TABLE 1.

Numbers of Enterococcus species isolates screened for the optrA gene and the positive rate from 2004 to 2014 in China^a

Yr and species	No. of isolates	LZDb MIC50 (mg/liter)	LZD MIC90 (mg/liter)	No. optrA positive	Percentage (%)
2004-2005
E. faecalis	125	NDc	ND	0	0
E. faecium	115	ND	ND	1	0.9
Other Enterococcus spp.	22	ND	ND	0	0
Overall	262			1	0.4
2007-2008
E. faecalis	158	ND	ND	1	0.6
E. faecium	149	ND	ND	0	0
Other Enterococcus spp.	39	ND	ND	0	0
Overall	346			1	0.3
2009-2010
E. faecalis	113	2	2	6	5.3
E. faecium	195	1	2	1	0.5
Other Enterococcus spp.	36	1	2	0	0
Overall	344			7	2.0
2011-2012
E. faecalis	276	1	2	8	2.9
E. faecium	304	1	2	1	0.3
Other Enterococcus spp.	1	—d	—	1	100
Overall	581			10	1.7
2013-2014
E. faecalis	315	2	2	22	7.0
E. faecium	352	2	2	3	0.9
Other Enterococcus spp.	1	—	—	1	100
Overall	668			26	3.9
2004-2014
E. faecalis	987	2e	2e	37	3.7
E. faecium	1,115	1e	2e	6	0.5
Other Enterococcus spp.	99	1e	2e	2	2.0
Overall	2,201			45	2.0

^aThe Center Net of Mohnarin program and CARST program collected the isolates from the middle of one year to the middle of the following year.

^bLZD, linezolid.

^cND, not detected.

^d—, linezolid MIC₅₀ and MIC₉₀ were not calculated.

^eMIC₅₀ and MIC₉₀ were calculated according to the MICs of isolates screened from 2009 to 2014.