Previous Article | Next Article ![]()
Antimicrobial Agents and Chemotherapy, September 2006, p. 2912-2918, Vol. 50, No. 9
0066-4804/06/$08.00+0 doi:10.1128/AAC.01630-05
Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Department of Food Science and Canadian Research Institute for Food Safety, University of Guelph, Guelph, Ontario N1G 2W1,1 Agriculture and Agri-Food Canada, Food Research Program, 93 Stone Rd. W., Guelph, Ontario N1G 5C9,2 Department of Population Medicine, University of Guelph, Guelph, Ontario N1G 2W1, Canada3
Received 22 December 2005/ Returned for modification 28 March 2006/ Accepted 18 June 2006
Bovine mastitis is an inflammation of the udder caused by microbial infection. Mastitis caused by Staphylococcus aureus is a major concern to the dairy industry due to its resistance to antibiotic treatment and its propensity to recur chronically. Growing concerns surrounding antibiotic resistance have spurred research into alternative treatment methods. The ability of lytic S. aureus bacteriophage K to eliminate bovine S. aureus intramammary infection during lactation was evaluated in a placebo-controlled, multisite trial. Twenty-four lactating Holstein cows with preexisting subclinical S. aureus mastitis were treated. Treatment consisted of 10-ml intramammary infusions of either 1.25 x 1011 PFU of phage K or saline, administered once per day for 5 days. The cure rate was established by the assessment of four serial samples collected following treatment. The cure rate was 3 of 18 quarters (16.7%) in the phage-treated group, while none of the 20 saline-treated quarters were cured. This difference was not statistically significant. The effects of phage intramammary infusion on the bovine mammary gland were also studied. In healthy lactating cows, a single infusion of either filter-sterilized broth lysate or a CsCl gradient-purified phage preparation elicited a large increase in the milk somatic cell count. This response was not observed when phage was infused into quarters which were already infected with S. aureus. Phage-infused healthy quarters continued to shed viable bacteriophage into the milk for up to 36 h postinfusion. The phage concentration in the milk suggested that there was significant degradation or inactivation of the infused phage within the gland.
Submitted as Agriculture and Agri-Food Canada (Research Branch) manuscript no. S244.
This article has been cited by other articles:
Copyright © 2010 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»