Genomic dynamics of antimicrobial resistance in canine and human derived Staphylococcus pseudintermedius

Summary

Staphylococcus pseudintermedius is a bacterium found on the skin and mucous membranes of healthy dogs. Generally, the bacteria is harmless, but the bacteria can also cause infections, such as ear and skin infections. Occasionally, infections with Staphylococcus pseudintermedius occur in humans. We compared Staphylococcus pseudintermedius bacteria originating from infections in dogs with Staphylococcus pseudintermedius bacteria originating from infections in humans. This comparison showed no difference between S. pseudintermedius bacteria from dogs and humans, thereby confirming our suspicion that the Staphylococcus pseudintermedius bacteria pass from the dog to its owner through intensive contact between them.

Infections caused by Staphylococcus pseudintermedius can usually be treated effectively with antibiotics, but Staphylococcus pseudintermedius can become resistant to an antibiotic. If so, the Staphylococcus pseudintermedius bacterium is no longer sensitive to the antibiotic and an infection is difficult to treat. In our research, we looked at the best way to measure resistance in Staphylococcus pseudintermedius bacteria in the laboratory. In addition, we investigated how Staphylococcus pseudintermedius becomes resistant to antibiotics. We showed that Staphylococcus pseudintermedius becomes resistant by picking up pieces of DNA from nearby bacteria. Staphylococcus pseudintermedius can even pick up multiple different pieces of DNA and thus become multi-resistant. This means that the bacterium is insensitive to a large number of antibiotics, which makes treatment even more difficult. That is not just unpleasant for the dog with an infection caused by a multi-resistant Staphylococcus pseudintermedius, but may also pose a risk for its owner.