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.

scholarly journals Reduced trans-placental transfer of group B Streptococcus surface protein antibodies in HIV-infected mother-newborn dyads

2016 ◽  
pp. jiw566
Author(s):  
Sonwabile Dzanibe ◽  
Peter V. Adrian ◽  
Sheila Z. Kimaro Mlacha ◽  
Ziyaad Dangor ◽  
Gaurav Kwatra ◽  
...  
Keyword(s):  
Placental Transfer ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Infected Mother ◽  
Group B

scholarly journals Acquisition of factor H by a novel surface protein on group B Streptococcus promotes complement degradation

2009 ◽  
Vol 23 (11) ◽  
pp. 3967-3977 ◽  
Author(s):  
Ravi Maruvada ◽  
Nemani V. Prasadarao ◽  
C. E. Rubens
Keyword(s):  
Group B Streptococcus ◽  
Surface Protein ◽  
Factor H ◽  
Group B

Association between maternal Group B Streptococcus surface-protein antibody concentrations and invasive disease in their infants

2015 ◽  
Vol 14 (12) ◽  
pp. 1651-1660 ◽  
Author(s):  
Ziyaad Dangor ◽  
Gaurav Kwatra ◽  
Alane Izu ◽  
Peter Adrian ◽  
Clare L Cutland ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Surface Protein ◽  
Invasive Disease ◽  
Group B

scholarly journals Protein rib: a novel group B streptococcal cell surface protein that confers protective immunity and is expressed by most strains causing invasive infections.

1993 ◽  
Vol 177 (6) ◽  
pp. 1593-1603 ◽  
Author(s):  
M Stålhammar-Carlemalm ◽  
L Stenberg ◽  
G Lindahl
Keyword(s):  
Cell Surface ◽  
Protective Immunity ◽  
Group B Streptococcus ◽  
Rabbit Antiserum ◽  
Surface Protein ◽  
Amino Acid Sequences ◽  
Cell Surface Protein ◽  
Type Iii ◽  
Invasive Infections ◽  
Group B

The group B Streptococcus, an important cause of invasive infections in the neonate, is classified into four major serotypes (Ia, Ib, II, and III) based on the structure of the polysaccharide capsule. Since the capsule is a known virulence factor, it has been extensively studied, in particular in type III strains, which cause the majority of invasive infections. Two cell surface proteins, alpha and beta, have also been studied in detail since they confer protective immunity, but these proteins are usually not expressed by type III strains. We describe here a cell surface protein, designated protein Rib (resistance to proteases, immunity, group B), that confers protective immunity and is expressed by most strains of type III. Protein Rib was first identified as a distinct 95-kD protein in extracts of a type III strain, and was purified to homogeneity from that strain. Rabbit antiserum to protein Rib was used to demonstrate that it is expressed on the cell surface of 31 out of 33 type III strains, but only on 1 out of 25 strains representing the other three serotypes. Mouse protection tests showed that antiserum to protein Rib protects against lethal infection with three different strains expressing this antigen, including a strain representing a recently identified high virulence type III clone. Protein Rib is immunologically unrelated to the alpha and beta proteins, but shares several features with the alpha protein. Most importantly, the NH2-terminal amino acid sequences of the Rib and alpha proteins are identical at 6 out of 12 positions. In addition, both protein Rib and the alpha protein are relatively resistant to trypsin (and Rib is also resistant to pepsin) and both proteins vary greatly in size between different clinical isolates. Finally, both protein Rib and the alpha protein exhibit a regular ladderlike pattern in immunoblotting experiments, which may reflect a repetitive structure. Taken together, these data suggest that the Rib and alpha proteins are members of a family of proteins with related structure and function. Since protein Rib confers protective immunity, it may be valuable for the development of a protein vaccine against the group B Streptococcus, an encapsulated bacterium.

