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1.
将坏死梭杆菌FN(AB)94分离株以10^6,10^7,10^8,10^9 个/mL等不同菌量,于耳后根颈部皮下分别接种于4组的健康实验家兔,每组3只,逐日观察感染家兔的发病情况,结果,10^8,10^9个/mL,菌量感染组家兔,在接种后9-68 d内先后死亡,68d死亡家兔的病理变化明显,并从死亡家兔内脏及脓法叶,应用触片及分离培养均检到长丝状及小杆状等形态典型的坏死梭杆菌,10^7个/mL感染家兔仅表现体重减轻,10^6个/mL感染家兔无明显临床表现,由此表明,坏死梭杆菌FN(AB)94分离株具有很强的感染毒力,对家兔的最小致死量为10^8个/mL,耳后板颈部皮下接种是适宜的感染途径,从而建立了坏死梭杆菌分离株实验动物感染模型。  相似文献   

2.
为建立稳定的猪链球菌2型(Streptococcus suis type 2,SS2)人工发病模型,本试验以天津某发病猪场分离的SS2 Y15293株为研究对象,经腹腔注射感染昆明小鼠,测定其LD50,确定造模感染剂量,通过观察感染后小鼠的临床症状和病理变化,测定试验期间各组小鼠体重和采食量的变化及细菌回归等试验对模型进行评估。结果显示,SS2 Y15293株致昆明小鼠的LD50为6.7×10~7 CFU/mL。以1个LD50的剂量攻毒,与对照组相比,试验小鼠主要发病表现为攻菌后24 h出现精神沉郁、被毛逆立、眼睛有分泌物,72~96 h出现头颈歪斜、翻滚、震颤等神经症状,死亡高峰在48~72 h。3次重复试验中,试验组小鼠的发病率均为100%,死亡率为50%~70%,神经症状小鼠出现比率20%~30%。与对照组相比,试验组小鼠采食量和体重显著下降(P<0.05),临床症状分值显著升高(P<0.05)。组织病理检查发现,试验组小鼠心脏、肺脏组织均有不同程度出血、炎性细胞浸润;脑膜炎,脑室出血,充满炎性细胞。细菌回归试验结果表明,试验组死亡小鼠脑、心脏、肝脏、脾脏、肺脏、肾脏均有细菌定植,且形态、染色和分子生物学特性与攻毒菌一致。以上结果证实,SS2 Y15293株能感染昆明小鼠并致其发病,感染动物发病规律性强,重复性好,临床症状典型,说明SS2 Y15293株感染昆明小鼠可作为SS2的候选人工感染模型。  相似文献   

3.
将含GM-CSF基因与生长抑素(SS)的融合真核表达质粒pGM-CSF/SS转入减毒沙门氏菌株CS022。选择40只22~24 g的雌性小鼠,随机分成4组,其中1组为对照组,口服生理盐水;2~4组为试验组,分别用上述重组减毒沙门氏菌株CS022以108、109、1010CFU的剂量口服免疫小鼠,2周后以相同的剂量加强免疫,研究pGM-CSF/SS真核表达质粒在体内的稳定性和减毒沙门氏菌对小鼠的安全性。同时通过体外传代,研究该真核表达质粒在体外的稳定性。结果表明:108、109CFU剂量口服小鼠,成活率达100%,而1010CFU剂量口服小鼠成活率降低至90%,腹泻率达50%。体外传10代和口服免疫4周后从小鼠肝脏和脾脏分离的减毒菌用琼脂糖凝胶电泳和酶切鉴定法证实,减毒菌中的重组质粒在体外和侵入小鼠体内过程中具有较好的稳定性。质粒DNA在传10代以后,虽然每代的质粒DNA含量有些变化,但总体趋势基本是恒定的,第10代时,质粒DNA的含量与第1代的含量差异不显著。上述结果提示,利用该减毒沙门菌作为载体传递pGM-CSF/SS DNA疫苗免疫小鼠具有相对安全性和稳定性,为进一步有效激发机体的免疫应答提供了前提。  相似文献   

4.
三种布鲁氏菌病疫苗株的毒力比较   总被引:4,自引:2,他引:2  
为系统比较我国现有布鲁氏菌病疫苗株A19、M5和S2的毒力,分别用上述3种疫苗株以1×105CFU/只免疫Balb/c小鼠,免疫后每隔2周采集小鼠脾脏,分离细菌,测定各疫苗株在小鼠脾脏中的存留时间。结果 A19、M5、S2在小鼠体内存活时间依次为14周、大于16周、6周。将以上3种疫苗株分别以1×109CFU/只免疫Hartley豚鼠,15日后测定豚鼠脾脏含菌量,结果 A19、M5、S2免疫后每克脾脏含菌量分别为2.8×104CFU、大于6.7×105CFU、3.8×103CFU。研究结果表明,我国目前使用的布鲁氏菌疫苗中,S2毒力最弱,A19其次,M5最强。  相似文献   

