共查询到20条相似文献，搜索用时 234 毫秒
1.
High virus titer in feather pulp of chickens infected with subgroup J avian leukosis virus 总被引：1，自引：0，他引：1
Subgroup J avian leukosis viruses (ALVs), which are a recombinant virus between exogenous and endogenous ALVs, can spread by either vertical or horizontal transmission. Exogenous and endogenous ALVs can be detected in feather pulp. In this study, virus titers in feather pulp of chickens infected with subgroup J ALV were compared with those of plasma and cloacal swab. All of the broiler chickens inoculated with subgroup J ALV at 1 day old were positive for virus from feather pulp during the experimental period of between 2 wk and 8 wk of age. Virus titers in feather pulp of some broiler chickens infected with subgroup J ALV were very high, ranging from 10(7) to 10(8) infective units per 0.2 ml. Virus titers in feather pulp were usually the highest among the samples of plasma, cloacal swab, and feather pulp tested. In another experiment in which layer chickens were inoculated with subgroup J ALV at 1 day old, virus was detected in feather pulp from 2 wk until 18 wk of age, and virus persisted longer in feather pulp than in plasma. Almost all of the layer chickens tested were positive for virus by polymerase chain reaction (PCR) with DNA extracted from feather pulp samples at 2, 4, and 10 wk of age, and the PCR from feather pulp was more sensitive than virus isolation from plasma, cloacal swab, and feather pulp. All above results indicate that samples of feather pulp can be useful for virus isolation and PCR to confirm subgroup J ALV infection. 相似文献
2.
3.
Chickens from seven different parental lines of commercial White Leghorn layer flocks from three independent breeders were inoculated with a naturally occurring avian leukosis virus (ALV) containing an ALV-B envelope and an ALV-J long terminal repeat (LTR) termed ALV-B/J. Additional groups of chickens from the same seven parental lines were inoculated with ALV-B. Chickens were tested for ALV viremia and antibody at 0, 4, 8, 16, and 32 wk postinfection. Chickens from all parental lines studied were susceptible to infection with ALV-B with 40%-100% of inoculated chickens positive for ALV at hatch following embryo infection. Similarly, infection of egg layer flocks with the ALV-B/J recombinant virus at 8 days of embryonation induced tolerance to ALV with 86%-100% of the chickens viremic, 40%-75% of the chickens shedding virus, and only 2/125 (2%) of the chickens producing serum-neutralizing antibodies against homologous ALV-B/J recombinant virus at 32 wk postinfection. In contrast, when infected with the ALV-B/J recombinant virus at hatch, 33%-82% of the chickens were viremic, 28%-47% shed virus, and 0%-56% produced serum-neutralizing antibodies against homologous ALV-B/J recombinant virus at 32 wk postinfection. Infection with the ALV-B/J recombinant virus at embryonation and at hatch induced predominately lymphoid leukosis (LL), along with other common ALV neoplasms, including erythroblastosis, osteopetrosis, nephroblastomas, and rhabdosarcomas. No incidence of myeloid leukosis (ML) was observed in any of the commercial White Leghorn egg layer flocks infected with ALV-B/J in the present study. Data suggest that the parental line of commercial layers may influence development of ALV-B/J-induced viremia and antibody, but not tumor type. Differences in type of tumors noted in the present study and those noted in the field case where the ALV-B/J was first isolated may be attributed to differences in the genetics of the commercial layer flock in which ML was first diagnosed and the present commercial layer flocks tested in the present study. 相似文献
4.
A serologic survey has documented probable infection with reticuloendotheliosis (RE) virus in 21.0% of 101 layer flocks, 23.5% of 85 broiler and broiler-breeder flocks, 2.3% of 43 backyard chicken flocks, and 4.8% of 125 turkey production and breeder flocks. However, no infection was detected in 72 grandparent lines of chicken breeding stocks representing meat-type and layer strains. The existence of natural infection was further supported by isolation of RE virus from one experimental chicken flock and two commercial turkey flocks. This study supports earlier but subsequently discounted data by Aulisio and Shelokov that exposure to RE virus occurs commonly among commercial chickens in the United States, as has also been reported in other countries. 相似文献
5.
广西凭祥斗鸡禽白血病病毒检测及分离株env基因分析 总被引：1，自引：0，他引：1
为了解广西凭祥市特有家禽品种斗鸡禽白血病病毒(ALV)的感染情况,采集了该市3个鸡场斗鸡的肛拭子、血清、血浆样品共344份,用禽白血病ELISA检测试剂盒进行检测。结果显示,斗鸡ALV感染情况严重,其中肛拭样品ALV-p27抗原阳性率高达39.13%,血清样品病毒分离阳性率为12.97%,ALV-J和ALV-A/B抗体阳性率分别为22.39%和7.46%;对从2只斗鸡获得的病毒分离株DJ-3-18和DJ-45进行病毒囊膜蛋白基因env的扩增、序列测定及比较分析,结果显示2株病毒的gp85基因与ALV-A亚群参考株之间氨基酸的同源性为88.2%~96.5%,gp37基因与ALV-A亚群参考株之间氨基酸的同源性为91.4%~98.0%,其中与台湾A亚群蛋鸡源分离株TW-3577的亲缘关系最近,而与ALV其他亚群毒株的同源性则较低。结果表明,首次获得的2株斗鸡源ALV分离株属A亚群。 相似文献
6.
