ORIGINAL ARTICLE The possible molecular evolution of sapoviruses by inter- and intra-genogroup recombination Karoline dos Anjos • Lidia M. P. Lima • Paula Andreia Silva • Alice K. Inoue-Nagata • Tatsuya Nagata Received: 19 May 2011 / Accepted: 15 July 2011 / Published online: 28 July 2011 Ó Springer-Verlag 2011 Abstract Sapporo virus belongs to the genus Sapovirus (family Caliciviridae) and has a non-segmented single- stranded, positive-sense RNA genome. This virus causes acute gastroenteritis in human, porcine and mink hosts. In this study, the complete genome of a Brazilian sapovirus isolate from a child with acute gastroenteritis was deter- mined. A phylogenetic tree was constructed to analyze the genotype of this sapovirus (Sapo_BR-DF01), and possible intra- and inter-genogroups recombination events were evaluated in silico using the RDP3 program. Two inter- genogroup and two intra-genogroup recombination events were newly recognized in this study. Keywords Calicivirus Á RdRp-CP junction site Á Inter-genogroup recombination Introduction The family Caliciviridae consists of viruses belonging to five genera: Sapovirus, Norovirus, Lagovirus, Vesivirus and Nebovirus (www.ictvdb.org/ICTVdB/index.htm). Certain sapovirus and norovirus strains are well-known causative agents of serious human gastroenteritis all around the world, including South America [9, 17, 27, 36]. The diseases caused by sapoviruses and noroviruses differ from each other both in their epidemiological features and clinical symptoms. For example, in infants under two years old, norovirus causes a moderate to severe disease, with vom- iting as its predominant symptom, whereas sapovirus, in general, causes mild diarrhea [30]. Sapporo virus, which, to date, is the only member of the genus Sapovirus, was originally found in an outbreak of diarrhea occurring in an orphanage in Sapporo, Japan, in 1977 [4]. Its transmission is through the fecal-oral route and is often associated with ingestion of contami- nated food and water. Many reports on epidemiological studies of sapovirus in Asia, Europe and the Americas are available, and today, it is recognized as an important agent of acute gastroenteritis [12, 29, 33]. The basic characterization of sapoviruses has been seriously ham- pered by the fact that human sapovirus strains are still non-cultivable [7, 13, 25], while one isolate (Po/SV/ Cowden/1980/US), the porcine-infecting strain, is the only sapovirus that can be propagated in cultured cells [2, 7, 25]. Sapovirus causes gastroenteritis in humans, pigs and mink [10, 11, 14, 15], and it is currently divided into seven genogroups (GI-GVII). The viruses of genogroups I, II, IV and V are human-infecting sapovirus, whereas those of GIII and GVI infect pigs, and those of GVII infect mink [5, 28]. Their classification into genogroups and, more Electronic supplementary material The online version of this article (doi:10.1007/s00705-011-1079-8) contains supplementary material, which is available to authorized users. K. dos Anjos Á T. Nagata (&) Departamento de Biologia Celular, Universidade de Brası ´lia, 70910-900 Brası ´lia, DF, Brazil e-mail: tatsuya@unb.br L. M. P. Lima LACEN-DF, Laborato ´rio Central de Sau ´de Pu ´blica do DF, 70830-010 Brası ´lia, DF, Brazil P. A. Silva Po ´s-graduac ¸a ˜o em Cie ˆncias Geno ˆmicas e Biotecnologia, Universidade Cato ´lica de Brası ´lia, 70790-160 Brası ´lia, DF, Brazil A. K. Inoue-Nagata EmbrapaVegetables, Caixa Postal 218, 70359-970 Brası ´lia, DF, Brazil 123 Arch Virol (2011) 156:1953–1959 DOI 10.1007/s00705-011-1079-8