scholarly journals Group B Streptococcal Surface Proteins as Targets for Protective Antibodies: Identification of Two Novel Proteins in Strains of Serotype V

1999 ◽  
Vol 67 (12) ◽  
pp. 6350-6357 ◽  
Author(s):  
Thomas Areschoug ◽  
Margaretha Stålhammar-Carlemalm ◽  
Charlotte Larsson ◽  
Gunnar Lindahl
Keyword(s):  
Vaccine Development ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Cross Reactivity ◽  
Active Immunization ◽  
Surface Proteins ◽  
Protective Antibodies ◽  
Group B ◽  
Different Strains ◽  
Type V

ABSTRACT Strains of group B streptococcus (GBS) express surface proteins that confer protective immunity. In particular, most strains of the four classical capsular serotypes (Ia, Ib, II, and III) express either of the Rib and α proteins, two members of the same protein family. Here, we report a study of surface proteins expressed by strains of serotype V, which has recently emerged as an important serotype among GBS strains causing serious disease. Two novel GBS proteins were identified, purified, and characterized. One of these proteins, designated Fbs, was immunologically unrelated to other GBS surface proteins. This ∼110-kDa protein was found in 15 of 49 (31%) type V isolates but in few strains of other serotypes. The Fbs proteins expressed by different strains showed limited variation in size. The most common surface protein among type V strains, found in 29 of 49 (59%) isolates, was designated Rib-like, since it cross-reacted with Rib but was not immunologically identical to Rib. Characterization of this Rib-like protein showed that the N-terminal sequence (12 residues) was identical to that of α, although these two proteins lacked cross-reactivity. The biochemical and immunological properties of the Rib-like GBS protein indicate that it is closely related to the R28 protein of Streptococcus pyogenes. Importantly, passive and active immunization experiments with mice showed that the Fbs and Rib-like proteins are targets for protective antibodies. These two proteins are therefore of interest for analysis of pathogenic mechanisms and for vaccine development.

scholarly journals Identification of novel cps locus polymorphisms in nontypable group B Streptococcus

2006 ◽  
Vol 55 (6) ◽  
pp. 775-783 ◽  
Author(s):  
Srinivas V. Ramaswamy ◽  
Patricia Ferrieri ◽  
Lawrence C. Madoff ◽  
Aurea E. Flores ◽  
Nikhil Kumar ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
The Elderly ◽  
Surface Proteins ◽  
Pcr Analysis ◽  
Genetic Profile ◽  
Gene Encoding ◽  
Group B ◽  
Type V

Group B Streptococcus (GBS) is an important pathogen responsible for a variety of diseases in newborns and the elderly. A clinical GBS isolate is considered nontypable (NT) when serological methods fail to identify it as one of nine known GBS serotypes. Eight clinical isolates (designated A1–A4, B1–B4) showed PFGE profiles similar to that of a GBS serotype V strain expressing R1, R4 surface proteins. These unique isolates were further characterized by immunologic and genetic methods. Rabbit sera to isolates A1 and A2 reacted weakly with concentrated HCl extracts of A1–A4 isolates, but not with those of B1–B4 isolates. In addition, a type V capsular polysaccharide (CPS) inhibition ELISA revealed that cell wall extracts from isolates A1–A4, but not from B1–B4, expressed low but measurable amounts of type V CPS. Molecular serotyping with PCR analysis showed that all eight isolates contained a type V-specific CPS gene (cpsO) and harboured the gene encoding the surface protein Alp3. Multilocus sequence typing identified isolate A1 as belonging to a new sequence type (ST) designated ST-173, whereas the other seven isolates keyed to ST-1. Sequencing of the 18 genes (17 736 bp) in the cps locus showed that each NT isolate harboured one to three unique polymorphisms, and also identified an IS1381 element in cpsE of the B4 isolate. Collectively, genetic and immunologic analyses revealed that these NT isolates expressing R1, R4 proteins have a genetic profile consistent with that of type V, an emergent, antigenically diverse and increasingly prevalent GBS serotype.

scholarly journals Protection from Group B Streptococcal Infection in Neonatal Mice by Maternal Immunization with Recombinant Sip Protein

