对鸡传染性喉气管炎的防治

鸡传染性喉气管炎(ILT)是由鸡传染性喉气管炎病毒(ILTV)引起的一种急性呼吸道传染病.该病的特征为呼吸困难、气喘、咳嗽并咳出血样分泌物,病变多在气管上1/3处,剖检病变为喉头、气管黏膜肿胀、出血并形成糜烂.     

鸡传染性喉气管炎的发生与防治

鸡传染性喉气管炎（ILT）是由鸡传染性喉气管炎病毒引起的鸡的一种急性、接触性呼吸道传染病。主要特征为结膜炎、呼吸困难、咳出带血的渗出物，喉头及气管部黏膜肿胀、出血、甚至糜烂、坏死。     

开产蛋鸡传染性喉气管炎的PCR诊断及防治

鸡传染性喉气管炎(infectious laryngotrache-itis,ILT)是由鸡传染性喉气管炎病毒(ILTV)引起的鸡的一种急性接触性呼吸道传染病。病鸡主要表现呼吸困难、咳嗽、喘气、甩头,严重者咳出血样粘液。病理剖检可见喉头及气管黏膜肿胀、弥漫性出血,表面附着带血的渗出物或黄色干酪样假     

蛋鸡传染性喉气管炎病毒的分离、PCR检测及TK基因序列分析

<正>鸡传染性喉气管炎(ILT)是由传染性喉气管炎病毒(ILTV)感染引起的一种急性、接触性的上呼吸道传染病,病原属于疱疹病毒科的ɑ疱疹病毒亚科,在分类学上被确定为禽疱疹病毒Ⅰ型[1]。鸡传染性喉气管炎的临床症状主要为呼吸困难、咳嗽,咳出含有血样的黏液[2]。剖检可见病禽喉头、气管黏膜肿胀、出血和糜烂。鸡传染性喉气管炎于1925年在美国报道后现已遍及世界许多地区。本病传播快、死亡     

免疫失败引发传染性喉气管炎

鸡传染性喉气管炎(ILT)是鸡的一种由传染性喉气管炎病毒(ILTV)引起的急性接触性呼吸道传染病。病毒ILTV属疱疹病毒科、a-疱疹病毒亚科,具有疱疹病毒群的所有特征。发病早期患部细胞有核内包涵体。该病的特征是呼吸困难、气喘、咳嗽,严重的咳出血样的分泌物,喉头和气管黏膜上皮肿     

1株鸡传染性喉气管炎病毒的分离和鉴定

鸡传染性喉气管炎是危害养鸡业的一种重要的病毒性传染病,各种日龄的鸡均易感。临床表现为呼吸困难,解剖可见喉头和气管出血、充血并有大量黏液渗出为主要病变特征。青海省西宁市某养鸡场饲养的蛋鸡20%出现类似的临床症状,部分鸡死亡,剖检可见喉头气管出血及大量黏液,临床初步诊断为鸡传染性喉气管炎病毒感染。取送检的喉头和气管组织进行实验室病毒分离和鉴定,通过病毒的SPF鸡胚分离、血清学和分子生物学PCR检测,最终确诊该养鸡场发生了鸡传染性喉气管炎病毒感染并分离到致病毒株。     

鸡传染性喉气管炎病毒的分离和TK基因鉴定

从临床表现以呼吸困难、喉头出血为主要特征的某蛋鸡场患鸡喉头和气管等组织分离到一株病毒。该分离毒无血凝特性,应用检测ILTVTK基因的PCR能从分离毒中扩增出大小为427bp的特异性目的片段。测序结果与GenBank收录的ILTV不同毒株序列的同源性为100%。结果初步表明该分离毒为鸡传染性喉气管炎病毒(命名为ILTV-FJ)。     

鸡传染性喉气管炎及其防治

鸡传染性喉气管炎（ILT）是由鸡传染性喉气管炎病毒（ILTV）引起的一种急性、高度接触性呼吸道传染病。其特征是呼吸困难，咳嗽和咳出血样渗出物或黄色干酪样假膜，剖检可见喉头、气管黏膜肿胀、大面积出血，最终糜烂、坏死。     

鸡传染性喉气管炎及其防治

鸡传染性喉气管炎（ILT）是由鸡传染性喉气管炎病毒（ILTV）引起的一种急性、高度接触性呼吸道传染病。其特征是呼吸困难，咳嗽和咳出血样渗出物或黄色干酪样假膜，剖检可见喉头、气管黏膜肿胀、大面积出血，最终糜烂、坏死。     

