Phage resistance formation and fitness costs of hypervirulent Klebsiella pneumoniae mediated by K2 capsule-specific phage and the corresponding mechanisms

作者：Miran Tang, Zeyu Huang, Xiaodong Zhang, Jingchun Kong, Beibei Zhou, Yijia Han, Yi Zhang, Lijiang Chen, Tieli Zhou · 发表于：Frontiers in Microbiology · 年份：2023 · DOI：10.3389/fmicb.2023.1156292 · 被引用次数：55 · 研究领域：Bacteriophages and microbial interactions、Genomics and Phylogenetic Studies

Introduction Phage is promising for the treatment of hypervirulent Klebsiella pneumoniae (hvKP) infections. Although phage resistance seems inevitable, we found that there still was optimization space in phage therapy for hvKP infection. Methods The clinical isolate K. pneumoniae FK1979 was used to recover the lysis phage ΦFK1979 from hospital sewage. Phage-resistant bacteria were obtained on LB agar and used to isolate phages from sewage. The plaque assay, transmission electron microscopy (TEM), multiplicity of infection test, one-step growth curve assay, and genome analysis were performed to characterize the phages. Colony morphology, precipitation test and scanning electron microscope were used to characterize the bacteria. The absorption test, spot test and efficiency of plating (EOP) assay were used to identify the sensitivity of bacteria to phages. Whole genome sequencing (WGS) was used to identify gene mutations of phage-resistant bacteria. The gene expression levels were detected by RT-qPCR. Genes knockout and complementation of the mutant genes were performed. The change of capsules was detected by capsule quantification and TEM. The growth kinetics, serum resistance, biofilm formation, adhesion and invasion to A549 and RAW 264.7 cells, as well as G. mellonella and mice infection models, were used to evaluate the fitness and virulence of bacteria. Results and discussion Here, we demonstrated that K2 capsule type sequence type 86 hvKP FK1979, one of the main pandemic ...