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.

Geographical Expansion of Avian Metapneumovirus Subtype B: First Detection and Molecular Characterization of Avian Metapneumovirus Subtype B in US Poultry.

Avian metapneumovirus (aMPV), classified within the Pneumoviridae family, wreaks havoc on poultry health. It typically causes upper respiratory tract and reproductive tract infections, mainly in turkeys, chickens, and ducks. Four subtypes of AMPV (A, B, C, D) and two unclassified subtypes have been identified, of which subtypes A and B are widely distributed across the world. In January 2024, an outbreak of severe respiratory disease occurred on turkey and chicken farms across different states in the US. Metagenomics sequencing of selected tissue and swab samples confirmed the presence of aMPV subtype B. Subsequently, all samples were screened using an aMPV subtype A and B multiplex real-time RT-PCR kit. Of the 221 farms, 124 (56%) were found to be positive for aMPV-B. All samples were negative for subtype A. Six whole genomes were assembled, five from turkeys and one from chickens; all six assembled genomes showed 99.29 to 99.98% nucleotide identity, indicating a clonal expansion event for aMPV-B within the country. In addition, all six sequences showed 97.74 to 98.58% nucleotide identity with previously reported subtype B sequences, e.g., VCO3/60616, Hungary/657/4, and BR/1890/E1/19. In comparison to these two reference strains, the study sequences showed unique 49-62 amino acid changes across the genome, with maximum changes in glycoprotein (G). One unique AA change from T (Threonine) to I (Isoleucine) at position 153 in G protein was reported only in the chicken aMPV sequence, which differentiated it from turkey sequences. The twelve unique AA changes along with change in polarity of the G protein may indicate that these unique changes played a role in the adaptation of this virus in the US poultry. This is the first documented report of aMPV subtype B in US poultry, highlighting the need for further investigations into its genotypic characterization, pathogenesis, and evolutionary dynamics.

Sosuga Virus Detected in Egyptian Rousette Bats (Rousettus aegyptiacus) in Sierra Leone.

Sosuga virus (SOSV), a rare human pathogenic paramyxovirus, was first discovered in 2012 when a person became ill after working in South Sudan and Uganda. During an ecological investigation, several species of bats were sampled and tested for SOSV RNA and only one species, the Egyptian rousette bat (ERBs; Rousettus aegyptiacus), tested positive. Since that time, multiple other species have been sampled and ERBs in Uganda have continued to be the only species of bat positive for SOSV infection. Subsequent studies of ERBs with SOSV demonstrated that ERBs are a competent host for SOSV and shed this infectious virus while exhibiting only minor infection-associated pathology. Following the 2014 Ebola outbreak in West Africa, surveillance efforts focused on discovering reservoirs for zoonotic pathogens resulted in the capture and testing of many bat species. Here, SOSV RNA was detected by qRT-PCR only in ERBs captured in the Moyamba District of Sierra Leone in the central region of the country. These findings represent a substantial range extension from East Africa to West Africa for SOSV, suggesting that this paramyxovirus may occur in ERB populations throughout its sub-Saharan African range.

SQSTM1 downregulates avian metapneumovirus subgroup C replication via mediating selective autophagic degradation of viral M2-2 protein.

