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Werner LM, Alcott A, Mohlin F, Ray JC, Belcher Dufrisne M, Smirnov A, Columbus L, Blom AM, Criss AK. Neisseria gonorrhoeae co-opts C4b-binding protein to enhance complement-independent survival from neutrophils. PLoS Pathog 2023; 19:e1011055. [PMID: 36862761 PMCID: PMC10013916 DOI: 10.1371/journal.ppat.1011055] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/14/2023] [Accepted: 02/07/2023] [Indexed: 03/03/2023] Open
Abstract
Neisseria gonorrhoeae (Gc) is a human-specific pathogen that causes the sexually transmitted infection gonorrhea. Gc survives in neutrophil-rich gonorrheal secretions, and recovered bacteria predominantly express phase-variable, surface-expressed opacity-associated (Opa) proteins (Opa+). However, expression of Opa proteins like OpaD decreases Gc survival when exposed to human neutrophils ex vivo. Here, we made the unexpected observation that incubation with normal human serum, which is found in inflamed mucosal secretions, enhances survival of Opa+ Gc from primary human neutrophils. We directly linked this phenomenon to a novel complement-independent function for C4b-binding protein (C4BP). When bound to the bacteria, C4BP was necessary and sufficient to suppress Gc-induced neutrophil reactive oxygen species production and prevent neutrophil phagocytosis of Opa+ Gc. This research identifies for the first time a complement-independent role for C4BP in enhancing the survival of a pathogenic bacterium from phagocytes, thereby revealing how Gc exploits inflammatory conditions to persist at human mucosal surfaces.
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Affiliation(s)
- Lacie M. Werner
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Allison Alcott
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Frida Mohlin
- Department of Translational Medicine, Lund University, Malmo, Sweden
| | - Jocelyn C. Ray
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Meagan Belcher Dufrisne
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, United States of America
| | - Asya Smirnov
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Linda Columbus
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, United States of America
| | - Anna M. Blom
- Department of Translational Medicine, Lund University, Malmo, Sweden
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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Free C, Palmer MJ, Potter K, McCarthy OL, Jerome L, Berendes S, Gubijev A, Knight M, Jamal Z, Dhaliwal F, Carpenter JR, Morris TP, Edwards P, French R, Macgregor L, Turner KME, Baraitser P, Hickson FCI, Wellings K, Roberts I, Bailey JV, Hart G, Michie S, Clayton T, Devries K. Behavioural intervention to reduce sexually transmitted infections in people aged 16–24 years in the UK: the safetxt RCT. PUBLIC HEALTH RESEARCH 2023. [DOI: 10.3310/dane8826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Background
The prevalence of genital chlamydia and gonorrhoea is higher in the 16–24 years age group than those in other age group. With users, we developed the theory-based safetxt intervention to reduce sexually transmitted infections.
Objectives
To establish the effect of the safetxt intervention on the incidence of chlamydia/gonorrhoea infection at 1 year.
Design
A parallel-group, individual-level, randomised superiority trial in which care providers and outcome assessors were blinded to allocation.
Setting
Recruitment was from 92 UK sexual health clinics.
Participants
Inclusion criteria were a positive chlamydia or gonorrhoea test result, diagnosis of non-specific urethritis or treatment started for chlamydia/gonorrhoea/non-specific urethritis in the last 2 weeks; owning a personal mobile phone; and being aged 16–24 years.
Allocation
Remote computer-based randomisation with an automated link to the messaging system delivering intervention or control group messages.
Intervention
The safetxt intervention was designed to reduce sexually transmitted infection by increasing partner notification, condom use and sexually transmitted infection testing before sex with new partners. It employed educational, enabling and incentivising content delivered by 42–79 text messages over 1 year, tailored according to type of infection, gender and sexuality.
Comparator
A monthly message regarding trial participation.
Main outcomes
The primary outcome was the incidence of chlamydia and gonorrhoea infection at 12 months, assessed using nucleic acid amplification tests. Secondary outcomes at 1 and 12 months included self-reported partner notification, condom use and sexually transmitted infection testing prior to sex with new partner(s).