5.
为建立稳定的猪链球菌2型(Streptococcus suis type 2,SS2)人工发病模型,本试验以天津某发病猪场分离的SS2 Y15293株为研究对象,经腹腔注射感染昆明小鼠,测定其LD_(50),确定造模感染剂量,通过观察感染后小鼠的临床症状和病理变化,测定试验期间各组小鼠体重和采食量的变化及细菌回归等试验对模型进行评估。结果显示,SS2 Y15293株致昆明小鼠的LD_(50)为6.7×10~7 CFU/mL。以1个LD_(50)的剂量攻毒,与对照组相比,试验小鼠主要发病表现为攻菌后24 h出现精神沉郁、被毛逆立、眼睛有分泌物,72~96 h出现头颈歪斜、翻滚、震颤等神经症状,死亡高峰在48~72 h。3次重复试验中,试验组小鼠的发病率均为100%,死亡率为50%~70%,神经症状小鼠出现比率20%~30%。与对照组相比,试验组小鼠采食量和体重显著下降(P0.05),临床症状分值显著升高(P0.05)。组织病理检查发现,试验组小鼠心脏、肺脏组织均有不同程度出血、炎性细胞浸润;脑膜炎,脑室出血,充满炎性细胞。细菌回归试验结果表明,试验组死亡小鼠脑、心脏、肝脏、脾脏、肺脏、肾脏均有细菌定植,且形态、染色和分子生物学特性与攻毒菌一致。以上结果证实,SS2 Y15293株能感染昆明小鼠并致其发病,感染动物发病规律性强,重复性好,临床症状典型,说明SS2 Y15293株感染昆明小鼠可作为SS2的候选人工感染模型。  相似文献   

6.
为探明猪链球菌2型(Streptococcus suis type 2,SS2)感染肺组织的主要病变及其在肺组织中的分布,并针对病变的肺脏进行系统的病理学研究。选取6头SPF巴马小型猪,5头用于实验组,分别肌肉注射1×109 CFU/mL的SS2菌液2mL;1头对照猪注射等体积生理盐水。记录死亡时间,同时观察死亡前实验小型猪的临床症状变化;剖解病死猪,观察肺部病变;随机取部分肺组织计算肺脏的湿/干比值,分析其与死亡时间的关系;取病变肺组织进行组织病理学观察;制作冰冻切片,用SS2荧光抗体检测SS2在肺组织中定位和菌量。结果显示:(1)实验组2头感染小型猪在6h内发生急性死亡,且死亡前没有任何神经症状,只是存在呼吸异常等症状,同时其肺脏的湿/干比值最大;另3头分别在感染12、20h和36h死亡,死亡前具有SS2典型的神经和呼吸异常症状,肺脏的湿/干比值也随之降低,可见死亡越早肺水肿程度越严重。(2)病死猪肺组织病理学观察结果显示,肺泡的间隔增宽,出血,有大量炎性物质渗出,肺泡腔内可见数量不等的红细胞、中性粒细胞、淋巴细胞和浆液性渗出物等典型的间质性肺炎特征症状。(3)SS2荧光抗体检测显示SS2可侵入肺组织的各个部位,并且在6h和20h菌量相接近。结果表明SS2感染小型猪肺病变以炎症反应为主,并发现SS2感染诱发动物急性死亡与其感染导致呼吸功能衰竭有关。  相似文献   

7.
为了解天鹅源丙型副伤寒沙门菌的公共卫生学意义,并建立天鹅源丙型副伤寒沙门菌感染小鼠的实验动物模型。采用腹腔注射和人工灌服途径感染小鼠,了解感染鼠的LD50,观察灌服鼠于灌服后不同时段的临床症状、病理变化、血清生化指标、粪便排菌情况。结果表明,腹腔注射感染鼠的LD50为4.55×107 CFU/mL,人工灌服途径感染鼠的LD50为1.8×109 CFU/mL;用菌液浓度2×106 CFU/mL灌服感染鼠6h开始发病,6~96h精神沉郁、嗜睡、食欲减退,有腹泻、死亡;病、死鼠(12h)呈现肠黏膜坏死脱落、肠壁变薄,肠腔有多量黄色黏液状的内容物,肺脏有出血性病变,24h肝脏表面见有点状坏死;感染后36h的尿酸、72h的谷丙转氨酶、谷草转氨酶显著升高直至120h,尿素氮在72~96h明显升高,碱性磷酸酶活性在48~96h显著降低,血糖、蛋白在72~120h明显下降;2种途径感染8h后小鼠的粪便皆可检出感染菌,且粪便排菌的持续时间与感染剂量呈正相关,0.5mL/只(2×1010 CFU/mL)感染鼠直至感染后23d粪便仍有排菌,表明天鹅源丙型副伤寒沙门菌对试验小鼠有致病性,感染后经粪便长期排菌。  相似文献   

