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1. Trends in invasive bacterial diseases during the first 2 years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries and territories in the IRIS Consortium

Author

Shaw, David, Abad, Raquel, Amin-Chowdhury, Zahin, Bautista, Adriana, Bennett, Desiree, Broughton, Karen, Cao, Bin, Casanova, Carlo, Choi, Eun Hwa, Chu, Yiu-Wai, Claus, Heike, Coelho, Juliana, Corcoran, Mary, Cottrell, Simon, Cunney, Robert, Cuypers, Lize, Dalby, Tine, Davies, Heather, de Gouveia, Linda, Deghmane, Ala-Eddine, Demczuk, Walter, Desmet, Stefanie, Domenech, Mirian, Drew, Richard, du Plessis, Mignon, Duarte, Carolina, Erlendsdóttir, Helga, Fry, Norman K, Fuursted, Kurt, Hale, Thomas, Henares, Desiree, Henriques-Normark, Birgitta, Hilty, Markus, Hoffmann, Steen, Humphreys, Hilary, Ip, Margaret, Jacobsson, Susanne, Johnson, Christopher, Johnston, Jillian, Jolley, Keith A, Kawabata, Aníbal, Kozakova, Jana, Kristinsson, Karl G, Krizova, Pavla, Kuch, Alicja, Ladhani, Shamez, Lâm, Thiên-Trí, León, María Eugenia, Lindholm, Laura, Litt, David, Maiden, Martin C J, Martin, Irene, Martiny, Delphine, Mattheus, Wesley, McCarthy, Noel D, Meehan, Mary, Meiring, Susan, Mölling, Paula, Morfeldt, Eva, Morgan, Julie, Mulhall, Robert, Muñoz-Almagro, Carmen, Murdoch, David, Murphy, Joy, Musilek, Martin, Mzabi, Alexandre, Novakova, Ludmila, Oftadeh, Shahin, Perez-Argüello, Amaresh, Pérez-Vázquez, Maria, Perrin, Monique, Perry, Malorie, Prevost, Benoit, Roberts, Maria, Rokney, Assaf, Ron, Merav, Sanabria, Olga Marina, Scott, Kevin J, Sheppard, Carmen, Siira, Lotta, Sintchenko, Vitali, Skoczyńska, Anna, Sloan, Monica, Slotved, Hans-Christian, Smith, Andrew J, Steens, Anneke, Taha, Muhamed-Kheir, Toropainen, Maija, Tzanakaki, Georgina, Vainio, Anni, van der Linden, Mark P G, van Sorge, Nina M, Varon, Emmanuelle, Vohrnova, Sandra, von Gottberg, Anne, Yuste, Jose, Zanella, Rosemeire, Zhou, Fei, and Brueggemann, Angela B

Published
2023
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2. Changes in the incidence of invasive disease due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis during the COVID-19 pandemic in 26 countries and territories in the Invasive Respiratory Infection Surveillance Initiative: a prospective analysis of surveillance data

