This is a gram positive, spore-forming anaerobe.
This is a gram-positive, alpha-hemolytic, bile soluble diplococcus. Pneumococcus is an anaerobe but is aerotolerant.
New research (first author Saifullah Nasir) on Streptococcus pneumonia causing lung necrosis:
http://idsa.confex.com/idsa/2010/webprogram/Paper5097.html
The prevalence of lung necrosis from S. pneumo in adults may be higher than perviously estimated.