Results
Between 1 April 2016 and 23 November 2018, we assessed 20,476 people for eligibility and consented and randomised 6248 participants, allocating 3123 to the safetxt intervention and 3125 to the control. Primary outcome data were available for 4675 (74.8%) participants. The incidence of chlamydia/gonorrhoea infection was 22.2% (693/3123) in the intervention group and 20.3% (633/3125) in the control group (odds ratio 1.13, 95% confidence interval 0.98 to 1.31). There was no evidence of heterogeneity in any of the prespecified subgroups. Partner notification was 85.6% in the intervention group and 84.0% in the control group (odds ratio 1.14, 95% confidence interval 0.99 to 1.33). At 12 months, condom use at last sex was 33.8% in the intervention group and 31.2% in the control group (odds ratio 1.14, 95% confidence interval 1.01 to 1.28) and condom use at first sex with most recent new partner was 54.4% in the intervention group and 48.7% in the control group (odds ratio 1.27, 95% confidence interval 1.11 to 1.45). Testing before sex with a new partner was 39.5% in the intervention group and 40.9% in the control group (odds ratio 0.95, 95% confidence interval 0.82 to 1.10). Having two or more partners since joining the trial was 56.9% in the intervention group and 54.8% in the control group (odds ratio 1.11, 95% confidence interval 1.00 to 1.24) and having sex with someone new since joining the trial was 69.7% in the intervention group and 67.4% in the control group (odds ratio 1.13, 95% confidence interval 1.00 to 1.28). There were no differences in safety outcomes. Additional sensitivity and per-protocol analyses showed similar results.
Limitations
Our understanding of the mechanism of action for the unanticipated effects is limited.
Conclusions
The safetxt intervention did not reduce chlamydia and gonorrhoea infections, with slightly more infections in the intervention group. The intervention increased condom use but also increased the number of partners and new partners. Randomised controlled trials are essential for evaluating health communication interventions, which can have unanticipated effects.
Future work
Randomised controlled trials evaluating novel interventions in this complex area are needed.
Trial registration
This trial is registered as ISRCTN64390461.
Funding
This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 11, No. 1. See the NIHR Journals Library website for further project information.
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Affiliation(s)
- Caroline Free
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Melissa J Palmer
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Kimberley Potter
- Clinical Trials Unit, Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Ona L McCarthy
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Lauren Jerome
- Clinical Trials Unit, Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Sima Berendes
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Anasztazia Gubijev
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Megan Knight
- Clinical Trials Unit, Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Zahra Jamal
- Clinical Trials Unit, Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Farandeep Dhaliwal
- Clinical Trials Unit, Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - James R Carpenter
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Tim P Morris
- Medical Research Council Clinical Trials Unit, London, UK
| | - Phil Edwards
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Rebecca French
- Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Louis Macgregor
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Katy ME Turner
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | | | - Ford CI Hickson
- Sigma Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Kaye Wellings
- Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK
| | - Ian Roberts
- Clinical Trials Unit, Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Julia V Bailey
- eHealth Unit, Research Department of Primary Care and Population Health, University College London, London, UK
| | - Graham Hart
- Department of Infection and Population Health, University College London, London, UK
| | - Susan Michie
- Centre for Outcomes Research and Effectiveness, University College London, London, UK
| | - Tim Clayton
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Karen Devries
- Department of Medical Statistics, London School of Hygiene & Tropical Medicine, London, UK
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PacBio Amplicon Sequencing Method To Measure Pilin Antigenic Variation Frequencies of Neisseria gonorrhoeae. mSphere 2019; 4:4/5/e00562-19. [PMID: 31578246 PMCID: PMC6796969 DOI: 10.1128/msphere.00562-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Gene diversification is a common mechanism pathogens use to alter surface structures to aid in immune avoidance. Neisseria gonorrhoeae uses a gene conversion-based diversification system to alter the primary sequence of the gene encoding the major subunit of the pilus, pilE Antigenic variation occurs when one of the nonexpressed 19 silent copies donates part of its DNA sequence to pilE We have developed a method using Pacific Biosciences (PacBio) amplicon sequencing and custom software to determine pilin antigenic variation frequencies. The program analyzes 37 variable regions across the strain FA1090 1-81-S2 pilE gene and can be modified to determine sequence variation from other starting pilE sequences or other diversity generation systems. Using this method, we measured pilin antigenic variation frequencies for various derivatives of strain FA1090 and showed we can also analyze pilin antigenic variation frequencies during macrophage infection.IMPORTANCE Diversity generation systems are used by many unicellular organism to provide subpopulations of cell with different properties that are available when needed. We have developed a method using the PacBio DNA sequencing technology and a custom computer program to analyze the pilin antigenic variation system of the organism that is the sole cause of the sexually transmitted infection, gonorrhea.
