骆驼尿辅助治疗疾病的研究进展

尿是人类和脊椎动物为了新陈代谢的需要,经由泌尿系统及尿路排出体外的液体排泄物。近年来,骆驼尿液因具有广泛的医疗作用而引起广泛关注。在中东地区,其主要用于对疾病的辅助治疗,包括发烧、感冒甚至癌症。研究表明,骆驼尿液中含有一些独特的生物化学成分,如刀豆氨酸可在不同肿瘤中表现出细胞毒性和抗肿瘤活性。且研究证实骆驼尿液具有抗菌、保肝、抗肿瘤和抗血小板活性等重要作用,极具研究价值。文章主要介绍了骆驼尿液中的有效生物化学成分,并对骆驼尿液在各种疾病中的医药作用进行详细阐述,为今后对骆驼尿液的进一步研究提供理论依据。     

Regression tree analysis of the relationship between the concentrations of antimicrobial components and the microbiota of normal milk from dairy cows

The purpose of this study was to determine the concentrations of antimicrobial components (immunoglobulin A (IgA), lactoferrin (LF), lingual antimicrobial peptide (LAP), and S100A7) in normal milk and their relation to host factors (Age, somatic cell count (SCC), days in milk, richness, and alpha diversity of the milk microbiota) in dairy cows using multivariate regression tree analyses, and to clarify how the milk microbiota is related to the obtained results. Thirty normal milk samples were collected from a commercial dairy farm in June 2020. The thresholds that predicted the concentration of each antimicrobial component in milk were obtained by regression tree analysis, and the beta-diversity of the milk microbiota composition between groups divided according to each threshold was compared by an analysis of similarities test. The IgA and LF concentrations were mainly predicted by the SCC (177,500 and 70,000 cells/ml, respectively), and the LAP and S100A7 concentrations were predicted by Age (29.667 and 40.3 months, respectively). No relationship was observed between the concentration of IgA, LAP, or S100A7 and the milk microbiota composition between the groups divided by the threshold for prediction, but the milk microbiota composition was significantly different between the groups divided by the threshold for predicting the LF concentration. Our results indicated that the LF concentration in normal milk may be associated with the milk microbiota composition.     

Prevalence,Serovars and Antimicrobial Susceptibility of Salmonella spp. from Wild and Domestic Green Iguanas (Iguana iguana) in Grenada,West Indies

Cloacal swabs from 62 green iguanas (Iguana iguana), including 47 wild and 15 domestic ones from five parishes of Grenada, were sampled during a 4‐month period of January to April 2013 and examined by enrichment and selective culture for the presence of Salmonella spp. Fifty‐five per cent of the animals were positive, and eight serovars of Salmonella were isolated. The most common serovar was Rubislaw (58.8%), a serovar found recently in many cane toads in Grenada, followed by Oranienburg (14.7%), a serovar that has been causing serious human disease outbreaks in Japan. Serovar IV:48:g,z₅₁:‐ (formerly, S. Marina) highly invasive and known for serious infections in children in the United States, constituted 11.8% of the isolates, all of them being from domestic green iguanas. Salmonella Newport, a serovar recently found in a blue land crab in Grenada, comprised 11.8% of the isolates from the green iguanas. The remaining four less frequent serovars included S. Javiana and S. Glostrup. Antimicrobial susceptibility tests conducted by a disc diffusion method against amoxicillin–clavulanic acid, ampicillin, cefotaxime, ceftazidime, ciprofloxacin, enrofloxacin, gentamicin, nalidixic acid, streptomycin, tetracycline and trimethoprim–sulfamethoxazole showed that drug resistance is minimal, with intermediate susceptibility, mainly to streptomycin, tetracycline and cefotaxime. This is the first report of isolation and antimicrobial susceptibilities of various Salmonella serovars from wild and domestic green iguanas in Grenada, West Indies.     

益生菌大肠杆菌Nissle 1917抗逆性能、猪肠上皮细胞黏附率及抑菌效果研究

本试验旨在研究益生菌大肠杆菌Nissle 1917(Ec N)抗逆性能、猪肠上皮细胞黏附率及抑菌效果。采用体外法对Ec N进行生长曲线绘制和耐酸、耐胆盐、耐热性能的测定;以猪肠上皮细胞IPEC-J2细胞为体外细胞模型,考察了Ec N对该细胞的黏附率以及对致病菌大肠杆菌K88的黏附抑制率;同时通过蛋白质印迹法检测了Ec N对IPEC-J2细胞β-防御素-2和Toll样受体4的水平的影响。结果表明:1)Ec N对高酸、高胆盐和高温环境具有一定耐受能力。2)Ec N对IPEC-J2细胞的黏附作用以对数期最佳,黏附率达33.96%,显著高于迟缓期、稳定期和衰亡期(P0.05)。3)Ec N对致病菌大肠杆菌K88具有良好的抑制效果,黏附抑制率达87.84%。4)Ec N还能上调IPEC-J2细胞β-防御素-2和Toll样受体4水平。结果提示,益生菌Ec N具有较好的抗逆性能,能够良好地黏附猪肠上皮细胞,对致病菌大肠杆菌K88具有良好的抑制作用。     