2002 ◽  
Vol 70 (9) ◽  
pp. 4897-4901 ◽  
Author(s):  
Denis Martin ◽  
Stéphane Rioux ◽  
Edith Gagnon ◽  
Martine Boyer ◽  
Josée Hamel ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Neonatal Infection ◽  
Active Immunization ◽  
Infection Model ◽  
Lethal Challenge ◽  
Specific Antibodies ◽  
Pregnant Mice ◽  
Group B

ABSTRACT The protective potential of antibodies directed against group B streptococcus (GBS) Sip surface protein was determined by using the mouse neonatal infection model. Rabbit Sip-specific antibodies administered passively to pregnant mice protected their pups against a GBS lethal challenge. In addition, active immunization with purified recombinant Sip protein of female CD-1 mice induced the production of specific antibodies that also confer protection to the newborn pups against GBS strains of serotypes Ia/c, Ib, II, III, and V. These data confirm that Sip-specific antibodies can cross the placenta and conferred protective immunity against GBS infections.

scholarly journals The Proline-Rich Region of Pneumococcal Surface Proteins A and C Contains Surface-Accessible Epitopes Common to All Pneumococci and Elicits Antibody-Mediated Protection against Sepsis

2010 ◽  
Vol 78 (5) ◽  
pp. 2163-2172 ◽  
Author(s):  
Calvin C. Daniels ◽  
Patricia Coan ◽  
Janice King ◽  
Joanetha Hale ◽  
Kimberly A. Benton ◽  
...  
Keyword(s):  
Protein A ◽  
Pneumococcal Infection ◽  
Passive Immunization ◽  
Surface Protein ◽  
Helical Structure ◽  
Structural Similarity ◽  
Cross Reactivity ◽  
Surface Proteins ◽  
Structure Characteristic ◽  
Protective Antibodies

ABSTRACTPneumococcal surface protein A (PspA) and PspC ofStreptococcus pneumoniaeare surface virulence proteins that interfere with complement deposition and elicit protective immune responses. The C-terminal halves of PspA and PspC have some structural similarity and contain highly cross-reactive proline-rich (PR) regions. In many PR regions of PspA and PspC, there exists an almost invariant nonproline block (NPB) of about 33 amino acids. Neither the PR regions nor their NPB exhibit the alpha-helical structure characteristic of much of the protection-eliciting N-terminal portions of PspA and PspC. Prior studies of PspA and PspC as immunogens focused primarily on the alpha-helical regions of these molecules that lack the PR and NPB regions. This report shows that immunization with recombinant PR (rPR) molecules and passive immunization with monoclonal antibodies reactive with either NPB or PR epitopes are protective against infection in mice. PR regions of both PspA and PspC were antibody accessible on the pneumococcal surface. Our results indicate that while PspA could serve as a target of these protective antibodies in invasive infections, PspC might not. When antibody responses to rPR immunogens were evaluated by using flow cytometry to measure antibody binding to live pneumococci, it was observed that the mice that survived subsequent challenge produced significantly higher levels of antibodies reactive with exposed PR epitopes than the mice that became moribund. Due to their conservation and cross-reactivity, the PR regions and NPB regions represent potential vaccine targets capable of eliciting cross-protection immunity against pneumococcal infection.

scholarly journals Evaluation of Recombinant Lipidated P2086 Protein as a Vaccine Candidate for Group B Neisseria meningitidis in a Murine Nasal Challenge Model

2005 ◽  
Vol 73 (10) ◽  
pp. 6838-6845 ◽  
Author(s):  
Duzhang Zhu ◽  
Ying Zhang ◽  
Vicki Barniak ◽  
Liesel Bernfield ◽  
Alan Howell ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Vaccine Candidate ◽  
Active Immunization ◽  
Human Beings ◽  
Nasal Tissue ◽  
Potential Vaccine ◽  
Group B ◽  
Different Strains

