E. coli O157 with confirmation of Shiga toxin when H antigen is unknown, or is not H7
e. coli o157 with confirmation of shiga toxin when h antigen is unknown, or is not h7
E. coli O157 with confirmation of Shiga toxin when H antigen is unknown, or is not H7
e. coli o157 with confirmation of shiga toxin when h antigen is unknown, or is not h7