羊云翳病原微生物的分离鉴定

近年来，华北地区的各养羊场流行着一种云翳病。作者对发病的羊只进行了病原的分离，经生化试验及生物学特性。试验证实，该分离菌为李氏杆菌，经动物试验，验证了李氏杆菌即是引起羊云翳的病原菌，试验过程中对分离菌进行了11种药物的敏感性试验，其中对氨苄青霉素、庆大霉素、卡那霉素、林可霉素高度敏感。     

鸡胚内沙门氏菌的分离与鉴定

从某场１—１２日龄的死亡的鸡胚中分离培养出一株细菌，经选择培养、生化试验、血清学试验、动物回归试验等系列的实验诊断方法，鉴定为鸡沙门氏菌。通过药敏试验并反馈回某鸡场进行防治，取得了满意的治疗过果。     

基于重组Erns蛋白的猪瘟Erns-ELISA的建立和优化

将大肠杆菌表达的猪瘟病毒重组E^rns蛋白经纯化后作为包被抗原，建立了检测猪瘟抗体的E^rns-ELISA方法。经优化试验，确定了最适抗原包被量为0．15 μg；血清最适稀释度为1：100。经阻断试验、交叉反应试验和重复性试验证明，建立的E^rns-ELISA简便、特异、稳定，与基于重组E2蛋白的E2-ELISA的符合率高达96.7％，与基于全病毒抗原的Dot-ELISA符合率为77．5％。可以用于猪瘟抗体的血清学监测以及用作基于E2蛋白的标记疫苗配套的鉴别诊断。     

绵羊肺腺瘤病毒SYBRGreenI实时荧光定量PCR检测方法的建立及应用

根据GenBank登录的绵羊肺腺瘤病毒gag基因序列设计1对特异性引物，经RT—PCR扩增出了276bp的片段。产物经回收与pMD18-TVector连接后转化到基因工程菌DH5a中，提取重组质粒，经PCR及测序鉴定后，作为阳性模板建立SYBRGreenI荧光定量PCR标准曲线，并做敏感性试验、特异性试验、重复性试验和临床检测应用。结果表明，标准曲线循环阈值与模板浓度呈良好的线性关系，产物Tm在82～82．5℃之间，灵敏度为2．22个拷贝／μL，特异性和重复性较好，较常规RT—PCR方法提前1h出检测结果。本试验建立了检测JSRV的SYBR—GreenI荧光定量PCR方法，为该病的早期快速诊断，并定量分析JSRV感染程度奠定了基础。     

PHLTA—2000对雏鸡生长及免疫效果影响的试验研究

从某场1－12日龄的死亡的鸡胚中分离培养出一株细菌，经选择培养、生化试验、血清学试验、动物回归试验毓的实践诊断方法，鉴定为鸡沙门氏菌。通过药敏试验并反馈回某鸡场进行防治，取得了满意的治疗效果。     

貂,貉,犬多种免疫球蛋白的研究与应用

利用犬温热，细小病毒性肠炎，犬传染性肝炎，狂犬病等弱毒株，以香菇多糖和动物的核糖，多肽做为免疫增强剂，对异源动物羊，猪，犊牛，家兔进行了免疫应答，筛选出了猪做为异源免疫动物。在免疫增强剂的参与下，完成了多次免疫应答，达到了理想的免疫球蛋白（ＩｇＧ），通过试验摸清了该制剂的免疫程序，确定了生产工艺，经重复性试验，稳定性试验及含量测定，以及临床应用试验和现志应用试验均达以了预期效果，该制剂经冷冻干燥后     

水貂肺炎链球菌病的诊断与防治措施

在发生急性死亡的水貂脑中分离到9株细菌，经细菌培养、染色镜检、生化试验、动物试验证实分离菌株均为肺炎链球菌。药敏试验结果：分离菌株大部分对氟苯尼考、阿米卡星、头孢噻肟、氨苄西林、呋喃妥因敏感，应用敏感抗菌素与疫苗紧急免疫的方式，对该病的综合防治措施做了一系列探索式研究，并取得了理想的防治效果。     

