Genomic characterisation of the large segment of a rabbit picobirnavirus and comparison with the atypical picobirnavirus of Cryptosporidium parvum

Abstract

The 2362 base pair sequence of the larger of the two double stranded RNA genome segments of a rabbit strain of picobirnavirus (PBV) has a major open reading frame (ORF) of 591 amino acids and two smaller ORFs of 55 and 155 amino acids. A clone of the segment did not hybridise with other viral bisegmented ds RNAs from faecal samples. There is no relationship in sequence or organisation between this PBV sequence and the bisegmented dsRNAs found associated with Cryptosporidium parvum. This suggests that there are at least two distinct classes of bisegmented dsRNA viruses or viral-like agents in faeces.

Animal Picobirnavirus

“…Later, PBVs have been identified in faecal specimens of humans practically worldwide [3, 6, 7, 14, 26-29, 51, 55, 56, 61, 68, 76]. PBVs were also detected in faeces of a wide variety of farm mammals, birds, wild animals and birds kept in captivity, etc., viz., pigs [2,4,16,31,34,50,56,67], calves [10,15,35,53,54,61,77,79], rabbits and guinea pigs [25,43,52,65], bats [86], red fox [8], avian such as chickens & poults [1,49,59,69,73], and other wild animals kept in captivity like Giant Anteaters [45]; giant cats like Lion, Puma, Jaguar and Geoffroy's cat [37], sea lion [84], human primates such as Orangutan, wild birds such as American Ostrich, gloomy pheasant, Chinese goose [57], goat kids and lambs [60], donkeys [57,58], foals [9,30], laboratory non-human primates such as rhesus, pigtailed macaques and cynomolgus monkeys [83] and dogs [17,23,81], rats [23,64], snakes [23] and turkeys …”

“…Recently, additional sequence information of full or nearly full genome segments has become available in the for other human strains [68,76] as well as a lapine [43], a bovine PBV strain [35] and recently a California sea lion PBV (Otarine PBV) [84]. The increasing genomic information of PBVs along with the available data will be useful to know more about PBVs at the molecular level.…”

“…In 1999, it was reported that, the sequences of three ORFs of genomic segment 1 of a rabbit PBV were unrelated to the sequence of atypical Picobirnavirus (APBV), indicating that there are two distinct groups of bisegmented dsRNAs found in faecal samples [43]. In the year 2000, it was reported that few similarities were noted during comparison of RdRp-specific motifs of the genomic segment 2 of human picobirnaviruses with a unique group of closely related non-infectious dsRNA viruses of lower eukaryotes [68] (Fig.…”

Cryspovirus: a new genus of protozoan viruses in the family Partitiviridae

“…This virus was noted to be similar to previously described picobirnaviruses obtained from the feces of humans, other mammals, and birds, though with a smaller total genome length (3,000-3,500 vs. 4,000-4,500 bp). Subsequent nucleotide sequencing identified substantial differences between this ''atypical'' picobirnavirus from human feces containing Cryptosporidium oocysts and a more typical picobirnavirus from rabbits [10]. In the meantime, another laboratory group discovered a similar bisegmented dsRNA virus in propagated sporozoites from several isolates of C. parvum, but not (at that time) in those of other Cryptosporidium species [17].…”

Molecular Characterization of Porcine Picobirnaviruses and Development of a Specific Reverse Transcription-PCR Assay

“…PBV have been identified in fecal samples of humans practically worldwide (2,4,5,8,10,20,23,25,27), in feces of a wide variety of farm mammals and birds, including pigs (3,9,12,21,26), calves (7), rabbits (11,14,22), and chickens (19), and even in feces of wild animals keep in captivity (16,24,30). Despite the numerous reports of the presence of PBV in fecal samples from vertebrates, the pathogenicity of these viruses has not been established.…”