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Hazenberg P, Robinson RE, Farrar M, Solorzano C, Hyder-Wright A, Liatsikos K, Brunning J, Fleet H, Bettam A, Howard A, Kenny-Nyazika T, Urban B, Mitsi E, El Safadi D, Davies K, Lesosky M, Gordon SB, Ferreira DM, Collins AM. Serotype 3 Experimental Human Pneumococcal Challenge (EHPC) study protocol: dose ranging and reproducibility in a healthy volunteer population (challenge 3). BMJ Open 2024; 14:e075948. [PMID: 38199622 PMCID: PMC10806732 DOI: 10.1136/bmjopen-2023-075948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 11/19/2023] [Indexed: 01/12/2024] Open
Abstract
INTRODUCTION Since the introduction of pneumococcal conjugate vaccines, pneumococcal disease rates have declined for many vaccine-type serotypes. However, serotype 3 (SPN3) continues to cause significant disease and is identified in colonisation epidemiological studies as one of the top circulating serotypes in adults in the UK. Consequently, new vaccines that provide greater protection against SPN3 colonisation/carriage are urgently needed. The Experimental Human Pneumococcal Challenge (EHPC) model is a unique method of determining pneumococcal colonisation rates, understanding acquired immunity, and testing vaccines in a cost-effective manner. To enhance the development of effective pneumococcal vaccines against SPN3, we aim to develop a new relevant and safe SPN3 EHPC model with high attack rates which could be used to test vaccines using small sample size. METHODS AND ANALYSIS This is a human challenge study to establish a new SPN3 EHPC model, consisting of two parts. In the dose-ranging/safety study, cohorts of 10 healthy participants will be challenged with escalating doses of SPN3. If first challenge does not lead into colonisation, participants will receive a second challenge 2 weeks after. Experimental nasopharyngeal (NP) colonisation will be determined using nasal wash sampling. Using the dose that results in ≥50% of participants being colonised, with a high safety profile, we will complete the cohort with another 33 participants to check for reproducibility of the colonisation rate. The primary outcome of this study is to determine the optimal SPN3 dose and inoculation regime to establish the highest rates of NP colonisation in healthy adults. Secondary outcomes include determining density and duration of experimental SPN3 NP colonisation and characterising mucosal and systemic immune responses to SPN3 challenge. ETHICS AND DISSEMINATION This study is approved by the NHS Research and Ethics Committee (reference 22/NW/0051). Findings will be published in peer-reviewed journals and reports will be made available to participants.
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Affiliation(s)
- Phoebe Hazenberg
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ryan E Robinson
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Respiratory Department, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - Madlen Farrar
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Carla Solorzano
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - Angela Hyder-Wright
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Respiratory Department, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | | | - Jaye Brunning
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Hannah Fleet
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Amy Bettam
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ashleigh Howard
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Britta Urban
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - Elena Mitsi
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - Dima El Safadi
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Kelly Davies
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Maia Lesosky
- Global Health Trials Unit, Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Stephen B Gordon
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Daniela M Ferreira
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - Andrea M Collins
- Liverpool Vaccine Group, Liverpool School of Tropical Medicine, Liverpool, UK
- Respiratory Department, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
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2
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Doherty K, Dula D, Chirwa A, Nsomba E, Nkhoma VS, Toto N, Chikaonda T, Kamng'ona R, Phiri J, Reiné J, Ndaferankhande J, Makhaza L, Banda P, Jambo K, Ferreira DM, Gordon SB. Experimental pneumococcal carriage in people living with HIV in Malawi: the first controlled human infection model in a key at-risk population. Wellcome Open Res 2024; 9:2. [PMID: 38362541 PMCID: PMC10864820 DOI: 10.12688/wellcomeopenres.19949.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2023] [Indexed: 02/17/2024] Open
Abstract
Background: As well as suffering a high burden of pneumococcal disease people living with HIV (PLHIV) may contribute to community transmission in sub-Saharan African (sSA) settings. Pneumococcal vaccination is not currently offered to PLHIV in sSA but may prevent disease and reduce transmission. More evidence of vaccine effectiveness against carriage in PLHIV is needed. An Experimental Human Pneumococcal Carriage model (EHPC) has been safely and acceptably used in healthy adults in Malawi to evaluate pneumococcal vaccines against carriage and to identify immune correlates of protection from carriage. This study will establish the same model in PLHIV and will be the first controlled human infection model (CHIM) in this key population. Methods: Healthy participants with and without HIV will be inoculated intranasally with Streptococcus pneumoniae serotype 6B. Sequential cohorts will be challenged with increasing doses to determine the optimal safe challenge dose to establish experimental carriage. Nasal fluid, nasal mucosal, and blood samples will be taken before inoculation and on days 2, 7, 14, and 21 following inoculation to measure pneumococcal carriage density and identify immune correlates of protection from carriage. The vast majority of natural pneumococcal carriage events in PLHIV do not result in invasive disease and no invasive disease is expected in this study. However, robust participant safety monitoring is designed to identify signs of invasive disease early should they develop, and to implement treatment immediately. Participants will complete a Likert-style questionnaire at study-end to establish acceptability. Interpretations: We expect the EHPC model to be safely and acceptably implemented in PLHIV. The CHIM can then be used to accelerate pneumococcal vaccine evaluations in this population, and an evidence-based pneumococcal vaccination policy for PLHIV in sSA.
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Affiliation(s)
- Klara Doherty
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Dingase Dula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Anthony Chirwa
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Edna Nsomba
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Vitumbiko S. Nkhoma
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Neema Toto
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Tarsizio Chikaonda
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Raphael Kamng'ona
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Joseph Phiri
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Jesús Reiné
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Oxford Vaccine Group, University of Oxford, Oxford, England, UK
| | - John Ndaferankhande
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Lumbani Makhaza
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
| | - Peter Banda
- Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Kondwani Jambo
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Daniela M Ferreira
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Oxford Vaccine Group, University of Oxford, Oxford, England, UK
| | - Stephen B Gordon
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Southern Region, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
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Mazumdar D, Sarma A, Medhi D, Dutta R, Kataki M, Baishya L, Dutta BS, Saikia L. Capsular typing of Streptococcus pneumoniae isolated from clinical specimens in Gauhati Medical College and hospital, Assam, India. Indian J Med Microbiol 2023; 44:100350. [PMID: 37356826 DOI: 10.1016/j.ijmmb.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/21/2022] [Accepted: 01/16/2023] [Indexed: 06/27/2023]
Abstract
PURPOSE Streptococcus pneumoniae is an important human respiratory tract pathogen causing pneumococcal diseases in majority of children and adults. The capsule is a significant virulence factor of Pneumococci which determines the bacterial serotype and is the component used for synthesis of pneumococcal vaccines. This cross-sectional study aimed to isolate Streptococcus pneumoniae from clinical samples and determine the occurrence of its circulating serotypes in Assam, North East India. MATERIALS AND METHODS A total of 80 clinical samples were collected from June 2019 to May 2020 from patients clinically suspected from pneumococcal infection and also included samples routinely sent to bacteriology laboratory. Isolation and identification of S. pneumoniae was performed using conventional culture and molecular methods. Antibiotic susceptibility patterns were monitored. Capsular serotyping was performed using PCR of cpsA gene followed by DNA sequencing. RESULTS Majority of the cases suspected of pneumococcal infection belong to the paediatric group aged less than 5 years. Out of 80 samples, 10 (12.50%) were found to be positive by PCR of recP gene. Culture was positive in 80% (8/10) of the total positives. Co-trimoxazole resistance was seen in 33.33% of the isolate from sputum. Serotypes 6A, 6B, 6C and 19F were detected in our region, out of which 6C is a non-vaccine serotype. CONCLUSION Continued surveillance is needed to monitor trends in non-vaccine serotypes that may emerge as highly associated with antibiotic resistance. Also, the need to continuous monitoring of the antibiotic susceptibility of S. pneumoniae in North eastern parts of India is of outmost importance.
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Affiliation(s)
- Dikshita Mazumdar
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Anisha Sarma
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Devyashree Medhi
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Ridip Dutta
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Manjuri Kataki
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Lakshyasri Baishya
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Bornali Sharma Dutta
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
| | - Lahari Saikia
- Department of Microbiology, Gauhati Medical College & Hospital, Guwahati, 781032, Assam, India.
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Shekhar S, Brar NK, Petersen FC. Suppressive effect of therapeutic antibiotic regimen on antipneumococcal Th1/Th17 responses in neonatal mice. Pediatr Res 2023; 93:818-826. [PMID: 35778498 DOI: 10.1038/s41390-022-02115-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 04/21/2022] [Accepted: 05/02/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND Antibiotics are commonly used in human neonates, but their impact on neonatal T cell immunity remains poorly understood. The aim of this study was to investigate the impact of the antibiotic piperacillin with the beta-lactamase inhibitor tazobactam on neonatal CD4+ and CD8+ T cell responses to Streptococcus pneumoniae. METHODS Splenic and lung cells were isolated from the neonatal mice receiving piperacillin and tazobactam or saline (sham) and cultured with S. pneumoniae to analyze T cell cytokine production by ELISA and flow cytometry. RESULTS Antibiotic exposure to neonatal mice resulted in reduced numbers of CD4+/CD8+ T cells in the spleen and lungs compared to control mice. Upon in vitro stimulation with S. pneumoniae, splenocytes and lung cells from antibiotic-exposed mice produced lower levels of IFN-γ (Th1)/IL-17A (Th17) and IL-17A cytokines, respectively. Flow cytometric analysis revealed that S. pneumoniae-stimulated splenic CD4+ T cells from antibiotic-exposed mice expressed decreased levels of IFN-γ and IL-17A compared to control mice, whereas lung CD4+ T cells produced lower levels of IL-17A. However, no significant difference was observed for IL-4 (Th2) production. CONCLUSIONS Neonatal mice exposure to piperacillin and tazobactam reduces the number of CD4+ and CD8+ T cells, and suppresses Th1 and Th17, but not Th2, responses to S. pneumoniae. IMPACT Exposure of neonatal mice with a combination of piperacillin and tazobactam reduces CD4+/CD8+ T cells in the spleen and lungs. Antibiotic exposure suppresses neonatal Th1 and Th17, but not Th2, responses to Streptococcus pneumoniae. Our findings may have important implications for developing better therapeutic strategies in the neonatal intensive care unit.
