鸡马立克氏病与白血病混合感染的实验室诊断

鸡马立克氏病(Marek's disease,MD)是鸡的一种淋巴组织增生性疾病,以外周神经、性腺、虹膜、各内脏器官、肌肉和皮肤等单个或多个组织器官发生单核细胞浸润为特征。本病是由细胞结合性疱疹病毒引起的传染性肿瘤病,病鸡常见消瘦、肢体麻痹,并常有急性死亡。     

一例鸡马立克氏病与沙门氏菌病混合感染的实验室诊断

为确诊思南县某养殖专业合作社饲养的肉鸡发病死亡原因,采集病鸡羽髓、血样及病死鸡肝脏、脾脏进行细菌分离培养、相关病毒琼脂扩散试验和PCR检测。结果:肝脏组织中分离出沙门氏菌;羽髓琼脂扩散试验检测出马立克氏病抗原,血清琼脂扩散试验检测出马立克氏病抗体;肝脏、脾脏PCR检测出马立克氏病病毒核酸。结论:综合诊断为马立克氏病与沙门氏菌病混合感染。     

绵马贯众可溶性粉对人工感染鸡传染性法氏囊病的疗效评价

通过建立人工感染鸡传染性法氏囊病病毒(IBDV)模型,本试验旨在验证绵马贯众可溶性粉对IBDV的治疗效果。试验将95只21日龄的SPF鸡随机分为7组,包括绵马贯众可溶性粉高(198 mg/kg)、中(99 mg/kg)、低剂量组(50 mg/kg)及朝鲜绵马贯众组(99 mg/kg)、黄芪多糖组(99 mg/kg)、感染对照组(染毒不给药)和健康对照组。以IBDV LX毒株经鼻腔感染36 h后,连续口服以上药物5 d,评价其增重率、治愈率、成活率和免疫器官指数。结果显示:①人工感染IBDV后,绵马贯众可溶性粉中、低剂量组相对增重率均极显著高于朝鲜绵马贯众组(P<0.01),绵马贯众可溶性粉低剂量组显著高于绵马贯众可溶性粉中剂量组和黄芪多糖组(P<0.05),且绵马贯众可溶性粉中剂量组与黄芪多糖组相比差异不显著(P>0.05);②绵马贯众可溶性粉高、中、低3个剂量组成活率分别为80%、80%和73.3%,均显著高于朝鲜绵马贯众组(66.7%)、黄芪多糖组(53.3%)和感染对照组(60.0%)(P<0.05);其相对应的治愈率也均显著高于朝鲜绵马贯众组和黄芪多糖组(P<0.05)。③在胸腺指数、脾脏指数方面,绵马贯众可溶性粉中、低剂量组与朝鲜绵马贯众组、黄芪多糖组相比差异均不显著(P>0.05),但显著高于感染对照组(P<0.05);法氏囊指数差异均不显著(P>0.05)。结果显示绵马贯众可溶性粉以50 mg/kg连续口服5 d,通过提高胸腺指数和脾脏指数而发挥免疫增强功效,有效治疗人工感染鸡传染性法氏囊病,且成活率和治愈率均高于黄芪多糖。     

Laboratory Efficacy of Amoxicillin for the Control of Streptococcus iniae Infection in Blue Tilapia

Abstract

Experimental feeding trials were performed to evaluate the efficacy of amoxicillin (AMX) in controlling Streptococcus iniae infection in blue tilapia Oreochromis aureus. The doses of AMX active ingredient tested were 0, 5, 10, 30, and 80 mg/kg of fish body weight (BW) per day. Administration of medicated feed started within 22–24 h postchallenge by waterborne exposure to S. iniae (after skin scraping) and continued for 12 consecutive days, followed by a 17-d posttreatment observation. Oral administration of AMX-medicated feed for 12 d at a daily rate of 10, 30, and 80 mg/kg BW significantly increased the survival of S. iniae?infected tilapia from 3.8% in the challenged, nonmedicated positive control to 45, 75, and 93.8%, respectively. The survival rate was significantly higher in the 80-mg treatment (93.75%) than the 10-mg treatment (45%) but did not differ significantly between the 10-mg (45%) and 30-mg (75%) treatments. At the conclusion of the experiment, no carriers were detected in any challenged group receiving AMX-medicated diet, whereas the bacterium was recovered from the nonmedicated, challenged survivors of the infection.     

