TABLE 1 .

Clinical and sampling information for all infants^a

Infant	No. of samples	Age(s) at which sample(s) was collected (days)	Age at disease onset (days)	Group	Age at birth (wks, days)	Birth wt (g)	Antibiotics administered	Delivery mode	Food	Twin set
1	2	7, 7		Control	27, 4	875		CS	BM
2	3	15, 15, 36		Control	31	1,570	AMP, GEN	CS	BM, F
3	1	19		Control	26	980	AMP, GEN	CS	BM
4	2	11, 11		Control	30, 3	1,335		V	BM
5	2	18, 18		Control	24, 5	630		CS	BM
6	4	25, 26, 28, 43		Control	28, 5	860	AMP, GEN	CS	BM, F
7	3	10, 21, 24		Control	25, 2	885		CS	BM, F
8	1	10		Control	25, 4	940	AMP, GEN	V	BM
9	1	8		Control	27, 2	1,205		V	BM
11	2	29, 29		Control	27, 4	850	AMP, GEN	V	BM
12	1	22		Control	26, 2	880	AMP, GEN	CS	BM, F	1
13	1	23		Control	26, 2	925	AMP, GEN	CS	BM, F	1
14	1	8		Control	31, 4	1,190	AMP, GEN	CS	BM
15	3	18, 40, 40		Control	28, 1	1,270	AMP, GEN	CS	BM, F	2
16	1	19		Control	28, 1	1,355	AMP, GEN	CS	BM, F	2
17	3	18, 32, 54		Control	26, 2	660	AMP, GEN	CS	BM
21	1	10		Control	28, 6	1,180	AMP, GEN	CS	BM
22	1	25		Control	28, 6	1,360	AMP, GEN	V	BM, F
24	2	27, 73		Control	26	740	AMP, GEN	CS	BM	3
25	1	28		Control	26	780	AMP, GEN	CS	BM	3
35	2	18, 18		Control	25, 5	920		CS	BM, F
23	7	14, 15, 27, 28, 30, 30, 56	27	NEC	26, 6	1,080	AMP, GEN, CTX, VAN	V	BM
28	4	31, 32, 33, 48	31	NEC	26	1,060	VAN, PIP	CS	BM, F
30	4	21, 41, 42, 56	41	NEC	23, 6	620	CFZ, AZM, AMP	V	BM, F
20	1	21	26	Septic	24, 5	815	AMP, GEN	CS	BM
10	6	15, 35, 36, 37, 39, 40	27	Septic	26, 5	940	AMP, GEN, VAN	V	BM, F
26	1	22	22	Septic	24, 4	660	AMP, GEN, CTX, VAN	CS	BM	4
27	2	22, 31	29	Septic	24, 5	650	AMP, GEN	CS	BM	4
29	2	20, 26	26	Septic	26, 1	980	CTX, VAN	CS	BM
31	5	10, 34, 35, 38, 45	34	Septic	27	710	AMP, GEN	CS	BM, F
32	4	32, 32, 53, 75	32	Septic	27, 5				BM, F
37	3	8, 17, 18	13	Septic	24, 1	680	AMP, GEN, CFZ, OXA	V	BM

^aAMP, ampicillin; CTX, cefotaxime; CFZ, cefazolin; GEN, gentamicin; OXA, oxacillin; PIP, piperacillin; VAN, vancomycin; CS, C-section; V, vaginal; BM, breast milk; F, formula.