scholarly journals Discovery of Novel Pneumococcal Serotype 35D, a Natural WciG-Deficient Variant of Serotype 35B

2017 ◽  
Vol 55 (5) ◽  
pp. 1416-1425 ◽  
Author(s):  
K. Aaron Geno ◽  
Jamil S. Saad ◽  
Moon H. Nahm
Keyword(s):  
Pneumococcal Disease ◽  
Genetic Basis ◽  
Capsular Polysaccharide ◽  
Vaccine Candidate ◽  
Capsular Polysaccharides ◽  
Conjugate Vaccines ◽  
Content Type ◽  
Magnetic Resonance Studies ◽  
Pneumococcal Serotype ◽  
Inactivating Mutations

ABSTRACTPneumococcus (Streptococcus pneumoniae) remains a significant cause of morbidity and mortality, especially among those at the extremes of age. Its capsular polysaccharide is essential for systemic virulence. Over 90 serologically distinct pneumococcal capsular polysaccharides (serotypes) are recognized, but they are unequal in prevalence. Because antibodies against the capsule are protective, polysaccharide conjugate vaccines, which are constructed against the most prevalent serotypes, have caused great reductions in pneumococcal disease caused by these serotypes. In response, however, the relative prevalences of serotypes have shifted. Certain previously rare serotypes, such as serotype 35B, are increasing in prevalence. Serotype 35B is thus a likely future vaccine candidate, but due to their previous rarity, serotype 35B strains have not been scrutinized for underlying heterogeneity. We studied putative serotype 35B clinical isolates to assess the uniformity of their serological reactions. While most isolates exhibited the accepted serology of serotype 35B, one isolate failed to bind to critical serotyping reagents. We determined that the genetic basis for this aberrant serology was the presence of inactivating mutations in theO-acetyltransferase genewciG. Complementation studies in awciGdeletion strain verified that the mutant WciG was nonfunctional, and the serology of the mutant could be restored through complementation with a construct encoding a functional WciG. Nuclear magnetic resonance studies confirmed that the capsule of the WciG-deficient isolate lackedO-acetylation but was otherwise identical to serotype 35B. As this isolate expresses a unique serology with unique biochemistry and a stable genetic basis, we named its novel capsule serotype 35D.

scholarly journals Antibodies to Streptococcus pneumoniae Capsular Polysaccharide Enhance Pneumococcal Quorum Sensing

mBio ◽  
2011 ◽  
Vol 2 (5) ◽  
Author(s):  
Masahide Yano ◽  
Shruti Gohil ◽  
J. Robert Coleman ◽  
Catherine Manix ◽  
Liise-anne Pirofski
Keyword(s):  
Monoclonal Antibodies ◽  
Streptococcus Pneumoniae ◽  
Quorum Sensing ◽  
Direct Effect ◽  
Pneumococcal Disease ◽  
Effector Cell ◽  
Capsular Polysaccharide ◽  
Genetic Exchange ◽  
Content Type ◽  
Specific Antibodies

ABSTRACTThe use of pneumococcal capsular polysaccharide (PPS)-based vaccines has resulted in a substantial reduction in invasive pneumococcal disease. However, much remains to be learned about vaccine-mediated immunity, as seven-valent PPS-protein conjugate vaccine use in children has been associated with nonvaccine serotype replacement and 23-valent vaccine use in adults has not prevented pneumococcal pneumonia. In this report, we demonstrate that certain PPS-specific monoclonal antibodies (MAbs) enhance the transformation frequency of two differentStreptococcus pneumoniaeserotypes. This phenomenon was mediated by PPS-specific MAbs that agglutinate but do not promote opsonic effector cell killing of the homologous serotypeinvitro. Compared to the autoinducer, competence-stimulating peptide (CSP) alone, transcriptional profiling of pneumococcal gene expression after incubation with CSP and one such MAb to the PPS of serotype 3 revealed changes in the expression of competence (com)-related and bacteriocin-like peptide (blp) genes involved in pneumococcal quorum sensing. This MAb was also found to induce a nearly 2-fold increase in CSP2-mediated bacterial killing or fratricide. These observations reveal a novel, direct effect of PPS-binding MAbs on pneumococcal biology that has important implications for antibody immunity to pneumococcus in the pneumococcal vaccine era. Taken together, our data suggest heretofore unsuspected mechanisms by which PPS-specific antibodies could affect genetic exchange and bacterial viability in the absence of host cells.IMPORTANCECurrent thought holds that pneumococcal capsular polysaccharide (PPS)-binding antibodies protect against pneumococcus by inducing effector cell opsonic killing of the homologous serotype. While such antibodies are an important part of how pneumococcal vaccines protect against pneumococcal disease, PPS-specific antibodies that do not exhibit this activity but are highly protective against pneumococcus in mice have been identified. This article examines the effect of nonopsonic PPS-specific monoclonal antibodies (MAbs) on the biology ofStreptococcus pneumoniae. The results showed that in the presence of a competence-stimulating peptide (CSP), such MAbs increase the frequency of pneumococcal transformation. Further studies with one such MAb showed that it altered the expression of genes involved in quorum sensing and increased competence-induced killing or fratricide. These findings reveal a novel, previously unsuspected mechanism by which certain PPS-specific antibodies exert a direct effect on pneumococcal biology that has broad implications for bacterial clearance, genetic exchange, and antibody immunity to pneumococcus.

