title: Intramammary infections with the contagious Staphylococcus aureus genotype B in Swiss dairy cows are associated with low prevalence of coagulase-negative staphylococci and Streptococcus spp.
abstract: The association between the contagious Staphylococcus aureus genotype B (GTB) and the presence of coagulase-negative staphylococci (CNS) and Streptococcus spp. (non-agalactiae streptococci), was investigated, and the identification of problem herds without genotyping was evaluated. Milk samples from 10 herds with Staph. aureus GTB herd problems (PH cases) were compared with samples from 19 herds with at least one Staph. aureus isolate of non-B genotype (CH cases). All samples were bacteriologically analysed and Staph. aureus genotyping carried out using a ribosomal spacer-PCR. Cow and quarter prevalences of Staph. aureus, CNS and Streptococcus spp. differed significantly between PH and CH groups. PH cases were highly associated with decreased cow prevalences of CNS and Streptococcus spp. These altered prevalences also contributed significantly to the identification of problem herds without resorting to genotyping. Common herd-level risk factors did not explain the difference between the prevalences in PH and CH cases.
authors.affiliation: Clinic for Ruminants, Department of Clinical Veterinary Medicine, University of Berne, Bremgartenstrasse 109a, PO Box 8466, 3001 Berne, Switzerland. astrid.michel@knp.unibe.ch
authors.forename: Astrid
authors.initials: A
authors.lastname: Michel
authors.forename: Claudia
authors.initials: C
authors.lastname: Syring
authors.forename: Adrian
authors.initials: A
authors.lastname: Steiner
authors.forename: Hans U
authors.initials: HU
authors.lastname: Graber
mesh_terms: D000818:Animals; D002417:Cattle; D003030:Coagulase; D003352:Corynebacterium / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D008414:Mastitis, Bovine / Q000382:microbiology*; D008892:Milk / Q000382:microbiology; D015995:Prevalence; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013210:Staphylococcus / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000235:genetics*; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary; D013291:Streptococcus / Q000302:isolation & purification; D013557:Switzerland / Q000453:epidemiology
chemical_list: D003030:Coagulase