scholarly journals Detection of Intrastrain Antigenic Variation of Bacteroides fragilis Surface Polysaccharides by Monoclonal Antibody Labelling

1999 ◽  
Vol 67 (9) ◽  
pp. 4346-4351 ◽  
Author(s):  
Sheila Patrick ◽  
Deirdre Gilpin ◽  
Leanne Stevenson
Keyword(s):  
Monoclonal Antibody ◽  
Anaerobic Bacterium ◽  
Antigenic Variation ◽  
Bacteroides Fragilis ◽  
Virulence Determinants ◽  
Immunomagnetic Beads ◽  
Individual Strain ◽  
Surface Polysaccharides ◽  
Immunodiagnostic Tests ◽  
Antibody Labelling

ABSTRACT Bacteroides fragilis is a constituent of the normal resident microbiota of the human intestine and is the gram-negative obligately anaerobic bacterium most frequently isolated from clinical infection. Surface polysaccharides are implicated as potential virulence determinants. We present evidence of within strain immunochemical variation of surface polysaccharides in populations that are noncapsulate by light microscopy as determined by monoclonal antibody labelling. Expression of individual epitopes can be enriched from a population of an individual strain by use of immunomagnetic beads. Also, individual colonies in which either >94% or <7% of the bacteria carry an individual epitope retain this level of expression when subcultured into broth. In broth cultures where >94% of the bacteria carry a given epitope, there is no enrichment for other epitopes recognized by different polysaccharide-specific monoclonal antibodies. This intrastrain variation has important implications for the development of potential vaccines or immunodiagnostic tests.

scholarly journals A broadly neutralizing monoclonal antibody induces broad protection against heterogeneous PRRSV strains in piglets

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Zhigang Zhang ◽  
Tianshu Zhai ◽  
Mingshuo Li ◽  
Kun Zhang ◽  
Jingrui Li ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Neutralizing Antibodies ◽  
Antigenic Variation ◽  
Profile Analysis ◽  
Expression Profiles ◽  
Enrichment Analysis ◽  
Antibody Isotype ◽  
Hilar Lymph Node

AbstractNeutralizing antibodies (NAbs) have attracted attention as tools for achieving PRRSV control and prevention, but viral antigenic variation undermines the abilities of NAbs elicited by attenuated PRRSV vaccines to confer full protection against heterogeneous PRRSV field isolates. As demonstrated in this study, the monoclonal antibody (mAb) mAb-PN9cx3 exhibited broad-spectrum recognition and neutralizing activities against PRRSV-1 and PRRSV-2 strains in vitro. Furthermore, in vivo experiments revealed that the administration of two 10-mg doses of mAb-PN9cx3 before and after the inoculation of piglets with heterologous PRRSV isolates (HP-PRRSV-JXA1 or PRRSV NADC30-like strain HNhx) resulted in significant reduction of the PRRSV-induced pulmonary pathological changes and virus loads in porcine alveolar macrophages (PAMs) compared with the results obtained with mAb-treated isotype controls. Moreover, minimal hilar lymph node PRRSV antigen levels were observed in mAb-PN9cx3-treated piglets. A transcriptome profile analysis of PAMs extracted from lung tissues of piglets belonging to different groups (except for antibody-isotype controls) indicated that mAb-PN9cx3 treatment reversed the PRRSV infection-induced alterations in expression profiles. A gene ontology (GO) enrichment analysis of these genes traced their functions to pathways that included the immune response, inflammatory response, and response to steroid hormone, and their functions in oogenesis and positive regulation of angiogenesis have been implicated in PRRSV pathogenesis. Overall, NADC30-like HNhx infection affected more gene pathways than HP-PRRSV infection. In conclusion, our research describes a novel immunologic approach involving the use of mAbs that confer cross-protection against serious illness resulting from infection with heterogeneous PRRSV-2 isolates, which is a feat that has not yet been achieved through vaccination. Ultimately, mAb-PN9cx3 will be a powerful addition to our current arsenal for achieving PRRSV prevention and eradication.

scholarly journals Multiple inverted DNA repeats of Bacteroides fragilis that control polysaccharide antigenic variation are similar to the hin region inverted repeats of Salmonella typhimurium

