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Paulo AC, Lança J, Almeida ST, Hilty M, Sá-Leão R. The upper respiratory tract microbiota of healthy adults is affected by Streptococcus pneumoniae carriage, smoking habits, and contact with children. MICROBIOME 2023; 11:199. [PMID: 37658443 PMCID: PMC10474643 DOI: 10.1186/s40168-023-01640-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023]
Abstract
BACKGROUND The microbiota of the upper respiratory tract is increasingly recognized as a gatekeeper of respiratory health. Despite this, the microbiota of healthy adults remains understudied. To address this gap, we investigated the composition of the nasopharyngeal and oropharyngeal microbiota of healthy adults, focusing on the effect of Streptococcus pneumoniae carriage, smoking habits, and contact with children. RESULTS Differential abundance analysis indicated that the microbiota of the oropharynx was significantly different from that of the nasopharynx (P < 0.001) and highly discriminated by a balance between the classes Negativicutes and Bacilli (AUC of 0.979). Moreover, the oropharynx was associated with a more homogeneous microbiota across individuals, with just two vs. five clusters identified in the nasopharynx. We observed a shift in the nasopharyngeal microbiota of carriers vs. noncarriers with an increased relative abundance of Streptococcus, which summed up to 30% vs. 10% in noncarriers and was not mirrored in the oropharynx. The oropharyngeal microbiota of smokers had a lower diversity than the microbiota of nonsmokers, while no differences were observed in the nasopharyngeal microbiota. In particular, the microbiota of smokers, compared with nonsmokers, was enriched (on average 16-fold) in potential pathogenic taxa involved in periodontal diseases of the genera Bacillus and Burkholderia previously identified in metagenomic studies of cigarettes. The microbiota of adults with contact with children resembled the microbiota of children. Specifically, the nasopharyngeal microbiota of these adults had, on average, an eightfold increase in relative abundance in Streptococcus sp., Moraxella catarrhalis, and Haemophilus influenzae, pathobionts known to colonize the children's upper respiratory tract, and a fourfold decrease in Staphylococcus aureus and Staphylococcus lugdunensis. CONCLUSIONS Our study showed that, in adults, the presence of S. pneumoniae in the nasopharynx is associated with a shift in the microbiota and dominance of the Streptococcus genus. Furthermore, we observed that smoking habits are associated with an increase in bacterial genera commonly linked to periodontal diseases. Interestingly, our research also revealed that adults who have regular contact with children have a microbiota enriched in pathobionts frequently carried by children. These findings collectively contribute to a deeper understanding of how various factors influence the upper respiratory tract microbiota in adults. Video Abstract.
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Affiliation(s)
- A Cristina Paulo
- Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - João Lança
- Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sónia T Almeida
- Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Markus Hilty
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Raquel Sá-Leão
- Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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Candeias C, Félix S, Handem S, de Lencastre H, Sá-Leão R. Clonal Changes in the Pneumococcal Population Carried by Portuguese Children during Six Years of Private Use of the 13-Valent Pneumococcal Conjugate Vaccine: the Relative Contribution of Clonal Expansion, Clonal Emergence, and Capsular Switch Events. Microbiol Spectr 2023:e0290922. [PMID: 36946753 PMCID: PMC10100364 DOI: 10.1128/spectrum.02909-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
In Portugal, the 13-valent pneumococcal conjugate vaccine (PCV13) was available for private use from 2010 to 2015 and it was introduced in the National Immunization Program in 2015. We have reported that private use of PCV13 led to extensive serotype replacement and an increase in antimicrobial susceptibility among pneumococci carried by healthy children. We investigated which clonal changes concurred with these observations. A total of 657 pneumococcal strains, representative of a collection of 2,615 isolates, were genotyped by multilocus sequence typing (MLST). The isolates were recovered in 2009 to 2010 (pre-PCV13), 2011 to 2012 (early PCV13), and 2015 to 2016 (late PCV13) from children attending day care centers in two regions of Portugal (one urban, one rural). One-hundred seventy-one sequence types (STs) were identified, corresponding to 18 clonal complexes (CCs) and 58 singletons. Most CCs (n = 17) and several singletons (n = 16) were found in both regions, indicating that they were geographically disseminated. Clonal complexes expressing PCV13 serotypes in circulation in the late PCV13 period were a subset of the ones identified in the pre-PCV13 period and were often associated with antimicrobial resistance. Among those, the most frequent in both regions was CC179, a multidrug-resistant clone of serotype 19F. Serotype replacement, following PCV13 use, was mainly due to expansion of the susceptible lineages expressing non-PCV13 serotypes already in circulation in the pre-PCV13 period. The emergence of ST53, associated with serotype 8, a major cause of disease in several European countries, was observed in the rural region. Potential capsular switching events, unrelated to PCV13 use, were detected. This study improves our understanding of changes triggered by the private use of PCV13 in Portugal. IMPORTANCE Streptococcus pneumoniae (pneumococcus) is a major human respiratory pathogen linked with high morbidity, mortality, and health care-associated costs worldwide. This bacterium often colonizes asymptomatically healthy children. Colonization is a prerequisite for disease and is also essential for transmission between individuals. The 13-valent pneumococcal conjugate vaccine targets 13 of 101 capsular types of pneumococci described to date. This vaccine not only prevents pneumococcal disease but also impacts colonization by decreasing the carriage of vaccine serotypes. Consequently, serotype replacement occurs. The clonal changes occurring during serotype replacement may be due to various mechanisms, such as clonal expansion, emergence, extinction, or capsular switch (vaccine escape). This study shows that in Portugal, the use of PCV13 has led to significant changes in clonal composition and that these were mainly due to the clonal expansion of lineages expressing serotypes not included in the vaccine.
