Fodah Ramy A, Scott Jacob B, Tam Hok-Hei, Yan Pearlly, Pfeffer Tia L, Bundschuh Ralf, Warawa Jonathan M
Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, United States of America.
Dental School, University of Louisville, Louisville, Kentucky, United States of America; College of Dentistry, Ohio State University, Columbus, Ohio, United States of America.
PLoS One. 2014 Sep 9;9(9):e107394. doi: 10.1371/journal.pone.0107394. eCollection 2014.
Klebsiella pneumoniae is a bacterial pathogen of worldwide importance and a significant contributor to multiple disease presentations associated with both nosocomial and community acquired disease. ATCC 43816 is a well-studied K. pneumoniae strain which is capable of causing an acute respiratory disease in surrogate animal models. In this study, we performed sequencing of the ATCC 43816 genome to support future efforts characterizing genetic elements required for disease. Furthermore, we performed comparative genetic analyses to the previously sequenced genomes from NTUH-K2044 and MGH 78578 to gain an understanding of the conservation of known virulence determinants amongst the three strains. We found that ATCC 43816 and NTUH-K2044 both possess the known virulence determinant for yersiniabactin, as well as a Type 4 secretion system (T4SS), CRISPR system, and an acetonin catabolism locus, all absent from MGH 78578. While both NTUH-K2044 and MGH 78578 are clinical isolates, little is known about the disease potential of these strains in cell culture and animal models. Thus, we also performed functional analyses in the murine macrophage cell lines RAW264.7 and J774A.1 and found that MGH 78578 (K52 serotype) was internalized at higher levels than ATCC 43816 (K2) and NTUH-K2044 (K1), consistent with previous characterization of the antiphagocytic properties of K1 and K2 serotype capsules. We also examined the three K. pneumoniae strains in a novel BALB/c respiratory disease model and found that ATCC 43816 and NTUH-K2044 are highly virulent (LD50<100 CFU) while MGH 78578 is relatively avirulent.
肺炎克雷伯菌是一种在全球范围内具有重要意义的细菌病原体，是与医院获得性疾病和社区获得性疾病相关的多种疾病表现的重要促成因素。ATCC 43816是一种经过充分研究的肺炎克雷伯菌菌株，能够在替代动物模型中引起急性呼吸道疾病。在本研究中，我们对ATCC 43816基因组进行了测序，以支持未来对疾病所需遗传元件进行表征的工作。此外，我们对先前测序的NTUH-K2044和MGH 78578基因组进行了比较遗传分析，以了解这三种菌株中已知毒力决定因素的保守情况。我们发现，ATCC 43816和NTUH-K2044都具有已知的yersiniabactin毒力决定因素，以及IV型分泌系统（T4SS）、CRISPR系统和丙酮分解代谢位点，而MGH 78578中均不存在这些。虽然NTUH-K2044和MGH 78578都是临床分离株，但关于这些菌株在细胞培养和动物模型中的致病潜力知之甚少。因此，我们还在小鼠巨噬细胞系RAW264.7和J774A.1中进行了功能分析，发现MGH 78578（K52血清型）的内化水平高于ATCC 43816（K2）和NTUH-K2044（K1），这与先前对K1和K2血清型荚膜抗吞噬特性的表征一致。我们还在一种新型BALB/c呼吸道疾病模型中检测了这三种肺炎克雷伯菌菌株，发现ATCC 43816和NTUH-K2044具有高毒力（LD50<100 CFU），而MGH 78578相对无毒力。