为了解AA肉种鸡群中免疫抑制性病毒的存在状况及其对NDV疫苗免疫效果和对商品鸡生长的影响,采用多重PCR、RT-PCR和血清学方法对山东某规模化大型AA父母代肉种鸡场的28日龄、180日龄左右种鸡及其所生产的1日龄、30日龄左右商品鸡进行IBDV、MDV、ALV、REV、CIAV及REOV感染状况的调查,并同时对鸡群NDV免疫后抗体水平进行跟踪监测.结果表明种鸡和商品鸡均存在CIAV的感染,并不同程度地存在CIAV与MDV、IBDV等的共感染;发病鸡群NDV抗体水平明显偏低的原因是由于鸡群感染免疫抑制性病毒所致;种鸡群感染CIAV并垂直传播给商品鸡,间接引起商品鸡发生免疫抑制性病毒的共感染,导致商品鸡群30日龄左右生长受阻、免疫能力降低、疾病爆发. 相似文献
7.
Avian leukosis viruses (ALVs) are common in many poultry flocks and can be detected using an enzyme-linked immunosorbent assay or any other test designed to identify p27, the group-specific antigen located in gag. However, endogenous retroviruses expressing p27 are often present and can be confused with exogenous ALVs. A more specific and informative assay involves targeting the variable envelope glycoprotein gene (gp85) that is the basis for dividing ALVs into their different subgroups. We designed polymerase chain reaction (PCR) primers that would specifically detect and amplify viruses from each of the six ALV subgroups: A, B, C, D, E, and J. Subgroup B and D envelopes are related, and our B-specific primers also amplified subgroup D viruses. We also designed a set of common primers to amplify any ALV subgroup virus. To demonstrate the usefulness of these primers, we obtained from the Center for Veterinary Biologics in Iowa culture supernatant from chicken embryo fibroblasts infected with an ALV that was found to be a contaminant in two commercial Marek's disease vaccines. Using our PCR primers, we demonstrate that the contaminant was a subgroup A ALV. We cloned and sequenced a portion of the envelope gene and confirmed that the ALV was a subgroup A virus. Unlike typical subgroup A viruses, the contaminant ALV grew very slowly in cell culture. We also cloned and sequenced a portion of the long terminal repeat (LTR) from the contaminant virus. The LTR was found to be similar to those LTRs found in endogenous ALVs (subgroup E) and very dissimilar to LTRs normally found in subgroup A viruses. The E-like LTR probably explains why the contaminant grew so poorly in cell culture. 相似文献
8.
9.
Thu WL Wang CH 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(3):325-328
Subgroup J avian leucosis virus (ALV-J) causes great economic losses in the poultry industry. One in 3 grandparent farms was closed due to ALV-J infection in 1998 in Taiwan. The remaining 2 farms were forced to import breeding chicks from different breeding companies afterwards. We report on the ALV-J infection status among these breeders, their progeny and Taiwan native chickens during 2000-2002. The weekly mortality for the male line among the infected breeders was higher than that for the female line. Sixty-three percent (5/8) of the broiler flocks were infected with ALV-J. The surface (SU) portion of the env gene from the ALV-J field isolates was cloned and sequenced. The phylogenetic results show that all of the isolates fell into 2 clusters. Unexpectedly, the isolates from the same breeds fell into different clusters, with a cluster including isolates from different breeding companies. ALV-Js from native chickens crossbred with imported chickens were placed into the same clusters as those from the imported breeds. The high similarities observed in different ALV-J isolates suggest that different ALV-Js were mixed in the pedigree generations in different breeding lines. 相似文献
10.
