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1.
Serological analysis was performed to detect Toxoplasma gondii and Neospora caninum infection in seals in Hokkaido. Serum samples were collected from 322 Kuril harbor seals (Phoca vitulina stejnegeri) at Nosappu, Akkeshi and Erimo, from 46 spotted seals (P. largha) at Nosappu, Erimo, Yagishiri Island, Hamamasu and Syakotan, and from 4 ribbon seals (P. fasciata) and a bearded seal (Erignathus barbatus) at Nosappu between 1998 and 2006. Recombinant surface antigen of T. gondii (SAG2t) and N. caninum (NcSAG1t) were used as antigens for ELISA to detect antibodies. Antibodies against SAG2t were detected from 4% of 77 Kuril harbor seals at Nosappu in 2005. Antibodies against NcSAG1t were detected from 2% (1/66) in 2003, 5% (4/79) in 2004 and 10% (8/77) in 2005 of Kuril harbor seals and 11% of 9 spotted seals in 2004 sampled at Nosappu. Eight percent of 12 Kuril harbor seals from Akkeshi and 25% of 4 spotted seals from Erimo in 2005 also contained antibodies against NcSAG1t. These suggest sporadic infection of T. gondii and N. caninum in Kuril harbor seals and spotted seals in Hokkaido. Of the ELISA-positive seals, 2 seals having anti-SAG2t antibodies and 3 seals having anti-NcSAG1t antibodies in 2005 were judged to be juveniles that have no maternal antibodies. These suggest that the protozoan infections have occurred in recent years. Infection of terrestrial protozoa such as T. gondii and N. caninum in seals indicates that the sea environment has been contaminated with protozoa.  相似文献   

2.
For proper management and conservation of the Kuril harbor seal (Phoca vitulina stejnegeri) through disease control, serological analysis was performed for influenza A virus infection in free-ranging seals in Hokkaido, Japan. Serum samples were collected from seals at Nosappu (231 seals), Akkeshi (16) and Erimo (75), between 1998 and 2005, and were analyzed by ELISA. Antibodies to the influenza A virus were detected only in seals from Nosappu. The incidences were 11% (1/9), 3% (2/66), 12% (7/59) and 6% (5/77) in 1998, 2003, 2004 and 2005, respectively. These suggest sporadic infection. Because antibody-positive seals included juvenile seals in each year, the infections were considered to have been circulated since no later than the late 1990s until recent years. ELISA-positive sera were analyzed by hemagglutination inhibition (HI) tests to determine the subtypes. Antibodies to the H3 and H6 subtypes were detected in 10 and 2 sera, respectively. Two of the sera that had antibodies to the H6 subtype also had antibodies to the H3 subtype. These two seals were considered to have been infected with both the H3 and H6 subtypes. This is the first investigation to find antibodies to the H6 subtype in seals. Although the H6 subtype had been isolated only from avians, genetic analysis had suggested that the H6 subtype could become a novel mammalian pathogen. For definitive diagnosis, detection of the virus from the tissue or mucus of seals is required.  相似文献   

3.
Recently the isolation and characterisation of a morbillivirus which caused high mortality in common seals (Phoca vitulina) in 1988 have been reported. Because of the clinical and pathological similarity of the disease in seals to that of distemper in dogs, the name phocine distemper virus (PDV) has been proposed. There are marked differences in the virus-induced proteins of PDV compared to other morbilliviruses and the humoral immune response of moribund and dead seals to PDV was restricted to some of the internal antigens of PDV, similar to the response described earlier for canine distemper virus infection in dogs.  相似文献   

