Characterization of an outbreak of astroviral diarrhea in a group of cheetahs (Acinonyx jubatus)

Abstract

A Mamastrovirus was identified in an outbreak of diarrhea in cheetahs (Acinonyx jubatus). Five young adult and two adult cheetahs presented with lethargy, anorexia, watery diarrhea and regurgitation over an 11-day period. Fecal samples were submitted for electron microscopy and culture. Electron microscopy results revealed particles morphologically consistent with an astrovirus, and no other viral pathogens or significant bacterial pathogens were identified. The astrovirus was confirmed and sequenced using consensus astroviral PCR, resulting in a 367 base pair partial RNA-dependent-RNA polymerase (RdRp) product and a 628 base pair partial capsid product. Bayesian and maximum likelihood phylogenetic analyses were performed on both the RdRp and the capsid protein segments. All animals were monitored and treated with bismuth subsalicylate tablets (524mg PO BID for 5 days), and recovered without additional intervention. This is the first report we are aware of documenting an astrovirus outbreak in cheetah.

Characterization of phylogenetically diverse astroviruses of marine mammals

“…This may represent a separate recombination event with an as-yet-unidentified clade of astroviruses. An analysis of the capsid region of a cheetah astrovirus found that it clustered relatively more closely with human astroviruses than was found in the analysis of the polymerase (Atkins et al, 2009). If due to a recombination event, this is an apparently opposite event from that seen in CslAstV-3, which has a human astrovirus-like polymerase and a CslAstV-2-like capsid, at least in the 59 end of ORF2.…”

“…Only very recently has the presence of astroviruses in wildlife hosts been reported (Atkins et al, 2009;Chu et al, 2008). Here, we report the first detection of five genetically distinct astroviruses from three marine mammal host species.…”

“…Degenerate primers designed based on conserved astroviral sequences (Atkins et al, 2009) were used in a nested or a semi-nested format to amplify conserved regions of ORF1b (RdRp) and ORF2 (capsid). For amplification of the partial RdRp gene, primers Astr4380F (59-GAYTGGRCNCGNTWYGATGGNACIAT-39) and Astr4811R (59-GGYTTNACCCACATNCCAAA-39) (round 1) and primers Astr4574F (59-GGNAAYCCMTCWGGICA-39) and Astr4722R (59-ARNCKRTCATCNCCATA-39) (round 2) were used on all five isolates.…”

Human Astroviruses

“…In most cases, viruses have been mostly isolated from healthy animals, and prevalences are high. The genetic diversity of feline AstVs (FAstVs), canine AstVs (CaAstVs), rabbit AstVs (RabAstVs), rat AstVs, and AstVs infecting sea lions and dolphins has not been studied so extensively, and the clinical impact of their infections seems to be low and has not been well explored yet (11,16,17,(196)(197)(198)(199)(200).…”

“…However, later on, two genera were established based on their hosts of origin: Mamastrovirus (MAstV) and Avastrovirus (AAstV), infecting mammalian and avian species, respectively. Although initially detected in children's stool, AstVs have been found in the feces of a wide variety of mammalian species, i.e., cats (6), cattle (7), deer (8), dogs (9), mice (10), rats (11), pigs (12), sheep (13), mink (14), bats (15), cheetahs (16), rabbits (17), and even sea lions and dolphins (18), as well as in avian species, i.e., turkeys (19), chickens (20), ducks (21), pigeons (22), and guinea fowl (23) and other wild aquatic birds (24).…”