Avian metapneumovirus subgroup C (aMPV/C), an important pathogen causing acute respiratory infection in chickens and turkeys, contributes to substantial economic losses in the poultry industry worldwide. aMPV/C has been reported to induce autophagy, which is beneficial to virus replication. Sequestosome 1 (SQSTM1/P62), a selective autophagic receptor, plays a crucial role in viral replication by clearing ubiquitinated proteins. However, the relationship between SQSTM1-mediated selective autophagy and aMPV/C replication is unclear. In this study, we found that the expression of SQSTM1 negatively regulates aMPV/C replication by reducing viral protein expression and viral titers. Further studies revealed that the interaction between SQSTM1 and aMPV/C M2-2 protein is mediated via the Phox and Bem1 (PB1) domain of the former, which recognizes a ubiquitinated lysine at position 67 of the M2-2 protein, and finally degrades M2-2 via SQSTM1-mediated selective autophagy. Collectively, our results reveal that SQSTM1 degrades M2-2 via a process of selective autophagy to suppress aMPV/C replication, thereby providing novel insights for the prevention and control of aMPV/C infection.IMPORTANCEThe selective autophagy plays an important role in virus replication. As an emerging pathogen of avian respiratory virus, clarification of the effect of SQSTM1, a selective autophagic receptor, on aMPV/C replication in host cells enables us to better understand the viral pathogenesis. Previous study showed that aMPV/C infection reduced the SQSTM1 expression accompanied by virus proliferation, but the specific regulatory mechanism between them was still unclear. In this study, we demonstrated for the first time that SQSTM1 recognizes the 67th amino acid of M2-2 protein by the interaction between them, followed by M2-2 degradation via the SQSTM1-mediated selective autophagy, and finally inhibits aMPV/C replication. This information supplies the mechanism by which SQSTM1 negatively regulates viral replication, and provides new insights for preventing and controlling aMPV/C infection.

Bovine parainfluenza type 3 virus induces incomplete autophagy to promote viral replication by activated beclin1 in vitro.

Bovine Parainfluenza virus Type 3 (BPIV3) is one of the most important pathogens in cattle, capable of causing severe respiratory symptoms. Numerous studies have shown that autophagy plays a diverse role in the infection process of various pathogens. The influence of autophagy machinery on BPIV3 infection has not yet been confirmed. In the present study, we initially demonstrated that the expression of LC3 was significantly increased and exhibited a notable increase in double or single-membrane vesicles under a transmission electron microscope during BPIV3 infection. These observations unequivocally establish the induction of steady-state autophagy in vitro consequent to BPIV3 infection. Furthermore, quantification of autophagic flux substantiates the induction of an incomplete autophagic process during BPIV3 infection. Additionally, through targeted interventions, we demonstrate the regulatory impact of pharmacological agents influencing autophagy and RNA interference targeting an autophagy-associated protein on viral replication. Intriguingly, our data revealed that BPIV3 infection enhanced the phosphorylation of rapamycin kinase (mTOR). This result demonstrated that mTOR does not operate as a counteractive regulator of BPIV3-induced autophagy. Instead, we discern an augmentation in the expression of Beclin1, a key autophagy initiator, which complexes with Vps34, constituting a Class III phosphatidylinositol 3-kinase. This phenomenon serves as a hallmark in the inaugural phase of autophagy initiation during BPIV3 infection. Collectively, these discernments underscore that BPIV3 infection actively stimulates autophagy, thereby enhancing viral replication through the activation of Beclin1, independently of the mTOR signaling pathway. This nuanced comprehension significantly contributes to unraveling the intricate molecular mechanisms governing BPIV3-induced autophagy.

Research Note: Evaluation of the cross protective efficacy of a subtype B aMPV vaccine against virulent subtype A aMPV by different administration routes.

Avian metapneumovirus (aMPV) causes respiratory and reproductive diseases in birds, including chickens. In the chicken industry, live vaccines against aMPV subtypes A and B, which are the major aMPV subtypes, are widely used to control disease caused by aMPV. In this study, we evaluated the cross protective efficacy of a live aMPV subtype B vaccine administered via 3 different routes (nasal, spray, and oral) against virulent aMPV subtype A in chickens. At 3 wk after vaccination of 1-wk-old specific-pathogen-free chickens, we measured the serological responses. On the same day, we challenged the birds with aMPV subtype A. Protection was evaluated by viral gene detection and histopathological examination at 3 and 5 days postchallenge. Although there were differences in the serological responses according to administration route, all vaccinated birds showed complete protection at 5 days postchallenge. Regardless of administration route, genome of challenge virus was not detected in vaccinated group, and there were significant differences between vaccinated birds and control group. Overall, our results demonstrated that a subtype B aMPV vaccine can provide cross protection against virulent subtype A aMPV in chickens.

