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  • bacteria
  • Previous studies have shown that while neutrophils, a major bacterium-induced leukocyte, aid in S. pneumoniae elimination, they also contribute to pathology and may mediate the lung-to-blood passage of the bacteria. (asm.org)
  • Many bacterial infections involve biofilms which protect bacteria from host defenses and antibiotics. (asm.org)
  • Probably the most important virulence factor for S. pneumoniae is the extracellular capsule, a layer consisting of chains of monosaccharides that surrounds the bacteria. (asm.org)
  • After infection by caudal vein, we saw focal clogging of the pneumococci in the blood vessels and migration of bacteria through the blood-brain barrier into the subarachnoid space and brain tissue. (biomedcentral.com)
  • serotype
  • Mouse antibodies to recombinant PiuA and PiaA derived from a capsular serotype 2 S. pneumoniae strain react with identical proteins from nine other capsular serotypes ( 8 ), and human sera recovered from patients with recent episodes of S. pneumoniae septicemia due to different capsular serotypes contain anti-PiuA and anti-PiaA which cross-react with recombinant PiuA and PiaA from a single capsular serotype ( 27 ). (asm.org)
  • Streptococcus pneumoniae has multiple protein antigens on the surface in addition to the serotype specific polysaccharide capsule antigen. (synbiosis.com)
  • PnuBioVax (PBV) is being developed as a multi-antigen, serotype-independent prophylactic vaccine against S. pneumoniae disease. (synbiosis.com)
  • To gain insight into the genetics of biofilm formation by S. pneumoniae , we conducted an in vitro screen for biofilm-altered mutants with the serotype 4 clinical isolate TIGR4. (asm.org)
  • Using unencapsulated serotype 2 and 4 S. pneumoniae mutants, we have confirmed that the capsule has several effects on complement activity. (asm.org)
  • vaccine
  • Routine use of the 7-valent pneumococcal conjugate vaccine (PCV7), available since 2000, has resulted in a dramatic reduction in the incidence of invasive pneumococcal disease (IPD) attributable to serotypes of Streptococcus pneumoniae contained in the vaccine. (aappublications.org)
  • The currently available S. pneumoniae vaccines are based on capsular polysaccharide antigens, but as S. pneumoniae is capable of synthesizing at least 90 antigenically different capsular polysaccharides, a polyvalent vaccine containing many capsular antigens is needed for protection against the common serotypes. (asm.org)
  • Because of these drawbacks with capsular antigen vaccines, there has been much interest in developing a protein-based S. pneumoniae vaccine, using surface-expressed proteins which are well conserved across all serotypes ( 1 , 8 , 21 , 22 , 25 , 28 ). (asm.org)
  • Furthermore, the capsule is the target for existing S. pneumoniae vaccines and widespread vaccination has led to the evolution of vaccine escape mutants expressing nonvaccine capsular serotypes, increasing the importance of a better understanding of how the capsule can affect virulence. (asm.org)
  • pathogens
  • Current in vivo models of infection with these pathogens are acute and do not mimic the low-level-persistent bacterial presence seen in COPD sufferers in the stable state ( 10 , 11 , 12 ). (asm.org)
  • Among pathogens of the respiratory system, the ability to form biofilms seems critical for Pseudomonas aeruginosa and Staphylococcus aureus to cause chronic infections ( 32 , 79 , 91 ). (asm.org)
  • Inflammation
  • Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. (frontiersin.org)
  • immunoglobulin
  • There was increased binding of the classical pathway mediators immunoglobulin G (IgG) and C-reactive protein (CRP) to unencapsulated S. pneumoniae , indicating that the capsule could inhibit classical pathway complement activity by masking antibody recognition of subcapsular antigens, as well as by inhibiting CRP binding. (asm.org)
  • vaccination
  • Active or passive vaccination with recombinant PiuA and PiaA protects mice against invasive S. pneumoniae disease. (asm.org)
  • Hence, vaccination with PiaA and PiuA protects against S. pneumoniae infection by inducing antibodies that promote bacterial opsonophagocytosis rather than inhibiting iron transport. (asm.org)
  • Both PiuA and PiaA are likely to be expressed on the bacterial cell surface ( 24 , 26 ), and active or passive vaccination of mice with recombinant PiuA and PiaA protects against invasive S. pneumoniae disease, especially when mice are vaccinated with both antigens ( 8 ). (asm.org)
  • These data suggest that PBV vaccination generates sera that has multiple mechanisms of action that may provide effective protection against pneumococcal infection and give broader strain coverage than the current polysaccharide based vaccines. (synbiosis.com)
  • virulence
