Heckmann Julia, Enderlein Dirk, Piepenbring Anne K, Herzog Sibylle, Heffels-Redmann Ursula, Malberg Sara, Herden Christiane, Lierz Michael
A Clinic for Birds, Reptiles, Amphibians and Fish, Justus Liebig University Giessen, Frankfurter Str. 91, 35392 Giessen, Germany.
B Institute of Virology, Justus Liebig University Giessen, Schubertstr. 81, 35392 Giessen, Germany.
Avian Dis. 2017 Mar;61(1):90-95. doi: 10.1637/11490-091316-Reg.
The aim of this study was to determine the natural infection route of parrot bornavirus (PaBV), the causative agent of proventricular dilatation disease (PDD) in psittacines. For this purpose, nine cockatiels ( Nymphicus hollandicus ) were inoculated orally, and nine cockatiels were inoculated intranasally, with a PaBV-4 isolate. To compare the results of the trials, the same isolate and the same experimental design were used as in a previous study where infection was successful by intravenous as well as intracerebral inoculation. After inoculation, the birds were observed for a period of 6 mo and tested for PaBV RNA shedding, virus replication, presence of inflammatory lesions, and PaBV-4 antigen in tissues, as well as specific antibody production. In contrast to the previous study involving intravenous and intracerebral infections, clinical signs typical for PDD were not observed in this study. Additionally, anti-PaBV antibodies and infectious virus were not detected in any investigated bird during the study. Parrot bornavirus RNA was detected in only four birds early after infection (1-34 days postinfection). Furthermore, histopathologic examination did not reveal lesions typical for PDD, and PaBV antigen was not detected in any organ investigated by immunohistochemistry. In summary, oral or nasal inoculation did not lead to a valid infection with PaBV in these cockatiels. Therefore it seems to be questionable that the formerly proposed fecal-oral transmission is the natural route of infection in immunocompetent adult or subadult cockatiels.
本研究的目的是确定鹦鹉腺病毒（PaBV）的自然感染途径，该病毒是鹦鹉中腺胃扩张病（PDD）的病原体。为此，用一株PaBV-4分离株对9只玄凤鹦鹉（虎皮鹦鹉）进行口服接种，对另外9只玄凤鹦鹉进行鼻内接种。为了比较试验结果，使用了与之前一项研究相同的分离株和相同的实验设计，在之前的研究中，通过静脉内和脑内接种成功实现了感染。接种后，对这些鸟观察6个月，并检测其PaBV RNA脱落、病毒复制、炎症病变的存在、组织中PaBV-4抗原以及特异性抗体的产生情况。与之前涉及静脉内和脑内感染的研究不同，本研究未观察到PDD的典型临床症状。此外，在研究期间，未在任何被调查的鸟中检测到抗PaBV抗体和传染性病毒。仅在感染后早期（感染后1 - 34天）在4只鸟中检测到鹦鹉腺病毒RNA。此外，组织病理学检查未发现PDD的典型病变，通过免疫组织化学在任何被调查的器官中均未检测到PaBV抗原。总之，口服或鼻内接种在这些玄凤鹦鹉中未导致有效的PaBV感染。因此，之前提出的粪 - 口传播是免疫功能正常的成年或亚成年玄凤鹦鹉的自然感染途径这一观点似乎值得怀疑。
