. 2011 Aug;55(8):3743–3751. doi: 10.1128/AAC.00256-11

Table 3.

Amino acid changes or mutations in the pmrCAB polymyxin B-resistant WT-derived strains (compared to their parental WT strain ATCC 17978) and pmrCAB variants of polymyxin B-resistant clinical isolates (compared to a consensus sequence)^a

Strain	PXB^b MIC (μg/ml)	Amino acid change(s) in^c:
		pmrC (549 aa)		pmrA (224 aa)		pmrB (444 aa)
		aa 1–236	Sulfatase (aa 237–532)	Rec (aa 5–116)	aa 117–131	aa 1–215	HisK (aa 216–276)	aa 277–330	HATPaseC (aa 331–419)
WT	0.5
R9	2						R231L
R3	4							G315D
R5	4			M12I
R6	4						R263P	Q277H
R7	4							G315D
R2	8						T235I
C14	8	T7I, A211V				Δ160
C2	16					D64V, L208F
C8	16					L208F
C11	16		H499R*			Δ32–35			P360Q*
C13	16					P170Q
C12	16						N256I
C87	16	F90L			S119T		P233S		P360Q*
C5	32						R263C		P377L
C4	64						A226V
C15	64					A80V, P170L

Sequences were compared to a consensus sequence made by alignment of the pmrCAB operons from the genome sequences of the following strains: ATCC 17978 (Yale University); AYE (Genoscope, France); ACICU (National Research Centre, Italy); AB0057, AB307-0294, and AB900 (Case Western Reserve University); 1656-2 (Kyungpook National University/GenoTech Corporate, South Korea), and TCDC-AB0715 (Taiwan Center for Disease Control, Taiwan). Accordingly, the identified single nucleotide polymorphisms (SNPs; naturally variant between the sequenced isolates) pmrC(F166L), pmrC(A370S), pmrC(K531T), and pmrB(A444V) occurred in each of the clinical isolates C2, C4, C5, C8, C12, C13, and C15 but not in C11, C14, or C87. In addition, the SNP pmrC(H499R) (marked with an asterisk) was found only in clinical isolate C11. The SNP pmrB(P360Q) (marked with an asterisk) occurred in clinical isolates C11 and C87 but none of the other strains. aa, amino acids.

Polymyxin B (PXB) MICs were assessed by the broth microdilution method according to the CLSI.

The predicted domains according to the NCBI domain predictor (www.ncbi.nlm.nhi.gov/protein) are indicated as follows: sulfatase, sulfatase domain; Rec, signal receiver domain; HisK, histidine kinase (dimerization/phosphoacceptor) domain; and HATPaseC, histidine-kinase-like ATPase. Only domains or regions displaying mutations or variants are shown. The amino acid (aa) positions corresponding to these domains are displayed in brackets.