Molecular and genetic characterization of bovine parainfluenza type 3 European field and vaccine strains.

Bovine Parainfluenza Type 3 virus (BPIV-3) is an enveloped, non-segmented single-stranded, negative-sense RNA virus belonging to the Paramyxoviridae family (genus Respirovirus) with a well-known role in Bovine Respiratory Disease (BRD) onset. Being isolated for the first time in 1959, BPIV-3 currently circulates worldwide in cattle herds and is routinely tested in suspected BRD cases. Different commercial vaccines are available to prevent infection and/or to reduce the clinical signs associated with BPIV-3 infection, which are essential to prevent secondary infections. Despite years of molecular surveillance, a very limited number of complete genome sequences were made publicly available, preventing thus the understanding of the genetic diversity of the circulating strains in the field. In addition, no data about the genetic identity between field and vaccine strains is currently available. In this study, we sequenced the full-genome and genetically characterized BPIV-3 strains isolated from animals displaying respiratory illness in France and Sweden, as well as the vaccine strains contained in three different commercialized vaccines. Our results show that the sequences from France and Sweden belong to genotype C. However, a third sequence from Sweden from 2017 clustered within genotype A. The sequencing of vaccine strains revealed that two of the vaccine strains clustered within genotype C, whereas the third vaccine strain belonged to genotype A. Altogether, our findings suggest that both genotypes A and C circulate in Europe and that BPIV-3 field and vaccine strains are genetically divergent. Our sequencing results could be useful to better understand the genetic differences between the circulating field and vaccine BPIV-3 strains. This is crucial for a correct interpretation of diagnostic findings and for the assessment of BPIV-3 prevalence in cattle population.

Emergence of swine influenza A virus, porcine respirovirus 1 and swine orthopneumovirus in porcine respiratory disease in Germany.

Respiratory disease is a significant economic issue in pig farming, with a complex aetiology that includes swine influenza A viruses (swIAV), which are common in European domestic pig populations. The most recent human influenza pandemic in 2009 showed swIAV's zoonotic potential. Monitoring pathogens and disease control are critical from a preventive standpoint, and are based on quick, sensitive, and specific diagnostic assays capable of detecting and distinguishing currently circulating swIAV in clinical samples. For passive surveillance, a set of multiplex quantitative reverse transcription real-time PCRs (mRT-qPCR) and MinION-directed sequencing was updated and deployed. Several lineages and genotypes of swIAV were shown to be dynamically developing, including novel reassortants between human pandemic H1N1 and the avian-derived H1 lineage of swIAV. Despite this, nearly 70% (842/1216) of individual samples from pigs with respiratory symptoms were swIAV-negative, hinting to different aetiologies. The complex and synergistic interactions of swIAV infections with other viral and bacterial infectious agents contribute to the aggravation of pig respiratory diseases. Using a newly developed mRT-qPCR for the combined detection of swIAV and the recently described porcine respirovirus 1 (PRV1) and swine orthopneumovirus (SOV) widespread co-circulation of PRV1 (19.6%, 238/1216 samples) and SOV (14.2%, 173/1216 samples) was evident. Because of the high incidence of PRV1 and SOV infections in pigs with respiratory disease, these viruses may emerge as new allies in the porcine respiratory disease syndrome.

[Intranasal vaccine against COVID-19 based on a recombinant variant of the Sendai virus (Paramyxoviridae: Respirovirus) strain Moscow].