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Affiliation(s)
- Catarina Candeias
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Sofia Félix
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Sara Handem
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, ITQB NOVA, Oeiras, Portugal
- Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, New York, USA
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
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3
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Miellet WR, Almeida ST, Trzciński K, Sá-Leão R. Streptococcus pneumoniae carriage studies in adults: Importance, challenges, and key issues to consider when using quantitative PCR-based approaches. Front Microbiol 2023; 14:1122276. [PMID: 36910231 PMCID: PMC9994646 DOI: 10.3389/fmicb.2023.1122276] [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: 12/12/2022] [Accepted: 01/31/2023] [Indexed: 02/18/2023] Open
Abstract
Streptococcus pneumoniae causes significant morbidity and mortality among older adults. Detection of pneumococcal carriage is an accepted endpoint in pneumococcal conjugate vaccine studies. However, low sensitivity of culture-based approaches and nasopharyngeal samples have hampered adult S. pneumoniae carriage studies in the past. In contrast, detection of adult S. pneumoniae carriers with qPCR-based approaches can achieve high sensitivity and specificity and qPCR-based testing of oral samples improves accuracy of adult carriage detection. In this Viewpoint we outline a strategy for accurate qPCR-based testing. We recommend a dual-target approach for S. pneumoniae qPCR detection as no genetic target is universally present among or solely unique to it. Furthermore, we advise the evaluation of concordance among quantified qPCR targets to improve the accuracy of S. pneumoniae testing and qPCR-based serotyping. We do not recommend omission of qPCR-based oral sample testing as it will likely result in an underestimation of true adult carrier rates.
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Affiliation(s)
- Willem R Miellet
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands.,Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Sónia T Almeida
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Krzysztof Trzciński
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, Netherlands
| | - 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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4
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Evidence for the intermediate disturbance hypothesis and exponential decay in replacement in Streptococcus pneumoniae following use of conjugate vaccines. Sci Rep 2022; 12:7510. [PMID: 35525872 PMCID: PMC9079081 DOI: 10.1038/s41598-022-11279-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/06/2022] [Indexed: 11/12/2022] Open
Abstract
Understanding how pneumococci respond to pneumococcal conjugate vaccines (PCVs) is crucial to predict the impact of upcoming higher-valency vaccines. However, stages in pneumococcal community succession following disturbance are poorly understood as long-time series on carriage are scarce and mostly evaluated at end-point measurements. We used a 20-year cross-sectional dataset of pneumococci carried by Portuguese children, and methods from community ecology, to study community assembly and diversity following use of PCV7 and PCV13. Two successional stages were detected upon introduction of each PCV: one in which non-vaccine serotypes increased in abundance, fitted by a broken-stick model, and a second in which the community returned to the original structure, fitted by a geometric series, but with different serotype profile and a drop in richness as great as 24%. A peak in diversity was observed for levels of intermediate vaccine uptake (30–40%) in agreement with the intermediate disturbance hypothesis. Serotype replacement was fitted by an exponential decay model (R2 = 80%, P < 0.001). The half-life for replacement was 8 years for PCV7 and 10 years for PCV13. The structure of the pneumococcal community is resilient to vaccine pressure. The increasing loss of diversity, however, suggests it could eventually reach a threshold beyond which it may no longer recover.
