关键词： bats   immunocompetence   mites   reproduction  

摘要： Given the intimate association in host-parasite systems, parasites are expected to initiate their own reproduction when vulnerable hosts become abundant and/or when adult hosts are less resistant. In this study, we examined the variation in the intensities of a blood-sucking mite (Spinturnix myoti, Acarina) with respect to the reproductive cycle and immunocompetence of its host, the greater mouse-eared bat Myotis myotis. Reproductive, pregnant females were less immunocompetent and harboured more parasites than nonreproductive females, whilst, during lactation, immunocompetence was positively associated with female body mass. There was a dramatic increase in the T-cell response of gravid females with the advancement of gestation, which coincided with a diminution of individual parasite loads and a progressive switch of parasites from adults to juveniles. The latter not only harboured greater numbers of mites than adult female bats, but they also exhibited gravid parasites in higher proportions, indicating that juvenile hosts are more attractive for parasite reproduction than adult females.

关键词： 乙脑病毒   蝙蝠   血清   贮存宿主   流行病学  

摘要： 目的 :进一步探索蝙蝠在乙脑病毒贮存宿主方面的作用。方法 :病毒分离、微量血凝抑制试验 (HI)、间接免疫荧光试验 (IFAT)、电镜和病理检查。结果 :从蝙蝠血中分离到两株乙脑病毒。结论 :蝙蝠在乙脑病毒在自然界中的贮存和扩散方面具有重要的流行病学意义。

关键词： 血液/病毒学   脑/病毒学   长尾猴   黑   翼手目   疾病传播   垂直   胎儿/病毒学   肾/病毒学   肺/病毒学   副黏病毒科感染/病理学   副黏病毒科感染/传播   副黏病毒科感染/病毒学   副黏病毒亚科/免疫学   副黏病毒亚科/分离和提纯   胎盘/病毒学   妊娠并发症   感染性/病毒学   脾/病毒学   子宫/病毒学   Vero细胞   动物   女(雌)性   豚鼠   妊娠  

摘要： Antibodies to Hendra virus (HeV) have been found in a high percentage of fruit bats (Pteropus spp.) in Australia, indicating a possible reservoir for the virus. The aim of the experiments reported here was to investigate transplacental infection as a possible mode of transmission of the virus in fruit bats and other animals. In a first experiment, 18 pregnant guinea-pigs in the mid-stage of gestation were inoculated with HeV, as an experimental model in a conventional laboratory animal. Nine developed HeV disease as confirmed by viral isolation, histopathology and immunohistochemistry. In five of the nine clinically affected guinea-pigs there was necrosis and strong positive immunostaining in the placentas in an indirect immunoperoxidase (IPX) test for HeV antigen. One of these five guinea-pigs aborted and HeV was isolated from its three fetuses, one of which was also positive to the IPX test. In three other sick guinea-pig darns, virus was isolated from fetuses, and there was positive immunostaining in two of the latter. In a second experiment, four fruit bats were inoculated with a Similar dose of HeV. (A further four guinea-pigs inoculated at the same time developed severe disease, indicating adequate virulence.) Two bats were killed at 10 days post-inoculation and two were killed at 21 days. In these bats, no overt clinical disease was observed, but subclinical disease occurred, as indicated by viral isolation, seroconversion, vascular lesions and positive immunostaining. Transplacental transmission was indicated by positive immunostaining in two placentas and confirmed by isolation of virus from one of the associated fetuses. (C) 2000 Harcourt Publishers Ltd.

关键词： 蝙蝠   Lyssa   昆士兰州   澳大利亚   大洋洲  

关键词： 动物   动物园/病毒学   抗体   病毒/分析   抗原   病毒/分析   翼手目/病毒学   脑炎   病毒性/兽医学   脑炎   病毒性/病毒学   海马/病毒学   免疫组织化学   狂犬病病毒属/致病力   RNA   病毒/分析   逆转录聚合酶链反应   弹状病毒科感染/兽医学   弹状病毒科感染/病毒学   动物   小鼠  