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Affiliation(s)
| | - Navdeep K Brar
- Institute of Oral Biology, University of Oslo, Oslo, Norway
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Shekhar S, Brar NK, Håkansson AP, Petersen FC. Treatment of Mouse Infants with Amoxicillin, but Not the Human Milk-Derived Antimicrobial HAMLET, Impairs Lung Th17 Responses. Antibiotics (Basel) 2023; 12:antibiotics12020423. [PMID: 36830333 PMCID: PMC9952748 DOI: 10.3390/antibiotics12020423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/14/2023] [Accepted: 02/18/2023] [Indexed: 02/23/2023] Open
Abstract
Emerging evidence suggests differential effects of therapeutic antibiotics on infant T cell responses to pathogens. In this study, we explored the impact of the treatment of mouse infants with amoxicillin and the human milk-derived antimicrobial HAMLET (human alpha-lactalbumin made lethal to tumor cells) on T cell responses to Streptococcus pneumoniae. Lung cells and splenocytes were isolated from the infant mice subjected to intranasal administration of amoxicillin, HAMLET, or a combination of HAMLET and amoxicillin, and cultured with S. pneumoniae to measure T cell responses. After in-vitro stimulation with S. pneumoniae, lung cells from amoxicillin- or amoxicillin plus HAMLET-treated mice produced lower levels of Th17 (IL-17A), but not Th1 (IFN-γ), cytokine than mice receiving HAMLET or PBS. IL-17A/IFN-γ cytokine levels produced by the stimulated splenocytes, on the other hand, revealed no significant difference among treatment groups. Further analysis of T cell cytokine profiles by flow cytometry showed that lung CD4+, but not CD8+, T cells from amoxicillin- or HAMLET plus amoxicillin-treated mice expressed decreased levels of IL-17A compared to those from HAMLET-exposed or control mice. Collectively, these results indicate that exposure of infant mice to amoxicillin, but not HAMLET, may suppress lung Th17 responses to S. pneumoniae.
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Affiliation(s)
| | | | - Anders P. Håkansson
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University, 21428 Malmö, Sweden
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Host-Mediated Copper Stress Is Not Protective against Streptococcus pneumoniae D39 Infection. Microbiol Spectr 2022; 10:e0249522. [PMID: 36413018 PMCID: PMC9769658 DOI: 10.1128/spectrum.02495-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Metal ions are required by all organisms for the chemical processes that support life. However, in excess they can also exert toxicity within biological systems. During infection, bacterial pathogens such as Streptococcus pneumoniae are exposed to host-imposed metal intoxication, where the toxic properties of metals, such as copper, are exploited to aid in microbial clearance. However, previous studies investigating the antimicrobial efficacy of copper in vivo have reported variable findings. Here, we use a highly copper-sensitive strain of S. pneumoniae, lacking both copper efflux and intracellular copper buffering by glutathione, to investigate how copper stress is managed and where it is encountered during infection. We show that this strain exhibits highly dysregulated copper homeostasis, leading to the attenuation of growth and hyperaccumulation of copper in vitro. In a murine infection model, whole-tissue copper quantitation and elemental bioimaging of the murine lung revealed that infection with S. pneumoniae resulted in increased copper abundance in specific tissues, with the formation of spatially discrete copper hot spots throughout the lung. While the increased copper was able to reduce the viability of the highly copper-sensitive strain in a pneumonia model, copper levels in professional phagocytes and in a bacteremic model were insufficient to prosecute bacterial clearance. Collectively, this study reveals that host copper is redistributed to sites of infection and can impact bacterial viability in a hypersusceptible strain. However, in wild-type S. pneumoniae, the concerted actions of the copper homeostatic mechanisms are sufficient to facilitate continued viability and virulence of the pathogen. IMPORTANCE Streptococcus pneumoniae (the pneumococcus) is one of the world's foremost bacterial pathogens. Treatment of both localized and systemic pneumococcal infection is becoming complicated by increasing rates of multidrug resistance globally. Copper is a potent antimicrobial agent used by the mammalian immune system in the defense against bacterial pathogens. However, unlike other bacterial species, this copper stress is unable to prosecute pneumococcal clearance. This study determines how the mammalian host inflicts copper stress on S. pneumoniae and the bacterial copper tolerance mechanisms that contribute to maintenance of viability and virulence in vitro and in vivo. This work has provided insight into the chemical biology of the host-pneumococcal interaction and identified a potential avenue for novel antimicrobial development.
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Li H, Bradbury JA, Edin ML, Graves JP, Gruzdev A, Cheng J, Hoopes SL, DeGraff LM, Fessler MB, Garantziotis S, Schurman SH, Zeldin DC. sEH promotes macrophage phagocytosis and lung clearance of Streptococcus pneumoniae. J Clin Invest 2021; 131:129679. [PMID: 34591792 DOI: 10.1172/jci129679] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/28/2021] [Indexed: 12/12/2022] Open
Abstract
Epoxyeicosatrienoic acids (EETs) have potent antiinflammatory properties. Hydrolysis of EETs by soluble epoxide hydrolase/ epoxide hydrolase 2 (sEH/EPHX2) to less active diols attenuates their antiinflammatory effects. Macrophage activation is critical to many inflammatory responses; however, the role of EETs and sEH in regulating macrophage function remains unknown. Lung bacterial clearance of Streptococcus pneumoniae was impaired in Ephx2-deficient (Ephx2-/-) mice and in mice treated with an sEH inhibitor. The EET receptor antagonist EEZE restored lung clearance of S. pneumoniae in Ephx2-/- mice. Ephx2-/- mice had normal lung Il1b, Il6, and Tnfa expression levels and macrophage recruitment to the lungs during S. pneumoniae infection; however, Ephx2 disruption attenuated proinflammatory cytokine induction, Tlr2 and Pgylrp1 receptor upregulation, and Ras-related C3 botulinum toxin substrates 1 and 2 (Rac1/2) and cell division control protein 42 homolog (Cdc42) activation in PGN-stimulated macrophages. Consistent with these observations, Ephx2-/- macrophages displayed reduced phagocytosis of S. pneumoniae in vivo and in vitro. Heterologous overexpression of TLR2 and peptidoglycan recognition protein 1 (PGLYRP1) in Ephx2-/- macrophages restored macrophage activation and phagocytosis. Human macrophage function was similarly regulated by EETs. Together, these results demonstrate that EETs reduced macrophage activation and phagocytosis of S. pneumoniae through the downregulation of TLR2 and PGLYRP1 expression. Defining the role of EETs and sEH in macrophage function may lead to the development of new therapeutic approaches for bacterial diseases.
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Broadly Reactive Human Monoclonal Antibodies Targeting the Pneumococcal Histidine Triad Protein Protect against Fatal Pneumococcal Infection. Infect Immun 2021; 89:IAI.00747-20. [PMID: 33649050 PMCID: PMC8091081 DOI: 10.1128/iai.00747-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/21/2021] [Indexed: 02/07/2023] Open
Abstract
Streptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most serotypes included in vaccines, a rise in infection due to nonvaccine serotypes and moderate efficacy against some vaccine serotypes have contributed to high disease incidence. Streptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most serotypes included in vaccines, a rise in infection due to nonvaccine serotypes and moderate efficacy against some vaccine serotypes have contributed to high disease incidence. Additionally, numerous isolates of S. pneumoniae are antibiotic or multidrug resistant. Several conserved pneumococcal proteins prevalent in the majority of serotypes have been examined for their potential as vaccines in preclinical and clinical trials. An additional, yet-unexplored tool for disease prevention and treatment is the use of human monoclonal antibodies (MAbs) targeting conserved pneumococcal proteins. Here, we isolated the first human MAbs (PhtD3, PhtD6, PhtD7, PhtD8, and PspA16) against the pneumococcal histidine triad protein (PhtD) and the pneumococcal surface protein A (PspA), two conserved and protective antigens. MAbs to PhtD target diverse epitopes on PhtD, and MAb PspA16 targets the N-terminal segment of PspA. The PhtD-specific MAbs bind to multiple serotypes, while MAb PspA16 serotype breadth is limited. MAbs PhtD3 and PhtD8 prolong the survival of mice infected with pneumococcal serotype 3. Furthermore, MAb PhtD3 prolongs the survival of mice in intranasal and intravenous infection models with pneumococcal serotype 4 and in mice infected with pneumococcal serotype 3 when administered 24 h after pneumococcal infection. All PhtD and PspA MAbs demonstrate opsonophagocytic activity, suggesting a potential mechanism of protection. Our results identify new human MAbs for pneumococcal disease prevention and treatment and identify epitopes on PhtD and PspA recognized by human B cells.
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Morton B, Jambo K, Chikaonda T, Rylance J, Henrion MY, Banda NP, Nsomba E, Gondwe J, Ferreira D, Gordon SB. The influence of pneumococcal conjugate vaccine-13 on nasal colonisation in a controlled human infection model of pneumococcal carriage in Malawi: a double-blinded randomised controlled trial protocol. Wellcome Open Res 2021; 6:240. [PMID: 36263101 PMCID: PMC9549377.2 DOI: 10.12688/wellcomeopenres.17172.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2022] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement, and demonstrate reduced effectiveness against mucosal colonisation. For Malawi, nasopharyngeal carriage of vaccine-type pneumococci is common in vaccinated children despite national roll-out of 13-valent pneumococcal conjugate vaccine (PCV13) since 2011. Our team has safely transferred an established experimental human pneumococcal carriage method from Liverpool School of Tropical Medicine to the Malawi-Liverpool Wellcome Trust Clinical Research Programme, Malawi. This study will determine potential immunological mechanisms for the differential effects of PCV13 on nasal carriage between healthy Malawian and UK populations. We will conduct a double-blinded randomised controlled trial to vaccinate (1:1) participants with either PCV13 or control (normal saline). After a period of one month, participants will be inoculated with S. pneumoniae serotype 6B to experimentally induce nasal carriage using the EHPC method. Subsequently, participants will be invited for a second inoculation after one year to determine longer-term vaccine-induced immunological effects. Primary endpoint: detection of inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: local and systemic innate, humoral and cellular responses to PCV-13 with and without pneumococcal nasal carriage The primary objective of this controlled human infection model study is to determine if PCV-13 vaccination is protective against pneumococcal carriage in healthy adult Malawian volunteers. This study will help us to understand the observed differences in PCV-13 efficacy between populations and inform the design of future vaccines relevant to the Malawian population. Trial Registration: Pan African Clinical Trial Registry (REF: PACTR202008503507113).
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Affiliation(s)
- Ben Morton
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Critical Care Medicine, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Kondwani Jambo
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Tarsizio Chikaonda
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jamie Rylance
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Marc Y.R. Henrion
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ndaziona Peter Banda
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
- College of Medicine, Malawi, Blantyre, Malawi
| | - Edna Nsomba
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Joel Gondwe
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Daniela Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Stephen B. Gordon
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
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Morton B, Jambo K, Chikaonda T, Rylance J, Henrion MY, Banda NP, Nsomba E, Gondwe J, Ferreira D, Gordon SB. The influence of pneumococcal conjugate vaccine-13 on nasal colonisation in a controlled human infection model of pneumococcal carriage in Malawi: a double-blinded randomised controlled trial protocol. Wellcome Open Res 2021; 6:240. [PMID: 36263101 PMCID: PMC9549377 DOI: 10.12688/wellcomeopenres.17172.1] [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] [Accepted: 08/31/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement, and demonstrate reduced effectiveness against mucosal colonisation. For Malawi, nasopharyngeal carriage of vaccine-type pneumococci is common in vaccinated children despite national roll-out of 13-valent pneumococcal conjugate vaccine (PCV13) since 2011. Our team has safely transferred an established experimental human pneumococcal carriage method from Liverpool School of Tropical Medicine to the Malawi-Liverpool Wellcome Trust Clinical Research Programme, Malawi. This study will determine potential immunological mechanisms for the differential effects of PCV13 on nasal carriage between healthy Malawian and UK populations. We will conduct a double-blinded randomised controlled trial to vaccinate (1:1) participants with either PCV13 or control (normal saline). After a period of one month, participants will be inoculated with S. pneumoniae serotype 6B to experimentally induce nasal carriage using the EHPC method. Subsequently, participants will be invited for a second inoculation after one year to determine longer-term vaccine-induced immunological effects. Primary endpoint: detection of inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: local and systemic innate, humoral and cellular responses to PCV-13 with and without pneumococcal nasal carriage The primary objective of this controlled human infection model study is to determine if PCV-13 vaccination is protective against pneumococcal carriage in healthy adult Malawian volunteers. This study will help us to understand the observed differences in PCV-13 efficacy between populations and inform the design of future vaccines relevant to the Malawian population. Trial Registration: Pan African Clinical Trial Registry (REF: PACTR202008503507113).