Serological survey of avian metapneumovirus in vaccinated and unvaccinated broiler chickens in Hong Kong.

In chickens, avian metapneumovirus (aMPV) causes the swollen head syndrome, a respiratory disease often associated with a reduction in egg production. The virus' epidemiology in East and Southeast Asia is poorly understood. An aMPV serological survey was conducted on broiler chicken farms of Hong Kong SAR to assess the seroprevalence of aMPV in unvaccinated batches and the serological status of vaccinated batches. Blood samples were collected from 53-93-day-old chickens in 24 chicken farms of Hong Kong SAR and sera were tested for aMPV antibodies by ELISA. Seroprevalence in aMPV unvaccinated birds was 80.6% (95% confidence interval (CI): 78.9-82.2) with a high variation between batches. Batch-level seroprevalence was not significantly different between birds hatched during the rainy season (74.3%, 95% CI: 64.0-84.5) and the ones hatched during the dry season (88.7%, 95% CI: 80.1-97.3, p = 0.5). The high seroprevalence and high antibody titers that are reported in this study indicate repeated exposure of broiler chickens to aMPV in Hong Kong SAR poultry farms. Based on these results, we recommend improving the surveillance of respiratory pathogens and applying appropriate prophylactic measures against aMPV such as vaccination.

Pathogenic infection characteristics and risk factors for bovine respiratory disease complex based on the detection of lung pathogens in dead cattle in Northeast China.

Bovine respiratory disease complex (BRDC) involves multiple pathogens, shows diverse lung lesions, and is a major concern in calves. Pathogens from 160 lung samples of dead cattle from 81 cattle farms in Northeast China from 2016 to 2021 were collected to characterize the molecular epidemiology and risk factors of BRDC and to assess the major pathogens involved in bovine suppurative or caseous necrotizing pneumonia. The BRDC was diagnosed by autopsy, pathogen isolation, PCR, or reverse transcription-PCR detection, and gene sequencing. More than 18 species of pathogens, including 491 strains of respiratory pathogens, were detected. The positivity rate of bacteria in the 160 lung samples was 31.77%, including Trueperella pyogenes (9.37%), Pasteurella multocida (8.35%), Histophilus somni (4.48%), Mannheimia haemolytica (2.44%), and other bacteria (7.13%). The positivity rate of Mycoplasma spp. was 38.9%, including M. bovis (7.74%), M. dispar (11.61%), M. bovirhinis (7.94%), M. alkalescens (6.11%), M. arginini (0.81%), and undetermined species (4.68%). Six species of viruses were detected with a positivity rate of 29.33%, including bovine herpesvirus-1 (BoHV-1; 13.25%), bovine respiratory syncytial virus (BRSV; 5.50%), bovine viral diarrhea virus (BVDV; 4.89%), bovine parainfluenza virus type-3 (BPIV-3; 4.28%), bovine parainfluenza virus type-5 (1.22%), and bovine coronavirus (2.24%). Mixed infections among bacteria (73.75%), viruses (50%), and M. bovis (23.75%) were the major features of BRDC in these cattle herds. The risk analysis for multi-pathogen co-infection indicated that BoHV-1 and H. somni; BVDV and M. bovis, P. multocida, T. pyogenes, or Mann. haemolytica; BPIV-3 and M. bovis; BRSV and M. bovis, P. multocida, or T. pyogenes; P. multocida and T. pyogenes; and M. bovis and T. pyogenes or H. somni showed co-infection trends. A survey on molecular epidemiology indicated that the occurrence rate of currently prevalent pathogens in BRDC was 46.15% (6/13) for BoHV-1.2b and 53.85% (7/13) for BoHV-1.2c, 53.3% (8/15) for BVDV-1b and 46.7% (7/15) for BVDV-1d, 29.41% (5/17) for BPIV-3a and 70.59% (12/17) for BPIV-3c, 100% (2/2) for BRSV gene subgroup IX, 91.67% (33/36) for P. multocida serotype A, and 8.33% (3/36) for P. multocida serotype D. Our research discovered new subgenotypes for BoHV-1.2c, BRSV gene subgroup IX, and P. multocida serotype D in China's cattle herds. In the BRDC cases, bovine suppurative or caseous necrotizing pneumonia was highly related to BVDV [odds ratio (OR) = 4.18; 95% confidence interval (95% CI): 1.6-10.7], M. bovis (OR = 2.35; 95% CI: 1.1-4.9), H. somni (OR = 8.2; 95% CI: 2.6-25.5), and T. pyogenes (OR = 13.92; 95% CI: 5.8-33.3). The risk factor analysis found that dairy calves <3 mo and beef calves >3 mo (OR = 5.39; 95% CI: 2.7-10.7) were more susceptible to BRDC. Beef cattle were more susceptible to bovine suppurative or caseous necrotizing pneumonia than dairy cattle (OR = 2.32; 95% CI: 1.2-4.4). These epidemiological data and the new pathogen subgenotypes will be helpful in formulating strategies of control and prevention, developing new vaccines, improving clinical differential diagnosis by necropsy, predicting the most likely pathogen, and justifying antimicrobial use.