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Induction of Susceptibility to Disseminated Infection with IgA1 Protease-Producing Encapsulated Pathogens Streptococcus pneumoniae, Haemophilus influenzae Type b, and Neisseria meningitidis. mBio 2022; 13:e0055022. [PMID: 35420467 PMCID: PMC9239265 DOI: 10.1128/mbio.00550-22] [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] [Indexed: 12/02/2022] Open
Abstract
Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae are the principal causes of bacterial meningitis. It is unexplained why only occasional individuals develop invasive infection, while the vast majority remain healthy and develop immunity when encountering these pathogens. A capsular polysaccharide and an IgA1 protease are common to these pathogens. We tested the hypothesis that patients are primed to susceptibility to invasive infection by other bacteria that express the same capsular polysaccharide but no IgA1 protease. Thereby, the subsequently colonizing pathogen may protect its surface with IgA1 protease-generated Fab fragments of IgA1 devoid of Fc-mediated effector functions. Military recruits who remained healthy when acquiring meningococci showed a significant response of inhibitory antibodies against the IgA1 protease of the colonizing clone concurrent with serum antibodies against its capsular polysaccharide. At hospitalization, 70.8% of meningitis patients carried fecal bacteria cross-reactive with the capsule of the actual pathogen, in contrast to 6% of controls (P < 0.0001). These were Escherichia coli K100, K1, and K92 in patients with infection caused by H. influenzae type b and N. meningitidis groups B and C, respectively. This concurred with a significant IgA1 response to the capsule but not to the IgA1 protease of the pathogen. The demonstrated multitude of relationships between capsular types and distinct IgA1 proteases in pneumococci suggests an alternative route of immunological priming associated with recombining bacteria. The findings support the model and offer an explanation for the rare occurrence of invasive diseases in spite of the comprehensive occurrence of the pathogens.
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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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7
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Félix S, Handem S, Nunes S, Paulo AC, Candeias C, Valente C, Simões AS, Almeida ST, Tavares DA, Brito-Avô A, de Lencastre H, Sá-Leão R. Impact of private use of the 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal carriage among Portuguese children living in urban and rural regions. Vaccine 2021; 39:4524-4533. [PMID: 34183206 DOI: 10.1016/j.vaccine.2021.06.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/27/2021] [Accepted: 06/14/2021] [Indexed: 10/21/2022]
Abstract
In Portugal, the 13-valent pneumococcal conjugate vaccine (PCV13) was commercially available between 2010 and 2015, following a decade of private use of PCV7. We evaluated changes on serotype distribution and antimicrobial susceptibility of pneumococci carried by children living in two regions of Portugal (one urban and one rural). Three epidemiological periods were defined: pre-PCV13 (2009-2010), early-PCV13 (2011-2012), and late-PCV13 (2015-2016). Nasopharyngeal samples (n = 4,232) were obtained from children 0-6 years old attending day-care centers. Private use of PCVs was very high in both regions (>75%). Pneumococcal carriage remained stable and high over time (62.1%, 62.4% and 61.6% (p = 0.909) in the urban region; and 59.8%, 62.8%, 59.5% (p = 0.543) in the rural region). Carriage of PCV7 serotypes remained low (5.3%, 7.8% and 4.3% in the urban region; and 2.5%, 3.7% and 4.8% in the rural region). Carriage of PCV13 serotypes not targeted by PCV7 decreased in both the urban (16.4%, 7.3%, and 1.6%; p < 0.001) and rural regions (13.2%, 7.8%, and 1.9%; p < 0.001). This decline was mostly attributable to serotype 19A (14.1%, 4.4% and 1.3% in the urban region; and 11.1%, 3.6% and 0.8% in the rural region, both p < 0.001). Serotype 3 declined over time in the urban region (10.1%, 4.4%, 0.8%; p < 0.001) and had no obvious trend in the rural region (4.2%, 6.7%, 2.4%; p = 0.505). Serotype 6C decreased in both regions while serotypes 11D, 15A/B/C, 16F, 21, 22F, 23A/B, 24F, 35F, and NT were the most prevalent in the late-PCV13 period. Intermediate resistance to penicillin and non-susceptibility to erythromycin decreased significantly in both regions (19.5%, 13.3%, and 9.3%; and 25.4%, 25.9%, and 13.4%; both p < 0.001, respectively in the urban region; and 12.4%, 11.1%, and 2.8% (p < 0.001); and 15.3%, 14.7%, and 9.2% (p = 0.037), respectively, in the rural region). In conclusion, private use of PCV13 led to significant changes on the pneumococcal population carried by children in Portugal.
