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1.
We isolated 24 Hav1 Neq1 and 18 Hav6 Nav3 influenza viruses from such free-living wild waterfowl as whistling swans, black-tailed gulls, and tufted ducks in western Japan in 1980. Two Hav1 Neq1 viruses isolated from a whistling swan and a black-tailed gull and a Hav6 Nav3 virus from a whistling swan were examined for their pathogenicity for chickens. Five-week-old specific-pathogen-free chickens were inoculated with the viruses intratracheally or intraperitoneally. Virus was recovered successfully from all the organs, including the brain, despite the absence of signs of disease. The intracerebral pathogenicity index scores obtained for the Hav1 Neq1 viruses were 0.43 and 0.87; the score for the Hav6 Nav3 virus was 0.43. No virus produced plaques in cultivated chick embryo fibroblast cells in the absence of trypsin. 相似文献
2.
The pathogenicity of three Australian fowl plague viruses, FPV-1, FPV-2, FPV-3, isolated during a natural outbreak of the disease varied for chickens, turkeys and ducks. FPV-1 and FPV-2 were pathogenic for chickens and turkeys, but not for ducks. However, these viruses were not highly pathogenic as they failed to cause illness or death in all birds that became infected. FPV-3 was non-pathogenic for the three species tested.The viruses spread from infected to in-contact birds, and more readily to ducks than to chickens or turkeys. All chickens and turkeys infected with the fowl plague viruses developed specific serum haemagglutination-inhibiting antibody which persisted for up to 85 days after infection. The titre of this antibody wan ed in six of 16 ducks over an 85-day period and two ducks failed to produce detectable specific HaI antibody despite being infected with the virus. 相似文献
3.
Yamamoto Y Nakamura K Kitagawa K Ikenaga N Yamada M Mase M Narita M 《Avian diseases》2007,51(3):744-749
To evaluate the possibility of virus transmission through feathers of call ducks, we performed two experiments, intranasal infection study and transmission study, using the Japanese H5N1 highly pathogenic avian influenza virus (HPAIV) A/chicken/Yamaguchi/7/2004 (Ck/Yama/7/04). In Experiment 1, 1-day-old, 2-wk-old, and 4-wk-old birds were inoculated intranasally with Ck/Yama/7/04. Birds in all age groups exhibited necrosis and/or viral antigens in the feather epithelium. Nonpurulent encephalitis and focal necrosis of the pancreas and heart also were common to inoculated birds. In Experiment 2, nine 2-wk-old birds that were orally inoculated with feathers of an infected call duck exhibited the nonpurulent encephalitis, necrosis of the feather epithelium, and focal necrosis of the pancreas and heart, accompanied by viral antigens. These lesions were similar to those in intranasal infection. Some birds were positive for the virus isolation from cloacal swabs and hemagglutination inhibition antibody. The infection was confirmed in seven of nine birds. This study confirmed that the Japanese HPAIV can replicate in the feather epithelium, causing necrosis in call ducks through the natural infection route. It also suggests that feathers of call ducks infected with Ck/Yama/7/04 can be a potential source of infection for unaffected birds in nature. 相似文献
4.
Runyu Yuan Jin Cui Shuo Zhang Lan Cao Xiaoke Liu Yinfeng Kang Yafen Song Lang Gong Peirong Jiao Ming Liao 《Veterinary microbiology》2014
In this study, we selected three H5N1 highly pathogenic avian influenza viruses (HPAIVs), A/Goose/Guangdong/1/1996 (clades 0), A/Duck/Guangdong/E35/2012 (clade 2.3.2.1) and A/Chicken/Henan/B30/2012 (clade 7.2) isolated from different birds in China, to investigate the pathogenicity and transmission of the viruses in terrestrial birds and waterfowl. To observe the replication and shedding of the H5N1 HPAIVs in birds, the chickens were inoculated intranasally with 106 EID50 of GSGD/1/96, 103 EID50 of DkE35 and CkB30, and the ducks and geese were inoculated intranasally with 106 EID50 of each virus. Meanwhile, the naive contact groups were set up to detect the transmission of the viruses in tested birds. Our results showed that DkE35 was highly pathogenic to chickens and geese, but not fatal to ducks. It could be detected from all the tested organs, oropharyngeal and cloacal swabs, and could transmit to the naive contact birds. GSGD/1/96 could infect chickens, ducks and geese, but only caused death in chickens. It could transmit to the chickens and ducks, but was not transmittable to geese. CkB30 was highly pathogenic to chickens, low pathogenic to ducks and not pathogenic to geese. It could be transmitted to the naive contact chickens, but not to the ducks or geese. Our findings suggested that H5N1 HPAIVs from different birds show different host ranges and tissue tropisms. Therefore, we should enhance serological and virological surveillance of H5N1 HPAIVs, and pay more attention to the pathogenic and antigenic evolution of these viruses. 相似文献
5.
