy to measure the impact of mAbs on phagocytosis of the bacterium Neisseria gonorrhoeae by macrophages. With respect to traditional CFU-based assays, generated images can be automatically analysed by convolutional neural networks. Our results demonstrate that confocal microscopy and deep learning-based analysis allow screening for phagocytosis-promoting mAbs against N. gonorrhoeae, even when mAbs are not purified and are expressed at low concentration. Ultimately, the flexibility of the staining protocol and of the deep-learning approach make the assay suitable for other bacterial species and cell lines where mAb activity needs to be investigated.
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Affiliation(s)
- Fabiola Vacca
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Dario Cardamone
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
- Data Science for Health Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
- University of Turin, Turin, Italy
| | - Emanuele Andreano
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | - Duccio Medini
- Data Science for Health Laboratory, Fondazione Toscana Life Sciences, Siena, Italy
| | | | - Claudia Sala
- Monoclonal Antibody Discovery Laboratory, Fondazione Toscana Life Sciences, Siena, Italy.
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5
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Xia L, Lu Q, Wang X, Jia C, Zhao Y, Wang G, Yang J, Zhang N, Min X, Huang J, Huang M. Characterization of protective immune responses against Neisseria gonorrhoeae induced by intranasal immunization with adhesion and penetration protein. Heliyon 2024; 10:e25733. [PMID: 38352762 PMCID: PMC10862674 DOI: 10.1016/j.heliyon.2024.e25733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/01/2024] [Accepted: 02/01/2024] [Indexed: 02/16/2024] Open
Abstract
Drug-resistant N. gonorrhoeae is an urgent threat to global public health, and vaccine development is the best long-term strategy for controlling gonorrhea. We have previously shown that adhesion and penetration protein (App) play a role in the adhesion, invasion, and reproductive tract colonization of N. gonorrhoeae. Here, we describe the immune response induced by intranasal immunization with passenger and translocator fragments of App. The recombinant App passenger and translocator fragments induced high titers of IgG and IgA antibodies in serum and vaginal washes. Antibodies produced by App passenger and the combination of passenger and translocator mediated the killing of N. gonorrhoeae via serum bactericidal activity and opsonophagocytic activity, whereas antisera from translocator-immunized groups had lower bactericidal activity and opsonophagocytic activity. The antisera of the App passenger and translocator, alone and in combination, inhibited the adhesion of N. gonorrhoeae to cervical epithelial cells in a concentration-dependent manner. Nasal immunization with App passenger and translocator fragments alone or in combination induced high levels of IgG1, IgG2a, and IgG2b antibodies and stimulated mouse splenocytes to secrete cytokines IFN-γ and IL-17A, suggesting that Th1 and Th17 cellular immune responses were activated. In vivo experiments have shown that immune App passenger and transporter fragments can accelerate the clearance of N. gonorrhoeae in the vagina of mice. These data suggest that the App protein is a promising N. gonorrhoeae vaccine antigen.
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Affiliation(s)
- Lingyin Xia
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Qin Lu
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Xiaosu Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Chengyi Jia
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Yujie Zhao
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Guangli Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jianru Yang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Ningqing Zhang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Xun Min
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jian Huang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
- School of Laboratory Medicine, Zunyi Medical University, Zunyi, Guizhou, China
| | - Meirong Huang
- Department of Blood Transfusion, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou, China
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6
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Geslewitz WE, Cardenas A, Zhou X, Zhang Y, Criss AK, Seifert HS. Development and implementation of a Type I-C CRISPR-based programmable repression system for Neisseria gonorrhoeae. mBio 2024; 15:e0302523. [PMID: 38126782 PMCID: PMC10865793 DOI: 10.1128/mbio.03025-23] [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: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) are prokaryotic adaptive immune systems regularly utilized as DNA-editing tools. While Neisseria gonorrhoeae does not have an endogenous CRISPR, the commensal species Neisseria lactamica encodes a functional Type I-C CRISPR-Cas system. We have established an isopropyl β-d-1-thiogalactopyranoside added (IPTG)-inducible, CRISPR interference (CRISPRi) platform based on the N. lactamica Type I-C CRISPR missing the Cas3 nuclease to allow locus-specific transcriptional repression. As proof of principle, we targeted a non-phase-variable version of the opaD gene. We show that CRISPRi can downregulate opaD gene and protein expression, resulting in bacterial inability to stimulate neutrophil oxidative responses and to bind to an N-terminal fragment of CEACAM1. Importantly, we used CRISPRi to effectively knockdown all the transcripts of all 11 opa genes using a five-spacer CRISPR array, allowing control of the entire phase-variable opa family in strain FA1090. We also report that repression is reversible following IPTG removal. Finally, we showed that the Type I-C CRISPRi system can conditionally reduce the expression of two essential genes. This CRISPRi system will allow the interrogation of every Gc gene, essential and non-essential, to study physiology and pathogenesis and aid in antimicrobial development.IMPORTANCEClustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems have proven instrumental in genetically manipulating many eukaryotic and prokaryotic organisms. Despite its usefulness, a CRISPR system had yet to be developed for use in Neisseria gonorrhoeae (Gc), a bacterium that is the main etiological agent of gonorrhea infection. Here, we developed a programmable and IPTG-inducible Type I-C CRISPR interference (CRISPRi) system derived from the commensal species Neisseria lactamica as a gene repression system in Gc. As opposed to generating genetic knockouts, the Type I-C CRISPRi system allows us to block transcription of specific genes without generating deletions in the DNA. We explored the properties of this system and found that a minimal spacer array is sufficient for gene repression while also facilitating efficient spacer reprogramming. Importantly, we also show that we can use CRISPRi to knockdown genes that are essential to Gc that cannot normally be knocked out under laboratory settings. Gc encodes ~800 essential genes, many of which have no predicted function. We predict that this Type I-C CRISPRi system can be used to help categorize gene functions and perhaps contribute to the development of novel therapeutics for gonorrhea.
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Affiliation(s)
- Wendy E. Geslewitz
- Department of Microbiology and Immunology, Northwestern University, Chicago, Illinois, USA
| | - Amaris Cardenas
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Xufei Zhou
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Yan Zhang
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - H Steven Seifert
- Department of Microbiology and Immunology, Northwestern University, Chicago, Illinois, USA
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7
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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.
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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.
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Pan J, Singh A, Hanning K, Hicks J, Williamson A. A role for the ATP-dependent DNA ligase lig E of Neisseria gonorrhoeae in biofilm formation. BMC Microbiol 2024; 24:29. [PMID: 38245708 PMCID: PMC10799422 DOI: 10.1186/s12866-024-03193-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 01/10/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND The ATP-dependent DNA ligase Lig E is present as an accessory DNA ligase in numerous proteobacterial genomes, including many disease-causing species. Here we have constructed a genomic Lig E knock-out in the obligate human pathogen Neisseria gonorrhoeae and characterised its growth and infection phenotype. RESULTS This demonstrates that N. gonorrhoeae Lig E is a non-essential gene and its deletion does not cause defects in replication or survival of DNA-damaging stressors. Knock-out strains were partially defective in biofilm formation on an artificial surface as well as adhesion to epithelial cells. In addition to in vivo characterisation, we have recombinantly expressed and assayed N. gonorrhoeae Lig E and determined the crystal structure of the enzyme-adenylate engaged with DNA substrate in an open non-catalytic conformation. CONCLUSIONS These findings, coupled with the predicted extracellular/ periplasmic location of Lig E indicates a role in extracellular DNA joining as well as providing insight into the binding dynamics of these minimal DNA ligases.
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Affiliation(s)
- Jolyn Pan
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Avi Singh
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Kyrin Hanning
- School of Science, University of Waikato, Hamilton, New Zealand
| | - Joanna Hicks
- School of Health, University of Waikato, Hamilton, New Zealand
| | - Adele Williamson
- School of Science, University of Waikato, Hamilton, New Zealand.
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9
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Rhodes KA, Rendón MA, Ma MC, Agellon A, Johnson AC, So M. Type IV pilus retraction is required for Neisseria musculi colonization and persistence in a natural mouse model of infection. mBio 2024; 15:e0279223. [PMID: 38084997 PMCID: PMC10790696 DOI: 10.1128/mbio.02792-23] [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: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 01/17/2024] Open
Abstract
IMPORTANCE We describe the importance of Type IV pilus retraction to colonization and persistence by a mouse commensal Neisseria, N. musculi, in its native host. Our findings have implications for the role of Tfp retraction in mediating interactions of human-adapted pathogenic and commensal Neisseria with their human host due to the relatedness of these species.
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Affiliation(s)
- Katherine A. Rhodes
- Immunobiology Department, University of Arizona College of Medicine, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - María A. Rendón
- Immunobiology Department, University of Arizona College of Medicine, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Man Cheong Ma
- Immunobiology Department, University of Arizona College of Medicine, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Al Agellon
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, USA
| | - Andrew C.E. Johnson
- Immunobiology Department, University of Arizona College of Medicine, Tucson, Arizona, USA
| | - Magdalene So
- Immunobiology Department, University of Arizona College of Medicine, Tucson, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
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10
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Harris-Jones TN, Pérez Medina KM, Hackett KT, Schave MA, Klimowicz AK, Schaub RE, Dillard JP. Mutation of mltG increases peptidoglycan fragment release, cell size, and antibiotic susceptibility in Neisseria gonorrhoeae. J Bacteriol 2023; 205:e0027723. [PMID: 38038461 PMCID: PMC10729727 DOI: 10.1128/jb.00277-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Neisseria gonorrhoeae is unusual in that the bacteria release larger amounts of cell wall material as they grow as compared to related bacteria, and the released cell wall fragments induce inflammation that leads to tissue damage in infected people. The study of MltG revealed the importance of this enzyme for controlling cell wall growth, cell wall fragment production, and bacterial cell size and suggests a role for MltG in a cell wall synthesis and degradation complex. The increased antibiotic sensitivities of mltG mutants suggest that an antimicrobial drug inhibiting MltG would be useful in combination therapy to restore the sensitivity of the bacteria to cell wall targeting antibiotics to which the bacteria are currently resistant.
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Affiliation(s)
- Tiffany N. Harris-Jones
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Krizia M. Pérez Medina
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kathleen T. Hackett
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Melanie A. Schave
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Amy K. Klimowicz
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Ryan E. Schaub
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Joseph P. Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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11
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Płaczkiewicz J, Gieczewska K, Musiałowski M, Adamczyk-Popławska M, Bącal P, Kwiatek A. Availability of iron ions impacts physicochemical properties and proteome of outer membrane vesicles released by Neisseria gonorrhoeae. Sci Rep 2023; 13:18733. [PMID: 37907530 PMCID: PMC10618220 DOI: 10.1038/s41598-023-45498-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/20/2023] [Indexed: 11/02/2023] Open
Abstract
Outer membrane vesicles (OMVs) are bilayer structures released by bacteria for various purposes, e.g., response to environmental factors, bacterial communication, and interactions with host cells. One of the environmental variables bacteria need to react is the amount and availability of iron, a crucial element for bacteria biology. We have investigated the impact of the iron amount and availability on OMV secretion by pathogenic Neisseria gonorrhoeae, which, depending on the infection site, challenges different iron availability. N. gonorrhoeae releases OMVs in iron starvation and repletion growth environments. However, OMVs differed in physicochemical features and proteome according to iron amount and availability during the bacteria growth, as was analyzed by Liquid Chromatography-Tandem Mass Spectrometry, Infrared spectroscopy with a Fourier transform infrared spectrometer, and Atomic Force Microscopy. OMVs from iron starvation and repletion conditions had a higher variation in size, different flexibility, and different membrane protein and lipid components than OMVs isolated from control growth conditions. These OMVs also varied qualitatively and quantitatively in their total proteome composition and contained proteins unique for iron starvation and repletion conditions. Thus, the modulation of OMVs' properties seems to be a part of N. gonorrhoeae adaptation to surroundings and indicates a new direction of antigonococcal proceeding.
