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Takeuchi N, Ohkusu M, Kusuya Y, Takahashi H, Yamaguchi M, Omata Y, Nakazawa T, Ishiwada N. Comparative genomic and morphological analyses of capsular and capsular-deficient pneumococcal strains simultaneously isolated from a patient with invasive pneumococcal disease. J Infect Chemother 2024:S1341-321X(24)00210-1. [PMID: 39111665 DOI: 10.1016/j.jiac.2024.08.001] [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: 09/05/2023] [Revised: 07/16/2024] [Accepted: 08/02/2024] [Indexed: 08/18/2024]
Abstract
INTRODUCTION To understand the in-vivo dynamics in pneumococci, investigation into the carriage in patients with invasive pneumococcal disease (IPD) is extremely important. METHODS To clarify genomic and morphological differences between pneumococcal strains simultaneously isolated from different sites in a patient with IPD, we conducted comparative analyses of two strains. A capsular strain isolated from the blood and a non-capsular strain isolated from the sputum of a patient with IPD were used. RESULTS The strain isolated from blood was serotype 24B with capsule. The strain isolated from sputum with capsular type 24 genes was non-encapsulated, and genomic analysis revealed an insertion region in the wcxK gene. Its biofilm-forming capacity was higher than that of the capsular strain, as was that of the pspK-positive true non-encapsulated strain. Furthermore, observing the microbe using transmission electron microscopy revealed that the strain isolated from sputum lacked a capsule, like the pspK-positive true non-encapsulated strain. CONCLUSIONS Our analysis of the two strains isolated from the blood and sputum of a patient with IPD showed one possible in-vivo morphological change in Streptococcus pneumoniae.
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Affiliation(s)
- Noriko Takeuchi
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan.
| | - Misako Ohkusu
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Yoko Kusuya
- Medical Mycology Research Center, Chiba University, Chiba, Japan; Biological Resource Center, National Institute of Technology and Evaluation, Chiba, Japan
| | - Hiroki Takahashi
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | | | - Yuko Omata
- Department of Pediatrics, Seikeikai Chiba Medical Centre, Chiba, Japan
| | - Tomoko Nakazawa
- Department of Pediatrics, Seikeikai Chiba Medical Centre, Chiba, Japan
| | - Naruhiko Ishiwada
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan
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Mushunje PK, Dube FS, Olwagen C, Madhi S, Odland JØ, Ferrand RA, Nicol MP, Abotsi RE. Characterization of bacterial and viral pathogens in the respiratory tract of children with HIV-associated chronic lung disease: a case-control study. BMC Infect Dis 2024; 24:637. [PMID: 38926682 PMCID: PMC11201860 DOI: 10.1186/s12879-024-09540-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Accepted: 06/19/2024] [Indexed: 06/28/2024] Open
Abstract
INTRODUCTION Chronic lung disease is a major cause of morbidity in African children with HIV infection; however, the microbial determinants of HIV-associated chronic lung disease (HCLD) remain poorly understood. We conducted a case-control study to investigate the prevalence and densities of respiratory microbes among pneumococcal conjugate vaccine (PCV)-naive children with (HCLD +) and without HCLD (HCLD-) established on antiretroviral treatment (ART). METHODS Nasopharyngeal swabs collected from HCLD + (defined as forced-expiratory-volume/second < -1.0 without reversibility postbronchodilation) and age-, site-, and duration-of-ART-matched HCLD- participants aged between 6-19 years enrolled in Zimbabwe and Malawi (BREATHE trial-NCT02426112) were tested for 94 pneumococcal serotypes together with twelve bacteria, including Streptococcus pneumoniae (SP), Staphylococcus aureus (SA), Haemophilus influenzae (HI), Moraxella catarrhalis (MC), and eight viruses, including human rhinovirus (HRV), respiratory syncytial virus A or B, and human metapneumovirus, using nanofluidic qPCR (Standard BioTools formerly known as Fluidigm). Fisher's exact test and logistic regression analysis were used for between-group comparisons and risk factors associated with common respiratory microbes, respectively. RESULTS A total of 345 participants (287 HCLD + , 58 HCLD-; median age, 15.5 years [IQR = 12.8-18], females, 52%) were included in the final analysis. The prevalence of SP (40%[116/287] vs. 21%[12/58], p = 0.005) and HRV (7%[21/287] vs. 0%[0/58], p = 0.032) were higher in HCLD + participants compared to HCLD- participants. Of the participants positive for SP (116 HCLD + & 12 HCLD-), 66% [85/128] had non-PCV-13 serotypes detected. Overall, PCV-13 serotypes (4, 19A, 19F: 16% [7/43] each) and NVT 13 and 21 (9% [8/85] each) predominated. The densities of HI (2 × 104 genomic equivalents [GE/ml] vs. 3 × 102 GE/ml, p = 0.006) and MC (1 × 104 GE/ml vs. 1 × 103 GE/ml, p = 0.031) were higher in HCLD + compared to HCLD-. Bacterial codetection (≥ any 2 bacteria) was higher in the HCLD + group (36% [114/287] vs. (19% [11/58]), (p = 0.014), with SP and HI codetection (HCLD + : 30% [86/287] vs. HCLD-: 12% [7/58], p = 0.005) predominating. Viruses (predominantly HRV) were detected only in HCLD + participants. Lastly, participants with a history of previous tuberculosis treatment were more likely to carry SP (adjusted odds ratio (aOR): 1.9 [1.1 -3.2], p = 0.021) or HI (aOR: 2.0 [1.2 - 3.3], p = 0.011), while those who used ART for ≥ 2 years were less likely to carry HI (aOR: 0.3 [0.1 - 0.8], p = 0.005) and MC (aOR: 0.4 [0.1 - 0.9], p = 0.039). CONCLUSION Children with HCLD + were more likely to be colonized by SP and HRV and had higher HI and MC bacterial loads in their nasopharynx. The role of SP, HI, and HRV in the pathogenesis of CLD, including how they influence the risk of acute exacerbations, should be studied further. TRIAL REGISTRATION The BREATHE trial (ClinicalTrials.gov Identifier: NCT02426112 , registered date: 24 April 2015).
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Affiliation(s)
- Prince K Mushunje
- Department of Molecular and Cell Biology & Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
| | - Felix S Dube
- Department of Molecular and Cell Biology & Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- School of Medicine, University of Lusaka, Lusaka, Zambia
| | - Courtney Olwagen
- South Africa Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir Madhi
- South Africa Medical Research Council Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Infectious Diseases and Oncology Research Institute, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jon Ø Odland
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
- International Research Laboratory for Reproductive Ecotoxicology (IL RET), The National Research University Higher School of Economics, Moscow, Russia
- School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - Rashida A Ferrand
- Biomedical Research and Training Institute, Harare, Zimbabwe
- Clinical Research Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Mark P Nicol
- Marshall Centre, Division of Infection and Immunity, School of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Western Australia, Perth, Australia
| | - Regina E Abotsi
- Department of Molecular and Cell Biology & Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Pharmaceutical Microbiology, School of Pharmacy, University of Health and Allied Sciences, Ho, Ghana
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Obolski U, Swarthout TD, Kalizang'oma A, Mwalukomo TS, Chan JM, Weight CM, Brown C, Cave R, Cornick J, Kamng'ona AW, Msefula J, Ercoli G, Brown JS, Lourenço J, Maiden MC, French N, Gupta S, Heyderman RS. The metabolic, virulence and antimicrobial resistance profiles of colonising Streptococcus pneumoniae shift after PCV13 introduction in urban Malawi. Nat Commun 2023; 14:7477. [PMID: 37978177 PMCID: PMC10656543 DOI: 10.1038/s41467-023-43160-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/02/2023] [Indexed: 11/19/2023] Open
Abstract
Streptococcus pneumoniae causes substantial mortality among children under 5-years-old worldwide. Polysaccharide conjugate vaccines (PCVs) are highly effective at reducing vaccine serotype disease, but emergence of non-vaccine serotypes and persistent nasopharyngeal carriage threaten this success. We investigated the hypothesis that following vaccine, adapted pneumococcal genotypes emerge with the potential for vaccine escape. We genome sequenced 2804 penumococcal isolates, collected 4-8 years after introduction of PCV13 in Blantyre, Malawi. We developed a pipeline to cluster the pneumococcal population based on metabolic core genes into "Metabolic genotypes" (MTs). We show that S. pneumoniae population genetics are characterised by emergence of MTs with distinct virulence and antimicrobial resistance (AMR) profiles. Preliminary in vitro and murine experiments revealed that representative isolates from emerging MTs differed in growth, haemolytic, epithelial infection, and murine colonisation characteristics. Our results suggest that in the context of PCV13 introduction, pneumococcal population dynamics had shifted, a phenomenon that could further undermine vaccine control and promote spread of AMR.
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Affiliation(s)
- Uri Obolski
- Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
- Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel.
| | - Todd D Swarthout
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands
| | - Akuzike Kalizang'oma
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom
| | | | - Jia Mun Chan
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom
| | - Caroline M Weight
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom
- Faculty of Health and Medicine, Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Comfort Brown
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
| | - Rory Cave
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom
| | - Jen Cornick
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi
- Clinical Infection, Microbiology and Immunology, Institute of Infection Veterinary & Ecological Science, University of Liverpool, Liverpool, United Kingdom
| | | | | | - Giuseppe Ercoli
- UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Jeremy S Brown
- UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - José Lourenço
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- Universidade Católica Portuguesa, Faculty of Medicine, Biomedical Research Centre, Lisbon, Portugal
| | - Martin C Maiden
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Neil French
- Clinical Infection, Microbiology and Immunology, Institute of Infection Veterinary & Ecological Science, University of Liverpool, Liverpool, United Kingdom
| | - Sunetra Gupta
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Robert S Heyderman
- Malawi Liverpool Wellcome Programme, Blantyre, Malawi.
- Mucosal Pathogens Research Group, Research Department of Infection, Division of Infection & Immunity, University College London, London, United Kingdom.
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Hackman J, Sheppard C, Phelan J, Jones-Warner W, Sobkowiak B, Shah S, Litt D, Fry NK, Toizumi M, Yoshida LM, Hibberd M, Miller E, Flasche S, Hué S. Phylogenetic inference of pneumococcal transmission from cross-sectional data, a pilot study. Wellcome Open Res 2023; 8:427. [PMID: 38638914 PMCID: PMC11024593 DOI: 10.12688/wellcomeopenres.19219.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2023] [Indexed: 04/20/2024] Open
Abstract
Background: Inference on pneumococcal transmission has mostly relied on longitudinal studies which are costly and resource intensive. Therefore, we conducted a pilot study to test the ability to infer who infected whom from cross-sectional pneumococcal sequences using phylogenetic inference. Methods: Five suspected transmission pairs, for which there was epidemiological evidence of who infected whom, were selected from a household study. For each pair, Streptococcus pneumoniae full genomes were sequenced from nasopharyngeal swabs collected on the same day. The within-host genetic diversity of the pneumococcal population was used to infer the transmission direction and then cross-validated with the direction suggested by the epidemiological records. Results: The pneumococcal genomes clustered into the five households from which the samples were taken. The proportion of concordantly inferred transmission direction generally increased with increasing minimum genome fragment size and single nucleotide polymorphisms. We observed a larger proportion of unique polymorphic sites in the source bacterial population compared to that of the recipient in four of the five pairs, as expected in the case of a transmission bottleneck. The only pair that did not exhibit this effect was also the pair that had consistent discordant transmission direction compared to the epidemiological records suggesting potential misdirection as a result of false-negative sampling. Conclusions: This pilot provided support for further studies to test if the direction of pneumococcal transmission can be reliably inferred from cross-sectional samples if sequenced with sufficient depth and fragment length.
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Affiliation(s)
- Jada Hackman
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Carmen Sheppard
- Vaccine Preventable Bacteria Section, UK Health Security Agency, London, UK
| | - Jody Phelan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - William Jones-Warner
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Ben Sobkowiak
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Sonal Shah
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - David Litt
- Vaccine Preventable Bacteria Section, UK Health Security Agency, London, UK
| | - Norman K. Fry
- Vaccine Preventable Bacteria Section, UK Health Security Agency, London, UK
- Immunisation & Countermeasures Division, UK Health Security Agency, London, UK
| | - Michiko Toizumi
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Paediatric Infectious Diseases, Nagasaki University, Nagasaki, Japan
| | - Lay-Myint Yoshida
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Paediatric Infectious Diseases, Nagasaki University, Nagasaki, Japan
| | - Martin Hibberd
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Elizabeth Miller
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Stefan Flasche
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Stéphane Hué
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
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Nkhoma SC, Ahmed AOA, Porier D, Rashid S, Bradford R, Molestina RE, Stedman TT. Dynamics of parasite growth in genetically diverse Plasmodium falciparum isolates. Mol Biochem Parasitol 2023; 254:111552. [PMID: 36731750 PMCID: PMC10149587 DOI: 10.1016/j.molbiopara.2023.111552] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/24/2022] [Accepted: 01/26/2023] [Indexed: 02/01/2023]
Abstract
Multiple parasite lineages with different proliferation rates or fitness may coexist within a clinical malaria isolate, resulting in complex growth interactions and variations in phenotype. To elucidate the dynamics of parasite growth in multiclonal isolates, we measured growth rates (GRs) of three Plasmodium falciparum Cambodian isolates, including IPC_3445 (MRA-1236), IPC_5202 (MRA-1240), IPC_6403 (MRA-1285), and parasite lineages previously cloned from each of these isolates by limiting dilution. Following synchronization, in vitro cultures of each parasite line were maintained over four consecutive asexual cycles (192 h), with thin smears prepared at each 48-h cycle to estimate GR and fold change in parasitemia (FCP). Cell cycle time (CCT), the duration it takes for ring-stage parasites to develop into mature schizonts, was measured by monitoring the development of 0-3-h post-invasion rings for up to 52 h post-incubation. Laboratory lines 3D7 (MRA-102) and Dd2 (MRA-150) were used as controls. Significant differences in GR, FCP, and CCT were observed between parasite isolates and clonal lineages from each isolate. The parasite lines studied here have well-defined growth phenotypes and will facilitate basic malaria research and development of novel malaria interventions. These lines are available to malaria researchers through the MR4 collection of NIAID's BEI Resources Program.
