Insertion sequence 1515 in the ply gene of a type 1 clinical isolate of Streptococcus pneumoniae abolishes pneumolysin expression

A serotype 1 Streptococcus pneumoniae strain isolated by blood culture from a woman with pneumonia was found to harbor insertion sequence (IS) 1515 in the pneumolysin gene, abolishing pneumolysin expression. To our knowledge, this is the first report of an IS in the pneumolysin gene of S. pneumoniae.