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 MLST Application in Analysis of Relationship between Group B Streptococcus Resistance Gene and Induction Resistance in Shanghai, China

2020 ◽  
Author(s):  
Jing Gao ◽  
Yisheng Chen ◽  
Yiqian Peng ◽  
Nanyan Jiang ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Genes ◽  
Susceptibility Testing ◽  
Group B Streptococcus ◽  
Public Health Problem ◽  
Resistance Ratio ◽  
Diffusion Method ◽  
Relative Distribution ◽  
Slow Development ◽  
Group B

Abstract Background With the gradual severe bacterial resistance and slow development of antibiotics, drug-resistant bacterial strains are widely distributed and have become a serious public health problem. Group B Streptococcus (GBS) which cause Group B strep-related disease is the major cause of severe infection in newborns. However, Clindamycin resistance of GBS induced by Erythromycin is emerging and become important clinical concerns today. Methods A retrospective study was conducted on the drug resistance analysis of GBS strains isolated from Obstetrics and Gynecology Hospital from Jan 2016 to Dec 2017. The clinical and microbiological data including patient demographics, antimicrobial susceptibility testing, relative distribution drug resistance-associated genes mefA & ermB to Erythromycin, and multilocus sequence typing (MLST typing) were collected and analyzed. The Kirby-Bauer and VITEK2-compact were used to perform the susceptibility testing. The double disk diffusion method (D-test) was used for the detection of inducible clindamycin resistance. MLST was employed to identify sequence types of these strains. Polymerase Chain Reaction (PCR) was conducted to detect the drug resistance genes mefA & ermB to Erythromycin. Results A total of 1021 strains were cultured and isolated from 31894 specimens. Erythromycin and clindamycin resistance was 53.6%（547/1021）and 50.1 % (512/1021), respectively, in which 74.4%（407/547）had harbored constitutive macrolide, lincosamide and streptogramin B resistance (cMLS B ), 45.0%（63/140）were inducible MLS B (iMLS B ). Additionally, MLST identified 12 different ST types including a new ST type ST1072 in 63 iMLS B GBS strains and the dominant STs were ST12 (30.1%) and ST19 (25.4%). The resistance ratio of ST19 to Levofloxacin (75.0%) was higher than that of other ST types. The relevance resistance ratio of mefA and ermB was respectively 27.0% and 41.3% among 63 GBS isolates. Conclusion Our study not only demonstrated a genetic diversity in iMLS B GBS in Shanghai through the analysis of MLST typing and resistance genes, but also found that there exist different distribution patterns of resistance and related resistance genes between different ST types. These findings would provide theoretical support for clinical prevention and treatment of resistant iMLS B GBS infection.

scholarly journals Response of Group B Streptococcus to the Combination of Gold Nanoparticles-Erythromycin as a Nanoweapon

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Leila Fozouni ◽  
Prastoo Vaezi ◽  
Ania Ahani Azari
Keyword(s):  
Gold Nanoparticles ◽  
Pregnant Women ◽  
Rural Areas ◽  
Group B Streptococcus ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Wide Range ◽  
Broth Microdilution Method ◽  
Group B

Background: Group B Streptococcus (GBS) causes a wide range of adverse effects in both mothers and infants during pregnancy and after delivery. Objectives: This study aimed to evaluate the effects of erythromycin either alone or in combination with gold nanoparticles (AuNPs) on the clinical GBS isolated from pregnant women. Methods: This descriptive cross-sectional study was performed on 106 women aged 16 - 48 years. After identification of GBS strains by phenotypic and genotypic methods (PCR), erythromycin-resistant isolates were identified using the Kirby-Bauer test and broth microdilution method according to CLSI-2015 guidelines. The antibacterial properties and minimum inhibitory concentration (MIC) of erythromycin (either alone or combined with AuNPs) were assessed by the agar well-diffusion and broth microdilution methods, respectively. Results: The frequency of GBS isolates was significantly high in the pregnant women aged less than 40 years (73.9%) (P = 0.0251), those with a history of abortion (60.9%) (P = 0.038), and residents of rural areas (60%) (P = 0.038). Moreover, 65.2% of the isolates were resistant to erythromycin. The MIC of AuNPs-erythromycin combination required to inhibit the growth of 50% of GBS isolates (MIC50 = 0.25 μg/mL) was significantly lower than the concentration of AuNP-erythromycin required to inhibit the growth of 90% of the isolates (MIC90 = 1 μg/mL) (P = 0.02), indicating a 16-fold lower dose than the values for erythromycin and AuNPs alone. In the agar well-diffusion method, the average diameter of the growth inhibition zone of AuNPs-erythromycin was 2.5-fold greater than that of free erythromycin (P = 0.037). Conclusions: The results showed that the combination of erythromycin with AuNPs increased the antibacterial effects of erythromycin against GBS isolates.