8.
以亚成体大熊猫病原菌EL-1和EL-2菌株注射实验动物小白鼠(KM),测定其半数致死量,其中EL-1菌株LD50为2.75×10~8CFU/只,EL-2菌株LD50为4.03×10~8CFU/只,两菌制成灭活菌苗按一定的浓度梯度注射实验动物家兔,其最佳的免疫剂量为1×10~8CFU/只家兔。  相似文献   

9.
家兔大肠埃希氏菌病是由大肠埃希氏菌的某些特定血清型株感染所引起的,发生于家兔、豚鼠等的肠道传染病,常在家兔群中形成大范围传播,并且可导致感染兔死亡。家兔大肠埃希氏菌病尤其对幼龄兔(4~6周龄幼兔)的影响最为严重,其不但极容易受到感染,而且在感染后常常迅速死亡。贵阳医学院实验动物中心饲养的家兔,近年来多次发生大肠埃希氏菌病,为了有效地控制该病的发生与发展,我们对2002年10月的发病家兔进行了病原学检查和治疗观察,现将结果报告如下。1发病情况与临床表现发病动物主要表现为腹泻,少食,体温降低或正常,并且多数迅速死亡。大多…  相似文献   

10.
为了测定牛、羊、猪三株不同种布鲁氏菌参考强毒株的毒力,选择了牛种2308、羊种M28和猪种S1330株,分别用雌性豚鼠(Hartley)和雌性小鼠(Balb/c)对其毒力进行测定。豚鼠测毒试验中,用含不同菌数的菌液腹股沟皮下注射5只豚鼠,测定2308、M28、S1330菌株的豚鼠最小感染量(MID),结果显示以上3种毒株对豚鼠的最小感染量分别为9 CFU、10 CFU和30CFU。小鼠测毒实验中,将2308、M28和S1330菌液按1×105CFU/0.2 mL/只腹股沟皮下注射小鼠各5只,2周后分别剖杀小鼠,取脾脏测定含菌量,平均脾含菌量分别为1676971、314765、83811CFU/g脾脏。豚鼠和小鼠测毒均显示牛种2308株毒力最强,羊种M28株次之,猪种S1330毒力最弱。本研究首次用豚鼠和小鼠同时测定了布鲁氏菌2308、M28、S1330株的毒力,补充了布鲁氏菌参考强毒株的毒力数据。  相似文献   

11.
2种猪源链球菌对猪、兔的致病性试验   总被引:2,自引:1,他引:2  
检测了4株猪链球菌2型(Streptococcus suistype 2,SS2)和2株马链球菌兽疫亚种(Streptococcus equisubsp.zooepidem icus,SEZ)对猪、兔的致病性。SS2-1、SS2-H及SS2-006444株均分离自发病猪内脏,前2株毒力因子表现型为MRP+EF+SLY+,后者为MRP-EF-SLY-;SS2-D株为国外引进的SS2人源株,作为对照,其毒力因子的表现型为MRP+EF*SLY+;SEZ-CY和SEZ-CN株均分离自发病猪并经鉴定。SS2-1、SS2-H、SEZ-CY和SEZ-CN株对猪(2~3头/组)的最小致死量分别为106、107、104和108cfu;对兔(2~3只/组)的最小致死量分别为100~1 000、1 000、100和105cfu;SS2-D株108cfu对猪不致死,对兔的最小致死量为108cfu,而SS2-006444对猪、兔无致病性。显示SS2毒力因子与其对猪、兔的致病性有关;SS2与SEZ菌株对兔或猪的致病性一致,可用兔取代猪做试验;SS2和SEZ菌株通过腹腔、皮下、肌肉或静脉注射均可感染兔(2~4只/组),并致死,SEZ还可经口、鼻感染;SEZ与SS2静脉感染猪后10 m in即可检出细菌,此后2~4 h为无菌血症阶段,之后重新出现。  相似文献   

