Sequence type and strain-level detection of Klebsiella pneumoniae in culture-enriched bacterial metagenomes: comparative performance of mSWEEP and StrainGE bioinformatic tools

Klebsiella pneumoniae is a major cause of human infections and is frequently associated with antimicrobial resistance (AMR). Carriage of K. pneumoniae in the gut is a major risk factor for infection and a reservoir for the spread of high-risk clonal lineages and associated AMR determinants. Accurate detection of K. pneumoniae at the subspecies level is therefore essential to better understand K. pneumoniae gut colonization ecology and clonal dissemination. We analysed two recently developed bioinformatic tools, mSWEEP and StrainGE, for sequence type (ST) detection of K. pneumoniae in culture-enriched sweep metagenomes compared to single-colony whole-genome sequencing (WGS). We show that both mSWEEP and StrainGE perform highly accurate ST detection, concordant with culture in 46/49 and 44/49 samples with WGS-detected single STs, respectively, as well as in 2/3 samples with two WGS-detected STs. Within-sample ST diversity was detected in 19 and 15 samples by mSWEEP and StrainGE, respectively, highlighting a major advantage of these tools over conventional single-colony WGS. StrainGE could also reconstruct accurate phylogenetic relationships between strains of the same ST for 2/3 different STs tested. Additionally, assembly of the genomes provides better resolution of ST detection by mSWEEP. Together, our results show that both mSWEEP and StrainGE are accurate tools for the detection and analysis of K. pneumoniae STs from mixed bacterial samples.