Presence of polyketide synthase (PKS) gene and counterpart virulence determinants in Klebsiella pneumoniae strains enhances colorectal cancer progression in-vitro.

This study aims to investigate the effect of colibactin producing Klebsiella pneumoniae (PKS-positive K. pneumoniae) in enhancing colorectal cancer (CRC) cell proliferation in-vitro. The findings in this study revealed a greater enhancement of cell proliferation among CRC cell lines that are exposed to PKS-positive K. pneumoniae antigens compared to PKS-negative K. pneumoniae. In addition, certain virulence factors such as presence of genes confering siderophore production had a synergistic effect in enhancing CRC cell line proliferation. To further validate the findings, ECIS assay was performed to show that the greater enhancement of cell proliferation observed among CRC cell lines were consistent with the presence of PKS-positive K. pneumoniae exposure.

本研究旨在探讨产大肠杆菌素（colibactin）的肺炎克雷伯菌（Klebsiella pneumoniae，即PKS阳性肺炎克雷伯菌，PKS-positive K. pneumoniae）在体外增强结直肠癌（colorectal cancer, CRC）细胞增殖的作用。本研究结果显示，与PKS阴性肺炎克雷伯菌相比，暴露于PKS阳性肺炎克雷伯菌抗原的结直肠癌细胞系的增殖增强效果更为显著。此外，部分毒力因子——例如携带有编码铁载体合成基因的菌株——在增强结直肠癌细胞系增殖方面具有协同效应。为进一步验证本研究结论，研究人员开展了细胞阻抗传感（Electric Cell-substrate Impedance Sensing, ECIS）实验，结果证实结直肠癌细胞系中观测到的增殖增强效应，与PKS阳性肺炎克雷伯菌的暴露状态相一致。