Phylogenetic and phylodynamic analyses of subtype-B metapneumovirus from chickens in Tunisia.

Swollen Head Syndrome (SHS) is an economically important viral disease of chickens caused by avian metapneumovirus (aMPV). The virus comprises 6 different subtypes (A,B,C,D, New-1 and New-2). To date, no information was available on the presence of the virus in Tunisian poultry. The present work aims to detect the presence of (aMPV) in broiler chicken in Tunisia, then to characterise the isolates in order to determine their subtype and to estimate their geographic origin of introduction. A total of 289 samples were collected, aMPV detection was detected by real time RT-PCR and molecular characterization was warried out by Sanger sequencing on the glycoprotein (G) gene. Phylogenetic analysis was carried out using Beast 2 software. Out of the 289 samples, 21 were revealed positive to aMPV. Only 2 isolates have been confirmed by sequencing analysis ; one isolate sampled in 2015 and another in 2019. Based on the partial G gene sequence, analysis of these 2 Tunisian isolates showed that they belong to subtype B. The isolate sampled in 2015, appeared to be phylogenetically related to derived vaccine strain. However, the one sampled in 2019 appeared to be a field strain. Phylodynamic analysis provided evidence that this field strain derived from a Spanish strain and probably the virus has been introduced from Spain to North Africa back in 2016. This study is the first that highlighted the circulation of (aMPV) in Tunisia. It is possible that aMPV has been circulating in Tunisia and neighboring countries without being detected. Also, multiple strains could be present and therefore multiple introductions have happened. Through this study, we shed the light on the importance of reinforcing farms biosecurity as well as virological surveillance.

Characterization of avain metapneumovirus subgroup C isolated from chickens in Beijing, China.

Avian metapneumovirus (aMPV) is an important causative agent that causes acute respiratory disease and egg-dropping in chickens and turkeys. Here, we characterized an aMPV subgroup C (aMPV/C) from 320-day-old broiler breeder chickens with severe respiratory diseases in Beijing, China, as evidenced by RT-PCR typing and confirmation of the nucleoprotein (N) gene sequence. The N gene sequence of the aMPV/C strain (designated BJ17) exhibited no deletions or insertions and possessed 94.6% to 99.6% identity to those of published aMPV/C isolates. The phylogenetic tree of the nucleotide sequences constructed using the neighbor-joining clustering method showed that the BJ17 strain formed one cluster with other aMPV/C viruses and formed one subcluster with published Chinese aMPV/C isolates regardless of Muscovy duck or chicken origins. Comparative analysis of the N proteins showed that a unique amino acid residue D at position 110 might be associated with regional distribution due to its occurrence in all the Chinese aMPV/C isolates only. Strain BJ17 was successfully isolated by cultured Vero cell passage and further inoculated in 3-wk-old specific-pathogen-free chickens for the examination of pathogenicity. Animal experimental results showed that BJ17-inoculated chickens had severe respiratory diseases and inflammatory lesions, as demonstrated by pathological changes and aMPV antigen in the nasal turbinate, tracheae, and lung tissues. These results enrich the available information regarding the epidemiology and pathogenicity of aMPV/C in chickens, which may facilitate the development of effective measures against aMPV/C infection in China.

