MERS-CoV‒Specific T-Cell Responses in Camels after Single MVA-MERS-S Vaccination.

We developed an ELISPOT assay for evaluating Middle East respiratory syndrome coronavirus (MERS-CoV)‒specific T-cell responses in dromedary camels. After single modified vaccinia virus Ankara-MERS-S vaccination, seropositive camels showed increased levels of MERS-CoV‒specific T cells and antibodies, indicating suitability of camel vaccinations in disease-endemic areas as a promising approach to control infection.

Comparative investigations into the growth details of Histoplasma capsulatum var farciminosum on four different agar media.

Epizootic equine lymphangitis (EEL) is a chronic fungal disease that affects equids. The causative agent is a dimorphic fungus called Histoplasma capsulatum var farciminosum. Histoplasmacapsulatum var farciminosum field strain 7 (D 2878/2023) isolated from the eye socket of an EEL Ethiopian horse was sub-cultured on four different solid media and incubated at 26°C and 37°C for 6 weeks. Details of growth morphology were recorded and shown in images during 6 weeks of incubation. Histoplasmacapsulatum var farciminosum grew best at 26°C on all four agars, but only on sheep blood agar at 37°C as small, white dry colonies.

Histoplasma capsulatum var farciminosum was isolated from the eye socket of an equine epizootic lymphangitis infected Ethiopian horse on Mycosel agar, which was sub-cultured on four different solid media at two different temperatures for 6 weeks to show its growth pattern.

Detection of viral antibodies in camel sera using magnetic particle spectroscopy.

Pandemics like SARS-Cov-2 very frequently have their origin in different animals and in particular herds of camels could be a source of zoonotic diseases. This study took advantage on a highly sensitive and adaptable method for the fast and reliable detection of viral antibodies in camels using low-cost equipment. Magnetic nanoparticles (MNP) have high variability in their functionalization with different peptides and proteins. We confirm that 3-aminopropyl triethoxysilane (APTES)-coated MNP could be functionalized with viral proteins. The protein loading could be confirmed by simple loading controls using FACS-analysis (p < 0.05). Complementary combination of antigen and antibody yields in a significant signal increase could be proven by both FACS and COMPASS. However, COMPASS needs only a few seconds for the measurement. In COMPASS, the phase φn on selected critical point of the fifth higher harmonic (n = 5th). Here, positive sera display highly significant signal increase over the control or negative sera. Furthermore, a clear distinction could be made in antibody detection as an immune response to closely related viruses (SARS-CoV2 and MERS). Using modified MNPs along with COMPASS offers a fast and reliable method that is less cost intensive than current technologies and offers the possibility to be quickly adapted in case of new occurring viral infections. KEY POINTS: • COMPASS (critical offset magnetic particle spectroscopy) allows the fast detection of antibodies. • Magnetic nanoparticles can be adapted by exchange of the linked bait molecule. • Antibodies could be detected in camel sera without washing steps within seconds.

Patterns of microchromosome organization remain highly conserved throughout avian evolution.

The structure and organization of a species genome at a karyotypic level, and in interphase nuclei, have broad functional significance. Although regular sized chromosomes are studied extensively in this regard, microchromosomes, which are present in many terrestrial vertebrates, remain poorly explored. Birds have more cytologically indistinguishable microchromosomes (~ 30 pairs) than other vertebrates; however, the degree to which genome organization patterns at a karyotypic and interphase level differ between species is unknown. In species where microchromosomes have fused to other chromosomes, they retain genomic features such as gene density and GC content; however, the extent to which they retain a central nuclear position has not been investigated. In studying 22 avian species from 10 orders, we established that, other than in species where microchromosomal fusion is obvious (Falconiformes and Psittaciformes), there was no evidence of microchromosomal rearrangement, suggesting an evolutionarily stable avian genome (karyotypic) organization. Moreover, in species where microchromosomal fusion has occurred, they retain a central nuclear location, suggesting that the nuclear position of microchromosomes is a function of their genomic features rather than their physical size.