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Chehrazi N, Cipriano LE, Enns EA. Dynamics of Drug Resistance: Optimal Control of an Infectious Disease. OPERATIONS RESEARCH 2019; 67:599-904. [PMID: 34113048 PMCID: PMC8188892 DOI: 10.1287/opre.2018.1817] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Antimicrobial resistance is a significant public health threat. In the U.S. alone, 2 million people are infected and 23,000 die each year from antibiotic resistant bacterial infections. In many cases, infections are resistant to all but a few remaining drugs. We examine the case where a single drug remains and solve for the optimal treatment policy for an SIS infectious disease model incorporating the effects of drug resistance. The problem is formulated as an optimal control problem with two continuous state variables, the disease prevalence and drug's "quality" (the fraction of infections that are drug-susceptible). The decision maker's objective is to minimize the discounted cost of the disease to society over an infinite horizon. We provide a new generalizable solution approach that allows us to thoroughly characterize the optimal treatment policy analytically. We prove that the optimal treatment policy is a bang-bang policy with a single switching time. The action/inaction regions can be described by a single boundary that is strictly increasing when viewed as a function of drug quality, indicating that when the disease transmission rate is constant, the policy of withholding treatment to preserve the drug for a potentially more serious future outbreak is not optimal. We show that the optimal value function and/or its derivatives are neither C 1 nor Lipschitz continuous suggesting that numerical approaches to this family of dynamic infectious disease models may not be computationally stable. Furthermore, we demonstrate that relaxing the standard assumption of constant disease transmission rate can fundamentally change the shape of the action region, add a singular arc to the optimal control, and make preserving the drug for a serious outbreak optimal. In addition, we apply our framework to the case of antibiotic resistant gonorrhea.
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Affiliation(s)
- Naveed Chehrazi
- Department of Information, Risk, and Operations Management, McCombs School of Business, The University of Texas at Austin, Austin, TX.
| | - Lauren E Cipriano
- Management Science, Ivey Business School, Western University, London, ON, Canada.
| | - Eva A Enns
- Division of Health Policy & Management, School of Public Health, University of Minnesota, Minneapolis, MN.
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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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Tuite AR, Gift TL, Chesson HW, Hsu K, Salomon JA, Grad YH. Impact of Rapid Susceptibility Testing and Antibiotic Selection Strategy on the Emergence and Spread of Antibiotic Resistance in Gonorrhea. J Infect Dis 2017; 216:1141-1149. [PMID: 28968710 PMCID: PMC5853443 DOI: 10.1093/infdis/jix450] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/29/2017] [Indexed: 12/22/2022] Open
Abstract
Background Increasing antibiotic resistance limits treatment options for gonorrhea. We examined the impact of a hypothetical point-of-care (POC) test reporting antibiotic susceptibility profiles on slowing resistance spread. Methods A mathematical model describing gonorrhea transmission incorporated resistance emergence probabilities and fitness costs associated with resistance based on characteristics of ciprofloxacin (A), azithromycin (B), and ceftriaxone (C). We evaluated time to 1% and 5% prevalence of resistant strains among all isolates with the following: (1) empiric treatment (B and C), and treatment guided by POC tests determining susceptibility to (2) A only and (3) all 3 antibiotics. Results Continued empiric treatment without POC testing was projected to result in >5% of isolates being resistant to both B and C within 15 years. Use of either POC test in 10% of identified cases delayed this by 5 years. The 3 antibiotic POC test delayed the time to reach 1% prevalence of triply-resistant strains by 6 years, whereas the A-only test resulted in no delay. Results were less sensitive to assumptions about fitness costs and test characteristics with increasing test uptake. Conclusions Rapid diagnostics reporting antibiotic susceptibility may extend the usefulness of existing antibiotics for gonorrhea treatment, but ongoing monitoring of resistance patterns will be critical.
