Fig. 4

Clonal relatedness of ESBL-producing E. cloacae complex isolates. a Profile of β-lactam resistance genes. Dashed lines separate the outbreak isolates of 2017 (first and second outbreak episode), the outbreak isolates of 2018 (third outbreak episode, supplemented with two isolates from non-cardiac surgery patients PC1 and PC2) and the negative control isolates (collected in 2017 from non-cardiac surgery patients not involved in the outbreak, denoted as NC1, NC2 and NC3). Blue, presence of a gene sequence in the isolate genome with > 90% identity to a β-lactam resistance gene in the ResFinder database; green, presence of a gene sequence in the isolate genome with 100% identity to a β-lactam resistance gene in the ResFinder database; yellow, resistance gene not detected in the isolate genome. b Sequence type as assessed by MLST. For each isolate genome, the best-matching allele at each locus of the MLST scheme was identified and sequence type was then determined by the combined allelic profile. Numbers shown are unique identifiers of alleles and sequence types. Dashed lines separate the outbreak isolates of 2017, the outbreak isolates of 2018 and the negative control isolates. Abbreviations: ESBL extended-spectrum β-lactamase, MLST multilocus sequence typing, ST sequence type