Table 3.

Results from the univariable logistic regression analysis of variables significantly (P ≤ 0.20) associated with Escherichia coli isolates (n = 95) with or without antimicrobial resistance (from 95 healthy or diarrheic calves from 85 Swedish dairy herds).

Variable	Level	E. coli with antimicrobial resistance	E. coli without antimicrobial resistance	P-value
Herd factors
Age at sampling	0: 0-11 days	24	10
	1: 12-21 days	13	16
	2: ≥ 22 days	19	10	0.09*
Any respiratory syndromes	0: No	50	33
	1: Yes	7	1	0.10
Herd size (no of cows)	0: < 55	14	17
	1: 55-120	20	13
	2: ≥ 121	21	6	0.04*
Time for separation of cow and calf	0: < 24 h after calving	33	14
	1: 1-3 days after calving	12	10
	2: > 3 days after calving	9	12	0.09*
Usage of DHS tablets to treat diarrhea	0: Never	40	21
	1: Sometimes/Often	15	15	0.20*
Presence of virulence genes
Presence of espP	0: No	11	19
	1: Yes	15	3	0.002*
Presence of irp	0: No	12	19
	1: Yes	14	3	0.003*
Presence of fyuA	0: No	13	18
	1: Yes	13	4	0.02*

* variables eligible for entering the multivariable analysis