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1.
猪传染性胸膜肺炎放线杆菌"菌影"的制备   总被引：3，自引：2，他引：3  
本试验通过PCR扩增噬菌体PhiX174 的裂解基因E,将该基因连接到含有入PL/PR-cI857启动阻遏系统的pBV220 栽体中,从而使裂解基因E和启动阻遏系统入PL/PR-cI857串联成为温度敏感的裂解盒,构建重组质粒pBV-E.再将含有E基因的裂解盒插入到App-E.coli穿梭载体pGZRS-18中,构建胸膜肺炎放线杆菌打孔质粒.采用电击穿孔法将其转入胸膜肺炎放线杆菌中,含有打孔质粒的胸膜肺炎放线杆菌在28℃条件下生长到对数生长期,升温42℃诱导E基因的表达,制备了胸膜肺炎放线杆菌菌影.电镜观察菌影形态完整,内容物全部被释放到胞外.本试验为进一步研究菌影这一新型菌苗及佐剂奠定了基础.  相似文献   

2.
为制备高裂解效率的致禽肾脏、肠道病变大肠杆菌菌影,本研究通过编码15个柔性氨基酸linker采用融合PCR法将噬菌体中Φ174的裂解蛋白E基因和金黄色葡萄球菌核酸酶A基因(SN)串联(E-15L-SN),插入温控表达质粒pBV220,构建重组温控双裂解表达质粒(pBV-ES),采用PCR扩增其温控双基因裂解表达盒(DLS-ES)插入E.coli-Pasteurella(大肠杆菌和巴氏杆菌)穿梭质粒pBA1100,构建重组温控双基因裂解穿梭质粒pBA1100-DLS-ES。该质粒可以通过温控制备高裂解率的E.coli和Pasteurella两种菌的菌影。本实验将构建的pBA1100-DLS-ES电转化至致禽肾脏、肠道病变E.coli中,28℃集菌,42℃温控诱导裂解蛋白E和核酸酶A表达。OD_(600nm)值及电镜结果表明,双基因裂解率高于单基因,同时收集菌影时间也比单基因裂解短,42℃诱导2 h含双裂解基因的菌液处理菌体裂解率达到99.9999%,本实验利用菌影形成机制将含青霉素抗性的致禽肾脏、肠道病变E.coli制备成菌影,为新型菌影疫苗的制备提供实验依据。  相似文献   

3.
菌壳技术是一种新型的灭活疫苗制备方法,通过非变性的灭活方式保存细菌表面多个抗原表位,所制备的菌壳可作为预防细菌病的理想疫苗。本试验从噬菌体PhiX174 DNA钓取裂解E基因,连接至温控原核表达载体pBV220,通过PCR在所构建的pBV220+E上扩增出蛋白裂解部件（protein lysis component,PLC）,该部件包含阻遏蛋白cI857、溶菌E基因及终止序列rrnbT1T2,然后将其克隆至广宿主表达载体pBBR1MCS-2中,最终将构建的广宿主裂解质粒pBBR+PLC电转入犬布鲁氏菌RM6/66中。试验结果表明,经42 ℃诱导后,广宿主裂解质粒对犬布鲁氏菌RM6/66的裂解率达100%,成功制备了犬布鲁氏菌RM6/66菌壳疫苗。本试验通过菌壳技术制备的犬布鲁氏菌疫苗对预防宠物犬布鲁氏菌病起到重要作用,同时也对人兽布鲁氏菌疫苗的研制提供新策略。  相似文献   

4.
制备牛源大肠杆菌菌影,为其作为疫苗及载体奠定基础。将裂解质粒PHH43-E电转入牛大肠杆菌中,并通过温度的改变诱导细菌裂解,即其在37℃条件下生长到对数生长期,然后进行42℃升温诱导。经温控诱导裂解质粒表达后可将细胞壁裂解,形成细菌空壳,成功制备了菌影。  相似文献   

5.
维氏气单胞菌菌影疫苗的构建及其溶菌动力学研究   总被引：1，自引：0，他引：1  
细菌菌影(Bacterial ghosts)是通过诱导PhiX 174噬菌体中裂解基因E在革兰氏阴性菌中的表达所获得的无细胞内容物的空细菌体.它保持了与活菌相同的膜蛋白成分、天然结构、细胞表面抗原等特性,是一种新型的死菌疫苗.为优化维氏气单胞菌(A.veronii)菌影制备条件,本实验将带有庆大抗性的裂解基因E转入A.veroniiATCC35624株中,通过温度变化对其进行溶菌动力学试验,每隔30 min对菌液OD600nm及其活菌数进行测定,当OD600nm稳定不再下降时,通过扫描电镜观察裂解后菌体的形态变化.结果显示,在诱导30 min后OD600nm值开始持续下降,当其下降到最低值时,活菌检测结果表明几乎无活菌存在.本研究利用菌影形成机制构建A.veronii菌影,为新型疫苗的制备提供依据.  相似文献   

