Effects of Lysozyme, Proteinase K, and Cephalosporins on Biofilm Formation by Clinical Isolates of Pseudomonas aeruginosa

Table 5

Effects of lysozyme (30 μg/mL) and 50 times MIC of ceftazidime or cefepime alone or in combination on biofilm mass reduction (%) for P. aeruginosa clinical isolates.

Isolate code	Lysozyme (30 μg/mL)	Ceftazidime (50 × MIC)	Cefepime (50 × MIC)	Lysozyme (30 μg/mL) + ceftazidime (50 × MIC)	Lysozyme (30 μg/mL) + cefepime (50 × MIC)
B3	18.4	60.4	87.5	69.9	83.7
B5	11.9	36.9	44.8	39.4	40.7
Cl1	5.3	8.9	13.6	9.2	2.6
Cl3	30.6	50.7	76.4	65	89.5
Cl4	14	21.5	30.5	22.9	38.6
E4	44.8	68.1	86.7	83	95.7
S13	4.3	22.4	10.9	7.8	19.7
U7	12.9	21.2	37.1	32	46.8
U16	1.5	5.6	25.5	18.3	57.2
U19	7.4	11	14.4	12.5	17.4
U25	5.9	45.5	47.2	43.4	46.2
U30	10.8	32.5	45.1	36.9	50.7
Uc2	13.6	35.3	44.8	41.8	47.3
W10	12	49.1	89.6	86	94.8
W12	8.2	10.4	15	12.4	17.9
W14	35.9	45.8	38.8	48.9	41.5
Average ± SE	14.8 ± 0.75	32.8 ± 1.2	44.2 ± 1.7	39.3 ± 1.61	49.3 ± 1.79

The percentage of biofilm reduction for each isolate was determined after normalization to negative controls that were not treated with lysozyme or antibiotics. Averages are the means ± standard errors of the means from four independent experiments. B: burn; Cl: contact lens; E: eye; S: sputum; U: urine; Uc: urinary catheter; W: wound.