INTRODUCTION: Intranasal vaccination using live vector vaccines based on non-pathogenic or slightly pathogenic viruses is the one of the most convenient, safe and effective ways to prevent respiratory infections, including COVID-19. Sendai virus is the best suited for this purpose, since it is respiratory virus and is capable of limited replication in human bronchial epithelial cells without causing disease. The aim of the work is to design and study the vaccine properties of recombinant Sendai virus, Moscow strain, expressing secreted receptor-binding domain of SARS-CoV-2 Delta strain S protein (RBDdelta) during a single intranasal immunization. MATERIALS AND METHODS: Recombinant Sendai virus carrying insertion of RBDdelta transgene between P and M genes was constructed using reverse genetics and synthetic biology methods. Expression of RBDdelta was analyzed by Western blot. Vaccine properties were studied in two models: Syrian hamsters and BALB/c mice. Immunogenicity was evaluated by ELISA and virus-neutralization assays. Protectiveness was assessed by quantitation of SARS-CoV-2 RNA in RT-PCR and histological analysis of the lungs. RESULTS: Based on Sendai virus Moscow strain, a recombinant Sen-RBDdelta(M) was constructed that expressed a secreted RBDdelta immunologically identical to natural SARS-CoV-2 protein. A single intranasal administration of Sen-RBDdelta(M) to hamsters and mice significantly, by 15 and 107 times, respectively, reduced replicative activity of SARS-CoV-2 in lungs of animals, preventing the development of pneumonia. An effective induction of virus-neutralizing antibodies has also been demonstrated in mice. CONCLUSION: Sen-RBDdelta(M) is a promising vaccine construct against SARS-CoV-2 infection and has a protective properties even after a single intranasal introduction.

First report of Porcine respirovirus 1 in South Korea.

Porcine respirovirus 1 (PRV1) is a recently emerging porcine respiratory virus that belongs to the genus Respirovirus of the Paramyxoviridae family. Since its first detection in Hong Kong, China in 2009, PRV1 has been subsequently identified in several American and European countries, suggesting that the emerging virus may have been globally distributed. However, in Asia, the virus has been reported only in China. Here, we report that PRV1 was first detected in pigs from 16 farms located in seven provinces across Korea, with a prevalence of 71.4% based on the tested oral fluid samples, suggesting that the virus is already widespread in Korean pig herds. For further genetic characterization of the Korean PRV1 strains, a complete genome and two F gene sequences were obtained from PRV1-positive samples collected from three different pig farms. Phylogenetic analysis based on the complete genome and F gene sequences showed that all three Korean PRV1 strains were grouped into European lineage 1 and were closely related to strains from Hong Kong (China), Germany and Poland. We could not obtain evidence for the origin of Korean PRV1 because of the limited availability of PRV1 sequences. In conclusion, PRV1 was first identified in Korean pig herds and genetically characterized in the present study. These results contribute to a better understanding of the global geographical distribution and genetic characteristics of PRV1.

Characterization of an emerging porcine respirovirus 1 isolate in the US: A novel viral vector for expression of foreign antigens.

Porcine respirovirus 1 (PRV1) is widely spread in many countries. In this study, we isolated an emgerging PRV1 strain (KS17-258) from a US swine farm. A full-length genome sequence of the virus was obtained, and the mRNA editing mechanism utilized for the expression of V/W proteins by P gene was confirmed. The virus shares 91.3-98% nucleotide sequence identity with the other PRV1 genomes reported previously. Phylogenetic analysis showed that KS17-258 forms a clade with the other US isolates. Infectious clone of the KS17-258 isolate was constructed, which was further explored as a viral vector to express enhanced green fluorescent protein (EGFP). The expression cassette of EGFP in the recombinant virus remained stable for 10 passages in cell culture. The availability of PRV1 infectious clone provides an important tool for study the basic PRV1 replication mechanisms. It also provides a novel platform for potential development of vectored vaccines against swine diseases.

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.

Comparison of 11 respiratory pathogens among hospitalized children before and during the COVID-19 epidemic in Shenzhen, China.

