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

Table 2 Polymorphic changes in the genome of in vitro mutant strains

Ref. genome positions*		Annotation	RN4220 derived			ATCC6538 derived			Mu50 derived
NCTC8325	Mu50	Annotation	MO034	MO035	MO036	d2**	d7	MO052	MO079**
120767		Capsular polysaccharide synthesis enzyme Cap5B					A 592 T – Met 198 Leu
208900		Pyruvate formate-lyase 1-activating enzyme						G 721 T - Val 241 Phe
226813		Flavohemoprotein					-TA 953 deletion leading to transcription premature truncation
784247		Protein traslocase subunit SecG					T 22 A – Leu 8 Ile
919922		fabI upstream region**						T 109 G
919929		fabI upstream region					A 101 deletion
919959		fabI upstream region	A 72 G
919997		fabI upstream region		C 34 T
920024		fabI upstream region			A 7 G
920098		fabI coding region		G 68 C – Gly 23 Ala
920331		fabI coding region	G 301 T – Asp 101 Tyr		G 301 T – Asp 101 Tyr
920469		fabI coding region					T 439 C – Tyr 147 His
920641		fabI coding region				T 611 G – Phe 204 Cys		T 611 G – Phe 204 Cys
	1060928	fabI coding region							T 611 A – Phe 204 Tyr
1139511		serine/threonine-protein kinase PrkC					G 1309 A – Val 437 Ile
1231020		DNA mismatch repair protein MutL						T 1709 A – Ile 569 Asn
	1238213	MurD UDP-N-acetylmuramoyl-L-alanyl-D-glutamate synthetase							T 338 G – Ile 113 Ser
	1238872	MurD UDP-N-acetylmuramoyl-L-alanyl-D-glutamate synthetase							C 997 G – Leu 333 Val
1588812		tRNA methylthiotransferase YqeV					G 824 A – Ile 275 Thr
2335216		HTH-type transcriptional regulator SarV					C 140 A – Val 47 Gly
2774594		Ica operon transcriptional regulator, IcaR					-TCTTTTGTCA 417 deletion leading to transcription premature truncation

*The nucleotide position refers to the genome of S. aureus NCTC8325 (accession NC_007795) or Mu50 (accession NC_002758). Polymorphic sites of fabI promoter region are indicated counting backwards from the sa-fabI start site of S. aureus Mu50 (GenBank ID: BA000017; position 1060308). **Despite not having fabI promoter mutations the d2 and MO079 mutants have been included in the analysis to check for the presence of mutations (not only in the fabI coding sequence) playing a possible role in triclosan reduced susceptibility.

ISSN: 1471-2164