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Puzia W, Gawor J, Gromadka R, Żuchniewicz K, Wróbel-Pawelczyk I, Ronkiewicz P, Gołębiewska A, Hryniewicz W, Sadowy E, Skoczyńska A. Highly Resistant Serotype 19A Streptococcus pneumoniae of the GPSC1/CC320 Clone from Invasive Infections in Poland Prior to Antipneumococcal Vaccination of Children. Infect Dis Ther 2023; 12:2017-2037. [PMID: 37442903 PMCID: PMC10505132 DOI: 10.1007/s40121-023-00842-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
INTRODUCTION The introduction of pneumococcal conjugate vaccines (PCV) into the national immunization programs (NIPs) has significantly reduced the number of pneumococcal infections. However, infections caused by isolates of non-vaccine serotypes (NVT) started spreading shortly thereafter and strains of NVT 19A have become the main cause of invasive pneumococcal disease burden worldwide. The aim of the study was to characterize serotype 19A invasive pneumococci of GPSC1/CC320 circulating in Poland before the introduction of PCV into the Polish NIP in 2017 and to compare them to isolates from other countries where PCVs were implemented much earlier than in Poland. METHODS All the GPSC1/CC320 isolates were analyzed by serotyping, susceptibility testing, and whole genome sequencing followed by analyses of resistome, virulome, and core genome multilocus sequence typing (cgMLST), including comparative analysis with isolates with publicly accessible genomic sequences (PubMLST). RESULTS During continuous surveillance the NRCBM collected 4237 invasive Streptococcus pneumoniae isolates between 1997 and 2016, including 200 isolates (4.7%) of serotype 19A. The most prevalent among 19A pneumococci were highly resistant representatives of Global Pneumococcal Sequence Cluster 1/Clonal Complex 320, GPSC1/CC320 (n = 97, 48.5%). Isolates of GPSC1/CC320 belonged to three sequence types (STs): ST320 (75.2%) ST4768 (23.7%), and ST15047 (1.0%), which all represented the 19A-III cps subtype and had complete loci for both PI-1 and PI-2 pili types. On the basis of the cgMLST analysis the majority of Polish GPSC1/CC320 isolates formed a group clearly distinct from pneumococci of this clone observed in other countries. CONCLUSION Before introduction of PCV in the Polish NIP we noticed an unexpected increase of serotype 19A in invasive pneumococcal infections, with the most common being representatives of highly drug-resistant GPSC1/CC320 clone, rarely identified in Europe both before and even after PCV introduction.
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Affiliation(s)
- Weronika Puzia
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
- DNA Sequencing and Synthesis Facility, Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a Str., 02-106, Warsaw, Poland
| | - Jan Gawor
- DNA Sequencing and Synthesis Facility, Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a Str., 02-106, Warsaw, Poland
| | - Robert Gromadka
- DNA Sequencing and Synthesis Facility, Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a Str., 02-106, Warsaw, Poland
| | - Karolina Żuchniewicz
- DNA Sequencing and Synthesis Facility, Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a Str., 02-106, Warsaw, Poland
| | - Izabela Wróbel-Pawelczyk
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
| | - Patrycja Ronkiewicz
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
| | - Agnieszka Gołębiewska
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
| | - Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland
| | - Anna Skoczyńska
- Department of Epidemiology and Clinical Microbiology, National Reference Centre for Bacterial Meningitis, National Medicines Institute, Chełmska 30/34 Str., 00-725, Warsaw, Poland.