The H5N1 type A influenza viruses classified as Qinghai-like virus (clade 2.2) are a unique lineage of type A influenza viruses with the capacity to produce significant disease and mortality in gallinaceous and anseriform birds, including domestic and wild ducks. The objective of this study was to determine the susceptibility and pathogenesis of chickens and domestic ducks to A/Whooper Swan/Mongolia/224/05 (H5N1) high pathogenicity avian influenza (HPAI) virus when administered through respiratory or alimentary routes of exposure. The chickens and ducks were more susceptible to the H5N1 HPAI virus, as evidenced by low infectious and lethal viral doses, when exposed by intranasal as compared to alimentary routes of inoculation (intragastric or oral-fed infected chicken meat). In the alimentary exposure pathogenesis study, pathologic changes included hemorrhage, necrosis, and inflammation in association with virus detection. These changes were generally observed in most of the visceral organs of chickens, between 2 and 4 days postinoculation (DPI), and are similar to lesions and virus localization seen in birds in natural cases or in experimental studies using the intranasal route. Alimentary exposure to the virus caused systemic infection in the ducks, characterized by moderate lymphocytic encephalitis, necrotized hepatitis, and pancreatitis with a corresponding demonstration of virus within the lesions. In both chickens and ducks with alimentary exposure, lesions, virus, or both were first demonstrated in the upper alimentary tract on 1 DPI, suggesting that the alimentary tract was the initial site affected upon consumption of infected meat or on gavage of virus in liquid medium. However, as demonstrated in the infectivity study in chickens, alimentary infection required higher exposure doses to produce infection as compared to intranasal exposure in chickens. These data suggest that upper respiratory exposure to H5N1 HPAI virus in birds is more likely to result in virus infection and transmission than will consumption of infected meat, unless the latter contains high doses of virus, as found in cannibalized infected carcasses. 相似文献
6.
Seven influenza viruses isolated from turkeys in Great Britain since 1963 were typed by haemagglutination inhibition and neuraminidase inhibition tests as: A/turkey/England/63 (Hav 1 Nav 3), A/turkey/England/66 (Hav 6 N2), A/turkey/England/69 (Hav 7 N2), A/turkey/Scotland/70 (Hav ? Neq 1), A/turkey/England/N28/73 (Hav 5 N2), A/turkey/England/110/77 (Hav 6 N2), A/turkey/England/647/77 /Hav 1 Neq 1). A/turkey/Scotland/70 failed to show a haemagglutinin relationship with any of the representative strains and may possess a hitherto unreported haemagglutinin subtype. Intravenous pathogenicity tests in six-week-old birds showed only A/turkey/England/63 to have high virulence for turkeys and chickens. A/turkey/England/69 produced some signs of disease in chickens and, to a lesser extent, turkeys but all other isolates were avirulent. 相似文献
7.
V S Hinshaw 《Avian diseases》1978,22(1):24-31
One influenza-A virus isolated from domestic turkeys in California in 1964 and two from migrating ducks in Delaware in 1973 were classified as Hav6 and Nav5, i.e., antigenically the same as A/Shearwater/Australia/1/72. The detection of antigenically related viruses in three different species over a ten-year period suggests a broad host range, contributing to continued circulation in nature. The turkeys suffered severe respiratory disease although infected migratory birds have not revealed signs of disease. These results suggest migratory birds, which travel over vast areas, as a source of influenza viruses infecting domestic species. 相似文献
8.
