Despite Bacillus species having been extensively utilized in the food industry and biocontrol as part of probiotic preparations, limited knowledge exists regarding their impact on intestinal disorders. In this study, we investigated the effect of Bacillus licheniformis ZW3 (ZW3), a potential probiotic isolated from camel feces, on dextran sulfate sodium (DSS)-induced colitis. The results showed ZW3 partially mitigated body weight loss, disease activity index (DAI), colon shortening, and suppressed immune response in colitis mice, as evidenced by the reduction in the levels of the inflammatory markers IL-1β, TNF-α, and IL-6 (p < 0.05). ZW3 was found to ameliorate DSS-induced dysfunction of the colonic barrier by enhancing mucin 2 (MUC2), zonula occluden-1 (ZO-1), and occludin. Furthermore, enriched beneficial bacteria Lachnospiraceae_NK4A136_group and decreased harmful bacteria Escherichia-Shigella revealed that ZW3 improved the imbalanced gut microbiota. Abnormally elevated uric acid levels in colitis were further normalized upon ZW3 supplementation. Overall, this study emphasized the protective effects of ZW3 in colitis mice as well as some potential applications in the management of inflammation-related diseases.

Background: Mycoplasma ovipneumoniae (M. ovipneumoniae) is one of the main pathogens of sheep pneumonia, causing a series of clinical symptoms, such as depression, anorexia, hyperthermia, cough, dyspnea, and tract secretions. In recent years, the prevalence of M. ovipneumoniae pneumonia has become increasingly serious in sheep farms in Ningxia, China, leading to the death of sheep, and causing significant economic losses. In this study, the pathological organs infected by M. ovipneumoniae were collected to observe histopathological change, to determine the tissue localization of M. ovipneumoniae, and to analyze the cytokine changes, which lays a basis for the diagnosis and pathogenesis of M. ovipneumoniae disease. Results: In this study, M. ovipneumoniae was detected in 97 of 105 samples collected from 13 large-scale sheep farms for nucleic acid by PCR. One representative isolate per farm was isolated from 13 farms. The lesions caused by M. ovipneumoniae were mainly in the trachea, bronchus, and lung, including necrosis of tracheal mucosal epithelial cells, disintegration of some epithelial cells, edema of mucosal lamina propria, with inflammatory cell infiltration, cytoplasmic vacuolization of epithelial cells of bronchial mucosa, massive infiltration of inflammatory cells in the alveolar space of lung, necrosis and hyperplasia of alveolar epithelial cells. Immunohistochemical analysis showed that the proportion of M. ovipneumoniae positive area in the lung was the largest, followed by that in the bronchus and trachea. Compared to healthy animals, diseased animals exhibited up-regulated gene expression levels of IL-1β, IL-6, and NF-κB in the trachea, bronchus, and lungs. In contrast, the expression of IL-10, IL-12, and IFN-γ was primarily limited to the trachea and bronchus. The expression of IL-1β showed differential patterns across different lung regions, with variations observed among lung lobes. Additionally, other cytokines consistently showed significant up-regulation specifically in the bronchus. Conclusions: M. ovipneumoniae is primarily found in the lungs of infected individuals. NF-κB, an essential transcription factor, is involved in the regulation of IL-1β transcription. IL-12 may enhance the cytotoxic function of natural killer cells during M. ovipneumoniae infection. Those findings demonstrate the distinct expression profiles of cytokines in various anatomical sites throughout disease progression, suggesting the potential role of bronchial tissue as a major site of immune response.

Background: Ningxia Hui Autonomous Region is an important cattle breeding area in China, and cattle breeding bases are located in this area. In Ningxia, dermatophytes have not been paid attention to, so dermatophytosis is becoming more and more serious. For effective control measures, it is important to determine the disease prevalence and isolate and identify the pathogenic microorganism. Results: The study showed the prevalence of dermatophytes was 15.35% (74/482). The prevalence in calf was higher than adult cattle (p < 0.05). The morbidity was the highest in winter compared with autumn (p < 0.0001), summer (p < 0.05) and spring (p < 0.0001). The prevalence in Guyuan was the highest compared with Yinchuan (p < 0.05) and Shizuishan (p < 0.05). The incidence of lesions on the face, head, neck, trunk and whole body was 20.43, 38.71, 20.43, 10.75 and 9.68%, respectively. From all samples, the isolation rate of Trichophyton was highest (61.1%). The phylogenetic tree constructed showed that the 11 pathogenic fungi were on the same branch as Trichophyton verrucosum. Conclusions: This study reports, for the first time, the presence of Trichophyton verrucosum in cattle in Ningxia and showed that the incidence of dermatophytosis is related to different regions, ages and seasons. A better knowledge of the prevalence of dermatophytosis of cattle may allow the adoption of more efficient control measures and prophylaxis.

