Assessment of overall microbial community shift during Cheddar cheese production from raw milk to aging.

Cheese is a fermented dairy product that is made from animal milk and is considered to be a healthy food due to its available nutrients and potential probiotic characteristics. Since the microbes in the cheese matrix directly contribute to the quality and physicochemical properties of cheese, it is important to understand the microbial properties of cheese. In this study, Cheddar cheeses produced on three different dates at the Arbuthnot Dairy Center at Oregon State University were collected to determine the microbial community structure. A total of 773,821 sequencing reads and 271 amplicon sequence variants (ASVs) were acquired from 108 samples. Streptococcus and Lactococcus were observed as the most abundant ASVs in the cheese, which were used as the starter lactic acid bacteria (SLAB). Escherichia coli was detected in the raw milk; however, it was not detected after inoculating with SLAB. According to an alpha diversity analysis, SLAB inoculation decreased the microbial richness by inhibiting the growth of other bacteria present in the milk. A beta diversity analysis showed that microbial communities before the addition of SLAB clustered together, as did the samples from cheese making and aging. Non-starter lactic acid bacteria (NSLAB) were detected 15 weeks into aging for the June 6th and June 26th produced cheeses, and 17 weeks into aging for the cheese produced on April 26th. These NSLAB were identified as an unidentified group of Lactobacillaceae. This study characterizes the changes in the Cheddar cheese microbiome over the course of production from raw milk to a 6-month-aged final product. KEY POINTS: • 271 ASVs were acquired from cheese production from raw milk to 6-month aging. • Addition of SLAB changed the microbial diversity during Cheddar cheese making procedure. • NSLAB were detected more than 15 weeks after aging. Graphical Abstract.

Effect of atractylenolide III on zearalenone-induced Snail1-mediated epithelial-mesenchymal transition in porcine intestinal epithelium.

BACKGROUND: The intestinal epithelium performs essential physiological functions, such as nutrient absorption, and acts as a barrier to prevent the entry of harmful substances. Mycotoxins are prevalent contaminants found in animal feed that exert harmful effects on the health of livestock. Zearalenone (ZEA) is produced by the Fusarium genus and induces gastrointestinal dysfunction and disrupts the health and immune system of animals. Here, we evaluated the molecular mechanisms that regulate the effects of ZEA on the porcine intestinal epithelium. RESULTS: Treatment of IPEC-J2 cells with ZEA decreased the expression of E-cadherin and increased the expression of Snai1 and Vimentin, which induced Snail1-mediated epithelial-to-mesenchymal transition (EMT). In addition, ZEA induces Snail-mediated EMT through the activation of TGF-ß signaling. The treatment of IPEC-J2 cells with atractylenolide III, which were exposed to ZEA, alleviated EMT. CONCLUSIONS: Our findings provide insights into the molecular mechanisms of ZEA toxicity in porcine intestinal epithelial cells and ways to mitigate it.

Assessment of Chicken Carcass Microbiome Responses During Processing in the Presence of Commercial Antimicrobials Using a Next Generation Sequencing Approach.

The purpose of this study was to 1) identify microbial compositional changes on chicken carcasses during processing, 2) determine the antimicrobial efficacy of peracetic acid (PAA) and Amplon (blend of sulfuric acid and sodium sulfate) at a poultry processing pilot plant scale, and 3) compare microbial communities between chicken carcass rinsates and recovered bacteria from media. Birds were collected from each processing step and rinsates were applied to estimate aerobic plate count (APC) and Campylobacter as well as Salmonella prevalence. Microbiome sequencing was utilized to identify microbial population changes over processing and antimicrobial treatments. Only the PAA treatment exhibited significant reduction of APC at the post chilling step while both Amplon and PAA yielded detectable Campylobacter reductions at all steps. Based on microbiome sequencing, Firmicutes were the predominant bacterial group at the phyla level with over 50% frequency in all steps while the relative abundance of Proteobacteria decreased as processing progressed. Overall microbiota between rinsate and APC plate microbial populations revealed generally similar patterns at the phyla level but they were different at the genus level. Both antimicrobials appeared to be effective on reducing problematic bacteria and microbiome can be utilized to identify optimal indicator microorganisms for enhancing product quality.

Characterization and miRNA-mediated posttranscriptional regulation of vitelline membrane outer layer protein I in the adult chicken oviduct.

The laying hen is the best model for oviduct growth and development. The chicken oviduct produces the egg components, including the egg white and eggshell. However, the mechanism of egg component production during oviduct development requires further investigation. Vitelline membrane outer layer protein 1 (VMO-1) is found in the outer layer of the vitelline membrane of avian eggs. Comparison of the chicken VMO-1 protein-coding sequence and the human, mouse, rat, and bovine VMO-1 proteins via multiple sequence alignment analysis revealed high degrees of homology of 55%, 53%, 48%, and 54%, respectively. Although the avian homologue of VMO-1 is highly expressed in the magnum of the oviduct, little is known about the transcriptional and posttranscriptional regulation of VMO-1 during oviduct development. The results of this study revealed that estrogen induces VMO-1 messenger RNA (mRNA) expression in oviduct cells in vitro. The expression of genes interacting with VMO-1 by RNA interference (RNAi) functional analysis revealed that ovomucin expression was decreased by VMO-1 silencing. In addition, gga-miR-1623, 1552-3p, and 1651-3p influenced VMO-1 expression via its 3'-UTR, suggesting the posttranscriptional regulation of VMO-1 expression in chickens. Collectively, these results suggest that VMO-1 is an estrogen-induced gene that is posttranscriptionally regulated by microRNAs (miRNAs). The present study may contribute to an understanding of egg component production during chicken oviduct development.

Gene expression profile of human peripheral blood mononuclear cells induced by Staphylococcus aureus lipoteichoic acid.

Lipoteichoic acid (LTA) is a major virulence factor of Gram-positive bacteria including Staphylococcus aureus. Despite its pivotal role in causing sepsis, the systemic immune responses to LTA in human cells are poorly understood. Here, we produced highly-pure and structurally-intact LTA from S. aureus and examined the gene expression profile of LTA-stimulated human peripheral blood mononuclear cells (PBMCs). The LTA preparation did not contain any detectable biologically-active impurities and stimulated Toll-like receptor 2. Protein expression profiling using a cytokine array kit and ELISA revealed expression of MCP-1/CCL2, IL-6, and IL-1ß. We performed transcriptional profiling of PBMCs in response to S. aureus LTA using an Affymetrix genechip microarray. A total of 208 genes were significantly (fold change>1.5 and P<0.05) altered, with 157 up-regulated and 51 down-regulated genes in response to S. aureus LTA treatment. The up-regulated genes were involved in recognition (30 genes), cellular adhesion (6 genes), signal transduction (42 genes), co-stimulation (4 genes), chemokines, cytokines and their receptors (51 genes), apoptosis (9 genes), and negative regulation (15 genes). The down-regulated genes were involved in recognition (12 genes), antigen processing and presentation (9 genes), signal transduction (27 genes), and chemotaxis (3 genes). The microarray results were validated using real-time RT-PCR with 21 up-regulated genes and 9 down-regulated genes. Our results provide a more comprehensive overview of the transcriptional changes in PBMCs in response to S. aureus LTA, and contribute to the understanding of the pathophysiological role of S. aureus LTA during the systemic inflammatory response.