Table 1. Biofilm formation capacity of tested bacteria (crystal violet assay).

Bacteria	Strain characteristics	Optical density A570 nm, units		P*	Biofilm formation capacity
		Control	1 day biofilm
E. coli ATCC 25922	Antibiotic sensitive	0.1 ± 0.002	0.7 ± 0.05	<0.001	High
E. coli NCTC 13353	Beta-lactamase producing	0.1 ± 0.004	0.1 ± 0.03	0.17	Low
S. aureus 203	Antibiotic sensitive	0.1 ± 0.002	1.1 ± 0.08	<0.001	High
S. aureus 73.1	Azitromycin resistant	0.1 ± 0.01	0.3 ± 0.03	0.03	Intermediate
A. baumannii 28	Antibiotic multiresistant	0.1 ± 0.002	0.6 ± 0.04	<0.001	High
A. baumannii 143	Antibiotic multiresistant	0.1 ± 0.01	0.26 ± 0.03	0.02	Intermediate
A. baumannii 149.2	Antibiotic multiresistant	0.1 ± 0.01	0.8 ± 0.09	0.002	High

*P–statistical significance of differences in optical density compared to control wells without added bacteria. Each test consisted of 3 independent measurements.