1
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Manca B, Buffi G, Magri G, Del Vecchio M, Taddei AR, Pezzicoli A, Giuliani M. Functional characterization of the gonococcal polyphosphate pseudo-capsule. PLoS Pathog 2023; 19:e1011400. [PMID: 37216411 DOI: 10.1371/journal.ppat.1011400] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 05/03/2023] [Indexed: 05/24/2023] Open
Abstract
Neisseria gonorrhoeae is an exclusively human pathogen able to evade the host immune system through multiple mechanisms. Gonococci accumulate a large portion of phosphate moieties as polyphosphate (polyP) on the exterior of the cell. Although its polyanionic nature has suggested that it may form a protective shield on the cell surface, its role remains controversial. Taking advantage of a recombinant His-tagged polyP-binding protein, the presence of a polyP pseudo-capsule in gonococcus was demonstrated. Interestingly, the polyP pseudo-capsule was found to be present in specific strains only. To investigate its putative role in host immune evasion mechanisms, such as resistance to serum bactericidal activity, antimicrobial peptides and phagocytosis, the enzymes involved in polyP metabolism were genetically deleted, generating mutants with altered polyP external content. The mutants with lower polyP content on their surface compared to the wild-type strains, became sensitive to complement-mediated killing in presence of normal human serum. Conversely, naturally serum sensitive strains that did not display a significant polyP pseudo-capsule became resistant to complement in the presence of exogenous polyP. The presence of polyP pseudo-capsule was also critical in the protection from antibacterial activity of cationic antimicrobial peptide, such as cathelicidin LL-37. Results showed that the minimum bactericidal concentration was lower in strains lacking polyP than in those harboring the pseudo-capsule. Data referring to phagocytic killing resistance, assessed by using neutrophil-like cells, showed a significant decrease in viability of mutants lacking polyP on their cell surface in comparison to the wild-type strain. The addition of exogenous polyP overturned the killing phenotype of sensitive strains suggesting that gonococcus could exploit environmental polyP to survive to complement-mediated, cathelicidin and intracellular killing. Taken together, data presented here indicate an essential role of the polyP pseudo-capsule in the gonococcal pathogenesis, opening new perspective on gonococcal biology and more effective treatments.
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Affiliation(s)
- Benedetta Manca
- Pharmacy and Biotechnology Department (FaBiT), University of Bologna, Bologna, Italy C/O GSK, Siena, Italy
| | | | | | | | - Anna Rita Taddei
- Centre for High Instruments, Electron Microscopy Section, University of Tuscia, Viterbo, Italy
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2
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Ayala JC, Balthazar JT, Shafer WM. Transcriptional regulation of the mtrCDE efflux pump operon: importance for Neisseria gonorrhoeae antimicrobial resistance. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35916832 DOI: 10.1099/mic.0.001231] [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
This review focuses on the mechanisms of transcriptional control of an important multidrug efflux pump system (MtrCDE) possessed by Neisseria gonorrhoeae, the aetiological agent of the sexually transmitted infection termed gonorrhoea. The mtrCDE operon that encodes this tripartite protein efflux pump is subject to both cis- and trans-acting transcriptional factors that negatively or positively influence expression. Critically, levels of MtrCDE can influence levels of gonococcal susceptibility to classical antibiotics, host-derived antimicrobials and various biocides. The regulatory systems that control mtrCDE can have profound influences on the capacity of gonococci to resist current and past antibiotic therapy regimens as well as virulence. The emergence, mechanisms of action and clinical significance of the transcriptional regulatory systems that impact mtrCDE expression in gonococci are reviewed here with the aim of linking bacterial antimicrobial resistance with multidrug efflux capability.
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Affiliation(s)
- Julio C Ayala
- Department of Microbiology and Immunology Emory University School of Medicine, Atlanta, Georgia, 30322, USA
| | - Jacqueline T Balthazar
- Department of Microbiology and Immunology Emory University School of Medicine, Atlanta, Georgia, 30322, USA
| | - William M Shafer
- Department of Microbiology and Immunology Emory University School of Medicine, Atlanta, Georgia, 30322, USA.,Laboratories of Bacterial Pathogenesis, VA Medical Center (Atlanta), Decatur, Georgia, 30033, USA.,The Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia, USA
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3
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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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4
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Beggs GA, Brennan RG, Arshad M. MarR family proteins are important regulators of clinically relevant antibiotic resistance. Protein Sci 2019; 29:647-653. [PMID: 31682303 DOI: 10.1002/pro.3769] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 12/14/2022]
Abstract
There has been a rapid spread of multidrug-resistant (MDR) bacteria across the world. MDR efflux transporters are an important mechanism of antibiotic resistance in many pathogens among both Gram positive and Gram negative bacteria. These pumps can recognize a variety of chemically and structurally different compounds, including innate and clinically administered antibiotics. Intriguingly, these efflux pumps are often regulated by transcription factors that themselves bind a diverse set of substrates thereby allowing them to regulate the expression of their cognate MDR efflux pumps. One significant family of such transcription factors is the Multiple antibiotic resistance Repressor (MarR) family. Members of this family are well conserved across different bacterial species and in some cases are known to regulate vital bacterial functions. This review focusses on the role of MarR family transcriptional factors in antibiotic resistance within a select group of clinically relevant pathogens.
