首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 484 毫秒
1.
根据巴氏杆菌磺胺耐药基因Sul Ⅱ序列设计引物，以临床分离的禽源巴氏杆菌磺胺耐药菌株为模板，扩增出禽源巴氏杆菌Sul Ⅱ的全长基因序列。经T载体克隆和核苷酸序列测定，克隆的Sul Ⅱ基因与文献报道的同源性为98．9%，有9个碱基的差异，但所编码的氨基酸没有改变。将Sul Ⅱ基因按正向的阅读框架与表达戴体pET-28c( )连接，重组质粒经酶切鉴定正确后，经IPTG诱导，SDS-PAGE检测，融合蛋白的表达产物占菌体总蛋白的11％，蛋白表达形式为包涵体表达。  相似文献   

2.
根据GenBank中发表的巴氏杆菌质粒上的磺胺类药耐药基因SulⅡ和链霉素耐药基因StrA的序列设计2对引物,以临床分离的对磺胺甲唑和链霉素耐药的8株卡氏杆菌为模板,扩增SulⅡ基因和StrA基因,然后将纯化的PCR产物进行克隆并作核苷酸序列测定,把测得的克隆基因序列与巴氏杆菌科其它属细菌耐药质粒上存在的Sul Ⅱ基因和StrA基因序列(A1514834)进行比较,结果显示它们之间具有很高的同源性(≥99,6%).试验结果表明,卡氏杆菌的质粒上存在耐药基因Sul Ⅱ和Str A,其对磺胺甲嗯唑和链霉素的耐药性可能与Sul Ⅱ基因和Str A基因的存在密切相关.  相似文献   

3.
为鉴定禽源多杀性巴氏杆菌(Pm)链霉素(Str)敏感株与耐药株(MIC=1024μg/mL)在转录组水平上的差异,本研究采用RNA-seq技术对Str敏感株与耐药株进行双向测序,筛选得到差异表达基因,通过GO、KEGG和ARDB数据库对差异表达基因进行分组和富集性分析,并利用荧光定量PCR对筛选出的差异表达基因进行验证。结果显示,共筛选获得625个差异表达基因,其中包括581个上调基因和44个下调基因。通过GO功能富集分析显示差异表达基因多数发挥细胞膜转运功能;对差异表达基因进行信号通路富集性分析显示,大多数差异表达基因分布在ABC转运蛋白与双组分系统代谢途径中;采用ARDB对差异表达基因进行耐药基因分析,显示其中的耐药基因主要为氨基糖苷转移酶类和外排系统两类。本研究结果表明,禽源Pm对Str的耐药机制可能与细胞膜上多药外排泵的过量表达和氨基糖苷转移酶类灭活抗菌药物有关。同时,也为进一步研究禽源Pm对Str的耐药机制奠定了基础。  相似文献   

4.
巴氏杆菌对链霉素和磺胺耐药机制的研究   总被引：1，自引：0，他引：1  
根据巴氏杆菌的链霉素耐药基因StrA和磺胺耐药基因SulⅡ序列设计2对引物,以临床分离的4株禽源巴氏杆菌耐药株为模板,扩增出StrA、SulⅡ基因序列。经克隆和核苷酸序列测定,克隆的基因与文献报道的耐药基因序列(NC-001774)有较高的同源性(≥98.9%);试验结果显示,耐药株巴氏杆菌对链霉素和磺胺耐药性的差异与StrA、SulⅡ基因突变有关(耐药性高的菌株基因突变率高)。试验中所有耐药菌均在StrA基因编码的第204位氨基酸处存在突变;所有耐药菌均在SulⅡ基因编码的第159,246,384,584,590,591,597,582位氨基酸处存在突变,上述突变基因可能是导致巴氏杆菌对链霉素和磺胺产生耐药性的主要因素。  相似文献   

5.
《畜牧与兽医》2015,(10):79-82
为获得副猪嗜血杆菌(HPS)外膜蛋白中的穿孔素前体蛋白P2(Omp P2)基因的表达产物,利用特异性引物以HPS血清13型江西分离株扩增omp P2基因,并将其克隆到p MD18-T载体中进行序列测定和分析。结果表明:omp P2全基因含一个1 092 bp的开放阅读框,编码一个含363个氨基酸的蛋白,与所报道的HPS omp P2基因(登录号:HM172029.1)的同源性为100%。再将其亚克隆于原核表达载体p ET-32a(+)中构建重组表达质粒p ET-32a(+)-omp P2。后转化至受体菌大肠杆菌BL21(DE3),进行IPTG诱导。经SDS-PAGE检测,表达的重组蛋白分子质量与预期的58 ku一致。Western blot分析表明,表达产物与HPS阳性血清能发生反应,显示表达产物具有良好的反应活性。  相似文献   

