Pneumolysin is a

virulence factor Virulence factors (preferably known as pathogenicity factors or effectors in plant science) are cellular structures, molecules and regulatory systems that enable microbial pathogens (bacteria, viruses, fungi, and protozoa) to achieve the following ...

of the

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

bacteria ''

Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They are ...

''. It is a

pore-forming toxin Pore-forming proteins (PFTs, also known as pore-forming toxins) are usually produced by bacteria, and include a number of protein exotoxins but may also be produced by other organisms such as apple snails that produce perivitellin-2 or earthwo ...

of 53 kDa composed of 471

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

. It has a range of

biological activity In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...

, including the ability to lyse and interfere with the function of cells and soluble molecules of the immune system. 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 Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra. Cel ...

, CSF and

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

can be indicative of an ''S. pneumoniae'' infection.

References

External links

World Pneumonia Day
{{pore-forming toxins Bacterial toxins