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Affiliation(s)
- Grace A Beggs
- Department of Biochemistry, Duke University, Durham, North Carolina
| | | | - Mehreen Arshad
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital, Northwestern University, Chicago, Illinois
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5
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Baarda BI, Martinez FG, Sikora AE. Proteomics, Bioinformatics and Structure-Function Antigen Mining For Gonorrhea Vaccines. Front Immunol 2018; 9:2793. [PMID: 30564232 PMCID: PMC6288298 DOI: 10.3389/fimmu.2018.02793] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/13/2018] [Indexed: 12/12/2022] Open
Abstract
Expanding efforts to develop preventive gonorrhea vaccines is critical because of the serious health consequences combined with the prevalence and the dire possibility of untreatable gonorrhea. Reverse vaccinology, which includes genome and proteome mining, has proven successful in the discovery of vaccine candidates against many pathogenic bacteria. Here, we describe proteomic applications including comprehensive, quantitative proteomic platforms and immunoproteomics coupled with broad-ranging bioinformatics that have been applied for antigen mining to develop gonorrhea vaccine(s). We further focus on outlining the vaccine candidate decision tree, describe the structure-function of novel proteome-derived antigens as well as ways to gain insights into their roles in the cell envelope, and underscore new lessons learned about the fascinating biology of Neisseria gonorrhoeae.
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Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Fabian G. Martinez
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
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6
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Mutations in Neisseria gonorrhoeae grown in sub-lethal concentrations of monocaprin do not confer resistance. PLoS One 2018; 13:e0195453. [PMID: 29621310 PMCID: PMC5886539 DOI: 10.1371/journal.pone.0195453] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/22/2018] [Indexed: 11/19/2022] Open
Abstract
Neisseria gonorrhoeae, due to its short lipooligosaccharide structure, is generally more sensitive to the antimicrobial effects of some fatty acids than most other Gram negative bacteria. This supports recent development of a fatty acid-based potential treatment for gonococcal infections, particularly ophthalmia neonatorum. The N. gonorrhoeae genome contains genes for fatty acid resistance. In this study, the potential for genomic mutations that could lead to resistance to this potential new treatment were investigated. N. gonorrhoeae strain NCCP11945 was repeatedly passaged on growth media containing a sub-lethal concentration of fatty acid myristic acid and monoglyceride monocaprin. Cultures were re-sequenced and assessed for changes in minimum inhibitory concentration. Of note, monocaprin grown cultures developed a mutation in transcription factor gene dksA, which suppresses molecular chaperone DnaK and may be involved in the stress response. The minimum inhibitory concentration after exposure to monocaprin showed a modest two-fold change. The results of this study suggest that N. gonorrhoeae cannot readily evolve resistance that will impact treatment of ophthalmia neonatorum with monocaprin.
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7
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Kandler JL, Acevedo RV, Dickinson MK, Cash DR, Shafer WM, Cornelissen CN. The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions. Mol Microbiol 2016; 102:137-51. [PMID: 27353397 DOI: 10.1111/mmi.13450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 01/01/2023]
Abstract
Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.
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Affiliation(s)
- Justin L Kandler
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia
| | - Rosuany Vélez Acevedo
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Mary Kathryne Dickinson
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Devin R Cash
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Medical Center, Laboratories of Microbial Pathogenesis, Decatur, Georgia
| | - Cynthia Nau Cornelissen
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia.