Author

Brueggemann, Angela B, Jansen van Rensburg, Melissa J, Shaw, David, McCarthy, Noel D, Jolley, Keith A, Maiden, Martin C J, van der Linden, Mark P G, Amin-Chowdhury, Zahin, Bennett, Désirée E, Borrow, Ray, Brandileone, Maria-Cristina C, Broughton, Karen, Campbell, Ruth, Cao, Bin, Casanova, Carlo, Choi, Eun Hwa, Chu, Yiu Wai, Clark, Stephen A, Claus, Heike, Coelho, Juliana, Corcoran, Mary, Cottrell, Simon, Cunney, Robert J, Dalby, Tine, Davies, Heather, de Gouveia, Linda, Deghmane, Ala-Eddine, Demczuk, Walter, Desmet, Stefanie, Drew, Richard J, du Plessis, Mignon, Erlendsdottir, Helga, Fry, Norman K, Fuursted, Kurt, Gray, Steve J, Henriques-Normark, Birgitta, Hale, Thomas, Hilty, Markus, Hoffmann, Steen, Humphreys, Hilary, Ip, Margaret, Jacobsson, Susanne, Johnston, Jillian, Kozakova, Jana, Kristinsson, Karl G, Krizova, Pavla, Kuch, Alicja, Ladhani, Shamez N, Lâm, Thiên-Trí, Lebedova, Vera, Lindholm, Laura, Litt, David J, Martin, Irene, Martiny, Delphine, Mattheus, Wesley, McElligott, Martha, Meehan, Mary, Meiring, Susan, Mölling, Paula, Morfeldt, Eva, Morgan, Julie, Mulhall, Robert M, Muñoz-Almagro, Carmen, Murdoch, David R, Murphy, Joy, Musilek, Martin, Mzabi, Alexandre, Perez-Argüello, Amaresh, Perrin, Monique, Perry, Malorie, Redin, Alba, Roberts, Richard, Roberts, Maria, Rokney, Assaf, Ron, Merav, Scott, Kevin J, Sheppard, Carmen L, Siira, Lotta, Skoczyńska, Anna, Sloan, Monica, Slotved, Hans-Christian, Smith, Andrew J, Song, Joon Young, Taha, Muhamed-Kheir, Toropainen, Maija, Tsang, Dominic, Vainio, Anni, van Sorge, Nina M, Varon, Emmanuelle, Vlach, Jiri, Vogel, Ulrich, Vohrnova, Sandra, von Gottberg, Anne, Zanella, Rosemeire C, and Zhou, Fei

Published
2021
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5. Nasopharyngeal competition dynamics are likely to be altered following vaccine introduction: bacteriocin prevalence and diversity among Icelandic and Kenyan pneumococci

Author

Butler, Madeleine E. B., primary, Jansen van Rensburg, Melissa J., additional, Karani, Angela, additional, Mvera, Benedict, additional, Akech, Donald, additional, Akter, Asma, additional, Forrest, Calum, additional, van Tonder, Andries J., additional, Quirk, Sigríður J., additional, Haraldsson, Gunnsteinn, additional, Bentley, Stephen D., additional, Erlendsdóttir, Helga, additional, Haraldsson, Ásgeir, additional, Kristinsson, Karl G., additional, Scott, J. Anthony G., additional, and Brueggemann, Angela B., additional

Published
2023
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7. Sustained reductions in life-threatening invasive bacterial diseases during the first two years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries participating in the IRIS Consortium

Author

Shaw, David, primary, Abad, Raquel, additional, Amin-Chowdhury, Zahin, additional, Bautista, Adriana, additional, Bennett, Desiree, additional, Broughton, Karen, additional, Cao, Bin, additional, Casanova, Carlo, additional, Choi, Eun Hwa, additional, Chu, Yiu-Wai, additional, Claus, Heike, additional, Coelho, Juliana, additional, Corcoran, Mary, additional, Cottrell, Simon, additional, Cunney, Robert, additional, Cuypers, Lize, additional, Dalby, Tine, additional, Davies, Heather, additional, de Gouveia, Linda, additional, Deghmane, Ala-Eddine, additional, Demczuk, Walter, additional, Desmet, Stefanie, additional, Domenech, Mirian, additional, Drew, Richard, additional, du Plessis, Mignon, additional, Duarte, Carolina, additional, Erlendsdóttir, Helga, additional, Fry, Norman, additional, Fuursted, Kurt, additional, Hale, Thomas, additional, Henares, Desiree, additional, Henriques-Normark, Birgitta, additional, Hilty, Markus, additional, Hoffmann, Steen, additional, Humphreys, Hilary, additional, Ip, Margaret, additional, Jacobsson, Susanne, additional, Johnson, Christopher, additional, Johnston, Jillian, additional, Jolley, Keith A, additional, Kawabata, Aníbal, additional, Kozakova, Jana, additional, Kristinsson, Karl G, additional, Krizova, Pavla, additional, Kuch, Alicja, additional, Ladhani, Shamez, additional, Lâm, Thiên-Trí, additional, María Eugenia, León, additional, Lindholm, Laura, additional, Litt, David, additional, Maiden, Martin CJ, additional, Martin, Irene, additional, Martiny, Delphine, additional, Mattheus, Wesley, additional, McCarthy, Noel D, additional, McElligott, Martha, additional, Meehan, Mary, additional, Meiring, Susan, additional, Mölling, Paula, additional, Morfeldt, Eva, additional, Morgan, Julie, additional, Mulhall, Robert, additional, Muñoz-Almagro, Carmen, additional, Murdoch, David, additional, Murphy, Joy, additional, Musilek, Martin, additional, Mzabi, Alexandre, additional, Novakova, Ludmila, additional, Oftadeh, Shahin, additional, Perez-Arguello, Amaresh, additional, Pérez-Vázquez, Maria, additional, Perrin, Monique, additional, Perry, Malorie, additional, Prevost, Benoit, additional, Roberts, Maria, additional, Rokney, Assaf, additional, Ron, Merav, additional, Sanabria, Olga Marina, additional, Scott, Kevin J, additional, Sheppard, Carmen, additional, Siira, Lotta, additional, Sintchenko, Vitali, additional, Skoczyńska, Anna, additional, Sloan, Monica, additional, Slotved, Hans-Christian, additional, Smith, Andrew J, additional, Steens, Anneke, additional, Taha, Muhamed-Kheir, additional, Toropainen, Maija, additional, Tzanakaki, Georgina, additional, Vainio, Anni, additional, van der Linden, Mark PG, additional, van Sorge, Nina M, additional, Varon, Emmanuelle, additional, Vohrnova, Sandra, additional, Gottberg, Anne von, additional, Yuste, Jose, additional, Zanella, Rosemeire, additional, Zhou, Fei, additional, and Brueggemann, Angela B, additional

