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The human respiratory tract is heavily exposed to microorganisms. Viral respiratory tract pathogens, like RSV, influenza and rhinoviruses cause major morbidity and mortality from respiratory tract disease. Furthermore, as viruses have limited means of transmission, viruses that cause pathogenicity in other tissues may be transmitted through the respiratory tract. It is therefore important to chart the human virome in this compartment. We have studied nasopharyngeal aspirate samples submitted to the Karolinska University Laboratory, Stockholm, Sweden from March 2004 to May 2005 for diagnosis of respiratory tract infections. We have used a metagenomic sequencing strategy to characterize viruses, as this provides the most unbiased view of the samples. Virus enrichment followed by 454 sequencing resulted in totally 703,790 reads and 110,931 of these were found to be of viral origin by using an automated classification pipeline. The snapshot of the respiratory tract virome of these 210 patients revealed 39 species and many more strains of viruses. Most of the viral sequences were classified into one of three major families; Paramyxoviridae, Picornaviridae or Orthomyxoviridae. The study also identified one novel type of Rhinovirus C, and identified a number of previously undescribed viral genetic fragments of unknown origin.

Paramyxoviruses can establish persistent infections both in vitro and in vivo , some of which lead to chronic disease. However, little is known about the molecular events that contribute to the establishment of persistent infections by RNA viruses. Using parainfluenza virus type 5 (PIV5) as a model we show that phosphorylation of the P protein, which is a key component of the viral RNA polymerase complex, determines whether or not viral transcription and replication becomes repressed at late times after infection. If the virus becomes repressed, persistence is established, but if not, the infected cells die. We found that single amino acid changes at various positions within the P protein switched the infection phenotype from lytic to persistent. Lytic variants replicated to higher titres in mice than persistent variants and caused greater infiltration of immune cells into infected lungs but were cleared more rapidly. We propose that during the acute phases of viral infection in vivo , lytic variants of PIV5 will be selected but, as the adaptive immune response develops, variants in which viral replication can be repressed will be selected, leading to the establishment of prolonged, persistent infections. We suggest that similar selection processes may operate for other RNA viruses.

Paramyxoviruses are negative-sense, single-stranded RNA viruses that are associated with numerous diseases in humans and animals. J paramyxovirus (JPV) was first isolated from moribund mice ( Mus musculus ) with hemorrhagic lung lesions in Australia in 1972. In 2016, JPV was classified into the newly established genus Jeilongvirus . Novel jeilongviruses are being discovered worldwide in wildlife populations. However, the effects of jeilongvirus infection on host gene expression remains uncharacterized. To address this, cellular RNA from JPV-infected mouse fibroblasts was collected at 2, 4, 8, 12, 16, 24, and 48 hours post-infection (hpi) and were sequenced using single-end 75 base pairs (SE75) sequencing chemistry on an Illumina NextSeq platform. Differentially expressed genes (DEGs) between the virus-infected replicates and mock replicates at each timepoint were identified using the Tophat2-Cufflinks-Cuffdiff protocol. At 2 hpi, 11 DEGs were identified in JPV-infected cells, while 1,837 DEGs were detected at 48 hpi. A GO analysis determined that the genes at the earlier timepoints were involved in interferon responses, while there was a shift towards genes that are involved in antigen processing and presentation processes at the later timepoints. At 48 hpi, a KEGG analysis revealed that many of the DEGs detected were involved in pathways that are important for immune responses. qRT-PCR verified that Rtp4 , Ifit3 , Mx2 , and Stat2 were all upregulated during JPV infection, while G0s2 was downregulated. After JPV infection, the expression of inflammatory and antiviral factors in mouse fibroblasts changes significantly. This study provides crucial insight into the different arms of host immunity that mediate Jeilongvirus infection. Understanding the pathogenic mechanisms of Jeilongvirus will lead to better strategies for the prevention and control of potential diseases that may arise from this group of viruses.