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Affiliation(s)
- Ben Morton
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Critical Care Medicine, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Kondwani Jambo
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Tarsizio Chikaonda
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Jamie Rylance
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Marc Y.R. Henrion
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Ndaziona Peter Banda
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
- College of Medicine, Malawi, Blantyre, Malawi
| | - Edna Nsomba
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Joel Gondwe
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Daniela Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Stephen B. Gordon
- Lung Health, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, Malawi
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11
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Kapumba BM, Jambo K, Rylance J, Gmeiner M, Sambakunsi R, Parker M, Gordon SB, Gooding K. Stakeholder views on the acceptability of human infection studies in Malawi. BMC Med Ethics 2020; 21:14. [PMID: 32024497 PMCID: PMC7003337 DOI: 10.1186/s12910-020-0454-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 01/28/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Human infection studies (HIS) are valuable in vaccine development. Deliberate infection, however, creates challenging questions, particularly in low and middle-income countries (LMICs) where HIS are new and ethical challenges may be heightened. Consultation with stakeholders is needed to support contextually appropriate and acceptable study design. We examined stakeholder perceptions about the acceptability and ethics of HIS in Malawi, to inform decisions about planned pneumococcal challenge research and wider understanding of HIS ethics in LMICs. METHODS We conducted 6 deliberative focus groups and 15 follow-up interviews with research staff, medical students, and community representatives from rural and urban Blantyre. We also conducted 5 key informant interviews with clinicians, ethics committee members, and district health government officials. RESULTS Stakeholders perceived HIS research to have potential population health benefits, but they also had concerns, particularly related to the safety of volunteers and negative community reactions. Acceptability depended on a range of conditions related to procedures for voluntary and informed consent, inclusion criteria, medical care or support, compensation, regulation, and robust community engagement. These conditions largely mirror those in existing guidelines for HIS and biomedical research in LMICs. Stakeholder perceptions pointed to potential tensions, for example, balancing equity, safety, and relevance in inclusion criteria. CONCLUSIONS Our findings suggest HIS research could be acceptable in Malawi, provided certain conditions are in place. Ongoing assessment of participant experiences and stakeholder perceptions will be required to strengthen HIS research during development and roll-out.
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Affiliation(s)
- Blessings M Kapumba
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi.
| | - Kondwani Jambo
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jamie Rylance
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Markus Gmeiner
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Rodrick Sambakunsi
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
| | - Michael Parker
- Wellcome Centre for Ethics and Humanities and Ethox Centre, University of Oxford, Oxford, UK
| | - Stephen B Gordon
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Kate Gooding
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, P.O. Box 30096, Chichiri, Blantyre, 3, Malawi
- Liverpool School of Tropical Medicine, Liverpool, UK
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12
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Jain S, Das BK, Mahajan N, Kapil A, Chaudhry R, Sood S, Kabra SK, Dwivedi SN. Molecular capsular typing and multi locus sequence typing of invasive, non-invasive and commensal Streptococcus pneumoniae isolates from North India. Indian J Med Microbiol 2020; 38:78-86. [PMID: 32719213 DOI: 10.4103/ijmm.ijmm_20_111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Purpose The purpose of this study is to determine the antimicrobial susceptibility pattern, serotype distribution and sequence type (ST) of Streptococcus pneumoniae isolates from invasive and non-invasive infection and correlate it with isolates from commensal nasopharyngeal flora to ascertain their role in infection. Materials and Methods S. pneumoniae isolates from blood, cerebrospinal fluid, pleural fluid and respiratory secretions (sputum, bronchoalveolar lavage and nasopharyngeal swab/throat swab) were analysed to determine ST, serotype and antimicrobial susceptibility pattern. Serotyping was performed by multiplex polymerase chain reactions as well as by quellung reaction. Antimicrobial susceptibility testing was determined using Kirby Bauer's disc diffusion method as per the Clinical Laboratory Standards Institute guidelines. Minimum inhibitory concentration was determined using E-test for penicillin. Multilocus sequence typing (MLST) was done to understand genetic relatedness and evolutionary relationship among strains. Results A total of 125 S. pneumoniae isolates were collected, including 25 from invasive pneumococcal disease, 25 from non-invasive and 75 from nasopharyngeal swab of healthy children (Commensal). Resistance to penicillin, erythromycin, and co-trimoxazole was observed in 14.4%, 12% and 81.6% of the isolates, respectively, by KirbyBauer's disc diffusion method. Serotype 14 was found to be the most prevalent in invasive and non-invasive isolates, while serotype 6 was the most common in commensal isolates. New STs were found among invasive (ST13826, ST13827), non-invasive (ST13823, ST13824, and ST13961) and commensal (ST13825) isolates. Conclusion MLST sequence analysis shows that invasive isolates were found to be clustered with non-invasive and commensal isolates. Analysis of MLST suggests the possibility of genetic relatedness and exchange of genetic material between invasive, non-invasive and commensal isolates.
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Affiliation(s)
- Shefali Jain
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Bimal Kumar Das
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Neeraj Mahajan
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Arti Kapil
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Rama Chaudhry
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Seema Sood
- Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
| | - Sushil Kumar Kabra
- Department of Paediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Sada Nand Dwivedi
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India
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13
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Morton B, Burr S, Jambo K, Rylance J, Henrion MY, Banda NP, Nsomba E, Kapumba B, Manda-Taylor L, Masesa C, Ferrreira D, Gordon SB. A pneumococcal controlled human infection model in Malawi: Transfer of an established pneumococcal carriage model from Liverpool, UK to Blantyre, Malawi - A feasibility study. Wellcome Open Res 2020; 5:25. [PMID: 32399498 PMCID: PMC7194502 DOI: 10.12688/wellcomeopenres.15689.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement and demonstrate reduced effectiveness against mucosal colonisation. As asymptomatic colonisation of the human nasopharynx is a prerequisite for pneumococcal disease, this is proposed as a marker for novel vaccine efficacy. Our team established a safe and reproducible pneumococcal controlled human infection model at Liverpool School of Tropical Medicine (LSTM). This has been used to test vaccine induced protection against nasopharyngeal carriage for ten years in over 1000 participants. We will transfer established standardised operating procedures from LSTM to Malawi and test in up to 36 healthy participants. Primary endpoint: detection of the inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: confirmation of robust clinical and laboratory methods for sample capture and processing. Tertiary endpoints: participant acceptability of study and methods. We will test three doses of pneumococcal inoculation (20,000, 80,000 and 160,000 colony forming units [CFUs] per naris) using a parsimonious study design intended to reduce unnecessary exposure to participants. We hypothesise that 80,000 CFUs will induce nasal colonisation in approximately half of participants per established LSTM practice. The aims of the feasibility study are: 1) Establish Streptococcus pneumoniae experimental human pneumococcal carriage in Malawi; 2) Confirm optimal nasopharyngeal pneumococcal challenge dose; 3) Confirm safety and measure potential symptoms; 4) Confirm sampling protocols and laboratory assays; 5) Assess feasibility and acceptability of consent and study procedures. Confirmation of pneumococcal controlled human infection model feasibility in Malawi will enable us to target pneumococcal vaccine candidates for an at-risk population who stand the most to gain from new and improved vaccine strategies.
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Affiliation(s)
- Ben Morton
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Critical Care Medicine, Liverpool University Hospitals NHS Foundation Trust, Liverpool, L9 7AL, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Sarah Burr
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Kondwani Jambo
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Jamie Rylance
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Marc Y.R. Henrion
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Ndaziona Peter Banda
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
- University of Malawi College of Medicine, Blantyre, Malawi
| | - Edna Nsomba
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Blessings Kapumba
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
| | - Lucinda Manda-Taylor
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- University of Malawi College of Medicine, Blantyre, Malawi
| | - Clemens Masesa
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Daniela Ferrreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Stephen B. Gordon
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
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14
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Morton B, Burr S, Jambo K, Rylance J, Henrion MY, Banda NP, Nsomba E, Kapumba B, Manda-Taylor L, Masesa C, Ferrreira D, Gordon SB. A pneumococcal controlled human infection model in Malawi: Transfer of an established pneumococcal carriage model from Liverpool, UK to Blantyre, Malawi - A feasibility study. Wellcome Open Res 2020; 5:25. [PMID: 32399498 PMCID: PMC7194502 DOI: 10.12688/wellcomeopenres.15689.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2020] [Indexed: 01/30/2023] Open
Abstract
Streptococcus pneumoniae is the leading cause of morbidity and mortality due to community acquired pneumonia, bacterial meningitis and bacteraemia worldwide. Pneumococcal conjugate vaccines protect against invasive disease, but are expensive to manufacture, limited in serotype coverage, associated with serotype replacement and demonstrate reduced effectiveness against mucosal colonisation. As asymptomatic colonisation of the human nasopharynx is a prerequisite for pneumococcal disease, this is proposed as a marker for novel vaccine efficacy. Our team established a safe and reproducible pneumococcal controlled human infection model at Liverpool School of Tropical Medicine (LSTM). This has been used to test vaccine induced protection against nasopharyngeal carriage for ten years in over 1000 participants. We will transfer established standardised operating procedures from LSTM to Malawi and test in up to 36 healthy participants. Primary endpoint: detection of the inoculated pneumococci by classical culture from nasal wash recovered from the participants after pneumococcal challenge. Secondary endpoints: confirmation of robust clinical and laboratory methods for sample capture and processing. Tertiary endpoints: participant acceptability of study and methods. We will test three doses of pneumococcal inoculation (20,000, 80,000 and 160,000 colony forming units [CFUs] per naris) using a parsimonious study design intended to reduce unnecessary exposure to participants. We hypothesise that 80,000 CFUs will induce nasal colonisation in approximately half of participants per established LSTM practice. The aims of the feasibility study are: 1) Establish Streptococcus pneumoniae experimental human pneumococcal carriage in Malawi; 2) Confirm optimal nasopharyngeal pneumococcal challenge dose; 3) Confirm safety and measure potential symptoms; 4) Confirm sampling protocols and laboratory assays; 5) Assess feasibility and acceptability of consent and study procedures. Confirmation of pneumococcal controlled human infection model feasibility in Malawi will enable us to target pneumococcal vaccine candidates for an at-risk population who stand the most to gain from new and improved vaccine strategies.
