Table 3.

Composition of lipid A in colistin-resistant and -susceptible A. baumannii clinical pair Ab15/133 and Ab15/32 and in ATCC 19606 and ABRIM and their derivatives

Peak (m/z)Chemical inferenceChemical compositionaPresence/absence of chemical interference in:
Ab15/133 (colistin susceptible)Ab15/132 (colistin resistant)ABRIM ColS (colistin susceptible)ABRIM ColR (colistin resistant)ATCC 19606 ColS (colistin susceptible)ATCC 19606 ColR (colistin resistant)ATCC 19606 ColS ΔpmrB (colistin susceptible)ATCC 19606 ColR ΔpmrB (colistin susceptible)
1,404Tetra-acylated lipid A2 glucose residues++++++++
2 phosphates
3 acyl groups, 12:0(3-OH)
1 acyl group, 14:0(3-OH)
1,530Penta-acylated lipid A2 glucose residues++
2 phosphates
2 acyl groups, 12:0(3-OH)
2 acyl groups, 14:0(3-OH)
1 acyl group, 12:0
1,728Hexa-acylated lipid A2 glucose residues+++++
2 phosphates
3 acyl groups, 12:0(3-OH)
2 acyl groups, 14:0(3-OH)
1 acyl group, 12:0
1,910Hepta-acylated lipid A2 glucose residues++++++++
2 phosphates
3 acyl groups, 12:0(3-OH)
2 acyl groups, 14:0(3-OH)
2 acyl groups, 12:0
2,034Phosphoethanolamine-modified2 glucose residues+++
    hepta-acylated lipid A2 phosphates
3 acyl groups, 12:0(3-OH)
2 acyl groups, 14:0(3-OH)
2 acyl group, 12:0
1 phosphoethanolamine