European Mastitis Research Workers meet in Copenhagen

More than 35 researchers, mainly from Europe but also from the US and Australia and working in the field of mastitis and milk quality, gathered for what was another excellent meeting, hosted by Prof. Ilka Klaas, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. A number of presentations gave rise to interesting discussions.

Some highlights:

• In Finland, 78% of all dairy herds apply selective dry cow therapy whereas 13%, mostly milking cows with an automated milking system, are using blanket dry cow therapy (Maria Vilar, Finland).
• Carsten Kirkeby (Denmark) presented a new simulation model that simulates strain-specific transmission of mastitis pathogens within a dairy herd. The model can simulate both environmental and contagious pathogens. Furthermore, it can simulate opportunistic pathogens like Streptococcus agalactiae which show both environmental and contagious properties.
• In Sweden, a new project with the long-term aim to prevent udder health problems at calving in heifers has started recently (Persson Waller, Sweden).
• Antimicrobial peptides are highly abundant during clinical mastitis. They show increased inducibility after targeted immunomodulation and in vitro activity against major mastitis pathogens (Wolfram Petzel, Germany)
• Both statistical analyses of genomic content and a phylogenetic single-nucleotide polymorphism analysis showed that Danish Staphylococcus aureus isolates from bulk tank milk and clinical mastitis generally were of identical genetic background (Troels Ronco, Denmark).
• Francisco Malcata from the University of Glasgow (UK) proposed a strategy to reduce antimicrobial usage, combining on-farm culture, information from the host, pathogen and the herd for targeted treatment in bovine clinical mastitis.
• In Brazil, differences in the ability of bovine-associated staphylococcal species and strains to resist phagocytosis and bactericidal killing by blood and milk bovine neutrophils were present at both the species and ecological niche levels (Fernando Souza, Brazil).
• Staphylococcal supernatants of non-aureus staphylococcal (NAS) species isolated from milk and teat skin interfered with the agr quorum sensing system of Staphylococcus aureus. The NAS isolates showed three patterns: (a) downregulation such as Staphylococcus chromogenes (milk), (b) no effect such as Staphylococcus sciuri (teat), and (c) variant effects such as Staphylococcus epidermidis (milk and teat). The pattern of cross talk between NAS species and S. aureus virulence gene expression varied according to the involved NAS species, habitat type, and herd factors (Yasser Mahmmod, Denmark).
• Milk, teat canal and teat skin are the sources of contamination of milking machines with Staphylococcus aureus. Back-flushing of liners between cows has an effect on the magnitude of contamination rather than on the prevalence of contamination, which was 25% of the studied liners after milking in two herds (Mari Hovinen, Finland).

Photo: Ilka Klaas