design: The genomic DNA was extracted from clinical pus. The extracted nucleic acids were subjected to library construction using the TIANamp Micro DNA Kit (DP316, TIANGEN BIOTECH) according to the manufacturers recommendation. Then, DNA libraries were constructed through DNA-fragmentation, end-repair, adapter-ligation and PCR amplification. Agilent 2100 was used for quality control of the DNA libraries. Quality qualified libraries were pooled, DNA Nanoball (DNB) was made and sequenced by MGISEQ-2000 platform.