Fig. 3.

Hierarchical clustering tree showing the genetic relationship of all invasive N. meningitidis strains identified by the Portuguese National Reference Laboratory during the period 2012 to 2020. The genetic diversity among isolates was evaluated by a gene-by-gene analysis using the newly improved cgMLST schema v2, with 1422 N. meningitidis core-loci (Jolley et al. 2018). Phylogenetic tree was constructed using the hierarchical single-linkage method, based on the number of shared cgMLST alleles among 327 validated isolates (two isolates were discarded since displayed < 90% loci-called) and was drawn using microreact (https://microreact.org/). Isolates are depicted by small black circles that are differentially colored, the external ring according to their year of isolation and the internal ring according to their serogroup. The internal shading displayed in several colors shows the partitions of the various clonal complexes