摘要： In July 1997 a lyssavirus was isolated in Denmark from a colony of Egyptian flying foxes (Rousettus aegyptiacus) originating from a Dutch zoo. Sequencing of a 400 nucleotides coding region of the nucleoprotein and of a major part of the G-protein ectodomain encoding region of the newly isolated virus, revealed a very high similarity with European Bat Lyssavinus subtype la (EBL-1a). For characterisation of the recently isolated lyssavirus in frugivorous zoo bats, 16 frugivorous bats (Rousettus aegyptiacus) of the same colony and 80 mice were experimentally infected with the Rousettus isolate or with a well defined EBL-1a strain isolated from a Dutch insectivorous bat (Eptesicus serotinus). Inoculation viruses were titrated in mice to determine LD50's Of both isolates. Clinical signs of inoculated bats were recorded during 6 weeks. After showing neurological signs or at the end of the experimental infection all animals were euthanized. During the experimental infection sera and various tissues of inoculated bats were collected. Immunoassays, mouse inoculation tests (MIT) and polymerase chain reaction (PCR) were employed for detection of lyssavirus specific antibodies, antigen or RNA. Five bats inoculated with the Rousettus isolate and 2 bats inoculated with the Eptesicus isolate showed neurological signs. The remaining 9 bats survived and cleared the virus;at least under the detection limit of the used assays. Despite a much higher pathogenicity of the Rousettus isolate observed in mice, LD25's in bats were quite the same for the 2 isolates. The pathogenicity of both isolates suggested that like many other mammals, Rousettus aegyptiacus bats could be victims of lyssavirus infection besides reservoir hosts of infectious EBL1a. There was no significant difference in detecting the different lyssavirus isolates in Rousettus aegyptiacus bats. An employed immunoperoxidase staining (LP) method was very useful for sensitive detection and localization of lyssavirus antigen in

关键词： Australian bat lyssavirus   rabies   vaccination   prevention   zoonosis   fruit bats   megachiroptera   microchiroptera  

摘要： Veterinary surgeons in Australia must be aware of the emerging viral diseases and their potential effects on public health generally and, more specifically, on the veterinary profession. Australian bat lyssavirus was identified in 1996 and causes rabies-like disease in bats and humans. Two humans from Queensland have died of Australian bat lyssavirus encephalitis. Surveillance has shown that all Australian bats must be considered carriers of this new virus, therefore protective apparel should be used when handling bats. The pre-exposure regimen of inactivated rabies vaccine (Pasteur Merieux) provides protection against infection. As part of the preventive regimen, at risk groups, such as veterinary surgeons, should seriously consider preexposure rabies vaccination The post-exposure protocol involves administration of human rabies immunoglobulins and five intramuscular injections of the inactivated rabies vaccine.

关键词： Australian bat lyssavirus   bats   flying fox   histopathology   immunohistochemistry   rabies   lyssavirus  

摘要： Objective To describe the lesions and distribution of viral antigens in bats infected by Australian bat lyssavirus. Design A retrospective histopathological and immunohistochemical study of bats naturally infected with the virus. Procedure Tissues from 37 infected bats were examined. Nineteen flying foxes (fruit bats) and two insectivorous bats were examined in detail. Brains of another 16 flying foxes were poorly fixed and were examined less fully. Result Lesions varied considerably between individuals and, where present, were mostly those of nonsuppurative meningoencephalomyelitis and ganglioneuritis similar to lesions seen in rabies and rabies-like diseases. The number of cells with intracytoplasmic inclusion bodies (Negri bodies) was variable;none were seen in some bats. Intracytoplasmic vacuolation of neurons was a common finding. Lesions occurred throughout the central nervous system but were most frequent and severe in the hippocampus, thalamus and midbrain, and medulla oblongata and pens. Indirect immunoperoxidase tests far lyssavirus antigen reactions varied in intensity and distribution, but also occurred mostly in the hippocampus, thalamus and midbrain, and medulla oblongata and pens. In peripheral tissues, reactions were seen in autonomic ganglia, in nerve plexuses of the gastrointestinal tract, in nervous tissues within muscles and immediately adjacent to individual muscle fibres, in an adrenal medulla, and in epithelial tissues in one of eight salivary glands examined. Conclusion The main lesion in Australian bat lyssavirus infection is nonsuppurative inflammation similar to that seen in rabies and other rabies-like diseases, except that the number of Negri bodies is more variable. Reactions to immunoperoxidase tests for lyssavirus vary in intensity and distribution and may occur in both central and peripheral nervous systems. These reactions do not always occur in the salivary glands, even if brain infection is present.

