Avian clinical pathology.

Much of the information previously available concerning avian clinical pathology was drawn from data from domestic avian species, in particular, poultry. Clinical pathology of nondomestic avian species such as psittacines, however, has come a long way toward establishing normal reference values for caged birds. As a result, it is important for the avian clinician to learn which clinical tests can be used to detect and evaluate a single disease or disease processes by learning what information is gained from hematologic, biochemical, or cytologic samples acquired during a patient's clinical examination.     

Serotyping avian adenoviruses by a microneutralization procedure.

A microneutralization procedure, using chicken kidney cell monolayers as an indicator system, was developed and applied to the serotyping of isolates characterized as avian adenoviruses. The method was determined to be reproducible, since coefficients of variation were low for 12 replicate titrations of homologous reagents of 9 prototype avian adenoviruses. Prototype reagents were specific according to results of reciprocal end point-neutralization tests and comparison of antigenic relatedness, using results obtained by previous researchers. Forty-two avian adenovirus isolates were classified into 6 serotypes by one-side end point-neutralization tests against antiserums made to 9 prototype avian adenoviruses. An additional 20 isolates were antigenically related to prototype viruses, but they could not be specifically types with the typing criteria. Different serotypes were isolated from birds having similar clinical diagnostic signs and lesions of disease.     

蚯蚓纤溶酶的分离纯化及临床作用研究进展

蚯蚓纤溶酶是从蚯蚓中分离的一种丝氨酸蛋白水解酶,有抗凝溶血栓、抗癌抗肿瘤、抗炎、神经修复等作用,在临床上是预防和治疗血栓疾病的有效药物。本文对蚯蚓纤溶酶的分离纯化与药理作用加以概述,为临床蚯蚓溶栓药物的研究提供依据。     

Microarrays in veterinary diagnostics

Microarrays have numerous applications in the clinical setting, and these uses are not confined to the study of common human diseases. Indeed, the high-throughput technology affects clinical diagnostics in a variety of contexts, and this is reflected in the increasing use of microarray-based tools in the development of diagnostic and prognostic tests and in the identification of novel therapeutic targets. While much of the value of microarray-based experimentation has been derived from the study of human disease, there is equivalent potential for its role in veterinary medicine. Even though the resources devoted to the study of animal molecular diagnostics may be less than those available for human research, there is nonetheless a growing appreciation of the value of genome-wide information as it applies to animal disease. Therefore, this review focuses on the basics of microarray experimentation, and how this technology lends itself to a variety of diagnostic approaches in veterinary medicine.     

Testing and management of a specific pathogen free chicken flock with special reference to avian leukosis virus infections.

A specific pathogen free (SPF) chicken flock was reared in isolation under laboratory conditions during five years and continuously tested for presence of specified avian pathogens. The potential occurrence of avian leukosis virus (ALV) was most thoroughly examined. The RIF and neutralization tests were unequivocally negative. Radioimmunoassay was used for detecting the presence of the major protein (gs-a) of the group-specific antigen of avian onoorna viruses. This test seemed to he well suited for checking ALV infections in chicken flocks whereas the COFAL (complement fixation avian leukosis) test was considered unreliable for this purpose. Yolk and serum from SPF chickens were negative for anti-gs-a antibodies measured by the radioimmunoassay; immunized or naturally infected birds showed anti-gs-a amounts correlating with the neutralizing titre. Besides, the flock was regularly tested for presence of seven other contagious avian pathogens. There was no evidence of infection.SPF chicken flock; avian leukosis; laboratory diagnosis of avian leukosis virus infections.     

Avian paramyxovirus type 1 infection in pigeons: recent changes in clinical observations

Since its first appearance in 1984, avian paramyxovirus type 1 has remained an enzootic disease in racing pigeons on Long Island, New York. The clinical presentation of the disease in the autumn of 1987 suggests a decrease in the severity and incidence of neurological signs, with the chief complaint being watery droppings accompanied by poor racing performance. Diagnosis is based upon serology, using hemagglutination-inhibition tests with Newcastle disease or paramyxovirus type 1 virus.     

3种禽类呼肠孤病毒血清学相关性及致细胞病变差异分析

本研究旨在研究3种不同疾病型禽类呼肠孤病毒间的抗原性关系及病毒的培养特性。作者通过血清中和试验测定了禽呼肠孤病毒(ARV S1133株)、番鸭呼肠孤病毒(MDRV 9710株)、新型鸭呼肠孤病毒(NDRV NP01株)3种禽类呼肠孤病毒的血清学相关性,统计抗原相关性R值;并应用部分禽胚原代细胞及哺乳动物传代细胞对这3种病毒的培养特性进行了初步研究。结果表明,3种病毒株之间的R值很小,抗原相关性较低;三者具有广泛的细胞亲嗜性,能在多种细胞中增殖,并产生细胞病变,但病毒致细胞病变特征有所差异,ARV和NDRV均以巨融合为主,而MDRV则以细胞圆缩坏死为主。上述结果表明导致禽类不同疾病的ARV、MDRV和NDRV三者之间的抗原相关性较低,病毒的细胞培养特性也不同,细胞病变类型的差别提供了一种初步鉴别禽类呼肠孤病毒的方法。     

