plsMD: a plasmid reconstruction tool from short-read assemblies

Background While whole genome sequencing has become a cornerstone of antimicrobial resistance surveillance, the reconstruction of plasmid sequences from short-read data remains a challenge due to repetitive sequences and assembly fragmentation. Current computational tools for plasmid identification and binning have limitations in reconstructing full plasmid sequences, hindering downstream analyses like phylogenetic studies and antimicrobial resistance gene tracking. Results We present plsMD, a tool designed for full plasmid reconstruction from short-read assemblies. plsMD integrates Unicycler assemblies with replicon and full plasmid sequence databases to guide plasmid reconstruction through a series of contig manipulations. Using two datasets — an established benchmark dataset used in previous benchmarking studies and a novel dataset consisting of newly sequenced bacterial isolates — plsMD outperformed existing tools in both. In the benchmark dataset, it achieved excellent recall, precision, and F1 scores of 91.3%, 95.5%, and 92.0%, respectively. In the novel dataset, it achieved recall, precision, and F1 scores of 77.6, 88.9 and 74.5%, respectively. plsMD supports two usage modalities: single-sample analysis for plasmid reconstruction and gene annotation, and batch-sample analysis for phylogenetic investigations of plasmid transmission. Conclusions plsMD represents a significant advancement in plasmid analysis, offering a robust solution for utilizing existing short-read whole genome sequencing data to study plasmid-mediated antimicrobial resistance spread and evolution.