High genetic diversity of paramyxoviruses infecting domestic cats in Western Brazil

Discovery and genetic characterization of novel paramyxoviruses from small mammals in Hubei Province, Central China

Paramyxoviruses are a group of single-stranded, negative-sense RNA viruses, some of which are responsible for acute human disease, including parainfluenza virus, measles virus, Nipah virus and Hendra virus. In recent years, a large number of novel paramyxoviruses, particularly members of the genus Jeilongvirus, have been discovered in wild mammals, suggesting that the diversity of paramyxoviruses may be underestimated. Here we used hemi-nested reverse transcription PCR to obtain 190 paramyxovirus sequences from 969 small mammals in Hubei Province, Central China. These newly identified paramyxoviruses were classified into four clades: genera Jeilongvirus, Morbillivirus, Henipavirus and Narmovirus, with most of them belonging to the genus Jeilongvirus. Using Illumina sequencing and Sanger sequencing, we successfully recovered six near-full-length genomes with different genomic organizations, revealing the more complex genome content of paramyxoviruses. Co-divergence analysis of jeilongviruses and their known hosts indicates that host-switching occurred more frequently in the evolutionary histories of the genus Jeilongvirus. Together, our findings demonstrate the high prevalence of paramyxoviruses in small mammals, especially jeilongviruses, and highlight the diversity of paramyxoviruses and their genome content, as well as the evolution of jeilongviruses.

Tailam paramyxovirus C protein inhibits viral replication

Jeilongviruses are emerging single-stranded negative-sense RNA viruses in the Paramyxoviridae family. Tailam paramyxovirus (TlmPV) is a Jeilongvirus that was identified in 2011. Very little is known about the mechanisms that regulate viral replication in these newly emerging viruses. Among the non-structural viral proteins of TlmPV, the C protein is predicted to be translated from an open reading frame within the phosphoprotein gene through alternative translation initiation. Though the regulatory roles of C proteins in virus replication of other paramyxoviruses have been reported before, the function of the TlmPV C protein and the relevant molecular mechanisms have not been reported. Here, we show that the C protein is expressed in TlmPV-infected cells and negatively modulates viral RNA replication. The TlmPV C protein interacts with the P protein, negatively impacting the interaction between N and P, resulting in inhibition of viral RNA replication. Deletion mutagenesis studies indicate that the 50 amino-terminal amino acid residues of the C protein are dispensable for its inhibition of virus RNA replication and interaction with the P protein.IMPORTANCETailam paramyxovirus (TlmPV) is a newly identified paramyxovirus belonging to the Jeilongvirus genus, of which little is known. In this work, we confirmed the expression of the C protein in TlmPV-infected cells, assessed its function, and defined a potential mechanism of action. This is the first time that the existence of a Jeilongvirus C protein has been confirmed and its role in viral replication has been reported.

Feline Morbillivirus: Clinical Relevance of a Widespread Endemic Viral Infection of Cats

Feline morbillivirus (FeMV) was first isolated in 2012 from stray cats in Hong Kong. It has been found in association with tubulointerstitial nephritis (TIN), the most common cause of feline chronic kidney disease (CKD). However, viral host spectrum and virus tropism go beyond the domestic cat and kidney tissues. The viral genetic diversity of FeMV is extensive, but it is not known if this is clinically relevant. Urine and kidney tissues have been widely tested in attempts to confirm associations between FeMV infection and renal disease, but samples from both healthy and sick cats can test positive and some cross-sectional studies have not found associations between FeMV infection and CKD. There is also evidence for acute kidney injury following infection with FeMV. The results of prevalence studies differ greatly depending on the population tested and methodologies used for detection, but worldwide distribution of FeMV has been shown. Experimental studies have confirmed previous field observations that higher viral loads are present in the urine compared to other tissues, and renal TIN lesions associated with FeMV antigen have been demonstrated, alongside virus lymphotropism and viraemia-associated lymphopenia. Longitudinal field studies have revealed persistent viral shedding in urine, although infection can be cleared spontaneously.

Genetic Diversity and Evolution of Viruses Infecting Felis catus: A Global Perspective

Cats harbor many important viral pathogens, and the knowledge of their diversity has been greatly expanded thanks to increasingly popular molecular sequencing techniques. While the diversity is mostly described in numerous regionally defined studies, there lacks a global overview of the diversity for the majority of cat viruses, and therefore our understanding of the evolution and epidemiology of these viruses was generally inadequate. In this study, we analyzed 12,377 genetic sequences from 25 cat virus species and conducted comprehensive phylodynamic analyses. It revealed, for the first time, the global diversity for all cat viruses known to date, taking into account highly virulent strains and vaccine strains. From there, we further characterized and compared the geographic expansion patterns, temporal dynamics and recombination frequencies of these viruses. While respiratory pathogens such as feline calicivirus showed some degree of geographical panmixes, the other viral species are more geographically defined. Furthermore, recombination rates were much higher in feline parvovirus, feline coronavirus, feline calicivirus and feline foamy virus than the other feline virus species. Collectively, our findings deepen the understanding of the evolutionary and epidemiological features of cat viruses, which in turn provide important insight into the prevention and control of cat pathogens.

