mcr-1 sharing between co-habiting dogs and humans in the community, Portugal 2018-2020. Animal and human sharing of mcr-1-positive Enterobacterales, Portugal

Colistin is one of the last-resort therapeutic options against multidrug-resistant Gram-negative bacteria. Hence, increase reports of plasmid-mediated colistin resistance poses a major public health issue threat, requiring a careful monitoring. In the preset study, colistin-resistant Escherichia coli recovered from faecal samples of dogs and their household members in Portugal were sequenced, producing whole genome sequences paired-end libraries with 150 bp. All isolates harbored the mcr-1 gene.WGS assemblies displayed an average coverage depth of 155x and L50 =15. Analysis of genetic relatedness suggests the occurrence of transmission in two households.The main risk factor for mcr carriage in animals and humans was having a co-habiting individual from the other specie colonized with colistin resistant E. coli. This is the first detection of mcr-1 in the community set in Portugal and warrants for the spreading of these clinical important genes into the community.