Staphylococcus aureus (SA) is representative of gram-positive bacteria. Sanguinarine chloride hydrate (SGCH) is the hydrochloride form of sanguinarine (SG), one of the main extracts of Macleaya cordata (M. cordata). There are few reports on its antibacterial mechanism against SA. Therefore, in this study, we investigated the in vitro antibacterial activity and mechanism of SGCH against SA. The inhibitory zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were measured, and the bactericidal activity curve was plotted. In addition, the micromorphology, alkaline phosphatase (AKP) activity, Na+K+, Ca2+Mg2+-adenosine triphosphate (ATP) activity, intracellular reactive oxygen species (ROS), and fluorescein diacetate (FDA) were observed and detected. The results showed that the inhibitory zone of SGCH against SA was judged as medium-sensitive; the MIC and MBC were 128 and 256 μg/mL, respectively; in the bactericidal activity curve, SGCH with 8 × MIC could completely kill SA within 24 h. SGCH was able to interfere with the integrity and permeability of the SA cell wall and membrane, as confirmed by the scanning electron microscopy (SEM) images, the increase in extracellular AKP and Na+ K+, Ca2+ Mg2+-ATP activities as well as the fluorescein diacetate (FDA) staining experiment results. Moreover, a high concentration of SGCH could induce SA to produce large amounts of ROS. In summary, these findings revealed that SGCH has a preferable antibacterial effect on SA, providing an experimental and theoretical basis for using SG as an antibiotic substitute in animal husbandry and for the clinical control and treatment of diseases caused by SA.

为了解永善县云南半细毛羊的弓形虫感染情况,利用弓形虫间接血凝试验(IHA)检测205份云南半细毛羊血清弓形虫抗体.结果显示:92份血清阳性,总阳性率为44.9％,其中雄性和雌性羊血清阳性率分别为50.0％、43.8％,不同性别云南半细毛羊弓形虫抗体阳性率差异不显著(P>0.05);年龄小于12月龄的羊血清样品阳性率为47.0％,12月龄以上的羊血清样品阳性率为35.1％,不同年龄云南半细毛羊弓形虫抗体阳性率差异不显著(P>0.05).该地区半细毛羊弓形虫感染率较高,需要加强防治.

为了解云南鸽子血变原虫的感染情况,对采自玉溪地区的324只鸽子血样用套式PCR方法对线粒体细胞色素b(cytochrome b,cytb)基因进行扩增,经测序比对分析,结果检出12份阳性样本,阳性率为3.70％;获得的序列与GenBank上公布的鸽血变原虫序列相似性达98％以上,运用MEGA6.0构建系统发育进化树,发现与鸽血变原虫虫株位于同一进化支.该调查结果为云南玉溪鸽子血变原虫的防控提供了数据支撑.

利用口蹄疫病毒(Foot and mouth disease virus type O,FMDV-O)VP1 特异性蛋白为抗原,杂交瘤细胞 7E3分泌单克隆抗体,建立一种检测FMDV-O型的阻断酶联免疫吸附试验(Enzyme-linked immunosorbent assay,ELISA)方法.对ELISA反应条件进行优化:抗原包被浓度为 48.4 g/mL,单抗稀释度为 28.0 g/mL,羊抗鼠酶标二抗(Sheep anti-mouse enzyme-conjugate secondary antibody,IgG-HRP)最佳稀释度为 1 g/mL,底物液反应时间为 37℃避光显色 15 min.ELISA结果的判定标准为:血清阴断率＜57％判为阳性,血清阻断率≥57％判为阴性.本研究建立的ELISA方法能与FMDV-O型阳性血清进行特异性反应,而与水泡性口炎病毒(Vesicular stomatitis virus,VSV),口蹄疫亚洲I型病毒(Foot and Mouth Disease virus type Asia1,FMDV-Asia1),羊痘病病毒(Sheep pox virus,QRF),口蹄疫A型病毒(Foot and mouth disease virus type A,FMDV-A),蓝舌病病毒(Bluetongue virus,BTV),小反刍兽疫病毒(peste des petits ruminants virus,PPRV),赤羽病病毒(Akabane virus,AKV)的阳性血清无交叉反应性.ELISA的重复性试验表明,批间和批内的变异系数均小于10％.比较试验结果表明,该ELISA的相对敏感性和特异性分别为88.9％和 100％,与金迈诗口蹄疫O型液相阻断ELISA抗体检测试剂盒的符合率为 93.75％.综上所述,本试验建立的口蹄疫病毒O型阻断ELISA抗体方法具有特异、稳定、灵敏的优点,为建立标准化的检测试剂盒奠定了基础.

本文主要介绍了生物安全三级实验室的特征及其在传染病防控中的作用.生物安全三级实验室具备的"盒中盒"结构、负压环境、高效过滤排风装置、关键防护设备等,将传染病病原体与环境隔离,避免在从事传染病研究时传播给人、动物以及环境.生物安全三级实验室利用其防护水平在传染病疫苗研制、传染病检验检疫及传染病药物筛选等方面发挥重要作用,是防控和治疗传染病的有效平台.

