SupplementaryData_Anjos et al 2024

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging pathogen closely related to Streptococcus pyogenes, causing a range of infections from mild to severe, including necrotizing fasciitis and toxic shock syndrome. Specific pulsed-field electrophoresis (PFGE)-defined clones are often linked to human infections, but PFGE is time-consuming, costly, and results can vary between laboratories. This study explores the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) to identify biomarkers that distinguish SDSE strains with different PFGE patterns. MALDI-TOF MS spectra were generated from SDSE strains with distinct PFGE patterns (A, B, and non-A/non-B) using a Microflex LT mass spectrometer (Bruker) and standardized with BioNumerics software v7.6. FINDINGS: Specific peaks in the MALDI-TOF MS spectra successfully differentiated SDSE strains with PFGE patterns A, B, and non-A/non-B. MAIN CONCLUSIONS: Our study highlights the utility of MALDI-TOF MS not only for accurate species identification but also as a powerful tool for elucidating the diversity of SDSE strains and understanding the epidemiological relationships among different strains. The implementation of this rapid approach to identify bacterial-specific clones enhances our understanding of the role of SDSE in human infection and has the potential to shape future research and clinical practices.
Key words: Streptococcus dysgalactiae subs. equisimilis, MALDI-TOF, biomarkers, clonality.

停乳链球菌似马亚种（Streptococcus dysgalactiae subsp. equisimilis，SDSE）是一种与化脓性链球菌（Streptococcus pyogenes）密切相关的新发病原菌，可引发涵盖轻症至重症的一系列感染，包括坏死性筋膜炎与中毒性休克综合征。特定的脉冲场凝胶电泳（pulsed-field electrophoresis，PFGE）分型克隆常与人类感染相关，但PFGE检测耗时久、成本高昂，且不同实验室间的检测结果可能存在差异。本研究探讨采用基质辅助激光解吸电离飞行时间质谱（matrix-assisted laser desorption ionization-time of flight mass spectrometry，MALDI-TOF MS），以识别可区分不同PFGE分型SDSE菌株的生物标志物。研究使用Microflex LT质谱仪（布鲁克Bruker）对具有明确PFGE分型（A型、B型及非A/非B型）的SDSE菌株生成MALDI-TOF质谱图谱，并采用BioNumerics软件v7.6进行标准化处理。
研究结果显示，MALDI-TOF质谱图谱中的特定峰可成功区分PFGE分型为A型、B型及非A/非B型的SDSE菌株。
主要结论：本研究凸显了MALDI-TOF MS不仅可用于准确的菌种鉴定，还可作为阐明SDSE菌株多样性、解析不同菌株间流行病学关联的有力工具。这种快速鉴定细菌特异性克隆的方法，有助于加深我们对SDSE在人类感染中作用的认识，并有望为未来的研究及临床实践提供指导。
关键词：停乳链球菌似马亚种（Streptococcus dysgalactiae subsp. equisimilis），MALDI-TOF，生物标志物，克隆性。