摘要
      溶血性葡萄球菌是一种与医院获得性感染相关的机会性病原体。然而，溶血性链球菌在患者和医院环境中的遗传多样性在很大程度上是未知的。在这里，我们从患者和医院环境的不同采样点分离出311株溶血性链球菌。基因组分析表明，ST42是一种在医院广泛传播的新兴克隆。与其他溶血性链球菌相比，溶血性链球菌ST42菌株对多种抗生素的易感性降低，并携带更多的抗生素抗性基因（ARGs）。此外，ST42菌株每个分离物比其他ST菌株携带更多的毒力基因，并且荚膜生物合成基因capDEFG在ST42菌株中更普遍。使用意大利黑加仑菌感染模型，我们证明ST42菌株与非ST42菌株相比具有高毒力。总之，我们的数据确定了一个新出现的溶血性链球菌ST42克隆，该克隆在医院中具有聚集的ARGs和毒力决定因素，这在疾病和治疗方面都对健康构成了重大威胁。
ABSTRACT
Staphylococcus haemolyticus is an opportunistic pathogen associated with hospital-acquired infections. However, the genetic diversity of S. haemolyticus among the patients and the hospital environment is largely unknown. Here, we isolated 311 S. haemolyticus strains from different sampling sites of patients and hospital environment. Genomic analysis showed that ST42 is an emerging clone widely disseminated in the hospital. S. haemolyticus ST42 strains exhibited decreased susceptibilities for multiple antibiotics compared with other STs and carried significantly more antibiotic resistance genes (ARGs). Furthermore, ST42 strains harbored more virulence genes per isolate than in other STs, and the capsular biosynthesis genes capDEFG were more prevalent in ST42 strains. Using the Galleria mellonella infection model, we demonstrated that ST42 strains are highly virulent compared with non-ST42 strains. Taken together, our data identified an emerging ST42 clone of S. haemolyticus with aggregated ARGs and virulence determinants in the hospital, representing a significant health threat in terms of both disease and treatment.

https://journals.asm.org/doi/full/10.1128/spectrum.02342-21