Multiple resistance factors collectively promote inoculum-dependent dynamic survival during antimicrobial peptide exposure in Enterobacter cloacae
Fig 3
PhoPQ partially contributes to cecB resistance.
Overnight cultures were diluted (A) 10-fold or (B) 100-fold into fresh LB containing 20 μg/mL cecB, and cells were grown at 37°C for 24 hours. For the complement strain, expression of phoPQ from pMMB was induced with 200 μM IPTG. OD600 measurements were taken every 5 minutes. Error bars represent standard deviation (n = 3). (C) Mid-exponential phase cells were placed on 0.8% agarose pads containing the indicated amounts of cecropin and incubated at 37°C. Representative, cropped time frames are shown. Red arrow indicates phase-light cell, white arrow indicates a cell that stays intact.