Comparison of feline parvovirus subspecific strains using monoclonal antibodies against a feline panleukopenia virus

Four monoclonal antibodies (mAb) against a feline panleukopenia virus (FPLV) TU 1 strain, one of the host range variants of feline parvovirus (FPV), were produced and applied for antigenic analysis of FPLV, canine parvovirus (CPV) and mink enteritis virus (MEV). All mAbs were considered to be directed at epitopes on the virus capsid surface because they neutralized the infectivity and inhibited the hemagglutination (HA) of the homologous virus as well as other FPV strains. They were of the mouse IgG1 type. High antigenic homogeneity among FPLV strains was confirmed by HA-inhibition (HI) test with the mAbs and polyclonal immune sera against FPLV or CPV. But the TU 11 strain of FPLV was antigenically distinguished from the remaining 14 FPLV strains by both the HI test and the micro-neutralization test with one of the mAbs produced. MEV Abashiri strain was found to be antigenically indistinguishable from FPLV. Most of the CPV strains isolated after 1981 were considered to be antigenically different from earlier CPV isolates when some mAbs were applied in the serological tests, confirming the replacement of CPV by an antigenic variant in Japan. However, antigenically different CPVs were detected at the end of 1984 from unrelated epizootics occurred a month apart in the same area.     

Efficacy of an inactivated feline panleucopenia virus vaccine against a canine parvovirus isolated from a domestic cat

Canine parvovirus type 2a (CPV-2a) and type 2b (CPV-2b) have recently been isolated from cats throughout the world, and CPV-2b strain FP84 has been reported to be virulent in domestic cats. Although live feline panleucopenia virus (FPLV) vaccines protect domestic cats from CPV infection, the efficacy of inactivated FPLV vaccines has not been established. In this study, two domestic cats were vaccinated with a commercial inactivated FPLV vaccine and challenged with CPV-2b strain FP84 isolated from a domestic cat. The cats were protected against CPV-2b strain FP84 infection and their clinical signs were suppressed, although the two unvaccinated cats showed the typical clinical signs of parvovirus infection.     

An outbreak of canine distemper virus in tigers (Panthera tigris): possible transmission from wild animals to zoo animals

Canine distemper virus (CDV), a morbillivirus that causes one of the most contagious and lethal viral diseases known in canids, has an expanding host range, including wild animals. Since December 2009, several dead or dying wild raccoon dogs (Nyctereutes procyonoides) were found in and around one safari-style zoo in Japan, and CDV was isolated from four of these animals. In the subsequent months (January to February 2010), 12 tigers (Panthera tigris) in the zoo developed respiratory and gastrointestinal diseases, and CDV RNA was detected in fecal samples of the examined tigers. In March 2010, one of the tigers developed a neurological disorder and died; CDV was isolated from the lung of this animal. Sequence analysis of the complete hemagglutinin (H) gene and the signal peptide region of the fusion (F) gene showed high homology among these isolates (99.8-100%), indicating that CDV might have been transmitted from raccoon dog to tiger. In addition, these isolates belonged to genotype Asia-1 and had lower homology (<90%) to the vaccine strain (Onderstepoort). Seropositivity of lions (Panthera leo) in the zoo and wild bears (Ursus thibetanus) captured around this area supported the theory that a CDV epidemic had occurred in many mammal species in and around the zoo. These results indicate a risk of CDV transmission among many animal species, including large felids and endangered species.     

Use of modified live feline panleukopenia virus vaccine to immunize dogs against canine parvovirus

Modified live feline panleukopenia virus (FPLV) vaccine protected dogs against canine parvovirus (CPV) infection. However, unlike the long-lived (greater than or equal to 20-month) immunity engendered by CPV infection, the response of dogs to living FPLV was variable. Doses of FPLV (snow leopard strain) in excess of 10(5.7) TCID50 were necessary for uniform immunization; smaller inocula resulted in decreased success rates. The duration of immunity, as measured by the persistence of hemagglutination-inhibiting antibody, was related to the magnitude of the initial response to vaccination; dogs with vigorous initial responses resisted oronasal CPV challenge exposure 6 months after vaccination, and hemagglutination-inhibiting antibodies persisted in such dogs for greater than 1 year. Limited replication of FPLV in dogs was demonstrated, but unlike CPV, the feline virus did not spread to contact dogs or cats. Adverse reactions were not associated with living FPLV vaccination, and FPLV did not interfere with simultaneous response to attenuated canine distemper virus.     

