scholarly journals Mouse IgG2a antibodies specific for the commensal Streptococcus mitis show stronger cross-reactivity with Streptococcus pneumoniae than IgG1 antibodies

2019 ◽  
Author(s):  
Sudhanshu Shekhar ◽  
Rabia Khan ◽  
Ata Ul Razzaq Khan ◽  
Fernanda Cristina Petersen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Cross Reactivity ◽  
Pneumococcal Infections ◽  
Streptococcus Mitis ◽  
The Cross ◽  
Mouse Igg2a

AbstractHere we show that mouse IgG2a and IgG1 antibodies specific for the commensal Streptococcus mitis cross-react with the pathogen Streptococcus pneumoniae, although the cross-reactivity conferred by IgG2a is stronger than IgG1 antibodies. These findings may have implications for designing S. mitis-based vaccines against pneumococcal infections.

scholarly journals Mouse IgG2a Antibodies Specific for the Commensal Streptococcus mitis Show Stronger Cross-Reactivity with Streptococcus pneumoniae than IgG1 Antibodies

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Sudhanshu Shekhar ◽  
Rabia Khan ◽  
Ata Ul Razzaq Khan ◽  
Fernanda Cristina Petersen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pneumococcal Vaccine ◽  
Cross Reactivity ◽  
Streptococcus Mitis ◽  
The Cross ◽  
Mouse Igg2a

Here we show that mouse IgG2a and IgG1 antibodies specific for the commensal Streptococcus mitis cross-react with pathogen Streptococcus pneumoniae serotypes 2 and 4, although the cross-reactivity conferred by IgG2a is stronger than that by IgG1 antibodies. These findings may be important for understanding the S. mitis-induced IgG isotype responses and have consequences for the development of an effective pneumococcal vaccine.

scholarly journals Antibodies Reactive to Commensal Streptococcus mitis Show Cross-Reactivity With Virulent Streptococcus pneumoniae Serotypes

2018 ◽  
Vol 9 ◽  
Author(s):  
Sudhanshu Shekhar ◽  
Rabia Khan ◽  
Daniela M. Ferreira ◽  
Elena Mitsi ◽  
Esther German ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Cross Reactivity ◽  
Streptococcus Mitis

Structural elucidation of the capsular polysaccharide of Streptococcus pneumoniae type 9N

1983 ◽  
Vol 61 (10) ◽  
pp. 1102-1107 ◽  
Author(s):  
Karl-Gunnar Rosell ◽  
Harold J. Jennings
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Streptococcus Pneumoniae ◽  
Magnetic Resonance ◽  
Capsular Polysaccharide ◽  
Glucuronic Acid ◽  
Cross Reactivity ◽  
Structural Elucidation ◽  
Molar Ratio ◽  
The Cross ◽  
Nuclear Magnetic

The specific capsular polysaccharide of Streptococcus pneumoniae type 9N (American type 9) contains D-glucose, D-glucuronic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-mannose in the molar ratio of 2:1:1:1. Accumulated data from spectroscopic (13C and 1H nuclear magnetic resonance) and methylation analyses of the native and specifically degraded polysaccharide indicated that it was linear and composed of the following pentasaccharide repeating unit; —4)-α-D-GlcpA-(1 → 3)-α-D-Glcp-(1 → 3)-β-D-ManpNAc-(1 → 4)-α-D-Glcp-(1 → 4)-β-D-GlcpNAc(1 →. Structural regions in the type 9N polysaccharide common to those of types 9A, 9L, and 9V have been identified which account for the cross-reactivity of this groups of polysaccharides.

scholarly journals Analysis of Serum Cross-Reactivity and Cross-Protection Elicited by Immunization with DNA Vaccines against Streptococcus pneumoniae Expressing PspA Fragments from Different Clades

2002 ◽  
Vol 70 (9) ◽  
pp. 5086-5090 ◽  
Author(s):  
Eliane N. Miyaji ◽  
Daniela M. Ferreira ◽  
Alexandre P. Y. Lopes ◽  
M. Cristina C. Brandileone ◽  
Waldely O. Dias ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Dna Vaccines ◽  
Protein A ◽  
Sequence Divergence ◽  
Surface Protein ◽  
Cost Effective ◽  
Cross Reactivity ◽  
Cross Protection ◽  
The Cross ◽  
Humoral Responses

