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1.
１日龄ＳＰＦ来航鸡经口双重感染鸡贫血病病毒（ＣＡＶ）Ｃｕｘ－１株及鸡呼肠病毒（ＲＥＯＶ）Ｓ１１３３或Ｕｃｈｉｄａ株。于接种后第１４天，检查血细胞压积（ＰＣＶ）、称体重、观察骨髓、胸腺及法氏囊病变。结果，双重感染ＣＡＶ及Ｓ１１３３株ＲＥＯＶ的雏鸡与感染其中之一病毒的雏鸡相比，其体重增重少，病变重，而且比仅感染ＣＡＶ的雏鸡在平均ＰＣＶ上也明显低。双重感染ＣＡＶ及Ｕｃｈｉｄａ株ＲＥＯＶ的雏鸡，不加重发病 相似文献
2.
在中国鸡痘病毒２８２Ｅ４弱毒株基因组部分ＢａｍＨＩ片段的质粒ｐＵＢ、ｐＵＣ、ｐＵＤ、ｐＵＤ２、ｐＵＥ和ｐＵＦ酶切分析的基础上,对ｐＵＦ进行了亚克隆获得ｐＵＦ－Ｅ和ｐＫＳ－Ｘ,对最可能存在非必需区的ｐＵＥ质粒进行了序列分析,改造了含Ｐ１１Ｐ７．５－ＬａｃＺ报告基因盒,并在上述质粒的相应单一酶切位点插入Ｐ１１Ｐ７．５－ＬａｃＺ报告基因盒,构建成ｐＵＢ１、ｐＵＦＣ１、ｐＵＦＥ１、ｐＵＦ－Ｅ１和ｐＫＳＦ－Ｘ１５个重组载体质粒。体内重组等工作正在进行中。 相似文献
3.
猪生殖和呼吸综合征中国分离株ORF7基因的克隆及鉴定 总被引：2，自引：0，他引：2
本研究利用对应于ＡＴＣＣＶＲ－２３３２及ＬＶＯＲＦ７基因保守序列的１对均为２８个碱基的引物１００１１ＰＣＳ、１０１０ＰＣＲ对ＰＲＲＳＶ中国分离株Ｂ１３进行ＲＴ－ＰＣＲ，结果扩增出了１条包括完整ＯＲＦ７基因的５１０ｂｐ的ＤＮＡ片段。纯化此扩增产物，并对其进行ＥｃｏＲＩ／ＰｓｔＩ双酶切，与用ＥｃｏＲＩ、ＰｓｔＩ双酶切及碱性磷酸酶处理的ＰＵＣ１８载体连接。转化大肠杆菌。结果得到了１个Ｂ１３ＯＲＦ７基因与ＰＵＣ１８载体的重组质粒ＰＵＣ１８Ｂ１３ＯＲＦ７１０。通过ＥｃｏＲＩ／ＰｓｔＩ及ＰＣＲ证明此重组质粒即为Ｂ１３ＯＲＦ７基因与ＰＵＣ１８载体的重组质粒。从而为ＯＲＦ７基因及所表达的核衣壳蛋白进一步研究奠定了基础。 相似文献
4.
黄芪多糖和香菇多糖对vMDV感染雏鸡淋巴细胞化学发光的影响 总被引：5，自引：1，他引：4
１日龄雏鸡人工感染ｖＭＤＶ，并注射黄芪多糖（ＡＰＳ）和香菇多糖（Ｌｅｎ），分别于７、１６、２８、４２和５６日龄检测雏鸡淋巴细胞化学发光（ＣＬ）的变化。结果表明：（１）ＡＰＳ对７、１４日龄ｖＭＤＶ感染雏鸡胸腺、脾脏和法氏囊淋巴细胞的ＣＬ有显著抑制作用（ｐ〈０．０５，ｐ〈０．０１），在２８、４２日龄则显著增强淋巴细胞ＣＬ（ｐ〈０．０５，ｐ〈０．０１）；（２）Ｌｅｎ对７、１４日龄ｖＭＤＶ感染雏鸡胸腺、脾 相似文献
5.
