Optochin resistance in Streptococcus pneumoniae induced by frozen storage in glycerol.

Susceptibility to optochin is frequently the only test used to differentiate Streptococcus pneumoniae from other alpha-hemolytic streptococci isolated from clinical specimens. The current study shows that storage of S. pneumoniae isolates in tryptic soy broth containing 15% glycerol at -70 degrees C can lead to optochin resistance.

Differential activation of inflammatory pathways in A549 type II pneumocytes by Streptococcus pneumoniae strains with different adherence properties.

Background: Adherence of Streptococcus pneumoniae bacteria to lung cells is a first step in the progression from asymptomatic carriage to pneumonia. Adherence abilities vary widely among S. pneumoniae patient isolates.