Table 1.

Summary of AFM Adhesion Force, F_A, and PD, Measurements for A. baumannii Bound and Loose EPS

	bound EPS			loose EPS
conditiona	FA (nN)	PD (nm)	no. of events	FA (nN)	PD (nm)	no. of events
untreated	0.144 ± 0.002	106.4 ± 4.7	828	0.177 ± 0.002	218.0 ± 9.2	1677
			NaCl
1 M	0.172 ± 0.001	26.1 ± 5.9	1569	0.129 ± 0.001	15.9 ± 0.2	368
2 M	0.378 ± 0.007	28.3 ± 3.4	1149	0.135 ± 0.001	48.6 ± 0.5	830
			Maltodextrin
1 mM	0.175 ± 0.001	41.7 ± 0.2	964	0.138 ± 0.001	40.8 ± 4.0	501
10 mM	0.172 ± 0.004	177.6 ± 13.2	216	0.152 ± 0.003	112.1 ± 5.7	336
			Tobramycin
2 μg/mL	0.149 ± 0.001	28.8 ± 7.2	480	0.136 ± 0.001	22.1 ± 0.8	134
10 μg /mL	0.275 ± 0.026	28.4 ± 0.3	399	0.205 ± 0.022	17.8 ± 9.6	52
combinedb	0.151 ± 0.001	137.0 ± 6.7	331	0.174 ± 0.003	113.1 ± 7.1	933

^aA. baumannii bound and loose EPS were investigated either untreated or in the presence of different concentrations of NaCl, maltodextrin, and tobramycin solutions in PBS, as indicated in the table.

^bApplied combined concentrations were 10 mM maltodextrin and 10 μg/mL tobramycin, both dissolved in PBS. Peak values and standard deviations were derived from distribution histograms by using the lognormal probability density function. For each set of experiment, 1024 pairs of force versus displacement curves were acquired from three different areas in the FV mode. Data represents mean ± S.D.