scholarly journals Should Pneumococcal Serotype 3 Be Included in Serotype-Specific Immunoassays?

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Ezra Linley ◽  
Abigail Bell ◽  
Jenna F. Gritzfeld ◽  
Ray Borrow
Keyword(s):  
Conjugate Vaccine ◽  
Invasive Pneumococcal Disease ◽  
Pneumococcal Conjugate Vaccine ◽  
Pneumococcal Disease ◽  
Capsular Polysaccharide ◽  
Multiplex Assay ◽  
Limited Efficacy ◽  
The Future ◽  
Pneumococcal Serotype

Since the introduction of the 13-valent pneumococcal conjugate vaccine, a number of studies have demonstrated the limited efficacy of the pneumococcal serotype 3 component of this vaccine. Evidence from seven countries (Denmark, France, Greece, Portugal, Sweden, UK, US) shows limited or no effectiveness of the 13-valent pneumococcal conjugate vaccine against serotype 3 invasive pneumococcal disease and carriage. The serotype 3 capsule has some unique characteristics that may serve to explain this lack of efficacy—capsular polysaccharide is abundantly expressed, leading to a greater thickness of capsule, and free capsular polysaccharide may be released during growth. The serotype 3 component of the Luminex multiplex assay demonstrates inferior inter-laboratory reproducibility than other components and results may not be reliable. This communication outlines this evidence and discusses whether it is necessary to include serotype 3 in the assay in the future.

scholarly journals Two DHH Subfamily 1 Proteins Contribute to Pneumococcal Virulence and Confer Protection against Pneumococcal Disease

2011 ◽  
Vol 79 (9) ◽  
pp. 3697-3710 ◽  
Author(s):  
L. E. Cron ◽  
K. Stol ◽  
P. Burghout ◽  
S. van Selm ◽  
E. R. Simonetti ◽  
...  
Keyword(s):  
Otitis Media ◽  
Pneumococcal Disease ◽  
Capsular Polysaccharide ◽  
Pneumococcal Infection ◽  
Bacterial Pathogen ◽  
Protein Vaccine ◽  
Double Knockout ◽  
Content Type ◽  
Knockout Mutants ◽  
Different Strains

ABSTRACTStreptococcus pneumoniaeis an important human bacterial pathogen, causing such infections as pneumonia, meningitis, septicemia, and otitis media. Current capsular polysaccharide-based conjugate vaccines protect against a fraction of the over 90 serotypes known, whereas vaccines based on conserved pneumococcal proteins are considered promising broad-range alternatives. The pneumococcal genome encodes two conserved proteins of an as yet unknown function, SP1298 and SP2205, classified as DHH (Asp-His-His) subfamily 1 proteins. Here we examined their contribution to pneumococcal pathogenesis using single and double knockout mutants in three different strains: D39, TIGR4, and BHN100. Mutants lacking both SP1298 and SP2205 were severely impaired in adherence to human epithelial Detroit 562 cells. Importantly, the attenuated phenotypes were restored upon genetic complementation of the deleted genes. Single and mixed mouse models of colonization, otitis media, pneumonia, and bacteremia showed that bacterial loads in the nasopharynx, middle ears, lungs, and blood of mice infected with the mutants were significantly reduced from those of wild-type-infected mice, with an apparent additive effect upon deletion of both genes. Minor strain-specific phenotypes were observed, i.e., deletion of SP1298 affected host-cell adherence in BHN100 only, and deletion of SP2205 significantly attenuated virulence in lungs and blood in D39 and BHN100 but not TIGR4. Finally, subcutaneous vaccination with a combination of both DHH subfamily 1 proteins conferred protection to nasopharynx, lungs, and blood of mice infected with TIGR4. We conclude that SP1298 and SP2205 play a significant role at several stages of pneumococcal infection, and importantly, these proteins are potential candidates for a multicomponent protein vaccine.