关键词： 逆转录-聚合酶链反应   海南岛   登革热   蝙蝠   登革病毒   病毒基因RNA  

摘要： 采用1-4型登革病毒通用引物，用逆转录一聚合酶链反应（RT-PCR）检测海南岛登革热流行区蝙蝠脑细胞登革病毒基因RNA。在35例中，20例阳性；检测18例蝙蝠血清，3例阳性；检测三组埃及伊蛟，1组阳性。用单克隆荧光抗体技术检测20例登革病毒基因RNA阳性的蝙蝠脑细胞压印片，16例阳性，与RT-PCR检测登革热流行区登革病毒基因RNA阳性蝙蝠脑细胞的阳性符合率为80.00%。用PT-PCR检测非流行区蝙蝠脑细胞登革病毒基因RNA，均为阴性。本研究首次证实蝙蝠是登革病毒的贮存宿主，为登革热流行的有效控制提供了一定的科学依据。

关键词： Hendra virus   equine morbillivirus   fruit bat   horse   oat   vasculitis  

摘要： Objective To determine the infectivity and transmissibility of Hendra virus (HeV). Design A disease transmission study using fruit bats, horses and cats. Procedure Eight grey-headed fruit bats (Pteropus poliocephalus) were inoculated and housed in contact with three uninfected bats and two uninfected horses. In a second experiment, four horses were inoculated by subcutaneous injection and intranasal inoculation and housed in contact with three uninfected horses and six uninfected cats. In a third experiment, 12 cats were inoculated and housed in contact with three uninfected horses. Two surviving horses were inoculated at the conclusion of the third experiment: the first orally and the second by nasal swabbing. All animals were necropsied and examined by gross and microscopic pathological methods, immunoperoxidase to detect viral antigen in formalin-fixed tissues, virus isolation was attempted on tissues and SNT and ELISA methods were used to detect HeV-specific antibody. Results Clinical disease was not observed in the fruit bats, although six of eight inoculated bats developed antibody against HeV, and two of six developed vascular lesions which contained viral antigen. The in-contact bats and horses did not seroconvert. Three of four horses that were inoculated developed acute disease, but in-contact horses and cats were not infected. In the third experiment, one of three in-contact horses contracted disease. At the time of necropsy, high titres of HeV were detected in the kidneys of six acutely infected horses, in the urine of four horses and the mouth of two, but not in the nasal cavities or tracheas. Conclusions Grey-headed fruit bats seroconvert and develop subclinical disease when inoculated with HeV. Horses can be infected by oronasal routes and can excrete HeV in urine and saliva. It is possible to transmit HeV from cats to horses. Transmission from P poliocephalus to horses could not be proven and neither could transmission from horses to horses or horses

关键词： human rabies vaccines   protective immunity   bat rabies virus  

摘要： The demonstration of extensive differences in the antigenic makeups of the silver-haired bat rabies virus (SHBRV) and canine rabies virus (COSRV strains raised concerns as to whether current licensed rabies vaccines are sufficiently protective against SHBRV. NIH mouse protection test results show that both the human diploid cell culture rabies vaccine (HDCV) and the purified chicken embryo cell rabies vaccine (PCECV) protected against lethal infection with SHBRV as well as the canine rabies strain COSRV. However in this investigation, the potencies of both vaccines in mice were found to be significantly higher for. COSRV than for SHBRV. The in vivo protection data are confirmed by in vitro virus neutralizing antibody (VNA) test results which demonstrate that mice immunized with HDCV or PCECV develop significantly higher VNA titres against COSRV than against SHBRV. In contrast, VNA tests of sera from individuals immunized with HDCV or PCECV showed that humans, as opposed to mice, develop significantly higher VNA titres against SHBRV than against COSRV. These data suggest that HDCV and PCECV will protect humans against infection with the silver-haired bat rabies virus strain in addition to canine rabies virus strains. (C) 1998 Elsevier Science Ltd, All rights reserved.