4.
Phocine distemper virus (PDV) caused thousands of deaths among harbor seals (Phoca vitulina) from the North Sea in 1988 and 2002. To examine the effects of different factors on the pathology of phocine distemper, we performed necropsies and laboratory analyses on 369 harbor seals that stranded along the Dutch coast during the 2002 PDV epidemic. Diagnostic tests for morbillivirus infection indicated a differential temporal presence of morbillivirus in lung and brain. Seals of 3 years or older were significantly more often IgG positive than younger seals. The most frequent lesions in PDV cases were bronchopneumonia, broncho-interstitial pneumonia, and interstitial emphysema. Extra-thoracic emphysema was rare in <1-year-olds compared with older seals, even though severe pneumonia was more common. PDV cases generally had empty stomachs and less blubber than by-caught seals from before the epidemic. In PDV cases involving older animals, lung, kidney, and adrenal weights were significantly increased. Bordetella bronchiseptica was isolated from lungs in two thirds of the PDV cases examined. Our results indicate that brain should be included among the tissues tested for PDV by RT-PCR; that either phocine distemper has a longer duration in older seals or that there are age-related differences in immunity and organ development; that dehydration could play a role in the course and outcome of phocine distemper; and that bacterial coinfections in lungs are more frequent in PDV cases than gross lesions suggest. These results illustrate how quantitative analysis of pathology data from such epidemics can improve understanding of the causative disease.  相似文献   

5.
Eight harbour seals (Phoca vitulina), two of them seronegative, six seropositive against PDV and a seronegative grey seal (Halichoerus grypus) were exposed to a low doses of a cell culture-propagated phocine distemper virus isolate (PDV 2558/Han 88). An intranasal route of inoculation was chosen. Clinical signs, resembling those of 1988's seal disease and seroconversion were observed in both seronegative harbour seals. One of them succumbed to the infection. The virus was not transmitted to another susceptible harbour seal which served as in-contact animal. Virus could be recovered from leucocytes of the diseased seals. Viremia was also present in a seropositive harbour seal that developed mild clinical signs; other seropositive seals were protected from clinical disease. The grey seal showed seroconversion upon inoculation, but did not develop any signs of disease. The humoral immune response of the seals plainly discriminated between homologous (PDV) and heterologous (canine distemper virus, CDV) virus as shown by virus neutralization tests and an antibody-binding assay (PLA).  相似文献   

6.
The influence of polychlorinated biphenyls (PCBs) on phocine distemper virus (PDV) infections in harbour seals (Phoca vitulina) was studied. Six out of ten seals had been conditioned with a defined mixture of PCB-congeners for several weeks. Following exposure to the cell culture-propagated PDV isolate 2558/Han 88 the complete clinical picture of "1988 seal plague" was provoked in all ten seals inoculated. Four out of six PCB-conditioned seals and two out of four seals not loaded with PCBs succumbed to the infection within three weeks post inoculation. With regard to the clinical course, duration of cell-associated viremia, PDV-antigen distribution in tissues of fatally infected seals and the humoral immune response to PDV no differences between PCB-loaded and unloaded seals were recognized. Evidence was obtained that the pathogenesis of experimental PDV-infection in harbour seals shares some features with those of canine distemper in terrestrial carnivores. In contrast, however, to experimental distemper infection of gnotobiotic dogs prompt development of high titres of PDV-specific IgG did not correlate with recovery from infection.  相似文献   

7.
The relapse of the outbreak of the phocine distemper virus in the Danish island of Anholt this June, emphasizes the importance of the topic among experts. During the phocine distemper virus (PDV) epidemic in 1988, a total of 23,000 harbour seals (Phoca vitulina) died. In 2002 a second outbreak of PDV resulted in the death of more than 30,000 harbor seals. Both epidemics originated near the Danish island of Anholt and spread to adjacent colonies. Additional centres of infection were observed in the Dutch Wadden Sea far from the infected Danish seal populations. Arctic seals and grey seals were considered as vectors. Grey seal populations may serve as a reservoir for PDV or act as subclinically infected carriers of the virus between Arctic and North Sea seal populations. Mixed colonies of grey and harbour seals are widely distributed in the North and Baltic Seas. The role of environmental contaminants and their potential impact on immune function are discussed. The duration and geographical patterns of the two PDV epidemics are compared.  相似文献   

