鸡腺胃型传染性支气管炎油乳剂灭活疫苗的研制与应用

鸡腺胃型传染性支气管炎（腺胃型ＩＢ）是近年来严重影响我国养鸡业的一种新的传染病。于１９９７年６月始在我省的淮南、合肥、巢湖等地的鸡群中发现此病。主要表现为病鸡羞明、流泪、肿眼,有呼吸道症状,且有拉稀、消瘦等症状;剖检特征病变为腺胃肿大如球状,胃壁增厚,腺胃乳头有出血等,很易误诊为鸡马立克氏病和鸡新城疫病,死亡率３０％左右。该病在临床症状和剖检变化上与呼吸型及肾型传支有着明显的不同,使用现有的呼吸型及肾型传支疫苗对本病没有保护作用,所以研制出能有效预防鸡腺胃型传支病的疫苗是当务之急。鉴于此,我们利…     

鸡腺胃型传染性支气管炎的发生和病毒分离

我们在北京分离到１株鸡腺胃型传染性支气管炎病毒，表明有本病在北京地区流行，应引起注意。１发病情况１９９７年１０月以来，北京地区某鸡场的５０～８０日龄的海兰白育成鸡发生一种以流泪、伴有呼吸道症状、渐进性消瘦、腹泻、陆续死亡为特征的流行性疾病。两个鸡场的...     

商丘市鸡腺胃性传染性支气管炎发病初报

鸡传染性支气管炎 (IB)是由传染性支气管炎病毒引起的一种急性、高度接触性呼吸道传染病。各种日龄、各种品种鸡均可发生。 　　传染性支气管炎病毒 (IBV)属冠状病毒科、冠状病毒属。 IBV的血清型很多，迄今为止已分离出 20多个血清型和更多的变异株，随着疫苗的使用，新的血清型不断出现， IBV对鸡的致病性也发生变化。根据临床症状和病理变化，将 IB分为 5个类型： (1)呼吸型； (2)肾型； (3)肠型； (4)生殖道型或产蛋异常型； (5)腺胃型。 　　1997年王玉东报道引起腺胃型病变的 IBV变异株。 1995年以来，在江苏、山东、山西、广…     

传染性支气管炎和传染性喉气管炎的鉴别与防治

传染性支气管炎和传染性喉气管炎．都是由病毒引起的鸡的急性高度接触性呼吸道传染病。临床上都以呼吸困难为主要特征，幼龄鸡和成年鸡都可感染发病，两者相似点很多。但传染性支气管炎的病原体是冠状病毒属的传染性支气管炎病毒，现已知有25个血清型，其中主要的是呼吸道型（以M株、C株为代表）、肾型（以T株为代表）、腺胃型，新的血清型仍在不断出现，     

鸡传染性支气管炎的诊断与控制

鸡传染性支气管炎(IB)是仅发生于鸡的急性、高度接触性的呼吸道疾病。本病呈世界性分布。据报道，本病在临诊上常有腺胃型传染性支气管炎(腺胃型IB)、呼吸型传染性支气管炎(呼吸型IB)、肾型传染性支气管炎(肾型IB)等。     

一例呼吸型鸡传染性支气管炎的中西医治疗

本病由传染性支气管炎病毒及变异株引起的鸡急性、高度接触呼吸道传染病。各种日龄的鸡均易感,42日龄以下的雏鸡易感,49日龄以后的鸡感染后很少表现明显症状。病鸡主要表现为咳嗽、打喷嚏和发生气管锣音。雏鸡流鼻液,成年鸡除有呼吸道症状外,还表现产蛋减少,产薄壳蛋、砂壳蛋、褪色蛋,畸形蛋增多,蛋清稀薄与蛋黄分离。由于病毒侵害器官的差异,临床上常分为呼吸型、肾型、腺胃型和生殖型传染性支气管炎。本文主要介绍一例呼吸型鸡传染性支气管炎的诊治。     

鸡传染性支气管炎的诊断与控制

鸡传染性支气管炎（Infections Brnchitis of Chickens,IB）是仅发生于鸡的急性，高度接触性的呼吸道疾病。本病呈世界性分布。据报道，本病在临诊上常有腺胃型传染性支气管炎（腺胃型IB），呼吸型传染性支气管炎（呼吸型IB），肾型传染性支气管炎（肾型IB）。     