Published
2022
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10. Nasopharyngeal competition dynamics are likely to be altered following vaccine introduction: bacteriocin prevalence and diversity among Icelandic and Kenyan pneumococci

Author

Butler, Madeleine EB, primary, Jansen van Rensburg, Melissa J, additional, Karani, Angela, additional, Mvera, Benedict, additional, Akech, Donald, additional, Akter, Asma, additional, Forrest, Calum, additional, van Tonder, Andries J, additional, Quirk, Sigríður J, additional, Haraldsson, Gunnsteinn, additional, Bentley, Stephen D, additional, Erlendsdóttir, Helga, additional, Haraldsson, Ásgeir, additional, Kristinsson, Karl G, additional, Scott, J Anthony G, additional, and Brueggemann, Angela B, additional

Published
2022
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15. Population Genomic Molecular Epidemiological Study of Macrolide-Resistant Streptococcus pyogenes in Iceland, 1995 to 2016: Identification of a Large Clonal Population with a pbp2x Mutation Conferring Reduced In Vitro β-Lactam Susceptibility

Author

Southon, Sara B., Beres, Stephen B., Kachroo, Priyanka, Saavedra, Matthew Ojeda, Erlendsdóttir, Helga, Haraldsson, Gunnsteinn, Yerramilli, Prasanti, Pruitt, Layne, Zhu, Luchang, Musser, James M., Kristinsson, Karl G., Læknadeild (HÍ), Faculty of Medicine (UI), Heilbrigðisvísindasvið (HÍ), School of Health Sciences (UI), Háskóli Íslands, and University of Iceland

Subjects
Antibiotic resistance, Streptococcus pyogenes, Molecular epidemiology, Sýkingar, Macrolides, Population genomics, Erfðarannsóknir, Sýklalyf
Abstract