8.
Of 57 seals hospitalized in the Norddeich Orphanage, 37 (65%) had died until 22nd of August, 1988, when the first collection of blood samples from the survivors commenced. All the sera including those obtained at a later date from the remaining animals had invariably higher neutralizing antibody titres against a phocine distemper virus (PDV) isolate than against canine distemper virus (CDV). The difference of mean titres was calculated to be more than 1.5 x log10 serum dilution. Peak titres demonstrated by a direct neutralization peroxidase-linked antibody (NPLA) assay reached 1/90,000. Attempts to isolate PDV in seal kidney cell cultures from heparinized blood samples collected from convalescent animals were not successful. From the increase in antibody titre following the last fatal case it was concluded that the devastating epidemic sweeping through the Norddeich Orphanage was primarily due to phocine distemper.  相似文献   

9.
The seal death in Danish waters 1988. 2. Virological studies.   总被引：2，自引：0，他引：2  
Mass abortions and high mortality were observed in harbour seals in Danish waters during 1988. Severe pneumonia and emphysema were typical clinical and post-mortem findings. Virological studies were carried out to identify the cause of the epidemic. Although seal herpesvirus (SeHV) was isolated in 23 of 114 animals this virus was subsequently found not to be the primary cause of the disease. Following the observation of seroconversion against canine distemper virus (CDV) in diseased seals (Osterhaus & Vedder 1988) a CDV-like morbillivirus (phocine distemper virus, PDV) was identified in organs of diseased animals. It is concluded that the epidemic was caused by introduction of PDV into a highly susceptible population presumably free from morbillivirus infection. The origin of PDV remains unknown but evidence of prior morbillivirus infection has been found in arctic and antarctic seal populations.  相似文献   

10.
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11.
Since 1988 morbilliviruses have been increasingly recognized and held responsible for mass mortality amongst harbour seals (Phoca vitulina) and other seal species. Virus isolations and characterization proved that morbilliviruses from seals in Northwest Europe were genetically distinct from other known members of this group including canine distemper virus (CDV), rinderpest virus, peste des petits ruminants virus and measles virus. An epidemic in Baikal seals in 1987 was apparently caused by a morbillivirus closely related to CDV so that two morbilliviruses have now been identified in two geographically distant seal populations, with only the group of isolates from Northwest Europe forming a new member of the genus morbillivirus: phocid distemper virus (PDV). Because of distemper-like disease, the Baikal seal morbillivirus was tentatively named PDV-2 in spite of its possible identity with CDV. The appearance of morbilliviruses in the Mediterranean Sea causing high mortality amongst dolphins should further increase the research activities on protection strategies for endangered species of marine mammals.  相似文献   

12.
A review of the 1988 European seal morbillivirus epizootic   总被引：2，自引：0，他引：2  
An epizootic of morbillivirus infection killed thousands of common seals (Phoca vitulina) in European seas in 1988. Most of the affected seals had respiratory signs and the main post mortem finding was acute pneumonia. The histopathological changes were similar to those of canine distemper. Six common porpoises (Phocoena phocoena) found stranded on the coast of Northern Ireland in late 1988 had similar lesions. Morbillivirus infection also killed several thousand Siberian seals (Phoca siberica) in Lake Baikal in 1987 and 1988. A morbillivirus (phocine distemper virus) has been isolated from affected seals in several European countries and studies of the antigenicity of the virus indicate that it has several unique epitopes that distinguish it from the other known morbilliviruses. Biochemical studies of the viral proteins, RNA and nucleotide sequence confirm that it is a new morbillivirus. There is seroepizootiological evidence of morbillivirus infection in Greenland harp seals (Pagophilus groenlandicus), ringed seals (Phoca hispida) and Dutch common seals several years before the 1988 epizootic. Antibodies to a morbillivirus have also been found in bottlenose dolphins (Tursiops truncatus) from the eastern coast of the USA. Further studies are required to determine whether these sea mammal populations have been infected with phocine distemper virus.  相似文献   

