In Vitro Evaluation of Antimicrobial Activity and Cytotoxicity of Different Nanobiotics Targeting Multidrug Resistant and Biofilm Forming Staphylococci

Table 2

Minimum biofilm inhibitory concentrations (MBICs) of linezolid, doxycycline, and clindamycin nanobiotics against biofilms of different species of Staphylococci.

Species; (No. of Isolates)	MBIC (μg/ml) of			MBIC (μg/ml) of			MBIC (μg/ml) of
	Linezolid			Doxycycline			Clindamycin
	S (%)	`I (%)	R (%)	S (%)	I (%)	R (%)	S (%)	I (%)	R (%)
	≤ 4	-	≥ 8	≤ 4	8	≥ 16	≤ 0.5	1-2	≥ 4
S. aureus; (n=31)	27 (87.09)	-	4 (12.9)	8 (25.8)	13 (41.9)	10 (32.25)	-	2(6.45)	29 (93.54)
S. epidermidis; (n=21)	12 (57.14)	-	9 (42.86)	2 (9.52)	6 (28.57)	13 (61.9)	-	1 (4.76)	20 (95.24)
S. haemolyticus; (n=2)	2 (100)	-	-	-	-	2 (100)	-	-	2 (100)
S. lugdunensis; (n=3)	3 (100)	-	-	-	-	3 (100)	-	-	3 (100)

R= resistant; I= intermediate resistance; S= sensitive. The cutoff values proposed by the CLSI (2017) of MBIC (μg/ml): for linezolid S ≤ 4, R ≥ 8, for doxycycline S≤ 4, I=8, R ≥ 16, and for clindamycin S ≤ 0.5, I =1-2, R ≥ 4.