Emerging Infectious Disease ISSN: 1080-6059

Vancomycin Heteroresistance in Methicillin-resistant Staphylococcus aureus, Taiwan

Jiun-Ling Wang*, Sung-Pin Tseng*, Po-Ren Hsueh*

, and Keiichi Hiramatsu†

Author affiliations: *National Taiwan University Hospital, Taipei, Taiwan; †Juntendo University School of Medicine, Tokyo, Japan

Characteristics of 21 methicillin-resistant Staphylococcus aureus isolates recovered from two patients with recurrent bacteremia^a

Designation of isolate	Date of isolation (mo/day/year)	Vancomycin MIC (μg/mL)					Teicoplanin MIC (μg/mL)
		Etest	Broth microdilution		Agar dilution		Agar dilution
		BHI	BHI	MHB	BHI	MHA	MHA
Patient A (89-y-old man)
A1	6/30/2000	3	2	1	2	2	2
A2	6/14/2001	4	3	1	2	2	2
A3	11/19/2001	4	4	2	2	2	2
A4	3/5/2002	4	3	1	2	2	4
A5	3/22/2002	4	3	2	3	2	4
A6	4/3/2002	6	5	4	4	2	4
A7	4/14/2002	6	5	4	4	3	4
A8	4/29/2002	5	4	2	4	3	8
A9	4/29/2002	6	3	2	4	3	4
A10	5/7/2002	6	4	2	4	2	4
Patient B (72-y-old man)
B1	4/26/2000	3	2	1	2	1	2
B2	5/6/2000	4	2	1	2	2	8
B3	5/18/2000	6	4	2	4	3	8
B4	5/29/2000	5	4	1	4	2	8
B5	6/15/2000	6	3	2	4	3	8
B6	6/24/2000	8	4	2	4	3	8
B7	7/19/2000	8	4	3	5	3	8
B8	1/9/2001	4	1	1	2	1	1
B9	1/26/2001	4	2	1	2	1	1
B10	3/21/2001	3	2	1	2	1	1
B11	4/6/2001	4	2	1	2	1	1
Mu3		3	3	2	3	2	–
Mu50		10	8	5	8	4	–

^aBHI, brain heart infusion; MHB, Mueller-Hinton broth; MHA, Mueller-Hinton agar.