Serologic surveillance of swine H1 and H3 and avian H5 and H9 influenza A virus infections in swine population in Korea

Influenza A is a respiratory disease common in the swine industry. Three subtypes, H1N1, H1N2 and H3N2 influenza A viruses, are currently co-circulating in swine populations in Korea. An outbreak of the highly pathogenic avian influenza H5N1 virus occurred in domestic bird farms in Korea during the winter season of 2003. Pigs can serve as hosts for avian influenza viruses, enabling passage of the virus to other mammals and recombination of mammalian and avian influenza viruses, which are more readily transmissible to humans. This study reports the current seroprevalence of swine H1 and H3 influenza in swine populations in Korea by hemagglutination inhibition (HI) assay. We also investigated whether avian H5 and H9 influenza transmission occurred in pigs from Korea using both the HI and neutralization (NT) tests. 51.2% (380/742) of serum samples tested were positive against the swine H1 virus and 43.7% (324/742) were positive against the swine H3 virus by HI assay. The incidence of seropositivity against both the swine H1 virus and the swine H3 virus was 25.3% (188/742). On the other hand, none of the samples tested showed seropositivity against either the avian H5 virus or the avian H9 virus by the HI and NT tests. Therefore, we report the high current seroprevalence and co-infectivity of swine H1 and H3 influenza viruses in swine populations and the lack of seroepidemiological evidence of avian H5 and H9 influenza transmission to Korean pigs.     

Characterization of the neurotoxin produced by isolates associated with avian botulism

Several varieties of birds are affected by type C botulism. We conducted neutralization tests of culture supernatants of isolates from cases of avian botulism. Whereas the toxin produced by isolates derived from mammalian botulism was neutralized only with type C antitoxin, the toxins of all isolates related to avian botulism were neutralized with both type C and D antitoxins. An analysis of nucleotide sequences with several strains revealed that the neurotoxin gene in the isolates from avian botulism comprises two thirds of the type C neurotoxin gene and one third of the type D neurotoxin gene. This indicates that the neurotoxin of avian isolates is a mosaic of type C and D neurotoxins. We prepared three sets of primers to differentiate the gene for the mosaic form from the conserved genes of type C and D neurotoxins. The results of polymerase chain reaction with these primers indicated that all avian botulism-related isolates and specimens possess the gene for the mosaic form of the neurotoxin. The toxins purified from avian and mammalian isolates exhibited the same degree of lethality in mice, but the former showed greater toxicity to chickens than the latter. These results indicate that the mosaic neurotoxin is probably a pathogenic agent causing some forms of avian botulism.     

武汉市新洲区2021年高致病性禽流感和新城疫免疫抗体监测数据浅析

高致病性禽流感（highly pathogenic avian influenza, HPAI）和新城疫（newcastle disease, ND）等烈性传染病对养禽业危害严重,是养禽业需重点防控的疾病,其中HPAI是国家规定的强制免疫疫病。武汉市新洲区为家禽养殖大区,有规模禽场350余家,养殖规模近1140万只。为了解2021年度武汉市新洲区规模养殖场高致病性禽流感和新城疫免疫抗体合格率,武汉市新洲区农业技术推广服务中心连续12个月对辖区内规模鸡场进行蛋样抽检,运用血凝和血凝抑制试验,分别检测了高致病性禽流感H5亚型、H7亚型和新城疫的免疫抗体。结果显示,高致病性禽流感H5亚型、H7亚型和新城疫的整体免疫抗体合格率分别为94.1%、96.4%和88.9%,均达到了农业农村部规定的免疫抗体合格率不低于70.0%的标准。     

禽黄病毒套式RT-PCR检测方法的建立及应用

禽黄病毒病是新发的一种疫病,可引起鸭、鹅和鸡等家禽产蛋和采食量下降及死亡。本研究旨在建立一种快速诊断方法用于临床诊断及流行病学调查。根据GenBank发表的鹅黄病毒JS804株全基因序列,应用Primer Premier 5.0软件设计了2对特异性引物,建立了禽黄病毒套式RT-PCR检测方法。结果:该套式RT-PCR方法具有特异性强、敏感性高的特点,最低病毒检测量为101.89TCID50/0.1 mL,比普通RT-PCR方法敏感性高1 000倍。应用该方法对江苏地区疑似禽黄病毒病的70份鹅病料、4份鸭病料、12份鸡病料进行检测,总阳性率为58.14%,而用普通RT-PCR方法检测的阳性率仅为17.44%。结果表明,禽黄病毒套式RT-PCR检测方法具有快速、特异、敏感的特点,可用于禽黄病毒感染的临床诊断和流行病学调查。     

禽流感病毒非结构蛋白NS1的分子生物学特性与功能

禽流感严重威胁着世界养禽业及人类健康.随着对流感病毒研究的逐渐深入,人们已经从对流感病毒结构蛋白的研究转移到对非结构蛋白即NS1蛋白的研究上来.研究发现流感病毒的NS1蛋白与流感病毒所诱导的细胞凋亡之间存在一定的联系,其对凋亡的调节作用与流感病毒感染的细胞是否产生干扰素及其所感染的细胞系直接相关.NS1蛋白能够抑制病毒感染细胞干扰素的产生,在流感病毒颉颃干扰素的抗病毒效应中发挥了重要的作用.随着疫苗的广泛使用,无法区分野毒感染和疫苗免疫的禽群,干扰了禽流感的诊断,掩盖了禽流感的流行,增加了禽流感的预防难度.NS1蛋白作为流感病毒的非结构蛋白,具有高度的保守性,在临床应用中作为鉴别诊断免疫禽和自然感染禽的检测抗原具有广阔前景.     