Disentangling the role of wild birds in avian metapneumovirus (aMPV) epidemiology: A systematic review and meta-analysis.

Given the avian metapneumovirus (aMPV) disease burden in poultry worldwide and the evidence of a possible role played by wild birds in the virus epidemiology, the present study summarizes aMPV serological and molecular data on free-ranging avifauna available in the literature by conducting a systematic review and meta-analysis. A computerized literature research was performed on PubMed, Scopus, CAB Direct and Web of Science to identify relevant publications across the period 1990-2021, along with the screening of reference lists. A random-effect model was applied to calculate pooled prevalence estimates with 95% confidence intervals. The inconsistency index statistic (I2 ) was applied to assess between-study heterogeneity. Subgroup analyses for molecular studies only were performed according to geographical area of samplings, taxonomic order, genus and migration patterns of the birds surveyed. A total of 11 publications on molecular surveys and 6 on serological ones were retained for analysis. The pooled molecular prevalence was 6% (95% CI: 1-13%) and a high between-study heterogeneity was detected (I2  = 96%, p < .01). Moderator analyses showed statistically significant differences according to geographical area studied, taxonomic order and genus. Concerning serological prevalence, a pooled estimate of 14% (95% CI: 1-39%), along with a high between-study heterogeneity, was obtained (I2  = 98%, p < .01). Moderator analysis was not performed due to the scarcity of eligible serological studies included. Overall, molecular and serological evidence suggests that some wild bird taxa could play a role in aMPV epidemiology. Particularly, wild ducks, geese, gulls and pheasants, according to scientific contributions hereby considered, proved to be susceptible to aMPV, and due to host ecology, may act as a viral carrier or reservoir. Further surveys of wild birds are encouraged for a better comprehension of the poultry/wild bird interface in aMPV epidemiology and for better characterizing the virus host breadth.

Molecular characterization of avian metapneumovirus subtype C detected in wild mallards (Anas platyrhynchos) in The Netherlands.

Avian metapneumovirus (AMPV) represents a long-term threat to the poultry industry due to its etiological role in the induction of acute respiratory disease and/or egg drop syndrome in domestic turkeys, chickens, and ducks. Although this disease is commonly referred to as turkey rhinotracheitis, the host range of AMPV encompasses many avian species. We have screened 1323 oropharyngeal- and cloacal swab samples obtained from wild mallards in the Netherlands from 2017 to 2019 by RT-PCR using a degenerate primer pair to detect all members of the Paramyxoviridae and Pneumoviridae or an avian metapneumovirus subtype C (AMPV-C)-specific RT-qPCR assay. We identified a total of seven cases of AMPV-C infections in wild, healthy mallards (Anas platyrhynchos), of which two AMPV-C positive samples were further processed using next-generation sequencing. Phylogenetic analysis of the two complete genomes showed that the newly identified AMPV-C strains share closest sequence identity (97%) with Eurasian lineage AMPV-C strains identified in Muscovy ducks in China that presented with severe respiratory disease and egg production loss in 2011. Further analysis of G protein amino acid sequences showed a high degree of variability between the newly identified AMPV-C variants. PONDR scoring of the G protein has revealed the ectodomain of AMPV-C to be partitioned into a long intrinsically disordered and short ordered region, giving insights into AMPV G protein structural biology. In summary, we provide the first report of full-length AMPV-C genome sequences derived from wild birds in Europe. This emphasizes the need for further surveillance efforts to better characterize the host range, epidemiologic distribution, and pathogenicity of AMPV-C to determine the risk posed by cross-species jumps from wildfowl to domesticated avian species.