孔雀新城疫病毒与大肠杆菌混合感染的诊断

从1只病死孔雀的肝、脾及脑组织悬浊液中分离到1株病毒,经HA和HI试验、病毒中和试验及荧光PCR试验,证明该病毒为新城疫病毒。取其肝及心血做细菌分离培养,经革兰氏染色、镜检及各多种生化试验鉴定为大肠杆菌,动物试验结果证明其具有致病性。由此说明,该孔雀死于新城疫和大肠杆菌混合感染。     

Spatial and Temporal Variation of Whirling Disease Risk in Montana Spring Creeks and Rivers

Abstract

Spring creeks are important spawning and rearing areas for wild trout, but the stable flows, cool temperatures, and high nutrient levels that characterize these unique habitats may also make them highly susceptible to establishment and proliferation of the whirling disease pathogen Myxobolus cerebralis. We evaluated the spatial and temporal dynamics in whirling disease risk by using sentinel rainbow trout Oncorhynchus mykiss fry in nine different spring creeks and their conjoining rivers or reservoirs in Montana over a 20-month period. Whirling disease risk was high in five of the seven pathogen-positive spring creek study sites; at these sites, prevalence levels exceeded 90% and over 50% of sentinel fry had moderate to high infection severity scores. Spring creeks generally had higher disease prevalence and severity than paired river or reservoir sites. Fine sediment levels varied widely among springs creeks with high and low whirling disease risk, and we found no significant association between fine sediment level and infection severity. The low risk measured for some spring creeks was likely attributable to the pathogen invasion being in its early stages rather than to environmental characteristics limiting the severity of infection. High whirling disease risk occurred over a wide range of temperatures at spring creek sites (4.5–13°C) and river sites (1.7–12.5°C). There was an unusual seasonal cycle of infection in spring creeks, with peak infection levels occurring from late fall to early spring and declining to near zero in late spring to early fall. The low infection risk during spring suggests that spring-spawning trout would be at a low risk of infection, even in spring creeks with otherwise high disease severity. In contrast, fry of fall-spawning trout may be much more susceptible to infection in spring creek environments.

Received November 22, 2011; accepted May 7, 2012     

马疱疹病毒1型感染马疾病模型的建立及评价

试验旨在建立马疱疹病毒1型（Equine herpesvirus type1,EHV-1）人工发病模型,确定EHV-1感染马的半数感染量（ID₅₀）及感染发病的判定标准,为该病的预防与治疗药物的研发奠定基础。以新疆伊犁地区某发病马场流产胎儿中分离的EHV-1 XJ2015株为研究对象,设立4组不同病毒剂量感染组及对照组,经鼻内喷雾感染马,5 mL/匹,每天观察试验马的临床症状和发病情况,14 d后进行剖检,观察各组织脏器病理变化并应用实时荧光定量PCR方法检测鼻腔排毒及病毒分布情况。结果显示,EHV-1 XJ2015株感染马的ID₅₀为10^-6.67/5 mL,其病毒含量为10^4.33 TCID₅₀/mL。与对照组相比,1×10⁶和1×10⁵ TCID₅₀/mL感染组马临床评分显著升高,主要表现为体温升高（高达39.5 ℃,一般持续2~6 d）、食欲不振、流浆液性鼻液和下颌淋巴结肿大;且1×10⁶和1×10⁵ TCID₅₀/mL感染组试验马均表现出不同程度的排毒,肺脏及脑组织中可检测出大量病毒,与对照组相比极显著或显著升高（P<0.01;P<0.05）;病理学检查发现,患马脑组织出现非化脓性脑炎及神经元水肿,肺脏组织出现间质性肺炎、嗜中性粒细胞、炎性细胞浸润、出血和肺泡间隔增厚。以上结果表明,EHV-1 XJ2015株对马具有较强的致病性,患病马临床症状典型,病毒主要随鼻液排出,并富集在肺脏及脑组织,通过上述指标确定EHV-1感染马发病的判定标准,本试验成功建立EHV-1感染本体动物疾病模型。     

