Characteristics of Streptococcus pseudopneumoniae isolated from purulent sputum samples.

Streptococcus pseudopneumoniae is a recently described streptococcus that is phenotypically and genetically distinct from Streptococcus pneumoniae and other viridans streptococci. Key characteristics of S. pseudopneumoniae are the absence of a pneumococcal capsule, insolubility in bile, resistance or indeterminate susceptibility to optochin when incubated in 5% CO2 but susceptibility to optochin when incubated in ambient air, and a positive reaction with the AccuProbe DNA probe hybridization test.