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Affiliation(s)
- Jagoda Płaczkiewicz
- Department of Molecular Virology, Institute of Microbiology, Faculty of Biology, University of Warsaw, 02-096, Warsaw, Poland
- International Centre for Translational Eye Research, Ophthalmic Biology Group, Warsaw, Poland, 01-230
| | - Katarzyna Gieczewska
- Department of Plant Anatomy and Cytology, Institute of Experimental Biology and Plant Biotechnology, Faculty of Biology, University of Warsaw, Warsaw, Poland, 02-096
| | - Marcin Musiałowski
- Department of Geomicrobiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland, 02-096
| | - Monika Adamczyk-Popławska
- Department of Molecular Virology, Institute of Microbiology, Faculty of Biology, University of Warsaw, 02-096, Warsaw, Poland
| | - Paweł Bącal
- Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland, 00-818
| | - Agnieszka Kwiatek
- Department of Molecular Virology, Institute of Microbiology, Faculty of Biology, University of Warsaw, 02-096, Warsaw, Poland.
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Adamczyk-Popławska M, Golec P, Piekarowicz A, Kwiatek A. The potential for bacteriophages and prophage elements in fighting and preventing the gonorrhea. Crit Rev Microbiol 2023:1-16. [PMID: 37897236 DOI: 10.1080/1040841x.2023.2274849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 10/11/2023] [Indexed: 10/30/2023]
Abstract
Bacteriophages are the most numerous entities on earth and are found everywhere their bacterial hosts live. As natural bacteria killers, phages are extensively investigated as a potential cure for bacterial infections. Neisseria gonorrhoeae (the gonococcus) is the etiologic agent of a sexually transmitted disease: gonorrhea. The rapid increase of resistance of N. gonorrhoeae to antibiotics urges scientists to look for alternative treatments to combat gonococcal infections. Phage therapy has not been tested as an anti-gonococcal therapy so far. To date, no lytic phage has been discovered against N. gonorrhoeae. Nevertheless, gonococcal genomes contain both dsDNA and ssDNA prophages, and viral particle induction has been documented. In this review, we consider literature data about the attempts of hunting for a bacteriophage specific for gonococci - the gonophage. We also discuss the potential application of prophage elements in the fight against N. gonorrhoeae. Temperate phages may be useful in preventing and treating gonorrhea as a scaffold for anti-gonococcal vaccine development and as a source of lytic enzymes with anti-gonococcal activity.
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Affiliation(s)
- Monika Adamczyk-Popławska
- Department of Molecular Virology, Faculty of Biology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | - Piotr Golec
- Department of Molecular Virology, Faculty of Biology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | - Andrzej Piekarowicz
- Department of Molecular Virology, Faculty of Biology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
| | - Agnieszka Kwiatek
- Department of Molecular Virology, Faculty of Biology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
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Holley CL, Dhulipala V, Maurakis SA, Greenawalt AN, Read TD, Cornelissen CN, Shafer WM. Transcriptional activation of ompA in Neisseria gonorrhoeae mediated by the XRE family member protein NceR. mBio 2023; 14:e0124423. [PMID: 37387605 PMCID: PMC10470515 DOI: 10.1128/mbio.01244-23] [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: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 07/01/2023] Open
Abstract
Increasing antibiotic resistance of Neisseria gonorrhoeae, the causative agent of gonorrhea, is a growing global concern that has renewed vaccine development efforts. The gonococcal OmpA protein was previously identified as a vaccine candidate due to its surface exposure, conservation, stable expression, and involvement in host-cell interactions. We previously demonstrated that the transcription of ompA can be activated by the MisR/MisS two-component system. Interestingly, earlier work suggested that the availability of free iron also influences ompA expression, which we confirmed in this study. In the present study, we found that iron regulation of ompA was independent of MisR and searched for additional regulators. A DNA pull-down assay with the ompA promoter from gonococcal lysates obtained from bacteria grown in the presence or absence of iron identified an XRE (Xenobiotic Response Element) family member protein encoded by NGO1982. We found that an NGO1982 null mutant of N. gonorrhoeae strain FA19 displayed a reduced level of ompA expression compared to the wild-type (WT) parent strain. Given this regulation, and the capacity of this XRE-like protein to regulate a gene involved in peptidoglycan biosynthesis (ltgA), along with its presence in other Neisseria sp., we termed the NGO1982-encoded protein as NceR (Neisseria cell envelope regulator). Critically, results from DNA-binding studies indicated that NceR regulates ompA through a direct mechanism. Thus, ompA expression is subject to both iron-dependent (NceR) and -independent (MisR/MisS) pathways. Hence, levels of the vaccine antigen candidate OmpA in circulating gonococcal strains could be influenced by transcriptional regulatory systems and the availability of iron. IMPORTANCE Herein, we report that the gene encoding a conserved gonococcal surface-exposed vaccine candidate (OmpA) is activated by a heretofore undescribed XRE family transcription factor, which we term NceR. We report that NceR regulation of ompA expression in N. gonorrhoeae is mediated by an iron-dependent mechanism, while the previously described MisR regulatory system is iron-independent. Our study highlights the importance of defining the complexity of coordinated genetic and physiologic systems that regulate genes encoding vaccine candidates to better understand their availability during infection.
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Affiliation(s)
- Concerta L. Holley
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Vijaya Dhulipala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Stavaros A. Maurakis
- Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia, USA
| | | | - Timothy D. Read
- Department of Medicine (Division of Infectious Diseases), Emory University School of Medicine, Atlanta, Georgia, USA
- The Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - William M. Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
- Department of Medicine (Division of Infectious Diseases), Emory University School of Medicine, Atlanta, Georgia, USA
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center, Decatur, Georgia, USA
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14
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Potter AD, Baiocco CM, Papin JA, Criss AK. Transcriptome-guided metabolic network analysis reveals rearrangements of carbon flux distribution in Neisseria gonorrhoeae during neutrophil co-culture. mSystems 2023; 8:e0126522. [PMID: 37387581 PMCID: PMC10470122 DOI: 10.1128/msystems.01265-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 05/19/2023] [Indexed: 07/01/2023] Open
Abstract
The ability of bacterial pathogens to metabolically adapt to the environmental conditions of their hosts is critical to both colonization and invasive disease. Infection with Neisseria gonorrhoeae (the gonococcus, Gc) is characterized by the influx of neutrophils [polymorphonuclear leukocytes (PMNs)], which fail to clear the bacteria and make antimicrobial products that can exacerbate tissue damage. The inability of the human host to clear Gc infection is particularly concerning in light of the emergence of strains that are resistant to all clinically recommended antibiotics. Bacterial metabolism represents a promising target for the development of new therapeutics against Gc. Here, we generated a curated genome-scale metabolic network reconstruction (GENRE) of Gc strain FA1090. This GENRE links genetic information to metabolic phenotypes and predicts Gc biomass synthesis and energy consumption. We validated this model with published data and in new results reported here. Contextualization of this model using the transcriptional profile of Gc exposed to PMNs revealed substantial rearrangements of Gc central metabolism and induction of Gc nutrient acquisition strategies for alternate carbon source use. These features enhanced the growth of Gc in the presence of neutrophils. From these results, we conclude that the metabolic interplay between Gc and PMNs helps define infection outcomes. The use of transcriptional profiling and metabolic modeling to reveal new mechanisms by which Gc persists in the presence of PMNs uncovers unique aspects of metabolism in this fastidious bacterium, which could be targeted to block infection and thereby reduce the burden of gonorrhea in the human population. IMPORTANCE The World Health Organization designated Gc as a high-priority pathogen for research and development of new antimicrobials. Bacterial metabolism is a promising target for new antimicrobials, as metabolic enzymes are widely conserved among bacterial strains and are critical for nutrient acquisition and survival within the human host. Here we used genome-scale metabolic modeling to characterize the core metabolic pathways of this fastidious bacterium and to uncover the pathways used by Gc during culture with primary human immune cells. These analyses revealed that Gc relies on different metabolic pathways during co-culture with human neutrophils than in rich media. Conditionally essential genes emerging from these analyses were validated experimentally. These results show that metabolic adaptation in the context of innate immunity is important to Gc pathogenesis. Identifying the metabolic pathways used by Gc during infection can highlight new therapeutic targets for drug-resistant gonorrhea.
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Affiliation(s)
- Aimee D. Potter
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Christopher M. Baiocco
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - Jason A. Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
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15
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Seow VY, Tsygelnytska O, Biais N. Multisite transformation in Neisseria gonorrhoeae: insights on transformations mechanisms and new genetic modification protocols. Front Microbiol 2023; 14:1178128. [PMID: 37408636 PMCID: PMC10319059 DOI: 10.3389/fmicb.2023.1178128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/31/2023] [Indexed: 07/07/2023] Open
Abstract
Natural transformation, or the uptake of naked DNA from the external milieu by bacteria, holds a unique place in the history of biology. This is both the beginning of the realization of the correct chemical nature of genes and the first technical step to the molecular biology revolution that sees us today able to modify genomes almost at will. Yet the mechanistic understanding of bacterial transformation still presents many blind spots and many bacterial systems lag behind power horse model systems like Escherichia coli in terms of ease of genetic modification. Using Neisseria gonorrhoeae as a model system and using transformation with multiple DNA molecules, we tackle in this paper both some aspects of the mechanistic nature of bacterial transformation and the presentation of new molecular biology techniques for this organism. We show that similarly to what has been demonstrated in other naturally competent bacteria, Neisseria gonorrhoeae can incorporate, at the same time, different DNA molecules modifying DNA at different loci within its genome. In particular, co-transformation of a DNA molecule bearing an antibiotic selection cassette and another non-selected DNA piece can lead to the integration of both molecules in the genome while selecting only through the selective cassette at percentages above 70%. We also show that successive selections with two selection markers at the same genetic locus can drastically reduce the number of genetic markers needed to do multisite genetic modifications in Neisseria gonorrhoeae. Despite public health interest heightened with the recent rise in antibiotic resistance, the causative agent of gonorrhea still does not possess a plethora of molecular techniques. This paper will extend the techniques available to the Neisseria community while providing some insights into the mechanisms behind bacterial transformation in Neisseria gonorrhoeae. We are providing a suite of new techniques to quickly obtain modifications of genes and genomes in the Neisserial naturally competent bacteria.