Upgrading short-read animal genome assemblies to chromosome level using comparative genomics and a universal probe set.

Most recent initiatives to sequence and assemble new species' genomes de novo fail to achieve the ultimate endpoint to produce contigs, each representing one whole chromosome. Even the best-assembled genomes (using contemporary technologies) consist of subchromosomal-sized scaffolds. To circumvent this problem, we developed a novel approach that combines computational algorithms to merge scaffolds into chromosomal fragments, PCR-based scaffold verification, and physical mapping to chromosomes. Multigenome-alignment-guided probe selection led to the development of a set of universal avian BAC clones that permit rapid anchoring of multiple scaffolds to chromosomes on all avian genomes. As proof of principle, we assembled genomes of the pigeon (Columbia livia) and peregrine falcon (Falco peregrinus) to chromosome levels comparable, in continuity, to avian reference genomes. Both species are of interest for breeding, cultural, food, and/or environmental reasons. Pigeon has a typical avian karyotype (2n = 80), while falcon (2n = 50) is highly rearranged compared to the avian ancestor. By using chromosome breakpoint data, we established that avian interchromosomal breakpoints appear in the regions of low density of conserved noncoding elements (CNEs) and that the chromosomal fission sites are further limited to long CNE "deserts." This corresponds with fission being the rarest type of rearrangement in avian genome evolution. High-throughput multiple hybridization and rapid capture strategies using the current BAC set provide the basis for assembling numerous avian (and possibly other reptilian) species, while the overall strategy for scaffold assembly and mapping provides the basis for an approach that (provided metaphases can be generated) could be applied to any animal genome.

Immune response of horses to inactivated African horse sickness vaccines.

BACKGROUND: African horse sickness (AHS) is a serious viral disease of equids resulting in the deaths of many equids in sub-Saharan Africa that has been recognized for centuries. This has significant economic impact on the horse industry, despite the good husbandry practices. Currently, prevention and control of the disease is based on administration of live attenuated vaccines and control of the arthropod vectors. RESULTS: A total of 29 horses in 2 groups, were vaccinated. Eighteen horses in Group 1 were further divided into 9 subgroups of 2 horses each, were individually immunised with one of 1 to 9 AHS serotypes, respectively. The eleven horses of Group 2 were immunised with all 9 serotypes simultaneously with 2 different vaccinations containing 5 serotypes (1, 4, 7-9) and 4 serotypes (2, 3, 5, 6) respectively. The duration of this study was 12 months. Blood samples were periodically withdrawn for serum antibody tests using ELISA and VNT and for 2 weeks after each vaccination for PCR and virus isolation. After the booster vaccination, these 27 horses seroconverted, however 2 horses responded poorly as measured by ELISA. In Group 1 ELISA and VN antibodies declined between 5 to 7 months post vaccination (pv). Twelve months later, the antibody levels in most of the horses decreased to the seronegative range until the annual booster where all horses again seroconverted strongly. In Group 2, ELISA antibodies were positive after the first booster and VN antibodies started to appear for some serotypes after primary vaccination. After booster vaccination, VN antibodies increased in a different pattern for each serotype. Antibodies remained high for 12 months and increased strongly after the annual booster in 78% of the horses. PCR and virus isolation results remained negative. CONCLUSIONS: Horses vaccinated with single serotypes need a booster after 6 months and simultaneously immunised horses after 12 months. Due to the non-availability of a facility in the UAE, no challenge infection could be carried out.

Two novel dromedary camel bocaparvoviruses from dromedaries in the Middle East with unique genomic features.

The recent emergence of Middle East respiratory syndrome (MERS) coronavirus and its discovery from dromedary camels has boosted interest in the search for novel viruses in dromedaries. While bocaparvoviruses are known to infect various animals, it was not known that they exist in dromedaries. In this study, we describe the discovery of two novel dromedary camel bocaparvoviruses (DBoVs), DBoV1 and DBoV2, from dromedary faecal samples in Dubai. Among 667 adult dromedaries and 72 dromedary calves, 13.9 % of adult dromedaries and 33.3 % of dromedary calves were positive for DBoV1, while 7.0 % of adult dromedaries and 25.0 % of dromedary calves were positive for DBoV2, as determined by PCR. Sequencing of 21 DBoV1 and 18 DBoV2 genomes and phylogenetic analysis showed that DBoV1 and DBoV2 formed two distinct clusters, with only 32.6-36.3 % amino acid identities between the DBoV1 and DBoV2 strains. Quasispecies were detected in both DBoVs. The amino acid sequences of the NS1 proteins of all the DBoV1 and DBoV2 strains showed <85 % identity to those of all the other bocaparvoviruses, indicating that DBoV1 and DBoV2 are two bocaparvovirus species according to the ICTV criteria. Although the typical genome structure of NS1-NP1-VP1/VP2 was observed in DBoV1 and DBoV2, no phospholipase A2 motif and associated calcium binding site were observed in the predicted VP1 sequences for any of the 18 sequenced DBoV2, and no start codons were found for their VP1. For all 18 DBoV2 genomes, an AT-rich region of variable length and composition was present downstream to NP1. Further studies will be crucial to understand the pathogenic potential of DBoVs in this unique group of animals.

Equine rhinitis B viruses in horse fecal samples from the Middle East.

BACKGROUND: Among all known picornaviruses, only two species, equine rhinitis A virus and equine rhinitis B virus (ERBV) are known to infect horses, causing respiratory infections. No reports have described the detection of ERBV in fecal samples of horses and no complete genome sequences of ERBV3 are available. METHODS: We performed a molecular epidemiology study to detect ERBVs in horses from Dubai and Hong Kong. Complete genome sequencing of the ERBVs as well as viral loads and genome, phylogenetic and evolutionary analysis were performed on the positive samples. RESULTS: ERBV was detected in four (13.8 %) of the 29 fecal samples in horses from Dubai, with viral loads 8.28 × 10(3) to 5.83 × 10(4) copies per ml, but none of the 47 fecal samples in horses from Hong Kong by RT-PCR. Complete genome sequencing and phylogenetic analysis showed that three of the four strains were ERBV3 and one was ERBV2. The major difference between the genomes of ERBV3 and those of ERBV1 and ERBV2 lied in the amino acid sequences of their VP1 proteins. The Ka/Ks ratios of all the coding regions in the ERBV3 genomes were all <0.1, suggesting that ERBV3 were stably evolving in horses. Using the uncorrelated lognormal distributed relaxed clock model on VP1 gene, the date of the most recent common ancestor (MRCA) of ERBV3 was estimated to be 1785 (HPDs, 1176 to 1937) and the MRCA dates of ERBV1 and ERBV2 were estimated to be 1848 (HPDs, 1466 to 1949) respectively. CONCLUSIONS: Both acid stable (ERBV3) and acid labile (ERBV2) ERBVs could be found in fecal samples of horses. Detection of ERBVs in fecal samples would have implications for their transmission and potential role in gastrointestinal diseases as well as fecal sampling as an alternative method of identifying infected horses.

Isolation and Characterization of Dromedary Camel Coronavirus UAE-HKU23 from Dromedaries of the Middle East: Minimal Serological Cross-Reactivity between MERS Coronavirus and Dromedary Camel Coronavirus UAE-HKU23.

Recently, we reported the discovery of a dromedary camel coronavirus UAE-HKU23 (DcCoV UAE-HKU23) from dromedaries in the Middle East. In this study, DcCoV UAE-HKU23 was successfully isolated in two of the 14 dromedary fecal samples using HRT-18G cells, with cytopathic effects observed five days after inoculation. Northern blot analysis revealed at least seven distinct RNA species, corresponding to predicted subgenomic mRNAs and confirming the core sequence of transcription regulatory sequence motifs as 5'-UCUAAAC-3' as we predicted previously. Antibodies against DcCoV UAE-HKU23 were detected in 58 (98.3%) and 59 (100%) of the 59 dromedary sera by immunofluorescence and neutralization antibody tests, respectively. There was significant correlation between the antibody titers determined by immunofluorescence and neutralization assays (Pearson coefficient = 0.525, p < 0.0001). Immunization of mice using recombinant N proteins of DcCoV UAE-HKU23 and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively, and heat-inactivated DcCoV UAE-HKU23 showed minimal cross-antigenicity between DcCoV UAE-HKU23 and MERS-CoV by Western blot and neutralization antibody assays. Codon usage and genetic distance analysis of RdRp, S and N genes showed that the 14 strains of DcCoV UAE-HKU23 formed a distinct cluster, separated from those of other closely related members of Betacoronavirus 1, including alpaca CoV, confirming that DcCoV UAE-HKU23 is a novel member of Betacoronavirus 1.

Acute middle East respiratory syndrome coronavirus infection in livestock Dromedaries, Dubai, 2014.

Camels carry Middle East respiratory syndrome coronavirus, but little is known about infection age or prevalence. We studied >800 dromedaries of all ages and 15 mother-calf pairs. This syndrome constitutes an acute, epidemic, and time-limited infection in camels <4 years of age, particularly calves. Delayed social separation of calves might reduce human infection risk.

Outbreaks of highly pathogenic avian influenza H5N1 clade 2.3.2.1c in hunting falcons and kept wild birds in Dubai implicate intercontinental virus spread.

Highly pathogenic avian influenza viruses (HPAIVs) of subtype H5N1 have continued to perpetuate with divergent genetic variants in poultry within Asia since 2003. Further dissemination of Asian-derived H5 HPAIVs to Europe, Africa and, most recently, to the North American continent has occurred. We report an outbreak of HPAIV H5N1 among falcons kept for hunting and other wild bird species bred as falcon prey in Dubai, United Arab Emirates, during the autumn of 2014. The causative agent was identified as avian influenza virus subtype H5N1, clade 2.3.2.1c, by genetic and phylogenetic analyses. High mortality in infected birds was in accordance with systemic pathomorphological and histological alterations in affected falcons. Genetic analysis showed the HPAIV H5N1 of clade 2.3.2.1c is a reassortant in which the PB2 segment was derived from an Asian-origin H9N2 virus lineage. The Dubai H5N1 viruses were closely related to contemporary H5N1 HPAIVs from Nigeria, Burkina-Faso, Romania and Bulgaria. Median-joining network analysis of 2.3.2.1c viruses revealed that the Dubai outbreak was an episode of a westward spread of these viruses on a larger scale from unidentified Asian sources. The incursion into Dubai, possibly via infected captive hunting falcons returning from hunting trips to central Asian countries, preceded outbreaks in Nigeria and other West African countries. The alarmingly enhanced geographical mobility of clade 2.3.2.1.c and clade 2.3.4.4 viruses may represent another wave of transcontinental dissemination of Asian-origin HPAIV H5 viruses, such as the outbreak at Qinghai Lake caused by clade 2.2 ('Qinghai' lineage) in 2005.

A novel astrovirus from dromedaries in the Middle East.

