We examined the dose-dependent effects of feeding lactating dairy cows a standard diet supplemented with monensin at 175, 368, or 518 mg cow^-1 day^-1 on the rumen microbiota. For each dosage, 3 animals were randomly assigned into groups and fed the same basal total mixed ration diet supplemented with monensin, at the respective dose. After 20 days, rumen samples were taken and the effect on the microbiota was examined by 16S rRNA gene sequence analysis and qPCR. At the lowest dose no significant change in 16S rRNA gene sequences associated with any bacterial phyla was observed; however, at the medium and high dosages, we observed significant reductions in sequences associated with gram-positive bacteria and significant increases in those associated with gram-negative bacteria that were dosage dependent. All dosages reduced the levels of sequences associated with methanogenic archaea in the rumen, with the medium dosage showing the largest decline. No significant difference was observed for the 18S rRNA gene sequences associated with protozoa in any of the libraries. Our results indicate that with this diet the medium dosage of monensin was most efficacious for the reduction in methanogenic archaea in the rumen of lactating dairy.

Soil and soil biodiversity play critical roles in Nature's Contributions to People (NCP) # 10, defined as Nature's ability to regulate direct detrimental effects on humans, and on human-important plants and animals, through the control or regulation of particular organisms considered to be harmful. We provide an overview of pathogens in soil, focusing on human and crop pathogens, and discuss general strategies, and examples, of how soils' extraordinarily diverse microbial communities regulate soil-borne pathogens. We review the ecological principles underpinning the regulation of soil pathogens, as well as relationships between pathogen suppression and soil health. Mechanisms and specific examples are presented of how soil and soil biota are involved in regulating pathogens of humans and plants. We evaluate how specific agricultural management practices can either promote or interfere with soil's ability to regulate pathogens. Finally, we conclude with how integrating soil, plant, animal and human health through a 'One Health' framework could lead to more integrated, efficient and multifunctional strategies for regulating detrimental organisms and processes. This article is part of the theme issue 'The role of soils in delivering Nature's Contributions to People'.

Prions, or infectious proteins, cause a class of uniformly fatal neurodegenerative diseases. Prions are composed solely of an aberrantly folded isoform (PrP(Sc)) of a normal cellular protein (PrP(C)). Shared sequence identity of PrP(Sc) with PrP(C) has limited the detection sensitivity of immunochemical assays, as antibodies specific for the disease-causing PrP(Sc) isoform have not been developed. Here we report the generation of three new monoclonal antibodies (MAbs) to PrP, which were isolated following immunization of Prnp(0/0) Balb/cJ mice with highly purified PrP(Sc) isolated from brain lipid rafts. Epitope mapping using synthetic PrP peptides revealed that the three MAbs bind different epitopes of PrP. The DRM1-31 MAb has a conformational epitope at the proposed binding site for the putative prion conversion co-factor "protein X." The DRM1-60 MAb binds a single linear epitope localized to the β2-α2 loop region of PrP, whereas DRM2-118 binds an epitope that includes sequences within the octarepeat region and near the site of N-terminal truncation of PrP(Sc) by proteinase K. Our novel anti-PrP MAbs with defined PrP epitopes may be useful in deciphering the conformational conversion of PrP(C) into PrP(Sc).

Wild birds pose unique food-safety risks to agriculture as they may carry multiple zoonotic pathogens, are difficult to exclude, and most are federally protected. As a result, the fresh produce industry regularly expresses concerns about these risks, and growers are sometimes instructed to not harvest crops around wild bird feces, potentially causing yield reductions and food waste. Farmers thus have financial incentives to reduce bird fecal contamination on their crops. However, existing bird deterrent methods can be expensive, have significant deleterious conservation implications, and/or are often ineffective. Thus, it is imperative to develop a holistic understanding of the true food-safety risks associated with wild bird communities and to inform growers and industry professionals about which birds, if any, represent substantive food safety concerns. Here, we evaluate the food-safety risks of wild birds, from the point of entering farms through harvest of the crop via three complementary approaches.

We present here the complete genome sequences of three Salmonella enterica subsp. enterica serovar Muenchen strains, LG24, LG25, and LG26. All three strains were isolated from almond drupes grown in an orchard in San Joaquin County, California, in 2016. These genomic sequences are nonidentical and will contribute to our understanding of S. enterica genomics.