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为了解马源马链球菌兽疫亚种（S.zooepidemicus）新疆分离株马链球菌兽疫亚种类M蛋白（SzM）基因的分子进化与变异情况,为该菌引起的感染性疾病的防控提供依据,本试验对新疆地区某马场采集的病马淋巴结样品进行病原菌的分离培养和生化鉴定,并对分离菌株进行药物敏感性试验。根据已发表的马源SzM基因序列设计引物,对其SzM基因进行PCR扩增及序列测定。将获得的SzM序列与GenBank中不同动物源马链球菌兽疫亚种分离株序列进行同源性比对和遗传进化分析。结果显示,分离得到了一株革兰氏阳性链球菌,将其命名为马链球菌兽疫亚种ZMSY15-1。药物敏感性试验结果表明,分离菌株对青霉素、磺胺嘧啶钠耐药,对其他14种药物均敏感。序列分析结果显示,马链球菌兽疫亚种ZMSY15-1与国内外不同动物源分离株SzM基因氨基酸同源性为56.0%~70.0%。遗传进化分析结果显示,这些菌株可分为4个群。马链球菌兽疫亚种ZMSY15-1与猪源分离株SzM蛋白的氨基酸同源性为59.9%,分别属于2个不同的群,其与美国马源分离株NH55426亲缘关系最近。本试验结果可丰富国内马源马链球菌兽疫亚种SzM基因的信息数据,为马链球菌兽疫亚种的致病机制研究和预防控制提供参考依据。 相似文献
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为了解马源马链球菌兽疫亚种(S.zooepidemicus)新疆分离株马链球菌兽疫亚种类M蛋白(SzM)基因的分子进化与变异情况,为该菌引起的感染性疾病的防控提供依据,本试验对新疆地区某马场采集的病马淋巴结样品进行病原菌的分离培养和生化鉴定,并对分离菌株进行药物敏感性试验。根据已发表的马源SzM基因序列设计引物,对其SzM基因进行PCR扩增及序列测定。将获得的SzM序列与GenBank中不同动物源马链球菌兽疫亚种分离株序列进行同源性比对和遗传进化分析。结果显示,分离得到了一株革兰氏阳性链球菌,将其命名为马链球菌兽疫亚种ZMSY15-1。药物敏感性试验结果表明,分离菌株对青霉素、磺胺嘧啶钠耐药,对其他14种药物均敏感。序列分析结果显示,马链球菌兽疫亚种ZMSY15-1与国内外不同动物源分离株SzM基因氨基酸同源性为56.0%～70.0%。遗传进化分析结果显示,这些菌株可分为4个群。马链球菌兽疫亚种ZMSY15-1与猪源分离株SzM蛋白的氨基酸同源性为59.9%,分别属于2个不同的群,其与美国马源分离株NH55426亲缘关系最近。本试验结果可丰富国内马源马链球菌兽疫亚种SzM基因的信息数据,为马链球菌兽疫亚种的致病机制研究和预防控制提供参考依据。 相似文献
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为研究马链球菌马亚种FNEB蛋白的免疫保护性,本研究采用PCR方法从马链球菌马亚种新疆分离株中扩增FNEB基因部分片段,克隆于原核表达载体p ET-30a中,转化大肠杆菌BL21(DE3)感受态细胞,以IPTG诱导表达,经SDS-PAGE和western blot分析显示,重组蛋白大小约60 ku,具有良好的抗原性。将纯化的重组蛋白免疫小鼠后,以马链球菌马亚种新疆分离株进行攻毒,结果显示该重组蛋白对免疫组小鼠具有保护力,保护率为65%。本研究克隆了马链球菌马亚种的FNEB截短基因并表达了相应重组蛋白,免疫小鼠后能够提供较好的保护,为重组FNEB蛋白亚单位疫苗的研制奠定基础。 相似文献
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为了解马流产沙门氏菌新疆分离株的分子特征及其鞭毛蛋白FliC基因的结构与功能,本试验运用PCR技术扩增了分离鉴定的2株马流产沙门氏菌新疆株FliC基因,克隆测序并对其进行了生物信息学分析。分析结果显示,成功获得了626 bp的FliC基因(GenBank登录号:KJ486797、KJ486798)。对分离的2株马流产沙门氏菌FliC基因的核苷酸序列同源性分析结果显示,FliC基因新疆分离株与GenBank登录的其他沙门氏菌分离株的核苷酸序列同源性为49.6%～100.0%。该结果表明马流产沙门氏菌的FliC基因在该菌进化和流行的过程中是保守的,本研究将为分析该病的分子流行和进一步利用FliC基因防制该菌引起的感染提供试验基础。 相似文献
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一株羊源链球菌的分离鉴定及溶血素(SLS)基因序列分析 总被引：1，自引：0，他引：1
《中国预防兽医学报》2017,(12)
为分析一株羊源链球菌分离株的部分生物学特性及溶血素(SLS)基因的变异特点,本研究自四川省某绵羊养殖场一只病死绵羊肺脏中分离到一株链球菌并命名为SZ-1,经纯化培养后观察该菌的生长、染色特性,并对其进行16S rRNA基因PCR鉴定、生化鉴定、药物敏感性试验以及SLS基因序列分析。结果显示纯化培养后的细菌于哥伦比亚血琼脂培养基上呈现β溶血;分离菌株16S rRNA基因序列与马链球菌兽疫亚种的同源性在99%以上;药物敏感性试验显示分离株对螺旋霉素、红霉素、萘啶酸、庆大霉素、氯霉素、青霉素、克林霉素敏感,对四环素和卡那霉素耐药;SLS基因与马链球菌兽疫亚种属参考菌株的核苷酸序列相比在第87、291、450位出现了单个碱基的置换,核苷酸同源性为98.77%,SLS基因遗传进化树显示SZ-1与马链球菌兽疫亚种(BHS5、CY、ATCC36524)菌株的亲缘关系最近。综上所述本实验分离株为马链球菌兽疫亚种菌,该研究结果为该菌的临床诊断、选药治疗及其SLS基因的遗传动态变异研究等奠定了基础。 相似文献
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采用 PCR 方法从马腺疫链球菌新疆分离株中扩增 FNE 基因片段,克隆至 pMD19-T 载体。利用分子生物学软件分析测序结果,将 FNE 截短基因亚克隆至原核表达载体 pET-30a 中,转化到大肠埃希菌（E．coli）BL21（DE3）感受态细胞,以 IPTG 诱导 FNE 重组蛋白的表达,用 SDS-PAGE 和 Western blot 法分析蛋白表达及其反应原性。序列分析显示,其与 GenBank 收录的马腺疫链球菌4047（登录号YP002747216）核苷酸序列和氨基酸序列同源性均为99％。采用 PCR 法扩增到675 bp 的 FNE 截短基因片段构建重组表达载体获得重组蛋白,经 SDS-PAGE 分析在46 ku 处出现明显条带,Western blot 分析显示具有反应原性。成功克隆和表达了马腺疫链球菌的 FNE 截短基因,为重组 FNE 蛋白亚单位疫苗的研制奠定了基础。 相似文献