The large virus family Paramyxoviridae includes some of the most significant human and livestock viruses, such as measles-, distemper-, mumps-, parainfluenza-, Newcastle disease-, respiratory syncytial virus and metapneumoviruses. Here we identify an estimated 66 new paramyxoviruses in a worldwide sample of 119 bat and rodent species (9,278 individuals). Major discoveries include evidence of an origin of Hendra- and Nipah virus in Africa, identification of a bat virus conspecific with the human mumps virus, detection of close relatives of respiratory syncytial virus, mouse pneumonia- and canine distemper virus in bats, as well as direct evidence of Sendai virus in rodents. Phylogenetic reconstruction of host associations suggests a predominance of host switches from bats to other mammals and birds. Hypothesis tests in a maximum likelihood framework permit the phylogenetic placement of bats as tentative hosts at ancestral nodes to both the major Paramyxoviridae subfamilies (Paramyxovirinae and Pneumovirinae). Future attempts to predict the emergence of novel paramyxoviruses in humans and livestock will have to rely fundamentally on these data.

Over the past 30 years, research interest in the links between Old World fruit bats (family Pteropodidae) and paramyxoviruses has driven a rapid proliferation of surveillance studies in this system. We performed a systematic review and data synthesis of all published paramyxovirus studies of wild pteropodids. Here, we present an open, static, PRISMA-compliant database called pteroparamyxo, which includes 1,476 records of prevalence or seroprevalence from 118 studies published between 1971 and 2023. Using this dataset, we examined biases in sampling effort, predictors of viral positivity, tissue tropism, and pteropodid–paramyxovirus coevolution. We found significant spatial and taxonomic bias in sampling effort, largely driven by overrepresentation of Pteropus –henipavirus systems; in particular, African bats were undersampled for paramyxoviruses relative to Asian and Oceanian taxa. On the viral side, henipaviruses (specifically Hendra, Nipah, and Cedar viruses) were overrepresented relative to pararubulaviruses. We also identified substantial non-random variability in paramyxovirus prevalence and seroprevalence. Spleens and pooled fecal samples from pteropodids yielded the highest PCR positivity, while samples from Oceania tended to have slightly higher seroprevalence than those from Asia and Africa. Collection year was not a significant predictor of positivity, suggesting limited overall change in paramyxovirus PCR prevalence or seroprevalence over the last several decades. Finally, we found weak evidence of pteropodid–paramyxovirus coevolution, supporting relatively frequent host-switching within this system. Our study highlights critical sampling gaps to address in future surveillance studies and provides preliminary evidence for sample and tissue types to prioritize in field- and museum-based sampling.

Background The discovery of viruses in small mammalian populations, particularly rodents, has expanded the family Paramyxoviridae . The overlap in habitats between rodents and humans increases the risk of zoonotic events, underscoring the importance of active surveillance. Rodent species, such as Apodemus agrarius , are natural hosts for Paramyxoviridae in the Republic of Korea (ROK). However, it is unknown whether Paramyxoviridae is present in Micromys minutus , another common rodent. Method Here, we screened M. minutus collected from the Gangwon Province in the ROK for paramyxoviruses using nested polymerase chain reaction and confirm positive samples by next-generation metagenomic sequencing. Complete paramyxovirus genomes were further characterized by phylogenetic analysis, amino acid similarity, secondary structure, and cophylogeny. Result Overall, 57 of 145 (39.3%) M. minutus kidney samples tested positive for paramyxoviruses. Among them, four whole genome sequences were identified and clustered within the genus Jeilongvirus . One sequence was determined as Samak Micromys paramyxovirus 1 (SMPV-1; 19,911 nucleotides long) and three sequences as Samak Micromys paramyxovirus 2 (SMPV-2; 18,199 nucleotides long). SMPV-1 has a smaller hydrophobic gene and a longer glycoprotein gene than SMPV-2. Cophylogenetic analysis suggests that SMPV-1 evolved through co-divergence, whereas SMPV-2 was inferred to have undergone transfer events. Conclusion These findings highlight the prevalence of paramyxoviruses in the wild and the potential of M. minutus as a natural viral reservoir. The discovery of SMPV-1 and SMPV − 2 also reveals the genetic diversity and evolutionary history of the genus Jeilongvirus in the Paramyxoviridae.

Feline paramyxovirus (FPaV) is a member of the family Paramyxoviridae that has been reported only in Germany and the United Kingdom. We detected FPaV for the first time in Japan by transcriptome sequencing of cat urine samples. We determined the genome structure of FPaV and conducted a phylogenetic analysis. It was found that FPaV belongs to the genus Jeilongvirus and forms a clade with Mount Mabu Lophuromys virus 1 (MMLV-1). FPaV lacks a small hydrophobic (SH) gene that is found in members of the genus Jeilongvirus; however, some jeilongviruses also do not have this gene. These results provide information about the diversity and evolution of paramyxoviruses.

