Table 2.

MICs of the parent P. mirabilis strain and the four AP-sensitive mutants

Antimicrobial compoundMIC (μg/ml)a for strain:
JSG785JSG945JSG946JSG947JSG948
PM>6,4002051,6003,200
IB-367b 1006.250.78100100
IB-255c >420>420>420>420>420
IB-256d 640806.7640640
IB-332e >440440110>440>440
IB-352f >60015037.5600600
IB-355g 6003818.8150300
Novobiocin>1,00025063250125
Tetracycline3115633131
Vancomycin>1,000250250500500
Gentamicin10.50.50.750.75
Tobramycin10.50.50.50.75
Nisin>2,000>2,000>2,000>2,000>2,000
  • a MIC is defined as the lowest concentration of antimicrobial compound that completely inhibited visually observable bacterial growth.

  • b IB-367 is a protegrin analog (NH2-RGGLCYCRGRFCVCVGR-CONH2).

  • c IB-255 is a synthetic analog of polyphemusin (NH2-RRWCYRKCYKGYCYRKCR-CONH2).

  • d IB-256 is polyphemusin II (NH2-RRWCRFVCYKGFCYRKCR-CONH2).

  • e IB-332 is a tachytegrin (NH2-RGGCRLYCRRRFCVVGCR-CONH2).

  • f IB-352 is a tachytegrin (NH2-RGRVCLRYCRGRFCVRLCFR-CONH2).

  • g IB-355 is a tachytegrin (NH2-RGGRVCLRYCRGKFCVRLCLR-CONH2).