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Affiliation(s)
- Sofia Félix
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Sara Handem
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Sónia Nunes
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Ana Cristina Paulo
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Catarina Candeias
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Carina Valente
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Alexandra S Simões
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Sónia T Almeida
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | - Débora A Tavares
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
| | | | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, ITQB NOVA, Oeiras, Portugal; Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, NY, USA
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal.
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Iovino F, Henriques-Normark B. Experimental Model for Studies of Pneumococcal Colonization in Older Adults. Am J Respir Crit Care Med 2021; 203:539-540. [PMID: 33075234 PMCID: PMC7924567 DOI: 10.1164/rccm.202009-3681ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Federico Iovino
- Department of Microbiology, Tumor and Cell Biology Karolinska Institute Stockholm, Sweden and
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology Karolinska Institute Stockholm, Sweden and.,Karolinska University Hospital Stockholm, Sweden
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Almeida ST, Paulo AC, Froes F, de Lencastre H, Sá-Leão R. Dynamics of Pneumococcal Carriage in Adults: A New Look at an Old Paradigm. J Infect Dis 2020; 223:1590-1600. [PMID: 32877517 DOI: 10.1093/infdis/jiaa558] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Limited information is available on pneumococcal colonization among adults. We studied pneumococcal carriage dynamics in healthy adults using high-sensitivity approaches. METHODS Eighty-seven adults (25-50 years old) were followed for 6 months in Portugal. Nasopharyngeal, oropharyngeal, and saliva samples were obtained monthly; pneumococcal carriers were also sampled weekly. Carriage was investigated by quantitative polymerase chain reaction (targeting lytA and piaB) and culture. Positive samples were serotyped. RESULTS Approximately 20% of the adults were intermittent carriers; 10% were persistent carriers (>4 months). Pneumococcal acquisition and clearance rates were 16.5 (95% confidence interval [CI], 11.2-24.2) and 95.9 (95% CI, 62.3-145.0) cases/1000 person-weeks, respectively. Living with children increased pneumococcal acquisition (hazard ratio, 9.7 [95% CI, 2.6-20.5]; P < .001). Median duration of carriage was 7 weeks and did not depend on regular contact with children. CONCLUSIONS The pneumococcal carrier state in healthy adults is more dynamic than generally assumed: Acquisition is frequent and duration of carriage is often long. This suggests that some adults may act as reservoirs of pneumococci and hence, depending on the social structure of a community, the magnitude of herd effects potentially attainable through children vaccination may vary. These findings are important when designing strategies to prevent pneumococcal disease in adults.
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Affiliation(s)
- Sónia T Almeida
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana Cristina Paulo
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Filipe Froes
- Unidade de Cuidados Intensivos Médico-Cirúrgicos, Departamento do Tórax, Hospital Pulido Valente Centro Hospitalar Universitário Lisboa Norte, Lisboa, 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, 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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Takeuchi N, Ohkusu M, Hishiki H, Fujii K, Hotta M, Murata S, Ishiwada N. First report on multidrug-resistant non-encapsulated Streptococcus pneumoniae isolated from a patient with pneumonia. J Infect Chemother 2020; 26:749-751. [PMID: 32409019 DOI: 10.1016/j.jiac.2020.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/30/2020] [Accepted: 02/20/2020] [Indexed: 11/25/2022]
Abstract
The non-encapsulated Streptococcus pneumoniae (NESp) has emerged and increased in the clinical setting. The majority of NESp strains have been isolated from the nasopharynxes of healthy carriers and from respiratory specimens of patients with otitis media. NESp strains were shown to be more effective than encapsulated counterparts at forming biofilms. Therefore, NESp should become one of the leading causes of emerging refractory respiratory disease after the introduction of pneumococcal conjugate vaccines. We report the first case of multidrug-resistant - including fluoroquinolone-resistant - NESp isolated from the intrabronchial aspirate of a patient with pneumonia. Drug-resistant NESp infections can possibly emerge as a clinical problem and thus the continuous monitoring of NESp infections is of utmost importance.
