 The original strain described by <unk> is believed to be lost , consequently a new type strain ( neotype ) was chosen as a representative : the neotype strain is U5 / <unk> , also known under the deposit names DSM <unk> , ATCC <unk> , and <unk> <unk> , which is pathogenic to chickens and has an O1 : K1 : H7 serotype . However , in most studies , either O157 : H7 , K @-@ 12 MG1655 , or K @-@ 12 W3110 were used as a representative E. coli . The genome of the type strain has only lately been sequenced . Particularly the use of whole genome sequences yields highly supported phylogenies . Based on such data , five subspecies of E. coli were distinguished . 
