Feline Morbillivirus Research Articles

Emerging Viral Disease in Cats: Feline Morbillivirus Involved in Chronic Renal Failure

Emerging Viral Disease in Cats: Feline Morbillivirus Involved in Chronic Renal Failure

Current Status and Issues of Feline Morbillivirus Research :

Current Status and Issues of Feline Morbillivirus Research :

First report of feline morbillivirus in South America.

Feline morbillivirus was first identified in healthy and diseased stray cats captured in Hong Kong. Recently, it was demonstrated that the virus circulates within cat populations in Japan, Italy, Germany, and the USA. Importantly, an association between feline morbillivirus infection and chronic kidney disease was suggested by histological analysis of kidney tissue of infected cats. The aim of this study was to verify the presence and examine the genetic diversity of feline morbilliviruses associated with infections of domestic cats in Brazil. Seventeen cats without clinical manifestations of urinary tract diseases from a multi-cat household and 35 random client-owned cats admitted to the Teaching Veterinary Hospital for a variety of reasons were evaluated for paramyxoviral infection and the presence of uropathy. A fragment of the paramyxoviral L gene was amplified from urine samples using a reverse transcription semi-nested PCR assay. For the first time, we detected a feline morbillivirus strain that was genetically related to viral strains previously characterized in Japan in urine samples from cats in South America, in Brazil. This together with the recent description of feline morbillivirus identification within cat populations in the USA, suggests a possible widespread distribution of this viral agent on the American continent. Our data demonstrated feline morbillivirus RNA shedding mostly in the urine of cats without clinical, laboratorial, or ultrasonographic signs of urinary tract diseases. In contrast to previously published findings that associated feline morbillivirus infection with chronic kidney disease, we did not observe a clear relationship between feline morbillivirus RNA shedding in urine and kidney disease in the cats evaluated.

Epidemiological and pathological study of feline morbillivirus infection in domestic cats in Japan.

BackgroundFeline morbillivirus (FmoPV) is a novel paramyxovirus found to infect domestic cats. FmoPV has been isolated in several countries in Asia and Europe and is considered to have genetic diversity. Also, it is suspected to be associated with feline renal diseases including tubulointerstitial nephritis (TIN), which affects domestic cats with a high incidence rate.ResultsTo clarify the state of FmoPV infection among domestic cats in Japan, an epidemiological survey was conducted. Twenty-one out of 100 cats were found to have serum antibodies (Ab) against FmoPV-N protein by indirect immunofluorescence assay (IF) using FmoPV-N protein-expressing HeLa cells. Twenty-two of the cats were positive for FmoPV RNA in the urine and/or renal tissues. In total, 29 cats were positive for Ab and/or viral RNA. These FmoPV-infected cats were classified into three different phases of infection: RNA+/Ab + (14 cats), RNA+/Ab- (8 cats) and RNA-/Ab + (7 cats). In immunohistochemistry (IHC), 19 out of 29 cats were positive for FmoPV-N protein in kidney tissues; however, the FmoPV-N protein was located in the inflammatory lesions with severe grade in only four out of the 19 cats. Since 15 out of 29 infected cats were positive for viral RNA and Ab, approximately half of the infected cats were persistently infected with FmoPV.ConclusionsA statistically significant difference was observed between infection of FmoPV and the presence of inflammatory changes in renal lesions, indicating a relationship between FmoPV infection and feline renal diseases. However, we could not obtain histopathological evidence of a relationship between FmoPV infection and TIN.

Genome characterization of feline morbillivirus from Italy

Feline morbillivirus (FeMV) has been recently identified by RT-PCR in the urine sample of a nephropathic cat in Italy. In this report, we describe the whole genome sequence of strain Piuma/2015 obtained by combination of sequence independent single primer amplification method (SISPA) and next generation sequencing (NGS) starting from RNA purified from the infected urine sample. The existence in Germany and Turkey of FeMVs from cats divergent from Piuma/2015, suggests the presence of FeMV heterogeneity in Europe as it has been described previously in Japan and China.

Discovery and current research status of feline morbillivirus.