Genetic Diversity and Expanded Host Range of J Paramyxovirus Detected in Wild Small Mammals in China

J paramyxovirus (JPV) is a rodent-borne Jeilongvirus isolated from moribund mice (Mus musculus) with hemorrhagic lung lesions trapped in the 1972 in northern Queensland, Australia. The JPV antibodies have been detected in wild mice, wild rats, pigs, and human populations in Australia. Here, by next-generation sequencing (NGS), we detected JPV from M. musculus in Shandong Province of China. Molecular detection of JPV was performed to survey to survey the infection among 66 species of wild small mammals collected from six eco-climate regions in China by applying JPV specific RT-PCR and sequencing. Altogether, 21 out of 3070 (0.68%) wild small mammals of four species were positive for JPV, including 5.26% (1/19) of Microtus fortis, 3.76% (17/452) of M. musculus, 1.67% (1/60) of Apodemus peninsulae, and 0.48% (2/421) of Apodemus agrarius, which captured three eco-climate regions of China (northeastern China, northern China, and Inner Mongolia-Xinjiang). Sequence analysis revealed the currently identified JPV was clustered with other 14 Jeilongvirus members, and shared 80.2% and 89.2% identity with Australia's JPV partial RNA polymerase (L) and glycoprotein (G) genes, respectively. Phylogenetic analysis demonstrated the separation of three lineages of the current JPV sequences. Our results show three new hosts (A. agrarius, A. peninsulae, and M. fortis) for JPV, most of which were widely distributed in China, and highlight the potential zoonotic transmission of JPV in humans. The detection of JPV in wild small mammals in China broaden the viral diversity, geographical distribution, and reservoir types of JPV. Future studies should prioritize determining the epidemiological characteristics of JPV, so that potential risks can be mitigated.

Feline Morbillivirus in Southern Italy: Epidemiology, Clinico-Pathological Features and Phylogenetic Analysis in Cats

Feline morbillivirus (FeMV) was isolated for the first time in 2012 with an association with chronic kidney disease (CKD) suggested. This study aimed at investigating in cats from southern Italy FeMV prevalence and risk factors for exposure to FeMV, including the relationship with CKD; sequencing amplicons and analyzing phylogeny of PCR positive samples. Blood serum, K₃EDTA blood and urine samples from 223 cats were investigated. Ten carcasses were also evaluated. FeMV RNA was detected in 2.4% (5/211) blood and 16.1% (36/223) urine samples. One carcass tested positive by qPCR_FeMV from kidney, urinary bladder, and submandibular lymph nodes. Antibodies against FeMV were detected in 14.5% (28/193) cats. We followed up 27 cats (13 FeMV positive cats) and documented in some cases urine shedding after up to 360 days. Older and foundling cats and cats living in rescue catteries, were more frequently infected with FeMV. A significant correlation between FeMV and higher serum creatinine values or low urine specific gravity was found. FeMV positivity was significantly associated with retroviral infection, and the presence of some clinical signs apart from CKD clinicopathological markers. Our study highlights the possibility of a link between FeMV exposure and CKD and a general impairment of feline health.

Seroprevalence of Infection with Feline Morbilliviruses Is Associated with FLUTD and Increased Blood Creatinine Concentrations in Domestic Cats

Feline morbilliviruses (FeMV) are fairly newly discovered paramyxoviruses found in cats. The first description indicated an association with widely distributed chronic kidney disease (CKD) in the host species. In various studies, a global prevalence and a further genotype, designated FeMV-2, and the involvement of other organ systems in infected individuals were shown. Using an immunofluorescence assay, we detected an overall seroprevalence of FeMV in almost half of the cats investigated (n = 380), with a significantly increased proportion in younger animals. In comparison to European Shorthair cats, the rate of seropositivity is higher in pedigree cats. Regardless of the breed, FeMV infection was associated with increased blood creatinine concentrations, suggesting an association with CKD. Further analysis indicated that this association was the strongest in animals having high IFA titers against FeMV-2. In addition, a significant association between FeMV-positive status and the prevalence of feline lower urinary tract disease (FLUTD, or idiopathic cystitis) was detected. This association was dominated by cats having antibodies against FeMV-1 only. To further evaluate the positive correlation between FeMV seroprevalence and CKD as well as FLUTD, consideration of additional clinical characteristics and laboratory parameters is warranted, and controlled infection studies with both FeMV genotypes are necessary. Clinicians should, however, be aware of a possible link between renal and lower urinary tract disease and FeMV infections.