TABLE 2.

GAS isolates for which MICs indicate resistance and MBECs indicate insensitivity by biofilm-forming efficiency

Antibiotic (dose)	No. of isolates (%)								P value for insensitivity in relation to increasing efficiency
	MIC				MBEC
	L	M	H	Total (n = 50)	L	M	H	Total (n = 30)
Penicillin (5 μg/ml)	0	0	0	0 (0.0)	6	5	7	18 (60)	0.65
Penicillin + rifampin (7 μg/ml)	0	0	1	1 (0.3)	9	9	10	28 (93)	0.38
Rifampin (7 μg/ml)	1	1	5	7 (23)	7	9	10	26 (87)	0.05
Erythromycin (2 μg/ml)	0	0	0	0 (0.0)	9	9	10	28 (93)	0.38
Clindamycin (10 μg/ml)	0	0	0	0 (0.0)	8	9	10	27 (90)	0.14
Cephalexin (18 μg/ml)	0	0	0	0 (0.0)	9	8	9	26 (87)	1.00
Ceftriaxone (270 μg/ml)	0	0	0	0 (0.0)	8	8	6	22 (73.3)	0.32

^aL, low-efficiency biofilm formation (≤10³); M, medium-efficiency biofilm formation (>10³, ≤10⁴); H, high-efficiency biofilm formation (>10⁴).