Antibiotic resistance genes (ARGs) are a relatively new type of pollutant. The rise in antibiotic resistance observed recently is closely correlated with the uncontrolled and widespread use of antibiotics in agriculture and the treatment of humans and animals. Resistant bacteria have been identified in soil, animal feces, animal housing (e.g., pens, barns, or pastures), the areas around farms, manure storage facilities, and the guts of farm animals. The selection pressure caused by the irrational use of antibiotics in animal production sectors not only promotes the survival of existing antibiotic-resistant bacteria but also the development of new resistant forms. One of the most critical hot-spots related to the development and dissemination of ARGs is livestock and poultry production. Manure is widely used as a fertilizer thanks to its rich nutrient and organic matter content. However, research indicates that its application may pose a severe threat to human and animal health by facilitating the dissemination of ARGs to arable soil and edible crops. This review examines the pathogens, potentially pathogenic microorganisms and ARGs which may be found in animal manure, and evaluates their effect on human health through their exposure to soil and plant resistomes. It takes a broader view than previous studies of this topic, discussing recent data on antibiotic use in farm animals and the effect of these practices on the composition of animal manure; it also examines how fertilization with animal manure may alter soil and crop microbiomes, and proposes the drivers of such changes and their consequences for human health.
The application of chicken waste to farmland could be detrimental to public health. It may contribute to the dissemination of antibiotic-resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) from feces and their subsequent entry into the food chain. The present study analyzes the metagenome and resistome of chicken manure and litter obtained from a commercial chicken farm in Poland. ARB were isolated, identified, and screened for antibiogram fingerprints using standard microbiological and molecular methods. The physicochemical properties of the chicken waste were also determined. ARGs, integrons, and mobile genetic elements (MGE) in chicken waste were analyzed using high-throughput SmartChip qPCR. The results confirm the presence of many ARGs, probably located in MGE, which can be transferred to other bacteria. Potentially pathogenic or opportunistic microorganisms and phytopathogens were isolated. More than 50% of the isolated strains were classified as being multi-drug resistant, and the remainder were resistant to at least one antibiotic class; these pose a real risk of entering the groundwater and contaminating the surrounding environment. Our results indicate that while chicken manure can be sufficient sources of the nutrients essential for plant growth, its microbiological aspects make this material highly dangerous to the environment.
One of the most important public health challenges facing the world today is that posed by antibiotic resistance. Many pathogenic antibiotic-resistant bacteria and their antibiotic resistance genes, usually located on mobile genetic elements, are frequently present in the faeces of farm animals. To prevent the possibility of antimicrobial resistance transfer to the environment, these faeces should undergo treatment before being used as natural fertilizer. The two strategies for processing pig manure proposed in this study, viz. storage (most commonly used for livestock manure today) and composting, are cheap and do not require special tools or technologies. The present study examines the changes in the physicochemical properties of treated manure, in the microbiome, through metagenomic sequencing, and in the resistome, using the SmartChip Real-time PCR system compared to raw manure. This is the first such comprehensive analysis performed on the same batch of manure. Our results suggest that while none of the processes completely eliminates the environmental risk, composting results in a faster and more pronounced reduction of mobile genetic elements harbouring antibiotic resistance genes, including those responsible for multi-drug resistance. The physicochemical parameters of the treated manure are comparable after both processes; however, composting resulted in significantly higher organic matter. Overall, it appears that the composting process can be an efficient strategy for mitigating the spread of antibiotic resistance in the environment and reducing the risk of its transfer to agricultural crops and hence, the food chain. It also provides the organic matter necessary for humus formation, and increases the sorption properties of the soil and the micro and macro elements necessary for plant growth, which in turn translates into increased soil productivity.HighlightsThe changes in microbial population composition correlate with changes in specific antibiotic-resistance genes and mobile genetic elements in the studied populations.Positive correlations have been demonstrated between microbial phyla and genes coding the multi-drug resistance mechanismCo-occurrence networks showed positive correlations between antibiotic-resistance genes and mobile genetic elementsThe composting strategy was most efficient at reducing microbial loads, antibiotic resistance genes and mobile genetic elements.Composted manure can be part of a natural, safe soil fertilization strategy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.