Table 3.

Distribution of iron acquisition systems in 231 Cronobacter strains

Iron acquisition system system	Gene	No. (%) of isolates PCR positive for target gene
		C. sakazakii (n = 180)	C. malonaticus (n = 25)	C. turicensis (n = 6)	C. muytjensii (n = 12)	C. dublinensis (n = 6)	C. universalis (n = 2)
Ferric transporter
Cronobactin	iucC	179 (99)	25 (100)	6 (100)	9 (75)	5 (83)	2 (100)
Enterobactin	entF	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	fepE	180 (100)	25 (100)	6 (100)	12 (100)	2 (33)	2 (100)
	entE	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	fepG	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
FhuABCD	fhuA	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	fhuB	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
EitABCD	eitA	179 (99)	25 (100)	6 (100)	9 (75)	5 (83)	2 (100)
Ferric dicitrate	fecR	26 (14)	4 (16)	0 (0)	0 (0)	0 (0)	0 (0)
	fecE	26 (14)	4 (16)	0 (0)	0 (0)	0 (0)	0 (0)
Ferrous transporter
FeoABC	feoB	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
EfeUOB	efeB	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	efeO	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
Ferric reductase	viuB	179 (99)	25 (100)	6 (100)	9 (75)	5 (83)	2 (100)
	fhuF	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
TonB receptor	fcuA	0 (0)	0 (0)	0 (0)	12 (100)	6 (100)	0 (0)
	fct	0 (0)	0 (0)	3 (50)	12 (100)	6 (100)	0 (0)
	yncD	179 (99)	25 (100)	6 (100)	12 (100)	5 (83)	2 (100)
	btuB	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	foxA	175 (97)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	fhuE	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
	pfeA	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)
Heme iron extractor	yfeX	180 (100)	25 (100)	6 (100)	12 (100)	6 (100)	2 (100)