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Getahun Strobel A, Hayes AJ, Wirth W, Mua M, Saumalua T, Cabenatabua O, Soqo V, Rosa V, Wang N, Lacey JA, Hocking D, Valcanis M, Jenney A, Howden BP, Duchene S, Mulholland K, Strugnell RA, Davies MR. Genetic heterogeneity in the Salmonella Typhi Vi capsule locus: a population genomic study from Fiji. Microb Genom 2024; 10. [PMID: 39254668 PMCID: PMC11385387 DOI: 10.1099/mgen.0.001288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2024] Open
Abstract
Typhoid fever is endemic in many parts of the world and remains a major public health concern in tropical and sub-tropical developing nations, including Fiji. To address high rates of typhoid fever, the Northern Division of Fiji implemented a mass vaccination with typhoid conjugate vaccine (Vi-polysaccharide conjugated to tetanus toxoid) as a public health control measure in 2023. In this study we define the genomic epidemiology of Salmonella Typhi in the Northern Division prior to island-wide vaccination, sequencing 85% (n=419) of the total cases from the Northern and Central Divisions of Fiji that occurred in the period 2017-2019. We found elevated rates of nucleotide polymorphisms in the tviD and tviE genes (responsible for Vi-polysaccharide synthesis) relative to core genome levels within the Fiji endemic S. Typhi genotype 4.2. Expansion of these findings within a globally representative database of 12 382 S. Typhi (86 genotyphi clusters) showed evidence of convergent evolution of the same tviE mutations across the S. Typhi population, indicating that tvi selection has occurred both independently and globally. The functional impact of tvi mutations on the Vi-capsular structure and other phenotypic characteristics are not fully elucidated, yet commonly occurring tviE polymorphisms localize adjacent to predicted active site residues when overlayed against the predicted TviE protein structure. Given the central role of the Vi-polysaccharide in S. Typhi biology and vaccination, further integrated epidemiological, genomic and phenotypic surveillance is required to determine the spread and functional implications of these mutations.
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Affiliation(s)
- Aneley Getahun Strobel
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- College of Medicine and Health Sciences, Fiji National University, Suva, Fiji
| | - Andrew J Hayes
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Wytamma Wirth
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- 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, Victoria, Australia
| | - Mikaele Mua
- Labasa Divisional Hospital, Fiji Ministry of Health, and Medical Services, Labasa, Fiji
| | - Tiko Saumalua
- Northern Health, Fiji Ministry of Health, and Medical Services, Labasa, Fiji
| | - Orisi Cabenatabua
- Labasa Divisional Hospital, Fiji Ministry of Health, and Medical Services, Labasa, Fiji
| | - Vika Soqo
- Labasa Divisional Hospital, Fiji Ministry of Health, and Medical Services, Labasa, Fiji
| | - Varanisese Rosa
- New Vaccines Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Nancy Wang
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Jake A Lacey
- 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, Victoria, Australia
| | - Dianna Hocking
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mary Valcanis
- 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, Victoria, Australia
| | - Adam Jenney
- College of Medicine and Health Sciences, Fiji National University, Suva, Fiji
- New Vaccines Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Benjamin P Howden
- 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, Victoria, Australia
- Centre for Pathogen Genomics, The University of Melbourne, Melbourne, Victoria, Australia
| | - Sebastian Duchene
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- London School of Hygiene and Tropical Medicine, London, UK
| | - Kim Mulholland
- Department of Computational Biology, Institut Pasteur, Paris, France
- New Vaccines Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Richard A Strugnell
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
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2
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McCann N, Paganotti Vicentine M, Kim YC, Pollard AJ. The use of controlled human infection models to identify correlates of protection for invasive Salmonella vaccines. Front Immunol 2024; 15:1457785. [PMID: 39257585 PMCID: PMC11385307 DOI: 10.3389/fimmu.2024.1457785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Accepted: 08/08/2024] [Indexed: 09/12/2024] Open
Abstract
Controlled human infection model (CHIM) studies, which involve deliberate exposure of healthy human volunteers to an infectious agent, are recognised as important tools to advance vaccine development. These studies not only facilitate estimates of vaccine efficacy, but also offer an experimental approach to study disease pathogenesis and profile vaccine immunogenicity in a controlled environment, allowing correlation with clinical outcomes. Consequently, the data from CHIMs can be used to identify immunological correlates of protection (CoP), which can help accelerate vaccine development. In the case of invasive Salmonella infections, vaccination offers a potential instrument to prevent disease. Invasive Salmonella disease, caused by the enteric fever pathogens Salmonella enterica serovar Typhi (S. Typhi) and S. Paratyphi A, B and C, and nontyphoidal Salmonella (iNTS), remains a significant cause of mortality and morbidity in low- and middle-income countries, resulting in over 200,000 deaths and the loss of 15 million DALYs annually. CHIM studies have contributed to the understanding of S. Typhi infection and provided invaluable insight into the development of vaccines and CoP following vaccination against S. Typhi. However, CoP are less well understood for S. Paratyphi A and iNTS. This brief review focuses on the contribution of vaccine-CHIM trials to our understanding of the immune mechanisms associated with protection following vaccines against invasive Salmonella pathogens, particularly in relation to CoP.
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Affiliation(s)
- Naina McCann
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Margarete Paganotti Vicentine
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Young Chan Kim
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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3
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Barton A, Hill J, O'Connor D, Jones C, Jones E, Camara S, Shrestha S, Jin C, Gibani MM, Dobinson HC, Waddington C, Darton TC, Blohmke CJ, Pollard AJ. Early transcriptional responses to human enteric fever challenge. Infect Immun 2023; 91:e0010823. [PMID: 37725060 PMCID: PMC10581002 DOI: 10.1128/iai.00108-23] [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: 03/23/2023] [Accepted: 06/29/2023] [Indexed: 09/21/2023] Open
Abstract
Enteric fever, caused by oral infection with typhoidal Salmonella serovars, presents as a non-specific febrile illness preceded by an incubation period of 5 days or more. The enteric fever human challenge model provides a unique opportunity to investigate the innate immune response during this incubation period, and how this response is altered by vaccination with the Vi polysaccharide or conjugate vaccine. We find that on the same day as ingestion of typhoidal Salmonella, there is already evidence of an immune response, with 199 genes upregulated in the peripheral blood transcriptome 12 hours post-challenge (false discovery rate <0.05). Gene sets relating to neutrophils, monocytes, and innate immunity were over-represented (false discovery rate <0.05). Estimating cell proportions from gene expression data suggested a possible increase in activated monocytes 12 hours post-challenge (P = 0.036, paired Wilcoxon signed-rank test). Furthermore, plasma TNF-α rose following exposure (P = 0.011, paired Wilcoxon signed-rank test). There were no significant differences in gene expression (false discovery rate <0.05) in the 12 hours response between those who did and did not subsequently develop clinical or blood culture confirmed enteric fever or between vaccination groups. Together, these results demonstrate early perturbation of the peripheral blood transcriptome after enteric fever challenge and provide initial insight into early mechanisms of protection.
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Affiliation(s)
- Amber Barton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Jennifer Hill
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Daniel O'Connor
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Elizabeth Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Susana Camara
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Sonu Shrestha
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Celina Jin
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
- Department of Pathology, Royal Melbourne Hospital, Melbourne, Australia
- Infectious Diseases and Immune Defence Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Malick M. Gibani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
- Department of Infectious Disease, Imperial College, London, United Kingdom
| | - Hazel C. Dobinson
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Claire Waddington
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
- Department of Infectious Disease, Imperial College, London, United Kingdom
| | - Thomas C. Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
- Department of Infection, Immunity and Cardiovascular Disease and The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, United Kingdom
| | - Christoph J. Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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4
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Cross AS. Hit 'em Where It Hurts: Gram-Negative Bacterial Lipopolysaccharide as a Vaccine Target. Microbiol Mol Biol Rev 2023; 87:e0004522. [PMID: 37432116 PMCID: PMC10521362 DOI: 10.1128/mmbr.00045-22] [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] [Indexed: 07/12/2023] Open
Abstract
Infections with antimicrobial-resistant (AMR) bacteria pose an increasing threat to the ability to perform surgical procedures, organ transplantation, and treat cancer among many other medical conditions. There are few new antimicrobials in the development pipeline. Vaccines against AMR Gram-negative bacteria may reduce the use of antimicrobials and prevent bacterial transmission. This review traces the origins of lipopolysaccharide (LPS)-based vaccines against Gram-negative bacteria, the role of O polysaccharides and LPS core regions as potential vaccine targets, the development of new vaccine technologies, and their application to vaccines in current development.
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Affiliation(s)
- Alan S. Cross
- Center for Vaccine Development and Global Health, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
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5
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Nag R, Russell L, Nolan S, Auer A, Markey BK, Whyte P, O'Flaherty V, Bolton D, Fenton O, Richards KG, Cummins E. Quantitative microbial risk assessment associated with ready-to-eat salads following the application of farmyard manure and slurry or anaerobic digestate to arable lands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151227. [PMID: 34715220 DOI: 10.1016/j.scitotenv.2021.151227] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Farmyard manure and slurry (FYM&S) and anaerobic digestate are potentially valuable soil conditioners providing important nutrients for plant development and growth. However, these organic fertilisers may pose a microbial health risk to humans. A quantitative microbial risk assessment (QMRA) model was developed to investigate the potential human exposure to pathogens following the application of FYM&S and digestate to agricultural land. The farm-to-fork probabilistic model investigated the fate of microbial indicators (total coliforms and enterococci) and foodborne pathogens in the soil with potential contamination of ready-to-eat salads (RTEs) at the point of human consumption. The processes examined included pathogen inactivation during mesophilic anaerobic digestion (M-AD), post-AD pasteurisation, storage, dilution while spreading, decay in soil, post-harvest washing processes, and finally, the potential growth of the pathogen during refrigeration/storage at the retail level in the Irish context. The QMRA highlighted a very low annual probability of risk (Pannual) due to Clostridium perfringens, norovirus, and Salmonella Newport across all scenarios. Mycobacterium avium may result in a very high mean Pannual for the application of raw FYM&S, while Cryptosporidium parvum and pathogenic E. coli showed high Pannual, and Listeria monocytogenes displayed moderate Pannual for raw FYM&S application. The use of AD reduces this risk; however, pasteurisation reduces the Pannual to an even greater extent posing a very low risk. An overall sensitivity analysis revealed that mesophilic-AD's inactivation effect is the most sensitive parameter of the QMRA, followed by storage and the decay on the field (all negatively correlated to risk estimate). The information generated from this model can help to inform guidelines for policymakers on the maximum permissible indicator or pathogen contamination levels in the digestate. The QMRA can also provide the AD industry with a safety assessment of pathogenic organisms resulting from the digestion of FYM&S.
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Affiliation(s)
- Rajat Nag
- University College Dublin, School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
| | - Lauren Russell
- Teagasc, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland; University College Dublin, School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Stephen Nolan
- National University of Ireland Galway, School of Natural Sciences and Ryan Institute, Galway, Ireland.
| | - Agathe Auer
- University College Dublin, School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Bryan K Markey
- University College Dublin, School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Paul Whyte
- University College Dublin, School of Veterinary Medicine, Belfield, Dublin 4, Ireland.
| | - Vincent O'Flaherty
- National University of Ireland Galway, School of Natural Sciences and Ryan Institute, Galway, Ireland.
| | - Declan Bolton
- Teagasc, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
| | - Owen Fenton
- Teagasc, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Karl G Richards
- Teagasc, Environment Research Centre, Johnstown Castle, County Wexford, Ireland.
| | - Enda Cummins
- University College Dublin, School of Biosystems and Food Engineering, Belfield, Dublin 4, Ireland.