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Affiliation(s)
- Vui Yin Seow
- Brooklyn College of the City University of New York, Brooklyn, NY, United States
- The Graduate Center of the City University of New York, New York, NY, United States
- Laboratoire Jean Perrin, UMR8237, Sorbonne Université, Paris, France
| | - Olga Tsygelnytska
- Brooklyn College of the City University of New York, Brooklyn, NY, United States
| | - Nicolas Biais
- Brooklyn College of the City University of New York, Brooklyn, NY, United States
- The Graduate Center of the City University of New York, New York, NY, United States
- Laboratoire Jean Perrin, UMR8237, Sorbonne Université, Paris, France
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16
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Dave N, Albiheyri RS, Wanford JJ, Green LR, Oldfield NJ, Turner DPJ, Martinez-Pomares L, Bayliss CD. Variable disruption of epithelial monolayers by Neisseria meningitidis carriage isolates of the hypervirulent MenW cc11 and MenY cc23 lineages. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36821361 DOI: 10.1099/mic.0.001305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Colonization of mucosal tissues by Neisseria meningitidis requires adhesion mediated by the type IV pilus and multiple outer-membrane proteins. Penetration of the mucosa and invasion of epithelial cells are thought to contribute to host persistence and invasive disease. Using Calu-3 cell monolayers grown at an air-liquid interface, we examined adhesion, invasion and monolayer disruption by carriage isolates of two clonal complexes of N. meningitidis. Carriage isolates of both the serogroup Y cc23 and the hypervirulent serogroup W cc11 lineages exhibited high levels of cellular adhesion, and a variable disruption phenotype across independent isolates. Inactivation of the gene encoding the main pilus sub-unit in multiple cc11 isolates abrogated both adhesive capacity and ability to disrupt epithelial monolayers. Contrastingly, inactivation of the phase-variable opa or nadA genes reduced adhesion and invasion, but not disruption of monolayer integrity. Adherence of tissue-disruptive meningococci correlated with loss of staining for the tight junction protein, occludin. Intriguingly, in a pilus-negative strain background, we observed compensatory ON switching of opa genes, which facilitated continued adhesion. We conclude that disruption of epithelial monolayers occurs in multiple meningococcal lineages but can vary during carriage and is intimately linked to pilus-mediated adhesion.
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Affiliation(s)
- Neelam Dave
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | - Raed S Albiheyri
- School of Life Sciences, University of Nottingham, Nottingham, UK.,Present address: Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Joseph J Wanford
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.,Present address: Department of Infectious Disease, King's College, London, UK
| | - Luke R Green
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK.,Present address: Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Neil J Oldfield
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - David P J Turner
- School of Life Sciences, University of Nottingham, Nottingham, UK
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17
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CanB is a metabolic mediator of antibiotic resistance in Neisseria gonorrhoeae. Nat Microbiol 2023; 8:28-39. [PMID: 36604513 DOI: 10.1038/s41564-022-01282-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 10/28/2022] [Indexed: 01/07/2023]
Abstract
The evolution of the obligate human pathogen Neisseria gonorrhoeae has been shaped by selective pressures from diverse host niche environments and antibiotics. The varying prevalence of antibiotic resistance across N. gonorrhoeae lineages suggests that underlying metabolic differences may influence the likelihood of acquisition of specific resistance mutations. We hypothesized that the requirement for supplemental CO2, present in approximately half of isolates, reflects one such example of metabolic variation. Here, using a genome-wide association study and experimental investigations, we show that CO2 dependence is attributable to a single substitution in a β-carbonic anhydrase, CanB. CanB19E is necessary and sufficient for growth in the absence of CO2, and the hypomorphic CanB19G variant confers CO2 dependence. Furthermore, ciprofloxacin resistance is correlated with CanB19G in clinical isolates, and the presence of CanB19G increases the likelihood of acquisition of ciprofloxacin resistance. Together, our results suggest that metabolic variation has affected the acquisition of fluoroquinolone resistance.
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18
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Mazumder L, Hasan MR, Fatema K, Islam MZ, Tamanna SK. Structural and Functional Annotation and Molecular Docking Analysis of a Hypothetical Protein from Neisseria gonorrhoeae: An In-Silico Approach. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4302625. [PMID: 36105928 PMCID: PMC9467719 DOI: 10.1155/2022/4302625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/17/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022]
Abstract
Background Worldwide, Neisseria gonorrhoeae-related sexually transmitted infections (STIs) continue to be of significant public health concern. This obligate-human pathogen has developed a number of defenses against both innate and adaptive immune responses during infection, some of which are mediated by the pathogen's proteins. Hence, the uncharacterized proteins of N. gonorrhoeae can be annotated to get insight into the unique functions of this organism related to its pathogenicity and to find a more efficient therapeutic target. Methods In this study, a hypothetical protein (HP) of N. gonorrhoeae was chosen for analysis and an in-silico approach was used to explore various properties such as physicochemical characteristics, subcellular localization, secondary structure, 3D structures, and functional annotation of that HP. Finally, a molecular docking analysis was performed to design an epitope-based vaccine against that HP. Results This study has identified the potential role of the chosen HP of N. gonorrhoeae in plasmid transfer, cell cycle control, cell division, and chromosome partitioning. Acidic nature, thermal stability, cytoplasmic localization of the protein, and some of its other physicochemical properties have also been identified through this study. Molecular docking analysis has demonstrated that one of the T cell epitopes of the protein has a significant binding affinity with the human leukocyte antigen HLA-B∗15 : 01. Conclusions The in-silico characterization of this protein will help us understand molecular mechanism of action of N. gonorrhoeae and get an insight into novel therapeutic identification processes. This research will, therefore, enhance our knowledge to find new medications to tackle this potential threat to humankind.
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Affiliation(s)
- Lincon Mazumder
- Department of Microbiology, Jagannath University, Dhaka 1100, Bangladesh
| | - Md. Rakibul Hasan
- Department of Microbiology, Jagannath University, Dhaka 1100, Bangladesh
| | - Kanij Fatema
- Department of Microbiology, Jagannath University, Dhaka 1100, Bangladesh
| | - Md. Zahirul Islam
- Department of Microbiology, Jagannath University, Dhaka 1100, Bangladesh
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19
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Kandinov I, Gryadunov D, Vinokurova A, Antonova O, Kubanov A, Solomka V, Shagabieva J, Deryabin D, Shaskolskiy B. In vitro Susceptibility to β-Lactam Antibiotics and Viability of Neisseria gonorrhoeae Strains Producing Plasmid-Mediated Broad- and Extended-Spectrum β-Lactamases. Front Microbiol 2022; 13:896607. [PMID: 35794921 PMCID: PMC9251354 DOI: 10.3389/fmicb.2022.896607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/01/2022] [Indexed: 11/17/2022] Open
Abstract
Neisseria gonorrhoeae plasmids can mediate high-level antimicrobial resistance. The emergence of clinical isolates producing plasmid β-lactamases that can hydrolyze cephalosporins, the mainstay treatment for gonorrhea, may be a serious threat. In this work, N. gonorrhoeae strains producing plasmid-mediated broad- and extended-spectrum β-lactamases (ESBLs) were obtained in vitro, and their viability and β-lactam antibiotic susceptibility were studied. Artificial pblaTEM-1 and pblaTEM-20 plasmids were constructed by site-directed mutagenesis from a pblaTEM-135 plasmid isolated from a clinical isolate. Minimum inhibitory concentration (MIC) values for a series of β-lactam antibiotics, including benzylpenicillin, ampicillin, cefuroxime, ceftriaxone, cefixime, cefotaxime, cefepime, meropenem, imipenem, and doripenem, were determined. The N. gonorrhoeae strain carrying the pblaTEM-20 plasmid exhibited a high level of resistance to penicillins and second–fourth-generation cephalosporins (MIC ≥2 mg/L) but not to carbapenems (MIC ≤0.008 mg/L). However, this strain stopped growing after 6 h of culture. The reduction in viability was not associated with loss of the plasmid but can be explained by the presence of the plasmid itself, which requires additional reproduction costs, and to the expression of ESBLs, which can affect the structure of the peptidoglycan layer in the cell membrane. Cell growth was mathematically modeled using the generalized Verhulst equation, and the reduced viability of the plasmid-carrying strains compared to the non-plasmid-carrying strains was confirmed. The cell death kinetics of N. gonorrhoeae strains without the pblaTEM-20 plasmid in the presence of ceftriaxone can be described by a modified Chick–Watson law. The corresponding kinetics of the N. gonorrhoeae strain carrying the pblaTEM-20 plasmid reflected several processes: the hydrolysis of ceftriaxone by the TEM-20 β-lactamase and the growth and gradual death of cells. The demonstrated reduction in the viability of N. gonorrhoeae strains carrying the pblaTEM-20 plasmid probably explains the absence of clinical isolates of ESBL-producing N. gonorrhoeae.
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Affiliation(s)
- Ilya Kandinov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- *Correspondence: Ilya Kandinov,
| | - Dmitry Gryadunov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexandra Vinokurova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Olga Antonova
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Alexey Kubanov
- State Research Center of Dermatovenerology and Cosmetology, Russian Ministry of Health, Moscow, Russia
| | - Victoria Solomka
- State Research Center of Dermatovenerology and Cosmetology, Russian Ministry of Health, Moscow, Russia
| | - Julia Shagabieva
- State Research Center of Dermatovenerology and Cosmetology, Russian Ministry of Health, Moscow, Russia
| | - Dmitry Deryabin
- State Research Center of Dermatovenerology and Cosmetology, Russian Ministry of Health, Moscow, Russia
| | - Boris Shaskolskiy
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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20
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Jones RA, Yee WX, Mader K, Tang CM, Cehovin A. Markerless gene editing in Neisseria gonorrhoeae. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35763318 DOI: 10.1099/mic.0.001201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Neisseria gonorrhoeae, the gonococcus, is a pathogen of major public health concern, but sophisticated approaches to gene manipulation are limited for this species. For example, there are few methods for generating markerless mutations, which allow the generation of precise point mutations and deletions without introducing additional DNA sequence. Markerless mutations are central to studying pathogenesis, the spread of antimicrobial resistance (AMR) and for vaccine development. Here we describe the use of galK as a counter-selectable marker that can be used for markerless mutagenesis in N. gonorrhoeae. galK encodes galactokinase, an enzyme that metabolizes galactose in bacteria that can utilize it as a sole carbon source. GalK can also phosphorylate a galactose analogue, 2-deoxy-galactose (2-DOG), into a toxic, non-metabolisable intermediate, 2-deoxy-galactose-1-phosphate. We utilized this property of GalK to develop a markerless approach for mutagenesis in N. gonorrhoeae. We successfully deleted both chromosomally and plasmid-encoded genes, that are important for gonococcal vaccine development and studies of AMR spread. We designed a positive-negative selection cassette, based on an antibiotic resistance marker and galK, that efficiently rendered N. gonorrhoeae susceptible to growth on 2-DOG. We then adapted the galK-based counter-selection and the use of 2-DOG for markerless mutagenesis, and applied biochemical and phenotypic analyses to confirm the absence of target genes. We show that our markerless mutagenesis method for N. gonorrhoeae has a high success rate, and should be a valuable gene editing tool in the future.