用单克隆抗体鉴定猪繁殖与呼吸综合征病毒分离株 总被引：9，自引：0，他引：9
应用ＰＲＲＳＶ单克隆抗体,采用直接与间接免疫荧光抗体试验对分离获得的ＰＲＲＳＶ６个毒株进行了鉴定,结果所有分离毒株均能被单克隆抗体（ＳＤＯＷ１７、Ａ、Ｂ、Ｃ、Ｄ、Ｅ、Ｆ）所识别,呈现特异荧光,６个分离毒株均能与仅识别美洲型ＰＲＲＳＶ的单克隆抗体Ｆ反应,结果表明６个分离毒株均属于美洲型ＰＲＲＳＶ。利用微量细胞培养对分离毒株ＴＣＩＤ５０测定结果表明,６个分离毒株的ＴＣＩＤ５０分别为１０－７．５／０．１ｍｌ、１０－７．５／０．１ｍｌ、１０－７．５／０．１ｍｌ、１０－７．７５／０．１ｍｌ、１０－７．２５／０．１ｍｌ、１０－６．２５／０．１ｍｌ。病毒感染细胞的超薄切片电镜观察表明,在感染细胞浆内可见典型的ＰＲＲＳＶ病毒粒子,呈球形或椭圆形,直径约为６０ｎｍ左右,可见囊膜。 相似文献
6.
氯霉素间接竞争ELISA(ciELISA)检测方法的建立 总被引：3，自引：0，他引：3
以人工合成的氯霉素－牛血清白蛋白（ＣＡＰ－ＢＳＡ）为包被抗原,氯霉素（Ｃｈｌｏｒａｍｐｈｅｎｉｃｏｌ,ＣＡＰ）为竞争的半抗原,两者与一定量的抗ＣＡＰ单抗（ＣＡＰ－ＭｃＡｂ）反应。实验结果表明,理想的包被抗原浓度为１．２５μｇ／ｍｌ,抗ＣＡＰ－ＭｃＡｂ工作浓度为１：１２０００,酶标二抗工作浓度为 １： ５０００,可测最适范围为 １ｎｇ／ｍｌ－１００ｎｇ／ｍｌ,最小检测量为０．１ｎｇ／ｍｌ,批内和批间变异系数分别为３． ６２％和 ５． １９％。得到回归方程 ｙ ＝１．２７３０－ ０．６７４５ｘ（ｒ２＝ ０． ９７７９）和标准曲线,从而建立了快速定量测定 ＣＡＰ含量的间接竞争酶联免疫吸附试验（ＥＬＩＳＡ）。整个测定时间为６小时。 相似文献
7.
8.
猪流行性腹泻病毒适应Vero细胞培养及以传代细胞毒制备氢氧化铝灭活疫苗免疫效力试验 总被引：4，自引：0，他引：4
采用在病毒培养液中加５～１０μｇ／ｍｌ胰酶的培养方法，将猪流行性腹泻病毒（ＰＥＤＶ）ＣＶ＿（７７７）适应于Ｖｅｒｏ细胞，并传４５代．细胞病变规律．经免疫荧光检查阳性，电镜观察可见典型冠状病毒粒子，猪传染性胃肠炎（ＴＧＥ）免疾荧光检查阴性，猪流行性腹泻（ＰＥＤ）血清可抑制细胞病变（ＣＰＥ）．ＰＥＤＶＣＶ＿（７７７）毒株１１、２５、２８、４０及４４代传代毒的毒价分别为１０￣（３．５）、１０￣（５．５）、１０￣（６．５）、１０￣（７．０）和１０￣（７．０）ＴＣＩＤ＿（５０）／０．３ｍｌ。以１１、２１及２２代的毒１０ｍｌ头口服接种未吃初乳仔猪，可使之典型发病，免疫荧光及电镜观察均呈阳性．分别以２５、２８及３１代毒０．５ｍｌ／头、１ｍｌ／头、２ｍｌ／头口服接种３日龄仔猪１８头．除０．５ｍｌ组有１头反应外，均未发病，攻毒试验的总保护率为８７．５％，对照组１００％发病．以２８代毒制备氢氧化铝灭活苗，后海穴位接种，主动免疫组８５．１９％保护，被动免疫组８５％保护，对照组１００％及９２．３％发病． 相似文献
9.