6.
副猪嗜血杆菌(Haemophilus parasuis)RfaF基因编码脂多糖庚糖基转移酶Ⅱ,参与了细菌的黏附入侵和抗血清中补体杀菌作用.为了进一步研究庚糖基转移酶Ⅱ的功能,用原核表达系统表达H.parasuis RfaF基因.用特异性引物扩增H.parasuis SC096株血清4型RfaF基因,得到一条1 053 bp的片段,将其连接到pET-32a(+)载体上,构建重组表达质粒,并将其转化至DH5α感受态细胞中,经酶切、PCR和测序进行鉴定.测序正确后,提取重组质粒,转化至E.coli BL21 (DE3)感受态细胞中,并用IPTG进行诱导.将诱导产物进行SDS-PAGE和Western blot分析.结果显示,H.parasuis RfaF基因可以在E.coli中表达,重组蛋白分子质量约为55 ku,与预期分子质量大小一致.Western blot分析表明,RfaF蛋白可以与H.parasuis血清4.型阳性高免血清产生特异性结合反应,具有良好的抗原性.本研究结果为深入探讨RafF基因的功能奠定了基础.  相似文献   

7.
采用PCR方法从噬菌体PhiX174基因组中扩增出裂解蛋白E基因,从金黄色葡萄球菌基因组中扩增出核酸酶A基因（SN）,通过15个柔性氨基酸linker将双基因串联,插入PBV220表达载体,构建温控双基因裂解系统（DLS）。PCR扩增DLS,将其与E.coli-App穿梭载体pMC-Express相连,构建重组穿梭载体pMC-WK。裂解试验表明,E-15aalinker-SN裂解较E裂解迅速而彻底,菌体裂解率达到99.999 4%;经PCR扩增出的DLS具有裂解活性。本试验成功构建了温控双基因裂解载体pMC-WK,为App菌影疫苗的研究奠定了基础。  相似文献   

8.
将含有裂解酶基因重组温控裂解质粒pBBR1MCS：：PR-PL-E电转化至粗糙型布鲁菌M111中，构建重组布鲁菌M111（pBBRlMCS：：PR-PL-E）。重组菌株在28℃培养，42℃诱导表达裂解酶E，从而制备布鲁菌菌壳。绘制布鲁菌生长曲线及裂解曲线，计算裂解率并用透射电镜观察布鲁菌菌壳的形态。结果显示，成功制备了布鲁菌菌壳，温控裂解质粒pBBRIMCS：：PR-PL-E对布鲁菌的裂解率为100％。透射电镜观察可见细菌内容物部分流出，细菌表面出现不同程度的皱缩，细胞形态发生变化。结果表明，本试验成功制备了粗糙型布鲁菌菌壳，初步研究了其基本特性，为下-步开展布鲁菌菌壳疫苗的研究奠定了基础。  相似文献   

9.
为制备仔猪水肿病源致病性大肠杆菌菌蜕,本实验克隆phiX174裂解基因E,构建温控溶菌表达载体,将其转入猪源致病性大肠杆菌JLBC1501中,制备菌蜕计算其裂解率,并用电镜进行观察。结果显示:扩增出片段大小为274bp的裂解基因E,成功构建温控溶菌质粒载体pBVE,制备了猪源致病性大肠杆菌菌蜕,其裂解率最高为99.72%,扫描电镜观察,菌蜕株内容物大量排出、细菌发生明显皱缩。研究结果为仔猪水肿病的防治奠定了基础。  相似文献   

10.
为制备猪霍乱沙门菌菌蜕并研究其免疫保护力,本实验克隆噬菌体phiX174裂解基因E,与pBV220连接,构建温控溶菌表达载体,将该载体转入猪霍乱沙门菌TTB1中,制备菌蜕并对其裂解率、安全性以及对小鼠的免疫保护力进行了研究。结果显示：成果克隆了裂解基因E、片段大小274bp,构建了温控溶菌质粒载体pBVE,制备了猪霍乱沙门菌菌蜕,其裂解率最高为99.46%、经冻干灭活残余活菌,安全性试验检测证实其安全后,对小鼠进行了免疫保护试验,其保护率为70%、与弗氏佐剂灭活苗保护率相当、优于甲醛灭活苗。研究结果为猪霍乱沙门菌引发疾病的防治奠定了基础。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
  相似文献   

17.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

18.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

19.
正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in  相似文献   

20.
Tropical Animal Health and Production -  相似文献   

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