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Affiliation(s)
- Standwell C Nkhoma
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA.
| | - Amel O A Ahmed
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
| | - Danielle Porier
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
| | - Sujatha Rashid
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
| | - Rebecca Bradford
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
| | - Robert E Molestina
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
| | - Timothy T Stedman
- BEI Resources, American Type Culture Collection, 10801 University Boulevard, Manassas, VA 20110-2209, USA
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Adamu AL, Ojal J, Abubakar IA, Odeyemi KA, Bello MM, Okoromah CAN, Karia B, Karani A, Akech D, Inem V, Scott JAG, Adetifa IMO. The impact of introduction of the 10-valent pneumococcal conjugate vaccine on pneumococcal carriage in Nigeria. Nat Commun 2023; 14:2666. [PMID: 37160867 PMCID: PMC10169786 DOI: 10.1038/s41467-023-38277-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/24/2023] [Indexed: 05/11/2023] Open
Abstract
Pneumococcal conjugate vaccines (PCVs) protect against invasive pneumococcal disease (IPD) among vaccinees. However, at population level, this protection is driven by indirect effects. PCVs prevent nasopharyngeal acquisition of vaccine-serotype (VT) pneumococci, reducing onward transmission. Each disease episode is preceded by infection from a carrier, so vaccine impacts on carriage provide a minimum estimate of disease reduction in settings lacking expensive IPD surveillance. We documented carriage prevalence and vaccine coverage in two settings in Nigeria annually (2016-2020) following PCV10 introduction in 2016. Among 4,684 rural participants, VT carriage prevalence fell from 21 to 12% as childhood (<5 years) vaccine coverage rose from 7 to 84%. Among 2,135 urban participants, VT carriage prevalence fell from 16 to 9% as uptake rose from 15 to 94%. Within these ranges, carriage prevalence declined with uptake. Increasing PCV10 coverage reduced pneumococcal infection at all ages, implying at least a comparable reduction in IPD.
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Affiliation(s)
- Aishatu L Adamu
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
- Department of Infectious Diseases Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
- Department of Community Medicine, College of Health Sciences, Bayero University, Kano/Aminu Kano Teaching Hospital, Kano, Nigeria.
| | - J Ojal
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Infectious Diseases Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Isa A Abubakar
- Department of Community Medicine, College of Health Sciences, Bayero University, Kano/Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Kofo A Odeyemi
- Department of Community Medicine and Primary Care, College of Medicine, University of Lagos, Lagos, Nigeria
| | - Musa M Bello
- Department of Community Medicine, College of Health Sciences, Bayero University, Kano/Aminu Kano Teaching Hospital, Kano, Nigeria
| | - Christy A N Okoromah
- Department of Paediatrics and Child Health, College of Medicine, University of Lagos, Lagos, Nigeria
| | | | - Angela Karani
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Donald Akech
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Victor Inem
- Department of Community Medicine and Primary Care, College of Medicine, University of Lagos, Lagos, Nigeria
| | - J Anthony G Scott
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Infectious Diseases Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Ifedayo M O Adetifa
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Department of Infectious Diseases Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
- Department of Paediatrics and Child Health, College of Medicine, University of Lagos, Lagos, Nigeria
- Nigeria Centre for Disease Control, Abuja, Nigeria
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Jagne I, von Mollendorf C, Wee-Hee A, Ortika B, Satzke C, Russell FM. A systematic review of pneumococcal conjugate vaccine impact on pneumococcal nasopharyngeal colonisation density in children under 5 years of age. Vaccine 2023; 41:3028-3037. [PMID: 37032228 DOI: 10.1016/j.vaccine.2023.03.063] [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: 08/16/2022] [Revised: 03/18/2023] [Accepted: 03/29/2023] [Indexed: 04/11/2023]
Abstract
BACKGROUND High pneumococcal carriage density has been associated with severe pneumonia in some settings. The impact of pneumococcal conjugate vaccines (PCVs) on pneumococcal carriage density has been variable. The aim of this systematic literature review is to describe the effect of PCV7, PCV10 and PCV13 on pneumococcal colonisation density in children under five years old. METHODS We included peer reviewed English literature published between 2000 and 2021 to identify relevant articles using Embase, Medline and PubMed. Original research articles of any study design in countries where PCV has been introduced/studied were included. Quality (risk) assessment was performed using tools developed by the National Heart Brain and Lung Institute for inclusion in this review. We used a narrative synthesis to present results. RESULTS Ten studies were included from 1941 articles reviewed. There were two randomised controlled trials, two cluster randomised trials, one case control study, one retrospective cohort study and four cross sectional studies. Three studies used semiquantitative culture methods to determine density while the remaining studies used quantitative molecular techniques. Three studies reported an increase in density and three studies found a decrease in density among vaccinated compared with unvaccinated children. Four studies found no effect. There was considerable heterogeneity in the study populations, study design and laboratory methods. CONCLUSION There was no consensus regarding the impact of PCV on pneumococcal nasopharyngeal density. We recommend the use of standardised methods to evaluate PCV impact on density.
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Affiliation(s)
- Isatou Jagne
- Asia-Pacific Health, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
| | - Claire von Mollendorf
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia; New Vaccines, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Ashleigh Wee-Hee
- Translational Microbiology, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Belinda Ortika
- Translational Microbiology, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Catherine Satzke
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia; Translational Microbiology, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Fiona M Russell
- Asia-Pacific Health, Infection & Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
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8
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Mutua TM, Kulohoma BW. Differences in genetic flux in invasive Streptococcus pneumoniae associated with bacteraemia and meningitis. Heliyon 2022; 8:e12229. [PMID: 36593853 PMCID: PMC9803773 DOI: 10.1016/j.heliyon.2022.e12229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/07/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
Background Genetic flux, a crucial process of pneumococcal evolution, is an essential aspect of bacterial physiology during human pathogenesis. However, the role of these genetic changes and the selective forces that drive them is not fully understood. Elucidating the underlying selective forces that determine the magnitude and direction (gene gain or loss) of gene transfer is important for better understanding the pathogenesis process, and may also highlight potential therapeutic and diagnostic targets. Methods Here, we leveraged data from high throughput genome sequencing and robust probabilistic models to discover the magnitude and likely direction of genetic flux events, but not the source, in 209 multi-lineage invasive pneumococcal genomes generated from blood (n = 147) and CSF (n = 62) isolates, associated with bacteremia and meningitis respectively. The Gain and Loss Mapping Engine (GLOOME) was used to infer gene gain and loss more accurately by taking into account differences in rates of gene gain and loss among gene families, as well as independent evolution within and across lineages. Results Our results show the likely extent and direction of gene fluctuations at different niche, during pneumococcal pathogenesis, highlighting that evolutionary dynamics are important for tissue-specific host invasion and survival. Conclusion These findings improve insights on evolutionary dynamics during invasive pneumococcal disease, and highlight potential diagnostic and therapeutic targets.
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Sheppard CL, Manna S, Groves N, Litt DJ, Amin-Chowdhury Z, Bertran M, Ladhani S, Satzke C, Fry NK. PneumoKITy: A fast, flexible, specific, and sensitive tool for Streptococcus pneumoniae serotype screening and mixed serotype detection from genome sequence data. Microb Genom 2022; 8:mgen000904. [PMID: 36748701 PMCID: PMC9837567 DOI: 10.1099/mgen.0.000904] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Determination of serotypes of Streptococcus pneumoniae is essential for monitoring current vaccine programmes. Since October 2017, pneumococcal serotypes in England have been derived from whole genome sequencing (WGS) data using our bioinformatic tool PneumoCaT. That tool was designed for serotype determination from pure cultures in a reference laboratory. To help determine multiple serotypes in pneumococcal carriage samples, we developed a new software tool named PneumoKITy (Pneumococcal K-mer Integrated Typing) that uses the powerful Mash k-mer screening method for pneumococcal serotyping. Mash k-mer screening is more sequence specific and much faster than the mapping method used in PneumoCaT and can determine 54 (58.1 %) of the 93 serotypes in the SSI Diagnostica phenotypical serotyping scheme to type level with the remainder called to serogroup or subgroup level (e.g., 11A/D). PneumoKITy can be run on both FastQ and assembly input, requiring up to 11× less memory and running up to 29× faster than the current version of PneumoCaT (1.2.1) on FastQ files. PneumoKITy can be used as a rapid, flexible serotype screening method which adds sensitive detection of mixed serotypes, e.g., for nasopharyngeal carriage studies where the presence of multiple serotypes is common. PneumoKITy's ability to function from assembly file, for pure culture serotype detection, increases its speed. This speed potentially enables the software to be run using low infrastructure overhead via web-based platforms. PneumoKITy could be used as a fast initial screening method with other tools used for those serotypes that could not be fully determined to type level if necessary. PneumoKITy was found to be highly accurate and sensitive when run on a panel of FastQ files derived from mixed cultures with all serotypes in 47/51 (92.2 %) of samples being accurately detected. PneumoKITy was also able to accurately estimate the relative abundance of serotypes in the same sample. Estimates being within a mean relative abundance of 1.5 % of the expected abundance in mixtures with known concentrations. PneumoKITy was able to detect minor serotypes with expected abundance of 1 % in the known mixture serotypes. PneumoKITy is a rapid, flexible tool with wide-ranging applications outside of the pure-culture, reference laboratory serotyping remit of PneumoCaT.
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Affiliation(s)
- Carmen L. Sheppard
- Vaccine Preventable Bacteria Section, Respiratory and Vaccine Preventable Bacteria Reference Unit, UK Health Security Agency, London NW9 5EQ, UK,Present address: Genpax Ltd, 9 Pembridge Road, Notting Hill, London, W11 3JY, UK
| | - Sam Manna
- Translational Microbiology Group, Murdoch Children’s Research Institute, The University of Melbourne Department of Paediatrics at the Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Natalie Groves
- Respiratory and Vaccine Preventable Bacteria Reference Unit, UK Health Security Agency, London NW9 5EQ, UK
| | - David J. Litt
- Vaccine Preventable Bacteria Section, Respiratory and Vaccine Preventable Bacteria Reference Unit, UK Health Security Agency, London NW9 5EQ, UK
| | - Zahin Amin-Chowdhury
- Immunisation and Vaccine Preventable Diseases, UK Health Security Agency, London NW9 5EQ, UK
| | - Marta Bertran
- Immunisation and Vaccine Preventable Diseases, UK Health Security Agency, London NW9 5EQ, UK
| | - Shamez Ladhani
- Immunisation and Vaccine Preventable Diseases, UK Health Security Agency, London NW9 5EQ, UK
| | - Catherine Satzke
- Translational Microbiology Group, Murdoch Children’s Research Institute, The University of Melbourne Department of Paediatrics at the Royal Children’s Hospital, Parkville, Victoria, Australia
| | - Norman K. Fry
- Vaccine Preventable Bacteria Section, Respiratory and Vaccine Preventable Bacteria Reference Unit, UK Health Security Agency, London NW9 5EQ, UK,Immunisation and Vaccine Preventable Diseases, UK Health Security Agency, London NW9 5EQ, UK,*Correspondence: Norman K. Fry,
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10
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Thindwa D, Mwalukomo TS, Msefula J, Jambo KC, Brown C, Kamng’ona A, Mwansambo C, Ojal J, Flasche S, French N, Heyderman RS, Swarthout TD. Risk factors for pneumococcal carriage in adults living with HIV on antiretroviral therapy in the infant pneumococcal vaccine era in Malawi. AIDS 2022; 36:2045-2055. [PMID: 35983828 PMCID: PMC10503545 DOI: 10.1097/qad.0000000000003365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Adults living with HIV (ALWHIV) on antiretroviral therapy (ART) are at high risk of pneumococcal carriage and disease. To help evaluate carriage risk in African ALWHIV at least 4 years after infant pneumococcal conjugate vaccination introduction in 2011, we assessed association between pneumococcal carriage and potential risk factors. METHODS Nasopharyngeal swabs were collected from adults aged 18-40 years attending an ART clinic during rolling, cross-sectional surveys in Blantyre, Malawi between 2015 and 2019. We fitted generalized additive models to estimate the risk of sex, social economic status (SES), living with a child less than 5 years, and ART duration on carriage. RESULTS Of 2067 adults, median age was 33 years (range 28-37), 1427 (69.0%) were women, 1087 (61.4%) were in low-middle socioeconomic-status (SES), 910 (44.0%) were living with a child less than 5 years, and median ART duration was 3 years (range 0.004-17). We estimated 38.2 and 60.6% reductions in overall and vaccine-serotype carriage prevalence. Overall carriage was associated with low SES, living with a child less than 5 years and shorter duration on ART. By contrast, vaccine-type carriage was associated with living without a child less than 5 years and male sex. CONCLUSION Despite temporal reductions in overall and vaccine-serotype carriage, there is evidence of incomplete vaccine-serotype indirect protection. A targeted-vaccination campaign should be considered for ALWHIV, along with other public health measures to further reduce vaccine-serotype carriage and therefore disease.
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Affiliation(s)
- Deus Thindwa
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- Malawi-Liverpool-Wellcome Programme
| | - Thandie S. Mwalukomo
- School of Life Sciences and Allied Health Professions, Department of Biomedical Sciences, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Kondwani C. Jambo
- Malawi-Liverpool-Wellcome Programme
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Arox Kamng’ona
- School of Life Sciences and Allied Health Professions, Department of Biomedical Sciences, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - John Ojal
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- KEMRI-Wellcome Research Programme, Geographic Medicine Centre, Kilifi, Kenya
| | - Stefan Flasche
- Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Neil French
- Institute of Infection, Veterinary and Ecological Science, Department of Clinical Infection, Microbiology, and Immunology, University of Liverpool, Liverpool
| | - Robert S. Heyderman
- Division of Infection and Immunity, Research Department of Infection, NIHR Mucosal Pathogens Research Unit, University College London, London, UK
| | - Todd D. Swarthout
- Malawi-Liverpool-Wellcome Programme
- Division of Infection and Immunity, Research Department of Infection, NIHR Mucosal Pathogens Research Unit, University College London, London, UK
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11
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Lehtinen S, Croucher NJ, Blanquart F, Fraser C. Epidemiological dynamics of bacteriocin competition and antibiotic resistance. Proc Biol Sci 2022; 289:20221197. [PMID: 36196547 PMCID: PMC9532987 DOI: 10.1098/rspb.2022.1197] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bacteriocins, toxic peptides involved in the competition between bacterial strains, are extremely diverse. Previous work on bacteriocin dynamics has highlighted the role of non-transitive 'rock-paper-scissors' competition in maintaining the coexistence of different bacteriocin profiles. The focus to date has primarily been on bacteriocin interactions at the within-host scale (i.e. within a single bacterial population). Yet in species such as Streptococcus pneumoniae, with relatively short periods of colonization and limited within-host diversity, ecological outcomes are also shaped by processes at the epidemiological (between-host) scale. Here, we first investigate bacteriocin dynamics and diversity in epidemiological models. We find that in these models, bacteriocin diversity is more readily maintained than in within-host models, and with more possible combinations of coexisting bacteriocin profiles. Indeed, maintenance of diversity in epidemiological models does not require rock-paper-scissors dynamics; it can also occur through a competition-colonization trade-off. Second, we investigate the link between bacteriocin diversity and diversity at antibiotic resistance loci. Previous work has proposed that bacterial duration of colonization modulates the fitness of antibiotic resistance. Due to their inhibitory effects, bacteriocins are a plausible candidate for playing a role in the duration of colonization episodes. We extend the epidemiological model of bacteriocin dynamics to incorporate an antibiotic resistance locus and demonstrate that bacteriocin diversity can indeed maintain the coexistence of antibiotic-sensitive and -resistant strains.