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Affiliation(s)
- Ashleigh R Tuite
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Thomas L Gift
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Joshua A Salomon
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Yonatan H Grad
- Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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Ragland SA, Schaub RE, Hackett KT, Dillard JP, Criss AK. Two lytic transglycosylases in Neisseria gonorrhoeae impart resistance to killing by lysozyme and human neutrophils. Cell Microbiol 2016; 19. [PMID: 27597434 DOI: 10.1111/cmi.12662] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 08/04/2016] [Accepted: 08/29/2016] [Indexed: 01/01/2023]
Abstract
Symptomatic infection by Neisseria gonorrhoeae (Gc) produces a potent inflammatory response, resulting in a neutrophil-rich exudate. A population of Gc can survive the killing activities of neutrophils for reasons not completely understood. Unlike other Gram-negative bacteria, Gc releases monomeric peptidoglycan (PG) extracellularly, dependent on two nonessential, nonredundant lytic transglycosylases (LTs), LtgA and LtgD. PG released by LtgA and LtgD can stimulate host immune responses. We report that ΔltgAΔltgD Gc were decreased in survival in the presence of primary human neutrophils but otherwise grew equally to wild-type Gc. Adding PG monomer failed to alter ΔltgAΔltgD Gc survival. Thus, LTs protect Gc from neutrophils independently of monomer release. We found two reasons to explain decreased survival of the double LT mutant. First, ΔltgAΔltgD Gc was more sensitive to the neutrophil antimicrobial proteins lysozyme and neutrophil elastase, but not others. Sensitivity to lysozyme correlated with decreased Gc envelope integrity. Second, exposure of neutrophils to ΔltgAΔltgD Gc increased the release of neutrophil granule contents extracellularly and into Gc phagosomes. We conclude that LtgA and LtgD protect Gc from neutrophils by contributing to envelope integrity and limiting bacterial exposure to select granule-localized antimicrobial proteins. These observations are the first to link bacterial degradation by lysozyme to increased neutrophil activation.
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Affiliation(s)
- Stephanie A Ragland
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22908, USA
| | - Ryan E Schaub
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Kathleen T Hackett
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Joseph P Dillard
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Alison K Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22908, USA
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9
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Juneau RA, Stevens JS, Apicella MA, Criss AK. A thermonuclease of Neisseria gonorrhoeae enhances bacterial escape from killing by neutrophil extracellular traps. J Infect Dis 2015; 212:316-24. [PMID: 25605868 PMCID: PMC4490236 DOI: 10.1093/infdis/jiv031] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/08/2015] [Indexed: 12/24/2022] Open
Abstract
Acute gonorrhea is characterized by neutrophilic inflammation that is insufficient to clear Neisseria gonorrhoeae. Activated neutrophils release extracellular traps (NETs), which are composed of chromatin and decorated with antimicrobial proteins. The N. gonorrhoeae NG0969 open reading frame contains a gene (nuc) that encodes a putatively secreted thermonuclease (Nuc) that contributes to biofilm remodeling. Here, we report that Nuc degrades NETs to help N. gonorrhoeae resist killing by neutrophils. Primary human neutrophils released NETs after exposure to N. gonorrhoeae, but NET integrity declined over time with Nuc-containing bacteria. Recombinant Nuc and conditioned medium from Nuc-containing N. gonorrhoeae degraded human neutrophil DNA and NETs. NETs were found to have antimicrobial activity against N. gonorrhoeae, and Nuc expression enhanced N. gonorrhoeae survival in the presence of neutrophils that released NETs. We propose that Nuc enables N. gonorrhoeae to escape trapping and killing by NETs during symptomatic infection, highlighting Nuc as a multifunctional virulence factor for N. gonorrhoeae.
