Staphylococcus epidermidis strains isolated from breast milk of women suffering infectious mastitis: potential virulence traits and resistance to antibiotics

Table 2 Distribution of MIC's to several antibiotics among S. epidermidis isolated from mastitis and healthy women

			Percentage of strains for which the MIC (μg mL^-1) was as follows:
Antibiotics	Breast milk	N° of strains	≤ 0.03	0.12	0.25	0.5	1	2	4	8	> 8
PEN	H	36	17	8		8	14	14	8	11	19
	M	40	10	5	5	8	10	33	8	8	18
AMP				≤ 0.12	0.25	0.5	1	2	4	8	100	> 100
	H	36		19	6	17	22	8	8	6	14
	M	40		15	8	5	23	20	10	5	13	3
OXA					≤ 0.25	0.5	1	2	> 2
	H	36			11	31	11	8	39
	M	40			5	8	13	8	68
CIP					≤ 0.25	0.5	1	2	> 2
	H	36			47	39	8		6
	M	40			30	38	18	3	13
CHL										≤ 8	16	> 16
	H	36								75	17	8
	M	40								78	10	13
ERY					≤ 0.25	0.5	1	2	4	> 4
	H	36			39	14	6	8		33
	M	40			23	15			3	60
CLI						≤ 0.5	1	2	> 2
	H	36				81	8	3	8
	M	40				70	3		28
TET									≤ 4	8	> 8
	H	36							56	19	25
	M	40							68	8	25
VAN						≤ 0.5	1	2	4	8	16	≥ 16
	H	36					44	50	6
	M	40					43	48	5	3	3
MUP									≤ 4	256	> 256
	H	36							78	11	11
	M	40							58	13	30

H: strains isolated from healthy women; M: strains isolated from mastitis-suffering women; PEN: penicillin; AMP: ampicillin; OXA: oxacillin; CIP: ciprofloxacin; CHL: chloramphenicol; ERY: erythromycin; CLI: clindamycin; TET: tetracycline; VAN: vancomycin; MUP: mupirocin.
Statistically-significant differences between isolates from mastitis and healthy women are in bold.

ISSN: 1471-2180