共查询到19条相似文献，搜索用时 140 毫秒
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鸡传染性支所管炎病毒（IBV）具有高度的变异性，血清型众多，且有继续增加的趋势。文章从IBV的基因组、结构蛋白及复制进行分析，阐述了病毒分子的变异及机制，并为鸡传染性支气管炎（IB）的免疫预防奠定了基础。 相似文献
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鸡传染性支气管炎的免疫机制 总被引：2，自引：0，他引：2
由鸡传染性支气管炎病毒(Infectiousbronchitisvirus, IBV) 引起的鸡传染性支气管炎由于病毒血清型较多, 易于发生变异而难以免疫预防,成为养鸡业发展的重大阻力。本文从IBV的分子免疫学结构, 在鸡体内引起的体液免疫和细胞免疫方面进行IB免疫机制分析, 提出了具有借鉴价值的免疫方法。 相似文献
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为阐释鸡传染性支气管炎病毒（avian infectious bronchitis virus，IBV）的高变异特性及其原因，从IBV的不同病变型、分子变异及免疫机理几方面概述了IBV的研究进展，提出了IBV基因组突变、免疫压力和不同毒株基因组间的同源重组所导致的病毒血清型、基因型和组织嗜性的改变是造成免疫失败的主要原因。 相似文献
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鸡传染性支气管炎病毒免疫机制和免疫预防研究进展 总被引：1，自引：0，他引：1
由鸡传染性支气管炎病毒（Infectious bronchitis virus,IBV）引起的鸡传染性支气管炎（Infectious bronchitis,IB）是高度传染的全球性鸡病之一,严重危害养鸡业。IBV众多的血清型及其基因组的不断变异,给IB的免疫防控带来很大的困难。IBV主要侵害鸡的呼吸系统、泌尿生殖系统和消化系统,病鸡出现呼吸困难、产蛋下降、肾炎和腺胃炎等症状和病变。IBV的特点是变异频繁,血清型复杂,所致疾病的临床表现差异很大。因此,IB已成为养禽业最难控制的疫病之一。鸡对IBV的免疫机制是国内外研究的热点之一。传统疫苗已不能完全保护免疫鸡群,开发IBV基因工程疫苗,从主要免疫原性蛋白的良好表达到免疫策略的不断完善,已成为未来预防IB的趋势。 相似文献
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鸡传染性支气管炎(IB)是由鸡传染性支气管炎病毒(IBV)引起的鸡急性、高度接触性传染病。该病以气管损伤、母鸡产蛋量下降和产畸形蛋为特征。尤其是近年来由于IBV新的血清型不断增加和变异株的不断出现,给养鸡业造成了严重的经济损失。IBV的主要结构蛋白为纤突蛋白(S)、膜蛋白(M)和核蛋白(N),其中核蛋白是病毒内部的核衣壳蛋白,由IBV基因mRNA A编码,在进化中最为保守,可产生交叉中和抗体。同时核蛋白具有刺激机体产生细胞免疫的功能,在抗IBV感染中起重要作用。因此,针对核蛋白的研究在IBV流行病学研究中具有重要代表意义,文章对I… 相似文献
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鸡传染性支气管炎病毒分子生物学研究进展 总被引：4，自引：0，他引：4
鸡传染性支气管炎 ( IB)是由鸡传染性支气管炎病毒 ( IBV)感染引起的鸡的一种急性高度接触性呼吸道和生殖管道的疾病 ,有的毒株还可以引起肾脏、肠道和腺胃的病变。近几年 ,国内由于新的变异株不断出现 ,导致现有疫苗的免疫效果不够理想 ,在临床上时有 IB的发生和流行 ,引起兽医科技工作者的广泛关注。与先进的生物技术相结合 ,我国 IBV分子生物学的研究取得较大进展 ,有些方面已经达到国际领先水平 ,本文主要就近几年来国内的研究成果作一综述。1 病毒的结构蛋白IBV的主要结构蛋白有 3种——纤突蛋白 ( S蛋白 )、膜蛋白 ( M蛋白 )和… 相似文献
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J. H. H. van Eck 《The Veterinary quarterly》2013,33(1):11-25
Following BCI4 (EDS'76) virus infection of brown layer hens at 33 weeks of age, production of normally shelled eggs dropped from 87 per cent to 49 per cent within 3 weeks. The production of soft shelled and shell‐less eggs attained a maximum of 33 per cent 3 weeks after infection (p.i.). Shell quality recovered completely within 5 weeks p.i. Egg production problems in White Leghorns infected with BCI4 virus were less severe and of shorter duration than in brown layers. Both in brown layers and in White Leghorns total egg production, mean weight of normally shelled eggs, and internal egg quality were not affected following BCI 4 virus infection at 33 and 28 weeks of age, respectively. Besides shell abnormalities no clinical disease symptoms were observed. Vaccination with a commercial EDS'76 vaccine (Nobivac EDS'76®) at 17 weeks of age had no adverse effects on laying performance and provoked adequate immunity against challenge at 33 weeks of age. The same observations were made following BCI4 virus infection at 17 weeks of age. After infectious bronchitis virus (IBV) (H52 virus) infection of laying fowl the percentage of eggs with shell aberrations (rough, misshapen and/ or soft shells) increased to a maximum of 8 per cent, total egg production was depressed, mean egg weight was reduced I to 2 grams, and up to 10 Per cent of normally shelled eggs showed watery, not ropy thin albumen. This abnormally thin albumen was observed in a considerably higher proportion of eggs with shell defects than in normally shelled eggs. No turbidity of the thick albumen was observed and no symptoms of respiratory disease were noticed. The severity and duration of adverse effects of IBV infection on laying performance depend very much on the stage of production in which the infection occurs. Following IBV infection at the onset of production a much severer drop in total production and in production of normally shelled eggs, a greater increase in the number of abnormally shelled eggs, and more lasting adverse effects on egg weight and internal egg quality were observed, in comparison with infection after peak production. Compared with single infections, a