BACKGROUND: The effect of SARS-CoV-2 on existing respiratory pathogens in circulation remains uncertain. This study aimed to assess the impact of SARS-CoV-2 on the prevalence of respiratory pathogens among hospitalized children. METHODS: This study enrolled hospitalized children with acute respiratory infections in Shenzhen Children's Hospital from September to December 2019 (before the COVID-19 epidemic) and those from September to December 2020 (during the COVID-19 epidemic). Nasopharyngeal swabs were collected, and respiratory pathogens were detected using multiplex PCR. The absolute case number and detection rates of 11 pathogens were collected and analyzed. RESULTS: A total of 5696 children with respiratory tract infection received multiplex PCR examination for respiratory pathogens: 2298 from September to December 2019 and 3398 from September to December 2020. At least one pathogen was detected in 1850 (80.5%) patients in 2019, and in 2380 (70.0%) patients in 2020; the detection rate in 2020 was significantly lower than that in 2019.The Influenza A (InfA) detection rate was 5.6% in 2019, but 0% in 2020. The detection rates of Mycoplasma pneumoniae, Human adenovirus, and Human rhinovirus also decreased from 20% (460), 8.9% (206), and 41.8% (961) in 2019 to 1.0% (37), 2.1% (77), and 25.6% (873) in 2020, respectively. In contrast, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased from 6.6% (153), 9.9% (229), and 0.5% (12) in 2019 to 25.6% (873), 15.5% (530), and 7.2% (247) in 2020, respectively (p < 0.0001). CONCLUSIONS: Successful containment of seasonal influenza as a result of COVID-19 control measures will ensure we are better equipped to deal with future outbreaks of both influenza and COVID-19.Caused by virus competition, the detection rates of Human respiratory syncytial virus, Human parainfluenza virus, and Human metapneumovirus increased in Shenzhen,that reminds us we need to take further monitoring and preventive measures in the next epidemic season.

Bovine respiratory disease in beef calves supported long transport stress: An epidemiological study and strategies for control and prevention.

BRD is associated with infectious agents, but management and transport-stress are trigger factors. Metaphylactic administration of antimicrobial reduces colonization of respiratory tract by pathogens, but the development of antibiotic-resistance raises public health concerns leading to propose new control strategies. The study analyzed nasopharyngeal swabs of 231 imported cattle, 10% of 49 trucks, transported from France to southern Italy and, through Real-time PCR identified the prevalence of the involved pathogens speculating on strategies to reduce the impact of BRD. The samples were tested by Real-time PCR, for the detection of bovine coronavirus (BCoV), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus (BPiV), bovine adenovirus (BAdV), Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Yates-corrected chi squared, or Fisher's exact test were used to compare both animal-health status and positivity/negativity to pathogens, and the relationship between presence/absence of clinical signs and Real-time PCR-positivity. H. somni and BCoV were the most frequently identified pathogens. In BRD-diagnosed cattle, BAdV was detected in 13.8% (19/138), BRSV in 14.5% (20/138) and BPiV in 4.3% (6/138). Healthy cattle were mostly positive for H. somni (89.2%, 83/93). A statistically significant association was observed between clinical signs and positivity to M. haemolytica (p value = 0.016). Although mass-medication and vaccination are used for BRD control, it still remains a primary health problem. Our results highlight that the nasopharyngeal microbiota could be affected by transport and that strategies to enhance calf immunity for reducing BRD-risk development would be more effective if applied at farm of origin prior to loading.

A Parainfluenza Virus Vector Expressing the Respiratory Syncytial Virus (RSV) Prefusion F Protein Is More Effective than RSV for Boosting a Primary Immunization with RSV.

