title: Field trials of a vaccine against bovine mastitis. 2. Evaluation in two commercial dairy herds.
abstract: A vaccine against bovine mastitis was developed. The vaccine was based on inactivated, highly encapsulated Staphylococcus aureus cells; a crude extract of Staph. aureus exopolysaccharides; and inactivated unencapsulated Staph. aureus and Streptococcus spp. cells. In this study, the vaccine was evaluated in 164 cows from two commercial dairies (A and B) during a 4-mo period. Two doses of the vaccine were administered subcutaneously to 82 cows in the brachiocephalicus muscle of the neck within a 4-wk interval. The results of this trial revealed significantly fewer intramammary infections caused by Staph. aureus at various levels of severity (clinical, subclinical, and latent) in cows that were vaccinated. The odds ratios of all types of intrammammary infections caused by Staph. aureus for dairies A and B, which were determined by a logistic model, were 1.84 and 1.89, respectively, for quarters of vaccinated cows and quarters of control cows. The colony counts for Staph. aureus in milk from infected quarters of vaccinated cows were significantly lower than those in milk from infected quarters of control cows. Also, the somatic cell counts per milliliter in milk from vaccinated cows were significantly decreased when the initial somatic cell count was < 500,000 cells/ml at the start of the trial. The vaccine had no observable effect on fat production in milk or on streptococcal infections.
authors.affiliation: Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Calzolari
authors.forename: J A
authors.initials: JA
authors.lastname: Giraudo
authors.forename: H
authors.initials: H
authors.lastname: Rampone
authors.forename: L
authors.initials: L
authors.lastname: Odierno
authors.forename: A T
authors.initials: AT
authors.lastname: Giraudo
authors.forename: C
authors.initials: C
authors.lastname: Frigerio
authors.forename: S
authors.initials: S
authors.lastname: Bettera
authors.forename: C
authors.initials: C
authors.lastname: Raspanti
authors.forename: J
authors.initials: J
authors.lastname: Hernández
authors.forename: M
authors.initials: M
authors.lastname: Wehbe
authors.forename: M
authors.initials: M
authors.lastname: Mattea
authors.forename: M
authors.initials: M
authors.lastname: Ferrari
authors.forename: A
authors.initials: A
authors.lastname: Larriestra
authors.forename: R
authors.initials: R
authors.lastname: Nagel
mesh_terms: D000818:Animals; D001118:Argentina; D001428:Bacterial Vaccines; D002417:Cattle; D002452:Cell Count; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology / Q000517:prevention & control*; D008892:Milk / Q000166:cytology; D016017:Odds Ratio; D013203:Staphylococcal Infections / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000276:immunology; D013290:Streptococcal Infections / Q000517:prevention & control; D013291:Streptococcus / Q000276:immunology
chemical_list: D001428:Bacterial Vaccines