试验感染牛野生型蓝舌病毒血清8型胎盘及口腔传播的研究

本试验旨在探究野生型蓝舌病毒血清8型（BTV-8）对牛的潜在垂直传播。试验结果表明，1头犊牛经胎盘传播感染野生型BTV-8，用另1头犊牛经口感染野生型BTV-8。用15头怀孕8个月的多次经产母牛中的7头进行BTV-8感染试验，RRT—PCR检测结果表明，每头新生犊牛摄食初乳之前就已经胎盘感染了BTV，如果经胎盘感染试验不成立，那么给犊牛饲喂感染BTV-8母牛的初乳或未感染BTV-8母牛的初乳。初乳中掺入含BTV-8的血液。     

小熊猫败血性肺炎病原的分离鉴定

本文报道动物园小熊猫发生的以肺部呈现典型充血、出血而导致在圈短时间内死亡的病例，对其病原进行了详细的检查，经病原形态学观察、培养特性、小白鼠致病性试验及生化试验确定为巴氏杆菌，同时，对该病症的其他病原进行了比较试验。     

金丝雀痘诊断与痘病毒致弱试验

本试验对送检的金丝雀经实验室诊断，确认为金丝雀痘，对分离的痘病毒进行动物致病性试验、病毒分离传代和致试验、致弱毒保护力试验和返强试验。结果表明：金丝雀痘病毒经鸡胚盲传３后能适鸡胚并致死金丝雀，８代后无致病性，１３例毒性快速通过本动物３次无返强现象，金丝雀用第１３代毒刺种３０天能抵抗强毒攻击。     

Pharmacokinetic study of sulfadimethoxine depletion in suckling and growing pigs.

Sulfadimethoxine was administered (IV) to suckling pigs (1 to 2 weeks old) and to growing pigs (11 to 12 weeks old) at a dosage of 55 mg/kg of body weight (single dose). Blood samples were collected over a 48-hour period, and the animals euthanatized were used for measurements of plasma and tissue concentrations of the drug. The blood data were described, using a one-compartment pharmacokinetic model. The blood concentration curves for the two groups of pigs had a consistent depletion pattern with greater than therapeutic concentrations (50 micrograms/ml) of the drug persisting through 12 hours after the drug was given. Sulfonamide blood concentrations were 4 and 11 times that of the method sensitivities in the older (growing) and younger (suckling) pigs, respectively, at 48 hours after treatment. In four of the five pharmacokinetic variables studied, a significantly higher (P less than 0.01) degree of efficiency was observed in the ability of the older pigs to eliminate the drug than in the younger pigs.     

The response of pigs experimentally infected with trypanosoma brucei to isometamidium chloride therapy and the relation to nutrition

Summary

Growing pigs were placed on feeds with high (Group A), medium (B) and low (C) dietary energy and were infected with a virulent stock of T. brucei. Eight weeks later, the infected pigs were treated with isometamidium chloride at 1mg/kg live weight and all pigs were subsequently placed on a high energy diet to investigate their response to therapy.

Clearance of T. brucei from blood was completed 72h after treatment. There was no evidence of relapsed infection up to eight weeks after treatment. Red blood cell parameters returned to normal four to six weeks after treatment with responses being fastest in Group A, B and C had gained about two‐thirds of the live weight gains of their non‐infected pair‐fed controls.

It appears that the retarded weight gain as a result of the infection persisted after therapy since drug‐treated pigs did not gain as much weight as their non‐infected controls.     

The effects of body composition on the pharmacokinetics of subcutaneously injected ivermectin and moxidectin in pigs

Macrocyclic lactones are characterized by their long persistence in animals because of their extensive distribution into fat. This study examined the influence of body condition on the disposition of ivermectin (IVM) and moxidectin (MXD) in blood and fat following subcutaneous (s.c.) drug administration. 'Fat' and 'thin' lines of pigs were established using two different diets. All animals were then injected with either MXD or IVM at 300 microg/kg and blood samples were taken at regular intervals until slaughter. Two IVM-treated animals from each diet group were slaughtered at either 3 days or 3 weeks posttreatment. Two MXD-treated animals from each diet group were slaughtered at 3 days, 3, 6 or 9 weeks after treatment. Samples of backfat were taken from all animals at slaughter. Fluorescence HPLC was used to determine the concentrations of MXD or IVM in the plasma and fat samples. The plasma IVM concentration peaked more rapidly in the thin IVM treated pigs compared with the fat pigs. The concentration of IVM in backfat was significantly lower in the thin animals slaughtered 3 weeks after treatment. The MXD plasma concentration peaked within the first hour in both the thin and fat groups, but from 12 h posttreatment there was a higher MXD concentration in the plasma of the fat pigs resulting in MXD being detectable in these pigs for 28 days compared with only 17 days in the thin pigs. Despite this difference in plasma persistence no differences were seen in the MXD concentration of backfat between fat and thin animals. Body condition influenced the kinetic disposition of IVM and MXD following s.c. drug administration with both drugs being less persistent in thin compared with fat animals.     