鸡传染性喉气管炎诊断与防制的研究进展

传染性气管炎(Infectious Laryngotracheitis，ILT)是由疱诊病毒科、a-疱疹病毒亚科的喉气管炎病毒引起鸡的一种急性、高度接触性呼吸道传染病，其主要特征表现为病鸡表现困难、喘气、咳嗽及咳出带血黏液，喉头气管黏膜肿胀，糜烂和出血，蛋鸡产蛋率下降和较高的死亡率。     

Comparison of diagnostics techniques in an outbreak of infectious laryngotracheitis from meat chickens

Various diagnostics techniques were compared for their ability to detect infectious laryngotracheitis (ILT) during an outbreak in chickens aged between 4 and 21 wk. Gross lesions ranged from excess mucus to accumulation of fibrinonecrotic exudate in the larynx and trachea. Syncytial cells with intranuclear inclusion bodies were found in sinus, conjunctiva, larynx, trachea, lung, and air sac. Virus isolation in chicken embryos was attempted in every case. Negative-stain electron microscopy detected herpesvirus in only 6% of the cases. Yet, isolation of ILT virus in the chorioallantoic membrane was presumed by histology in >20% of the samples and confirmed by fluorescent antibody (FA) in 35% of the embryos inoculated with conjunctivas or tracheas from affected birds. Overall, results from histology and FA tests were highly correlated. FA test has the advantage over histology of being diagnostically specific for ILT virus. Polymerase chain reaction was the most sensitive test and detected the viral DNA even in cases where histology and FA were negative. ILT virus DNA was quantified by real-time polymerase chain reaction (Re-Ti ILTV). Histologic and FA results from larynx and trachea were negative if the concentration of the viral DNA was < or =4 of log10. A viral DNA concentration higher than log10 4, as determined by Re-Ti ILTV, was required for clinical ILT to be manifested.     

Gallid-1 herpesvirus infection in the chicken. 3. Reinvestigation of the pathogenesis of infectious laryngotracheitis in acute and early post-acute respiratory disease

Specific-pathogen-free chickens were infected via the trachea when 4 weeks old with 2000 plaque-forming units (PFU) of the virulent Australian infectious laryngotracheitis (ILT) virus strain CSW-1. Titers of ILT virus in the trachea were greatest (10(7.0) PFU/ml in washings, 10(6.0) PFU/g of tissue) 2-4 days postinfection (PI). Infectivity then declined rapidly, to become undetectable by 7 days PI, although highly localized areas of ILT antigen in the tracheal epithelium were occasionally observed by fluorescent antibody staining at 7 and 8 days PI. Tracheal organ cultures established 7 and 8 days PI provided no evidence of latent ILT virus infection at this immediate post-acute stage of pathogenesis. ILT virus was not isolated from peripheral blood leukocytes or lymphoid organs (spleen, bursa, thymus). ILT virus was found in the trigeminal ganglia and/or brain in 14 of 36 chickens (40%) examined between 4 and 7 days after intratracheal inoculation, but it was not in these tissues in five chickens examined at 8 days PI. Virus was also detected at 6 days PI in the trigeminal ganglia in one of five chickens infected by the conjunctival route. These data indicate that the early pathogenesis of ILT (CSW-1) infection frequently involves the tissues of the nervous system. In acute ILT in 4-week-old chickens, interferon-alpha/beta activity was not detectable in serum or tracheal exudates within 14 days PI, but tracheal washings contained significant virus-neutralizing activity by 7 and 8 days PI. In 3-day-old chickens infected via the trachea with 200 PFU of ILT CSW-1, the clearance of ILT virus from the trachea was similar to that observed in 4-week-old chickens, but ILT virus spread systemically to the livers of 20% by 5-7 days PI.     

