Novel divergent nidovirus in a python with pneumonia

Abstract

The order Nidovirales contains large, enveloped viruses with a non-segmented positive-stranded RNA genome. Nidoviruses have been detected in man and various animal species, but, to date, there have been no reports of nidovirus in reptiles. In the present study, we describe the detection, characterization, phylogenetic analyses and disease association of a novel divergent nidovirus in the lung of an Indian python (Python molurus) with necrotizing pneumonia. Characterization of the partial genome (>33 000 nt) of this virus revealed several genetic features that are distinct from other nidoviruses, including a very large polyprotein 1a, a putative ribosomal frameshift signal that was identical to the frameshift signal of astroviruses and retroviruses and an accessory ORF that showed some similarity with the haemagglutinin–neuraminidase of paramyxoviruses. Analysis of genome organization and phylogenetic analysis of polyprotein 1ab suggests that this virus belongs to the subfamily Torovirinae. Results of this study provide novel insights into the genetic diversity within the order Nidovirales.

Nidovirus-Associated Proliferative Pneumonia in the Green Tree Python (Morelia viridis)

“…New nidoviruses were recently identified in the lungs of cattle and wild shingleback lizards with pneumonia, though their direct association with disease has so far not been examined (31,37). We found MVNV-associated lesions almost exclusively in the airways and lungs, similar to previous reports on nidovirus infections in other python species (8,9,15). The detection of viral RNA by PCR in other tissues, such as the liver, spleen, kidney, and intestine, however, indicated that the viruses spread systemically.…”

“…We also detected viral antigen in epithelial cells of the cranial esophagus in one affected animal; however, in M. viridis the esophagus carries a ciliated epithelium (data not shown), a feature also known for other snake species (57,58); infection could therefore be due to an overspill from the trachea and nasal cavity. We did not detect viral antigen in any cells of the stomach or intestine, and a previous study also did not find viral RNA by RNA-ISH, suggesting that the python nidoviruses are primarily respiratory (8). Viral spread via the expelling of mucus from the nasal cavity would be a likely route of transmission.…”

“…We interpreted these bacterial sequences to most likely represent either contamination during postmortem sample collection or, more likely, a secondary bacterial infection, as both had also shown moderate diffuse heterophil infiltration in the lungs. From the third snake (animal A2), however, we obtained a single ϳ21,000-nucleotide (nt) contig and several shorter contigs that matched the previously identified sequences of ball python nidovirus (BPNV) and python nidovirus (PNV) (the 21,000-nt contig was ϳ85% identical to the sequences of both viruses) (8,9). In total, we obtained ϳ28,000 nt (ϳ75 to 80%) of the genome from the lung tissue sample.…”

Pathological findings in the red fox (Vulpes vulpes), stone marten (Martes foina) and raccoon dog (Nyctereutes procyonoides), with special emphasis on infectious and zoonotic agents in Northern Germany

“…This approach has led to a number of newly detected viruses in various animal species in recent years [37–40] and might be of great interest for detecting potentially zoonotic and infectious diseases in wildlife species.…”

Discovery of a novel nidovirus in cattle with respiratory disease

“…The genus Bafinivirus includes two viruses isolated from fish (White bream virus and White minnow nidovirus) (Batts et al, 2012;Schütze et al, 2006). Within the past year, nidoviruses have been described in pythons with pneumonia [python nidovirus (PNV) and ball python nidovirus (BPNV)] and these viruses are proposed to represent a novel genus within the subfamily Torovirinae (Bodewes et al, 2014;Stenglein et al, 2014;Uccellini et al, 2014). Here, we report on the discovery and genomic characterization of a novel virus that represents a distinctive lineage within this subfamily.…”