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Affiliation(s)
- Richard A. Juneau
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville
| | - Jacqueline S. Stevens
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville
| | | | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville
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Johnson MB, Ball LM, Daily KP, Martin JN, Columbus L, Criss AK. Opa+ Neisseria gonorrhoeae exhibits reduced survival in human neutrophils via Src family kinase-mediated bacterial trafficking into mature phagolysosomes. Cell Microbiol 2014; 17:648-65. [PMID: 25346239 DOI: 10.1111/cmi.12389] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 10/01/2014] [Accepted: 10/22/2014] [Indexed: 01/05/2023]
Abstract
During gonorrhoeal infection, there is a heterogeneous population of Neisseria gonorrhoeae (Gc) varied in their expression of opacity-associated (Opa) proteins. While Opa proteins are important for bacterial attachment and invasion of epithelial cells, Opa+ Gc has a survival defect after exposure to neutrophils. Here, we use constitutively Opa- and OpaD+ Gc in strain background FA1090 to show that Opa+ Gc is more sensitive to killing inside adherent, chemokine-treated primary human neutrophils due to increased bacterial residence in mature, degradative phagolysosomes that contain primary and secondary granule antimicrobial contents. Although Opa+ Gc stimulates a potent oxidative burst, neutrophil killing of Opa+ Gc was instead attributable to non-oxidative components, particularly neutrophil proteases and the bactericidal/permeability-increasing protein. Blocking interaction of Opa+ Gc with carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) or inhibiting Src family kinase signalling, which is downstream of CEACAM activation, enhanced the survival of Opa+ Gc in neutrophils. Src family kinase signalling was required for fusion of Gc phagosomes with primary granules to generate mature phagolysosomes. Conversely, ectopic activation of Src family kinases or coinfection with Opa+ Gc resulted in decreased survival of Opa- Gc in neutrophils. From these results, we conclude that Opa protein expression is an important modulator of Gc survival characteristics in neutrophils by influencing phagosome dynamics and thus bacterial exposure to neutrophils' full antimicrobial arsenal.
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Affiliation(s)
- M Brittany Johnson
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
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11
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Contrasting within- and between-host immune selection shapes Neisseria Opa repertoires. Sci Rep 2014; 4:6554. [PMID: 25296566 PMCID: PMC4894414 DOI: 10.1038/srep06554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 09/08/2014] [Indexed: 11/30/2022] Open
Abstract
Pathogen evolution is influenced strongly by the host immune response. Previous studies of the effects of herd immunity on the population structure of directly transmitted, short-lived pathogens have primarily focused on the impact of competition for hosts. In contrast, for long-lived infections like HIV, theoretical work has focused on the mechanisms promoting antigenic variation within the host. In reality, successful transmission requires that pathogens balance both within- and between-host immune selection. The Opa adhesins in the bacterial Neisseria genus provide a unique system to study the evolution of the same antigens across two major pathogens: while N. meningitidis is an airborne, respiratory pathogen colonising the nasopharynx relatively transiently, N. gonorrhoeae can cause sexually transmitted, long-lived infections. We use a simple mathematical model and genomic data to show that trade-offs between immune selection pressures within- and between-hosts can explain the contrasting Opa repertoires observed in meningococci and gonococci.
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Assembly of NADPH oxidase in human neutrophils is modulated by the opacity-associated protein expression State of Neisseria gonorrhoeae. Infect Immun 2013; 82:1036-44. [PMID: 24343654 DOI: 10.1128/iai.00881-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neisseria gonorrhoeae (the gonococcus, Gc) triggers a potent inflammatory response and recruitment of neutrophils to the site of infection. Gc survives exposure to neutrophils despite these cells' antimicrobial products, such as reactive oxygen species (ROS). ROS production in neutrophils is initiated by NADPH oxidase, which converts oxygen into superoxide. The subunits of NADPH oxidase are spatially separated between granules (gp91(phox)/p22(phox)) and the cytoplasm (p47(phox), p67(phox), and p40(phox)). Activation of neutrophils promotes the coassembly of NADPH oxidase subunits at phagosome and/or plasma membranes. While Gc-expressing opacity-associated (Opa) proteins can induce neutrophils to produce ROS, Opa-negative (Opa-) Gc does not stimulate neutrophil ROS production. Using constitutively Opa- and OpaD-positive (OpaD+) Gc bacteria in strain FA1090, we now show that the difference in ROS production levels in primary human neutrophils between these backgrounds can be attributed to differential assembly of NADPH oxidase. Neutrophils infected with Opa- Gc showed limited translocation of NADPH oxidase cytoplasmic subunits to cellular membranes, including the bacterial phagosome. In contrast, these subunits rapidly translocated to neutrophil membranes following infection with OpaD+ Gc. gp91(phox) and p22(phox) were recruited to Gc phagosomes regardless of bacterial Opa expression. These results suggest that Opa- Gc interferes with the recruitment of neutrophil NADPH oxidase cytoplasmic subunits to membranes, in particular, the p47(phox) "organizing" subunit, to prevent assembly of the holoenzyme, resulting in an absence of the oxidative burst.