Feline morbillivirus (FeMV) is an emerging virus that was first discovered in Hong Kong in 2012. FeMV is epidemiologically associated with kidney and other lower urinary tract diseases in cats. Phylogenetic analysis of its genome sequence indicates that FeMV is the most closely related to the members of genus morbillivirus, although FeMV is relatively distant in the phylogenetic analysis, and its target tissues and pathogenicity are different from the other members of the genus. The origin and routes of dissemination of FeMV are not clear since genetic types are not always correlated to the geographical distribution of the isolates. Since the discovery of the virus, several reports showed the epidemiological association of FeMV infection with kidney and lower urinary tract diseases in cats. However, the pathogenicity of FeMV is not clear yet due to paucity of the isolated virus strains and chronic nature of the subjected diseases. Diagnosis of FeMV infection has been performed using both nucleic acid and serological methods. However, there are no standard diagnostic methods to detect antibodies against FeMV, which will be useful to study epidemiology and pathogenicity of FeMV. Besides FeMV is an interesting subject as an additional member to the morbilliviruses possessing unusual characteristics comparing to the other morbilliviruses, further studies of FeMV is important in the veterinary field since it may lead to new therapies or prevention of chronic kidney diseases of cats.

Discovery of new feline paramyxoviruses in domestic cats with chronic kidney disease.

Paramyxoviruses constitute a large family of enveloped RNA viruses including important pathogens in veterinary and human medicine. Recently, feline paramyxoviruses, genus morbillivirus, were detected in cats from Hong Kong and Japan. Here we describe the discovery of several new feline paramyxoviruses. Infections with these diverse viruses were detected in urine samples from cats suffering from chronic kidney disease (CKD). No viral RNA was found in cats without clinical signs of uropathy highlighting an association between feline paramyxovirus (FPaV) infections and CKD. Phylogenetic analyses of the detected viruses showed that they represent at least two different species, one of them representing the feline morbilliviruses detected previously in Hong Kong and Japan. In addition, a new FPaV was detected sharing only 73 % homology on the nucleotide level of the viral L-gene to currently known paramyxoviral species.

Rapid detection of feline morbillivirus by a reverse transcription loop-mediated isothermal amplification.

Feline morbillivirus (FmoPV) is an emerging virus in domestic cats and considered to be one of the causes of chronic renal failure in cats. In this study, we established a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of FmoPV. The results indicated that the detection limit of the assay was 10 50% tissue culture infective dose (TCID50)/ml in the original sample, and sensitivity of the assay was calculated as 0.12 TCID50 per one RT-LAMP reaction. We also detected FmoPV in clinical urine samples from cats infected with FmoPV. The FmoPV RT-LAMP assay is rapid, simple and highly specific for the detection of FmoPV, and thus, it would be a reliable detection method for FmoPV.

Quantitative PCR detection of feline morbillivirus in cat urine samples.

Feline morbillivirus (FmoPV) is a new virus species and its detection is important, since correlation has been reported between FmoPV virus infection and tubulointerstitial nephritis in cats. Here, we report a real-time reverse transcription (RT)-PCR system that can detect the FmoPV L-gene sequence with more than 10-time higher sensitivity than a conventional PCR system, resulting in detection of less than 10 copies of the template DNA. The total FmoPV positive rate of urine samples from veterinary clinics and hospitals in Japan was 15.1% (25/166) using this system. This study demonstrates usefulness of the real-time RT-PCR system for detection of FmoPV for cat urine samples.

In vitro host range of feline morbillivirus.

Feline morbillivirus (FmoPV) is an emerging virus in cats, which is associated with tubulointerstitial nephritis. To study the in vitro host range of FmoPV, we inoculated FmoPV strain SS1 to 32 cell lines originated from 13 species and cultured for 2 weeks, followed by RNA extraction and reverse-transcription-polymerase chain reaction for FmoPV detection. As a result, only cell lines derived from cats and African green monkeys were susceptible to FmoPV. FmoPV infects diverse feline cell lines: epithelial, fibroblastic, lymphoid and glial cells. These results indicate that the receptor (s) for FmoPV are ubiquitously expressed in cats. No infectivity of FmoPV was observed in human cell lines, which suggests least threatening of cross-species transmission of FmoPV from cats to humans.