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6
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Gao T, Xu P, Chen R, Wang XC, Dzakpasu M. Environmental risk assessment by using disability adjusted life year via constructing of a generalized linear model for morbidity estimation of waterborne pathogens. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 299:113566. [PMID: 34425498 DOI: 10.1016/j.jenvman.2021.113566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 06/13/2023]
Abstract
The Environmental burden of disease (EBD) quantitatively evaluates the health impacts of pathogens by using the disability-adjusted life year (DALY) method. The life loss due to morbidity is a general expression for the EBD outcome and, thus, morbidity analysis is indispensable. Considering the deficiency of previous morbidity analysis methods, the objective of this study was to construct a linear morbidity model by using a generalized linear model (GLM) as a template and introducing exposure dose, pathogen toxicity and human immunity as impact variables. Human experimental data were collected for model fitting, and the results indicated a good fit of the majority of the pathogen data. Consequently, two practical cases of water reuse in Xi'an Siyuan University (Case 1) and Lake Cui, Kunming (Case 2) were selected for model validation. Results for case 1 indicated the major EBD to be attributed to rotaviruses (5.57 × 10-7 DALYs, 95% confidence interval (CI): 4.46 × 10-7-1.72 × 10-4 DALYs) and sprinkling irrigation (5.12 × 10-7 DALYs, 95% CI: 1.95 × 10-7-1.47 × 101 DALYs). Conversely, that for case 2 is mainly attributed to noroviruses (1.42 × 10-7 DALYs, 95% CI: 7.51 × 10-11-2.67 × 10-4 DALYs) and road flushing (1.62 × 10-7 DALYs, 95% CI: 1.16 × 10-7-2.67 × 10-4 DALYs). However, comparison with the suggested threshold of 10-6 DALYs indicated the EBDs for both cases are acceptable and, thus, water reuse is confirmed to be safe. The methodology for morbidity modelling proposed in this research can effectively compensate for missing data in DALY calculation and, thereby, help to optimize the process for EBD evaluation.
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Affiliation(s)
- Tingting Gao
- School of Environmental and Chemical Engineering, Xi'an Polytechnic University, No.19 South Jinhua Road, Xi'an, 710048, PR China; International S&T Cooperation Centre for Urban Alternative Water Resources Development, Key Lab of Environmental Engineering, Shaanxi Province, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an, 710055, PR China.
| | - Pengcheng Xu
- International S&T Cooperation Centre for Urban Alternative Water Resources Development, Key Lab of Environmental Engineering, Shaanxi Province, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an, 710055, PR China
| | - Rong Chen
- International S&T Cooperation Centre for Urban Alternative Water Resources Development, Key Lab of Environmental Engineering, Shaanxi Province, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an, 710055, PR China
| | - Xiaochang C Wang
- International S&T Cooperation Centre for Urban Alternative Water Resources Development, Key Lab of Environmental Engineering, Shaanxi Province, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an, 710055, PR China
| | - Mawuli Dzakpasu
- International S&T Cooperation Centre for Urban Alternative Water Resources Development, Key Lab of Environmental Engineering, Shaanxi Province, Xi'an University of Architecture and Technology, No.13 Yanta Road, Xi'an, 710055, PR China
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7
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Cao Y, Karthikeyan AS, Ramanujam K, Raju R, Krishna S, Kumar D, Ryckman T, Mohan VR, Kang G, John J, Andrews JR, Lo NC. Geographic Pattern of Typhoid Fever in India: A Model-Based Estimate of Cohort and Surveillance Data. J Infect Dis 2021; 224:S475-S483. [PMID: 35238365 PMCID: PMC8892532 DOI: 10.1093/infdis/jiab187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Typhoid fever remains a major public health problem in India. Recently, the Surveillance for Enteric Fever in India program completed a multisite surveillance study. However, data on subnational variation in typhoid fever are needed to guide the introduction of the new typhoid conjugate vaccine in India. METHODS We applied a geospatial statistical model to estimate typhoid fever incidence across India, using data from 4 cohort studies and 6 hybrid surveillance sites from October 2017 to March 2020. We collected geocoded data from the Demographic and Health Survey in India as predictors of typhoid fever incidence. We used a log linear regression model to predict a primary outcome of typhoid incidence. RESULTS We estimated a national incidence of typhoid fever in India of 360 cases (95% confidence interval [CI], 297-494) per 100 000 person-years, with an annual estimate of 4.5 million cases (95% CI, 3.7-6.1 million) and 8930 deaths (95% CI, 7360-12 260), assuming a 0.2% case-fatality rate. We found substantial geographic variation of typhoid incidence across the country, with higher incidence in southwestern states and urban centers in the north. CONCLUSIONS There is a large burden of typhoid fever in India with substantial heterogeneity across the country, with higher burden in urban centers.
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Affiliation(s)
- Yanjia Cao
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | | | | | - Reshma Raju
- Wellcome Research Unit, Christian Medical College, Vellore, India
| | - Swathi Krishna
- Wellcome Research Unit, Christian Medical College, Vellore, India
| | - Dilesh Kumar
- Wellcome Research Unit, Christian Medical College, Vellore, India
| | - Theresa Ryckman
- Center for Health Policy and the Center for Primary Care and Outcomes Research, Stanford University School of Medicine, Stanford, California, USA
| | | | - Gagandeep Kang
- Wellcome Research Unit, Christian Medical College, Vellore, India
| | - Jacob John
- Department of Community Health, Christian Medical College, Vellore, India
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Nathan C Lo
- Deparment of Medicine, University of California, San Francisco, San Francisco, California, USA
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8
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Foster N, Tang Y, Berchieri A, Geng S, Jiao X, Barrow P. Revisiting Persistent Salmonella Infection and the Carrier State: What Do We Know? Pathogens 2021; 10:1299. [PMID: 34684248 PMCID: PMC8537056 DOI: 10.3390/pathogens10101299] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022] Open
Abstract
One characteristic of the few Salmonella enterica serovars that produce typhoid-like infections is that disease-free persistent infection can occur for months or years in a small number of individuals post-convalescence. The bacteria continue to be shed intermittently which is a key component of the epidemiology of these infections. Persistent chronic infection occurs despite high levels of circulating specific IgG. We have reviewed the information on the basis for persistence in S. Typhi, S. Dublin, S. Gallinarum, S. Pullorum, S. Abortusovis and also S. Typhimurium in mice as a model of persistence. Persistence appears to occur in macrophages in the spleen and liver with shedding either from the gall bladder and gut or the reproductive tract. The involvement of host genetic background in defining persistence is clear from studies with the mouse but less so with human and poultry infections. There is increasing evidence that the organisms (i) modulate the host response away from the typical Th1-type response normally associated with immune clearance of an acute infection to Th2-type or an anti-inflammatory response, and that (ii) the bacteria modulate transformation of macrophage from M1 to M2 type. The bacterial factors involved in this are not yet fully understood. There are early indications that it might be possible to remodulate the response back towards a Th1 response by using cytokine therapy.
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Affiliation(s)
- Neil Foster
- SRUC Aberdeen Campus, Craibstone Estate, Ferguson Building, Aberdeen AB21 9YA, UK
| | - Ying Tang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518055, China;
| | - Angelo Berchieri
- Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Univ Estadual Paulista, Via de Acesso Paulo Donato Castellane, s/n, 14884-900 Jaboticabal, SP, Brazil;
| | - Shizhong Geng
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (S.G.); (X.J.)
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (S.G.); (X.J.)
| | - Paul Barrow
- School of Veterinary Medicine, University of Surrey, Daphne Jackson Road, Guildford GU2 7AL, UK;
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9
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Gong Y, Li J, Zhu D, Wang S, Xu Y, Li Y, Wang Y, Song Y, Liu W, Tian Y. Case Report: Near-Fatal Intestinal Hemorrhage and Acute Acalculous Cholecystitis due to Vi-Negative and Fluoroquinolone-Insensitive Salmonella enterica Serovar Typhi Infection: A Rare Entity. Front Med (Lausanne) 2021; 8:666643. [PMID: 34447758 PMCID: PMC8383206 DOI: 10.3389/fmed.2021.666643] [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: 02/10/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
Typhoid fever is usually a mild clinical disease. Typhoid fever with massive intestinal hemorrhage is rare in the antibiotic era. Acute acalculous cholecystitis (AAC) is also rare in adults. Here, we describe the first adult case of typhoid fever with both complications due to Vi-negative and fluoroquinolone-insensitive Salmonella enterica serovar Typhi (S. Typhi) infection. We aim to alert physicians to this rare condition.
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Affiliation(s)
- Yuehua Gong
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Jianlin Li
- Department of Radiology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Dongnan Zhu
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Songsong Wang
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Yingchun Xu
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Yan Li
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Yanqing Wang
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Yan Song
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Wenjuan Liu
- Yantai Center for Disease Control and Prevention, Yantai, China
| | - Yunlong Tian
- Yantai Center for Disease Control and Prevention, Yantai, China
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10
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Graham DY. Helicobacter pylori. Curr Top Microbiol Immunol 2021. [PMID: 34224014 DOI: 10.1007/82_2021_235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Helicobacter pylori (H. pylori) is an important human pathogen etiologically associated with peptic ulcers and gastric cancer. The infection is present in approximately one-half of the world's population. Population-based H. pylori eradiation has confirmed that cure or prevention of the infection produces a marked reduction in gastric cancer and peptic ulcer disease. Antimicrobial therapy has become increasingly ineffective, and complexity and costs of antimicrobial therapy for infected individuals residing in and, immigrating from, the developing world combined with the cost of treatment for cancer make vaccine development a cost-effective alternative. Challenge studies allowed making a "go-no go" decision regarding vaccine effectiveness. We provide detailed protocols regarding challenge strain selection and administration as well as guidance regarding the clinical and laboratory tests used to confirm and monitor experimental infection. Experience shows that reliance of noninvasive methods led to the erroneous conclusion that some subjects were not infected. The current data suggests that histologic assessment of gastric mucosal biopsies may be one of the most sensitive and specific means of assessment of the presence of experimental infection as well as of successful H. pylori eradication. We recommend detailed recommendations for acquiring, processing, embedding, sectioning, and examining the gastric biopsies.
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Affiliation(s)
- David Y Graham
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, RM 3A-390A (111D), 2002 Holcombe Boulevard, Houston, TX, 77030, USA.
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11
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Acosta-Alonzo CB, Erovenko IV, Lancaster A, Oh H, Rychtář J, Taylor D. High endemic levels of typhoid fever in rural areas of Ghana may stem from optimal voluntary vaccination behaviour. Proc Math Phys Eng Sci 2020; 476:20200354. [PMID: 33071586 PMCID: PMC7544331 DOI: 10.1098/rspa.2020.0354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/04/2020] [Indexed: 01/24/2023] Open
Abstract
Typhoid fever has long established itself endemically in rural Ghana despite the availability of cheap and effective vaccines. We used a game-theoretic model to investigate whether the low vaccination coverage in Ghana could be attributed to rational human behaviour. We adopted a version of an epidemiological model of typhoid fever dynamics, which accounted not only for chronic life-long carriers but also for a short-cycle transmission in the immediate environment and a long-cycle transmission via contamination of the water supply. We calibrated the model parameters based on the known incidence data. We found that unless the (perceived) cost of vaccination is negligible, the individually optimal population vaccination rate falls significantly short of the societally optimal population vaccination rate needed to reach herd immunity. We expressed both the herd immunity and the optimal equilibrium vaccination rates in terms of only a few observable parameters such as the incidence rate, demographics, vaccine waning rate and the perceived cost of vaccination relative to the cost of infection. This allowed us not to rely on other uncertain epidemiological model parameters and, in particular, to bypass uncertainties about the role of the carriers in the transmission.