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Affiliation(s)
- Sonja Lehtinen
- Department of Environmental System Science, Institute for Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Epidemiology, Imperial College London, London, UK
| | - François Blanquart
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France.,Infection Antimicrobials Modelling Evolution, UMR, 1137, INSERM, Université de Paris, Paris, France
| | - Christophe Fraser
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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12
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Dhoubhadel BG, Suzuki M, Ishifuji T, Yaegashi M, Asoh N, Ishida M, Hamaguchi S, Aoshima M, Yasunami M, Ariyoshi K, Morimoto K. High prevalence of multiple serotypes of pneumococci in patients with pneumonia and their associated risk factors. Thorax 2022; 77:thoraxjnl-2021-217979. [PMID: 35474029 PMCID: PMC9606540 DOI: 10.1136/thoraxjnl-2021-217979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 04/03/2022] [Indexed: 12/28/2022]
Abstract
BACKGROUND Multiple serotypes of pneumococci have epidemiological and clinical implications, such as the emergence of non-vaccine serotypes and the acquisition of antimicrobial resistance. Prevalence of multiple serotypes of pneumococci in adults and their risk factors are not known. METHODS We enrolled adult patients from age ≥15 years with radiologically confirmed pneumonia in four hospitals across Japan. Pneumococcal pneumonia was defined with a pneumococcal bacterial density of ≥104/mL in sputum by lytA quantitative PCR, and serotypes were determined. Pneumonias with a single serotype were categorised as single-serotype pneumococcal pneumonia and with two or more serotypes as multiple-serotype pneumococcal pneumonia. Multivariable logistic regression was used to assess the risk factors. RESULTS 3470 patients (median age 77 years, IQR 65-85) were enrolled. Pneumococcal pneumonia was identified in 476 (18.3%, n=2605) patients. Multiple serotypes were detected in 42% of them. Risk of having multiple serotypes was low among patients who had received 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccines (adjusted OR 0.51 (95% CI 0.27 to 0.94)). Proportion of non-PCV7 PPSV23 serotypes in overall distribution of multiple serotypes was 67.4% (n=324/481) compared with 46.4% (n=128/276) in that of single serotypes (p=0.001). Serotypes 5, 9N/9L, 10A, 12/22/46, 17F and 35F were associated with multiple-serotype pneumonia, and serotypes 6A/6B, 23F, 11 and 6C/6D were associated with single-serotype pneumonia. Proportion of more invasive serotypes (serotypes 1, 5, 7F, 8) was significantly higher in multiple-serotype pneumonia (p=0.001). CONCLUSIONS Multiple serotypes of pneumococci are common in sputum of adult patients with pneumonia. The risk of multiple-serotype pneumococcal pneumonia is lower than that of single-serotype pneumococcal pneumonia among PPSV23-vaccinated patients. TRIAL REGISTRATION NUMBER UMIN000006909.
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Affiliation(s)
- Bhim Gopal Dhoubhadel
- Department of Respiratory Infections, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
- Department of Global Health, School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Motoi Suzuki
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tomoko Ishifuji
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Makito Yaegashi
- Department of General Internal Medicine, Kameda Medical Center, Chiba, Japan
| | - Norichika Asoh
- Department of Internal Medicine, Juzenkai Hospital, Nagasaki, Japan
| | - Masayuki Ishida
- Department of Internal Medicine, Chikamori Hospital, Kochi, Japan
| | - Sugihiro Hamaguchi
- Department of General Internal Medicine, Fukushima Medical University, Fukushima, Japan
| | | | - Michio Yasunami
- Life Science Institute, Saga-Ken Medical Centre Koseikan, Saga, Japan
| | - Koya Ariyoshi
- Department of Global Health, School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Konosuke Morimoto
- Department of Respiratory Infections, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
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13
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Senghore M, Chaguza C, Bojang E, Tientcheu PE, Bancroft RE, Lo SW, Gladstone RA, McGee L, Worwui A, Foster-Nyarko E, Ceesay F, Okoi CB, Klugman KP, Breiman RF, Bentley SD, Adegbola R, Antonio M, Hanage WP, Kwambana-Adams BA. Widespread sharing of pneumococcal strains in a rural African setting: proximate villages are more likely to share similar strains that are carried at multiple timepoints. Microb Genom 2022; 8. [PMID: 35119356 PMCID: PMC8942022 DOI: 10.1099/mgen.0.000732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transmission dynamics of Streptococcus pneumoniae in sub-Saharan Africa are poorly understood due to a lack of adequate epidemiological and genomic data. Here we leverage a longitudinal cohort from 21 neighbouring villages in rural Africa to study how closely related strains of S. pneumoniae are shared among infants. We analysed 1074 pneumococcal genomes isolated from 102 infants from 21 villages. Strains were designated for unique serotype and sequence-type combinations, and we arbitrarily defined strain sharing where the pairwise genetic distance between strains could be accounted for by the mean within host intra-strain diversity. We used non-parametric statistical tests to assess the role of spatial distance and prolonged carriage on strain sharing using a logistic regression model. We recorded 458 carriage episodes including 318 (69.4 %) where the carried strain was shared with at least one other infant. The odds of strain sharing varied significantly across villages (χ2=47.5, df=21, P-value <0.001). Infants in close proximity to each other were more likely to be involved in strain sharing, but we also show a considerable amount of strain sharing across longer distances. Close geographic proximity (<5 km) between shared strains was associated with a significantly lower pairwise SNP distance compared to strains shared over longer distances (P-value <0.005). Sustained carriage of a shared strain among the infants was significantly more likely to occur if they resided in villages within a 5 km radius of each other (P-value <0.005, OR 3.7). Conversely, where both infants were transiently colonized by the shared strain, they were more likely to reside in villages separated by over 15 km (P-value <0.05, OR 1.5). PCV7 serotypes were rare (13.5 %) and were significantly less likely to be shared (P-value <0.001, OR −1.07). Strain sharing was more likely to occur over short geographical distances, especially where accompanied by sustained colonization. Our results show that strain sharing is a useful proxy for studying transmission dynamics in an under-sampled population with limited genomic data. This article contains data hosted by Microreact.
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Affiliation(s)
- Madikay Senghore
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia.,Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, 677 Huntington Ave, Boston, MA 02115, USA
| | - Chrispin Chaguza
- Infection Genomics, Wellcome Sanger Institute, Hinxton, UK.,Darwin College, University of Cambridge, Silver Street, Cambridge, UK.,Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Ebrima Bojang
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Peggy-Estelle Tientcheu
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Rowan E Bancroft
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Stephanie W Lo
- Infection Genomics, Wellcome Sanger Institute, Hinxton, UK
| | | | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Archibald Worwui
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Ebenezer Foster-Nyarko
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Fatima Ceesay
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Catherine Bi Okoi
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia
| | - Keith P Klugman
- Rollins School Public Health, Emory University, Atlanta, USA
| | - Robert F Breiman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
| | | | - Richard Adegbola
- Immunisation and Global Health Consulting, RAMBICON, Lagos, Nigeria
| | - Martin Antonio
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia.,Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, UK
| | - William P Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, 677 Huntington Ave, Boston, MA 02115, USA
| | - Brenda A Kwambana-Adams
- WHO Regional Reference Laboratory (RRL), West Africa Strategy and Partnership, Medical Research Council Unit the Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Road, Fajara, The Gambia.,NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, UK
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14
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Valente C, Cruz AR, Henriques AO, Sá-Leão R. Intra-Species Interactions in Streptococcus pneumoniae Biofilms. Front Cell Infect Microbiol 2022; 11:803286. [PMID: 35071049 PMCID: PMC8767070 DOI: 10.3389/fcimb.2021.803286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/14/2021] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is a human pathogen responsible for high morbidity and mortality worldwide. Disease is incidental and is preceded by asymptomatic nasopharyngeal colonization in the form of biofilms. Simultaneous colonization by multiple pneumococcal strains is frequent but remains poorly characterized. Previous studies, using mostly laboratory strains, showed that pneumococcal strains can reciprocally affect each other's colonization ability. Here, we aimed at developing a strategy to investigate pneumococcal intra-species interactions occurring in biofilms. A 72h abiotic biofilm model mimicking long-term colonization was applied to study eight pneumococcal strains encompassing 6 capsular types and 7 multilocus sequence types. Strains were labeled with GFP or RFP, generating two fluorescent variants for each. Intra-species interactions were evaluated in dual-strain biofilms (1:1 ratio) using flow cytometry. Confocal microscopy was used to image representative biofilms. Twenty-eight dual-strain combinations were tested. Interactions of commensalism, competition, amensalism and neutralism were identified. The outcome of an interaction was independent of the capsular and sequence type of the strains involved. Confocal imaging of biofilms confirmed the positive, negative and neutral effects that pneumococci can exert on each other. In conclusion, we developed an experimental approach that successfully discriminates pneumococcal strains growing in mixed biofilms, which enables the identification of intra-species interactions. Several types of interactions occur among pneumococci. These observations are a starting point to study the mechanisms underlying those interactions.
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Affiliation(s)
- Carina Valente
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana R Cruz
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Adriano O Henriques
- Laboratory of Microbial Development, Instituto de Tecnologia Química e Biológica António Xavier, Oeiras, Portugal
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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15
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Lourenço J, Daon Y, Gori A, Obolski U. Pneumococcal Competition Modulates Antibiotic Resistance in the Pre-Vaccination Era: A Modelling Study. Vaccines (Basel) 2021; 9:265. [PMID: 33809706 PMCID: PMC8002235 DOI: 10.3390/vaccines9030265] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 11/30/2022] Open
Abstract
The ongoing emergence of antibiotic resistant strains and high frequencies of antibiotic resistance of Streptococcus pneumoniae poses a major public health challenge. How and which ecological and evolutionary mechanisms maintain the coexistence of antibiotic resistant and susceptible strains remains largely an open question. We developed an individual-based, stochastic model expanding on a previous pneumococci modelling framework. We explore how between- and within-host mechanisms of competition can sustain observed levels of resistance to antibiotics in the pre-vaccination era. Our framework considers that within-host competition for co-colonization between resistant and susceptible strains can arise via pre-existing immunity (immunological competition) or intrinsic fitness differences due to resistance costs (ecological competition). We find that beyond stochasticity, population structure or movement, competition at the within-host level can explain observed resistance frequencies. We compare our simulation results to pneumococcal antibiotic resistance data in the European region using approximate Bayesian computation. Our results demonstrate that ecological competition for co-colonization can explain the variation in co-existence of resistant and susceptible pneumococci observed in the pre-vaccination era. Furthermore, we show that within-host pneumococcal competition can facilitate the maintenance of resistance in the pre-vaccination era. Accounting for these competition-related components of pneumococcal dynamics can improve our understanding of drivers for the emergence and maintenance of antibiotic resistance in pneumococci.
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Affiliation(s)
- José Lourenço
- Department of Zoology, University of Oxford, Oxford OX1 3SZ, UK
| | - Yair Daon
- School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel;
- Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Andrea Gori
- NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London WC1E 6BT, UK;
| | - Uri Obolski
- School of Public Health, Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel;
- Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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16
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Lower Density and Shorter Duration of Nasopharyngeal Carriage by Pneumococcal Serotype 1 (ST217) May Explain Its Increased Invasiveness over Other Serotypes. mBio 2020; 11:mBio.00814-20. [PMID: 33293378 PMCID: PMC7733939 DOI: 10.1128/mbio.00814-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pneumoniae is a frequent colonizer of the human nasopharynx and a major cause of life-threating invasive infections such as pneumonia, meningitis and sepsis. Over 1 million people die every year due to invasive pneumococcal disease (IPD), mainly in developing countries. Serotype 1 is a common cause of IPD; however, unlike other serotypes, it is rarely found in the carrier state in the nasopharynx, which is often considered a prerequisite for disease. The aim of this study was to understand this dichotomy. We used murine models of carriage and IPD to characterize the pathogenesis of African serotype 1 (sequence type 217) pneumococcal strains obtained from the Queen Elizabeth Central Hospital in Blantyre, Malawi. We found that ST217 pneumococcal strains were highly virulent in a mouse model of invasive pneumonia, but in contrast to the generally accepted assumption, can also successfully establish nasopharyngeal carriage. Interestingly, we found that cocolonizing serotypes may proliferate in the presence of serotype 1, suggesting that acquisition of serotype 1 carriage could increase the risk of developing IPD by other serotypes. RNA sequencing analysis confirmed that key virulence genes associated with inflammation and tissue invasiveness were upregulated in serotype 1. These data reveal important new insights into serotype 1 pathogenesis, with implications for carriage potential and risk of invasive disease through interactions with other cocolonizing serotypes, an often-overlooked factor in transmission and disease progression.IMPORTANCE The pneumococcus causes serious diseases such as pneumonia, sepsis, and meningitis and is a major cause of morbidity and mortality worldwide. Serotype 1 accounts for the majority of invasive pneumococcal disease cases in sub-Saharan Africa but is rarely found during nasopharyngeal carriage. Understanding the mechanisms leading to nasopharyngeal carriage and invasive disease by this serotype can help reduce its burden on health care systems worldwide. In this study, we also uncovered the potential impact of serotype 1 on disease progression of other coinfecting serotypes, which can have important implications for vaccine efficacy. Understanding the interactions between different serotypes during nasopharyngeal carriage may lead to improved intervention methods and therapies to reduce pneumococcal invasive disease levels.
