title: A longitudinal study on transmission of Staphylococcus aureus genotype B in Swiss communal dairy herds.
abstract: Staphylococcus aureus is a common mastitis causing pathogen of dairy cattle. Several S. aureus genotypes exist, of which genotype B (GTB) is highly prevalent in Swiss dairy herds. Dairy farming in mountainous regions of Switzerland is characterised by the movement of dairy cattle to communal pasture-based operations at higher altitudes. Cows from different herds of origin share pastures and milking equipment for a period of 2 to 3 months during summer. The aim of this longitudinal observational study was to quantify transmission of S. aureus GTB in communal dairy operations. Cows (n=551) belonging to 7 communal operations were sampled at the beginning and end of the communal period. Transmission parameter β was estimated using a Susceptible-Infectious-Susceptible (SIS) model. The basic reproduction ratio R0was subsequently derived using previously published information about the duration of infection. Mean transmission parameter β was estimated to be 0.0232 (95% CI: 0.0197-0.0274). R0was 2.6 (95% CI: 2.2-3.0), indicating that S. aureus GTB is capable of causing major outbreaks in Swiss communal dairy operations. This study emphasized the contagious behaviour of S. aureus GTB. Mastitis management in communal dairy operations should be optimized to reduce S. aureus GTB transmission between cows and back to their herds of origin.
authors.affiliation: Veterinary Public Health Institute, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 151, 3097 Liebefeld, Switzerland. Electronic address: bartvdborne@gmail.com.
authors.forename: Bart H P
authors.initials: BHP
authors.lastname: van den Borne
authors.affiliation: Agroscope, Institute for Food Sciences, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
authors.forename: Hans U
authors.initials: HU
authors.lastname: Graber
authors.affiliation: Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, 3012 Bern, Switzerland.
authors.forename: Verena
authors.initials: V
authors.lastname: Voelk
authors.affiliation: Agroscope, Institute for Food Sciences, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Sartori
authors.affiliation: Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, 3012 Bern, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Steiner
authors.affiliation: Institute of Agricultural Sciences (IAS), ETH Zurich, Universitaetsstrasse 2, 8092 Zurich, Switzerland.
authors.forename: M Christina
authors.initials: MC
authors.lastname: Haerdi-Landerer
authors.affiliation: Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, 3012 Bern, Switzerland.
authors.forename: Michèle
authors.initials: M
authors.lastname: Bodmer
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000635:transmission*; D005260:Female; D005838:Genotype; D008137:Longitudinal Studies; D013203:Staphylococcal Infections / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000235:genetics / Q000502:physiology*; D013557:Switzerland
keywords: Dairy cattle; Intramammary infection; Mastitis; Reproduction ratio; Staphylococcus aureus; Transmission parameter