Publisher's version (útgefin grein), Resistance to macrolide antibiotics is a global concern in the treatment of Streptococcus pyogenes (group A Streptococcus [GAS]) infections. In Iceland, since the detection of the first macrolide-resistant isolate in 1998, three epidemic waves of macrolide-resistant GAS infections have occurred, with peaks in 1999, 2004, and 2008. We conducted whole-genome sequencing of all 1,575 available GAS macrolide-resistant clinical isolates of all infection types collected at the national reference laboratory in Reykjavik, Iceland, from 1998 to 2016. Among 1,515 erythromycin-resistant isolates, 90.3% were of only three emm types, emm4 (n = 713), emm6 (n = 324), and emm12 (n = 332), with each being predominant in a distinct epidemic peak. The antibiotic efflux pump genes, mef(A) and msr(D), were present on chimeric mobile genetic elements in 99.3% of the macrolide-resistant isolates of these emm types. Of note, in addition to macrolide resistance, virtually all emm12 isolates had a single amino acid substitution in penicillin-binding protein PBP2X that conferred a 2-fold increased penicillin G and ampicillin MIC among the isolates tested. We conclude that each of the three large epidemic peaks of macrolide-resistant GAS infections occurring in Iceland since 1998 was caused by the emergence and clonal expansion of progenitor strains, with macrolide resistance being conferred predominantly by inducible Mef(A) and Msr(D) drug efflux pumps. The occurrence of emm12 strains with macrolide resistance and decreased beta-lactam susceptibility was unexpected and is of public health concern., This study was supported in part by the Fondren Foundation, Houston Methodist Hospital and Research Institute, and National Institutes of Health grants AI139369 and AI146771 (to J.M.M.).

Published
2020

16. Native joint infections in Iceland 2003-2017: an increase in postarthroscopic infections.

Author

Lea Gunnlaugsdóttir, Signý, Erlendsdóttir, Helga, Helgason, Kristján Orri, Geirsson, Árni Jón, Thors, Valtýr, Guðmundsson, Sigurður, Gottfreðsson, Magnús, and Gunnlaugsdóttir, Signý Lea

Subjects
ANTIBIOTICS, KNEE joint, JOINT diseases, ARTHROSCOPY, STREPTOCOCCAL diseases, IATROGENIC diseases, RETROSPECTIVE studies, DISEASE incidence, STAPHYLOCOCCAL diseases, ARTIFICIAL joints, STREPTOCOCCUS, SEX distribution, GRAM-negative aerobic bacteria, GRAM-negative bacterial diseases, SYNOVIAL fluid, DISEASE complications
Abstract

Objectives: Nationwide study on the epidemiology, clinical characteristics and outcomes among patients with native joint infection (NJI) in Iceland, 2003-2017.Methods: All positive synovial fluid culture results in Iceland were identified and medical records reviewed.Results: A total of 299 NJI (40 children and 259 adults) were diagnosed in Iceland in 2003-2017, with a stable incidence of 6.3 cases/100 000/year, but marked gender difference among adults (33% women vs 67% men, p<0.001). The knee joint was most commonly affected, and Staphylococcus aureus was the most common isolate in both adults and children, followed by various streptococcal species in adults and Kingella kingae in children. NJI was iatrogenic in 34% of adults (88/259) but comprised 45% among 18-65 years and a stable incidence. Incidence of infections following arthroscopic procedures in adults increased significantly compared with the previous decade (9/100 000/year in 1990-2002 vs 25/100 000/year in 2003-2017, p<0.01) with no significant increase seen in risk per procedure. The proportion of postarthroscopic NJI was 0.17% overall but 0.24% for knee arthroscopy. Patients with postarthroscopic infection were more likely to undergo subsequent arthroplasty when compared with other patients with NJI (p=0.008).Conclusions: The incidence of NJI in Iceland has remained stable. The proportion of iatrogenic infections is high, especially among young adults, with an increase seen in postarthroscopic infections when compared with the previous decade. Although rare, NJI following arthroscopy can be a devastating complication, with significant morbidity and these results, therefore, emphasise the need for firm indications when arthroscopic treatment is considered. [ABSTRACT FROM AUTHOR]

Published
2022
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17. Population Genomic Molecular Epidemiological Study of Macrolide-Resistant Streptococcus pyogenes in Iceland, 1995 to 2016: Identification of a Large Clonal Population with a pbp2x Mutation Conferring Reduced In Vitro β-Lactam Susceptibility

Author

Southon, Sara B., primary, Beres, Stephen B., additional, Kachroo, Priyanka, additional, Saavedra, Matthew Ojeda, additional, Erlendsdóttir, Helga, additional, Haraldsson, Gunnsteinn, additional, Yerramilli, Prasanti, additional, Pruitt, Layne, additional, Zhu, Luchang, additional, Musser, James M., additional, and Kristinsson, Karl G., additional

