Isolation and Characterization of a Second Isolate of Streptococcus iniae

A second strain of Streptococcus iniae has been recovered from an Amazon freshwater dolphin (Inia geoffrensis). This isolate differs from the first-described isolate in its ability to produce acid from lactose but not salicin and its inability to hydrolyze esculin. The two isolates share a common cell wall antigen that appears to represent the C polysaccharide grouping antigen of this species. In addition, there are strain-specific antigens associated with each isolate. The second strain has been designated strain BU (= ATCC 29177).