Table 1.

Amino acid changes in PmrA/PmrB, PhoP/PhoQ^a, and MgrB in colistin-resistant E. coli strains^a

Strain	Substitution(s)b in
	MgrB	PhoQ	PhoP	PmrA	PmrB
TSAREC02	Δ43-47c				G206R, Y222H
TSAREC03			Δ84-224d		M1I, L14P, P178S, T235N

^aUnique amino acid substitutions found only in colistin-resistant E. coli strains TSAREC02 and TSAREC03 after alignment with clinical colistin-susceptible E. coli isolates (ECS01 to ECS08) and MG1655(8).

^bThe one-letter code for amino acid designation was used

^cDeleted amino acid sequence: QFIPW

^dDeleted amino acid sequence: WQDKVEVLSAGADDYVTKPFHIEEVMARMQALMRRNSGLASQVISLPPFQVDLSRRELSINDEVIKLTAFEYTIMETLIRNNGKVVSKDSLMLQLYPDAELRESHTIDVLMGRLRKKIQAQYPQEVITTVRGQGYLFELR