The World Health Organization has identified antibiotic resistance as a serious threat to human health across the world. Enrofloxacin belongs to the class of fluoroquinolone antibiotics that have been intensively used in agriculture. In the environment, enrofloxacin can undergo degradations by different processes, but it is not sensitive to hydrolysis. Despite these degradation mechanisms, environmental half life time of enrofloxacin is very long. The effect of enrofloxacin on the function and structure of soil microbiome in agroecosystems of medicinal plants was evaluated. Soil microbiome and resistome of medicinal plants are directly or indirectly involved in the production of bioactive phytochemicals. In soils with different concentrations of enrofloxacin were planted: Lactuca sativa var. crispa, Anethum graveolens, Thymus serpillum, Mentha piperita, Calendula officinalis. The soil of agroecosystem with a high concentration of antibiotic was characterized by a low content of nitrogen-fixing microorganisms and a high number of oligotrophic and spore-forming microbiota. In Vitro experiment were isolated 5 bacteria absolutely resistant to all tested antibiotics. Among AR microorganisms were anaerobic bacteria: Clostridium difficile, Clostridium perfringens and aerobic bacteria: Enterococcus faecalis, Yersinia enterocolitica, Enterobacter cloacae. In experiments In Vivo from the soil, were isolated 7 bacteria resistant to all tested antibiotics. They were representatives of aerobic microbiota: Bacillus licheniformis, Serratia fonticola, Hafnia alvei, Bacillus cereus, Pantoea agglomerans, Bacillus megaterium and anaerobic bacteria - Clostridium difficile. In natural conditions, from the soil of agroecosystems were isolated mostly bacteria of the genus Bacillus. Majority of them are the foodborne pathogens. Environmental contamination by antibiotics cause negative changes in soil microbiome and is one of the important factors in the formation of soil resistome.
Audience Take Away Notes:
- Modern agroecosystems of medicinal plants are the source of spreading of pathogenic and opportunistic microorganisms with multiple antibiotic resistances and endangering human health.
- Management of soil microbiota is vitally important for safeguarding public health.
- The soil microbiome plays an important role in the development and spread of antibiotic resistance in humans.
- The risk to antibiotic resistance exposure via products including medicinal plants should be best managed. It's necessary to implement tools for protection of bioproduction from contamination by pathogenic microorganisms.
- Monitoring antibiotic resistance in ecosystems is an additional tool for controlling and managing biosecurity.