Characterisation of cross-reactivity of virus neutralising antibodies induced by feline panleukopenia virus and canine parvoviruses

It was recently reported that canine parvoviruses (CPV) had entered cat populations and induced disease in infected cats, while they had affected only dogs in the past. It is important to determine whether conventional feline panleukopenia virus (FPLV) vaccines protect against recent CPV infections. In this study, the cross-reactivity of virus-neutralising (VN) and haemagglutinin-inhibition (HI) antibodies in cats induced by FPLV and CPV s were examined. Lower cross-reactivities of VN and HI antibodies against each CPV strain were observed in cats experimentally inoculated with FPLV or vaccinated with an inactivated FPLV vaccine. In addition, we revealed the existence of a novel type of FPLV, which reacted weakly with antibodies induced by the conventional FPLV vaccine.     

Neutralizing antibodies against feline parvoviruses in nondomestic felids inoculated with commercial inactivated polyvalent vaccines

The virus neutralization (VN) antibody titers of serum samples from 18 individuals representing 8 carnivore species vaccinated with commercial polyvalent vaccines optimized for domestic cats containing inactivated feline panleukopenia virus (FPLV) were evaluated against canine parvovirus type 2 (CPV2). In addition, the titers among 5 individuals from 4 carnivore were evaluated against antigenic variants of feline parvoviruses; FPLV, CPV2, CPV2a, CPV2b, CPV2c, mink enteritis virus type 1 (MEV1) and MEV2. The polyvalent vaccines induced cross-reactive VN titers against antigenic variants of feline parvoviruses in nondomestic felids. However, we observed very low cross-reactive VN antibody in lions and Siberian tigers, therefore we should pay attention to CPV infections in these animals even if they were vaccinated with inactivated FPLV vaccines.     

Prepubic urethrostomy and placement of a caudal superficial epigastric flap for treatment of a self-mutilation injury in a serval

A 10-year-old male serval was examined for treatment of a self-inflicted perineal wound that obliterated the ventral anocutaneous junction, penis, scrotum, testicles, and proximal portions of the caudomedial thigh muscles. Repair required placement of a caudal superficial epigastric flap and prepubic urethrostomy. Although it is generally preferable to delay repair of contaminated wounds until a healthy wound bed is established, circumstances related to wound location, affected tissues, and patient compliance led to a decision for immediate wound closure. In this serval, a history of food intolerance, recent diet change, eosinophilia, and eosinophilic granuloma-like skin lesions suggested that the self-mutilation injury was a result of food hypersensitivity, although foreign body or a spider bite could not be ruled out.     

貉细小病毒LN10-1株分离鉴定及其免疫原性研究

为研制貉细小病毒性肠炎疫苗,筛选出针对貉细小病毒性肠炎免疫原性好、安全高效的疫苗备选株,应用CRFK细胞从辽宁省发病貉的粪便中分离病毒,并通过形态学、血清学、分子生物学、动物回归及免疫接种等方法对分离株进行鉴定。鉴定结果表明成功分离出1株貉细小病毒,命名为LN10-1株。其VP2基因核苷酸序列与猕猴源猫泛白细胞综合征病毒株(BJ-22/2008/CHN株)相似性高达99.7%。VP2蛋白上决定宿主范围的2个氨基酸位点发生了突变。VP2基因种系发生分析显示,LN10-1株位于猫泛白细胞综合征病毒(Feline panleukopenia virus,FPLV)、蓝狐细小病毒(Blue fox parvovirus,BFPV)、水貂肠炎病毒(Mink enteritis virus,MEV)组成的食肉类动物细小病毒聚类分支与由犬细小病毒(Canine parvovirus,CPV)组成的聚类分支。由LN10-1株制备的灭活疫苗免疫结果显示,接种28d细小病毒中和抗体滴度可达到1∶256以上。推测LN10-1株可能正处于FPLV与CPV进化的中间状态,或是CPV适应新宿主(貉)而形成的一种新病毒,可以作为针对貉细小病毒性肠炎灭活疫苗的候选株。     

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（red panda)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％，雅安碧峰峡生态动物园小熊猫死亡4只，死亡率为25％。两地发病小熊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。从雅安碧峰峡生态动物园患病小熊猫分离出的犬瘟热毒株（cdv2株）对VERO细胞适应性比从重庆动物园分离的（cdv1株）强，其TCID50达10^-6/0.2mL，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。     

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca)

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV.     

