Short-term evolution of Shiga toxin-producing Escherichia coli O157:H7 between two food-borne outbreaks.

ABSTRACT: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is a public health threat and outbreaks occur worldwide. Here, we investigate genomic differences between related STEC O157:H7 that caused two outbreaks, eight weeks apart, at the same restaurant. Short-read genome sequencing divided the outbreak strains into two sub-clusters separated by only three single-nucleotide polymorphisms in the core genome while traditional typing identified them as separate phage types, PT8 and PT54. Isolates did not cluster with local strains but with those associated with foreign travel to the Middle East/North Africa. Combined long-read sequencing approaches and optical mapping revealed that the two outbreak strains had undergone significant microevolution in the accessory genome with prophage gain,

SUBMITTER: Cowley LA 

PROVIDER: S-EPMC5320650 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature