Surveillance, isolation and complete genome sequence of bovine parainfluenza virus type 3 in Egyptian cattle

Isolation and Genomic Characterization of a Chinese Genotype C Bovine Parainfluenza Virus Type 3 from Cattle and Its Pathogenicity in C57BL/6 Mice

Bovine parainfluenza virus type 3 (BPIV-3), also known as bovine respirovirus 3, is a common respiratory pathogen associated with bovine respiratory disease (BRD). BPIV-3 has currently circulated worldwide; however, data on the prevalence and genetic characteristics of BPIV-3 are still scarce and limited. In this study, the BPIV-3 strain SC was identified and isolated from cattle presenting with clinical signs of BRD in China. Animal experiments indicated that BPIV-3 SC can successfully infect C57BL/6 mice and induce weight loss, lung inflammatory cell infiltration, and inflammatory cytokine expression in mice. In addition, the complete genome of BPIV-3 SC was obtained using next-generation sequencing and was 15,473 bp in length. Phylogenetic analysis indicated that BPIV-3 SC belonged to genotype C, which clustered in the same large clade consisting of a population of Chinese genotype C strains but was found to be different from the other strains upon further differentiation. Compared to other Chinese genotype C strains, the BPIV-3 SC showed 70 unique nucleotide mutations and 13 unique amino acid mutations in the HN, P, and L proteins, suggesting a unique genetic evolution of BPIV-3 SC. In conclusion, we isolated and characterized a differential Chinese genotype C BPIV-3, which contributed to an understanding of the prevalence and evolution of BPIV-3 in China.

Isolation, Identification, and Genetic Phylogenetic Analysis of Two Different Genotypes of Bovine Parainfluenza 3 Virus in China

Bovine parainfluenza virus 3 (BPIV3) is one of several viruses that contribute to bovine respiratory disease complex (BRDC). During this study, isolation of BPIV3 was attempted from 20 PCR-positive swabs by Madin-Darby Bovine Kidney (MDBK) cells. Nine samples showed obvious cytopathic lesions identified as BPIV3 by reverse-transcription polymerase chain reaction amplification and sequencing. The genomes of isolates XJ21032-1 and XJ20055-3 were sequenced using Illumina sequencing technology and determined to have lengths of 15,512 bp and 15,479 bp, respectively. Phylogenetic analysis revealed that isolate XJ21032-1 was genotype B, and isolate XJ20055-3 was genotype C. In addition, the two isolates had multiple amino acid changes in nucleocapsid protein, fusion protein, and hemagglutinin/neuraminidase, major antigenic proteins. This allows the further recognition of the presence of BPIV3 type B in Chinese cattle herds. We hope this will help trace the origin of BPIV3, improve the understanding of differences between genotypes, and provide data support for vaccine development.

Immune cell composition of the bronchoalveolar lavage fluid in healthy and respiratory diseased dromedary camels

Background

Respiratory diseases are among the most common and expensive to treat diseases in camels with a great economic impact on camel health, welfare, and production. Bronchoalveolar lavage fluid (BALF) has been proven as a valuable sample for investigating the leukocyte populations in the respiratory tract of several species. In the present study, fluorescent antibody labeling and flow cytometry were used to study the immune cell composition of BALF in dromedary camels. Animals with clinical respiratory diseases (n = seven) were compared with apparently healthy animals (n = 10). In addition, blood leukocytes from the same animals were stained in parallel with the same antibodies and analyzed by flow cytometry.

Results

Camel BALF macrophages, granulocytes, monocytes, and lymphocytes were identified based on their forward and side scatter properties. The expression pattern of the cell markers CD172a, CD14, CD163, and MHCII molecules on BALF cells indicates a similar phenotype for camel, bovine, and porcine BALF myeloid cells. The comparison between camels with respiratory disease and healthy camels regarding cellular composition in their BALF revealed a higher total cell count, a higher fraction of granulocytes, and a lower fraction of macrophages in diseased than healthy camels. Within the lymphocyte population, the percentages of helper T cells and B cells were also higher in diseased than healthy camels. The elevated expression of the activation marker CD11a on helper T cells of diseased camels is an indication of the expansion of helper T cells population due to infection and exposure to respiratory pathogens. The higher abundance of MHCII molecules on BALF macrophages from diseased camels indicates a polarization toward an inflammatory macrophage phenotype (M1) in respiratory diseased camels. No significant differences were observed in the systemic leukogram between healthy and diseased animals.

Conclusions

Collectively, the current study represents the first report on flow cytometric analysis of immune cell composition of bronchoalveolar lavage fluid (BALF) in dromedary camels.

Homologous recombination as a mechanism of genetic changes in bovine parainfluenza-3 virus

Bovine parainfluenza-3 virus (BPIV-3) is one of the main viruses associated with bovine respiratory disease complex (BRDC) worldwide. BPIV-3 infect the bovine respiratory tract causing from subclinical infections to severe pneumonia with significant economic losses in the cattle industry. BPIV-3 is a RNA virus with high genetic variability, nevertheless, the contribution of recombination events to its variability has not been assessed so far. In this study the 25 complete genome sequences (CGS) reported so far and 215 partial sequences of different viral genes of BPIV-3 were analyzed to determine their genotypes and subgenotypes, distribution, and the existence of potential recombination events. Based on the analysis of the HN, M, N, and P genes one hypothetical subgenotype was found (subgenotype A4). Four recombination events between sequences of swine and cattle were detected by RDP4 analysis in conjunction with phylogenetic incongruences in the L gene. In addition, 9 sequences reported from Argentina were found to be miss-classified. These results reveal that homologous recombination events have a relevant role in the evolution of BPIV-3 and highlight the importance of implement advanced molecular characterization to better understand the variability and evolution of BPIV-3 as a component of BRDC.