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Affiliation(s)
| | - Igor V. Erovenko
- Department of Mathematics and Statistics, University of North Carolina at Greensboro, Greensboro, NC 27402, USA
| | - Aaleah Lancaster
- Department of Mathematics and Computer Science, Bennett College, Greensboro, NC 27401, USA
| | - Hyunju Oh
- Division of Mathematics and Computer Science, University of Guam, Mangilao, Guam 96923, USA
| | - Jan Rychtář
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA 23284-2014, USA
| | - Dewey Taylor
- Department of Mathematics and Applied Mathematics, Virginia Commonwealth University, Richmond, VA 23284-2014, USA
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12
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Gibani MM, Voysey M, Jin C, Jones C, Thomaides-Brears H, Jones E, Baker P, Morgan M, Simmons A, Gordon MA, Cerundolo V, Pitzer VE, Angus B, Levine MM, Darton TC, Pollard AJ. The Impact of Vaccination and Prior Exposure on Stool Shedding of Salmonella Typhi and Salmonella Paratyphi in 6 Controlled Human Infection Studies. Clin Infect Dis 2020; 68:1265-1273. [PMID: 30252031 PMCID: PMC6452003 DOI: 10.1093/cid/ciy670] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 08/07/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Shedding of Salmonella Typhi or Paratyphi in the stool or urine leads to contamination of food or water, which is a prerequisite for transmission of enteric fever. Currently, there are limited data on the effect of vaccination or prior exposure on stool shedding. METHODS Six Salmonella Typhi or Paratyphi human challenge studies were conducted between 2011 and 2017. Participants were either unvaccinated or vaccinated with 1 of 4 vaccines: Vi-polysaccharide (Vi-PS), Vi-tetanus-toxoid conjugate vaccine (Vi-TT), live oral Ty21a vaccine, or an experimental vaccine (M01ZH09). Daily stool cultures were collected for 14 days after challenge. RESULTS There were 4934 stool samples collected from 430 volunteers. Participants who received Vi-PS or Vi-TT shed less than unvaccinated participants (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.15-0.77; P = .010 and OR, 0.41; 95% CI, 0.19-0.91, P = .029 for Vi-PS and Vi-TT, respectively). Higher anti-Vi immunoglobulin G titers were associated with less shedding of S. Typhi (P < .0001). A nonsignificant reduction in shedding was associated with Ty21a vaccine (OR, 0.57; 95% CI, 0.27-1.20; P = .140). Individuals previously exposed to S. Typhi shed less than previously unexposed individuals (OR, 0.30; 95% CI, 0.1-0.8; P = .016). Shedding of S. Typhi was more common than S. Paratyphi. CONCLUSIONS Prior vaccination with Vi vaccines, or natural infection, reduces onward transmission of S. Typhi. Field trials of Vi-TT should be designed to detect indirect protection, reflecting the consequence of reduced stool shedding observed in the human challenge model.
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Affiliation(s)
- Malick M Gibani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford
| | - Merryn Voysey
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford.,Nuffield Department of Primary Care Health Sciences, University of Oxford, United Kingdom
| | - Celina Jin
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford
| | | | - Elizabeth Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford
| | - Philip Baker
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford
| | - Marcus Morgan
- Oxford University Hospitals, National Health Service Foundation Trust, United Kingdom
| | - Alison Simmons
- Medical Research Council Human Immunology Unit, Radcliffe Department of Medicine, University of Oxford, United Kingdom.,Translational Gastroenterology Unit, University of Oxford, United Kingdom
| | - Melita A Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre.,Institute for Infection and Global Health, University of Liverpool, United Kingdom
| | - Vincenzo Cerundolo
- Medical Research Council Human Immunology Unit, Radcliffe Department of Medicine, University of Oxford, United Kingdom
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut
| | - Brian Angus
- Oxford University Hospitals, National Health Service Foundation Trust, United Kingdom.,Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Myron M Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford.,National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
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13
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Kaufhold S, Yaesoubi R, Pitzer VE. Predicting the Impact of Typhoid Conjugate Vaccines on Antimicrobial Resistance. Clin Infect Dis 2020; 68:S96-S104. [PMID: 30845324 PMCID: PMC6405272 DOI: 10.1093/cid/ciy1108] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Empiric prescribing of antimicrobials in typhoid-endemic settings has increased selective pressure on the development of antimicrobial-resistant Salmonella enterica serovar Typhi. The introduction of typhoid conjugate vaccines (TCVs) in these settings may relieve this selective pressure, thereby reducing resistant infections and improving health outcomes. Methods A deterministic transmission dynamic model was developed to simulate the impact of TCVs on the number and proportion of antimicrobial-resistant typhoid infections and chronic carriers. One-way sensitivity analyses were performed to ascertain particularly impactful model parameters influencing the proportion of antimicrobial-resistant infections and the proportion of cases averted over 10 years. Results The model simulations suggested that increasing vaccination coverage would decrease the total number of antimicrobial-resistant typhoid infections but not affect the proportion of cases that were antimicrobial resistant. In the base-case scenario with 80% vaccination coverage, 35% of all typhoid infections were antimicrobial resistant, and 44% of the total cases were averted over 10 years by vaccination. Vaccination also decreased both the total number and proportion of chronic carriers of antimicrobial-resistant infections. The prevalence of chronic carriers, recovery rates from infection, and relative fitness of resistant strains were identified as crucially important parameters. Conclusions Model predictions for the proportion of antimicrobial resistant infections and number of cases averted depended strongly on the relative fitness of the resistant strain(s), prevalence of chronic carriers, and rates of recovery without treatment. Further elucidation of these parameter values in real-world typhoid-endemic settings will improve model predictions and assist in targeting future vaccination campaigns and treatment strategies.
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Affiliation(s)
- Samantha Kaufhold
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut
- Present address: Analysis Group, 31 Menlo Park, CA 94025
| | - Reza Yaesoubi
- Department of Health Policy and Management, Yale School of Public Health, Yale University, New Haven, Connecticut
| | - Virginia E Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut
- Correspondence: V. E. Pitzer, Yale School of Public Health, P.O. Box 208034, New Haven, CT 06520-8034 ()
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14
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Raymond M, Gibani MM, Day NPJ, Cheah PY. Typhoidal Salmonella human challenge studies: ethical and practical challenges and considerations for low-resource settings. Trials 2019; 20:704. [PMID: 31852488 PMCID: PMC6921376 DOI: 10.1186/s13063-019-3844-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Typhoidal Salmonella is a major global problem affecting more than 12 million people annually. Controlled human infection models (CHIMs) in high-resource settings have had an important role in accelerating the development of conjugate vaccines against Salmonella Typhi. The typhoidal Salmonella model has an established safety profile in over 2000 volunteers in high-income settings, and trial protocols, with modification, could be readily transferred to new study sites. To date, a typhoidal Salmonella CHIM has not been conducted in a low-resource setting, although it is being considered. Our article describes the challenges posed by a typhoidal Salmonella CHIM in the high-resource setting of Oxford and explores considerations for an endemic setting. Development of CHIMs in endemic settings is scientifically justifiable as it remains unclear whether findings from challenge studies performed in high-resource non-endemic settings can be extrapolated to endemic settings, where the burden of invasive Salmonella is highest. Volunteers are likely to differ across a range of important variables such as previous Salmonella exposure, diet, intestinal microbiota, and genetic profile. CHIMs in endemic settings arguably are ethically justifiable as affected communities are more likely to gain benefit from the study. Local training and research capacity may be bolstered. Safety was of primary importance in the Oxford model. Risk of harm to the individual was mitigated by careful inclusion and exclusion criteria; close monitoring with online diary and daily visits; 24/7 on-call staffing; and access to appropriate hospital facilities with capacity for in-patient admission. Risk of harm to the community was mitigated by exclusion of participants with contact with vulnerable persons; stringent hygiene and sanitation precautions; and demonstration of clearance of Salmonella infection from stool following antibiotic treatment. Safety measures should be more stringent in settings where health systems, transport networks, and sanitation are less robust. We compare the following issues between high- and low-resource settings: scientific justification, risk of harm to the individual and community, benefits to the individual and community, participant understanding, compensation, and regulatory requirements. We conclude that, with careful consideration of country-specific ethical and practical issues, a typhoidal Salmonella CHIM in an endemic setting is possible.
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Affiliation(s)
- Meriel Raymond
- Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital, Old Road, Headington, Oxford, OX3 7LE, UK
| | - Malick M Gibani
- Oxford Vaccine Group Centre for Clinical Vaccinology and Tropical Medicine (CCVTM), Churchill Hospital, Old Road, Headington, Oxford, OX3 7LE, UK
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand. .,Nuffield Department of Clinical Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, OX3 7FZ, UK. .,Nuffield Departmemt of Population Health, The Ethox Centere, University of Oxford, Old Road, Oxford, OX3 7LF, UK.
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15
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Liaquat S, Sarwar Y, Ali A, Haque A, Farooq M, Martinez-Ballesteros I, Laorden L, Garaizar J, Bikandi J. Virulotyping of Salmonella enterica serovar Typhi isolates from Pakistan: Absence of complete SPI-10 in Vi negative isolates. PLoS Negl Trop Dis 2018; 12:e0006839. [PMID: 30500817 PMCID: PMC6267989 DOI: 10.1371/journal.pntd.0006839] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 09/13/2018] [Indexed: 12/30/2022] Open
Abstract
The pathogenesis of Salmonella enterica serovar Typhi (S. Typhi), the cause of typhoid fever in humans, is mainly attributed to the acquisition of horizontally acquired DNA elements. Salmonella pathogenicity islands (SPIs) are indubitably the most important form of horizontally acquired DNA with respect to pathogenesis of this bacterium. The insertion or deletion of any of these transferrable SPIs may have impact on the virulence potential of S. Typhi. In this study, the virulence potential and genetic relatedness of 35 S. Typhi isolates, collected from 2004 to 2013 was determined by identification of SPI and non-SPI virulence factors through a combination of techniques including virulotyping, Whole Genome Sequencing (WGS), and Variable Number of Tandem Repeats (VNTR) profiling. In order to determine the virulence potential of local S. Typhi isolates, 56 virulence related genes were studied by PCR. These genes are located in the core as well as accessory genome (SPIs and plasmid). Major variations among studied virulence determinants were found in case of SPI-7 and SPI-10 associated genes. On the basis of presence of virulence related genes, the studied S. Typhi isolates from Pakistan were clustered into two virulotypes Vi-positive and Vi-negative. Interestingly, SPI-7 and SPI-10 were collectively absent or present in Vi-negative and Vi-positive strains, respectively. Two Vi-negative and 11 Vi-positive S. Typhi strains were also analyzed by whole genome sequencing (WGS) and their results supported the PCR results. Genetic diversity was tested by VNTR-based molecular typing. All 35 isolates were clustered into five groups. Overall, all Vi-negative isolates were placed in a single group (T5) whereas Vi-positive isolates were grouped into four types. Vi-negative and Vi-positive isolates were mutually exclusive. This is the first report on the comparative distribution of SPI and non-SPI related virulence genes in Vi-negative and Vi-positive S. Typhi isolates with an important finding that SPI-10 is absent in all Vi-negative isolates. The distribution of virulence factors in S. Typhi can vary in isolates from different geographical regions and can have significant effect on the disease control. In this study, we have checked the distribution of 56 reported virulence associated factors in 35 local isolates of S. Typhi to identify any variations that can help in designing effective control strategies for typhoid. We have identified four naturally occurring variants which are simultaneously lacking SPI-7 and SPI-10, two adjacently located pathogenicity islands on S. Typhi chromosome. These isolates are not producing Vi capsular antigen hence the Vi based vaccines will not be effective against them. These findings highlight the need to develop typhoid vaccines specifically effective in Pakistan.