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Affiliation(s)
- Rebekah A Jones
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Wearn Xin Yee
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Kahlio Mader
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
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21
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Huynh MS, Hooda Y, Li YR, Jagielnicki M, Lai CCL, Moraes TF. Reconstitution of surface lipoprotein translocation through the slam translocon. eLife 2022; 11:72822. [PMID: 35475756 PMCID: PMC9090332 DOI: 10.7554/elife.72822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
Surface lipoproteins (SLPs) are peripherally attached to the outer leaflet of the outer membrane in many Gram-negative bacteria, playing significant roles in nutrient acquisition and immune evasion in the host. While the factors that are involved in the synthesis and delivery of SLPs in the inner membrane are well characterized, the molecular machinery required for the movement of SLPs to the surface are still not fully elucidated. In this study, we investigated the translocation of a SLP TbpB through a Slam1-dependent pathway. Using purified components, we developed an in vitro translocation assay where unfolded TbpB is transported through Slam1-containing proteoliposomes, confirming Slam1 as an outer membrane translocon. While looking to identify factors to increase translocation efficiency, we discovered the periplasmic chaperone Skp interacted with TbpB in the periplasm of Escherichia coli. The presence of Skp was found to increase the translocation efficiency of TbpB in the reconstituted translocation assays. A knockout of Skp in Neisseria meningitidis revealed that Skp is essential for functional translocation of TbpB to the bacterial surface. Taken together, we propose a pathway for surface destined lipoproteins, where Skp acts as a holdase for Slam-mediated TbpB translocation across the outer membrane.
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Affiliation(s)
- Minh Sang Huynh
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Yogesh Hooda
- MRC Laboratory of Molecular Biology, University of Cambridge, Cambridge, United Kingdom
| | - Yuzi Raina Li
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | | | | | - Trevor F Moraes
- Department of Biochemistry, University of Toronto, Toronto, Canada
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22
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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: 4] [Impact Index Per Article: 2.0] [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.
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23
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Alternative Pathways to Ciprofloxacin Resistance in Neisseria gonorrhoeae: An In Vitro Study of the WHO-P and WHO-F Reference Strains. Antibiotics (Basel) 2022; 11:antibiotics11040499. [PMID: 35453249 PMCID: PMC9026730 DOI: 10.3390/antibiotics11040499] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 01/21/2023] Open
Abstract
Emerging resistance to ceftriaxone and azithromycin has led to renewed interest in using ciprofloxacin to treat Neisseria gonorrhoeae. This could lead to the rapid emergence and spread of ciprofloxacin resistance. Previous studies investigating the emergence of fluoroquinolone resistance have been limited to a single strain of N. gonorrhoeae. It is unknown if different genetic backgrounds affect the evolution of fluoroquinolone resistance in N. gonorrhoeae, as has been shown in other bacterial species. This study evaluated the molecular pathways leading to ciprofloxacin resistance in two reference strains of N.gonorrhoeae-WHO-F and WHO-P. Three clones of each of the two strains of N.gonorrhoeae were evolved in the presence of ciprofloxacin, and isolates from different time points were whole-genome sequenced. We found evidence of strain-specific differences in the emergence of ciprofloxacin resistance. Two out of three clones from WHO-P followed the canonical pathway to resistance proceeding via substitutions in GyrA-S91F, GyrA-D95N and ParC. None of the three WHO-F clones followed this pathway. In addition, mutations in gyrB, uvrA and rne frequently occurred in WHO-F clones, whereas mutations in yhgF, porB and potA occurred in WHO-P.
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Chan JM, Hackett KT, Woodhams KL, Schaub RE, Dillard JP. The AmiC/NlpD Pathway Dominates Peptidoglycan Breakdown in Neisseria meningitidis and Affects Cell Separation, NOD1 Agonist Production, and Infection. Infect Immun 2022; 90:e0048521. [PMID: 35225652 PMCID: PMC8929373 DOI: 10.1128/iai.00485-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022] Open
Abstract
The human-restricted pathogen Neisseria meningitidis, which is best known for causing invasive meningococcal disease, has a nonpathogenic lifestyle as an asymptomatic colonizer of the human naso- and oropharyngeal space. N. meningitidis releases small peptidoglycan (PG) fragments during growth. It was demonstrated previously that N. meningitidis releases low levels of tripeptide PG monomer, which is an inflammatory molecule recognized by the human intracellular innate immune receptor NOD1. In the present study, we demonstrated that N. meningitidis released more PG-derived peptides than PG monomers. Using a reporter cell line overexpressing human NOD1, we showed that N. meningitidis activates NOD1 using PG-derived peptides. The generation of such peptides required the presence of the periplasmic N-acetylmuramyl-l-alanine amidase AmiC and the outer membrane lipoprotein NlpD. AmiC and NlpD were found to function in cell separation, and mutation of either amiC or nlpD resulted in large clumps of unseparated N. meningitidis cells instead of the characteristic diplococci. Using stochastic optical reconstruction microscopy, we demonstrated that FLAG epitope-tagged NlpD localized to the septum, while similarly tagged AmiC was found at the septum in some diplococci but was distributed around the cell in most cases. In a human whole-blood infection assay, an nlpD mutant was severely attenuated and showed particular sensitivity to complement. Thus, in N. meningitidis, the cell separation proteins AmiC and NlpD are necessary for NOD1 stimulation and survival during infection of human blood.
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Affiliation(s)
- Jia Mun Chan
- University of Wisconsin—Madison, Department of Medical Microbiology and Immunology, School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Kathleen T. Hackett
- University of Wisconsin—Madison, Department of Medical Microbiology and Immunology, School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Katelynn L. Woodhams
- University of Wisconsin—Madison, Department of Medical Microbiology and Immunology, School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Ryan E. Schaub
- University of Wisconsin—Madison, Department of Medical Microbiology and Immunology, School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Joseph P. Dillard
- University of Wisconsin—Madison, Department of Medical Microbiology and Immunology, School of Medicine and Public Health, Madison, Wisconsin, USA
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Gonococcal Clinical Strains Bearing a Common gdhR Single Nucleotide Polymorphism That Results in Enhanced Expression of the Virulence Gene lctP Frequently Possess a mtrR Promoter Mutation That Decreases Antibiotic Susceptibility. mBio 2022; 13:e0027622. [PMID: 35258329 PMCID: PMC9040798 DOI: 10.1128/mbio.00276-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
GdhR is a transcriptional repressor of the virulence factor gene lctP, which encodes a unique l-lactate permease that has been linked to pathogenesis of Neisseria gonorrhoeae, and loss of gdhR can confer increased fitness of gonococci in a female mouse model of lower genital tract infection. In this work, we identified a single nucleotide polymorphism (SNP) in gdhR, which is often present in both recent and historical gonococcal clinical strains and results in a proline (P)-to-serine (S) change at amino acid position 6 (P6S) of GdhR. This mutation (gdhR6) was found to reduce GdhR transcriptional repression at lctP in gonococcal strains containing the mutant protein compared to wild-type GdhR. By using purified recombinant proteins and in vitro DNA-binding and cross-linking experiments, we found that gdhR6 impairs the DNA-binding activity of GdhR at lctP without an apparent effect on protein oligomerization. By analyzing a panel of U.S. (from 2017 to 2018) and Danish (1928 to 2013) clinical isolates, we observed a statistical association between gdhR6 and the previously described adenine deletion in the promoter of mtrR (mtrR-P A-del), encoding the repressor (MtrR) of the mtrCDE operon that encodes the MtrCDE multidrug efflux pump that can export antibiotics, host antimicrobials, and biocides. The frequent association of gdhR6 with the mtrR promoter mutation in these clinical isolates suggests that it has persisted in this genetic background to enhance lctP expression, thereby promoting virulence.
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Kraus-Römer S, Wielert I, Rathmann I, Grossbach J, Maier B. External Stresses Affect Gonococcal Type 4 Pilus Dynamics. Front Microbiol 2022; 13:839711. [PMID: 35283813 PMCID: PMC8914258 DOI: 10.3389/fmicb.2022.839711] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Bacterial type 4 pili (T4P) are extracellular polymers that serve both as adhesins and molecular motors. Functionally, they are involved in adhesion, colony formation, twitching motility, and horizontal gene transfer. T4P of the human pathogen Neisseria gonorrhoeae have been shown to enhance survivability under treatment with antibiotics or hydrogen peroxide. However, little is known about the effect of external stresses on T4P production and motor properties. Here, we address this question by directly visualizing gonococcal T4P dynamics. We show that in the absence of stress gonococci produce T4P at a remarkably high rate of ∼200 T4P min–1. T4P retraction succeeds elongation without detectable time delay. Treatment with azithromycin or ceftriaxone reduces the T4P production rate. RNA sequencing results suggest that reduced piliation is caused by combined downregulation of the complexes required for T4P extrusion from the cell envelope and cellular energy depletion. Various other stresses including inhibitors of cell wall synthesis and DNA replication, as well as hydrogen peroxide and lactic acid, inhibit T4P production. Moreover, hydrogen peroxide and acidic pH strongly affect pilus length and motor function. In summary, we show that gonococcal T4P are highly dynamic and diverse external stresses reduce piliation despite the protective effect of T4P against some of these stresses.
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Affiliation(s)
| | - Isabelle Wielert
- Institute for Biological Physics, University of Cologne, Cologne, Germany
| | - Isabel Rathmann
- Institute for Biological Physics, University of Cologne, Cologne, Germany
| | - Jan Grossbach
- Faculty of Mathematics and Natural Sciences, CECAD, University of Cologne, Cologne, Germany
| | - Berenike Maier
- Institute for Biological Physics, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, Cologne, Germany
- *Correspondence: Berenike Maier,
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Adherence enables Neisseria gonorrhoeae to overcome zinc limitation imposed by nutritional immunity proteins. Infect Immun 2022; 90:e0000922. [PMID: 35156850 DOI: 10.1128/iai.00009-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neisseria gonorrhoeae (Gc) must overcome limitation of metals such as zinc to colonize mucosal surfaces in its obligate human host. While the zinc-binding nutritional immunity proteins calprotectin (S100A8/A9) and psoriasin (S100A7) are abundant in human cervicovaginal lavage fluid, Gc possesses TonB-dependent transporters TdfH and TdfJ that bind and extract zinc from the human version of these proteins, respectively. Here we investigated the contribution of zinc acquisition to Gc infection of epithelial cells of the female genital tract. We found that TdfH and TdfJ were dispensable for survival of strain FA1090 Gc that were associated with Ect1 human immortalized epithelial cells, when zinc was limited by calprotectin and psoriasin. In contrast, suspension-grown bacteria declined in viability under the same conditions. Exposure to murine calprotectin, which Gc cannot use as a zinc source, similarly reduced survival of suspension-grown Gc, but not Ect1-associated Gc. We ruled out epithelial cells as a contributor to the enhanced growth of cell-associated Gc under zinc limitation. Instead, we found that attachment to glass was sufficient to enhance bacterial growth when zinc was sequestered. We compared the transcriptional profiles of WT Gc adherent to glass coverslips or in suspension, when zinc was sequestered with murine calprotectin or provided in excess, from which we identified open reading frames that were increased by zinc sequestration in adherent Gc. One of these, ZnuA, was necessary but not sufficient for survival of Gc under zinc-limiting conditions. These results show that adherence protects Gc from zinc-dependent growth restriction by host nutritional immunity proteins.