12.
The pharmacokinetics of a 2:1 ampicillin-sulbactam combination in six rabbits, after intravenous and intramuscular injection at a single dosage of 20 mg/kg bodyweight (13.33 mg/kg of sodium ampicillin and 6.67 mg/kg of sodium sulbactam) were investigated by using a high performance liquid chromatographic method for determining plasma concentrations. The plasma concentration-time curves were analysed by compartmental pharmacokinetic and noncompartmental methods. The disposition curves for both drugs were best described by an open two-compartment model after intravenous administration and a one-compartment model with first order absorption after intramuscular administration. The apparent volumes of distribution calculated by the area method for ampicillin and sulbactam were 0.62 +/- 0.09 and 0.45 +/- 0.05 L/kg, respectively, and the total body clearances were 0.65 +/- 0.04 and 0.42 +/- 0.05 L/kg h, respectively. The elimination half-lives of ampicillin after intravenous and intramuscular administration were 0.64 +/- 0.11 and 0.63 +/- 0.16 h, respectively, whereas for sulbactam the half-lives were 0.74 +/- 0.12 and 0.77 +/- 0.17 h, respectively. The bioavailability after intramuscular injection was high and similar in both drugs (73.34 +/- 10.08% for ampicillin and 83.20 +/- 7.41% for sulbactam). The mean peak plasma concentrations of ampicillin and sulbactam were reached at similar times (0.20 +/- 0.09 and 0.34 +/- 0.15 h, respectively) and peak concentrations were also similar but nonproportional to the dose of both products administered (13.07 +/- 3.64 mg/L of ampicillin and 8.42 +/- 1.74 mg/L of sulbactam). Both drugs had similar pharmacokinetic behaviour after intramuscular administration in rabbits.  相似文献   

13.
1. Disposition kinetics were compared in healthy chickens and in chickens naturally infected with E. coli following the intravenous, intramuscular and oral administration of chloramphenicol in a single dose of 20 mg/kg body weight. 2. Lower serum chloramphenicol concentration in diseased chickens were reported after intravenous injection, but they were higher than normal 30 min after intramuscular and oral administration. Following intravenous injection the volume of distribution was increased in diseased chickens. 3. The biological half-life in normal chickens was 8.32 +/- 0.5 h and was prolonged in diseased birds (26.21 +/- 0.2 h). The body clearance of chloramphenicol was reduced in diseased chickens. 4. The rate of absorption of chloramphenicol was delayed after administration via the oral route but the extent of absorption was increased. The maximum concentration was higher and it was reached after a longer time in diseased than in normal chickens after administration by both intramuscular and oral routes.  相似文献   

14.
选择泌乳期(7~10日)家兔,用10^4CFU、10^6CFU、10^8CFU三个不同浓度的金黄色葡萄球菌悬液人工诱导家兔乳房炎模型,观察临床表现,耳缘静脉采血进行血常规检测,确定10^6CFU为建立乳房炎模型的最佳剂量。造模后,分别采用不同剂量的中药组方制剂,通过乳池灌注和肌肉注射两种方式治疗患病家兔,观察临床治疗效果并检测血常规,确定乳池灌注和肌肉注射的最佳治疗剂量分别为35mg/乳区、100μg/kg,治愈率均为100%(8/8)。  相似文献   

15.
The pharmacokinetics of azithromycin after intravenous and intramuscular injection at a single dose rate of 10mg/kg bodyweight were investigated in rabbits by using a modified agar diffusion bioassay for determining plasma concentrations. The plasma creatine kinase activity was determined after i.m. administration for the evaluation of the tissue tolerance. The elimination half-lives of azithromycin after intravenous and intramuscular administration were 24.1 and 25.1h, respectively. After intramuscular administration mean peak plasma concentration was 0.26+/-0.01 mg/L and bioavailability was 97.7%. Plasma CK activity rose sharply within 8h after i.m. injection of azithromycin; activity returned to pre-treatment level by 48-72 h post-treatment. The transient rise in serum CK activity indicates some degree of muscle tissue damage at the injection site.  相似文献   

16.
1. Disposition kinetics of florfenicol were studied in Pasteurella-free (control) and Pasturella-infected Muscovy ducks following intravenous and/or intramuscular injection in a single dose of 30 mg/kg body weight. In addition, the tissue distribution and residual pattern of the drug were determined in diseased ducks. 2. The maximum serum concentration of florfenicol in control healthy and infected ducks was reached 1 hour after intramuscular injection but the peak concentration in control ducks was higher than in infected birds. 3. The volume of distribution, total body clearance and systemic bioavailability were higher in infected ducks than in control birds 5.15 l/kg, 10.24 ml/kg/min and 73.03% respectively. Data relating to intravenous injection were analysed using a 2 compartment open model curve fit. 4. Florfenicol was not detected in the serum of infected ducks on the 7th day following intramuscular administration of 30 mg/kg body weight twice daily for 5 successive days but was detected in kidney, bile and liver.  相似文献   