猪溶血性链球菌的分离鉴定及溶血素基因的PCR检测

为了建立简便、快捷、准确的猪溶血性链球菌实验室诊断方法,试验采用无菌操作技术将疑似猪链球菌病的猪组织接种于血平板上培养,对染色、镜检为链球菌的菌落进行分离纯化,然后进行生化鉴定、动物致病性试验、药敏试验。根据GenBank发布的猪链球菌溶血素基因(sly)全序列,设计1对特异性引物,然后抽提分离菌DNA扩增出大小为568 bp的目的片段。结果表明:使用此鉴定方法可简便、快捷、准确地检测出猪溶血性链球菌溶血素基因。     

Pharmacokinetics of 4-aminopyridine derivatives in dogs

Blockade of potassium channels with 4-aminopryidine (4-AP) restores conduction to demyelinated axons and improves function. Unfortunately, 4-AP causes adverse effects and its clinical effects are unpredictable and limited. Derivatives of 4-AP have been tested in models of spinal cord injury in guinea pigs; three derivatives (methyl-, ethyl- and t -butyl carbamate derivatives) showed promise. This study investigates the safety and pharmacokinetics of these derivatives in dogs. Each derivative was administered orally to dogs starting at doses below effective doses in guinea pigs, and increasing the dose on sequential days. Routine blood work was performed prior to and 24 h after drug administration, blood samples were collected at intervals over 24 h after drug administration, and dogs were monitored for side effects. Derivative plasma levels were determined using high-pressure liquid chromatography. Cerebrospinal fluid (CSF) samples were taken to determine CSF levels. No adverse effects were seen even when using doses higher than those that improved conduction in spinal cord injured guinea pigs. Peak plasma levels occurred at 36.6 (ethyl), 87 ( t -butyl) and 175 (methyl) min and plasma level was related to drug dose. Penetration of the central nervous system (CNS) was good, with CSF levels higher than plasma levels for the t -butyl derivative.     

上海地区31株2型猪链球菌的分离鉴定及其耐药性分析

猪链球菌病是由猪链球菌引起的一种重要人畜共患病,尤其是猪链球菌2型,不仅对猪的致病性最强,而目可感染特定人群并致死,给人类公共卫生和养猪业带来巨大影响。本研究采集临床症状疑似2型猪链球菌感染猪的全血及内脏器官,通过观察菌落形态及培养特征,筛选出可疑样品,纯化培养并进行PCR鉴定,筛选到31株2型猪链球菌,最后用纸片扩散法对临床分离到的2型猪链球菌菌株测定其耐药性,结果显示对5种药物耐药率分别为：80%（AM）、68%（GM）、84%（CHL）、52%（SXT）、55%（CIP）。试验结果表明分离的31株2型猪源性链球菌,均为多重耐药株,且青霉素类药物的耐药性较为严重,这为临床在治疗2型猪链球菌病提供了合理的指导作用。     

Development of a diagnostic PCR assay based on novel DNA sequences for the detection of Mycoplasma suis (Eperythrozoon suis) in porcine blood

