Diplococcus
Encyclopedia
A diplococcus is a round bacterium
(a coccus
) that typically occurs in the form of two joined cells. Examples are Streptococcus pneumoniae
, Moraxella catarrhalis
, Neisseria gonorrhoeae
and Neisseria meningitidis
. Of these, all are Gram-negative
except for Streptococcus pneumoniae.
Its name comes from diplo, meaning double, and coccus, meaning berry.
In former times, a bacterial genus
Diplococcus was recognized, but it is not used anymore.
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
(a coccus
Coccus
Coccus can be used to describe any bacterium that has a spherical shape. It is one of the three distinct types of bacteria shapes, the other two being bacillus and spirillum cells...
) that typically occurs in the form of two joined cells. Examples are Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...
, Moraxella catarrhalis
Moraxella catarrhalis
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system and joints of humans.-History:...
, Neisseria gonorrhoeae
Neisseria gonorrhoeae
Neisseria gonorrhoeae, also known as gonococci , or gonococcus , is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.N...
and Neisseria meningitidis
Neisseria meningitidis
Neisseria meningitidis, often referred to as meningococcus, is a bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life threatening sepsis. N. meningitidis is a major cause of morbidity and mortality during childhood in industrialized countries...
. Of these, all are Gram-negative
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
except for Streptococcus pneumoniae.
Its name comes from diplo, meaning double, and coccus, meaning berry.
In former times, a bacterial genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Diplococcus was recognized, but it is not used anymore.