scholarly journals Serotyping of Streptococcus pneumoniaeby Coagglutination with 12 Pooled Antisera

1999 ◽  
Vol 37 (1) ◽  
pp. 263-265 ◽  
Author(s):  
M. K. Lalitha ◽  
Kurien Thomas ◽  
R. Satish Kumar ◽  
Mark C. Steinhoff
Keyword(s):  
Streptococcus Pneumoniae ◽  
Pneumococcal Vaccine ◽  
Cross Reactivity ◽  
Typing Methods

We report on the performance of a recently introduced commercial chessboard method using 12 antisera, in comparison with that of the 55-antiserum panel used in determining the serogroups and types (SGTs) of Streptococcus pneumoniae, both of which were carried out by a coagglutination technique. Of a total of 150 strains of S. pneumoniae studied, 135 (90%) belonged to the SGTs represented in the 23-valent pneumococcal vaccine; of these, 130 (96.3%) were identified as the same SGTs by both typing methods. The remaining five strains showed cross-reactivity with more than two pools by the chessboard method, but could be assigned to a single SGT by the Quellung test. The 96.3% concordance of the chessboard method suggests it can be adopted for determination of the SGTs of S. pneumoniae in laboratories.

scholarly journals A Common Food Glycan, Pectin, Shares an Antigen with Streptococcus pneumoniae Capsule

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Moon H. Nahm ◽  
Jigui Yu ◽  
Jiri Vlach ◽  
Maor Bar-Peled
Keyword(s):  
Immune Response ◽  
Streptococcus Pneumoniae ◽  
Immune Responses ◽  
Pneumococcal Vaccine ◽  
Cross Reactivity ◽  
Food Plants ◽  
Content Type ◽  
Plant Foods ◽  
Vaccine Responses ◽  
The Impact

ABSTRACT We are exposed daily to many glycans from bacteria and food plants. Bacterial glycans are generally antigenic and elicit antibody responses. It is unclear if food glycans’ sharing of antigens with bacterial glycans influences our immune responses to bacteria. We studied 14 different plant foods for cross-reactivity with monoclonal antibodies (MAbs) against 24 pneumococcal serotypes which commonly cause infections and are included in pneumococcal vaccines. Serotype 15B-specific MAb cross-reacts with fruit peels, and serotype 10A MAb cross-reacts with many natural and processed plant foods. The serotype 10A cross-reactive epitope is 1,6-β-galactosidase [βGal(1-6)], present in the rhamno-galacturonan I (RG-I) domain of pectin. Despite wide consumption of pectin, the immune response to 10A is comparable to the responses to other serotypes. An antipectin antibody can opsonize serotype 10A pneumococci, and the shared βGal(1-6) may be useful as a simple vaccine against 10A. Impact of food glycans should be considered in host-pathogen interactions and future vaccine designs. IMPORTANCE The impact of food consumption on vaccine responses is unknown. Streptococcus pneumoniae (the pneumococcus) is an important human pathogen, and its polysaccharide capsule is used as a vaccine. We show that capsule type 10A in a pneumococcal vaccine shares an antigenic epitope, βGal(1-6), with pectin, which is in many plant foods and is widely consumed. Immune response to 10A is comparable to that seen with other capsule types, and pectin ingestion may have little impact on vaccine responses. However, antibody to pectin can kill serotype 10A pneumococci and this shared epitope may be considered in pneumococcal vaccine designs.

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.

Human Prothrombin Activation: Determination of Plasma and Serum Levels of Prothrombin Fragment 3 by Radioimmunoassay

1979 ◽  
Author(s):  
Daniel Walz ◽  
Thomas Brown
Keyword(s):  
Blood Clotting ◽  
Factor Xa ◽  
Heart Association ◽  
Serum Levels ◽  
Cross Reactivity ◽  
Assay Procedure ◽  
A Chain ◽  
Prothrombin Activation ◽  
Theoretical Amount

Human prothrombin activation is unique in that, in addition to the release of fragment 1.2 (FI.2) from the NH-terminus of prothrombin by factor Xa during the generation of thrombin, an additional 13 residue polypeptide, fragment 3 (F3), is autocatalytically removed from the amino-terminus of the thrombin A chain. We have developed a rapid radioimmunoassay for human F3 which incorporates short incubation times and the use of a preprecipitated second antibody; the assay can be performed in three hours. Specificity studies in buffer systems show prothrombin and prethrombin 1 cross-reacting at a level of 0.001; purified thrombin does not cross-react. In the presence of 5% BSA, prothrombin displays considerably less cross-reactivity. No immunoreactive material to F3 antibodies could be detected in 400 μL of plasma. Serum, obtained from whole blood clotting, contained measurable quantities of F3 (40-100 ng/mL). This amount in serum represents only 5-10% of the theoretical amount available should all of the fragment be hydrolytically cleaved during the conversion of prothrombin to thrombin. This assay procedure is currently being utilized to monitor the activation of purified human prothrombin in the absence and presence of selected plasma inhibitors. (Supported in part by NIH 05384-17 and the Michigan Heart Association).

scholarly journals The pathway through LC-MS method development: in-house or ready-to-use kit-based methods?