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Affiliation(s)
- Sadia Liaquat
- Enteric Pathogen Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
- Departments of Bioinformatics and Biotechnology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Yasra Sarwar
- Enteric Pathogen Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
- * E-mail:
| | - Aamir Ali
- Enteric Pathogen Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Abdul Haque
- Akhuwat Faisalabad Institute For Research In Science And Technology, Faisalabad, Pakistan
| | - Muhammad Farooq
- Enteric Pathogen Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan affiliated with Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Ilargi Martinez-Ballesteros
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country, (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Lorena Laorden
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country, (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Javier Garaizar
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country, (UPV/EHU), Vitoria-Gasteiz, Spain
| | - Joseba Bikandi
- Department of Immunology, Microbiology and Parasitology, University of the Basque Country, (UPV/EHU), Vitoria-Gasteiz, Spain
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16
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Hiyoshi H, Tiffany CR, Bronner DN, Bäumler AJ. Typhoidal Salmonella serovars: ecological opportunity and the evolution of a new pathovar. FEMS Microbiol Rev 2018; 42:527-541. [DOI: 10.1093/femsre/fuy024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/19/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Hirotaka Hiyoshi
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Connor R Tiffany
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Denise N Bronner
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Andreas J Bäumler
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
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17
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Zuckerman JN, Hatz C, Kantele A. Review of current typhoid fever vaccines, cross-protection against paratyphoid fever, and the European guidelines. Expert Rev Vaccines 2018; 16:1029-1043. [PMID: 28856924 DOI: 10.1080/14760584.2017.1374861] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Typhoid and paratyphoid fever remain a global health problem, which - in non-endemic countries - are mainly seen in travelers, particularly in VFRs (visiting friends and relatives), with occasional local outbreaks occurring. A rise in anti-microbial resistance emphasizes the role of preventive measures, especially vaccinations against typhoid and paratyphoid fever for travelers visiting endemic countries. Areas covered: This state-of-the-art review recapitulates the epidemiology and mechanisms of disease of typhoid and paratyphoid fever, depicts the perspective of non-endemic countries and travelers (VFRs), and collectively presents current European recommendations for typhoid fever vaccination. We provide a brief overview of available (and developmental) vaccines in Europe, present current data on cross-protection to S. Paratyphi, and aim to provide a background for typhoid vaccine decision-making in travelers. Expert commentary: European recommendations are not harmonized. Experts must assess vaccination of travelers based on current country-specific recommendations. Travel health practitioners should be aware of the issues surrounding vaccination of travelers and be motivated to increase awareness of typhoid and paratyphoid fever risks.
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Affiliation(s)
- Jane N Zuckerman
- a Department of Infection and Immunity , Royal Free London Travel Health and Immunisation Clinic , London , UK
| | - Christoph Hatz
- b Department of Medicine and Diagnostics , Swiss Tropical and Public Health Institute , Basel , Switzerland.,c Epidemiology, Biostatistics and Prevention Institute , University of Zurich , Zurich , Switzerland
| | - Anu Kantele
- d Department of Clinical Medicine , University of Helsinki , Helsinki , Finland.,e Inflammation Center, Division of Infectious Diseases , Helsinki University Hospital , Helsinki , Finland.,f Unit of Infectious Diseases , Karolinska Institutet , Stockholm , Sweden
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18
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Zhang Y, Brady A, Jones C, Song Y, Darton TC, Jones C, Blohmke CJ, Pollard AJ, Magder LS, Fasano A, Sztein MB, Fraser CM. Compositional and Functional Differences in the Human Gut Microbiome Correlate with Clinical Outcome following Infection with Wild-Type Salmonella enterica Serovar Typhi. mBio 2018; 9:e00686-18. [PMID: 29739901 PMCID: PMC5941076 DOI: 10.1128/mbio.00686-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 01/09/2023] Open
Abstract
Insights into disease susceptibility as well as the efficacy of vaccines against typhoid and other enteric pathogens may be informed by better understanding the relationship between the effector immune response and the gut microbiota. In the present study, we characterized the composition (16S rRNA gene profiling) and function (RNA sequencing [RNA-seq]) of the gut microbiota following immunization and subsequent exposure to wild-type Salmonella enterica serovar Typhi in a human challenge model to further investigate the central hypothesis that clinical outcomes may be linked to the gut microbiota. Metatranscriptome analysis of longitudinal stool samples collected from study subjects revealed two stable patterns of gene expression for the human gut microbiota, dominated by transcripts from either Methanobrevibacter or a diverse representation of genera in the Firmicutes phylum. Immunization with one of two live oral attenuated vaccines against S. Typhi had minimal effects on the composition or function of the gut microbiota. It was observed that subjects harboring the methanogen-dominated transcriptome community at baseline displayed a lower risk of developing symptoms of typhoid following challenge with wild-type S. Typhi. Furthermore, genes encoding antioxidant proteins, metal homeostasis and transport proteins, and heat shock proteins were expressed at a higher level at baseline or after challenge with S. Typhi in subjects who did not develop symptoms of typhoid. These data suggest that functional differences relating to redox potential and ion homeostasis in the gut microbiota may impact clinical outcomes following exposure to wild-type S. Typhi.IMPORTANCES. Typhi is a significant cause of systemic febrile morbidity in settings with poor sanitation and limited access to clean water. It has been demonstrated that the human gut microbiota can influence mucosal immune responses, but there is little information available on the impact of the human gut microbiota on clinical outcomes following exposure to enteric pathogens. Here, we describe differences in the composition and function of the gut microbiota in healthy adult volunteers enrolled in a typhoid vaccine trial and report that these differences are associated with host susceptibility to or protection from typhoid after challenge with wild-type S Typhi. Our observations have important implications in interpreting the efficacy of oral attenuated vaccines against enteric pathogens in diverse populations.
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Affiliation(s)
- Yan Zhang
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Arthur Brady
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Cheron Jones
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Yang Song
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Christoph J Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
- NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Laurence S Magder
- Department of Epidemiology and Preventive Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Alessio Fasano
- Department of Pediatrics, Mucosal Immunology and Biology Research Center, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Marcelo B Sztein
- Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Claire M Fraser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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19
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Kim B, Won G, Lee JH. Construction of an inactivated typhoid vaccine candidate expressing Escherichia coli heat-labile enterotoxin B subunit and evaluation of its immunogenicity in a murine model. J Med Microbiol 2017; 66:1235-1243. [DOI: 10.1099/jmm.0.000543] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Boram Kim
- College of Veterinary Medicine, Chonbuk National University, Iksan campus, Gobong-ro 79 Iksan, 54596, Republic of Korea
| | - Gayeon Won
- College of Veterinary Medicine, Chonbuk National University, Iksan campus, Gobong-ro 79 Iksan, 54596, Republic of Korea
| | - John Hwa Lee
- College of Veterinary Medicine, Chonbuk National University, Iksan campus, Gobong-ro 79 Iksan, 54596, Republic of Korea
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20
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A novel approach for construction of an inactivated typhoid vaccine candidate that effectively augments both humoral and cellular immune responses. Vaccine 2017; 35:3333-3341. [DOI: 10.1016/j.vaccine.2017.04.084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/24/2017] [Accepted: 04/28/2017] [Indexed: 01/11/2023]
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21
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Saad NJ, Bowles CC, Grenfell BT, Basnyat B, Arjyal A, Dongol S, Karkey A, Baker S, Pitzer VE. The impact of migration and antimicrobial resistance on the transmission dynamics of typhoid fever in Kathmandu, Nepal: A mathematical modelling study. PLoS Negl Trop Dis 2017; 11:e0005547. [PMID: 28475605 PMCID: PMC5435358 DOI: 10.1371/journal.pntd.0005547] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 05/17/2017] [Accepted: 04/03/2017] [Indexed: 11/21/2022] Open
Abstract
Background A substantial proportion of the global burden of typhoid fever occurs in South Asia. Kathmandu, Nepal experienced a substantial increase in the number of typhoid fever cases (caused by Salmonella Typhi) between 2000 and 2003, which subsequently declined but to a higher endemic level than in 2000. This epidemic of S. Typhi coincided with an increase in organisms with reduced susceptibility against fluoroquinolones, the emergence of S. Typhi H58, and an increase in the migratory population in Kathmandu. Methods We devised a mathematical model to investigate the potential epidemic drivers of typhoid in Kathmandu and fit this model to weekly data of S. Typhi cases between April 1997 and June 2011 and the age distribution of S. Typhi cases. We used this model to determine if the typhoid epidemic in Kathmandu was driven by heightened migration, the emergence of organisms with reduced susceptibility against fluoroquinolones or a combination of these factors. Results Models allowing for the migration of susceptible individuals into Kathmandu alone or in combination with the emergence of S. Typhi with reduced susceptibility against fluoroquinolones provided a good fit for the data. The emergence of organisms with reduced susceptibility against fluoroquinolones organisms alone, either through an increase in disease duration or increased transmission, did not fully explain the pattern of S. Typhi infections. Conclusions Our analysis is consistent with the hypothesis that the increase in typhoid fever in Kathmandu was associated with the migration of susceptible individuals into the city and aided by the emergence of reduced susceptibility against fluoroquinolones. These data support identifying and targeting migrant populations with typhoid immunization programmes to prevent transmission and disease. Typhoid fever is endemic in Nepal, with Kathmandu coined “the typhoid capital of the world”. We developed a mathematical model to assess the importance of migration and antimicrobial resistance on the transmission of typhoid fever in Kathmandu, Nepal from April 1997 to June 2011. During this period, the burden of typhoid fever increased markedly from January 2000 to December 2003, after which the epidemic declined, but to a higher endemic level than in 2000. Our findings are consistent with the hypothesis that migration of susceptible individuals into Kathmandu played an important role in the epidemic, and may have been further aided by the emergence of typhoid fever with reduced susceptibility against fluoroquinolones. This study showed that identifying and targeting migrant populations with control efforts could be an important avenue to prevent typhoid transmission and disease.
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Affiliation(s)
- Neil J. Saad
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail: (NJS); (VEP)
| | - Cayley C. Bowles
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Bryan T. Grenfell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- Fogarty International Center, Bethesda, Maryland, United States of America
| | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Amit Arjyal
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Abhilasha Karkey
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Stephen Baker
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Virginia E. Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- Fogarty International Center, Bethesda, Maryland, United States of America
- * E-mail: (NJS); (VEP)
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Fresnay S, McArthur MA, Magder LS, Darton TC, Jones C, Waddington CS, Blohmke CJ, Angus B, Levine MM, Pollard AJ, Sztein MB. Importance of Salmonella Typhi-Responsive CD8+ T Cell Immunity in a Human Typhoid Fever Challenge Model. Front Immunol 2017; 8:208. [PMID: 28303138 PMCID: PMC5332428 DOI: 10.3389/fimmu.2017.00208] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 02/15/2017] [Indexed: 01/25/2023] Open
Abstract
Typhoid fever, caused by the human-restricted organism Salmonella enterica serovar Typhi (S. Typhi), constitutes a major global health problem. The development of improved attenuated vaccines is pressing, but delayed by the lack of appropriate preclinical models. Herein, we report that high levels of S. Typhi-responsive CD8+ T cells at baseline significantly correlate with an increased risk of disease in humans challenged with a high dose (~104 CFU) wild-type S. Typhi. Typhoid fever development was associated with higher multifunctional S. Typhi-responsive CD8+ T effector memory cells at baseline. Early decreases of these cells in circulation following challenge were observed in both S. Typhi-responsive integrin α4β7− and integrin α4β7+ CD8+ T effector memory (TEM) cells, suggesting their potential to home to both mucosal and extra-intestinal sites. Participants with higher baseline levels of S. Typhi-responsive CD8+ T memory cells had a higher risk of acquiring disease, but among those who acquired disease, those with a higher baseline responses took longer to develop disease. In contrast, protection against disease was associated with low or absent S. Typhi-responsive T cells at baseline and no changes in circulation following challenge. These data highlight the importance of pre-existing S. Typhi-responsive immunity in predicting clinical outcome following infection with wild-type S. Typhi and provide novel insights into the complex mechanisms involved in protective immunity to natural infection in a stringent human model with a high challenge dose. They also contribute important information on the immunological responses to be assessed in the appraisal and selection of new generation typhoid vaccines.