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Affiliation(s)
- Ben Morton
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Critical Care Medicine, Liverpool University Hospitals NHS Foundation Trust, Liverpool, L9 7AL, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Sarah Burr
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Kondwani Jambo
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Jamie Rylance
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Marc Y.R. Henrion
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Ndaziona Peter Banda
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
- University of Malawi College of Medicine, Blantyre, Malawi
| | - Edna Nsomba
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
| | - Blessings Kapumba
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
| | - Lucinda Manda-Taylor
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- University of Malawi College of Medicine, Blantyre, Malawi
| | - Clemens Masesa
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Daniela Ferrreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Stephen B. Gordon
- Lung Health Group, Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre, PO Box 30096, Malawi
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Department of Medicine, Queen Elizabeth Central Hospital, Blantyre, PO Box 95, UK
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15
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Lourenço J, Obolski U, Swarthout TD, Gori A, Bar-Zeev N, Everett D, Kamng'ona AW, Mwalukomo TS, Mataya AA, Mwansambo C, Banda M, Gupta S, French N, Heyderman RS. Determinants of high residual post-PCV13 pneumococcal vaccine-type carriage in Blantyre, Malawi: a modelling study. BMC Med 2019; 17:219. [PMID: 31801542 PMCID: PMC6894346 DOI: 10.1186/s12916-019-1450-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/24/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND In November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to 7 years after introduction (2015-2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in high-income countries, and impact was asymmetric across age groups. METHODS A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage. RESULTS Accumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49-82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0-9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02-81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection. CONCLUSIONS There are both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by an age-specific, local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact on carriage (and therefore herd protection) has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.
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Affiliation(s)
- J Lourenço
- Department of Zoology, University of Oxford, Oxford, UK.
| | - U Obolski
- School of Public Health, Tel Aviv University, Tel Aviv, Israel.,Porter School of the Environment and Earth Sciences, Tel Aviv University, Tel Aviv, Israel
| | - T D Swarthout
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - A Gori
- NIHR Mucosal Pathogens Research Unit, Division of Infection & Immunity, University College London, London, UK
| | - N Bar-Zeev
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - D Everett
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,The Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - A W Kamng'ona
- Department of Biomedical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - T S Mwalukomo
- Department of Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - A A Mataya
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | - M Banda
- Ministry of Education, Blantyre, Malawi
| | - S Gupta
- Department of Zoology, University of Oxford, Oxford, UK
| | - N French
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Centre for Global Vaccine Research, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - R S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,NIHR Mucosal Pathogens Research Unit, Division of Infection & Immunity, University College London, London, UK
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16
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Kim JY, Seo SM, Lee HK, Kim HW, Choi YK. Comparison of the virulence of Streptococcus pneumoniae in ICR mouse stocks of three different origins. Lab Anim Res 2019; 35:5. [PMID: 31463224 PMCID: PMC6707427 DOI: 10.1186/s42826-019-0002-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/11/2019] [Indexed: 01/13/2023] Open
Abstract
Streptococcus pneumoniae causes many people to suffer from pneumonia, septicemia, and other diseases worldwide. To identify the difference in susceptibility of and treatment efficacy against S. pneumoniae in three ICR mouse stocks (Korl:ICR, A:ICR, and B:ICR) with different origins, mice were infected with 2 × 106, 2 × 107, and 2 × 108 CFU of S. pneumoniae D39 intratracheally. The survival of mice was observed until three weeks after the infection. The three stocks of mice showed no significant survival rate difference at 2 × 106 and 2 × 107 CFU. However, the lung and spleen weight in the A:ICR stock was significantly different from that in the other two stocks, whereas the liver weight in B:ICR stock was significantly lower than that in the other two stocks. Interestingly, no significant CFU difference in the organs was observed between the ICR stocks. The level of interferon gamma inducible protein 10 in Korl:ICR was significantly lower than that in the other two stocks. The level of granulocyte colony stimulating factor in B:ICR was significantly lower than in the other two stocks. However, tumor-necrosis factor-alpha and interleukin-6 levels showed no significant difference between the ICR stocks. In the vancomycin efficacy test after the S. pneumoniae infection, both the single-dose and double-dose vancomycin-treated groups showed a significantly better survival rate than the control group. There was no significant survival difference between the three stocks. These data showed that Korl:ICR, A:ICR, and B:ICR have no susceptibility difference to the S. pneumoniae D39 serotype 2.
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Affiliation(s)
- Jun-Young Kim
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029 Republic of Korea
| | - Sun-Min Seo
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029 Republic of Korea
| | - Han-Kyul Lee
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029 Republic of Korea
| | - Han-Woong Kim
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029 Republic of Korea
| | - Yang-Kyu Choi
- Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029 Republic of Korea
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17
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Jehan F, Nisar I, Kerai S, Brown N, Ambler G, Zaidi AKM. Should fast breathing pneumonia cases be treated with antibiotics? The scientific rationale for revisiting management in Low and Middle income countries. Int J Infect Dis 2019; 85:64-66. [PMID: 31176034 PMCID: PMC6669273 DOI: 10.1016/j.ijid.2019.05.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 01/10/2023] Open
Abstract
World Health Organization (WHO) recommends oral antibiotic treatment for all children with fast breathing pneumonia. However evidence for the guidance is weak and infections are often viral and self-limiting. Further information regarding the true rationale for conducting non-inferiority trials to test the hypothesis that antibiotics may not be necessary for children with fast breathing as the sole symptomatology.
Background Pneumonia is the largest single contributor to child mortality and the problem is more acute in low and middle income countries. The World Health Organization (WHO) currently recommends oral antibiotic treatment for all children with fast breathing pneumonia without danger signs. It is, however, widely acknowledged that most such infections are viral and self-limiting and that the evidence for the guidance is weak. Rationale Overuse of antibiotics exposes children to adverse events, increases cost for families, burdens already stretched health care resources and may contribute to development of antibiotic resistance. Conclusion There is equipoise regarding utility of antibiotic in case of fast breathing pneumonia and no high quality trial evidence exists. This paper provides further information behind the rationale for conducting non-inferiority trials to test the hypothesis that antibiotics may not be necessary for children with fast breathing as the sole symptomatology.
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Affiliation(s)
- Fyezah Jehan
- Department of Paediatrics and Child Health, Aga Khan University, Pakistan.
| | - Imran Nisar
- Department of Paediatrics and Child Health, Aga Khan University, Pakistan.
| | - Salima Kerai
- Department of Paediatrics and Child Health, Aga Khan University, Pakistan.
| | - Nick Brown
- Department of Paediatrics and Child Health, Aga Khan University, Pakistan; International Maternal and Child Health (IMCH), Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden; Department of Paediatrics, Länssjukhuset Gävle-Sandviken, Gävle, Sweden.
| | | | - Anita K M Zaidi
- Department of Paediatrics and Child Health, Aga Khan University, Pakistan.
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Stark AK, Chandra A, Chakraborty K, Alam R, Carbonaro V, Clark J, Sriskantharajah S, Bradley G, Richter AG, Banham-Hall E, Clatworthy MR, Nejentsev S, Hamblin JN, Hessel EM, Condliffe AM, Okkenhaug K. PI3Kδ hyper-activation promotes development of B cells that exacerbate Streptococcus pneumoniae infection in an antibody-independent manner. Nat Commun 2018; 9:3174. [PMID: 30093657 PMCID: PMC6085315 DOI: 10.1038/s41467-018-05674-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 07/17/2018] [Indexed: 02/02/2023] Open
Abstract
Streptococcus pneumoniae is a major cause of pneumonia and a leading cause of death world-wide. Antibody-mediated immune responses can confer protection against repeated exposure to S. pneumoniae, yet vaccines offer only partial protection. Patients with Activated PI3Kδ Syndrome (APDS) are highly susceptible to S. pneumoniae. We generated a conditional knock-in mouse model of this disease and identify a CD19+B220- B cell subset that is induced by PI3Kδ signaling, resides in the lungs, and is correlated with increased susceptibility to S. pneumoniae during early phases of infection via an antibody-independent mechanism. We show that an inhaled PI3Kδ inhibitor improves survival rates following S. pneumoniae infection in wild-type mice and in mice with activated PI3Kδ. These results suggest that a subset of B cells in the lung can promote the severity of S. pneumoniae infection, representing a potential therapeutic target.
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Affiliation(s)
- Anne-Katrien Stark
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
- Division of Immunology, Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Anita Chandra
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
- Division of Immunology, Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK
- Department of Medicine, University of Cambridge, Cambridge, CB2 OQQ, UK
- Cambridge University Hospitals NHS Trust, Hills Road, Cambridge, CB2 0QQ, UK
| | - Krishnendu Chakraborty
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
- Department of Medicine, University of Cambridge, Cambridge, CB2 OQQ, UK
| | - Rafeah Alam
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
| | - Valentina Carbonaro
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
| | - Jonathan Clark
- Biological Chemistry Laboratory, Babraham Institute, Cambridge, CB21 3AT, UK
| | - Srividya Sriskantharajah
- Refractory Respiratory Inflammation Discovery Performance Unit, Respiratory Therapy Area, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | - Glyn Bradley
- Computational Biology and Statistics, Target Sciences, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | - Alex G Richter
- Department of Immunology, Queen Elizabeth Hospital, Birmingham, B15 2TH, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
| | - Edward Banham-Hall
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK
- Department of Medicine, University of Cambridge, Cambridge, CB2 OQQ, UK
- Cambridge University Hospitals NHS Trust, Hills Road, Cambridge, CB2 0QQ, UK
| | - Menna R Clatworthy
- Molecular Immunity Unit, MRC Laboratory of Molecular Biology, University of Cambridge Department of Medicine, MRC Laboratory of Molecular Biology, Cambridge, CB2 OQQ, UK
| | - Sergey Nejentsev
- Department of Medicine, University of Cambridge, Cambridge, CB2 OQQ, UK
| | - J Nicole Hamblin
- Refractory Respiratory Inflammation Discovery Performance Unit, Respiratory Therapy Area, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | - Edith M Hessel
- Refractory Respiratory Inflammation Discovery Performance Unit, Respiratory Therapy Area, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | - Alison M Condliffe
- Department of Infection, Immunity and Cardiovascular Diseases, University of Sheffield, Sheffield, S10 2RX, UK
| | - Klaus Okkenhaug
- Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, CB21 3AT, UK.
- Division of Immunology, Department of Pathology, University of Cambridge, Cambridge, CB2 1QP, UK.