抗鸡传染性喉气管炎重组鸡痘病毒基因工程疫苗同居感染试验

疫苗的接触传播是疫苗免疫接种需要考虑的重要因素,为了检测重组鸡痘病毒载体疫苗水平传播的能力,对隔离条件下饲养的SPF鸡用重组鸡痘病毒基因工程疫苗接种,同时设立非免疫对照鸡,饲养期间特意延长清粪时间以增加感染的机会,1个月之后攻击传染性喉气管炎WG株强毒和鸡痘102株强毒,疫苗免疫鸡全部获得保护,而非免疫鸡则全部发病.在试验动物饲养场的自然条件下,将免疫鸡和试验对照两组鸡饲养在同一个鸡舍内,让疫苗毒的传播更接近自然条件.在每个月的攻毒试验中,对照鸡都没有获得对鸡痘和传染性喉气管炎强毒的保护.在疫苗免疫期间进行连续5个月的跟踪检测,同居未免疫鸡没有检测到抗传染性喉气管炎病毒gB抗体.这些实验结果表明抗鸡传染性喉气管炎重组鸡痘病毒基因工程疫苗不能通过接触传播.     

抗禽流感或传染性喉气管炎两种重组鸡痘病毒疫苗联合免疫的相互影响

“表达H5N1禽流感病毒HA和NA基因的重组鸡痘病毒（rFPV—AI）疫苗”以及“表达传染性喉气管炎病毒gB基因的重组鸡痘病毒（rFPV—ILT）疫苗”均已在实现商业化生产。由于两种疫苗使用了相同的载体病毒,如何使用才能减少相互干扰而产生最好的免疫效果。本研究设计了三个试验组：1）免疫rFPV—AI后间隔4周接种rFPV—ILT;2）rFPV—AI和rFPV—ILT混合后接种;3）将rFPV—AI和rFPV—ILT分别在两个翅膀同时免疫。结果表明,试验鸡接种rFPV—AI后4周接种rFPV—ILT,对传染性喉气管炎病毒WG株攻击的保护率为60％（6／10）,低于rFPV—ILT单独免疫组的保护率（100％,10／10）;rFPV—AI和rFPV—ILT混合后免疫组对禽流感病毒强毒攻击的保护率为80％（8／10）,对传染性喉气管炎病毒强毒攻击的保护率为70％（7／10）,而rFPV—AI和rFPV—ILT分两点同时接种对两种病毒攻击均能产生完全保护。本试验结果建议将这两种相同载体的重组病毒疫苗分两点同时接种以避免相互之间的干扰。     

Increased virulence of modified-live infectious laryngotracheitis vaccine virus following bird-to-bird passage.

Modified-live (ML) infectious laryngotracheitis (ILT) vaccine viruses, both tissue-culture-origin (TCO) and chicken-embryo-origin (CEO), were passaged 20 times in specific-pathogen-free chickens. After serial bird-to-bird passage, increased virulence was observed for CEO virus but not TCO virus. Increased mortality and increased severity and duration of respiratory disease were observed in chickens inoculated with chicken-passaged CEO viruses; only mild respiratory disease (no mortality) occurred in chickens inoculated with chicken-passaged TCO viruses. These findings suggest that ML ILT vaccine viruses may increase in virulence after bird-to-bird passage.     

Mild infectious laryngotracheitis in broilers in the southeast

During 2001, a mild infectious laryngotracheitis virus (ILTV) infection occurred in broiler flocks in the southeastern United States. Clinical signs included mild tracheitis, swollen sinuses, and conjunctivitis, with no increased mortality and minimal serologic response. Infrequent intranuclear inclusion bodies with or without syncytial cell formation were observed in eyelid, trachea, and larynx and in the chorioallantoic membrane of infected embryos. Immunohistochemistry and a nested infectious laryngotracheitis polymerase chain reaction (ILT PCR) were utilized to confirm the presence of ILTV nucleic acid in fixed tissues. In addition, 2-wk-old specific-pathogen-free (SPF) birds inoculated with field material exhibited the mild signs observed in broilers in the field. Tracheal swabs and tissues taken from these SPF birds were also positive by nested ILT PCR. Restriction fragment length polymorphism analysis of ILT PCR products indicated that ILT virus associated with mild respiratory disease in the southeast is related to the chicken embryo origin vaccine type strains.     

