We are searching data for your request:
Upon completion, a link will appear to access the found materials.
MRSA bacteria are increasingly transmitted from cattle
Cattle appear to be carriers of resistant MRSA bacteria. Genetic analyzes show that the pathogens have affected not only humans but also farm animals for thousands of years - and they keep jumping back and forth between different hosts. The host changes enable the bacteria to develop new antibiotic resistance through genetic changes. The results are particularly difficult to kill "super germs".
Many bacterial pathogens can no longer be controlled by antibiotics - they have built up resistance to them. Among the antibiotic-resistant bacteria, methicillin-resistant Staphylococcus aureus, or MRSA for short, is particularly feared. The bacterium is primarily known as a hospital germ. "It is spreading to clinics around the world," says Jukka Corander from the University of Helsinki. The pathogen can also appear in everyday life, theoretically nest in every household and also affect our useful and domestic animals. The scientists have published their results in the journal "Nature Ecology & Evolution".
Man as the original host
Despite its danger, little is known about the development and further development of the MRSA pathogen. To gain more fundamental insights, Corander and his colleagues have now examined numerous MRSA samples from humans and animals. They searched for DNA changes in the genome of the bacteria that indicate an adaptation to new hosts.
The result: Originally, the MRSA bacterium probably only affected us humans. According to genetic analyzes, the germ only acquired the ability to nest in other species after the so-called Neolithic Revolution - when humans began to domesticate animals and keep them in large herds on farms.
Cows as the main source
From this moment on, certain strains of pathogens have repeatedly changed hosts, according to the scientists. According to this, the bacteria regularly jump from farm animals to humans and vice versa. Such host changes are often accompanied by genetic mutations that make it easier for the bacteria to survive in the new environment in the long term - bacterial evolution!
Among other things, the pathogens can also become resistant to antibiotics - and ultimately become multi-resistant “super germs”. Cows are obviously a particular danger: According to the analyzes, they are an important pathogen reservoir and the main source of multi-resistant Staphyloccocus strains that trigger dangerous MRSA infections in humans.
"This observation makes it clear how important it is to carry out comprehensive monitoring in order to identify strains that may trigger epidemics at an early stage," says Corander. He and his colleagues hope that their research will help to minimize the risk of new MRSA strains migrating from animals to the human population. (fs)