Fig. 2

Gene phylogenetic tree was created by the ML method using 295 or 298 nt (GI) and 282 nt (GII) from the 5′-end of VP1. a Gene phylogenetic tree of GI. Nucleotide substitution model was GTR + Gamma. b Gene phylogenetic tree of GII.2. Nucleotide substitution model was K80 + Gamma. c Gene phylogenetic tree of GII.4. Nucleotide substitution model was K80 + Gamma. d Gene phylogenetic tree of GII.6. Nucleotide substitution model was K80 + Gamma. e Gene phylogenetic tree of GII.17. Nucleotide substitution model was GTR + Invariant. The strains detected in this study were shown as a black circle. Strains detected in multiple cases are shown in bold. The site of the outbreaks and their number are described at the end of the strain name. Cases at childcare and educational facilities (C) are colored blue, cases involving food poisoning (F) are colored red, those at elderly nursing homes (E) are colored orange, and others (O) are colored green