How does pneumolysin affect the body?
Released pneumolysin will aid the bacteria during colonization by facilitating adherence to the host, during invasion by damaging host cells, and during infection by interfering with the host immune response. The presence of pneumolysin in sputum, urine, CSF and blood can be indicative of an S. pneumoniae infection.
Is pneumolysin pathogenic?
Streptococcus pneumoniae is an opportunistic pathogen responsible for widespread illness and is a major global health issue for children, the elderly, and the immunocompromised population.
What produces pneumolysin?
INTRODUCTION. Pneumolysin (PLY) is a hemolytic protein toxin produced by Streptococcus pneumoniae (the pneumococcus). The pneumococcus causes several important diseases of man including pneumonia, bacteraemia, meningitis, and otitis media.
What are two major virulence factors of strep pneumoniae?
Major pneumococcal-protein virulence factors, such as pneumolysin, neuraminidases, the cell-surface proteins PspA, PspC and LytA and the metal-ion-binding proteins PsaA, PiaA and PiuA, have specific roles in respiratory colonization and disease.
Is pneumolysin an exotoxin?
A major exotoxin of Streptococcus pneumoniae is pneumolysin (24). Pneumolysin is a multifunctional bacterial cytoplasmic protein of 53 kDa with a wide range of cytotoxic and proinflammatory properties, and it is an important determinant of pneumococcal virulence (28).
Where is pneumolysin found?
Pneumolysin is present within the bacterial cytoplasm and because it does not have a N-terminal secretion signal sequence, lysis of the bacteria is essential for its release [9].
Is pneumolysin a hemolysin?
Pneumolysin was found to be produced by 112 of 113 clinical isolates of Streptococcus pneumoniae and to be an intracellular hemolysin.
Is pneumolysin an endotoxin?
What is the function of pneumolysin?
Pneumolysin is a cholesterol-dependent cytolysin (CDC) toxin that forms lytic pores in host membranes and mediates pneumococcal disease pathogenesis by modulating inflammatory responses.
What is the virulence factor of Streptococcus pneumoniae?
Polysaccharide capsule: S. pneumoniae’s extracellular polysaccharide capsule, the most important virulence factor (55), helps to initiate infection by allowing the bacterium to adhere to host cells and cause inflammation, while also providing protection from the host’s immune system (54, 55).
Is pneumolysin a neurotoxin?
In conclusion, pneumolysin is a major neurotoxin of S. pneumoniae. Characteristic features of apoptosis induced by live pneumococci, especially the absence of caspase activation, are mediated by pneumolysin.
How does pneumolysin cause damage to the host?
Pneumolysin present in the systemic circulation has also been shown to cause myocardial injury during pneumococcal infection17. Moreover, pneumolysin triggers activation of pro-inflammatory immune cells, leading to release of reactive oxygen and nitrogen species that damage host tissues18,19.
Is pneumolysin a virulence factor from Streptococcus pneumoniae?
“The molecular mechanism of pneumolysin, a virulence factor from Streptococcus pneumoniae”. Journal of Molecular Biology. 284 (2): 449–61. doi: 10.1006/jmbi.1998.2167.
What is the structure of pneumolysin?
Pneumolysin is a putative virulence factor of the Gram-positive bacteria Streptococcus pneumoniae. It is a pore-forming toxin of 53 kDa composed of 471 amino acids.
Why is it important to study pneumococcal virulence factors?
By increasing our knowledge about pneumococcal virulence factors, we will aid the development of a better vaccine or drug and contribute to the increase in the survival rate of infected patients. ACKNOWLEDGMENTS I acknowledge grant support from the National Institutes of Health (AI 44079) and from Aventis Pasteur.
What is the role of pneumolysin in colonization?
Released pneumolysin will aid the bacteria during colonization by facilitating adherence to the host, during invasion by damaging host cells, and during infection by interfering with the host immune response. The presence of pneumolysin in sputum, urine, CSF and blood can be indicative of an S. pneumoniae infection .