ABSTRACT Streptococcus pneumoniae is a major cause of disease, especially in developing countries, and cost-effective alternatives to the currently licensed vaccines are needed. We constructed DNA vaccines based on pneumococcal surface protein A (PspA), an antigen shown to induce protection against pneumococcal bacteremia. PspA fragments can be divided into three families, which can be subdivided into six clades, on the basis of PspA amino acid sequence divergence (S. K. Hollingshead, R. Becker, and D. E. Briles, Infect. Immun. 68:5889-5900, 2000). Since most clinical isolates belong to family 1 or family 2, PspA fragments from members of both of these families were analyzed. Vectors encoding the complete N-terminal regions of PspAs elicited significant humoral responses, and cross-reactivity was mainly restricted to the same family. DNA vaccines encoding fusions between PspA fragments from family 1 and family 2 were also constructed and were able to broaden the cross-reactivity, with induction of antibodies that showed reactions with members of both families. At least for the pneumococcal strains tested, the cross-reactivity of antibodies was not reflected in cross-protection. Animals immunized with DNA vaccines expressing the complete N-terminal regions of PspA fragments were protected only against intraperitoneal challenge with a strain expressing PspA from the same clade.

scholarly journals Peptide Mimic of Phosphorylcholine, a Dominant Epitope Found on Streptococcus pneumoniae

2000 ◽  
Vol 68 (10) ◽  
pp. 5778-5784 ◽  
Author(s):  
Shannon L. Harris ◽  
Moon K. Park ◽  
Moon H. Nahm ◽  
Betty Diamond
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Binding Site ◽  
The Elderly ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Pneumococcal Infections ◽  
Amino Acid Region ◽  
Peptide Mimic ◽  
Idiotypic Interaction

ABSTRACT Even in the age of antibiotics, Streptococcus pneumoniae causes significant morbidity, especially in the young, the elderly, and the immunocompromised. While a carbohydrate-based vaccine exists, it is poorly immunogenic in the at-risk populations. In mice, antibodies directed against phosphorylcholine (PC), an epitope present on the cell wall C polysaccharide of all pneumococcal serotypes, protect against infection. However, PC itself is a poor vaccine candidate. We report here peptide mimics of PC based on the anti-idiotypic interaction of T15 anti-PC antibodies. T15 antibodies, the dominant and protective idiotype induced in mice by PC immunization, self-associate via a 24-amino-acid region in the PC binding site (ASRNKANDYTTEYSASVKGRFIVS; peptide 1). Peptide 1 has been shown to bind in the PC binding site. We demonstrated that amino acid sequences derived from peptide 1 starting at amino acid 9, 11, or 13 inhibit PC binding. Therefore, we immunized mice with bovine serum albumin (BSA) conjugates of peptide 1 or either of two selected 12-mers. The 12-mer peptides were not immunogenic. Mice immunized with peptide 1-BSA developed an anti-PC response consisting mainly immunoglobulin G1 and expressed the T15 heavy chain. Nonetheless, neither BALB/c nor CBA/N mice were protected from lethal pneumococcal infections by immunization with peptide 1-BSA. Preliminary data suggest that peptide 1-BSA is not able to elicit the canonical T15 light chain, explaining the absence of protection. This idiotype-derived mimotope of PC is a useful tool for understanding immunologic cross-reactivity and learning to design T-cell-dependent vaccines for S. pneumoniae.

scholarly journals Antimicrobial resistance profile and multidrug resistance patterns of Streptococcus pneumoniae isolates from patients suspected of pneumococcal infections in Ethiopia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Bekele Sharew ◽  
Feleke Moges ◽  
Gizachew Yismaw ◽  
Wondwossen Abebe ◽  
Surafal Fentaw ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Streptococcus Pneumoniae ◽  
Antimicrobial Resistance ◽  
Addis Ababa ◽  
Pneumococcal Infection ◽  
Test Method ◽  
Resistance Testing ◽  
Global Public Health ◽  
Pneumococcal Infections ◽  
Resistance Patterns