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为分离东北民猪源停乳链球菌(Streptococcus dysgalactiae)并鉴定其生物学特性,从齐齐哈尔市某东北民猪场死亡仔猪的肝脏及其关节液样品中分离病原菌,通过生理生化试验和分子生物学试验鉴定分离菌,研究了分离菌的致病性和药物敏感性。结果表明,分离到革兰阳性球菌1株,生化指标与停乳链球菌停乳亚种相符。系统进化树分析表明,分离菌株与停乳链球菌停乳亚种参考菌株的同源性为97%~98%,其中与AB537921.1(Japan)同源性最高,达到98.99%,进一步从分子水平鉴定该菌为停乳链球菌停乳亚种。以0.2mL/只(3.2×10^9CFU/mL)接种量感染小鼠,发病率和病死率均为100%。分离菌对多黏菌素B、阿莫西林、氨苄西林、环丙沙星、氧氟沙星、庆大霉素、氟苯尼考、林可霉素、新霉素均敏感,仅对罗红霉素耐药。 相似文献
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Rhodococcus equi is an important cause of subacute or chronic abscessating bronchopneumonia of foals up to 3-5 months of age. It shares the lipid-rich cell wall envelope characteristic of the mycolata, including Mycobacterium tuberculosis, as well as the ability of pathogenic members of this group to survive within macrophages. The possession of a large virulence plasmid in isolates recovered from pneumonic foals is crucial for virulence. The plasmid contains an 27 kb pathogenicity island (PI) that encodes seven related virulence-associated proteins (Vaps), including the immunodominant surface-expressed protein, VapA. Only PI genes are differentially expressed when the organism is grown in macrophages in vitro. Ten of the PI genes, including six Vap genes, have signal sequences, suggesting that they are exported from the cell to interact with the macrophage. Different PI genes are regulated by temperature, pH, iron, oxidative stress and probably also by magnesium, all environmental changes encountered after environmental R. equi are inhaled in dust and are ingested into macrophages in the lung. The basis of pathogenicity of R. equi is its ability to multiply in and eventually to destroy alveolar macrophages. Infectivity is largely or exclusively limited to cells of the monocyte-macrophage lineage. Current evidence suggests that infection of foals with virulent R. equi results in some foals in subversion of cell-mediated immunity and development of an ineffective and sometimes lethal Th2-based immune response. Significant progress has been made recently in the development of R. equi-E. coli shuttle vectors, transformation and random and site specific mutagenesis procedures, all of which will be important in molecular dissection of the mechanisms by which R. equi subverts normal macrophage killing mechanisms and cell-mediated immunity. 相似文献
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Katy Webb Colin Barker Tihana Harrison Zoe Heather Karen F. Steward Carl Robinson J. Richard Newton Andrew S. Waller 《Veterinary journal (London, England : 1997)》2013,195(3):300-304
Genome sequencing data for Streptococcus equi subspecies equi and zooepidemicus were used to develop a novel diagnostic triplex quantitative PCR (qPCR) assay targeting two genes specific to S. equi (eqbE and SEQ2190) and a unique 100 base pair control DNA sequence (SZIC) inserted into the SZO07770 pseudogene of S. zooepidemicus strain H70. This triplex strangles qPCR assay can provide results within 2 h of sample receipt, has an overall sensitivity of 93.9% and specificity of 96.6% relative to the eqbE singlex assay and detects S. equi at levels below the threshold of the culture assay, even in the presence of contaminating bacteria. 相似文献
