Full Viral Genome Sequencing and Phylogenomic Analysis of Feline Herpesvirus Type 1 (FHV-1) in Cheetahs (Acinonyx jubatus).

Scott B Citino,Morgan E Marino,David J Maggs,Edward J Dubovi,Andrew C Lewin,Lyndon M Coghill,Jessica A Emerson,Nikole E Ineck,Renee T Carter,Melanie A Mironovich,Rachel C Turner

doi:10.3390/v13112307

Abstract

Feline herpesvirus type 1 (FHV-1) is endemic in captive cheetahs and sporadically causes devastating disease. Modified live vaccines (MLV), intended for use in domestic cats, are used in some captive cheetah populations and have been anecdotally linked to disease in certain subpopulations. Ten FHV-1 isolates from ten captive cheetahs and one isolate from an MLV used to inoculate four of the host animals were analyzed. Viral DNA was extracted for full-genome sequencing by Illumina MiSeq with viral genomes then used for phylogenomic and recombinational analyses. The FHV-1 shed by vaccinated cheetahs were almost identical to the MLV, with few variants among viral genomes. Eight cheetah FHV-1 isolates and the MLV were grouped in a clade along with FHV-1 isolates from domestic cats in the USA. The remaining two cheetah FHV-1 isolates (unknown host vaccine status) were not associated with a clade. The likely ancestral origin of these two isolates involves recombination events between Australian domestic cat and cheetah FHV-1 isolates. Collectively, these data suggest that the MLV is capable of causing clinical disease and viral shedding in some cheetahs and represents evidence of interspecies transmission of virus between domestic and wild cats.

Highlights

Wild cheetah (Acinonyx jubatus) populations are considered “vulnerable” according to the International Union of Conservation Nature (IUCN) but are quickly approaching “endangered” status as populations continue to decline [1]
Cheetahs are believed to be vulnerable to viral diseases due to genetic monomorphisms at the major histocompatibility complex (MHC), which allow Feline herpesvirus type 1 (FHV-1) to evade the host immune system [8]
Sequenced and analyzed viral isolates were included in the phylogenomic analysis, including 52 domestic cat FHV-1 isolates, 2 FHV-1 modified live vaccines (MLV) isolates, and 1 canine herpesvirus (CHV-1) outgroup [15,16]

Summary

Introduction

Wild cheetah (Acinonyx jubatus) populations are considered “vulnerable” according to the International Union of Conservation Nature (IUCN) but are quickly approaching “endangered” status as populations continue to decline [1]. Feline herpesvirus type 1 (FHV-1) is a contributing factor to mortalities and is endemic in captive cheetah populations [3]. While the domestic cat is the dominant host, FHV-1 has been isolated from numerous wild felid species, including captive, semi-captive, and free-ranging cheetahs [2,3,4,5]. While most cheetahs experience mild disease, others develop severe ocular, respiratory, and dermatologic clinical signs [6,7]. This can result in a life-long infection and clinical signs of disease due to viral latency and persistent viral shedding [3,7]. Severe disease can lead to humane euthanasia in some animals, which limits captive population growth [9]

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