TABLE 1

Descriptions of bacterial strains and MICs of colistin and MD3 alone and in combinationa

A. baumannii strainMIC (mg/liter)FICindexDescriptionSource or reference
ColistinMD3COLMD3MD3COL
ATCC 196060.5320.062SynergyA. baumannii type strainATCC
ATCC 19606pmrB64160.54SynergyIsogenic derivative mutant of ATCC 19606; single amino acid substitution (Ala227Val) in PmrB7
ATCC 19606ΔlpxA642161No interactionIsogenic derivative mutant of ATCC 19606; 445-bp deletion at nucleotide 364 within the lpxA gene and frameshift after H1216
ATCC 19606ΔlpxC1282641No interactionIsogenic derivative mutant of ATCC 19606; 84-bp deletion within the lpxC gene6
ATCC 19606ΔlpxD2,05621,0281No interactionIsogenic derivative mutant of ATCC 19606; single-base deletion at nucleotide 364 of the lpxD gene and frameshift after K3176
ABRIM0.5320.064SynergyA. baumannii clinical isolate13
ABRIMpmrB3280.51SynergyIsogenic derivative mutant of ABRIM; single amino acid substitution (Asn353Tyr) in PmrB7
AB2480.25640.031SynergyA. baumannii clinical isolate14
AB249pmrB256320.258SynergyIsogenic clinical isolate derivative of AB248; single amino acid substitution (Pro233Ser) in PmrB14
AB2990.25640.034SynergyA. baumannii clinical isolate14
AB347pmrB64160.254SynergyIsogenic clinical isolate derivative of AB299; single amino acid substitution (Pro170Leu) in PmrB14
  • a COLMD3, colistin MICs in the presence of MD3; MD3COL, MD3 MICs in the presence of colistin; ATCC, American Type Culture Collection.