Selective digestive decontamination solution used as “lock therapy” prevents and eradicates bacterial biofilm in an in vitro bench-top model

Table 1 Overall data of live cells, cfu/ml counts, and percentage of reduction of bacterial biofilms after prophylaxis and treatment with selective digestive decontamination solution

Therapy	MO	Median (IQR) % live cells		Median (IQR) % reduction of live cells	P value	Median (IQR) log₁₀ cfu/ml*		Median (IQR) % reduction** of cfu/ml*	P value
Therapy	MO	C+	ALT	Median (IQR) % reduction of live cells	P value	C+	ALT	Median (IQR) % reduction** of cfu/ml*	P value
Treatment	P. aeruginosa	88.9 (84.4–93.4)	39.3 (30.1–50.9)	53.2 (39.4–64.1)	< 0.001	7.5 (7.4– ^b)	-^a	100.0 (100.0–100.0)	0.002
	E. coli	55.9 (49.6–67.3)	18.8 (12.5–31.2)	67.9 (46.7–78.7)	0.002	7.0 (6.7–7.4)	-^a	100.0 (100.0–100.0)	0.002
	S. aureus	42.9 (28.7–57.5)	0.0 (0.0–0.0)	100.0 (100.0–100.0)	0.007	7.7 (7.5–7.9)	-^a	100.0 (100.0–100.0)	0.002
Prophylaxis	P. aeruginosa	83.1 (77–88.4)	0.0 (0.0–0.0)	100.0 (100.0–100.0)	< 0.001	7.4 (6.9–8.4)	-^a	**Absence	0.004
	E. coli	43.9 (34.1–46.1)	0.0 (0.0–0.0)	100.0 (100.0–100.0)	<0.001	7.2 (6.9–7.34)	-^a	**Absence	0.002
	S. aureus	32.7 (23.7–49.7)	0.0 (0.0–0.0)	100.0 (100.0–100.0)	0.008	7.6 (7.4–7.8)	-^a	**Absence	0.002

P values were obtained using Mann–Whitney U test
MO microorganism, IQR interquartile range, cfu colony forming units, C + positive control, ALT antibiotic lock therapy
^aNo cells were recovered after therapy. Cfu/ml resulted to be 0 (0.0-0.0) for all microorganisms after every therapy being log₁₀ of 0 in-calculated
^bNo p75 value obtained
^*Limit of detection of cfu counting using conventional culture was 10 cfu/ml
**In prophylaxis therapy, no reduction could be measured, as there was no pre-formed biofilm. Results are expressed as absence

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