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A Unique Sequence Is Essential for Efficient Multidrug Efflux Function of the MtrD Protein of Neisseria gonorrhoeae. mBio 2021; 12:e0167521. [PMID: 34465021 PMCID: PMC8406276 DOI: 10.1128/mbio.01675-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antimicrobial resistance in Neisseria gonorrhoeae has reached an alarming level, severely impacting the effective treatment of gonorrhea. Belonging to the resistance-nodulation-cell division (RND) superfamily of efflux transporters, the MtrD membrane protein of N. gonorrhoeae provides resistance to a broad range of antimicrobial compounds. A unique feature of MtrD is an 11-residue sequence (from N917 to P927 [N917-P927]) that connects transmembrane helices (TMS) 9 and 10; this sequence is not present in homologous RND proteins. This study explores the structural and functional roles of the N917-P927 region by means of mutant analysis and molecular dynamics simulations. We show that N917-P927 plays a key role in modulating substrate access to the binding cleft and influences the overall orientation of the protein within the inner membrane necessary for optimal functioning. Removal of N917-P927 significantly reduced MtrD-mediated resistance to a range of antimicrobials and mutations of three single amino acids impacted MtrD-mediated multidrug resistance. Furthermore, molecular dynamics simulations showed deletion of N917-P927 in MtrD may dysregulate access of the substrate to the binding cleft and closure of the substrate-binding pocket during the transport cycle. These findings indicate that N917-P927 is a key region for interacting with the inner membrane, conceivably influencing substrate capture from the membrane-periplasm interface and thus is essential for full multidrug resistance capacity of MtrD. IMPORTANCE The historical sexually transmitted infection gonorrhea continues to be a major public health concern with an estimated global annual incidence of 86.9 million cases. N. gonorrhoeae has been identified by the World Health Organization as one of the 12 antimicrobial-resistant bacterial species that poses the greatest risk to human health. As the major efflux pump in gonococci, the MtrD transporter contributes to the cell envelope barrier in this organism and pumps antimicrobials from the periplasm and inner membrane, resulting in resistance. This study demonstrates that a unique region of the MtrD protein that connects TMS 9 and TMS 10 forms a structure that may interact with the inner membrane positioning TMS 9 and stabilizing the protein facilitating substrate capture from the inner membrane-periplasm interface. Analysis of mutants of this region identified that it was essential for MtrD-mediated multidrug resistance. Characterization of the structure and function of this unique local region of MtrD has implications for drug efflux mechanisms used by related proteins and is important knowledge for development of antibiotics that bypass efflux.
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Beggs GA, Ayala JC, Kavanaugh LG, Read T, Hooks G, Schumacher M, Shafer W, Brennan R. Structures of Neisseria gonorrhoeae MtrR-operator complexes reveal molecular mechanisms of DNA recognition and antibiotic resistance-conferring clinical mutations. Nucleic Acids Res 2021; 49:4155-4170. [PMID: 33784401 PMCID: PMC8053128 DOI: 10.1093/nar/gkab213] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/08/2021] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
Mutations within the mtrR gene are commonly found amongst multidrug resistant clinical isolates of Neisseria gonorrhoeae, which has been labelled a superbug by the Centers for Disease Control and Prevention. These mutations appear to contribute to antibiotic resistance by interfering with the ability of MtrR to bind to and repress expression of its target genes, which include the mtrCDE multidrug efflux transporter genes and the rpoH oxidative stress response sigma factor gene. However, the DNA-recognition mechanism of MtrR and the consensus sequence within these operators to which MtrR binds has remained unknown. In this work, we report the crystal structures of MtrR bound to the mtrCDE and rpoH operators, which reveal a conserved, but degenerate, DNA consensus binding site 5'-MCRTRCRN4YGYAYGK-3'. We complement our structural data with a comprehensive mutational analysis of key MtrR-DNA contacts to reveal their importance for MtrR-DNA binding both in vitro and in vivo. Furthermore, we model and generate common clinical mutations of MtrR to provide plausible biochemical explanations for the contribution of these mutations to multidrug resistance in N. gonorrhoeae. Collectively, our findings unveil key biological mechanisms underlying the global stress responses of N. gonorrhoeae.
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Affiliation(s)
- Grace A Beggs
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Julio C Ayala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Logan G Kavanaugh
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Timothy D Read
- Department of Medicine, and the Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Grace M Hooks
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Maria A Schumacher
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
- Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA 30322, USA
- Laboratories of Bacterial Pathogenesis, VA Medical Center, Decatur, GA 30033, USA
| | - Richard G Brennan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
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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: 54] [Impact Index Per Article: 13.5] [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.
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Ma KC, Mortimer TD, Hicks AL, Wheeler NE, Sánchez-Busó L, Golparian D, Taiaroa G, Rubin DHF, Wang Y, Williamson DA, Unemo M, Harris SR, Grad YH. Adaptation to the cervical environment is associated with increased antibiotic susceptibility in Neisseria gonorrhoeae. Nat Commun 2020; 11:4126. [PMID: 32807804 PMCID: PMC7431566 DOI: 10.1038/s41467-020-17980-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 07/24/2020] [Indexed: 01/01/2023] Open
Abstract
Neisseria gonorrhoeae is an urgent public health threat due to rapidly increasing incidence and antibiotic resistance. In contrast with the trend of increasing resistance, clinical isolates that have reverted to susceptibility regularly appear, prompting questions about which pressures compete with antibiotics to shape gonococcal evolution. Here, we used genome-wide association to identify loss-of-function (LOF) mutations in the efflux pump mtrCDE operon as a mechanism of increased antibiotic susceptibility and demonstrate that these mutations are overrepresented in cervical relative to urethral isolates. This enrichment holds true for LOF mutations in another efflux pump, farAB, and in urogenitally-adapted versus typical N. meningitidis, providing evidence for a model in which expression of these pumps in the female urogenital tract incurs a fitness cost for pathogenic Neisseria. Overall, our findings highlight the impact of integrating microbial population genomics with host metadata and demonstrate how host environmental pressures can lead to increased antibiotic susceptibility.
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Affiliation(s)
- Kevin C Ma
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Tatum D Mortimer
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Allison L Hicks
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Nicole E Wheeler
- Centre for Genomic Pathogen Surveillance, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Leonor Sánchez-Busó
- Centre for Genomic Pathogen Surveillance, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Daniel Golparian
- WHO Collaborating Centre for Gonorrhoea and other STIs, Swedish Reference Laboratory for STIs, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - George Taiaroa
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Daniel H F Rubin
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Yi Wang
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Deborah A Williamson
- Microbiological Diagnostic Unit Public Health Laboratory, Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and other STIs, Swedish Reference Laboratory for STIs, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Simon R Harris
- Microbiotica Ltd, Biodata Innovation Centre, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Yonatan H Grad
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Division of Infectious Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
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Thapa E, Knauss HM, Colvin BA, Fischer BA, Weyand NJ. Persistence Dynamics of Antimicrobial-Resistant Neisseria in the Pharynx of Rhesus Macaques. Antimicrob Agents Chemother 2020; 64:e02232-19. [PMID: 32423958 PMCID: PMC7526842 DOI: 10.1128/aac.02232-19] [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: 11/06/2019] [Accepted: 05/13/2020] [Indexed: 11/20/2022] Open
Abstract
Pharyngeal infections by Neisseria gonorrhoeae are often asymptomatic, making them difficult to treat. However, in vivo animal modeling of human pharyngeal infections by pathogenic Neisseria species is challenging due to numerous host tropism barriers. We have relied on rhesus macaques to investigate pharyngeal persistence of naturally occurring Neisseria species in response to antibiotics. These species include Neisseria mucosa, Neisseria oralis, and a species unique to macaques. Four animals previously treated intramuscularly with the fluoroquinolone enrofloxacin for 2 weeks were monitored for persistence of their preexisting Neisseria populations for a period of 10 weeks. Enrofloxacin exposure did not eliminate preexisting flora from two of the four animals. Characterization of a collection of macaque Neisseria isolates supported the hypothesis that pharyngeal persistence was linked to reduced enrofloxacin susceptibility conferred by mutations in either gyrA or parC Interestingly, we observed a change in neisserial population dynamics for several weeks following enrofloxacin exposure. Enrofloxacin appeared to promote competition between strains for dominance in the pharyngeal niche. Specifically, following enrofloxacin treatment, strains bearing single gyrA mutations and low MICs persisted long-term. In contrast, strains with both gyrA and parC mutations and high MICs became culturally undetectable, consistent with the hypothesis that they were less fit. Our study has provided insight into pharyngeal persistence dynamics of Neisseria species bearing fluoroquinolone resistance determinants. The rhesus macaque provides a valuable host animal that may be used in the future to simulate treatment failures associated with the presence of antimicrobial-resistant Neisseria spp. in the human pharynx.
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Affiliation(s)
- Eliza Thapa
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Hanna M Knauss
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Benjamin A Colvin
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | | | - Nathan J Weyand
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
- The Infectious and Tropical Disease Institute, Ohio University, Athens, Ohio, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, Ohio, USA
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Huang J, Zhang Q, Chen J, Zhang T, Chen Z, Chen Z, Yang J, Wang Y, Min Z, Huang M, Min X. Neisseria gonorrhoeae NGO2105 Is an Autotransporter Protein Involved in Adhesion to Human Cervical Epithelial Cells and in vivo Colonization. Front Microbiol 2020; 11:1395. [PMID: 32670242 PMCID: PMC7330057 DOI: 10.3389/fmicb.2020.01395] [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: 02/28/2020] [Accepted: 05/29/2020] [Indexed: 11/13/2022] Open
Abstract
Autotransporters are important virulence factors in the outer membrane of gram-negative bacteria. Although several autotransporters have been identified in Neisseria meningitidis, only IgA1 protease has been identified in Neisseria gonorrhoeae. A sequence analysis showed a marked difference in the distribution of autotransporters between the two strains. It has been speculated that only two autotransporters, the IgA1 protease and the NGO2105 protein, might be encoded by N. gonorrhoeae. Here, we describe the identification of NGO2105, a new autotransporter in N. gonorrhoeae. A sequence alignment showed that NGO2105 is highly similar to the adhesion and penetration protein (App) in N. meningitidis. We found that NGO2105 is exported to the outer membrane, cleaved and released into the culture supernatant by endogenous serine protease activity in N. gonorrhoeae and E. coli. The site-directed mutagenesis of S267A in the predicted enzyme catalytic triad abolished autoproteolytic cleavage to allow secretion. The NGO2105 β-barrel shows the ability to translocate the heterologous Hbp passenger domain. NGO2105 is involved in gonococcal adherence to and invasion into human cervical epithelial cells. Furthermore, antibodies raised against NGO2105 are able to block gonococcal adherence to human cervical epithelial cells. The Δngo2105 mutant and anti-NGO2105 antiserum significantly attenuated the colonization of N. gonorrhoeae in mice. Collectively, our results suggest that the newly identified serine protease autotransporter NGO2105 represents a novel virulence factor of gonococcus and a potential vaccine target.