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Affiliation(s)
- Stephanie Fresnay
- Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Monica A McArthur
- Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Laurence S Magder
- Department of Epidemiology and Public Health, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre , Oxford , UK
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre , Oxford , UK
| | - Claire S Waddington
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre , Oxford , UK
| | - Christoph J Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre , Oxford , UK
| | - Brian Angus
- Nuffield Department of Medicine, University of Oxford , Oxford , UK
| | - Myron M Levine
- Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, NIHR Oxford Biomedical Research Centre , Oxford , UK
| | - Marcelo B Sztein
- Center for Vaccine Development, University of Maryland School of Medicine , Baltimore, MD , USA
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23
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Hu X, Chen Z, Xiong K, Wang J, Rao X, Cong Y. Vi capsular polysaccharide: Synthesis, virulence, and application. Crit Rev Microbiol 2016; 43:440-452. [PMID: 27869515 DOI: 10.1080/1040841x.2016.1249335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Vi capsular polysaccharide, a linear homopolymer of α-1,4-linked N-acetylgalactosaminuronate, is characteristically produced by Salmonella enterica serovar Typhi. The Vi capsule covers the surface of the producing bacteria and serves as an virulence factor via inhibition of complement-mediated killing and promoting resistance against phagocytosis. Furthermore, Vi also represents a predominant protective antigen and plays a key role in the development of vaccines against typhoid fever. Herein, we reviewed the latest advances associated with the Vi polysaccharide, from its synthesis and transport within bacterial cells, mechanisms involved in virulence, immunological characteristics, and applications in vaccine, as well as its purification and detection methods.
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Affiliation(s)
- Xiaomei Hu
- a Department of Microbiology , Third Military Medical University , Chongqing , China
| | - Zhijin Chen
- a Department of Microbiology , Third Military Medical University , Chongqing , China
| | - Kun Xiong
- a Department of Microbiology , Third Military Medical University , Chongqing , China
| | - Jing Wang
- a Department of Microbiology , Third Military Medical University , Chongqing , China
| | - Xiancai Rao
- a Department of Microbiology , Third Military Medical University , Chongqing , China
| | - Yanguang Cong
- a Department of Microbiology , Third Military Medical University , Chongqing , China
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Abstract
Animals that cannot sense endotoxin may die if they are infected by Gram-negative bacteria. Animals that sense endotoxin and respond too vigorously may also die, victims of their own inflammatory reactions. The outcome of Gram-negative bacterial infection is thus determined not only by an individual's ability to sense endotoxin and respond to its presence, but also by numerous phenomena that inactivate endotoxin and/or prevent harmful reactions to it. Endotoxin sensing requires the MD-2/TLR4 recognition complex and occurs principally in local tissues and the liver. This review highlights the known detoxification mechanisms, which include: (i) proteins that facilitate LPS sequestration by plasma lipoproteins, prevent interactions between the bioactive lipid A moiety and MD-2/TLR4, or promote cellular uptake via non-signaling pathway(s); (ii) enzymes that deacylate or dephosphorylate lipid A; (iii) mechanisms that remove LPS and Gram-negative bacteria from the bloodstream; and (iv) neuroendocrine adaptations that modulate LPS-induced mediator production or neutralize pro-inflammatory molecules in the circulation. In general, the mechanisms for sensing and detoxifying endotoxin seem to be compartmentalized (local versus systemic), dynamic, and variable between individuals. They may have evolved to confine infection and inflammation to extravascular sites of infection while preventing harmful systemic reactions. Integration of endotoxin sensing and detoxification is essential for successful host defense.
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Affiliation(s)
- Robert S. Munford
- Molecular Host Defense Laboratory, Departments of Internal Medicine and Microbiology, University of Texas Southwestern Medical School, Dallas, Texas, USA,
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25
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Darton TC, Jones C, Blohmke CJ, Waddington CS, Zhou L, Peters A, Haworth K, Sie R, Green CA, Jeppesen CA, Moore M, Thompson BAV, John T, Kingsley RA, Yu LM, Voysey M, Hindle Z, Lockhart S, Sztein MB, Dougan G, Angus B, Levine MM, Pollard AJ. Using a Human Challenge Model of Infection to Measure Vaccine Efficacy: A Randomised, Controlled Trial Comparing the Typhoid Vaccines M01ZH09 with Placebo and Ty21a. PLoS Negl Trop Dis 2016; 10:e0004926. [PMID: 27533046 PMCID: PMC4988630 DOI: 10.1371/journal.pntd.0004926] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/25/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Typhoid persists as a major cause of global morbidity. While several licensed vaccines to prevent typhoid are available, they are of only moderate efficacy and unsuitable for use in children less than two years of age. Development of new efficacious vaccines is complicated by the human host-restriction of Salmonella enterica serovar Typhi (S. Typhi) and lack of clear correlates of protection. In this study, we aimed to evaluate the protective efficacy of a single dose of the oral vaccine candidate, M01ZH09, in susceptible volunteers by direct typhoid challenge. METHODS AND FINDINGS We performed a randomised, double-blind, placebo-controlled trial in healthy adult participants at a single centre in Oxford (UK). Participants were allocated to receive one dose of double-blinded M01ZH09 or placebo or 3-doses of open-label Ty21a. Twenty-eight days after vaccination, participants were challenged with 104CFU S. Typhi Quailes strain. The efficacy of M01ZH09 compared with placebo (primary outcome) was assessed as the percentage of participants reaching pre-defined endpoints constituting typhoid diagnosis (fever and/or bacteraemia) during the 14 days after challenge. Ninety-nine participants were randomised to receive M01ZH09 (n = 33), placebo (n = 33) or 3-doses of Ty21a (n = 33). After challenge, typhoid was diagnosed in 18/31 (58.1% [95% CI 39.1 to 75.5]) M01ZH09, 20/30 (66.7% [47.2 to 87.2]) placebo, and 13/30 (43.3% [25.5 to 62.6]) Ty21a vaccine recipients. Vaccine efficacy (VE) for one dose of M01ZH09 was 13% [95% CI -29 to 41] and 35% [-5 to 60] for 3-doses of Ty21a. Retrospective multivariable analyses demonstrated that pre-existing anti-Vi antibody significantly reduced susceptibility to infection after challenge; a 1 log increase in anti-Vi IgG resulting in a 71% decrease in the hazard ratio of typhoid diagnosis ([95% CI 30 to 88%], p = 0.006) during the 14 day challenge period. Limitations to the study included the requirement to limit the challenge period prior to treatment to 2 weeks, the intensity of the study procedures and the high challenge dose used resulting in a stringent model. CONCLUSIONS Despite successfully demonstrating the use of a human challenge study to directly evaluate vaccine efficacy, a single-dose M01ZH09 failed to demonstrate significant protection after challenge with virulent Salmonella Typhi in this model. Anti-Vi antibody detected prior to vaccination played a major role in outcome after challenge. TRIAL REGISTRATION ClinicalTrials.gov (NCT01405521) and EudraCT (number 2011-000381-35).
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Affiliation(s)
- Thomas C. Darton
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Christoph J. Blohmke
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Claire S. Waddington
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Liqing Zhou
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Anna Peters
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Kathryn Haworth
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Rebecca Sie
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Christopher A. Green
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Catherine A. Jeppesen
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Maria Moore
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Ben A. V. Thompson
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Tessa John
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
| | - Robert A. Kingsley
- Microbial Pathogenesis Group, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Ly-Mee Yu
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Merryn Voysey
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Zoe Hindle
- Emergent Product Development UK Ltd, Emergent BioSolutions, Wokingham, United Kingdom
| | - Stephen Lockhart
- Emergent Product Development UK Ltd, Emergent BioSolutions, Wokingham, United Kingdom
| | - Marcelo B. Sztein
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Gordon Dougan
- Microbial Pathogenesis Group, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Brian Angus
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Myron M. Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, and the NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, United Kingdom
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Abstract
Typhoid fever is unique to humans. It remains a significant health problem in many developing countries, and poses a risk to travelers who visit such endemic regions. The proportion of cases acquired in foreign countries has continued to rise, reaching 70% in 1984. The risk of typhoid fever should not be underestimated as a travel-related illness.The incidence of typhoid fever in the united states has decreased from one case per 100,00 population in 1955 to about 0.2 cases per 100,000 in 1966, and has since remained the same. However, international travelers account for more than two-thirds of the reported cases. The percentage of imported cases increased from 33% during 1967 through 1972, to 70% during 1983 through 1984. The majority of the imported cases were from mexico (39%) and india (15%). During the decade 1975 through 1984, 43% of travel-associated cases were non-U.S. citizens. the risk of acquiring typhoid varied from country to country and was the highest for travelers to india and pakistan, with over 400 cases per million, compared with mexico, with 34 per million, and europe, with 0.6 cases per million travelers.
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27
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Blohmke CJ, Darton TC, Jones C, Suarez NM, Waddington CS, Angus B, Zhou L, Hill J, Clare S, Kane L, Mukhopadhyay S, Schreiber F, Duque-Correa MA, Wright JC, Roumeliotis TI, Yu L, Choudhary JS, Mejias A, Ramilo O, Shanyinde M, Sztein MB, Kingsley RA, Lockhart S, Levine MM, Lynn DJ, Dougan G, Pollard AJ. Interferon-driven alterations of the host's amino acid metabolism in the pathogenesis of typhoid fever. J Exp Med 2016; 213:1061-77. [PMID: 27217537 PMCID: PMC4886356 DOI: 10.1084/jem.20151025] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 04/08/2016] [Indexed: 12/30/2022] Open
Abstract
Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host-pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever.
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Affiliation(s)
- Christoph J. Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
| | - Thomas C. Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
| | - Nicolas M. Suarez
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Claire S. Waddington
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
| | - Brian Angus
- Nuffield Department of Medicine, University of Oxford, OX1 2JD, England, UK
| | - Liqing Zhou
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
| | - Jennifer Hill
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Simon Clare
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Leanne Kane
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Subhankar Mukhopadhyay
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Fernanda Schreiber
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Maria A. Duque-Correa
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - James C. Wright
- Proteomic Mass Spectrometry, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | | | - Lu Yu
- Proteomic Mass Spectrometry, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Jyoti S. Choudhary
- Proteomic Mass Spectrometry, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Asuncion Mejias
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Octavio Ramilo
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, The Ohio State University College of Medicine, Columbus, OH 43210
| | - Milensu Shanyinde
- Nuffield Department of Primary Care Health Sciences, University of Oxford, OX1 2JD, England, UK
| | - Marcelo B. Sztein
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Robert A. Kingsley
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Stephen Lockhart
- Emergent Product Development UK, Emergent BioSolutions, Wokingham RG41 5TU, England, UK
| | - Myron M. Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201
| | - David J. Lynn
- EMBL Australia Group, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia,School of Medicine, Flinders University, Bedford Park, SA 5042, Australia
| | - Gordon Dougan
- Microbial Pathogenesis Group, The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, England, UK
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, England, UK
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Hitchcock JR, Cook CN, Bobat S, Ross EA, Flores-Langarica A, Lowe KL, Khan M, Dominguez-Medina CC, Lax S, Carvalho-Gaspar M, Hubscher S, Rainger GE, Cobbold M, Buckley CD, Mitchell TJ, Mitchell A, Jones ND, Van Rooijen N, Kirchhofer D, Henderson IR, Adams DH, Watson SP, Cunningham AF. Inflammation drives thrombosis after Salmonella infection via CLEC-2 on platelets. J Clin Invest 2015; 125:4429-46. [PMID: 26571395 DOI: 10.1172/jci79070] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 10/08/2015] [Indexed: 01/13/2023] Open
Abstract
Thrombosis is a common, life-threatening consequence of systemic infection; however, the underlying mechanisms that drive the formation of infection-associated thrombi are poorly understood. Here, using a mouse model of systemic Salmonella Typhimurium infection, we determined that inflammation in tissues triggers thrombosis within vessels via ligation of C-type lectin-like receptor-2 (CLEC-2) on platelets by podoplanin exposed to the vasculature following breaching of the vessel wall. During infection, mice developed thrombi that persisted for weeks within the liver. Bacteria triggered but did not maintain this process, as thrombosis peaked at times when bacteremia was absent and bacteria in tissues were reduced by more than 90% from their peak levels. Thrombus development was triggered by an innate, TLR4-dependent inflammatory cascade that was independent of classical glycoprotein VI-mediated (GPVI-mediated) platelet activation. After infection, IFN-γ release enhanced the number of podoplanin-expressing monocytes and Kupffer cells in the hepatic parenchyma and perivascular sites and absence of TLR4, IFN-γ, or depletion of monocytic-lineage cells or CLEC-2 on platelets markedly inhibited the process. Together, our data indicate that infection-driven thrombosis follows local inflammation and upregulation of podoplanin and platelet activation. The identification of this pathway offers potential therapeutic opportunities to control the devastating consequences of infection-driven thrombosis without increasing the risk of bleeding.