17.
将小鼠人工感染日本血吸虫尾蚴 40条 /只 ,30 d后将苏云金杆菌伴胞晶体蛋白以不同的给药方式 (静脉注射、肌肉注射、灌胃、腹腔注射 )给药 ,用药后 15 d剖检查虫。结果发现 ,各种给药方式对小鼠体内的日本血吸虫成虫均有一定的效果 ,但以静脉注射效果最好 ,肌肉注射次之 ,灌胃和腹腔注射效果较差。这表明苏云金杆菌制剂作用于小鼠体内的日本血吸虫时 ,静脉注射是最佳给药途径。  相似文献   

18.
对从广州禽产品分离的6株LM进行了药敏试验、pH值的适应范围、动物致病性等生物学特性研究。6株LM分离株对先锋必、氯霉素、卡那霉素、头孢唑啉、庆大霉素等多种药物敏感;而对多黏菌素B、复方新诺明、新生霉素有耐药性。LM分离株在pH值4.0~10.5范围内可存活。以109 CFU剂量感染SPF小鼠、清洁级新西兰兔和健康粤黄鸡,小鼠的致死率达100%,可引起兔结膜炎等症状,但未引起试验鸡的任何不适。6株LM分离株的Hly基因与标准参考株基因相似性达到96.1%以上,说明该基因在LM中较为保守。  相似文献   

19.
Cefotaxime was administered to goats intravenously, intramuscularly and subcutaneously to determine blood and urine concentration, kinetic behaviour and bioavailability. Following a single intravenous injection, the blood concentration-time curve indicated a two compartment open model, with an elimination half-life value (t1/2 beta) of 22.38 +/- 0.41 minutes. Both intramuscular and subcutaneous routes showed slower values, that is, 38.64 and 69.58 minutes. The apparent volume of distribution of cefotaxime in goats was less than 1 litre kg-1 and suggested a lower distribution in tissues than in blood. After intramuscular and subcutaneous injections peak plasma cefotaxime concentrations were 77.8 +/- 1.7 and 44.0 +/- 0.8 micrograms ml-1 at 29.6 and 40.4 minutes, respectively. The average bioavailability of cefotaxime given by intramuscular and subcutaneous injection was 1.08 and 1.25 times the intravenous availability, respectively. The cefotaxime concentration remained in urine 24 hours longer after subcutaneous injection than after intramuscular administration.  相似文献   

20.
The pharmacokinetics of a 2:1 ampicillin-sulbactam combination were studied in 6 sheep, after intravenous and intramuscular injection at a single dose rate of 20 mg/kg body weight (13.33 mg/kg of sodium ampicillin and 6.67 mg/kg of sodium sulbactam). The drugs were distributed according to an open 2-compartment model after intravenous administration and a one-compartment model with first order absorption after intramuscular administration. The apparent volumes of distribution calculated by the area method of ampicillin and sulbactam were 0.32+/-0.06 L/kg and 0.42+/-0.04 L/kg, respectively and the total body clearances were 0.69+/-0.07 and 0.38+/-0.03 L/kg x h, respectively. The elimination half-lives of ampicillin after intravenous and intramuscular administration were 0.32+/-0.05 h and 0.75+/-0.27 h, respectively, whereas for sulbactam the half-lives were 0.74+/-0.10 h and 0.89+/-0.16 h, respectively. The bioavailability after intramuscular injection was high and similar in both drugs (72.76+/-9.65% for ampicillin and 85.50+/-8.35% for sulbactam). The mean peak plasma concentrations of ampicillin and sulbactam were reached at similar times (0.25+/-0.10 h and 0.24+/-0.08 h, respectively) and peak concentrations were also similar but nonproportional to the dose of both products administered (13.01+/-7.36 mg/L of ampicillin and 10.39+/-3.95 mg/L of sulbactam). Both drugs had a similar pharmacokinetic behavior after intramuscular administration in sheep. Since the plasma concentrations of sulbactam where consistently higher during the elimination phase of their disposition, consideration could be given to formulating the ampicillin-sulbactam combination in a higher than 2:1 ratio.  相似文献   

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