The recent emergence of Middle East respiratory syndrome coronavirus from the Middle East and its discovery from dromedary camels has boosted interest in the search for novel viruses in dromedaries. The existence of astroviruses (AstVs) in dromedaries was previously unknown. We describe the discovery of a novel dromedary camel AstV (DcAstV) from dromedaries in Dubai. Among 215 dromedaries, DcAstV was detected in faecal samples of four [three (1.5 %) adult dromedaries and one (8.3 %) dromedary calf] by reverse transcription-PCR. Sequencing of the four DcAstV genomes and phylogenetic analysis showed that the DcAstVs formed a distinct cluster. Although DcAstV was most closely related to a recently characterized porcine AstV 2, their capsid proteins only shared 60-66 % amino acid identity, with a mean amino acid genetic distance of 0.372. Notably, the N-terminal halves of the capsid proteins of DcAstV shared ≤ 85 % amino acid identity, but the C-terminal halves only shared ≤ 49 % amino acid identity compared with the corresponding proteins in other AstVs. A high variation of the genome sequences of DcAstV was also observed, with a mean amino acid genetic distance of 0.214 for ORF2 of the four strains. Recombination analysis revealed a possible recombination event in ORF2 of strain DcAstV-274. The low Ka/Ks ratios (number of non-synonymous substitutions per non-synonymous site to number of synonymous substitutions per synonymous site) of the four ORFs in the DcAstV genomes supported the suggestion that dromedaries are the natural reservoir where AstV is stably evolving. These results suggest that AstV is a novel species of the genus Mamastrovirus in the family Astroviridae. Further studies are important to understand the pathogenic potential of DcAstV.

Antibody prevalence to avian influenza virus subtypes H5, H7 and H9 in falcons, captive and wild birds, United Arab Emirates, 2003-2006.

BACKGROUND: Avian influenza viruses (AIV) may cause enormous economic losses in the poultry industry and sporadically severe disease in humans. Falconry is a tradition of great importance in the Arabian Peninsula. Falcons may catch AIV through contact with infected quarry species. OBJECTIVES: Falcons together with other bird species are the focus of this seroprevalence study, carried out on sera collected in the United Arab Emirates (UAE). AIV with the haemagglutinin subtypes H5, H7 and possibly H9 may infect humans. METHODS: We investigated the antibody prevalence to these subtypes in falcons and other birds by haemagglutination inhibition test. 617 sera of falcons and 429 sera of 46 wild/captive bird species were tested. RESULTS: From the falcons, only one was positive for H5 antibodies (0.2%), none contained antibodies to H7, but 78 had antibodies to H9 (13.2%). Regarding other birds, eight were positive for antibodies to H5 (2.1%), none had antibodies to H7, but 55 sera from 17 species contained antibodies to H9 (14.4%). CONCLUSIONS: In contrast to H5 and H7 infections, H9N2 is widespread worldwide. Its ability to reassort, thereby creating possibly pathogenic strains for humans, should remind us of the potential risk that close contact with birds entails.

Comparative Genome Analysis of All Nine African Horse Sickness Serotypes Isolated From Equine Fatalities in Kenya and South Africa.

African horse sickness (AHS) is a viral disease of equids, caused by a virus of the genus Orbivirus, family Reoviridae. The African horse sickness virus (AHSV) genome is made up of ten double-stranded RNA (dsRNA) segments that together code for seven structural and four nonstructural proteins. AHS is endemic in sub-Saharan countries. The efficacy and safety of inactivated AHS vaccines containing all nine serotypes, produced at the Central Veterinary Research Laboratory (CVRL) in Dubai, United Arab Emirates have been proven in the past. All nine AHSV serotypes were isolated from 102 samples collected in the last 20 years from horse fatalities in seven different area of Kenya, Africa. CVRL inactivated AHS vaccines are used in a few African countries defining the importance of this present study to compare the genome sequences of the nine AHSV serotypes isolated from horse fatalities in Kenya and nine AHSV serotypes isolated in South Africa. The hypothesized serotypes of the newly sequenced AHSV field strains from Kenya were likewise confirmed in this investigation, and they show substantial sequence homologies with recently isolated AHSV field strains.

The Experimental Infection of Goats with Small Ruminant Morbillivirus Originated from Barbary Sheep.

Peste des Petits Ruminants (PPR) is a transboundary contagious disease in domestic small ruminants. Infections with the small ruminant morbillivirus (SRMV) were regularly found in wildlife, with unknown roles in PPR epidemiology. In order to access infection dynamics and virulence, we infected German Edelziege goats intranasally with a SRMV isolate that originated from Barbary sheep from an outbreak in the United Arab Emirates. Six goats were infected with cell culture-isolated SRMV, and two goats were kept in contact. Goats were daily monitored, and clinical score was recorded. EDTA blood, nasal, conjunctival and rectal swab samples were collected for the detection of SRMV genome load and serum for serological analysis. Short incubation period in infected (4 to 5 dpi) as well as in contact goats (9 dpi) was followed by typical clinical signs related to PPR. The highest viral load was detectable in conjunctival and nasal swab samples with RT-qPCR and rapid pen-side test. Specific antibodies were detected at 7 dpi in infected and 14 dpi in contact goats. In general, high virulence and easy transmission of the virus originated from wildlife in domestic goats was observed. The virus isolate belongs to Asian lineage IV, genetically related to Chinese and Mongolian strains.

Outbreak of a Systemic Form of Camelpox in a Dromedary Herd (Camelus dromedarius) in the United Arab Emirates.

Camelpox virus (CMLV) is the causative agent of camelpox, which frequently occurs in the Old World camelids-rearing countries except for Australia. It has also been described in experimentally inoculated New World camelids. Camelpox outbreaks are often experienced shortly after the rainy season, which occurs twice a year on the Arabian Peninsula because of the increased density of the insect population, particularly mosquitos. A systemic form of camelpox outbreak in seven dromedary camels was diagnosed by histology, virus isolation, and PCR. A phylogenetic analysis using full length CMLV genomes of the isolated CMLV strains showed a single phylogenetic unit without any distinctive differences between them. The United Arab Emirates (UAE) isolate sequences showed phylogenetical relatedness with CMLV isolates from Israel with only minor sequence differences. Although the sequences of viruses from both countries were closely related, the disease manifestation was vastly different. Our study shows that the virulence is not only determined by genetic features of CMLV alone but may also depend on other factors such as unknown aspects of the host (e.g., age, overall fitness), management, and the environment.

High Prevalence of Genogroup I and Genogroup II Picobirnaviruses in Dromedary Camels.

Picobirnaviruses (PBVs) are small non-enveloped bisegmented double-stranded RNA viruses found in humans, mammals, and birds. Increasing molecular epidemiology studies suggest a high sequence diversity of PBVs in numerous hosts and the environment. In this study, using 229 fecal samples from dromedary camels in Dubai, 52.8% were positive for PBVs, of which 77.7% and 41.3% were positive for genogroup I and II, respectively, and 19.0% were positive for both genotypes. Phylogenetic analysis showed high diversity among the sequences of genogroup I and II dromedary PBVs. Marked nucleotide polymorphisms were observed in 75.5% and 46.0% of genogroup I and II RNA-dependent RNA polymerase (RdRp) sequences, respectively, suggesting the co-existence of multiple strains in the same specimen. Both high genetic diversity and prevalence of genogroup I and II PBV in dromedaries were observed. In fact, the prevalence of genogroup II PBV in dromedaries is the highest among all animals to date. The complete/near-complete core genomes of five genogroup I and one genogroup II dromedary PBVs and partial segment 1 and 2 of both genotypes were also sequenced. The dromedary PBV genome organizations were similar to those of other animals. Genetic reassortment and mutation are both important in the ecology and evolution of PBVs.

Humoral antibody response of 10 horses after vaccination against African horse sickness with an inactivated vaccine containing all 9 serotypes in one injection.

BACKGROUND: African horse sickness (AHS) is a devastating viral disease of equids that was first recorded in 1327. Currently, prevention and control of the disease are based on attenuated vaccines and midge control. It has been shown that attenuated Orbivirus vaccines are not always safe as they may reverse to virulence. OBJECTIVES: In the Emirate of Dubai, a vaccination experiment was carried out with an inactivated AHS vaccine produced at the Central Veterinary Research Laboratory (CVRL), Dubai, UAE to investigate the humoral antibody response of AHS-naïve horses to this vaccine. Our vaccination experiment was performed to establish an AHS vaccine bank in the UAE to protect horses from the disease in case of an outbreak. Therefore, CVRL established an inactivated AHS vaccine containing all nine serotypes which induce high neutralising antibodies. STUDY DESIGN: A total of 10 horses kept in a desert isolation area were subcutaneously and intramuscularly vaccinated with an inactivated vaccine containing all nine AHS serotypes previously isolated from Kenyan horse fatalities. Primary immunisation was followed by two booster immunisations 4 weeks and 6 months apart. After 13 months, an annual booster was administered. METHODS: Blood samples were regularly withdrawn for ELISA and virus neutralisation testing. Additionally, EDTA blood was tested every second day for 14 days post each vaccination for the presence of AHS virus or its RNA. RESULTS: Results show that ELISA and virus neutralising antibodies appeared after the first booster, declined after 4-6 months and therefore three vaccinations and an annual vaccination are necessary to achieve high protective virus neutralising antibodies. MAIN LIMITATIONS: No challenge infection was carried out due to the lack of a safe facility in the UAE. CONCLUSION: Before more advanced AHS vaccines become a reality, inactivated vaccines containing all nine serotypes should be used as they produce high ELISA and neutralising antibodies.

Co-circulation of a Novel Dromedary Camel Parainfluenza Virus 3 and Middle East Respiratory Syndrome Coronavirus in a Dromedary Herd With Respiratory Tract Infections.

Since the emergence of Middle East Respiratory Syndrome (MERS) in 2012, there have been a surge in the discovery and evolutionary studies of viruses in dromedaries. Here, we investigated a herd of nine dromedary calves from Umm Al Quwain, the United Arab Emirates that developed respiratory signs. Viral culture of the nasal swabs from the nine calves on Vero cells showed two different types of cytopathic effects (CPEs), suggesting the presence of two different viruses. Three samples showed typical CPEs of Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) in Vero cells, which was confirmed by partial RdRp gene sequencing. Complete genome sequencing of the three MERS-CoV strains showed that they belonged to clade B3, most closely related to another dromedary MERS-CoV isolate previously detected in Dubai. They also showed evidence of recombination between lineages B4 and B5 in ORF1ab. Another three samples showed non-typical CPEs of MERS-CoV with cell rounding, progressive degeneration, and detachment. Electron microscopy revealed spherical viral particles with peplomers and diameter of about 170nm. High-throughput sequencing and metagenomic analysis showed that the genome organization (3'-N-P-M-F-HN-L-5') was typical of paramyxovirus. They possessed typical genome features similar to other viruses of the genus Respirovirus, including a conserved motif 323FAPGNYALSYAM336 in the N protein, RNA editing sites 5'-717AAAAAAGGG725-3', and 5'-1038AGAAGAAAGAAAGG1051-3' (mRNA sense) in the P gene with multiple polypeptides coding capacity, a nuclear localization signal sequence 245KVGRMYSVEYCKQKIEK261 in the M protein, a conserved sialic acid binding motif 252NRKSCS257 in the HN protein, conserved lengths of the leader (55nt) and trailer (51nt) sequences, total coding percentages (92.6-93.4%), gene-start (AGGANNAAAG), gene-end (NANNANNAAAAA), and trinucleotide intergenic sequences (CTT, mRNA sense). Phylogenetic analysis of their complete genomes showed that they were most closely related to bovine parainfluenza virus 3 (PIV3) genotype C strains. In the phylogenetic tree constructed using the complete L protein, the branch length between dromedary camel PIV3 (DcPIV3) and the nearest node is 0.04, which is >0.03, the definition used for species demarcation in the family Paramyxoviridae. Therefore, we show that DcPIV3 is a novel species of the genus Respirovirus that co-circulated with MERS-CoV in a dromedary herd in the Middle East.