An outbreak of zoonotic diseases is one of the worldwide threats. Bats were reported as important reservoir hosts for many emerging zoonotic diseases. To mitigate the risk, understanding bat virome and their distribution is indispensable. Universal detection methods that can simultaneously identify multiple viruses are some of the most promising approaches. Here, we developed a semicomprehensive detection method integrating group-wide RT-PCR for paramyxoviruses and multiplex next-generation sequencing. The RT-PCR consists of three sets of degenerative primers covering viruses from Paramyxoviridae , including Pneumoviridae , which have now been reclassified into a distinct family. Index nucleotides were added to the primers to enable cost-effective multiplex sequencing, and the length of index was optimized to increase sensitivity. The method was applied to tracheal and rectal swabs from 135 bats captured in Indonesia. A conventional RT-PCR test validated the NGS results. Collectively, seven sequences of novel paramyxovirus-like similar to Pararubulavirus , Orthorubulavirus , and Henipavirus were successfully identified from seven bat samples. Furthermore, sequences between the two different target locations detected by NGS in the virus genomes were verified by RT-PCR. The similarity of the obtained sequences to the known paramyxoviruses sequences was relatively low, ranging from 70.88 to 82.44%. It suggests that the obtained sequences from novel viruses and the zoonotic risk of those novel viruses remain unknown. This cost-affordable, semi-comprehensive, pan-paramyxovirus test can be applied to other samples for viral genome surveillance, and the same strategy can be implemented to other pathogens for zoonosis control.

The bat-borne paramyxovirus, Sosuga virus (SosV), is one of many paramyxoviruses recently identified and classified within the newly established genus Pararubulavirus, family Paramyxoviridae. The envelope surface of SosV presents a receptor-binding protein (RBP), SosV-RBP, which facilitates host-cell attachment and entry. Unlike closely related hemagglutinin neuraminidase RBPs from other genera of the Paramyxoviridae, SosV-RBP and other pararubulavirus RBPs lack many of the stringently conserved residues required for sialic acid recognition and hydrolysis. We determined the crystal structure of the globular head region of SosV-RBP, revealing that while the glycoprotein presents a classical paramyxoviral six-bladed β-propeller fold and structurally classifies in close proximity to paramyxoviral RBPs with hemagglutinin-neuraminidase (HN) functionality, it presents a receptor-binding face incongruent with sialic acid recognition. Hemadsorption and neuraminidase activity analysis confirms the limited capacity of SosV-RBP to interact with sialic acid in vitro and indicates that SosV-RBP undergoes a nonclassical route of host-cell entry. The close overall structural conservation of SosV-RBP with other classical HN RBPs supports a model by which pararubulaviruses only recently diverged from sialic acid binding functionality.

The family includes a number of negative RNA viruses known for their wide host range and significant zoonotic potential. In recent years, there has been a surge in the identification of emerging zoonotic paramyxoviruses, particularly those hosted by bat species, which serve as key reservoirs. Among these, the genera Henipavirus and Pararubulavirus are of particular concern. Henipaviruses, including the highly pathogenic Hendra and Nipah viruses, have caused severe outbreaks with high mortality rates in both humans and animals. In contrast, zoonotic pararubulaviruses such as the Menangle virus typically induce mild symptoms or remain asymptomatic in human hosts. This review summarizes current knowledge on the evolution, ecology, and epidemiology of emerging zoonotic paramyxoviruses, focusing on recently discovered viruses and their potential to cause future epidemics. We explore the molecular mechanisms underlying host-switching events, viral replication strategies, and immune evasion tactics that facilitate interspecies transmission. In addition, we discuss ecological factors influencing virus emergence, including changes in bat populations and habitats and the role of wildlife-human interfaces. We also examine the public health impact of these emerging viruses, underlining the importance of enhanced surveillance, developing improved diagnostic tools, and implementing proactive strategies to prevent potential outbreaks. By providing a comprehensive overview of recent advances and gaps in knowledge, this review aims to inform future research directions and public health policies related to zoonotic paramyxoviruses.