Published
2020
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18. Population genomic molecular epidemiological study of macrolide resistant Streptococcus pyogenes in Iceland, 1995-2016: Identification of a large clonal population with a pbp2x mutation conferring reduced in vitro β-lactam susceptibility

Author

Southon, Sara B., primary, Beres, Stephen B., additional, Kachroo, Priyanka, additional, Saavedra, Matthew Ojeda, additional, Erlendsdóttir, Helga, additional, Haraldsson, Gunnsteinn, additional, Yerramilli, Prasanti, additional, Pruitt, Layne, additional, Zhu, Luchang, additional, Musser, James M., additional, and Kristinsson, Karl G., additional

Published
2020
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23. The Effect of the 10-Valent Pneumococcal Nontypeable Haemophilus influenzae Protein D Conjugate Vaccine on H. influenzae in Healthy Carriers and Middle Ear Infections in Iceland

Author

Sveinsdóttir, Hildigunnur, primary, Björnsdóttir, Jana Birta, additional, Erlendsdóttir, Helga, additional, Hjálmarsdóttir, Martha Á., additional, Hrafnkelsson, Birgir, additional, Haraldsson, Ásgeir, additional, Kristinsson, Karl G., additional, and Haraldsson, Gunnsteinn, additional

Published
2019
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24. Vaccination of Icelandic Children with the 10-Valent Pneumococcal Vaccine Leads to a Significant Herd Effect among Adults in Iceland

Author

Quirk, Sigríður J., primary, Haraldsson, Gunnsteinn, additional, Hjálmarsdóttir, Martha Á., additional, van Tonder, Andries J., additional, Hrafnkelsson, Birgir, additional, Bentley, Stephen D., additional, Haraldsson, Ásgeir, additional, Erlendsdóttir, Helga, additional, Brueggemann, Angela B., additional, and Kristinsson, Karl G., additional

Published
2019
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25. Genomic Analyses of >3,100 Nasopharyngeal Pneumococci Revealed Significant Differences Between Pneumococci Recovered in Four Different Geographical Regions

Author

van Tonder, Andries J., primary, Bray, James E., additional, Jolley, Keith A., additional, Jansen van Rensburg, Melissa, additional, Quirk, Sigríður J., additional, Haraldsson, Gunnsteinn, additional, Maiden, Martin C. J., additional, Bentley, Stephen D., additional, Haraldsson, Ásgeir, additional, Erlendsdóttir, Helga, additional, Kristinsson, Karl G., additional, and Brueggemann, Angela B., additional

Published
2019
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27. Effect of Vaccination on Pneumococci Isolated from the Nasopharynx of Healthy Children and the Middle Ear of Children with Otitis Media in Iceland

Author

Quirk, Sigríður J., primary, Haraldsson, Gunnsteinn, additional, Erlendsdóttir, Helga, additional, Hjálmarsdóttir, Martha Á., additional, van Tonder, Andries J., additional, Hrafnkelsson, Birgir, additional, Sigurdsson, Samuel, additional, Bentley, Stephen D., additional, Haraldsson, Ásgeir, additional, Brueggemann, Angela B., additional, and Kristinsson, Karl G., additional

Published
2018
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29. Trends in invasive bacterial diseases during the first 2 years of the COVID-19 pandemic: analyses of prospective surveillance data from 30 countries and territories in the IRIS Consortium