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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
| | - Haruka Hishiki
- Department of Pediatrics, Chiba University Hospital, Chiba, Japan
| | - Katsunori Fujii
- Department of Pediatrics, Chiba University Hospital, Chiba, Japan
| | - Megumi Hotta
- Department of Clinical Laboratory, Chiba University Hospital, Chiba University Hospital, Chiba, Chiba, Japan
| | - Shota Murata
- Department of Clinical Laboratory, Chiba University Hospital, Chiba University Hospital, Chiba, Chiba, Japan
| | - Naruhiko Ishiwada
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan
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11
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Almeida ST, Pedro T, Paulo AC, de Lencastre H, Sá-Leão R. Re-evaluation of Streptococcus pneumoniae carriage in Portuguese elderly by qPCR increases carriage estimates and unveils an expanded pool of serotypes. Sci Rep 2020; 10:8373. [PMID: 32433504 PMCID: PMC7239868 DOI: 10.1038/s41598-020-65399-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 04/27/2020] [Indexed: 11/09/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a leading cause of infections worldwide. Disease is preceded by asymptomatic colonization of the upper respiratory tract. Classical culture-based methods (CCBM) suggest that colonization in the elderly is <5%. Recently, use of qPCR has challenged these observations. We estimated pneumococcal carriage prevalence and serotypes among Portuguese elderly using qPCR and compared results with those obtained by CCBM. Nasopharyngeal and oropharyngeal paired samples (599 each) of individuals over 60 years living in nursing (n = 299) or family (n = 300) homes were screened for the presence of pneumococci by qPCR targeting lytA and piaB. Positive samples were molecular serotyped. Use of qPCR improved detection of pneumococci in oropharyngeal samples compared to CCBM: from 0.7% to 10.4% (p < 0.001) in the nursing home collection, and from 0.3% to 5.0% (p < 0.001) in the family home collection. No significant differences were observed between both methods in nasopharyngeal samples (5.4% vs. 5.4% in the nursing homes; and 4.3% vs. 4.7% in the family homes). Twenty-one serotypes/serogroups were detected by qPCR compared to 14 by CCBM. In conclusion, use of qPCR suggests that pneumococcal carriage in Portuguese elderly is approximately 10%, and unveiled a large pool of serotypes. These results are important to understand progression to disease and impact of pneumococcal vaccines in the elderly.
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Affiliation(s)
- Sónia T Almeida
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tânia Pedro
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - A Cristina Paulo
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, 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, 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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Arguedas A, Trzciński K, O'Brien KL, Ferreira DM, Wyllie AL, Weinberger D, Danon L, Pelton SI, Azzari C, Hammitt LL, Sá-Leão R, Brandileone MCC, Saha S, Suaya J, Isturiz R, Jodar L, Gessner BD. Upper respiratory tract colonization with Streptococcus pneumoniae in adults. Expert Rev Vaccines 2020; 19:353-366. [PMID: 32237926 DOI: 10.1080/14760584.2020.1750378] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Most of the current evidence regarding pneumococcal upper respiratory colonization in adults suggests that despite high disease burden, carriage prevalence is low. Contemporary studies on adult pneumococcal colonization have largely followed the pediatric approach by which samples are obtained mostly from the nasopharynx and bacterial detection is evaluated by routine culture alone. Recent evidence suggests that the 'pediatric approach' may be insufficient in adults and pneumococcal detection in this population may be improved by longitudinal studies that include samples from additional respiratory sites combined with more extensive laboratory testing. AREAS COVERED In this article, relevant literature published in peer review journals on adult pneumococcal colonization, epidemiology, detection methods, and recommendations were reviewed. EXPERT OPINION Respiratory carriage of Streptococcus pneumoniae has been underestimated in adults. Contemporary pneumococcal carriage studies in adults that collect samples from alternative respiratory sites such as the oropharynx, saliva, or nasal wash; are culture-enriched for pneumococcus; and use molecular diagnostic methods designed to target two pneumococcal DNA sequences should enhance pneumococcal detection in the adult respiratory tract. This finding may have implications for the interpretation of dynamics of pneumococcal transmission and vaccination.