腺胃病变型鸡传染性支气管炎病毒的分离鉴定 总被引：36，自引：8，他引：28
从１９９７年在辽宁省大连市某鸡场发生的一种以腺胃肿大为特征的鸡的传染病病例中收集腺胃组织（Ｄ９７１）接种ＳＰＦ鸡胚,传至１３代,具有规律性死亡和典型胚胎病变特征,ＥＩＤ５０为１０－６．４８／０．２ｍｌ。Ｄ９７１毒株感染ＳＰＦ鸡胚尿囊液经负染电镜观察,可见直径为８０～１２０ｎｍ,有囊膜和纤突的冠状病毒粒子。Ｄ９７１毒株经卵磷脂酶Ｃ处理后能凝集鸡红细胞,并能特异的被Ｄ９７１多抗所抑制。用反转录聚合酶链反应获得了Ｄ９７１毒株免原（Ｓ１）基因ｃＤＮＡ,经１％琼脂糖凝胶电泳可见１．７ｋｂ的特征性条带。用Ｄ９７１毒株接种ＳＰＦ鸡,能引起与自然病例相似的病理变化,并分离到病毒。用Ｄ９７１毒株可直接感染ＳＰＦ鸡胚成纤维细胞。结果证实从腺胃病变型ＩＢ鸡群中分离的Ｄ９７１毒株是冠状病毒科ＩＢＶ成员。 相似文献
10.
对鸡新城疫病毒（ＮＤＶ）中等毒力毒株ＣＳ２株、ＮＤⅠ系、Ｒｏｋｉｎ、Ｋｏｍｅｒｏｖ和低毒力ＬａＳｏｔａ株病毒的脑内致病指数（ＩＣＰＩ）、鸡胚的半数感染量（ＥＩＤ５０）等指标进行了测定,结果是ＩＣＰＩ分别为１．２７～１．５２、１．６６～１．７０、１．４６、１．４３和０．２９～０．５;ＥＩＤ５０分别为１０＾７．５、１０＾７．５≥１０＾８．５、１０＾＾７．９和≥１０＾８．５／０．１ｍｌ。用１０倍剂量的ＣＳ２株病毒注射１月龄和１．５月龄ＳＰＥ雏鸡,均安全无不良反应,测定ＣＳ２株病毒保存期,结果在－２０℃保存６年的鸡胚２代（Ｅ２）、鸡胚６代（Ｅ６）、鸡胚１０代（Ｅ１０）毒的ＥＩＤ５０均≥１０＾７．５／０．１ｍｌ。ＮＤＣＳ２株病毒的各项指标均在中等毒力范围内,对鸡胚的半数感染量仍保持原毒（Ⅰ系）的特性,ＩＣＰＩ比原毒有所下 相似文献
11.
Day-old, straight-run broiler chickens were procured from a hatchery located in the Pacific Northwest. The chickens were subdivided individually into nine groups of 20 chickens. The chickens were tagged, housed in isolation chambers on wire, fed commercial broiler feed, and given water ad libitum. Three isolates of Campylobacter jejuni of poultry origin and one of human origin were tested in this study. Various C. jejuni cultures were inoculated into 9-day-old chickens by crop gavage. Four groups of 20 chickens were inoculated at a dose level of 0.5 ml of 1 x 10(2) colony-forming units (CFU)/ml. The other four groups were inoculated with 0.5 ml of 1 X 10(4) CFU/ml. One group of 20 chickens was kept as an uninoculated control group. Four randomly selected chickens from each of the inoculated and uninoculated groups were necropsied at 5, 12, and 19 days postinoculation (DPI). The C. jejuni was cultured and enumerated from a composite of the upper and midintestine and the cecum. Body weights of all chicken groups at 7 days of age and at 5, 12, and 19 DPI were measured and statistically analyzed. No significant differences were present in the mean body weights (MBWs) of 7-day-old, 5 DPI, and 12 DPI male and female broiler chickens inoculated with C. jejuni at both dose levels compared with uninoculated controls. Differences in MBWs of the male and female broilers at 19 DPI were observed in some of the groups. Results of the C. jejuni culture enumeration mean (CEM) of composite intestine samples at 5 DPI from all inoculated chicken groups, irrespective of the dose level, ranged from (2.5 +/- 5.0) x 10(2) to (2.8 +/- 4.8) x 10(5) CFU/g (mean +/- SD). Results of cecum C. jejuni CEM at 5 DPI inoculated at both dose levels ranged from (2.5 +/- 5.0) x 10(6) to (1 +/- 0.0) x 10(7) CFU/g in all treatment groups irrespective of the dose level. CEM results from the composite intestine samples at 12 and 19 DPI increased by 1 log unit, or sometimes more. Results of cecum C. jejuni CEM at 5 DPI inoculated at both dose levels ranged from (2.5 +/- 5.0) x 10(6) to (1 +/- 0.0) x 10(7) CFU/g in all treatment groups irrespective of the dose level. Increases of 2-5 log units in C. jejuni CEM was present in chicken groups inoculated with 1 X 10(2) CFU of C. jejuni, and a 2- to 3-log increase was present in groups inoculated with a higher dose level of C. jejuni at 12 DPI. The results of C. jejuni CEM from cecal samples at 19 DPI were similar to chicken groups at 12 DPI. Campylobacterjejuni was not isolated from the uninoculated control chickens at 5, 12, and 19 DPI. Clinical signs of illness or gross pathologic lesions were not present in any of the chicken groups during this study. No lesions were present on histopathologic evaluations in C. jejuni-inoculated chickens or uninoculated control chickens. 相似文献
12.
