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致病性鸡大肠杆菌typel菌毛fimC基因的克隆与序列测序 总被引：1，自引：0，他引：1
根据国外发表的人致病性大肠杆菌fimC基因序列,在其保守区设计了带有BamHⅠ/HindⅢ酶切位点的一对引物,应用PCR技术以鸡致病性大肠杆菌02基因组DNA为模板扩增到一个片段,大小约为700kp,将扩增产物克隆到pMD18-T载体上,并转化于大肠杆菌TG1宿主菌,经酶切和筛选,得到阳性重组质粒。通过对阳性重组质粒核酸序列测定,确定此DNA片段为鸡大肠杆菌fimC基因。 相似文献
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在表达鸡致病性大肠杆菌菌毛fimC基因的基础上,对fimC蛋白卵黄抗体的免疫保护效力进行测定。对鸡致病性大肠杆菌O2血清型菌株fimC基因序列进行扩增,扩增产物克隆至pMD18-T载体并测序。测序结果显示,fimC基因全长657 bp,编码218个氨基酸,与人源大肠杆菌fimC基因进行同源性比较,核苷酸序列同源性达97.9%,氨基酸序同源性为96%。从重组质粒pMD18-T-fimC上将fimC基因亚克隆到表达载体质粒pET-30c上,转化大肠杆菌BL21（DE3）,表达出预期的25 ku融合蛋白,采用Western Blot对表达产物进行反应原性分析,结果显示fimC融合蛋白具有较好的抗原反应特异性。用表达的fimC蛋白免疫产蛋母鸡,制备fimC高免卵黄抗体。用制备的fimC高免卵黄抗体免疫1日龄健康雏鸡,1 d后注射鸡致病性大肠杆菌进行攻毒,结果显示,fimC卵黄抗体免疫组死亡率为40%,对照组分别为60%、70%,证明所制备的fimC蛋白卵黄抗体能在一定程度上抵抗鸡致病性大肠杆菌的攻击。 相似文献
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鸡致病性大肠杆菌fimC基因缺失菌株的构建及生物学特性鉴定 总被引：1，自引：1，他引：0
本研究目的是研究fimC基因的功能。基于致病性大肠杆菌（APEC）Ⅰ型菌毛fimC基因的已知序列,通过PCR扩增了缺失169 bp的fimC基因片段,将其克隆到自杀载体pCVD442中,通过接合性转导将重组自杀性质粒pCVD442∷△fimC从大肠杆菌SM10λpir转到O2（Nal^R）中。根据同源重组原理构建了fimC基因缺失突变菌株O2（△fimC）。结合PCR扩增、测序结果及透射电镜观察,证明正确构建了fimC基因缺失突变株O2（△fimC）。体外生长及生化反应试验中,O2（△fimC）与亲本株存在一定差异。药敏试验中,两者无明显区别。鸡气管黏膜黏附试验及雏鸡的致病性试验表明：突变株在鸡气管黏膜上的黏附能力是亲本株的1/50,对雏鸡的致病性亦明显下降。鸡致病性大肠杆菌Ⅰ型菌毛fimC基因缺失突变株的构建为深入探讨fimC基因在鸡大肠杆菌致病过程中所起的作用、Ⅰ型菌毛与机体相互作用的分子机制及fimC基因缺失突变株其他生物学特性的研究奠定了物质基础。 相似文献
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fimC基因与鸡源大肠杆菌致病性的相关 总被引：9，自引：3，他引：6
将20株鸡大肠杆菌分别腹腔接种1日龄健康雏鸡,检测其致病性。同时以该20株菌的基因组DNA为模板,应用PCR技术分别进行fimC基因的扩增,结果95％高致病力菌为fimC^ ,而其它非致病性或致病力极低的菌株均为fimC^-。结合相关资料表明,fimC基因几乎只存在于高致病力鸡大肠杆菌中,可以作为高致病力鸡大肠杆菌鉴定的标志基因。将O2菌株PCR扩增产物克隆到pMD18-T载体上,并对其进行酶切鉴定和测序分析,测序结果与参考序列经同源性比较,核苷酸序列同源性为97．9％,氨基酸序列同源性为96．0％,证明所扩增基因是fimC基因。 相似文献
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在系统鉴定、药敏试验和血甭型鉴定的基础上,对52株致病性大肠杆菌和4株标准血清型大肠杆菌进行了质粒DNA分析,结果表明,菌株的质粒得率为100%,来源相同的菌株具有相同或相似的质粒图谱,来源不同的菌株具有不同的质粒图谱,质粒DNA分析为四川规模化猪场致病性E.coli的分子流行病学调查提供了科学依据。质粒图谱与血清型及耐药谱之间无明显关系。 相似文献
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根据GenBank中禽致病性大肠杆菌pilA基因序列设计合成1对引物,以本实验室分离的禽致病性大肠杆菌基因组DNA为模板,采用PCR技术扩增得到pilA基因片段,经测序鉴定准确后将其克隆到乳酸乳球菌表达载体pMG36e中,构建重组质粒并将其电转入乳酸乳球菌MG1363,得到重组乳酸乳球菌。SDS-PAGE分析显示,表达的蛋白约为19 ku,与预期相符。Western blot进一步证实了该蛋白的免疫反应性。 相似文献
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用限制性内切酶SacI和BamHI双酶切克隆有鸡致病性大肠杆菌分离株O1、O2和O78的piliA基因的质粒pTFimO1、pTFimO2和pTFimO78,分别回收从此3质粒上切下的545bp的piliA基因片段,再将载体pET-28a(+)用SacI和BamHI双酶切,最后将pET-28a(+)DNA片段与545bp的piliA DNA片段进行连接,转化至受体菌BL21(DE3)中,经SacI和BamHI酶切反应鉴定重组子,得到了理想重组子质粒pETFimO1、pETFimO2和pETFimO78.重组菌株BL21(DE3) (pETFimO1)、BL21(DE3)(pETFimO2)和BL21(DE3)(pETFimO78)经IPTG诱导后,其表达产物经SDS-PAGE检测,结果表明重组菌株可以良好地表达鸡致病性大肠杆菌Ⅰ型菌毛蛋白. 相似文献
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Rassnick KM Gieger TL Williams LE Ruslander DM Northrup NC Kristal O Myers NC Moore AS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(3):196-199
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
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Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects 总被引：1，自引：0，他引：1
Johansson AM Gardner SY Levine JF Papich MG LaFevers DH Fuquay LR Reagan VH Atkins CE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):887-895
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
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Waruiru RM Thamsborg SM Nansen P Kyvsgaard NC Bogh HO Munyua WK Gathuma JM 《Tropical animal health and production》2001,33(3):173-187
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
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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
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Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ 
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下载免费PDF全文 S. Pashaei T. Ghoorchi A. Yamchi 《Journal of animal physiology and animal nutrition》2016,100(2):211-216
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
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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
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A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance
in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological
status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples
of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected
for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of
the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered,
coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the
gland cisterns and teat cisterns.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L3) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L3 developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone. 相似文献
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Acute phase proteins in dogs naturally infected with the Giant Kidney Worm (Dioctophyme renale) 下载免费PDF全文
下载免费PDF全文 Elizabeth M. S. Schmidt Mads Kjelgaard‐Hansen Funmilola Thomas Asta Tvarijonaviciute José J. Cerón P. David Eckersall 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2016,45(4):657-664