Divergent Viruses Discovered in Swine Alter the Understanding of Evolutionary History and Genetic Diversity of the Respirovirus Genus and Related Porcine Parainfluenza Viruses.

Paramyxoviridae is a rapidly growing family of viruses, whose potential for cross-species transmission makes it difficult to predict the harm of newly emerging viruses to humans and animals. To better understand their diversity, evolutionary history, and co-evolution with their hosts, we analyzed a collection of porcine parainfluenza virus (PPIV) genomes to reconstruct the species classification basis and evolutionary history of the Respirovirus genus. We sequenced 17 complete genomes of porcine respirovirus 1 (also known as porcine parainfluenza virus 1; PPIV-1), thereby nearly tripling the number of currently available PPIV-1 genomes. We found that PPIV-1 was widely prevalent in China with two divergent lineages, PPIV-1a and PPIV-1b. We further provided evidence that a new species, porcine parainfluenza virus 2 (PPIV-2), had recently emerged in China. Our results pointed to a need for revising the current species demarcation criteria of the Respirovirus genus. In addition, we used PPIV-1 as an example to explore recombination and diversity of the Respirovirus genus. Interestingly, we only detected heterosubtypic recombination events between PPIV-1a and PPIV-1b with no intrasubtypic recombination events. The recombination hotspots highlighted a diverse geography-dependent genome structure of paramyxovirus infecting swine in China. Furthermore, we found no evidence of co-evolution between respirovirus and its host, indicating frequent cross-species transmission. In summary, our analyses showed that swine can be infected with a broad range of respiroviruses and recombination may serve as an important evolutionary mechanism for the Respirovirus genus' greater diversity in genome structure than previously anticipated. IMPORTANCE Livestock have emerged as critically underrecognized sources of paramyxovirus diversity, including pigs serving as the source of Nipah virus (NiV) and swine parainfluenza virus type 3, and goats and bovines harboring highly divergent viral lineages. Here, we identified a new species of Respirovirus genus named PPIV-2 in swine and proposed to revise the species demarcation criteria of the Respirovirus genus. We found heterosubtypic recombination events and high genetic diversity in PPIV-1. Further, we showed that genetic recombination may have occurred in the Respirovirus genus which may be associated with host range expansion. The continued expansion of Respirovirus genus diversity in livestock with relatively high human contact rates requires enhanced surveillance and ongoing evaluation of emerging cross-species transmission threats.

Zoonotic Origins of Human Metapneumovirus: A Journey from Birds to Humans.

Metapneumoviruses, members of the family Pneumoviridae, have been identified in birds (avian metapneumoviruses; AMPV's) and humans (human metapneumoviruses; HMPV's). AMPV and HMPV are closely related viruses with a similar genomic organization and cause respiratory tract illnesses in birds and humans, respectively. AMPV can be classified into four subgroups, A-D, and is the etiological agent of turkey rhinotracheitis and swollen head syndrome in chickens. Epidemiological studies have indicated that AMPV also circulates in wild bird species which may act as reservoir hosts for novel subtypes. HMPV was first discovered in 2001, but retrospective studies have shown that HMPV has been circulating in humans for at least 50 years. AMPV subgroup C is more closely related to HMPV than to any other AMPV subgroup, suggesting that HMPV has evolved from AMPV-C following zoonotic transfer. In this review, we present a historical perspective on the discovery of metapneumoviruses and discuss the host tropism, pathogenicity, and molecular characteristics of the different AMPV and HMPV subgroups to provide increased focus on the necessity to better understand the evolutionary pathways through which HMPV emerged as a seasonal endemic human respiratory virus.

Detection of porcine parainfluenza virus type-1 antibody in swine serum using whole-virus ELISA, indirect fluorescence antibody and virus neutralizing assays.