Enterocolitis associated with dual infection by Clostridium piliforme and feline panleukopenia virus in three kittens

Dual infection by Clostridium piliforme and feline panleukopenia virus (FPLV) was found in three kittens. In all cases, we found focal necrosis and desquamation of epithelial cells with occasional neutrophil infiltration in the large intestine. Large filamentous bacilli and spores were observed in the epithelium by using the Warthin-Starry method. Electron microscopy revealed the vegetative forms with characteristic peritrichous flagella and spore forms. Immunohistochemically, these bacilli showed a positive reaction with mouse antisera against the RT and MSK C. piliforme strains. Polymerase chain reaction (PCR) using cecum specimens demonstrated the 196-bp band specific to C. piliforme 16S rRNA. All three kittens were also diagnosed as FPLV-infected on the basis of the characteristic mucosal lesions, including intranuclear inclusions and PCR study for the FPLV genomic DNA. The PCR techniques are useful for confirming the C. piliforme and FPLV infection in spontaneous cases.     

Antigenic and genomic comparisons of some feline parvovirus subspecies strains.

Fourteen feline parvovirus (FPV) strains isolated from cats, mink and dogs were comparatively examined on their antigenic and genetic diversities by using monoclonal antibodies against feline panleukopenia virus (FPLV) and restriction enzyme analysis of viral DNA. Mink enteritis virus (MEV) strains recently isolated in the northeastern area of the People's Republic of China were found to possess more similar antigenic and genetic properties to the antigenic variant virus of canine parvovirus (CPV) ("new" antigenic type CPV), than to FPLV strains and MEV Abashiri strain of Japan. A feline isolate detected in normal cat feces was considered to be rather CPV because of its antigenic and genetic characteristics. An early isolate of "new" antigenic type CPV strains showed a similar cleavage pattern to those of "old" antigenic type CPV strains when digested with HinfI. The results including some features above-mentioned suggest the presence of antigenic heterogeneities and genomic polymorphisms among FPV subspecies viruses.     

Efficacy of feline panleucopenia vaccine to prevent infection with an isolate of CPV2b obtained from a cat.

Cats vaccinated against FPLV were protected against infection with a feline isolate of CPV2b. Nonvaccinated cats developed a lymphopenia and excreted virus which infected susceptible in-contact cats.     

猎豹与虎猫杯状病毒的分离及其超变区基因比较研究

用F81细胞从上海某动物园患口腔溃疡的猎豹和虎的唾液病料中分离获得两株杯状病毒，经形态学、理化学、生物学鉴定和病毒核酸超变区基因RT-PCR扩增与序列测定证明两株病毒均为猫杯状病毒(FCV)，分别命名为FCV/cheetah/Shanghai/02/2002与FCV／tiger/Shanghai／03/2002。人工感染猫可引起体温升高，口腔溃疡，食欲下降等症状。两株病毒的超变区序列520bp长片段问的同源性为99.2％，与国内桂林虎分离株(TFCV9710)的同源性为74．0％，与国外分离株的总体同源性为58．1％，说明不同宿主或同种不同个体间杯状病毒分离株超变区核酸差异十分显著，符合猫杯状病毒的分子生物学特征。     

Cardiopulmonary and anesthetic effects of medetomidine-ketamine-butorphanol and antagonism with atipamezole in servals (Felis serval).

Seven (three male and four female) 4-7-yr old captive servals (Felis serval) weighing 13.7 +/- 2.3 kg were used to evaluate the cardiopulmonary and anesthetic effects of combined intramuscular injections of medetomidine (47.4 +/- 10.3 microg/kg), ketamine (1.0 +/- 0.2 mg/kg), and butorphanol (0.2 +/- 0.03 mg/kg). Inductions were smooth and rapid (11.7 +/- 4.3 min) and resulted in good muscle relaxation. Significant decreases in heart rate (85 +/- 12 beats/min) at 10 min after injection and respiratory rate (27 +/- 10 breaths/min) at 5 min after injection continued throughout the immobilization period. Rectal temperature and arterial blood pressure did not change significantly. The PaO2 decreased significantly, and PaCO2 increased significantly during immobilization but remained within clinically acceptable limits. Hypoxemia (PaO2 < 60 mm Hg) was not noted, and arterial blood oxygen saturation (SaO2) was greater than 90% at all times. Relative arterial oxygen saturation (SpO2) values, indicated by pulse oximetry, were lower than SaO2 values. All animals could be safely handled while sedated. Administration of atipamezole (236.8 +/- 51.2 microg/kg half i.v. and half s.c.), an alpha2 antagonist, resulted in rapid (4.1 +/- 3 min to standing) and smooth recoveries.     

