水貂犬瘟热动物模型的建立

目的建立水貂犬瘟热动物模型,并利用水貂犬瘟热模型评价不同犬瘟热强毒株的毒力,为水貂犬瘟热病毒疫苗的研究奠定基础。方法从猴、藏獒、犬的病料中分离犬瘟热病毒,测定犬瘟热病毒的毒力,并进行传代培养。利用犬的犬瘟热动物模型筛选稳定的犬瘟热强毒株,进行水貂犬瘟热动物模型的建立及其毒力评估。结果筛选出了稳定的犬瘟热强毒株并进行了家犬动物实验,同时表现出了强烈的临床症状,并利用不同的代次毒进行了犬瘟热动物模型的建立。结论成功建立了犬瘟热动物模型并对不同来源的犬瘟热病毒毒力进行了评估。     

Morbilliviruses use signaling lymphocyte activation molecules (CD150) as cellular receptors

Morbilliviruses comprise measles virus, canine distemper virus, rinderpest virus, and several other viruses that cause devastating human and animal diseases accompanied by severe immunosuppression and lymphopenia. Recently, we have shown that human signaling lymphocyte activation molecule (SLAM) is a cellular receptor for measles virus. In this study, we examined whether canine distemper and rinderpest viruses also use canine and bovine SLAMs, respectively, as cellular receptors. The Onderstepoort vaccine strain and two B95a (marmoset B cell line)-isolated strains of canine distemper virus caused extensive cytopathic effects in normally resistant CHO (Chinese hamster ovary) cells after expression of canine SLAM. The Ako vaccine strain of rinderpest virus produced strong cytopathic effects in bovine SLAM-expressing CHO cells. The data on entry with vesicular stomatitis virus pseudotypes bearing measles, canine distemper, or rinderpest virus envelope proteins were consistent with development of cytopathic effects in SLAM-expressing CHO cell clones after infection with the respective viruses, confirming that SLAM acts at the virus entry step (as a cellular receptor). Furthermore, most measles, canine distemper, and rinderpest virus strains examined could any use of the human, canine, and bovine SLAMs to infect cells. Our findings suggest that the use of SLAM as a cellular receptor may be a property common to most, if not all, morbilliviruses and explain the lymphotropism and immunosuppressive nature of morbilliviruses.     

Diseases and parasites of red foxes, gray foxes, and coyotes from commercial sources selling to fox-chasing enclosures.

Fifty-six red foxes (Vulpes vulpes), 18 gray foxes (Urocyon cinereoargenteus), and 13 coyotes (Canis latrans) obtained by the South Carolina Wildlife and Marine Resources Department during an investigation of suspected illegal wildlife translocation were examined for diseases and parasites. Red foxes and coyotes were confiscated from an animal dealer based in Ohio (USA), and gray foxes were purchased from an animal dealer in Indiana (USA). Emphasis was placed on detection of pathogens representing potential health risks to native wildlife, domestic animals, or humans. All animals were negative for rabies; however, 15 gray foxes were incubating canine distemper at necropsy. Serologic tests disclosed antibodies to canine parvovirus, canine distemper virus, canine adenovirus, canine coronavirus, canine herpesvirus, and canine parainfluenza virus in one or more host species. Twenty-three species of parasites (two protozoans, three trematodes, four cestodes, eleven nematodes, and three arthropods) were found, including species with substantial pathogenic capabilities. Echinococcus multilocularis, a recognized human pathogen not enzootic in the southeastern United States, was found in red foxes. Based on this information, we conclude that the increasingly common practice of wild canid translocation for stocking fox-chasing enclosures poses potential health risks to indigenous wildlife, domestic animals, and humans and, therefore, is biologically hazardous.     