Protection against infectious laryngotracheitis by in ovo vaccination with commercially available viral vector recombinant vaccines

Infectious laryngotracheitis (ILT) is a highly contagious respiratory disease of chickens caused by infectious laryngotracheitis virus (ILTV). The disease is mainly controlled through biosecurity and by vaccination with live-attenuated vaccines. The chicken embryo origin (CEO) vaccines, although proven to be effective in experimental settings, have limited efficacy in controlling the disease in dense broiler production sites due to unrestricted use and poor mass vaccination coverage. These factors allowed CEO vaccines to regain virulence, causing long lasting and, consequently, severe outbreaks of the disease. A new generation of viral vector fowl poxvirus (FPV) and herpesvirus of turkey (HVT) vaccines carrying ILTV genes has been developed and such vaccines are commercially available. These vaccines are characterized by their lack of transmission, lack of ILTV-associated latent infections, and no reversion to virulence. HVT-vectored ILTV recombinant vaccines were originally approved for subcutaneous HVT or transcutaneous (pox) delivery. The increased incidence of ILTV outbreaks in broiler production sites encouraged the broiler industry to deliver the FPV-LT and HVT-LT recombinant vaccines in ovo. The objective of this study was to evaluate the protection induced by ILTV viral vector recombinant vaccines after in ovo application in 18-day-old commercial broiler embryos. The protection induced by recombinant ILTV vaccines was assessed by their ability to prevent clinical signs and mortality; to reduce challenge virus replication in the trachea; to prevent an increase in body temperature; and to prevent a decrease in body weight gain after challenge. In this study, both recombinant-vectored ILTV vaccines provided partial protection, thereby mitigating the disease, but did not reduce challenge virus loads in the trachea.     

Epidemic of infectious laryngotracheitis in Italy: characterization of virus isolates by PCR-restriction fragment length polymorphism and sequence analysis

Between May 2007 and October 2008, 34 outbreaks of mild to moderate forms of infectious laryngotracheitis (ILT) occurred in commercial broiler flocks in Italy. Affected birds showed watery eyes, conjunctivitis, nasal discharge, reduction of feed and water consumption, and gasping with expectoration of blood-stained mucus. The mortality rate was < 10%. Gross lesions consisted of conjunctivitis, excess of mucus, blood, or presence of diphtheritic membranes in trachea. A real-time PCR assay was performed to confirm the presence of ILT virus (ILTV) DNA in tracheal tissue homogenates. Twenty-three ILTV isolates were propagated on the chorion-allantoic membrane of embryonated chicken eggs showing typical plaques. PCR combined with restriction fragment length polymorphism and gene sequencing of isolates showed a high genetic correlation between field strains and chicken embryo origin vaccines.     

ILTV gB基因与鸡IL-18基因共表达DNA疫苗的免疫原性

本试验构建了能分别或同时表达ILTV gB和IL-18基因的重组质粒pIRES-gB、pIRES-IL18、pIRES-gB/IL18。将重组质粒通过腿部肌肉多点注射免疫21日龄雏鸡,35日龄加强免疫1次,二免后2周用ILTV HN1株进行攻毒。pIRES-gB/IL18和pIRES-gB+pIRES-IL18免疫雏鸡后均能促进外周血T淋巴细胞亚群数量和血清中特异性抗体水平的增加,能明显增强ILTV DNA疫苗对强毒的攻击保护,但pIRES-gB/IL18免疫组要优于pIRES-gB+pIRES-IL18混合免疫组及其他对照组,差异显著或极显著。结果表明,鸡IL-18能明显增强ILTV DNA疫苗的免疫原性。     

宿主细胞粘附相关基因表达与鸡传染性喉气管炎病毒组织嗜性相关性的研究

为探究宿主细胞粘附相关基因与鸡传染性喉气管炎病毒(ILTV)感染组织嗜性的相关性,本研究采用ILTV特异性定量PCR方法检测了ILTV NP-3毒株感染雏鸡后ILTV在不同组织中的分布情况,并通过RT-qPCR方法在转录水平上检测了攻毒后不同组织中细胞粘附相关基因CDH11、NEGR1和VCAN的转录水平。结果显示,ILTV感染雏鸡后在喉头、气管、哈德氏腺及骨髓中病毒载量相对较高,而在法氏囊、脾脏、胸腺和肝脏中呈阴性。同时,ILTV感染显著促进了细胞粘附相关基因CDH11、NEGR1和VCAN在组织中的表达,且与ILTV在相应组织中的分布呈显著相关性(P<0.05),表明宿主细胞粘附活性对ILTV组织嗜性具有重要作用,具体机制有待进一步研究。本研究探索了ILTV感染组织嗜性与细胞粘附分子间的关系,以期为新型免疫制剂的研制奠定了基础。