Novel plasmid-mediated colistin resistance mcr-4 gene in Salmonella and Escherichia coli, Italy 2013, Spain and Belgium, 2015 to 2016 Carattoli, Alessandra and Villa, Laura and Feudi, Claudia and Curcio, Ludovica and Orsini, Serenella and Luppi, Andrea and Pezzotti, Giovanni and Magistrali, Chiara Francesca, Eurosurveillance, 22, 30589 (2017), https://doi.org/10.2807/1560-7917.ES.2017.22.31.30589