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17
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Manenzhe RI, Dube FS, Wright M, Lennard K, Mounaud S, Lo SW, Zar HJ, Nierman WC, Nicol MP, Moodley C. Characterization of Pneumococcal Colonization Dynamics and Antimicrobial Resistance Using Shotgun Metagenomic Sequencing in Intensively Sampled South African Infants. Front Public Health 2020; 8:543898. [PMID: 33072693 PMCID: PMC7536305 DOI: 10.3389/fpubh.2020.543898] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 08/17/2020] [Indexed: 11/13/2022] Open
Abstract
Background: There remains a significant proportion of deaths due to pneumococcal pneumonia in infants from low- and middle-income countries despite the marginal global declines recorded in the past decade. Monitoring changes in pneumococcal carriage is key to understanding vaccination-induced shifts in the ecology of carriage, patterns of antimicrobial resistance, and impact on health. We longitudinally investigated pneumococcal carriage dynamics in PCV-13 vaccinated infants by collecting nasopharyngeal (NP) samples at 2-weekly intervals from birth through the first year of life from 137 infants. As a proof of concept, 196 NP samples were retrieved from a subset of 23 infants to explore strain-level pneumococcal colonization patterns and associated antimicrobial-resistance determinants. These were selected on the basis of changes in serotype and antibiogram over time. NP samples underwent short-term enrichment for streptococci prior to total nucleic acid extraction and whole metagenome shotgun sequencing (WMGS). Reads were assembled and aligned to pneumococcal reference genomes for the extraction of pneumococcal and non-pneumococcal bacterial reads. Pneumococcal contigs were aligned to the Antibiotic Resistance Gene-ANNOTation database of acquired AMR genes. In silico pneumococcal capsular and multilocus sequence typing were performed. Results: Of the 196 samples sequenced, 174 had corresponding positive cultures for pneumococci, of which, 152 were assigned an in silico serotype. Metagenomic sequencing detected a single pneumococcal serotype in 85% (129/152), and co-colonization in 15% (23/152) of the samples. Twenty-two different pneumococcal serotypes were identified, with 15B/15C and 16F being the most common non-PCV13 serotypes, while 23F and 19A were the most common PCV13 serotypes. Twenty-six different sequence types (STs), including four novel STs were identified in silico. Mutations in the folA and folP genes, associated with cotrimoxazole resistance, were detected in 89% (87/98) of cotrimoxazole-non-susceptible pneumococci, as well as in the pbp1a and pbp2x genes, in penicillin non-susceptible ST705215B/15C isolates. Conclusions: Metagenomic sequencing of NP samples is a valuable culture-independent technique for a detailed evaluation of the pneumococcal component and resistome of the NP microbiome. This method allowed for the detection of novel STs, as well as co-colonization, with a predominance of non-PCV13 serotypes in this cohort. Forty-eight resistance genes, as well as mutations associated with resistance were detected, but the correlation with phenotypic non-susceptibility was lower than expected.
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Affiliation(s)
- Rendani I Manenzhe
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Felix S Dube
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Cape Town, South Africa
| | | | - Katie Lennard
- Division of Computational Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | - Stephanie W Lo
- Parasites and Microbes Program, The Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Heather J Zar
- Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and South African - Medical Research Council Unit on Child & Adolescent Health, University of Cape Town, Cape Town, South Africa
| | | | - Mark P Nicol
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Division of Infection and Immunity, University of Western Australia, Perth, WA, Australia
| | - Clinton Moodley
- Division of Medical Microbiology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
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18
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Chaguza C, Senghore M, Bojang E, Gladstone RA, Lo SW, Tientcheu PE, Bancroft RE, Worwui A, Foster-Nyarko E, Ceesay F, Okoi C, McGee L, Klugman KP, Breiman RF, Barer MR, Adegbola RA, Antonio M, Bentley SD, Kwambana-Adams BA. Within-host microevolution of Streptococcus pneumoniae is rapid and adaptive during natural colonisation. Nat Commun 2020; 11:3442. [PMID: 32651390 PMCID: PMC7351774 DOI: 10.1038/s41467-020-17327-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 06/25/2020] [Indexed: 02/08/2023] Open
Abstract
Genomic evolution, transmission and pathogenesis of Streptococcus pneumoniae, an opportunistic human-adapted pathogen, is driven principally by nasopharyngeal carriage. However, little is known about genomic changes during natural colonisation. Here, we use whole-genome sequencing to investigate within-host microevolution of naturally carried pneumococci in ninety-eight infants intensively sampled sequentially from birth until twelve months in a high-carriage African setting. We show that neutral evolution and nucleotide substitution rates up to forty-fold faster than observed over longer timescales in S. pneumoniae and other bacteria drives high within-host pneumococcal genetic diversity. Highly divergent co-existing strain variants emerge during colonisation episodes through real-time intra-host homologous recombination while the rest are co-transmitted or acquired independently during multiple colonisation episodes. Genic and intergenic parallel evolution occur particularly in antibiotic resistance, immune evasion and epithelial adhesion genes. Our findings suggest that within-host microevolution is rapid and adaptive during natural colonisation.
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Affiliation(s)
- Chrispin Chaguza
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK.
- Darwin College, University of Cambridge, Silver Street, Cambridge, UK.
| | - Madikay Senghore
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Ebrima Bojang
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Rebecca A Gladstone
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Stephanie W Lo
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Peggy-Estelle Tientcheu
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Rowan E Bancroft
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Archibald Worwui
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Ebenezer Foster-Nyarko
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Fatima Ceesay
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Catherine Okoi
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, USA
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, USA
| | | | - Michael R Barer
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Richard A Adegbola
- RAMBICON Immunisation & Global Health Consulting, 6A Platinum Close, Lekki, Lagos State, Nigeria
| | - Martin Antonio
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Stephen D Bentley
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK.
- Department of Pathology, University of Cambridge, Cambridge, UK.
| | - Brenda A Kwambana-Adams
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia.
- NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, UK.
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19
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Smith EL, Wheeler I, Adler H, Ferreira DM, Sá-Leão R, Abdullahi O, Adetifa I, Becker-Dreps S, Esposito S, Farida H, Kandasamy R, Mackenzie GA, Nuorti JP, Nzenze S, Madhi SA, Ortega O, Roca A, Safari D, Schaumburg F, Usuf E, Sanders EAM, Grant LR, Hammitt LL, O'Brien KL, Gounder P, Bruden DJT, Stanton MC, Rylance J. Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: A systematic review of prevalence and individual participant data meta-analysis of risk factors. J Infect 2020; 81:540-548. [PMID: 32562794 PMCID: PMC7532703 DOI: 10.1016/j.jinf.2020.06.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 06/10/2020] [Accepted: 06/13/2020] [Indexed: 12/11/2022]
Abstract
Systematic review and meta-analysis of 18 studies and more than 6000 participants. Adults over the age of 60 had a pooled prevalence of pneumococcal carriage of 9%. Risk factors: contact with children, smoking and residing in a nursing home.
Background Colonisation with Streptococcus pneumoniae can lead to invasive pneumococcal disease and pneumonia. Pneumococcal acquisition and prevalence of colonisation are high in children. In older adults, a population susceptible to pneumococcal disease, colonisation prevalence is reported to be lower, but studies are heterogeneous. Methods This is a systematic review and meta-analysis of prevalence of, and risk factors for, pneumococcal colonisation in adults ≥ 60 years of age (PROSPERO #42016036891). We identified peer-reviewed studies reporting the prevalence of S. pneumoniae colonisation using MEDLINE and EMBASE (until April 2016), excluding studies of acute disease. Participant-level data on risk factors were sought from each study. Findings Of 2202 studies screened, 29 were analysable: 18 provided participant-level data (representing 6290 participants). Prevalence of detected pneumococcal colonisation was 0–39% by conventional culture methods and 3–23% by molecular methods. In a multivariate analysis, colonisation was higher in persons from nursing facilities compared with the community (odds ratio (OR) 2•30, 95% CI 1•26–4•21 and OR 7•72, 95% CI 1•15–51•85, respectively), in those who were currently smoking (OR 1•69, 95% CI 1•12–2•53) or those who had regular contact with children (OR 1•93, 95%CI 1•27–2•93). Persons living in urban areas had significantly lower carriage prevalence (OR 0•43, 95%CI 0•27–0•70). Interpretation Overall prevalence of pneumococcal colonisation in older adults was higher than expected but varied by risk factors. Future studies should further explore risk factors for colonisation, to highlight targets for focussed intervention such as pneumococcal vaccination of high-risk groups. Funding No funding was required.
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Affiliation(s)
- Emma L Smith
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - India Wheeler
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hugh Adler
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Daniela M Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Raquel Sá-Leão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Osman Abdullahi
- Department of Public Health, School of Health and Human Sciences, Pwani University, Kilifi, Kenya
| | - Ifedayo Adetifa
- Epidemiology and Demography Department, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya; Department of Infectious Diseases Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, WC1E 7HT, London, United Kingdom; Department of Paediatrics and Child Health, College of Medicine, University of Lagos, Idi-Araba, Lagos, Nigeria
| | - Sylvia Becker-Dreps
- Departments of Family Medicine and Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Perugia, Italy
| | - Helmia Farida
- Faculty of Medicine, Diponegoro University, Semarang, Indonesia
| | - Rama Kandasamy
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford OX3 7LE, United Kingdom; NIHR Oxford Biomedical Research Centre, Oxford OX3 7LE, United Kingdom
| | - Grant A Mackenzie
- Medical Research Council The Gambia Unit at LSHTM, Banjul, The Gambia; Faculty of Infectious and Tropical Diseases, The London School of Hygiene & Tropical Medicine, United Kingdom; Infection and Immunity Theme, Murdoch Children's Research Institute, Melbourne, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - J Pekka Nuorti
- Health Sciences Unit, Faculty of Social Sciences, Tampere University, Finland; Department of Health Security, National Institute for Health and Welfare (THL), Helsinki, Finland
| | - Susan Nzenze
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
| | - Shabir A Madhi
- Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa
| | - Omar Ortega
- Gastrointestinal Physiology Laboratory, Department of Surgery, Hospital de Mataró, Universitat Autónoma de Barcelona, Mataró, Spain; Centro de Investigación Biomédica en Red de enfermedades hepáticas y digestivas (CIBERehd), Instituto de Salud Carlos III, Barcelona, Spain
| | - Anna Roca
- Medical Research Council The Gambia Unit at LSHTM, Banjul, The Gambia
| | - Dodi Safari
- Eijkman Institute for Molecular Biology, Jl. Diponegoro no. 69 Jakarta, Indonesia
| | - Frieder Schaumburg
- Institute of Medical Microbiology, University Hospital Muenster, Muenster, Germany
| | - Effua Usuf
- Medical Research Council The Gambia Unit at LSHTM, Banjul, The Gambia
| | - Elisabeth A M Sanders
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, the Netherlands
| | - Lindsay R Grant
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Laura L Hammitt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Katherine L O'Brien
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Prabhu Gounder
- Arctic Investigations Program, Division of Preparedness and Emerging Infections, Center for Disease Control and Prevention, Anchorage, Alaska
| | - Dana J T Bruden
- Arctic Investigations Program, Division of Preparedness and Emerging Infections, Center for Disease Control and Prevention, Anchorage, Alaska
| | | | - Jamie Rylance
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
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20
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Flasche S, Lipsitch M, Ojal J, Pinsent A. Estimating the contribution of different age strata to vaccine serotype pneumococcal transmission in the pre vaccine era: a modelling study. BMC Med 2020; 18:129. [PMID: 32517683 PMCID: PMC7285529 DOI: 10.1186/s12916-020-01601-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Herd protection through interruption of transmission has contributed greatly to the impact of pneumococcal conjugate vaccines (PCVs) and may enable the use of cost-saving reduced dose schedules. To aid PCV age targeting to achieve herd protection, we estimated which population age groups contribute most to vaccine serotype (VT) pneumococcal transmission. METHODS We used transmission dynamic models to mirror pre-PCV epidemiology in England and Wales, Finland, Kilifi in Kenya and Nha Trang in Vietnam where data on carriage prevalence in infants, pre-school and school-aged children and adults as well as social contact patterns was available. We used Markov Chain Monte Carlo methods to fit the models and then extracted the per capita and population-based contribution of different age groups to VT transmission. RESULTS We estimated that in all settings, < 1-year-old infants cause very frequent secondary vaccine type pneumococcal infections per capita. However, 1-5-year-old children have the much higher contribution to the force of infection at 51% (28, 73), 40% (27, 59), 37% (28, 48) and 67% (41, 86) of the total infection pressure in E&W, Finland, Kilifi and Nha Trang, respectively. Unlike the other settings, school-aged children in Kilifi were the dominant source for VT infections with 42% (29, 54) of all infections caused. Similarly, we estimated that the main source of VT infections in infants are pre-school children and that in Kilifi 39% (28, 51) of VT infant infections stem from school-aged children whereas this was below 15% in the other settings. CONCLUSION Vaccine protection of pre-school children is key for PCV herd immunity. However, in high transmission settings, school-aged children may substantially contribute to transmission and likely have waned much of their PCV protection under currently recommended schedules.
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Affiliation(s)
- Stefan Flasche
- Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK.
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology and Department of Immunology and Infectious Diseases, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, USA
| | - John Ojal
- Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK
| | - Amy Pinsent
- Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, Keppel Street, London, UK
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21
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Antibiotic Resistance Is Associated with Integrative and Conjugative Elements and Genomic Islands in Naturally Circulating Streptococcus pneumoniae Isolates from Adults in Liverpool, UK. Genes (Basel) 2020; 11:genes11060625. [PMID: 32517221 PMCID: PMC7348760 DOI: 10.3390/genes11060625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 11/23/2022] Open
Abstract
Pneumonia is the sixth largest cause of death in the UK. It is usually caused by Streptococcus pneumoniae, which healthy individuals can carry in their nose without symptoms of disease. Antimicrobial resistance further increases mortality and morbidity associated with pneumococcal infection, although few studies have analysed resistance in naturally circulating pneumococcal isolates in adult populations. Here, we report on the resistome and associated mobile genetic elements within circulating pneumococcus isolated from adult volunteers enrolled in the experimental human pneumococcal colonisation (EHPC) research program at the Liverpool School of Tropical Medicine, UK. Pneumococcal isolates collected from 30 healthy asymptomatic adults who had volunteered to take part in clinical research were screened for antibiotic susceptibility to erythromycin and tetracycline, and whole-genome sequenced. The genetic context of resistance to one or both antibiotics in four isolates was characterised bioinformatically, and any association of the resistance genes with mobile genetic elements was determined. Tetracycline and macrolide resistance genes [tet(M), erm(B), mef(A), msr(D)] were detected on known Tn916-like integrative and conjugative elements, namely Tn6002 and Tn2010, and tet(32) was found for the first time in S. pneumoniae located on a novel 50 kb genomic island. The widespread use of pneumococcal conjugate vaccines impacts on serotype prevalence and transmission within the community. It is therefore important to continue to monitor antimicrobial resistance (AMR) genes present in both vaccine types and non-vaccine types in response to contemporary antimicrobial therapies and characterise the genetic context of acquired resistance genes to continually optimise antibiotic therapies.
