TABLE 5.

Effects of biocidal treatments on matrices and viable bacteria of S. aureus and P. aeruginosa biofilms

Organism and test product	Concn (%)	Neutralizer	% reduction in biofilmb (avg ± SD) after contact time of:										Categoryc
			1 min		5 min		15 min		30 min		60 min
			Matrix	Bacteria	Matrix	Bacteria	Matrix	Bacteria	Matrix	Bacteria	Matrix	Bacteria
Staphylococcus aureus
Ethanol	70	No Na	—	89 ± 4**	—	96 ± 4**	—	96 ± 0.1**	—	96 ± 0.1**	—	99 ± 0.4**	C
Isopropanol	70	No N	—	94 ± 0.8**	—	96 ± 0.1**	—	96 ± 0.4**	—	97 ± 0.3**	—	98 ± 0.6**	C
Chlorhexidine-digluconate	1	N10	—	84 ± 2**	—	95 ± 1**	—	95 ± 0.2**	—	95 ± 0.7**	—	97 ± 0.2**	C
Chloramine-T	1.25	No N	—	93 ± 7**	—	96 ± 4**	—	99 ± 0.1**	—	99 ± 0.5**	—	99 ± 0.1**	C
Povidone-iodine	10	N1	—	77 ± 0.5**	—	79 ± 3**	—	86 ± 6**	—	90 ± 4**	—	94 ± 5*	C
Sodium hypochlorite	1	No N	—	99 ± 0.5**	21 ± 8*	99 ± 0.3**	45 ± 1**	99 ± 0.8**	54 ± 6**	99 ± 0.6**	55 ± 3**	99 ± 0.5**	D
Hydrogen peroxide	5	No N	89 ± 3**	84 ± 0.4**	85 ± 8**	83 ± 2**	83 ± 9**	82 ± 6**	87 ± 3**	82 ± 4**	84 ± 7**	80 ± 0.3**	D
Peracetic acid	0.3	No N	—	98 ± 0.2**	—	99 ± 0.4**	—	99 ± 0.4**	—	99 ± 0.1**	—	99 ± 0.2**	C
Chloroxylenol	0.25	N7	—	82 ± 8**	—	87 ± 6**	—	91 ± 7**	—	94 ± 2**	—	94 ± 2**	C
Benzalkonium chloride	0.1	N7	—	53 ± 9**	—	72 ± 9**	—	86 ± 3**	—	87 ± 4**	—	84 ± 6**	C
Cetrimide	1	N9	—	78 ± 8**	—	93 ± 1**	—	92 ± 2**	—	91 ± 2**	—	91 ± 3**	C
Nitrofurazone	0.2	No N	—	—	—	—	—	—	—	—	—	—	A
Pseudomonas aeruginosa
Ethanol	70	No N	—	89 ± 7**	—	90 ± 2**	—	96 ± 4**	—	97 ± 3**	—	96 ± 1**	C
Isopropanol	70	No N	—	79 ± 1**	—	96 ± 1**	—	99 ± 2**	—	>99.999**	—	>99.999**	C
Chlorhexidine-digluconate	1	N10	—	—	—	—	—	—	—	40 ± 7**	—	57 ± 7**	C
Chloramine-T	1.25	No N	—	95 ± 0.1**	—	95 ± 1**	—	94 ± 1**	—	94 ± 1**	—	94 ± 2**	C
Povidone-iodine	10	N1	—	94 ± 0.1**	—	94 ± 1**	—	91 ± 4**	—	91 ± 5**	—	96 ± 1**	C
Sodium hypochlorite	1	No N	66 ± 3**	92 ± 9**	76 ± 9**	93 ± 8**	91 ± 2**	94 ± 6**	85 ± 2**	95 ± 7**	92 ± 1**	94 ± 7**	D
Hydrogen peroxide	5	No N	68 ± 4**	48 ± 8**	75 ± 7**	80 ± 7**	78 ± 5**	97 ± 4**	78 ± 7**	98 ± 3**	85 ± 6**	99 ± 1**	D
Peracetic acid	0.3	No N	—	99 ± 0.3**	—	99 ± 0.1**	—	98 ± 0.8**	—	98 ± 0.4**	—	99 ± 0.1**	C
Chloroxylenol	0.25	N7	—	77 ± 5**	—	86 ± 4**	51 ± 5*	84 ± 3**	55 ± 23*	82 ± 8**	66 ± 24*	85 ± 7**	D
Benzalkonium chloride	0.1	N7	—	72 ± 7**	—	69 ± 6**	—	71 ± 7**	—	75 ± 4**	—	86 ± 5**	C
Cetrimide	1	N9	—	69 ± 3**	—	70 ± 5**	—	67 ± 8**	—	77 ± 8**	—	88 ± 4**	C
Nitrofurazone	0.2	No N	—	—	—	—	—	24 ± 6*	—	32 ± 4**	—	33 ± 5**	C

^aNo N, no neutralizer.

^bLevels of significance, as determined by ANOVA, are indicated as follows: —, P > 0.05 (no significant activity); *, P < 0.05; **, P < 0.01.

^cBiocides can be classified according to their activities on matrices and bacteria. See Table 6 for descriptions of categories.