Impact of poxvirus lesions on saltwater crocodile (Crocodylus porosus) skins

Crocodilepox Virus Evolutionary Genomics Supports Observed Poxvirus Infection Dynamics on Saltwater Crocodile (Crocodylus porosus)

“…However, relatively little is known about the origins, infection dynamics, genetic diversity and inter-farm genetic variability among the circulated SwCRV in saltwater crocodiles. In agreement with other crocodilian poxviruses [6,7], saltwater crocodilepox viruses are morphologically similar to orthopoxvirus virions, demonstrating a brick-like shape with rounded corners and a dumbbell-shaped central core and lateral bodies [3,4]. Furthermore, intracellular mature virions of SwCRV display the regular crisscross surface structure pattern, which is characteristic of parapoxvirus virions [3,4,7,8].…”

“…The evolutionary origin of poxviruses is still ill-defined, however, it is believed that their genomes have evolved over thousands of years through both gene gain and loss, mainly through horizontal gene transfer and gene duplication events [1,2]. The saltwater crocodilepox virus (SwCRV) belongs to the genus Crocodylidpoxvirus, a member of the subfamily Chordopoxvirinae in the family Poxviridae and is a known causative agent of poxviral lesions on Australian saltwater crocodile skin (Crocodylus porosus) [3,4]. Although the International Committee on Taxonomy of Viruses formally recognised crocodile poxviruses under the genus Crocodylidpoxvirus [5], at this stage, no taxonomic classification has been granted for SwCRV.…”

“…Poxvirus lesions have been reported in a number of different crocodilians, including Caiman crocodilus fuscus, Caiman crocodilus yacare, C. porosus, Crocodylus johnstoni and Crocodylus niloticus [6,7,[9][10][11]. In C. porosus, poxvirus infection has been reported as a significant skin pathogen because if an individual is harvested with one or more poxvirus lesions, the lesion will result in an obvious defect on the finished leather product (4,10). Moore et al (4) described four stages of the poxvirus lesion development on C. porosus belly skins.…”

First evidence of Kunjin strain of West Nile virus associated with saltwater crocodile (Crocodylus porosus) skin lesions

“…As such, during some skin inspections on yearling (80–150 cm TL) crocodiles on one Northern Territory farm in August 2016, nine dark grey‐red 1–2 mm focal lesions were identified. Similar to early active poxvirus lesions, these lesions did not have any contour (depression or protrusion) compared to the surrounding skin. However, in contrast, they had normal overlying keratin and were distinctly darker in colour (Figure ).…”

“…These lesions were all confirmed negative for poxvirus using the PCR protocol described by Moore et al but confirmed to be WNV KUN using qRT‐PCR using the protocol described by Pyke et al Further sampling has confirmed WNV KUN in over 50 additional skin lesions. To provide further confirmation of causation, one crocodile with qRT‐PCR confirmed WNV KUN lesions was also harvested for histology and confirmed the dermal lymphohistiocytic aggregates in multiple lesions as reported by Nevarez et al (Figure ).…”