ABSTRACT Neisseria meningitidis is a major causative agent of bacterial meningitis in human beings, especially among young children (≤2 years of age). Prevention of group B meningococcal disease represents a particularly difficult challenge in vaccine development, due to the inadequate immune response elicited against type B capsular polysaccharide. We have established an adult mouse intranasal challenge model for group B N. meningitidis to evaluate potential vaccine candidates through active immunization. Swiss Webster mice were inoculated intranasally with meningococci, and bacteria were recovered from the noses for at least 3 days postchallenge. Iron dextran was required in the bacterial inoculum to ensure sufficient meningococcal recovery from nasal tissue postchallenge. This model has been utilized to evaluate the potential of a recombinant lipidated group B meningococcal outer membrane protein P2086 (rLP2086) as a vaccine candidate. In this study, mice were immunized subcutaneously with purified rLP2086 formulated with or without an attenuated cholera toxin as an adjuvant. The mice were then challenged intranasally with N. meningitidis strain H355 or M982, and the colonization of nasal tissue was determined by quantitative culture 24 h postchallenge. We demonstrated that immunization with rLP2086 significantly reduced nasal colonization of mice challenged with the two different strains of group B N. meningitidis. Mice immunized with rLP2086 produced a strong systemic immunoglobulin G response, and the serum antibodies were cross-reactive with heterologous strains of group B N. meningitidis. The antibodies have functional activity against heterologous N. meningitidis strain, as demonstrated via bactericidal and infant rat protection assays. These results suggest that rLP2086 is a potential vaccine candidate for group B N. meningitidis.

scholarly journals Antigenic Determinants of Alpha-Like Proteins of Streptococcus agalactiae

2004 ◽  
Vol 11 (6) ◽  
pp. 1035-1039 ◽  
Author(s):  
Johan A. Maeland ◽  
Lars Bevanger ◽  
Randi Valsoe Lyng
Keyword(s):  
Western Blotting ◽  
Antigenic Determinant ◽  
Fluorescent Antibody ◽  
Group B Streptococcus ◽  
Antigenic Site ◽  
Antibody Test ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Protective Antibodies ◽  
Group B

ABSTRACT The majority of group B streptococcus (GBS) isolates express one or more of a family of surface-anchored proteins that vary by strain and that form ladder-like patterns on Western blotting due to large repeat units. These proteins, which are important as GBS serotype markers and as inducers of protective antibodies, include the alpha C (Cα) and R4 proteins and the recently described alpha-like protein 2 (Alp2), encoded by alp2, and Alp3, encoded by alp3. In this study, we examined antigenic determinants possessed by Alp2 and Alp3 by testing of antibodies raised in rabbits, mainly by using enzyme-linked immunosorbent assays (ELISA) and an ELISA absorption test. The results showed that Alp2 and Alp3 shared an antigenic determinant, which may be a unique immunological marker of the Alp variants of GBS proteins. Alp2, in addition, possessed an antigenic determinant which showed specificity for Alp2 and a third determinant which showed serological cross-reactivity with Cα. Alp3, in addition to the determinant common to Alp2 and Alp3, harbored an antigenic site which also was present in the R4 protein, whereas no Alp3-specific antigenic site was detected. These ELISA-based results were confirmed by Western blotting and a fluorescent-antibody test. The results are consistent with highly complex antigenic structures of the alpha-like proteins in a fashion which is in agreement with the recently described structural mosaicism of the alp2 and alp3 genes. The results are expected to influence GBS serotyping, immunoprotection studies, and GBS vaccine developments.

Serotype and surface protein gene distribution of colonizing group B streptococcus in women in Egypt

2013 ◽  
Vol 142 (1) ◽  
pp. 208-210 ◽  
Author(s):  
S. SHABAYEK ◽  
S. ABDALLA ◽  
A. MH. ABOUZEID
Keyword(s):  
High Frequency ◽  
Protein Gene ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Surface Proteins ◽  
Protein Encoding ◽  
Vaginal Swabs ◽  
Surface Protein Gene ◽  
Group B ◽  
Encoding Genes

SUMMARYGroup B streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis. We determined the distribution of serotypes and surface protein encoding genes of GBS strains from pregnant and non-pregnant women in Egypt. Vaginal swabs from 364 women were screened by culture and 100 (27·4%) yielded GBS. Serotype V was the most predominant (33%), followed by serotypes II (17%), III (15%), Ia (14%), VI (12%), Ib (8%) and IV (1%). The most common surface protein genes were epsilon (27%), alp3 (26%), bca (18%), rib (16%) and alp2 (10%). Two isolates were negative for surface protein genes. The distribution of serotypes and surface proteins was similar to reports from other parts of the world but the relatively high frequency of serotype VI was a notable feature of the strains from women in Egypt.

