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Abstract Diverse patterns of climate and edaphic factors challenge detection of soil property change in the US Great Plains. Because detectable soil change can take decades, insights into the trajectory of soil properties frequently require long‐term site monitoring and, where available, associated soil archives to enable comparisons with initial or baseline states. Unfortunately, few multi‐decadal soil change investigations have been conducted in this region. Here, we document effects of dryland cropping on a suite of soil properties by comparing matched historic (1947) and contemporary (2018) soil samples from the Haas Soil Archive at three sites in the US Great Plains: Moccasin, MT, Akron, CO, and Big Spring, TX. Current analytical methods were used to provide insight into changes in soil texture, pH, carbon, and micronutrients at 0‐ to 15.2‐cm and 15.2‐ to 30.5‐cm depths. Changes in direction and magnitude of soil properties over 71 years were site specific. Changes in textural class occurred at all sites, with Moccasin and Akron transitioning from loam to clay loam and Big Spring from sandy clay loam to sandy loam. The soil pH reaction class changed from slightly alkaline to moderately acid at Akron and slightly alkaline to moderately alkaline at Big Spring. At 0–15.2 cm, soil organic carbon decreased by 15% and 36% at Moccasin and Big Spring, respectively, but increased by 15% at Akron. Soil micronutrients generally declined at all sites. Weather‐related variables derived from air temperature and precipitation records were not correlated with soil change. Inferred factors contributing to soil change included on‐site management, inherent soil features, weather metrics not evaluated, or a combination thereof.

Abstract Cyclosporine is a potent immunosuppressive agent used to treat immune‐mediated disorders in dogs. Secondary infections sometimes necessitate withdrawal of cyclosporine, but it is not known how long it takes for the immune system to recover after cessation of cyclosporine. Our goal was to utilize a validated RT‐qPCR assay in dogs to assess recovery time of the T‐cell cytokines IL‐2 and IFN‐γ after discontinuation of cyclosporine. Six healthy dogs were given oral cyclosporine (10 mg/kg every 12 hr) for 1 week, with samples collected for measurement of cytokine gene expression prior to treatment, and on the last day of therapy. Cyclosporine was then discontinued, and samples were collected daily for an additional 7 days. Results revealed that there was a significant difference in cytokine expression when comparing pre‐treatment and immediate post‐treatment values, corresponding to marked suppression of T‐cell function. There was no significant difference between pre‐treatment values for either cytokine when compared with any day during the recovery period. Cytokine expression, evaluated as a percentage of pre‐treatment baseline samples, demonstrated progressing return of T‐cell function after drug cessation, with full recovery seen in all dogs by Day 4 of the recovery period.

Antimicrobial resistance associated with the spread of plasmid-encoded extended-spectrum β-lactamase (ESBL) genes conferring resistance to third generation cephalosporins is increasing worldwide. However, data on the population of ESBL producing E. coli in different animal sources and their antimicrobial characteristics are limited. The purpose of this study was to investigate potential reservoirs of ESBL-encoded genes in E. coli isolated from swine, beef, dairy, and poultry collected from different regions of the United States using whole-genome sequencing (WGS). Three hundred isolates were typed into different phylogroups, characterized by BOX AIR-1 PCR and tested for resistance to antimicrobials. Of the 300 isolates, 59.7% were resistant to sulfisoxazole, 49.3% to tetracycline, 32.3% to cephalothin, 22.3% to ampicillin, 20% to streptomycin, 16% to ticarcillin; resistance to the remaining 12 antimicrobials was less than 10%. Phylogroups A and B1 were most prevalent with A (n = 92, 30%) and B1 (87 = 29%). A total of nine E. coli isolates were confirmed as ESBL producers by double-disk synergy testing and multidrug resistant (MDR) to at least three antimicrobial drug classes. Using WGS, significantly higher numbers of ESBL-E. coli were detected in swine and dairy manure than from any other animal sources, suggesting that these may be the primary animal sources for ESBL producing E. coli. These isolates carry plasmids, such as IncFIA(B), IncFII, IncX1, IncX4, IncQ1, CollRNAI, Col440I, and acquired ARGs aph(6)-Id, aph(3″)-Ib, aadA5, aph(3′)-Ia, blaCTX-M-15, blaTEM-1B, mphA, ermB, catA1, sul1, sul2, tetB, dfrA17. One of the E. coli isolates from swine with ST 410 was resistant to nine antibiotics and carried more than 28 virulence factors, and this ST has been shown to belong to an international high-risk clone. Our data suggests that ESBL producing E. coli are widely distributed in different animal sources, but swine and dairy cattle may be their main reservoir.

In agricultural systems, interactions between plants and microorganisms are important to maintaining production and profitability. In this study, bacterial communities in floodwaters of rice fields were monitored during the vegetative and reproductive stages of rice plant development using 16S amplicon sequencing. The study was conducted in the south of Brazil, during the crop years 2011/12 and 2012/13. Comparative analyses showed strong differences between the communities of floodwaters associated with the two developmental stages. During the vegetative stage, 1551 operational taxonomic units (OTUs) were detected, while less than half that number (603) were identified in the reproductive stage. The higher bacterial richness observed in floodwater collected during the vegetative stage may have been favored by the higher concentration of nutrients, such as potassium, due to rhizodeposition and fertilizer application. Eighteen bacterial phyla were identified in both samples. Both communities were dominated by Gammaproteobacteria. In the vegetative stage, Alphaproteobacteria and Betaproteobacteria were more abundant and, in contrast, Bacilli and Clostridia were the more dominant classes in the reproductive stage. The major bacterial taxa identified have been previously identified as important colonizers of rice fields. The richness and composition of bacterial communities over cultivation time may contribute to the sustainability of the crop.