This study was conducted to reveal the prevalence, molecular characterization, and antibiotic susceptibility of Bacillus cereus isolated from dairy products including powdered infant formula, raw milk, pasteurized milk, ultra-high-temperature milk, and cheese. Five hundred samples collected from 5 provinces in China were analyzed in overall experiments. Multilocus sequence typing, distribution of toxin genes, and antibiotic susceptibility of the isolates were analyzed. Fifty-four B. cereus strains were detected; of these, 13 isolates (26%) were from raw milk, 12 isolates (12%) from pasteurized milk, 10 isolates (10%) from cheese, 12 isolates (8%) from ultra-high-temperature milk, and 7 isolates (7%) from powdered infant formula. These isolates were divided into 24 sequence types (ST); among them, ST24, ST26, ST82, ST142, ST377, ST857, and ST1046 were the main dominant ST. The results of detection of toxin genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, bceT, hlyII, and cesB) showed that 94.4% isolates carried nheABC genes, whereas only 11.1% of the isolates contained the hblACD gene cluster. In addition, detection rates of cytK, bceT, entFM, hlyII, and cesB genes were 75.9, 77.8, 85.2, 53.7, and 11.1%, respectively. The antibiotic susceptibility test indicated that most of B. cereus isolates were resistant to ampicillin, penicillin, cefepime, cephalothin, and oxacillin, and were susceptible to gentamicin, chloramphenicol, imipenem, tetracycline, ciprofloxacin, trimethoprim-sulfamethoxazole, erythromycin, kanamycin, and cefotetan. Therefore, this study revealed the prevalence and characteristics of B. cereus isolated from dairy products in China, indicating the potential risk and contributing to the effective prevention and control of this pathogen.

Reactive oxygen species (ROS) are involved in the pathologic process of pulmonary arterial hypertension as either mediators or inducers. Rutin is a type of flavonoid which exhibits significant scavenging properties on oxygen radicals both in vitro and in vivo. In this study, we proposed that rutin attenuated hypoxia-induced pulmonary artery smooth muscle cell (PASMC) proliferation by scavenging ROS. Immunofluorescence data showed that rutin decreased the production of ROS, which was mainly generated through mitochondria and NADPH oxidase 4 (Nox4) in pulmonary artery endothelial cells (PAECs). Western blot results provided further evidence on rutin increasing expression of Nox4 and hypoxia-inducible factor-1α (HIF-1α). Moreover, cell cycle analysis by flow cytometry indicated that proliferation of PASMCs triggered by hypoxia was also repressed by rutin. However, N-acetyl-L-cysteine (NAC), a scavenger of ROS, abolished or diminished the capability of rutin in repressing hypoxia-induced cell proliferation. These data suggest that rutin shows a potential benefit against the development of hypoxic pulmonary arterial hypertension by inhibiting ROS, subsequently preventing hypoxia-induced PASMC proliferation.

Modified starch films are gaining attention as biodegradable and sustainable materials in the food packaging industry. However, their inherent properties, including their brittleness and low antimicrobial and antioxidant capacities, limit their extensive application. To address these shortcomings, in this study, a composite film was developed using potato-modified starch (PMS) as the base material, enhanced with konjac glucomannan (KGM), Pleurotus citrinopileatus polysaccharide (PCP), and nano titanium dioxide (nano TiO2). Additionally, PCP and nano TiO2, which are bioactive components, were incorporated to improve the functional properties of the films, promoting their application in food preservation. The optimal composition of the composite films was determined through a fuzzy comprehensive evaluation, and the best performance was achieved with 10 g/L of PCP and 1.5 g/L of nano TiO2. These composite films exhibited high mechanical strength, antimicrobial capacity, and antioxidant capacity while being noncytotoxic. The practical efficacy of the composite films was verified by applying them to preserve fresh-cut yams at room temperature, where they effectively delayed spoilage and maintained yam quality. This study demonstrates that PMS/KGM/PCP/nano TiO2 composite films can significantly enhance the shelf life of fresh produce, providing a viable route for eco-friendly food preservation.

In this study, sea buckthorn polysaccharides (SBP) were added as functional substances to chitosan (CS), and chitosan/sea buckthorn polysaccharide (SCS) composite films were prepared using the casting method. The effects of SBP addition on the optical properties, physical properties, mechanical properties, structure, antioxidant activity, and antibacterial activity of the SCS composite films were studied, and the prepared SCS composite films were used to preserve yellow cherry tomatoes. The results showed that SCS composite films exhibited good UV resistance, water solubility, and antioxidant activity, but its apparent structure, hydrophobicity, and mechanical properties needed further improvement. Meanwhile, SBP has inhibitory effects on all 8 experimental strains. In addition, the SCS composite film with the addition of 200 mg/L SBP could reduce the weight loss rate of yellow cherry tomatoes, maintain hardness, delay the decrease of total soluble solids, titratable acid, and Vitamin C content, and inhibit the accumulation of malondialdehyde. SCS composite films are beneficial for enhancing the quality of yellow cherry tomatoes during storage, and their application in fruit and vegetable preservation has development prospects.