Author

Shaw, David, Abad, Raquel, Amin-Chowdhury, Zahin, Bautista, Adriana, Bennett, Desiree, Broughton, Karen, Cao, Bin, Casanova, Carlo, Choi, Eun Hwa, Chu, Yiu-Wai, Claus, Heike, Coelho, Juliana, Corcoran, Mary, Cottrell, Simon, Cunney, Robert, Cuypers, Lize, Dalby, Tine, Davies, Heather, de Gouveia, Linda, Deghmane, Ala-Eddine, Demczuk, Walter, Desmet, Stefanie, Domenech, Mirian, Drew, Richard, du Plessis, Mignon, Duarte, Carolina, Erlendsdóttir, Helga, Fry, Norman K, Fuursted, Kurt, Hale, Thomas, Henares, Desiree, Henriques-Normark, Birgitta, Hilty, Markus, Hoffmann, Steen, Humphreys, Hilary, Ip, Margaret, Jacobsson, Susanne, Johnson, Christopher, Johnston, Jillian, Jolley, Keith A, Kawabata, Aníbal, Kozakova, Jana, Kristinsson, Karl G, Krizova, Pavla, Kuch, Alicja, Ladhani, Shamez, Lâm, Thiên-Trí, León, María Eugenia, Lindholm, Laura, Litt, David, Maiden, Martin C J, Martin, Irene, Martiny, Delphine, Mattheus, Wesley, McCarthy, Noel D, Meehan, Mary, Meiring, Susan, Mölling, Paula, Morfeldt, Eva, Morgan, Julie, Mulhall, Robert, Muñoz-Almagro, Carmen, Murdoch, David, Murphy, Joy, Musilek, Martin, Mzabi, Alexandre, Novakova, Ludmila, Oftadeh, Shahin, Perez-Argüello, Amaresh, Pérez-Vázquez, Maria, Perrin, Monique, Perry, Malorie, Prevost, Benoit, Roberts, Maria, Rokney, Assaf, Ron, Merav, Sanabria, Olga Marina, Scott, Kevin J, Sheppard, Carmen, Siira, Lotta, Sintchenko, Vitali, Skoczyńska, Anna, Sloan, Monica, Slotved, Hans-Christian, Smith, Andrew J, Steens, Anneke, Taha, Muhamed-Kheir, Toropainen, Maija, Tzanakaki, Georgina, Vainio, Anni, van der Linden, Mark P G, van Sorge, Nina M, Varon, Emmanuelle, Vohrnova, Sandra, von Gottberg, Anne, Yuste, Jose, Zanella, Rosemeire, Zhou, Fei, and Brueggemann, Angela B

Abstract

The Invasive Respiratory Infection Surveillance (IRIS) Consortium was established to assess the impact of the COVID-19 pandemic on invasive diseases caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus agalactiae. We aimed to analyse the incidence and distribution of these diseases during the first 2 years of the COVID-19 pandemic compared to the 2 years preceding the pandemic.

Published
2024
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33. Heterogeneity among estimates of the core genome and pan-genome in different pneumococcal populations

Author

van Tonder, Andries J, primary, Bray, James E, additional, Jolley, Keith A, additional, Quirk, Sigríður J, additional, Haraldsson, Gunnsteinn, additional, Maiden, Martin CJ, additional, Bentley, Stephen D, additional, Haraldsson, Ásgeir, additional, Erlendsdóttir, Helga, additional, Kristinsson, Karl G, additional, and Brueggemann, Angela B, additional

Published
2017
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35. Genomics reveals the worldwide distribution of multidrug-resistant serotype 6E pneumococci

Author

van Tonder, Andries J., Bray, James E., Roalfe, Lucy, White, Rebecca, Zancolli, Marta, Quirk, Sigríður J., Haraldsson, Gunnsteinn, Jolley, Keith A., Maiden, Martin C. J., Bentley, Stephen D., Haraldsson, Ásgeir, Erlendsdóttir, Helga, Kristinsson, Karl G., Goldblatt, David, and Brueggemann, Angela B.

Subjects
Adult, Male, Blood Bactericidal Activity, Adolescent, Genotype, STREPTOCOCCUS-PNEUMONIAE, RECOMBINATION, IMMUNOGENICITY, Global Health, Serogroup, Microbiology, DISEASE, Pneumococcal Infections, EVOLUTIONARY GENETICS, Pneumococcal Vaccines, Young Adult, Prevalence, EPIDEMIOLOGY, Humans, MAXIMUM-LIKELIHOOD, Child, Aged, Science & Technology, Genetic Variation, Infant, Bacteriology, 11 Medical And Health Sciences, Middle Aged, 06 Biological Sciences, Molecular Typing, Streptococcus pneumoniae, DISCOVERY, Child, Preschool, Female, 07 Agricultural And Veterinary Sciences, SEROLOGICAL CHARACTERIZATION, Life Sciences & Biomedicine, CONJUGATE VACCINE
Abstract

