Soil type and moisture content alter soil microbial responses to antibiotic and manure exposure

Antibiotic usage has continuously increased since their discovery and the resulting microbial resistance to antibiotics has been a growing concern. Livestock administered antibiotics have the potential to spread antibiotic compounds, resistant bacteria, and antibiotic resistance genes (ARGs) to soil through manure. Although environmental transmission of antibiotic resistance is a major human health concern, few studies have looked at interactive effects of environmental conditions and antibiotics from livestock on soil microbial communities. We examined the effects of additions of manure from cattle under different antibiotic treatments on microbial community structure in varying soil types and moisture contents. Manure was added biweekly to soil microcosms. Soil samples were collected after 10 weeks of manure applications to examine impacts on bacterial and fungal communities.