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Affiliation(s)
- Jian Huang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Qing Zhang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Jie Chen
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Tao Zhang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Zehui Chen
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Zuyi Chen
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Jianru Yang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Yongxiang Wang
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Zongsu Min
- Zunyi Maternal and Child Health Hospital, Zunyi, China
| | - Meirong Huang
- Department of Blood Transfusion, Affiliated Hospital of Zunyi Medical University, Zunyi, China
| | - Xun Min
- Department of Laboratory Medicine, Affiliated Hospital of Zunyi Medical University, Zunyi, China
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Singh R, Perera SR, Katselis GS, Chumala P, Martin I, Kusalik A, Mitzel KM, Dillon JAR. A β-lactamase-producing plasmid from Neisseria gonorrhoeae carrying a unique 6 bp deletion in blaTEM-1 encoding a truncated 24 kDa TEM-1 penicillinase that hydrolyses ampicillin slowly. J Antimicrob Chemother 2020; 74:2904-2912. [PMID: 31335939 DOI: 10.1093/jac/dkz306] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/13/2019] [Accepted: 06/16/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Seven structurally related β-lactamase-producing plasmids have been characterized in penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates. We characterized a variant (i.e. pJRD20, Canada type) of the Africa-type (pJD5) plasmid isolated from N. gonorrhoeae strain 8903. OBJECTIVES To compare the DNA sequence of pJRD20 with that of pJD5 and pJD4 (Asia-type) and their TEM-1 β-lactamases. METHODS N. gonorrhoeae 8903 was identified as part of the Gonococcal Antimicrobial Surveillance Program in Canada. β-Lactamase production was assessed using nitrocefin. MICs were determined by agar dilution and Etest methods (CLSI). The DNA sequences of pJRD20, pJD5 and pJD4 were assembled and annotated. The structure of TEM-1 and its penicillin-binding properties were determined by in silico molecular modelling and docking. TEM-1 proteins were characterized by western blot, mass spectrometry and ampicillin hydrolysis assays. RESULTS N. gonorrhoeae 8903 exhibited intermediate susceptibility to penicillin with slow β-lactamase activity (i.e. 35 min to hydrolyse nitrocefin). Except for a novel 6 bp deletion starting at the G of the ATG start codon of blaTEM-1, the DNA sequence of pJRD20 was identical to that of pJD5. The TEM-1 β-lactamase produced by pJRD20 is 24 kDa and hydrolyses ampicillin only after several hours. CONCLUSIONS This unusual PPNG isolate might have been characterized as a non-PPNG owing to its low MIC of penicillin and its very slow hydrolysis of nitrocefin. Given the unusual nature of its TEM-1 β-lactamase, laboratories might consider extending the duration of nitrocefin hydrolysis assays.
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Affiliation(s)
- Reema Singh
- Department of Biochemistry, Microbiology and Immunology, 2D01 Health Science Building, 107 Wiggins Road, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada
| | - Sumudu R Perera
- Department of Biochemistry, Microbiology and Immunology, 2D01 Health Science Building, 107 Wiggins Road, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada
| | - George S Katselis
- Department of Medicine, Division of the Canadian Centre for Health and Safety in Agriculture, 1246 Health Sciences E-Wing, 104 Clinic Place, University of Saskatchewan, Saskatoon, SK, Canada
| | - Paulos Chumala
- Department of Medicine, Division of the Canadian Centre for Health and Safety in Agriculture, 1246 Health Sciences E-Wing, 104 Clinic Place, University of Saskatchewan, Saskatoon, SK, Canada
| | - Irene Martin
- National Microbiology Laboratory, Streptococcus and STI Unit, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, MB, Canada
| | - Anthony Kusalik
- Department of Computer Science, 176 Thorvaldson Building, 110 Science Place, University of Saskatchewan, Saskatoon, SK, Canada
| | - Kristen M Mitzel
- Department of Biochemistry, Microbiology and Immunology, 2D01 Health Science Building, 107 Wiggins Road, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jo-Anne R Dillon
- Department of Biochemistry, Microbiology and Immunology, 2D01 Health Science Building, 107 Wiggins Road, University of Saskatchewan, Saskatoon, SK, Canada.,Vaccine and Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Road, Saskatoon, SK, Canada
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35
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Holley CL, Ayala JC, Shafer WM. Transcriptional control of the gonococcal ompA gene by the MisR/MisS two-component regulatory system. Sci Rep 2020; 10:9425. [PMID: 32523077 PMCID: PMC7286886 DOI: 10.1038/s41598-020-66382-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/20/2020] [Indexed: 11/11/2022] Open
Abstract
Neisseria gonorrhoeae, the causative agent of gonorrhea, is an exclusive human pathogen whose growing antibiotic resistance is causing worldwide concern. The increasing rise of antibiotic resistance expressed by gonococci highlights the need to find alternative approaches to current gonorrhea treatment such as vaccine development or novel therapeutics. The gonococcal OmpA protein was previously identified as a potential vaccine candidate due to its conservation and stable expression amongst strains of Neisseria gonorrhoeae. However, factors that might modulate levels of OmpA and therefore potential vaccine efficacy are unknown. Earlier work indicated that ompA is part of the MisR/MisS regulon and suggested that it was a MisR-activated gene. Herein, we confirmed MisR/MisS regulation of ompA and report that the MisR response regulator can bind upstream of the ompA translational start codon. Further, we describe the contribution of a DNA sequence upstream of the ompA promoter that is critical for MisR activation of ompA transcription. Our results provide a framework for understanding the transcription of gonococcal ompA through a regulatory system known to be important for survival of gonococci during experimental infection.
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Affiliation(s)
- Concerta L Holley
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, 30032, USA
| | - Julio C Ayala
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, 30032, USA
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, 30032, USA.
- The Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, 30032, USA.
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center, Decatur, GA, 30039, USA.
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Werner LM, Palmer A, Smirnov A, Belcher Dufrisne M, Columbus L, Criss AK. Imaging Flow Cytometry Analysis of CEACAM Binding to Opa-Expressing Neisseria gonorrhoeae. Cytometry A 2020; 97:1081-1089. [PMID: 32484607 DOI: 10.1002/cyto.a.24037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/04/2020] [Accepted: 04/03/2020] [Indexed: 12/31/2022]
Abstract
Human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are a family of receptors that mediate intercellular interactions. Pathogenic bacteria have ligands that bind CEACAMs on human cells. Neisseria gonorrhoeae (Gc) encodes numerous unique outer membrane opacity-associated (Opa) proteins that are ligands for one or more CEACAMs. CEACAMs that are expressed on epithelial cells facilitate Gc colonization, while those expressed on neutrophils affect phagocytosis and consequent intracellular survival of Gc. Since Opa protein expression is phase-variable, variations in receptor tropism affect how individual bacteria within a population interact with host cells. Here we report the development of a rapid, quantitative method for collecting and analyzing fluorescence intensity data from thousands of cells in a population using imaging flow cytometry to detect N-CEACAM bound to the surface of Opa-expressing Gc. We use this method to confirm previous findings regarding Opa-CEACAM interactions and to examine the receptor-ligand interactions of Gc expressing other Opa proteins, as well as for other N-CEACAM proteins. © 2020 International Society for Advancement of Cytometry.
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Affiliation(s)
- Lacie M Werner
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22903, USA
| | - Allison Palmer
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22903, USA
| | - Asya Smirnov
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22903, USA
| | | | - Linda Columbus
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, 22903, USA
| | - Alison K Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22903, USA
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Lactobacillus crispatus and its enolase and glutamine synthetase influence interactions between Neisseria gonorrhoeae and human epithelial cells. J Microbiol 2020; 58:405-414. [PMID: 32279277 DOI: 10.1007/s12275-020-9505-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/30/2020] [Accepted: 01/30/2020] [Indexed: 01/06/2023]
Abstract
Neisseria gonorrhoeae, an obligatory human pathogen causes the sexually transmitted disease gonorrhea, which remains a global health problem. N. gonorrhoeae primarily infects the mucosa of the genitourinary tract, which in women, is colonized by natural microbiota, dominated by Lactobacillus spp., that protect human cells against pathogens. In this study, we demonstrated that precolonization of human epithelial cells with Lactobacillus crispatus, one of the most prevalent bacteria in the female urogenital tract, or preincubation with the L. crispatus enolase or glutamine synthetase impairs the adhesion and invasiveness of N. gonorrhoeae toward epithelial cells, two crucial steps in gonococcal pathogenesis. Furthermore, decreased expression of genes encoding the proinflam-matory cytokines, TNFα and CCL20, which are secreted as a consequence of N. gonorrhoeae infection, was observed in N. gonorrhoeae-infected epithelial cells that had been preco-lonized with L. crispatus or preincubated with enolase and glutamine synthetase. Thus, our results indicate that the protection of human cells against N. gonorrhoeae infection is a complex process and that L. crispatus and its proteins enolase and glutamine synthetase can have a potential role in protecting epithelial cells against gonococcal infection. Therefore, these results are important since disturbances of the micro-biota or of its proteins can result in dysbiosis, which is associated with increased susceptibility of epithelium to pathogens.
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Use of Human Monocyte-Derived Macrophages to Study Neisseria gonorrhoeae Infection. Methods Mol Biol 2020. [PMID: 31119631 DOI: 10.1007/978-1-4939-9496-0_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Macrophages are critical cells in the innate immune response to microorganisms sensed in the tissues. During infections, the interaction between pathogens and macrophages leads to a macrophage response that includes cytokine production, antigen processing and presentation in the context of MHC molecules, expression of T cell costimulatory molecules and recruitment of innate defense effectors, which results in clearance of infection. However, Neisseria gonorrhoeae can suppress the protective immune response at this level, avoiding its detection and elimination. Studies addressed to develop the interactions between macrophages and Neisseria gonorrhoeae allow us to find potential targets to be exploited with vaccines and therapeutic drugs. In this chapter, we describe protocols to generate human monocyte-derived macrophages and assess their response to infection with Neisseria gonorrhoeae.