3种抗菌药对鸡大肠杆菌病的临床疗效比较

本次试验用从锦州地区郊区某养殖户采集的鸡大肠杆菌病料进行了体外抑菌试验和临床试验,观察了康诺奇、安氟尼和普维欣对大肠杆菌的抑制效果。体外抑菌试验采用的是药敏试验的纸片扩散法,采用两种方法制备菌悬液,2种方法的药敏试验结果均显示康诺奇极敏感、安氟尼高度敏感。选取某养殖户病鸡300只,分为3组,分别用这3种药物进行治疗,并在组内设4个重复,其平均治愈率为康诺奇98.2%、安氟尼96.2%、普维欣92.3%。3种药物中康诺奇的疗效最好,显效快,其他两种药物也有很好的疗效。通过本次试验为锦州地区鸡大肠杆菌病的防治用药提供参考。     

抗菌肽粗提物对肉鸡生长性能、粪便微生物菌群结构及经济效益的影响

为分析抗菌肽粗提物对肉鸡生长性能、粪便微生物菌群结构及经济效益的影响,试验选择体重相近的21日龄白羽肉鸡600只,随机分成4组,每组15个重复,每个重复10只,1组为空白对照组饲喂基础日粮,试验2、3、4组在基础日粮中分别添加1.0％、1.5％、2.0％的抗菌肽粗提物,试验期为21 d.结果表明:(1)试验2、3、4组...     

大肠杆菌胁迫下东北林蛙皮肤抗菌肽分泌特性研究

以东北林蛙(Rana dybowskii)为试验对象,采用大肠杆菌(Escherichia coli)作为环境胁迫因子,通过RP-HPLC分析、抑菌活性和蛋白浓度比较,观察其皮肤分泌物的特异性分泌,以期揭示两栖类动物抵御环境微生物时皮肤分泌抗菌肽的变化规律。研究发现,用E.coli胁迫1~18d后皮肤分泌物粗提物洗脱峰数量明显减少了61.54%~84.62%,对4个持续出现的8、9、11和14号洗脱峰的抑菌活性试验显示,8、9号峰对G-和G+菌均表现较强的活性抑制,而11、14号峰仅对G+菌有较强的抑菌活性。此外,E.coli胁迫后第7天组皮肤分泌物的洗脱峰数量、持续出现峰的峰面积值及蛋白浓度与对照组比均明显增加,第23天组均恢复至较高水平。研究结果表明:两栖类皮肤抗菌肽可能在参与机体先天免疫系统防御和启动后天免疫应答的关键环节中发挥重要的桥梁作用。     

包装顶空气氛和相对湿度对葡萄常温货架期和品质的影响

为分析气调透湿袋和多效抗菌纸对葡萄在常温下的保鲜效果,在室温条件(26℃和相对湿度(RH)70%)下使用PE保鲜袋(PE袋)、自制的透湿性薄膜袋(A袋)以及A袋内加入自制的乙烯吸附复合抗菌纸(A-P)3种被动气调(MA)保鲜方案,并研究包装顶空气氛、顶空相对湿度以及乙烯吸附纸对‘巨峰’葡萄采后贮藏品质的影响。结果表明：A-P组建立的气调气氛(11.5%CO₂、14.5%O₂和RH78%)下‘巨峰’葡萄的果梗褐变率、落粒率和霉变率均最低,可滴定酸含量和可溶性固形物含量水平较高;A袋的顶空气氛(9.17%O₂、25.4%CO₂)抑制葡萄的褐变及霉变较为理想,但是由于相对湿度较高导致落粒;PE袋中较高O₂(18.5%)和较低CO₂(2.2%),特别是高湿度(RH 99%)环境导致葡萄大量霉变与褐变,货架期仅3 d,裸放的CK组3 d时产生大量褐变,失去商业价值。综上,自制抗菌纸与透湿性薄膜的组合有利于葡萄的常温贮藏,延长货架期。A-P包装为葡萄的常温保鲜提供了新...     

玉米应力裂纹率和破碎敏感性的关系

在分析玉米应力裂纹指数（Ｓ）计算方法的基础上,得到了修正应力裂纹指数（Ｓ＾＊）方程,方程中的完善籽粒、单裂籽粒、双裂籽粒、龟裂籽粒的平均权重分别为０．７５、１、１．１８、１．３６。比较了应力裂纹指数和修正应力裂纹指数与破碎敏感性（Ｂ）之间的关系。修正后的应力裂纹指数与破碎敏感性拟合得更好,更反映干后谷物破碎强度的变化。