The joint lesions which accompany #acute rheumatism# or "rheumatic fever" are believed to be due to a diplococcus.
"Manual of Surgery" by Alexis Thomson and Alexander Miles
For instance, not a few healthy noses and throats contain the bacillus of diphtheria and the diplococcus of pneumonia.
"Preventable Diseases" by Woods Hutchinson
Take an 18- to 24-hour culture of the required bacterium (e. g., Diplococcus pneumoniae) grown upon sloped blood agar at 37 deg.
"The Elements of Bacteriological Technique" by John William Henry Eyre
The diplococcus merely produces acidification and coagulation of the milk.
"The Bacillus of Long Life" by Loudon Douglas