Live-attenuated pediatric vaccines for intranasal administration are being developed for human respiratory syncytial virus (RSV), an important worldwide pediatric respiratory pathogen that lacks a licensed vaccine or suitable antiviral drug. We evaluated a prime-boost strategy in which primary immunization with RSV was boosted by secondary immunization with RSV or with a chimeric recombinant bovine/human parainfluenza virus type 3 (rB/HPIV3) vector expressing the RSV fusion F protein. The vector-expressed F protein had been engineered (DS-Cav1 mutations) for increased stability in the highly immunogenic prefusion (pre-F) conformation, with or without replacement of its transmembrane and cytoplasmic tail domains with their counterparts from bovine parainfluenza virus type 3 (BPIV3) F protein to direct incorporation into the vector virion for increased immunogenicity. In hamsters that received a primary infection with RSV, a booster infection with RSV ∼6 weeks later was completely restricted for producing infectious virus but induced a significant increase in the serum RSV-plaque-reduction neutralizing antibody titer (RSV-PRNT). Boosting instead with the rB/HPIV3-RSV-pre-F vectors resulted in efficient replication and induced significantly higher RSV-PRNTs than RSV. In African green monkeys that received a primary infection with RSV, a booster infection with RSV ∼2, ∼6, or ∼15 months later was highly restricted, whereas booster infections with the vectors had robust replication. Compared with RSV, boosts with the vectors induced 7- to 15-fold higher titers of RSV-specific serum antibodies with high neutralizing activity, as well as significantly higher titers of RSV-specific mucosal IgA antibodies. These findings support further development of this heterologous prime-boost strategy.IMPORTANCE Immune responses to RSV in infants can be reduced due to immunological immaturity and immunosuppression by RSV-specific maternal antibodies. In infants and young children, two infections with wild-type RSV typically are needed to achieve the titers of RSV-specific serum antibodies and protection against illness that are observed in adults. Therefore, a boost might substantially improve the performance of live pediatric RSV vaccines presently being developed. Hamsters and African green monkeys received a primary intranasal infection with RSV and were given a boost with RSV or a parainfluenza virus (PIV) vector expressing RSV fusion protein engineered for enhanced immunogenicity. The RSV boost was highly restricted but induced a significant increase in serum RSV-neutralizing antibodies. The PIV vectors replicated efficiently and induced significantly higher antibody responses. The use of an attenuated PIV vector expressing RSV antigen to boost a primary immunization with an attenuated RSV warrants further evaluation.

Co-detection of Bordetella pertussis and other respiratory organisms in children hospitalised with lower respiratory tract infection.

Multiple potential pathogens are frequently co-detected among children with lower respiratory tract infection (LRTI). Evidence indicates that Bordetella pertussis has an important role in the aetiology of LRTI. We aimed to study the association between B. pertussis and other respiratory pathogens in children hospitalised with severe LRTI, and to assess clinical relevance of co-detection. Nasopharyngeal (NP) swabs and induced sputa (IS) were tested with a B. pertussis specific PCR; additionally, IS was tested for other pathogens using a multiplex PCR. We included 454 children, median age 8 months (IQR 4-18), 31 (7%) of whom tested positive for B. pertussis. Children with B. pertussis had more bacterial pathogens detected (3 versus 2; P < 0.001). While B. pertussis showed no association with most pathogens, it was independently associated with Chlamydia pneumoniae, Mycoplasma pneumoniae and parainfluenza viruses with adjusted risk ratios of 4.01 (1.03-15.64), 4.17 (1.42-12.27) and 2.13 (1.03-4.55), respectively. There was a consistent increased risk of severe disease with B. pertussis. Patterns indicated even higher risks when B. pertussis was co-detected with any of the three organisms although not statistically significant. Improving vaccine coverage against B. pertussis would impact not only the incidence of pertussis but also that of severe LRTI generally.

First report of porcine respirovirus 1 in South America.

Porcine respirovirus 1 (PRV1) is an emerging virus in pigs that has been previously described in the USA and China. There are no reports of its presence in the rest of the world. The objective of this study was to determine the occurrence of PRV1 in Chile and to determine its phylogeny. Thus, we collected samples (oral fluids, nasal swabs, and lungs) from a swine influenza A virus (IAV) surveillance program, most of which belonged to pigs with respiratory disease. The samples were analyzed by RT-PCR, and the viral sequencing was obtained using RNA whole-genome sequencing approach. Maximum likelihood phylogeny was constructed with the available references. Thirty-one of 164 samples (18.9 %) were RT-PCR positive for PRV1: 62.5 % oral fluids, 19.0 % nasal swabs, and 8.6 % lungs. All 6 farms in this study had at least one positive sample, with 6-40 % of positive results per farm, which suggests that PRV1 is disseminated in Chilean swine farms. Twenty-one of 31 (677%) PRV1-positive samples were also positive for IAV, so the role of PRV1 as secondary pathogen in respiratory disease needs to be further evaluated. Near to complete genome of two PRV1s were obtained from two farms. The phylogenies, in general, showed low bootstrap support, except the concatenated genome and the L gene trees which showed clustering of the Chilean PRV1 with Asian sequences, suggesting a close genetic relationship. This is the first report of PRV1 in the Southern Hemisphere. Further studies are necessary to determine the genetic diversity of this virus in Chile.