我省发生鸡腺胃型传染性支气管炎

今年以来，我省豫北、豫南一些养鸡场发生一种以不同品种的育成鸡以临床极度消瘦、有呼吸道症状，剖检腺胃肿大如球状为主要特征的接触性传染病。7月份以来，平顶山叶县某养鸡场饲养的伊利莎种鸡、罗曼蛋鸡共计万余只，分别于7O日龄和35日龄开始发病。发病率高，病程已近4O余天。主要临床表现为食欲减退，精神沉郁，生长缓慢，拉稀伴有呼吸道症状，后期极度消瘦，衰竭死亡，死亡率达15～20％。剖检主要症状：病鸡消瘦、气管有粘液，中后期出现本病特征性病变，腺胃显著肿大如球状，腺胃壁增厚，腺胃粘膜有出血和溃疡，腺胃乳头肿胀、出血，…     

肉鸡腺胃型传染性支气管炎病的诊断

1997年8月，郑州市某肉鸡场2000只18日龄肉鸡发生一种拉稀、消瘦，伴有呼吸道症状及死亡，剖检腺胃肿大如球状为特征的疾病。经发病情况、临诊症状、剖检病变和实验室诊断，初步诊断其病原为鸡传染性支气管炎病毒，因此将本病暂定名为鸡腺胃型传染性支气管炎。现将诊断结果报告如下：一、发病情况这批肉维分别在1日龄、10日龄和14日龄进行了鸡马立克病、鸡新城疫、鸡传染性支气管炎和鸡传染性法氏囊病的免疫接种，18日龄个别雏鸡开始发病死亡，以后逐日增多，20～25日龄形成死亡高峰，经强力霉素、新霉素加维生素C治疗后，死亡减少，至56日…     

青岛发生鸡腺胃型传支

青岛发生鸡腺胃型传支王玉东（农业部动物检疫所）１９９６年９月份以来，青岛地区许多养鸡场尤其在河套、上马、红岛等乡镇养鸡场的２５—９０日龄育成鸡连续发生了一种以流泪、肿眼、伴有呼吸道症状，拉稀，极度消瘦，死亡，剖检表现腺胃肿大如球状，腺胃壁增厚，腺胃粘...     

Pathogenicity and antigenicity of a new variant of Korean nephropathogenic infectious bronchitis virus

Despite the existence of an active vaccination program, recently emerged strains of nephropathogenic infectious bronchitis virus (IBV) in Korea have caused significant economic losses in the poultry industry. In this study, we assessed the pathogenic and antigenic characteristics of a K-IIb type field strain of IBV that emerged in Korea since 2003, such as Kr/Q43/06. Specific pathogen free 1-week-old chickens exhibited severe respiratory symptoms (dyspnea) and nephropathogenic lesions (swollen kidneys with nephritis and urate deposits) following challenge with the recent IBV field strain. The antigenic relatedness (R value), based on a calculated virus neutralization index, of the K-IIb type field strain and K-IIa type strain KM91 (isolated in 1991) was 30%, which indicated that the recent strain, Kr/Q43/06, is a new variant that is antigenically distinct from strain KM91. This report is the first to document the emergence of a new antigenic variant of nephropathogenic IBV in chicken from Korea.     

Molecular characterization of avian infectious bronchitis virus strains isolated in Colombia during 2003

Sixteen infectious bronchitis virus (IBV) isolates were recovered from broilers and layers from five geographic poultry regions in Colombia. The viruses were isolated from tracheas, lungs, and cecal tonsils of birds, previously vaccinated with the Massachusetts strain, that were showing respiratory signs. Further analysis of the IBV isolates was achieved by phylogenetic analysis comparing their deduced amino acid sequences in the hypervariable region 1 of the S1 gene with reference strains. Four unique genotype clusters containing isolates with indigenous genotypes were observed. One isolate was found to be the Connecticut genotype and three isolates were found to be the Massachusetts genotype.     

Dynamics of avian coronavirus circulation in commercial and non-commercial birds in Asia – a review

It is essential to understand the latest situation regarding avian coronaviruses (ACoVs), commonly referred to as the well-known avian infectious bronchitis virus (IBV), given that new and diverse types of IBV are continually being identified worldwide, particularly ones that are isolated from commercial poultry and associated with a wide range of disease conditions. The existing IBVs continue to evolve in various geographic areas in Asia, which results in the recombination and co-circulation between IBV types. This makes it increasingly difficult to prevent and control IBV infections, despite routine vaccination. Some ACoVs have also been identified in other avian species and they may pose a threat of cross-transmission to commercial sectors. The present review provides an overview of IBV circulation and the dynamic emergence of new variants found throughout Asia via the recombination of IBV strains. In addition to commercial poultry, backyard poultry and free-ranging birds may serve as a ‘hub’ for ACoV transmission within a particular area. These birds may be capable of spreading viruses, either to areas of close proximity, or to remote places via migration and trade.     