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19
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Molecular detection of genes responsible for macrolide resistance among Streptococcus pneumoniae isolated in North Lebanon. J Infect Public Health 2017; 10:745-748. [DOI: 10.1016/j.jiph.2016.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 10/10/2016] [Accepted: 11/18/2016] [Indexed: 11/23/2022] Open
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Molecular Mechanisms of the Binding and Specificity of Streptococcus Pneumoniae Sortase C Enzymes for Pilin Subunits. Sci Rep 2017; 7:13119. [PMID: 29030637 PMCID: PMC5640630 DOI: 10.1038/s41598-017-13135-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 09/19/2017] [Indexed: 02/05/2023] Open
Abstract
Pili are elongated structures that protrude from bacteria and increase their virulence. The Streptococcus pnuenomae pilus island 1 pili are composed of three subunits, RrgA, RrgB, and RrgC, and are assembled by three class C sortase C (SrtC) enzymes: SrtC-1, SrtC-2, and SrtC-3. Pilin subunits are recognized by SrtC proteins through a pentapeptide sorting signal, and while previous studies have sought to characterize the selectivities of SrtC isoforms for these subunits, the molecular mechanisms underlying these interactions remain unclear. Here, we report a series of molecular dynamics simulations of each SrtC enzyme with the sorting signals of RrgA, RrgB, and RrgC to determine the structural and thermodynamic basis of pilin recognition. Results show that, in accordance with previous studies, both SrtC-1 and SrtC-3 are selective for RrgB, while SrtC-2 is selective for RrgA. This specificity is tuned by the sorting signal binding conformation in which the first two residue sidechains complement hydrophobic residues around the active site, while the third residue projects away from the catalytic triad and makes specific interactions based on its charge and reach. Together, these results provided atomic-scale descriptions of the SrtC substrate selectivity mechanisms and extend the emerging model of pilin construction in S. pnuenomae.
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Naturally Acquired Human Immunity to Pneumococcus Is Dependent on Antibody to Protein Antigens. PLoS Pathog 2017; 13:e1006137. [PMID: 28135322 PMCID: PMC5279798 DOI: 10.1371/journal.ppat.1006137] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 12/17/2016] [Indexed: 12/31/2022] Open
Abstract
Naturally acquired immunity against invasive pneumococcal disease (IPD) is thought to be dependent on anti-capsular antibody. However nasopharyngeal colonisation by Streptococcus pneumoniae also induces antibody to protein antigens that could be protective. We have used human intravenous immunoglobulin preparation (IVIG), representing natural IgG responses to S. pneumoniae, to identify the classes of antigens that are functionally relevant for immunity to IPD. IgG in IVIG recognised capsular antigen and multiple S. pneumoniae protein antigens, with highly conserved patterns between different geographical sources of pooled human IgG. Incubation of S. pneumoniae in IVIG resulted in IgG binding to the bacteria, formation of bacterial aggregates, and enhanced phagocytosis even for unencapsulated S. pneumoniae strains, demonstrating the capsule was unlikely to be the dominant protective antigen. IgG binding to S. pneumoniae incubated in IVIG was reduced after partial chemical or genetic removal of bacterial surface proteins, and increased against a Streptococcus mitis strain expressing the S. pneumoniae protein PspC. In contrast, depletion of type-specific capsular antibody from IVIG did not affect IgG binding, opsonophagocytosis, or protection by passive vaccination against IPD in murine models. These results demonstrate that naturally acquired protection against IPD largely depends on antibody to protein antigens rather than the capsule. Streptococcus pneumoniae is a major global killer. Invasive pneumococcal disease (IPD) is the most severe form of infection. Surprisingly, the natural mechanisms of immunity to IPD in healthy individuals are unclear. The success of vaccines stimulating anti-capsular antibodies have led to the belief that the same mechanism lies behind natural protection. Using studies with pooled human immunoglobulin, we demonstrate that this is not the case and instead IgG recognising the bacterial surface proteins appears to have the dominant functional role. This finding supports efforts towards protein antigen-based vaccines, and opens the possibility of stratifying potential risk for individuals of IPD.
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22
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Saha S, Hasan M, Kim L, Farrar JL, Hossain B, Islam M, Ahmed ANU, Amin MR, Hanif M, Hussain M, El-Arifeen S, Whitney CG, Saha SK. Epidemiology and risk factors for pneumonia severity and mortality in Bangladeshi children <5 years of age before 10-valent pneumococcal conjugate vaccine introduction. BMC Public Health 2016; 16:1233. [PMID: 27927201 PMCID: PMC5142317 DOI: 10.1186/s12889-016-3897-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 12/01/2016] [Indexed: 02/03/2023] Open
Abstract
Background Pneumonia is the leading infectious cause of morbidity and mortality in young children in Bangladesh. We present the epidemiology of pneumonia in Bangladeshi children <5 years before 10-valent pneumococcal conjugate vaccine introduction and investigate factors associated with disease severity and mortality. Methods Children aged 2–59 months admitted to three Bangladeshi hospitals with pneumonia (i.e., cough or difficulty breathing and age-specific tachypnea without danger signs) or severe pneumonia (i.e., cough or difficulty breathing and ≥1 danger signs) were included. Demographic, clinical, laboratory, and vaccine history data were collected. We assessed associations between characteristics and pneumonia severity and mortality using multivariable logistic regression. Results Among 3639 Bangladeshi children with pneumonia, 61% had severe disease, and 2% died. Factors independently associated with severe pneumonia included ages 2–5 months (adjusted odds ratio [aOR] 1.60 [95% CI: 1.26–2.01]) and 6–11 months (aOR 1.31 [1.10–1.56]) relative to 12–59 months, low weight for age (aOR 1.22 [1.04–1.42]), unsafe drinking water source (aOR 2.00 [1.50–2.69]), higher paternal education (aOR 1.34 [1.15–1.57]), higher maternal education (aOR 0.74 [0.64–0.87]), and being fully vaccinated for age with pentavalent vaccination (aOR 0.64 [0.51–0.82]). Increased risk of pneumonia mortality was associated with age <12 months, low weight for age, unsafe drinking water source, lower paternal education, disease severity, and having ≥1 co-morbid condition. Conclusions Modifiable factors for severe pneumonia and mortality included low weight for age and access to safe drinking water. Improving vaccination status could decrease disease severity.
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Affiliation(s)
- Shampa Saha
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Md Hasan
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Lindsay Kim
- , 1600 Clifton Road, NE, MS A34, Atlanta, GA, 30329, USA
| | | | - Belal Hossain
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Maksuda Islam
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Asm Nawshad Uddin Ahmed
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - M Ruhul Amin
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Mohammed Hanif
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Manzoor Hussain
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Shams El-Arifeen
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh.,International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, 1212, Bangladesh
| | | | - Samir K Saha
- Child Health research Foundation, Dhaka Shishu Hospital, Sher-E Bangla Nagar, Dhaka, 1207, Bangladesh. .,Department of Microbiology, Bangladesh Institute of Child Health, Dhaka Shishu Hospital, Dhaka, 1207, Bangladesh.
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Elshafie S, Taj-Aldeen SJ. Emerging resistant serotypes of invasive Streptococcus pneumoniae. Infect Drug Resist 2016; 9:153-60. [PMID: 27418844 PMCID: PMC4935045 DOI: 10.2147/idr.s102410] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7). METHODS A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. RESULTS The most common serotypes for all age groups were 3 (12.70%), 14 (11.90%), 1 (11.90%), 19A (9.00%), 9V (5.20%), 23F (5.20%), and 19F (4.50%). Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10), and the 13-valent conjugated vaccine (PCV-13) were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2-5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6-64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46%) were multidrug resistant (MDR) and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in cefotaxime nonsusceptible strains from 3.55% to 16.66%. CONCLUSION Invasive pneumococcal strains and the emergence of MDR serotypes is a global burden that must be addressed through multiple strategies, including vaccination, antibiotic stewardship, and continuous surveillance.
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Affiliation(s)
- Sittana Elshafie
- Qatar Orthopedic and Sports Medicine Hospital, Aspetar, Doha, Qatar
- Weill Cornell Medicine-Qatar
| | - Saad J Taj-Aldeen
- Weill Cornell Medicine-Qatar
- Department of Laboratory Medicine and Pathology, Microbiology Division, Hamad Medical Corporation, Doha, Qatar
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Epidemiology of Invasive Pneumococcal Disease in Bangladeshi Children Before Introduction of Pneumococcal Conjugate Vaccine. Pediatr Infect Dis J 2016; 35:655-61. [PMID: 26658530 DOI: 10.1097/inf.0000000000001037] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Because Bangladesh intended to introduce pneumococcal conjugate vaccine (PCV)-10 in 2015, we examined the baseline burden of invasive pneumococcal disease (IPD) to measure impact of PCV. METHODS During 2007-2013, we performed blood and cerebrospinal fluid cultures in children <5 years old with suspected IPD identified through active surveillance at 4 hospitals. Isolates were serotyped by quellung and tested for antibiotic susceptibility by disc diffusion and E-test. Serotyping of culture-negative cases, detected by Binax or polymerase chain reaction, was done by sequential multiplex polymerase chain reaction. Trends in IPD case numbers were analyzed by serotype and clinical syndrome. RESULTS The study identified 752 IPD cases; 78% occurred in children <12 months old. Serotype information was available for 78% (442/568), including 197 of 323 culture-negative cases available for serotyping. We identified 50 serotypes; the most common serotypes were 2 (16%), 1 (10 %), 6B (7%), 14 (7%) and 5 (7%). PCV-10 and PCV-13 serotypes accounted for 46% (range 29%-57% by year) and 50% (range 37%-64% by year) of cases, respectively. Potential serotype coverage for meningitis and nonmeningitis cases was 45% and 49% for PCV-10, and 48% and 57% for PCV-13, respectively. Eighty-two percent of strains were susceptible to all antibiotics except cotrimoxazole. CONCLUSION The distribution of serotypes causing IPD in Bangladeshi children is diverse, limiting the proportion of IPD cases PCV can prevent. However, PCV introduction is expected to have major benefits as the country has a high burden of IPD-related mortality, morbidity and disability.
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Novel Strategy To Protect against Influenza Virus-Induced Pneumococcal Disease without Interfering with Commensal Colonization. Infect Immun 2016; 84:1693-1703. [PMID: 27001538 DOI: 10.1128/iai.01478-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/13/2016] [Indexed: 12/16/2022] Open
Abstract
Streptococcus pneumoniae commonly inhabits the nasopharynx as a member of the commensal biofilm. Infection with respiratory viruses, such as influenza A virus, induces commensal S. pneumoniae to disseminate beyond the nasopharynx and to elicit severe infections of the middle ears, lungs, and blood that are associated with high rates of morbidity and mortality. Current preventive strategies, including the polysaccharide conjugate vaccines, aim to eliminate asymptomatic carriage with vaccine-type pneumococci. However, this has resulted in serotype replacement with, so far, less fit pneumococcal strains, which has changed the nasopharyngeal flora, opening the niche for entry of other virulent pathogens (e.g., Streptococcus pyogenes, Staphylococcus aureus, and potentially Haemophilus influenzae). The long-term effects of these changes are unknown. Here, we present an attractive, alternative preventive approach where we subvert virus-induced pneumococcal disease without interfering with commensal colonization, thus specifically targeting disease-causing organisms. In that regard, pneumococcal surface protein A (PspA), a major surface protein of pneumococci, is a promising vaccine target. Intradermal (i.d.) immunization of mice with recombinant PspA in combination with LT-IIb(T13I), a novel i.d. adjuvant of the type II heat-labile enterotoxin family, elicited strong systemic PspA-specific IgG responses without inducing mucosal anti-PspA IgA responses. This response protected mice from otitis media, pneumonia, and septicemia and averted the cytokine storm associated with septic infection but had no effect on asymptomatic colonization. Our results firmly demonstrated that this immunization strategy against virally induced pneumococcal disease can be conferred without disturbing the desirable preexisting commensal colonization of the nasopharynx.