combined BC14 virus and IBV infection of brown layers at 33 weeks of age resulted in greatly potentiated adverse effects on total egg production, number of eggs with aberrant internal quality, and duration of production problems. Following a combined BC14 virus and IBV infection, in a great proportion of eggs with shell defects and watery thin albumen, turbidity of the thick albumen was observed also, probably due to combined effects on the uterus of both IBV and BC14 virus. BC14 virus infection did not reinforce the adverse influence of IBV infection on egg weight. The same observations as described for the combined BC14 virus and IBV infection were made following BC14 virus infection of fowl previously infected with IBV. It is concluded that changes of internal egg quality in field cases of EDS'76 are most likely due to subclinical IBV infections. After infection of brown layers at 33 weeks of age with fowl adenovirus 66 (FA V 66) neither symptoms of clinical disease were observed nor effects on egg production, egg weight, and egg quality. Also, in a combined infection with FA V66, IBV, and BCI4 virus, no pathogenic significance could be attributed to the FAV. 相似文献
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Infectious bronchitis (IB) is a worldwide disease affecting chickens of all ages and causing important economic losses in poultry industry. Despite being one of the predominant IB virus (IBV) serotype in several European countries, slightly is known about pathogenesis and pathogenicity of Italy 02 serotype. In this study chicks and old hens were infected by oculo-nasal route with Italy 02 serotype. Clinical signs, gross and microscopic findings were evaluated, viral nucleic acid detection was assessed by in situ hybridization (ISH) in several tissues and viral RNA was detected by RT-PCR in trachea, kidney and nasal and cloacal swabs. Italy 02 serotype was demonstrated to cause severe respiratory and renal damage in one-day old chicks but not in adult hens in which only respiratory disease and drop in egg production was observed. The use of ISH technique demonstrated the presence of viral RNA in nasal turbinates prior to trachea, but more consistent and longer replication periods in enterocytes of lower gastrointestinal tract. The detection of viral nucleic acid in gut by RT-PCR was consistent and more persistent viral shedding was detected in faeces than in nasal exudates. We describe a complete update of IBV distribution in tissues by the use of molecular techniques and we also provide and in-depth pathological characterization of the new Italy 02 IBV serotype. Furthermore, new data about IBV pathogenesis essential in field control is afforded. 相似文献
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Escherichia coli numbers and histopathological changes were studied in the respiratory tract of line 151 chickens intranasally inoculated with infectious bronchitis virus (IBV) and/or virulent E. coli; this line is highly susceptible to IBV. Chickens inoculated with IBV alone showed increased numbers of E. coli in the trachea and had tracheitis, airsacculitis, and bronchiolitis. One of 17 chickens inoculated with IBV alone died with fibrinopurulent serositis. Chickens inoculated with IBV and E. coli had more severe and persistent respiratory lesions than those inoculated with IBV alone. E. coli was isolated from tracheas of chickens inoculated with IBV and E. coli more frequently than from chickens inoculated with IBV alone. In this group, 14 of 27 chickens died with tracheal plugs or with fibrinopurulent serositis. There was neither increased numbers of E. coli nor significant lesions in the respiratory tract of the group inoculated with E. coli alone. These results suggest that IBV may facilitate E. coli invasion into the lower respiratory tract of the chicken. 相似文献
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鸡传染性支气管炎是一种急性高度接触性呼吸道传染病,影响鸡的产蛋量和蛋品质。本研究以鸡传染性支气管炎病毒标准株M41人工感染21日龄700只海兰褐雏鸡,使其发病。接种病毒前后在饮水中分别添加不同剂量的清瘟败毒颗粒,以清瘟败毒散为对照治疗组,观察不同处理鸡的临床症状、发病率、病理变化和死亡率等。结果表明：饮水中添加0．z5％o清瘟败毒颗粒,对IBV标准株M41的攻毒保护作用与阳性对照组相比较差异显著（P〈0．05）;清瘟败毒颗粒低剂量治疗组与高、中剂量治疗组及清瘟败毒散治疗组之间差异显著,因水中添加0．5‰清瘟败毒颗粒,对人工感染鸡传染性支气管炎治疗作用明显,治愈率达88．00％,显著高于清瘟败毒散治疗组（P〈0．05）。 相似文献