scholarly journals Antibody against Surface-Bound C5a Peptidase Is Opsonic and Initiates Macrophage Killing of Group B Streptococci

2001 ◽  
Vol 69 (4) ◽  
pp. 2302-2308 ◽  
Author(s):  
Qi Cheng ◽  
Brian Carlson ◽  
Sub Pillai ◽  
Ron Eby ◽  
Lorri Edwards ◽  
...  
Keyword(s):  
Whole Blood ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Primary Cultures ◽  
Surface Protein ◽  
Mouse Bone Marrow ◽  
Group B Streptococci ◽  
Protective Antibodies ◽  
Group B

ABSTRACT The capsular polysaccharides of group B streptococci (GBS) are a primary focus of vaccine development. Immunogenicity and long-lasting protection are best achieved by conjugating polysaccharides to a T-cell-dependent protein antigen. Streptococcal C5a peptidase (SCPB) is a conserved surface protein that is expressed by all streptococcal serotypes tested to date, and it is a possible carrier protein that could itself induce a protective immune response. Clearance of GBS from lungs, mucosal surfaces, or blood probably depends on the opsonophagocytic response of tissue-specific macrophages and polymorphonuclear leukocytes (PMNs). In this study, we examined the potential of antibody directed against SCPB from a serotype II strain to enhance the capacity of mouse bone marrow macrophages (from primary cultures) and human PMNs in whole blood to kill GBS in vitro. Our experiments demonstrated that Streptococcus serotypes Ia, Ib, II, III, and V, preopsonized with anti-SCPB antibody, were killed more rapidly by cultured macrophages and PMNs in whole blood than were nonopsonized GBS. The increased rate of killing was accompanied by an increased macrophage oxidative burst. Furthermore, opsonization was serotype transparent. Immunization with SCPB conjugated to capsular polysaccharide type III produced polysaccharide-specific antibodies. It is interesting that this antiserum promoted serotype-independent killing of streptococci. These data support the use of SCPB in a GBS polysaccharide conjugate vaccine. SCPB not only enhanced the immunogenicity of polysaccharide components of the vaccine, but it might also induce additional serotype-independent protective antibodies.

scholarly journals High prevalence of group B streptococcus ST17 hypervirulent clone among non-pregnant patients from a Hungarian venereology clinic

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Szilvia Kardos ◽  
Adrienn Tóthpál ◽  
Krisztina Laub ◽  
Katalin Kristóf ◽  
Eszter Ostorházi ◽  
...  
Keyword(s):  
Genetic Relatedness ◽  
Clinical Symptoms ◽  
Strong Association ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Surface Proteins ◽  
High Prevalence ◽  
Intrapartum Antibiotic ◽  
Group B ◽  
Open Question

Abstract Background Although Streptococcus agalactiae is the leading causative agent of neonatal sepsis and meningitis, recently it is increasingly isolated from non-pregnant adults. The relation between its presence in the genitourinary tract and manifested clinical symptoms of STD patients remains an open question. In this study, a complex epidemiological investigation of GBS isolates from a venerology clinic was performed. Methods Ninety-six GBS isolates were serotyped and their genetic relatedness determined by PFGE. MLST was also performed for a subset of 20 isolates. The antibiotic susceptibility was tested with agar dilution. Surface proteins and the ST-17 hypervirulent clone was detected by PCR. Results The serotype prevalence was the following: V (29.2%), III (27.1%), Ia (22.9%), IV (10.4%), II (5.2%) and Ib (4.2%). A strong association was demonstrated between surface protein genes and serotypes. All isolates were fully susceptible to penicillin, but erythromycin and clindamycin resistance was high (41.7 and 35.4%, respectively), and 8 phenotypically macrolide sensitive isolates carried the ermB gene. 21.9% of all strains belonged to the hypervirulent ST17 clone, most being of serotype III and all were rib +. We found a few serotype IV isolates belonging to several STs and one serotype V/ST110 strain, containing a 44-bp deletion in the atr allele. Conclusions The presence of silent ermB genes is of worry, as their expression upon macrolide exposure could lead to unforeseen therapeutic failure, while clindamycin is used for intrapartum antibiotic prophylaxis, in case of penicillin allergy. The other alarming result is the high prevalence of ST17 among these strains from STD patients, who could be sources of further infections. This is the first report from Hungary providing both serotyping and genotyping data of GBS isolates. These results could be helpful for vaccine production as the major vaccine candidates are capsular antigens or surface proteins.

