Figure 2. Core-genome phylogenetic tree of 748 Serratia marcescens genomes from the National Center for Biotechnology Information RefSeq database (https://www.ncbi.nlm.nih.gov/refseq) and 18 KPC 3–producing strains from an outbreak of KPC 3–producing Enterobacterales infection at a tertiary hospital in Ningbo, Zhejiang Province, China, August 1, 2020–June 30, 2021. The isolation country is color-coded and illustrated at the tips. Carbapenemases are presented as a color-coded outer circle. The tree was rooted in the midpoint. Scale bar represents 0.01 mutations per nucleotide position. KPC, K. pneumoniae carbapenemase; NA, not available; UK, United Kingdom; USA, United States.