犬瘟热病毒RT-LAMP检测方法的建立和初步应用

目的利用环介导等温扩增（LAMP）技术建立一种检测犬瘟热病毒感染的新方法。方法根据GenBank中NP基因序列,设计4条LAMP特异性引物,对反应条件、特异性、可视化效果和应用效果进行研究。结果在60℃等温的条件下、1 h内可完成RT-LAMP扩增过程;特异性和可视效果良好;对63份临床标本进行检测,阳性检出率为71.4%（45/63）,检出率高于RT-PCR的63.5%（40/63）。结论建立的RT-LAMP检测方法,显示了较高的特异性和敏感性,而且兼具高效、快捷、可视化的优势,为临床检测犬瘟热病毒感染提供了一种快速简便的新途径。     

Diseases, parasites and survival of coyotes in south-central Georgia.

Serologic testing, radio-telemetry and post-mortem diagnostic evaluations were used to investigate survival and causes of mortality among 17 coyotes (Canis latrans) in south-central Georgia (USA). Prevalence of canine heartworm (Dirofilaria immitis) microfilariae was lower (P = 0.057) among fall-captured (22%) than among winter-captured (75%) coyotes. Prevalence of heartworm was higher among adults than juveniles in the fall, but no significant difference was detected between animals captured in winter. Antibodies were found against canine parvovirus (65%), canine parainfluenza virus (59%), infectious canine hepatitis virus (41%), and Toxoplasma gondii (18%). Antibodies were not found to Brucella canis, canine coronavirus, five serovars of Leptospira interrogans, or canine distemper virus. Seroprevalence of canine parvovirus was lower (P = 0.009) among fall-captured animals (33%) than winter-captured animals (100%). The Kaplan-Meier estimate of annual survival was 0.500 for all animals. Juvenile survival did not differ (P = 0.79) from adult survival, but male survival (S = 0.217) was lower (P = 0.11) than female survival (S = 0.804). Two of nine (22%) mortalities were human-caused, one was due to concurrent canine parvovirus and canine distemper virus infections, one animal died of trauma, two were considered natural mortalities of unknown cause, and no cause of death could be determined for the remaining three animals. Natural mortality may be significant for coyotes in south-central Georgia, although there was no apparent link between exposure to pathogens and the animals' subsequent fate in our small sample.     

Continuous-Flow Ultracentrifugation of Canine Distemper Virus and Infectious Canine Hepatitis Virus

The use of a Spinco L-4 zonal centrifuge with the B-XVI continuous-flow rotor for the purification of canine distemper and infectious canine hepatitis viruses is described. Up to 68 liters of virus was processed at one time. Infectious canine hepatitis virus was found to band at 39% sucrose and canine distemper virus banded between 32 and 48% sucrose. The virus was concentrated 10-fold, and the purity of the virus, as measured by protein concentration, was increased by 99%.     

犬瘟热与野生动物

犬瘟热是一种犬瘟热病毒引起的多种动物共患传染病,在世界范围内的家犬和野生动物中多次爆发。犬瘟热的跨种间传播对多种野生动物如东北虎、非洲狮、雪豹、大熊猫等野生动物的种群安全造成严重威胁,并且感染的宿主范围仍在扩大。近年来的研究表明,犬瘟热病毒的不断变异和野生动物栖息地内流浪犬只的增多使我国野生动物尤其是野外种群正在面临犬瘟热的严重威胁。为了更好地应对犬瘟热对野生动物的危害,本文综述了犬瘟热的病原特征和在野生动物中的流行病学、致病机制、诊断与治疗以及疫苗免疫方面的研究进展,在此基础上提出了针对传染源、传播途径、易感动物三方面的控制措施来减少野生动物犬瘟热的传播风险。目前,由于国内自然保护区科研技术力量欠缺以及防控意识薄弱,对于野生动物犬瘟热的监测处于空白状态,这无疑加大了野生动物犬瘟热的防控难度。因此,为了保障我国野生动物种群安全,我们需要加强在野生动物犬瘟热监测与流行病学方面的研究工作,建立有效的监测防控体系将犬瘟热阻挡在野生动物种群之外。     