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22
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Localized Hypermutation is the Major Driver of Meningococcal Genetic Variability during Persistent Asymptomatic Carriage. mBio 2020; 11:mBio.03068-19. [PMID: 32209693 PMCID: PMC7157529 DOI: 10.1128/mbio.03068-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Host persistence of bacteria is facilitated by mutational and recombinatorial processes that counteract loss of genetic variation during transmission and selection from evolving host responses. Genetic variation was investigated during persistent asymptomatic carriage of Neisseria meningitidis Interrogation of whole-genome sequences for paired isolates from 25 carriers showed that de novo mutations were infrequent, while horizontal gene transfer occurred in 16% of carriers. Examination of multiple isolates per time point enabled separation of sporadic and transient allelic variation from directional variation. A comprehensive comparative analysis of directional allelic variation with hypermutation of simple sequence repeats and hyperrecombination of class 1 type IV pilus genes detected an average of seven events per carrier and 2:1 bias for changes due to localized hypermutation. Directional genetic variation was focused on the outer membrane with 69% of events occurring in genes encoding enzymatic modifiers of surface structures or outer membrane proteins. Multiple carriers exhibited directional and opposed switching of allelic variants of the surface-located Opa proteins that enables continuous expression of these adhesins alongside antigenic variation. A trend for switching from PilC1 to PilC2 expression was detected, indicating selection for specific alterations in the activities of the type IV pilus, whereas phase variation of restriction modification (RM) systems, as well as associated phasevarions, was infrequent. We conclude that asymptomatic meningococcal carriage on mucosal surfaces is facilitated by frequent localized hypermutation and horizontal gene transfer affecting genes encoding surface modifiers such that optimization of adhesive functions occurs alongside escape of immune responses by antigenic variation.IMPORTANCE Many bacterial pathogens coexist with host organisms, rarely causing disease while adapting to host responses. Neisseria meningitidis, a major cause of meningitis and septicemia, is a frequent persistent colonizer of asymptomatic teenagers/young adults. To assess how genetic variation contributes to host persistence, whole-genome sequencing and hypermutable sequence analyses were performed on multiple isolates obtained from students naturally colonized with meningococci. High frequencies of gene transfer were observed, occurring in 16% of carriers and affecting 51% of all nonhypermutable variable genes. Comparative analyses showed that hypermutable sequences were the major mechanism of variation, causing 2-fold more changes in gene function than other mechanisms. Genetic variation was focused on genes affecting the outer membrane, with directional changes in proteins responsible for bacterial adhesion to host surfaces. This comprehensive examination of genetic plasticity in individual hosts provides a significant new platform for rationale design of approaches to prevent the spread of this pathogen.
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23
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Mulberry N, Rutherford A, Colijn C. Systematic comparison of coexistence in models of drug-sensitive and drug-resistant pathogen strains. Theor Popul Biol 2019; 133:150-158. [PMID: 31887315 DOI: 10.1016/j.tpb.2019.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
A number of mathematical models have recently been proposed to explain empirical trends of pathogen diversity. In particular, long-term coexistence of both drug-sensitive and drug-resistant variants of a single pathogen is something of a mystery, given that simple models of pathogens competing for the same ecological niche predict competitive exclusion, and more complex models admitting coexistence require assumptions that may not be justified. Coinfection is among the candidate mechanisms to generate coexistence, as it occurs in many pathogens and provides the opportunity for strains to interact directly. Recently, coinfection and competitive release have been described as creating a form of negative frequency-dependent selection that promotes coexistence, and a range of models containing coinfection have been proposed as having generic stable coexistence of multiple strains. This abundance of new models presents the challenge of comparison and interpretation. To this end, we describe a dimensionless quantity that can be used to compare the amount of coexistence generated by different models. We focus on models that include coinfection, although this framework could be generalized to a larger class of structured models.
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24
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Davies NG, Flasche S, Jit M, Atkins KE. Within-host dynamics shape antibiotic resistance in commensal bacteria. Nat Ecol Evol 2019; 3:440-449. [PMID: 30742105 PMCID: PMC6420107 DOI: 10.1038/s41559-018-0786-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022]
Abstract
The spread of antibiotic resistance, a major threat to human health, is poorly understood. Simple population-level models of bacterial transmission predict that above a certain rate of antibiotic consumption in a population, resistant bacteria should completely eliminate non-resistant strains, while below this threshold they should be unable to persist at all. This prediction stands at odds with empirical evidence showing that resistant and non-resistant strains coexist stably over a wide range of antibiotic consumption rates. Not knowing what drives this long-term coexistence is a barrier to developing evidence-based strategies for managing the spread of resistance. Here, we argue that competition between resistant and sensitive pathogens within individual hosts gives resistant pathogens a relative fitness benefit when they are rare, promoting coexistence between strains at the population level. To test this hypothesis, we embed mechanistically explicit within-host dynamics in a structurally neutral pathogen transmission model. Doing so allows us to reproduce patterns of resistance observed in the opportunistic pathogens Escherichia coli and Streptococcus pneumoniae across European countries and to identify factors that may shape resistance evolution in bacteria by modulating the intensity and outcomes of within-host competition.
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Affiliation(s)
- Nicholas G Davies
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK.
- Department for Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
| | - Stefan Flasche
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Department for Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Department for Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
- Modelling and Economics Unit, Public Health England, London, UK
| | - Katherine E Atkins
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Department for Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Global Health, Usher Institute of Population Health Sciences and Informatics, Edinburgh Medical School, The University of Edinburgh, Edinburgh, UK
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25
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Shen P, Lees JA, Bee GCW, Brown SP, Weiser JN. Pneumococcal quorum sensing drives an asymmetric owner-intruder competitive strategy during carriage via the competence regulon. Nat Microbiol 2018; 4:198-208. [PMID: 30546100 DOI: 10.1038/s41564-018-0314-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/30/2018] [Indexed: 11/09/2022]
Abstract
Competition among microorganisms is a key determinant of successful host colonization and persistence. For Streptococcus pneumoniae, lower than predicted rates of co-colonizing strains suggest a competitive advantage for resident bacteria over newcomers. In light of evolutionary theory, we hypothesized that S. pneumoniae use owner-intruder asymmetries to settle contests, leading to the disproportionate success of the initial resident 'owner', regardless of the genetic identity of the 'intruder'. We investigated the determinants of within-host competitive success utilizing S. pneumoniae colonization of the upper respiratory tract of infant mice. Within 6 h, colonization by the resident inhibited colonization by an isogenic challenger. The competitive advantage of the resident was dependent on quorum sensing via the competence (Com) regulon and downstream choline binding protein D (CbpD) and on the competence-induced bacteriocins A and B (CibAB) implicated in fratricide. CbpD and CibAB are highly conserved across pneumococcal lineages, indicating evolutionary advantages for asymmetric competitive strategies within the species. Mathematical modelling supported a significant role for quorum sensing via the Com regulon in competition, even for strains with different competitive advantages. Our study suggests that asymmetric owner-intruder competitive strategies do not require complex cognition and are used by a major human pathogen to determine 'ownership' of human hosts.
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Affiliation(s)
- Pamela Shen
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - John A Lees
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Gavyn Chern Wei Bee
- Department of Microbiology, New York University School of Medicine, New York, NY, USA
| | - Sam P Brown
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jeffrey N Weiser
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.
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Birindwa AM, Emgård M, Nordén R, Samuelsson E, Geravandi S, Gonzales-Siles L, Muhigirwa B, Kashosi T, Munguakonkwa E, Manegabe JT, Cibicabene D, Morisho L, Mwambanyi B, Mirindi J, Kabeza N, Lindh M, Andersson R, Skovbjerg S. High rate of antibiotic resistance among pneumococci carried by healthy children in the eastern part of the Democratic Republic of the Congo. BMC Pediatr 2018; 18:361. [PMID: 30453916 PMCID: PMC6241069 DOI: 10.1186/s12887-018-1332-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/31/2018] [Indexed: 12/02/2022] Open
Abstract
Background Pneumococcal conjugate vaccines have been introduced in the infant immunisation programmes in many countries to reduce the rate of fatal pneumococcal infections. In the Democratic Republic of the Congo (DR Congo) a 13-valent vaccine (PCV13) was introduced in 2013. Data on the burden of circulating pneumococci among children after this introduction are lacking. In this study, we aimed to determine the risk factors related to pneumococcal carriage in healthy Congolese children after the vaccine introduction and to assess the antibiotic resistance rates and serotype distribution among the isolated pneumococci. Methods In 2014 and 2015, 794 healthy children aged one to 60 months attending health centres in the eastern part of DR Congo for immunisation or growth monitoring were included in the study. Data on socio-demographic and medical factors were collected by interviews with the children’s caregivers. Nasopharyngeal swabs were obtained from all the children for bacterial culture, and isolated pneumococci were further tested for antimicrobial resistance using disc diffusion tests and, when indicated, minimal inhibitory concentration (MIC) determination, and for serotype/serogroup by molecular testing. Results The pneumococcal detection rate was 21%, being higher among children who had not received PCV13 vaccination, lived in rural areas, had an enclosed kitchen, were malnourished or presented with fever (p value < 0.05). The predominant serotypes were 19F, 11, 6A/B/C/D and 10A. More than 50% of the pneumococcal isolates belonged to a serotype/serogroup not included in PCV13. Eighty per cent of the isolates were not susceptible to benzylpenicillin and non-susceptibility to ampicillin and ceftriaxone was also high (42 and 37% respectively). Almost all the isolates (94%) were resistant to trimethoprim-sulphamethoxazole, while 43% of the strains were resistant to ≥3 antibiotics. Conclusions Our study shows alarmingly high levels of reduced susceptibility to commonly used antibiotics in pneumococci carried by healthy Congolese children. This highlights the importance of local antibiotic resistance surveillance and indicates the needs for the more appropriate use of antibiotics in the area. The results further indicate that improved living conditions are needed to reduce the pneumococcal burden, in addition to PCV13 vaccination. Electronic supplementary material The online version of this article (10.1186/s12887-018-1332-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Archippe M Birindwa
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden. .,Panzi Hospital, Bukavu, Democratic Republic of the Congo. .,Université Evangélique en Afrique, Bukavu, Democratic Republic of the Congo. .,Hôpital Général de Référence de Panzi, BP: 266, Bukavu, DR, Congo.
| | - Matilda Emgård
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Rickard Nordén
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Ebba Samuelsson
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Shadi Geravandi
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Lucia Gonzales-Siles
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | | | - Théophile Kashosi
- Université Evangélique en Afrique, Bukavu, Democratic Republic of the Congo
| | | | | | | | | | | | | | - Nadine Kabeza
- Panzi Hospital, Bukavu, Democratic Republic of the Congo
| | - Magnus Lindh
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Rune Andersson
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,CARe - Center for Antibiotic Resistance Research, Gothenburg University, Gothenburg, Sweden
| | - Susann Skovbjerg
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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Heinsbroek E, Tafatatha T, Phiri A, Swarthout TD, Alaerts M, Crampin AC, Chisambo C, Mwiba O, Read JM, French N. Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination. Vaccine 2018; 36:7369-7376. [PMID: 30352744 PMCID: PMC6238076 DOI: 10.1016/j.vaccine.2018.10.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 08/24/2018] [Accepted: 10/05/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Thirteen-valent pneumococcal conjugate vaccine (PCV13) was introduced in Malawi in November 2011 and is offered to infants at 6, 10 and 14 weeks of age as part of routine immunisation. PCV13 is expected to reduce vaccine type (VT) nasopharyngeal carriage, leading to reduced transmission and herd protection. METHODS We compared pneumococcal carriage in rural Karonga District, Malawi, pre-vaccine in 2009-2011 and post-vaccine in 2014 using a combination of cross-sectional and longitudinal analyses. Nasopharyngeal swabs were collected from a cohort of mother-infant pairs and household members <16 years. Pneumococci from 2009 to 2011 were serogrouped using latex agglutination and serotyped by Quellung reaction. In 2014, latex agglutination was used for both steps. Carriage prevalence ratios using prevalence data from before and after vaccine introduction were calculated by log-binomial regression, adjusted for age, seasonality and household composition. Participating infants in 2014 received PCV13 as part of routine immunisation. RESULTS VT carriage prior to PCV-13 introduction was 11.4%, 45.1%, 28.2%, 21.2% and 6.6% for 6-week old infants, 18-week old infants, children 1-4 years, children 5-15 years and mothers, respectively. After vaccine introduction, VT carriage decreased among vaccinated 18-week old infants (adjusted prevalence ratio 0.24 (95%CI 0.08-0.75)), vaccinated children 1-4 years (0.54 (0.33-0.88)), unvaccinated children 5-15 years (0.37 (0.17-0.78)) and mothers (0.34 (0.15-0.79)). No decrease in VT carriage was observed for 6-week old infants too young to be vaccinated (1.07 (0.38-3.02)) and PCV-13 ineligible children 1-4 years (0.84 (0.53-1.33)). Non-VT carriage increased only among vaccinated children 1-4 years (1.58 (1.21-2.06)). CONCLUSIONS There is evidence of reduced VT pneumococcal carriage three years after vaccine introduction in this rural Malawian population with good vaccine coverage using a 3 + 0 schedule. However carriage was sustained among 6-week-old infants and PCV13 ineligible 1-4 year olds, and there was some indication of serotype replacement in vaccinated 1-4 year olds.
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Affiliation(s)
- Ellen Heinsbroek
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | | | - Amos Phiri
- Karonga Prevention Study, Chilumba, Malawi
| | - Todd D Swarthout
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi; Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Maaike Alaerts
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Amelia C Crampin
- Karonga Prevention Study, Chilumba, Malawi; London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Jonathan M Read
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Centre for Health Informatics Computing and Statistics, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Neil French
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi.
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Invasive Disease Caused Simultaneously by Dual Serotypes of Streptococcus pneumoniae. J Clin Microbiol 2017; 56:JCM.01149-17. [PMID: 29118167 DOI: 10.1128/jcm.01149-17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/28/2017] [Indexed: 11/20/2022] Open
Abstract
There are at least 98 known pneumococcal serotypes. Invasive pneumococcal disease (IPD) is usually caused by a single serotype, and dual-serotype IPD is rare. To assess factors associated with dual-serotype IPD, patient information obtained through laboratory-based surveillance for IPD from 2005 through 2014 in South Africa was reviewed. Genomes of isolate pairs from coinfected individuals were sequenced to determine their molecular characteristics. For 30 (91%) of 33 patients with dual serotypes, one or both isolates were a pneumococcal conjugate vaccine (PCV13) serotype. Dual-serotype IPD was associated with children <5 years of age (adjusted odds ratio [aOR], 4.7; 95% confidence interval [95% CI], 1.8 to 11.7), underlying illness (other than HIV) (aOR, 2.8; 95% CI, 1.1 to 6.6) and death (aOR, 2.5; 95% CI, 1.08 to 6.09). For each coinfecting pair, isolates were genotypically unrelated, and their genotypes were common among isolates of the same serotype in South Africa. Of 701 accessory genes identified among dual-serotype IPD isolates, four were common between isolate pairs. Coinfecting isolate pairs had different genotypic backgrounds. The association of dual serotypes with death warrants increased awareness of IPD coinfection caused by two or more serotypes.