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2
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Arends DW, Miellet WR, Langereis JD, Ederveen THA, van der Gaast–de Jongh CE, van Scherpenzeel M, Knol MJ, van Sorge NM, Lefeber DJ, Trzciński K, Sanders EAM, Dorfmueller HC, Bootsma HJ, de Jonge MI. Examining the Distribution and Impact of Single-Nucleotide Polymorphisms in the Capsular Locus of Streptococcus pneumoniae Serotype 19A. Infect Immun 2021; 89:e0024621. [PMID: 34251291 PMCID: PMC8519296 DOI: 10.1128/iai.00246-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/02/2021] [Indexed: 11/30/2022] Open
Abstract
Streptococcus pneumoniae serotype 19A prevalence has increased after the implementation of the PCV7 and PCV10 vaccines. In this study, we have provided, with high accuracy, the genetic diversity of the 19A serotype in a cohort of Dutch invasive pneumococcal disease patients and asymptomatic carriers obtained in the period from 2004 to 2016. The whole genomes of the 338 pneumococcal isolates in this cohort were sequenced and their capsule (cps) loci compared to examine their diversity and determine the impact on the production of capsular polysaccharide (CPS) sugar precursors and CPS shedding. We discovered 79 types with a unique cps locus sequence. Most variation was observed in the rmlB and rmlD genes of the TDP-Rha synthesis pathway and in the wzg gene, which is of unknown function. Interestingly, gene variation in the cps locus was conserved in multiple alleles. Using RmlB and RmlD protein models, we predict that enzymatic function is not affected by the single-nucleotide polymorphisms as identified. To determine if RmlB and RmlD function was affected, we analyzed nucleotide sugar levels using ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS). CPS precursors differed between 19A cps locus subtypes, including TDP-Rha, but no clear correlation was observed. Also, significant differences in multiple nucleotide sugar levels were observed between phylogenetically branched groups. Because of indications of a role for Wzg in capsule shedding, we analyzed if this was affected. No clear indication of a direct role in shedding was found. We thus describe genotypic variety in rmlB, rmlD, and wzg in serotype 19A in the Netherlands, for which we have not discovered an associated phenotype.
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Affiliation(s)
- D. W. Arends
- Laboratory of Medical Immunology, Radboud Center for Infectious Diseases, Radboud Institute for Molecular Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - W. R. Miellet
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - J. D. Langereis
- Laboratory of Medical Immunology, Radboud Center for Infectious Diseases, Radboud Institute for Molecular Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - T. H. A. Ederveen
- Center for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - C. E. van der Gaast–de Jongh
- Laboratory of Medical Immunology, Radboud Center for Infectious Diseases, Radboud Institute for Molecular Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M. van Scherpenzeel
- GlycoMScan, Oss, The Netherlands
- Translational Metabolic Laboratory, Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - M. J. Knol
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - N. M. van Sorge
- Department of Medical Microbiology and Infection Prevention, Netherlands Reference Laboratory for Bacterial Meningitis, Amsterdam Institute for Infection and Immunity, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - D. J. Lefeber
- Translational Metabolic Laboratory, Department of Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - K. Trzciński
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - E. A. M. Sanders
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - H. C. Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - H. J. Bootsma
- Laboratory of Medical Immunology, Radboud Center for Infectious Diseases, Radboud Institute for Molecular Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - M. I. de Jonge
- Laboratory of Medical Immunology, Radboud Center for Infectious Diseases, Radboud Institute for Molecular Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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3
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Carbon Source-Dependent Changes of the Structure of Streptococcus pneumoniae Capsular Polysaccharide with Serotype 6F. Int J Mol Sci 2021; 22:ijms22094580. [PMID: 33925509 PMCID: PMC8123889 DOI: 10.3390/ijms22094580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 11/30/2022] Open
Abstract
The structure of the exopolysaccharide capsule of Streptococcus pneumoniae is defined by the genetic arrangement of the capsule operon allowing the unequivocal identification of the pneumococcal serotype. Here, we investigated the environment-dependent composition of the polysaccharide structure of S. pneumoniae serotype 6F. When grown in a chemically defined medium (CDM) with glucose versus galactose, the exopolysaccharide capsule of the serotype 6F strains reveals a ratio of 1/0.6 or 1/0.3 for galactose/glucose in the capsule by 1H-NMR analyses, respectively. Increased production of the capsule precursor UDP-glucose has been identified by 31P-NMR in CDM with glucose. Flow cytometric experiments using monoclonal antibodies showed decreased labelling of Hyp6AG4 (specific for serotype 6A) antibodies when 6F is grown in glucose as compared to galactose, which mirrors the 1H-NMR results. Whole-genome sequencing analyses of serotype 6F isolates suggested that the isolates evolved during two different events from serotype 6A during the time when the 13-valent pneumococcal conjugate vaccine (PCV-13) was introduced. In conclusion, this study shows differences in the capsular structure of serotype 6F strains using glucose as compared to galactose as the carbon source. Therefore, 6F strains may show slightly different polysaccharide composition while colonizing the human nasopharynx (galactose rich) as compared to invasive locations such as the blood (glucose rich).
