Impact of ultra-high-pressure treatment on microbial community composition and flavor quality of jujube juice: Insights from high-throughput sequencing technology, intelligent bionic sensory system, and metabolomics approach.

Ultra-high-pressure (UHP1) technology for cold pasteurization is a viable alternative to traditional heat sterilization for preserving food nutrients and flavor compounds during fruit juice processing. In this study, cutting-edge techniques, including high-throughput sequencing technology, intelligent bionic sensory systems, and metabolomics, were used to examine the impact of UHP treatment on microbial community composition, odor, and taste quality of jujube juice. The UHP treatment demonstrated its effect by inducing a reddish-yellow color in the jujube juice, thereby enhancing its brightness, overall color, and stability. The most significant enhancement was observed at 330 MPa. The microorganisms responsible for spoilage and deterioration of jujube juice during storage were categorized into three clusters: bacterial clusters at 0-330 MPa, 360-450 MPa, and 480-630 Mpa. The results showed no distinct distribution patterns for fungi based on the pressure strength. The dominant bacterial genera were Lactobacillus, Nocardia, Achromobacter, Enterobacter, Pseudomonas, Mesorhizobium, and Rhodococcus, whereas the dominant fungal genera were yeast and mold. Notably, Lactobacillus, Achromobacter, Enterobacter, and Pseudomonas were responsible for the significant differences between the 360 MPa to 450 MPa and 480 MPa to 630 MPa clusters in terms of bacterial spoilage, whereas Torulaspora, Lodderomyces, Wickerhamomyces, and Fusarium were the primary fungal spoilage genera. UHP treatment exerted no significant impact on the taste of jujube juice but influenced its sourness. Treatment at 330 MPa had the most pronounced effect on the presence of aromatic compounds and other odorants, which were substantially increased. Further analysis revealed the prevalence of organic acids, such as malic acid, succinic acid, and tartaric acid, in jujube juice and demonstrated a consistent relationship between changes in organic acids and sourness. In addition, nine distinct odorants with VIP values greater than 1 were identified in the jujube juice. Among these, methyl acetate and methyl caproate exhibited substantial increases following the UHP treatment at 330 MPa.

The ever-changing microenvironment of Staphylococcus aureus in cutaneous infections.

BACKGROUND: Staphylococcus aureus is responsible for the majority of skin and soft tissue infections, which are often diagnosed at a late stage, thereby impacting treatment efficacy. Our study was designed to reveal the physiological changes at different stages of infection by S. aureus through the combined analysis of variations in the skin microenvironment, providing insights for the diagnosis and treatment of S. aureus infections. METHODS: We established a murine model of skin and soft tissue infection with S. aureus as the infectious agent to investigate the differences in the microenvironment at different stages of infection. By combining analysis of the host immune status and histological observations, we elucidate the progression of S. aureus infection in mice. RESULTS: The results indicate that the infection process in mice can be divided into at least two stages: early infection (1-3 days post-infection) and late infection (5-7 days post-infection). During the early stage of infection, notable symptoms such as erythema and abundant exudate at the infection site were observed. Histological examination revealed infiltration of numerous neutrophils and bacterial clusters, accompanied by elevated levels of cytokines (IL-6, IL-10). There was a decrease in microbial alpha diversity within the microenvironment (Shannon, Faith's PD, Chao1, Observed species, Simpson, Pielou's E). In contrast, during the late stage of infection, a reduction or even absence of exudate was observed at the infected site, accompanied by the formation of scabs. Additionally, there was evidence of fibroblast proliferation and neovascularization. The levels of cytokines and microbial composition gradually returned to a healthy state. CONCLUSION: This study reveals synchrony between microbial composition and histological/immunological changes during S. aureus-induced SSTIs.