Microbiology ◽  
2003 ◽  
Vol 149 (4) ◽  
pp. 915-924 ◽  
Author(s):  
Sheila Patrick ◽  
Julian Parkhill ◽  
Lisa J. McCoy ◽  
Nicola Lennard ◽  
Michael J. Larkin ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Antigenic Variation ◽  
Bacteroides Fragilis ◽  
Inverted Repeats ◽  
Dna Repeats

scholarly journals Localization of the Major Allergen Bet V 1 inBetulaPollen Using Monoclonal Antibody Labelling

Grana ◽  
1996 ◽  
Vol 35 (6) ◽  
pp. 369-374 ◽  
Author(s):  
Gamal El-Ghazaly ◽  
Sumio Nakamura ◽  
Yuichi Takahashi ◽  
Mauro Cresti ◽  
Bjöorn Walles ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Major Allergen ◽  
Bet V 1 ◽  
Antibody Labelling

Actinobacillus pleuropneumoniaesurface polysaccharides: their role in diagnosis and immunogenicity

2000 ◽  
Vol 1 (2) ◽  
pp. 73-93 ◽  
Author(s):  
J. Daniel Dubreuil ◽  
Mario Jacques ◽  
Khyali R. Mittal ◽  
Marcelo Gottschalk
Keyword(s):  
Vaccine Development ◽  
Current Knowledge ◽  
Diagnostic Tools ◽  
Virulence Determinants ◽  
Animal Protection ◽  
Rtx Toxins ◽  
Crucial Information ◽  
Surface Polysaccharides ◽  
Review Current

AbstractActinobacillus pleuropneumoniaeis an important pig pathogen that is responsible for swine pleuropneumonia, a highly contagious respiratory infection. Knowledge of the importance, composition and structural determination of the major antigens involved in virulence provides crucial information that could lead to the development of a rationale for the production of specific serodiagnostic tools as well as vaccine development. Thus, efforts have been devoted to study mainlyA. pleuropneumoniaevirulence determinants with special emphasis on the Apx toxins (forA. pleuropneumoniaeRTX toxins). In comparison, little attention has been given to the surface polysaccharides, which include capsular polysaccharides (CPS) and cell-wall lipopolysaccharides (LPS). Here, we review current knowledge on CPS and LPS ofA. pleuropneumoniaeused as diagnostic tools to monitor the infection and as immunogens for inclusion in vaccine preparations for animal protection.

Current Methods for Molecular Epidemiology Studies of Implant Infections

2009 ◽  
Vol 32 (9) ◽  
pp. 642-654 ◽  
Author(s):  
Davide Campoccia ◽  
Lucio Montanaro ◽  
Carla Renata Arciola
Keyword(s):  
Molecular Epidemiology ◽  
Virulence Determinants ◽  
Opportunistic Pathogens ◽  
Bacterial Strains ◽  
Individual Strain ◽  
Clonal Nature ◽  
The Many ◽  
Epidemiology Studies ◽  
Specific Virulence ◽  
Critical Aspects

Over the last few decades, the number of surgical procedures involving prosthetic materials has greatly multiplied, along with the rising medical and economic impact of implant-associated infections. The need to appropriately counteract and deal with this phenomenon has led to growing efforts to elucidate the etiology, pathogenesis and epidemiology of these types of infections, characterized by opportunistic pathogens. Molecular epidemiology studies have progressively emerged as a leading multitask tool to identify and fingerprint bacterial strains, unveil the complex clonal nature of important pathogens, detect outbreak events, track the origin of the infections, assess the clinical significance of individual strain types, survey their distribution, recognize associations of strain types with specific virulence determinants and/or pathological conditions, assess the role played by the specific components of the virulon, and reveal the phylogeny and the mechanisms through which new strain types have emerged. Despite the many advances that have been made thanks to these flourishing new approaches to molecular epidemiology, a number of critical aspects remain challenging. In this paper, we briefly discuss the current limitations and possible developments of molecular epidemiology methods in the investigation and surveillance of implant infections.

Crystal Structure of a Transcarbamylase-like Protein from the Anaerobic Bacterium Bacteroides fragilis at 2.0Å Resolution

2002 ◽  
Vol 320 (4) ◽  
pp. 899-908 ◽  
Author(s):  
Dashuang Shi ◽  
Rene Gallegos ◽  
Joseph DePonte ◽  
Hiroki Morizono ◽  
Xiaolin Yu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Anaerobic Bacterium ◽  
Bacteroides Fragilis
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