Table 1. Characteristics of the mcr-4 positive strains analysed in this study, Italy 2013, Spain and Belgium, 2015 to 2016 (n = 4), and their transformants and conjugants.
Strain | Country | MLST | Plasmid content | Plasmid-mediated colistin resistance | Additional resistance genes | Colistin MIC mg/L |
---|---|---|---|---|---|---|
R3445
Salmonella enterica |
Italy | 34 | ColE10, ColRNAI_34, ColRNAI_36, ColRNAI_38, ColRNAI_46 |
mcr-4 | bla TEM-1B, strA, strB, sul2, tet(B) | 8 |
3445T (transformant in DH5-α) | ColE10 | mcr-4 | 2 | |||
DH5-α | 0.25 | |||||
R4287
Escherichia coli |
Spain | 10 (CC10) | I1, I2, FII, FIB, FIC, HI2, Col156, ColRNAI_34, ColE10 | mcr-4 | bla TEM-1B, aph(4)-1a, aph(3’)-1c, aac(3)-IVa, aac(3)-IIa, strA, aadA1, floR, catA1, sul2, sul1, tet(B), dfrA1, mph(A), erm(B), mphB | 8 |
4287C (conjugant in CSH26 RifR) | ColE10, I2 | mcr-4 | 4 | |||
CSH26 RifR | 0.25 | |||||
R4280
E. coli |
Belgium | 10 (CC10) |
I1, FII, FIB, FIC, HI2, Col(MG828), ColRNAI_34, ColE10 | mcr-4 | bla TEM-1B, aph4–1a, aac(3)-IVa, strB, aadA1, floR, catA1, sul1, tet(B), dfrA1, mph(B) | 8 |
R4278
E. coli |
Belgium | 7029 | I1, X1, FII(pCoo), ColE10 | mcr-4 | bla TEM-1B, strA, strB, aadA1, sul2, sul1, tet(A), dfrA1 | 16 |
MIC: minimum inhibitory concentration; MLST: multilocus sequence typing.