Avian leukosis virus (ALV) infection in chickens is known to induce increased mortality, tumors, delayed growth, and suboptimal egg production. Countries importing specified pathogen-free eggs, vaccines, and poultry breeding stock require freedom of infection or contamination with ALV in such products among other avian pathogens. Recently, ALV was found as a contaminant in a limited number of commercial poultry vaccines, even after routine quality assurance procedures cleared the vaccines for commercialization. The contaminated vaccines were promptly withdrawn from the market, and no direct detrimental effects were reported in poultry vaccinated with such vaccines. We describe herein the characterization in vitro of the contaminant viruses. All exogenous viruses detected in four vaccine lots belong to subgroup A of ALV based on cell receptor interaction, subgroup-specific polymerase chain reaction (PCR), envelope gene sequencing, and virus neutralization. A combination of thermal treatment and serial dilutions of the contaminated vaccines facilitated detection of contaminating ALVs in cell culture coupled with antigen-capture enzyme-linked immunosorbent assay. Subgroup-specific PCR readily detected ALV-A directly in the contaminated vaccines but not in naive vaccines or cell controls. Our methods are proposed as complementary procedures to the currently required complement fixation for avian leukosis test for detection of ALV in commercial poultry vaccines. 相似文献
11.
In the detection of antibodies against exogenous subgroup A avian leukosis viruses (ALVs) using a representative subgroup A virus, concordance between enzyme-linked immunosorbent assays (ELISAs) and serum neutralizations ranged from 83 to 95%. In ELISAs, subgroup A- and subgroup B-specific neutralizing antisera were equally reactive against ALVs of subgroups A, B, and E. Conversely, little cross-reactivity of high-titered subgroup E antisera was observed against subgroup A viruses. Significant cross-reactivities of spontaneously induced subgroup E-neutralizing antisera were observed when tested against a representative subgroup B ALV. Because some normal chickens spontaneously mount antibodies against infectious endogenous viruses, misleading results may be obtained if subgroup B or E ALVs are the source of target antigens in ELISAs. 相似文献
12.
Immunohistochemical localization of avian leukosis virus subgroup J in tissues from naturally infected chickens. 总被引：4，自引：0，他引：4
The tissue tropism of avian leukosis virus (ALV) subgroup J (ALV-J) was investigated in congenitally infected broiler chickens by an immunohistochemistry technique detecting gp85 viral glycoprotein. All organs examined contained detectable antigen. The most intense staining was in the adrenal gland, heart, kidney, and proventriculus. Intense staining for viral antigen in the heart may explain the ability of ALVs to cause cardiomyopathy. Although recent investigations failed to demonstrate specific viral staining in bone marrow from infected chickens, we were able to show moderate staining in myelocytic precursor cells in bone marrow. This finding agrees with previous work showing cell cultures of bone marrow are susceptible to ALV-J infection and the tendency of subgroup J to predominantly induce myeloid rather than lymphoid neoplasms. 相似文献
13.
Ornithobacterium rhinotracheale is a gram negative bacterial pathogen causing respiratory tract infections in poultry. Tracheal, lung and serum samples were
obtained from 21 broiler flocks of 8 farms from a slaughterhouse located in south-eastern of Iran. Among 630 tracheal and
lung samples from samples resulting from 315 chickens, 11 (3.5%) ORT isolates were identified using biochemical tests. The
isolates originated from 9 (42.9%) flocks out of 4 farms. All of the isolates were recovered from tracheal swabs and showed
an API 20NE identification biocode 0-2-2-0-0-0-4. Of the 420 serum samples examined by ELISA, 134 (31.9%) sera from 17 (81.0%)
flocks were positive for ORT antibodies. These results indicate that ORT is present in most broiler flocks with respiratory
disorders in southeast Iran. 相似文献
14.
15.
Owoade AA Oluwayelu DO Fagbohun OA Ammerlaan W Mulders MN Muller CP 《Avian diseases》2004,48(1):202-205
Sera samples from seven poultry farms in southwest Nigeria consisting of 7 broiler, 10 pullet, 1 layer, 1 cockerel, and 1 broiler breeder flocks were tested for the presence of chicken infectious anemia virus (CIAV) antibodies using a commercial enzyme-linked immunosorbent assay kit. Eleven of the 20 flocks (55%) and six out of seven (86%) farms were positive for CIAV antibodies. The seroprevalence largely depended on the age of the flocks. Seroprevalence was higher within the older pullet and layer flocks (83%-100%) than in the younger broiler flocks (0%-83%). In essence, all flocks older than 6 to 8 wk became infected. This is the first report of serologic evidence of CIAV in Subsaharan Africa. Since Southwest Nigeria is the main port of entry of imported chicken and the hub of major poultry breeders, the disease can probably be found throughout the country and beyond. Further studies are necessary to assess economic losses due to CIAV and the cost benefit of countermeasures. 相似文献
16.
Since a new envelope subgroup (J) of the avian leukosis-sarcomatosis-complex was isolated for the first time from broiler breeders in the United Kingdom in 1989 and was characterized and associated with myeloid leukosis (syn. myelocytomatosis) the emergence of this subgroup was reported from all over the world. Thus the first known case of subgroup J avian leukosis in Switzerland in four imported broiler breeder flocks will be described. A total of 53 broiler breeder birds from four flocks showing reduced performance and increased mortality were submitted for postmortem examination. Approximately 20 blood samples from each flock were monitored serologically for antibodies against avian leukosis virus subgroup J (ALV-J). On necropsy myeloid leukosis (ML) was diagnosed in all four flocks. Furthermore the blood samples of three flocks showed significant ELISA-titres for ALV-J. 相似文献
17.