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8
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The Transcriptional Repressor, MtrR, of the mtrCDE Efflux Pump Operon of Neisseria gonorrhoeae Can Also Serve as an Activator of "off Target" Gene (glnE) Expression. Antibiotics (Basel) 2016; 4:188-97. [PMID: 26078871 PMCID: PMC4464784 DOI: 10.3390/antibiotics4020188] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
MtrR is a well-characterized repressor of the Neisseria gonorrhoeaemtrCDE efflux pump operon. However, results from a previous transcriptional profiling study suggested that MtrR also represses or activates expression of at least sixty genes outside of the mtr locus. Evidence that MtrR can directly repress so-called “off target” genes has previously been reported; in particular, MtrR was shown to directly repress glnA, which encodes glutamine synthetase. In contrast, evidence for the ability of MtrR to directly activate expression of gonococcal genes has been lacking; herein, we provide such evidence. We now report that MtrR has the ability to directly activate expression of glnE, which encodes the dual functional adenyltransferase/deadenylase enzyme GlnE that modifies GlnA resulting in regulation of its role in glutamine biosynthesis. With its capacity to repress expression of glnA, the results presented herein emphasize the diverse and often opposing regulatory properties of MtrR that likely contributes to the overall physiology and metabolism of N. gonorrhoeae.
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9
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Antimicrobial resistance in Neisseria gonorrhoeae in the 21st century: past, evolution, and future. Clin Microbiol Rev 2015; 27:587-613. [PMID: 24982323 DOI: 10.1128/cmr.00010-14] [Citation(s) in RCA: 771] [Impact Index Per Article: 85.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Neisseria gonorrhoeae is evolving into a superbug with resistance to previously and currently recommended antimicrobials for treatment of gonorrhea, which is a major public health concern globally. Given the global nature of gonorrhea, the high rate of usage of antimicrobials, suboptimal control and monitoring of antimicrobial resistance (AMR) and treatment failures, slow update of treatment guidelines in most geographical settings, and the extraordinary capacity of the gonococci to develop and retain AMR, it is likely that the global problem of gonococcal AMR will worsen in the foreseeable future and that the severe complications of gonorrhea will emerge as a silent epidemic. By understanding the evolution, emergence, and spread of AMR in N. gonorrhoeae, including its molecular and phenotypic mechanisms, resistance to antimicrobials used clinically can be anticipated, future methods for genetic testing for AMR might permit region-specific and tailor-made antimicrobial therapy, and the design of novel antimicrobials to circumvent the resistance problems can be undertaken more rationally. This review focuses on the history and evolution of gonorrhea treatment regimens and emerging resistance to them, on genetic and phenotypic determinants of gonococcal resistance to previously and currently recommended antimicrobials, including biological costs or benefits; and on crucial actions and future advances necessary to detect and treat resistant gonococcal strains and, ultimately, retain gonorrhea as a treatable infection.
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10
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Overproduction of the MtrCDE efflux pump in Neisseria gonorrhoeae produces unexpected changes in cellular transcription patterns. Antimicrob Agents Chemother 2014; 59:724-6. [PMID: 25367915 DOI: 10.1128/aac.04148-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The global consequence of drug efflux gene overexpression in bacteria has not been specifically analyzed because strains showing high-level expression typically have mutations in genes encoding regulatory proteins that control other genes. Results from a transcriptional profiling study performed with a strain of Neisseria gonorrhoeae that is capable of high-level transcription of the mtrCDE efflux pump operon independently of control by cognate regulatory proteins revealed that its overexpression has ramifications for systems other than drug efflux.
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11
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Rice PA. Editorial commentary: The shifting sands of gonococcal antimicrobial resistance. Clin Infect Dis 2014; 59:1092-4. [PMID: 25031290 DOI: 10.1093/cid/ciu526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Peter A Rice
- Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester
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12
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Cloward JM, Shafer WM. MtrR control of a transcriptional regulatory pathway in Neisseria meningitidis that influences expression of a gene (nadA) encoding a vaccine candidate. PLoS One 2013; 8:e56097. [PMID: 23409129 PMCID: PMC3568044 DOI: 10.1371/journal.pone.0056097] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 01/07/2013] [Indexed: 11/18/2022] Open
Abstract
The surface-exposed NadA adhesin produced by a subset of capsular serogroup B strains of Neisseria meningitidis is currently being considered as a vaccine candidate to prevent invasive disease caused by a hypervirulent lineage of meningococci. Levels of NadA are known to be controlled by both transcriptional regulatory factors and a component of human saliva, 4-hydroxyphenylacetic acid. Herein, we confirmed the capacity of a DNA-binding protein termed FarR to negatively control nadA expression. We also found that a known transcriptional regulator of farR in N. gonorrhoeae termed MtrR can have a negative regulatory impact on farR and nadA expression, especially when over-expressed. MtrR-mediated repression of nadA was found to be direct, and its binding to a target DNA sequence containing the nadA promoter influenced formation and/or stability of FarR::nadA complexes. The complexity of the multi-layered regulation of nadA uncovered during this investigation suggests that N. meningitidis modulates NadA adhesin protein levels for the purpose of interacting with host cells yet avoiding antibody directed against surface exposed epitopes.