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29
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Gibani MM, Jin C, Darton TC, Pollard AJ. Control of Invasive Salmonella Disease in Africa: Is There a Role for Human Challenge Models? Clin Infect Dis 2015; 61 Suppl 4:S266-71. [PMID: 26449941 PMCID: PMC4596929 DOI: 10.1093/cid/civ673] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Invasive Salmonella disease in Africa is a major public health concern. With evidence of the transcontinental spread of the Salmonella Typhi H58 haplotype, improved estimates of the burden of infection and understanding of the complex interplay of factors affecting disease transmission are needed to assist with efforts aimed at disease control. In addition to Salmonella Typhi, invasive nontyphoidal Salmonella are increasingly recognized as an important cause of febrile illness and mortality in sub-Saharan Africa. Human experimental oral challenge studies with Salmonella can be used as a model to offer unique insights into host-pathogen interactions as well as a platform to efficiently test new diagnostic and vaccine candidates. In this article, we review the background and use of human challenge studies to date and discuss how findings from these studies may lead to progress in the control of invasive Salmonella disease in Africa.
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Affiliation(s)
- Malick M Gibani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
| | - Celina Jin
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the National Institute for Health Research Oxford Biomedical Research Centre, United Kingdom
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30
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Pitzer VE, Feasey NA, Msefula C, Mallewa J, Kennedy N, Dube Q, Denis B, Gordon MA, Heyderman RS. Mathematical Modeling to Assess the Drivers of the Recent Emergence of Typhoid Fever in Blantyre, Malawi. Clin Infect Dis 2015; 61 Suppl 4:S251-8. [PMID: 26449939 PMCID: PMC4596932 DOI: 10.1093/cid/civ710] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Multiyear epidemics of Salmonella enterica serovar Typhi have been reported from countries across eastern and southern Africa in recent years. In Blantyre, Malawi, a dramatic increase in typhoid fever cases has recently occurred, and may be linked to the emergence of the H58 haplotype. Strains belonging to the H58 haplotype often exhibit multidrug resistance and may have a fitness advantage relative to other Salmonella Typhi strains. METHODS To explore hypotheses for the increased number of typhoid fever cases in Blantyre, we fit a mathematical model to culture-confirmed cases of Salmonella enterica infections at Queen Elizabeth Central Hospital, Blantyre. We explored 4 hypotheses: (1) an increase in the basic reproductive number (R0) in response to increasing population density; (2) a decrease in the incidence of cross-immunizing infection with Salmonella Enteritidis; (3) an increase in the duration of infectiousness due to failure to respond to first-line antibiotics; and (4) an increase in the transmission rate following the emergence of the H58 haplotype. RESULTS Increasing population density or decreasing cross-immunity could not fully explain the observed pattern of typhoid emergence in Blantyre, whereas models allowing for an increase in the duration of infectiousness and/or the transmission rate of typhoid following the emergence of the H58 haplotype provided a good fit to the data. CONCLUSIONS Our results suggest that an increase in the transmissibility of typhoid due to the emergence of drug resistance associated with the H58 haplotype may help to explain recent outbreaks of typhoid in Malawi and similar settings in Africa.
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Affiliation(s)
- Virginia E. Pitzer
- Departmentof Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut
| | - Nicholas A. Feasey
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
- Liverpool School of Tropical Medicine, United Kingdom
| | - Chisomo Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
- Department of Microbiology
| | | | - Neil Kennedy
- Department of Paediatrics and Child Health, University of Malawi College of Medicine, Blantyre
| | - Queen Dube
- Department of Paediatrics and Child Health, University of Malawi College of Medicine, Blantyre
| | - Brigitte Denis
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
| | - Melita A. Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
- Institute of Infection and Global Health, University of Liverpool
| | - Robert S. Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre
- Division of Infection and Immunity, University College London, United Kingdom
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Fennelly KP, Jones-López EC. Quantity and Quality of Inhaled Dose Predicts Immunopathology in Tuberculosis. Front Immunol 2015; 6:313. [PMID: 26175730 PMCID: PMC4484340 DOI: 10.3389/fimmu.2015.00313] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 06/02/2015] [Indexed: 12/28/2022] Open
Abstract
Experimental animal models of tuberculosis (TB) have convincingly demonstrated that inhaled dose predicts immunopathology and survival. In contrast, the importance of inhaled dose has generally not been appreciated in TB epidemiology, clinical science, or the practice of TB control. Infectiousness of TB patients has traditionally been assessed using microscopy for acid-fast bacilli in the sputum, which should be considered only a risk factor. We have recently demonstrated that cough aerosol cultures from index cases with pulmonary TB are the best predictors of new infection among household contacts. We suggest that cough aerosols of M. tuberculosis are the best surrogates of inhaled dose, and we hypothesize that the quantity of cough aerosols is associated with TB infection versus disease. Although several factors affect the quality of infectious aerosols, we propose that the particle size distribution of cough aerosols is an important predictor of primary upper airway disease and cervical lymphadenitis and of immune responses in exposed hosts. We hypothesize that large droplet aerosols (>5 μ) containing M. tuberculosis deposit in the upper airway and can induce immune responses without establishing infection. We suggest that this may partially explain the large proportion of humans who never develop TB disease in spite of having immunological evidence of M. tuberculosis infection (e.g., positive tuberculin skin test or interferon gamma release assay). If these hypotheses are proven true, they would alter the current paradigm of latent TB infection and reactivation, further demonstrating the need for better biomarkers or methods of assessing TB infection and the risk of developing disease.
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Affiliation(s)
- Kevin P Fennelly
- Department of Medicine, Emerging Pathogens Institute, University of Florida , Gainesville, FL , USA
| | - Edward C Jones-López
- Section of Infectious Diseases, Boston Medical Center, Boston University School of Medicine , Boston, MA , USA
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Kantele A. Should close contacts of returning travellers with typhoid fever be protected by vaccination? Vaccine 2015; 33:1419-21. [PMID: 25678244 DOI: 10.1016/j.vaccine.2015.01.052] [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: 06/21/2014] [Revised: 01/13/2015] [Accepted: 01/20/2015] [Indexed: 10/24/2022]
Abstract
Increasing international travel to areas endemic for typhoid fever correlates with increased risk for travellers to contract the disease. At home, the acutely ill/convalescent patients may pose some risk to their close contacts. In Finland an unofficial guideline suggests vaccination for close contacts of patients with acute typhoid fever; in other developed countries, routine typhoid vaccinations are only recommended to contacts of chronic carriers. This paper discusses the possibilities and limitations of prophylactic/post-exposure typhoid vaccination for contacts of patients with acute disease.
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Affiliation(s)
- A Kantele
- Inflammation Center, Clinic of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Finland; Department of Clinical Medicine, University of Helsinki, Helsinki, Finland.
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Jones C, Darton TC, Pollard AJ. Why the development of effective typhoid control measures requires the use of human challenge studies. Front Microbiol 2014; 5:707. [PMID: 25566221 PMCID: PMC4267421 DOI: 10.3389/fmicb.2014.00707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/27/2014] [Indexed: 01/21/2023] Open
Affiliation(s)
- Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford Oxford, UK
| | - Thomas C Darton
- Oxford Vaccine Group, Department of Paediatrics, National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford Oxford, UK
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford Oxford, UK
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Sztein MB, Salerno-Goncalves R, McArthur MA. Complex adaptive immunity to enteric fevers in humans: lessons learned and the path forward. Front Immunol 2014; 5:516. [PMID: 25386175 PMCID: PMC4209864 DOI: 10.3389/fimmu.2014.00516] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/03/2014] [Indexed: 01/26/2023] Open
Abstract
Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever, and S. Paratyphi A and B, causative agents of paratyphoid fever, are major public health threats throughout the world. Although two licensed typhoid vaccines are currently available, they are only moderately protective and immunogenic necessitating the development of novel vaccines. A major obstacle in the development of improved typhoid, as well as paratyphoid vaccines is the lack of known immunological correlates of protection in humans. Considerable progress has been made in recent years in understanding the complex adaptive host responses against S. Typhi. Although the induction of S. Typhi-specific antibodies (including their functional properties) and memory B cells, as well as their cross-reactivity with S. Paratyphi A and S. Paratyphi B has been shown, the role of humoral immunity in protection remains undefined. Cell mediated immunity (CMI) is likely to play a dominant role in protection against enteric fever pathogens. Detailed measurements of CMI performed in volunteers immunized with attenuated strains of S. Typhi have shown, among others, the induction of lymphoproliferation, multifunctional type 1 cytokine production, and CD8(+) cytotoxic T-cell responses. In addition to systemic responses, the local microenvironment of the gut is likely to be of paramount importance in protection from these infections. In this review, we will critically assess current knowledge regarding the role of CMI and humoral immunity following natural S. Typhi and S. Paratyphi infections, experimental challenge, and immunization in humans. We will also address recent advances regarding cross-talk between the host's gut microbiota and immunization with attenuated S. Typhi, mechanisms of systemic immune responses, and the homing potential of S. Typhi-specific B- and T-cells to the gut and other tissues.