Penicillium oxalicum is an important fungal agent in the composting of cattle manure, but the changes that occur in the microbial community, physicochemical factors, and potential functions of microorganisms at different time points are still unclear. To this end, the dynamic changes occurring in the microbial community and physicochemical factors and their correlations during the composting of cattle manure with Penicillium oxalicum were analysed. The results showed that the main phyla observed throughout the study period were Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Halanaerobiaeota, Apicomplexa and Ascomycota. Linear discriminant analysis effect size (LEfSe) illustrated that Chitinophagales and Eurotiomycetes were biomarker species of bacteria and eukaryote in samples from Days 40 and 35, respectively. Bacterial community composition was significantly correlated with temperature and pH, and eukaryotic microorganism community composition was significantly correlated with moisture content and NH4+-N according to redundancy analysis (RDA). The diversity of the microbial communities changed significantly, especially that of the main pathogenic microorganisms, which showed a decreasing trend or even disappeared after composting. In conclusion, a combination of high-throughput sequencing and physicochemical analysis was used to identify the drivers of microbial community succession and the composition of functional microbiota during cattle manure composting with Penicillium oxalicum. The results offer a theoretical framework for explaining microecological assembly during cattle manure composting with Penicillium oxalicum.

Probiotics are a prominent alternative to antibiotics in antimicrobial-free broiler farming. To assess the effect of Sphingomonas sp. Z392 (isolated and identified) on broiler growth, 600 one-day-old Kebao broiler chickens were randomly divided into a control group and an experimental group. Each group had three replicates, with 100 broiler chickens being raised in each replicate. Regarding the experimental group of broiler chickens, 4.0 × 10⁵ CFU/mL of Sphingomonas Z392 was added to their drinking water. Then, the changes in broiler body weight, the EPI, intestinal histological structure, and gut microbiota were examined. The results show that the supplementation of the broilers’ drinking water with 4 × 10⁵ CFU/mL of Sphingomonas Z392 resulted in an increase in the relative abundance of Lactobacillus, Bacteroides, Lachnospiraceae, Aminobacterium, Oribacterium, Christensenellaceae, Faecalibacterium, Barnesiella, Ruminococcus, Parabacteroides, Phascolarctobacterium, Butyricicoccaceae, and Caproiciproducens, which have been reported to be positively correlated with the improved digestion and absorption of broiler chickens. The relative abundance of Odoribacter, Alistipes, Parabacteroides, and Rikenellaceae increased, and these have been reported to be negatively correlated with the occurrence of intestinal diseases. The relative abundance of Campylobacter, Shigella Castellani, Bilophila, Campylobacter, Clostridia, and Anaerotruncus decreased, and these have been reported to be positively correlated with the occurrence of intestinal diseases. At the same time, the following also increased: the integrity of small intestinal villus morphology; the number of goblet cells in small intestinal epithelial cells; the health of the mitochondria in the cytoplasm of jejunal villous epithelial cells; the number of lysosomes in the cytoplasm of goblet cells in the small intestinal epithelium, ileal villous epithelial cells, and mitochondria in the cytoplasm of large intestinal villous epithelial cells; the VH/CD of the ileum; and digestive, absorption, and defense capabilities. In particular, the final weight increased by 4.33%, and the EPI increased by 10.10%. Therefore, the supplementation of broiler drinking water with Sphingomonas generated better economic benefits from the broiler chickens.

Salmonella enterica serovar Typhimurium (S. Tm) causes severe foodborne diseases. Interestingly, gut microbial tryptophan (Trp) metabolism plays a pivotal role in such infections by a yet unknown mechanism. This study aimed to explore the impact of Trp metabolism on S. Tm infection and the possible mechanisms involved. S. Tm–infected C57BL6/J mice were used to demonstrate the therapeutic benefits of the Bacillus velezensis JT3-1 (B. velezensis/JT3-1) strain or its cell-free supernatant in enhancing Trp metabolism. Targeted Trp metabolomic analyses indicated the predominance of indole-3-lactic acid (ILA), an indole derivative and ligand for aryl hydrocarbon receptor (AHR). Based on the 16S amplicon sequencing and correlation analysis of metabolites, we found that B. velezensis supported the relative abundance of Lactobacillus and Ligilactobacillus in mouse gut and showed positive correlations with ILA levels. Moreover, AHR and its downstream genes (especially IL-22) significantly increased in mouse colons after B. velezensis or cell-free supernatant treatment, suggesting the importance of AHR pathway activation. In addition, ILA was found to stimulate primary mouse macrophages to secrete IL-22, which was antagonized by CH-223191. Furthermore, ILA could protect mice from S. Tm infection by increasing IL-22 in Ahr+/− mice, but not in Ahr−/− mice. Finally, Trp-rich feeding showed amelioration of S. Tm infection in mice, and the effect depended on gut microbiota. Taken together, these results suggest that B. velezensis–associated ILA contributes to protecting mice against S. Tm infection by activating the AHR/IL-22 pathway. This study provides insights into the involvement of microbiota-derived Trp catabolites in protecting against Salmonella infection.