Effects of probiotics and maternal vaccination on Salmonella enteritidis infection in broiler chicks
The effects of probiotics and maternal vaccination with an inactivated Salmonella Enteritidis (SE) vaccine on day-old chicks challenged with SE were evaluated. A 2 X 3 factorial arrangement was used (with or without probiotics; breeders nonvaccinated, vaccinated intramuscularly, or vaccinated intraperitoneally). Three trials were conducted in isolation cabinets and SE challenge was different between trials. The number of SE organisms per chick and the time interval between housing and introduction of seeder birds (hereafter called challenge) were 1.6 X 10(8) and 1 hr (Trial I), 1.8 X 10(6) and 12 hr (Trial II), and 1.2 X 10(4) and 24 hr (Trial III). SE recovery was assessed in ceca and liver at 3, 5, and 7 days postchallenge, and the number of colony-forming units (CFU) in ceca was evaluated at 5 and 7 days postchallenge. The number of SE (log CFU) in the ceca reduced 0.56 log (from 7.59 to 7.03) and 1.45 log (7.62 to 6.17) because of the treatment with probiotics in Trials II and III, respectively. The greater reduction in Trial III indicates the importance of the early use of probiotics on the prevention of SE infection. Treatment with probiotics resulted in a smaller number of SE-positive livers after 5 days postchallenge on Trial III. Although there was no significant effect of maternal vaccination on the number of SE CFU in the ceca, a significant effect of maternal vaccination on the SE CFU was observed in the liver, but not in the ceca at 5 days after challenge. 相似文献
13.
Campylobacter jejuni in poultry giblets 总被引：1，自引：0，他引：1
F A Khalafalla 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1990,37(1):31-34
A total of 200 poultry giblets, 50 each of chickens, ducks, squab and turkeys, were examined for the presence of Campylobacter jejuni. In chicken giblets, C. jejuni was isolated from gizzards, hearts, livers and spleens with incidences of 28%, 10%, 40% and 16% respectively while 24%, 6%, 36% and 10% of duck gizzards, hearts, livers and spleens were positive for the organism, respectively. C. jejuni was detected in 6% of squab gizzards, in 10% of squab livers but failed to be detected in squab hearts & spleens. In turkey giblets, 16% of gizzards, 4% of hearts, 30% of livers and 8% of spleens were positive for the organism. C. jejuni was more frequently isolated from liver samples than gizzard, spleen and heart samples, each constituting of 29%, 18.5%, 8.5% and 5%, respectively. High incidence of C. jejuni was recorded among chicken giblets (23.5%), followed by duck giblets (19%), then turkey giblets (14.5%) and finally squab giblets (4%). 相似文献
14.
We report our findings on several parameters influencing cecal colonization of chickens by Campylobacter jejuni. Thirty-five colony-forming units (CFU) of a composite culture of C. jejuni colonized the ceca of one-half of the newly hatched chicks challenged by oral gavage. A challenge dose of 3500 CFU/chick consistently colonized the ceca of all chicks challenged. Challenge doses of approximately 10(5) CFU of C. jejuni per chick resulted in consistent cecal colonization, regardless of whether the birds were challenged 1, 2, or 3 days post-hatch. Four isolates showed consistently strong cecal colonization abilities, whereas two isolates colonized the ceca in only 20 of 122 chicks when given levels of 10(5) CFU per chick. One of these poorly colonizing isolates was repeatedly transferred by fecal-oral passage through chicks; subsequently, this isolate was able to consistently colonize chicks. Competitive exclusion (CE) microflora did not diminish the colonization rates for C. jejuni. Birds treated with five different CE cultures were colonized at a rate of 81 of 84 chicks; control chicks were similarly consistently colonized (45 of 46 chicks). 相似文献
15.