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Voter AF, Callaghan MM, Tippana R, Myong S, Dillard JP, Keck JL. Antigenic Variation in Neisseria gonorrhoeae Occurs Independently of RecQ-Mediated Unwinding of the pilE G Quadruplex. J Bacteriol 2020; 202:e00607-19. [PMID: 31740492 PMCID: PMC6964745 DOI: 10.1128/jb.00607-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/07/2019] [Indexed: 11/20/2022] Open
Abstract
The obligate human pathogen Neisseria gonorrhoeae alters its cell surface antigens to evade the immune system in a process known as antigenic variation (AV). During pilin AV, portions of the expressed pilin gene (pilE) are replaced with segments of silent pilin genes (pilS) through homologous recombination. The pilE-pilS exchange is initiated by formation of a parallel guanine quadruplex (G4) structure near the pilE gene, which recruits the homologous recombination machinery. The RecQ helicase, which has been proposed to aid AV by unwinding the pilE G4 structure, is an important component of this machinery. However, RecQ also promotes homologous recombination through G4-independent duplex DNA unwinding, leaving the relative importance of its G4 unwinding activity unclear. Previous investigations revealed a guanine-specific pocket (GSP) on the surface of RecQ that is required for G4, but not duplex, DNA unwinding. To determine whether RecQ-mediated G4 resolution is required for AV, N. gonorrhoeae strains that encode a RecQ GSP variant that cannot unwind G4 DNA were created. In contrast to the hypothesis that G4 unwinding by RecQ is important for AV, the RecQ GSP variant N. gonorrhoeae strains had normal AV levels. Analysis of a purified RecQ GSP variant confirmed that it retained duplex DNA unwinding activity but had lost its ability to unwind antiparallel G4 DNA. Interestingly, neither the GSP-deficient RecQ variant nor the wild-type RecQ could unwind the parallel pilE G4 nor the prototypical c-myc G4. Based on these results, we conclude that N. gonorrhoeae AV occurs independently of RecQ-mediated pilE G4 resolution.IMPORTANCE The pathogenic bacteria Neisseria gonorrhoeae avoids clearance by the immune system through antigenic variation (AV), the process by which immunogenic surface features of the bacteria are exchanged for novel variants. RecQ helicase is critical in AV and its role has been proposed to stem from its ability to unwind a DNA secondary structure known as a guanine quadruplex (G4) that is central to AV. In this work, we demonstrate that the role of RecQ in AV is independent of its ability to resolve G4s and that RecQ is incapable of unwinding the G4 in question. We propose a new model of RecQ's role in AV where the G4 might recruit or orient RecQ to facilitate homologous recombination.
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Affiliation(s)
- Andrew F Voter
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Melanie M Callaghan
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Ramreddy Tippana
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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Transcriptional regulation of a gonococcal gene encoding a virulence factor (L-lactate permease). PLoS Pathog 2019; 15:e1008233. [PMID: 31860664 PMCID: PMC6957213 DOI: 10.1371/journal.ppat.1008233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/13/2020] [Accepted: 11/22/2019] [Indexed: 12/16/2022] Open
Abstract
GdhR is a GntR-type regulator of Neisseria gonorrhoeae encoded by a gene (gdhR) belonging to the MtrR regulon, which comprises multiple genes required for antibiotic resistance such as the mtrCDE efflux pump genes. In previous work we showed that loss of gdhR results in enhanced gonococcal fitness in a female mouse model of lower genital tract infection. Here, we used RNA-Seq to perform a transcriptional profiling study to determine the GdhR regulon. GdhR was found to regulate the expression of 2.3% of all the genes in gonococcal strain FA19, of which 39 were activated and 11 were repressed. Within the GdhR regulon we found that lctP, which encodes a unique L-lactate transporter and has been associated with gonococcal pathogenesis, was the highest of GdhR-repressed genes. By using in vitro transcription and DNase I footpriting assays we mapped the lctP transcriptional start site (TSS) and determined that GdhR directly inhibits transcription by binding to an inverted repeat sequence located 9 bases downstream of the lctP TSS. Epistasis analysis revealed that, while loss of lctP increased susceptibility of gonococci to hydrogen peroxide (H2O2) the loss of gdhR enhanced resistance; however, this GdhR-endowed property was reversed in a double gdhR lctP null mutant. We assessed the effect of different carbon sources on lctP expression and found that D-glucose, but not L-lactate or pyruvate, repressed lctP expression within a physiological concentration range but in a GdhR-independent manner. Moreover, we found that adding glucose to the medium enhanced susceptibility of gonococci to hydrogen peroxide. We propose a model for the role of lctP regulation via GdhR and glucose in the pathogenesis of N. gonorrhoeae.
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Płaczkiewicz J, Adamczyk-Popławska M, Lasek R, Bącal P, Kwiatek A. Inactivation of Genes Encoding MutL and MutS Proteins Influences Adhesion and Biofilm Formation by Neisseria gonorrhoeae. Microorganisms 2019; 7:microorganisms7120647. [PMID: 31817122 PMCID: PMC6955733 DOI: 10.3390/microorganisms7120647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 11/16/2022] Open
Abstract
Neisseria gonorrhoeae is an etiological agent of gonorrhea, which remains a global health problem. This bacterium possesses MutL and MutS DNA repair proteins encoded by mutL and mutS genes, whose inactivation causes a mutator phenotype. We have demonstrated the differential gene expression in N. gonorrhoeae mutL and mutS mutants using DNA microarrays. A subset of differentially expressed genes encodes proteins that can influence adhesion and biofilm formation. Compared to the wild-type strain, N. gonorrhoeae mutL and mutS mutants formed denser biofilms with increased biofilm-associated biomass on the abiotic surface. The N. gonorrhoeae mutS::km, but not the mutL mutant, was also more adherent and invasive to human epithelial cells. Further, during infection of epithelial cells with N. gonorrhoeae mutS::km, the expression of some bacterial genes encoding proteins that can influence gonococcal adhesion was changed compared with their expression in cells infected with the wild-type gonococcus, as well as of human genes' encoding receptors utilized by N. gonorrhoeae (CD46, CEACAM 1, HSPG 2). Thus, deficiency in the mutS gene resulting in increased mutation frequency in singular organisms can be beneficial in populations because these mutants can be a source of features linked to microbial fitness.
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Affiliation(s)
- Jagoda Płaczkiewicz
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Monika Adamczyk-Popławska
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Robert Lasek
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
| | - Pawel Bącal
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, 02-109 Warsaw, Poland
| | - Agnieszka Kwiatek
- Institute of Microbiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland; (J.P.); (M.A.-P.); (R.L.)
- Correspondence: ; Tel.: +48-22-554-14-21
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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.
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Kim WJ, Higashi D, Goytia M, Rendón MA, Pilligua-Lucas M, Bronnimann M, McLean JA, Duncan J, Trees D, Jerse AE, So M. Commensal Neisseria Kill Neisseria gonorrhoeae through a DNA-Dependent Mechanism. Cell Host Microbe 2019; 26:228-239.e8. [PMID: 31378677 DOI: 10.1016/j.chom.2019.07.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/25/2019] [Accepted: 07/11/2019] [Indexed: 12/13/2022]
Abstract
The mucosa is colonized with commensal Neisseria. Some of these niches are sites of infection for the STD pathogen Neisseria gonorrhoeae (Ngo). Given the antagonistic behavior of commensal bacteria toward their pathogenic relatives, we hypothesized that commensal Neisseria may negatively affect Ngo colonization. Here, we report that commensal species of Neisseria kill Ngo through a mechanism based on genetic competence and DNA methylation state. Specifically, commensal-triggered killing occurs when the pathogen takes up commensal DNA containing a methylation pattern that it does not recognize. Indeed, any DNA will kill Ngo if it can enter the cell, is differentially methylated, and has homology to the pathogen genome. Consistent with these findings, commensal Neisseria elongata accelerates Ngo clearance from the mouse in a DNA-uptake-dependent manner. Collectively, we propose that commensal Neisseria antagonizes Ngo infection through a DNA-mediated mechanism and that DNA is a potential microbicide against this highly drug-resistant pathogen.
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Affiliation(s)
- Won Jong Kim
- Department of Immunobiology and the BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Dustin Higashi
- Department of Immunobiology and the BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Maira Goytia
- Department of Biology, Spelman College, Atlanta, GA 30314, USA
| | - Maria A Rendón
- Department of Immunobiology and the BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Michelle Pilligua-Lucas
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA
| | - Matthew Bronnimann
- Department of Immunobiology and the BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
| | - Jeanine A McLean
- Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - Joseph Duncan
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David Trees
- Centers for Disease Control and Prevention, Atlanta, GA 30329, USA
| | - Ann E Jerse
- Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD 20814, USA
| | - Magdalene So
- Department of Immunobiology and the BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA.
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Rendón MA, Lona B, Ma M, So M. RpoN and the Nps and Npa two-component regulatory system control pilE transcription in commensal Neisseria. Microbiologyopen 2019; 8:e00713. [PMID: 30079633 PMCID: PMC6528607 DOI: 10.1002/mbo3.713] [Citation(s) in RCA: 5] [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: 06/28/2018] [Revised: 07/10/2018] [Accepted: 07/11/2018] [Indexed: 01/06/2023] Open
Abstract
Over 20 genes are involved in the biogenesis and function of the Neisseria Type IV pilus (Tfp). In the pathogenic species, RpoD and the integration host factor (IHF) protein regulate expression of pilE, encoding the Tfp structural subunit. We previously reported that in commensal species, pilE transcription is regulated by RpoN, IHF, and activator Npa. Npa has many hallmarks of response regulators in two-component regulatory systems, leading us to search for its response regulator partner. We report that Npa partners with sensor kinase Nps to control pilE transcription. Among the genes involved in Tfp biogenesis and function, only pilE is controlled by RpoN and Npa/Nps. We summarize our findings in a model, and discuss the implications of the differential regulation of pilE the context of Neisseria Tfp biogenesis.
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Affiliation(s)
- María A. Rendón
- The BIO5 Institute and Department of ImmunobiologyUniversity of ArizonaTucsonArizona
| | - Beatriz Lona
- The BIO5 Institute and Department of ImmunobiologyUniversity of ArizonaTucsonArizona
- Present address:
Sterility Assurance Labs
| | - Mancheong Ma
- The BIO5 Institute and Department of ImmunobiologyUniversity of ArizonaTucsonArizona
| | - Magdalene So
- The BIO5 Institute and Department of ImmunobiologyUniversity of ArizonaTucsonArizona
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Pharmacokinetic Data Are Predictive of In Vivo Efficacy for Cefixime and Ceftriaxone against Susceptible and Resistant Neisseria gonorrhoeae Strains in the Gonorrhea Mouse Model. Antimicrob Agents Chemother 2019; 63:AAC.01644-18. [PMID: 30642924 DOI: 10.1128/aac.01644-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 12/18/2018] [Indexed: 01/10/2023] Open
Abstract
There is a pressing need for drug development for gonorrhea. Here we describe a pharmacokinetic (PK)/pharmacodynamic (PD) analysis of extended-spectrum cephalosporins (ESC) against drug-susceptible and drug-resistant gonococcal strains in a murine genital tract infection model. The PK determined in uninfected mice displayed a clear dose-response in plasma levels following single doses of ceftriaxone (CRO) (intraperitoneal) or cefixime (CFM) (oral). The observed doses required for efficacy against ESC-susceptible (ESCs) strain FA1090 were 5 mg/kg of body weight (CRO) and 12 mg/kg (CFM); these doses had estimated therapeutic times (the time that the free drug concentration remains above the MIC [fT MIC]) of 24 h and 37 h, respectively. No single dose of CRO or CFM was effective against ESC-resistant (ESCr) strain H041. However, fractionation (three times a day every 8 h [TIDq8h]) of a 120-mg/kg dose of CRO resulted in estimated therapeutic times in the range of 23 h and cleared H041 infection in a majority (90%) of mice, comparable to the findings for gentamicin. In contrast, multiple CFM doses of 120 or 300 mg/kg administered TIDq8h cleared infection in ≤50% of mice, with the therapeutic times estimated from single-dose PK data being 13 and 27 h, respectively. This study reveals a clear relationship between plasma ESC levels and bacterial clearance rates in the gonorrhea mouse model. The PK/PD relationships observed in mice reflected those observed in humans, with in vivo efficacy against an ESCs strain requiring doses that yielded an fT MIC in excess of 20 to 24 h. PK data also accurately predicted the failure of single doses of ESCs against an ESCr strain and were useful in designing effective dosing regimens.