Viral etiology of pneumonia among severely malnourished under-five children in an urban hospital, Bangladesh.

BACKGROUND: In Bangladesh, pneumonia has a higher mortality among malnourished children aged <5 years. Evaluating pneumonia etiology among malnourished children may help improve empiric treatment guidelines. METHODS: During April 2015-December 2017, we conducted a case-control study among severe acute malnourished (SAM) children aged <5 years admitted to the Dhaka hospital of International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). We enrolled hospital admitted SAM children with clinical or radiological pneumonia as cases (during April 2015 to March 2017) and hospital admitted SAM children without any respiratory symptom in the past 10 days before admission as controls (during February 2016 to December 2017). We tested nasopharyngeal wash from both case and control for respiratory syncytial virus (RSV), human metapneumovirus (HMPV), influenza viruses, human parainfluenza viruses (HPIV), rhinovirus and adenovirus by singleplex real-time reverse transcriptase polymerase chain reaction. To identify the independent association of pneumonia with viral pathogens during February 2016 to March 2017, we used multivariable logistic regression for calculating adjusted odds ratios. RESULTS: We enrolled 360 cases and 334 controls. For case and control the median age was 8 months (IQR: 5-13) and 11 months (IQR: 6-18) (p = 0.001) respectively. Weight/age Z-score was -4.3 (SD ±0.7) for cases and -4.1 (SD ±1.1) for controls (p = 0.01). Among cases 68% had both clinical and radiological pneumonia, 1% had clinical pneumonia and 31% had only radiological pneumonia. Respiratory virus detection was high in cases compared to controls [69.9% (251) vs. 44.8% (148), p = 0.0001]. The most frequently detected viruses among cases were rhinoviruses (79, 22.0%) followed by RSV (32, 8.9%), adenovirus (23, 6.4%), HPIV (22, 6.1%), influenza virus (16, 4.5%), and HMPV (16, 4.5%). Among the controls, rhinoviruses (82, 24.8%) were most commonly detected one followed by adenovirus (26,7.9%), HMPV (5, 1.5%), HPIV (4, 1.2%), RSV (3, 0.9%), and influenza virus (2, 0.6%). RSV (OR 13.1; 95% CI: 1.6, 106.1), influenza virus (OR 8.7; 95% CI: 1.0, 78.9), HPIV (3.8; 95% CI: 1.0, 14.8), and HMPV (2.7; 95% CI: 1.3, 5.5) were independently associated with pneumonia while compared between 178 cases and 174 controls. CONCLUSION: Viral etiology of pneumonia in SAM children were mainly attributable to RSV, influenza, HPIV and HMPV. Our study findings may help in planning further studies targeting vaccines or drugs against common respiratory viruses responsible for pneumonia among SAM children.

Comparative global epidemiology of influenza, respiratory syncytial and parainfluenza viruses, 2010-2015.