Basic biological characterization of feline morbillivirus.

Feline morbillivirus (FmoPV) is an emerging virus that was recently discovered in domestic cats with chronic nephritis. Despite the potential role of FmoPV in chronic nephritis, little is known about its biological characteristics. In this study, we established a quantitative assay of FmoPV by using an indirect immunofluorescence technique. Viral titers of FmoPV were determined in one week. Treatment with polybrene® or trypsin which was previously used in virus isolation did not augment the virus titers. FmoPV was notably stable at 4°C, retaining high titers for at least 12 days. Heat-treatment at 60°C and 70°C effectively inactivated FmoPV in 10 and 2 min, respectively. The biological characteristics of FmoPV reported here will be beneficial for establishing an efficient virus isolation method and will provide important information to take a measure to reduce the risk of FmoPV infection.

Identification of a natural recombination in the F and H genes of feline morbillivirus

Feline morbillivirus (FmoPV) has recently been identified in Hong Kong and Japan. FmoPV is considered to belong to the genus Morbillivirus, in the family Paramyxoviridae. In this study, the complete nucleotide sequences of three strains of FmoPV detected in cats in Japan were determined. Among the six genes in FmoPV; N, P/V/C, M, F, H and L, the P gene showed the highest polymorphism in the nucleotide and putative amino acid sequences among the FmoPV strains. There was no geographical association in terms of the FmoPV phylogeny; however, from extensive phylogenetic and recombination analyses, we found that one Japanese FmoPV strain, MiJP003, was a probable recombinant between two virus strains in the independent lineages found in Japan and Hong Kong, respectively. The recombination was considered to have occurred within the F and H genes. Such recombination is thought to be involved in the evolution of FmoPV.

Genetic diversity of feline morbilliviruses isolated in Japan.

Feline morbillivirus (FmoPV) is an emerging virus in domestic cats and considered to be associated with tubulointerstitial nephritis. Although FmoPV was first described in China in 2012, there has been no report of the isolation of this virus in other countries. In this report, we describe the isolation and characterization of FmoPV from domestic cats in Japan. By using reverse transcription (RT)-PCR, we found that three of 13 urine samples from cats brought to veterinary hospitals were positive for FmoPV. FmoPV strains SS1 to SS3 were isolated from the RT-PCR-positive urine samples. Crandell-Rees feline kidney (CRFK) cells exposed to FmoPV showed cytopathic effects with syncytia formation, and FmoPV N protein was detected by indirect immunofluorescence assays. In addition, pleomorphic virus particles with apparent glycoprotein envelope spikes were observed by electron microscopy. By sequence analysis of FmoPV H and L genes, we found that FmoPVs showed genetic diversity; however, signatures of positive selection were not identified.

Existence of feline morbillivirus infection in Japanese cat populations

Feline morbillivirus (FmoPV) is a member of a new virus species that has only been found in the Hong Kong cat population. For the first time, however, we have now detected nucleotide sequences similar to FmoPV in samples from Japanese cat populations. The positive rates for urine and blood samples from Japanese cats were 6.1 % (5/82) and 10 % (1/10), respectively. These sequences are similar to the previously reported FmoPV, with 92-94 % identity, and substantially different from all other morbilliviruses. Phylogenetic analysis of the identified Japanese FmoPVs and other morbilliviruses demonstrated a pattern similar to those previously published for the FmoPV viruses isolated in Hong Kong. FmoPV RNA was also detected from formalin-fixed paraffin-embedded (FFPE) kidney tissues of cats with nephritis, with a positive rate of 40 % (4/10). By using nested-set primers based on the FmoPV sequence and RNA from FFPE tissues, we demonstrated the existence of FmoPV infection in Japanese cats and established the method for detection of the FmoPV RNA from kidney tissues prepared for pathology examinations, which is useful for studies on the pathogenicity of the virus.