An efficient method of control of porcine eperythrozoonosis (PE) caused by Mycoplasma suis is eradication of infection by detection and removal of infected carrier animals. At present, only a few tests are available for the diagnosis of these latent M. suis infections in pigs. The objective of this study was to develop a PCR assay based on novel DNA sequences for the identification of M. suis-infected pigs. A 1.8 kb EcoRI DNA fragment of the M. suis genome was isolated from the blood of pigs experimentally infected with M. suis. Specificity of the DNA fragment was confirmed by DNA sequence analysis and PCR using primers directed against sequences contained in the 1.8 kb fragment. PCR products of 782 bp in size were amplified only from M. suis particles prepared from the blood of experimentally infected pigs but not from any controls, comprising blood from gnotobiotic piglets and a panel of bacteria including other porcine mycoplasmas. PCR results were confirmed by dot blot hybridisation. The applicability of the PCR assay to diagnose M. suis infections in pigs was evaluated by investigating blood samples from 10 symptomatic pigs with clinical signs typical of porcine eperythrozoonosis and blood samples from 10 healthy pigs. The M. suis-specific PCR product was amplified from all samples taken at episodes of acute disease as well as from samples taken during the latent stage of infection, thus demonstrating the suitability of the PCR assay for detecting latent infected carrier animals.     

Impact of an experimental PRRSV and Streptococcus suis coinfection on the pharmacokinetics of ceftiofur hydrochloride after intramuscular injection in pigs

This study determined the impact of porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis coinfection on the pharmacokinetic (PK) profile of ceftiofur hydrochloride in pigs after intramuscular (i.m.) injection. Eighteen clinically normal crossbred gilts were assigned by weight into a challenge group (10 pigs) and control group (eight pigs). Pigs in both groups received a single i.m. injection of ceftiofur hydrochloride (Excenel RTU Sterile Suspension; Zoetis) at a 5 mg/kg BW dose. Serial blood samples were collected to characterize the plasma concentration curve. After a 10 days drug washout period, the challenge group was inoculated with 2 mL of PRRSV isolate VR‐2385 (10^5.75 50% tissue culture infective doses per mL) intranasally and 8 days later inoculated S. suis. When clinical disease was evident, the second PK assessment began in both challenge and control groups. Coinfected pigs demonstrated lower values of AUC and C_MAX, but higher values of Cl/F and Vz/F indicating drug kinetics were altered by infection. The data from this study have implications on ceftiofur treatment regimens in diseased pigs.     

Secondary effects caused by feed medication in swine

Giving medical feed to weanling pigs it is possible to produce a vitamin K-deficiency as a side effect, which is caused by destruction of the intestinal flora. In this investigation the effect of different drugs in a vitamin K-deficient diet on blood coagulation of weanling pigs was examined. In a first trial clinical symptoms of a vitamin K-dependent coagulation disorder could be seen in five from six animals after feeding a combination of sulfadimidine, tylosin, furazolidone and arsanilic acid. Animals showed haemorrhages, when they were housed on flatdecks as well as on concrete floor. This indicated that coprophagy plays no role in pigs for supply of vitamin K. Feeding these drugs in other combinations or one of the drugs alone caused no clinical signs in a second trial. Significant differences to untreated control pigs were found only in one group (sulfadimidine/arsanilic acid) for activities of coagulation factors. Other groups demonstrated only prolongation of clotting times in single animals. Pigs, which received sulfadimidine within their ration, were more often affected than other animals. In a third trial suckling pigs were treated over a period of three weeks with a drug combination used in the first trial to allow an adaptation of the intestinal flora. Same treatment after weaning was unable to produce any clinical symptoms, but led to distinct coagulation disorders in pigs treated before as well as in untreated animals. It is supposed that the development of a vitamin K-deficiency depends on faecal bacterial count and on the specific resistance of intestinal flora in individuals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tryptophan Metabolism in Pigs: Relation to Synthesis and Function of Serotonin

Contrary to blood serotonin the level of free and total tryptophan is distinctly influenced by feed intensity and composition. Piglets show a considerably higher plasma free tryptophan and blood serotonin content than adult pigs, just as boars possess a significantly higher blood level of tryptophan and serotonin than sows. A pronounced individual variation of blood serotonin and a much less variable content among littermate pigs provide evidence that blood serotonin is genetically controlled. Tryptophan is readily absorbed and distributed in a characteristic manner among investigated organs and tissues. A genetical control of blood serotonin and its possible relation with type of reaction exhibited by ergometer exercised pigs support the influence of tryptophan and serotonin on the ability of pigs to withstand controlled environmental conditions such as physical exercise.