A canine influenza A(H3N2) virus emerged in the United States in February-March 2015, causing respiratory disease in dogs. The virus had previously been circulating among dogs in Asia, where it originated through the transfer of an avian-origin influenza virus around 2005 and continues to circulate. Sequence analysis suggests the US outbreak was initiated by a single introduction, in Chicago, of an H3N2 canine influenza virus circulating among dogs in South Korea in 2015. Despite local control measures, the virus has continued circulating among dogs in and around Chicago and has spread to several other areas of the country, particularly Georgia and North Carolina, although these secondary outbreaks appear to have ended within a few months. Some genetic variation has accumulated among the US viruses, with the appearance of regional-temporal lineages. The potential for interspecies transmission and zoonotic events involving this newly emerged influenza A virus is currently unknown.
A 32-month-old spayed female Singapura cat presented with a non-pruritic erythematous nodule on the upper lip. The cat also had multiple nodules in the liver but exhibited no other clinical signs consistent with classical feline infectious peritonitis (FIP), such as pleural effusion or ascites, uveitis or neurological symptoms. Histopathological and immunohistochemical analyses of the cutaneous nodule revealed pyogranulomatous dermatitis with intralesional macrophages laden with feline coronavirus (FCoV) antigen. Real-time reverse transcription (RT)-PCR of a cutaneous sample revealed a single nucleotide substitution in the spike protein gene of FCoV (mutation M1058L), which is consistent with an FCoV genotype commonly associated with FIP. The cat received a blood transfusion and supportive therapy, but the owner declined to continue the treatments owing to poor response. The cat was lost to follow-up 5 months after discharge.This report describes a case of a coronavirus-associated cutaneous nodule in which the evidence of amino acid changes in the spike protein gene identified by RT-PCR were consistent with an FCoV genotype commonly seen in cases of FIP. To the best of our knowledge, this is the first report of a case of cutaneous disease associated with the mutated FCoV that was confirmed by molecular diagnostic testing.
The focus of rapid diagnosis of infectious disease of horses in the last decade has shifted from the conventional laboratory techniques of antigen detection, microscopy, and culture to molecular diagnosis of infectious agents. Equine practitioners must be able to interpret the use, limitations, and results of molecular diagnostic techniques, as they are increasingly integrated into routine microbiology laboratory protocols. Polymerase chain reaction (PCR) is the best‐known and most successfully implemented diagnostic molecular technology to date. It can detect slow‐growing, difficult‐to‐cultivate, or uncultivatable microorganisms and can be used in situations in which clinical microbiology diagnostic procedures are inadequate, time‐consuming, difficult, expensive, or hazardous to laboratory staff. Inherent technical limitations of PCR are present, but they are reduced in laboratories that use standardized protocols, conduct rigid validation protocols, and adhere to appropriate quality‐control procedures. Improvements in PCR, especially probe‐based real‐time PCR, have broadened its diagnostic capabilities in clinical infectious diseases to complement and even surpass traditional methods in some situations. Furthermore, real‐time PCR is capable of quantitation, allowing discrimination of clinically relevant infections characterized by pathogen replication and high pathogen loads from chronic latent infections. Automation of all components of PCR is now possible, which will decrease the risk of generating false‐positive results due to contamination. The novel real‐time PCR strategy and clinical applications in equine infectious diseases will be the subject of this review.
Abstract We have identified cDNAs and characterized the expression of 13 novel cytochrome P450 genes of potential importance in host colonization and reproduction by the California fivespined ips, Ips paraconfusus . Twelve are of the Cyp4 family and one is of the Cyp9 family. Following feeding on host Pinus ponderosa phloem, bark beetle transcript levels of several of the Cyp4 genes increased or decreased in males only or in both sexes. In one instance (IparaCyp4A5) transcript accumulated significantly in females, but declined significantly in males. The Cyp9 gene (Cyp9T1) transcript levels in males were > 85 000 × higher at 8 h and > 25 000 × higher at 24 h after feeding compared with nonfed controls. Transcript levels in females were approximately 150 × higher at 24 h compared with nonfed controls. Cyp4G27 transcript was present constitutively regardless of sex or feeding and served as a better housekeeping gene than β‐actin or 18S rRNA for the real‐time TaqMan polymerase chain reaction analysis. The expression patterns of Cyp4AY1, Cyp4BG1, and, especially, Cyp9T1 in males suggest roles for these genes in male‐specific aggregation pheromone production. The differential transcript accumulation patterns of these bark beetle P450s provide insight into ecological interactions of I. paraconfusus with its host pines.
Lymphoplasmacytic rhinitis (LPR) is a common histologic finding in dogs with chronic nasal disease; however, potential etiologies of this disorder have not been examined. We investigated the hypothesis that specific microbes contribute to clinical disease in dogs with LPR. Paraffin-embedded nasal biopsies were obtained from 19 dogs with LPR, 10 dogs with nasal neoplasia, and 10 dogs with nasal aspergillosis. Nucleic acids were extracted from paraffin blocks, and real-time quantitative polymerase chain reaction (PCR) was employed for detection of target genes for bacterial and fungal DNA, canine adenovirus 2 (CAV-2), parainfluenza virus 3 (PI-3), Chlamydial Chlamydophila spp., and Bartonella spp. Conventional PCR was used for detection of Mycoplasma spp. Statistical analysis was performed using the Mann-Whitney U-test for nonparametric data, and significance was set at P < 0.05. DNA or RNA for CAV-2, PI-3, Bartonella, Mycoplasma, and Chlamydophila was not detected in any nasal biopsy. DNA loads for bacterial DNA did not differ among disease groups. Detection of fungal DNA in nasal biopsies was highest in dogs with aspergillosis (P < 0.0001); however, nasal biopsies of LPR dogs also displayed higher fungal DNA levels than samples from dogs with nasal neoplasia (P = 0.016). Detection of high levels of fungal DNA in nasal biopsies of dogs with LPR suggests that fungal organisms may be causally associated with the inflammation observed, although the possibility of entrapment or accumulation of fungi in the nasal cavity due to chronic inflammation cannot be excluded. Further investigations are required to elucidate the underlying etiopathogenesis of LPR.
We characterized the complete genome of a novel dog circovirus (DogCV) from the liver of a dog with severe hemorrhagic gastroenteritis, vasculitis, and granulomatous lymphadenitis. DogCV was detected by PCR in fecal samples from 19/168 (11.3%) dogs with diarrhea and 14/204 (6.9%) healthy dogs and in blood from 19/409 (3.3%) of dogs with thrombocytopenia and neutropenia, fever of unknown origin, or past tick bite. Co-infection with other canine pathogens was detected for 13/19 (68%) DogCV-positive dogs with diarrhea. DogCV capsid proteins from different dogs varied by up to 8%. In situ hybridization and transmission electron microscopy detected DogCV in the lymph nodes and spleens of 4 dogs with vascular compromise and histiocytic inflammation. The detection of a circovirus in tissues of dogs expands the known tropism of these viruses to a second mammalian host. Our results indicate that circovirus, alone or in co-infection with other pathogens, might contribute to illness and death in dogs.