OBJECTIVES: To improve our understanding of the global epidemiology of common respiratory viruses by analysing their contemporaneous incidence at multiple sites. METHODS: 2010-2015 incidence data for influenza A (IAV), influenza B (IBV), respiratory syncytial (RSV) and parainfluenza (PIV) virus infections were collected from 18 sites (14 countries), consisting of local (n = 6), regional (n = 9) and national (n = 3) laboratories using molecular diagnostic methods. Each site submitted monthly virus incidence data, together with details of their patient populations tested and diagnostic assays used. RESULTS: For the Northern Hemisphere temperate countries, the IAV, IBV and RSV incidence peaks were 2-6 months out of phase with those in the Southern Hemisphere, with IAV having a sharp out-of-phase difference at 6 months, whereas IBV and RSV showed more variable out-of-phase differences of 2-6 months. The tropical sites Singapore and Kuala Lumpur showed fluctuating incidence of these viruses throughout the year, whereas subtropical sites such as Hong Kong, Brisbane and Sydney showed distinctive biannual peaks for IAV but not for RSV and PIV. CONCLUSIONS: There was a notable pattern of synchrony of IAV, IBV and RSV incidence peaks globally, and within countries with multiple sampling sites (Canada, UK, Australia), despite significant distances between these sites.

Proteomics analysis reveals heat shock proteins involved in caprine parainfluenza virus type 3 infection.

BACKGROUND: Caprine parainfluenza virus type 3 (CPIV3) is major pathogen of goat herds causing serious respiratory tract disease and economic losses to the goat industry in China. We analyzed the differential proteomics of CPIV3-infected Madin-Darby bovine kidney (MDBK) cells using quantitative iTRAQ coupled LC-MS/MS. In addition, four DEPs were validated by qRT-PCR and western blot analysis. RESULTS: Quantitative proteomics analysis revealed 163 differentially expressed proteins (DEPs) between CPIV3-infected and mock-infected groups (p-value < 0.05 and fold change > 1.2), among which 91 were down-regulated and 72 were up-regulated. Gene ontology (GO) analysis showed that these DEPs were involved in molecular functions, cellular components and biological processes. Biological functions in which the DEPs were involved in included diseases, genetic information processing, metabolism, environmental information processing, cellular processes, and organismal systems. STRING analysis revealed that four heat shock proteins (HSPs) included HSPA5, HSPA1B, HSP90B1 and HSPA6 may be associated with proliferation of CPIV3 in MDBK cells. qRT-PCR and western blot analysis showed that the selected HSPs were identical to the quantitative proteomics data. CONCLUSION: To our knowledge, this is the first report of the proteomic changes in MDBK cells after CPIV3 infection.

Clinical characteristics of the lower respiratory tract infection caused by a single infection or coinfection of the human parainfluenza virus in children.

BACKGROUND: Human parainfluenza virus (HPIV), usually combined with other pathogens, causes lower respiratory tract infection (LRTI) in children. However, clinical characteristics of HPIV coinfection with other pathogens were unclear. This study aimed to investigate the viral and atypical bacterial etiology of LRTI in children and compare the clinical characteristics of HPIV single infection with those of coinfection. METHODS: This study included 1335 patients, aged between 1 to 71 months, diagnosed with LRTI in Yuying Children's Hospital, Zhejiang, China, from December 2013 to June 2015. Nasopharyngeal secretions were collected, and respiratory pathogens were detected using Multiplex polymerase chain reaction. The clinical data of patients were collected and analyzed. RESULTS: At least 1 pathogen was detected in 1181/1335 (88.5%) patients. The pathogens identified most frequently were respiratory syncytial virus, human rhinovirus, HPIV, adenovirus, and human metapneumovirus. The coinfection rate was 24.8%. HPIV coinfection with other viruses was more associated with running nose, shortness of breath, and oxygen support compared with HPIV single infection. Moreover, HPIV coinfection with atypical bacteria was more related to running nose, moist rales, and longer hospital duration compared with HPIV single infection, and also to longer hospital duration compared with coinfection with other viruses. CONCLUSIONS: This study demonstrated that viral infections were highly associated with LRTI and the rate of coinfection was high. HPIV single infection was milder than coinfection with other viruses. Moreover, HPIV coinfection with atypical bacteria was more serious than HPIV single infection and coinfection with other viruses.

