title: Reisolation of Staphylococcus aureus from bovine milk following experimental inoculation is influenced by fat percentage and specific immunoglobulin G1 titer in milk.
abstract: The associations of management parameters, herd characteristics, and individual cow factors with bovine mastitis have been subject of many studies. The present study aimed to evaluate the association between milk composition parameters, including fat, protein, lactose, urea, and specific immunoglobulin levels, at the time of experimental bacterial inoculation of the mammary gland and subsequent shedding dynamics of Staphylococcus aureus. Sixty-eight cows were experimentally infected with S. aureus and closely monitored for 3 wk. Mixed model analyses were used to determine the influence of management and herd characteristics (farm and experimental group), individual cow factors (days in milk, milk yield, and quarter position), and a challenge-related parameter (inoculation dose) in combination with either the milk components fat, protein, lactose and urea, or the S. aureus-specific antibody isotype titers at the time of bacterial inoculation, on the number of S. aureus reisolated from milk after inoculation. A positive association was observed between the milk fat percentage and the number of S. aureus reisolated from quarter milk, and a negative relationship between the S. aureus-specific IgG1 titer in milk and the number of S. aureus. These findings should be considered in the development of a vaccine against S. aureus-induced bovine mastitis.
authors.affiliation: Ruminants Research and Development, MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, the Netherlands; Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, the Netherlands. Electronic address: eveline.boerhout@merck.com.
authors.forename: E M
authors.initials: EM
authors.lastname: Boerhout
authors.affiliation: Department of Bacteriology and TSE, Central Veterinary Institute part of Wageningen UR, Edelhertweg 15, PO Box 65, 8200 AB Lelystad, the Netherlands; Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors.forename: A P
authors.initials: AP
authors.lastname: Koets
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors.forename: J C M
authors.initials: JCM
authors.lastname: Vernooij
authors.affiliation: Ruminants Research and Development, MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, the Netherlands.
authors.forename: T G T
authors.initials: TGT
authors.lastname: Mols-Vorstermans
authors.affiliation: Ruminants Research and Development, MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, the Netherlands.
authors.forename: P J M
authors.initials: PJM
authors.lastname: Nuijten
authors.affiliation: Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL Utrecht, the Netherlands; Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa.
authors.forename: V P M G
authors.initials: VPMG
authors.lastname: Rutten
authors.affiliation: Discovery and Technology, MSD Animal Health, Wim de Körverstraat 35, 5830 AA Boxmeer, the Netherlands.
authors.forename: J J E
authors.initials: JJE
authors.lastname: Bijlsma
authors.affiliation: Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 7, 3584 CL Utrecht, the Netherlands.
authors.forename: S W F
authors.initials: SWF
authors.lastname: Eisenberg
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology; D008892:Milk / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000662:veterinary; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014611:Vaccination / Q000662:veterinary
keywords: Staphylococcus aureus; bovine mastitis; milk fat percentage; specific immunoglobulin G(1) titer