TABLE 1.

Twelve E. coli strains tested for pathogenicity for kidneys

SSI no.a	Serotype and virulence factors	Origin	No. of infected kidneys/total no.	Range of no. of CFU/kidney	Median no. of CFU/kidney
C175-94	O8:K48:H9, type 1 fimbriae	Fecesb	5/6	0–3.4 × 107	1.8 × 105
C165-94	O2:K13:H1, type 1 fimbriae, hly+d	Fecesc	4/6	0–3.2 × 106	3.0 × 104
C760-85	O1:K1:H7, type 1 fimbriae	Unknown	4/6	0–6.6 × 106	2.2 × 104
C711-92	O18ac:K5:H−	Bloode	5/6	0–3.6 × 105	7.8 × 103
C190-92	O15:K52:H1, P fimbriae	Blood	6/10	0–2.2 × 105	3.5 × 103
C153-94	O1:K1:H−, P fimbriae, hly+	Cervixf	4/6	0–6.2 × 103	5.1 × 102
C263-93	O2:K2:H1, hly+	Urine	3/6	0–1.1 × 105	40
C178-94	O2:K1:H6, P fimbriae, hly+	Urine	3/6	0–1.2 × 106	0
C561-93	O2:K1:H7	Urine	2/6	0–3.8 × 104	0
C309-94	O6:K2:H1, hly+	Urineg	3/10	0–7.4 × 104	0
C236-94	O12:K1:H7	Unknown	1/6	0–1.5 × 106	0
D2103-4	Orough:H−	Laboratory	0/10	0	0
Control	PBS		0/6	0	0

^aThe strains denoted C were isolated from patients with UTIs. Strain D2103-4 is a nonvirulent laboratory strain. 

^bIsolated from feces after a febrile UTI in a male. 

^cIsolated from feces during a febrile UTI in a male. 

^dhly+, hemolysin positive. 

^eIsolated from a patient with bacteremia caused by a UTI. 

^fIsolated from the asymptomatic female partner at the time of febrile UTI in a male. 

^gIsolated from a boy with relapse of cystitis.