Changing trends in mastitis

Abstract

The global dairy industry, the predominant pathogens causing mastitis, our understanding of mastitis pathogens and the host response to intramammary infection are changing rapidly. This paper aims to discuss changes in each of these aspects. Globalisation, energy demands, human population growth and climate change all affect the dairy industry. In many western countries, control programs for contagious mastitis have been in place for decades, resulting in a decrease in occurrence of Streptococcus agalactiae and Staphylococcus aureus mastitis and an increase in the relative impact of Streptococcus uberis and Escherichia coli mastitis. In some countries, Klebsiella spp. or Streptococcus dysgalactiae are appearing as important causes of mastitis. Differences between countries in legislation, veterinary and laboratory services and farmers' management practices affect the distribution and impact of mastitis pathogens. For pathogens that have traditionally been categorised as contagious, strain adaptation to human and bovine hosts has been recognised. For pathogens that are often categorised as environmental, strains causing transient and chronic infections are distinguished. The genetic basis underlying host adaptation and mechanisms of infection is being unravelled. Genomic information on pathogens and their hosts and improved knowledge of the host's innate and acquired immune responses to intramammary infections provide opportunities to expand our understanding of bovine mastitis. These developments will undoubtedly contribute to novel approaches to mastitis diagnostics and control.

Clustering of Staphylococcus aureus bovine mastitis strains from regions of Central-Eastern Poland based on their biochemical and genetic characteristics

“…This is mainly due to the difficulties in routine diagnostics, persistence of staphylococcal infections and abundance of S. aureus in the environment. The bacteria can be found on the skin of bovine and non-bovine animals, on the skin of staff, on milking equipment, flies, and throughout the barn or farm area (Zadoks and Fitzpatrick 2009). It is therefore important to determine the source and the nature of the mastitis infection, which may demonstrate a clonal, subclonal or ecological character.…”

“…Mastitis, inflammation of the mammary gland, is one of the most common infections caused by staphylococci among livestock, and is associated with significant economic losses in farming and the dairy industry. Among the many species of bacteria that cause mastitis in cattle, Staphylococcus aureus is mentioned as one of the most contagious and common etiologic factors of this disease (Zadoks and Fitzpatrick 2009, Le Marechal et al 2011, Peton and Le Loir 2013. Staphylococci are isolated from the mastitic milk of animals suffering from an acute inflammation of the udder, but more frequently from cows that exhibit or do not exhibit any clinical manifestation of the disease (subclinical mastitis).…”

Pathogen profile of clinical mastitis in Irish milk‐recording herds reveals a complex aetiology

“…International studies have identified large variation in the pathogens deemed to be the predominant cause of mastitis depending on geographical location, production system and local mastitis control programmes (Zadoks and Fitzpatrick 2009). There is a dearth of information on the aetiology of mastitis on Irish farms.…”

A structural equation model to evaluate direct and indirect factors associated with a latent measure of mastitis in Belgian dairy herds

“…Statements about the associations between MAM and risk factors are therefore more comprehensive and less specific than those made for each individual mastitis indicator. The methodology is not adequate to find management strategies effective against particular mammary pathogens but it is suited to studies, like ours, with the objective of identifying factors influencing herd mastitis in a global manner, given that trends in mastitis have changed over the last 50 years and that different mastitis pathogens are predominant in different herds, regions and countries (Zadoks and Fitzpatrick, 2009). …”