In this study, we tested the ability of sodium dehydroacetate (SD) to extend the shelf-life of ‘Kyoho’ grape.  Among the different concentrations of SD tested (0, 0.01, 0.1 and 1.0 mmol L^–1), 0.01 mmol L^–1 SD was the most effective in prolonging the shelf-life of ‘Kyoho’ grape.  Compared with the control, the weight loss rate, browning index and hydrogen peroxide (H₂O₂) and malonaldehyde contents were significantly lower in the 0.01 mmol L^–1 SD treatment, whereas the healthy berry rate, berry firmness, total soluble solids (TSS) content, ascorbic acid content and superoxide dismutase (SOD) activity were significantly higher.  In addition, an analysis of ‘Kyoho’ grape DNA using methylation sensitive amplification polymorphism (MSAP) markers showed that the average DNA methylation level was significantly higher in the 0.01 mmol L^–1 SD treatment than in the control.  Together, these results indicate that 0.01 mmol L^–1 SD could be used to extend the shelf-life of ‘Kyoho’ grape.  Moreover, a strong connection between reactive oxygen species (ROS) metabolism and DNA methylation change during storage was revealed.

To characterize the β-lactam resistance in veterinary clinical isolates of Haemophilus parasuis, 115 isolates were examined for the β-lactam resistance, the possession of β-lactamase, and the presence of β-lactamase genes. The genetic relationship among isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Overall, the commonly detected resistance phenotypes were resistant to ampicillin (26.09%), penicillin (22.61%), amoxicillin (21.74%), cefazolin (14.78%), cefaclor (12.17%), and cefotaxime (6.96%). These strains showed high minimal inhibitory concentration (MICs) to oxacillin. 20.87% strains produced β-lactamase, and 4.35% strains showed extended-spectrum b-lactamase (ESBL) phenotype. Moreover, 19 strains harboured bla genes including TEM-1 (n=5), TEM-116 (n=10), and ROB-1 (n=5). Significantly, one strain possessed both TEM-1 and ROB-1, and displayed resistance to cefotaxime (MIC=8 mg L-1). The epidemiological analysis of PFGE revealed high genetic diversity among bla-positive isolates. This work shows that TEM- and ROB-type β-lactamases are prevalent in H. parasuis isolates in China.