Pandemic (H1N1) 2009 influenza A virus infection associated with respiratory signs in sloth bears (Melursus ursinus)

In 2009, a pandemic influenza A virus (pH1N1) spread globally in humans and infected a broad range of captive animals with close human contact. In February 2014, a pH1N1 virus was isolated from a sloth bear with respiratory signs at a US zoo, demonstrating that recurring epidemics present an ongoing threat to animals, including threatened species. This is the first report of pH1N1 infection in sloth bears. To understand the sloth bear virus within the global context of pH1N1, phylogenetic trees were inferred including full‐length sequences from available non‐human, non‐swine hosts, representing four families in the order Carnivora and one order of birds. A combination of phylogenetic and epidemiological evidence strongly suggests the sloth bear was infected with a human‐origin pH1N1 virus, supporting the implementation of biosecurity measures to protect human and animal health.     

Canine parvovirus in asymptomatic feline carriers

Canine parvovirus (CPV) and feline panleukopaenia virus (FPLV) are two closely related viruses, which are known to cause severe disease in younger unvaccinated animals. As well as causing disease in their respective hosts, CPV has recently acquired the feline host range, allowing it to infect both cats and dogs. As well as causing disease in dogs, there is evidence that under some circumstances CPV may also cause disease in cats. This study has investigated the prevalence of parvoviruses in the faeces of clinically healthy cats and dogs in two rescue shelters. Canine parvovirus was demonstrated in 32.5% (13/50) of faecal samples in a cross sectional study of 50 cats from a feline only shelter, and 33.9% (61/180) of faecal samples in a longitudinal study of 74 cats at a mixed canine and feline shelter. Virus was isolated in cell cultures of both canine and feline origin from all PCR-positive samples suggesting they contained viable, infectious virus. In contrast to the high CPV prevalence in cats, no FPLV was found, and none of 122 faecal samples from dogs, or 160 samples collected from the kennel environment, tested positive for parvovirus by PCR. Sequence analysis of major capsid VP2 gene from all positive samples, as well as the non-structural gene from 18 randomly selected positive samples, showed that all positive cats were shedding CPV2a or 2b, rather than FPLV. Longitudinally sampling in one shelter showed that all cats appeared to shed the same virus sequence type at each date they were positive (up to six weeks), despite a lack of clinical signs. Fifty percent of the sequences obtained here were shown to be similar to those recently obtained in a study of sick dogs in the UK (Clegg et al., 2011). These results suggest that in some circumstances, clinically normal cats may be able to shed CPV for prolonged periods of time, and raises the possibility that such cats may be important reservoirs for the maintenance of infection in both the cat and the dog population.     

Factors associated with antimicrobial-resistant Escherichia coli in zoo animals

Factors associated with the carriage of antimicrobial-resistant Escherichia coli isolates were analysed among zoo animals. An association was observed between selection of amoxicillin as the first-line therapy and a significantly higher percentage of resistance to ampicillin (54.5%) from 11 animals treated with antimicrobials, compared with isolates from 32 untreated animals (9.4%). In addition, the percentage resistance to kanamycin (36.4%), gentamicin (27.3%), trimethoprim (27.3%) and tetracycline (63.6%) from 11 treated animals was significantly higher than those from 32 untreated animals (3.1%, 3.1%, 3.1% and 25%, respectively), although these antimicrobials were rarely used. All kanamycin-, gentamicin- and trimethoprim-resistant isolates and more than half of the tetracycline-resistant isolates from treated animals were also resistant to ampicillin. Co-resistance to other antimicrobials with ampicillin was suggested to contribute to an increasing of resistance towards antimicrobials that were rarely administered. The present investigation revealed an association of antimicrobial treatment with the spread of antimicrobial-resistant bacteria among zoo animals.     

Heterogeneity of ruminant pestiviruses: academic interest or important basis for the development of vaccines and diagnostics?

Pestiviruses cause economically important diseases of farm animals. Members of the Pestiviruses are bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, classical swine fever virus (CSFV) and border disease virus (BDV). Phylogenetic analyses based on the entire nucleic acid sequence encoding the Npro allow a statistically significant segregation of established species and of subgroups within the species. BVDV-1 strains isolated in Germany can be associated with at least five different subgroups. In contrast all BVDV-2 isolates detected in Germany so far are closely related, belonging to one subgroup. A group of virus isolates from sheep and zoo animals is clearly different from established pestivirus species and can be designated as BDV-2. Antigenetic relatedness of pestiviruses was studied using defined virus isolates and antisera in cross-neutralization assays. Six antigenic groups were distinguished corresponding to the genetic clusters BVDV-1, BVDV-2, CSFV, BDV-1, BDV-2 and Giraffe-1. A significant antigenic difference was also observed between members of subgroups 1a and 1b of BVDV-1. Studies on the genetic and antigenic heterogeneity of pestiviruses are important for the development of new vaccines, diagnostic tests and for eradication programs.