鸡传染性支气管炎病毒致病机理的研究进展

鸡传染性支气管是由鸡传染性支气管炎病毒引起鸡的一种急性高度接触性呼吸道传染病,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。文章就该病毒的致病机理方面的研究情况做一综述,为防制鸡传染性支气管炎提供科学依据。     

鸡传染性支气管炎病毒免疫机制和免疫预防研究进展

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。     

The isolation and some biological properties of a variant avian infectious bronchitis virus.

A virus isolated from a respiratory disease in chickens was identified as infectious bronchitis virus (IBV). By serum neutralisation tests the virus was shown to be serologically distinct from the Massachusetts type but to possess a one-way relationship with the Connecticut type. Experimentally, it caused a relatively mild respiratory disease in baby chicks. Vaccination of young chicks with H-120 Massachusetts IBV vaccine afforded a high degree of protection against challenge with the isolate. Some problems relating to the isolation and classification of field strains of IBV are briefly discussed.     

Evaluation of the protection conferred by commercial vaccines and attenuated heterologous isolates in China against the CK/CH/LDL/97I strain of infectious bronchitis coronavirus

Avian infectious bronchitis virus (IBV) causes tremendous economic losses to the poultry industry worldwide. Different serotypes of this virus show little cross-protection. The present study investigated the genotypic relationship between CK/CH/LDL/97I-type strains and reference IBVs based on S1 gene comparisons and the protection provided by vaccination with commercial vaccines and attenuated homologous and heterologous strains. Phylogenetic analysis and the comparison of S1 showed that CK/CH/LDL/97I-type virus might be a new serotype compared to vaccine strains and other types of IBV isolates in China. Protection efficacy was evaluated by morbidity, mortality, and virus re-isolation from the challenged chicks. Complete protection by IBV vaccination was provided by the homologous strain but sufficient respiratory protection was not provided by the commercial vaccines. Heterologous strains against CK/CH/LDL/97I challenge and the development of a vaccine against CK/CH/LDL/97I-type IBV will be necessary to control infectious bronchitis disease in poultry. Further development of the attenuated CK/CH/LDL/97I strain may provide a valuable contribution towards this goal.     

Viral pathogenesis of a nephrotropic infectious bronchitis virus isolated from commercial pullets.

Infectious bronchitis was diagnosed in 3-to-4-week-old pullets from an outbreak in a commercial flock in California. The disease was characterized by head swelling, watery discharge from the eyes and nostrils, and urates in kidneys. Mortality ranged from 1.8% to 12.5% per week. The isolation of a coronavirus from a suspension of pooled kidneys from clinically ill chickens at the fifth passage in 10-day-old chicken embryos, gross and histologic renal lesions, and seroconversion by enzyme-linked immunosorbent assay in inoculated birds suggested that the virus isolated was a nephrotrophic strain of infectious bronchitis virus (IBV). The virus isolate was found to be a previously unrecognized serotype, based on virus neutralization tests performed in embryonated chicken eggs. Nephropathogenicity of the IBV isolate was confirmed by inoculation of the viral isolate into specific-pathogen-free chicks and demonstration of renal lesions. The isolation of nephrotropic strains of IBV has not been reported previously from poultry in California.     

Molecular characterization of infectious bronchitis virus strains isolated from the enteric contents of Brazilian laying hens and broilers

Infectious bronchitis virus (IBV) is the causative agent of avian infectious bronchitis, which is characterized by respiratory, reproductive, and renal signs. However, the role of IBV as an enteric pathogen in still controversial. In Brazil, antigenic groups of IBV divergent from the Massachusetts serotype used for vaccination schedules in that country have already been demonstrated. The present study aimed to assess the different genotypes of IBV in Brazilian commercial poultry flocks by partial sequencing of the S1 amino-terminus coding region using enteric contents as samples and examine their relationship with the vaccine serotype currently in use. Samples of enteric contents were taken as pools of five birds from each of 18 poultry farms (17 broiler and one laying farm) from five Brazilian states between 2002 and 2006. Birds were presenting watery diarrhea and poor general condition but were without respiratory, renal, or reproductive signs. Conventional antibacterial and anticoccidial therapies were unsuccessful and, furthermore, all samples proved negative for rotavirus, reovirus, and astrovirus. Eleven IBV samples were isolated in embryonated eggs and resulted in S1 sequences. Phylogenetic analysis showed that these segregated into an exclusive cluster, close to serotype D274, but distant from Massachusetts. Mean amino acid identity amongst these Brazilian strains was 94.07%; amongst these and serotypes D274, 4/91, and Massachusetts, mean amino acid identity was 77.17%, 69.94%, and 68.93%, respectively. In conclusion, the presence of genotype variant strains of IBV in Brazilian poultry flocks has been demonstrated and might be the reason for the unsuccessful control of IBV in Brazil. Furthermore, these results also strengthen the implications of IBV in enteric diseases of poultry.