scholarly journals Genetic characterization and diversity of Streptococcus agalactiae isolates with macrolide resistance

2010 ◽  
Vol 59 (7) ◽  
pp. 780-786 ◽  
Author(s):  
Monika Brzychczy-Włoch ◽  
Tomasz Gosiewski ◽  
Małgorzata Bodaszewska ◽  
Wojciech Pabian ◽  
Małgorzata Bulanda ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Macrolide Resistance ◽  
Surface Proteins ◽  
Erythromycin Resistance ◽  
High Genetic Diversity ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Group B

Macrolide resistance in 169 Streptococcus agalactiae [group B streptococcus (GBS)] isolates originating from pregnant carriers was investigated. Using multiplex PCR the presence of genes encoding erythromycin resistance and capsular polysaccharides, as well as surface proteins, was determined. Random amplification of polymorphic DNA (RAPD) and PFGE were used to characterize specific clones among the isolates. In the examined population of women, erythromycin-resistant strains were found in 4.5 % of patients, whereas clindamycin-resistant strains were found in 3 % of patients, which was 16 % of strains resistant to erythromycin and 10 % of strains resistant to clindamycin among GBS isolates, respectively. Among the isolates, the largest percentage was represented by the constitutive macrolide–lincosamide–streptogramin B (cMLSB) phenotype (63 %), then the inductive macrolide–lincosamide–streptogramin B (iMLSB) phenotype (26 %) and the macrolide resistance (M) phenotype (11 %). The ermB gene was indicated in all isolates with the cMLSB phenotype and V serotype, whereas mefA/mefE genes were found in isolates with the M phenotype and Ia serotype. Among resistance isolates, serotype V was predominant (67 %), followed by serotypes II (15 %), Ia (11 %) and III (7 %). The most common surface protein encoding genes were alp3 (70 %), then rib (11 %), epsilon (7.5 %), bca (7.5 %) and alp2 (4 %). A statistically significant relationship between macrolide resistance, serotype V and the alp3 gene was demonstrated. PFGE, in comparison to the RAPD method, gave better genetic discrimination of GBS isolates. A relatively high genetic diversity among investigated strains was shown. In addition, the largest genetic homogeneity was found in serotype V.

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of glyceraldehyde-3-phosphate dehydrogenase fromStreptococcus agalactiaeNEM316

2014 ◽  
Vol 70 (7) ◽  
pp. 938-941 ◽  
Author(s):  
Revathi Nagarajan ◽  
Karthe Ponnuraj
Keyword(s):  
Signal Sequence ◽  
Structure Refinement ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Diffusion Method ◽  
Space Groups ◽  
Essential Enzyme ◽  
Bacteria And Fungi ◽  
Group B ◽  
Surface Adhesins

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential enzyme involved in glycolysis. Despite lacking the secretory signal sequence, this cytosolic enzyme has been found localized at the surface of several bacteria and fungi. As a surface protein, GAPDH exhibits various adhesive functions, thereby facilitating colonization and invasion of host tissues.Streptococcus agalactiae, also known as group B streptococcus (GBS), binds onto the host using its surface adhesins and causes sepsis and pneumonia in neonates. GAPDH is one of the surface adhesins of GBS binding to human plasminogen and is a virulent factor associated with host colonization. Although the surface-associated GAPDH has been shown to bind to a variety of host extracellular matrix (ECM) molecules in various bacteria, the molecular mechanism underlying their interaction is not fully understood. To investigate this, structural studies on GAPDH ofS. agalactiaewere initiated. ThegapCgene ofS. agalactiaeNEM316 encoding GAPDH protein was cloned into pET-28a vector, overexpressed inEscherichia coliBL21(DE3) cells and purified to homogeneity. The purified protein was crystallized using the hanging-drop vapour-diffusion method. The GAPDH crystals obtained in two different crystallization conditions diffracted to 2.8 and 2.6 Å resolution, belonging to two different space groupsP21andP212121, respectively. The structure was solved by molecular replacement and structure refinement is now in progress.

Sign in / Sign up

Export Citation Format

Share Document