The pneumococcus is a leading pathogen infecting children and adults. Safe, effective vaccines exist and they work by inducing antibodies to the polysaccharide capsule (unique for each serotype) that surrounds the cell; however, current vaccines are limited by the fact that only a few of the nearly 100 antigenically-distinct serotypes are included in the formulations. Within the serotypes, serogroup 6 pneumococci are a frequent cause of serious disease and a common coloniser of the nasopharynx in children. Serotype 6E was first reported in 2004 but was thought to be rare; however, we and others have detected serotype 6E among recent pneumococcal collections. Therefore, we analysed a diverse dataset of ∼1000 serogroup 6 genomes, assessed the prevalence and distribution of serotype 6E, analysed the genetic diversity among serogroup 6 pneumococci and investigated whether pneumococcal conjugate vaccine (PCV)-induced serotype 6A and 6B antibodies mediated the killing of serotype 6E pneumococci. We found that 43% of all genomes were serotype 6E and they were recovered worldwide from healthy children and patients of all ages with pneumococcal disease. Four genetic lineages, three of which were multidrug-resistant, described ∼90% of the serotype 6E pneumococci. Serological assays demonstrated that vaccine-induced serotype 6B antibodies were able to elicit killing of serotype 6E pneumococci. We also revealed three major genetic clusters of serotype 6A capsular sequences, discovered a new hybrid 6C/6E serotype, and identified 44 examples of serotype switching. Therefore, while vaccines appear to offer protection against serotype 6E, genetic variants may reduce vaccine efficacy in the longer term due to the emergence of serotypes that can evade vaccine-induced immunity. IMPORTANCE: A key virulence factor for the pneumococcus is the polysaccharide capsule, which is also the target for vaccine-mediated protection. Within serogroup 6 there are eight different types, the most common of which were thought to be serotypes 6A, 6B and 6C. Our study characterised ~1000 serogroup 6 pneumococcal genomes and the data showed that serotype 6E, previously thought to be rare, was the predominant serotype. Earlier detection of serotype 6E pneumococci was obscured because they cross-react to the serotype 6B antisera used in the traditional serotyping assay, and it was only by inspection of the capsular locus sequences that the high prevalence and global distribution of serotype 6E was realised. Fortunately, vaccine-induced antibodies elicited killing of serotype 6E pneumococci; however, we also revealed considerable nucleotide sequence variation among serogroup 6 and thus ongoing genome sequence-based surveillance is essential.

Published
2015

36. Putatively novel serotypes and the potential for reduced vaccine effectiveness: capsular locus diversity revealed among 5405 pneumococcal genomes

Author

van Tonder, Andries J., primary, Bray, James E., additional, Quirk, Sigríður J., additional, Haraldsson, Gunnsteinn, additional, Jolley, Keith A., additional, Maiden, Martin C. J., additional, Hoffmann, Steen, additional, Bentley, Stephen D., additional, Haraldsson, Ásgeir, additional, Erlendsdóttir, Helga, additional, Kristinsson, Karl G., additional, and Brueggemann, Angela B., additional

Published
2016
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37. Correction for van Tonder et al., Genomics Reveals the Worldwide Distribution of Multidrug-Resistant Serotype 6E Pneumococci

Author

van Tonder, Andries J., primary, Bray, James E., additional, Roalfe, Lucy, additional, White, Rebecca, additional, Zancolli, Marta, additional, Quirk, Sigríður J., additional, Haraldsson, Gunnsteinn, additional, Jolley, Keith A., additional, Maiden, Martin C. J., additional, Bentley, Stephen D., additional, Haraldsson, Ásgeir, additional, Erlendsdóttir, Helga, additional, Kristinsson, Karl G., additional, Goldblatt, David, additional, and Brueggemann, Angela B., additional

Published
2016
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40. Bacterial meningitis in adults in Iceland, 1995–2010

Author

Þórðardóttir, Ásgerður, primary, Erlendsdóttir, Helga, additional, Sigurðardóttir, Bryndís, additional, Harðardóttir, Hjördís, additional, Reynisson, Ingi Karl, additional, Gottfreðsson, Magnús, additional, and Guðmundsson, Sigurður, additional

Published
2014
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