During an epornitic of velogenic viscerotropic Newcastle disease (VVND) in southern California, free-flying wild birds, captive and free-ranging semidomestic birds, and exotic birds were collected from the quarantine area to determine their role in the epizootiology of the disease. The VVND virus was isolated from 0.04% of 9,446 free-flying wild birds, 0.76% of 4,367 semidomestic birds, and 1.01% of 3,780 exotic birds examined. Three house sparrows and 1 crow directly associated with infected poultry flocks were the only free-flying wild birds from which VVND virus was isolated. Among semidomestic species, ducks, quail, chukars, pheasants, peafowl, pigeons, and doves were found to be infected. Psttacines, pittas, and toucans accounted for 92% of the VVND virus isolations from exotic birds. In addition, domestic Newcastle disease virus (NDV) was isolated from 0.29% of the free-flying wild birds, from 1.65% of the semidomestic birds, and from 0.19% of the exotic birds collected. Hemagglutination-inhibition against domestic NDV was demonstrated in 0.24% of 3,796 wild bird serums, 8.28% of 2,004 semidomestic bird serums, and 3.90% of 231 exotic bird serums tested. Although few free-flying wild birds were infected with VVND virus in this epornitic, the isolation of domestic NDV strains from free-flying wild ducks and mourning doves suggests the potential for transportation of NDV over long distances by migratory birds. 相似文献
9.
An avian influenza virus with surface antigens similar to those of fowl plague virus (Hav 1 Nav 2) was isolated in 1979 from 2 commercial turkey flocks in Central Texas. Two flocks in contact with these infected flocks developed clinical signs, gross lesions, and seroconversion but yielded no virus. This was the first recorded incidence of clinical avian influenza in Texas turkeys and only the second time that an agent with these surface antigens was isolated from turkeys in U.S. 相似文献
10.
Songserm T Viriyarampa AS Sae-Heng N Chamsingh W Bootdee O Pathanasophon P 《Avian diseases》2003,47(3):649-655
Pasteurella multocida group B, serotype 3, was isolated from sinusitis-affected khaki Campbell ducks. To study the role of P. multocida in sinusitis, commercial khaki Campbell ducks were experimentally infected with P. multocida alone or combined with Escherichia coli. In Expt. 1, experimental ducks were infected with P. multocida intranasally or ocularly. A comparison was done by intranasal inoculation with pooled nasal discharge from the affected ducks or phosphate-buffered saline. The ducks intranasally inoculated with the nasal discharge or P. multocida showed sinusitis. In Expt. 2, E. coli alone or a combination of P. multocida and E. coli was intranasally inoculated into experimental ducks. The ducks intranasally inoculated with the combination of P. multocida and E. coli had sinusitis, the same as found in the field but less severe than that of the field cases. Pasteurella multocida was already present in litter/floor of duck farms. We concluded that P. multocida played a role in induction of sinusitis. However, the sinusitis in ducks may be initiated by poor management, especially in the brooding period of ducks. 相似文献
11.
Saito T Watanabe C Takemae N Chaisingh A Uchida Y Buranathai C Suzuki H Okamatsu M Imada T Parchariyanon S Traiwanatam N Yamaguchi S 《Veterinary microbiology》2009,133(1-2):65-74
Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype have caused several rounds of outbreaks in Thailand. In this study, we used 3 HPAI viruses isolated in Thailand in January 2004 from chicken, quail, and duck for genetic and pathogenetic studies. Sequence analysis of the entire genomes of these isolates revealed that they were genetically similar to each other. Chickens, quails, domestic ducks, and cross-bred ducks were inoculated with these isolates to evaluate their pathogenicity to different host species. A/chicken/Yamaguchi/7/04 (H5N1), an HPAI virus isolated in Japan, was also used in the chicken and quail studies for comparison. All four isolates were shown to be highly pathogenic to chickens and quails, with 100% mortality by 10(6) EID50 inoculants of the viruses. They caused sudden death in chickens and quails within 2-4 days after inoculation. The mean death times (MDT) of quails infected with the Thai isolates were shorter than those of chickens infected with the same isolates. Mortality against domestic and cross-bred ducks ranged from 50 to 75% by intranasal inoculation with the 10(6) EID50 viruses. Neurological symptoms were observed in most of the inoculated domestic ducks and appeared less severe in the cross-bred ducks. The MDTs of the ducks infected with the Thai isolates were 4.8-6 days post-inoculation. Most of the surviving ducks infected with the Thai isolates had sero-converted until 14 dpi. Our study illustrated the pathobiology of the Thai isolates against different poultry species and would provide useful information for improving control strategies against HPAI. 相似文献
12.