scholarly journals Competitive Inhibition Flow Analysis Assay for the Non-Culture-Based Detection and Serotyping of Pneumococcal Capsular Polysaccharide

2008 ◽  
Vol 16 (2) ◽  
pp. 222-229 ◽  
Author(s):  
H. Findlow ◽  
G. Laher ◽  
P. Balmer ◽  
C. Broughton ◽  
E. D. Carrol ◽  
...  
Keyword(s):  
Large Scale ◽  
Capsular Polysaccharide ◽  
Competitive Inhibition ◽  
Flow Analysis ◽  
High Risk Patient ◽  
Epidemiologic Studies ◽  
Conjugate Vaccines ◽  
The United Kingdom ◽  
Pneumococcal Serotype ◽  
Patient Groups

ABSTRACT Traditional confirmation procedures for the identification of a pneumococcal serotype require an isolate. Non-culture-based confirmation protocols are available. Some of these confirm only the presence of pneumococci, and others are capable of identifying a limited number of serotypes. The increased use of pneumococcal polysaccharide and conjugate vaccines, especially in high-risk patient groups, and the likely increase in the number of serotypes included in future versions of the conjugate vaccines have necessitated the need for improved enhanced surveillance in order to assess their impact on public health. Since 2006, a multiplexed assay has been used at the Health Protection Agency of the United Kingdom for the detection of 14 pneumococcal serotypes which requires pneumococcal serotype-specific monoclonal antibodies (MAbs). We have developed a microsphere competitive inhibition method capable of detecting 23 pneumococcal capsular polysaccharide serotypes in cerebrospinal fluid (CSF) and urine and serotyping pneumococcal suspensions, utilizing an international reference serum, 89-SF. The assay was shown to be reproducible and specific for homologous polysaccharide. Validation of the assay was performed with a selection of MAbs specific for pneumococcal capsular polysaccharide serotypes, which confirmed the specificity of the assay. Analysis of pneumolysin PCR-positive CSF samples in the competitive inhibition assay determined a serotype for 89% of the samples. The assay developed here is well suited to large-scale epidemiologic studies because the assay is simple, robust, and rapid and utilizes readily available resources.

scholarly journals Serum Antibody Responses against Carbapenem-Resistant Klebsiella pneumoniae in Infected Patients

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kasturi Banerjee ◽  
Michael P. Motley ◽  
Elizabeth Diago-Navarro ◽  
Bettina C. Fries
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Capsular Polysaccharides ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Reactive Properties

ABSTRACT Capsular polysaccharide (CPS) heterogeneity within carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strain sequence type 258 (ST258) must be considered when developing CPS-based vaccines. Here, we sought to characterize CPS-specific antibody responses elicited by CR-Kp-infected patients. Plasma and bacterial isolates were collected from 33 hospital patients with positive CR-Kp cultures. Isolate capsules were typed by wzi sequencing. Reactivity and measures of efficacy of patient antibodies were studied against 3 prevalent CR-Kp CPS types (wzi29, wzi154, and wzi50). High IgG titers against wzi154 and wzi50 CPS were documented in 79% of infected patients. Patient-derived (PD) IgGs agglutinated CR-Kp and limited growth better than naive IgG and promoted phagocytosis of strains across the serotype isolated from their donors. Additionally, poly-IgG from wzi50 and wzi154 patients promoted phagocytosis of nonconcordant CR-Kp serotypes. Such effects were lost when poly-IgG was depleted of CPS-specific IgG. Additionally, mice infected with wzi50, wzi154, and wzi29 CR-Kp strains preopsonized with wzi50 patient-derived IgG exhibited lower lung CFU than controls. Depletion of wzi50 antibodies (Abs) reversed this effect in wzi50 and wzi154 infections, whereas wzi154 Ab depletion reduced poly-IgG efficacy against wzi29 CR-Kp. We are the first to report cross-reactive properties of CPS-specific Abs from CR-Kp patients through both in vitro and in vivo models. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae is a rapidly emerging public health threat that can cause fatal infections in up to 50% of affected patients. Due to its resistance to nearly all antimicrobials, development of alternate therapies like antibodies and vaccines is urgently needed. Capsular polysaccharides constitute important targets, as they are crucial for Klebsiella pneumoniae pathogenesis. Capsular polysaccharides are very diverse and, therefore, studying the host’s capsule-type specific antibodies is crucial to develop effective anti-CPS immunotherapies. In this study, we are the first to characterize humoral responses in infected patients against carbapenem-resistant Klebsiella pneumoniae expressing different wzi capsule types. This study is the first to report the efficacy of cross-reactive properties of CPS-specific Abs in both in vitro and in vivo models.