Porcine reproductive and respiratory syndrome (PRRS) is caused by the PRRS virus (PRRSV), and it is a widespread disease that severely affects swine production in all age groups. Detection of PRRSV antibody levels in pig farms is beneficial for immunity evaluations. In this study, a total of 1,206 serum samples of breeding boars, breeding sows, reserve pigs and commercial pigs from 16 large-scale swine farms in 4 different regions of Yunnan province in China were collected during 2019 and detected by indirect enzyme-linked immunosorbent assay (ELISA). The results showed that the average positive rate of PRRSV antibody was 88.32%, among which the antibody-positive rates were 89.03%, 89.18%, 92.11%, and 82.95% in East Yunnan (E. Yunnan), Central Yunnan (Cent. Yunnan), Northwest Yunnan (N.W. Yunnan) and Northeast Yunnan (N.E. Yunnan), respectively (P > 0.05). For the different pig categories, the reserve pigs (93.51%) showed much higher antibody-positive rates, followed by breeding sows (92.44%), commercial pigs (87.34%) and breeding boars (85.62%). Statistical analysis revealed that the rates were significantly different among different pig categories (P <0.05). These s results indicated that pig categories were significantly associated with PRRSV antibody levels in this study. All the positive rates in this study fulfilled the requirement of ≥ 70% set by the National Animal Disease Surveillance Plan of China (2011). The study could provide evidence of the antibody response of PRRSV at the farm level.

蓝舌病(bluetongue,BT)是由蓝舌病病毒(bluetongue virus,BTV)引起的一种烈性传染病,主要通过易感动物移动、易感动物聚集、病毒基因重配以及强大的传播媒介等4个因素在全球长时期传播流行.自20世纪初发现BT以来,BT持续在全球流行,欧洲是重灾区;BTV血清型复杂,全球各大洲均有多种血清型分布流行,目前已陆续鉴定出29个BTV血清型.进入21世纪后,受全球气候变暖、畜产品贸易等因素影响,BT全球流行范围继续扩大.面对严峻的BT流行形势,需要采取加强进出口检疫和易感动物流动监管,建设无规定动物疫病生物安全隔离区,以及实施有效的预防接种制度等综合措施.

2006年8月荷兰暴发的蓝舌病8型(BTV-8)疫情已蔓延至欧洲大陆,而国内目前尚未发现BTV-8感染的报道.为评估BTV-8传入国内的风险,采用定性评估方法,通过收集BTV-8疫源地国家的疫情信息数据,结合其病原学特征、传播媒介、分布及流行情况、传染源、传播途径和易感动物等方面的研究内容进行传入风险分析.鉴于我国与欧洲BTV-8疫源地各国的畜产品贸易以及活动物、精液和胚胎交易频繁,贸易数量巨大,而且BTV-8还可以通过家养动物与野生动物接触以及库蠓等媒介传播,综合分析认为BTV-8传入国内的风险较高.建议加强边境口岸检验检疫,以及牛羊等反刍动物及库蠓的BTV-8监测,防范BTV-8传入国内,并做到传入时早发现、早控制.

本文对流行性出血病的病原、流行病学、疫苗等的研究进展进行概述,以期为探索特异性强、灵敏度高、高效经济的诊断方法和开发疫苗研究提供参考.

为了解大理州奶牛肠道寄生虫的感染情况,制定出有效的防治措施,从大理州巍山、洱源、宾川等地采集奶牛新鲜粪样共计241份,采用饱和食盐水漂浮法及水洗沉淀法进行检测.结果 显示:样品总阳性率为32.0％,其中线虫卵阳性率为20.3％,绦虫卵阳性率为1.24％,吸虫卵阳性率为3.73％,球虫卵囊阳性率为15.8％,混合感染率为7.88％;从不同地理位置来看,巍山奶牛未检出,洱源奶牛检出率为35.6％,宾川奶牛检出率为41.8％.大理州部分地区奶牛寄生虫感染情况比较严重,且存在混合感染,需加强防治.

为了针对不同实际检测情况选择出合适的口蹄疫检测方法,本文从抗原和抗体检测两方面,并结合OIE手册和中国国家标准(GB/T 18935-2018),总结了13种检测方法的优缺点.不同检测方法在灵敏度、准确度、稳定性、专一性、经济性、时效性以及操作难易度等方面各有不同.

为研制流行性出血病病毒(epidemic hemorrhagic disease virus,EHDV)ELISA抗体检测试剂盒,用饱和硫酸铵浓缩EHDV灭活病毒作为包被抗原,以EHDV鼠源单克隆抗体作为阻断抗体,商品化的IgG-HRP羊抗鼠二抗作为检测抗体,通过优化检测试剂中各组分含量和反应程序,建立了一种EHDV阻断ELISA抗体检测方法.用研制的试剂盒与ID Screen参考试剂盒分别检测实验室保存的血清样本,结果发现该方法的特异性、敏感性与ID Screen参考试剂盒一致,二者符合率为97.00％.结果表明,研制的EHDV阻断ELISA抗体检测试剂盒可作为EHDV抗体检测的候选试剂盒,代替国外试剂盒使用,从而降低EHDV检测成本,这对该病防控具有重要意义.