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Affiliation(s)
- Adriano Arguedas
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Krzysztof Trzciński
- Department of Pediatric Immunology and Infectious Diseases, Wilhelmina's Children Hospital, University Medical Centre Utrecht , Utrecht, The Netherlands
| | - Katherine L O'Brien
- Department of International Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD, USA
| | | | - Anne L Wyllie
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health , New Haven, CT, USA
| | - Daniel Weinberger
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health , New Haven, CT, USA
| | | | - Stephen I Pelton
- Pediatric Infectious Diseases, Department of Pediatrics, Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center , Boston, MA, USA
| | - Chiara Azzari
- Meyer Children's Hospital and University of Florence , Florence, Italy
| | - Laura L Hammitt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health , Baltimore, MD, USA
| | - Raquel Sá-Leão
- Instituto De Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa , Oeiras, Portugal
| | | | - Samir Saha
- Child Health Research Foundation , Matuail, Dhaka, Bangladesh
| | - Jose Suaya
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , New York, NY, USA
| | - Raul Isturiz
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Luis Jodar
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
| | - Bradford D Gessner
- Vaccines Medical Development & Scientific/Clinical Affairs, Pfizer Inc , Collegeville, PA, USA
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13
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Tin Tin Htar M, Sings HL, Syrochkina M, Taysi B, Hilton B, Schmitt HJ, Gessner BD, Jodar L. The impact of pneumococcal conjugate vaccines on serotype 19A nasopharyngeal carriage. Expert Rev Vaccines 2019; 18:1243-1270. [DOI: 10.1080/14760584.2019.1675521] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
| | - Heather L. Sings
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
| | - Maria Syrochkina
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Moscow, Russia
| | - Bulent Taysi
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Istanbul, Turkey
| | - Betsy Hilton
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
| | - Heinz-Josef Schmitt
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
| | - Bradford D. Gessner
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
| | - Luis Jodar
- Vaccines Medical Development and Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
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14
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Takeuchi N, Ohkusu M, Wada N, Kurosawa S, Miyabe A, Yamaguchi M, Nahm MH, Ishiwada N. Molecular typing, antibiotic susceptibility, and biofilm production in nonencapsulated Streptococcus pneumoniae isolated from children in Japan. J Infect Chemother 2019; 25:750-757. [PMID: 31235348 DOI: 10.1016/j.jiac.2019.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 02/04/2019] [Accepted: 02/10/2019] [Indexed: 10/26/2022]
Abstract
The prevalence of nonencapsulated Streptococcus pneumoniae (NESp) has increased with the introduction of pneumococcal conjugate vaccines in children; however, the bacteriological characteristics of NESp have not been sufficiently clarified. In this study, NESp strains isolated from the nasopharyngeal carriage of children from four nursery schools in Japan were analyzed for molecular type, antibiotic susceptibility, and biofilm productivity. A total of 152 putative S. pneumoniae strains were identified by optochin-susceptibility analysis, of which 21 were not serotypeable by slide agglutination, quellung reaction, or multiplex PCR. Among these 21 strains, three were lytA-negative and, therefore, not S. pneumoniae. The remaining 18 strains were positive for lytA, ply, pspK, and bile solubility and were confirmed as NESp. Therefore, the isolation rate of NESp in the S. pneumoniae strains in this study was 12.0% (18/149). Molecular-typing analyses classified five strains as two existing sequence types (STs; ST7502 and ST7786), and 13 strains formed four novel STs. Horizontal spread was suspected, because strains with the same ST were often isolated from the same nursery school. The NESp isolates were generally susceptible to most antimicrobials, with the exception of macrolides; however, all isolates possessed more than one abnormal penicillin-binding protein gene. Furthermore, NESp strains were more effective than encapsulated counterparts at forming biofilms, which showed obvious differences in morphology. These data indicated that NESp strains should be continuously monitored as emerging respiratory pathogens.
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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
| | | | - Satoko Kurosawa
- Kurosawa Children's and Internal Medicine Clinic, Tokyo, Japan
| | - Akiko Miyabe
- Division of Laboratory Medicine and Clinical Genetics, Chiba University Hospital, Chiba, Japan
| | | | - Moon H Nahm
- Division of Pulmonary, Allergy & Critical Care Medicine, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Naruhiko Ishiwada
- Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba, Japan
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Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020. Sci Rep 2019; 9:3285. [PMID: 30824850 PMCID: PMC6397248 DOI: 10.1038/s41598-019-39791-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/21/2019] [Indexed: 11/15/2022] Open
Abstract
Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay – targeting SP2020 (putative transcriptional regulator gene) – and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples.
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16
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Hiller NL, Sá-Leão R. Puzzling Over the Pneumococcal Pangenome. Front Microbiol 2018; 9:2580. [PMID: 30425695 PMCID: PMC6218428 DOI: 10.3389/fmicb.2018.02580] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/09/2018] [Indexed: 12/11/2022] Open
Abstract
The Gram positive bacterium Streptococcus pneumoniae (pneumococcus) is a major human pathogen. It is a common colonizer of the human host, and in the nasopharynx, sinus, and middle ear it survives as a biofilm. This mode of growth is optimal for multi-strain colonization and genetic exchange. Over the last decades, the far-reaching use of antibiotics and the widespread implementation of pneumococcal multivalent conjugate vaccines have posed considerable selective pressure on pneumococci. This scenario provides an exceptional opportunity to study the evolution of the pangenome of a clinically important bacterium, and has the potential to serve as a case study for other species. The goal of this review is to highlight key findings in the studies of pneumococcal genomic diversity and plasticity.