Comparison of DNA-spot hybridization, cell culture and direct immunofluorescence staining for the diagnosis of avian chlamydiae

DNA-spot hybridization, cell culture and direct immunofluorescence staining were compared for the detection of avian Chlamydia psittaci strains in cell culture dilutions and in routine samples submitted for diagnosis. With dilutions of infected cell culture material, growth in BGM cells was by far the most sensitive technique, detecting 0.01 infected cells (20 elementary bodies) ml-1. DNA-spot hybridization and direct immunofluorescence staining were of approximately equal sensitivity, both detecting 16 infected cells (3.2 x 10(4) elementary bodies) per ml-1. When 27 avian liver and spleen samples were assayed, all 3 tests performed similarly (13 positive and 12 negative by all 3 tests). This suggests that in most avian samples presented for diagnosis, sufficient numbers of chlamydiae are present to allow any of the test to the be used. Thus, the direct immunofluorescence staining method is currently the test of choice for routine diagnosis since it is available in kit form, is relatively simple and quick to perform, and like DNA-spot hybridization, detects non-viable as well as viable organisms. However, if low levels of chlamydiae are to be effectively detected, such as in carrier birds or birds with recently acquired infections, then cell culture should be used.     

Avian Atherosclerosis: Parrots and Beyond

Atherosclerotic lesions are prevalent in companion psittacine species. Parrots account for much of the veterinary scientific information on avian atherosclerosis, but the lesions have been described in virtually all avian orders. This review presents a synthesis of the epidemiologic, clinical, diagnostic, and therapeutic information known in psittaciformes, at this time, which may help in the veterinary management of atherosclerotic diseases. The article further expands on nondomestic avian species for which information is restricted to pathologic and prevalence studies. A thorough knowledge of atherosclerosis is of the upmost importance for avian clinicians as the disease is common, affects most species of birds, and seems to be associated with captive lifestyles characterized by decreased activity and nonnative diets. Therefore, avian veterinarians are expected to be largely exposed to this chronic medical condition through patient presentation and should be prepared to properly manage this disease.     

Development of a Duplex PCR Assay for Detection of Avian Influenza Virus and Chicken Parvovirus

In order to establish a method to simultaneously detect avian influenza virus (AIV) and chicken parvovirus (ChPV),two pairs of specific primers were designed according to the sequences of AIV M gene and ChPV NS gene in GenBank. The duplex PCR assay was established by optimizing the reaction conditions.The tests showed that this method had high specificity, could simultaneously detect AIV and ChPV and no specific band was amplified for other subtypes avian pathogenic virus. The sensitivity result showed that the lower detection limit of this method was 100 fg. The results of 159 clinical samples were consistent with the sequencing results of PCR positive product. The double PCR methods for detection of AIV and ChPV established in this study had the characteristics of good specificity and high sensitivity, which was of great significance to the prevention control of AIV and ChPV.     

广西禽巴氏杆菌的分离及其特性的测定

1990～1997年间,本研究室从广西不同地区鸡场死于禽巴氏杆病菌的家禽中分离并鉴定13株禽巴氏杆菌（包括鸡源的12株,鸭源的1株）。菌株经中国兽药监察所进行Carter定型,结果为荚膜A型。13个分离菌株都100％致死本地三黄鸡。     

病毒接种后死亡鸡胚绿脓杆菌的分离鉴定及药敏试验

鸡胚的种毒接种是禽流感疫苗生产的一个必要环节.从接种病毒后的死亡鸡胚中分离到一株细菌,通过细菌生长特性观察、显微镜检查、生化鉴定以及16 S rDNA PCR鉴定,结果表明为绿脓杆菌.该细菌对青霉素钾、硫酸链霉素、硫酸丁胺卡那耐受,对盐酸环丙沙星敏感.这是在国内首次报道由于接种引起绿脓杆菌污染间接致死大量鸡胚.     

Respiratory disease (rhinotracheitis) in turkeys in Brittany, France, 1981-1982. I. Field observations and serology

During the summer of 1981, a respiratory disease epidemic occurred in turkeys in Brittany, France. Since this initial epizootic, which lasted through fall, epizootic waves similar to the initial one have occurred at approximately 6-month intervals, with smaller peaks at 2-month intervals. The epidemiology, clinical signs, and postmortem findings were highly suggestive of an epizootic of chlamydiosis. Serological tests for chlamydia, paramyxoviruses, avian influenza, adenovirus 127, mycoplasma, and Alcaligenes faecalis were conducted. The chlamydia tests were the only ones consistently positive.