scholarly journals Perinatal hormones favor CC17 group B Streptococcus intestinal translocation through M cells and hypervirulence in neonates

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Constantin Hays ◽  
Gérald Touak ◽  
Abdelouhab Bouaboud ◽  
Agnès Fouet ◽  
Julie Guignot ◽  
...  
Keyword(s):  
Late Onset ◽  
Group B Streptococcus ◽  
Intestinal Barrier ◽  
Surface Protein ◽  
Neonatal Infection ◽  
M Cells ◽  
M Cell ◽  
Hormonal Exposure ◽  
Group B ◽  
The Impact

Group B Streptococcus (GBS) is the leading cause of invasive bacterial neonatal infections. Late-onset diseases (LOD) occur between 7 and 89 days of life and are largely due to the CC17 GBS hypervirulent clone. We studied the impact of estradiol (E2) and progesterone (P4), which impregnate the fetus during pregnancy, on GBS neonatal infection in cellular and mouse models of hormonal exposure corresponding to concentrations found at birth (E2-P4 C0) and over 7 days old (E2-P4 C7). Using representative GBS isolates, we show that E2-P4 C7 concentrations specifically favor CC17 GBS meningitis following mice oral infection. CC17 GBS crosses the intestinal barrier through M cells. This process mediated by the CC17-specific surface protein Srr2 is enhanced by E2-P4 C7 concentrations which promote M cell differentiation and CC17 GBS invasiveness. Our findings provide an explanation for CC17 GBS responsibility in LOD in link with neonatal gastrointestinal tract maturation and hormonal imprint.

scholarly journals Reverse Line Blot Assay for Direct Identification of Seven Streptococcus agalactiae Major Surface Protein Antigen Genes

2006 ◽  
Vol 13 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Zuotao Zhao ◽  
Fanrong Kong ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Streptococcus Agalactiae ◽  
Blot Hybridization ◽  
Group B Streptococcus ◽  
Immunoglobulin A ◽  
Surface Protein ◽  
Epidemiological Studies ◽  
Reverse Line Blot ◽  
Variable Surface ◽  
Group B ◽  
Major Surface

ABSTRACT We developed a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB) to detect the genes encoding members of the family of variable surface-localized proteins of Streptococcus agalactiae (group B streptococcus [GBS]), namely, Bca (Cα), Rib, Epsilon (Epsilon/Alp1/Alp5), Alp2, Alp3, and Alp4, and the immunoglobulin A binding protein, Bac (Cβ). We used the assay to identify these genes in a collection of well-characterized GBS isolates and reference strains. The results showed that mPCR/RLB avoids the common problems of cross-reaction and nontypability associated with protein typing using antisera. It is as sensitive as, but more practical than, separate gene-specific PCRs and would be suitable for large molecular epidemiological studies of GBS.

scholarly journals Intranasal Immunization of Mice with Group B Streptococcal Protein Rib and Cholera Toxin B Subunit Confers Protection against Lethal Infection

2004 ◽  
Vol 72 (2) ◽  
pp. 1184-1187 ◽  
Author(s):  
Charlotte Larsson ◽  
Jan Holmgren ◽  
Gunnar Lindahl ◽  
Charlotta Bergquist
Keyword(s):  
Cholera Toxin ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Cholera Toxin B Subunit ◽  
Toxin B ◽  
Intranasal Immunization ◽  
Cholera Toxin B ◽  
B Subunit ◽  
A Cell ◽  
Group B

ABSTRACT Intranasal immunization of mice with Rib, a cell surface protein of group B streptococcus (GBS), conjugated to or simply coadministered with the recombinant cholera toxin B subunit, induces systemic immunoglobulin G (IgG) and local IgA antibody responses and confers protection against lethal GBS infection. These findings have implications for the development of a human GBS vaccine.

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