Soil microbes discovered with antibiotic-resistant hospital germs
Antibiotic resistance is mostly associated with hospital germs. They pose a high health risk for patients with bacterial infections. If no antibiotic is effective, bacteria can spread in the body and, in the worst case, cause the patient to die. An international team of researchers has now discovered antibiotic resistance in soil microbes. The resistance-mediating genes presumably get into the soil via manure, manure and waste water and spread ever further from there.
Genes that impart resistance to antibiotics end up in the soil via waste water, liquid manure and manure. For medical care or in animal husbandry - antibiotics are used too frequently and too carelessly. Experts have long agreed on this. The result of the mass supply are antibiotic-resistant germs, bacteria with which penicillin and Co. are no longer effective. So-called multi-resistant germs are a major problem, especially in hospitals.
Everyone can transmit (multi-) resistant germs, even if the antibiotic treatment was some time ago. In healthy people, the pathogens usually have no serious health consequences. However, if the germs get into the body of a seriously ill person who has a weak immune system, such as patients in an intensive care unit, they can cause serious damage and even lead to the patient's death. The typical consequences of an infection with multi-resistant germs include severe inflammation of surgical wounds, blood poisoning and pneumonia. Special hygiene regulations and threads are intended to help prevent such germs from spreading in hospitals. Nevertheless, they get into the environment via residues in wastewater and pass on their resistance to other bacteria via certain genes.
Antibiotic-resistant soil microbes have now been discovered. As reported by an international research group in the current issue of the scientific journal "Science", "it was the first time that evidence was found of a transfer of resistance-mediating genes between pathogenic germs and harmless soil microbes".
Pathogens have genes in direct contact with soil microbes Kevin Forsberg of the Washington University School of Medicine and his colleagues found that harmless soil bacteria could contribute to the spread of antibiotic resistance. When analyzing soil samples from fields, among other things, the scientists discovered microbes that were resistant to five common classes of antibiotics. As the researchers report, the resistance-mediating genes of the harmless bacteria correspond to those of germs that can trigger serious infections and are difficult to combat. This suggests that the pathogens would have transmitted their genes in direct contact with the soil microbes. The microbes could pass on their resistance to other germs, which could then also develop antibiotic resistance, the scientists write.
The resistant germs presumably entered the fields via manure and manure from farm animals treated with antibiotics. In addition, "residues in wastewater could be responsible for the spread in the environment," the researchers speculate. For some time it has been suspected that harmless germs are also significantly involved in the transmission and spread of antibiotic resistance. "Now we know that this could at least be the case with the floor," write Forsberg and his colleagues.
Multi-resistant soil microbes also discovered The scientists analyzed soil samples from eleven different locations in the USA. A total of 95 bacterial cultures were isolated and examined for their susceptibility to 18 different antibiotics. The resistance genes of the microbes were also examined closely.
The researchers identified seven antibiotic-resistant genes in the soil bacteria that were identical to those of resistant strains of hospital germs. This indicates that the transfer of resistance has only recently occurred, the scientists report. The resistance genes protect the bacteria against five common classes of antibiotics, including beta-lactams, aminoglycosides, amphenicols, sulfonamides and tetracyclines. “These genes therefore encompass all major types and strategies of antibiotic resistance,” the researchers explain. In two of the types of bacteria from arable soils, six genes were discovered at once. This makes them multi-resistant. Only one or a few genes were found in other bacteria. "This is the first evidence of such a gene transfer between pathogenic germs and harmless soil microbes," write the scientists. The soil is therefore a crucial reservoir for antibiotic resistance, which can be transmitted both from disease-causing germs to the soil microbes and vice versa. However, the exact processes of the exchange are not yet known and must now be examined. (ag)
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