长春科技学院

This research meticulously explored the impact of five modification methods, namely microwave (M), ultrasonic (U), enzymatic hydrolysis (E), alkaline hydrogen peroxide (A), and cross-linking (C), on the structure, physicochemical properties, and functional characteristics of corn bracts insoluble dietary fibre (CBIDF). The results showed that all modifications disrupted the dense surface of CBIDF. Among them, the A-CBIDF completely shrank due to the decomposition of lignin and hemicellulose through the alkaline hydrogen peroxide treatment, and the C-CBIDF formed a fragmented network structure. All modifications significantly improved the water-holding capacity (WHC) and oil-holding capacity, with the WHC of A-CBIDF increasing by 95.14%. Microwave and ultrasonic modifications significantly enhanced swelling capacity by 23.51% and 21.92%, respectively. The C-CBIDF [2,2-diphenyl-1-picrylhydrazyl(DPPH) scavenging rate of 36.5%] and E-CBIDF (hydroxyl radical scavenging rate of 37.1%) had the best antioxidant properties, but the antioxidant property of A-CBIDF decreased due to the destruction of phenolic compounds. The glucose adsorption capacity (GAC) and nitrite adsorption capacity (NIAC) were enhanced after modification. Among them, the GAC of the U/C/A-CBIDF increased significantly, and the NIAC of E-CBIDF was the highest under gastric conditions (pH = 2.0). This study provided a theoretical basis and technical support for the high-value utilisation of corn bracts dietary fibre.

Escherichia coli (E. coli) is one of the most common commensal bacteria in the intestinal tract of humans and animals. It serves as a major reservoir of antimicrobial resistance genes and may facilitate their horizontal transfer among different hosts. In this study, 212 fecal samples were collected from mink across four northern provinces of China, a total of 110 E. coli isolates were recovered (isolation rate, 51.89 %). Preliminary antimicrobial screening was conducted using four clinically critical antibiotics, including ceftazidime (CAZ), polymyxin B (PMB), meropenem (MEM), and tigecycline (TGC), with CAZ resistance being the most prevalent, followed by PMB, MEM, and TGC. Further antimicrobial susceptibility testing against ten commonly used antibiotics in 49 representative isolates revealed universal multidrug resistance (MDR), including 100 % resistance to imipenem, tetracycline, enrofloxacin, florfenicol, and sulfamethoxazole. Genetic screening identified multiple resistance genes such as aac(3')-IIa, blaCTX-M, tet(A), and mcr-1. Conjugation assays demonstrated that CAZ resistance was the most transferable. Virulence profiling revealed a low prevalence of classical pathogenic virulence factors, with only six virulence gene types detected, consistent with the results of Galleria mellonella infection assays. Whole-genome sequencing of 41 representative isolates revealed 87 unique antibiotic resistance genes (ARGs) types spanning 14 antibiotic classes including alinically important determinants such as blaCTX-M, tet, and mcr, and 71 unique virulence genes assigned to 65 functions. Metagenomic analysis further identified diverse ARGs within the mink gut microbiota, with 21 shared between whole-genome and metagenomic sequencing. Correlation analysis suggested co-occurrence patterns among ARGs, virulence factor genes (VFGs), and mobile genetic elements (MGEs), particularly between ARGs and MGEs. Overall, mink-derived E. coli exhibited extensive MDR but limited classical pathogenic virulence, and the mink gut microbiota may represent an important reservoir and transmission hub for resistance genes in intensive farming ecosystems.

The livestock gut microbiota serves as a reservoir for antimicrobial resistance (AMR), yet Caprinae species remain understudied. Here, we present a large-scale metagenomic analysis of 779 gut samples from Caprinae animals, primarily originating from China (95.38%), including Capra hircus (79.85%) and Ovis aries (17.33%). We reconstruct 17,023 metagenome-assembled genomes (MAGs), and identify 2,440 antimicrobial resistance genes (ARGs) and 5,401 virulence factor genes (VFGs). Escherichia coli represents a major host for both. Correlation analyses between ARGs, VFGs, and mobile genetic elements (MGEs) suggest potential co-selection mechanisms. Although MGEs were detected in only 1.45% of MAGs, likely reflecting limitations in identifying MGEs within incomplete assemblies, 19 ARGs are physically co-located with MGEs, indicating mobility potential. Additionally, three ARGs are embedded within viral genomes, implicating bacteriophages in AMR dissemination. Comparative analyses reveal 184 distinct ARGs shared between Caprinae and humans, including 17 clinically critical genes such as tetX and van variants. These findings expand understanding of the Caprinae gut resistome and highlight its potential role in cross-host AMR transmission, and underscore the need for targeted AMR surveillance in this reservoir.

The global restriction of antibiotic growth promoters (AGPs) has accelerated the search for sustainable nutritional alternatives that support growth performance and intestinal health of poultry. Postbiotics and their bioactive metabolites derived from probiotic microorganisms have emerged as promising candidates due to their functional stability and immunometabolic regulatory potential. This study evaluated the effects of Lactobacillus acidophilus-derived postbiotics on growth performance, nutrient sensing, intestinal barrier integrity, immune response, antioxidant status, and gut microbiota in broiler chickens. For this purpose, a total of 400 day-old broilers were randomly assigned to four dietary treatments with graded postbiotic supplementation (0.0%, 0.5%, 1.0%, and 2.0%) for 42 days. Growth performance, immune and antioxidant indices, intestinal and hepatic histomorphology, gene expression, and cecal microbial composition were assessed. Broilers receiving 1.0% and 2.0% postbiotics exhibited significantly higher average daily gain and feed intake compared with controls (p < 0.05). Postbiotic supplementation enhanced systemic immunity, reflected by increased serum IgA, IgG, and IgM levels and elevated spleen and bursa indices. Improved intestinal morphology was evidenced by increased duodenal villus height and villus height-to-crypt depth ratio, while hepatic tissues showed reduced inflammation and fibrosis. Molecular analyzes revealed upregulation of nutrient transporters (SGLT1, PepT1), tight junction protein ZO-1, and antioxidant enzyme GPX1, alongside downregulation of pro-inflammatory cytokines (IL-1β and IL-6). Additionally, postbiotics increased the abundance of beneficial cecal taxa, including coliforms, Lactobacillus, and total plate count. Collectively, L. acidophilus-derived postbiotics improve broiler performance by coordinating nutrient transporter regulation, antioxidant signaling, and inflammatory control, supporting their application as a sustainable AGPs alternative.

Giardia, a flagellated protozoan, is widely distributed in wild rodents. To characterize the presence of Giardia in wild rodents in southern China, this study collected 344 fecal samples from wild rodents in Guangxi, Hunan, and Yunnan provinces. The β-giardin gene (bg) was amplified to identify the presence of Giardia sp. The results showed that 48 samples (13.95%, 48/344) tested positive for Giardia, including three positives for G. duodenalis (assemblage G n = 1, assemblage F n = 2) and 45 positives for G. microti. Among these, Microtus fortis had the highest prevalence at 30.22% (42/139), followed by Apodemus agrarius (7.14%, 3/42). Rattus flavipectus showed a prevalence of 2.56% (1/39), while Bandicota indica had a rate of 5.13% (2/39). The prevalence of Giardia in males (18.27%, 36/197) was slightly higher than in females (8.16%, 12/147). To the best of our knowledge, the present study reported the detection of assemblage F and assemblage G in B. indica for the first time. In addition, G. microti was found exclusively in M. fortis and a few A. agrarius. This study enriches the epidemiological data on Giardia in wild rodents and provides new insights for future research.