2020 ◽  
Vol 58 (6) ◽  
pp. 1002-1009 ◽  
Author(s):  
Caroline Le Goff ◽  
Jordi Farre-Segura ◽  
Violeta Stojkovic ◽  
Patrice Dufour ◽  
Stéphanie Peeters ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Method Development ◽  
Clinical Laboratory ◽  
Cross Reactivity ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

AbstractHistorically, the determination of low concentration analytes was initially made possible by the development of rapid and easy-to-perform immunoassays (IAs). Unfortunately, typical problems inherent to IA technologies rapidly appeared (e.g. elevated cost, cross-reactivity, lot-to-lot variability, etc.). In turn, liquid chromatography tandem mass spectrometry (LC-MS/MS) methods are sensitive and specific enough for such analyses. Therefore, they would seem to be the most promising candidates to replace IAs. There are two main choices when implementing a new LC-MS/MS method in a clinical laboratory: (1) Developing an in-house method or (2) purchasing ready-to-use kits. In this paper, we discuss some of the respective advantages, disadvantages and mandatory requirements of each choice. Additionally, we also share our experiences when developing an in-house method for cortisol determination and the implementation of an “ready-to-use” (RTU) kit for steroids analysis.

scholarly journals Use and efficacy of pneumococcal vaccine in patients with Hodgkin disease

Blood ◽  
1979 ◽  
Vol 54 (5) ◽  
pp. 1171-1175 ◽  
Author(s):  
AM Levine ◽  
GD Overturf ◽  
RF Field ◽  
D Holdorf ◽  
A Paganini-Hill ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antibody Response ◽  
Haemophilus Influenzae ◽  
Pneumococcal Vaccine ◽  
Hodgkin Disease ◽  
Bacterial Sepsis ◽  
Severe Impairment ◽  
Postsplenectomy Sepsis ◽  
Previously Treated ◽  
Normal Controls

Abstract Fulminant bacterial sepsis has been described in patients with Hodgkin disease who have undergone splenectomy for staging purposes. The organisms commonly associated with sepsis in this setting include Streptococcus pneumoniae and Haemophilus influenzae. Polyvalent pneumococcal vaccine (Merck) has recently been licensed and has been suggested for use in patients with Hodgkin disease who are at risk for postsplenectomy sepsis. We administered 14-valent pneumococcal vaccine to 24 patients with Hodgkin disease and 24 normal controls, and measured antibody response to 13 antigens at time of immunization and at 3 wk and 3 mo following immunization. Our results indicate that patients who have been previously treated for Hodgkin disease, with chemotherapy, radiotherapy, or both, have severe impairment of antibody response. Untreated patients, however, respond in a manner similar to normal controls.

RADIOIMMUNOASSAY FOR 2-METHOXYOESTRONE IN HUMAN PLASMA

1979 ◽  
Vol 91 (1) ◽  
pp. 158-166 ◽  
Author(s):  
Günter Emons ◽  
Peter Ball ◽  
Gertrud v. Postel ◽  
Rudolf Knuppen
Keyword(s):  
Human Plasma ◽  
Plasma Concentrations ◽  
Cross Reactivity ◽  
Elderly Men ◽  
Specific Antibodies ◽  
Assay Procedure ◽  
Menopausal Women ◽  
Bovine Serum Albumin Conjugate ◽  
Post Menopausal

ABSTRACT A bovine serum albumin conjugate of 2-methoxyoestrone was used for the preparation of highly specific antibodies in rabbits. Cross-reactivity for catecholoestrogens and monophenolic steroids was below 0.3 %. Only 2-methoxyoestradiol cross-reacted with 44 %. An assay procedure for the determination of unconjugated and conjugated 2-methoxyoestrone in human plasma is described. The following mean plasma concentrations (pg/ml) were found (unconjugated/conjugated): children 61/1130, young men 74/1320, elderly men 109/1260, cycling women 131/1040, post-menopausal women 102/1420, and pregnant women 3980/5850.

scholarly journals Determination of penicillin resistance in Streptococcus pneumoniae isolates from southern Brazil by PCR

2006 ◽  
Vol 10 (2) ◽  
pp. 110-115 ◽  
Author(s):  
Eduardo Walker Zettler ◽  
Rosane Machado Scheibe ◽  
Cícero A.G. Dias ◽  
Patrícia Santafé ◽  
Diógenes Santiago Santos ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Penicillin Resistance ◽  
Southern Brazil
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