Detection, isolation, and in vitro characterization of porcine parainfluenza virus type 1 isolated from respiratory diagnostic specimens in swine.

Porcine parainfluenza virus type 1 (PPIV-1) is a member of the genus Respirovirus in the family Paramyxoviridae. The PPIV-1 was initially detected in 2013 from slaughter pigs in Hong Kong, China although its role in respiratory disease has remained unknown without virus isolates for experimental inoculation in swine. The objective of this study was to determine the relative frequency of PPIV-1 detection in diagnostic samples collected from swine in the United States, describe the cell culture isolation of PPIV-1, and characterize PPIV-1 cell culture isolates in vitro. Among 842 porcine specimens submitted to the Iowa State University Veterinary Diagnostic Laboratory during 2016-2017, 43.3% were PPIV-1 positive by a real-time, reverse transcriptase PCR suggesting PPIV-1 may be common in swine. Two strains of PPIV-1 were successfully isolated in an LLC-MK2 cell line from a PPIV-1 RT-qPCR positive nasal swab (USA/MN25890NS/2016) and lung (USA/IA84915LG/2017). The PPIV-1 cytopathic effect was demonstrated in tissue culture and enveloped viral particles were observed by electron microscopy. The whole genome, F, and HN gene sequences of both isolates share 98.2%, 98.5%, and 98.2% nucleotide homology, respectively, and phylogenetic analysis indicated they are closely related to other PPIV-1 strains detected in swine from the United States. Whole virus PPIV-1-specific monoclonal antibodies were generated for PPIV-1 detection in infected LLC-MK2 cells by indirect immunofluorescence and immunocytochemistry assays. The virus isolates and monoclonal antibodies obtained in the present study can be used to investigate the pathogenesis of PPIV-1 and develop new diagnostic tests.

Metagenomic analysis of viral nucleic acid extraction methods in respiratory clinical samples.

BACKGROUND: Numerous protocols for viral enrichment and genome amplification have been created. However, the direct identification of viral genomes from clinical specimens using next-generation sequencing (NGS) still has its challenges. As a selected viral nucleic acid extraction method may determine the sensitivity and reliability of NGS, it is still valuable to evaluate the extraction efficiency of different extraction kits using clinical specimens directly. RESULTS: In this study, we performed qRT-PCR and viral metagenomic analysis of the extraction efficiency of four commonly used Qiagen extraction kits: QIAamp Viral RNA Mini Kit (VRMK), QIAamp MinElute Virus Spin Kit (MVSK), RNeasy Mini Kit (RMK), and RNeasy Plus Micro Kit (RPMK), using a mixed respiratory clinical sample without any pre-treatment. This sample contained an adenovirus (ADV), influenza virus A (Flu A), human parainfluenza virus 3 (PIV3), human coronavirus OC43 (OC43), and human metapneumovirus (HMPV). The quantity and quality of the viral extracts were significantly different among these kits. The highest threshold cycle(Ct)values for ADV and OC43 were obtained by using the RPMK. The MVSK had the lowest Ct values for ADV and PIV3. The RMK revealed the lowest detectability for HMPV and PIV3. The most effective rate of NGS data at 67.47% was observed with the RPMK. The other three kits ranged between 12.1-26.79% effectiveness rates for the NGS data. Most importantly, compared to the other three kits the highest proportion of non-host reads was obtained by the RPMK. The MVSK performed best with the lowest Ct value of 20.5 in the extraction of ADV, while the RMK revealed the best extraction efficiency by NGS analysis. CONCLUSIONS: The evaluation of viral nucleic acid extraction efficiency is different between NGS and qRT-PCR analysis. The RPMK was most applicable for the metagenomic analysis of viral RNA and enabled more sensitive identification of the RNA virus genome in respiratory clinical samples. In addition, viral RNA extraction kits were also applicable for metagenomic analysis of the DNA virus. Our results highlighted the importance of nucleic acid extraction kit selection, which has a major impact on the yield and number of viral reads by NGS analysis. Therefore, the choice of extraction method for a given viral pathogen needs to be carefully considered.

