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The MRSA staphylococcus is a pathogen called superbugs, they are resistant to antibiotics and can cause serious infections. MRSA bacteria have spread in hospitals across the globe. Researchers sequenced whole genomes of the superbugs from a large sample from different animals as well as humans, and were able to study the DNA changes that helped the bacteria to adapt to new host organisms during thousands of years.
Based on genome analysis, humans were most probably the original hosts to these superbugs, and judging from DNA changes, the ability to colonise domestic animals appeared in an age when the first animals were domesticated to become livestock on farms.
The research team discovered that cows are the source for strains of staphylococcus that are causing MRSA infections in humans around the world. These observations give emphasis to the importance of detailed epidemiological monitoring, so that strains with the potential to cause epidemics can be discovered early.
Detailed genomic analyses reveal that, when the bacteria move from one host species to another, it hijacks new genes to help it adapt and stay alive in the long term. In some cases, these genes give the bacteria resistance towards commonly used antibiotics.