Table 2.

Population (log₁₀ CFU/filter)^a of Escherichia coli O157:H7 and Staphylococcus aureus as biofilms formed on the surfaces of glass filters before and after treatment with water or chemical sanitizers

Strains	Adhered formb	None	Distilled water	Type of chemical sanitizer
				Alcohol-based	Chlorine-based	Hydrogen peroxide-based	Iodophor-based	Quaternary ammonium-based
Escherichia coli O157:H7	Adhered cell	8.08 ± 1.08Ccad	6.50 ± 0.17Db	3.45 ± 0.62Cd	4.78 ± 0.48Cc	4.45 ± 0.15Cc	7.82 ± 0.19Ca	4.70 ± 0.35Bc
	Biofilm (type I)	10.03 ± 0.48Ba	9.58 ± 0.10Cab	5.42 ± 0.86Bcd	4.54 ± 0.24Cd	6.25 ± 1.65Bc	8.45 ± 0.38Bb	5.37 ± 0.78Bcd
	Biofilm (type II)	10.26 ± 0.28ABa	10.85 ± 0.49Aa	7.89 ± 0.17Ac	7.64 ± 0.92Bc	7.59 ± 1.63ABc	9.58 ± 0.16Aab	8.76 ± 0.64Abc
	Biofilm (type III)	10.76 ± 0.03Aa	10.22 ± 0.38Bb	8.88 ± 0.23Ad	9.34 ± 0.34Acd	9.40 ± 0.27Ac	9.34 ± 0.28Acd	9.12 ± 0.06Acd
Staphylococcus aureus	Adhered cell	9.12 ± 1.08ABa	8.45 ± 0.31Bab	5.60 ± 0.37Db	5.22 ± 0.48Db	6.48 ± 1.18Bcd	8.82 ± 0.18Bab	5.50 ± 1.11Bbc
	Biofilm (type I)	8.69 ± 0.15Ba	8.83 ± 0.98Ba	5.19 ± 0.47Bc	5.71 ± 0.29Bbc	6.44 ± 0.70Bb	7.98 ± 0.41Ca	8.18 ± 0.41ABa
	Biofilm (type II)	9.17 ± 0.86ABa	8.81 ± 0.11Ba	5.81 ± 0.95Bb	5.73 ± 2.41Bb	7.70 ± 2.03ABab	8.71 ± 0.29Ba	7.76 ± 0.87Bab
	Biofilm (type III)	10.36 ± 0.19Aa	10.25 ± 0.32Aa	7.88 ± 1.30Ba	9.63 ± 0.20Aa	9.81 ± 0.14Aa	9.62 ± 0.40Aa	9.32 ± 0.36Aa

^aData represent the means ± standard deviations of three measurements

^bAdhered cells were prepared by drying GFFs for 2 h following inoculation; type I biofilms were formed by immersing inoculated GFFs in TSB for 3 days at 28 °C; type II biofilms were formed by cultivation on inoculated GFFs on TSA for 1 days at 28 °C; type III biofilms were formed by cultivation on inoculated GFFs on TSA under 100% RH for 3 days at 28 °C

^cMeans with the same letter within a column for each pathogen are not significantly different (P > 0.05)

^dMeans with the same letter within a row for water and chemical sanitizer are not significantly different (P > 0.05)