Mutations upstream of fabI in triclosan resistant Staphylococcus aureus strains are associated with elevated fabI gene expression

Table 1 Genotypes and phenotypes of in vitro mutants and clinical isolates with fabI promoter mutations

Strain	Background	*sa-fabI* promoter**	sa - *fabI* ^‡	sh - *fabI* ^‡	MIC* ^‡	MBC* ^‡	Comment
RN4220	-	wt	wt	-	1	2
MW2	-	wt	wt	-	0.12	0.12
ATCC6538	-	wt	wt	-	0.12	0.25
MO036	RN4220	A7G	mutated	-	4	8
MO035	RN4220	C34T	mutated	-	8	8
MO047	RN4220	C34T	mutated	-	4	8
MO049	RN4220	C34T	mutated	-	4	8
MO076	MW2	C34T	mutated	-	4	8
CR002	ATCC6538	C34T	mutated	-	4	8
MO034	RN4220	A72G	mutated	-	8	8
MO077	MW2	A101-	mutated	-	4	32	1 bp deletion
d7	ATCC6538	A101-	mutated	-	2	8	1 bp deletion
MO051	ATCC6538	T109G	mutated	-	4	8
MO052	ATCC6538	T109G	mutated	-	8	16
MO053	ATCC6538	T109G	mutated	-	4	8
MO055	ATCC6538	T109G	mutated	-	4	8
QBR-102278-1097	-	C34T	mutated	-	0.25	32
QBR-102278-1889	-	C34T	wt	-	0.5	16
QBR-102278-1969	-	C34T	wt	-	0.25	32
QBR-102278-2095	-	C34T	wt	-	0.25	32
QBR-102278-2546	-	C34T	mutated	+	1	64
QBR-102278-2363	-	A101C	wt	+	16	32
QBR-102278-1052	-	T109G	wt	+	0.5	64	IS256 insertion

*MIC and MBC to triclosan are expressed as mg/L. **Polymorphic sites are indicated counting backwards from the sa-fabI start site of S. aureus Mu50 (GenBank ID: BA000017; position 1060308). Strains analysed by microarray are indicated in bold. ^‡With the exception of strain QBR-102278-2095, these data have been previously reported [22].

ISSN: 1471-2164