Antibacterial mechanism of Biochanin A and its efficacy for the control of Xanthomonas axonopodis pv. glycines in soybean.

BACKGROUND: Xanthomonas axonopodis pv. glycines (Xag) is a hazardous pathogen able to cause bacterial pustule disease in soybean, reducing crop yield and quality. Although flavonoids rutin and genistein are known to play an important role in soybean defence, soybean is only able to produce Biochanin A in low concentration. RESULTS: In this work, Biochanin A was found to produce higher antibacterial activity against Xag in comparison with genistein (minimum inhibitory concentration < 100 µg/mL). Biochanin A was able to inhibit DNA synthesis and flagella formation in Xag, and altered the composition of the bacterial membrane. These effects reduced swimming motility, extracellular protease activity and biofilm formation. Further, Biochanin A was tested for the control of Xag in soybean leaves, showing similar, or even higher, inhibitory ability in comparison with some products commonly used for the control of this pathogen. CONCLUSIONS: The antibacterial properties of Biochanin A against Xag have been studied for the first time, revealing new insights on the potential applications of this isoflavonoid for the management of bacterial pustule disease. © 2020 Society of Chemical Industry.

[Observation on the therapeutic effects of negative-pressure wound therapy on the treatment of complicated and refractory wounds].

OBJECTIVE: To study the effects of negative-pressure wound therapy (NPWT) on the treatment of complicated and refractory wounds. METHODS: Sixty-seven patients with complicated or refractory wounds admitted to our hospital from September 2005 to November 2008 were randomly divided into NPWT group (n = 35) and conventional treatment (CT) group (n = 32). Wounds of patients in NPWT group were treated with interrupted suction under a pressure of -16.63 kPa for 24 hs, or continuous suction under a pressure of -10.64 kPa for 24 hs. Wounds of patients in CT group were covered with petrolatum gauze overlaid with isotonic saline gauze and dry gauze. Duration of treatment, times of operation, treatment cost, and the process of healing were compared between two groups. RESULTS: The duration of treatment, treatment cost and times of operation of patients in NPWT group were obviously less or fewer than those of CT group (P < 0.05). Wounds of patients in NPWT group were mainly healed by themselves (40.0%) or healed after free skin grafting (40.0%). While wounds in patients in CT group healed mainly after tissue flap transplantation (66.7%) or free skin grafting (23.3%). CONCLUSIONS: Compared with CT, NPWT can shorten the length of hospital stay, reduce operation frequency and treatment cost, and it is easier to carry out in the surgery of treating complicated and refractory wounds, which is worth generalization.

[A comparative study of the clinical effects between two kinds of negative-pressure wound therapy].

OBJECTIVE: To compare the differences of the clinical effects, side effects and treatment-related cost between two kinds of negative-pressure wound therapy (NPWT). METHODS: Forty-four inpatients with acute, subacute, and chronic wounds were divided into simplified NPWT group (A group) and conventional NPWT group (B group) according to the random number table. Wounds of patients in A group were treated with gauze + continuous suction with hospital central negative pressure (-10.64 kPa) for 24 hs; wounds of patients in B group were treated with sponge + interrupted suction with a purpose-designed suction appliance (-16.63 kPa) for 24 hs. Gross wound condition, treatment time, survival rates of skin graft and flap, changes of bacterial species on wound, treatment cost, and ratio of side effects between two groups were compared. RESULTS: There was no significant difference between A and B groups in respect of gross wound condition, treatment time [A group (29 +/- 12) d, B group (26 +/- 13) d, P > 0.05], changes of bacterial species, survival rates of skin graft [A group (98 +/- 4)%, B group (98 +/- 4)%, P > 0.05] and flap (A group 98%, B group 100%, P > 0.05). Treatment cost of A group yen(374 +/- 134) was obviously lower than that of B group yen(9825 +/- 4956) (P < 0. 01), while more side effects were observed in A group (33.3%) than that in B group (5.0%) (P < 0.05). CONCLUSIONS: Both simplified NPWT and NPWT with purpose-designed appliance can effectively improve wound healing. The simplified method may cause many side effects and has a potential risk of inciting nosocomial infection, but it can be conveniently employed with a low cost. In contrast, the cost of using purpose-designed appliance should be cut down to meet the aim of generalization.