为明确云南地区部分养鸡场住白细胞虫的流行情况,试验采用巢式PCR方法对970份鸡血样扩增住白细胞虫的线粒体细胞色素b基因(cytb).结果显示:34份样本为住白细胞虫阳性,阳性检出率为3.51％(34/970);同源性分析表明,阳性样本均为卡氏住白细胞虫(Leucocytozoon caulleryi).对阳性样本进行不同性别、日龄、品种和地区等因素比对分析,发现地理区域、日龄、品种间的阳性率均存在极显著相关性(P＜0.001),而性别间无显著相关性(P＞0.05).本试验结果可为云南养鸡场住白细胞虫病的防治提供参考.

为鉴定伯恩山犬感染的眼线虫种属关系,采用PCR扩增虫体线粒体细胞色素C氧化酶第1亚基(cox 1)基因.将有效序列进行NCBI-BLAST在线比对,利用MEGA6.0构建遗传系统进化树.结果显示,伯恩山犬眼线虫cox 1序列长度为446 bp,与结膜吸吮线虫同源性达99％,系统进化分析显示二者位于同一分支,由此确定,伯恩山犬感染的线虫为结膜吸吮线虫.

[目的]为调查云岭牛肠道寄生虫的感染情况,以其提供有效的防治措施.[方法]从小哨云岭牛核心育种场和楚雄锦达牧业扩繁场采集382份新鲜粪便样品,采用饱和盐水漂浮法和自然沉淀法检测寄生虫感染情况.[结果]共检测出89份样品存在寄生虫感染,平均感染率为23.30％.分别检出了线虫、球虫和吸虫的感染,其感染率分别为17.28％、7.07％、0.26％,混合感染率为1.31％.云岭牛核心育种场寄生虫感染率为31.25％,楚雄锦达牧业扩繁场为15.26％;自由放牧云岭牛寄生虫感染率为36.05％,圈养云岭牛为19.59％;不同养殖场、不同养殖方式的云岭牛之间寄生虫感染存在极显著差异(P＜0.01),而不同性别和年龄的云岭牛之间无显著性差异(P＞0.05).[结论]云岭牛寄生线虫感染较为突出,应加强综合防治以促进肉牛养殖业的健康可持续发展.

Blastocystis is an enteral eukaryote with an omnipresent existence in animals and humans globally. Animals have been proposed to be a major reservoir for the transmission of Blastocystis to individuals due to their high prevalence and large amount of zoonotic subtypes. However, limited data on Blastocystis infection in experimental macaques in China exists. The objective of the current study was to investigate the frequency and subtypes of Blastocystis infection in macaques in southwestern China. A total of 505 fecal samples were collected from experimental macaques in Yunnan province and were analyzed by nested PCR and phylogenetic analyses on the basis of small subunit rRNA (SSU rRNA) gene fragments. A total of 235 specimens were positive for Blastocystis sp., and the prevalence of Blastocystis sp. was 46.5% (235/505). Significant differences in prevalence were also observed among the various species of macaques (P < 0.0133, df = 2, χ2 = 8.64) and the different feed types (P < 0.0093, df = 1, χ2 = 6.77). Moreover, three zoonotic subtypes, ST1, ST3, and ST5, were identified by DNA sequence analysis. There were mainly single subtype infections with some mixed subtype infections, and the predominant subtype was ST3. The results suggested a high prevalence and diversified subtypes in macaques in Yunnan province, southwestern China. Macaques are likely to be potential reservoirs capable of zoonotic transmission of Blastocystis sp. to humans. To our knowledge, this study is the first large-scale systematic analysis of Blastocystis sp. colonization in Yunnan province in the subtropics of China; these results contribute to the in-depth study of genetic characteristics and the prevention, control, and treatment of Blastocystis sp. in macaques in Yunnan province and other regions.

为了解玉溪地区鸽子弓形虫的感染情况,为鸽子弓形虫病的防控提供参考.本文运用IHA和巢式PCR两种检测方法,对采自玉溪地区的207份鸽子血液样品进行抗体和抗原的检测.结果显示,IHA检测的血清阳性率为6.28％,巢式PCR检测的阳性率为7.69％;从年龄分析,成年鸽(3.23％)和幼年鸽(6.28％)的血清阳性率之间无显著差异(=0.470>0.05).结果表明,该地鸽子存在弓形虫感染,但IHA检测结果仅能为弓形虫病血清学检测提供参考依据,并不能完全确定被检鸽子是否携带弓形虫病原体.将两种检测方法结合使用能更准确地掌握鸽子弓形虫的感染情况.