6.
  相似文献   

7.
为了研究S100A4蛋白在鹿茸发生过程中的生物学功能,构建长白山梅花鹿鹿茸S100A4基因原核表达载体,并进行BL21原核表达;自鹿茸骨膜中提取总RNA,逆转录成c DNA,以特异性引物扩增S100A4,扩增产物克隆到p MD18-T载体并测序鉴定,将目的片段和原核表达质粒p ET-15b分别用Bam H I和HindⅢ双酶切并连接,再将重组质粒转入BL21用TPIG进行诱导表达;结果通过序列的对比分析,S100A4基因是一个相对保守的基因,与多个物种的匹配度达到90%,与牛S100A4基因同源性最高,达到98.4%;成功构建了p ET15b-S100A4表达质粒,转化BL21诱导表达后,SDS-PAGE电泳检测显示表达的蛋白分子量为11 k D,与预期一致。表明梅花鹿鹿茸干细胞S100A4基因的可以在原核中克隆、分析和表达,为真核表达和进一步的蛋白功能分析奠定了基础。  相似文献   

8.
试验对多杀性巴氏杆菌外膜蛋白H(OmpH)基因进行克隆、鉴定,并在原核系统中表达。以多杀性巴氏杆菌(CVCC448)强毒株基因组为模板,扩增OmpH基因,连接T载体,经测序鉴定正确后与表达载体pET-28a连接构建重组表达质粒OmpH-pET28a,将此重组质粒转化入表达宿主E.coli BL21菌株内,抽提质粒,酶切鉴定正确后对转化菌株以IPTG进行诱导,表达产物通过镍离子亲和层析纯化,之后进行SDS-PAGE和Western blotting分析。结果显示,OmpH基因的编码区为978 bp,编码326 个氨基酸残基,融合蛋白分子质量约为37 ku。Western blotting检测结果显示,表达的重组蛋白OmpH可与鼠抗多杀性巴氏杆菌全菌体多抗血清反应得到清晰的目的条带,表明表达的重组蛋白具有良好的免疫原性。多杀性巴氏杆菌OmpH基因的成功表达,为进一步研究其免疫作用奠定了基础。  相似文献   

9.
为了给原核表达牛分枝杆菌Fix B、Hsp X和MPB83基因并纯化Fix B、Hsp X和MPB83蛋白,进一步研究它们在牛结核病诊断中作为特异性抗原的诊断价值及应用奠定基础,试验用PCR方法从牛结核分枝杆菌AF2122/97基因组中扩增出Fix B、Hsp X和MPB83基因片段,构建p ET-28a-Fix B、p ET-28a-Hsp X和p ET-28a-MPB83重组质粒,克隆到DH5ɑ感受态细胞,提取测序正确的阳性重组质粒,转化BL21(DE3)感受态细胞,用1 mmol/L IPTG于37℃诱导表达,SDS-PAGE分析目的蛋白的表达形式,Western-blot分析鉴定并用Ni-NTA层析柱纯化蛋白。结果表明:成功扩增了大小依次约为957 bp、435 bp和663 bp的Fix B、Hsp X和MPB83基因,将其连接p ET-28a原核表达载体,原核表达的Fix B、Hsp X和MPB83重组蛋白均以包涵体形式存在,分子质量依次约为37 ku、21 ku和28 ku。经Western-blot鉴定表达产物为Fix B、Hsp X和MPB83重组蛋白,Ni-NTA成功洗脱出目的蛋白。说明试验成功构建了牛分枝杆菌Fix B、Hsp X和MPB83基因的原核表达载体,并纯化了Fix B、Hsp X和MPB83重组蛋白,可用于进一步的应用研究。  相似文献   

10.
猪源多杀性巴氏杆菌ompH基因的克隆、表达   总被引：7，自引：0，他引：7  
利用已分离的菌株030224HB，根据NCBI上的序列(U52208)设计了一对引物，用PCR方法扩增了猪源多杀性巴氏杆菌的外膜蛋白基因(ompH)，扩增的片段大小为1114bp(ORF为960bp)，并克隆到载体pMD18-T(T-Vector)，测序表明该基因相当保守。用pET-28b构建了原核表达载体pET28b-ompH，转化BL21并诱导表达，SDS-PAGE结果显示表达蛋白约为35ku，与报道大小相近。Western-blot结果表明表达的蛋白质具有生物学活性，然后用所表达的蛋白做了ELISA检测方法的初步探讨。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

14.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

15.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

16.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

17.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

18.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

19.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

20.
Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号