Studies of bacteria linked to common infections in pet dogs are giving valuable insights that will help diagnosis and treatment.
Scientists have analysed and compared the DNA from samples of Staphylococcus coagulans bacteria taken from infected dogs, to better understand how the bugs spread and cause infection.
Insights offered by the research could help manage disease caused by the bacteria such as skin, ear or urinary infections in dogs, and occasional infections in people. It could also enable targeted treatment tailored to the bacteria present in an infection and so help to limit antimicrobial resistance.
Researchers at the Royal (Dick) School of Veterinary Studies carried out detailed DNA analysis on 25 newly acquired samples of S. coagulans bacteria taken from infected dogs, together with a further eight samples previously collected by the lab and eight samples in public databases.
The team derived the DNA sequence for each sample of bacteria, enabling them to identify small variations between different strains and to understand how these have evolved over time, building up a picture of the bacteria’s family tree.
Their findings will help vets and scientists pinpoint those strains that are closely related and are likely to be spreading, and in which part of the world they are likely to be found.
This insight can inform how to treat infections caused by the bacteria and limit the rise of antimicrobial resistance.
The findings also support the use of DNA analysis of bacteria in individual cases of infection, so that diagnosis and treatment can be guided by the type of bacteria present in any patient.
Researchers used their genetic insights to identify a suitable treatment for 10 of the bacteria strains. Their genes showed key characteristics common to some other Staphylococcus species, which are susceptible to treatment with a combination of penicillin and clavulanic acid.
When tested in the lab, subtypes with this genetic signature were found to respond to this same treatment.
All samples examined for the study are stored at the Royal (Dick) School of Veterinary Studies for further research, and the DNA sequence data generated in the study is freely available to scientists via online databases
Their research was published in the Journal of Medical Microbiology.
In a separate study, funded by PetSavers, a division of the BSAVA, the same team discovered two new species of Staphylococcus in swabs from healthy dogs.
Their discovery, published in the International Journal of Systematic and Evolutionary Microbiology, adds to the body of knowledge about the family of Staphylococcus bacteria, and will aid further research into how the various types cause disease and resist antimicrobial treatment.
Finding new species of this important family of bacteria adds to our knowledge base, while our DNA analysis of S. coagulans gives us high resolution insight into their family tree, which shows how the strains are spreading and the types of treatments we can use that will be effective without exacerbating the rise in antimicrobial resistance. These findings also support the use of genome analysis to identify the bacteria present in individual cases, enabling targeted treatment.
Dr Gavin Paterson, Senior Lecturer in Molecular and Applied Microbiology, Dick Vet and the Roslin Institute