Radappertized chicken drumsticks were experimentally contaminated with suspensions of Campylobacter jejuni in two trials. Qualitative analysis on drumsticks with an initial level of contamination of 4.8 X 10(3) CFU/cm2 showed that viability was retained for at least 10 days of storage at either 9 degrees or -12 degrees C. In a second quantitative trial, the level of contamination declined from 9.9 X 10(2) CFU/cm2 to 4.5 X 10(1) CFU/cm2 after 7 days at -20 degrees C. Thereafter, C. jejuni persisted at levels ranging from 1.8 X 10(1) to 0.2 X 10(1) CFU/cm2 through the 26th week of storage. Drumsticks held at 4 degrees C showed a significant decline in count from 9.9 X 10(2) CFU/cm2 to 1.8 X 10(2) CFU/cm2 on day 7. It is concluded that the viability of C. jejuni on chicken parts is maintained under both refrigerated and freezing conditions which approximate commercial storage. This is of significance to the meat industry and consumers. 相似文献
16.
核糖核酸酶RnaseⅢ是一种调控nc RNA水平的重要酶系。为了解核糖核酸酶RnaseⅢRncS在单核细胞增生李斯特菌(LM)毒力中的调控作用,本研究在构建LM-ΔrncS基因缺失突变株的基础上,通过动物感染试验检测强毒株LM-SB5与缺失株LM-Δrnc S对昆明系小鼠的LD50、存活能力、脏器载菌量及病理组织学产生的影响;利用细胞侵染试验检测强毒株与缺失株对小鼠巨噬细胞RAW264.7的粘附率、侵袭率及其在胞内生存繁殖能力的影响,分析RnaseⅢRncS对LM毒力的影响。结果显示,LM-SB5强毒株和LM-Δrnc S缺失株对昆明系小鼠的LD50分别为105.60 CFU、106.90 CFU;与LM-SB5强毒株相比,LM-Δrnc S的LD50升高了1.30个对数数量级,小鼠的存活时间明显延长,表明毒力显著降低;第3~5 d肝脏、脾脏载菌量显著减少(P<0.05),其中第4 d差异极显著(P<0.01);LM-Δrnc S缺失株对肝脏、脾脏、肾脏的病理损伤降低;LM-Δrnc S缺失株对RAW264.7细胞的粘附率和侵袭率均显著低于LM-SB5强毒株(P<0.01),在2~6 h之间,LM-Δrnc S缺失株在细胞内的细菌量显著低于LM-SB5强毒株(P<0.05),证实LM-Δrnc S在细胞内的生存增殖能力显著降低,提示rnc S基因对LM毒力发挥有一定的调控作用。本研究为进一步揭示RnaseⅢ在LM毒力中的分子调控机制提供了科学依据。 相似文献
17.
T Farkas C Drén I Németh M Dobos-Kovács J Povazsán E Sághy 《Acta veterinaria Hungarica》1992,40(3):207-223
Chicken anaemia virus (CAV) infection was demonstrated, by both serology and virus isolation, in 1- to 6-week-old broiler chickens originated from various parent flocks in Hungary. Total losses in the broiler flocks were estimated at 7 to 8% and about 25% of the chickens failed to reach target body mass by the 7th week of life. The clinical signs, postmortem lesions and histopathological changes of the affected chickens were similar to those of naturally occurring CAV-induced infectious anaemia of young chickens. In MDCC-MSB1 cell cultures, a chloroform-resistant virus smaller than 50 nm in diameter, resistant to heating at 70 degrees C for 30 min, and antigenically very closely related to the Cux-1 strain of CAV was isolated from the liver of naturally diseased broilers. This virus isolate was designated the Bia strain of CAV. Inoculation of susceptible 1-day-old SPF chicks with a CAV-positive liver extract from naturally diseased broilers caused pathological changes characteristic of CAV infection, namely impaired growth, severe anaemia with atrophy of the bone marrow, marked atrophy of the lymphoid organs and petechial haemorrhages throughout the body. A quite similar pathological syndrome was also induced by inoculation of 1-day-old SPF chicks with the MDCC-MSB1 cell-culture-propagated new Bia strain of CAV. The CAV was successfully reisolated from the livers of experimentally inoculated birds, and antibodies to the reference Cux-1 strain of CAV were also demonstrated by the indirect immunofluorescence test in sera of naturally diseased and experimentally inoculated chickens. No antibodies were found against infectious bursal disease virus, reticuloendotheliosis virus, Marek's disease herpesvirus as well as avian adenoviruses and reoviruses. The reported disease of young broiler chickens was associated with natural infection of a new isolate of CAV. On the basis of its physicochemical, antigenic and pathogenic characteristics, this virus is similar to other strains of CAV isolated from chickens in other countries. 相似文献
18.
