Yu He

Physalis alkekengi L. has attracted widespread attention and cultivation due to its unique lantern-shaped fruit and various bioactivities. Existing studies have mainly focused on its fruit, while the calyx, despite its significant bioactivity, has long been neglected. In particular, research on the changes in polyphenol content and antioxidant activity during its drying process remains scarce. This study aimed to optimize the extraction process, comprehensively profile the polyphenol composition, and evaluate the effects of the drying temperature on the polyphenol content and antioxidant capacity in the calyx of Physalis alkekengi L. (CPAL). Ultrasound-assisted extraction (40 kHz, 300 W) combined with response surface methodology was used to optimize the extraction conditions. The optimized parameters were determined as a 49% ethanol concentration, a 42 mL/g liquid-to-material ratio, a 64 °C extraction temperature, and a 29 min extraction time. Under these settings, the yield reached 10.44 ± 0.16 mg GAE/g, exceeding that of the conventional heat reflux extraction method. Using high-resolution mass spectrometry, 63 polyphenolic compounds were identified, primarily derivatives of kaempferol, quercetin, and hydroxycinnamic acid; 43 of these compounds were first reported in CPAL. CPAL polyphenols possess potent antioxidant activities, with IC₅₀ values of 68.77, 12.76, and 101.24 μg/mL for DPPH, ABTS, and FRAP, respectively. Furthermore, as the drying temperature increased, the polyphenol content and antioxidant activity of CPAL increased significantly. These findings provide a scientific basis for the development of natural antioxidants and functional foods.

Vibrio parahaemolyticus is a leading seafood-borne pathogen that causes gastroenteritis, septicemia, and serious wound infections due to the actions of virulence-associated proteins. We co... HIGHLIGHTS The secretomes of toxic and nontoxic V. parahaemolyticus strains were compared. Different extracellular proteins were identified in strains ATCC 33847 (16) and JHY20 (2). ATCC 33847 secr...

The development of multidrug- and toxin-resistant bacteria as a result of increasing industrialization and sustained and intense antimicrobial use in aquaculture results in human health problems through increased incidence of food-borne illnesses. Integrative and conjugative elements (ICEs) are self-transmissible mobile genetic elements that allow bacteria to acquire complex new traits through horizontal gene transfer and encode a wide variety of genetic information, including resistance to antibiotics and heavy metals; however, there is a lack of studies of ICEs of environmental origin in Asia. Here, we determined the prevalence, genotypes, heavy metal resistance and antimicrobial susceptibility of 997 presumptive strains of Vibrio parahaemolyticus (tlh⁺, tdh^–), a Gram-negative bacterium that causes gastrointestinal illness in humans, isolated from four species of aquaculture shrimp in Jiangsu, China. We found that 59 of the 997 isolates (5.9%) were ICE-positive, and of these, 9 isolates tested positive for all resistance genes. BLAST analysis showed that similarity for the eight strains to V. parahaemolyticus was 99%. Tracing the V. parahaemolyticus genotypes, showed no significant relevance of genotype among the antimicrobial resistance strains bearing the ICEs or not. Thus, in aquaculture, ICEs are not the major transmission mediators of resistance to antibiotics or heavy metals. We suggest future research to elucidate mechanisms that drive transmission of resistance determinants in V. parahaemolyticus.

Vibrio parahaemolyticus is a causative agent of human serious seafood-borne gastroenteritis disease and even death. Shrimps, often eaten raw or undercooked, are an important reservoir of the bacterium. In this study, we isolated and characterized a total of 400 V. parahaemolyticus strains from commonly consumed fresh shrimps (Litopenaeus vannamei, Macrobrachium rosenbergii, Penaeus monodon, and Exopalaemon carinicauda) in Shanghai fish markets, China in 2013–2014. The results revealed an extremely low occurrence of pathogenic V. parahaemolyticus carrying two major toxic genes (tdh and trh, 0.0 and 0.5 %). However, high incidences of antibiotic resistance were observed among the strains against ampicillin (99 %), streptomycin (45.25 %), rifampicin (38.25 %), and spectinomycin (25.50 %). Approximately 24 % of the strains derived from the P. monodon sample displayed multidrug resistant (MDR) phenotypes, followed by 19, 12, and 6 % from the E. carinicauda, L. vannamei, and M. rosenbergii samples, respectively. Moreover, tolerance to heavy metals of Cr³⁺ and Zn²⁺ was observed in 90 antibiotic resistant strains, the majority of which also displayed resistance to Cu²⁺ (93.3 %), Pb²⁺ (87.8 %), and Cd²⁺(73.3 %). The pulsed-field gel electrophoresis (PFGE)-based genotyping of these strains revealed a total of 71 distinct pulsotypes, demonstrating a large degree of genomic variation among the isolates. The wide distribution of MDR and heavy-metal resistance isolates in the PFGE clusters suggested the co-existence of a number of resistant determinants in V. parahaemolyticus population in the detected samples. This study provided data in support of aquatic animal health management and food safety risk assessment in aquaculture industry.