Supplementary Material 5

The use of Multilocus Sequence Typing (MLST) in the identification of <i>Escherichia coli</i> is crucial for understanding its genetic diversity, evolutionary relationships, and epidemiological significance. MLST provides a standardized and highly reproducible method for strain classification by analyzing variations in housekeeping genes, enabling precise identification of distinct sequence types (STs). This approach is particularly important in differentiating pathogenic <i>E. coli</i> strains, such as extraintestinal pathogenic <i>E. coli</i> (ExPEC) and Shiga toxin-producing <i>E. coli</i> (STEC), from commensal isolates. Additionally, MLST helps track the spread of antimicrobial-resistant clones, monitor outbreak sources, and study global strain distribution through publicly available databases like PubMLST. By offering a high-resolution and scalable approach to bacterial typing, MLST plays a vital role in clinical diagnostics, infection control, and evolutionary studies of <i>E. coli</i>.多位点序列分型（Multilocus Sequence Typing, MLST）在大肠埃希氏菌（Escherichia coli，常俗称大肠杆菌）鉴定中的应用，对于解析该菌的遗传多样性、进化关联以及流行病学意义至关重要。MLST通过分析持家基因的序列变异，可为菌株分型提供标准化且重复性优异的方法，能够精准识别不同的序列型（Sequence Types, STs）。该方法在区分致病性大肠埃希氏菌菌株（如肠外致病性大肠埃希氏菌（extraintestinal pathogenic E. coli, ExPEC）与产志贺毒素大肠埃希氏菌（Shiga toxin-producing E. coli, STEC））与共生分离株方面尤为关键。此外，MLST可用于追踪耐药克隆的传播、监测暴发源头，并通过PubMLST等公开数据库开展全球菌株分布研究。作为一种高分辨率、可扩展的细菌分型手段，MLST在大肠埃希氏菌的临床诊断、感染防控以及进化研究中发挥着核心作用。