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H. C. Schott II M. M. Esser C. G. Pirie A. P. Pease J. S. Patterson S. M. Reed 《Equine Veterinary Education》2020,32(10):e194-e198
We previously described successful treatment, including surgical drainage, of a Streptococcus equi subspecies equi brain abscess that caused severe neurological deficits in a 7-year-old Quarter Horse mare. This report details the long-term successful outcome of the case, findings of a magnetic resonance imaging (MRI) study performed 14 years after surgery and necropsy findings 18 years after initial treatment. Despite persistent cerebral and midbrain lesions detected by MRI and at necropsy, the mare returned to serviceable function within a year of initial treatment and had a successful performance career for over 10 years until carpal arthritis prompted retirement. This case demonstrates that brain abscess in horses can be successfully managed by combined medical and surgical treatment. 相似文献
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Real-time PCR for detection and differentiation of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus 总被引：1，自引：0，他引：1
Strangles is a contagious equine disease caused by Streptococcus equi subsp. equi. In this study, clinical strains of S. equi (n=24) and Streptococcus equi subsp. zooepidemicus (n=24) were genetically characterized by sequencing of the 16S rRNA and sodA genes in order to devise a real-time PCR system that can detect S. equi and S. zooepidemicus and distinguish between them. Sequencing demonstrated that all S. equi strains had the same 16S rRNA sequence, whereas S. zooepidemicus strains could be divided into subgroups. One of these (n=12 strains) had 16S rRNA sequences almost identical with the S. equi strains. Interestingly, four of the strains biochemically identified as S. zooepidemicus were found by sequencing of the 16S rRNA gene to have a sequence homologous with Streptococcus equi subsp. ruminatorum. However, they did not have the colony appearance or the biochemical characteristics of the type strain of S. ruminatorum. Classification of S. ruminatorum may thus not be determined solely by 16S rRNA sequencing. Sequencing of the sodA gene demonstrated that all S. equi strains had an identical sequence. For the S. zooepidemicus strains minor differences were found between the sodA sequences. The developed real-time PCR, based on the sodA and seeI genes was compared with conventional culturing on 103 cultured samples from horses with suspected strangles or other upper respiratory disease. The real-time PCR system was found to be more sensitive than conventional cultivation as two additional field isolates of S. equi and four of S. zooepidemicus were detected. 相似文献
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Ecology of Rhodococcus equi 总被引：7，自引：0，他引：7
A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on horses, sheep and cattle, but only horses reacted significantly. The physiological characteristics of R. equi and the nature of its distribution in the environment suggested that R. equi is a soil organism. 相似文献
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