Thesis
Coagulase-negative staphylococci mastitis management
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/100176
Abstract
Coagulase-negative staphylococci (CNS) are the most common pathogens associated with intramammary infections (IMI) in dairy cows. We hypothesize that post-milking teat disinfection, teat dip, would reduce the microbial colonization of the streak canal and thus reduce the prevalence of IMI caused by CNS species. The efficacy of iodine post-milking teat dip was tested against CNS colonization of the streak canal, and incidence of IMI was measured. Using an udder-half model, 43 Holstein cows at the Washington State University Dairy were enrolled in the trial; teat dip was only applied after milking to one udder-half. Streak canal swab solutions and mammary quarter milk samples were taken in duplicate once a week for 16 weeks for microbial culture. A CNS IMI was identified when two of three consecutive duplicate quarter milk samples were identified with the same CNS species containing >120 cfu/ml. The isolates were speciated using PCR-RFLP and gel electrophoresis. Colonization of the streak canal and IMI by CNS were assessed. Twenty-five CNS IMI were diagnosed; IMI were significantly reduced by 61.1% (P<0.05) in the treated quarters. The majority of CNS IMI were caused by Staphylococcus chromogenes (44%) and appeared to be linked to streak canal colonization. Conversely, the second most prevalent cause of CNS IMI was by Staphylococcus xylosus (36%), but did not appear to be linked to colonization of the streak canal. The IMI by S. xylosus and S. chromogenes were reduced by 71.4% (P <0.05) and 16.6% (P >0.05) in the treated quarters. In conclusion, the iodophor post-milking teat disinfectant was efficacious for reducing IMI caused by CNS, but CNS IMI was not necessarily linked to streak canal colonization.
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Details
- Title
- Coagulase-negative staphylococci mastitis management
- Creators
- Tracy Elizabeth Quirk
- Contributors
- Lawrence Kenneth Fox (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Animal Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525192201842
- Language
- English
- Resource Type
- Thesis