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Sexually transmitted infections among US women and men: prevalence and incidence estimates, 2008. Sex Transm Dis 2013; 40:187-93. [PMID: 23403598 DOI: 10.1097/olq.0b013e318286bb53] [Citation(s) in RCA: 928] [Impact Index Per Article: 84.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Most sexually active people will be infected with a sexually transmitted infection (STI) at some point in their lives. The number of STIs in the United States was previously estimated in 2000. We updated previous estimates to reflect the number of STIs for calendar year 2008. METHODS We reviewed available data and literature and conservatively estimated incident and prevalent infections nationally for 8 common STIs: chlamydia, gonorrhea, syphilis, herpes, human papillomavirus, hepatitis B, HIV, and trichomoniasis. Where available, data from nationally representative surveys such as the National Health and Nutrition Examination Survey were used to provide national estimates of STI prevalence or incidence. The strength of each estimate was rated good, fair, or poor, according to the quality of the evidence. RESULTS In 2008, there were an estimated 110 million prevalent STIs among women and men in the United States. Of these, more than 20% of infections (22.1 million) were among women and men aged 15 to 24 years. Approximately 19.7 million incident infections occurred in the United States in 2008; nearly 50% (9.8 million) were acquired by young women and men aged 15 to 24 years. Human papillomavirus infections, many of which are asymptomatic and do not cause disease, accounted for most of both prevalent and incident infections. CONCLUSIONS Sexually transmitted infections are common in the United States, with a disproportionate burden among young adolescents and adults. Public health efforts to address STIs should focus on prevention among at-risk populations to reduce the number and impact of STIs.
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Johnson MB, Criss AK. Neisseria gonorrhoeae phagosomes delay fusion with primary granules to enhance bacterial survival inside human neutrophils. Cell Microbiol 2013; 15:1323-40. [PMID: 23374609 PMCID: PMC3713093 DOI: 10.1111/cmi.12117] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 01/11/2013] [Accepted: 01/27/2013] [Indexed: 12/21/2022]
Abstract
Symptomatic infection with Neisseria gonorrhoeae (Gc) promotes inflammation driven by polymorphonuclear leucocytes (PMNs, neutrophils), yet some Gc survive PMN exposure during infection. Here we report a novel mechanism of gonococcal resistance to PMNs: Gc phagosomes avoid maturation into phagolysosomes by delayed fusion with primary (azurophilic) granules, which contain antimicrobial components including serine proteases. Reduced phagosome-primary granule fusion was observed in gonorrheal exudates and human PMNs infected ex vivo. Delayed phagosome-granule fusion could be overcome by opsonizing Gc with immunoglobulin. Using bacterial viability dyes along with antibodies to primary granules revealed that Gc survival in PMNs correlated with early residence in primary granule-negative phagosomes. However, when Gc was killed prior to PMN exposure, dead bacteria were also found in primary granule-negative phagosomes. These results suggest that Gc surface characteristics, rather than active bacterial processes, influence phagosome maturation and that Gc death inside PMNs occurs after phagosome-granule fusion. Ectopically increasing primary granule-phagosome fusion, by immunoglobulin opsonization or PMN treatment with lysophosphatidylcholine, reduced intracellular Gc viability, which was attributed in part to serine protease activity. We conclude that one method for Gc to avoid PMN clearance in acute gonorrhoea is by delaying primary granule-phagosome fusion, thus preventing formation of a degradative phagolysosome.
