Fig. 2

Phylogenetic tree based on (a) partial polymerase and (b) capsid regions of norovirus GII. Norovirus strains isolated from patients during the outbreak are shown in this phylogenetic analysis and are marked with a black filled circle. Branches containing strains classified within the cluster of the emergent genotype GII.4 Sydney [P16] are highlighted in red on both trees. Reference strains were downloaded from GenBank and labeled with the genotype followed by their accession number. Sequence alignments were performed using the MUSCLE algorithm. Neighbor-joining phylogenetic trees were constructed using MEGAX software with bootstrap tests (2000 replicates) based on the Kimura two-parameter model. Bootstrap percentage values are shown at each branch point for values ≥60%