Summary

Verocytotoxin-producing E.coli (VTEC/STEC) confirmed by ERL in 2017. VTEC/STEC confirmations continue to increase as another laboratory commenced culture independent testing for this organism at the beginning of 2017. Whole genome sequencing (WGS) was used over some of the 2017 year allowing typing of isolates that were not fully identifiable by phenotypic methods due to being rough; non- motile; or, not reacting in the method. WGS has allowed better recognition of our 10 most common O types: O157, O26, O128, O146, O38, O123/186, O176, O84, O91, O107/117. Note: the USA "Top 7" serotypes only include O157 and O26 from NZ's top 10. However, some of our common types are being regularly seen elsewhere in the world. We still have a significant number of samples from which we have been unable to isolate the organism; and, comprehensive typing is not currently possible without a pure culture isolate. Work is ongoing to improve our isolation ability and the upcoming introduction of routine WGS will allow much better understanding of this organism.