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Affiliation(s)
- Jason M. Cloward
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center (Atlanta), Decatur, Georgia, United States of America
| | - William M. Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America
- Laboratories of Bacterial Pathogenesis, Veterans Affairs Medical Center (Atlanta), Decatur, Georgia, United States of America
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13
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Alvarez-Ortega C, Olivares J, Martínez JL. RND multidrug efflux pumps: what are they good for? Front Microbiol 2013; 4:7. [PMID: 23386844 PMCID: PMC3564043 DOI: 10.3389/fmicb.2013.00007] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 01/07/2013] [Indexed: 01/27/2023] Open
Abstract
Multidrug efflux pumps are chromosomally encoded genetic elements capable of mediating resistance to toxic compounds in several life forms. In bacteria, these elements are involved in intrinsic and acquired resistance to antibiotics. Unlike other well-known horizontally acquired antibiotic resistance determinants, genes encoding for multidrug efflux pumps belong to the core of bacterial genomes and thus have evolved over millions of years. The selective pressure stemming from the use of antibiotics to treat bacterial infections is relatively recent in evolutionary terms. Therefore, it is unlikely that these elements have evolved in response to antibiotics. In the last years, several studies have identified numerous functions for efflux pumps that go beyond antibiotic extrusion. In this review we present some examples of these functions that range from bacterial interactions with plant or animal hosts, to the detoxification of metabolic intermediates or the maintenance of cellular homeostasis.
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Affiliation(s)
- Carolina Alvarez-Ortega
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas Madrid, Spain
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14
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Unemo M, Nicholas RA. Emergence of multidrug-resistant, extensively drug-resistant and untreatable gonorrhea. Future Microbiol 2012; 7:1401-22. [PMID: 23231489 PMCID: PMC3629839 DOI: 10.2217/fmb.12.117] [Citation(s) in RCA: 320] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The new superbug Neisseria gonorrhoeae has retained resistance to antimicrobials previously recommended for first-line treatment and has now demonstrated its capacity to develop resistance to the extended-spectrum cephalosporin, ceftriaxone, the last remaining option for first-line empiric treatment of gonorrhea. An era of untreatable gonorrhea may be approaching, which represents an exceedingly serious public health problem. Herein, we review the evolution, origin and spread of antimicrobial resistance and resistance determinants (with a focus on extended-spectrum cephalosporins) in N. gonorrhoeae, detail the current situation regarding verified treatment failures with extended-spectrum cephalosporins and future treatment options, and highlight essential actions to meet the large public health challenge that arises with the possible emergence of untreatable gonorrhea. Essential actions include: implementing action/response plans globally and nationally; enhancing surveillance of gonococcal antimicrobial resistance, treatment failures and antimicrobial use/misuse; and improving prevention, early diagnosis and treatment of gonorrhea. Novel treatment strategies, antimicrobials (or other compounds) and, ideally, a vaccine must be developed.
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Affiliation(s)
- Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea & Other STIs, National Reference Laboratory for Pathogenic Neisseria, Örebro University Hospital, SE-701 85 Örebro, Sweden.
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15
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Unemo M, Shafer WM. Antibiotic resistance in Neisseria gonorrhoeae: origin, evolution, and lessons learned for the future. Ann N Y Acad Sci 2012; 1230:E19-28. [PMID: 22239555 DOI: 10.1111/j.1749-6632.2011.06215.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The strict human pathogen Neisseria gonorrhoeae has caused gonorrhea for thousands of years, and currently gonorrhea is the second most prevalent bacterial sexually transmitted infection worldwide. Given the ancient nature of N. gonorrhoeae and its unique obligate relationship with humankind over the millennia, its remarkable ability to adapt to the host immune system and cause repeated infections, and its propensity to develop resistance to all clinically useful antibiotics, the gonococcus is an ideal pathogen on which to study the evolution of bacterial pathogenesis, including antimicrobial resistance, over the long term and within the host during infection. Recently, the first gonococcus displaying high-level resistance to ceftriaxone, identified in Japan, was characterized in detail. Ceftriaxone is the last remaining option for empirical first-line treatment, and N. gonorrhoeae now seems to be evolving into a true "superbug." In the near future, gonorrhea may become untreatable in certain circumstances. Herein, the history of antibiotics used for treatment of gonorrhea, the evolution of resistance emergence in N. gonorrhoeae, the linkage between resistance and biological fitness of N. gonorrhoeae, lessons learned, and future perspectives are reviewed and discussed.
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Affiliation(s)
- Magnus Unemo
- National Reference Laboratory for Pathogenic Neisseria, Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden.
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