A52-75-2007E.pdf - AgroMedia International Inc

Health57Efficacy and pharmacokinetics of bacteriophage therapy intreatment of subclinical Staphylococcus aureus mastitis in lactatingdairy cattleCorresponding AuthorSabour, P.M.AAFC Food Research ProgramCollaboratorsGill, J.J.University of GuelphPacan, J.C.University of GuelphCarson, M.E.University of GuelphLeslie, K.E.University of GuelphGriffiths, M.W.University of GuelphAntimicrobial Agents and Chemotherapy (2006) Vol. 50 p. 2912-2918.Staphylococcus aureus (SA) is the most costly and problematic pathogeninvolved in intramammary infections (IMI) causing mastitis in dairy cattle.Poor cure rates and the continued emergence of multiple drug resistantstrains of SA have prompted the search for alternative treatments. Onesuch potential alternative is the use of bacteriophages (phages) – virusesthat infect bacteria. The objective of this study was to test the efficacy ofphage therapy in the treatment of lactating cows infected with SA. Thirteencows (18 quarters) received an intramammary infusion of phage K, whichhas been shown to lyse (kill) SA in broth culture. Eleven control cows (20quarters) were infused with saline. All infusions were administered daily for5 days after which milk samples were drawn for assessment of efficacy. Inthe phage-treated group, the cure rate was 3 of 18 quarters (16.7%); noneof the saline-treated quarters were cured. The difference in cure rates wasnot statistically significant. Intramammary infusion of phage in non-infectedcows provoked a large increase in milk somatic cell counts, a responsethat was not observed in phage-treated SA-infected cows. The declineof phage concentrations in milk overtime suggested that the mammarygland was able to inactivate and/or degrade phage particles58Network analysis of Danish cattle industry trade patterns as anevaluation of risk potential for disease spreadCorresponding AuthorBigras-Poulin, M.Université de MontréalCollaboratorsThompson, R.A.Université de MontréalChriel, M.Université de MontréalMortensen, S.Université de MontréalGreiner, M.Université de MontréalPreventive Veterinary Medicine (2006) Vol. 76 p. 11-39.This paper describes the construction and analysis of a network of cattlepremises in Denmark. A premise is defined as a farm, an abattoir or a market.The objective was to characterize cattle movements between premisesas an aid to understanding potential disease transmission through animalcontact during movement between premises. A path for potential transferof pathogens is created when cattle move from premise to premise. Atotal of 29,999 premises were included in the network model with 130,265transfers between those premises in a 6-month period. Although networkanalysis could also be used to analyze within-premise (i.e., herd) diseasetransmission, this was not attempted in this study.94 Highlights in Canadian Dairy Cattle Research - 2007