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1.
为了明确禽大肠埃希菌的耐药情况和氨基糖苷抗性基因的流行情况,用K-B纸片扩散法检测了27株致病性大肠杆菌对19种常用抗生素的耐药谱,用PCR方法检测了耐氨基糖苷抗生素分离株的4种氨基糖苷抗性基因,包括腺苷转移酶基因aadA1和aadB、乙酰转移酶基因aacA4 和磷酸转移酶基因apH(3')-Ⅱ.结果表明,氨苄青霉素、安灭菌、青霉素G和四环素的耐药菌株率高达100%,利福平的耐药菌株率达96.3%,氯霉素、红霉素的耐药菌株为70.4%,卡那霉素、环丙沙星、氟哌酸的耐药菌株率为59.3%, 链霉素的耐药菌株达到63.0%.氨苄西林/舒巴坦复方制剂、复达欣、庆大霉素和磷霉素的高敏菌株率分别为100%、 77. 8%、74.1%和51.9%.氨基糖苷抗性基因aadA1、aacA4 和apH(3')-Ⅱ的阳性率分别是44.4%、27.8%和55.6%,aadB未捡出.这些数据提示禽致病性大肠埃希菌存在广泛的耐药谱,氨基糖苷抗性基因aadA1和apH-(3')-Ⅱ是主要流行基因.  相似文献   

2.
合成胸膜肺炎放线杆菌质粒pKMA2425上长度为126bp及2214bp的2个DNA片段,克隆到大肠埃希氏菌质粒pGSI中,获得重组质粒pGSIA。PCR扩增pTKRED上的大观霉素抗性基因及线性化的pGSIA（126bpDNA片段-pGSI-2214bpDNA片段）,连接,电转化胸膜肺炎放线杆菌,在大观霉素的选择压力下筛选鉴定到连接正确的质粒,命名为pGSIAS。pGSIAS测序结果符合预期。在大观霉素的选择压力下,含有pGSIAS的胸膜肺炎放线杆菌血清1-10型菌株均生长良好;在氨苄青霉素的选择压力下,含有pGSIAS的大肠埃希氏菌生长良好。结果表明本研究构建的大肠埃希氏菌-胸膜肺炎放线杆菌穿梭载体pGSIAS序列正确,在胸膜肺炎放线杆菌及大肠埃希氏菌中均能复制并表达质粒上的相关基因。  相似文献   

3.
以含长白猪IFN-λ基因的质粒载体为模板，用原核表达引物扩增了长白猪IFN-λ，基因，将其定向克隆至原核表达载体pET28b的EcoRI和XhoI位点，构建了长白猪IFN-λ基因的原核表达载体pET28b-PoIFN-λ。经酶切、PCR鉴定，表明所构建的重组质粒为特异性长白猪IFN-λ，基因原核表达质粒。将该重组质粒转化大肠埃希氏菌BL21（DE3）细胞，阳性菌落筛选、SDS-PAGE分析以及Western-blotting分析表明，成功构建了表达重组猪IFN-λ的大肠埃希氏菌基因工程菌株。亚细胞定位分析表明，目的蛋白经原核表达后主要以不溶性包涵体形式存在，其他少量可溶性目的蛋白存在于细胞浆中。  相似文献   

4.
研究大肠埃希菌耐药性和耐药基因和十二烷基硫酸钠(SDS)对大肠埃希菌耐药质粒消除作用。以大肠埃希菌临床分离株为试验菌株,采用K-B药敏纸片法对6种抗菌药物进行药物敏感性检测,并对大肠埃希菌耐药质粒TEM1型耐药基因进行PCR检测,采用SDS消除大肠埃希菌临床分离菌株的耐药质粒,采用琼脂糖凝胶电泳检测质粒条带,药敏试验检测大肠埃希菌耐药质粒消除前后的药物敏感性。结果表明,大肠埃希菌对庆大霉素敏感,对大观霉素中敏,对氨苄西林、阿莫西林、头孢拉定、环丙沙星耐药;大肠埃希菌耐药质粒检测出TEM1型耐药基因;试验菌株经7.5g/L的SDS处理至第3代时,质粒条带有明显的减少,TEM1型耐药基因消失,并且恢复了对β内酰胺类抗生素的敏感性,说明耐药质粒已经成功消除。  相似文献   