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Affiliation(s)
- Marcelo B Sztein
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
| | - Rosangela Salerno-Goncalves
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
| | - Monica A McArthur
- Department of Pediatrics, Center for Vaccine Development (CVD), University of Maryland School of Medicine , Baltimore, MD , USA
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Dougan G, Baker S. Salmonella entericaSerovar Typhi and the Pathogenesis of Typhoid Fever. Annu Rev Microbiol 2014; 68:317-36. [DOI: 10.1146/annurev-micro-091313-103739] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom;
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Program, Oxford University, Clinical Research Unit, Ho Chi Minh City, Vietnam;
- Centre for Tropical Medicine, Oxford University, Oxford OX3 7FZ, United Kingdom
- The London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
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Advancing the management and control of typhoid fever: A review of the historical role of human challenge studies. J Infect 2014; 68:405-18. [DOI: 10.1016/j.jinf.2014.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 01/31/2023]
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Bhuiyan S, Sayeed A, Khanam F, Leung DT, Rahman Bhuiyan T, Sheikh A, Salma U, LaRocque RC, Harris JB, Pacek M, Calderwood SB, LaBaer J, Ryan ET, Qadri F, Charles RC. Cellular and cytokine responses to Salmonella enterica serotype Typhi proteins in patients with typhoid fever in Bangladesh. Am J Trop Med Hyg 2014; 90:1024-1030. [PMID: 24615129 PMCID: PMC4047724 DOI: 10.4269/ajtmh.13-0261] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We assessed interferon-gamma (IFN-γ) responses via enzyme-linked immunosorbent spot (ELISPOT) to a number of S. Typhi antigens in samples from humans with S. Typhi bacteremia and typhoid fever in Bangladesh. Compared with responses in healthy endemic zone controls, there were significantly increased IFN-γ responses at the time of clinical presentation (acute phase) and at convalescence 14–28 days later. The majority (80–90%) of IFN-γ expressing T cells were CD4+. We observed a significant increase in interleukin-17 (IL-17) positive CD4 + T cells at convalescent versus acute stage of infection using an intracellular cytokine staining assay. We also found that stimulated peripheral blood mononuclear cells (PBMCs) produced significantly increased levels of a number of cytokines at the convalescent versus acute phase of infection, including IFN-γ, MIP-1β, sCD40L, TNF-β, IL-13, and IL-9. These results suggest that S. Typhi antigens induce a predominantly Th1 response, but that elevations in other cytokines may be modulatory.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Richelle C. Charles
- * Address correspondence Richelle C. Charles, Division of Infectious Diseases, Massachusetts General Hospital, Jackson 504, 55 Fruit St., Boston, MA 02114. E-mail:
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Waddington CS, Darton TC, Jones C, Haworth K, Peters A, John T, Thompson BAV, Kerridge SA, Kingsley RA, Zhou L, Holt KE, Yu LM, Lockhart S, Farrar JJ, Sztein MB, Dougan G, Angus B, Levine MM, Pollard AJ. An outpatient, ambulant-design, controlled human infection model using escalating doses of Salmonella Typhi challenge delivered in sodium bicarbonate solution. Clin Infect Dis 2014; 58:1230-40. [PMID: 24519873 PMCID: PMC3982839 DOI: 10.1093/cid/ciu078] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Oral delivery of escalating-dose Salmonella Typhi (Quailes strain) using sodium bicarbonate buffer solution in an outpatient, ambulant-design human infection study demonstrates safety, requires a lower challenge inoculum than that used in historical studies, and offers a unique insight into host–pathogen interactions. Background. Typhoid fever is a major global health problem, the control of which is hindered by lack of a suitable animal model in which to study Salmonella Typhi infection. Until 1974, a human challenge model advanced understanding of typhoid and was used in vaccine development. We set out to establish a new human challenge model and ascertain the S. Typhi (Quailes strain) inoculum required for an attack rate of 60%–75% in typhoid-naive volunteers when ingested with sodium bicarbonate solution. Methods. Groups of healthy consenting adults ingested escalating dose levels of S. Typhi and were closely monitored in an outpatient setting for 2 weeks. Antibiotic treatment was initiated if typhoid diagnosis occurred (temperature ≥38°C sustained ≥12 hours or bacteremia) or at day 14 in those remaining untreated. Results. Two dose levels (103 or 104 colony-forming units) were required to achieve the primary objective, resulting in attack rates of 55% (11/20) or 65% (13/20), respectively. Challenge was well tolerated; 4 of 40 participants fulfilled prespecified criteria for severe infection. Most diagnoses (87.5%) were confirmed by blood culture, and asymptomatic bacteremia and stool shedding of S. Typhi was also observed. Participants who developed typhoid infection demonstrated serological responses to flagellin and lipopolysaccharide antigens by day 14; however, no anti-Vi antibody responses were detected. Conclusions. Human challenge with a small inoculum of virulent S. Typhi administered in bicarbonate solution can be performed safely using an ambulant-model design to advance understanding of host–pathogen interactions and immunity. This model should expedite development of diagnostics, vaccines, and therapeutics for typhoid control.
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Pitzer VE, Bowles CC, Baker S, Kang G, Balaji V, Farrar JJ, Grenfell BT. Predicting the impact of vaccination on the transmission dynamics of typhoid in South Asia: a mathematical modeling study. PLoS Negl Trop Dis 2014; 8:e2642. [PMID: 24416466 PMCID: PMC3886927 DOI: 10.1371/journal.pntd.0002642] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Accepted: 11/27/2013] [Indexed: 12/02/2022] Open
Abstract
Background Modeling of the transmission dynamics of typhoid allows for an evaluation of the potential direct and indirect effects of vaccination; however, relevant typhoid models rooted in data have rarely been deployed. Methodology/Principal Findings We developed a parsimonious age-structured model describing the natural history and immunity to typhoid infection. The model was fit to data on culture-confirmed cases of typhoid fever presenting to Christian Medical College hospital in Vellore, India from 2000–2012. The model was then used to evaluate the potential impact of school-based vaccination strategies using live oral, Vi-polysaccharide, and Vi-conjugate vaccines. The model was able to reproduce the incidence and age distribution of typhoid cases in Vellore. The basic reproductive number (R0) of typhoid was estimated to be 2.8 in this setting. Vaccination was predicted to confer substantial indirect protection leading to a decrease in the incidence of typhoid in the short term, but (intuitively) typhoid incidence was predicted to rebound 5–15 years following a one-time campaign. Conclusions/Significance We found that model predictions for the overall and indirect effects of vaccination depend strongly on the role of chronic carriers in transmission. Carrier transmissibility was tentatively estimated to be low, consistent with recent studies, but was identified as a pivotal area for future research. It is unlikely that typhoid can be eliminated from endemic settings through vaccination alone. We developed a mathematical model for the transmission dynamics of typhoid in order to evaluate the potential direct and indirect (i.e. herd immunity) effects of vaccination. The model was fit to data from Vellore, India and validated against the results of cluster randomized vaccine trials. We evaluated a variety of school-based vaccination strategies and found that typhoid vaccination is expected to lead to short-term indirect protection and a decrease in typhoid incidence, but vaccination alone is unlikely to lead to elimination. The level of indirect protection was found to depend on assumptions about the role of chronic carriers, identifying an important area for future research.
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Affiliation(s)
- Virginia E. Pitzer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Cayley C. Bowles
- Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, United Kingdom
- The London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gagandeep Kang
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Veeraraghavan Balaji
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Jeremy J. Farrar
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, Oxford University, Oxford, United Kingdom
| | - Bryan T. Grenfell
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
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Saul A, Smith T, Maire N. Stochastic simulation of endemic Salmonella enterica serovar Typhi: the importance of long lasting immunity and the carrier state. PLoS One 2013; 8:e74097. [PMID: 24040177 PMCID: PMC3769365 DOI: 10.1371/journal.pone.0074097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 07/28/2013] [Indexed: 11/29/2022] Open
Abstract
Background Typhoid fever caused by Salmonella enterica serovar Typhi (S. Typhi) remains a serious burden of disease, especially in developing countries of Asia and Africa. It is estimated that it causes 200,000 deaths per year, mainly in children. S. Typhi is an obligate pathogen of humans and although it has a relatively complex life cycle with a long lived carrier state, the absence of non-human hosts suggests that well targeted control methods should have a major impact on disease. Newer control methods including new generations of vaccines offer hope but their implementation would benefit from quantitative models to guide the most cost effective strategies. This paper presents a quantitative model of Typhoid disease, immunity and transmission as a first step in that process. Methodology/Principal Findings A stochastic agent-based model has been developed that incorporates known features of the biology of typhoid including probability of infection, the consequences of infection, treatment options, acquisition and loss of immunity as a result of infection and vaccination, the development of the carrier state and the impact of environmental or behavioral factors on transmission. The model has been parameterized with values derived where possible from the literature and where this was not possible, feasible parameters space has been determined by sensitivity analyses, fitting the simulations to age distribution of field data. The model is able to adequately predict the age distribution of typhoid in two settings. Conclusions/Significance The modeling highlights the importance of variations in the exposure/resistance of infants and young children to infection in different settings, especially as this impacts on design of control programs; it predicts that naturally induced clinical and sterile immunity to typhoid is long lived and highlights the importance of the carrier state especially in areas of low transmission.
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Affiliation(s)
- Allan Saul
- Novartis Vaccines Institute for Global Health, Siena, Italy
- * E-mail:
| | - Tom Smith
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nicolas Maire
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Molecular characterization of the viaB locus encoding the biosynthetic machinery for Vi capsule formation in Salmonella Typhi. PLoS One 2012; 7:e45609. [PMID: 23029132 PMCID: PMC3448643 DOI: 10.1371/journal.pone.0045609] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/23/2012] [Indexed: 01/30/2023] Open
Abstract
The Vi capsular polysaccharide (CPS) of Salmonella enterica serovar Typhi, the cause of human typhoid, is important for infectivity and virulence. The Vi biosynthetic machinery is encoded within the viaB locus composed of 10 genes involved in regulation of expression (tviA), polymer synthesis (tviB-tviE), and cell surface localization of the CPS (vexA-vexE). We cloned the viaB locus from S. Typhi and transposon insertion mutants of individual viaB genes were characterized in Escherichia coli DH5α. Phenotype analysis of viaB mutants revealed that tviB, tviC, tviD and tviE are involved in Vi polymer synthesis. Furthermore, expression of tviB-tviE in E. coli DH5α directed the synthesis of cytoplasmic Vi antigen. Mutants of the ABC transporter genes vexBC and the polysaccharide copolymerase gene vexD accumulated the Vi polymer within the cytoplasm and productivity in these mutants was greatly reduced. In contrast, de novo synthesis of Vi polymer in the export deficient vexA mutant was comparable to wild-type cells, with drastic effects on cell stability. VexE mutant cells exported the Vi, but the CPS was not retained at the cell surface. The secreted polymer of a vexE mutant had different physical characteristics compared to the wild-type Vi.
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Abstract
The host restricts dissemination of invasive enteric pathogens, such as non-typhoidal Salmonella serovars, by mounting acute inflammatory responses characterized by the recruitment of neutrophils. However, some enteric pathogens, such as Salmonella enterica serovar Typhi (S. typhi), can bypass these defenses and cause an invasive bloodstream infection known as typhoid fever. Recent studies on virulence mechanisms of S. typhi suggest that tight regulation of virulence gene expression during the transition from the intestinal lumen into the intestinal mucosa enables this pathogen to evade detection by the innate immune system, thereby penetrating defenses that prevent bacterial dissemination. This example illustrates how the outcome of host pathogen interaction at the intestinal mucosal interface can alter the clinical presentation and dictate the disease outcome.
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Affiliation(s)
- Tamding Wangdi
- Department of Medical Microbiology and Immunology; School of Medicine; University of California at Davis; Davis, CA USA
| | - Sebastian E. Winter
- Department of Medical Microbiology and Immunology; School of Medicine; University of California at Davis; Davis, CA USA
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology; School of Medicine; University of California at Davis; Davis, CA USA
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Raza A, Sarwar Y, Ali A, Jamil A, Haque A, Haque A. Effect of biofilm formation on the excretion of Salmonella enterica serovar Typhi in feces. Int J Infect Dis 2011; 15:e747-52. [PMID: 21816646 DOI: 10.1016/j.ijid.2011.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 03/25/2011] [Accepted: 06/06/2011] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES We hypothesized that Salmonella enterica serovar Typhi (S. Typhi) with higher biofilm and capsule production capability are more able to survive continuously in typhoid patients/carriers, with subsequent prolonged shedding in feces. METHODS Bacterial cell release from biofilm (produced in vitro and confirmed by specific staining and electron microscopy) and comparative cytotoxicity were studied on Caco2 cells. Functionality of the biofilm diffusion barrier was tested against ciprofloxacin. Biofilm production was graded and semi-quantified as -, +, ++, +++, and ++++. RESULTS Out of 30 isolates, 23 produced biofilm. The average post-treatment detection of S. Typhi in blood was 7-13 days and in stool was 13-32 days. A fall in cell count from 10⁴ to approximately 10¹ over the course of 3 days as compared to total elimination of planktonic cells in 16 h after ciprofloxacin application substantiated the protective role of biofilm. Lactic dehydrogenase release ranged from 38% in non-biofilm producers to 97% in the highest biofilm producers, indicating increased pathogenic behavior. CONCLUSIONS The period of S. Typhi clearance from typhoid patients after recovery was found to be directly related to biofilm production capability.