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Jacobitz AW, Naziga EB, Yi SW, McConnell SA, Peterson R, Jung ME, Clubb RT, Wereszczynski J. The "Lid" in the Streptococcus pneumoniae SrtC1 Sortase Adopts a Rigid Structure that Regulates Substrate Access to the Active Site. J Phys Chem B 2016; 120:8302-12. [PMID: 27109553 DOI: 10.1021/acs.jpcb.6b01930] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Many species of Gram-positive bacteria use sortase enzymes to assemble long, proteinaceous pili structures that project from the cell surface to mediate microbial adhesion. Sortases construct highly stable structures by catalyzing a transpeptidation reaction that covalently links pilin subunits together via isopeptide bonds. Most Gram-positive pili are assembled by class C sortases that contain a "lid", a structurally unique N-terminal extension that occludes the active site. It has been hypothesized that the "lid" in many sortases is mobile and thus capable of readily being displaced from the enzyme to facilitate substrate binding. Here, we show using NMR dynamics measurements, in vitro assays, and molecular dynamics simulations that the lid in the class C sortase from Streptococcus pneumoniae (SrtC1) adopts a rigid conformation in solution that is devoid of large magnitude conformational excursions that occur on mechanistically relevant time scales. Additionally, we show that point mutations in the lid induce dynamic behavior that correlates with increased hydrolytic activity and sorting signal substrate access to the active site cysteine residue. These results suggest that the lid of the S. pneumoniae SrtC1 enzyme has a negative regulatory function and imply that a significant energetic barrier must be surmounted by currently unidentified factors to dislodge it from the active site to initiate pilus biogenesis.
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Affiliation(s)
- Alex W Jacobitz
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Emmanuel B Naziga
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology , 3440 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Sung Wook Yi
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Scott A McConnell
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Robert Peterson
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Michael E Jung
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Robert T Clubb
- Department of Chemistry and Biochemistry and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles , 611 Charles E. Young Drive East, Los Angeles, California 90095-1570, United States
| | - Jeff Wereszczynski
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology , 3440 South Dearborn Street, Chicago, Illinois 60616, United States
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Shahid ASMSB, Ahmed T, Shahunja KM, Kabir S, Chowdhury F, Faruque ASG, Das SK, Sarker MHR, Bardhan PK, Chisti MJ. Factors Associated with Streptococcal Bacteremia in Diarrheal Children under Five Years of Age and Their Outcome in an Urban Hospital in Bangladesh. PLoS One 2016; 11:e0154777. [PMID: 27135829 PMCID: PMC4852900 DOI: 10.1371/journal.pone.0154777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 04/19/2016] [Indexed: 11/25/2022] Open
Abstract
Background Although Streptococcal bacteremia is common in diarrheal children with high morbidity and mortality, no systematic data are available on Streptococcal bacteremia in diarrheal children. We sought to evaluate the factors associated with Streptococcal bacteremia in diarrheal children under five years of age and their outcome. Methods We used an unmatched case-control design to investigate the associated factors with Streptococcal bacteremia in all the diarrheal children under five years of age through electronic medical record system of Dhaka hospital of International Centre for Diarrhoeal Disease Research, Bangladesh. We had simultaneously used a retrospective cohort design to further evaluate the outcome of our study children. All the enrolled children had their blood culture done between January 2010 and December 2012. Comparison was made among the children with (cases = 26) and without Streptococcal bacteremia (controls = 78). Controls were selected randomly from hospitalized diarrheal children under five years of age. Results Cases had proportionately higher deaths compared to controls, but it was statistically insignificant (15% vs. 10%, p = 0.49). The cases more often presented with severe dehydration, fever, respiratory distress, severe sepsis, and abnormal mental status compared to the controls (for all p<0.05). In the logistic regression analysis, after adjusting for potential confounders, it has been found that Streptococcal bacteremia in diarrheal children under five years of age was independently associated with nutritional edema (OR: 5.86, 95% CI = 1.28–26.80), hypoxemia (OR: 19.39, 95% CI = 2.14–175.91), fever (OR: 4.44, 95% CI = 1.13–17.42), delayed capillary refill time (OR: 7.00, 95% CI = 1.36–35.93), and respiratory distress (OR: 2.69, 95% CI = 1.02–7.12). Conclusions and Significance The results of our analyses suggest that diarrheal children under five years of age presenting with nutritional edema, hypoxemia, fever, delayed capillary refill time, and respiratory distress may be at risk of Streptococcal bacteremia. It underscores the importance of identification of these simple clinical parameters for the prompt recognition and management in order to reduce the morbidity and death of such children especially in resource limited settings.
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Affiliation(s)
| | - Tahmeed Ahmed
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - K M Shahunja
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Senjuti Kabir
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Fahmida Chowdhury
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Abu Syeed Golam Faruque
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Sumon Kumar Das
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mohammad Habibur Rahman Sarker
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Pradip Kumar Bardhan
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mohammod Jobayer Chisti
- Nutrition & Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
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Abstract
AIM We aimed to describe the detection rate spectrum of clinical manifestations, and outcome of pneumococcal disease in children younger than 5 years admitted to the largest referral pediatric hospital in Egypt. MATERIALS AND METHODS This was a hospital-based study to detect laboratory-confirmed Streptococcus pneumoniae cases among children younger than 5 years. Data on demographic characteristics, clinical diagnosis, comorbidities, diagnostic tests, antibiotic resistance, and clinical outcome were collected during the study years from 2008 to 2011. RESULTS During the 4-year study period, 22 018 cases younger than 5 years had cultures performed at Cairo University Pediatric Hospital microbiology laboratory. We estimated the annual detection rate of total Streptococcus pneumonia infection to be 54.5/100 000. The incidence of invasive pneumococcal disease (IPD) was half the incidence of non-IPD (18.2 and 36.4/100 000, respectively). Infants of 1 year or younger were statistically more vulnerable to Streptococcus pneumonia infection compared with children between 1 and 5 years of age (annual rate: 110.5/100 000 and 21.6/100 000, respectively). The overall pneumococcal annual case fatality was 33.3% and was higher in IPD (75%) than in non-IPD (12.5%) cases. There was an obviously increasing trend of the pneumococcal detection rate throughout the 4 years of the study (P<0.0001). CONCLUSION AND RECOMMENDATIONS Our results confirm the substantial and increasing pneumococcal infection, the emerging of multidrug resistant isolates, and the vulnerability of the younger age group and high-risk population, which calls for a national surveillance to inform policy and decision-making before national wide vaccine introduction.
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Cigarette Smoke Attenuates the Nasal Host Response to Streptococcus pneumoniae and Predisposes to Invasive Pneumococcal Disease in Mice. Infect Immun 2016; 84:1536-1547. [PMID: 26930709 DOI: 10.1128/iai.01504-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/25/2016] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pneumoniae is a leading cause of invasive bacterial infections, with nasal colonization an important first step in disease. While cigarette smoking is a strong risk factor for invasive pneumococcal disease, the underlying mechanisms remain unknown. This is partly due to a lack of clinically relevant animal models investigating nasal pneumococcal colonization in the context of cigarette smoke exposure. We present a model of nasal pneumococcal colonization in cigarette smoke-exposed mice and document, for the first time, that cigarette smoke predisposes to invasive pneumococcal infection and mortality in an animal model. Cigarette smoke increased the risk of bacteremia and meningitis without prior lung infection. Mechanistically, deficiency in interleukin 1α (IL-1α) or platelet-activating factor receptor (PAFR), an important host receptor thought to bind and facilitate pneumococcal invasiveness, did not rescue cigarette smoke-exposed mice from invasive pneumococcal disease. Importantly, we observed cigarette smoke to attenuate nasal inflammatory mediator expression, particularly that of neutrophil-recruiting chemokines, normally elicited by pneumococcal colonization. Smoking cessation during nasal pneumococcal colonization rescued nasal neutrophil recruitment and prevented invasive disease in mice. We propose that cigarette smoke predisposes to invasive pneumococcal disease by suppressing inflammatory processes of the upper respiratory tract. Given that smoking prevalence remains high worldwide, these findings are relevant to the continued efforts to reduce the invasive pneumococcal disease burden.
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Pneumococcal Colonization Rates in Patients Admitted to a United Kingdom Hospital with Lower Respiratory Tract Infection: a Prospective Case-Control Study. J Clin Microbiol 2016; 54:944-9. [PMID: 26791364 PMCID: PMC4809940 DOI: 10.1128/jcm.02008-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/29/2015] [Indexed: 11/20/2022] Open
Abstract
Current diagnostic tests are ineffective for identifying the etiological pathogen in hospitalized adults with lower respiratory tract infections (LRTIs). The association of pneumococcal colonization with disease has been suggested as a means to increase the diagnostic precision. We compared the pneumococcal colonization rates and the densities of nasal pneumococcal colonization by (i) classical culture and (ii) quantitative real-time PCR (qPCR) targetinglytAin patients with LRTIs admitted to a hospital in the United Kingdom and control patients. A total of 826 patients were screened for inclusion in this prospective case-control study. Of these, 38 patients were recruited, 19 with confirmed LRTIs and 19 controls with other diagnoses. Nasal wash (NW) samples were collected at the time of recruitment. Pneumococcal colonization was detected in 1 patient with LRTI and 3 controls (P= 0.6) by classical culture. By qPCR, pneumococcal colonization was detected in 10 LRTI patients and 8 controls (P= 0.5). Antibiotic usage prior to sampling was significantly higher in the LRTI group than in the control group (19 versus 3;P< 0.001). With a clinically relevant cutoff of >8,000 copies/ml on qPCR, pneumococcal colonization was found in 3 LRTI patients and 4 controls (P> 0.05). We conclude that neither the prevalence nor the density of nasal pneumococcal colonization (by culture and qPCR) can be used as a method of microbiological diagnosis in hospitalized adults with LRTI in the United Kingdom. A community-based study recruiting patients prior to antibiotic therapy may be a useful future step.