Canine distemper in black-footed ferrets (Mustela nigripes) from Wyoming

In September and October 1985, six black-footed ferrets (Mustela nigripes) were captured from the only known population, located near Meeteetse, Wyoming for captive propagation. Two days following capture an adult male showed signs of canine distemper and an adult female displayed similar signs 7 days postcapture; these infections were undoubtedly acquired prior to capture. Subsequently the four remaining captive black-footed ferrets also developed canine distemper and all eventually died. Clinical signs included severe pruritus, hyperkeratosis and progressive loss of body condition. A few animals had intermittent diarrhea and respiratory disease. Intranuclear and intracytoplasmic inclusion bodies were numerous in epithelial tissues and two black-footed ferrets had a mild to moderate meningoencephalitis. Canine distemper virus was isolated from four animals and paramyxovirus nucleocapsids were observed by electron microscopy of feces from all affected black-footed ferrets. Antibodies to canine distemper virus were not detected in sera of sick black-footed ferrets. Antibodies to canine distemper virus were found in sera of badgers (Taxidea taxus) and coyotes (Canis latrans) collected in the Meeteetse area in 1986. Most free-ranging black-footed ferrets in the colony apparently died of canine distemper during the summer and fall of 1985. An attempt was made to capture all surviving animals in the affected area in order to abort the epizootic and provide black-footed ferrets for captive propagation.     

Morbillivirus infection in a wild siberian tiger in the Russian Far East

We report the first documented case of morbillivirus infection in a wild, free-ranging Siberian tiger (Panthera tigris altaica). The tigress entered a small village in the Russian Far East in an ambulatory but stuporous state with no apparent recognition or fear of humans. Her condition progressed rapidly with neurological signs, anorexia, and ultimately death. Histologic lesions included vacuolated to malacic white matter in the brain stem, cerebellum, and thalamus, with associated lymphocytic meningoencephalitis. Large, intranuclear, eosinophilic inclusions were within regional astrocytes, and the brain lesions were immunohistochemically positive when stained for canine distemper viral antigen. Hematologic and blood chemistry results were consistent with overwhelming systemic infection and starvation. The animal also was antibody-positive for canine distemper virus, feline panleukopenia, and feline coronavirus.     

Rabies and canine distemper in an arctic fox population in Alaska

Two oil field workers were attacked by a rabid arctic fox (Alopex lagopus) in the Prudhoe Bay oil field (Alaska, USA) prompting officials to reduce the local fox population. Ninety-nine foxes were killed during winter 1994. We tested foxes for prevalence of rabies and canine distemper. Exposure to rabies was detected in five of 99 foxes. Of the five, only one fox had rabies virus in neural tissue as determined by the direct fluorescent antibody test. The other four foxes had been exposed to rabies, but had apparently produced antibodies and did not have an active infection. No evidence of canine distemper was detected as determined by the absence of distemper antibodies in serum and distemper virus in neural tissue.     

小熊猫犬瘟热病及病原研究

1999年2月和1999年7月,重庆动物园和雅安碧峰峡生态动物园喂养的小熊猫分别大面积爆发和流行犬瘟热病,重庆动物园小熊猫死亡11只,死亡率达100％,碧峰峡动物园小熊猫死亡4只,死亡率为25％,两地发病猫所表现的临床症状和病理解剖变化不完全一致,但均有血便、呼吸急促、不食、精神差、肺出血充血等类似症状。从碧峰峡动物园患病小熊猫分离出的犬瘟热毒株（cdv2株）对VEFO细胞适应性比重庆动物园分离的毒株(cdv1株）强,其TCID50达10^－6。两地分离的毒株均能同抗犬瘟热阳性高免血清反应。此外,用抗犬瘟热高免血清治疗,成功地挽救了12只病重的小熊猫。     

Distemper-like disease and encephalitozoonosis in wild dogs (Lycaon pictus)

Clinical signs of a fatal disease resembling those of canine distemper were observed in two groups of captive wild dog (Lycaon pictus) pups 13 days after vaccination with a commercially available combination vaccine for dogs which contained a live attenuated strain of canine distemper virus. Histopathological examination of tissues revealed the presence of intranuclear inclusion bodies in neurons and lesions resembling canine distemper as well as colonies of an Encephalitozoon sp. in the central nervous system and kidneys. Lesions were observed in both organs which resembled those described in other species infected with Encephalitozoon cuniculi.     