BACKGROUND: Porcine parainfluenza virus 1 (PPIV-1) is a respiratory virus in the family Paramyxoviridae and genus Respirovirus. It is closely related to bovine parainfluenza virus 3, human parainfluenza virus 1, and Sendai virus. Recent reports suggest PPIV-1 is widespread in swine herds in the United States and abroad. However, seroprevalence studies and the ability to evaluate cross neutralization between heterologous strains is not possible without validated antibody assays. This study describes the development of an indirect fluorescence antibody (IFA) assay, a whole virus enzyme-linked immunosorbent assay (wv-ELISA) and a serum virus neutralization (SVN) assay for the detection of PPIV-1 antibodies using 521 serum samples collected from three longitudinal studies and two different challenge strains in swine. RESULTS: The area under the curve (AUC) of the wv-ELISA (95% CI, 0.93-0.98) was significantly higher (p = 0.03) compared to the IFA (95% CI, 0.90-0.96). However, no significant difference was observed between the IFA and wv-ELISA when compared to the SVN (95% CI, 0.92-0.97). All three assays demonstrated relatively uniform results at a 99% true negative rate, with only 11 disagreements observed between the IFA, wv-ELISA and SVN. CONCLUSIONS: All three serology assays detected PPIV-1 antibody in swine serum of known status that was collected from experimental studies. The SVN detected seroconversion earlier compared to the IFA and the wv-ELISA. Both the wv-ELISA and the SVN had similar diagnostic performance, while the IFA was not as sensitive as the wv-ELISA. All three assays are considered valid for routine diagnostic use. These assays will be important for future studies to screen seronegative swine for research, determine PPIV-1 seroprevalence, and to evaluate vaccine efficacy against PPIV-1 under experimental and field conditions.

Avian metapneumovirus subtype B vaccination in commercial broiler chicks: heterologous protection and selected host transcription responses to subtype A or B challenge.

Avian metapneumovirus (aMPV) causes respiratory disease and drops in egg production in chickens, and is routinely controlled by vaccination. However, the host's immune response to virulent challenge in vaccinated or unvaccinated broiler chickens is poorly characterized. We show that subtype B vaccination offers heterologous (subtype A challenge) and homologous (subtype B challenge) protection. Subtype B challenge caused significantly greater humoral antibody titres in vaccinated and unvaccinated chickens. In turbinate and lung tissues of unvaccinated-challenged chickens, IgA and IgY mRNA transcription was significantly up-regulated after subtype B challenge compared to subtype A. Cellular immunity (CD8-α and CD8-ß) gene transcripts were significantly up-regulated during early and later stages of infection from subtype B or subtype A, respectively. Immune gene transcriptional responses (IL-1ß, IL-6 and IL-18) were significantly up-regulated after challenge. Gene transcription results showed that mRNA expression levels of CD8-α, CD8-ß, TLR3 and IL-6, particularly in turbinate and trachea tissues, are useful parameters to include in future aMPV vaccination-challenge studies.

Evolution and Diversity of Bat and Rodent Paramyxoviruses from North America.

Paramyxoviruses are a diverse group of negative-sense, single-stranded RNA viruses of which several species cause significant mortality and morbidity. In recent years the collection of paramyxovirus sequences detected in wild mammals has substantially grown; however, little is known about paramyxovirus diversity in North American mammals. To better understand natural paramyxovirus diversity, host range, and host specificity, we sought to comprehensively characterize paramyxoviruses across a range of diverse cooccurring wild small mammals in southern Arizona. We used highly degenerate primers to screen fecal and urine samples and obtained a total of 55 paramyxovirus sequences from 12 rodent species and 6 bat species. We also performed Illumina transcriptome sequencing (RNA-seq) and de novo assembly on 14 of the positive samples to recover a total of 5 near-full-length viral genomes. We show there are at least two clades of rodent-borne paramyxoviruses in Arizona, while bat-associated paramyxoviruses formed a putative single clade. Using structural homology modeling of the viral attachment protein, we infer that three of the five novel viruses likely bind sialic acid in a manner similar to other respiroviruses, while the other two viruses from heteromyid rodents likely bind a novel host receptor. We find no evidence for cross-species transmission, even among closely related sympatric host species. Taken together, these data suggest paramyxoviruses are a common viral infection in some bat and rodent species present in North America and illuminate the evolution of these viruses. IMPORTANCE There are a number of viral lineages that are potential zoonotic threats to humans. One of these, paramyxoviruses have jumped into humans multiple times from wild and domestic animals. We conducted one of the largest viral surveys of wild mammals in the United States to better understand paramyxovirus diversity and evolution.