Phylogenetic and antigenic analysis of bovine parainfluenza virus type 3 isolated in Japan between 2002 and 2019

Bovine parainfluenza virus type 3 (BPIV3) is one of the most important viral respiratory pathogens of cattle. In addition to the classical BPIV3 genotype A (BPIV3a), new genetic groups, genotype B (BPIV3b) and C (BPIV3c), have been identified and isolated in certain parts of the world. The present study aimed to investigate the genetic and antigenic characteristics of BPIV3 circulating in Japan. Seventy-three BPIV3 field strains were isolated from nasal samples of cattle between 2002 and 2019. Phylogenetic analysis of the phosphoprotein and hemagglutinin-neuraminidase genes showed that the isolates clustered into two genotypes, BPIV3a (49 %) and BPIV3c (51 %). The BPIV3a strains had more wide genetic variation than the rest of the genotypes. Additionally, new variants were obtained and designated them tentatively as subgroup 4 of the BPIV3a. The first Japanese BPIV3c was isolated in 2012, but here the BPIV3c NM2 strain was isolated from a sample collected four years earlier than the previous report. The antigenicity of ten BPIV3 strains including all three genotypes was assessed with a viral cross-neutralization test. Anti-sera against BPIV3a and BPIV3b cross-reacted well with both homologous and heterologous viruses. On the other hand, anti-sera against BPIV3c had reduced cross-reactivity to the heterologous viruses. Overall, our findings showed that genetically and antigenically divergent BPIV3 is prevalent in cattle in Japan. These results could provide a reference for molecular epidemiological characterization of BPIV3 and vaccine development.

Immunofluorescence and molecular diagnosis of bovine respiratory syncytial virus and bovine parainfluenza virus in the naturally infected young cattle and buffaloes from India

Pneumonia in bovines is a multifactorial disease manifestation leading to heavy economic losses. Infections of bovine respiratory syncytial virus (BRSV) and bovine parainfluenza virus-3 (BPI-3) are among the important contributing factors for the development of pneumonia in young animals. These viral agents either primarily cause pneumonia or predispose animals to the development of pneumonia. Although, the role of BRSV and BPI-3 in the pathogenesis of pneumonia is well established, there are no reports of involvement of BRSV and BPI-3 from Indian cattle and buffaloes suffering from pneumonia. In the present investigation, we performed postmortem examinations of 406 cattle and buffaloes, which were below twelve months of age. Out of 406 cases, twelve (2.95%) cases were positive for BRSV and fifteen (3.69%) cases were positive for BPI-3, screened by reverse transcriptase polymerase chain reaction (RT-PCR). Further, positive cases were confirmed by sequence analysis of RT-PCR amplicons and direct immunofluorescence antibody test (d-FAT) in paraffin-embedded lung tissue sections. BRSV positive cases revealed characteristic findings of bronchiolar epithelial necrosis, thickened alveolar septa by mononuclear cells infiltration and edema; alveolar lumens were filled with mononuclear cells and numerous syncytial cells were seen having intracytoplasmic inclusions. The BRSV antigen distribution was found to be in bronchiolar and alveolar epithelium and syncytial cells in the lung sections. In fifteen cases, where BPI-3 was detected, bronchointerstitial pneumonia in the majority of cases with thickened alveolar septa by mild macrophage infiltration, hyperplasia of type-II pneumocytes and bronchiolar necrosis along with syncytial cells having intracytoplasmic inclusions in the majority of cases were observed. The BPI-3 antigen distribution was found to be in bronchiolar and alveolar epithelium and syncytial cells in the lung sections. RT-PCR amplicons of BRSV and BPI-3 obtained were sequenced and their analysis showed homology with already available sequences in the NCBI database. It is the first report of detection of BRSV and BPI-3 from pneumonic cases by RT-PCR and d-FAT from cattle and buffaloes of India, indicating the need for more epidemiological studies.

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BRSV and BPI-3 induce primary pneumonia.

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Syncytia with cytoplasmic inclusion was seen.

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RT-PCR and dFAT are confirmatory diagnosis.

Characterisation of the First Bovine Parainfluenza Virus 3 Isolate Detected in Cattle in Turkey

A respiratory disease outbreak on a cattle farm in northern Turkey produced respiratory tract symptoms and severe pneumonia symptoms in 20 calves. Eight calves died, and a lung specimen from one carcass was analysed for bacteria and for viruses of the Bovine respiratory diseases complex. Bacteriological analysis was negative, but antigen detection ELISA and RT-PCR results indicated the presence of Bovine parainfluenza virus (BPIV). Virus isolation succeeded on Madin-Darby Bovine Kidney cells, and subsequent whole genome sequencing and phylogenetic analysis identified BPIV-3c. This is the first report of BPIV-3c isolation from cattle in Turkey, indicating the need for more virological and epidemiological studies.