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Affiliation(s)
- Abida Raza
- Molecular Diagnostics and Research Laboratory, Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad, Pakistan
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The Vi conjugate typhoid vaccine is safe, elicits protective levels of IgG anti-Vi, and is compatible with routine infant vaccines. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:730-5. [PMID: 21411598 DOI: 10.1128/cvi.00532-10] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Typhoid fever remains a serious problem in developing countries. Current vaccines are licensed for individuals who are 5 years old or older. A conjugate of the capsular polysaccharide (CP) of Salmonella enterica serovar Typhi (Vi) bound to recombinant exoprotein A of Pseudomonas aeruginosa (Vi-rEPA) enhanced Vi immunogenicity and protected 2- to 5-year-olds in Vietnam. In this study, Vi-rEPA was evaluated for use in infants. A total of 301 full-term Vietnamese infants received Expanded Program on Immunization (EPI) vaccines alone or with Vi-rEPA or Haemophilus influenzae type b-tetanus toxoid conjugate (Hib-TT) at 2, 4, and 6 months and Vi-rEPA or Hib-TT alone at 12 months. Infants were visited 6, 24, and 48 h after each injection to monitor adverse reactions. Maternal, cord, and infant sera were assayed for IgG anti-Vi and for IgG antibodies to Hib CP and the diphtheria, tetanus, and pertussis toxins at 7, 12, and 13 months. No vaccine-related serious adverse reactions occurred. In the Vi-rEPA group, the IgG anti-Vi geometric mean (GM) increased from the cord level of 0.66 to 17.4 enzyme-linked immunosorbent assay units (EU) at 7 months, declined to 4.76 EU at 12 months, and increased to 50.1 EU 1 month after the 4th dose (95% of infants had levels of ≥ 3.5 EU, the estimated protective level). Controls had no increase of the IgG anti-Vi GM. Infants with cord anti-Vi levels of <3.5 EU responded with significantly higher IgG anti-Vi levels than those with levels of ≥ 3.5 EU. Anti-diphtheria, -tetanus, and -pertussis toxin levels were similar in all groups. Vi-rEPA was safe, induced protective anti-Vi levels, and was compatible with EPI vaccines, and it can be used in infants. High cord IgG anti-Vi levels partially suppressed infant responses to Vi-rEPA.
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Johanns TM, Ertelt JM, Rowe JH, Way SS. Regulatory T cell suppressive potency dictates the balance between bacterial proliferation and clearance during persistent Salmonella infection. PLoS Pathog 2010; 6:e1001043. [PMID: 20714351 PMCID: PMC2920851 DOI: 10.1371/journal.ppat.1001043] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Accepted: 07/13/2010] [Indexed: 12/31/2022] Open
Abstract
The pathogenesis of persistent infection is dictated by the balance between opposing immune activation and suppression signals. Herein, virulent Salmonella was used to explore the role and potential importance of Foxp3-expressing regulatory T cells in dictating the natural progression of persistent bacterial infection. Two distinct phases of persistent Salmonella infection are identified. In the first 3-4 weeks after infection, progressively increasing bacterial burden was associated with delayed effector T cell activation. Reciprocally, at later time points after infection, reductions in bacterial burden were associated with robust effector T cell activation. Using Foxp3(GFP) reporter mice for ex vivo isolation of regulatory T cells, we demonstrate that the dichotomy in infection tempo between early and late time points is directly paralleled by drastic changes in Foxp3(+) Treg suppressive potency. In complementary experiments using Foxp3(DTR) mice, the significance of these shifts in Treg suppressive potency on infection outcome was verified by enumerating the relative impacts of regulatory T cell ablation on bacterial burden and effector T cell activation at early and late time points during persistent Salmonella infection. Moreover, Treg expression of CTLA-4 directly paralleled changes in suppressive potency, and the relative effects of Treg ablation could be largely recapitulated by CTLA-4 in vivo blockade. Together, these results demonstrate that dynamic regulation of Treg suppressive potency dictates the course of persistent bacterial infection.
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Affiliation(s)
- Tanner M. Johanns
- Departments of Pediatrics and Microbiology, University of Minnesota School of Medicine, Center for Microbiology and Infectious Disease Translational Research, Minneapolis, Minnesota, United States of America
| | - James M. Ertelt
- Departments of Pediatrics and Microbiology, University of Minnesota School of Medicine, Center for Microbiology and Infectious Disease Translational Research, Minneapolis, Minnesota, United States of America
| | - Jared H. Rowe
- Departments of Pediatrics and Microbiology, University of Minnesota School of Medicine, Center for Microbiology and Infectious Disease Translational Research, Minneapolis, Minnesota, United States of America
| | - Sing Sing Way
- Departments of Pediatrics and Microbiology, University of Minnesota School of Medicine, Center for Microbiology and Infectious Disease Translational Research, Minneapolis, Minnesota, United States of America
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Characterization of anti-Salmonella enterica serotype Typhi antibody responses in bacteremic Bangladeshi patients by an immunoaffinity proteomics-based technology. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1188-95. [PMID: 20573880 DOI: 10.1128/cvi.00104-10] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Salmonella enterica serotype Typhi is the cause of typhoid fever and a human-restricted pathogen. Currently available typhoid vaccines provide 50 to 90% protection for 2 to 5 years, and available practical diagnostic assays to identify individuals with typhoid fever lack sensitivity and/or specificity. Identifying immunogenic S. Typhi antigens expressed during human infection could lead to improved diagnostic assays and vaccines. Here we describe a platform immunoaffinity proteomics-based technology (IPT) that involves the use of columns charged with IgG, IgM, or IgA antibody fractions recovered from humans bacteremic with S. Typhi to capture S. Typhi proteins that were subsequently identified by mass spectrometry. This screening tool identifies immunogenic proteins recognized by antibodies from infected hosts. Using this technology and the plasma of patients with S. Typhi bacteremia in Bangladesh, we identified 57 proteins of S. Typhi, including proteins known to be immunogenic (PagC, HlyE, OmpA, and GroEL) and a number of proteins present in the human-restricted serotypes S. Typhi and S. Paratyphi A but rarely found in broader-host-range Salmonella spp. (HlyE, CdtB, PltA, and STY1364). We categorized identified proteins into a number of major groupings, including those involved in energy metabolism, protein synthesis, iron homeostasis, and biosynthetic and metabolic functions and those predicted to localize to the outer membrane. We assessed systemic and mucosal anti-HlyE responses in S. Typhi-infected patients and detected anti-HlyE responses at the time of clinical presentation in patients but not in controls. These findings could assist in the development of improved diagnostic assays.
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Muniz-Junqueira MI, Tosta CE, Prata A. [Schistosoma-associated chronic septicemic salmonellosis: evolution of knowledge and immunopathogenic mechanisms]. Rev Soc Bras Med Trop 2010; 42:436-45. [PMID: 19802482 DOI: 10.1590/s0037-86822009000400015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 07/20/2009] [Indexed: 11/21/2022] Open
Abstract
Chronic septicemic salmonellosis is an individualized clinical entity characterized by prolonged fever with enlargement of the liver and spleen that occurs in Schistosoma-infected individuals who are coinfected with Salmonella. Several immunopathogenic mechanisms are involved, and they depend on the peculiarities of the interactions between Salmonella and various species of the genus Schistosoma. The modifications to the immune system that are caused by parasite infection are responsible for the evolution of the disease. In this review, we analyze the evolution of the knowledge on this entity and discuss the possible immuno-physiopathogenic mechanisms that contribute towards its development.
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Transcriptional response in the peripheral blood of patients infected with Salmonella enterica serovar Typhi. Proc Natl Acad Sci U S A 2009; 106:22433-8. [PMID: 20018727 DOI: 10.1073/pnas.0912386106] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We used microarrays and transcriptional profiling of peripheral blood to investigate the host response of 29 individuals who contracted typhoid fever in the Mekong Delta region of Vietnam. Samples were taken over a nine month period encompassing acute disease, convalescence, and recovery. We found that typhoid fever induced a distinct and highly reproducible signature in the peripheral blood that changed during treatment and convalescence, returning in the majority of cases to the "normal" profile as measured in healthy uninfected controls. Unexpectedly, there was a strong, distinct signature of convalescence present at day 9 after infection that remained virtually unchanged one month after acute infection and in some cases persisted as long as nine months despite a complete clinical recovery in all patients. Patients who retain the convalescent signature may be genetically or temporarily incapable of developing an effective immune response and may be more susceptible to reinfection, relapse, or the establishment of a carrier state.
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Role of Nod1 in mucosal dendritic cells during Salmonella pathogenicity island 1-independent Salmonella enterica serovar Typhimurium infection. Infect Immun 2009; 77:4480-6. [PMID: 19620349 DOI: 10.1128/iai.00519-09] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Recent advances in immunology have highlighted the critical function of pattern-recognition molecules (PRMs) in generating the innate immune response to effectively target pathogens. Nod1 and Nod2 are intracellular PRMs that detect peptidoglycan motifs from the cell walls of bacteria once they gain access to the cytosol. Salmonella enterica serovar Typhimurium is an enteric intracellular pathogen that causes a severe disease in the mouse model. This pathogen resides within vacuoles inside the cell, but the question of whether cytosolic PRMs such as Nod1 and Nod2 could have an impact on the course of S. Typhimurium infection in vivo has not been addressed. Here, we show that deficiency in the PRM Nod1, but not Nod2, resulted in increased susceptibility toward a mutant strain of S. Typhimurium that targets directly lamina propria dendritic cells (DCs) for its entry into the host. Using this bacterium and bone marrow chimeras, we uncovered a surprising role for Nod1 in myeloid cells controlling bacterial infection at the level of the intestinal lamina propria. Indeed, DCs deficient for Nod1 exhibited impaired clearance of the bacteria, both in vitro and in vivo, leading to increased organ colonization and decreased host survival after oral infection. Taken together, these findings demonstrate a key role for Nod1 in the host response to an enteric bacterial pathogen through the modulation of intestinal lamina propria DCs.
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Gil-Cruz C, Bobat S, Marshall JL, Kingsley RA, Ross EA, Henderson IR, Leyton DL, Coughlan RE, Khan M, Jensen KT, Buckley CD, Dougan G, MacLennan ICM, López-Macías C, Cunningham AF. The porin OmpD from nontyphoidal Salmonella is a key target for a protective B1b cell antibody response. Proc Natl Acad Sci U S A 2009; 106:9803-8. [PMID: 19487686 PMCID: PMC2701014 DOI: 10.1073/pnas.0812431106] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Indexed: 12/23/2022] Open
Abstract
Invasive nontyphoidal Salmonella (NTS), including Salmonella typhimurium (STm), are major yet poorly-recognized killers of infants in sub-Saharan Africa. Death in these children is usually associated with bacteremia, commonly in the absence of gastrointestinal symptoms. Evidence from humans and animal studies suggest that severe infection and bacteremia occur when specific Ab is lacking. Understanding how Ab responses to Salmonella are regulated will help develop vaccines against these devastating infections. STm induces atypical Ab responses characterized by prominent, accelerated, extrafollicular T-independent (TI) Ab against a range of surface antigens. These responses develop without concomitant germinal centers, which only appear as infection resolves. Here, we show STm rapidly induces a population of TI B220(+)CD5(-) B1b cells during infection and TI Ab from B1b cells targets the outer membrane protein (Omp) porins OmpC, OmpD and OmpF but not flagellin. When porins are used as immunogens they can ablate bacteremia and provide equivalent protection against STm as killed bacterial vaccine and this is wholly B cell-dependent. Furthermore Ab from porin-immunized chimeras, that have B1b cells, is sufficient to impair infection. Infecting with porin-deficient bacteria identifies OmpD, a protein absent from Salmonella Typhi, as a key target of Ab in these infections. This work broadens the recognized repertoire of TI protein antigens and highlights the importance of Ab from different B cell subsets in controlling STm infection. OmpD is a strong candidate vaccine target and may, in part, explain the lack of cross-protection between Salmonella Typhi and STm infections.
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Affiliation(s)
- Cristina Gil-Cruz
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre “Siglo XXI” Mexican Institute for Social Security, Mexico City, Mexico
- Ph.D. Program on Immunology, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City; and
| | - Saeeda Bobat
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Jennifer L. Marshall
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Robert A. Kingsley
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Ewan A. Ross
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | | | - Ruth E. Coughlan
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Mahmood Khan
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | | | - Christopher D. Buckley
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Ian C. M. MacLennan
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Constantino López-Macías
- Medical Research Unit on Immunochemistry, Specialties Hospital, National Medical Centre “Siglo XXI” Mexican Institute for Social Security, Mexico City, Mexico
| | - Adam F. Cunningham
- School of Immunity and Infection and
- Medical Research Council Centre for Immune Regulation, University of Birmingham, Birmingham B15 2TT, United Kingdom
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