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Affiliation(s)
- N. Luisa Hiller
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States
- Center of Excellence in Biofilm Research, Allegheny Health Network, Pittsburgh, PA, United States
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Oeiras, Portugal
- Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
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Redistribution of Streptococcus pneumoniae Serotypes After Nationwide 13-valent Pneumococcal Conjugate Vaccine Program in Children in Northern Taiwan. Pediatr Infect Dis J 2017. [PMID: 28650416 DOI: 10.1097/inf.0000000000001664] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND After the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) against Streptococcus pneumoniae, public health officials in Taiwan monitored a decline in circulating vaccine serotypes and the emergence of nonvaccine serotypes in children with invasive pneumococcal disease. A gradually expanded PCV13 national immunization program was launched in 2013 in Taiwan. Here, we evaluate the changes in the distribution of pneumococcal serotypes and antimicrobial nonsusceptibility in children during the evolution of vaccination policy. METHODS S. pneumoniae isolates from children with pneumococcal disease were collected and serotyped from 2010 to 2015 in northern Taiwan. PCVs were administered at the recipients' expense between 2010 and 2012, and then PCV13 was partially reimbursed by the government beginning in 2013. The distribution and diversity of serotypes were analyzed along with their antimicrobial susceptibilities. RESULTS Among a total of 498 isolates, the proportion of invasive pneumococcal disease isolates declined (47.1%-10.6%) during the study period, and serotype diversity increased after 2011. Between 2010 and 2012, the dominant serotypes were 19A, 19F, 3, 6B and 14, and serotype 19A rose from 44.1% to 57.5%. Serotypes 19A, 15A, 19F and 15B were more prevalent from 2013 to 2015, and serotype 19A decreased from 42.1% to 4.5%. Serotypes 19F and 15A became the most commonly detected serotypes in 2015. Overall, PCV13 additional serotypes were reduced by 80% (P < 0.0001) but nonvaccine serotypes increased from 8.8% to 51.5% (P < 0.0001). CONCLUSIONS The step-by-step PCV13 national immunization program is effective against pneumococcal disease in Taiwanese children, mainly by reducing PCV13 additional serotypes.
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Abstract
BACKGROUND Pneumococcal infections are the leading cause of vaccine-preventable death in children. In June 2015, the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the Portuguese Immunization Program. We evaluated the cost-effectiveness of children vaccinated with PCV13 versus no vaccination for preventing pneumococcal diseases. METHODS A cohort simulation model for 2014 Portuguese newborns was used, considering a lifetime horizon and existence of herd effect on adults. Model outcomes measured life years gained, direct and indirect healthcare costs and net benefits considering &OV0556;20,000 per life years gained. PCV13 clinical effectiveness rate by serotype covered was assumed similar to PCV7. Patients' resource use was based on 2014 diagnostic-related group database and experts' opinion, while national legislation and official drug cost database were the main sources for unitary costs. Univariate sensitivity analyses were conducted to assess results' effectiveness. RESULTS In base case scenario, PCV13 was a dominant strategy, being associated with better health outcomes and lower costs. In a lifetime, a total of 6238 infections (excluding acute otitis media) and 130 deaths were averted, with a total saving of &OV0556;397,217 ($432,966). Net benefits were estimated above &OV0556;28 million ($30 million). Results were robust in all sensitivity analyses, with positive net benefits, except when herd effect was excluded. CONCLUSIONS Vaccination of children with PCV13 starting in their first year of life is a cost-effective intervention with the potential to save costs to the Portuguese health system and to provide health gains by reducing the burden of pneumococcal disease in the vaccines and through the herd effect of this vaccine.