New clinical and seasonal evidence of infections by Human Parainfluenzavirus.

Human Parainfluenzaviruses (PIVs) account for a significant proportion of viral acute respiratory infections (ARIs) in children, and are also associated with morbidity and mortality in adults, including nosocomial infections. This work aims to describe PIV genotypes and their clinical and epidemiological distribution. Between December 2016 and December 2017, 6121 samples were collected, and submitted to viral culture and genomic quantification, specifically Parainfluenza 1-4 (PIV1-4), Influenza A and B, Respiratory Syncytial Virus (RSV) A and B, Adenovirus, Metapneumovirus, Coronavirus, Rhinovirus, and Enterovirus. Normalized viral load, as (log10) copies/103 cells, was calculated as virus Ct, determined by multiple qRT-PCR, as a function of the Ct of ß-globin. PIV was confirmed in 268 cases (4.37%), and linked to both upper and lower respiratory tract disease, being more frequent in children than in adults (5.23 and 2.43%, respectively). PIV1 and PIV3 were most common (31 and 32.5%, of total PIV positive samples, respectively), with distribution being similar in children and adults, as was viral load. PIV type was correlated with seasonality: PIV3 being more frequent in winter and spring, PIV1 in summer, and PIV 4 in fall. No correlation between vial load and clinical severity was found. Novel findings were that PIV viral load was higher in fall than in other seasons, and PIV4, classically linked to mild respiratory symptoms, was circulating, in children and adults, at all levels of symptoms throughout the year.

A lateral flow dipstick combined with reverse transcription recombinase polymerase amplification for rapid and visual detection of the bovine respirovirus 3.

Bovine respirovirus 3 also known as Bovine parainfluenza virus type 3 (BPIV3) is one of the most important viral respiratory agents of both young and adult cattle. Rapid diagnosis could contribute greatly in containing epidemics and thus avoid economic losses. However, the lack of robust isothermal visual method poses difficulty. In this study, a novel isothermal assay for detecting BPIV3 was established. The method includes a lateral flow dipstick (LFD) assay combined with reverse transcription recombinase polymerase amplification (RT-RPA). First, the analytical sensitivity and specificity of BPIV3 LFD RT-RPA were tested. The LFD RT-RPA assay has a detection limit of up to 100 copies per reaction in 30 min at 38 °C. Then the performance of LFD RT-RPA was evaluated using 95 clinical samples. Compared to qPCR, the LFD RT-RPA assay showed a clinical sensitivity of 94.74%, a clinical specificity of 96.05% and 0.8734 kappa coefficient. These results have demonstrated the efficiency and effectiveness of the method to be developed into a point of care protocol for the diagnosis of BPIV3.

A Novel Squirrel Respirovirus with Putative Zoonotic Potential.

In a globalized world, the threat of emerging pathogens plays an increasing role, especially if their zoonotic potential is unknown. In this study, a novel respirovirus, family Paramyxoviridae, was isolated from a Sri Lankan Giant squirrel (Ratufa macroura), which originated in Sri Lanka and deceased with severe pneumonia in a German zoo. The full-genome characterization of this novel virus, tentatively named Giant squirrel respirovirus (GSqRV), revealed similarities to murine (71%), as well as human respiroviruses (68%) with unique features, for example, a different genome length and a putative additional accessory protein. Congruently, phylogenetic analyses showed a solitary position of GSqRV between known murine and human respiroviruses, implicating a putative zoonotic potential. A tailored real-time reverse transcription-polymerase chain reaction (RT-qPCR) for specific detection of GSqRV confirmed a very high viral load in the lung, and, to a lesser extent, in the brain of the deceased animal. A pilot study on indigenous and exotic squirrels did not reveal additional cases in Germany. Therefore, further research is essential to assess the geographic distribution, host range, and zoonotic potential of this novel viral pathogen.