5.
本试验旨在对临床分离的猪源大肠埃希氏菌耐药基因进行初步定位。采用常规细菌分离培养、16S rRNA PCR扩增和序列测定方法从江西省3个规模化猪场送检的子宫脓液中分离鉴定病原菌,并通过质粒提取、转化大肠埃希氏菌DH5α感受态细胞及药敏试验对临床分离株的耐药基因进行初步定位。结果显示,分离鉴定到3株大肠埃希氏菌,其中JX-22分离株仅对氧氟沙星、大观霉素敏感,JX-26分离株仅对链霉素、氧氟沙星等4种药物敏感,JX-28分离株仅对氧氟沙星等3种药物敏感,均为多重耐药菌;3株大肠埃希氏菌均可纯化到分子质量大小不一的质粒。分离株、质粒转化菌及大肠埃希氏菌DH5α感受态细胞药敏试验对比结果显示,3株大肠埃希氏菌的耐链霉素、林可霉素、甲硝唑、氨苄西林、阿莫西林、大观霉素、丁胺卡那基因,JX-22和JX-26分离株的耐多西环素、氟苯尼考和复方新诺明基因,JX-22分离株的耐头孢曲松基因,JX-28分离株的耐头孢曲松、头孢噻肟、诺氟沙星基因均定位于细菌质粒上;JX-28分离株的耐多西环素、氟苯尼考和复方新诺明基因,JX-22分离株的耐诺氟沙星基因和JX-26分离株的耐头孢曲松、头孢噻肟基因均定位于其染色体上;3株分离株均无氧氟沙星耐药基因。本试验初步确定3株多重耐药猪源大肠埃希氏菌的大部分耐药基因定位于质粒上,为进一步研究猪源大肠埃希氏菌的耐药机理和有效控制措施奠定基础。  相似文献   

6.
根据GenBank中已登录的猪生殖与呼吸综合征病毒（PRRSV）全基因组序列，设计合成了1对特异性引物，对PRRSV非结构蛋白nsp4基因进行了RT-PCR扩增，将回收的目的基因片段克隆到大肠埃希氏菌表达载体pET28a中，构建了重组质粒pET-nsp4，测序结果证实了重组质粒pET-nsp4的可靠性。将pET-nsp4转化至大肠埃希氏菌表达菌株BL21（DE3），用IPTG诱导表达，SDS-PAGE结果表明，重组菌可表达分子质量约23ku的蛋白。经镍离子亲和层析柱（Ni-NTA）纯化，获得了高纯度的重组蛋白，Western-blot分析结果表明，nsp4重组蛋白在大肠埃希氏菌系统中获得了正确表达。  相似文献   

7.
通过核酸类型试验、脂溶性敏感试验，鉴定了1株分离自四川某猪场腹泻病猪粪便的猪传染性胃肠炎病毒（TGEV）。经电子显微镜观察，可以看到大小约90nm的病毒粒子；通过中和试验，将病毒细胞液与TGEV超免疫血清进行中和反应，显示较高的中和抗体效价。根据GenBank中的TGEV序列，设计了1对包含TGEVS基因1760bp部分片段的引物，经RT-PCR扩增获得了1条约1．8kb的条带，通过低熔点琼脂糖凝胶纯化回收该片段后，将其连接在pMD18-T载体上，转化DH5a大肠埃希氏菌。用双酶切和PCR对重组质粒进行鉴定并测序，经用DNAStar软件进行同源性分析和多重序列比较，TGEV四川株（SC-A）与国外报道的部分TGEV分离株具有高达98．8％的同源性。  相似文献   

8.
大肠埃希菌在自然界中广泛存在,在一定的条件下可以引起畜禽患病,在长期治疗过程中,由于药物的选择压力可以引起其对药物的抗性,而且耐药广泛、耐药机制复杂,给疾病临床治疗带来了一定的困难。大肠埃希菌耐药机制主要包括细胞膜通透性改变、细菌产生灭活酶或者钝化酶、靶点结构改变、主动外排泵、质粒介导的大肠埃希菌耐药等。论文介绍了我国部分地区畜牧业中大肠埃希菌耐药现状、大肠埃希菌耐药机制以及应对大肠埃希菌耐药的策略,以便了解耐药大肠埃希菌的传播特点,为防治大肠埃希菌耐药性产生和临床治疗大肠埃希菌感染提供一定的理论指导。  相似文献   

9.
应用PCR方法从包含伪狂犬病病毒（PRV）Fa株糖蛋白gD基因的重组质粒pB13中扩增出糖蛋白gD基因去信号肽片段，将其克隆到大肠埃希氏菌表达载体pThiohisA中。测序结果表明，糖蛋白gD基因去信号肽片段长1155bp，与PRVFa株糖蛋白gD基因完全一致。经1mmol／L IPTG诱导后，重组质粒pThiohisA-gD在大肠埃希氏 菌XL1-blue、Top10、DE3和DH5a中均得到表达，其中在宿主菌XL 1-blue中表达量最高。Western-blotting结果显示，大肠埃希氏菌XL1-blue表达的糖蛋白gD具有免疫原性。  相似文献   

10.
狂犬病的分子生物学诊断   总被引：3，自引：0，他引：3  
从攻击咬伤人并致其死亡的犬脑组织中提取总RNA，用特异性引物通过反转录聚合酶链反应(RT—PCR)获得了长度约为1423bp的核酸片段，与预期的片段大小相符；将扩增产物连接到pMD18-T载体中，转化大肠埃希氏菌JM109，筛选氨苄青霉素抗性菌落，提取质粒，经酶切鉴定、PCR分析及测序，证明所克隆的1423bp片段含有完整的狂犬病病毒N基因，与国外参考毒株的序列相比同源性较高，从而做出正确的诊断。试验表明，用RT—PCR技术检测狂犬病病毒灵敏度高、特异性强，适合于实验室应用。  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.
Tropical Animal Health and Production -  相似文献   

13.
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   

14.
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   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
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   

17.
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   

18.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

19.
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   

20.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

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