Development of Daptomycin Resistance In Vivo in Methicillin-Resistant Staphylococcus aureus

DOI: 10.1128/JCM.43.10.5285-5287.2005

Article Figures & Data

Open in new tab
Download powerpoint
FIG. 1.
Time-kill experiments with representative daptomycin-susceptible and daptomycin-resistant methicillin-resistant Staphylococcus aureus isolates. (A) Daptomycin-susceptible isolate from patient 1. (B) Daptomycin-resistant isolate from patient 1. (C) Daptomycin-susceptible isolate from patient 2. (D) Daptomycin-resistant isolate from patient 2. Abbreviations: C, Growth control without daptomycin; 1× MIC, 2× MIC, and 4× MIC, daptomycin concentrations tested were equal to, twice, and four times higher than the MIC of daptomycin for the isolate, respectively.

TABLE 1.

Daptomycin susceptibility testing of clinical methicillin-resistant Staphylococcus aureus isolates

Isolate source	Sample type	Date of isolation (mo/day/yr)	Disk zone size (mm)^a	MIC (μg/ml)^b
Patient 1^c	Tibial tissue	12/31/03	22	0.25
	Synovial fluid	12/31/03	22	0.25
	Blood	1/2/04	22	0.25
	Blood	1/2/04	22	0.25
	Blood	1/7/04	22	0.25
	Blood	1/7/04	22	0.25
	Blood	1/8/04	22	0.25
	Blood	1/8/04	22	0.25
	Blood	1/9/04	22	0.25
	Blood	1/9/04	22	0.25
	Blood	2/12/04	18	4
	Epidural tissue	2/18/04	18	4
Patient 2^d	Blood	12/9/03	23	0.5
	Blood	3/3/04	23	0.5
	Blood	3/5/04	24	0.5
	Blood	3/7/04	24	0.5
	Blood	3/11/04	23	2
	Blood	5/2/04	19	2
	Blood	5/2/04	20	2
	Blood	5/3/04	20	2
	Blood	5/4/04	19	2
	Blood	5/6/04	19	4
	Blood	5/7/04	20	2
	Blood	5/9/04	20	2
	Blood	5/11/04	19	4
	Blood	5/11/04	19	2
	Blood	5/13/04	19	4