

@article {13672,
	title = {{Shedding of Escherichia coli O157:H7 in dairy cattle housed in a confined environment following waterborne inoculation}},
	journal = {Applied and Environmental Microbiology},
	volume = {68},
	number = {4},
	year = {2002},
	month = {apr},
	pages = {1947{\textendash}1954},
	abstract = {A study of Escherichia coli O157:H7 transmission and shedding was conducted with bull calves housed in individual pens within a confined environment. For comparative purposes, the numbers and duration of E. coli O157:H7 shedding in naturally infected calves were monitored after a single purchased calf (calf 156) tested positive prior to inoculation. During the next 8 days, the calves in adjacent pens and a pen directly across a walkway from calf 156 began to shed this serotype O157:H7 strain. Five of the eight calves in this room shed this O157:H7 strain at some time during the following 8 weeks. The numbers of E. coli O157:H7 isolates shed in these calves varied from 60 to 10(5) CFU/g of feces, and the duration of shedding ranged from 17 to {\textgreater}31 days. The genomic DNAs from isolates recovered from these calves were indistinguishable when compared by using XbaI digestion and pulsed-field gel electrophoresis. Inoculation of calves with 1 liter of water containing ca. 10(3) to 10(4) CFU of E. coli O157:H7/ml resulted in shedding in 10 of 12 calves (trial 1, 4 of 4 calves; trial 2, 6 of 8 calves). The inoculated calves shed the inoculation strain (FRIK 1275) as early as 24 h after administration. The duration of shedding varied from 18 to {\textgreater}43 days at levels from 10(2) to 10(6) CFU/g of feces. The numbers of doses necessary to initiate shedding varied among calves, and two calves in trial 2 never shed FRIK 1275 after four doses (ca. 10(6) CFU per dose). Results from this study confirm previous reports of animal-to-animal and waterborne dissemination of E. coli O157:H7 and highlight the need for an effective water treatment to reduce the spread of this pathogen in cattle.},
	keywords = {Animal, Animals, Cattle, Cattle Diseases, Cattle Diseases: microbiology, Cattle Diseases: transmission, Colony Count, Dairying, E.coli, Escherichia coli Infections, Escherichia coli Infections: microbiology, Escherichia coli Infections: transmission, Escherichia coli Infections: veterinary, Escherichia coli O157, Escherichia coli O157: classification, Escherichia coli O157: genetics, Escherichia coli O157: isolation {\&} purification, Feces, Feces: microbiology, Fresh Water, Fresh Water: microbiology, Housing, Microbial},
	isbn = {0099-2240},
	issn = {00992240},
	doi = {10.1128/AEM.68.4.1947-1954.2002},
	author = {Shere, J. A. and Kaspar, C. W. and Bartlett, K. J. and Linden, S. E. and Norell, B. and Francey, S. and Schaefer, D. M.}
}