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Jehan F, Nisar MI, Kerai S, Brown N, Balouch B, Hyder Z, Ambler G, Ginsburg AS, Zaidi AKM. A double blind community-based randomized trial of amoxicillin versus placebo for fast breathing pneumonia in children aged 2-59 months in Karachi, Pakistan (RETAPP). BMC Infect Dis 2016; 16:13. [PMID: 26758747 PMCID: PMC4710982 DOI: 10.1186/s12879-015-1334-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 12/31/2015] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Fast breathing pneumonia is characterized by tachypnoea in the absence of danger signs and is mostly viral in etiology. Current guidelines recommend antibiotic therapy for all children with fast breathing pneumonia in resource limited settings, presuming that most pneumonia is bacterial. High quality clinical trial evidence to challenge or support the continued use of antibiotics, as recommended by the World Health Organization is lacking. METHODS/DESIGN This is a randomized double blinded placebo-controlled non-inferiority trial using parallel assignment with 1:1 allocation ratio, to be conducted in low income squatter settlements of urban Karachi, Pakistan. Children 2-59 months old with fast breathing, without any WHO-defined danger signs and seeking care at the primary health care center are randomized to receive either three days of placebo or amoxicillin. From prior studies, a sample size of 2430 children is required over a period of 28 months. Primary outcome is the difference in cumulative treatment failure between the two groups, defined as a new clinical sign based on preset definitions indicating illness progression or mortality and confirmed by two independent primary health care physicians on day 0, 1, 2 or 3 of therapy. Secondary outcomes include relapse measured between days 5-14. Modified per protocol analysis comparing hazards of treatment failure with 95% confidence intervals in the placebo arm with hazards in the amoxicillin arm will be done. DISCUSSION This study will provide evidence to support or refute the use of antibiotics for fast breathing pneumonia paving a way for guideline change. TRIAL REGISTRATION Clinical Trials (NIH) Register NCT02372461.
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Affiliation(s)
- Fyezah Jehan
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Muhammad Imran Nisar
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Salima Kerai
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Nick Brown
- Salisbury District Hospital Foundation Trust, Salisbury, Wiltshire, UK.
| | - Benazir Balouch
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | - Zulfiqar Hyder
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
| | | | | | - Anita K M Zaidi
- Department of Paediatrics and Child Health, Aga Khan University, Stadium Road, PO Box 3500, Karachi, 74800, Pakistan.
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Patrzałek M, Kotowska M, Goryński P, Albrecht P. Indirect effects of a 7 year PCV7/PCV13 mass vaccination program in children on the incidence of pneumonia among adults: a comparative study based on two Polish cities. Curr Med Res Opin 2016; 32:397-403. [PMID: 26566258 DOI: 10.1185/03007995.2015.1119676] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES In 2006 the city of Kielce, Poland, introduced a mandatory PCV7 (replaced by PCV13 in 2011) vaccination program against S. pneumoanie for all children under 2 years old. At that time, the neighboring city of Ostrowiec Świętokrzyski had no such large-scale vaccination program in place. This created an opportunity to observe the results of the vaccination by comparing the incidence of pneumonia in these two cities. The aim of this study was to analyze how the incidence of pneumonia among adults was indirectly affected by the PCV7/PCV13 vaccination program in children during the 7 year follow-up period. METHODS We performed a retrospective study. PCV7/PCV13 vaccinations were delivered according to a 2 + 1 schedule. The vaccination rate in the analyzed period amounted to almost 99%. The following age groups were analyzed: 30-49, 50-64 and 65+. The Cochran-Armitage test was used to investigate the significance of the observed trend in pneumonia morbidity. The significance of deviations from a linear trend was also tested. In addition, the importance of the trend (in the case of deviations from linearity) was confirmed with the use of the Mantel test. RESULTS In the 65+ age group there was a decrease of 66.5% in the incidence of diagnosed pneumonia (p < 0.0001). This was followed by smaller, but statistically significant, declines in the other age groups: 30.75% in the 30-49 age group (p = 0.001) and 56.8% in the 50-64 age group (p < 0.0001). This decreasing trend continued for seven consecutive years of observation. In addition, we demonstrated a statistically significant higher rate of pneumonia in all age groups in the City of Ostrowiec Świętokrzyski. CONCLUSIONS The results clearly indicate that the indirect effectiveness of the PCV7/PCV13 vaccine program, performed according to the 2 + 1 schedule and applied in Kielce, Poland, is statistically significant.
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Affiliation(s)
| | - M Kotowska
- b b Department of Paediatric Gastroenterology and Nutrition , Medical University of Warsaw , Poland
| | - P Goryński
- c c National Institute of Public Health, National Institute of Hygiene , Warsaw , Poland
| | - P Albrecht
- b b Department of Paediatric Gastroenterology and Nutrition , Medical University of Warsaw , Poland
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Hinman AR, McKinlay MA. Immunization Equity. Am J Prev Med 2015; 49:S399-405. [PMID: 26282089 DOI: 10.1016/j.amepre.2015.04.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/13/2015] [Accepted: 04/23/2015] [Indexed: 12/23/2022]
Abstract
Health inequities are the unjust differences in health among different social groups. Unfortunately, inequities are the norm, both in terms of health status and access to, and use of, health services. Childhood immunizations reduce the incidence of vaccine-preventable diseases and represent a cost-effective way to foster health equity. This paper reflects a 2015 review of data from surveys conducted in developing countries from 2005 to 2011 that show significant inequities in immunization coverage and discusses several initiatives currently underway (including Gavi, the Vaccine Alliance) that are directed at increasing childhood immunizations or reducing or abolishing overall health inequities. These initiatives have already had a significant impact on disease burden and childhood mortality and give rise to optimism that health disparities may further be reduced and health equity achieved as a result of investments made in immunization.
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Affiliation(s)
- Alan R Hinman
- Center for Vaccine Equity, the Task Force for Global Health, Decatur, Georgia.
| | - Mark A McKinlay
- Center for Vaccine Equity, the Task Force for Global Health, Decatur, Georgia
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Sun T, Hou H, Lu J, Xu M, Gu T, Wang D, Dong Y, Jiang C, Kong W, Wu Y. Detection and comparison of structure and function of wild-type pneumolysin and its novel mutant PlyM2. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-5105-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Differences in antibiotic-induced oxidative stress responses between laboratory and clinical isolates of Streptococcus pneumoniae. Antimicrob Agents Chemother 2015; 59:5420-6. [PMID: 26100702 DOI: 10.1128/aac.00316-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/15/2015] [Indexed: 11/20/2022] Open
Abstract
Oxidants were shown to contribute to the lethality of bactericidal antibiotics in different bacterial species, including the laboratory strain Streptococcus pneumoniae R6. Resistance to penicillin among S. pneumoniae R6 mutants was further shown to protect against the induction of oxidants upon exposure to unrelated bactericidal compounds. In the work described here, we expanded on these results by studying the accumulation of reactive oxygen species in the context of antibiotic sensitivity and resistance by including S. pneumoniae clinical isolates. In S. pneumoniae R6, penicillin, ciprofloxacin, and kanamycin but not the bacteriostatic linezolid, erythromycin, or tetracycline induced the accumulation of reactive oxygen species. For the three bactericidal compounds, resistance to a single molecule prevented the accumulation of oxidants upon exposure to unrelated bactericidal antibiotics, and this was accompanied by a reduced lethality. This phenomenon does not involve target site mutations but most likely implicates additional mutations occurring early during the selection of resistance to increase survival while more efficient resistance mechanisms are being selected or acquired. Bactericidal antibiotics also induced oxidants in sensitive S. pneumoniae clinical isolates. The importance of oxidants in the lethality of bactericidal antibiotics was less clear than for S. pneumoniae R6, however, since ciprofloxacin induced oxidants even in ciprofloxacin-resistant S. pneumoniae clinical isolates. Our results provide a clear example of the complex nature of the mode of action of antibiotics. The adaptive approach to oxidative stress of S. pneumoniae is peculiar, and a better understanding of the mechanism implicated in response to oxidative injury should also help clarify the role of oxidants induced by antibiotics.
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Sobota A, Sabharwal V, Fonebi G, Steinberg M. How we prevent and manage infection in sickle cell disease. Br J Haematol 2015; 170:757-67. [PMID: 26018640 DOI: 10.1111/bjh.13526] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sickle cell disease (SCD) affects approximately 100,000 people in the US, 12,500 in the UK, and millions worldwide. SCD is typified by painful vaso-occlusive episodes, haemolytic anaemia and organ damage. A secondary complication is infection, which can be bacterial, fungal or viral. Universal newborn screening, routine use of penicillin prophylaxis, availability of conjugated vaccines against S. pneumoniae and comprehensive care programmes instituted during the past few decades in industrialized countries have dramatically reduced childhood mortality and improved life expectancy. Yet patients with SCD remain at increased risk of infection. Unfortunately, the treatment of most bacterial infections that are common in SCD is not based on the results of randomized controlled clinical trials. In their absence, treatment decisions are based on consensus guidelines, clinical experience or adapting treatment applied in other diseases. This leads to wide variation in treatment among institutions and even between treating physicians in a single institution. Prevention of infection, when possible, is most important and we focus on prevention through targeted prophylaxis and vaccination. We will share our management strategies for managing the more common infections in SCD and provide the rationale for our recommendations.
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Affiliation(s)
- Amy Sobota
- Boston University School of Medicine, Boston, MA, USA.,Department of Pediatrics, Boston Medical Center, Boston, MA, USA
| | - Vishakha Sabharwal
- Boston University School of Medicine, Boston, MA, USA.,Department of Pediatrics, Boston Medical Center, Boston, MA, USA
| | - Gwendoline Fonebi
- Boston University School of Medicine, Boston, MA, USA.,Department of Medicine, Boston Medical Center, Boston, MA, USA
| | - Martin Steinberg
- Boston University School of Medicine, Boston, MA, USA.,Department of Medicine, Boston Medical Center, Boston, MA, USA
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Wilson R, Cohen JM, Jose RJ, de Vogel C, Baxendale H, Brown JS. Protection against Streptococcus pneumoniae lung infection after nasopharyngeal colonization requires both humoral and cellular immune responses. Mucosal Immunol 2015; 8:627-39. [PMID: 25354319 PMCID: PMC4351900 DOI: 10.1038/mi.2014.95] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/13/2014] [Indexed: 02/04/2023]
Abstract
Streptococcus pneumoniae is a common cause of pneumonia and infective exacerbations of chronic lung disease, yet there are few data on how adaptive immunity can specifically prevent S. pneumoniae lung infection. We have used a murine model of nasopharyngeal colonization by the serotype 19F S. pneumoniae strain EF3030 followed by lung infection to investigate whether colonization protects against subsequent lung infection and the mechanisms involved. EF3030 colonization induced systemic and local immunoglobulin G against a limited number of S. pneumoniae protein antigens rather than capsular polysaccharide. During lung infection, previously colonized mice had increased early cytokine responses and neutrophil recruitment and reduced bacterial colony-forming units in the lungs and bronchoalveolar lavage fluid compared with control mice. Colonization-induced protection was lost when experiments were repeated in B-cell- or neutrophil-deficient mice. Furthermore, the improved interleukin (IL)-17 response to infection in previously colonized mice was abolished by depletion of CD4+ cells, and prior colonization did not protect against lung infection in mice depleted of CD4+ cells or IL17. Together these data show that naturally acquired protective immunity to S. pneumoniae lung infection requires both humoral and cell-mediated immune responses, providing a template for the design of improved vaccines that can specifically prevent pneumonia or acute bronchitis.
