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1.
The pathogenicity of serotype 2 OH strain of infectious bursal disease virus (IBDV) to specific-pathogen-free (SPF) chicken embryos and 2-wk-old SPF chickens and turkey poults was investigated. The virus was pathogenic for chicken embryos after five passages as evidenced by pathologic changes in inoculated embryos. The embryo-adapted virus was not pathogenic for 2-wk-old SPF chickens and turkey poults as indicated by lack of clinical signs, gross or microscopic lesions in the bursa of Fabricius of inoculated birds. Bursa-to-body-weight ratios of the inoculated chickens and turkey poults were not significantly different from those of uninoculated controls. Virus-neutralizing antibodies to serotype 2 IBDV were detected in inoculated chickens and turkeys. Results of this study indicated that the embryo-adapted serotype 2 OH IBDV isolate that is pathogenic for chicken embryos is infectious but not pathogenic in chickens and turkeys. 相似文献
2.
Growth of serotypes I and II and variant strains of infectious bursal disease virus in Vero cells 总被引：4，自引：0，他引：4
The growth of five strains of infectious bursal disease virus--three strains of serotype I (SAL, D-78, 2512), one of serotype II (OH), and one variant strain (Variant-A)--were compared in Vero and chicken embryo fibroblast (CEF) cell cultures in order to characterize the replication of different strains of IBDV in Vero cells. For all five virus strains, the latent period in Vero cells ranged from 12 to 18 hr, which was longer than the 4-to-6-hr latent period observed in CEF cultures for strains SAL, D-78, and OH. Virus strains SAL, D-78, and OH, which were examined in both Vero and CEF cultures, also had a more extensive maturation phase and higher yields of virus in Vero than in CEF cultures. Total titers of these viruses of 5.35 to 6.10 log10 TCID50/ml in CEFs occurred 24 to 30 hr postinoculation (PI), although the cytopathic effect (CPE) was not seen until 72 hr PI. By comparison, their total infectious virus titers of 6.85 to 8.35 log10 TCID50/ml in Vero cells occurred from 48 hr PI, coinciding with the appearance of CPE. The growth curve of Variant-A in Vero cells differed from the other viruses by showing steadily rising extracellular and cell-associated virus titers throughout the 72-hr observation period. Only very low titers of Variant-A were obtained in CEF cultures, and thus no growth curve in CEFs was performed. 相似文献
3.
Two virus isolates were obtained from exotic finches (Ortygospiza atricollis and Poephila cincta) suffering from apathy, diarrhea, conjunctivitis, and dysphagia. The isolates were identified as paramyxoviruses based on their multiplication characteristics in embryonating chicken eggs, chicken embryo fibroblasts, and chicken embryo kidney cell cultures, on morphology upon electron microscopy, and on other biological properties. Both isolates were serologically related to the reference strain of the paramyxovirus serotype 3. Intravenous infection of 42-day-old chicks resulted in no clinical signs, but intracerebral infection of 1-day-old chicks resulted in mortality and intracerebral pathogenicity indices of 0.25 to 0.35. Of five finches from various species inoculated with isolate 840/85, three remained clinically healthy through 6 weeks, but two died: one (Poephila cincta) 5 days postinoculation after showing nervous distress, and the other (Amandava amandava) suddenly 42 days postinoculation. 相似文献
4.
Lim TH Lee HJ Lee DH Lee YN Park JK Youn HN Kim MS Youn HS Lee JB Park SY Choi IS Song CS 《Avian diseases》2011,55(4):554-560
Since 2007, 55 adenovirus strains have been isolated from commercial chicken flocks in Korea and have been identified and the pathogenicity of these isolates was confirmed in specific-pathogen-free chickens of different age. Based on sequencing analysis of the hexon gene, 55 FAdV isolates were genetically related to the IBH-2A strain of FAdV3 (4 isolates, 99.2% to 100%), the KR5 strain of FAdV4 (22 isolates, 97.9% to 99.2%), the 764 strain of FAdV9 (11 isolates, 99.1% to 99.3%), and the 1047 strain of FAdV11 (18 isolates, > 99%). Experimental infections with four serotypes of FAdV resulted in high mortality of 18-day-old chicken embryos and 1-day-old chicks with marked liver necrosis similar to those observed in the natural outbreaks. Notably, specific hydropericardium was observed in chicks challenged with the K531 strain (serotype 4). However, 3-wk-old chickens challenged with FAdVs, regardless of serotype, did not show any clinical signs or mortality except histologic lesions of focal hepatocytic necrosis with mild lymphocytic infiltration. The results indicate that four FAdV serotypes (3, 4, 9, and 11) are the dominant serotypes of FAdVs in the Korea and are pathogenic enough to cause clinical disease in young chicks. The present investigation provides important information on the epidemiology and pathogenesis of FAdVs and highlights the importance of control strategies against FAdV infection in Korea. 相似文献
5.
