Objective To establish a high-throughput screening system to obtain key Staphylococcus aureus (S.aureus)secretory proteins which required for S.aureus survival in macrophages.Methods Based on our validated eukaryotic expression vector library of S.aureus secretory proteins,DNA transfection was used to obtain an RAW264.7 macrophage array expressing S.aureus secretory proteins.After the RAW264.7 cells were infected with S.aureus,the extracellular bacteria were removed to observe the intracellular surviving situation of S.aureus.Finally,the screening results were validated by the overexpression and knockout S.aureus of corresponding secretory proteins.Results The optimal transfection dose (1.0 μg/well)of plasmids for RAW264.7,multiplicity of infection (MOI,1 .0 ),and infection time (4 h after removing extracellular bacteria of S.aureus ) were established respectively.To validate the screening results,the corresponding overexpression and knockout strains were constructed.And hypothetical protein and Serine protease E were found to promote the survival of intracellular S.aureus.Conclusion We successfully construct a screening system for key secreted secretory proteins which required for S.aureus surviving in macrophages,which may advance the study of the intracellular surviving mechanism of S.aureus.

Sarcomatoid carcinoma of the renal pelvis accounts for a very low percentage of malignant tumors in the renal pelvis and has a poor prognosis. This article reported a patient with sarcomatoid carcinoma of the renal pelvis. The patient presented with macroscopic hematuria as the first symptom, and CT suggested left renal occupancy, unilateral nephrectomy was performed, and pathology suggested sarcomatoid carcinoma of the renal pelvis. Three weeks after surgery, a follow-up CT showed tumor recurrence. Programmed death 1(PD-1)inhibitor was given once every 3 weeks. Repeated CT examination after 24 weeks of continuous treatment suggested that the recurrent tumor disappeared. The patients was followed-up for 42 months without tumor recurrence or metastasis.