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Affiliation(s)
- R Wilson
- Centre for Inflammation and Tissue Repair, Division of Medicine, University College Medical School, Rayne Institute, London, UK
| | - J M Cohen
- Infectious Diseases and Microbiology Unit, UCL Institute of Child Health, London, UK
| | - R J Jose
- Centre for Inflammation and Tissue Repair, Division of Medicine, University College Medical School, Rayne Institute, London, UK
| | - C de Vogel
- Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands
| | - H Baxendale
- Clinical Immunology Department, Papworth Hospital NHS Foundation Trust, Cambridge, UK
| | - J S Brown
- Centre for Inflammation and Tissue Repair, Division of Medicine, University College Medical School, Rayne Institute, London, UK,()
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Lupien A, Gingras H, Bergeron MG, Leprohon P, Ouellette M. Multiple mutations and increased RNA expression in tetracycline-resistant Streptococcus pneumoniae as determined by genome-wide DNA and mRNA sequencing. J Antimicrob Chemother 2015; 70:1946-59. [PMID: 25862682 DOI: 10.1093/jac/dkv060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/13/2015] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES The objective of this study was to characterize chromosomal mutations associated with resistance to tetracycline in Streptococcus pneumoniae. METHODS Chronological appearance of mutations in two S. pneumoniae R6 mutants (R6M1TC-5 and R6M2TC-4) selected for resistance to tetracycline was determined by next-generation sequencing. A role for the mutations identified was confirmed by reconstructing resistance to tetracycline in a S. pneumoniae R6 WT background. RNA sequencing was performed on R6M1TC-5 and R6M2TC-4 and the relative expression of genes was reported according to R6. Differentially expressed genes were classified according to their ontology. RESULTS WGS of R6M1TC-5 and R6M2TC-4 revealed mutations in the gene rpsJ coding for the ribosomal protein S10 and in the promoter region and coding sequences of the ABC genes patA and patB. These cells were cross-resistant to ciprofloxacin. Resistance reconstruction confirmed a role in resistance for the mutations in rpsJ and patA. Overexpression of the ABC transporter PatA/PatB or mutations in the coding sequence of patA contributed to resistance to tetracycline, ciprofloxacin and ethidium bromide, and was associated with a decreased accumulation of [(3)H]tetracycline. Comparative transcriptome profiling of the resistant mutants further revealed that, in addition to the overexpression of patA and patB, several genes of the thiamine biosynthesis and salvage pathway were increased in the two mutants, but also in clinical isolates resistant to tetracycline. This overexpression most likely contributes to the tetracycline resistance phenotype. CONCLUSIONS The combination of genomic and transcriptomic analysis coupled to functional studies has allowed the discovery of novel tetracycline resistance mutations in S. pneumoniae.
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Affiliation(s)
- Andréanne Lupien
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Hélène Gingras
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Michel G Bergeron
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Philippe Leprohon
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Marc Ouellette
- Centre de recherche en Infectiologie du Centre de recherche du CHU de Québec and Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
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Hospital-based surveillance of invasive pneumococcal disease and pneumonia in South Bangalore, India. Indian Pediatr 2015; 52:205-11. [DOI: 10.1007/s13312-015-0607-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ivanov S, Paget C, Trottein F. Role of non-conventional T lymphocytes in respiratory infections: the case of the pneumococcus. PLoS Pathog 2014; 10:e1004300. [PMID: 25299581 PMCID: PMC4192596 DOI: 10.1371/journal.ppat.1004300] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Non-conventional T lymphocytes constitute a special arm of the immune system and act as sentinels against pathogens at mucosal surfaces. These non-conventional T cells (including mucosal-associated invariant T [MAIT] cells, gamma delta [γδ] T cells, and natural killer T [NKT] cells) display several innate cell-like features and are rapidly activated by the recognition of conserved, stress-induced, self, and microbial ligands. Here, we review the role of non-conventional T cells during respiratory infections, with a particular focus on the encapsulated extracellular pathogen Streptococcus pneumoniae, the leading cause of bacterial pneumonia worldwide. We consider whether MAIT cells, γδ T cells, and NKT cells might offer opportunities for preventing and/or treating human pneumococcus infections.
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Affiliation(s)
- Stoyan Ivanov
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Université Lille Nord de France, Lille, France
| | - Christophe Paget
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Université Lille Nord de France, Lille, France
| | - François Trottein
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Lille, France
- Institut National de la Santé et de la Recherche Médicale, U1019, Lille, France
- Centre National de la Recherche Scientifique, UMR 8204, Lille, France
- Université Lille Nord de France, Lille, France
- * E-mail:
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Marais BJ, Rabie H, Schaaf SH, Cotton MF. Common opportunistic infections in HIV infected infants and children Part 1—respiratory infections. S Afr Fam Pract (2004) 2014. [DOI: 10.1080/20786204.2006.10873487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Shaik MM, Maccagni A, Tourcier G, Di Guilmi AM, Dessen A. Structural basis of pilus anchoring by the ancillary pilin RrgC of Streptococcus pneumoniae. J Biol Chem 2014; 289:16988-97. [PMID: 24755220 DOI: 10.1074/jbc.m114.555854] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Pili are surface-attached, fibrous virulence factors that play key roles in the pathogenesis process of a number of bacterial agents. Streptococcus pneumoniae is a causative agent of pneumonia and meningitis, and the appearance of drug-resistance organisms has made its treatment challenging, especially in developing countries. Pneumococcus-expressed pili are composed of three structural proteins: RrgB, which forms the polymerized backbone, RrgA, the tip-associated adhesin, and RrgC, which presumably associates the pilus with the bacterial cell wall. Despite the fact that the structures of both RrgA and RrgB were known previously, structural information for RrgC was still lacking, impeding the analysis of a complete model of pilus architecture. Here, we report the structure of RrgC to 1.85 Å and reveal that it is a three-domain molecule stabilized by two intradomain isopeptide bonds. RrgC does not depend on pilus-specific sortases to become attached to the cell wall; instead, it binds the preformed pilus to the peptidoglycan by employing the catalytic activity of SrtA. A comprehensive model of the type 1 pilus from S. pneumoniae is also presented.
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Affiliation(s)
- Md Munan Shaik
- From the Institut de Biologie Structurale (IBS), Université Grenoble Alpes, 41 avenue des Martyrs, 38044 Grenoble, France, the Commissariat à l'Energie Atomique (CEA), 38000 Grenoble, France, the Centre National de la Recherche Scientifique (CNRS), UMR 5075, Grenoble, France, and
| | - Amandine Maccagni
- From the Institut de Biologie Structurale (IBS), Université Grenoble Alpes, 41 avenue des Martyrs, 38044 Grenoble, France, the Commissariat à l'Energie Atomique (CEA), 38000 Grenoble, France, the Centre National de la Recherche Scientifique (CNRS), UMR 5075, Grenoble, France, and
| | - Guillaume Tourcier
- From the Institut de Biologie Structurale (IBS), Université Grenoble Alpes, 41 avenue des Martyrs, 38044 Grenoble, France, the Commissariat à l'Energie Atomique (CEA), 38000 Grenoble, France, the Centre National de la Recherche Scientifique (CNRS), UMR 5075, Grenoble, France, and
| | - Anne Marie Di Guilmi
- From the Institut de Biologie Structurale (IBS), Université Grenoble Alpes, 41 avenue des Martyrs, 38044 Grenoble, France, the Commissariat à l'Energie Atomique (CEA), 38000 Grenoble, France, the Centre National de la Recherche Scientifique (CNRS), UMR 5075, Grenoble, France, and
| | - Andréa Dessen
- From the Institut de Biologie Structurale (IBS), Université Grenoble Alpes, 41 avenue des Martyrs, 38044 Grenoble, France, the Commissariat à l'Energie Atomique (CEA), 38000 Grenoble, France, the Centre National de la Recherche Scientifique (CNRS), UMR 5075, Grenoble, France, and the Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, 13083-100 São Paulo, Brazil
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Ulloa-Gutierrez R, Avila-Aguero ML. 6th International Symposium on Pneumococci and Pneumococcal Diseases. Expert Rev Vaccines 2014; 7:725-8. [DOI: 10.1586/14760584.7.6.725] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Grijalva CG, Griffin MR. Population-based impact of routine infant immunization with pneumococcal conjugate vaccine in the USA. Expert Rev Vaccines 2014; 7:83-95. [PMID: 18251696 DOI: 10.1586/14760584.7.1.83] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Carlos G Grijalva
- Division of Pharmacoepidemiology, Department of Preventive Medicine, Vanderbilt University School of Medicine, 1500 21st Ave S. The Village at Vanderbilt Suite # 2650, Nashville, TN 37212, USA.
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47
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Global Health. THE NEW PUBLIC HEALTH 2014. [PMCID: PMC7171909 DOI: 10.1016/b978-0-12-415766-8.00016-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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48
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Genomic characterization of ciprofloxacin resistance in a laboratory-derived mutant and a clinical isolate of Streptococcus pneumoniae. Antimicrob Agents Chemother 2013; 57:4911-9. [PMID: 23877698 DOI: 10.1128/aac.00418-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The broad-spectrum fluoroquinolone ciprofloxacin is a bactericidal antibiotic targeting DNA topoisomerase IV and DNA gyrase encoded by the parC and gyrA genes. Resistance to ciprofloxacin in Streptococcus pneumoniae mainly occurs through the acquisition of mutations in the quinolone resistance-determining region (QRDR) of the ParC and GyrA targets. A role in low-level ciprofloxacin resistance has also been attributed to efflux systems. To look into ciprofloxacin resistance at a genome-wide scale and to discover additional mutations implicated in resistance, we performed whole-genome sequencing of an S. pneumoniae isolate selected for resistance to ciprofloxacin in vitro (128 μg/ml) and of a clinical isolate displaying low-level ciprofloxacin resistance (2 μg/ml). Gene disruption and DNA transformation experiments with PCR fragments harboring the mutations identified in the in vitro S. pneumoniae mutant revealed that resistance is mainly due to QRDR mutations in parC and gyrA and to the overexpression of the ABC transporters PatA and PatB. In contrast, no QRDR mutations were identified in the genome of the S. pneumoniae clinical isolate with low-level resistance to ciprofloxacin. Assays performed in the presence of the efflux pump inhibitor reserpine suggested that resistance is likely mediated by efflux. Interestingly, the genome sequence of this clinical isolate also revealed mutations in the coding region of patA and patB that we implicated in resistance. Finally, a mutation in the NAD(P)H-dependent glycerol-3-phosphate dehydrogenase identified in the S. pneumoniae clinical strain was shown to protect against ciprofloxacin-mediated reactive oxygen species.
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Hudson LD, Viner RM, Christie D. Long-Term Sequelae of Childhood Bacterial Meningitis. Curr Infect Dis Rep 2013; 15:236-41. [DOI: 10.1007/s11908-013-0332-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Abstract
Acute bacterial meningitis causes a substantial number of deaths in Cameroon. Among 170 children with acute meningitis, 112 were positive for a bacterial pathogen when tested using polymerase chain reaction amplification, and Streptococcus pneumoniae accounted for 57.1% of cases. Pneumococcal serotype coverage by 13-valent pneumococcal conjugate vaccine was 62.1%. This study shows that in Cameroon, 13-valent pneumococcal conjugate vaccine coverage is less than what is estimated for other African countries.
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