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Comparative genomics of invasive Streptococcus pneumoniae CC320/271 serotype 19F/19A before the introduction of pneumococcal vaccine in India. Mol Biol Rep 2021; 48:3265-3276. [PMID: 33876375 DOI: 10.1007/s11033-021-06353-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
The emergence of multi drug resistant clone CC320 serotype19F/19A and their capsular (cps) antigenic variants due to selective pressures such as vaccine had been reported worldwide. Hence, it is important to identify the prevalent clones, sequence types and cps variants of serotype 19F/19A in India, where PCV13 has been recently introduced. Multi-locus sequence typing (MLST) was performed for all (n = 21) invasive S. pneumoniae isolates of serotype 19A (n = 5) and 19F (n = 16) collected between the years 2012 and 2018 from children less than 5 years. The genome characterization by whole genome sequencing for the Sequence types (STs) 320 and 271(n = 7) were performed and compared with another six Indian WGSs of similar STs available from the GPS platform. The predominant STs in the serotype 19F/19A study isolates were of CC320: ST 320, 236 and 271, associated with PMEN clone Taiwan19F-14. The WGSs of CC320 study isolates showed high genomic similarity to the Taiwan19F-14 clone, and the penicillin binding protein (PBP) amino acid sequence similarity was 100% for PBP1A, 93% for PBP 2B and 2X. Whilst PBP comparison with other global MDR ST320 strains revealed that the ST320 clones in India are of low-level penicillin resistance. The presence of a few ST320/19A/19F invasive isolates with high similarity to the Taiwan clone suggests slow and gradual expansion of Taiwan19F-14 associated CC320 clones in India. Since serotype 19F/19A is covered by PCV13 vaccine, the expansion of 19F/19A cones with non-PCV13 vaccine serotype in India should be monitored.
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Tzani-Tzanopoulou P, Skliros D, Megremis S, Xepapadaki P, Andreakos E, Chanishvili N, Flemetakis E, Kaltsas G, Taka S, Lebessi E, Doudoulakakis A, Papadopoulos NG. Interactions of Bacteriophages and Bacteria at the Airway Mucosa: New Insights Into the Pathophysiology of Asthma. FRONTIERS IN ALLERGY 2021; 1:617240. [PMID: 35386933 PMCID: PMC8974763 DOI: 10.3389/falgy.2020.617240] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/29/2020] [Indexed: 12/16/2022] Open
Abstract
The airway epithelium is the primary site where inhaled and resident microbiota interacts between themselves and the host, potentially playing an important role on allergic asthma development and pathophysiology. With the advent of culture independent molecular techniques and high throughput technologies, the complex composition and diversity of bacterial communities of the airways has been well-documented and the notion of the lungs' sterility definitively rejected. Recent studies indicate that the microbial composition of the asthmatic airways across the spectrum of disease severity, differ significantly compared with healthy individuals. In parallel, a growing body of evidence suggests that bacterial viruses (bacteriophages or simply phages), regulating bacterial populations, are present in almost every niche of the human body and can also interact directly with the eukaryotic cells. The triptych of airway epithelial cells, bacterial symbionts and resident phages should be considered as a functional and interdependent unit with direct implications on the respiratory and overall homeostasis. While the role of epithelial cells in asthma pathophysiology is well-established, the tripartite interactions between epithelial cells, bacteria and phages should be scrutinized, both to better understand asthma as a system disorder and to explore potential interventions.