White Leghorn chicks used in this study were hatched from specific pathogen-free eggs. The colonizing capability of Campylobacter (C.) jejuni strains was investigated in 6 experiments. The formation of specific antibodies associated to colonization was also detected. In each experiment, day of hatch chicks were randomly separated into three groups of 24 birds each: two groups colonized experimentally and one control group. Chicks were reared on the floor in three separated, adjacent rooms with sterilized wood shavings as litter. At 2 or 8 days of age, respectively, the chicks in the experimentally colonized groups received between 3.3 x 10(7) and 2.0 x 10(8) colony-forming units (CFU) of C. jejuni via oesophageal gavage. Furthermore, 7, 14, 21, 28, 42 and 56 days after inoculation, 4 chicks of each group were sacrificed by cervical dislocation, at which time blood, liver and faeces were collected for processing. Serum was centrifuged and Campylobacter-specific IgG, IgA and IgM antibodies were measured by an indirect enzyme-linked immunosorbent assay (ELISA). Altogether, the colonizing capability of 11 C. jejuni strains was examined. Surprisingly, there were large differences between the C. jejuni isolates. After these experiments, we could divide the isolates into three groups. 4 out of 11 isolates could not be reisolated, 2 isolates caused weak or delayed colonization and 5 C. jejuni produced strong, long-lasting colonization. In the first days of life (9 days), the C. jejuni-free SPF chicks (control animals) had high IgG titres in sera, which decreased markedly up to the age of 15 days. During the experiments the IgM and IgA titres remained nearly at the same level, i.e., the amounts of maternal antibodies were low and there was no evidence for antibody formation in the chicks themselves. Two- and 8-day-old chicks were inoculated with C. jejuni strain Penner 1. Two-day-old chicks were colonized 3 weeks after inoculation. In comparison with these animals, 8-day-old chicks were colonized already 2 weeks after inoculation. There is the assumption, that the higher maternal antibodies in 2-day-old chicks could be responsible for this delay. In chicks the C. jejuni colonization resulted in a marked IgG (but not IgM and IgA) increase. Apparently, there is a positive relationship between the counts of this pathogen in caeca and the IgG increase. 相似文献
19.
IMC10200株ALV-J实验诱发禽骨髓性白血病的研究 总被引：2，自引：0，他引：2
对分离自肉种鸡群亚临床感染的J亚群禽白血病病毒IMC1o200株进行了实验感染诱发禽骨髓性白血病的病理学研究.IMC10200株J亚群禽白血病病毒尿囊腔接种11日龄肉鸡胚和SPF蛋鸡胚,孵出后跟踪观察.9周龄时随机抽检感染鸡,感染肉鸡特异引物PCR检测全部为阳性;组织病理学观察感染鸡无明显病变.至21周龄时感染肉鸡出现第一例典型骨髓性白血病病例;感染SPF蛋鸡未见明显J亚群禽白血病相关病变. 相似文献
20.
为评价鸡传染性贫血病毒AV1550株的致病性,取1日龄、7日龄和14日龄SPF鸡分别经胸部肌肉注射不同病毒含量的病毒液,同时设置正常对照,隔离饲养观察21日。感染后14日采血测定红细胞压积,21日统计死亡率、体重变化以及胸腺、骨髓、法氏囊病变情况并测定1日龄SPF鸡感染后不同组织中的病毒载量。结果表明,1日龄SPF鸡感染AV1550株后,表现出精神沉郁、增重减缓、贫血等明显的临床症状,死亡率为53.9%;死亡鸡或观察期结束时存活鸡剖检,可见胸腺萎缩,骨髓变成淡黄色;不同剂量感染后14日,均能引起红细胞压积显著下降;21日时,胸腺病毒载量最高,可达106.7copies/mg 。7日龄SPF鸡感染后,出现增重减缓,高感染剂量（100000EID50）出现贫血,部分鸡出现胸腺萎缩和骨髓病变,但病变率低于30%。14日龄SPF鸡感染后,不引起明显临床症状。研究证实,CAV对SPF鸡的致病性具有明显的日龄依赖性,红细胞压积降低、骨髓病变、胸腺萎缩以及胸腺病毒载量测定可作为评价CAV致病的指标。 相似文献