Feline morbillivirus, a previously undescribed paramyxovirus associated with tubulointerstitial nephritis in domestic cats

We describe the discovery and isolation of a paramyxovirus, feline morbillivirus (FmoPV), from domestic cat (Felis catus). FmoPV RNA was detected in 56 (12.3%) of 457 stray cats (53 urine, four rectal swabs, and one blood sample) by RT-PCR. Complete genome sequencing of three FmoPV strains showed genome sizes of 16,050 bases, the largest among morbilliviruses, because of unusually long 5' trailer sequences of 400 nt. FmoPV possesses identical gene contents (3'-N-P/V/C-M-F-H-L-5') and is phylogenetically clustered with other morbilliviruses. IgG against FmoPV N protein was positive in 49 sera (76.7%) of 56 RT-PCR-positive cats, but 78 (19.4%) of 401 RT-PCR-negative cats (P < 0.0001) by Western blot. FmoPV was isolated from CRFK feline kidney cells, causing cytopathic effects with cell rounding, detachment, lysis, and syncytia formation. FmoPV could also replicate in subsequent passages in primate Vero E6 cells. Infected cell lines exhibited finely granular and diffuse cytoplasmic fluorescence on immunostaining for FmoPV N protein. Electron microscopy showed enveloped virus with typical "herringbone" appearance of helical N in paramyxoviruses. Histological examination of necropsy tissues in two FmoPV-positive cats revealed interstitial inflammatory infiltrate and tubular degeneration/necrosis in kidneys, with decreased cauxin expression in degenerated tubular epithelial cells, compatible with tubulointerstitial nephritis (TIN). Immunohistochemical staining revealed FmoPV N protein-positive renal tubular cells and mononuclear cells in lymph nodes. A case-control study showed the presence of TIN in seven of 12 cats with FmoPV infection, but only two of 15 cats without FmoPV infection (P < 0.05), suggesting an association between FmoPV and TIN.

Disease Education by the B.B.C

ABSTRACT The leopard cat (Prionailurus bengalensis) has been listed as an endangered species under the Wildlife Conservation Act in Taiwan since 2009. In this study, we targeted viral pathogens, included carnivore protoparvovirus 1 (CPPV-1), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), coronavirus (CoV), and canine morbillivirus (CMV), using molecular screening. The spatial and temporal dynamics of the target pathogens were evaluated. Through sequencing and phylogenetic analysis, we aimed to clarify the phylogenetic relationship of isolated viral pathogens between leopard cats and domestic carnivores. Samples from 23 and 29 leopard cats that were live-trapped and found dead, respectively, were collected from Miaoli County from 2015 to 2019 in northwestern Taiwan. CPPV-1 and coronavirus were detected in leopard cats. The prevalence (95% confidence interval) of CPPV-1, and CoV was 63.5% (50.4%–76.6%) and 8.8% (0%–18.4%), respectively. The majority of sequences of each CPPV-1 strain amplified from Taiwanese leopard cats and domestic carnivores were identical. All the amplified CoV sequences from leopard cats were identified as feline coronavirus. The spatial and temporal aggregation of CPPV-1 infection in leopard cats was not determined in the sampling area, which indicated a wide distribution of CPPV-1 in the leopard cat habitat. We consider sympatric domestic carnivores to be the probable primary reservoir for the pathogens identified. We strongly recommend establishing efforts to manage CPPV-1 and FCoV in the leopard cat habitat, with an emphasis on vaccination programs and population control measures for free-roaming dogs and cats. IMPORTANCE The leopard cat (Prionailurus bengalensis) is an endangered species in Taiwan. The effects of infectious diseases on the wildlife population have increasingly been recognized. In this study, we targeted highly pathogenic viral pathogens in wild cat species, included carnivore protoparvovirus 1 (CPPV-1), feline leukemia virus (FeLV), feline immunodeficiency virus (FIV), coronavirus (CoV), and canine morbillivirus (CMV), using molecular screening. Furthermore, we collected the epidemiological and phylogenetic data to understand the spatial and temporal dynamics of the target pathogens in the wild leopard cat population and identified the possible origin of target pathogens. Based on our study, we consider sympatric domestic carnivores to be the probable primary reservoir for the pathogens identified. Our study provides a deeper understanding related to the distribution of target viral pathogens in the wild leopard cats. The information is essential for leopard cat conservation and pathogen management.