The G-4260, IR-N, M-6, and M-8 strains of avian nephritis virus (ANV) were inoculated orally into 1-day-old specific-pathogen-free chicks of the line PDL-1 for pathological and serological study. Five of 15 chicks inoculated with the G-4260 strain died with visceral urate depositions. One of 15 chicks each inoculated with the M-6 and M-8 strains died with nephrosis and visceral urate deposition, respectively. No chicks inoculated with the IR-N strain died. Mean body weights of ANV-inoculated chicks, except for the IR-N-inoculated chicks, at 14 days postinoculation (PI) were significantly lower than those of control chicks (P less than 0.01). However, interstitial nephritis was observed in all ANV-inoculated birds that were histopathologically examined at 14 days PI. In the serological study, the G-4260 and IR-N strains were classified as the same serotype, and the M-6 and M-8 strains were classified as a different serotype from the G-4260 and IR-N strains. These results indicate that there at least two serotypes of ANV and its strains differ in pathogenicity. 相似文献
6.
2株Ⅰ群禽腺病毒的分离鉴定及致病性分析 总被引：1，自引：1，他引：0
为了解山东省禽腺病毒（fowl adenovirus,FAdV）毒株的基因遗传演化情况及致病性,本试验对山东省两家疑似暴发鸡包涵体肝炎和心包积液综合征鸡场采集的病料（肝脏、脾脏）进行PCR鉴定,并将鉴定为FAdV的2份阳性病料提取病毒液,接种鸡肝癌细胞（LMH）进行毒株传代培养和细胞病变（CPE）观察、PCR检测、TCID50测定、鸡胚致病性试验、SPF鸡回归试验、病毒hexon部分基因扩增及序列分析。结果显示,试验成功分离到2株FAdV,2株分离株细胞传第1代即可观察到CPE,PCR均可扩增出大小为500 bp的片段,且2株分离株细胞F5代TCID50分别为10-7.75/0.1 mL和10-7.60/0.1 mL,均对7日龄SPF鸡胚有强致病性;第1分离株和第2分离株对21日龄SPF鸡攻毒死亡率分别为80%和15%。hexon基因核苷酸同源性分析结果显示,第1分离株与FAdV-4株同源性最高（99.57%）,第2分离株与FAdV-8b株同源性最高（99.18%）。这2株FAdV分离株均与Ⅰ群禽腺病毒同源,与火鸡出血性肠炎病毒（HEV）所在的血清Ⅱ群及减蛋综合征病毒（EDSV）所在的血清Ⅲ群禽腺病毒位于不同分支。第1分离株基因型为C型,血清型为4型,命名为FAdV-SDC4株;第2分离株基因型为E型,血清型为8b型,命名为FAdV-SDE8b株。综上所述,FAdV-SDC4和FAdV-SDE8b株属于近几年国内流行毒株。本研究结果可为鸡包涵体肝炎、心包积液综合征的防控工作和疫苗株的选择提供科学依据。 相似文献
7.
Hess M Prusas C Bergmann V Mazaheri A Raue R 《Berliner und Münchener tier?rztliche Wochenschrift》2000,113(5):202-208
Fowl adenoviruses of the serotype 4 from Germany were characterised by restriction enzyme analysis in comparison to isolates from Asia, South America and the FAV4 reference strain KR5. Only strain Da60 which was isolated from a psittacine aviary was identical with the reference strain KR5. None of the isolates was identical with the highly pathogenic strains from India and Ecuador. One-day-old chicks were infected orally and intramuscularly with the reference strain KR5, the psittacine isolate Da60 and isolate K1013 from Ecuador. Whereas no mortality was seen with the two strains KR5 and Da60, the mortality with K1013 was 100%. The main pathological signs were a swollen liver with necrosis and a lymphocyte depletion with a loss of the follicle structure. To investigate a second subject of avian adenovirus epizootiology several FAVs were characterized serologically and with PCR which was combined with the digestion of the PCR products. Including the reference strains, both methods were compared. It was shown that the digestion of the PCR products allows a clear attribution to a specific serotype, which underlines the usefulness of this method for diagnostic purposes. 相似文献
8.