禽白血病病毒感染对新城疫和禽流感疫苗免疫效果的影响

为研究禽白血病病毒(ALV)感染对新城疫(ND)和禽流感(AI)疫苗免疫效果的影响,采用ELISA方法对河南省某地方品种鸡场进行ALV-p27抗原检测,同时采集试验鸡的血清样品,检测ND、AI(H_9)和AI(H_5)亚型的免疫抗体水平,并比较了ALV经种蛋垂直传播感染1日龄雏鸡和后期感染对ND、AI疫苗免疫效果影响的差异。结果表明,ALV经种蛋垂直传播感染1日龄雏鸡,能显著降低ND、AI(H_9)和AI(H_5)疫苗免疫的抗体水平,阳性试验组与阴性组相比血清中ND、H_9、H_5(Re-6)、H_5(Re-7)和H_5(Re-8)抗体效价分别降低1.71log2、2.37log2、1.59log2、1.00log2和1.79log2;鸡群后期感染ALV,对ND和AI疫苗的免疫没有明显的抑制作用,阳性试验组与阴性组相比无显著差异。     

Treatment of Hepatozoon americanum Infection: Review of the Literature and Experimental Evaluation of Efficacy

There is no labeled treatment for dogs with American canine hepatozoonosis (ACH), but the drug therapies discussed in this article, although not rapidly curative, may be successful in alleviating acute clinical signs, prolonging life, reducing the number of clinical relapses, and enhancing quality of life. This article also describes a pilot trial conducted to assess the efficacy of a novel treatment approach with ponazuril as a stand-alone parasiticide administered for 4 weeks without follow-up decoquinate treatment. Although extended ponazuril treatment in combination with NSAID administration did ameliorate acute clinical signs associated with ACH, the parasite was not completely cleared with this treatment protocol alone. Long-term decoquinate therapy remains a critical component of successful treatment of ACH.     

PRRSV、CSFV混合感染病例的实验室诊断

为确诊贵阳市某猪场疑似猪繁殖与呼吸障碍综合征(PRRS)死亡病例,对死亡猪进行剖检及实验室诊断。病理剖检可见,病死猪出现淋巴结肿大充血、肺部有坏死灶、胸腔有大量积液等病理变化;同时采集病理组织应用分子生物学和细菌学方法进行PRRSV(普通毒株和Nsp2变异毒株)、猪瘟病毒核酸检测和细菌分离鉴定。结果显示:该病例为PRRSV(普通毒株)、CSFV混合感染所致。     

实验动物微生物学质量控制及效果观察

以SPF级（无特殊病原体）动物为种源，采取综合防治措施，在屏障设施饲养清洁级实验小鼠和大鼠。经过两年饲养繁育的结果表明：动物微生物学质量符合清洁级动物国家标准，质量控制效果显著。     

持续感染黄牛体内口蹄疫病毒抗原性和血清中和特性分析

以口蹄疫病毒O/Akesu/58毒株感染黄牛获得口蹄疫病毒持续带毒动物,定期分离黄牛食道/咽喉部黏性液体（O/P液）和血清,研究病毒分离毒株抗原基因变异及其血清中和特性,从基因水平和血清学方面研究口蹄疫病毒持续感染分离株的抗原变异性。用RT-PCR扩增分离株抗原基因VP1,分析VP1基因变异情况;用微量血清中和试验检测了口蹄疫病毒持续感染血清与对应动物分离毒株的中和特性,并用液相阻断ELISA方法检测了口蹄疫病毒持续感染血清的抗体水平变化,并对其相关性进行了分析。结果发现所有持续感染分离毒株的VP1基因核苷酸和氨基酸同源性都在98%以上,没有碱基缺失或插入现象;与O/Akesu/58的核苷酸同源性仅为85%左右,氨基酸同源性也仅为90%。持续感染分离株VP1基因有多处位点发生突变,其中有16个核苷酸位点发生一致突变,但只有2个位点造成氨基酸突变（I 56→T、A 210→E）;而持续感染分离毒株有4个核苷酸位点和3个氨基酸位点发生了颠换突变;同时证实不同时间分离株与对应血清都能相互中和,且中和作用能力随着时间延续呈下降趋势,最低为1∶80,具有较强的中和能力,这与LPB-ELISA检测结果基本一致。这说明口蹄疫病毒持续感染分离株抗原变异不显著,没有变异到动物自身血清不能识别的程度,而且分离毒株与自身动物血清具有较强的中和特性;在持续感染过程中,动物血清保持高水平抗体滴度,且持续感染毒株的分离与否与抗体水平没有显著相关性。     