Paramyxoviruses in rodents: A review.

Paramyxoviruses have been shown to infect a wide range of hosts, including rodents, and humans. Several novel murine paramyxoviruses have been discovered in the last several decades. Although these viruses are unclassified, they are recognized as Beilong virus, Mojiang virus (MojV), and Tailam virus in rats, Jeilongvirus, Nariva, Paju Apodemus paramyxovirus-1 and -2 in mice, and Pentlands paramyxovirus-1, -2, and -3 in squirrels. These paramyxoviruses were reported mainly in China and a few other countries like Australia, the Republic of Korea, Trinidad, and France. In June 2012, it becomes a great concern in China whereby, three miners were reported dead potentially caused by a novel zoonotic MojV, a henipa-like virus isolated from tissue samples of rats from the same cave. Rats are considered to be natural hosts for the MojV from the literature research. The classified paramyxovirus, Sendai virus in rodents is also reviewed. Paramyxoviruses infection in rodents leads to respiratory distress such as necrotizing rhinitis, tracheitis, bronchiolitis, and interstitial pneumonia. Infections caused by paramyxoviruses often spread between species, manifesting disease in spillover hosts, including humans. This review focuses on the paramyxoviruses in rodents, including the epidemiological distributions, transmission and pathogenesis, clinical manifestations, diagnostic methods, and control and prevention of paramyxoviruses infection to provide a better understanding of these highly mutating viruses.

Pathogenesis of a novel porcine parainfluenza virus type 1 isolate in conventional and colostrum deprived/caesarean derived pigs.

Two experimental challenge studies were conducted to evaluate the pathogenesis of a porcine parainfluenza virus type 1 (PPIV-1) isolate. Four-week-old conventional (CON) pigs were challenged in Study 1 and six-week-old caesarean derived/colostrum deprived (CDCD) pigs were challenged in Study 2. Results indicate that PPIV-1 shedding and replication occur in the upper and lower respiratory tracts of CON and CDCD pigs as detected by RT-qPCR and immunohistochemistry. Mild macroscopic lung lesions were observed in CON pigs but not in CDCD pigs. Microscopic lung lesions were mild and consisted of peribronchiolar lymphocytic cuffing and epithelial proliferation in CON and CDCD pigs. Serum neutralizing antibodies were detected in the CON and CDCD pigs by 14 and 7 days post inoculation, respectively. This study provides evidence that in spite of PPIV-1 infection and replication in challenged swine, significant clinical respiratory disease was not observed.

Paramyxoviruses from neotropical bats suggest a novel genus and nephrotropism.

Paramyxoviruses have a broad host range and geographic distribution, including human pathogens transmitted by bats, such as Nipah and Hendra viruses. In this study, we combined high-throughput sequencing and molecular approaches to investigate the presence of paramyxoviruses in neotropical bats (Microchiroptera suborder) in Brazil. We discovered and characterized three novel paramyxoviruses in the kidney tissues of apparently healthy common vampire bats (D. rotundus) and Seba's short-tailed bats (C. perspicillata), which we tentatively named Kanhgág virus (KANV), Boe virus (BOEV), and Guató virus (GUATV). In this study, we classified these viruses as putative species into the Macrojêvirus genus, a newly proposed genus of the Orthoparamyxovirinae subfamily. Using RT-PCR, we detected these viruses in 20.9% (9 out of 43) of bats tested, and viral RNA was detected exclusively in kidney tissues. Attempts to isolate infectious virus were successful for KANV and GUATV. Our results expand the viral diversity, host range, and geographical distribution of the paramyxoviruses.