Table 4.

Antibiofilm activity of resveratrol against Gram-negative bacteria.

Gram types	Bacterial pathogens	Bacteria strains	Source of bacterial strain	Applied concentration	Assay	Observations	References
Gram-negative	Enterohemorrhagic E. coli O157:H7	ATCC 43895	Isolated from raw hamburger meat implicated in hemorrhagic colitis outbreak	10, 20, 50 μg/mL	Crystal violet biofilm assay	Reduction of EHEC biofilm production as low as 10 μg/mL	Lee et al., 2013
		EDL 933	Isolated from raw hamburger meat implicated in hemorrhagic colitis outbreak		Confocal laser microscopy (fluorescent)	Reduction of EHEC biofilm production on glass surface at 50 μg/mL
	commensal E. coli K-12	BW 25113	–	50, 100 μg/mL	Crystal violet biofilm assay	No inhibition of formation of biofilm of all four commensal E. coli	Lee et al., 2013
		MG1655	Derived from parent strain W1485
		TG1	–
		DH5α	–
	Campylobacter coli	873	Isolate from feces of patient with acute gastroenteritis	6.25–200 μg/mL	Crystal violet biofilm assay	200 μg/mL resveratrol resulted in 63 −94 % biofilm inhibition in all 4 strains of bacteria. For established biofilm, 200 μg/mL resveratrol resulted in 80 % biofilm inhibition for both Campylobacter strains and A.butzleri AB36/11 and a reduction of 64% for the A. butzleri INSA 776. For all strains, even at subinhibitory resveratrol concentrations, inhibited biofilm formation as well as diminished established biofilm.	Duarte et al., 2015
	Campylobacter jejuni	225421	Isolated from fresh poultry meat
	Arcobacter butzleri	AB36/11	Isolated from poultry caecum
		INSA 776	Isolated from feces of patient with diarrhea and abdominal pain
	Campylobacter jejuni	K49/4	Isolated from food	12.5 – 1565 μg/mL		Subinhibitory concentration (12.5–200 μg/mL) resulted in 40 % inhibition of biofilm formation and 20–30% inhibition at other lower concentrations. At MIC, two times and five times MIC, even higher percentage biofilm inhibition was achieved	Klancnik et al., 2017
	Vibrio cholerae O1	MCVO9	Clinical isolate from cholera outbreak	10, 15, 20, 25, 30μg/mL	Crystal violet biofilm assay	Concentration dependent inhibition of % biofilm formation. 15 – 30 μg/mL resveratrol inhibits biofilm formation by 64–85%. At 10 μg/mL, inhibition was not significant.	Augustine et al., 2014
				15,20 μg/mL	Confocal laser microscopy	Reduction of cells adhered to coverslip. Significant difference in thickness of biofilm in treated and control. At 15 μg/mL and 20 μg/mL, the measured thickness of biofilm was 18 μm and 15 μm respectively. In untreated cells, the thickness measured was 70 μm.
	Vibrio cholerae	ATCC 39315	Isolated from feces of cholera patient	10 μg/mL	Crystal violet biofilm assay	No significant reduction in % biofilm formation	Kim et al., 2015