Emergence of Escherichia coli ST131 sub-clone H30 producing VIM-1 and KPC-3 carbapenemases, Italy.

clone over years, even though repeated introductions of mecC-positive isolates cannot be excluded. Finally, the description of divergent but closely related spa types and PFGE patterns among the mecC-positive isolates potentially reflects local microevolution or the circulation of different subclones. No epidemiological link was evidenced between the three colonized farms, neither at the animal level (exchanges and contiguous fields) nor at the farmer level (shared employees and relatives). Also, no human mecC-positive MRSA was reported in the nearby hospitals (F. Laurent, personal observation). Since the dynamics of expansion of this clone is not known, further studies are required to explore the capacity of mecC-positive isolates to persist and propagate on and between cattle farms and eventually disseminate from animals to humans.