Journal article
Use of a Nonmedicated Dietary Supplement Correlates with Increased Prevalence of Streptomycin-Sulfa-Tetracycline-Resistant Escherichia coli on a Dairy Farm
Applied and environmental microbiology, Vol.72(7), pp.4583-4588
07/2006
Handle:
https://hdl.handle.net/2376/115238
PMCID: PMC1489318
PMID: 16820447
Abstract
We examined how a dietary supplement affects the prevalence of antibiotic-resistant
Escherichia coli
on a dairy farm in Washington State. Between 2001 and 2004 the prevalence of fecal
E. coli
strains resistant to streptomycin, sulfadiazine, and tetracycline (SSuT strains) declined from 59.2% to 26.1% in the calf population. In 2003 the dairy discontinued use of a dietary supplement, and we hypothesized that the decline in prevalence of SSuT strains was related to this change in management. To test this we established three treatments in which calves received no supplement, the dietary supplement with oxytetracycline, or the dietary supplement without oxytetracycline. Calves receiving either dietary supplement had a significantly higher prevalence of SSuT
E. coli
than the no-supplement control group (≈37% versus 20%, respectively;
P
= 0.03). Importantly, there was no evidence that oxytetracycline contributed to an increased prevalence of fecal SSuT
E. coli
. We compared the growth characteristics of SSuT and non-SSuT
E. coli
in LB broth enriched with either the complete dietary supplement or its individual constituents. Both the complete dietary supplement and its vitamin D component supported a significantly higher cell density of SSuT strains (
P
= 0.003 and
P
= 0.001, respectively). The dry milk and vitamin A components of the dietary supplement did not support different cell densities. These results were consistent with selection and maintenance of SSuT
E. coli
due to environmental components independent of antibiotic selection.
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Details
- Title
- Use of a Nonmedicated Dietary Supplement Correlates with Increased Prevalence of Streptomycin-Sulfa-Tetracycline-Resistant Escherichia coli on a Dairy Farm
- Creators
- Artashes R Khachatryan - Department of Veterinary Microbiology and PathologyThomas E Besser - Department of Veterinary Microbiology and PathologyDale D Hancock - Department of Veterinary Microbiology and PathologyDouglas R Call - Department of Veterinary Microbiology and Pathology
- Publication Details
- Applied and environmental microbiology, Vol.72(7), pp.4583-4588
- Academic Unit
- Veterinary Clinical Sciences, Department of; Veterinary Microbiology and Pathology, Department of; Paul G. Allen School for Global Animal Health
- Publisher
- American Society for Microbiology
- Identifiers
- 99900548501601842
- Language
- English
- Resource Type
- Journal article