Allymehr M 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2006,53(1):40-42
Ornithobacterium rhinotracheale is a pleomorphic Gram-negative rod shaped bacterium of the rRNA superfamily V that is associated with respiratory disease in poultry. This study was conducted to determine the seroprevalence of O. rhinotracheale infection in broiler and broiler breeder chickens in West Azerbaijan (Urmia lake region) by using a commercial enzyme-linked immunosorbent assay. In this study, 463 serum samples were obtained from 50 broiler flocks and 472 blood sera from 42 broiler breeder flocks. Results showed that 41 broiler flocks (82%) and 39 broiler breeder flocks (92.8%) were positive. Ornithobacterium rhinotracheale antibodies were detected in 205 (44.2%) of the 463 broiler serum samples. Of the 472 blood sera examined from broiler breeder, 340 (72%) were positive. The results of this study indicated that the prevalence of O. rhinotracheale antibodies is high in the broiler and broiler breeder flocks in West Azerbaijan. 相似文献
18.
Engström BE 《Acta veterinaria Scandinavica》1999,40(2):97-107
A serological survey for antibody to Chicken Anaemia Virus (CAV) was performed on broiler breeders as well as layer breeding birds in Sweden at the end of their rearing period. Grandparents (GP) of both types leaving quarantine were in 21 out of 26 cases free from antibody to CAV, but often became infected soon thereafter. A total of 10 outbreaks of blue wing disease (BWD) in 3 series were recorded in the broiler and layer parent generation, all of which were progeny of 3 late seroconverting GP-flocks. All but one of 22 layer parent flocks had been infected and had seroconverted during the rearing period. Subsequently BWD was not recorded from commercial layers. Broiler parent flocks were more protected from CAV infection during rearing. Eighteen out of 94 broiler parent flocks had not developed antibody to CAV before coming into lay. Outbreaks of BWD were reported in progeny flocks from all these broiler breeders, with the exception of those that had been vaccinated. Good hygienic routines along with isolation of the birds delayed the seroconversion to CAV in broiler breeders and vaccination of these breeders protected their progeny from outbreaks of BWD. Broiler flocks in houses where BWD had occurred recently had always antibodies to CAV at slaughter. It was possible to eradicate the infection from the house and prevent the infection between flocks by proper cleaning and disinfection of the broiler houses. 相似文献
19.
Eight poultry farms in Nigeria, including chickens from nine breeder, 14 broiler, 28 pullet, 11 layer, and three cockerel flocks, were tested for antibody seroprevalence to the following poultry viruses of potential economic importance: infectious bronchitis virus (IBV), avian reovirus, avian pneumovirus (APV), infectious laryngotracheitis virus (ILTV), avian influenza virus (AIV), and avian leukosis virus (ALV). Serum samples were collected between 1999 and 2004 and were tested for antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. Seroprevalence was very high for IBV (84%); intermediate for reovirus (41%), APV (40%), and ILTV (20%); and very low for ALV (<5%) antibodies. By commercial ELISA, the seroprevalence of antibodies against AIV was, in some flocks, up to 63%. However, more specific assays did not confirm AIV antibodies, indicating that all flocks tested were free of avian influenza antibodies. Birds seemed to be first infected by IBV (at about 7 wk of age), then by reovirus at 12 wk, before they became infected by APV (week 25) and ILTV (week 30). This is the first report of serological evidence of the above viruses in West Africa. Further studies are necessary to assess economic losses due to these avian viruses and the costs and benefits of countermeasures. 相似文献
20.
禽淋巴细胞性白血病的诊断与病毒亚群鉴定 总被引：3，自引：0，他引：3
采用病理组织学方法对某商品蛋鸡场送检的发病鸡进行实验室诊断,在肿胀的肝、脾、肾和法氏囊组织切片中观察到成淋巴细胞增生病变。使用禽白血病A、B亚群抗体检测试剂盒对血清样本进行间接ELISA试验,抗体阳性率达到44.4%(12/27)。采集12只病死鸡的肝脏材料提取DNA样本,11份样本中扩增出ALV-A亚群特异性的病原核酸(691bp),检出率达到91.6%(11/12)。将扩增的目的基因克隆与测序,截取gp85基因片段可变区序列与ALV-A、B、C、D和E亚群参考毒株的相应序列进行比较,同源性分别达到89.0-89.6%、67.1-67.7%、69.1-70.1%、69.1-69.5%和70.9-72.0%。结果证实本次疫病是由ALV-A亚群病毒引起的淋巴细胞性白血病。 相似文献