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Affiliation(s)
- M. Brittany Johnson
- Department of Microbiology, Immunology, and Cancer Biology, 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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A bacterial siren song: intimate interactions between Neisseria and neutrophils. Nat Rev Microbiol 2012; 10:178-90. [PMID: 22290508 DOI: 10.1038/nrmicro2713] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neisseria gonorrhoeae and Neisseria meningitidis are Gram-negative bacterial pathogens that are exquisitely adapted for growth at human mucosal surfaces and for efficient transmission between hosts. One factor that is essential to neisserial pathogenesis is the interaction between the bacteria and neutrophils, which are recruited in high numbers during infection. Although this vigorous host response could simply reflect effective immune recognition of the bacteria, there is mounting evidence that in fact these obligate human pathogens manipulate the innate immune response to promote infectious processes. This Review summarizes the mechanisms used by pathogenic neisseriae to resist and modulate the antimicrobial activities of neutrophils. It also details some of the major outstanding questions about the Neisseria-neutrophil relationship and proposes potential benefits of this relationship for the pathogen.
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The Incidence and Correlates of Symptomatic and Asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae Infections in Selected Populations in Five Countries. Sex Transm Dis 2011. [DOI: 10.1097/olq.0b013e318206c288] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Johnson MB, Criss AK. Resistance of Neisseria gonorrhoeae to neutrophils. Front Microbiol 2011; 2:77. [PMID: 21747795 PMCID: PMC3128980 DOI: 10.3389/fmicb.2011.00077] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/31/2011] [Indexed: 01/04/2023] Open
Abstract
Infection with the human-specific bacterial pathogen Neisseria gonorrhoeae triggers a potent, local inflammatory response driven by polymorphonuclear leukocytes (neutrophils or PMNs). PMNs are terminally differentiated phagocytic cells that are a vital component of the host innate immune response and are the first responders to bacterial and fungal infections. PMNs possess a diverse arsenal of components to combat microorganisms, including the production of reactive oxygen species and release of degradative enzymes and antimicrobial peptides. Despite numerous PMNs at the site of gonococcal infection, N. gonorrhoeae can be cultured from the PMN-rich exudates of individuals with acute gonorrhea, indicating that some bacteria resist killing by neutrophils. The contribution of PMNs to gonorrheal pathogenesis has been modeled in vivo by human male urethral challenge and murine female genital inoculation and in vitro using isolated primary PMNs or PMN-derived cell lines. These systems reveal that some gonococci survive and replicate within PMNs and suggest that gonococci defend themselves against PMNs in two ways: they express virulence factors that defend against PMNs' oxidative and non-oxidative antimicrobial components, and they modulate the ability of PMNs to phagocytose gonococci and to release antimicrobial components. In this review, we will highlight the varied and complementary approaches used by N. gonorrhoeae to resist clearance by human PMNs, with an emphasis on gonococcal gene products that modulate bacterial-PMN interactions. Understanding how some gonococci survive exposure to PMNs will help guide future initiatives for combating gonorrheal disease.
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Affiliation(s)
| | - Alison K. Criss
- Department of Microbiology, University of VirginiaCharlottesville, VA, USA
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Abstract
This review addresses the occurrence, the trends, and the risk groups of Neisseria gonorrhoeae in Europe over the past decade. A decline has been observed in most of Europe since the 1980s, except for an increase in the Baltic countries (early 1990s) and an increase among men who have sex with men (between 1989 and 1991), and heterosexuals in some countries (between 1995 and 1997). Despite the overall fall in the incidence of gonorrhoea, plasmid-mediated resistance to penicillin and tetracycline increased in Europe. More recently, resistance to fluoroquinolones has been documented, mainly imported from Southeast Asia. Until now, no resistance to third-generation cephalosporins has been observed.
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Affiliation(s)
- Y T van Duynhoven
- Department of Infectious Diseases Epidemiology, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
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Kretzschmar M, Jager JC, Reinking DP, Van Zessen G, Brouwers H. The basic reproduction ratio R0 for a sexually transmitted disease in a pair formation model with two types of pairs. Math Biosci 1994; 124:181-205. [PMID: 7833594 DOI: 10.1016/0025-5564(94)90042-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We study a model for pair formation and separation with two types of pairs which differ in average duration. A fraction f of all newly formed pairs have a long duration (denoted by "steady"), the remaining fraction 1-f have a short duration ("casual"). This distinction is motivated by data about the survival times of partnerships in a sociological survey. In this population we consider a sexually transmitted disease, which can have different transmission rates in steady and in causal partnerships. We investigate under which conditions an epidemic can occur after introduction of the disease into a population where the process of pair formation and separation is at equilibrium. If there is no recovery we can compute an explicit expression for the basic reproduction ratio R0; if we take recovery into account we can derive a condition for the stability of the disease-free equilibrium which is equivalent to R0 < 1. We discuss how R0 depends on various model parameters.