Encephalitis induced by a canine distemper virus in squirrel monkeys

Intracerebral inoculation with canine distemper virus (CDV) caused acute neurological signs of viral encephalitis in squirrel monkeys. Electroencephalogram revealed an abnormal sharp wave and seizure discharges resembling those of epilepsy. There was parenchymal inflammation, perivascular cuffs, neuronal degeneration, and glial reactions. Virus antigen was detected immunohistologically in the neurons and ependymal cells. Thus, CDV infection in squirrel monkeys provides an animal model for viral encephalitis and epilepsy.     

Magnetic protein microbead-aided indirect fluoroimmunoassay for the determination of canine virus specific antibodies

Rabies, canine distemper, and canine parvovirus are common contagious viral diseases of dogs and many other carnivores, and pose a severe threat to the population dynamics of wild carnivores, as well as endangering carnivore conservation. However, clinical diagnosis of these diseases, especially canine distemper and canine parvovirus, is difficult because of the broad spectrum of symptoms that may be confused with other respiratory and enteric diseases of dogs. The most frequently used and proven techniques for diagnosing viral diseases include the conventional enzyme-linked immunosorbent assay (ELISA), rapid fluorescent focus inhibition test (RFFIT), mouse neutralisation test (MNT), and fluorescent antibody virus neutralization (FAVN) test. However, these methods still have some inherent limitations. In this study, a magnetic protein microbead-aided indirect fluoroimmunoassay was developed to detect canine virus specific antibodies, human rabies immunoglobulin, CDV McAbs, and CPV McAbs. In this assay, an avidin-biotin system was employed to combine magnetic microbeads and virus antigens (rabies virus, canine distemper virus, and canine parvovirus). Quantification of the targeted virus antibodies was analyzed through indirect fluoroimmunoassay using the specific antigen-antibody reaction, as well as their corresponding FITC-labeled detection antibodies (mouse anti-human IgG/FITC conjugate or rabbit anti-dog IgG/FITC conjugate). The results indicated that the fluorescence intensity increased when a higher concentration of the targeted analyte was used, but the control had almost no fluorescence, much like the conventional ELISA. For human rabies immunoglobulin, CDV McAbs, and CPV McAbs, the minimum detectable concentrations were 0.2 IU/mL, 0.3 ng/mL, and 0.5 ng/mL, respectively. All of these results indicate that this assay can be employed to determine the presence of canine virus specific antibodies. In addition, the method devised here can be utilized as a general protocol in other bacterial and viral marker analysis.     

Inactivation of laboratory animal RNA-viruses by physicochemical treatment

Eight commonly used chemical disinfectants and physical treatments (UV irradiation and heating) were applied to both enveloped RNA viruses (Sendai virus, canine distemper virus) and unenveloped RNA viruses (Theiler's murine encephalomyelitis virus, reo virus type 3) to inactivate infectious virus particles. According to the results, alcohols (70% ethanol, 50% isopropanol), formaldehyde (2% formalin), halogen compounds (52ppm iodophor, 100ppm sodium hypochlorite), quaternary ammonium chloride (0.05% benzalkonium chloride) and 1% saponated cresol showed virucidal effects giving more than 99.95% reduction in the infectivity of virus samples of Sendai virus and canine distemper after 10 minutes exposure. There was no significant difference in the effects on the two enveloped RNA viruses. The susceptibility of unenveloped RNA viruses to chemical disinfectants and physical treatments differed greatly from the enveloped viruses. The two unenveloped viruses showed distinct resistance to 50% isopropanol, 2% formalin, 1% saponated cresol and to physical treatments (heating at 45, 56, 60 degrees C, and UV irradiation). These results indicate that using physicochemical methods to inactivate RNA viruses in laboratory animal facilities should be considered in accordance with the characteristics of the target virus. For practical purposes in disinfecting enveloped RNA viruses, 70% ethanol, 0.05% quaternary ammonium chloride and 1% saponated cresol diluted in hot water (greater than 60 degrees C) are considered as effective as UV irradiation. For unenveloped RNA viruses, halogen compounds, more than 1,000 ppm sodium hypochlorite or 260 ppm iodophor are recommended over a period of 10 minutes for disinfecting particles, although these compounds result in an oxidation problem with many metals.     