Influence of the route of infection of Pasteurella anatipestifer on the clinical and immune responses of white Pekin ducks 总被引：1，自引：0，他引：1
The clinical, pathological and immunological responses were compared in ducklings infected by the intramuscular, oral and intranasal routes with virulent Pasteurella anatipestifer. Intramuscular challenge resulted in clinical signs of infection and caused 100 per cent mortality within three days. No disease signs or death were observed in the orally challenged ducks. Whereas intranasal inoculation caused no deaths, signs of infection were observed in two of 12 birds four days later. In the orally challenged group, low concentrations of antibodies (0.17 log2 to 4.5 log2) were detected in the tracheal washes of five of nine birds examined using an enzyme-linked immunosorbent assay. Humoral antibodies were detected in only one of these birds. In the intranasally infected group, serum antibody levels ranging in titre from 0.62 log2 to 6.2 log2 were found in four of nine birds examined over seven to 14 days following infection. Nine of the birds in this group were shown to have low concentrations of antibodies (0.50 log2 to 6.33 log2) in the tracheal washings. The demonstration of antibodies in the tracheal washings, but not in the serum of nine birds examined, suggested that a local immune response had occurred. However, these studies have shown that antibodies present on the tracheal surface can also be derived from antibodies given intraperitoneally. 相似文献
13.
J. Donaldson R. Dangarembizi B. Mtetwa M. T. Madziva K. H. Erlwanger 《Journal of animal physiology and animal nutrition》2014,98(5):867-874
To investigate the progressive effects of a high‐fat diet on erythrocyte osmotic fragility, growth performance and serum lipid concentrations in Guinea fowl and Muscovy ducks, 36 Guinea fowl and 36 Muscovy ducks were divided into two groups, for each species, and fed either a standard (STD = commercial poultry feed) or high‐fat diet (HFD = commercial poultry feed with 20% palm oil and 2% lard) for up to 12 weeks. After 4, 8 and 12 weeks on the diets, six birds from each group were euthanized and blood samples collected. Osmotic fragility was assessed by measuring the haemoglobin released by erythrocytes placed in serially diluted solutions of phosphate‐buffered saline, spectrophotometrically. Serum triglyceride and cholesterol concentrations were also determined. Fragiligrams from erythrocytes from both species of birds on the HFD were not different to those on the STD. However, Muscovy duck erythrocytes were more resistant to haemolysis compared with Guinea fowl erythrocytes. Final body mass and serum triglyceride levels were not significantly different (p > 0.05, anova ) between the birds in the HFD and STD groups, for both species of birds. In contrast, serum cholesterol levels were significantly higher in birds on the HFD compared with those on the STD, after 4, 8 and 12 weeks of feeding, for both species of birds. Feeding Guinea fowl and Muscovy ducks a high‐fat diet for up to 12 weeks resulted in hypercholesterolaemia but had no effect on final body mass, erythrocyte osmotic fragility or serum triglyceride concentrations in either bird species. 相似文献
14.