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Affiliation(s)
- Panagiota Tzani-Tzanopoulou
- Allergy and Clinical Immunology Unit, 2nd Pediatric Clinic, National and Kapodistrian University of Athens, Athens, Greece
| | - Dimitrios Skliros
- Laboratory of Molecular Biology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - Spyridon Megremis
- Division of Evolution and Genomic Sciences, University of Manchester, Manchester, United Kingdom
| | - Paraskevi Xepapadaki
- Allergy and Clinical Immunology Unit, 2nd Pediatric Clinic, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelos Andreakos
- Center for Clinical, Experimental Surgery and Translational Research of the Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Nina Chanishvili
- Laboratory for Genetics of Microorganisms and Bacteriophages, Eliava Institute of Bacteriophage, Microbiology & Virology, Tbilisi, GA, United States
| | - Emmanouil Flemetakis
- Laboratory of Molecular Biology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, Athens, Greece
| | - Grigoris Kaltsas
- Department of Electrical and Electronic Engineering, University of West Attica, Athens, Greece
| | - Styliani Taka
- Allergy and Clinical Immunology Unit, 2nd Pediatric Clinic, National and Kapodistrian University of Athens, Athens, Greece
| | - Evangelia Lebessi
- Department of Microbiology, P. & A. Kyriakou Children's Hospital, Athens, Greece
| | | | - Nikolaos G Papadopoulos
- Allergy and Clinical Immunology Unit, 2nd Pediatric Clinic, National and Kapodistrian University of Athens, Athens, Greece.,Division of Evolution and Genomic Sciences, University of Manchester, Manchester, United Kingdom
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6
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Troxler LJ, Werren JP, Schaffner TO, Mostacci N, Vermathen P, Vermathen M, Wüthrich D, Simillion C, Brugger SD, Bruggmann R, Hathaway LJ, Furrer J, Hilty M. Carbon source regulates polysaccharide capsule biosynthesis in Streptococcus pneumoniae. J Biol Chem 2019; 294:17224-17238. [PMID: 31594867 PMCID: PMC6873171 DOI: 10.1074/jbc.ra119.010764] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 10/02/2019] [Indexed: 11/06/2022] Open
Abstract
The exopolysaccharide capsule of Streptococcus pneumoniae is an important virulence factor, but the mechanisms that regulate capsule thickness are not fully understood. Here, we investigated the effects of various exogenously supplied carbohydrates on capsule production and gene expression in several pneumococcal serotypes. Microscopy analyses indicated a near absence of the capsular polysaccharide (CPS) when S. pneumoniae was grown on fructose. Moreover, serotype 7F pneumococci produced much less CPS than strains of other serotypes (6B, 6C, 9V, 15, and 23F) when grown on glucose or sucrose. RNA-sequencing revealed carbon source-dependent regulation of distinct genes of WT strains and capsule-switch mutants of serotypes 6B and 7F, but could not explain the mechanism of capsule thickness regulation. In contrast, 31P NMR of whole-cell extract from capsule-knockout strains (Δcps) clearly revealed the accumulation or absence of capsule precursor metabolites when cells were grown on glucose or fructose, respectively. This finding suggests that fructose uptake mainly results in intracellular fructose 1-phosphate, which is not converted to CPS precursors. In addition, serotype 7F strains accumulated more precursors than did 6B strains, indicating less efficient conversion of precursor metabolites into the CPS in 7F, in line with its thinner capsule. Finally, isotopologue sucrose labeling and NMR analyses revealed that the uptake of the labeled fructose subunit into the capsule is <10% that of glucose. Our findings on the effects of carbon sources on CPS production in different S. pneumoniae serotypes may contribute to a better understanding of pneumococcal diseases and could inform future therapeutic approaches.
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Affiliation(s)
- Lukas J Troxler
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Joel P Werren
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Thierry O Schaffner
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Nadezda Mostacci
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Peter Vermathen
- Department of BioMedical Research and Radiology, University of Bern and Inselspital, 3012 Bern, Switzerland
| | - Martina Vermathen
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Daniel Wüthrich
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland.,Applied Microbiology Research Unit, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland.,Division of Clinical Microbiology, University Hospital Basel, 4031 Basel, Switzerland
| | - Cedric Simillion
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland
| | - Silvio D Brugger
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland.,The Forsyth Institute (Microbiology), Cambridge, Massachusetts 02142.,Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts 02142
| | - Rémy Bruggmann
- Interfaculty Bioinformatics Unit and Swiss Institute of Bioinformatics, University of Bern, 3012 Bern, Switzerland
| | - Lucy J Hathaway
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
| | - Julien Furrer
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, Faculty of Medicine, University of Bern, 3001 Bern, Switzerland
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Abstract
Streptococcus pneumoniae (the pneumoccus) is the leading cause of otitis media, community-acquired pneumonia, and bacterial meningitis. The success of the pneumococcus stems from its ability to persist in the population as a commensal and avoid killing by immune system. This chapter first reviews the molecular mechanisms that allow the pneumococcus to colonize and spread from one anatomical site to the next. Then, it discusses the mechanisms of inflammation and cytotoxicity during emerging and classical pneumococcal infections.