13.
Antibody titres to selected pathogens (canine adenovirus [CAV-2], feline herpesvirus [FHV], phocine herpesvirus [PHV-1], canine distemper virus, dolphin morbillivirus [DMV], phocine distemper virus [PDV], parainfluenza virus type 3 [PI3], rabies virus, dolphin rhabdovirus [DRV], canine coronavirus, feline coronavirus, feline leukaemia virus, Borrelia burgdorferi and Toxoplasma gondii) were determined in whole blood or serum samples from selected free-ranging terrestrial carnivores and marine mammals, including cougars (Fellis concolor), lynxes (Fellis lynx), American badgers (Taxidea taxus), fishers (Martes pennanti), wolverines (Gulo gulo), wolves (Canis lupus), black bears (Ursus americanus), grizzly bears (Ursus arctos), polar bears (Ursus maritimus), walruses (Odobenus rosmarus) and belugas (Delphinapterus leucas), which had been collected at several locations in Canada between 1984 and 2001. Antibodies to a number of viruses were detected in species in which these infections have not been reported before, for example, antibodies to CAV-2 in walruses, to PDV in black bears, grizzly bears, polar bears, lynxes and wolves, to DMV in grizzly bears, polar bears, walruses and wolves, to PI3 in black bears and fishers, and to DRV in belugas and walruses.  相似文献   

14.
Forty Caspian seals were surveyed seroepidemiologically between 1993 and 1998 around the times of mass mortality that occurred in 1997 in the Caspian Sea and seven Baikal seals were also surveyed in 1998. Virus neutralizing tests and ELISA clearly suggested that distemper virus epidemic was caused in Caspian seals before the spring of 1997 and that CDV infection continued to occur in Lake Baikal in recent years.  相似文献   

15.
Mass mortality in seals caused by a newly discovered morbillivirus   总被引：2，自引：0，他引：2  
During a recent disease outbreak among harbour seals (Phoca vitulina) in the North and Baltic seas, more than 17,000 animals have died. The clinical symptoms and pathological findings were similar to those of distemper in dogs. Based on a seroepizootiological study, using a canine distemper virus (CDV) neutralization assay, it was shown that CDV or a closely related morbillivirus (phocid distemper virus-PDV) was the primary cause of the disease. The virus was isolated in cell culture from the organs of dead seals and characterized as a morbillivirus by serology (immunofluorescence neutralization and enzyme-linked immunosorbent assays) and by negative contrast electron microscopy. Experimental infection of SPF dogs resulted in the development of mild clinical signs of distemper and CDV-neutralizing antibodies. The disease was reproduced in seals by experimental inoculation of organ material from animals that had died during the outbreak. However, seals that had been vaccinated with experimental inactivated CDV vaccines were protected against this challenge. This fulfilled the last of Koch's postulates, confirming that the morbillivirus isolated from the seal organs, was the primary cause of the disease outbreak. The recent demonstration of the presence of a similar virus in Lake Baikal seals (Phoca sibirica), which infected these Siberian seals 1 year before the northwestern European seals were infected, raises new questions about the origin of this infectious disease in pinnipeds.  相似文献   

16.
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17.
H3N8 canine influenza virus (H3N8 CIV) was first reported as a novel canine respiratory pathogen in racing greyhounds and shelter dogs in the U.S.A. in 2004. Phylogenetic analyses determined that this host-adapted pathogen originated from interspecies transmission of an equine influenza virus (EIV), but it is unknown when the transmission occurred prior to discovery in 2004. The objective of this study was to determine if racing greyhound and shelter dog sera collected from 1984 to 2004 had serological evidence of exposure to H3N8 CIV or EIV. Archived sera from 702 racing greyhounds and 1568 shelter dogs were tested for H3 antibodies to the original 2004 CIV isolate, as well as EIV isolates from 1991 to 1999. None of the racing greyhounds from 1984 and 1985 had detectable H3 antibodies. One of the shelter dogs, which entered a north Florida shelter in 2004, was seropositive. For racing greyhounds sampled from 1999 to 2004, 133/520 (26%) dogs had antibodies to both CIV and EIV H3 proteins. The annual seroprevalence was 27% in 1999, 28% in 2000, 10% in 2001, 1% in 2002, 41% in 2003, and 28% in 2004. The odds of H3 seropositivity were greater among dogs that raced > or =6 months, raced on > or =2 tracks, and raced in 1998, 2002, and 2003. Many of the seropositive dogs raced at tracks that were involved in 'kennel cough' epidemics in 1998-1999 and 2002-2003. Based on serological evidence, a H3N8 canine influenza-like virus was circulating in racing greyhounds in the U.S.A. as early as 1999.  相似文献   