Host range of A/Chicken/Pennsylvania/83 (H5N2) influenza virus 总被引：1，自引：0，他引：1
The highly pathogenic A/Chicken/Penn./1370/83 (H5N2) avian influenza virus, which caused 80% mortality in chickens in Pennsylvania, produced only mild transient illness in experimentally infected pheasants, little or no clinical signs in ring-billed gulls and pigs, and no clinical signs in pekin ducks. Virus could be recovered from only the upper respiratory tract of gulls and pigs for 1-2 days. Infection in ducks resulted in intestinal replication of virus in only 1 out of 12 ducks. By contrast, pheasants shed virus in feces (10(4.7) EID50) for at least 15 days. These studies reinforce wildlife surveillance findings indicating that gulls and ducks are unlikely to have transmitted virus between chicken farms during the 1983 outbreak. Although experimental data suggest that wild gallinaceous birds such as pheasants are potentially capable of virus transmission, there has been no evidence of this from wildlife surveillance in Pennsylvania. Experimental infection of chickens with H5N2 virus isolated from wild ducks one year before the Pennsylvania outbreak or a gull virus (H5N1) isolated in the quarantine area in 1983 resulted in asymptomatic infections and virus replication occurring only in the upper respiratory tract. These studies suggest that if the first H5N2 virus infecting chickens in Pennsylvania originated from waterbirds, changes in host specificity and pathogenicity for chickens and other gallinaceous birds probably occurred during emergence of the Chicken/Penn./83 virus. It is recommended that attention be given in the future to the isolation of domestic poultry from contact with wild aquatic birds. 相似文献
15.
为了解两株高致病性禽流感病毒(HPAIV)的分子特征及其对不同宿主的致病性,本研究对DK/HuN/4/08和CK/GX/2/09进行全基因组序列的测定,分析结果表明:两个病毒分离株HA基因的裂解位点均具有HPAIV特有的基序(341RRR(R)KR345/346),并且均属于Clade2.3.2分支,基因组同源性在97.4%～98.3%之间。致病性试验显示,两个病毒分离株均能够以106EID50感染量在3 d内引起鸡全部死亡,并且各脏器均检测到高滴度的病毒含量;两者在SPF鸭中呈现不同的致病性,CK/GX/2/09在4 d内可以使感染鸭100%死亡,而DK/HuN/4/08只引起25%的死亡率;同样在小鼠试验中,两者致病力差异与在鸭体中的反应一致,其MLD50分别为1.63 log10EID50和6.2 log10EID50。本研究表明,这两株遗传背景相似的HPAIV在鸡、鸭和小鼠中的致病性不同,为进一步利用反向遗传技术研究这两株病毒对水禽和哺乳动物致病力差异的分子机制奠定了基础。 相似文献
16.
The H7N2 subtype of avian influenza virus (AIV) field isolate (H7N2/chicken/PA/3779-2/97), which caused the 1997-98 AIV outbreak in Pennsylvania, was evaluated for its infectivity, length of infection, and immune response in specific-pathogen-free (SPF) chickens. The composite findings of three clinical trials with various concentrations of virus indicated that this H7N2 subtype contained minimal pathogenicity for chickens. The concentration of the virus in the inoculum proved critical in the establishment of a productive infection in a chicken. Seven-day-old SPF chickens were not infected when inoculated with 10(0.7-2.0) mean embryo lethal dose (ELD50) of the H7N2 virus per bird. At this dose level, the immune response to this virus was not detected by the hemagglutination-inhibition (HI) test. Nonetheless, chickens at ages of 5 and 23 wk old tested were successfully infected when exposed to 10(4.7-5.7) ELD50 of H7N2 infectious doses per bird by various routes of administration and also by direct contact. Infected birds started shedding virus as early as 2 days postinoculation, and the period of virus shedding occurred mostly within 1 or 2 wk postinoculation (WPI). This H7N2 subtype of AIV induced a measurable immune response in all birds within 2 wk after virus exposure. Antibody titers were associated with AIV infectious doses and age of exposure of birds. Challenge of these infected birds with the same H7N2 virus at 5 and 10 WPI indicated the infective virus was recoverable from cloacal swabs at 3 days postchallenge and disappeared thereafter. In these challenged birds, the antibody levels as measured by the HI test spiked within 1-2 wk. 相似文献
17.