牛附红细胞体病与寄生虫病混合感染诊治

人们对肉类食物的需求量不断增加,为满足社会饮食的需求,我国大力发展畜牧养殖业,大规模养殖业的发展满足了社会的需求。其中牛养殖业的占比量较大,牛养殖业的规模化发展满足了市场对牛肉的需求,但随着牛养殖业全面发展,牛附红细胞体病和寄生虫病的发病率越来越高,影响牛群体的正常生长发育,对牛养殖业的发展产生非常大的负面影响。为促进牛养殖业的可持续发展,该文针对牛附红细胞体病和寄生虫病的临床症状、检查、预防和治疗进行深入分析,为促进我国牛养殖业的规模化发展起到推动作用。     

牛支原体与附红细胞体混合感染病例的实验室诊断

为查明贵州省安顺市某养殖场牛群发病死亡的原因,采集病料进行支原体核酸检测、血液原虫检查以及细菌分离培养.结果:肺脏样品PCR扩增出351 bp的牛支原体目的基因条带,血液样品姬姆萨染色镜检观察到大量附红细胞体,未分离培养出细菌.结论:根据病牛临床症状、病理变化和实验室检测结果,确诊为牛支原体与附红细胞体混合感染.     

家蚕传染病的流行与控制

本文根据养蛋与家蚕传染病的特点,分析了影响家蚕传染病流行的宏观因素,提出了相应的防控措施及思考.     

The Effects of Whirling Disease on Growth and Survival of Snake River Cutthroat and Colorado River Rainbow Trout Fingerlings

Abstract

Two sizes of fingerling Snake River cutthroat trout Oncorhynchus clarkii behnkei and Colorado River rainbow trout O. mykiss were raised at hatcheries testing negative for Myxobolus cerebralis and stocked into the Dolores and Cache la Poudre rivers from 1999 to 2001. Populations were resampled over a 2-year period to determine which species and size combination had the highest growth and survival rates. Fish were tested for M. cerebralis via polymerase chain reaction and pepsin?trypsin digest analyses. Growth and survival rates between the species and size groups were not significantly different in either river. In the Dolores River, annual survival for both species and sizes of fish combined ranged from 0.063 to 0.12. In the Cache la Poudre River, survival for both sizes of rainbow trout was 0.004; survival for cutthroat trout ranged from 0.182 to 0.53. Larger fish had higher growth rates than smaller fish, and cutthroat trout had higher rates than similar sizes of rainbow trout. In both rivers, a higher percentage of the rainbow trout sample was infected than in the cutthroat trout sample. Rainbow trout also had a higher mean number of spores per head than cutthroat trout, and small rainbow trout had higher spore counts than large rainbow trout. Survival rates for cutthroat trout in the Cache la Poudre River were the highest of any of the groups, suggesting a difference that is biologically significant. Raising fingerlings to sizes greater than 100 mm can improve poststocking survival. If rainbow trout are stocked into contaminated waters, raising fingerlings to a larger size does not appear to improve growth or survival rates. Stocking rainbow trout in the spring could maximize growth rates but will expose fish to greater triactinomyxon densities, resulting in higher intensities of infection.     

鸡马立克氏病的诊断与防治

贵州省某鸡场送检发病鸡6只,根据流行病学、剖解病变疑似马立克氏病,经肝脏进行细菌分离培养24 h后观察无细菌生长,琼脂扩散试验为阳性,马立克氏病毒核酸的PCR检测能扩增出目的条带,表明该病为马立克氏病病毒感染所致。