. 2015 Mar 30;47(1):27–32. doi: 10.3947/ic.2015.47.1.27

Table 3. Comparison of anti-biofim effects of diverse antibiotics on VIM-2 Acinetobacter baumannii after 96 hours of incubation.

	Antibiotic concentration	OD₅₇₀±SD	P-valuea	Biofilm reduction (%)
Negative control^b	-	0.55±0.15	-	-
Positive control^c	-	11.29±0.16	-	-
Tigecycline^d	MIC (2 mg/L)^e	0.53±0.05	<0.01	95.3
	1/2 MIC (1 mg/L)	0.80±0.14	<0.01	92.9
	1/4 MIC (0.5 mg/L)	0.96±0.09	<0.01	91.5
Colistin-rifampicin^d	MIC (2 mg/L)^f - MIC (8 mg/L)^g	0.60±0.12	<0.01	94.7
Colistin-rifampicin^d	1/2 MIC (1 mg/L)- MIC (8 mg/L)	0.85±0.18	<0.01	92.5
Imipenem-rifampicin^d	MIC (64 mg/L)^h- MIC (8 mg/L)	0.60±0.13	<0.01	94.7
	1/2 MIC (32 mg/L)- MIC (8 mg/L)	0.56±0.64	<0.01	95.0
	1/4 MIC (16 mg/L)- MIC (8 mg/L)	0.62±0.23	<0.01	94.5

^aComparison between positive control and each antibiotic regimen.

^bNegative control; tests were carried out 18 times and the results were expressed as the mean ± SD.

^cPositive control means OD values from the wells where bacteria were inoculated without antibiotics; tests were carried out 18 times and the results were expressed as the mean ± SD.

^dTests were carried out six times and the results were expressed as the mean ± standard deviation.

^eSusceptible ≤2, resistant ≥8 by Wyeth research.

^fSusceptible ≤4, resistant ≥8 by British Society for Antimicrobial Chemotherapy.

^gSusceptible ≤2, resistant ≥4 by working party report of the British Society for Antimicrobial Chemotherapy.

^hSusceptible ≤4, resistant ≥16 by CLSI.

VIM, verona imipenemase; OD, optical density; SD, standard deviation; MIC, minimum inhibitory concentration; CLSI, Clinical and Laboratory Standards Institute.