Non-epidermidis coagulase-negative Staphylococcus isolated from farm animals can inhibit the hemagglutinating activity of Newcastle disease virus and bovine parainfluenza virus type 3

The Embp protein of Staphylococcus epidermidis inhibits the hemagglutination of the H1N1 influenza virus and protects birds from a viral respiratory infection. Several species of Coagulase-negative Staphylococcus (CoNS) are present in the respiratory cavity, particularly in nostrils. We hypothesize that non-epidermidis CoNS found in animals can have the same function as observed in S. epidermidis. Thirty Non-epidermidis CoNS isolates were obtained from poultry, sheep, goat, pig, and dairy cow nostrils. Haemagglutination inhibition (HI) activity was assayed in bacteria-free supernatants from non-epidermidis CoNS against Newcastle disease virus (NDV) and bovine parainfluenza virus type 3 (BPIV). In 13 of the 30 strains (43.3 %), bacteria-free supernatants showed HI activity for NDV and BPIV-3. Staphylococcus xylosus supernatants from poultry (one isolate), sheep (two isolates), goat (one isolate), and dairy cow (three isolates) had the highest frequency of HI activity on NDV and BPIV-3, followed by Staphylococcus sp. supernatants from goat (one isolate), dairy cow (two isolates), and finally Staphylococcus equorum, Staphylococcus chromogens and Staphylococcus gallinarum supernatants with single isolation from poultry, pig and poultry, respectively. Nine isolates had the homologous gene to the embp gene of S. epidermidis, and it was associated with HI activity in the studied viruses. By Pulsed‐field gel electrophoresis, S. xylosus isolates showed to be different clones and related to the origin of isolation and HI activity. These results demonstrate that non-epidermidis CoNS supernatants from different animals and origins have the ability of HI on NDV and BPIV-3, indicating that not only S. epidermidis has the same function.     

Supernatant solution phosphorus concentrations required by five soybean (Glycine max) cultivars

Abstract

Dry matter yields at flowering and seed yield responses of five soybean cultivars (Bragg, Semstar, Flegler, Davis and Wills) to six soil phosphorus levels in an Oxic Paleustalf were determined in a pot experiment. Ninety percent maximum dry matter yield at flowering was attained at the following supernatant solution P concentrations (determined from P sorption curves): Bragg, 0.012 μg ml^‐1; Davis, 0.009 μg ml^‐1; Semstar, 0.010 μg ml^‐1; Flegler, 0.011 μg ml^‐1; Wills, 0.012 μg ml^‐1. Ninety percent maximum seed yield was attained at a supernatant solution P concentration of 0.007 μg ml^‐1 by Bragg, Semstar, Flegler and Wills. Davis required 0.011 μg P ml^‐1 for 90% maximum seed yield.

It is concluded from these results that Bragg, Semstar, Flegler and Wills will have similar phosphorus fertilizer requirements, but Davis will require larger additions of phosphorus than the other cultivars for maximum seed yield.     

全血培养与酶标仪联用检测淋巴细胞转化的研究

随机将60只健康两周龄雏鸡分成两组：静脉注射顺铂的抑制组（Y）与空白对照（D）。动物处理三天后无菌采血,进行全血培养和淋巴细胞转化试验。培养24 h、48 h、72 h、96 h、120 h 时分别吸取上清离心,在酶标仪570 nm 处读数绘图分析;同时进行MTT比色试验,测定570 nm 处OD值绘制曲线图比较分析。将全血法72 h时的离心上清、MTT法48 h时的蓝色细胞悬液在酶标仪570 nm直接读数;吹打数次和数分钟后同样条件下各读数一次;室温过夜后再读一次;对OD值相对于均值位置进行分析。结果表明：全血培养上清吸光度的测定同MTT比色法一样能够反映出淋巴细胞转化情况,该法在试验可重复性方面明显优于MTT法。