  • PiaA and PiuA are the lipoprotein components of the Pia and Piu Streptococcus pneumoniae iron uptake ABC transporters and are required for full virulence in mouse models of infection. (asm.org)
  • PiaA and PiuA are recently identified lipoprotein components of two separate S. pneumoniae iron uptake ABC transporters that are required for full virulence in mouse models of infection ( 4 ). (asm.org)
  • The Streptococcus pneumoniae capsule is vital for virulence and may inhibit complement activity and phagocytosis. (asm.org)
  • Gene
  • By using a transcriptomic approach, we have elucidated the effect of Ni 2+ on the global gene expression of S. pneumoniae D39 by identifying several differentially expressed genes/operons in the presence of a high extracellular concentration of Ni 2+ . (frontiersin.org)
  • The role of manganese (Mn 2+ ), zinc (Zn 2+ ), copper (Cu 2+ ), iron (Fe 2+ ), cobalt (Co 2+ ), and cadmium (Cd 2+ ) on the gene regulation of S. pneumoniae have already been established and several metal-specific acquisition- and efflux-systems have been characterized. (frontiersin.org)
  • Clinical relevance of TLR2, TLR4, CD14 and FcgammaRIIA gene polymorphism in Streptococcus pneumoniae infection. (jpccr.eu)
  • Here we report that the IgA1 protease gene, iga, of Streptococcus pneumoniae is homologous to that of Streptococcus sanguis. (asm.org)
  • By using the S. sanguis iga gene as hybridization probe, the corresponding gene from a clinical isolate of S. pneumoniae was isolated in an Escherichia coli lambda phage library. (asm.org)
  • The complete sequence of the S. pneumoniae iga gene was determined. (asm.org)
  • Southern blot analyses suggested that the S. pneumoniae iga gene is highly heterogenous within the species. (asm.org)
  • neutrophil
  • A decade of studies has provided researchers with comprehensive knowledge on most of the steps involved in neutrophil recruitment to the site of infection. (jimmunol.org)
  • However, anti-PiaA and anti-PiuA did increase complement-independent and -dependent opsonophagocytosis of different serotypes of S. pneumoniae by the human neutrophil cell line HL60. (asm.org)
  • Reduction of this neutrophil influx has been shown to improve survivability during infection. (asm.org)
  • In this study, we use in vitro biotinylation and neutrophil transmigration and in vivo murine infection to identify a system in which two epithelium-localized ATP-binding cassette transporters, MRP1 and MRP2, have inverse activities dictating neutrophil transmigration into the lumen of infected mouse lungs. (asm.org)
  • migration
  • Thus, taken together, our data suggest that galectin-3 plays a role as a soluble adhesion molecule in the recruitment of neutrophils to lungs infected by S. pneumoniae , which induces β 2 -integrin-independent migration. (jimmunol.org)
  • Infection with pneumolysin-deficient S. pneumoniae in the hindbrain ventricle showed attenuated growth and migration through the brain as compared to the wild-type strain. (biomedcentral.com)
  • isolate
  • The case report describes S. pneumoniae isolate from the urine of 63-year-old woman with clinical and bacteriological symptoms of UTI, isolated independently in two bacteriological urine analyses. (jpccr.eu)
  • vaccines
  • Conjugated vaccines composed of 7 to 11 selected polysaccharides bound to nonpneumococcal protein carriers have been developed and protect children aged less than 2 years from invasive S. pneumoniae infections ( 3 , 14 ). (asm.org)
  • lungs
  • We have previously shown that galectin-3, a soluble mammalian lectin, can be found in lungs infected by S. pneumoniae , but not by E. coli , and can mediate the adhesion of neutrophils on the endothelial cell layer, implying its role in the recruitment of neutrophils to lungs infected with S. pneumoniae . (jimmunol.org)
  • Indeed, in the absence of galectin-3, lower numbers of leukocytes, mainly neutrophils, were recruited to the infected lungs during infection by S. pneumoniae . (jimmunol.org)
  • IgA1
  • It is postulated that both carbohydrate variation between the IgA1 substrates studied and the ability of S. pneumoniae glycosidases to cleave carbohydrates from glycoprotein offer an explanation for the different fragment sizes observed. (asm.org)
  • protein
  • One well-characterized family of surface proteins, found in both streptococci and staphylococci, employs an LPXTGE motif that serves both as a cleavage site and an anchor for covalent attachment of a secreted protein to the cell wall ( 22 ). (asm.org)
  • Our study revealed that apoptosis-associated specklike protein containing a caspase recruitment domain (ASC), an adaptor protein for inflammasome receptors such as nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) and absent in melanoma 2 (AIM2), is essentially required for the induction of caspase-1 activation by S. pneumoniae . (jimmunol.org)