Mishra S Kataria JM Sah RL Verma KC Mishra JP 《Tropical animal health and production》2001,33(4):313-320
Newcastle disease viruses isolated from chickens and guinea fowl were characterized as viscerotropic, velogenic strains on the basis of their mean death time, intracerebral pathogenicity index, intravenous pathogenicity index and cloacal and conjunctival mean death time. The pathogenesis of the disease caused by both the strains was studied in 4-week-old guinea fowl. Both strains had an incubation period of 5 days and the birds showed dullness, depression, anorexia, diarrhoea and paralysis of the legs. They also exhibited nervous signs such as incoordination, muscle tremors and trembling of the neck at the advanced stage of the disease. Mortality reached 52% in the group infected with the chicken isolate but it was only 8% in the birds infected with the guinea fowl isolate. No specific changes were observed at post-mortem examination except haemorrhages at the tip of the glands of the proventriculus and in the caecal tonsil. Changes in the lymphoid organs and brain were always present in both the groups. Despite the low mortality, the guinea fowl isolated had multiplied in various organs in the birds. In both groups, the frequency of virus isolation increased from 5 to 10 days post infection. 相似文献
18.
为了研究H9N2亚型禽流感病毒（AIV）对樱桃谷肉鸭的致病性。本试验利用1株鸭源H9N2亚型AIV分别通过静脉注射和鼻内接种途径感染2周龄健康樱桃谷肉鸭,观察感染鸭的症状、排毒规律及组织学变化,流式细胞术分析外周血CD4^＋和CD8^＋T细胞变化规律,实时荧光定量（RT-qPCR）检测脾脏中细胞因子的表达水平,并测定血清HI抗体效价。结果显示,攻毒后,静脉注射组鸭出现体质量增长显著缓慢、呼吸道症状以及全身性感染,而鼻内接种组鸭无明显临床症状,仅发生局部感染;两攻毒组鸭泄殖腔较气管排毒量高且排毒时间长;外周血CD8^＋T细胞显著升高,并且脾脏IFNA、IFNB、IFNG和IL2表达水平上调,IL1B和IL6表达水平仅在静脉注射组上调;血清HI抗体水平低且维持时间短。结果表明,在实验室条件下,H9N2亚型AIV对樱桃谷肉鸭致病力较弱,仅静脉接种组引起鸭体质量增长缓慢及呼吸系统出血、淋巴细胞浸润。 相似文献
19.
Avian paramyxovirus type 1 infection of racing pigeons: 3 epizootiological considerations 总被引：1，自引：0，他引：1
During July to December 1983 birds in 192 racing pigeon lofts were confirmed as infected with paramyxovirus type 1 virus on the basis of disease signs alone when contact with infected cases was known (10) or with supporting serology (130), virus isolation (eight) or both (44). These outbreaks were mainly concentrated in south Wales (89) and Dorset (40). In all, 29 counties of Great Britain were involved. In the majority of outbreaks (69 per cent) activities associated with racing were strongly implicated in the spread of the disease but trade in birds, stray bird contact, loft visits and contact at shows were also possible methods of spread. Although considerable variation was seen in the pathogenicity of the viruses isolated from affected birds there were no apparent epizootiological links between isolates of similar virulence. 相似文献
20.
Yamamoto Y Nakamura K Kitagawa K Ikenaga N Yamada M Mase M Narita M 《Avian diseases》2007,51(1):52-57
One-day-old, 2-wk-old, and 4-wk-old call ducks (Anas platyrhyncha var. domestica) inoculated intravenously with the H5N1 highly pathogenic avian influenza virus A/chicken/Yamaguchi/7/2004 isolate (Ck/Yama/7/04) were examined clinically, pathologically, and virologically. Clinically, the birds exhibited mild-to-severe neurologic signs and corneal opacity. All birds in the 1-day-old group and one bird in the 4-wk-old group died within 4 days after the virus inoculation. Histologic changes were characterized by severe nonpurulent encephalitis and necrotic lesions of feather epithelium on day 3 postinoculation (PI) or later. Focal necrosis of myocardial cells, pancreatic acinar cells, skeletal myocytes, and corneal epithelial cells was observed. Viral antigens were detected in association with necrotic changes. Viruses were isolated from all examined organs including the skin with many feathers. Serum antibody against the virus was detected in all surviving birds on day 10 PI by hemagglutination-inhibition tests. These results suggest that Ck/Yama/7/04 has a pathogenicity that causes neurologic sign, nonpurulent encephalitis with mortality, and feather lesions for call ducks. Feather lesions with viral antigens and the virus isolation from the skin suggest that Ck/Yama/ 7/04 has a predilection for feathers in call ducks. 相似文献