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8
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Hennessey JP, Costantino P, Talaga P, Beurret M, Ravenscroft N, Alderson MR, Zablackis E, Prasad AK, Frasch C. Lessons Learned and Future Challenges in the Design and Manufacture of Glycoconjugate Vaccines. CARBOHYDRATE-BASED VACCINES: FROM CONCEPT TO CLINIC 2018. [DOI: 10.1021/bk-2018-1290.ch013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
| | | | - Philippe Talaga
- Department of Analytical Research and Development, Sanofi Pasteur, Marcy l’Etoile 69280, France
| | - Michel Beurret
- Janssen Vaccines & Prevention B.V., Leiden, 2301 CA, The Netherlands
| | - Neil Ravenscroft
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | | | - Earl Zablackis
- Analytical Process Technology, Sanofi Pasteur, Swiftwater, Pennsylvania 18370, United States
| | - A. Krishna Prasad
- Pfizer Vaccines Research and Development, Pearl River, New York 10965, United States
| | - Carl Frasch
- Consultant, Martinsburg, West Virginia 25402, United States
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9
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Kapatai G, Sheppard CL, Troxler LJ, Litt DJ, Furrer J, Hilty M, Fry NK. Pneumococcal 23B Molecular Subtype Identified Using Whole Genome Sequencing. Genome Biol Evol 2017; 9:2122-2135. [PMID: 28910966 PMCID: PMC5581491 DOI: 10.1093/gbe/evx092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2017] [Indexed: 01/20/2023] Open
Abstract
The polysaccharide capsule is a major virulence factor of Streptococcus pneumoniae and the target of all currently licensed pneumococcal vaccines. At present, there are 92 serologically distinct pneumococcal serotypes. Structural and antigenic variation of capsular types is the result of genetic variation within the capsular polysaccharide synthesis (CPS) locus; however, genetic variation may not always result in phenotypic differences which produce novel serotypes. With the introduction of high throughput whole genome sequencing, discovery of novel genotypic variants is not unexpected and this study describes a novel variant of the serotype 23B CPS operon. This novel variant was characterized as a novel genotypic subtype (23B1) with ∼70% homology to the published 23B CPS sequence. High sequence variability was determined in eight cps genes involved in sugar biosynthesis. However, there was no distinction between the classic 23B serotype and 23B1 serologically or in terms of polysaccharide structure. Phylogenetic and eBURST analysis revealed a distinct lineage for 23B1 with multiple clones (UK, Thailand, and USA) that arose at different points during pneumococcal evolution. Analysis of the UK S. pneumoniae isolates (n = 121) revealed an upsurge of 23B1 ST2372 in 2011, after which this previously unseen ST increased to reach 50% proportion of the 23B sequenced isolates from 2013 and remained prevalent within our sequenced isolates from later years. Therefore, although the 23B1 variant appears to have no phenotypic impact and cannot be considered as novel serotype, it appears to have led to a genetic restructuring of the UK serotype 23B population.
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Affiliation(s)
- Georgia Kapatai
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, National Infection Service, London, United Kingdom
| | - Carmen L Sheppard
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, National Infection Service, London, United Kingdom
| | - Lukas J Troxler
- Institute for Infectious Diseases, University of Bern, Switzerland
| | - David J Litt
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, National Infection Service, London, United Kingdom
| | - Julien Furrer
- Department of Chemistry and Biochemistry, University of Bern, Switzerland
| | - Markus Hilty
- Institute for Infectious Diseases, University of Bern, Switzerland.,Department of Infectious Diseases, Bern University Hospital, Inselspital, University of Bern, Switzerland
| | - Norman K Fry
- Respiratory and Vaccine Preventable Bacteria Reference Unit, Public Health England, National Infection Service, London, United Kingdom
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