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Abstract
Colonization of the human nasopharynx by pneumococcus is extremely common and is both the primary reservoir for transmission and a prerequisite for disease. Current vaccines targeting the polysaccharide capsule effectively prevent colonization, conferring herd protection within vaccinated communities. However, these vaccines cover only a subset of all circulating pneumococcal strains, and serotype replacement has been observed. Given the success of pneumococcal conjugate vaccine (PCV) in preventing colonization in unvaccinated adults within vaccinated communities, reducing nasopharyngeal colonization has become an outcome of interest for novel vaccines. Here, we discuss the immunological mechanisms that control nasopharyngeal colonization, with an emphasis on findings from human studies. Increased understanding of these immunological mechanisms is required to identify correlates of protection against colonization that will facilitate the early testing and design of novel vaccines.
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Affiliation(s)
- Simon P. Jochems
- Department of Clinicial Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail: (SPJ); (DMF)
| | - Jeffrey N. Weiser
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Richard Malley
- Division of Infectious Diseases, Boston Children′s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniela M. Ferreira
- Department of Clinicial Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail: (SPJ); (DMF)
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30
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The nasopharyngeal microbiome. Emerg Top Life Sci 2017; 1:297-312. [PMID: 33525776 DOI: 10.1042/etls20170041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/19/2017] [Accepted: 10/20/2017] [Indexed: 02/07/2023]
Abstract
Human microbiomes have received increasing attention over the last 10 years, leading to a pervasiveness of hypotheses relating dysbiosis to health and disease. The respiratory tract has received much less attention in this respect than that of, for example, the human gut. Nevertheless, progress has been made in elucidating the immunological, ecological and environmental drivers that govern these microbial consortia and the potential consequences of aberrant microbiomes. In this review, we consider the microbiome of the nasopharynx, a specific niche of the upper respiratory tract. The nasopharynx is an important site, anatomically with respect to its gateway position between upper and lower airways, and for pathogenic bacterial colonisation. The dynamics of the latter are important for long-term respiratory morbidity, acute infections of both invasive and non-invasive disease and associations with chronic airway disease exacerbations. Here, we review the development of the nasopharyngeal (NP) microbiome over the life course, examining it from the early establishment of resilient profiles in neonates through to perturbations associated with pneumonia risk in the elderly. We focus specifically on the commensal, opportunistically pathogenic members of the NP microbiome that includes Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae and Moraxella catarrhalis. In addition, we consider the role of relatively harmless genera such as Dolosigranulum and Corynebacterium. Understanding that the NP microbiome plays such a key, beneficial role in maintaining equilibrium of commensal species, prevention of pathogen outgrowth and host immunity enables future research to be directed appropriately.
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31
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Pneumococcal conjugate vaccine 13 delivered as one primary and one booster dose (1 + 1) compared with two primary doses and a booster (2 + 1) in UK infants: a multicentre, parallel group randomised controlled trial. THE LANCET. INFECTIOUS DISEASES 2017; 18:171-179. [PMID: 29174323 PMCID: PMC5805912 DOI: 10.1016/s1473-3099(17)30654-0] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 12/29/2022]
Abstract
Background Infants in the UK were first offered a pneumococcal conjugate vaccine (PCV7) in 2006, given at 2 and 4 months of age and a booster dose at 13 months (2 + 1 schedule). A 13-valent vaccine (PCV13) replaced PCV7 in 2010. We aimed to compare the post-booster antibody response in UK infants given a reduced priming schedule of PCV13 (ie, a 1 + 1 schedule) versus the current 2 + 1 schedule and to assess the potential effect on population protection. Methods In this multicentre, parallel group, randomised controlled trial, we recuited infants due to receive their primary immunisations aged up to 13 weeks on first vaccinations by information booklets mailed out via the NHS Child Health Information Service and the UK National Health Application and Infrastructure Services. Eligible infants were randomly assigned (1:1) to receive PCV13 at 2, 4, and 12 months (2 + 1 schedule) or 3 and 12 months of age (1 + 1 schedule) delivered with other routine vaccinations. Randomisation was done by computer-generated permuted block randomisation, with a block size of six. Participants and clinical trial staff were not masked to treatment allocation. The primary endpoint was serotype-specific immunoglobulin G concentrations values (geometric mean concentrations [GMC] in μg/mL) measured in blood samples collected at 13 months of age. Analysis was by modified intention to treat with all individuals included by randomised group if they had a laboratory result. This trial is registered on the EudraCT clinical trial database, number 2015-000817-32, and ClinicalTrials.gov, number NCT02482636. Findings Between September, 2015, and June, 2016, 376 infants were assessed for eligibility. 81 infants were excluded for not meeting the inclusion criteria (n=50) or for other reasons (n=31). 213 eligible infants were enrolled and randomly allocated to group 1 (n=106; 2 + 1 schedule) or to group 2 (n=107; 1 + 1 schedule). In group 1, 91 serum samples were available for analysis 1 month after booster immunisation versus 86 in group 2. At month 13, post-booster, GMCs were equivalent between schedules for serotypes 3 (0·61 μg/mL in group 1 vs 0·62 μg/mL in group 2), 5 (1·74 μg/mL vs 2·11 μg/mL), 7F (3·98 μg/mL vs 3·36 μg/mL), 9V (2·34 μg/mL vs 2·50 μg/mL), and 19A (8·38 μg/mL vs 8·83 μg/mL). Infants given the 1 + 1 schedule had significantly greater immunogenicity post-booster than those given the 2 + 1 schedule for serotypes 1 (8·92 μg/mL vs 3·07 μg/mL), 4 (3·43 μg/mL vs 2·55 μg/mL), 14 (16·9 μg/mL vs 10·49 μg/mL), and 19F (14·76 μg/mL vs 11·12 μg/mL; adjusted p value range <0·001 to 0·047). The 2 + 1 schedule was superior for serotypes 6A, 6B, 18C and 23F (adjusted p value range <0·0001 to 0·017). In a predefined numerical subset of all of the infants recruited to the study (n=40 [20%]), functional serotype-specific antibody was similar between schedules. 26 serious adverse events were recorded in 21 (10%) infants across the study period; 18 (n=13) were in the 2 + 1 group and eight (n=8) in the 1 + 1 group. Only one serious adverse event, a high temperature and refusal to feed after the first vaccination visit in a child on the 2+1 schedule was considered related to vaccine. Interpretation Our findings show that for nine of the 13 serotypes in PCV13, post-booster responses in infants primed with a single dose are equivalent or superior to those seen following the standard UK 2 + 1 schedule. Introducing a 1 + 1 schedule in countries with a mature PCV programme and established herd immunity is likely to maintain population control of vaccine-type pneumococcal disease. Funding NIHR and the Bill & Melinda Gates Foundation.
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32
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Current challenges in the accurate identification of Streptococcus pneumoniae and its serogroups/serotypes in the vaccine era. J Microbiol Methods 2017; 141:48-54. [DOI: 10.1016/j.mimet.2017.07.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 07/30/2017] [Accepted: 07/31/2017] [Indexed: 11/21/2022]
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Michael Dunne W, Pouseele H, Monecke S, Ehricht R, van Belkum A. Epidemiology of transmissible diseases: Array hybridization and next generation sequencing as universal nucleic acid-mediated typing tools. INFECTION GENETICS AND EVOLUTION 2017; 63:332-345. [PMID: 28943408 DOI: 10.1016/j.meegid.2017.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 02/05/2023]
Abstract
The magnitude of interest in the epidemiology of transmissible human diseases is reflected in the vast number of tools and methods developed recently with the expressed purpose to characterize and track evolutionary changes that occur in agents of these diseases over time. Within the past decade a new suite of such tools has become available with the emergence of the so-called "omics" technologies. Among these, two are exponents of the ongoing genomic revolution. Firstly, high-density nucleic acid probe arrays have been proposed and developed using various chemical and physical approaches. Via hybridization-mediated detection of entire genes or genetic polymorphisms in such genes and intergenic regions these so called "DNA chips" have been successfully applied for distinguishing very closely related microbial species and strains. Second and even more phenomenal, next generation sequencing (NGS) has facilitated the assessment of the complete nucleotide sequence of entire microbial genomes. This technology currently provides the most detailed level of bacterial genotyping and hence allows for the resolution of microbial spread and short-term evolution in minute detail. We will here review the very recent history of these two technologies, sketch their usefulness in the elucidation of the spread and epidemiology of mostly hospital-acquired infections and discuss future developments.
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Affiliation(s)
- W Michael Dunne
- Data Analytics Unit, bioMerieux, 100 Rodolphe Street, Durham, NC 27712, USA.
| | - Hannes Pouseele
- Data Analytics Unit, bioMerieux, 100 Rodolphe Street, Durham, NC 27712, USA; Applied Maths NV, Keistraat 120, 9830 Sint-Martens-Latem, Belgium.
| | - Stefan Monecke
- Alere Technologies GmbH, Jena, Germany; InfectoGnostics Research Campus, Jena, Germany; Institute for Medical Microbiology and Hygiene, Technische Universität Dresden, Dresden, Germany
| | - Ralf Ehricht
- Alere Technologies GmbH, Jena, Germany; InfectoGnostics Research Campus, Jena, Germany.
| | - Alex van Belkum
- Data Analytics Unit, bioMérieux, 3, Route de Port Michaud, 38390 La Balme Les Grottes, France.
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Wright MS, McCorrison J, Gomez AM, Beck E, Harkins D, Shankar J, Mounaud S, Segubre-Mercado E, Mojica AMR, Bacay B, Nzenze SA, Kimaro SZM, Adrian P, Klugman KP, Lucero MG, Nelson KE, Madhi S, Sutton GG, Nierman WC, Losada L. Strain Level Streptococcus Colonization Patterns during the First Year of Life. Front Microbiol 2017; 8:1661. [PMID: 28932211 PMCID: PMC5592222 DOI: 10.3389/fmicb.2017.01661] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/16/2017] [Indexed: 01/20/2023] Open
Abstract
Pneumococcal pneumonia has decreased significantly since the implementation of the pneumococcal conjugate vaccine (PCV), nevertheless, in many developing countries pneumonia mortality in infants remains high. We have undertaken a study of the nasopharyngeal (NP) microbiome during the first year of life in infants from The Philippines and South Africa. The study entailed the determination of the Streptococcus sp. carriage using a lytA qPCR assay, whole metagenomic sequencing, and in silico serotyping of Streptococcus pneumoniae, as well as 16S rRNA amplicon based community profiling. The lytA carriage in both populations increased with infant age and lytA+ samples ranged from 24 to 85% of the samples at each sampling time point. We next developed informatic tools for determining Streptococcus community composition and pneumococcal serotype from metagenomic sequences derived from a subset of longitudinal lytA-positive Streptococcus enrichment cultures from The Philippines (n = 26 infants, 50% vaccinated) and South African (n = 7 infants, 100% vaccinated). NP samples from infants were passaged in enrichment media, and metagenomic DNA was purified and sequenced. In silico capsular serotyping of these 51 metagenomic assemblies assigned known serotypes in 28 samples, and the co-occurrence of serotypes in 5 samples. Eighteen samples were not typeable using known serotypes but did encode for capsule biosynthetic cluster genes similar to non-encapsulated reference sequences. In addition, we performed metagenomic assembly and 16S rRNA amplicon profiling to understand co-colonization dynamics of Streptococcus sp. and other NP genera, revealing the presence of multiple Streptococcus species as well as potential respiratory pathogens in healthy infants. A range of virulence and drug resistant elements were identified as circulating in the NP microbiomes of these infants. This study revealed the frequent co-occurrence of multiple S. pneumoniae strains along with Streptococcus sp. and other potential pathogens such as S. aureus in the NP microbiome of these infants. In addition, the in silico serotype analysis proved powerful in determining the serotypes in S. pneumoniae carriage, and may lead to developing better targeted vaccines to prevent invasive pneumococcal disease (IPD) in these countries. These findings suggest that NP colonization by S. pneumoniae during the first years of life is a dynamic process involving multiple serotypes and species.
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Affiliation(s)
| | | | | | - Erin Beck
- J. Craig Venter InstituteRockville, MD, United States
| | - Derek Harkins
- J. Craig Venter InstituteRockville, MD, United States
| | - Jyoti Shankar
- J. Craig Venter InstituteRockville, MD, United States
| | | | | | | | - Brian Bacay
- Research Institute of Tropical MedicineMuntinlupa City, Philippines
| | - Susan A Nzenze
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Sheila Z M Kimaro
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Peter Adrian
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Keith P Klugman
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
| | - Marilla G Lucero
- Research Institute of Tropical MedicineMuntinlupa City, Philippines
| | | | - Shabir Madhi
- Respiratory and Meningeal Pathogens Research UnitSoweto, South Africa
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Chaguza C, Cornick JE, Andam CP, Gladstone RA, Alaerts M, Musicha P, Peno C, Bar-Zeev N, Kamng'ona AW, Kiran AM, Msefula CL, McGee L, Breiman RF, Kadioglu A, French N, Heyderman RS, Hanage WP, Bentley SD, Everett DB. Population genetic structure, antibiotic resistance, capsule switching and evolution of invasive pneumococci before conjugate vaccination in Malawi. Vaccine 2017; 35:4594-4602. [PMID: 28711389 PMCID: PMC5571440 DOI: 10.1016/j.vaccine.2017.07.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 06/23/2017] [Accepted: 07/03/2017] [Indexed: 01/15/2023]
Abstract
INTRODUCTION Pneumococcal infections cause a high death toll in Sub Saharan Africa (SSA) but the recently rolled out pneumococcal conjugate vaccines (PCV) will reduce the disease burden. To better understand the population impact of these vaccines, comprehensive analysis of large collections of pneumococcal isolates sampled prior to vaccination is required. Here we present a population genomic study of the invasive pneumococcal isolates sampled before the implementation of PCV13 in Malawi. MATERIALS AND METHODS We retrospectively sampled and whole genome sequenced 585 invasive isolates from 2004 to 2010. We determine the pneumococcal population genetic structure and assessed serotype prevalence, antibiotic resistance rates, and the occurrence of serotype switching. RESULTS Population structure analysis revealed 22 genetically distinct sequence clusters (SCs), which consisted of closely related isolates. Serotype 1 (ST217), a vaccine-associated serotype in clade SC2, showed highest prevalence (19.3%), and was associated with the highest MDR rate (81.9%) followed by serotype 12F, a non-vaccine serotype in clade SC10 with an MDR rate of 57.9%. Prevalence of serotypes was stable prior to vaccination although there was an increase in the PMEN19 clone, serotype 5 ST289, in clade SC1 in 2010 suggesting a potential undetected local outbreak. Coalescent analysis revealed recent emergence of the SCs and there was evidence of natural capsule switching in the absence of vaccine induced selection pressure. Furthermore, majority of the highly prevalent capsule-switched isolates were associated with acquisition of vaccine-targeted capsules. CONCLUSIONS This study provides descriptions of capsule-switched serotypes and serotypes with potential to cause serotype replacement post-vaccination such as 12F. Continued surveillance is critical to monitor these serotypes and antibiotic resistance in order to design better infection prevention and control measures such as inclusion of emerging replacement serotypes in future conjugate vaccines.