scholarly journals Evolution of pneumococcal serotype epidemiology in Botswana following introduction of 13-valent pneumococcal conjugate vaccine

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262225
Author(s):  
Sweta M. Patel ◽  
Yazdani B. Shaik-Dasthagirisaheb ◽  
Morgan Congdon ◽  
Rebecca R. Young ◽  
Mohamed Z. Patel ◽  
...  
Keyword(s):  
Conjugate Vaccine ◽  
Invasive Pneumococcal Disease ◽  
Pneumococcal Conjugate Vaccine ◽  
Pneumococcal Disease ◽  
Conjugate Vaccines ◽  
Vaccine Serotypes ◽  
Vaccine Introduction ◽  
Molecular Serotyping ◽  
Sustained Effect ◽  
Pneumococcal Serotype

Pneumococcal conjugate vaccines reduce the burden of invasive pneumococcal disease, but the sustained effect of these vaccines can be diminished by an increase in disease caused by non-vaccine serotypes. To describe pneumococcal serotype epidemiology in Botswana following introduction of 13-valent pneumococcal conjugate vaccine (PCV-13) in July 2012, we performed molecular serotyping of 268 pneumococcal strains isolated from 221 children between 2012 and 2017. The median (interquartile range) age of the children included in this analysis was 6 (3,12) months. Fifty-nine percent of the children had received at least one dose of PCV-13 and 35% were fully vaccinated with PCV-13. While colonization by vaccine serotypes steadily declined following PCV-13 introduction, 25% of strains isolated more than 3 years after vaccine introduction were PCV-13 serotypes. We also observed an increase in colonization by non-vaccine serotypes 21 and 23B, which have been associated with invasive pneumococcal disease and antibiotic resistance in other settings.

scholarly journals The Pneumococcal Serotype 15C Capsule Is Partially O-Acetylated and Allows for Limited Evasion of 23-Valent Pneumococcal Polysaccharide Vaccine-Elicited Anti-Serotype 15B Antibodies

2017 ◽  
Vol 24 (8) ◽  
Author(s):  
Brady L. Spencer ◽  
Anukul T. Shenoy ◽  
Carlos J. Orihuela ◽  
Moon H. Nahm
Keyword(s):  
Polysaccharide Vaccine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Capsular Polysaccharides ◽  
Pneumococcal Polysaccharide Vaccine ◽  
Sugar Composition ◽  
Replication Slippage ◽  
Content Type ◽  
Pneumococcal Serotype ◽  
The Impact ◽  
Better Than

ABSTRACT As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acetyltransferase gene wciZ. The coding sequence of wciZ contains eight consecutive TA repeats [(TA)8]. Replication slippage is thought to result in the addition or loss of TA repeats, subsequently causing frameshift and truncation of WciZ to yield a nonacetylated serotype, 15C. Using sensitive serological tools, we show that serotype 15C isolates whose wciZ contains seven or nine TA repeats retain partial O-acetylation, while serotype 15C isolates whose wciZ contains six TA repeats have barely detectable O-acetylation. We confirmed by inhibition enzyme-linked immunosorbent assay that (TA)7 serotype 15C is ∼0.1% as acetylated as serotype 15B, while serotype 15X is nonacetylated. To eliminate the impact of genetic background, we created isogenic serotype 15B, (TA)7 serotype 15C, and 15BΔwciZ (15X) strains and found that reduction or absence of WciZ-mediated O-acetylation did not affect capsular shielding from phagocytes, biofilm formation, adhesion to nasopharyngeal cells, desiccation tolerance, or murine colonization. Sera from PPV23-immunized persons opsonized serotype 15B significantly but only slightly better than serotypes 15C and 15X; thus, PPV23 may not result in expansion of serotype 15C.

scholarly journals A Structural Model for the Ligand Binding of Pneumococcal Serotype 3 Capsular Polysaccharide-Specific Protective Antibodies

mBio ◽  
2021 ◽  
Author(s):  
Ahmet Ozdilek ◽  
Jiachen Huang ◽  
Rachelle Babb ◽  
Amy V. Paschall ◽  
Dustin R. Middleton ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Structural Model ◽  
Capsular Polysaccharide ◽  
Capsular Polysaccharides ◽  
Bacterial Diseases ◽  
Major Threat ◽  
Protective Antibodies ◽  
Pneumococcal Serotype ◽  
Glycoconjugate Vaccines ◽  
Main Components

Infectious diseases caused by pathogenic bacteria are a major threat to human health. Capsular polysaccharides (CPSs) of many pathogenic bacteria have been used as the main components of glycoconjugate vaccines against bacterial diseases in clinical practice worldwide, with various degrees of success.