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Tissue tropism of three cloacal isolates and Massachusetts strain of infectious bronchitis virus 总被引：1，自引：0，他引：1
Three virus isolates (ECV-1, -2, and -3) recovered from cloacae of chickens in flocks that experienced drops in egg production were identified as infectious bronchitis virus (IBV), based on characteristic embryo lesions, chloroform sensitivity, coronavirus morphology, and serology. Because these isolates were recovered from the cloacae of the hens, their tissue tropism was compared with the prototype strain of IBV, Massachusetts-41 (M-41), in experimentally inoculated chickens. During the 39-day period postinoculation (PI), virus isolation was attempted from digestive and respiratory tracts, kidney, and cloacal swabs. ECV-1, ECV-2, and M-41 were more frequently recovered from the cecal tonsils than from other tissues. ECV-1, ECV-3, and M-41 were also recovered from kidney for up to 39 days PI. ECV-2 and ECV-3 had a limited distribution in respiratory tissues, being isolated only sporadically from trachea, bronchus, and lung. Surprisingly, ECV-2 was isolated from esophagus at 2, 16, 30, and 39 days PI; otherwise, its distribution in other tissues was sporadic. Results confirmed that IBV, including M-41, can infect a variety of tissues and that some isolates may be recovered frequently from digestive tract tissues, particularly from the cecal tonsils. 相似文献
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Gharaibeh SM 《Preventive veterinary medicine》2007,78(3-4):317-324
Infectious bronchitis virus (IBV) causes respiratory disease in chickens all over the world. IBV has many serotypes that do not confer cross protection against each other. Hemagglutination inhibition (HI) test has been used to determine the serotypes of IBV as a substitute to the more laborious virus neutralization test and the more sophisticated restriction endonuclease digestion or sequencing of the S1 gene. In Jordan, no previous studies have been carried out to determine the involvement of IBV in respiratory disease in chickens, or the serotypes of IBV that possibly exist. In this study, serum from different chicken flocks (n = 20) that suffered from respiratory disease were tested for IBV antibodies using commercial IBV antibody ELISA at time of the initial signs of the respiratory disease and repeated on serum samples from the same flocks 10–14 days later. ELISA titer for IBV increased in 14 out of 20 flocks (70%) after 10–14 days of the initial signs of the respiratory disease and this indicates a recent exposure to IBV. The second serum samples from these 14 flocks were further examined against a panel of five IBV antigens (Ark, Conn, DE-072, JMK, and Mass) by HI test to determine the serotype(s) of IBV they have been exposed to. The HI test results indicated that the exposure of some of these flocks were to Ark, DE-072, and Mass like serotypes. However, the HI titers against the antigens used in this study were relatively similar in 10 out of the 14 flocks (71%) and the serotype of IBV that these flocks were exposed to could not be determined and the possible causes of this are discussed. 相似文献
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K G Gillette 《Avian diseases》1981,25(2):431-443
Specific-pathogen-free chickens were tested for local antibody response after respiratory exposure to live avian infectious bronchitis virus (IBV). Tracheobronchial secretions were obtained after intraocular-intratracheal vaccinations with Holland and Massachusetts 41 strains IBV. Low levels of immunoglobulin (Ig)A and IgG virus-neutralizing antibodies were detected in secretions after each of two vaccinations with a moderate dose (10(4) EID50), neutralizing activity in secretions was found mainly in IgG antibody. Only challenge exposure to Holland IBV resulted in a marked secondary secretion antibody response. 相似文献