Canine distemper and related diseases: report of a severe outbreak in a kennel

An outbreak of canine distemper in a kennel of German shepherds in the province of Bari is reported. Six 42-day-old pups developed typical signs of canine distemper (fever, conjunctivitis, respiratory distress and enteritis) and died within 7-10 days. Neurological symptoms were observed only in one pup. Four additional pups, which had shown no sign of illness, were separated and vaccinated, but two of these developed a severe, fatal nervous form 15 days later. Post-mortem examination, carried out on two pups which died without neurological signs, showed pneumonia and enteritis, more severe in one of the two examined pups. Smears from the brain and the conjunctiva of both dogs tested positive for canine distemper virus (CDV) by an immunofluorescent assay, confirmed by the identification of viral RNA using RT-PCR. Bordetella bronchiseptica and a canine adenovirus strain, characterized as canine adenovirus type 2 by a differential PCR assay, were isolated from the lungs of the pup showing the most pronounced lesions. Furthermore, canine coronavirus was detected by PCR in the intestinal content of this pup, suggesting a multifactorial aetiology of the outbreak.     

TaqMan 荧光定量RT-PCR 检测犬瘟热病毒方法的建立与初步应用

犬瘟热（Canine distemper,CD）是由犬瘟热病毒（Canine distemper virus,CDV）感染引起的一种急性、高度接触性、致死性传染病.CDV属副粘病毒科麻疹病毒属成员,宿主谱很广,可感染犬（Canis familiaris）、狐狸（Vulpes vulpes）、貉（Ussuriensis）、狼（Canis lupus）、雪貂（Lepus zibellina）、虎（Panthera tigris）、狮（Panthera leo）、大熊猫（Ailuropoda melanoleuca）、小熊猫（Ailures fulgens）、黑熊（Selenarctas thibetanus）等动物,严重危害养犬业、经济动物养殖业的健康发展以及野生动物的生存.     

A serologic survey of the island fox (Urocyon littoralis) on the Channel Islands, California.

The island fox is listed as a threatened species in California. A serologic survey of 194 island foxes (Urocyon littoralis) was conducted over the entire range of the species on the Channel Islands (California, USA). Antibody prevalence against canine adenovirus and canine parvovirus reached 97% and 59%, respectively, in some populations sampled. Antibody prevalence of canine herpesvirus, canine coronavirus, leptospirosis and toxoplasmosis were low. Antibodies against canine distemper virus were not detected.     

犬瘟热病毒核蛋白基因重组腺病毒的构建、鉴定与表达

核蛋白基因(N)位于犬瘟热病毒基因组的108—1679位置处,是保守性较强的免疫原性蛋白,因此选择N基因作为目的基因,利用酶切、连接等方法构建了含犬瘟热病毒核蛋白基因的穿梭质粒pVAX?E3LPN。以含CAV-2SY株全基因组的pPoly2-CAV-2为载体,构建了重组质粒pCAV-2-CDVLPN,利用脂质体介导法转染MDCK细胞,转染三次后,细胞出现了典型的腺病毒样病变。电镜负染、切片观察,酶切、PCR扩增及测序鉴定的结果表明表达犬瘟热核蛋白基因的重组犬2型腺病毒构建成功,表达的核蛋白分子量为58kDa。