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Affiliation(s)
- Chrispin Chaguza
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jennifer E Cornick
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Cheryl P Andam
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Maaike Alaerts
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Patrick Musicha
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Chikondi Peno
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Naor Bar-Zeev
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Arox W Kamng'ona
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Anmol M Kiran
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Chisomo L Msefula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Department of Biomedical Sciences, University of Malawi College of Medicine, Blantyre, Malawi
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, USA
| | - Robert F Breiman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, USA
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Neil French
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Robert S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi; Division of Infection and Immunity, University College London, London, UK
| | - William P Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Stephen D Bentley
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - Dean B Everett
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
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Competitive Dominance within Biofilm Consortia Regulates the Relative Distribution of Pneumococcal Nasopharyngeal Density. Appl Environ Microbiol 2017; 83:AEM.00953-17. [PMID: 28576759 DOI: 10.1128/aem.00953-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/25/2017] [Indexed: 12/15/2022] Open
Abstract
Streptococcus pneumoniae is a main cause of child mortality worldwide, but strains also asymptomatically colonize the upper airways of most children and form biofilms. Recent studies have demonstrated that ∼50% of colonized children carry at least two different serotypes (i.e., strains) in the nasopharynx; however, studies of how strains coexist are limited. In this work, we investigated the physiological, genetic, and ecological requirements for the relative distribution of densities, and spatial localization, of pneumococcal strains within biofilm consortia. Biofilm consortia were prepared with vaccine type strains (i.e., serotype 6B [S6B], S19F, or S23F) and strain TIGR4 (S4). Experiments first revealed that the relative densities of S6B and S23F were similar in biofilm consortia. The density of S19F strains, however, was reduced to ∼10% in biofilm consortia, including either S6B, S23F, or TIGR4, in comparison to S19F monostrain biofilms. Reduction of S19F density within biofilm consortia was also observed in a simulated nasopharyngeal environment. Reduction of relative density was not related to growth rates, since the Malthusian parameter demonstrated similar rates of change of density for most strains. To investigate whether quorum sensing (QS) regulates relative densities in biofilm consortia, two different mutants were prepared: a TIGR4ΔluxS mutant and a TIGR4ΔcomC mutant. The density of S19F strains, however, was similarly reduced when consortia included TIGR4, TIGR4ΔluxS, or TIGR4ΔcomC Moreover, production of a different competence-stimulating peptide (CSP), CSP1 or CSP2, was not a factor that affected dominance. Finally, a mathematical model, confocal experiments, and experiments using Transwell devices demonstrated physical contact-mediated control of pneumococcal density within biofilm consortia.IMPORTANCEStreptococcus pneumoniae kills nearly half a million children every year, but it also produces nasopharyngeal biofilm consortia in a proportion of asymptomatic children, and these biofilms often contain two strains (i.e., serotypes). In our study, we investigated how strains coexist within pneumococcal consortia produced by vaccine serotypes S4, S6B, S19F, and S23F. Whereas S6B and S23F shared the biofilm consortium, our studies demonstrated reduction of the relative density of S19F strains, to ∼10% of what it would otherwise be if alone, in consortial biofilms formed with S4, S6B, or S23F. This dominance was not related to increased fitness when competing for nutrients, nor was it regulated by quorum-sensing LuxS/AI-2 or Com systems. It was demonstrated, however, to be enhanced by physical contact rather than by a product(s) secreted into the supernatant, as would naturally occur in the semidry nasopharyngeal environment. Competitive interactions within pneumococcal biofilm consortia regulate nasopharyngeal density, a risk factor for pneumococcal disease.
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Comparison of traditional culture and molecular qPCR for detection of simultaneous carriage of multiple pneumococcal serotypes in African children. Sci Rep 2017; 7:4628. [PMID: 28680083 PMCID: PMC5498530 DOI: 10.1038/s41598-017-04915-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/22/2017] [Indexed: 11/29/2022] Open
Abstract
S. pneumoniae is a common colonizer of the human nasopharynx in high income and low-middle income countries. Due to limitations of standard culture methods, the prevalence of concurrent colonization with multiple serotypes is unclear. We evaluated the use of multiplex quantitative PCR (qPCR) to detect multiple pneumococcal serotypes/group colonization in archived nasopharyngeal swabs of pneumococcal conjugate vaccine naive children who had previously been investigated by traditional culture methods. Overall the detection of pneumococcal colonization was higher by qPCR (82%) compared to standard culture (71%; p < 0.001), with a high concordance (kappa = 0.73) of serotypes/groups identified by culture also being identified by qPCR. Also, qPCR was more sensitive in detecting multiple serotype/groups among colonized cases (28.7%) compared to culture (4.5%; p < 0.001). Of the additional serotypes detected only by qPCR, the majority were of lower density (<104 CFU/ml) than the dominant colonizing serotype, with serotype/group 6A/B, 19B/F and 23F being the highest density colonizers, followed by serotype 5 and serogroup 9A/L/N/V being the most common second and third colonizers respectively. The ability of qPCR to detect multiple pneumococcal serotypes at a low carriage density might provide better insight into underlying mechanism for changes in serotype colonization in PCV vaccinated children.
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Pneumococcal Capsular Polysaccharide Immunity in the Elderly. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00004-17. [PMID: 28424198 DOI: 10.1128/cvi.00004-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Immunity to pneumococcal infections is impaired in older people, and current vaccines are poorly protective against pneumococcal disease in this population. Naturally acquired immunity to pneumococcal capsular polysaccharides develops during childhood and is robust in young adults but deteriorates with advanced age. In particular, antibody levels and function are reduced in older people. Pneumococcal vaccines are recommended for people >65 years old. However, the benefits of polysaccharide and protein-conjugated vaccines in this population are small, because of both serotype replacement and incomplete protection against vaccine serotype pneumococcal disease. In this review, we overview the immune mechanisms by which naturally acquired and vaccine-induced pneumococcal capsular polysaccharide immunity declines with age, including altered colonization dynamics, reduced opsonic activity of antibodies (particularly IgM), and impaired mucosal immunity.
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Donkor ES, Annan JA, Badoe EV, Dayie NTKD, Labi AK, Slotved HC. Pneumococcal carriage among HIV infected children in Accra, Ghana. BMC Infect Dis 2017; 17:133. [PMID: 28178935 PMCID: PMC5299768 DOI: 10.1186/s12879-017-2224-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 01/27/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Pneumococcal carriage is the precursor for development of pneumococcal disease, and is also responsible for transmission of the organism from person-to-person. In Africa, little is known about the pneumococcus in relation to people with HIV infection. The aim of the study was to investigate the epidemiology of pneumococcal carriage among HIV infected children visiting a tertiary hospital in Ghana, including the carriage prevalence, risk factors and serotype distribution. METHOD This was a cross sectional study carried out from February to May, 2015 at the HIV Paediatric Clinic of the Korle-Bu Teaching Hospital in Accra, Ghana. One hundred and eighteen HIV infected children were recruited and nasopharyngeal (NP) swabs were collected from them. Epidemiological data on demographic, household and clinical features of the study participants were also collected. The NP specimens were cultured for Streptococcus pneumoniae and the isolates were serotyped by latex agglutination. The data of the study was analysed using STATA 11 (Strata Corp, College Station, TX, USA). RESULTS Prevalence of pneumococcal carriage among the HIV infected children was 27.1% (95% CI: 19.1 to 35.1) and the only factor significantly associated with pneumococcal carriage was the presence of respiratory symptoms (OR, 2.63; CI, 1.06-6.53; p = 0.034). The most prevalent pneumococcal serotype among the study participants was serotype 19F (24.4%), followed by 16F (22%). Serotype coverage of the 13-valent Pneumococcal Conjugate Vaccine in this study was 41.5%. Multiple carriage of pneumococcal serotypes among the positive carriage cases was 34.3%. CONCLUSION Pneumococcal carriage occurred in more than a quarter of the study population and was characterized by predominance of non-vaccine serotypes as well as a high prevalence of multiple carriage. Presence of respiratory symptoms appears to be a major determinant of pneumococcal carriage among the study population.
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Affiliation(s)
- Eric S. Donkor
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences University of Ghana, Accra, Ghana
| | - Jennifer A. Annan
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences University of Ghana, Accra, Ghana
| | - Ebenezer V. Badoe
- Department of Child Health, School of Medicine and Dentistry, University of Ghana, Accra, Ghana
| | - Nicholas T. K. D. Dayie
- Department of Medical Microbiology, School of Biomedical and Allied Health Sciences University of Ghana, Accra, Ghana
| | | | - Hans-Christian Slotved
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
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Protection Elicited by Nasal Immunization with Recombinant Pneumococcal Surface Protein A (rPspA) Adjuvanted with Whole-Cell Pertussis Vaccine (wP) against Co-Colonization of Mice with Streptococcus pneumoniae. PLoS One 2017; 12:e0170157. [PMID: 28103277 PMCID: PMC5245875 DOI: 10.1371/journal.pone.0170157] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/30/2016] [Indexed: 11/19/2022] Open
Abstract
A promising alternative vaccine candidate to reduce the burden of pneumococcal diseases is the protein antigen PspA (Pneumococcal surface protein A). Since concomitant colonization with two or more pneumococcal strains is very common in children, we aimed to determine if immunization with PspA would be able to control co-colonization. We evaluated nasal immunization with recombinant PspA (rPspA) in a model of co-colonization with two strains expressing different PspAs. Mice were immunized intranasally with rPspAs from clades 1 to 4 (rPspA1, rPspA2, rPspA3 or rPspA4) using whole-cell pertussis vaccine (wP) as adjuvant. Mice were then challenged with a mixture of two serotype 6B isolates St491/00 (PspA1) and St472/96 (PspA4). Immunization with rPspA1+wP and rPspA4+wP reduced colonization with both strains and the mixture of rPspA1+rPspA4+wP induced greater reduction than a single antigen. Immunization rPspA1+rPspA4+wP also reduced colonization when challenge experiments were performed with a mixture of isolates of serotypes 6B (PspA3) and 23F (PspA2). Furthermore, none of the tested formulations led to a pronounced increase in colonization of one isolate over the other, showing that the vaccine strategy would not favor replacement. Interestingly, the adjuvant wP by itself already led to some reduction in pneumococcal colonization, indicating the induction of non-specific immune responses. Anti-rPspA IgG was observed in serum, nasal wash (NW) and bronchoalveolar lavage fluid (BALF) samples, whereas animals inoculated with formulations containing the adjuvant wP (with or without rPspA) showed higher levels of IL-6 and KC in NW and increase in tissue macrophages, B cells and CD4+T cells in BALF.
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Pneumococcal Colonization in the Familial Context and Implications for Anti-Pneumococcal Immunization in Adults: Results from the BINOCOLO Project in Sicily. Int J Mol Sci 2017; 18:ijms18010105. [PMID: 28067813 PMCID: PMC5297739 DOI: 10.3390/ijms18010105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/29/2016] [Accepted: 12/29/2016] [Indexed: 01/23/2023] Open
Abstract
The spread of Streptococcus pneumoniae within families has been scarcely investigated so far. This feasibility study aimed to estimate the prevalence of pneumococcal carriage in school-aged children and co-habiting relatives and to explore the potential link between the family environment and the sharing of pneumococcal serotypes covered by the vaccine. Oropharyngeal samples of 146 subjects belonging to 36 different family groups were molecularly tested for pneumococcal detection and serotyping. The overall prevalence of pneumococcal carriage was 65.8% (n = 96/146), whereas it was higher among schoolchildren (77.8%, n = 28/36); subjects of seven years of age had the highest odds of being colonized (odds ratio, OR = 5.176; p = 0.145). Pneumococcal serotypes included in the 13-valent conjugate vaccine formulation were largely detected in the study population and multiple serotypes colonization was considerable. Factors relating to a close proximity among people at the family level were statistically associated with pneumococcal carriage (OR = 2.121; p = 0.049), as well as active smoking habit with a clear dose-response effect (ORs = 1.017–3.326). About half of family clusters evidenced similar patterns of carried pneumococcal serotypes and the odds of sustaining a high level of intrafamilial sharing increased with household size (ORs = 1.083–5.000). This study highlighted the potential role played by the family environment in sustaining both the circulation and horizontal transmission of pneumococcus.
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Collins C, Didelot X. Reconstructing the Ancestral Relationships Between Bacterial Pathogen Genomes. Methods Mol Biol 2017; 1535:109-137. [PMID: 27914076 DOI: 10.1007/978-1-4939-6673-8_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Following recent developments in DNA sequencing technology, it is now possible to sequence hundreds of whole genomes from bacterial isolates at relatively low cost. Analyzing this growing wealth of genomic data in terms of ancestral relationships can reveal many interesting aspects of the evolution, ecology, and epidemiology of bacterial pathogens. However, reconstructing the ancestry of a sample of bacteria remains challenging, especially for the majority of species where recombination is frequent. Here, we review and describe the computational techniques currently available to infer ancestral relationships, including phylogenetic methods that either ignore or account for the effect of recombination, as well as model-based and model-free phylogeny-independent approaches.
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Affiliation(s)
- Caitlin Collins
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK.
| | - Xavier Didelot
- Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK.
