Clinical evaluation of a rapid diagnostic test kit for detection of canine coronavirus / 대한수의학회지

Canine coronavirus is a single-stranded RNA virus that causes enteritis in dogs of any age. Coronaviral enteritis is seldom definitively diagnosed, since it is usually much less severe than many other types of enteritis and is self-limiting. Conventional diagnostics for the canine coronaviral enteritis such as polymerase chain reaction (PCR), virus isolation, and electron microscopic examination are inappropriate for small animal clinics due to the complicated experimental processes involved. Therefore, a commercially available lateral flow test kit based on chromatographic immunoassay techniques was tested to evaluate its performance as a first-line diagnostic test kit that could be used in clinics. The coronavirus antigen test kit detected canine coronavirus-infected dogs with 93.1% sensitivity and 97.5% specificity. The detection limit of the test kit was between 1.97 × 10⁴/mL and 9.85 × 10³/mL for samples with a 2-fold serial dilution from 1.25 × 10⁶ TCID₅₀ (TCID₅₀, 50% tissue culture infectious dose). Additionally, the test kit had no cross-reactivity with canine parvovirus, distemper virus, or Escherichia coli. Overall, the commercially available test kit showed good diagnostic performance in a clinical setting, with results similar to those from PCR, confirming their potential for convenient and accurate use in small animal clinics.

Molecular stability of a vaccine strain of Canine coronavirus after serial passages in A72 cells / Estabilidade molecular de uma amostras vacinal de Coronavírus canino após passagens seriadas em células A72

Canine coronavirus (CCoV) exists in types I and II and infects dogs leading mainly to enteritis, though type II has already been associated with generalized and highly lethal infection. A CCoV-type II inactivated vaccine produced in A72 canine cells is available worldwide and largely used, though the molecular stability after serial passages of vaccine seeds is unknown. This article reports the evolution of the CCoV-II vaccine strain 1-71 in A72 cells based on partial S gene sequencing, showing the predominance of neutral evolution and the occurrence of four sites under purifying selection. Thus, cell-adapted strains of CCoV-II may be genetically stable after serial passages in a same cell line due to a stable virus-host relationship.(AU)

O Coronavírus canino (CCoV) ocorre como tipos I e II e infecta cães, levando principalmente a enterite, apesar do tipo II já ter sido associado à infecção generalizada e altamente letal. Uma vacina de CCoV-II inativada produzida em células caninas A72 é disponível mundialmente e largamente utilizada, apesar da sua estabilidade molecular após passagens seriadas de sementes vacinais ser desconhecida. Este artigo relata a evolução da amostra vacinal CCoC-II 1-71 em células A-72 com base em sequenciamento parcial do gene S, demonstrando predomínio de evolução neutra e a ocorrência de quaro sítios sob seleção purificante. Portanto, amostras de CCoV-II adaptadas a cultivos celulares podem ser estáveis geneticamente após passagens seriadas em uma mesma linhagem celular devido à existência de uma relação estável vírus-hospedeiro.(AU)

M gene analysis of canine coronavirus strains detected in Korea

The purpose of this study was to investigate the genetic features of canine coronavirus (CCV) strains detected in Korea. M gene sequences obtained for isolates from 22 dogs with enteritis over a 5-year period were evaluated. Sequence comparison revealed that the 22 Korean CCV strains had an 87.2 to 100% nucleotide homology. Comparing to the typical reference CCV strains (type II), the nucleotide sequence of Korean strains had homology ranged from 86.3% to 98.3% (89.1% to 99.2% for the amino acid sequence) and 87.7% to 97.8% (92.4% to 100% for the amino acid sequence) when compared to FCoV-like CCV strains (type I). Three amino acid variations in the M gene were characteristic for the Korean CCV strains. Phylogenetic analysis demonstrated that the 22 Korean CCV strains belonged to four typical CCV clusters (i.e., a unique Korean CCV cluster, a type II and transmissible gastroenteritis virus cluster, an intermediate cluster between type I and II, and a type I cluster). This study was the first to identify genetic differences of the M gene from Korean CCV strains and provided a platform for molecular identification of different Korean CCV strains.

Phylogeny of canine coronavirus (CCoV) from Brazilian dogs based on membrane protein partial sequences / Filogenia de Coronavírus canino (CCoV) de cães brasileiros com base em sequências parciais da proteína de membrana

Este artigo descreve a anteriormente desconhecida diversidade molecular de amostras brasileiras de Coronavírus canino (CCoV). Vinte e duas amostras foram submetidas à análise da sequência parcial do gene codificador da proteína de membrana, sendo 12 classificadas como CCoV Tipo II e 10 como CCoV Tipo I e uma possível sublinhagem tipicamente brasileira foi encontrada para o CCoV Tipo II.

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.

first report of concurrent detection of canine parvovirus and coronavirus in diarrhoeic dogs of Iran

Two male dogs at the age of 3 and 5 months of Doberman pinscher and German shepherd breeds were referred to the Veterinary Hospital of Ahvaz University with clinical signs of depression, vomiting, haemorrhagic diarrhoea, profound dehydration, fever and anorexia. The affected dogs had not the history of vaccination. Concurrent infection of canine parvovirus and coronavirus was detected in dogs by means of immunochromatography assay. The haemogram showed lowered white blood cell counts as leukopenia, neutropenia and lymphopenia. The dogs received supportive treatment to correct the life-threatening dehydration and prevention of secondary bacterial infections. Despite treatment, one dog [Doberman pinscher] died within 3 days after the onset of clinical signs, and the second dog recovered after 4 days. To the best of our knowledge, this is the first report of concurrent infection of canine parvovirus and coronavirus in diarrhoeic dogs in Iran

[Antigenic detection of Canine Coronavirus in diarrheic dogs in Ahvaz]

The Purpose of this study was to evaluate the prevalence of Canine Coronavirus [CCV] in diarrheic dogs of Ahvaz district. Fecal samples were collected from 58 diarrheic dogs between 2005 and 2006. Dogs were grouped by age [less than and above 6 months], sex, breed, geographical location [urban and rural] and quality of diarrhea [hemorrhagic and non-hemorrhagic] to determine whether these factors were associated with coronavirus infection, using Fischer's exact test. Prevalence to CCV antigens in these dogs was 3.45% [2 of 58] by means of immunochromatography assay [IC] indicating that this virus is present in the environment. Though the infection had more prevalence in dogs less than 6 months, rural dogs and German shepherds, but there were no significant differences between different sexes, age groups, breeds, location and quality of diarrhea [p>0.05]. CBC in 2 dogs that were affected with coronavirus infection was normal. This study that is the first report on prevalence of CCV in Iran showed that CCV infection in the Ahvaz dogs may be attributed as a cause of viral diarrhea in dogs. A vaccine is recommended, especially for open population and kennel dogs that are at a high risk for contacting the virus