Genetic Diversity and Biological Characteristics of a Novel Feline Calicivirus Strain Isolated From Zoo-Captive South China Tiger (Panthera tigris amoyensis)
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引用次数: 0
Abstract
Feline calicivirus (FCV) is a common pathogen causing upper respiratory tract disease in domestic cats. Nonetheless, its threat and genetic features in endangered wild felids remain poorly understood. In this study, a novel FCV strain from a captive South China tiger (Panthera tigris amoyensis) was isolated, designated as FCV LYH1224. Viral RNA was detected in multiple tissues of the deceased tiger, including the heart, liver, spleen, lungs, and kidneys, suggesting broad tissue tropism and FCV contributed substantially to the fatal outcome. In vitro growth kinetics showed that the virus replicates efficiently in Crandell-Rees feline kidney (CRFK) cells. Whole-genome sequencing and phylogenetic analysis indicated that it was classified as genotype II (GII) and exhibited unique evolutionary lineages. Within GII, it clusters closely with the previously reported tiger-derived strain FCV-YH/16 but exhibits an independent branch in the VP1 gene tree, suggesting complex genetic variation among FCV strains from diverse wildlife origins. Sequence identity analysis indicated that FCV LYH1224 was genetically distant from vaccine strains F9 and 2280, with whole-genome nucleotide identity of 76.6% and 77.0%, respectively. Notably, the VP1-E region displayed the lowest identity, with nucleotide identity of 68.1% and 66.7%, respectively. Analysis of key amino acid residues revealed distinct substitutions within the neutralizing epitope (aa 445–451) and common mutations at virulence-related positions 452A and 492I, which were absent in reference strains, suggesting potential antigenic diversity and host-specific adaptations. This study provides a comprehensive genomic characterization of FCV strain in South China tigers, highlighting the genetic diversity and distinctive antigenic properties observed in this isolate compared with existing strains. The considerable genetic divergence from vaccine strains emphasizes the importance of ongoing surveillance and the inclusion of wildlife-derived strains in vaccine development strategies.
期刊介绍:
Transboundary and Emerging Diseases brings together in one place the latest research on infectious diseases considered to hold the greatest economic threat to animals and humans worldwide. The journal provides a venue for global research on their diagnosis, prevention and management, and for papers on public health, pathogenesis, epidemiology, statistical modeling, diagnostics, biosecurity issues, genomics, vaccine development and rapid communication of new outbreaks. Papers should include timely research approaches using state-of-the-art technologies. The editors encourage papers adopting a science-based approach on socio-economic and environmental factors influencing the management of the bio-security threat posed by these diseases, including risk analysis and disease spread modeling. Preference will be given to communications focusing on novel science-based approaches to controlling transboundary and emerging diseases. The following topics are generally considered out-of-scope, but decisions are made on a case-by-case basis (for example, studies on cryptic wildlife populations, and those on potential species extinctions):
Pathogen discovery: a common pathogen newly recognised in a specific country, or a new pathogen or genetic sequence for which there is little context about — or insights regarding — its emergence or spread.
Prevalence estimation surveys and risk factor studies based on survey (rather than longitudinal) methodology, except when such studies are unique. Surveys of knowledge, attitudes and practices are within scope.
Diagnostic test development if not accompanied by robust sensitivity and specificity estimation from field studies.
Studies focused only on laboratory methods in which relevance to disease emergence and spread is not obvious or can not be inferred (“pure research” type studies).
Narrative literature reviews which do not generate new knowledge. Systematic and scoping reviews, and meta-analyses are within scope.