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Hausdorff WP, Hanage WP. Interim results of an ecological experiment - Conjugate vaccination against the pneumococcus and serotype replacement. Hum Vaccin Immunother 2016; 12:358-74. [PMID: 26905681 PMCID: PMC5049718 DOI: 10.1080/21645515.2015.1118593] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Streptococcus pneumoniae has more than 95 serotypes, each of which presumably can cause sepsis, meningitis, pneumonia, and acute otitis media. Pneumococcal conjugate vaccines (PCV) targeted against a limited number of serotypes have nonetheless revealed an impressive impact on each manifestation of pneumococcal disease. At the same time, growing evidence of significant non-vaccine type (NVT) replacement disease following implementation of infant PCV programs has raised questions about the long-term viability of PCV immunization strategies and how to optimize PCV formulations. We discuss here theoretical and practical considerations regarding serotype replacement, and provide a snapshot of the most important NVT types seen to date after implementation of the 2 higher-valent PCVs.
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Affiliation(s)
| | - William P Hanage
- b Department of Epidemiology ; Center for Communicable Disease Dynamics; Harvard TH Chan School of Public Health ; Boston , MA , USA
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Echlin H, Frank MW, Iverson A, Chang TC, Johnson MDL, Rock CO, Rosch JW. Pyruvate Oxidase as a Critical Link between Metabolism and Capsule Biosynthesis in Streptococcus pneumoniae. PLoS Pathog 2016; 12:e1005951. [PMID: 27760231 PMCID: PMC5070856 DOI: 10.1371/journal.ppat.1005951] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 09/23/2016] [Indexed: 01/12/2023] Open
Abstract
The pneumococcus is one of the most prodigious producers of hydrogen peroxide amongst bacterial pathogens. Hydrogen peroxide production by the pneumococcus has been implicated in antibiotic synergism, competition between other bacterial colonizers of the nasopharynx, and damage to epithelial cells. However, the role during invasive disease has been less clear with mutants defective in hydrogen peroxide production demonstrating both attenuation and heightened invasive disease capacity depending upon strain and serotype background. This work resolves these conflicting observations by demonstrating that the main hydrogen peroxide producing enzyme of the pneumococcus, SpxB, is required for capsule formation in a strain dependent manner. Capsule production by strains harboring capsules with acetylated sugars was dependent upon the presence of spxB while capsule production in serotypes lacking such linkages were not. The spxB mutant had significantly lower steady-state cellular levels of acetyl-CoA, suggesting that loss of capsule arises from dysregulation of this intermediary metabolite. This conclusion is corroborated by deletion of pdhC, which also resulted in lower steady-state acetyl-CoA levels and phenocopied the capsule expression profile of the spxB mutant. Capsule and acetyl-CoA levels were restored in the spxB and lctO (lactate oxidase) double mutant, supporting the connection between central metabolism and capsule formation. Taken together, these data show that the defect in pathogenesis in the spxB mutant is due to a metabolic imbalance that attenuates capsule formation and not to reduced hydrogen peroxide formation. The pneumococcus polysaccharide capsule is one of the most critical virulence determinants produced by this major human pathogen. The pneumococcus also produces prodigious amounts of hydrogen peroxide via the enzymatic reaction catalyzed by pyruvate oxidase, SpxB. Deletion of spxB resulted in the loss of surface polysaccharide capsule production in a serotype dependent manner with a mirrored effect on the virulence of the mutants. We observed that deletion of spxB reduced the steady-state levels of acetyl-CoA, a key metabolic intermediate in peptidoglycan, fatty acid biosynthesis, and in capsule biosynthesis in a subset of serotypes. These data suggest that the defect in capsule production was due to altered metabolism that results in reduced acetyl-CoA availability. Corroborating these data, we found that capsule biosynthesis was impaired upon loss of PDHC, an additional metabolic enzyme that generates acetyl-CoA. These data reveal a critical link between pneumococcal metabolism and capsule biosynthesis as well as provide a striking example of how a virulence gene can have a differential contribution to pathogenesis dependent upon strain background.
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Affiliation(s)
- Haley Echlin
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Matthew W. Frank
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Amy Iverson
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Ti-Cheng Chang
- Department of Computational Biology, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Michael D. L. Johnson
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Charles O. Rock
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jason W. Rosch
- Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
- * E-mail:
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Recombination in Streptococcus pneumoniae Lineages Increase with Carriage Duration and Size of the Polysaccharide Capsule. mBio 2016; 7:mBio.01053-16. [PMID: 27677790 PMCID: PMC5040112 DOI: 10.1128/mbio.01053-16] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae causes a high burden of invasive pneumococcal disease (IPD) globally, especially in children from resource-poor settings. Like many bacteria, the pneumococcus can import DNA from other strains or even species by transformation and homologous recombination, which has allowed the pneumococcus to evade clinical interventions such as antibiotics and pneumococcal conjugate vaccines (PCVs). Pneumococci are enclosed in a complex polysaccharide capsule that determines the serotype; the capsule varies in size and is associated with properties including carriage prevalence and virulence. We determined and quantified the association between capsule and recombination events using genomic data from a diverse collection of serotypes sampled in Malawi. We determined both the amount of variation introduced by recombination relative to mutation (the relative rate) and how many individual recombination events occur per isolate (the frequency). Using univariate analyses, we found an association between both recombination measures and multiple factors associated with the capsule, including duration and prevalence of carriage. Because many capsular factors are correlated, we used multivariate analysis to correct for collinearity. Capsule size and carriage duration remained positively associated with recombination, although with a reduced P value, and this effect may be mediated through some unassayed additional property associated with larger capsules. This work describes an important impact of serotype on recombination that has been previously overlooked. While the details of how this effect is achieved remain to be determined, it may have important consequences for the serotype-specific response to vaccines and other interventions. IMPORTANCE The capsule determines >90 different pneumococcal serotypes, which vary in capsule size, virulence, duration, and prevalence of carriage. Current serotype-specific vaccines elicit anticapsule antibodies. Pneumococcus can take up exogenous DNA by transformation and insert it into its chromosome by homologous recombination. This mechanism has disseminated drug resistance and generated vaccine escape variants. It is hence crucial to pneumococcal evolutionary response to interventions, but there has been no systematic study quantifying whether serotypes vary in recombination and whether this is associated with serotype-specific properties such as capsule size or carriage duration. Larger capsules could physically inhibit DNA uptake, or given the longer carriage duration for larger capsules, this may promote recombination. We find that recombination varies among capsules and is associated with capsule size, carriage duration, and carriage prevalence and negatively associated with invasiveness. The consequence of this work is that serotypes with different capsules may respond differently to selective pressures like vaccines.
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Valente C, Hinds J, Gould KA, Pinto FR, de Lencastre H, Sá-Leão R. Impact of the 13-valent pneumococcal conjugate vaccine on Streptococcus pneumoniae multiple serotype carriage. Vaccine 2016; 34:4072-8. [PMID: 27325351 DOI: 10.1016/j.vaccine.2016.06.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 05/22/2016] [Accepted: 06/02/2016] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Pneumococcal multiple serotype carriage is important for evolution of the species and to understand how the pneumococcal population is changing with vaccination. We aimed to determine the impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on multiple serotype carriage. METHODS AND MATERIALS Nasopharyngeal samples from fully vaccinated pneumococcal carriers (4 doses of PCV13, n=141, aged 18-72months) or from non-vaccinated pneumococcal carriers (0 doses of any PCV, n=140, same age group) were analyzed. Multiple serotype carriage was evaluated by DNA hybridization with a molecular serotyping microarray that detects all known serotypes. RESULTS Vaccinated children had a lower prevalence of multiple serotype carriage than the non-vaccinated group (20.6% vs 29.3%, p=0.097), and a significantly lower proportion of PCV13 serotypes (6.4% vs 38.5%, p=0.0001). PCV13 serotypes found among vaccinated children were mostly detected as a minor serotype in co-colonization with a more abundant non-vaccine serotype. Vaccinated children were colonized by a significantly higher proportion of commensal non-pneumococcal Streptococcus spp. (58.2% vs 42.8%, p=0.012). In vaccinated children there were significantly less non-vaccine type (NVT) co-colonization events than expected based on the distribution of these serotypes in non-vaccinated children. CONCLUSIONS The results suggest that vaccinated children have lower pneumococcal multiple serotype carriage prevalence due to higher competitive abilities of non-vaccine serotypes expanding after PCV13 use. This might represent an additional benefit of PCV13, as decreased co-colonization rates translate into decreased opportunities for horizontal gene transfer and might have implications for the evolution and virulence of pneumococci.
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Affiliation(s)
- Carina Valente
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Jason Hinds
- Institute for Infection and Immunity, St. George's, University of London, London, UK; BUGS Bioscience, London Bioscience Innovation Centre, London, UK
| | - Katherine A Gould
- Institute for Infection and Immunity, St. George's, University of London, London, UK; BUGS Bioscience, London Bioscience Innovation Centre, London, UK
| | - Francisco R Pinto
- BioISI - Biosystems & Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal; Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, NY, USA
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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Feola TD, Bonville CA, Cibula DA, Jose S, Nattanmai G, Domachowske JB, Suryadevara M. Nasopharyngeal pneumococcal carriage rates among HIV-infected adults following widespread pediatric use of conjugate pneumococcal vaccine-13. Hum Vaccin Immunother 2016; 12:2441-6. [PMID: 27215541 DOI: 10.1080/21645515.2016.1172758] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Nasopharyngeal pneumococcal carriage rates among HIV-infected adults has not been described since conjugate pneumococcal vaccine-13 (PCV13) was added to the universal infant and childhood vaccination schedule in 2010. METHODS HIV-infected adults presenting for routine health care visits to the Designated AIDS Center in Syracuse, NY between December 2013 and June 2015 were eligible for enrollment. Demographic, medical, and social history were recorded after obtaining informed consent. Nasopharyngeal samples were collected and cultured for the presence of Streptococcus pneumoniae using standard microbiologic techniques. Antibiotic susceptibility testing was performed using E-test→. RESULTS 707 nasopharyngeal samples were collected from 414 HIV-infected adults. 18 samples were culture positive for S. pneumoniae; 1 (6%) isolate was of vaccine-type, 9 (50%) were non-vaccine types, and 8 (44%) were non-typeable. The 18 isolates were recovered from 15 different patients (4% of those enrolled). Three patients were culture positive for pneumococcus isolated from 2 consecutive samples, with non-typeable pneumococci identified consecutively from 2 patients and serotype 35B identified consecutively from 1 patient. The most commonly identified non-vaccine serotypes were 35B and 15B/C. Identified pneumococci were penicillin and cefotaxime susceptible. CONCLUSION Four percent of HIV-infected adults in our study population were colonized with S. pneumoniae. The non-vaccine serotypes 35B and 15B/C predominated.
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Affiliation(s)
- Theresa D Feola
- a Division of Infectious Diseases, Department of Medicine, SUNY Upstate Medical University , Syracuse , NY , USA
| | - Cynthia A Bonville
- b Division of Infectious Diseases, Department of Pediatrics, SUNY Upstate Medical University , Syracuse , NY , USA
| | - Donald A Cibula
- c Department of Public Health and Preventive Medicine , SUNY Upstate Medical University , Syracuse , NY , USA
| | - Sherly Jose
- d Division of Infectious Diseases, New York State , Department of Health , Albany , NY
| | - Geetha Nattanmai
- d Division of Infectious Diseases, New York State , Department of Health , Albany , NY
| | - Joseph B Domachowske
- b Division of Infectious Diseases, Department of Pediatrics, SUNY Upstate Medical University , Syracuse , NY , USA
| | - Manika Suryadevara
- b Division of Infectious Diseases, Department of Pediatrics, SUNY Upstate Medical University , Syracuse , NY , USA
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Hu J, Sun X, Huang Z, Wagner AL, Carlson B, Yang J, Tang S, Li Y, Boulton ML, Yuan Z. Streptococcus pneumoniae and Haemophilus influenzae type b carriage in Chinese children aged 12-18 months in Shanghai, China: a cross-sectional study. BMC Infect Dis 2016; 16:149. [PMID: 27080523 PMCID: PMC4831093 DOI: 10.1186/s12879-016-1485-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 03/24/2016] [Indexed: 12/04/2022] Open
Abstract
Background The bacteria Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae type b (Hib) are leading causes of childhood pneumonia and meningitis and are major contributors to worldwide mortality in children younger than 5 years of age. Asymptomatic nasopharyngeal carriage of pneumococcus and Hib was determined for healthy children in Shanghai in 2009. Methods Children from 5 immunization clinics were enrolled in this study. Specimens from the nasopharynx were collected and cultured in Columbia and chocolate agar to identify pneumococcal and Hib carriage. Pneumococcal specimens were serotyped with the Neufeld test, and antibiotic resistance for pneumococcal and Hib specimens used the E-test method. Significance of risk factors for carriage was assessed through chi-square tests. Results Among 614 children, 16.6 % had pneumococcal carriage and 8.0 % Hib carriage. The predominant serotype of pneumococcus that was isolated was 19 F (52.9 %); serotype coverage was 68.6 % for both 7-valent pneumococcal conjugate vaccine (PCV) and PCV-10, and 82.3 % for PCV-13. Household residency and father’s education were both significantly related to pneumococcal and Hib carriage. The majority of S. pneumoniae isolates were sensitive to most antimicrobials but there were high levels of resistance to azithromycin (51.0 %) and erythromycin (51.0 %). Haemophilus influenzae isolates were sensitive to almost all antimicrobials tested although 12.2 % of isolates were resistant to ampicillin. Conclusions The pneumococcal and Hib vaccines require payment, and the children with the highest burden of disease may not be receiving these vaccines. Moreover, the presence of high antibiotic susceptibility towards pneumococcus, and to a lesser extent towards Hib, underscores the need for preventive protection against these diseases. Public funding of pneumococcal and Hib vaccines would be one mechanism to increase uptake of these vaccines.
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Affiliation(s)
- Jiayu Hu
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Xiaodong Sun
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Zhuoying Huang
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Abram L Wagner
- Department of Epidemiology, University of Michigan, 1415 Washington Heights, SPH II, Ann Arbor, MI, 48109, USA
| | - Bradley Carlson
- Department of Epidemiology, University of Michigan, 1415 Washington Heights, SPH II, Ann Arbor, MI, 48109, USA
| | - Jianping Yang
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Suwen Tang
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Yunyi Li
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China
| | - Matthew L Boulton
- Department of Epidemiology, University of Michigan, 1415 Washington Heights, SPH II, Ann Arbor, MI, 48109, USA.
| | - Zhengan Yuan
- Shanghai Centers for Disease Control and Prevention, 1380 Zhongshan West Road, Shanghai, 200336, China.
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