Table 1. Strains carrying the SXT element and the molecular characteristics of their SXT elements.

Strain	Province	Source	Year isolated	Length of SXT (bp)	Number of ORFs	G+C (%)	Resistance genes
ICDC-VC1605	Guangdong	Patient	1993	98419	87	47.43	sul2, strAB, dhfR, folR
ICDC-VC1627	Guangdong	Patient	1997	102413	92	47.93	sul2, strAB, dhfR, tetAR, merR, folR
ICDC-VC2605	Guizhou	Patient	1998	98458	87	47.42	sul2, strAB, dhfR, folR
ICDC-VC1909	Xinjiang	Patient	1998	108995	93	47.47	sul2, strAB, dhfR, folR
ICDC-VC4210	Jiangxi	Patient	1999	110349	99	47.81	sul2, strAB, dhfR, tetAR, merR, folR
ICDC-VC1944	Guangxi	Unknown	2000	100703	89	47.45	sul2, strAB, dhfR, folR
ICDC-VC0143	Guangdong	Patient	2001	98459	87	47.42	sul2, strAB, dhfR, folR
ICDC-VC0956	Liaoning	Water	2001	109322	94	47.89	sul2, strAB, dhfR, tetAR, merR, folR
ICDC-VC57	Fujian	Patient	2005	96153	93	46.24	dfrA1, bcr, sul2, strAB, tetAR,
ICDC-VC2255	Hainan	Patient	2008	92592	95	46.51	dfrA1, bcr, sul2, strAB, tetAR
AHV1003	Anhui	Patient	2010	101856	102	47.46	dfrA1, bcr, sul2, strAB, tetAR, mphRK, mrx