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Affiliation(s)
- M Kretzschmar
- National Institute of Public Health and Environmental Protection (RIVM), Bilthoven, The Netherlands
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Weyer J, Eggers HJ. On the structure of the epidemic spread of AIDS: the influence of an infectious coagent. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1990; 273:52-67. [PMID: 2194486 DOI: 10.1016/s0934-8840(11)80239-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The reported AIDS cases in the USA and the Federal Republic of Germany are growing almost exponentially. Considering the epidemiological curves for different risk groups (homosexual men, i.v. drug abusers, heterosexual partners etc.) it is extremely surprising, that nearly exactly the same development occurs in all risk groups. One only has to consider a certain time shift for each group. The conformity of the development for all groups is evident by the fact, that the curves representing the reported AIDS cases for different risk groups are straight lines (in a logarithmic scale) running nearly exactly in parallel. This remarkable parallelism can be understood only if the spread of AIDS is independent of the sexual or drug risk in a certain sense. On the other hand, the drastic overrepresentation of the sexually highly active groups and drug abusers in the number of AIDS cases obviously requires that the transmission of AIDS unequivocally depends on the sexual and drug risk. We present a mathematical model that is suitable to reconcile this apparent contradiction in the interpretation of the epidemiological data: the observed parallel time series for the spread of AIDS in groups with different risk of infection can be realized by computer simulation, if one assumes that the outbreak of full-blown AIDS only occurs if HIV and a certain infectious coagent (cofactor) CO are present. Such a situation is not uncommon, see, e.g. the influenza virus--Staphylococcus aureus system. According to the mathematical model this cofactor would spread independently of the sexual and drug risk--in contrast to HIV. However, due to its analytical properties the simulated cofactor cannot be identified so far with any known infectious agent.
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Affiliation(s)
- J Weyer
- Mathematisches Institut, Universität zu Köln
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Péc J, Moravcík P, Kliment J, Fetisov I. Isolation of Neisseria gonorrhoeae from urine obtained by suprapubic puncture of bladders of men with gonococcal urethritis. Genitourin Med 1988; 64:156-8. [PMID: 3137150 PMCID: PMC1194188 DOI: 10.1136/sti.64.3.156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The authors examined three urine specimens from each of 24 men with acute gonococcal urethritis. Gonococcal concentrations in urine were 7 X 10(3)/ml to 9 X 10(8)/ml in first samples, 1 X 10(2)/ml to 5 X 10(6)/ml in midstream samples, and, in the terminal samples from only 22 men, 8 X 10(4)/ml. A further 17 men with symptomless gonococcal urethritis were examined. Seven of them yielded 1 X 10(2)/ml to 2.5 X 10(5)/ml in first samples and 5 X 10(5)/ml in midstream samples, and only two yielded 5 X 10(1)/ml in final samples. All 24 men with acute gonococcal urethritis, and seven of the men with symptomless gonococcal urethritis who had yielded N gonorrhoeae in midstream urine samples, were examined by suprapubic puncture before morning voiding. Four of the 24 men with acute gonococcal urethritis were found to have infection that had ascended into the bladder.
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Affiliation(s)
- J Péc
- Department of Dermatovenereology, Faculty of Medicine, Comenius University, Martin, Czechoslovakia
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Rodríguez J, Fuxench-Chiesa Z, Ramírez-Ronda CH, Kouri Y, Cuevas R, Nevárez M, Pérez M. In vitro susceptibility of 50 non-beta-lactamase-producing Neisseria gonorrhoeae strains to 12 antimicrobial agents. Antimicrob Agents Chemother 1983; 23:242-4. [PMID: 6404217 PMCID: PMC186029 DOI: 10.1128/aac.23.2.242] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The in vitro activities of six commonly used antibiotics and six newer beta-lactam agents were determined in 50 consecutive clinical isolates of beta-lactamase-negative Neisseria gonorrhoeae. The gonococci isolated were notably resistant to penicillin, ampicillin, erythromycin, and tetracycline, whereas all of the strains were susceptible to the newer beta-lactam agents cefoxitin and spectinomycin.
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