Abstract Background Antimicrobial-resistant strains of Streptococcus pneumoniae have become one of the greatest challenges to global public health today and inappropriate use of antibiotics and high level of antibiotic use is probably the main factor driving the emergence of resistance worldwide. The aim of this study is, therefore, to assess the antimicrobial resistance profiles and multidrug resistance patterns of S. pneumoniae isolates from patients suspected of pneumococcal infections in Ethiopia. Methods A hospital-based prospective study was conducted from January 2018 to December 2019 at Addis Ababa city and Amhara National Region State Referral Hospitals. Antimicrobial resistance tests were performed from isolates of S. pneumoniae that were collected from pediatric and adult patients. Samples (cerebrospinal fluid, blood, sputum, eye discharge, ear discharge, and pleural and peritoneal fluids) from all collection sites were initially cultured on 5% sheep blood agar plates and incubated overnight at 37 °C in a 5% CO2 atmosphere. Streptococcus pneumoniae was identified and confirmed by typical colony morphology, alpha-hemolysis, Gram staining, optochin susceptibility, and bile solubility test. Drug resistance testing was performed using the E-test method according to recommendations of the Clinical and Laboratory Standards Institute. Results Of the 57 isolates, 17.5% were fully resistant to penicillin. The corresponding value for both cefotaxime and ceftriaxone was 1.8%. Resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole were 59.6%, 17.5%, 38.6%, 17.5 and 24.6%, respectively. Multidrug resistance (MDR) was seen in 33.3% isolates. The most common pattern was co-resistance to penicillin, erythromycin, clindamycin, and tetracycline. Conclusions Most S. pneumoniae isolates were susceptible to ceftriaxone and cefotaxime. Penicillin has been used as a drug of choice for treating S. pneumoniae infection. However, antimicrobial resistance including multidrug resistance was observed to several commonly used antibiotics including penicillin. Hence, it is important to periodically monitor the antimicrobial resistance patterns to select empirical treatments for better management of pneumococcal infection.

scholarly journals Performance of the Vitek MS v2.0 System in Distinguishing Streptococcus pneumoniae from Nonpneumococcal Species of the Streptococcus mitis Group

2013 ◽  
Vol 51 (9) ◽  
pp. 3079-3082 ◽  
Author(s):  
J. A. Branda ◽  
R. P. Markham ◽  
C. D. Garner ◽  
J. A. Rychert ◽  
M. J. Ferraro
Keyword(s):  
Streptococcus Pneumoniae ◽  
Streptococcus Mitis ◽  
Vitek Ms

Prolonged Pneumococcal Meningitis Due to an Organism With Increased Resistance to Penicillin

PEDIATRICS ◽  
1976 ◽  
Vol 58 (3) ◽  
pp. 378-381 ◽  
Author(s):  
Abel Paredes ◽  
Larry H. Taber ◽  
Martha D. Yow ◽  
Dorothy Clark ◽  
William Nathan
Keyword(s):  
Case Report ◽  
Streptococcus Pneumoniae ◽  
Pneumococcal Meningitis ◽  
Pneumococcal Infections ◽  
In Vitro Susceptibility ◽  
Focus Of Infection ◽  
Resistance To Penicillin ◽  
Penicillin Treatment ◽  
Susceptibility Tests

For more than 30 years, penicillin has been the agent of choice for pneumococcal infections. During this time the majority of strains of Streptococcus pneumoniae have been highly susceptible to penicillin. However, during the last ten years there have been sporadic reports of pneumococci with increased resistance to penicillin. The case report of an 18-month-old white boy with meningitis due to a strain of S. pneumoniae with increased resistance to penicillin is presented. The MIC of the organism to penicillin was 0.2µg/ml and the MBC 0.39µg/ml. The patient had normal immunity and no demonstrable sequestered focus of infection but failed to respond to appropriate doses of intravenous penicillin. Treatment with chloramphenicol caused a dramatic bacteriologic and clinical response. This experience reemphasizes the existence of pneumococcal strains of intermediate penicillin sensitivity and the importance of in vitro susceptibility tests.

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