Vet Chat


New technology aids antibiotic stewardship


Perhaps one of the greatest medical breakthroughs of our age was the discovery of penicillin by Alexander Flemming in 1928. New antibiotics were rapidly discovered which revolutionized the means by which infectious diseases were treated. Common human infections became easily curable and outbreaks of infectious disease were readily controlled. However, just a few years after the golden age of antibiotics, warning signs of developing resistance were observed. Just as Flemming had predicted, previously susceptible bacteria were evolving and mutating to develop resistance to antibiotics at an alarming speed. Although the magnitude of this problem is still unclear, it is proposed that abuse and misuse of antibiotics is largely responsible for the development of resistance. In less than 100 years after antibiotic discovery, we now face a grim scenario for the generation to come where most antimicrobials might no longer be effective. Human and veterinary medicine may once again enter an era where common bacterial infections could once again prove lethal.

Antibiotic usage in food animals improves more than just animal well-being but also has economic benefits for food animal producers along with a safer public health sector. Significant quantities of antibiotics are used in animal production industries and consequently the incidence of antibiotic resistance has increased.


Demonstration of evidence-based usage and commitment to ethical antibiotic stewardship is necessary to maintain safe and effective veterinary use of antibiotics, and to preserve public acceptance of this usage. However, bacterial resistance to antibiotics is not as clear cut as being “Resistant” or “Susceptible”. Most mechanisms of bacterial resistance depend on the concentration of the antibiotic present.

A new technology, developed by Bayer, which measures the minimum concentration of an antibiotic to inhibit bacterial growth, allows veterinarians to make informed decisions on the most effective treatments. Using this data, an “antibiogram” is developed for individual bacteria and compared over time to detect new levels of antibiotic resistance. The Dairy Antibiogram can be currently used for the common mastitis pathogens, Staphylococcus aureus and Streptococcus uberis, and a range of antibiotics are assessed. Dairy farmers, in conjunction with their veterinarians, now have a unique opportunity to build reliable susceptibility testing into their mastitis programs, and to use this data to guide responsible antibiotic use. A simple, single bulk milk sample is required to provide farm-level antibiograms which can quantify the current status of antibiotic susceptibility of S.aureus and S.uberis.


The Dairy Antibiogram:

Provides educated, evidence-based advice on the choice of mastitis treatment. Ensures effective use of antibiotics.
Monitors antibiotic resistance status at the herd-level. Provides good evidence of responsible use of antibiotics. Supports the dairy industry by contributing data to the national database and preserving the efficacy of mastitis treatments. Ensures continued public approval and access to antibiotics for therapy and animal welfare purposes. Develops a picture of the current state of antibiotic resistance, and monitors its change over time and in relation to usage practices. Upholds the reputation of the Australian dairy industry. 

Call the clinic to discuss how the Dairy Antibiogram can help your herd with one of our veterinarians.