18.
基因序列分析确诊大熊猫的犬瘟热病毒感染   总被引：7，自引：0，他引：7  
直接从死亡大熊猫肝脏提取细胞总 Ｒ Ｎ Ａ,经反转录后用犬瘟热病毒的 １ 对引物扩增出了约 ３２０ ｂｐ 的片段。此产物经纯化、序列分析表明,其片段 ２ 个引物间长度为 ２８１ ｂｐ,与预计片段大小相同。此毒株在核苷酸和氨基酸水平与北京犬等 ４ 个野毒株、哈尔滨犬野毒株、某疫苗弱毒株、 Ｏｎｄｅｒｓｔｅｐｏｏｒｔ 弱毒株和海豹瘟热病毒 ２ 型毒 株的 同源 性分 别为 ９２２％ 和 ９８９％ 、９２５％ 和 ９８９％ 、９１５％ 和 ９４６％ 、９２９％ 和 ９８９％ 、９８２％ 和 １００％ 。这样就进一步确定了大熊猫的犬瘟热病毒感染。  相似文献   

19.
The present study was designed to identify 15 beta-hemolytic streptococci isolated during a period between 1988 and 2005 from nine harbour seals and six grey seals from various origins of the North Sea. All isolates were identified as Streptococcus equi subsp. zooepidemicus. The bacteria were additionally investigated for relatedness by restriction fragment length polymorphism analysis of PCR amplified 16S-23S rDNA intergenic spacer region and gene szp and by macrorestriction analysis of chromosomal DNA of the strains by pulsed field gel electrophoresis. The molecular analysis yielded identical or closely related patterns within the strains of the present study and with the S. equi subsp. zooepidemicus strains isolated from harbour seals of German North Sea which were investigated previously [Akineden, O., Hassan, A.A., Alber, J., El-Sayed, A., Estoepangestie, A.T.S., L?mmler, C., Weiss, R., Siebert, U., 2005. Phenotypic and genotypic properties of S. equi subsp. zooepidemicus isolated from harbor seals (Phoca vitulina) from the German North Sea during the phocine distemper outbreak in 2002. Vet. Microbiol. 110, 147-152]. This indicates that this single or closely related bacterial clone existed during both phocine distemper virus epidemics in 1988 and 2002 and that a direct transmission of the strains has occurred between two seal species and between seal populations of far distant regions possibly with grey seals as a vector.  相似文献   

20.
From 16 (14%) out of 112 dead or euthanized seals originating from wildlife and seal orphanages phocine morbillivirus was isolated. The majority of viral isolates in cell cultures was obtained from lung homogenates of 15 out of 71 free-ranging seals (21%). The virus was isolated by longterm cultivation in roller cultures of seal kidney cells. The phocine morbillivirus was detected by typical cytopathogenic alteration and by peroxidase-linked antibody (PLA) assay, respectively. A neutralization test based on PLA was used for antibody detection in seals using a canine distemper virus (CDV) strain and in parallel one of the phocine morbillivirus isolates. All sera tested were proven to contain neutralizing antibodies of higher titres against the latter virus than against the CDV strain. Several seals furnished morbillivirus isolates and at the same time exhibited neutralizing antibodies of low to medium titres. No viral isolates were obtained from the majority of sick animals with moderate to high neutralizing titres (greater than 1/1,000). The significance of these findings is discussed in relation to the cause of the mass mortality amongst seals observed in 1988 in the Bay of Heligoland.  相似文献   

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