Five continuous cell lines, swine testicular (ST), human rectal tumor (HRT 18), fetal rhesus monkey kidney (MA104), bovine turbinate (BT), and quail tracheal (QT35), were evaluated and compared with chicken embryo fibroblasts (CEFs) for their ability to propagate B1 or Texas GB strains of Newcastle disease virus (NDV). The NDV Texas GB strain replicated in all the continuous cell lines used in this study. Only the ST and QT35 cells produced a cytopathic effect (CPE) similar to that produced in CEFs. However, the ST cell line remained attached while displaying CPE, whereas infected QT35 cells detached, as did the CEFs. The B1 strain of NDV replicated in ST cells, MA104 cells, and CEFs but with less CPE as compared with the Texas GB strain. Pretreatment with trypsin did not enhance CPE with either NDV strain at the level tested. Sera evaluated for neutralizing antibody titers to NDV were significantly higher in titer when the ST cell line was used and compared with CEFs. A high correlation was found between the microscopic examination and the tetrazolium dye (MTT) microassay methods for determining the viral neutralization endpoint, thus suggesting the ST cell line and MTT microassay could be used as an alternative to CEFs and microscopic examination for evaluating neutralizing antibodies titers to NDV. 相似文献
9.
K Takehara T Shinomiya H Kobayashi Y Azuma T Yamagami M Yoshimura 《Avian diseases》1987,31(1):125-129
Seven Newcastle disease viruses isolated in Japan from 1930 to 1984 were cloned on chicken embryo fibroblasts (CEFs) and characterized biologically. All seven produced two or more types of plaques on CEFs. The plaques were classified into four types. Plaque cloning was carried out five times, and 22 cloned viruses were established. The biological characters of the cloned viruses suggested that the strains contain different clones and that their clones are different even among close cases, such as G strain and H strain. 相似文献
10.
用SPF鸡胚从病死鸽的内脏组织中分离到一株新城疫病毒(命名为GD-09株),该病毒能使鸡红细胞发生凝集,且这种凝集能被鸡新城疫标准阳性血清所抑制。经测定,其鸡胚平均死亡时间（MDT）、1日龄雏鸡脑内接种的致病指数（ICPI）分别为57.6 h、1.74,表明该新城疫病毒为强毒。通过分析其融合蛋白（F）发现,F蛋白多肽裂解位点为112RRQRRF117,符合NDV强毒株裂解位点氨基酸序列。F基因分型及氨基酸同源性比较发现,GD-09株属于基因Ⅵ型,与La sota、F48E9、B1、V4等传统毒株同源性较低,与鸽源NDV同源性较高。 相似文献
11.
A comparison was made between pathogenicities for chicken embryos of unattenuated and attenuated strains or isolates of infectious laryngotracheitis (ILT) virus. All 11-day-old chicken embryos inoculated with 10(3.0) or 10(4.0) TCID50 of unattenuated strain NS175 via allantoic cavity died within 6 days. On the contrary, no chicken embryos of the same age died when inoculated with the same amount of cell-culture-attenuated isolate C7 in a like manner. The mortality index for chicken embryos (MICE) was obtained by dividing the cumulative number of embryos dying within 7 days by the cumulative number of embryos surviving 7 days. The reliability of the MICE test was confirmed by duplicate and triplicate experiments with strain NS175 and isolate C7. MICE obtained in the experiments with 9 different strains or isolates of ILT virus ranged from 0 to 1, and the values were well correlated with the pathogenicities for chickens. The results from the present work suggest that strains or isolates with MICE less than 0.16 would have low or no pathogenicity for chickens, and those with MICE more than 0.27 would be highly pathogenic. Further studies are needed using additional isolates of ILT virus with varied pathogenicities. 相似文献
12.
鸭源新城疫病毒的分离鉴定 总被引：1，自引：0，他引：1
从病死肉鸭肝脏中分离到2株病毒(ZH1、ZH2),均能够凝集鸡、肉鸭、绵羊、山羊、猪、人、兔、牛等的红细胞,且这种血凝性可被NDV标准阳性血清所抑制.参照NDV毒力判定标准及其方法对分离毒株ZH1、ZH2进行了鸡胚最小致死量平均死亡时间(MDT)、鸡胚半数感染量(EID50)以及1日龄鸡脑内接种致病指数(ICPI)测定,结果ZH1、ZH2株的MDT为52 h和44 h,EID50为106.4/0.1mL和108.64/0.1mL,ICPI为1.93和1.975.表明这2株分离病毒均为NDV强毒株. 相似文献
13.