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19
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Kawaguchiya M, Urushibara N, Aung MS, Shinagawa M, Takahashi S, Kobayashi N. Serotype distribution, antimicrobial resistance and prevalence of pilus islets in pneumococci following the use of conjugate vaccines. J Med Microbiol 2017; 66:643-650. [DOI: 10.1099/jmm.0.000479] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Mitsuyo Kawaguchiya
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Noriko Urushibara
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Meiji Soe Aung
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masaaki Shinagawa
- Division of Laboratory Medicine, Sapporo Medical University Hospital, Sapporo, Japan
| | - Satoshi Takahashi
- Department of Infection Control and Laboratory Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Nobumichi Kobayashi
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan
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20
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Paulo AC, Sá-Leão R. Periodic cycles of pneumococcal serotypes carried by children before and after 7-valent pneumococcal conjugate vaccine. PLoS One 2017; 12:e0176723. [PMID: 28453533 PMCID: PMC5409052 DOI: 10.1371/journal.pone.0176723] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 04/15/2017] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Periodic cycles in the serotype-specific incidence of invasive pneumococcal disease have been described but less is known in carriage. METHODS We analyzed serotype carriage prevalence among children 0-6 years old over a 15-year period that included pre-PCV7 data and a decade of PCV7 use. Mixed generalized additive models were used to study periodic cycles and how PCV7 impacted on them. RESULTS Pneumococcal carriage data of 7,463 children were analyzed. Periodic cycles ranging from 3 to 6 years were observed for PCV7-serotypes (VT) 14, 19F and 23F and for non-PCV7 types (NVT) 3, 6A, 6C, 11A, and NT. An indirect impact of PCV7 on periodic cycles of NVT was observed and could be translated in three ways: (i) a higher amplitude in the PCV7 period (serotypes 3 and 11A), (ii) sustained increase in the prevalence of carriage (serotypes 6C, 19A and NT) and (iii) an increase in the inter-epidemic period (serotypes 3, 6A and NT). An increase in the child's mean age of carriage of VTs 6B, 19F and 23F was observed. Serotypes 3, 6C, 11A and 15A became more frequent in ages previously associated with carriage of VTs. CONCLUSIONS Periodic cycles among serotypes frequently carried exist and can be modeled. These cycles can be perturbed upon introduction of PCVs and can lead to shifts in the mean age of carriage. Cyclic re-emergence of VTs can occur in settings with non-universal vaccine use. These results should be taken into account when interpreting surveillance data on pneumococcal carriage.
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Affiliation(s)
- Ana Cristina Paulo
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Quimíca e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Raquel Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Quimíca e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.,Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
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21
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Allemann A, Frey PM, Brugger SD, Hilty M. Pneumococcal carriage and serotype variation before and after introduction of pneumococcal conjugate vaccines in patients with acute otitis media in Switzerland. Vaccine 2017; 35:1946-1953. [PMID: 28279564 DOI: 10.1016/j.vaccine.2017.02.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/26/2017] [Accepted: 02/02/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND Acute otitis media (AOM) is an important cause for antibiotic prescription within the paediatric population and Streptococcus pneumoniae is a major pathogen associated with AOM episodes. This study aimed at analysing the influence of the heptavalent and 13-valent pneumococcal conjugate vaccines (PCV7 and PCV13) on pneumococcal carriage and serotype distribution in AOM. METHODS Nasopharyngeal swabs (NPS) and middle ear fluid (MEF) were collected within a Swiss surveillance study of outpatients from all ages with AOM between 2004 and 2015, covering three vaccination eras (pre-PCV7, PCV7 and PCV13). Samples were cultured for pneumococcal identification, and the association of vaccine era with pneumococcal carriage was investigated by logistic regression analysis adjusting for sociodemographic factors. FINDINGS In total, 3300 NPS and 620 MEF were included in this study. The number of samples from patients with AOM dropped over vaccination eras and S. pneumoniae was less frequently isolated in the PCV13 era as compared to the other two eras. The latest (PCV13) vaccination era was independently associated with a reduced pneumococcal carriage within NPS (adjusted odds ratio 0.65, 95%-CI 0.45-0.94). Investigating serotype epidemiology, vaccine serotypes decreased significantly after the conjugate vaccine introductions with the exception of serotype 3. Within the non-PCV13 serotypes, a particular increase of serogroups 11, 15 and 23 was observed in both NPS and MEF. CONCLUSION A substantial change in pneumococcal carriage and serotype epidemiology suggests an impact of the conjugate vaccines on pneumococcal AOM in Switzerland.
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Affiliation(s)
- Aurélie Allemann
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Pascal M Frey
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA; Department of General Internal Medicine, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Silvio D Brugger
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Department of Microbiology, The Forsyth Institute, Cambridge, MA, USA; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Markus Hilty
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Department of Infectious Diseases, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
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Single-Step Multiplex PCR Assay for Determining 92 Pneumococcal Serotypes. J Clin Microbiol 2016; 54:2197-200. [PMID: 27280423 DOI: 10.1128/jcm.01156-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 06/03/2016] [Indexed: 12/31/2022] Open
Abstract
For pneumococcal disease surveillance, simple and cost-effective methods capable of determining all serotypes are needed. Combining a single-tube multiplex PCR with fluorescently labeled primers followed by amplicon analysis using automated fluorescent capillary electrophoresis, each serotype of 92 reference isolates and 297 recently collected clinical isolates was successfully determined.
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