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Álamos-Musre AS, Escobar A, Tapia CV, Christodoulides M, Rodas PI. Use of Human Fallopian Tube Organ in Culture (FTOC) and Primary Fallopian Tube Epithelial Cells (FTEC) to Study the Biology of Neisseria gonorrhoeae Infection. Methods Mol Biol 2019; 1997:377-402. [PMID: 31119635 DOI: 10.1007/978-1-4939-9496-0_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epithelial cells represent one of the most important physical barriers to many bacterial pathogens. In the case of Neisseria gonorrhoeae, the epithelial cell response is critical because they are the main target of the tissue damage triggered by the pathogen, particularly when the organism reaches the Fallopian tube (FT). Although the irreversible damage triggered by N. gonorrhoeae in the FT has been previously reported (ectopic pregnancy, pelvic inflammatory disease and infertility), the mechanisms of gonococcal-induced tissue damage are not fully understood. In addition, the lack of animal models that efficiently mimic the human disease and the complexity of gonococcus-host interactions make studying gonococcal pathogenesis particularly difficult. The use of human immortalized cells is also limited, since a variety of commercial FT cell lines is not yet available. Finally, the phase and antigenic variation of many gonococcal surface molecules involved in attachment and invasion of epithelial tissues leads to a failure to reproduce results using different human cells lines used in previous studies. The FT organ in culture (FTOC) and primary human fallopian tube epithelial cell (FTEC) represent the closest ex vivo cell models to explore the biology of Neisseria gonorrhoeae during infection of the FT, since it is a natural host target of the gonococcus. In this chapter, we describe protocols to process human FT samples to obtain FTOC and FTEC and assess their response to infection with Neisseria gonorrhoeae.
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Affiliation(s)
- A Said Álamos-Musre
- Laboratory of Medical Microbiology and Pathogenesis, Faculty of Medicine, Universidad Andres Bello, Concepción, Región del Bío-Bío, Chile
| | - Alejandro Escobar
- Laboratorio Biología celular y molecular, Instituto de Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Región Metropolitana, Chile
| | - Cecilia V Tapia
- Laboratorio de Especialidad, Clínica Dávila, Santiago, Región Metropolitana, Chile
| | - Myron Christodoulides
- Molecular Microbiology Group, Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Paula I Rodas
- Laboratory of Medical Microbiology and Pathogenesis, Faculty of Medicine, Universidad Andres Bello, Concepción, Región del Bío-Bío, Chile.
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Protocols to Interrogate the Interactions Between Neisseria gonorrhoeae and Primary Human Neutrophils. Methods Mol Biol 2019; 1997:319-345. [PMID: 31119632 DOI: 10.1007/978-1-4939-9496-0_19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neisseria gonorrhoeae (Gc) infection of its obligate human host results in a robust neutrophil-driven immune response. Despite neutrophils' intrinsic ability to neutralize microbes, Gc can survive in the presence of neutrophils. To interrogate how this pathogen evades killing by neutrophils, we employ an ex vivo model of Gc infection with Interleukin-8-primed and adhered primary human neutrophils. This chapter will describe how primary human neutrophils are purified from venous blood, how Gc is prepared for infection, how to assess Gc survival in the presence of human neutrophils by enumeration of colony forming units, and how to determine Gc internalization by human neutrophils using an immunofluorescence-based approach.
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48
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Lenz JD, Shirk KA, Jolicoeur A, Dillard JP. Selective Inhibition of Neisseria gonorrhoeae by a Dithiazoline in Mixed Infections with Lactobacillus gasseri. Antimicrob Agents Chemother 2018; 62:e00826-18. [PMID: 30275084 PMCID: PMC6256793 DOI: 10.1128/aac.00826-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/22/2018] [Indexed: 11/20/2022] Open
Abstract
The Gram-negative human pathogen Neisseria gonorrhoeae has progressively developed resistance to antibiotic monotherapies, and recent failures of dual-drug therapy have heightened concerns that strains resistant to all available antibiotics will begin circulating globally. Targeting bacterial cell wall assembly has historically been effective at treating infections with N. gonorrhoeae, but as the effectiveness of β-lactams (including cephalosporins) is challenged by increasing resistance, research has expanded into compounds that target the numerous other enzymes with roles in peptidoglycan metabolism. One example is the dithiazoline compound JNJ-853346 (DTZ), which inhibits the activity of an Escherichia coli serine protease l,d-carboxypeptidase (LdcA). Recently, the characterization of an LdcA homolog in N. gonorrhoeae revealed localization and activity differences from the characterized E. coli LdcA, prompting us to explore the effectiveness of DTZ against N. gonorrhoeae We found that DTZ is effective at inhibiting N. gonorrhoeae in all growth phases, unlike the specific stationary-phase inhibition seen in E. coli Surprisingly, DTZ does not inhibit gonococcal LdcA enzyme activity, and DTZ sensitivity is not significantly decreased in ldcA mutants. While effective against numerous N. gonorrhoeae strains, including recent multidrug-resistant isolates, DTZ is much less effective at inhibiting growth of the commensal species Lactobacillus gasseri DTZ treatment during coinfections of epithelial cells resulted in significant lowering of gonococcal burden and interleukin-8 secretion without significantly impacting recovery of viable L. gasseri This selective toxicity presents a possible pathway for the use of DTZ as an effective antigonococcal agent at concentrations that do not impact vaginal commensals.
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Affiliation(s)
- Jonathan D Lenz
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Kristina A Shirk
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Adrienne Jolicoeur
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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49
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Alfsnes K, Frye SA, Eriksson J, Eldholm V, Brynildsrud OB, Bohlin J, Harrison OB, Hood DW, Maiden MCJ, Tønjum T, Ambur OH. A genomic view of experimental intraspecies and interspecies transformation of a rifampicin-resistance allele into Neisseria meningitidis. Microb Genom 2018; 4. [PMID: 30251949 PMCID: PMC6321871 DOI: 10.1099/mgen.0.000222] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The spread of antibiotic resistance within and between different bacterial populations is a major health problem on a global scale. The identification of genetic transformation in genomic data from Neisseria meningitidis, the meningococcus (Mc), and other bacteria is problematic, since similar or even identical alleles may be involved. A particular challenge in naturally transformable bacteria generally is to distinguish between common ancestry and true recombined sites in sampled genome sequences. Furthermore, the identification of recombination following experimental transformation of homologous alleles requires identifiable differences between donor and recipient, which in itself influences the propensity for homologous recombination (HR). This study identifies the distribution of HR events following intraspecies and interspecies Mc transformations of rpoB alleles encoding rifampicin resistance by whole-genome DNA sequencing and single nucleotide variant analysis. The HR events analysed were confined to the genomic region surrounding the single nucleotide genetic marker used for selection. An exponential length distribution of these recombined events was found, ranging from a few nucleotides to about 72 kb stretches. The lengths of imported sequences were on average found to be longer following experimental transformation of the recipient with genomic DNA from an intraspecies versus an interspecies donor (P<0.001). The recombination events were generally observed to be mosaic, with donor sequences interspersed with recipient sequence. Here, we present four models to explain these observations, by fragmentation of the transformed DNA, by interruptions of the recombination mechanism, by secondary recombination of endogenous self-DNA, or by repair/replication mechanisms.
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Affiliation(s)
| | - Stephan A Frye
- 2Department of Microbiology, Oslo University Hospital (Rikshospitalet), Oslo, Norway
| | - Jens Eriksson
- 2Department of Microbiology, Oslo University Hospital (Rikshospitalet), Oslo, Norway
| | - Vegard Eldholm
- 3Department of Molecular Biology, Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Ola Brønstad Brynildsrud
- 4Department of Methodology Research and Analysis, Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Jon Bohlin
- 4Department of Methodology Research and Analysis, Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Odile B Harrison
- 5The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| | - Derek W Hood
- 6Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK
| | - Martin C J Maiden
- 5The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK
| | - Tone Tønjum
- 2Department of Microbiology, Oslo University Hospital (Rikshospitalet), Oslo, Norway.,7Department of Microbiology, University of Oslo, Oslo, Norway
| | - Ole Herman Ambur
- 2Department of Microbiology, Oslo University Hospital (Rikshospitalet), Oslo, Norway.,8OsloMet - Oslo Metropolitan University, Oslo, Norway
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50
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Green LR, Lucidarme J, Dave N, Chan H, Clark S, Borrow R, Bayliss CD. Phase Variation of NadA in Invasive Neisseria meningitidis Isolates Impacts on Coverage Estimates for 4C-MenB, a MenB Vaccine. J Clin Microbiol 2018; 56:e00204-18. [PMID: 29950334 PMCID: PMC6113495 DOI: 10.1128/jcm.00204-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/19/2018] [Indexed: 11/20/2022] Open
Abstract
A recombinant NadA protein is one of the four major protective antigens of 4C-MenB (Bexsero), a vaccine developed for serogroup B Neisseria meningitidis (MenB). The meningococcal antigen typing system (MATS) is utilized as a high-throughput assay for assessing the invasive MenB strain coverage of 4C-MenB. Where present, the nadA gene is subject to phase-variable changes in transcription due to a 5'TAAA repeat tract located in a regulatory region. The promoter-containing intergenic region (IGR) sequences and 5'TAAA repeat numbers were determined for 906 invasive meningococcal disease isolates possessing the nadA gene. Exclusion of the 5'TAAA repeats reduced the number of IGR alleles from 82 to 23. Repeat numbers were associated with low and high levels of NadA expression by Western blotting and enzyme-linked immunosorbent assay (ELISA). Low-expression repeat numbers were present in 83% of 179 MenB isolates with NadA-2/3 or NadA-1 peptide variants and 68% of 480 MenW ST-11 complex isolates with NadA-2/3 peptide variants. For isolates with vaccine-compatible NadA variants, 93% of MATS-negative isolates were associated with low-expression repeat numbers, whereas 63% of isolates with MATS relative potency (RP) scores above the 95% confidence interval for the positive bactericidal threshold had high-expression repeat numbers. Analysis of 5'TAAA repeat numbers has potential as a rapid, high-throughput method for assessing strain coverage for the NadA component of 4C-MenB. A key application will be assessing coverage in meningococcal disease cases where confirmation is by PCR only and MATS cannot be applied.
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Affiliation(s)
- Luke R Green
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Jay Lucidarme
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Neelam Dave
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Hannah Chan
- National Institute for Biological Standards and Control, Potters Bar, United Kingdom
| | - Stephen Clark
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Ray Borrow
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester, United Kingdom
| | - Christopher D Bayliss
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
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