A commercial infectious bronchitis virus (IBV) vaccine of the Massachusetts 41 strain was injected in embryonating chicken eggs on embryonation day (ED) 18. The IBV vaccine was pathogenic for embryos, and it was passaged in chicken kidney tissue culture to reduce the pathogenicity. At the 40th tissue culture passage (P40-IBV), the virus became apathogenic for the embryos. Maternal antibody-positive or -negative chicks hatching from eggs injected with P40-IBV developed antibody to IBV and were protected against challenge exposure at 4 weeks of age with virulent Massachusetts 41 IBV. Although P40-IBV protected chicks when administered on ED 18, this virus did not protect chicks well if given at hatch. When combined with the turkey herpesvirus (HVT), P40-IBV given on ED 18 did not interfere with the protection against challenge exposure with virulent Marek's disease virus, nor did the presence of HVT interfere with protection by P40-IBV. Thus, under laboratory conditions, IBV vaccine could be combined with HVT to form a bivalent embryonal vaccine. 相似文献
14.
15.
Eleven avian adenoviruses were isolated in monolayer cultures of specific pathogen free chicken kidney cells which were inoculated with suspensions of liver, intestine or bursa obtained from 15 broiler flocks experiencing outbreaks of inclusion body hepatitis (10 isolates) and from five unaffected flocks (one isolate). Of the 11 isolates obtained, nine were identified by virus neutralisation tests as serotype 8, one as serotype 1 and one as serotype 12. Adeno-associated viruses were only observed in combination with adenoviral particles of the serotype 12 isolate which was derived from a relatively mild outbreak of inclusion body hepatitis. Only the serotype 1 isolate, obtained from the unaffected broiler flock, consistently caused the death of embryos with marked pathological changes. All of the isolates produced basophilic intranuclear inclusion bodies surrounded by clear halos in chicken kidney cell cultures. DNA preparations, obtained from six strains of serotype 8 avian adenovirus (two New Zealand isolates, three Australian isolates and the reference strain HVI) after digestion with the restriction enzymes EcoRI and BamHI, gave electrophoretic patterns showing the New Zealand isolates to be similar to one another and to strain HVI, but quite distinct from the Australian isolates. 相似文献
16.
Four pathogenic avian adenovirus isolates associated with inclusion body hepatitis and mortality in commercial broiler chicks and chickens were characterized and identified. These group I avian adenovirus isolates were classified as group E (serotypes 6, 7, 8, and 9) avian adenoviruses on the basis of the restriction enzyme patterns of their viral DNA. Isolate 3718 was neutralized by a serotype 6 reference avian adenovirus antiserum and isolates 8193, 8380, and 8565 were all neutralized by a serotype 8 reference avian adenovirus antiserum by virus neutralization assays. Infectivity and virulence such as mortality, hemorrhages, enlarged green livers with intranuclear inclusion bodies, stunting, intestinal sloughing, and poor feathering were observed in specific-pathogen-free chicken embryos and were identical for all four isolates when embryos were inoculated via the yolk sac and/or chorioallantoic membrane. Complete mortality was observed within 72 hr postinoculation in specific-pathogen-free (SPF) chickens inoculated intramuscularly for all four avian adenovirus isolates. 相似文献
17.
An isolate Enterococcus hirae was used to determine its pathogenicity for chicken embryos and for chicks treated with betamethasone. E hirae was inoculated intravenously into four-day-old chicks which had been treated for three consecutive days with betamethasone, and chick embryos were inoculated into the allantoic cavity with 102 and 103 bacteria. E hirae was not pathogenic for the chicks or for the embryos. 相似文献
18.
K Takase N Yoshinaga T Egashira T Uchimura M Yamamoto 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(2):207-215
Avian adenoviruses were isolated from two pigeons affected with inclusion body hepatitis (IBH) by using chicken embryo liver cell cultures. One of the isolates, designated strain S-PL1, replicated in the cell nuclei forming intranuclear inclusion bodies, showed adenovirus-like morphology by electron microscopy, and cross-reacted serologically with strain SR-48 known as serotype 2 of fowl adenovirus. The strain S-PL1 killed day-old chicks by subcutaneous inoculation, and its 50% chicken lethal dose was 10(3.8) plaque forming units per bird. Severe lesions characterized with IBH and pancreatitis, were produced in chicks inoculated with the virus. Intranuclear inclusion bodies were also recognized in the liver, pancreas, kidney, proventriculus, small intestine, and caecum. By indirect immunofluorescence test, intranuclear viral antigens were detected in the liver, pancreas and other tissues. 相似文献
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20.
鸡新城疫山东强毒株的分离鉴定及致病性研究 总被引：5，自引：0，他引：5
从山东省不同地区的发病鸡群中分离了6株病毒，经HA、HI试验、病毒回归试验和血清中和接种鸡胚试验确定所分离的毒株为新城疫病毒。分别对6个毒株MDT、ICPI和IVPI进行了测定，结果表明这些毒株为鸡新城疫强毒，但各个毒株的致病性有所差异。 相似文献