Abstract
Simple SummaryAlthough often considered host-specific, there is increasing evidence of a broader-than-expected host tropism for different circoviruses, including porcine circovirus 2 (PCV-2). In this study, the presence of PCV-2 in the lung lymph nodes of Namibian jackals has been demonstrated. The complete genome of the viruses was generated, and they were classified as PCV-2b and shown to have a close genetic relationship with South African and Namibian strains collected from domestic pigs. Since contact between jackals and domestic swine is highly unlikely, one of the most plausible explanations for the infection of the jackals with PCV-2b would involve the dispersal of pig-derived products in the wild environment during recreational activities or the scavenging activity of jackals living in peri-urban areas. However, further studies are required to properly assess how PCV-2 is acquired and maintained in the wild canids and its potential impact on other wild and domestic species.Members of the genus Circovirus have been identified in several host species. While initially considered host-specific, there is growing evidence of their presence in unexpected hosts. Porcine circovirus 2 (PCV-2) is no exception, having been reported in animals belonging to different orders, including carnivores. Recently, PCV-2 was detected in domestic pigs, warthogs and antelopes in Namibia. Considering the potential contact between these populations and wild carnivores, the presence of PCV-2 was investigated in 32 black-backed jackals (Lupulella mesomelas) shot between February and July 2021 as part of predator control operations in Namibia. Two lung lymph nodes tested positive for PCV-2 by PCR, confirming the broader-than-expected PCV-2 host tropism and the susceptibility of canids. Sequence analysis demonstrated a close association between the PCV-2s identified in the jackals and PCV-2b strains collected from South African domestic pigs. Although several hypotheses regarding the source of the jackal’s infection are proposed, further studies should be performed to properly assess how PCV-2 is acquired and maintained in the wild and its potential impact on wild and domestic species.
Highlights
The genus Circovirus includes non-enveloped single-stranded ambisense DNA viruses with a genome of approximately 2kb, encoding two main proteins from two open reading frames (ORFs)
Sequence analysis demonstrated a close association between the Porcine circovirus 2 (PCV-2) identified in the jackals and PCV-2b strains collected from South African domestic pigs
Porcine circovirus type 2 (PCV-2), which causes several syndromes globally defined as porcine circovirus diseases (PCVD) and is responsible for major losses for the swine industry, was initially strongly associated with domestic pigs and wild boar [11–14]
Summary
The genus Circovirus includes non-enveloped single-stranded ambisense DNA viruses with a genome of approximately 2kb, encoding two main proteins from two open reading frames (ORFs). ORF1 encodes the replication-associated protein Rep and Rep’ through alternative splicing, while ORF2 encodes the Cap protein, the only constituent of the viral capsid [1]. The Cap has been extensively studied, is responsible for viral attachment, contributing to host and cell tropism, and is the main target of the host immune response [2–4]. Other ORFs and related proteins (ORF3-6) have been characterized and were proven to mainly be involved in apoptosis regulation and interaction with the host immune system [7–10]. Mice have been successfully used as experimental models [15,16] and, over time, other hosts have been reported to be infected with the virus, the clinical and epidemiological relevance is much debated. Some Chinese studies have reported PCV-2 infection in carnivores (i.e., mink, foxes, and raccoon dogs) in the presence of severe clinical signs [23–25]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