The structure of the specific capsular polysaccharide of Streptococcus pneumoniae type 11F (American type 11)

1985 ◽  
Vol 63 (9) ◽  
pp. 953-968 ◽  
Author(s):  
James C. Richards ◽  
Malcolm B. Perry ◽  
Peter J. Kniskern
Keyword(s):  
Streptococcus Pneumoniae ◽  
Capsular Polysaccharide ◽  
Optical Rotation ◽  
Periodate Oxidation ◽  
Capsular Polysaccharides ◽  
Glycerol Phosphate ◽  
Part D ◽  
Magnetic Resonance Studies ◽  
Specific Polysaccharide ◽  
Structure Formula

The specific polysaccharide of Streptococcus pneumoniae type 11F (American type 11) is composed of 2-acetamido-2-deoxy-D-glucose (one part), D-glucose (one part), D-galactose (two parts), ribitol (one part), phosphate (one part), and O-acetyl (two parts). Hydrolysis, dephosphorylation, periodate oxidation, methylation, optical rotation, and 1H and 13C nuclear magnetic resonance studies showed that the polysaccharide is an unbranched linear polymer of a ribitol-phosphate substituted repeating tetrasaccharide unit having the structure:[Formula: see text]The specific capsular polysaccharides of S. pneumoniae type 11B and 11C (American types 76 and 53) were found to have the same tetrasaccharide repeating unit as the 11F polysaccharide, but differed from it in their mode of O-acetylation and the replacement of the ribitol phosphate by glycerol phosphate in the 11C specific polysaccharide.

scholarly journals Emergence of Multidrug-Resistant Pneumococcal Serotype 35B among Children in the United States

2016 ◽  
Vol 55 (3) ◽  
pp. 724-734 ◽  
Author(s):  
Liset Olarte ◽  
Sheldon L. Kaplan ◽  
William J. Barson ◽  
José R. Romero ◽  
Philana Ling Lin ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Pneumococcal Disease ◽  
Pediatric Patients ◽  
The United States ◽  
Multidrug Resistant ◽  
High Variability ◽  
Content Type ◽  
Pneumococcal Serotype ◽  
Genetic Events ◽  
Susceptibility Patterns

ABSTRACT Streptococcus pneumoniae serotype 35B is a nonvaccine serotype associated with high rates of penicillin nonsusceptibility. An increase in the proportion of multidrug-resistant (MDR) 35B isolates has recently been reported. The genetic events contributing to the emergence of MDR serotype 35B are unknown. The sequence type (ST) composition of 78 serotype 35B isolates obtained from pediatric patients with invasive pneumococcal disease from 1994 to 2014 and 48 isolates from pediatric patients with otitis media (noninvasive) from 2011 to 2014 was characterized by multilocus sequence typing (MLST). The most common STs were ST558 (69.2%), ST156 (10.3%), and ST452 (3.8%). Two major clonal complexes (CC), CC558 and CC156, were identified by eBURST analysis. Overall, 91% (71/78) of isolates were penicillin nonsusceptible and 16.7% (13/78) were MDR. Among all invasive serotype 35B isolates, MDR isolates increased significantly, from 2.9% (1/35) to 27.9% (12/43) ( P = 0.004), after the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced. All CC156 isolates were identified after the introduction of PCV13 (0/35 [0%] before versus 9/43 [20.9%] after; P = 0.003) and were MDR. All CC156 isolates had similar antimicrobial susceptibility patterns; in contrast, high variability in antimicrobial susceptibility was observed among CC558 isolates. The distributions of CC558 and CC156 among invasive and noninvasive isolates were not different. The increased prevalence of MDR serotype 35B after the introduction of PCV13 was directly associated with the emergence of ST156. Genotyping suggests that capsular switching has occurred between MDR vaccine serotypes belonging to ST156 (e.g., 9V, 14, and 19A) and serotype 35B.

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